function exec($command, $callback = null)
{
$this->curTimeout = $this->timeout;
$this->is_timeout = false;
$this->stdErrorLog = '';
if (!($this->bitmap & self::MASK_LOGIN)) {
return false;
}
// RFC4254 defines the (client) window size as "bytes the other party can send before it must wait for the window to
// be adjusted". 0x7FFFFFFF is, at 2GB, the max size. technically, it should probably be decremented, but,
// honestly, if you're transferring more than 2GB, you probably shouldn't be using phpseclib, anyway.
// see http://tools.ietf.org/html/rfc4254#section-5.2 for more info
$this->window_size_server_to_client[self::CHANNEL_EXEC] = $this->window_size;
// 0x8000 is the maximum max packet size, per http://tools.ietf.org/html/rfc4253#section-6.1, although since PuTTy
// uses 0x4000, that's what will be used here, as well.
$packet_size = 0x4000;
$packet = pack('CNa*N3', NET_SSH2_MSG_CHANNEL_OPEN, strlen('session'), 'session', self::CHANNEL_EXEC, $this->window_size_server_to_client[self::CHANNEL_EXEC], $packet_size);
if (!$this->_send_binary_packet($packet)) {
return false;
}
$this->channel_status[self::CHANNEL_EXEC] = NET_SSH2_MSG_CHANNEL_OPEN;
$response = $this->_get_channel_packet(self::CHANNEL_EXEC);
if ($response === false) {
return false;
}
if ($this->request_pty === true) {
$terminal_modes = pack('C', NET_SSH2_TTY_OP_END);
$packet = pack('CNNa*CNa*N5a*', NET_SSH2_MSG_CHANNEL_REQUEST, $this->server_channels[self::CHANNEL_EXEC], strlen('pty-req'), 'pty-req', 1, strlen('vt100'), 'vt100', $this->windowColumns, $this->windowRows, 0, 0, strlen($terminal_modes), $terminal_modes);
if (!$this->_send_binary_packet($packet)) {
return false;
}
$response = $this->_get_binary_packet();
if ($response === false) {
throw new \RuntimeException('Connection closed by server');
}
if (!strlen($response)) {
return false;
}
list(, $type) = unpack('C', Strings::shift($response, 1));
switch ($type) {
case NET_SSH2_MSG_CHANNEL_SUCCESS:
break;
case NET_SSH2_MSG_CHANNEL_FAILURE:
default:
$this->_disconnect(NET_SSH2_DISCONNECT_BY_APPLICATION);
throw new \RuntimeException('Unable to request pseudo-terminal');
}
$this->in_request_pty_exec = true;
}
// sending a pty-req SSH_MSG_CHANNEL_REQUEST message is unnecessary and, in fact, in most cases, slows things
// down. the one place where it might be desirable is if you're doing something like \phpseclib\Net\SSH2::exec('ping localhost &').
// with a pty-req SSH_MSG_CHANNEL_REQUEST, exec() will return immediately and the ping process will then
// then immediately terminate. without such a request exec() will loop indefinitely. the ping process won't end but
// neither will your script.
// although, in theory, the size of SSH_MSG_CHANNEL_REQUEST could exceed the maximum packet size established by
// SSH_MSG_CHANNEL_OPEN_CONFIRMATION, RFC4254#section-5.1 states that the "maximum packet size" refers to the
// "maximum size of an individual data packet". ie. SSH_MSG_CHANNEL_DATA. RFC4254#section-5.2 corroborates.
$packet = pack('CNNa*CNa*', NET_SSH2_MSG_CHANNEL_REQUEST, $this->server_channels[self::CHANNEL_EXEC], strlen('exec'), 'exec', 1, strlen($command), $command);
if (!$this->_send_binary_packet($packet)) {
return false;
}
$this->channel_status[self::CHANNEL_EXEC] = NET_SSH2_MSG_CHANNEL_REQUEST;
$response = $this->_get_channel_packet(self::CHANNEL_EXEC);
if ($response === false) {
return false;
}
$this->channel_status[self::CHANNEL_EXEC] = NET_SSH2_MSG_CHANNEL_DATA;
if ($callback === false || $this->in_request_pty_exec) {
return true;
}
$output = '';
while (true) {
$temp = $this->_get_channel_packet(self::CHANNEL_EXEC);
switch (true) {
case $temp === true:
return is_callable($callback) ? true : $output;
case $temp === false:
return false;
default:
if (is_callable($callback)) {
if (call_user_func($callback, $temp) === true) {
$this->_close_channel(self::CHANNEL_EXEC);
return true;
}
} else {
$output .= $temp;
}
}
}
}
