epan/dissectors/packet-mpls-y1711.c

   1 /* packet-mpls-y1711.c
   2  * Routines for (old) ITU-T MPLS OAM: it conforms to ITU-T Y.1711 and RFC 3429
   3  *
   4  * Copyright 2006, 2011 _FF_
   5  *
   6  * Francesco Fondelli <francesco dot fondelli, gmail dot com>
   7  *
   8  * Wireshark - Network traffic analyzer
   9  * By Gerald Combs <gerald@wireshark.org>
  10  * Copyright 1998 Gerald Combs
  11  *
  12  * SPDX-License-Identifier: GPL-2.0-or-later
  13  */
  14
  15 /*
  16  * FF: NOTES
  17  *
  18  * - this should dissect OAM pdus (identified by the MPLS_LABEL_OAM_ALERT = 14
  19  *   label) as described in ITU-T Y.1711 and RFC 3429.
  20  *
  21  * - this code used to be (since 2006) in packet-mpls.c ... nobody on this
  22  *   planet is using Y.1711 today (?), so thanks to the mpls subdissector
  23  *   table indexed by label value it has been moved here.
  24  */
  25
  26 #include "config.h"
  27
  28 #include <epan/packet.h>
  29 #include <epan/expert.h>
  30
  31 #include "packet-mpls.h"
  32
  33 void proto_register_mpls_y1711(void);
  34 void proto_reg_handoff_mpls_y1711(void);
  35
  36 static int proto_mpls_y1711;
  37
  38 static int hf_mpls_y1711_function_type;
  39 /* static int hf_mpls_y1711_ttsi; */
  40 static int hf_mpls_y1711_frequency;
  41 static int hf_mpls_y1711_defect_type;
  42 static int hf_mpls_y1711_defect_location;
  43 static int hf_mpls_y1711_bip16;
  44 /* Generated from convert_proto_tree_add_text.pl */
  45 static int hf_mpls_y1711_lsr_id;
  46 static int hf_mpls_y1711_lsp_id;
  47
  48 static int ett_mpls_y1711;
  49
  50 /* Generated from convert_proto_tree_add_text.pl */
  51 static expert_field ei_mpls_y1711_padding_not_ff;
  52 static expert_field ei_mpls_y1711_reserved_not_zero;
  53 static expert_field ei_mpls_y1711_ttsi_not_preset;
  54 static expert_field ei_mpls_y1711_minimum_payload;
  55 static expert_field ei_mpls_y1711_s_bit_not_one;
  56 static expert_field ei_mpls_y1711_no_OAM_alert_label;
  57 static expert_field ei_mpls_y1711_exp_bits_not_zero;
  58 static expert_field ei_mpls_y1711_ttl_not_one;
  59 static expert_field ei_mpls_y1711_padding_not_zero;
  60 static expert_field ei_mpls_y1711_unknown_pdu;
  61
  62 static dissector_handle_t mpls_y1711_handle;
  63
  64 static const value_string y1711_function_type_vals[] = {
  65     {0x00, "Reserved"                               },
  66     {0x01, "CV (Connectivity Verification)"         },
  67     {0x02, "FDI (Forward Defect Indicator)"         },
  68     {0x03, "BDI (Backward Defect Indicator)"        },
  69     {0x04, "Reserved for Performance packets"       },
  70     {0x05, "Reserved for LB-Req (Loopback Request)" },
  71     {0x06, "Reserved for LB-Rsp (Loopback Response)"},
  72     {0x07, "FDD (Fast Failure Detection)"           },
  73     {0,    NULL                                     }
  74 };
  75
  76 static const value_string y1711_frequency_vals[] = {
  77     {0x00, "Reserved"             },
  78     {0x01, "10 ms"                },
  79     {0x02, "20 ms"                },
  80     {0x03, "50 ms (default value)"},
  81     {0x04, "100 ms"               },
  82     {0x05, "200 ms"               },
  83     {0x06, "500 ms"               },
  84     /* 7-255 Reserved */
  85     {0,    NULL                   }
  86 };
  87
  88 static const value_string y1711_defect_type_vals[] = {
  89     {0x0000, "Reserved"      },
  90     {0x0101, "dServer"       },
