linux/generic: add 2.6.37 support for the Cisco 7941/7945 IP phones: http://lkml.org/lkml/2010/11/21/219 (thank you Kevin Cernekee)

SVN-Revision: 24114

target/linux/generic/patches-2.6.37/160-netfilter_cisco_794x_iphone.patch

@@ -0,0 +1,118 @@
+--- a/include/linux/netfilter/nf_conntrack_sip.h
++++ b/include/linux/netfilter/nf_conntrack_sip.h
+@@ -2,12 +2,15 @@
+ #define __NF_CONNTRACK_SIP_H__
+ #ifdef __KERNEL__
+ 
++#include <linux/types.h>
++
+ #define SIP_PORT	5060
+ #define SIP_TIMEOUT	3600
+ 
+ struct nf_ct_sip_master {
+ 	unsigned int	register_cseq;
+ 	unsigned int	invite_cseq;
++	__be16		forced_dport;
+ };
+ 
+ enum sip_expectation_classes {
+--- a/net/ipv4/netfilter/nf_nat_sip.c
++++ b/net/ipv4/netfilter/nf_nat_sip.c
+@@ -73,6 +73,7 @@ static int map_addr(struct sk_buff *skb,
+ 	enum ip_conntrack_info ctinfo;
+ 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+ 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
++	struct nf_conn_help *help = nfct_help(ct);
+ 	char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
+ 	unsigned int buflen;
+ 	__be32 newaddr;
+@@ -85,7 +86,8 @@ static int map_addr(struct sk_buff *skb,
+ 	} else if (ct->tuplehash[dir].tuple.dst.u3.ip == addr->ip &&
+ 		   ct->tuplehash[dir].tuple.dst.u.udp.port == port) {
+ 		newaddr = ct->tuplehash[!dir].tuple.src.u3.ip;
+-		newport = ct->tuplehash[!dir].tuple.src.u.udp.port;
++		newport = help->help.ct_sip_info.forced_dport ? :
++			  ct->tuplehash[!dir].tuple.src.u.udp.port;
+ 	} else
+ 		return 1;
+ 
+@@ -121,6 +123,7 @@ static unsigned int ip_nat_sip(struct sk
+ 	enum ip_conntrack_info ctinfo;
+ 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+ 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
++	struct nf_conn_help *help = nfct_help(ct);
+ 	unsigned int coff, matchoff, matchlen;
+ 	enum sip_header_types hdr;
+ 	union nf_inet_addr addr;
+@@ -229,6 +232,20 @@ next:
+ 	    !map_sip_addr(skb, dataoff, dptr, datalen, SIP_HDR_TO))
+ 		return NF_DROP;
+ 
++	/* Mangle destination port for Cisco phones, then fix up checksums */
++	if (dir == IP_CT_DIR_REPLY && help->help.ct_sip_info.forced_dport) {
++		struct udphdr *uh;
++
++		if (!skb_make_writable(skb, skb->len))
++			return NF_DROP;
++
++		uh = (struct udphdr *)(skb->data + ip_hdrlen(skb));
++		uh->dest = help->help.ct_sip_info.forced_dport;
++
++		if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, 0, 0, NULL, 0))
++			return NF_DROP;
++	}
++
+ 	return NF_ACCEPT;
+ }
+ 
+@@ -280,8 +297,10 @@ static unsigned int ip_nat_sip_expect(st
+ 	enum ip_conntrack_info ctinfo;
+ 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+ 	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
++	struct nf_conn_help *help = nfct_help(ct);
+ 	__be32 newip;
+ 	u_int16_t port;
++	__be16 srcport;
+ 	char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
+ 	unsigned buflen;
+ 
+@@ -294,8 +313,9 @@ static unsigned int ip_nat_sip_expect(st
+ 	/* If the signalling port matches the connection's source port in the
+ 	 * original direction, try to use the destination port in the opposite
+ 	 * direction. */
+-	if (exp->tuple.dst.u.udp.port ==
+-	    ct->tuplehash[dir].tuple.src.u.udp.port)
++	srcport = help->help.ct_sip_info.forced_dport ? :
++		  ct->tuplehash[dir].tuple.src.u.udp.port;
++	if (exp->tuple.dst.u.udp.port == srcport)
+ 		port = ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port);
+ 	else
+ 		port = ntohs(exp->tuple.dst.u.udp.port);
+--- a/net/netfilter/nf_conntrack_sip.c
++++ b/net/netfilter/nf_conntrack_sip.c
+@@ -1363,8 +1363,25 @@ static int process_sip_request(struct sk
+ {
+ 	enum ip_conntrack_info ctinfo;
+ 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
++	struct nf_conn_help *help = nfct_help(ct);
++	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+ 	unsigned int matchoff, matchlen;
+ 	unsigned int cseq, i;
++	union nf_inet_addr addr;
++	__be16 port;
++
++	/* Many Cisco IP phones use a high source port for SIP requests, but
++	 * listen for the response on port 5060.  If we are the local
++	 * router for one of these phones, save the port number from the
++	 * Via: header so that nf_nat_sip can redirect the responses to
++	 * the correct port.
++	 */
++	if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
++				    SIP_HDR_VIA_UDP, NULL, &matchoff,
++				    &matchlen, &addr, &port) > 0 &&
++	    port != ct->tuplehash[dir].tuple.src.u.udp.port &&
++	    nf_inet_addr_cmp(&addr, &ct->tuplehash[dir].tuple.src.u3))
++		help->help.ct_sip_info.forced_dport = port;
+ 
+ 	for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) {
+ 		const struct sip_handler *handler;