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 "slcompress.h"
  43
  44 /*
  45  * definitions of the pseudo- link-level header attached to slip
  46  * packets grabbed by the packet filter (bpf) traffic monitor.
  47  */
  48 #define SLIP_HDRLEN 16
  49
  50 #define SLX_DIR 0
  51 #define SLX_CHDR 1
  52 #define CHDR_LEN 15
  53
  54 #define SLIPDIR_IN 0
  55 #define SLIPDIR_OUT 1
  56
  57 static const char tstr[] = "[|slip]";
  58
  59 static u_int lastlen[2][256];
  60 static u_int lastconn = 255;
  61
  62 static void sliplink_print(const u_char *, const struct ip *, u_int);
  63 static void compressed_sl_print(const u_char *, const struct ip *, u_int, int);
  64
  65 u_int
  66 sl_if_print(const struct pcap_pkthdr *h, const u_char *p)
  67 {
  68         register u_int caplen = h->caplen;
  69         register u_int length = h->len;
  70         register const struct ip *ip;
  71
  72         if (caplen < SLIP_HDRLEN) {
  73                 printf("%s", tstr);
  74                 return (caplen);
  75         }
  76
  77         length -= SLIP_HDRLEN;
  78
  79         ip = (struct ip *)(p + SLIP_HDRLEN);
  80
  81         if (eflag)
  82                 sliplink_print(p, ip, length);
  83
  84         switch (IP_V(ip)) {
  85         case 4:
  86                 ip_print(gndo, (u_char *)ip, length);
  87                 break;
  88 #ifdef INET6
  89         case 6:
  90                 ip6_print(gndo, (u_char *)ip, length);
  91                 break;
  92 #endif
  93         default:
  94                 printf ("ip v%d", IP_V(ip));
  95         }
  96
  97         return (SLIP_HDRLEN);
  98 }
  99
 100 u_int
 101 sl_bsdos_if_print(const struct pcap_pkthdr *h, const u_char *p)
 102 {
 103         register u_int caplen = h->caplen;
 104         register u_int length = h->len;
 105         register const struct ip *ip;
 106
 107         if (caplen < SLIP_HDRLEN) {
 108                 printf("%s", tstr);
 109                 return (caplen);
 110         }
 111
 112         length -= SLIP_HDRLEN;
 113
 114         ip = (struct ip *)(p + SLIP_HDRLEN);
 115
 116 #ifdef notdef
 117         if (eflag)
 118                 sliplink_print(p, ip, length);
 119 #endif
 120
 121         ip_print(gndo, (u_char *)ip, length);
 122
 123         return (SLIP_HDRLEN);
 124 }
 125
 126 static void
 127 sliplink_print(register const u_char *p, register const struct ip *ip,
 128                register u_int length)
 129 {
 130         int dir;
 131         u_int hlen;
 132
 133         dir = p[SLX_DIR];
 134         putchar(dir == SLIPDIR_IN ? 'I' : 'O');
 135         putchar(' ');
 136
 137         if (nflag) {
 138                 /* XXX just dump the header */
 139                 register int i;
 140
 141                 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
 142                         printf("%02x.", p[i]);
 143                 printf("%02x: ", p[SLX_CHDR + CHDR_LEN - 1]);
 144                 return;
 145         }
 146         switch (p[SLX_CHDR] & 0xf0) {
 147
 148         case TYPE_IP:
 149                 printf("ip %d: ", length + SLIP_HDRLEN);
 150                 break;
 151
 152         case TYPE_UNCOMPRESSED_TCP:
 153                 /*
 154                  * The connection id is stored in the IP protocol field.
 155                  * Get it from the link layer since sl_uncompress_tcp()
 156                  * has restored the IP header copy to IPPROTO_TCP.
 157                  */
 158                 lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p;
 159                 hlen = IP_HL(ip);
 160                 hlen += TH_OFF((struct tcphdr *)&((int *)ip)[hlen]);
 161                 lastlen[dir][lastconn] = length - (hlen << 2);
 162                 printf("utcp %d: ", lastconn);
 163                 break;
 164
 165         default:
 166                 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
 167                         compressed_sl_print(&p[SLX_CHDR], ip,
 168                             length, dir);
 169                         printf(": ");
 170                 } else
 171                         printf("slip-%d!: ", p[SLX_CHDR]);
 172         }
 173 }
 174
 175 static const u_char *
 176 print_sl_change(const char *str, register const u_char *cp)
 177 {
 178         register u_int i;
 179
 180         if ((i = *cp++) == 0) {
 181                 i = EXTRACT_16BITS(cp);
 182                 cp += 2;
 183         }
 184         printf(" %s%d", str, i);
 185         return (cp);
 186 }
 187
 188 static const u_char *
 189 print_sl_winchange(register const u_char *cp)
 190 {
 191         register short i;
 192
 193         if ((i = *cp++) == 0) {
 194                 i = EXTRACT_16BITS(cp);
 195                 cp += 2;
 196         }
 197         if (i >= 0)
 198                 printf(" W+%d", i);
 199         else
 200                 printf(" W%d", i);
 201         return (cp);
 202 }
 203
 204 static void
 205 compressed_sl_print(const u_char *chdr, const struct ip *ip,
 206                     u_int length, int dir)
 207 {
 208         register const u_char *cp = chdr;
 209         register u_int flags, hlen;
 210
 211         flags = *cp++;
 212         if (flags & NEW_C) {
 213                 lastconn = *cp++;
 214                 printf("ctcp %d", lastconn);
 215         } else
 216                 printf("ctcp *");
 217
 218         /* skip tcp checksum */
 219         cp += 2;
 220
 221         switch (flags & SPECIALS_MASK) {
 222         case SPECIAL_I:
 223                 printf(" *SA+%d", lastlen[dir][lastconn]);
 224                 break;
 225
 226         case SPECIAL_D:
 227                 printf(" *S+%d", lastlen[dir][lastconn]);
 228                 break;
 229
 230         default:
 231                 if (flags & NEW_U)
 232                         cp = print_sl_change("U=", cp);
 233                 if (flags & NEW_W)
 234                         cp = print_sl_winchange(cp);
 235                 if (flags & NEW_A)
 236                         cp = print_sl_change("A+", cp);
 237                 if (flags & NEW_S)
 238                         cp = print_sl_change("S+", cp);
 239                 break;
 240         }
 241         if (flags & NEW_I)
 242                 cp = print_sl_change("I+", cp);
 243
 244         /*
 245          * 'hlen' is the length of the uncompressed TCP/IP header (in words).
 246          * 'cp - chdr' is the length of the compressed header.
 247          * 'length - hlen' is the amount of data in the packet.
 248          */
 249         hlen = IP_HL(ip);
 250         hlen += TH_OFF((struct tcphdr *)&((int32_t *)ip)[hlen]);
 251         lastlen[dir][lastconn] = length - (hlen << 2);
 252         printf(" %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr));
 253 }