epan/dissectors/packet-roofnet.c

   1 /* packet-roofnet.c
   2  * Routines for roofnet dissection
   3  * Copyright 2006, Sebastien Tandel (sebastien@tandel.be)
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-or-later
  10  */
  11
  12 #include "config.h"
  13
  14 #include <epan/packet.h>
  15 #include <epan/addr_resolv.h>
  16 #include <epan/expert.h>
  17 #include <epan/ptvcursor.h>
  18
  19
  20 /* roofnet packet type constants */
  21 #define ROOFNET_PT_QUERY 0x01
  22 #define ROOFNET_PT_REPLY 0x02
  23 #define ROOFNET_PT_DATA 0x04
  24 #define ROOFNET_PT_GATEWAY 0x08
  25 static const value_string roofnet_pt_vals[] = {
  26   { ROOFNET_PT_QUERY, "Query" },
  27   { ROOFNET_PT_REPLY, "Reply" },
  28   { ROOFNET_PT_DATA, "Data" },
  29   { ROOFNET_PT_GATEWAY, "Gateway" },
  30   { 0, NULL }
  31 };
  32
  33 /* roofnet flag bit masks */
  34 #define ROOFNET_FLAG_ERROR (1<<0)
  35 #define ROOFNET_FLAG_UPDATE (1<<1)
  36 #define ROOFNET_FLAG_LAYER2 (1<<9)
  37 #define ROOFNET_FLAG_RESERVED 0xFDFC
  38 #define ROOFNET_FLAG_MASK (ROOFNET_FLAG_ERROR | ROOFNET_FLAG_UPDATE | ROOFNET_FLAG_LAYER2)
  39
  40 /* header length */
  41 #define ROOFNET_HEADER_LENGTH 160
  42 /* roofnet max length */
  43 /* may change with time */
  44 #define ROOFNET_MAX_LENGTH 400
  45 /* Roofnet Link Description Length
  46  * which is 6 fields of 4 bytes */
  47 #define ROOFNET_LINK_DESCRIPTION_LENGTH 6*4
  48
  49 /* offset constants */
  50 #define ROOFNET_OFFSET_TYPE 1
  51 #define ROOFNET_OFFSET_NLINKS 2
  52 #define ROOFNET_OFFSET_DATA_LENGTH 10
  53
  54 /* offset relative to a link section of roofnet */
  55 #define ROOFNET_LINK_OFFSET_SRC 0
  56 #define ROOFNET_LINK_OFFSET_DST 20
  57 /* roofnet link fields length */
  58 #define ROOFNET_LINK_LEN 24
  59
  60 /* forward reference */
  61 void proto_register_roofnet(void);
  62 void proto_reg_handoff_roofnet(void);
  63
  64 static dissector_handle_t roofnet_handle;
  65 static dissector_handle_t ip_handle;
  66 static dissector_handle_t eth_withoutfcs_handle;
  67 static int proto_roofnet;
  68
  69 /* hf fields for the header of roofnet */
  70 static int hf_roofnet_version;
  71 static int hf_roofnet_type;
  72 static int hf_roofnet_nlinks;
  73 static int hf_roofnet_next;
  74 static int hf_roofnet_ttl;
  75 static int hf_roofnet_cksum;
  76 static int hf_roofnet_flags;
  77 static int hf_roofnet_flags_error;
  78 static int hf_roofnet_flags_update;
  79 static int hf_roofnet_flags_layer2;
  80 static int hf_roofnet_flags_reserved;
  81 static int hf_roofnet_data_length;
  82 static int hf_roofnet_query_dst;
  83 static int hf_roofnet_seq;
  84 /* static int hf_roofnet_links; */
  85 static int hf_roofnet_link_src;
  86 static int hf_roofnet_link_forward;
  87 static int hf_roofnet_link_rev;
  88 static int hf_roofnet_link_seq;
  89 static int hf_roofnet_link_age;
  90 static int hf_roofnet_link_dst;
  91
  92 static int * const flag_list[] = {
  93     &hf_roofnet_flags_error,
  94     &hf_roofnet_flags_update,
  95     &hf_roofnet_flags_layer2,
