Use "proto_tree_add_item()" whenever possible; this fixes some bugs
[obnox/wireshark/wip.git] / packet-cdp.c
index a5f73463e2e4e245eff60fcd0b3e853d80c99fb7..51e1e4de6c1b9d79ae734400069831bb57f89617 100644 (file)
@@ -2,13 +2,12 @@
  * Routines for the disassembly of the "Cisco Discovery Protocol"
  * (c) Copyright Hannes R. Boehm <hannes@boehm.org>
  *
- * $Id: packet-cdp.c,v 1.18 2000/01/13 00:41:09 guy Exp $
+ * $Id: packet-cdp.c,v 1.42 2001/12/10 00:25:26 guy Exp $
  *
  * Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@zing.org>
+ * By Gerald Combs <gerald@ethereal.com>
  * Copyright 1998 Gerald Combs
  * 
- * 
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version 2
@@ -35,6 +34,7 @@
 
 #include <glib.h>
 #include "packet.h"
+#include "strutil.h"
 #include "nlpid.h"
 
 /*
@@ -51,7 +51,7 @@
 
 static int proto_cdp = -1;
 static int hf_cdp_version = -1;
-static int hf_cdp_flags = -1;
+static int hf_cdp_checksum = -1;
 static int hf_cdp_ttl = -1;
 static int hf_cdp_tlvtype = -1;
 static int hf_cdp_tlvlength = -1;
@@ -61,13 +61,15 @@ static gint ett_cdp_tlv = -1;
 static gint ett_cdp_address = -1;
 static gint ett_cdp_capabilities = -1;
 
+static dissector_handle_t data_handle;
+
 static int
-dissect_address_tlv(const u_char *pd, int offset, int length, proto_tree *tree);
+dissect_address_tlv(tvbuff_t *tvb, int offset, int length, proto_tree *tree);
 static void
-dissect_capabilities(const u_char *pd, int offset, int length, proto_tree *tree);
+dissect_capabilities(tvbuff_t *tvb, int offset, int length, proto_tree *tree);
 static void
-add_multi_line_string_to_tree(proto_tree *tree, gint start, gint len,
-  const gchar *prefix, const gchar *string);
+add_multi_line_string_to_tree(proto_tree *tree, tvbuff_t *tvb, gint start,
+  gint len, const gchar *prefix);
 
 #define TYPE_DEVICE_ID         0x0001
 #define TYPE_ADDRESS           0x0002
@@ -75,203 +77,287 @@ add_multi_line_string_to_tree(proto_tree *tree, gint start, gint len,
 #define TYPE_CAPABILITIES      0x0004
 #define TYPE_IOS_VERSION       0x0005
 #define TYPE_PLATFORM          0x0006
+#define TYPE_IP_PREFIX         0x0007
+
+#define TYPE_VTP_MGMT_DOMAIN    0x0009 /* Guessed, from tcpdump */
+#define TYPE_NATIVE_VLAN        0x000a /* Guessed, from tcpdump */
+#define TYPE_DUPLEX             0x000b /* Guessed, from tcpdump */
 
 static const value_string type_vals[] = {
-       { TYPE_DEVICE_ID,    "Device ID" },
-       { TYPE_ADDRESS,      "Addresses" },
-       { TYPE_PORT_ID,      "Port ID" },
-       { TYPE_CAPABILITIES, "Capabilities" },
-       { TYPE_IOS_VERSION,  "Software version" },
-       { TYPE_PLATFORM,     "Platform" },
-       { 0,                 NULL },
+       { TYPE_DEVICE_ID,       "Device ID" },
+       { TYPE_ADDRESS,         "Addresses" },
+       { TYPE_PORT_ID,         "Port ID" },
+       { TYPE_CAPABILITIES,    "Capabilities" },
+       { TYPE_IOS_VERSION,     "Software version" },
+       { TYPE_PLATFORM,        "Platform" },
+       { TYPE_IP_PREFIX,       "IP Prefix (used for ODR)" },
+       { TYPE_VTP_MGMT_DOMAIN, "VTP Management Domain" },
+       { TYPE_NATIVE_VLAN,     "Native VLAN" },
+       { TYPE_DUPLEX,          "Duplex" },
+       { 0,                    NULL },
 };
        
-void 
-dissect_cdp(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
+static void 
+dissect_cdp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
     proto_item *ti; 
     proto_tree *cdp_tree = NULL;
+    int offset = 0;
     guint16 type;
     guint16 length;
-    char *type_str;
-    char *stringmem;
     proto_item *tlvi;
     proto_tree *tlv_tree;
     int real_length;
     guint32 naddresses;
     int addr_length;
 
