packet-pppoe.c

   1 /* packet-pppoe.c
   2  * Routines for PPP Over Ethernet (PPPoE) packet disassembly (RFC2516)
   3  *
   4  * $Id: packet-pppoe.c,v 1.11 2000/09/11 16:24:09 gram Exp $
   5  *
   6  * Ethereal - Network traffic analyzer
   7  * By Gerald Combs <gerald@zing.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  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 #ifdef HAVE_SYS_TYPES_H
  31 # include <sys/types.h>
  32 #endif
  33
  34 #include <glib.h>
  35 #include "etypes.h"
  36 #include "packet.h"
  37 #include "packet-ppp.h"
  38 #include "strutil.h"
  39
  40 static gint ett_pppoed = -1;
  41 static gint ett_pppoed_tags = -1;
  42
  43 /* For lack of a better source, I made up the following defines. -jsj */
  44
  45 #define PPPOE_CODE_SESSION 0x00
  46 #define PPPOE_CODE_PADO 0x7
  47 #define PPPOE_CODE_PADI 0x9
  48 #define PPPOE_CODE_PADR 0x19
  49 #define PPPOE_CODE_PADS 0x65
  50 #define PPPOE_CODE_PADT 0xa7
  51
  52 #define PPPOE_TAG_EOL 0x0000
  53 #define PPPOE_TAG_SVC_NAME 0x0101
  54 #define PPPOE_TAG_AC_NAME 0x0102
  55 #define PPPOE_TAG_HOST_UNIQ 0x0103
  56 #define PPPOE_TAG_AC_COOKIE 0x0104
  57 #define PPPOE_TAG_VENDOR 0x0105
  58 #define PPPOE_TAG_RELAY_ID 0x0110
  59 #define PPPOE_TAG_SVC_ERR 0x0201
  60 #define PPPOE_TAG_AC_ERR 0x0202
  61 #define PPPOE_TAG_GENERIC_ERR 0x0203
  62
  63 static gchar *
  64 pppoecode_to_str(guint8 codetype, const char *fmt) {
  65         static const value_string code_vals[] = {
  66                 {PPPOE_CODE_SESSION, "Session Data"                             },
  67                 {PPPOE_CODE_PADO, "Active Discovery Offer (PADO)"               },
  68                 {PPPOE_CODE_PADI, "Active Discovery Initiation (PADI)"          },
  69                 {PPPOE_CODE_PADR, "Active Discovery Request (PADR)"             },
  70                 {PPPOE_CODE_PADS, "Active Discovery Session-confirmation (PADS)"},
  71                 {PPPOE_CODE_PADT, "Active Discovery Terminate (PADT)"           },
  72                 {0,     NULL                                                        } };
  73
  74                 return val_to_str(codetype, code_vals, fmt);
  75 }
  76
  77 static gchar *
  78 pppoetag_to_str(guint16 tag_type, const char *fmt) {
  79         static const value_string code_vals[] = {
  80                 {PPPOE_TAG_EOL,        "End-Of-List"       },
  81                 {PPPOE_TAG_SVC_NAME,   "Service-Name"      },
  82                 {PPPOE_TAG_AC_NAME,    "AC-Name"           },
  83                 {PPPOE_TAG_HOST_UNIQ,  "Host-Uniq"         },
  84                 {PPPOE_TAG_AC_COOKIE,  "AC-Cookie"         },
  85                 {PPPOE_TAG_VENDOR,     "Vendor-Specific"   },
  86                 {PPPOE_TAG_RELAY_ID,   "Relay-Session-Id"  },
  87                 {PPPOE_TAG_SVC_ERR,    "Service-Name-Error"},
  88                 {PPPOE_TAG_AC_ERR,     "AC-System-Error"   },
  89                 {PPPOE_TAG_GENERIC_ERR,"Generic-Error"     },
  90                 {0,                    NULL                } };
  91
  92                 return val_to_str(tag_type, code_vals, fmt);
  93 }
  94
  95
  96 static void
  97 dissect_pppoe_tags(const u_char *pd, int offset, frame_data *fd, proto_tree *tree, int payload_length) {
  98
  99         guint16 poe_tag;
 100         guint16 poe_tag_length;
 101         int tagstart;
 102
 103         proto_tree  *pppoe_tree;
