telnet.c

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

static
void rec_do(struct connectdata *conn, int option)
{
  struct TELNET *tn = (struct TELNET *)conn->proto.telnet;
  switch(tn->us[option])
  {
    case CURL_NO:
      if(tn->us_preferred[option] == CURL_YES)
      {
        tn->us[option] = CURL_YES;
        send_negotiation(conn, CURL_WILL, option);
      }
      else
      {
        send_negotiation(conn, CURL_WONT, option);
      }
      break;
	 
    case CURL_YES:
      /* Already enabled */
      break;
	 
    case CURL_WANTNO:
      switch(tn->usq[option])
      {
        case CURL_EMPTY:
          /* Error: DONT answered by WILL */
          tn->us[option] = CURL_NO;
          break;
        case CURL_OPPOSITE:
          /* Error: DONT answered by WILL */
          tn->us[option] = CURL_YES;
          tn->usq[option] = CURL_EMPTY;
          break;
      }
      break;
	 
    case CURL_WANTYES:
      switch(tn->usq[option])
      {
        case CURL_EMPTY:
          tn->us[option] = CURL_YES;
          break;
        case CURL_OPPOSITE:
          tn->us[option] = CURL_WANTNO;
          tn->himq[option] = CURL_EMPTY;
          send_negotiation(conn, CURL_WONT, option);
          break;
      }
      break;
  }
}

static   
void rec_dont(struct connectdata *conn, int option)
{
  struct TELNET *tn = (struct TELNET *)conn->proto.telnet;
  switch(tn->us[option])
  {
    case CURL_NO:
      /* Already disabled */
      break;
	 
    case CURL_YES:
      tn->us[option] = CURL_NO;
      send_negotiation(conn, CURL_WONT, option);
      break;
	 
    case CURL_WANTNO:
      switch(tn->usq[option])
      {
        case CURL_EMPTY:
          tn->us[option] = CURL_NO;
          break;
	 
        case CURL_OPPOSITE:
          tn->us[option] = CURL_WANTYES;
          tn->usq[option] = CURL_EMPTY;
          send_negotiation(conn, CURL_WILL, option);
          break;
      }
      break;
	 
    case CURL_WANTYES:
      switch(tn->usq[option])
      {
        case CURL_EMPTY:
          tn->us[option] = CURL_NO;
          break;
        case CURL_OPPOSITE:
          tn->us[option] = CURL_NO;
          tn->usq[option] = CURL_EMPTY;
          break;
      }
      break;
  }
}


static void printsub(struct SessionHandle *data,
		     int direction,		/* '<' or '>' */
		     unsigned char *pointer,	/* where suboption data is */
		     int length)		/* length of suboption data */
{
  int i = 0;

  if (data->set.verbose)
  {
    if (direction)
    {
      Curl_infof(data, "%s IAC SB ", (direction == '<')? "RCVD":"SENT");
      if (length >= 3)
      {
        int j;

        i = pointer[length-2];
        j = pointer[length-1];

        if (i != CURL_IAC || j != CURL_SE)
        {
          Curl_infof(data, "(terminated by ");
          if (CURL_TELOPT_OK(i))
            Curl_infof(data, "%s ", CURL_TELOPT(i));
          else if (CURL_TELCMD_OK(i))
            Curl_infof(data, "%s ", CURL_TELCMD(i));
          else
            Curl_infof(data, "%d ", i);
          if (CURL_TELOPT_OK(j))
            Curl_infof(data, "%s", CURL_TELOPT(j));
          else if (CURL_TELCMD_OK(j))
            Curl_infof(data, "%s", CURL_TELCMD(j));
          else
            Curl_infof(data, "%d", j);
          Curl_infof(data, ", not IAC SE!) ");
        }
      }
      length -= 2;
    }
    if (length < 1)
    {
      Curl_infof(data, "(Empty suboption?)");
      return;
    }

    if (CURL_TELOPT_OK(pointer[0])) {
      switch(pointer[0]) {
        case CURL_TELOPT_TTYPE:
        case CURL_TELOPT_XDISPLOC:
        case CURL_TELOPT_NEW_ENVIRON:
          Curl_infof(data, "%s", CURL_TELOPT(pointer[0]));
          break;
        default:
          Curl_infof(data, "%s (unsupported)", CURL_TELOPT(pointer[0]));
          break;
      }
    }
    else
      Curl_infof(data, "%d (unknown)", pointer[i]);

