Strengthen xdp_veth_egress to check that each destination observes the MAC selected for its own egress ifindex, instead of only checking that the observed MAC differs from a single magic value.
Add a generic XDP last-destination test where an earlier destination does not have a devmap egress program while the final destination does. This covers the case where the final destination runs on the original skb and could otherwise rewrite packet data still shared with an earlier cloned skb. Use deterministic DEVMAP_HASH keys for the egress map so the intended last destination is stable. Initialize the result map with a sentinel value and check that store_mac_1 overwrites it before checking that the earlier destination did not observe the MAC written by the final destination. Suggested-by: Jiayuan Chen <[email protected]> Signed-off-by: Sun Jian <[email protected]> --- .../selftests/bpf/prog_tests/test_xdp_veth.c | 166 +++++++++++++++++- 1 file changed, 163 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c b/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c index 3e98a1665936..1675b32753a8 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c +++ b/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c @@ -456,7 +456,11 @@ static void xdp_veth_egress(u32 flags) .remote_flags = flags, } }; - const char magic_mac[6] = { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF}; + const unsigned char egress_macs[VETH_PAIRS_COUNT][ETH_ALEN] = { + { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0x01 }, + { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0x02 }, + { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0x03 }, + }; struct xdp_redirect_multi_kern *xdp_redirect_multi_kern; struct bpf_object *bpf_objs[VETH_EGRESS_SKEL_NB]; struct xdp_redirect_map *xdp_redirect_map; @@ -512,7 +516,13 @@ static void xdp_veth_egress(u32 flags) &net_config, prog_cfg, i)) goto destroy_xdp_redirect_map; - err = bpf_map_update_elem(mac_map, &ifindex, magic_mac, 0); + { + __be64 mac = 0; + + memcpy(&mac, egress_macs[i], ETH_ALEN); + err = bpf_map_update_elem(mac_map, &ifindex, &mac, 0); + } + if (!ASSERT_OK(err, "bpf_map_update_elem")) goto destroy_xdp_redirect_map; @@ -531,15 +541,162 @@ static void xdp_veth_egress(u32 flags) for (i = 0; i < 2; i++) { u32 key = i; + __be64 expected = 0; u64 res; err = bpf_map_lookup_elem(res_map, &key, &res); if (!ASSERT_OK(err, "get MAC res")) goto destroy_xdp_redirect_map; - ASSERT_STRNEQ((const char *)&res, magic_mac, ETH_ALEN, "compare mac"); + /* store_mac_1/2 run on the second/third remote veths. */ + memcpy(&expected, egress_macs[i + 1], ETH_ALEN); + ASSERT_EQ(res, expected, "compare mac"); + } + +destroy_xdp_redirect_map: + close_netns(nstoken); + xdp_redirect_map__destroy(xdp_redirect_map); +destroy_xdp_redirect_multi_kern: + xdp_redirect_multi_kern__destroy(xdp_redirect_multi_kern); +destroy_xdp_dummy: + xdp_dummy__destroy(xdp_dummy); + + cleanup_network(&net_config); +} + +static void xdp_veth_egress_last_dst(u32 flags) +{ + struct prog_configuration prog_cfg[VETH_PAIRS_COUNT] = { + { + .local_name = "xdp_redirect_map_all_prog", + .remote_name = "xdp_dummy_prog", + .local_flags = flags, + .remote_flags = flags, + }, + { + .local_name = "xdp_redirect_map_all_prog", + .remote_name = "store_mac_1", + .local_flags = flags, + .remote_flags = flags, + }, + { + .local_name = "xdp_redirect_map_all_prog", + .remote_name = "xdp_dummy_prog", + .local_flags = flags, + .remote_flags = flags, + } + }; + const unsigned char egress_macs[VETH_PAIRS_COUNT][ETH_ALEN] = { + { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0x01 }, + { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0x02 }, + { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0x03 }, + }; + struct