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 #ifdef HAVE_CONFIG_H
  21 #include <config.h>
  22 #endif
  23
  24 #include "netdissect-stdinc.h"
  25
  26 #define ND_LONGJMP_FROM_TCHECK
  27 #include "netdissect.h"
  28 #include "extract.h"
  29 #include "addrtoname.h"
  30
  31
  32 /*
  33    ETSI TS 102 636-5-1 V1.1.1 (2011-02)
  34    Intelligent Transport Systems (ITS); Vehicular Communications; GeoNetworking;
  35    Part 5: Transport Protocols; Sub-part 1: Basic Transport Protocol
  36
  37    ETSI TS 102 636-4-1 V1.1.1 (2011-06)
  38    Intelligent Transport Systems (ITS); Vehicular communications; GeoNetworking;
  39    Part 4: Geographical addressing and forwarding for point-to-point and point-to-multipoint communications;
  40    Sub-part 1: Media-Independent Functionality
  41 */
  42
  43 #define GEONET_ADDR_LEN 8
  44
  45 static const struct tok msg_type_values[] = {
  46         {   0, "CAM" },
  47         {   1, "DENM" },
  48         { 101, "TPEGM" },
  49         { 102, "TSPDM" },
  50         { 103, "VPM" },
  51         { 104, "SRM" },
  52         { 105, "SLAM" },
  53         { 106, "ecoCAM" },
  54         { 107, "ITM" },
  55         { 150, "SA" },
  56         {   0, NULL }
  57 };
  58
  59 static void
  60 print_btp_body(netdissect_options *ndo,
  61                const u_char *bp)
  62 {
  63         u_int msg_type;
  64
  65         /* Assuming ItsPduHeader */
  66         ND_PRINT("; ItsPduHeader v:%u", GET_U_1(bp));
  67
  68         msg_type = GET_U_1(bp + 1);
  69         ND_PRINT(" t:%u-%s", msg_type,
  70                  tok2str(msg_type_values, "unknown (%u)", msg_type));
  71 }
  72
  73 /* EN 302 636-5-1 V2.2.1 Section 7.2: BTP-A header */
  74 static void
  75 print_btp(netdissect_options *ndo,
  76           const u_char *bp)
  77 {
  78         ND_PRINT("; BTP Dst:%u", GET_BE_U_2(bp + 0));
  79         ND_PRINT(" Src:%u", GET_BE_U_2(bp + 2));
  80 }
  81
  82 static void
  83 print_long_pos_vector(netdissect_options *ndo,
  84                       const u_char *bp)
  85 {
  86         ND_PRINT("GN_ADDR:%s ", GET_LINKADDR_STRING(bp, LINKADDR_OTHER, GEONET_ADDR_LEN));
  87         ND_PRINT("lat:%u ", GET_BE_U_4(bp + 12));
  88         ND_PRINT("lon:%u", GET_BE_U_4(bp + 16));
  89 }
  90
  91
  92 /*
  93  * This is the top level routine of the printer.  'p' points
  94  * to the geonet header of the packet.
  95  */
  96 void
  97 geonet_print(netdissect_options *ndo, const u_char *bp, u_int length,
  98              const struct lladdr_info *src)
  99 {
 100         u_int version;
 101         u_int next_hdr;
 102         u_int hdr_type;
 103         u_int hdr_subtype;
 104         uint16_t payload_length;
 105         u_int hop_limit;
 106         const char *next_hdr_txt = "Unknown";
 107         const char *hdr_type_txt = "Unknown";
 108         int hdr_size = -1;
 109
 110         ndo->ndo_protocol = "geonet";
 111         ND_PRINT("GeoNet ");
 112         if (src != NULL)
 113                 ND_PRINT("src:%s", (src->addr_string)(ndo, src->addr));
 114         ND_PRINT("; ");
 115
 116         /* Process Common Header */
 117         if (length < 36) {
 118                 ND_PRINT(" (common header length %u < 36)", length);
 119                 goto invalid;
 120         }
 121
 122         version = GET_U_1(bp) >> 4;
 123         next_hdr = GET_U_1(bp) & 0x0f;
 124         hdr_type = GET_U_1(bp + 1) >> 4;
 125         hdr_subtype = GET_U_1(bp + 1) & 0x0f;
 126         payload_length = GET_BE_U_2(bp + 4);
 127         hop_limit = GET_U_1(bp + 7);
 128
 129         switch (next_hdr) {
 130                 case 0: next_hdr_txt = "Any"; break;
 131                 case 1: next_hdr_txt = "BTP-A"; break;
 132                 case 2: next_hdr_txt = "BTP-B"; break;
 133                 case 3: next_hdr_txt = "IPv6"; break;
 134         }
 135
 136         switch (hdr_type) {
 137                 case 0: hdr_type_txt = "Any"; break;
 138                 case 1: hdr_type_txt = "Beacon"; break;
 139                 case 2: hdr_type_txt = "GeoUnicast"; break;
 140                 case 3: switch (hdr_subtype) {
 141                                 case 0: hdr_type_txt = "GeoAnycastCircle"; break;
 142                                 case 1: hdr_type_txt = "GeoAnycastRect"; break;
 143                                 case 2: hdr_type_txt = "GeoAnycastElipse"; break;
 144                         }
 145                         break;
 146                 case 4: switch (hdr_subtype) {
 147                                 case 0: hdr_type_txt = "GeoBroadcastCircle"; break;
 148                                 case 1: hdr_type_txt = "GeoBroadcastRect"; break;
 149                                 case 2: hdr_type_txt = "GeoBroadcastElipse"; break;
 150                         }
 151                         break;
 152                 case 5: switch (hdr_subtype) {
 153                                 case 0: hdr_type_txt = "TopoScopeBcast-SH"; break;
 154                                 case 1: hdr_type_txt = "TopoScopeBcast-MH"; break;
 155                         }
