STUN: register a new conversation dissector after receiving a ConnectionBind Success Response message

According to RFC 6062, once the connection is established, data is sent as-is
To stop the STUN dissector from interfering, add the ability to specify a starting
frame for a conversation dissector and use it

Bug: 11641
Change-Id: I65ca96bddacf70444009c0642ea22173fa68992e
Reviewed-on: https://code.wireshark.org/review/11372
Petri-Dish: Pascal Quantin <pascal.quantin@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Pascal Quantin <pascal.quantin@gmail.com>

10 files changed, 44 insertions, 18 deletions

diff --git a/epan/conversation.c b/epan/conversation.c
index ab5cd5e312..f63007a12a 100644
--- a/epan/conversation.c
+++ b/epan/conversation.c
@@ -172,7 +172,7 @@ conversation_create_from_template(conversation_t *conversation, const address *a
 		 * Set the protocol dissector used for the template conversation as
 		 * the handler of the new conversation as well.
 		 */
-		new_conversation_from_template->dissector_handle = conversation->dissector_handle;
+		new_conversation_from_template->dissector_tree = conversation->dissector_tree;
 
 		return new_conversation_from_template;
 	}
@@ -712,8 +712,7 @@ conversation_new(const guint32 setup_frame, const address *addr1, const address
 	conversation->setup_frame = conversation->last_frame = setup_frame;
 	conversation->data_list = NULL;
 
-	/* clear dissector handle */
-	conversation->dissector_handle = NULL;
+	conversation->dissector_tree = wmem_tree_new(wmem_file_scope());
 
 	/* set the options and key pointer */
 	conversation->options = options;
@@ -1280,9 +1279,22 @@ conversation_delete_proto_data(conversation_t *conv, const int proto)
 }
 
 void
+conversation_set_dissector_from_frame_number(conversation_t *conversation,
+	const guint32 starting_frame_num, const dissector_handle_t handle)
+{
+	wmem_tree_insert32(conversation->dissector_tree, starting_frame_num, (void *)handle);
+}
+
+void
 conversation_set_dissector(conversation_t *conversation, const dissector_handle_t handle)
 {
-	conversation->dissector_handle = handle;
+	conversation_set_dissector_from_frame_number(conversation, 0, handle);
+}
+
+dissector_handle_t
+conversation_get_dissector(conversation_t *conversation, const guint32 frame_num)
+{
+	return (dissector_handle_t)wmem_tree_lookup32_le(conversation->dissector_tree, frame_num);
 }
 
 /*
@@ -1307,10 +1319,10 @@ try_conversation_dissector(const address *addr_a, const address *addr_b, const p
 
 	if (conversation != NULL) {
 		int ret;
-		if (conversation->dissector_handle == NULL)
+		dissector_handle_t handle = (dissector_handle_t)wmem_tree_lookup32_le(conversation->dissector_tree, pinfo->fd->num);
+		if (handle == NULL)
 			return FALSE;
-		ret=call_dissector_only(conversation->dissector_handle, tvb, pinfo,
-		    tree, data);
+		ret=call_dissector_only(handle, tvb, pinfo, tree, data);
 		if(!ret) {
 			/* this packet was rejected by the dissector
 			 * so return FALSE in case our caller wants
diff --git a/epan/conversation.h b/epan/conversation.h
index 3753c15b61..d796cde152 100644
--- a/epan/conversation.h
+++ b/epan/conversation.h
@@ -79,8 +79,8 @@ typedef struct conversation {
 	/* Assume that setup_frame is also the lowest frame number for now. */
 	guint32 last_frame;		/** highest frame number in this conversation */
 	GSList *data_list;			/** list of data associated with conversation */
-	dissector_handle_t dissector_handle;
-								/** handle for protocol dissector client associated with conversation */
+	wmem_tree_t *dissector_tree;
+								/** tree containing protocol dissector client associated with conversation */
 	guint	options;			/** wildcard flags */
 	conversation_key *key_ptr;	/** pointer to the key for this conversation */
 } conversation_t;
@@ -161,6 +161,13 @@ WS_DLL_PUBLIC void conversation_delete_proto_data(conversation_t *conv, const in
 
