RTPS: Added new filters rtps.guidPrefix.src and rtps.guidPrefix.dst

As well as in the rest of network protocols, in RTPS we have senders
and receivers of data. The atomic unit is not the host address (IP)
or the host address and port (UDP) but the guidPrefix. The guidPrefix
represents a single DomainParticipant, that very likely will be an
application. I have added filters to be able to differentiate from
source of information and destination of information. Before, the
only filter available was rtps.guidPrefix

Change-Id: I810d8b043796119c6e381bdbcb6061e0525ea272
Reviewed-on: https://code.wireshark.org/review/14466
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>

1 files changed, 45 insertions, 37 deletions

diff --git a/epan/dissectors/packet-rtps.c b/epan/dissectors/packet-rtps.c
index 687c83c236..1650bdc2a0 100644
--- a/epan/dissectors/packet-rtps.c
+++ b/epan/dissectors/packet-rtps.c
@@ -92,6 +92,8 @@ static int hf_rtps_nature_type                  = -1;
 
 static int hf_rtps_guid_prefix                  = -1;
 static int hf_rtps_guid_prefix_v2               = -1;
+static int hf_rtps_guid_prefix_v2_src           = -1;
+static int hf_rtps_guid_prefix_v2_dst           = -1;
 static int hf_rtps_host_id                      = -1;
 static int hf_rtps_app_id                       = -1;
 static int hf_rtps_app_id_instance_id           = -1;
@@ -1587,7 +1589,7 @@ static void rtps_util_add_guid_prefix_v1(proto_tree *tree, tvbuff_t *tvb, gint o
  */
 static void rtps_util_add_guid_prefix_v2(proto_tree *tree, tvbuff_t *tvb, gint offset,
                                       int hf_prefix, int hf_host_id, int hf_app_id,
-                                      int hf_instance_id) {
+                                      int hf_instance_id, int hf_prefix_extra) {
   if (tree) {
     proto_item *ti;
     proto_tree *guid_tree;
@@ -1596,6 +1598,12 @@ static void rtps_util_add_guid_prefix_v2(proto_tree *tree, tvbuff_t *tvb, gint o
     ti = proto_tree_add_item(tree, hf_prefix, tvb, offset, 12, ENC_NA);
     guid_tree = proto_item_add_subtree(ti, ett_rtps_guid_prefix);
 
+    /* Optional filter that can be guidPrefix.src or guidPrefix.dst */
+    if (hf_prefix_extra != 0) {
+      ti = proto_tree_add_item(tree, hf_prefix_extra, tvb, offset, 12, ENC_NA);
+      PROTO_ITEM_SET_HIDDEN(ti);
+    }
+
     /* Host Id */
     proto_tree_add_item(guid_tree, hf_host_id, tvb, offset, 4, ENC_BIG_ENDIAN);
 
