Commit 3504bb63 authored Sep 29, 2015 by David S. Miller

Merge branch 'af_unix_MSG_PEEK'



Aaron Conole says:

====================
af_unix: return data from multiple SKBs on recv() with MSG_PEEK flag

This patch set implements a bugfix for kernel.org bugzilla #12323, allowing
MSG_PEEK to return all queued data on the unix domain socket, not just the
data contained in a single SKB.

This is the v3 version of this patch, which includes a suggested modification
by Eric Dumazet to convert the unix_sk() conversion macro to a static inline
function. These patches are independent and can be applied separately.

This set was tested over a 24-hour period, utilizing a loop continually
executing the bugzilla issue attached python code. It was instrumented with
a pr_err_once() ([   13.798683] unix: went there at least one time).

v2->v3:
 - Added Eric Dumazet's suggestion for #define to static inline
 - Fixed an issue calling unix_state_lock() with an invalid argument

v3->v4:
 - Eliminated an XXX comment
 - Changed from goto unlock to explicit unix_state_unlock() and break
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

parents 2103d6b8 9f389e35

include/net/af_unix.h

+5 −1

Original line number	Diff line number	Diff line
		@@ -63,7 +63,11 @@ struct unix_sock {
		#define UNIX_GC_MAYBE_CYCLE 1
		struct socket_wq peer_wq;
		};
		#define unix_sk(__sk) ((struct unix_sock *)__sk)

		static inline struct unix_sock unix_sk(struct sock sk)
		{
		return (struct unix_sock *)sk;
		}

		#define peer_wait peer_wq.wait

net/unix/af_unix.c

+14 −1

Original line number	Diff line number	Diff line
		@@ -2179,8 +2179,21 @@ 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;

		last = skb;
		last_len = skb->len;
		unix_state_lock(sk);
		skb = skb_peek_next(skb, &sk->sk_receive_queue);
		if (skb)
		goto again;
		unix_state_unlock(sk);
		break;
		}
		} while (size);

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