external/bsd/tcpdump/dist/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 #include <sys/cdefs.h>
  23 #ifndef lint
  24 __RCSID("$NetBSD: print-sl.c,v 1.5 2015/03/31 21:59:35 christos Exp $");
  25 #endif
  26
  27 #define NETDISSECT_REWORKED
  28 #ifdef HAVE_CONFIG_H
  29 #include "config.h"
  30 #endif
  31
  32 #include <tcpdump-stdinc.h>
  33
  34 #include "interface.h"
  35 #include "extract.h"                    /* must come after interface.h */
  36
  37 #include "ip.h"
  38 #include "tcp.h"
  39 #include "slcompress.h"
  40
  41 /*
  42  * definitions of the pseudo- link-level header attached to slip
  43  * packets grabbed by the packet filter (bpf) traffic monitor.
  44  */
  45 #define SLIP_HDRLEN 16
  46
  47 #define SLX_DIR 0
  48 #define SLX_CHDR 1
  49 #define CHDR_LEN 15
  50
  51 #define SLIPDIR_IN 0
  52 #define SLIPDIR_OUT 1
  53
  54 static const char tstr[] = "[|slip]";
  55
  56 static u_int lastlen[2][256];
  57 static u_int lastconn = 255;
  58
  59 static void sliplink_print(netdissect_options *, const u_char *, const struct ip *, u_int);
  60 static void compressed_sl_print(netdissect_options *, const u_char *, const struct ip *, u_int, int);
  61
  62 u_int
  63 sl_if_print(netdissect_options *ndo,
  64             const struct pcap_pkthdr *h, const u_char *p)
  65 {
  66         register u_int caplen = h->caplen;
  67         register u_int length = h->len;
  68         register const struct ip *ip;
  69
  70         if (caplen < SLIP_HDRLEN || length < SLIP_HDRLEN) {
  71                 ND_PRINT((ndo, "%s", tstr));
  72                 return (caplen);
  73         }
  74
  75         length -= SLIP_HDRLEN;
  76
  77         ip = (struct ip *)(p + SLIP_HDRLEN);
  78
  79         if (ndo->ndo_eflag)
  80                 sliplink_print(ndo, p, ip, length);
  81
  82         switch (IP_V(ip)) {
  83         case 4:
  84                 ip_print(ndo, (u_char *)ip, length);
  85                 break;
  86         case 6:
  87                 ip6_print(ndo, (u_char *)ip, length);
  88                 break;
  89         default:
  90                 ND_PRINT((ndo, "ip v%d", IP_V(ip)));
  91         }
  92
  93         return (SLIP_HDRLEN);
  94 }
  95
  96 u_int
  97 sl_bsdos_if_print(netdissect_options *ndo,
  98                   const struct pcap_pkthdr *h, const u_char *p)
  99 {
 100         register u_int caplen = h->caplen;
 101         register u_int length = h->len;
 102         register const struct ip *ip;
 103
 104         if (caplen < SLIP_HDRLEN) {
 105                 ND_PRINT((ndo, "%s", tstr));
 106                 return (caplen);
 107         }
 108
 109         length -= SLIP_HDRLEN;
 110
 111         ip = (struct ip *)(p + SLIP_HDRLEN);
 112
 113 #ifdef notdef
 114         if (ndo->ndo_eflag)
 115                 sliplink_print(ndo, p, ip, length);
 116 #endif
 117
 118         ip_print(ndo, (u_char *)ip, length);
 119
 120         return (SLIP_HDRLEN);
 121 }
 122
 123 static void
 124 sliplink_print(netdissect_options *ndo,
 125                register const u_char *p, register const struct ip *ip,
 126                register u_int length)
 127 {
 128         int dir;
 129         u_int hlen;
 130
 131         dir = p[SLX_DIR];
 132         ND_PRINT((ndo, dir == SLIPDIR_IN ? "I " : "O "));
 133
 134         if (ndo->ndo_nflag) {
 135                 /* XXX just dump the header */
 136                 register int i;
 137
 138                 for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
 139                         ND_PRINT((ndo, "%02x.", p[i]));
 140                 ND_PRINT((ndo, "%02x: ", p[SLX_CHDR + CHDR_LEN - 1]));
 141                 return;
 142         }
 143         switch (p[SLX_CHDR] & 0xf0) {
 144
 145         case TYPE_IP:
 146                 ND_PRINT((ndo, "ip %d: ", length + SLIP_HDRLEN));
 147                 break;
 148
 149         case TYPE_UNCOMPRESSED_TCP:
 150                 /*
 151                  * The connection id is stored in the IP protocol field.
