[3.5.y.z extended stable] Patch "inet_diag: fix inet_diag_dump_icsk() timewait socket state logic" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    inet_diag: fix inet_diag_dump_icsk() timewait socket state logic

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 0eb03a8dbd81c6e29a7be226b1ee32f6760b89fd Mon Sep 17 00:00:00 2001
From: Neal Cardwell <ncardwell at google.com>
Date: Sun, 2 Feb 2014 20:40:13 -0500
Subject: inet_diag: fix inet_diag_dump_icsk() timewait socket state logic

[ Based upon upstream commit 70315d22d3c7383f9a508d0aab21e2eb35b2303a ]

Fix inet_diag_dump_icsk() to reflect the fact that both TIME_WAIT and
FIN_WAIT2 connections are represented by inet_timewait_sock (not just
TIME_WAIT). Thus:

(a) We need to iterate through the time_wait buckets if the user wants
either TIME_WAIT or FIN_WAIT2. (Before fixing this, "ss -nemoi state
fin-wait-2" would not return any sockets, even if there were some in
FIN_WAIT2.)

(b) We need to check tw_substate to see if the user wants to dump
sockets in the particular substate (TIME_WAIT or FIN_WAIT2) that a
given connection is in. (Before fixing this, "ss -nemoi state
time-wait" would actually return sockets in state FIN_WAIT2.)

An analogous fix is in v3.13: 70315d22d3c7383f9a508d0aab21e2eb35b2303a
("inet_diag: fix inet_diag_dump_icsk() to use correct state for
timewait sockets") but that patch is quite different because 3.13 code
is very different in this area due to the unification of TCP hash
tables in 05dbc7b ("tcp/dccp: remove twchain") in v3.13-rc1.

I tested that this applies cleanly between v3.3 and v3.12, and tested
that it works in both 3.3 and 3.12. It does not apply cleanly to 3.2
and earlier (though it makes semantic sense), and semantically is not
the right fix for 3.13 and beyond (as mentioned above).

Signed-off-by: Neal Cardwell <ncardwell at google.com>
Cc: Eric Dumazet <edumazet at google.com>
Acked-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/ipv4/inet_diag.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index e530c31..60e48d7 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -941,7 +941,7 @@ next_normal:
 			++num;
 		}

-		if (r->idiag_states & TCPF_TIME_WAIT) {
+		if (r->idiag_states & (TCPF_TIME_WAIT | TCPF_FIN_WAIT2)) {
 			struct inet_timewait_sock *tw;

 			inet_twsk_for_each(tw, node,
@@ -949,6 +949,8 @@ next_normal:

 				if (num < s_num)
 					goto next_dying;
+				if (!(r->idiag_states & (1 << tw->tw_substate)))
+					goto next_dying;
 				if (r->sdiag_family != AF_UNSPEC &&
 						tw->tw_family != r->sdiag_family)
 					goto next_dying;
--
1.8.3.2