Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

139 files changed, 24986 insertions, 0 deletions

diff --git a/samples/bpf/.gitignore b/samples/bpf/.gitignore
new file mode 100644
index 000000000..b2f29bc8d
--- /dev/null
+++ b/samples/bpf/.gitignore
@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: GPL-2.0-only
+cpustat
+fds_example
+hbm
+ibumad
+lathist
+lwt_len_hist
+map_perf_test
+offwaketime
+per_socket_stats_example
+sampleip
+sock_example
+sockex1
+sockex2
+sockex3
+spintest
+syscall_nrs.h
+syscall_tp
+task_fd_query
+tc_l2_redirect
+test_cgrp2_array_pin
+test_cgrp2_attach
+test_cgrp2_attach2
+test_cgrp2_sock
+test_cgrp2_sock2
+test_current_task_under_cgroup
+test_lru_dist
+test_map_in_map
+test_overhead
+test_probe_write_user
+trace_event
+trace_output
+tracex1
+tracex2
+tracex3
+tracex4
+tracex5
+tracex6
+tracex7
+xdp1
+xdp2
+xdp_adjust_tail
+xdp_fwd
+xdp_monitor
+xdp_redirect
+xdp_redirect_cpu
+xdp_redirect_map
+xdp_router_ipv4
+xdp_rxq_info
+xdp_sample_pkts
+xdp_tx_iptunnel
+xdpsock
+xsk_fwd
+testfile.img
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
new file mode 100644
index 000000000..aeebf5d12
--- /dev/null
+++ b/samples/bpf/Makefile
@@ -0,0 +1,329 @@
+# SPDX-License-Identifier: GPL-2.0
+
+BPF_SAMPLES_PATH ?= $(abspath $(srctree)/$(src))
+TOOLS_PATH := $(BPF_SAMPLES_PATH)/../../tools
+
+# List of programs to build
+tprogs-y := test_lru_dist
+tprogs-y += sock_example
+tprogs-y += fds_example
+tprogs-y += sockex1
+tprogs-y += sockex2
+tprogs-y += sockex3
+tprogs-y += tracex1
+tprogs-y += tracex2
+tprogs-y += tracex3
+tprogs-y += tracex4
+tprogs-y += tracex5
+tprogs-y += tracex6
+tprogs-y += tracex7
+tprogs-y += test_probe_write_user
+tprogs-y += trace_output
+tprogs-y += lathist
+tprogs-y += offwaketime
+tprogs-y += spintest
+tprogs-y += map_perf_test
+tprogs-y += test_overhead
+tprogs-y += test_cgrp2_array_pin
+tprogs-y += test_cgrp2_attach
+tprogs-y += test_cgrp2_sock
+tprogs-y += test_cgrp2_sock2
+tprogs-y += xdp1
+tprogs-y += xdp2
+tprogs-y += xdp_router_ipv4
+tprogs-y += test_current_task_under_cgroup
+tprogs-y += trace_event
+tprogs-y += sampleip
+tprogs-y += tc_l2_redirect
+tprogs-y += lwt_len_hist
+tprogs-y += xdp_tx_iptunnel
+tprogs-y += test_map_in_map
+tprogs-y += per_socket_stats_example
+tprogs-y += xdp_redirect
+tprogs-y += xdp_redirect_map
+tprogs-y += xdp_redirect_cpu
+tprogs-y += xdp_monitor
+tprogs-y += xdp_rxq_info
+tprogs-y += syscall_tp
+tprogs-y += cpustat
+tprogs-y += xdp_adjust_tail
+tprogs-y += xdpsock
+tprogs-y += xsk_fwd
+tprogs-y += xdp_fwd
+tprogs-y += task_fd_query
+tprogs-y += xdp_sample_pkts
+tprogs-y += ibumad
+tprogs-y += hbm
+
+# Libbpf dependencies
+LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a
+
+CGROUP_HELPERS := ../../tools/testing/selftests/bpf/cgroup_helpers.o
+TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o
+
+fds_example-objs := fds_example.o
+sockex1-objs := sockex1_user.o
+sockex2-objs := sockex2_user.o
+sockex3-objs := sockex3_user.o
+tracex1-objs := tracex1_user.o $(TRACE_HELPERS)
+tracex2-objs := tracex2_user.o
+tracex3-objs := tracex3_user.o
+tracex4-objs := tracex4_user.o
+tracex5-objs := tracex5_user.o $(TRACE_HELPERS)
+tracex6-objs := tracex6_user.o
+tracex7-objs := tracex7_user.o
+test_probe_write_user-objs := test_probe_write_user_user.o
+trace_output-objs := trace_output_user.o $(TRACE_HELPERS)
+lathist-objs := lathist_user.o
+offwaketime-objs := offwaketime_user.o $(TRACE_HELPERS)
+spintest-objs := spintest_user.o $(TRACE_HELPERS)
+map_perf_test-objs := map_perf_test_user.o
+test_overhead-objs := bpf_load.o test_overhead_user.o
+test_cgrp2_array_pin-objs := test_cgrp2_array_pin.o
+test_cgrp2_attach-objs := test_cgrp2_attach.o
+test_cgrp2_sock-objs := test_cgrp2_sock.o
+test_cgrp2_sock2-objs := bpf_load.o test_cgrp2_sock2.o
+xdp1-objs := xdp1_user.o
+# reuse xdp1 source intentionally
+xdp2-objs := xdp1_user.o
+xdp_router_ipv4-objs := xdp_router_ipv4_user.o
+test_current_task_under_cgroup-objs := $(CGROUP_HELPERS) \
+				       test_current_task_under_cgroup_user.o
+trace_event-objs := trace_event_user.o $(TRACE_HELPERS)
+sampleip-objs := sampleip_user.o $(TRACE_HELPERS)
+tc_l2_redirect-objs := bpf_load.o tc_l2_redirect_user.o
+lwt_len_hist-objs := bpf_load.o lwt_len_hist_user.o
+xdp_tx_iptunnel-objs := xdp_tx_iptunnel_user.o
+test_map_in_map-objs := test_map_in_map_user.o
+per_socket_stats_example-objs := cookie_uid_helper_example.o
+xdp_redirect-objs := xdp_redirect_user.o
+xdp_redirect_map-objs := xdp_redirect_map_user.o
+xdp_redirect_cpu-objs := xdp_redirect_cpu_user.o
+xdp_monitor-objs := xdp_monitor_user.o
+xdp_rxq_info-objs := xdp_rxq_info_user.o
+syscall_tp-objs := syscall_tp_user.o
+cpustat-objs := cpustat_user.o
+xdp_adjust_tail-objs := xdp_adjust_tail_user.o
+xdpsock-objs := xdpsock_user.o
+xsk_fwd-objs := xsk_fwd.o
+xdp_fwd-objs := xdp_fwd_user.o
+task_fd_query-objs := bpf_load.o task_fd_query_user.o $(TRACE_HELPERS)
+xdp_sample_pkts-objs := xdp_sample_pkts_user.o $(TRACE_HELPERS)
+ibumad-objs := bpf_load.o ibumad_user.o $(TRACE_HELPERS)
+hbm-objs := bpf_load.o hbm.o $(CGROUP_HELPERS)
+
+# Tell kbuild to always build the programs
+always-y := $(tprogs-y)
+always-y += sockex1_kern.o
+always-y += sockex2_kern.o
+always-y += sockex3_kern.o
+always-y += tracex1_kern.o
+always-y += tracex2_kern.o
+always-y += tracex3_kern.o
+always-y += tracex4_kern.o
+always-y += tracex5_kern.o
+always-y += tracex6_kern.o
+always-y += tracex7_kern.o
+always-y += sock_flags_kern.o
+always-y += test_probe_write_user_kern.o
+always-y += trace_output_kern.o
+always-y += tcbpf1_kern.o
+always-y += tc_l2_redirect_kern.o
+always-y += lathist_kern.o
+always-y += offwaketime_kern.o
+always-y += spintest_kern.o
+always-y += map_perf_test_kern.o
+always-y += test_overhead_tp_kern.o
+always-y += test_overhead_raw_tp_kern.o
+always-y += test_overhead_kprobe_kern.o
+always-y += parse_varlen.o parse_simple.o parse_ldabs.o
+always-y += test_cgrp2_tc_kern.o
+always-y += xdp1_kern.o
+always-y += xdp2_kern.o
+always-y += xdp_router_ipv4_kern.o
+always-y += test_current_task_under_cgroup_kern.o
+always-y += trace_event_kern.o
+always-y += sampleip_kern.o
+always-y += lwt_len_hist_kern.o
+always-y += xdp_tx_iptunnel_kern.o
+always-y += test_map_in_map_kern.o
+always-y += tcp_synrto_kern.o
+always-y += tcp_rwnd_kern.o
+always-y += tcp_bufs_kern.o
+always-y += tcp_cong_kern.o
+always-y += tcp_iw_kern.o
+always-y += tcp_clamp_kern.o
+always-y += tcp_basertt_kern.o
+always-y += tcp_tos_reflect_kern.o
+always-y += tcp_dumpstats_kern.o
+always-y += xdp_redirect_kern.o
+always-y += xdp_redirect_map_kern.o
+always-y += xdp_redirect_cpu_kern.o
+always-y += xdp_monitor_kern.o
+always-y += xdp_rxq_info_kern.o
+always-y += xdp2skb_meta_kern.o
+always-y += syscall_tp_kern.o
+always-y += cpustat_kern.o
+always-y += xdp_adjust_tail_kern.o
+always-y += xdp_fwd_kern.o
+always-y += task_fd_query_kern.o
+always-y += xdp_sample_pkts_kern.o
+always-y += ibumad_kern.o
+always-y += hbm_out_kern.o
+always-y += hbm_edt_kern.o
+always-y += xdpsock_kern.o
+
+ifeq ($(ARCH), arm)
+# Strip all except -D__LINUX_ARM_ARCH__ option needed to handle linux
+# headers when arm instruction set identification is requested.
+ARM_ARCH_SELECTOR := $(filter -D__LINUX_ARM_ARCH__%, $(KBUILD_CFLAGS))
+BPF_EXTRA_CFLAGS := $(ARM_ARCH_SELECTOR)
+TPROGS_CFLAGS += $(ARM_ARCH_SELECTOR)
+endif
+
+TPROGS_CFLAGS += -Wall -O2
+TPROGS_CFLAGS += -Wmissing-prototypes
+TPROGS_CFLAGS += -Wstrict-prototypes
+
+TPROGS_CFLAGS += -I$(objtree)/usr/include
+TPROGS_CFLAGS += -I$(srctree)/tools/testing/selftests/bpf/
+TPROGS_CFLAGS += -I$(srctree)/tools/lib/
+TPROGS_CFLAGS += -I$(srctree)/tools/include
+TPROGS_CFLAGS += -I$(srctree)/tools/perf
+TPROGS_CFLAGS += -DHAVE_ATTR_TEST=0
+
+ifdef SYSROOT
+TPROGS_CFLAGS += --sysroot=$(SYSROOT)
+TPROGS_LDFLAGS := -L$(SYSROOT)/usr/lib
+endif
+
+TPROGCFLAGS_bpf_load.o += -Wno-unused-variable
+
+TPROGS_LDLIBS			+= $(LIBBPF) -lelf -lz
+TPROGLDLIBS_tracex4		+= -lrt
+TPROGLDLIBS_trace_output	+= -lrt
+TPROGLDLIBS_map_perf_test	+= -lrt
+TPROGLDLIBS_test_overhead	+= -lrt
+TPROGLDLIBS_xdpsock		+= -pthread
+TPROGLDLIBS_xsk_fwd		+= -pthread
+
+# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
+#  make M=samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
+LLC ?= llc
+CLANG ?= clang
+OPT ?= opt
+LLVM_DIS ?= llvm-dis
+LLVM_OBJCOPY ?= llvm-objcopy
+BTF_PAHOLE ?= pahole
+
+# Detect that we're cross compiling and use the cross compiler
+ifdef CROSS_COMPILE
+CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
+endif
+
+# Don't evaluate probes and warnings if we need to run make recursively
+ifneq ($(src),)
+HDR_PROBE := $(shell printf "\#include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
+	$(CC) $(TPROGS_CFLAGS) $(TPROGS_LDFLAGS) -x c - \
+	-o /dev/null 2>/dev/null && echo okay)
+
+ifeq ($(HDR_PROBE),)
+$(warning WARNING: Detected possible issues with include path.)
+$(warning WARNING: Please install kernel headers locally (make headers_install).)
+endif
+
+BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris)
+BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF)
+BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm')
+BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \
+			  $(CLANG) -target bpf -O2 -g -c -x c - -o ./llvm_btf_verify.o; \
+			  readelf -S ./llvm_btf_verify.o | grep BTF; \
+			  /bin/rm -f ./llvm_btf_verify.o)
+
+BPF_EXTRA_CFLAGS += -fno-stack-protector
+ifneq ($(BTF_LLVM_PROBE),)
+	BPF_EXTRA_CFLAGS += -g
+else
+ifneq ($(and $(BTF_LLC_PROBE),$(BTF_PAHOLE_PROBE),$(BTF_OBJCOPY_PROBE)),)
+	BPF_EXTRA_CFLAGS += -g
+	LLC_FLAGS += -mattr=dwarfris
+	DWARF2BTF = y
+endif
+endif
+endif
+
+# Trick to allow make to be run from this directory
+all:
+	$(MAKE) -C ../../ M=$(CURDIR) BPF_SAMPLES_PATH=$(CURDIR)
+
+clean:
+	$(MAKE) -C ../../ M=$(CURDIR) clean
+	@find $(CURDIR) -type f -name '*~' -delete
+
+$(LIBBPF): FORCE
+# Fix up variables inherited from Kbuild that tools/ build system won't like
+	$(MAKE) -C $(dir $@) RM='rm -rf' EXTRA_CFLAGS="$(TPROGS_CFLAGS)" \
+		LDFLAGS=$(TPROGS_LDFLAGS) srctree=$(BPF_SAMPLES_PATH)/../../ O=
+
+$(obj)/syscall_nrs.h:	$(obj)/syscall_nrs.s FORCE
+	$(call filechk,offsets,__SYSCALL_NRS_H__)
+
+targets += syscall_nrs.s
+clean-files += syscall_nrs.h
+
+FORCE:
+
+
+# Verify LLVM compiler tools are available and bpf target is supported by llc
+.PHONY: verify_cmds verify_target_bpf $(CLANG) $(LLC)
+
+verify_cmds: $(CLANG) $(LLC)
+	@for TOOL in $^ ; do \
+		if ! (which -- "$${TOOL}" > /dev/null 2>&1); then \
+			echo "*** ERROR: Cannot find LLVM tool $${TOOL}" ;\
+			exit 1; \
+		else true; fi; \
+	done
+
+verify_target_bpf: verify_cmds
+	@if ! (${LLC} -march=bpf -mattr=help > /dev/null 2>&1); then \
+		echo "*** ERROR: LLVM (${LLC}) does not support 'bpf' target" ;\
+		echo "   NOTICE: LLVM version >= 3.7.1 required" ;\
+		exit 2; \
+	else true; fi
+
+$(BPF_SAMPLES_PATH)/*.c: verify_target_bpf $(LIBBPF)
+$(src)/*.c: verify_target_bpf $(LIBBPF)
+
+$(obj)/tracex5_kern.o: $(obj)/syscall_nrs.h
+$(obj)/hbm_out_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
+$(obj)/hbm.o: $(src)/hbm.h
+$(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
+
+-include $(BPF_SAMPLES_PATH)/Makefile.target
+
+# asm/sysreg.h - inline assembly used by it is incompatible with llvm.
+# But, there is no easy way to fix it, so just exclude it since it is
+# useless for BPF samples.
+# below we use long chain of commands, clang | opt | llvm-dis | llc,
+# to generate final object file. 'clang' compiles the source into IR
+# with native target, e.g., x64, arm64, etc. 'opt' does bpf CORE IR builtin
+# processing (llvm12) and IR optimizations. 'llvm-dis' converts
+# 'opt' output to IR, and finally 'llc' generates bpf byte code.
+$(obj)/%.o: $(src)/%.c
+	@echo "  CLANG-bpf " $@
+	$(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(BPF_EXTRA_CFLAGS) \
+		-I$(obj) -I$(srctree)/tools/testing/selftests/bpf/ \
+		-I$(srctree)/tools/lib/ \
+		-D__KERNEL__ -D__BPF_TRACING__ -Wno-unused-value -Wno-pointer-sign \
+		-D__TARGET_ARCH_$(SRCARCH) -Wno-compare-distinct-pointer-types \
+		-Wno-gnu-variable-sized-type-not-at-end \
+		-Wno-address-of-packed-member -Wno-tautological-compare \
+		-Wno-unknown-warning-option $(CLANG_ARCH_ARGS) \
+		-I$(srctree)/samples/bpf/ -include asm_goto_workaround.h \
+		-O2 -emit-llvm -Xclang -disable-llvm-passes -c $< -o - | \
+		$(OPT) -O2 -mtriple=bpf-pc-linux | $(LLVM_DIS) | \
+		$(LLC) -march=bpf $(LLC_FLAGS) -filetype=obj -o $@
+ifeq ($(DWARF2BTF),y)
+	$(BTF_PAHOLE) -J $@
+endif
diff --git a/samples/bpf/Makefile.target b/samples/bpf/Makefile.target
new file mode 100644
index 000000000..7621f55e2
--- /dev/null
+++ b/samples/bpf/Makefile.target
@@ -0,0 +1,75 @@
+# SPDX-License-Identifier: GPL-2.0
+# ==========================================================================
+# Building binaries on the host system
+# Binaries are not used during the compilation of the kernel, and intended
+# to be build for target board, target board can be host of course. Added to
+# build binaries to run not on host system.
+#
+# Sample syntax
+# tprogs-y := xsk_example
+# Will compile xsk_example.c and create an executable named xsk_example
+#
+# tprogs-y    := xdpsock
+# xdpsock-objs := xdpsock_1.o xdpsock_2.o
+# Will compile xdpsock_1.c and xdpsock_2.c, and then link the executable
+# xdpsock, based on xdpsock_1.o and xdpsock_2.o
+#
+# Derived from scripts/Makefile.host
+#
+__tprogs := $(sort $(tprogs-y))
+
+# C code
+# Executables compiled from a single .c file
+tprog-csingle	:= $(foreach m,$(__tprogs), \
+			$(if $($(m)-objs),,$(m)))
+
+# C executables linked based on several .o files
+tprog-cmulti	:= $(foreach m,$(__tprogs),\
+			$(if $($(m)-objs),$(m)))
+
+# Object (.o) files compiled from .c files
+tprog-cobjs	:= $(sort $(foreach m,$(__tprogs),$($(m)-objs)))
+
+tprog-csingle	:= $(addprefix $(obj)/,$(tprog-csingle))
+tprog-cmulti	:= $(addprefix $(obj)/,$(tprog-cmulti))
+tprog-cobjs	:= $(addprefix $(obj)/,$(tprog-cobjs))
+
+#####
+# Handle options to gcc. Support building with separate output directory
+
+_tprogc_flags   = $(TPROGS_CFLAGS) \
+                 $(TPROGCFLAGS_$(basetarget).o)
+
+# $(objtree)/$(obj) for including generated headers from checkin source files
+ifeq ($(KBUILD_EXTMOD),)
+ifdef building_out_of_srctree
+_tprogc_flags   += -I $(objtree)/$(obj)
+endif
+endif
+
+tprogc_flags    = -Wp,-MD,$(depfile) $(_tprogc_flags)
+
+# Create executable from a single .c file
+# tprog-csingle -> Executable
+quiet_cmd_tprog-csingle 	= CC  $@
+      cmd_tprog-csingle	= $(CC) $(tprogc_flags) $(TPROGS_LDFLAGS) -o $@ $< \
+		$(TPROGS_LDLIBS) $(TPROGLDLIBS_$(@F))
+$(tprog-csingle): $(obj)/%: $(src)/%.c FORCE
+	$(call if_changed_dep,tprog-csingle)
+
+# Link an executable based on list of .o files, all plain c
+# tprog-cmulti -> executable
+quiet_cmd_tprog-cmulti	= LD  $@
+      cmd_tprog-cmulti	= $(CC) $(tprogc_flags) $(TPROGS_LDFLAGS) -o $@ \
+			  $(addprefix $(obj)/,$($(@F)-objs)) \
+			  $(TPROGS_LDLIBS) $(TPROGLDLIBS_$(@F))
+$(tprog-cmulti): $(tprog-cobjs) FORCE
+	$(call if_changed,tprog-cmulti)
+$(call multi_depend, $(tprog-cmulti), , -objs)
+
+# Create .o file from a single .c file
+# tprog-cobjs -> .o
+quiet_cmd_tprog-cobjs	= CC  $@
+      cmd_tprog-cobjs	= $(CC) $(tprogc_flags) -c -o $@ $<
+$(tprog-cobjs): $(obj)/%.o: $(src)/%.c FORCE
+	$(call if_changed_dep,tprog-cobjs)
diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst
new file mode 100644
index 000000000..dd34b2d26
--- /dev/null
+++ b/samples/bpf/README.rst
@@ -0,0 +1,105 @@
+eBPF sample programs
+====================
+
+This directory contains a test stubs, verifier test-suite and examples
+for using eBPF. The examples use libbpf from tools/lib/bpf.
+
+Build dependencies
+==================
+
+Compiling requires having installed:
+ * clang >= version 3.4.0
+ * llvm >= version 3.7.1
+
+Note that LLVM's tool 'llc' must support target 'bpf', list version
+and supported targets with command: ``llc --version``
+
+Clean and configuration
+-----------------------
+
+It can be needed to clean tools, samples or kernel before trying new arch or
+after some changes (on demand)::
+
+ make -C tools clean
+ make -C samples/bpf clean
+ make clean
+
+Configure kernel, defconfig for instance::
+
+ make defconfig
+
+Kernel headers
+--------------
+
+There are usually dependencies to header files of the current kernel.
+To avoid installing devel kernel headers system wide, as a normal
+user, simply call::
+
+ make headers_install
+
+This will creates a local "usr/include" directory in the git/build top
+level directory, that the make system automatically pickup first.
+
+Compiling
+=========
+
+For building the BPF samples, issue the below command from the kernel
+top level directory::
+
+ make M=samples/bpf
+
+It is also possible to call make from this directory.  This will just
+hide the invocation of make as above.
+
+Manually compiling LLVM with 'bpf' support
+------------------------------------------
+
+Since version 3.7.0, LLVM adds a proper LLVM backend target for the
+BPF bytecode architecture.
+
+By default llvm will build all non-experimental backends including bpf.
+To generate a smaller llc binary one can use::
+
+ -DLLVM_TARGETS_TO_BUILD="BPF"
+
+Quick sniplet for manually compiling LLVM and clang
+(build dependencies are cmake and gcc-c++)::
+
+ $ git clone http://llvm.org/git/llvm.git
+ $ cd llvm/tools
+ $ git clone --depth 1 http://llvm.org/git/clang.git
+ $ cd ..; mkdir build; cd build
+ $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86"
+ $ make -j $(getconf _NPROCESSORS_ONLN)
+
+It is also possible to point make to the newly compiled 'llc' or
+'clang' command via redefining LLC or CLANG on the make command line::
+
+ make M=samples/bpf LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
+
+Cross compiling samples
+-----------------------
+In order to cross-compile, say for arm64 targets, export CROSS_COMPILE and ARCH
+environment variables before calling make. But do this before clean,
+cofiguration and header install steps described above. This will direct make to
+build samples for the cross target::
+
+ export ARCH=arm64
+ export CROSS_COMPILE="aarch64-linux-gnu-"
+
+Headers can be also installed on RFS of target board if need to keep them in
+sync (not necessarily and it creates a local "usr/include" directory also)::
+
+ make INSTALL_HDR_PATH=~/some_sysroot/usr headers_install
+
+Pointing LLC and CLANG is not necessarily if it's installed on HOST and have
+in its targets appropriate arm64 arch (usually it has several arches).
+Build samples::
+
+ make M=samples/bpf
+
+Or build samples with SYSROOT if some header or library is absent in toolchain,
+say libelf, providing address to file system containing headers and libs,
+can be RFS of target board::
+
+ make M=samples/bpf SYSROOT=~/some_sysroot
diff --git a/samples/bpf/asm_goto_workaround.h b/samples/bpf/asm_goto_workaround.h
new file mode 100644
index 000000000..7048bb359
--- /dev/null
+++ b/samples/bpf/asm_goto_workaround.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2019 Facebook */
+#ifndef __ASM_GOTO_WORKAROUND_H
+#define __ASM_GOTO_WORKAROUND_H
+
+/*
+ * This will bring in asm_volatile_goto and asm_inline macro definitions
+ * if enabled by compiler and config options.
+ */
+#include <linux/types.h>
+
+#ifdef asm_volatile_goto
+#undef asm_volatile_goto
+#define asm_volatile_goto(x...) asm volatile("invalid use of asm_volatile_goto")
+#endif
+
+/*
+ * asm_inline is defined as asm __inline in "include/linux/compiler_types.h"
+ * if supported by the kernel's CC (i.e CONFIG_CC_HAS_ASM_INLINE) which is not
+ * supported by CLANG.
+ */
+#ifdef asm_inline
+#undef asm_inline
+#define asm_inline asm
+#endif
+
+#define volatile(x...) volatile("")
+#endif
diff --git a/samples/bpf/bpf_insn.h b/samples/bpf/bpf_insn.h
new file mode 100644
index 000000000..544237980
--- /dev/null
+++ b/samples/bpf/bpf_insn.h
@@ -0,0 +1,217 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* eBPF instruction mini library */
+#ifndef __BPF_INSN_H
+#define __BPF_INSN_H
+
+struct bpf_insn;
+
+/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
+
+#define BPF_ALU64_REG(OP, DST, SRC)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,	\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = 0,					\
+		.imm   = 0 })
+
+#define BPF_ALU32_REG(OP, DST, SRC)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU | BPF_OP(OP) | BPF_X,		\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = 0,					\
+		.imm   = 0 })
+
+/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
+
+#define BPF_ALU64_IMM(OP, DST, IMM)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,	\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = IMM })
+
+#define BPF_ALU32_IMM(OP, DST, IMM)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU | BPF_OP(OP) | BPF_K,		\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = IMM })
+
+/* Short form of mov, dst_reg = src_reg */
+
+#define BPF_MOV64_REG(DST, SRC)					\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU64 | BPF_MOV | BPF_X,		\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = 0,					\
+		.imm   = 0 })
+
+#define BPF_MOV32_REG(DST, SRC)					\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU | BPF_MOV | BPF_X,		\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = 0,					\
+		.imm   = 0 })
+
+/* Short form of mov, dst_reg = imm32 */
+
+#define BPF_MOV64_IMM(DST, IMM)					\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU64 | BPF_MOV | BPF_K,		\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = IMM })
+
+#define BPF_MOV32_IMM(DST, IMM)					\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU | BPF_MOV | BPF_K,		\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = IMM })
+
+/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
+#define BPF_LD_IMM64(DST, IMM)					\
+	BPF_LD_IMM64_RAW(DST, 0, IMM)
+
+#define BPF_LD_IMM64_RAW(DST, SRC, IMM)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_LD | BPF_DW | BPF_IMM,		\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = 0,					\
+		.imm   = (__u32) (IMM) }),			\
+	((struct bpf_insn) {					\
+		.code  = 0, /* zero is reserved opcode */	\
+		.dst_reg = 0,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = ((__u64) (IMM)) >> 32 })
+
+#ifndef BPF_PSEUDO_MAP_FD
+# define BPF_PSEUDO_MAP_FD	1
+#endif
+
+/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
+#define BPF_LD_MAP_FD(DST, MAP_FD)				\
+	BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
+
+
+/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
+
+#define BPF_LD_ABS(SIZE, IMM)					\
+	((struct bpf_insn) {					\
+		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,	\
+		.dst_reg = 0,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = IMM })
+
+/* Memory load, dst_reg = *(uint *) (src_reg + off16) */
+
+#define BPF_LDX_MEM(SIZE, DST, SRC, OFF)			\
+	((struct bpf_insn) {					\
+		.code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,	\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF,					\
+		.imm   = 0 })
+
+/* Memory store, *(uint *) (dst_reg + off16) = src_reg */
+
+#define BPF_STX_MEM(SIZE, DST, SRC, OFF)			\
+	((struct bpf_insn) {					\
+		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,	\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF,					\
+		.imm   = 0 })
+
+/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
+
+#define BPF_STX_XADD(SIZE, DST, SRC, OFF)			\
+	((struct bpf_insn) {					\
+		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,	\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF,					\
+		.imm   = 0 })
+
+/* Memory store, *(uint *) (dst_reg + off16) = imm32 */
+
+#define BPF_ST_MEM(SIZE, DST, OFF, IMM)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,	\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = OFF,					\
+		.imm   = IMM })
+
+/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
+
+#define BPF_JMP_REG(OP, DST, SRC, OFF)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_JMP | BPF_OP(OP) | BPF_X,		\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF,					\
+		.imm   = 0 })
+
+/* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */
+
+#define BPF_JMP32_REG(OP, DST, SRC, OFF)			\
+	((struct bpf_insn) {					\
+		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_X,	\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF,					\
+		.imm   = 0 })
+
+/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
+
+#define BPF_JMP_IMM(OP, DST, IMM, OFF)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_JMP | BPF_OP(OP) | BPF_K,		\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = OFF,					\
+		.imm   = IMM })
+
+/* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */
+
+#define BPF_JMP32_IMM(OP, DST, IMM, OFF)			\
+	((struct bpf_insn) {					\
+		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_K,	\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = OFF,					\
+		.imm   = IMM })
+
+/* Raw code statement block */
+
+#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)			\
+	((struct bpf_insn) {					\
+		.code  = CODE,					\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF,					\
+		.imm   = IMM })
+
+/* Program exit */
+
+#define BPF_EXIT_INSN()						\
+	((struct bpf_insn) {					\
+		.code  = BPF_JMP | BPF_EXIT,			\
+		.dst_reg = 0,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = 0 })
+
+#endif
diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c
new file mode 100644
index 000000000..c5ad528f0
--- /dev/null
+++ b/samples/bpf/bpf_load.c
@@ -0,0 +1,667 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <libelf.h>
+#include <gelf.h>
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/perf_event.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <linux/types.h>
+#include <sys/socket.h>
+#include <sys/syscall.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <poll.h>
+#include <ctype.h>
+#include <assert.h>
+#include <bpf/bpf.h>
+#include "bpf_load.h"
+#include "perf-sys.h"
+
+#define DEBUGFS "/sys/kernel/debug/tracing/"
+
+static char license[128];
+static int kern_version;
+static bool processed_sec[128];
+char bpf_log_buf[BPF_LOG_BUF_SIZE];
+int map_fd[MAX_MAPS];
+int prog_fd[MAX_PROGS];
+int event_fd[MAX_PROGS];
+int prog_cnt;
+int prog_array_fd = -1;
+
+struct bpf_map_data map_data[MAX_MAPS];
+int map_data_count;
+
+static int populate_prog_array(const char *event, int prog_fd)
+{
+	int ind = atoi(event), err;
+
+	err = bpf_map_update_elem(prog_array_fd, &ind, &prog_fd, BPF_ANY);
+	if (err < 0) {
+		printf("failed to store prog_fd in prog_array\n");
+		return -1;
+	}
+	return 0;
+}
+
+static int write_kprobe_events(const char *val)
+{
+	int fd, ret, flags;
+
+	if (val == NULL)
+		return -1;
+	else if (val[0] == '\0')
+		flags = O_WRONLY | O_TRUNC;
+	else
+		flags = O_WRONLY | O_APPEND;
+
+	fd = open(DEBUGFS "kprobe_events", flags);
+
+	ret = write(fd, val, strlen(val));
+	close(fd);
+
+	return ret;
+}
+
+static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
+{
+	bool is_socket = strncmp(event, "socket", 6) == 0;
+	bool is_kprobe = strncmp(event, "kprobe/", 7) == 0;
+	bool is_kretprobe = strncmp(event, "kretprobe/", 10) == 0;
+	bool is_tracepoint = strncmp(event, "tracepoint/", 11) == 0;
+	bool is_raw_tracepoint = strncmp(event, "raw_tracepoint/", 15) == 0;
+	bool is_xdp = strncmp(event, "xdp", 3) == 0;
+	bool is_perf_event = strncmp(event, "perf_event", 10) == 0;
+	bool is_cgroup_skb = strncmp(event, "cgroup/skb", 10) == 0;
+	bool is_cgroup_sk = strncmp(event, "cgroup/sock", 11) == 0;
+	bool is_sockops = strncmp(event, "sockops", 7) == 0;
+	bool is_sk_skb = strncmp(event, "sk_skb", 6) == 0;
+	bool is_sk_msg = strncmp(event, "sk_msg", 6) == 0;
+	size_t insns_cnt = size / sizeof(struct bpf_insn);
+	enum bpf_prog_type prog_type;
+	char buf[256];
+	int fd, efd, err, id;
+	struct perf_event_attr attr = {};
+
+	attr.type = PERF_TYPE_TRACEPOINT;
+	attr.sample_type = PERF_SAMPLE_RAW;
+	attr.sample_period = 1;
+	attr.wakeup_events = 1;
+
+	if (is_socket) {
+		prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+	} else if (is_kprobe || is_kretprobe) {
+		prog_type = BPF_PROG_TYPE_KPROBE;
+	} else if (is_tracepoint) {
+		prog_type = BPF_PROG_TYPE_TRACEPOINT;
+	} else if (is_raw_tracepoint) {
+		prog_type = BPF_PROG_TYPE_RAW_TRACEPOINT;
+	} else if (is_xdp) {
+		prog_type = BPF_PROG_TYPE_XDP;
+	} else if (is_perf_event) {
+		prog_type = BPF_PROG_TYPE_PERF_EVENT;
+	} else if (is_cgroup_skb) {
+		prog_type = BPF_PROG_TYPE_CGROUP_SKB;
+	} else if (is_cgroup_sk) {
+		prog_type = BPF_PROG_TYPE_CGROUP_SOCK;
+	} else if (is_sockops) {
+		prog_type = BPF_PROG_TYPE_SOCK_OPS;
+	} else if (is_sk_skb) {
+		prog_type = BPF_PROG_TYPE_SK_SKB;
+	} else if (is_sk_msg) {
+		prog_type = BPF_PROG_TYPE_SK_MSG;
+	} else {
+		printf("Unknown event '%s'\n", event);
+		return -1;
+	}
+
+	if (prog_cnt == MAX_PROGS)
+		return -1;
+
+	fd = bpf_load_program(prog_type, prog, insns_cnt, license, kern_version,
+			      bpf_log_buf, BPF_LOG_BUF_SIZE);
+	if (fd < 0) {
+		printf("bpf_load_program() err=%d\n%s", errno, bpf_log_buf);
+		return -1;
+	}
+
+	prog_fd[prog_cnt++] = fd;
+
+	if (is_xdp || is_perf_event || is_cgroup_skb || is_cgroup_sk)
+		return 0;
+
+	if (is_socket || is_sockops || is_sk_skb || is_sk_msg) {
+		if (is_socket)
+			event += 6;
+		else
+			event += 7;
+		if (*event != '/')
+			return 0;
+		event++;
+		if (!isdigit(*event)) {
+			printf("invalid prog number\n");
+			return -1;
+		}
+		return populate_prog_array(event, fd);
+	}
+
+	if (is_raw_tracepoint) {
+		efd = bpf_raw_tracepoint_open(event + 15, fd);
+		if (efd < 0) {
+			printf("tracepoint %s %s\n", event + 15, strerror(errno));
+			return -1;
+		}
+		event_fd[prog_cnt - 1] = efd;
+		return 0;
+	}
+
+	if (is_kprobe || is_kretprobe) {
+		bool need_normal_check = true;
+		const char *event_prefix = "";
+
+		if (is_kprobe)
+			event += 7;
+		else
+			event += 10;
+
+		if (*event == 0) {
+			printf("event name cannot be empty\n");
+			return -1;
+		}
+
+		if (isdigit(*event))
+			return populate_prog_array(event, fd);
+
+#ifdef __x86_64__
+		if (strncmp(event, "sys_", 4) == 0) {
+			snprintf(buf, sizeof(buf), "%c:__x64_%s __x64_%s",
+				is_kprobe ? 'p' : 'r', event, event);
+			err = write_kprobe_events(buf);
+			if (err >= 0) {
+				need_normal_check = false;
+				event_prefix = "__x64_";
+			}
+		}
+#endif
+		if (need_normal_check) {
+			snprintf(buf, sizeof(buf), "%c:%s %s",
+				is_kprobe ? 'p' : 'r', event, event);
+			err = write_kprobe_events(buf);
+			if (err < 0) {
+				printf("failed to create kprobe '%s' error '%s'\n",
+				       event, strerror(errno));
+				return -1;
+			}
+		}
+
+		strcpy(buf, DEBUGFS);
+		strcat(buf, "events/kprobes/");
+		strcat(buf, event_prefix);
+		strcat(buf, event);
+		strcat(buf, "/id");
+	} else if (is_tracepoint) {
+		event += 11;
+
+		if (*event == 0) {
+			printf("event name cannot be empty\n");
+			return -1;
+		}
+		strcpy(buf, DEBUGFS);
+		strcat(buf, "events/");
+		strcat(buf, event);
+		strcat(buf, "/id");
+	}
+
+	efd = open(buf, O_RDONLY, 0);
+	if (efd < 0) {
+		printf("failed to open event %s\n", event);
+		return -1;
+	}
+
+	err = read(efd, buf, sizeof(buf));
+	if (err < 0 || err >= sizeof(buf)) {
+		printf("read from '%s' failed '%s'\n", event, strerror(errno));
+		return -1;
+	}
+
+	close(efd);
+
+	buf[err] = 0;
+	id = atoi(buf);
+	attr.config = id;
+
+	efd = sys_perf_event_open(&attr, -1/*pid*/, 0/*cpu*/, -1/*group_fd*/, 0);
+	if (efd < 0) {
+		printf("event %d fd %d err %s\n", id, efd, strerror(errno));
+		return -1;
+	}
+	event_fd[prog_cnt - 1] = efd;
+	err = ioctl(efd, PERF_EVENT_IOC_ENABLE, 0);
+	if (err < 0) {
+		printf("ioctl PERF_EVENT_IOC_ENABLE failed err %s\n",
+		       strerror(errno));
+		return -1;
+	}
+	err = ioctl(efd, PERF_EVENT_IOC_SET_BPF, fd);
+	if (err < 0) {
+		printf("ioctl PERF_EVENT_IOC_SET_BPF failed err %s\n",
+		       strerror(errno));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int load_maps(struct bpf_map_data *maps, int nr_maps,
+		     fixup_map_cb fixup_map)
+{
+	int i, numa_node;
+
+	for (i = 0; i < nr_maps; i++) {
+		if (fixup_map) {
+			fixup_map(&maps[i], i);
+			/* Allow userspace to assign map FD prior to creation */
+			if (maps[i].fd != -1) {
+				map_fd[i] = maps[i].fd;
+				continue;
+			}
+		}
+
+		numa_node = maps[i].def.map_flags & BPF_F_NUMA_NODE ?
+			maps[i].def.numa_node : -1;
+
+		if (maps[i].def.type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
+		    maps[i].def.type == BPF_MAP_TYPE_HASH_OF_MAPS) {
+			int inner_map_fd = map_fd[maps[i].def.inner_map_idx];
+
+			map_fd[i] = bpf_create_map_in_map_node(maps[i].def.type,
+							maps[i].name,
+							maps[i].def.key_size,
+							inner_map_fd,
+							maps[i].def.max_entries,
+							maps[i].def.map_flags,
+							numa_node);
+		} else {
+			map_fd[i] = bpf_create_map_node(maps[i].def.type,
+							maps[i].name,
+							maps[i].def.key_size,
+							maps[i].def.value_size,
+							maps[i].def.max_entries,
+							maps[i].def.map_flags,
+							numa_node);
+		}
+		if (map_fd[i] < 0) {
+			printf("failed to create map %d (%s): %d %s\n",
+			       i, maps[i].name, errno, strerror(errno));
+			return 1;
+		}
+		maps[i].fd = map_fd[i];
+
+		if (maps[i].def.type == BPF_MAP_TYPE_PROG_ARRAY)
+			prog_array_fd = map_fd[i];
+	}
+	return 0;
+}
+
+static int get_sec(Elf *elf, int i, GElf_Ehdr *ehdr, char **shname,
+		   GElf_Shdr *shdr, Elf_Data **data)
+{
+	Elf_Scn *scn;
+
+	scn = elf_getscn(elf, i);
+	if (!scn)
+		return 1;
+
+	if (gelf_getshdr(scn, shdr) != shdr)
+		return 2;
+
+	*shname = elf_strptr(elf, ehdr->e_shstrndx, shdr->sh_name);
+	if (!*shname || !shdr->sh_size)
+		return 3;
+
+	*data = elf_getdata(scn, 0);
+	if (!*data || elf_getdata(scn, *data) != NULL)
+		return 4;
+
+	return 0;
+}
+
+static int parse_relo_and_apply(Elf_Data *data, Elf_Data *symbols,
+				GElf_Shdr *shdr, struct bpf_insn *insn,
+				struct bpf_map_data *maps, int nr_maps)
+{
+	int i, nrels;
+
+	nrels = shdr->sh_size / shdr->sh_entsize;
+
+	for (i = 0; i < nrels; i++) {
+		GElf_Sym sym;
+		GElf_Rel rel;
+		unsigned int insn_idx;
+		bool match = false;
+		int j, map_idx;
+
+		gelf_getrel(data, i, &rel);
+
+		insn_idx = rel.r_offset / sizeof(struct bpf_insn);
+
+		gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym);
+
+		if (insn[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
+			printf("invalid relo for insn[%d].code 0x%x\n",
+			       insn_idx, insn[insn_idx].code);
+			return 1;
+		}
+		insn[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
+
+		/* Match FD relocation against recorded map_data[] offset */
+		for (map_idx = 0; map_idx < nr_maps; map_idx++) {
+			if (maps[map_idx].elf_offset == sym.st_value) {
+				match = true;
+				break;
+			}
+		}
+		if (match) {
+			insn[insn_idx].imm = maps[map_idx].fd;
+		} else {
+			printf("invalid relo for insn[%d] no map_data match\n",
+			       insn_idx);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+static int cmp_symbols(const void *l, const void *r)
+{
+	const GElf_Sym *lsym = (const GElf_Sym *)l;
+	const GElf_Sym *rsym = (const GElf_Sym *)r;
+
+	if (lsym->st_value < rsym->st_value)
+		return -1;
+	else if (lsym->st_value > rsym->st_value)
+		return 1;
+	else
+		return 0;
+}
+
+static int load_elf_maps_section(struct bpf_map_data *maps, int maps_shndx,
+				 Elf *elf, Elf_Data *symbols, int strtabidx)
+{
+	int map_sz_elf, map_sz_copy;
+	bool validate_zero = false;
+	Elf_Data *data_maps;
+	int i, nr_maps;
+	GElf_Sym *sym;
+	Elf_Scn *scn;
+	int copy_sz;
+
+	if (maps_shndx < 0)
+		return -EINVAL;
+	if (!symbols)
+		return -EINVAL;
+
+	/* Get data for maps section via elf index */
+	scn = elf_getscn(elf, maps_shndx);
+	if (scn)
+		data_maps = elf_getdata(scn, NULL);
+	if (!scn || !data_maps) {
+		printf("Failed to get Elf_Data from maps section %d\n",
+		       maps_shndx);
+		return -EINVAL;
+	}
+
+	/* For each map get corrosponding symbol table entry */
+	sym = calloc(MAX_MAPS+1, sizeof(GElf_Sym));
+	for (i = 0, nr_maps = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
+		assert(nr_maps < MAX_MAPS+1);
+		if (!gelf_getsym(symbols, i, &sym[nr_maps]))
+			continue;
+		if (sym[nr_maps].st_shndx != maps_shndx)
+			continue;
+		/* Only increment iif maps section */
+		nr_maps++;
+	}
+
+	/* Align to map_fd[] order, via sort on offset in sym.st_value */
+	qsort(sym, nr_maps, sizeof(GElf_Sym), cmp_symbols);
+
+	/* Keeping compatible with ELF maps section changes
+	 * ------------------------------------------------
+	 * The program size of struct bpf_load_map_def is known by loader
+	 * code, but struct stored in ELF file can be different.
+	 *
+	 * Unfortunately sym[i].st_size is zero.  To calculate the
+	 * struct size stored in the ELF file, assume all struct have
+	 * the same size, and simply divide with number of map
+	 * symbols.
+	 */
+	map_sz_elf = data_maps->d_size / nr_maps;
+	map_sz_copy = sizeof(struct bpf_load_map_def);
+	if (map_sz_elf < map_sz_copy) {
+		/*
+		 * Backward compat, loading older ELF file with
+		 * smaller struct, keeping remaining bytes zero.
+		 */
+		map_sz_copy = map_sz_elf;
+	} else if (map_sz_elf > map_sz_copy) {
+		/*
+		 * Forward compat, loading newer ELF file with larger
+		 * struct with unknown features. Assume zero means
+		 * feature not used.  Thus, validate rest of struct
+		 * data is zero.
+		 */
+		validate_zero = true;
+	}
+
+	/* Memcpy relevant part of ELF maps data to loader maps */
+	for (i = 0; i < nr_maps; i++) {
+		struct bpf_load_map_def *def;
+		unsigned char *addr, *end;
+		const char *map_name;
+		size_t offset;
+
+		map_name = elf_strptr(elf, strtabidx, sym[i].st_name);
+		maps[i].name = strdup(map_name);
+		if (!maps[i].name) {
+			printf("strdup(%s): %s(%d)\n", map_name,
+			       strerror(errno), errno);
+			free(sym);
+			return -errno;
+		}
+
+		/* Symbol value is offset into ELF maps section data area */
+		offset = sym[i].st_value;
+		def = (struct bpf_load_map_def *)(data_maps->d_buf + offset);
+		maps[i].elf_offset = offset;
+		memset(&maps[i].def, 0, sizeof(struct bpf_load_map_def));
+		memcpy(&maps[i].def, def, map_sz_copy);
+
+		/* Verify no newer features were requested */
+		if (validate_zero) {
+			addr = (unsigned char *) def + map_sz_copy;
+			end  = (unsigned char *) def + map_sz_elf;
+			for (; addr < end; addr++) {
+				if (*addr != 0) {
+					free(sym);
+					return -EFBIG;
+				}
+			}
+		}
+	}
+
+	free(sym);
+	return nr_maps;
+}
+
+static int do_load_bpf_file(const char *path, fixup_map_cb fixup_map)
+{
+	int fd, i, ret, maps_shndx = -1, strtabidx = -1;
+	Elf *elf;
+	GElf_Ehdr ehdr;
+	GElf_Shdr shdr, shdr_prog;
+	Elf_Data *data, *data_prog, *data_maps = NULL, *symbols = NULL;
+	char *shname, *shname_prog;
+	int nr_maps = 0;
+
+	/* reset global variables */
+	kern_version = 0;
+	memset(license, 0, sizeof(license));
+	memset(processed_sec, 0, sizeof(processed_sec));
+
+	if (elf_version(EV_CURRENT) == EV_NONE)
+		return 1;
+
+	fd = open(path, O_RDONLY, 0);
+	if (fd < 0)
+		return 1;
+
+	elf = elf_begin(fd, ELF_C_READ, NULL);
+
+	if (!elf)
+		return 1;
+
+	if (gelf_getehdr(elf, &ehdr) != &ehdr)
+		return 1;
+
+	/* clear all kprobes */
+	i = write_kprobe_events("");
+
+	/* scan over all elf sections to get license and map info */
+	for (i = 1; i < ehdr.e_shnum; i++) {
+
+		if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
+			continue;
+
+		if (0) /* helpful for llvm debugging */
+			printf("section %d:%s data %p size %zd link %d flags %d\n",
+			       i, shname, data->d_buf, data->d_size,
+			       shdr.sh_link, (int) shdr.sh_flags);
+
+		if (strcmp(shname, "license") == 0) {
+			processed_sec[i] = true;
+			memcpy(license, data->d_buf, data->d_size);
+		} else if (strcmp(shname, "version") == 0) {
+			processed_sec[i] = true;
+			if (data->d_size != sizeof(int)) {
+				printf("invalid size of version section %zd\n",
+				       data->d_size);
+				return 1;
+			}
+			memcpy(&kern_version, data->d_buf, sizeof(int));
+		} else if (strcmp(shname, "maps") == 0) {
+			int j;
+
+			maps_shndx = i;
+			data_maps = data;
+			for (j = 0; j < MAX_MAPS; j++)
+				map_data[j].fd = -1;
+		} else if (shdr.sh_type == SHT_SYMTAB) {
+			strtabidx = shdr.sh_link;
+			symbols = data;
+		}
+	}
+
+	ret = 1;
+
+	if (!symbols) {
+		printf("missing SHT_SYMTAB section\n");
+		goto done;
+	}
+
+	if (data_maps) {
+		nr_maps = load_elf_maps_section(map_data, maps_shndx,
+						elf, symbols, strtabidx);
+		if (nr_maps < 0) {
+			printf("Error: Failed loading ELF maps (errno:%d):%s\n",
+			       nr_maps, strerror(-nr_maps));
+			goto done;
+		}
+		if (load_maps(map_data, nr_maps, fixup_map))
+			goto done;
+		map_data_count = nr_maps;
+
+		processed_sec[maps_shndx] = true;
+	}
+
+	/* process all relo sections, and rewrite bpf insns for maps */
+	for (i = 1; i < ehdr.e_shnum; i++) {
+		if (processed_sec[i])
+			continue;
+
+		if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
+			continue;
+
+		if (shdr.sh_type == SHT_REL) {
+			struct bpf_insn *insns;
+
+			/* locate prog sec that need map fixup (relocations) */
+			if (get_sec(elf, shdr.sh_info, &ehdr, &shname_prog,
+				    &shdr_prog, &data_prog))
+				continue;
+
+			if (shdr_prog.sh_type != SHT_PROGBITS ||
+			    !(shdr_prog.sh_flags & SHF_EXECINSTR))
+				continue;
+
+			insns = (struct bpf_insn *) data_prog->d_buf;
+			processed_sec[i] = true; /* relo section */
+
+			if (parse_relo_and_apply(data, symbols, &shdr, insns,
+						 map_data, nr_maps))
+				continue;
+		}
+	}
+
+	/* load programs */
+	for (i = 1; i < ehdr.e_shnum; i++) {
+
+		if (processed_sec[i])
+			continue;
+
+		if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
+			continue;
+
+		if (memcmp(shname, "kprobe/", 7) == 0 ||
+		    memcmp(shname, "kretprobe/", 10) == 0 ||
+		    memcmp(shname, "tracepoint/", 11) == 0 ||
+		    memcmp(shname, "raw_tracepoint/", 15) == 0 ||
+		    memcmp(shname, "xdp", 3) == 0 ||
+		    memcmp(shname, "perf_event", 10) == 0 ||
+		    memcmp(shname, "socket", 6) == 0 ||
+		    memcmp(shname, "cgroup/", 7) == 0 ||
+		    memcmp(shname, "sockops", 7) == 0 ||
+		    memcmp(shname, "sk_skb", 6) == 0 ||
+		    memcmp(shname, "sk_msg", 6) == 0) {
+			ret = load_and_attach(shname, data->d_buf,
+					      data->d_size);
+			if (ret != 0)
+				goto done;
+		}
+	}
+
+done:
+	close(fd);
+	return ret;
+}
+
+int load_bpf_file(char *path)
+{
+	return do_load_bpf_file(path, NULL);
+}
+
+int load_bpf_file_fixup_map(const char *path, fixup_map_cb fixup_map)
+{
+	return do_load_bpf_file(path, fixup_map);
+}
diff --git a/samples/bpf/bpf_load.h b/samples/bpf/bpf_load.h
new file mode 100644
index 000000000..4fcd258c6
--- /dev/null
+++ b/samples/bpf/bpf_load.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __BPF_LOAD_H
+#define __BPF_LOAD_H
+
+#include <bpf/bpf.h>
+
+#define MAX_MAPS 32
+#define MAX_PROGS 32
+
+struct bpf_load_map_def {
+	unsigned int type;
+	unsigned int key_size;
+	unsigned int value_size;
+	unsigned int max_entries;
+	unsigned int map_flags;
+	unsigned int inner_map_idx;
+	unsigned int numa_node;
+};
+
+struct bpf_map_data {
+	int fd;
+	char *name;
+	size_t elf_offset;
+	struct bpf_load_map_def def;
+};
+
+typedef void (*fixup_map_cb)(struct bpf_map_data *map, int idx);
+
+extern int prog_fd[MAX_PROGS];
+extern int event_fd[MAX_PROGS];
+extern char bpf_log_buf[BPF_LOG_BUF_SIZE];
+extern int prog_cnt;
+
+/* There is a one-to-one mapping between map_fd[] and map_data[].
+ * The map_data[] just contains more rich info on the given map.
+ */
+extern int map_fd[MAX_MAPS];
+extern struct bpf_map_data map_data[MAX_MAPS];
+extern int map_data_count;
+
+/* parses elf file compiled by llvm .c->.o
+ * . parses 'maps' section and creates maps via BPF syscall
+ * . parses 'license' section and passes it to syscall
+ * . parses elf relocations for BPF maps and adjusts BPF_LD_IMM64 insns by
+ *   storing map_fd into insn->imm and marking such insns as BPF_PSEUDO_MAP_FD
+ * . loads eBPF programs via BPF syscall
+ *
+ * One ELF file can contain multiple BPF programs which will be loaded
+ * and their FDs stored stored in prog_fd array
+ *
+ * returns zero on success
+ */
+int load_bpf_file(char *path);
+int load_bpf_file_fixup_map(const char *path, fixup_map_cb fixup_map);
+
+int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
+#endif
diff --git a/samples/bpf/cookie_uid_helper_example.c b/samples/bpf/cookie_uid_helper_example.c
new file mode 100644
index 000000000..deb0e3e03
--- /dev/null
+++ b/samples/bpf/cookie_uid_helper_example.c
@@ -0,0 +1,323 @@
+/* This test is a demo of using get_socket_uid and get_socket_cookie
+ * helper function to do per socket based network traffic monitoring.
+ * It requires iptables version higher then 1.6.1. to load pinned eBPF
+ * program into the xt_bpf match.
+ *
+ * TEST:
+ * ./run_cookie_uid_helper_example.sh -option
+ * option:
+ *	-t: do traffic monitoring test, the program will continuously
+ * print out network traffic happens after program started A sample
+ * output is shown below:
+ *
+ * cookie: 877, uid: 0x3e8, Pakcet Count: 20, Bytes Count: 11058
+ * cookie: 132, uid: 0x0, Pakcet Count: 2, Bytes Count: 286
+ * cookie: 812, uid: 0x3e8, Pakcet Count: 3, Bytes Count: 1726
+ * cookie: 802, uid: 0x3e8, Pakcet Count: 2, Bytes Count: 104
+ * cookie: 877, uid: 0x3e8, Pakcet Count: 20, Bytes Count: 11058
+ * cookie: 831, uid: 0x3e8, Pakcet Count: 2, Bytes Count: 104
+ * cookie: 0, uid: 0x0, Pakcet Count: 6, Bytes Count: 712
+ * cookie: 880, uid: 0xfffe, Pakcet Count: 1, Bytes Count: 70
+ *
+ *	-s: do getsockopt SO_COOKIE test, the program will set up a pair of
+ * UDP sockets and send packets between them. And read out the traffic data
+ * directly from the ebpf map based on the socket cookie.
+ *
+ * Clean up: if using shell script, the script file will delete the iptables
+ * rule and unmount the bpf program when exit. Else the iptables rule need
+ * to be deleted by hand, see run_cookie_uid_helper_example.sh for detail.
+ */
+
+#define _GNU_SOURCE
+
+#define offsetof(type, member)	__builtin_offsetof(type, member)
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <error.h>
+#include <limits.h>
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <net/if.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <bpf/bpf.h>
+#include "bpf_insn.h"
+
+#define PORT 8888
+
+struct stats {
+	uint32_t uid;
+	uint64_t packets;
+	uint64_t bytes;
+};
+
+static int map_fd, prog_fd;
+
+static bool test_finish;
+
+static void maps_create(void)
+{
+	map_fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(uint32_t),
+				sizeof(struct stats), 100, 0);
+	if (map_fd < 0)
+		error(1, errno, "map create failed!\n");
+}
+
+static void prog_load(void)
+{
+	static char log_buf[1 << 16];
+
+	struct bpf_insn prog[] = {
+		/*
+		 * Save sk_buff for future usage. value stored in R6 to R10 will
+		 * not be reset after a bpf helper function call.
+		 */
+		BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+		/*
+		 * pc1: BPF_FUNC_get_socket_cookie takes one parameter,
+		 * R1: sk_buff
+		 */
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				BPF_FUNC_get_socket_cookie),
+		/* pc2-4: save &socketCookie to r7 for future usage*/
+		BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
+		BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
+		/*
+		 * pc5-8: set up the registers for BPF_FUNC_map_lookup_elem,
+		 * it takes two parameters (R1: map_fd,  R2: &socket_cookie)
+		 */
+		BPF_LD_MAP_FD(BPF_REG_1, map_fd),
+		BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				BPF_FUNC_map_lookup_elem),
+		/*
+		 * pc9. if r0 != 0x0, go to pc+14, since we have the cookie
+		 * stored already
+		 * Otherwise do pc10-22 to setup a new data entry.
+		 */
+		BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 14),
+		BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				BPF_FUNC_get_socket_uid),
+		/*
+		 * Place a struct stats in the R10 stack and sequentially
+		 * place the member value into the memory. Packets value
+		 * is set by directly place a IMM value 1 into the stack.
+		 */
+		BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0,
+			    -32 + (__s16)offsetof(struct stats, uid)),
+		BPF_ST_MEM(BPF_DW, BPF_REG_10,
+			   -32 + (__s16)offsetof(struct stats, packets), 1),
+		/*
+		 * __sk_buff is a special struct used for eBPF program to
+		 * directly access some sk_buff field.
+		 */
+		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6,
+				offsetof(struct __sk_buff, len)),
+		BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1,
+			    -32 + (__s16)offsetof(struct stats, bytes)),
+		/*
+		 * add new map entry using BPF_FUNC_map_update_elem, it takes
+		 * 4 parameters (R1: map_fd, R2: &socket_cookie, R3: &stats,
+		 * R4: flags)
+		 */
+		BPF_LD_MAP_FD(BPF_REG_1, map_fd),
+		BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
+		BPF_MOV64_REG(BPF_REG_3, BPF_REG_10),
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -32),
+		BPF_MOV64_IMM(BPF_REG_4, 0),
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				BPF_FUNC_map_update_elem),
+		BPF_JMP_IMM(BPF_JA, 0, 0, 5),
+		/*
+		 * pc24-30 update the packet info to a exist data entry, it can
+		 * be done by directly write to pointers instead of using
+		 * BPF_FUNC_map_update_elem helper function
+		 */
+		BPF_MOV64_REG(BPF_REG_9, BPF_REG_0),
+		BPF_MOV64_IMM(BPF_REG_1, 1),
+		BPF_STX_XADD(BPF_DW, BPF_REG_9, BPF_REG_1,
+				offsetof(struct stats, packets)),
+		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6,
+				offsetof(struct __sk_buff, len)),
+		BPF_STX_XADD(BPF_DW, BPF_REG_9, BPF_REG_1,
+				offsetof(struct stats, bytes)),
+		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6,
+				offsetof(struct __sk_buff, len)),
+		BPF_EXIT_INSN(),
+	};
+	prog_fd = bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER, prog,
+					ARRAY_SIZE(prog), "GPL", 0,
+					log_buf, sizeof(log_buf));
+	if (prog_fd < 0)
+		error(1, errno, "failed to load prog\n%s\n", log_buf);
+}
+
+static void prog_attach_iptables(char *file)
+{
+	int ret;
+	char rules[100];
+
+	if (bpf_obj_pin(prog_fd, file))
+		error(1, errno, "bpf_obj_pin");
+	if (strlen(file) > 50) {
+		printf("file path too long: %s\n", file);
+		exit(1);
+	}
+	sprintf(rules, "iptables -A OUTPUT -m bpf --object-pinned %s -j ACCEPT",
+		file);
+	ret = system(rules);
+	if (ret < 0) {
+		printf("iptables rule update failed: %d/n", WEXITSTATUS(ret));
+		exit(1);
+	}
+}
+
+static void print_table(void)
+{
+	struct stats curEntry;
+	uint32_t curN = UINT32_MAX;
+	uint32_t nextN;
+	int res;
+
+	while (bpf_map_get_next_key(map_fd, &curN, &nextN) > -1) {
+		curN = nextN;
+		res = bpf_map_lookup_elem(map_fd, &curN, &curEntry);
+		if (res < 0) {
+			error(1, errno, "fail to get entry value of Key: %u\n",
+				curN);
+		} else {
+			printf("cookie: %u, uid: 0x%x, Packet Count: %lu,"
+				" Bytes Count: %lu\n", curN, curEntry.uid,
+				curEntry.packets, curEntry.bytes);
+		}
+	}
+}
+
+static void udp_client(void)
+{
+	struct sockaddr_in si_other = {0};
+	struct sockaddr_in si_me = {0};
+	struct stats dataEntry;
+	int s_rcv, s_send, i, recv_len;
+	char message = 'a';
+	char buf;
+	uint64_t cookie;
+	int res;
+	socklen_t cookie_len = sizeof(cookie);
+	socklen_t slen = sizeof(si_other);
+
+	s_rcv = socket(PF_INET, SOCK_DGRAM, 0);
+	if (s_rcv < 0)
+		error(1, errno, "rcv socket creat failed!\n");
+	si_other.sin_family = AF_INET;
+	si_other.sin_port = htons(PORT);
+	if (inet_aton("127.0.0.1", &si_other.sin_addr) == 0)
+		error(1, errno, "inet_aton\n");
+	if (bind(s_rcv, (struct sockaddr *)&si_other, sizeof(si_other)) == -1)
+		error(1, errno, "bind\n");
+	s_send = socket(PF_INET, SOCK_DGRAM, 0);
+	if (s_send < 0)
+		error(1, errno, "send socket creat failed!\n");
+	res = getsockopt(s_send, SOL_SOCKET, SO_COOKIE, &cookie, &cookie_len);
+	if (res < 0)
+		printf("get cookie failed: %s\n", strerror(errno));
+	res = bpf_map_lookup_elem(map_fd, &cookie, &dataEntry);
+	if (res != -1)
+		error(1, errno, "socket stat found while flow not active\n");
+	for (i = 0; i < 10; i++) {
+		res = sendto(s_send, &message, sizeof(message), 0,
+			     (struct sockaddr *)&si_other, slen);
+		if (res == -1)
+			error(1, errno, "send\n");
+		if (res != sizeof(message))
+			error(1, 0, "%uB != %luB\n", res, sizeof(message));
+		recv_len = recvfrom(s_rcv, &buf, sizeof(buf), 0,
+			     (struct sockaddr *)&si_me, &slen);
+		if (recv_len < 0)
+			error(1, errno, "receive\n");
+		res = memcmp(&(si_other.sin_addr), &(si_me.sin_addr),
+			   sizeof(si_me.sin_addr));
+		if (res != 0)
+			error(1, EFAULT, "sender addr error: %d\n", res);
+		printf("Message received: %c\n", buf);
+		res = bpf_map_lookup_elem(map_fd, &cookie, &dataEntry);
+		if (res < 0)
+			error(1, errno, "lookup sk stat failed, cookie: %lu\n",
+			      cookie);
+		printf("cookie: %lu, uid: 0x%x, Packet Count: %lu,"
+			" Bytes Count: %lu\n\n", cookie, dataEntry.uid,
+			dataEntry.packets, dataEntry.bytes);
+	}
+	close(s_send);
+	close(s_rcv);
+}
+
+static int usage(void)
+{
+	printf("Usage: ./run_cookie_uid_helper_example.sh"
+		" bpfObjName -option\n"
+		"	-t	traffic monitor test\n"
+		"	-s	getsockopt cookie test\n");
+	return 1;
+}
+
+static void finish(int ret)
+{
+	test_finish = true;
+}
+
+int main(int argc, char *argv[])
+{
+	int opt;
+	bool cfg_test_traffic = false;
+	bool cfg_test_cookie = false;
+
+	if (argc != 3)
+		return usage();
+	while ((opt = getopt(argc, argv, "ts")) != -1) {
+		switch (opt) {
+		case 't':
+			cfg_test_traffic = true;
+			break;
+		case 's':
+			cfg_test_cookie = true;
+			break;
+
+		default:
+			printf("unknown option %c\n", opt);
+			usage();
+			return -1;
+		}
+	}
+	maps_create();
+	prog_load();
+	prog_attach_iptables(argv[2]);
+	if (cfg_test_traffic) {
+		if (signal(SIGINT, finish) == SIG_ERR)
+			error(1, errno, "register SIGINT handler failed");
+		if (signal(SIGTERM, finish) == SIG_ERR)
+			error(1, errno, "register SIGTERM handler failed");
+		while (!test_finish) {
+			print_table();
+			printf("\n");
+			sleep(1);
+		};
+	} else if (cfg_test_cookie) {
+		udp_client();
+	}
+	close(prog_fd);
+	close(map_fd);
+	return 0;
+}
diff --git a/samples/bpf/cpustat_kern.c b/samples/bpf/cpustat_kern.c
new file mode 100644
index 000000000..5aefd19cd
--- /dev/null
+++ b/samples/bpf/cpustat_kern.c
@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/version.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+/*
+ * The CPU number, cstate number and pstate number are based
+ * on 96boards Hikey with octa CA53 CPUs.
+ *
+ * Every CPU have three idle states for cstate:
+ *   WFI, CPU_OFF, CLUSTER_OFF
+ *
+ * Every CPU have 5 operating points:
+ *   208MHz, 432MHz, 729MHz, 960MHz, 1200MHz
+ *
+ * This code is based on these assumption and other platforms
+ * need to adjust these definitions.
+ */
+#define MAX_CPU			8
+#define MAX_PSTATE_ENTRIES	5
+#define MAX_CSTATE_ENTRIES	3
+
+static int cpu_opps[] = { 208000, 432000, 729000, 960000, 1200000 };
+
+/*
+ * my_map structure is used to record cstate and pstate index and
+ * timestamp (Idx, Ts), when new event incoming we need to update
+ * combination for new state index and timestamp (Idx`, Ts`).
+ *
+ * Based on (Idx, Ts) and (Idx`, Ts`) we can calculate the time
+ * interval for the previous state: Duration(Idx) = Ts` - Ts.
+ *
+ * Every CPU has one below array for recording state index and
+ * timestamp, and record for cstate and pstate saperately:
+ *
+ * +--------------------------+
+ * | cstate timestamp         |
+ * +--------------------------+
+ * | cstate index             |
+ * +--------------------------+
+ * | pstate timestamp         |
+ * +--------------------------+
+ * | pstate index             |
+ * +--------------------------+
+ */
+#define MAP_OFF_CSTATE_TIME	0
+#define MAP_OFF_CSTATE_IDX	1
+#define MAP_OFF_PSTATE_TIME	2
+#define MAP_OFF_PSTATE_IDX	3
+#define MAP_OFF_NUM		4
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u64);
+	__uint(max_entries, MAX_CPU * MAP_OFF_NUM);
+} my_map SEC(".maps");
+
+/* cstate_duration records duration time for every idle state per CPU */
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u64);
+	__uint(max_entries, MAX_CPU * MAX_CSTATE_ENTRIES);
+} cstate_duration SEC(".maps");
+
+/* pstate_duration records duration time for every operating point per CPU */
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u64);
+	__uint(max_entries, MAX_CPU * MAX_PSTATE_ENTRIES);
+} pstate_duration SEC(".maps");
+
+/*
+ * The trace events for cpu_idle and cpu_frequency are taken from:
+ * /sys/kernel/debug/tracing/events/power/cpu_idle/format
+ * /sys/kernel/debug/tracing/events/power/cpu_frequency/format
+ *
+ * These two events have same format, so define one common structure.
+ */
+struct cpu_args {
+	u64 pad;
+	u32 state;
+	u32 cpu_id;
+};
+
+/* calculate pstate index, returns MAX_PSTATE_ENTRIES for failure */
+static u32 find_cpu_pstate_idx(u32 frequency)
+{
+	u32 i;
+
+	for (i = 0; i < sizeof(cpu_opps) / sizeof(u32); i++) {
+		if (frequency == cpu_opps[i])
+			return i;
+	}
+
+	return i;
+}
+
+SEC("tracepoint/power/cpu_idle")
+int bpf_prog1(struct cpu_args *ctx)
+{
+	u64 *cts, *pts, *cstate, *pstate, prev_state, cur_ts, delta;
+	u32 key, cpu, pstate_idx;
+	u64 *val;
+
+	if (ctx->cpu_id > MAX_CPU)
+		return 0;
+
+	cpu = ctx->cpu_id;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_CSTATE_TIME;
+	cts = bpf_map_lookup_elem(&my_map, &key);
+	if (!cts)
+		return 0;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_CSTATE_IDX;
+	cstate = bpf_map_lookup_elem(&my_map, &key);
+	if (!cstate)
+		return 0;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_PSTATE_TIME;
+	pts = bpf_map_lookup_elem(&my_map, &key);
+	if (!pts)
+		return 0;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_PSTATE_IDX;
+	pstate = bpf_map_lookup_elem(&my_map, &key);
+	if (!pstate)
+		return 0;
+
+	prev_state = *cstate;
+	*cstate = ctx->state;
+
+	if (!*cts) {
+		*cts = bpf_ktime_get_ns();
+		return 0;
+	}
+
+	cur_ts = bpf_ktime_get_ns();
+	delta = cur_ts - *cts;
+	*cts = cur_ts;
+
+	/*
+	 * When state doesn't equal to (u32)-1, the cpu will enter
+	 * one idle state; for this case we need to record interval
+	 * for the pstate.
+	 *
+	 *                 OPP2
+	 *            +---------------------+
+	 *     OPP1   |                     |
+	 *   ---------+                     |
+	 *                                  |  Idle state
+	 *                                  +---------------
+	 *
+	 *            |<- pstate duration ->|
+	 *            ^                     ^
+	 *           pts                  cur_ts
+	 */
+	if (ctx->state != (u32)-1) {
+
+		/* record pstate after have first cpu_frequency event */
+		if (!*pts)
+			return 0;
+
+		delta = cur_ts - *pts;
+
+		pstate_idx = find_cpu_pstate_idx(*pstate);
+		if (pstate_idx >= MAX_PSTATE_ENTRIES)
+			return 0;
+
+		key = cpu * MAX_PSTATE_ENTRIES + pstate_idx;
+		val = bpf_map_lookup_elem(&pstate_duration, &key);
+		if (val)
+			__sync_fetch_and_add((long *)val, delta);
+
+	/*
+	 * When state equal to (u32)-1, the cpu just exits from one
+	 * specific idle state; for this case we need to record
+	 * interval for the pstate.
+	 *
+	 *       OPP2
+	 *   -----------+
+	 *              |                          OPP1
+	 *              |                     +-----------
+	 *              |     Idle state      |
+	 *              +---------------------+
+	 *
+	 *              |<- cstate duration ->|
+	 *              ^                     ^
+	 *             cts                  cur_ts
+	 */
+	} else {
+
+		key = cpu * MAX_CSTATE_ENTRIES + prev_state;
+		val = bpf_map_lookup_elem(&cstate_duration, &key);
+		if (val)
+			__sync_fetch_and_add((long *)val, delta);
+	}
+
+	/* Update timestamp for pstate as new start time */
+	if (*pts)
+		*pts = cur_ts;
+
+	return 0;
+}
+
+SEC("tracepoint/power/cpu_frequency")
+int bpf_prog2(struct cpu_args *ctx)
+{
+	u64 *pts, *cstate, *pstate, prev_state, cur_ts, delta;
+	u32 key, cpu, pstate_idx;
+	u64 *val;
+
+	cpu = ctx->cpu_id;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_PSTATE_TIME;
+	pts = bpf_map_lookup_elem(&my_map, &key);
+	if (!pts)
+		return 0;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_PSTATE_IDX;
+	pstate = bpf_map_lookup_elem(&my_map, &key);
+	if (!pstate)
+		return 0;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_CSTATE_IDX;
+	cstate = bpf_map_lookup_elem(&my_map, &key);
+	if (!cstate)
+		return 0;
+
+	prev_state = *pstate;
+	*pstate = ctx->state;
+
+	if (!*pts) {
+		*pts = bpf_ktime_get_ns();
+		return 0;
+	}
+
+	cur_ts = bpf_ktime_get_ns();
+	delta = cur_ts - *pts;
+	*pts = cur_ts;
+
+	/* When CPU is in idle, bail out to skip pstate statistics */
+	if (*cstate != (u32)(-1))
+		return 0;
+
+	/*
+	 * The cpu changes to another different OPP (in below diagram
+	 * change frequency from OPP3 to OPP1), need recording interval
+	 * for previous frequency OPP3 and update timestamp as start
+	 * time for new frequency OPP1.
+	 *
+	 *                 OPP3
+	 *            +---------------------+
+	 *     OPP2   |                     |
+	 *   ---------+                     |
+	 *                                  |    OPP1
+	 *                                  +---------------
+	 *
+	 *            |<- pstate duration ->|
+	 *            ^                     ^
+	 *           pts                  cur_ts
+	 */
+	pstate_idx = find_cpu_pstate_idx(*pstate);
+	if (pstate_idx >= MAX_PSTATE_ENTRIES)
+		return 0;
+
+	key = cpu * MAX_PSTATE_ENTRIES + pstate_idx;
+	val = bpf_map_lookup_elem(&pstate_duration, &key);
+	if (val)
+		__sync_fetch_and_add((long *)val, delta);
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/cpustat_user.c b/samples/bpf/cpustat_user.c
new file mode 100644
index 000000000..96675985e
--- /dev/null
+++ b/samples/bpf/cpustat_user.c
@@ -0,0 +1,252 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sched.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <locale.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+static int cstate_map_fd, pstate_map_fd;
+
+#define MAX_CPU			8
+#define MAX_PSTATE_ENTRIES	5
+#define MAX_CSTATE_ENTRIES	3
+#define MAX_STARS		40
+
+#define CPUFREQ_MAX_SYSFS_PATH	"/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq"
+#define CPUFREQ_LOWEST_FREQ	"208000"
+#define CPUFREQ_HIGHEST_FREQ	"12000000"
+
+struct cpu_stat_data {
+	unsigned long cstate[MAX_CSTATE_ENTRIES];
+	unsigned long pstate[MAX_PSTATE_ENTRIES];
+};
+
+static struct cpu_stat_data stat_data[MAX_CPU];
+
+static void cpu_stat_print(void)
+{
+	int i, j;
+	char state_str[sizeof("cstate-9")];
+	struct cpu_stat_data *data;
+
+	/* Clear screen */
+	printf("\033[2J");
+
+	/* Header */
+	printf("\nCPU states statistics:\n");
+	printf("%-10s ", "state(ms)");
+
+	for (i = 0; i < MAX_CSTATE_ENTRIES; i++) {
+		sprintf(state_str, "cstate-%d", i);
+		printf("%-11s ", state_str);
+	}
+
+	for (i = 0; i < MAX_PSTATE_ENTRIES; i++) {
+		sprintf(state_str, "pstate-%d", i);
+		printf("%-11s ", state_str);
+	}
+
+	printf("\n");
+
+	for (j = 0; j < MAX_CPU; j++) {
+		data = &stat_data[j];
+
+		printf("CPU-%-6d ", j);
+		for (i = 0; i < MAX_CSTATE_ENTRIES; i++)
+			printf("%-11ld ", data->cstate[i] / 1000000);
+
+		for (i = 0; i < MAX_PSTATE_ENTRIES; i++)
+			printf("%-11ld ", data->pstate[i] / 1000000);
+
+		printf("\n");
+	}
+}
+
+static void cpu_stat_update(int cstate_fd, int pstate_fd)
+{
+	unsigned long key, value;
+	int c, i;
+
+	for (c = 0; c < MAX_CPU; c++) {
+		for (i = 0; i < MAX_CSTATE_ENTRIES; i++) {
+			key = c * MAX_CSTATE_ENTRIES + i;
+			bpf_map_lookup_elem(cstate_fd, &key, &value);
+			stat_data[c].cstate[i] = value;
+		}
+
+		for (i = 0; i < MAX_PSTATE_ENTRIES; i++) {
+			key = c * MAX_PSTATE_ENTRIES + i;
+			bpf_map_lookup_elem(pstate_fd, &key, &value);
+			stat_data[c].pstate[i] = value;
+		}
+	}
+}
+
+/*
+ * This function is copied from 'idlestat' tool function
+ * idlestat_wake_all() in idlestate.c.
+ *
+ * It sets the self running task affinity to cpus one by one so can wake up
+ * the specific CPU to handle scheduling; this results in all cpus can be
+ * waken up once and produce ftrace event 'trace_cpu_idle'.
+ */
+static int cpu_stat_inject_cpu_idle_event(void)
+{
+	int rcpu, i, ret;
+	cpu_set_t cpumask;
+	cpu_set_t original_cpumask;
+
+	ret = sysconf(_SC_NPROCESSORS_CONF);
+	if (ret < 0)
+		return -1;
+
+	rcpu = sched_getcpu();
+	if (rcpu < 0)
+		return -1;
+
+	/* Keep track of the CPUs we will run on */
+	sched_getaffinity(0, sizeof(original_cpumask), &original_cpumask);
+
+	for (i = 0; i < ret; i++) {
+
+		/* Pointless to wake up ourself */
+		if (i == rcpu)
+			continue;
+
+		/* Pointless to wake CPUs we will not run on */
+		if (!CPU_ISSET(i, &original_cpumask))
+			continue;
+
+		CPU_ZERO(&cpumask);
+		CPU_SET(i, &cpumask);
+
+		sched_setaffinity(0, sizeof(cpumask), &cpumask);
+	}
+
+	/* Enable all the CPUs of the original mask */
+	sched_setaffinity(0, sizeof(original_cpumask), &original_cpumask);
+	return 0;
+}
+
+/*
+ * It's possible to have no any frequency change for long time and cannot
+ * get ftrace event 'trace_cpu_frequency' for long period, this introduces
+ * big deviation for pstate statistics.
+ *
+ * To solve this issue, below code forces to set 'scaling_max_freq' to 208MHz
+ * for triggering ftrace event 'trace_cpu_frequency' and then recovery back to
+ * the maximum frequency value 1.2GHz.
+ */
+static int cpu_stat_inject_cpu_frequency_event(void)
+{
+	int len, fd;
+
+	fd = open(CPUFREQ_MAX_SYSFS_PATH, O_WRONLY);
+	if (fd < 0) {
+		printf("failed to open scaling_max_freq, errno=%d\n", errno);
+		return fd;
+	}
+
+	len = write(fd, CPUFREQ_LOWEST_FREQ, strlen(CPUFREQ_LOWEST_FREQ));
+	if (len < 0) {
+		printf("failed to open scaling_max_freq, errno=%d\n", errno);
+		goto err;
+	}
+
+	len = write(fd, CPUFREQ_HIGHEST_FREQ, strlen(CPUFREQ_HIGHEST_FREQ));
+	if (len < 0) {
+		printf("failed to open scaling_max_freq, errno=%d\n", errno);
+		goto err;
+	}
+
+err:
+	close(fd);
+	return len;
+}
+
+static void int_exit(int sig)
+{
+	cpu_stat_inject_cpu_idle_event();
+	cpu_stat_inject_cpu_frequency_event();
+	cpu_stat_update(cstate_map_fd, pstate_map_fd);
+	cpu_stat_print();
+	exit(0);
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	int ret;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (!prog) {
+		printf("finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	cstate_map_fd = bpf_object__find_map_fd_by_name(obj, "cstate_duration");
+	pstate_map_fd = bpf_object__find_map_fd_by_name(obj, "pstate_duration");
+	if (cstate_map_fd < 0 || pstate_map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	ret = cpu_stat_inject_cpu_idle_event();
+	if (ret < 0)
+		return 1;
+
+	ret = cpu_stat_inject_cpu_frequency_event();
+	if (ret < 0)
+		return 1;
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	while (1) {
+		cpu_stat_update(cstate_map_fd, pstate_map_fd);
+		cpu_stat_print();
+		sleep(5);
+	}
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/do_hbm_test.sh b/samples/bpf/do_hbm_test.sh
new file mode 100755
index 000000000..ffe4c0607
--- /dev/null
+++ b/samples/bpf/do_hbm_test.sh
@@ -0,0 +1,442 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2019 Facebook
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of version 2 of the GNU General Public
+# License as published by the Free Software Foundation.
+
+Usage() {
+  echo "Script for testing HBM (Host Bandwidth Manager) framework."
+  echo "It creates a cgroup to use for testing and load a BPF program to limit"
+  echo "egress or ingress bandwidht. It then uses iperf3 or netperf to create"
+  echo "loads. The output is the goodput in Mbps (unless -D was used)."
+  echo ""
+  echo "USAGE: $name [out] [-b=<prog>|--bpf=<prog>] [-c=<cc>|--cc=<cc>]"
+  echo "             [-D] [-d=<delay>|--delay=<delay>] [--debug] [-E] [--edt]"
+  echo "             [-f=<#flows>|--flows=<#flows>] [-h] [-i=<id>|--id=<id >]"
+  echo "             [-l] [-N] [--no_cn] [-p=<port>|--port=<port>] [-P]"
+  echo "             [-q=<qdisc>] [-R] [-s=<server>|--server=<server]"
+  echo "             [-S|--stats] -t=<time>|--time=<time>] [-w] [cubic|dctcp]"
+  echo "  Where:"
+  echo "    out               egress (default)"
+  echo "    -b or --bpf       BPF program filename to load and attach."
+  echo "                      Default is hbm_out_kern.o for egress,"
+  echo "    -c or -cc         TCP congestion control (cubic or dctcp)"
+  echo "    --debug           print BPF trace buffer"
+  echo "    -d or --delay     add a delay in ms using netem"
+  echo "    -D                In addition to the goodput in Mbps, it also outputs"
+  echo "                      other detailed information. This information is"
+  echo "                      test dependent (i.e. iperf3 or netperf)."
+  echo "    -E                enable ECN (not required for dctcp)"
+  echo "    --edt             use fq's Earliest Departure Time (requires fq)"
+  echo "    -f or --flows     number of concurrent flows (default=1)"
+  echo "    -i or --id        cgroup id (an integer, default is 1)"
+  echo "    -N                use netperf instead of iperf3"
+  echo "    --no_cn           Do not return CN notifications"
+  echo "    -l                do not limit flows using loopback"
+  echo "    -h                Help"
+  echo "    -p or --port      iperf3 port (default is 5201)"
+  echo "    -P                use an iperf3 instance for each flow"
+  echo "    -q                use the specified qdisc"
+  echo "    -r or --rate      rate in Mbps (default 1s 1Gbps)"
+  echo "    -R                Use TCP_RR for netperf. 1st flow has req"
+  echo "                      size of 10KB, rest of 1MB. Reply in all"
+  echo "                      cases is 1 byte."
+  echo "                      More detailed output for each flow can be found"
+  echo "                      in the files netperf.<cg>.<flow>, where <cg> is the"
+  echo "                      cgroup id as specified with the -i flag, and <flow>"
+  echo "                      is the flow id starting at 1 and increasing by 1 for"
+  echo "                      flow (as specified by -f)."
+  echo "    -s or --server    hostname of netperf server. Used to create netperf"
+  echo "                      test traffic between to hosts (default is within host)"
+  echo "                      netserver must be running on the host."
+  echo "    -S or --stats     whether to update hbm stats (default is yes)."
+  echo "    -t or --time      duration of iperf3 in seconds (default=5)"
+  echo "    -w                Work conserving flag. cgroup can increase its"
+  echo "                      bandwidth beyond the rate limit specified"
+  echo "                      while there is available bandwidth. Current"
+  echo "                      implementation assumes there is only one NIC"
+  echo "                      (eth0), but can be extended to support multiple"
+  echo "                       NICs."
+  echo "    cubic or dctcp    specify which TCP CC to use"
+  echo " "
+  exit
+}
+
+#set -x
+
+debug_flag=0
+args="$@"
+name="$0"
+netem=0
+cc=x
+dir="-o"
+dir_name="out"
+dur=5
+flows=1
+id=1
+prog=""
+port=5201
+rate=1000
+multi_iperf=0
+flow_cnt=1
+use_netperf=0
+rr=0
+ecn=0
+details=0
+server=""
+qdisc=""
+flags=""
+do_stats=0
+
+function start_hbm () {
+  rm -f hbm.out
+  echo "./hbm $dir -n $id -r $rate -t $dur $flags $dbg $prog" > hbm.out
+  echo " " >> hbm.out
+  ./hbm $dir -n $id -r $rate -t $dur $flags $dbg $prog >> hbm.out 2>&1  &
+  echo $!
