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

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 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, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  *
  21  * Hacked version of print-ether.c  Larry Lile <lile@stdio.com>
  22  *
  23  * Further tweaked to more closely resemble print-fddi.c
  24  *      Guy Harris <guy@alum.mit.edu>
  25  */
  26
  27 /* \summary: Token Ring printer */
  28
  29 #ifdef HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif
  32
  33 #include <netdissect-stdinc.h>
  34
  35 #include <string.h>
  36
  37 #include "netdissect.h"
  38 #include "extract.h"
  39 #include "addrtoname.h"
  40 #include "ether.h"
  41
  42 /*
  43  * Copyright (c) 1998, Larry Lile
  44  * All rights reserved.
  45  *
  46  * Redistribution and use in source and binary forms, with or without
  47  * modification, are permitted provided that the following conditions
  48  * are met:
  49  * 1. Redistributions of source code must retain the above copyright
  50  *    notice unmodified, this list of conditions, and the following
  51  *    disclaimer.
  52  * 2. Redistributions in binary form must reproduce the above copyright
  53  *    notice, this list of conditions and the following disclaimer in the
  54  *    documentation and/or other materials provided with the distribution.
  55  *
  56  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  57  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  58  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  59  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  60  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  61  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  62  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  63  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  64  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  65  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  66  * SUCH DAMAGE.
  67  *
  68  */
  69
  70 #define TOKEN_HDRLEN            14
  71 #define TOKEN_RING_MAC_LEN      6
  72 #define ROUTING_SEGMENT_MAX     16
  73 #define IS_SOURCE_ROUTED(trp)   ((trp)->token_shost[0] & 0x80)
  74 #define FRAME_TYPE(trp)         (((trp)->token_fc & 0xC0) >> 6)
  75 #define TOKEN_FC_LLC            1
  76
  77 #define BROADCAST(trp)          ((EXTRACT_16BITS(&(trp)->token_rcf) & 0xE000) >> 13)
  78 #define RIF_LENGTH(trp)         ((EXTRACT_16BITS(&(trp)->token_rcf) & 0x1f00) >> 8)
  79 #define DIRECTION(trp)          ((EXTRACT_16BITS(&(trp)->token_rcf) & 0x0080) >> 7)
  80 #define LARGEST_FRAME(trp)      ((EXTRACT_16BITS(&(trp)->token_rcf) & 0x0070) >> 4)
  81 #define RING_NUMBER(trp, x)     ((EXTRACT_16BITS(&(trp)->token_rseg[x]) & 0xfff0) >> 4)
  82 #define BRIDGE_NUMBER(trp, x)   ((EXTRACT_16BITS(&(trp)->token_rseg[x]) & 0x000f))
  83 #define SEGMENT_COUNT(trp)      ((int)((RIF_LENGTH(trp) - 2) / 2))
  84
  85 struct token_header {
  86         uint8_t  token_ac;
  87         uint8_t  token_fc;
  88         uint8_t  token_dhost[TOKEN_RING_MAC_LEN];
  89         uint8_t  token_shost[TOKEN_RING_MAC_LEN];
  90         uint16_t token_rcf;
  91         uint16_t token_rseg[ROUTING_SEGMENT_MAX];
  92 };
  93
  94 static const char tstr[] = "[|token-ring]";
  95
  96 /* Extract src, dst addresses */
  97 static inline void
  98 extract_token_addrs(const struct token_header *trp, char *fsrc, char *fdst)
  99 {
 100         memcpy(fdst, (const char *)trp->token_dhost, 6);
 101         memcpy(fsrc, (const char *)trp->token_shost, 6);
 102 }
 103
 104 /*
 105  * Print the TR MAC header
 106  */
 107 static inline void
 108 token_hdr_print(netdissect_options *ndo,
 109                 register const struct token_header *trp, register u_int length,
 110                 register const u_char *fsrc, register const u_char *fdst)
 111 {
 112         const char *srcname, *dstname;
 113
 114         srcname = etheraddr_string(ndo, fsrc);
 115         dstname = etheraddr_string(ndo, fdst);
 116
 117         if (!ndo->ndo_qflag)
 118                 ND_PRINT((ndo, "%02x %02x ",
 119                        trp->token_ac,
 120                        trp->token_fc));
 121         ND_PRINT((ndo, "%s > %s, length %u: ",
 122                srcname, dstname,
 123                length));
 124 }
 125
 126 static const char *broadcast_indicator[] = {
 127         "Non-Broadcast", "Non-Broadcast",
 128         "Non-Broadcast", "Non-Broadcast",
 129         "All-routes",    "All-routes",
 130         "Single-route",  "Single-route"
 131 };
 132
 133 static const char *direction[] = {
 134         "Forward", "Backward"
 135 };
 136
 137 static const char *largest_frame[] = {
 138         "516",
 139         "1500",
 140         "2052",
 141         "4472",
 142         "8144",
 143         "11407",
 144         "17800",
 145         "??"
