Wireshark · Ethereal-dev: [Ethereal-dev] [patch] h245 dissector fix

[Jeff Snyder <jeff@xxxxxxxxxxxxx>]

Hi, 

I've fixed the h245 dissector to handle multiple commands in a single PDU, 
which used to work in the pre-asn2eth h245 dissector. I've also bumped up the 
maximum number for messages per packet from 5 to 15, since it seems to be 
fairly common for packets to have 5 or more messages.

Please find the diff attached.

Thanks, 

Jeff

-- 
Jeff Snyder <jeff@xxxxxxxxxxxxx>
http://www.mxtelecom.com

diff -ur --exclude Entries ethereal/asn1/h245/packet-h245-template.c ethereal2/asn1/h245/packet-h245-template.c
--- ethereal/asn1/h245/packet-h245-template.c	2005-08-19 10:59:11.474658728 +0100
+++ ethereal2/asn1/h245/packet-h245-template.c	2005-08-18 18:45:44.000000000 +0100
@@ -2,7 +2,7 @@
  * Routines for h245 packet dissection
  * Copyright 2004, Anders Broman <anders.broman@xxxxxxxxxxxx>
  *
- * $Id: packet-h245-template.c,v 1.1.1.2 2005/08/15 14:45:15 jeff Exp $
+ * $Id: packet-h245-template.c,v 1.2 2005/08/18 17:45:44 jeff Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@xxxxxxxxxxxx>
@@ -57,6 +57,13 @@
 #define PSNAME "h245"
 #define PFNAME "h245"
 
+/*
+ * We assuming a certain maximum number of messaages per packet.
+ * we have to keep the pi_arr data for more than one packet at a time
+ * becase of the tap queueing.
+ */
+#define H245_MAX_MESSAGES_PER_PACKET 15
+
 static dissector_handle_t rtp_handle=NULL;
 static dissector_handle_t rtcp_handle=NULL;
 static dissector_table_t nsp_object_dissector_table;
@@ -72,7 +79,7 @@
 static int h245_tap = -1;
 static int ett_h245 = -1;
 static int h245dg_tap = -1;
-static h245_packet_info pi_arr[5]; /* We assuming a maximum of 5 H245 messaages per packet */
+static h245_packet_info pi_arr[H245_MAX_MESSAGES_PER_PACKET];
 static int pi_current=0;
 h245_packet_info *h245_pi=NULL;
 
@@ -234,18 +241,11 @@
 static void
 dissect_h245(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree)
 {
-    pi_current++;
-    if(pi_current==5){
-        pi_current=0;
-    }
-    h245_pi=&pi_arr[pi_current];
-
-    reset_h245_packet_info(h245_pi);
-       h245_pi->msg_type = H245_OTHER;
-
+	/*
+	 * MultimediaSystemControlMessage_handle is the handle for
+	 * dissect_h245_h245, so we don't want to do any h245_pi or tap stuff here.
+	 */
 	dissect_tpkt_encap(tvb, pinfo, parent_tree, h245_reassembly, MultimediaSystemControlMessage_handle);
-
-	tap_queue_packet(h245_tap, pinfo, h245_pi);
 }
 
 static void
@@ -255,23 +255,23 @@
 	proto_tree *tr;
 	guint32 offset=0;
 
-    pi_current++;
-    if(pi_current==5){
-      pi_current=0;
-    }
-    h245_pi=&pi_arr[pi_current];
-
-    reset_h245_packet_info(h245_pi);
-    h245_pi->msg_type = H245_OTHER;
-
 	if (check_col(pinfo->cinfo, COL_PROTOCOL)){
 		col_set_str(pinfo->cinfo, COL_PROTOCOL, "H.245");
 	}
 
 	it=proto_tree_add_protocol_format(parent_tree, proto_h245, tvb, 0, tvb_length(tvb), "H.245");
 	tr=proto_item_add_subtree(it, ett_h245);
-	dissect_h245_MultimediaSystemControlMessage(tvb, offset, pinfo ,tr, hf_h245_pdu_type);
-	tap_queue_packet(h245dg_tap, pinfo, h245_pi);
+
+	/* assume that whilst there is more tvb data, there are more h245 commands */
+	while ( tvb_length_remaining( tvb, offset>>3 )>0 ){
+		if(++pi_current==H245_MAX_MESSAGES_PER_PACKET) {
+			pi_current=0;
+		}
+		h245_pi=&pi_arr[pi_current];
+		offset = dissect_h245_MultimediaSystemControlMessage(tvb, offset, pinfo ,tr, hf_h245_pdu_type);
+		tap_queue_packet(h245dg_tap, pinfo, h245_pi);
+		offset = (offset+0x07) & 0xfffffff8;
+	}
 }
 
