[PATCH bpf-next v1 2/3] selftests/bpf: Add socketpair to create_pair to support unix socket

[Jiayuan Chen <jiayuan.chen@linux.dev>]

Current wrapper function create_pair() is used to create a pair of
connected links and returns two fds, but it does not support unix sockets.

Here we introduce socketpair() into create_pair(), which supports creating
a pair of unix sockets, since the semantics of the two are the same.

Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
---
 .../selftests/bpf/prog_tests/socket_helpers.h       | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/socket_helpers.h b/tools/testing/selftests/bpf/prog_tests/socket_helpers.h
index 1bdfb79ef009..a805143dd84f 100644
--- a/tools/testing/selftests/bpf/prog_tests/socket_helpers.h
+++ b/tools/testing/selftests/bpf/prog_tests/socket_helpers.h
@@ -313,11 +313,22 @@ static inline int recv_timeout(int fd, void *buf, size_t len, int flags,
 
 static inline int create_pair(int family, int sotype, int *p0, int *p1)
 {
-	__close_fd int s, c = -1, p = -1;
+	__close_fd int s = -1, c = -1, p = -1;
 	struct sockaddr_storage addr;
 	socklen_t len = sizeof(addr);
 	int err;
 
+	if (family == AF_UNIX) {
+		int fds[2];
+
+		err = socketpair(family, sotype, 0, fds);
+		if (!err) {
+			*p0 = fds[0];
+			*p1 = fds[1];
+		}
+		return err;
+	}
+
 	s = socket_loopback(family, sotype);
 	if (s < 0)
 		return s;
-- 
2.47.1