 WS_DLL_PUBLIC void conversation_set_dissector(conversation_t *conversation,
     const dissector_handle_t handle);
+
+WS_DLL_PUBLIC void conversation_set_dissector_from_frame_number(conversation_t *conversation,
+    const guint32 starting_frame_num, const dissector_handle_t handle);
+
+WS_DLL_PUBLIC dissector_handle_t conversation_get_dissector(conversation_t *conversation,
+    const guint32 frame_num);
+
 /**
  * Given two address/port pairs for a packet, search for a matching
  * conversation and, if found and it has a conversation dissector,
diff --git a/epan/dissectors/packet-atalk.c b/epan/dissectors/packet-atalk.c
index c62655a317..a02dfc27f4 100644
--- a/epan/dissectors/packet-atalk.c
+++ b/epan/dissectors/packet-atalk.c
@@ -853,7 +853,7 @@ dissect_atp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
       call_dissector_with_data(zip_atp_handle, new_tvb, pinfo, tree, &aspinfo);
     else {
       /* XXX need a conversation_get_dissector function ? */
-      if (!aspinfo.reply && !conversation->dissector_handle) {
+      if (!aspinfo.reply && !conversation_get_dissector(conversation, pinfo->fd->num)) {
         dissector_handle_t sub;
 
         /* if it's a known ASP function call ASP dissector
diff --git a/epan/dissectors/packet-hartip.c b/epan/dissectors/packet-hartip.c
index 72e768849f..444326f750 100644
--- a/epan/dissectors/packet-hartip.c
+++ b/epan/dissectors/packet-hartip.c
@@ -815,7 +815,7 @@ hartip_set_conversation(packet_info *pinfo)
                                      &pinfo->src, &pinfo->dst, pinfo->ptype,
                                      pinfo->srcport, 0, NO_PORT_B);
     if( (conversation == NULL) ||
-        (conversation->dissector_handle != hartip_udp_handle) ) {
+        (conversation_get_dissector(conversation, pinfo->fd->num) != hartip_udp_handle) ) {
       conversation = conversation_new(pinfo->fd->num,
                                       &pinfo->src, &pinfo->dst, pinfo->ptype,
                                       pinfo->srcport, 0, NO_PORT2);
diff --git a/epan/dissectors/packet-http.c b/epan/dissectors/packet-http.c
index 877e783c3d..9ba6022f2a 100644
--- a/epan/dissectors/packet-http.c
+++ b/epan/dissectors/packet-http.c
@@ -2046,7 +2046,7 @@ http_payload_subdissector(tvbuff_t *tvb, proto_tree *tree,
 		 * conversation (e.g., one we detected heuristically or via Decode-As) call the data
 		 * dissector directly.
 		 */
-		if (value_is_in_range(http_tcp_range, uri_port) || (conv && conv->dissector_handle == http_handle)) {
+		if (value_is_in_range(http_tcp_range, uri_port) || (conv && conversation_get_dissector(conv, pinfo->fd->num) == http_handle)) {
 			call_dissector(data_handle, tvb, pinfo, tree);
 		} else {
 			/* set pinfo->{src/dst port} and call the TCP sub-dissector lookup */
diff --git a/epan/dissectors/packet-l2tp.c b/epan/dissectors/packet-l2tp.c
index 2e742dee17..cc0293c40f 100644
--- a/epan/dissectors/packet-l2tp.c
+++ b/epan/dissectors/packet-l2tp.c
@@ -2415,7 +2415,7 @@ dissect_l2tp_udp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data
                              pinfo->srcport, pinfo->destport, 0);
     }
 
-    if ((conv == NULL) || (conv->dissector_handle != l2tp_udp_handle)) {
+    if ((conv == NULL) || (conversation_get_dissector(conv, pinfo->fd->num) != l2tp_udp_handle)) {
         conv = conversation_new(pinfo->fd->num, &pinfo->src, &pinfo->dst, PT_UDP,
                         pinfo->srcport, 0, NO_PORT2);
         conversation_set_dissector(conv, l2tp_udp_handle);
diff --git a/epan/dissectors/packet-snmp.c b/epan/dissectors/packet-snmp.c
index ec90e60a27..24f904ff9e 100644
--- a/epan/dissectors/packet-snmp.c
+++ b/epan/dissectors/packet-snmp.c
@@ -3329,7 +3329,7 @@ dissect_snmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_
 	if (pinfo->destport == UDP_PORT_SNMP) {
 		conversation = find_conversation(pinfo->fd->num, &pinfo->src, &pinfo->dst, PT_UDP,
 					   pinfo->srcport, 0, NO_PORT_B);
-		if( (conversation == NULL) || (conversation->dissector_handle!=snmp_handle) ) {
+		if( (conversation == NULL) || (conversation_get_dissector(conversation, pinfo->fd->num)!=snmp_handle) ) {
 			conversation = conversation_new(pinfo->fd->num, &pinfo->src, &pinfo->dst, PT_UDP,
 					    pinfo->srcport, 0, NO_PORT2);
 			conversation_set_dissector(conversation, snmp_handle);
diff --git a/epan/dissectors/packet-stun.c b/epan/dissectors/packet-stun.c
index 13885a9167..c7affc408e 100644
--- a/epan/dissectors/packet-stun.c
+++ b/epan/dissectors/packet-stun.c
@@ -1343,6 +1343,13 @@ dissect_stun_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, gboole
         }
     }
 
