netfilter 00/08: SIP conntrack TCP/T.38 FAX support

netfilter 00/08: SIP conntrack TCP/T.38 FAX support

[Patrick McHardy]

Following is the final version of my SIP conntrack TCP/T.38 FAX patches.

I've done some more testing and everything appears to work fine, so I'll
commit them to the nf-next tree sometime today. If anyone has comments
or wants to add a Tested-by: tag, please do so within the next hours.

The only change since the last posting is removal of some debugging code.


 include/linux/netfilter/nf_conntrack_sip.h  |   19 ++-
 include/net/netfilter/nf_conntrack.h        |    2 +-
 include/net/netfilter/nf_conntrack_expect.h |    1 +
 include/net/netfilter/nf_nat_helper.h       |   32 ++-
 net/ipv4/netfilter/nf_nat_helper.c          |   39 ++--
 net/ipv4/netfilter/nf_nat_sip.c             |  158 ++++++++-----
 net/netfilter/nf_conntrack_expect.c         |    9 +
 net/netfilter/nf_conntrack_netlink.c        |    4 +
 net/netfilter/nf_conntrack_sip.c            |  327 +++++++++++++++++++++------
 9 files changed, 433 insertions(+), 158 deletions(-)

Patrick McHardy (8):
      netfilter: ctnetlink: dump expectation helper name
      netfilter: nf_conntrack: show helper and class in /proc/net/nf_conntrack_expect
      netfilter: nf_conntrack_sip: fix ct_sip_parse_request() REGISTER request parsing
      netfilter: nf_conntrack_sip: pass data offset to NAT functions
      netfilter: nf_conntrack_sip: add TCP support
      netfilter: nf_nat: support mangling a single TCP packet multiple times
      netfilter: nf_nat_sip: add TCP support
      netfilter: nf_conntrack_sip: add T.38 FAX support

netfilter 01/08: ctnetlink: dump expectation helper name

[Patrick McHardy]

commit 3844404984222e1b9e6c32b90592fa7ecb51ee28
Author: Patrick McHardy <kaber@trash.net>
Date:   Thu Feb 11 07:40:29 2010 +0100

    netfilter: ctnetlink: dump expectation helper name
    
    Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 5c103b8..db35eda 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1512,6 +1512,7 @@ ctnetlink_exp_dump_expect(struct sk_buff *skb,
 			  const struct nf_conntrack_expect *exp)
 {
 	struct nf_conn *master = exp->master;
+	struct nf_conntrack_helper *helper;
 	long timeout = (exp->timeout.expires - jiffies) / HZ;
 
 	if (timeout < 0)
@@ -1528,6 +1529,9 @@ ctnetlink_exp_dump_expect(struct sk_buff *skb,
 
 	NLA_PUT_BE32(skb, CTA_EXPECT_TIMEOUT, htonl(timeout));
 	NLA_PUT_BE32(skb, CTA_EXPECT_ID, htonl((unsigned long)exp));
+	helper = rcu_dereference(nfct_help(master)->helper);
+	if (helper)
+		NLA_PUT_STRING(skb, CTA_EXPECT_HELP_NAME, helper->name);
 
 	return 0;
 

netfilter 02/08: nf_conntrack: show helper and class in /proc/net/nf_conntrack_expect

[Patrick McHardy]

commit 4e4aa88c264e9f8d013e3742e48a6bea37ca1c4c
Author: Patrick McHardy <kaber@trash.net>
Date:   Thu Feb 11 07:40:30 2010 +0100

    netfilter: nf_conntrack: show helper and class in /proc/net/nf_conntrack_expect
    
    Make the output a bit more informative by showing the helper an expectation
    belongs to and the expectation class.
    
    Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h
index 9a2b9cb..917e170 100644
--- a/include/net/netfilter/nf_conntrack_expect.h
+++ b/include/net/netfilter/nf_conntrack_expect.h
@@ -66,6 +66,7 @@ static inline struct net *nf_ct_exp_net(struct nf_conntrack_expect *exp)
 struct nf_conntrack_expect_policy {
 	unsigned int	max_expected;
 	unsigned int	timeout;
+	const char	*name;
 };
 
 #define NF_CT_EXPECT_CLASS_DEFAULT	0
diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 2f25ff6..33b85f8 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -500,6 +500,7 @@ static void exp_seq_stop(struct seq_file *seq, void *v)
 static int exp_seq_show(struct seq_file *s, void *v)
 {
 	struct nf_conntrack_expect *expect;
+	struct nf_conntrack_helper *helper;
 	struct hlist_node *n = v;
 	char *delim = "";
 
@@ -525,6 +526,14 @@ static int exp_seq_show(struct seq_file *s, void *v)
 	if (expect->flags & NF_CT_EXPECT_INACTIVE)
 		seq_printf(s, "%sINACTIVE", delim);
 
+	helper = rcu_dereference(nfct_help(expect->master)->helper);
+	if (helper) {
+		seq_printf(s, "%s%s", expect->flags ? " " : "", helper->name);
+		if (helper->expect_policy[expect->class].name)
+			seq_printf(s, "/%s",
+				   helper->expect_policy[expect->class].name);
+	}
+
 	return seq_putc(s, '\n');
 }
 
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 023966b..419c5ca 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -1305,14 +1305,17 @@ static char sip_names[MAX_PORTS][2][sizeof("sip-65535")] __read_mostly;
 
 static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = {
 	[SIP_EXPECT_SIGNALLING] = {
+		.name		= "signalling",
 		.max_expected	= 1,
 		.timeout	= 3 * 60,
 	},
 	[SIP_EXPECT_AUDIO] = {
+		.name		= "audio",
 		.max_expected	= 2 * IP_CT_DIR_MAX,
 		.timeout	= 3 * 60,
 	},
 	[SIP_EXPECT_VIDEO] = {
+		.name		= "video",
 		.max_expected	= 2 * IP_CT_DIR_MAX,
 		.timeout	= 3 * 60,
 	},

Re: netfilter 02/08: nf_conntrack: show helper and class in /proc/net/nf_conntrack_expect

[Jan Engelhardt]

On Thursday 2010-02-11 08:39, Patrick McHardy wrote:

>commit 4e4aa88c264e9f8d013e3742e48a6bea37ca1c4c
>Author: Patrick McHardy <kaber@trash.net>
>Date:   Thu Feb 11 07:40:30 2010 +0100
>
>    netfilter: nf_conntrack: show helper and class in /proc/net/nf_conntrack_expect

Were not there any plans on obsoleting these procfs files?

Re: netfilter 02/08: nf_conntrack: show helper and class in /proc/net/nf_conntrack_expect

[Patrick McHardy]

Jan Engelhardt wrote:
> On Thursday 2010-02-11 08:39, Patrick McHardy wrote:
> 
>> commit 4e4aa88c264e9f8d013e3742e48a6bea37ca1c4c
>> Author: Patrick McHardy <kaber@trash.net>
>> Date:   Thu Feb 11 07:40:30 2010 +0100
>>
>>    netfilter: nf_conntrack: show helper and class in /proc/net/nf_conntrack_expect
> 
> Were not there any plans on obsoleting these procfs files?
> 

Not from me, I often find them useful.

netfilter 03/08: nf_conntrack_sip: fix ct_sip_parse_request() REGISTER request parsing

[Patrick McHardy]

commit b595ec74123dc71c56401feec6c35c822a8fc310
Author: Patrick McHardy <kaber@trash.net>
Date:   Thu Feb 11 07:40:30 2010 +0100

    netfilter: nf_conntrack_sip: fix ct_sip_parse_request() REGISTER request parsing
    
    When requests are parsed, the "sip:" part of the SIP URI should be skipped.
    
    Usually this doesn't matter because address parsing skips forward until after
    the username part, but in case REGISTER requests it doesn't contain a username
    and the address can not be parsed.
    
    Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 419c5ca..0ca2f2b 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -236,12 +236,13 @@ int ct_sip_parse_request(const struct nf_conn *ct,
 		return 0;
 
 	/* Find SIP URI */
-	limit -= strlen("sip:");
-	for (; dptr < limit; dptr++) {
+	for (; dptr < limit - strlen("sip:"); dptr++) {
 		if (*dptr == '\r' || *dptr == '\n')
 			return -1;
-		if (strnicmp(dptr, "sip:", strlen("sip:")) == 0)
+		if (strnicmp(dptr, "sip:", strlen("sip:")) == 0) {
+			dptr += strlen("sip:");
 			break;
+		}
 	}
 	if (!skp_epaddr_len(ct, dptr, limit, &shift))
 		return 0;

netfilter 04/08: nf_conntrack_sip: pass data offset to NAT functions

[Patrick McHardy]

commit 49b09299e02a5b322918f676c97b294f9a8eac4a
Author: Patrick McHardy <kaber@trash.net>
Date:   Thu Feb 11 07:40:32 2010 +0100

    netfilter: nf_conntrack_sip: pass data offset to NAT functions
    
    When using TCP multiple SIP messages might be present in a single packet.
    A following patch will parse them by setting the dptr to the beginning of
    each message. The NAT helper needs to reload the dptr value after mangling
    the packet however, so it needs to know the offset of the message to the
    beginning of the packet.
    
    Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h
index 23aa2ec..2c6950b 100644
--- a/include/linux/netfilter/nf_conntrack_sip.h
+++ b/include/linux/netfilter/nf_conntrack_sip.h
@@ -34,10 +34,10 @@ struct sdp_media_type {
 struct sip_handler {
 	const char	*method;
 	unsigned int	len;
-	int		(*request)(struct sk_buff *skb,
+	int		(*request)(struct sk_buff *skb, unsigned int dataoff,
 				   const char **dptr, unsigned int *datalen,
 				   unsigned int cseq);
-	int		(*response)(struct sk_buff *skb,
+	int		(*response)(struct sk_buff *skb, unsigned int dataoff,
 				    const char **dptr, unsigned int *datalen,
 				    unsigned int cseq, unsigned int code);
 };
@@ -100,33 +100,39 @@ enum sdp_header_types {
 };
 
 extern unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb,
+				       unsigned int dataoff,
 				       const char **dptr,
 				       unsigned int *datalen);
 extern unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb,
+					      unsigned int dataoff,
 					      const char **dptr,
 					      unsigned int *datalen,
 					      struct nf_conntrack_expect *exp,
 					      unsigned int matchoff,
 					      unsigned int matchlen);
 extern unsigned int (*nf_nat_sdp_addr_hook)(struct sk_buff *skb,
-					    const char **dptr,
 					    unsigned int dataoff,
+					    const char **dptr,
 					    unsigned int *datalen,
+					    unsigned int sdpoff,
 					    enum sdp_header_types type,
 					    enum sdp_header_types term,
 					    const union nf_inet_addr *addr);
 extern unsigned int (*nf_nat_sdp_port_hook)(struct sk_buff *skb,
+					    unsigned int dataoff,
 					    const char **dptr,
 					    unsigned int *datalen,
 					    unsigned int matchoff,
 					    unsigned int matchlen,
 					    u_int16_t port);
 extern unsigned int (*nf_nat_sdp_session_hook)(struct sk_buff *skb,
-					       const char **dptr,
 					       unsigned int dataoff,
+					       const char **dptr,
 					       unsigned int *datalen,
+					       unsigned int sdpoff,
 					       const union nf_inet_addr *addr);
 extern unsigned int (*nf_nat_sdp_media_hook)(struct sk_buff *skb,
+					     unsigned int dataoff,
 					     const char **dptr,
 					     unsigned int *datalen,
 					     struct nf_conntrack_expect *rtp_exp,
diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index 07d61a5..2454ea5 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -29,7 +29,7 @@ MODULE_DESCRIPTION("SIP NAT helper");
 MODULE_ALIAS("ip_nat_sip");
 
 
-static unsigned int mangle_packet(struct sk_buff *skb,
+static unsigned int mangle_packet(struct sk_buff *skb, unsigned int dataoff,
 				  const char **dptr, unsigned int *datalen,
 				  unsigned int matchoff, unsigned int matchlen,
 				  const char *buffer, unsigned int buflen)
@@ -42,12 +42,12 @@ static unsigned int mangle_packet(struct sk_buff *skb,
 		return 0;
 
 	/* Reload data pointer and adjust datalen value */
-	*dptr = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr);
+	*dptr = skb->data + dataoff;
 	*datalen += buflen - matchlen;
 	return 1;
 }
 
-static int map_addr(struct sk_buff *skb,
+static int map_addr(struct sk_buff *skb, unsigned int dataoff,
 		    const char **dptr, unsigned int *datalen,
 		    unsigned int matchoff, unsigned int matchlen,
 		    union nf_inet_addr *addr, __be16 port)
@@ -76,11 +76,11 @@ static int map_addr(struct sk_buff *skb,
 
 	buflen = sprintf(buffer, "%pI4:%u", &newaddr, ntohs(newport));
 
-	return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+	return mangle_packet(skb, dataoff, dptr, datalen, matchoff, matchlen,
 			     buffer, buflen);
 }
 
-static int map_sip_addr(struct sk_buff *skb,
+static int map_sip_addr(struct sk_buff *skb, unsigned int dataoff,
 			const char **dptr, unsigned int *datalen,
 			enum sip_header_types type)
 {
@@ -93,16 +93,17 @@ static int map_sip_addr(struct sk_buff *skb,
 	if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, type, NULL,
 				    &matchoff, &matchlen, &addr, &port) <= 0)
 		return 1;
-	return map_addr(skb, dptr, datalen, matchoff, matchlen, &addr, port);
+	return map_addr(skb, dataoff, dptr, datalen, matchoff, matchlen,
+			&addr, port);
 }
 
-static unsigned int ip_nat_sip(struct sk_buff *skb,
+static unsigned int ip_nat_sip(struct sk_buff *skb, unsigned int dataoff,
 			       const char **dptr, unsigned int *datalen)
 {
 	enum ip_conntrack_info ctinfo;
 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
-	unsigned int dataoff, matchoff, matchlen;
+	unsigned int coff, matchoff, matchlen;
 	union nf_inet_addr addr;
 	__be16 port;
 	int request, in_header;
@@ -112,7 +113,7 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
 		if (ct_sip_parse_request(ct, *dptr, *datalen,
 					 &matchoff, &matchlen,
 					 &addr, &port) > 0 &&
-		    !map_addr(skb, dptr, datalen, matchoff, matchlen,
+		    !map_addr(skb, dataoff, dptr, datalen, matchoff, matchlen,
 			      &addr, port))
 			return NF_DROP;
 		request = 1;
@@ -138,7 +139,7 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
 				goto next;
 		}
 
-		if (!map_addr(skb, dptr, datalen, matchoff, matchlen,
+		if (!map_addr(skb, dataoff, dptr, datalen, matchoff, matchlen,
 			      &addr, port))
 			return NF_DROP;
 
@@ -153,8 +154,8 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
 		    addr.ip != ct->tuplehash[!dir].tuple.dst.u3.ip) {
 			buflen = sprintf(buffer, "%pI4",
 					&ct->tuplehash[!dir].tuple.dst.u3.ip);
-			if (!mangle_packet(skb, dptr, datalen, poff, plen,
-					   buffer, buflen))
+			if (!mangle_packet(skb, dataoff, dptr, datalen,
+					   poff, plen, buffer, buflen))
 				return NF_DROP;
 		}
 
@@ -167,8 +168,8 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
 		    addr.ip != ct->tuplehash[!dir].tuple.src.u3.ip) {
 			buflen = sprintf(buffer, "%pI4",
 					&ct->tuplehash[!dir].tuple.src.u3.ip);
-			if (!mangle_packet(skb, dptr, datalen, poff, plen,
-					   buffer, buflen))
+			if (!mangle_packet(skb, dataoff, dptr, datalen,
+					   poff, plen, buffer, buflen))
 				return NF_DROP;
 		}
 
@@ -181,27 +182,27 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
 		    htons(n) != ct->tuplehash[!dir].tuple.src.u.udp.port) {
 			__be16 p = ct->tuplehash[!dir].tuple.src.u.udp.port;
 			buflen = sprintf(buffer, "%u", ntohs(p));
-			if (!mangle_packet(skb, dptr, datalen, poff, plen,
-					   buffer, buflen))
+			if (!mangle_packet(skb, dataoff, dptr, datalen,
+					   poff, plen, buffer, buflen))
 				return NF_DROP;
 		}
 	}
 
 next:
 	/* Translate Contact headers */
-	dataoff = 0;
+	coff = 0;
 	in_header = 0;
-	while (ct_sip_parse_header_uri(ct, *dptr, &dataoff, *datalen,
+	while (ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen,
 				       SIP_HDR_CONTACT, &in_header,
 				       &matchoff, &matchlen,
 				       &addr, &port) > 0) {
-		if (!map_addr(skb, dptr, datalen, matchoff, matchlen,
+		if (!map_addr(skb, dataoff, dptr, datalen, matchoff, matchlen,
 			      &addr, port))
 			return NF_DROP;
 	}
 
-	if (!map_sip_addr(skb, dptr, datalen, SIP_HDR_FROM) ||
-	    !map_sip_addr(skb, dptr, datalen, SIP_HDR_TO))
+	if (!map_sip_addr(skb, dataoff, dptr, datalen, SIP_HDR_FROM) ||
+	    !map_sip_addr(skb, dataoff, dptr, datalen, SIP_HDR_TO))
 		return NF_DROP;
 	return NF_ACCEPT;
 }
@@ -232,7 +233,7 @@ static void ip_nat_sip_expected(struct nf_conn *ct,
 	}
 }
 
-static unsigned int ip_nat_sip_expect(struct sk_buff *skb,
+static unsigned int ip_nat_sip_expect(struct sk_buff *skb, unsigned int dataoff,
 				      const char **dptr, unsigned int *datalen,
 				      struct nf_conntrack_expect *exp,
 				      unsigned int matchoff,
@@ -279,8 +280,8 @@ static unsigned int ip_nat_sip_expect(struct sk_buff *skb,
 	if (exp->tuple.dst.u3.ip != exp->saved_ip ||
 	    exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port) {
 		buflen = sprintf(buffer, "%pI4:%u", &newip, port);
-		if (!mangle_packet(skb, dptr, datalen, matchoff, matchlen,
-				   buffer, buflen))
+		if (!mangle_packet(skb, dataoff, dptr, datalen,
+				   matchoff, matchlen, buffer, buflen))
 			goto err;
 	}
 	return NF_ACCEPT;
@@ -290,7 +291,7 @@ err:
 	return NF_DROP;
 }
 
