[bpf-next,v4,02/12] af_unix: implement ->read_sock() for sockmap

Message ID 20210508220835.53801-3-xiyou.wangcong@gmail.com
State New
Headers show
Series
  • sockmap: add sockmap support for unix datagram socket
Related show

Commit Message

Cong Wang May 8, 2021, 10:08 p.m.
From: Cong Wang <cong.wang@bytedance.com>

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

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 | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

Comments

Cong Wang May 18, 2021, 4:51 a.m. | #1
On Sat, May 8, 2021 at 3:09 PM Cong Wang <xiyou.wangcong@gmail.com> wrote:
> +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;

> +                       break;

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

> +                       copied += used;

> +               }

> +


Like udp_read_sock(), we should also free the skb here.
I will update this and send V5 soon.

Thanks.

Patch

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 5a31307ceb76..26d18f948737 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -661,6 +661,8 @@  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);
@@ -738,6 +740,7 @@  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,
@@ -2183,6 +2186,38 @@  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;
+			break;
+		} else if (used <= skb->len) {
+			copied += used;
+		}
+
+		if (!desc->count)
+			break;
+	}
+
+	return copied;
+}
+
 /*
  *	Sleep until more data has arrived. But check for races..
  */