1 files changed, 59 insertions, 13 deletions

diff --git a/net/netfilter/nf_nat_sip.c b/net/netfilter/nf_nat_sip.c
index 16303c752213..96ccdf78a29f 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;
@@ -156,8 +159,10 @@ static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff,
 					 &matchoff, &matchlen,
 					 &addr, &port) > 0 &&
 		    !map_addr(skb, protoff, dataoff, dptr, datalen,
-			      matchoff, matchlen, &addr, port))
+			      matchoff, matchlen, &addr, port)) {
+			nf_ct_helper_log(skb, ct, "cannot mangle SIP message");
 			return NF_DROP;
+		}
 		request = 1;
 	} else
 		request = 0;
@@ -190,8 +195,10 @@ static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff,
 
 		olen = *datalen;
 		if (!map_addr(skb, protoff, dataoff, dptr, datalen,
-			      matchoff, matchlen, &addr, port))
+			      matchoff, matchlen, &addr, port)) {
+			nf_ct_helper_log(skb, ct, "cannot mangle Via header");
 			return NF_DROP;
+		}
 
 		matchend = matchoff + matchlen + *datalen - olen;
 
@@ -206,8 +213,10 @@ static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff,
 					&ct->tuplehash[!dir].tuple.dst.u3,
 					true);
 			if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
-					   poff, plen, buffer, buflen))
+					   poff, plen, buffer, buflen)) {
+				nf_ct_helper_log(skb, ct, "cannot mangle maddr");
 				return NF_DROP;
+			}
 		}
 
 		/* The received= parameter (RFC 2361) contains the address
@@ -222,6 +231,7 @@ static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff,
 					false);
 			if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
 					   poff, plen, buffer, buflen))
+				nf_ct_helper_log(skb, ct, "cannot mangle received");
 				return NF_DROP;
 		}
 
@@ -235,8 +245,10 @@ static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff,
 			__be16 p = ct->tuplehash[!dir].tuple.src.u.udp.port;
 			buflen = sprintf(buffer, "%u", ntohs(p));
 			if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
-					   poff, plen, buffer, buflen))
+					   poff, plen, buffer, buflen)) {
+				nf_ct_helper_log(skb, ct, "cannot mangle rport");
 				return NF_DROP;
+			}
 		}
 	}
 
@@ -250,13 +262,36 @@ next:
 				       &addr, &port) > 0) {
 		if (!map_addr(skb, protoff, dataoff, dptr, datalen,
 			      matchoff, matchlen,
-			      &addr, port))
+			      &addr, port)) {
+			nf_ct_helper_log(skb, ct, "cannot mangle contact");
 			return NF_DROP;
+		}
 	}
 
 	if (!map_sip_addr(skb, protoff, dataoff, dptr, datalen, SIP_HDR_FROM) ||
-	    !map_sip_addr(skb, protoff, dataoff, dptr, datalen, SIP_HDR_TO))
+	    !map_sip_addr(skb, protoff, dataoff, dptr, datalen, SIP_HDR_TO)) {
+		nf_ct_helper_log(skb, ct, "cannot mangle SIP from/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)) {
+			nf_ct_helper_log(skb, ct, "cannot mangle packet");
+			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)) {
+			nf_ct_helper_log(skb, ct, "cannot mangle packet");
+			return NF_DROP;
+		}
+	}
 
 	return NF_ACCEPT;
 }
@@ -311,8 +346,10 @@ 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 +363,9 @@ 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);
@@ -351,15 +389,19 @@ static unsigned int nf_nat_sip_expect(struct sk_buff *skb, unsigned int protoff,
 		}
 	}
 
-	if (port == 0)
+	if (port == 0) {
+		nf_ct_helper_log(skb, ct, "all ports in use for SIP");
 		return NF_DROP;
+	}
 
 	if (!nf_inet_addr_cmp(&exp->tuple.dst.u3, &exp->saved_addr) ||
 	    exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port) {
 		buflen = sip_sprintf_addr_port(ct, buffer, &newaddr, port);
 		if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
-				   matchoff, matchlen, buffer, buflen))
+				   matchoff, matchlen, buffer, buflen)) {
+			nf_ct_helper_log(skb, ct, "cannot mangle packet");
 			goto err;
+		}
 	}
 	return NF_ACCEPT;
 
@@ -552,14 +594,18 @@ static unsigned int nf_nat_sdp_media(struct sk_buff *skb, unsigned int protoff,
 		}
 	}
 
-	if (port == 0)
+	if (port == 0) {
+		nf_ct_helper_log(skb, ct, "all ports in use for SDP media");
 		goto err1;
+	}
 
 	/* Update media port. */
 	if (rtp_exp->tuple.dst.u.udp.port != rtp_exp->saved_proto.udp.port &&
 	    !nf_nat_sdp_port(skb, protoff, dataoff, dptr, datalen,
-			     mediaoff, medialen, port))
+			     mediaoff, medialen, port)) {
+		nf_ct_helper_log(skb, ct, "cannot mangle SDP message");
 		goto err2;
+	}
 
 	return NF_ACCEPT;