-static int mangle_content_len(struct sk_buff *skb,
+static int mangle_content_len(struct sk_buff *skb, unsigned int dataoff,
 			      const char **dptr, unsigned int *datalen)
 {
 	enum ip_conntrack_info ctinfo;
@@ -312,12 +313,13 @@ static int mangle_content_len(struct sk_buff *skb,
 		return 0;
 
 	buflen = sprintf(buffer, "%u", c_len);
-	return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+	return mangle_packet(skb, dataoff, dptr, datalen, matchoff, matchlen,
 			     buffer, buflen);
 }
 
-static int mangle_sdp_packet(struct sk_buff *skb, const char **dptr,
-			     unsigned int dataoff, unsigned int *datalen,
+static int mangle_sdp_packet(struct sk_buff *skb, unsigned int dataoff,
+			     const char **dptr, unsigned int *datalen,
+			     unsigned int sdpoff,
 			     enum sdp_header_types type,
 			     enum sdp_header_types term,
 			     char *buffer, int buflen)
@@ -326,16 +328,16 @@ static int mangle_sdp_packet(struct sk_buff *skb, const char **dptr,
 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
 	unsigned int matchlen, matchoff;
 
-	if (ct_sip_get_sdp_header(ct, *dptr, dataoff, *datalen, type, term,
+	if (ct_sip_get_sdp_header(ct, *dptr, sdpoff, *datalen, type, term,
 				  &matchoff, &matchlen) <= 0)
 		return -ENOENT;
-	return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+	return mangle_packet(skb, dataoff, dptr, datalen, matchoff, matchlen,
 			     buffer, buflen) ? 0 : -EINVAL;
 }
 
-static unsigned int ip_nat_sdp_addr(struct sk_buff *skb, const char **dptr,
-				    unsigned int dataoff,
-				    unsigned int *datalen,
+static unsigned int ip_nat_sdp_addr(struct sk_buff *skb, unsigned int dataoff,
+				    const char **dptr, unsigned int *datalen,
+				    unsigned int sdpoff,
 				    enum sdp_header_types type,
 				    enum sdp_header_types term,
 				    const union nf_inet_addr *addr)
@@ -344,16 +346,15 @@ static unsigned int ip_nat_sdp_addr(struct sk_buff *skb, const char **dptr,
 	unsigned int buflen;
 
 	buflen = sprintf(buffer, "%pI4", &addr->ip);
-	if (mangle_sdp_packet(skb, dptr, dataoff, datalen, type, term,
+	if (mangle_sdp_packet(skb, dataoff, dptr, datalen, sdpoff, type, term,
 			      buffer, buflen))
 		return 0;
 
-	return mangle_content_len(skb, dptr, datalen);
+	return mangle_content_len(skb, dataoff, dptr, datalen);
 }
 
-static unsigned int ip_nat_sdp_port(struct sk_buff *skb,
-				    const char **dptr,
-				    unsigned int *datalen,
+static unsigned int ip_nat_sdp_port(struct sk_buff *skb, unsigned int dataoff,
+				    const char **dptr, unsigned int *datalen,
 				    unsigned int matchoff,
 				    unsigned int matchlen,
 				    u_int16_t port)
@@ -362,16 +363,16 @@ static unsigned int ip_nat_sdp_port(struct sk_buff *skb,
 	unsigned int buflen;
 
 	buflen = sprintf(buffer, "%u", port);
-	if (!mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+	if (!mangle_packet(skb, dataoff, dptr, datalen, matchoff, matchlen,
 			   buffer, buflen))
 		return 0;
 
-	return mangle_content_len(skb, dptr, datalen);
+	return mangle_content_len(skb, dataoff, dptr, datalen);
 }
 
-static unsigned int ip_nat_sdp_session(struct sk_buff *skb, const char **dptr,
-				       unsigned int dataoff,
-				       unsigned int *datalen,
+static unsigned int ip_nat_sdp_session(struct sk_buff *skb, unsigned int dataoff,
+				       const char **dptr, unsigned int *datalen,
+				       unsigned int sdpoff,
 				       const union nf_inet_addr *addr)
 {
 	char buffer[sizeof("nnn.nnn.nnn.nnn")];
@@ -379,12 +380,12 @@ static unsigned int ip_nat_sdp_session(struct sk_buff *skb, const char **dptr,
 
 	/* Mangle session description owner and contact addresses */
 	buflen = sprintf(buffer, "%pI4", &addr->ip);
-	if (mangle_sdp_packet(skb, dptr, dataoff, datalen,
+	if (mangle_sdp_packet(skb, dataoff, dptr, datalen, sdpoff,
 			       SDP_HDR_OWNER_IP4, SDP_HDR_MEDIA,
 			       buffer, buflen))
 		return 0;
 
-	switch (mangle_sdp_packet(skb, dptr, dataoff, datalen,
+	switch (mangle_sdp_packet(skb, dataoff, dptr, datalen, sdpoff,
 				  SDP_HDR_CONNECTION_IP4, SDP_HDR_MEDIA,
 				  buffer, buflen)) {
 	case 0:
@@ -401,14 +402,13 @@ static unsigned int ip_nat_sdp_session(struct sk_buff *skb, const char **dptr,
 		return 0;
 	}
 
-	return mangle_content_len(skb, dptr, datalen);
+	return mangle_content_len(skb, dataoff, dptr, datalen);
 }
 
 /* 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_media(struct sk_buff *skb,
-				     const char **dptr,
-				     unsigned int *datalen,
+static unsigned int ip_nat_sdp_media(struct sk_buff *skb, unsigned int dataoff,
+				     const char **dptr, unsigned int *datalen,
 				     struct nf_conntrack_expect *rtp_exp,
 				     struct nf_conntrack_expect *rtcp_exp,
 				     unsigned int mediaoff,
@@ -456,7 +456,8 @@ static unsigned int ip_nat_sdp_media(struct sk_buff *skb,
 
 	/* Update media port. */
 	if (rtp_exp->tuple.dst.u.udp.port != rtp_exp->saved_proto.udp.port &&
-	    !ip_nat_sdp_port(skb, dptr, datalen, mediaoff, medialen, port))
+	    !ip_nat_sdp_port(skb, dataoff, dptr, datalen,
+			     mediaoff, medialen, port))
 		goto err2;
 
 	return NF_ACCEPT;
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 0ca2f2b..0ec37d6 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -50,12 +50,13 @@ module_param(sip_direct_media, int, 0600);
 MODULE_PARM_DESC(sip_direct_media, "Expect Media streams between signalling "
 				   "endpoints only (default 1)");
 
-unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb,
+unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb, unsigned int dataoff,
 				const char **dptr,
 				unsigned int *datalen) __read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_sip_hook);
 
 unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb,
+				       unsigned int dataoff,
 				       const char **dptr,
 				       unsigned int *datalen,
 				       struct nf_conntrack_expect *exp,
@@ -63,17 +64,17 @@ unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb,
 				       unsigned int matchlen) __read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_sip_expect_hook);
 
-unsigned int (*nf_nat_sdp_addr_hook)(struct sk_buff *skb,
+unsigned int (*nf_nat_sdp_addr_hook)(struct sk_buff *skb, unsigned int dataoff,
 				     const char **dptr,
-				     unsigned int dataoff,
 				     unsigned int *datalen,
+				     unsigned int sdpoff,
 				     enum sdp_header_types type,
 				     enum sdp_header_types term,
 				     const union nf_inet_addr *addr)
 				     __read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_sdp_addr_hook);
 
-unsigned int (*nf_nat_sdp_port_hook)(struct sk_buff *skb,
+unsigned int (*nf_nat_sdp_port_hook)(struct sk_buff *skb, unsigned int dataoff,
 				     const char **dptr,
 				     unsigned int *datalen,
 				     unsigned int matchoff,
@@ -82,14 +83,15 @@ unsigned int (*nf_nat_sdp_port_hook)(struct sk_buff *skb,
 EXPORT_SYMBOL_GPL(nf_nat_sdp_port_hook);
 
 unsigned int (*nf_nat_sdp_session_hook)(struct sk_buff *skb,
-					const char **dptr,
 					unsigned int dataoff,
+					const char **dptr,
 					unsigned int *datalen,
+					unsigned int sdpoff,
 					const union nf_inet_addr *addr)
 					__read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_sdp_session_hook);
 
-unsigned int (*nf_nat_sdp_media_hook)(struct sk_buff *skb,
+unsigned int (*nf_nat_sdp_media_hook)(struct sk_buff *skb, unsigned int dataoff,
 				      const char **dptr,
 				      unsigned int *datalen,
 				      struct nf_conntrack_expect *rtp_exp,
@@ -729,7 +731,7 @@ static void flush_expectations(struct nf_conn *ct, bool media)
 	spin_unlock_bh(&nf_conntrack_lock);
 }
 
