From 5978a9b82c55b82a1087bd86e0ae8b00f94d0d0b Mon Sep 17 00:00:00 2001 From: Philip Craig Date: Wed, 9 Nov 2005 13:01:53 -0800 Subject: [PATCH] [NETFILTER] PPTP helper: fix PNS-PAC expectation call id The reply tuple of the PNS->PAC expectation was using the wrong call id. So we had the following situation: - PNS behind NAT firewall - PNS call id requires NATing - PNS->PAC gre packet arrives first then the PNS->PAC expectation is matched, and the other expectation is deleted, but the PAC->PNS gre packets do not match the gre conntrack because the call id is wrong. We also cannot use ip_nat_follow_master(). Signed-off-by: Philip Craig Signed-off-by: Harald Welte Signed-off-by: David S. Miller --- net/ipv4/netfilter/ip_nat_helper_pptp.c | 28 +++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/net/ipv4/netfilter/ip_nat_helper_pptp.c b/net/ipv4/netfilter/ip_nat_helper_pptp.c index ee6ab74ad3a..e546203f566 100644 --- a/net/ipv4/netfilter/ip_nat_helper_pptp.c +++ b/net/ipv4/netfilter/ip_nat_helper_pptp.c @@ -73,6 +73,7 @@ static void pptp_nat_expected(struct ip_conntrack *ct, struct ip_conntrack_tuple t; struct ip_ct_pptp_master *ct_pptp_info; struct ip_nat_pptp *nat_pptp_info; + struct ip_nat_range range; ct_pptp_info = &master->help.ct_pptp_info; nat_pptp_info = &master->nat.help.nat_pptp_info; @@ -110,7 +111,30 @@ static void pptp_nat_expected(struct ip_conntrack *ct, DEBUGP("not found!\n"); } - ip_nat_follow_master(ct, exp); + /* 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.ip; + if (exp->dir == IP_CT_DIR_ORIGINAL) { + range.flags |= IP_NAT_RANGE_PROTO_SPECIFIED; + range.min = range.max = exp->saved_proto; + } + /* hook doesn't matter, but it has to do source manip */ + ip_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; + range.min_ip = range.max_ip + = ct->master->tuplehash[!exp->dir].tuple.src.ip; + if (exp->dir == IP_CT_DIR_REPLY) { + range.flags |= IP_NAT_RANGE_PROTO_SPECIFIED; + range.min = range.max = exp->saved_proto; + } + /* hook doesn't matter, but it has to do destination manip */ + ip_nat_setup_info(ct, &range, NF_IP_PRE_ROUTING); } /* outbound packets == from PNS to PAC */ @@ -213,7 +237,7 @@ pptp_exp_gre(struct ip_conntrack_expect *expect_orig, /* alter expectation for PNS->PAC direction */ invert_tuplepr(&inv_t, &expect_orig->tuple); - expect_orig->saved_proto.gre.key = htons(nat_pptp_info->pac_call_id); + expect_orig->saved_proto.gre.key = htons(ct_pptp_info->pns_call_id); expect_orig->tuple.src.u.gre.key = htons(nat_pptp_info->pns_call_id); expect_orig->tuple.dst.u.gre.key = htons(ct_pptp_info->pac_call_id); expect_orig->dir = IP_CT_DIR_ORIGINAL; -- 2.20.1