summaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/bpf/xsk.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/testing/selftests/bpf/xsk.c')
-rw-r--r--tools/testing/selftests/bpf/xsk.c1268
1 files changed, 1268 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/xsk.c b/tools/testing/selftests/bpf/xsk.c
new file mode 100644
index 000000000..0b3ff49c7
--- /dev/null
+++ b/tools/testing/selftests/bpf/xsk.c
@@ -0,0 +1,1268 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+
+/*
+ * AF_XDP user-space access library.
+ *
+ * Copyright(c) 2018 - 2019 Intel Corporation.
+ *
+ * Author(s): Magnus Karlsson <magnus.karlsson@intel.com>
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <asm/barrier.h>
+#include <linux/compiler.h>
+#include <linux/ethtool.h>
+#include <linux/filter.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_xdp.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/sockios.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <linux/if_link.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "xsk.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 pr_warn(fmt, ...) fprintf(stderr, fmt, ##__VA_ARGS__)
+
+enum xsk_prog {
+ XSK_PROG_FALLBACK,
+ XSK_PROG_REDIRECT_FLAGS,
+};
+
+struct xsk_umem {
+ struct xsk_ring_prod *fill_save;
+ struct xsk_ring_cons *comp_save;
+ char *umem_area;
+ struct xsk_umem_config config;
+ int fd;
+ int refcount;
+ struct list_head ctx_list;
+ bool rx_ring_setup_done;
+ bool tx_ring_setup_done;
+};
+
+struct xsk_ctx {
+ struct xsk_ring_prod *fill;
+ struct xsk_ring_cons *comp;
+ __u32 queue_id;
+ struct xsk_umem *umem;
+ int refcount;
+ int ifindex;
+ struct list_head list;
+ int prog_fd;
+ int link_fd;
+ int xsks_map_fd;
+ char ifname[IFNAMSIZ];
+ bool has_bpf_link;
+};
+
+struct xsk_socket {
+ struct xsk_ring_cons *rx;
+ struct xsk_ring_prod *tx;
+ __u64 outstanding_tx;
+ struct xsk_ctx *ctx;
+ struct xsk_socket_config config;
+ int fd;
+};
+
+struct xsk_nl_info {
+ bool xdp_prog_attached;
+ int ifindex;
+ int fd;
+};
+
+/* Up until and including Linux 5.3 */
+struct xdp_ring_offset_v1 {
+ __u64 producer;
+ __u64 consumer;
+ __u64 desc;
+};
+
+/* Up until and including Linux 5.3 */
+struct xdp_mmap_offsets_v1 {
+ struct xdp_ring_offset_v1 rx;
+ struct xdp_ring_offset_v1 tx;
+ struct xdp_ring_offset_v1 fr;
+ struct xdp_ring_offset_v1 cr;
+};
+
+int xsk_umem__fd(const struct xsk_umem *umem)
+{
+ return umem ? umem->fd : -EINVAL;
+}
+
+int xsk_socket__fd(const struct xsk_socket *xsk)
+{
+ return xsk ? xsk->fd : -EINVAL;
+}
+
+static bool xsk_page_aligned(void *buffer)
+{
+ unsigned long addr = (unsigned long)buffer;
+
+ return !(addr & (getpagesize() - 1));
+}
+
+static void xsk_set_umem_config(struct xsk_umem_config *cfg,
+ const struct xsk_umem_config *usr_cfg)
+{
+ if (!usr_cfg) {
+ cfg->fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
+ cfg->comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
+ cfg->frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
+ cfg->frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM;
+ cfg->flags = XSK_UMEM__DEFAULT_FLAGS;
+ return;
+ }
+
+ cfg->fill_size = usr_cfg->fill_size;
+ cfg->comp_size = usr_cfg->comp_size;
+ cfg->frame_size = usr_cfg->frame_size;
+ cfg->frame_headroom = usr_cfg->frame_headroom;
+ cfg->flags = usr_cfg->flags;
+}
+
+static int xsk_set_xdp_socket_config(struct xsk_socket_config *cfg,
+ const struct xsk_socket_config *usr_cfg)
+{
+ if (!usr_cfg) {
+ cfg->rx_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
+ cfg->tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
+ cfg->libbpf_flags = 0;
+ cfg->xdp_flags = 0;
+ cfg->bind_flags = 0;
+ return 0;
+ }
+
+ if (usr_cfg->libbpf_flags & ~XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)
+ return -EINVAL;
+
+ cfg->rx_size = usr_cfg->rx_size;
+ cfg->tx_size = usr_cfg->tx_size;
+ cfg->libbpf_flags = usr_cfg->libbpf_flags;
+ cfg->xdp_flags = usr_cfg->xdp_flags;
+ cfg->bind_flags = usr_cfg->bind_flags;
+
+ return 0;
+}
+
+static void xsk_mmap_offsets_v1(struct xdp_mmap_offsets *off)
+{
+ struct xdp_mmap_offsets_v1 off_v1;
+
+ /* getsockopt on a kernel <= 5.3 has no flags fields.
+ * Copy over the offsets to the correct places in the >=5.4 format
+ * and put the flags where they would have been on that kernel.
