epan/dissectors/packet-pppoe.c

   1 /* packet-pppoe.c
   2  * Routines for PPP Over Ethernet (PPPoE) packet disassembly (RFC2516)
   3  * Up to date with http://www.iana.org/assignments/pppoe-parameters (2008-04-30)
   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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  24  */
  25
  26 #ifdef HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #include <glib.h>
  31 #include <epan/packet.h>
  32 #include <epan/strutil.h>
  33 #include <epan/etypes.h>
  34 #include <epan/prefs.h>
  35 #include <epan/expert.h>
  36
  37 static int proto_pppoed = -1;
  38
  39 /* Common to session and discovery protocols */
  40 static gint hf_pppoe_version = -1;
  41 static gint hf_pppoe_type = -1;
  42 static gint hf_pppoe_code = -1;
  43 static gint hf_pppoe_session_id = -1;
  44 static gint hf_pppoe_payload_length = -1;
  45
  46 /* Discovery protocol fields */
  47 static gint hf_pppoed_tags = -1;
  48 static gint hf_pppoed_tag = -1;
  49 static gint hf_pppoed_tag_length = -1;
  50 static gint hf_pppoed_tag_unknown_data = -1;
  51 static gint hf_pppoed_tag_service_name = -1;
  52 static gint hf_pppoed_tag_ac_name = -1;
  53 static gint hf_pppoed_tag_host_uniq = -1;
  54 static gint hf_pppoed_tag_ac_cookie = -1;
  55 static gint hf_pppoed_tag_vendor_id = -1;
  56 static gint hf_pppoed_tag_vendor_unspecified = -1;
  57 static gint hf_pppoed_tag_credits = -1;
  58 static gint hf_pppoed_tag_credits_fcn = -1;
  59 static gint hf_pppoed_tag_credits_bcn = -1;
  60 static gint hf_pppoed_tag_metrics = -1;
  61 static gint hf_pppoed_tag_metrics_r = -1;
  62 static gint hf_pppoed_tag_metrics_rlq = -1;
  63 static gint hf_pppoed_tag_metrics_resource = -1;
  64 static gint hf_pppoed_tag_metrics_latency = -1;
  65 static gint hf_pppoed_tag_metrics_curr_drate = -1;
  66 static gint hf_pppoed_tag_metrics_max_drate = -1;
  67 static gint hf_pppoed_tag_mdr_units = -1;
  68 static gint hf_pppoed_tag_cdr_units = -1;
  69 static gint hf_pppoed_tag_seq_num = -1;
  70 static gint hf_pppoed_tag_cred_scale = -1;
  71 static gint hf_pppoed_tag_relay_session_id = -1;
  72 static gint hf_pppoed_tag_hurl = -1;
  73 static gint hf_pppoed_tag_motm = -1;
  74 static gint hf_pppoed_tag_max_payload = -1;
  75 static gint hf_pppoed_tag_ip_route_add = -1;
  76 static gint hf_pppoed_tag_service_name_error = -1;
  77 static gint hf_pppoed_tag_ac_system_error = -1;
  78 static gint hf_pppoed_tag_generic_error = -1;
  79
  80 /* Session protocol fields */
  81 static gint hf_pppoes_tags = -1;
  82 static gint hf_pppoes_tag = -1;
  83 static gint hf_pppoes_tag_credits = -1;
  84 static gint hf_pppoes_tag_credits_fcn = -1;
  85 static gint hf_pppoes_tag_credits_bcn = -1;
  86
  87 /* Session protocol fields */
  88
  89 static gint ett_pppoed = -1;
  90 static gint ett_pppoed_tags = -1;
  91
  92 static int proto_pppoes = -1;
  93
  94 static gint ett_pppoes = -1;
  95 static gint ett_pppoes_tags = -1;
  96
  97 /* PPPoE parent fields */
  98
  99 static int proto_pppoe = -1;
 100 static gint ett_pppoe = -1;
 101
 102
 103 /* Handle for calling for ppp dissector to handle session data */
 104 static dissector_handle_t ppp_handle;
 105
 106
 107 /* Preference for showing discovery tag values and lengths */
 108 static gboolean global_pppoe_show_tags_and_lengths = FALSE;
 109
 110
 111 #define PPPOE_CODE_SESSION    0x00
 112 #define PPPOE_CODE_PADO       0x07
 113 #define PPPOE_CODE_PADI       0x09
 114 #define PPPOE_CODE_PADG       0x0a
 115 #define PPPOE_CODE_PADC       0x0b
 116 #define PPPOE_CODE_PADQ       0x0c
 117 #define PPPOE_CODE_PADR       0x19
 118 #define PPPOE_CODE_PADS       0x65
 119 #define PPPOE_CODE_PADT       0xa7
 120 #define PPPOE_CODE_PADM       0xd3
 121 #define PPPOE_CODE_PADN       0xd4
 122
 123 #define PPPOE_TAG_EOL         0x0000
 124 #define PPPOE_TAG_SVC_NAME    0x0101
 125 #define PPPOE_TAG_AC_NAME     0x0102
 126 #define PPPOE_TAG_HOST_UNIQ   0x0103
 127 #define PPPOE_TAG_AC_COOKIE   0x0104
 128 #define PPPOE_TAG_VENDOR      0x0105
 129 #define PPPOE_TAG_CREDITS     0x0106
 130 #define PPPOE_TAG_METRICS     0x0107
 131 #define PPPOE_TAG_SEQ_NUM     0x0108
 132 #define PPPOE_TAG_CRED_SCALE  0x0109
 133 #define PPPOE_TAG_RELAY_ID    0x0110
 134 #define PPPOE_TAG_HURL        0x0111
 135 #define PPPOE_TAG_MOTM        0x0112
 136 #define PPPOE_TAG_MAX_PAYLD   0x0120
 137 #define PPPOE_TAG_IP_RT_ADD   0x0121
 138 #define PPPOE_TAG_SVC_ERR     0x0201
 139 #define PPPOE_TAG_AC_ERR      0x0202
 140 #define PPPOE_TAG_GENERIC_ERR 0x0203
 141
 142 #define PPPOE_CDR_MASK        0x06
 143 #define PPPOE_MDR_MASK        0x18
 144 #define PPPOE_RCV_ONLY_MASK   0x01
 145
 146 #define PPPOE_SCALE_KBPS      0x00
 147 #define PPPOE_SCALE_MBPS      0x01
 148 #define PPPOE_SCALE_GBPS      0x02
 149 #define PPPOE_SCALE_TBPS      0x03
 150
 151
 152 static const value_string code_vals[] = {
 153                 {PPPOE_CODE_SESSION, "Session Data"                             },
 154                 {PPPOE_CODE_PADO, "Active Discovery Offer (PADO)"               },
 155                 {PPPOE_CODE_PADI, "Active Discovery Initiation (PADI)"          },
 156                 {PPPOE_CODE_PADG, "Active Discovery Session-Grant (PADG)"       },
 157                 {PPPOE_CODE_PADC, "Active Discovery Session-Credit Resp.(PADC)" },
 158                 {PPPOE_CODE_PADQ, "Active Discovery Quality (PADQ)"             },
 159                 {PPPOE_CODE_PADR, "Active Discovery Request (PADR)"             },
 160                 {PPPOE_CODE_PADS, "Active Discovery Session-confirmation (PADS)"},
 161                 {PPPOE_CODE_PADT, "Active Discovery Terminate (PADT)"           },
