From 10a13bb40e541d8cb1d5f36403aae3a0f1a2ee58 Mon Sep 17 00:00:00 2001 From: Jonathan Lemon Date: Thu, 6 Jun 2019 13:59:43 -0700 Subject: [PATCH] libbpf: remove qidconf and better support external bpf programs. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Use the recent change to XSKMAP bpf_map_lookup_elem() to test if there is a xsk present in the map instead of duplicating the work with qidconf. Fix things so callers using XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD bypass any internal bpf maps, so xsk_socket__{create|delete} works properly. Clean up error handling path. Signed-off-by: Jonathan Lemon Acked-by: Song Liu Tested-by: Björn Töpel Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/xsk.c | 103 ++++++++++++-------------------------------- 1 file changed, 28 insertions(+), 75 deletions(-) diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index 38667b62f1fe..7ef6293b4fd7 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -60,10 +60,8 @@ struct xsk_socket { struct xsk_umem *umem; struct xsk_socket_config config; int fd; - int xsks_map; int ifindex; int prog_fd; - int qidconf_map_fd; int xsks_map_fd; __u32 queue_id; char ifname[IFNAMSIZ]; @@ -265,15 +263,11 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk) /* This is the C-program: * SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx) * { - * int *qidconf, index = ctx->rx_queue_index; + * int index = ctx->rx_queue_index; * * // A set entry here means that the correspnding queue_id * // has an active AF_XDP socket bound to it. - * qidconf = bpf_map_lookup_elem(&qidconf_map, &index); - * if (!qidconf) - * return XDP_ABORTED; - * - * if (*qidconf) + * if (bpf_map_lookup_elem(&xsks_map, &index)) * return bpf_redirect_map(&xsks_map, index, 0); * * return XDP_PASS; @@ -286,15 +280,10 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk) BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_1, -4), BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), - BPF_LD_MAP_FD(BPF_REG_1, xsk->qidconf_map_fd), + BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd), BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), - BPF_MOV32_IMM(BPF_REG_0, 0), - /* if r1 == 0 goto +8 */ - BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 8), BPF_MOV32_IMM(BPF_REG_0, 2), - /* r1 = *(u32 *)(r1 + 0) */ - BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1, 0), /* if r1 == 0 goto +5 */ BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 5), /* r2 = *(u32 *)(r10 - 4) */ @@ -366,18 +355,11 @@ static int xsk_create_bpf_maps(struct xsk_socket *xsk) if (max_queues < 0) return max_queues; - fd = bpf_create_map_name(BPF_MAP_TYPE_ARRAY, "qidconf_map", + fd = bpf_create_map_name(BPF_MAP_TYPE_XSKMAP, "xsks_map", sizeof(int), sizeof(int), max_queues, 0); if (fd < 0) return fd; - xsk->qidconf_map_fd = fd; - fd = bpf_create_map_name(BPF_MAP_TYPE_XSKMAP, "xsks_map", - sizeof(int), sizeof(int), max_queues, 0); - if (fd < 0) { - close(xsk->qidconf_map_fd); - return fd; - } xsk->xsks_map_fd = fd; return 0; @@ -385,10 +367,8 @@ static int xsk_create_bpf_maps(struct xsk_socket *xsk) static void xsk_delete_bpf_maps(struct xsk_socket *xsk) { - close(xsk->qidconf_map_fd); + bpf_map_delete_elem(xsk->xsks_map_fd, &xsk->queue_id); close(xsk->xsks_map_fd); - xsk->qidconf_map_fd = -1; - xsk->xsks_map_fd = -1; } static int xsk_lookup_bpf_maps(struct xsk_socket *xsk) @@ -417,10 +397,9 @@ static int xsk_lookup_bpf_maps(struct xsk_socket *xsk) if (err) goto out_map_ids; - for (i = 0; i < prog_info.nr_map_ids; i++) { - if (xsk->qidconf_map_fd != -1 && xsk->xsks_map_fd != -1) - break; + xsk->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; @@ -431,11 +410,6 @@ static int xsk_lookup_bpf_maps(struct xsk_socket *xsk) continue; } - if (!strcmp(map_info.name, "qidconf_map")) { - xsk->qidconf_map_fd = fd; - continue; - } - if (!strcmp(map_info.name, "xsks_map")) { xsk->xsks_map_fd = fd; continue; @@ -445,40 +419,18 @@ static int xsk_lookup_bpf_maps(struct xsk_socket *xsk) } err = 0; - if (xsk->qidconf_map_fd < 0 || xsk->xsks_map_fd < 0) { + if (xsk->xsks_map_fd == -1) err = -ENOENT; - xsk_delete_bpf_maps(xsk); - } out_map_ids: free(map_ids); return err; } -static void xsk_clear_bpf_maps(struct xsk_socket *xsk) -{ - int qid = false; - - bpf_map_update_elem(xsk->qidconf_map_fd, &xsk->queue_id, &qid, 0); - bpf_map_delete_elem(xsk->xsks_map_fd, &xsk->queue_id); -} - static int xsk_set_bpf_maps(struct xsk_socket *xsk) { - int qid = true, fd = xsk->fd, err; - - err = bpf_map_update_elem(xsk->qidconf_map_fd, &xsk->queue_id, &qid, 0); - if (err) - goto out; - - err = bpf_map_update_elem(xsk->xsks_map_fd, &xsk->queue_id, &fd, 0); - if (err) - goto out; - - return 0; -out: - xsk_clear_bpf_maps(xsk); - return err; + return bpf_map_update_elem(xsk->xsks_map_fd, &xsk->queue_id, + &xsk->fd, 0); } static int xsk_setup_xdp_prog(struct xsk_socket *xsk) @@ -497,26 +449,27 @@ static int xsk_setup_xdp_prog(struct xsk_socket *xsk) return err; err = xsk_load_xdp_prog(xsk); - if (err) - goto out_maps; + if (err) { + xsk_delete_bpf_maps(xsk); + return err; + } } else { xsk->prog_fd = bpf_prog_get_fd_by_id(prog_id); err = xsk_lookup_bpf_maps(xsk); - if (err) - goto out_load; + if (err) { + close(xsk->prog_fd); + return err; + } } err = xsk_set_bpf_maps(xsk); - if (err) - goto out_load; + if (err) { + xsk_delete_bpf_maps(xsk); + close(xsk->prog_fd); + return err; + } return 0; - -out_load: - close(xsk->prog_fd); -out_maps: - xsk_delete_bpf_maps(xsk); - return err; } int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, @@ -643,9 +596,7 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, goto out_mmap_tx; } - xsk->qidconf_map_fd = -1; - xsk->xsks_map_fd = -1; - + xsk->prog_fd = -1; if (!(xsk->config.libbpf_flags & XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD)) { err = xsk_setup_xdp_prog(xsk); if (err) @@ -708,8 +659,10 @@ void xsk_socket__delete(struct xsk_socket *xsk) if (!xsk) return; - xsk_clear_bpf_maps(xsk); - xsk_delete_bpf_maps(xsk); + if (xsk->prog_fd != -1) { + xsk_delete_bpf_maps(xsk); + close(xsk->prog_fd); + } optlen = sizeof(off); err = getsockopt(xsk->fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen);