diff options
| -rw-r--r-- | samples/bpf/xdp_fwd_kern.c | 17 | ||||
| -rw-r--r-- | samples/bpf/xdp_fwd_user.c | 33 |
2 files changed, 33 insertions, 17 deletions
diff --git a/samples/bpf/xdp_fwd_kern.c b/samples/bpf/xdp_fwd_kern.c index e6ffc4ea06f4..a43d6953c054 100644 --- a/samples/bpf/xdp_fwd_kern.c +++ b/samples/bpf/xdp_fwd_kern.c @@ -104,13 +104,18 @@ static __always_inline int xdp_fwd_flags(struct xdp_md *ctx, u32 flags) rc = bpf_fib_lookup(ctx, &fib_params, sizeof(fib_params), flags); - /* verify egress index has xdp support - * TO-DO bpf_map_lookup_elem(&tx_port, &key) fails with - * cannot pass map_type 14 into func bpf_map_lookup_elem#1: - * NOTE: without verification that egress index supports XDP - * forwarding packets are dropped. - */ if (rc == 0) { + /* Verify egress index has been configured as TX-port. + * (Note: User can still have inserted an egress ifindex that + * doesn't support XDP xmit, which will result in packet drops). + * + * Note: lookup in devmap supported since 0cdbb4b09a0. + * If not supported will fail with: + * cannot pass map_type 14 into func bpf_map_lookup_elem#1: + */ + if (!bpf_map_lookup_elem(&xdp_tx_ports, &fib_params.ifindex)) + return XDP_PASS; + if (h_proto == htons(ETH_P_IP)) ip_decrease_ttl(iph); else if (h_proto == htons(ETH_P_IPV6)) diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c index ba012d9f93dd..97ff1dad7669 100644 --- a/samples/bpf/xdp_fwd_user.c +++ b/samples/bpf/xdp_fwd_user.c @@ -27,14 +27,20 @@ #include "libbpf.h" #include <bpf/bpf.h> - -static int do_attach(int idx, int fd, const char *name) +static int do_attach(int idx, int prog_fd, int map_fd, const char *name) { int err; - err = bpf_set_link_xdp_fd(idx, fd, 0); - if (err < 0) + err = bpf_set_link_xdp_fd(idx, prog_fd, 0); + if (err < 0) { printf("ERROR: failed to attach program to %s\n", name); + return err; + } + + /* Adding ifindex as a possible egress TX port */ + err = bpf_map_update_elem(map_fd, &idx, &idx, 0); + if (err) + printf("ERROR: failed using device %s as TX-port\n", name); return err; } @@ -47,6 +53,9 @@ static int do_detach(int idx, const char *name) if (err < 0) printf("ERROR: failed to detach program from %s\n", name); + /* TODO: Remember to cleanup map, when adding use of shared map + * bpf_map_delete_elem((map_fd, &idx); + */ return err; } @@ -67,10 +76,10 @@ int main(int argc, char **argv) }; const char *prog_name = "xdp_fwd"; struct bpf_program *prog; + int prog_fd, map_fd = -1; char filename[PATH_MAX]; struct bpf_object *obj; int opt, i, idx, err; - int prog_fd, map_fd; int attach = 1; int ret = 0; @@ -103,8 +112,14 @@ int main(int argc, char **argv) return 1; } - if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd)) + err = bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd); + if (err) { + printf("Does kernel support devmap lookup?\n"); + /* If not, the error message will be: + * "cannot pass map_type 14 into func bpf_map_lookup_elem#1" + */ return 1; + } prog = bpf_object__find_program_by_title(obj, prog_name); prog_fd = bpf_program__fd(prog); @@ -119,10 +134,6 @@ int main(int argc, char **argv) return 1; } } - if (attach) { - for (i = 1; i < 64; ++i) - bpf_map_update_elem(map_fd, &i, &i, 0); - } for (i = optind; i < argc; ++i) { idx = if_nametoindex(argv[i]); @@ -138,7 +149,7 @@ int main(int argc, char **argv) if (err) ret = err; } else { - err = do_attach(idx, prog_fd, argv[i]); + err = do_attach(idx, prog_fd, map_fd, argv[i]); if (err) ret = err; } |