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

   1 /*
   2  * Copyright (c) 1991, 1992, 1993, 1994, 1995, 1996
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms are permitted
   6  * provided that the above copyright notice and this paragraph are
   7  * duplicated in all such forms and that any documentation,
   8  * advertising materials, and other materials related to such
   9  * distribution and use acknowledge that the software was developed
  10  * by the University of California, Lawrence Berkeley Laboratory,
  11  * Berkeley, CA.  The name of the University may not be used to
  12  * endorse or promote products derived from this software without
  13  * specific prior written permission.
  14  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  17  *
  18  * Initial contribution from Jeff Honig (jch@MITCHELL.CIT.CORNELL.EDU).
  19  */
  20
  21 /* \summary: Exterior Gateway Protocol (EGP) printer */
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include "config.h"
  25 #endif
  26
  27 #include <netdissect-stdinc.h>
  28
  29 #include "netdissect.h"
  30 #include "addrtoname.h"
  31 #include "extract.h"
  32
  33 struct egp_packet {
  34         uint8_t  egp_version;
  35 #define EGP_VERSION     2
  36         uint8_t  egp_type;
  37 #define  EGPT_ACQUIRE   3
  38 #define  EGPT_REACH     5
  39 #define  EGPT_POLL      2
  40 #define  EGPT_UPDATE    1
  41 #define  EGPT_ERROR     8
  42         uint8_t  egp_code;
  43 #define  EGPC_REQUEST   0
  44 #define  EGPC_CONFIRM   1
  45 #define  EGPC_REFUSE    2
  46 #define  EGPC_CEASE     3
  47 #define  EGPC_CEASEACK  4
  48 #define  EGPC_HELLO     0
  49 #define  EGPC_HEARDU    1
  50         uint8_t  egp_status;
  51 #define  EGPS_UNSPEC    0
  52 #define  EGPS_ACTIVE    1
  53 #define  EGPS_PASSIVE   2
  54 #define  EGPS_NORES     3
  55 #define  EGPS_ADMIN     4
  56 #define  EGPS_GODOWN    5
  57 #define  EGPS_PARAM     6
  58 #define  EGPS_PROTO     7
  59 #define  EGPS_INDET     0
  60 #define  EGPS_UP        1
  61 #define  EGPS_DOWN      2
  62 #define  EGPS_UNSOL     0x80
  63         uint16_t  egp_checksum;
  64         uint16_t  egp_as;
  65         uint16_t  egp_sequence;
  66         union {
  67                 uint16_t  egpu_hello;
  68                 uint8_t egpu_gws[2];
  69                 uint16_t  egpu_reason;
  70 #define  EGPR_UNSPEC    0
  71 #define  EGPR_BADHEAD   1
  72 #define  EGPR_BADDATA   2
  73 #define  EGPR_NOREACH   3
  74 #define  EGPR_XSPOLL    4
  75 #define  EGPR_NORESP    5
  76 #define  EGPR_UVERSION  6
  77         } egp_handg;
  78 #define  egp_hello  egp_handg.egpu_hello
  79 #define  egp_intgw  egp_handg.egpu_gws[0]
  80 #define  egp_extgw  egp_handg.egpu_gws[1]
  81 #define  egp_reason  egp_handg.egpu_reason
  82         union {
  83                 uint16_t  egpu_poll;
  84                 uint32_t egpu_sourcenet;
  85         } egp_pands;
  86 #define  egp_poll  egp_pands.egpu_poll
  87 #define  egp_sourcenet  egp_pands.egpu_sourcenet
  88 };
  89
  90 static const char *egp_acquire_codes[] = {
  91         "request",
  92         "confirm",
  93         "refuse",
  94         "cease",
  95         "cease_ack"
  96 };
  97
  98 static const char *egp_acquire_status[] = {
  99         "unspecified",
 100         "active_mode",
 101         "passive_mode",
 102         "insufficient_resources",
 103         "administratively_prohibited",
 104         "going_down",
 105         "parameter_violation",
 106         "protocol_violation"
 107 };
 108
 109 static const char *egp_reach_codes[] = {
 110         "hello",
 111         "i-h-u"
 112 };
 113
 114 static const char *egp_status_updown[] = {
 115         "indeterminate",
 116         "up",
 117         "down"
 118 };
 119
 120 static const char *egp_reasons[] = {
 121         "unspecified",
 122         "bad_EGP_header_format",
 123         "bad_EGP_data_field_format",
 124         "reachability_info_unavailable",
 125         "excessive_polling_rate",
 126         "no_response",
 127         "unsupported_version"
 128 };
 129
 130 static void
 131 egpnrprint(netdissect_options *ndo,
 132            register const struct egp_packet *egp, u_int length)
 133 {
 134         register const uint8_t *cp;
 135         uint32_t addr;
 136         register uint32_t net;
 137         register u_int netlen;
 138         int gateways, distances, networks;
 139         int t_gateways;
 140         const char *comma;
 141
 142         addr = egp->egp_sourcenet;
 143         if (IN_CLASSA(addr)) {
 144                 net = addr & IN_CLASSA_NET;
 145                 netlen = 1;
 146         } else if (IN_CLASSB(addr)) {
 147                 net = addr & IN_CLASSB_NET;
 148                 netlen = 2;
 149         } else if (IN_CLASSC(addr)) {
 150                 net = addr & IN_CLASSC_NET;
