diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 89b36de5fdbb..c91b5a4bda03 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5079,17 +5079,19 @@ union bpf_attr { * Description * Redirect the packet to another net device of index *ifindex*. * This helper is somewhat similar to **bpf_redirect**\ (), except - * that the redirection happens to the *ifindex*' peer device and - * the netns switch takes place from ingress to ingress without - * going through the CPU's backlog queue. + * that the redirection happens to the *ifindex*' peer device. If + * *flags* is 0, the netns switch takes place from ingress to + * ingress without going through the CPU's backlog queue. If the + * **BPF_F_EGRESS** flag is provided then redirection happens in + * the egress direction of the peer device. * * *skb*\ **->mark** and *skb*\ **->tstamp** are not cleared during * the netns switch. * - * The *flags* argument is reserved and must be 0. The helper is - * currently only supported for tc BPF program types at the - * ingress hook and for veth and netkit target device types. The - * peer device must reside in a different network namespace. + * If the *flags* argument is 0, the helper is currently only + * supported for tc BPF program types at the ingress hook and for + * veth and netkit target device types. The peer device must reside + * in a different network namespace. * Return * The helper returns **TC_ACT_REDIRECT** on success or * **TC_ACT_SHOT** on error. @@ -6336,9 +6338,10 @@ enum { /* Flags for bpf_redirect and bpf_redirect_map helpers */ enum { BPF_F_INGRESS = (1ULL << 0), /* used for skb path */ + BPF_F_EGRESS = (1ULL << 1), /* used for skb path */ BPF_F_BROADCAST = (1ULL << 3), /* used for XDP path */ BPF_F_EXCLUDE_INGRESS = (1ULL << 4), /* used for XDP path */ -#define BPF_F_REDIRECT_FLAGS (BPF_F_INGRESS | BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS) +#define BPF_F_REDIRECT_FLAGS (BPF_F_INGRESS | BPF_F_EGRESS | BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS) }; #define __bpf_md_ptr(type, name) \ diff --git a/net/core/filter.c b/net/core/filter.c index b446aa8be5c3..4f5cbcac3e78 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2529,16 +2529,18 @@ int skb_do_redirect(struct sk_buff *skb) if (unlikely(!dev)) goto out_drop; if (flags & BPF_F_PEER) { - if (unlikely(!skb_at_tc_ingress(skb))) - goto out_drop; dev = skb_get_peer_dev(dev); if (unlikely(!dev || !(dev->flags & IFF_UP) || net_eq(net, dev_net(dev)))) goto out_drop; + skb_scrub_packet(skb, false); + if (flags & BPF_F_EGRESS) + return __bpf_redirect(skb, dev, 0); + if (unlikely(!skb_at_tc_ingress(skb))) + goto out_drop; skb->dev = dev; dev_sw_netstats_rx_add(dev, skb->len); - skb_scrub_packet(skb, false); return -EAGAIN; } return flags & BPF_F_NEIGH ? @@ -2575,10 +2577,10 @@ BPF_CALL_2(bpf_redirect_peer, u32, ifindex, u64, flags) { struct bpf_redirect_info *ri = bpf_net_ctx_get_ri(); - if (unlikely(flags)) + if (unlikely(flags & ~BPF_F_EGRESS)) return TC_ACT_SHOT; - ri->flags = BPF_F_PEER; + ri->flags = BPF_F_PEER | flags; ri->tgt_index = ifindex; return TC_ACT_REDIRECT; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 89b36de5fdbb..c91b5a4bda03 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5079,17 +5079,19 @@ union bpf_attr { * Description * Redirect the packet to another net device of index *ifindex*. * This helper is somewhat similar to **bpf_redirect**\ (), except - * that the redirection happens to the *ifindex*' peer device and - * the netns switch takes place from ingress to ingress without - * going through the CPU's backlog queue. + * that the redirection happens to the *ifindex*' peer device. If + * *flags* is 0, the netns switch takes place from ingress to + * ingress without going through the CPU's backlog queue. If the + * **BPF_F_EGRESS** flag is provided then redirection happens in + * the egress direction of the peer device. * * *skb*\ **->mark** and *skb*\ **->tstamp** are not cleared during * the netns switch. * - * The *flags* argument is reserved and must be 0. The helper is - * currently only supported for tc BPF program types at the - * ingress hook and for veth and netkit target device types. The - * peer device must reside in a different network namespace. + * If the *flags* argument is 0, the helper is currently only + * supported for tc BPF program types at the ingress hook and for + * veth and netkit target device types. The peer device must reside + * in a different network namespace. * Return * The helper returns **TC_ACT_REDIRECT** on success or * **TC_ACT_SHOT** on error. @@ -6336,9 +6338,10 @@ enum { /* Flags for bpf_redirect and bpf_redirect_map helpers */ enum { BPF_F_INGRESS = (1ULL << 0), /* used for skb path */ + BPF_F_EGRESS = (1ULL << 1), /* used for skb path */ BPF_F_BROADCAST = (1ULL << 3), /* used for XDP path */ BPF_F_EXCLUDE_INGRESS = (1ULL << 4), /* used for XDP path */ -#define BPF_F_REDIRECT_FLAGS (BPF_F_INGRESS | BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS) +#define BPF_F_REDIRECT_FLAGS (BPF_F_INGRESS | BPF_F_EGRESS | BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS) }; #define __bpf_md_ptr(type, name) \ diff --git a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c index 64fbda082309..af8968b89ad7 100644 --- a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c +++ b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c @@ -192,6 +192,8 @@ static int create_netkit(int mode, char *prim, char *peer) req.n.nlmsg_len += sizeof(struct ifinfomsg); addattr_l(&req.n, sizeof(req), IFLA_IFNAME, peer, strlen(peer)); addattr_nest_end(&req.n, peer_info); + addattr32(&req.n, sizeof(req), IFLA_NETKIT_SCRUB, + NETKIT_SCRUB_NONE); addattr_nest_end(&req.n, data); addattr_nest_end(&req.n, linkinfo); @@ -405,6 +407,24 @@ static int netns_load_bpf(const struct bpf_program *src_prog, return -1; } +static struct bpf_link *netns_attach_nk(const char *ns, int ifindex, + struct bpf_program *prog) +{ + LIBBPF_OPTS(bpf_netkit_opts, optl); + struct nstoken *nstoken = NULL; + struct bpf_link *link = NULL; + + nstoken = open_netns(ns); + if (!ASSERT_OK_PTR(nstoken, "setns")) + goto cleanup; + + link = bpf_program__attach_netkit(prog, ifindex, &optl); +cleanup: + if (nstoken) + close_netns(nstoken); + return link; +} + static void test_tcp(int family, const char *addr, __u16 port) { int listen_fd = -1, accept_fd = -1, client_fd = -1; @@ -1082,6 +1102,53 @@ static void test_tc_redirect_peer(struct netns_setup_result *setup_result) close_netns(nstoken); } +static void test_tc_redirect_peer_ing(struct netns_setup_result *setup_result) +{ + struct test_tc_peer *skel; + struct nstoken *nstoken; + int err; + + nstoken = open_netns(NS_FWD); + if (!ASSERT_OK_PTR(nstoken, "setns fwd")) + return; + + skel = test_tc_peer__open(); + if (!ASSERT_OK_PTR(skel, "test_tc_peer__open")) + goto done; + + skel->rodata->IFINDEX_SRC = setup_result->ifindex_src_fwd; + skel->rodata->IFINDEX_DST = setup_result->ifindex_dst_fwd; + ASSERT_EQ(bpf_program__set_expected_attach_type(skel->progs.tc_src_ing, + BPF_NETKIT_PRIMARY), 0, "src_prog_attach_type"); + ASSERT_EQ(bpf_program__set_expected_attach_type(skel->progs.tc_dst_ing, + BPF_NETKIT_PRIMARY), 0, "dst_prog_attach_type"); + + err = test_tc_peer__load(skel); + if (!ASSERT_OK(err, "test_tc_peer__load")) + goto done; + + skel->links.tc_src_ing = netns_attach_nk(NS_SRC, + setup_result->ifindex_src, + skel->progs.tc_src_ing); + if (!ASSERT_OK_PTR(skel->links.tc_src_ing, "attach_src")) + goto done; + skel->links.tc_dst_ing = netns_attach_nk(NS_DST, + setup_result->ifindex_dst, + skel->progs.tc_dst_ing); + if (!ASSERT_OK_PTR(skel->links.tc_dst_ing, "attach_dst")) + goto done; + + if (!ASSERT_OK(set_forwarding(false), "disable forwarding")) + goto done; + + test_connectivity(); + +done: + if (skel) + test_tc_peer__destroy(skel); + close_netns(nstoken); +} + static int tun_open(char *name) { struct ifreq ifr; @@ -1280,6 +1347,7 @@ static void *test_tc_redirect_run_tests(void *arg) RUN_TEST(tc_redirect_peer, MODE_VETH); RUN_TEST(tc_redirect_peer, MODE_NETKIT); + RUN_TEST(tc_redirect_peer_ing, MODE_NETKIT); RUN_TEST(tc_redirect_peer_l3, MODE_VETH); RUN_TEST(tc_redirect_peer_l3, MODE_NETKIT); RUN_TEST(tc_redirect_neigh, MODE_VETH); diff --git a/tools/testing/selftests/bpf/progs/test_tc_peer.c b/tools/testing/selftests/bpf/progs/test_tc_peer.c index 365eacb5dc34..cfb9ef7f467c 100644 --- a/tools/testing/selftests/bpf/progs/test_tc_peer.c +++ b/tools/testing/selftests/bpf/progs/test_tc_peer.c @@ -34,6 +34,28 @@ int tc_src(struct __sk_buff *skb) return bpf_redirect_peer(IFINDEX_DST, 0); } +SEC("tc") +int tc_dst_ing(struct __sk_buff *skb) +{ + if (!skb->mark) { + skb->mark = 0x1; + return bpf_redirect_peer(IFINDEX_SRC, BPF_F_EGRESS); + } + + return bpf_redirect(IFINDEX_DST, 0); +} + +SEC("tc") +int tc_src_ing(struct __sk_buff *skb) +{ + if (!skb->mark) { + skb->mark = 0x1; + return bpf_redirect_peer(IFINDEX_DST, BPF_F_EGRESS); + } + + return bpf_redirect(IFINDEX_SRC, 0); +} + SEC("tc") int tc_dst_l3(struct __sk_buff *skb) {