epan/dissectors/packet-pw-oam.c

   1 /* packet-pw-oam.c
   2 *
   3 * Routines for Pseudowire Status for static pseudowires : RFC 6478
   4 *
   5 * (c) Copyright 2012, Krishnamurthy Mayya <krishnamurthymayya@gmail.com>
   6 *                     Nikitha Malgi <nikitha01@gmail.com>
   7 *
   8 * $Id$
   9 *
  10 * Wireshark - Network traffic analyzer
  11 * By Gerald Combs <gerald@wireshark.org>
  12 * Copyright 1998 Gerald Combs
  13 *
  14 * This program is free software; you can redistribute it and/or
  15 * modify it under the terms of the GNU General Public License
  16 * as published by the Free Software Foundation; either version 2
  17 * of the License, or (at your option) any later version.
  18 *
  19 * This program is distributed in the hope that it will be useful,
  20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 * GNU General Public License for more details.
  23 *
  24 * You should have received a copy of the GNU General Public License
  25 * along with this program; if not, write to the Free Software
  26 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  27 */
  28
  29 #include "config.h"
  30 #include <glib.h>
  31 #include <epan/packet.h>
  32
  33 /* MPLS-TP FM protocol specific variables */
  34 static gint proto_pw_oam             = -1;
  35 static gint ett_pw_oam               = -1;
  36 static gint ett_pw_oam_flags         = -1;
  37 static gint ett_pw_oam_tlv_tree      = -1;
  38
  39 static int hf_pw_oam_tlv_reserved    = -1;
  40 static int hf_pw_oam_tlv_type        = -1;
  41 static int hf_pw_oam_total_tlv_len   = -1;
  42 static int hf_pw_oam_code            = -1;
  43 static int hf_pw_oam_flags           = -1;
  44 static int hf_pw_oam_flags_a         = -1;
  45 static int hf_pw_oam_refresh_timer   = -1;
  46 static int hf_pw_oam_tlv_len         = -1;
  47
  48 static const value_string pw_oam_code[] = {
  49   {0x00000002, "Local Attachment Circuit(ingress) Receive Fault"},
  50   {0x00000004, "Local Attachment Circuit(egress) Transmit Fault"},
  51   {0x00000020, "PW Forwarding Standby"},
  52   {0x00000040, "Request Switchover to this PW"},
  53   {0, NULL}
  54 };
  55
  56 /* PW-Status TLV dissector */
  57 void
  58 dissect_pw_status_tlv (tvbuff_t *tvb, proto_tree *tree, gint offset)
  59 {
  60   proto_item *ti;
  61   proto_tree *pw_oam_tlv_tree;
  62
  63
  64   ti = proto_tree_add_protocol_format (tree, proto_pw_oam, tvb, offset, 8,
  65                                        "Pseudo-Wire Status TLV");
  66
  67
  68   if (!tree)
  69     return;
  70
  71   pw_oam_tlv_tree = proto_item_add_subtree (ti, ett_pw_oam_tlv_tree);
  72
  73   proto_tree_add_item (pw_oam_tlv_tree, hf_pw_oam_tlv_reserved, tvb, offset,
  74                                     2, ENC_BIG_ENDIAN);
  75   proto_tree_add_item (pw_oam_tlv_tree, hf_pw_oam_tlv_type, tvb, offset,
  76                                     2, ENC_BIG_ENDIAN);
  77   offset = offset + 2;
  78
  79   proto_tree_add_item (pw_oam_tlv_tree, hf_pw_oam_tlv_len, tvb, offset,
  80                                     2, ENC_BIG_ENDIAN);
  81   offset = offset + 2;
  82   proto_tree_add_item (pw_oam_tlv_tree, hf_pw_oam_code, tvb, offset,
  83                                     4, ENC_BIG_ENDIAN);
  84   /*offset = offset + 4;*/
  85
  86   return ;
  87 }
  88
  89 /* Dissector for PW OAM protocol: RFC 6478 */
  90 static void
  91 dissect_pw_oam(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  92 {
  93   proto_item  *ti = NULL, *ti_flags = NULL;
  94   proto_tree  *pw_oam_tree = NULL, *pw_oam_flags = NULL;
  95
  96   guint8  offset        = 0;
  97   guint16 pw_tlv_type   = 0;
  98
  99   col_set_str(pinfo->cinfo, COL_PROTOCOL, "PW OAM");
 100   col_clear(pinfo->cinfo, COL_INFO);
 101
 102   if (!tree)
 103     return;
 104
 105   ti = proto_tree_add_item(tree, proto_pw_oam, tvb, 0, -1, ENC_NA);
 106
 107   pw_oam_tree = proto_item_add_subtree (ti, ett_pw_oam);
 108
 109   /* Refresh-Timer field */
 110   proto_tree_add_item (pw_oam_tree, hf_pw_oam_refresh_timer, tvb, offset,
 111                        2, ENC_BIG_ENDIAN);
 112   offset = offset + 2;
 113
 114   /* Total-TLV length */
 115   proto_tree_add_item (pw_oam_tree, hf_pw_oam_total_tlv_len, tvb, offset,
 116                        1, ENC_BIG_ENDIAN);
 117   offset = offset + 1;
 118
 119   /* Flags field */
 120   ti_flags = proto_tree_add_item (pw_oam_tree, hf_pw_oam_flags, tvb,
 121                                   offset, 1, ENC_BIG_ENDIAN);
 122   pw_oam_flags = proto_item_add_subtree(ti_flags, ett_pw_oam_flags);
 123   proto_tree_add_item (pw_oam_flags, hf_pw_oam_flags_a, tvb, offset, 1, ENC_BIG_ENDIAN);
 124
 125   offset = offset + 1;
 126   pw_tlv_type = tvb_get_ntohs (tvb, offset);
 127
 128   /* TLVs  */
 129   switch (pw_tlv_type)
 130     {
 131       /* The switch cases below have to be based on the LDP-name space.
