selftests: net: reuseport_dualstack: fix uninitalized parameter

This test reports EINVAL for getsockopt(SOL_SOCKET, SO_DOMAIN)
occasionally due to the uninitialized length parameter.
Initialize it to fix this, and also use int for "test_family" to comply
with the API standard.

Fixes: d6a61f80b871 ("soreuseport: test mixed v4/v6 sockets")
Reported-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Cc: Craig Gallek <cgallek@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/tools/testing/selftests/net/reuseport_dualstack.c b/tools/testing/selftests/net/reuseport_dualstack.c
index fe3230c55986..fb7a59ed759e 100644
--- a/tools/testing/selftests/net/reuseport_dualstack.c
+++ b/tools/testing/selftests/net/reuseport_dualstack.c
@@ -129,7 +129,7 @@ static void test(int *rcv_fds, int count, int proto)
 {
         struct epoll_event ev;
         int epfd, i, test_fd;
-        uint16_t test_family;
+        int test_family;
         socklen_t len;
 
         epfd = epoll_create(1);
@@ -146,6 +146,7 @@ static void test(int *rcv_fds, int count, int proto)
         send_from_v4(proto);
 
         test_fd = receive_once(epfd, proto);
+        len = sizeof(test_family);
         if (getsockopt(test_fd, SOL_SOCKET, SO_DOMAIN, &test_family, &len))
                 error(1, errno, "failed to read socket domain");
         if (test_family != AF_INET)