epan/dissectors/packet-diffserv-mpls-common.c

   1 /* packet-diffserv-mpls-common.c
   2  * Routines for the common part of Diffserv MPLS signaling protocols
   3  * Author: Endoh Akira (endoh@netmarks.co.jp)
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 /*
  27  * This module defines routines only for the common part of LDP
  28  * and RSVP to support for Diffserv MPLS as described in RFC 3270
  29  * and RFC 3140. Protocol specific routines of each signaling
  30  * protocol are defined in each dissector.
  31  */
  32
  33 #include "config.h"
  34
  35 #include <glib.h>
  36 #include <epan/packet.h>
  37 #include "packet-diffserv-mpls-common.h"
  38
  39 #define hf_map         *hfindexes[0]
  40 #define hf_exp         *hfindexes[1]
  41 #define hf_phbid       *hfindexes[2]
  42 #define hf_phbid_dscp  *hfindexes[3]
  43 #define hf_phbid_code  *hfindexes[4]
  44 #define hf_phbid_bit14 *hfindexes[5]
  45 #define hf_phbid_bit15 *hfindexes[6]
  46 #define ett_map        *etts[0]
  47 #define ett_map_phbid  *etts[1]
  48
  49 const value_string phbid_bit14_vals[] = {
  50     {0, "Single PHB"},
  51     {1, "Set of PHBs"},
  52     {0, NULL}
  53 };
  54
  55 const value_string phbid_bit15_vals[] = {
  56     {0, "PHBs defined by standards action"},
  57     {1, "PHBs not defined by standards action"},
  58     {0, NULL}
  59 };
  60
  61 void
  62 dissect_diffserv_mpls_common(tvbuff_t *tvb, proto_tree *tree, int type,
  63                              int offset, int **hfindexes, gint **etts)
  64 {
  65     proto_item  *ti = NULL, *sub_ti;
  66     proto_tree  *tree2 = NULL, *phbid_subtree;
  67     int exp;
  68     guint16 phbid;
  69
  70     switch (type) {
  71     case 1:  /* E-LSP */
  72         ti = proto_tree_add_item(tree, hf_map, tvb, offset, 4, ENC_NA);
  73         tree2 = proto_item_add_subtree(ti, ett_map);
  74         proto_item_set_text(ti, "MAP: ");
  75         offset ++;
  76         exp = tvb_get_guint8(tvb, offset) & 7;
  77         proto_tree_add_uint(tree2, hf_exp, tvb, offset, 1, exp);
  78         proto_item_append_text(ti, "EXP %u, ", exp);
  79         offset ++;
  80         break;
  81     case 2:  /* L-LSP */
  82         tree2 = tree;
  83         break;
  84     default:
  85         return;
  86     }
  87
  88     /* PHBID subtree */
  89     sub_ti = proto_tree_add_item(tree2, hf_phbid, tvb, offset, 2, ENC_NA);
  90     phbid_subtree = proto_item_add_subtree(sub_ti, ett_map_phbid);
  91     proto_item_set_text(sub_ti, "%s: ", (type == 1) ? PHBID_DESCRIPTION : "PSC");
  92     phbid = tvb_get_ntohs(tvb, offset);
  93
  94     if ((phbid & 1) == 0) {
  95         /* Case 1 of RFC 3140 */
  96         proto_tree_add_uint(phbid_subtree, hf_phbid_dscp,
  97                             tvb, offset, 2, phbid);
  98         if (type == 1)
  99             proto_item_append_text(ti, "DSCP %u", phbid >> 10);
 100         proto_item_append_text(sub_ti, "DSCP %u", phbid >> 10);
 101     }
 102     else {
 103         /* Case 2 of RFC 3140 */
 104         proto_tree_add_uint(phbid_subtree, hf_phbid_code,
 105                             tvb, offset, 2, phbid);
 106         if (type == 1)
 107             proto_item_append_text(ti, "PHB id code %u", phbid >> 4);
 108         proto_item_append_text(sub_ti, "PHB id code %u", phbid >> 4);
 109     }
 110     proto_tree_add_uint(phbid_subtree, hf_phbid_bit14, tvb, offset, 2, phbid);
 111     proto_tree_add_uint(phbid_subtree, hf_phbid_bit15, tvb, offset, 2, phbid);
 112 }