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 <pcap.h>
  29 #include <stdio.h>
  30
  31 #include "interface.h"
  32 #include "addrtoname.h"
  33 #include "extract.h"                    /* must come after interface.h */
  34
  35 #include "ip.h"
  36 #include "tcp.h"
  37 #include "slcompress.h"
  38
  39 /*
  40  * definitions of the pseudo- link-level header attached to slip
  41  * packets grabbed by the packet filter (bpf) traffic monitor.
  42  */
  43 #define SLIP_HDRLEN 16
  44
  45 #define SLX_DIR 0
  46 #define SLX_CHDR 1
  47 #define CHDR_LEN 15
  48
  49 #define SLIPDIR_IN 0
  50 #define SLIPDIR_OUT 1
  51
  52 static const char tstr[] = "[|slip]";
  53
  54 static u_int lastlen[2][256];
  55 static u_int lastconn = 255;
  56
  57 static void sliplink_print(const u_char *, const struct ip *, u_int);
  58 static void compressed_sl_print(const u_char *, const struct ip *, u_int, int);
  59
  60 u_int
  61 sl_if_print(const struct pcap_pkthdr *h, const u_char *p)
  62 {
  63         register u_int caplen = h->caplen;
  64         register u_int length = h->len;
  65         register const struct ip *ip;
  66
  67         if (caplen < SLIP_HDRLEN) {
  68                 printf("%s", tstr);
  69                 return (caplen);
  70         }
  71
  72         length -= SLIP_HDRLEN;
  73
  74         ip = (struct ip *)(p + SLIP_HDRLEN);
  75
  76         if (eflag)
  77                 sliplink_print(p, ip, length);
  78
  79         switch (IP_V(ip)) {
  80         case 4:
  81                 ip_print(gndo, (u_char *)ip, length);
  82                 break;
  83 #ifdef INET6
  84         case 6:
  85                 ip6_print(gndo, (u_char *)ip, length);
  86                 break;
  87 #endif
  88         default:
  89                 printf ("ip v%d", IP_V(ip));
  90         }
  91
  92         return (SLIP_HDRLEN);
  93 }
  94
  95 u_int
  96 sl_bsdos_if_print(const struct pcap_pkthdr *h, const u_char *p)
  97 {
  98         register u_int caplen = h->caplen;
  99         register u_int length = h->len;
 100         register const struct ip *ip;
 101
 102         if (caplen < SLIP_HDRLEN) {
 103                 printf("%s", tstr);
 104                 return (caplen);
 105         }
 106
 107         length -= SLIP_HDRLEN;
 108
 109         ip = (struct ip *)(p + SLIP_HDRLEN);
 110
 111 #ifdef notdef
 112         if (eflag)
 113                 sliplink_print(p, ip, length);
 114 #endif
 115
 116         ip_print(gndo, (u_char *)ip, length);
 117
 118         return (SLIP_HDRLEN);
 119 }
 120
 121 static void
 122 sliplink_print(register const u_char *p, register const struct ip *ip,
 123                register u_int length)
 124 {
 125         int dir;
 126         u_int hlen;
 127
 128         dir = p[SLX_DIR];
 129         putchar(dir == SLIPDIR_IN ? 'I' : 'O');
 130         putchar(' ');
 131
 132         if (nflag) {
 133                 /* XXX just dump the header */
 134                 register int i;
 135
 136                 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
 137                         printf("%02x.", p[i]);
 138                 printf("%02x: ", p[SLX_CHDR + CHDR_LEN - 1]);
 139                 return;
 140         }
 141         switch (p[SLX_CHDR] & 0xf0) {
 142
 143         case TYPE_IP:
 144                 printf("ip %d: ", length + SLIP_HDRLEN);
 145                 break;
 146
 147         case TYPE_UNCOMPRESSED_TCP:
 148                 /*
 149                  * The connection id is stored in the IP protocol field.
 150                  * Get it from the link layer since sl_uncompress_tcp()
 151                  * has restored the IP header copy to IPPROTO_TCP.
 152                  */
 153                 lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p;
 154                 hlen = IP_HL(ip);
 155                 hlen += TH_OFF((struct tcphdr *)&((int *)ip)[hlen]);
 156                 lastlen[dir][lastconn] = length - (hlen << 2);
 157                 printf("utcp %d: ", lastconn);
 158                 break;
 159
 160         default:
 161                 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
 162                         compressed_sl_print(&p[SLX_CHDR], ip,
 163                             length, dir);
 164                         printf(": ");
 165                 } else
 166                         printf("slip-%d!: ", p[SLX_CHDR]);
 167         }
 168 }
 169
 170 static const u_char *
 171 print_sl_change(const char *str, register const u_char *cp)
 172 {
 173         register u_int i;
 174
 175         if ((i = *cp++) == 0) {
 176                 i = EXTRACT_16BITS(cp);
 177                 cp += 2;
 178         }
 179         printf(" %s%d", str, i);
 180         return (cp);
 181 }
 182
 183 static const u_char *
 184 print_sl_winchange(register const u_char *cp)
 185 {
 186         register short i;
 187
 188         if ((i = *cp++) == 0) {
 189                 i = EXTRACT_16BITS(cp);
 190                 cp += 2;
 191         }
 192         if (i >= 0)
 193                 printf(" W+%d", i);
 194         else
 195                 printf(" W%d", i);
 196         return (cp);
 197 }
 198
 199 static void
 200 compressed_sl_print(const u_char *chdr, const struct ip *ip,
 201                     u_int length, int dir)
 202 {
 203         register const u_char *cp = chdr;
 204         register u_int flags, hlen;
 205
 206         flags = *cp++;
 207         if (flags & NEW_C) {
 208                 lastconn = *cp++;
 209                 printf("ctcp %d", lastconn);
 210         } else
 211                 printf("ctcp *");
 212
 213         /* skip tcp checksum */
 214         cp += 2;
 215
 216         switch (flags & SPECIALS_MASK) {
 217         case SPECIAL_I:
 218                 printf(" *SA+%d", lastlen[dir][lastconn]);
 219                 break;
 220
 221         case SPECIAL_D:
 222                 printf(" *S+%d", lastlen[dir][lastconn]);
 223                 break;
 224
 225         default:
 226                 if (flags & NEW_U)
 227                         cp = print_sl_change("U=", cp);
 228                 if (flags & NEW_W)
 229                         cp = print_sl_winchange(cp);
 230                 if (flags & NEW_A)
 231                         cp = print_sl_change("A+", cp);
 232                 if (flags & NEW_S)
 233                         cp = print_sl_change("S+", cp);
 234                 break;
 235         }
 236         if (flags & NEW_I)
 237                 cp = print_sl_change("I+", cp);
 238
 239         /*
 240          * 'hlen' is the length of the uncompressed TCP/IP header (in words).
 241          * 'cp - chdr' is the length of the compressed header.
 242          * 'length - hlen' is the amount of data in the packet.
 243          */
 244         hlen = IP_HL(ip);
 245         hlen += TH_OFF((struct tcphdr *)&((int32_t *)ip)[hlen]);
 246         lastlen[dir][lastconn] = length - (hlen << 2);
 247         printf(" %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr));
 248 }