[docsis->rngrsp] Packet decoded in greater detail

Next steps would be to add expert and add missing TLVs.

Change-Id: Ia05d81c380d412ab02e55bbfc08363d9153ff1c3
Reviewed-on: https://code.wireshark.org/review/15617
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, 107 insertions, 101 deletions

diff --git a/plugins/docsis/packet-rngrsp.c b/plugins/docsis/packet-rngrsp.c
index 596efd0f9e..5bd142f689 100644
--- a/plugins/docsis/packet-rngrsp.c
+++ b/plugins/docsis/packet-rngrsp.c
@@ -39,6 +39,8 @@ void proto_reg_handoff_docsis_rngrsp(void);
 
 /* Initialize the protocol and registered fields */
 static int proto_docsis_rngrsp = -1;
+static int hf_docsis_rngrsp_type = -1;
+static int hf_docsis_rngrsp_length = -1;
 static int hf_docsis_rngrsp_upstream_chid = -1;
 static int hf_docsis_rngrsp_sid = -1;
 static int hf_docsis_rngrsp_timing_adj = -1;
@@ -58,6 +60,18 @@ static const value_string rng_stat_vals[] = {
 
 /* Initialize the subtree pointers */
 static gint ett_docsis_rngrsp = -1;
+static gint ett_docsis_rngrsptlv = -1;
+
+static const value_string rngrsp_tlv_vals[] = {
+  {RNGRSP_TIMING,            "Timing Adjust (6.25us/64)"},
+  {RNGRSP_PWR_LEVEL_ADJ,     "Power Level Adjust (0.25dB units)"},
+  {RNGRSP_OFFSET_FREQ_ADJ,   "Offset Freq Adjust (Hz)"},
+  {RNGRSP_TRANSMIT_EQ_ADJ,   "Transmit Equalisation Adjust"},
+  {RNGRSP_RANGING_STATUS,    "Ranging Status"},
+  {RNGRSP_DOWN_FREQ_OVER,    "Downstream Frequency Override (Hz)"},
+  {RNGRSP_UP_CHID_OVER,      "Upstream Channel ID Override"},
+  {0, NULL}
+};
 
 /* Code to actually dissect the packets */
 static int
@@ -65,13 +79,13 @@ dissect_rngrsp (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* da
 {
   proto_item *it;
   proto_tree *rngrsp_tree;
+  proto_item *rngrsptlv_item;
+  proto_tree *rngrsptlv_tree;
   guint8 tlvtype, tlvlen;
   int pos;
   gint length;
   guint8 upchid;
   guint16 sid;
-  gint8 pwr;
-  gint32 tim;
 
