[PATCH bpf-next 4/4] selftests/bpf: Add bpf_fib_lookup test

Martin KaFai Lau
2023-02-17T00:42:12Z

This patch tests the bpf_fib_lookup helper when looking up
a neigh in NUD_FAILED and NUD_STALE state. It also adds test
for the new BPF_FIB_LOOKUP_SKIP_NEIGH flag.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
---
.../selftests/bpf/prog_tests/fib_lookup.c | 187 ++++++++++++++++++
.../testing/selftests/bpf/progs/fib_lookup.c | 22 +++
2 files changed, 209 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/fib_lookup.c
create mode 100644 tools/testing/selftests/bpf/progs/fib_lookup.c

diff --git a/tools/testing/selftests/bpf/prog_tests/fib_lookup.c b/tools/testing/selftests/bpf/prog_tests/fib_lookup.c
new file mode 100644
index 000000000000..61ccddccf485
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/fib_lookup.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
+
+#include <sys/types.h>
+#include <net/if.h>
+
+#include "test_progs.h"
+#include "network_helpers.h"
+#include "fib_lookup.skel.h"
+
+#define SYS(fmt, ...) \
+ ({ \
+ char cmd[1024]; \
+ snprintf(cmd, sizeof(cmd), fmt, ##__VA_ARGS__); \
+ if (!ASSERT_OK(system(cmd), cmd)) \
+ goto fail; \
+ })
+
+#define NS_TEST "fib_lookup_ns"
+#define IPV6_IFACE_ADDR "face::face"
+#define IPV6_NUD_FAILED_ADDR "face::1"
+#define IPV6_NUD_STALE_ADDR "face::2"
+#define IPV4_IFACE_ADDR "10.0.0.254"
+#define IPV4_NUD_FAILED_ADDR "10.0.0.1"
+#define IPV4_NUD_STALE_ADDR "10.0.0.2"
+#define DMAC "11:11:11:11:11:11"
+#define DMAC_INIT { 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, }
+
+struct fib_lookup_test {
+ const char *desc;
+ const char *daddr;
+ int expected_ret;
+ int lookup_flags;
+ __u8 dmac[6];
+};
+
+static const struct fib_lookup_test tests[] = {
+ { .desc = "IPv6 failed neigh",
+ .daddr = IPV6_NUD_FAILED_ADDR, .expected_ret = BPF_FIB_LKUP_RET_NO_NEIGH, },
+ { .desc = "IPv6 stale neigh",
+ .daddr = IPV6_NUD_STALE_ADDR, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
+ .dmac = DMAC_INIT, },
+ { .desc = "IPv6 skip neigh",
+ .daddr = IPV6_NUD_FAILED_ADDR, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
+ .lookup_flags = BPF_FIB_LOOKUP_SKIP_NEIGH, },
+ { .desc = "IPv4 failed neigh",
+ .daddr = IPV4_NUD_FAILED_ADDR, .expected_ret = BPF_FIB_LKUP_RET_NO_NEIGH, },
+ { .desc = "IPv4 stale neigh",
+ .daddr = IPV4_NUD_STALE_ADDR, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
+ .dmac = DMAC_INIT, },
+ { .desc = "IPv4 skip neigh",
+ .daddr = IPV4_NUD_FAILED_ADDR, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
+ .lookup_flags = BPF_FIB_LOOKUP_SKIP_NEIGH, },
+};
+
+static int ifindex;
+
+static int setup_netns(void)
+{
+ int err;
+
+ SYS("ip link add veth1 type veth peer name veth2");
+ SYS("ip link set dev veth1 up");
+
+ SYS("ip addr add %s/64 dev veth1 nodad", IPV6_IFACE_ADDR);
+ SYS("ip neigh add %s dev veth1 nud failed", IPV6_NUD_FAILED_ADDR);
+ SYS("ip neigh add %s dev veth1 lladdr %s nud stale", IPV6_NUD_STALE_ADDR, DMAC);
+
+ SYS("ip addr add %s/24 dev veth1 nodad", IPV4_IFACE_ADDR);
+ SYS("ip neigh add %s dev veth1 nud failed", IPV4_NUD_FAILED_ADDR);
+ SYS("ip neigh add %s dev veth1 lladdr %s nud stale", IPV4_NUD_STALE_ADDR, DMAC);
+
+ err = write_sysctl("/proc/sys/net/ipv4/conf/veth1/forwarding", "1");
+ if (!ASSERT_OK(err, "write_sysctl(net.ipv4.conf.veth1.forwarding)"))
+ goto fail;
+
+ err = write_sysctl("/proc/sys/net/ipv6/conf/veth1/forwarding", "1");
