epan/dissectors/packet-mpls-mac.c

   1 /* packet-mpls-mac.c
   2  *
   3  * Routines for MPLS Media Access Control (MAC) Address Withdrawal over Static Pseudowire.
   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 #include "config.h"
  13
  14 #include <epan/packet.h>
  15 #include "packet-mpls.h"
  16
  17 void proto_register_mpls_mac(void);
  18 void proto_reg_handoff_mpls_mac(void);
  19
  20 static dissector_handle_t mpls_mac_handle;
  21
  22 static int proto_mpls_mac;
  23
  24 static int ett_mpls_mac;
  25 static int ett_mpls_mac_flags;
  26 static int ett_mpls_mac_tlv;
  27
  28 static int hf_mpls_mac_reserved;
  29 static int hf_mpls_mac_tlv_length_total;
  30 static int hf_mpls_mac_flags;
  31 static int hf_mpls_mac_flags_a;
  32 static int hf_mpls_mac_flags_r;
  33 static int hf_mpls_mac_flags_reserved;
  34 static int hf_mpls_mac_tlv;
  35 static int hf_mpls_mac_tlv_res;
  36 static int hf_mpls_mac_tlv_type;
  37 static int hf_mpls_mac_tlv_length;
  38 static int hf_mpls_mac_tlv_value;
  39 static int hf_mpls_mac_tlv_sequence_number;
  40
  41
  42 static int * const mpls_mac_flags[] = {
  43   &hf_mpls_mac_flags_a,
  44   &hf_mpls_mac_flags_r,
  45   &hf_mpls_mac_flags_reserved,
  46   NULL
  47 };
  48
  49 static int
  50 dissect_mpls_mac(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
  51 {
  52     proto_item *ti;
  53     proto_tree *mac_tree;
  54     uint32_t    offset = 0, tlv_length, offset_end;
  55
  56     col_set_str(pinfo->cinfo, COL_PROTOCOL, "MPLS-MAC");
  57     col_clear(pinfo->cinfo, COL_INFO);
  58
  59     ti = proto_tree_add_item(tree, proto_mpls_mac, tvb, 0, -1, ENC_NA);
  60     mac_tree = proto_item_add_subtree(ti, ett_mpls_mac);
  61     /* Reserved */
  62     proto_tree_add_item(mac_tree, hf_mpls_mac_reserved, tvb, offset, 2, ENC_NA);
  63     offset += 2;
  64     /* TLV length */
  65     proto_tree_add_item_ret_uint(mac_tree, hf_mpls_mac_tlv_length_total, tvb, offset, 1, ENC_BIG_ENDIAN, &tlv_length);
  66     offset += 1;
  67     /* Flags */
  68     proto_tree_add_bitmask(mac_tree, tvb, offset, hf_mpls_mac_flags,
  69                          ett_mpls_mac_flags,
  70                          mpls_mac_flags,
  71                          ENC_BIG_ENDIAN);
  72     offset += 1;
  73     offset_end = offset + tlv_length;
  74
  75     while(offset < offset_end){
  76         uint32_t type, length;
  77         proto_tree *tlv_tree;
  78
  79         ti = proto_tree_add_item(mac_tree, hf_mpls_mac_tlv, tvb, offset, 4, ENC_NA);
  80
  81         tlv_tree = proto_item_add_subtree(ti, ett_mpls_mac_tlv);
  82         /* res(erved) */
  83         proto_tree_add_item(tlv_tree, hf_mpls_mac_tlv_res, tvb, offset, 2, ENC_BIG_ENDIAN);
  84
  85         /* TLV Type */
  86         proto_tree_add_item_ret_uint(tlv_tree, hf_mpls_mac_tlv_type, tvb, offset, 2, ENC_BIG_ENDIAN, &type);
  87         offset += 2;
  88
  89         /* TLV Length */
  90         proto_tree_add_item_ret_uint(tlv_tree, hf_mpls_mac_tlv_length, tvb, offset, 2, ENC_BIG_ENDIAN, &length);
  91         offset += 2;
  92         proto_item_set_len(ti, 2+2+length);
  93         proto_item_append_text(ti, " (t=0x%x, l=%u)", type, length);
  94
  95         /* TLV Value */
  96         proto_tree_add_item(tlv_tree, hf_mpls_mac_tlv_value, tvb, offset, length, ENC_NA);
  97
  98         switch(type){
  99             case 0x0001:
 100                 proto_tree_add_item(tlv_tree, hf_mpls_mac_tlv_sequence_number, tvb, offset, 4, ENC_BIG_ENDIAN);
 101                 offset += 4;
 102             break;
 103             default:
 104                 offset += length;
 105             break;
 106         }
 107
 108     }
 109     return offset;
 110 }
 111
 112 void
 113 proto_register_mpls_mac(void)
 114 {
 115     static hf_register_info hf[] = {
 116         {
 117             &hf_mpls_mac_reserved,
 118             {
 119                 "Reserved", "mpls_mac.reserved",
 120                 FT_BYTES, BASE_NONE, NULL, 0x0,
 121                 NULL, HFILL
