Logo Search packages:      
Sourcecode: tcpdump version File versions

print-telnet.c

/*    $NetBSD: print-telnet.c,v 1.2 1999/10/11 12:40:12 sjg Exp $       */

/*-
 * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Simon J. Gerraty.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
/*
 *      @(#)Copyright (c) 1994, Simon J. Gerraty.
 *
 *      This is free software.  It comes with NO WARRANTY.
 *      Permission to use, modify and distribute this source code
 *      is granted subject to the following conditions.
 *      1/ that the above copyright notice and this notice
 *      are preserved in all copies.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifndef lint
static const char rcsid[] _U_ =
     "@(#) $Header: /tcpdump/master/tcpdump/print-telnet.c,v 1.21.2.3 2003/12/29 22:42:23 hannes Exp $";
#endif

#include <tcpdump-stdinc.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "interface.h"
#include "addrtoname.h"

#define TELCMDS
#define TELOPTS
#include "telnet.h"

/* normal */
static const char *cmds[] = {
      "IS", "SEND", "INFO",
};

/* 37: Authentication */
static const char *authcmd[] = {
      "IS", "SEND", "REPLY", "NAME",
};
static const char *authtype[] = {
      "NULL", "KERBEROS_V4", "KERBEROS_V5", "SPX", "MINK",
      "SRP", "RSA", "SSL", NULL, NULL,
      "LOKI", "SSA", "KEA_SJ", "KEA_SJ_INTEG", "DSS",
      "NTLM",
};

/* 38: Encryption */
static const char *enccmd[] = {
      "IS", "SUPPORT", "REPLY", "START", "END",
      "REQUEST-START", "REQUEST-END", "END_KEYID", "DEC_KEYID",
};
static const char *enctype[] = {
      "NULL", "DES_CFB64", "DES_OFB64", "DES3_CFB64", "DES3_OFB64",
      NULL, "CAST5_40_CFB64", "CAST5_40_OFB64", "CAST128_CFB64", "CAST128_OFB64",
};

#define STR_OR_ID(x, tab) \
      (((x) < sizeof(tab)/sizeof(tab[0]) && tab[(x)]) ? tab[(x)] : numstr(x))

static char *
numstr(int x)
{
      static char buf[20];

      snprintf(buf, sizeof(buf), "%#x", x);
      return buf;
}

/* sp points to IAC byte */
static int
telnet_parse(const u_char *sp, u_int length, int print)
{
      int i, x;
      u_int c;
      const u_char *osp, *p;
#define FETCH(c, sp, length) \
      do { \
            if (length < 1) \
                  goto pktend; \
            TCHECK(*sp); \
            c = *sp++; \
            length--; \
      } while (0)

      osp = sp;

      FETCH(c, sp, length);
      if (c != IAC)
            goto pktend;
      FETCH(c, sp, length);
      if (c == IAC) {         /* <IAC><IAC>! */
            if (print)
                  printf("IAC IAC");
            goto done;
      }

      i = c - TELCMD_FIRST;
      if (i < 0 || i > IAC - TELCMD_FIRST)
            goto pktend;

      switch (c) {
      case DONT:
      case DO:
      case WONT:
      case WILL:
      case SB:
            /* DONT/DO/WONT/WILL x */
            FETCH(x, sp, length);
            if (x >= 0 && x < NTELOPTS) {
                  if (print)
                        (void)printf("%s %s", telcmds[i], telopts[x]);
            } else {
                  if (print)
                        (void)printf("%s %#x", telcmds[i], x);
            }
            if (c != SB)
                  break;
            /* IAC SB .... IAC SE */
            p = sp;
            while (length > (u_int)(p + 1 - sp)) {
                  if (p[0] == IAC && p[1] == SE)
                        break;
                  p++;
            }
            if (*p != IAC)
                  goto pktend;

            switch (x) {
            case TELOPT_AUTHENTICATION:
                  if (p <= sp)
                        break;
                  FETCH(c, sp, length);
                  if (print)
                        (void)printf(" %s", STR_OR_ID(c, authcmd));
                  if (p <= sp)
                        break;
                  FETCH(c, sp, length);
                  if (print)
                        (void)printf(" %s", STR_OR_ID(c, authtype));
                  break;
            case TELOPT_ENCRYPT:
                  if (p <= sp)
                        break;
                  FETCH(c, sp, length);
                  if (print)
                        (void)printf(" %s", STR_OR_ID(c, enccmd));
                  if (p <= sp)
                        break;
                  FETCH(c, sp, length);
                  if (print)
                        (void)printf(" %s", STR_OR_ID(c, enctype));
                  break;
            default:
                  if (p <= sp)
                        break;
                  FETCH(c, sp, length);
                  if (print)
                        (void)printf(" %s", STR_OR_ID(c, cmds));
                  break;
            }
            while (p > sp) {
                  FETCH(x, sp, length);
                  if (print)
                        (void)printf(" %#x", x);
            }
            /* terminating IAC SE */
            if (print)
                  (void)printf(" SE");
            sp += 2;
            length -= 2;
            break;
      default:
            if (print)
                  (void)printf("%s", telcmds[i]);
            goto done;
      }

done:
      return sp - osp;

trunc:
      (void)printf("[|telnet]");
pktend:
      return -1;
#undef FETCH
}

void
telnet_print(const u_char *sp, u_int length)
{
      int first = 1;
      const u_char *osp;
      int l;

      osp = sp;

      while (length > 0 && *sp == IAC) {
            l = telnet_parse(sp, length, 0);
            if (l < 0)
                  break;

            /*
             * now print it
             */
            if (Xflag && 2 < vflag) {
                  if (first)
                        printf("\nTelnet:");
                  hex_print_with_offset("\n", sp, l, sp - osp);
                  if (l > 8)
                        printf("\n\t\t\t\t");
                  else
                        printf("%*s\t", (8 - l) * 3, "");
            } else
                  printf("%s", (first) ? " [telnet " : ", ");

            (void)telnet_parse(sp, length, 1);
            first = 0;

            sp += l;
            length -= l;
      }
      if (!first) {
            if (Xflag && 2 < vflag)
                  printf("\n");
            else
                  printf("]");
      }
}

Generated by  Doxygen 1.6.0   Back to index