 int
diff -ur --exclude Entries ethereal/epan/dissectors/packet-h245.c ethereal2/epan/dissectors/packet-h245.c
--- ethereal/epan/dissectors/packet-h245.c	2005-08-19 10:59:40.662221544 +0100
+++ ethereal2/epan/dissectors/packet-h245.c	2005-08-19 11:01:43.733511864 +0100
@@ -1,6 +1,6 @@
 /* Do not modify this file.                                                   */
 /* It is created automatically by the ASN.1 to Ethereal dissector compiler    */
-/* .\packet-h245.c                                                            */
+/* ./packet-h245.c                                                            */
 /* ../../tools/asn2eth.py -X -e -p h245 -c h245.cnf -s packet-h245-template h245.asn */
 
 /* Input file: packet-h245-template.c */
@@ -9,7 +9,7 @@
  * Routines for h245 packet dissection
  * Copyright 2004, Anders Broman <anders.broman@xxxxxxxxxxxx>
  *
- * $Id: packet-h245.c,v 1.1.1.3 2005/08/15 14:45:17 jeff Exp $
+ * $Id: packet-h245.c,v 1.2 2005/08/18 17:45:44 jeff Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@xxxxxxxxxxxx>
@@ -64,6 +64,13 @@
 #define PSNAME "h245"
 #define PFNAME "h245"
 
+/*
+ * We assuming a certain maximum number of messaages per packet.
+ * we have to keep the pi_arr data for more than one packet at a time
+ * becase of the tap queueing.
+ */
+#define H245_MAX_MESSAGES_PER_PACKET 15
+
 static dissector_handle_t rtp_handle=NULL;
 static dissector_handle_t rtcp_handle=NULL;
 static dissector_table_t nsp_object_dissector_table;
@@ -79,7 +86,7 @@
 static int h245_tap = -1;
 static int ett_h245 = -1;
 static int h245dg_tap = -1;
-static h245_packet_info pi_arr[5]; /* We assuming a maximum of 5 H245 messaages per packet */
+static h245_packet_info pi_arr[H245_MAX_MESSAGES_PER_PACKET];
 static int pi_current=0;
 h245_packet_info *h245_pi=NULL;
 
@@ -16861,18 +16868,11 @@
 static void
 dissect_h245(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree)
 {
-    pi_current++;
-    if(pi_current==5){
-        pi_current=0;
-    }
-    h245_pi=&pi_arr[pi_current];
-
-    reset_h245_packet_info(h245_pi);
-       h245_pi->msg_type = H245_OTHER;
-
+	/*
+	 * MultimediaSystemControlMessage_handle is the handle for
+	 * dissect_h245_h245, so we don't want to do any h245_pi or tap stuff here.
+	 */
 	dissect_tpkt_encap(tvb, pinfo, parent_tree, h245_reassembly, MultimediaSystemControlMessage_handle);
-
-	tap_queue_packet(h245_tap, pinfo, h245_pi);
 }
 
 static void
@@ -16882,23 +16882,23 @@
 	proto_tree *tr;
 	guint32 offset=0;
 
-    pi_current++;
-    if(pi_current==5){
-      pi_current=0;
-    }
-    h245_pi=&pi_arr[pi_current];
-
-    reset_h245_packet_info(h245_pi);
-    h245_pi->msg_type = H245_OTHER;
-
 	if (check_col(pinfo->cinfo, COL_PROTOCOL)){
 		col_set_str(pinfo->cinfo, COL_PROTOCOL, "H.245");
 	}
 
 	it=proto_tree_add_protocol_format(parent_tree, proto_h245, tvb, 0, tvb_length(tvb), "H.245");
 	tr=proto_item_add_subtree(it, ett_h245);
-	dissect_h245_MultimediaSystemControlMessage(tvb, offset, pinfo ,tr, hf_h245_pdu_type);
-	tap_queue_packet(h245dg_tap, pinfo, h245_pi);
+
+	/* assume that whilst there is more tvb data, there are more h245 commands */
+	while ( tvb_length_remaining( tvb, offset>>3 )>0 ){
+		if(++pi_current==H245_MAX_MESSAGES_PER_PACKET) {
+			pi_current=0;
+		}
+		h245_pi=&pi_arr[pi_current];
+		offset = dissect_h245_MultimediaSystemControlMessage(tvb, offset, pinfo ,tr, hf_h245_pdu_type);
+		tap_queue_packet(h245dg_tap, pinfo, h245_pi);
+		offset = (offset+0x07) & 0xfffffff8;
+	}
 }
 
 int