-static int set_expected_rtp_rtcp(struct sk_buff *skb,
+static int set_expected_rtp_rtcp(struct sk_buff *skb, unsigned int dataoff,
 				 const char **dptr, unsigned int *datalen,
 				 union nf_inet_addr *daddr, __be16 port,
 				 enum sip_expectation_classes class,
@@ -806,7 +808,7 @@ static int set_expected_rtp_rtcp(struct sk_buff *skb,
 	if (direct_rtp) {
 		nf_nat_sdp_port = rcu_dereference(nf_nat_sdp_port_hook);
 		if (nf_nat_sdp_port &&
-		    !nf_nat_sdp_port(skb, dptr, datalen,
+		    !nf_nat_sdp_port(skb, dataoff, dptr, datalen,
 				     mediaoff, medialen, ntohs(rtp_port)))
 			goto err1;
 	}
@@ -828,7 +830,8 @@ static int set_expected_rtp_rtcp(struct sk_buff *skb,
 
 	nf_nat_sdp_media = rcu_dereference(nf_nat_sdp_media_hook);
 	if (nf_nat_sdp_media && ct->status & IPS_NAT_MASK && !direct_rtp)
-		ret = nf_nat_sdp_media(skb, dptr, datalen, rtp_exp, rtcp_exp,
+		ret = nf_nat_sdp_media(skb, dataoff, dptr, datalen,
+				       rtp_exp, rtcp_exp,
 				       mediaoff, medialen, daddr);
 	else {
 		if (nf_ct_expect_related(rtp_exp) == 0) {
@@ -867,7 +870,7 @@ static const struct sdp_media_type *sdp_media_type(const char *dptr,
 	return NULL;
 }
 
-static int process_sdp(struct sk_buff *skb,
+static int process_sdp(struct sk_buff *skb, unsigned int dataoff,
 		       const char **dptr, unsigned int *datalen,
 		       unsigned int cseq)
 {
@@ -942,7 +945,7 @@ static int process_sdp(struct sk_buff *skb,
 		else
 			return NF_DROP;
 
-		ret = set_expected_rtp_rtcp(skb, dptr, datalen,
+		ret = set_expected_rtp_rtcp(skb, dataoff, dptr, datalen,
 					    &rtp_addr, htons(port), t->class,
 					    mediaoff, medialen);
 		if (ret != NF_ACCEPT)
@@ -950,8 +953,9 @@ static int process_sdp(struct sk_buff *skb,
 
 		/* Update media connection address if present */
 		if (maddr_len && nf_nat_sdp_addr && ct->status & IPS_NAT_MASK) {
-			ret = nf_nat_sdp_addr(skb, dptr, mediaoff, datalen,
-					      c_hdr, SDP_HDR_MEDIA, &rtp_addr);
+			ret = nf_nat_sdp_addr(skb, dataoff, dptr, datalen,
+					      mediaoff, c_hdr, SDP_HDR_MEDIA,
+					      &rtp_addr);
 			if (ret != NF_ACCEPT)
 				return ret;
 		}
@@ -961,14 +965,15 @@ static int process_sdp(struct sk_buff *skb,
 	/* 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)
-		ret = nf_nat_sdp_session(skb, dptr, sdpoff, datalen, &rtp_addr);
+		ret = nf_nat_sdp_session(skb, dataoff, dptr, datalen, sdpoff,
+					 &rtp_addr);
 
 	if (ret == NF_ACCEPT && i > 0)
 		help->help.ct_sip_info.invite_cseq = cseq;
 
 	return ret;
 }
-static int process_invite_response(struct sk_buff *skb,
+static int process_invite_response(struct sk_buff *skb, unsigned int dataoff,
 				   const char **dptr, unsigned int *datalen,
 				   unsigned int cseq, unsigned int code)
 {
@@ -978,13 +983,13 @@ static int process_invite_response(struct sk_buff *skb,
 
 	if ((code >= 100 && code <= 199) ||
 	    (code >= 200 && code <= 299))
-		return process_sdp(skb, dptr, datalen, cseq);
+		return process_sdp(skb, dataoff, dptr, datalen, cseq);
 	else if (help->help.ct_sip_info.invite_cseq == cseq)
 		flush_expectations(ct, true);
 	return NF_ACCEPT;
 }
 
-static int process_update_response(struct sk_buff *skb,
+static int process_update_response(struct sk_buff *skb, unsigned int dataoff,
 				   const char **dptr, unsigned int *datalen,
 				   unsigned int cseq, unsigned int code)
 {
@@ -994,13 +999,13 @@ static int process_update_response(struct sk_buff *skb,
 
 	if ((code >= 100 && code <= 199) ||
 	    (code >= 200 && code <= 299))
-		return process_sdp(skb, dptr, datalen, cseq);
+		return process_sdp(skb, dataoff, dptr, datalen, cseq);
 	else if (help->help.ct_sip_info.invite_cseq == cseq)
 		flush_expectations(ct, true);
 	return NF_ACCEPT;
 }
 
-static int process_prack_response(struct sk_buff *skb,
+static int process_prack_response(struct sk_buff *skb, unsigned int dataoff,
 				  const char **dptr, unsigned int *datalen,
 				  unsigned int cseq, unsigned int code)
 {
@@ -1010,13 +1015,13 @@ static int process_prack_response(struct sk_buff *skb,
 
 	if ((code >= 100 && code <= 199) ||
 	    (code >= 200 && code <= 299))
-		return process_sdp(skb, dptr, datalen, cseq);
+		return process_sdp(skb, dataoff, dptr, datalen, cseq);
 	else if (help->help.ct_sip_info.invite_cseq == cseq)
 		flush_expectations(ct, true);
 	return NF_ACCEPT;
 }
 
-static int process_bye_request(struct sk_buff *skb,
+static int process_bye_request(struct sk_buff *skb, unsigned int dataoff,
 			       const char **dptr, unsigned int *datalen,
 			       unsigned int cseq)
 {
@@ -1031,7 +1036,7 @@ static int process_bye_request(struct sk_buff *skb,
  * signalling connections. The expectation is marked inactive and is activated
  * when receiving a response indicating success from the registrar.
  */
-static int process_register_request(struct sk_buff *skb,
+static int process_register_request(struct sk_buff *skb, unsigned int dataoff,
 				    const char **dptr, unsigned int *datalen,
 				    unsigned int cseq)
 {
@@ -1101,7 +1106,7 @@ static int process_register_request(struct sk_buff *skb,
 
 	nf_nat_sip_expect = rcu_dereference(nf_nat_sip_expect_hook);
 	if (nf_nat_sip_expect && ct->status & IPS_NAT_MASK)
-		ret = nf_nat_sip_expect(skb, dptr, datalen, exp,
+		ret = nf_nat_sip_expect(skb, dataoff, dptr, datalen, exp,
 					matchoff, matchlen);
 	else {
 		if (nf_ct_expect_related(exp) != 0)
@@ -1117,7 +1122,7 @@ store_cseq:
 	return ret;
 }
 
-static int process_register_response(struct sk_buff *skb,
+static int process_register_response(struct sk_buff *skb, unsigned int dataoff,
 				     const char **dptr, unsigned int *datalen,
 				     unsigned int cseq, unsigned int code)
 {
@@ -1127,7 +1132,7 @@ static int process_register_response(struct sk_buff *skb,
 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 	union nf_inet_addr addr;
 	__be16 port;
-	unsigned int matchoff, matchlen, dataoff = 0;
+	unsigned int matchoff, matchlen, coff = 0;
 	unsigned int expires = 0;
 	int in_contact = 0, ret;
 
@@ -1154,7 +1159,7 @@ static int process_register_response(struct sk_buff *skb,
 	while (1) {
 		unsigned int c_expires = expires;
 
-		ret = ct_sip_parse_header_uri(ct, *dptr, &dataoff, *datalen,
+		ret = ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen,
 					      SIP_HDR_CONTACT, &in_contact,
 					      &matchoff, &matchlen,
 					      &addr, &port);
@@ -1193,13 +1198,13 @@ static const struct sip_handler sip_handlers[] = {
 	SIP_HANDLER("REGISTER", process_register_request, process_register_response),
 };
 
-static int process_sip_response(struct sk_buff *skb,
+static int process_sip_response(struct sk_buff *skb, unsigned int dataoff,
 				const char **dptr, unsigned int *datalen)
 {
 	enum ip_conntrack_info ctinfo;
 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
-	unsigned int matchoff, matchlen;
-	unsigned int code, cseq, dataoff, i;
+	unsigned int matchoff, matchlen, matchend;
+	unsigned int code, cseq, i;
 
 	if (*datalen < strlen("SIP/2.0 200"))
 		return NF_ACCEPT;
@@ -1213,7 +1218,7 @@ static int process_sip_response(struct sk_buff *skb,
 	cseq = simple_strtoul(*dptr + matchoff, NULL, 10);
 	if (!cseq)
 		return NF_DROP;
-	dataoff = matchoff + matchlen + 1;
+	matchend = matchoff + matchlen + 1;
 
 	for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) {
 		const struct sip_handler *handler;
@@ -1221,15 +1226,16 @@ static int process_sip_response(struct sk_buff *skb,
 		handler = &sip_handlers[i];
 		if (handler->response == NULL)
 			continue;
-		if (*datalen < dataoff + handler->len ||
-		    strnicmp(*dptr + dataoff, handler->method, handler->len))
+		if (*datalen < matchend + handler->len ||
+		    strnicmp(*dptr + matchend, handler->method, handler->len))
 			continue;
-		return handler->response(skb, dptr, datalen, cseq, code);
+		return handler->response(skb, dataoff, dptr, datalen,
+					 cseq, code);
 	}
 	return NF_ACCEPT;
 }
 