   sid = tvb_get_ntohs (tvb, 0);
   upchid = tvb_get_guint8 (tvb, 2);
@@ -83,121 +97,112 @@ dissect_rngrsp (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* da
   else
     col_add_fstr (pinfo->cinfo, COL_INFO,
                   "Ranging Response: SID = %u, Telephony Return", sid);
-
-
-  if (tree)
+  it = proto_tree_add_protocol_format (tree, proto_docsis_rngrsp, tvb, 0, -1,
+                                       "Ranging Response");
+  rngrsp_tree = proto_item_add_subtree (it, ett_docsis_rngrsp);
+  proto_tree_add_item (rngrsp_tree, hf_docsis_rngrsp_sid, tvb, 0, 2,
+                       ENC_BIG_ENDIAN);
+  proto_tree_add_item (rngrsp_tree, hf_docsis_rngrsp_upstream_chid, tvb,
+                       2, 1, ENC_BIG_ENDIAN);
+  length = tvb_reported_length (tvb);
+  pos = 3;
+  while (pos < length)
     {
-      it =
-        proto_tree_add_protocol_format (tree, proto_docsis_rngrsp, tvb, 0, -1,
-                                        "Ranging Response");
-      rngrsp_tree = proto_item_add_subtree (it, ett_docsis_rngrsp);
-      proto_tree_add_item (rngrsp_tree, hf_docsis_rngrsp_sid, tvb, 0, 2,
-                           ENC_BIG_ENDIAN);
-      proto_tree_add_item (rngrsp_tree, hf_docsis_rngrsp_upstream_chid, tvb,
-                           2, 1, ENC_BIG_ENDIAN);
-
-      length = tvb_reported_length_remaining (tvb, 0);
-      pos = 3;
-      while (pos < length)
+      tlvtype = tvb_get_guint8 (tvb, pos);
+      rngrsptlv_tree = proto_tree_add_subtree(rngrsp_tree, tvb, pos, -1,
+                                  ett_docsis_rngrsptlv, &rngrsptlv_item,
+                                  val_to_str(tlvtype, rngrsp_tlv_vals,
+                                  "Unknown TLV (%u)"));
+      proto_tree_add_uint (rngrsptlv_tree, hf_docsis_rngrsp_type,
+                          tvb, pos, 1, tlvtype);
+      pos++;
+      tlvlen = tvb_get_guint8 (tvb, pos);
+      proto_tree_add_uint (rngrsptlv_tree, hf_docsis_rngrsp_length,
+                           tvb, pos, 1, tlvlen);
+      pos++;
+      proto_item_set_len(rngrsptlv_item, tlvlen + 2);
+      switch (tlvtype)
         {
-          tlvtype = tvb_get_guint8 (tvb, pos++);
-          tlvlen = tvb_get_guint8 (tvb, pos++);
-          switch (tlvtype)
-            {
-              case RNGRSP_TIMING:
-                if (tlvlen == 4)
-                  {
-                    tim = tvb_get_ntohl (tvb, pos);
-                    proto_tree_add_int (rngrsp_tree,
-                                        hf_docsis_rngrsp_timing_adj, tvb, pos,
-                                        tlvlen, tim);
-                  }
-                else
-                  {
-                    THROW (ReportedBoundsError);
-                  }
-                break;
-              case RNGRSP_PWR_LEVEL_ADJ:
-                if (tlvlen == 1)
-                  {
-                    pwr = tvb_get_guint8 (tvb, pos);
-                    proto_tree_add_int (rngrsp_tree, hf_docsis_rngrsp_power_adj,
-                                        tvb, pos, tlvlen, pwr);
-                  }
-                else
-                  {
-                    THROW (ReportedBoundsError);
-                  }
-                break;
-              case RNGRSP_OFFSET_FREQ_ADJ:
-                if (tlvlen == 2)
-                  {
-                    proto_tree_add_item (rngrsp_tree, hf_docsis_rngrsp_freq_adj,
-                                         tvb, pos, tlvlen, ENC_BIG_ENDIAN);
-                  }
-                else
-                  {
-                    THROW (ReportedBoundsError);
-                  }
-                break;
-              case RNGRSP_TRANSMIT_EQ_ADJ:
-                proto_tree_add_item (rngrsp_tree, hf_docsis_rngrsp_xmit_eq_adj,
-                                     tvb, pos, tlvlen, ENC_NA);
-                break;
-              case RNGRSP_RANGING_STATUS:
-                if (tlvlen == 1)
-                  proto_tree_add_item (rngrsp_tree,
-                                       hf_docsis_rngrsp_ranging_status, tvb,
-                                       pos, tlvlen, ENC_BIG_ENDIAN);
-                else
-                  {
-                    THROW (ReportedBoundsError);
-                  }
-                break;
-              case RNGRSP_DOWN_FREQ_OVER:
-                if (tlvlen == 4)
-                  proto_tree_add_item (rngrsp_tree,
-                                       hf_docsis_rngrsp_down_freq_over, tvb,
-                                       pos, tlvlen, ENC_BIG_ENDIAN);
-                else
-                  {
-                    THROW (ReportedBoundsError);
-                  }
-                break;
-              case RNGRSP_UP_CHID_OVER:
-                if (tlvlen == 1)
-                  proto_tree_add_item (rngrsp_tree,
-                                       hf_docsis_rngrsp_upstream_ch_over, tvb,
-                                       pos, tlvlen, ENC_BIG_ENDIAN);
-                else
-                  {
-                    THROW (ReportedBoundsError);
-                  }
-                break;
-
-            }                   /* switch(tlvtype) */
-          pos = pos + tlvlen;
-        }                       /* while (pos < length) */
-    }                           /* if (tree) */
-    return tvb_captured_length(tvb);
+          case RNGRSP_TIMING:
+            if (tlvlen == 4)
+              {
+                proto_tree_add_item (rngrsptlv_tree,
+                                    hf_docsis_rngrsp_timing_adj, tvb, pos,
+                                    tlvlen, ENC_BIG_ENDIAN);
+              }
+            pos = pos + tlvlen;
+            break;
+          case RNGRSP_PWR_LEVEL_ADJ:
+            if (tlvlen == 1)
+              {
+                proto_tree_add_item (rngrsptlv_tree, hf_docsis_rngrsp_power_adj,
+                                    tvb, pos, tlvlen, ENC_NA);
+              }
+            pos = pos + tlvlen;
+            break;
+          case RNGRSP_OFFSET_FREQ_ADJ:
+            if (tlvlen == 2)
+              {
+                proto_tree_add_item (rngrsptlv_tree, hf_docsis_rngrsp_freq_adj,
+                                     tvb, pos, tlvlen, ENC_BIG_ENDIAN);
+              }
+            pos = pos + tlvlen;
+            break;
+          case RNGRSP_TRANSMIT_EQ_ADJ:
+            proto_tree_add_item (rngrsptlv_tree, hf_docsis_rngrsp_xmit_eq_adj,
+                                 tvb, pos, tlvlen, ENC_NA);
+            pos = pos + tlvlen;
+            break;
+          case RNGRSP_RANGING_STATUS:
+            if (tlvlen == 1)
+              proto_tree_add_item (rngrsptlv_tree,
+                                   hf_docsis_rngrsp_ranging_status, tvb,
+                                   pos, tlvlen, ENC_BIG_ENDIAN);
+            pos = pos + tlvlen;
+            break;
+          case RNGRSP_DOWN_FREQ_OVER:
+            if (tlvlen == 4)
+              proto_tree_add_item (rngrsptlv_tree,
+                                   hf_docsis_rngrsp_down_freq_over, tvb,
+                                   pos, tlvlen, ENC_BIG_ENDIAN);
+            pos = pos + tlvlen;
+            break;
+          case RNGRSP_UP_CHID_OVER:
+            if (tlvlen == 1)
+              proto_tree_add_item (rngrsptlv_tree,
+                                   hf_docsis_rngrsp_upstream_ch_over, tvb,
+                                   pos, tlvlen, ENC_BIG_ENDIAN);
+            pos = pos + tlvlen;
+            break;
+          default:
+            pos = pos + tlvlen;
+        }                   /* switch(tlvtype) */
+    }                       /* while (pos < length) */
+  return length;
 }
 
-
-
-
 /* Register the protocol with Wireshark */
 
 /* this format is require because a script is used to build the C function
    that calls all the protocol registration.
 */
 
-
 void
 proto_register_docsis_rngrsp (void)
 {
 
 /* Setup list of header fields  See Section 1.6.1 for details*/
   static hf_register_info hf[] = {
+    {&hf_docsis_rngrsp_type,
+     {"Type", "docsis_rngrsp.type",
+      FT_UINT8, BASE_DEC, VALS(rngrsp_tlv_vals), 0x0,
+      "TLV Type", HFILL}
+     },
+    {&hf_docsis_rngrsp_length,
+     {"Length", "docsis_rngrsp.length",
+      FT_UINT8, BASE_DEC, NULL, 0x0,
+      "TLV Length", HFILL}
+     },
     {&hf_docsis_rngrsp_sid,
      {"Service Identifier", "docsis_rngrsp.sid",
       FT_UINT16, BASE_DEC, NULL, 0x0,
@@ -249,6 +254,7 @@ proto_register_docsis_rngrsp (void)
 /* Setup protocol subtree array */
   static gint *ett[] = {
     &ett_docsis_rngrsp,
+    &ett_docsis_rngrsptlv,
   };
 
 /* Register the protocol name and description */