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,    "Seqence 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         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 429         {
 430                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "PPPoED");
 431         }
 432         if (check_col(pinfo->cinfo, COL_INFO))
 433         {
 434                 col_clear(pinfo->cinfo, COL_INFO);
 435         }
 436
 437         /* Start Decoding Here. */
 438         pppoe_code = tvb_get_guint8(tvb, 1);
 439
 440         if (check_col(pinfo->cinfo, COL_INFO))
 441         {
 442                 col_append_str(pinfo->cinfo, COL_INFO, val_to_str(pppoe_code, code_vals, "Unknown"));
 443         }
 444
 445         /* Read length of payload */
 446         reported_payload_length = tvb_get_ntohs(tvb, 4);
 447
 448         if (tree)
 449         {
 450                 ti = proto_tree_add_item(tree, proto_pppoed, tvb, 0, reported_payload_length+6, FALSE);
 451                 pppoe_tree = proto_item_add_subtree(ti, ett_pppoed);
 452
 453                 /* Dissect fixed fields */
 454                 proto_tree_add_item(pppoe_tree, hf_pppoe_version, tvb, 0, 1, FALSE);
 455                 proto_tree_add_item(pppoe_tree, hf_pppoe_type, tvb, 0, 1, FALSE);
 456                 proto_tree_add_item(pppoe_tree, hf_pppoe_code, tvb, 1, 1, FALSE);
 457                 proto_tree_add_item(pppoe_tree, hf_pppoe_session_id, tvb, 2, 2, FALSE);
 458                 proto_tree_add_item(pppoe_tree, hf_pppoe_payload_length, tvb, 4, 2, FALSE);
 459         }
 460
 461         /* Now dissect any tags */
 462         if (reported_payload_length > 0)
 463         {
 464                 dissect_pppoe_tags(tvb, pinfo, 6, pppoe_tree, 6+reported_payload_length);
 465         }
 466
 467 }
 468
 469 void proto_register_pppoed(void)
 470 {
 471         static hf_register_info hf[] =
 472         {
 473                 /* Discovery tag fields */
 474                 { &hf_pppoed_tags,
 475                         { "PPPoE Tags", "pppoed.tags", FT_NONE, BASE_NONE,
 476                                  NULL, 0x0, "", HFILL
 477                         }
 478                 },
 479                 { &hf_pppoed_tag,
 480                         { "Tag", "pppoed.tag", FT_UINT16, BASE_HEX,
 481                                  VALS(tag_vals), 0x0, "", HFILL
 482                         }
 483                 },
 484                 { &hf_pppoed_tag_length,
 485                         { "Tag Length", "pppoed.tag_length", FT_UINT16, BASE_DEC,
 486                                  NULL, 0x0, "", HFILL
 487                         }
 488                 },
 489                 { &hf_pppoed_tag_unknown_data,
 490                         { "Unknown Data", "pppoed.tag.unknown_data", FT_BYTES, BASE_NONE,
 491                                  NULL, 0x0, "", HFILL
 492                         }
 493                 },
 494                 { &hf_pppoed_tag_service_name,
 495                         { "Service-Name", "pppoed.tags.service_name", FT_STRING, BASE_NONE,
 496                                  NULL, 0x0, "", HFILL
 497                         }
 498                 },
 499                 { &hf_pppoed_tag_ac_name,
 500                         { "AC-Name", "pppoed.tags.ac_name", FT_STRING, BASE_NONE,
 501                                  NULL, 0x0, "", HFILL
 502                         }
 503                 },
 504                 { &hf_pppoed_tag_host_uniq,
 505                         { "Host-Uniq", "pppoed.tags.host_uniq", FT_BYTES, BASE_NONE,
 506                                  NULL, 0x0, "", HFILL
 507                         }
 508                 },
 509                 { &hf_pppoed_tag_ac_cookie,
 510                         { "AC-Cookie", "pppoed.tags.ac_cookie", FT_BYTES, BASE_NONE,
 511                                  NULL, 0x0, "", HFILL
 512                         }
 513                 },
 514                 { &hf_pppoed_tag_vendor_id,
 515                         { "Vendor id", "pppoed.tags.vendor_id", FT_UINT32, BASE_HEX,