  96     &hf_roofnet_flags_reserved,
  97     NULL
  98 };
  99
 100
 101 static int ett_roofnet;
 102 static int ett_roofnet_flags;
 103 static int ett_roofnet_link;
 104
 105 static expert_field ei_roofnet_too_many_links;
 106 static expert_field ei_roofnet_too_much_data;
 107
 108 /*
 109  * dissect the header of roofnet
 110  */
 111 static uint16_t dissect_roofnet_header(proto_tree *tree, packet_info *pinfo, tvbuff_t *tvb, unsigned *offset)
 112 {
 113   uint16_t flags;
 114   ptvcursor_t *cursor = ptvcursor_new(pinfo->pool, tree, tvb, *offset);
 115
 116   ptvcursor_add(cursor, hf_roofnet_version, 1, ENC_BIG_ENDIAN);
 117   ptvcursor_add(cursor, hf_roofnet_type, 1, ENC_BIG_ENDIAN);
 118   ptvcursor_add(cursor, hf_roofnet_nlinks, 1, ENC_BIG_ENDIAN);
 119   ptvcursor_add(cursor, hf_roofnet_next, 1, ENC_BIG_ENDIAN);
 120   ptvcursor_add(cursor, hf_roofnet_ttl, 2, ENC_BIG_ENDIAN);
 121   proto_tree_add_checksum(ptvcursor_tree(cursor), ptvcursor_tvbuff(cursor), ptvcursor_current_offset(cursor),
 122                           hf_roofnet_cksum, -1, NULL, NULL, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);
 123   ptvcursor_advance(cursor, 2);
 124   flags = tvb_get_ntohs(ptvcursor_tvbuff(cursor), ptvcursor_current_offset(cursor));
 125   proto_tree_add_bitmask(ptvcursor_tree(cursor), ptvcursor_tvbuff(cursor), ptvcursor_current_offset(cursor),
 126                           hf_roofnet_flags, ett_roofnet_flags, flag_list, ENC_BIG_ENDIAN);
 127   ptvcursor_advance(cursor, 2);
 128   ptvcursor_add(cursor, hf_roofnet_data_length, 2, ENC_BIG_ENDIAN);
 129   ptvcursor_add(cursor, hf_roofnet_query_dst, 4, ENC_BIG_ENDIAN);
 130   ptvcursor_add(cursor, hf_roofnet_seq, 4, ENC_BIG_ENDIAN);
 131
 132   *offset = ptvcursor_current_offset(cursor);
 133   ptvcursor_free(cursor);
 134
 135   return flags;
 136 }
 137
 138 /*
 139  * dissect the description of link in roofnet
 140  */
 141 static void dissect_roofnet_link(proto_tree *tree, packet_info *pinfo, tvbuff_t *tvb, unsigned *offset, unsigned link)
 142 {
 143   proto_tree *subtree = NULL;
 144
 145   ptvcursor_t *cursor = NULL;
 146
 147   uint32_t addr_src = 0;
 148   uint32_t addr_dst = 0;
 149
 150   addr_src = tvb_get_ipv4(tvb, *offset + ROOFNET_LINK_OFFSET_SRC);
 151   addr_dst = tvb_get_ipv4(tvb, *offset + ROOFNET_LINK_OFFSET_DST);
 152
 153   subtree = proto_tree_add_subtree_format(tree, tvb, *offset, ROOFNET_LINK_LEN,
 154                                           ett_roofnet_link, NULL, "link: %u, src: %s, dst: %s",
 155                                           link,
 156                                           get_hostname(addr_src),
 157                                           get_hostname(addr_dst));
 158
 159   proto_tree_add_ipv4(subtree, hf_roofnet_link_src, tvb, *offset, 4, addr_src);
 160   *offset += 4;
 161
 162   cursor = ptvcursor_new(pinfo->pool, subtree, tvb, *offset);
 163
 164   ptvcursor_add(cursor, hf_roofnet_link_forward, 4, ENC_BIG_ENDIAN);
 165   ptvcursor_add(cursor, hf_roofnet_link_rev, 4, ENC_BIG_ENDIAN);
