diff options
| -rw-r--r-- | net/ipv4/netfilter/ip_nat_core.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/net/ipv4/netfilter/ip_nat_core.c b/net/ipv4/netfilter/ip_nat_core.c index c1a61462507..1741d555ad0 100644 --- a/net/ipv4/netfilter/ip_nat_core.c +++ b/net/ipv4/netfilter/ip_nat_core.c @@ -434,6 +434,7 @@ int ip_nat_icmp_reply_translation(struct sk_buff **pskb, } *inside; struct ip_conntrack_tuple inner, target; int hdrlen = (*pskb)->nh.iph->ihl * 4; + unsigned long statusbit; if (!skb_make_writable(pskb, hdrlen + sizeof(*inside))) return 0; @@ -495,17 +496,16 @@ int ip_nat_icmp_reply_translation(struct sk_buff **pskb, /* Change outer to look the reply to an incoming packet * (proto 0 means don't invert per-proto part). */ + if (manip == IP_NAT_MANIP_SRC) + statusbit = IPS_SRC_NAT; + else + statusbit = IPS_DST_NAT; - /* Obviously, we need to NAT destination IP, but source IP - should be NAT'ed only if it is from a NAT'd host. + /* Invert if this is reply dir. */ + if (dir == IP_CT_DIR_REPLY) + statusbit ^= IPS_NAT_MASK; - Explanation: some people use NAT for anonymizing. Also, - CERT recommends dropping all packets from private IP - addresses (although ICMP errors from internal links with - such addresses are not too uncommon, as Alan Cox points - out) */ - if (manip != IP_NAT_MANIP_SRC - || ((*pskb)->nh.iph->saddr == ct->tuplehash[dir].tuple.src.ip)) { + if (ct->status & statusbit) { invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); if (!manip_pkt(0, pskb, 0, &target, manip)) return 0; |