From 6e2f0aa8cf8892868bf2c19349cb5d7c407f690d Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 12 Feb 2013 05:59:53 +0000 Subject: netfilter: nf_ct_helper: don't discard helper if it is actually the same commit (32f5376 netfilter: nf_ct_helper: disable automatic helper re-assignment of different type) broke transparent proxy scenarios. For example, initial helper lookup might yield "ftp" (dport 21), while re-lookup after REDIRECT yields "ftp-2121". This causes the autoassign code to toss the ftp helper, even though these are just different instances of the same helper. Change the test to check for the helper function address instead of the helper address, as suggested by Pablo. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index 884f2b3..91527d5 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -236,7 +236,9 @@ int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl, /* We only allow helper re-assignment of the same sort since * we cannot reallocate the helper extension area. */ - if (help->helper != helper) { + struct nf_conntrack_helper *tmp = rcu_dereference(help->helper); + + if (tmp && tmp->help != helper->help) { RCU_INIT_POINTER(help->helper, NULL); goto out; } -- cgit v0.10.2