 162                 {PPPOE_CODE_PADM, "Active Discovery Message (PADM)"             },
 163                 {PPPOE_CODE_PADN, "Active Discovery Network (PADN)"             },
 164                 {0,               NULL                                          }
 165 };
 166
 167
 168 static const value_string tag_vals[] = {
 169                 {PPPOE_TAG_EOL,        "End-Of-List"       },
 170                 {PPPOE_TAG_SVC_NAME,   "Service-Name"      },
 171                 {PPPOE_TAG_AC_NAME,    "AC-Name"           },
 172                 {PPPOE_TAG_HOST_UNIQ,  "Host-Uniq"         },
 173                 {PPPOE_TAG_AC_COOKIE,  "AC-Cookie"         },
 174                 {PPPOE_TAG_VENDOR,     "Vendor-Specific"   },
 175                 {PPPOE_TAG_CREDITS,    "Credits"           },
 176                 {PPPOE_TAG_METRICS,    "Metrics"           },
 177                 {PPPOE_TAG_SEQ_NUM,    "Sequence Number"    },
 178                 {PPPOE_TAG_CRED_SCALE, "Credit Scale Factor"},
 179                 {PPPOE_TAG_RELAY_ID,   "Relay-Session-Id"  },
 180                 {PPPOE_TAG_HURL,       "HURL"              },
 181                 {PPPOE_TAG_MOTM,       "MOTM"              },
 182                 {PPPOE_TAG_MAX_PAYLD,  "PPP-Max-Payload"   },
 183                 {PPPOE_TAG_IP_RT_ADD,  "IP Route Add"      },
 184                 {PPPOE_TAG_SVC_ERR,    "Service-Name-Error"},
 185                 {PPPOE_TAG_AC_ERR,     "AC-System-Error"   },
 186                 {PPPOE_TAG_GENERIC_ERR,"Generic-Error"     },
 187                 {0,                    NULL                }
 188 };
 189
 190 const value_string datarate_scale_vals[] = {
 191                 {PPPOE_SCALE_KBPS,      "kilobits per second"},
 192                 {PPPOE_SCALE_MBPS,      "megabits per second"},
 193                 {PPPOE_SCALE_GBPS,      "gigabits per second"},
 194                 {PPPOE_SCALE_TBPS,      "terabits per second"},
 195                 {0,                     NULL                 }
 196 };
 197
 198
 199 /* Dissect discovery protocol tags */
 200 static void
 201 dissect_pppoe_tags(tvbuff_t *tvb, packet_info *pinfo, int offset, proto_tree *tree,
 202                    int payload_length)
 203 {
 204         guint16 poe_tag;
 205         guint16 poe_tag_length;
 206         int tagstart;
 207         guint16 poe_rsv = 0;
 208
 209         proto_tree  *pppoe_tree;
 210         proto_item  *ti;
 211
 212         /* Start Decoding Here. */
 213         if (tree)
 214         {
 215                 /* Create tags subtree */
 216                 ti = proto_tree_add_item(tree, hf_pppoed_tags, tvb, offset, payload_length-6, FALSE);
 217                 pppoe_tree = proto_item_add_subtree(ti, ett_pppoed_tags);
 218
 219                 tagstart = offset;
 220
 221                 /* Loop until all data seen or End-Of-List tag found */
 222                 while (tagstart <= payload_length-2)
 223                 {
 224                         poe_tag = tvb_get_ntohs(tvb, tagstart);
 225                         poe_tag_length = tvb_get_ntohs(tvb, tagstart + 2);
 226
 227                         /* Tag value and data length */
 228                         if (global_pppoe_show_tags_and_lengths)
 229                         {
 230                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag, tvb, tagstart, 2, FALSE);
 231                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_length, tvb, tagstart+2, 2, FALSE);
 232                         }
 233
 234                         /* Show tag data */
 235                         switch (poe_tag)
 236                         {
 237                                 case PPPOE_TAG_SVC_NAME:
 238                                         if (poe_tag_length > 0)
 239                                         {
 240                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_service_name, tvb,
 241                                                                     tagstart+4, poe_tag_length, FALSE);
 242                                         }
 243                                         break;
 244                                 case PPPOE_TAG_AC_NAME:
 245                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_ac_name, tvb,
 246                                                             tagstart+4, poe_tag_length, FALSE);
 247                                         /* Show AC-Name in info column */
 248                                         if (check_col(pinfo->cinfo, COL_INFO))
 249                                         {
 250                                                 col_append_fstr(pinfo->cinfo, COL_INFO, " AC-Name='%s'",
 251                                                                tvb_get_ephemeral_string(tvb, tagstart+4, poe_tag_length));
 252                                         }
 253                                         break;
 254                                 case PPPOE_TAG_HOST_UNIQ:
 255                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_host_uniq, tvb,
 256                                                             tagstart+4, poe_tag_length, FALSE);
 257                                         break;
 258                                 case PPPOE_TAG_AC_COOKIE:
 259                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_ac_cookie, tvb,
 260                                                             tagstart+4, poe_tag_length, FALSE);
 261                                         break;
 262                                 case PPPOE_TAG_VENDOR:
 263                                         if (poe_tag_length >= 4)
 264                                         {
 265                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_vendor_id, tvb,
