telnet.c

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/***************************************************************************
 *                                  _   _ ____  _     
 *  Project                     ___| | | |  _ \| |    
 *                             / __| | | | |_) | |    
 *                            | (__| |_| |  _ <| |___ 
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2003, Daniel Stenberg, <[e-mail]>, 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: telnet.c,v 1.47 2003/10/19 05:42:49 bagder Exp $
 ***************************************************************************/

#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)
#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>
#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 CURLDEBUG
#include "memdebug.h"
#endif

#define SUBBUFSIZE 512

#define CURL_SB_CLEAR(x)  x->subpointer = x->subbuffer;
#define CURL_SB_TERM(x)   { x->subend = x->subpointer; CURL_SB_CLEAR(x); }
#define CURL_SB_ACCUM(x,c) \
  if (x->subpointer < (x->subbuffer+sizeof x->subbuffer)) { \
    *x->subpointer++ = (c); \
  }

#define  CURL_SB_GET(x) ((*x->subpointer++)&0xff)
#define  CURL_SB_PEEK(x)   ((*x->subpointer)&0xff)
#define  CURL_SB_EOF(x) (x->subpointer >= x->subend)
#define  CURL_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 CURL_NO	         0
#define CURL_YES 	 1
#define CURL_WANTYES	 2
#define CURL_WANTNO	 3

#define CURL_EMPTY	 0
#define CURL_OPPOSITE    1

/*
 * Telnet receiver states for fsm
 */
typedef enum
{
   CURL_TS_DATA = 0,
   CURL_TS_IAC,
   CURL_TS_WILL,
   CURL_TS_WONT,
   CURL_TS_DO,
   CURL_TS_DONT,
   CURL_TS_CR,
   CURL_TS_SB,   /* sub-option collection */
   CURL_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 = CURL_TS_DATA;

  /* Init suboptions */
  CURL_SB_CLEAR(tn);

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

  return CURLE_OK;
}

static void negotiate(struct connectdata *conn)
{
  int i;
  struct TELNET *tn = (struct TELNET *)conn->proto.telnet;
   
  for(i = 0;i < CURL_NTELOPTS;i++)
  {
    if(tn->us_preferred[i] == CURL_YES)
      set_local_option(conn, i, CURL_YES);
      
    if(tn->him_preferred[i] == CURL_YES)
      set_remote_option(conn, i, CURL_YES);
  }
}

static void printoption(struct SessionHandle *data,
			const char *direction, int cmd, int option)
{
  const char *fmt;
  const char *opt;
   
  if (data->set.verbose)
  {
    if (cmd == CURL_IAC)
    {
      if (CURL_TELCMD_OK(option))
        Curl_infof(data, "%s IAC %s\n", direction, CURL_TELCMD(option));
      else
        Curl_infof(data, "%s IAC %d\n", direction, option);
    }
    else
    {
      fmt = (cmd == CURL_WILL) ? "WILL" : (cmd == CURL_WONT) ? "WONT" :
        (cmd == CURL_DO) ? "DO" : (cmd == CURL_DONT) ? "DONT" : 0;
      if (fmt)
      {
        if (CURL_TELOPT_OK(option))
          opt = CURL_TELOPT(option);
        else if (option == CURL_TELOPT_EXOPL)
          opt = "EXOPL";
        else
          opt = NULL;

        if(opt)
          Curl_infof(data, "%s %s %s\n", direction, fmt, opt);
        else
          Curl_infof(data, "%s %s %d\n", direction, fmt, option);
      }
      else
        Curl_infof(data, "%s %d %d\n", direction, cmd, option);
    }
  }
}

static void send_negotiation(struct connectdata *conn, int cmd, int option)
{
   unsigned char buf[3];

   buf[0] = CURL_IAC;
   buf[1] = cmd;
   buf[2] = option;
   
   (void)swrite(conn->firstsocket, buf, 3);
   
   printoption(conn->data, "SENT", cmd, option);
}

static
void set_remote_option(struct connectdata *conn, int option, int newstate)
{
  struct TELNET *tn = (struct TELNET *)conn->proto.telnet;
  if(newstate == CURL_YES)
  {
    switch(tn->him[option])
    {
      case CURL_NO:
        tn->him[option] = CURL_WANTYES;
        send_negotiation(conn, CURL_DO, option);
        break;
	 
      case CURL_YES:
        /* Already enabled */
        break;
	 
      case CURL_WANTNO:
        switch(tn->himq[option])
        {
          case CURL_EMPTY:
            /* Already negotiating for CURL_YES, queue the request */
            tn->himq[option] = CURL_OPPOSITE;
            break;
          case CURL_OPPOSITE:
            /* Error: already queued an enable request */
            break;
        }
        break;
	 
      case CURL_WANTYES:
        switch(tn->himq[option])
        {
          case CURL_EMPTY:
            /* Error: already negotiating for enable */
            break;
          case CURL_OPPOSITE:
            tn->himq[option] = CURL_EMPTY;
            break;
        }
        break;
    }
  }
  else /* NO */
  {
    switch(tn->him[option])
    {
      case CURL_NO:
        /* Already disabled */
        break;
	 
      case CURL_YES:
        tn->him[option] = CURL_WANTNO;
        send_negotiation(conn, CURL_DONT, option);
        break;
	 
      case CURL_WANTNO:
        switch(tn->himq[option])
        {
          case CURL_EMPTY:
            /* Already negotiating for NO */
            break;
          case CURL_OPPOSITE:
            tn->himq[option] = CURL_EMPTY;
            break;
        }
        break;
	 
      case CURL_WANTYES:
        switch(tn->himq[option])
        {
          case CURL_EMPTY:
            tn->himq[option] = CURL_OPPOSITE;
            break;
          case CURL_OPPOSITE:
            break;
        }
        break;
    }
  }
}

static
void rec_will(struct connectdata *conn, int option)
{
  struct TELNET *tn = (struct TELNET *)conn->proto.telnet;
  switch(tn->him[option])
  {
    case CURL_NO:
      if(tn->him_preferred[option] == CURL_YES)
      {
        tn->him[option] = CURL_YES;
        send_negotiation(conn, CURL_DO, option);
      }
      else
      {
        send_negotiation(conn, CURL_DONT, option);
      }
      break;
	 
    case CURL_YES:
      /* Already enabled */
      break;
	 
    case CURL_WANTNO:
      switch(tn->himq[option])
      {
        case CURL_EMPTY:
          /* Error: DONT answered by WILL */
          tn->him[option] = CURL_NO;
          break;
        case CURL_OPPOSITE:
          /* Error: DONT answered by WILL */
          tn->him[option] = CURL_YES;
          tn->himq[option] = CURL_EMPTY;
          break;
      }
      break;
	 
    case CURL_WANTYES:
      switch(tn->himq[option])
      {
        case CURL_EMPTY:
          tn->him[option] = CURL_YES;
          break;
        case CURL_OPPOSITE:
          tn->him[option] = CURL_WANTNO;
          tn->himq[option] = CURL_EMPTY;
          send_negotiation(conn, CURL_DONT, option);
          break;
      }
      break;
  }
}
   
static
void rec_wont(struct connectdata *conn, int option)
{
  struct TELNET *tn = (struct TELNET *)conn->proto.telnet;