dist/tcpdump/print-telnet.c

   1 /*      $NetBSD: print-telnet.c,v 1.5 2007/07/24 11:53:48 drochner Exp $        */
   2
   3 /*-
   4  * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Simon J. Gerraty.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31 /*
  32  *      @(#)Copyright (c) 1994, Simon J. Gerraty.
  33  *
  34  *      This is free software.  It comes with NO WARRANTY.
  35  *      Permission to use, modify and distribute this source code
  36  *      is granted subject to the following conditions.
  37  *      1/ that the above copyright notice and this notice
  38  *      are preserved in all copies.
  39  */
  40
  41 #ifdef HAVE_CONFIG_H
  42 #include "config.h"
  43 #endif
  44
  45 #include <sys/cdefs.h>
  46 #ifndef lint
  47 #if 0
  48 static const char rcsid[] _U_ =
  49      "@(#) Header: /tcpdump/master/tcpdump/print-telnet.c,v 1.24 2003/12/29 11:05:10 hannes Exp";
  50 #else
  51 __RCSID("$NetBSD: print-telnet.c,v 1.5 2007/07/24 11:53:48 drochner Exp $");
  52 #endif
  53 #endif
  54
  55 #include <tcpdump-stdinc.h>
  56
  57 #include <stdio.h>
  58 #include <stdlib.h>
  59 #include <string.h>
  60
  61 #include "interface.h"
  62 #include "addrtoname.h"
  63
  64 #define TELCMDS
  65 #define TELOPTS
  66 #include "telnet.h"
  67
  68 /* normal */
  69 static const char *cmds[] = {
  70         "IS", "SEND", "INFO",
  71 };
  72
  73 /* 37: Authentication */
  74 static const char *authcmd[] = {
  75         "IS", "SEND", "REPLY", "NAME",
  76 };
  77 static const char *authtype[] = {
  78         "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK",
  79         "SRP", "RSA", "SSL", NULL, NULL,
  80         "LOKI", "SSA", "KEA_SJ", "KEA_SJ_INTEG", "DSS",
  81         "NTLM",
  82 };
  83
  84 /* 38: Encryption */
  85 static const char *enccmd[] = {
  86         "IS", "SUPPORT", "REPLY", "START", "END",
  87         "REQUEST-START", "REQUEST-END", "END_KEYID", "DEC_KEYID",
  88 };
  89 static const char *enctype[] = {
  90         "NULL", "DES_CFB64", "DES_OFB64", "DES3_CFB64", "DES3_OFB64",
  91         NULL, "CAST5_40_CFB64", "CAST5_40_OFB64", "CAST128_CFB64", "CAST128_OFB64",
  92 };
  93
  94 #define STR_OR_ID(x, tab) \
  95         (((x) < sizeof(tab)/sizeof(tab[0]) && tab[(x)]) ? tab[(x)] : numstr(x))
  96
  97 static char *
  98 numstr(int x)
  99 {
 100         static char buf[20];
 101
 102         snprintf(buf, sizeof(buf), "%#x", x);
 103         return buf;
 104 }
 105
 106 /* sp points to IAC byte */
 107 static int
 108 telnet_parse(const u_char *sp, u_int length, int print)
 109 {
 110         int i, x;
 111         u_int c;
 112         const u_char *osp, *p;
 113 #define FETCH(c, sp, length) \
 114         do { \
 115                 if (length < 1) \
 116                         goto pktend; \
 117                 TCHECK(*sp); \
 118                 c = *sp++; \
 119                 length--; \
 120         } while (0)
 121
 122         osp = sp;
 123
 124         FETCH(c, sp, length);
 125         if (c != IAC)
 126                 goto pktend;
 127         FETCH(c, sp, length);
 128         if (c == IAC) {         /* <IAC><IAC>! */
 129                 if (print)
 130                         printf("IAC IAC");
 131                 goto done;
 132         }
 133
 134         i = c - TELCMD_FIRST;
 135         if (i < 0 || i > IAC - TELCMD_FIRST)
 136                 goto pktend;
 137
 138         switch (c) {
 139         case DONT:
 140         case DO:
 141         case WONT:
 142         case WILL:
 143         case SB:
 144                 /* DONT/DO/WONT/WILL x */
 145                 FETCH(x, sp, length);
 146                 if (x >= 0 && x < NTELOPTS) {
 147                         if (print)
 148                                 (void)printf("%s %s", telcmds[i], telopts[x]);
 149                 } else {
 150                         if (print)
 151                                 (void)printf("%s %#x", telcmds[i], x);
 152                 }
 153                 if (c != SB)
 154                         break;