-    if (check_col(fd, COL_PROTOCOL))
-        col_add_str(fd, COL_PROTOCOL, "CDP");
-    if (check_col(fd, COL_INFO))
-        col_add_str(fd, COL_INFO, "Cisco Discovery Protocol"); 
+    if (check_col(pinfo->cinfo, COL_PROTOCOL))
+        col_set_str(pinfo->cinfo, COL_PROTOCOL, "CDP");
+    if (check_col(pinfo->cinfo, COL_INFO))
+        col_set_str(pinfo->cinfo, COL_INFO, "Cisco Discovery Protocol"); 
 
-    if(tree){
-        ti = proto_tree_add_item(tree, proto_cdp, offset, END_OF_FRAME, NULL);
+    if (tree){
+        ti = proto_tree_add_item(tree, proto_cdp, tvb, offset,
+                                tvb_length_remaining(tvb, offset), FALSE);
        cdp_tree = proto_item_add_subtree(ti, ett_cdp);
        
        /* CDP header */
-       proto_tree_add_item(cdp_tree, hf_cdp_version, offset, 1, pd[offset]);
+       proto_tree_add_item(cdp_tree, hf_cdp_version, tvb, offset, 1, FALSE);
        offset += 1;
-       proto_tree_add_item_format(cdp_tree, hf_cdp_ttl, offset, 1,
-                                  pntohs(&pd[offset]),
-                                  "TTL: %u seconds", pd[offset]);
+       proto_tree_add_uint_format(cdp_tree, hf_cdp_ttl, tvb, offset, 1,
+                                  tvb_get_guint8(tvb, offset),
+                                  "TTL: %u seconds",
+                                  tvb_get_guint8(tvb, offset));
        offset += 1;
-       proto_tree_add_item_format(cdp_tree, hf_cdp_flags, offset, 2,
-                                  pd[offset], 
-                                  "Checksum: 0x%04x", pntohs(&pd[offset]));
+       proto_tree_add_item(cdp_tree, hf_cdp_checksum, tvb, offset, 2, FALSE);
        offset += 2;
 