 516                                  NULL, 0x0, "", HFILL
 517                         }
 518                 },
 519                 { &hf_pppoed_tag_vendor_unspecified,
 520                         { "Vendor unspecified", "pppoed.tags.vendor_unspecified", FT_BYTES, BASE_HEX,
 521                                  NULL, 0x0, "", HFILL
 522                         }
 523                 },
 524                 { &hf_pppoed_tag_credits,
 525                         { "Credits", "pppoed.tags.credits", FT_BYTES, BASE_HEX,
 526                                  NULL, 0x0, "", HFILL
 527                         }
 528                 },
 529                 { &hf_pppoed_tag_credits_fcn,
 530                         { "FCN", "pppoed.tags.credits.fcn", FT_UINT16, BASE_DEC,
 531                                  NULL, 0x0, "", HFILL
 532                         }
 533                 },
 534                 { &hf_pppoed_tag_credits_bcn,
 535                         { "BCN", "pppoed.tags.credits.bcn", FT_UINT16, BASE_DEC,
 536                                  NULL, 0x0, "", HFILL
 537                         }
 538                 },
 539                 { &hf_pppoed_tag_metrics,
 540                         { "Metrics", "pppoed.tags.metrics", FT_BYTES, BASE_HEX,
 541                                  NULL, 0x0, "", HFILL
 542                         }
 543                 },
 544                 { &hf_pppoed_tag_metrics_r,
 545                         { "Receive Only", "pppoed.tags.metrics.r", FT_BOOLEAN, 16,
 546                                  NULL, PPPOE_RCV_ONLY_MASK, "", HFILL
 547                         }
 548                 },
 549                 { &hf_pppoed_tag_mdr_units,
 550                         { "MDR Units", "pppoed.tags.metrics.mdr_units", FT_UINT16, BASE_HEX,
 551                                  VALS(datarate_scale_vals), PPPOE_MDR_MASK, "", HFILL
 552                         }
 553                 },
 554                 { &hf_pppoed_tag_cdr_units,
 555                         { "CDR Units", "pppoed.tags.metrics.cdr_units", FT_UINT16, BASE_HEX,
 556                                  VALS(datarate_scale_vals), PPPOE_CDR_MASK, "", HFILL
 557                         }
 558                 },
 559                 { &hf_pppoed_tag_metrics_rlq,
 560                         { "Relative Link Quality", "pppoed.tags.metrics.rlq", FT_UINT8, BASE_DEC,
 561                                  NULL, 0x0, "", HFILL
 562                         }
 563                 },
 564                 { &hf_pppoed_tag_metrics_resource,
 565                         { "Resource", "pppoed.tags.metrics.resource", FT_UINT8, BASE_DEC,
 566                                  NULL, 0x0, "", HFILL
 567                         }
 568                 },
 569                 { &hf_pppoed_tag_metrics_latency,
 570                         { "Latency", "pppoed.tags.metrics.latency", FT_UINT16, BASE_DEC,
 571                                  NULL, 0x0, "", HFILL
 572                         }
 573                 },
 574                 { &hf_pppoed_tag_metrics_curr_drate,
 575                         { "Curr. datarate", "pppoed.tags.metrics.curr_drate", FT_UINT16, BASE_DEC,
 576                                  NULL, 0x0, "", HFILL
 577                         }
 578                 },
 579                 { &hf_pppoed_tag_metrics_max_drate,
 580                         { "Max. datarate", "pppoed.tags.metrics.max_drate", FT_UINT16, BASE_DEC,
 581                                  NULL, 0x0, "", HFILL
 582                         }
 583                 },
 584                 { &hf_pppoed_tag_seq_num,
 585                         { "Sequence Number", "pppoed.tags.seq_num", FT_UINT16, BASE_HEX,
 586                                  NULL, 0x0, "", HFILL
 587                         }
 588                 },
 589                 { &hf_pppoed_tag_cred_scale,
 590                         { "Credit Scale Factor", "pppoed.tags.credit_scale", FT_UINT16, BASE_DEC,
 591                                  NULL, 0x0, "", HFILL
