From Mithun Roy:

The primary header in bundle protocol contains some offset values(destination
scheme offset, destination ssp offset, source scheme offset, source ssp offset,
etc). These are the offsets within the dictionary if the length of the
dictionary length is greater than 0. But if the dictionary length is 0, then
these offset refer to node number and service number respectively(according to
compressed bundle header encoding). For example if destination scheme offset is
2 and the destination ssp offset is 1, then the destination
EID(<node_number>.<service_number>) is 2.1. 

Currently the dtn dissector will consider these offsets to be actual offsets in
the dictionary even if the dictionary length is 0. So the values for the
EID's(destination, source, report, custodian) and their schemes are junk
values. For example if the destination scheme offset is 2 and the destination
ssp offset is 1 and the dictionary length is 0(which means the dictionary is
empty), then the destination scheme is 2 bytes after the beginning of the
metadata block(field after dictionary) and destination is 1 byte after the
beginning of the metadata block.

svn path=/trunk/; revision=30682

2 files changed, 337 insertions, 104 deletions

diff --git a/epan/dissectors/packet-dtn.c b/epan/dissectors/packet-dtn.c
index 6e6e9604ee..e7dea47dc8 100644
--- a/epan/dissectors/packet-dtn.c
+++ b/epan/dissectors/packet-dtn.c
@@ -667,6 +667,11 @@ dissect_primary_header(packet_info *pinfo, proto_tree *primary_tree, tvbuff_t *t
     int dest_scheme_offset, dest_ssp_offset, source_scheme_offset, source_ssp_offset;
     int report_scheme_offset, report_ssp_offset, cust_scheme_offset, cust_ssp_offset;
     int fragment_offset, total_adu_length;
+    int dst_scheme_pos, src_scheme_pos, rpt_scheme_pos, cust_scheme_pos;
+    int dst_scheme_len, src_scheme_len, rpt_scheme_len, cust_scheme_len;
+    int dst_ssp_len, src_ssp_len, rpt_ssp_len, cust_ssp_len;
+    gchar *src_node;
+    gchar *dst_node;
 
     guint8 srrflags;
     guint8 version;
@@ -763,41 +768,53 @@ dissect_primary_header(packet_info *pinfo, proto_tree *primary_tree, tvbuff_t *t
      */
 
     dest_scheme_offset = tvb_get_ntohs(tvb, offset);
+    dst_scheme_pos = offset;
+    dst_scheme_len = 2;
     proto_tree_add_item(primary_tree, hf_bundle_dest_scheme_offset,
 							tvb, offset, 2, FALSE);
     offset += 2;
 
     dest_ssp_offset = tvb_get_ntohs(tvb, offset);
+    dst_ssp_len = 2;
     proto_tree_add_item(primary_tree, hf_bundle_dest_ssp_offset,
 							tvb, offset, 2, FALSE);
     offset += 2;
 
     source_scheme_offset = tvb_get_ntohs(tvb, offset);
+    src_scheme_pos = offset;
+    src_scheme_len = 2;
     proto_tree_add_item(primary_tree, hf_bundle_source_scheme_offset,
 							tvb, offset, 2, FALSE);
     offset += 2;
 
     source_ssp_offset = tvb_get_ntohs(tvb, offset);
+    src_ssp_len = 2;
     proto_tree_add_item(primary_tree, hf_bundle_source_ssp_offset,
 							tvb, offset, 2, FALSE);
     offset += 2;
 
     report_scheme_offset = tvb_get_ntohs(tvb, offset);
+    rpt_scheme_pos = offset;
+    rpt_scheme_len = 2;
     proto_tree_add_item(primary_tree, hf_bundle_report_scheme_offset,
 							tvb, offset, 2, FALSE);
     offset += 2;
 
     report_ssp_offset = tvb_get_ntohs(tvb, offset);
+    rpt_ssp_len = 2;
     proto_tree_add_item(primary_tree, hf_bundle_report_ssp_offset,
 							tvb, offset, 2, FALSE);
     offset += 2;
 
     cust_scheme_offset = tvb_get_ntohs(tvb, offset);
+    cust_scheme_pos = offset;
+    cust_scheme_len = 2;
     proto_tree_add_item(primary_tree, hf_bundle_cust_scheme_offset,
 							tvb, offset, 2, FALSE);
     offset += 2;
 
