diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/lib/bpf/libbpf_probes.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/lib/bpf/libbpf_probes.c')
-rw-r--r-- | tools/lib/bpf/libbpf_probes.c | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c new file mode 100644 index 000000000..13393f0ea --- /dev/null +++ b/tools/lib/bpf/libbpf_probes.c @@ -0,0 +1,359 @@ +// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) +/* Copyright (c) 2019 Netronome Systems, Inc. */ + +#include <errno.h> +#include <fcntl.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> +#include <net/if.h> +#include <sys/utsname.h> + +#include <linux/btf.h> +#include <linux/filter.h> +#include <linux/kernel.h> + +#include "bpf.h" +#include "libbpf.h" +#include "libbpf_internal.h" + +static bool grep(const char *buffer, const char *pattern) +{ + return !!strstr(buffer, pattern); +} + +static int get_vendor_id(int ifindex) +{ + char ifname[IF_NAMESIZE], path[64], buf[8]; + ssize_t len; + int fd; + + if (!if_indextoname(ifindex, ifname)) + return -1; + + snprintf(path, sizeof(path), "/sys/class/net/%s/device/vendor", ifname); + + fd = open(path, O_RDONLY); + if (fd < 0) + return -1; + + len = read(fd, buf, sizeof(buf)); + close(fd); + if (len < 0) + return -1; + if (len >= (ssize_t)sizeof(buf)) + return -1; + buf[len] = '\0'; + + return strtol(buf, NULL, 0); +} + +static int get_kernel_version(void) +{ + int version, subversion, patchlevel; + struct utsname utsn; + + /* Return 0 on failure, and attempt to probe with empty kversion */ + if (uname(&utsn)) + return 0; + + if (sscanf(utsn.release, "%d.%d.%d", + &version, &subversion, &patchlevel) != 3) + return 0; + + return (version << 16) + (subversion << 8) + patchlevel; +} + +static void +probe_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, + size_t insns_cnt, char *buf, size_t buf_len, __u32 ifindex) +{ + struct bpf_load_program_attr xattr = {}; + int fd; + + switch (prog_type) { + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: + xattr.expected_attach_type = BPF_CGROUP_INET4_CONNECT; + break; + case BPF_PROG_TYPE_CGROUP_SOCKOPT: + xattr.expected_attach_type = BPF_CGROUP_GETSOCKOPT; + break; + case BPF_PROG_TYPE_SK_LOOKUP: + xattr.expected_attach_type = BPF_SK_LOOKUP; + break; + case BPF_PROG_TYPE_KPROBE: + xattr.kern_version = get_kernel_version(); + break; + case BPF_PROG_TYPE_UNSPEC: + case BPF_PROG_TYPE_SOCKET_FILTER: + case BPF_PROG_TYPE_SCHED_CLS: + case BPF_PROG_TYPE_SCHED_ACT: + case BPF_PROG_TYPE_TRACEPOINT: + case BPF_PROG_TYPE_XDP: + case BPF_PROG_TYPE_PERF_EVENT: + case BPF_PROG_TYPE_CGROUP_SKB: + case BPF_PROG_TYPE_CGROUP_SOCK: + case BPF_PROG_TYPE_LWT_IN: + case BPF_PROG_TYPE_LWT_OUT: + case BPF_PROG_TYPE_LWT_XMIT: + case BPF_PROG_TYPE_SOCK_OPS: + case BPF_PROG_TYPE_SK_SKB: + case BPF_PROG_TYPE_CGROUP_DEVICE: + case BPF_PROG_TYPE_SK_MSG: + case BPF_PROG_TYPE_RAW_TRACEPOINT: + case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: + case BPF_PROG_TYPE_LWT_SEG6LOCAL: + case BPF_PROG_TYPE_LIRC_MODE2: + case BPF_PROG_TYPE_SK_REUSEPORT: + case BPF_PROG_TYPE_FLOW_DISSECTOR: + case BPF_PROG_TYPE_CGROUP_SYSCTL: + case BPF_PROG_TYPE_TRACING: + case BPF_PROG_TYPE_STRUCT_OPS: + case BPF_PROG_TYPE_EXT: + case BPF_PROG_TYPE_LSM: + default: + break; + } + + xattr.prog_type = prog_type; + xattr.insns = insns; + xattr.insns_cnt = insns_cnt; + xattr.license = "GPL"; + xattr.prog_ifindex = ifindex; + + fd = bpf_load_program_xattr(&xattr, buf, buf_len); + if (fd >= 0) + close(fd); +} + +bool bpf_probe_prog_type(enum bpf_prog_type prog_type, __u32 ifindex) +{ + struct bpf_insn insns[2] = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN() + }; + + if (ifindex && prog_type == BPF_PROG_TYPE_SCHED_CLS) + /* nfp returns -EINVAL on exit(0) with TC offload */ + insns[0].imm = 2; + + errno = 0; + probe_load(prog_type, insns, ARRAY_SIZE(insns), NULL, 0, ifindex); + + return errno != EINVAL && errno != EOPNOTSUPP; +} + +int libbpf__load_raw_btf(const char *raw_types, size_t types_len, + const char *str_sec, size_t str_len) +{ + struct btf_header hdr = { + .magic = BTF_MAGIC, + .version = BTF_VERSION, + .hdr_len = sizeof(struct btf_header), + .type_len = types_len, + .str_off = types_len, + .str_len = str_len, + }; + int btf_fd, btf_len; + __u8 *raw_btf; + + btf_len = hdr.hdr_len + hdr.type_len + hdr.str_len; + raw_btf = malloc(btf_len); + if (!raw_btf) + return -ENOMEM; + + memcpy(raw_btf, &hdr, sizeof(hdr)); + memcpy(raw_btf + hdr.hdr_len, raw_types, hdr.type_len); + memcpy(raw_btf + hdr.hdr_len + hdr.type_len, str_sec, hdr.str_len); + + btf_fd = bpf_load_btf(raw_btf, btf_len, NULL, 0, false); + + free(raw_btf); + return btf_fd; +} + +static int load_local_storage_btf(void) +{ + const char strs[] = "\0bpf_spin_lock\0val\0cnt\0l"; + /* struct bpf_spin_lock { + * int val; + * }; + * struct val { + * int cnt; + * struct bpf_spin_lock l; + * }; + */ + __u32 types[] = { + /* int */ + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + /* struct bpf_spin_lock */ /* [2] */ + BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 1), 4), + BTF_MEMBER_ENC(15, 1, 0), /* int val; */ + /* struct val */ /* [3] */ + BTF_TYPE_ENC(15, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 2), 8), + BTF_MEMBER_ENC(19, 1, 0), /* int cnt; */ + BTF_MEMBER_ENC(23, 2, 32),/* struct bpf_spin_lock l; */ + }; + + return libbpf__load_raw_btf((char *)types, sizeof(types), + strs, sizeof(strs)); +} + +bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex) +{ + int key_size, value_size, max_entries, map_flags; + __u32 btf_key_type_id = 0, btf_value_type_id = 0; + struct bpf_create_map_attr attr = {}; + int fd = -1, btf_fd = -1, fd_inner; + + key_size = sizeof(__u32); + value_size = sizeof(__u32); + max_entries = 1; + map_flags = 0; + + switch (map_type) { + case BPF_MAP_TYPE_STACK_TRACE: + value_size = sizeof(__u64); + break; + case BPF_MAP_TYPE_LPM_TRIE: + key_size = sizeof(__u64); + value_size = sizeof(__u64); + map_flags = BPF_F_NO_PREALLOC; + break; + case BPF_MAP_TYPE_CGROUP_STORAGE: + case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: + key_size = sizeof(struct bpf_cgroup_storage_key); + value_size = sizeof(__u64); + max_entries = 0; + break; + case BPF_MAP_TYPE_QUEUE: + case BPF_MAP_TYPE_STACK: + key_size = 0; + break; + case BPF_MAP_TYPE_SK_STORAGE: + case BPF_MAP_TYPE_INODE_STORAGE: + btf_key_type_id = 1; + btf_value_type_id = 3; + value_size = 8; + max_entries = 0; + map_flags = BPF_F_NO_PREALLOC; + btf_fd = load_local_storage_btf(); + if (btf_fd < 0) + return false; + break; + case BPF_MAP_TYPE_RINGBUF: + key_size = 0; + value_size = 0; + max_entries = sysconf(_SC_PAGE_SIZE); + break; + case BPF_MAP_TYPE_UNSPEC: + case BPF_MAP_TYPE_HASH: + case BPF_MAP_TYPE_ARRAY: + case BPF_MAP_TYPE_PROG_ARRAY: + case BPF_MAP_TYPE_PERF_EVENT_ARRAY: + case BPF_MAP_TYPE_PERCPU_HASH: + case BPF_MAP_TYPE_PERCPU_ARRAY: + case BPF_MAP_TYPE_CGROUP_ARRAY: + case BPF_MAP_TYPE_LRU_HASH: + case BPF_MAP_TYPE_LRU_PERCPU_HASH: + case BPF_MAP_TYPE_ARRAY_OF_MAPS: + case BPF_MAP_TYPE_HASH_OF_MAPS: + case BPF_MAP_TYPE_DEVMAP: + case BPF_MAP_TYPE_DEVMAP_HASH: + case BPF_MAP_TYPE_SOCKMAP: + case BPF_MAP_TYPE_CPUMAP: + case BPF_MAP_TYPE_XSKMAP: + case BPF_MAP_TYPE_SOCKHASH: + case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: + case BPF_MAP_TYPE_STRUCT_OPS: + default: + break; + } + + if (map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS || + map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { + /* TODO: probe for device, once libbpf has a function to create + * map-in-map for offload + */ + if (ifindex) + return false; + + fd_inner = bpf_create_map(BPF_MAP_TYPE_HASH, + sizeof(__u32), sizeof(__u32), 1, 0); + if (fd_inner < 0) + return false; + fd = bpf_create_map_in_map(map_type, NULL, sizeof(__u32), + fd_inner, 1, 0); + close(fd_inner); + } else { + /* Note: No other restriction on map type probes for offload */ + attr.map_type = map_type; + attr.key_size = key_size; + attr.value_size = value_size; + attr.max_entries = max_entries; + attr.map_flags = map_flags; + attr.map_ifindex = ifindex; + if (btf_fd >= 0) { + attr.btf_fd = btf_fd; + attr.btf_key_type_id = btf_key_type_id; + attr.btf_value_type_id = btf_value_type_id; + } + + fd = bpf_create_map_xattr(&attr); + } + if (fd >= 0) + close(fd); + if (btf_fd >= 0) + close(btf_fd); + + return fd >= 0; +} + +bool bpf_probe_helper(enum bpf_func_id id, enum bpf_prog_type prog_type, + __u32 ifindex) +{ + struct bpf_insn insns[2] = { + BPF_EMIT_CALL(id), + BPF_EXIT_INSN() + }; + char buf[4096] = {}; + bool res; + + probe_load(prog_type, insns, ARRAY_SIZE(insns), buf, sizeof(buf), + ifindex); + res = !grep(buf, "invalid func ") && !grep(buf, "unknown func "); + + if (ifindex) { + switch (get_vendor_id(ifindex)) { + case 0x19ee: /* Netronome specific */ + res = res && !grep(buf, "not supported by FW") && + !grep(buf, "unsupported function id"); + break; + default: + break; + } + } + + return res; +} + +/* + * Probe for availability of kernel commit (5.3): + * + * c04c0d2b968a ("bpf: increase complexity limit and maximum program size") + */ +bool bpf_probe_large_insn_limit(__u32 ifindex) +{ + struct bpf_insn insns[BPF_MAXINSNS + 1]; + int i; + + for (i = 0; i < BPF_MAXINSNS; i++) + insns[i] = BPF_MOV64_IMM(BPF_REG_0, 1); + insns[BPF_MAXINSNS] = BPF_EXIT_INSN(); + + errno = 0; + probe_load(BPF_PROG_TYPE_SCHED_CLS, insns, ARRAY_SIZE(insns), NULL, 0, + ifindex); + + return errno != E2BIG && errno != EINVAL; +} |