 592                         }
 593                 },
 594                 { &hf_pppoed_tag_relay_session_id,
 595                         { "Relay-Session-Id", "pppoed.tags.relay_session_id", FT_BYTES, BASE_NONE,
 596                                  NULL, 0x0, "", HFILL
 597                         }
 598                 },
 599                 { &hf_pppoed_tag_hurl,
 600                         { "HURL", "pppoed.tags.hurl", FT_BYTES, BASE_HEX,
 601                                  NULL, 0x0, "", HFILL
 602                         }
 603                 },
 604                 { &hf_pppoed_tag_motm,
 605                         { "MOTM", "pppoed.tags.motm", FT_BYTES, BASE_HEX,
 606                                  NULL, 0x0, "", HFILL
 607                         }
 608                 },
 609                 { &hf_pppoed_tag_max_payload,
 610                         { "PPP Max Palyload", "pppoed.tags.max_payload", FT_BYTES, BASE_HEX,
 611                                  NULL, 0x0, "", HFILL
 612                         }
 613                 },
 614                 { &hf_pppoed_tag_ip_route_add,
 615                         { "IP Route Add", "pppoed.tags.ip_route_add", FT_BYTES, BASE_HEX,
 616                                  NULL, 0x0, "", HFILL
 617                         }
 618                 },
 619                 { &hf_pppoed_tag_service_name_error,
 620                         { "Service-Name-Error", "pppoed.tags.service_name_error", FT_STRING, BASE_NONE,
 621                                  NULL, 0x0, "", HFILL
 622                         }
 623                 },
 624                 { &hf_pppoed_tag_ac_system_error,
 625                         { "AC-System-Error", "pppoed.tags.ac_system_error", FT_STRING, BASE_NONE,
 626                                  NULL, 0x0, "", HFILL
 627                         }
 628                 },
 629                 { &hf_pppoed_tag_generic_error,
 630                         { "Generic-Error", "pppoed.tags.generic_error", FT_STRING, BASE_NONE,
 631                                  NULL, 0x0, "", HFILL
 632                         }
 633                 }
 634         };
 635
 636         static gint *ett[] = {
 637                 &ett_pppoed,
 638                 &ett_pppoed_tags
 639         };
 640
 641         module_t *pppoed_module;
 642
 643         /* Register protocol and fields */
 644         proto_pppoed = proto_register_protocol("PPP-over-Ethernet Discovery",
 645                                                "PPPoED", "pppoed");
 646         proto_register_subtree_array(ett, array_length(ett));
 647         proto_register_field_array(proto_pppoed, hf, array_length(hf));
 648
 649         /* Preference setting */
 650         pppoed_module = prefs_register_protocol(proto_pppoed, NULL);
 651         prefs_register_bool_preference(pppoed_module, "show_tags_and_lengths",
 652                                        "Show tag values and lengths",
 653                                        "Show values of tags and lengths of data fields",
 654                                        &global_pppoe_show_tags_and_lengths);
 655 }
 656
 657 void proto_reg_handoff_pppoed(void)
 658 {
 659         dissector_handle_t pppoed_handle;
 660
 661         pppoed_handle = create_dissector_handle(dissect_pppoed, proto_pppoed);
 662         dissector_add("ethertype", ETHERTYPE_PPPOED, pppoed_handle);
 663 }
 664
 665
 666 /* Session protocol, i.e. PPP session established */
 667 static void dissect_pppoes(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 668 {
 669         guint8  pppoe_code;
 670         guint16 pppoe_session_id;
 671         guint16 reported_payload_length;
 672         guint16 poe_tag;
 673         guint16 poe_tag_length;
 674         gint    actual_payload_length;
 675         gint    length, reported_length;
 676         gint    credit_offset = 0, tagstart = 0;
 677
 678         proto_tree  *pppoe_tree;
 679         proto_item  *ti = NULL;
 680         tvbuff_t    *next_tvb;
 681
 682         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 683         {