     cust_ssp_offset = tvb_get_ntohs(tvb, offset);
+    cust_ssp_len = 2;
     proto_tree_add_item(primary_tree, hf_bundle_cust_ssp_offset,
 							tvb, offset, 2, FALSE);
     offset += 2;
@@ -829,80 +846,179 @@ dissect_primary_header(packet_info *pinfo, proto_tree *primary_tree, tvbuff_t *t
 					bundle_header_dict_length, "Dictionary");
     dict_tree = proto_item_add_subtree(dict_item, ett_dictionary);
     dict_ptr = (guint8 *) tvb_get_ptr(tvb, offset, bundle_header_dict_length);
-
     /*
-     * This pointer can be made to address outside the packet boundaries so we
-     * need to check for improperly formatted strings (no null termination).
+     * If the dictionary length is 0, then the CBHE block compression method is applied.
+     * So the scheme offset is the node number and the ssp offset is the service number.
+     * If destination scheme offset is 2 and destination ssp offset is 1, then the EID is
+     * ipn:2.1
      */
+    if(bundle_header_dict_length == 0)
+    {
+	/*
+ 	 * Destination info
+ 	 */
+	proto_tree_add_text(dict_tree, tvb, 0,
+			 	0, "Destination Scheme: %s",IPN_SCHEME_STR);
+	if(dest_scheme_offset == 0 && dest_ssp_offset == 0)
+	{
+		proto_tree_add_text(dict_tree, tvb, dst_scheme_pos,
+				dst_scheme_len + dst_ssp_len, "Destination: Null");
+	}
+	else
+	{
+		proto_tree_add_text(dict_tree, tvb, dst_scheme_pos,
+				dst_scheme_len + dst_ssp_len,
+				"Destination: %d.%d",dest_scheme_offset,dest_ssp_offset);
+	}
+	
+	/*
+ 	 * Source info
+ 	 */ 
+	proto_tree_add_text(dict_tree, tvb, 0,
+			 		0, "Source Scheme: %s",IPN_SCHEME_STR);
+	if(source_scheme_offset == 0 && source_ssp_offset == 0)
+	{
+		proto_tree_add_text(dict_tree, tvb, src_scheme_pos,
+				src_scheme_len + src_ssp_len, "Source: Null");
+	}
+	else
+	{
+		proto_tree_add_text(dict_tree, tvb, src_scheme_pos,
+				src_scheme_len + src_ssp_len,
+				"Source: %d.%d",source_scheme_offset,source_ssp_offset);
+	}
 
-    /*
-     * Destination info
-     */
+	/*
+ 	 * Report to info
+ 	 */ 
+	proto_tree_add_text(dict_tree, tvb, 0,
+			 		0, "Report Scheme: %s",IPN_SCHEME_STR);
+	if(report_scheme_offset == 0 && report_ssp_offset == 0)
+	{
+		proto_tree_add_text(dict_tree, tvb, rpt_scheme_pos,
+				rpt_scheme_len + rpt_ssp_len, "Report: Null");
+	}
+	else
+	{
+		proto_tree_add_text(dict_tree, tvb, rpt_scheme_pos,
+				rpt_scheme_len + rpt_ssp_len,
+				"Report: %d.%d",report_scheme_offset,report_ssp_offset);
+	}
+
+	/*
+ 	 * Custodian info
+ 	 */ 
+	proto_tree_add_text(dict_tree, tvb, 0,
+			 		0, "Custodian Scheme: %s",IPN_SCHEME_STR);
+	if(cust_scheme_offset == 0 && cust_ssp_offset == 0)
+	{
+		proto_tree_add_text(dict_tree, tvb, cust_scheme_pos,
+				cust_scheme_len + cust_ssp_len, "Custodian: Null");
+	}
+	else
+	{
+		proto_tree_add_text(dict_tree, tvb, cust_scheme_pos,
+				cust_scheme_len + cust_ssp_len,
+				"Custodian: %d.%d",cust_scheme_offset,cust_ssp_offset);
+	}
+	src_node = ep_alloc(NODE_NAME_STR_SIZE);
+	dst_node = ep_alloc(NODE_NAME_STR_SIZE);
 
