From mboxrd@z Thu Jan 1 00:00:00 1970 From: pablo@netfilter.org Subject: [PATCH 2/3] netfilter: nf_ct_helper: don't discard helper if it is actually the same Date: Wed, 13 Feb 2013 21:38:32 +0100 Message-ID: <1360787913-10335-3-git-send-email-pablo@netfilter.org> References: <1360787913-10335-1-git-send-email-pablo@netfilter.org> Cc: davem@davemloft.net, netdev@vger.kernel.org To: netfilter-devel@vger.kernel.org Return-path: Received: from slan-550-85.anhosting.com ([209.236.71.68]:56399 "EHLO slan-550-85.anhosting.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934256Ab3BMUiq (ORCPT ); Wed, 13 Feb 2013 15:38:46 -0500 In-Reply-To: <1360787913-10335-1-git-send-email-pablo@netfilter.org> Sender: netfilter-devel-owner@vger.kernel.org List-ID: From: Florian Westphal 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 --- net/netfilter/nf_conntrack_helper.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) 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; } -- 1.7.10.4