[PATCH 04/25] netfilter: nf_conntrack: restrict NAT helper invocation to IPv4

From: pablo@netfilter.org
Date: 2012-09-03 23:55:34
Also in: netfilter-devel
Subsystem: netfilter, networking [general], the rest · Maintainers: Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds

From: Patrick McHardy <redacted>

The NAT helpers currently only handle IPv4 packets correctly. Restrict
invocation of the helpers to IPv4 in preparation of IPv6 NAT.

Signed-off-by: Patrick McHardy <redacted>
---
 net/netfilter/nf_conntrack_amanda.c    |    3 ++-
 net/netfilter/nf_conntrack_ftp.c       |    3 ++-
 net/netfilter/nf_conntrack_h323_main.c |   41 ++++++++++++++++++++++----------
 net/netfilter/nf_conntrack_irc.c       |    3 ++-
 net/netfilter/nf_conntrack_sip.c       |   18 +++++++++-----
 net/netfilter/nf_conntrack_tftp.c      |    3 ++-
 6 files changed, 49 insertions(+), 22 deletions(-)

diff --git a/net/netfilter/nf_conntrack_amanda.c b/net/netfilter/nf_conntrack_amanda.c
index f2de8c5..184c0dc 100644
--- a/net/netfilter/nf_conntrack_amanda.c
+++ b/net/netfilter/nf_conntrack_amanda.c

@@ -154,7 +154,8 @@ static int amanda_help(struct sk_buff *skb,
 				  IPPROTO_TCP, NULL, &port);
 
 		nf_nat_amanda = rcu_dereference(nf_nat_amanda_hook);
-		if (nf_nat_amanda && ct->status & IPS_NAT_MASK)
+		if (nf_nat_amanda && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+		    ct->status & IPS_NAT_MASK)
 			ret = nf_nat_amanda(skb, ctinfo, off - dataoff,
 					    len, exp);
 		else if (nf_ct_expect_related(exp) != 0)

diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c
index 4bb771d..3e1587e 100644
--- a/net/netfilter/nf_conntrack_ftp.c
+++ b/net/netfilter/nf_conntrack_ftp.c

@@ -487,7 +487,8 @@ static int help(struct sk_buff *skb,
 	/* Now, NAT might want to mangle the packet, and register the
 	 * (possibly changed) expectation itself. */
 	nf_nat_ftp = rcu_dereference(nf_nat_ftp_hook);
-	if (nf_nat_ftp && ct->status & IPS_NAT_MASK)
+	if (nf_nat_ftp && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK)
 		ret = nf_nat_ftp(skb, ctinfo, search[dir][i].ftptype,
 				 matchoff, matchlen, exp);
 	else {

diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c
index 4283b20..517c5e3 100644
--- a/net/netfilter/nf_conntrack_h323_main.c
+++ b/net/netfilter/nf_conntrack_h323_main.c

@@ -295,6 +295,7 @@ static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
 		   &ct->tuplehash[!dir].tuple.dst.u3,
 		   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 		   (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
+		   nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 		   ct->status & IPS_NAT_MASK) {
 		/* NAT needed */
 		ret = nat_rtp_rtcp(skb, ct, ctinfo, data, dataoff,

@@ -353,6 +354,7 @@ static int expect_t120(struct sk_buff *skb,
 		   &ct->tuplehash[!dir].tuple.dst.u3,
 		   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 	    (nat_t120 = rcu_dereference(nat_t120_hook)) &&
+	    nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 	    ct->status & IPS_NAT_MASK) {
 		/* NAT needed */
 		ret = nat_t120(skb, ct, ctinfo, data, dataoff, taddr,

@@ -688,6 +690,7 @@ static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
 		   &ct->tuplehash[!dir].tuple.dst.u3,
 		   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 	    (nat_h245 = rcu_dereference(nat_h245_hook)) &&
+	    nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 	    ct->status & IPS_NAT_MASK) {
 		/* NAT needed */
 		ret = nat_h245(skb, ct, ctinfo, data, dataoff, taddr,

@@ -811,6 +814,7 @@ static int expect_callforwarding(struct sk_buff *skb,
 		   &ct->tuplehash[!dir].tuple.dst.u3,
 		   sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
 	    (nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
+	    nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 	    ct->status & IPS_NAT_MASK) {
 		/* Need NAT */
 		ret = nat_callforwarding(skb, ct, ctinfo, data, dataoff,

@@ -852,7 +856,8 @@ static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
 
 	set_h225_addr = rcu_dereference(set_h225_addr_hook);
 	if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
-	    (set_h225_addr) && ct->status & IPS_NAT_MASK &&
+	    (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK &&
 	    get_h225_addr(ct, *data, &setup->destCallSignalAddress,
 			  &addr, &port) &&
 	    memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {

@@ -868,7 +873,8 @@ static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
 	}
 
 	if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
-	    (set_h225_addr) && ct->status & IPS_NAT_MASK &&
+	    (set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK &&
 	    get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
 			  &addr, &port) &&
 	    memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {

@@ -1278,7 +1284,8 @@ static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
 	exp->flags = NF_CT_EXPECT_PERMANENT;	/* Accept multiple calls */
 
 	nat_q931 = rcu_dereference(nat_q931_hook);
-	if (nat_q931 && ct->status & IPS_NAT_MASK) {	/* Need NAT */
+	if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK) {	/* Need NAT */
 		ret = nat_q931(skb, ct, ctinfo, data, taddr, i, port, exp);
 	} else {		/* Conntrack only */
 		if (nf_ct_expect_related(exp) == 0) {

@@ -1306,7 +1313,8 @@ static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
 	pr_debug("nf_ct_ras: GRQ\n");
 
 	set_ras_addr = rcu_dereference(set_ras_addr_hook);
-	if (set_ras_addr && ct->status & IPS_NAT_MASK)	/* NATed */
+	if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK)	/* NATed */
 		return set_ras_addr(skb, ct, ctinfo, data,
 				    &grq->rasAddress, 1);
 	return 0;

@@ -1374,7 +1382,8 @@ static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
 		return -1;
 
 	set_ras_addr = rcu_dereference(set_ras_addr_hook);
-	if (set_ras_addr && ct->status & IPS_NAT_MASK) {
+	if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK) {
 		ret = set_ras_addr(skb, ct, ctinfo, data,
 				   rrq->rasAddress.item,
 				   rrq->rasAddress.count);

@@ -1405,7 +1414,8 @@ static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
 	pr_debug("nf_ct_ras: RCF\n");
 
 	set_sig_addr = rcu_dereference(set_sig_addr_hook);
-	if (set_sig_addr && ct->status & IPS_NAT_MASK) {
+	if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK) {
 		ret = set_sig_addr(skb, ct, ctinfo, data,
 					rcf->callSignalAddress.item,
 					rcf->callSignalAddress.count);

@@ -1453,7 +1463,8 @@ static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
 	pr_debug("nf_ct_ras: URQ\n");
 
 	set_sig_addr = rcu_dereference(set_sig_addr_hook);
-	if (set_sig_addr && ct->status & IPS_NAT_MASK) {
+	if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK) {
 		ret = set_sig_addr(skb, ct, ctinfo, data,
 				   urq->callSignalAddress.item,
 				   urq->callSignalAddress.count);

@@ -1491,6 +1502,7 @@ static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
 			  &addr, &port) &&
 	    !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
 	    port == info->sig_port[dir] &&
+	    nf_ct_l3num(ct) == NFPROTO_IPV4 &&
 	    set_h225_addr && ct->status & IPS_NAT_MASK) {
 		/* Answering ARQ */
 		return set_h225_addr(skb, data, 0,

@@ -1503,7 +1515,8 @@ static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
 	    get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
 			  &addr, &port) &&
 	    !memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
-	    set_h225_addr && ct->status & IPS_NAT_MASK) {
+	    set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK) {
 		/* Calling ARQ */
 		return set_h225_addr(skb, data, 0,
 				     &arq->srcCallSignalAddress,

@@ -1535,7 +1548,8 @@ static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
 	if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
 		/* Answering ACF */
 		set_sig_addr = rcu_dereference(set_sig_addr_hook);
-		if (set_sig_addr && ct->status & IPS_NAT_MASK)
+		if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+		    ct->status & IPS_NAT_MASK)
 			return set_sig_addr(skb, ct, ctinfo, data,
 					    &acf->destCallSignalAddress, 1);
 		return 0;

@@ -1571,7 +1585,8 @@ static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
 	pr_debug("nf_ct_ras: LRQ\n");
 
 	set_ras_addr = rcu_dereference(set_ras_addr_hook);
-	if (set_ras_addr && ct->status & IPS_NAT_MASK)
+	if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK)
 		return set_ras_addr(skb, ct, ctinfo, data,
 				    &lrq->replyAddress, 1);
 	return 0;

@@ -1628,7 +1643,8 @@ static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
 	pr_debug("nf_ct_ras: IRR\n");
 
 	set_ras_addr = rcu_dereference(set_ras_addr_hook);
-	if (set_ras_addr && ct->status & IPS_NAT_MASK) {
+	if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK) {
 		ret = set_ras_addr(skb, ct, ctinfo, data,
 				   &irr->rasAddress, 1);
 		if (ret < 0)

@@ -1636,7 +1652,8 @@ static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
 	}
 
 	set_sig_addr = rcu_dereference(set_sig_addr_hook);
-	if (set_sig_addr && ct->status & IPS_NAT_MASK) {
+	if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK) {
 		ret = set_sig_addr(skb, ct, ctinfo, data,
 					irr->callSignalAddress.item,
 					irr->callSignalAddress.count);

diff --git a/net/netfilter/nf_conntrack_irc.c b/net/netfilter/nf_conntrack_irc.c
index 009c52c..e06dc2f 100644
--- a/net/netfilter/nf_conntrack_irc.c
+++ b/net/netfilter/nf_conntrack_irc.c

