Commit 29df44fa authored by Cong Wang's avatar Cong Wang Committed by Alexei Starovoitov
Browse files

af_unix: Implement ->read_sock() for sockmap 



Implement ->read_sock() for AF_UNIX datagram socket, it is
pretty much similar to udp_read_sock().

Signed-off-by: default avatarCong Wang <cong.wang@bytedance.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210704190252.11866-4-xiyou.wangcong@gmail.com
parent 0c48eefa

net/unix/af_unix.c

+37 −0
Original line number Diff line number Diff line
@@ -669,6 +669,8 @@ static ssize_t unix_stream_splice_read(struct socket *, loff_t *ppos, 
				       unsigned int flags);

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_read_sock(struct sock *sk, read_descriptor_t *desc,

			  sk_read_actor_t recv_actor);

static int unix_dgram_connect(struct socket *, struct sockaddr *,

			      int, int);

static int unix_seqpacket_sendmsg(struct socket *, struct msghdr *, size_t);
@@ -746,6 +748,7 @@ static const struct proto_ops unix_dgram_ops = { 
	.listen =	sock_no_listen,

	.shutdown =	unix_shutdown,

	.sendmsg =	unix_dgram_sendmsg,

	.read_sock =	unix_read_sock,

	.recvmsg =	unix_dgram_recvmsg,

	.mmap =		sock_no_mmap,

	.sendpage =	sock_no_sendpage,
@@ -2188,6 +2191,40 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, 
	return err;

}



static int unix_read_sock(struct sock *sk, read_descriptor_t *desc,

			  sk_read_actor_t recv_actor)

{

	int copied = 0;



	while (1) {

		struct unix_sock *u = unix_sk(sk);

		struct sk_buff *skb;

		int used, err;



		mutex_lock(&u->iolock);

		skb = skb_recv_datagram(sk, 0, 1, &err);

		mutex_unlock(&u->iolock);

		if (!skb)

			return err;



		used = recv_actor(desc, skb, 0, skb->len);

		if (used <= 0) {

			if (!copied)

				copied = used;

			kfree_skb(skb);

			break;

		} else if (used <= skb->len) {

			copied += used;

		}



		kfree_skb(skb);

		if (!desc->count)

			break;

	}



	return copied;

}



/*

 *	Sleep until more data has arrived. But check for races..

 */