[NETFILTER]: nf_nat_sip: translate all Via headers

Update maddr=, received= and rport= Via-header parameters refering to
the signalling connection.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 73 insertions, 1 deletions

diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index b44281011d6d..71a4adcfd576 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -100,9 +100,11 @@ static unsigned int ip_nat_sip(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);
         unsigned int matchoff, matchlen;
         union nf_inet_addr addr;
         __be16 port;
+        int request;
 
         /* Basic rules: requests and responses. */
         if (strnicmp(*dptr, "SIP/2.0", strlen("SIP/2.0")) != 0) {
@@ -112,11 +114,81 @@ static unsigned int ip_nat_sip(struct sk_buff *skb,
                     !map_addr(skb, dptr, datalen, matchoff, matchlen,
                               &addr, port))
                         return NF_DROP;
+                request = 1;
+        } else
+                request = 0;
+
+        /* Translate topmost Via header and parameters */
+        if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
+                                    SIP_HDR_VIA, NULL, &matchoff, &matchlen,
+                                    &addr, &port) > 0) {
+                unsigned int matchend, poff, plen, buflen, n;
+                char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
+
+                /* We're only interested in headers related to this
+                 * connection */
+                if (request) {
+                        if (addr.ip != ct->tuplehash[dir].tuple.src.u3.ip ||
+                            port != ct->tuplehash[dir].tuple.src.u.udp.port)
+                                goto next;
+                } else {
+                        if (addr.ip != ct->tuplehash[dir].tuple.dst.u3.ip ||
+                            port != ct->tuplehash[dir].tuple.dst.u.udp.port)
+                                goto next;
+                }
+
+                if (!map_addr(skb, dptr, datalen, matchoff, matchlen,
+                              &addr, port))
+                        return NF_DROP;
+
+                matchend = matchoff + matchlen;
+
+                /* The maddr= parameter (RFC 2361) specifies where to send
+                 * the reply. */
+                if (ct_sip_parse_address_param(ct, *dptr, matchend, *datalen,
+                                               "maddr=", &poff, &plen,
+                                               &addr) > 0 &&
+                    addr.ip == ct->tuplehash[dir].tuple.src.u3.ip &&
+                    addr.ip != ct->tuplehash[!dir].tuple.dst.u3.ip) {
+                        __be32 ip = ct->tuplehash[!dir].tuple.dst.u3.ip;
+                        buflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(ip));
+                        if (!mangle_packet(skb, dptr, datalen, poff, plen,
+                                           buffer, buflen))
+                                return NF_DROP;
+                }
+
+                /* The received= parameter (RFC 2361) contains the address
+                 * from which the server received the request. */
+                if (ct_sip_parse_address_param(ct, *dptr, matchend, *datalen,
+                                               "received=", &poff, &plen,
+                                               &addr) > 0 &&
+                    addr.ip == ct->tuplehash[dir].tuple.dst.u3.ip &&
+                    addr.ip != ct->tuplehash[!dir].tuple.src.u3.ip) {
+                        __be32 ip = ct->tuplehash[!dir].tuple.src.u3.ip;
+                        buflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(ip));
+                        if (!mangle_packet(skb, dptr, datalen, poff, plen,
+                                           buffer, buflen))
+                                return NF_DROP;
+                }
+
+                /* The rport= parameter (RFC 3581) contains the port number
+                 * from which the server received the request. */
+                if (ct_sip_parse_numerical_param(ct, *dptr, matchend, *datalen,
+                                                 "rport=", &poff, &plen,
+                                                 &n) > 0 &&
+                    htons(n) == ct->tuplehash[dir].tuple.dst.u.udp.port &&
+                    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))
+                                return NF_DROP;
+                }
         }
 
+next:
         if (!map_sip_addr(skb, dptr, datalen, SIP_HDR_FROM) ||
             !map_sip_addr(skb, dptr, datalen, SIP_HDR_TO) ||
-            !map_sip_addr(skb, dptr, datalen, SIP_HDR_VIA) ||
             !map_sip_addr(skb, dptr, datalen, SIP_HDR_CONTACT))
                 return NF_DROP;
         return NF_ACCEPT;