 266                                                                                         tagstart+4, 4, FALSE);
 267                                         }
 268                                         if (poe_tag_length > 4)
 269                                         {
 270                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_vendor_unspecified, tvb,
 271                                                                     tagstart+4+4, poe_tag_length-4, FALSE);
 272                                         }
 273                                         break;
 274                                 case PPPOE_TAG_CREDITS:
 275                                         if (poe_tag_length == 4)
 276                                         {
 277                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_credits_fcn, tvb,
 278                                                                     tagstart+4, 2, FALSE);
 279                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_credits_bcn, tvb,
 280                                                                     tagstart+6, 2, FALSE);
 281                                         } else {
 282                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_credits, tvb,
 283                                                                     tagstart+4, poe_tag_length, FALSE);
 284                                         }
 285                                         break;
 286                                 case PPPOE_TAG_METRICS:
 287                                         if (poe_tag_length == 10)
 288                                         {
 289                                                 poe_rsv = tvb_get_ntohs(tvb, tagstart+4);
 290
 291                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_mdr_units, tvb,
 292                                                                     tagstart+4, 2, FALSE);
 293                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_cdr_units, tvb,
 294                                                                     tagstart+4, 2, FALSE);
 295                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics_r, tvb,
 296                                                                     tagstart+4, 2, FALSE);
 297                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics_rlq, tvb,
 298                                                                     tagstart+6, 1, FALSE);
 299                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics_resource, tvb,
 300                                                                     tagstart+7, 1, FALSE);
 301                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics_latency, tvb,
 302                                                                     tagstart+8, 2, FALSE);
 303
 304                                                 /* CDR */
 305                                                 ti = proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics_curr_drate, tvb,
 306                                                                          tagstart+10, 2, FALSE);
 307
 308                                                 switch ((poe_rsv & PPPOE_CDR_MASK) >> 1)
 309                                                 {
 310                                                 case (PPPOE_SCALE_KBPS):
 311                                                     proto_item_append_text(ti, " kbps");
 312                                                     break;
 313                                                 case (PPPOE_SCALE_MBPS):
 314                                                     proto_item_append_text(ti, " mbps");
 315                                                     break;
 316                                                 case (PPPOE_SCALE_GBPS):
 317                                                     proto_item_append_text(ti, " gbps");
 318                                                     break;
 319                                                 case (PPPOE_SCALE_TBPS):
 320                                                     proto_item_append_text(ti, " tbps");
 321                                                     break;
 322                                                 }
 323
 324                                                 /* MDR */
 325                                                 ti = proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics_max_drate, tvb,
 326                                                                     tagstart+12, 2, FALSE);
 327
 328                                                 switch ((poe_rsv & PPPOE_MDR_MASK) >> 3)
 329                                                 {
 330                                                 case (PPPOE_SCALE_KBPS):
 331                                                     proto_item_append_text(ti, " kbps");
 332                                                     break;
 333                                                 case (PPPOE_SCALE_MBPS):
 334                                                     proto_item_append_text(ti, " mbps");
 335                                                     break;
 336                                                 case (PPPOE_SCALE_GBPS):
 337                                                     proto_item_append_text(ti, " gbps");
 338                                                     break;
 339                                                 case (PPPOE_SCALE_TBPS):
 340                                                     proto_item_append_text(ti, " tbps");
