telnet.c

/***************************************************************************
 *                                  _   _ ____  _     
 *  Project                     ___| | | |  _ \| |    
 *                             / __| | | | |_) | |    
 *                            | (__| |_| |  _ <| |___ 
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2002, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at http://curl.haxx.se/docs/copyright.html.
 * 
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * $Id$
 ***************************************************************************/

#include "setup.h"

#ifndef CURL_DISABLE_TELNET
/* -- WIN32 approved -- */
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>

#include <errno.h>

#if defined(WIN32) && !defined(__GNUC__) || defined(__MINGW32__)
#include <winsock2.h>
#include <time.h>
#include <io.h>
#else
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <netinet/in.h>
#include <sys/time.h>
#include <sys/resource.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <netdb.h>
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
#include <sys/ioctl.h>
#include <signal.h>

#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif

#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif


#endif

#include "urldata.h"
#include <curl/curl.h>
#include "transfer.h"
#include "sendf.h"

#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>

#define  TELOPTS
#define  TELCMDS

#include "arpa_telnet.h"

/* The last #include file should be: */
#ifdef MALLOCDEBUG
#include "memdebug.h"
#endif

#define SUBBUFSIZE 512

#define  SB_CLEAR(x)  x->subpointer = x->subbuffer;
#define  SB_TERM(x)   { x->subend = x->subpointer; SB_CLEAR(x); }
#define  SB_ACCUM(x,c) if (x->subpointer < (x->subbuffer+sizeof x->subbuffer)) { \
            *x->subpointer++ = (c); \
         }

#define  SB_GET(x) ((*x->subpointer++)&0xff)
#define  SB_PEEK(x)   ((*x->subpointer)&0xff)
#define  SB_EOF(x) (x->subpointer >= x->subend)
#define  SB_LEN(x) (x->subend - x->subpointer)

static
void telrcv(struct connectdata *,
	    unsigned char *inbuf,	/* Data received from socket */
	    int count);			/* Number of bytes received */

static void printoption(struct SessionHandle *data,
			const char *direction,
			int cmd, int option);

static void negotiate(struct connectdata *);
static void send_negotiation(struct connectdata *, int cmd, int option);
static void set_local_option(struct connectdata *, int cmd, int option);
static void set_remote_option(struct connectdata *, int cmd, int option);

static void printsub(struct SessionHandle *data,
		     int direction, unsigned char *pointer, int length);
static void suboption(struct connectdata *);

/* For negotiation compliant to RFC 1143 */
#define NO	0
#define YES 	1
#define WANTYES	2
#define WANTNO	3

#define EMPTY	 0
#define OPPOSITE 1

/*
 * Telnet receiver states for fsm
 */
typedef enum
{
   TS_DATA = 0,
   TS_IAC,
   TS_WILL,
   TS_WONT,
   TS_DO,
   TS_DONT,
   TS_CR,
   TS_SB,   /* sub-option collection */
   TS_SE   /* looking for sub-option end */
} TelnetReceive;

struct TELNET {
  int please_negotiate;
  int already_negotiated;
  int us[256]; 
  int usq[256]; 
  int us_preferred[256]; 
  int him[256]; 
  int himq[256]; 
  int him_preferred[256]; 
  char subopt_ttype[32];             /* Set with suboption TTYPE */
  char subopt_xdisploc[128];          /* Set with suboption XDISPLOC */
  struct curl_slist *telnet_vars; /* Environment variables */

  /* suboptions */
  char subbuffer[SUBBUFSIZE];
  char *subpointer, *subend;      /* buffer for sub-options */
  
  TelnetReceive telrcv_state;
};

static
CURLcode init_telnet(struct connectdata *conn)
{
  struct TELNET *tn;

  tn = (struct TELNET *)malloc(sizeof(struct TELNET));
  if(!tn)
    return CURLE_OUT_OF_MEMORY;
  
  conn->proto.telnet = (void *)tn; /* make us known */

  memset(tn, 0, sizeof(struct TELNET));

  tn->telrcv_state = TS_DATA;

  /* Init suboptions */
  SB_CLEAR(tn);

  /* Set all options to NO */
#if 0
  /* NO is zero => default fill pattern */
  memset(tn->us, NO, 256);
  memset(tn->usq, NO, 256);
  memset(tn->us_preferred, NO, 256);
  memset(tn->him, NO, 256);
  memset(tn->himq, NO, 256);
  memset(tn->him_preferred, NO, 256);
#endif
  /* Set the options we want by default */
  tn->us_preferred[TELOPT_BINARY] = YES;
  tn->us_preferred[TELOPT_SGA] = YES;
  tn->him_preferred[TELOPT_BINARY] = YES;
  tn->him_preferred[TELOPT_SGA] = YES;