The Tcpdump Group git mirrors - tcpdump/blob - 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 1.32.2.8 2005-08-23 10:29:42 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 /* Standard CHDLC printer */
  46 u_int
  47 chdlc_if_print(const struct pcap_pkthdr *h, register const u_char *p)
  48 {
  49         register u_int length = h->len;
  50         register u_int caplen = h->caplen;
  51
  52         if (caplen < CHDLC_HDRLEN) {
  53                 printf("[|chdlc]");
  54                 return (caplen);
  55         }
  56         return (chdlc_print(p,length));
  57 }
  58
  59 u_int
  60 chdlc_print(register const u_char *p, u_int length) {
  61         u_int proto;
  62         const struct ip *ip;
  63
  64         proto = EXTRACT_16BITS(&p[2]);
  65         if (eflag) {
  66                 switch (p[0]) {
  67                 case CHDLC_UNICAST:
  68                         printf("unicast ");
  69                         break;
  70                 case CHDLC_BCAST:
  71                         printf("bcast ");
  72                         break;
  73                 default:
  74                         printf("0x%02x ", p[0]);
  75                         break;
  76                 }
  77                 printf("%d %04x: ", length, proto);
  78         }
  79
  80         length -= CHDLC_HDRLEN;
  81         ip = (const struct ip *)(p + CHDLC_HDRLEN);
  82         switch (proto) {
  83         case ETHERTYPE_IP:
  84                 ip_print(gndo, (const u_char *)ip, length);
  85                 break;
  86 #ifdef INET6
  87         case ETHERTYPE_IPV6:
  88                 ip6_print((const u_char *)ip, length);
  89                 break;
  90 #endif
  91         case CHDLC_TYPE_SLARP:
  92                 chdlc_slarp_print((const u_char *)ip, length);
  93                 break;
  94 #if 0
  95         case CHDLC_TYPE_CDP:
  96                 chdlc_cdp_print((const u_char *)ip, length);
  97                 break;
  98 #endif
  99         case ETHERTYPE_MPLS:
 100         case ETHERTYPE_MPLS_MULTI:
 101                 mpls_print((const u_char *)(ip), length);
 102                 break;
 103         case ETHERTYPE_ISO:
 104                 /* is the fudge byte set ? lets verify by spotting ISO headers */
 105                 if (*(p+CHDLC_HDRLEN+1) == 0x81 ||
 106                     *(p+CHDLC_HDRLEN+1) == 0x82 ||
 107                     *(p+CHDLC_HDRLEN+1) == 0x83)
 108                     isoclns_print(p+CHDLC_HDRLEN+1, length-1, length-1);
 109                 else
 110                     isoclns_print(p+CHDLC_HDRLEN, length, length);
 111                 break;
 112         default:
 113                 printf("unknown CHDLC protocol (0x%04x)", proto);
 114                 break;
 115         }
 116
 117         return (CHDLC_HDRLEN);
 118 }
 119
 120 /*
 121  * The fixed-length portion of a SLARP packet.
 122  */
 123 struct cisco_slarp {
 124         u_int8_t code[4];
 125 #define SLARP_REQUEST   0
 126 #define SLARP_REPLY     1
 127 #define SLARP_KEEPALIVE 2
 128         union {
 129                 struct {
 130                         u_int8_t addr[4];
 131                         u_int8_t mask[4];
 132                 } addr;
 133                 struct {
 134                         u_int8_t myseq[4];
 135                         u_int8_t yourseq[4];
 136                         u_int8_t rel[2];
 137                 } keep;
 138         } un;
 139 };
 140
 141 #define SLARP_MIN_LEN   14
 142 #define SLARP_MAX_LEN   18
 143
 144 static void
 145 chdlc_slarp_print(const u_char *cp, u_int length)
 146 {
 147         const struct cisco_slarp *slarp;
 148         u_int sec,min,hrs,days;
 149
 150         printf("SLARP (length: %u), ",length);
 151         if (length < SLARP_MIN_LEN)
 152                 goto trunc;
 153
 154         slarp = (const struct cisco_slarp *)cp;
 155         TCHECK2(*slarp, SLARP_MIN_LEN);
 156         switch (EXTRACT_32BITS(&slarp->code)) {
 157         case SLARP_REQUEST:
 158                 printf("request");
 159                 /*
 160                  * At least according to William "Chops" Westfield's
 161                  * message in
 162                  *
 163                  *      http://www.nethelp.no/net/cisco-hdlc.txt
 164                  *
 165                  * the address and mask aren't used in requests -
 166                  * they're just zero.
 167                  */
 168                 break;
 169         case SLARP_REPLY:
 170                 printf("reply %s/%s",
 171                         ipaddr_string(&slarp->un.addr.addr),
 172                         ipaddr_string(&slarp->un.addr.mask));
 173                 break;
 174         case SLARP_KEEPALIVE:
 175                 printf("keepalive: mineseen=0x%08x, yourseen=0x%08x, reliability=0x%04x",
 176                        EXTRACT_32BITS(&slarp->un.keep.myseq),
 177                        EXTRACT_32BITS(&slarp->un.keep.yourseq),
 178                        EXTRACT_16BITS(&slarp->un.keep.rel));
 179
 180                 if (length >= SLARP_MAX_LEN) { /* uptime-stamp is optional */
 181                         cp += SLARP_MIN_LEN;
 182                         if (!TTEST2(*cp, 4))
 183                                 goto trunc;
 184                         sec = EXTRACT_32BITS(cp) / 1000;
 185                         min = sec / 60; sec -= min * 60;
 186                         hrs = min / 60; min -= hrs * 60;
 187                         days = hrs / 24; hrs -= days * 24;
 188                         printf(", link uptime=%ud%uh%um%us",days,hrs,min,sec);
 189                 }
 190                 break;
 191         default:
 192                 printf("0x%02x unknown", EXTRACT_32BITS(&slarp->code));
 193                 if (vflag <= 1)
 194                     print_unknown_data(cp+4,"\n\t",length-4);
 195                 break;
 196         }
 197
 198         if (SLARP_MAX_LEN < length && vflag)
 199                 printf(", (trailing junk: %d bytes)", length - SLARP_MAX_LEN);
 200         if (vflag > 1)
 201             print_unknown_data(cp+4,"\n\t",length-4);
 202         return;
 203
 204 trunc:
 205         printf("[|slarp]");
 206 }
 207
 208
 209 /*
 210  * Local Variables:
 211  * c-style: whitesmith
 212  * c-basic-offset: 8
 213  * End:
 214  */