@@ -3161,7 +3169,7 @@ static gboolean dissect_parameter_sequence_rti(proto_tree *rtps_parameter_tree,
       ENSURE_LENGTH(16);
       rtps_util_add_guid_prefix_v2(rtps_parameter_tree, tvb, offset,
         hf_rtps_sm_guid_prefix_v2, hf_rtps_sm_host_id, hf_rtps_sm_app_id,
-        hf_rtps_sm_instance_id);
+        hf_rtps_sm_instance_id, 0);
       rtps_util_add_entity_id(rtps_parameter_tree, tvb, offset+12,
         hf_rtps_sm_entity_id, hf_rtps_sm_entity_id_key, hf_rtps_sm_entity_id_kind,
         ett_rtps_entity, "virtualGUIDSuffix", NULL);
@@ -4403,10 +4411,10 @@ static gboolean dissect_parameter_sequence_v2(proto_tree *rtps_parameter_tree, p
     * +---------------+---------------+---------------+---------------+
     */
     case PID_DIRECTED_WRITE: {
-    ENSURE_LENGTH(16);
-    rtps_util_add_guid_prefix_v2(rtps_parameter_tree, tvb, offset, hf_rtps_sm_guid_prefix_v2,
-                    hf_rtps_sm_host_id, hf_rtps_sm_app_id, hf_rtps_sm_instance_id);
-    rtps_util_add_entity_id(rtps_parameter_tree, tvb, offset+12, hf_rtps_sm_entity_id,
+      ENSURE_LENGTH(16);
+      rtps_util_add_guid_prefix_v2(rtps_parameter_tree, tvb, offset, hf_rtps_sm_guid_prefix_v2,
+                    hf_rtps_sm_host_id, hf_rtps_sm_app_id, hf_rtps_sm_instance_id, 0);
+      rtps_util_add_entity_id(rtps_parameter_tree, tvb, offset+12, hf_rtps_sm_entity_id,
                     hf_rtps_sm_entity_id_key, hf_rtps_sm_entity_id_kind, ett_rtps_entity,
                     "guidSuffix", NULL);
     break;
@@ -4555,7 +4563,7 @@ static gboolean dissect_parameter_sequence_v2(proto_tree *rtps_parameter_tree, p
     case PID_ORIGINAL_WRITER_INFO:
       ENSURE_LENGTH(16);
       rtps_util_add_guid_prefix_v2(rtps_parameter_tree, tvb, offset, hf_rtps_sm_guid_prefix_v2,
-                    hf_rtps_sm_host_id, hf_rtps_sm_app_id, hf_rtps_sm_instance_id);
+                    hf_rtps_sm_host_id, hf_rtps_sm_app_id, hf_rtps_sm_instance_id, 0);
       rtps_util_add_entity_id(rtps_parameter_tree, tvb, offset+12, hf_rtps_sm_entity_id,
                     hf_rtps_sm_entity_id_key, hf_rtps_sm_entity_id_kind, ett_rtps_entity,
                     "virtualGUIDSuffix", NULL);
@@ -4848,7 +4856,7 @@ static void dissect_APP_ACK_CONF(tvbuff_t *tvb,
       /* Virtual Writer Guid */
       rtps_util_add_guid_prefix_v2(sil_tree_writer, tvb, offset,
         hf_rtps_sm_guid_prefix_v2, hf_rtps_sm_host_id, hf_rtps_sm_app_id,
-        hf_rtps_sm_instance_id);
+        hf_rtps_sm_instance_id, 0);
 
       rtps_util_add_entity_id(sil_tree_writer, tvb, offset+12,
         hf_rtps_sm_entity_id, hf_rtps_sm_entity_id_key, hf_rtps_sm_entity_id_kind,
@@ -5448,7 +5456,7 @@ static void dissect_DATA_v2(tvbuff_t *tvb, packet_info *pinfo, gint offset, guin
   /* If flag H is defined, read the GUID Prefix */
   if ((flags & FLAG_DATA_H) != 0) {
     rtps_util_add_guid_prefix_v2(tree, tvb, offset, hf_rtps_sm_guid_prefix_v2, hf_rtps_sm_host_id,
-                        hf_rtps_sm_app_id, hf_rtps_sm_instance_id);
+                        hf_rtps_sm_app_id, hf_rtps_sm_instance_id, 0);
 
     offset += 12;
   } else {
@@ -5563,7 +5571,7 @@ static void dissect_DATA_FRAG(tvbuff_t *tvb, packet_info *pinfo, gint offset, gu
   /* If flag H is defined, read the GUID Prefix */
   if ((flags & FLAG_DATA_H) != 0) {
     rtps_util_add_guid_prefix_v2(tree, tvb, offset, hf_rtps_sm_guid_prefix_v2,
-                    hf_rtps_sm_host_id, hf_rtps_sm_app_id, hf_rtps_sm_instance_id);
+                    hf_rtps_sm_host_id, hf_rtps_sm_app_id, hf_rtps_sm_instance_id, 0);
     offset += 12;
   } else {
     /* Flag H not set, use hostId, appId from the packet header */
@@ -6709,7 +6717,7 @@ static void dissect_RTPS_DATA(tvbuff_t *tvb, packet_info *pinfo, gint offset, gu
       guid_tree = proto_item_add_subtree(ti, ett_rtps_part_message_data);
 
       rtps_util_add_guid_prefix_v2(guid_tree, tvb, offset, hf_rtps_sm_guid_prefix_v2, hf_rtps_sm_host_id,
-                        hf_rtps_sm_app_id, hf_rtps_sm_instance_id);
+                        hf_rtps_sm_app_id, hf_rtps_sm_instance_id, 0);
       offset += 12;
 
       /* Kind */
@@ -7387,8 +7395,8 @@ void dissect_INFO_SRC(tvbuff_t *tvb, packet_info *pinfo, gint offset, guint8 fla
                         hf_rtps_sm_instance_id_v1, hf_rtps_sm_app_kind,
                         NULL);   /* Use default 'guidPrefix' */
   } else {
-      rtps_util_add_guid_prefix_v2(tree, tvb, offset, hf_rtps_guid_prefix_v2,
-                        hf_rtps_host_id, hf_rtps_app_id, hf_rtps_sm_instance_id);
+      rtps_util_add_guid_prefix_v2(tree, tvb, offset, hf_rtps_guid_prefix_v2_src,
+          hf_rtps_host_id, hf_rtps_app_id, hf_rtps_sm_instance_id, hf_rtps_guid_prefix_v2);
   }
 }
 
