Test IPv6 sockets also work with SIOCGSKNS.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 .../testing/selftests/namespaces/siocgskns_test.c  | 34 ++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/tools/testing/selftests/namespaces/siocgskns_test.c b/tools/testing/selftests/namespaces/siocgskns_test.c
index 17f2cafb75a7..1c40c7772ad4 100644
--- a/tools/testing/selftests/namespaces/siocgskns_test.c
+++ b/tools/testing/selftests/namespaces/siocgskns_test.c
@@ -543,4 +543,38 @@ TEST(siocgskns_netns_lifecycle)
 	close(sock_fd);
 }
 
+/*
+ * Test IPv6 sockets also work with SIOCGSKNS.
+ */
+TEST(siocgskns_ipv6)
+{
+	int sock_fd, netns_fd, current_netns_fd;
+	struct stat st1, st2;
+
+	/* Create an IPv6 TCP socket */
+	sock_fd = socket(AF_INET6, SOCK_STREAM, 0);
+	ASSERT_GE(sock_fd, 0);
+
+	/* Use SIOCGSKNS */
+	netns_fd = ioctl(sock_fd, SIOCGSKNS);
+	if (netns_fd < 0) {
+		close(sock_fd);
+		if (errno == ENOTTY || errno == EINVAL)
+			SKIP(return, "SIOCGSKNS not supported");
+		ASSERT_GE(netns_fd, 0);
+	}
+
+	/* Verify it matches current namespace */
+	current_netns_fd = open("/proc/self/ns/net", O_RDONLY);
+	ASSERT_GE(current_netns_fd, 0);
+
+	ASSERT_EQ(fstat(netns_fd, &st1), 0);
+	ASSERT_EQ(fstat(current_netns_fd, &st2), 0);
+	ASSERT_EQ(st1.st_ino, st2.st_ino);
+
+	close(sock_fd);
+	close(netns_fd);
+	close(current_netns_fd);
+}
+
 TEST_HARNESS_MAIN

-- 
2.47.3