+}
+
+processArgs () {
+  for i in $args ; do
+    case $i in
+    # Support for upcomming ingress rate limiting
+    #in)         # support for upcoming ingress rate limiting
+    #  dir="-i"
+    #  dir_name="in"
+    #  ;;
+    out)
+      dir="-o"
+      dir_name="out"
+      ;;
+    -b=*|--bpf=*)
+      prog="${i#*=}"
+      ;;
+    -c=*|--cc=*)
+      cc="${i#*=}"
+      ;;
+    --no_cn)
+      flags="$flags --no_cn"
+      ;;
+    --debug)
+      flags="$flags -d"
+      debug_flag=1
+      ;;
+    -d=*|--delay=*)
+      netem="${i#*=}"
+      ;;
+    -D)
+      details=1
+      ;;
+    -E)
+      ecn=1
+      ;;
+    --edt)
+      flags="$flags --edt"
+      qdisc="fq"
+     ;;
+    -f=*|--flows=*)
+      flows="${i#*=}"
+      ;;
+    -i=*|--id=*)
+      id="${i#*=}"
+      ;;
+    -l)
+      flags="$flags -l"
+      ;;
+    -N)
+      use_netperf=1
+      ;;
+    -p=*|--port=*)
+      port="${i#*=}"
+      ;;
+    -P)
+      multi_iperf=1
+      ;;
+    -q=*)
+      qdisc="${i#*=}"
+      ;;
+    -r=*|--rate=*)
+      rate="${i#*=}"
+      ;;
+    -R)
+      rr=1
+      ;;
+    -s=*|--server=*)
+      server="${i#*=}"
+      ;;
+    -S|--stats)
+      flags="$flags -s"
+      do_stats=1
+      ;;
+    -t=*|--time=*)
+      dur="${i#*=}"
+      ;;
+    -w)
+      flags="$flags -w"
+      ;;
+    cubic)
+      cc=cubic
+      ;;
+    dctcp)
+      cc=dctcp
+      ;;
+    *)
+      echo "Unknown arg:$i"
+      Usage
+      ;;
+    esac
+  done
+}
+
+processArgs
+
+if [ $debug_flag -eq 1 ] ; then
+  rm -f hbm_out.log
+fi
+
+hbm_pid=$(start_hbm)
+usleep 100000
+
+host=`hostname`
+cg_base_dir=/sys/fs/cgroup
+cg_dir="$cg_base_dir/cgroup-test-work-dir/hbm$id"
+
+echo $$ >> $cg_dir/cgroup.procs
+
+ulimit -l unlimited
+
+rm -f ss.out
+rm -f hbm.[0-9]*.$dir_name
+if [ $ecn -ne 0 ] ; then
+  sysctl -w -q -n net.ipv4.tcp_ecn=1
+fi
+
+if [ $use_netperf -eq 0 ] ; then
+  cur_cc=`sysctl -n net.ipv4.tcp_congestion_control`
+  if [ "$cc" != "x" ] ; then
+    sysctl -w -q -n net.ipv4.tcp_congestion_control=$cc
+  fi
+fi
+
+if [ "$netem" -ne "0" ] ; then
+  if [ "$qdisc" != "" ] ; then
+    echo "WARNING: Ignoring -q options because -d option used"
+  fi
+  tc qdisc del dev lo root > /dev/null 2>&1
+  tc qdisc add dev lo root netem delay $netem\ms > /dev/null 2>&1
+elif [ "$qdisc" != "" ] ; then
+  tc qdisc del dev eth0 root > /dev/null 2>&1
+  tc qdisc add dev eth0 root $qdisc > /dev/null 2>&1
+fi
+
+n=0
+m=$[$dur * 5]
+hn="::1"
+if [ $use_netperf -ne 0 ] ; then
+  if [ "$server" != "" ] ; then
+    hn=$server
+  fi
+fi
+
+( ping6 -i 0.2 -c $m $hn > ping.out 2>&1 ) &
+
+if [ $use_netperf -ne 0 ] ; then
+  begNetserverPid=`ps ax | grep netserver | grep --invert-match "grep" | \
+                   awk '{ print $1 }'`
+  if [ "$begNetserverPid" == "" ] ; then
+    if [ "$server" == "" ] ; then
+      ( ./netserver > /dev/null 2>&1) &
+      usleep 100000
+    fi
+  fi
+  flow_cnt=1
+  if [ "$server" == "" ] ; then
+    np_server=$host
+  else
+    np_server=$server
+  fi
+  if [ "$cc" == "x" ] ; then
+    np_cc=""
+  else
+    np_cc="-K $cc,$cc"
+  fi
+  replySize=1
+  while [ $flow_cnt -le $flows ] ; do
+    if [ $rr -ne 0 ] ; then
+      reqSize=1M
+      if [ $flow_cnt -eq 1 ] ; then
+        reqSize=10K
+      fi
+      if [ "$dir" == "-i" ] ; then
+        replySize=$reqSize
+        reqSize=1
+      fi
+      ( ./netperf -H $np_server -l $dur -f m -j -t TCP_RR  -- -r $reqSize,$replySize $np_cc -k P50_lATENCY,P90_LATENCY,LOCAL_TRANSPORT_RETRANS,REMOTE_TRANSPORT_RETRANS,LOCAL_SEND_THROUGHPUT,LOCAL_RECV_THROUGHPUT,REQUEST_SIZE,RESPONSE_SIZE > netperf.$id.$flow_cnt ) &
+    else
+      if [ "$dir" == "-i" ] ; then
+        ( ./netperf -H $np_server -l $dur -f m -j -t TCP_RR -- -r 1,10M $np_cc -k P50_LATENCY,P90_LATENCY,LOCAL_TRANSPORT_RETRANS,LOCAL_SEND_THROUGHPUT,REMOTE_TRANSPORT_RETRANS,REMOTE_SEND_THROUGHPUT,REQUEST_SIZE,RESPONSE_SIZE > netperf.$id.$flow_cnt ) &
+      else
+        ( ./netperf -H $np_server -l $dur -f m -j -t TCP_STREAM -- $np_cc -k P50_lATENCY,P90_LATENCY,LOCAL_TRANSPORT_RETRANS,LOCAL_SEND_THROUGHPUT,REQUEST_SIZE,RESPONSE_SIZE > netperf.$id.$flow_cnt ) &
+      fi
+    fi
+    flow_cnt=$[flow_cnt+1]
+  done
+
+# sleep for duration of test (plus some buffer)
+  n=$[dur+2]
+  sleep $n
+
+# force graceful termination of netperf
+  pids=`pgrep netperf`
+  for p in $pids ; do
+    kill -SIGALRM $p
+  done
+
+  flow_cnt=1
+  rate=0
+  if [ $details -ne 0 ] ; then
+    echo ""
+    echo "Details for HBM in cgroup $id"
+    if [ $do_stats -eq 1 ] ; then
+      if [ -e hbm.$id.$dir_name ] ; then
+        cat hbm.$id.$dir_name
+      fi
+    fi
+  fi
+  while [ $flow_cnt -le $flows ] ; do
+    if [ "$dir" == "-i" ] ; then
+      r=`cat netperf.$id.$flow_cnt | grep -o "REMOTE_SEND_THROUGHPUT=[0-9]*" | grep -o "[0-9]*"`
+    else
+      r=`cat netperf.$id.$flow_cnt | grep -o "LOCAL_SEND_THROUGHPUT=[0-9]*" | grep -o "[0-9]*"`
+    fi
+    echo "rate for flow $flow_cnt: $r"
+    rate=$[rate+r]
+    if [ $details -ne 0 ] ; then
+      echo "-----"
+      echo "Details for cgroup $id, flow $flow_cnt"
+      cat netperf.$id.$flow_cnt
+    fi
+    flow_cnt=$[flow_cnt+1]
+  done
+  if [ $details -ne 0 ] ; then
+    echo ""
+    delay=`grep "avg" ping.out | grep -o "= [0-9.]*/[0-9.]*" | grep -o "[0-9.]*$"`
+    echo "PING AVG DELAY:$delay"
+    echo "AGGREGATE_GOODPUT:$rate"
+  else
+    echo $rate
+  fi
+elif [ $multi_iperf -eq 0 ] ; then
+  (iperf3 -s -p $port -1 > /dev/null 2>&1) &
+  usleep 100000
+  iperf3 -c $host -p $port -i 0 -P $flows -f m -t $dur > iperf.$id
+  rates=`grep receiver iperf.$id | grep -o "[0-9.]* Mbits" | grep -o "^[0-9]*"`
+  rate=`echo $rates | grep -o "[0-9]*$"`
+
+  if [ $details -ne 0 ] ; then
+    echo ""
+    echo "Details for HBM in cgroup $id"
+    if [ $do_stats -eq 1 ] ; then
+      if [ -e hbm.$id.$dir_name ] ; then
+        cat hbm.$id.$dir_name
+      fi
+    fi
+    delay=`grep "avg" ping.out | grep -o "= [0-9.]*/[0-9.]*" | grep -o "[0-9.]*$"`
+    echo "PING AVG DELAY:$delay"
+    echo "AGGREGATE_GOODPUT:$rate"
+  else
+    echo $rate
+  fi
+else
+  flow_cnt=1
+  while [ $flow_cnt -le $flows ] ; do
+    (iperf3 -s -p $port -1 > /dev/null 2>&1) &
+    ( iperf3 -c $host -p $port -i 0 -P 1 -f m -t $dur | grep receiver | grep -o "[0-9.]* Mbits" | grep -o "^[0-9]*" | grep -o "[0-9]*$" > iperf3.$id.$flow_cnt ) &
+    port=$[port+1]
+    flow_cnt=$[flow_cnt+1]
+  done
+  n=$[dur+1]
+  sleep $n
+  flow_cnt=1
+  rate=0
+  if [ $details -ne 0 ] ; then
+    echo ""
+    echo "Details for HBM in cgroup $id"
+    if [ $do_stats -eq 1 ] ; then
+      if [ -e hbm.$id.$dir_name ] ; then
+        cat hbm.$id.$dir_name
+      fi
+    fi
+  fi
+
+  while [ $flow_cnt -le $flows ] ; do
+    r=`cat iperf3.$id.$flow_cnt`
+#    echo "rate for flow $flow_cnt: $r"
+  if [ $details -ne 0 ] ; then
+    echo "Rate for cgroup $id, flow $flow_cnt LOCAL_SEND_THROUGHPUT=$r"
+  fi
+    rate=$[rate+r]
+    flow_cnt=$[flow_cnt+1]
+  done
+  if [ $details -ne 0 ] ; then
+    delay=`grep "avg" ping.out | grep -o "= [0-9.]*/[0-9.]*" | grep -o "[0-9.]*$"`
+    echo "PING AVG DELAY:$delay"
+    echo "AGGREGATE_GOODPUT:$rate"
+  else
+    echo $rate
+  fi
+fi
+
+if [ $use_netperf -eq 0 ] ; then
+  sysctl -w -q -n net.ipv4.tcp_congestion_control=$cur_cc
+fi
+if [ $ecn -ne 0 ] ; then
+  sysctl -w -q -n net.ipv4.tcp_ecn=0
+fi
+if [ "$netem" -ne "0" ] ; then
+  tc qdisc del dev lo root > /dev/null 2>&1
+fi
+if [ "$qdisc" != "" ] ; then
+  tc qdisc del dev eth0 root > /dev/null 2>&1
+fi
+sleep 2
+
+hbmPid=`ps ax | grep "hbm " | grep --invert-match "grep" | awk '{ print $1 }'`
+if [ "$hbmPid" == "$hbm_pid" ] ; then
+  kill $hbm_pid
+fi
+
+sleep 1
+
+# Detach any BPF programs that may have lingered
+ttx=`bpftool cgroup tree | grep hbm`
+v=2
+for x in $ttx ; do
+    if [ "${x:0:36}" == "/sys/fs/cgroup/cgroup-test-work-dir/" ] ; then
+	cg=$x ; v=0
+    else
+	if [ $v -eq 0 ] ; then
+	    id=$x ; v=1
+	else
+	    if [ $v -eq 1 ] ; then
+		type=$x ; bpftool cgroup detach $cg $type id $id
+		v=0
+	    fi
+	fi
+    fi
+done
+
+if [ $use_netperf -ne 0 ] ; then
+  if [ "$server" == "" ] ; then
+    if [ "$begNetserverPid" == "" ] ; then
+      netserverPid=`ps ax | grep netserver | grep --invert-match "grep" | awk '{ print $1 }'`
+      if [ "$netserverPid" != "" ] ; then
+        kill $netserverPid
+      fi
+    fi
+  fi
+fi
+exit
diff --git a/samples/bpf/fds_example.c b/samples/bpf/fds_example.c
new file mode 100644
index 000000000..59f45fef5
--- /dev/null
+++ b/samples/bpf/fds_example.c
@@ -0,0 +1,193 @@
+#include <linux/unistd.h>
+#include <linux/bpf.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <bpf/bpf.h>
+
+#include <bpf/libbpf.h>
+#include "bpf_insn.h"
+#include "sock_example.h"
+
+#define BPF_F_PIN	(1 << 0)
+#define BPF_F_GET	(1 << 1)
+#define BPF_F_PIN_GET	(BPF_F_PIN | BPF_F_GET)
+
+#define BPF_F_KEY	(1 << 2)
+#define BPF_F_VAL	(1 << 3)
+#define BPF_F_KEY_VAL	(BPF_F_KEY | BPF_F_VAL)
+
+#define BPF_M_UNSPEC	0
+#define BPF_M_MAP	1
+#define BPF_M_PROG	2
+
+char bpf_log_buf[BPF_LOG_BUF_SIZE];
+
+static void usage(void)
+{
+	printf("Usage: fds_example [...]\n");
+	printf("       -F <file>   File to pin/get object\n");
+	printf("       -P          |- pin object\n");
+	printf("       -G          `- get object\n");
+	printf("       -m          eBPF map mode\n");
+	printf("       -k <key>    |- map key\n");
+	printf("       -v <value>  `- map value\n");
+	printf("       -p          eBPF prog mode\n");
+	printf("       -o <object> `- object file\n");
+	printf("       -h          Display this help.\n");
+}
+
+static int bpf_map_create(void)
+{
+	return bpf_create_map(BPF_MAP_TYPE_ARRAY, sizeof(uint32_t),
+			      sizeof(uint32_t), 1024, 0);
+}
+
+static int bpf_prog_create(const char *object)
+{
+	static struct bpf_insn insns[] = {
+		BPF_MOV64_IMM(BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+	};
+	size_t insns_cnt = sizeof(insns) / sizeof(struct bpf_insn);
+	struct bpf_object *obj;
+	int prog_fd;
+
+	if (object) {
+		assert(!bpf_prog_load(object, BPF_PROG_TYPE_UNSPEC,
+				      &obj, &prog_fd));
+		return prog_fd;
+	} else {
+		return bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER,
+					insns, insns_cnt, "GPL", 0,
+					bpf_log_buf, BPF_LOG_BUF_SIZE);
+	}
+}
+
+static int bpf_do_map(const char *file, uint32_t flags, uint32_t key,
+		      uint32_t value)
+{
+	int fd, ret;
+
+	if (flags & BPF_F_PIN) {
+		fd = bpf_map_create();
+		printf("bpf: map fd:%d (%s)\n", fd, strerror(errno));
+		assert(fd > 0);
+
+		ret = bpf_obj_pin(fd, file);
+		printf("bpf: pin ret:(%d,%s)\n", ret, strerror(errno));
+		assert(ret == 0);
+	} else {
+		fd = bpf_obj_get(file);
+		printf("bpf: get fd:%d (%s)\n", fd, strerror(errno));
+		assert(fd > 0);
+	}
+
+	if ((flags & BPF_F_KEY_VAL) == BPF_F_KEY_VAL) {
+		ret = bpf_map_update_elem(fd, &key, &value, 0);
+		printf("bpf: fd:%d u->(%u:%u) ret:(%d,%s)\n", fd, key, value,
+		       ret, strerror(errno));
+		assert(ret == 0);
+	} else if (flags & BPF_F_KEY) {
+		ret = bpf_map_lookup_elem(fd, &key, &value);
+		printf("bpf: fd:%d l->(%u):%u ret:(%d,%s)\n", fd, key, value,
+		       ret, strerror(errno));
+		assert(ret == 0);
+	}
+
+	return 0;
+}
+
+static int bpf_do_prog(const char *file, uint32_t flags, const char *object)
+{
+	int fd, sock, ret;
+
+	if (flags & BPF_F_PIN) {
+		fd = bpf_prog_create(object);
+		printf("bpf: prog fd:%d (%s)\n", fd, strerror(errno));
+		assert(fd > 0);
+
+		ret = bpf_obj_pin(fd, file);
+		printf("bpf: pin ret:(%d,%s)\n", ret, strerror(errno));
+		assert(ret == 0);
+	} else {
+		fd = bpf_obj_get(file);
+		printf("bpf: get fd:%d (%s)\n", fd, strerror(errno));
+		assert(fd > 0);
+	}
+
+	sock = open_raw_sock("lo");
+	assert(sock > 0);
+
+	ret = setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &fd, sizeof(fd));
+	printf("bpf: sock:%d <- fd:%d attached ret:(%d,%s)\n", sock, fd,
+	       ret, strerror(errno));
+	assert(ret == 0);
+
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	const char *file = NULL, *object = NULL;
+	uint32_t key = 0, value = 0, flags = 0;
+	int opt, mode = BPF_M_UNSPEC;
+
+	while ((opt = getopt(argc, argv, "F:PGmk:v:po:")) != -1) {
+		switch (opt) {
+		/* General args */
+		case 'F':
+			file = optarg;
+			break;
+		case 'P':
+			flags |= BPF_F_PIN;
+			break;
+		case 'G':
+			flags |= BPF_F_GET;
+			break;
+		/* Map-related args */
+		case 'm':
+			mode = BPF_M_MAP;
+			break;
+		case 'k':
+			key = strtoul(optarg, NULL, 0);
+			flags |= BPF_F_KEY;
+			break;
+		case 'v':
+			value = strtoul(optarg, NULL, 0);
+			flags |= BPF_F_VAL;
+			break;
+		/* Prog-related args */
+		case 'p':
+			mode = BPF_M_PROG;
+			break;
+		case 'o':
+			object = optarg;
+			break;
+		default:
+			goto out;
+		}
+	}
+
+	if (!(flags & BPF_F_PIN_GET) || !file)
+		goto out;
+
+	switch (mode) {
+	case BPF_M_MAP:
+		return bpf_do_map(file, flags, key, value);
+	case BPF_M_PROG:
+		return bpf_do_prog(file, flags, object);
+	}
+out:
+	usage();
+	return -1;
+}
diff --git a/samples/bpf/hash_func01.h b/samples/bpf/hash_func01.h
new file mode 100644
index 000000000..38255812e
--- /dev/null
+++ b/samples/bpf/hash_func01.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: LGPL-2.1
+ *
+ * Based on Paul Hsieh's (LGPG 2.1) hash function
+ * From: http://www.azillionmonkeys.com/qed/hash.html
+ */
+
+#define get16bits(d) (*((const __u16 *) (d)))
+
+static __always_inline
+__u32 SuperFastHash (const char *data, int len, __u32 initval) {
+	__u32 hash = initval;
+	__u32 tmp;
+	int rem;
+
+	if (len <= 0 || data == NULL) return 0;
+
+	rem = len & 3;
+	len >>= 2;
+
+	/* Main loop */
+#pragma clang loop unroll(full)
+	for (;len > 0; len--) {
+		hash  += get16bits (data);
+		tmp    = (get16bits (data+2) << 11) ^ hash;
+		hash   = (hash << 16) ^ tmp;
+		data  += 2*sizeof (__u16);
+		hash  += hash >> 11;
+	}
+
+	/* Handle end cases */
+	switch (rem) {
+        case 3: hash += get16bits (data);
+                hash ^= hash << 16;
+                hash ^= ((signed char)data[sizeof (__u16)]) << 18;
+                hash += hash >> 11;
+                break;
+        case 2: hash += get16bits (data);
+                hash ^= hash << 11;
+                hash += hash >> 17;
+                break;
+        case 1: hash += (signed char)*data;
+                hash ^= hash << 10;
+                hash += hash >> 1;
+	}
+
+	/* Force "avalanching" of final 127 bits */
+	hash ^= hash << 3;
+	hash += hash >> 5;
+	hash ^= hash << 4;
+	hash += hash >> 17;
+	hash ^= hash << 25;
+	hash += hash >> 6;
+
+	return hash;
+}
diff --git a/samples/bpf/hbm.c b/samples/bpf/hbm.c
new file mode 100644
index 000000000..8e48489b9
--- /dev/null
+++ b/samples/bpf/hbm.c
@@ -0,0 +1,500 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Example program for Host Bandwidth Managment
+ *
+ * This program loads a cgroup skb BPF program to enforce cgroup output
+ * (egress) or input (ingress) bandwidth limits.
+ *
+ * USAGE: hbm [-d] [-l] [-n <id>] [-r <rate>] [-s] [-t <secs>] [-w] [-h] [prog]
+ *   Where:
+ *    -d	Print BPF trace debug buffer
+ *    -l	Also limit flows doing loopback
+ *    -n <#>	To create cgroup \"/hbm#\" and attach prog
+ *		Default is /hbm1
+ *    --no_cn   Do not return cn notifications
+ *    -r <rate>	Rate limit in Mbps
+ *    -s	Get HBM stats (marked, dropped, etc.)
+ *    -t <time>	Exit after specified seconds (default is 0)
+ *    -w	Work conserving flag. cgroup can increase its bandwidth
+ *		beyond the rate limit specified while there is available
+ *		bandwidth. Current implementation assumes there is only
+ *		NIC (eth0), but can be extended to support multiple NICs.
+ *		Currrently only supported for egress.
+ *    -h	Print this info
+ *    prog	BPF program file name. Name defaults to hbm_out_kern.o
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <sys/resource.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/unistd.h>
+#include <linux/compiler.h>
+
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+#include <getopt.h>
+
+#include "bpf_load.h"
+#include "bpf_rlimit.h"
+#include "cgroup_helpers.h"
+#include "hbm.h"
+#include "bpf_util.h"
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+bool outFlag = true;
+int minRate = 1000;		/* cgroup rate limit in Mbps */
+int rate = 1000;		/* can grow if rate conserving is enabled */
+int dur = 1;
+bool stats_flag;
+bool loopback_flag;
+bool debugFlag;
+bool work_conserving_flag;
+bool no_cn_flag;
+bool edt_flag;
+
+static void Usage(void);
+static void read_trace_pipe2(void);
+static void do_error(char *msg, bool errno_flag);
+
+#define DEBUGFS "/sys/kernel/debug/tracing/"
+
+struct bpf_object *obj;
+int bpfprog_fd;
+int cgroup_storage_fd;
+
+static void read_trace_pipe2(void)
+{
+	int trace_fd;
+	FILE *outf;
+	char *outFname = "hbm_out.log";
+
+	trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0);
+	if (trace_fd < 0) {
+		printf("Error opening trace_pipe\n");
+		return;
+	}
+
+//	Future support of ingress
+//	if (!outFlag)
+//		outFname = "hbm_in.log";
+	outf = fopen(outFname, "w");
+
+	if (outf == NULL)
+		printf("Error creating %s\n", outFname);
+
+	while (1) {
+		static char buf[4097];
+		ssize_t sz;
+
+		sz = read(trace_fd, buf, sizeof(buf) - 1);
+		if (sz > 0) {
+			buf[sz] = 0;
+			puts(buf);
+			if (outf != NULL) {
+				fprintf(outf, "%s\n", buf);
+				fflush(outf);
+			}
+		}
+	}
+}
+
+static void do_error(char *msg, bool errno_flag)
+{
+	if (errno_flag)
+		printf("ERROR: %s, errno: %d\n", msg, errno);
+	else
+		printf("ERROR: %s\n", msg);
+	exit(1);
+}
+
+static int prog_load(char *prog)
+{
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+		.file = prog,
+		.expected_attach_type = BPF_CGROUP_INET_EGRESS,
+	};
+	int map_fd;
+	struct bpf_map *map;
+
+	int ret = 0;
+
+	if (access(prog, O_RDONLY) < 0) {
+		printf("Error accessing file %s: %s\n", prog, strerror(errno));
+		return 1;
+	}
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &bpfprog_fd))
+		ret = 1;
+	if (!ret) {
+		map = bpf_object__find_map_by_name(obj, "queue_stats");
+		map_fd = bpf_map__fd(map);
+		if (map_fd < 0) {
+			printf("Map not found: %s\n", strerror(map_fd));
+			ret = 1;
+		}
+	}
+
+	if (ret) {
+		printf("ERROR: bpf_prog_load_xattr failed for: %s\n", prog);
+		printf("  Output from verifier:\n%s\n------\n", bpf_log_buf);
+		ret = -1;
+	} else {
+		ret = map_fd;
+	}
+
+	return ret;
+}
+
+static int run_bpf_prog(char *prog, int cg_id)
+{
+	int map_fd;
+	int rc = 0;
+	int key = 0;
+	int cg1 = 0;
+	int type = BPF_CGROUP_INET_EGRESS;
+	char cg_dir[100];
+	struct hbm_queue_stats qstats = {0};
+
+	sprintf(cg_dir, "/hbm%d", cg_id);
+	map_fd = prog_load(prog);
+	if (map_fd  == -1)
+		return 1;
+
+	if (setup_cgroup_environment()) {
+		printf("ERROR: setting cgroup environment\n");
+		goto err;
+	}
+	cg1 = create_and_get_cgroup(cg_dir);
+	if (!cg1) {
+		printf("ERROR: create_and_get_cgroup\n");
+		goto err;
+	}
+	if (join_cgroup(cg_dir)) {
+		printf("ERROR: join_cgroup\n");
+		goto err;
+	}
+
+	qstats.rate = rate;
+	qstats.stats = stats_flag ? 1 : 0;
+	qstats.loopback = loopback_flag ? 1 : 0;
+	qstats.no_cn = no_cn_flag ? 1 : 0;
+	if (bpf_map_update_elem(map_fd, &key, &qstats, BPF_ANY)) {
+		printf("ERROR: Could not update map element\n");
+		goto err;
+	}
+
+	if (!outFlag)
+		type = BPF_CGROUP_INET_INGRESS;
+	if (bpf_prog_attach(bpfprog_fd, cg1, type, 0)) {
+		printf("ERROR: bpf_prog_attach fails!\n");
+		log_err("Attaching prog");
+		goto err;
+	}
+
+	if (work_conserving_flag) {
+		struct timeval t0, t_last, t_new;
+		FILE *fin;
+		unsigned long long last_eth_tx_bytes, new_eth_tx_bytes;
+		signed long long last_cg_tx_bytes, new_cg_tx_bytes;
+		signed long long delta_time, delta_bytes, delta_rate;
+		int delta_ms;
+#define DELTA_RATE_CHECK 10000		/* in us */
+#define RATE_THRESHOLD 9500000000	/* 9.5 Gbps */
+
+		bpf_map_lookup_elem(map_fd, &key, &qstats);
+		if (gettimeofday(&t0, NULL) < 0)
+			do_error("gettimeofday failed", true);
+		t_last = t0;
+		fin = fopen("/sys/class/net/eth0/statistics/tx_bytes", "r");
+		if (fscanf(fin, "%llu", &last_eth_tx_bytes) != 1)
+			do_error("fscanf fails", false);
+		fclose(fin);
+		last_cg_tx_bytes = qstats.bytes_total;
+		while (true) {
+			usleep(DELTA_RATE_CHECK);
+			if (gettimeofday(&t_new, NULL) < 0)
+				do_error("gettimeofday failed", true);
+			delta_ms = (t_new.tv_sec - t0.tv_sec) * 1000 +
+				(t_new.tv_usec - t0.tv_usec)/1000;
+			if (delta_ms > dur * 1000)
+				break;
+			delta_time = (t_new.tv_sec - t_last.tv_sec) * 1000000 +
+				(t_new.tv_usec - t_last.tv_usec);
+			if (delta_time == 0)
+				continue;
+			t_last = t_new;
+			fin = fopen("/sys/class/net/eth0/statistics/tx_bytes",
+				    "r");
+			if (fscanf(fin, "%llu", &new_eth_tx_bytes) != 1)
+				do_error("fscanf fails", false);
+			fclose(fin);
+			printf("  new_eth_tx_bytes:%llu\n",
+			       new_eth_tx_bytes);
+			bpf_map_lookup_elem(map_fd, &key, &qstats);
+			new_cg_tx_bytes = qstats.bytes_total;
+			delta_bytes = new_eth_tx_bytes - last_eth_tx_bytes;
+			last_eth_tx_bytes = new_eth_tx_bytes;
+			delta_rate = (delta_bytes * 8000000) / delta_time;
+			printf("%5d - eth_rate:%.1fGbps cg_rate:%.3fGbps",
+			       delta_ms, delta_rate/1000000000.0,
+			       rate/1000.0);
+			if (delta_rate < RATE_THRESHOLD) {
+				/* can increase cgroup rate limit, but first
+				 * check if we are using the current limit.
+				 * Currently increasing by 6.25%, unknown
+				 * if that is the optimal rate.
+				 */
+				int rate_diff100;
+
+				delta_bytes = new_cg_tx_bytes -
+					last_cg_tx_bytes;
+				last_cg_tx_bytes = new_cg_tx_bytes;
+				delta_rate = (delta_bytes * 8000000) /
+					delta_time;
+				printf(" rate:%.3fGbps",
+				       delta_rate/1000000000.0);
+				rate_diff100 = (((long long)rate)*1000000 -
+						     delta_rate) * 100 /
+					(((long long) rate) * 1000000);
+				printf("  rdiff:%d", rate_diff100);
+				if (rate_diff100  <= 3) {
+					rate += (rate >> 4);
+					if (rate > RATE_THRESHOLD / 1000000)
+						rate = RATE_THRESHOLD / 1000000;
+					qstats.rate = rate;
+					printf(" INC\n");
+				} else {
+					printf("\n");
+				}
+			} else {
+				/* Need to decrease cgroup rate limit.
+				 * Currently decreasing by 12.5%, unknown
+				 * if that is optimal
+				 */
+				printf(" DEC\n");
+				rate -= (rate >> 3);
+				if (rate < minRate)
+					rate = minRate;
+				qstats.rate = rate;
+			}
+			if (bpf_map_update_elem(map_fd, &key, &qstats, BPF_ANY))
+				do_error("update map element fails", false);
+		}
+	} else {
+		sleep(dur);
+	}
+	// Get stats!
+	if (stats_flag && bpf_map_lookup_elem(map_fd, &key, &qstats)) {
+		char fname[100];
+		FILE *fout;
+
+		if (!outFlag)
+			sprintf(fname, "hbm.%d.in", cg_id);
+		else
+			sprintf(fname, "hbm.%d.out", cg_id);
+		fout = fopen(fname, "w");
+		fprintf(fout, "id:%d\n", cg_id);
+		fprintf(fout, "ERROR: Could not lookup queue_stats\n");
+		fclose(fout);
+	} else if (stats_flag && qstats.lastPacketTime >
+		   qstats.firstPacketTime) {
+		long long delta_us = (qstats.lastPacketTime -
+				      qstats.firstPacketTime)/1000;
+		unsigned int rate_mbps = ((qstats.bytes_total -
+					   qstats.bytes_dropped) * 8 /
+					  delta_us);
+		double percent_pkts, percent_bytes;
+		char fname[100];
+		FILE *fout;
+		int k;
+		static const char *returnValNames[] = {
+			"DROP_PKT",
+			"ALLOW_PKT",
+			"DROP_PKT_CWR",
+			"ALLOW_PKT_CWR"
+		};
+#define RET_VAL_COUNT 4
+
+// Future support of ingress
+//		if (!outFlag)
+//			sprintf(fname, "hbm.%d.in", cg_id);
+//		else
+		sprintf(fname, "hbm.%d.out", cg_id);
+		fout = fopen(fname, "w");
+		fprintf(fout, "id:%d\n", cg_id);
+		fprintf(fout, "rate_mbps:%d\n", rate_mbps);
+		fprintf(fout, "duration:%.1f secs\n",
+			(qstats.lastPacketTime - qstats.firstPacketTime) /
+			1000000000.0);
+		fprintf(fout, "packets:%d\n", (int)qstats.pkts_total);
+		fprintf(fout, "bytes_MB:%d\n", (int)(qstats.bytes_total /
+						     1000000));
+		fprintf(fout, "pkts_dropped:%d\n", (int)qstats.pkts_dropped);
+		fprintf(fout, "bytes_dropped_MB:%d\n",
+			(int)(qstats.bytes_dropped /
+						       1000000));
+		// Marked Pkts and Bytes
+		percent_pkts = (qstats.pkts_marked * 100.0) /
+			(qstats.pkts_total + 1);
+		percent_bytes = (qstats.bytes_marked * 100.0) /
+			(qstats.bytes_total + 1);
+		fprintf(fout, "pkts_marked_percent:%6.2f\n", percent_pkts);
+		fprintf(fout, "bytes_marked_percent:%6.2f\n", percent_bytes);
+
+		// Dropped Pkts and Bytes
+		percent_pkts = (qstats.pkts_dropped * 100.0) /
+			(qstats.pkts_total + 1);
+		percent_bytes = (qstats.bytes_dropped * 100.0) /
+			(qstats.bytes_total + 1);
+		fprintf(fout, "pkts_dropped_percent:%6.2f\n", percent_pkts);
+		fprintf(fout, "bytes_dropped_percent:%6.2f\n", percent_bytes);
+
+		// ECN CE markings
+		percent_pkts = (qstats.pkts_ecn_ce * 100.0) /
+			(qstats.pkts_total + 1);
+		fprintf(fout, "pkts_ecn_ce:%6.2f (%d)\n", percent_pkts,
+			(int)qstats.pkts_ecn_ce);
+
+		// Average cwnd
+		fprintf(fout, "avg cwnd:%d\n",
+			(int)(qstats.sum_cwnd / (qstats.sum_cwnd_cnt + 1)));
+		// Average rtt
+		fprintf(fout, "avg rtt:%d\n",
+			(int)(qstats.sum_rtt / (qstats.pkts_total + 1)));
+		// Average credit
+		if (edt_flag)
+			fprintf(fout, "avg credit_ms:%.03f\n",
+				(qstats.sum_credit /
+				 (qstats.pkts_total + 1.0)) / 1000000.0);
+		else
+			fprintf(fout, "avg credit:%d\n",
+				(int)(qstats.sum_credit /
+				      (1500 * ((int)qstats.pkts_total ) + 1)));
+
+		// Return values stats
+		for (k = 0; k < RET_VAL_COUNT; k++) {
+			percent_pkts = (qstats.returnValCount[k] * 100.0) /
+				(qstats.pkts_total + 1);
+			fprintf(fout, "%s:%6.2f (%d)\n", returnValNames[k],
+				percent_pkts, (int)qstats.returnValCount[k]);
+		}
+		fclose(fout);
+	}
+
+	if (debugFlag)
+		read_trace_pipe2();
+	return rc;
+err:
+	rc = 1;
+
+	if (cg1)
+		close(cg1);
+	cleanup_cgroup_environment();
+
+	return rc;
+}
+
+static void Usage(void)
+{
+	printf("This program loads a cgroup skb BPF program to enforce\n"
+	       "cgroup output (egress) bandwidth limits.\n\n"
+	       "USAGE: hbm [-o] [-d]  [-l] [-n <id>] [--no_cn] [-r <rate>]\n"
+	       "           [-s] [-t <secs>] [-w] [-h] [prog]\n"
+	       "  Where:\n"
+	       "    -o         indicates egress direction (default)\n"
+	       "    -d         print BPF trace debug buffer\n"
+	       "    --edt      use fq's Earliest Departure Time\n"
+	       "    -l         also limit flows using loopback\n"
+	       "    -n <#>     to create cgroup \"/hbm#\" and attach prog\n"
+	       "               Default is /hbm1\n"
+	       "    --no_cn    disable CN notifications\n"
+	       "    -r <rate>  Rate in Mbps\n"
+	       "    -s         Update HBM stats\n"
+	       "    -t <time>  Exit after specified seconds (default is 0)\n"
+	       "    -w	       Work conserving flag. cgroup can increase\n"
+	       "               bandwidth beyond the rate limit specified\n"
+	       "               while there is available bandwidth. Current\n"
+	       "               implementation assumes there is only eth0\n"
+	       "               but can be extended to support multiple NICs\n"
+	       "    -h         print this info\n"
+	       "    prog       BPF program file name. Name defaults to\n"
+	       "                 hbm_out_kern.o\n");
+}
+
+int main(int argc, char **argv)
+{
+	char *prog = "hbm_out_kern.o";
+	int  k;
+	int cg_id = 1;
+	char *optstring = "iodln:r:st:wh";
+	struct option loptions[] = {
+		{"no_cn", 0, NULL, 1},
+		{"edt", 0, NULL, 2},
+		{NULL, 0, NULL, 0}
+	};
+
+	while ((k = getopt_long(argc, argv, optstring, loptions, NULL)) != -1) {
+		switch (k) {
+		case 1:
+			no_cn_flag = true;
+			break;
+		case 2:
+			prog = "hbm_edt_kern.o";
+			edt_flag = true;
+			break;
+		case'o':
+			break;
+		case 'd':
+			debugFlag = true;
+			break;
+		case 'l':
+			loopback_flag = true;
+			break;
+		case 'n':
+			cg_id = atoi(optarg);
+			break;
+		case 'r':
+			minRate = atoi(optarg) * 1.024;
+			rate = minRate;
+			break;
+		case 's':
+			stats_flag = true;
+			break;
+		case 't':
+			dur = atoi(optarg);
+			break;
+		case 'w':
+			work_conserving_flag = true;
+			break;
+		case '?':
+			if (optopt == 'n' || optopt == 'r' || optopt == 't')
+				fprintf(stderr,
+					"Option -%c requires an argument.\n\n",
+					optopt);
+		case 'h':
+			__fallthrough;
+		default:
+			Usage();
+			return 0;
+		}
+	}
+
+	if (optind < argc)
+		prog = argv[optind];
+	printf("HBM prog: %s\n", prog != NULL ? prog : "NULL");
+
+	return run_bpf_prog(prog, cg_id);
+}
diff --git a/samples/bpf/hbm.h b/samples/bpf/hbm.h
new file mode 100644
index 000000000..f0963ed6a
--- /dev/null
+++ b/samples/bpf/hbm.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Include file for Host Bandwidth Management (HBM) programs
+ */
+struct hbm_vqueue {
+	struct bpf_spin_lock lock;
+	/* 4 byte hole */
+	unsigned long long lasttime;	/* In ns */
+	int credit;			/* In bytes */
+	unsigned int rate;		/* In bytes per NS << 20 */
+};
+
+struct hbm_queue_stats {
+	unsigned long rate;		/* in Mbps*/
+	unsigned long stats:1,		/* get HBM stats (marked, dropped,..) */
+		loopback:1,		/* also limit flows using loopback */
+		no_cn:1;		/* do not use cn flags */
+	unsigned long long pkts_marked;
+	unsigned long long bytes_marked;
+	unsigned long long pkts_dropped;
+	unsigned long long bytes_dropped;
+	unsigned long long pkts_total;
+	unsigned long long bytes_total;
+	unsigned long long firstPacketTime;
+	unsigned long long lastPacketTime;
+	unsigned long long pkts_ecn_ce;
+	unsigned long long returnValCount[4];
+	unsigned long long sum_cwnd;
+	unsigned long long sum_rtt;
+	unsigned long long sum_cwnd_cnt;
+	long long sum_credit;
+};
diff --git a/samples/bpf/hbm_edt_kern.c b/samples/bpf/hbm_edt_kern.c
new file mode 100644
index 000000000..a65b677ac
--- /dev/null
+++ b/samples/bpf/hbm_edt_kern.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Sample Host Bandwidth Manager (HBM) BPF program.
+ *
+ * A cgroup skb BPF egress program to limit cgroup output bandwidth.
+ * It uses a modified virtual token bucket queue to limit average
+ * egress bandwidth. The implementation uses credits instead of tokens.
+ * Negative credits imply that queueing would have happened (this is
+ * a virtual queue, so no queueing is done by it. However, queueing may
+ * occur at the actual qdisc (which is not used for rate limiting).
+ *
+ * This implementation uses 3 thresholds, one to start marking packets and
+ * the other two to drop packets:
+ *                                  CREDIT
+ *        - <--------------------------|------------------------> +
+ *              |    |          |      0
+ *              |  Large pkt    |
+ *              |  drop thresh  |
+ *   Small pkt drop             Mark threshold
+ *       thresh
+ *
+ * The effect of marking depends on the type of packet:
+ * a) If the packet is ECN enabled and it is a TCP packet, then the packet
+ *    is ECN marked.
+ * b) If the packet is a TCP packet, then we probabilistically call tcp_cwr
+ *    to reduce the congestion window. The current implementation uses a linear
+ *    distribution (0% probability at marking threshold, 100% probability
+ *    at drop threshold).
+ * c) If the packet is not a TCP packet, then it is dropped.
+ *
+ * If the credit is below the drop threshold, the packet is dropped. If it
+ * is a TCP packet, then it also calls tcp_cwr since packets dropped by
+ * by a cgroup skb BPF program do not automatically trigger a call to
+ * tcp_cwr in the current kernel code.
+ *
+ * This BPF program actually uses 2 drop thresholds, one threshold
+ * for larger packets (>= 120 bytes) and another for smaller packets. This
+ * protects smaller packets such as SYNs, ACKs, etc.
+ *
+ * The default bandwidth limit is set at 1Gbps but this can be changed by
+ * a user program through a shared BPF map. In addition, by default this BPF
+ * program does not limit connections using loopback. This behavior can be
+ * overwritten by the user program. There is also an option to calculate
+ * some statistics, such as percent of packets marked or dropped, which
+ * a user program, such as hbm, can access.
+ */
+
+#include "hbm_kern.h"
+
+SEC("cgroup_skb/egress")
+int _hbm_out_cg(struct __sk_buff *skb)
+{
+	long long delta = 0, delta_send;
+	unsigned long long curtime, sendtime;
+	struct hbm_queue_stats *qsp = NULL;
+	unsigned int queue_index = 0;
+	bool congestion_flag = false;
+	bool ecn_ce_flag = false;
+	struct hbm_pkt_info pkti = {};
+	struct hbm_vqueue *qdp;
+	bool drop_flag = false;
+	bool cwr_flag = false;
+	int len = skb->len;
+	int rv = ALLOW_PKT;
+
+	qsp = bpf_map_lookup_elem(&queue_stats, &queue_index);
+
+	// Check if we should ignore loopback traffic
+	if (qsp != NULL && !qsp->loopback && (skb->ifindex == 1))
+		return ALLOW_PKT;
+
+	hbm_get_pkt_info(skb, &pkti);
+
+	// We may want to account for the length of headers in len
+	// calculation, like ETH header + overhead, specially if it
+	// is a gso packet. But I am not doing it right now.
+
+	qdp = bpf_get_local_storage(&queue_state, 0);
+	if (!qdp)
+		return ALLOW_PKT;
+	if (qdp->lasttime == 0)
+		hbm_init_edt_vqueue(qdp, 1024);
+
+	curtime = bpf_ktime_get_ns();
+
+	// Begin critical section
+	bpf_spin_lock(&qdp->lock);
+	delta = qdp->lasttime - curtime;
+	// bound bursts to 100us
+	if (delta < -BURST_SIZE_NS) {
+		// negative delta is a credit that allows bursts
+		qdp->lasttime = curtime - BURST_SIZE_NS;
+		delta = -BURST_SIZE_NS;
+	}
+	sendtime = qdp->lasttime;
+	delta_send = BYTES_TO_NS(len, qdp->rate);
+	__sync_add_and_fetch(&(qdp->lasttime), delta_send);
+	bpf_spin_unlock(&qdp->lock);
+	// End critical section
+
+	// Set EDT of packet
+	skb->tstamp = sendtime;
+
+	// Check if we should update rate
+	if (qsp != NULL && (qsp->rate * 128) != qdp->rate)
+		qdp->rate = qsp->rate * 128;
+
+	// Set flags (drop, congestion, cwr)
+	// last packet will be sent in the future, bound latency
+	if (delta > DROP_THRESH_NS || (delta > LARGE_PKT_DROP_THRESH_NS &&
+				       len > LARGE_PKT_THRESH)) {
+		drop_flag = true;
+		if (pkti.is_tcp && pkti.ecn == 0)
+			cwr_flag = true;
+	} else if (delta > MARK_THRESH_NS) {
+		if (pkti.is_tcp)
+			congestion_flag = true;
+		else
+			drop_flag = true;
+	}
+
+	if (congestion_flag) {
+		if (bpf_skb_ecn_set_ce(skb)) {
+			ecn_ce_flag = true;
+		} else {
+			if (pkti.is_tcp) {
+				unsigned int rand = bpf_get_prandom_u32();
+
+				if (delta >= MARK_THRESH_NS +
+				    (rand % MARK_REGION_SIZE_NS)) {
+					// Do congestion control
+					cwr_flag = true;
+				}
+			} else if (len > LARGE_PKT_THRESH) {
+				// Problem if too many small packets?
+				drop_flag = true;
+				congestion_flag = false;
+			}
+		}
+	}
+
+	if (pkti.is_tcp && drop_flag && pkti.packets_out <= 1) {
+		drop_flag = false;
+		cwr_flag = true;
+		congestion_flag = false;
+	}
+
+	if (qsp != NULL && qsp->no_cn)
+			cwr_flag = false;
+
+	hbm_update_stats(qsp, len, curtime, congestion_flag, drop_flag,
+			 cwr_flag, ecn_ce_flag, &pkti, (int) delta);
+
+	if (drop_flag) {
+		__sync_add_and_fetch(&(qdp->lasttime), -delta_send);
+		rv = DROP_PKT;
+	}
+
+	if (cwr_flag)
+		rv |= CWR;
+	return rv;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/hbm_kern.h b/samples/bpf/hbm_kern.h
new file mode 100644
index 000000000..e00f26f6a
--- /dev/null
+++ b/samples/bpf/hbm_kern.h
@@ -0,0 +1,217 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Include file for sample Host Bandwidth Manager (HBM) BPF programs
+ */
+#define KBUILD_MODNAME "foo"
+#include <stddef.h>
+#include <stdbool.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/filter.h>
+#include <uapi/linux/pkt_cls.h>
+#include <net/ipv6.h>
+#include <net/inet_ecn.h>
+#include <bpf/bpf_endian.h>
+#include <bpf/bpf_helpers.h>
+#include "hbm.h"
+
+#define DROP_PKT	0
+#define ALLOW_PKT	1
+#define TCP_ECN_OK	1
+#define CWR		2
+
+#ifndef HBM_DEBUG  // Define HBM_DEBUG to enable debugging
+#undef bpf_printk
+#define bpf_printk(fmt, ...)
+#endif
+
+#define INITIAL_CREDIT_PACKETS	100
+#define MAX_BYTES_PER_PACKET	1500
+#define MARK_THRESH		(40 * MAX_BYTES_PER_PACKET)
+#define DROP_THRESH		(80 * 5 * MAX_BYTES_PER_PACKET)
+#define LARGE_PKT_DROP_THRESH	(DROP_THRESH - (15 * MAX_BYTES_PER_PACKET))
+#define MARK_REGION_SIZE	(LARGE_PKT_DROP_THRESH - MARK_THRESH)
+#define LARGE_PKT_THRESH	120
+#define MAX_CREDIT		(100 * MAX_BYTES_PER_PACKET)
+#define INIT_CREDIT		(INITIAL_CREDIT_PACKETS * MAX_BYTES_PER_PACKET)
+
+// Time base accounting for fq's EDT
+#define BURST_SIZE_NS		100000 // 100us
+#define MARK_THRESH_NS		50000 // 50us
+#define DROP_THRESH_NS		500000 // 500us
+// Reserve 20us of queuing for small packets (less than 120 bytes)
+#define LARGE_PKT_DROP_THRESH_NS (DROP_THRESH_NS - 20000)
+#define MARK_REGION_SIZE_NS	(LARGE_PKT_DROP_THRESH_NS - MARK_THRESH_NS)
+
+// rate in bytes per ns << 20
+#define CREDIT_PER_NS(delta, rate) ((((u64)(delta)) * (rate)) >> 20)
+#define BYTES_PER_NS(delta, rate) ((((u64)(delta)) * (rate)) >> 20)
+#define BYTES_TO_NS(bytes, rate) div64_u64(((u64)(bytes)) << 20, (u64)(rate))
+
+struct {
+	__uint(type, BPF_MAP_TYPE_CGROUP_STORAGE);
+	__type(key, struct bpf_cgroup_storage_key);
+	__type(value, struct hbm_vqueue);
+} queue_state SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, 1);
+	__type(key, u32);
+	__type(value, struct hvm_queue_stats);
+} queue_stats SEC(".maps");
+
+struct hbm_pkt_info {
+	int	cwnd;
+	int	rtt;
+	int	packets_out;
+	bool	is_ip;
+	bool	is_tcp;
+	short	ecn;
+};
+
+static int get_tcp_info(struct __sk_buff *skb, struct hbm_pkt_info *pkti)
+{
+	struct bpf_sock *sk;
+	struct bpf_tcp_sock *tp;
+
+	sk = skb->sk;
+	if (sk) {
+		sk = bpf_sk_fullsock(sk);
+		if (sk) {
+			if (sk->protocol == IPPROTO_TCP) {
+				tp = bpf_tcp_sock(sk);
+				if (tp) {
+					pkti->cwnd = tp->snd_cwnd;
+					pkti->rtt = tp->srtt_us >> 3;
+					pkti->packets_out = tp->packets_out;
+					return 0;
+				}
+			}
+		}
+	}
+	pkti->cwnd = 0;
+	pkti->rtt = 0;
+	pkti->packets_out = 0;
+	return 1;
+}
+
+static void hbm_get_pkt_info(struct __sk_buff *skb,
+			     struct hbm_pkt_info *pkti)
+{
+	struct iphdr iph;
+	struct ipv6hdr *ip6h;
+
+	pkti->cwnd = 0;
+	pkti->rtt = 0;
+	bpf_skb_load_bytes(skb, 0, &iph, 12);
+	if (iph.version == 6) {
+		ip6h = (struct ipv6hdr *)&iph;
+		pkti->is_ip = true;
+		pkti->is_tcp = (ip6h->nexthdr == 6);
+		pkti->ecn = (ip6h->flow_lbl[0] >> 4) & INET_ECN_MASK;
+	} else if (iph.version == 4) {
+		pkti->is_ip = true;
+		pkti->is_tcp = (iph.protocol == 6);
+		pkti->ecn = iph.tos & INET_ECN_MASK;
+	} else {
+		pkti->is_ip = false;
+		pkti->is_tcp = false;
+		pkti->ecn = 0;
+	}
+	if (pkti->is_tcp)
+		get_tcp_info(skb, pkti);
+}
+
+static __always_inline void hbm_init_vqueue(struct hbm_vqueue *qdp, int rate)
+{
+	bpf_printk("Initializing queue_state, rate:%d\n", rate * 128);
+	qdp->lasttime = bpf_ktime_get_ns();
+	qdp->credit = INIT_CREDIT;
+	qdp->rate = rate * 128;
+}
+
+static __always_inline void hbm_init_edt_vqueue(struct hbm_vqueue *qdp,
+						int rate)
+{
+	unsigned long long curtime;
+
+	curtime = bpf_ktime_get_ns();
+	bpf_printk("Initializing queue_state, rate:%d\n", rate * 128);
+	qdp->lasttime = curtime - BURST_SIZE_NS;	// support initial burst
+	qdp->credit = 0;				// not used
+	qdp->rate = rate * 128;
+}
+
+static __always_inline void hbm_update_stats(struct hbm_queue_stats *qsp,
+					     int len,
+					     unsigned long long curtime,
+					     bool congestion_flag,
+					     bool drop_flag,
+					     bool cwr_flag,
+					     bool ecn_ce_flag,
+					     struct hbm_pkt_info *pkti,
+					     int credit)
+{
+	int rv = ALLOW_PKT;
+
+	if (qsp != NULL) {
+		// Following is needed for work conserving
+		__sync_add_and_fetch(&(qsp->bytes_total), len);
+		if (qsp->stats) {
+			// Optionally update statistics
+			if (qsp->firstPacketTime == 0)
+				qsp->firstPacketTime = curtime;
+			qsp->lastPacketTime = curtime;
+			__sync_add_and_fetch(&(qsp->pkts_total), 1);
+			if (congestion_flag) {
+				__sync_add_and_fetch(&(qsp->pkts_marked), 1);
+				__sync_add_and_fetch(&(qsp->bytes_marked), len);
+			}
+			if (drop_flag) {
+				__sync_add_and_fetch(&(qsp->pkts_dropped), 1);
+				__sync_add_and_fetch(&(qsp->bytes_dropped),
+						     len);
+			}
+			if (ecn_ce_flag)
+				__sync_add_and_fetch(&(qsp->pkts_ecn_ce), 1);
+			if (pkti->cwnd) {
+				__sync_add_and_fetch(&(qsp->sum_cwnd),
+						     pkti->cwnd);
+				__sync_add_and_fetch(&(qsp->sum_cwnd_cnt), 1);
+			}
+			if (pkti->rtt)
+				__sync_add_and_fetch(&(qsp->sum_rtt),
+						     pkti->rtt);
+			__sync_add_and_fetch(&(qsp->sum_credit), credit);
+
+			if (drop_flag)
+				rv = DROP_PKT;
+			if (cwr_flag)
+				rv |= 2;
+			if (rv == DROP_PKT)
+				__sync_add_and_fetch(&(qsp->returnValCount[0]),
+						     1);
+			else if (rv == ALLOW_PKT)
+				__sync_add_and_fetch(&(qsp->returnValCount[1]),
+						     1);
+			else if (rv == 2)
+				__sync_add_and_fetch(&(qsp->returnValCount[2]),
+						     1);
+			else if (rv == 3)
+				__sync_add_and_fetch(&(qsp->returnValCount[3]),
+						     1);
+		}
+	}
+}
diff --git a/samples/bpf/hbm_out_kern.c b/samples/bpf/hbm_out_kern.c
new file mode 100644
index 000000000..829934bd4
--- /dev/null
+++ b/samples/bpf/hbm_out_kern.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Sample Host Bandwidth Manager (HBM) BPF program.
+ *
+ * A cgroup skb BPF egress program to limit cgroup output bandwidth.
+ * It uses a modified virtual token bucket queue to limit average
+ * egress bandwidth. The implementation uses credits instead of tokens.
+ * Negative credits imply that queueing would have happened (this is
+ * a virtual queue, so no queueing is done by it. However, queueing may
+ * occur at the actual qdisc (which is not used for rate limiting).
+ *
+ * This implementation uses 3 thresholds, one to start marking packets and
+ * the other two to drop packets:
+ *                                  CREDIT
+ *        - <--------------------------|------------------------> +
+ *              |    |          |      0
+ *              |  Large pkt    |
+ *              |  drop thresh  |
+ *   Small pkt drop             Mark threshold
+ *       thresh
+ *
+ * The effect of marking depends on the type of packet:
+ * a) If the packet is ECN enabled and it is a TCP packet, then the packet
+ *    is ECN marked.
+ * b) If the packet is a TCP packet, then we probabilistically call tcp_cwr
+ *    to reduce the congestion window. The current implementation uses a linear
+ *    distribution (0% probability at marking threshold, 100% probability
+ *    at drop threshold).
+ * c) If the packet is not a TCP packet, then it is dropped.
+ *
+ * If the credit is below the drop threshold, the packet is dropped. If it
+ * is a TCP packet, then it also calls tcp_cwr since packets dropped by
+ * by a cgroup skb BPF program do not automatically trigger a call to
+ * tcp_cwr in the current kernel code.
+ *
+ * This BPF program actually uses 2 drop thresholds, one threshold
+ * for larger packets (>= 120 bytes) and another for smaller packets. This
+ * protects smaller packets such as SYNs, ACKs, etc.
+ *
+ * The default bandwidth limit is set at 1Gbps but this can be changed by
+ * a user program through a shared BPF map. In addition, by default this BPF
+ * program does not limit connections using loopback. This behavior can be
+ * overwritten by the user program. There is also an option to calculate
+ * some statistics, such as percent of packets marked or dropped, which
+ * the user program can access.
+ *
+ * A latter patch provides such a program (hbm.c)
+ */
+
+#include "hbm_kern.h"
+
+SEC("cgroup_skb/egress")
+int _hbm_out_cg(struct __sk_buff *skb)
+{
+	struct hbm_pkt_info pkti;
+	int len = skb->len;
+	unsigned int queue_index = 0;
+	unsigned long long curtime;
+	int credit;
+	signed long long delta = 0, new_credit;
+	int max_credit = MAX_CREDIT;
+	bool congestion_flag = false;
+	bool drop_flag = false;
+	bool cwr_flag = false;
+	bool ecn_ce_flag = false;
+	struct hbm_vqueue *qdp;
+	struct hbm_queue_stats *qsp = NULL;
+	int rv = ALLOW_PKT;
+
+	qsp = bpf_map_lookup_elem(&queue_stats, &queue_index);
+	if (qsp != NULL && !qsp->loopback && (skb->ifindex == 1))
+		return ALLOW_PKT;
+
+	hbm_get_pkt_info(skb, &pkti);
+
+	// We may want to account for the length of headers in len
+	// calculation, like ETH header + overhead, specially if it
+	// is a gso packet. But I am not doing it right now.
+
+	qdp = bpf_get_local_storage(&queue_state, 0);
+	if (!qdp)
+		return ALLOW_PKT;
+	else if (qdp->lasttime == 0)
+		hbm_init_vqueue(qdp, 1024);
+
+	curtime = bpf_ktime_get_ns();
+
+	// Begin critical section
+	bpf_spin_lock(&qdp->lock);
+	credit = qdp->credit;
+	delta = curtime - qdp->lasttime;
+	/* delta < 0 implies that another process with a curtime greater
+	 * than ours beat us to the critical section and already added
+	 * the new credit, so we should not add it ourselves
+	 */
+	if (delta > 0) {
+		qdp->lasttime = curtime;
+		new_credit = credit + CREDIT_PER_NS(delta, qdp->rate);
+		if (new_credit > MAX_CREDIT)
+			credit = MAX_CREDIT;
+		else
+			credit = new_credit;
+	}
+	credit -= len;
+	qdp->credit = credit;
+	bpf_spin_unlock(&qdp->lock);
+	// End critical section
+
+	// Check if we should update rate
+	if (qsp != NULL && (qsp->rate * 128) != qdp->rate) {
+		qdp->rate = qsp->rate * 128;
+		bpf_printk("Updating rate: %d (1sec:%llu bits)\n",
+			   (int)qdp->rate,
+			   CREDIT_PER_NS(1000000000, qdp->rate) * 8);
+	}
+
+	// Set flags (drop, congestion, cwr)
+	// Dropping => we are congested, so ignore congestion flag
+	if (credit < -DROP_THRESH ||
+	    (len > LARGE_PKT_THRESH && credit < -LARGE_PKT_DROP_THRESH)) {
+		// Very congested, set drop packet
+		drop_flag = true;
+		if (pkti.ecn)
+			congestion_flag = true;
+		else if (pkti.is_tcp)
+			cwr_flag = true;
+	} else if (credit < 0) {
+		// Congested, set congestion flag
+		if (pkti.ecn || pkti.is_tcp) {
+			if (credit < -MARK_THRESH)
+				congestion_flag = true;
+			else
+				congestion_flag = false;
+		} else {
+			congestion_flag = true;
+		}
+	}
+
+	if (congestion_flag) {
+		if (bpf_skb_ecn_set_ce(skb)) {
+			ecn_ce_flag = true;
+		} else {
+			if (pkti.is_tcp) {
+				unsigned int rand = bpf_get_prandom_u32();
+
+				if (-credit >= MARK_THRESH +
+				    (rand % MARK_REGION_SIZE)) {
+					// Do congestion control
+					cwr_flag = true;
+				}
+			} else if (len > LARGE_PKT_THRESH) {
+				// Problem if too many small packets?
+				drop_flag = true;
+			}
+		}
+	}
+
+	if (qsp != NULL)
+		if (qsp->no_cn)
+			cwr_flag = false;
+
+	hbm_update_stats(qsp, len, curtime, congestion_flag, drop_flag,
+			 cwr_flag, ecn_ce_flag, &pkti, credit);
+
+	if (drop_flag) {
+		__sync_add_and_fetch(&(qdp->credit), len);
+		rv = DROP_PKT;
+	}
+
+	if (cwr_flag)
+		rv |= 2;
+	return rv;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/ibumad_kern.c b/samples/bpf/ibumad_kern.c
new file mode 100644
index 000000000..3a91b4c19
--- /dev/null
+++ b/samples/bpf/ibumad_kern.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+
+/**
+ * ibumad BPF sample kernel side
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Copyright(c) 2018 Ira Weiny, Intel Corporation
+ */
+
+#define KBUILD_MODNAME "ibumad_count_pkts_by_class"
+#include <uapi/linux/bpf.h>
+
+#include <bpf/bpf_helpers.h>
+
+
+struct bpf_map_def SEC("maps") read_count = {
+	.type        = BPF_MAP_TYPE_ARRAY,
+	.key_size    = sizeof(u32), /* class; u32 required */
+	.value_size  = sizeof(u64), /* count of mads read */
+	.max_entries = 256, /* Room for all Classes */
+};
+
+struct bpf_map_def SEC("maps") write_count = {
+	.type        = BPF_MAP_TYPE_ARRAY,
+	.key_size    = sizeof(u32), /* class; u32 required */
+	.value_size  = sizeof(u64), /* count of mads written */
+	.max_entries = 256, /* Room for all Classes */
+};
+
+#undef DEBUG
+#ifndef DEBUG
+#undef bpf_printk
+#define bpf_printk(fmt, ...)
+#endif
+
+/* Taken from the current format defined in
+ * include/trace/events/ib_umad.h
+ * and
+ * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_read/format
+ * /sys/kernel/debug/tracing/events/ib_umad/ib_umad_write/format
+ */
+struct ib_umad_rw_args {
+	u64 pad;
+	u8 port_num;
+	u8 sl;
+	u8 path_bits;
+	u8 grh_present;
+	u32 id;
+	u32 status;
+	u32 timeout_ms;
+	u32 retires;
+	u32 length;
+	u32 qpn;
+	u32 qkey;
+	u8 gid_index;
+	u8 hop_limit;
+	u16 lid;
+	u16 attr_id;
+	u16 pkey_index;
+	u8 base_version;
+	u8 mgmt_class;
+	u8 class_version;
+	u8 method;
+	u32 flow_label;
+	u16 mad_status;
+	u16 class_specific;
+	u32 attr_mod;
+	u64 tid;
+	u8 gid[16];
+	u32 dev_index;
+	u8 traffic_class;
+};
+
+SEC("tracepoint/ib_umad/ib_umad_read_recv")
+int on_ib_umad_read_recv(struct ib_umad_rw_args *ctx)
+{
+	u64 zero = 0, *val;
+	u8 class = ctx->mgmt_class;
+
+	bpf_printk("ib_umad read recv : class 0x%x\n", class);
+
+	val = bpf_map_lookup_elem(&read_count, &class);
+	if (!val) {
+		bpf_map_update_elem(&read_count, &class, &zero, BPF_NOEXIST);
+		val = bpf_map_lookup_elem(&read_count, &class);
+		if (!val)
+			return 0;
+	}
+
+	(*val) += 1;
+
+	return 0;
+}
+SEC("tracepoint/ib_umad/ib_umad_read_send")
+int on_ib_umad_read_send(struct ib_umad_rw_args *ctx)
+{
+	u64 zero = 0, *val;
+	u8 class = ctx->mgmt_class;
+
+	bpf_printk("ib_umad read send : class 0x%x\n", class);
+
+	val = bpf_map_lookup_elem(&read_count, &class);
+	if (!val) {
+		bpf_map_update_elem(&read_count, &class, &zero, BPF_NOEXIST);
+		val = bpf_map_lookup_elem(&read_count, &class);
+		if (!val)
+			return 0;
+	}
+
+	(*val) += 1;
+
+	return 0;
+}
+SEC("tracepoint/ib_umad/ib_umad_write")
+int on_ib_umad_write(struct ib_umad_rw_args *ctx)
+{
+	u64 zero = 0, *val;
+	u8 class = ctx->mgmt_class;
+
+	bpf_printk("ib_umad write : class 0x%x\n", class);
+
+	val = bpf_map_lookup_elem(&write_count, &class);
+	if (!val) {
+		bpf_map_update_elem(&write_count, &class, &zero, BPF_NOEXIST);
+		val = bpf_map_lookup_elem(&write_count, &class);
+		if (!val)
+			return 0;
+	}
+
+	(*val) += 1;
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/ibumad_user.c b/samples/bpf/ibumad_user.c
new file mode 100644
index 000000000..fa06eef31
--- /dev/null
+++ b/samples/bpf/ibumad_user.c
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+
+/**
+ * ibumad BPF sample user side
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Copyright(c) 2018 Ira Weiny, Intel Corporation
+ */
+
+#include <linux/bpf.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <limits.h>
+
+#include <sys/resource.h>
+#include <getopt.h>
+#include <net/if.h>
+
+#include "bpf_load.h"
+#include "bpf_util.h"
+#include <bpf/libbpf.h>
+
+static void dump_counts(int fd)
+{
+	__u32 key;
+	__u64 value;
+
+	for (key = 0; key < 256; key++) {
+		if (bpf_map_lookup_elem(fd, &key, &value)) {
+			printf("failed to read key %u\n", key);
+			continue;
+		}
+		if (value)
+			printf("0x%02x : %llu\n", key, value);
+	}
+}
+
+static void dump_all_counts(void)
+{
+	printf("Read 'Class : count'\n");
+	dump_counts(map_fd[0]);
+	printf("Write 'Class : count'\n");
+	dump_counts(map_fd[1]);
+}
+
+static void dump_exit(int sig)
+{
+	dump_all_counts();
+	exit(0);
+}
+
+static const struct option long_options[] = {
+	{"help",      no_argument,       NULL, 'h'},
+	{"delay",     required_argument, NULL, 'd'},
+};
+
+static void usage(char *cmd)
+{
+	printf("eBPF test program to count packets from various IP addresses\n"
+		"Usage: %s <options>\n"
+		"       --help,   -h  this menu\n"
+		"       --delay,  -d  <delay>  wait <delay> sec between prints [1 - 1000000]\n"
+		, cmd
+		);
+}
+
+int main(int argc, char **argv)
+{
+	unsigned long delay = 5;
+	int longindex = 0;
+	int opt;
+	char bpf_file[256];
+
+	/* Create the eBPF kernel code path name.
+	 * This follows the pattern of all of the other bpf samples
+	 */
+	snprintf(bpf_file, sizeof(bpf_file), "%s_kern.o", argv[0]);
+
+	/* Do one final dump when exiting */
+	signal(SIGINT, dump_exit);
+	signal(SIGTERM, dump_exit);
+
+	while ((opt = getopt_long(argc, argv, "hd:rSw",
+				  long_options, &longindex)) != -1) {
+		switch (opt) {
+		case 'd':
+			delay = strtoul(optarg, NULL, 0);
+			if (delay == ULONG_MAX || delay < 0 ||
+			    delay > 1000000) {
+				fprintf(stderr, "ERROR: invalid delay : %s\n",
+					optarg);
+				usage(argv[0]);
+				return 1;
+			}
+			break;
+		default:
+		case 'h':
+			usage(argv[0]);
+			return 1;
+		}
+	}
+
+	if (load_bpf_file(bpf_file)) {
+		fprintf(stderr, "ERROR: failed to load eBPF from file : %s\n",
+			bpf_file);
+		return 1;
+	}
+
+	while (1) {
+		sleep(delay);
+		dump_all_counts();
+	}
+
+	return 0;
+}
diff --git a/samples/bpf/lathist_kern.c b/samples/bpf/lathist_kern.c
new file mode 100644
index 000000000..4adfcbbe6
--- /dev/null
+++ b/samples/bpf/lathist_kern.c
@@ -0,0 +1,99 @@
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2015 BMW Car IT GmbH
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/version.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+#define MAX_ENTRIES	20
+#define MAX_CPU		4
+
+/* We need to stick to static allocated memory (an array instead of
+ * hash table) because managing dynamic memory from the
+ * trace_preempt_[on|off] tracepoints hooks is not supported.
+ */
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, int);
+	__type(value, u64);
+	__uint(max_entries, MAX_CPU);
+} my_map SEC(".maps");
+
+SEC("kprobe/trace_preempt_off")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	int cpu = bpf_get_smp_processor_id();
+	u64 *ts = bpf_map_lookup_elem(&my_map, &cpu);
+
+	if (ts)
+		*ts = bpf_ktime_get_ns();
+
+	return 0;
+}
+
+static unsigned int log2(unsigned int v)
+{
+	unsigned int r;
+	unsigned int shift;
+
+	r = (v > 0xFFFF) << 4; v >>= r;
+	shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
+	shift = (v > 0xF) << 2; v >>= shift; r |= shift;
+	shift = (v > 0x3) << 1; v >>= shift; r |= shift;
+	r |= (v >> 1);
+
+	return r;
+}
+
+static unsigned int log2l(unsigned long v)
+{
+	unsigned int hi = v >> 32;
+
+	if (hi)
+		return log2(hi) + 32;
+	else
+		return log2(v);
+}
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, int);
+	__type(value, long);
+	__uint(max_entries, MAX_CPU * MAX_ENTRIES);
+} my_lat SEC(".maps");
+
+SEC("kprobe/trace_preempt_on")
+int bpf_prog2(struct pt_regs *ctx)
+{
+	u64 *ts, cur_ts, delta;
+	int key, cpu;
+	long *val;
+
+	cpu = bpf_get_smp_processor_id();
+	ts = bpf_map_lookup_elem(&my_map, &cpu);
+	if (!ts)
+		return 0;
+
+	cur_ts = bpf_ktime_get_ns();
+	delta = log2l(cur_ts - *ts);
+
+	if (delta > MAX_ENTRIES - 1)
+		delta = MAX_ENTRIES - 1;
+
+	key = cpu * MAX_ENTRIES + delta;
+	val = bpf_map_lookup_elem(&my_lat, &key);
+	if (val)
+		__sync_fetch_and_add((long *)val, 1);
+
+	return 0;
+
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/lathist_user.c b/samples/bpf/lathist_user.c
new file mode 100644
index 000000000..7d8ff2418
--- /dev/null
+++ b/samples/bpf/lathist_user.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2015 BMW Car IT GmbH
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+#define MAX_ENTRIES	20
+#define MAX_CPU		4
+#define MAX_STARS	40
+
+struct cpu_hist {
+	long data[MAX_ENTRIES];
+	long max;
+};
+
+static struct cpu_hist cpu_hist[MAX_CPU];
+
+static void stars(char *str, long val, long max, int width)
+{
+	int i;
+
+	for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
+		str[i] = '*';
+	if (val > max)
+		str[i - 1] = '+';
+	str[i] = '\0';
+}
+
+static void print_hist(void)
+{
+	char starstr[MAX_STARS];
+	struct cpu_hist *hist;
+	int i, j;
+
+	/* clear screen */
+	printf("\033[2J");
+
+	for (j = 0; j < MAX_CPU; j++) {
+		hist = &cpu_hist[j];
+
+		/* ignore CPUs without data (maybe offline?) */
+		if (hist->max == 0)
+			continue;
+
+		printf("CPU %d\n", j);
+		printf("      latency        : count     distribution\n");
+		for (i = 1; i <= MAX_ENTRIES; i++) {
+			stars(starstr, hist->data[i - 1], hist->max, MAX_STARS);
+			printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
+				(1l << i) >> 1, (1l << i) - 1,
+				hist->data[i - 1], MAX_STARS, starstr);
+		}
+	}
+}
+
+static void get_data(int fd)
+{
+	long key, value;
+	int c, i;
+
+	for (i = 0; i < MAX_CPU; i++)
+		cpu_hist[i].max = 0;
+
+	for (c = 0; c < MAX_CPU; c++) {
+		for (i = 0; i < MAX_ENTRIES; i++) {
+			key = c * MAX_ENTRIES + i;
+			bpf_map_lookup_elem(fd, &key, &value);
+
+			cpu_hist[c].data[i] = value;
+			if (value > cpu_hist[c].max)
+				cpu_hist[c].max = value;
+		}
+	}
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_link *links[2];
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	int map_fd, i = 0;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "my_lat");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		links[i] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[i])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[i] = NULL;
+			goto cleanup;
+		}
+		i++;
+	}
+
+	while (1) {
+		get_data(map_fd);
+		print_hist();
+		sleep(5);
+	}
+
+cleanup:
+	for (i--; i >= 0; i--)
+		bpf_link__destroy(links[i]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/lwt_len_hist.sh b/samples/bpf/lwt_len_hist.sh
new file mode 100755
index 000000000..0eda9754f
--- /dev/null
+++ b/samples/bpf/lwt_len_hist.sh
@@ -0,0 +1,40 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+NS1=lwt_ns1
+VETH0=tst_lwt1a
+VETH1=tst_lwt1b
+
+TRACE_ROOT=/sys/kernel/debug/tracing
+
+function cleanup {
+	# To reset saved histogram, remove pinned map
+	rm /sys/fs/bpf/tc/globals/lwt_len_hist_map
+	ip route del 192.168.253.2/32 dev $VETH0 2> /dev/null
+	ip link del $VETH0 2> /dev/null
+	ip link del $VETH1 2> /dev/null
+	ip netns exec $NS1 killall netserver
+	ip netns delete $NS1 2> /dev/null
+}
+
+cleanup
+
+ip netns add $NS1
+ip link add $VETH0 type veth peer name $VETH1
+ip link set dev $VETH0 up
+ip addr add 192.168.253.1/24 dev $VETH0
+ip link set $VETH1 netns $NS1
+ip netns exec $NS1 ip link set dev $VETH1 up
+ip netns exec $NS1 ip addr add 192.168.253.2/24 dev $VETH1
+ip netns exec $NS1 netserver
+
+echo 1 > ${TRACE_ROOT}/tracing_on
+cp /dev/null ${TRACE_ROOT}/trace
+ip route add 192.168.253.2/32 encap bpf out obj lwt_len_hist_kern.o section len_hist dev $VETH0
+netperf -H 192.168.253.2 -t TCP_STREAM
+cat ${TRACE_ROOT}/trace | grep -v '^#'
+./lwt_len_hist
+cleanup
+echo 0 > ${TRACE_ROOT}/tracing_on
+
+exit 0
diff --git a/samples/bpf/lwt_len_hist_kern.c b/samples/bpf/lwt_len_hist_kern.c
new file mode 100644
index 000000000..9ed63e10e
--- /dev/null
+++ b/samples/bpf/lwt_len_hist_kern.c
@@ -0,0 +1,82 @@
+/* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/in.h>
+#include <bpf/bpf_helpers.h>
+
+# define printk(fmt, ...)						\
+		({							\
+			char ____fmt[] = fmt;				\
+			bpf_trace_printk(____fmt, sizeof(____fmt),	\
+				     ##__VA_ARGS__);			\
+		})
+
+struct bpf_elf_map {
+	__u32 type;
+	__u32 size_key;
+	__u32 size_value;
+	__u32 max_elem;
+	__u32 flags;
+	__u32 id;
+	__u32 pinning;
+};
+
+struct bpf_elf_map SEC("maps") lwt_len_hist_map = {
+	.type = BPF_MAP_TYPE_PERCPU_HASH,
+	.size_key = sizeof(__u64),
+	.size_value = sizeof(__u64),
+	.pinning = 2,
+	.max_elem = 1024,
+};
+
+static unsigned int log2(unsigned int v)
+{
+	unsigned int r;
+	unsigned int shift;
+
+	r = (v > 0xFFFF) << 4; v >>= r;
+	shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
+	shift = (v > 0xF) << 2; v >>= shift; r |= shift;
+	shift = (v > 0x3) << 1; v >>= shift; r |= shift;
+	r |= (v >> 1);
+	return r;
+}
+
+static unsigned int log2l(unsigned long v)
+{
+	unsigned int hi = v >> 32;
+	if (hi)
+		return log2(hi) + 32;
+	else
+		return log2(v);
+}
+
+SEC("len_hist")
+int do_len_hist(struct __sk_buff *skb)
+{
+	__u64 *value, key, init_val = 1;
+
+	key = log2l(skb->len);
+
+	value = bpf_map_lookup_elem(&lwt_len_hist_map, &key);
+	if (value)
+		__sync_fetch_and_add(value, 1);
+	else
+		bpf_map_update_elem(&lwt_len_hist_map, &key, &init_val, BPF_ANY);
+
+	return BPF_OK;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/lwt_len_hist_user.c b/samples/bpf/lwt_len_hist_user.c
new file mode 100644
index 000000000..430a4b7e3
--- /dev/null
+++ b/samples/bpf/lwt_len_hist_user.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/unistd.h>
+#include <linux/bpf.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <arpa/inet.h>
+
+#include <bpf/bpf.h>
+#include "bpf_util.h"
+
+#define MAX_INDEX 64
+#define MAX_STARS 38
+
+static void stars(char *str, long val, long max, int width)
+{
+	int i;
+
+	for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
+		str[i] = '*';
+	if (val > max)
+		str[i - 1] = '+';
+	str[i] = '\0';
+}
+
+int main(int argc, char **argv)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	const char *map_filename = "/sys/fs/bpf/tc/globals/lwt_len_hist_map";
+	uint64_t values[nr_cpus], sum, max_value = 0, data[MAX_INDEX] = {};
+	uint64_t key = 0, next_key, max_key = 0;
+	char starstr[MAX_STARS];
+	int i, map_fd;
+
+	map_fd = bpf_obj_get(map_filename);
+	if (map_fd < 0) {
+		fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
+			map_filename, strerror(errno), errno);
+		return -1;
+	}
+
+	while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
+		if (next_key >= MAX_INDEX) {
+			fprintf(stderr, "Key %lu out of bounds\n", next_key);
+			continue;
+		}
+
+		bpf_map_lookup_elem(map_fd, &next_key, values);
+
+		sum = 0;
+		for (i = 0; i < nr_cpus; i++)
+			sum += values[i];
+
+		data[next_key] = sum;
+		if (sum && next_key > max_key)
+			max_key = next_key;
+
+		if (sum > max_value)
+			max_value = sum;
+
+		key = next_key;
+	}
+
+	for (i = 1; i <= max_key + 1; i++) {
+		stars(starstr, data[i - 1], max_value, MAX_STARS);
+		printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
+		       (1l << i) >> 1, (1l << i) - 1, data[i - 1],
+		       MAX_STARS, starstr);
+	}
+
+	close(map_fd);
+
+	return 0;
+}
diff --git a/samples/bpf/map_perf_test_kern.c b/samples/bpf/map_perf_test_kern.c
new file mode 100644
index 000000000..8773f22b6
--- /dev/null
+++ b/samples/bpf/map_perf_test_kern.c
@@ -0,0 +1,291 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+#include "trace_common.h"
+
+#define MAX_ENTRIES 1000
+#define MAX_NR_CPUS 1024
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, MAX_ENTRIES);
+} hash_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_LRU_HASH);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, 10000);
+} lru_hash_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_LRU_HASH);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, 10000);
+	__uint(map_flags, BPF_F_NO_COMMON_LRU);
+} nocommon_lru_hash_map SEC(".maps");
+
+struct inner_lru {
+	__uint(type, BPF_MAP_TYPE_LRU_HASH);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, MAX_ENTRIES);
+	__uint(map_flags, BPF_F_NUMA_NODE);
+	__uint(numa_node, 0);
+} inner_lru_hash_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
+	__uint(max_entries, MAX_NR_CPUS);
+	__uint(key_size, sizeof(u32));
+	__array(values, struct inner_lru); /* use inner_lru as inner map */
+} array_of_lru_hashs SEC(".maps") = {
+	/* statically initialize the first element */
+	.values = { &inner_lru_hash_map },
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, sizeof(long));
+	__uint(max_entries, MAX_ENTRIES);
+} percpu_hash_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, MAX_ENTRIES);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+} hash_map_alloc SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, sizeof(long));
+	__uint(max_entries, MAX_ENTRIES);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+} percpu_hash_map_alloc SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_LPM_TRIE);
+	__uint(key_size, 8);
+	__uint(value_size, sizeof(long));
+	__uint(max_entries, 10000);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+} lpm_trie_map_alloc SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, MAX_ENTRIES);
+} array_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_LRU_HASH);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, MAX_ENTRIES);
+} lru_hash_lookup_map SEC(".maps");
+
+SEC("kprobe/" SYSCALL(sys_getuid))
+int stress_hmap(struct pt_regs *ctx)
+{
+	u32 key = bpf_get_current_pid_tgid();
+	long init_val = 1;
+	long *value;
+
+	bpf_map_update_elem(&hash_map, &key, &init_val, BPF_ANY);
+	value = bpf_map_lookup_elem(&hash_map, &key);
+	if (value)
+		bpf_map_delete_elem(&hash_map, &key);
+
+	return 0;
+}
+
+SEC("kprobe/" SYSCALL(sys_geteuid))
+int stress_percpu_hmap(struct pt_regs *ctx)
+{
+	u32 key = bpf_get_current_pid_tgid();
+	long init_val = 1;
+	long *value;
+
+	bpf_map_update_elem(&percpu_hash_map, &key, &init_val, BPF_ANY);
+	value = bpf_map_lookup_elem(&percpu_hash_map, &key);
+	if (value)
+		bpf_map_delete_elem(&percpu_hash_map, &key);
+	return 0;
+}
+
+SEC("kprobe/" SYSCALL(sys_getgid))
+int stress_hmap_alloc(struct pt_regs *ctx)
+{
+	u32 key = bpf_get_current_pid_tgid();
+	long init_val = 1;
+	long *value;
+
+	bpf_map_update_elem(&hash_map_alloc, &key, &init_val, BPF_ANY);
+	value = bpf_map_lookup_elem(&hash_map_alloc, &key);
+	if (value)
+		bpf_map_delete_elem(&hash_map_alloc, &key);
+	return 0;
+}
+
+SEC("kprobe/" SYSCALL(sys_getegid))
+int stress_percpu_hmap_alloc(struct pt_regs *ctx)
+{
+	u32 key = bpf_get_current_pid_tgid();
+	long init_val = 1;
+	long *value;
+
+	bpf_map_update_elem(&percpu_hash_map_alloc, &key, &init_val, BPF_ANY);
+	value = bpf_map_lookup_elem(&percpu_hash_map_alloc, &key);
+	if (value)
+		bpf_map_delete_elem(&percpu_hash_map_alloc, &key);
+	return 0;
+}
+
+SEC("kprobe/" SYSCALL(sys_connect))
+int stress_lru_hmap_alloc(struct pt_regs *ctx)
+{
+	struct pt_regs *real_regs = (struct pt_regs *)PT_REGS_PARM1_CORE(ctx);
+	char fmt[] = "Failed at stress_lru_hmap_alloc. ret:%dn";
+	union {
+		u16 dst6[8];
+		struct {
+			u16 magic0;
+			u16 magic1;
+			u16 tcase;
+			u16 unused16;
+			u32 unused32;
+			u32 key;
+		};
+	} test_params;
+	struct sockaddr_in6 *in6;
+	u16 test_case;
+	int addrlen, ret;
+	long val = 1;
+	u32 key = 0;
+
+	in6 = (struct sockaddr_in6 *)PT_REGS_PARM2_CORE(real_regs);
+	addrlen = (int)PT_REGS_PARM3_CORE(real_regs);
+
+	if (addrlen != sizeof(*in6))
+		return 0;
+
+	ret = bpf_probe_read_user(test_params.dst6, sizeof(test_params.dst6),
+				  &in6->sin6_addr);
+	if (ret)
+		goto done;
+
+	if (test_params.magic0 != 0xdead ||
+	    test_params.magic1 != 0xbeef)
+		return 0;
+
+	test_case = test_params.tcase;
+	if (test_case != 3)
+		key = bpf_get_prandom_u32();
+
+	if (test_case == 0) {
+		ret = bpf_map_update_elem(&lru_hash_map, &key, &val, BPF_ANY);
+	} else if (test_case == 1) {
+		ret = bpf_map_update_elem(&nocommon_lru_hash_map, &key, &val,
+					  BPF_ANY);
+	} else if (test_case == 2) {
+		void *nolocal_lru_map;
+		int cpu = bpf_get_smp_processor_id();
+
+		nolocal_lru_map = bpf_map_lookup_elem(&array_of_lru_hashs,
+						      &cpu);
+		if (!nolocal_lru_map) {
+			ret = -ENOENT;
+			goto done;
+		}
+
+		ret = bpf_map_update_elem(nolocal_lru_map, &key, &val,
+					  BPF_ANY);
+	} else if (test_case == 3) {
+		u32 i;
+
+		key = test_params.key;
+
+#pragma clang loop unroll(full)
+		for (i = 0; i < 32; i++) {
+			bpf_map_lookup_elem(&lru_hash_lookup_map, &key);
+			key++;
+		}
+	} else {
+		ret = -EINVAL;
+	}
+
+done:
+	if (ret)
+		bpf_trace_printk(fmt, sizeof(fmt), ret);
+
+	return 0;
+}
+
+SEC("kprobe/" SYSCALL(sys_gettid))
+int stress_lpm_trie_map_alloc(struct pt_regs *ctx)
+{
+	union {
+		u32 b32[2];
+		u8 b8[8];
+	} key;
+	unsigned int i;
+
+	key.b32[0] = 32;
+	key.b8[4] = 192;
+	key.b8[5] = 168;
+	key.b8[6] = 0;
+	key.b8[7] = 1;
+
+#pragma clang loop unroll(full)
+	for (i = 0; i < 32; ++i)
+		bpf_map_lookup_elem(&lpm_trie_map_alloc, &key);
+
+	return 0;
+}
+
+SEC("kprobe/" SYSCALL(sys_getpgid))
+int stress_hash_map_lookup(struct pt_regs *ctx)
+{
+	u32 key = 1, i;
+	long *value;
+
+#pragma clang loop unroll(full)
+	for (i = 0; i < 64; ++i)
+		value = bpf_map_lookup_elem(&hash_map, &key);
+
+	return 0;
+}
+
+SEC("kprobe/" SYSCALL(sys_getppid))
+int stress_array_map_lookup(struct pt_regs *ctx)
+{
+	u32 key = 1, i;
+	long *value;
+
+#pragma clang loop unroll(full)
+	for (i = 0; i < 64; ++i)
+		value = bpf_map_lookup_elem(&array_map, &key);
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/map_perf_test_user.c b/samples/bpf/map_perf_test_user.c
new file mode 100644
index 000000000..8b13230b4
--- /dev/null
+++ b/samples/bpf/map_perf_test_user.c
@@ -0,0 +1,507 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#define _GNU_SOURCE
+#include <sched.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <asm/unistd.h>
+#include <unistd.h>
+#include <assert.h>
+#include <sys/wait.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <time.h>
+#include <sys/resource.h>
+#include <arpa/inet.h>
+#include <errno.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#define TEST_BIT(t) (1U << (t))
+#define MAX_NR_CPUS 1024
+
+static __u64 time_get_ns(void)
+{
+	struct timespec ts;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
+}
+
+enum test_type {
+	HASH_PREALLOC,
+	PERCPU_HASH_PREALLOC,
+	HASH_KMALLOC,
+	PERCPU_HASH_KMALLOC,
+	LRU_HASH_PREALLOC,
+	NOCOMMON_LRU_HASH_PREALLOC,
+	LPM_KMALLOC,
+	HASH_LOOKUP,
+	ARRAY_LOOKUP,
+	INNER_LRU_HASH_PREALLOC,
+	LRU_HASH_LOOKUP,
+	NR_TESTS,
+};
+
+const char *test_map_names[NR_TESTS] = {
+	[HASH_PREALLOC] = "hash_map",
+	[PERCPU_HASH_PREALLOC] = "percpu_hash_map",
+	[HASH_KMALLOC] = "hash_map_alloc",
+	[PERCPU_HASH_KMALLOC] = "percpu_hash_map_alloc",
+	[LRU_HASH_PREALLOC] = "lru_hash_map",
+	[NOCOMMON_LRU_HASH_PREALLOC] = "nocommon_lru_hash_map",
+	[LPM_KMALLOC] = "lpm_trie_map_alloc",
+	[HASH_LOOKUP] = "hash_map",
+	[ARRAY_LOOKUP] = "array_map",
+	[INNER_LRU_HASH_PREALLOC] = "inner_lru_hash_map",
+	[LRU_HASH_LOOKUP] = "lru_hash_lookup_map",
+};
+
+enum map_idx {
+	array_of_lru_hashs_idx,
+	hash_map_alloc_idx,
+	lru_hash_lookup_idx,
+	NR_IDXES,
+};
+
+static int map_fd[NR_IDXES];
+
+static int test_flags = ~0;
+static uint32_t num_map_entries;
+static uint32_t inner_lru_hash_size;
+static int lru_hash_lookup_test_entries = 32;
+static uint32_t max_cnt = 1000000;
+
+static int check_test_flags(enum test_type t)
+{
+	return test_flags & TEST_BIT(t);
+}
+
+static void test_hash_prealloc(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_getuid);
+	printf("%d:hash_map_perf pre-alloc %lld events per sec\n",
+	       cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
+}
+
+static int pre_test_lru_hash_lookup(int tasks)
+{
+	int fd = map_fd[lru_hash_lookup_idx];
+	uint32_t key;
+	long val = 1;
+	int ret;
+
+	if (num_map_entries > lru_hash_lookup_test_entries)
+		lru_hash_lookup_test_entries = num_map_entries;
+
+	/* Populate the lru_hash_map for LRU_HASH_LOOKUP perf test.
+	 *
+	 * It is fine that the user requests for a map with
+	 * num_map_entries < 32 and some of the later lru hash lookup
+	 * may return not found.  For LRU map, we are not interested
+	 * in such small map performance.
+	 */
+	for (key = 0; key < lru_hash_lookup_test_entries; key++) {
+		ret = bpf_map_update_elem(fd, &key, &val, BPF_NOEXIST);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void do_test_lru(enum test_type test, int cpu)
+{
+	static int inner_lru_map_fds[MAX_NR_CPUS];
+
+	struct sockaddr_in6 in6 = { .sin6_family = AF_INET6 };
+	const char *test_name;
+	__u64 start_time;
+	int i, ret;
+
+	if (test == INNER_LRU_HASH_PREALLOC && cpu) {
+		/* If CPU is not 0, create inner_lru hash map and insert the fd
+		 * value into the array_of_lru_hash map. In case of CPU 0,
+		 * 'inner_lru_hash_map' was statically inserted on the map init
+		 */
+		int outer_fd = map_fd[array_of_lru_hashs_idx];
+		unsigned int mycpu, mynode;
+
+		assert(cpu < MAX_NR_CPUS);
+
+		ret = syscall(__NR_getcpu, &mycpu, &mynode, NULL);
+		assert(!ret);
+
+		inner_lru_map_fds[cpu] =
+			bpf_create_map_node(BPF_MAP_TYPE_LRU_HASH,
+					    test_map_names[INNER_LRU_HASH_PREALLOC],
+					    sizeof(uint32_t),
+					    sizeof(long),
+					    inner_lru_hash_size, 0,
+					    mynode);
+		if (inner_lru_map_fds[cpu] == -1) {
+			printf("cannot create BPF_MAP_TYPE_LRU_HASH %s(%d)\n",
+			       strerror(errno), errno);
+			exit(1);
+		}
+
+		ret = bpf_map_update_elem(outer_fd, &cpu,
+					  &inner_lru_map_fds[cpu],
+					  BPF_ANY);
+		if (ret) {
+			printf("cannot update ARRAY_OF_LRU_HASHS with key:%u. %s(%d)\n",
+			       cpu, strerror(errno), errno);
+			exit(1);
+		}
+	}
+
+	in6.sin6_addr.s6_addr16[0] = 0xdead;
+	in6.sin6_addr.s6_addr16[1] = 0xbeef;
+
+	if (test == LRU_HASH_PREALLOC) {
+		test_name = "lru_hash_map_perf";
+		in6.sin6_addr.s6_addr16[2] = 0;
+	} else if (test == NOCOMMON_LRU_HASH_PREALLOC) {
+		test_name = "nocommon_lru_hash_map_perf";
+		in6.sin6_addr.s6_addr16[2] = 1;
+	} else if (test == INNER_LRU_HASH_PREALLOC) {
+		test_name = "inner_lru_hash_map_perf";
+		in6.sin6_addr.s6_addr16[2] = 2;
+	} else if (test == LRU_HASH_LOOKUP) {
+		test_name = "lru_hash_lookup_perf";
+		in6.sin6_addr.s6_addr16[2] = 3;
+		in6.sin6_addr.s6_addr32[3] = 0;
+	} else {
+		assert(0);
+	}
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++) {
+		ret = connect(-1, (const struct sockaddr *)&in6, sizeof(in6));
+		assert(ret == -1 && errno == EBADF);
+		if (in6.sin6_addr.s6_addr32[3] <
+		    lru_hash_lookup_test_entries - 32)
+			in6.sin6_addr.s6_addr32[3] += 32;
+		else
+			in6.sin6_addr.s6_addr32[3] = 0;
+	}
+	printf("%d:%s pre-alloc %lld events per sec\n",
+	       cpu, test_name,
+	       max_cnt * 1000000000ll / (time_get_ns() - start_time));
+}
+
+static void test_lru_hash_prealloc(int cpu)
+{
+	do_test_lru(LRU_HASH_PREALLOC, cpu);
+}
+
+static void test_nocommon_lru_hash_prealloc(int cpu)
+{
+	do_test_lru(NOCOMMON_LRU_HASH_PREALLOC, cpu);
+}
+
+static void test_inner_lru_hash_prealloc(int cpu)
+{
+	do_test_lru(INNER_LRU_HASH_PREALLOC, cpu);
+}
+
+static void test_lru_hash_lookup(int cpu)
+{
+	do_test_lru(LRU_HASH_LOOKUP, cpu);
+}
+
+static void test_percpu_hash_prealloc(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_geteuid);
+	printf("%d:percpu_hash_map_perf pre-alloc %lld events per sec\n",
+	       cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
+}
+
+static void test_hash_kmalloc(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_getgid);
+	printf("%d:hash_map_perf kmalloc %lld events per sec\n",
+	       cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
+}
+
+static void test_percpu_hash_kmalloc(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_getegid);
+	printf("%d:percpu_hash_map_perf kmalloc %lld events per sec\n",
+	       cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
+}
+
+static void test_lpm_kmalloc(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_gettid);
+	printf("%d:lpm_perf kmalloc %lld events per sec\n",
+	       cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
+}
+
+static void test_hash_lookup(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_getpgid, 0);
+	printf("%d:hash_lookup %lld lookups per sec\n",
+	       cpu, max_cnt * 1000000000ll * 64 / (time_get_ns() - start_time));
+}
+
+static void test_array_lookup(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_getppid, 0);
+	printf("%d:array_lookup %lld lookups per sec\n",
+	       cpu, max_cnt * 1000000000ll * 64 / (time_get_ns() - start_time));
+}
+
+typedef int (*pre_test_func)(int tasks);
+const pre_test_func pre_test_funcs[] = {
+	[LRU_HASH_LOOKUP] = pre_test_lru_hash_lookup,
+};
+
+typedef void (*test_func)(int cpu);
+const test_func test_funcs[] = {
+	[HASH_PREALLOC] = test_hash_prealloc,
+	[PERCPU_HASH_PREALLOC] = test_percpu_hash_prealloc,
+	[HASH_KMALLOC] = test_hash_kmalloc,
+	[PERCPU_HASH_KMALLOC] = test_percpu_hash_kmalloc,
+	[LRU_HASH_PREALLOC] = test_lru_hash_prealloc,
+	[NOCOMMON_LRU_HASH_PREALLOC] = test_nocommon_lru_hash_prealloc,
+	[LPM_KMALLOC] = test_lpm_kmalloc,
+	[HASH_LOOKUP] = test_hash_lookup,
+	[ARRAY_LOOKUP] = test_array_lookup,
+	[INNER_LRU_HASH_PREALLOC] = test_inner_lru_hash_prealloc,
+	[LRU_HASH_LOOKUP] = test_lru_hash_lookup,
+};
+
+static int pre_test(int tasks)
+{
+	int i;
+
+	for (i = 0; i < NR_TESTS; i++) {
+		if (pre_test_funcs[i] && check_test_flags(i)) {
+			int ret = pre_test_funcs[i](tasks);
+
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void loop(int cpu)
+{
+	cpu_set_t cpuset;
+	int i;
+
+	CPU_ZERO(&cpuset);
+	CPU_SET(cpu, &cpuset);
+	sched_setaffinity(0, sizeof(cpuset), &cpuset);
+
+	for (i = 0; i < NR_TESTS; i++) {
+		if (check_test_flags(i))
+			test_funcs[i](cpu);
+	}
+}
+
+static void run_perf_test(int tasks)
+{
+	pid_t pid[tasks];
+	int i;
+
+	assert(!pre_test(tasks));
+
+	for (i = 0; i < tasks; i++) {
+		pid[i] = fork();
+		if (pid[i] == 0) {
+			loop(i);
+			exit(0);
+		} else if (pid[i] == -1) {
+			printf("couldn't spawn #%d process\n", i);
+			exit(1);
+		}
+	}
+	for (i = 0; i < tasks; i++) {
+		int status;
+
+		assert(waitpid(pid[i], &status, 0) == pid[i]);
+		assert(status == 0);
+	}
+}
+
+static void fill_lpm_trie(void)
+{
+	struct bpf_lpm_trie_key *key;
+	unsigned long value = 0;
+	unsigned int i;
+	int r;
+
+	key = alloca(sizeof(*key) + 4);
+	key->prefixlen = 32;
+
+	for (i = 0; i < 512; ++i) {
+		key->prefixlen = rand() % 33;
+		key->data[0] = rand() & 0xff;
+		key->data[1] = rand() & 0xff;
+		key->data[2] = rand() & 0xff;
+		key->data[3] = rand() & 0xff;
+		r = bpf_map_update_elem(map_fd[hash_map_alloc_idx],
+					key, &value, 0);
+		assert(!r);
+	}
+
+	key->prefixlen = 32;
+	key->data[0] = 192;
+	key->data[1] = 168;
+	key->data[2] = 0;
+	key->data[3] = 1;
+	value = 128;
+
+	r = bpf_map_update_elem(map_fd[hash_map_alloc_idx], key, &value, 0);
+	assert(!r);
+}
+
+static void fixup_map(struct bpf_object *obj)
+{
+	struct bpf_map *map;
+	int i;
+
+	bpf_object__for_each_map(map, obj) {
+		const char *name = bpf_map__name(map);
+
+		/* Only change the max_entries for the enabled test(s) */
+		for (i = 0; i < NR_TESTS; i++) {
+			if (!strcmp(test_map_names[i], name) &&
+			    (check_test_flags(i))) {
+				bpf_map__resize(map, num_map_entries);
+				continue;
+			}
+		}
+	}
+
+	inner_lru_hash_size = num_map_entries;
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	int nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+	struct bpf_link *links[8];
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	struct bpf_map *map;
+	char filename[256];
+	int i = 0;
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	if (argc > 1)
+		test_flags = atoi(argv[1]) ? : test_flags;
+
+	if (argc > 2)
+		nr_cpus = atoi(argv[2]) ? : nr_cpus;
+
+	if (argc > 3)
+		num_map_entries = atoi(argv[3]);
+
+	if (argc > 4)
+		max_cnt = atoi(argv[4]);
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	map = bpf_object__find_map_by_name(obj, "inner_lru_hash_map");
+	if (libbpf_get_error(map)) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	inner_lru_hash_size = bpf_map__max_entries(map);
+	if (!inner_lru_hash_size) {
+		fprintf(stderr, "ERROR: failed to get map attribute\n");
+		goto cleanup;
+	}
+
+	/* resize BPF map prior to loading */
+	if (num_map_entries > 0)
+		fixup_map(obj);
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "array_of_lru_hashs");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "hash_map_alloc");
+	map_fd[2] = bpf_object__find_map_fd_by_name(obj, "lru_hash_lookup_map");
+	if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		links[i] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[i])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[i] = NULL;
+			goto cleanup;
+		}
+		i++;
+	}
+
+	fill_lpm_trie();
+
+	run_perf_test(nr_cpus);
+
+cleanup:
+	for (i--; i >= 0; i--)
+		bpf_link__destroy(links[i]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/offwaketime_kern.c b/samples/bpf/offwaketime_kern.c
new file mode 100644
index 000000000..14b792915
--- /dev/null
+++ b/samples/bpf/offwaketime_kern.c
@@ -0,0 +1,157 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/ptrace.h>
+#include <uapi/linux/perf_event.h>
+#include <linux/version.h>
+#include <linux/sched.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#define _(P)                                                                   \
+	({                                                                     \
+		typeof(P) val;                                                 \
+		bpf_probe_read_kernel(&val, sizeof(val), &(P));                \
+		val;                                                           \
+	})
+
+#define MINBLOCK_US	1
+
+struct key_t {
+	char waker[TASK_COMM_LEN];
+	char target[TASK_COMM_LEN];
+	u32 wret;
+	u32 tret;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, struct key_t);
+	__type(value, u64);
+	__uint(max_entries, 10000);
+} counts SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, u64);
+	__uint(max_entries, 10000);
+} start SEC(".maps");
+
+struct wokeby_t {
+	char name[TASK_COMM_LEN];
+	u32 ret;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, struct wokeby_t);
+	__uint(max_entries, 10000);
+} wokeby SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
+	__uint(max_entries, 10000);
+} stackmap SEC(".maps");
+
+#define STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
+
+SEC("kprobe/try_to_wake_up")
+int waker(struct pt_regs *ctx)
+{
+	struct task_struct *p = (void *) PT_REGS_PARM1(ctx);
+	struct wokeby_t woke;
+	u32 pid;
+
+	pid = _(p->pid);
+
+	bpf_get_current_comm(&woke.name, sizeof(woke.name));
+	woke.ret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
+
+	bpf_map_update_elem(&wokeby, &pid, &woke, BPF_ANY);
+	return 0;
+}
+
+static inline int update_counts(void *ctx, u32 pid, u64 delta)
+{
+	struct wokeby_t *woke;
+	u64 zero = 0, *val;
+	struct key_t key;
+
+	__builtin_memset(&key.waker, 0, sizeof(key.waker));
+	bpf_get_current_comm(&key.target, sizeof(key.target));
+	key.tret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
+	key.wret = 0;
+
+	woke = bpf_map_lookup_elem(&wokeby, &pid);
+	if (woke) {
+		key.wret = woke->ret;
+		__builtin_memcpy(&key.waker, woke->name, sizeof(key.waker));
+		bpf_map_delete_elem(&wokeby, &pid);
+	}
+
+	val = bpf_map_lookup_elem(&counts, &key);
+	if (!val) {
+		bpf_map_update_elem(&counts, &key, &zero, BPF_NOEXIST);
+		val = bpf_map_lookup_elem(&counts, &key);
+		if (!val)
+			return 0;
+	}
+	(*val) += delta;
+	return 0;
+}
+
+#if 1
+/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */
+struct sched_switch_args {
+	unsigned long long pad;
+	char prev_comm[16];
+	int prev_pid;
+	int prev_prio;
+	long long prev_state;
+	char next_comm[16];
+	int next_pid;
+	int next_prio;
+};
+SEC("tracepoint/sched/sched_switch")
+int oncpu(struct sched_switch_args *ctx)
+{
+	/* record previous thread sleep time */
+	u32 pid = ctx->prev_pid;
+#else
+SEC("kprobe/finish_task_switch")
+int oncpu(struct pt_regs *ctx)
+{
+	struct task_struct *p = (void *) PT_REGS_PARM1(ctx);
+	/* record previous thread sleep time */
+	u32 pid = _(p->pid);
+#endif
+	u64 delta, ts, *tsp;
+
+	ts = bpf_ktime_get_ns();
+	bpf_map_update_elem(&start, &pid, &ts, BPF_ANY);
+
+	/* calculate current thread's delta time */
+	pid = bpf_get_current_pid_tgid();
+	tsp = bpf_map_lookup_elem(&start, &pid);
+	if (!tsp)
+		/* missed start or filtered */
+		return 0;
+
+	delta = bpf_ktime_get_ns() - *tsp;
+	bpf_map_delete_elem(&start, &pid);
+	delta = delta / 1000;
+	if (delta < MINBLOCK_US)
+		return 0;
+
+	return update_counts(ctx, pid, delta);
+}
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/offwaketime_user.c b/samples/bpf/offwaketime_user.c
new file mode 100644
index 000000000..5734cfdaa
--- /dev/null
+++ b/samples/bpf/offwaketime_user.c
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <linux/perf_event.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <sys/resource.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include "trace_helpers.h"
+
+#define PRINT_RAW_ADDR 0
+
+/* counts, stackmap */
+static int map_fd[2];
+
+static void print_ksym(__u64 addr)
+{
+	struct ksym *sym;
+
+	if (!addr)
+		return;
+	sym = ksym_search(addr);
+	if (!sym) {
+		printf("ksym not found. Is kallsyms loaded?\n");
+		return;
+	}
+
+	if (PRINT_RAW_ADDR)
+		printf("%s/%llx;", sym->name, addr);
+	else
+		printf("%s;", sym->name);
+}
+
+#define TASK_COMM_LEN 16
+
+struct key_t {
+	char waker[TASK_COMM_LEN];
+	char target[TASK_COMM_LEN];
+	__u32 wret;
+	__u32 tret;
+};
+
+static void print_stack(struct key_t *key, __u64 count)
+{
+	__u64 ip[PERF_MAX_STACK_DEPTH] = {};
+	static bool warned;
+	int i;
+
+	printf("%s;", key->target);
+	if (bpf_map_lookup_elem(map_fd[1], &key->tret, ip) != 0) {
+		printf("---;");
+	} else {
+		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
+			print_ksym(ip[i]);
+	}
+	printf("-;");
+	if (bpf_map_lookup_elem(map_fd[1], &key->wret, ip) != 0) {
+		printf("---;");
+	} else {
+		for (i = 0; i < PERF_MAX_STACK_DEPTH; i++)
+			print_ksym(ip[i]);
+	}
+	printf(";%s %lld\n", key->waker, count);
+
+	if ((key->tret == -EEXIST || key->wret == -EEXIST) && !warned) {
+		printf("stackmap collisions seen. Consider increasing size\n");
+		warned = true;
+	} else if (((int)(key->tret) < 0 || (int)(key->wret) < 0)) {
+		printf("err stackid %d %d\n", key->tret, key->wret);
+	}
+}
+
+static void print_stacks(int fd)
+{
+	struct key_t key = {}, next_key;
+	__u64 value;
+
+	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
+		bpf_map_lookup_elem(fd, &next_key, &value);
+		print_stack(&next_key, value);
+		key = next_key;
+	}
+}
+
+static void int_exit(int sig)
+{
+	print_stacks(map_fd[0]);
+	exit(0);
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_object *obj = NULL;
+	struct bpf_link *links[2];
+	struct bpf_program *prog;
+	int delay = 1, i = 0;
+	char filename[256];
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	if (load_kallsyms()) {
+		printf("failed to process /proc/kallsyms\n");
+		return 2;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		obj = NULL;
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counts");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "stackmap");
+	if (map_fd[0] < 0 || map_fd[1] < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	bpf_object__for_each_program(prog, obj) {
+		links[i] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[i])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[i] = NULL;
+			goto cleanup;
+		}
+		i++;
+	}
+
+	if (argc > 1)
+		delay = atoi(argv[1]);
+	sleep(delay);
+	print_stacks(map_fd[0]);
+
+cleanup:
+	for (i--; i >= 0; i--)
+		bpf_link__destroy(links[i]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/parse_ldabs.c b/samples/bpf/parse_ldabs.c
new file mode 100644
index 000000000..c6f65f90a
--- /dev/null
+++ b/samples/bpf/parse_ldabs.c
@@ -0,0 +1,43 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+
+#define DEFAULT_PKTGEN_UDP_PORT	9
+#define IP_MF			0x2000
+#define IP_OFFSET		0x1FFF
+
+static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
+{
+	return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
+		& (IP_MF | IP_OFFSET);
+}
+
+SEC("ldabs")
+int handle_ingress(struct __sk_buff *skb)
+{
+	__u64 troff = ETH_HLEN + sizeof(struct iphdr);
+
+	if (load_half(skb, offsetof(struct ethhdr, h_proto)) != ETH_P_IP)
+		return 0;
+	if (load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol)) != IPPROTO_UDP ||
+	    load_byte(skb, ETH_HLEN) != 0x45)
+		return 0;
+	if (ip_is_fragment(skb, ETH_HLEN))
+		return 0;
+	if (load_half(skb, troff + offsetof(struct udphdr, dest)) == DEFAULT_PKTGEN_UDP_PORT)
+		return TC_ACT_SHOT;
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/parse_simple.c b/samples/bpf/parse_simple.c
new file mode 100644
index 000000000..4a486cb1e
--- /dev/null
+++ b/samples/bpf/parse_simple.c
@@ -0,0 +1,49 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <uapi/linux/bpf.h>
+#include <net/ip.h>
+#include <bpf/bpf_helpers.h>
+
+#define DEFAULT_PKTGEN_UDP_PORT 9
+
+/* copy of 'struct ethhdr' without __packed */
+struct eth_hdr {
+	unsigned char   h_dest[ETH_ALEN];
+	unsigned char   h_source[ETH_ALEN];
+	unsigned short  h_proto;
+};
+
+SEC("simple")
+int handle_ingress(struct __sk_buff *skb)
+{
+	void *data = (void *)(long)skb->data;
+	struct eth_hdr *eth = data;
+	struct iphdr *iph = data + sizeof(*eth);
+	struct udphdr *udp = data + sizeof(*eth) + sizeof(*iph);
+	void *data_end = (void *)(long)skb->data_end;
+
+	/* single length check */
+	if (data + sizeof(*eth) + sizeof(*iph) + sizeof(*udp) > data_end)
+		return 0;
+
+	if (eth->h_proto != htons(ETH_P_IP))
+		return 0;
+	if (iph->protocol != IPPROTO_UDP || iph->ihl != 5)
+		return 0;
+	if (ip_is_fragment(iph))
+		return 0;
+	if (udp->dest == htons(DEFAULT_PKTGEN_UDP_PORT))
+		return TC_ACT_SHOT;
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/parse_varlen.c b/samples/bpf/parse_varlen.c
new file mode 100644
index 000000000..d8623846e
--- /dev/null
+++ b/samples/bpf/parse_varlen.c
@@ -0,0 +1,150 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <uapi/linux/bpf.h>
+#include <net/ip.h>
+#include <bpf/bpf_helpers.h>
+
+#define DEFAULT_PKTGEN_UDP_PORT 9
+#define DEBUG 0
+
+static int tcp(void *data, uint64_t tp_off, void *data_end)
+{
+	struct tcphdr *tcp = data + tp_off;
+
+	if (tcp + 1 > data_end)
+		return 0;
+	if (tcp->dest == htons(80) || tcp->source == htons(80))
+		return TC_ACT_SHOT;
+	return 0;
+}
+
+static int udp(void *data, uint64_t tp_off, void *data_end)
+{
+	struct udphdr *udp = data + tp_off;
+
+	if (udp + 1 > data_end)
+		return 0;
+	if (udp->dest == htons(DEFAULT_PKTGEN_UDP_PORT) ||
+	    udp->source == htons(DEFAULT_PKTGEN_UDP_PORT)) {
+		if (DEBUG) {
+			char fmt[] = "udp port 9 indeed\n";
+
+			bpf_trace_printk(fmt, sizeof(fmt));
+		}
+		return TC_ACT_SHOT;
+	}
+	return 0;
+}
+
+static int parse_ipv4(void *data, uint64_t nh_off, void *data_end)
+{
+	struct iphdr *iph;
+	uint64_t ihl_len;
+
+	iph = data + nh_off;
+	if (iph + 1 > data_end)
+		return 0;
+
+	if (ip_is_fragment(iph))
+		return 0;
+	ihl_len = iph->ihl * 4;
+
+	if (iph->protocol == IPPROTO_IPIP) {
+		iph = data + nh_off + ihl_len;
+		if (iph + 1 > data_end)
+			return 0;
+		ihl_len += iph->ihl * 4;
+	}
+
+	if (iph->protocol == IPPROTO_TCP)
+		return tcp(data, nh_off + ihl_len, data_end);
+	else if (iph->protocol == IPPROTO_UDP)
+		return udp(data, nh_off + ihl_len, data_end);
+	return 0;
+}
+
+static int parse_ipv6(void *data, uint64_t nh_off, void *data_end)
+{
+	struct ipv6hdr *ip6h;
+	struct iphdr *iph;
+	uint64_t ihl_len = sizeof(struct ipv6hdr);
+	uint64_t nexthdr;
+
+	ip6h = data + nh_off;
+	if (ip6h + 1 > data_end)
+		return 0;
+
+	nexthdr = ip6h->nexthdr;
+
+	if (nexthdr == IPPROTO_IPIP) {
+		iph = data + nh_off + ihl_len;
+		if (iph + 1 > data_end)
+			return 0;
+		ihl_len += iph->ihl * 4;
+		nexthdr = iph->protocol;
+	} else if (nexthdr == IPPROTO_IPV6) {
+		ip6h = data + nh_off + ihl_len;
+		if (ip6h + 1 > data_end)
+			return 0;
+		ihl_len += sizeof(struct ipv6hdr);
+		nexthdr = ip6h->nexthdr;
+	}
+
+	if (nexthdr == IPPROTO_TCP)
+		return tcp(data, nh_off + ihl_len, data_end);
+	else if (nexthdr == IPPROTO_UDP)
+		return udp(data, nh_off + ihl_len, data_end);
+	return 0;
+}
+
+SEC("varlen")
+int handle_ingress(struct __sk_buff *skb)
+{
+	void *data = (void *)(long)skb->data;
+	struct ethhdr *eth = data;
+	void *data_end = (void *)(long)skb->data_end;
+	uint64_t h_proto, nh_off;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return 0;
+
+	h_proto = eth->h_proto;
+
+	if (h_proto == ETH_P_8021Q || h_proto == ETH_P_8021AD) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return 0;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+	if (h_proto == ETH_P_8021Q || h_proto == ETH_P_8021AD) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return 0;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+	if (h_proto == htons(ETH_P_IP))
+		return parse_ipv4(data, nh_off, data_end);
+	else if (h_proto == htons(ETH_P_IPV6))
+		return parse_ipv6(data, nh_off, data_end);
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/run_cookie_uid_helper_example.sh b/samples/bpf/run_cookie_uid_helper_example.sh
new file mode 100755
index 000000000..fc6bc0451
--- /dev/null
+++ b/samples/bpf/run_cookie_uid_helper_example.sh
@@ -0,0 +1,15 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+local_dir="$(pwd)"
+root_dir=$local_dir/../..