 152                  * Get it from the link layer since sl_uncompress_tcp()
 153                  * has restored the IP header copy to IPPROTO_TCP.
 154                  */
 155                 lastconn = ((struct ip *)&p[SLX_CHDR])->ip_p;
 156                 hlen = IP_HL(ip);
 157                 hlen += TH_OFF((struct tcphdr *)&((int *)ip)[hlen]);
 158                 lastlen[dir][lastconn] = length - (hlen << 2);
 159                 ND_PRINT((ndo, "utcp %d: ", lastconn));
 160                 break;
 161
 162         default:
 163                 if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
 164                         compressed_sl_print(ndo, &p[SLX_CHDR], ip,
 165                             length, dir);
 166                         ND_PRINT((ndo, ": "));
 167                 } else
 168                         ND_PRINT((ndo, "slip-%d!: ", p[SLX_CHDR]));
 169         }
 170 }
 171
 172 static const u_char *
 173 print_sl_change(netdissect_options *ndo,
 174                 const char *str, register const u_char *cp)
 175 {
 176         register u_int i;
 177
 178         if ((i = *cp++) == 0) {
 179                 i = EXTRACT_16BITS(cp);
 180                 cp += 2;
 181         }
 182         ND_PRINT((ndo, " %s%d", str, i));
 183         return (cp);
 184 }
 185
 186 static const u_char *
 187 print_sl_winchange(netdissect_options *ndo,
 188                    register const u_char *cp)
 189 {
 190         register short i;
 191
 192         if ((i = *cp++) == 0) {
 193                 i = EXTRACT_16BITS(cp);
 194                 cp += 2;
 195         }
 196         if (i >= 0)
 197                 ND_PRINT((ndo, " W+%d", i));
 198         else
 199                 ND_PRINT((ndo, " W%d", i));
 200         return (cp);
 201 }
 202
 203 static void
 204 compressed_sl_print(netdissect_options *ndo,
 205                     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                 ND_PRINT((ndo, "ctcp %d", lastconn));
 215         } else
 216                 ND_PRINT((ndo, "ctcp *"));
 217
 218         /* skip tcp checksum */
 219         cp += 2;
 220
 221         switch (flags & SPECIALS_MASK) {
 222         case SPECIAL_I:
 223                 ND_PRINT((ndo, " *SA+%d", lastlen[dir][lastconn]));
 224                 break;
 225
 226         case SPECIAL_D:
 227                 ND_PRINT((ndo, " *S+%d", lastlen[dir][lastconn]));
 228                 break;
 229
 230         default:
 231                 if (flags & NEW_U)
 232                         cp = print_sl_change(ndo, "U=", cp);
 233                 if (flags & NEW_W)
 234                         cp = print_sl_winchange(ndo, cp);
 235                 if (flags & NEW_A)
 236                         cp = print_sl_change(ndo, "A+", cp);
 237                 if (flags & NEW_S)
 238                         cp = print_sl_change(ndo, "S+", cp);
 239                 break;
 240         }
 241         if (flags & NEW_I)
 242                 cp = print_sl_change(ndo, "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         ND_PRINT((ndo, " %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr)));
 253 }