 341                                                     break;
 342                                                 }
 343
 344                                         } else {
 345                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics, tvb,
 346                                                                     tagstart+4, poe_tag_length, FALSE);
 347                                         }
 348                                         break;
 349                                 case PPPOE_TAG_SEQ_NUM:
 350                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_seq_num, tvb,
 351                                                             tagstart+4, poe_tag_length, FALSE);
 352                                         break;
 353                                 case PPPOE_TAG_CRED_SCALE:
 354                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_cred_scale, tvb,
 355                                                             tagstart+4, poe_tag_length, FALSE);
 356                                         break;
 357                                 case PPPOE_TAG_RELAY_ID:
 358                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_relay_session_id, tvb,
 359                                                             tagstart+4, poe_tag_length, FALSE);
 360                                         break;
 361                                 case PPPOE_TAG_HURL:
 362                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_hurl, tvb,
 363                                                             tagstart+4, poe_tag_length, FALSE);
 364                                         break;
 365                                 case PPPOE_TAG_MOTM:
 366                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_motm, tvb,
 367                                                             tagstart+4, poe_tag_length, FALSE);
 368                                         break;
 369                                 case PPPOE_TAG_MAX_PAYLD:
 370                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_max_payload, tvb,
 371                                                             tagstart+4, poe_tag_length, FALSE);
 372                                         break;
 373                                 case PPPOE_TAG_IP_RT_ADD:
 374                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_ip_route_add, tvb,
 375                                                             tagstart+4, poe_tag_length, FALSE);
 376                                         break;
 377
 378                                 /* These error tag values should be interpreted as a utf-8 unterminated
 379                                    strings. */
 380                                 case PPPOE_TAG_SVC_ERR:
 381                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_service_name_error, tvb,
 382                                                             tagstart+4, poe_tag_length, FALSE);
 383                                         break;
 384                                 case PPPOE_TAG_AC_ERR:
 385                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_ac_system_error, tvb,
 386                                                             tagstart+4, poe_tag_length, FALSE);
 387                                         break;
 388                                 case PPPOE_TAG_GENERIC_ERR:
 389                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_generic_error, tvb,
 390                                                             tagstart+4, poe_tag_length, FALSE);
 391                                         break;
 392
 393                                 /* Get out if see end-of-list tag */
 394                                 case PPPOE_TAG_EOL:
 395                                         return;
 396
 397                                 default:
 398                                         if (poe_tag_length > 0 )
 399                                         {
 400                                                 /* Presumably unknown tag;
 401                                                    show tag value if we didn't
 402                                                    do it above */
 403                                                 if (!global_pppoe_show_tags_and_lengths)
 404                                                 {
 405                                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag, tvb, tagstart, 2, FALSE);
 406                                                         proto_tree_add_item(pppoe_tree, hf_pppoed_tag_length, tvb, tagstart+2, 2, FALSE);
 407                                                 }
 408                                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_unknown_data, tvb,
 409                                                                     tagstart+4, poe_tag_length, FALSE);
 410                                         }
 411                         }
 412
 413                         tagstart += (4 + poe_tag_length);
 414                 }
 415         }
 416 }
 417
 418
 419 /* Discovery protocol, i.e. PPP session not yet established */
 420 static void dissect_pppoed(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 421 {
 422         guint8  pppoe_code;
 423         guint16 reported_payload_length;
 424
 425         proto_tree  *pppoe_tree = NULL;
 426         proto_item  *ti;
 427
 428         col_set_str(pinfo->cinfo, COL_PROTOCOL, "PPPoED");
 429         col_clear(pinfo->cinfo, COL_INFO);
 430
 431         /* Start Decoding Here. */
 432         pppoe_code = tvb_get_guint8(tvb, 1);
 433
 434         if (check_col(pinfo->cinfo, COL_INFO))