+mnt_dir=$(mktemp -d --tmp)
+
+on_exit() {
+	iptables -D OUTPUT -m bpf --object-pinned ${mnt_dir}/bpf_prog -j ACCEPT
+	umount ${mnt_dir}
+	rm -r ${mnt_dir}
+}
+
+trap on_exit EXIT
+mount -t bpf bpf ${mnt_dir}
+./per_socket_stats_example ${mnt_dir}/bpf_prog $1
diff --git a/samples/bpf/sampleip_kern.c b/samples/bpf/sampleip_kern.c
new file mode 100644
index 000000000..f24806ac2
--- /dev/null
+++ b/samples/bpf/sampleip_kern.c
@@ -0,0 +1,39 @@
+/* Copyright 2016 Netflix, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/version.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/bpf_perf_event.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#define MAX_IPS		8192
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u64);
+	__type(value, u32);
+	__uint(max_entries, MAX_IPS);
+} ip_map SEC(".maps");
+
+SEC("perf_event")
+int do_sample(struct bpf_perf_event_data *ctx)
+{
+	u64 ip;
+	u32 *value, init_val = 1;
+
+	ip = PT_REGS_IP(&ctx->regs);
+	value = bpf_map_lookup_elem(&ip_map, &ip);
+	if (value)
+		*value += 1;
+	else
+		/* E2BIG not tested for this example only */
+		bpf_map_update_elem(&ip_map, &ip, &init_val, BPF_NOEXIST);
+
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/sampleip_user.c b/samples/bpf/sampleip_user.c
new file mode 100644
index 000000000..921c505bb
--- /dev/null
+++ b/samples/bpf/sampleip_user.c
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * sampleip: sample instruction pointer and frequency count in a BPF map.
+ *
+ * Copyright 2016 Netflix, Inc.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <linux/perf_event.h>
+#include <linux/ptrace.h>
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "perf-sys.h"
+#include "trace_helpers.h"
+
+#define DEFAULT_FREQ	99
+#define DEFAULT_SECS	5
+#define MAX_IPS		8192
+#define PAGE_OFFSET	0xffff880000000000
+
+static int map_fd;
+static int nr_cpus;
+
+static void usage(void)
+{
+	printf("USAGE: sampleip [-F freq] [duration]\n");
+	printf("       -F freq    # sample frequency (Hertz), default 99\n");
+	printf("       duration   # sampling duration (seconds), default 5\n");
+}
+
+static int sampling_start(int freq, struct bpf_program *prog,
+			  struct bpf_link *links[])
+{
+	int i, pmu_fd;
+
+	struct perf_event_attr pe_sample_attr = {
+		.type = PERF_TYPE_SOFTWARE,
+		.freq = 1,
+		.sample_period = freq,
+		.config = PERF_COUNT_SW_CPU_CLOCK,
+		.inherit = 1,
+	};
+
+	for (i = 0; i < nr_cpus; i++) {
+		pmu_fd = sys_perf_event_open(&pe_sample_attr, -1 /* pid */, i,
+					    -1 /* group_fd */, 0 /* flags */);
+		if (pmu_fd < 0) {
+			fprintf(stderr, "ERROR: Initializing perf sampling\n");
+			return 1;
+		}
+		links[i] = bpf_program__attach_perf_event(prog, pmu_fd);
+		if (libbpf_get_error(links[i])) {
+			fprintf(stderr, "ERROR: Attach perf event\n");
+			links[i] = NULL;
+			close(pmu_fd);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+static void sampling_end(struct bpf_link *links[])
+{
+	int i;
+
+	for (i = 0; i < nr_cpus; i++)
+		bpf_link__destroy(links[i]);
+}
+
+struct ipcount {
+	__u64 ip;
+	__u32 count;
+};
+
+/* used for sorting */
+struct ipcount counts[MAX_IPS];
+
+static int count_cmp(const void *p1, const void *p2)
+{
+	return ((struct ipcount *)p1)->count - ((struct ipcount *)p2)->count;
+}
+
+static void print_ip_map(int fd)
+{
+	struct ksym *sym;
+	__u64 key, next_key;
+	__u32 value;
+	int i, max;
+
+	printf("%-19s %-32s %s\n", "ADDR", "KSYM", "COUNT");
+
+	/* fetch IPs and counts */
+	key = 0, i = 0;
+	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
+		bpf_map_lookup_elem(fd, &next_key, &value);
+		counts[i].ip = next_key;
+		counts[i++].count = value;
+		key = next_key;
+	}
+	max = i;
+
+	/* sort and print */
+	qsort(counts, max, sizeof(struct ipcount), count_cmp);
+	for (i = 0; i < max; i++) {
+		if (counts[i].ip > PAGE_OFFSET) {
+			sym = ksym_search(counts[i].ip);
+			if (!sym) {
+				printf("ksym not found. Is kallsyms loaded?\n");
+				continue;
+			}
+
+			printf("0x%-17llx %-32s %u\n", counts[i].ip, sym->name,
+			       counts[i].count);
+		} else {
+			printf("0x%-17llx %-32s %u\n", counts[i].ip, "(user)",
+			       counts[i].count);
+		}
+	}
+
+	if (max == MAX_IPS) {
+		printf("WARNING: IP hash was full (max %d entries); ", max);
+		printf("may have dropped samples\n");
+	}
+}
+
+static void int_exit(int sig)
+{
+	printf("\n");
+	print_ip_map(map_fd);
+	exit(0);
+}
+
+int main(int argc, char **argv)
+{
+	int opt, freq = DEFAULT_FREQ, secs = DEFAULT_SECS, error = 1;
+	struct bpf_object *obj = NULL;
+	struct bpf_program *prog;
+	struct bpf_link **links;
+	char filename[256];
+
+	/* process arguments */
+	while ((opt = getopt(argc, argv, "F:h")) != -1) {
+		switch (opt) {
+		case 'F':
+			freq = atoi(optarg);
+			break;
+		case 'h':
+		default:
+			usage();
+			return 0;
+		}
+	}
+	if (argc - optind == 1)
+		secs = atoi(argv[optind]);
+	if (freq == 0 || secs == 0) {
+		usage();
+		return 1;
+	}
+
+	/* initialize kernel symbol translation */
+	if (load_kallsyms()) {
+		fprintf(stderr, "ERROR: loading /proc/kallsyms\n");
+		return 2;
+	}
+
+	/* create perf FDs for each CPU */
+	nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+	links = calloc(nr_cpus, sizeof(struct bpf_link *));
+	if (!links) {
+		fprintf(stderr, "ERROR: malloc of links\n");
+		goto cleanup;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		obj = NULL;
+		goto cleanup;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "do_sample");
+	if (!prog) {
+		fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "ip_map");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	/* do sampling */
+	printf("Sampling at %d Hertz for %d seconds. Ctrl-C also ends.\n",
+	       freq, secs);
+	if (sampling_start(freq, prog, links) != 0)
+		goto cleanup;
+
+	sleep(secs);
+	error = 0;
+
+cleanup:
+	sampling_end(links);
+	/* output sample counts */
+	if (!error)
+		print_ip_map(map_fd);
+
+	free(links);
+	bpf_object__close(obj);
+	return error;
+}
diff --git a/samples/bpf/sock_example.c b/samples/bpf/sock_example.c
new file mode 100644
index 000000000..00aae1d33
--- /dev/null
+++ b/samples/bpf/sock_example.c
@@ -0,0 +1,106 @@
+/* eBPF example program:
+ * - creates arraymap in kernel with key 4 bytes and value 8 bytes
+ *
+ * - loads eBPF program:
+ *   r0 = skb->data[ETH_HLEN + offsetof(struct iphdr, protocol)];
+ *   *(u32*)(fp - 4) = r0;
+ *   // assuming packet is IPv4, lookup ip->proto in a map
+ *   value = bpf_map_lookup_elem(map_fd, fp - 4);
+ *   if (value)
+ *        (*(u64*)value) += 1;
+ *
+ * - attaches this program to loopback interface "lo" raw socket
+ *
+ * - every second user space reads map[tcp], map[udp], map[icmp] to see
+ *   how many packets of given protocol were seen on "lo"
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <assert.h>
+#include <linux/bpf.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <stddef.h>
+#include <bpf/bpf.h>
+#include "bpf_insn.h"
+#include "sock_example.h"
+
+char bpf_log_buf[BPF_LOG_BUF_SIZE];
+
+static int test_sock(void)
+{
+	int sock = -1, map_fd, prog_fd, i, key;
+	long long value = 0, tcp_cnt, udp_cnt, icmp_cnt;
+
+	map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, sizeof(key), sizeof(value),
+				256, 0);
+	if (map_fd < 0) {
+		printf("failed to create map '%s'\n", strerror(errno));
+		goto cleanup;
+	}
+
+	struct bpf_insn prog[] = {
+		BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+		BPF_LD_ABS(BPF_B, ETH_HLEN + offsetof(struct iphdr, protocol) /* R0 = ip->proto */),
+		BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */
+		BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */
+		BPF_LD_MAP_FD(BPF_REG_1, map_fd),
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
+		BPF_MOV64_IMM(BPF_REG_1, 1), /* r1 = 1 */
+		BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */
+		BPF_MOV64_IMM(BPF_REG_0, 0), /* r0 = 0 */
+		BPF_EXIT_INSN(),
+	};
+	size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
+
+	prog_fd = bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER, prog, insns_cnt,
+				   "GPL", 0, bpf_log_buf, BPF_LOG_BUF_SIZE);
+	if (prog_fd < 0) {
+		printf("failed to load prog '%s'\n", strerror(errno));
+		goto cleanup;
+	}
+
+	sock = open_raw_sock("lo");
+
+	if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd,
+		       sizeof(prog_fd)) < 0) {
+		printf("setsockopt %s\n", strerror(errno));
+		goto cleanup;
+	}
+
+	for (i = 0; i < 10; i++) {
+		key = IPPROTO_TCP;
+		assert(bpf_map_lookup_elem(map_fd, &key, &tcp_cnt) == 0);
+
+		key = IPPROTO_UDP;
+		assert(bpf_map_lookup_elem(map_fd, &key, &udp_cnt) == 0);
+
+		key = IPPROTO_ICMP;
+		assert(bpf_map_lookup_elem(map_fd, &key, &icmp_cnt) == 0);
+
+		printf("TCP %lld UDP %lld ICMP %lld packets\n",
+		       tcp_cnt, udp_cnt, icmp_cnt);
+		sleep(1);
+	}
+
+cleanup:
+	/* maps, programs, raw sockets will auto cleanup on process exit */
+	return 0;
+}
+
+int main(void)
+{
+	FILE *f;
+
+	f = popen("ping -4 -c5 localhost", "r");
+	(void)f;
+
+	return test_sock();
+}
diff --git a/samples/bpf/sock_example.h b/samples/bpf/sock_example.h
new file mode 100644
index 000000000..a27d7579b
--- /dev/null
+++ b/samples/bpf/sock_example.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <stdlib.h>
+#include <stdio.h>
+#include <linux/unistd.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <linux/if_ether.h>
+#include <net/if.h>
+#include <linux/if_packet.h>
+#include <arpa/inet.h>
+
+static inline int open_raw_sock(const char *name)
+{
+	struct sockaddr_ll sll;
+	int sock;
+
+	sock = socket(PF_PACKET, SOCK_RAW | SOCK_NONBLOCK | SOCK_CLOEXEC, htons(ETH_P_ALL));
+	if (sock < 0) {
+		printf("cannot create raw socket\n");
+		return -1;
+	}
+
+	memset(&sll, 0, sizeof(sll));
+	sll.sll_family = AF_PACKET;
+	sll.sll_ifindex = if_nametoindex(name);
+	sll.sll_protocol = htons(ETH_P_ALL);
+	if (bind(sock, (struct sockaddr *)&sll, sizeof(sll)) < 0) {
+		printf("bind to %s: %s\n", name, strerror(errno));
+		close(sock);
+		return -1;
+	}
+
+	return sock;
+}
diff --git a/samples/bpf/sock_flags_kern.c b/samples/bpf/sock_flags_kern.c
new file mode 100644
index 000000000..6d0ac7569
--- /dev/null
+++ b/samples/bpf/sock_flags_kern.c
@@ -0,0 +1,49 @@
+#include <uapi/linux/bpf.h>
+#include <linux/socket.h>
+#include <linux/net.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/in6.h>
+#include <bpf/bpf_helpers.h>
+
+SEC("cgroup/sock1")
+int bpf_prog1(struct bpf_sock *sk)
+{
+	char fmt[] = "socket: family %d type %d protocol %d\n";
+	char fmt2[] = "socket: uid %u gid %u\n";
+	__u64 gid_uid = bpf_get_current_uid_gid();
+	__u32 uid = gid_uid & 0xffffffff;
+	__u32 gid = gid_uid >> 32;
+
+	bpf_trace_printk(fmt, sizeof(fmt), sk->family, sk->type, sk->protocol);
+	bpf_trace_printk(fmt2, sizeof(fmt2), uid, gid);
+
+	/* block PF_INET6, SOCK_RAW, IPPROTO_ICMPV6 sockets
+	 * ie., make ping6 fail
+	 */
+	if (sk->family == PF_INET6 &&
+	    sk->type == SOCK_RAW   &&
+	    sk->protocol == IPPROTO_ICMPV6)
+		return 0;
+
+	return 1;
+}
+
+SEC("cgroup/sock2")
+int bpf_prog2(struct bpf_sock *sk)
+{
+	char fmt[] = "socket: family %d type %d protocol %d\n";
+
+	bpf_trace_printk(fmt, sizeof(fmt), sk->family, sk->type, sk->protocol);
+
+	/* block PF_INET, SOCK_RAW, IPPROTO_ICMP sockets
+	 * ie., make ping fail
+	 */
+	if (sk->family == PF_INET &&
+	    sk->type == SOCK_RAW  &&
+	    sk->protocol == IPPROTO_ICMP)
+		return 0;
+
+	return 1;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/sockex1_kern.c b/samples/bpf/sockex1_kern.c
new file mode 100644
index 000000000..431c95646
--- /dev/null
+++ b/samples/bpf/sockex1_kern.c
@@ -0,0 +1,30 @@
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, 256);
+} my_map SEC(".maps");
+
+SEC("socket1")
+int bpf_prog1(struct __sk_buff *skb)
+{
+	int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
+	long *value;
+
+	if (skb->pkt_type != PACKET_OUTGOING)
+		return 0;
+
+	value = bpf_map_lookup_elem(&my_map, &index);
+	if (value)
+		__sync_fetch_and_add(value, skb->len);
+
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/sockex1_user.c b/samples/bpf/sockex1_user.c
new file mode 100644
index 000000000..3c8372287
--- /dev/null
+++ b/samples/bpf/sockex1_user.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <assert.h>
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "sock_example.h"
+#include <unistd.h>
+#include <arpa/inet.h>
+
+int main(int ac, char **argv)
+{
+	struct bpf_object *obj;
+	int map_fd, prog_fd;
+	char filename[256];
+	int i, sock;
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	if (bpf_prog_load(filename, BPF_PROG_TYPE_SOCKET_FILTER,
+			  &obj, &prog_fd))
+		return 1;
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
+
+	sock = open_raw_sock("lo");
+
+	assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd,
+			  sizeof(prog_fd)) == 0);
+
+	f = popen("ping -4 -c5 localhost", "r");
+	(void) f;
+
+	for (i = 0; i < 5; i++) {
+		long long tcp_cnt, udp_cnt, icmp_cnt;
+		int key;
+
+		key = IPPROTO_TCP;
+		assert(bpf_map_lookup_elem(map_fd, &key, &tcp_cnt) == 0);
+
+		key = IPPROTO_UDP;
+		assert(bpf_map_lookup_elem(map_fd, &key, &udp_cnt) == 0);
+
+		key = IPPROTO_ICMP;
+		assert(bpf_map_lookup_elem(map_fd, &key, &icmp_cnt) == 0);
+
+		printf("TCP %lld UDP %lld ICMP %lld bytes\n",
+		       tcp_cnt, udp_cnt, icmp_cnt);
+		sleep(1);
+	}
+
+	return 0;
+}
diff --git a/samples/bpf/sockex2_kern.c b/samples/bpf/sockex2_kern.c
new file mode 100644
index 000000000..b7997541f
--- /dev/null
+++ b/samples/bpf/sockex2_kern.c
@@ -0,0 +1,223 @@
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/if.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/if_tunnel.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+#define IP_MF		0x2000
+#define IP_OFFSET	0x1FFF
+
+struct vlan_hdr {
+	__be16 h_vlan_TCI;
+	__be16 h_vlan_encapsulated_proto;
+};
+
+struct flow_key_record {
+	__be32 src;
+	__be32 dst;
+	union {
+		__be32 ports;
+		__be16 port16[2];
+	};
+	__u16 thoff;
+	__u8 ip_proto;
+};
+
+static inline int proto_ports_offset(__u64 proto)
+{
+	switch (proto) {
+	case IPPROTO_TCP:
+	case IPPROTO_UDP:
+	case IPPROTO_DCCP:
+	case IPPROTO_ESP:
+	case IPPROTO_SCTP:
+	case IPPROTO_UDPLITE:
+		return 0;
+	case IPPROTO_AH:
+		return 4;
+	default:
+		return 0;
+	}
+}
+
+static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
+{
+	return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
+		& (IP_MF | IP_OFFSET);
+}
+
+static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off)
+{
+	__u64 w0 = load_word(ctx, off);
+	__u64 w1 = load_word(ctx, off + 4);
+	__u64 w2 = load_word(ctx, off + 8);
+	__u64 w3 = load_word(ctx, off + 12);
+
+	return (__u32)(w0 ^ w1 ^ w2 ^ w3);
+}
+
+static inline __u64 parse_ip(struct __sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
+			     struct flow_key_record *flow)
+{
+	__u64 verlen;
+
+	if (unlikely(ip_is_fragment(skb, nhoff)))
+		*ip_proto = 0;
+	else
+		*ip_proto = load_byte(skb, nhoff + offsetof(struct iphdr, protocol));
+
+	if (*ip_proto != IPPROTO_GRE) {
+		flow->src = load_word(skb, nhoff + offsetof(struct iphdr, saddr));
+		flow->dst = load_word(skb, nhoff + offsetof(struct iphdr, daddr));
+	}
+
+	verlen = load_byte(skb, nhoff + 0/*offsetof(struct iphdr, ihl)*/);
+	if (likely(verlen == 0x45))
+		nhoff += 20;
+	else
+		nhoff += (verlen & 0xF) << 2;
+
+	return nhoff;
+}
+
+static inline __u64 parse_ipv6(struct __sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
+			       struct flow_key_record *flow)
+{
+	*ip_proto = load_byte(skb,
+			      nhoff + offsetof(struct ipv6hdr, nexthdr));
+	flow->src = ipv6_addr_hash(skb,
+				   nhoff + offsetof(struct ipv6hdr, saddr));
+	flow->dst = ipv6_addr_hash(skb,
+				   nhoff + offsetof(struct ipv6hdr, daddr));
+	nhoff += sizeof(struct ipv6hdr);
+
+	return nhoff;
+}
+
+static inline bool flow_dissector(struct __sk_buff *skb,
+				  struct flow_key_record *flow)
+{
+	__u64 nhoff = ETH_HLEN;
+	__u64 ip_proto;
+	__u64 proto = load_half(skb, 12);
+	int poff;
+
+	if (proto == ETH_P_8021AD) {
+		proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
+							h_vlan_encapsulated_proto));
+		nhoff += sizeof(struct vlan_hdr);
+	}
+
+	if (proto == ETH_P_8021Q) {
+		proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
+							h_vlan_encapsulated_proto));
+		nhoff += sizeof(struct vlan_hdr);
+	}
+
+	if (likely(proto == ETH_P_IP))
+		nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
+	else if (proto == ETH_P_IPV6)
+		nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
+	else
+		return false;
+
+	switch (ip_proto) {
+	case IPPROTO_GRE: {
+		struct gre_hdr {
+			__be16 flags;
+			__be16 proto;
+		};
+
+		__u64 gre_flags = load_half(skb,
+					    nhoff + offsetof(struct gre_hdr, flags));
+		__u64 gre_proto = load_half(skb,
+					    nhoff + offsetof(struct gre_hdr, proto));
+
+		if (gre_flags & (GRE_VERSION|GRE_ROUTING))
+			break;
+
+		proto = gre_proto;
+		nhoff += 4;
+		if (gre_flags & GRE_CSUM)
+			nhoff += 4;
+		if (gre_flags & GRE_KEY)
+			nhoff += 4;
+		if (gre_flags & GRE_SEQ)
+			nhoff += 4;
+
+		if (proto == ETH_P_8021Q) {
+			proto = load_half(skb,
+					  nhoff + offsetof(struct vlan_hdr,
+							   h_vlan_encapsulated_proto));
+			nhoff += sizeof(struct vlan_hdr);
+		}
+
+		if (proto == ETH_P_IP)
+			nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
+		else if (proto == ETH_P_IPV6)
+			nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
+		else
+			return false;
+		break;
+	}
+	case IPPROTO_IPIP:
+		nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
+		break;
+	case IPPROTO_IPV6:
+		nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
+		break;
+	default:
+		break;
+	}
+
+	flow->ip_proto = ip_proto;
+	poff = proto_ports_offset(ip_proto);
+	if (poff >= 0) {
+		nhoff += poff;
+		flow->ports = load_word(skb, nhoff);
+	}
+
+	flow->thoff = (__u16) nhoff;
+
+	return true;
+}
+
+struct pair {
+	long packets;
+	long bytes;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, __be32);
+	__type(value, struct pair);
+	__uint(max_entries, 1024);
+} hash_map SEC(".maps");
+
+SEC("socket2")
+int bpf_prog2(struct __sk_buff *skb)
+{
+	struct flow_key_record flow = {};
+	struct pair *value;
+	u32 key;
+
+	if (!flow_dissector(skb, &flow))
+		return 0;
+
+	key = flow.dst;
+	value = bpf_map_lookup_elem(&hash_map, &key);
+	if (value) {
+		__sync_fetch_and_add(&value->packets, 1);
+		__sync_fetch_and_add(&value->bytes, skb->len);
+	} else {
+		struct pair val = {1, skb->len};
+
+		bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
+	}
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/sockex2_user.c b/samples/bpf/sockex2_user.c
new file mode 100644
index 000000000..af925a5af
--- /dev/null
+++ b/samples/bpf/sockex2_user.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <assert.h>
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "sock_example.h"
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <sys/resource.h>
+
+struct pair {
+	__u64 packets;
+	__u64 bytes;
+};
+
+int main(int ac, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_object *obj;
+	int map_fd, prog_fd;
+	char filename[256];
+	int i, sock;
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	setrlimit(RLIMIT_MEMLOCK, &r);
+
+	if (bpf_prog_load(filename, BPF_PROG_TYPE_SOCKET_FILTER,
+			  &obj, &prog_fd))
+		return 1;
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "hash_map");
+
+	sock = open_raw_sock("lo");
+
+	assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd,
+			  sizeof(prog_fd)) == 0);
+
+	f = popen("ping -4 -c5 localhost", "r");
+	(void) f;
+
+	for (i = 0; i < 5; i++) {
+		int key = 0, next_key;
+		struct pair value;
+
+		while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
+			bpf_map_lookup_elem(map_fd, &next_key, &value);
+			printf("ip %s bytes %lld packets %lld\n",
+			       inet_ntoa((struct in_addr){htonl(next_key)}),
+			       value.bytes, value.packets);
+			key = next_key;
+		}
+		sleep(1);
+	}
+	return 0;
+}
diff --git a/samples/bpf/sockex3_kern.c b/samples/bpf/sockex3_kern.c
new file mode 100644
index 000000000..b36350335
--- /dev/null
+++ b/samples/bpf/sockex3_kern.c
@@ -0,0 +1,293 @@
+/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/if.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/if_tunnel.h>
+#include <uapi/linux/mpls.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+#define IP_MF		0x2000
+#define IP_OFFSET	0x1FFF
+
+#define PROG(F) SEC("socket/"__stringify(F)) int bpf_func_##F
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, sizeof(u32));
+	__uint(max_entries, 8);
+} jmp_table SEC(".maps");
+
+#define PARSE_VLAN 1
+#define PARSE_MPLS 2
+#define PARSE_IP 3
+#define PARSE_IPV6 4
+
+/* Protocol dispatch routine. It tail-calls next BPF program depending
+ * on eth proto. Note, we could have used ...
+ *
+ *   bpf_tail_call(skb, &jmp_table, proto);
+ *
+ * ... but it would need large prog_array and cannot be optimised given
+ * the map key is not static.
+ */
+static inline void parse_eth_proto(struct __sk_buff *skb, u32 proto)
+{
+	switch (proto) {
+	case ETH_P_8021Q:
+	case ETH_P_8021AD:
+		bpf_tail_call(skb, &jmp_table, PARSE_VLAN);
+		break;
+	case ETH_P_MPLS_UC:
+	case ETH_P_MPLS_MC:
+		bpf_tail_call(skb, &jmp_table, PARSE_MPLS);
+		break;
+	case ETH_P_IP:
+		bpf_tail_call(skb, &jmp_table, PARSE_IP);
+		break;
+	case ETH_P_IPV6:
+		bpf_tail_call(skb, &jmp_table, PARSE_IPV6);
+		break;
+	}
+}
+
+struct vlan_hdr {
+	__be16 h_vlan_TCI;
+	__be16 h_vlan_encapsulated_proto;
+};
+
+struct flow_key_record {
+	__be32 src;
+	__be32 dst;
+	union {
+		__be32 ports;
+		__be16 port16[2];
+	};
+	__u32 ip_proto;
+};
+
+static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
+{
+	return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
+		& (IP_MF | IP_OFFSET);
+}
+
+static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off)
+{
+	__u64 w0 = load_word(ctx, off);
+	__u64 w1 = load_word(ctx, off + 4);
+	__u64 w2 = load_word(ctx, off + 8);
+	__u64 w3 = load_word(ctx, off + 12);
+
+	return (__u32)(w0 ^ w1 ^ w2 ^ w3);
+}
+
+struct globals {
+	struct flow_key_record flow;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, __u32);
+	__type(value, struct globals);
+	__uint(max_entries, 32);
+} percpu_map SEC(".maps");
+
+/* user poor man's per_cpu until native support is ready */
+static struct globals *this_cpu_globals(void)
+{
+	u32 key = bpf_get_smp_processor_id();
+
+	return bpf_map_lookup_elem(&percpu_map, &key);
+}
+
+/* some simple stats for user space consumption */
+struct pair {
+	__u64 packets;
+	__u64 bytes;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, struct flow_key_record);
+	__type(value, struct pair);
+	__uint(max_entries, 1024);
+} hash_map SEC(".maps");
+
+static void update_stats(struct __sk_buff *skb, struct globals *g)
+{
+	struct flow_key_record key = g->flow;
+	struct pair *value;
+
+	value = bpf_map_lookup_elem(&hash_map, &key);
+	if (value) {
+		__sync_fetch_and_add(&value->packets, 1);
+		__sync_fetch_and_add(&value->bytes, skb->len);
+	} else {
+		struct pair val = {1, skb->len};
+
+		bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
+	}
+}
+
+static __always_inline void parse_ip_proto(struct __sk_buff *skb,
+					   struct globals *g, __u32 ip_proto)
+{
+	__u32 nhoff = skb->cb[0];
+	int poff;
+
+	switch (ip_proto) {
+	case IPPROTO_GRE: {
+		struct gre_hdr {
+			__be16 flags;
+			__be16 proto;
+		};
+
+		__u32 gre_flags = load_half(skb,
+					    nhoff + offsetof(struct gre_hdr, flags));
+		__u32 gre_proto = load_half(skb,
+					    nhoff + offsetof(struct gre_hdr, proto));
+
+		if (gre_flags & (GRE_VERSION|GRE_ROUTING))
+			break;
+
+		nhoff += 4;
+		if (gre_flags & GRE_CSUM)
+			nhoff += 4;
+		if (gre_flags & GRE_KEY)
+			nhoff += 4;
+		if (gre_flags & GRE_SEQ)
+			nhoff += 4;
+
+		skb->cb[0] = nhoff;
+		parse_eth_proto(skb, gre_proto);
+		break;
+	}
+	case IPPROTO_IPIP:
+		parse_eth_proto(skb, ETH_P_IP);
+		break;
+	case IPPROTO_IPV6:
+		parse_eth_proto(skb, ETH_P_IPV6);
+		break;
+	case IPPROTO_TCP:
+	case IPPROTO_UDP:
+		g->flow.ports = load_word(skb, nhoff);
+	case IPPROTO_ICMP:
+		g->flow.ip_proto = ip_proto;
+		update_stats(skb, g);
+		break;
+	default:
+		break;
+	}
+}
+
+PROG(PARSE_IP)(struct __sk_buff *skb)
+{
+	struct globals *g = this_cpu_globals();
+	__u32 nhoff, verlen, ip_proto;
+
+	if (!g)
+		return 0;
+
+	nhoff = skb->cb[0];
+
+	if (unlikely(ip_is_fragment(skb, nhoff)))
+		return 0;
+
+	ip_proto = load_byte(skb, nhoff + offsetof(struct iphdr, protocol));
+
+	if (ip_proto != IPPROTO_GRE) {
+		g->flow.src = load_word(skb, nhoff + offsetof(struct iphdr, saddr));
+		g->flow.dst = load_word(skb, nhoff + offsetof(struct iphdr, daddr));
+	}
+
+	verlen = load_byte(skb, nhoff + 0/*offsetof(struct iphdr, ihl)*/);
+	nhoff += (verlen & 0xF) << 2;
+
+	skb->cb[0] = nhoff;
+	parse_ip_proto(skb, g, ip_proto);
+	return 0;
+}
+
+PROG(PARSE_IPV6)(struct __sk_buff *skb)
+{
+	struct globals *g = this_cpu_globals();
+	__u32 nhoff, ip_proto;
+
+	if (!g)
+		return 0;
+
+	nhoff = skb->cb[0];
+
+	ip_proto = load_byte(skb,
+			     nhoff + offsetof(struct ipv6hdr, nexthdr));
+	g->flow.src = ipv6_addr_hash(skb,
+				     nhoff + offsetof(struct ipv6hdr, saddr));
+	g->flow.dst = ipv6_addr_hash(skb,
+				     nhoff + offsetof(struct ipv6hdr, daddr));
+	nhoff += sizeof(struct ipv6hdr);
+
+	skb->cb[0] = nhoff;
+	parse_ip_proto(skb, g, ip_proto);
+	return 0;
+}
+
+PROG(PARSE_VLAN)(struct __sk_buff *skb)
+{
+	__u32 nhoff, proto;
+
+	nhoff = skb->cb[0];
+
+	proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
+						h_vlan_encapsulated_proto));
+	nhoff += sizeof(struct vlan_hdr);
+	skb->cb[0] = nhoff;
+
+	parse_eth_proto(skb, proto);
+
+	return 0;
+}
+
+PROG(PARSE_MPLS)(struct __sk_buff *skb)
+{
+	__u32 nhoff, label;
+
+	nhoff = skb->cb[0];
+
+	label = load_word(skb, nhoff);
+	nhoff += sizeof(struct mpls_label);
+	skb->cb[0] = nhoff;
+
+	if (label & MPLS_LS_S_MASK) {
+		__u8 verlen = load_byte(skb, nhoff);
+		if ((verlen & 0xF0) == 4)
+			parse_eth_proto(skb, ETH_P_IP);
+		else
+			parse_eth_proto(skb, ETH_P_IPV6);
+	} else {
+		parse_eth_proto(skb, ETH_P_MPLS_UC);
+	}
+
+	return 0;
+}
+
+SEC("socket/0")
+int main_prog(struct __sk_buff *skb)
+{
+	__u32 nhoff = ETH_HLEN;
+	__u32 proto = load_half(skb, 12);
+
+	skb->cb[0] = nhoff;
+	parse_eth_proto(skb, proto);
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/sockex3_user.c b/samples/bpf/sockex3_user.c
new file mode 100644
index 000000000..7793f6a6a
--- /dev/null
+++ b/samples/bpf/sockex3_user.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <assert.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "sock_example.h"
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <sys/resource.h>
+
+struct flow_key_record {
+	__be32 src;
+	__be32 dst;
+	union {
+		__be32 ports;
+		__be16 port16[2];
+	};
+	__u32 ip_proto;
+};
+
+struct pair {
+	__u64 packets;
+	__u64 bytes;
+};
+
+int main(int argc, char **argv)
+{
+	int i, sock, key, fd, main_prog_fd, jmp_table_fd, hash_map_fd;
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	const char *section;
+	char filename[256];
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	setrlimit(RLIMIT_MEMLOCK, &r);
+
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	jmp_table_fd = bpf_object__find_map_fd_by_name(obj, "jmp_table");
+	hash_map_fd = bpf_object__find_map_fd_by_name(obj, "hash_map");
+	if (jmp_table_fd < 0 || hash_map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		fd = bpf_program__fd(prog);
+
+		section = bpf_program__section_name(prog);
+		if (sscanf(section, "socket/%d", &key) != 1) {
+			fprintf(stderr, "ERROR: finding prog failed\n");
+			goto cleanup;
+		}
+
+		if (key == 0)
+			main_prog_fd = fd;
+		else
+			bpf_map_update_elem(jmp_table_fd, &key, &fd, BPF_ANY);
+	}
+
+	sock = open_raw_sock("lo");
+
+	/* attach BPF program to socket */
+	assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &main_prog_fd,
+			  sizeof(__u32)) == 0);
+
+	if (argc > 1)
+		f = popen("ping -4 -c5 localhost", "r");
+	else
+		f = popen("netperf -l 4 localhost", "r");
+	(void) f;
+
+	for (i = 0; i < 5; i++) {
+		struct flow_key_record key = {}, next_key;
+		struct pair value;
+
+		sleep(1);
+		printf("IP     src.port -> dst.port               bytes      packets\n");
+		while (bpf_map_get_next_key(hash_map_fd, &key, &next_key) == 0) {
+			bpf_map_lookup_elem(hash_map_fd, &next_key, &value);
+			printf("%s.%05d -> %s.%05d %12lld %12lld\n",
+			       inet_ntoa((struct in_addr){htonl(next_key.src)}),
+			       next_key.port16[0],
+			       inet_ntoa((struct in_addr){htonl(next_key.dst)}),
+			       next_key.port16[1],
+			       value.bytes, value.packets);
+			key = next_key;
+		}
+	}
+
+cleanup:
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/spintest_kern.c b/samples/bpf/spintest_kern.c
new file mode 100644
index 000000000..455da7731
--- /dev/null
+++ b/samples/bpf/spintest_kern.c
@@ -0,0 +1,69 @@
+/* Copyright (c) 2016, Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/perf_event.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, long);
+	__type(value, long);
+	__uint(max_entries, 1024);
+} my_map SEC(".maps");
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+	__uint(key_size, sizeof(long));
+	__uint(value_size, sizeof(long));
+	__uint(max_entries, 1024);
+} my_map2 SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
+	__uint(max_entries, 10000);
+} stackmap SEC(".maps");
+
+#define PROG(foo) \
+int foo(struct pt_regs *ctx) \
+{ \
+	long v = PT_REGS_IP(ctx), *val; \
+\
+	val = bpf_map_lookup_elem(&my_map, &v); \
+	bpf_map_update_elem(&my_map, &v, &v, BPF_ANY); \
+	bpf_map_update_elem(&my_map2, &v, &v, BPF_ANY); \
+	bpf_map_delete_elem(&my_map2, &v); \
+	bpf_get_stackid(ctx, &stackmap, BPF_F_REUSE_STACKID); \
+	return 0; \
+}
+
+/* add kprobes to all possible *spin* functions */
+SEC("kprobe/spin_unlock")PROG(p1)
+SEC("kprobe/spin_lock")PROG(p2)
+SEC("kprobe/mutex_spin_on_owner")PROG(p3)
+SEC("kprobe/rwsem_spin_on_owner")PROG(p4)
+SEC("kprobe/spin_unlock_irqrestore")PROG(p5)
+SEC("kprobe/_raw_spin_unlock_irqrestore")PROG(p6)
+SEC("kprobe/_raw_spin_unlock_bh")PROG(p7)
+SEC("kprobe/_raw_spin_unlock")PROG(p8)
+SEC("kprobe/_raw_spin_lock_irqsave")PROG(p9)
+SEC("kprobe/_raw_spin_trylock_bh")PROG(p10)
+SEC("kprobe/_raw_spin_lock_irq")PROG(p11)
+SEC("kprobe/_raw_spin_trylock")PROG(p12)
+SEC("kprobe/_raw_spin_lock")PROG(p13)
+SEC("kprobe/_raw_spin_lock_bh")PROG(p14)
+/* and to inner bpf helpers */
+SEC("kprobe/htab_map_update_elem")PROG(p15)
+SEC("kprobe/__htab_percpu_map_update_elem")PROG(p16)
+SEC("kprobe/htab_map_alloc")PROG(p17)
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/spintest_user.c b/samples/bpf/spintest_user.c
new file mode 100644
index 000000000..f090d0dc6
--- /dev/null
+++ b/samples/bpf/spintest_user.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <assert.h>
+#include <sys/resource.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include "trace_helpers.h"
+
+int main(int ac, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	char filename[256], symbol[256];
+	struct bpf_object *obj = NULL;
+	struct bpf_link *links[20];
+	long key, next_key, value;
+	struct bpf_program *prog;
+	int map_fd, i, j = 0;
+	const char *section;
+	struct ksym *sym;
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	if (load_kallsyms()) {
+		printf("failed to process /proc/kallsyms\n");
+		return 2;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		obj = NULL;
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		section = bpf_program__section_name(prog);
+		if (sscanf(section, "kprobe/%s", symbol) != 1)
+			continue;
+
+		/* Attach prog only when symbol exists */
+		if (ksym_get_addr(symbol)) {
+			links[j] = bpf_program__attach(prog);
+			if (libbpf_get_error(links[j])) {
+				fprintf(stderr, "bpf_program__attach failed\n");
+				links[j] = NULL;
+				goto cleanup;
+			}
+			j++;
+		}
+	}
+
+	for (i = 0; i < 5; i++) {
+		key = 0;
+		printf("kprobing funcs:");
+		while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
+			bpf_map_lookup_elem(map_fd, &next_key, &value);
+			assert(next_key == value);
+			sym = ksym_search(value);
+			key = next_key;
+			if (!sym) {
+				printf("ksym not found. Is kallsyms loaded?\n");
+				continue;
+			}
+
+			printf(" %s", sym->name);
+		}
+		if (key)
+			printf("\n");
+		key = 0;
+		while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0)
+			bpf_map_delete_elem(map_fd, &next_key);
+		sleep(1);
+	}
+
+cleanup:
+	for (j--; j >= 0; j--)
+		bpf_link__destroy(links[j]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/syscall_nrs.c b/samples/bpf/syscall_nrs.c
new file mode 100644
index 000000000..88f940052
--- /dev/null
+++ b/samples/bpf/syscall_nrs.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <uapi/linux/unistd.h>
+#include <linux/kbuild.h>
+
+#define SYSNR(_NR) DEFINE(SYS ## _NR, _NR)
+
+void syscall_defines(void)
+{
+	COMMENT("Linux system call numbers.");
+	SYSNR(__NR_write);
+	SYSNR(__NR_read);
+#ifdef __NR_mmap2
+	SYSNR(__NR_mmap2);
+#endif
+#ifdef __NR_mmap
+	SYSNR(__NR_mmap);
+#endif
+
+}
diff --git a/samples/bpf/syscall_tp_kern.c b/samples/bpf/syscall_tp_kern.c
new file mode 100644
index 000000000..50231c2ef
--- /dev/null
+++ b/samples/bpf/syscall_tp_kern.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2017 Facebook
+ */
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+struct syscalls_enter_open_args {
+	unsigned long long unused;
+	long syscall_nr;
+	long filename_ptr;
+	long flags;
+	long mode;
+};
+
+struct syscalls_exit_open_args {
+	unsigned long long unused;
+	long syscall_nr;
+	long ret;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u32);
+	__uint(max_entries, 1);
+} enter_open_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u32);
+	__uint(max_entries, 1);
+} exit_open_map SEC(".maps");
+
+static __always_inline void count(void *map)
+{
+	u32 key = 0;
+	u32 *value, init_val = 1;
+
+	value = bpf_map_lookup_elem(map, &key);
+	if (value)
+		*value += 1;
+	else
+		bpf_map_update_elem(map, &key, &init_val, BPF_NOEXIST);
+}
+
+SEC("tracepoint/syscalls/sys_enter_open")
+int trace_enter_open(struct syscalls_enter_open_args *ctx)
+{
+	count(&enter_open_map);
+	return 0;
+}
+
+SEC("tracepoint/syscalls/sys_enter_openat")
+int trace_enter_open_at(struct syscalls_enter_open_args *ctx)
+{
+	count(&enter_open_map);
+	return 0;
+}
+
+SEC("tracepoint/syscalls/sys_exit_open")
+int trace_enter_exit(struct syscalls_exit_open_args *ctx)
+{
+	count(&exit_open_map);
+	return 0;
+}
+
+SEC("tracepoint/syscalls/sys_exit_openat")
+int trace_enter_exit_at(struct syscalls_exit_open_args *ctx)
+{
+	count(&exit_open_map);
+	return 0;
+}
diff --git a/samples/bpf/syscall_tp_user.c b/samples/bpf/syscall_tp_user.c
new file mode 100644
index 000000000..76a1d0012
--- /dev/null
+++ b/samples/bpf/syscall_tp_user.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2017 Facebook
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <linux/perf_event.h>
+#include <errno.h>
+#include <sys/resource.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+/* This program verifies bpf attachment to tracepoint sys_enter_* and sys_exit_*.
+ * This requires kernel CONFIG_FTRACE_SYSCALLS to be set.
+ */
+
+static void usage(const char *cmd)
+{
+	printf("USAGE: %s [-i num_progs] [-h]\n", cmd);
+	printf("       -i num_progs      # number of progs of the test\n");
+	printf("       -h                # help\n");
+}
+
+static void verify_map(int map_id)
+{
+	__u32 key = 0;
+	__u32 val;
+
+	if (bpf_map_lookup_elem(map_id, &key, &val) != 0) {
+		fprintf(stderr, "map_lookup failed: %s\n", strerror(errno));
+		return;
+	}
+	if (val == 0) {
+		fprintf(stderr, "failed: map #%d returns value 0\n", map_id);
+		return;
+	}
+	val = 0;
+	if (bpf_map_update_elem(map_id, &key, &val, BPF_ANY) != 0) {
+		fprintf(stderr, "map_update failed: %s\n", strerror(errno));
+		return;
+	}
+}
+
+static int test(char *filename, int num_progs)
+{
+	int map0_fds[num_progs], map1_fds[num_progs], fd, i, j = 0;
+	struct bpf_link *links[num_progs * 4];
+	struct bpf_object *objs[num_progs];
+	struct bpf_program *prog;
+
+	for (i = 0; i < num_progs; i++) {
+		objs[i] = bpf_object__open_file(filename, NULL);
+		if (libbpf_get_error(objs[i])) {
+			fprintf(stderr, "opening BPF object file failed\n");
+			objs[i] = NULL;
+			goto cleanup;
+		}
+
+		/* load BPF program */
+		if (bpf_object__load(objs[i])) {
+			fprintf(stderr, "loading BPF object file failed\n");
+			goto cleanup;
+		}
+
+		map0_fds[i] = bpf_object__find_map_fd_by_name(objs[i],
+							      "enter_open_map");
+		map1_fds[i] = bpf_object__find_map_fd_by_name(objs[i],
+							      "exit_open_map");
+		if (map0_fds[i] < 0 || map1_fds[i] < 0) {
+			fprintf(stderr, "finding a map in obj file failed\n");
+			goto cleanup;
+		}
+
+		bpf_object__for_each_program(prog, objs[i]) {
+			links[j] = bpf_program__attach(prog);
+			if (libbpf_get_error(links[j])) {
+				fprintf(stderr, "bpf_program__attach failed\n");
+				links[j] = NULL;
+				goto cleanup;
+			}
+			j++;
+		}
+		printf("prog #%d: map ids %d %d\n", i, map0_fds[i], map1_fds[i]);
+	}
+
+	/* current load_bpf_file has perf_event_open default pid = -1
+	 * and cpu = 0, which permits attached bpf execution on
+	 * all cpus for all pid's. bpf program execution ignores
+	 * cpu affinity.
+	 */
+	/* trigger some "open" operations */
+	fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "open failed: %s\n", strerror(errno));
+		return 1;
+	}
+	close(fd);
+
+	/* verify the map */
+	for (i = 0; i < num_progs; i++) {
+		verify_map(map0_fds[i]);
+		verify_map(map1_fds[i]);
+	}
+
+cleanup:
+	for (j--; j >= 0; j--)
+		bpf_link__destroy(links[j]);
+
+	for (i--; i >= 0; i--)
+		bpf_object__close(objs[i]);
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	int opt, num_progs = 1;
+	char filename[256];
+
+	while ((opt = getopt(argc, argv, "i:h")) != -1) {
+		switch (opt) {
+		case 'i':
+			num_progs = atoi(optarg);
+			break;
+		case 'h':
+		default:
+			usage(argv[0]);
+			return 0;
+		}
+	}
+
+	setrlimit(RLIMIT_MEMLOCK, &r);
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	return test(filename, num_progs);
+}
diff --git a/samples/bpf/task_fd_query_kern.c b/samples/bpf/task_fd_query_kern.c
new file mode 100644
index 000000000..c821294e1
--- /dev/null
+++ b/samples/bpf/task_fd_query_kern.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/version.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+SEC("kprobe/blk_mq_start_request")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	return 0;
+}
+
+SEC("kretprobe/blk_account_io_done")
+int bpf_prog2(struct pt_regs *ctx)
+{
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/task_fd_query_user.c b/samples/bpf/task_fd_query_user.c
new file mode 100644
index 000000000..b68bd2f8f
--- /dev/null
+++ b/samples/bpf/task_fd_query_user.c
@@ -0,0 +1,383 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <string.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <linux/bpf.h>
+#include <sys/ioctl.h>
+#include <sys/resource.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <linux/perf_event.h>
+
+#include <bpf/libbpf.h>
+#include "bpf_load.h"
+#include "bpf_util.h"
+#include "perf-sys.h"
+#include "trace_helpers.h"
+
+#define CHECK_PERROR_RET(condition) ({			\
+	int __ret = !!(condition);			\
+	if (__ret) {					\
+		printf("FAIL: %s:\n", __func__);	\
+		perror("    ");			\
+		return -1;				\
+	}						\
+})
+
+#define CHECK_AND_RET(condition) ({			\
+	int __ret = !!(condition);			\
+	if (__ret)					\
+		return -1;				\
+})
+
+static __u64 ptr_to_u64(void *ptr)
+{
+	return (__u64) (unsigned long) ptr;
+}
+
+#define PMU_TYPE_FILE "/sys/bus/event_source/devices/%s/type"
+static int bpf_find_probe_type(const char *event_type)
+{
+	char buf[256];
+	int fd, ret;
+
+	ret = snprintf(buf, sizeof(buf), PMU_TYPE_FILE, event_type);
+	CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
+
+	fd = open(buf, O_RDONLY);
+	CHECK_PERROR_RET(fd < 0);
+
+	ret = read(fd, buf, sizeof(buf));
+	close(fd);
+	CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
+
+	errno = 0;
+	ret = (int)strtol(buf, NULL, 10);
+	CHECK_PERROR_RET(errno);
+	return ret;
+}
+
+#define PMU_RETPROBE_FILE "/sys/bus/event_source/devices/%s/format/retprobe"
+static int bpf_get_retprobe_bit(const char *event_type)
+{
+	char buf[256];
+	int fd, ret;
+
+	ret = snprintf(buf, sizeof(buf), PMU_RETPROBE_FILE, event_type);
+	CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
+
+	fd = open(buf, O_RDONLY);
+	CHECK_PERROR_RET(fd < 0);
+
+	ret = read(fd, buf, sizeof(buf));
+	close(fd);
+	CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
+	CHECK_PERROR_RET(strlen(buf) < strlen("config:"));
+
+	errno = 0;
+	ret = (int)strtol(buf + strlen("config:"), NULL, 10);
+	CHECK_PERROR_RET(errno);
+	return ret;
+}
+
+static int test_debug_fs_kprobe(int prog_fd_idx, const char *fn_name,
+				__u32 expected_fd_type)
+{
+	__u64 probe_offset, probe_addr;
+	__u32 len, prog_id, fd_type;
+	char buf[256];
+	int err;
+
+	len = sizeof(buf);
+	err = bpf_task_fd_query(getpid(), event_fd[prog_fd_idx], 0, buf, &len,
+				&prog_id, &fd_type, &probe_offset,
+				&probe_addr);
+	if (err < 0) {
+		printf("FAIL: %s, for event_fd idx %d, fn_name %s\n",
+		       __func__, prog_fd_idx, fn_name);
+		perror("    :");
+		return -1;
+	}
+	if (strcmp(buf, fn_name) != 0 ||
+	    fd_type != expected_fd_type ||
+	    probe_offset != 0x0 || probe_addr != 0x0) {
+		printf("FAIL: bpf_trace_event_query(event_fd[%d]):\n",
+		       prog_fd_idx);
+		printf("buf: %s, fd_type: %u, probe_offset: 0x%llx,"
+		       " probe_addr: 0x%llx\n",
+		       buf, fd_type, probe_offset, probe_addr);
+		return -1;
+	}
+	return 0;
+}
+
+static int test_nondebug_fs_kuprobe_common(const char *event_type,
+	const char *name, __u64 offset, __u64 addr, bool is_return,
+	char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type,
+	__u64 *probe_offset, __u64 *probe_addr)
+{
+	int is_return_bit = bpf_get_retprobe_bit(event_type);
+	int type = bpf_find_probe_type(event_type);
+	struct perf_event_attr attr = {};
+	int fd;
+
+	if (type < 0 || is_return_bit < 0) {
+		printf("FAIL: %s incorrect type (%d) or is_return_bit (%d)\n",
+			__func__, type, is_return_bit);
+		return -1;
+	}
+
+	attr.sample_period = 1;
+	attr.wakeup_events = 1;
+	if (is_return)
+		attr.config |= 1 << is_return_bit;
+
+	if (name) {
+		attr.config1 = ptr_to_u64((void *)name);
+		attr.config2 = offset;
+	} else {
+		attr.config1 = 0;
+		attr.config2 = addr;
+	}
+	attr.size = sizeof(attr);
+	attr.type = type;
+
+	fd = sys_perf_event_open(&attr, -1, 0, -1, 0);
+	CHECK_PERROR_RET(fd < 0);
+
+	CHECK_PERROR_RET(ioctl(fd, PERF_EVENT_IOC_ENABLE, 0) < 0);
+	CHECK_PERROR_RET(ioctl(fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) < 0);
+	CHECK_PERROR_RET(bpf_task_fd_query(getpid(), fd, 0, buf, buf_len,
+			 prog_id, fd_type, probe_offset, probe_addr) < 0);
+
+	return 0;
+}
+
+static int test_nondebug_fs_probe(const char *event_type, const char *name,
+				  __u64 offset, __u64 addr, bool is_return,
+				  __u32 expected_fd_type,
+				  __u32 expected_ret_fd_type,
+				  char *buf, __u32 buf_len)
+{
+	__u64 probe_offset, probe_addr;
+	__u32 prog_id, fd_type;
+	int err;
+
+	err = test_nondebug_fs_kuprobe_common(event_type, name,
+					      offset, addr, is_return,
+					      buf, &buf_len, &prog_id,
+					      &fd_type, &probe_offset,
+					      &probe_addr);
+	if (err < 0) {
+		printf("FAIL: %s, "
+		       "for name %s, offset 0x%llx, addr 0x%llx, is_return %d\n",
+		       __func__, name ? name : "", offset, addr, is_return);
+		perror("    :");
+		return -1;
+	}
+	if ((is_return && fd_type != expected_ret_fd_type) ||
+	    (!is_return && fd_type != expected_fd_type)) {
+		printf("FAIL: %s, incorrect fd_type %u\n",
+		       __func__, fd_type);
+		return -1;
+	}
+	if (name) {
+		if (strcmp(name, buf) != 0) {
+			printf("FAIL: %s, incorrect buf %s\n", __func__, buf);
+			return -1;
+		}
+		if (probe_offset != offset) {
+			printf("FAIL: %s, incorrect probe_offset 0x%llx\n",
+			       __func__, probe_offset);
+			return -1;
+		}
+	} else {
+		if (buf_len != 0) {
+			printf("FAIL: %s, incorrect buf %p\n",
+			       __func__, buf);
+			return -1;
+		}
+
+		if (probe_addr != addr) {
+			printf("FAIL: %s, incorrect probe_addr 0x%llx\n",
+			       __func__, probe_addr);
+			return -1;
+		}
+	}
+	return 0;
+}
+
+static int test_debug_fs_uprobe(char *binary_path, long offset, bool is_return)
+{
+	const char *event_type = "uprobe";
+	struct perf_event_attr attr = {};
+	char buf[256], event_alias[sizeof("test_1234567890")];
+	__u64 probe_offset, probe_addr;
+	__u32 len, prog_id, fd_type;
+	int err, res, kfd, efd;
+	ssize_t bytes;
+
+	snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/%s_events",
+		 event_type);
+	kfd = open(buf, O_WRONLY | O_APPEND, 0);
+	CHECK_PERROR_RET(kfd < 0);
+
+	res = snprintf(event_alias, sizeof(event_alias), "test_%d", getpid());
+	CHECK_PERROR_RET(res < 0 || res >= sizeof(event_alias));
+
+	res = snprintf(buf, sizeof(buf), "%c:%ss/%s %s:0x%lx",
+		       is_return ? 'r' : 'p', event_type, event_alias,
+		       binary_path, offset);
+	CHECK_PERROR_RET(res < 0 || res >= sizeof(buf));
+	CHECK_PERROR_RET(write(kfd, buf, strlen(buf)) < 0);
+
+	close(kfd);
+	kfd = -1;
+
+	snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s/id",
+		 event_type, event_alias);
+	efd = open(buf, O_RDONLY, 0);
+	CHECK_PERROR_RET(efd < 0);
+
+	bytes = read(efd, buf, sizeof(buf));
+	CHECK_PERROR_RET(bytes <= 0 || bytes >= sizeof(buf));
+	close(efd);
+	buf[bytes] = '\0';
+
+	attr.config = strtol(buf, NULL, 0);
+	attr.type = PERF_TYPE_TRACEPOINT;
+	attr.sample_period = 1;
+	attr.wakeup_events = 1;
+	kfd = sys_perf_event_open(&attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);
+	CHECK_PERROR_RET(kfd < 0);
+	CHECK_PERROR_RET(ioctl(kfd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) < 0);
+	CHECK_PERROR_RET(ioctl(kfd, PERF_EVENT_IOC_ENABLE, 0) < 0);
+
+	len = sizeof(buf);
+	err = bpf_task_fd_query(getpid(), kfd, 0, buf, &len,
+				&prog_id, &fd_type, &probe_offset,
+				&probe_addr);
+	if (err < 0) {
+		printf("FAIL: %s, binary_path %s\n", __func__, binary_path);
+		perror("    :");
+		return -1;
+	}
+	if ((is_return && fd_type != BPF_FD_TYPE_URETPROBE) ||
+	    (!is_return && fd_type != BPF_FD_TYPE_UPROBE)) {
+		printf("FAIL: %s, incorrect fd_type %u\n", __func__,
+		       fd_type);
+		return -1;
+	}
+	if (strcmp(binary_path, buf) != 0) {
+		printf("FAIL: %s, incorrect buf %s\n", __func__, buf);
+		return -1;
+	}
+	if (probe_offset != offset) {
+		printf("FAIL: %s, incorrect probe_offset 0x%llx\n", __func__,
+		       probe_offset);
+		return -1;
+	}
+
+	close(kfd);
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	extern char __executable_start;
+	char filename[256], buf[256];
+	__u64 uprobe_file_offset;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	if (load_kallsyms()) {
+		printf("failed to process /proc/kallsyms\n");
+		return 1;
+	}
+
+	if (load_bpf_file(filename)) {
+		printf("%s", bpf_log_buf);
+		return 1;
+	}
+
+	/* test two functions in the corresponding *_kern.c file */
+	CHECK_AND_RET(test_debug_fs_kprobe(0, "blk_mq_start_request",
+					   BPF_FD_TYPE_KPROBE));
+	CHECK_AND_RET(test_debug_fs_kprobe(1, "blk_account_io_done",
+					   BPF_FD_TYPE_KRETPROBE));
+
+	/* test nondebug fs kprobe */
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0,
+					     false, BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     buf, sizeof(buf)));
+#ifdef __x86_64__
+	/* set a kprobe on "bpf_check + 0x5", which is x64 specific */
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x5, 0x0,
+					     false, BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     buf, sizeof(buf)));
+#endif
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0,
+					     true, BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     buf, sizeof(buf)));
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
+					     ksym_get_addr("bpf_check"), false,
+					     BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     buf, sizeof(buf)));
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
+					     ksym_get_addr("bpf_check"), false,
+					     BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     NULL, 0));
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
+					     ksym_get_addr("bpf_check"), true,
+					     BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     buf, sizeof(buf)));
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
+					     ksym_get_addr("bpf_check"), true,
+					     BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     0, 0));
+
+	/* test nondebug fs uprobe */
+	/* the calculation of uprobe file offset is based on gcc 7.3.1 on x64
+	 * and the default linker script, which defines __executable_start as
+	 * the start of the .text section. The calculation could be different
+	 * on different systems with different compilers. The right way is
+	 * to parse the ELF file. We took a shortcut here.
+	 */
+	uprobe_file_offset = (__u64)main - (__u64)&__executable_start;
+	CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0],
+					     uprobe_file_offset, 0x0, false,
+					     BPF_FD_TYPE_UPROBE,
+					     BPF_FD_TYPE_URETPROBE,
+					     buf, sizeof(buf)));
+	CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0],
+					     uprobe_file_offset, 0x0, true,
+					     BPF_FD_TYPE_UPROBE,
+					     BPF_FD_TYPE_URETPROBE,
+					     buf, sizeof(buf)));
+
+	/* test debug fs uprobe */
+	CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset,
+					   false));
+	CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset,
+					   true));
+
+	return 0;
+}
diff --git a/samples/bpf/tc_l2_redirect.sh b/samples/bpf/tc_l2_redirect.sh
new file mode 100755
index 000000000..37d95ef3c
--- /dev/null
+++ b/samples/bpf/tc_l2_redirect.sh
@@ -0,0 +1,174 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+[[ -z $TC ]] && TC='tc'
+[[ -z $IP ]] && IP='ip'
+
+REDIRECT_USER='./tc_l2_redirect'
+REDIRECT_BPF='./tc_l2_redirect_kern.o'
+
+RP_FILTER=$(< /proc/sys/net/ipv4/conf/all/rp_filter)
+IPV6_FORWARDING=$(< /proc/sys/net/ipv6/conf/all/forwarding)
+
+function config_common {
+	local tun_type=$1
+
+	$IP netns add ns1
+	$IP netns add ns2
+	$IP link add ve1 type veth peer name vens1
+	$IP link add ve2 type veth peer name vens2
+	$IP link set dev ve1 up
+	$IP link set dev ve2 up
+	$IP link set dev ve1 mtu 1500
+	$IP link set dev ve2 mtu 1500
+	$IP link set dev vens1 netns ns1
+	$IP link set dev vens2 netns ns2
+
+	$IP -n ns1 link set dev lo up
+	$IP -n ns1 link set dev vens1 up
+	$IP -n ns1 addr add 10.1.1.101/24 dev vens1
+	$IP -n ns1 addr add 2401:db01::65/64 dev vens1 nodad
+	$IP -n ns1 route add default via 10.1.1.1 dev vens1
+	$IP -n ns1 route add default via 2401:db01::1 dev vens1
+
+	$IP -n ns2 link set dev lo up
+	$IP -n ns2 link set dev vens2 up
+	$IP -n ns2 addr add 10.2.1.102/24 dev vens2
+	$IP -n ns2 addr add 2401:db02::66/64 dev vens2 nodad
+	$IP -n ns2 addr add 10.10.1.102 dev lo
+	$IP -n ns2 addr add 2401:face::66/64 dev lo nodad
+	$IP -n ns2 link add ipt2 type ipip local 10.2.1.102 remote 10.2.1.1
+	$IP -n ns2 link add ip6t2 type ip6tnl mode any local 2401:db02::66 remote 2401:db02::1
+	$IP -n ns2 link set dev ipt2 up
+	$IP -n ns2 link set dev ip6t2 up
+	$IP netns exec ns2 $TC qdisc add dev vens2 clsact
+	$IP netns exec ns2 $TC filter add dev vens2 ingress bpf da obj $REDIRECT_BPF sec drop_non_tun_vip
+	if [[ $tun_type == "ipip" ]]; then
+		$IP -n ns2 route add 10.1.1.0/24 dev ipt2
+		$IP netns exec ns2 sysctl -q -w net.ipv4.conf.all.rp_filter=0
+		$IP netns exec ns2 sysctl -q -w net.ipv4.conf.ipt2.rp_filter=0
+	else
+		$IP -n ns2 route add 10.1.1.0/24 dev ip6t2
+		$IP -n ns2 route add 2401:db01::/64 dev ip6t2
+		$IP netns exec ns2 sysctl -q -w net.ipv4.conf.all.rp_filter=0
+		$IP netns exec ns2 sysctl -q -w net.ipv4.conf.ip6t2.rp_filter=0
+	fi
+
+	$IP addr add 10.1.1.1/24 dev ve1
+	$IP addr add 2401:db01::1/64 dev ve1 nodad
+	$IP addr add 10.2.1.1/24 dev ve2
+	$IP addr add 2401:db02::1/64 dev ve2 nodad
+
+	$TC qdisc add dev ve2 clsact
+	$TC filter add dev ve2 ingress bpf da obj $REDIRECT_BPF sec l2_to_iptun_ingress_forward
+
+	sysctl -q -w net.ipv4.conf.all.rp_filter=0
+	sysctl -q -w net.ipv6.conf.all.forwarding=1
+}
+
+function cleanup {
+	set +e
+	[[ -z $DEBUG ]] || set +x
+	$IP netns delete ns1 >& /dev/null
+	$IP netns delete ns2 >& /dev/null
+	$IP link del ve1 >& /dev/null
+	$IP link del ve2 >& /dev/null
+	$IP link del ipt >& /dev/null
+	$IP link del ip6t >& /dev/null
+	sysctl -q -w net.ipv4.conf.all.rp_filter=$RP_FILTER
+	sysctl -q -w net.ipv6.conf.all.forwarding=$IPV6_FORWARDING
+	rm -f /sys/fs/bpf/tc/globals/tun_iface
+	[[ -z $DEBUG ]] || set -x
+	set -e
+}
+
+function l2_to_ipip {
+	echo -n "l2_to_ipip $1: "
+
+	local dir=$1
+
+	config_common ipip
+
+	$IP link add ipt type ipip external
+	$IP link set dev ipt up
+	sysctl -q -w net.ipv4.conf.ipt.rp_filter=0
+	sysctl -q -w net.ipv4.conf.ipt.forwarding=1
+
+	if [[ $dir == "egress" ]]; then
+		$IP route add 10.10.1.0/24 via 10.2.1.102 dev ve2
+		$TC filter add dev ve2 egress bpf da obj $REDIRECT_BPF sec l2_to_iptun_ingress_redirect
+		sysctl -q -w net.ipv4.conf.ve1.forwarding=1
+	else
+		$TC qdisc add dev ve1 clsact
+		$TC filter add dev ve1 ingress bpf da obj $REDIRECT_BPF sec l2_to_iptun_ingress_redirect
+	fi
+
+	$REDIRECT_USER -U /sys/fs/bpf/tc/globals/tun_iface -i $(< /sys/class/net/ipt/ifindex)
+
+	$IP netns exec ns1 ping -c1 10.10.1.102 >& /dev/null
+
+	if [[ $dir == "egress" ]]; then
+		# test direct egress to ve2 (i.e. not forwarding from
+		# ve1 to ve2).
+		ping -c1 10.10.1.102 >& /dev/null
+	fi
+
+	cleanup
+
+	echo "OK"
+}
+
+function l2_to_ip6tnl {
+	echo -n "l2_to_ip6tnl $1: "
+
+	local dir=$1
+
+	config_common ip6tnl
+
+	$IP link add ip6t type ip6tnl mode any external
+	$IP link set dev ip6t up
+	sysctl -q -w net.ipv4.conf.ip6t.rp_filter=0
+	sysctl -q -w net.ipv4.conf.ip6t.forwarding=1
+
+	if [[ $dir == "egress" ]]; then
+		$IP route add 10.10.1.0/24 via 10.2.1.102 dev ve2
+		$IP route add 2401:face::/64 via 2401:db02::66 dev ve2
+		$TC filter add dev ve2 egress bpf da obj $REDIRECT_BPF sec l2_to_ip6tun_ingress_redirect
+		sysctl -q -w net.ipv4.conf.ve1.forwarding=1
+	else
+		$TC qdisc add dev ve1 clsact
+		$TC filter add dev ve1 ingress bpf da obj $REDIRECT_BPF sec l2_to_ip6tun_ingress_redirect
+	fi
+
+	$REDIRECT_USER -U /sys/fs/bpf/tc/globals/tun_iface -i $(< /sys/class/net/ip6t/ifindex)
+
+	$IP netns exec ns1 ping -c1 10.10.1.102 >& /dev/null
+	$IP netns exec ns1 ping -6 -c1 2401:face::66 >& /dev/null
+
+	if [[ $dir == "egress" ]]; then
+		# test direct egress to ve2 (i.e. not forwarding from
+		# ve1 to ve2).
+		ping -c1 10.10.1.102 >& /dev/null
+		ping -6 -c1 2401:face::66 >& /dev/null
+	fi
+
+	cleanup
+
+	echo "OK"
+}
+
+cleanup
+test_names="l2_to_ipip l2_to_ip6tnl"
+test_dirs="ingress egress"
+if [[ $# -ge 2 ]]; then
+	test_names=$1
+	test_dirs=$2
+elif [[ $# -ge 1 ]]; then
+	test_names=$1
+fi
+
+for t in $test_names; do
+	for d in $test_dirs; do
+		$t $d
+	done
+done
diff --git a/samples/bpf/tc_l2_redirect_kern.c b/samples/bpf/tc_l2_redirect_kern.c
new file mode 100644
index 000000000..fd2fa0004
--- /dev/null
+++ b/samples/bpf/tc_l2_redirect_kern.c
@@ -0,0 +1,237 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/filter.h>
+#include <uapi/linux/pkt_cls.h>
+#include <net/ipv6.h>
+#include <bpf/bpf_helpers.h>
+
+#define _htonl __builtin_bswap32
+
+#define PIN_GLOBAL_NS		2
+struct bpf_elf_map {
+	__u32 type;
+	__u32 size_key;
+	__u32 size_value;
+	__u32 max_elem;
+	__u32 flags;
+	__u32 id;
+	__u32 pinning;
+};
+
+/* copy of 'struct ethhdr' without __packed */
+struct eth_hdr {
+	unsigned char   h_dest[ETH_ALEN];
+	unsigned char   h_source[ETH_ALEN];
+	unsigned short  h_proto;
+};
+
+struct bpf_elf_map SEC("maps") tun_iface = {
+	.type = BPF_MAP_TYPE_ARRAY,
+	.size_key = sizeof(int),
+	.size_value = sizeof(int),
+	.pinning = PIN_GLOBAL_NS,
+	.max_elem = 1,
+};
+
+static __always_inline bool is_vip_addr(__be16 eth_proto, __be32 daddr)
+{
+	if (eth_proto == htons(ETH_P_IP))
+		return (_htonl(0xffffff00) & daddr) == _htonl(0x0a0a0100);
+	else if (eth_proto == htons(ETH_P_IPV6))
+		return (daddr == _htonl(0x2401face));
+
+	return false;
+}
+
+SEC("l2_to_iptun_ingress_forward")
+int _l2_to_iptun_ingress_forward(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key tkey = {};
+	void *data = (void *)(long)skb->data;
+	struct eth_hdr *eth = data;
+	void *data_end = (void *)(long)skb->data_end;
+	int key = 0, *ifindex;
+
+	int ret;
+
+	if (data + sizeof(*eth) > data_end)
+		return TC_ACT_OK;
+
+	ifindex = bpf_map_lookup_elem(&tun_iface, &key);
+	if (!ifindex)
+		return TC_ACT_OK;
+
+	if (eth->h_proto == htons(ETH_P_IP)) {
+		char fmt4[] = "ingress forward to ifindex:%d daddr4:%x\n";
+		struct iphdr *iph = data + sizeof(*eth);
+
+		if (data + sizeof(*eth) + sizeof(*iph) > data_end)
+			return TC_ACT_OK;
+
+		if (iph->protocol != IPPROTO_IPIP)
+			return TC_ACT_OK;
+
+		bpf_trace_printk(fmt4, sizeof(fmt4), *ifindex,
+				 _htonl(iph->daddr));
+		return bpf_redirect(*ifindex, BPF_F_INGRESS);
+	} else if (eth->h_proto == htons(ETH_P_IPV6)) {
+		char fmt6[] = "ingress forward to ifindex:%d daddr6:%x::%x\n";
+		struct ipv6hdr *ip6h = data + sizeof(*eth);
+
+		if (data + sizeof(*eth) + sizeof(*ip6h) > data_end)
+			return TC_ACT_OK;
+
+		if (ip6h->nexthdr != IPPROTO_IPIP &&
+		    ip6h->nexthdr != IPPROTO_IPV6)
+			return TC_ACT_OK;
+
+		bpf_trace_printk(fmt6, sizeof(fmt6), *ifindex,
+				 _htonl(ip6h->daddr.s6_addr32[0]),
+				 _htonl(ip6h->daddr.s6_addr32[3]));
+		return bpf_redirect(*ifindex, BPF_F_INGRESS);
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("l2_to_iptun_ingress_redirect")
+int _l2_to_iptun_ingress_redirect(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key tkey = {};
+	void *data = (void *)(long)skb->data;
+	struct eth_hdr *eth = data;
+	void *data_end = (void *)(long)skb->data_end;
+	int key = 0, *ifindex;
+
+	int ret;
+
+	if (data + sizeof(*eth) > data_end)
+		return TC_ACT_OK;
+
+	ifindex = bpf_map_lookup_elem(&tun_iface, &key);
+	if (!ifindex)
+		return TC_ACT_OK;
+
+	if (eth->h_proto == htons(ETH_P_IP)) {
+		char fmt4[] = "e/ingress redirect daddr4:%x to ifindex:%d\n";
+		struct iphdr *iph = data + sizeof(*eth);
+		__be32 daddr = iph->daddr;
+
+		if (data + sizeof(*eth) + sizeof(*iph) > data_end)
+			return TC_ACT_OK;
+
+		if (!is_vip_addr(eth->h_proto, daddr))
+			return TC_ACT_OK;
+
+		bpf_trace_printk(fmt4, sizeof(fmt4), _htonl(daddr), *ifindex);
+	} else {
+		return TC_ACT_OK;
+	}
+
+	tkey.tunnel_id = 10000;
+	tkey.tunnel_ttl = 64;
+	tkey.remote_ipv4 = 0x0a020166; /* 10.2.1.102 */
+	bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), 0);
+	return bpf_redirect(*ifindex, 0);
+}
+
+SEC("l2_to_ip6tun_ingress_redirect")
+int _l2_to_ip6tun_ingress_redirect(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key tkey = {};
+	void *data = (void *)(long)skb->data;
+	struct eth_hdr *eth = data;
+	void *data_end = (void *)(long)skb->data_end;
+	int key = 0, *ifindex;
+
+	if (data + sizeof(*eth) > data_end)
+		return TC_ACT_OK;
+
+	ifindex = bpf_map_lookup_elem(&tun_iface, &key);
+	if (!ifindex)
+		return TC_ACT_OK;
+
+	if (eth->h_proto == htons(ETH_P_IP)) {
+		char fmt4[] = "e/ingress redirect daddr4:%x to ifindex:%d\n";
+		struct iphdr *iph = data + sizeof(*eth);
+
+		if (data + sizeof(*eth) + sizeof(*iph) > data_end)
+			return TC_ACT_OK;
+
+		if (!is_vip_addr(eth->h_proto, iph->daddr))
+			return TC_ACT_OK;
+
+		bpf_trace_printk(fmt4, sizeof(fmt4), _htonl(iph->daddr),
+				 *ifindex);
+	} else if (eth->h_proto == htons(ETH_P_IPV6)) {
+		char fmt6[] = "e/ingress redirect daddr6:%x to ifindex:%d\n";
+		struct ipv6hdr *ip6h = data + sizeof(*eth);
+
+		if (data + sizeof(*eth) + sizeof(*ip6h) > data_end)
+			return TC_ACT_OK;
+
+		if (!is_vip_addr(eth->h_proto, ip6h->daddr.s6_addr32[0]))
+			return TC_ACT_OK;
+
+		bpf_trace_printk(fmt6, sizeof(fmt6),
+				 _htonl(ip6h->daddr.s6_addr32[0]), *ifindex);
+	} else {
+		return TC_ACT_OK;
+	}
+
+	tkey.tunnel_id = 10000;
+	tkey.tunnel_ttl = 64;
+	/* 2401:db02:0:0:0:0:0:66 */
+	tkey.remote_ipv6[0] = _htonl(0x2401db02);
+	tkey.remote_ipv6[1] = 0;
+	tkey.remote_ipv6[2] = 0;
+	tkey.remote_ipv6[3] = _htonl(0x00000066);
+	bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), BPF_F_TUNINFO_IPV6);
+	return bpf_redirect(*ifindex, 0);
+}
+
+SEC("drop_non_tun_vip")
+int _drop_non_tun_vip(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key tkey = {};
+	void *data = (void *)(long)skb->data;
+	struct eth_hdr *eth = data;
+	void *data_end = (void *)(long)skb->data_end;
+
+	if (data + sizeof(*eth) > data_end)
+		return TC_ACT_OK;
+
+	if (eth->h_proto == htons(ETH_P_IP)) {
+		struct iphdr *iph = data + sizeof(*eth);
+
+		if (data + sizeof(*eth) + sizeof(*iph) > data_end)
+			return TC_ACT_OK;
+
+		if (is_vip_addr(eth->h_proto, iph->daddr))
+			return TC_ACT_SHOT;
+	} else if (eth->h_proto == htons(ETH_P_IPV6)) {
+		struct ipv6hdr *ip6h = data + sizeof(*eth);
+
+		if (data + sizeof(*eth) + sizeof(*ip6h) > data_end)
+			return TC_ACT_OK;
+
+		if (is_vip_addr(eth->h_proto, ip6h->daddr.s6_addr32[0]))
+			return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tc_l2_redirect_user.c b/samples/bpf/tc_l2_redirect_user.c
new file mode 100644
index 000000000..d11a6e1e9
--- /dev/null
+++ b/samples/bpf/tc_l2_redirect_user.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include <linux/unistd.h>
+#include <linux/bpf.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#include <bpf/bpf.h>
+
+static void usage(void)
+{
+	printf("Usage: tc_l2_ipip_redirect [...]\n");
+	printf("       -U <file>   Update an already pinned BPF array\n");
+	printf("       -i <ifindex> Interface index\n");
+	printf("       -h          Display this help\n");
+}
+
+int main(int argc, char **argv)
+{
+	const char *pinned_file = NULL;
+	int ifindex = -1;
+	int array_key = 0;
+	int array_fd = -1;
+	int ret = -1;
+	int opt;
+
+	while ((opt = getopt(argc, argv, "F:U:i:")) != -1) {
+		switch (opt) {
+		/* General args */
+		case 'U':
+			pinned_file = optarg;
+			break;
+		case 'i':
+			ifindex = atoi(optarg);
+			break;
+		default:
+			usage();
+			goto out;
+		}
+	}
+
+	if (ifindex < 0 || !pinned_file) {
+		usage();
+		goto out;
+	}
+
+	array_fd = bpf_obj_get(pinned_file);
+	if (array_fd < 0) {
+		fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
+			pinned_file, strerror(errno), errno);
+		goto out;
+	}
+
+	/* bpf_tunnel_key.remote_ipv4 expects host byte orders */
+	ret = bpf_map_update_elem(array_fd, &array_key, &ifindex, 0);
+	if (ret) {
+		perror("bpf_map_update_elem");
+		goto out;
+	}
+
+out:
+	if (array_fd != -1)
+		close(array_fd);
+	return ret;
+}
diff --git a/samples/bpf/tcbpf1_kern.c b/samples/bpf/tcbpf1_kern.c
new file mode 100644
index 000000000..e9356130f
--- /dev/null
+++ b/samples/bpf/tcbpf1_kern.c
@@ -0,0 +1,91 @@
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/filter.h>
+#include <uapi/linux/pkt_cls.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+
+/* compiler workaround */
+#define _htonl __builtin_bswap32
+
+static inline void set_dst_mac(struct __sk_buff *skb, char *mac)
+{
+	bpf_skb_store_bytes(skb, 0, mac, ETH_ALEN, 1);
+}
+
+#define IP_CSUM_OFF (ETH_HLEN + offsetof(struct iphdr, check))
+#define TOS_OFF (ETH_HLEN + offsetof(struct iphdr, tos))
+
+static inline void set_ip_tos(struct __sk_buff *skb, __u8 new_tos)
+{
+	__u8 old_tos = load_byte(skb, TOS_OFF);
+
+	bpf_l3_csum_replace(skb, IP_CSUM_OFF, htons(old_tos), htons(new_tos), 2);
+	bpf_skb_store_bytes(skb, TOS_OFF, &new_tos, sizeof(new_tos), 0);
+}
+
+#define TCP_CSUM_OFF (ETH_HLEN + sizeof(struct iphdr) + offsetof(struct tcphdr, check))
+#define IP_SRC_OFF (ETH_HLEN + offsetof(struct iphdr, saddr))
+
+#define IS_PSEUDO 0x10
+
+static inline void set_tcp_ip_src(struct __sk_buff *skb, __u32 new_ip)
+{
+	__u32 old_ip = _htonl(load_word(skb, IP_SRC_OFF));
+
+	bpf_l4_csum_replace(skb, TCP_CSUM_OFF, old_ip, new_ip, IS_PSEUDO | sizeof(new_ip));
+	bpf_l3_csum_replace(skb, IP_CSUM_OFF, old_ip, new_ip, sizeof(new_ip));
+	bpf_skb_store_bytes(skb, IP_SRC_OFF, &new_ip, sizeof(new_ip), 0);
+}
+
+#define TCP_DPORT_OFF (ETH_HLEN + sizeof(struct iphdr) + offsetof(struct tcphdr, dest))
+static inline void set_tcp_dest_port(struct __sk_buff *skb, __u16 new_port)
+{
+	__u16 old_port = htons(load_half(skb, TCP_DPORT_OFF));
+
+	bpf_l4_csum_replace(skb, TCP_CSUM_OFF, old_port, new_port, sizeof(new_port));
+	bpf_skb_store_bytes(skb, TCP_DPORT_OFF, &new_port, sizeof(new_port), 0);
+}
+
+SEC("classifier")
+int bpf_prog1(struct __sk_buff *skb)
+{
+	__u8 proto = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
+	long *value;
+
+	if (proto == IPPROTO_TCP) {
+		set_ip_tos(skb, 8);
+		set_tcp_ip_src(skb, 0xA010101);
+		set_tcp_dest_port(skb, 5001);
+	}
+
+	return 0;
+}
+SEC("redirect_xmit")
+int _redirect_xmit(struct __sk_buff *skb)
+{
+	return bpf_redirect(skb->ifindex + 1, 0);
+}
+SEC("redirect_recv")
+int _redirect_recv(struct __sk_buff *skb)
+{
+	return bpf_redirect(skb->ifindex + 1, 1);
+}
+SEC("clone_redirect_xmit")
+int _clone_redirect_xmit(struct __sk_buff *skb)
+{
+	bpf_clone_redirect(skb, skb->ifindex + 1, 0);
+	return TC_ACT_SHOT;
+}
+SEC("clone_redirect_recv")
+int _clone_redirect_recv(struct __sk_buff *skb)
+{
+	bpf_clone_redirect(skb, skb->ifindex + 1, 1);
+	return TC_ACT_SHOT;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_basertt_kern.c b/samples/bpf/tcp_basertt_kern.c
new file mode 100644
index 000000000..822b0742b
--- /dev/null
+++ b/samples/bpf/tcp_basertt_kern.c
@@ -0,0 +1,71 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * BPF program to set base_rtt to 80us when host is running TCP-NV and
+ * both hosts are in the same datacenter (as determined by IPv6 prefix).
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_basertt(struct bpf_sock_ops *skops)
+{
+	char cong[20];
+	char nv[] = "nv";
+	int rv = 0, n;
+	int op;
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+
+	/* Check if both hosts are in the same datacenter. For this
+	 * example they are if the 1st 5.5 bytes in the IPv6 address
+	 * are the same.
+	 */
+	if (skops->family == AF_INET6 &&
+	    skops->local_ip6[0] == skops->remote_ip6[0] &&
+	    (bpf_ntohl(skops->local_ip6[1]) & 0xfff00000) ==
+	    (bpf_ntohl(skops->remote_ip6[1]) & 0xfff00000)) {
+		switch (op) {
+		case BPF_SOCK_OPS_BASE_RTT:
+			n = bpf_getsockopt(skops, SOL_TCP, TCP_CONGESTION,
+					   cong, sizeof(cong));
+			if (!n && !__builtin_memcmp(cong, nv, sizeof(nv))) {
+				/* Set base_rtt to 80us */
+				rv = 80;
+			} else if (n) {
+				rv = n;
+			} else {
+				rv = -1;
+			}
+			break;
+		default:
+			rv = -1;
+		}
+	} else {
+		rv = -1;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_bpf.readme b/samples/bpf/tcp_bpf.readme
new file mode 100644
index 000000000..78e247f62
--- /dev/null
+++ b/samples/bpf/tcp_bpf.readme
@@ -0,0 +1,28 @@
+This file describes how to run the tcp_*_kern.o tcp_bpf (or socket_ops)
+programs. These programs attach to a cgroupv2. The following commands create
+a cgroupv2 and attach a bash shell to the group.
+
+  mkdir -p /tmp/cgroupv2
+  mount -t cgroup2 none /tmp/cgroupv2
+  mkdir -p /tmp/cgroupv2/foo
+  bash
+  echo $$ >> /tmp/cgroupv2/foo/cgroup.procs
+
+Anything that runs under this shell belongs to the foo cgroupv2. To load
+(attach) one of the tcp_*_kern.o programs:
+
+  bpftool prog load tcp_basertt_kern.o /sys/fs/bpf/tcp_prog
+  bpftool cgroup attach /tmp/cgroupv2/foo sock_ops pinned /sys/fs/bpf/tcp_prog
+  bpftool prog tracelog
+
+"bpftool prog tracelog" will continue to run printing the BPF log buffer.
+The tcp_*_kern.o programs use special print functions to print logging
+information (if enabled by the ifdef).
+
+If using netperf/netserver to create traffic, you need to run them under the
+cgroupv2 to which the BPF programs are attached (i.e. under bash shell
+attached to the cgroupv2).
+
+To remove (unattach) a socket_ops BPF program from a cgroupv2:
+
+  bpftool cgroup detach /tmp/cgroupv2/foo sock_ops pinned /sys/fs/bpf/tcp_prog
diff --git a/samples/bpf/tcp_bufs_kern.c b/samples/bpf/tcp_bufs_kern.c
new file mode 100644
index 000000000..6a80d0895
--- /dev/null
+++ b/samples/bpf/tcp_bufs_kern.c
@@ -0,0 +1,81 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * BPF program to set initial receive window to 40 packets and send
+ * and receive buffers to 1.5MB. This would usually be done after
+ * doing appropriate checks that indicate the hosts are far enough
+ * away (i.e. large RTT).
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_bufs(struct bpf_sock_ops *skops)
+{
+	int bufsize = 1500000;
+	int rwnd_init = 40;
+	int rv = 0;
+	int op;
+
+	/* For testing purposes, only execute rest of BPF program
+	 * if neither port numberis 55601
+	 */
+	if (bpf_ntohl(skops->remote_port) != 55601 &&
+	    skops->local_port != 55601) {
+		skops->reply = -1;
+		return 1;
+	}
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+
+	/* Usually there would be a check to insure the hosts are far
+	 * from each other so it makes sense to increase buffer sizes
+	 */
+	switch (op) {
+	case BPF_SOCK_OPS_RWND_INIT:
+		rv = rwnd_init;
+		break;
+	case BPF_SOCK_OPS_TCP_CONNECT_CB:
+		/* Set sndbuf and rcvbuf of active connections */
+		rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
+				    sizeof(bufsize));
+		rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
+				     &bufsize, sizeof(bufsize));
+		break;
+	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
+		/* Nothing to do */
+		break;
+	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+		/* Set sndbuf and rcvbuf of passive connections */
+		rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
+				    sizeof(bufsize));
+		rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
+				     &bufsize, sizeof(bufsize));
+		break;
+	default:
+		rv = -1;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_clamp_kern.c b/samples/bpf/tcp_clamp_kern.c
new file mode 100644
index 000000000..e88bd9ab0
--- /dev/null
+++ b/samples/bpf/tcp_clamp_kern.c
@@ -0,0 +1,97 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Sample BPF program to set send and receive buffers to 150KB, sndcwnd clamp
+ * to 100 packets and SYN and SYN_ACK RTOs to 10ms when both hosts are within
+ * the same datacenter. For his example, we assume they are within the same
+ * datacenter when the first 5.5 bytes of their IPv6 addresses are the same.