-static int process_sip_request(struct sk_buff *skb,
+static int process_sip_request(struct sk_buff *skb, unsigned int dataoff,
 			       const char **dptr, unsigned int *datalen)
 {
 	enum ip_conntrack_info ctinfo;
@@ -1254,7 +1260,7 @@ static int process_sip_request(struct sk_buff *skb,
 		if (!cseq)
 			return NF_DROP;
 
-		return handler->request(skb, dptr, datalen, cseq);
+		return handler->request(skb, dataoff, dptr, datalen, cseq);
 	}
 	return NF_ACCEPT;
 }
@@ -1288,13 +1294,13 @@ static int sip_help(struct sk_buff *skb,
 		return NF_ACCEPT;
 
 	if (strnicmp(dptr, "SIP/2.0 ", strlen("SIP/2.0 ")) != 0)
-		ret = process_sip_request(skb, &dptr, &datalen);
+		ret = process_sip_request(skb, dataoff, &dptr, &datalen);
 	else
-		ret = process_sip_response(skb, &dptr, &datalen);
+		ret = process_sip_response(skb, dataoff, &dptr, &datalen);
 
 	if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) {
 		nf_nat_sip = rcu_dereference(nf_nat_sip_hook);
-		if (nf_nat_sip && !nf_nat_sip(skb, &dptr, &datalen))
+		if (nf_nat_sip && !nf_nat_sip(skb, dataoff, &dptr, &datalen))
 			ret = NF_DROP;
 	}
 

netfilter 05/08: nf_conntrack_sip: add TCP support

[Patrick McHardy]

commit 52923fa05b52853ee58d1f4dac8d7110bef8f30a
Author: Patrick McHardy <kaber@trash.net>
Date:   Thu Feb 11 07:40:33 2010 +0100

    netfilter: nf_conntrack_sip: add TCP support
    
    Add TCP support, which is mandated by RFC3261 for all SIP elements.
    
    SIP over TCP is similar to UDP, except that messages are delimited
    by Content-Length: headers and multiple messages may appear in one
    packet.
    
    Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h
index 2c6950b..fa9bb89 100644
--- a/include/linux/netfilter/nf_conntrack_sip.h
+++ b/include/linux/netfilter/nf_conntrack_sip.h
@@ -84,7 +84,8 @@ enum sip_header_types {
 	SIP_HDR_FROM,
 	SIP_HDR_TO,
 	SIP_HDR_CONTACT,
-	SIP_HDR_VIA,
+	SIP_HDR_VIA_UDP,
+	SIP_HDR_VIA_TCP,
 	SIP_HDR_EXPIRES,
 	SIP_HDR_CONTENT_LENGTH,
 };
diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index 2454ea5..b232e40 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -122,7 +122,7 @@ static unsigned int ip_nat_sip(struct sk_buff *skb, unsigned int dataoff,
 
 	/* Translate topmost Via header and parameters */
 	if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
-				    SIP_HDR_VIA, NULL, &matchoff, &matchlen,
+				    SIP_HDR_VIA_UDP, NULL, &matchoff, &matchlen,
 				    &addr, &port) > 0) {
 		unsigned int matchend, poff, plen, buflen, n;
 		char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 0ec37d6..1cc75c5 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -16,6 +16,7 @@
 #include <linux/inet.h>
 #include <linux/in.h>
 #include <linux/udp.h>
+#include <linux/tcp.h>
 #include <linux/netfilter.h>
 
 #include <net/netfilter/nf_conntrack.h>
@@ -287,7 +288,8 @@ static const struct sip_header ct_sip_hdrs[] = {
 	[SIP_HDR_FROM]			= SIP_HDR("From", "f", "sip:", skp_epaddr_len),
 	[SIP_HDR_TO]			= SIP_HDR("To", "t", "sip:", skp_epaddr_len),
 	[SIP_HDR_CONTACT]		= SIP_HDR("Contact", "m", "sip:", skp_epaddr_len),
-	[SIP_HDR_VIA]			= SIP_HDR("Via", "v", "UDP ", epaddr_len),
+	[SIP_HDR_VIA_UDP]		= SIP_HDR("Via", "v", "UDP ", epaddr_len),
+	[SIP_HDR_VIA_TCP]		= SIP_HDR("Via", "v", "TCP ", epaddr_len),
 	[SIP_HDR_EXPIRES]		= SIP_HDR("Expires", NULL, NULL, digits_len),
 	[SIP_HDR_CONTENT_LENGTH]	= SIP_HDR("Content-Length", "l", NULL, digits_len),
 };
@@ -519,6 +521,33 @@ int ct_sip_parse_header_uri(const struct nf_conn *ct, const char *dptr,
 }
 EXPORT_SYMBOL_GPL(ct_sip_parse_header_uri);
 
+static int ct_sip_parse_param(const struct nf_conn *ct, const char *dptr,
+			      unsigned int dataoff, unsigned int datalen,
+			      const char *name,
+			      unsigned int *matchoff, unsigned int *matchlen)
+{
+	const char *limit = dptr + datalen;
+	const char *start;
+	const char *end;
+
+	limit = ct_sip_header_search(dptr + dataoff, limit, ",", strlen(","));
+	if (!limit)
+		limit = dptr + datalen;
+
+	start = ct_sip_header_search(dptr + dataoff, limit, name, strlen(name));
+	if (!start)
+		return 0;
+	start += strlen(name);
+
+	end = ct_sip_header_search(start, limit, ";", strlen(";"));
+	if (!end)
+		end = limit;
+
+	*matchoff = start - dptr;
+	*matchlen = end - start;
+	return 1;
+}
+
 /* Parse address from header parameter and return address, offset and length */
 int ct_sip_parse_address_param(const struct nf_conn *ct, const char *dptr,
 			       unsigned int dataoff, unsigned int datalen,
@@ -577,6 +606,29 @@ int ct_sip_parse_numerical_param(const struct nf_conn *ct, const char *dptr,
 }
 EXPORT_SYMBOL_GPL(ct_sip_parse_numerical_param);
 
+static int ct_sip_parse_transport(struct nf_conn *ct, const char *dptr,
+				  unsigned int dataoff, unsigned int datalen,
+				  u8 *proto)
+{
+	unsigned int matchoff, matchlen;
+
+	if (ct_sip_parse_param(ct, dptr, dataoff, datalen, "transport=",
+			       &matchoff, &matchlen)) {
+		if (!strnicmp(dptr + matchoff, "TCP", strlen("TCP")))
+			*proto = IPPROTO_TCP;
+		else if (!strnicmp(dptr + matchoff, "UDP", strlen("UDP")))
+			*proto = IPPROTO_UDP;
+		else
+			return 0;
+
+		if (*proto != nf_ct_protonum(ct))
+			return 0;
+	} else
+		*proto = nf_ct_protonum(ct);
+
+	return 1;
+}
+
 /* SDP header parsing: a SDP session description contains an ordered set of
  * headers, starting with a section containing general session parameters,
  * optionally followed by multiple media descriptions.
@@ -685,7 +737,7 @@ static int ct_sip_parse_sdp_addr(const struct nf_conn *ct, const char *dptr,
 
 static int refresh_signalling_expectation(struct nf_conn *ct,
 					  union nf_inet_addr *addr,
-					  __be16 port,
+					  u8 proto, __be16 port,
 					  unsigned int expires)
 {
 	struct nf_conn_help *help = nfct_help(ct);
@@ -697,6 +749,7 @@ static int refresh_signalling_expectation(struct nf_conn *ct,
 	hlist_for_each_entry_safe(exp, n, next, &help->expectations, lnode) {
 		if (exp->class != SIP_EXPECT_SIGNALLING ||
 		    !nf_inet_addr_cmp(&exp->tuple.dst.u3, addr) ||
+		    exp->tuple.dst.protonum != proto ||
 		    exp->tuple.dst.u.udp.port != port)
 			continue;
 		if (!del_timer(&exp->timeout))
@@ -1048,6 +1101,7 @@ static int process_register_request(struct sk_buff *skb, unsigned int dataoff,
 	struct nf_conntrack_expect *exp;
 	union nf_inet_addr *saddr, daddr;
 	__be16 port;
+	u8 proto;
 	unsigned int expires = 0;
 	int ret;
 	typeof(nf_nat_sip_expect_hook) nf_nat_sip_expect;
@@ -1080,6 +1134,10 @@ static int process_register_request(struct sk_buff *skb, unsigned int dataoff,
 	if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, &daddr))
 		return NF_ACCEPT;
 
+	if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen, *datalen,
+				   &proto) == 0)
+		return NF_ACCEPT;
+
 	if (ct_sip_parse_numerical_param(ct, *dptr,
 					 matchoff + matchlen, *datalen,
 					 "expires=", NULL, NULL, &expires) < 0)
@@ -1099,7 +1157,7 @@ static int process_register_request(struct sk_buff *skb, unsigned int dataoff,
 		saddr = &ct->tuplehash[!dir].tuple.src.u3;
 
 	nf_ct_expect_init(exp, SIP_EXPECT_SIGNALLING, nf_ct_l3num(ct),
-			  saddr, &daddr, IPPROTO_UDP, NULL, &port);
+			  saddr, &daddr, proto, NULL, &port);
 	exp->timeout.expires = sip_timeout * HZ;
 	exp->helper = nfct_help(ct)->helper;
 	exp->flags = NF_CT_EXPECT_PERMANENT | NF_CT_EXPECT_INACTIVE;
@@ -1132,6 +1190,7 @@ static int process_register_response(struct sk_buff *skb, unsigned int dataoff,
 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 	union nf_inet_addr addr;
 	__be16 port;
+	u8 proto;
 	unsigned int matchoff, matchlen, coff = 0;
 	unsigned int expires = 0;
 	int in_contact = 0, ret;
@@ -1172,6 +1231,10 @@ static int process_register_response(struct sk_buff *skb, unsigned int dataoff,
 		if (!nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, &addr))
 			continue;
 