-    string_ptr = tvb_get_ephemeral_stringz(tvb, offset + dest_scheme_offset, &string_length);
+	if(source_scheme_offset == 0 && source_ssp_offset == 0)
+	{
+		g_snprintf(src_node,5,"Null");
+	}
+	else
+	{
+		g_snprintf(src_node,NODE_NAME_STR_SIZE,"%s:%d.%d",IPN_SCHEME_STR, source_scheme_offset, source_ssp_offset);
+	}
+	if(dest_scheme_offset == 0 && dest_ssp_offset == 0)
+	{
+		g_snprintf(dst_node,5,"Null");
+	}
+	else
+	{
+		g_snprintf(dst_node,NODE_NAME_STR_SIZE,"%s:%d.%d",IPN_SCHEME_STR, dest_scheme_offset, dest_ssp_offset);
+	}
 
-    proto_tree_add_text(dict_tree, tvb, offset + dest_scheme_offset,
-				(gint)strlen((char *) (dict_ptr + dest_scheme_offset)),
-						"Destination Scheme: %s", string_ptr);
-    string_ptr = tvb_get_ephemeral_stringz(tvb, offset + dest_ssp_offset, &string_length);
-    dest_item = proto_tree_add_text(dict_tree, tvb, offset + dest_ssp_offset,
-				(gint)strlen((char *) (dict_ptr + dest_ssp_offset)), " ");
-    proto_item_set_text(dest_item, "Destination: %s", string_ptr);
+	col_add_fstr(pinfo->cinfo, COL_INFO, "%s > %s", src_node,dst_node);
+    }
 
     /*
-     * Source info
+     * This pointer can be made to address outside the packet boundaries so we
+     * need to check for improperly formatted strings (no null termination).
      */
 
-    string_ptr = tvb_get_ephemeral_stringz(tvb,
-				offset + source_scheme_offset, &string_length);
-    source_scheme_item = proto_tree_add_text(dict_tree, tvb, offset+source_scheme_offset,
-				(gint)strlen((char *) (dict_ptr + source_scheme_offset)), " ");
-    proto_item_set_text(source_scheme_item, "Source Scheme: %s", string_ptr);
-    string_ptr = tvb_get_ephemeral_stringz(tvb,
-				offset + source_ssp_offset, &string_length);
-    source_item = proto_tree_add_text(dict_tree, tvb, offset + source_ssp_offset,
-				(gint)strlen((char *) (dict_ptr + source_ssp_offset)), " ");
-    proto_item_set_text(source_item, "Source: %s", string_ptr);
-
+    else
+    {
     /*
-     * Report to info
+     * Destination info
      */
+	    string_ptr = tvb_get_ephemeral_stringz(tvb, offset + dest_scheme_offset, &string_length);
 
-    string_ptr = tvb_get_ephemeral_stringz(tvb,
-				offset + report_scheme_offset, &string_length);
-    rpt_scheme_item = proto_tree_add_text(dict_tree, tvb, offset + report_scheme_offset,
-				(gint)strlen((char *) (dict_ptr + report_scheme_offset)), " ");
-    proto_item_set_text(rpt_scheme_item, "Report To Scheme: %s", string_ptr);
-    string_ptr = tvb_get_ephemeral_stringz(tvb,
-				offset + report_ssp_offset, &string_length);
-    rpt_item = proto_tree_add_text(dict_tree, tvb, offset + report_ssp_offset,
-				(gint)strlen((char *) (dict_ptr + report_ssp_offset)), " ");
-    proto_item_set_text(rpt_item, "Report To: %s", string_ptr);
+	    proto_tree_add_text(dict_tree, tvb, offset + dest_scheme_offset,
+					(gint)strlen((char *) (dict_ptr + dest_scheme_offset)),
+							"Destination Scheme: %s", string_ptr);
+	    string_ptr = tvb_get_ephemeral_stringz(tvb, offset + dest_ssp_offset, &string_length);
+	    dest_item = proto_tree_add_text(dict_tree, tvb, offset + dest_ssp_offset,
+					(gint)strlen((char *) (dict_ptr + dest_ssp_offset)), " ");
+	    proto_item_set_text(dest_item, "Destination: %s", string_ptr);
 
-    /*
-     * Custodian info
-     */
+	    /*
+	     * Source info
+	     */
+			
+	    string_ptr = tvb_get_ephemeral_stringz(tvb,
+					offset + source_scheme_offset, &string_length);
+	    source_scheme_item = proto_tree_add_text(dict_tree, tvb, offset+source_scheme_offset,
+					(gint)strlen((char *) (dict_ptr + source_scheme_offset)), " ");
+	    proto_item_set_text(source_scheme_item, "Source Scheme: %s", string_ptr);
+	    string_ptr = tvb_get_ephemeral_stringz(tvb,
+					offset + source_ssp_offset, &string_length);
+	    source_item = proto_tree_add_text(dict_tree, tvb, offset + source_ssp_offset,
+					(gint)strlen((char *) (dict_ptr + source_ssp_offset)), " ");
+	    proto_item_set_text(source_item, "Source: %s", string_ptr);
 