 146 };
 147
 148 u_int
 149 token_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen)
 150 {
 151         const struct token_header *trp;
 152         int llc_hdrlen;
 153         struct ether_header ehdr;
 154         u_int route_len = 0, hdr_len = TOKEN_HDRLEN;
 155         int seg;
 156
 157         trp = (const struct token_header *)p;
 158
 159         if (caplen < TOKEN_HDRLEN) {
 160                 ND_PRINT((ndo, "%s", tstr));
 161                 return hdr_len;
 162         }
 163
 164         /*
 165          * Get the TR addresses into a canonical form
 166          */
 167         extract_token_addrs(trp, (char*)ESRC(&ehdr), (char*)EDST(&ehdr));
 168
 169         /* Adjust for source routing information in the MAC header */
 170         if (IS_SOURCE_ROUTED(trp)) {
 171                 /* Clear source-routed bit */
 172                 *ESRC(&ehdr) &= 0x7f;
 173
 174                 if (ndo->ndo_eflag)
 175                         token_hdr_print(ndo, trp, length, ESRC(&ehdr), EDST(&ehdr));
 176
 177                 if (caplen < TOKEN_HDRLEN + 2) {
 178                         ND_PRINT((ndo, "%s", tstr));
 179                         return hdr_len;
 180                 }
 181                 route_len = RIF_LENGTH(trp);
 182                 hdr_len += route_len;
 183                 if (caplen < hdr_len) {
 184                         ND_PRINT((ndo, "%s", tstr));
 185                         return hdr_len;
 186                 }
 187                 if (ndo->ndo_vflag) {
 188                         ND_PRINT((ndo, "%s ", broadcast_indicator[BROADCAST(trp)]));
 189                         ND_PRINT((ndo, "%s", direction[DIRECTION(trp)]));
 190
 191                         for (seg = 0; seg < SEGMENT_COUNT(trp); seg++)
 192                                 ND_PRINT((ndo, " [%d:%d]", RING_NUMBER(trp, seg),
 193                                     BRIDGE_NUMBER(trp, seg)));
 194                 } else {
 195                         ND_PRINT((ndo, "rt = %x", EXTRACT_16BITS(&trp->token_rcf)));
 196
 197                         for (seg = 0; seg < SEGMENT_COUNT(trp); seg++)
 198                                 ND_PRINT((ndo, ":%x", EXTRACT_16BITS(&trp->token_rseg[seg])));
 199                 }
 200                 ND_PRINT((ndo, " (%s) ", largest_frame[LARGEST_FRAME(trp)]));
 201         } else {
 202                 if (ndo->ndo_eflag)
 203                         token_hdr_print(ndo, trp, length, ESRC(&ehdr), EDST(&ehdr));
 204         }
 205
 206         /* Skip over token ring MAC header and routing information */
 207         length -= hdr_len;
 208         p += hdr_len;
 209         caplen -= hdr_len;
 210
 211         /* Frame Control field determines interpretation of packet */
 212         if (FRAME_TYPE(trp) == TOKEN_FC_LLC) {
 213                 /* Try to print the LLC-layer header & higher layers */
 214                 llc_hdrlen = llc_print(ndo, p, length, caplen, ESRC(&ehdr),
 215                     EDST(&ehdr));
 216                 if (llc_hdrlen < 0) {
 217                         /* packet type not known, print raw packet */
 218                         if (!ndo->ndo_suppress_default_print)
 219                                 ND_DEFAULTPRINT(p, caplen);
 220                         llc_hdrlen = -llc_hdrlen;
 221                 }
 222                 hdr_len += llc_hdrlen;
 223         } else {
 224                 /* Some kinds of TR packet we cannot handle intelligently */
 225                 /* XXX - dissect MAC packets if frame type is 0 */
 226                 if (!ndo->ndo_eflag)
 227                         token_hdr_print(ndo, trp, length + TOKEN_HDRLEN + route_len,
 228                             ESRC(&ehdr), EDST(&ehdr));
 229                 if (!ndo->ndo_suppress_default_print)
 230                         ND_DEFAULTPRINT(p, caplen);
 231         }
 232         return (hdr_len);
 233 }
 234
 235 /*
 236  * This is the top level routine of the printer.  'p' points
 237  * to the TR header of the packet, 'h->ts' is the timestamp,
 238  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
 239  * is the number of bytes actually captured.
 240  */
 241 u_int
 242 token_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
 243 {
 244         return (token_print(ndo, p, h->len, h->caplen));
 245 }