 151                 netlen = 3;
 152         } else {
 153                 net = 0;
 154                 netlen = 0;
 155         }
 156         cp = (const uint8_t *)(egp + 1);
 157         length -= sizeof(*egp);
 158
 159         t_gateways = egp->egp_intgw + egp->egp_extgw;
 160         for (gateways = 0; gateways < t_gateways; ++gateways) {
 161                 /* Pickup host part of gateway address */
 162                 addr = 0;
 163                 if (length < 4 - netlen)
 164                         goto trunc;
 165                 ND_TCHECK2(cp[0], 4 - netlen);
 166                 switch (netlen) {
 167
 168                 case 1:
 169                         addr = *cp++;
 170                         /* fall through */
 171                 case 2:
 172                         addr = (addr << 8) | *cp++;
 173                         /* fall through */
 174                 case 3:
 175                         addr = (addr << 8) | *cp++;
 176                 }
 177                 addr |= net;
 178                 length -= 4 - netlen;
 179                 if (length < 1)
 180                         goto trunc;
 181                 ND_TCHECK2(cp[0], 1);
 182                 distances = *cp++;
 183                 length--;
 184                 ND_PRINT((ndo, " %s %s ",
 185                        gateways < (int)egp->egp_intgw ? "int" : "ext",
 186                        ipaddr_string(ndo, &addr)));
 187
 188                 comma = "";
 189                 ND_PRINT((ndo, "("));
 190                 while (--distances >= 0) {
 191                         if (length < 2)
 192                                 goto trunc;
 193                         ND_TCHECK2(cp[0], 2);
 194                         ND_PRINT((ndo, "%sd%d:", comma, (int)*cp++));
 195                         comma = ", ";
 196                         networks = *cp++;
 197                         length -= 2;
 198                         while (--networks >= 0) {
 199                                 /* Pickup network number */
 200                                 if (length < 1)
 201                                         goto trunc;
 202                                 ND_TCHECK2(cp[0], 1);
 203                                 addr = (uint32_t)*cp++ << 24;
 204                                 length--;
 205                                 if (IN_CLASSB(addr)) {
 206                                         if (length < 1)
 207                                                 goto trunc;
 208                                         ND_TCHECK2(cp[0], 1);
 209                                         addr |= (uint32_t)*cp++ << 16;
 210                                         length--;
 211                                 } else if (!IN_CLASSA(addr)) {
 212                                         if (length < 2)
 213                                                 goto trunc;
 214                                         ND_TCHECK2(cp[0], 2);
 215                                         addr |= (uint32_t)*cp++ << 16;
 216                                         addr |= (uint32_t)*cp++ << 8;
 217                                         length -= 2;
 218                                 }
 219                                 ND_PRINT((ndo, " %s", ipaddr_string(ndo, &addr)));
 220                         }
 221                 }
 222                 ND_PRINT((ndo, ")"));
 223         }
 224         return;
 225 trunc:
 226         ND_PRINT((ndo, "[|]"));
 227 }
 228
 229 void
 230 egp_print(netdissect_options *ndo,
 231           register const uint8_t *bp, register u_int length)
 232 {
 233         register const struct egp_packet *egp;
 234         register int status;
 235         register int code;
 236         register int type;
 237
 238         egp = (const struct egp_packet *)bp;
 239         if (length < sizeof(*egp) || !ND_TTEST(*egp)) {
 240                 ND_PRINT((ndo, "[|egp]"));
 241                 return;
 242         }
 243
 244         if (!ndo->ndo_vflag) {
 245             ND_PRINT((ndo, "EGPv%u, AS %u, seq %u, length %u",
 246                    egp->egp_version,
 247                    EXTRACT_16BITS(&egp->egp_as),
 248                    EXTRACT_16BITS(&egp->egp_sequence),
 249                    length));
 250             return;
 251         } else
 252             ND_PRINT((ndo, "EGPv%u, length %u",
 253                    egp->egp_version,
 254                    length));
 255
 256         if (egp->egp_version != EGP_VERSION) {
 257                 ND_PRINT((ndo, "[version %d]", egp->egp_version));
 258                 return;
 259         }
 260
 261         type = egp->egp_type;
 262         code = egp->egp_code;
 263         status = egp->egp_status;
 264
 265         switch (type) {
 266         case EGPT_ACQUIRE:
 267                 ND_PRINT((ndo, " acquire"));
 268                 switch (code) {
 269                 case EGPC_REQUEST:
 270                 case EGPC_CONFIRM:
 271                         ND_PRINT((ndo, " %s", egp_acquire_codes[code]));
 272                         switch (status) {
 273                         case EGPS_UNSPEC:
 274                         case EGPS_ACTIVE:
 275                         case EGPS_PASSIVE:
 276                                 ND_PRINT((ndo, " %s", egp_acquire_status[status]));
 277                                 break;
 278
 279                         default:
 280                                 ND_PRINT((ndo, " [status %d]", status));
 281                                 break;
 282                         }
 283                         ND_PRINT((ndo, " hello:%d poll:%d",
 284                                EXTRACT_16BITS(&egp->egp_hello),
 285                                EXTRACT_16BITS(&egp->egp_poll)));
 286                         break;
 287
 288                 case EGPC_REFUSE:
 289                 case EGPC_CEASE:
 290                 case EGPC_CEASEACK:
 291                         ND_PRINT((ndo, " %s", egp_acquire_codes[code]));
 292                         switch (status ) {
 293                         case EGPS_UNSPEC:
 294                         case EGPS_NORES:
 295                         case EGPS_ADMIN:
 296                         case EGPS_GODOWN:
 297                         case EGPS_PARAM:
 298                         case EGPS_PROTO:
 299                                 ND_PRINT((ndo, " %s", egp_acquire_status[status]));
 300                                 break;
 301
 302                         default:
 303                                 ND_PRINT((ndo, "[status %d]", status));
 304                                 break;
 305                         }
 306                         break;
 307
 308                 default:
 309                         ND_PRINT((ndo, "[code %d]", code));
 310                         break;
 311                 }
 312                 break;
 313
 314         case EGPT_REACH:
 315                 switch (code) {
 316
 317                 case EGPC_HELLO:
 318                 case EGPC_HEARDU:
 319                         ND_PRINT((ndo, " %s", egp_reach_codes[code]));
 320                         if (status <= EGPS_DOWN)
 321                                 ND_PRINT((ndo, " state:%s", egp_status_updown[status]));
 322                         else
 323                                 ND_PRINT((ndo, " [status %d]", status));
 324                         break;
 325
 326                 default:
 327                         ND_PRINT((ndo, "[reach code %d]", code));
 328                         break;
 329                 }
 330                 break;
 331
 332         case EGPT_POLL:
 333                 ND_PRINT((ndo, " poll"));
 334                 if (egp->egp_status <= EGPS_DOWN)
 335                         ND_PRINT((ndo, " state:%s", egp_status_updown[status]));
 336                 else
 337                         ND_PRINT((ndo, " [status %d]", status));
 338                 ND_PRINT((ndo, " net:%s", ipaddr_string(ndo, &egp->egp_sourcenet)));
 339                 break;
 340
 341         case EGPT_UPDATE:
 342                 ND_PRINT((ndo, " update"));
 343                 if (status & EGPS_UNSOL) {
 344                         status &= ~EGPS_UNSOL;
 345                         ND_PRINT((ndo, " unsolicited"));
 346                 }
 347                 if (status <= EGPS_DOWN)
 348                         ND_PRINT((ndo, " state:%s", egp_status_updown[status]));
 349                 else
 350                         ND_PRINT((ndo, " [status %d]", status));
 351                 ND_PRINT((ndo, " %s int %d ext %d",
 352                        ipaddr_string(ndo, &egp->egp_sourcenet),
 353                        egp->egp_intgw,
 354                        egp->egp_extgw));
 355                 if (ndo->ndo_vflag)
 356                         egpnrprint(ndo, egp, length);
 357                 break;
 358
 359         case EGPT_ERROR:
 360                 ND_PRINT((ndo, " error"));
 361                 if (status <= EGPS_DOWN)
 362                         ND_PRINT((ndo, " state:%s", egp_status_updown[status]));
 363                 else
 364                         ND_PRINT((ndo, " [status %d]", status));
 365
 366                 if (EXTRACT_16BITS(&egp->egp_reason) <= EGPR_UVERSION)
 367                         ND_PRINT((ndo, " %s", egp_reasons[EXTRACT_16BITS(&egp->egp_reason)]));
 368                 else
 369                         ND_PRINT((ndo, " [reason %d]", EXTRACT_16BITS(&egp->egp_reason)));
 370                 break;
 371
 372         default:
 373                 ND_PRINT((ndo, "[type %d]", type));
 374                 break;
 375         }
 376 }