Commit f465fb24 authored by Andrey Vagin's avatar Andrey Vagin Committed by Luis Henriques

net/unix: fix logic about sk_peek_offset

commit e9193d60 upstream.

Now send with MSG_PEEK can return data from multiple SKBs.

Unfortunately we take into account the peek offset for each skb,
that is wrong. We need to apply the peek offset only once.

In addition, the peek offset should be used only if MSG_PEEK is set.

Cc: "David S. Miller" <davem@davemloft.net> (maintainer:NETWORKING
Cc: Eric Dumazet <edumazet@google.com> (commit_signer:1/14=7%)
Cc: Aaron Conole <aconole@bytheb.org>
Fixes: 9f389e35 ("af_unix: return data from multiple SKBs on recv() with MSG_PEEK flag")
Signed-off-by: default avatarAndrey Vagin <avagin@openvz.org>
Tested-by: default avatarAaron Conole <aconole@bytheb.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent f50e5d9f
...@@ -1962,6 +1962,11 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, ...@@ -1962,6 +1962,11 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
goto out; goto out;
} }
if (flags & MSG_PEEK)
skip = sk_peek_offset(sk, flags);
else
skip = 0;
do { do {
int chunk; int chunk;
struct sk_buff *skb, *last; struct sk_buff *skb, *last;
...@@ -2008,7 +2013,6 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, ...@@ -2008,7 +2013,6 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
break; break;
} }
skip = sk_peek_offset(sk, flags);
while (skip >= unix_skb_len(skb)) { while (skip >= unix_skb_len(skb)) {
skip -= unix_skb_len(skb); skip -= unix_skb_len(skb);
last = skb; last = skb;
...@@ -2070,14 +2074,12 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, ...@@ -2070,14 +2074,12 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
if (UNIXCB(skb).fp) if (UNIXCB(skb).fp)
siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
if (skip) { sk_peek_offset_fwd(sk, chunk);
sk_peek_offset_fwd(sk, chunk);
skip -= chunk;
}
if (UNIXCB(skb).fp) if (UNIXCB(skb).fp)
break; break;
skip = 0;
last = skb; last = skb;
unix_state_lock(sk); unix_state_lock(sk);
skb = skb_peek_next(skb, &sk->sk_receive_queue); skb = skb_peek_next(skb, &sk->sk_receive_queue);
......
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