 104         proto_item  *ti;
 105
 106         /* Start Decoding Here. */
 107
 108         if (tree) {
 109                 ti = proto_tree_add_text(tree, NullTVB,offset,payload_length,"PPPoE Tags");
 110                 pppoe_tree = proto_item_add_subtree(ti, ett_pppoed_tags);
 111
 112                 tagstart = offset;
 113                 while(tagstart <= payload_length-2 ) {
 114
 115                         poe_tag = pntohs(&pd[tagstart]);
 116                         poe_tag_length = pntohs(&pd[tagstart + 2]);
 117
 118                         proto_tree_add_text(pppoe_tree, NullTVB,tagstart,4,
 119                                 "Tag: %s", pppoetag_to_str(poe_tag,"Unknown (0x%02x)"));
 120
 121                         switch(poe_tag) {
 122                         case PPPOE_TAG_SVC_NAME:
 123                         case PPPOE_TAG_AC_NAME:
 124                         case PPPOE_TAG_SVC_ERR:
 125                         case PPPOE_TAG_AC_ERR:
 126                         case PPPOE_TAG_GENERIC_ERR:
 127                                 /* tag value should be interpreted as a utf-8 unterminated string.*/
 128                                 if(poe_tag_length > 0 ) {
 129                                         /* really should do some limit checking here.  :( */
 130                                         proto_tree_add_text(pppoe_tree, NullTVB,tagstart+4,poe_tag_length,
 131                                                 "  String Data: %s", format_text(&pd[tagstart+4],poe_tag_length ));
 132                                 }
 133                                 break;
 134                         default:
 135                                 if(poe_tag_length > 0 ) {
 136                                  proto_tree_add_text(pppoe_tree, NullTVB,tagstart+4,poe_tag_length,
 137                                                 "  Binary Data: (%d bytes)", poe_tag_length );
 138                                 }
 139                         }
 140
 141                         if (poe_tag == PPPOE_TAG_EOL) break;
 142
 143                         tagstart += 4 + poe_tag_length;
 144                 }
 145         }
 146 }
 147
 148 static void
 149 dissect_pppoed(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {
 150         guint8 pppoe_ver;
 151         guint8 pppoe_type;
 152         guint8  pppoe_code;
 153         guint16 pppoe_session_id;
 154         guint16 pppoe_length;
 155
 156         proto_tree  *pppoe_tree;
 157         proto_item  *ti;
 158
 159         /* Start Decoding Here. */
 160         pppoe_ver = (guint8) ((pd[offset] >> 4) & 0x0f);
 161         pppoe_type = (guint8) (pd[offset] & 0x0f);
 162         pppoe_code = (guint8) pd[offset + 1];
 163         pppoe_session_id = pntohs(&pd[offset + 2]);
 164         pppoe_length = pntohs(&pd[offset + 4]);
 165
 166         if (check_col(fd, COL_PROTOCOL)) {
 167                 col_add_str(fd,COL_PROTOCOL, "PPPoED");
 168         }
 169
 170         if (check_col(fd,COL_INFO)) {
 171                 col_add_fstr(fd,COL_INFO,pppoecode_to_str(pppoe_code,"Unknown code (0x%02x)"));
 172         }
 173
 174         if (tree) {
 175                 ti = proto_tree_add_text(tree, NullTVB,offset,pppoe_length+6,"PPPoE Discovery");
 176                 pppoe_tree = proto_item_add_subtree(ti, ett_pppoed);
 177                 proto_tree_add_text(pppoe_tree, NullTVB,offset,1,