-       while( IS_DATA_IN_FRAME(offset) ){
-               type = pntohs(&pd[offset + TLV_TYPE]);
-               length = pntohs(&pd[offset + TLV_LENGTH]);
-               type_str = val_to_str(type, type_vals,
-                   "Unknown (0x%04x)");
-
-               switch( type ){
-                       case TYPE_DEVICE_ID:
-                               /* Device ID */
-                               tlvi = proto_tree_add_text(cdp_tree, offset,
-                                   length, "Device ID: %s",
-                                   &pd[offset+4]);
-                               tlv_tree = proto_item_add_subtree(tlvi,
-                                   ett_cdp_tlv);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvtype,
-                                   offset + TLV_TYPE, 2, type);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvlength,
-                                   offset + TLV_LENGTH, 2, length);
-                               proto_tree_add_text(tlv_tree, offset + 4,
-                                   length - 4, "Device ID: %s",
-                                   &pd[offset+4]);
-                               offset+=length;
-                               break;
-                       case TYPE_ADDRESS:
-                               /* Addresses */
-                               tlvi = proto_tree_add_text(cdp_tree, offset,
-                                   4, "Address",
-                                   type, length);
-                               tlv_tree = proto_item_add_subtree(tlvi,
-                                   ett_cdp_tlv);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvtype,
-                                   offset + TLV_TYPE, 2, type);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvlength,
-                                   offset + TLV_LENGTH, 2, length);
-                               offset += 4;
-                               length -= 4;
-                               naddresses = pntohl(&pd[offset]);
-                               proto_tree_add_text(tlv_tree, offset, 4,
-                                   "Number of addresses: %u", naddresses);
-                               offset += 4;
-                               length -= 4;
-                               while (naddresses != 0) {
-                                   addr_length = dissect_address_tlv(pd,
-                                       offset, length, tlv_tree);
-                                   if (addr_length < 0)
-                                       break;
-                                   offset += addr_length;
-                                   length -= addr_length;
-
-                                   naddresses--;
-                               }
-                               offset += length;
-                               break;
-                       case TYPE_PORT_ID:
-                               real_length = length;
-                               if (pd[offset + real_length] != 0x00) {
-                                   /* The length in the TLV doesn't
-                                      appear to be the length of the
-                                      TLV, as the byte just past it
-                                      isn't the first byte of a 2-byte
-                                      big-endian small integer; make
-                                      the length of the TLV the length
-                                      in the TLV, plus 4 bytes for the
-                                      TLV type and length, minus 1
-                                      because that's what makes one
-                                      capture work. */
-                                   real_length = length + 3;
-                               }
-                               tlvi = proto_tree_add_text(cdp_tree, offset,
-                                   real_length, "Port ID: %s",
-                                   &pd[offset+4]);
-                               tlv_tree = proto_item_add_subtree(tlvi,
-                                   ett_cdp_tlv);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvtype,
-                                   offset + TLV_TYPE, 2, type);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvlength,
-                                   offset + TLV_LENGTH, 2, length);
-                               proto_tree_add_text(tlv_tree, offset + 4,
-                                   real_length - 4,
-                                   "Sent through Interface: %s",
-                                   &pd[offset+4]);
-                               offset += real_length;
-                               break;
-                       case TYPE_CAPABILITIES:
-                               tlvi = proto_tree_add_text(cdp_tree, offset,
-                                   length, "Capabilities");
-                               tlv_tree = proto_item_add_subtree(tlvi,
-                                   ett_cdp_tlv);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvtype,
-                                   offset + TLV_TYPE, 2, type);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvlength,
-                                   offset + TLV_LENGTH, 2, length);
-                               offset += 4;
-                               length -= 4;
-                               dissect_capabilities(pd, offset, length,
-                                   tlv_tree);
-                               offset += length;
-                               break;
-                       case TYPE_IOS_VERSION:
-                               tlvi = proto_tree_add_text(cdp_tree, offset,
-                                   length, "Software Version");
-                               tlv_tree = proto_item_add_subtree(tlvi,
-                                   ett_cdp_tlv);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvtype,
-                                   offset + TLV_TYPE, 2, type);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvlength,
-                                   offset + TLV_LENGTH, 2, length);
-                               add_multi_line_string_to_tree(tlv_tree,
-                                   offset + 4, length - 4, "Software Version: ",
-                                   &pd[offset+4] );
-                               offset += length;
-                               break;
-                       case TYPE_PLATFORM:
-                               /* ??? platform */
-                               stringmem = malloc(length);
-                               memset(stringmem, '\0', length);
-                               memcpy(stringmem, &pd[offset+4], length - 4 );
-                               tlvi = proto_tree_add_text(cdp_tree,
-                                   offset, length, "Platform: %s",
-                                   stringmem);
-                               tlv_tree = proto_item_add_subtree(tlvi,
-                                   ett_cdp_tlv);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvtype,
-                                   offset + TLV_TYPE, 2, type);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvlength,
-                                   offset + TLV_LENGTH, 2, length);
-                               proto_tree_add_text(tlv_tree, offset + 4,
-                                   length - 4, "Platform: %s", stringmem);
-                               free(stringmem);
-                               offset+=length;
-                               break;
-                       default:
-                               tlvi = proto_tree_add_text(cdp_tree, offset,
-                                   length, "Type: %s, length: %u",
-                                   type_str, length);
-                               tlv_tree = proto_item_add_subtree(tlvi,
-                                   ett_cdp_tlv);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvtype,
-                                   offset + TLV_TYPE, 2, type);
-                               proto_tree_add_item(tlv_tree, hf_cdp_tlvlength,
-                                   offset + TLV_LENGTH, 2, length);
-                               if (length > 4) {
-                                       proto_tree_add_text(tlv_tree,
-                                           offset + 4, length - 4, "Data");
-                               } else
-                                       return;
-                               offset+=length;
+       while (tvb_reported_length_remaining(tvb, offset) != 0) {
+           type = tvb_get_ntohs(tvb, offset + TLV_TYPE);
+           length = tvb_get_ntohs(tvb, offset + TLV_LENGTH);
+           if (length < 4) {
+               tlvi = proto_tree_add_text(cdp_tree, tvb, offset, 4,
+                   "TLV with invalid length %u (< 4)",
+                   length);
+               tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
+                           offset + TLV_TYPE, 2, type);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
+                           offset + TLV_LENGTH, 2, length);
+               offset += 4;
+               break;
+           }
+
+           switch (type) {
+
+           case TYPE_DEVICE_ID:
+               /* Device ID */
+               tlvi = proto_tree_add_text(cdp_tree, tvb, offset,
+                           length, "Device ID: %.*s",
+                           length - 4,
+                           tvb_get_ptr(tvb, offset + 4, length - 4));
+               tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
