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  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-or-later
  10  */
  11
  12 /*
  13  * This module defines routines only for the common part of LDP
  14  * and RSVP to support for Diffserv MPLS as described in RFC 3270
  15  * and RFC 3140. Protocol specific routines of each signaling
  16  * protocol are defined in each dissector.
  17  */
  18
  19 #include "config.h"
  20
  21 #include <epan/packet.h>
  22 #include "packet-diffserv-mpls-common.h"
  23
  24 #define hf_map         *hfindexes[0]
  25 #define hf_exp         *hfindexes[1]
  26 #define hf_phbid       *hfindexes[2]
  27 #define hf_phbid_dscp  *hfindexes[3]
  28 #define hf_phbid_code  *hfindexes[4]
  29 #define hf_phbid_bit14 *hfindexes[5]
  30 #define hf_phbid_bit15 *hfindexes[6]
  31 #define ett_map        *etts[0]
  32 #define ett_map_phbid  *etts[1]
  33
  34 const value_string phbid_bit14_vals[] = {
  35     {0, "Single PHB"},
  36     {1, "Set of PHBs"},
  37     {0, NULL}
  38 };
  39
  40 const value_string phbid_bit15_vals[] = {
  41     {0, "PHBs defined by standards action"},
  42     {1, "PHBs not defined by standards action"},
  43     {0, NULL}
  44 };
  45
  46 void
  47 dissect_diffserv_mpls_common(tvbuff_t *tvb, proto_tree *tree, int type,
  48                              int offset, int **hfindexes, int **etts)
  49 {
  50     proto_item  *ti = NULL, *sub_ti;
  51     proto_tree  *tree2 = NULL, *phbid_subtree;
  52     int exp;
  53     uint16_t phbid;
  54
  55     switch (type) {
  56     case 1:  /* E-LSP */
  57         ti = proto_tree_add_item(tree, hf_map, tvb, offset, 4, ENC_NA);
  58         tree2 = proto_item_add_subtree(ti, ett_map);
  59         proto_item_set_text(ti, "MAP: ");
  60         offset ++;
  61         exp = tvb_get_uint8(tvb, offset) & 7;
  62         proto_tree_add_uint(tree2, hf_exp, tvb, offset, 1, exp);
  63         proto_item_append_text(ti, "EXP %u, ", exp);
  64         offset ++;
  65         break;
  66     case 2:  /* L-LSP */
  67         tree2 = tree;
  68         break;
  69     default:
  70         return;
  71     }
  72
  73     /* PHBID subtree */
  74     sub_ti = proto_tree_add_item(tree2, hf_phbid, tvb, offset, 2, ENC_NA);
  75     phbid_subtree = proto_item_add_subtree(sub_ti, ett_map_phbid);
  76     proto_item_set_text(sub_ti, "%s: ", (type == 1) ? PHBID_DESCRIPTION : "PSC");
  77     phbid = tvb_get_ntohs(tvb, offset);
  78
  79     if ((phbid & 1) == 0) {
  80         /* Case 1 of RFC 3140 */
  81         proto_tree_add_uint(phbid_subtree, hf_phbid_dscp,
  82                             tvb, offset, 2, phbid);
  83         if (type == 1)
  84             proto_item_append_text(ti, "DSCP %u", phbid >> 10);
  85         proto_item_append_text(sub_ti, "DSCP %u", phbid >> 10);
  86     }
  87     else {
  88         /* Case 2 of RFC 3140 */
  89         proto_tree_add_uint(phbid_subtree, hf_phbid_code,
  90                             tvb, offset, 2, phbid);
  91         if (type == 1)
  92             proto_item_append_text(ti, "PHB id code %u", phbid >> 4);
  93         proto_item_append_text(sub_ti, "PHB id code %u", phbid >> 4);
  94     }
  95     proto_tree_add_uint(phbid_subtree, hf_phbid_bit14, tvb, offset, 2, phbid);
  96     proto_tree_add_uint(phbid_subtree, hf_phbid_bit15, tvb, offset, 2, phbid);
  97 }
  98
  99 /*
 100  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 101  *
 102  * Local variables:
 103  * c-basic-offset: 4
 104  * tab-width: 8
 105  * indent-tabs-mode: nil
 106  * End:
 107  *
 108  * vi: set shiftwidth=4 tabstop=8 expandtab:
 109  * :indentSize=4:tabSize=8:noTabs=true:
 110  */