+ */
+ memcpy(&off_v1, off, sizeof(off_v1));
+
+ off->rx.producer = off_v1.rx.producer;
+ off->rx.consumer = off_v1.rx.consumer;
+ off->rx.desc = off_v1.rx.desc;
+ off->rx.flags = off_v1.rx.consumer + sizeof(__u32);
+
+ off->tx.producer = off_v1.tx.producer;
+ off->tx.consumer = off_v1.tx.consumer;
+ off->tx.desc = off_v1.tx.desc;
+ off->tx.flags = off_v1.tx.consumer + sizeof(__u32);
+
+ off->fr.producer = off_v1.fr.producer;
+ off->fr.consumer = off_v1.fr.consumer;
+ off->fr.desc = off_v1.fr.desc;
+ off->fr.flags = off_v1.fr.consumer + sizeof(__u32);
+
+ off->cr.producer = off_v1.cr.producer;
+ off->cr.consumer = off_v1.cr.consumer;
+ off->cr.desc = off_v1.cr.desc;
+ off->cr.flags = off_v1.cr.consumer + sizeof(__u32);
+}
+
+static int xsk_get_mmap_offsets(int fd, struct xdp_mmap_offsets *off)
+{
+ socklen_t optlen;
+ int err;
+
+ optlen = sizeof(*off);
+ err = getsockopt(fd, SOL_XDP, XDP_MMAP_OFFSETS, off, &optlen);
+ if (err)
+ return err;
+
+ if (optlen == sizeof(*off))
+ return 0;
+
+ if (optlen == sizeof(struct xdp_mmap_offsets_v1)) {
+ xsk_mmap_offsets_v1(off);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int xsk_create_umem_rings(struct xsk_umem *umem, int fd,
+ struct xsk_ring_prod *fill,
+ struct xsk_ring_cons *comp)
+{
+ struct xdp_mmap_offsets off;
+ void *map;
+ int err;
+
+ err = setsockopt(fd, SOL_XDP, XDP_UMEM_FILL_RING,
+ &umem->config.fill_size,
+ sizeof(umem->config.fill_size));
+ if (err)
+ return -errno;
+
+ err = setsockopt(fd, SOL_XDP, XDP_UMEM_COMPLETION_RING,
+ &umem->config.comp_size,
+ sizeof(umem->config.comp_size));
+ if (err)
+ return -errno;
+
+ err = xsk_get_mmap_offsets(fd, &off);
+ if (err)
+ return -errno;
+
+ map = mmap(NULL, off.fr.desc + umem->config.fill_size * sizeof(__u64),
+ PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd,
+ XDP_UMEM_PGOFF_FILL_RING);
+ if (map == MAP_FAILED)
+ return -errno;
+
+ fill->mask = umem->config.fill_size - 1;
+ fill->size = umem->config.fill_size;
+ fill->producer = map + off.fr.producer;
+ fill->consumer = map + off.fr.consumer;
+ fill->flags = map + off.fr.flags;
+ fill->ring = map + off.fr.desc;
+ fill->cached_cons = umem->config.fill_size;
+
+ map = mmap(NULL, off.cr.desc + umem->config.comp_size * sizeof(__u64),
+ PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd,
+ XDP_UMEM_PGOFF_COMPLETION_RING);
+ if (map == MAP_FAILED) {
+ err = -errno;
+ goto out_mmap;
+ }
+
+ comp->mask = umem->config.comp_size - 1;
+ comp->size = umem->config.comp_size;
+ comp->producer = map + off.cr.producer;
+ comp->consumer = map + off.cr.consumer;
+ comp->flags = map + off.cr.flags;
+ comp->ring = map + off.cr.desc;
+
+ return 0;
+
+out_mmap:
+ munmap(map, off.fr.desc + umem->config.fill_size * sizeof(__u64));
+ return err;
+}
+
+int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area,
+ __u64 size, struct xsk_ring_prod *fill,
+ struct xsk_ring_cons *comp,
+ const struct xsk_umem_config *usr_config)
+{
+ struct xdp_umem_reg mr;
+ struct xsk_umem *umem;
+ int err;
+
+ if (!umem_area || !umem_ptr || !fill || !comp)
+ return -EFAULT;
+ if (!size && !xsk_page_aligned(umem_area))
+ return -EINVAL;
+
+ umem = calloc(1, sizeof(*umem));
+ if (!umem)
+ return -ENOMEM;
+
+ umem->fd = socket(AF_XDP, SOCK_RAW | SOCK_CLOEXEC, 0);
+ if (umem->fd < 0) {
+ err = -errno;
+ goto out_umem_alloc;
+ }
+
+ umem->umem_area = umem_area;
+ INIT_LIST_HEAD(&umem->ctx_list);
+ xsk_set_umem_config(&umem->config, usr_config);
+
+ memset(&mr, 0, sizeof(mr));
+ mr.addr = (uintptr_t)umem_area;
+ mr.len = size;
+ mr.chunk_size = umem->config.frame_size;
+ mr.headroom = umem->config.frame_headroom;
+ mr.flags = umem->config.flags;
