skb->dev always exists in the tc flow. There is no need to use bpf_skc_lookup(), bpf_sk_lookup() from this code path.

This change facilitates fixing the tc flow to be VRF aware.

Acked-by: Stanislav Fomichev sdf@google.com Reviewed-by: Shmulik Ladkani shmulik.ladkani@gmail.com Reviewed-by: Eyal Birger eyal.birger@gmail.com Signed-off-by: Gilad Sever gilad9366@gmail.com --- net/core/filter.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/net/core/filter.c b/net/core/filter.c index 57d853460e12..e06547922edc 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -6730,8 +6730,12 @@ static const struct bpf_func_proto bpf_sk_lookup_udp_proto = { BPF_CALL_5(bpf_tc_skc_lookup_tcp, struct sk_buff *, skb, struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags) { - return (unsigned long)bpf_skc_lookup(skb, tuple, len, IPPROTO_TCP, - netns_id, flags); + struct net *caller_net = dev_net(skb->dev); + int ifindex = skb->dev->ifindex; + + return (unsigned long)__bpf_skc_lookup(skb, tuple, len, caller_net, + ifindex, IPPROTO_TCP, netns_id, + flags); }

static const struct bpf_func_proto bpf_tc_skc_lookup_tcp_proto = { @@ -6749,8 +6753,12 @@ static const struct bpf_func_proto bpf_tc_skc_lookup_tcp_proto = { BPF_CALL_5(bpf_tc_sk_lookup_tcp, struct sk_buff *, skb, struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags) { - return (unsigned long)bpf_sk_lookup(skb, tuple, len, IPPROTO_TCP, - netns_id, flags); + struct net *caller_net = dev_net(skb->dev); + int ifindex = skb->dev->ifindex; + + return (unsigned long)__bpf_sk_lookup(skb, tuple, len, caller_net, + ifindex, IPPROTO_TCP, netns_id, + flags); }

static const struct bpf_func_proto bpf_tc_sk_lookup_tcp_proto = { @@ -6768,8 +6776,12 @@ static const struct bpf_func_proto bpf_tc_sk_lookup_tcp_proto = { BPF_CALL_5(bpf_tc_sk_lookup_udp, struct sk_buff *, skb, struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags) { - return (unsigned long)bpf_sk_lookup(skb, tuple, len, IPPROTO_UDP, - netns_id, flags); + struct net *caller_net = dev_net(skb->dev); + int ifindex = skb->dev->ifindex; + + return (unsigned long)__bpf_sk_lookup(skb, tuple, len, caller_net, + ifindex, IPPROTO_UDP, netns_id, + flags); }

static const struct bpf_func_proto bpf_tc_sk_lookup_udp_proto = {

Verify that socket lookup via TC/XDP with all BPF APIs is VRF aware.

Reviewed-by: Eyal Birger eyal.birger@gmail.com Signed-off-by: Gilad Sever gilad9366@gmail.com --- v4: - Remove SYS and SYS_NOFAIL duplicate definitions

v3: - Added xdp tests as suggested by Daniel Borkmann - Use start_server() to avoid duplicate code as suggested by Stanislav Fomichev

v2: Fix build by initializing vars with -1 --- .../bpf/prog_tests/vrf_socket_lookup.c | 312 ++++++++++++++++++ .../selftests/bpf/progs/vrf_socket_lookup.c | 88 +++++ 2 files changed, 400 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/vrf_socket_lookup.c create mode 100644 tools/testing/selftests/bpf/progs/vrf_socket_lookup.c

diff --git a/tools/testing/selftests/bpf/prog_tests/vrf_socket_lookup.c b/tools/testing/selftests/bpf/prog_tests/vrf_socket_lookup.c new file mode 100644 index 000000000000..2f2562fab239 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/vrf_socket_lookup.c @@ -0,0 +1,312 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause + +/* + * Topology: + * --------- + * NS0 namespace | NS1 namespace + * | + * +--------------+ | +--------------+ + * | veth01 |----------| veth10 | + * | 172.16.1.100 | | | 172.16.1.200 | + * | bpf | | +--------------+ + * +--------------+ | + * server(UDP/TCP) | + * +-------------------+ | + * | vrf1 | | + * | +--------------+ | | +--------------+ + * | | veth02 |----------| veth20 | + * | | 172.16.2.100 | | | | 172.16.2.200 | + * | | bpf | | | +--------------+ + * | +--------------+ | | + * | server(UDP/TCP) | | + * +-------------------+ | + * + * Test flow + * ----------- + * The tests verifies that socket lookup via TC is VRF aware: + * 1) Creates two veth pairs between NS0 and NS1: + * a) veth01 <-> veth10 outside the VRF + * b) veth02 <-> veth20 in the VRF + * 2) Attaches to veth01 and veth02 a program that calls: + * a) bpf_skc_lookup_tcp() with TCP and tcp_skc is true + * b) bpf_sk_lookup_tcp() with TCP and tcp_skc is false + * c) bpf_sk_lookup_udp() with UDP + * The program stores the lookup result in bss->lookup_status. + * 3) Creates a socket TCP/UDP server in/outside the VRF. + * 4) The test expects lookup_status to be: + * a) 0 from device in VRF to server outside VRF + * b) 0 from device outside VRF to server in VRF + * c) 1 from device in VRF to server in VRF + * d) 1 from device outside VRF to server outside VRF + */ + +#include <net/if.h> + +#include "test_progs.h" +#include "network_helpers.h" +#include "vrf_socket_lookup.skel.h" + +#define NS0 "vrf_socket_lookup_0" +#define NS1 "vrf_socket_lookup_1" + +#define IP4_ADDR_VETH01 "172.16.1.100" +#define IP4_ADDR_VETH10 "172.16.1.200" +#define IP4_ADDR_VETH02 "172.16.2.100" +#define IP4_ADDR_VETH20 "172.16.2.200" + +#define NON_VRF_PORT 5000 +#define IN_VRF_PORT 5001 + +#define TIMEOUT_MS 3000 + +static int make_socket(int sotype, const char *ip, int port, + struct sockaddr_storage *addr) +{ + int err, fd; + + err = make_sockaddr(AF_INET, ip, port, addr, NULL); + if (!ASSERT_OK(err, "make_address")) + return -1; + + fd = socket(AF_INET, sotype, 0); + if (!ASSERT_GE(fd, 0, "socket")) + return -1; + + if (!ASSERT_OK(settimeo(fd, TIMEOUT_MS), "settimeo")) + goto fail; + + return fd; +fail: + close(fd); + return -1; +} + +static int make_server(int sotype, const char *ip, int port, const char *ifname) +{ + int err, fd = -1; + + fd = start_server(AF_INET, sotype, ip, port, TIMEOUT_MS); + if (!ASSERT_GE(fd, 0, "start_server")) + return -1; + + if (ifname) { + err = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, + ifname, strlen(ifname) + 1); + if (!ASSERT_OK(err, "setsockopt(SO_BINDTODEVICE)")) + goto fail; + } + + return fd; +fail: + close(fd); + return -1; +} + +static int attach_progs(char *ifname, int tc_prog_fd, int xdp_prog_fd) +{ + LIBBPF_OPTS(bpf_tc_opts, opts, .handle = 1, .priority = 1, + .prog_fd = tc_prog_fd); + LIBBPF_OPTS(bpf_tc_hook, hook, .attach_point = BPF_TC_INGRESS); + int ret, ifindex; + + ifindex = if_nametoindex(ifname); + if (!ASSERT_NEQ(ifindex, 0, "if_nametoindex")) + return -1; + hook.ifindex = ifindex; + + ret = bpf_tc_hook_create(&hook); + if (!ASSERT_OK(ret, "bpf_tc_hook_create")) + return ret; + + ret = bpf_tc_attach(&hook, &opts); + if (!ASSERT_OK(ret, "bpf_tc_attach")) { + bpf_tc_hook_destroy(&hook); + return ret; + } + ret = bpf_xdp_attach(ifindex, xdp_prog_fd, 0, NULL); + if (!ASSERT_OK(ret, "bpf_xdp_attach")) { + bpf_tc_hook_destroy(&hook); + return