diff options
Diffstat (limited to 'tools/lib/bpf/xsk.c')
| -rw-r--r-- | tools/lib/bpf/xsk.c | 83 |
1 files changed, 79 insertions, 4 deletions
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index e3e41ceeb1bc..ffbb588724d8 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -46,6 +46,11 @@ #define PF_XDP AF_XDP #endif +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; @@ -351,6 +356,54 @@ int xsk_umem__create_v0_0_2(struct xsk_umem **umem_ptr, void *umem_area, COMPAT_VERSION(xsk_umem__create_v0_0_2, xsk_umem__create, LIBBPF_0.0.2) DEFAULT_VERSION(xsk_umem__create_v0_0_4, xsk_umem__create, LIBBPF_0.0.4) +static enum xsk_prog get_xsk_prog(void) +{ + enum xsk_prog detected = XSK_PROG_FALLBACK; + struct bpf_load_program_attr prog_attr; + struct bpf_create_map_attr map_attr; + __u32 size_out, retval, duration; + 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(), + }; + int prog_fd, map_fd, ret; + + memset(&map_attr, 0, sizeof(map_attr)); + map_attr.map_type = BPF_MAP_TYPE_XSKMAP; + map_attr.key_size = sizeof(int); + map_attr.value_size = sizeof(int); + map_attr.max_entries = 1; + + map_fd = bpf_create_map_xattr(&map_attr); + if (map_fd < 0) + return detected; + + insns[0].imm = map_fd; + + memset(&prog_attr, 0, sizeof(prog_attr)); + prog_attr.prog_type = BPF_PROG_TYPE_XDP; + prog_attr.insns = insns; + prog_attr.insns_cnt = ARRAY_SIZE(insns); + prog_attr.license = "GPL"; + + prog_fd = bpf_load_program_xattr(&prog_attr, NULL, 0); + if (prog_fd < 0) { + close(map_fd); + return detected; + } + + ret = bpf_prog_test_run(prog_fd, 0, &data_in, 1, &data_out, &size_out, &retval, &duration); + if (!ret && 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; @@ -358,7 +411,7 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk) char log_buf[log_buf_size]; int err, prog_fd; - /* This is the C-program: + /* This is the fallback C-program: * SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx) * { * int ret, index = ctx->rx_queue_index; @@ -414,9 +467,31 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk) /* The jumps are to this instruction */ BPF_EXIT_INSN(), }; - size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn); - prog_fd = bpf_load_program(BPF_PROG_TYPE_XDP, prog, insns_cnt, + /* 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[] = {sizeof(prog) / sizeof(struct bpf_insn), + sizeof(prog_redirect_flags) / sizeof(struct bpf_insn), + }; + struct bpf_insn *progs[] = {prog, prog_redirect_flags}; + enum xsk_prog option = get_xsk_prog(); + + prog_fd = bpf_load_program(BPF_PROG_TYPE_XDP, progs[option], insns_cnt[option], "LGPL-2.1 or BSD-2-Clause", 0, log_buf, log_buf_size); if (prog_fd < 0) { @@ -442,7 +517,7 @@ static int xsk_get_max_queues(struct xsk_socket *xsk) struct ifreq ifr = {}; int fd, err, ret; - fd = socket(AF_INET, SOCK_DGRAM, 0); + fd = socket(AF_LOCAL, SOCK_DGRAM, 0); if (fd < 0) return -errno; |