selftests/bpf: Use connect_to_addr in sk_assign

This patch uses public helper connect_to_addr() exported in
network_helpers.h instead of the local defined function connect_to_server()
in prog_tests/sk_assign.c. This can avoid duplicate code.

The code that sets SO_SNDTIMEO timeout as timeo_sec (3s) can be dropped,
since connect_to_addr() sets default timeout as 3s.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Link: https://lore.kernel.org/r/98fdd384872bda10b2adb052e900a2212c9047b9.1713427236.git.tanggeliang@kylinos.cnSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

tools/testing/selftests/bpf/prog_tests/sk_assign.c

@@ -23,8 +23,6 @@
 #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);
 static int stop, duration;
 
 static bool
@@ -74,28 +72,6 @@ configure_stack(void)
 	return true;
 }
 
-static int
-connect_to_server(const struct sockaddr *addr, socklen_t len, int type)
-{
-	int fd = -1;
-
-	fd = socket(addr->sa_family, type, 0);
-	if (CHECK_FAIL(fd == -1))
-		goto out;
-	if (CHECK_FAIL(setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeo_sec,
-				  timeo_optlen)))
-		goto close_out;
-	if (CHECK_FAIL(connect(fd, addr, len)))
-		goto close_out;
-
-	goto out;
-close_out:
-	close(fd);
-	fd = -1;
-out:
-	return fd;
-}
-
 static in_port_t
 get_port(int fd)
 {
@@ -138,7 +114,7 @@ run_test(int server_fd, const struct sockaddr *addr, socklen_t len, int type)
 	in_port_t port;
 	int ret = 1;
 
-	client = connect_to_server(addr, len, type);
+	client = connect_to_addr(type, (struct sockaddr_storage *)addr, len, NULL);
 	if (client == -1) {
 		perror("Cannot connect to server");
 		goto out;