 156                         break;
 157                 case 6: switch (hdr_subtype) {
 158                                 case 0: hdr_type_txt = "LocService-Request"; break;
 159                                 case 1: hdr_type_txt = "LocService-Reply"; break;
 160                         }
 161                         break;
 162         }
 163
 164         ND_PRINT("v:%u ", version);
 165         ND_PRINT("NH:%u-%s ", next_hdr, next_hdr_txt);
 166         ND_PRINT("HT:%u-%u-%s ", hdr_type, hdr_subtype, hdr_type_txt);
 167         ND_PRINT("HopLim:%u ", hop_limit);
 168         ND_PRINT("Payload:%u ", payload_length);
 169         print_long_pos_vector(ndo, bp + 8);
 170
 171         /* Skip Common Header */
 172         length -= 36;
 173         bp += 36;
 174
 175         /* Process Extended Headers */
 176         switch (hdr_type) {
 177                 case 0: /* Any */
 178                         hdr_size = 0;
 179                         break;
 180                 case 1: /* Beacon */
 181                         hdr_size = 0;
 182                         break;
 183                 case 2: /* GeoUnicast */
 184                         break;
 185                 case 3: switch (hdr_subtype) {
 186                                 case 0: /* GeoAnycastCircle */
 187                                         break;
 188                                 case 1: /* GeoAnycastRect */
 189                                         break;
 190                                 case 2: /* GeoAnycastElipse */
 191                                         break;
 192                         }
 193                         break;
 194                 case 4: switch (hdr_subtype) {
 195                                 case 0: /* GeoBroadcastCircle */
 196                                         break;
 197                                 case 1: /* GeoBroadcastRect */
 198                                         break;
 199                                 case 2: /* GeoBroadcastElipse */
 200                                         break;
 201                         }
 202                         break;
 203                 case 5: switch (hdr_subtype) {
 204                                 case 0: /* TopoScopeBcast-SH */
 205                                         hdr_size = 0;
 206                                         break;
 207                                 case 1: /* TopoScopeBcast-MH */
 208                                         hdr_size = 68 - 36;
 209                                         break;
 210                         }
 211                         break;
 212                 case 6: switch (hdr_subtype) {
 213                                 case 0: /* LocService-Request */
 214                                         break;
 215                                 case 1: /* LocService-Reply */
 216                                         break;
 217                         }
 218                         break;
 219         }
 220
 221         /* Skip Extended headers */
 222         if (hdr_size >= 0) {
 223                 if (length < (u_int)hdr_size) {
 224                         ND_PRINT(" (header size %d > %u)", hdr_size, length);
 225                         goto invalid;
 226                 }
 227                 ND_TCHECK_LEN(bp, hdr_size);
 228                 length -= hdr_size;
 229                 bp += hdr_size;
 230                 switch (next_hdr) {
 231                         case 0: /* Any */
 232                                 break;
 233                         case 1:
 234                         case 2: /* BTP A/B */
 235                                 if (length < 4) {
 236                                         ND_PRINT(" (BTP length %u < 4)", length);
 237                                         goto invalid;
 238                                 }
 239                                 print_btp(ndo, bp);
 240                                 length -= 4;
 241                                 bp += 4;
 242                                 if (length >= 2) {
 243                                         /*
 244                                          * XXX - did print_btp_body()
 245                                          * return if length < 2
 246                                          * because this is optional,
 247                                          * or was that just not
 248                                          * reporting genuine errors?
 249                                          */
 250                                         print_btp_body(ndo, bp);
 251                                 }
 252                                 break;
 253                         case 3: /* IPv6 */
 254                                 break;
 255                 }
 256         }
 257
 258         /* Print user data part */
 259         if (ndo->ndo_vflag)
 260                 ND_DEFAULTPRINT(bp, length);
 261         return;
 262
 263 invalid:
 264         nd_print_invalid(ndo);
 265         /* XXX - print the remaining data as hex? */
 266 }