-    string_ptr = tvb_get_ephemeral_stringz(tvb,
-				offset + cust_scheme_offset, &string_length);
-    cust_scheme_item = proto_tree_add_text(dict_tree, tvb, offset + cust_scheme_offset,
-				(gint)strlen((char *) (dict_ptr + cust_scheme_offset)), " ");
-    proto_item_set_text(cust_scheme_item, "Custodian Scheme: %s", string_ptr);
-    string_ptr = tvb_get_ephemeral_stringz(tvb,
-				offset + cust_ssp_offset, &string_length);
-    cust_item = proto_tree_add_text(dict_tree, tvb, offset + cust_ssp_offset,
-				(gint)strlen((char *) (dict_ptr + cust_ssp_offset)), " ");
-    proto_item_set_text(cust_item, "Custodian: %s", string_ptr);
+	    /*
+	     * Report to info
+	     */
 
-    /*
-     * Add Source/Destination to INFO Field
-     */
+	    string_ptr = tvb_get_ephemeral_stringz(tvb,
+					offset + report_scheme_offset, &string_length);
+	    rpt_scheme_item = proto_tree_add_text(dict_tree, tvb, offset + report_scheme_offset,
+					(gint)strlen((char *) (dict_ptr + report_scheme_offset)), " ");
+	    proto_item_set_text(rpt_scheme_item, "Report To Scheme: %s", string_ptr);
+	    string_ptr = tvb_get_ephemeral_stringz(tvb,
+					offset + report_ssp_offset, &string_length);
+	    rpt_item = proto_tree_add_text(dict_tree, tvb, offset + report_ssp_offset,
+					(gint)strlen((char *) (dict_ptr + report_ssp_offset)), " ");
+	    proto_item_set_text(rpt_item, "Report To: %s", string_ptr);
 
-    col_add_fstr(pinfo->cinfo, COL_INFO, "%s:%s > %s:%s",
-				dict_ptr + source_scheme_offset, dict_ptr + source_ssp_offset,
-				dict_ptr + dest_scheme_offset, dict_ptr + dest_ssp_offset);
-    offset += bundle_header_dict_length;	/*Skip over dictionary*/
+	    /*
+	     * Custodian info
+	     */
+			
+	    string_ptr = tvb_get_ephemeral_stringz(tvb,
+					offset + cust_scheme_offset, &string_length);
+	    cust_scheme_item = proto_tree_add_text(dict_tree, tvb, offset + cust_scheme_offset,
+					(gint)strlen((char *) (dict_ptr + cust_scheme_offset)), " ");
+	    proto_item_set_text(cust_scheme_item, "Custodian Scheme: %s", string_ptr);
+	    string_ptr = tvb_get_ephemeral_stringz(tvb,
+					offset + cust_ssp_offset, &string_length);
+	    cust_item = proto_tree_add_text(dict_tree, tvb, offset + cust_ssp_offset,
+					(gint)strlen((char *) (dict_ptr + cust_ssp_offset)), " ");
+	    proto_item_set_text(cust_item, "Custodian: %s", string_ptr);
+
+	    /* 
+	     * Add Source/Destination to INFO Field 
+	     */
+
+	    col_add_fstr(pinfo->cinfo, COL_INFO, "%s:%s > %s:%s",
+					dict_ptr + source_scheme_offset, dict_ptr + source_ssp_offset,
+					dict_ptr + dest_scheme_offset, dict_ptr + dest_ssp_offset);
 