+
+ err = setsockopt(umem->fd, SOL_XDP, XDP_UMEM_REG, &mr, sizeof(mr));
+ if (err) {
+ err = -errno;
+ goto out_socket;
+ }
+
+ err = xsk_create_umem_rings(umem, umem->fd, fill, comp);
+ if (err)
+ goto out_socket;
+
+ umem->fill_save = fill;
+ umem->comp_save = comp;
+ *umem_ptr = umem;
+ return 0;
+
+out_socket:
+ close(umem->fd);
+out_umem_alloc:
+ free(umem);
+ return err;
+}
+
+struct xsk_umem_config_v1 {
+ __u32 fill_size;
+ __u32 comp_size;
+ __u32 frame_size;
+ __u32 frame_headroom;
+};
+
+static enum xsk_prog get_xsk_prog(void)
+{
+ enum xsk_prog detected = XSK_PROG_FALLBACK;
+ char data_in = 0, data_out;
+ struct bpf_insn insns[] = {
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_MOV64_IMM(BPF_REG_3, XDP_PASS),
+ BPF_EMIT_CALL(BPF_FUNC_redirect_map),
+ BPF_EXIT_INSN(),
+ };
+ LIBBPF_OPTS(bpf_test_run_opts, opts,
+ .data_in = &data_in,
+ .data_size_in = 1,
+ .data_out = &data_out,
+ );
+
+ int prog_fd, map_fd, ret, insn_cnt = ARRAY_SIZE(insns);
+
+ map_fd = bpf_map_create(BPF_MAP_TYPE_XSKMAP, NULL, sizeof(int), sizeof(int), 1, NULL);
+ if (map_fd < 0)
+ return detected;
+
+ insns[0].imm = map_fd;
+
+ prog_fd = bpf_prog_load(BPF_PROG_TYPE_XDP, NULL, "GPL", insns, insn_cnt, NULL);
+ if (prog_fd < 0) {
+ close(map_fd);
+ return detected;
+ }
+
+ ret = bpf_prog_test_run_opts(prog_fd, &opts);
+ if (!ret && opts.retval == XDP_PASS)
+ detected = XSK_PROG_REDIRECT_FLAGS;
+ close(prog_fd);
+ close(map_fd);
+ return detected;
+}
+
+static int xsk_load_xdp_prog(struct xsk_socket *xsk)
+{
+ static const int log_buf_size = 16 * 1024;
+ struct xsk_ctx *ctx = xsk->ctx;
+ char log_buf[log_buf_size];
+ int prog_fd;
+
+ /* This is the fallback C-program:
+ * SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
+ * {
+ * int ret, index = ctx->rx_queue_index;
+ *
+ * // A set entry here means that the correspnding queue_id
+ * // has an active AF_XDP socket bound to it.
+ * ret = bpf_redirect_map(&xsks_map, index, XDP_PASS);
+ * if (ret > 0)
+ * return ret;
+ *
+ * // Fallback for pre-5.3 kernels, not supporting default
+ * // action in the flags parameter.
+ * if (bpf_map_lookup_elem(&xsks_map, &index))
+ * return bpf_redirect_map(&xsks_map, index, 0);
+ * return XDP_PASS;
+ * }
+ */
+ struct bpf_insn prog[] = {
+ /* r2 = *(u32 *)(r1 + 16) */
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 16),
+ /* *(u32 *)(r10 - 4) = r2 */
+ BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_2, -4),
+ /* r1 = xskmap[] */
+ BPF_LD_MAP_FD(BPF_REG_1, ctx->xsks_map_fd),
+ /* r3 = XDP_PASS */
+ BPF_MOV64_IMM(BPF_REG_3, 2),
+ /* call bpf_redirect_map */
+ BPF_EMIT_CALL(BPF_FUNC_redirect_map),
+ /* if w0 != 0 goto pc+13 */
+ BPF_JMP32_IMM(BPF_JSGT, BPF_REG_0, 0, 13),
+ /* r2 = r10 */
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ /* r2 += -4 */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
+ /* r1 = xskmap[] */
+ BPF_LD_MAP_FD(BPF_REG_1, ctx->xsks_map_fd),
+ /* call bpf_map_lookup_elem */
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ /* r1 = r0 */
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ /* r0 = XDP_PASS */
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ /* if r1 == 0 goto pc+5 */
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 5),
+ /* r2 = *(u32 *)(r10 - 4) */
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_10, -4),
+ /* r1 = xskmap[] */
+ BPF_LD_MAP_FD(BPF_REG_1, ctx->xsks_map_fd),
+ /* r3 = 0 */
+ BPF_MOV64_IMM(BPF_REG_3, 0),
+ /* call bpf_redirect_map */
+ BPF_EMIT_CALL(BPF_FUNC_redirect_map),
+ /* The jumps are to this instruction */
+ BPF_EXIT_INSN(),
+ };
+
+ /* This is the post-5.3 kernel C-program:
+ * SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
+ * {
+ * return bpf_redirect_map(&xsks_map, ctx->rx_queue_index, XDP_PASS);
+ * }
+ */
+ struct bpf_insn prog_redirect_flags[] = {
+ /* r2 = *(u32 *)(r1 + 16) */
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 16),
+ /* r1 = xskmap[] */
+ BPF_LD_MAP_FD(BPF_REG_1, ctx->xsks_map_fd),
+ /* r3 = XDP_PASS */
+ BPF_MOV64_IMM(BPF_REG_3, 2),
+ /* call bpf_redirect_map */
+ BPF_EMIT_CALL(BPF_FUNC_redirect_map),
+ BPF_EXIT_INSN(),
+ };
+ size_t insns_cnt[] = {ARRAY_SIZE(prog),
+ ARRAY_SIZE(prog_redirect_flags),
+ };
+ struct bpf_insn *progs[] = {prog, prog_redirect_flags};
+ enum xsk_prog option = get_xsk_prog();
+ LIBBPF_OPTS(bpf_prog_load_opts, opts,
+ .log_buf = log_buf,
+ .log_size = log_buf_size,
+ );
+
+ prog_fd = bpf_prog_load(BPF_PROG_TYPE_XDP, NULL, "LGPL-2.1 or BSD-2-Clause",
+ progs[option], insns_cnt[option], &opts);
+ if (prog_fd < 0) {
+ pr_warn("BPF log buffer:\n%s", log_buf);
+ return prog_fd;
+ }
+
+ ctx->prog_fd = prog_fd;
+ return 0;
+}
+
+static int xsk_create_bpf_link(struct xsk_socket *xsk)
+{
+ DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts);
+ struct xsk_ctx *ctx = xsk->ctx;
+ __u32 prog_id = 0;
+ int link_fd;
+ int err;
+
+ err = bpf_xdp_query_id(ctx->ifindex, xsk->config.xdp_flags, &prog_id);
+ if (err) {
+ pr_warn("getting XDP prog id failed\n");
+ return err;
+ }
+
+ /* if there's a netlink-based XDP prog loaded on interface, bail out
+ * and ask user to do the removal by himself
+ */
+ if (prog_id) {
+ pr_warn("Netlink-based XDP prog detected, please unload it in order to launch AF_XDP prog\n");
+ return -EINVAL;
+ }
+
+ opts.flags = xsk->config.xdp_flags & ~(XDP_FLAGS_UPDATE_IF_NOEXIST | XDP_FLAGS_REPLACE);
+
+ link_fd = bpf_link_create(ctx->prog_fd, ctx->ifindex, BPF_XDP, &opts);
+ if (link_fd < 0) {
+ pr_warn("bpf_link_create failed: %s\n", strerror(errno));
+ return link_fd;
+ }
+
+ ctx->link_fd = link_fd;
+ return 0;
+}
+
+/* Copy up to sz - 1 bytes from zero-terminated src string and ensure that dst
+ * is zero-terminated string no matter what (unless sz == 0, in which case
+ * it's a no-op). It's conceptually close to FreeBSD's strlcpy(), but differs
+ * in what is returned. Given this is internal helper, it's trivial to extend
+ * this, when necessary. Use this instead of strncpy inside libbpf source code.
+ */
+static inline void libbpf_strlcpy(char *dst, const char *src, size_t sz)
+{
+ size_t i;
+
+ if (sz == 0)
+ return;
+
+ sz--;
+ for (i = 0; i < sz && src[i]; i++)
+ dst[i] = src[i];
+ dst[i] = '\0';
+}
+
+static int xsk_get_max_queues(struct xsk_socket *xsk)
+{
+ struct ethtool_channels channels = { .cmd = ETHTOOL_GCHANNELS };
+ struct xsk_ctx *ctx = xsk->ctx;
+ struct ifreq ifr = {};
+ int fd, err, ret;
+
+ fd = socket(AF_LOCAL, SOCK_DGRAM | SOCK_CLOEXEC, 0);
+ if (fd < 0)
+ return -errno;
+
+ ifr.ifr_data = (void *)&channels;
+ libbpf_strlcpy(ifr.ifr_name, ctx->ifname, IFNAMSIZ);
+ err = ioctl(fd, SIOCETHTOOL, &ifr);
+ if (err && errno != EOPNOTSUPP) {
+ ret = -errno;
+ goto out;
+ }
+
+ if (err) {
+ /* If the device says it has no channels, then all traffic
+ * is sent to a single stream, so max queues = 1.
+ */
+ ret = 1;
+ } else {
+ /* Take the max of rx, tx, combined. Drivers return
+ * the number of channels in different ways.
+ */
+ ret = max(channels.max_rx, channels.max_tx);
+ ret = max(ret, (int)channels.max_combined);
+ }
+
+out:
+ close(fd);
+ return ret;
+}
+
+static int xsk_create_bpf_maps(struct xsk_socket *xsk)
+{
+ struct xsk_ctx *ctx = xsk->ctx;
+ int max_queues;
+ int fd;
+
+ max_queues = xsk_get_max_queues(xsk);
+ if (max_queues < 0)
+ return max_queues;
