Commit e9193d60 authored Oct 02, 2015 by Andrey Vagin Committed by David S. Miller Oct 05, 2015

net/unix: fix logic about sk_peek_offset



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: Andrey Vagin <avagin@openvz.org>
Tested-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 215c90af

net/unix/af_unix.c

+7 −5

Original line number	Diff line number	Diff line
		@@ -2064,6 +2064,11 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state)
		goto out;
		}

		if (flags & MSG_PEEK)
		skip = sk_peek_offset(sk, flags);
		else
		skip = 0;

		do {
		int chunk;
		struct sk_buff skb, last;
		@@ -2112,7 +2117,6 @@ unlock:
		break;
		}

		skip = sk_peek_offset(sk, flags);
		while (skip >= unix_skb_len(skb)) {
		skip -= unix_skb_len(skb);
		last = skb;
		@@ -2179,14 +2183,12 @@ unlock:
		if (UNIXCB(skb).fp)
		scm.fp = scm_fp_dup(UNIXCB(skb).fp);

		if (skip) {
		sk_peek_offset_fwd(sk, chunk);
		skip -= chunk;
		}

		if (UNIXCB(skb).fp)
		break;

		skip = 0;
		last = skb;
		last_len = skb->len;
		unix_state_lock(sk);

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