+    }
+    offset += bundle_header_dict_length;	/*Skip over dictionary*/
     /*
      * Do this only if Fragment Flag is set
      */
@@ -940,16 +1056,23 @@ dissect_version_5_primary_header(packet_info *pinfo,
     int bundle_processing_control_flags;
     guint8 cosflags;
     guint8 *dict_ptr;
+    gchar  *string_ptr;
+    gint   string_length;
     int offset;		/*Total offset into frame (frame_offset + convergence layer size)*/
     int sdnv_length;
     int dest_scheme_offset, dest_ssp_offset, source_scheme_offset, source_ssp_offset;
     int report_scheme_offset, report_ssp_offset, cust_scheme_offset, cust_ssp_offset;
+    int dst_scheme_pos, src_scheme_pos, rpt_scheme_pos, cust_scheme_pos;
+    int dst_scheme_len, src_scheme_len, rpt_scheme_len, cust_scheme_len;
+    int dst_ssp_len, src_ssp_len, rpt_ssp_len, cust_ssp_len;
     int fragment_offset, total_adu_length;
     int timestamp;
     time_t time_since_2000;
     int timestamp_sequence;
     int lifetime;
     char *time_string;
+    gchar *src_node;
+    gchar *dst_node;
     guint8 srrflags;
     proto_item *srr_flag_item = NULL;
     proto_tree *srr_flag_tree = NULL;
@@ -1065,6 +1188,8 @@ dissect_version_5_primary_header(packet_info *pinfo,
      */
 
     dest_scheme_offset = evaluate_sdnv(tvb, offset, &sdnv_length);
+    dst_scheme_pos = offset;
+    dst_scheme_len = sdnv_length;
     dest_scheme_offset_item = proto_tree_add_text(primary_tree, tvb, offset, sdnv_length, " ");
     if((dest_scheme_offset < 0) || (dest_scheme_offset > bundle_header_length)) {
 	proto_item_set_text(dest_scheme_offset_item, "Destination Scheme Offset: Error");
@@ -1075,6 +1200,7 @@ dissect_version_5_primary_header(packet_info *pinfo,
     offset += sdnv_length;
 
     dest_ssp_offset = evaluate_sdnv(tvb, offset, &sdnv_length);
+    dst_ssp_len = sdnv_length;
     dest_ssp_offset_item = proto_tree_add_text(primary_tree, tvb, offset, sdnv_length, " ");
     if((dest_ssp_offset < 0) || (dest_ssp_offset > bundle_header_length)) {
 	proto_item_set_text(dest_ssp_offset_item, "Destination SSP Offset: Error");
@@ -1085,6 +1211,8 @@ dissect_version_5_primary_header(packet_info *pinfo,
     offset += sdnv_length;
 
     source_scheme_offset = evaluate_sdnv(tvb, offset, &sdnv_length);
+    src_scheme_pos = offset;
+    src_scheme_len = sdnv_length;
     source_scheme_offset_item = proto_tree_add_text(primary_tree, tvb, offset, sdnv_length, " ");
     if((source_scheme_offset < 0) || (source_scheme_offset > bundle_header_length)) {
 	proto_item_set_text(source_scheme_offset_item, "Source Scheme Offset: Error");
@@ -1095,6 +1223,7 @@ dissect_version_5_primary_header(packet_info *pinfo,
     offset += sdnv_length;
 
     source_ssp_offset = evaluate_sdnv(tvb, offset, &sdnv_length);
+    src_ssp_len = sdnv_length;
     source_ssp_offset_item = proto_tree_add_text(primary_tree, tvb, offset, sdnv_length, " ");
     if((source_ssp_offset < 0) || (source_ssp_offset > bundle_header_length)) {
 	proto_item_set_text(source_ssp_offset_item, "Source SSP Offset: Error");
@@ -1105,6 +1234,8 @@ dissect_version_5_primary_header(packet_info *pinfo,
     offset += sdnv_length;
 
     report_scheme_offset = evaluate_sdnv(tvb, offset, &sdnv_length);
+    rpt_scheme_pos = offset;
+    rpt_scheme_len = sdnv_length;
     report_scheme_offset_item = proto_tree_add_text(primary_tree, tvb, offset, sdnv_length, " ");
     if((report_scheme_offset < 0) || (report_scheme_offset > bundle_header_length)) {
 	proto_item_set_text(report_scheme_offset_item, "Report Scheme Offset: Error");
@@ -1115,6 +1246,7 @@ dissect_version_5_primary_header(packet_info *pinfo,
     offset += sdnv_length;
 
     report_ssp_offset = evaluate_sdnv(tvb, offset, &sdnv_length);
+    rpt_ssp_len = sdnv_length;
     report_ssp_offset_item = proto_tree_add_text(primary_tree, tvb, offset, sdnv_length, " ");
     if((report_ssp_offset < 0) || (report_ssp_offset > bundle_header_length)) {
 	proto_item_set_text(report_ssp_offset_item, "Report SSP Offset: Error");
@@ -1125,6 +1257,8 @@ dissect_version_5_primary_header(packet_info *pinfo,
     offset += sdnv_length;
 
