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 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 #include <tcpdump-stdinc.h>
  27
  28 #include <stdio.h>
  29
  30 #include "interface.h"
  31 #include "extract.h"                    /* must come after interface.h */
  32
  33 #include "ip.h"
  34 #include "tcp.h"
  35 #include "slcompress.h"
  36
  37 /*
  38  * definitions of the pseudo- link-level header attached to slip
  39  * packets grabbed by the packet filter (bpf) traffic monitor.
  40  */
  41 #define SLIP_HDRLEN 16
  42
  43 #define SLX_DIR 0
  44 #define SLX_CHDR 1
  45 #define CHDR_LEN 15
  46
  47 #define SLIPDIR_IN 0
  48 #define SLIPDIR_OUT 1
  49
  50 static const char tstr[] = "[|slip]";
  51
  52 static u_int lastlen[2][256];
  53 static u_int lastconn = 255;
  54
  55 static void sliplink_print(const u_char *, const struct ip *, u_int);
  56 static void compressed_sl_print(const u_char *, const struct ip *, u_int, int);
  57
  58 u_int
  59 sl_if_print(const struct pcap_pkthdr *h, const u_char *p)
  60 {
  61         register u_int caplen = h->caplen;
  62         register u_int length = h->len;
  63         register const struct ip *ip;
  64
  65         if (caplen < SLIP_HDRLEN) {
  66                 printf("%s", tstr);
  67                 return (caplen);
  68         }
  69
  70         length -= SLIP_HDRLEN;
  71
  72         ip = (struct ip *)(p + SLIP_HDRLEN);
  73
  74         if (eflag)
  75                 sliplink_print(p, ip, length);
  76
  77         switch (IP_V(ip)) {
  78         case 4:
  79                 ip_print(gndo, (u_char *)ip, length);
  80                 break;
  81 #ifdef INET6
  82         case 6:
  83                 ip6_print(gndo, (u_char *)ip, length);
  84                 break;
  85 #endif
  86         default:
  87                 printf ("ip v%d", IP_V(ip));
  88         }
  89
  90         return (SLIP_HDRLEN);
  91 }
  92
  93 u_int
  94 sl_bsdos_if_print(const struct pcap_pkthdr *h, const u_char *p)
  95 {
  96         register u_int caplen = h->caplen;
  97         register u_int length = h->len;
  98         register const struct ip *ip;
  99
 100         if (caplen < SLIP_HDRLEN) {
 101                 printf("%s", tstr);
 102                 return (caplen);
 103         }
 104
 105         length -= SLIP_HDRLEN;
 106
 107         ip = (struct ip *)(p + SLIP_HDRLEN);
 108
 109 #ifdef notdef
 110         if (eflag)
 111                 sliplink_print(p, ip, length);
 112 #endif
 113
 114         ip_print(gndo, (u_char *)ip, length);
 115
 116         return (SLIP_HDRLEN);
 117 }
 118
 119 static void
 120 sliplink_print(register const u_char *p, register const struct ip *ip,
 121                register u_int length)
 122 {
 123         int dir;
 124         u_int hlen;
 125
 126         dir = p[SLX_DIR];
 127         putchar(dir == SLIPDIR_IN ? 'I' : 'O');
 128         putchar(' ');
 129
 130         if (nflag) {
 131                 /* XXX just dump the header */
 132                 register int i;
 133
 134                 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
 135                         printf("%02x.", p[i]);
 136                 printf("%02x: ", p[SLX_CHDR + CHDR_LEN - 1]);
 137                 return;
 138         }
 139         switch (p[SLX_CHDR] & 0xf0) {
 140
 141         case TYPE_IP:
 142                 printf("ip %d: ", length + SLIP_HDRLEN);
 143                 break;
 144
 145         case TYPE_UNCOMPRESSED_TCP:
 146                 /*
 147                  * The connection id is stored in the IP protocol field.
 148                  * Get it from the link layer since sl_uncompress_tcp()
 149                  * has restored the IP header copy to IPPROTO_TCP.
 150                  */
 151                 lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p;
 152                 hlen = IP_HL(ip);
 153                 hlen += TH_OFF((struct tcphdr *)&((int *)ip)[hlen]);
 154                 lastlen[dir][lastconn] = length - (hlen << 2);
 155                 printf("utcp %d: ", lastconn);
 156                 break;
 157
 158         default:
 159                 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
 160                         compressed_sl_print(&p[SLX_CHDR], ip,
 161                             length, dir);
 162                         printf(": ");
 163                 } else
 164                         printf("slip-%d!: ", p[SLX_CHDR]);
 165         }
 166 }
 167
 168 static const u_char *
 169 print_sl_change(const char *str, register const u_char *cp)
 170 {
 171         register u_int i;
 172
 173         if ((i = *cp++) == 0) {
 174                 i = EXTRACT_16BITS(cp);
 175                 cp += 2;
 176         }
 177         printf(" %s%d", str, i);
 178         return (cp);
 179 }
 180
 181 static const u_char *
 182 print_sl_winchange(register const u_char *cp)
 183 {
 184         register short i;
 185
 186         if ((i = *cp++) == 0) {
 187                 i = EXTRACT_16BITS(cp);
 188                 cp += 2;
 189         }
 190         if (i >= 0)
 191                 printf(" W+%d", i);
 192         else
 193                 printf(" W%d", i);
 194         return (cp);
 195 }
 196
 197 static void
 198 compressed_sl_print(const u_char *chdr, const struct ip *ip,
 199                     u_int length, int dir)
 200 {
 201         register const u_char *cp = chdr;
 202         register u_int flags, hlen;
 203
 204         flags = *cp++;
 205         if (flags & NEW_C) {
 206                 lastconn = *cp++;
 207                 printf("ctcp %d", lastconn);
 208         } else
 209                 printf("ctcp *");
 210
 211         /* skip tcp checksum */
 212         cp += 2;
 213
 214         switch (flags & SPECIALS_MASK) {
 215         case SPECIAL_I:
 216                 printf(" *SA+%d", lastlen[dir][lastconn]);
 217                 break;
 218
 219         case SPECIAL_D:
 220                 printf(" *S+%d", lastlen[dir][lastconn]);
 221                 break;
 222
 223         default:
 224                 if (flags & NEW_U)
 225                         cp = print_sl_change("U=", cp);
 226                 if (flags & NEW_W)
 227                         cp = print_sl_winchange(cp);
 228                 if (flags & NEW_A)
 229                         cp = print_sl_change("A+", cp);
 230                 if (flags & NEW_S)
 231                         cp = print_sl_change("S+", cp);
 232                 break;
 233         }
 234         if (flags & NEW_I)
 235                 cp = print_sl_change("I+", cp);
 236
 237         /*
 238          * 'hlen' is the length of the uncompressed TCP/IP header (in words).
 239          * 'cp - chdr' is the length of the compressed header.
 240          * 'length - hlen' is the amount of data in the packet.
 241          */
 242         hlen = IP_HL(ip);
 243         hlen += TH_OFF((struct tcphdr *)&((int32_t *)ip)[hlen]);
 244         lastlen[dir][lastconn] = length - (hlen << 2);
 245         printf(" %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr));
 246 }