+                           offset + TLV_TYPE, 2, type);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
+                           offset + TLV_LENGTH, 2, length);
+               proto_tree_add_text(tlv_tree, tvb, offset + 4,
+                           length - 4, "Device ID: %.*s",
+                           length - 4,
+                           tvb_get_ptr(tvb, offset + 4, length - 4));
+               offset += length;
+               break;
+
+           case TYPE_ADDRESS:
+               /* Addresses */
+               tlvi = proto_tree_add_text(cdp_tree, tvb, offset,
+                           length, "Addresses");
+               tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
+                           offset + TLV_TYPE, 2, type);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
+                           offset + TLV_LENGTH, 2, length);
+               offset += 4;
+               length -= 4;
+               naddresses = tvb_get_ntohl(tvb, offset);
+               proto_tree_add_text(tlv_tree, tvb, offset, 4,
+                           "Number of addresses: %u", naddresses);
+               offset += 4;
+               length -= 4;
+               while (naddresses != 0) {
+                   addr_length = dissect_address_tlv(tvb, offset, length,
+                               tlv_tree);
+                   if (addr_length < 0)
+                       break;
+                   offset += addr_length;
+                   length -= addr_length;
+
+                   naddresses--;
                }
+               offset += length;
+               break;
+
+           case TYPE_PORT_ID:
+               real_length = length;
+               if (tvb_get_guint8(tvb, offset + real_length) != 0x00) {
+                   /* The length in the TLV doesn't appear to be the
+                      length of the TLV, as the byte just past it
+                      isn't the first byte of a 2-byte big-endian
+                      small integer; make the length of the TLV the length
+                      in the TLV, plus 4 bytes for the TLV type and length,
+                      minus 1 because that's what makes one capture work. */
+                   real_length = length + 3;
+               }
+               tlvi = proto_tree_add_text(cdp_tree, tvb, offset,
+                           real_length, "Port ID: %.*s",
+                           real_length - 4,
+                           tvb_get_ptr(tvb, offset + 4, real_length - 4));
+               tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
+                           offset + TLV_TYPE, 2, type);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
+                           offset + TLV_LENGTH, 2, length);
+               proto_tree_add_text(tlv_tree, tvb, offset + 4,
+                           real_length - 4,
+                           "Sent through Interface: %.*s",
+                           real_length - 4,
+                           tvb_get_ptr(tvb, offset + 4, real_length - 4));
+               offset += real_length;
+               break;
+
+           case TYPE_CAPABILITIES:
+               tlvi = proto_tree_add_text(cdp_tree, tvb, offset,
+                           length, "Capabilities");
+               tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
+                           offset + TLV_TYPE, 2, type);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
+                           offset + TLV_LENGTH, 2, length);
+               offset += 4;
+               length -= 4;
+               dissect_capabilities(tvb, offset, length, tlv_tree);
+               offset += length;
+               break;
+
+           case TYPE_IOS_VERSION:
+               tlvi = proto_tree_add_text(cdp_tree, tvb, offset,
+                           length, "Software Version");
+               tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
+                           offset + TLV_TYPE, 2, type);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
+                           offset + TLV_LENGTH, 2, length);
+               add_multi_line_string_to_tree(tlv_tree, tvb, offset + 4,
+                               length - 4, "Software Version: ");
+               offset += length;
+               break;
+
+           case TYPE_PLATFORM:
+               /* ??? platform */
+               tlvi = proto_tree_add_text(cdp_tree, tvb,
+                           offset, length, "Platform: %.*s",
+                           length - 4,
+                           tvb_get_ptr(tvb, offset + 4, length - 4));
+               tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
+                           offset + TLV_TYPE, 2, type);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
+                           offset + TLV_LENGTH, 2, length);
+               proto_tree_add_text(tlv_tree, tvb, offset + 4,
+                           length - 4, "Platform: %.*s",
+                           length - 4,
+                           tvb_get_ptr(tvb, offset + 4, length - 4));
+               offset += length;
+               break;
+            case TYPE_IP_PREFIX:
+               tlvi = proto_tree_add_text(cdp_tree, tvb, offset,
+                           length, "IP Prefixes: %d",length/5);
+
+                           /* the actual number of prefixes is (length-4)/5
+                           but if the variable is not a "float" but "integer"
+                           then length/5=(length-4)/5  :)  */
+                           
+               tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
+                           offset + TLV_TYPE, 2, type);  
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
+                           offset + TLV_LENGTH, 2, length);
+               offset += 4;
+               length -= 4;
+               while (length > 0) {
+                       proto_tree_add_text(tlv_tree, tvb, offset, 5,
+                               "IP Prefix = %s/%u",
+                               ip_to_str(tvb_get_ptr(tvb, offset, 4)),
+                               tvb_get_guint8(tvb,offset+4));
+                       offset += 5;
+                       length -= 5;
+               }
+               break;
+           case TYPE_VTP_MGMT_DOMAIN:
+               tlvi = proto_tree_add_text(cdp_tree, tvb,
+                           offset, length, "VTP Management Domain: %.*s",
+                           length - 4,
+                           tvb_get_ptr(tvb, offset + 4, length - 4));
+               tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
+                           offset + TLV_TYPE, 2, type);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
+                           offset + TLV_LENGTH, 2, length);
+               proto_tree_add_text(tlv_tree, tvb, offset + 4,
+                           length - 4, "VTP Management Domain: %.*s",
+                           length - 4,
+                           tvb_get_ptr(tvb, offset + 4, length - 4));
+               offset += length;
+               break;
+           case TYPE_NATIVE_VLAN:
+               tlvi = proto_tree_add_text(cdp_tree, tvb,
+                           offset, length, "Native VLAN: %u",
+                                          tvb_get_ntohs(tvb, offset + 4));
+               tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
+                           offset + TLV_TYPE, 2, type);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
+                           offset + TLV_LENGTH, 2, length);
+               proto_tree_add_text(tlv_tree, tvb, offset + 4,
+                           length - 4, "Native VLAN: %u",
+                                   tvb_get_ntohs(tvb, offset + 4));
+               offset += length;
+               break;
+           case TYPE_DUPLEX:
+               tlvi = proto_tree_add_text(cdp_tree, tvb,
+                           offset, length, "Duplex: %s",
+                                          tvb_get_guint8(tvb, offset + 4) ?
+                                          "Full" : "Half" );
+               tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
+                           offset + TLV_TYPE, 2, type);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
+                           offset + TLV_LENGTH, 2, length);
+               proto_tree_add_text(tlv_tree, tvb, offset + 4,
+                           length - 4, "Duplex: %s",
+                                   tvb_get_guint8(tvb, offset + 4) ?
+                                   "Full" : "Half" );
+               offset += length;
+               break;
+           default:
+               tlvi = proto_tree_add_text(cdp_tree, tvb, offset,
+                           length, "Type: %s, length: %u",
+                           val_to_str(type, type_vals, "Unknown (0x%04x)"),
+                           length);
+               tlv_tree = proto_item_add_subtree(tlvi, ett_cdp_tlv);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvtype, tvb,
+                           offset + TLV_TYPE, 2, type);
+               proto_tree_add_uint(tlv_tree, hf_cdp_tlvlength, tvb,
+                           offset + TLV_LENGTH, 2, length);
+               if (length > 4) {
+                       proto_tree_add_text(tlv_tree, tvb, offset + 4,
+                                       length - 4, "Data");
+               } else
+                       return;
+               offset += length;
+           }
        }
-       dissect_data(pd, offset, fd, cdp_tree);
+       call_dissector(data_handle,tvb_new_subset(tvb, offset,-1,tvb_reported_length_remaining(tvb,offset)), pinfo, cdp_tree);
     }
 }
 