+
+ fd = bpf_map_create(BPF_MAP_TYPE_XSKMAP, "xsks_map",
+ sizeof(int), sizeof(int), max_queues, NULL);
+ if (fd < 0)
+ return fd;
+
+ ctx->xsks_map_fd = fd;
+
+ return 0;
+}
+
+static void xsk_delete_bpf_maps(struct xsk_socket *xsk)
+{
+ struct xsk_ctx *ctx = xsk->ctx;
+
+ bpf_map_delete_elem(ctx->xsks_map_fd, &ctx->queue_id);
+ close(ctx->xsks_map_fd);
+}
+
+static int xsk_lookup_bpf_maps(struct xsk_socket *xsk)
+{
+ __u32 i, *map_ids, num_maps, prog_len = sizeof(struct bpf_prog_info);
+ __u32 map_len = sizeof(struct bpf_map_info);
+ struct bpf_prog_info prog_info = {};
+ struct xsk_ctx *ctx = xsk->ctx;
+ struct bpf_map_info map_info;
+ int fd, err;
+
+ err = bpf_obj_get_info_by_fd(ctx->prog_fd, &prog_info, &prog_len);
+ if (err)
+ return err;
+
+ num_maps = prog_info.nr_map_ids;
+
+ map_ids = calloc(prog_info.nr_map_ids, sizeof(*map_ids));
+ if (!map_ids)
+ return -ENOMEM;
+
+ memset(&prog_info, 0, prog_len);
+ prog_info.nr_map_ids = num_maps;
+ prog_info.map_ids = (__u64)(unsigned long)map_ids;
+
+ err = bpf_obj_get_info_by_fd(ctx->prog_fd, &prog_info, &prog_len);
+ if (err)
+ goto out_map_ids;
+
+ ctx->xsks_map_fd = -1;
+
+ for (i = 0; i < prog_info.nr_map_ids; i++) {
+ fd = bpf_map_get_fd_by_id(map_ids[i]);
+ if (fd < 0)
+ continue;
+
+ memset(&map_info, 0, map_len);
+ err = bpf_obj_get_info_by_fd(fd, &map_info, &map_len);
+ if (err) {
+ close(fd);
+ continue;
+ }
+
+ if (!strncmp(map_info.name, "xsks_map", sizeof(map_info.name))) {
+ ctx->xsks_map_fd = fd;
+ break;
+ }
+
+ close(fd);
+ }
+
+ if (ctx->xsks_map_fd == -1)
+ err = -ENOENT;
+
+out_map_ids:
+ free(map_ids);
+ return err;
+}
+
+static int xsk_set_bpf_maps(struct xsk_socket *xsk)
+{
+ struct xsk_ctx *ctx = xsk->ctx;
+
+ return bpf_map_update_elem(ctx->xsks_map_fd, &ctx->queue_id,
+ &xsk->fd, 0);
+}
+
+static int xsk_link_lookup(int ifindex, __u32 *prog_id, int *link_fd)
+{
+ struct bpf_link_info link_info;
+ __u32 link_len;
+ __u32 id = 0;
+ int err;
+ int fd;
+
+ while (true) {
+ err = bpf_link_get_next_id(id, &id);
+ if (err) {
+ if (errno == ENOENT) {
+ err = 0;
+ break;
+ }
+ pr_warn("can't get next link: %s\n", strerror(errno));
+ break;
+ }
+
+ fd = bpf_link_get_fd_by_id(id);
+ if (fd < 0) {
+ if (errno == ENOENT)
+ continue;
+ pr_warn("can't get link by id (%u): %s\n", id, strerror(errno));
+ err = -errno;
+ break;
+ }
+
+ link_len = sizeof(struct bpf_link_info);
+ memset(&link_info, 0, link_len);
+ err = bpf_obj_get_info_by_fd(fd, &link_info, &link_len);
+ if (err) {
+ pr_warn("can't get link info: %s\n", strerror(errno));
+ close(fd);
+ break;
+ }
+ if (link_info.type == BPF_LINK_TYPE_XDP) {
+ if (link_info.xdp.ifindex == ifindex) {
+ *link_fd = fd;
+ if (prog_id)
+ *prog_id = link_info.prog_id;
+ break;
+ }
+ }
+ close(fd);
+ }
+
+ return err;
+}
+
+static bool xsk_probe_bpf_link(void)
+{
+ LIBBPF_OPTS(bpf_link_create_opts, opts, .flags = XDP_FLAGS_SKB_MODE);
+ struct bpf_insn insns[2] = {
+ BPF_MOV64_IMM(BPF_REG_0, XDP_PASS),
+ BPF_EXIT_INSN()
+ };
+ int prog_fd, link_fd = -1, insn_cnt = ARRAY_SIZE(insns);
+ int ifindex_lo = 1;
+ bool ret = false;
+ int err;
+
+ err = xsk_link_lookup(ifindex_lo, NULL, &link_fd);
+ if (err)
+ return ret;
+
+ if (link_fd >= 0)
+ return true;
+
+ prog_fd = bpf_prog_load(BPF_PROG_TYPE_XDP, NULL, "GPL", insns, insn_cnt, NULL);
+ if (prog_fd < 0)
+ return ret;
+
+ link_fd = bpf_link_create(prog_fd, ifindex_lo, BPF_XDP, &opts);
+ close(prog_fd);
+
+ if (link_fd >= 0) {
+ ret = true;
+ close(link_fd);
+ }
+
+ return ret;
+}
+
+static int xsk_create_xsk_struct(int ifindex, struct xsk_socket *xsk)
+{
+ char ifname[IFNAMSIZ];
+ struct xsk_ctx *ctx;
+ char *interface;
