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-rw-r--r--include/linux/netfilter/nf_conntrack_sip.h3
-rw-r--r--net/netfilter/nf_conntrack_sip.c17
-rw-r--r--net/netfilter/nf_nat_sip.c27
3 files changed, 44 insertions, 3 deletions
diff --git a/include/linux/netfilter/nf_conntrack_sip.h b/include/linux/netfilter/nf_conntrack_sip.h
index 387bdd02945d..ba7f571a2b1c 100644
--- a/include/linux/netfilter/nf_conntrack_sip.h
+++ b/include/linux/netfilter/nf_conntrack_sip.h
@@ -4,12 +4,15 @@
#include <net/netfilter/nf_conntrack_expect.h>
+#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 {
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index df8f4f284481..72a67bbe3518 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -1440,8 +1440,25 @@ static int process_sip_request(struct sk_buff *skb, unsigned int protoff,
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(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))
+ ct_sip_info->forced_dport = port;
for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) {
const struct sip_handler *handler;
diff --git a/net/netfilter/nf_nat_sip.c b/net/netfilter/nf_nat_sip.c
index 16303c752213..5951146e7688 100644
--- a/net/netfilter/nf_nat_sip.c
+++ b/net/netfilter/nf_nat_sip.c
@@ -95,6 +95,7 @@ static int map_addr(struct sk_buff *skb, unsigned int protoff,
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
char buffer[INET6_ADDRSTRLEN + sizeof("[]:nnnnn")];
unsigned int buflen;
union nf_inet_addr newaddr;
@@ -107,7 +108,8 @@ static int map_addr(struct sk_buff *skb, unsigned int protoff,
} else if (nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, addr) &&
ct->tuplehash[dir].tuple.dst.u.udp.port == port) {
newaddr = ct->tuplehash[!dir].tuple.src.u3;
- newport = ct->tuplehash[!dir].tuple.src.u.udp.port;
+ newport = ct_sip_info->forced_dport ? :
+ ct->tuplehash[!dir].tuple.src.u.udp.port;
} else
return 1;
@@ -144,6 +146,7 @@ static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff,
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
unsigned int coff, matchoff, matchlen;
enum sip_header_types hdr;
union nf_inet_addr addr;
@@ -258,6 +261,21 @@ next:
!map_sip_addr(skb, protoff, 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 && ct_sip_info->forced_dport) {
+ struct udphdr *uh;
+
+ if (!skb_make_writable(skb, skb->len))
+ return NF_DROP;
+
+ uh = (void *)skb->data + protoff;
+ uh->dest = ct_sip_info->forced_dport;
+
+ if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, protoff,
+ 0, 0, NULL, 0))
+ return NF_DROP;
+ }
+
return NF_ACCEPT;
}
@@ -311,8 +329,10 @@ static unsigned int nf_nat_sip_expect(struct sk_buff *skb, unsigned int protoff,
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+ struct nf_ct_sip_master *ct_sip_info = nfct_help_data(ct);
union nf_inet_addr newaddr;
u_int16_t port;
+ __be16 srcport;
char buffer[INET6_ADDRSTRLEN + sizeof("[]:nnnnn")];
unsigned int buflen;
@@ -326,8 +346,9 @@ static unsigned int nf_nat_sip_expect(struct sk_buff *skb, unsigned int protoff,
/* 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 = 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);