@@ -204,7 +204,8 @@ static int help(struct sk_buff *skb, unsigned int protoff,
 					  IPPROTO_TCP, NULL, &port);
 
 			nf_nat_irc = rcu_dereference(nf_nat_irc_hook);
-			if (nf_nat_irc && ct->status & IPS_NAT_MASK)
+			if (nf_nat_irc && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+			    ct->status & IPS_NAT_MASK)
 				ret = nf_nat_irc(skb, ctinfo,
 						 addr_beg_p - ib_ptr,
 						 addr_end_p - addr_beg_p,

diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 5c0a112..d08e0ba 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c

@@ -981,7 +981,8 @@ static int set_expected_rtp_rtcp(struct sk_buff *skb, unsigned int dataoff,
 			  IPPROTO_UDP, NULL, &rtcp_port);
 
 	nf_nat_sdp_media = rcu_dereference(nf_nat_sdp_media_hook);
-	if (nf_nat_sdp_media && ct->status & IPS_NAT_MASK && !direct_rtp)
+	if (nf_nat_sdp_media && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK && !direct_rtp)
 		ret = nf_nat_sdp_media(skb, dataoff, dptr, datalen,
 				       rtp_exp, rtcp_exp,
 				       mediaoff, medialen, daddr);

@@ -1104,7 +1105,8 @@ static int process_sdp(struct sk_buff *skb, unsigned int dataoff,
 			return ret;
 
 		/* Update media connection address if present */
-		if (maddr_len && nf_nat_sdp_addr && ct->status & IPS_NAT_MASK) {
+		if (maddr_len && nf_nat_sdp_addr &&
+		    nf_ct_l3num(ct) == NFPROTO_IPV4 && ct->status & IPS_NAT_MASK) {
 			ret = nf_nat_sdp_addr(skb, dataoff, dptr, datalen,
 					      mediaoff, c_hdr, SDP_HDR_MEDIA,
 					      &rtp_addr);

@@ -1116,7 +1118,8 @@ static int process_sdp(struct sk_buff *skb, unsigned int dataoff,
 
 	/* Update session connection and owner addresses */
 	nf_nat_sdp_session = rcu_dereference(nf_nat_sdp_session_hook);
-	if (nf_nat_sdp_session && ct->status & IPS_NAT_MASK)
+	if (nf_nat_sdp_session && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK)
 		ret = nf_nat_sdp_session(skb, dataoff, dptr, datalen, sdpoff,
 					 &rtp_addr);

@@ -1275,7 +1278,8 @@ static int process_register_request(struct sk_buff *skb, unsigned int dataoff,
 	exp->flags = NF_CT_EXPECT_PERMANENT | NF_CT_EXPECT_INACTIVE;
 
 	nf_nat_sip_expect = rcu_dereference(nf_nat_sip_expect_hook);
-	if (nf_nat_sip_expect && ct->status & IPS_NAT_MASK)
+	if (nf_nat_sip_expect && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK)
 		ret = nf_nat_sip_expect(skb, dataoff, dptr, datalen, exp,
 					matchoff, matchlen);
 	else {

@@ -1453,7 +1457,8 @@ static int process_sip_msg(struct sk_buff *skb, struct nf_conn *ct,
 	else
 		ret = process_sip_response(skb, dataoff, dptr, datalen);
 
-	if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) {
+	if (ret == NF_ACCEPT && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK) {
 		nf_nat_sip = rcu_dereference(nf_nat_sip_hook);
 		if (nf_nat_sip && !nf_nat_sip(skb, dataoff, dptr, datalen))
 			ret = NF_DROP;

@@ -1534,7 +1539,8 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff,
 		datalen  = datalen + diff - msglen;
 	}
 
-	if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) {
+	if (ret == NF_ACCEPT && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+	    ct->status & IPS_NAT_MASK) {
 		nf_nat_sip_seq_adjust = rcu_dereference(nf_nat_sip_seq_adjust_hook);
 		if (nf_nat_sip_seq_adjust)
 			nf_nat_sip_seq_adjust(skb, tdiff);

diff --git a/net/netfilter/nf_conntrack_tftp.c b/net/netfilter/nf_conntrack_tftp.c
index 81fc61c..9363e1c 100644
--- a/net/netfilter/nf_conntrack_tftp.c
+++ b/net/netfilter/nf_conntrack_tftp.c

@@ -72,7 +72,8 @@ static int tftp_help(struct sk_buff *skb,
 		nf_ct_dump_tuple(&exp->tuple);
 
 		nf_nat_tftp = rcu_dereference(nf_nat_tftp_hook);
-		if (nf_nat_tftp && ct->status & IPS_NAT_MASK)
+		if (nf_nat_tftp && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
+		    ct->status & IPS_NAT_MASK)
 			ret = nf_nat_tftp(skb, ctinfo, exp);
 		else if (nf_ct_expect_related(exp) != 0)
 			ret = NF_DROP;

-- 
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