[Patch bpf-next 10/19] af_unix: implement ->sendmsg_locked for dgram socket

[Cong Wang]

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

We already have unix_dgram_sendmsg(), we can just build
its ->sendmsg_locked() on top of it.

Cc: John Fastabend <john.fastab...@gmail.com>
Cc: Daniel Borkmann <dan...@iogearbox.net>
Cc: Jakub Sitnicki <ja...@cloudflare.com>
Cc: Lorenz Bauer <l...@cloudflare.com>
Signed-off-by: Cong Wang <cong.w...@bytedance.com>
---
 net/unix/af_unix.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 41c3303c3357..4e1fa4ecbcfb 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -659,6 +659,7 @@ static ssize_t unix_stream_sendpage(struct socket *, struct 
page *, int offset,
 static ssize_t unix_stream_splice_read(struct socket *,  loff_t *ppos,
                                       struct pipe_inode_info *, size_t size,
                                       unsigned int flags);
+static int __unix_dgram_sendmsg(struct sock*, struct msghdr *, size_t);
 static int unix_dgram_sendmsg(struct socket *, struct msghdr *, size_t);
 static int unix_dgram_recvmsg(struct socket *, struct msghdr *, size_t, int);
 static int unix_dgram_connect(struct socket *, struct sockaddr *,
@@ -738,6 +739,7 @@ static const struct proto_ops unix_dgram_ops = {
        .listen =       sock_no_listen,
        .shutdown =     unix_shutdown,
        .sendmsg =      unix_dgram_sendmsg,
+       .sendmsg_locked = __unix_dgram_sendmsg,
        .recvmsg =      unix_dgram_recvmsg,
        .mmap =         sock_no_mmap,
        .sendpage =     sock_no_sendpage,
@@ -1611,10 +1613,10 @@ static void scm_stat_del(struct sock *sk, struct 
sk_buff *skb)
  *     Send AF_UNIX data.
  */
 
-static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
-                             size_t len)
+static int __unix_dgram_sendmsg(struct sock *sk, struct msghdr *msg,
+                               size_t len)
 {
-       struct sock *sk = sock->sk;
+       struct socket *sock = sk->sk_socket;
        struct net *net = sock_net(sk);
        struct unix_sock *u = unix_sk(sk);
        DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name);
@@ -1814,6 +1816,12 @@ static int unix_dgram_sendmsg(struct socket *sock, 
struct msghdr *msg,
        return err;
 }
 
+static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
+                             size_t len)
+{
+       return __unix_dgram_sendmsg(sock->sk, msg, len);
+}
+
 /* We use paged skbs for stream sockets, and limit occupancy to 32768
  * bytes, and a minimum of a full page.
  */
-- 
2.25.1