  91     {0x0102, "dPeerME"       },
  92     {0x0201, "dLOCV"         },
  93     {0x0202, "dTTSI_Mismatch"},
  94     {0x0203, "dTTSI_Mismerge"},
  95     {0x0204, "dExcess"       },
  96     {0x02FF, "dUnknown"      },
  97     {0xFFFF, "Reserved"      },
  98     {0,      NULL            }
  99 };
 100
 101 static int
 102 dissect_mpls_y1711(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
 103 {
 104     struct mplsinfo *mplsinfo;
 105     int              offset          = 0;
 106     proto_tree      *mpls_y1711_tree;
 107     int              functype;
 108     tvbuff_t        *data_tvb;
 109
 110     static const uint8_t allone[]  = { 0xff, 0xff };
 111     static const uint8_t allzero[] = { 0x00, 0x00, 0x00, 0x00, 0x00,
 112                                       0x00, 0x00, 0x00, 0x00, 0x00,
 113                                       0x00, 0x00, 0x00, 0x00, 0x00,
 114                                       0x00, 0x00, 0x00, 0x00, 0x00 };
 115
 116     /* Reject the packet if data is NULL */
 117     if (data == NULL)
 118         return 0;
 119     mplsinfo = (struct mplsinfo *)data;
 120
 121     functype = tvb_get_uint8(tvb, offset);
 122     col_append_fstr(pinfo->cinfo, COL_INFO, " (Y.1711: %s)",
 123                     (functype == 0x01) ? "CV" :
 124                     (functype == 0x02) ? "FDI" :
 125                     (functype == 0x03) ? "BDI" :
 126                     (functype == 0x07) ? "FDD" :
 127                     "reserved/unknown");
 128
 129     /* sanity checks */
 130     if (tvb_reported_length(tvb) < 44) {
 131         /*
 132          * ITU-T Y.1711, 5.3: PDUs must have a minimum payload length of
 133          * 44 bytes
 134          */
 135         proto_tree_add_expert(tree, pinfo, &ei_mpls_y1711_minimum_payload, tvb, offset, -1);
 136         data_tvb = tvb_new_subset_remaining(tvb, offset);
 137         call_data_dissector(data_tvb, pinfo, tree);
 138
 139         return tvb_reported_length(tvb);
 140     }
 141
 142     mpls_y1711_tree = proto_tree_add_subtree(tree, tvb, offset, 44, ett_mpls_y1711, NULL, "Y.1711 OAM");
 143
 144     /* checks for exp, bos and ttl encoding */
 145     if (mplsinfo->label != MPLS_LABEL_OAM_ALERT)
 146         proto_tree_add_expert_format(mpls_y1711_tree, pinfo, &ei_mpls_y1711_no_OAM_alert_label, tvb, offset - 4, 3,
 147                                      "Warning: Y.1711 but no OAM alert label (%d) ?!", MPLS_LABEL_OAM_ALERT);
 148
 149     if (mplsinfo->exp != 0)
 150         proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_exp_bits_not_zero, tvb, offset - 2, 1);
 151
 152     if (mplsinfo->bos != 1)
 153         proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_s_bit_not_one, tvb, offset - 2, 1);
 154
 155     if (mplsinfo->ttl != 1)
 156         proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_ttl_not_one, tvb, offset - 1, 1);
 157
 158     /* starting dissection */
 159     functype = tvb_get_uint8(tvb, offset);
 160     proto_tree_add_item(mpls_y1711_tree, hf_mpls_y1711_function_type, tvb,
 161                         offset, 1,
 162                         ENC_LITTLE_ENDIAN);
 163     offset++;
 164
 165     switch (functype) {
 166     case 0x01: /* CV */
 167     {
 168         /* 3 octets reserved (all 0x00) */
 169         if (tvb_memeql(tvb, offset, allzero, 3) == -1) {
 170             proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_reserved_not_zero, tvb, offset, 3);