+ if (!ASSERT_OK(err, "write_sysctl(net.ipv6.conf.veth1.forwarding)"))
+ goto fail;
+
+ return 0;
+fail:
+ return -1;
+}
+
+static int set_lookup_params(struct bpf_fib_lookup *params, const char *daddr)
+{
+ int ret;
+
+ memset(params, 0, sizeof(*params));
+
+ params->l4_protocol = IPPROTO_TCP;
+ params->ifindex = ifindex;
+
+ if (inet_pton(AF_INET6, daddr, params->ipv6_dst) == 1) {
+ params->family = AF_INET6;
+ ret = inet_pton(AF_INET6, IPV6_IFACE_ADDR, params->ipv6_src);
+ if (!ASSERT_EQ(ret, 1, "inet_pton(IPV6_IFACE_ADDR)"))
+ return -1;
+ return 0;
+ }
+
+ ret = inet_pton(AF_INET, daddr, &params->ipv4_dst);
+ if (!ASSERT_EQ(ret, 1, "convert IP[46] address"))
+ return -1;
+ params->family = AF_INET;
+ ret = inet_pton(AF_INET, IPV4_IFACE_ADDR, &params->ipv4_src);
+ if (!ASSERT_EQ(ret, 1, "inet_pton(IPV4_IFACE_ADDR)"))
+ return -1;
+
+ return 0;
+}
+
+static void mac_str(char *b, const __u8 *mac)
+{
+ sprintf(b, "%02X:%02X:%02X:%02X:%02X:%02X",
+ mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+}
+
+void test_fib_lookup(void)
+{
+ struct bpf_fib_lookup *fib_params;
+ struct nstoken *nstoken = NULL;
+ struct __sk_buff skb = { };
+ struct fib_lookup *skel;
+ int prog_fd, err, ret, i;
+
+ /* The test does not use the skb->data, so
+ * use pkt_v6 for both v6 and v4 test.
+ */
+ LIBBPF_OPTS(bpf_test_run_opts, run_opts,
+ .data_in = &pkt_v6,
+ .data_size_in = sizeof(pkt_v6),
+ .ctx_in = &skb,
+ .ctx_size_in = sizeof(skb),
+ );
+
+ skel = fib_lookup__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "skel open_and_load"))
+ return;
+ prog_fd = bpf_program__fd(skel->progs.fib_lookup);
+
+ SYS("ip netns add %s", NS_TEST);
+
+ nstoken = open_netns(NS_TEST);
+ if (!ASSERT_OK_PTR(nstoken, "open_netns"))
+ goto fail;
+
+ if (setup_netns())
+ goto fail;
+
+ ifindex = if_nametoindex("veth1");
+ skb.ifindex = ifindex;
+ fib_params = &skel->bss->fib_params;
+
+ for (i = 0; i < ARRAY_SIZE(tests); i++) {
+ printf("Testing %s\n", tests[i].desc);
+
+ if (set_lookup_params(fib_params, tests[i].daddr))
+ continue;
+ skel->bss->fib_lookup_ret = -1;
+ skel->bss->lookup_flags = BPF_FIB_LOOKUP_OUTPUT |
+ tests[i].lookup_flags;
+
+ err = bpf_prog_test_run_opts(prog_fd, &run_opts);
+ if (!ASSERT_OK(err, "bpf_prog_test_run_opts"))
+ continue;
+
+ ASSERT_EQ(tests[i].expected_ret, skel->bss->fib_lookup_ret,
+ "fib_lookup_ret");
+
+ ret = memcmp(tests[i].dmac, fib_params->dmac, sizeof(tests[i].dmac));
+ if (!ASSERT_EQ(ret, 0, "dmac not match")) {
+ char expected[18], actual[18];
+
+ mac_str(expected, tests[i].dmac);
+ mac_str(actual, fib_params->dmac);
+ printf("dmac expected %s actual %s\n", expected, actual);
+ }
+ }
+
+fail:
+ if (nstoken)
+ close_netns(nstoken);
+ system("ip netns del " NS_TEST " &> /dev/null");
+ fib_lookup__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/fib_lookup.c b/tools/testing/selftests/bpf/progs/fib_lookup.c
new file mode 100644
index 000000000000..c4514dd58c62
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/fib_lookup.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
+
+#include <linux/types.h>
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_tracing_net.h"
+
+struct bpf_fib_lookup fib_params = {};
+int fib_lookup_ret = 0;
+int lookup_flags = 0;
+
+SEC("tc")
+int fib_lookup(struct __sk_buff *skb)
+{
+ fib_lookup_ret = bpf_fib_lookup(skb, &fib_params, sizeof(fib_params),
+ lookup_flags);
+
+ return TC_ACT_SHOT;
+}
+
+char _license[] SEC("license") = "GPL";
--
2.30.2