The Tcpdump Group git mirrors - tcpdump/blob - print-geonet.c

   1 /*
   2  * Copyright (c) 2013 The TCPDUMP project
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that: (1) source code
   6  * distributions retain the above copyright notice and this paragraph
   7  * in its entirety, and (2) distributions including binary code include
   8  * the above copyright notice and this paragraph in its entirety in
   9  * the documentation or other materials provided with the distribution.
  10  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
  11  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
  12  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  13  * FOR A PARTICULAR PURPOSE.
  14  *
  15  * Original code by Ola Martin Lykkja (ola.lykkja@q-free.com)
  16  */
  17
  18 /* \summary: ISO CALM FAST and ETSI GeoNetworking printer */
  19
  20 #include <config.h>
  21
  22 #include "netdissect-stdinc.h"
  23
  24 #define ND_LONGJMP_FROM_TCHECK
  25 #include "netdissect.h"
  26 #include "extract.h"
  27 #include "addrtoname.h"
  28
  29
  30 /*
  31    ETSI TS 102 636-5-1 V1.1.1 (2011-02)
  32    Intelligent Transport Systems (ITS); Vehicular Communications; GeoNetworking;
  33    Part 5: Transport Protocols; Sub-part 1: Basic Transport Protocol
  34
  35    ETSI TS 102 636-4-1 V1.1.1 (2011-06)
  36    Intelligent Transport Systems (ITS); Vehicular communications; GeoNetworking;
  37    Part 4: Geographical addressing and forwarding for point-to-point and point-to-multipoint communications;
  38    Sub-part 1: Media-Independent Functionality
  39 */
  40
  41 #define GEONET_ADDR_LEN 8
  42
  43 static const struct tok msg_type_values[] = {
  44         {   0, "CAM" },
  45         {   1, "DENM" },
  46         { 101, "TPEGM" },
  47         { 102, "TSPDM" },
  48         { 103, "VPM" },
  49         { 104, "SRM" },
  50         { 105, "SLAM" },
  51         { 106, "ecoCAM" },
  52         { 107, "ITM" },
  53         { 150, "SA" },
  54         {   0, NULL }
  55 };
  56
  57 static void
  58 print_btp_body(netdissect_options *ndo,
  59                const u_char *bp)
  60 {
  61         u_int msg_type;
  62
  63         /* Assuming ItsPduHeader */
  64         ND_PRINT("; ItsPduHeader v:%u", GET_U_1(bp));
  65
  66         msg_type = GET_U_1(bp + 1);
  67         ND_PRINT(" t:%u-%s", msg_type,
  68                  tok2str(msg_type_values, "unknown (%u)", msg_type));
  69 }
  70
  71 /* EN 302 636-5-1 V2.2.1 Section 7.2: BTP-A header */
  72 static void
  73 print_btp(netdissect_options *ndo,
  74           const u_char *bp)
  75 {
  76         ND_PRINT("; BTP Dst:%u", GET_BE_U_2(bp + 0));
  77         ND_PRINT(" Src:%u", GET_BE_U_2(bp + 2));
  78 }
  79
  80 static void
  81 print_long_pos_vector(netdissect_options *ndo,
  82                       const u_char *bp)
  83 {
  84         ND_PRINT("GN_ADDR:%s ", GET_LINKADDR_STRING(bp, LINKADDR_OTHER, GEONET_ADDR_LEN));
  85         ND_PRINT("lat:%u ", GET_BE_U_4(bp + 12));
  86         ND_PRINT("lon:%u", GET_BE_U_4(bp + 16));
  87 }
  88
  89
  90 /*
  91  * This is the top level routine of the printer.  'p' points
  92  * to the geonet header of the packet.
  93  */
  94 void
  95 geonet_print(netdissect_options *ndo, const u_char *bp, u_int length,
  96              const struct lladdr_info *src)
  97 {
  98         u_int version;
  99         u_int next_hdr;
 100         u_int hdr_type;
 101         u_int hdr_subtype;
 102         uint16_t payload_length;
 103         u_int hop_limit;
 104         const char *next_hdr_txt = "Unknown";
 105         const char *hdr_type_txt = "Unknown";
 106         int hdr_size = -1;
 107
 108         ndo->ndo_protocol = "geonet";
 109         ND_PRINT("GeoNet ");
 110         if (src != NULL)
 111                 ND_PRINT("src:%s", (src->addr_string)(ndo, src->addr));
 112         ND_PRINT("; ");
 113
 114         /* Process Common Header */
 115         if (length < 36) {
 116                 ND_PRINT(" (common header length %u < 36)", length);
 117                 goto invalid;
 118         }
 119
 120         version = GET_U_1(bp) >> 4;
 121         next_hdr = GET_U_1(bp) & 0x0f;
 122         hdr_type = GET_U_1(bp + 1) >> 4;
 123         hdr_subtype = GET_U_1(bp + 1) & 0x0f;
 124         payload_length = GET_BE_U_2(bp + 4);
 125         hop_limit = GET_U_1(bp + 7);
 126
 127         switch (next_hdr) {
 128                 case 0: next_hdr_txt = "Any"; break;
 129                 case 1: next_hdr_txt = "BTP-A"; break;
 130                 case 2: next_hdr_txt = "BTP-B"; break;
 131                 case 3: next_hdr_txt = "IPv6"; break;
 132         }
 133
 134         switch (hdr_type) {
 135                 case 0: hdr_type_txt = "Any"; break;
 136                 case 1: hdr_type_txt = "Beacon"; break;
 137                 case 2: hdr_type_txt = "GeoUnicast"; break;
 138                 case 3: switch (hdr_subtype) {
 139                                 case 0: hdr_type_txt = "GeoAnycastCircle"; break;
 140                                 case 1: hdr_type_txt = "GeoAnycastRect"; break;
 141                                 case 2: hdr_type_txt = "GeoAnycastElipse"; break;
 142                         }
 143                         break;
 144                 case 4: switch (hdr_subtype) {
 145                                 case 0: hdr_type_txt = "GeoBroadcastCircle"; break;
 146                                 case 1: hdr_type_txt = "GeoBroadcastRect"; break;
