contrib/tcpdump/print-chdlc.c

   1 /*
   2  * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997
   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
  22 #define NETDISSECT_REWORKED
  23 #ifdef HAVE_CONFIG_H
  24 #include "config.h"
  25 #endif
  26
  27 #include <tcpdump-stdinc.h>
  28
  29 #include "interface.h"
  30 #include "addrtoname.h"
  31 #include "ethertype.h"
  32 #include "extract.h"
  33 #include "chdlc.h"
  34
  35 static void chdlc_slarp_print(netdissect_options *, const u_char *, u_int);
  36
  37 static const struct tok chdlc_cast_values[] = {
  38     { CHDLC_UNICAST, "unicast" },
  39     { CHDLC_BCAST, "bcast" },
  40     { 0, NULL}
  41 };
  42
  43
  44 /* Standard CHDLC printer */
  45 u_int
  46 chdlc_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, register const u_char *p)
  47 {
  48         register u_int length = h->len;
  49         register u_int caplen = h->caplen;
  50
  51         if (caplen < CHDLC_HDRLEN) {
  52                 ND_PRINT((ndo, "[|chdlc]"));
  53                 return (caplen);
  54         }
  55         return (chdlc_print(ndo, p,length));
  56 }
  57
  58 u_int
  59 chdlc_print(netdissect_options *ndo, register const u_char *p, u_int length)
  60 {
  61         u_int proto;
  62
  63         proto = EXTRACT_16BITS(&p[2]);
  64         if (ndo->ndo_eflag) {
  65                 ND_PRINT((ndo, "%s, ethertype %s (0x%04x), length %u: ",
  66                        tok2str(chdlc_cast_values, "0x%02x", p[0]),
  67                        tok2str(ethertype_values, "Unknown", proto),
  68                        proto,
  69                        length));
  70         }
  71
  72         length -= CHDLC_HDRLEN;
  73         p += CHDLC_HDRLEN;
  74
  75         switch (proto) {
  76         case ETHERTYPE_IP:
  77                 ip_print(ndo, p, length);
  78                 break;
  79         case ETHERTYPE_IPV6:
  80                 ip6_print(ndo, p, length);
  81                 break;
  82         case CHDLC_TYPE_SLARP:
  83                 chdlc_slarp_print(ndo, p, length);
  84                 break;
  85 #if 0
  86         case CHDLC_TYPE_CDP:
  87                 chdlc_cdp_print(p, length);
  88                 break;
  89 #endif
  90         case ETHERTYPE_MPLS:
  91         case ETHERTYPE_MPLS_MULTI:
  92                 mpls_print(ndo, p, length);
  93                 break;
  94         case ETHERTYPE_ISO:
  95                 /* is the fudge byte set ? lets verify by spotting ISO headers */
  96                 if (*(p+1) == 0x81 ||
  97                     *(p+1) == 0x82 ||
  98                     *(p+1) == 0x83)
  99                     isoclns_print(ndo, p + 1, length - 1, length - 1);
 100                 else
 101                     isoclns_print(ndo, p, length, length);
 102                 break;
 103         default:
 104                 if (!ndo->ndo_eflag)
 105                         ND_PRINT((ndo, "unknown CHDLC protocol (0x%04x)", proto));
 106                 break;
 107         }
 108
 109         return (CHDLC_HDRLEN);
 110 }
 111
 112 /*
 113  * The fixed-length portion of a SLARP packet.
 114  */
 115 struct cisco_slarp {
 116         uint8_t code[4];
 117 #define SLARP_REQUEST   0
 118 #define SLARP_REPLY     1
 119 #define SLARP_KEEPALIVE 2
 120         union {
 121                 struct {
 122                         uint8_t addr[4];
 123                         uint8_t mask[4];
 124                 } addr;
 125                 struct {
 126                         uint8_t myseq[4];
 127                         uint8_t yourseq[4];
 128                         uint8_t rel[2];
 129                 } keep;
 130         } un;
 131 };
 132
 133 #define SLARP_MIN_LEN   14
 134 #define SLARP_MAX_LEN   18
 135
 136 static void
 137 chdlc_slarp_print(netdissect_options *ndo, const u_char *cp, u_int length)
 138 {
 139         const struct cisco_slarp *slarp;
 140         u_int sec,min,hrs,days;
 141
 142         ND_PRINT((ndo, "SLARP (length: %u), ",length));
 143         if (length < SLARP_MIN_LEN)
 144                 goto trunc;
 145
 146         slarp = (const struct cisco_slarp *)cp;
 147         ND_TCHECK2(*slarp, SLARP_MIN_LEN);
 148         switch (EXTRACT_32BITS(&slarp->code)) {
 149         case SLARP_REQUEST:
 150                 ND_PRINT((ndo, "request"));
 151                 /*
 152                  * At least according to William "Chops" Westfield's
 153                  * message in
 154                  *
 155                  *      http://www.nethelp.no/net/cisco-hdlc.txt
 156                  *
 157                  * the address and mask aren't used in requests -
 158                  * they're just zero.
 159                  */
 160                 break;
 161         case SLARP_REPLY:
 162                 ND_PRINT((ndo, "reply %s/%s",
 163                         ipaddr_string(ndo, &slarp->un.addr.addr),
 164                         ipaddr_string(ndo, &slarp->un.addr.mask)));
 165                 break;
 166         case SLARP_KEEPALIVE:
 167                 ND_PRINT((ndo, "keepalive: mineseen=0x%08x, yourseen=0x%08x, reliability=0x%04x",
 168                        EXTRACT_32BITS(&slarp->un.keep.myseq),
 169                        EXTRACT_32BITS(&slarp->un.keep.yourseq),
 170                        EXTRACT_16BITS(&slarp->un.keep.rel)));
 171
 172                 if (length >= SLARP_MAX_LEN) { /* uptime-stamp is optional */
 173                         cp += SLARP_MIN_LEN;
 174                         ND_TCHECK2(*cp, 4);
 175                         sec = EXTRACT_32BITS(cp) / 1000;
 176                         min = sec / 60; sec -= min * 60;
 177                         hrs = min / 60; min -= hrs * 60;
 178                         days = hrs / 24; hrs -= days * 24;
 179                         ND_PRINT((ndo, ", link uptime=%ud%uh%um%us",days,hrs,min,sec));
 180                 }
 181                 break;
 182         default:
 183                 ND_PRINT((ndo, "0x%02x unknown", EXTRACT_32BITS(&slarp->code)));
 184                 if (ndo->ndo_vflag <= 1)
 185                     print_unknown_data(ndo,cp+4,"\n\t",length-4);
 186                 break;
 187         }
 188
 189         if (SLARP_MAX_LEN < length && ndo->ndo_vflag)
 190                 ND_PRINT((ndo, ", (trailing junk: %d bytes)", length - SLARP_MAX_LEN));
 191         if (ndo->ndo_vflag > 1)
 192             print_unknown_data(ndo,cp+4,"\n\t",length-4);
 193         return;
 194
 195 trunc:
 196         ND_PRINT((ndo, "[|slarp]"));
 197 }
 198
 199
 200 /*
 201  * Local Variables:
 202  * c-style: whitesmith
 203  * c-basic-offset: 8
 204  * End:
 205  */