diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c index bfd88e4e06851396929b1ad7b9c63333a458dc76..fac97cf51ae52c5ec4e934da520bbb538697ac9b 100644 --- a/net/ipv4/netfilter/nf_nat_sip.c +++ b/net/ipv4/netfilter/nf_nat_sip.c @@ -222,6 +222,29 @@ static unsigned int mangle_sdp(struct sk_buff **pskb, return mangle_content_len(pskb, ctinfo, ct, dptr); } +static void ip_nat_sdp_expect(struct nf_conn *ct, + struct nf_conntrack_expect *exp) +{ + struct nf_nat_range range; + + /* This must be a fresh one. */ + BUG_ON(ct->status & IPS_NAT_DONE_MASK); + + /* Change src to where master sends to */ + range.flags = IP_NAT_RANGE_MAP_IPS; + range.min_ip = range.max_ip + = ct->master->tuplehash[!exp->dir].tuple.dst.u3.ip; + /* hook doesn't matter, but it has to do source manip */ + nf_nat_setup_info(ct, &range, NF_IP_POST_ROUTING); + + /* For DST manip, map port here to where it's expected. */ + range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED); + range.min = range.max = exp->saved_proto; + range.min_ip = range.max_ip = exp->saved_ip; + /* hook doesn't matter, but it has to do destination manip */ + nf_nat_setup_info(ct, &range, NF_IP_PRE_ROUTING); +} + /* So, this packet has hit the connection tracking matching code. Mangle it, and change the expectation to match the new version. */ static unsigned int ip_nat_sdp(struct sk_buff **pskb, @@ -239,13 +262,14 @@ static unsigned int ip_nat_sdp(struct sk_buff **pskb, /* Connection will come from reply */ newip = ct->tuplehash[!dir].tuple.dst.u3.ip; + exp->saved_ip = exp->tuple.dst.u3.ip; exp->tuple.dst.u3.ip = newip; exp->saved_proto.udp.port = exp->tuple.dst.u.udp.port; exp->dir = !dir; /* When you see the packet, we need to NAT it the same as the this one. */ - exp->expectfn = nf_nat_follow_master; + exp->expectfn = ip_nat_sdp_expect; /* Try to get same port: if not, try to change it. */ for (port = ntohs(exp->saved_proto.udp.port); port != 0; port++) {