dist/tcpdump/print-stp.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (c) 2000 Lennert Buytenhek
   5  *
   6  * This software may be distributed either under the terms of the
   7  * BSD-style license that accompanies tcpdump or the GNU General
   8  * Public License
   9  *
  10  * Format and print IEEE 802.1d spanning tree protocol packets.
  11  * Contributed by Lennert Buytenhek <buytenh@gnu.org>
  12  */
  13
  14 #include <sys/cdefs.h>
  15 #ifndef lint
  16 #if 0
  17 static const char rcsid[] _U_ =
  18 "@(#) Header: /tcpdump/master/tcpdump/print-stp.c,v 1.13.2.7 2007/03/18 17:12:36 hannes Exp";
  19 #else
  20 __RCSID("$NetBSD: tcpdump2rcsid.ex,v 1.1 2001/06/25 20:09:58 itojun Exp $");
  21 #endif
  22 #endif
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include "config.h"
  26 #endif
  27
  28 #include <tcpdump-stdinc.h>
  29
  30 #include <stdlib.h>
  31 #include <stdio.h>
  32 #include <string.h>
  33
  34 #include "interface.h"
  35 #include "addrtoname.h"
  36 #include "extract.h"
  37
  38 #define RSTP_EXTRACT_PORT_ROLE(x) (((x)&0x0C)>>2)
  39 /* STP timers are expressed in multiples of 1/256th second */
  40 #define STP_TIME_BASE 256
  41 #define STP_BPDU_MSTP_MIN_LEN 102
  42
  43 struct stp_bpdu_ {
  44     u_int8_t protocol_id[2];
  45     u_int8_t protocol_version;
  46     u_int8_t bpdu_type;
  47     u_int8_t flags;
  48     u_int8_t root_id[8];
  49     u_int8_t root_path_cost[4];
  50     u_int8_t bridge_id[8];
  51     u_int8_t port_id[2];
  52     u_int8_t message_age[2];
  53     u_int8_t max_age[2];
  54     u_int8_t hello_time[2];
  55     u_int8_t forward_delay[2];
  56     u_int8_t v1_length;
  57 };
  58
  59 #define STP_PROTO_REGULAR 0x00
  60 #define STP_PROTO_RAPID   0x02
  61 #define STP_PROTO_MSTP    0x03
  62
  63 struct tok stp_proto_values[] = {
  64     { STP_PROTO_REGULAR, "802.1d" },
  65     { STP_PROTO_RAPID, "802.1w" },
  66     { STP_PROTO_MSTP, "802.1s" },
  67     { 0, NULL}
  68 };
  69
  70 #define STP_BPDU_TYPE_CONFIG      0x00
  71 #define STP_BPDU_TYPE_RSTP        0x02
  72 #define STP_BPDU_TYPE_TOPO_CHANGE 0x80
  73
  74 struct tok stp_bpdu_flag_values[] = {
  75     { 0x01, "Topology change" },
  76     { 0x02, "Proposal" },
  77     { 0x10, "Learn" },
  78     { 0x20, "Forward" },
  79     { 0x40, "Agreement" },
  80     { 0x80, "Topology change ACK" },
  81     { 0, NULL}
  82 };
  83
  84 struct tok stp_bpdu_type_values[] = {
  85     { STP_BPDU_TYPE_CONFIG, "Config" },
  86     { STP_BPDU_TYPE_RSTP, "Rapid STP" },
  87     { STP_BPDU_TYPE_TOPO_CHANGE, "Topology Change" },
  88     { 0, NULL}
  89 };
  90
  91 struct tok rstp_obj_port_role_values[] = {
  92     { 0x00, "Unknown" },
  93     { 0x01, "Alternate" },
  94     { 0x02, "Root" },
  95     { 0x03, "Designated" },
  96     { 0, NULL}
  97 };
  98
  99 static char *
 100 stp_print_bridge_id(const u_char *p)
 101 {
 102     static char bridge_id_str[sizeof("pppp.aa:bb:cc:dd:ee:ff")];
 103
 104     snprintf(bridge_id_str, sizeof(bridge_id_str),
 105              "%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
 106              p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
 107
 108     return bridge_id_str;
 109 }
 110
 111 static void
 112 stp_print_config_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length)
 113 {
 114     printf(", Flags [%s]",
 115            bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags));
 116
 117     printf(", bridge-id %s.%04x, length %u",
 118            stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id),
 119            EXTRACT_16BITS(&stp_bpdu->port_id), length);
 120
 121     /* in non-verbose mode just print the bridge-id */
 122     if (!vflag) {
 123         return;
 124     }
 125
 126     printf("\n\tmessage-age %.2fs, max-age %.2fs"
 127            ", hello-time %.2fs, forwarding-delay %.2fs",
 128            (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE,
 129            (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE,
 130            (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE,
 131            (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE);
 132
 133     printf("\n\troot-id %s, root-pathcost %u",
 134            stp_print_bridge_id((const u_char *)&stp_bpdu->root_id),
 135            EXTRACT_32BITS(&stp_bpdu->root_path_cost));
 136
 137     /* Port role is only valid for 802.1w */
 138     if (stp_bpdu->protocol_version == STP_PROTO_RAPID) {
 139         printf(", port-role %s",
 140                tok2str(rstp_obj_port_role_values, "Unknown",
 141                        RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags)));
 142     }
 143 }
 144
 145 /*
 146  * MSTP packet format
 147  * Ref. IEEE 802.1Q 2003 Ed. Section 14
 148  *
 149  * MSTP BPDU
 150  *
 151  * 2 -  bytes Protocol Id
 152  * 1 -  byte  Protocol Ver.