     cust_scheme_offset = evaluate_sdnv(tvb, offset, &sdnv_length);
+    cust_scheme_pos = offset;
+    cust_scheme_len = sdnv_length;
     cust_scheme_offset_item = proto_tree_add_text(primary_tree, tvb, offset, sdnv_length, " ");
     if((cust_scheme_offset < 0) || (cust_scheme_offset > bundle_header_length)) {
 	proto_item_set_text(cust_scheme_offset_item, "Custodian Scheme Offset: Error");
@@ -1135,6 +1269,7 @@ dissect_version_5_primary_header(packet_info *pinfo,
     offset += sdnv_length;
 
     cust_ssp_offset = evaluate_sdnv(tvb, offset, &sdnv_length);
+    cust_ssp_len = sdnv_length;
     cust_ssp_offset_item = proto_tree_add_text(primary_tree, tvb, offset, sdnv_length, " ");
     if((cust_ssp_offset < 0) || (cust_ssp_offset > bundle_header_length)) {
 	proto_item_set_text(cust_ssp_offset_item, "Custodian SSP Offset: Error");
@@ -1169,10 +1304,12 @@ dissect_version_5_primary_header(packet_info *pinfo,
 	}
 	proto_item_set_text(timestamp_sequence_item,
 		"Timestamp Sequence Number: 0x%" G_GINT64_MODIFIER "x", ts_seq);
+	proto_item_set_text(timestamp_sequence_item, "Timestamp Sequence Number: Error");
+	return 0;
     }
     else {
-	proto_item_set_text(timestamp_sequence_item,
-				"Timestamp Sequence Number: %d", timestamp_sequence);
+    	proto_item_set_text(timestamp_sequence_item,
+ 				"Timestamp Sequence Number: %d", timestamp_sequence);
     }
     offset += sdnv_length;
 
@@ -1206,62 +1343,156 @@ dissect_version_5_primary_header(packet_info *pinfo,
     dict_tree = proto_item_add_subtree(dict_item, ett_dictionary);
     dict_ptr = (guint8 *) tvb_get_ptr(tvb, offset, bundle_header_dict_length);
 
-    /*
-     * This pointer can be made to address outside the packet boundaries so we
-     * need to check for improperly formatted strings (no null termination).
-     */
+    if(bundle_header_dict_length == 0)
+    {
+	/*
+ 	 * Destination info
+ 	 */ 
+	proto_tree_add_text(dict_tree, tvb, 0,
+			 	0, "Destination Scheme: %s",IPN_SCHEME_STR);
+	if(dest_scheme_offset == 0 && dest_ssp_offset == 0)
+	{
+		proto_tree_add_text(dict_tree, tvb, dst_scheme_pos,
+				dst_scheme_len + dst_ssp_len, "Destination: Null");
+	}
+	else
+	{
+		proto_tree_add_text(dict_tree, tvb, dst_scheme_pos,
+				dst_scheme_len + dst_ssp_len,
+				"Destination: %d.%d",dest_scheme_offset,dest_ssp_offset);
+	}
+	
+	/*
+ 	 * Source info
+ 	 */ 
+	proto_tree_add_text(dict_tree, tvb, 0,
+			 		0, "Source Scheme: %s",IPN_SCHEME_STR);
+	if(source_scheme_offset == 0 && source_ssp_offset == 0)
+	{
+		proto_tree_add_text(dict_tree, tvb, src_scheme_pos,
+				src_scheme_len + src_ssp_len, "Source: Null");
+	}
+	else
+	{
+		proto_tree_add_text(dict_tree, tvb, src_scheme_pos,
+				src_scheme_len + src_ssp_len,
+				"Source: %d.%d",source_scheme_offset,source_ssp_offset);
+	}
 
-    /*
-     * Destination info
-     */
+	/*
+ 	 * Report to info
+ 	 */ 
+	proto_tree_add_text(dict_tree, tvb, 0,
+			 		0, "Report Scheme: %s",IPN_SCHEME_STR);
+	if(report_scheme_offset == 0 && report_ssp_offset == 0)
+	{
+		proto_tree_add_text(dict_tree, tvb, rpt_scheme_pos,
+				rpt_scheme_len + rpt_ssp_len, "Report: Null");
+	}
+	else
+	{
+		proto_tree_add_text(dict_tree, tvb, rpt_scheme_pos,
+				rpt_scheme_len + rpt_ssp_len,
+				"Report: %d.%d",report_scheme_offset,report_ssp_offset);
+	}
 