ret; + } + + return 0; +} + +static void cleanup(void) +{ + SYS_NOFAIL("test -f /var/run/netns/" NS0 " && ip netns delete " + NS0); + SYS_NOFAIL("test -f /var/run/netns/" NS1 " && ip netns delete " + NS1); +} + +static int setup(struct vrf_socket_lookup *skel) +{ + int tc_prog_fd, xdp_prog_fd, ret = 0; + struct nstoken *nstoken = NULL; + + SYS(fail, "ip netns add " NS0); + SYS(fail, "ip netns add " NS1); + + /* NS0 <-> NS1 [veth01 <-> veth10] */ + SYS(fail, "ip link add veth01 netns " NS0 " type veth peer name veth10" + " netns " NS1); + SYS(fail, "ip -net " NS0 " addr add " IP4_ADDR_VETH01 "/24 dev veth01"); + SYS(fail, "ip -net " NS0 " link set dev veth01 up"); + SYS(fail, "ip -net " NS1 " addr add " IP4_ADDR_VETH10 "/24 dev veth10"); + SYS(fail, "ip -net " NS1 " link set dev veth10 up"); + + /* NS0 <-> NS1 [veth02 <-> veth20] */ + SYS(fail, "ip link add veth02 netns " NS0 " type veth peer name veth20" + " netns " NS1); + SYS(fail, "ip -net " NS0 " addr add " IP4_ADDR_VETH02 "/24 dev veth02"); + SYS(fail, "ip -net " NS0 " link set dev veth02 up"); + SYS(fail, "ip -net " NS1 " addr add " IP4_ADDR_VETH20 "/24 dev veth20"); + SYS(fail, "ip -net " NS1 " link set dev veth20 up"); + + /* veth02 -> vrf1 */ + SYS(fail, "ip -net " NS0 " link add vrf1 type vrf table 11"); + SYS(fail, "ip -net " NS0 " route add vrf vrf1 unreachable default" + " metric 4278198272"); + SYS(fail, "ip -net " NS0 " link set vrf1 alias vrf"); + SYS(fail, "ip -net " NS0 " link set vrf1 up"); + SYS(fail, "ip -net " NS0 " link set veth02 master vrf1"); + + /* Attach TC and XDP progs to veth devices in NS0 */ + nstoken = open_netns(NS0); + if (!ASSERT_OK_PTR(nstoken, "setns " NS0)) + goto fail; + tc_prog_fd = bpf_program__fd(skel->progs.tc_socket_lookup); + if (!ASSERT_GE(tc_prog_fd, 0, "bpf_program__tc_fd")) + goto fail; + xdp_prog_fd = bpf_program__fd(skel->progs.xdp_socket_lookup); + if (!ASSERT_GE(xdp_prog_fd, 0, "bpf_program__xdp_fd")) + goto fail; + + if (attach_progs("veth01", tc_prog_fd, xdp_prog_fd)) + goto fail; + + if (attach_progs("veth02", tc_prog_fd, xdp_prog_fd)) + goto fail; + + goto close; +fail: + ret = -1; +close: + if (nstoken) + close_netns(nstoken); + return ret; +} + +static int test_lookup(struct vrf_socket_lookup *skel, int sotype, + const char *ip, int port, bool test_xdp, bool tcp_skc, + int lookup_status_exp) +{ + static const char msg[] = "Hello Server"; + struct sockaddr_storage addr = {}; + int fd, ret = 0; + + fd = make_socket(sotype, ip, port, &addr); + if (fd < 0) + return -1; + + skel->bss->test_xdp = test_xdp; + skel->bss->tcp_skc = tcp_skc; + skel->bss->lookup_status = -1; + + if (sotype == SOCK_STREAM) + connect(fd, (void *)&addr, sizeof(struct sockaddr_in)); + else + sendto(fd, msg, sizeof(msg), 0, (void *)&addr, + sizeof(struct sockaddr_in)); + + if (!ASSERT_EQ(skel->bss->lookup_status, lookup_status_exp, + "lookup_status")) + goto fail; + + goto close; + +fail: + ret = -1; +close: + close(fd); + return ret; +} + +static void _test_vrf_socket_lookup(struct vrf_socket_lookup *skel, int sotype, + bool test_xdp, bool tcp_skc) +{ + int in_vrf_server = -1, non_vrf_server = -1; + struct nstoken *nstoken = NULL; + + nstoken = open_netns(NS0); + if (!ASSERT_OK_PTR(nstoken, "setns " NS0)) + goto done; + + /* Open sockets in and outside VRF */ + non_vrf_server = make_server(sotype, "0.0.0.0", NON_VRF_PORT, NULL); + if (!ASSERT_GE(non_vrf_server, 0, "make_server__outside_vrf_fd")) + goto done; + + in_vrf_server = make_server(sotype, "0.0.0.0", IN_VRF_PORT, "veth02"); + if (!ASSERT_GE(in_vrf_server, 0, "make_server__in_vrf_fd")) + goto done; + + /* Perform test from NS1 */ + close_netns(nstoken); + nstoken = open_netns(NS1); + if (!ASSERT_OK_PTR(nstoken, "setns " NS1)) + goto done; + + if (!ASSERT_OK(test_lookup(skel, sotype, IP4_ADDR_VETH02, NON_VRF_PORT, + test_xdp, tcp_skc, 0), "in_to_out")) + goto done; + if (!ASSERT_OK(test_lookup(skel, sotype, IP4_ADDR_VETH02, IN_VRF_PORT, + test_xdp, tcp_skc, 1), "in_to_in")) + goto done; + if (!ASSERT_OK(test_lookup(skel, sotype, IP4_ADDR_VETH01, NON_VRF_PORT, + test_xdp, tcp_skc, 1), "out_to_out")) + goto done; + if (!ASSERT_OK(test_lookup(skel, sotype, IP4_ADDR_VETH01, IN_VRF_PORT, + test_xdp, tcp_skc, 0), "out_to_in")) + goto done; + +done: + if (non_vrf_server >= 0) + close(non_vrf_server); + if (in_vrf_server >= 0) + close(in_vrf_server); + if (nstoken) + close_netns(nstoken); +} + +void test_vrf_socket_lookup(void) +{ + struct vrf_socket_lookup *skel; + + cleanup(); + + skel = vrf_socket_lookup__open_and_load(); + if (!ASSERT_OK_PTR(skel, "vrf_socket_lookup__open_and_load")) + return; + + if (!ASSERT_OK(setup(skel), "setup")) + goto done; + + if (test__start_subtest("tc_socket_lookup_tcp")) + _test_vrf_socket_lookup(skel, SOCK_STREAM, false, false); + if (test__start_subtest("tc_socket_lookup_tcp_skc")) + _test_vrf_socket_lookup(skel, SOCK_STREAM, false, false); + if (test__start_subtest("tc_socket_lookup_udp")) + _test_vrf_socket_lookup(skel, SOCK_STREAM, false, false); + if (test__start_subtest("xdp_socket_lookup_tcp")) + _test_vrf_socket_lookup(skel, SOCK_STREAM, true, false); + if (test__start_subtest("xdp_socket_lookup_tcp_skc")) + _test_vrf_socket_lookup(skel, SOCK_STREAM, true, false); + if (test__start_subtest("xdp_socket_lookup_udp")) + _test_vrf_socket_lookup(skel, SOCK_STREAM, true, false); + +done: + vrf_socket_lookup__destroy(skel); + cleanup(); +} diff --git a/tools/testing/selftests/bpf/progs/vrf_socket_lookup.c b/tools/testing/selftests/bpf/progs/vrf_socket_lookup.c new file mode 100644 index 000000000000..26e07a252585 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/vrf_socket_lookup.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/bpf.h> +#include <linux/ip.h> +#include <linux/in.h> +#include <linux/if_ether.h> +#include <linux/pkt_cls.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_endian.h> +#include <stdbool.h> + +int lookup_status; +bool test_xdp; +bool tcp_skc; + +#define CUR_NS BPF_F_CURRENT_NETNS + +static void socket_lookup(void *ctx, void *data_end, void *data) +{ + struct ethhdr *eth = data; + struct bpf_sock_tuple *tp; + struct bpf_sock *sk; + struct iphdr *iph; + int tplen; + + if (eth + 1 > data_end) + return; + + if (eth->h_proto != bpf_htons(ETH_P_IP)) + return; + + iph = (struct iphdr *)(eth + 1); + if (iph + 1 > data_end) + return; + + tp = (struct bpf_sock_tuple *)&iph->saddr; + tplen = sizeof(tp->ipv4); + if ((void *)tp + tplen > data_end) + return; + + switch (iph->protocol) { + case IPPROTO_TCP: + if (tcp_skc) + sk = bpf_skc_lookup_tcp(ctx, tp, tplen, CUR_NS, 0); + else + sk = bpf_sk_lookup_tcp(ctx, tp, tplen, CUR_NS, 0); + break; + case IPPROTO_UDP: + sk = bpf_sk_lookup_udp(ctx, tp, tplen, CUR_NS, 0); + break; + default: + return; + } + + lookup_status = 0; + + if (sk) { + bpf_sk_release(sk); + lookup_status = 1; + } +} + +SEC("tc") +int tc_socket_lookup(struct __sk_buff *skb) +{ + void *data_end = (void *)(long)skb->data_end; + void *data = (void *)(long)skb->data; + + if (test_xdp) + return TC_ACT_UNSPEC; + + socket_lookup(skb, data_end, data); + return TC_ACT_UNSPEC; +} + +SEC("xdp") +int xdp_socket_lookup(struct xdp_md *xdp) +{ + void *data_end = (void *)(long)xdp->data_end; + void *data = (void *)(long)xdp->data; + + if (!test_xdp) + return XDP_PASS; + + socket_lookup(xdp, data_end, data); + return XDP_PASS; +} + +char _license[] SEC("license") = "GPL";