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_clamp(struct bpf_sock_ops *skops)
+{
+	int bufsize = 150000;
+	int to_init = 10;
+	int clamp = 100;
+	int rv = 0;
+	int op;
+
+	/* For testing purposes, only execute rest of BPF program
+	 * if neither port numberis 55601
+	 */
+	if (bpf_ntohl(skops->remote_port) != 55601 && skops->local_port != 55601) {
+		skops->reply = -1;
+		return 0;
+	}
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+
+	/* Check that both hosts are within same datacenter. For this example
+	 * it is the case when the first 5.5 bytes of their IPv6 addresses are
+	 * the same.
+	 */
+	if (skops->family == AF_INET6 &&
+	    skops->local_ip6[0] == skops->remote_ip6[0] &&
+	    (bpf_ntohl(skops->local_ip6[1]) & 0xfff00000) ==
+	    (bpf_ntohl(skops->remote_ip6[1]) & 0xfff00000)) {
+		switch (op) {
+		case BPF_SOCK_OPS_TIMEOUT_INIT:
+			rv = to_init;
+			break;
+		case BPF_SOCK_OPS_TCP_CONNECT_CB:
+			/* Set sndbuf and rcvbuf of active connections */
+			rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF,
+					    &bufsize, sizeof(bufsize));
+			rv += bpf_setsockopt(skops, SOL_SOCKET,
+					     SO_RCVBUF, &bufsize,
+					     sizeof(bufsize));
+			break;
+		case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
+			rv = bpf_setsockopt(skops, SOL_TCP,
+					    TCP_BPF_SNDCWND_CLAMP,
+					    &clamp, sizeof(clamp));
+			break;
+		case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+			/* Set sndbuf and rcvbuf of passive connections */
+			rv = bpf_setsockopt(skops, SOL_TCP,
+					    TCP_BPF_SNDCWND_CLAMP,
+					    &clamp, sizeof(clamp));
+			rv += bpf_setsockopt(skops, SOL_SOCKET,
+					     SO_SNDBUF, &bufsize,
+					     sizeof(bufsize));
+			rv += bpf_setsockopt(skops, SOL_SOCKET,
+					     SO_RCVBUF, &bufsize,
+					     sizeof(bufsize));
+			break;
+		default:
+			rv = -1;
+		}
+	} else {
+		rv = -1;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_cong_kern.c b/samples/bpf/tcp_cong_kern.c
new file mode 100644
index 000000000..2311fc9dd
--- /dev/null
+++ b/samples/bpf/tcp_cong_kern.c
@@ -0,0 +1,78 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * BPF program to set congestion control to dctcp when both hosts are
+ * in the same datacenter (as deteremined by IPv6 prefix).
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_cong(struct bpf_sock_ops *skops)
+{
+	char cong[] = "dctcp";
+	int rv = 0;
+	int op;
+
+	/* For testing purposes, only execute rest of BPF program
+	 * if neither port numberis 55601
+	 */
+	if (bpf_ntohl(skops->remote_port) != 55601 &&
+	    skops->local_port != 55601) {
+		skops->reply = -1;
+		return 1;
+	}
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+
+	/* Check if both hosts are in the same datacenter. For this
+	 * example they are if the 1st 5.5 bytes in the IPv6 address
+	 * are the same.
+	 */
+	if (skops->family == AF_INET6 &&
+	    skops->local_ip6[0] == skops->remote_ip6[0] &&
+	    (bpf_ntohl(skops->local_ip6[1]) & 0xfff00000) ==
+	    (bpf_ntohl(skops->remote_ip6[1]) & 0xfff00000)) {
+		switch (op) {
+		case BPF_SOCK_OPS_NEEDS_ECN:
+			rv = 1;
+			break;
+		case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
+			rv = bpf_setsockopt(skops, SOL_TCP, TCP_CONGESTION,
+					    cong, sizeof(cong));
+			break;
+		case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+			rv = bpf_setsockopt(skops, SOL_TCP, TCP_CONGESTION,
+					    cong, sizeof(cong));
+			break;
+		default:
+			rv = -1;
+		}
+	} else {
+		rv = -1;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_dumpstats_kern.c b/samples/bpf/tcp_dumpstats_kern.c
new file mode 100644
index 000000000..e80d3afd2
--- /dev/null
+++ b/samples/bpf/tcp_dumpstats_kern.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Refer to samples/bpf/tcp_bpf.readme for the instructions on
+ * how to run this sample program.
+ */
+#include <linux/bpf.h>
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define INTERVAL			1000000000ULL
+
+int _version SEC("version") = 1;
+char _license[] SEC("license") = "GPL";
+
+struct {
+	__u32 type;
+	__u32 map_flags;
+	int *key;
+	__u64 *value;
+} bpf_next_dump SEC(".maps") = {
+	.type = BPF_MAP_TYPE_SK_STORAGE,
+	.map_flags = BPF_F_NO_PREALLOC,
+};
+
+SEC("sockops")
+int _sockops(struct bpf_sock_ops *ctx)
+{
+	struct bpf_tcp_sock *tcp_sk;
+	struct bpf_sock *sk;
+	__u64 *next_dump;
+	__u64 now;
+
+	switch (ctx->op) {
+	case BPF_SOCK_OPS_TCP_CONNECT_CB:
+		bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG);
+		return 1;
+	case BPF_SOCK_OPS_RTT_CB:
+		break;
+	default:
+		return 1;
+	}
+
+	sk = ctx->sk;
+	if (!sk)
+		return 1;
+
+	next_dump = bpf_sk_storage_get(&bpf_next_dump, sk, 0,
+				       BPF_SK_STORAGE_GET_F_CREATE);
+	if (!next_dump)
+		return 1;
+
+	now = bpf_ktime_get_ns();
+	if (now < *next_dump)
+		return 1;
+
+	tcp_sk = bpf_tcp_sock(sk);
+	if (!tcp_sk)
+		return 1;
+
+	*next_dump = now + INTERVAL;
+
+	bpf_printk("dsack_dups=%u delivered=%u\n",
+		   tcp_sk->dsack_dups, tcp_sk->delivered);
+	bpf_printk("delivered_ce=%u icsk_retransmits=%u\n",
+		   tcp_sk->delivered_ce, tcp_sk->icsk_retransmits);
+
+	return 1;
+}
diff --git a/samples/bpf/tcp_iw_kern.c b/samples/bpf/tcp_iw_kern.c
new file mode 100644
index 000000000..d14445573
--- /dev/null
+++ b/samples/bpf/tcp_iw_kern.c
@@ -0,0 +1,83 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * BPF program to set initial congestion window and initial receive
+ * window to 40 packets and send and receive buffers to 1.5MB. This
+ * would usually be done after doing appropriate checks that indicate
+ * the hosts are far enough away (i.e. large RTT).
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_iw(struct bpf_sock_ops *skops)
+{
+	int bufsize = 1500000;
+	int rwnd_init = 40;
+	int iw = 40;
+	int rv = 0;
+	int op;
+
+	/* For testing purposes, only execute rest of BPF program
+	 * if neither port numberis 55601
+	 */
+	if (bpf_ntohl(skops->remote_port) != 55601 &&
+	    skops->local_port != 55601) {
+		skops->reply = -1;
+		return 1;
+	}
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+
+	/* Usually there would be a check to insure the hosts are far
+	 * from each other so it makes sense to increase buffer sizes
+	 */
+	switch (op) {
+	case BPF_SOCK_OPS_RWND_INIT:
+		rv = rwnd_init;
+		break;
+	case BPF_SOCK_OPS_TCP_CONNECT_CB:
+		/* Set sndbuf and rcvbuf of active connections */
+		rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
+				    sizeof(bufsize));
+		rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
+				     &bufsize, sizeof(bufsize));
+		break;
+	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
+		rv = bpf_setsockopt(skops, SOL_TCP, TCP_BPF_IW, &iw,
+				    sizeof(iw));
+		break;
+	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+		/* Set sndbuf and rcvbuf of passive connections */
+		rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
+				    sizeof(bufsize));
+		rv +=  bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
+				      &bufsize, sizeof(bufsize));
+		break;
+	default:
+		rv = -1;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_rwnd_kern.c b/samples/bpf/tcp_rwnd_kern.c
new file mode 100644
index 000000000..223d9c23b
--- /dev/null
+++ b/samples/bpf/tcp_rwnd_kern.c
@@ -0,0 +1,64 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * BPF program to set initial receive window to 40 packets when using IPv6
+ * and the first 5.5 bytes of the IPv6 addresses are not the same (in this
+ * example that means both hosts are not the same datacenter).
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_rwnd(struct bpf_sock_ops *skops)
+{
+	int rv = -1;
+	int op;
+
+	/* For testing purposes, only execute rest of BPF program
+	 * if neither port numberis 55601
+	 */
+	if (bpf_ntohl(skops->remote_port) !=
+	    55601 && skops->local_port != 55601) {
+		skops->reply = -1;
+		return 1;
+	}
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+
+	/* Check for RWND_INIT operation and IPv6 addresses */
+	if (op == BPF_SOCK_OPS_RWND_INIT &&
+		skops->family == AF_INET6) {
+
+		/* If the first 5.5 bytes of the IPv6 address are not the same
+		 * then both hosts are not in the same datacenter
+		 * so use a larger initial advertized window (40 packets)
+		 */
+		if (skops->local_ip6[0] != skops->remote_ip6[0] ||
+		    (bpf_ntohl(skops->local_ip6[1]) & 0xfffff000) !=
+		    (bpf_ntohl(skops->remote_ip6[1]) & 0xfffff000))
+			rv = 40;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_synrto_kern.c b/samples/bpf/tcp_synrto_kern.c
new file mode 100644
index 000000000..d58004eef
--- /dev/null
+++ b/samples/bpf/tcp_synrto_kern.c
@@ -0,0 +1,64 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * BPF program to set SYN and SYN-ACK RTOs to 10ms when using IPv6 addresses
+ * and the first 5.5 bytes of the IPv6 addresses are the same (in this example
+ * that means both hosts are in the same datacenter).
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_synrto(struct bpf_sock_ops *skops)
+{
+	int rv = -1;
+	int op;
+
+	/* For testing purposes, only execute rest of BPF program
+	 * if neither port numberis 55601
+	 */
+	if (bpf_ntohl(skops->remote_port) != 55601 &&
+	    skops->local_port != 55601) {
+		skops->reply = -1;
+		return 1;
+	}
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+
+	/* Check for TIMEOUT_INIT operation and IPv6 addresses */
+	if (op == BPF_SOCK_OPS_TIMEOUT_INIT &&
+		skops->family == AF_INET6) {
+
+		/* If the first 5.5 bytes of the IPv6 address are the same
+		 * then both hosts are in the same datacenter
+		 * so use an RTO of 10ms
+		 */
+		if (skops->local_ip6[0] == skops->remote_ip6[0] &&
+		    (bpf_ntohl(skops->local_ip6[1]) & 0xfff00000) ==
+		    (bpf_ntohl(skops->remote_ip6[1]) & 0xfff00000))
+			rv = 10;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_tos_reflect_kern.c b/samples/bpf/tcp_tos_reflect_kern.c
new file mode 100644
index 000000000..953fedc79
--- /dev/null
+++ b/samples/bpf/tcp_tos_reflect_kern.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 Facebook
+ *
+ * BPF program to automatically reflect TOS option from received syn packet
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/in.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_basertt(struct bpf_sock_ops *skops)
+{
+	char header[sizeof(struct ipv6hdr)];
+	struct ipv6hdr *hdr6;
+	struct iphdr *hdr;
+	int hdr_size = 0;
+	int save_syn = 1;
+	int tos = 0;
+	int rv = 0;
+	int op;
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+	switch (op) {
+	case BPF_SOCK_OPS_TCP_LISTEN_CB:
+		rv = bpf_setsockopt(skops, SOL_TCP, TCP_SAVE_SYN,
+				   &save_syn, sizeof(save_syn));
+		break;
+	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+		if (skops->family == AF_INET)
+			hdr_size = sizeof(struct iphdr);
+		else
+			hdr_size = sizeof(struct ipv6hdr);
+		rv = bpf_getsockopt(skops, SOL_TCP, TCP_SAVED_SYN,
+				    header, hdr_size);
+		if (!rv) {
+			if (skops->family == AF_INET) {
+				hdr = (struct iphdr *) header;
+				tos = hdr->tos;
+				if (tos != 0)
+					bpf_setsockopt(skops, SOL_IP, IP_TOS,
+						       &tos, sizeof(tos));
+			} else {
+				hdr6 = (struct ipv6hdr *) header;
+				tos = ((hdr6->priority) << 4 |
+				       (hdr6->flow_lbl[0]) >>  4);
+				if (tos)
+					bpf_setsockopt(skops, SOL_IPV6,
+						       IPV6_TCLASS,
+						       &tos, sizeof(tos));
+			}
+			rv = 0;
+		}
+		break;
+	default:
+		rv = -1;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/test_cgrp2_array_pin.c b/samples/bpf/test_cgrp2_array_pin.c
new file mode 100644
index 000000000..6d564aa75
--- /dev/null
+++ b/samples/bpf/test_cgrp2_array_pin.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include <linux/unistd.h>
+#include <linux/bpf.h>
+
+#include <stdio.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include <bpf/bpf.h>
+
+static void usage(void)
+{
+	printf("Usage: test_cgrp2_array_pin [...]\n");
+	printf("       -F <file>   File to pin an BPF cgroup array\n");
+	printf("       -U <file>   Update an already pinned BPF cgroup array\n");
+	printf("       -v <value>  Full path of the cgroup2\n");
+	printf("       -h          Display this help\n");
+}
+
+int main(int argc, char **argv)
+{
+	const char *pinned_file = NULL, *cg2 = NULL;
+	int create_array = 1;
+	int array_key = 0;
+	int array_fd = -1;
+	int cg2_fd = -1;
+	int ret = -1;
+	int opt;
+
+	while ((opt = getopt(argc, argv, "F:U:v:")) != -1) {
+		switch (opt) {
+		/* General args */
+		case 'F':
+			pinned_file = optarg;
+			break;
+		case 'U':
+			pinned_file = optarg;
+			create_array = 0;
+			break;
+		case 'v':
+			cg2 = optarg;
+			break;
+		default:
+			usage();
+			goto out;
+		}
+	}
+
+	if (!cg2 || !pinned_file) {
+		usage();
+		goto out;
+	}
+
+	cg2_fd = open(cg2, O_RDONLY);
+	if (cg2_fd < 0) {
+		fprintf(stderr, "open(%s,...): %s(%d)\n",
+			cg2, strerror(errno), errno);
+		goto out;
+	}
+
+	if (create_array) {
+		array_fd = bpf_create_map(BPF_MAP_TYPE_CGROUP_ARRAY,
+					  sizeof(uint32_t), sizeof(uint32_t),
+					  1, 0);
+		if (array_fd < 0) {
+			fprintf(stderr,
+				"bpf_create_map(BPF_MAP_TYPE_CGROUP_ARRAY,...): %s(%d)\n",
+				strerror(errno), errno);
+			goto out;
+		}
+	} else {
+		array_fd = bpf_obj_get(pinned_file);
+		if (array_fd < 0) {
+			fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
+				pinned_file, strerror(errno), errno);
+			goto out;
+		}
+	}
+
+	ret = bpf_map_update_elem(array_fd, &array_key, &cg2_fd, 0);
+	if (ret) {
+		perror("bpf_map_update_elem");
+		goto out;
+	}
+
+	if (create_array) {
+		ret = bpf_obj_pin(array_fd, pinned_file);
+		if (ret) {
+			fprintf(stderr, "bpf_obj_pin(..., %s): %s(%d)\n",
+				pinned_file, strerror(errno), errno);
+			goto out;
+		}
+	}
+
+out:
+	if (array_fd != -1)
+		close(array_fd);
+	if (cg2_fd != -1)
+		close(cg2_fd);
+	return ret;
+}
diff --git a/samples/bpf/test_cgrp2_attach.c b/samples/bpf/test_cgrp2_attach.c
new file mode 100644
index 000000000..20fbd1241
--- /dev/null
+++ b/samples/bpf/test_cgrp2_attach.c
@@ -0,0 +1,172 @@
+/* eBPF example program:
+ *
+ * - Creates arraymap in kernel with 4 bytes keys and 8 byte values
+ *
+ * - Loads eBPF program
+ *
+ *   The eBPF program accesses the map passed in to store two pieces of
+ *   information. The number of invocations of the program, which maps
+ *   to the number of packets received, is stored to key 0. Key 1 is
+ *   incremented on each iteration by the number of bytes stored in
+ *   the skb.
+ *
+ * - Attaches the new program to a cgroup using BPF_PROG_ATTACH
+ *
+ * - Every second, reads map[0] and map[1] to see how many bytes and
+ *   packets were seen on any socket of tasks in the given cgroup.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <unistd.h>
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+
+#include "bpf_insn.h"
+
+enum {
+	MAP_KEY_PACKETS,
+	MAP_KEY_BYTES,
+};
+
+char bpf_log_buf[BPF_LOG_BUF_SIZE];
+
+static int prog_load(int map_fd, int verdict)
+{
+	struct bpf_insn prog[] = {
+		BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), /* save r6 so it's not clobbered by BPF_CALL */
+
+		/* Count packets */
+		BPF_MOV64_IMM(BPF_REG_0, MAP_KEY_PACKETS), /* r0 = 0 */
+		BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */
+		BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */
+		BPF_LD_MAP_FD(BPF_REG_1, map_fd), /* load map fd to r1 */
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
+		BPF_MOV64_IMM(BPF_REG_1, 1), /* r1 = 1 */
+		BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */
+
+		/* Count bytes */
+		BPF_MOV64_IMM(BPF_REG_0, MAP_KEY_BYTES), /* r0 = 1 */
+		BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */
+		BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */
+		BPF_LD_MAP_FD(BPF_REG_1, map_fd),
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
+		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6, offsetof(struct __sk_buff, len)), /* r1 = skb->len */
+		BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */
+
+		BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
+		BPF_EXIT_INSN(),
+	};
+	size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
+
+	return bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
+				prog, insns_cnt, "GPL", 0,
+				bpf_log_buf, BPF_LOG_BUF_SIZE);
+}
+
+static int usage(const char *argv0)
+{
+	printf("Usage: %s [-d] [-D] <cg-path> <egress|ingress>\n", argv0);
+	printf("	-d	Drop Traffic\n");
+	printf("	-D	Detach filter, and exit\n");
+	return EXIT_FAILURE;
+}
+
+static int attach_filter(int cg_fd, int type, int verdict)
+{
+	int prog_fd, map_fd, ret, key;
+	long long pkt_cnt, byte_cnt;
+
+	map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY,
+				sizeof(key), sizeof(byte_cnt),
+				256, 0);
+	if (map_fd < 0) {
+		printf("Failed to create map: '%s'\n", strerror(errno));
+		return EXIT_FAILURE;
+	}
+
+	prog_fd = prog_load(map_fd, verdict);
+	printf("Output from kernel verifier:\n%s\n-------\n", bpf_log_buf);
+
+	if (prog_fd < 0) {
+		printf("Failed to load prog: '%s'\n", strerror(errno));
+		return EXIT_FAILURE;
+	}
+
+	ret = bpf_prog_attach(prog_fd, cg_fd, type, 0);
+	if (ret < 0) {
+		printf("Failed to attach prog to cgroup: '%s'\n",
+		       strerror(errno));
+		return EXIT_FAILURE;
+	}
+	while (1) {
+		key = MAP_KEY_PACKETS;
+		assert(bpf_map_lookup_elem(map_fd, &key, &pkt_cnt) == 0);
+
+		key = MAP_KEY_BYTES;
+		assert(bpf_map_lookup_elem(map_fd, &key, &byte_cnt) == 0);
+
+		printf("cgroup received %lld packets, %lld bytes\n",
+		       pkt_cnt, byte_cnt);
+		sleep(1);
+	}
+
+	return EXIT_SUCCESS;
+}
+
+int main(int argc, char **argv)
+{
+	int detach_only = 0, verdict = 1;
+	enum bpf_attach_type type;
+	int opt, cg_fd, ret;
+
+	while ((opt = getopt(argc, argv, "Dd")) != -1) {
+		switch (opt) {
+		case 'd':
+			verdict = 0;
+			break;
+		case 'D':
+			detach_only = 1;
+			break;
+		default:
+			return usage(argv[0]);
+		}
+	}
+
+	if (argc - optind < 2)
+		return usage(argv[0]);
+
+	if (strcmp(argv[optind + 1], "ingress") == 0)
+		type = BPF_CGROUP_INET_INGRESS;
+	else if (strcmp(argv[optind + 1], "egress") == 0)
+		type = BPF_CGROUP_INET_EGRESS;
+	else
+		return usage(argv[0]);
+
+	cg_fd = open(argv[optind], O_DIRECTORY | O_RDONLY);
+	if (cg_fd < 0) {
+		printf("Failed to open cgroup path: '%s'\n", strerror(errno));
+		return EXIT_FAILURE;
+	}
+
+	if (detach_only) {
+		ret = bpf_prog_detach(cg_fd, type);
+		printf("bpf_prog_detach() returned '%s' (%d)\n",
+		       strerror(errno), errno);
+	} else
+		ret = attach_filter(cg_fd, type, verdict);
+
+	return ret;
+}
diff --git a/samples/bpf/test_cgrp2_sock.c b/samples/bpf/test_cgrp2_sock.c
new file mode 100644
index 000000000..b0811da5a
--- /dev/null
+++ b/samples/bpf/test_cgrp2_sock.c
@@ -0,0 +1,290 @@
+/* eBPF example program:
+ *
+ * - Loads eBPF program
+ *
+ *   The eBPF program sets the sk_bound_dev_if index in new AF_INET{6}
+ *   sockets opened by processes in the cgroup.
+ *
+ * - Attaches the new program to a cgroup using BPF_PROG_ATTACH
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <unistd.h>
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <net/if.h>
+#include <inttypes.h>
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+
+#include "bpf_insn.h"
+
+char bpf_log_buf[BPF_LOG_BUF_SIZE];
+
+static int prog_load(__u32 idx, __u32 mark, __u32 prio)
+{
+	/* save pointer to context */
+	struct bpf_insn prog_start[] = {
+		BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+	};
+	struct bpf_insn prog_end[] = {
+		BPF_MOV64_IMM(BPF_REG_0, 1), /* r0 = verdict */
+		BPF_EXIT_INSN(),
+	};
+
+	/* set sk_bound_dev_if on socket */
+	struct bpf_insn prog_dev[] = {
+		BPF_MOV64_IMM(BPF_REG_3, idx),
+		BPF_MOV64_IMM(BPF_REG_2, offsetof(struct bpf_sock, bound_dev_if)),
+		BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3, offsetof(struct bpf_sock, bound_dev_if)),
+	};
+
+	/* set mark on socket */
+	struct bpf_insn prog_mark[] = {
+		/* get uid of process */
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+			     BPF_FUNC_get_current_uid_gid),
+		BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xffffffff),
+
+		/* if uid is 0, use given mark, else use the uid as the mark */
+		BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
+		BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+		BPF_MOV64_IMM(BPF_REG_3, mark),
+
+		/* set the mark on the new socket */
+		BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+		BPF_MOV64_IMM(BPF_REG_2, offsetof(struct bpf_sock, mark)),
+		BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3, offsetof(struct bpf_sock, mark)),
+	};
+
+	/* set priority on socket */
+	struct bpf_insn prog_prio[] = {
+		BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+		BPF_MOV64_IMM(BPF_REG_3, prio),
+		BPF_MOV64_IMM(BPF_REG_2, offsetof(struct bpf_sock, priority)),
+		BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3, offsetof(struct bpf_sock, priority)),
+	};
+
+	struct bpf_insn *prog;
+	size_t insns_cnt;
+	void *p;
+	int ret;
+
+	insns_cnt = sizeof(prog_start) + sizeof(prog_end);
+	if (idx)
+		insns_cnt += sizeof(prog_dev);
+
+	if (mark)
+		insns_cnt += sizeof(prog_mark);
+
+	if (prio)
+		insns_cnt += sizeof(prog_prio);
+
+	p = prog = malloc(insns_cnt);
+	if (!prog) {
+		fprintf(stderr, "Failed to allocate memory for instructions\n");
+		return EXIT_FAILURE;
+	}
+
+	memcpy(p, prog_start, sizeof(prog_start));
+	p += sizeof(prog_start);
+
+	if (idx) {
+		memcpy(p, prog_dev, sizeof(prog_dev));
+		p += sizeof(prog_dev);
+	}
+
+	if (mark) {
+		memcpy(p, prog_mark, sizeof(prog_mark));
+		p += sizeof(prog_mark);
+	}
+
+	if (prio) {
+		memcpy(p, prog_prio, sizeof(prog_prio));
+		p += sizeof(prog_prio);
+	}
+
+	memcpy(p, prog_end, sizeof(prog_end));
+	p += sizeof(prog_end);
+
+	insns_cnt /= sizeof(struct bpf_insn);
+
+	ret = bpf_load_program(BPF_PROG_TYPE_CGROUP_SOCK, prog, insns_cnt,
+				"GPL", 0, bpf_log_buf, BPF_LOG_BUF_SIZE);
+
+	free(prog);
+
+	return ret;
+}
+
+static int get_bind_to_device(int sd, char *name, size_t len)
+{
+	socklen_t optlen = len;
+	int rc;
+
+	name[0] = '\0';
+	rc = getsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, name, &optlen);
+	if (rc < 0)
+		perror("setsockopt(SO_BINDTODEVICE)");
+
+	return rc;
+}
+
+static unsigned int get_somark(int sd)
+{
+	unsigned int mark = 0;
+	socklen_t optlen = sizeof(mark);
+	int rc;
+
+	rc = getsockopt(sd, SOL_SOCKET, SO_MARK, &mark, &optlen);
+	if (rc < 0)
+		perror("getsockopt(SO_MARK)");
+
+	return mark;
+}
+
+static unsigned int get_priority(int sd)
+{
+	unsigned int prio = 0;
+	socklen_t optlen = sizeof(prio);
+	int rc;
+
+	rc = getsockopt(sd, SOL_SOCKET, SO_PRIORITY, &prio, &optlen);
+	if (rc < 0)
+		perror("getsockopt(SO_PRIORITY)");
+
+	return prio;
+}
+
+static int show_sockopts(int family)
+{
+	unsigned int mark, prio;
+	char name[16];
+	int sd;
+
+	sd = socket(family, SOCK_DGRAM, 17);
+	if (sd < 0) {
+		perror("socket");
+		return 1;
+	}
+
+	if (get_bind_to_device(sd, name, sizeof(name)) < 0)
+		return 1;
+
+	mark = get_somark(sd);
+	prio = get_priority(sd);
+
+	close(sd);
+
+	printf("sd %d: dev %s, mark %u, priority %u\n", sd, name, mark, prio);
+
+	return 0;
+}
+
+static int usage(const char *argv0)
+{
+	printf("Usage:\n");
+	printf("  Attach a program\n");
+	printf("  %s -b bind-to-dev -m mark -p prio cg-path\n", argv0);
+	printf("\n");
+	printf("  Detach a program\n");
+	printf("  %s -d cg-path\n", argv0);
+	printf("\n");
+	printf("  Show inherited socket settings (mark, priority, and device)\n");
+	printf("  %s [-6]\n", argv0);
+	return EXIT_FAILURE;
+}
+
+int main(int argc, char **argv)
+{
+	__u32 idx = 0, mark = 0, prio = 0;
+	const char *cgrp_path = NULL;
+	int cg_fd, prog_fd, ret;
+	int family = PF_INET;
+	int do_attach = 1;
+	int rc;
+
+	while ((rc = getopt(argc, argv, "db:m:p:6")) != -1) {
+		switch (rc) {
+		case 'd':
+			do_attach = 0;
+			break;
+		case 'b':
+			idx = if_nametoindex(optarg);
+			if (!idx) {
+				idx = strtoumax(optarg, NULL, 0);
+				if (!idx) {
+					printf("Invalid device name\n");
+					return EXIT_FAILURE;
+				}
+			}
+			break;
+		case 'm':
+			mark = strtoumax(optarg, NULL, 0);
+			break;
+		case 'p':
+			prio = strtoumax(optarg, NULL, 0);
+			break;
+		case '6':
+			family = PF_INET6;
+			break;
+		default:
+			return usage(argv[0]);
+		}
+	}
+
+	if (optind == argc)
+		return show_sockopts(family);
+
+	cgrp_path = argv[optind];
+	if (!cgrp_path) {
+		fprintf(stderr, "cgroup path not given\n");
+		return EXIT_FAILURE;
+	}
+
+	if (do_attach && !idx && !mark && !prio) {
+		fprintf(stderr,
+			"One of device, mark or priority must be given\n");
+		return EXIT_FAILURE;
+	}
+
+	cg_fd = open(cgrp_path, O_DIRECTORY | O_RDONLY);
+	if (cg_fd < 0) {
+		printf("Failed to open cgroup path: '%s'\n", strerror(errno));
+		return EXIT_FAILURE;
+	}
+
+	if (do_attach) {
+		prog_fd = prog_load(idx, mark, prio);
+		if (prog_fd < 0) {
+			printf("Failed to load prog: '%s'\n", strerror(errno));
+			printf("Output from kernel verifier:\n%s\n-------\n",
+			       bpf_log_buf);
+			return EXIT_FAILURE;
+		}
+
+		ret = bpf_prog_attach(prog_fd, cg_fd,
+				      BPF_CGROUP_INET_SOCK_CREATE, 0);
+		if (ret < 0) {
+			printf("Failed to attach prog to cgroup: '%s'\n",
+			       strerror(errno));
+			return EXIT_FAILURE;
+		}
+	} else {
+		ret = bpf_prog_detach(cg_fd, BPF_CGROUP_INET_SOCK_CREATE);
+		if (ret < 0) {
+			printf("Failed to detach prog from cgroup: '%s'\n",
+			       strerror(errno));
+			return EXIT_FAILURE;
+		}
+	}
+
+	close(cg_fd);
+	return EXIT_SUCCESS;
+}
diff --git a/samples/bpf/test_cgrp2_sock.sh b/samples/bpf/test_cgrp2_sock.sh
new file mode 100755
index 000000000..9f6174236
--- /dev/null
+++ b/samples/bpf/test_cgrp2_sock.sh
@@ -0,0 +1,135 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+# Test various socket options that can be set by attaching programs to cgroups.
+
+CGRP_MNT="/tmp/cgroupv2-test_cgrp2_sock"
+
+################################################################################
+#
+print_result()
+{
+	local rc=$1
+	local status=" OK "
+
+	[ $rc -ne 0 ] && status="FAIL"
+
+	printf "%-50s    [%4s]\n" "$2" "$status"
+}
+
+check_sock()
+{
+	out=$(test_cgrp2_sock)
+	echo $out | grep -q "$1"
+	if [ $? -ne 0 ]; then
+		print_result 1 "IPv4: $2"
+		echo "    expected: $1"
+		echo "        have: $out"
+		rc=1
+	else
+		print_result 0 "IPv4: $2"
+	fi
+}
+
+check_sock6()
+{
+	out=$(test_cgrp2_sock -6)
+	echo $out | grep -q "$1"
+	if [ $? -ne 0 ]; then
+		print_result 1 "IPv6: $2"
+		echo "    expected: $1"
+		echo "        have: $out"
+		rc=1
+	else
+		print_result 0 "IPv6: $2"
+	fi
+}
+
+################################################################################
+#
+
+cleanup()
+{
+	echo $$ >> ${CGRP_MNT}/cgroup.procs
+	rmdir ${CGRP_MNT}/sockopts
+}
+
+cleanup_and_exit()
+{
+	local rc=$1
+	local msg="$2"
+
+	[ -n "$msg" ] && echo "ERROR: $msg"
+
+	test_cgrp2_sock -d ${CGRP_MNT}/sockopts
+	ip li del cgrp2_sock
+	umount ${CGRP_MNT}
+
+	exit $rc
+}
+
+
+################################################################################
+# main
+
+rc=0
+
+ip li add cgrp2_sock type dummy 2>/dev/null
+
+set -e
+mkdir -p ${CGRP_MNT}
+mount -t cgroup2 none ${CGRP_MNT}
+set +e
+
+
+# make sure we have a known start point
+cleanup 2>/dev/null
+
+mkdir -p ${CGRP_MNT}/sockopts
+[ $? -ne 0 ] && cleanup_and_exit 1 "Failed to create cgroup hierarchy"
+
+
+# set pid into cgroup
+echo $$ > ${CGRP_MNT}/sockopts/cgroup.procs
+
+# no bpf program attached, so socket should show no settings
+check_sock "dev , mark 0, priority 0" "No programs attached"
+check_sock6 "dev , mark 0, priority 0" "No programs attached"
+
+# verify device is set
+#
+test_cgrp2_sock -b cgrp2_sock ${CGRP_MNT}/sockopts
+if [ $? -ne 0 ]; then
+	cleanup_and_exit 1 "Failed to install program to set device"
+fi
+check_sock "dev cgrp2_sock, mark 0, priority 0" "Device set"
+check_sock6 "dev cgrp2_sock, mark 0, priority 0" "Device set"
+
+# verify mark is set
+#
+test_cgrp2_sock -m 666 ${CGRP_MNT}/sockopts
+if [ $? -ne 0 ]; then
+	cleanup_and_exit 1 "Failed to install program to set mark"
+fi
+check_sock "dev , mark 666, priority 0" "Mark set"
+check_sock6 "dev , mark 666, priority 0" "Mark set"
+
+# verify priority is set
+#
+test_cgrp2_sock -p 123 ${CGRP_MNT}/sockopts
+if [ $? -ne 0 ]; then
+	cleanup_and_exit 1 "Failed to install program to set priority"
+fi
+check_sock "dev , mark 0, priority 123" "Priority set"
+check_sock6 "dev , mark 0, priority 123" "Priority set"
+
+# all 3 at once
+#
+test_cgrp2_sock -b cgrp2_sock -m 666 -p 123 ${CGRP_MNT}/sockopts
+if [ $? -ne 0 ]; then
+	cleanup_and_exit 1 "Failed to install program to set device, mark and priority"
+fi
+check_sock "dev cgrp2_sock, mark 666, priority 123" "Priority set"
+check_sock6 "dev cgrp2_sock, mark 666, priority 123" "Priority set"
+
+cleanup_and_exit $rc
diff --git a/samples/bpf/test_cgrp2_sock2.c b/samples/bpf/test_cgrp2_sock2.c
new file mode 100644
index 000000000..a9277b118
--- /dev/null
+++ b/samples/bpf/test_cgrp2_sock2.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/* eBPF example program:
+ *
+ * - Loads eBPF program
+ *
+ *   The eBPF program loads a filter from file and attaches the
+ *   program to a cgroup using BPF_PROG_ATTACH
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <unistd.h>
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <net/if.h>
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+
+#include "bpf_insn.h"
+#include "bpf_load.h"
+
+static int usage(const char *argv0)
+{
+	printf("Usage: %s cg-path filter-path [filter-id]\n", argv0);
+	return EXIT_FAILURE;
+}
+
+int main(int argc, char **argv)
+{
+	int cg_fd, ret, filter_id = 0;
+
+	if (argc < 3)
+		return usage(argv[0]);
+
+	cg_fd = open(argv[1], O_DIRECTORY | O_RDONLY);
+	if (cg_fd < 0) {
+		printf("Failed to open cgroup path: '%s'\n", strerror(errno));
+		return EXIT_FAILURE;
+	}
+
+	if (load_bpf_file(argv[2]))
+		return EXIT_FAILURE;
+
+	printf("Output from kernel verifier:\n%s\n-------\n", bpf_log_buf);
+
+	if (argc > 3)
+		filter_id = atoi(argv[3]);
+
+	if (filter_id >= prog_cnt) {
+		printf("Invalid program id; program not found in file\n");
+		return EXIT_FAILURE;
+	}
+
+	ret = bpf_prog_attach(prog_fd[filter_id], cg_fd,
+			      BPF_CGROUP_INET_SOCK_CREATE, 0);
+	if (ret < 0) {
+		printf("Failed to attach prog to cgroup: '%s'\n",
+		       strerror(errno));
+		return EXIT_FAILURE;
+	}
+
+	return EXIT_SUCCESS;
+}
diff --git a/samples/bpf/test_cgrp2_sock2.sh b/samples/bpf/test_cgrp2_sock2.sh
new file mode 100755
index 000000000..0f396a86e
--- /dev/null
+++ b/samples/bpf/test_cgrp2_sock2.sh
@@ -0,0 +1,85 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+function config_device {
+	ip netns add at_ns0
+	ip link add veth0 type veth peer name veth0b
+	ip link set veth0b up
+	ip link set veth0 netns at_ns0
+	ip netns exec at_ns0 ip addr add 172.16.1.100/24 dev veth0
+	ip netns exec at_ns0 ip addr add 2401:db00::1/64 dev veth0 nodad
+	ip netns exec at_ns0 ip link set dev veth0 up
+	ip addr add 172.16.1.101/24 dev veth0b
+	ip addr add 2401:db00::2/64 dev veth0b nodad
+}
+
+function config_cgroup {
+	rm -rf /tmp/cgroupv2
+	mkdir -p /tmp/cgroupv2
+	mount -t cgroup2 none /tmp/cgroupv2
+	mkdir -p /tmp/cgroupv2/foo
+	echo $$ >> /tmp/cgroupv2/foo/cgroup.procs
+}
+
+
+function attach_bpf {
+	test_cgrp2_sock2 /tmp/cgroupv2/foo sock_flags_kern.o $1
+	[ $? -ne 0 ] && exit 1
+}
+
+function cleanup {
+	if [ -d /tmp/cgroupv2/foo ]; then
+		test_cgrp2_sock -d /tmp/cgroupv2/foo
+	fi
+	ip link del veth0b
+	ip netns delete at_ns0
+	umount /tmp/cgroupv2
+	rm -rf /tmp/cgroupv2
+}
+
+cleanup 2>/dev/null
+
+set -e
+config_device
+config_cgroup
+set +e
+
+#
+# Test 1 - fail ping6
+#
+attach_bpf 0
+ping -c1 -w1 172.16.1.100
+if [ $? -ne 0 ]; then
+	echo "ping failed when it should succeed"
+	cleanup
+	exit 1
+fi
+
+ping6 -c1 -w1 2401:db00::1
+if [ $? -eq 0 ]; then
+	echo "ping6 succeeded when it should not"
+	cleanup
+	exit 1
+fi
+
+#
+# Test 2 - fail ping
+#
+attach_bpf 1
+ping6 -c1 -w1 2401:db00::1
+if [ $? -ne 0 ]; then
+	echo "ping6 failed when it should succeed"
+	cleanup
+	exit 1
+fi
+
+ping -c1 -w1 172.16.1.100
+if [ $? -eq 0 ]; then
+	echo "ping succeeded when it should not"
+	cleanup
+	exit 1
+fi
+
+cleanup
+echo
+echo "*** PASS ***"
diff --git a/samples/bpf/test_cgrp2_tc.sh b/samples/bpf/test_cgrp2_tc.sh
new file mode 100755
index 000000000..12faf5847
--- /dev/null
+++ b/samples/bpf/test_cgrp2_tc.sh
@@ -0,0 +1,185 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+MY_DIR=$(dirname $0)
+# Details on the bpf prog
+BPF_CGRP2_ARRAY_NAME='test_cgrp2_array_pin'
+BPF_PROG="$MY_DIR/test_cgrp2_tc_kern.o"
+BPF_SECTION='filter'
+
+[ -z "$TC" ] && TC='tc'
+[ -z "$IP" ] && IP='ip'
+
+# Names of the veth interface, net namespace...etc.
+HOST_IFC='ve'
+NS_IFC='vens'
+NS='ns'
+
+find_mnt() {
+    cat /proc/mounts | \
+	awk '{ if ($3 == "'$1'" && mnt == "") { mnt = $2 }} END { print mnt }'
+}
+
+# Init cgroup2 vars
+init_cgrp2_vars() {
+    CGRP2_ROOT=$(find_mnt cgroup2)
+    if [ -z "$CGRP2_ROOT" ]
+    then
+	CGRP2_ROOT='/mnt/cgroup2'
+	MOUNT_CGRP2="yes"
+    fi
+    CGRP2_TC="$CGRP2_ROOT/tc"
+    CGRP2_TC_LEAF="$CGRP2_TC/leaf"
+}
+
+# Init bpf fs vars
+init_bpf_fs_vars() {
+    local bpf_fs_root=$(find_mnt bpf)
+    [ -n "$bpf_fs_root" ] || return -1
+    BPF_FS_TC_SHARE="$bpf_fs_root/tc/globals"
+}
+
+setup_cgrp2() {
+    case $1 in
+	start)
+	    if [ "$MOUNT_CGRP2" == 'yes' ]
+	    then
+		[ -d $CGRP2_ROOT ] || mkdir -p $CGRP2_ROOT
+		mount -t cgroup2 none $CGRP2_ROOT || return $?
+	    fi
+	    mkdir -p $CGRP2_TC_LEAF
+	    ;;
+	*)
+	    rmdir $CGRP2_TC_LEAF && rmdir $CGRP2_TC
+	    [ "$MOUNT_CGRP2" == 'yes' ] && umount $CGRP2_ROOT
+	    ;;
+    esac
+}
+
+setup_bpf_cgrp2_array() {
+    local bpf_cgrp2_array="$BPF_FS_TC_SHARE/$BPF_CGRP2_ARRAY_NAME"
+    case $1 in
+	start)
+	    $MY_DIR/test_cgrp2_array_pin -U $bpf_cgrp2_array -v $CGRP2_TC
+	    ;;
+	*)
+	    [ -d "$BPF_FS_TC_SHARE" ] && rm -f $bpf_cgrp2_array
+	    ;;
+    esac
+}
+
+setup_net() {
+    case $1 in
+	start)
+	    $IP link add $HOST_IFC type veth peer name $NS_IFC || return $?
+	    $IP link set dev $HOST_IFC up || return $?
+	    sysctl -q net.ipv6.conf.$HOST_IFC.accept_dad=0
+
+	    $IP netns add ns || return $?
+	    $IP link set dev $NS_IFC netns ns || return $?
+	    $IP -n $NS link set dev $NS_IFC up || return $?
+	    $IP netns exec $NS sysctl -q net.ipv6.conf.$NS_IFC.accept_dad=0
+	    $TC qdisc add dev $HOST_IFC clsact || return $?
+	    $TC filter add dev $HOST_IFC egress bpf da obj $BPF_PROG sec $BPF_SECTION || return $?
+	    ;;
+	*)
+	    $IP netns del $NS
+	    $IP link del $HOST_IFC
+	    ;;
+    esac
+}
+
+run_in_cgrp() {
+    # Fork another bash and move it under the specified cgroup.
+    # It makes the cgroup cleanup easier at the end of the test.
+    cmd='echo $$ > '
+    cmd="$cmd $1/cgroup.procs; exec $2"
+    bash -c "$cmd"
+}
+
+do_test() {
+    run_in_cgrp $CGRP2_TC_LEAF "ping -6 -c3 ff02::1%$HOST_IFC >& /dev/null"
+    local dropped=$($TC -s qdisc show dev $HOST_IFC | tail -3 | \
+			   awk '/drop/{print substr($7, 0, index($7, ",")-1)}')
+    if [[ $dropped -eq 0 ]]
+    then
+	echo "FAIL"
+	return 1
+    else
+	echo "Successfully filtered $dropped packets"
+	return 0
+    fi
+}
+
+do_exit() {
+    if [ "$DEBUG" == "yes" ] && [ "$MODE" != 'cleanuponly' ]
+    then
+	echo "------ DEBUG ------"
+	echo "mount: "; mount | egrep '(cgroup2|bpf)'; echo
+	echo "$CGRP2_TC_LEAF: "; ls -l $CGRP2_TC_LEAF; echo
+	if [ -d "$BPF_FS_TC_SHARE" ]
+	then
+	    echo "$BPF_FS_TC_SHARE: "; ls -l $BPF_FS_TC_SHARE; echo
+	fi
+	echo "Host net:"
+	$IP netns
+	$IP link show dev $HOST_IFC
+	$IP -6 a show dev $HOST_IFC
+	$TC -s qdisc show dev $HOST_IFC
+	echo
+	echo "$NS net:"
+	$IP -n $NS link show dev $NS_IFC
+	$IP -n $NS -6 link show dev $NS_IFC
+	echo "------ DEBUG ------"
+	echo
+    fi
+
+    if [ "$MODE" != 'nocleanup' ]
+    then
+	setup_net stop
+	setup_bpf_cgrp2_array stop
+	setup_cgrp2 stop
+    fi
+}
+
+init_cgrp2_vars
+init_bpf_fs_vars
+
+while [[ $# -ge 1 ]]
+do
+    a="$1"
+    case $a in
+	debug)
+	    DEBUG='yes'
+	    shift 1
+	    ;;
+	cleanup-only)
+	    MODE='cleanuponly'
+	    shift 1
+	    ;;
+	no-cleanup)
+	    MODE='nocleanup'
+	    shift 1
+	    ;;
+	*)
+	    echo "test_cgrp2_tc [debug] [cleanup-only | no-cleanup]"
+	    echo "  debug: Print cgrp and network setup details at the end of the test"
+	    echo "  cleanup-only: Try to cleanup things from last test.  No test will be run"
+	    echo "  no-cleanup: Run the test but don't do cleanup at the end"
+	    echo "[Note: If no arg is given, it will run the test and do cleanup at the end]"
+	    echo
+	    exit -1
+	    ;;
+    esac
+done
+
+trap do_exit 0
+
+[ "$MODE" == 'cleanuponly' ] && exit
+
+setup_cgrp2 start || exit $?
+setup_net start || exit $?
+init_bpf_fs_vars || exit $?
+setup_bpf_cgrp2_array start || exit $?
+do_test
+echo
diff --git a/samples/bpf/test_cgrp2_tc_kern.c b/samples/bpf/test_cgrp2_tc_kern.c
new file mode 100644
index 000000000..4dd532a31
--- /dev/null
+++ b/samples/bpf/test_cgrp2_tc_kern.c
@@ -0,0 +1,70 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/in6.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/pkt_cls.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+/* copy of 'struct ethhdr' without __packed */
+struct eth_hdr {
+	unsigned char   h_dest[ETH_ALEN];
+	unsigned char   h_source[ETH_ALEN];
+	unsigned short  h_proto;
+};
+
+#define PIN_GLOBAL_NS		2
+struct bpf_elf_map {
+	__u32 type;
+	__u32 size_key;
+	__u32 size_value;
+	__u32 max_elem;
+	__u32 flags;
+	__u32 id;
+	__u32 pinning;
+};
+
+struct bpf_elf_map SEC("maps") test_cgrp2_array_pin = {
+	.type		= BPF_MAP_TYPE_CGROUP_ARRAY,
+	.size_key	= sizeof(uint32_t),
+	.size_value	= sizeof(uint32_t),
+	.pinning	= PIN_GLOBAL_NS,
+	.max_elem	= 1,
+};
+
+SEC("filter")
+int handle_egress(struct __sk_buff *skb)
+{
+	void *data = (void *)(long)skb->data;
+	struct eth_hdr *eth = data;
+	struct ipv6hdr *ip6h = data + sizeof(*eth);
+	void *data_end = (void *)(long)skb->data_end;
+	char dont_care_msg[] = "dont care %04x %d\n";
+	char pass_msg[] = "pass\n";
+	char reject_msg[] = "reject\n";
+
+	/* single length check */
+	if (data + sizeof(*eth) + sizeof(*ip6h) > data_end)
+		return TC_ACT_OK;
+
+	if (eth->h_proto != htons(ETH_P_IPV6) ||
+	    ip6h->nexthdr != IPPROTO_ICMPV6) {
+		bpf_trace_printk(dont_care_msg, sizeof(dont_care_msg),
+				 eth->h_proto, ip6h->nexthdr);
+		return TC_ACT_OK;
+	} else if (bpf_skb_under_cgroup(skb, &test_cgrp2_array_pin, 0) != 1) {
+		bpf_trace_printk(pass_msg, sizeof(pass_msg));
+		return TC_ACT_OK;
+	} else {
+		bpf_trace_printk(reject_msg, sizeof(reject_msg));
+		return TC_ACT_SHOT;
+	}
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/test_cls_bpf.sh b/samples/bpf/test_cls_bpf.sh
new file mode 100755
index 000000000..aaddd67b3
--- /dev/null
+++ b/samples/bpf/test_cls_bpf.sh
@@ -0,0 +1,38 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+function pktgen {
+    ../pktgen/pktgen_bench_xmit_mode_netif_receive.sh -i $IFC -s 64 \
+        -m 90:e2:ba:ff:ff:ff -d 192.168.0.1 -t 4
+    local dropped=`tc -s qdisc show dev $IFC | tail -3 | awk '/drop/{print $7}'`
+    if [ "$dropped" == "0," ]; then
+        echo "FAIL"
+    else
+        echo "Successfully filtered " $dropped " packets"
+    fi
+}
+
+function test {
+    echo -n "Loading bpf program '$2'... "
+    tc qdisc add dev $IFC clsact
+    tc filter add dev $IFC ingress bpf da obj $1 sec $2
+    local status=$?
+    if [ $status -ne 0 ]; then
+        echo "FAIL"
+    else
+        echo "ok"
+	pktgen
+    fi
+    tc qdisc del dev $IFC clsact
+}
+
+IFC=test_veth
+
+ip link add name $IFC type veth peer name pair_$IFC
+ip link set $IFC up
+ip link set pair_$IFC up
+
+test ./parse_simple.o simple
+test ./parse_varlen.o varlen
+test ./parse_ldabs.o ldabs
+ip link del dev $IFC
diff --git a/samples/bpf/test_current_task_under_cgroup_kern.c b/samples/bpf/test_current_task_under_cgroup_kern.c
new file mode 100644
index 000000000..fbd43e2bb
--- /dev/null
+++ b/samples/bpf/test_current_task_under_cgroup_kern.c
@@ -0,0 +1,44 @@
+/* Copyright (c) 2016 Sargun Dhillon <sargun@sargun.me>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <uapi/linux/utsname.h>
+#include "trace_common.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_CGROUP_ARRAY);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, sizeof(u32));
+	__uint(max_entries, 1);
+} cgroup_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u64);
+	__uint(max_entries, 1);
+} perf_map SEC(".maps");
+
+/* Writes the last PID that called sync to a map at index 0 */
+SEC("kprobe/" SYSCALL(sys_sync))
+int bpf_prog1(struct pt_regs *ctx)
+{
+	u64 pid = bpf_get_current_pid_tgid();
+	int idx = 0;
+
+	if (!bpf_current_task_under_cgroup(&cgroup_map, 0))
+		return 0;
+
+	bpf_map_update_elem(&perf_map, &idx, &pid, BPF_ANY);
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/test_current_task_under_cgroup_user.c b/samples/bpf/test_current_task_under_cgroup_user.c
new file mode 100644
index 000000000..ac251a417
--- /dev/null
+++ b/samples/bpf/test_current_task_under_cgroup_user.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Sargun Dhillon <sargun@sargun.me>
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <unistd.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "cgroup_helpers.h"
+
+#define CGROUP_PATH		"/my-cgroup"
+
+int main(int argc, char **argv)
+{
+	pid_t remote_pid, local_pid = getpid();
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	int cg2, idx = 0, rc = 1;
+	struct bpf_object *obj;
+	char filename[256];
+	int map_fd[2];
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (!prog) {
+		printf("finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "cgroup_map");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "perf_map");
+	if (map_fd[0] < 0 || map_fd[1] < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	if (setup_cgroup_environment())
+		goto err;
+
+	cg2 = create_and_get_cgroup(CGROUP_PATH);
+
+	if (cg2 < 0)
+		goto err;
+
+	if (bpf_map_update_elem(map_fd[0], &idx, &cg2, BPF_ANY)) {
+		log_err("Adding target cgroup to map");
+		goto err;
+	}
+
+	if (join_cgroup(CGROUP_PATH))
+		goto err;
+
+	/*
+	 * The installed helper program catched the sync call, and should
+	 * write it to the map.
+	 */
+
+	sync();
+	bpf_map_lookup_elem(map_fd[1], &idx, &remote_pid);
+
+	if (local_pid != remote_pid) {
+		fprintf(stderr,
+			"BPF Helper didn't write correct PID to map, but: %d\n",
+			remote_pid);
+		goto err;
+	}
+
+	/* Verify the negative scenario; leave the cgroup */
+	if (join_cgroup("/"))
+		goto err;
+
+	remote_pid = 0;
+	bpf_map_update_elem(map_fd[1], &idx, &remote_pid, BPF_ANY);
+
+	sync();
+	bpf_map_lookup_elem(map_fd[1], &idx, &remote_pid);
+
+	if (local_pid == remote_pid) {
+		fprintf(stderr, "BPF cgroup negative test did not work\n");
+		goto err;
+	}
+
+	rc = 0;
+
+err:
+	close(cg2);
+	cleanup_cgroup_environment();
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return rc;
+}
diff --git a/samples/bpf/test_ipip.sh b/samples/bpf/test_ipip.sh
new file mode 100755
index 000000000..9e507c305
--- /dev/null
+++ b/samples/bpf/test_ipip.sh
@@ -0,0 +1,179 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+function config_device {
+	ip netns add at_ns0
+	ip netns add at_ns1
+	ip netns add at_ns2
+	ip link add veth0 type veth peer name veth0b
+	ip link add veth1 type veth peer name veth1b
+	ip link add veth2 type veth peer name veth2b
+	ip link set veth0b up
+	ip link set veth1b up
+	ip link set veth2b up
+	ip link set dev veth0b mtu 1500
+	ip link set dev veth1b mtu 1500
+	ip link set dev veth2b mtu 1500
+	ip link set veth0 netns at_ns0
+	ip link set veth1 netns at_ns1
+	ip link set veth2 netns at_ns2
+	ip netns exec at_ns0 ip addr add 172.16.1.100/24 dev veth0
+	ip netns exec at_ns0 ip addr add 2401:db00::1/64 dev veth0 nodad
+	ip netns exec at_ns0 ip link set dev veth0 up
+	ip netns exec at_ns1 ip addr add 172.16.1.101/24 dev veth1
+	ip netns exec at_ns1 ip addr add 2401:db00::2/64 dev veth1 nodad
+	ip netns exec at_ns1 ip link set dev veth1 up
+	ip netns exec at_ns2 ip addr add 172.16.1.200/24 dev veth2
+	ip netns exec at_ns2 ip addr add 2401:db00::3/64 dev veth2 nodad
+	ip netns exec at_ns2 ip link set dev veth2 up
+	ip link add br0 type bridge
+	ip link set br0 up
+	ip link set dev br0 mtu 1500
+	ip link set veth0b master br0
+	ip link set veth1b master br0
+	ip link set veth2b master br0
+}
+
+function add_ipip_tunnel {
+	ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type ipip local 172.16.1.100 remote 172.16.1.200
+	ip netns exec at_ns0 ip link set dev $DEV_NS up
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
+	ip netns exec at_ns1 \
+		ip link add dev $DEV_NS type ipip local 172.16.1.101 remote 172.16.1.200
+	ip netns exec at_ns1 ip link set dev $DEV_NS up
+	# same inner IP address in at_ns0 and at_ns1
+	ip netns exec at_ns1 ip addr add dev $DEV_NS 10.1.1.100/24
+
+	ip netns exec at_ns2 ip link add dev $DEV type ipip external
+	ip netns exec at_ns2 ip link set dev $DEV up
+	ip netns exec at_ns2 ip addr add dev $DEV 10.1.1.200/24
+}
+
+function add_ipip6_tunnel {
+	ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type ip6tnl mode ipip6 local 2401:db00::1/64 remote 2401:db00::3/64
+	ip netns exec at_ns0 ip link set dev $DEV_NS up
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 10.1.1.100/24
+	ip netns exec at_ns1 \
+		ip link add dev $DEV_NS type ip6tnl mode ipip6 local 2401:db00::2/64 remote 2401:db00::3/64
+	ip netns exec at_ns1 ip link set dev $DEV_NS up
+	# same inner IP address in at_ns0 and at_ns1
+	ip netns exec at_ns1 ip addr add dev $DEV_NS 10.1.1.100/24
+
+	ip netns exec at_ns2 ip link add dev $DEV type ip6tnl mode ipip6 external
+	ip netns exec at_ns2 ip link set dev $DEV up
+	ip netns exec at_ns2 ip addr add dev $DEV 10.1.1.200/24
+}
+
+function add_ip6ip6_tunnel {
+	ip netns exec at_ns0 \
+		ip link add dev $DEV_NS type ip6tnl mode ip6ip6 local 2401:db00::1/64 remote 2401:db00::3/64
+	ip netns exec at_ns0 ip link set dev $DEV_NS up
+	ip netns exec at_ns0 ip addr add dev $DEV_NS 2601:646::1/64
+	ip netns exec at_ns1 \
+		ip link add dev $DEV_NS type ip6tnl mode ip6ip6 local 2401:db00::2/64 remote 2401:db00::3/64
+	ip netns exec at_ns1 ip link set dev $DEV_NS up
+	# same inner IP address in at_ns0 and at_ns1
+	ip netns exec at_ns1 ip addr add dev $DEV_NS 2601:646::1/64
+
+	ip netns exec at_ns2 ip link add dev $DEV type ip6tnl mode ip6ip6 external
+	ip netns exec at_ns2 ip link set dev $DEV up
+	ip netns exec at_ns2 ip addr add dev $DEV 2601:646::2/64
+}
+
+function attach_bpf {
+	DEV=$1
+	SET_TUNNEL=$2
+	GET_TUNNEL=$3
+	ip netns exec at_ns2 tc qdisc add dev $DEV clsact
+	ip netns exec at_ns2 tc filter add dev $DEV egress bpf da obj tcbpf2_kern.o sec $SET_TUNNEL
+	ip netns exec at_ns2 tc filter add dev $DEV ingress bpf da obj tcbpf2_kern.o sec $GET_TUNNEL
+}
+
+function test_ipip {
+	DEV_NS=ipip_std
+	DEV=ipip_bpf
+	config_device
+#	tcpdump -nei br0 &
+	cat /sys/kernel/debug/tracing/trace_pipe &
+
+	add_ipip_tunnel
+	attach_bpf $DEV ipip_set_tunnel ipip_get_tunnel
+
+	ip netns exec at_ns0 ping -c 1 10.1.1.200
+	ip netns exec at_ns2 ping -c 1 10.1.1.100
+	ip netns exec at_ns0 iperf -sD -p 5200 > /dev/null
+	ip netns exec at_ns1 iperf -sD -p 5201 > /dev/null
+	sleep 0.2
+	# tcp check _same_ IP over different tunnels
+	ip netns exec at_ns2 iperf -c 10.1.1.100 -n 5k -p 5200
+	ip netns exec at_ns2 iperf -c 10.1.1.100 -n 5k -p 5201
+	cleanup
+}
+
+# IPv4 over IPv6 tunnel
+function test_ipip6 {
+	DEV_NS=ipip_std
+	DEV=ipip_bpf
+	config_device
+#	tcpdump -nei br0 &
+	cat /sys/kernel/debug/tracing/trace_pipe &
+
+	add_ipip6_tunnel
+	attach_bpf $DEV ipip6_set_tunnel ipip6_get_tunnel
+
+	ip netns exec at_ns0 ping -c 1 10.1.1.200
+	ip netns exec at_ns2 ping -c 1 10.1.1.100
+	ip netns exec at_ns0 iperf -sD -p 5200 > /dev/null
+	ip netns exec at_ns1 iperf -sD -p 5201 > /dev/null
+	sleep 0.2
+	# tcp check _same_ IP over different tunnels
+	ip netns exec at_ns2 iperf -c 10.1.1.100 -n 5k -p 5200
+	ip netns exec at_ns2 iperf -c 10.1.1.100 -n 5k -p 5201
+	cleanup
+}
+
+# IPv6 over IPv6 tunnel
+function test_ip6ip6 {
+	DEV_NS=ipip_std
+	DEV=ipip_bpf
+	config_device
+#	tcpdump -nei br0 &
+	cat /sys/kernel/debug/tracing/trace_pipe &
+
+	add_ip6ip6_tunnel
+	attach_bpf $DEV ip6ip6_set_tunnel ip6ip6_get_tunnel
+
+	ip netns exec at_ns0 ping -6 -c 1 2601:646::2
+	ip netns exec at_ns2 ping -6 -c 1 2601:646::1
+	ip netns exec at_ns0 iperf -6sD -p 5200 > /dev/null
+	ip netns exec at_ns1 iperf -6sD -p 5201 > /dev/null
+	sleep 0.2
+	# tcp check _same_ IP over different tunnels
+	ip netns exec at_ns2 iperf -6c 2601:646::1 -n 5k -p 5200
+	ip netns exec at_ns2 iperf -6c 2601:646::1 -n 5k -p 5201
+	cleanup
+}
+
+function cleanup {
+	set +ex
+	pkill iperf
+	ip netns delete at_ns0
+	ip netns delete at_ns1
+	ip netns delete at_ns2
+	ip link del veth0
+	ip link del veth1
+	ip link del veth2
+	ip link del br0
+	pkill tcpdump
+	pkill cat
+	set -ex
+}
+
+cleanup
+echo "Testing IP tunnels..."
+test_ipip
+test_ipip6
+test_ip6ip6
+echo "*** PASS ***"
diff --git a/samples/bpf/test_lru_dist.c b/samples/bpf/test_lru_dist.c
new file mode 100644
index 000000000..b313dba41
--- /dev/null
+++ b/samples/bpf/test_lru_dist.c
@@ -0,0 +1,540 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2016 Facebook
+ */
+#define _GNU_SOURCE
+#include <linux/types.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <linux/bpf.h>
+#include <errno.h>
+#include <string.h>
+#include <assert.h>
+#include <sched.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <sys/resource.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include <bpf/bpf.h>
+#include "bpf_util.h"
+
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#ifndef offsetof
+# define offsetof(TYPE, MEMBER)	((size_t)&((TYPE *)0)->MEMBER)
+#endif
+#define container_of(ptr, type, member) ({			\
+	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
+	(type *)( (char *)__mptr - offsetof(type,member) );})
+
+static int nr_cpus;
+static unsigned long long *dist_keys;
+static unsigned int dist_key_counts;
+
+struct list_head {
+	struct list_head *next, *prev;
+};
+
+static inline void INIT_LIST_HEAD(struct list_head *list)
+{
+	list->next = list;
+	list->prev = list;
+}
+
+static inline int list_empty(const struct list_head *head)
+{
+	return head->next == head;
+}
+
+static inline void __list_add(struct list_head *new,
+			      struct list_head *prev,
+			      struct list_head *next)
+{
+	next->prev = new;
+	new->next = next;
+	new->prev = prev;
+	prev->next = new;
+}
+
+static inline void list_add(struct list_head *new, struct list_head *head)
+{
+	__list_add(new, head, head->next);
+}
+
+static inline void __list_del(struct list_head *prev, struct list_head *next)
+{
+	next->prev = prev;
+	prev->next = next;
+}
+
+static inline void __list_del_entry(struct list_head *entry)
+{
+	__list_del(entry->prev, entry->next);
+}
+
+static inline void list_move(struct list_head *list, struct list_head *head)
+{
+	__list_del_entry(list);
+	list_add(list, head);
+}
+
+#define list_entry(ptr, type, member) \
+	container_of(ptr, type, member)
+
+#define list_last_entry(ptr, type, member) \
+	list_entry((ptr)->prev, type, member)
+
+struct pfect_lru_node {
+	struct list_head list;
+	unsigned long long key;
+};
+
+struct pfect_lru {
+	struct list_head list;
+	struct pfect_lru_node *free_nodes;
+	unsigned int cur_size;
+	unsigned int lru_size;
+	unsigned int nr_unique;
+	unsigned int nr_misses;
+	unsigned int total;
+	int map_fd;
+};
+
+static void pfect_lru_init(struct pfect_lru *lru, unsigned int lru_size,
+			   unsigned int nr_possible_elems)
+{
+	lru->map_fd = bpf_create_map(BPF_MAP_TYPE_HASH,
+				     sizeof(unsigned long long),
+				     sizeof(struct pfect_lru_node *),
+				     nr_possible_elems, 0);
+	assert(lru->map_fd != -1);
+
+	lru->free_nodes = malloc(lru_size * sizeof(struct pfect_lru_node));
+	assert(lru->free_nodes);
+
+	INIT_LIST_HEAD(&lru->list);
+	lru->cur_size = 0;
+	lru->lru_size = lru_size;
+	lru->nr_unique = lru->nr_misses = lru->total = 0;
+}
+
+static void pfect_lru_destroy(struct pfect_lru *lru)
+{
+	close(lru->map_fd);
+	free(lru->free_nodes);
+}
+
+static int pfect_lru_lookup_or_insert(struct pfect_lru *lru,
+				      unsigned long long key)
+{
+	struct pfect_lru_node *node = NULL;
+	int seen = 0;
+
+	lru->total++;
+	if (!bpf_map_lookup_elem(lru->map_fd, &key, &node)) {
+		if (node) {
+			list_move(&node->list, &lru->list);
+			return 1;
+		}
+		seen = 1;
+	}
+
+	if (lru->cur_size < lru->lru_size) {
+		node =  &lru->free_nodes[lru->cur_size++];
+		INIT_LIST_HEAD(&node->list);
+	} else {
+		struct pfect_lru_node *null_node = NULL;
+
+		node = list_last_entry(&lru->list,
+				       struct pfect_lru_node,
+				       list);
+		bpf_map_update_elem(lru->map_fd, &node->key, &null_node, BPF_EXIST);
+	}
+
+	node->key = key;
+	list_move(&node->list, &lru->list);
+
+	lru->nr_misses++;
+	if (seen) {
+		assert(!bpf_map_update_elem(lru->map_fd, &key, &node, BPF_EXIST));
+	} else {
+		lru->nr_unique++;
+		assert(!bpf_map_update_elem(lru->map_fd, &key, &node, BPF_NOEXIST));
+	}
+
+	return seen;
+}
+
+static unsigned int read_keys(const char *dist_file,
+			      unsigned long long **keys)
+{
+	struct stat fst;
+	unsigned long long *retkeys;
+	unsigned int counts = 0;
+	int dist_fd;
+	char *b, *l;
+	int i;
+
+	dist_fd = open(dist_file, 0);
+	assert(dist_fd != -1);
+
+	assert(fstat(dist_fd, &fst) == 0);
+	b = malloc(fst.st_size);
+	assert(b);
+
+	assert(read(dist_fd, b, fst.st_size) == fst.st_size);
+	close(dist_fd);
+	for (i = 0; i < fst.st_size; i++) {
+		if (b[i] == '\n')
+			counts++;
+	}
+	counts++; /* in case the last line has no \n */
+
+	retkeys = malloc(counts * sizeof(unsigned long long));
+	assert(retkeys);
+
+	counts = 0;
+	for (l = strtok(b, "\n"); l; l = strtok(NULL, "\n"))
+		retkeys[counts++] = strtoull(l, NULL, 10);
+	free(b);
+
+	*keys = retkeys;
+
+	return counts;
+}
+
+static int create_map(int map_type, int map_flags, unsigned int size)
+{
+	int map_fd;
+
+	map_fd = bpf_create_map(map_type, sizeof(unsigned long long),
+				sizeof(unsigned long long), size, map_flags);
+
+	if (map_fd == -1)
+		perror("bpf_create_map");
+
+	return map_fd;
+}
+
+static int sched_next_online(int pid, int next_to_try)
+{
+	cpu_set_t cpuset;
+
+	if (next_to_try == nr_cpus)
+		return -1;
+
+	while (next_to_try < nr_cpus) {
+		CPU_ZERO(&cpuset);
+		CPU_SET(next_to_try++, &cpuset);
+		if (!sched_setaffinity(pid, sizeof(cpuset), &cpuset))
+			break;
+	}
+
+	return next_to_try;
+}
+
+static void run_parallel(unsigned int tasks, void (*fn)(int i, void *data),
+			 void *data)
+{
+	int next_sched_cpu = 0;
+	pid_t pid[tasks];
+	int i;
+
+	for (i = 0; i < tasks; i++) {
+		pid[i] = fork();
+		if (pid[i] == 0) {
+			next_sched_cpu = sched_next_online(0, next_sched_cpu);
+			fn(i, data);
+			exit(0);
+		} else if (pid[i] == -1) {
+			printf("couldn't spawn #%d process\n", i);
+			exit(1);
+		}
+		/* It is mostly redundant and just allow the parent
+		 * process to update next_shced_cpu for the next child
+		 * process
+		 */
+		next_sched_cpu = sched_next_online(pid[i], next_sched_cpu);
+	}
+	for (i = 0; i < tasks; i++) {
+		int status;
+
+		assert(waitpid(pid[i], &status, 0) == pid[i]);
+		assert(status == 0);
+	}
+}
+
+static void do_test_lru_dist(int task, void *data)
+{
+	unsigned int nr_misses = 0;
+	struct pfect_lru pfect_lru;
+	unsigned long long key, value = 1234;
+	unsigned int i;
+
+	unsigned int lru_map_fd = ((unsigned int *)data)[0];
+	unsigned int lru_size = ((unsigned int *)data)[1];
+	unsigned long long key_offset = task * dist_key_counts;
+
+	pfect_lru_init(&pfect_lru, lru_size, dist_key_counts);
+
+	for (i = 0; i < dist_key_counts; i++) {
+		key = dist_keys[i] + key_offset;
+
+		pfect_lru_lookup_or_insert(&pfect_lru, key);
+
+		if (!bpf_map_lookup_elem(lru_map_fd, &key, &value))
+			continue;
+
+		if (bpf_map_update_elem(lru_map_fd, &key, &value, BPF_NOEXIST)) {
+			printf("bpf_map_update_elem(lru_map_fd, %llu): errno:%d\n",
+			       key, errno);
+			assert(0);
+		}
+
+		nr_misses++;
+	}
+
+	printf("    task:%d BPF LRU: nr_unique:%u(/%u) nr_misses:%u(/%u)\n",
+	       task, pfect_lru.nr_unique, dist_key_counts, nr_misses,
+	       dist_key_counts);
+	printf("    task:%d Perfect LRU: nr_unique:%u(/%u) nr_misses:%u(/%u)\n",
+	       task, pfect_lru.nr_unique, pfect_lru.total,
+	       pfect_lru.nr_misses, pfect_lru.total);
+
+	pfect_lru_destroy(&pfect_lru);
+	close(lru_map_fd);
+}
+
+static void test_parallel_lru_dist(int map_type, int map_flags,
+				   int nr_tasks, unsigned int lru_size)
+{
+	int child_data[2];
+	int lru_map_fd;
+
+	printf("%s (map_type:%d map_flags:0x%X):\n", __func__, map_type,
+	       map_flags);
+
+	if (map_flags & BPF_F_NO_COMMON_LRU)
+		lru_map_fd = create_map(map_type, map_flags,
+					nr_cpus * lru_size);
+	else
+		lru_map_fd = create_map(map_type, map_flags,
+					nr_tasks * lru_size);
+	assert(lru_map_fd != -1);
+
+	child_data[0] = lru_map_fd;
+	child_data[1] = lru_size;
+
+	run_parallel(nr_tasks, do_test_lru_dist, child_data);
+
+	close(lru_map_fd);
+}
+
+static void test_lru_loss0(int map_type, int map_flags)
+{
+	unsigned long long key, value[nr_cpus];
+	unsigned int old_unused_losses = 0;
+	unsigned int new_unused_losses = 0;
+	unsigned int used_losses = 0;
+	int map_fd;
+
+	printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
+	       map_flags);
+
+	assert(sched_next_online(0, 0) != -1);
+
+	if (map_flags & BPF_F_NO_COMMON_LRU)
+		map_fd = create_map(map_type, map_flags, 900 * nr_cpus);
+	else
+		map_fd = create_map(map_type, map_flags, 900);
+
+	assert(map_fd != -1);
+
+	value[0] = 1234;
+
+	for (key = 1; key <= 1000; key++) {
+		int start_key, end_key;
+
+		assert(bpf_map_update_elem(map_fd, &key, value, BPF_NOEXIST) == 0);
+
+		start_key = 101;
+		end_key = min(key, 900);
+
+		while (start_key <= end_key) {
+			bpf_map_lookup_elem(map_fd, &start_key, value);
+			start_key++;
+		}
+	}
+
+	for (key = 1; key <= 1000; key++) {
+		if (bpf_map_lookup_elem(map_fd, &key, value)) {
+			if (key <= 100)
+				old_unused_losses++;
+			else if (key <= 900)
+				used_losses++;
+			else
+				new_unused_losses++;
+		}
+	}
+
+	close(map_fd);
+
+	printf("older-elem-losses:%d(/100) active-elem-losses:%d(/800) "
+	       "newer-elem-losses:%d(/100)\n",
+	       old_unused_losses, used_losses, new_unused_losses);
+}
+
+static void test_lru_loss1(int map_type, int map_flags)
+{
+	unsigned long long key, value[nr_cpus];
+	int map_fd;
+	unsigned int nr_losses = 0;
+
+	printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
+	       map_flags);
+
+	assert(sched_next_online(0, 0) != -1);
+
+	if (map_flags & BPF_F_NO_COMMON_LRU)
+		map_fd = create_map(map_type, map_flags, 1000 * nr_cpus);
+	else
+		map_fd = create_map(map_type, map_flags, 1000);
+
+	assert(map_fd != -1);
+
+	value[0] = 1234;
+
+	for (key = 1; key <= 1000; key++)
+		assert(!bpf_map_update_elem(map_fd, &key, value, BPF_NOEXIST));
+
+	for (key = 1; key <= 1000; key++) {
+		if (bpf_map_lookup_elem(map_fd, &key, value))
+			nr_losses++;
+	}
+
+	close(map_fd);
+
+	printf("nr_losses:%d(/1000)\n", nr_losses);
+}
+
+static void do_test_parallel_lru_loss(int task, void *data)
+{
+	const unsigned int nr_stable_elems = 1000;
+	const unsigned int nr_repeats = 100000;
+
+	int map_fd = *(int *)data;
+	unsigned long long stable_base;
+	unsigned long long key, value[nr_cpus];
+	unsigned long long next_ins_key;
+	unsigned int nr_losses = 0;
+	unsigned int i;
+
+	stable_base = task * nr_repeats * 2 + 1;
+	next_ins_key = stable_base;
+	value[0] = 1234;
+	for (i = 0; i < nr_stable_elems; i++) {
+		assert(bpf_map_update_elem(map_fd, &next_ins_key, value,
+				       BPF_NOEXIST) == 0);
+		next_ins_key++;
+	}
+
+	for (i = 0; i < nr_repeats; i++) {
+		int rn;
+
+		rn = rand();
+
+		if (rn % 10) {
+			key = rn % nr_stable_elems + stable_base;
+			bpf_map_lookup_elem(map_fd, &key, value);
+		} else {
+			bpf_map_update_elem(map_fd, &next_ins_key, value,
+					BPF_NOEXIST);
+			next_ins_key++;
+		}
+	}
+
+	key = stable_base;
+	for (i = 0; i < nr_stable_elems; i++) {
+		if (bpf_map_lookup_elem(map_fd, &key, value))
+			nr_losses++;
+		key++;
+	}
+
+	printf("    task:%d nr_losses:%u\n", task, nr_losses);
+}
+
+static void test_parallel_lru_loss(int map_type, int map_flags, int nr_tasks)
+{
+	int map_fd;
+
+	printf("%s (map_type:%d map_flags:0x%X):\n", __func__, map_type,
+	       map_flags);
+
+	/* Give 20% more than the active working set */
+	if (map_flags & BPF_F_NO_COMMON_LRU)
+		map_fd = create_map(map_type, map_flags,
+				    nr_cpus * (1000 + 200));
+	else
+		map_fd = create_map(map_type, map_flags,
+				    nr_tasks * (1000 + 200));
+
+	assert(map_fd != -1);
+
+	run_parallel(nr_tasks, do_test_parallel_lru_loss, &map_fd);
+
+	close(map_fd);
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	int map_flags[] = {0, BPF_F_NO_COMMON_LRU};
+	const char *dist_file;
+	int nr_tasks = 1;
+	int lru_size;
+	int f;
+
+	if (argc < 4) {
+		printf("Usage: %s <dist-file> <lru-size> <nr-tasks>\n",
+		       argv[0]);
+		return -1;
+	}
+
+	dist_file = argv[1];
+	lru_size = atoi(argv[2]);
+	nr_tasks = atoi(argv[3]);
+
+	setbuf(stdout, NULL);
+
+	assert(!setrlimit(RLIMIT_MEMLOCK, &r));
+
+	srand(time(NULL));
+
+	nr_cpus = bpf_num_possible_cpus();
+	assert(nr_cpus != -1);
+	printf("nr_cpus:%d\n\n", nr_cpus);
+
+	nr_tasks = min(nr_tasks, nr_cpus);
+
+	dist_key_counts = read_keys(dist_file, &dist_keys);
+	if (!dist_key_counts) {
+		printf("%s has no key\n", dist_file);
+		return -1;
+	}
+
+	for (f = 0; f < sizeof(map_flags) / sizeof(*map_flags); f++) {
+		test_lru_loss0(BPF_MAP_TYPE_LRU_HASH, map_flags[f]);
+		test_lru_loss1(BPF_MAP_TYPE_LRU_HASH, map_flags[f]);
+		test_parallel_lru_loss(BPF_MAP_TYPE_LRU_HASH, map_flags[f],
+				       nr_tasks);
+		test_parallel_lru_dist(BPF_MAP_TYPE_LRU_HASH, map_flags[f],
+				       nr_tasks, lru_size);
+		printf("\n");
+	}
+
+	free(dist_keys);
+
+	return 0;
+}
diff --git a/samples/bpf/test_lwt_bpf.c b/samples/bpf/test_lwt_bpf.c
new file mode 100644
index 000000000..1b568575a
--- /dev/null
+++ b/samples/bpf/test_lwt_bpf.c
@@ -0,0 +1,253 @@
+/* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <stdint.h>
+#include <stddef.h>
+#include <linux/bpf.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/icmpv6.h>
+#include <linux/if_ether.h>
+#include <bpf/bpf_helpers.h>
+#include <string.h>
+
+# define printk(fmt, ...)						\
+		({							\
+			char ____fmt[] = fmt;				\
+			bpf_trace_printk(____fmt, sizeof(____fmt),	\
+				     ##__VA_ARGS__);			\
+		})
+
+#define CB_MAGIC 1234
+
+/* Test: Pass all packets through */
+SEC("nop")
+int do_nop(struct __sk_buff *skb)
+{
+	return BPF_OK;
+}
+
+/* Test: Verify context information can be accessed */
+SEC("test_ctx")
+int do_test_ctx(struct __sk_buff *skb)
+{
+	skb->cb[0] = CB_MAGIC;
+	printk("len %d hash %d protocol %d\n", skb->len, skb->hash,
+	       skb->protocol);
+	printk("cb %d ingress_ifindex %d ifindex %d\n", skb->cb[0],
+	       skb->ingress_ifindex, skb->ifindex);
+
+	return BPF_OK;
+}
+
+/* Test: Ensure skb->cb[] buffer is cleared */
+SEC("test_cb")
+int do_test_cb(struct __sk_buff *skb)
+{
+	printk("cb0: %x cb1: %x cb2: %x\n", skb->cb[0], skb->cb[1],
+	       skb->cb[2]);
+	printk("cb3: %x cb4: %x\n", skb->cb[3], skb->cb[4]);
+
+	return BPF_OK;
+}
+
+/* Test: Verify skb data can be read */
+SEC("test_data")
+int do_test_data(struct __sk_buff *skb)
+{
+	void *data = (void *)(long)skb->data;
+	void *data_end = (void *)(long)skb->data_end;
+	struct iphdr *iph = data;
+
+	if (data + sizeof(*iph) > data_end) {
+		printk("packet truncated\n");
+		return BPF_DROP;
+	}
+
+	printk("src: %x dst: %x\n", iph->saddr, iph->daddr);
+
+	return BPF_OK;
+}
+
+#define IP_CSUM_OFF offsetof(struct iphdr, check)
+#define IP_DST_OFF offsetof(struct iphdr, daddr)
+#define IP_SRC_OFF offsetof(struct iphdr, saddr)
+#define IP_PROTO_OFF offsetof(struct iphdr, protocol)
+#define TCP_CSUM_OFF offsetof(struct tcphdr, check)
+#define UDP_CSUM_OFF offsetof(struct udphdr, check)
+#define IS_PSEUDO 0x10
+
+static inline int rewrite(struct __sk_buff *skb, uint32_t old_ip,
+			  uint32_t new_ip, int rw_daddr)
+{
+	int ret, off = 0, flags = IS_PSEUDO;
+	uint8_t proto;
+
+	ret = bpf_skb_load_bytes(skb, IP_PROTO_OFF, &proto, 1);
+	if (ret < 0) {
+		printk("bpf_l4_csum_replace failed: %d\n", ret);
+		return BPF_DROP;
+	}
+
+	switch (proto) {
+	case IPPROTO_TCP:
+		off = TCP_CSUM_OFF;
+		break;
+
+	case IPPROTO_UDP:
+		off = UDP_CSUM_OFF;
+		flags |= BPF_F_MARK_MANGLED_0;
+		break;
+
+	case IPPROTO_ICMPV6:
+		off = offsetof(struct icmp6hdr, icmp6_cksum);
+		break;
+	}
+
+	if (off) {
+		ret = bpf_l4_csum_replace(skb, off, old_ip, new_ip,
+					  flags | sizeof(new_ip));
+		if (ret < 0) {
+			printk("bpf_l4_csum_replace failed: %d\n");
+			return BPF_DROP;
+		}
+	}
+
+	ret = bpf_l3_csum_replace(skb, IP_CSUM_OFF, old_ip, new_ip, sizeof(new_ip));
+	if (ret < 0) {
+		printk("bpf_l3_csum_replace failed: %d\n", ret);
+		return BPF_DROP;
+	}
+
+	if (rw_daddr)
+		ret = bpf_skb_store_bytes(skb, IP_DST_OFF, &new_ip, sizeof(new_ip), 0);
+	else
+		ret = bpf_skb_store_bytes(skb, IP_SRC_OFF, &new_ip, sizeof(new_ip), 0);
+
+	if (ret < 0) {
+		printk("bpf_skb_store_bytes() failed: %d\n", ret);
+		return BPF_DROP;
+	}
+
+	return BPF_OK;
+}
+
+/* Test: Verify skb data can be modified */
+SEC("test_rewrite")
+int do_test_rewrite(struct __sk_buff *skb)
+{
+	uint32_t old_ip, new_ip = 0x3fea8c0;
+	int ret;
+
+	ret = bpf_skb_load_bytes(skb, IP_DST_OFF, &old_ip, 4);
+	if (ret < 0) {
+		printk("bpf_skb_load_bytes failed: %d\n", ret);
+		return BPF_DROP;
+	}
+
+	if (old_ip == 0x2fea8c0) {
+		printk("out: rewriting from %x to %x\n", old_ip, new_ip);
+		return rewrite(skb, old_ip, new_ip, 1);
+	}
+
+	return BPF_OK;
+}
+
+static inline int __do_push_ll_and_redirect(struct __sk_buff *skb)
+{
+	uint64_t smac = SRC_MAC, dmac = DST_MAC;
+	int ret, ifindex = DST_IFINDEX;
+	struct ethhdr ehdr;
+
+	ret = bpf_skb_change_head(skb, 14, 0);
+	if (ret < 0) {
+		printk("skb_change_head() failed: %d\n", ret);
+	}
+
+	ehdr.h_proto = __constant_htons(ETH_P_IP);
+	memcpy(&ehdr.h_source, &smac, 6);
+	memcpy(&ehdr.h_dest, &dmac, 6);
+
+	ret = bpf_skb_store_bytes(skb, 0, &ehdr, sizeof(ehdr), 0);
+	if (ret < 0) {
+		printk("skb_store_bytes() failed: %d\n", ret);
+		return BPF_DROP;
+	}
+
+	return bpf_redirect(ifindex, 0);
+}
+
+SEC("push_ll_and_redirect_silent")
+int do_push_ll_and_redirect_silent(struct __sk_buff *skb)
+{
+	return __do_push_ll_and_redirect(skb);
+}
+
+SEC("push_ll_and_redirect")
+int do_push_ll_and_redirect(struct __sk_buff *skb)
+{
+	int ret, ifindex = DST_IFINDEX;
+
+	ret = __do_push_ll_and_redirect(skb);
+	if (ret >= 0)
+		printk("redirected to %d\n", ifindex);
+
+	return ret;
+}
+
+static inline void __fill_garbage(struct __sk_buff *skb)
+{
+	uint64_t f = 0xFFFFFFFFFFFFFFFF;
+
+	bpf_skb_store_bytes(skb, 0, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 8, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 16, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 24, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 32, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 40, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 48, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 56, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 64, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 72, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 80, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 88, &f, sizeof(f), 0);
+}
+
+SEC("fill_garbage")
+int do_fill_garbage(struct __sk_buff *skb)
+{
+	__fill_garbage(skb);
+	printk("Set initial 96 bytes of header to FF\n");
+	return BPF_OK;
+}
+
+SEC("fill_garbage_and_redirect")
+int do_fill_garbage_and_redirect(struct __sk_buff *skb)
+{
+	int ifindex = DST_IFINDEX;
+	__fill_garbage(skb);
+	printk("redirected to %d\n", ifindex);
+	return bpf_redirect(ifindex, 0);
+}
+
+/* Drop all packets */
+SEC("drop_all")
+int do_drop_all(struct __sk_buff *skb)
+{
+	printk("dropping with: %d\n", BPF_DROP);
+	return BPF_DROP;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/test_lwt_bpf.sh b/samples/bpf/test_lwt_bpf.sh
new file mode 100755
index 000000000..65a976058
--- /dev/null
+++ b/samples/bpf/test_lwt_bpf.sh
@@ -0,0 +1,400 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Uncomment to see generated bytecode
+#VERBOSE=verbose
+
+NS1=lwt_ns1
+NS2=lwt_ns2
+VETH0=tst_lwt1a
+VETH1=tst_lwt1b
+VETH2=tst_lwt2a
+VETH3=tst_lwt2b
+IPVETH0="192.168.254.1"
+IPVETH1="192.168.254.2"
+IPVETH1b="192.168.254.3"
+
+IPVETH2="192.168.111.1"
+IPVETH3="192.168.111.2"
+
+IP_LOCAL="192.168.99.1"
+
+TRACE_ROOT=/sys/kernel/debug/tracing
+
+function lookup_mac()
+{
+	set +x
+	if [ ! -z "$2" ]; then
+		MAC=$(ip netns exec $2 ip link show $1 | grep ether | awk '{print $2}')
+	else
+		MAC=$(ip link show $1 | grep ether | awk '{print $2}')
+	fi
+	MAC="${MAC//:/}"
+	echo "0x${MAC:10:2}${MAC:8:2}${MAC:6:2}${MAC:4:2}${MAC:2:2}${MAC:0:2}"
+	set -x
+}
+
+function cleanup {
+	set +ex
+	rm test_lwt_bpf.o 2> /dev/null
+	ip link del $VETH0 2> /dev/null
+	ip link del $VETH1 2> /dev/null
+	ip link del $VETH2 2> /dev/null
+	ip link del $VETH3 2> /dev/null
+	ip netns exec $NS1 killall netserver
+	ip netns delete $NS1 2> /dev/null
+	ip netns delete $NS2 2> /dev/null
+	set -ex
+}
+
+function setup_one_veth {
+	ip netns add $1
+	ip link add $2 type veth peer name $3
+	ip link set dev $2 up
+	ip addr add $4/24 dev $2
+	ip link set $3 netns $1
+	ip netns exec $1 ip link set dev $3 up
+	ip netns exec $1 ip addr add $5/24 dev $3
+
+	if [ "$6" ]; then
+		ip netns exec $1 ip addr add $6/32 dev $3
+	fi
+}
+
+function get_trace {
+	set +x
+	cat ${TRACE_ROOT}/trace | grep -v '^#'
+	set -x
+}
+
+function cleanup_routes {
+	ip route del ${IPVETH1}/32 dev $VETH0 2> /dev/null || true
+	ip route del table local local ${IP_LOCAL}/32 dev lo 2> /dev/null || true
+}
+
+function install_test {
+	cleanup_routes
+	cp /dev/null ${TRACE_ROOT}/trace
+
+	OPTS="encap bpf headroom 14 $1 obj test_lwt_bpf.o section $2 $VERBOSE"
+
+	if [ "$1" == "in" ];  then
+		ip route add table local local ${IP_LOCAL}/32 $OPTS dev lo
+	else
+		ip route add ${IPVETH1}/32 $OPTS dev $VETH0
+	fi
+}
+
+function remove_prog {
+	if [ "$1" == "in" ];  then
+		ip route del table local local ${IP_LOCAL}/32 dev lo
+	else
+		ip route del ${IPVETH1}/32 dev $VETH0
+	fi
+}
+
+function filter_trace {
+	# Add newline to allow starting EXPECT= variables on newline
+	NL=$'\n'
+	echo "${NL}$*" | sed -e 's/^.*: : //g'
+}
+
+function expect_fail {
+	set +x
+	echo "FAIL:"
+	echo "Expected: $1"
+	echo "Got: $2"
+	set -x
+	exit 1
+}
+
+function match_trace {
+	set +x
+	RET=0
+	TRACE=$1
+	EXPECT=$2
+	GOT="$(filter_trace "$TRACE")"
+
+	[ "$GOT" != "$EXPECT" ] && {
+		expect_fail "$EXPECT" "$GOT"
+		RET=1
+	}
+	set -x
+	return $RET
+}
+
+function test_start {
+	set +x
+	echo "----------------------------------------------------------------"
+	echo "Starting test: $*"
+	echo "----------------------------------------------------------------"
+	set -x
+}
+
+function failure {
+	get_trace
+	echo "FAIL: $*"
+	exit 1
+}
+
+function test_ctx_xmit {
+	test_start "test_ctx on lwt xmit"
+	install_test xmit test_ctx
+	ping -c 3 $IPVETH1 || {
+		failure "test_ctx xmit: packets are dropped"
+	}
+	match_trace "$(get_trace)" "
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 0 ifindex $DST_IFINDEX
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 0 ifindex $DST_IFINDEX
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 0 ifindex $DST_IFINDEX" || exit 1
+	remove_prog xmit
+}
+
+function test_ctx_out {
+	test_start "test_ctx on lwt out"
+	install_test out test_ctx
+	ping -c 3 $IPVETH1 || {
+		failure "test_ctx out: packets are dropped"
+	}
+	match_trace "$(get_trace)" "
+len 84 hash 0 protocol 0
+cb 1234 ingress_ifindex 0 ifindex 0
+len 84 hash 0 protocol 0
+cb 1234 ingress_ifindex 0 ifindex 0
+len 84 hash 0 protocol 0
+cb 1234 ingress_ifindex 0 ifindex 0" || exit 1
+	remove_prog out
+}
+
+function test_ctx_in {
+	test_start "test_ctx on lwt in"
+	install_test in test_ctx
+	ping -c 3 $IP_LOCAL || {
+		failure "test_ctx out: packets are dropped"
+	}
+	# We will both request & reply packets as the packets will
+	# be from $IP_LOCAL => $IP_LOCAL
+	match_trace "$(get_trace)" "
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1" || exit 1
+	remove_prog in
+}
+
+function test_data {
+	test_start "test_data on lwt $1"
+	install_test $1 test_data
+	ping -c 3 $IPVETH1 || {
+		failure "test_data ${1}: packets are dropped"
+	}
+	match_trace "$(get_trace)" "
+src: 1fea8c0 dst: 2fea8c0
+src: 1fea8c0 dst: 2fea8c0
+src: 1fea8c0 dst: 2fea8c0" || exit 1
+	remove_prog $1
+}
+
+function test_data_in {
+	test_start "test_data on lwt in"
+	install_test in test_data
+	ping -c 3 $IP_LOCAL || {
+		failure "test_data in: packets are dropped"
+	}
+	# We will both request & reply packets as the packets will
+	# be from $IP_LOCAL => $IP_LOCAL
+	match_trace "$(get_trace)" "
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0" || exit 1
+	remove_prog in
+}
+
+function test_cb {
+	test_start "test_cb on lwt $1"
+	install_test $1 test_cb
+	ping -c 3 $IPVETH1 || {
+		failure "test_cb ${1}: packets are dropped"
+	}
+	match_trace "$(get_trace)" "
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0" || exit 1
+	remove_prog $1
+}
+
+function test_cb_in {
+	test_start "test_cb on lwt in"
+	install_test in test_cb
+	ping -c 3 $IP_LOCAL || {
+		failure "test_cb in: packets are dropped"
+	}
+	# We will both request & reply packets as the packets will
+	# be from $IP_LOCAL => $IP_LOCAL
+	match_trace "$(get_trace)" "
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0" || exit 1
+	remove_prog in
+}
+
+function test_drop_all {
+	test_start "test_drop_all on lwt $1"
+	install_test $1 drop_all
+	ping -c 3 $IPVETH1 && {
+		failure "test_drop_all ${1}: Unexpected success of ping"
+	}
+	match_trace "$(get_trace)" "
+dropping with: 2
+dropping with: 2
+dropping with: 2" || exit 1
+	remove_prog $1
+}
+
+function test_drop_all_in {
+	test_start "test_drop_all on lwt in"
+	install_test in drop_all
+	ping -c 3 $IP_LOCAL && {
+		failure "test_drop_all in: Unexpected success of ping"
+	}
+	match_trace "$(get_trace)" "
+dropping with: 2
+dropping with: 2
+dropping with: 2" || exit 1
+	remove_prog in
+}
+
+function test_push_ll_and_redirect {
+	test_start "test_push_ll_and_redirect on lwt xmit"
+	install_test xmit push_ll_and_redirect
+	ping -c 3 $IPVETH1 || {
+		failure "Redirected packets appear to be dropped"
+	}
+	match_trace "$(get_trace)" "
+redirected to $DST_IFINDEX
+redirected to $DST_IFINDEX
+redirected to $DST_IFINDEX" || exit 1
+	remove_prog xmit
+}
+
+function test_no_l2_and_redirect {
+	test_start "test_no_l2_and_redirect on lwt xmit"
+	install_test xmit fill_garbage_and_redirect
+	ping -c 3 $IPVETH1 && {
+		failure "Unexpected success despite lack of L2 header"
+	}
+	match_trace "$(get_trace)" "
+redirected to $DST_IFINDEX
+redirected to $DST_IFINDEX
+redirected to $DST_IFINDEX" || exit 1
+	remove_prog xmit
+}
+
+function test_rewrite {
+	test_start "test_rewrite on lwt xmit"
+	install_test xmit test_rewrite
+	ping -c 3 $IPVETH1 || {
+		failure "Rewritten packets appear to be dropped"
+	}
+	match_trace "$(get_trace)" "
+out: rewriting from 2fea8c0 to 3fea8c0
+out: rewriting from 2fea8c0 to 3fea8c0
+out: rewriting from 2fea8c0 to 3fea8c0" || exit 1
+	remove_prog out
+}
+
+function test_fill_garbage {
+	test_start "test_fill_garbage on lwt xmit"
+	install_test xmit fill_garbage
+	ping -c 3 $IPVETH1 && {
+		failure "test_drop_all ${1}: Unexpected success of ping"
+	}
+	match_trace "$(get_trace)" "
+Set initial 96 bytes of header to FF
+Set initial 96 bytes of header to FF
+Set initial 96 bytes of header to FF" || exit 1
+	remove_prog xmit
+}
+
+function test_netperf_nop {
+	test_start "test_netperf_nop on lwt xmit"
+	install_test xmit nop
+	netperf -H $IPVETH1 -t TCP_STREAM || {
+		failure "packets appear to be dropped"
+	}
+	match_trace "$(get_trace)" ""|| exit 1
+	remove_prog xmit
+}
+
+function test_netperf_redirect {
+	test_start "test_netperf_redirect on lwt xmit"
+	install_test xmit push_ll_and_redirect_silent
+	netperf -H $IPVETH1 -t TCP_STREAM || {
+		failure "Rewritten packets appear to be dropped"
+	}
+	match_trace "$(get_trace)" ""|| exit 1
+	remove_prog xmit
+}
+
+cleanup
+setup_one_veth $NS1 $VETH0 $VETH1 $IPVETH0 $IPVETH1 $IPVETH1b
+setup_one_veth $NS2 $VETH2 $VETH3 $IPVETH2 $IPVETH3
+ip netns exec $NS1 netserver
+echo 1 > ${TRACE_ROOT}/tracing_on
+
+DST_MAC=$(lookup_mac $VETH1 $NS1)
+SRC_MAC=$(lookup_mac $VETH0)
+DST_IFINDEX=$(cat /sys/class/net/$VETH0/ifindex)
+
+CLANG_OPTS="-O2 -target bpf -I ../include/"
+CLANG_OPTS+=" -DSRC_MAC=$SRC_MAC -DDST_MAC=$DST_MAC -DDST_IFINDEX=$DST_IFINDEX"
+clang $CLANG_OPTS -c test_lwt_bpf.c -o test_lwt_bpf.o
+
+test_ctx_xmit
+test_ctx_out
+test_ctx_in
+test_data "xmit"
+test_data "out"
+test_data_in
+test_cb "xmit"
+test_cb "out"
+test_cb_in
+test_drop_all "xmit"
+test_drop_all "out"
+test_drop_all_in
+test_rewrite
+test_push_ll_and_redirect
+test_no_l2_and_redirect
+test_fill_garbage
+test_netperf_nop
+test_netperf_redirect
+
+cleanup
+echo 0 > ${TRACE_ROOT}/tracing_on
+exit 0
diff --git a/samples/bpf/test_map_in_map_kern.c b/samples/bpf/test_map_in_map_kern.c
new file mode 100644
index 000000000..b0200c8ea
--- /dev/null
+++ b/samples/bpf/test_map_in_map_kern.c
@@ -0,0 +1,176 @@
+/*
+ * Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <linux/ptrace.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/in6.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+#include "trace_common.h"
+
+#define MAX_NR_PORTS 65536
+
+/* map #0 */
+struct inner_a {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, int);
+	__uint(max_entries, MAX_NR_PORTS);
+} port_a SEC(".maps");
+
+/* map #1 */
+struct inner_h {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, int);
+	__uint(max_entries, 1);
+} port_h SEC(".maps");
+
+/* map #2 */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, int);
+	__uint(max_entries, 1);
+} reg_result_h SEC(".maps");
+
+/* map #3 */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, int);
+	__uint(max_entries, 1);
+} inline_result_h SEC(".maps");
+
+/* map #4 */ /* Test case #0 */
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
+	__uint(max_entries, MAX_NR_PORTS);
+	__uint(key_size, sizeof(u32));
+	__array(values, struct inner_a); /* use inner_a as inner map */
+} a_of_port_a SEC(".maps");
+
+/* map #5 */ /* Test case #1 */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
+	__uint(max_entries, 1);
+	__uint(key_size, sizeof(u32));
+	__array(values, struct inner_a); /* use inner_a as inner map */
+} h_of_port_a SEC(".maps");
+
+/* map #6 */ /* Test case #2 */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
+	__uint(max_entries, 1);
+	__uint(key_size, sizeof(u32));
+	__array(values, struct inner_h); /* use inner_h as inner map */
+} h_of_port_h SEC(".maps");
+
+static __always_inline int do_reg_lookup(void *inner_map, u32 port)
+{
+	int *result;
+
+	result = bpf_map_lookup_elem(inner_map, &port);
+	return result ? *result : -ENOENT;
+}
+
+static __always_inline int do_inline_array_lookup(void *inner_map, u32 port)
+{
+	int *result;
+
+	if (inner_map != &port_a)
+		return -EINVAL;
+
+	result = bpf_map_lookup_elem(&port_a, &port);
+	return result ? *result : -ENOENT;
+}
+
+static __always_inline int do_inline_hash_lookup(void *inner_map, u32 port)
+{
+	int *result;
+
+	if (inner_map != &port_h)
+		return -EINVAL;
+
+	result = bpf_map_lookup_elem(&port_h, &port);
+	return result ? *result : -ENOENT;
+}
+
+SEC("kprobe/__sys_connect")
+int trace_sys_connect(struct pt_regs *ctx)
+{
+	struct sockaddr_in6 *in6;
+	u16 test_case, port, dst6[8];
+	int addrlen, ret, inline_ret, ret_key = 0;
+	u32 port_key;
+	void *outer_map, *inner_map;
+	bool inline_hash = false;
+
+	in6 = (struct sockaddr_in6 *)PT_REGS_PARM2_CORE(ctx);
+	addrlen = (int)PT_REGS_PARM3_CORE(ctx);
+
+	if (addrlen != sizeof(*in6))
+		return 0;
+
+	ret = bpf_probe_read_user(dst6, sizeof(dst6), &in6->sin6_addr);
+	if (ret) {
+		inline_ret = ret;
+		goto done;
+	}
+
+	if (dst6[0] != 0xdead || dst6[1] != 0xbeef)
+		return 0;
+
+	test_case = dst6[7];
+
+	ret = bpf_probe_read_user(&port, sizeof(port), &in6->sin6_port);
+	if (ret) {
+		inline_ret = ret;
+		goto done;
+	}
+
+	port_key = port;
+
+	ret = -ENOENT;
+	if (test_case == 0) {
+		outer_map = &a_of_port_a;
+	} else if (test_case == 1) {
+		outer_map = &h_of_port_a;
+	} else if (test_case == 2) {
+		outer_map = &h_of_port_h;
+	} else {
+		ret = __LINE__;
+		inline_ret = ret;
+		goto done;
+	}
+
+	inner_map = bpf_map_lookup_elem(outer_map, &port_key);
+	if (!inner_map) {
+		ret = __LINE__;
+		inline_ret = ret;
+		goto done;
+	}
+
+	ret = do_reg_lookup(inner_map, port_key);
+
+	if (test_case == 0 || test_case == 1)
+		inline_ret = do_inline_array_lookup(inner_map, port_key);
+	else
+		inline_ret = do_inline_hash_lookup(inner_map, port_key);
+
+done:
+	bpf_map_update_elem(&reg_result_h, &ret_key, &ret, BPF_ANY);
+	bpf_map_update_elem(&inline_result_h, &ret_key, &inline_ret, BPF_ANY);
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/test_map_in_map_user.c b/samples/bpf/test_map_in_map_user.c
new file mode 100644
index 000000000..98656de56
--- /dev/null
+++ b/samples/bpf/test_map_in_map_user.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017 Facebook
+ */
+#include <sys/resource.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <stdint.h>
+#include <assert.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+static int map_fd[7];
+
+#define PORT_A		(map_fd[0])
+#define PORT_H		(map_fd[1])
+#define REG_RESULT_H	(map_fd[2])
+#define INLINE_RESULT_H	(map_fd[3])
+#define A_OF_PORT_A	(map_fd[4]) /* Test case #0 */
+#define H_OF_PORT_A	(map_fd[5]) /* Test case #1 */
+#define H_OF_PORT_H	(map_fd[6]) /* Test case #2 */
+
+static const char * const test_names[] = {
+	"Array of Array",
+	"Hash of Array",
+	"Hash of Hash",
+};
+
+#define NR_TESTS (sizeof(test_names) / sizeof(*test_names))
+
+static void check_map_id(int inner_map_fd, int map_in_map_fd, uint32_t key)
+{
+	struct bpf_map_info info = {};
+	uint32_t info_len = sizeof(info);
+	int ret, id;
+
+	ret = bpf_obj_get_info_by_fd(inner_map_fd, &info, &info_len);
+	assert(!ret);
+
+	ret = bpf_map_lookup_elem(map_in_map_fd, &key, &id);
+	assert(!ret);
+	assert(id == info.id);
+}
+
+static void populate_map(uint32_t port_key, int magic_result)
+{
+	int ret;
+
+	ret = bpf_map_update_elem(PORT_A, &port_key, &magic_result, BPF_ANY);
+	assert(!ret);
+
+	ret = bpf_map_update_elem(PORT_H, &port_key, &magic_result,
+				  BPF_NOEXIST);
+	assert(!ret);
+
+	ret = bpf_map_update_elem(A_OF_PORT_A, &port_key, &PORT_A, BPF_ANY);
+	assert(!ret);
+	check_map_id(PORT_A, A_OF_PORT_A, port_key);
+
+	ret = bpf_map_update_elem(H_OF_PORT_A, &port_key, &PORT_A, BPF_NOEXIST);
+	assert(!ret);
+	check_map_id(PORT_A, H_OF_PORT_A, port_key);
+
+	ret = bpf_map_update_elem(H_OF_PORT_H, &port_key, &PORT_H, BPF_NOEXIST);
+	assert(!ret);
+	check_map_id(PORT_H, H_OF_PORT_H, port_key);
+}
+
+static void test_map_in_map(void)
+{
+	struct sockaddr_in6 in6 = { .sin6_family = AF_INET6 };
+	uint32_t result_key = 0, port_key;
+	int result, inline_result;
+	int magic_result = 0xfaceb00c;
+	int ret;
+	int i;
+
+	port_key = rand() & 0x00FF;
+	populate_map(port_key, magic_result);
+
+	in6.sin6_addr.s6_addr16[0] = 0xdead;
+	in6.sin6_addr.s6_addr16[1] = 0xbeef;
+	in6.sin6_port = port_key;
+
+	for (i = 0; i < NR_TESTS; i++) {
+		printf("%s: ", test_names[i]);
+
+		in6.sin6_addr.s6_addr16[7] = i;
+		ret = connect(-1, (struct sockaddr *)&in6, sizeof(in6));
+		assert(ret == -1 && errno == EBADF);
+
+		ret = bpf_map_lookup_elem(REG_RESULT_H, &result_key, &result);
+		assert(!ret);
+
+		ret = bpf_map_lookup_elem(INLINE_RESULT_H, &result_key,
+					  &inline_result);
+		assert(!ret);
+
+		if (result != magic_result || inline_result != magic_result) {
+			printf("Error. result:%d inline_result:%d\n",
+			       result, inline_result);
+			exit(1);
+		}
+
+		bpf_map_delete_elem(REG_RESULT_H, &result_key);
+		bpf_map_delete_elem(INLINE_RESULT_H, &result_key);
+
+		printf("Pass\n");
+	}
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "trace_sys_connect");
+	if (!prog) {
+		printf("finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "port_a");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "port_h");
+	map_fd[2] = bpf_object__find_map_fd_by_name(obj, "reg_result_h");
+	map_fd[3] = bpf_object__find_map_fd_by_name(obj, "inline_result_h");
+	map_fd[4] = bpf_object__find_map_fd_by_name(obj, "a_of_port_a");
+	map_fd[5] = bpf_object__find_map_fd_by_name(obj, "h_of_port_a");
+	map_fd[6] = bpf_object__find_map_fd_by_name(obj, "h_of_port_h");
+	if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0 ||
+	    map_fd[3] < 0 || map_fd[4] < 0 || map_fd[5] < 0 || map_fd[6] < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	test_map_in_map();
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/test_overhead_kprobe_kern.c b/samples/bpf/test_overhead_kprobe_kern.c
new file mode 100644
index 000000000..f6d593e47
--- /dev/null
+++ b/samples/bpf/test_overhead_kprobe_kern.c
@@ -0,0 +1,48 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/version.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#define _(P)                                                                   \
+	({                                                                     \
+		typeof(P) val = 0;                                             \
+		bpf_probe_read_kernel(&val, sizeof(val), &(P));                \
+		val;                                                           \
+	})
+
+SEC("kprobe/__set_task_comm")
+int prog(struct pt_regs *ctx)
+{
+	struct signal_struct *signal;
+	struct task_struct *tsk;
+	char oldcomm[16] = {};
+	char newcomm[16] = {};
+	u16 oom_score_adj;
+	u32 pid;
+
+	tsk = (void *)PT_REGS_PARM1(ctx);
+
+	pid = _(tsk->pid);
+	bpf_probe_read_kernel(oldcomm, sizeof(oldcomm), &tsk->comm);
+	bpf_probe_read_kernel(newcomm, sizeof(newcomm),
+			      (void *)PT_REGS_PARM2(ctx));
+	signal = _(tsk->signal);
+	oom_score_adj = _(signal->oom_score_adj);
+	return 0;
+}
+
+SEC("kprobe/urandom_read")
+int prog2(struct pt_regs *ctx)
+{
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/test_overhead_raw_tp_kern.c b/samples/bpf/test_overhead_raw_tp_kern.c
new file mode 100644
index 000000000..8763181a3
--- /dev/null
+++ b/samples/bpf/test_overhead_raw_tp_kern.c
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2018 Facebook */
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+SEC("raw_tracepoint/task_rename")
+int prog(struct bpf_raw_tracepoint_args *ctx)
+{
+	return 0;
+}
+
+SEC("raw_tracepoint/urandom_read")
+int prog2(struct bpf_raw_tracepoint_args *ctx)
+{
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/test_overhead_tp_kern.c b/samples/bpf/test_overhead_tp_kern.c
new file mode 100644
index 000000000..eaa32693f
--- /dev/null
+++ b/samples/bpf/test_overhead_tp_kern.c
@@ -0,0 +1,36 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+/* from /sys/kernel/debug/tracing/events/task/task_rename/format */
+struct task_rename {
+	__u64 pad;
+	__u32 pid;
+	char oldcomm[16];
+	char newcomm[16];
+	__u16 oom_score_adj;
+};
+SEC("tracepoint/task/task_rename")
+int prog(struct task_rename *ctx)
+{
+	return 0;
+}
+
+/* from /sys/kernel/debug/tracing/events/random/urandom_read/format */
+struct urandom_read {
+	__u64 pad;
+	int got_bits;
+	int pool_left;
+	int input_left;
+};
+SEC("tracepoint/random/urandom_read")
+int prog2(struct urandom_read *ctx)
+{
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/test_overhead_user.c b/samples/bpf/test_overhead_user.c
new file mode 100644
index 000000000..94f74112a
--- /dev/null
+++ b/samples/bpf/test_overhead_user.c
@@ -0,0 +1,182 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#define _GNU_SOURCE
+#include <sched.h>
+#include <errno.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <asm/unistd.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <assert.h>
+#include <sys/wait.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <linux/bpf.h>
+#include <string.h>
+#include <time.h>
+#include <sys/resource.h>
+#include <bpf/bpf.h>
+#include "bpf_load.h"
+
+#define MAX_CNT 1000000
+
+static __u64 time_get_ns(void)
+{
+	struct timespec ts;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
+}
+
+static void test_task_rename(int cpu)
+{
+	__u64 start_time;
+	char buf[] = "test\n";
+	int i, fd;
+
+	fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
+	if (fd < 0) {
+		printf("couldn't open /proc\n");
+		exit(1);
+	}
+	start_time = time_get_ns();
+	for (i = 0; i < MAX_CNT; i++) {
+		if (write(fd, buf, sizeof(buf)) < 0) {
+			printf("task rename failed: %s\n", strerror(errno));
+			close(fd);
+			return;
+		}
+	}
+	printf("task_rename:%d: %lld events per sec\n",
+	       cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
+	close(fd);
+}
+
+static void test_urandom_read(int cpu)
+{
+	__u64 start_time;
+	char buf[4];
+	int i, fd;
+
+	fd = open("/dev/urandom", O_RDONLY);
+	if (fd < 0) {
+		printf("couldn't open /dev/urandom\n");
+		exit(1);
+	}
+	start_time = time_get_ns();
+	for (i = 0; i < MAX_CNT; i++) {
+		if (read(fd, buf, sizeof(buf)) < 0) {
+			printf("failed to read from /dev/urandom: %s\n", strerror(errno));
+			close(fd);
+			return;
+		}
+	}
+	printf("urandom_read:%d: %lld events per sec\n",
+	       cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
+	close(fd);
+}
+
+static void loop(int cpu, int flags)
+{
+	cpu_set_t cpuset;
+
+	CPU_ZERO(&cpuset);
+	CPU_SET(cpu, &cpuset);
+	sched_setaffinity(0, sizeof(cpuset), &cpuset);
+
+	if (flags & 1)
+		test_task_rename(cpu);
+	if (flags & 2)
+		test_urandom_read(cpu);
+}
+
+static void run_perf_test(int tasks, int flags)
+{
+	pid_t pid[tasks];
+	int i;
+
+	for (i = 0; i < tasks; i++) {
+		pid[i] = fork();
+		if (pid[i] == 0) {
+			loop(i, flags);
+			exit(0);
+		} else if (pid[i] == -1) {
+			printf("couldn't spawn #%d process\n", i);
+			exit(1);
+		}
+	}
+	for (i = 0; i < tasks; i++) {
+		int status;
+
+		assert(waitpid(pid[i], &status, 0) == pid[i]);
+		assert(status == 0);
+	}
+}
+
+static void unload_progs(void)
+{
+	close(prog_fd[0]);
+	close(prog_fd[1]);
+	close(event_fd[0]);
+	close(event_fd[1]);
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	char filename[256];
+	int num_cpu = 8;
+	int test_flags = ~0;
+
+	setrlimit(RLIMIT_MEMLOCK, &r);
+
+	if (argc > 1)
+		test_flags = atoi(argv[1]) ? : test_flags;
+	if (argc > 2)
+		num_cpu = atoi(argv[2]) ? : num_cpu;
+
+	if (test_flags & 0x3) {
+		printf("BASE\n");
+		run_perf_test(num_cpu, test_flags);
+	}
+
+	if (test_flags & 0xC) {
+		snprintf(filename, sizeof(filename),
+			 "%s_kprobe_kern.o", argv[0]);
+		if (load_bpf_file(filename)) {
+			printf("%s", bpf_log_buf);
+			return 1;
+		}
+		printf("w/KPROBE\n");
+		run_perf_test(num_cpu, test_flags >> 2);
+		unload_progs();
+	}
+
+	if (test_flags & 0x30) {
+		snprintf(filename, sizeof(filename),
+			 "%s_tp_kern.o", argv[0]);
+		if (load_bpf_file(filename)) {
+			printf("%s", bpf_log_buf);
+			return 1;
+		}
+		printf("w/TRACEPOINT\n");
+		run_perf_test(num_cpu, test_flags >> 4);
+		unload_progs();
+	}
+
+	if (test_flags & 0xC0) {
+		snprintf(filename, sizeof(filename),
+			 "%s_raw_tp_kern.o", argv[0]);
+		if (load_bpf_file(filename)) {
+			printf("%s", bpf_log_buf);
+			return 1;
+		}
+		printf("w/RAW_TRACEPOINT\n");
+		run_perf_test(num_cpu, test_flags >> 6);
+		unload_progs();
+	}
+
+	return 0;
+}
diff --git a/samples/bpf/test_override_return.sh b/samples/bpf/test_override_return.sh
new file mode 100755
index 000000000..35db26f73
--- /dev/null
+++ b/samples/bpf/test_override_return.sh
@@ -0,0 +1,16 @@
+#!/bin/bash
+
+rm -r tmpmnt
+rm -f testfile.img
+dd if=/dev/zero of=testfile.img bs=1M seek=1000 count=1
+DEVICE=$(losetup --show -f testfile.img)
+mkfs.btrfs -f $DEVICE
+mkdir tmpmnt
+./tracex7 $DEVICE
+if [ $? -eq 0 ]
+then
+	echo "SUCCESS!"
