[PATCH] ctnetlink: fix list traversal order

[Harald Welte <laforge@netfilter.org>]

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Hi Dave, please apply.

[NETFILTER] fix list traversal order in ctnetlink

Currently conntracks are inserted after the head. That means that
conntracks are sorted from the biggest to the smallest id. This happens
because we use list_prepend (list_add) instead list_add_tail. This can
result in problems during the list iteration.

                 list_for_each(i, &ip_conntrack_hash[cb->args[0]]) {
                         h = (struct ip_conntrack_tuple_hash *) i;
                         if (DIRECTION(h) != IP_CT_DIR_ORIGINAL)
                                 continue;
                         ct = tuplehash_to_ctrack(h);
                         if (ct->id <= *id)
                                 continue;

In that case just the first conntrack in the bucket will be dumped. To
fix this, we iterate the list from the tail to the head via
list_for_each_prev. Same thing for the list of expectations.

Signed-off-by: Pablo Neira Ayuso <pablo@eurodev.net>
Signed-off-by: Harald Welte <laforge@netfilter.org>

---
commit 570b2053cc2c68da90b71add2a4f4366673b48d8
tree bbcf496f0fb3fc468db26a03ccf1455e206a2251
parent 76596b57e2fe552da8beef4a59d5b559dfc3d0e5
author Harald Welte <laforge@netfilter.org> Fr, 05 Aug 2005 14:25:50 +0200
committer Harald Welte <laforge@netfilter.org> Fr, 05 Aug 2005 14:25:50 +0200

 net/ipv4/netfilter/ip_conntrack_netlink.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/netfilter/ip_conntrack_netlink.c b/net/ipv4/netfilter/ip_conntrack_netlink.c
--- a/net/ipv4/netfilter/ip_conntrack_netlink.c
+++ b/net/ipv4/netfilter/ip_conntrack_netlink.c
@@ -404,7 +404,7 @@ ctnetlink_dump_table(struct sk_buff *skb
 
 	read_lock_bh(&ip_conntrack_lock);
 	for (; cb->args[0] < ip_conntrack_htable_size; cb->args[0]++, *id = 0) {
-		list_for_each(i, &ip_conntrack_hash[cb->args[0]]) {
+		list_for_each_prev(i, &ip_conntrack_hash[cb->args[0]]) {
 			h = (struct ip_conntrack_tuple_hash *) i;
 			if (DIRECTION(h) != IP_CT_DIR_ORIGINAL)
 				continue;
@@ -441,7 +441,7 @@ ctnetlink_dump_table_w(struct sk_buff *s
 
 	write_lock_bh(&ip_conntrack_lock);
 	for (; cb->args[0] < ip_conntrack_htable_size; cb->args[0]++, *id = 0) {
-		list_for_each(i, &ip_conntrack_hash[cb->args[0]]) {
+		list_for_each_prev(i, &ip_conntrack_hash[cb->args[0]]) {
 			h = (struct ip_conntrack_tuple_hash *) i;
 			if (DIRECTION(h) != IP_CT_DIR_ORIGINAL)
 				continue;
@@ -1214,7 +1214,7 @@ ctnetlink_exp_dump_table(struct sk_buff 
 	DEBUGP("entered %s, last id=%llu\n", __FUNCTION__, *id);
 
 	read_lock_bh(&ip_conntrack_lock);
-	list_for_each(i, &ip_conntrack_expect_list) {
+	list_for_each_prev(i, &ip_conntrack_expect_list) {
 		exp = (struct ip_conntrack_expect *) i;
 		if (exp->id <= *id)
 			continue;
-- 
- Harald Welte <laforge@netfilter.org>                 http://netfilter.org/
============================================================================
  "Fragmentation is like classful addressing -- an interesting early
   architectural error that shows how much experimentation was going
   on while IP was being designed."                    -- Paul Vixie

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