 166   ptvcursor_add(cursor, hf_roofnet_link_seq, 4, ENC_BIG_ENDIAN);
 167   ptvcursor_add(cursor, hf_roofnet_link_age, 4, ENC_BIG_ENDIAN);
 168
 169   *offset = ptvcursor_current_offset(cursor);
 170   ptvcursor_free(cursor);
 171
 172   proto_tree_add_ipv4(subtree, hf_roofnet_link_dst, tvb, *offset, 4, addr_dst);
 173   /* don't increment offset here because the dst of this link is the src of the next one */
 174 }
 175
 176 /*
 177  * dissect the data in roofnet
 178  */
 179 static void dissect_roofnet_data(proto_tree *tree, tvbuff_t *tvb, packet_info * pinfo, int offset, uint16_t flags)
 180 {
 181   uint16_t roofnet_datalen = 0;
 182   uint16_t remaining_datalen = 0;
 183
 184   roofnet_datalen = tvb_get_ntohs(tvb, ROOFNET_OFFSET_DATA_LENGTH);
 185   remaining_datalen = tvb_reported_length_remaining(tvb, offset);
 186
 187
 188   /* dissect on remaining_datalen */
 189    if (roofnet_datalen < remaining_datalen)
 190      proto_tree_add_expert_format(tree, pinfo, &ei_roofnet_too_much_data, tvb, offset, roofnet_datalen,
 191                                   "[More payload data (%u) than told by Roofnet (%u)]",
 192                                   remaining_datalen, roofnet_datalen);
 193
 194   if (roofnet_datalen == 0)
 195     return;
 196
 197   /* dissect payload */
 198   if (flags & ROOFNET_FLAG_LAYER2) {
 199     /* ethernet frame is padded with 2 bytes at the start */
 200     call_dissector(eth_withoutfcs_handle, tvb_new_subset_remaining(tvb, offset+2), pinfo, tree);
 201   } else {
 202     call_dissector(ip_handle, tvb_new_subset_remaining(tvb, offset), pinfo, tree);
 203   }
 204
 205 }
 206
 207 /*
 208  * entry point of the roofnet dissector
 209  */
 210 static int dissect_roofnet(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 211 {
 212   proto_item * it;
 213   proto_tree * roofnet_tree;
 214   unsigned offset = 0;
 215
 216   uint8_t roofnet_msg_type = 0;
 217   uint8_t roofnet_nlinks = 0;
 218   uint8_t nlink = 1;
 219   uint16_t flags;
 220
 221   col_set_str(pinfo->cinfo, COL_PROTOCOL, "Roofnet");
 222
 223   roofnet_msg_type = tvb_get_uint8(tvb, ROOFNET_OFFSET_TYPE);
 224   /* Clear out stuff in the info column */
 225   col_add_fstr(pinfo->cinfo, COL_INFO, "Message Type: %s",
 226                val_to_str(roofnet_msg_type, roofnet_pt_vals, "Unknown (%d)"));
 227
 228   it = proto_tree_add_item(tree, proto_roofnet, tvb, offset, -1, ENC_NA);
 229   roofnet_tree = proto_item_add_subtree(it, ett_roofnet);
 230
 231   flags = dissect_roofnet_header(roofnet_tree, pinfo, tvb, &offset);
 232
 233   roofnet_nlinks = tvb_get_uint8(tvb, ROOFNET_OFFSET_NLINKS);
 234   /* Check that we do not have a malformed roofnet packet */
 235   if ((roofnet_nlinks*6*4)+ROOFNET_HEADER_LENGTH > ROOFNET_MAX_LENGTH) {
 236     expert_add_info_format(pinfo, it, &ei_roofnet_too_many_links, "Too many links (%u)", roofnet_nlinks);
 237     return tvb_captured_length(tvb);
 238   }
 239
 240   for (; roofnet_nlinks > 0; roofnet_nlinks--) {
 241     /* Do we have enough buffer to decode the next link ? */