 178                         "Version: %d", pppoe_ver);
 179                 proto_tree_add_text(pppoe_tree, NullTVB,offset,1,
 180                         "Type: %d", pppoe_type);
 181                 proto_tree_add_text(pppoe_tree, NullTVB,offset+1,1,
 182                         "Code: %s", pppoecode_to_str(pppoe_code,"Unknown (0x%02x)"));
 183                 proto_tree_add_text(pppoe_tree, NullTVB,offset+2,2,
 184                         "Session ID: %04x", pppoe_session_id);
 185                 proto_tree_add_text(pppoe_tree, NullTVB,offset+4,2,
 186                         "Payload Length: %d", pppoe_length);
 187         }
 188         dissect_pppoe_tags(pd,offset+6,fd,tree,offset+6+pppoe_length);
 189
 190 }
 191
 192 static void
 193 dissect_pppoes(const u_char *pd, int offset, frame_data *fd, proto_tree *tree) {
 194         guint8 pppoe_ver;
 195         guint8 pppoe_type;
 196         guint8  pppoe_code;
 197         guint16 pppoe_session_id;
 198         guint16 pppoe_length;
 199
 200         proto_tree  *pppoe_tree;
 201         proto_item  *ti;
 202
 203         /* Start Decoding Here. */
 204         pppoe_ver = (guint8) ((pd[offset] >> 4) & 0x0f);
 205         pppoe_type = (guint8) (pd[offset] & 0x0f);
 206         pppoe_code = (guint8) pd[offset + 1];
 207         pppoe_session_id = pntohs(&pd[offset + 2]);
 208         pppoe_length = pntohs(&pd[offset + 4]);
 209
 210         if (check_col(fd, COL_PROTOCOL)) {
 211                 col_add_str(fd,COL_PROTOCOL, "PPPoES");
 212         }
 213
 214         if (check_col(fd,COL_INFO)) {
 215                 col_add_fstr(fd,COL_INFO,pppoecode_to_str(pppoe_code,"Unknown code (0x%02x)"));
 216         }
 217
 218         if (tree) {
 219                 ti = proto_tree_add_text(tree, NullTVB,offset,pppoe_length+6,"PPPoE Session");
 220                 pppoe_tree = proto_item_add_subtree(ti, ett_pppoed);
 221                 proto_tree_add_text(pppoe_tree, NullTVB,offset,1,
 222                         "Version: %d", pppoe_ver);
 223                 proto_tree_add_text(pppoe_tree, NullTVB,offset,1,
 224                         "Type: %d", pppoe_type);
 225                 proto_tree_add_text(pppoe_tree, NullTVB,offset+1,1,
 226                         "Code: %s", pppoecode_to_str(pppoe_code,"Unknown (0x%02x)"));
 227                 proto_tree_add_text(pppoe_tree, NullTVB,offset+2,2,
 228                         "Session ID: %04x", pppoe_session_id);
 229                 proto_tree_add_text(pppoe_tree, NullTVB,offset+4,2,
 230                         "Payload Length: %d", pppoe_length);
 231         }
 232         /* dissect_ppp is apparently done as a 'top level' dissector,
 233                 * so this doesn't work:
 234                 * dissect_ppp(pd,offset+6,fd,tree);
 235                 * Im gonna try fudging it.
 236                 */
 237
 238         dissect_payload_ppp(pd,offset+6,fd,tree);
 239 }
 240
 241 void
 242 proto_register_pppoed(void)
 243 {
 244         static gint *ett[] = {
 245                 &ett_pppoed,
 246                 &ett_pppoed_tags,
 247         };
 248
 249         proto_register_subtree_array(ett, array_length(ett));
 250 }
 251
 252 void
 253 proto_reg_handoff_pppoe(void)
 254 {
 255         old_dissector_add("ethertype", ETHERTYPE_PPPOED, dissect_pppoed);
 256         old_dissector_add("ethertype", ETHERTYPE_PPPOES, dissect_pppoes);
 257 }