-    tvb_ensure_bytes_exist(tvb, offset, dest_scheme_offset);
-    proto_tree_add_item(dict_tree, hf_bundle_dest_scheme, tvb, offset + dest_scheme_offset,
-				(gint)strlen((char *) (dict_ptr + dest_scheme_offset)), FALSE);
-    tvb_ensure_bytes_exist(tvb, offset, dest_ssp_offset);
-    proto_tree_add_item(dict_tree, hf_bundle_dest_ssp, tvb, offset + dest_ssp_offset,
-				(gint)strlen((char *) (dict_ptr + dest_ssp_offset)), FALSE);
+	/*
+ 	 * Custodian info
+ 	 */ 
+	proto_tree_add_text(dict_tree, tvb, 0,
+			 		0, "Custodian Scheme: %s",IPN_SCHEME_STR);
+	if(cust_scheme_offset == 0 && cust_ssp_offset == 0)
+	{
+		proto_tree_add_text(dict_tree, tvb, cust_scheme_pos,
+				cust_scheme_len + cust_ssp_len, "Custodian: Null");
+	}
+	else
+	{
+		proto_tree_add_text(dict_tree, tvb, cust_scheme_pos,
+				cust_scheme_len + cust_ssp_len,
+				"Custodian: %d.%d",cust_scheme_offset,cust_ssp_offset);
+	}
+	src_node = ep_alloc(NODE_NAME_STR_SIZE);
+	dst_node = ep_alloc(NODE_NAME_STR_SIZE);
 
-    /*
-     * Destination info
-     */
+	if(source_scheme_offset == 0 && source_ssp_offset == 0)
+	{
+		g_snprintf(src_node,5,"Null");
+	}
+	else
+	{
+		g_snprintf(src_node,NODE_NAME_STR_SIZE,"%s:%d.%d",IPN_SCHEME_STR, source_scheme_offset, source_ssp_offset);
+	}
+	if(dest_scheme_offset == 0 && dest_ssp_offset == 0)
+	{
+		g_snprintf(dst_node,5,"Null");
+	}
+	else
+	{
+		g_snprintf(dst_node,NODE_NAME_STR_SIZE,"%s:%d.%d",IPN_SCHEME_STR, dest_scheme_offset, dest_ssp_offset);
+	}
 
-    tvb_ensure_bytes_exist(tvb, offset, source_scheme_offset);
-    proto_tree_add_item(dict_tree, hf_bundle_source_scheme, tvb, offset + source_scheme_offset,
-				(gint)strlen((char *) (dict_ptr + source_scheme_offset)), FALSE);
-    tvb_ensure_bytes_exist(tvb, offset, source_ssp_offset);
-    proto_tree_add_item(dict_tree, hf_bundle_source_ssp, tvb, offset + source_ssp_offset,
-				(gint)strlen((char *) (dict_ptr + source_ssp_offset)), FALSE);
+	col_add_fstr(pinfo->cinfo, COL_INFO, "%s > %s", src_node, dst_node);
+    }
+    else
+    {
+	    /*
+	     * This pointer can be made to address outside the packet boundaries so we
+	     * need to check for improperly formatted strings (no null termination).
+	     */
 
-    /*
-     * Report to info
-     */
+	    /*
+	     * Destination info
+	     */
 
-    tvb_ensure_bytes_exist(tvb, offset, report_scheme_offset);
-    proto_tree_add_item(dict_tree, hf_bundle_report_scheme, tvb, offset + report_scheme_offset,
-				(gint)strlen((char *) (dict_ptr + report_scheme_offset)), FALSE);
-    tvb_ensure_bytes_exist(tvb, offset, report_ssp_offset);
-    proto_tree_add_item(dict_tree, hf_bundle_report_ssp, tvb, offset + report_ssp_offset,
-				(gint)strlen((char *) (dict_ptr + report_ssp_offset)), FALSE);
+	    tvb_ensure_bytes_exist(tvb, offset, dest_scheme_offset);
+	    proto_tree_add_item(dict_tree, hf_bundle_dest_scheme, tvb, offset + dest_scheme_offset,
+					(gint)strlen((char *) (dict_ptr + dest_scheme_offset)), FALSE);
+	    tvb_ensure_bytes_exist(tvb, offset, dest_ssp_offset);
+	    string_ptr = tvb_get_ephemeral_stringz(tvb, offset + dest_ssp_offset, &string_length);
+	    proto_tree_add_item(dict_tree, hf_bundle_dest_ssp, tvb, offset + dest_ssp_offset,
+					(gint)strlen((char *) (dict_ptr + dest_ssp_offset)), FALSE);
 