 132           http://www.iana.org/assignments/ldp-namespaces/ldp-namespaces.xml */
 133
 134       case 0x096A: /* PW-Status TLV */
 135         dissect_pw_status_tlv (tvb, tree, offset);
 136         break;
 137
 138       default:
 139         break;
 140     }
 141
 142   return;
 143 }
 144
 145 void
 146 proto_register_pw_oam(void)
 147 {
 148   static hf_register_info hf[] = {
 149
 150     {&hf_pw_oam_refresh_timer,
 151       {"Refresh-Timer", "pw_oam.refresh-timer", FT_UINT16,
 152         BASE_HEX, NULL, 0x0, NULL, HFILL }},
 153
 154     {&hf_pw_oam_total_tlv_len,
 155       {"TLV Length", "pw_oam.total-tlv-len", FT_UINT8,
 156         BASE_HEX, NULL, 0x0, NULL, HFILL }},
 157
 158     {&hf_pw_oam_flags,
 159       {"Flags", "pw_oam.flags", FT_UINT8,
 160         BASE_HEX, NULL, 0x0000, "OAM Flags", HFILL }},
 161
 162     {&hf_pw_oam_flags_a,
 163       {"Acknowledgement", "pw_oam.flags_a",
 164         FT_BOOLEAN, 8, NULL, 0x0080, "ACK bit", HFILL}
 165     },
 166
 167     {&hf_pw_oam_tlv_reserved,
 168       {"Reserved", "pw_oam.tlv-reserved",
 169         FT_UINT16, BASE_HEX, NULL, 0xC000, NULL, HFILL}
 170     },
 171
 172     {&hf_pw_oam_tlv_type,
 173       {"TLV Type", "pw_oam.tlv-type",
 174         FT_UINT16, BASE_HEX, NULL, 0x3FFF, NULL, HFILL}
 175     },
 176
 177     {&hf_pw_oam_tlv_len,
 178       {"TLV Length", "pw_oam.tlv-len",
 179         FT_UINT16, BASE_HEX, NULL, 0x00, NULL, HFILL}
 180     },
 181
 182     {&hf_pw_oam_code,
 183       {"Status code", "pw_oam.code", FT_UINT16,
 184         BASE_HEX, VALS(pw_oam_code), 0x0, "PW Status Code", HFILL }
 185     },
 186
 187   };
 188
 189   static gint *ett[] = {
 190     &ett_pw_oam,
 191     &ett_pw_oam_tlv_tree,
 192     &ett_pw_oam_flags,
 193   };
 194
 195   proto_pw_oam =
 196     proto_register_protocol("Pseudo-Wire OAM", "PW-OAM "
 197         "Pseudo-Wire OAM Protocol",
 198         "pw_oam");
 199
 200   proto_register_field_array (proto_pw_oam, hf, array_length(hf));
 201   proto_register_subtree_array (ett, array_length(ett));
 202
 203   register_dissector("pw_oam", dissect_pw_oam, proto_pw_oam);
 204 }
 205
 206 /*
 207  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 208  *
 209  * Local variables:
 210  * c-basic-offset: 2
 211  * tab-width: 8
 212  * indent-tabs-mode: nil
 213  * End:
 214  *
 215  * vi: set shiftwidth=2 tabstop=8 expandtab:
 216  * :indentSize=2:tabSize=8:noTabs=true:
 217  */