@@ -285,12 +371,13 @@ static const value_string proto_type_vals[] = {
 };
 
 static int
-dissect_address_tlv(const u_char *pd, int offset, int length, proto_tree *tree)
+dissect_address_tlv(tvbuff_t *tvb, int offset, int length, proto_tree *tree)
 {
     proto_item *ti;
     proto_tree *address_tree;
     guint8 protocol_type;
     guint8 protocol_length;
+    int nlpid;
     char *protocol_str;
     guint16 address_length;
     char *address_type_str;
@@ -298,93 +385,59 @@ dissect_address_tlv(const u_char *pd, int offset, int length, proto_tree *tree)
 
     if (length < 1)
         return -1;
-    protocol_type = pd[offset];
-    if (length < 2) {
-        ti = proto_tree_add_text(tree, offset, length, "Truncated address");
-       address_tree = proto_item_add_subtree(ti, ett_cdp_address);
-        proto_tree_add_text(address_tree, offset, 1, "Protocol type: %s",
-         val_to_str(protocol_type, proto_type_vals, "Unknown (0x%02x)"));
-       return -1;
-    }
-    protocol_length = pd[offset + 1];
-    if (length < 2 + protocol_length) {
-        ti = proto_tree_add_text(tree, offset, length, "Truncated address");
-       address_tree = proto_item_add_subtree(ti, ett_cdp_address);
-        proto_tree_add_text(address_tree, offset, 1, "Protocol type: %s",
-         val_to_str(protocol_type, proto_type_vals, "Unknown (0x%02x)"));
-       offset += 1;
-        proto_tree_add_text(address_tree, offset, 1, "Protocol length: %u",
-          protocol_length);
+    ti = proto_tree_add_text(tree, tvb, offset, length, "Truncated address");
+    address_tree = proto_item_add_subtree(ti, ett_cdp_address);
+    protocol_type = tvb_get_guint8(tvb, offset);
+    proto_tree_add_text(address_tree, tvb, offset, 1, "Protocol type: %s",
+       val_to_str(protocol_type, proto_type_vals, "Unknown (0x%02x)"));
+    offset += 1;
+    length -= 1;
+
+    if (length < 1)
        return -1;
-    }
+    protocol_length = tvb_get_guint8(tvb, offset);
+    proto_tree_add_text(address_tree, tvb, offset, 1, "Protocol length: %u",
+                       protocol_length);
+    offset += 1;
+    length -= 1;
 