+else
+	echo "FAILED!"
+fi
+losetup -d $DEVICE
diff --git a/samples/bpf/test_probe_write_user_kern.c b/samples/bpf/test_probe_write_user_kern.c
new file mode 100644
index 000000000..220a96438
--- /dev/null
+++ b/samples/bpf/test_probe_write_user_kern.c
@@ -0,0 +1,56 @@
+/* Copyright (c) 2016 Sargun Dhillon <sargun@sargun.me>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <uapi/linux/bpf.h>
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+#include "trace_common.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, struct sockaddr_in);
+	__type(value, struct sockaddr_in);
+	__uint(max_entries, 256);
+} dnat_map SEC(".maps");
+
+/* kprobe is NOT a stable ABI
+ * kernel functions can be removed, renamed or completely change semantics.
+ * Number of arguments and their positions can change, etc.
+ * In such case this bpf+kprobe example will no longer be meaningful
+ *
+ * This example sits on a syscall, and the syscall ABI is relatively stable
+ * of course, across platforms, and over time, the ABI may change.
+ */
+SEC("kprobe/" SYSCALL(sys_connect))
+int bpf_prog1(struct pt_regs *ctx)
+{
+	struct pt_regs *real_regs = (struct pt_regs *)PT_REGS_PARM1_CORE(ctx);
+	void *sockaddr_arg = (void *)PT_REGS_PARM2_CORE(real_regs);
+	int sockaddr_len = (int)PT_REGS_PARM3_CORE(real_regs);
+	struct sockaddr_in new_addr, orig_addr = {};
+	struct sockaddr_in *mapped_addr;
+
+	if (sockaddr_len > sizeof(orig_addr))
+		return 0;
+
+	if (bpf_probe_read_user(&orig_addr, sizeof(orig_addr), sockaddr_arg) != 0)
+		return 0;
+
+	mapped_addr = bpf_map_lookup_elem(&dnat_map, &orig_addr);
+	if (mapped_addr != NULL) {
+		memcpy(&new_addr, mapped_addr, sizeof(new_addr));
+		bpf_probe_write_user(sockaddr_arg, &new_addr,
+				     sizeof(new_addr));
+	}
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/test_probe_write_user_user.c b/samples/bpf/test_probe_write_user_user.c
new file mode 100644
index 000000000..00ccfb834
--- /dev/null
+++ b/samples/bpf/test_probe_write_user_user.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <assert.h>
+#include <unistd.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+int main(int ac, char **argv)
+{
+	struct sockaddr_in *serv_addr_in, *mapped_addr_in, *tmp_addr_in;
+	struct sockaddr serv_addr, mapped_addr, tmp_addr;
+	int serverfd, serverconnfd, clientfd, map_fd;
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	socklen_t sockaddr_len;
+	char filename[256];
+	char *ip;
+
+	serv_addr_in = (struct sockaddr_in *)&serv_addr;
+	mapped_addr_in = (struct sockaddr_in *)&mapped_addr;
+	tmp_addr_in = (struct sockaddr_in *)&tmp_addr;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (libbpf_get_error(prog)) {
+		fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "dnat_map");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	assert((serverfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
+	assert((clientfd = socket(AF_INET, SOCK_STREAM, 0)) > 0);
+
+	/* Bind server to ephemeral port on lo */
+	memset(&serv_addr, 0, sizeof(serv_addr));
+	serv_addr_in->sin_family = AF_INET;
+	serv_addr_in->sin_port = 0;
+	serv_addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+	assert(bind(serverfd, &serv_addr, sizeof(serv_addr)) == 0);
+
+	sockaddr_len = sizeof(serv_addr);
+	assert(getsockname(serverfd, &serv_addr, &sockaddr_len) == 0);
+	ip = inet_ntoa(serv_addr_in->sin_addr);
+	printf("Server bound to: %s:%d\n", ip, ntohs(serv_addr_in->sin_port));
+
+	memset(&mapped_addr, 0, sizeof(mapped_addr));
+	mapped_addr_in->sin_family = AF_INET;
+	mapped_addr_in->sin_port = htons(5555);
+	mapped_addr_in->sin_addr.s_addr = inet_addr("255.255.255.255");
+
+	assert(!bpf_map_update_elem(map_fd, &mapped_addr, &serv_addr, BPF_ANY));
+
+	assert(listen(serverfd, 5) == 0);
+
+	ip = inet_ntoa(mapped_addr_in->sin_addr);
+	printf("Client connecting to: %s:%d\n",
+	       ip, ntohs(mapped_addr_in->sin_port));
+	assert(connect(clientfd, &mapped_addr, sizeof(mapped_addr)) == 0);
+
+	sockaddr_len = sizeof(tmp_addr);
+	ip = inet_ntoa(tmp_addr_in->sin_addr);
+	assert((serverconnfd = accept(serverfd, &tmp_addr, &sockaddr_len)) > 0);
+	printf("Server received connection from: %s:%d\n",
+	       ip, ntohs(tmp_addr_in->sin_port));
+
+	sockaddr_len = sizeof(tmp_addr);
+	assert(getpeername(clientfd, &tmp_addr, &sockaddr_len) == 0);
+	ip = inet_ntoa(tmp_addr_in->sin_addr);
+	printf("Client's peer address: %s:%d\n",
+	       ip, ntohs(tmp_addr_in->sin_port));
+
+	/* Is the server's getsockname = the socket getpeername */
+	assert(memcmp(&serv_addr, &tmp_addr, sizeof(struct sockaddr_in)) == 0);
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/trace_common.h b/samples/bpf/trace_common.h
new file mode 100644
index 000000000..8cb5400ae
--- /dev/null
+++ b/samples/bpf/trace_common.h
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef __TRACE_COMMON_H
+#define __TRACE_COMMON_H
+
+#ifdef __x86_64__
+#define SYSCALL(SYS) "__x64_" __stringify(SYS)
+#elif defined(__s390x__)
+#define SYSCALL(SYS) "__s390x_" __stringify(SYS)
+#else
+#define SYSCALL(SYS)  __stringify(SYS)
+#endif
+
+#endif
diff --git a/samples/bpf/trace_event_kern.c b/samples/bpf/trace_event_kern.c
new file mode 100644
index 000000000..7d3c66fb3
--- /dev/null
+++ b/samples/bpf/trace_event_kern.c
@@ -0,0 +1,80 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/ptrace.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/bpf_perf_event.h>
+#include <uapi/linux/perf_event.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct key_t {
+	char comm[TASK_COMM_LEN];
+	u32 kernstack;
+	u32 userstack;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, struct key_t);
+	__type(value, u64);
+	__uint(max_entries, 10000);
+} counts SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
+	__uint(max_entries, 10000);
+} stackmap SEC(".maps");
+
+#define KERN_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
+#define USER_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP | BPF_F_USER_STACK)
+
+SEC("perf_event")
+int bpf_prog1(struct bpf_perf_event_data *ctx)
+{
+	char time_fmt1[] = "Time Enabled: %llu, Time Running: %llu";
+	char time_fmt2[] = "Get Time Failed, ErrCode: %d";
+	char addr_fmt[] = "Address recorded on event: %llx";
+	char fmt[] = "CPU-%d period %lld ip %llx";
+	u32 cpu = bpf_get_smp_processor_id();
+	struct bpf_perf_event_value value_buf;
+	struct key_t key;
+	u64 *val, one = 1;
+	int ret;
+
+	if (ctx->sample_period < 10000)
+		/* ignore warmup */
+		return 0;
+	bpf_get_current_comm(&key.comm, sizeof(key.comm));
+	key.kernstack = bpf_get_stackid(ctx, &stackmap, KERN_STACKID_FLAGS);
+	key.userstack = bpf_get_stackid(ctx, &stackmap, USER_STACKID_FLAGS);
+	if ((int)key.kernstack < 0 && (int)key.userstack < 0) {
+		bpf_trace_printk(fmt, sizeof(fmt), cpu, ctx->sample_period,
+				 PT_REGS_IP(&ctx->regs));
+		return 0;
+	}
+
+	ret = bpf_perf_prog_read_value(ctx, (void *)&value_buf, sizeof(struct bpf_perf_event_value));
+	if (!ret)
+	  bpf_trace_printk(time_fmt1, sizeof(time_fmt1), value_buf.enabled, value_buf.running);
+	else
+	  bpf_trace_printk(time_fmt2, sizeof(time_fmt2), ret);
+
+	if (ctx->addr != 0)
+	  bpf_trace_printk(addr_fmt, sizeof(addr_fmt), ctx->addr);
+
+	val = bpf_map_lookup_elem(&counts, &key);
+	if (val)
+		(*val)++;
+	else
+		bpf_map_update_elem(&counts, &key, &one, BPF_NOEXIST);
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/trace_event_user.c b/samples/bpf/trace_event_user.c
new file mode 100644
index 000000000..ac1ba3681
--- /dev/null
+++ b/samples/bpf/trace_event_user.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <linux/perf_event.h>
+#include <linux/bpf.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/resource.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "perf-sys.h"
+#include "trace_helpers.h"
+
+#define SAMPLE_FREQ 50
+
+static int pid;
+/* counts, stackmap */
+static int map_fd[2];
+struct bpf_program *prog;
+static bool sys_read_seen, sys_write_seen;
+
+static void print_ksym(__u64 addr)
+{
+	struct ksym *sym;
+
+	if (!addr)
+		return;
+	sym = ksym_search(addr);
+	if (!sym) {
+		printf("ksym not found. Is kallsyms loaded?\n");
+		return;
+	}
+
+	printf("%s;", sym->name);
+	if (!strstr(sym->name, "sys_read"))
+		sys_read_seen = true;
+	else if (!strstr(sym->name, "sys_write"))
+		sys_write_seen = true;
+}
+
+static void print_addr(__u64 addr)
+{
+	if (!addr)
+		return;
+	printf("%llx;", addr);
+}
+
+#define TASK_COMM_LEN 16
+
+struct key_t {
+	char comm[TASK_COMM_LEN];
+	__u32 kernstack;
+	__u32 userstack;
+};
+
+static void print_stack(struct key_t *key, __u64 count)
+{
+	__u64 ip[PERF_MAX_STACK_DEPTH] = {};
+	static bool warned;
+	int i;
+
+	printf("%3lld %s;", count, key->comm);
+	if (bpf_map_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {
+		printf("---;");
+	} else {
+		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
+			print_ksym(ip[i]);
+	}
+	printf("-;");
+	if (bpf_map_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {
+		printf("---;");
+	} else {
+		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
+			print_addr(ip[i]);
+	}
+	if (count < 6)
+		printf("\r");
+	else
+		printf("\n");
+
+	if (key->kernstack == -EEXIST && !warned) {
+		printf("stackmap collisions seen. Consider increasing size\n");
+		warned = true;
+	} else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {
+		printf("err stackid %d %d\n", key->kernstack, key->userstack);
+	}
+}
+
+static void err_exit(int err)
+{
+	kill(pid, SIGKILL);
+	exit(err);
+}
+
+static void print_stacks(void)
+{
+	struct key_t key = {}, next_key;
+	__u64 value;
+	__u32 stackid = 0, next_id;
+	int error = 1, fd = map_fd[0], stack_map = map_fd[1];
+
+	sys_read_seen = sys_write_seen = false;
+	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
+		bpf_map_lookup_elem(fd, &next_key, &value);
+		print_stack(&next_key, value);
+		bpf_map_delete_elem(fd, &next_key);
+		key = next_key;
+	}
+	printf("\n");
+	if (!sys_read_seen || !sys_write_seen) {
+		printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");
+		err_exit(error);
+	}
+
+	/* clear stack map */
+	while (bpf_map_get_next_key(stack_map, &stackid, &next_id) == 0) {
+		bpf_map_delete_elem(stack_map, &next_id);
+		stackid = next_id;
+	}
+}
+
+static inline int generate_load(void)
+{
+	if (system("dd if=/dev/zero of=/dev/null count=5000k status=none") < 0) {
+		printf("failed to generate some load with dd: %s\n", strerror(errno));
+		return -1;
+	}
+
+	return 0;
+}
+
+static void test_perf_event_all_cpu(struct perf_event_attr *attr)
+{
+	int nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+	struct bpf_link **links = calloc(nr_cpus, sizeof(struct bpf_link *));
+	int i, pmu_fd, error = 1;
+
+	if (!links) {
+		printf("malloc of links failed\n");
+		goto err;
+	}
+
+	/* system wide perf event, no need to inherit */
+	attr->inherit = 0;
+
+	/* open perf_event on all cpus */
+	for (i = 0; i < nr_cpus; i++) {
+		pmu_fd = sys_perf_event_open(attr, -1, i, -1, 0);
+		if (pmu_fd < 0) {
+			printf("sys_perf_event_open failed\n");
+			goto all_cpu_err;
+		}
+		links[i] = bpf_program__attach_perf_event(prog, pmu_fd);
+		if (libbpf_get_error(links[i])) {
+			printf("bpf_program__attach_perf_event failed\n");
+			links[i] = NULL;
+			close(pmu_fd);
+			goto all_cpu_err;
+		}
+	}
+
+	if (generate_load() < 0)
+		goto all_cpu_err;
+
+	print_stacks();
+	error = 0;
+all_cpu_err:
+	for (i--; i >= 0; i--)
+		bpf_link__destroy(links[i]);
+err:
+	free(links);
+	if (error)
+		err_exit(error);
+}
+
+static void test_perf_event_task(struct perf_event_attr *attr)
+{
+	struct bpf_link *link = NULL;
+	int pmu_fd, error = 1;
+
+	/* per task perf event, enable inherit so the "dd ..." command can be traced properly.
+	 * Enabling inherit will cause bpf_perf_prog_read_time helper failure.
+	 */
+	attr->inherit = 1;
+
+	/* open task bound event */
+	pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0);
+	if (pmu_fd < 0) {
+		printf("sys_perf_event_open failed\n");
+		goto err;
+	}
+	link = bpf_program__attach_perf_event(prog, pmu_fd);
+	if (libbpf_get_error(link)) {
+		printf("bpf_program__attach_perf_event failed\n");
+		link = NULL;
+		close(pmu_fd);
+		goto err;
+	}
+
+	if (generate_load() < 0)
+		goto err;
+
+	print_stacks();
+	error = 0;
+err:
+	bpf_link__destroy(link);
+	if (error)
+		err_exit(error);
+}
+
+static void test_bpf_perf_event(void)
+{
+	struct perf_event_attr attr_type_hw = {
+		.sample_freq = SAMPLE_FREQ,
+		.freq = 1,
+		.type = PERF_TYPE_HARDWARE,
+		.config = PERF_COUNT_HW_CPU_CYCLES,
+	};
+	struct perf_event_attr attr_type_sw = {
+		.sample_freq = SAMPLE_FREQ,
+		.freq = 1,
+		.type = PERF_TYPE_SOFTWARE,
+		.config = PERF_COUNT_SW_CPU_CLOCK,
+	};
+	struct perf_event_attr attr_hw_cache_l1d = {
+		.sample_freq = SAMPLE_FREQ,
+		.freq = 1,
+		.type = PERF_TYPE_HW_CACHE,
+		.config =
+			PERF_COUNT_HW_CACHE_L1D |
+			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
+			(PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
+	};
+	struct perf_event_attr attr_hw_cache_branch_miss = {
+		.sample_freq = SAMPLE_FREQ,
+		.freq = 1,
+		.type = PERF_TYPE_HW_CACHE,
+		.config =
+			PERF_COUNT_HW_CACHE_BPU |
+			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
+			(PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
+	};
+	struct perf_event_attr attr_type_raw = {
+		.sample_freq = SAMPLE_FREQ,
+		.freq = 1,
+		.type = PERF_TYPE_RAW,
+		/* Intel Instruction Retired */
+		.config = 0xc0,
+	};
+	struct perf_event_attr attr_type_raw_lock_load = {
+		.sample_freq = SAMPLE_FREQ,
+		.freq = 1,
+		.type = PERF_TYPE_RAW,
+		/* Intel MEM_UOPS_RETIRED.LOCK_LOADS */
+		.config = 0x21d0,
+		/* Request to record lock address from PEBS */
+		.sample_type = PERF_SAMPLE_ADDR,
+		/* Record address value requires precise event */
+		.precise_ip = 2,
+	};
+
+	printf("Test HW_CPU_CYCLES\n");
+	test_perf_event_all_cpu(&attr_type_hw);
+	test_perf_event_task(&attr_type_hw);
+
+	printf("Test SW_CPU_CLOCK\n");
+	test_perf_event_all_cpu(&attr_type_sw);
+	test_perf_event_task(&attr_type_sw);
+
+	printf("Test HW_CACHE_L1D\n");
+	test_perf_event_all_cpu(&attr_hw_cache_l1d);
+	test_perf_event_task(&attr_hw_cache_l1d);
+
+	printf("Test HW_CACHE_BPU\n");
+	test_perf_event_all_cpu(&attr_hw_cache_branch_miss);
+	test_perf_event_task(&attr_hw_cache_branch_miss);
+
+	printf("Test Instruction Retired\n");
+	test_perf_event_all_cpu(&attr_type_raw);
+	test_perf_event_task(&attr_type_raw);
+
+	printf("Test Lock Load\n");
+	test_perf_event_all_cpu(&attr_type_raw_lock_load);
+	test_perf_event_task(&attr_type_raw_lock_load);
+
+	printf("*** PASS ***\n");
+}
+
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_object *obj = NULL;
+	char filename[256];
+	int error = 1;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	setrlimit(RLIMIT_MEMLOCK, &r);
+
+	signal(SIGINT, err_exit);
+	signal(SIGTERM, err_exit);
+
+	if (load_kallsyms()) {
+		printf("failed to process /proc/kallsyms\n");
+		goto cleanup;
+	}
+
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		printf("opening BPF object file failed\n");
+		obj = NULL;
+		goto cleanup;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (!prog) {
+		printf("finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		printf("loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counts");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "stackmap");
+	if (map_fd[0] < 0 || map_fd[1] < 0) {
+		printf("finding a counts/stackmap map in obj file failed\n");
+		goto cleanup;
+	}
+
+	pid = fork();
+	if (pid == 0) {
+		read_trace_pipe();
+		return 0;
+	} else if (pid == -1) {
+		printf("couldn't spawn process\n");
+		goto cleanup;
+	}
+
+	test_bpf_perf_event();
+	error = 0;
+
+cleanup:
+	bpf_object__close(obj);
+	err_exit(error);
+}
diff --git a/samples/bpf/trace_output_kern.c b/samples/bpf/trace_output_kern.c
new file mode 100644
index 000000000..b64815af0
--- /dev/null
+++ b/samples/bpf/trace_output_kern.c
@@ -0,0 +1,31 @@
+#include <linux/ptrace.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "trace_common.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(u32));
+	__uint(max_entries, 2);
+} my_map SEC(".maps");
+
+SEC("kprobe/" SYSCALL(sys_write))
+int bpf_prog1(struct pt_regs *ctx)
+{
+	struct S {
+		u64 pid;
+		u64 cookie;
+	} data;
+
+	data.pid = bpf_get_current_pid_tgid();
+	data.cookie = 0x12345678;
+
+	bpf_perf_event_output(ctx, &my_map, 0, &data, sizeof(data));
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c
new file mode 100644
index 000000000..364b98764
--- /dev/null
+++ b/samples/bpf/trace_output_user.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <stdio.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <time.h>
+#include <signal.h>
+#include <bpf/libbpf.h>
+
+static __u64 time_get_ns(void)
+{
+	struct timespec ts;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
+}
+
+static __u64 start_time;
+static __u64 cnt;
+
+#define MAX_CNT 100000ll
+
+static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
+{
+	struct {
+		__u64 pid;
+		__u64 cookie;
+	} *e = data;
+
+	if (e->cookie != 0x12345678) {
+		printf("BUG pid %llx cookie %llx sized %d\n",
+		       e->pid, e->cookie, size);
+		return;
+	}
+
+	cnt++;
+
+	if (cnt == MAX_CNT) {
+		printf("recv %lld events per sec\n",
+		       MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
+		return;
+	}
+}
+
+int main(int argc, char **argv)
+{
+	struct perf_buffer_opts pb_opts = {};
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct perf_buffer *pb;
+	struct bpf_object *obj;
+	int map_fd, ret = 0;
+	char filename[256];
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (libbpf_get_error(prog)) {
+		fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	pb_opts.sample_cb = print_bpf_output;
+	pb = perf_buffer__new(map_fd, 8, &pb_opts);
+	ret = libbpf_get_error(pb);
+	if (ret) {
+		printf("failed to setup perf_buffer: %d\n", ret);
+		return 1;
+	}
+
+	f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
+	(void) f;
+
+	start_time = time_get_ns();
+	while ((ret = perf_buffer__poll(pb, 1000)) >= 0 && cnt < MAX_CNT) {
+	}
+	kill(0, SIGINT);
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return ret;
+}
diff --git a/samples/bpf/tracex1_kern.c b/samples/bpf/tracex1_kern.c
new file mode 100644
index 000000000..ef30d2b35
--- /dev/null
+++ b/samples/bpf/tracex1_kern.c
@@ -0,0 +1,54 @@
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <uapi/linux/bpf.h>
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#define _(P)                                                                   \
+	({                                                                     \
+		typeof(P) val = 0;                                             \
+		bpf_probe_read_kernel(&val, sizeof(val), &(P));                \
+		val;                                                           \
+	})
+
+/* kprobe is NOT a stable ABI
+ * kernel functions can be removed, renamed or completely change semantics.
+ * Number of arguments and their positions can change, etc.
+ * In such case this bpf+kprobe example will no longer be meaningful
+ */
+SEC("kprobe/__netif_receive_skb_core")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	/* attaches to kprobe __netif_receive_skb_core,
+	 * looks for packets on loobpack device and prints them
+	 */
+	char devname[IFNAMSIZ];
+	struct net_device *dev;
+	struct sk_buff *skb;
+	int len;
+
+	/* non-portable! works for the given kernel only */
+	bpf_probe_read_kernel(&skb, sizeof(skb), (void *)PT_REGS_PARM1(ctx));
+	dev = _(skb->dev);
+	len = _(skb->len);
+
+	bpf_probe_read_kernel(devname, sizeof(devname), dev->name);
+
+	if (devname[0] == 'l' && devname[1] == 'o') {
+		char fmt[] = "skb %p len %d\n";
+		/* using bpf_trace_printk() for DEBUG ONLY */
+		bpf_trace_printk(fmt, sizeof(fmt), skb, len);
+	}
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex1_user.c b/samples/bpf/tracex1_user.c
new file mode 100644
index 000000000..9d4adb7fd
--- /dev/null
+++ b/samples/bpf/tracex1_user.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <unistd.h>
+#include <bpf/libbpf.h>
+#include "trace_helpers.h"
+
+int main(int ac, char **argv)
+{
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (!prog) {
+		fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	f = popen("taskset 1 ping -c5 localhost", "r");
+	(void) f;
+
+	read_trace_pipe();
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/tracex2_kern.c b/samples/bpf/tracex2_kern.c
new file mode 100644
index 000000000..5bc696bac
--- /dev/null
+++ b/samples/bpf/tracex2_kern.c
@@ -0,0 +1,102 @@
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include "trace_common.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, long);
+	__type(value, long);
+	__uint(max_entries, 1024);
+} my_map SEC(".maps");
+
+/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
+ * example will no longer be meaningful
+ */
+SEC("kprobe/kfree_skb")
+int bpf_prog2(struct pt_regs *ctx)
+{
+	long loc = 0;
+	long init_val = 1;
+	long *value;
+
+	/* read ip of kfree_skb caller.
+	 * non-portable version of __builtin_return_address(0)
+	 */
+	BPF_KPROBE_READ_RET_IP(loc, ctx);
+
+	value = bpf_map_lookup_elem(&my_map, &loc);
+	if (value)
+		*value += 1;
+	else
+		bpf_map_update_elem(&my_map, &loc, &init_val, BPF_ANY);
+	return 0;
+}
+
+static unsigned int log2(unsigned int v)
+{
+	unsigned int r;
+	unsigned int shift;
+
+	r = (v > 0xFFFF) << 4; v >>= r;
+	shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
+	shift = (v > 0xF) << 2; v >>= shift; r |= shift;
+	shift = (v > 0x3) << 1; v >>= shift; r |= shift;
+	r |= (v >> 1);
+	return r;
+}
+
+static unsigned int log2l(unsigned long v)
+{
+	unsigned int hi = v >> 32;
+	if (hi)
+		return log2(hi) + 32;
+	else
+		return log2(v);
+}
+
+struct hist_key {
+	char comm[16];
+	u64 pid_tgid;
+	u64 uid_gid;
+	u64 index;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+	__uint(key_size, sizeof(struct hist_key));
+	__uint(value_size, sizeof(long));
+	__uint(max_entries, 1024);
+} my_hist_map SEC(".maps");
+
+SEC("kprobe/" SYSCALL(sys_write))
+int bpf_prog3(struct pt_regs *ctx)
+{
+	long write_size = PT_REGS_PARM3(ctx);
+	long init_val = 1;
+	long *value;
+	struct hist_key key;
+
+	key.index = log2l(write_size);
+	key.pid_tgid = bpf_get_current_pid_tgid();
+	key.uid_gid = bpf_get_current_uid_gid();
+	bpf_get_current_comm(&key.comm, sizeof(key.comm));
+
+	value = bpf_map_lookup_elem(&my_hist_map, &key);
+	if (value)
+		__sync_fetch_and_add(value, 1);
+	else
+		bpf_map_update_elem(&my_hist_map, &key, &init_val, BPF_ANY);
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex2_user.c b/samples/bpf/tracex2_user.c
new file mode 100644
index 000000000..3d6eab711
--- /dev/null
+++ b/samples/bpf/tracex2_user.c
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <sys/resource.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "bpf_util.h"
+
+#define MAX_INDEX	64
+#define MAX_STARS	38
+
+/* my_map, my_hist_map */
+static int map_fd[2];
+
+static void stars(char *str, long val, long max, int width)
+{
+	int i;
+
+	for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
+		str[i] = '*';
+	if (val > max)
+		str[i - 1] = '+';
+	str[i] = '\0';
+}
+
+struct task {
+	char comm[16];
+	__u64 pid_tgid;
+	__u64 uid_gid;
+};
+
+struct hist_key {
+	struct task t;
+	__u32 index;
+};
+
+#define SIZE sizeof(struct task)
+
+static void print_hist_for_pid(int fd, void *task)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	struct hist_key key = {}, next_key;
+	long values[nr_cpus];
+	char starstr[MAX_STARS];
+	long value;
+	long data[MAX_INDEX] = {};
+	int max_ind = -1;
+	long max_value = 0;
+	int i, ind;
+
+	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
+		if (memcmp(&next_key, task, SIZE)) {
+			key = next_key;
+			continue;
+		}
+		bpf_map_lookup_elem(fd, &next_key, values);
+		value = 0;
+		for (i = 0; i < nr_cpus; i++)
+			value += values[i];
+		ind = next_key.index;
+		data[ind] = value;
+		if (value && ind > max_ind)
+			max_ind = ind;
+		if (value > max_value)
+			max_value = value;
+		key = next_key;
+	}
+
+	printf("           syscall write() stats\n");
+	printf("     byte_size       : count     distribution\n");
+	for (i = 1; i <= max_ind + 1; i++) {
+		stars(starstr, data[i - 1], max_value, MAX_STARS);
+		printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
+		       (1l << i) >> 1, (1l << i) - 1, data[i - 1],
+		       MAX_STARS, starstr);
+	}
+}
+
+static void print_hist(int fd)
+{
+	struct hist_key key = {}, next_key;
+	static struct task tasks[1024];
+	int task_cnt = 0;
+	int i;
+
+	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
+		int found = 0;
+
+		for (i = 0; i < task_cnt; i++)
+			if (memcmp(&tasks[i], &next_key, SIZE) == 0)
+				found = 1;
+		if (!found)
+			memcpy(&tasks[task_cnt++], &next_key, SIZE);
+		key = next_key;
+	}
+
+	for (i = 0; i < task_cnt; i++) {
+		printf("\npid %d cmd %s uid %d\n",
+		       (__u32) tasks[i].pid_tgid,
+		       tasks[i].comm,
+		       (__u32) tasks[i].uid_gid);
+		print_hist_for_pid(fd, &tasks[i]);
+	}
+
+}
+
+static void int_exit(int sig)
+{
+	print_hist(map_fd[1]);
+	exit(0);
+}
+
+int main(int ac, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	long key, next_key, value;
+	struct bpf_link *links[2];
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	int i, j = 0;
+	FILE *f;
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "my_map");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "my_hist_map");
+	if (map_fd[0] < 0 || map_fd[1] < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	/* start 'ping' in the background to have some kfree_skb events */
+	f = popen("ping -4 -c5 localhost", "r");
+	(void) f;
+
+	/* start 'dd' in the background to have plenty of 'write' syscalls */
+	f = popen("dd if=/dev/zero of=/dev/null count=5000000", "r");
+	(void) f;
+
+	bpf_object__for_each_program(prog, obj) {
+		links[j] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[j])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[j] = NULL;
+			goto cleanup;
+		}
+		j++;
+	}
+
+	for (i = 0; i < 5; i++) {
+		key = 0;
+		while (bpf_map_get_next_key(map_fd[0], &key, &next_key) == 0) {
+			bpf_map_lookup_elem(map_fd[0], &next_key, &value);
+			printf("location 0x%lx count %ld\n", next_key, value);
+			key = next_key;
+		}
+		if (key)
+			printf("\n");
+		sleep(1);
+	}
+	print_hist(map_fd[1]);
+
+cleanup:
+	for (j--; j >= 0; j--)
+		bpf_link__destroy(links[j]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/tracex3_kern.c b/samples/bpf/tracex3_kern.c
new file mode 100644
index 000000000..710a4410b
--- /dev/null
+++ b/samples/bpf/tracex3_kern.c
@@ -0,0 +1,90 @@
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, long);
+	__type(value, u64);
+	__uint(max_entries, 4096);
+} my_map SEC(".maps");
+
+/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
+ * example will no longer be meaningful
+ */
+SEC("kprobe/blk_mq_start_request")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	long rq = PT_REGS_PARM1(ctx);
+	u64 val = bpf_ktime_get_ns();
+
+	bpf_map_update_elem(&my_map, &rq, &val, BPF_ANY);
+	return 0;
+}
+
+static unsigned int log2l(unsigned long long n)
+{
+#define S(k) if (n >= (1ull << k)) { i += k; n >>= k; }
+	int i = -(n == 0);
+	S(32); S(16); S(8); S(4); S(2); S(1);
+	return i;
+#undef S
+}
+
+#define SLOTS 100
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, sizeof(u64));
+	__uint(max_entries, SLOTS);
+} lat_map SEC(".maps");
+
+SEC("kprobe/blk_account_io_done")
+int bpf_prog2(struct pt_regs *ctx)
+{
+	long rq = PT_REGS_PARM1(ctx);
+	u64 *value, l, base;
+	u32 index;
+
+	value = bpf_map_lookup_elem(&my_map, &rq);
+	if (!value)
+		return 0;
+
+	u64 cur_time = bpf_ktime_get_ns();
+	u64 delta = cur_time - *value;
+
+	bpf_map_delete_elem(&my_map, &rq);
+
+	/* the lines below are computing index = log10(delta)*10
+	 * using integer arithmetic
+	 * index = 29 ~ 1 usec
+	 * index = 59 ~ 1 msec
+	 * index = 89 ~ 1 sec
+	 * index = 99 ~ 10sec or more
+	 * log10(x)*10 = log2(x)*10/log2(10) = log2(x)*3
+	 */
+	l = log2l(delta);
+	base = 1ll << l;
+	index = (l * 64 + (delta - base) * 64 / base) * 3 / 64;
+
+	if (index >= SLOTS)
+		index = SLOTS - 1;
+
+	value = bpf_map_lookup_elem(&lat_map, &index);
+	if (value)
+		*value += 1;
+
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex3_user.c b/samples/bpf/tracex3_user.c
new file mode 100644
index 000000000..83e0fecbb
--- /dev/null
+++ b/samples/bpf/tracex3_user.c
@@ -0,0 +1,190 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/resource.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "bpf_util.h"
+
+#define SLOTS 100
+
+static void clear_stats(int fd)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	__u64 values[nr_cpus];
+	__u32 key;
+
+	memset(values, 0, sizeof(values));
+	for (key = 0; key < SLOTS; key++)
+		bpf_map_update_elem(fd, &key, values, BPF_ANY);
+}
+
+const char *color[] = {
+	"\033[48;5;255m",
+	"\033[48;5;252m",
+	"\033[48;5;250m",
+	"\033[48;5;248m",
+	"\033[48;5;246m",
+	"\033[48;5;244m",
+	"\033[48;5;242m",
+	"\033[48;5;240m",
+	"\033[48;5;238m",
+	"\033[48;5;236m",
+	"\033[48;5;234m",
+	"\033[48;5;232m",
+};
+const int num_colors = ARRAY_SIZE(color);
+
+const char nocolor[] = "\033[00m";
+
+const char *sym[] = {
+	" ",
+	" ",
+	".",
+	".",
+	"*",
+	"*",
+	"o",
+	"o",
+	"O",
+	"O",
+	"#",
+	"#",
+};
+
+bool full_range = false;
+bool text_only = false;
+
+static void print_banner(void)
+{
+	if (full_range)
+		printf("|1ns     |10ns     |100ns    |1us      |10us     |100us"
+		       "    |1ms      |10ms     |100ms    |1s       |10s\n");
+	else
+		printf("|1us      |10us     |100us    |1ms      |10ms     "
+		       "|100ms    |1s       |10s\n");
+}
+
+static void print_hist(int fd)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	__u64 total_events = 0;
+	long values[nr_cpus];
+	__u64 max_cnt = 0;
+	__u64 cnt[SLOTS];
+	__u64 value;
+	__u32 key;
+	int i;
+
+	for (key = 0; key < SLOTS; key++) {
+		bpf_map_lookup_elem(fd, &key, values);
+		value = 0;
+		for (i = 0; i < nr_cpus; i++)
+			value += values[i];
+		cnt[key] = value;
+		total_events += value;
+		if (value > max_cnt)
+			max_cnt = value;
+	}
+	clear_stats(fd);
+	for (key = full_range ? 0 : 29; key < SLOTS; key++) {
+		int c = num_colors * cnt[key] / (max_cnt + 1);
+
+		if (text_only)
+			printf("%s", sym[c]);
+		else
+			printf("%s %s", color[c], nocolor);
+	}
+	printf(" # %lld\n", total_events);
+}
+
+int main(int ac, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_link *links[2];
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	int map_fd, i, j = 0;
+
+	for (i = 1; i < ac; i++) {
+		if (strcmp(argv[i], "-a") == 0) {
+			full_range = true;
+		} else if (strcmp(argv[i], "-t") == 0) {
+			text_only = true;
+		} else if (strcmp(argv[i], "-h") == 0) {
+			printf("Usage:\n"
+			       "  -a display wider latency range\n"
+			       "  -t text only\n");
+			return 1;
+		}
+	}
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "lat_map");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		links[j] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[j])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[j] = NULL;
+			goto cleanup;
+		}
+		j++;
+	}
+
+	printf("  heatmap of IO latency\n");
+	if (text_only)
+		printf("  %s", sym[num_colors - 1]);
+	else
+		printf("  %s %s", color[num_colors - 1], nocolor);
+	printf(" - many events with this latency\n");
+
+	if (text_only)
+		printf("  %s", sym[0]);
+	else
+		printf("  %s %s", color[0], nocolor);
+	printf(" - few events\n");
+
+	for (i = 0; ; i++) {
+		if (i % 20 == 0)
+			print_banner();
+		print_hist(map_fd);
+		sleep(2);
+	}
+
+cleanup:
+	for (j--; j >= 0; j--)
+		bpf_link__destroy(links[j]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/tracex4_kern.c b/samples/bpf/tracex4_kern.c
new file mode 100644
index 000000000..eb0f8fdd1
--- /dev/null
+++ b/samples/bpf/tracex4_kern.c
@@ -0,0 +1,55 @@
+/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/ptrace.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct pair {
+	u64 val;
+	u64 ip;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, long);
+	__type(value, struct pair);
+	__uint(max_entries, 1000000);
+} my_map SEC(".maps");
+
+/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
+ * example will no longer be meaningful
+ */
+SEC("kprobe/kmem_cache_free")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	long ptr = PT_REGS_PARM2(ctx);
+
+	bpf_map_delete_elem(&my_map, &ptr);
+	return 0;
+}
+
+SEC("kretprobe/kmem_cache_alloc_node")
+int bpf_prog2(struct pt_regs *ctx)
+{
+	long ptr = PT_REGS_RC(ctx);
+	long ip = 0;
+
+	/* get ip address of kmem_cache_alloc_node() caller */
+	BPF_KRETPROBE_READ_RET_IP(ip, ctx);
+
+	struct pair v = {
+		.val = bpf_ktime_get_ns(),
+		.ip = ip,
+	};
+
+	bpf_map_update_elem(&my_map, &ptr, &v, BPF_ANY);
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex4_user.c b/samples/bpf/tracex4_user.c
new file mode 100644
index 000000000..e8faf8f18
--- /dev/null
+++ b/samples/bpf/tracex4_user.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <string.h>
+#include <time.h>
+#include <sys/resource.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+struct pair {
+	long long val;
+	__u64 ip;
+};
+
+static __u64 time_get_ns(void)
+{
+	struct timespec ts;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
+}
+
+static void print_old_objects(int fd)
+{
+	long long val = time_get_ns();
+	__u64 key, next_key;
+	struct pair v;
+
+	key = write(1, "\e[1;1H\e[2J", 12); /* clear screen */
+
+	key = -1;
+	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
+		bpf_map_lookup_elem(fd, &next_key, &v);
+		key = next_key;
+		if (val - v.val < 1000000000ll)
+			/* object was allocated more then 1 sec ago */
+			continue;
+		printf("obj 0x%llx is %2lldsec old was allocated at ip %llx\n",
+		       next_key, (val - v.val) / 1000000000ll, v.ip);
+	}
+}
+
+int main(int ac, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_link *links[2];
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	int map_fd, i, j = 0;
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)");
+		return 1;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		links[j] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[j])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[j] = NULL;
+			goto cleanup;
+		}
+		j++;
+	}
+
+	for (i = 0; ; i++) {
+		print_old_objects(map_fd);
+		sleep(1);
+	}
+
+cleanup:
+	for (j--; j >= 0; j--)
+		bpf_link__destroy(links[j]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/tracex5_kern.c b/samples/bpf/tracex5_kern.c
new file mode 100644
index 000000000..64a1f7550
--- /dev/null
+++ b/samples/bpf/tracex5_kern.c
@@ -0,0 +1,93 @@
+/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/ptrace.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/seccomp.h>
+#include <uapi/linux/unistd.h>
+#include "syscall_nrs.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#define PROG(F) SEC("kprobe/"__stringify(F)) int bpf_func_##F
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, sizeof(u32));
+#ifdef __mips__
+	__uint(max_entries, 6000); /* MIPS n64 syscalls start at 5000 */
+#else
+	__uint(max_entries, 1024);
+#endif
+} progs SEC(".maps");
+
+SEC("kprobe/__seccomp_filter")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	int sc_nr = (int)PT_REGS_PARM1(ctx);
+
+	/* dispatch into next BPF program depending on syscall number */
+	bpf_tail_call(ctx, &progs, sc_nr);
+
+	/* fall through -> unknown syscall */
+	if (sc_nr >= __NR_getuid && sc_nr <= __NR_getsid) {
+		char fmt[] = "syscall=%d (one of get/set uid/pid/gid)\n";
+		bpf_trace_printk(fmt, sizeof(fmt), sc_nr);
+	}
+	return 0;
+}
+
+/* we jump here when syscall number == __NR_write */
+PROG(SYS__NR_write)(struct pt_regs *ctx)
+{
+	struct seccomp_data sd;
+
+	bpf_probe_read_kernel(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
+	if (sd.args[2] == 512) {
+		char fmt[] = "write(fd=%d, buf=%p, size=%d)\n";
+		bpf_trace_printk(fmt, sizeof(fmt),
+				 sd.args[0], sd.args[1], sd.args[2]);
+	}
+	return 0;
+}
+
+PROG(SYS__NR_read)(struct pt_regs *ctx)
+{
+	struct seccomp_data sd;
+
+	bpf_probe_read_kernel(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
+	if (sd.args[2] > 128 && sd.args[2] <= 1024) {
+		char fmt[] = "read(fd=%d, buf=%p, size=%d)\n";
+		bpf_trace_printk(fmt, sizeof(fmt),
+				 sd.args[0], sd.args[1], sd.args[2]);
+	}
+	return 0;
+}
+
+#ifdef __NR_mmap2
+PROG(SYS__NR_mmap2)(struct pt_regs *ctx)
+{
+	char fmt[] = "mmap2\n";
+
+	bpf_trace_printk(fmt, sizeof(fmt));
+	return 0;
+}
+#endif
+
+#ifdef __NR_mmap
+PROG(SYS__NR_mmap)(struct pt_regs *ctx)
+{
+	char fmt[] = "mmap\n";
+
+	bpf_trace_printk(fmt, sizeof(fmt));
+	return 0;
+}
+#endif
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex5_user.c b/samples/bpf/tracex5_user.c
new file mode 100644
index 000000000..c17d3fb5f
--- /dev/null
+++ b/samples/bpf/tracex5_user.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <linux/filter.h>
+#include <linux/seccomp.h>
+#include <sys/prctl.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include <sys/resource.h>
+#include "trace_helpers.h"
+
+#ifdef __mips__
+#define	MAX_ENTRIES  6000 /* MIPS n64 syscalls start at 5000 */
+#else
+#define	MAX_ENTRIES  1024
+#endif
+
+/* install fake seccomp program to enable seccomp code path inside the kernel,
+ * so that our kprobe attached to seccomp_phase1() can be triggered
+ */
+static void install_accept_all_seccomp(void)
+{
+	struct sock_filter filter[] = {
+		BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
+	};
+	struct sock_fprog prog = {
+		.len = (unsigned short)(sizeof(filter)/sizeof(filter[0])),
+		.filter = filter,
+	};
+	if (prctl(PR_SET_SECCOMP, 2, &prog))
+		perror("prctl");
+}
+
+int main(int ac, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	int key, fd, progs_fd;
+	const char *section;
+	char filename[256];
+	FILE *f;
+
+	setrlimit(RLIMIT_MEMLOCK, &r);
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (!prog) {
+		printf("finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	progs_fd = bpf_object__find_map_fd_by_name(obj, "progs");
+	if (progs_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		section = bpf_program__section_name(prog);
+		/* register only syscalls to PROG_ARRAY */
+		if (sscanf(section, "kprobe/%d", &key) != 1)
+			continue;
+
+		fd = bpf_program__fd(prog);
+		bpf_map_update_elem(progs_fd, &key, &fd, BPF_ANY);
+	}
+
+	install_accept_all_seccomp();
+
+	f = popen("dd if=/dev/zero of=/dev/null count=5", "r");
+	(void) f;
+
+	read_trace_pipe();
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/tracex6_kern.c b/samples/bpf/tracex6_kern.c
new file mode 100644
index 000000000..fd602c277
--- /dev/null
+++ b/samples/bpf/tracex6_kern.c
@@ -0,0 +1,82 @@
+#include <linux/ptrace.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(u32));
+	__uint(max_entries, 64);
+} counters SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, int);
+	__type(value, u64);
+	__uint(max_entries, 64);
+} values SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, int);
+	__type(value, struct bpf_perf_event_value);
+	__uint(max_entries, 64);
+} values2 SEC(".maps");
+
+SEC("kprobe/htab_map_get_next_key")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	u32 key = bpf_get_smp_processor_id();
+	u64 count, *val;
+	s64 error;
+
+	count = bpf_perf_event_read(&counters, key);
+	error = (s64)count;
+	if (error <= -2 && error >= -22)
+		return 0;
+
+	val = bpf_map_lookup_elem(&values, &key);
+	if (val)
+		*val = count;
+	else
+		bpf_map_update_elem(&values, &key, &count, BPF_NOEXIST);
+
+	return 0;
+}
+
+/*
+ * Since *_map_lookup_elem can't be expected to trigger bpf programs
+ * due to potential deadlocks (bpf_disable_instrumentation), this bpf
+ * program will be attached to bpf_map_copy_value (which is called
+ * from map_lookup_elem) and will only filter the hashtable type.
+ */
+SEC("kprobe/bpf_map_copy_value")
+int BPF_KPROBE(bpf_prog2, struct bpf_map *map)
+{
+	u32 key = bpf_get_smp_processor_id();
+	struct bpf_perf_event_value *val, buf;
+	enum bpf_map_type type;
+	int error;
+
+	type = BPF_CORE_READ(map, map_type);
+	if (type != BPF_MAP_TYPE_HASH)
+		return 0;
+
+	error = bpf_perf_event_read_value(&counters, key, &buf, sizeof(buf));
+	if (error)
+		return 0;
+
+	val = bpf_map_lookup_elem(&values2, &key);
+	if (val)
+		*val = buf;
+	else
+		bpf_map_update_elem(&values2, &key, &buf, BPF_NOEXIST);
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex6_user.c b/samples/bpf/tracex6_user.c
new file mode 100644
index 000000000..33df97847
--- /dev/null
+++ b/samples/bpf/tracex6_user.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+
+#include <assert.h>
+#include <fcntl.h>
+#include <linux/perf_event.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/resource.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "perf-sys.h"
+
+#define SAMPLE_PERIOD  0x7fffffffffffffffULL
+
+/* counters, values, values2 */
+static int map_fd[3];
+
+static void check_on_cpu(int cpu, struct perf_event_attr *attr)
+{
+	struct bpf_perf_event_value value2;
+	int pmu_fd, error = 0;
+	cpu_set_t set;
+	__u64 value;
+
+	/* Move to target CPU */
+	CPU_ZERO(&set);
+	CPU_SET(cpu, &set);
+	assert(sched_setaffinity(0, sizeof(set), &set) == 0);
+	/* Open perf event and attach to the perf_event_array */
+	pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0);
+	if (pmu_fd < 0) {
+		fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
+		error = 1;
+		goto on_exit;
+	}
+	assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
+	assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
+	/* Trigger the kprobe */
+	bpf_map_get_next_key(map_fd[1], &cpu, NULL);
+	/* Check the value */
+	if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
+		fprintf(stderr, "Value missing for CPU %d\n", cpu);
+		error = 1;
+		goto on_exit;
+	} else {
+		fprintf(stderr, "CPU %d: %llu\n", cpu, value);
+	}
+	/* The above bpf_map_lookup_elem should trigger the second kprobe */
+	if (bpf_map_lookup_elem(map_fd[2], &cpu, &value2)) {
+		fprintf(stderr, "Value2 missing for CPU %d\n", cpu);
+		error = 1;
+		goto on_exit;
+	} else {
+		fprintf(stderr, "CPU %d: counter: %llu, enabled: %llu, running: %llu\n", cpu,
+			value2.counter, value2.enabled, value2.running);
+	}
+
+on_exit:
+	assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
+	assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
+	assert(close(pmu_fd) == 0 || error);
+	assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
+	exit(error);
+}
+
+static void test_perf_event_array(struct perf_event_attr *attr,
+				  const char *name)
+{
+	int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+	pid_t pid[nr_cpus];
+	int err = 0;
+
+	printf("Test reading %s counters\n", name);
+
+	for (i = 0; i < nr_cpus; i++) {
+		pid[i] = fork();
+		assert(pid[i] >= 0);
+		if (pid[i] == 0) {
+			check_on_cpu(i, attr);
+			exit(1);
+		}
+	}
+
+	for (i = 0; i < nr_cpus; i++) {
+		assert(waitpid(pid[i], &status, 0) == pid[i]);
+		err |= status;
+	}
+
+	if (err)
+		printf("Test: %s FAILED\n", name);
+}
+
+static void test_bpf_perf_event(void)
+{
+	struct perf_event_attr attr_cycles = {
+		.freq = 0,
+		.sample_period = SAMPLE_PERIOD,
+		.inherit = 0,
+		.type = PERF_TYPE_HARDWARE,
+		.read_format = 0,
+		.sample_type = 0,
+		.config = PERF_COUNT_HW_CPU_CYCLES,
+	};
+	struct perf_event_attr attr_clock = {
+		.freq = 0,
+		.sample_period = SAMPLE_PERIOD,
+		.inherit = 0,
+		.type = PERF_TYPE_SOFTWARE,
+		.read_format = 0,
+		.sample_type = 0,
+		.config = PERF_COUNT_SW_CPU_CLOCK,
+	};
+	struct perf_event_attr attr_raw = {
+		.freq = 0,
+		.sample_period = SAMPLE_PERIOD,
+		.inherit = 0,
+		.type = PERF_TYPE_RAW,
+		.read_format = 0,
+		.sample_type = 0,
+		/* Intel Instruction Retired */
+		.config = 0xc0,
+	};
+	struct perf_event_attr attr_l1d_load = {
+		.freq = 0,
+		.sample_period = SAMPLE_PERIOD,
+		.inherit = 0,
+		.type = PERF_TYPE_HW_CACHE,
+		.read_format = 0,
+		.sample_type = 0,
+		.config =
+			PERF_COUNT_HW_CACHE_L1D |
+			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
+			(PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
+	};
+	struct perf_event_attr attr_llc_miss = {
+		.freq = 0,
+		.sample_period = SAMPLE_PERIOD,
+		.inherit = 0,
+		.type = PERF_TYPE_HW_CACHE,
+		.read_format = 0,
+		.sample_type = 0,
+		.config =
+			PERF_COUNT_HW_CACHE_LL |
+			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
+			(PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
+	};
+	struct perf_event_attr attr_msr_tsc = {
+		.freq = 0,
+		.sample_period = 0,
+		.inherit = 0,
+		/* From /sys/bus/event_source/devices/msr/ */
+		.type = 7,
+		.read_format = 0,
+		.sample_type = 0,
+		.config = 0,
+	};
+
+	test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
+	test_perf_event_array(&attr_clock, "SOFTWARE-clock");
+	test_perf_event_array(&attr_raw, "RAW-instruction-retired");
+	test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
+
+	/* below tests may fail in qemu */
+	test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
+	test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_link *links[2];
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	int i = 0;
+
+	setrlimit(RLIMIT_MEMLOCK, &r);
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counters");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "values");
+	map_fd[2] = bpf_object__find_map_fd_by_name(obj, "values2");
+	if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		links[i] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[i])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[i] = NULL;
+			goto cleanup;
+		}
+		i++;
+	}
+
+	test_bpf_perf_event();
+
+cleanup:
+	for (i--; i >= 0; i--)
+		bpf_link__destroy(links[i]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/tracex7_kern.c b/samples/bpf/tracex7_kern.c
new file mode 100644
index 000000000..c5a92df8a
--- /dev/null
+++ b/samples/bpf/tracex7_kern.c
@@ -0,0 +1,16 @@
+#include <uapi/linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+
+SEC("kprobe/open_ctree")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	unsigned long rc = -12;
+
+	bpf_override_return(ctx, rc);
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex7_user.c b/samples/bpf/tracex7_user.c
new file mode 100644
index 000000000..8be7ce18d
--- /dev/null
+++ b/samples/bpf/tracex7_user.c
@@ -0,0 +1,56 @@
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <unistd.h>
+#include <bpf/libbpf.h>
+
+int main(int argc, char **argv)
+{
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	char command[256];
+	int ret = 0;
+	FILE *f;
+
+	if (!argv[1]) {
+		fprintf(stderr, "ERROR: Run with the btrfs device argument!\n");
+		return 0;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (!prog) {
+		fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	snprintf(command, 256, "mount %s tmpmnt/", argv[1]);
+	f = popen(command, "r");
+	ret = pclose(f);
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return ret ? 0 : 1;
+}
diff --git a/samples/bpf/xdp1_kern.c b/samples/bpf/xdp1_kern.c
new file mode 100644
index 000000000..34b64394e
--- /dev/null
+++ b/samples/bpf/xdp1_kern.c
@@ -0,0 +1,93 @@
+/* Copyright (c) 2016 PLUMgrid
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, 256);
+} rxcnt SEC(".maps");
+
+static int parse_ipv4(void *data, u64 nh_off, void *data_end)
+{
+	struct iphdr *iph = data + nh_off;
+
+	if (iph + 1 > data_end)
+		return 0;
+	return iph->protocol;
+}
+
+static int parse_ipv6(void *data, u64 nh_off, void *data_end)
+{
+	struct ipv6hdr *ip6h = data + nh_off;
+
+	if (ip6h + 1 > data_end)
+		return 0;
+	return ip6h->nexthdr;
+}
+
+SEC("xdp1")
+int xdp_prog1(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	int rc = XDP_DROP;
+	long *value;
+	u16 h_proto;
+	u64 nh_off;
+	u32 ipproto;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return rc;
+
+	h_proto = eth->h_proto;
+
+	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return rc;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return rc;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+
+	if (h_proto == htons(ETH_P_IP))
+		ipproto = parse_ipv4(data, nh_off, data_end);
+	else if (h_proto == htons(ETH_P_IPV6))
+		ipproto = parse_ipv6(data, nh_off, data_end);
+	else
+		ipproto = 0;
+
+	value = bpf_map_lookup_elem(&rxcnt, &ipproto);
+	if (value)
+		*value += 1;
+
+	return rc;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp1_user.c b/samples/bpf/xdp1_user.c
new file mode 100644
index 000000000..c447ad9e3
--- /dev/null
+++ b/samples/bpf/xdp1_user.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 PLUMgrid
+ */
+#include <linux/bpf.h>
+#include <linux/if_link.h>
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <libgen.h>
+#include <sys/resource.h>
+#include <net/if.h>
+
+#include "bpf_util.h"
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+static int ifindex;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static __u32 prog_id;
+
+static void int_exit(int sig)
+{
+	__u32 curr_prog_id = 0;
+
+	if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
+		printf("bpf_get_link_xdp_id failed\n");
+		exit(1);
+	}
+	if (prog_id == curr_prog_id)
+		bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
+	else if (!curr_prog_id)
+		printf("couldn't find a prog id on a given interface\n");
+	else
+		printf("program on interface changed, not removing\n");
+	exit(0);
+}
+
+/* simple per-protocol drop counter
+ */
+static void poll_stats(int map_fd, int interval)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	__u64 values[nr_cpus], prev[UINT8_MAX] = { 0 };
+	int i;
+
+	while (1) {
+		__u32 key = UINT32_MAX;
+
+		sleep(interval);
+
+		while (bpf_map_get_next_key(map_fd, &key, &key) != -1) {
+			__u64 sum = 0;
+
+			assert(bpf_map_lookup_elem(map_fd, &key, values) == 0);
+			for (i = 0; i < nr_cpus; i++)
+				sum += values[i];
+			if (sum > prev[key])
+				printf("proto %u: %10llu pkt/s\n",
+				       key, (sum - prev[key]) / interval);
+			prev[key] = sum;
+		}
+	}
+}
+
+static void usage(const char *prog)
+{
+	fprintf(stderr,
+		"usage: %s [OPTS] IFACE\n\n"
+		"OPTS:\n"
+		"    -S    use skb-mode\n"
+		"    -N    enforce native mode\n"
+		"    -F    force loading prog\n",
+		prog);
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type	= BPF_PROG_TYPE_XDP,
+	};
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	const char *optstr = "FSN";
+	int prog_fd, map_fd, opt;
+	struct bpf_object *obj;
+	struct bpf_map *map;
+	char filename[256];
+	int err;
+
+	while ((opt = getopt(argc, argv, optstr)) != -1) {
+		switch (opt) {
+		case 'S':
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
+			break;
+		case 'N':
+			/* default, set below */
+			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		default:
+			usage(basename(argv[0]));
+			return 1;
+		}
+	}
+
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	if (optind == argc) {
+		usage(basename(argv[0]));
+		return 1;
+	}
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	ifindex = if_nametoindex(argv[optind]);
+	if (!ifindex) {
+		perror("if_nametoindex");
+		return 1;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	prog_load_attr.file = filename;
+
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+		return 1;
+
+	map = bpf_map__next(NULL, obj);
+	if (!map) {
+		printf("finding a map in obj file failed\n");
+		return 1;
+	}
+	map_fd = bpf_map__fd(map);
+
+	if (!prog_fd) {
+		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
+		return 1;
+	}
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
+		printf("link set xdp fd failed\n");
+		return 1;
+	}
+
+	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
+	if (err) {
+		printf("can't get prog info - %s\n", strerror(errno));
+		return err;
+	}
+	prog_id = info.id;
+
+	poll_stats(map_fd, 2);
+
+	return 0;
+}
diff --git a/samples/bpf/xdp2_kern.c b/samples/bpf/xdp2_kern.c
new file mode 100644
index 000000000..c787f4b49
--- /dev/null
+++ b/samples/bpf/xdp2_kern.c
@@ -0,0 +1,114 @@
+/* Copyright (c) 2016 PLUMgrid
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, 256);
+} rxcnt SEC(".maps");
+
+static void swap_src_dst_mac(void *data)
+{
+	unsigned short *p = data;
+	unsigned short dst[3];
+
+	dst[0] = p[0];
+	dst[1] = p[1];
+	dst[2] = p[2];
+	p[0] = p[3];
+	p[1] = p[4];
+	p[2] = p[5];
+	p[3] = dst[0];
+	p[4] = dst[1];
+	p[5] = dst[2];
+}
+
+static int parse_ipv4(void *data, u64 nh_off, void *data_end)
+{
+	struct iphdr *iph = data + nh_off;
+
+	if (iph + 1 > data_end)
+		return 0;
+	return iph->protocol;
+}
+
+static int parse_ipv6(void *data, u64 nh_off, void *data_end)
+{
+	struct ipv6hdr *ip6h = data + nh_off;
+
+	if (ip6h + 1 > data_end)
+		return 0;
+	return ip6h->nexthdr;
+}
+
+SEC("xdp1")
+int xdp_prog1(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	int rc = XDP_DROP;
+	long *value;
+	u16 h_proto;
+	u64 nh_off;
+	u32 ipproto;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return rc;
+
+	h_proto = eth->h_proto;
+
+	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return rc;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return rc;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+
+	if (h_proto == htons(ETH_P_IP))
+		ipproto = parse_ipv4(data, nh_off, data_end);
+	else if (h_proto == htons(ETH_P_IPV6))
+		ipproto = parse_ipv6(data, nh_off, data_end);
+	else
+		ipproto = 0;
+
+	value = bpf_map_lookup_elem(&rxcnt, &ipproto);
+	if (value)
+		*value += 1;
+
+	if (ipproto == IPPROTO_UDP) {
+		swap_src_dst_mac(data);
+		rc = XDP_TX;
+	}
+
+	return rc;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp2skb_meta.sh b/samples/bpf/xdp2skb_meta.sh
new file mode 100755
index 000000000..4bde9d066
--- /dev/null
+++ b/samples/bpf/xdp2skb_meta.sh
@@ -0,0 +1,220 @@
+#!/bin/bash
+#
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2018 Jesper Dangaard Brouer, Red Hat Inc.
+#
+# Bash-shell example on using iproute2 tools 'tc' and 'ip' to load
+# eBPF programs, both for XDP and clsbpf.  Shell script function
+# wrappers and even long options parsing is illustrated, for ease of
+# use.
+#
+# Related to sample/bpf/xdp2skb_meta_kern.c, which contains BPF-progs
+# that need to collaborate between XDP and TC hooks.  Thus, it is
+# convenient that the same tool load both programs that need to work
+# together.
+#
+BPF_FILE=xdp2skb_meta_kern.o
+DIR=$(dirname $0)
+
+[ -z "$TC" ] && TC=tc
+[ -z "$IP" ] && IP=ip
+
+function usage() {
+    echo ""
+    echo "Usage: $0 [-vfh] --dev ethX"
+    echo "  -d | --dev     :             Network device (required)"
+    echo "  --flush        :             Cleanup flush TC and XDP progs"
+    echo "  --list         : (\$LIST)     List TC and XDP progs"
+    echo "  -v | --verbose : (\$VERBOSE)  Verbose"
+    echo "  --dry-run      : (\$DRYRUN)   Dry-run only (echo commands)"
+    echo ""
+}
+
+## -- General shell logging cmds --
+function err() {
+    local exitcode=$1
+    shift
+    echo "ERROR: $@" >&2
+    exit $exitcode
+}
+
+function info() {
+    if [[ -n "$VERBOSE" ]]; then
+	echo "# $@"
+    fi
+}
+
+## -- Helper function calls --
+
+# Wrapper call for TC and IP
+# - Will display the offending command on failure
+function _call_cmd() {
+    local cmd="$1"
+    local allow_fail="$2"
+    shift 2
+    if [[ -n "$VERBOSE" ]]; then
+	echo "$cmd $@"
+    fi
+    if [[ -n "$DRYRUN" ]]; then
+	return
+    fi
+    $cmd "$@"
+    local status=$?
+    if (( $status != 0 )); then
+	if [[ "$allow_fail" == "" ]]; then
+	    err 2 "Exec error($status) occurred cmd: \"$cmd $@\""
+	fi
+    fi
+}
+function call_tc() {
+    _call_cmd "$TC" "" "$@"
+}
+function call_tc_allow_fail() {
+    _call_cmd "$TC" "allow_fail" "$@"
+}
+function call_ip() {
+    _call_cmd "$IP" "" "$@"
+}
+
+##  --- Parse command line arguments / parameters ---
+# Using external program "getopt" to get --long-options
+OPTIONS=$(getopt -o vfhd: \
+    --long verbose,flush,help,list,dev:,dry-run -- "$@")
+if (( $? != 0 )); then
+    err 4 "Error calling getopt"
+fi
+eval set -- "$OPTIONS"
+
+unset DEV
+unset FLUSH
+while true; do
+    case "$1" in
+	-d | --dev ) # device
+	    DEV=$2
+	    info "Device set to: DEV=$DEV" >&2
+	    shift 2
+	    ;;
+	-v | --verbose)
+	    VERBOSE=yes
+	    # info "Verbose mode: VERBOSE=$VERBOSE" >&2
+	    shift
+	    ;;
+	--dry-run )
+	    DRYRUN=yes
+	    VERBOSE=yes
+	    info "Dry-run mode: enable VERBOSE and don't call TC+IP" >&2
+	    shift
+            ;;
+	-f | --flush )
+	    FLUSH=yes
+	    shift
+	    ;;
+	--list )
+	    LIST=yes
+	    shift
+	    ;;
+	-- )
+	    shift
+	    break
+	    ;;
+	-h | --help )
+	    usage;
+	    exit 0
+	    ;;
+	* )
+	    shift
+	    break
+	    ;;
+    esac
+done
+
+FILE="$DIR/$BPF_FILE"
+if [[ ! -e $FILE ]]; then
+    err 3 "Missing BPF object file ($FILE)"
+fi
+
+if [[ -z $DEV ]]; then
+    usage
+    err 2 "Please specify network device -- required option --dev"
+fi
+
+## -- Function calls --
+
+function list_tc()
+{
+    local device="$1"
+    shift
+    info "Listing current TC ingress rules"
+    call_tc filter show dev $device ingress
+}
+
+function list_xdp()
+{
+    local device="$1"
+    shift
+    info "Listing current XDP device($device) setting"
+    call_ip link show dev $device | grep --color=auto xdp
+}
+
+function flush_tc()
+{
+    local device="$1"
+    shift
+    info "Flush TC on device: $device"
+    call_tc_allow_fail filter del dev $device ingress
+    call_tc_allow_fail qdisc del dev $device clsact
+}
+
+function flush_xdp()
+{
+    local device="$1"
+    shift
+    info "Flush XDP on device: $device"
+    call_ip link set dev $device xdp off
+}
+
+function attach_tc_mark()
+{
+    local device="$1"
+    local file="$2"
+    local prog="tc_mark"
+    shift 2
+
+    # Re-attach clsact to clear/flush existing role
+    call_tc_allow_fail qdisc del dev $device clsact 2> /dev/null
+    call_tc            qdisc add dev $device clsact
+
+    # Attach BPF prog
+    call_tc filter add dev $device ingress \
+	    prio 1 handle 1 bpf da obj $file sec $prog
+}
+
+function attach_xdp_mark()
+{
+    local device="$1"
+    local file="$2"
+    local prog="xdp_mark"
+    shift 2
+
+    # Remove XDP prog in-case it's already loaded
+    # TODO: Need ip-link option to override/replace existing XDP prog
+    flush_xdp $device
+
+    # Attach XDP/BPF prog
+    call_ip link set dev $device xdp obj $file sec $prog
+}
+
+if [[ -n $FLUSH ]]; then
+    flush_tc  $DEV
+    flush_xdp $DEV
+    exit 0
+fi
+
+if [[ -n $LIST ]]; then
+    list_tc  $DEV
+    list_xdp $DEV
+    exit 0
+fi
+
+attach_tc_mark  $DEV $FILE
+attach_xdp_mark $DEV $FILE
diff --git a/samples/bpf/xdp2skb_meta_kern.c b/samples/bpf/xdp2skb_meta_kern.c
new file mode 100644
index 000000000..9b783316e
--- /dev/null
+++ b/samples/bpf/xdp2skb_meta_kern.c
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Copyright (c) 2018 Jesper Dangaard Brouer, Red Hat Inc.
+ *
+ * Example howto transfer info from XDP to SKB, e.g. skb->mark
+ * -----------------------------------------------------------
+ * This uses the XDP data_meta infrastructure, and is a cooperation
+ * between two bpf-programs (1) XDP and (2) clsact at TC-ingress hook.
+ *
+ * Notice: This example does not use the BPF C-loader (bpf_load.c),
+ * but instead rely on the iproute2 TC tool for loading BPF-objects.
+ */
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/pkt_cls.h>
+
+#include <bpf/bpf_helpers.h>
+
+/*
+ * This struct is stored in the XDP 'data_meta' area, which is located
+ * just in-front-of the raw packet payload data.  The meaning is
+ * specific to these two BPF programs that use it as a communication
+ * channel.  XDP adjust/increase the area via a bpf-helper, and TC use
+ * boundary checks to see if data have been provided.
+ *
+ * The struct must be 4 byte aligned, which here is enforced by the
+ * struct __attribute__((aligned(4))).
+ */
+struct meta_info {
+	__u32 mark;
+} __attribute__((aligned(4)));
+
+SEC("xdp_mark")
+int _xdp_mark(struct xdp_md *ctx)
+{
+	struct meta_info *meta;
+	void *data, *data_end;
+	int ret;
+
+	/* Reserve space in-front of data pointer for our meta info.
+	 * (Notice drivers not supporting data_meta will fail here!)
+	 */
+	ret = bpf_xdp_adjust_meta(ctx, -(int)sizeof(*meta));
+	if (ret < 0)
+		return XDP_ABORTED;
+
+	/* Notice: Kernel-side verifier requires that loading of
+	 * ctx->data MUST happen _after_ helper bpf_xdp_adjust_meta(),
+	 * as pkt-data pointers are invalidated.  Helpers that require
+	 * this are determined/marked by bpf_helper_changes_pkt_data()
+	 */
+	data = (void *)(unsigned long)ctx->data;
+
+	/* Check data_meta have room for meta_info struct */
+	meta = (void *)(unsigned long)ctx->data_meta;
+	if (meta + 1 > data)
+		return XDP_ABORTED;
+
+	meta->mark = 42;
+
+	return XDP_PASS;
+}
+
+SEC("tc_mark")
+int _tc_mark(struct __sk_buff *ctx)
+{
+	void *data      = (void *)(unsigned long)ctx->data;
+	void *data_end  = (void *)(unsigned long)ctx->data_end;
+	void *data_meta = (void *)(unsigned long)ctx->data_meta;
+	struct meta_info *meta = data_meta;
+
+	/* Check XDP gave us some data_meta */
+	if (meta + 1 > data) {
+		ctx->mark = 41;
+		 /* Skip "accept" if no data_meta is avail */
+		return TC_ACT_OK;
+	}
+
+	/* Hint: See func tc_cls_act_is_valid_access() for BPF_WRITE access */
+	ctx->mark = meta->mark; /* Transfer XDP-mark to SKB-mark */
+
+	return TC_ACT_OK;
+}
+
+/* Manually attaching these programs:
+export DEV=ixgbe2
+export FILE=xdp2skb_meta_kern.o
+
+# via TC command
+tc qdisc del dev $DEV clsact 2> /dev/null
+tc qdisc add dev $DEV clsact
+tc filter  add dev $DEV ingress prio 1 handle 1 bpf da obj $FILE sec tc_mark
+tc filter show dev $DEV ingress
+
+# XDP via IP command:
+ip link set dev $DEV xdp off
+ip link set dev $DEV xdp obj $FILE sec xdp_mark
+
+# Use iptable to "see" if SKBs are marked
+iptables -I INPUT -p icmp -m mark --mark 41  # == 0x29
+iptables -I INPUT -p icmp -m mark --mark 42  # == 0x2a
+
+# Hint: catch XDP_ABORTED errors via
+perf record -e xdp:*
+perf script
+
+*/
diff --git a/samples/bpf/xdp_adjust_tail_kern.c b/samples/bpf/xdp_adjust_tail_kern.c
new file mode 100644
index 000000000..ffdd54862
--- /dev/null
+++ b/samples/bpf/xdp_adjust_tail_kern.c
@@ -0,0 +1,155 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Copyright (c) 2018 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program shows how to use bpf_xdp_adjust_tail() by
+ * generating ICMPv4 "packet to big" (unreachable/ df bit set frag needed
+ * to be more preice in case of v4)" where receiving packets bigger then
+ * 600 bytes.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/icmp.h>
+#include <bpf/bpf_helpers.h>
+
+#define DEFAULT_TTL 64
+#define MAX_PCKT_SIZE 600
+#define ICMP_TOOBIG_SIZE 98
+#define ICMP_TOOBIG_PAYLOAD_SIZE 92
+
+/* volatile to prevent compiler optimizations */
+static volatile __u32 max_pcktsz = MAX_PCKT_SIZE;
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, __u32);
+	__type(value, __u64);
+	__uint(max_entries, 1);
+} icmpcnt SEC(".maps");
+
+static __always_inline void count_icmp(void)
+{
+	u64 key = 0;
+	u64 *icmp_count;
+
+	icmp_count = bpf_map_lookup_elem(&icmpcnt, &key);
+	if (icmp_count)
+		*icmp_count += 1;
+}
+
+static __always_inline void swap_mac(void *data, struct ethhdr *orig_eth)
+{
+	struct ethhdr *eth;
+
+	eth = data;
+	memcpy(eth->h_source, orig_eth->h_dest, ETH_ALEN);
+	memcpy(eth->h_dest, orig_eth->h_source, ETH_ALEN);
+	eth->h_proto = orig_eth->h_proto;
+}
+
+static __always_inline __u16 csum_fold_helper(__u32 csum)
+{
+	return ~((csum & 0xffff) + (csum >> 16));
+}
+
+static __always_inline void ipv4_csum(void *data_start, int data_size,
+				      __u32 *csum)
+{
+	*csum = bpf_csum_diff(0, 0, data_start, data_size, *csum);
+	*csum = csum_fold_helper(*csum);
+}
+
+static __always_inline int send_icmp4_too_big(struct xdp_md *xdp)
+{
+	int headroom = (int)sizeof(struct iphdr) + (int)sizeof(struct icmphdr);
+
+	if (bpf_xdp_adjust_head(xdp, 0 - headroom))
+		return XDP_DROP;
+	void *data = (void *)(long)xdp->data;
+	void *data_end = (void *)(long)xdp->data_end;
+
+	if (data + (ICMP_TOOBIG_SIZE + headroom) > data_end)
+		return XDP_DROP;
+
+	struct iphdr *iph, *orig_iph;
+	struct icmphdr *icmp_hdr;
+	struct ethhdr *orig_eth;
+	__u32 csum = 0;
+	__u64 off = 0;
+
+	orig_eth = data + headroom;
+	swap_mac(data, orig_eth);
+	off += sizeof(struct ethhdr);
+	iph = data + off;
+	off += sizeof(struct iphdr);
+	icmp_hdr = data + off;
+	off += sizeof(struct icmphdr);
+	orig_iph = data + off;
+	icmp_hdr->type = ICMP_DEST_UNREACH;
+	icmp_hdr->code = ICMP_FRAG_NEEDED;
+	icmp_hdr->un.frag.mtu = htons(max_pcktsz - sizeof(struct ethhdr));
+	icmp_hdr->checksum = 0;
+	ipv4_csum(icmp_hdr, ICMP_TOOBIG_PAYLOAD_SIZE, &csum);
+	icmp_hdr->checksum = csum;
+	iph->ttl = DEFAULT_TTL;
+	iph->daddr = orig_iph->saddr;
+	iph->saddr = orig_iph->daddr;
+	iph->version = 4;
+	iph->ihl = 5;
+	iph->protocol = IPPROTO_ICMP;
+	iph->tos = 0;
+	iph->tot_len = htons(
+		ICMP_TOOBIG_SIZE + headroom - sizeof(struct ethhdr));
+	iph->check = 0;
+	csum = 0;
+	ipv4_csum(iph, sizeof(struct iphdr), &csum);
+	iph->check = csum;
+	count_icmp();
+	return XDP_TX;
+}
+
+
+static __always_inline int handle_ipv4(struct xdp_md *xdp)
+{
+	void *data_end = (void *)(long)xdp->data_end;
+	void *data = (void *)(long)xdp->data;
+	int pckt_size = data_end - data;
+	int offset;
+
+	if (pckt_size > max(max_pcktsz, ICMP_TOOBIG_SIZE)) {
+		offset = pckt_size - ICMP_TOOBIG_SIZE;
+		if (bpf_xdp_adjust_tail(xdp, 0 - offset))
+			return XDP_PASS;
+		return send_icmp4_too_big(xdp);
+	}
+	return XDP_PASS;
+}
+
+SEC("xdp_icmp")
+int _xdp_icmp(struct xdp_md *xdp)
+{
+	void *data_end = (void *)(long)xdp->data_end;
+	void *data = (void *)(long)xdp->data;
+	struct ethhdr *eth = data;
+	__u16 h_proto;
+
+	if (eth + 1 > data_end)
+		return XDP_DROP;
+
+	h_proto = eth->h_proto;
+
+	if (h_proto == htons(ETH_P_IP))
+		return handle_ipv4(xdp);
+	else
+		return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp_adjust_tail_user.c b/samples/bpf/xdp_adjust_tail_user.c
new file mode 100644
index 000000000..ba482dc3d
--- /dev/null
+++ b/samples/bpf/xdp_adjust_tail_user.c
@@ -0,0 +1,198 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Copyright (c) 2018 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/bpf.h>
+#include <linux/if_link.h>
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <net/if.h>
+#include <sys/resource.h>
+#include <arpa/inet.h>
+#include <netinet/ether.h>
+#include <unistd.h>
+#include <time.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#define STATS_INTERVAL_S 2U
+#define MAX_PCKT_SIZE 600
+
+static int ifindex = -1;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static __u32 prog_id;
+
+static void int_exit(int sig)
+{
+	__u32 curr_prog_id = 0;
+
+	if (ifindex > -1) {
+		if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
+			printf("bpf_get_link_xdp_id failed\n");
+			exit(1);
+		}
+		if (prog_id == curr_prog_id)
+			bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
+		else if (!curr_prog_id)
+			printf("couldn't find a prog id on a given iface\n");
+		else
+			printf("program on interface changed, not removing\n");
+	}
+	exit(0);
+}
+
+/* simple "icmp packet too big sent" counter
+ */
+static void poll_stats(unsigned int map_fd, unsigned int kill_after_s)
+{
+	time_t started_at = time(NULL);
+	__u64 value = 0;
+	int key = 0;
+
+
+	while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {
+		sleep(STATS_INTERVAL_S);
+
+		assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
+
+		printf("icmp \"packet too big\" sent: %10llu pkts\n", value);
+	}
+}
+
+static void usage(const char *cmd)
+{
+	printf("Start a XDP prog which send ICMP \"packet too big\" \n"
+		"messages if ingress packet is bigger then MAX_SIZE bytes\n");
+	printf("Usage: %s [...]\n", cmd);
+	printf("    -i <ifname|ifindex> Interface\n");
+	printf("    -T <stop-after-X-seconds> Default: 0 (forever)\n");
+	printf("    -P <MAX_PCKT_SIZE> Default: %u\n", MAX_PCKT_SIZE);
+	printf("    -S use skb-mode\n");
+	printf("    -N enforce native mode\n");
+	printf("    -F force loading prog\n");
+	printf("    -h Display this help\n");
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type	= BPF_PROG_TYPE_XDP,
+	};
+	unsigned char opt_flags[256] = {};
+	const char *optstr = "i:T:P:SNFh";
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	unsigned int kill_after_s = 0;
+	int i, prog_fd, map_fd, opt;
+	struct bpf_object *obj;
+	__u32 max_pckt_size = 0;
+	__u32 key = 0;
+	char filename[256];
+	int err;
+
+	for (i = 0; i < strlen(optstr); i++)
+		if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
+			opt_flags[(unsigned char)optstr[i]] = 1;
+
+	while ((opt = getopt(argc, argv, optstr)) != -1) {
+
+		switch (opt) {
+		case 'i':
+			ifindex = if_nametoindex(optarg);
+			if (!ifindex)
+				ifindex = atoi(optarg);
+			break;
+		case 'T':
+			kill_after_s = atoi(optarg);
+			break;
+		case 'P':
+			max_pckt_size = atoi(optarg);
+			break;
+		case 'S':
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
+			break;
+		case 'N':
+			/* default, set below */
+			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		default:
+			usage(argv[0]);
+			return 1;
+		}
+		opt_flags[opt] = 0;
+	}
+
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	for (i = 0; i < strlen(optstr); i++) {
+		if (opt_flags[(unsigned int)optstr[i]]) {
+			fprintf(stderr, "Missing argument -%c\n", optstr[i]);
+			usage(argv[0]);
+			return 1;
+		}
+	}
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)");
+		return 1;
+	}
+
+	if (!ifindex) {
+		fprintf(stderr, "Invalid ifname\n");
+		return 1;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	prog_load_attr.file = filename;
+
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+		return 1;
+
+	/* static global var 'max_pcktsz' is accessible from .data section */
+	if (max_pckt_size) {
+		map_fd = bpf_object__find_map_fd_by_name(obj, "xdp_adju.data");
+		if (map_fd < 0) {
+			printf("finding a max_pcktsz map in obj file failed\n");
+			return 1;
+		}
+		bpf_map_update_elem(map_fd, &key, &max_pckt_size, BPF_ANY);
+	}
+
+	/* fetch icmpcnt map */
+	map_fd = bpf_object__find_map_fd_by_name(obj, "icmpcnt");
+	if (map_fd < 0) {
+		printf("finding a icmpcnt map in obj file failed\n");
+		return 1;
+	}
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
+		printf("link set xdp fd failed\n");
+		return 1;
+	}
+
+	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
+	if (err) {
+		printf("can't get prog info - %s\n", strerror(errno));
+		return 1;
+	}
+	prog_id = info.id;
+
+	poll_stats(map_fd, kill_after_s);
+	int_exit(0);
+
+	return 0;
+}
diff --git a/samples/bpf/xdp_fwd_kern.c b/samples/bpf/xdp_fwd_kern.c
new file mode 100644
index 000000000..54c099cbd
--- /dev/null
+++ b/samples/bpf/xdp_fwd_kern.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2017-18 David Ahern <dsahern@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+
+#include <bpf/bpf_helpers.h>
+
+#define IPV6_FLOWINFO_MASK              cpu_to_be32(0x0FFFFFFF)
+
+struct {
+	__uint(type, BPF_MAP_TYPE_DEVMAP);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(int));
+	__uint(max_entries, 64);
+} xdp_tx_ports SEC(".maps");
+
+/* from include/net/ip.h */
+static __always_inline int ip_decrease_ttl(struct iphdr *iph)
+{
+	u32 check = (__force u32)iph->check;
+
+	check += (__force u32)htons(0x0100);
+	iph->check = (__force __sum16)(check + (check >= 0xFFFF));
+	return --iph->ttl;
+}
+
+static __always_inline int xdp_fwd_flags(struct xdp_md *ctx, u32 flags)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct bpf_fib_lookup fib_params;
+	struct ethhdr *eth = data;
+	struct ipv6hdr *ip6h;
+	struct iphdr *iph;
+	u16 h_proto;
+	u64 nh_off;
+	int rc;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return XDP_DROP;
+
+	__builtin_memset(&fib_params, 0, sizeof(fib_params));
+
+	h_proto = eth->h_proto;
+	if (h_proto == htons(ETH_P_IP)) {
+		iph = data + nh_off;
+
+		if (iph + 1 > data_end)
+			return XDP_DROP;
+
+		if (iph->ttl <= 1)
+			return XDP_PASS;
+
+		fib_params.family	= AF_INET;
+		fib_params.tos		= iph->tos;
+		fib_params.l4_protocol	= iph->protocol;
+		fib_params.sport	= 0;
+		fib_params.dport	= 0;
+		fib_params.tot_len	= ntohs(iph->tot_len);
+		fib_params.ipv4_src	= iph->saddr;
+		fib_params.ipv4_dst	= iph->daddr;
+	} else if (h_proto == htons(ETH_P_IPV6)) {
+		struct in6_addr *src = (struct in6_addr *) fib_params.ipv6_src;
+		struct in6_addr *dst = (struct in6_addr *) fib_params.ipv6_dst;
+
+		ip6h = data + nh_off;
+		if (ip6h + 1 > data_end)
+			return XDP_DROP;
+
+		if (ip6h->hop_limit <= 1)
+			return XDP_PASS;
+
+		fib_params.family	= AF_INET6;
+		fib_params.flowinfo	= *(__be32 *)ip6h & IPV6_FLOWINFO_MASK;
+		fib_params.l4_protocol	= ip6h->nexthdr;
+		fib_params.sport	= 0;
+		fib_params.dport	= 0;
+		fib_params.tot_len	= ntohs(ip6h->payload_len);
+		*src			= ip6h->saddr;
+		*dst			= ip6h->daddr;
+	} else {
+		return XDP_PASS;
+	}
+
+	fib_params.ifindex = ctx->ingress_ifindex;
+
+	rc = bpf_fib_lookup(ctx, &fib_params, sizeof(fib_params), flags);
+	/*
+	 * Some rc (return codes) from bpf_fib_lookup() are important,
+	 * to understand how this XDP-prog interacts with network stack.