 153  * 1 -  byte  BPDU tye
 154  * 1 -  byte  Flags
 155  * 8 -  bytes CIST Root Identifier
 156  * 4 -  bytes CIST External Path Cost
 157  * 8 -  bytes CIST Regional Root Identifier
 158  * 2 -  bytes CIST Port Identifier
 159  * 2 -  bytes Message Age
 160  * 2 -  bytes Max age
 161  * 2 -  bytes Hello Time
 162  * 2 -  bytes Forward delay
 163  * 1 -  byte  Version 1 length. Must be 0
 164  * 2 -  bytes Version 3 length
 165  * 1 -  byte  Config Identifier
 166  * 32 - bytes Config Name
 167  * 2 -  bytes Revision level
 168  * 16 - bytes Config Digest [MD5]
 169  * 4 -  bytes CIST Internal Root Path Cost
 170  * 8 -  bytes CIST Bridge Identifier
 171  * 1 -  byte  CIST Remaining Hops
 172  * 16 - bytes MSTI information [Max 64 MSTI, each 16 bytes]
 173  *
 174  * MSTI Payload
 175  *
 176  * 1 - byte  MSTI flag
 177  * 8 - bytes MSTI Regional Root Identifier
 178  * 4 - bytes MSTI Regional Path Cost
 179  * 1 - byte  MSTI Bridge Priority
 180  * 1 - byte  MSTI Port Priority
 181  * 1 - byte  MSTI Remaining Hops
 182  */
 183
 184 #define MST_BPDU_MSTI_LENGTH                16
 185 #define MST_BPDU_CONFIG_INFO_LENGTH         64
 186
 187 /* Offsets of fields from the begginning for the packet */
 188 #define MST_BPDU_VER3_LEN_OFFSET            36
 189 #define MST_BPDU_CONFIG_NAME_OFFSET         39
 190 #define MST_BPDU_CONFIG_DIGEST_OFFSET       73
 191 #define MST_BPDU_CIST_INT_PATH_COST_OFFSET  89
 192 #define MST_BPDU_CIST_BRIDGE_ID_OFFSET      93
 193 #define MST_BPDU_CIST_REMAIN_HOPS_OFFSET    101
 194 #define MST_BPDU_MSTI_OFFSET                102
 195 /* Offsets within  an MSTI */
 196 #define MST_BPDU_MSTI_ROOT_PRIO_OFFSET      1
 197 #define MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET 9
 198 #define MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET    13
 199 #define MST_BPDU_MSTI_PORT_PRIO_OFFSET      14
 200 #define MST_BPDU_MSTI_REMAIN_HOPS_OFFSET    15
 201
 202 static void
 203 stp_print_mstp_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length)
 204 {
 205     const u_char    *ptr;
 206     u_int16_t       v3len;
 207     u_int16_t       len;
 208     u_int16_t       msti;
 209     u_int16_t       offset;
 210
 211     ptr = (const u_char *)stp_bpdu;
 212     printf(", CIST Flags [%s]",
 213            bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags));
 214
 215     /*
 216      * in non-verbose mode just print the flags. We dont read that much
 217      * of the packet (DEFAULT_SNAPLEN) to print out cist bridge-id
 218      */
 219     if (!vflag) {
 220         return;
 221     }
 222
 223     printf(", CIST bridge-id %s.%04x, length %u",
 224            stp_print_bridge_id(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET),
 225            EXTRACT_16BITS(&stp_bpdu->port_id), length);
 226
 227
 228     printf("\n\tmessage-age %.2fs, max-age %.2fs"
 229            ", hello-time %.2fs, forwarding-delay %.2fs",
 230            (float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE,
 231            (float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE,
 232            (float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE,
 233            (float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE);
 234
 235     printf("\n\tCIST root-id %s, ext-pathcost %u int-pathcost %u",
 236            stp_print_bridge_id((const u_char *)&stp_bpdu->root_id),
 237            EXTRACT_32BITS(&stp_bpdu->root_path_cost),
 238            EXTRACT_32BITS(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET));
 239
 240     printf(", port-role %s",
 241            tok2str(rstp_obj_port_role_values, "Unknown",
 242                    RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags)));
 243
 244     printf("\n\tCIST regional-root-id %s",
 245            stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id));
 246
 247     printf("\n\tMSTP Configuration Name %s, revision %u, digest %08x%08x%08x%08x",
 248            ptr + MST_BPDU_CONFIG_NAME_OFFSET,
 249            EXTRACT_16BITS(ptr + MST_BPDU_CONFIG_NAME_OFFSET + 32),
 250            EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET),
 251            EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 4),
 252            EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 8),
 253            EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12));