 147                                 case 2: hdr_type_txt = "GeoBroadcastElipse"; break;
 148                         }
 149                         break;
 150                 case 5: switch (hdr_subtype) {
 151                                 case 0: hdr_type_txt = "TopoScopeBcast-SH"; break;
 152                                 case 1: hdr_type_txt = "TopoScopeBcast-MH"; break;
 153                         }
 154                         break;
 155                 case 6: switch (hdr_subtype) {
 156                                 case 0: hdr_type_txt = "LocService-Request"; break;
 157                                 case 1: hdr_type_txt = "LocService-Reply"; break;
 158                         }
 159                         break;
 160         }
 161
 162         ND_PRINT("v:%u ", version);
 163         ND_PRINT("NH:%u-%s ", next_hdr, next_hdr_txt);
 164         ND_PRINT("HT:%u-%u-%s ", hdr_type, hdr_subtype, hdr_type_txt);
 165         ND_PRINT("HopLim:%u ", hop_limit);
 166         ND_PRINT("Payload:%u ", payload_length);
 167         print_long_pos_vector(ndo, bp + 8);
 168
 169         /* Skip Common Header */
 170         ND_TCHECK_LEN(bp, 36);
 171         length -= 36;
 172         bp += 36;
 173
 174         /* Process Extended Headers */
 175         switch (hdr_type) {
 176                 case 0: /* Any */
 177                         hdr_size = 0;
 178                         break;
 179                 case 1: /* Beacon */
 180                         hdr_size = 0;
 181                         break;
 182                 case 2: /* GeoUnicast */
 183                         break;
 184                 case 3: switch (hdr_subtype) {
 185                                 case 0: /* GeoAnycastCircle */
 186                                         break;
 187                                 case 1: /* GeoAnycastRect */
 188                                         break;
 189                                 case 2: /* GeoAnycastElipse */
 190                                         break;
 191                         }
 192                         break;
 193                 case 4: switch (hdr_subtype) {
 194                                 case 0: /* GeoBroadcastCircle */
 195                                         break;
 196                                 case 1: /* GeoBroadcastRect */
 197                                         break;
 198                                 case 2: /* GeoBroadcastElipse */
 199                                         break;
 200                         }
 201                         break;
 202                 case 5: switch (hdr_subtype) {
 203                                 case 0: /* TopoScopeBcast-SH */
 204                                         hdr_size = 0;
 205                                         break;
 206                                 case 1: /* TopoScopeBcast-MH */
 207                                         hdr_size = 68 - 36;
 208                                         break;
 209                         }
 210                         break;
 211                 case 6: switch (hdr_subtype) {
 212                                 case 0: /* LocService-Request */
 213                                         break;
 214                                 case 1: /* LocService-Reply */
 215                                         break;
 216                         }
 217                         break;
 218         }
 219
 220         /* Skip Extended headers */
 221         if (hdr_size >= 0) {
 222                 if (length < (u_int)hdr_size) {
 223                         ND_PRINT(" (header size %d > %u)", hdr_size, length);
 224                         goto invalid;
 225                 }
 226                 ND_TCHECK_LEN(bp, hdr_size);
 227                 length -= hdr_size;
 228                 bp += hdr_size;
 229                 switch (next_hdr) {
 230                         case 0: /* Any */
 231                                 break;
 232                         case 1:
 233                         case 2: /* BTP A/B */
 234                                 if (length < 4) {
 235                                         ND_PRINT(" (BTP length %u < 4)", length);
 236                                         goto invalid;
 237                                 }
 238                                 print_btp(ndo, bp);
 239                                 length -= 4;
 240                                 bp += 4;
 241                                 if (length >= 2) {
 242                                         /*
 243                                          * XXX - did print_btp_body()
 244                                          * return if length < 2
 245                                          * because this is optional,
 246                                          * or was that just not
 247                                          * reporting genuine errors?
 248                                          */
 249                                         print_btp_body(ndo, bp);
 250                                 }
 251                                 break;
 252                         case 3: /* IPv6 */
 253                                 break;
 254                 }
 255         }
 256
 257         /* Print user data part */
 258         if (ndo->ndo_vflag)
 259                 ND_DEFAULTPRINT(bp, length);
 260         return;
 261
 262 invalid:
 263         nd_print_invalid(ndo);
 264         /* XXX - print the remaining data as hex? */
 265 }