diff options
Diffstat (limited to 'tools/testing/selftests/bpf/xsk.c')
| -rw-r--r-- | tools/testing/selftests/bpf/xsk.c | 1268 |
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 000000000000..0b3ff49c740d --- /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); +} |