-    /*
-     * Custodian info
-     */
+	    /*
+	     * Destination info
+	     */
+
+	    tvb_ensure_bytes_exist(tvb, offset, source_scheme_offset);
+	    proto_tree_add_item(dict_tree, hf_bundle_source_scheme, tvb, offset + source_scheme_offset,
+					(gint)strlen((char *) (dict_ptr + source_scheme_offset)), FALSE);
+	    tvb_ensure_bytes_exist(tvb, offset, source_ssp_offset);
+	    string_ptr = tvb_get_ephemeral_stringz(tvb, offset + source_ssp_offset, &string_length);
+	    proto_tree_add_item(dict_tree, hf_bundle_source_ssp, tvb, offset + source_ssp_offset,
+					(gint)strlen((char *) (dict_ptr + source_ssp_offset)), FALSE);
 
-    tvb_ensure_bytes_exist(tvb, offset, cust_scheme_offset);
-    proto_tree_add_item(dict_tree, hf_bundle_custodian_scheme, tvb, offset + cust_scheme_offset,
-				(gint)strlen((char *) (dict_ptr + cust_scheme_offset)), FALSE);
+	    /*
+	     * Report to info
+	     */
 
-    tvb_ensure_bytes_exist(tvb, offset, cust_ssp_offset);
-    proto_tree_add_item(dict_tree, hf_bundle_custodian_ssp, tvb, offset + cust_ssp_offset,
-				(gint)strlen((char *) (dict_ptr + cust_ssp_offset)), FALSE);
+	    tvb_ensure_bytes_exist(tvb, offset, report_scheme_offset);
+	    proto_tree_add_item(dict_tree, hf_bundle_report_scheme, tvb, offset + report_scheme_offset,
+					(gint)strlen((char *) (dict_ptr + report_scheme_offset)), FALSE);
+	    tvb_ensure_bytes_exist(tvb, offset, report_ssp_offset);
+	    proto_tree_add_item(dict_tree, hf_bundle_report_ssp, tvb, offset + report_ssp_offset,
+					(gint)strlen((char *) (dict_ptr + report_ssp_offset)), FALSE);
 
-    /*
-     * Add Source/Destination to INFO Field
-     */
+	    /*
+	     * Custodian info
+	     */
+
+	    tvb_ensure_bytes_exist(tvb, offset, cust_scheme_offset);
+	    proto_tree_add_item(dict_tree, hf_bundle_custodian_scheme, tvb, offset + cust_scheme_offset,
+					(gint)strlen((char *) (dict_ptr + cust_scheme_offset)), FALSE);
+
+	    tvb_ensure_bytes_exist(tvb, offset, cust_ssp_offset);
+	    proto_tree_add_item(dict_tree, hf_bundle_custodian_ssp, tvb, offset + cust_ssp_offset,
+					(gint)strlen((char *) (dict_ptr + cust_ssp_offset)), FALSE);
+
+	    /* 
+	     * Add Source/Destination to INFO Field 
+	     */
 
-    if(check_col(pinfo->cinfo, COL_INFO)) {
-	col_add_fstr(pinfo->cinfo, COL_INFO, "%s:%s > %s:%s",
+		col_add_fstr(pinfo->cinfo, COL_INFO, "%s:%s > %s:%s",
 			dict_ptr + source_scheme_offset, dict_ptr + source_ssp_offset,
 			dict_ptr + dest_scheme_offset, dict_ptr + dest_ssp_offset);
     }
diff --git a/epan/dissectors/packet-dtn.h b/epan/dissectors/packet-dtn.h
index 4c09121479..53900b21ee 100644
--- a/epan/dissectors/packet-dtn.h
+++ b/epan/dissectors/packet-dtn.h
@@ -132,3 +132,5 @@
 #define BLOCK_CONTROL_NOT_PROCESSED     0x20
 #define BLOCK_CONTROL_EID_REFERENCE     0x40
 
+#define IPN_SCHEME_STR			"ipn"
+#define NODE_NAME_STR_SIZE		24