 254
 255     printf("\n\tCIST remaining-hops %d", ptr[MST_BPDU_CIST_REMAIN_HOPS_OFFSET]);
 256
 257     /* Dump all MSTI's */
 258     v3len = EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET);
 259     if (v3len > MST_BPDU_CONFIG_INFO_LENGTH) {
 260         len = v3len - MST_BPDU_CONFIG_INFO_LENGTH;
 261         offset = MST_BPDU_MSTI_OFFSET;
 262         while (len >= MST_BPDU_MSTI_LENGTH) {
 263             msti = EXTRACT_16BITS(ptr + offset +
 264                                   MST_BPDU_MSTI_ROOT_PRIO_OFFSET);
 265             msti = msti & 0x0FFF;
 266
 267             printf("\n\tMSTI %d, Flags [%s], port-role %s",
 268                    msti, bittok2str(stp_bpdu_flag_values, "none", ptr[offset]),
 269                    tok2str(rstp_obj_port_role_values, "Unknown",
 270                            RSTP_EXTRACT_PORT_ROLE(ptr[offset])));
 271             printf("\n\t\tMSTI regional-root-id %s, pathcost %u",
 272                    stp_print_bridge_id(ptr + offset +
 273                                        MST_BPDU_MSTI_ROOT_PRIO_OFFSET),
 274                    EXTRACT_32BITS(ptr + offset +
 275                                   MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET));
 276             printf("\n\t\tMSTI bridge-prio %d, port-prio %d, hops %d",
 277                    ptr[offset + MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET] >> 4,
 278                    ptr[offset + MST_BPDU_MSTI_PORT_PRIO_OFFSET] >> 4,
 279                    ptr[offset + MST_BPDU_MSTI_REMAIN_HOPS_OFFSET]);
 280
 281             len -= MST_BPDU_MSTI_LENGTH;
 282             offset += MST_BPDU_MSTI_LENGTH;
 283         }
 284     }
 285 }
 286
 287 /*
 288  * Print 802.1d / 802.1w / 802.1q (mstp) packets.
 289  */
 290 void
 291 stp_print(const u_char *p, u_int length)
 292 {
 293     const struct stp_bpdu_ *stp_bpdu;
 294     u_int16_t              mstp_len;
 295
 296     stp_bpdu = (struct stp_bpdu_*)p;
 297
 298     /* Minimum STP Frame size. */
 299     if (length < 4)
 300         goto trunc;
 301
 302     if (EXTRACT_16BITS(&stp_bpdu->protocol_id)) {
 303         printf("unknown STP version, length %u", length);
 304         return;
 305     }
 306
 307     printf("STP %s", tok2str(stp_proto_values, "Unknown STP protocol (0x%02x)",
 308                          stp_bpdu->protocol_version));
 309
 310     switch (stp_bpdu->protocol_version) {
 311     case STP_PROTO_REGULAR:
 312     case STP_PROTO_RAPID:
 313     case STP_PROTO_MSTP:
 314         break;
 315     default:
 316         return;
 317     }
 318
 319     printf(", %s", tok2str(stp_bpdu_type_values, "Unknown BPDU Type (0x%02x)",
 320                            stp_bpdu->bpdu_type));
 321
 322     switch (stp_bpdu->bpdu_type) {
 323     case STP_BPDU_TYPE_CONFIG:
 324         if (length < sizeof(struct stp_bpdu_) - 1) {
 325             goto trunc;
 326         }
 327         stp_print_config_bpdu(stp_bpdu, length);
 328         break;
 329
 330     case STP_BPDU_TYPE_RSTP:
 331         if (stp_bpdu->protocol_version == STP_PROTO_RAPID) {
 332             if (length < sizeof(struct stp_bpdu_)) {
 333                 goto trunc;
 334             }
 335             stp_print_config_bpdu(stp_bpdu, length);
 336         } else if (stp_bpdu->protocol_version == STP_PROTO_MSTP) {
 337             if (length < STP_BPDU_MSTP_MIN_LEN) {
 338                 goto trunc;
 339             }
 340             if (stp_bpdu->v1_length != 0) {
 341                 /* FIX ME: Emit a message here ? */
 342                 goto trunc;
 343             }
 344             /* Validate v3 length */
 345             mstp_len = EXTRACT_16BITS(p + MST_BPDU_VER3_LEN_OFFSET);
 346             mstp_len += 2;  /* length encoding itself is 2 bytes */
 347             if (length < (sizeof(struct stp_bpdu_) + mstp_len)) {
 348                 goto trunc;
 349             }
 350             stp_print_mstp_bpdu(stp_bpdu, length);
 351         }
 352         break;
 353
 354     case STP_BPDU_TYPE_TOPO_CHANGE:
 355         /* always empty message - just break out */
 356         break;
 357
 358     default:
 359         break;
 360     }
 361
 362     return;
 363  trunc:
 364     printf("[|stp %d]", length);
 365 }
 366
 367 /*
 368  * Local Variables:
 369  * c-style: whitesmith
 370  * c-basic-offset: 4
 371  * End:
 372  */