+
+ ctx = calloc(1, sizeof(*ctx));
+ if (!ctx)
+ return -ENOMEM;
+
+ interface = if_indextoname(ifindex, &ifname[0]);
+ if (!interface) {
+ free(ctx);
+ return -errno;
+ }
+
+ ctx->ifindex = ifindex;
+ libbpf_strlcpy(ctx->ifname, ifname, IFNAMSIZ);
+
+ xsk->ctx = ctx;
+ xsk->ctx->has_bpf_link = xsk_probe_bpf_link();
+
+ return 0;
+}
+
+static int xsk_init_xdp_res(struct xsk_socket *xsk,
+ int *xsks_map_fd)
+{
+ struct xsk_ctx *ctx = xsk->ctx;
+ int err;
+
+ err = xsk_create_bpf_maps(xsk);
+ if (err)
+ return err;
+
+ err = xsk_load_xdp_prog(xsk);
+ if (err)
+ goto err_load_xdp_prog;
+
+ if (ctx->has_bpf_link)
+ err = xsk_create_bpf_link(xsk);
+ else
+ err = bpf_xdp_attach(xsk->ctx->ifindex, ctx->prog_fd,
+ xsk->config.xdp_flags, NULL);
+
+ if (err)
+ goto err_attach_xdp_prog;
+
+ if (!xsk->rx)
+ return err;
+
+ err = xsk_set_bpf_maps(xsk);
+ if (err)
+ goto err_set_bpf_maps;
+
+ return err;
+
+err_set_bpf_maps:
+ if (ctx->has_bpf_link)
+ close(ctx->link_fd);
+ else
+ bpf_xdp_detach(ctx->ifindex, 0, NULL);
+err_attach_xdp_prog:
+ close(ctx->prog_fd);
+err_load_xdp_prog:
+ xsk_delete_bpf_maps(xsk);
+ return err;
+}
+
+static int xsk_lookup_xdp_res(struct xsk_socket *xsk, int *xsks_map_fd, int prog_id)
+{
+ struct xsk_ctx *ctx = xsk->ctx;
+ int err;
+
+ ctx->prog_fd = bpf_prog_get_fd_by_id(prog_id);
+ if (ctx->prog_fd < 0) {
+ err = -errno;
+ goto err_prog_fd;
+ }
+ err = xsk_lookup_bpf_maps(xsk);
+ if (err)
+ goto err_lookup_maps;
+
+ if (!xsk->rx)
+ return err;
+
+ err = xsk_set_bpf_maps(xsk);
+ if (err)
+ goto err_set_maps;
+
+ return err;
+
+err_set_maps:
+ close(ctx->xsks_map_fd);
+err_lookup_maps:
+ close(ctx->prog_fd);
+err_prog_fd:
+ if (ctx->has_bpf_link)
+ close(ctx->link_fd);
+ return err;
+}
+
+static int __xsk_setup_xdp_prog(struct xsk_socket *_xdp, int *xsks_map_fd)
+{
+ struct xsk_socket *xsk = _xdp;
+ struct xsk_ctx *ctx = xsk->ctx;
+ __u32 prog_id = 0;
+ int err;
+
+ if (ctx->has_bpf_link)
+ err = xsk_link_lookup(ctx->ifindex, &prog_id, &ctx->link_fd);
+ else
+ err = bpf_xdp_query_id(ctx->ifindex, xsk->config.xdp_flags, &prog_id);
+
+ if (err)
+ return err;
+
+ err = !prog_id ? xsk_init_xdp_res(xsk, xsks_map_fd) :
+ xsk_lookup_xdp_res(xsk, xsks_map_fd, prog_id);
+
+ if (!err && xsks_map_fd)
+ *xsks_map_fd = ctx->xsks_map_fd;
+
+ return err;
+}
+
+int xsk_setup_xdp_prog_xsk(struct xsk_socket *xsk, int *xsks_map_fd)
+{
+ return __xsk_setup_xdp_prog(xsk, xsks_map_fd);
+}
+
+static struct xsk_ctx *xsk_get_ctx(struct xsk_umem *umem, int ifindex,
+ __u32 queue_id)
+{
+ struct xsk_ctx *ctx;
+
+ if (list_empty(&umem->ctx_list))
+ return NULL;
+
+ list_for_each_entry(ctx, &umem->ctx_list, list) {
+ if (ctx->ifindex == ifindex && ctx->queue_id == queue_id) {
+ ctx->refcount++;
+ return ctx;
+ }
+ }
+
+ return NULL;
+}
+
+static void xsk_put_ctx(struct xsk_ctx *ctx, bool unmap)
+{
+ struct xsk_umem *umem = ctx->umem;
+ struct xdp_mmap_offsets off;
+ int err;
+
+ if (--ctx->refcount)
+ return;
+
+ if (!unmap)
+ goto out_free;
+
+ err = xsk_get_mmap_offsets(umem->fd, &off);
+ if (err)
+ goto out_free;
+
+ munmap(ctx->fill->ring - off.fr.desc, off.fr.desc + umem->config.fill_size *
+ sizeof(__u64));
+ munmap(ctx->comp->ring - off.cr.desc, off.cr.desc + umem->config.comp_size *
+ sizeof(__u64));
+
+out_free:
+ list_del(&ctx->list);
+ free(ctx);
+}
+
+static struct xsk_ctx *xsk_create_ctx(struct xsk_socket *xsk,
+ struct xsk_umem *umem, int ifindex,
+ const char *ifname, __u32 queue_id,
+ struct xsk_ring_prod *fill,
+ struct xsk_ring_cons *comp)
+{
+ struct xsk_ctx *ctx;
+ int err;
+
+ ctx = calloc(1, sizeof(*ctx));
+ if (!ctx)
+ return NULL;
+
+ if (!umem->fill_save) {