 435         {
 436                 col_append_str(pinfo->cinfo, COL_INFO, val_to_str(pppoe_code, code_vals, "Unknown"));
 437         }
 438
 439         /* Read length of payload */
 440         reported_payload_length = tvb_get_ntohs(tvb, 4);
 441
 442         if (tree)
 443         {
 444                 ti = proto_tree_add_item(tree, proto_pppoed, tvb, 0, reported_payload_length+6, FALSE);
 445                 pppoe_tree = proto_item_add_subtree(ti, ett_pppoed);
 446
 447                 /* Dissect fixed fields */
 448                 proto_tree_add_item(pppoe_tree, hf_pppoe_version, tvb, 0, 1, FALSE);
 449                 proto_tree_add_item(pppoe_tree, hf_pppoe_type, tvb, 0, 1, FALSE);
 450                 proto_tree_add_item(pppoe_tree, hf_pppoe_code, tvb, 1, 1, FALSE);
 451                 proto_tree_add_item(pppoe_tree, hf_pppoe_session_id, tvb, 2, 2, FALSE);
 452                 proto_tree_add_item(pppoe_tree, hf_pppoe_payload_length, tvb, 4, 2, FALSE);
 453         }
 454
 455         /* Now dissect any tags */
 456         if (reported_payload_length > 0)
 457         {
 458                 dissect_pppoe_tags(tvb, pinfo, 6, pppoe_tree, 6+reported_payload_length);
 459         }
 460
 461 }
 462
 463 void proto_register_pppoed(void)
 464 {
 465         static hf_register_info hf[] =
 466         {
 467                 /* Discovery tag fields */
 468                 { &hf_pppoed_tags,
 469                         { "PPPoE Tags", "pppoed.tags", FT_NONE, BASE_NONE,
 470                                  NULL, 0x0, NULL, HFILL
 471                         }
 472                 },
 473                 { &hf_pppoed_tag,
 474                         { "Tag", "pppoed.tag", FT_UINT16, BASE_HEX,
 475                                  VALS(tag_vals), 0x0, NULL, HFILL
 476                         }
 477                 },
 478                 { &hf_pppoed_tag_length,
 479                         { "Tag Length", "pppoed.tag_length", FT_UINT16, BASE_DEC,
 480                                  NULL, 0x0, NULL, HFILL
 481                         }
 482                 },
 483                 { &hf_pppoed_tag_unknown_data,
 484                         { "Unknown Data", "pppoed.tag.unknown_data", FT_BYTES, BASE_NONE,
 485                                  NULL, 0x0, NULL, HFILL
 486                         }
 487                 },
 488                 { &hf_pppoed_tag_service_name,
 489                         { "Service-Name", "pppoed.tags.service_name", FT_STRING, BASE_NONE,
 490                                  NULL, 0x0, NULL, HFILL
 491                         }
 492                 },
 493                 { &hf_pppoed_tag_ac_name,
 494                         { "AC-Name", "pppoed.tags.ac_name", FT_STRING, BASE_NONE,
 495                                  NULL, 0x0, NULL, HFILL
 496                         }
 497                 },
 498                 { &hf_pppoed_tag_host_uniq,
 499                         { "Host-Uniq", "pppoed.tags.host_uniq", FT_BYTES, BASE_NONE,
 500                                  NULL, 0x0, NULL, HFILL
 501                         }
 502                 },
 503                 { &hf_pppoed_tag_ac_cookie,
 504                         { "AC-Cookie", "pppoed.tags.ac_cookie", FT_BYTES, BASE_NONE,
 505                                  NULL, 0x0, NULL, HFILL
 506                         }
 507                 },
 508                 { &hf_pppoed_tag_vendor_id,
 509                         { "Vendor id", "pppoed.tags.vendor_id", FT_UINT32, BASE_HEX,
 510                                  NULL, 0x0, NULL, HFILL
 511                         }
 512                 },
 513                 { &hf_pppoed_tag_vendor_unspecified,
 514                         { "Vendor unspecified", "pppoed.tags.vendor_unspecified", FT_BYTES, BASE_NONE,
 515                                  NULL, 0x0, NULL, HFILL
 516                         }
 517                 },
 518                 { &hf_pppoed_tag_credits,
 519                         { "Credits", "pppoed.tags.credits", FT_BYTES, BASE_NONE,
 520                                  NULL, 0x0, NULL, HFILL
 521                         }
 522                 },
 523                 { &hf_pppoed_tag_credits_fcn,
 524                         { "FCN", "pppoed.tags.credits.fcn", FT_UINT16, BASE_DEC,
 525                                  NULL, 0x0, NULL, HFILL
 526                         }
 527                 },
 528                 { &hf_pppoed_tag_credits_bcn,
 529                         { "BCN", "pppoed.tags.credits.bcn", FT_UINT16, BASE_DEC,
 530                                  NULL, 0x0, NULL, HFILL
 531                         }
 532                 },
 533                 { &hf_pppoed_tag_metrics,
 534                         { "Metrics", "pppoed.tags.metrics", FT_BYTES, BASE_NONE,
 535                                  NULL, 0x0, NULL, HFILL
 536                         }
 537                 },
 538                 { &hf_pppoed_tag_metrics_r,
 539                         { "Receive Only", "pppoed.tags.metrics.r", FT_BOOLEAN, 16,
 540                                  NULL, PPPOE_RCV_ONLY_MASK, NULL, HFILL
 541                         }
 542                 },
 543                 { &hf_pppoed_tag_mdr_units,
 544                         { "MDR Units", "pppoed.tags.metrics.mdr_units", FT_UINT16, BASE_HEX,
 545                                  VALS(datarate_scale_vals), PPPOE_MDR_MASK, NULL, HFILL
 546                         }
 547                 },
 548                 { &hf_pppoed_tag_cdr_units,
 549                         { "CDR Units", "pppoed.tags.metrics.cdr_units", FT_UINT16, BASE_HEX,
 550                                  VALS(datarate_scale_vals), PPPOE_CDR_MASK, NULL, HFILL