 242     if (tvb_reported_length_remaining(tvb, offset) < ROOFNET_LINK_DESCRIPTION_LENGTH)
 243       return offset;
 244     dissect_roofnet_link(roofnet_tree, pinfo, tvb, &offset, nlink++);
 245   }
 246
 247   dissect_roofnet_data(tree, tvb, pinfo, offset+4, flags);
 248   return tvb_captured_length(tvb);
 249 }
 250
 251 void proto_register_roofnet(void)
 252 {
 253   static hf_register_info hf[] = {
 254     /* Roofnet Header */
 255     { &hf_roofnet_version,
 256       { "Version", "roofnet.version",
 257       FT_UINT8, BASE_DEC, NULL, 0x0, "Roofnet Version", HFILL }
 258     },
 259
 260     { &hf_roofnet_type,
 261       { "Type", "roofnet.type",
 262         FT_UINT8, BASE_DEC, VALS(roofnet_pt_vals), 0x0, "Roofnet Message Type", HFILL }
 263     },
 264
 265     { &hf_roofnet_nlinks,
 266       { "Number of Links", "roofnet.nlinks",
 267         FT_UINT8, BASE_DEC, NULL, 0x0, "Roofnet Number of Links", HFILL }
 268     },
 269
 270     { &hf_roofnet_next,
 271       { "Next Link", "roofnet.next",
 272         FT_UINT8, BASE_DEC, NULL, 0x0, "Roofnet Next Link to Use", HFILL }
 273     },
 274
 275     { &hf_roofnet_ttl,
 276       { "Time To Live", "roofnet.ttl",
 277         FT_UINT16, BASE_DEC, NULL, 0x0, "Roofnet Time to Live", HFILL }
 278     },
 279
 280     { &hf_roofnet_cksum,
 281       { "Checksum", "roofnet.cksum",
 282         FT_UINT16, BASE_DEC, NULL, 0x0, "Roofnet Header Checksum", HFILL }
 283     },
 284
 285     { &hf_roofnet_flags,
 286       { "Flags", "roofnet.flags",
 287         FT_UINT16, BASE_HEX, NULL, 0x0, "Roofnet flags", HFILL }
 288     },
 289
 290     { &hf_roofnet_flags_error,
 291       { "Roofnet Error", "roofnet.flags.error",
 292         FT_BOOLEAN, 16, NULL, ROOFNET_FLAG_ERROR, NULL, HFILL }
 293     },
 294
 295     { &hf_roofnet_flags_update,
 296       { "Roofnet Update", "roofnet.flags.update",
 297         FT_BOOLEAN, 16, NULL, ROOFNET_FLAG_UPDATE, NULL, HFILL }
 298     },
 299
 300     { &hf_roofnet_flags_layer2,
 301       { "Roofnet Layer 2", "roofnet.flags.layer2",
 302         FT_BOOLEAN, 16, NULL, ROOFNET_FLAG_LAYER2, NULL, HFILL }
 303     },
 304
 305     { &hf_roofnet_flags_reserved,
 306       { "Roofnet Reserved", "roofnet.flags.reserved",
 307         FT_BOOLEAN, 16, NULL, ROOFNET_FLAG_RESERVED, NULL, HFILL }
 308     },
 309
 310     { &hf_roofnet_data_length,
 311       { "Data Length", "roofnet.datalength",
 312         FT_UINT16, BASE_DEC, NULL, 0x0, "Data Payload Length", HFILL }
 313     },
 314
 315     { &hf_roofnet_query_dst,
 316       { "Query Dst", "roofnet.querydst",
 317         FT_IPv4, BASE_NONE, NULL, 0x0, "Roofnet Query Destination", HFILL }
 318     },
 319
 320     { &hf_roofnet_seq,
 321       { "Seq", "roofnet.seq",
 322         FT_UINT32, BASE_DEC, NULL, 0x0, "Roofnet Sequential Number", HFILL }
 323     },
 324
 325 #if 0
 326     { &hf_roofnet_links,
 327       { "Links", "roofnet.links",
 328       FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }
 329     },
 330 #endif
 331
