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[] =
  24     "@(#) $Header: /tcpdump/master/tcpdump/print-chdlc.c,v 1.20 2002-10-06 16:35:45 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 void
  47 chdlc_if_print(u_char *user _U_, const struct pcap_pkthdr *h,
  48              register const u_char *p)
  49 {
  50         register u_int length = h->len;
  51         register u_int caplen = h->caplen;
  52
  53         ++infodelay;
  54         ts_print(&h->ts);
  55
  56         /*
  57          * Some printers want to get back at the link level addresses,
  58          * and/or check that they're not walking off the end of the packet.
  59          * Rather than pass them all the way down, we set these globals.
  60          */
  61         packetp = p;
  62         snapend = p + caplen;
  63
  64         chdlc_print(p, length, caplen);
  65
  66         putchar('\n');
  67         --infodelay;
  68         if (infoprint)
  69                 info(0);
  70 }
  71
  72 void
  73 chdlc_print(register const u_char *p, u_int length, u_int caplen)
  74 {
  75         const struct ip *ip;
  76         u_int proto;
  77
  78         if (caplen < CHDLC_HDRLEN) {
  79                 printf("[|chdlc]");
  80                 return;
  81         }
  82
  83         proto = EXTRACT_16BITS(&p[2]);
  84         if (eflag) {
  85                 switch (p[0]) {
  86                 case CHDLC_UNICAST:
  87                         printf("unicast ");
  88                         break;
  89                 case CHDLC_BCAST:
  90                         printf("bcast ");
  91                         break;
  92                 default:
  93                         printf("0x%02x ", p[0]);
  94                         break;
  95                 }
  96                 printf("%d %04x: ", length, proto);
  97         }
  98
  99         length -= CHDLC_HDRLEN;
 100         ip = (const struct ip *)(p + CHDLC_HDRLEN);
 101         switch (proto) {
 102         case ETHERTYPE_IP:
 103                 ip_print((const u_char *)ip, length);
 104                 break;
 105 #ifdef INET6
 106         case ETHERTYPE_IPV6:
 107                 ip6_print((const u_char *)ip, length);
 108                 break;
 109 #endif
 110         case CHDLC_TYPE_SLARP:
 111                 chdlc_slarp_print((const u_char *)ip, length);
 112                 break;
 113 #if 0
 114         case CHDLC_TYPE_CDP:
 115                 chdlc_cdp_print((const u_char *)ip, length);
 116                 break;
 117 #endif
 118         case ETHERTYPE_ISO:
 119                 /* is the fudge byte set ? if yes lets skip a byte */
 120                 if (*(p+CHDLC_HDRLEN) == 0)
 121                     isoclns_print(p+CHDLC_HDRLEN+1, length-1, length-1, NULL, NULL);
 122                 else
 123                     isoclns_print(p+CHDLC_HDRLEN, length, length, NULL, NULL);
 124                 break;
 125         default:
 126                 printf("unknown CHDLC protocol (0x%04x)", proto);
 127                 break;
 128         }
 129         if (xflag)
 130                 default_print((const u_char *)ip, caplen - CHDLC_HDRLEN);
 131 }
 132
 133 struct cisco_slarp {
 134         u_int32_t code;
 135 #define SLARP_REQUEST   0
 136 #define SLARP_REPLY     1
 137 #define SLARP_KEEPALIVE 2
 138         union {
 139                 struct {
 140                         struct in_addr addr;
 141                         struct in_addr mask;
 142                         u_int16_t unused[3];
 143                 } addr;
 144                 struct {
 145                         u_int32_t myseq;
 146                         u_int32_t yourseq;
 147                         u_int16_t rel;
 148                         u_int16_t t1;
 149                         u_int16_t t2;
 150                 } keep;
 151         } un;
 152 };
 153
 154 #define SLARP_LEN       18
 155
 156 static void
 157 chdlc_slarp_print(const u_char *cp, u_int length)
 158 {
 159         const struct cisco_slarp *slarp;
 160
 161         if (length < SLARP_LEN) {
 162                 printf("[|slarp]");
 163                 return;
 164         }
 165
 166         slarp = (const struct cisco_slarp *)cp;
 167         printf("SLARP (length: %u), ",length);
 168         switch (ntohl(slarp->code)) {
 169         case SLARP_REQUEST:
 170                 printf("request");
 171                 /* ok we do not know it - but lets at least dump it */
 172                 print_unknown_data(cp+4,"\n\t",length-4);
 173                 break;
 174         case SLARP_REPLY:
 175                 printf("reply %s/%s",
 176                         ipaddr_string(&slarp->un.addr.addr),
 177                         ipaddr_string(&slarp->un.addr.mask));
 178                 break;
 179         case SLARP_KEEPALIVE:
 180                 printf("keepalive: mineseen=0x%08x yourseen=0x%08x ",
 181                         (u_int32_t)ntohl(slarp->un.keep.myseq),
 182                         (u_int32_t)ntohl(slarp->un.keep.yourseq));
 183                 printf("reliability=0x%04x t1=%d.%d",
 184                         ntohs(slarp->un.keep.rel), ntohs(slarp->un.keep.t1),
 185                         ntohs(slarp->un.keep.t2));
 186                 break;
 187         default:
 188                 printf("0x%02x unknown", (u_int32_t)ntohl(slarp->code));
 189                 if (vflag <= 1)
 190                     print_unknown_data(cp+4,"\n\t",length-4);
 191                 break;
 192         }
 193
 194         if (SLARP_LEN < length && vflag)
 195                 printf(", (trailing junk: %d bytes)", length - SLARP_LEN);
 196         if (vflag > 1)
 197             print_unknown_data(cp+4,"\n\t",length-4);
 198 }