 551                         }
 552                 },
 553                 { &hf_pppoed_tag_metrics_rlq,
 554                         { "Relative Link Quality", "pppoed.tags.metrics.rlq", FT_UINT8, BASE_DEC,
 555                                  NULL, 0x0, NULL, HFILL
 556                         }
 557                 },
 558                 { &hf_pppoed_tag_metrics_resource,
 559                         { "Resource", "pppoed.tags.metrics.resource", FT_UINT8, BASE_DEC,
 560                                  NULL, 0x0, NULL, HFILL
 561                         }
 562                 },
 563                 { &hf_pppoed_tag_metrics_latency,
 564                         { "Latency", "pppoed.tags.metrics.latency", FT_UINT16, BASE_DEC,
 565                                  NULL, 0x0, NULL, HFILL
 566                         }
 567                 },
 568                 { &hf_pppoed_tag_metrics_curr_drate,
 569                         { "Curr. datarate", "pppoed.tags.metrics.curr_drate", FT_UINT16, BASE_DEC,
 570                                  NULL, 0x0, NULL, HFILL
 571                         }
 572                 },
 573                 { &hf_pppoed_tag_metrics_max_drate,
 574                         { "Max. datarate", "pppoed.tags.metrics.max_drate", FT_UINT16, BASE_DEC,
 575                                  NULL, 0x0, NULL, HFILL
 576                         }
 577                 },
 578                 { &hf_pppoed_tag_seq_num,
 579                         { "Sequence Number", "pppoed.tags.seq_num", FT_UINT16, BASE_HEX,
 580                                  NULL, 0x0, NULL, HFILL
 581                         }
 582                 },
 583                 { &hf_pppoed_tag_cred_scale,
 584                         { "Credit Scale Factor", "pppoed.tags.credit_scale", FT_UINT16, BASE_DEC,
 585                                  NULL, 0x0, NULL, HFILL
 586                         }
 587                 },
 588                 { &hf_pppoed_tag_relay_session_id,
 589                         { "Relay-Session-Id", "pppoed.tags.relay_session_id", FT_BYTES, BASE_NONE,
 590                                  NULL, 0x0, NULL, HFILL
 591                         }
 592                 },
 593                 { &hf_pppoed_tag_hurl,
 594                         { "HURL", "pppoed.tags.hurl", FT_BYTES, BASE_NONE,
 595                                  NULL, 0x0, NULL, HFILL
 596                         }
 597                 },
 598                 { &hf_pppoed_tag_motm,
 599                         { "MOTM", "pppoed.tags.motm", FT_BYTES, BASE_NONE,
 600                                  NULL, 0x0, NULL, HFILL
 601                         }
 602                 },
 603                 { &hf_pppoed_tag_max_payload,
 604                         { "PPP Max Palyload", "pppoed.tags.max_payload", FT_BYTES, BASE_NONE,
 605                                  NULL, 0x0, NULL, HFILL
 606                         }
 607                 },
 608                 { &hf_pppoed_tag_ip_route_add,
 609                         { "IP Route Add", "pppoed.tags.ip_route_add", FT_BYTES, BASE_NONE,
 610                                  NULL, 0x0, NULL, HFILL
 611                         }
 612                 },
 613                 { &hf_pppoed_tag_service_name_error,
 614                         { "Service-Name-Error", "pppoed.tags.service_name_error", FT_STRING, BASE_NONE,
 615                                  NULL, 0x0, NULL, HFILL
 616                         }
 617                 },
 618                 { &hf_pppoed_tag_ac_system_error,
 619                         { "AC-System-Error", "pppoed.tags.ac_system_error", FT_STRING, BASE_NONE,
 620                                  NULL, 0x0, NULL, HFILL
 621                         }
 622                 },
 623                 { &hf_pppoed_tag_generic_error,
 624                         { "Generic-Error", "pppoed.tags.generic_error", FT_STRING, BASE_NONE,
 625                                  NULL, 0x0, NULL, HFILL
 626                         }
 627                 }
 628         };
 629
 630         static gint *ett[] = {
 631                 &ett_pppoed,
 632                 &ett_pppoed_tags
 633         };
 634
 635         module_t *pppoed_module;
 636
 637         /* Register protocol and fields */
 638         proto_pppoed = proto_register_protocol("PPP-over-Ethernet Discovery",
 639                                                "PPPoED", "pppoed");
 640         proto_register_subtree_array(ett, array_length(ett));
 641         proto_register_field_array(proto_pppoed, hf, array_length(hf));
 642
 643         /* Preference setting */
 644         pppoed_module = prefs_register_protocol(proto_pppoed, NULL);
 645         prefs_register_bool_preference(pppoed_module, "show_tags_and_lengths",
 646                                        "Show tag values and lengths",
 647                                        "Show values of tags and lengths of data fields",
 648                                        &global_pppoe_show_tags_and_lengths);
 649 }
 650
 651 void proto_reg_handoff_pppoed(void)
 652 {
 653         dissector_handle_t pppoed_handle;
 654
 655         pppoed_handle = create_dissector_handle(dissect_pppoed, proto_pppoed);
 656         dissector_add("ethertype", ETHERTYPE_PPPOED, pppoed_handle);
 657 }
 658
 659
 660 /* Session protocol, i.e. PPP session established */
 661 static void dissect_pppoes(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 662 {
 663         guint8  pppoe_code;
 664         guint16 pppoe_session_id;
 665         guint16 reported_payload_length;
 666         guint16 poe_tag;
 667         guint16 poe_tag_length;
 668         gint    actual_payload_length;
