af_unix: Add a dummy ->close() for sockmap

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.

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210704190252.11866-6-xiyou.wangcong@gmail.com

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 77fb391..875eeaa 100644 (file)
--- 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;