ZigBee: fix ZCL configure reporting response parsing

If configure reporting succeeds for all attributes, then the response
contains only a success status byte but if any attribute fails, then
every record contains a direction byte and attribute identifier.

By handling the "all successful" case specially, add an expert info
message to indicate a problem if the message length indicates that we
have hit this special case but the status is not "success".

Change-Id: I3facae8ac07f1a249cc6ae1b2454f8381151355b
Reviewed-on: https://code.wireshark.org/review/22557
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>

1 files changed, 30 insertions, 10 deletions

diff --git a/epan/dissectors/packet-zbee-zcl.c b/epan/dissectors/packet-zbee-zcl.c
index 7d6b79fa89..5d6dd1ee52 100644
--- a/epan/dissectors/packet-zbee-zcl.c
+++ b/epan/dissectors/packet-zbee-zcl.c
@@ -29,6 +29,7 @@
 #include "config.h"
 
 #include <epan/packet.h>
+#include <epan/expert.h>
 
 #include "packet-zbee.h"
 #include "packet-zbee-nwk.h"
@@ -138,6 +139,8 @@ static gint ett_zbee_zcl_fcf = -1;
 static gint ett_zbee_zcl_attr[ZBEE_ZCL_NUM_ATTR_ETT];
 static gint ett_zbee_zcl_array_elements[ZBEE_ZCL_NUM_ARRAY_ELEM_ETT];
 
+static expert_field ei_cfg_rpt_rsp_short_non_success = EI_INIT;
+
 /* Dissector List. */
 static dissector_table_t    zbee_zcl_dissector_table;
 
@@ -1217,7 +1220,7 @@ static void dissect_zcl_config_report(tvbuff_t *tvb, packet_info *pinfo _U_, pro
  *@param offset pointer to offset from caller
  *@param cluster_id cluster id
 */
-static void dissect_zcl_config_report_resp(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree,
+static void dissect_zcl_config_report_resp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                 guint *offset, guint16 cluster_id)
 {
     proto_tree *sub_tree;
@@ -1226,21 +1229,27 @@ static void dissect_zcl_config_report_resp(tvbuff_t *tvb, packet_info *pinfo _U_
     guint i = 0;
 
     tvb_len = tvb_captured_length(tvb);
-    while ( *offset < tvb_len && i < ZBEE_ZCL_NUM_ATTR_ETT ) {
 
+    /* Special case when all attributes configured successfully */
+    if ( *offset == tvb_len - 1 ) {
+        /* Dissect the status */
+        if ( dissect_zcl_attr_uint8(tvb, tree, offset, &hf_zbee_zcl_attr_status) !=
+            ZBEE_ZCL_STAT_SUCCESS ) {
+            expert_add_info(pinfo, tree->last_child, &ei_cfg_rpt_rsp_short_non_success);
+        }
+    }
+
+    while ( *offset < tvb_len && i < ZBEE_ZCL_NUM_ATTR_ETT ) {
         /* Create subtree for attribute status field */
         sub_tree = proto_tree_add_subtree(tree, tvb, *offset, 3, ett_zbee_zcl_attr[i], NULL, "Attribute Status Record");
         i++;
 
         /* Dissect the status */
-        if ( dissect_zcl_attr_uint8(tvb, sub_tree, offset, &hf_zbee_zcl_attr_status) !=
-            ZBEE_ZCL_STAT_SUCCESS ) {
-                /* Dissect the direction on error */
-                dissect_zcl_attr_uint8(tvb, sub_tree, offset, &hf_zbee_zcl_attr_dir);
-
-                /* Dissect the attribute identifier on error */
-                dissect_zcl_attr_id(tvb, sub_tree, offset, cluster_id);
-        }
+        dissect_zcl_attr_uint8(tvb, sub_tree, offset, &hf_zbee_zcl_attr_status);
+        /* Dissect the direction */
+        dissect_zcl_attr_uint8(tvb, sub_tree, offset, &hf_zbee_zcl_attr_dir);
+        /* Dissect the attribute identifier */
+        dissect_zcl_attr_id(tvb, sub_tree, offset, cluster_id);
     }
 } /* dissect_zcl_config_report_resp */
 
@@ -2273,11 +2282,22 @@ void proto_register_zbee_zcl(void)
         ett[j] = &ett_zbee_zcl_array_elements[i];
     }
 
+    static ei_register_info ei[] = {
+        { &ei_cfg_rpt_rsp_short_non_success,
+          { "zbee_zcl.cfg_rpt_rsp_short_non_success", PI_PROTOCOL, PI_WARN,
+            "Non-success response without full status records", EXPFILL }},
+    };
+
+    expert_module_t *expert_zbee_zcl;
+
     /* Register ZigBee ZCL protocol with Wireshark. */
     proto_zbee_zcl = proto_register_protocol("ZigBee Cluster Library", "ZigBee ZCL", "zbee_zcl");
     proto_register_field_array(proto_zbee_zcl, hf, array_length(hf));
     proto_register_subtree_array(ett, array_length(ett));
 
+    expert_zbee_zcl = expert_register_protocol(proto_zbee_zcl);
+    expert_register_field_array(expert_zbee_zcl, ei, array_length(ei));
+
     /* Register the ZCL dissector and subdissector list. */
     zbee_zcl_dissector_table = register_dissector_table("zbee.zcl.cluster", "ZigBee ZCL Cluster ID", proto_zbee_zcl, FT_UINT16, BASE_HEX);
     register_dissector(ZBEE_PROTOABBREV_ZCL, dissect_zbee_zcl, proto_zbee_zcl);