[PATCH bpf-next v5 05/11] af_unix: add a dummy ->close() for sockmap

[Cong Wang <xiyou.wangcong@gmail.com>]

From: Cong Wang <cong.wang@bytedance.com>

Unlike af_inet, unix_proto is very different, it does not even
have a ->close(). We have to add a dummy implementation to
satisfy sockmap. Normally it is just a nop, it is introduced only
for sockmap to replace it.

Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
---
 net/unix/af_unix.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 77fb3910e1c3..875eeaaddc07 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -781,10 +781,18 @@ static const struct proto_ops unix_seqpacket_ops = {
 	.show_fdinfo =	unix_show_fdinfo,
 };
 
+static void unix_close(struct sock *sk, long timeout)
+{
+	/* Nothing to do here, unix socket does not need a ->close().
+	 * This is merely for sockmap.
+	 */
+}
+
 static struct proto unix_proto = {
 	.name			= "UNIX",
 	.owner			= THIS_MODULE,
 	.obj_size		= sizeof(struct unix_sock),
+	.close			= unix_close,
 };
 
 static struct sock *unix_create1(struct net *net, struct socket *sock, int kern)
@@ -868,6 +876,7 @@ static int unix_release(struct socket *sock)
 	if (!sk)
 		return 0;
 
+	sk->sk_prot->close(sk, 0);
 	unix_release_sock(sk, 0);
 	sock->sk = NULL;
 
-- 
2.27.0