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 #ifndef lint
  23 static const char rcsid[] _U_ =
  24     "@(#) $Header: /tcpdump/master/tcpdump/print-chdlc.c,v 1.43 2005-11-29 08:56:19 hannes Exp $ (LBL)";
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <tcpdump-stdinc.h>
  32
  33 #include <pcap.h>
  34 #include <stdio.h>
  35
  36 #include "interface.h"
  37 #include "addrtoname.h"
  38 #include "ethertype.h"
  39 #include "extract.h"
  40 #include "ppp.h"
  41 #include "chdlc.h"
  42
  43 static void chdlc_slarp_print(const u_char *, u_int);
  44
  45 const struct tok chdlc_cast_values[] = {
  46     { CHDLC_UNICAST, "unicast" },
  47     { CHDLC_BCAST, "bcast" },
  48     { 0, NULL}
  49 };
  50
  51
  52 /* Standard CHDLC printer */
  53 u_int
  54 chdlc_if_print(const struct pcap_pkthdr *h, register const u_char *p)
  55 {
  56         register u_int length = h->len;
  57         register u_int caplen = h->caplen;
  58
  59         if (caplen < CHDLC_HDRLEN) {
  60                 printf("[|chdlc]");
  61                 return (caplen);
  62         }
  63         return (chdlc_print(p,length));
  64 }
  65
  66 u_int
  67 chdlc_print(register const u_char *p, u_int length) {
  68         u_int proto;
  69
  70         proto = EXTRACT_16BITS(&p[2]);
  71         if (eflag) {
  72                 printf("%s, ethertype %s (0x%04x), length %u: ",
  73                        tok2str(chdlc_cast_values, "0x%02x", p[0]),
  74                        tok2str(ethertype_values, "Unknown", proto),
  75                        proto,
  76                        length);
  77         }
  78
  79         length -= CHDLC_HDRLEN;
  80         p += CHDLC_HDRLEN;
  81
  82         switch (proto) {
  83         case ETHERTYPE_IP:
  84                 ip_print(gndo, p, length);
  85                 break;
  86 #ifdef INET6
  87         case ETHERTYPE_IPV6:
  88                 ip6_print(gndo, p, length);
  89                 break;
  90 #endif
  91         case CHDLC_TYPE_SLARP:
  92                 chdlc_slarp_print(p, length);
  93                 break;
  94 #if 0
  95         case CHDLC_TYPE_CDP:
  96                 chdlc_cdp_print(p, length);
  97                 break;
  98 #endif
  99         case ETHERTYPE_MPLS:
 100         case ETHERTYPE_MPLS_MULTI:
 101                 mpls_print(p, length);
 102                 break;
 103         case ETHERTYPE_ISO:
 104                 /* is the fudge byte set ? lets verify by spotting ISO headers */
 105                 if (*(p+1) == 0x81 ||
 106                     *(p+1) == 0x82 ||
 107                     *(p+1) == 0x83)
 108                     isoclns_print(p+1, length-1, length-1);
 109                 else
 110                     isoclns_print(p, length, length);
 111                 break;
 112         default:
 113                 if (!eflag)
 114                         printf("unknown CHDLC protocol (0x%04x)", proto);
 115                 break;
 116         }
 117
 118         return (CHDLC_HDRLEN);
 119 }
 120
 121 /*
 122  * The fixed-length portion of a SLARP packet.
 123  */
 124 struct cisco_slarp {
 125         u_int8_t code[4];
 126 #define SLARP_REQUEST   0
 127 #define SLARP_REPLY     1
 128 #define SLARP_KEEPALIVE 2
 129         union {
 130                 struct {
 131                         u_int8_t addr[4];
 132                         u_int8_t mask[4];
 133                 } addr;
 134                 struct {
 135                         u_int8_t myseq[4];
 136                         u_int8_t yourseq[4];
 137                         u_int8_t rel[2];
 138                 } keep;
 139         } un;
 140 };
 141
 142 #define SLARP_MIN_LEN   14
 143 #define SLARP_MAX_LEN   18
 144
 145 static void
 146 chdlc_slarp_print(const u_char *cp, u_int length)
 147 {
 148         const struct cisco_slarp *slarp;
 149         u_int sec,min,hrs,days;
 150
 151         printf("SLARP (length: %u), ",length);
 152         if (length < SLARP_MIN_LEN)
 153                 goto trunc;
 154
 155         slarp = (const struct cisco_slarp *)cp;
 156         TCHECK2(*slarp, SLARP_MIN_LEN);
 157         switch (EXTRACT_32BITS(&slarp->code)) {
 158         case SLARP_REQUEST:
 159                 printf("request");
 160                 /*
 161                  * At least according to William "Chops" Westfield's
 162                  * message in
 163                  *
 164                  *      http://www.nethelp.no/net/cisco-hdlc.txt
 165                  *
 166                  * the address and mask aren't used in requests -
 167                  * they're just zero.
 168                  */
 169                 break;
 170         case SLARP_REPLY:
 171                 printf("reply %s/%s",
 172                         ipaddr_string(&slarp->un.addr.addr),
 173                         ipaddr_string(&slarp->un.addr.mask));
 174                 break;
 175         case SLARP_KEEPALIVE:
 176                 printf("keepalive: mineseen=0x%08x, yourseen=0x%08x, reliability=0x%04x",
 177                        EXTRACT_32BITS(&slarp->un.keep.myseq),
 178                        EXTRACT_32BITS(&slarp->un.keep.yourseq),
 179                        EXTRACT_16BITS(&slarp->un.keep.rel));
 180
 181                 if (length >= SLARP_MAX_LEN) { /* uptime-stamp is optional */
 182                         cp += SLARP_MIN_LEN;
 183                         if (!TTEST2(*cp, 4))
 184                                 goto trunc;
 185                         sec = EXTRACT_32BITS(cp) / 1000;
 186                         min = sec / 60; sec -= min * 60;
 187                         hrs = min / 60; min -= hrs * 60;
 188                         days = hrs / 24; hrs -= days * 24;
 189                         printf(", link uptime=%ud%uh%um%us",days,hrs,min,sec);
 190                 }
 191                 break;
 192         default:
 193                 printf("0x%02x unknown", EXTRACT_32BITS(&slarp->code));
 194                 if (vflag <= 1)
 195                     print_unknown_data(cp+4,"\n\t",length-4);
 196                 break;
 197         }
 198
 199         if (SLARP_MAX_LEN < length && vflag)
 200                 printf(", (trailing junk: %d bytes)", length - SLARP_MAX_LEN);
 201         if (vflag > 1)
 202             print_unknown_data(cp+4,"\n\t",length-4);
 203         return;
 204
 205 trunc:
 206         printf("[|slarp]");
 207 }
 208
 209
 210 /*
 211  * Local Variables:
 212  * c-style: whitesmith
 213  * c-basic-offset: 8
 214  * End:
 215  */