 684                 col_set_str(pinfo->cinfo,COL_PROTOCOL, "PPPoES");
 685         }
 686         if (check_col(pinfo->cinfo,COL_INFO))
 687         {
 688                 col_clear(pinfo->cinfo,COL_INFO);
 689         }
 690
 691         /* Start Decoding Here. */
 692         pppoe_code = tvb_get_guint8(tvb, 1);
 693
 694         if (check_col(pinfo->cinfo,COL_INFO))
 695         {
 696                 col_add_str(pinfo->cinfo, COL_INFO,
 697                              val_to_str(pppoe_code, code_vals, "Unknown"));
 698         }
 699
 700         pppoe_session_id = tvb_get_ntohs(tvb, 2);
 701         reported_payload_length = tvb_get_ntohs(tvb, 4);
 702         actual_payload_length = tvb_reported_length_remaining(tvb, 6);
 703
 704         if (tree)
 705         {
 706                 ti = proto_tree_add_item(tree, proto_pppoes, tvb, 0, 6, FALSE);
 707                 pppoe_tree = proto_item_add_subtree(ti, ett_pppoe);
 708
 709                 proto_tree_add_item(pppoe_tree, hf_pppoe_version, tvb, 0, 1, FALSE);
 710                 proto_tree_add_item(pppoe_tree, hf_pppoe_type, tvb, 0, 1, FALSE);
 711                 proto_tree_add_item(pppoe_tree, hf_pppoe_code, tvb, 1, 1, FALSE);
 712                 proto_tree_add_item(pppoe_tree, hf_pppoe_session_id, tvb, 2, 2, FALSE);
 713                 ti = proto_tree_add_item(pppoe_tree, hf_pppoe_payload_length, tvb, 4, 2, FALSE);
 714
 715
 716                 if (PPPOE_TAG_CREDITS == tvb_get_ntohs(tvb, 6))
 717                 {
 718                         tagstart = 6;
 719                         poe_tag = tvb_get_ntohs(tvb, tagstart);
 720                         poe_tag_length = tvb_get_ntohs(tvb, tagstart + 2);
 721
 722                         /* Create tags subtree */
 723                         ti = proto_tree_add_item(pppoe_tree, hf_pppoes_tags, tvb, tagstart, 8, FALSE);
 724                         pppoe_tree = proto_item_add_subtree(ti, ett_pppoes_tags);
 725
 726                         /* Show tag data */
 727                         if (poe_tag_length == 4)
 728                         {
 729                                 proto_tree_add_item(pppoe_tree, hf_pppoes_tag_credits_fcn, tvb,
 730                                         tagstart+4, 2, FALSE);
 731                                 proto_tree_add_item(pppoe_tree, hf_pppoes_tag_credits_bcn, tvb,
 732                                         tagstart+6, 2, FALSE);
 733                         } else {
 734                                 proto_tree_add_item(pppoe_tree, hf_pppoed_tag_credits, tvb,
 735                                         tagstart+4, poe_tag_length, FALSE);
 736                         }
 737
 738                         credit_offset = 8;
 739                 }
 740         }
 741         /*
 742          * The only reason why the payload length from the header
 743          * should differ from the remaining data in the packet
 744          * would be if the total packet length, including Ethernet
 745          * CRC, were < 64 bytes, so that padding was required.
 746          *
 747          * That means that you have 14 bytes of Ethernet header,
 748          * 4 bytes of FCS, and fewer than 46 bytes of PPPoE packet.
 749          *
 750          * If that's not the case, we report a difference between
 751          * the payload length in the packet, and the amount of
 752          * data following the PPPoE header, as an error.
 753          */
 754         if (tvb_reported_length(tvb) > 46 &&
 755             reported_payload_length != actual_payload_length) {
 756                 proto_item_append_text(ti, " [incorrect, should be %u]",
 757                                        actual_payload_length);
 758                 expert_add_info_format(pinfo, ti, PI_MALFORMED,
 759                     PI_WARN, "Possible bad payload length %u != %u",
 760                     reported_payload_length, actual_payload_length);
 761         }
 762
 763         /*
 764          * Construct a tvbuff containing the PPP packet.