+ err = xsk_create_umem_rings(umem, xsk->fd, fill, comp);
+ if (err) {
+ free(ctx);
+ return NULL;
+ }
+ } else if (umem->fill_save != fill || umem->comp_save != comp) {
+ /* Copy over rings to new structs. */
+ memcpy(fill, umem->fill_save, sizeof(*fill));
+ memcpy(comp, umem->comp_save, sizeof(*comp));
+ }
+
+ ctx->ifindex = ifindex;
+ ctx->refcount = 1;
+ ctx->umem = umem;
+ ctx->queue_id = queue_id;
+ libbpf_strlcpy(ctx->ifname, ifname, IFNAMSIZ);
+
+ ctx->fill = fill;
+ ctx->comp = comp;
+ list_add(&ctx->list, &umem->ctx_list);
+ ctx->has_bpf_link = xsk_probe_bpf_link();
+ return ctx;
+}
+
+static void xsk_destroy_xsk_struct(struct xsk_socket *xsk)
+{
+ free(xsk->ctx);
+ free(xsk);
+}
+
+int xsk_socket__update_xskmap(struct xsk_socket *xsk, int fd)
+{
+ xsk->ctx->xsks_map_fd = fd;
+ return xsk_set_bpf_maps(xsk);
+}
+
+int xsk_setup_xdp_prog(int ifindex, int *xsks_map_fd)
+{
+ struct xsk_socket *xsk;
+ int res;
+
+ xsk = calloc(1, sizeof(*xsk));
+ if (!xsk)
+ return -ENOMEM;
+
+ res = xsk_create_xsk_struct(ifindex, xsk);
+ if (res) {
+ free(xsk);
+ return -EINVAL;
+ }
+
+ res = __xsk_setup_xdp_prog(xsk, xsks_map_fd);
+
+ xsk_destroy_xsk_struct(xsk);
+
+ return res;
+}
+
+int xsk_socket__create_shared(struct xsk_socket **xsk_ptr,
+ const char *ifname,
+ __u32 queue_id, struct xsk_umem *umem,
+ struct xsk_ring_cons *rx,
+ struct xsk_ring_prod *tx,
+ struct xsk_ring_prod *fill,
+ struct xsk_ring_cons *comp,
+ const struct xsk_socket_config *usr_config)
+{
+ bool unmap, rx_setup_done = false, tx_setup_done = false;
+ void *rx_map = NULL, *tx_map = NULL;
+ struct sockaddr_xdp sxdp = {};
+ struct xdp_mmap_offsets off;
+ struct xsk_socket *xsk;
+ struct xsk_ctx *ctx;
+ int err, ifindex;
+
+ if (!umem || !xsk_ptr || !(rx || tx))
+ return -EFAULT;
+
+ unmap = umem->fill_save != fill;
+
+ xsk = calloc(1, sizeof(*xsk));
+ if (!xsk)
+ return -ENOMEM;
+
+ err = xsk_set_xdp_socket_config(&xsk->config, usr_config);
+ if (err)
+ goto out_xsk_alloc;
+
+ xsk->outstanding_tx = 0;
+ ifindex = if_nametoindex(ifname);
+ if (!ifindex) {
+ err = -errno;
+ goto out_xsk_alloc;
+ }
+
+ if (umem->refcount++ > 0) {
+ xsk->fd = socket(AF_XDP, SOCK_RAW | SOCK_CLOEXEC, 0);
+ if (xsk->fd < 0) {
+ err = -errno;
+ goto out_xsk_alloc;
+ }
+ } else {
+ xsk->fd = umem->fd;
+ rx_setup_done = umem->rx_ring_setup_done;
+ tx_setup_done = umem->tx_ring_setup_done;
+ }
+
+ ctx = xsk_get_ctx(umem, ifindex, queue_id);
+ if (!ctx) {
+ if (!fill || !comp) {
+ err = -EFAULT;
+ goto out_socket;
+ }
+
+ ctx = xsk_create_ctx(xsk, umem, ifindex, ifname, queue_id,
+ fill, comp);
+ if (!ctx) {
+ err = -ENOMEM;
+ goto out_socket;
+ }
+ }
+ xsk->ctx = ctx;
+
+ if (rx && !rx_setup_done) {
+ err = setsockopt(xsk->fd, SOL_XDP, XDP_RX_RING,
+ &xsk->config.rx_size,
+ sizeof(xsk->config.rx_size));
+ if (err) {
+ err = -errno;
+ goto out_put_ctx;
+ }
+ if (xsk->fd == umem->fd)
+ umem->rx_ring_setup_done = true;
+ }
+ if (tx && !tx_setup_done) {
+ err = setsockopt(xsk->fd, SOL_XDP, XDP_TX_RING,
+ &xsk->config.tx_size,
+ sizeof(xsk->config.tx_size));
+ if (err) {
+ err = -errno;
+ goto out_put_ctx;
+ }
+ if (xsk->fd == umem->fd)
+ umem->tx_ring_setup_done = true;
+ }
+
+ err = xsk_get_mmap_offsets(xsk->fd, &off);
+ if (err) {
+ err = -errno;
+ goto out_put_ctx;
+ }
+
+ if (rx) {
+ rx_map = mmap(NULL, off.rx.desc +
+ xsk->config.rx_size * sizeof(struct xdp_desc),
+ PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
+ xsk->fd, XDP_PGOFF_RX_RING);
+ if (rx_map == MAP_FAILED) {
+ err = -errno;
+ goto out_put_ctx;
+ }
+
+ rx->mask = xsk->config.rx_size - 1;
+ rx->size = xsk->config.rx_size;
+ rx->producer = rx_map + off.rx.producer;