+	 *
+	 * BPF_FIB_LKUP_RET_NO_NEIGH:
+	 *  Even if route lookup was a success, then the MAC-addresses are also
+	 *  needed.  This is obtained from arp/neighbour table, but if table is
+	 *  (still) empty then BPF_FIB_LKUP_RET_NO_NEIGH is returned.  To avoid
+	 *  doing ARP lookup directly from XDP, then send packet to normal
+	 *  network stack via XDP_PASS and expect it will do ARP resolution.
+	 *
+	 * BPF_FIB_LKUP_RET_FWD_DISABLED:
+	 *  The bpf_fib_lookup respect sysctl net.ipv{4,6}.conf.all.forwarding
+	 *  setting, and will return BPF_FIB_LKUP_RET_FWD_DISABLED if not
+	 *  enabled this on ingress device.
+	 */
+	if (rc == BPF_FIB_LKUP_RET_SUCCESS) {
+		/* Verify egress index has been configured as TX-port.
+		 * (Note: User can still have inserted an egress ifindex that
+		 * doesn't support XDP xmit, which will result in packet drops).
+		 *
+		 * Note: lookup in devmap supported since 0cdbb4b09a0.
+		 * If not supported will fail with:
+		 *  cannot pass map_type 14 into func bpf_map_lookup_elem#1:
+		 */
+		if (!bpf_map_lookup_elem(&xdp_tx_ports, &fib_params.ifindex))
+			return XDP_PASS;
+
+		if (h_proto == htons(ETH_P_IP))
+			ip_decrease_ttl(iph);
+		else if (h_proto == htons(ETH_P_IPV6))
+			ip6h->hop_limit--;
+
+		memcpy(eth->h_dest, fib_params.dmac, ETH_ALEN);
+		memcpy(eth->h_source, fib_params.smac, ETH_ALEN);
+		return bpf_redirect_map(&xdp_tx_ports, fib_params.ifindex, 0);
+	}
+
+	return XDP_PASS;
+}
+
+SEC("xdp_fwd")
+int xdp_fwd_prog(struct xdp_md *ctx)
+{
+	return xdp_fwd_flags(ctx, 0);
+}
+
+SEC("xdp_fwd_direct")
+int xdp_fwd_direct_prog(struct xdp_md *ctx)
+{
+	return xdp_fwd_flags(ctx, BPF_FIB_LOOKUP_DIRECT);
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c
new file mode 100644
index 000000000..74a4583d0
--- /dev/null
+++ b/samples/bpf/xdp_fwd_user.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2017-18 David Ahern <dsahern@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/bpf.h>
+#include <linux/if_link.h>
+#include <linux/limits.h>
+#include <net/if.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <libgen.h>
+
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+
+static int do_attach(int idx, int prog_fd, int map_fd, const char *name)
+{
+	int err;
+
+	err = bpf_set_link_xdp_fd(idx, prog_fd, xdp_flags);
+	if (err < 0) {
+		printf("ERROR: failed to attach program to %s\n", name);
+		return err;
+	}
+
+	/* Adding ifindex as a possible egress TX port */
+	err = bpf_map_update_elem(map_fd, &idx, &idx, 0);
+	if (err)
+		printf("ERROR: failed using device %s as TX-port\n", name);
+
+	return err;
+}
+
+static int do_detach(int idx, const char *name)
+{
+	int err;
+
+	err = bpf_set_link_xdp_fd(idx, -1, xdp_flags);
+	if (err < 0)
+		printf("ERROR: failed to detach program from %s\n", name);
+
+	/* TODO: Remember to cleanup map, when adding use of shared map
+	 *  bpf_map_delete_elem((map_fd, &idx);
+	 */
+	return err;
+}
+
+static void usage(const char *prog)
+{
+	fprintf(stderr,
+		"usage: %s [OPTS] interface-list\n"
+		"\nOPTS:\n"
+		"    -d    detach program\n"
+		"    -D    direct table lookups (skip fib rules)\n",
+		prog);
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type	= BPF_PROG_TYPE_XDP,
+	};
+	const char *prog_name = "xdp_fwd";
+	struct bpf_program *prog;
+	int prog_fd, map_fd = -1;
+	char filename[PATH_MAX];
+	struct bpf_object *obj;
+	int opt, i, idx, err;
+	int attach = 1;
+	int ret = 0;
+
+	while ((opt = getopt(argc, argv, ":dDSF")) != -1) {
+		switch (opt) {
+		case 'd':
+			attach = 0;
+			break;
+		case 'S':
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
+			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		case 'D':
+			prog_name = "xdp_fwd_direct";
+			break;
+		default:
+			usage(basename(argv[0]));
+			return 1;
+		}
+	}
+
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	if (optind == argc) {
+		usage(basename(argv[0]));
+		return 1;
+	}
+
+	if (attach) {
+		snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+		prog_load_attr.file = filename;
+
+		if (access(filename, O_RDONLY) < 0) {
+			printf("error accessing file %s: %s\n",
+				filename, strerror(errno));
+			return 1;
+		}
+
+		err = bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd);
+		if (err) {
+			printf("Does kernel support devmap lookup?\n");
+			/* If not, the error message will be:
+			 *  "cannot pass map_type 14 into func bpf_map_lookup_elem#1"
+			 */
+			return 1;
+		}
+
+		prog = bpf_object__find_program_by_title(obj, prog_name);
+		prog_fd = bpf_program__fd(prog);
+		if (prog_fd < 0) {
+			printf("program not found: %s\n", strerror(prog_fd));
+			return 1;
+		}
+		map_fd = bpf_map__fd(bpf_object__find_map_by_name(obj,
+							"xdp_tx_ports"));
+		if (map_fd < 0) {
+			printf("map not found: %s\n", strerror(map_fd));
+			return 1;
+		}
+	}
+
+	for (i = optind; i < argc; ++i) {
+		idx = if_nametoindex(argv[i]);
+		if (!idx)
+			idx = strtoul(argv[i], NULL, 0);
+
+		if (!idx) {
+			fprintf(stderr, "Invalid arg\n");
+			return 1;
+		}
+		if (!attach) {
+			err = do_detach(idx, argv[i]);
+			if (err)
+				ret = err;
+		} else {
+			err = do_attach(idx, prog_fd, map_fd, argv[i]);
+			if (err)
+				ret = err;
+		}
+	}
+
+	return ret;
+}
diff --git a/samples/bpf/xdp_monitor_kern.c b/samples/bpf/xdp_monitor_kern.c
new file mode 100644
index 000000000..5c955b812
--- /dev/null
+++ b/samples/bpf/xdp_monitor_kern.c
@@ -0,0 +1,257 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *  Copyright(c) 2017-2018 Jesper Dangaard Brouer, Red Hat Inc.
+ *
+ * XDP monitor tool, based on tracepoints
+ */
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, u64);
+	__uint(max_entries, 2);
+	/* TODO: have entries for all possible errno's */
+} redirect_err_cnt SEC(".maps");
+
+#define XDP_UNKNOWN	XDP_REDIRECT + 1
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, u64);
+	__uint(max_entries, XDP_UNKNOWN + 1);
+} exception_cnt SEC(".maps");
+
+/* Tracepoint format: /sys/kernel/debug/tracing/events/xdp/xdp_redirect/format
+ * Code in:                kernel/include/trace/events/xdp.h
+ */
+struct xdp_redirect_ctx {
+	u64 __pad;		// First 8 bytes are not accessible by bpf code
+	int prog_id;		//	offset:8;  size:4; signed:1;
+	u32 act;		//	offset:12  size:4; signed:0;
+	int ifindex;		//	offset:16  size:4; signed:1;
+	int err;		//	offset:20  size:4; signed:1;
+	int to_ifindex;		//	offset:24  size:4; signed:1;
+	u32 map_id;		//	offset:28  size:4; signed:0;
+	int map_index;		//	offset:32  size:4; signed:1;
+};				//	offset:36
+
+enum {
+	XDP_REDIRECT_SUCCESS = 0,
+	XDP_REDIRECT_ERROR = 1
+};
+
+static __always_inline
+int xdp_redirect_collect_stat(struct xdp_redirect_ctx *ctx)
+{
+	u32 key = XDP_REDIRECT_ERROR;
+	int err = ctx->err;
+	u64 *cnt;
+
+	if (!err)
+		key = XDP_REDIRECT_SUCCESS;
+
+	cnt  = bpf_map_lookup_elem(&redirect_err_cnt, &key);
+	if (!cnt)
+		return 1;
+	*cnt += 1;
+
+	return 0; /* Indicate event was filtered (no further processing)*/
+	/*
+	 * Returning 1 here would allow e.g. a perf-record tracepoint
+	 * to see and record these events, but it doesn't work well
+	 * in-practice as stopping perf-record also unload this
+	 * bpf_prog.  Plus, there is additional overhead of doing so.
+	 */
+}
+
+SEC("tracepoint/xdp/xdp_redirect_err")
+int trace_xdp_redirect_err(struct xdp_redirect_ctx *ctx)
+{
+	return xdp_redirect_collect_stat(ctx);
+}
+
+
+SEC("tracepoint/xdp/xdp_redirect_map_err")
+int trace_xdp_redirect_map_err(struct xdp_redirect_ctx *ctx)
+{
+	return xdp_redirect_collect_stat(ctx);
+}
+
+/* Likely unloaded when prog starts */
+SEC("tracepoint/xdp/xdp_redirect")
+int trace_xdp_redirect(struct xdp_redirect_ctx *ctx)
+{
+	return xdp_redirect_collect_stat(ctx);
+}
+
+/* Likely unloaded when prog starts */
+SEC("tracepoint/xdp/xdp_redirect_map")
+int trace_xdp_redirect_map(struct xdp_redirect_ctx *ctx)
+{
+	return xdp_redirect_collect_stat(ctx);
+}
+
+/* Tracepoint format: /sys/kernel/debug/tracing/events/xdp/xdp_exception/format
+ * Code in:                kernel/include/trace/events/xdp.h
+ */
+struct xdp_exception_ctx {
+	u64 __pad;	// First 8 bytes are not accessible by bpf code
+	int prog_id;	//	offset:8;  size:4; signed:1;
+	u32 act;	//	offset:12; size:4; signed:0;
+	int ifindex;	//	offset:16; size:4; signed:1;
+};
+
+SEC("tracepoint/xdp/xdp_exception")
+int trace_xdp_exception(struct xdp_exception_ctx *ctx)
+{
+	u64 *cnt;
+	u32 key;
+
+	key = ctx->act;
+	if (key > XDP_REDIRECT)
+		key = XDP_UNKNOWN;
+
+	cnt = bpf_map_lookup_elem(&exception_cnt, &key);
+	if (!cnt)
+		return 1;
+	*cnt += 1;
+
+	return 0;
+}
+
+/* Common stats data record shared with _user.c */
+struct datarec {
+	u64 processed;
+	u64 dropped;
+	u64 info;
+	u64 err;
+};
+#define MAX_CPUS 64
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, struct datarec);
+	__uint(max_entries, MAX_CPUS);
+} cpumap_enqueue_cnt SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, struct datarec);
+	__uint(max_entries, 1);
+} cpumap_kthread_cnt SEC(".maps");
+
+/* Tracepoint: /sys/kernel/debug/tracing/events/xdp/xdp_cpumap_enqueue/format
+ * Code in:         kernel/include/trace/events/xdp.h
+ */
+struct cpumap_enqueue_ctx {
+	u64 __pad;		// First 8 bytes are not accessible by bpf code
+	int map_id;		//	offset:8;  size:4; signed:1;
+	u32 act;		//	offset:12; size:4; signed:0;
+	int cpu;		//	offset:16; size:4; signed:1;
+	unsigned int drops;	//	offset:20; size:4; signed:0;
+	unsigned int processed;	//	offset:24; size:4; signed:0;
+	int to_cpu;		//	offset:28; size:4; signed:1;
+};
+
+SEC("tracepoint/xdp/xdp_cpumap_enqueue")
+int trace_xdp_cpumap_enqueue(struct cpumap_enqueue_ctx *ctx)
+{
+	u32 to_cpu = ctx->to_cpu;
+	struct datarec *rec;
+
+	if (to_cpu >= MAX_CPUS)
+		return 1;
+
+	rec = bpf_map_lookup_elem(&cpumap_enqueue_cnt, &to_cpu);
+	if (!rec)
+		return 0;
+	rec->processed += ctx->processed;
+	rec->dropped   += ctx->drops;
+
+	/* Record bulk events, then userspace can calc average bulk size */
+	if (ctx->processed > 0)
+		rec->info += 1;
+
+	return 0;
+}
+
+/* Tracepoint: /sys/kernel/debug/tracing/events/xdp/xdp_cpumap_kthread/format
+ * Code in:         kernel/include/trace/events/xdp.h
+ */
+struct cpumap_kthread_ctx {
+	u64 __pad;		// First 8 bytes are not accessible by bpf code
+	int map_id;		//	offset:8;  size:4; signed:1;
+	u32 act;		//	offset:12; size:4; signed:0;
+	int cpu;		//	offset:16; size:4; signed:1;
+	unsigned int drops;	//	offset:20; size:4; signed:0;
+	unsigned int processed;	//	offset:24; size:4; signed:0;
+	int sched;		//	offset:28; size:4; signed:1;
+};
+
+SEC("tracepoint/xdp/xdp_cpumap_kthread")
+int trace_xdp_cpumap_kthread(struct cpumap_kthread_ctx *ctx)
+{
+	struct datarec *rec;
+	u32 key = 0;
+
+	rec = bpf_map_lookup_elem(&cpumap_kthread_cnt, &key);
+	if (!rec)
+		return 0;
+	rec->processed += ctx->processed;
+	rec->dropped   += ctx->drops;
+
+	/* Count times kthread yielded CPU via schedule call */
+	if (ctx->sched)
+		rec->info++;
+
+	return 0;
+}
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, struct datarec);
+	__uint(max_entries, 1);
+} devmap_xmit_cnt SEC(".maps");
+
+/* Tracepoint: /sys/kernel/debug/tracing/events/xdp/xdp_devmap_xmit/format
+ * Code in:         kernel/include/trace/events/xdp.h
+ */
+struct devmap_xmit_ctx {
+	u64 __pad;		// First 8 bytes are not accessible by bpf code
+	int from_ifindex;	//	offset:8;  size:4; signed:1;
+	u32 act;		//	offset:12; size:4; signed:0;
+	int to_ifindex; 	//	offset:16; size:4; signed:1;
+	int drops;		//	offset:20; size:4; signed:1;
+	int sent;		//	offset:24; size:4; signed:1;
+	int err;		//	offset:28; size:4; signed:1;
+};
+
+SEC("tracepoint/xdp/xdp_devmap_xmit")
+int trace_xdp_devmap_xmit(struct devmap_xmit_ctx *ctx)
+{
+	struct datarec *rec;
+	u32 key = 0;
+
+	rec = bpf_map_lookup_elem(&devmap_xmit_cnt, &key);
+	if (!rec)
+		return 0;
+	rec->processed += ctx->sent;
+	rec->dropped   += ctx->drops;
+
+	/* Record bulk events, then userspace can calc average bulk size */
+	rec->info += 1;
+
+	/* Record error cases, where no frame were sent */
+	if (ctx->err)
+		rec->err++;
+
+	/* Catch API error of drv ndo_xdp_xmit sent more than count */
+	if (ctx->drops < 0)
+		rec->err++;
+
+	return 1;
+}
diff --git a/samples/bpf/xdp_monitor_user.c b/samples/bpf/xdp_monitor_user.c
new file mode 100644
index 000000000..03d0a1829
--- /dev/null
+++ b/samples/bpf/xdp_monitor_user.c
@@ -0,0 +1,792 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat, Inc.
+ */
+static const char *__doc__=
+ "XDP monitor tool, based on tracepoints\n"
+;
+
+static const char *__doc_err_only__=
+ " NOTICE: Only tracking XDP redirect errors\n"
+ "         Enable TX success stats via '--stats'\n"
+ "         (which comes with a per packet processing overhead)\n"
+;
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <locale.h>
+
+#include <sys/resource.h>
+#include <getopt.h>
+#include <net/if.h>
+#include <time.h>
+
+#include <signal.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "bpf_util.h"
+
+enum map_type {
+	REDIRECT_ERR_CNT,
+	EXCEPTION_CNT,
+	CPUMAP_ENQUEUE_CNT,
+	CPUMAP_KTHREAD_CNT,
+	DEVMAP_XMIT_CNT,
+};
+
+static const char *const map_type_strings[] = {
+	[REDIRECT_ERR_CNT] = "redirect_err_cnt",
+	[EXCEPTION_CNT] = "exception_cnt",
+	[CPUMAP_ENQUEUE_CNT] = "cpumap_enqueue_cnt",
+	[CPUMAP_KTHREAD_CNT] = "cpumap_kthread_cnt",
+	[DEVMAP_XMIT_CNT] = "devmap_xmit_cnt",
+};
+
+#define NUM_MAP 5
+#define NUM_TP 8
+
+static int tp_cnt;
+static int map_cnt;
+static int verbose = 1;
+static bool debug = false;
+struct bpf_map *map_data[NUM_MAP] = {};
+struct bpf_link *tp_links[NUM_TP] = {};
+struct bpf_object *obj;
+
+static const struct option long_options[] = {
+	{"help",	no_argument,		NULL, 'h' },
+	{"debug",	no_argument,		NULL, 'D' },
+	{"stats",	no_argument,		NULL, 'S' },
+	{"sec", 	required_argument,	NULL, 's' },
+	{0, 0, NULL,  0 }
+};
+
+static void int_exit(int sig)
+{
+	/* Detach tracepoints */
+	while (tp_cnt)
+		bpf_link__destroy(tp_links[--tp_cnt]);
+
+	bpf_object__close(obj);
+	exit(0);
+}
+
+/* C standard specifies two constants, EXIT_SUCCESS(0) and EXIT_FAILURE(1) */
+#define EXIT_FAIL_MEM	5
+
+static void usage(char *argv[])
+{
+	int i;
+	printf("\nDOCUMENTATION:\n%s\n", __doc__);
+	printf("\n");
+	printf(" Usage: %s (options-see-below)\n",
+	       argv[0]);
+	printf(" Listing options:\n");
+	for (i = 0; long_options[i].name != 0; i++) {
+		printf(" --%-15s", long_options[i].name);
+		if (long_options[i].flag != NULL)
+			printf(" flag (internal value:%d)",
+			       *long_options[i].flag);
+		else
+			printf("short-option: -%c",
+			       long_options[i].val);
+		printf("\n");
+	}
+	printf("\n");
+}
+
+#define NANOSEC_PER_SEC 1000000000 /* 10^9 */
+static __u64 gettime(void)
+{
+	struct timespec t;
+	int res;
+
+	res = clock_gettime(CLOCK_MONOTONIC, &t);
+	if (res < 0) {
+		fprintf(stderr, "Error with gettimeofday! (%i)\n", res);
+		exit(EXIT_FAILURE);
+	}
+	return (__u64) t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec;
+}
+
+enum {
+	REDIR_SUCCESS = 0,
+	REDIR_ERROR = 1,
+};
+#define REDIR_RES_MAX 2
+static const char *redir_names[REDIR_RES_MAX] = {
+	[REDIR_SUCCESS]	= "Success",
+	[REDIR_ERROR]	= "Error",
+};
+static const char *err2str(int err)
+{
+	if (err < REDIR_RES_MAX)
+		return redir_names[err];
+	return NULL;
+}
+/* enum xdp_action */
+#define XDP_UNKNOWN	XDP_REDIRECT + 1
+#define XDP_ACTION_MAX (XDP_UNKNOWN + 1)
+static const char *xdp_action_names[XDP_ACTION_MAX] = {
+	[XDP_ABORTED]	= "XDP_ABORTED",
+	[XDP_DROP]	= "XDP_DROP",
+	[XDP_PASS]	= "XDP_PASS",
+	[XDP_TX]	= "XDP_TX",
+	[XDP_REDIRECT]	= "XDP_REDIRECT",
+	[XDP_UNKNOWN]	= "XDP_UNKNOWN",
+};
+static const char *action2str(int action)
+{
+	if (action < XDP_ACTION_MAX)
+		return xdp_action_names[action];
+	return NULL;
+}
+
+/* Common stats data record shared with _kern.c */
+struct datarec {
+	__u64 processed;
+	__u64 dropped;
+	__u64 info;
+	__u64 err;
+};
+#define MAX_CPUS 64
+
+/* Userspace structs for collection of stats from maps */
+struct record {
+	__u64 timestamp;
+	struct datarec total;
+	struct datarec *cpu;
+};
+struct u64rec {
+	__u64 processed;
+};
+struct record_u64 {
+	/* record for _kern side __u64 values */
+	__u64 timestamp;
+	struct u64rec total;
+	struct u64rec *cpu;
+};
+
+struct stats_record {
+	struct record_u64 xdp_redirect[REDIR_RES_MAX];
+	struct record_u64 xdp_exception[XDP_ACTION_MAX];
+	struct record xdp_cpumap_kthread;
+	struct record xdp_cpumap_enqueue[MAX_CPUS];
+	struct record xdp_devmap_xmit;
+};
+
+static bool map_collect_record(int fd, __u32 key, struct record *rec)
+{
+	/* For percpu maps, userspace gets a value per possible CPU */
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	struct datarec values[nr_cpus];
+	__u64 sum_processed = 0;
+	__u64 sum_dropped = 0;
+	__u64 sum_info = 0;
+	__u64 sum_err = 0;
+	int i;
+
+	if ((bpf_map_lookup_elem(fd, &key, values)) != 0) {
+		fprintf(stderr,
+			"ERR: bpf_map_lookup_elem failed key:0x%X\n", key);
+		return false;
+	}
+	/* Get time as close as possible to reading map contents */
+	rec->timestamp = gettime();
+
+	/* Record and sum values from each CPU */
+	for (i = 0; i < nr_cpus; i++) {
+		rec->cpu[i].processed = values[i].processed;
+		sum_processed        += values[i].processed;
+		rec->cpu[i].dropped = values[i].dropped;
+		sum_dropped        += values[i].dropped;
+		rec->cpu[i].info = values[i].info;
+		sum_info        += values[i].info;
+		rec->cpu[i].err = values[i].err;
+		sum_err        += values[i].err;
+	}
+	rec->total.processed = sum_processed;
+	rec->total.dropped   = sum_dropped;
+	rec->total.info      = sum_info;
+	rec->total.err       = sum_err;
+	return true;
+}
+
+static bool map_collect_record_u64(int fd, __u32 key, struct record_u64 *rec)
+{
+	/* For percpu maps, userspace gets a value per possible CPU */
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	struct u64rec values[nr_cpus];
+	__u64 sum_total = 0;
+	int i;
+
+	if ((bpf_map_lookup_elem(fd, &key, values)) != 0) {
+		fprintf(stderr,
+			"ERR: bpf_map_lookup_elem failed key:0x%X\n", key);
+		return false;
+	}
+	/* Get time as close as possible to reading map contents */
+	rec->timestamp = gettime();
+
+	/* Record and sum values from each CPU */
+	for (i = 0; i < nr_cpus; i++) {
+		rec->cpu[i].processed = values[i].processed;
+		sum_total            += values[i].processed;
+	}
+	rec->total.processed = sum_total;
+	return true;
+}
+
+static double calc_period(struct record *r, struct record *p)
+{
+	double period_ = 0;
+	__u64 period = 0;
+
+	period = r->timestamp - p->timestamp;
+	if (period > 0)
+		period_ = ((double) period / NANOSEC_PER_SEC);
+
+	return period_;
+}
+
+static double calc_period_u64(struct record_u64 *r, struct record_u64 *p)
+{
+	double period_ = 0;
+	__u64 period = 0;
+
+	period = r->timestamp - p->timestamp;
+	if (period > 0)
+		period_ = ((double) period / NANOSEC_PER_SEC);
+
+	return period_;
+}
+
+static double calc_pps(struct datarec *r, struct datarec *p, double period)
+{
+	__u64 packets = 0;
+	double pps = 0;
+
+	if (period > 0) {
+		packets = r->processed - p->processed;
+		pps = packets / period;
+	}
+	return pps;
+}
+
+static double calc_pps_u64(struct u64rec *r, struct u64rec *p, double period)
+{
+	__u64 packets = 0;
+	double pps = 0;
+
+	if (period > 0) {
+		packets = r->processed - p->processed;
+		pps = packets / period;
+	}
+	return pps;
+}
+
+static double calc_drop(struct datarec *r, struct datarec *p, double period)
+{
+	__u64 packets = 0;
+	double pps = 0;
+
+	if (period > 0) {
+		packets = r->dropped - p->dropped;
+		pps = packets / period;
+	}
+	return pps;
+}
+
+static double calc_info(struct datarec *r, struct datarec *p, double period)
+{
+	__u64 packets = 0;
+	double pps = 0;
+
+	if (period > 0) {
+		packets = r->info - p->info;
+		pps = packets / period;
+	}
+	return pps;
+}
+
+static double calc_err(struct datarec *r, struct datarec *p, double period)
+{
+	__u64 packets = 0;
+	double pps = 0;
+
+	if (period > 0) {
+		packets = r->err - p->err;
+		pps = packets / period;
+	}
+	return pps;
+}
+
+static void stats_print(struct stats_record *stats_rec,
+			struct stats_record *stats_prev,
+			bool err_only)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	int rec_i = 0, i, to_cpu;
+	double t = 0, pps = 0;
+
+	/* Header */
+	printf("%-15s %-7s %-12s %-12s %-9s\n",
+	       "XDP-event", "CPU:to", "pps", "drop-pps", "extra-info");
+
+	/* tracepoint: xdp:xdp_redirect_* */
+	if (err_only)
+		rec_i = REDIR_ERROR;
+
+	for (; rec_i < REDIR_RES_MAX; rec_i++) {
+		struct record_u64 *rec, *prev;
+		char *fmt1 = "%-15s %-7d %'-12.0f %'-12.0f %s\n";
+		char *fmt2 = "%-15s %-7s %'-12.0f %'-12.0f %s\n";
+
+		rec  =  &stats_rec->xdp_redirect[rec_i];
+		prev = &stats_prev->xdp_redirect[rec_i];
+		t = calc_period_u64(rec, prev);
+
+		for (i = 0; i < nr_cpus; i++) {
+			struct u64rec *r = &rec->cpu[i];
+			struct u64rec *p = &prev->cpu[i];
+
+			pps = calc_pps_u64(r, p, t);
+			if (pps > 0)
+				printf(fmt1, "XDP_REDIRECT", i,
+				       rec_i ? 0.0: pps, rec_i ? pps : 0.0,
+				       err2str(rec_i));
+		}
+		pps = calc_pps_u64(&rec->total, &prev->total, t);
+		printf(fmt2, "XDP_REDIRECT", "total",
+		       rec_i ? 0.0: pps, rec_i ? pps : 0.0, err2str(rec_i));
+	}
+
+	/* tracepoint: xdp:xdp_exception */
+	for (rec_i = 0; rec_i < XDP_ACTION_MAX; rec_i++) {
+		struct record_u64 *rec, *prev;
+		char *fmt1 = "%-15s %-7d %'-12.0f %'-12.0f %s\n";
+		char *fmt2 = "%-15s %-7s %'-12.0f %'-12.0f %s\n";
+
+		rec  =  &stats_rec->xdp_exception[rec_i];
+		prev = &stats_prev->xdp_exception[rec_i];
+		t = calc_period_u64(rec, prev);
+
+		for (i = 0; i < nr_cpus; i++) {
+			struct u64rec *r = &rec->cpu[i];
+			struct u64rec *p = &prev->cpu[i];
+
+			pps = calc_pps_u64(r, p, t);
+			if (pps > 0)
+				printf(fmt1, "Exception", i,
+				       0.0, pps, action2str(rec_i));
+		}
+		pps = calc_pps_u64(&rec->total, &prev->total, t);
+		if (pps > 0)
+			printf(fmt2, "Exception", "total",
+			       0.0, pps, action2str(rec_i));
+	}
+
+	/* cpumap enqueue stats */
+	for (to_cpu = 0; to_cpu < MAX_CPUS; to_cpu++) {
+		char *fmt1 = "%-15s %3d:%-3d %'-12.0f %'-12.0f %'-10.2f %s\n";
+		char *fmt2 = "%-15s %3s:%-3d %'-12.0f %'-12.0f %'-10.2f %s\n";
+		struct record *rec, *prev;
+		char *info_str = "";
+		double drop, info;
+
+		rec  =  &stats_rec->xdp_cpumap_enqueue[to_cpu];
+		prev = &stats_prev->xdp_cpumap_enqueue[to_cpu];
+		t = calc_period(rec, prev);
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+
+			pps  = calc_pps(r, p, t);
+			drop = calc_drop(r, p, t);
+			info = calc_info(r, p, t);
+			if (info > 0) {
+				info_str = "bulk-average";
+				info = pps / info; /* calc average bulk size */
+			}
+			if (pps > 0)
+				printf(fmt1, "cpumap-enqueue",
+				       i, to_cpu, pps, drop, info, info_str);
+		}
+		pps = calc_pps(&rec->total, &prev->total, t);
+		if (pps > 0) {
+			drop = calc_drop(&rec->total, &prev->total, t);
+			info = calc_info(&rec->total, &prev->total, t);
+			if (info > 0) {
+				info_str = "bulk-average";
+				info = pps / info; /* calc average bulk size */
+			}
+			printf(fmt2, "cpumap-enqueue",
+			       "sum", to_cpu, pps, drop, info, info_str);
+		}
+	}
+
+	/* cpumap kthread stats */
+	{
+		char *fmt1 = "%-15s %-7d %'-12.0f %'-12.0f %'-10.0f %s\n";
+		char *fmt2 = "%-15s %-7s %'-12.0f %'-12.0f %'-10.0f %s\n";
+		struct record *rec, *prev;
+		double drop, info;
+		char *i_str = "";
+
+		rec  =  &stats_rec->xdp_cpumap_kthread;
+		prev = &stats_prev->xdp_cpumap_kthread;
+		t = calc_period(rec, prev);
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+
+			pps  = calc_pps(r, p, t);
+			drop = calc_drop(r, p, t);
+			info = calc_info(r, p, t);
+			if (info > 0)
+				i_str = "sched";
+			if (pps > 0 || drop > 0)
+				printf(fmt1, "cpumap-kthread",
+				       i, pps, drop, info, i_str);
+		}
+		pps = calc_pps(&rec->total, &prev->total, t);
+		drop = calc_drop(&rec->total, &prev->total, t);
+		info = calc_info(&rec->total, &prev->total, t);
+		if (info > 0)
+			i_str = "sched-sum";
+		printf(fmt2, "cpumap-kthread", "total", pps, drop, info, i_str);
+	}
+
+	/* devmap ndo_xdp_xmit stats */
+	{
+		char *fmt1 = "%-15s %-7d %'-12.0f %'-12.0f %'-10.2f %s %s\n";
+		char *fmt2 = "%-15s %-7s %'-12.0f %'-12.0f %'-10.2f %s %s\n";
+		struct record *rec, *prev;
+		double drop, info, err;
+		char *i_str = "";
+		char *err_str = "";
+
+		rec  =  &stats_rec->xdp_devmap_xmit;
+		prev = &stats_prev->xdp_devmap_xmit;
+		t = calc_period(rec, prev);
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+
+			pps  = calc_pps(r, p, t);
+			drop = calc_drop(r, p, t);
+			info = calc_info(r, p, t);
+			err  = calc_err(r, p, t);
+			if (info > 0) {
+				i_str = "bulk-average";
+				info = (pps+drop) / info; /* calc avg bulk */
+			}
+			if (err > 0)
+				err_str = "drv-err";
+			if (pps > 0 || drop > 0)
+				printf(fmt1, "devmap-xmit",
+				       i, pps, drop, info, i_str, err_str);
+		}
+		pps = calc_pps(&rec->total, &prev->total, t);
+		drop = calc_drop(&rec->total, &prev->total, t);
+		info = calc_info(&rec->total, &prev->total, t);
+		err  = calc_err(&rec->total, &prev->total, t);
+		if (info > 0) {
+			i_str = "bulk-average";
+			info = (pps+drop) / info; /* calc avg bulk */
+		}
+		if (err > 0)
+			err_str = "drv-err";
+		printf(fmt2, "devmap-xmit", "total", pps, drop,
+		       info, i_str, err_str);
+	}
+
+	printf("\n");
+}
+
+static bool stats_collect(struct stats_record *rec)
+{
+	int fd;
+	int i;
+
+	/* TODO: Detect if someone unloaded the perf event_fd's, as
+	 * this can happen by someone running perf-record -e
+	 */
+
+	fd = bpf_map__fd(map_data[REDIRECT_ERR_CNT]);
+	for (i = 0; i < REDIR_RES_MAX; i++)
+		map_collect_record_u64(fd, i, &rec->xdp_redirect[i]);
+
+	fd = bpf_map__fd(map_data[EXCEPTION_CNT]);
+	for (i = 0; i < XDP_ACTION_MAX; i++) {
+		map_collect_record_u64(fd, i, &rec->xdp_exception[i]);
+	}
+
+	fd = bpf_map__fd(map_data[CPUMAP_ENQUEUE_CNT]);
+	for (i = 0; i < MAX_CPUS; i++)
+		map_collect_record(fd, i, &rec->xdp_cpumap_enqueue[i]);
+
+	fd = bpf_map__fd(map_data[CPUMAP_KTHREAD_CNT]);
+	map_collect_record(fd, 0, &rec->xdp_cpumap_kthread);
+
+	fd = bpf_map__fd(map_data[DEVMAP_XMIT_CNT]);
+	map_collect_record(fd, 0, &rec->xdp_devmap_xmit);
+
+	return true;
+}
+
+static void *alloc_rec_per_cpu(int record_size)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	void *array;
+
+	array = calloc(nr_cpus, record_size);
+	if (!array) {
+		fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus);
+		exit(EXIT_FAIL_MEM);
+	}
+	return array;
+}
+
+static struct stats_record *alloc_stats_record(void)
+{
+	struct stats_record *rec;
+	int rec_sz;
+	int i;
+
+	/* Alloc main stats_record structure */
+	rec = calloc(1, sizeof(*rec));
+	if (!rec) {
+		fprintf(stderr, "Mem alloc error\n");
+		exit(EXIT_FAIL_MEM);
+	}
+
+	/* Alloc stats stored per CPU for each record */
+	rec_sz = sizeof(struct u64rec);
+	for (i = 0; i < REDIR_RES_MAX; i++)
+		rec->xdp_redirect[i].cpu = alloc_rec_per_cpu(rec_sz);
+
+	for (i = 0; i < XDP_ACTION_MAX; i++)
+		rec->xdp_exception[i].cpu = alloc_rec_per_cpu(rec_sz);
+
+	rec_sz = sizeof(struct datarec);
+	rec->xdp_cpumap_kthread.cpu = alloc_rec_per_cpu(rec_sz);
+	rec->xdp_devmap_xmit.cpu    = alloc_rec_per_cpu(rec_sz);
+
+	for (i = 0; i < MAX_CPUS; i++)
+		rec->xdp_cpumap_enqueue[i].cpu = alloc_rec_per_cpu(rec_sz);
+
+	return rec;
+}
+
+static void free_stats_record(struct stats_record *r)
+{
+	int i;
+
+	for (i = 0; i < REDIR_RES_MAX; i++)
+		free(r->xdp_redirect[i].cpu);
+
+	for (i = 0; i < XDP_ACTION_MAX; i++)
+		free(r->xdp_exception[i].cpu);
+
+	free(r->xdp_cpumap_kthread.cpu);
+	free(r->xdp_devmap_xmit.cpu);
+
+	for (i = 0; i < MAX_CPUS; i++)
+		free(r->xdp_cpumap_enqueue[i].cpu);
+
+	free(r);
+}
+
+/* Pointer swap trick */
+static inline void swap(struct stats_record **a, struct stats_record **b)
+{
+	struct stats_record *tmp;
+
+	tmp = *a;
+	*a = *b;
+	*b = tmp;
+}
+
+static void stats_poll(int interval, bool err_only)
+{
+	struct stats_record *rec, *prev;
+
+	rec  = alloc_stats_record();
+	prev = alloc_stats_record();
+	stats_collect(rec);
+
+	if (err_only)
+		printf("\n%s\n", __doc_err_only__);
+
+	/* Trick to pretty printf with thousands separators use %' */
+	setlocale(LC_NUMERIC, "en_US");
+
+	/* Header */
+	if (verbose)
+		printf("\n%s", __doc__);
+
+	/* TODO Need more advanced stats on error types */
+	if (verbose) {
+		printf(" - Stats map0: %s\n", bpf_map__name(map_data[0]));
+		printf(" - Stats map1: %s\n", bpf_map__name(map_data[1]));
+		printf("\n");
+	}
+	fflush(stdout);
+
+	while (1) {
+		swap(&prev, &rec);
+		stats_collect(rec);
+		stats_print(rec, prev, err_only);
+		fflush(stdout);
+		sleep(interval);
+	}
+
+	free_stats_record(rec);
+	free_stats_record(prev);
+}
+
+static void print_bpf_prog_info(void)
+{
+	struct bpf_program *prog;
+	struct bpf_map *map;
+	int i = 0;
+
+	/* Prog info */
+	printf("Loaded BPF prog have %d bpf program(s)\n", tp_cnt);
+	bpf_object__for_each_program(prog, obj) {
+		printf(" - prog_fd[%d] = fd(%d)\n", i, bpf_program__fd(prog));
+		i++;
+	}
+
+	i = 0;
+	/* Maps info */
+	printf("Loaded BPF prog have %d map(s)\n", map_cnt);
+	bpf_object__for_each_map(map, obj) {
+		const char *name = bpf_map__name(map);
+		int fd		 = bpf_map__fd(map);
+
+		printf(" - map_data[%d] = fd(%d) name:%s\n", i, fd, name);
+		i++;
+	}
+
+	/* Event info */
+	printf("Searching for (max:%d) event file descriptor(s)\n", tp_cnt);
+	for (i = 0; i < tp_cnt; i++) {
+		int fd = bpf_link__fd(tp_links[i]);
+
+		if (fd != -1)
+			printf(" - event_fd[%d] = fd(%d)\n", i, fd);
+	}
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_program *prog;
+	int longindex = 0, opt;
+	int ret = EXIT_FAILURE;
+	enum map_type type;
+	char filename[256];
+
+	/* Default settings: */
+	bool errors_only = true;
+	int interval = 2;
+
+	/* Parse commands line args */
+	while ((opt = getopt_long(argc, argv, "hDSs:",
+				  long_options, &longindex)) != -1) {
+		switch (opt) {
+		case 'D':
+			debug = true;
+			break;
+		case 'S':
+			errors_only = false;
+			break;
+		case 's':
+			interval = atoi(optarg);
+			break;
+		case 'h':
+		default:
+			usage(argv);
+			return ret;
+		}
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return ret;
+	}
+
+	/* Remove tracepoint program when program is interrupted or killed */
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		printf("ERROR: opening BPF object file failed\n");
+		obj = NULL;
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		printf("ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	for (type = 0; type < NUM_MAP; type++) {
+		map_data[type] =
+			bpf_object__find_map_by_name(obj, map_type_strings[type]);
+
+		if (libbpf_get_error(map_data[type])) {
+			printf("ERROR: finding a map in obj file failed\n");
+			goto cleanup;
+		}
+		map_cnt++;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		tp_links[tp_cnt] = bpf_program__attach(prog);
+		if (libbpf_get_error(tp_links[tp_cnt])) {
+			printf("ERROR: bpf_program__attach failed\n");
+			tp_links[tp_cnt] = NULL;
+			goto cleanup;
+		}
+		tp_cnt++;
+	}
+
+	if (debug) {
+		print_bpf_prog_info();
+	}
+
+	/* Unload/stop tracepoint event by closing bpf_link's */
+	if (errors_only) {
+		/* The bpf_link[i] depend on the order of
+		 * the functions was defined in _kern.c
+		 */
+		bpf_link__destroy(tp_links[2]);	/* tracepoint/xdp/xdp_redirect */
+		tp_links[2] = NULL;
+
+		bpf_link__destroy(tp_links[3]);	/* tracepoint/xdp/xdp_redirect_map */
+		tp_links[3] = NULL;
+	}
+
+	stats_poll(interval, errors_only);
+
+	ret = EXIT_SUCCESS;
+
+cleanup:
+	/* Detach tracepoints */
+	while (tp_cnt)
+		bpf_link__destroy(tp_links[--tp_cnt]);
+
+	bpf_object__close(obj);
+	return ret;
+}
diff --git a/samples/bpf/xdp_redirect_cpu_kern.c b/samples/bpf/xdp_redirect_cpu_kern.c
new file mode 100644
index 000000000..8255025de
--- /dev/null
+++ b/samples/bpf/xdp_redirect_cpu_kern.c
@@ -0,0 +1,730 @@
+/*  XDP redirect to CPUs via cpumap (BPF_MAP_TYPE_CPUMAP)
+ *
+ *  GPLv2, Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat, Inc.
+ */
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/if_vlan.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/udp.h>
+
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "hash_func01.h"
+
+#define MAX_CPUS NR_CPUS
+
+/* Special map type that can XDP_REDIRECT frames to another CPU */
+struct {
+	__uint(type, BPF_MAP_TYPE_CPUMAP);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, sizeof(struct bpf_cpumap_val));
+	__uint(max_entries, MAX_CPUS);
+} cpu_map SEC(".maps");
+
+/* Common stats data record to keep userspace more simple */
+struct datarec {
+	__u64 processed;
+	__u64 dropped;
+	__u64 issue;
+	__u64 xdp_pass;
+	__u64 xdp_drop;
+	__u64 xdp_redirect;
+};
+
+/* Count RX packets, as XDP bpf_prog doesn't get direct TX-success
+ * feedback.  Redirect TX errors can be caught via a tracepoint.
+ */
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, struct datarec);
+	__uint(max_entries, 1);
+} rx_cnt SEC(".maps");
+
+/* Used by trace point */
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, struct datarec);
+	__uint(max_entries, 2);
+	/* TODO: have entries for all possible errno's */
+} redirect_err_cnt SEC(".maps");
+
+/* Used by trace point */
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, struct datarec);
+	__uint(max_entries, MAX_CPUS);
+} cpumap_enqueue_cnt SEC(".maps");
+
+/* Used by trace point */
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, struct datarec);
+	__uint(max_entries, 1);
+} cpumap_kthread_cnt SEC(".maps");
+
+/* Set of maps controlling available CPU, and for iterating through
+ * selectable redirect CPUs.
+ */
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u32);
+	__uint(max_entries, MAX_CPUS);
+} cpus_available SEC(".maps");
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u32);
+	__uint(max_entries, 1);
+} cpus_count SEC(".maps");
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, u32);
+	__uint(max_entries, 1);
+} cpus_iterator SEC(".maps");
+
+/* Used by trace point */
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, struct datarec);
+	__uint(max_entries, 1);
+} exception_cnt SEC(".maps");
+
+/* Helper parse functions */
+
+/* Parse Ethernet layer 2, extract network layer 3 offset and protocol
+ *
+ * Returns false on error and non-supported ether-type
+ */
+struct vlan_hdr {
+	__be16 h_vlan_TCI;
+	__be16 h_vlan_encapsulated_proto;
+};
+
+static __always_inline
+bool parse_eth(struct ethhdr *eth, void *data_end,
+	       u16 *eth_proto, u64 *l3_offset)
+{
+	u16 eth_type;
+	u64 offset;
+
+	offset = sizeof(*eth);
+	if ((void *)eth + offset > data_end)
+		return false;
+
+	eth_type = eth->h_proto;
+
+	/* Skip non 802.3 Ethertypes */
+	if (unlikely(ntohs(eth_type) < ETH_P_802_3_MIN))
+		return false;
+
+	/* Handle VLAN tagged packet */
+	if (eth_type == htons(ETH_P_8021Q) || eth_type == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vlan_hdr;
+
+		vlan_hdr = (void *)eth + offset;
+		offset += sizeof(*vlan_hdr);
+		if ((void *)eth + offset > data_end)
+			return false;
+		eth_type = vlan_hdr->h_vlan_encapsulated_proto;
+	}
+	/* Handle double VLAN tagged packet */
+	if (eth_type == htons(ETH_P_8021Q) || eth_type == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vlan_hdr;
+
+		vlan_hdr = (void *)eth + offset;
+		offset += sizeof(*vlan_hdr);
+		if ((void *)eth + offset > data_end)
+			return false;
+		eth_type = vlan_hdr->h_vlan_encapsulated_proto;
+	}
+
+	*eth_proto = ntohs(eth_type);
+	*l3_offset = offset;
+	return true;
+}
+
+static __always_inline
+u16 get_dest_port_ipv4_udp(struct xdp_md *ctx, u64 nh_off)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data     = (void *)(long)ctx->data;
+	struct iphdr *iph = data + nh_off;
+	struct udphdr *udph;
+	u16 dport;
+
+	if (iph + 1 > data_end)
+		return 0;
+	if (!(iph->protocol == IPPROTO_UDP))
+		return 0;
+
+	udph = (void *)(iph + 1);
+	if (udph + 1 > data_end)
+		return 0;
+
+	dport = ntohs(udph->dest);
+	return dport;
+}
+
+static __always_inline
+int get_proto_ipv4(struct xdp_md *ctx, u64 nh_off)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data     = (void *)(long)ctx->data;
+	struct iphdr *iph = data + nh_off;
+
+	if (iph + 1 > data_end)
+		return 0;
+	return iph->protocol;
+}
+
+static __always_inline
+int get_proto_ipv6(struct xdp_md *ctx, u64 nh_off)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data     = (void *)(long)ctx->data;
+	struct ipv6hdr *ip6h = data + nh_off;
+
+	if (ip6h + 1 > data_end)
+		return 0;
+	return ip6h->nexthdr;
+}
+
+SEC("xdp_cpu_map0")
+int  xdp_prognum0_no_touch(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data     = (void *)(long)ctx->data;
+	struct datarec *rec;
+	u32 *cpu_selected;
+	u32 cpu_dest;
+	u32 key = 0;
+
+	/* Only use first entry in cpus_available */
+	cpu_selected = bpf_map_lookup_elem(&cpus_available, &key);
+	if (!cpu_selected)
+		return XDP_ABORTED;
+	cpu_dest = *cpu_selected;
+
+	/* Count RX packet in map */
+	rec = bpf_map_lookup_elem(&rx_cnt, &key);
+	if (!rec)
+		return XDP_ABORTED;
+	rec->processed++;
+
+	if (cpu_dest >= MAX_CPUS) {
+		rec->issue++;
+		return XDP_ABORTED;
+	}
+
+	return bpf_redirect_map(&cpu_map, cpu_dest, 0);
+}
+
+SEC("xdp_cpu_map1_touch_data")
+int  xdp_prognum1_touch_data(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data     = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	struct datarec *rec;
+	u32 *cpu_selected;
+	u32 cpu_dest;
+	u16 eth_type;
+	u32 key = 0;
+
+	/* Only use first entry in cpus_available */
+	cpu_selected = bpf_map_lookup_elem(&cpus_available, &key);
+	if (!cpu_selected)
+		return XDP_ABORTED;
+	cpu_dest = *cpu_selected;
+
+	/* Validate packet length is minimum Eth header size */
+	if (eth + 1 > data_end)
+		return XDP_ABORTED;
+
+	/* Count RX packet in map */
+	rec = bpf_map_lookup_elem(&rx_cnt, &key);
+	if (!rec)
+		return XDP_ABORTED;
+	rec->processed++;
+
+	/* Read packet data, and use it (drop non 802.3 Ethertypes) */
+	eth_type = eth->h_proto;
+	if (ntohs(eth_type) < ETH_P_802_3_MIN) {
+		rec->dropped++;
+		return XDP_DROP;
+	}
+
+	if (cpu_dest >= MAX_CPUS) {
+		rec->issue++;
+		return XDP_ABORTED;
+	}
+
+	return bpf_redirect_map(&cpu_map, cpu_dest, 0);
+}
+
+SEC("xdp_cpu_map2_round_robin")
+int  xdp_prognum2_round_robin(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data     = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	struct datarec *rec;
+	u32 cpu_dest;
+	u32 *cpu_lookup;
+	u32 key0 = 0;
+
+	u32 *cpu_selected;
+	u32 *cpu_iterator;
+	u32 *cpu_max;
+	u32 cpu_idx;
+
+	cpu_max = bpf_map_lookup_elem(&cpus_count, &key0);
+	if (!cpu_max)
+		return XDP_ABORTED;
+
+	cpu_iterator = bpf_map_lookup_elem(&cpus_iterator, &key0);
+	if (!cpu_iterator)
+		return XDP_ABORTED;
+	cpu_idx = *cpu_iterator;
+
+	*cpu_iterator += 1;
+	if (*cpu_iterator == *cpu_max)
+		*cpu_iterator = 0;
+
+	cpu_selected = bpf_map_lookup_elem(&cpus_available, &cpu_idx);
+	if (!cpu_selected)
+		return XDP_ABORTED;
+	cpu_dest = *cpu_selected;
+
+	/* Count RX packet in map */
+	rec = bpf_map_lookup_elem(&rx_cnt, &key0);
+	if (!rec)
+		return XDP_ABORTED;
+	rec->processed++;
+
+	if (cpu_dest >= MAX_CPUS) {
+		rec->issue++;
+		return XDP_ABORTED;
+	}
+
+	return bpf_redirect_map(&cpu_map, cpu_dest, 0);
+}
+
+SEC("xdp_cpu_map3_proto_separate")
+int  xdp_prognum3_proto_separate(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data     = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	u8 ip_proto = IPPROTO_UDP;
+	struct datarec *rec;
+	u16 eth_proto = 0;
+	u64 l3_offset = 0;
+	u32 cpu_dest = 0;
+	u32 cpu_idx = 0;
+	u32 *cpu_lookup;
+	u32 key = 0;
+
+	/* Count RX packet in map */
+	rec = bpf_map_lookup_elem(&rx_cnt, &key);
+	if (!rec)
+		return XDP_ABORTED;
+	rec->processed++;
+
+	if (!(parse_eth(eth, data_end, &eth_proto, &l3_offset)))
+		return XDP_PASS; /* Just skip */
+
+	/* Extract L4 protocol */
+	switch (eth_proto) {
+	case ETH_P_IP:
+		ip_proto = get_proto_ipv4(ctx, l3_offset);
+		break;
+	case ETH_P_IPV6:
+		ip_proto = get_proto_ipv6(ctx, l3_offset);
+		break;
+	case ETH_P_ARP:
+		cpu_idx = 0; /* ARP packet handled on separate CPU */
+		break;
+	default:
+		cpu_idx = 0;
+	}
+
+	/* Choose CPU based on L4 protocol */
+	switch (ip_proto) {
+	case IPPROTO_ICMP:
+	case IPPROTO_ICMPV6:
+		cpu_idx = 2;
+		break;
+	case IPPROTO_TCP:
+		cpu_idx = 0;
+		break;
+	case IPPROTO_UDP:
+		cpu_idx = 1;
+		break;
+	default:
+		cpu_idx = 0;
+	}
+
+	cpu_lookup = bpf_map_lookup_elem(&cpus_available, &cpu_idx);
+	if (!cpu_lookup)
+		return XDP_ABORTED;
+	cpu_dest = *cpu_lookup;
+
+	if (cpu_dest >= MAX_CPUS) {
+		rec->issue++;
+		return XDP_ABORTED;
+	}
+
+	return bpf_redirect_map(&cpu_map, cpu_dest, 0);
+}
+
+SEC("xdp_cpu_map4_ddos_filter_pktgen")
+int  xdp_prognum4_ddos_filter_pktgen(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data     = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	u8 ip_proto = IPPROTO_UDP;
+	struct datarec *rec;
+	u16 eth_proto = 0;
+	u64 l3_offset = 0;
+	u32 cpu_dest = 0;
+	u32 cpu_idx = 0;
+	u16 dest_port;
+	u32 *cpu_lookup;
+	u32 key = 0;
+
+	/* Count RX packet in map */
+	rec = bpf_map_lookup_elem(&rx_cnt, &key);
+	if (!rec)
+		return XDP_ABORTED;
+	rec->processed++;
+
+	if (!(parse_eth(eth, data_end, &eth_proto, &l3_offset)))
+		return XDP_PASS; /* Just skip */
+
+	/* Extract L4 protocol */
+	switch (eth_proto) {
+	case ETH_P_IP:
+		ip_proto = get_proto_ipv4(ctx, l3_offset);
+		break;
+	case ETH_P_IPV6:
+		ip_proto = get_proto_ipv6(ctx, l3_offset);
+		break;
+	case ETH_P_ARP:
+		cpu_idx = 0; /* ARP packet handled on separate CPU */
+		break;
+	default:
+		cpu_idx = 0;
+	}
+
+	/* Choose CPU based on L4 protocol */
+	switch (ip_proto) {
+	case IPPROTO_ICMP:
+	case IPPROTO_ICMPV6:
+		cpu_idx = 2;
+		break;
+	case IPPROTO_TCP:
+		cpu_idx = 0;
+		break;
+	case IPPROTO_UDP:
+		cpu_idx = 1;
+		/* DDoS filter UDP port 9 (pktgen) */
+		dest_port = get_dest_port_ipv4_udp(ctx, l3_offset);
+		if (dest_port == 9) {
+			if (rec)
+				rec->dropped++;
+			return XDP_DROP;
+		}
+		break;
+	default:
+		cpu_idx = 0;
+	}
+
+	cpu_lookup = bpf_map_lookup_elem(&cpus_available, &cpu_idx);
+	if (!cpu_lookup)
+		return XDP_ABORTED;
+	cpu_dest = *cpu_lookup;
+
+	if (cpu_dest >= MAX_CPUS) {
+		rec->issue++;
+		return XDP_ABORTED;
+	}
+
+	return bpf_redirect_map(&cpu_map, cpu_dest, 0);
+}
+
+/* Hashing initval */
+#define INITVAL 15485863
+
+static __always_inline
+u32 get_ipv4_hash_ip_pair(struct xdp_md *ctx, u64 nh_off)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data     = (void *)(long)ctx->data;
+	struct iphdr *iph = data + nh_off;
+	u32 cpu_hash;
+
+	if (iph + 1 > data_end)
+		return 0;
+
+	cpu_hash = iph->saddr + iph->daddr;
+	cpu_hash = SuperFastHash((char *)&cpu_hash, 4, INITVAL + iph->protocol);
+
+	return cpu_hash;
+}
+
+static __always_inline
+u32 get_ipv6_hash_ip_pair(struct xdp_md *ctx, u64 nh_off)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data     = (void *)(long)ctx->data;
+	struct ipv6hdr *ip6h = data + nh_off;
+	u32 cpu_hash;
+
+	if (ip6h + 1 > data_end)
+		return 0;
+
+	cpu_hash  = ip6h->saddr.s6_addr32[0] + ip6h->daddr.s6_addr32[0];
+	cpu_hash += ip6h->saddr.s6_addr32[1] + ip6h->daddr.s6_addr32[1];
+	cpu_hash += ip6h->saddr.s6_addr32[2] + ip6h->daddr.s6_addr32[2];
+	cpu_hash += ip6h->saddr.s6_addr32[3] + ip6h->daddr.s6_addr32[3];
+	cpu_hash = SuperFastHash((char *)&cpu_hash, 4, INITVAL + ip6h->nexthdr);
+
+	return cpu_hash;
+}
+
+/* Load-Balance traffic based on hashing IP-addrs + L4-proto.  The
+ * hashing scheme is symmetric, meaning swapping IP src/dest still hit
+ * same CPU.
+ */
+SEC("xdp_cpu_map5_lb_hash_ip_pairs")
+int  xdp_prognum5_lb_hash_ip_pairs(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data     = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	u8 ip_proto = IPPROTO_UDP;
+	struct datarec *rec;
+	u16 eth_proto = 0;
+	u64 l3_offset = 0;
+	u32 cpu_dest = 0;
+	u32 cpu_idx = 0;
+	u32 *cpu_lookup;
+	u32 *cpu_max;
+	u32 cpu_hash;
+	u32 key = 0;
+
+	/* Count RX packet in map */
+	rec = bpf_map_lookup_elem(&rx_cnt, &key);
+	if (!rec)
+		return XDP_ABORTED;
+	rec->processed++;
+
+	cpu_max = bpf_map_lookup_elem(&cpus_count, &key);
+	if (!cpu_max)
+		return XDP_ABORTED;
+
+	if (!(parse_eth(eth, data_end, &eth_proto, &l3_offset)))
+		return XDP_PASS; /* Just skip */
+
+	/* Hash for IPv4 and IPv6 */
+	switch (eth_proto) {
+	case ETH_P_IP:
+		cpu_hash = get_ipv4_hash_ip_pair(ctx, l3_offset);
+		break;
+	case ETH_P_IPV6:
+		cpu_hash = get_ipv6_hash_ip_pair(ctx, l3_offset);
+		break;
+	case ETH_P_ARP: /* ARP packet handled on CPU idx 0 */
+	default:
+		cpu_hash = 0;
+	}
+
+	/* Choose CPU based on hash */
+	cpu_idx = cpu_hash % *cpu_max;
+
+	cpu_lookup = bpf_map_lookup_elem(&cpus_available, &cpu_idx);
+	if (!cpu_lookup)
+		return XDP_ABORTED;
+	cpu_dest = *cpu_lookup;
+
+	if (cpu_dest >= MAX_CPUS) {
+		rec->issue++;
+		return XDP_ABORTED;
+	}
+
+	return bpf_redirect_map(&cpu_map, cpu_dest, 0);
+}
+
+char _license[] SEC("license") = "GPL";
+
+/*** Trace point code ***/
+
+/* Tracepoint format: /sys/kernel/debug/tracing/events/xdp/xdp_redirect/format
+ * Code in:                kernel/include/trace/events/xdp.h
+ */
+struct xdp_redirect_ctx {
+	u64 __pad;	// First 8 bytes are not accessible by bpf code
+	int prog_id;	//	offset:8;  size:4; signed:1;
+	u32 act;	//	offset:12  size:4; signed:0;
+	int ifindex;	//	offset:16  size:4; signed:1;
+	int err;	//	offset:20  size:4; signed:1;
+	int to_ifindex;	//	offset:24  size:4; signed:1;
+	u32 map_id;	//	offset:28  size:4; signed:0;
+	int map_index;	//	offset:32  size:4; signed:1;
+};			//	offset:36
+
+enum {
+	XDP_REDIRECT_SUCCESS = 0,
+	XDP_REDIRECT_ERROR = 1
+};
+
+static __always_inline
+int xdp_redirect_collect_stat(struct xdp_redirect_ctx *ctx)
+{
+	u32 key = XDP_REDIRECT_ERROR;
+	struct datarec *rec;
+	int err = ctx->err;
+
+	if (!err)
+		key = XDP_REDIRECT_SUCCESS;
+
+	rec = bpf_map_lookup_elem(&redirect_err_cnt, &key);
+	if (!rec)
+		return 0;
+	rec->dropped += 1;
+
+	return 0; /* Indicate event was filtered (no further processing)*/
+	/*
+	 * Returning 1 here would allow e.g. a perf-record tracepoint
+	 * to see and record these events, but it doesn't work well
+	 * in-practice as stopping perf-record also unload this
+	 * bpf_prog.  Plus, there is additional overhead of doing so.
+	 */
+}
+
+SEC("tracepoint/xdp/xdp_redirect_err")
+int trace_xdp_redirect_err(struct xdp_redirect_ctx *ctx)
+{
+	return xdp_redirect_collect_stat(ctx);
+}
+
+SEC("tracepoint/xdp/xdp_redirect_map_err")
+int trace_xdp_redirect_map_err(struct xdp_redirect_ctx *ctx)
+{
+	return xdp_redirect_collect_stat(ctx);
+}
+
+/* Tracepoint format: /sys/kernel/debug/tracing/events/xdp/xdp_exception/format
+ * Code in:                kernel/include/trace/events/xdp.h
+ */
+struct xdp_exception_ctx {
+	u64 __pad;	// First 8 bytes are not accessible by bpf code
+	int prog_id;	//	offset:8;  size:4; signed:1;
+	u32 act;	//	offset:12; size:4; signed:0;
+	int ifindex;	//	offset:16; size:4; signed:1;
+};
+
+SEC("tracepoint/xdp/xdp_exception")
+int trace_xdp_exception(struct xdp_exception_ctx *ctx)
+{
+	struct datarec *rec;
+	u32 key = 0;
+
+	rec = bpf_map_lookup_elem(&exception_cnt, &key);
+	if (!rec)
+		return 1;
+	rec->dropped += 1;
+
+	return 0;
+}
+
+/* Tracepoint: /sys/kernel/debug/tracing/events/xdp/xdp_cpumap_enqueue/format
+ * Code in:         kernel/include/trace/events/xdp.h
+ */
+struct cpumap_enqueue_ctx {
+	u64 __pad;		// First 8 bytes are not accessible by bpf code
+	int map_id;		//	offset:8;  size:4; signed:1;
+	u32 act;		//	offset:12; size:4; signed:0;
+	int cpu;		//	offset:16; size:4; signed:1;
+	unsigned int drops;	//	offset:20; size:4; signed:0;
+	unsigned int processed;	//	offset:24; size:4; signed:0;
+	int to_cpu;		//	offset:28; size:4; signed:1;
+};
+
+SEC("tracepoint/xdp/xdp_cpumap_enqueue")
+int trace_xdp_cpumap_enqueue(struct cpumap_enqueue_ctx *ctx)
+{
+	u32 to_cpu = ctx->to_cpu;
+	struct datarec *rec;
+
+	if (to_cpu >= MAX_CPUS)
+		return 1;
+
+	rec = bpf_map_lookup_elem(&cpumap_enqueue_cnt, &to_cpu);
+	if (!rec)
+		return 0;
+	rec->processed += ctx->processed;
+	rec->dropped   += ctx->drops;
+
+	/* Record bulk events, then userspace can calc average bulk size */
+	if (ctx->processed > 0)
+		rec->issue += 1;
+
+	/* Inception: It's possible to detect overload situations, via
+	 * this tracepoint.  This can be used for creating a feedback
+	 * loop to XDP, which can take appropriate actions to mitigate
+	 * this overload situation.
+	 */
+	return 0;
+}
+
+/* Tracepoint: /sys/kernel/debug/tracing/events/xdp/xdp_cpumap_kthread/format
+ * Code in:         kernel/include/trace/events/xdp.h
+ */
+struct cpumap_kthread_ctx {
+	u64 __pad;			// First 8 bytes are not accessible
+	int map_id;			//	offset:8;  size:4; signed:1;
+	u32 act;			//	offset:12; size:4; signed:0;
+	int cpu;			//	offset:16; size:4; signed:1;
+	unsigned int drops;		//	offset:20; size:4; signed:0;
+	unsigned int processed;		//	offset:24; size:4; signed:0;
+	int sched;			//	offset:28; size:4; signed:1;
+	unsigned int xdp_pass;		//	offset:32; size:4; signed:0;
+	unsigned int xdp_drop;		//	offset:36; size:4; signed:0;
+	unsigned int xdp_redirect;	//	offset:40; size:4; signed:0;
+};
+
+SEC("tracepoint/xdp/xdp_cpumap_kthread")
+int trace_xdp_cpumap_kthread(struct cpumap_kthread_ctx *ctx)
+{
+	struct datarec *rec;
+	u32 key = 0;
+
+	rec = bpf_map_lookup_elem(&cpumap_kthread_cnt, &key);
+	if (!rec)
+		return 0;
+	rec->processed += ctx->processed;
+	rec->dropped   += ctx->drops;
+	rec->xdp_pass  += ctx->xdp_pass;
+	rec->xdp_drop  += ctx->xdp_drop;
+	rec->xdp_redirect  += ctx->xdp_redirect;
+
+	/* Count times kthread yielded CPU via schedule call */
+	if (ctx->sched)
+		rec->issue++;
+
+	return 0;
+}
diff --git a/samples/bpf/xdp_redirect_cpu_user.c b/samples/bpf/xdp_redirect_cpu_user.c
new file mode 100644
index 000000000..16eb839e7
--- /dev/null
+++ b/samples/bpf/xdp_redirect_cpu_user.c
@@ -0,0 +1,983 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat, Inc.
+ */
+static const char *__doc__ =
+	" XDP redirect with a CPU-map type \"BPF_MAP_TYPE_CPUMAP\"";
+
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <locale.h>
+#include <sys/resource.h>
+#include <sys/sysinfo.h>
+#include <getopt.h>
+#include <net/if.h>
+#include <time.h>
+#include <linux/limits.h>
+
+#include <arpa/inet.h>
+#include <linux/if_link.h>
+
+/* How many xdp_progs are defined in _kern.c */
+#define MAX_PROG 6
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include "bpf_util.h"
+
+static int ifindex = -1;
+static char ifname_buf[IF_NAMESIZE];
+static char *ifname;
+static __u32 prog_id;
+
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static int n_cpus;
+
+enum map_type {
+	CPU_MAP,
+	RX_CNT,
+	REDIRECT_ERR_CNT,
+	CPUMAP_ENQUEUE_CNT,
+	CPUMAP_KTHREAD_CNT,
+	CPUS_AVAILABLE,
+	CPUS_COUNT,
+	CPUS_ITERATOR,
+	EXCEPTION_CNT,
+};
+
+static const char *const map_type_strings[] = {
+	[CPU_MAP] = "cpu_map",
+	[RX_CNT] = "rx_cnt",
+	[REDIRECT_ERR_CNT] = "redirect_err_cnt",
+	[CPUMAP_ENQUEUE_CNT] = "cpumap_enqueue_cnt",
+	[CPUMAP_KTHREAD_CNT] = "cpumap_kthread_cnt",
+	[CPUS_AVAILABLE] = "cpus_available",
+	[CPUS_COUNT] = "cpus_count",
+	[CPUS_ITERATOR] = "cpus_iterator",
+	[EXCEPTION_CNT] = "exception_cnt",
+};
+
+#define NUM_TP 5
+#define NUM_MAP 9
+struct bpf_link *tp_links[NUM_TP] = {};
+static int map_fds[NUM_MAP];
+static int tp_cnt = 0;
+
+/* Exit return codes */
+#define EXIT_OK		0
+#define EXIT_FAIL		1
+#define EXIT_FAIL_OPTION	2
+#define EXIT_FAIL_XDP		3
+#define EXIT_FAIL_BPF		4
+#define EXIT_FAIL_MEM		5
+
+static const struct option long_options[] = {
+	{"help",	no_argument,		NULL, 'h' },
+	{"dev",		required_argument,	NULL, 'd' },
+	{"skb-mode",	no_argument,		NULL, 'S' },
+	{"sec",		required_argument,	NULL, 's' },
+	{"progname",	required_argument,	NULL, 'p' },
+	{"qsize",	required_argument,	NULL, 'q' },
+	{"cpu",		required_argument,	NULL, 'c' },
+	{"stress-mode", no_argument,		NULL, 'x' },
+	{"no-separators", no_argument,		NULL, 'z' },
+	{"force",	no_argument,		NULL, 'F' },
+	{"mprog-disable", no_argument,		NULL, 'n' },
+	{"mprog-name",	required_argument,	NULL, 'e' },
+	{"mprog-filename", required_argument,	NULL, 'f' },
+	{"redirect-device", required_argument,	NULL, 'r' },
+	{"redirect-map", required_argument,	NULL, 'm' },
+	{0, 0, NULL,  0 }
+};
+
+static void int_exit(int sig)
+{
+	__u32 curr_prog_id = 0;
+
+	if (ifindex > -1) {
+		if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
+			printf("bpf_get_link_xdp_id failed\n");
+			exit(EXIT_FAIL);
+		}
+		if (prog_id == curr_prog_id) {
+			fprintf(stderr,
+				"Interrupted: Removing XDP program on ifindex:%d device:%s\n",
+				ifindex, ifname);
+			bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
+		} else if (!curr_prog_id) {
+			printf("couldn't find a prog id on a given iface\n");
+		} else {
+			printf("program on interface changed, not removing\n");
+		}
+	}
+	/* Detach tracepoints */
+	while (tp_cnt)
+		bpf_link__destroy(tp_links[--tp_cnt]);
+
+	exit(EXIT_OK);
+}
+
+static void print_avail_progs(struct bpf_object *obj)
+{
+	struct bpf_program *pos;
+
+	bpf_object__for_each_program(pos, obj) {
+		if (bpf_program__is_xdp(pos))
+			printf(" %s\n", bpf_program__section_name(pos));
+	}
+}
+
+static void usage(char *argv[], struct bpf_object *obj)
+{
+	int i;
+
+	printf("\nDOCUMENTATION:\n%s\n", __doc__);
+	printf("\n");
+	printf(" Usage: %s (options-see-below)\n", argv[0]);
+	printf(" Listing options:\n");
+	for (i = 0; long_options[i].name != 0; i++) {
+		printf(" --%-12s", long_options[i].name);
+		if (long_options[i].flag != NULL)
+			printf(" flag (internal value:%d)",
+				*long_options[i].flag);
+		else
+			printf(" short-option: -%c",
+				long_options[i].val);
+		printf("\n");
+	}
+	printf("\n Programs to be used for --progname:\n");
+	print_avail_progs(obj);
+	printf("\n");
+}
+
+/* gettime returns the current time of day in nanoseconds.
+ * Cost: clock_gettime (ns) => 26ns (CLOCK_MONOTONIC)
+ *       clock_gettime (ns) =>  9ns (CLOCK_MONOTONIC_COARSE)
+ */
+#define NANOSEC_PER_SEC 1000000000 /* 10^9 */
+static __u64 gettime(void)
+{
+	struct timespec t;
+	int res;
+
+	res = clock_gettime(CLOCK_MONOTONIC, &t);
+	if (res < 0) {
+		fprintf(stderr, "Error with gettimeofday! (%i)\n", res);
+		exit(EXIT_FAIL);
+	}
+	return (__u64) t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec;
+}
+
+/* Common stats data record shared with _kern.c */
+struct datarec {
+	__u64 processed;
+	__u64 dropped;
+	__u64 issue;
+	__u64 xdp_pass;
+	__u64 xdp_drop;
+	__u64 xdp_redirect;
+};
+struct record {
+	__u64 timestamp;
+	struct datarec total;
+	struct datarec *cpu;
+};
+struct stats_record {
+	struct record rx_cnt;
+	struct record redir_err;
+	struct record kthread;
+	struct record exception;
+	struct record enq[];
+};
+
+static bool map_collect_percpu(int fd, __u32 key, struct record *rec)
+{
+	/* For percpu maps, userspace gets a value per possible CPU */
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	struct datarec values[nr_cpus];
+	__u64 sum_xdp_redirect = 0;
+	__u64 sum_xdp_pass = 0;
+	__u64 sum_xdp_drop = 0;
+	__u64 sum_processed = 0;
+	__u64 sum_dropped = 0;
+	__u64 sum_issue = 0;
+	int i;
+
+	if ((bpf_map_lookup_elem(fd, &key, values)) != 0) {
+		fprintf(stderr,
+			"ERR: bpf_map_lookup_elem failed key:0x%X\n", key);
+		return false;
+	}
+	/* Get time as close as possible to reading map contents */
+	rec->timestamp = gettime();
+
+	/* Record and sum values from each CPU */
+	for (i = 0; i < nr_cpus; i++) {
+		rec->cpu[i].processed = values[i].processed;
+		sum_processed        += values[i].processed;
+		rec->cpu[i].dropped = values[i].dropped;
+		sum_dropped        += values[i].dropped;
+		rec->cpu[i].issue = values[i].issue;
+		sum_issue        += values[i].issue;
+		rec->cpu[i].xdp_pass = values[i].xdp_pass;
+		sum_xdp_pass += values[i].xdp_pass;
+		rec->cpu[i].xdp_drop = values[i].xdp_drop;
+		sum_xdp_drop += values[i].xdp_drop;
+		rec->cpu[i].xdp_redirect = values[i].xdp_redirect;
+		sum_xdp_redirect += values[i].xdp_redirect;
+	}
+	rec->total.processed = sum_processed;
+	rec->total.dropped   = sum_dropped;
+	rec->total.issue     = sum_issue;
+	rec->total.xdp_pass  = sum_xdp_pass;
+	rec->total.xdp_drop  = sum_xdp_drop;
+	rec->total.xdp_redirect = sum_xdp_redirect;
+	return true;
+}
+
+static struct datarec *alloc_record_per_cpu(void)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	struct datarec *array;
+
+	array = calloc(nr_cpus, sizeof(struct datarec));
+	if (!array) {
+		fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus);
+		exit(EXIT_FAIL_MEM);
+	}
+	return array;
+}
+
+static struct stats_record *alloc_stats_record(void)
+{
+	struct stats_record *rec;
+	int i, size;
+
+	size = sizeof(*rec) + n_cpus * sizeof(struct record);
+	rec = malloc(size);
+	if (!rec) {
+		fprintf(stderr, "Mem alloc error\n");
+		exit(EXIT_FAIL_MEM);
+	}
+	memset(rec, 0, size);
+	rec->rx_cnt.cpu    = alloc_record_per_cpu();
+	rec->redir_err.cpu = alloc_record_per_cpu();
+	rec->kthread.cpu   = alloc_record_per_cpu();
+	rec->exception.cpu = alloc_record_per_cpu();
+	for (i = 0; i < n_cpus; i++)
+		rec->enq[i].cpu = alloc_record_per_cpu();
+
+	return rec;
+}
+
+static void free_stats_record(struct stats_record *r)
+{
+	int i;
+
+	for (i = 0; i < n_cpus; i++)
+		free(r->enq[i].cpu);
+	free(r->exception.cpu);
+	free(r->kthread.cpu);
+	free(r->redir_err.cpu);
+	free(r->rx_cnt.cpu);
+	free(r);
+}
+
+static double calc_period(struct record *r, struct record *p)
+{
+	double period_ = 0;
+	__u64 period = 0;
+
+	period = r->timestamp - p->timestamp;
+	if (period > 0)
+		period_ = ((double) period / NANOSEC_PER_SEC);
+
+	return period_;
+}
+
+static __u64 calc_pps(struct datarec *r, struct datarec *p, double period_)
+{
+	__u64 packets = 0;
+	__u64 pps = 0;
+
+	if (period_ > 0) {
+		packets = r->processed - p->processed;
+		pps = packets / period_;
+	}
+	return pps;
+}
+
+static __u64 calc_drop_pps(struct datarec *r, struct datarec *p, double period_)
+{
+	__u64 packets = 0;
+	__u64 pps = 0;
+
+	if (period_ > 0) {
+		packets = r->dropped - p->dropped;
+		pps = packets / period_;
+	}
+	return pps;
+}
+
+static __u64 calc_errs_pps(struct datarec *r,
+			    struct datarec *p, double period_)
+{
+	__u64 packets = 0;
+	__u64 pps = 0;
+
+	if (period_ > 0) {
+		packets = r->issue - p->issue;
+		pps = packets / period_;
+	}
+	return pps;
+}
+
+static void calc_xdp_pps(struct datarec *r, struct datarec *p,
+			 double *xdp_pass, double *xdp_drop,
+			 double *xdp_redirect, double period_)
+{
+	*xdp_pass = 0, *xdp_drop = 0, *xdp_redirect = 0;
+	if (period_ > 0) {
+		*xdp_redirect = (r->xdp_redirect - p->xdp_redirect) / period_;
+		*xdp_pass = (r->xdp_pass - p->xdp_pass) / period_;
+		*xdp_drop = (r->xdp_drop - p->xdp_drop) / period_;
+	}
+}
+
+static void stats_print(struct stats_record *stats_rec,
+			struct stats_record *stats_prev,
+			char *prog_name, char *mprog_name, int mprog_fd)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	double pps = 0, drop = 0, err = 0;
+	bool mprog_enabled = false;
+	struct record *rec, *prev;
+	int to_cpu;
+	double t;
+	int i;
+
+	if (mprog_fd > 0)
+		mprog_enabled = true;
+
+	/* Header */
+	printf("Running XDP/eBPF prog_name:%s\n", prog_name);
+	printf("%-15s %-7s %-14s %-11s %-9s\n",
+	       "XDP-cpumap", "CPU:to", "pps", "drop-pps", "extra-info");
+
+	/* XDP rx_cnt */
+	{
+		char *fmt_rx = "%-15s %-7d %'-14.0f %'-11.0f %'-10.0f %s\n";
+		char *fm2_rx = "%-15s %-7s %'-14.0f %'-11.0f\n";
+		char *errstr = "";
+
+		rec  = &stats_rec->rx_cnt;
+		prev = &stats_prev->rx_cnt;
+		t = calc_period(rec, prev);
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+
+			pps = calc_pps(r, p, t);
+			drop = calc_drop_pps(r, p, t);
+			err  = calc_errs_pps(r, p, t);
+			if (err > 0)
+				errstr = "cpu-dest/err";
+			if (pps > 0)
+				printf(fmt_rx, "XDP-RX",
+					i, pps, drop, err, errstr);
+		}
+		pps  = calc_pps(&rec->total, &prev->total, t);
+		drop = calc_drop_pps(&rec->total, &prev->total, t);
+		err  = calc_errs_pps(&rec->total, &prev->total, t);
+		printf(fm2_rx, "XDP-RX", "total", pps, drop);
+	}
+
+	/* cpumap enqueue stats */
+	for (to_cpu = 0; to_cpu < n_cpus; to_cpu++) {
+		char *fmt = "%-15s %3d:%-3d %'-14.0f %'-11.0f %'-10.2f %s\n";
+		char *fm2 = "%-15s %3s:%-3d %'-14.0f %'-11.0f %'-10.2f %s\n";
+		char *errstr = "";
+
+		rec  =  &stats_rec->enq[to_cpu];
+		prev = &stats_prev->enq[to_cpu];
+		t = calc_period(rec, prev);
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+
+			pps  = calc_pps(r, p, t);
+			drop = calc_drop_pps(r, p, t);
+			err  = calc_errs_pps(r, p, t);
+			if (err > 0) {
+				errstr = "bulk-average";
+				err = pps / err; /* calc average bulk size */
+			}
+			if (pps > 0)
+				printf(fmt, "cpumap-enqueue",
+				       i, to_cpu, pps, drop, err, errstr);
+		}
+		pps = calc_pps(&rec->total, &prev->total, t);
+		if (pps > 0) {
+			drop = calc_drop_pps(&rec->total, &prev->total, t);
+			err  = calc_errs_pps(&rec->total, &prev->total, t);
+			if (err > 0) {
+				errstr = "bulk-average";
+				err = pps / err; /* calc average bulk size */
+			}
+			printf(fm2, "cpumap-enqueue",
+			       "sum", to_cpu, pps, drop, err, errstr);
+		}
+	}
+
+	/* cpumap kthread stats */
+	{
+		char *fmt_k = "%-15s %-7d %'-14.0f %'-11.0f %'-10.0f %s\n";
+		char *fm2_k = "%-15s %-7s %'-14.0f %'-11.0f %'-10.0f %s\n";
+		char *e_str = "";
+
+		rec  = &stats_rec->kthread;
+		prev = &stats_prev->kthread;
+		t = calc_period(rec, prev);
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+
+			pps  = calc_pps(r, p, t);
+			drop = calc_drop_pps(r, p, t);
+			err  = calc_errs_pps(r, p, t);
+			if (err > 0)
+				e_str = "sched";
+			if (pps > 0)
+				printf(fmt_k, "cpumap_kthread",
+				       i, pps, drop, err, e_str);
+		}
+		pps = calc_pps(&rec->total, &prev->total, t);
+		drop = calc_drop_pps(&rec->total, &prev->total, t);
+		err  = calc_errs_pps(&rec->total, &prev->total, t);
+		if (err > 0)
+			e_str = "sched-sum";
+		printf(fm2_k, "cpumap_kthread", "total", pps, drop, err, e_str);
+	}
+
+	/* XDP redirect err tracepoints (very unlikely) */
+	{
+		char *fmt_err = "%-15s %-7d %'-14.0f %'-11.0f\n";
+		char *fm2_err = "%-15s %-7s %'-14.0f %'-11.0f\n";
+
+		rec  = &stats_rec->redir_err;
+		prev = &stats_prev->redir_err;
+		t = calc_period(rec, prev);
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+
+			pps  = calc_pps(r, p, t);
+			drop = calc_drop_pps(r, p, t);
+			if (pps > 0)
+				printf(fmt_err, "redirect_err", i, pps, drop);
+		}
+		pps = calc_pps(&rec->total, &prev->total, t);
+		drop = calc_drop_pps(&rec->total, &prev->total, t);
+		printf(fm2_err, "redirect_err", "total", pps, drop);
+	}
+
+	/* XDP general exception tracepoints */
+	{
+		char *fmt_err = "%-15s %-7d %'-14.0f %'-11.0f\n";
+		char *fm2_err = "%-15s %-7s %'-14.0f %'-11.0f\n";
+
+		rec  = &stats_rec->exception;
+		prev = &stats_prev->exception;
+		t = calc_period(rec, prev);
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+
+			pps  = calc_pps(r, p, t);
+			drop = calc_drop_pps(r, p, t);
+			if (pps > 0)
+				printf(fmt_err, "xdp_exception", i, pps, drop);
+		}
+		pps = calc_pps(&rec->total, &prev->total, t);
+		drop = calc_drop_pps(&rec->total, &prev->total, t);
+		printf(fm2_err, "xdp_exception", "total", pps, drop);
+	}
+
+	/* CPUMAP attached XDP program that runs on remote/destination CPU */
+	if (mprog_enabled) {
+		char *fmt_k = "%-15s %-7d %'-14.0f %'-11.0f %'-10.0f\n";
+		char *fm2_k = "%-15s %-7s %'-14.0f %'-11.0f %'-10.0f\n";
+		double xdp_pass, xdp_drop, xdp_redirect;
+
+		printf("\n2nd remote XDP/eBPF prog_name: %s\n", mprog_name);
+		printf("%-15s %-7s %-14s %-11s %-9s\n",
+		       "XDP-cpumap", "CPU:to", "xdp-pass", "xdp-drop", "xdp-redir");
+
+		rec  = &stats_rec->kthread;
+		prev = &stats_prev->kthread;
+		t = calc_period(rec, prev);
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+
+			calc_xdp_pps(r, p, &xdp_pass, &xdp_drop,
+				     &xdp_redirect, t);
+			if (xdp_pass > 0 || xdp_drop > 0 || xdp_redirect > 0)
+				printf(fmt_k, "xdp-in-kthread", i, xdp_pass, xdp_drop,
+				       xdp_redirect);
+		}
+		calc_xdp_pps(&rec->total, &prev->total, &xdp_pass, &xdp_drop,
+			     &xdp_redirect, t);
+		printf(fm2_k, "xdp-in-kthread", "total", xdp_pass, xdp_drop, xdp_redirect);
+	}
+
+	printf("\n");
+	fflush(stdout);
+}
+
+static void stats_collect(struct stats_record *rec)
+{
+	int fd, i;
+
+	fd = map_fds[RX_CNT];
+	map_collect_percpu(fd, 0, &rec->rx_cnt);
+
+	fd = map_fds[REDIRECT_ERR_CNT];
+	map_collect_percpu(fd, 1, &rec->redir_err);
+
+	fd = map_fds[CPUMAP_ENQUEUE_CNT];
+	for (i = 0; i < n_cpus; i++)
+		map_collect_percpu(fd, i, &rec->enq[i]);
+
+	fd = map_fds[CPUMAP_KTHREAD_CNT];
+	map_collect_percpu(fd, 0, &rec->kthread);
+
+	fd = map_fds[EXCEPTION_CNT];
+	map_collect_percpu(fd, 0, &rec->exception);
+}
+
+
+/* Pointer swap trick */
+static inline void swap(struct stats_record **a, struct stats_record **b)
+{
+	struct stats_record *tmp;
+
+	tmp = *a;
+	*a = *b;
+	*b = tmp;
+}
+
+static int create_cpu_entry(__u32 cpu, struct bpf_cpumap_val *value,
+			    __u32 avail_idx, bool new)
+{
+	__u32 curr_cpus_count = 0;
+	__u32 key = 0;
+	int ret;
+
+	/* Add a CPU entry to cpumap, as this allocate a cpu entry in
+	 * the kernel for the cpu.
+	 */
+	ret = bpf_map_update_elem(map_fds[CPU_MAP], &cpu, value, 0);
+	if (ret) {
+		fprintf(stderr, "Create CPU entry failed (err:%d)\n", ret);
+		exit(EXIT_FAIL_BPF);
+	}
+
+	/* Inform bpf_prog's that a new CPU is available to select
+	 * from via some control maps.
+	 */
+	ret = bpf_map_update_elem(map_fds[CPUS_AVAILABLE], &avail_idx, &cpu, 0);
+	if (ret) {
+		fprintf(stderr, "Add to avail CPUs failed\n");
+		exit(EXIT_FAIL_BPF);
+	}
+
+	/* When not replacing/updating existing entry, bump the count */
+	ret = bpf_map_lookup_elem(map_fds[CPUS_COUNT], &key, &curr_cpus_count);
+	if (ret) {
+		fprintf(stderr, "Failed reading curr cpus_count\n");
+		exit(EXIT_FAIL_BPF);
+	}
+	if (new) {
+		curr_cpus_count++;
+		ret = bpf_map_update_elem(map_fds[CPUS_COUNT], &key,
+					  &curr_cpus_count, 0);
+		if (ret) {
+			fprintf(stderr, "Failed write curr cpus_count\n");
+			exit(EXIT_FAIL_BPF);
+		}
+	}
+	/* map_fd[7] = cpus_iterator */
+	printf("%s CPU:%u as idx:%u qsize:%d prog_fd: %d (cpus_count:%u)\n",
+	       new ? "Add-new":"Replace", cpu, avail_idx,
+	       value->qsize, value->bpf_prog.fd, curr_cpus_count);
+
+	return 0;
+}
+
+/* CPUs are zero-indexed. Thus, add a special sentinel default value
+ * in map cpus_available to mark CPU index'es not configured
+ */
+static void mark_cpus_unavailable(void)
+{
+	__u32 invalid_cpu = n_cpus;
+	int ret, i;
+
+	for (i = 0; i < n_cpus; i++) {
+		ret = bpf_map_update_elem(map_fds[CPUS_AVAILABLE], &i,
+					  &invalid_cpu, 0);
+		if (ret) {
+			fprintf(stderr, "Failed marking CPU unavailable\n");
+			exit(EXIT_FAIL_BPF);
+		}
+	}
+}
+
+/* Stress cpumap management code by concurrently changing underlying cpumap */
+static void stress_cpumap(struct bpf_cpumap_val *value)
+{
+	/* Changing qsize will cause kernel to free and alloc a new
+	 * bpf_cpu_map_entry, with an associated/complicated tear-down
+	 * procedure.