 171         }
 172         offset += 3;
 173
 174         /* ttsi (ipv4 flavor as in RFC 2373) */
 175         if (tvb_memeql(tvb, offset, allzero, 10) == -1) {
 176             proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_padding_not_zero, tvb, offset, 10);
 177         }
 178         offset += 10;
 179
 180         if (tvb_memeql(tvb, offset, allone, 2) == -1) {
 181             proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_padding_not_ff, tvb, offset, 2);
 182         }
 183         offset += 2;
 184
 185         proto_tree_add_item(mpls_y1711_tree, hf_mpls_y1711_lsr_id, tvb, offset, 4, ENC_BIG_ENDIAN);
 186         offset += 4;
 187
 188         proto_tree_add_item(mpls_y1711_tree, hf_mpls_y1711_lsp_id, tvb, offset, 4, ENC_BIG_ENDIAN);
 189         offset += 4;
 190
 191         /* 18 octets of padding (all 0x00) */
 192         if (tvb_memeql(tvb, offset, allzero, 18) == -1) {
 193             proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_padding_not_zero, tvb, offset, 18);
 194         }
 195         offset += 18;
 196     }
 197     break;
 198
 199     case 0x02: /* FDI */
 200     case 0x03: /* BDI */
 201     {
 202         /* 1 octets reserved (all 0x00) */
 203         if (tvb_memeql(tvb, offset, allzero, 1) == -1) {
 204             proto_tree_add_expert_format(mpls_y1711_tree, pinfo, &ei_mpls_y1711_reserved_not_zero, tvb, offset, 3,
 205                                          "Error: this byte is reserved and must be 0x00");
 206         }
 207         offset++;
 208
 209         proto_tree_add_item(mpls_y1711_tree, hf_mpls_y1711_defect_type, tvb,
 210                             offset, 2,
 211                             ENC_BIG_ENDIAN);
 212         offset += 2;
 213
 214         /*
 215          * ttsi (ipv4 flavor as in RFC 2373) is optional if not used must
 216          * be set to all 0x00
 217          */
 218         if (tvb_memeql(tvb, offset, allzero, 20) == 0) {
 219             proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_ttsi_not_preset, tvb, offset, 20);
 220             offset += 20;
 221         } else {
 222             if (tvb_memeql(tvb, offset, allzero, 10) == -1) {
 223                 proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_padding_not_zero, tvb, offset, 10);
 224             }
 225             offset += 10;
 226
 227             if (tvb_memeql(tvb, offset, allone, 2) == -1) {
 228                 proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_padding_not_ff, tvb, offset, 2);
 229             }
 230             offset += 2;
 231
 232             proto_tree_add_item(mpls_y1711_tree, hf_mpls_y1711_lsr_id, tvb, offset, 4, ENC_BIG_ENDIAN);
 233             offset += 4;
 234
 235             proto_tree_add_item(mpls_y1711_tree, hf_mpls_y1711_lsp_id, tvb, offset, 4, ENC_BIG_ENDIAN);
 236             offset += 4;
 237         }
 238
 239         /* defect location */
 240         proto_tree_add_item(mpls_y1711_tree, hf_mpls_y1711_defect_location, tvb,
 241                             offset, 4,
 242                             ENC_BIG_ENDIAN);
 243         offset += 4;
 244
 245         /* 14 octets of padding (all 0x00) */
 246         if (tvb_memeql(tvb, offset, allzero, 14) == -1) {
 247             proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_padding_not_zero, tvb, offset, 14);
 248         }
 249         offset += 14;
 250     }
 251     break;
 252
 253     case 0x07: /* FDD */