 122             }
 123         },
 124         {
 125             &hf_mpls_mac_tlv_length_total,
 126             {
 127                 "TLV Length (Total)", "mpls_mac.tlv_length_total",
 128                 FT_UINT8, BASE_DEC, NULL, 0x0,
 129                 NULL, HFILL
 130             }
 131         },
 132         {
 133             &hf_mpls_mac_flags,
 134             {
 135                 "Flags", "mpls_mac.flags",
 136                 FT_UINT8, BASE_HEX, NULL, 0x0,
 137                 NULL, HFILL
 138             }
 139         },
 140         {
 141             &hf_mpls_mac_flags_a,
 142             {
 143                 "Flags A", "mpls_mac.flags.a",
 144                 FT_BOOLEAN, 8, NULL, 0x80,
 145                 "set by a receiver to acknowledge receipt and processing of a MAC Address Withdraw OAM Message", HFILL
 146             }
 147         },
 148         {
 149             &hf_mpls_mac_flags_r,
 150             {
 151                 "Flags R", "mpls_mac.flags.r",
 152                 FT_BOOLEAN, 8, NULL, 0x40,
 153                 "Set to indicate if the sender is requesting reset of the sequence numbers", HFILL
 154             }
 155         },
 156         {
 157             &hf_mpls_mac_flags_reserved,
 158             {
 159                 "Flags Reserved", "mpls_mac.flags.reserved",
 160                 FT_UINT8, BASE_HEX, NULL, 0x3F,
 161                 NULL, HFILL
 162             }
 163         },
 164         {
 165             &hf_mpls_mac_tlv,
 166             {
 167                 "TLV", "mpls_mac.tlv",
 168                 FT_NONE, BASE_NONE, NULL, 0x0,
 169                 NULL, HFILL
 170             }
 171         },
 172         {
 173             &hf_mpls_mac_tlv_res,
 174             {
 175                 "Res(erved)", "mpls_mac.tlv.res",
 176                 FT_UINT16, BASE_HEX, NULL, 0xC000,
 177                 NULL, HFILL
 178             }
 179         },
 180         {
 181             &hf_mpls_mac_tlv_type,
 182             {
 183                 "TLV Type", "mpls_mac.tlv.type",
 184                 FT_UINT16, BASE_HEX, NULL, 0x3FFF,
 185                 NULL, HFILL
 186             }
 187         },
 188         {
 189             &hf_mpls_mac_tlv_length,
 190             {
 191                 "TLV Length", "mpls_mac.tlv.length",
 192                 FT_UINT16, BASE_DEC, NULL, 0x0,
 193                 NULL, HFILL
 194             }
 195         },
 196         {
 197             &hf_mpls_mac_tlv_value,
 198             {
 199                 "TLV Value", "mpls_mac.tlv.value",
 200                 FT_BYTES, BASE_NONE, NULL, 0x0,
 201                 NULL, HFILL
 202             }
 203         },
 204         {
 205             &hf_mpls_mac_tlv_sequence_number,
 206             {
 207                 "Sequence Number", "mpls_mac.tlv.sequence_number",
 208                 FT_UINT32, BASE_DEC, NULL, 0x0,
 209                 NULL, HFILL
 210             }
 211         },
 212     };
 213
 214     static int *ett[] = {
 215         &ett_mpls_mac,
 216         &ett_mpls_mac_flags,
 217         &ett_mpls_mac_tlv,
 218     };
 219
 220     proto_mpls_mac =
 221         proto_register_protocol("Media Access Control (MAC) Address Withdrawal over Static Pseudowire", "MPLS-MAC", "mpls_mac");
 222
 223     proto_register_field_array(proto_mpls_mac, hf, array_length(hf));
 224     proto_register_subtree_array(ett, array_length(ett));
 225
 226     mpls_mac_handle = register_dissector("mpls_mac", dissect_mpls_mac, proto_mpls_mac);
 227 }
 228
 229 void
 230 proto_reg_handoff_mpls_mac(void)
 231 {
 232     dissector_add_uint("pwach.channel_type", PW_ACH_TYPE_MAC, mpls_mac_handle);
 233 }
 234
 235 /*
 236  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 237  *
 238  * Local variables:
 239  * c-basic-offset: 4
 240  * tab-width: 8
 241  * indent-tabs-mode: nil
 242  * End:
 243  *
 244  * vi: set shiftwidth=4 tabstop=8 expandtab:
 245  * :indentSize=4:tabSize=8:noTabs=true:
 246  */