+		if (ct_sip_parse_transport(ct, *dptr, matchoff + matchlen,
+					   *datalen, &proto) == 0)
+			continue;
+
 		ret = ct_sip_parse_numerical_param(ct, *dptr,
 						   matchoff + matchlen,
 						   *datalen, "expires=",
@@ -1180,7 +1243,8 @@ static int process_register_response(struct sk_buff *skb, unsigned int dataoff,
 			return NF_DROP;
 		if (c_expires == 0)
 			break;
-		if (refresh_signalling_expectation(ct, &addr, port, c_expires))
+		if (refresh_signalling_expectation(ct, &addr, proto, port,
+						   c_expires))
 			return NF_ACCEPT;
 	}
 
@@ -1265,50 +1329,123 @@ static int process_sip_request(struct sk_buff *skb, unsigned int dataoff,
 	return NF_ACCEPT;
 }
 
-static int sip_help(struct sk_buff *skb,
-		    unsigned int protoff,
-		    struct nf_conn *ct,
-		    enum ip_conntrack_info ctinfo)
+static int process_sip_msg(struct sk_buff *skb, struct nf_conn *ct,
+			   unsigned int dataoff, const char **dptr,
+			   unsigned int *datalen)
+{
+	typeof(nf_nat_sip_hook) nf_nat_sip;
+	int ret;
+
+	if (strnicmp(*dptr, "SIP/2.0 ", strlen("SIP/2.0 ")) != 0)
+		ret = process_sip_request(skb, dataoff, dptr, datalen);
+	else
+		ret = process_sip_response(skb, dataoff, dptr, datalen);
+
+	if (ret == NF_ACCEPT && 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;
+	}
+
+	return ret;
+}
+
+static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff,
+			struct nf_conn *ct, enum ip_conntrack_info ctinfo)
 {
+	struct tcphdr *th, _tcph;
 	unsigned int dataoff, datalen;
-	const char *dptr;
+	unsigned int matchoff, matchlen, clen;
+	unsigned int msglen, origlen;
+	const char *dptr, *end;
+	s16 diff, tdiff = 0;
 	int ret;
-	typeof(nf_nat_sip_hook) nf_nat_sip;
+
+	if (ctinfo != IP_CT_ESTABLISHED &&
+	    ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY)
+		return NF_ACCEPT;
 
 	/* No Data ? */
-	dataoff = protoff + sizeof(struct udphdr);
+	th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
+	if (th == NULL)
+		return NF_ACCEPT;
+	dataoff = protoff + th->doff * 4;
 	if (dataoff >= skb->len)
 		return NF_ACCEPT;
 
 	nf_ct_refresh(ct, skb, sip_timeout * HZ);
 
-	if (!skb_is_nonlinear(skb))
-		dptr = skb->data + dataoff;
-	else {
+	if (skb_is_nonlinear(skb)) {
 		pr_debug("Copy of skbuff not supported yet.\n");
 		return NF_ACCEPT;
 	}
 
+	dptr = skb->data + dataoff;
 	datalen = skb->len - dataoff;
 	if (datalen < strlen("SIP/2.0 200"))
 		return NF_ACCEPT;
 
-	if (strnicmp(dptr, "SIP/2.0 ", strlen("SIP/2.0 ")) != 0)
-		ret = process_sip_request(skb, dataoff, &dptr, &datalen);
-	else
-		ret = process_sip_response(skb, dataoff, &dptr, &datalen);
+	while (1) {
+		if (ct_sip_get_header(ct, dptr, 0, datalen,
+				      SIP_HDR_CONTENT_LENGTH,
+				      &matchoff, &matchlen) <= 0)
+			break;
 
-	if (ret == NF_ACCEPT && 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;
+		clen = simple_strtoul(dptr + matchoff, (char **)&end, 10);
+		if (dptr + matchoff == end)
+			break;
+
+		if (end + strlen("\r\n\r\n") > dptr + datalen)
+			break;
+		if (end[0] != '\r' || end[1] != '\n' ||
+		    end[2] != '\r' || end[3] != '\n')
+			break;
+		end += strlen("\r\n\r\n") + clen;
+
+		msglen = origlen = end - dptr;
+
+		ret = process_sip_msg(skb, ct, dataoff, &dptr, &msglen);
+		if (ret != NF_ACCEPT)
+			break;
+		diff     = msglen - origlen;
+		tdiff   += diff;
+
+		dataoff += msglen;
+		dptr    += msglen;
+		datalen  = datalen + diff - msglen;
 	}
 
 	return ret;
 }
 
-static struct nf_conntrack_helper sip[MAX_PORTS][2] __read_mostly;
-static char sip_names[MAX_PORTS][2][sizeof("sip-65535")] __read_mostly;
+static int sip_help_udp(struct sk_buff *skb, unsigned int protoff,
+			struct nf_conn *ct, enum ip_conntrack_info ctinfo)
+{
+	unsigned int dataoff, datalen;
+	const char *dptr;
+
+	/* No Data ? */
+	dataoff = protoff + sizeof(struct udphdr);
+	if (dataoff >= skb->len)
+		return NF_ACCEPT;
+
+	nf_ct_refresh(ct, skb, sip_timeout * HZ);
+
+	if (skb_is_nonlinear(skb)) {
+		pr_debug("Copy of skbuff not supported yet.\n");
+		return NF_ACCEPT;
+	}
+
+	dptr = skb->data + dataoff;
+	datalen = skb->len - dataoff;
+	if (datalen < strlen("SIP/2.0 200"))
+		return NF_ACCEPT;
+
+	return process_sip_msg(skb, ct, dataoff, &dptr, &datalen);
+}
+
+static struct nf_conntrack_helper sip[MAX_PORTS][4] __read_mostly;
+static char sip_names[MAX_PORTS][4][sizeof("sip-65535")] __read_mostly;
 
 static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = {
 	[SIP_EXPECT_SIGNALLING] = {
@@ -1333,7 +1470,7 @@ static void nf_conntrack_sip_fini(void)
 	int i, j;
 
 	for (i = 0; i < ports_c; i++) {
-		for (j = 0; j < 2; j++) {
+		for (j = 0; j < ARRAY_SIZE(sip[i]); j++) {
 			if (sip[i][j].me == NULL)
 				continue;
 			nf_conntrack_helper_unregister(&sip[i][j]);
@@ -1353,14 +1490,24 @@ static int __init nf_conntrack_sip_init(void)
 		memset(&sip[i], 0, sizeof(sip[i]));
 
 		sip[i][0].tuple.src.l3num = AF_INET;
-		sip[i][1].tuple.src.l3num = AF_INET6;
-		for (j = 0; j < 2; j++) {
-			sip[i][j].tuple.dst.protonum = IPPROTO_UDP;
+		sip[i][0].tuple.dst.protonum = IPPROTO_UDP;
+		sip[i][0].help = sip_help_udp;
+		sip[i][1].tuple.src.l3num = AF_INET;
+		sip[i][1].tuple.dst.protonum = IPPROTO_TCP;
+		sip[i][1].help = sip_help_tcp;
+
+		sip[i][2].tuple.src.l3num = AF_INET6;
+		sip[i][2].tuple.dst.protonum = IPPROTO_UDP;
+		sip[i][2].help = sip_help_udp;
+		sip[i][3].tuple.src.l3num = AF_INET6;
+		sip[i][3].tuple.dst.protonum = IPPROTO_TCP;
+		sip[i][3].help = sip_help_tcp;
+
+		for (j = 0; j < ARRAY_SIZE(sip[i]); j++) {
 			sip[i][j].tuple.src.u.udp.port = htons(ports[i]);
 			sip[i][j].expect_policy = sip_exp_policy;
 			sip[i][j].expect_class_max = SIP_EXPECT_MAX;
 			sip[i][j].me = THIS_MODULE;
-			sip[i][j].help = sip_help;
 
 			tmpname = &sip_names[i][j][0];
 			if (ports[i] == SIP_PORT)

Re: netfilter 05/08: nf_conntrack_sip: add TCP support

[Jan Engelhardt]

On Thursday 2010-02-11 08:39, Patrick McHardy wrote:

>    netfilter: nf_conntrack_sip: add TCP support
>    
>    Add TCP support, which is mandated by RFC3261 for all SIP elements.
>    
>    SIP over TCP is similar to UDP, except that messages are delimited
>    by Content-Length: headers and multiple messages may appear in one
>    packet.

Does it cope with TCP segmentation?