 254     {
 255         /* 3 octets reserved (all 0x00) */
 256         if (tvb_memeql(tvb, offset, allzero, 3) == -1) {
 257             proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_reserved_not_zero, tvb, offset, 3);
 258         }
 259         offset += 3;
 260
 261         /* ttsi (ipv4 flavor as in RFC 2373) */
 262         if (tvb_memeql(tvb, offset, allzero, 10) == -1) {
 263             proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_padding_not_zero, tvb, offset, 10);
 264         }
 265         offset += 10;
 266
 267         if (tvb_memeql(tvb, offset, allone, 2) == -1) {
 268             proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_padding_not_ff, tvb, offset, 2);
 269         }
 270         offset += 2;
 271
 272         proto_tree_add_item(mpls_y1711_tree, hf_mpls_y1711_lsr_id, tvb, offset, 4, ENC_BIG_ENDIAN);
 273         offset += 4;
 274
 275         proto_tree_add_item(mpls_y1711_tree, hf_mpls_y1711_lsp_id, tvb, offset, 4, ENC_BIG_ENDIAN);
 276         offset += 4;
 277
 278         proto_tree_add_item(mpls_y1711_tree, hf_mpls_y1711_frequency, tvb,
 279                             offset, 1,
 280                             ENC_LITTLE_ENDIAN);
 281         offset++;
 282
 283         /* 17 octets of padding (all 0x00) */
 284         if (tvb_memeql(tvb, offset, allzero, 17) == -1) {
 285             proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_padding_not_zero, tvb, offset, 17);
 286         }
 287         offset += 17;
 288     }
 289     break;
 290
 291     default:
 292         proto_tree_add_expert(mpls_y1711_tree, pinfo, &ei_mpls_y1711_unknown_pdu, tvb, offset - 1, -1);
 293         return offset;
 294     }
 295
 296     /* BIP16 */
 297     proto_tree_add_item(mpls_y1711_tree, hf_mpls_y1711_bip16, tvb, offset, 2,
 298                         ENC_BIG_ENDIAN);
 299     offset += 2;
 300
 301     return offset;
 302 }
 303
 304 void
 305 proto_register_mpls_y1711(void)
 306 {
 307     static hf_register_info hf[] = {
 308         {
 309             &hf_mpls_y1711_function_type,
 310             {
 311                 "Function Type", "mpls_y1711.function_type", FT_UINT8,
 312                 BASE_HEX, VALS(y1711_function_type_vals),
 313                 0x0, "Function Type codepoint", HFILL
 314             }
 315         },
 316 #if 0
 317         {
 318             &hf_mpls_y1711_ttsi,
 319             {
 320                 "Trail Termination Source Identifier",
 321                 "mpls_y1711.ttsi",
 322                 FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL
 323             }
 324         },
 325 #endif
 326         {
 327             &hf_mpls_y1711_frequency,
 328             {
 329                 "Frequency", "mpls_y1711.frequency", FT_UINT8,
 330                 BASE_HEX, VALS(y1711_frequency_vals), 0x0,
 331                 "Frequency of probe injection", HFILL
 332             }
 333         },
 334         {
 335             &hf_mpls_y1711_defect_type,
 336             {
 337                 "Defect Type", "mpls_y1711.defect_type", FT_UINT16,
 338                 BASE_HEX, VALS(y1711_defect_type_vals), 0x0, NULL, HFILL
 339             }
 340         },
 341         {
 342             &hf_mpls_y1711_defect_location,
 343             {
 344                 "Defect Location (AS)", "mpls_y1711.defect_location",
 345                 FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL
 346             }
 347         },
 348         {
 349             &hf_mpls_y1711_bip16,
 350             {
 351                 "BIP16", "mpls_y1711.bip16", FT_UINT16,
 352                 BASE_HEX, NULL, 0x0, NULL, HFILL
 353             }
 354         },
 355       /* Generated from convert_proto_tree_add_text.pl */
 356       { &hf_mpls_y1711_lsr_id, { "LSR ID", "mpls_y1711.lsr_id", FT_IPv4, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 357       { &hf_mpls_y1711_lsp_id, { "LSP ID", "mpls_y1711.lsp_id", FT_INT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
 358     };
 359
 360     static int *ett[] = {
 361         &ett_mpls_y1711
 362     };
 363
 364     static ei_register_info ei[] = {
 365         /* Generated from convert_proto_tree_add_text.pl */
 366         { &ei_mpls_y1711_minimum_payload, { "mpls_y1711.minimum_payload", PI_MALFORMED, PI_ERROR, "Must have a minimum payload length of 44 bytes", EXPFILL }},
 367         { &ei_mpls_y1711_no_OAM_alert_label, { "mpls_y1711.no_OAM_alert_label", PI_PROTOCOL, PI_WARN, "Y.1711 but no OAM alert label", EXPFILL }},
 368         { &ei_mpls_y1711_exp_bits_not_zero, { "mpls_y1711.exp_bits_not_0", PI_PROTOCOL, PI_WARN, "Exp bits should be 0", EXPFILL }},
 369         { &ei_mpls_y1711_s_bit_not_one, { "mpls_y1711.s_bit_not_1", PI_PROTOCOL, PI_WARN, "S bit should be 1", EXPFILL }},
 370         { &ei_mpls_y1711_ttl_not_one, { "mpls_y1711.ttl_not_1", PI_PROTOCOL, PI_WARN, "TTL should be 1", EXPFILL }},
 371         { &ei_mpls_y1711_reserved_not_zero, { "mpls_y1711.reserved_not_zero", PI_PROTOCOL, PI_WARN, "These bytes are reserved and must be 0x00", EXPFILL }},
 372         { &ei_mpls_y1711_padding_not_zero, { "mpls_y1711.padding_not_zero", PI_PROTOCOL, PI_WARN, "These bytes are padding and must be 0x00", EXPFILL }},
 373         { &ei_mpls_y1711_padding_not_ff, { "mpls_y1711.padding_not_ff", PI_PROTOCOL, PI_ERROR, "Error: these bytes are padding and must be 0xFF", EXPFILL }},
 374         { &ei_mpls_y1711_ttsi_not_preset, { "mpls_y1711.ttsi_not_preset", PI_PROTOCOL, PI_NOTE, "TTSI not preset (optional for FDI/BDI)", EXPFILL }},
 375         { &ei_mpls_y1711_unknown_pdu, { "mpls_y1711.unknown_pdu", PI_PROTOCOL, PI_WARN, "Unknown MPLS Y.1711 PDU", EXPFILL }},
 376     };
 377
 378     expert_module_t* expert_mpls_y1711;
 379
 380     proto_mpls_y1711 =
 381         proto_register_protocol("MPLS ITU-T Y.1711 OAM",
 382                                 "MPLS ITU-T Y.1711 OAM",
 383                                 "mpls_y1711");
 384     proto_register_field_array(proto_mpls_y1711, hf, array_length(hf));
 385     proto_register_subtree_array(ett, array_length(ett));
 386     expert_mpls_y1711 = expert_register_protocol(proto_mpls_y1711);
 387     expert_register_field_array(expert_mpls_y1711, ei, array_length(ei));
 388     mpls_y1711_handle = register_dissector("mpls_y1711", dissect_mpls_y1711, proto_mpls_y1711);
 389 }
 390
 391 void
 392 proto_reg_handoff_mpls_y1711(void)
 393 {
 394     dissector_add_uint("mpls.label",
 395                        MPLS_LABEL_OAM_ALERT /* 14 */,
 396                        mpls_y1711_handle);
 397 }
 398
 399 /*
 400  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 401  *
 402  * Local variables:
 403  * c-basic-offset: 4
 404  * tab-width: 8
 405  * indent-tabs-mode: nil
 406  * End:
 407  *
 408  * vi: set shiftwidth=4 tabstop=8 expandtab:
 409  * :indentSize=4:tabSize=8:noTabs=true:
 410  */