@@ -7515,8 +7523,8 @@ static void dissect_INFO_DST(tvbuff_t *tvb, packet_info *pinfo, gint offset, gui
                         hf_rtps_sm_instance_id_v1, hf_rtps_sm_app_kind,
                         NULL);
   } else {
-      rtps_util_add_guid_prefix_v2(tree, tvb, offset, hf_rtps_guid_prefix_v2,
-                        hf_rtps_host_id, hf_rtps_app_id, hf_rtps_sm_instance_id);
+      rtps_util_add_guid_prefix_v2(tree, tvb, offset, hf_rtps_guid_prefix_v2_dst,
+          hf_rtps_host_id, hf_rtps_app_id, hf_rtps_sm_instance_id, hf_rtps_guid_prefix_v2);
   }
 }
 
@@ -7764,13 +7772,12 @@ static gboolean dissect_rtps(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
                         hf_rtps_guid_prefix, hf_rtps_host_id, hf_rtps_app_id,
                         hf_rtps_app_id_instance_id, hf_rtps_app_id_app_kind, NULL);
     else
-      rtps_util_add_guid_prefix_v2(rtps_tree, tvb, offset+8, hf_rtps_guid_prefix_v2,
-                        hf_rtps_host_id, hf_rtps_app_id, hf_rtps_sm_instance_id);
+      rtps_util_add_guid_prefix_v2(rtps_tree, tvb, offset+8, hf_rtps_guid_prefix_v2_src,
+          hf_rtps_host_id, hf_rtps_app_id, hf_rtps_sm_instance_id, hf_rtps_guid_prefix_v2);
 
     guid.host_id = tvb_get_ntohl(tvb, offset+8);
     guid.app_id = tvb_get_ntohl(tvb, offset+12);
     guid.instance_id = tvb_get_ntohl(tvb, offset+16);
-
 #ifdef RTI_BUILD
     pinfo->guid_prefix_host = tvb_get_ntohl(tvb, offset + 8);
     pinfo->guid_prefix_app  = tvb_get_ntohl(tvb, offset + 12);
@@ -7778,7 +7785,6 @@ static gboolean dissect_rtps(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
     pinfo->guid_rtps2 = 1;
 #endif
   }
-
   /* Extract the domain id and participant index */
   {
     int domain_id, doffset, participant_idx = 0, nature;
@@ -8056,26 +8062,28 @@ void proto_register_rtps(void) {
     },
 
     /* Guid Prefix for the Packet ------------------------------------------ */
-    { &hf_rtps_guid_prefix, {
-        "guidPrefix",
-        "rtps.guidPrefix",
-        FT_UINT64,
-        BASE_HEX,
-        NULL,
-        0,
-        "GuidPrefix of the RTPS packet",
-        HFILL }
+    { &hf_rtps_guid_prefix,
+      { "guidPrefix", "rtps.guidPrefix",
+         FT_UINT64, BASE_HEX, NULL, 0,
+         "GuidPrefix of the RTPS packet", HFILL }
     },
 
-    { &hf_rtps_guid_prefix_v2, {
-        "guidPrefix",
-        "rtps.guidPrefix",
-        FT_BYTES,
-        BASE_NONE,
-        NULL,
-        0,
-        "a generic guidPrefix that is transmitted inside the submessage (this is NOT the guidPrefix described in the packet header",
-        HFILL }
+    { &hf_rtps_guid_prefix_v2,
+      { "guidPrefix", "rtps.guidPrefix",
+         FT_BYTES, BASE_NONE, NULL, 0,
+         "a generic guidPrefix that is transmitted inside the submessage (this is NOT the guidPrefix described in the packet header)", HFILL }
+    },
+
+    { &hf_rtps_guid_prefix_v2_src,
+      { "guidPrefix", "rtps.guidPrefix.src",
+         FT_BYTES, BASE_NONE, NULL, 0,
+         "the guidPrefix of the entity sending the sample", HFILL }
+    },
+
+    { &hf_rtps_guid_prefix_v2_dst,
+      { "guidPrefix", "rtps.guidPrefix.dst",
+         FT_BYTES, BASE_NONE, NULL, 0,
+         "the guidPrefix of the entity receiving the sample", HFILL }
     },
 
     /* Host ID ------------------------------------------------------------- */