Re: netfilter 05/08: nf_conntrack_sip: add TCP support

[Patrick McHardy]

Jan Engelhardt wrote:
> On Thursday 2010-02-11 08:39, Patrick McHardy wrote:
> 
>>    netfilter: nf_conntrack_sip: add TCP support
>>    
>>    Add TCP support, which is mandated by RFC3261 for all SIP elements.
>>    
>>    SIP over TCP is similar to UDP, except that messages are delimited
>>    by Content-Length: headers and multiple messages may appear in one
>>    packet.
> 
> Does it cope with TCP segmentation?

No, messages split over multiple packets can't be handled, similar
to other helpers.

netfilter 06/08: nf_nat: support mangling a single TCP packet multiple times

[Patrick McHardy]

commit dd724e4ee502dc31747453025a8a113d3e2f1a62
Author: Patrick McHardy <kaber@trash.net>
Date:   Thu Feb 11 07:40:33 2010 +0100

    netfilter: nf_nat: support mangling a single TCP packet multiple times
    
    nf_nat_mangle_tcp_packet() can currently only handle a single mangling
    per window because it only maintains two sequence adjustment positions:
    the one before the last adjustment and the one after.
    
    This patch makes sequence number adjustment tracking in
    nf_nat_mangle_tcp_packet() optional and allows a helper to manually
    update the offsets after the packet has been fully handled.
    
    Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/include/net/netfilter/nf_nat_helper.h b/include/net/netfilter/nf_nat_helper.h
index 4222220..02bb6c2 100644
--- a/include/net/netfilter/nf_nat_helper.h
+++ b/include/net/netfilter/nf_nat_helper.h
@@ -7,13 +7,27 @@
 struct sk_buff;
 
 /* These return true or false. */
-extern int nf_nat_mangle_tcp_packet(struct sk_buff *skb,
-				    struct nf_conn *ct,
-				    enum ip_conntrack_info ctinfo,
-				    unsigned int match_offset,
-				    unsigned int match_len,
-				    const char *rep_buffer,
-				    unsigned int rep_len);
+extern int __nf_nat_mangle_tcp_packet(struct sk_buff *skb,
+				      struct nf_conn *ct,
+				      enum ip_conntrack_info ctinfo,
+				      unsigned int match_offset,
+				      unsigned int match_len,
+				      const char *rep_buffer,
+				      unsigned int rep_len, bool adjust);
+
+static inline int nf_nat_mangle_tcp_packet(struct sk_buff *skb,
+					   struct nf_conn *ct,
+					   enum ip_conntrack_info ctinfo,
+					   unsigned int match_offset,
+					   unsigned int match_len,
+					   const char *rep_buffer,
+					   unsigned int rep_len)
+{
+	return __nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
+					  match_offset, match_len,
+					  rep_buffer, rep_len, true);
+}
+
 extern int nf_nat_mangle_udp_packet(struct sk_buff *skb,
 				    struct nf_conn *ct,
 				    enum ip_conntrack_info ctinfo,
@@ -21,6 +35,10 @@ extern int nf_nat_mangle_udp_packet(struct sk_buff *skb,
 				    unsigned int match_len,
 				    const char *rep_buffer,
 				    unsigned int rep_len);
+
+extern void nf_nat_set_seq_adjust(struct nf_conn *ct,
+				  enum ip_conntrack_info ctinfo,
+				  __be32 seq, s16 off);
 extern int nf_nat_seq_adjust(struct sk_buff *skb,
 			     struct nf_conn *ct,
 			     enum ip_conntrack_info ctinfo);
diff --git a/net/ipv4/netfilter/nf_nat_helper.c b/net/ipv4/netfilter/nf_nat_helper.c
index 7f10a6b..4b6af4b 100644
--- a/net/ipv4/netfilter/nf_nat_helper.c
+++ b/net/ipv4/netfilter/nf_nat_helper.c
@@ -141,6 +141,17 @@ static int enlarge_skb(struct sk_buff *skb, unsigned int extra)
 	return 1;
 }
 
+void nf_nat_set_seq_adjust(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
+			   __be32 seq, s16 off)
+{
+	if (!off)
+		return;
+	set_bit(IPS_SEQ_ADJUST_BIT, &ct->status);
+	adjust_tcp_sequence(ntohl(seq), off, ct, ctinfo);
+	nf_conntrack_event_cache(IPCT_NATSEQADJ, ct);
+}
+EXPORT_SYMBOL_GPL(nf_nat_set_seq_adjust);
+
 /* Generic function for mangling variable-length address changes inside
  * NATed TCP connections (like the PORT XXX,XXX,XXX,XXX,XXX,XXX
  * command in FTP).
@@ -149,14 +160,13 @@ static int enlarge_skb(struct sk_buff *skb, unsigned int extra)
  * skb enlargement, ...
  *
  * */
-int
-nf_nat_mangle_tcp_packet(struct sk_buff *skb,
-			 struct nf_conn *ct,
-			 enum ip_conntrack_info ctinfo,
-			 unsigned int match_offset,
-			 unsigned int match_len,
-			 const char *rep_buffer,
-			 unsigned int rep_len)
+int __nf_nat_mangle_tcp_packet(struct sk_buff *skb,
+			       struct nf_conn *ct,
+			       enum ip_conntrack_info ctinfo,
+			       unsigned int match_offset,
+			       unsigned int match_len,
+			       const char *rep_buffer,
+			       unsigned int rep_len, bool adjust)
 {
 	struct rtable *rt = skb_rtable(skb);
 	struct iphdr *iph;
@@ -202,16 +212,13 @@ nf_nat_mangle_tcp_packet(struct sk_buff *skb,
 		inet_proto_csum_replace2(&tcph->check, skb,
 					 htons(oldlen), htons(datalen), 1);
 
-	if (rep_len != match_len) {
-		set_bit(IPS_SEQ_ADJUST_BIT, &ct->status);
-		adjust_tcp_sequence(ntohl(tcph->seq),
-				    (int)rep_len - (int)match_len,
-				    ct, ctinfo);
-		nf_conntrack_event_cache(IPCT_NATSEQADJ, ct);
-	}
+	if (adjust && rep_len != match_len)
+		nf_nat_set_seq_adjust(ct, ctinfo, tcph->seq,
+				      (int)rep_len - (int)match_len);
+
 	return 1;
 }
-EXPORT_SYMBOL(nf_nat_mangle_tcp_packet);
+EXPORT_SYMBOL(__nf_nat_mangle_tcp_packet);
 
 /* Generic function for mangling variable-length address changes inside
  * NATed UDP connections (like the CONNECT DATA XXXXX MESG XXXXX INDEX XXXXX

netfilter 07/08: nf_nat_sip: add TCP support

[Patrick McHardy]

commit ed23b7593761f4d57be5906ada862d1b74137af8
Author: Patrick McHardy <kaber@trash.net>
Date:   Thu Feb 11 07:40:34 2010 +0100

    netfilter: nf_nat_sip: add TCP support
    
    Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h
index fa9bb89..cd84d6f 100644
--- a/include/linux/netfilter/nf_conntrack_sip.h
+++ b/include/linux/netfilter/nf_conntrack_sip.h
@@ -104,6 +104,7 @@ extern unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb,
 				       unsigned int dataoff,
 				       const char **dptr,
 				       unsigned int *datalen);
+extern void (*nf_nat_sip_seq_adjust_hook)(struct sk_buff *skb, s16 off);
 extern unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb,
 					      unsigned int dataoff,
 					      const char **dptr,
diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index b232e40..39b1ac0 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -1,4 +1,4 @@
-/* SIP extension for UDP NAT alteration.
+/* SIP extension for NAT alteration.
  *
  * (C) 2005 by Christian Hentschel <chentschel@arnet.com.ar>
  * based on RR's ip_nat_ftp.c and other modules.
@@ -15,6 +15,7 @@
 #include <linux/ip.h>
 #include <net/ip.h>
 #include <linux/udp.h>
+#include <linux/tcp.h>
 
 #include <net/netfilter/nf_nat.h>
 #include <net/netfilter/nf_nat_helper.h>
@@ -36,10 +37,27 @@ static unsigned int mangle_packet(struct sk_buff *skb, unsigned int dataoff,
 {
 	enum ip_conntrack_info ctinfo;
 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
-
-	if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, matchoff, matchlen,
-				      buffer, buflen))
-		return 0;
+	struct tcphdr *th;
+	unsigned int baseoff;
+
+	if (nf_ct_protonum(ct) == IPPROTO_TCP) {
+		th = (struct tcphdr *)(skb->data + ip_hdrlen(skb));
+		baseoff = ip_hdrlen(skb) + th->doff * 4;
+		matchoff += dataoff - baseoff;
+
+		if (!__nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
+						matchoff, matchlen,
+						buffer, buflen, false))
+			return 0;
+	} else {
+		baseoff = ip_hdrlen(skb) + sizeof(struct udphdr);
+		matchoff += dataoff - baseoff;
+
+		if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo,
+					      matchoff, matchlen,
+					      buffer, buflen))
+			return 0;
+	}
 
 	/* Reload data pointer and adjust datalen value */
 	*dptr = skb->data + dataoff;
@@ -104,6 +122,7 @@ static unsigned int ip_nat_sip(struct sk_buff *skb, unsigned int dataoff,
 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 	unsigned int coff, matchoff, matchlen;
+	enum sip_header_types hdr;
 	union nf_inet_addr addr;
 	__be16 port;
 	int request, in_header;
@@ -120,9 +139,14 @@ static unsigned int ip_nat_sip(struct sk_buff *skb, unsigned int dataoff,
 	} else
 		request = 0;
 