-    if (length < 2 + protocol_length) {
-        ti = proto_tree_add_text(tree, offset, length, "Truncated address");
-       address_tree = proto_item_add_subtree(ti, ett_cdp_address);
-        proto_tree_add_text(address_tree, offset, 1, "Protocol type: %s",
-          val_to_str(protocol_type, proto_type_vals, "Unknown (0x%02x)"));
-        offset += 1;
-        length -= 1;
-        proto_tree_add_text(address_tree, offset, 1, "Protocol length: %u",
-          protocol_length);
-        offset += 1;
-        length -= 1;
+    if (length < protocol_length) {
         if (length != 0) {
-            proto_tree_add_text(address_tree, offset, length,
-              "Protocol: %s (truncated)", bytes_to_str(&pd[offset], length));
+            proto_tree_add_text(address_tree, tvb, offset, length,
+              "Protocol: %s (truncated)",
+              tvb_bytes_to_str(tvb, offset, length));
         }
        return -1;
     }
-
     protocol_str = NULL;
-    if (protocol_type == PROTO_TYPE_NLPID && protocol_length == 1)
-       protocol_str = val_to_str(pd[offset + 2], nlpid_vals, "Unknown (0x%02x)");
+    if (protocol_type == PROTO_TYPE_NLPID && protocol_length == 1) {
+       nlpid = tvb_get_guint8(tvb, offset);
+       protocol_str = val_to_str(nlpid, nlpid_vals, "Unknown (0x%02x)");
+    } else
+        nlpid = -1;
     if (protocol_str == NULL)
-        protocol_str = bytes_to_str(&pd[offset], protocol_length);
-
-    if (length < 2 + protocol_length + 2) {
-        ti = proto_tree_add_text(tree, offset, length, "Truncated address");
-       address_tree = proto_item_add_subtree(ti, ett_cdp_address);
-        proto_tree_add_text(address_tree, offset, 1, "Protocol type: %s",
-          val_to_str(protocol_type, proto_type_vals, "Unknown (0x%02x)"));
-        offset += 1;
-        length -= 1;
-        proto_tree_add_text(address_tree, offset, 1, "Protocol length: %u",
-          protocol_length);
-        offset += 1;
-        length -= 1;
-        proto_tree_add_text(address_tree, offset, protocol_length,
-          "Protocol: %s", protocol_str);
+        protocol_str = tvb_bytes_to_str(tvb, offset, protocol_length);
+    proto_tree_add_text(address_tree, tvb, offset, protocol_length,
+                       "Protocol: %s", protocol_str);
+    offset += protocol_length;
+    length -= protocol_length;
+
+    if (length < 2)
        return -1;
-    }
-    address_length = pntohs(&pd[offset + 2 + protocol_length]);
-
-    if (length < 2 + protocol_length + 2 + address_length) {
-        ti = proto_tree_add_text(tree, offset, length, "Truncated address");
-       address_tree = proto_item_add_subtree(ti, ett_cdp_address);
-        proto_tree_add_text(address_tree, offset, 1, "Protocol type: %s",
-          val_to_str(protocol_type, proto_type_vals, "Unknown (0x%02x)"));
-        offset += 1;
-        length -= 1;
-        proto_tree_add_text(address_tree, offset, 1, "Protocol length: %u",
-          protocol_length);
-        offset += 1;
-        length -= 1;
-        proto_tree_add_text(address_tree, offset, protocol_length,
-          "Protocol: %s", protocol_str);
-        offset += protocol_length;
-        length -= protocol_length;
-        proto_tree_add_text(address_tree, offset, 2, "Address length: %u",
-          address_length);
-        offset += 2;
-        length -= 2;
+    address_length = tvb_get_ntohs(tvb, offset);
+    proto_tree_add_text(address_tree, tvb, offset, 2, "Address length: %u",
+                       address_length);
+    offset += 2;
+    length -= 2;
+
+    if (length < address_length) {
         if (length != 0) {
-            proto_tree_add_text(address_tree, offset, length,
-              "Address: %s (truncated)", bytes_to_str(&pd[offset], length));
+            proto_tree_add_text(address_tree, tvb, offset, length,
+              "Address: %s (truncated)",
+              tvb_bytes_to_str(tvb, offset, length));
         }
        return -1;
     }
-
     /* XXX - the Cisco document seems to be saying that, for 802.2-format
        protocol types, 0xAAAA03 0x000000 0x0800 is IPv6, but 0x0800 is
        the Ethernet protocol type for IPv4. */
@@ -392,7 +445,7 @@ dissect_address_tlv(const u_char *pd, int offset, int length, proto_tree *tree)
     address_type_str = NULL;
     address_str = NULL;
     if (protocol_type == PROTO_TYPE_NLPID && protocol_length == 1) {
-        switch (pd[offset + 2]) {
+        switch (nlpid) {
 
