[PATCH v5 bpf-next 6/7] selftests/bpf: Add helper to get port using getsockname

[Aditi Ghag <aditi.ghag@xxxxxxxxxxxxx>]

The helper will be used to programmatically retrieve,
and pass ports in userspace and kernel selftest programs.

Suggested-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
Signed-off-by: Aditi Ghag <aditi.ghag@xxxxxxxxxxxxx>
---
 tools/testing/selftests/bpf/network_helpers.c | 14 ++++++++++++++
 tools/testing/selftests/bpf/network_helpers.h |  1 +
 2 files changed, 15 insertions(+)

diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index 596caa176582..4c1dc7cf7390 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -427,3 +427,17 @@ void close_netns(struct nstoken *token)
 	close(token->orig_netns_fd);
 	free(token);
 }
+
+int get_sock_port6(int sock_fd, __u16 *out_port)
+{
+	struct sockaddr_in6 addr = {};
+	socklen_t addr_len = sizeof(addr);
+	int err;
+
+	err = getsockname(sock_fd, (struct sockaddr *)&addr, &addr_len);
+	if (err < 0)
+		return err;
+	*out_port = addr.sin6_port;
+
+	return err;
+}
diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
index f882c691b790..2ab3b50de0b7 100644
--- a/tools/testing/selftests/bpf/network_helpers.h
+++ b/tools/testing/selftests/bpf/network_helpers.h
@@ -56,6 +56,7 @@ int fastopen_connect(int server_fd, const char *data, unsigned int data_len,
 int make_sockaddr(int family, const char *addr_str, __u16 port,
 		  struct sockaddr_storage *addr, socklen_t *len);
 char *ping_command(int family);
+int get_sock_port6(int sock_fd, __u16 *out_port);
 
 struct nstoken;
 /**
-- 
2.34.1