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charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Wed, May 5, 2021 at 10:14 AM Jakub Sitnicki wrote: > > On Mon, Apr 26, 2021 at 04:49 AM CEST, Cong Wang wrote: > > From: Cong Wang > > > > Implement ->read_sock() for AF_UNIX datagram socket, it is > > pretty much similar to udp_read_sock(). > > > > Cc: John Fastabend > > Cc: Daniel Borkmann > > Cc: Jakub Sitnicki > > Cc: Lorenz Bauer > > Signed-off-by: Cong Wang > > --- > > net/unix/af_unix.c | 38 ++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 38 insertions(+) > > > > diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c > > index 5a31307ceb76..f4dc22db371d 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 +2186,41 @@ 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); > > + if (!skb) { > > + mutex_unlock(&u->iolock); > > + return err; > > + } > > + > > + used = recv_actor(desc, skb, 0, skb->len); > > + if (used <= 0) { > > + if (!copied) > > + copied = used; > > + mutex_unlock(&u->iolock); > > + break; > > + } else if (used <= skb->len) { > > + copied += used; > > + } > > + mutex_unlock(&u->iolock); > > Do we need hold the mutex for recv_actor to process the skb? Hm, it does look like we can just release it after dequeuing the skb. Let me double check. Thanks.