         /* XXX - dissect NLPID_ISO8473_CLNP as OSI CLNP address? */
 
@@ -400,7 +453,7 @@ dissect_address_tlv(const u_char *pd, int offset, int length, proto_tree *tree)
             if (address_length == 4) {
                 /* The address is an IP address. */
                 address_type_str = "IP address";
-                address_str = ip_to_str(&pd[offset + 2 + protocol_length + 2]);
+                address_str = ip_to_str(tvb_get_ptr(tvb, offset, 4));
             }
             break;
         }
@@ -408,35 +461,16 @@ dissect_address_tlv(const u_char *pd, int offset, int length, proto_tree *tree)
     if (address_type_str == NULL)
         address_type_str = "Address";
     if (address_str == NULL) {
-        address_str = bytes_to_str(&pd[offset + 2 + protocol_length + 2],
-         address_length);
+        address_str = tvb_bytes_to_str(tvb, offset, address_length);
     }
-    ti = proto_tree_add_text(tree, offset, length, "%s: %s",
-      address_type_str, address_str);
-    address_tree = proto_item_add_subtree(ti, ett_cdp_address);
-    proto_tree_add_text(address_tree, offset, 1, "Protocol type: %s",
-      val_to_str(protocol_type, proto_type_vals, "Unknown (0x%02x)"));
-    offset += 1;
-    length -= 1;
-    proto_tree_add_text(address_tree, offset, 1, "Protocol length: %u",
-      protocol_length);
-    offset += 1;
-    length -= 1;
-    proto_tree_add_text(address_tree, offset, protocol_length,
-      "Protocol: %s", protocol_str);
-    offset += protocol_length;
-    length -= protocol_length;
-    proto_tree_add_text(address_tree, offset, 2, "Address length: %u",
-      address_length);
-    offset += 2;
-    length -= 2;
-    proto_tree_add_text(address_tree, offset, address_length, "%s: %s",
+    proto_item_set_text(ti, "%s: %s", address_type_str, address_str);
+    proto_tree_add_text(address_tree, tvb, offset, address_length, "%s: %s",
       address_type_str, address_str);
     return 2 + protocol_length + 2 + address_length;
 }
 
 static void
-dissect_capabilities(const u_char *pd, int offset, int length, proto_tree *tree)
+dissect_capabilities(tvbuff_t *tvb, int offset, int length, proto_tree *tree)
 {
     proto_item *ti;
     proto_tree *capabilities_tree;
@@ -444,48 +478,48 @@ dissect_capabilities(const u_char *pd, int offset, int length, proto_tree *tree)
 
     if (length < 4)
         return;
-    capabilities = pntohl(&pd[offset]);
-    ti = proto_tree_add_text(tree, offset, length, "Capabilities: 0x%08x",
+    capabilities = tvb_get_ntohl(tvb, offset);
+    ti = proto_tree_add_text(tree, tvb, offset, length, "Capabilities: 0x%08x",
         capabilities);
     capabilities_tree = proto_item_add_subtree(ti, ett_cdp_capabilities);
-    proto_tree_add_text(capabilities_tree, offset, 4,
+    proto_tree_add_text(capabilities_tree, tvb, offset, 4,
        decode_boolean_bitfield(capabilities, 0x01, 4*8,
            "Performs level 3 routing",
            "Doesn't perform level 3 routing"));
-    proto_tree_add_text(capabilities_tree, offset, 4,
+    proto_tree_add_text(capabilities_tree, tvb, offset, 4,
        decode_boolean_bitfield(capabilities, 0x02, 4*8,
            "Performs level 2 transparent bridging",
            "Doesn't perform level 2 transparent bridging"));
-    proto_tree_add_text(capabilities_tree, offset, 4,
+    proto_tree_add_text(capabilities_tree, tvb, offset, 4,
        decode_boolean_bitfield(capabilities, 0x04, 4*8,
            "Performs level 2 source-route bridging",
            "Doesn't perform level 2 source-route bridging"));
-    proto_tree_add_text(capabilities_tree, offset, 4,
+    proto_tree_add_text(capabilities_tree, tvb, offset, 4,
        decode_boolean_bitfield(capabilities, 0x08, 4*8,
            "Performs level 2 switching",
            "Doesn't perform level 2 switching"));
-    proto_tree_add_text(capabilities_tree, offset, 4,
+    proto_tree_add_text(capabilities_tree, tvb, offset, 4,
        decode_boolean_bitfield(capabilities, 0x10, 4*8,
            "Sends and receives packets for network-layer protocols",
            "Doesn't send or receive packets for network-layer protocols"));
-    proto_tree_add_text(capabilities_tree, offset, 4,
+    proto_tree_add_text(capabilities_tree, tvb, offset, 4,
        decode_boolean_bitfield(capabilities, 0x20, 4*8,
            "Doesn't forward IGMP Report packets on nonrouter ports",
            "Forwards IGMP Report packets on nonrouter ports"));
-    proto_tree_add_text(capabilities_tree, offset, 4,
+    proto_tree_add_text(capabilities_tree, tvb, offset, 4,
        decode_boolean_bitfield(capabilities, 0x40, 4*8,
            "Provides level 1 functionality",
            "Doesn't provide level 1 functionality"));
 }
 
 static void
-add_multi_line_string_to_tree(proto_tree *tree, gint start, gint len,
-  const gchar *prefix, const gchar *string)
+add_multi_line_string_to_tree(proto_tree *tree, tvbuff_t *tvb, gint start,
+  gint len, const gchar *prefix)
 {
     int prefix_len;
     int i;
     char blanks[64+1];
-    const gchar *p, *q;
+    gint next;
     int line_len;
     int data_len;
 
