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[NETFILTER] PPTP helper: fix PNS-PAC expectation call id

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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 <philipc@snapgear.com>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Philip Craig 2005-11-09 13:01:53 -08:00 committed by David S. Miller
parent 81e5c27d08
commit 5978a9b82c
1 changed files with 26 additions and 2 deletions
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28
net/ipv4/netfilter/ip_nat_helper_pptp.c
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@ -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;