1 files changed, 25 insertions, 13 deletions

diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index 4334d5cabc5b..14544320c545 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -318,11 +318,11 @@ static int mangle_content_len(struct sk_buff *skb,
                              buffer, buflen);
 }
 
-static unsigned mangle_sdp_packet(struct sk_buff *skb, const char **dptr,
-                                  unsigned int dataoff, unsigned int *datalen,
-                                  enum sdp_header_types type,
-                                  enum sdp_header_types term,
-                                  char *buffer, int buflen)
+static int mangle_sdp_packet(struct sk_buff *skb, const char **dptr,
+                             unsigned int dataoff, unsigned int *datalen,
+                             enum sdp_header_types type,
+                             enum sdp_header_types term,
+                             char *buffer, int buflen)
 {
         enum ip_conntrack_info ctinfo;
         struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
@@ -330,9 +330,9 @@ static unsigned mangle_sdp_packet(struct sk_buff *skb, const char **dptr,
 
         if (ct_sip_get_sdp_header(ct, *dptr, dataoff, *datalen, type, term,
                                   &matchoff, &matchlen) <= 0)
-                return 0;
+                return -ENOENT;
         return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
-                             buffer, buflen);
+                             buffer, buflen) ? 0 : -EINVAL;
 }
 
 static unsigned int ip_nat_sdp_addr(struct sk_buff *skb, const char **dptr,
@@ -346,8 +346,8 @@ static unsigned int ip_nat_sdp_addr(struct sk_buff *skb, const char **dptr,
         unsigned int buflen;
 
         buflen = sprintf(buffer, NIPQUAD_FMT, NIPQUAD(addr->ip));
-        if (!mangle_sdp_packet(skb, dptr, dataoff, datalen, type, term,
-                               buffer, buflen))
+        if (mangle_sdp_packet(skb, dptr, dataoff, datalen, type, term,
+                              buffer, buflen))
                 return 0;
 
         return mangle_content_len(skb, dptr, datalen);
@@ -381,15 +381,27 @@ static unsigned int ip_nat_sdp_session(struct sk_buff *skb, const char **dptr,
 
         /* Mangle session description owner and contact addresses */
         buflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(addr->ip));
-        if (!mangle_sdp_packet(skb, dptr, dataoff, datalen,
+        if (mangle_sdp_packet(skb, dptr, dataoff, datalen,
                                SDP_HDR_OWNER_IP4, SDP_HDR_MEDIA,
                                buffer, buflen))
                 return 0;
 
-        if (!mangle_sdp_packet(skb, dptr, dataoff, datalen,
-                               SDP_HDR_CONNECTION_IP4, SDP_HDR_MEDIA,
-                               buffer, buflen))
+        switch (mangle_sdp_packet(skb, dptr, dataoff, datalen,
+                                  SDP_HDR_CONNECTION_IP4, SDP_HDR_MEDIA,
+                                  buffer, buflen)) {
+        case 0:
+        /*
+         * RFC 2327:
+         *
+         * Session description
+         *
+         * c=* (connection information - not required if included in all media)
+         */
+        case -ENOENT:
+                break;
+        default:
                 return 0;
+        }
 
         return mangle_content_len(skb, dptr, datalen);
 }