From 4e8e9de7c25315669e2d5565acc50ec379522c28 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Fri, 6 Jan 2006 23:05:17 -0800 Subject: [PATCH] [NETFILTER]: Use conntrack information to determine if packet was NATed Preparation for IPsec support for NAT: Use conntrack information instead of saving the saving and comparing the addresses to determine if a packet was NATed and needs to be rerouted to make it easier to extend the key. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/ipv4/netfilter/ip_nat_standalone.c | 34 ++++++++++++++------------ 1 file changed, 19 insertions(+), 15 deletions(-) diff --git a/net/ipv4/netfilter/ip_nat_standalone.c b/net/ipv4/netfilter/ip_nat_standalone.c index f04111f74e0..1bb50897a5a 100644 --- a/net/ipv4/netfilter/ip_nat_standalone.c +++ b/net/ipv4/netfilter/ip_nat_standalone.c @@ -162,18 +162,20 @@ ip_nat_in(unsigned int hooknum, const struct net_device *out, int (*okfn)(struct sk_buff *)) { - u_int32_t saddr, daddr; + struct ip_conntrack *ct; + enum ip_conntrack_info ctinfo; unsigned int ret; - saddr = (*pskb)->nh.iph->saddr; - daddr = (*pskb)->nh.iph->daddr; - ret = ip_nat_fn(hooknum, pskb, in, out, okfn); if (ret != NF_DROP && ret != NF_STOLEN - && ((*pskb)->nh.iph->saddr != saddr - || (*pskb)->nh.iph->daddr != daddr)) { - dst_release((*pskb)->dst); - (*pskb)->dst = NULL; + && (ct = ip_conntrack_get(*pskb, &ctinfo)) != NULL) { + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + + if (ct->tuplehash[dir].tuple.src.ip != + ct->tuplehash[!dir].tuple.dst.ip) { + dst_release((*pskb)->dst); + (*pskb)->dst = NULL; + } } return ret; } @@ -200,7 +202,8 @@ ip_nat_local_fn(unsigned int hooknum, const struct net_device *out, int (*okfn)(struct sk_buff *)) { - u_int32_t saddr, daddr; + struct ip_conntrack *ct; + enum ip_conntrack_info ctinfo; unsigned int ret; /* root is playing with raw sockets. */ @@ -208,14 +211,15 @@ ip_nat_local_fn(unsigned int hooknum, || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) return NF_ACCEPT; - saddr = (*pskb)->nh.iph->saddr; - daddr = (*pskb)->nh.iph->daddr; - ret = ip_nat_fn(hooknum, pskb, in, out, okfn); if (ret != NF_DROP && ret != NF_STOLEN - && ((*pskb)->nh.iph->saddr != saddr - || (*pskb)->nh.iph->daddr != daddr)) - return ip_route_me_harder(pskb) == 0 ? ret : NF_DROP; + && (ct = ip_conntrack_get(*pskb, &ctinfo)) != NULL) { + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + + if (ct->tuplehash[dir].tuple.dst.ip != + ct->tuplehash[!dir].tuple.src.ip) + return ip_route_me_harder(pskb) == 0 ? ret : NF_DROP; + } return ret; } -- 2.41.1