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

   1 /*
   2  * Copyright (c) 1989, 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-sl.c,v 1.65 2005-04-06 21:32:42 mcr 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 "extract.h"                    /* must come after interface.h */
  39
  40 #include "ip.h"
  41 #include "tcp.h"
  42 #include "slip.h"
  43 #include "slcompress.h"
  44
  45 static u_int lastlen[2][256];
  46 static u_int lastconn = 255;
  47
  48 static void sliplink_print(const u_char *, const struct ip *, u_int);
  49 static void compressed_sl_print(const u_char *, const struct ip *, u_int, int);
  50
  51 u_int
  52 sl_if_print(const struct pcap_pkthdr *h, const u_char *p)
  53 {
  54         register u_int caplen = h->caplen;
  55         register u_int length = h->len;
  56         register const struct ip *ip;
  57
  58         if (caplen < SLIP_HDRLEN) {
  59                 printf("[|slip]");
  60                 return (caplen);
  61         }
  62
  63         length -= SLIP_HDRLEN;
  64
  65         ip = (struct ip *)(p + SLIP_HDRLEN);
  66
  67         if (eflag)
  68                 sliplink_print(p, ip, length);
  69
  70         switch (IP_V(ip)) {
  71         case 4:
  72                 ip_print(gndo, (u_char *)ip, length);
  73                 break;
  74 #ifdef INET6
  75         case 6:
  76                 ip6_print(gndo, (u_char *)ip, length);
  77                 break;
  78 #endif
  79         default:
  80                 printf ("ip v%d", IP_V(ip));
  81         }
  82
  83         return (SLIP_HDRLEN);
  84 }
  85
  86 u_int
  87 sl_bsdos_if_print(const struct pcap_pkthdr *h, const u_char *p)
  88 {
  89         register u_int caplen = h->caplen;
  90         register u_int length = h->len;
  91         register const struct ip *ip;
  92
  93         if (caplen < SLIP_HDRLEN) {
  94                 printf("[|slip]");
  95                 return (caplen);
  96         }
  97
  98         length -= SLIP_HDRLEN;
  99
 100         ip = (struct ip *)(p + SLIP_HDRLEN);
 101
 102 #ifdef notdef
 103         if (eflag)
 104                 sliplink_print(p, ip, length);
 105 #endif
 106
 107         ip_print(gndo, (u_char *)ip, length);
 108
 109         return (SLIP_HDRLEN);
 110 }
 111
 112 static void
 113 sliplink_print(register const u_char *p, register const struct ip *ip,
 114                register u_int length)
 115 {
 116         int dir;
 117         u_int hlen;
 118
 119         dir = p[SLX_DIR];
 120         putchar(dir == SLIPDIR_IN ? 'I' : 'O');
 121         putchar(' ');
 122
 123         if (nflag) {
 124                 /* XXX just dump the header */
 125                 register int i;
 126
 127                 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
 128                         printf("%02x.", p[i]);
 129                 printf("%02x: ", p[SLX_CHDR + CHDR_LEN - 1]);
 130                 return;
 131         }
 132         switch (p[SLX_CHDR] & 0xf0) {
 133
 134         case TYPE_IP:
 135                 printf("ip %d: ", length + SLIP_HDRLEN);
 136                 break;
 137
 138         case TYPE_UNCOMPRESSED_TCP:
 139                 /*
 140                  * The connection id is stored in the IP protocol field.
 141                  * Get it from the link layer since sl_uncompress_tcp()
 142                  * has restored the IP header copy to IPPROTO_TCP.
 143                  */
 144                 lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p;
 145                 hlen = IP_HL(ip);
 146                 hlen += TH_OFF((struct tcphdr *)&((int *)ip)[hlen]);
 147                 lastlen[dir][lastconn] = length - (hlen << 2);
 148                 printf("utcp %d: ", lastconn);
 149                 break;
 150
 151         default:
 152                 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
 153                         compressed_sl_print(&p[SLX_CHDR], ip,
 154                             length, dir);
 155                         printf(": ");
 156                 } else
 157                         printf("slip-%d!: ", p[SLX_CHDR]);
 158         }
 159 }
 160
 161 static const u_char *
 162 print_sl_change(const char *str, register const u_char *cp)
 163 {
 164         register u_int i;
 165
 166         if ((i = *cp++) == 0) {
 167                 i = EXTRACT_16BITS(cp);
 168                 cp += 2;
 169         }
 170         printf(" %s%d", str, i);
 171         return (cp);
 172 }
 173
 174 static const u_char *
 175 print_sl_winchange(register const u_char *cp)
 176 {
 177         register short i;
 178
 179         if ((i = *cp++) == 0) {
 180                 i = EXTRACT_16BITS(cp);
 181                 cp += 2;
 182         }
 183         if (i >= 0)
 184                 printf(" W+%d", i);
 185         else
 186                 printf(" W%d", i);
 187         return (cp);
 188 }
 189
 190 static void
 191 compressed_sl_print(const u_char *chdr, const struct ip *ip,
 192                     u_int length, int dir)
 193 {
 194         register const u_char *cp = chdr;
 195         register u_int flags, hlen;
 196
 197         flags = *cp++;
 198         if (flags & NEW_C) {
 199                 lastconn = *cp++;
 200                 printf("ctcp %d", lastconn);
 201         } else
 202                 printf("ctcp *");
 203
 204         /* skip tcp checksum */
 205         cp += 2;
 206
 207         switch (flags & SPECIALS_MASK) {
 208         case SPECIAL_I:
 209                 printf(" *SA+%d", lastlen[dir][lastconn]);
 210                 break;
 211
 212         case SPECIAL_D:
 213                 printf(" *S+%d", lastlen[dir][lastconn]);
 214                 break;
 215
 216         default:
 217                 if (flags & NEW_U)
 218                         cp = print_sl_change("U=", cp);
 219                 if (flags & NEW_W)
 220                         cp = print_sl_winchange(cp);
 221                 if (flags & NEW_A)
 222                         cp = print_sl_change("A+", cp);
 223                 if (flags & NEW_S)
 224                         cp = print_sl_change("S+", cp);
 225                 break;
 226         }
 227         if (flags & NEW_I)
 228                 cp = print_sl_change("I+", cp);
 229
 230         /*
 231          * 'hlen' is the length of the uncompressed TCP/IP header (in words).
 232          * 'cp - chdr' is the length of the compressed header.
 233          * 'length - hlen' is the amount of data in the packet.
 234          */
 235         hlen = IP_HL(ip);
 236         hlen += TH_OFF((struct tcphdr *)&((int32_t *)ip)[hlen]);
 237         lastlen[dir][lastconn] = length - (hlen << 2);
 238         printf(" %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr));
 239 }