From 70315d22d3c7383f9a508d0aab21e2eb35b2303a Mon Sep 17 00:00:00 2001
From: Neal Cardwell <ncardwell@google.com>
Date: Fri, 10 Jan 2014 15:34:45 -0500
Subject: inet_diag: fix inet_diag_dump_icsk() to use correct state for
 timewait sockets

Fix inet_diag_dump_icsk() to reflect the fact that both TCP_TIME_WAIT
and TCP_FIN_WAIT2 connections are represented by inet_timewait_sock
(not just TIME_WAIT), and for such sockets the tw_substate field holds
the real state, which can be either TCP_TIME_WAIT or TCP_FIN_WAIT2.

This brings the inet_diag state-matching code in line with the field
it uses to populate idiag_state. This is also analogous to the info
exported in /proc/net/tcp, where get_tcp4_sock() exports sk->sk_state
and get_timewait4_sock() exports tw->tw_substate.

Before fixing this, (a) neither "ss -nemoi" nor "ss -nemoi state
fin-wait-2" would return a socket in TCP_FIN_WAIT2; and (b) "ss -nemoi
state time-wait" would also return sockets in state TCP_FIN_WAIT2.

This is an old bug that predates 05dbc7b ("tcp/dccp: remove twchain").

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/inet_diag.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index a0f52dac8940..e34dccbc4d70 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -930,12 +930,15 @@ skip_listen_ht:
 		spin_lock_bh(lock);
 		sk_nulls_for_each(sk, node, &head->chain) {
 			int res;
+			int state;
 
 			if (!net_eq(sock_net(sk), net))
 				continue;
 			if (num < s_num)
 				goto next_normal;
-			if (!(r->idiag_states & (1 << sk->sk_state)))
+			state = (sk->sk_state == TCP_TIME_WAIT) ?
+				inet_twsk(sk)->tw_substate : sk->sk_state;
+			if (!(r->idiag_states & (1 << state)))
 				goto next_normal;
 			if (r->sdiag_family != AF_UNSPEC &&
 			    sk->sk_family != r->sdiag_family)
-- 
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