 765          */
 766         length = tvb_length_remaining(tvb, 6);
 767         reported_length = tvb_reported_length_remaining(tvb, 6);
 768         DISSECTOR_ASSERT(length >= 0);
 769         DISSECTOR_ASSERT(reported_length >= 0);
 770         if (length > reported_length)
 771                 length = reported_length;
 772         if ((guint)length > reported_payload_length)
 773                 length = reported_payload_length;
 774         if ((guint)reported_length > reported_payload_length)
 775                 reported_length = reported_payload_length;
 776         next_tvb = tvb_new_subset(tvb,(6 + credit_offset),
 777                                 (length - credit_offset),
 778                                 (reported_length - credit_offset));
 779         call_dissector(ppp_handle,next_tvb,pinfo,tree);
 780 }
 781
 782 void proto_register_pppoes(void)
 783 {
 784
 785         static hf_register_info hf[] =
 786         {
 787                 { &hf_pppoes_tags,
 788                         { "PPPoE Tags", "pppoes.tags", FT_NONE, BASE_NONE,
 789                                  NULL, 0x0, "", HFILL
 790                         }
 791                 },
 792                 { &hf_pppoes_tag,
 793                         { "Tag", "pppoes.tag", FT_UINT16, BASE_HEX,
 794                                  VALS(tag_vals), 0x0, "", HFILL
 795                         }
 796                 },
 797                 { &hf_pppoes_tag_credits,
 798                         { "Credits", "pppoes.tags.credits", FT_BYTES, BASE_HEX,
 799                                  NULL, 0x0, "", HFILL
 800                         }
 801                 },
 802                 { &hf_pppoes_tag_credits_fcn,
 803                         { "FCN", "pppoes.tags.credits.fcn", FT_UINT16, BASE_DEC,
 804                                  NULL, 0x0, "", HFILL
 805                         }
 806                 },
 807                 { &hf_pppoes_tag_credits_bcn,
 808                         { "BCN", "pppoes.tags.credits.bcn", FT_UINT16, BASE_DEC,
 809                                  NULL, 0x0, "", HFILL
 810                         }
 811                 }
 812         };
 813
 814         static gint *ett[] = {
 815                 &ett_pppoes,
 816                 &ett_pppoes_tags
 817         };
 818
 819         /* Register protocol */
 820         proto_pppoes = proto_register_protocol("PPP-over-Ethernet Session", "PPPoES", "pppoes");
 821
 822         proto_register_subtree_array(ett, array_length(ett));
 823         proto_register_field_array(proto_pppoes, hf, array_length(hf));
 824 }
 825
 826 void proto_register_pppoe(void)
 827 {
 828         static hf_register_info hf[] =
 829         {
 830                 /* These fields common to discovery and session protocols */
 831                 { &hf_pppoe_version,
 832                         { "Version", "pppoe.version", FT_UINT8, BASE_DEC,
 833                                  NULL, 0xf0, "", HFILL
 834                         }
 835                 },
 836                 { &hf_pppoe_type,
 837                         { "Type", "pppoe.type", FT_UINT8, BASE_DEC,
 838                                  NULL, 0x0f, "", HFILL
 839                         }
 840                 },
 841                 { &hf_pppoe_code,
 842                         { "Code", "pppoe.code", FT_UINT8, BASE_HEX,
 843                                  VALS(code_vals), 0x0, "", HFILL
 844                         }
 845                 },
 846                 { &hf_pppoe_session_id,
 847                         { "Session ID", "pppoe.session_id", FT_UINT16, BASE_HEX,
 848                                  NULL, 0x0, "", HFILL
 849                         }
 850                 },
 851                 { &hf_pppoe_payload_length,
 852                         { "Payload Length", "pppoe.payload_length", FT_UINT16, BASE_DEC,
 853                                  NULL, 0x0, "", HFILL
 854                         }
 855                 }
 856         };
 857
 858         static gint *ett[] = {
 859                 &ett_pppoe
 860         };
 861
 862         /* Register protocol */
 863         proto_pppoe = proto_register_protocol("PPP-over-Ethernet", "PPPoE", "pppoe");
 864
 865         proto_register_subtree_array(ett, array_length(ett));
 866         proto_register_field_array(proto_pppoe, hf, array_length(hf));
 867
 868 }
 869
 870 void proto_reg_handoff_pppoes(void)
 871 {
 872         dissector_handle_t pppoes_handle  =
 873             create_dissector_handle(dissect_pppoes, proto_pppoes);
 874         dissector_add("ethertype", ETHERTYPE_PPPOES, pppoes_handle);
 875
 876         /* Get a handle for the PPP dissector */
 877         ppp_handle = find_dissector("ppp");
 878 }