@@ -495,22 +529,13 @@ add_multi_line_string_to_tree(proto_tree *tree, gint start, gint len,
     for (i = 0; i < prefix_len; i++)
        blanks[i] = ' ';
     blanks[i] = '\0';
-    p = string;
-    for (;;) {
-       q = strchr(p, '\n');
-       if (q != NULL) {
-           line_len = q - p;
-           data_len = line_len + 1;
-       } else {
-           line_len = strlen(p);
-           data_len = line_len;
-       }
-       proto_tree_add_text(tree, start, data_len, "%s%.*s", prefix,
-          line_len, p);
-       if (q == NULL)
-           break;
-       p += data_len;
+    while (len > 0) {
+       line_len = tvb_find_line_end(tvb, start, len, &next);
+       data_len = next - start;
+       proto_tree_add_text(tree, tvb, start, data_len, "%s%.*s", prefix,
+          line_len, tvb_get_ptr(tvb, start, line_len));
        start += data_len;
+       len -= data_len;
        prefix = blanks;
     }
 }
@@ -518,35 +543,47 @@ add_multi_line_string_to_tree(proto_tree *tree, gint start, gint len,
 void
 proto_register_cdp(void)
 {
-        static hf_register_info hf[] = {
-                { &hf_cdp_version,
-                { "Version",           "cdp.version",  FT_UINT8, BASE_DEC, NULL, 0x0,
-                       "" }},
-
-                { &hf_cdp_flags,
-                { "Flags",             "cdp.flags", FT_UINT8, BASE_HEX, NULL, 0x0,
-                       "" }},
-
-                { &hf_cdp_ttl,
-                { "TTL",               "cdp.ttl", FT_UINT16, BASE_DEC, NULL, 0x0,
-                       "" }},
-
-                { &hf_cdp_tlvtype,
-                { "Type",              "cdp.tlv.type", FT_UINT16, BASE_HEX, VALS(type_vals), 0x0,
-                       "" }},
-
-                { &hf_cdp_tlvlength,
-                { "Length",            "cdp.tlv.len", FT_UINT16, BASE_DEC, NULL, 0x0,
-                       "" }},
-        };
-       static gint *ett[] = {
-               &ett_cdp,
-               &ett_cdp_tlv,
-               &ett_cdp_address,
-               &ett_cdp_capabilities,
-       };
-
-        proto_cdp = proto_register_protocol("Cisco Discovery Protocol", "cdp");
-        proto_register_field_array(proto_cdp, hf, array_length(hf));
-       proto_register_subtree_array(ett, array_length(ett));
+    static hf_register_info hf[] = {
+       { &hf_cdp_version,
+       { "Version",            "cdp.version",  FT_UINT8, BASE_DEC, NULL, 0x0,
+         "", HFILL }},
+
+       { &hf_cdp_ttl,
+       { "TTL",                "cdp.ttl", FT_UINT16, BASE_DEC, NULL, 0x0,
+         "", HFILL }},
+
+       { &hf_cdp_checksum,
+       { "Checksum",           "cdp.checksum", FT_UINT16, BASE_HEX, NULL, 0x0,
+         "", HFILL }},
+
+       { &hf_cdp_tlvtype,
+       { "Type",               "cdp.tlv.type", FT_UINT16, BASE_HEX, VALS(type_vals), 0x0,
+         "", HFILL }},
+
+       { &hf_cdp_tlvlength,
+       { "Length",             "cdp.tlv.len", FT_UINT16, BASE_DEC, NULL, 0x0,
+         "", HFILL }},
+    };
+    static gint *ett[] = {
+       &ett_cdp,
+       &ett_cdp_tlv,
+       &ett_cdp_address,
+       &ett_cdp_capabilities,
+    };
+
+    proto_cdp = proto_register_protocol("Cisco Discovery Protocol",
+                                       "CDP", "cdp");
+    proto_register_field_array(proto_cdp, hf, array_length(hf));
+    proto_register_subtree_array(ett, array_length(ett));
+}
+
+void
+proto_reg_handoff_cdp(void)
+{
+    dissector_handle_t cdp_handle;
+
+    data_handle = find_dissector("data");
+    cdp_handle = create_dissector_handle(dissect_cdp, proto_cdp);
+    dissector_add("llc.cisco_pid", 0x2000, cdp_handle);
+    dissector_add("chdlctype", 0x2000, cdp_handle);
 }