+	 */
+	value->qsize = 1024;
+	create_cpu_entry(1, value, 0, false);
+	value->qsize = 8;
+	create_cpu_entry(1, value, 0, false);
+	value->qsize = 16000;
+	create_cpu_entry(1, value, 0, false);
+}
+
+static void stats_poll(int interval, bool use_separators, char *prog_name,
+		       char *mprog_name, struct bpf_cpumap_val *value,
+		       bool stress_mode)
+{
+	struct stats_record *record, *prev;
+	int mprog_fd;
+
+	record = alloc_stats_record();
+	prev   = alloc_stats_record();
+	stats_collect(record);
+
+	/* Trick to pretty printf with thousands separators use %' */
+	if (use_separators)
+		setlocale(LC_NUMERIC, "en_US");
+
+	while (1) {
+		swap(&prev, &record);
+		mprog_fd = value->bpf_prog.fd;
+		stats_collect(record);
+		stats_print(record, prev, prog_name, mprog_name, mprog_fd);
+		sleep(interval);
+		if (stress_mode)
+			stress_cpumap(value);
+	}
+
+	free_stats_record(record);
+	free_stats_record(prev);
+}
+
+static int init_tracepoints(struct bpf_object *obj)
+{
+	struct bpf_program *prog;
+
+	bpf_object__for_each_program(prog, obj) {
+		if (bpf_program__is_tracepoint(prog) != true)
+			continue;
+
+		tp_links[tp_cnt] = bpf_program__attach(prog);
+		if (libbpf_get_error(tp_links[tp_cnt])) {
+			tp_links[tp_cnt] = NULL;
+			return -EINVAL;
+		}
+		tp_cnt++;
+	}
+
+	return 0;
+}
+
+static int init_map_fds(struct bpf_object *obj)
+{
+	enum map_type type;
+
+	for (type = 0; type < NUM_MAP; type++) {
+		map_fds[type] =
+			bpf_object__find_map_fd_by_name(obj,
+							map_type_strings[type]);
+
+		if (map_fds[type] < 0)
+			return -ENOENT;
+	}
+
+	return 0;
+}
+
+static int load_cpumap_prog(char *file_name, char *prog_name,
+			    char *redir_interface, char *redir_map)
+{
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type		= BPF_PROG_TYPE_XDP,
+		.expected_attach_type	= BPF_XDP_CPUMAP,
+		.file = file_name,
+	};
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	int fd;
+
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &fd))
+		return -1;
+
+	if (fd < 0) {
+		fprintf(stderr, "ERR: bpf_prog_load_xattr: %s\n",
+			strerror(errno));
+		return fd;
+	}
+
+	if (redir_interface && redir_map) {
+		int err, map_fd, ifindex_out, key = 0;
+
+		map_fd = bpf_object__find_map_fd_by_name(obj, redir_map);
+		if (map_fd < 0)
+			return map_fd;
+
+		ifindex_out = if_nametoindex(redir_interface);
+		if (!ifindex_out)
+			return -1;
+
+		err = bpf_map_update_elem(map_fd, &key, &ifindex_out, 0);
+		if (err < 0)
+			return err;
+	}
+
+	prog = bpf_object__find_program_by_title(obj, prog_name);
+	if (!prog) {
+		fprintf(stderr, "bpf_object__find_program_by_title failed\n");
+		return EXIT_FAIL;
+	}
+
+	return bpf_program__fd(prog);
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	char *prog_name = "xdp_cpu_map5_lb_hash_ip_pairs";
+	char *mprog_filename = "xdp_redirect_kern.o";
+	char *redir_interface = NULL, *redir_map = NULL;
+	char *mprog_name = "xdp_redirect_dummy";
+	bool mprog_disable = false;
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type	= BPF_PROG_TYPE_UNSPEC,
+	};
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	struct bpf_cpumap_val value;
+	bool use_separators = true;
+	bool stress_mode = false;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	int err = EXIT_FAIL;
+	char filename[256];
+	int added_cpus = 0;
+	int longindex = 0;
+	int interval = 2;
+	int add_cpu = -1;
+	int opt, prog_fd;
+	int *cpu, i;
+	__u32 qsize;
+
+	n_cpus = get_nprocs_conf();
+
+	/* Notice: choosing he queue size is very important with the
+	 * ixgbe driver, because it's driver page recycling trick is
+	 * dependend on pages being returned quickly.  The number of
+	 * out-standing packets in the system must be less-than 2x
+	 * RX-ring size.
+	 */
+	qsize = 128+64;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	prog_load_attr.file = filename;
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+		return err;
+
+	if (prog_fd < 0) {
+		fprintf(stderr, "ERR: bpf_prog_load_xattr: %s\n",
+			strerror(errno));
+		return err;
+	}
+
+	if (init_tracepoints(obj) < 0) {
+		fprintf(stderr, "ERR: bpf_program__attach failed\n");
+		return err;
+	}
+
+	if (init_map_fds(obj) < 0) {
+		fprintf(stderr, "bpf_object__find_map_fd_by_name failed\n");
+		return err;
+	}
+	mark_cpus_unavailable();
+
+	cpu = malloc(n_cpus * sizeof(int));
+	if (!cpu) {
+		fprintf(stderr, "failed to allocate cpu array\n");
+		return err;
+	}
+	memset(cpu, 0, n_cpus * sizeof(int));
+
+	/* Parse commands line args */
+	while ((opt = getopt_long(argc, argv, "hSd:s:p:q:c:xzFf:e:r:m:n",
+				  long_options, &longindex)) != -1) {
+		switch (opt) {
+		case 'd':
+			if (strlen(optarg) >= IF_NAMESIZE) {
+				fprintf(stderr, "ERR: --dev name too long\n");
+				goto error;
+			}
+			ifname = (char *)&ifname_buf;
+			strncpy(ifname, optarg, IF_NAMESIZE);
+			ifindex = if_nametoindex(ifname);
+			if (ifindex == 0) {
+				fprintf(stderr,
+					"ERR: --dev name unknown err(%d):%s\n",
+					errno, strerror(errno));
+				goto error;
+			}
+			break;
+		case 's':
+			interval = atoi(optarg);
+			break;
+		case 'S':
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
+			break;
+		case 'x':
+			stress_mode = true;
+			break;
+		case 'z':
+			use_separators = false;
+			break;
+		case 'p':
+			/* Selecting eBPF prog to load */
+			prog_name = optarg;
+			break;
+		case 'n':
+			mprog_disable = true;
+			break;
+		case 'f':
+			mprog_filename = optarg;
+			break;
+		case 'e':
+			mprog_name = optarg;
+			break;
+		case 'r':
+			redir_interface = optarg;
+			break;
+		case 'm':
+			redir_map = optarg;
+			break;
+		case 'c':
+			/* Add multiple CPUs */
+			add_cpu = strtoul(optarg, NULL, 0);
+			if (add_cpu >= n_cpus) {
+				fprintf(stderr,
+				"--cpu nr too large for cpumap err(%d):%s\n",
+					errno, strerror(errno));
+				goto error;
+			}
+			cpu[added_cpus++] = add_cpu;
+			break;
+		case 'q':
+			qsize = atoi(optarg);
+			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		case 'h':
+		error:
+		default:
+			free(cpu);
+			usage(argv, obj);
+			return EXIT_FAIL_OPTION;
+		}
+	}
+
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	/* Required option */
+	if (ifindex == -1) {
+		fprintf(stderr, "ERR: required option --dev missing\n");
+		usage(argv, obj);
+		err = EXIT_FAIL_OPTION;
+		goto out;
+	}
+	/* Required option */
+	if (add_cpu == -1) {
+		fprintf(stderr, "ERR: required option --cpu missing\n");
+		fprintf(stderr, " Specify multiple --cpu option to add more\n");
+		usage(argv, obj);
+		err = EXIT_FAIL_OPTION;
+		goto out;
+	}
+
+	value.bpf_prog.fd = 0;
+	if (!mprog_disable)
+		value.bpf_prog.fd = load_cpumap_prog(mprog_filename, mprog_name,
+						     redir_interface, redir_map);
+	if (value.bpf_prog.fd < 0) {
+		err = value.bpf_prog.fd;
+		goto out;
+	}
+	value.qsize = qsize;
+
+	for (i = 0; i < added_cpus; i++)
+		create_cpu_entry(cpu[i], &value, i, true);
+
+	/* Remove XDP program when program is interrupted or killed */
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	prog = bpf_object__find_program_by_title(obj, prog_name);
+	if (!prog) {
+		fprintf(stderr, "bpf_object__find_program_by_title failed\n");
+		goto out;
+	}
+
+	prog_fd = bpf_program__fd(prog);
+	if (prog_fd < 0) {
+		fprintf(stderr, "bpf_program__fd failed\n");
+		goto out;
+	}
+
+	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
+		fprintf(stderr, "link set xdp fd failed\n");
+		err = EXIT_FAIL_XDP;
+		goto out;
+	}
+
+	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
+	if (err) {
+		printf("can't get prog info - %s\n", strerror(errno));
+		goto out;
+	}
+	prog_id = info.id;
+
+	stats_poll(interval, use_separators, prog_name, mprog_name,
+		   &value, stress_mode);
+
+	err = EXIT_OK;
+out:
+	free(cpu);
+	return err;
+}
diff --git a/samples/bpf/xdp_redirect_kern.c b/samples/bpf/xdp_redirect_kern.c
new file mode 100644
index 000000000..d26ec3aa2
--- /dev/null
+++ b/samples/bpf/xdp_redirect_kern.c
@@ -0,0 +1,90 @@
+/* Copyright (c) 2016 John Fastabend <john.r.fastabend@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, int);
+	__type(value, int);
+	__uint(max_entries, 1);
+} tx_port SEC(".maps");
+
+/* Count RX packets, as XDP bpf_prog doesn't get direct TX-success
+ * feedback.  Redirect TX errors can be caught via a tracepoint.
+ */
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, 1);
+} rxcnt SEC(".maps");
+
+static void swap_src_dst_mac(void *data)
+{
+	unsigned short *p = data;
+	unsigned short dst[3];
+
+	dst[0] = p[0];
+	dst[1] = p[1];
+	dst[2] = p[2];
+	p[0] = p[3];
+	p[1] = p[4];
+	p[2] = p[5];
+	p[3] = dst[0];
+	p[4] = dst[1];
+	p[5] = dst[2];
+}
+
+SEC("xdp_redirect")
+int xdp_redirect_prog(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	int rc = XDP_DROP;
+	int *ifindex, port = 0;
+	long *value;
+	u32 key = 0;
+	u64 nh_off;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return rc;
+
+	ifindex = bpf_map_lookup_elem(&tx_port, &port);
+	if (!ifindex)
+		return rc;
+
+	value = bpf_map_lookup_elem(&rxcnt, &key);
+	if (value)
+		*value += 1;
+
+	swap_src_dst_mac(data);
+	return bpf_redirect(*ifindex, 0);
+}
+
+/* Redirect require an XDP bpf_prog loaded on the TX device */
+SEC("xdp_redirect_dummy")
+int xdp_redirect_dummy_prog(struct xdp_md *ctx)
+{
+	return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp_redirect_map_kern.c b/samples/bpf/xdp_redirect_map_kern.c
new file mode 100644
index 000000000..6489352ab
--- /dev/null
+++ b/samples/bpf/xdp_redirect_map_kern.c
@@ -0,0 +1,92 @@
+/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_DEVMAP);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(int));
+	__uint(max_entries, 100);
+} tx_port SEC(".maps");
+
+/* Count RX packets, as XDP bpf_prog doesn't get direct TX-success
+ * feedback.  Redirect TX errors can be caught via a tracepoint.
+ */
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, 1);
+} rxcnt SEC(".maps");
+
+static void swap_src_dst_mac(void *data)
+{
+	unsigned short *p = data;
+	unsigned short dst[3];
+
+	dst[0] = p[0];
+	dst[1] = p[1];
+	dst[2] = p[2];
+	p[0] = p[3];
+	p[1] = p[4];
+	p[2] = p[5];
+	p[3] = dst[0];
+	p[4] = dst[1];
+	p[5] = dst[2];
+}
+
+SEC("xdp_redirect_map")
+int xdp_redirect_map_prog(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	int rc = XDP_DROP;
+	int vport, port = 0, m = 0;
+	long *value;
+	u32 key = 0;
+	u64 nh_off;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return rc;
+
+	/* constant virtual port */
+	vport = 0;
+
+	/* count packet in global counter */
+	value = bpf_map_lookup_elem(&rxcnt, &key);
+	if (value)
+		*value += 1;
+
+	swap_src_dst_mac(data);
+
+	/* send packet out physical port */
+	return bpf_redirect_map(&tx_port, vport, 0);
+}
+
+/* Redirect require an XDP bpf_prog loaded on the TX device */
+SEC("xdp_redirect_dummy")
+int xdp_redirect_dummy_prog(struct xdp_md *ctx)
+{
+	return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp_redirect_map_user.c b/samples/bpf/xdp_redirect_map_user.c
new file mode 100644
index 000000000..35e16dee6
--- /dev/null
+++ b/samples/bpf/xdp_redirect_map_user.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
+ */
+#include <linux/bpf.h>
+#include <linux/if_link.h>
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <net/if.h>
+#include <unistd.h>
+#include <libgen.h>
+#include <sys/resource.h>
+
+#include "bpf_util.h"
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+static int ifindex_in;
+static int ifindex_out;
+static bool ifindex_out_xdp_dummy_attached = true;
+static __u32 prog_id;
+static __u32 dummy_prog_id;
+
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static int rxcnt_map_fd;
+
+static void int_exit(int sig)
+{
+	__u32 curr_prog_id = 0;
+
+	if (bpf_get_link_xdp_id(ifindex_in, &curr_prog_id, xdp_flags)) {
+		printf("bpf_get_link_xdp_id failed\n");
+		exit(1);
+	}
+	if (prog_id == curr_prog_id)
+		bpf_set_link_xdp_fd(ifindex_in, -1, xdp_flags);
+	else if (!curr_prog_id)
+		printf("couldn't find a prog id on iface IN\n");
+	else
+		printf("program on iface IN changed, not removing\n");
+
+	if (ifindex_out_xdp_dummy_attached) {
+		curr_prog_id = 0;
+		if (bpf_get_link_xdp_id(ifindex_out, &curr_prog_id,
+					xdp_flags)) {
+			printf("bpf_get_link_xdp_id failed\n");
+			exit(1);
+		}
+		if (dummy_prog_id == curr_prog_id)
+			bpf_set_link_xdp_fd(ifindex_out, -1, xdp_flags);
+		else if (!curr_prog_id)
+			printf("couldn't find a prog id on iface OUT\n");
+		else
+			printf("program on iface OUT changed, not removing\n");
+	}
+	exit(0);
+}
+
+static void poll_stats(int interval, int ifindex)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	__u64 values[nr_cpus], prev[nr_cpus];
+
+	memset(prev, 0, sizeof(prev));
+
+	while (1) {
+		__u64 sum = 0;
+		__u32 key = 0;
+		int i;
+
+		sleep(interval);
+		assert(bpf_map_lookup_elem(rxcnt_map_fd, &key, values) == 0);
+		for (i = 0; i < nr_cpus; i++)
+			sum += (values[i] - prev[i]);
+		if (sum)
+			printf("ifindex %i: %10llu pkt/s\n",
+			       ifindex, sum / interval);
+		memcpy(prev, values, sizeof(values));
+	}
+}
+
+static void usage(const char *prog)
+{
+	fprintf(stderr,
+		"usage: %s [OPTS] <IFNAME|IFINDEX>_IN <IFNAME|IFINDEX>_OUT\n\n"
+		"OPTS:\n"
+		"    -S    use skb-mode\n"
+		"    -N    enforce native mode\n"
+		"    -F    force loading prog\n",
+		prog);
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type	= BPF_PROG_TYPE_XDP,
+	};
+	struct bpf_program *prog, *dummy_prog;
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	int prog_fd, dummy_prog_fd;
+	const char *optstr = "FSN";
+	struct bpf_object *obj;
+	int ret, opt, key = 0;
+	char filename[256];
+	int tx_port_map_fd;
+
+	while ((opt = getopt(argc, argv, optstr)) != -1) {
+		switch (opt) {
+		case 'S':
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
+			break;
+		case 'N':
+			/* default, set below */
+			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		default:
+			usage(basename(argv[0]));
+			return 1;
+		}
+	}
+
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	if (optind == argc) {
+		printf("usage: %s <IFNAME|IFINDEX>_IN <IFNAME|IFINDEX>_OUT\n", argv[0]);
+		return 1;
+	}
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	ifindex_in = if_nametoindex(argv[optind]);
+	if (!ifindex_in)
+		ifindex_in = strtoul(argv[optind], NULL, 0);
+
+	ifindex_out = if_nametoindex(argv[optind + 1]);
+	if (!ifindex_out)
+		ifindex_out = strtoul(argv[optind + 1], NULL, 0);
+
+	printf("input: %d output: %d\n", ifindex_in, ifindex_out);
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	prog_load_attr.file = filename;
+
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+		return 1;
+
+	prog = bpf_program__next(NULL, obj);
+	dummy_prog = bpf_program__next(prog, obj);
+	if (!prog || !dummy_prog) {
+		printf("finding a prog in obj file failed\n");
+		return 1;
+	}
+	/* bpf_prog_load_xattr gives us the pointer to first prog's fd,
+	 * so we're missing only the fd for dummy prog
+	 */
+	dummy_prog_fd = bpf_program__fd(dummy_prog);
+	if (prog_fd < 0 || dummy_prog_fd < 0) {
+		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
+		return 1;
+	}
+
+	tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port");
+	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
+	if (tx_port_map_fd < 0 || rxcnt_map_fd < 0) {
+		printf("bpf_object__find_map_fd_by_name failed\n");
+		return 1;
+	}
+
+	if (bpf_set_link_xdp_fd(ifindex_in, prog_fd, xdp_flags) < 0) {
+		printf("ERROR: link set xdp fd failed on %d\n", ifindex_in);
+		return 1;
+	}
+
+	ret = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
+	if (ret) {
+		printf("can't get prog info - %s\n", strerror(errno));
+		return ret;
+	}
+	prog_id = info.id;
+
+	/* Loading dummy XDP prog on out-device */
+	if (bpf_set_link_xdp_fd(ifindex_out, dummy_prog_fd,
+			    (xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST)) < 0) {
+		printf("WARN: link set xdp fd failed on %d\n", ifindex_out);
+		ifindex_out_xdp_dummy_attached = false;
+	}
+
+	memset(&info, 0, sizeof(info));
+	ret = bpf_obj_get_info_by_fd(dummy_prog_fd, &info, &info_len);
+	if (ret) {
+		printf("can't get prog info - %s\n", strerror(errno));
+		return ret;
+	}
+	dummy_prog_id = info.id;
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	/* populate virtual to physical port map */
+	ret = bpf_map_update_elem(tx_port_map_fd, &key, &ifindex_out, 0);
+	if (ret) {
+		perror("bpf_update_elem");
+		goto out;
+	}
+
+	poll_stats(2, ifindex_out);
+
+out:
+	return 0;
+}
diff --git a/samples/bpf/xdp_redirect_user.c b/samples/bpf/xdp_redirect_user.c
new file mode 100644
index 000000000..3c92adc2a
--- /dev/null
+++ b/samples/bpf/xdp_redirect_user.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 John Fastabend <john.r.fastabend@intel.com>
+ */
+#include <linux/bpf.h>
+#include <linux/if_link.h>
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <net/if.h>
+#include <unistd.h>
+#include <libgen.h>
+#include <sys/resource.h>
+
+#include "bpf_util.h"
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+static int ifindex_in;
+static int ifindex_out;
+static bool ifindex_out_xdp_dummy_attached = true;
+static __u32 prog_id;
+static __u32 dummy_prog_id;
+
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static int rxcnt_map_fd;
+
+static void int_exit(int sig)
+{
+	__u32 curr_prog_id = 0;
+
+	if (bpf_get_link_xdp_id(ifindex_in, &curr_prog_id, xdp_flags)) {
+		printf("bpf_get_link_xdp_id failed\n");
+		exit(1);
+	}
+	if (prog_id == curr_prog_id)
+		bpf_set_link_xdp_fd(ifindex_in, -1, xdp_flags);
+	else if (!curr_prog_id)
+		printf("couldn't find a prog id on iface IN\n");
+	else
+		printf("program on iface IN changed, not removing\n");
+
+	if (ifindex_out_xdp_dummy_attached) {
+		curr_prog_id = 0;
+		if (bpf_get_link_xdp_id(ifindex_out, &curr_prog_id,
+					xdp_flags)) {
+			printf("bpf_get_link_xdp_id failed\n");
+			exit(1);
+		}
+		if (dummy_prog_id == curr_prog_id)
+			bpf_set_link_xdp_fd(ifindex_out, -1, xdp_flags);
+		else if (!curr_prog_id)
+			printf("couldn't find a prog id on iface OUT\n");
+		else
+			printf("program on iface OUT changed, not removing\n");
+	}
+	exit(0);
+}
+
+static void poll_stats(int interval, int ifindex)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	__u64 values[nr_cpus], prev[nr_cpus];
+
+	memset(prev, 0, sizeof(prev));
+
+	while (1) {
+		__u64 sum = 0;
+		__u32 key = 0;
+		int i;
+
+		sleep(interval);
+		assert(bpf_map_lookup_elem(rxcnt_map_fd, &key, values) == 0);
+		for (i = 0; i < nr_cpus; i++)
+			sum += (values[i] - prev[i]);
+		if (sum)
+			printf("ifindex %i: %10llu pkt/s\n",
+			       ifindex, sum / interval);
+		memcpy(prev, values, sizeof(values));
+	}
+}
+
+static void usage(const char *prog)
+{
+	fprintf(stderr,
+		"usage: %s [OPTS] <IFNAME|IFINDEX>_IN <IFNAME|IFINDEX>_OUT\n\n"
+		"OPTS:\n"
+		"    -S    use skb-mode\n"
+		"    -N    enforce native mode\n"
+		"    -F    force loading prog\n",
+		prog);
+}
+
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type	= BPF_PROG_TYPE_XDP,
+	};
+	struct bpf_program *prog, *dummy_prog;
+	int prog_fd, tx_port_map_fd, opt;
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	const char *optstr = "FSN";
+	struct bpf_object *obj;
+	char filename[256];
+	int dummy_prog_fd;
+	int ret, key = 0;
+
+	while ((opt = getopt(argc, argv, optstr)) != -1) {
+		switch (opt) {
+		case 'S':
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
+			break;
+		case 'N':
+			/* default, set below */
+			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		default:
+			usage(basename(argv[0]));
+			return 1;
+		}
+	}
+
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	if (optind + 2 != argc) {
+		printf("usage: %s <IFNAME|IFINDEX>_IN <IFNAME|IFINDEX>_OUT\n", argv[0]);
+		return 1;
+	}
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	ifindex_in = if_nametoindex(argv[optind]);
+	if (!ifindex_in)
+		ifindex_in = strtoul(argv[optind], NULL, 0);
+
+	ifindex_out = if_nametoindex(argv[optind + 1]);
+	if (!ifindex_out)
+		ifindex_out = strtoul(argv[optind + 1], NULL, 0);
+
+	printf("input: %d output: %d\n", ifindex_in, ifindex_out);
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	prog_load_attr.file = filename;
+
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+		return 1;
+
+	prog = bpf_program__next(NULL, obj);
+	dummy_prog = bpf_program__next(prog, obj);
+	if (!prog || !dummy_prog) {
+		printf("finding a prog in obj file failed\n");
+		return 1;
+	}
+	/* bpf_prog_load_xattr gives us the pointer to first prog's fd,
+	 * so we're missing only the fd for dummy prog
+	 */
+	dummy_prog_fd = bpf_program__fd(dummy_prog);
+	if (prog_fd < 0 || dummy_prog_fd < 0) {
+		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
+		return 1;
+	}
+
+	tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port");
+	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
+	if (tx_port_map_fd < 0 || rxcnt_map_fd < 0) {
+		printf("bpf_object__find_map_fd_by_name failed\n");
+		return 1;
+	}
+
+	if (bpf_set_link_xdp_fd(ifindex_in, prog_fd, xdp_flags) < 0) {
+		printf("ERROR: link set xdp fd failed on %d\n", ifindex_in);
+		return 1;
+	}
+
+	ret = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
+	if (ret) {
+		printf("can't get prog info - %s\n", strerror(errno));
+		return ret;
+	}
+	prog_id = info.id;
+
+	/* Loading dummy XDP prog on out-device */
+	if (bpf_set_link_xdp_fd(ifindex_out, dummy_prog_fd,
+			    (xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST)) < 0) {
+		printf("WARN: link set xdp fd failed on %d\n", ifindex_out);
+		ifindex_out_xdp_dummy_attached = false;
+	}
+
+	memset(&info, 0, sizeof(info));
+	ret = bpf_obj_get_info_by_fd(dummy_prog_fd, &info, &info_len);
+	if (ret) {
+		printf("can't get prog info - %s\n", strerror(errno));
+		return ret;
+	}
+	dummy_prog_id = info.id;
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	/* bpf redirect port */
+	ret = bpf_map_update_elem(tx_port_map_fd, &key, &ifindex_out, 0);
+	if (ret) {
+		perror("bpf_update_elem");
+		goto out;
+	}
+
+	poll_stats(2, ifindex_out);
+
+out:
+	return ret;
+}
diff --git a/samples/bpf/xdp_router_ipv4_kern.c b/samples/bpf/xdp_router_ipv4_kern.c
new file mode 100644
index 000000000..b37ca2b13
--- /dev/null
+++ b/samples/bpf/xdp_router_ipv4_kern.c
@@ -0,0 +1,186 @@
+/* Copyright (C) 2017 Cavium, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <bpf/bpf_helpers.h>
+#include <linux/slab.h>
+#include <net/ip_fib.h>
+
+struct trie_value {
+	__u8 prefix[4];
+	__be64 value;
+	int ifindex;
+	int metric;
+	__be32 gw;
+};
+
+/* Key for lpm_trie*/
+union key_4 {
+	u32 b32[2];
+	u8 b8[8];
+};
+
+struct arp_entry {
+	__be64 mac;
+	__be32 dst;
+};
+
+struct direct_map {
+	struct arp_entry arp;
+	int ifindex;
+	__be64 mac;
+};
+
+/* Map for trie implementation*/
+struct {
+	__uint(type, BPF_MAP_TYPE_LPM_TRIE);
+	__uint(key_size, 8);
+	__uint(value_size, sizeof(struct trie_value));
+	__uint(max_entries, 50);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+} lpm_map SEC(".maps");
+
+/* Map for counter*/
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, u64);
+	__uint(max_entries, 256);
+} rxcnt SEC(".maps");
+
+/* Map for ARP table*/
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, __be32);
+	__type(value, __be64);
+	__uint(max_entries, 50);
+} arp_table SEC(".maps");
+
+/* Map to keep the exact match entries in the route table*/
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, __be32);
+	__type(value, struct direct_map);
+	__uint(max_entries, 50);
+} exact_match SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_DEVMAP);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(int));
+	__uint(max_entries, 100);
+} tx_port SEC(".maps");
+
+/* Function to set source and destination mac of the packet */
+static inline void set_src_dst_mac(void *data, void *src, void *dst)
+{
+	unsigned short *source = src;
+	unsigned short *dest  = dst;
+	unsigned short *p = data;
+
+	__builtin_memcpy(p, dest, 6);
+	__builtin_memcpy(p + 3, source, 6);
+}
+
+/* Parse IPV4 packet to get SRC, DST IP and protocol */
+static inline int parse_ipv4(void *data, u64 nh_off, void *data_end,
+			     __be32 *src, __be32 *dest)
+{
+	struct iphdr *iph = data + nh_off;
+
+	if (iph + 1 > data_end)
+		return 0;
+	*src = iph->saddr;
+	*dest = iph->daddr;
+	return iph->protocol;
+}
+
+SEC("xdp_router_ipv4")
+int xdp_router_ipv4_prog(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	__be64 *dest_mac = NULL, *src_mac = NULL;
+	void *data = (void *)(long)ctx->data;
+	struct trie_value *prefix_value;
+	int rc = XDP_DROP, forward_to;
+	struct ethhdr *eth = data;
+	union key_4 key4;
+	long *value;
+	u16 h_proto;
+	u32 ipproto;
+	u64 nh_off;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return rc;
+
+	h_proto = eth->h_proto;
+
+	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return rc;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+	if (h_proto == htons(ETH_P_ARP)) {
+		return XDP_PASS;
+	} else if (h_proto == htons(ETH_P_IP)) {
+		struct direct_map *direct_entry;
+		__be32 src_ip = 0, dest_ip = 0;
+
+		ipproto = parse_ipv4(data, nh_off, data_end, &src_ip, &dest_ip);
+		direct_entry = bpf_map_lookup_elem(&exact_match, &dest_ip);
+		/* Check for exact match, this would give a faster lookup*/
+		if (direct_entry && direct_entry->mac && direct_entry->arp.mac) {
+			src_mac = &direct_entry->mac;
+			dest_mac = &direct_entry->arp.mac;
+			forward_to = direct_entry->ifindex;
+		} else {
+			/* Look up in the trie for lpm*/
+			key4.b32[0] = 32;
+			key4.b8[4] = dest_ip & 0xff;
+			key4.b8[5] = (dest_ip >> 8) & 0xff;
+			key4.b8[6] = (dest_ip >> 16) & 0xff;
+			key4.b8[7] = (dest_ip >> 24) & 0xff;
+			prefix_value = bpf_map_lookup_elem(&lpm_map, &key4);
+			if (!prefix_value)
+				return XDP_DROP;
+			src_mac = &prefix_value->value;
+			if (!src_mac)
+				return XDP_DROP;
+			dest_mac = bpf_map_lookup_elem(&arp_table, &dest_ip);
+			if (!dest_mac) {
+				if (!prefix_value->gw)
+					return XDP_DROP;
+				dest_ip = prefix_value->gw;
+				dest_mac = bpf_map_lookup_elem(&arp_table, &dest_ip);
+			}
+			forward_to = prefix_value->ifindex;
+		}
+	} else {
+		ipproto = 0;
+	}
+	if (src_mac && dest_mac) {
+		set_src_dst_mac(data, src_mac, dest_mac);
+		value = bpf_map_lookup_elem(&rxcnt, &ipproto);
+		if (value)
+			*value += 1;
+		return  bpf_redirect_map(&tx_port, forward_to, 0);
+	}
+	return rc;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp_router_ipv4_user.c b/samples/bpf/xdp_router_ipv4_user.c
new file mode 100644
index 000000000..c2da1b51f
--- /dev/null
+++ b/samples/bpf/xdp_router_ipv4_user.c
@@ -0,0 +1,741 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2017 Cavium, Inc.
+ */
+#include <linux/bpf.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <bpf/bpf.h>
+#include <arpa/inet.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <net/if.h>
+#include <netdb.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+#include "bpf_util.h"
+#include <bpf/libbpf.h>
+#include <sys/resource.h>
+#include <libgen.h>
+
+int sock, sock_arp, flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static int total_ifindex;
+static int *ifindex_list;
+static __u32 *prog_id_list;
+char buf[8192];
+static int lpm_map_fd;
+static int rxcnt_map_fd;
+static int arp_table_map_fd;
+static int exact_match_map_fd;
+static int tx_port_map_fd;
+
+static int get_route_table(int rtm_family);
+static void int_exit(int sig)
+{
+	__u32 prog_id = 0;
+	int i = 0;
+
+	for (i = 0; i < total_ifindex; i++) {
+		if (bpf_get_link_xdp_id(ifindex_list[i], &prog_id, flags)) {
+			printf("bpf_get_link_xdp_id on iface %d failed\n",
+			       ifindex_list[i]);
+			exit(1);
+		}
+		if (prog_id_list[i] == prog_id)
+			bpf_set_link_xdp_fd(ifindex_list[i], -1, flags);
+		else if (!prog_id)
+			printf("couldn't find a prog id on iface %d\n",
+			       ifindex_list[i]);
+		else
+			printf("program on iface %d changed, not removing\n",
+			       ifindex_list[i]);
+		prog_id = 0;
+	}
+	exit(0);
+}
+
+static void close_and_exit(int sig)
+{
+	close(sock);
+	close(sock_arp);
+
+	int_exit(0);
+}
+
+/* Get the mac address of the interface given interface name */
+static __be64 getmac(char *iface)
+{
+	struct ifreq ifr;
+	__be64 mac = 0;
+	int fd, i;
+
+	fd = socket(AF_INET, SOCK_DGRAM, 0);
+	ifr.ifr_addr.sa_family = AF_INET;
+	strncpy(ifr.ifr_name, iface, IFNAMSIZ - 1);
+	if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
+		printf("ioctl failed leaving....\n");
+		return -1;
+	}
+	for (i = 0; i < 6 ; i++)
+		*((__u8 *)&mac + i) = (__u8)ifr.ifr_hwaddr.sa_data[i];
+	close(fd);
+	return mac;
+}
+
+static int recv_msg(struct sockaddr_nl sock_addr, int sock)
+{
+	struct nlmsghdr *nh;
+	int len, nll = 0;
+	char *buf_ptr;
+
+	buf_ptr = buf;
+	while (1) {
+		len = recv(sock, buf_ptr, sizeof(buf) - nll, 0);
+		if (len < 0)
+			return len;
+
+		nh = (struct nlmsghdr *)buf_ptr;
+
+		if (nh->nlmsg_type == NLMSG_DONE)
+			break;
+		buf_ptr += len;
+		nll += len;
+		if ((sock_addr.nl_groups & RTMGRP_NEIGH) == RTMGRP_NEIGH)
+			break;
+
+		if ((sock_addr.nl_groups & RTMGRP_IPV4_ROUTE) == RTMGRP_IPV4_ROUTE)
+			break;
+	}
+	return nll;
+}
+
+/* Function to parse the route entry returned by netlink
+ * Updates the route entry related map entries
+ */
+static void read_route(struct nlmsghdr *nh, int nll)
+{
+	char dsts[24], gws[24], ifs[16], dsts_len[24], metrics[24];
+	struct bpf_lpm_trie_key *prefix_key;
+	struct rtattr *rt_attr;
+	struct rtmsg *rt_msg;
+	int rtm_family;
+	int rtl;
+	int i;
+	struct route_table {
+		int  dst_len, iface, metric;
+		char *iface_name;
+		__be32 dst, gw;
+		__be64 mac;
+	} route;
+	struct arp_table {
+		__be64 mac;
+		__be32 dst;
+	};
+
+	struct direct_map {
+		struct arp_table arp;
+		int ifindex;
+		__be64 mac;
+	} direct_entry;
+
+	if (nh->nlmsg_type == RTM_DELROUTE)
+		printf("DELETING Route entry\n");
+	else if (nh->nlmsg_type == RTM_GETROUTE)
+		printf("READING Route entry\n");
+	else if (nh->nlmsg_type == RTM_NEWROUTE)
+		printf("NEW Route entry\n");
+	else
+		printf("%d\n", nh->nlmsg_type);
+
+	memset(&route, 0, sizeof(route));
+	printf("Destination\t\tGateway\t\tGenmask\t\tMetric\t\tIface\n");
+	for (; NLMSG_OK(nh, nll); nh = NLMSG_NEXT(nh, nll)) {
+		rt_msg = (struct rtmsg *)NLMSG_DATA(nh);
+		rtm_family = rt_msg->rtm_family;
+		if (rtm_family == AF_INET)
+			if (rt_msg->rtm_table != RT_TABLE_MAIN)
+				continue;
+		rt_attr = (struct rtattr *)RTM_RTA(rt_msg);
+		rtl = RTM_PAYLOAD(nh);
+
+		for (; RTA_OK(rt_attr, rtl); rt_attr = RTA_NEXT(rt_attr, rtl)) {
+			switch (rt_attr->rta_type) {
+			case NDA_DST:
+				sprintf(dsts, "%u",
+					(*((__be32 *)RTA_DATA(rt_attr))));
+				break;
+			case RTA_GATEWAY:
+				sprintf(gws, "%u",
+					*((__be32 *)RTA_DATA(rt_attr)));
+				break;
+			case RTA_OIF:
+				sprintf(ifs, "%u",
+					*((int *)RTA_DATA(rt_attr)));
+				break;
+			case RTA_METRICS:
+				sprintf(metrics, "%u",
+					*((int *)RTA_DATA(rt_attr)));
+			default:
+				break;
+			}
+		}
+		sprintf(dsts_len, "%d", rt_msg->rtm_dst_len);
+		route.dst = atoi(dsts);
+		route.dst_len = atoi(dsts_len);
+		route.gw = atoi(gws);
+		route.iface = atoi(ifs);
+		route.metric = atoi(metrics);
+		route.iface_name = alloca(sizeof(char *) * IFNAMSIZ);
+		route.iface_name = if_indextoname(route.iface, route.iface_name);
+		route.mac = getmac(route.iface_name);
+		if (route.mac == -1)
+			int_exit(0);
+		assert(bpf_map_update_elem(tx_port_map_fd,
+					   &route.iface, &route.iface, 0) == 0);
+		if (rtm_family == AF_INET) {
+			struct trie_value {
+				__u8 prefix[4];
+				__be64 value;
+				int ifindex;
+				int metric;
+				__be32 gw;
+			} *prefix_value;
+
+			prefix_key = alloca(sizeof(*prefix_key) + 3);
+			prefix_value = alloca(sizeof(*prefix_value));
+
+			prefix_key->prefixlen = 32;
+			prefix_key->prefixlen = route.dst_len;
+			direct_entry.mac = route.mac & 0xffffffffffff;
+			direct_entry.ifindex = route.iface;
+			direct_entry.arp.mac = 0;
+			direct_entry.arp.dst = 0;
+			if (route.dst_len == 32) {
+				if (nh->nlmsg_type == RTM_DELROUTE) {
+					assert(bpf_map_delete_elem(exact_match_map_fd,
+								   &route.dst) == 0);
+				} else {
+					if (bpf_map_lookup_elem(arp_table_map_fd,
+								&route.dst,
+								&direct_entry.arp.mac) == 0)
+						direct_entry.arp.dst = route.dst;
+					assert(bpf_map_update_elem(exact_match_map_fd,
+								   &route.dst,
+								   &direct_entry, 0) == 0);
+				}
+			}
+			for (i = 0; i < 4; i++)
+				prefix_key->data[i] = (route.dst >> i * 8) & 0xff;
+
+			printf("%3d.%d.%d.%d\t\t%3x\t\t%d\t\t%d\t\t%s\n",
+			       (int)prefix_key->data[0],
+			       (int)prefix_key->data[1],
+			       (int)prefix_key->data[2],
+			       (int)prefix_key->data[3],
+			       route.gw, route.dst_len,
+			       route.metric,
+			       route.iface_name);
+			if (bpf_map_lookup_elem(lpm_map_fd, prefix_key,
+						prefix_value) < 0) {
+				for (i = 0; i < 4; i++)
+					prefix_value->prefix[i] = prefix_key->data[i];
+				prefix_value->value = route.mac & 0xffffffffffff;
+				prefix_value->ifindex = route.iface;
+				prefix_value->gw = route.gw;
+				prefix_value->metric = route.metric;
+
+				assert(bpf_map_update_elem(lpm_map_fd,
+							   prefix_key,
+							   prefix_value, 0
+							   ) == 0);
+			} else {
+				if (nh->nlmsg_type == RTM_DELROUTE) {
+					printf("deleting entry\n");
+					printf("prefix key=%d.%d.%d.%d/%d",
+					       prefix_key->data[0],
+					       prefix_key->data[1],
+					       prefix_key->data[2],
+					       prefix_key->data[3],
+					       prefix_key->prefixlen);
+					assert(bpf_map_delete_elem(lpm_map_fd,
+								   prefix_key
+								   ) == 0);
+					/* Rereading the route table to check if
+					 * there is an entry with the same
+					 * prefix but a different metric as the
+					 * deleted enty.
+					 */
+					get_route_table(AF_INET);
+				} else if (prefix_key->data[0] ==
+					   prefix_value->prefix[0] &&
+					   prefix_key->data[1] ==
+					   prefix_value->prefix[1] &&
+					   prefix_key->data[2] ==
+					   prefix_value->prefix[2] &&
+					   prefix_key->data[3] ==
+					   prefix_value->prefix[3] &&
+					   route.metric >= prefix_value->metric) {
+					continue;
+				} else {
+					for (i = 0; i < 4; i++)
+						prefix_value->prefix[i] =
+							prefix_key->data[i];
+					prefix_value->value =
+						route.mac & 0xffffffffffff;
+					prefix_value->ifindex = route.iface;
+					prefix_value->gw = route.gw;
+					prefix_value->metric = route.metric;
+					assert(bpf_map_update_elem(lpm_map_fd,
+								   prefix_key,
+								   prefix_value,
+								   0) == 0);
+				}
+			}
+		}
+		memset(&route, 0, sizeof(route));
+		memset(dsts, 0, sizeof(dsts));
+		memset(dsts_len, 0, sizeof(dsts_len));
+		memset(gws, 0, sizeof(gws));
+		memset(ifs, 0, sizeof(ifs));
+		memset(&route, 0, sizeof(route));
+	}
+}
+
+/* Function to read the existing route table  when the process is launched*/
+static int get_route_table(int rtm_family)
+{
+	struct sockaddr_nl sa;
+	struct nlmsghdr *nh;
+	int sock, seq = 0;
+	struct msghdr msg;
+	struct iovec iov;
+	int ret = 0;
+	int nll;
+
+	struct {
+		struct nlmsghdr nl;
+		struct rtmsg rt;
+		char buf[8192];
+	} req;
+
+	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	if (sock < 0) {
+		printf("open netlink socket: %s\n", strerror(errno));
+		return -1;
+	}
+	memset(&sa, 0, sizeof(sa));
+	sa.nl_family = AF_NETLINK;
+	if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
+		printf("bind to netlink: %s\n", strerror(errno));
+		ret = -1;
+		goto cleanup;
+	}
+	memset(&req, 0, sizeof(req));
+	req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
+	req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
+	req.nl.nlmsg_type = RTM_GETROUTE;
+
+	req.rt.rtm_family = rtm_family;
+	req.rt.rtm_table = RT_TABLE_MAIN;
+	req.nl.nlmsg_pid = 0;
+	req.nl.nlmsg_seq = ++seq;
+	memset(&msg, 0, sizeof(msg));
+	iov.iov_base = (void *)&req.nl;
+	iov.iov_len = req.nl.nlmsg_len;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	ret = sendmsg(sock, &msg, 0);
+	if (ret < 0) {
+		printf("send to netlink: %s\n", strerror(errno));
+		ret = -1;
+		goto cleanup;
+	}
+	memset(buf, 0, sizeof(buf));
+	nll = recv_msg(sa, sock);
+	if (nll < 0) {
+		printf("recv from netlink: %s\n", strerror(nll));
+		ret = -1;
+		goto cleanup;
+	}
+	nh = (struct nlmsghdr *)buf;
+	read_route(nh, nll);
+cleanup:
+	close(sock);
+	return ret;
+}
+
+/* Function to parse the arp entry returned by netlink
+ * Updates the arp entry related map entries
+ */
+static void read_arp(struct nlmsghdr *nh, int nll)
+{
+	struct rtattr *rt_attr;
+	char dsts[24], mac[24];
+	struct ndmsg *rt_msg;
+	int rtl, ndm_family;
+
+	struct arp_table {
+		__be64 mac;
+		__be32 dst;
+	} arp_entry;
+	struct direct_map {
+		struct arp_table arp;
+		int ifindex;
+		__be64 mac;
+	} direct_entry;
+
+	if (nh->nlmsg_type == RTM_GETNEIGH)
+		printf("READING arp entry\n");
+	printf("Address\tHwAddress\n");
+	for (; NLMSG_OK(nh, nll); nh = NLMSG_NEXT(nh, nll)) {
+		rt_msg = (struct ndmsg *)NLMSG_DATA(nh);
+		rt_attr = (struct rtattr *)RTM_RTA(rt_msg);
+		ndm_family = rt_msg->ndm_family;
+		rtl = RTM_PAYLOAD(nh);
+		for (; RTA_OK(rt_attr, rtl); rt_attr = RTA_NEXT(rt_attr, rtl)) {
+			switch (rt_attr->rta_type) {
+			case NDA_DST:
+				sprintf(dsts, "%u",
+					*((__be32 *)RTA_DATA(rt_attr)));
+				break;
+			case NDA_LLADDR:
+				sprintf(mac, "%lld",
+					*((__be64 *)RTA_DATA(rt_attr)));
+				break;
+			default:
+				break;
+			}
+		}
+		arp_entry.dst = atoi(dsts);
+		arp_entry.mac = atol(mac);
+		printf("%x\t\t%llx\n", arp_entry.dst, arp_entry.mac);
+		if (ndm_family == AF_INET) {
+			if (bpf_map_lookup_elem(exact_match_map_fd,
+						&arp_entry.dst,
+						&direct_entry) == 0) {
+				if (nh->nlmsg_type == RTM_DELNEIGH) {
+					direct_entry.arp.dst = 0;
+					direct_entry.arp.mac = 0;
+				} else if (nh->nlmsg_type == RTM_NEWNEIGH) {
+					direct_entry.arp.dst = arp_entry.dst;
+					direct_entry.arp.mac = arp_entry.mac;
+				}
+				assert(bpf_map_update_elem(exact_match_map_fd,
+							   &arp_entry.dst,
+							   &direct_entry, 0
+							   ) == 0);
+				memset(&direct_entry, 0, sizeof(direct_entry));
+			}
+			if (nh->nlmsg_type == RTM_DELNEIGH) {
+				assert(bpf_map_delete_elem(arp_table_map_fd,
+							   &arp_entry.dst) == 0);
+			} else if (nh->nlmsg_type == RTM_NEWNEIGH) {
+				assert(bpf_map_update_elem(arp_table_map_fd,
+							   &arp_entry.dst,
+							   &arp_entry.mac, 0
+							   ) == 0);
+			}
+		}
+		memset(&arp_entry, 0, sizeof(arp_entry));
+		memset(dsts, 0, sizeof(dsts));
+	}
+}
+
+/* Function to read the existing arp table  when the process is launched*/
+static int get_arp_table(int rtm_family)
+{
+	struct sockaddr_nl sa;
+	struct nlmsghdr *nh;
+	int sock, seq = 0;
+	struct msghdr msg;
+	struct iovec iov;
+	int ret = 0;
+	int nll;
+	struct {
+		struct nlmsghdr nl;
+		struct ndmsg rt;
+		char buf[8192];
+	} req;
+
+	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	if (sock < 0) {
+		printf("open netlink socket: %s\n", strerror(errno));
+		return -1;
+	}
+	memset(&sa, 0, sizeof(sa));
+	sa.nl_family = AF_NETLINK;
+	if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
+		printf("bind to netlink: %s\n", strerror(errno));
+		ret = -1;
+		goto cleanup;
+	}
+	memset(&req, 0, sizeof(req));
+	req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
+	req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
+	req.nl.nlmsg_type = RTM_GETNEIGH;
+	req.rt.ndm_state = NUD_REACHABLE;
+	req.rt.ndm_family = rtm_family;
+	req.nl.nlmsg_pid = 0;
+	req.nl.nlmsg_seq = ++seq;
+	memset(&msg, 0, sizeof(msg));
+	iov.iov_base = (void *)&req.nl;
+	iov.iov_len = req.nl.nlmsg_len;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	ret = sendmsg(sock, &msg, 0);
+	if (ret < 0) {
+		printf("send to netlink: %s\n", strerror(errno));
+		ret = -1;
+		goto cleanup;
+	}
+	memset(buf, 0, sizeof(buf));
+	nll = recv_msg(sa, sock);
+	if (nll < 0) {
+		printf("recv from netlink: %s\n", strerror(nll));
+		ret = -1;
+		goto cleanup;
+	}
+	nh = (struct nlmsghdr *)buf;
+	read_arp(nh, nll);
+cleanup:
+	close(sock);
+	return ret;
+}
+
+/* Function to keep track and update changes in route and arp table
+ * Give regular statistics of packets forwarded
+ */
+static int monitor_route(void)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	const unsigned int nr_keys = 256;
+	struct pollfd fds_route, fds_arp;
+	__u64 prev[nr_keys][nr_cpus];
+	struct sockaddr_nl la, lr;
+	__u64 values[nr_cpus];
+	struct nlmsghdr *nh;
+	int nll, ret = 0;
+	int interval = 5;
+	__u32 key;
+	int i;
+
+	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	if (sock < 0) {
+		printf("open netlink socket: %s\n", strerror(errno));
+		return -1;
+	}
+
+	fcntl(sock, F_SETFL, O_NONBLOCK);
+	memset(&lr, 0, sizeof(lr));
+	lr.nl_family = AF_NETLINK;
+	lr.nl_groups = RTMGRP_IPV6_ROUTE | RTMGRP_IPV4_ROUTE | RTMGRP_NOTIFY;
+	if (bind(sock, (struct sockaddr *)&lr, sizeof(lr)) < 0) {
+		printf("bind to netlink: %s\n", strerror(errno));
+		ret = -1;
+		goto cleanup;
+	}
+	fds_route.fd = sock;
+	fds_route.events = POLL_IN;
+
+	sock_arp = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	if (sock_arp < 0) {
+		printf("open netlink socket: %s\n", strerror(errno));
+		return -1;
+	}
+
+	fcntl(sock_arp, F_SETFL, O_NONBLOCK);
+	memset(&la, 0, sizeof(la));
+	la.nl_family = AF_NETLINK;
+	la.nl_groups = RTMGRP_NEIGH | RTMGRP_NOTIFY;
+	if (bind(sock_arp, (struct sockaddr *)&la, sizeof(la)) < 0) {
+		printf("bind to netlink: %s\n", strerror(errno));
+		ret = -1;
+		goto cleanup;
+	}
+	fds_arp.fd = sock_arp;
+	fds_arp.events = POLL_IN;
+
+	memset(prev, 0, sizeof(prev));
+	do {
+		signal(SIGINT, close_and_exit);
+		signal(SIGTERM, close_and_exit);
+
+		sleep(interval);
+		for (key = 0; key < nr_keys; key++) {
+			__u64 sum = 0;
+
+			assert(bpf_map_lookup_elem(rxcnt_map_fd,
+						   &key, values) == 0);
+			for (i = 0; i < nr_cpus; i++)
+				sum += (values[i] - prev[key][i]);
+			if (sum)
+				printf("proto %u: %10llu pkt/s\n",
+				       key, sum / interval);
+			memcpy(prev[key], values, sizeof(values));
+		}
+
+		memset(buf, 0, sizeof(buf));
+		if (poll(&fds_route, 1, 3) == POLL_IN) {
+			nll = recv_msg(lr, sock);
+			if (nll < 0) {
+				printf("recv from netlink: %s\n", strerror(nll));
+				ret = -1;
+				goto cleanup;
+			}
+
+			nh = (struct nlmsghdr *)buf;
+			printf("Routing table updated.\n");
+			read_route(nh, nll);
+		}
+		memset(buf, 0, sizeof(buf));
+		if (poll(&fds_arp, 1, 3) == POLL_IN) {
+			nll = recv_msg(la, sock_arp);
+			if (nll < 0) {
+				printf("recv from netlink: %s\n", strerror(nll));
+				ret = -1;
+				goto cleanup;
+			}
+
+			nh = (struct nlmsghdr *)buf;
+			read_arp(nh, nll);
+		}
+
+	} while (1);
+cleanup:
+	close(sock);
+	return ret;
+}
+
+static void usage(const char *prog)
+{
+	fprintf(stderr,
+		"%s: %s [OPTS] interface name list\n\n"
+		"OPTS:\n"
+		"    -S    use skb-mode\n"
+		"    -F    force loading prog\n",
+		__func__, prog);
+}
+
+int main(int ac, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type	= BPF_PROG_TYPE_XDP,
+	};
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	const char *optstr = "SF";
+	struct bpf_object *obj;
+	char filename[256];
+	char **ifname_list;
+	int prog_fd, opt;
+	int err, i = 1;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	prog_load_attr.file = filename;
+
+	total_ifindex = ac - 1;
+	ifname_list = (argv + 1);
+
+	while ((opt = getopt(ac, argv, optstr)) != -1) {
+		switch (opt) {
+		case 'S':
+			flags |= XDP_FLAGS_SKB_MODE;
+			total_ifindex--;
+			ifname_list++;
+			break;
+		case 'F':
+			flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			total_ifindex--;
+			ifname_list++;
+			break;
+		default:
+			usage(basename(argv[0]));
+			return 1;
+		}
+	}
+
+	if (!(flags & XDP_FLAGS_SKB_MODE))
+		flags |= XDP_FLAGS_DRV_MODE;
+
+	if (optind == ac) {
+		usage(basename(argv[0]));
+		return 1;
+	}
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+		return 1;
+
+	printf("\n**************loading bpf file*********************\n\n\n");
+	if (!prog_fd) {
+		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
+		return 1;
+	}
+
+	lpm_map_fd = bpf_object__find_map_fd_by_name(obj, "lpm_map");
+	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
+	arp_table_map_fd = bpf_object__find_map_fd_by_name(obj, "arp_table");
+	exact_match_map_fd = bpf_object__find_map_fd_by_name(obj,
+							     "exact_match");
+	tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port");
+	if (lpm_map_fd < 0 || rxcnt_map_fd < 0 || arp_table_map_fd < 0 ||
+	    exact_match_map_fd < 0 || tx_port_map_fd < 0) {
+		printf("bpf_object__find_map_fd_by_name failed\n");
+		return 1;
+	}
+
+	ifindex_list = (int *)calloc(total_ifindex, sizeof(int *));
+	for (i = 0; i < total_ifindex; i++) {
+		ifindex_list[i] = if_nametoindex(ifname_list[i]);
+		if (!ifindex_list[i]) {
+			printf("Couldn't translate interface name: %s",
+			       strerror(errno));
+			return 1;
+		}
+	}
+	prog_id_list = (__u32 *)calloc(total_ifindex, sizeof(__u32 *));
+	for (i = 0; i < total_ifindex; i++) {
+		if (bpf_set_link_xdp_fd(ifindex_list[i], prog_fd, flags) < 0) {
+			printf("link set xdp fd failed\n");
+			int recovery_index = i;
+
+			for (i = 0; i < recovery_index; i++)
+				bpf_set_link_xdp_fd(ifindex_list[i], -1, flags);
+
+			return 1;
+		}
+		err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
+		if (err) {
+			printf("can't get prog info - %s\n", strerror(errno));
+			return err;
+		}
+		prog_id_list[i] = info.id;
+		memset(&info, 0, sizeof(info));
+		printf("Attached to %d\n", ifindex_list[i]);
+	}
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	printf("*******************ROUTE TABLE*************************\n\n\n");
+	get_route_table(AF_INET);
+	printf("*******************ARP TABLE***************************\n\n\n");
+	get_arp_table(AF_INET);
+	if (monitor_route() < 0) {
+		printf("Error in receiving route update");
+		return 1;
+	}
+
+	return 0;
+}
diff --git a/samples/bpf/xdp_rxq_info_kern.c b/samples/bpf/xdp_rxq_info_kern.c
new file mode 100644
index 000000000..5e7459f9b
--- /dev/null
+++ b/samples/bpf/xdp_rxq_info_kern.c
@@ -0,0 +1,140 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
+ *
+ *  Example howto extract XDP RX-queue info
+ */
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/in.h>
+#include <bpf/bpf_helpers.h>
+
+/* Config setup from with userspace
+ *
+ * User-side setup ifindex in config_map, to verify that
+ * ctx->ingress_ifindex is correct (against configured ifindex)
+ */
+struct config {
+	__u32 action;
+	int ifindex;
+	__u32 options;
+};
+enum cfg_options_flags {
+	NO_TOUCH = 0x0U,
+	READ_MEM = 0x1U,
+	SWAP_MAC = 0x2U,
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, int);
+	__type(value, struct config);
+	__uint(max_entries, 1);
+} config_map SEC(".maps");
+
+/* Common stats data record (shared with userspace) */
+struct datarec {
+	__u64 processed;
+	__u64 issue;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, struct datarec);
+	__uint(max_entries, 1);
+} stats_global_map SEC(".maps");
+
+#define MAX_RXQs 64
+
+/* Stats per rx_queue_index (per CPU) */
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, struct datarec);
+	__uint(max_entries, MAX_RXQs + 1);
+} rx_queue_index_map SEC(".maps");
+
+static __always_inline
+void swap_src_dst_mac(void *data)
+{
+	unsigned short *p = data;
+	unsigned short dst[3];
+
+	dst[0] = p[0];
+	dst[1] = p[1];
+	dst[2] = p[2];
+	p[0] = p[3];
+	p[1] = p[4];
+	p[2] = p[5];
+	p[3] = dst[0];
+	p[4] = dst[1];
+	p[5] = dst[2];
+}
+
+SEC("xdp_prog0")
+int  xdp_prognum0(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data     = (void *)(long)ctx->data;
+	struct datarec *rec, *rxq_rec;
+	int ingress_ifindex;
+	struct config *config;
+	u32 key = 0;
+
+	/* Global stats record */
+	rec = bpf_map_lookup_elem(&stats_global_map, &key);
+	if (!rec)
+		return XDP_ABORTED;
+	rec->processed++;
+
+	/* Accessing ctx->ingress_ifindex, cause BPF to rewrite BPF
+	 * instructions inside kernel to access xdp_rxq->dev->ifindex
+	 */
+	ingress_ifindex = ctx->ingress_ifindex;
+
+	config = bpf_map_lookup_elem(&config_map, &key);
+	if (!config)
+		return XDP_ABORTED;
+
+	/* Simple test: check ctx provided ifindex is as expected */
+	if (ingress_ifindex != config->ifindex) {
+		/* count this error case */
+		rec->issue++;
+		return XDP_ABORTED;
+	}
+
+	/* Update stats per rx_queue_index. Handle if rx_queue_index
+	 * is larger than stats map can contain info for.
+	 */
+	key = ctx->rx_queue_index;
+	if (key >= MAX_RXQs)
+		key = MAX_RXQs;
+	rxq_rec = bpf_map_lookup_elem(&rx_queue_index_map, &key);
+	if (!rxq_rec)
+		return XDP_ABORTED;
+	rxq_rec->processed++;
+	if (key == MAX_RXQs)
+		rxq_rec->issue++;
+
+	/* Default: Don't touch packet data, only count packets */
+	if (unlikely(config->options & (READ_MEM|SWAP_MAC))) {
+		struct ethhdr *eth = data;
+
+		if (eth + 1 > data_end)
+			return XDP_ABORTED;
+
+		/* Avoid compiler removing this: Drop non 802.3 Ethertypes */
+		if (ntohs(eth->h_proto) < ETH_P_802_3_MIN)
+			return XDP_ABORTED;
+
+		/* XDP_TX requires changing MAC-addrs, else HW may drop.
+		 * Can also be enabled with --swapmac (for test purposes)
+		 */
+		if (unlikely(config->options & SWAP_MAC))
+			swap_src_dst_mac(data);
+	}
+
+	return config->action;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp_rxq_info_user.c b/samples/bpf/xdp_rxq_info_user.c
new file mode 100644
index 000000000..93fa1bc54
--- /dev/null
+++ b/samples/bpf/xdp_rxq_info_user.c
@@ -0,0 +1,605 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
+ */
+static const char *__doc__ = " XDP RX-queue info extract example\n\n"
+	"Monitor how many packets per sec (pps) are received\n"
+	"per NIC RX queue index and which CPU processed the packet\n"
+	;
+
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <locale.h>
+#include <sys/resource.h>
+#include <getopt.h>
+#include <net/if.h>
+#include <time.h>
+
+#include <arpa/inet.h>
+#include <linux/if_link.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "bpf_util.h"
+
+static int ifindex = -1;
+static char ifname_buf[IF_NAMESIZE];
+static char *ifname;
+static __u32 prog_id;
+
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+
+static struct bpf_map *stats_global_map;
+static struct bpf_map *rx_queue_index_map;
+
+/* Exit return codes */
+#define EXIT_OK		0
+#define EXIT_FAIL		1
+#define EXIT_FAIL_OPTION	2
+#define EXIT_FAIL_XDP		3
+#define EXIT_FAIL_BPF		4
+#define EXIT_FAIL_MEM		5
+
+static const struct option long_options[] = {
+	{"help",	no_argument,		NULL, 'h' },
+	{"dev",		required_argument,	NULL, 'd' },
+	{"skb-mode",	no_argument,		NULL, 'S' },
+	{"sec",		required_argument,	NULL, 's' },
+	{"no-separators", no_argument,		NULL, 'z' },
+	{"action",	required_argument,	NULL, 'a' },
+	{"readmem",	no_argument,		NULL, 'r' },
+	{"swapmac",	no_argument,		NULL, 'm' },
+	{"force",	no_argument,		NULL, 'F' },
+	{0, 0, NULL,  0 }
+};
+
+static void int_exit(int sig)
+{
+	__u32 curr_prog_id = 0;
+
+	if (ifindex > -1) {
+		if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
+			printf("bpf_get_link_xdp_id failed\n");
+			exit(EXIT_FAIL);
+		}
+		if (prog_id == curr_prog_id) {
+			fprintf(stderr,
+				"Interrupted: Removing XDP program on ifindex:%d device:%s\n",
+				ifindex, ifname);
+			bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
+		} else if (!curr_prog_id) {
+			printf("couldn't find a prog id on a given iface\n");
+		} else {
+			printf("program on interface changed, not removing\n");
+		}
+	}
+	exit(EXIT_OK);
+}
+
+struct config {
+	__u32 action;
+	int ifindex;
+	__u32 options;
+};
+enum cfg_options_flags {
+	NO_TOUCH = 0x0U,
+	READ_MEM = 0x1U,
+	SWAP_MAC = 0x2U,
+};
+#define XDP_ACTION_MAX (XDP_TX + 1)
+#define XDP_ACTION_MAX_STRLEN 11
+static const char *xdp_action_names[XDP_ACTION_MAX] = {
+	[XDP_ABORTED]	= "XDP_ABORTED",
+	[XDP_DROP]	= "XDP_DROP",
+	[XDP_PASS]	= "XDP_PASS",
+	[XDP_TX]	= "XDP_TX",
+};
+
+static const char *action2str(int action)
+{
+	if (action < XDP_ACTION_MAX)
+		return xdp_action_names[action];
+	return NULL;
+}
+
+static int parse_xdp_action(char *action_str)
+{
+	size_t maxlen;
+	__u64 action = -1;
+	int i;
+
+	for (i = 0; i < XDP_ACTION_MAX; i++) {
+		maxlen = XDP_ACTION_MAX_STRLEN;
+		if (strncmp(xdp_action_names[i], action_str, maxlen) == 0) {
+			action = i;
+			break;
+		}
+	}
+	return action;
+}
+
+static void list_xdp_actions(void)
+{
+	int i;
+
+	printf("Available XDP --action <options>\n");
+	for (i = 0; i < XDP_ACTION_MAX; i++)
+		printf("\t%s\n", xdp_action_names[i]);
+	printf("\n");
+}
+
+static char* options2str(enum cfg_options_flags flag)
+{
+	if (flag == NO_TOUCH)
+		return "no_touch";
+	if (flag & SWAP_MAC)
+		return "swapmac";
+	if (flag & READ_MEM)
+		return "read";
+	fprintf(stderr, "ERR: Unknown config option flags");
+	exit(EXIT_FAIL);
+}
+
+static void usage(char *argv[])
+{
+	int i;
+
+	printf("\nDOCUMENTATION:\n%s\n", __doc__);
+	printf(" Usage: %s (options-see-below)\n", argv[0]);
+	printf(" Listing options:\n");
+	for (i = 0; long_options[i].name != 0; i++) {
+		printf(" --%-12s", long_options[i].name);
+		if (long_options[i].flag != NULL)
+			printf(" flag (internal value:%d)",
+				*long_options[i].flag);
+		else
+			printf(" short-option: -%c",
+				long_options[i].val);
+		printf("\n");
+	}
+	printf("\n");
+	list_xdp_actions();
+}
+
+#define NANOSEC_PER_SEC 1000000000 /* 10^9 */
+static __u64 gettime(void)
+{
+	struct timespec t;
+	int res;
+
+	res = clock_gettime(CLOCK_MONOTONIC, &t);
+	if (res < 0) {
+		fprintf(stderr, "Error with gettimeofday! (%i)\n", res);
+		exit(EXIT_FAIL);
+	}
+	return (__u64) t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec;
+}
+
+/* Common stats data record shared with _kern.c */
+struct datarec {
+	__u64 processed;
+	__u64 issue;
+};
+struct record {
+	__u64 timestamp;
+	struct datarec total;
+	struct datarec *cpu;
+};
+struct stats_record {
+	struct record stats;
+	struct record *rxq;
+};
+
+static struct datarec *alloc_record_per_cpu(void)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	struct datarec *array;
+
+	array = calloc(nr_cpus, sizeof(struct datarec));
+	if (!array) {
+		fprintf(stderr, "Mem alloc error (nr_cpus:%u)\n", nr_cpus);
+		exit(EXIT_FAIL_MEM);
+	}
+	return array;
+}
+
+static struct record *alloc_record_per_rxq(void)
+{
+	unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
+	struct record *array;
+
+	array = calloc(nr_rxqs, sizeof(struct record));
+	if (!array) {
+		fprintf(stderr, "Mem alloc error (nr_rxqs:%u)\n", nr_rxqs);
+		exit(EXIT_FAIL_MEM);
+	}
+	return array;
+}
+
+static struct stats_record *alloc_stats_record(void)
+{
+	unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
+	struct stats_record *rec;
+	int i;
+
+	rec = calloc(1, sizeof(struct stats_record));
+	if (!rec) {
+		fprintf(stderr, "Mem alloc error\n");
+		exit(EXIT_FAIL_MEM);
+	}
+	rec->rxq = alloc_record_per_rxq();
+	for (i = 0; i < nr_rxqs; i++)
+		rec->rxq[i].cpu = alloc_record_per_cpu();
+
+	rec->stats.cpu = alloc_record_per_cpu();
+	return rec;
+}
+
+static void free_stats_record(struct stats_record *r)
+{
+	unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
+	int i;
+
+	for (i = 0; i < nr_rxqs; i++)
+		free(r->rxq[i].cpu);
+
+	free(r->rxq);
+	free(r->stats.cpu);
+	free(r);
+}
+
+static bool map_collect_percpu(int fd, __u32 key, struct record *rec)
+{
+	/* For percpu maps, userspace gets a value per possible CPU */
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	struct datarec values[nr_cpus];
+	__u64 sum_processed = 0;
+	__u64 sum_issue = 0;
+	int i;
+
+	if ((bpf_map_lookup_elem(fd, &key, values)) != 0) {
+		fprintf(stderr,
+			"ERR: bpf_map_lookup_elem failed key:0x%X\n", key);
+		return false;
+	}
+	/* Get time as close as possible to reading map contents */
+	rec->timestamp = gettime();
+
+	/* Record and sum values from each CPU */
+	for (i = 0; i < nr_cpus; i++) {
+		rec->cpu[i].processed = values[i].processed;
+		sum_processed        += values[i].processed;
+		rec->cpu[i].issue = values[i].issue;
+		sum_issue        += values[i].issue;
+	}
+	rec->total.processed = sum_processed;
+	rec->total.issue     = sum_issue;
+	return true;
+}
+
+static void stats_collect(struct stats_record *rec)
+{
+	int fd, i, max_rxqs;
+
+	fd = bpf_map__fd(stats_global_map);
+	map_collect_percpu(fd, 0, &rec->stats);
+
+	fd = bpf_map__fd(rx_queue_index_map);
+	max_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
+	for (i = 0; i < max_rxqs; i++)
+		map_collect_percpu(fd, i, &rec->rxq[i]);
+}
+
+static double calc_period(struct record *r, struct record *p)
+{
+	double period_ = 0;
+	__u64 period = 0;
+
+	period = r->timestamp - p->timestamp;
+	if (period > 0)
+		period_ = ((double) period / NANOSEC_PER_SEC);
+
+	return period_;
+}
+
+static __u64 calc_pps(struct datarec *r, struct datarec *p, double period_)
+{
+	__u64 packets = 0;
+	__u64 pps = 0;
+
+	if (period_ > 0) {
+		packets = r->processed - p->processed;
+		pps = packets / period_;
+	}
+	return pps;
+}
+
+static __u64 calc_errs_pps(struct datarec *r,
+			    struct datarec *p, double period_)
+{
+	__u64 packets = 0;
+	__u64 pps = 0;
+
+	if (period_ > 0) {
+		packets = r->issue - p->issue;
+		pps = packets / period_;
+	}
+	return pps;
+}
+
+static void stats_print(struct stats_record *stats_rec,
+			struct stats_record *stats_prev,
+			int action, __u32 cfg_opt)
+{
+	unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries;
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	double pps = 0, err = 0;
+	struct record *rec, *prev;
+	double t;
+	int rxq;
+	int i;
+
+	/* Header */
+	printf("\nRunning XDP on dev:%s (ifindex:%d) action:%s options:%s\n",
+	       ifname, ifindex, action2str(action), options2str(cfg_opt));
+
+	/* stats_global_map */
+	{
+		char *fmt_rx = "%-15s %-7d %'-11.0f %'-10.0f %s\n";
+		char *fm2_rx = "%-15s %-7s %'-11.0f\n";
+		char *errstr = "";
+
+		printf("%-15s %-7s %-11s %-11s\n",
+		       "XDP stats", "CPU", "pps", "issue-pps");
+
+		rec  =  &stats_rec->stats;
+		prev = &stats_prev->stats;
+		t = calc_period(rec, prev);
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+
+			pps = calc_pps     (r, p, t);
+			err = calc_errs_pps(r, p, t);
+			if (err > 0)
+				errstr = "invalid-ifindex";
+			if (pps > 0)
+				printf(fmt_rx, "XDP-RX CPU",
+					i, pps, err, errstr);
+		}
+		pps  = calc_pps     (&rec->total, &prev->total, t);
+		err  = calc_errs_pps(&rec->total, &prev->total, t);
+		printf(fm2_rx, "XDP-RX CPU", "total", pps, err);
+	}
+
+	/* rx_queue_index_map */
+	printf("\n%-15s %-7s %-11s %-11s\n",
+	       "RXQ stats", "RXQ:CPU", "pps", "issue-pps");
+
+	for (rxq = 0; rxq < nr_rxqs; rxq++) {
+		char *fmt_rx = "%-15s %3d:%-3d %'-11.0f %'-10.0f %s\n";
+		char *fm2_rx = "%-15s %3d:%-3s %'-11.0f\n";
+		char *errstr = "";
+		int rxq_ = rxq;
+
+		/* Last RXQ in map catch overflows */
+		if (rxq_ == nr_rxqs - 1)
+			rxq_ = -1;
+
+		rec  =  &stats_rec->rxq[rxq];
+		prev = &stats_prev->rxq[rxq];
+		t = calc_period(rec, prev);
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+
+			pps = calc_pps     (r, p, t);
+			err = calc_errs_pps(r, p, t);
+			if (err > 0) {
+				if (rxq_ == -1)
+					errstr = "map-overflow-RXQ";
+				else
+					errstr = "err";
+			}
+			if (pps > 0)
+				printf(fmt_rx, "rx_queue_index",
+				       rxq_, i, pps, err, errstr);
+		}
+		pps  = calc_pps     (&rec->total, &prev->total, t);
+		err  = calc_errs_pps(&rec->total, &prev->total, t);
+		if (pps || err)
+			printf(fm2_rx, "rx_queue_index", rxq_, "sum", pps, err);
+	}
+}
+
+
+/* Pointer swap trick */
+static inline void swap(struct stats_record **a, struct stats_record **b)
+{
+	struct stats_record *tmp;
+
+	tmp = *a;
+	*a = *b;
+	*b = tmp;
+}
+
+static void stats_poll(int interval, int action, __u32 cfg_opt)
+{
+	struct stats_record *record, *prev;
+
+	record = alloc_stats_record();
+	prev   = alloc_stats_record();
+	stats_collect(record);
+
+	while (1) {
+		swap(&prev, &record);
+		stats_collect(record);
+		stats_print(record, prev, action, cfg_opt);
+		sleep(interval);
+	}
+
+	free_stats_record(record);
+	free_stats_record(prev);
+}
+
+
+int main(int argc, char **argv)
+{
+	__u32 cfg_options= NO_TOUCH ; /* Default: Don't touch packet memory */
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type	= BPF_PROG_TYPE_XDP,
+	};
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	int prog_fd, map_fd, opt, err;
+	bool use_separators = true;
+	struct config cfg = { 0 };
+	struct bpf_object *obj;
+	struct bpf_map *map;
+	char filename[256];
+	int longindex = 0;
+	int interval = 2;
+	__u32 key = 0;
+
+
+	char action_str_buf[XDP_ACTION_MAX_STRLEN + 1 /* for \0 */] = { 0 };
+	int action = XDP_PASS; /* Default action */
+	char *action_str = NULL;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	prog_load_attr.file = filename;
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+		return EXIT_FAIL;
+
+	map =  bpf_object__find_map_by_name(obj, "config_map");
+	stats_global_map = bpf_object__find_map_by_name(obj, "stats_global_map");
+	rx_queue_index_map = bpf_object__find_map_by_name(obj, "rx_queue_index_map");
+	if (!map || !stats_global_map || !rx_queue_index_map) {
+		printf("finding a map in obj file failed\n");
+		return EXIT_FAIL;
+	}
+	map_fd = bpf_map__fd(map);
+
+	if (!prog_fd) {
+		fprintf(stderr, "ERR: bpf_prog_load_xattr: %s\n", strerror(errno));
+		return EXIT_FAIL;
+	}
+
+	/* Parse commands line args */
+	while ((opt = getopt_long(argc, argv, "FhSrmzd:s:a:",
+				  long_options, &longindex)) != -1) {
+		switch (opt) {
+		case 'd':
+			if (strlen(optarg) >= IF_NAMESIZE) {
+				fprintf(stderr, "ERR: --dev name too long\n");
+				goto error;
+			}
+			ifname = (char *)&ifname_buf;
+			strncpy(ifname, optarg, IF_NAMESIZE);
+			ifindex = if_nametoindex(ifname);
+			if (ifindex == 0) {
+				fprintf(stderr,
+					"ERR: --dev name unknown err(%d):%s\n",
+					errno, strerror(errno));
+				goto error;
+			}
+			break;
+		case 's':
+			interval = atoi(optarg);
+			break;
+		case 'S':
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
+			break;
+		case 'z':
+			use_separators = false;
+			break;
+		case 'a':
+			action_str = (char *)&action_str_buf;
+			strncpy(action_str, optarg, XDP_ACTION_MAX_STRLEN);
+			break;
+		case 'r':
+			cfg_options |= READ_MEM;
+			break;
+		case 'm':
+			cfg_options |= SWAP_MAC;
+			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		case 'h':
+		error:
+		default:
+			usage(argv);
+			return EXIT_FAIL_OPTION;
+		}
+	}
+
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	/* Required option */
+	if (ifindex == -1) {
+		fprintf(stderr, "ERR: required option --dev missing\n");
+		usage(argv);
+		return EXIT_FAIL_OPTION;
+	}
+	cfg.ifindex = ifindex;
+
+	/* Parse action string */
+	if (action_str) {
+		action = parse_xdp_action(action_str);
+		if (action < 0) {
+			fprintf(stderr, "ERR: Invalid XDP --action: %s\n",
+				action_str);
+			list_xdp_actions();
+			return EXIT_FAIL_OPTION;
+		}
+	}
+	cfg.action = action;
+
+	/* XDP_TX requires changing MAC-addrs, else HW may drop */
+	if (action == XDP_TX)
+		cfg_options |= SWAP_MAC;
+	cfg.options = cfg_options;
+
+	/* Trick to pretty printf with thousands separators use %' */
+	if (use_separators)
+		setlocale(LC_NUMERIC, "en_US");
+
+	/* User-side setup ifindex in config_map */
+	err = bpf_map_update_elem(map_fd, &key, &cfg, 0);
+	if (err) {
+		fprintf(stderr, "Store config failed (err:%d)\n", err);
+		exit(EXIT_FAIL_BPF);
+	}
+
+	/* Remove XDP program when program is interrupted or killed */
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
+		fprintf(stderr, "link set xdp fd failed\n");
+		return EXIT_FAIL_XDP;
+	}
+
+	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
+	if (err) {
+		printf("can't get prog info - %s\n", strerror(errno));
+		return err;
+	}
+	prog_id = info.id;
+
+	stats_poll(interval, action, cfg_options);
+	return EXIT_OK;
+}
diff --git a/samples/bpf/xdp_sample_pkts_kern.c b/samples/bpf/xdp_sample_pkts_kern.c
new file mode 100644
index 000000000..9cf76b340
--- /dev/null
+++ b/samples/bpf/xdp_sample_pkts_kern.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ptrace.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+#define SAMPLE_SIZE 64ul
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(u32));
+} my_map SEC(".maps");
+
+SEC("xdp_sample")
+int xdp_sample_prog(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+
+	/* Metadata will be in the perf event before the packet data. */
+	struct S {
+		u16 cookie;
+		u16 pkt_len;
+	} __packed metadata;
+
+	if (data < data_end) {
+		/* The XDP perf_event_output handler will use the upper 32 bits
+		 * of the flags argument as a number of bytes to include of the
+		 * packet payload in the event data. If the size is too big, the
+		 * call to bpf_perf_event_output will fail and return -EFAULT.
+		 *
+		 * See bpf_xdp_event_output in net/core/filter.c.
+		 *
+		 * The BPF_F_CURRENT_CPU flag means that the event output fd
+		 * will be indexed by the CPU number in the event map.
+		 */
+		u64 flags = BPF_F_CURRENT_CPU;
+		u16 sample_size;
+		int ret;
+
+		metadata.cookie = 0xdead;
+		metadata.pkt_len = (u16)(data_end - data);
+		sample_size = min(metadata.pkt_len, SAMPLE_SIZE);
+		flags |= (u64)sample_size << 32;
+
+		ret = bpf_perf_event_output(ctx, &my_map, flags,
+					    &metadata, sizeof(metadata));
+		if (ret)
+			bpf_printk("perf_event_output failed: %d\n", ret);
+	}
+
+	return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/xdp_sample_pkts_user.c b/samples/bpf/xdp_sample_pkts_user.c
new file mode 100644
index 000000000..4b2a300c7
--- /dev/null
+++ b/samples/bpf/xdp_sample_pkts_user.c
@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <linux/perf_event.h>
+#include <linux/bpf.h>
+#include <net/if.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/sysinfo.h>
+#include <sys/ioctl.h>
+#include <signal.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include <sys/resource.h>
+#include <libgen.h>
+#include <linux/if_link.h>
+
+#include "perf-sys.h"
+
+static int if_idx;
+static char *if_name;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static __u32 prog_id;
+static struct perf_buffer *pb = NULL;
+
+static int do_attach(int idx, int fd, const char *name)
+{
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	int err;
+
+	err = bpf_set_link_xdp_fd(idx, fd, xdp_flags);
+	if (err < 0) {
+		printf("ERROR: failed to attach program to %s\n", name);
+		return err;
+	}
+
+	err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
+	if (err) {
+		printf("can't get prog info - %s\n", strerror(errno));
+		return err;
+	}
+	prog_id = info.id;
+
+	return err;
+}
+
+static int do_detach(int idx, const char *name)
+{
+	__u32 curr_prog_id = 0;
+	int err = 0;
+
+	err = bpf_get_link_xdp_id(idx, &curr_prog_id, xdp_flags);
+	if (err) {
+		printf("bpf_get_link_xdp_id failed\n");
+		return err;
+	}
+	if (prog_id == curr_prog_id) {
+		err = bpf_set_link_xdp_fd(idx, -1, xdp_flags);
+		if (err < 0)
+			printf("ERROR: failed to detach prog from %s\n", name);
+	} else if (!curr_prog_id) {
+		printf("couldn't find a prog id on a %s\n", name);
+	} else {
+		printf("program on interface changed, not removing\n");
+	}
+
+	return err;
+}
+
+#define SAMPLE_SIZE 64
+
+static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
+{
+	struct {
+		__u16 cookie;
+		__u16 pkt_len;
+		__u8  pkt_data[SAMPLE_SIZE];
+	} __packed *e = data;
+	int i;
+
+	if (e->cookie != 0xdead) {
+		printf("BUG cookie %x sized %d\n", e->cookie, size);
+		return;
+	}
+
+	printf("Pkt len: %-5d bytes. Ethernet hdr: ", e->pkt_len);
+	for (i = 0; i < 14 && i < e->pkt_len; i++)
+		printf("%02x ", e->pkt_data[i]);
+	printf("\n");
+}
+
+static void sig_handler(int signo)
+{
+	do_detach(if_idx, if_name);
+	perf_buffer__free(pb);
+	exit(0);
+}
+
+static void usage(const char *prog)
+{
+	fprintf(stderr,
+		"%s: %s [OPTS] <ifname|ifindex>\n\n"
+		"OPTS:\n"
+		"    -F    force loading prog\n",
+		__func__, prog);
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type	= BPF_PROG_TYPE_XDP,
+	};
+	struct perf_buffer_opts pb_opts = {};
+	const char *optstr = "FS";
+	int prog_fd, map_fd, opt;
+	struct bpf_object *obj;
+	struct bpf_map *map;
+	char filename[256];
+	int ret, err;
+
+	while ((opt = getopt(argc, argv, optstr)) != -1) {
+		switch (opt) {
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		case 'S':
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
+			break;
+		default:
+			usage(basename(argv[0]));
+			return 1;
+		}
+	}
+
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	if (optind == argc) {
+		usage(basename(argv[0]));
+		return 1;
+	}
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	prog_load_attr.file = filename;
+
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+		return 1;
+
+	if (!prog_fd) {
+		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
+		return 1;
+	}
+
+	map = bpf_map__next(NULL, obj);
+	if (!map) {
+		printf("finding a map in obj file failed\n");
+		return 1;
+	}
+	map_fd = bpf_map__fd(map);
+
+	if_idx = if_nametoindex(argv[optind]);
+	if (!if_idx)
+		if_idx = strtoul(argv[optind], NULL, 0);
+
+	if (!if_idx) {
+		fprintf(stderr, "Invalid ifname\n");
+		return 1;
+	}
+	if_name = argv[optind];
+	err = do_attach(if_idx, prog_fd, if_name);
+	if (err)
+		return err;
+
+	if (signal(SIGINT, sig_handler) ||
+	    signal(SIGHUP, sig_handler) ||
+	    signal(SIGTERM, sig_handler)) {
+		perror("signal");
+		return 1;
+	}
+
+	pb_opts.sample_cb = print_bpf_output;
+	pb = perf_buffer__new(map_fd, 8, &pb_opts);
+	err = libbpf_get_error(pb);
+	if (err) {
+		perror("perf_buffer setup failed");
+		return 1;
+	}
+
+	while ((ret = perf_buffer__poll(pb, 1000)) >= 0) {
+	}
+
+	kill(0, SIGINT);
+	return ret;
+}
diff --git a/samples/bpf/xdp_tx_iptunnel_common.h b/samples/bpf/xdp_tx_iptunnel_common.h
new file mode 100644
index 000000000..be839892c
--- /dev/null
+++ b/samples/bpf/xdp_tx_iptunnel_common.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2016 Facebook
+ */
+#ifndef _SAMPLES_BPF_XDP_TX_IPTNL_COMMON_H
+#define _SAMPLES_BPF_XDP_TX_IPTNL_COMMON_H
+
+#include <linux/types.h>
+
+#define MAX_IPTNL_ENTRIES 256U
+
+struct vip {
+	union {
+		__u32 v6[4];
+		__u32 v4;
+	} daddr;
+	__u16 dport;
+	__u16 family;
+	__u8 protocol;
+};
+
+struct iptnl_info {
+	union {
+		__u32 v6[4];
+		__u32 v4;
+	} saddr;
+	union {
+		__u32 v6[4];
+		__u32 v4;
+	} daddr;
+	__u16 family;
+	__u8 dmac[6];
+};
+
+#endif
diff --git a/samples/bpf/xdp_tx_iptunnel_kern.c b/samples/bpf/xdp_tx_iptunnel_kern.c
new file mode 100644
index 000000000..575d57e4b
--- /dev/null
+++ b/samples/bpf/xdp_tx_iptunnel_kern.c
@@ -0,0 +1,237 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program shows how to use bpf_xdp_adjust_head() by
+ * encapsulating the incoming packet in an IPv4/v6 header
+ * and then XDP_TX it out.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <bpf/bpf_helpers.h>
+#include "xdp_tx_iptunnel_common.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, __u32);
+	__type(value, __u64);
+	__uint(max_entries, 256);
+} rxcnt SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, struct vip);
+	__type(value, struct iptnl_info);
+	__uint(max_entries, MAX_IPTNL_ENTRIES);
+} vip2tnl SEC(".maps");
+
+static __always_inline void count_tx(u32 protocol)
+{
+	u64 *rxcnt_count;
+
+	rxcnt_count = bpf_map_lookup_elem(&rxcnt, &protocol);
+	if (rxcnt_count)
+		*rxcnt_count += 1;
+}
+
+static __always_inline int get_dport(void *trans_data, void *data_end,
+				     u8 protocol)
+{
+	struct tcphdr *th;
+	struct udphdr *uh;
+
+	switch (protocol) {
+	case IPPROTO_TCP:
+		th = (struct tcphdr *)trans_data;
+		if (th + 1 > data_end)
+			return -1;
+		return th->dest;
+	case IPPROTO_UDP:
+		uh = (struct udphdr *)trans_data;
+		if (uh + 1 > data_end)
+			return -1;
+		return uh->dest;
+	default:
+		return 0;
+	}
+}
+
+static __always_inline void set_ethhdr(struct ethhdr *new_eth,
+				       const struct ethhdr *old_eth,
+				       const struct iptnl_info *tnl,
+				       __be16 h_proto)
+{
+	memcpy(new_eth->h_source, old_eth->h_dest, sizeof(new_eth->h_source));
+	memcpy(new_eth->h_dest, tnl->dmac, sizeof(new_eth->h_dest));
+	new_eth->h_proto = h_proto;
+}
+
+static __always_inline int handle_ipv4(struct xdp_md *xdp)
+{
+	void *data_end = (void *)(long)xdp->data_end;
+	void *data = (void *)(long)xdp->data;
+	struct iptnl_info *tnl;
+	struct ethhdr *new_eth;
+	struct ethhdr *old_eth;
+	struct iphdr *iph = data + sizeof(struct ethhdr);
+	u16 *next_iph_u16;
+	u16 payload_len;
+	struct vip vip = {};
+	int dport;
+	u32 csum = 0;
+	int i;
+
+	if (iph + 1 > data_end)
+		return XDP_DROP;
+
+	dport = get_dport(iph + 1, data_end, iph->protocol);
+	if (dport == -1)
+		return XDP_DROP;
+
+	vip.protocol = iph->protocol;
+	vip.family = AF_INET;
+	vip.daddr.v4 = iph->daddr;
+	vip.dport = dport;
+	payload_len = ntohs(iph->tot_len);
+
+	tnl = bpf_map_lookup_elem(&vip2tnl, &vip);
+	/* It only does v4-in-v4 */
+	if (!tnl || tnl->family != AF_INET)
+		return XDP_PASS;
+
+	/* The vip key is found.  Add an IP header and send it out */
+
+	if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct iphdr)))
+		return XDP_DROP;
+
+	data = (void *)(long)xdp->data;
+	data_end = (void *)(long)xdp->data_end;
+
+	new_eth = data;
+	iph = data + sizeof(*new_eth);
+	old_eth = data + sizeof(*iph);
+
+	if (new_eth + 1 > data_end ||
+	    old_eth + 1 > data_end ||
+	    iph + 1 > data_end)
+		return XDP_DROP;
+
+	set_ethhdr(new_eth, old_eth, tnl, htons(ETH_P_IP));
+
+	iph->version = 4;
+	iph->ihl = sizeof(*iph) >> 2;
+	iph->frag_off =	0;
+	iph->protocol = IPPROTO_IPIP;
+	iph->check = 0;
+	iph->tos = 0;
+	iph->tot_len = htons(payload_len + sizeof(*iph));
+	iph->daddr = tnl->daddr.v4;
+	iph->saddr = tnl->saddr.v4;
+	iph->ttl = 8;
+
+	next_iph_u16 = (u16 *)iph;
+#pragma clang loop unroll(full)
+	for (i = 0; i < sizeof(*iph) >> 1; i++)
+		csum += *next_iph_u16++;
+
+	iph->check = ~((csum & 0xffff) + (csum >> 16));
+
+	count_tx(vip.protocol);
+
+	return XDP_TX;
+}
+
+static __always_inline int handle_ipv6(struct xdp_md *xdp)
+{
+	void *data_end = (void *)(long)xdp->data_end;
+	void *data = (void *)(long)xdp->data;
+	struct iptnl_info *tnl;
+	struct ethhdr *new_eth;
+	struct ethhdr *old_eth;
+	struct ipv6hdr *ip6h = data + sizeof(struct ethhdr);
+	__u16 payload_len;
+	struct vip vip = {};
+	int dport;
+
+	if (ip6h + 1 > data_end)
+		return XDP_DROP;
+
+	dport = get_dport(ip6h + 1, data_end, ip6h->nexthdr);
+	if (dport == -1)
+		return XDP_DROP;
+
+	vip.protocol = ip6h->nexthdr;
+	vip.family = AF_INET6;
+	memcpy(vip.daddr.v6, ip6h->daddr.s6_addr32, sizeof(vip.daddr));
+	vip.dport = dport;
+	payload_len = ip6h->payload_len;
+
+	tnl = bpf_map_lookup_elem(&vip2tnl, &vip);
+	/* It only does v6-in-v6 */
+	if (!tnl || tnl->family != AF_INET6)
+		return XDP_PASS;
+
+	/* The vip key is found.  Add an IP header and send it out */
+
+	if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct ipv6hdr)))
+		return XDP_DROP;
+
+	data = (void *)(long)xdp->data;
+	data_end = (void *)(long)xdp->data_end;
+
+	new_eth = data;
+	ip6h = data + sizeof(*new_eth);
+	old_eth = data + sizeof(*ip6h);
+
+	if (new_eth + 1 > data_end ||
+	    old_eth + 1 > data_end ||
+	    ip6h + 1 > data_end)
+		return XDP_DROP;
+
+	set_ethhdr(new_eth, old_eth, tnl, htons(ETH_P_IPV6));
+
+	ip6h->version = 6;
+	ip6h->priority = 0;
+	memset(ip6h->flow_lbl, 0, sizeof(ip6h->flow_lbl));
+	ip6h->payload_len = htons(ntohs(payload_len) + sizeof(*ip6h));
+	ip6h->nexthdr = IPPROTO_IPV6;
+	ip6h->hop_limit = 8;
+	memcpy(ip6h->saddr.s6_addr32, tnl->saddr.v6, sizeof(tnl->saddr.v6));
+	memcpy(ip6h->daddr.s6_addr32, tnl->daddr.v6, sizeof(tnl->daddr.v6));
+
+	count_tx(vip.protocol);
+
+	return XDP_TX;
+}
+
+SEC("xdp_tx_iptunnel")
+int _xdp_tx_iptunnel(struct xdp_md *xdp)
+{
+	void *data_end = (void *)(long)xdp->data_end;
+	void *data = (void *)(long)xdp->data;
+	struct ethhdr *eth = data;
+	__u16 h_proto;
+
+	if (eth + 1 > data_end)
+		return XDP_DROP;
+
+	h_proto = eth->h_proto;
+
+	if (h_proto == htons(ETH_P_IP))
+		return handle_ipv4(xdp);
+	else if (h_proto == htons(ETH_P_IPV6))
+
+		return handle_ipv6(xdp);
+	else
+		return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp_tx_iptunnel_user.c b/samples/bpf/xdp_tx_iptunnel_user.c
new file mode 100644
index 000000000..a419bee15
--- /dev/null
+++ b/samples/bpf/xdp_tx_iptunnel_user.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include <linux/bpf.h>
+#include <linux/if_link.h>
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <net/if.h>
+#include <sys/resource.h>
+#include <arpa/inet.h>
+#include <netinet/ether.h>
+#include <unistd.h>
+#include <time.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include "bpf_util.h"
+#include "xdp_tx_iptunnel_common.h"
+
+#define STATS_INTERVAL_S 2U
+
+static int ifindex = -1;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static int rxcnt_map_fd;
+static __u32 prog_id;
+
+static void int_exit(int sig)
+{
+	__u32 curr_prog_id = 0;
+
+	if (ifindex > -1) {
+		if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
+			printf("bpf_get_link_xdp_id failed\n");
+			exit(1);
+		}
+		if (prog_id == curr_prog_id)
+			bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
+		else if (!curr_prog_id)
+			printf("couldn't find a prog id on a given iface\n");
+		else
+			printf("program on interface changed, not removing\n");
+	}
+	exit(0);
+}
+
+/* simple per-protocol drop counter
+ */
+static void poll_stats(unsigned int kill_after_s)
+{
+	const unsigned int nr_protos = 256;
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	time_t started_at = time(NULL);
+	__u64 values[nr_cpus], prev[nr_protos][nr_cpus];
+	__u32 proto;
+	int i;
+
+	memset(prev, 0, sizeof(prev));
+
+	while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {
+		sleep(STATS_INTERVAL_S);
+
+		for (proto = 0; proto < nr_protos; proto++) {
+			__u64 sum = 0;
+
+			assert(bpf_map_lookup_elem(rxcnt_map_fd, &proto,
+						   values) == 0);
+			for (i = 0; i < nr_cpus; i++)
+				sum += (values[i] - prev[proto][i]);
+
+			if (sum)
+				printf("proto %u: sum:%10llu pkts, rate:%10llu pkts/s\n",
+				       proto, sum, sum / STATS_INTERVAL_S);
+			memcpy(prev[proto], values, sizeof(values));
+		}
+	}
+}
+
+static void usage(const char *cmd)
+{
+	printf("Start a XDP prog which encapsulates incoming packets\n"
+	       "in an IPv4/v6 header and XDP_TX it out.  The dst <VIP:PORT>\n"
+	       "is used to select packets to encapsulate\n\n");
+	printf("Usage: %s [...]\n", cmd);
+	printf("    -i <ifname|ifindex> Interface\n");
+	printf("    -a <vip-service-address> IPv4 or IPv6\n");
+	printf("    -p <vip-service-port> A port range (e.g. 433-444) is also allowed\n");
+	printf("    -s <source-ip> Used in the IPTunnel header\n");
+	printf("    -d <dest-ip> Used in the IPTunnel header\n");
+	printf("    -m <dest-MAC> Used in sending the IP Tunneled pkt\n");
+	printf("    -T <stop-after-X-seconds> Default: 0 (forever)\n");
+	printf("    -P <IP-Protocol> Default is TCP\n");
+	printf("    -S use skb-mode\n");
+	printf("    -N enforce native mode\n");
+	printf("    -F Force loading the XDP prog\n");
+	printf("    -h Display this help\n");
+}
+
+static int parse_ipstr(const char *ipstr, unsigned int *addr)
+{
+	if (inet_pton(AF_INET6, ipstr, addr) == 1) {
+		return AF_INET6;
+	} else if (inet_pton(AF_INET, ipstr, addr) == 1) {
+		addr[1] = addr[2] = addr[3] = 0;
+		return AF_INET;
+	}
+
+	fprintf(stderr, "%s is an invalid IP\n", ipstr);
+	return AF_UNSPEC;
+}
+
+static int parse_ports(const char *port_str, int *min_port, int *max_port)
+{
+	char *end;
+	long tmp_min_port;
+	long tmp_max_port;
+
+	tmp_min_port = strtol(optarg, &end, 10);
+	if (tmp_min_port < 1 || tmp_min_port > 65535) {
+		fprintf(stderr, "Invalid port(s):%s\n", optarg);
+		return 1;
+	}
+
+	if (*end == '-') {
+		end++;
+		tmp_max_port = strtol(end, NULL, 10);
+		if (tmp_max_port < 1 || tmp_max_port > 65535) {
+			fprintf(stderr, "Invalid port(s):%s\n", optarg);
+			return 1;
+		}
+	} else {
+		tmp_max_port = tmp_min_port;
+	}
+
+	if (tmp_min_port > tmp_max_port) {
+		fprintf(stderr, "Invalid port(s):%s\n", optarg);
+		return 1;
+	}
+
+	if (tmp_max_port - tmp_min_port + 1 > MAX_IPTNL_ENTRIES) {
+		fprintf(stderr, "Port range (%s) is larger than %u\n",
+			port_str, MAX_IPTNL_ENTRIES);
+		return 1;
+	}
+	*min_port = tmp_min_port;
+	*max_port = tmp_max_port;
+
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type	= BPF_PROG_TYPE_XDP,
+	};
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	int min_port = 0, max_port = 0, vip2tnl_map_fd;
+	const char *optstr = "i:a:p:s:d:m:T:P:FSNh";
+	unsigned char opt_flags[256] = {};
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	unsigned int kill_after_s = 0;
+	struct iptnl_info tnl = {};
+	struct bpf_object *obj;
+	struct vip vip = {};
+	char filename[256];
+	int opt, prog_fd;
+	int i, err;
+
+	tnl.family = AF_UNSPEC;
+	vip.protocol = IPPROTO_TCP;
+
+	for (i = 0; i < strlen(optstr); i++)
+		if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
+			opt_flags[(unsigned char)optstr[i]] = 1;
+
+	while ((opt = getopt(argc, argv, optstr)) != -1) {
+		unsigned short family;
+		unsigned int *v6;
+
+		switch (opt) {
+		case 'i':
+			ifindex = if_nametoindex(optarg);
+			if (!ifindex)
+				ifindex = atoi(optarg);
+			break;
+		case 'a':
+			vip.family = parse_ipstr(optarg, vip.daddr.v6);
+			if (vip.family == AF_UNSPEC)
+				return 1;
+			break;
+		case 'p':
+			if (parse_ports(optarg, &min_port, &max_port))
+				return 1;
+			break;
+		case 'P':
+			vip.protocol = atoi(optarg);
+			break;
+		case 's':
+		case 'd':
+			if (opt == 's')
+				v6 = tnl.saddr.v6;
+			else
+				v6 = tnl.daddr.v6;
+
+			family = parse_ipstr(optarg, v6);
+			if (family == AF_UNSPEC)
+				return 1;
+			if (tnl.family == AF_UNSPEC) {
+				tnl.family = family;
+			} else if (tnl.family != family) {
+				fprintf(stderr,
+					"The IP version of the src and dst addresses used in the IP encapsulation does not match\n");
+				return 1;
+			}
+			break;
+		case 'm':
+			if (!ether_aton_r(optarg,
+					  (struct ether_addr *)tnl.dmac)) {
+				fprintf(stderr, "Invalid mac address:%s\n",
+					optarg);
+				return 1;
+			}
+			break;
+		case 'T':
+			kill_after_s = atoi(optarg);
+			break;
+		case 'S':
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
+			break;
+		case 'N':
+			/* default, set below */
+			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		default:
+			usage(argv[0]);
+			return 1;
+		}
+		opt_flags[opt] = 0;
+	}
+
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	for (i = 0; i < strlen(optstr); i++) {
+		if (opt_flags[(unsigned int)optstr[i]]) {
+			fprintf(stderr, "Missing argument -%c\n", optstr[i]);
+			usage(argv[0]);
+			return 1;
+		}
+	}
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)");
+		return 1;
+	}
+
+	if (!ifindex) {
+		fprintf(stderr, "Invalid ifname\n");
+		return 1;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	prog_load_attr.file = filename;
+
+	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
+		return 1;
+
+	if (!prog_fd) {
+		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
+		return 1;
+	}
+
+	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
+	vip2tnl_map_fd = bpf_object__find_map_fd_by_name(obj, "vip2tnl");
+	if (vip2tnl_map_fd < 0 || rxcnt_map_fd < 0) {
+		printf("bpf_object__find_map_fd_by_name failed\n");
+		return 1;
+	}
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	while (min_port <= max_port) {
+		vip.dport = htons(min_port++);
+		if (bpf_map_update_elem(vip2tnl_map_fd, &vip, &tnl,
+					BPF_NOEXIST)) {
+			perror("bpf_map_update_elem(&vip2tnl)");
+			return 1;
+		}
+	}
+
+	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
+		printf("link set xdp fd failed\n");
+		return 1;
+	}
+
+	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
+	if (err) {
+		printf("can't get prog info - %s\n", strerror(errno));
+		return err;
+	}
+	prog_id = info.id;
+
+	poll_stats(kill_after_s);
+
+	bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
+
+	return 0;
+}
diff --git a/samples/bpf/xdpsock.h b/samples/bpf/xdpsock.h
new file mode 100644
index 000000000..b7eca15c7
--- /dev/null
+++ b/samples/bpf/xdpsock.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright(c) 2019 Intel Corporation.