xdp_redirect_multi_kern *xdp_redirect_multi_kern; + struct bpf_object *bpf_objs[VETH_EGRESS_SKEL_NB]; + struct xdp_redirect_map *xdp_redirect_map; + struct net_configuration net_config = {}; + int mac_map, egress_map, res_map; + struct nstoken *nstoken = NULL; + struct xdp_dummy *xdp_dummy; + __be64 sentinel_mac = 0; + __be64 last_mac = 0; + __be64 res; + u32 key; + int err; + int i; + + xdp_dummy = xdp_dummy__open_and_load(); + if (!ASSERT_OK_PTR(xdp_dummy, "xdp_dummy__open_and_load")) + return; + + xdp_redirect_multi_kern = xdp_redirect_multi_kern__open_and_load(); + if (!ASSERT_OK_PTR(xdp_redirect_multi_kern, "xdp_redirect_multi_kern__open_and_load")) + goto destroy_xdp_dummy; + + xdp_redirect_map = xdp_redirect_map__open_and_load(); + if (!ASSERT_OK_PTR(xdp_redirect_map, "xdp_redirect_map__open_and_load")) + goto destroy_xdp_redirect_multi_kern; + + if (!ASSERT_OK(create_network(&net_config), "create network")) + goto destroy_xdp_redirect_map; + + mac_map = bpf_map__fd(xdp_redirect_multi_kern->maps.mac_map); + if (!ASSERT_OK_FD(mac_map, "open mac_map")) + goto destroy_xdp_redirect_map; + + egress_map = bpf_map__fd(xdp_redirect_multi_kern->maps.map_egress); + if (!ASSERT_OK_FD(egress_map, "open map_egress")) + goto destroy_xdp_redirect_map; + + bpf_objs[0] = xdp_dummy->obj; + bpf_objs[1] = xdp_redirect_multi_kern->obj; + bpf_objs[2] = xdp_redirect_map->obj; + + nstoken = open_netns(net_config.ns0_name); + if (!ASSERT_OK_PTR(nstoken, "open NS0")) + goto destroy_xdp_redirect_map; + + for (i = 0; i < VETH_PAIRS_COUNT; i++) { + struct bpf_devmap_val devmap_val = {}; + int ifindex = if_nametoindex(net_config.veth_cfg[i].local_veth); + u32 key = i; + + SYS(destroy_xdp_redirect_map, + "ip -n %s neigh add %s lladdr 00:00:00:00:00:01 dev %s", + net_config.veth_cfg[i].namespace, IP_NEIGH, + net_config.veth_cfg[i].remote_veth); + + if (attach_programs_to_veth_pair(bpf_objs, VETH_EGRESS_SKEL_NB, + &net_config, prog_cfg, i)) + goto destroy_xdp_redirect_map; + + { + __be64 mac = 0; + + memcpy(&mac, egress_macs[i], ETH_ALEN); + err = bpf_map_update_elem(mac_map, &ifindex, &mac, 0); + } + + if (!ASSERT_OK(err, "bpf_map_update_elem")) + goto destroy_xdp_redirect_map; + + devmap_val.ifindex = ifindex; + devmap_val.bpf_prog.fd = -1; + + if (i == VETH_PAIRS_COUNT - 1) + devmap_val.bpf_prog.fd = + bpf_program__fd(xdp_redirect_multi_kern->progs.xdp_devmap_prog); + + err = bpf_map_update_elem(egress_map, &key, &devmap_val, 0); + if (!ASSERT_OK(err, "bpf_map_update_elem")) + goto destroy_xdp_redirect_map; } + res_map = bpf_map__fd(xdp_redirect_map->maps.rx_mac); + if (!ASSERT_OK_FD(res_map, "open rx_map")) + goto destroy_xdp_redirect_map; + + memcpy(&sentinel_mac, egress_macs[VETH_PAIRS_COUNT - 1], ETH_ALEN); + memcpy(&last_mac, egress_macs[VETH_PAIRS_COUNT - 1], ETH_ALEN); + + key = 0; + err = bpf_map_update_elem(res_map, &key, &sentinel_mac, 0); + if (!ASSERT_OK(err, "init rx mac")) + goto destroy_xdp_redirect_map; + + SYS_NOFAIL("ip netns exec %s ping %s -i 0.1 -c 4 -W1 > /dev/null ", + net_config.veth_cfg[0].namespace, IP_NEIGH); + + err = bpf_map_lookup_elem(res_map, &key, &res); + if (!ASSERT_OK(err, "get MAC res")) + goto destroy_xdp_redirect_map; + + if (!ASSERT_NEQ(res, sentinel_mac, "rx_mac overwritten by store_mac_1")) + goto destroy_xdp_redirect_map; + + if (!ASSERT_NEQ(res, last_mac, "earlier dst not rewritten by last dst")) + goto destroy_xdp_redirect_map; + destroy_xdp_redirect_map: close_netns(nstoken); xdp_redirect_map__destroy(xdp_redirect_map); @@ -596,4 +753,7 @@ void test_xdp_veth_egress(void) if (test__start_subtest("SKB_MODE/egress")) xdp_veth_egress(XDP_FLAGS_SKB_MODE); + + if (test__start_subtest("SKB_MODE/egress_last_dst")) + xdp_veth_egress_last_dst(XDP_FLAGS_SKB_MODE); } -- 2.43.0
