selftests/bpf: Use SOCKMAP for server sockets in bpf_sk_assign test

Update bpf_sk_assign test to fetch the server socket from SOCKMAP, now that
map lookup from BPF in SOCKMAP is enabled. This way the test TC BPF program
doesn't need to know what address server socket is bound to.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200429181154.479310-4-jakub@cloudflare.com

1 files changed, 20 insertions, 1 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/sk_assign.c b/tools/testing/selftests/bpf/prog_tests/sk_assign.c
index d572e1a2c297..47fa04adc147 100644
--- a/tools/testing/selftests/bpf/prog_tests/sk_assign.c
+++ b/tools/testing/selftests/bpf/prog_tests/sk_assign.c
@@ -20,6 +20,7 @@
 #define CONNECT_PORT 4321
 #define TEST_DADDR (0xC0A80203)
 #define NS_SELF "/proc/self/ns/net"
+#define SERVER_MAP_PATH "/sys/fs/bpf/tc/globals/server_map"
 
 static const struct timeval timeo_sec = { .tv_sec = 3 };
 static const size_t timeo_optlen = sizeof(timeo_sec);
@@ -265,6 +266,7 @@ void test_sk_assign(void)
 		TEST("ipv6 udp addr redir", AF_INET6, SOCK_DGRAM, true),
 	};
 	int server = -1;
+	int server_map;
 	int self_net;
 
 	self_net = open(NS_SELF, O_RDONLY);
@@ -278,9 +280,17 @@ void test_sk_assign(void)
 		goto cleanup;
 	}
 
+	server_map = bpf_obj_get(SERVER_MAP_PATH);
+	if (CHECK_FAIL(server_map < 0)) {
+		perror("Unable to open " SERVER_MAP_PATH);
+		goto cleanup;
+	}
+
 	for (int i = 0; i < ARRAY_SIZE(tests) && !READ_ONCE(stop); i++) {
 		struct test_sk_cfg *test = &tests[i];
 		const struct sockaddr *addr;
+		const int zero = 0;
+		int err;
 
 		if (!test__start_subtest(test->name))
 			continue;
@@ -288,7 +298,13 @@ void test_sk_assign(void)
 		addr = (const struct sockaddr *)test->addr;
 		server = start_server(addr, test->len, test->type);
 		if (server == -1)
-			goto cleanup;
+			goto close;
+
+		err = bpf_map_update_elem(server_map, &zero, &server, BPF_ANY);
+		if (CHECK_FAIL(err)) {
+			perror("Unable to update server_map");
+			goto close;
+		}
 
 		/* connect to unbound ports */
 		prepare_addr(test->addr, test->family, CONNECT_PORT,
@@ -302,7 +318,10 @@ void test_sk_assign(void)
 
 close:
 	close(server);
+	close(server_map);
 cleanup:
+	if (CHECK_FAIL(unlink(SERVER_MAP_PATH)))
+		perror("Unable to unlink " SERVER_MAP_PATH);
 	if (CHECK_FAIL(setns(self_net, CLONE_NEWNET)))
 		perror("Failed to setns("NS_SELF")");
 	close(self_net);