 669         gint    length, reported_length;
 670         gint    credit_offset = 0, tagstart = 0;
 671
 672         proto_tree  *pppoe_tree;
 673         proto_item  *ti = NULL;
 674         tvbuff_t    *next_tvb;
 675
 676         col_set_str(pinfo->cinfo, COL_PROTOCOL, "PPPoES");
 677         col_clear(pinfo->cinfo, COL_INFO);
 678
 679         /* Start Decoding Here. */
 680         pppoe_code = tvb_get_guint8(tvb, 1);
 681
 682         if (check_col(pinfo->cinfo,COL_INFO))
 683         {
 684                 col_add_str(pinfo->cinfo, COL_INFO,
 685                              val_to_str(pppoe_code, code_vals, "Unknown"));
 686         }
 687
 688         pppoe_session_id = tvb_get_ntohs(tvb, 2);
 689         reported_payload_length = tvb_get_ntohs(tvb, 4);
 690         actual_payload_length = tvb_reported_length_remaining(tvb, 6);
 691
 692         if (tree)
 693         {
 694                 ti = proto_tree_add_item(tree, proto_pppoes, tvb, 0, 6, FALSE);
 695                 pppoe_tree = proto_item_add_subtree(ti, ett_pppoe);
 696
 697                 proto_tree_add_item(pppoe_tree, hf_pppoe_version, tvb, 0, 1, FALSE);
 698                 proto_tree_add_item(pppoe_tree, hf_pppoe_type, tvb, 0, 1, FALSE);
 699                 proto_tree_add_item(pppoe_tree, hf_pppoe_code, tvb, 1, 1, FALSE);
 700                 proto_tree_add_item(pppoe_tree, hf_pppoe_session_id, tvb, 2, 2, FALSE);
 701                 ti = proto_tree_add_item(pppoe_tree, hf_pppoe_payload_length, tvb, 4, 2, FALSE);
 702
 703
 704                 if (PPPOE_TAG_CREDITS == tvb_get_ntohs(tvb, 6))
 705                 {
 706                         tagstart = 6;
 707                         poe_tag = tvb_get_ntohs(tvb, tagstart);
 708                         poe_tag_length = tvb_get_ntohs(tvb, tagstart + 2);
 709
 710                         /* Create tags subtree */
 711                         ti = proto_tree_add_item(pppoe_tree, hf_pppoes_tags, tvb, tagstart, 8, FALSE);
 712                         pppoe_tree = proto_item_add_subtree(ti, ett_pppoes_tags);
 713
 714                         /* Show tag data */
 715                         if (poe_tag_length == 4)
 716                         {
 717                                 proto_tree_add_item(pppoe_tree, hf_pppoes_tag_credits_fcn, tvb,
 718                                         tagstart+4, 2, FALSE);
 719                                 proto_tree_add_item(pppoe_tree, hf_pppoes_tag_credits_bcn, tvb,
 720                                         tagstart+6, 2, FALSE);
 721                         } else {
 722                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_credits, tvb,
 723                                         tagstart+4, poe_tag_length, FALSE);
 724                         }
 725
 726                         credit_offset = 8;
 727                 }
 728         }
 729
 730         /*
 731          * The only reason why the payload length from the header
 732          * should differ from the remaining data in the packet
 733          * would be if the total packet length, including Ethernet
 734          * CRC, were < 64 bytes, so that padding was required.
 735          *
 736          * That means that you have 14 bytes of Ethernet header,
 737          * 4 bytes of FCS, and fewer than 46 bytes of PPPoE packet.
 738          *
 739          * If that's not the case, we report a difference between
 740          * the payload length in the packet, and the amount of
 741          * data following the PPPoE header, as an error.
 742          */
 743         if (tvb_reported_length(tvb) > 46) {
 744                 /*
 745                  * Be forgiving about a possible trailing FCS.
 746                  *
 747                  * XXX - this dissector currently doesn't know
 748                  * whether any extra data past the end of the PPP
 749                  * payload is an FCS or not.
 750                  *
 751                  * If we know that we have an FCS, or that we don't
 752                  * have an FCS, we should have been handed a tvbuff
 753                  * without the FCS, and we should just do the strict
 754                  * length check.
 755                  *
 756                  * If we don't know whether we have an FCS, then:
 757                  *
 758                  *   if this isn't over Ethernet - the "E" in "PPPoE"
 759                  *   nonwithstanding, it can also run on top of 802.11,
 760                  *   for example - there's no trailer, so any data
 761                  *   past the payload length is either an FCS or
 762                  *   bogus;
 763                  *
 764                  *   if this is over Ethernet, there shouldn't be
 765                  *   a trailer, as the packet is long enough not to
 766                  *   require a trailer, as per the above;
 767                  *
 768                  * so perhaps we should assume that if we have exactly
 769                  * 4 bytes of extra information, it's an FCS, otherwise
 770                  * it's not.
 771                  *
 772                  * Perhaps we need to have a routine to call to
 773                  * do all the length checking, etc., and call it
 774                  * from here and from other dissectors where the
 775                  * protocol has a length field, or have a way to
 776                  * tell the dissector that called us which field
 777                  * has the length field and have *that* dissector
 778                  * do the length checking and add the expert info
 779                  * to the length field, *after* it does all the
 780                  * FCS heuristics.