+	if (nf_ct_protonum(ct) == IPPROTO_TCP)
+		hdr = SIP_HDR_VIA_TCP;
+	else
+		hdr = SIP_HDR_VIA_UDP;
+
 	/* Translate topmost Via header and parameters */
 	if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
-				    SIP_HDR_VIA_UDP, NULL, &matchoff, &matchlen,
+				    hdr, NULL, &matchoff, &matchlen,
 				    &addr, &port) > 0) {
 		unsigned int matchend, poff, plen, buflen, n;
 		char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
@@ -204,9 +228,23 @@ next:
 	if (!map_sip_addr(skb, dataoff, dptr, datalen, SIP_HDR_FROM) ||
 	    !map_sip_addr(skb, dataoff, dptr, datalen, SIP_HDR_TO))
 		return NF_DROP;
+
 	return NF_ACCEPT;
 }
 
+static void ip_nat_sip_seq_adjust(struct sk_buff *skb, s16 off)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+	const struct tcphdr *th;
+
+	if (nf_ct_protonum(ct) != IPPROTO_TCP || off == 0)
+		return;
+
+	th = (struct tcphdr *)(skb->data + ip_hdrlen(skb));
+	nf_nat_set_seq_adjust(ct, ctinfo, th->seq, off);
+}
+
 /* Handles expected signalling connections and media streams */
 static void ip_nat_sip_expected(struct nf_conn *ct,
 				struct nf_conntrack_expect *exp)
@@ -277,8 +315,8 @@ static unsigned int ip_nat_sip_expect(struct sk_buff *skb, unsigned int dataoff,
 	if (port == 0)
 		return NF_DROP;
 
-	if (exp->tuple.dst.u3.ip != exp->saved_ip ||
-	    exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port) {
+	if (0 && (exp->tuple.dst.u3.ip != exp->saved_ip ||
+	    exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port)) {
 		buflen = sprintf(buffer, "%pI4:%u", &newip, port);
 		if (!mangle_packet(skb, dataoff, dptr, datalen,
 				   matchoff, matchlen, buffer, buflen))
@@ -472,6 +510,7 @@ err1:
 static void __exit nf_nat_sip_fini(void)
 {
 	rcu_assign_pointer(nf_nat_sip_hook, NULL);
+	rcu_assign_pointer(nf_nat_sip_seq_adjust_hook, NULL);
 	rcu_assign_pointer(nf_nat_sip_expect_hook, NULL);
 	rcu_assign_pointer(nf_nat_sdp_addr_hook, NULL);
 	rcu_assign_pointer(nf_nat_sdp_port_hook, NULL);
@@ -483,12 +522,14 @@ static void __exit nf_nat_sip_fini(void)
 static int __init nf_nat_sip_init(void)
 {
 	BUG_ON(nf_nat_sip_hook != NULL);
+	BUG_ON(nf_nat_sip_seq_adjust_hook != NULL);
 	BUG_ON(nf_nat_sip_expect_hook != NULL);
 	BUG_ON(nf_nat_sdp_addr_hook != NULL);
 	BUG_ON(nf_nat_sdp_port_hook != NULL);
 	BUG_ON(nf_nat_sdp_session_hook != NULL);
 	BUG_ON(nf_nat_sdp_media_hook != NULL);
 	rcu_assign_pointer(nf_nat_sip_hook, ip_nat_sip);
+	rcu_assign_pointer(nf_nat_sip_seq_adjust_hook, ip_nat_sip_seq_adjust);
 	rcu_assign_pointer(nf_nat_sip_expect_hook, ip_nat_sip_expect);
 	rcu_assign_pointer(nf_nat_sdp_addr_hook, ip_nat_sdp_addr);
 	rcu_assign_pointer(nf_nat_sdp_port_hook, ip_nat_sdp_port);
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 1cc75c5..3bb3aaf 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -56,6 +56,9 @@ unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb, unsigned int dataoff,
 				unsigned int *datalen) __read_mostly;
 EXPORT_SYMBOL_GPL(nf_nat_sip_hook);
 
+void (*nf_nat_sip_seq_adjust_hook)(struct sk_buff *skb, s16 off) __read_mostly;
+EXPORT_SYMBOL_GPL(nf_nat_sip_seq_adjust_hook);
+
 unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb,
 				       unsigned int dataoff,
 				       const char **dptr,
@@ -1360,6 +1363,7 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff,
 	const char *dptr, *end;
 	s16 diff, tdiff = 0;
 	int ret;
+	typeof(nf_nat_sip_seq_adjust_hook) nf_nat_sip_seq_adjust;
 
 	if (ctinfo != IP_CT_ESTABLISHED &&
 	    ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY)
@@ -1415,6 +1419,12 @@ 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) {
+		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);
+	}
+
 	return ret;
 }
 

netfilter 08/08: nf_conntrack_sip: add T.38 FAX support

[Patrick McHardy]

commit 9811ea1e1a05af3cde40d4dca040c03a0c10540e
Author: Patrick McHardy <kaber@trash.net>
Date:   Thu Feb 11 07:40:34 2010 +0100

    netfilter: nf_conntrack_sip: add T.38 FAX support
    
    Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h
index cd84d6f..ff8cfbc 100644
--- a/include/linux/netfilter/nf_conntrack_sip.h
+++ b/include/linux/netfilter/nf_conntrack_sip.h
@@ -14,6 +14,7 @@ enum sip_expectation_classes {
 	SIP_EXPECT_SIGNALLING,
 	SIP_EXPECT_AUDIO,
 	SIP_EXPECT_VIDEO,
+	SIP_EXPECT_IMAGE,
 	__SIP_EXPECT_MAX
 };
 #define SIP_EXPECT_MAX	(__SIP_EXPECT_MAX - 1)
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 5043d61..5b7d883 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -70,7 +70,7 @@ union nf_conntrack_help {
 struct nf_conntrack_helper;
 
 /* Must be kept in sync with the classes defined by helpers */
-#define NF_CT_MAX_EXPECT_CLASSES	3
+#define NF_CT_MAX_EXPECT_CLASSES	4
 
 /* nf_conn feature for connections that have a helper */
 struct nf_conn_help {
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 3bb3aaf..fbe8ff5 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -907,6 +907,7 @@ err1:
 static const struct sdp_media_type sdp_media_types[] = {
 	SDP_MEDIA_TYPE("audio ", SIP_EXPECT_AUDIO),
 	SDP_MEDIA_TYPE("video ", SIP_EXPECT_VIDEO),
+	SDP_MEDIA_TYPE("image ", SIP_EXPECT_IMAGE),
 };
 
 static const struct sdp_media_type *sdp_media_type(const char *dptr,
@@ -932,7 +933,6 @@ static int process_sdp(struct sk_buff *skb, unsigned int dataoff,
 {
 	enum ip_conntrack_info ctinfo;
 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
-	struct nf_conn_help *help = nfct_help(ct);
 	unsigned int matchoff, matchlen;
 	unsigned int mediaoff, medialen;
 	unsigned int sdpoff;
@@ -1024,9 +1024,6 @@ static int process_sdp(struct sk_buff *skb, unsigned int dataoff,
 		ret = nf_nat_sdp_session(skb, dataoff, dptr, datalen, sdpoff,
 					 &rtp_addr);
 
-	if (ret == NF_ACCEPT && i > 0)
-		help->help.ct_sip_info.invite_cseq = cseq;
-
 	return ret;
 }
 static int process_invite_response(struct sk_buff *skb, unsigned int dataoff,
@@ -1077,6 +1074,22 @@ static int process_prack_response(struct sk_buff *skb, unsigned int dataoff,
 	return NF_ACCEPT;
 }
 
+static int process_invite_request(struct sk_buff *skb, unsigned int dataoff,
+				  const char **dptr, unsigned int *datalen,
+				  unsigned int cseq)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+	struct nf_conn_help *help = nfct_help(ct);
+	unsigned int ret;
+
+	flush_expectations(ct, true);
+	ret = process_sdp(skb, dataoff, dptr, datalen, cseq);
+	if (ret == NF_ACCEPT)
+		help->help.ct_sip_info.invite_cseq = cseq;
+	return ret;
+}
+
 static int process_bye_request(struct sk_buff *skb, unsigned int dataoff,
 			       const char **dptr, unsigned int *datalen,
 			       unsigned int cseq)
@@ -1257,7 +1270,7 @@ flush:
 }
 
 static const struct sip_handler sip_handlers[] = {
-	SIP_HANDLER("INVITE", process_sdp, process_invite_response),
+	SIP_HANDLER("INVITE", process_invite_request, process_invite_response),
 	SIP_HANDLER("UPDATE", process_sdp, process_update_response),
 	SIP_HANDLER("ACK", process_sdp, NULL),
 	SIP_HANDLER("PRACK", process_sdp, process_prack_response),
@@ -1473,6 +1486,11 @@ static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1
 		.max_expected	= 2 * IP_CT_DIR_MAX,
 		.timeout	= 3 * 60,
 	},
+	[SIP_EXPECT_IMAGE] = {
+		.name		= "image",
+		.max_expected	= IP_CT_DIR_MAX,
+		.timeout	= 3 * 60,
+	},
 };
 
 static void nf_conntrack_sip_fini(void)