From ad86e1f27a9a97a9e50810b10bca678407b1d6fd Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Wed, 26 Jan 2011 11:50:03 +0100 Subject: [PATCH] netfilter: xt_connlimit: pick right dstaddr in NAT scenario MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit xt_connlimit normally records the "original" tuples in a hashlist (such as "1.2.3.4 -> 5.6.7.8"), and looks in this list for iph->daddr when counting. When the user however uses DNAT in PREROUTING, looking for iph->daddr -- which is now 192.168.9.10 -- will not match. Thus in daddr mode, we need to record the reverse direction tuple ("192.168.9.10 -> 1.2.3.4") instead. In the reverse tuple, the dst addr is on the src side, which is convenient, as count_them still uses &conn->tuple.src.u3. Signed-off-by: Jan Engelhardt --- net/netfilter/xt_connlimit.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c index 7fd3fd5..e029c48 100644 --- a/net/netfilter/xt_connlimit.c +++ b/net/netfilter/xt_connlimit.c @@ -185,11 +185,15 @@ connlimit_mt(const struct sk_buff *skb, struct xt_action_param *par) int connections; ct = nf_ct_get(skb, &ctinfo); - if (ct != NULL) - tuple_ptr = &ct->tuplehash[0].tuple; - else if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), - par->family, &tuple)) + if (ct != NULL) { + if (info->flags & XT_CONNLIMIT_DADDR) + tuple_ptr = &ct->tuplehash[IP_CT_DIR_REPLY].tuple; + else + tuple_ptr = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; + } else if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), + par->family, &tuple)) { goto hotdrop; + } if (par->family == NFPROTO_IPV6) { const struct ipv6hdr *iph = ipv6_hdr(skb); -- 2.7.4