+    if (!PINFO_FD_VISITED(pinfo) && is_turn && (pinfo->ptype == PT_TCP)
+        && (msg_type_method == CONNECTION_BIND) && (msg_type_class == RESPONSE)) {
+        /* RFC 6062: after the ConnectionBind exchange, the connection is no longer framed as TURN;
+           instead, it is an unframed pass-through.
+           Starting from next frame set conversation dissector to data */
+        conversation_set_dissector_from_frame_number(conversation, pinfo->fd->num+1, data_handle);
+    }
     return reported_length;
 }
 
diff --git a/epan/dissectors/packet-tcp.c b/epan/dissectors/packet-tcp.c
index 657da75c78..de4f725bf7 100644
--- a/epan/dissectors/packet-tcp.c
+++ b/epan/dissectors/packet-tcp.c
@@ -4295,7 +4295,7 @@ dissect_tcpopt_rvbd_trpy(const ip_tcp_opt *optp _U_, tvbuff_t *tvb,
                 &pinfo->src, &pinfo->dst, pinfo->ptype,
                 pinfo->srcport, pinfo->destport, 0);
         }
-        if (conversation->dissector_handle != sport_handle) {
+        if (conversation_get_dissector(conversation, pinfo->fd->num) != sport_handle) {
             conversation_set_dissector(conversation, sport_handle);
         }
     } else if (data_handle != NULL) {
@@ -4308,7 +4308,7 @@ dissect_tcpopt_rvbd_trpy(const ip_tcp_opt *optp _U_, tvbuff_t *tvb,
                 &pinfo->src, &pinfo->dst, pinfo->ptype,
                 pinfo->srcport, pinfo->destport, 0);
         }
-        if (conversation->dissector_handle != data_handle) {
+        if (conversation_get_dissector(conversation, pinfo->fd->num) != data_handle) {
             conversation_set_dissector(conversation, data_handle);
         }
     }
diff --git a/epan/dissectors/packet-tftp.c b/epan/dissectors/packet-tftp.c
index 4b50a28a29..cd91bbdecf 100644
--- a/epan/dissectors/packet-tftp.c
+++ b/epan/dissectors/packet-tftp.c
@@ -568,7 +568,7 @@ dissect_tftp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
       (pinfo->match_uint == pinfo->destport)) {
     conversation = find_conversation(pinfo->fd->num, &pinfo->src, &pinfo->dst, PT_UDP,
                                      pinfo->srcport, 0, NO_PORT_B);
-    if( (conversation == NULL) || (conversation->dissector_handle != tftp_handle) ){
+    if( (conversation == NULL) || (conversation_get_dissector(conversation, pinfo->fd->num) != tftp_handle) ){
       conversation = conversation_new(pinfo->fd->num, &pinfo->src, &pinfo->dst, PT_UDP,
                                       pinfo->srcport, 0, NO_PORT2);
       conversation_set_dissector(conversation, tftp_handle);
@@ -576,7 +576,7 @@ dissect_tftp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
   } else {
     conversation = find_conversation(pinfo->fd->num, &pinfo->src, &pinfo->dst,
                                      pinfo->ptype, pinfo->srcport, pinfo->destport, 0);
-    if( (conversation == NULL) || (conversation->dissector_handle != tftp_handle) ){
+    if( (conversation == NULL) || (conversation_get_dissector(conversation, pinfo->fd->num) != tftp_handle) ){
       conversation = conversation_new(pinfo->fd->num, &pinfo->src, &pinfo->dst, PT_UDP,
                                       pinfo->destport, pinfo->srcport, 0);
       conversation_set_dissector(conversation, tftp_handle);