+ rx->consumer = rx_map + off.rx.consumer;
+ rx->flags = rx_map + off.rx.flags;
+ rx->ring = rx_map + off.rx.desc;
+ rx->cached_prod = *rx->producer;
+ rx->cached_cons = *rx->consumer;
+ }
+ xsk->rx = rx;
+
+ if (tx) {
+ tx_map = mmap(NULL, off.tx.desc +
+ xsk->config.tx_size * sizeof(struct xdp_desc),
+ PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
+ xsk->fd, XDP_PGOFF_TX_RING);
+ if (tx_map == MAP_FAILED) {
+ err = -errno;
+ goto out_mmap_rx;
+ }
+
+ tx->mask = xsk->config.tx_size - 1;
+ tx->size = xsk->config.tx_size;
+ tx->producer = tx_map + off.tx.producer;
+ tx->consumer = tx_map + off.tx.consumer;
+ tx->flags = tx_map + off.tx.flags;
+ tx->ring = tx_map + off.tx.desc;
+ tx->cached_prod = *tx->producer;
+ /* cached_cons is r->size bigger than the real consumer pointer
+ * See xsk_prod_nb_free
+ */
+ tx->cached_cons = *tx->consumer + xsk->config.tx_size;
+ }
+ xsk->tx = tx;
+
+ sxdp.sxdp_family = PF_XDP;
+ sxdp.sxdp_ifindex = ctx->ifindex;
+ sxdp.sxdp_queue_id = ctx->queue_id;
+ if (umem->refcount > 1) {
+ sxdp.sxdp_flags |= XDP_SHARED_UMEM;
+ sxdp.sxdp_shared_umem_fd = umem->fd;
+ } else {
+ sxdp.sxdp_flags = xsk->config.bind_flags;
+ }
+
+ err = bind(xsk->fd, (struct sockaddr *)&sxdp, sizeof(sxdp));
+ if (err) {
+ err = -errno;
+ goto out_mmap_tx;
+ }
+
+ if (!(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) {
+ err = __xsk_setup_xdp_prog(xsk, NULL);
+ if (err)
+ goto out_mmap_tx;
+ }
+
+ *xsk_ptr = xsk;
+ umem->fill_save = NULL;
+ umem->comp_save = NULL;
+ return 0;
+
+out_mmap_tx:
+ if (tx)
+ munmap(tx_map, off.tx.desc +
+ xsk->config.tx_size * sizeof(struct xdp_desc));
+out_mmap_rx:
+ if (rx)
+ munmap(rx_map, off.rx.desc +
+ xsk->config.rx_size * sizeof(struct xdp_desc));
+out_put_ctx:
+ xsk_put_ctx(ctx, unmap);
+out_socket:
+ if (--umem->refcount)
+ close(xsk->fd);
+out_xsk_alloc:
+ free(xsk);
+ return err;
+}
+
+int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname,
+ __u32 queue_id, struct xsk_umem *umem,
+ struct xsk_ring_cons *rx, struct xsk_ring_prod *tx,
+ const struct xsk_socket_config *usr_config)
+{
+ if (!umem)
+ return -EFAULT;
+
+ return xsk_socket__create_shared(xsk_ptr, ifname, queue_id, umem,
+ rx, tx, umem->fill_save,
+ umem->comp_save, usr_config);
+}
+
+int xsk_umem__delete(struct xsk_umem *umem)
+{
+ struct xdp_mmap_offsets off;
+ int err;
+
+ if (!umem)
+ return 0;
+
+ if (umem->refcount)
+ return -EBUSY;
+
+ err = xsk_get_mmap_offsets(umem->fd, &off);
+ if (!err && umem->fill_save && umem->comp_save) {
+ munmap(umem->fill_save->ring - off.fr.desc,
+ off.fr.desc + umem->config.fill_size * sizeof(__u64));
+ munmap(umem->comp_save->ring - off.cr.desc,
+ off.cr.desc + umem->config.comp_size * sizeof(__u64));
+ }
+
+ close(umem->fd);
+ free(umem);
+
+ return 0;
+}
+
+void xsk_socket__delete(struct xsk_socket *xsk)
+{
+ size_t desc_sz = sizeof(struct xdp_desc);
+ struct xdp_mmap_offsets off;
+ struct xsk_umem *umem;
+ struct xsk_ctx *ctx;
+ int err;
+
+ if (!xsk)
+ return;
+
+ ctx = xsk->ctx;
+ umem = ctx->umem;
+
+ if (ctx->refcount == 1) {
+ xsk_delete_bpf_maps(xsk);
+ close(ctx->prog_fd);
+ if (ctx->has_bpf_link)
+ close(ctx->link_fd);
+ }
+
+ xsk_put_ctx(ctx, true);
+
+ err = xsk_get_mmap_offsets(xsk->fd, &off);
+ if (!err) {
+ if (xsk->rx) {
+ munmap(xsk->rx->ring - off.rx.desc,
+ off.rx.desc + xsk->config.rx_size * desc_sz);
+ }
+ if (xsk->tx) {
+ munmap(xsk->tx->ring - off.tx.desc,
+ off.tx.desc + xsk->config.tx_size * desc_sz);
+ }
+ }
+
+ umem->refcount--;
+ /* Do not close an fd that also has an associated umem connected
+ * to it.
+ */
+ if (xsk->fd != umem->fd)
+ close(xsk->fd);
+ free(xsk);
+}