 781                  */
 782                 if ((reported_payload_length != actual_payload_length) &&
 783                 ((reported_payload_length + 4) != actual_payload_length)) {
 784                     proto_item_append_text(ti, " [incorrect, should be %u]",
 785                         actual_payload_length);
 786                     expert_add_info_format(pinfo, ti, PI_MALFORMED,
 787                         PI_WARN, "Possible bad payload length %u != %u",
 788                         reported_payload_length, actual_payload_length);
 789                 }
 790         }
 791
 792         /*
 793          * Construct a tvbuff containing the PPP packet.
 794          */
 795         length = tvb_length_remaining(tvb, 6);
 796         reported_length = tvb_reported_length_remaining(tvb, 6);
 797         DISSECTOR_ASSERT(length >= 0);
 798         DISSECTOR_ASSERT(reported_length >= 0);
 799         if (length > reported_length)
 800                 length = reported_length;
 801         if ((guint)length > reported_payload_length)
 802                 length = reported_payload_length;
 803         if ((guint)reported_length > reported_payload_length)
 804                 reported_length = reported_payload_length;
 805         next_tvb = tvb_new_subset(tvb,(6 + credit_offset),
 806                                 (length - credit_offset),
 807                                 (reported_length - credit_offset));
 808         call_dissector(ppp_handle,next_tvb,pinfo,tree);
 809 }
 810
 811 void proto_register_pppoes(void)
 812 {
 813
 814         static hf_register_info hf[] =
 815         {
 816                 { &hf_pppoes_tags,
 817                         { "PPPoE Tags", "pppoes.tags", FT_NONE, BASE_NONE,
 818                                  NULL, 0x0, NULL, HFILL
 819                         }
 820                 },
 821                 { &hf_pppoes_tag,
 822                         { "Tag", "pppoes.tag", FT_UINT16, BASE_HEX,
 823                                  VALS(tag_vals), 0x0, NULL, HFILL
 824                         }
 825                 },
 826                 { &hf_pppoes_tag_credits,
 827                         { "Credits", "pppoes.tags.credits", FT_BYTES, BASE_NONE,
 828                                  NULL, 0x0, NULL, HFILL
 829                         }
 830                 },
 831                 { &hf_pppoes_tag_credits_fcn,
 832                         { "FCN", "pppoes.tags.credits.fcn", FT_UINT16, BASE_DEC,
 833                                  NULL, 0x0, NULL, HFILL
 834                         }
 835                 },
 836                 { &hf_pppoes_tag_credits_bcn,
 837                         { "BCN", "pppoes.tags.credits.bcn", FT_UINT16, BASE_DEC,
 838                                  NULL, 0x0, NULL, HFILL
 839                         }
 840                 }
 841         };
 842
 843         static gint *ett[] = {
 844                 &ett_pppoes,
 845                 &ett_pppoes_tags
 846         };
 847
 848         /* Register protocol */
 849         proto_pppoes = proto_register_protocol("PPP-over-Ethernet Session", "PPPoES", "pppoes");
 850
 851         proto_register_subtree_array(ett, array_length(ett));
 852         proto_register_field_array(proto_pppoes, hf, array_length(hf));
 853 }
 854
 855 void proto_register_pppoe(void)
 856 {
 857         static hf_register_info hf[] =
 858         {
 859                 /* These fields common to discovery and session protocols */
 860                 { &hf_pppoe_version,
 861                         { "Version", "pppoe.version", FT_UINT8, BASE_DEC,
 862                                  NULL, 0xf0, NULL, HFILL
 863                         }
 864                 },
 865                 { &hf_pppoe_type,
 866                         { "Type", "pppoe.type", FT_UINT8, BASE_DEC,
 867                                  NULL, 0x0f, NULL, HFILL
 868                         }
 869                 },
 870                 { &hf_pppoe_code,
 871                         { "Code", "pppoe.code", FT_UINT8, BASE_HEX,
 872                                  VALS(code_vals), 0x0, NULL, HFILL
 873                         }
 874                 },
 875                 { &hf_pppoe_session_id,
 876                         { "Session ID", "pppoe.session_id", FT_UINT16, BASE_HEX,
 877                                  NULL, 0x0, NULL, HFILL
 878                         }
 879                 },
 880                 { &hf_pppoe_payload_length,
 881                         { "Payload Length", "pppoe.payload_length", FT_UINT16, BASE_DEC,
 882                                  NULL, 0x0, NULL, HFILL
 883                         }
 884                 }
 885         };
 886
 887         static gint *ett[] = {
 888                 &ett_pppoe
 889         };
 890
 891         /* Register protocol */
 892         proto_pppoe = proto_register_protocol("PPP-over-Ethernet", "PPPoE", "pppoe");
 893
 894         proto_register_subtree_array(ett, array_length(ett));
 895         proto_register_field_array(proto_pppoe, hf, array_length(hf));
 896
 897 }
 898
 899 void proto_reg_handoff_pppoes(void)
 900 {
 901         dissector_handle_t pppoes_handle  =
 902             create_dissector_handle(dissect_pppoes, proto_pppoes);
 903         dissector_add("ethertype", ETHERTYPE_PPPOES, pppoes_handle);
 904
 905         /* Get a handle for the PPP dissector */
 906         ppp_handle = find_dissector("ppp");
 907 }