+ */
+
+#ifndef XDPSOCK_H_
+#define XDPSOCK_H_
+
+#define MAX_SOCKS 4
+
+#endif /* XDPSOCK_H */
diff --git a/samples/bpf/xdpsock_kern.c b/samples/bpf/xdpsock_kern.c
new file mode 100644
index 000000000..054304843
--- /dev/null
+++ b/samples/bpf/xdpsock_kern.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "xdpsock.h"
+
+/* This XDP program is only needed for the XDP_SHARED_UMEM mode.
+ * If you do not use this mode, libbpf can supply an XDP program for you.
+ */
+
+struct {
+	__uint(type, BPF_MAP_TYPE_XSKMAP);
+	__uint(max_entries, MAX_SOCKS);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(int));
+} xsks_map SEC(".maps");
+
+static unsigned int rr;
+
+SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
+{
+	rr = (rr + 1) & (MAX_SOCKS - 1);
+
+	return bpf_redirect_map(&xsks_map, rr, XDP_DROP);
+}
diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
new file mode 100644
index 000000000..cf5b0a895
--- /dev/null
+++ b/samples/bpf/xdpsock_user.c
@@ -0,0 +1,1550 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2017 - 2018 Intel Corporation. */
+
+#include <asm/barrier.h>
+#include <errno.h>
+#include <getopt.h>
+#include <libgen.h>
+#include <linux/bpf.h>
+#include <linux/compiler.h>
+#include <linux/if_link.h>
+#include <linux/if_xdp.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <linux/limits.h>
+#include <linux/udp.h>
+#include <arpa/inet.h>
+#include <locale.h>
+#include <net/ethernet.h>
+#include <net/if.h>
+#include <poll.h>
+#include <pthread.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/resource.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <bpf/libbpf.h>
+#include <bpf/xsk.h>
+#include <bpf/bpf.h>
+#include "xdpsock.h"
+
+#ifndef SOL_XDP
+#define SOL_XDP 283
+#endif
+
+#ifndef AF_XDP
+#define AF_XDP 44
+#endif
+
+#ifndef PF_XDP
+#define PF_XDP AF_XDP
+#endif
+
+#define NUM_FRAMES (4 * 1024)
+#define MIN_PKT_SIZE 64
+
+#define DEBUG_HEXDUMP 0
+
+typedef __u64 u64;
+typedef __u32 u32;
+typedef __u16 u16;
+typedef __u8  u8;
+
+static unsigned long prev_time;
+
+enum benchmark_type {
+	BENCH_RXDROP = 0,
+	BENCH_TXONLY = 1,
+	BENCH_L2FWD = 2,
+};
+
+static enum benchmark_type opt_bench = BENCH_RXDROP;
+static u32 opt_xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static const char *opt_if = "";
+static int opt_ifindex;
+static int opt_queue;
+static unsigned long opt_duration;
+static unsigned long start_time;
+static bool benchmark_done;
+static u32 opt_batch_size = 64;
+static int opt_pkt_count;
+static u16 opt_pkt_size = MIN_PKT_SIZE;
+static u32 opt_pkt_fill_pattern = 0x12345678;
+static bool opt_extra_stats;
+static bool opt_quiet;
+static bool opt_app_stats;
+static const char *opt_irq_str = "";
+static u32 irq_no;
+static int irqs_at_init = -1;
+static int opt_poll;
+static int opt_interval = 1;
+static u32 opt_xdp_bind_flags = XDP_USE_NEED_WAKEUP;
+static u32 opt_umem_flags;
+static int opt_unaligned_chunks;
+static int opt_mmap_flags;
+static int opt_xsk_frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
+static int opt_timeout = 1000;
+static bool opt_need_wakeup = true;
+static u32 opt_num_xsks = 1;
+static u32 prog_id;
+
+struct xsk_ring_stats {
+	unsigned long rx_npkts;
+	unsigned long tx_npkts;
+	unsigned long rx_dropped_npkts;
+	unsigned long rx_invalid_npkts;
+	unsigned long tx_invalid_npkts;
+	unsigned long rx_full_npkts;
+	unsigned long rx_fill_empty_npkts;
+	unsigned long tx_empty_npkts;
+	unsigned long prev_rx_npkts;
+	unsigned long prev_tx_npkts;
+	unsigned long prev_rx_dropped_npkts;
+	unsigned long prev_rx_invalid_npkts;
+	unsigned long prev_tx_invalid_npkts;
+	unsigned long prev_rx_full_npkts;
+	unsigned long prev_rx_fill_empty_npkts;
+	unsigned long prev_tx_empty_npkts;
+};
+
+struct xsk_driver_stats {
+	unsigned long intrs;
+	unsigned long prev_intrs;
+};
+
+struct xsk_app_stats {
+	unsigned long rx_empty_polls;
+	unsigned long fill_fail_polls;
+	unsigned long copy_tx_sendtos;
+	unsigned long tx_wakeup_sendtos;
+	unsigned long opt_polls;
+	unsigned long prev_rx_empty_polls;
+	unsigned long prev_fill_fail_polls;
+	unsigned long prev_copy_tx_sendtos;
+	unsigned long prev_tx_wakeup_sendtos;
+	unsigned long prev_opt_polls;
+};
+
+struct xsk_umem_info {
+	struct xsk_ring_prod fq;
+	struct xsk_ring_cons cq;
+	struct xsk_umem *umem;
+	void *buffer;
+};
+
+struct xsk_socket_info {
+	struct xsk_ring_cons rx;
+	struct xsk_ring_prod tx;
+	struct xsk_umem_info *umem;
+	struct xsk_socket *xsk;
+	struct xsk_ring_stats ring_stats;
+	struct xsk_app_stats app_stats;
+	struct xsk_driver_stats drv_stats;
+	u32 outstanding_tx;
+};
+
+static int num_socks;
+struct xsk_socket_info *xsks[MAX_SOCKS];
+
+static unsigned long get_nsecs(void)
+{
+	struct timespec ts;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return ts.tv_sec * 1000000000UL + ts.tv_nsec;
+}
+
+static void print_benchmark(bool running)
+{
+	const char *bench_str = "INVALID";
+
+	if (opt_bench == BENCH_RXDROP)
+		bench_str = "rxdrop";
+	else if (opt_bench == BENCH_TXONLY)
+		bench_str = "txonly";
+	else if (opt_bench == BENCH_L2FWD)
+		bench_str = "l2fwd";
+
+	printf("%s:%d %s ", opt_if, opt_queue, bench_str);
+	if (opt_xdp_flags & XDP_FLAGS_SKB_MODE)
+		printf("xdp-skb ");
+	else if (opt_xdp_flags & XDP_FLAGS_DRV_MODE)
+		printf("xdp-drv ");
+	else
+		printf("	");
+
+	if (opt_poll)
+		printf("poll() ");
+
+	if (running) {
+		printf("running...");
+		fflush(stdout);
+	}
+}
+
+static int xsk_get_xdp_stats(int fd, struct xsk_socket_info *xsk)
+{
+	struct xdp_statistics stats;
+	socklen_t optlen;
+	int err;
+
+	optlen = sizeof(stats);
+	err = getsockopt(fd, SOL_XDP, XDP_STATISTICS, &stats, &optlen);
+	if (err)
+		return err;
+
+	if (optlen == sizeof(struct xdp_statistics)) {
+		xsk->ring_stats.rx_dropped_npkts = stats.rx_dropped;
+		xsk->ring_stats.rx_invalid_npkts = stats.rx_invalid_descs;
+		xsk->ring_stats.tx_invalid_npkts = stats.tx_invalid_descs;
+		xsk->ring_stats.rx_full_npkts = stats.rx_ring_full;
+		xsk->ring_stats.rx_fill_empty_npkts = stats.rx_fill_ring_empty_descs;
+		xsk->ring_stats.tx_empty_npkts = stats.tx_ring_empty_descs;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static void dump_app_stats(long dt)
+{
+	int i;
+
+	for (i = 0; i < num_socks && xsks[i]; i++) {
+		char *fmt = "%-18s %'-14.0f %'-14lu\n";
+		double rx_empty_polls_ps, fill_fail_polls_ps, copy_tx_sendtos_ps,
+				tx_wakeup_sendtos_ps, opt_polls_ps;
+
+		rx_empty_polls_ps = (xsks[i]->app_stats.rx_empty_polls -
+					xsks[i]->app_stats.prev_rx_empty_polls) * 1000000000. / dt;
+		fill_fail_polls_ps = (xsks[i]->app_stats.fill_fail_polls -
+					xsks[i]->app_stats.prev_fill_fail_polls) * 1000000000. / dt;
+		copy_tx_sendtos_ps = (xsks[i]->app_stats.copy_tx_sendtos -
+					xsks[i]->app_stats.prev_copy_tx_sendtos) * 1000000000. / dt;
+		tx_wakeup_sendtos_ps = (xsks[i]->app_stats.tx_wakeup_sendtos -
+					xsks[i]->app_stats.prev_tx_wakeup_sendtos)
+										* 1000000000. / dt;
+		opt_polls_ps = (xsks[i]->app_stats.opt_polls -
+					xsks[i]->app_stats.prev_opt_polls) * 1000000000. / dt;
+
+		printf("\n%-18s %-14s %-14s\n", "", "calls/s", "count");
+		printf(fmt, "rx empty polls", rx_empty_polls_ps, xsks[i]->app_stats.rx_empty_polls);
+		printf(fmt, "fill fail polls", fill_fail_polls_ps,
+							xsks[i]->app_stats.fill_fail_polls);
+		printf(fmt, "copy tx sendtos", copy_tx_sendtos_ps,
+							xsks[i]->app_stats.copy_tx_sendtos);
+		printf(fmt, "tx wakeup sendtos", tx_wakeup_sendtos_ps,
+							xsks[i]->app_stats.tx_wakeup_sendtos);
+		printf(fmt, "opt polls", opt_polls_ps, xsks[i]->app_stats.opt_polls);
+
+		xsks[i]->app_stats.prev_rx_empty_polls = xsks[i]->app_stats.rx_empty_polls;
+		xsks[i]->app_stats.prev_fill_fail_polls = xsks[i]->app_stats.fill_fail_polls;
+		xsks[i]->app_stats.prev_copy_tx_sendtos = xsks[i]->app_stats.copy_tx_sendtos;
+		xsks[i]->app_stats.prev_tx_wakeup_sendtos = xsks[i]->app_stats.tx_wakeup_sendtos;
+		xsks[i]->app_stats.prev_opt_polls = xsks[i]->app_stats.opt_polls;
+	}
+}
+
+static bool get_interrupt_number(void)
+{
+	FILE *f_int_proc;
+	char line[4096];
+	bool found = false;
+
+	f_int_proc = fopen("/proc/interrupts", "r");
+	if (f_int_proc == NULL) {
+		printf("Failed to open /proc/interrupts.\n");
+		return found;
+	}
+
+	while (!feof(f_int_proc) && !found) {
+		/* Make sure to read a full line at a time */
+		if (fgets(line, sizeof(line), f_int_proc) == NULL ||
+				line[strlen(line) - 1] != '\n') {
+			printf("Error reading from interrupts file\n");
+			break;
+		}
+
+		/* Extract interrupt number from line */
+		if (strstr(line, opt_irq_str) != NULL) {
+			irq_no = atoi(line);
+			found = true;
+			break;
+		}
+	}
+
+	fclose(f_int_proc);
+
+	return found;
+}
+
+static int get_irqs(void)
+{
+	char count_path[PATH_MAX];
+	int total_intrs = -1;
+	FILE *f_count_proc;
+	char line[4096];
+
+	snprintf(count_path, sizeof(count_path),
+		"/sys/kernel/irq/%i/per_cpu_count", irq_no);
+	f_count_proc = fopen(count_path, "r");
+	if (f_count_proc == NULL) {
+		printf("Failed to open %s\n", count_path);
+		return total_intrs;
+	}
+
+	if (fgets(line, sizeof(line), f_count_proc) == NULL ||
+			line[strlen(line) - 1] != '\n') {
+		printf("Error reading from %s\n", count_path);
+	} else {
+		static const char com[2] = ",";
+		char *token;
+
+		total_intrs = 0;
+		token = strtok(line, com);
+		while (token != NULL) {
+			/* sum up interrupts across all cores */
+			total_intrs += atoi(token);
+			token = strtok(NULL, com);
+		}
+	}
+
+	fclose(f_count_proc);
+
+	return total_intrs;
+}
+
+static void dump_driver_stats(long dt)
+{
+	int i;
+
+	for (i = 0; i < num_socks && xsks[i]; i++) {
+		char *fmt = "%-18s %'-14.0f %'-14lu\n";
+		double intrs_ps;
+		int n_ints = get_irqs();
+
+		if (n_ints < 0) {
+			printf("error getting intr info for intr %i\n", irq_no);
+			return;
+		}
+		xsks[i]->drv_stats.intrs = n_ints - irqs_at_init;
+
+		intrs_ps = (xsks[i]->drv_stats.intrs - xsks[i]->drv_stats.prev_intrs) *
+			 1000000000. / dt;
+
+		printf("\n%-18s %-14s %-14s\n", "", "intrs/s", "count");
+		printf(fmt, "irqs", intrs_ps, xsks[i]->drv_stats.intrs);
+
+		xsks[i]->drv_stats.prev_intrs = xsks[i]->drv_stats.intrs;
+	}
+}
+
+static void dump_stats(void)
+{
+	unsigned long now = get_nsecs();
+	long dt = now - prev_time;
+	int i;
+
+	prev_time = now;
+
+	for (i = 0; i < num_socks && xsks[i]; i++) {
+		char *fmt = "%-18s %'-14.0f %'-14lu\n";
+		double rx_pps, tx_pps, dropped_pps, rx_invalid_pps, full_pps, fill_empty_pps,
+			tx_invalid_pps, tx_empty_pps;
+
+		rx_pps = (xsks[i]->ring_stats.rx_npkts - xsks[i]->ring_stats.prev_rx_npkts) *
+			 1000000000. / dt;
+		tx_pps = (xsks[i]->ring_stats.tx_npkts - xsks[i]->ring_stats.prev_tx_npkts) *
+			 1000000000. / dt;
+
+		printf("\n sock%d@", i);
+		print_benchmark(false);
+		printf("\n");
+
+		printf("%-18s %-14s %-14s %-14.2f\n", "", "pps", "pkts",
+		       dt / 1000000000.);
+		printf(fmt, "rx", rx_pps, xsks[i]->ring_stats.rx_npkts);
+		printf(fmt, "tx", tx_pps, xsks[i]->ring_stats.tx_npkts);
+
+		xsks[i]->ring_stats.prev_rx_npkts = xsks[i]->ring_stats.rx_npkts;
+		xsks[i]->ring_stats.prev_tx_npkts = xsks[i]->ring_stats.tx_npkts;
+
+		if (opt_extra_stats) {
+			if (!xsk_get_xdp_stats(xsk_socket__fd(xsks[i]->xsk), xsks[i])) {
+				dropped_pps = (xsks[i]->ring_stats.rx_dropped_npkts -
+						xsks[i]->ring_stats.prev_rx_dropped_npkts) *
+							1000000000. / dt;
+				rx_invalid_pps = (xsks[i]->ring_stats.rx_invalid_npkts -
+						xsks[i]->ring_stats.prev_rx_invalid_npkts) *
+							1000000000. / dt;
+				tx_invalid_pps = (xsks[i]->ring_stats.tx_invalid_npkts -
+						xsks[i]->ring_stats.prev_tx_invalid_npkts) *
+							1000000000. / dt;
+				full_pps = (xsks[i]->ring_stats.rx_full_npkts -
+						xsks[i]->ring_stats.prev_rx_full_npkts) *
+							1000000000. / dt;
+				fill_empty_pps = (xsks[i]->ring_stats.rx_fill_empty_npkts -
+						xsks[i]->ring_stats.prev_rx_fill_empty_npkts) *
+							1000000000. / dt;
+				tx_empty_pps = (xsks[i]->ring_stats.tx_empty_npkts -
+						xsks[i]->ring_stats.prev_tx_empty_npkts) *
+							1000000000. / dt;
+
+				printf(fmt, "rx dropped", dropped_pps,
+				       xsks[i]->ring_stats.rx_dropped_npkts);
+				printf(fmt, "rx invalid", rx_invalid_pps,
+				       xsks[i]->ring_stats.rx_invalid_npkts);
+				printf(fmt, "tx invalid", tx_invalid_pps,
+				       xsks[i]->ring_stats.tx_invalid_npkts);
+				printf(fmt, "rx queue full", full_pps,
+				       xsks[i]->ring_stats.rx_full_npkts);
+				printf(fmt, "fill ring empty", fill_empty_pps,
+				       xsks[i]->ring_stats.rx_fill_empty_npkts);
+				printf(fmt, "tx ring empty", tx_empty_pps,
+				       xsks[i]->ring_stats.tx_empty_npkts);
+
+				xsks[i]->ring_stats.prev_rx_dropped_npkts =
+					xsks[i]->ring_stats.rx_dropped_npkts;
+				xsks[i]->ring_stats.prev_rx_invalid_npkts =
+					xsks[i]->ring_stats.rx_invalid_npkts;
+				xsks[i]->ring_stats.prev_tx_invalid_npkts =
+					xsks[i]->ring_stats.tx_invalid_npkts;
+				xsks[i]->ring_stats.prev_rx_full_npkts =
+					xsks[i]->ring_stats.rx_full_npkts;
+				xsks[i]->ring_stats.prev_rx_fill_empty_npkts =
+					xsks[i]->ring_stats.rx_fill_empty_npkts;
+				xsks[i]->ring_stats.prev_tx_empty_npkts =
+					xsks[i]->ring_stats.tx_empty_npkts;
+			} else {
+				printf("%-15s\n", "Error retrieving extra stats");
+			}
+		}
+	}
+
+	if (opt_app_stats)
+		dump_app_stats(dt);
+	if (irq_no)
+		dump_driver_stats(dt);
+}
+
+static bool is_benchmark_done(void)
+{
+	if (opt_duration > 0) {
+		unsigned long dt = (get_nsecs() - start_time);
+
+		if (dt >= opt_duration)
+			benchmark_done = true;
+	}
+	return benchmark_done;
+}
+
+static void *poller(void *arg)
+{
+	(void)arg;
+	while (!is_benchmark_done()) {
+		sleep(opt_interval);
+		dump_stats();
+	}
+
+	return NULL;
+}
+
+static void remove_xdp_program(void)
+{
+	u32 curr_prog_id = 0;
+
+	if (bpf_get_link_xdp_id(opt_ifindex, &curr_prog_id, opt_xdp_flags)) {
+		printf("bpf_get_link_xdp_id failed\n");
+		exit(EXIT_FAILURE);
+	}
+	if (prog_id == curr_prog_id)
+		bpf_set_link_xdp_fd(opt_ifindex, -1, opt_xdp_flags);
+	else if (!curr_prog_id)
+		printf("couldn't find a prog id on a given interface\n");
+	else
+		printf("program on interface changed, not removing\n");
+}
+
+static void int_exit(int sig)
+{
+	benchmark_done = true;
+}
+
+static void xdpsock_cleanup(void)
+{
+	struct xsk_umem *umem = xsks[0]->umem->umem;
+	int i;
+
+	dump_stats();
+	for (i = 0; i < num_socks; i++)
+		xsk_socket__delete(xsks[i]->xsk);
+	(void)xsk_umem__delete(umem);
+	remove_xdp_program();
+}
+
+static void __exit_with_error(int error, const char *file, const char *func,
+			      int line)
+{
+	fprintf(stderr, "%s:%s:%i: errno: %d/\"%s\"\n", file, func,
+		line, error, strerror(error));
+	dump_stats();
+	remove_xdp_program();
+	exit(EXIT_FAILURE);
+}
+
+#define exit_with_error(error) __exit_with_error(error, __FILE__, __func__, \
+						 __LINE__)
+static void swap_mac_addresses(void *data)
+{
+	struct ether_header *eth = (struct ether_header *)data;
+	struct ether_addr *src_addr = (struct ether_addr *)&eth->ether_shost;
+	struct ether_addr *dst_addr = (struct ether_addr *)&eth->ether_dhost;
+	struct ether_addr tmp;
+
+	tmp = *src_addr;
+	*src_addr = *dst_addr;
+	*dst_addr = tmp;
+}
+
+static void hex_dump(void *pkt, size_t length, u64 addr)
+{
+	const unsigned char *address = (unsigned char *)pkt;
+	const unsigned char *line = address;
+	size_t line_size = 32;
+	unsigned char c;
+	char buf[32];
+	int i = 0;
+
+	if (!DEBUG_HEXDUMP)
+		return;
+
+	sprintf(buf, "addr=%llu", addr);
+	printf("length = %zu\n", length);
+	printf("%s | ", buf);
+	while (length-- > 0) {
+		printf("%02X ", *address++);
+		if (!(++i % line_size) || (length == 0 && i % line_size)) {
+			if (length == 0) {
+				while (i++ % line_size)
+					printf("__ ");
+			}
+			printf(" | ");	/* right close */
+			while (line < address) {
+				c = *line++;
+				printf("%c", (c < 33 || c == 255) ? 0x2E : c);
+			}
+			printf("\n");
+			if (length > 0)
+				printf("%s | ", buf);
+		}
+	}
+	printf("\n");
+}
+
+static void *memset32_htonl(void *dest, u32 val, u32 size)
+{
+	u32 *ptr = (u32 *)dest;
+	int i;
+
+	val = htonl(val);
+
+	for (i = 0; i < (size & (~0x3)); i += 4)
+		ptr[i >> 2] = val;
+
+	for (; i < size; i++)
+		((char *)dest)[i] = ((char *)&val)[i & 3];
+
+	return dest;
+}
+
+/*
+ * This function code has been taken from
+ * Linux kernel lib/checksum.c
+ */
+static inline unsigned short from32to16(unsigned int x)
+{
+	/* add up 16-bit and 16-bit for 16+c bit */
+	x = (x & 0xffff) + (x >> 16);
+	/* add up carry.. */
+	x = (x & 0xffff) + (x >> 16);
+	return x;
+}
+
+/*
+ * This function code has been taken from
+ * Linux kernel lib/checksum.c
+ */
+static unsigned int do_csum(const unsigned char *buff, int len)
+{
+	unsigned int result = 0;
+	int odd;
+
+	if (len <= 0)
+		goto out;
+	odd = 1 & (unsigned long)buff;
+	if (odd) {
+#ifdef __LITTLE_ENDIAN
+		result += (*buff << 8);
+#else
+		result = *buff;
+#endif
+		len--;
+		buff++;
+	}
+	if (len >= 2) {
+		if (2 & (unsigned long)buff) {
+			result += *(unsigned short *)buff;
+			len -= 2;
+			buff += 2;
+		}
+		if (len >= 4) {
+			const unsigned char *end = buff +
+						   ((unsigned int)len & ~3);
+			unsigned int carry = 0;
+
+			do {
+				unsigned int w = *(unsigned int *)buff;
+
+				buff += 4;
+				result += carry;
+				result += w;
+				carry = (w > result);
+			} while (buff < end);
+			result += carry;
+			result = (result & 0xffff) + (result >> 16);
+		}
+		if (len & 2) {
+			result += *(unsigned short *)buff;
+			buff += 2;
+		}
+	}
+	if (len & 1)
+#ifdef __LITTLE_ENDIAN
+		result += *buff;
+#else
+		result += (*buff << 8);
+#endif
+	result = from32to16(result);
+	if (odd)
+		result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
+out:
+	return result;
+}
+
+__sum16 ip_fast_csum(const void *iph, unsigned int ihl);
+
+/*
+ *	This is a version of ip_compute_csum() optimized for IP headers,
+ *	which always checksum on 4 octet boundaries.
+ *	This function code has been taken from
+ *	Linux kernel lib/checksum.c
+ */
+__sum16 ip_fast_csum(const void *iph, unsigned int ihl)
+{
+	return (__force __sum16)~do_csum(iph, ihl * 4);
+}
+
+/*
+ * Fold a partial checksum
+ * This function code has been taken from
+ * Linux kernel include/asm-generic/checksum.h
+ */
+static inline __sum16 csum_fold(__wsum csum)
+{
+	u32 sum = (__force u32)csum;
+
+	sum = (sum & 0xffff) + (sum >> 16);
+	sum = (sum & 0xffff) + (sum >> 16);
+	return (__force __sum16)~sum;
+}
+
+/*
+ * This function code has been taken from
+ * Linux kernel lib/checksum.c
+ */
+static inline u32 from64to32(u64 x)
+{
+	/* add up 32-bit and 32-bit for 32+c bit */
+	x = (x & 0xffffffff) + (x >> 32);
+	/* add up carry.. */
+	x = (x & 0xffffffff) + (x >> 32);
+	return (u32)x;
+}
+
+__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
+			  __u32 len, __u8 proto, __wsum sum);
+
+/*
+ * This function code has been taken from
+ * Linux kernel lib/checksum.c
+ */
+__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
+			  __u32 len, __u8 proto, __wsum sum)
+{
+	unsigned long long s = (__force u32)sum;
+
+	s += (__force u32)saddr;
+	s += (__force u32)daddr;
+#ifdef __BIG_ENDIAN__
+	s += proto + len;
+#else
+	s += (proto + len) << 8;
+#endif
+	return (__force __wsum)from64to32(s);
+}
+
+/*
+ * This function has been taken from
+ * Linux kernel include/asm-generic/checksum.h
+ */
+static inline __sum16
+csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
+		  __u8 proto, __wsum sum)
+{
+	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
+}
+
+static inline u16 udp_csum(u32 saddr, u32 daddr, u32 len,
+			   u8 proto, u16 *udp_pkt)
+{
+	u32 csum = 0;
+	u32 cnt = 0;
+
+	/* udp hdr and data */
+	for (; cnt < len; cnt += 2)
+		csum += udp_pkt[cnt >> 1];
+
+	return csum_tcpudp_magic(saddr, daddr, len, proto, csum);
+}
+
+#define ETH_FCS_SIZE 4
+
+#define PKT_HDR_SIZE (sizeof(struct ethhdr) + sizeof(struct iphdr) + \
+		      sizeof(struct udphdr))
+
+#define PKT_SIZE		(opt_pkt_size - ETH_FCS_SIZE)
+#define IP_PKT_SIZE		(PKT_SIZE - sizeof(struct ethhdr))
+#define UDP_PKT_SIZE		(IP_PKT_SIZE - sizeof(struct iphdr))
+#define UDP_PKT_DATA_SIZE	(UDP_PKT_SIZE - sizeof(struct udphdr))
+
+static u8 pkt_data[XSK_UMEM__DEFAULT_FRAME_SIZE];
+
+static void gen_eth_hdr_data(void)
+{
+	struct udphdr *udp_hdr = (struct udphdr *)(pkt_data +
+						   sizeof(struct ethhdr) +
+						   sizeof(struct iphdr));
+	struct iphdr *ip_hdr = (struct iphdr *)(pkt_data +
+						sizeof(struct ethhdr));
+	struct ethhdr *eth_hdr = (struct ethhdr *)pkt_data;
+
+	/* ethernet header */
+	memcpy(eth_hdr->h_dest, "\x3c\xfd\xfe\x9e\x7f\x71", ETH_ALEN);
+	memcpy(eth_hdr->h_source, "\xec\xb1\xd7\x98\x3a\xc0", ETH_ALEN);
+	eth_hdr->h_proto = htons(ETH_P_IP);
+
+	/* IP header */
+	ip_hdr->version = IPVERSION;
+	ip_hdr->ihl = 0x5; /* 20 byte header */
+	ip_hdr->tos = 0x0;
+	ip_hdr->tot_len = htons(IP_PKT_SIZE);
+	ip_hdr->id = 0;
+	ip_hdr->frag_off = 0;
+	ip_hdr->ttl = IPDEFTTL;
+	ip_hdr->protocol = IPPROTO_UDP;
+	ip_hdr->saddr = htonl(0x0a0a0a10);
+	ip_hdr->daddr = htonl(0x0a0a0a20);
+
+	/* IP header checksum */
+	ip_hdr->check = 0;
+	ip_hdr->check = ip_fast_csum((const void *)ip_hdr, ip_hdr->ihl);
+
+	/* UDP header */
+	udp_hdr->source = htons(0x1000);
+	udp_hdr->dest = htons(0x1000);
+	udp_hdr->len = htons(UDP_PKT_SIZE);
+
+	/* UDP data */
+	memset32_htonl(pkt_data + PKT_HDR_SIZE, opt_pkt_fill_pattern,
+		       UDP_PKT_DATA_SIZE);
+
+	/* UDP header checksum */
+	udp_hdr->check = 0;
+	udp_hdr->check = udp_csum(ip_hdr->saddr, ip_hdr->daddr, UDP_PKT_SIZE,
+				  IPPROTO_UDP, (u16 *)udp_hdr);
+}
+
+static void gen_eth_frame(struct xsk_umem_info *umem, u64 addr)
+{
+	memcpy(xsk_umem__get_data(umem->buffer, addr), pkt_data,
+	       PKT_SIZE);
+}
+
+static struct xsk_umem_info *xsk_configure_umem(void *buffer, u64 size)
+{
+	struct xsk_umem_info *umem;
+	struct xsk_umem_config cfg = {
+		/* We recommend that you set the fill ring size >= HW RX ring size +
+		 * AF_XDP RX ring size. Make sure you fill up the fill ring
+		 * with buffers at regular intervals, and you will with this setting
+		 * avoid allocation failures in the driver. These are usually quite
+		 * expensive since drivers have not been written to assume that
+		 * allocation failures are common. For regular sockets, kernel
+		 * allocated memory is used that only runs out in OOM situations
+		 * that should be rare.
+		 */
+		.fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS * 2,
+		.comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS,
+		.frame_size = opt_xsk_frame_size,
+		.frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM,
+		.flags = opt_umem_flags
+	};
+	int ret;
+
+	umem = calloc(1, sizeof(*umem));
+	if (!umem)
+		exit_with_error(errno);
+
+	ret = xsk_umem__create(&umem->umem, buffer, size, &umem->fq, &umem->cq,
+			       &cfg);
+	if (ret)
+		exit_with_error(-ret);
+
+	umem->buffer = buffer;
+	return umem;
+}
+
+static void xsk_populate_fill_ring(struct xsk_umem_info *umem)
+{
+	int ret, i;
+	u32 idx;
+
+	ret = xsk_ring_prod__reserve(&umem->fq,
+				     XSK_RING_PROD__DEFAULT_NUM_DESCS * 2, &idx);
+	if (ret != XSK_RING_PROD__DEFAULT_NUM_DESCS * 2)
+		exit_with_error(-ret);
+	for (i = 0; i < XSK_RING_PROD__DEFAULT_NUM_DESCS * 2; i++)
+		*xsk_ring_prod__fill_addr(&umem->fq, idx++) =
+			i * opt_xsk_frame_size;
+	xsk_ring_prod__submit(&umem->fq, XSK_RING_PROD__DEFAULT_NUM_DESCS * 2);
+}
+
+static struct xsk_socket_info *xsk_configure_socket(struct xsk_umem_info *umem,
+						    bool rx, bool tx)
+{
+	struct xsk_socket_config cfg;
+	struct xsk_socket_info *xsk;
+	struct xsk_ring_cons *rxr;
+	struct xsk_ring_prod *txr;
+	int ret;
+
+	xsk = calloc(1, sizeof(*xsk));
+	if (!xsk)
+		exit_with_error(errno);
+
+	xsk->umem = umem;
+	cfg.rx_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
+	cfg.tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
+	if (opt_num_xsks > 1)
+		cfg.libbpf_flags = XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD;
+	else
+		cfg.libbpf_flags = 0;
+	cfg.xdp_flags = opt_xdp_flags;
+	cfg.bind_flags = opt_xdp_bind_flags;
+
+	rxr = rx ? &xsk->rx : NULL;
+	txr = tx ? &xsk->tx : NULL;
+	ret = xsk_socket__create(&xsk->xsk, opt_if, opt_queue, umem->umem,
+				 rxr, txr, &cfg);
+	if (ret)
+		exit_with_error(-ret);
+
+	ret = bpf_get_link_xdp_id(opt_ifindex, &prog_id, opt_xdp_flags);
+	if (ret)
+		exit_with_error(-ret);
+
+	xsk->app_stats.rx_empty_polls = 0;
+	xsk->app_stats.fill_fail_polls = 0;
+	xsk->app_stats.copy_tx_sendtos = 0;
+	xsk->app_stats.tx_wakeup_sendtos = 0;
+	xsk->app_stats.opt_polls = 0;
+	xsk->app_stats.prev_rx_empty_polls = 0;
+	xsk->app_stats.prev_fill_fail_polls = 0;
+	xsk->app_stats.prev_copy_tx_sendtos = 0;
+	xsk->app_stats.prev_tx_wakeup_sendtos = 0;
+	xsk->app_stats.prev_opt_polls = 0;
+
+	return xsk;
+}
+
+static struct option long_options[] = {
+	{"rxdrop", no_argument, 0, 'r'},
+	{"txonly", no_argument, 0, 't'},
+	{"l2fwd", no_argument, 0, 'l'},
+	{"interface", required_argument, 0, 'i'},
+	{"queue", required_argument, 0, 'q'},
+	{"poll", no_argument, 0, 'p'},
+	{"xdp-skb", no_argument, 0, 'S'},
+	{"xdp-native", no_argument, 0, 'N'},
+	{"interval", required_argument, 0, 'n'},
+	{"zero-copy", no_argument, 0, 'z'},
+	{"copy", no_argument, 0, 'c'},
+	{"frame-size", required_argument, 0, 'f'},
+	{"no-need-wakeup", no_argument, 0, 'm'},
+	{"unaligned", no_argument, 0, 'u'},
+	{"shared-umem", no_argument, 0, 'M'},
+	{"force", no_argument, 0, 'F'},
+	{"duration", required_argument, 0, 'd'},
+	{"batch-size", required_argument, 0, 'b'},
+	{"tx-pkt-count", required_argument, 0, 'C'},
+	{"tx-pkt-size", required_argument, 0, 's'},
+	{"tx-pkt-pattern", required_argument, 0, 'P'},
+	{"extra-stats", no_argument, 0, 'x'},
+	{"quiet", no_argument, 0, 'Q'},
+	{"app-stats", no_argument, 0, 'a'},
+	{"irq-string", no_argument, 0, 'I'},
+	{0, 0, 0, 0}
+};
+
+static void usage(const char *prog)
+{
+	const char *str =
+		"  Usage: %s [OPTIONS]\n"
+		"  Options:\n"
+		"  -r, --rxdrop		Discard all incoming packets (default)\n"
+		"  -t, --txonly		Only send packets\n"
+		"  -l, --l2fwd		MAC swap L2 forwarding\n"
+		"  -i, --interface=n	Run on interface n\n"
+		"  -q, --queue=n	Use queue n (default 0)\n"
+		"  -p, --poll		Use poll syscall\n"
+		"  -S, --xdp-skb=n	Use XDP skb-mod\n"
+		"  -N, --xdp-native=n	Enforce XDP native mode\n"
+		"  -n, --interval=n	Specify statistics update interval (default 1 sec).\n"
+		"  -z, --zero-copy      Force zero-copy mode.\n"
+		"  -c, --copy           Force copy mode.\n"
+		"  -m, --no-need-wakeup Turn off use of driver need wakeup flag.\n"
+		"  -f, --frame-size=n   Set the frame size (must be a power of two in aligned mode, default is %d).\n"
+		"  -u, --unaligned	Enable unaligned chunk placement\n"
+		"  -M, --shared-umem	Enable XDP_SHARED_UMEM\n"
+		"  -F, --force		Force loading the XDP prog\n"
+		"  -d, --duration=n	Duration in secs to run command.\n"
+		"			Default: forever.\n"
+		"  -b, --batch-size=n	Batch size for sending or receiving\n"
+		"			packets. Default: %d\n"
+		"  -C, --tx-pkt-count=n	Number of packets to send.\n"
+		"			Default: Continuous packets.\n"
+		"  -s, --tx-pkt-size=n	Transmit packet size.\n"
+		"			(Default: %d bytes)\n"
+		"			Min size: %d, Max size %d.\n"
+		"  -P, --tx-pkt-pattern=nPacket fill pattern. Default: 0x%x\n"
+		"  -x, --extra-stats	Display extra statistics.\n"
+		"  -Q, --quiet          Do not display any stats.\n"
+		"  -a, --app-stats	Display application (syscall) statistics.\n"
+		"  -I, --irq-string	Display driver interrupt statistics for interface associated with irq-string.\n"
+		"\n";
+	fprintf(stderr, str, prog, XSK_UMEM__DEFAULT_FRAME_SIZE,
+		opt_batch_size, MIN_PKT_SIZE, MIN_PKT_SIZE,
+		XSK_UMEM__DEFAULT_FRAME_SIZE, opt_pkt_fill_pattern);
+
+	exit(EXIT_FAILURE);
+}
+
+static void parse_command_line(int argc, char **argv)
+{
+	int option_index, c;
+
+	opterr = 0;
+
+	for (;;) {
+		c = getopt_long(argc, argv, "Frtli:q:pSNn:czf:muMd:b:C:s:P:xQaI:",
+				long_options, &option_index);
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'r':
+			opt_bench = BENCH_RXDROP;
+			break;
+		case 't':
+			opt_bench = BENCH_TXONLY;
+			break;
+		case 'l':
+			opt_bench = BENCH_L2FWD;
+			break;
+		case 'i':
+			opt_if = optarg;
+			break;
+		case 'q':
+			opt_queue = atoi(optarg);
+			break;
+		case 'p':
+			opt_poll = 1;
+			break;
+		case 'S':
+			opt_xdp_flags |= XDP_FLAGS_SKB_MODE;
+			opt_xdp_bind_flags |= XDP_COPY;
+			break;
+		case 'N':
+			/* default, set below */
+			break;
+		case 'n':
+			opt_interval = atoi(optarg);
+			break;
+		case 'z':
+			opt_xdp_bind_flags |= XDP_ZEROCOPY;
+			break;
+		case 'c':
+			opt_xdp_bind_flags |= XDP_COPY;
+			break;
+		case 'u':
+			opt_umem_flags |= XDP_UMEM_UNALIGNED_CHUNK_FLAG;
+			opt_unaligned_chunks = 1;
+			opt_mmap_flags = MAP_HUGETLB;
+			break;
+		case 'F':
+			opt_xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		case 'f':
+			opt_xsk_frame_size = atoi(optarg);
+			break;
+		case 'm':
+			opt_need_wakeup = false;
+			opt_xdp_bind_flags &= ~XDP_USE_NEED_WAKEUP;
+			break;
+		case 'M':
+			opt_num_xsks = MAX_SOCKS;
+			break;
+		case 'd':
+			opt_duration = atoi(optarg);
+			opt_duration *= 1000000000;
+			break;
+		case 'b':
+			opt_batch_size = atoi(optarg);
+			break;
+		case 'C':
+			opt_pkt_count = atoi(optarg);
+			break;
+		case 's':
+			opt_pkt_size = atoi(optarg);
+			if (opt_pkt_size > (XSK_UMEM__DEFAULT_FRAME_SIZE) ||
+			    opt_pkt_size < MIN_PKT_SIZE) {
+				fprintf(stderr,
+					"ERROR: Invalid frame size %d\n",
+					opt_pkt_size);
+				usage(basename(argv[0]));
+			}
+			break;
+		case 'P':
+			opt_pkt_fill_pattern = strtol(optarg, NULL, 16);
+			break;
+		case 'x':
+			opt_extra_stats = 1;
+			break;
+		case 'Q':
+			opt_quiet = 1;
+			break;
+		case 'a':
+			opt_app_stats = 1;
+			break;
+		case 'I':
+			opt_irq_str = optarg;
+			if (get_interrupt_number())
+				irqs_at_init = get_irqs();
+			if (irqs_at_init < 0) {
+				fprintf(stderr, "ERROR: Failed to get irqs for %s\n", opt_irq_str);
+				usage(basename(argv[0]));
+			}
+
+			break;
+		default:
+			usage(basename(argv[0]));
+		}
+	}
+
+	if (!(opt_xdp_flags & XDP_FLAGS_SKB_MODE))
+		opt_xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	opt_ifindex = if_nametoindex(opt_if);
+	if (!opt_ifindex) {
+		fprintf(stderr, "ERROR: interface \"%s\" does not exist\n",
+			opt_if);
+		usage(basename(argv[0]));
+	}
+
+	if ((opt_xsk_frame_size & (opt_xsk_frame_size - 1)) &&
+	    !opt_unaligned_chunks) {
+		fprintf(stderr, "--frame-size=%d is not a power of two\n",
+			opt_xsk_frame_size);
+		usage(basename(argv[0]));
+	}
+}
+
+static void kick_tx(struct xsk_socket_info *xsk)
+{
+	int ret;
+
+	ret = sendto(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, 0);
+	if (ret >= 0 || errno == ENOBUFS || errno == EAGAIN ||
+	    errno == EBUSY || errno == ENETDOWN)
+		return;
+	exit_with_error(errno);
+}
+
+static inline void complete_tx_l2fwd(struct xsk_socket_info *xsk,
+				     struct pollfd *fds)
+{
+	struct xsk_umem_info *umem = xsk->umem;
+	u32 idx_cq = 0, idx_fq = 0;
+	unsigned int rcvd;
+	size_t ndescs;
+
+	if (!xsk->outstanding_tx)
+		return;
+
+	/* In copy mode, Tx is driven by a syscall so we need to use e.g. sendto() to
+	 * really send the packets. In zero-copy mode we do not have to do this, since Tx
+	 * is driven by the NAPI loop. So as an optimization, we do not have to call
+	 * sendto() all the time in zero-copy mode for l2fwd.
+	 */
+	if (opt_xdp_bind_flags & XDP_COPY) {
+		xsk->app_stats.copy_tx_sendtos++;
+		kick_tx(xsk);
+	}
+
+	ndescs = (xsk->outstanding_tx > opt_batch_size) ? opt_batch_size :
+		xsk->outstanding_tx;
+
+	/* re-add completed Tx buffers */
+	rcvd = xsk_ring_cons__peek(&umem->cq, ndescs, &idx_cq);
+	if (rcvd > 0) {
+		unsigned int i;
+		int ret;
+
+		ret = xsk_ring_prod__reserve(&umem->fq, rcvd, &idx_fq);
+		while (ret != rcvd) {
+			if (ret < 0)
+				exit_with_error(-ret);
+			if (xsk_ring_prod__needs_wakeup(&umem->fq)) {
+				xsk->app_stats.fill_fail_polls++;
+				ret = poll(fds, num_socks, opt_timeout);
+			}
+			ret = xsk_ring_prod__reserve(&umem->fq, rcvd, &idx_fq);
+		}
+
+		for (i = 0; i < rcvd; i++)
+			*xsk_ring_prod__fill_addr(&umem->fq, idx_fq++) =
+				*xsk_ring_cons__comp_addr(&umem->cq, idx_cq++);
+
+		xsk_ring_prod__submit(&xsk->umem->fq, rcvd);
+		xsk_ring_cons__release(&xsk->umem->cq, rcvd);
+		xsk->outstanding_tx -= rcvd;
+		xsk->ring_stats.tx_npkts += rcvd;
+	}
+}
+
+static inline void complete_tx_only(struct xsk_socket_info *xsk,
+				    int batch_size)
+{
+	unsigned int rcvd;
+	u32 idx;
+
+	if (!xsk->outstanding_tx)
+		return;
+
+	if (!opt_need_wakeup || xsk_ring_prod__needs_wakeup(&xsk->tx)) {
+		xsk->app_stats.tx_wakeup_sendtos++;
+		kick_tx(xsk);
+	}
+
+	rcvd = xsk_ring_cons__peek(&xsk->umem->cq, batch_size, &idx);
+	if (rcvd > 0) {
+		xsk_ring_cons__release(&xsk->umem->cq, rcvd);
+		xsk->outstanding_tx -= rcvd;
+		xsk->ring_stats.tx_npkts += rcvd;
+	}
+}
+
+static void rx_drop(struct xsk_socket_info *xsk, struct pollfd *fds)
+{
+	unsigned int rcvd, i;
+	u32 idx_rx = 0, idx_fq = 0;
+	int ret;
+
+	rcvd = xsk_ring_cons__peek(&xsk->rx, opt_batch_size, &idx_rx);
+	if (!rcvd) {
+		if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {
+			xsk->app_stats.rx_empty_polls++;
+			ret = poll(fds, num_socks, opt_timeout);
+		}
+		return;
+	}
+
+	ret = xsk_ring_prod__reserve(&xsk->umem->fq, rcvd, &idx_fq);
+	while (ret != rcvd) {
+		if (ret < 0)
+			exit_with_error(-ret);
+		if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {
+			xsk->app_stats.fill_fail_polls++;
+			ret = poll(fds, num_socks, opt_timeout);
+		}
+		ret = xsk_ring_prod__reserve(&xsk->umem->fq, rcvd, &idx_fq);
+	}
+
+	for (i = 0; i < rcvd; i++) {
+		u64 addr = xsk_ring_cons__rx_desc(&xsk->rx, idx_rx)->addr;
+		u32 len = xsk_ring_cons__rx_desc(&xsk->rx, idx_rx++)->len;
+		u64 orig = xsk_umem__extract_addr(addr);
+
+		addr = xsk_umem__add_offset_to_addr(addr);
+		char *pkt = xsk_umem__get_data(xsk->umem->buffer, addr);
+
+		hex_dump(pkt, len, addr);
+		*xsk_ring_prod__fill_addr(&xsk->umem->fq, idx_fq++) = orig;
+	}
+
+	xsk_ring_prod__submit(&xsk->umem->fq, rcvd);
+	xsk_ring_cons__release(&xsk->rx, rcvd);
+	xsk->ring_stats.rx_npkts += rcvd;
+}
+
+static void rx_drop_all(void)
+{
+	struct pollfd fds[MAX_SOCKS] = {};
+	int i, ret;
+
+	for (i = 0; i < num_socks; i++) {
+		fds[i].fd = xsk_socket__fd(xsks[i]->xsk);
+		fds[i].events = POLLIN;
+	}
+
+	for (;;) {
+		if (opt_poll) {
+			for (i = 0; i < num_socks; i++)
+				xsks[i]->app_stats.opt_polls++;
+			ret = poll(fds, num_socks, opt_timeout);
+			if (ret <= 0)
+				continue;
+		}
+
+		for (i = 0; i < num_socks; i++)
+			rx_drop(xsks[i], fds);
+
+		if (benchmark_done)
+			break;
+	}
+}
+
+static void tx_only(struct xsk_socket_info *xsk, u32 *frame_nb, int batch_size)
+{
+	u32 idx;
+	unsigned int i;
+
+	while (xsk_ring_prod__reserve(&xsk->tx, batch_size, &idx) <
+				      batch_size) {
+		complete_tx_only(xsk, batch_size);
+		if (benchmark_done)
+			return;
+	}
+
+	for (i = 0; i < batch_size; i++) {
+		struct xdp_desc *tx_desc = xsk_ring_prod__tx_desc(&xsk->tx,
+								  idx + i);
+		tx_desc->addr = (*frame_nb + i) * opt_xsk_frame_size;
+		tx_desc->len = PKT_SIZE;
+	}
+
+	xsk_ring_prod__submit(&xsk->tx, batch_size);
+	xsk->outstanding_tx += batch_size;
+	*frame_nb += batch_size;
+	*frame_nb %= NUM_FRAMES;
+	complete_tx_only(xsk, batch_size);
+}
+
+static inline int get_batch_size(int pkt_cnt)
+{
+	if (!opt_pkt_count)
+		return opt_batch_size;
+
+	if (pkt_cnt + opt_batch_size <= opt_pkt_count)
+		return opt_batch_size;
+
+	return opt_pkt_count - pkt_cnt;
+}
+
+static void complete_tx_only_all(void)
+{
+	bool pending;
+	int i;
+
+	do {
+		pending = false;
+		for (i = 0; i < num_socks; i++) {
+			if (xsks[i]->outstanding_tx) {
+				complete_tx_only(xsks[i], opt_batch_size);
+				pending = !!xsks[i]->outstanding_tx;
+			}
+		}
+	} while (pending);
+}
+
+static void tx_only_all(void)
+{
+	struct pollfd fds[MAX_SOCKS] = {};
+	u32 frame_nb[MAX_SOCKS] = {};
+	int pkt_cnt = 0;
+	int i, ret;
+
+	for (i = 0; i < num_socks; i++) {
+		fds[0].fd = xsk_socket__fd(xsks[i]->xsk);
+		fds[0].events = POLLOUT;
+	}
+
+	while ((opt_pkt_count && pkt_cnt < opt_pkt_count) || !opt_pkt_count) {
+		int batch_size = get_batch_size(pkt_cnt);
+
+		if (opt_poll) {
+			for (i = 0; i < num_socks; i++)
+				xsks[i]->app_stats.opt_polls++;
+			ret = poll(fds, num_socks, opt_timeout);
+			if (ret <= 0)
+				continue;
+
+			if (!(fds[0].revents & POLLOUT))
+				continue;
+		}
+
+		for (i = 0; i < num_socks; i++)
+			tx_only(xsks[i], &frame_nb[i], batch_size);
+
+		pkt_cnt += batch_size;
+
+		if (benchmark_done)
+			break;
+	}
+
+	if (opt_pkt_count)
+		complete_tx_only_all();
+}
+
+static void l2fwd(struct xsk_socket_info *xsk, struct pollfd *fds)
+{
+	unsigned int rcvd, i;
+	u32 idx_rx = 0, idx_tx = 0;
+	int ret;
+
+	complete_tx_l2fwd(xsk, fds);
+
+	rcvd = xsk_ring_cons__peek(&xsk->rx, opt_batch_size, &idx_rx);
+	if (!rcvd) {
+		if (xsk_ring_prod__needs_wakeup(&xsk->umem->fq)) {
+			xsk->app_stats.rx_empty_polls++;
+			ret = poll(fds, num_socks, opt_timeout);
+		}
+		return;
+	}
+
+	ret = xsk_ring_prod__reserve(&xsk->tx, rcvd, &idx_tx);
+	while (ret != rcvd) {
+		if (ret < 0)
+			exit_with_error(-ret);
+		complete_tx_l2fwd(xsk, fds);
+		if (xsk_ring_prod__needs_wakeup(&xsk->tx)) {
+			xsk->app_stats.tx_wakeup_sendtos++;
+			kick_tx(xsk);
+		}
+		ret = xsk_ring_prod__reserve(&xsk->tx, rcvd, &idx_tx);
+	}
+
+	for (i = 0; i < rcvd; i++) {
+		u64 addr = xsk_ring_cons__rx_desc(&xsk->rx, idx_rx)->addr;
+		u32 len = xsk_ring_cons__rx_desc(&xsk->rx, idx_rx++)->len;
+		u64 orig = addr;
+
+		addr = xsk_umem__add_offset_to_addr(addr);
+		char *pkt = xsk_umem__get_data(xsk->umem->buffer, addr);
+
+		swap_mac_addresses(pkt);
+
+		hex_dump(pkt, len, addr);
+		xsk_ring_prod__tx_desc(&xsk->tx, idx_tx)->addr = orig;
+		xsk_ring_prod__tx_desc(&xsk->tx, idx_tx++)->len = len;
+	}
+
+	xsk_ring_prod__submit(&xsk->tx, rcvd);
+	xsk_ring_cons__release(&xsk->rx, rcvd);
+
+	xsk->ring_stats.rx_npkts += rcvd;
+	xsk->outstanding_tx += rcvd;
+}
+
+static void l2fwd_all(void)
+{
+	struct pollfd fds[MAX_SOCKS] = {};
+	int i, ret;
+
+	for (i = 0; i < num_socks; i++) {
+		fds[i].fd = xsk_socket__fd(xsks[i]->xsk);
+		fds[i].events = POLLOUT | POLLIN;
+	}
+
+	for (;;) {
+		if (opt_poll) {
+			for (i = 0; i < num_socks; i++)
+				xsks[i]->app_stats.opt_polls++;
+			ret = poll(fds, num_socks, opt_timeout);
+			if (ret <= 0)
+				continue;
+		}
+
+		for (i = 0; i < num_socks; i++)
+			l2fwd(xsks[i], fds);
+
+		if (benchmark_done)
+			break;
+	}
+}
+
+static void load_xdp_program(char **argv, struct bpf_object **obj)
+{
+	struct bpf_prog_load_attr prog_load_attr = {
+		.prog_type      = BPF_PROG_TYPE_XDP,
+	};
+	char xdp_filename[256];
+	int prog_fd;
+
+	snprintf(xdp_filename, sizeof(xdp_filename), "%s_kern.o", argv[0]);
+	prog_load_attr.file = xdp_filename;
+
+	if (bpf_prog_load_xattr(&prog_load_attr, obj, &prog_fd))
+		exit(EXIT_FAILURE);
+	if (prog_fd < 0) {
+		fprintf(stderr, "ERROR: no program found: %s\n",
+			strerror(prog_fd));
+		exit(EXIT_FAILURE);
+	}
+
+	if (bpf_set_link_xdp_fd(opt_ifindex, prog_fd, opt_xdp_flags) < 0) {
+		fprintf(stderr, "ERROR: link set xdp fd failed\n");
+		exit(EXIT_FAILURE);
+	}
+}
+
+static void enter_xsks_into_map(struct bpf_object *obj)
+{
+	struct bpf_map *map;
+	int i, xsks_map;
+
+	map = bpf_object__find_map_by_name(obj, "xsks_map");
+	xsks_map = bpf_map__fd(map);
+	if (xsks_map < 0) {
+		fprintf(stderr, "ERROR: no xsks map found: %s\n",
+			strerror(xsks_map));
+			exit(EXIT_FAILURE);
+	}
+
+	for (i = 0; i < num_socks; i++) {
+		int fd = xsk_socket__fd(xsks[i]->xsk);
+		int key, ret;
+
+		key = i;
+		ret = bpf_map_update_elem(xsks_map, &key, &fd, 0);
+		if (ret) {
+			fprintf(stderr, "ERROR: bpf_map_update_elem %d\n", i);
+			exit(EXIT_FAILURE);
+		}
+	}
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	bool rx = false, tx = false;
+	struct xsk_umem_info *umem;
+	struct bpf_object *obj;
+	pthread_t pt;
+	int i, ret;
+	void *bufs;
+
+	parse_command_line(argc, argv);
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		fprintf(stderr, "ERROR: setrlimit(RLIMIT_MEMLOCK) \"%s\"\n",
+			strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+
+	if (opt_num_xsks > 1)
+		load_xdp_program(argv, &obj);
+
+	/* Reserve memory for the umem. Use hugepages if unaligned chunk mode */
+	bufs = mmap(NULL, NUM_FRAMES * opt_xsk_frame_size,
+		    PROT_READ | PROT_WRITE,
+		    MAP_PRIVATE | MAP_ANONYMOUS | opt_mmap_flags, -1, 0);
+	if (bufs == MAP_FAILED) {
+		printf("ERROR: mmap failed\n");
+		exit(EXIT_FAILURE);
+	}
+
+	/* Create sockets... */
+	umem = xsk_configure_umem(bufs, NUM_FRAMES * opt_xsk_frame_size);
+	if (opt_bench == BENCH_RXDROP || opt_bench == BENCH_L2FWD) {
+		rx = true;
+		xsk_populate_fill_ring(umem);
+	}
+	if (opt_bench == BENCH_L2FWD || opt_bench == BENCH_TXONLY)
+		tx = true;
+	for (i = 0; i < opt_num_xsks; i++)
+		xsks[num_socks++] = xsk_configure_socket(umem, rx, tx);
+
+	if (opt_bench == BENCH_TXONLY) {
+		gen_eth_hdr_data();
+
+		for (i = 0; i < NUM_FRAMES; i++)
+			gen_eth_frame(umem, i * opt_xsk_frame_size);
+	}
+
+	if (opt_num_xsks > 1 && opt_bench != BENCH_TXONLY)
+		enter_xsks_into_map(obj);
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+	signal(SIGABRT, int_exit);
+
+	setlocale(LC_ALL, "");
+
+	prev_time = get_nsecs();
+	start_time = prev_time;
+
+	if (!opt_quiet) {
+		ret = pthread_create(&pt, NULL, poller, NULL);
+		if (ret)
+			exit_with_error(ret);
+	}
+
+
+	if (opt_bench == BENCH_RXDROP)
+		rx_drop_all();
+	else if (opt_bench == BENCH_TXONLY)
+		tx_only_all();
+	else
+		l2fwd_all();
+
+	benchmark_done = true;
+
+	if (!opt_quiet)
+		pthread_join(pt, NULL);
+
+	xdpsock_cleanup();
+
+	munmap(bufs, NUM_FRAMES * opt_xsk_frame_size);
+
+	return 0;
+}
diff --git a/samples/bpf/xsk_fwd.c b/samples/bpf/xsk_fwd.c
new file mode 100644
index 000000000..1cd97c84c
--- /dev/null
+++ b/samples/bpf/xsk_fwd.c
@@ -0,0 +1,1085 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2020 Intel Corporation. */
+
+#define _GNU_SOURCE
+#include <poll.h>
+#include <pthread.h>
+#include <signal.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/resource.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <netinet/ether.h>
+#include <net/if.h>
+
+#include <linux/bpf.h>
+#include <linux/if_link.h>
+#include <linux/if_xdp.h>
+
+#include <bpf/libbpf.h>
+#include <bpf/xsk.h>
+#include <bpf/bpf.h>
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+typedef __u64 u64;
+typedef __u32 u32;
+typedef __u16 u16;
+typedef __u8  u8;
+
+/* This program illustrates the packet forwarding between multiple AF_XDP
+ * sockets in multi-threaded environment. All threads are sharing a common
+ * buffer pool, with each socket having its own private buffer cache.
+ *
+ * Example 1: Single thread handling two sockets. The packets received by socket
+ * A (interface IFA, queue QA) are forwarded to socket B (interface IFB, queue
+ * QB), while the packets received by socket B are forwarded to socket A. The
+ * thread is running on CPU core X:
+ *
+ *         ./xsk_fwd -i IFA -q QA -i IFB -q QB -c X
+ *
+ * Example 2: Two threads, each handling two sockets. The thread running on CPU
+ * core X forwards all the packets received by socket A to socket B, and all the
+ * packets received by socket B to socket A. The thread running on CPU core Y is
+ * performing the same packet forwarding between sockets C and D:
+ *
+ *         ./xsk_fwd -i IFA -q QA -i IFB -q QB -i IFC -q QC -i IFD -q QD
+ *         -c CX -c CY
+ */
+
+/*
+ * Buffer pool and buffer cache
+ *
+ * For packet forwarding, the packet buffers are typically allocated from the
+ * pool for packet reception and freed back to the pool for further reuse once
+ * the packet transmission is completed.
+ *
+ * The buffer pool is shared between multiple threads. In order to minimize the
+ * access latency to the shared buffer pool, each thread creates one (or
+ * several) buffer caches, which, unlike the buffer pool, are private to the
+ * thread that creates them and therefore cannot be shared with other threads.
+ * The access to the shared pool is only needed either (A) when the cache gets
+ * empty due to repeated buffer allocations and it needs to be replenished from
+ * the pool, or (B) when the cache gets full due to repeated buffer free and it
+ * needs to be flushed back to the pull.
+ *
+ * In a packet forwarding system, a packet received on any input port can
+ * potentially be transmitted on any output port, depending on the forwarding
+ * configuration. For AF_XDP sockets, for this to work with zero-copy of the
+ * packet buffers when, it is required that the buffer pool memory fits into the
+ * UMEM area shared by all the sockets.
+ */
+
+struct bpool_params {
+	u32 n_buffers;
+	u32 buffer_size;
+	int mmap_flags;
+
+	u32 n_users_max;
+	u32 n_buffers_per_slab;
+};
+
+/* This buffer pool implementation organizes the buffers into equally sized
+ * slabs of *n_buffers_per_slab*. Initially, there are *n_slabs* slabs in the
+ * pool that are completely filled with buffer pointers (full slabs).
+ *
+ * Each buffer cache has a slab for buffer allocation and a slab for buffer
+ * free, with both of these slabs initially empty. When the cache's allocation
+ * slab goes empty, it is swapped with one of the available full slabs from the
+ * pool, if any is available. When the cache's free slab goes full, it is
+ * swapped for one of the empty slabs from the pool, which is guaranteed to
+ * succeed.
+ *
+ * Partially filled slabs never get traded between the cache and the pool
+ * (except when the cache itself is destroyed), which enables fast operation
+ * through pointer swapping.
+ */
+struct bpool {
+	struct bpool_params params;
+	pthread_mutex_t lock;
+	void *addr;
+
+	u64 **slabs;
+	u64 **slabs_reserved;
+	u64 *buffers;
+	u64 *buffers_reserved;
+
+	u64 n_slabs;
+	u64 n_slabs_reserved;
+	u64 n_buffers;
+
+	u64 n_slabs_available;
+	u64 n_slabs_reserved_available;
+
+	struct xsk_umem_config umem_cfg;
+	struct xsk_ring_prod umem_fq;
+	struct xsk_ring_cons umem_cq;
+	struct xsk_umem *umem;
+};
+
+static struct bpool *
+bpool_init(struct bpool_params *params,
+	   struct xsk_umem_config *umem_cfg)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	u64 n_slabs, n_slabs_reserved, n_buffers, n_buffers_reserved;
+	u64 slabs_size, slabs_reserved_size;
+	u64 buffers_size, buffers_reserved_size;
+	u64 total_size, i;
+	struct bpool *bp;
+	u8 *p;
+	int status;
+
+	/* mmap prep. */
+	if (setrlimit(RLIMIT_MEMLOCK, &r))
+		return NULL;
+
+	/* bpool internals dimensioning. */
+	n_slabs = (params->n_buffers + params->n_buffers_per_slab - 1) /
+		params->n_buffers_per_slab;
+	n_slabs_reserved = params->n_users_max * 2;
+	n_buffers = n_slabs * params->n_buffers_per_slab;
+	n_buffers_reserved = n_slabs_reserved * params->n_buffers_per_slab;
+
+	slabs_size = n_slabs * sizeof(u64 *);
+	slabs_reserved_size = n_slabs_reserved * sizeof(u64 *);
+	buffers_size = n_buffers * sizeof(u64);
+	buffers_reserved_size = n_buffers_reserved * sizeof(u64);
+
+	total_size = sizeof(struct bpool) +
+		slabs_size + slabs_reserved_size +
+		buffers_size + buffers_reserved_size;
+
+	/* bpool memory allocation. */
+	p = calloc(total_size, sizeof(u8));
+	if (!p)
+		return NULL;
+
+	/* bpool memory initialization. */
+	bp = (struct bpool *)p;
+	memcpy(&bp->params, params, sizeof(*params));
+	bp->params.n_buffers = n_buffers;
+
+	bp->slabs = (u64 **)&p[sizeof(struct bpool)];
+	bp->slabs_reserved = (u64 **)&p[sizeof(struct bpool) +
+		slabs_size];
+	bp->buffers = (u64 *)&p[sizeof(struct bpool) +
+		slabs_size + slabs_reserved_size];
+	bp->buffers_reserved = (u64 *)&p[sizeof(struct bpool) +
+		slabs_size + slabs_reserved_size + buffers_size];
+
+	bp->n_slabs = n_slabs;
+	bp->n_slabs_reserved = n_slabs_reserved;
+	bp->n_buffers = n_buffers;
+
+	for (i = 0; i < n_slabs; i++)
+		bp->slabs[i] = &bp->buffers[i * params->n_buffers_per_slab];
+	bp->n_slabs_available = n_slabs;
+
+	for (i = 0; i < n_slabs_reserved; i++)
+		bp->slabs_reserved[i] = &bp->buffers_reserved[i *
+			params->n_buffers_per_slab];
+	bp->n_slabs_reserved_available = n_slabs_reserved;
+
+	for (i = 0; i < n_buffers; i++)
+		bp->buffers[i] = i * params->buffer_size;
+
+	/* lock. */
+	status = pthread_mutex_init(&bp->lock, NULL);
+	if (status) {
+		free(p);
+		return NULL;
+	}
+
+	/* mmap. */
+	bp->addr = mmap(NULL,
+			n_buffers * params->buffer_size,
+			PROT_READ | PROT_WRITE,
+			MAP_PRIVATE | MAP_ANONYMOUS | params->mmap_flags,
+			-1,
+			0);
+	if (bp->addr == MAP_FAILED) {
+		pthread_mutex_destroy(&bp->lock);
+		free(p);
+		return NULL;
+	}
+
+	/* umem. */
+	status = xsk_umem__create(&bp->umem,
+				  bp->addr,
+				  bp->params.n_buffers * bp->params.buffer_size,
+				  &bp->umem_fq,
+				  &bp->umem_cq,
+				  umem_cfg);
+	if (status) {
+		munmap(bp->addr, bp->params.n_buffers * bp->params.buffer_size);
+		pthread_mutex_destroy(&bp->lock);
+		free(p);
+		return NULL;
+	}
+	memcpy(&bp->umem_cfg, umem_cfg, sizeof(*umem_cfg));
+
+	return bp;
+}
+
+static void
+bpool_free(struct bpool *bp)
+{
+	if (!bp)
+		return;
+
+	xsk_umem__delete(bp->umem);
+	munmap(bp->addr, bp->params.n_buffers * bp->params.buffer_size);
+	pthread_mutex_destroy(&bp->lock);
+	free(bp);
+}
+
+struct bcache {
+	struct bpool *bp;
+
+	u64 *slab_cons;
+	u64 *slab_prod;
+
+	u64 n_buffers_cons;
+	u64 n_buffers_prod;
+};
+
+static u32
+bcache_slab_size(struct bcache *bc)
+{
+	struct bpool *bp = bc->bp;
+
+	return bp->params.n_buffers_per_slab;
+}
+
+static struct bcache *
+bcache_init(struct bpool *bp)
+{
+	struct bcache *bc;
+
+	bc = calloc(1, sizeof(struct bcache));
+	if (!bc)
+		return NULL;
+
+	bc->bp = bp;
+	bc->n_buffers_cons = 0;
+	bc->n_buffers_prod = 0;
+
+	pthread_mutex_lock(&bp->lock);
+	if (bp->n_slabs_reserved_available == 0) {
+		pthread_mutex_unlock(&bp->lock);
+		free(bc);
+		return NULL;
+	}
+
+	bc->slab_cons = bp->slabs_reserved[bp->n_slabs_reserved_available - 1];
+	bc->slab_prod = bp->slabs_reserved[bp->n_slabs_reserved_available - 2];
+	bp->n_slabs_reserved_available -= 2;
+	pthread_mutex_unlock(&bp->lock);
+
+	return bc;
+}
+
+static void
+bcache_free(struct bcache *bc)
+{
+	struct bpool *bp;
+
+	if (!bc)
+		return;
+
+	/* In order to keep this example simple, the case of freeing any
+	 * existing buffers from the cache back to the pool is ignored.
+	 */
+
+	bp = bc->bp;
+	pthread_mutex_lock(&bp->lock);
+	bp->slabs_reserved[bp->n_slabs_reserved_available] = bc->slab_prod;
+	bp->slabs_reserved[bp->n_slabs_reserved_available + 1] = bc->slab_cons;
+	bp->n_slabs_reserved_available += 2;
+	pthread_mutex_unlock(&bp->lock);
+
+	free(bc);
+}
+
+/* To work correctly, the implementation requires that the *n_buffers* input
+ * argument is never greater than the buffer pool's *n_buffers_per_slab*. This
+ * is typically the case, with one exception taking place when large number of
+ * buffers are allocated at init time (e.g. for the UMEM fill queue setup).
+ */
+static inline u32
+bcache_cons_check(struct bcache *bc, u32 n_buffers)
+{
+	struct bpool *bp = bc->bp;
+	u64 n_buffers_per_slab = bp->params.n_buffers_per_slab;
+	u64 n_buffers_cons = bc->n_buffers_cons;
+	u64 n_slabs_available;
+	u64 *slab_full;
+
+	/*
+	 * Consumer slab is not empty: Use what's available locally. Do not
+	 * look for more buffers from the pool when the ask can only be
+	 * partially satisfied.
+	 */
+	if (n_buffers_cons)
+		return (n_buffers_cons < n_buffers) ?
+			n_buffers_cons :
+			n_buffers;
+
+	/*
+	 * Consumer slab is empty: look to trade the current consumer slab
+	 * (full) for a full slab from the pool, if any is available.
+	 */
+	pthread_mutex_lock(&bp->lock);
+	n_slabs_available = bp->n_slabs_available;
+	if (!n_slabs_available) {
+		pthread_mutex_unlock(&bp->lock);
+		return 0;
+	}
+
+	n_slabs_available--;
+	slab_full = bp->slabs[n_slabs_available];
+	bp->slabs[n_slabs_available] = bc->slab_cons;
+	bp->n_slabs_available = n_slabs_available;
+	pthread_mutex_unlock(&bp->lock);
+
+	bc->slab_cons = slab_full;
+	bc->n_buffers_cons = n_buffers_per_slab;
+	return n_buffers;
+}
+
+static inline u64
+bcache_cons(struct bcache *bc)
+{
+	u64 n_buffers_cons = bc->n_buffers_cons - 1;
+	u64 buffer;
+
+	buffer = bc->slab_cons[n_buffers_cons];
+	bc->n_buffers_cons = n_buffers_cons;
+	return buffer;
+}
+
+static inline void
+bcache_prod(struct bcache *bc, u64 buffer)
+{
+	struct bpool *bp = bc->bp;
+	u64 n_buffers_per_slab = bp->params.n_buffers_per_slab;
+	u64 n_buffers_prod = bc->n_buffers_prod;
+	u64 n_slabs_available;
+	u64 *slab_empty;
+
+	/*
+	 * Producer slab is not yet full: store the current buffer to it.
+	 */
+	if (n_buffers_prod < n_buffers_per_slab) {
+		bc->slab_prod[n_buffers_prod] = buffer;
+		bc->n_buffers_prod = n_buffers_prod + 1;
+		return;
+	}
+
+	/*
+	 * Producer slab is full: trade the cache's current producer slab
+	 * (full) for an empty slab from the pool, then store the current
+	 * buffer to the new producer slab. As one full slab exists in the
+	 * cache, it is guaranteed that there is at least one empty slab
+	 * available in the pool.
+	 */
+	pthread_mutex_lock(&bp->lock);
+	n_slabs_available = bp->n_slabs_available;
+	slab_empty = bp->slabs[n_slabs_available];
+	bp->slabs[n_slabs_available] = bc->slab_prod;
+	bp->n_slabs_available = n_slabs_available + 1;
+	pthread_mutex_unlock(&bp->lock);
+
+	slab_empty[0] = buffer;
+	bc->slab_prod = slab_empty;
+	bc->n_buffers_prod = 1;
+}
+
+/*
+ * Port
+ *
+ * Each of the forwarding ports sits on top of an AF_XDP socket. In order for
+ * packet forwarding to happen with no packet buffer copy, all the sockets need
+ * to share the same UMEM area, which is used as the buffer pool memory.
+ */
+#ifndef MAX_BURST_RX
+#define MAX_BURST_RX 64
+#endif
+
+#ifndef MAX_BURST_TX
+#define MAX_BURST_TX 64
+#endif
+
+struct burst_rx {
+	u64 addr[MAX_BURST_RX];
+	u32 len[MAX_BURST_RX];
+};
+
+struct burst_tx {
+	u64 addr[MAX_BURST_TX];
+	u32 len[MAX_BURST_TX];
+	u32 n_pkts;
+};
+
+struct port_params {
+	struct xsk_socket_config xsk_cfg;
+	struct bpool *bp;
+	const char *iface;
+	u32 iface_queue;
+};
+
+struct port {
+	struct port_params params;
+
+	struct bcache *bc;
+
+	struct xsk_ring_cons rxq;
+	struct xsk_ring_prod txq;
+	struct xsk_ring_prod umem_fq;
+	struct xsk_ring_cons umem_cq;
+	struct xsk_socket *xsk;
+	int umem_fq_initialized;
+
+	u64 n_pkts_rx;
+	u64 n_pkts_tx;
+};
+
+static void
+port_free(struct port *p)
+{
+	if (!p)
+		return;
+
+	/* To keep this example simple, the code to free the buffers from the
+	 * socket's receive and transmit queues, as well as from the UMEM fill
+	 * and completion queues, is not included.
+	 */
+
+	if (p->xsk)
+		xsk_socket__delete(p->xsk);
+
+	bcache_free(p->bc);
+
+	free(p);
+}
+
+static struct port *
+port_init(struct port_params *params)
+{
+	struct port *p;
+	u32 umem_fq_size, pos = 0;
+	int status, i;
+
+	/* Memory allocation and initialization. */
+	p = calloc(sizeof(struct port), 1);
+	if (!p)
+		return NULL;
+
+	memcpy(&p->params, params, sizeof(p->params));
+	umem_fq_size = params->bp->umem_cfg.fill_size;
+
+	/* bcache. */
+	p->bc = bcache_init(params->bp);
+	if (!p->bc ||
+	    (bcache_slab_size(p->bc) < umem_fq_size) ||
+	    (bcache_cons_check(p->bc, umem_fq_size) < umem_fq_size)) {
+		port_free(p);
+		return NULL;
+	}
+
+	/* xsk socket. */
+	status = xsk_socket__create_shared(&p->xsk,
+					   params->iface,
+					   params->iface_queue,
+					   params->bp->umem,
+					   &p->rxq,
+					   &p->txq,
+					   &p->umem_fq,
+					   &p->umem_cq,
+					   &params->xsk_cfg);
+	if (status) {
+		port_free(p);
+		return NULL;
+	}
+
+	/* umem fq. */
+	xsk_ring_prod__reserve(&p->umem_fq, umem_fq_size, &pos);
+
+	for (i = 0; i < umem_fq_size; i++)
+		*xsk_ring_prod__fill_addr(&p->umem_fq, pos + i) =
+			bcache_cons(p->bc);
+
+	xsk_ring_prod__submit(&p->umem_fq, umem_fq_size);
+	p->umem_fq_initialized = 1;
+
+	return p;
+}
+
+static inline u32
+port_rx_burst(struct port *p, struct burst_rx *b)
+{
+	u32 n_pkts, pos, i;
+
+	/* Free buffers for FQ replenish. */
+	n_pkts = ARRAY_SIZE(b->addr);
+
+	n_pkts = bcache_cons_check(p->bc, n_pkts);
+	if (!n_pkts)
+		return 0;
+
+	/* RXQ. */
+	n_pkts = xsk_ring_cons__peek(&p->rxq, n_pkts, &pos);
+	if (!n_pkts) {
+		if (xsk_ring_prod__needs_wakeup(&p->umem_fq)) {
+			struct pollfd pollfd = {
+				.fd = xsk_socket__fd(p->xsk),
+				.events = POLLIN,
+			};
+
+			poll(&pollfd, 1, 0);
+		}
+		return 0;
+	}
+
+	for (i = 0; i < n_pkts; i++) {
+		b->addr[i] = xsk_ring_cons__rx_desc(&p->rxq, pos + i)->addr;
+		b->len[i] = xsk_ring_cons__rx_desc(&p->rxq, pos + i)->len;
+	}
+
+	xsk_ring_cons__release(&p->rxq, n_pkts);
+	p->n_pkts_rx += n_pkts;
+
+	/* UMEM FQ. */
+	for ( ; ; ) {
+		int status;
+
+		status = xsk_ring_prod__reserve(&p->umem_fq, n_pkts, &pos);
+		if (status == n_pkts)
+			break;
+
+		if (xsk_ring_prod__needs_wakeup(&p->umem_fq)) {
+			struct pollfd pollfd = {
+				.fd = xsk_socket__fd(p->xsk),
+				.events = POLLIN,
+			};
+
+			poll(&pollfd, 1, 0);
+		}
+	}
+
+	for (i = 0; i < n_pkts; i++)
+		*xsk_ring_prod__fill_addr(&p->umem_fq, pos + i) =
+			bcache_cons(p->bc);
+
+	xsk_ring_prod__submit(&p->umem_fq, n_pkts);
+
+	return n_pkts;
+}
+
+static inline void
+port_tx_burst(struct port *p, struct burst_tx *b)
+{
+	u32 n_pkts, pos, i;
+	int status;
+
+	/* UMEM CQ. */
+	n_pkts = p->params.bp->umem_cfg.comp_size;
+
+	n_pkts = xsk_ring_cons__peek(&p->umem_cq, n_pkts, &pos);
+
+	for (i = 0; i < n_pkts; i++) {
+		u64 addr = *xsk_ring_cons__comp_addr(&p->umem_cq, pos + i);
+
+		bcache_prod(p->bc, addr);
+	}
+
+	xsk_ring_cons__release(&p->umem_cq, n_pkts);
+
+	/* TXQ. */
+	n_pkts = b->n_pkts;
+
+	for ( ; ; ) {
+		status = xsk_ring_prod__reserve(&p->txq, n_pkts, &pos);
+		if (status == n_pkts)
+			break;
+
+		if (xsk_ring_prod__needs_wakeup(&p->txq))
+			sendto(xsk_socket__fd(p->xsk), NULL, 0, MSG_DONTWAIT,
+			       NULL, 0);
+	}
+
+	for (i = 0; i < n_pkts; i++) {
+		xsk_ring_prod__tx_desc(&p->txq, pos + i)->addr = b->addr[i];
+		xsk_ring_prod__tx_desc(&p->txq, pos + i)->len = b->len[i];
+	}
+
+	xsk_ring_prod__submit(&p->txq, n_pkts);
+	if (xsk_ring_prod__needs_wakeup(&p->txq))
+		sendto(xsk_socket__fd(p->xsk), NULL, 0, MSG_DONTWAIT, NULL, 0);
+	p->n_pkts_tx += n_pkts;
+}
+
+/*
+ * Thread
+ *
+ * Packet forwarding threads.
+ */
+#ifndef MAX_PORTS_PER_THREAD
+#define MAX_PORTS_PER_THREAD 16
+#endif
+
+struct thread_data {
+	struct port *ports_rx[MAX_PORTS_PER_THREAD];
+	struct port *ports_tx[MAX_PORTS_PER_THREAD];
+	u32 n_ports_rx;
+	struct burst_rx burst_rx;
+	struct burst_tx burst_tx[MAX_PORTS_PER_THREAD];
+	u32 cpu_core_id;
+	int quit;
+};
+
+static void swap_mac_addresses(void *data)
+{
+	struct ether_header *eth = (struct ether_header *)data;
+	struct ether_addr *src_addr = (struct ether_addr *)&eth->ether_shost;
+	struct ether_addr *dst_addr = (struct ether_addr *)&eth->ether_dhost;
+	struct ether_addr tmp;
+
+	tmp = *src_addr;
+	*src_addr = *dst_addr;
+	*dst_addr = tmp;
+}
+
+static void *
+thread_func(void *arg)
+{
+	struct thread_data *t = arg;
+	cpu_set_t cpu_cores;
+	u32 i;
+
+	CPU_ZERO(&cpu_cores);
+	CPU_SET(t->cpu_core_id, &cpu_cores);
+	pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpu_cores);
+
+	for (i = 0; !t->quit; i = (i + 1) & (t->n_ports_rx - 1)) {
+		struct port *port_rx = t->ports_rx[i];
+		struct port *port_tx = t->ports_tx[i];
+		struct burst_rx *brx = &t->burst_rx;
+		struct burst_tx *btx = &t->burst_tx[i];
+		u32 n_pkts, j;
+
+		/* RX. */
+		n_pkts = port_rx_burst(port_rx, brx);
+		if (!n_pkts)
+			continue;
+
+		/* Process & TX. */
+		for (j = 0; j < n_pkts; j++) {
+			u64 addr = xsk_umem__add_offset_to_addr(brx->addr[j]);
+			u8 *pkt = xsk_umem__get_data(port_rx->params.bp->addr,
+						     addr);
+
+			swap_mac_addresses(pkt);
+
+			btx->addr[btx->n_pkts] = brx->addr[j];
+			btx->len[btx->n_pkts] = brx->len[j];
+			btx->n_pkts++;
+
+			if (btx->n_pkts == MAX_BURST_TX) {
+				port_tx_burst(port_tx, btx);
+				btx->n_pkts = 0;
+			}
+		}
+	}
+
+	return NULL;
+}
+
+/*
+ * Process
+ */
+static const struct bpool_params bpool_params_default = {
+	.n_buffers = 64 * 1024,
+	.buffer_size = XSK_UMEM__DEFAULT_FRAME_SIZE,
+	.mmap_flags = 0,
+
+	.n_users_max = 16,
+	.n_buffers_per_slab = XSK_RING_PROD__DEFAULT_NUM_DESCS * 2,
+};
+
+static const struct xsk_umem_config umem_cfg_default = {
+	.fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS * 2,
+	.comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS,
+	.frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE,
+	.frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM,
+	.flags = 0,
+};
+
+static const struct port_params port_params_default = {
+	.xsk_cfg = {
+		.rx_size = XSK_RING_CONS__DEFAULT_NUM_DESCS,
+		.tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS,
+		.libbpf_flags = 0,
+		.xdp_flags = XDP_FLAGS_DRV_MODE,
+		.bind_flags = XDP_USE_NEED_WAKEUP | XDP_ZEROCOPY,
+	},
+
+	.bp = NULL,
+	.iface = NULL,
+	.iface_queue = 0,
+};
+
+#ifndef MAX_PORTS
+#define MAX_PORTS 64
+#endif
+
+#ifndef MAX_THREADS
+#define MAX_THREADS 64
+#endif
+
+static struct bpool_params bpool_params;
+static struct xsk_umem_config umem_cfg;
+static struct bpool *bp;
+
+static struct port_params port_params[MAX_PORTS];
+static struct port *ports[MAX_PORTS];
+static u64 n_pkts_rx[MAX_PORTS];
+static u64 n_pkts_tx[MAX_PORTS];
+static int n_ports;
+
+static pthread_t threads[MAX_THREADS];
+static struct thread_data thread_data[MAX_THREADS];
+static int n_threads;
+
+static void
+print_usage(char *prog_name)
+{
+	const char *usage =
+		"Usage:\n"
+		"\t%s [ -b SIZE ] -c CORE -i INTERFACE [ -q QUEUE ]\n"
+		"\n"
+		"-c CORE        CPU core to run a packet forwarding thread\n"
+		"               on. May be invoked multiple times.\n"
+		"\n"
+		"-b SIZE        Number of buffers in the buffer pool shared\n"
+		"               by all the forwarding threads. Default: %u.\n"
+		"\n"
+		"-i INTERFACE   Network interface. Each (INTERFACE, QUEUE)\n"
+		"               pair specifies one forwarding port. May be\n"
+		"               invoked multiple times.\n"
+		"\n"
+		"-q QUEUE       Network interface queue for RX and TX. Each\n"
+		"               (INTERFACE, QUEUE) pair specified one\n"
+		"               forwarding port. Default: %u. May be invoked\n"
+		"               multiple times.\n"
+		"\n";
+	printf(usage,
+	       prog_name,
+	       bpool_params_default.n_buffers,
+	       port_params_default.iface_queue);
+}
+
+static int
+parse_args(int argc, char **argv)
+{
+	struct option lgopts[] = {
+		{ NULL,  0, 0, 0 }
+	};
+	int opt, option_index;
+
+	/* Parse the input arguments. */
+	for ( ; ;) {
+		opt = getopt_long(argc, argv, "c:i:q:", lgopts, &option_index);
+		if (opt == EOF)
+			break;
+
+		switch (opt) {
+		case 'b':
+			bpool_params.n_buffers = atoi(optarg);
+			break;
+
+		case 'c':
+			if (n_threads == MAX_THREADS) {
+				printf("Max number of threads (%d) reached.\n",
+				       MAX_THREADS);
+				return -1;
+			}
+
+			thread_data[n_threads].cpu_core_id = atoi(optarg);
+			n_threads++;
+			break;
+
+		case 'i':
+			if (n_ports == MAX_PORTS) {
+				printf("Max number of ports (%d) reached.\n",
+				       MAX_PORTS);
+				return -1;
+			}
+
+			port_params[n_ports].iface = optarg;
+			port_params[n_ports].iface_queue = 0;
+			n_ports++;
+			break;
+
+		case 'q':
+			if (n_ports == 0) {
+				printf("No port specified for queue.\n");
+				return -1;
+			}
+			port_params[n_ports - 1].iface_queue = atoi(optarg);
+			break;
+
+		default:
+			printf("Illegal argument.\n");
+			return -1;
+		}
+	}
+
+	optind = 1; /* reset getopt lib */
+
+	/* Check the input arguments. */
+	if (!n_ports) {
+		printf("No ports specified.\n");
+		return -1;
+	}
+
+	if (!n_threads) {
+		printf("No threads specified.\n");
+		return -1;
+	}
+
+	if (n_ports % n_threads) {
+		printf("Ports cannot be evenly distributed to threads.\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+static void
+print_port(u32 port_id)
+{
+	struct port *port = ports[port_id];
+
+	printf("Port %u: interface = %s, queue = %u\n",
+	       port_id, port->params.iface, port->params.iface_queue);
+}
+
+static void
+print_thread(u32 thread_id)
+{
+	struct thread_data *t = &thread_data[thread_id];
+	u32 i;
+
+	printf("Thread %u (CPU core %u): ",
+	       thread_id, t->cpu_core_id);
+
+	for (i = 0; i < t->n_ports_rx; i++) {
+		struct port *port_rx = t->ports_rx[i];
+		struct port *port_tx = t->ports_tx[i];
+
+		printf("(%s, %u) -> (%s, %u), ",
+		       port_rx->params.iface,
+		       port_rx->params.iface_queue,
+		       port_tx->params.iface,
+		       port_tx->params.iface_queue);
+	}
+
+	printf("\n");
+}
+
+static void
+print_port_stats_separator(void)
+{
+	printf("+-%4s-+-%12s-+-%13s-+-%12s-+-%13s-+\n",
+	       "----",
+	       "------------",
+	       "-------------",
+	       "------------",
+	       "-------------");
+}
+
+static void
+print_port_stats_header(void)
+{
+	print_port_stats_separator();
+	printf("| %4s | %12s | %13s | %12s | %13s |\n",
+	       "Port",
+	       "RX packets",
+	       "RX rate (pps)",
+	       "TX packets",
+	       "TX_rate (pps)");
+	print_port_stats_separator();
+}
+
+static void
+print_port_stats_trailer(void)
+{
+	print_port_stats_separator();
+	printf("\n");
+}
+
+static void
+print_port_stats(int port_id, u64 ns_diff)
+{
+	struct port *p = ports[port_id];
+	double rx_pps, tx_pps;
+
+	rx_pps = (p->n_pkts_rx - n_pkts_rx[port_id]) * 1000000000. / ns_diff;
+	tx_pps = (p->n_pkts_tx - n_pkts_tx[port_id]) * 1000000000. / ns_diff;
+
+	printf("| %4d | %12llu | %13.0f | %12llu | %13.0f |\n",
+	       port_id,
+	       p->n_pkts_rx,
+	       rx_pps,
+	       p->n_pkts_tx,
+	       tx_pps);
+
+	n_pkts_rx[port_id] = p->n_pkts_rx;
+	n_pkts_tx[port_id] = p->n_pkts_tx;
+}
+
+static void
+print_port_stats_all(u64 ns_diff)
+{
+	int i;
+
+	print_port_stats_header();
+	for (i = 0; i < n_ports; i++)
+		print_port_stats(i, ns_diff);
+	print_port_stats_trailer();
+}
+
+static int quit;
+
+static void
+signal_handler(int sig)
+{
+	quit = 1;
+}
+
+static void remove_xdp_program(void)
+{
+	int i;
+
+	for (i = 0 ; i < n_ports; i++)
+		bpf_set_link_xdp_fd(if_nametoindex(port_params[i].iface), -1,
+				    port_params[i].xsk_cfg.xdp_flags);
+}
+
+int main(int argc, char **argv)
+{
+	struct timespec time;
+	u64 ns0;
+	int i;
+
+	/* Parse args. */
+	memcpy(&bpool_params, &bpool_params_default,
+	       sizeof(struct bpool_params));
+	memcpy(&umem_cfg, &umem_cfg_default,
+	       sizeof(struct xsk_umem_config));
+	for (i = 0; i < MAX_PORTS; i++)
+		memcpy(&port_params[i], &port_params_default,
+		       sizeof(struct port_params));
+
+	if (parse_args(argc, argv)) {
+		print_usage(argv[0]);
+		return -1;
+	}
+
+	/* Buffer pool initialization. */
+	bp = bpool_init(&bpool_params, &umem_cfg);
+	if (!bp) {
+		printf("Buffer pool initialization failed.\n");
+		return -1;
+	}
+	printf("Buffer pool created successfully.\n");
+
+	/* Ports initialization. */
+	for (i = 0; i < MAX_PORTS; i++)
+		port_params[i].bp = bp;
+
+	for (i = 0; i < n_ports; i++) {
+		ports[i] = port_init(&port_params[i]);
+		if (!ports[i]) {
+			printf("Port %d initialization failed.\n", i);
+			return -1;
+		}
+		print_port(i);
+	}
+	printf("All ports created successfully.\n");
+
+	/* Threads. */
+	for (i = 0; i < n_threads; i++) {
+		struct thread_data *t = &thread_data[i];
+		u32 n_ports_per_thread = n_ports / n_threads, j;
+
+		for (j = 0; j < n_ports_per_thread; j++) {
+			t->ports_rx[j] = ports[i * n_ports_per_thread + j];
+			t->ports_tx[j] = ports[i * n_ports_per_thread +
+				(j + 1) % n_ports_per_thread];
+		}
+
+		t->n_ports_rx = n_ports_per_thread;
+
+		print_thread(i);
+	}
+
+	for (i = 0; i < n_threads; i++) {
+		int status;
+
+		status = pthread_create(&threads[i],
+					NULL,
+					thread_func,
+					&thread_data[i]);
+		if (status) {
+			printf("Thread %d creation failed.\n", i);
+			return -1;
+		}
+	}
+	printf("All threads created successfully.\n");
+
+	/* Print statistics. */
+	signal(SIGINT, signal_handler);
+	signal(SIGTERM, signal_handler);
+	signal(SIGABRT, signal_handler);
+
+	clock_gettime(CLOCK_MONOTONIC, &time);
+	ns0 = time.tv_sec * 1000000000UL + time.tv_nsec;
+	for ( ; !quit; ) {
+		u64 ns1, ns_diff;
+
+		sleep(1);
+		clock_gettime(CLOCK_MONOTONIC, &time);
+		ns1 = time.tv_sec * 1000000000UL + time.tv_nsec;
+		ns_diff = ns1 - ns0;
+		ns0 = ns1;
+
+		print_port_stats_all(ns_diff);
+	}
+
+	/* Threads completion. */
+	printf("Quit.\n");
+	for (i = 0; i < n_threads; i++)
+		thread_data[i].quit = 1;
+
+	for (i = 0; i < n_threads; i++)
+		pthread_join(threads[i], NULL);
+
+	for (i = 0; i < n_ports; i++)
+		port_free(ports[i]);
+
+	bpool_free(bp);
+
+	remove_xdp_program();
+
+	return 0;
+}