| Message ID | 4F43D516.9060102@parallels.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
Le mardi 21 février 2012 à 21:32 +0400, Pavel Emelyanov a écrit : > The same here -- we can protect the sk_peek_off manipulations with > the unix_sk->readlock mutex. > > The peeking of data from a stream socket is done in the datagram style, > i.e. even if there's enough room for more data in the user buffer, only > the head skb's data is copied in there. This feature is preserved when > peeking data from a given offset -- the data is read till the nearest > skb's boundary. > > Signed-off-by: Pavel Emelyanov <xemul@parallels.com> > > --- Acked-by: Eric Dumazet <eric.dumazet@gmail.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Tue, 21 Feb 2012 18:51:19 +0100 > Le mardi 21 février 2012 à 21:32 +0400, Pavel Emelyanov a écrit : >> The same here -- we can protect the sk_peek_off manipulations with >> the unix_sk->readlock mutex. >> >> The peeking of data from a stream socket is done in the datagram style, >> i.e. even if there's enough room for more data in the user buffer, only >> the head skb's data is copied in there. This feature is preserved when >> peeking data from a given offset -- the data is read till the nearest >> skb's boundary. >> >> Signed-off-by: Pavel Emelyanov <xemul@parallels.com> >> >> --- > > Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 3d9481d..0be4d24 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -559,6 +559,7 @@ static const struct proto_ops unix_stream_ops = { .recvmsg = unix_stream_recvmsg, .mmap = sock_no_mmap, .sendpage = sock_no_sendpage, + .set_peek_off = unix_set_peek_off, }; static const struct proto_ops unix_dgram_ops = { @@ -1904,6 +1905,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, int target; int err = 0; long timeo; + int skip; err = -EINVAL; if (sk->sk_state != TCP_ESTABLISHED) @@ -1933,12 +1935,15 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, goto out; } + skip = sk_peek_offset(sk, flags); + do { int chunk; struct sk_buff *skb; unix_state_lock(sk); skb = skb_peek(&sk->sk_receive_queue); +again: if (skb == NULL) { unix_sk(sk)->recursion_level = 0; if (copied >= target) @@ -1973,6 +1978,13 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, unix_state_unlock(sk); break; } + + if (skip >= skb->len) { + skip -= skb->len; + skb = skb_peek_next(skb, &sk->sk_receive_queue); + goto again; + } + unix_state_unlock(sk); if (check_creds) { @@ -1992,8 +2004,8 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, sunaddr = NULL; } - chunk = min_t(unsigned int, skb->len, size); - if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) { + chunk = min_t(unsigned int, skb->len - skip, size); + if (memcpy_toiovec(msg->msg_iov, skb->data + skip, chunk)) { if (copied == 0) copied = -EFAULT; break; @@ -2005,6 +2017,8 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, if (!(flags & MSG_PEEK)) { skb_pull(skb, chunk); + sk_peek_offset_bwd(sk, chunk); + if (UNIXCB(skb).fp) unix_detach_fds(siocb->scm, skb); @@ -2022,6 +2036,8 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, if (UNIXCB(skb).fp) siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); + sk_peek_offset_fwd(sk, chunk); + break; } } while (size);
The same here -- we can protect the sk_peek_off manipulations with the unix_sk->readlock mutex. The peeking of data from a stream socket is done in the datagram style, i.e. even if there's enough room for more data in the user buffer, only the head skb's data is copied in there. This feature is preserved when peeking data from a given offset -- the data is read till the nearest skb's boundary. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> --- net/unix/af_unix.c | 20 ++++++++++++++++++-- 1 files changed, 18 insertions(+), 2 deletions(-)