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 const char tstr[] = "[|slip]";
  46
  47 static u_int lastlen[2][256];
  48 static u_int lastconn = 255;
  49
  50 static void sliplink_print(const u_char *, const struct ip *, u_int);
  51 static void compressed_sl_print(const u_char *, const struct ip *, u_int, int);
  52
  53 u_int
  54 sl_if_print(const struct pcap_pkthdr *h, const u_char *p)
  55 {
  56         register u_int caplen = h->caplen;
  57         register u_int length = h->len;
  58         register const struct ip *ip;
  59
  60         if (caplen < SLIP_HDRLEN) {
  61                 printf("%s", tstr);
  62                 return (caplen);
  63         }
  64
  65         length -= SLIP_HDRLEN;
  66
  67         ip = (struct ip *)(p + SLIP_HDRLEN);
  68
  69         if (eflag)
  70                 sliplink_print(p, ip, length);
  71
  72         switch (IP_V(ip)) {
  73         case 4:
  74                 ip_print(gndo, (u_char *)ip, length);
  75                 break;
  76 #ifdef INET6
  77         case 6:
  78                 ip6_print(gndo, (u_char *)ip, length);
  79                 break;
  80 #endif
  81         default:
  82                 printf ("ip v%d", IP_V(ip));
  83         }
  84
  85         return (SLIP_HDRLEN);
  86 }
  87
  88 u_int
  89 sl_bsdos_if_print(const struct pcap_pkthdr *h, const u_char *p)
  90 {
  91         register u_int caplen = h->caplen;
  92         register u_int length = h->len;
  93         register const struct ip *ip;
  94
  95         if (caplen < SLIP_HDRLEN) {
  96                 printf("%s", tstr);
  97                 return (caplen);
  98         }
  99
 100         length -= SLIP_HDRLEN;
 101
 102         ip = (struct ip *)(p + SLIP_HDRLEN);
 103
 104 #ifdef notdef
 105         if (eflag)
 106                 sliplink_print(p, ip, length);
 107 #endif
 108
 109         ip_print(gndo, (u_char *)ip, length);
 110
 111         return (SLIP_HDRLEN);
 112 }
 113
 114 static void
 115 sliplink_print(register const u_char *p, register const struct ip *ip,
 116                register u_int length)
 117 {
 118         int dir;
 119         u_int hlen;
 120
 121         dir = p[SLX_DIR];
 122         putchar(dir == SLIPDIR_IN ? 'I' : 'O');
 123         putchar(' ');
 124
 125         if (nflag) {
 126                 /* XXX just dump the header */
 127                 register int i;
 128
 129                 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
 130                         printf("%02x.", p[i]);
 131                 printf("%02x: ", p[SLX_CHDR + CHDR_LEN - 1]);
 132                 return;
 133         }
 134         switch (p[SLX_CHDR] & 0xf0) {
 135
 136         case TYPE_IP:
 137                 printf("ip %d: ", length + SLIP_HDRLEN);
 138                 break;
 139
 140         case TYPE_UNCOMPRESSED_TCP:
 141                 /*
 142                  * The connection id is stored in the IP protocol field.
 143                  * Get it from the link layer since sl_uncompress_tcp()
 144                  * has restored the IP header copy to IPPROTO_TCP.
 145                  */
 146                 lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p;
 147                 hlen = IP_HL(ip);
 148                 hlen += TH_OFF((struct tcphdr *)&((int *)ip)[hlen]);
 149                 lastlen[dir][lastconn] = length - (hlen << 2);
 150                 printf("utcp %d: ", lastconn);
 151                 break;
 152
 153         default:
 154                 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
 155                         compressed_sl_print(&p[SLX_CHDR], ip,
 156                             length, dir);
 157                         printf(": ");
 158                 } else
 159                         printf("slip-%d!: ", p[SLX_CHDR]);
 160         }
 161 }
 162
 163 static const u_char *
 164 print_sl_change(const char *str, register const u_char *cp)
 165 {
 166         register u_int i;
 167
 168         if ((i = *cp++) == 0) {
 169                 i = EXTRACT_16BITS(cp);
 170                 cp += 2;
 171         }
 172         printf(" %s%d", str, i);
 173         return (cp);
 174 }
 175
 176 static const u_char *
 177 print_sl_winchange(register const u_char *cp)
 178 {
 179         register short i;
 180
 181         if ((i = *cp++) == 0) {
 182                 i = EXTRACT_16BITS(cp);
 183                 cp += 2;
 184         }
 185         if (i >= 0)
 186                 printf(" W+%d", i);
 187         else
 188                 printf(" W%d", i);
 189         return (cp);
 190 }
 191
 192 static void
 193 compressed_sl_print(const u_char *chdr, const struct ip *ip,
 194                     u_int length, int dir)
 195 {
 196         register const u_char *cp = chdr;
 197         register u_int flags, hlen;
 198
 199         flags = *cp++;
 200         if (flags & NEW_C) {
 201                 lastconn = *cp++;
 202                 printf("ctcp %d", lastconn);
 203         } else
 204                 printf("ctcp *");
 205
 206         /* skip tcp checksum */
 207         cp += 2;
 208
 209         switch (flags & SPECIALS_MASK) {
 210         case SPECIAL_I:
 211                 printf(" *SA+%d", lastlen[dir][lastconn]);
 212                 break;
 213
 214         case SPECIAL_D:
 215                 printf(" *S+%d", lastlen[dir][lastconn]);
 216                 break;
 217
 218         default:
 219                 if (flags & NEW_U)
 220                         cp = print_sl_change("U=", cp);
 221                 if (flags & NEW_W)
 222                         cp = print_sl_winchange(cp);
 223                 if (flags & NEW_A)
 224                         cp = print_sl_change("A+", cp);
 225                 if (flags & NEW_S)
 226                         cp = print_sl_change("S+", cp);
 227                 break;
 228         }
 229         if (flags & NEW_I)
 230                 cp = print_sl_change("I+", cp);
 231
 232         /*
 233          * 'hlen' is the length of the uncompressed TCP/IP header (in words).
 234          * 'cp - chdr' is the length of the compressed header.
 235          * 'length - hlen' is the amount of data in the packet.
 236          */
 237         hlen = IP_HL(ip);
 238         hlen += TH_OFF((struct tcphdr *)&((int32_t *)ip)[hlen]);
 239         lastlen[dir][lastconn] = length - (hlen << 2);
 240         printf(" %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr));
 241 }