    switch(pointer[1]) {
      case CURL_TELQUAL_IS:
        Curl_infof(data, " IS");
        break;
      case CURL_TELQUAL_SEND:
        Curl_infof(data, " SEND");
        break;
      case CURL_TELQUAL_INFO:
        Curl_infof(data, " INFO/REPLY");
        break;
      case CURL_TELQUAL_NAME:
        Curl_infof(data, " NAME");
        break;
    }
      
    switch(pointer[0]) {
      case CURL_TELOPT_TTYPE:
      case CURL_TELOPT_XDISPLOC:
        pointer[length] = 0;
        Curl_infof(data, " \"%s\"", &pointer[2]);
        break;
      case CURL_TELOPT_NEW_ENVIRON:
        if(pointer[1] == CURL_TELQUAL_IS) {
          Curl_infof(data, " ");
          for(i = 3;i < length;i++) {
            switch(pointer[i]) {
              case CURL_NEW_ENV_VAR:
                Curl_infof(data, ", ");
                break;
              case CURL_NEW_ENV_VALUE:
                Curl_infof(data, " = ");
                break;
              default:
                Curl_infof(data, "%c", pointer[i]);
                break;
            }
          }
        }
        break;
      default:
        for (i = 2; i < length; i++)
          Curl_infof(data, " %.2x", pointer[i]);
        break;
    }
      
    if (direction)
    {
      Curl_infof(data, "\n");
    }
  }
}

static int check_telnet_options(struct connectdata *conn)
{
  struct curl_slist *head;
  char option_keyword[128];
  char option_arg[256];
  char *buf;
  struct SessionHandle *data = conn->data;
  struct TELNET *tn = (struct TELNET *)conn->proto.telnet;

  /* Add the user name as an environment variable if it
     was given on the command line */
  if(conn->bits.user_passwd)
  {
    snprintf(option_arg, sizeof(option_arg), "USER,%s", conn->user);
    tn->telnet_vars = curl_slist_append(tn->telnet_vars, option_arg);

    tn->us_preferred[CURL_TELOPT_NEW_ENVIRON] = CURL_YES;
  }

  for(head = data->set.telnet_options; head; head=head->next) {
    if(sscanf(head->data, "%127[^= ]%*[ =]%255s",
              option_keyword, option_arg) == 2) {

      /* Terminal type */
      if(curl_strequal(option_keyword, "TTYPE")) {
        strncpy(tn->subopt_ttype, option_arg, 31);
        tn->subopt_ttype[31] = 0; /* String termination */
        tn->us_preferred[CURL_TELOPT_TTYPE] = CURL_YES;
        continue;
      }

      /* Display variable */
      if(curl_strequal(option_keyword, "XDISPLOC")) {
        strncpy(tn->subopt_xdisploc, option_arg, 127);
        tn->subopt_xdisploc[127] = 0; /* String termination */
        tn->us_preferred[CURL_TELOPT_XDISPLOC] = CURL_YES;
        continue;
      }

      /* Environment variable */
      if(curl_strequal(option_keyword, "NEW_ENV")) {
        buf = strdup(option_arg);
        if(!buf)
          return CURLE_OUT_OF_MEMORY;
        tn->telnet_vars = curl_slist_append(tn->telnet_vars, buf);
        tn->us_preferred[CURL_TELOPT_NEW_ENVIRON] = CURL_YES;
        continue;
      }

      failf(data, "Unknown telnet option %s", head->data);
      return CURLE_UNKNOWN_TELNET_OPTION;
    } else {
      failf(data, "Syntax error in telnet option: %s", head->data);
      return CURLE_TELNET_OPTION_SYNTAX;
    }
  }

  return CURLE_OK;
}

/*
 * suboption()
 *
 * Look at the sub-option buffer, and try to be helpful to the other
 * side.
 */

static void suboption(struct connectdata *conn)
{
  struct curl_slist *v;
  unsigned char subchar;
  unsigned char temp[2048];
  int len;
  int tmplen;