 155                 /* IAC SB .... IAC SE */
 156                 p = sp;
 157                 while (length > (u_int)(p + 1 - sp)) {
 158                         if (p[0] == IAC && p[1] == SE)
 159                                 break;
 160                         p++;
 161                 }
 162                 if (*p != IAC)
 163                         goto pktend;
 164
 165                 switch (x) {
 166                 case TELOPT_AUTHENTICATION:
 167                         if (p <= sp)
 168                                 break;
 169                         FETCH(c, sp, length);
 170                         if (print)
 171                                 (void)printf(" %s", STR_OR_ID(c, authcmd));
 172                         if (p <= sp)
 173                                 break;
 174                         FETCH(c, sp, length);
 175                         if (print)
 176                                 (void)printf(" %s", STR_OR_ID(c, authtype));
 177                         break;
 178                 case TELOPT_ENCRYPT:
 179                         if (p <= sp)
 180                                 break;
 181                         FETCH(c, sp, length);
 182                         if (print)
 183                                 (void)printf(" %s", STR_OR_ID(c, enccmd));
 184                         if (p <= sp)
 185                                 break;
 186                         FETCH(c, sp, length);
 187                         if (print)
 188                                 (void)printf(" %s", STR_OR_ID(c, enctype));
 189                         break;
 190                 default:
 191                         if (p <= sp)
 192                                 break;
 193                         FETCH(c, sp, length);
 194                         if (print)
 195                                 (void)printf(" %s", STR_OR_ID(c, cmds));
 196                         break;
 197                 }
 198                 while (p > sp) {
 199                         FETCH(x, sp, length);
 200                         if (print)
 201                                 (void)printf(" %#x", x);
 202                 }
 203                 /* terminating IAC SE */
 204                 if (print)
 205                         (void)printf(" SE");
 206                 sp += 2;
 207                 length -= 2;
 208                 break;
 209         default:
 210                 if (print)
 211                         (void)printf("%s", telcmds[i]);
 212                 goto done;
 213         }
 214
 215 done:
 216         return sp - osp;
 217
 218 trunc:
 219         (void)printf("[|telnet]");
 220 pktend:
 221         return -1;
 222 #undef FETCH
 223 }
 224
 225 void
 226 telnet_print(const u_char *sp, u_int length)
 227 {
 228         int first = 1;
 229         const u_char *osp;
 230         int l;
 231
 232         osp = sp;
 233
 234         while (length > 0 && *sp == IAC) {
 235                 l = telnet_parse(sp, length, 0);
 236                 if (l < 0)
 237                         break;
 238
 239                 /*
 240                  * now print it
 241                  */
 242                 if (Xflag && 2 < vflag) {
 243                         if (first)
 244                                 printf("\nTelnet:");
 245                         hex_print_with_offset("\n", sp, l, sp - osp);
 246                         if (l > 8)
 247                                 printf("\n\t\t\t\t");
 248                         else
 249                                 printf("%*s\t", (8 - l) * 3, "");
 250                 } else
 251                         printf("%s", (first) ? " [telnet " : ", ");
 252
 253                 (void)telnet_parse(sp, length, 1);
 254                 first = 0;
 255
 256                 sp += l;
 257                 length -= l;
 258         }
 259         if (!first) {
 260                 if (Xflag && 2 < vflag)
 261                         printf("\n");
 262                 else
 263                         printf("]");
 264         }
 265 }