 332     { &hf_roofnet_link_src,
 333       { "Source IP", "roofnet.link.src",
 334       FT_IPv4, BASE_NONE, NULL, 0x0, "Roofnet Message Source", HFILL }
 335     },
 336
 337     { &hf_roofnet_link_forward,
 338       { "Forward", "roofnet.link.forward",
 339         FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }
 340     },
 341
 342     { &hf_roofnet_link_rev,
 343       { "Rev", "roofnet.link.rev",
 344         FT_UINT32, BASE_DEC, NULL, 0x0, "Revision Number", HFILL }
 345     },
 346
 347     { &hf_roofnet_link_seq,
 348       { "Seq", "roofnet.link.seq",
 349         FT_UINT32, BASE_DEC, NULL, 0x0, "Link Sequential Number", HFILL }
 350     },
 351
 352     { &hf_roofnet_link_age,
 353       { "Age", "roofnet.link.age",
 354         FT_UINT32, BASE_DEC, NULL, 0x0, "Information Age", HFILL }
 355     },
 356
 357     { &hf_roofnet_link_dst,
 358       { "Dst IP", "roofnet.link.dst",
 359         FT_IPv4, BASE_NONE, NULL, 0x0, "Roofnet Message Destination", HFILL }
 360     }
 361   };
 362
 363   /* setup protocol subtree array */
 364   static int *ett[] = {
 365     &ett_roofnet,
 366     &ett_roofnet_flags,
 367     &ett_roofnet_link
 368   };
 369
 370   static ei_register_info ei[] = {
 371      { &ei_roofnet_too_many_links, { "roofnet.too_many_links", PI_MALFORMED, PI_ERROR, "Too many links", EXPFILL }},
 372      { &ei_roofnet_too_much_data, { "roofnet.too_much_data", PI_MALFORMED, PI_ERROR, "More payload data than told by Roofnet", EXPFILL }},
 373   };
 374
 375   expert_module_t* expert_roofnet;
 376
 377   proto_roofnet = proto_register_protocol("Roofnet Protocol", "Roofnet", "roofnet");
 378
 379   proto_register_field_array(proto_roofnet, hf, array_length(hf));
 380   proto_register_subtree_array(ett, array_length(ett));
 381   expert_roofnet = expert_register_protocol(proto_roofnet);
 382   expert_register_field_array(expert_roofnet, ei, array_length(ei));
 383
 384   roofnet_handle = register_dissector("roofnet", dissect_roofnet, proto_roofnet);
 385 }
 386
 387
 388 void proto_reg_handoff_roofnet(void)
 389 {
 390   /* Until now there is no other option than having an IPv4 payload (maybe
 391    * extended one day to IPv6 or other?) */
 392   ip_handle = find_dissector_add_dependency("ip", proto_roofnet);
 393   eth_withoutfcs_handle = find_dissector_add_dependency("eth_withoutfcs", proto_roofnet);
 394   /* I did not put the type numbers in the ethertypes.h as they only are
 395    * experimental and not official */
 396   dissector_add_uint("ethertype", 0x0641, roofnet_handle);
 397   dissector_add_uint("ethertype", 0x0643, roofnet_handle);
 398   dissector_add_uint("ethertype", 0x0644, roofnet_handle);
 399   dissector_add_uint("ethertype", 0x0645, roofnet_handle);
 400 }
 401
 402 /*
 403  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 404  *
 405  * Local Variables:
 406  * c-basic-offset: 2
 407  * tab-width: 8
 408  * indent-tabs-mode: nil
 409  * End:
 410  *
 411  * ex: set shiftwidth=2 tabstop=8 expandtab:
 412  * :indentSize=2:tabSize=8:noTabs=true:
 413  */