I am executing commands(fputs) on socket/telnet console and getting output/result(fread) by below code and it's working perfectly fine.
//open socket let's say ip = 192.168.10.5 and port = 21
$this->socketResource = fsockopen($this->nodeIp,$this->portNumber);
//execute some commands, for example "ipconfig"
fputs($this->socketResource,$command);
//get output string
$output = fread($this->socketResource,30000);
Now my requirement is to get all console/socket output without executing any command by fputs. For example, Cisco routers give continuous debug messages/prints on the telnet console/socket without executing any command by fputs.
How can i capture(fread) any telnet session output continuously for some duration without executing any command(fputs)?
If i capture in discrete fashion like every x seconds, i will definitely miss some console output.
For this, I would would switch over to the stream_* family. There is a huge improvement when trying to accomplish the above with performance and extending.
$stream = stream_socket_client("tcp://10.1.1.1:23", $errno, $errstr, 30);
if (!$stream ) {
echo "$errstr ($errno)<br />\n";
} else {
fwrite($stream , "sh run" . PHP_EOL);
// Set Blocking Mode - Wait For A Response On The Stream
stream_set_blocking( $stream , true );
while( true ){
// This is your response
echo stream_get_contents( $stream );
}
}
You will need to add something above to break the while(true) loop, or the script will run forever, but this is an approach I use to do something similar.
Related
I'm not an expert with PHP. I have a function which uses EXEC to run WINRS whcih then runs commands on remote servers. The problem is this function is placed into a loop which calls getservicestatus function dozens of times. Sometimes the WINRS command can get stuck or take longer than expected causing the PHP script to time out and throw a 500 error.
Temporarily I've lowered the set timeout value in PHP and created a custom 500 page in IIS and if the referring page is equal to the script name then reload the page (else, throw an error). But this is messy. And obviously it doesn't apply to each time the function is called as it's global. So it only avoids the page stopping at the HTTP 500 error.
What I'd really like to do is set a timeout of 5 seconds on the function itself. I've been searching quite a bit and have been unable to find an answer, even on stackoverflow. Yes, there are similar questions but I have not been able to find any that relate to my function. Perhaps there's a way to do this when executing the command such as an alternative to exec()? I don't know. Ideally I'd like the function to timeout after 5 seconds and return $servicestate as 0.
Code is commented to explain my spaghetti mess. And I'm sorry you have to see it...
function getservicestatus($servername, $servicename, $username, $password)
{
//define start so that if an invalid result is reached the function can be restarted using goto.
start:
//Define command to use to get service status.
$command = 'winrs /r:' . $servername . ' /u:' . $username . ' /p:' . $password . ' sc query ' . $servicename . ' 2>&1';
exec($command, $output);
//Defines the server status as $servicestate which is stored in the fourth part of the command array.
//Then the string "STATE" and any number is stripped from $servicestate. This will leave only the status of the service (e.g. RUNNING or STOPPED).
$servicestate = $output[3];
$strremove = array('/STATE/','/:/','/[0-9]+/','/\s+/');
$servicestate = preg_replace($strremove, '', $servicestate);
//Define an invalid output. Sometimes the array is invalid. Catch this issue and restart the function for valid output.
//Typically this can be caught when the string "SERVICE_NAME" is found in $output[3].
$badservicestate = "SERVICE_NAME" . $servicename;
if($servicestate == $badservicestate) {
goto start;
}
//Service status (e.g. Running, Stopped Disabled) is returned as $servicestate.
return $servicestate;
}
The most straightforward solution, since you are calling an external process, and you actually need its output in your script, is to rewrite exec in terms of proc_open and non-blocking I/O:
function exec_timeout($cmd, $timeout, &$output = '') {
$fdSpec = [
0 => ['file', '/dev/null', 'r'], //nothing to send to child process
1 => ['pipe', 'w'], //child process's stdout
2 => ['file', '/dev/null', 'a'], //don't care about child process stderr
];
$pipes = [];
$proc = proc_open($cmd, $fdSpec, $pipes);
stream_set_blocking($pipes[1], false);
$stop = time() + $timeout;
while(1) {
$in = [$pipes[1]];
$out = [];
$err = [];
stream_select($in, $out, $err, min(1, $stop - time()));
if($in) {
while(!feof($in[0])) {
$output .= stream_get_contents($in[0]);
break;
}
if(feof($in[0])) {
break;
}
} else if($stop <= time()) {
break;
}
}
fclose($pipes[1]); //close process's stdout, since we're done with it
$status = proc_get_status($proc);
if($status['running']) {
proc_terminate($proc); //terminate, since close will block until the process exits itself
return -1;
} else {
proc_close($proc);
return $status['exitcode'];
}
}
$returnValue = exec_timeout('YOUR COMMAND HERE', $timeout, $output);
This code:
uses proc_open to open a child process. We only specify the pipe for the child's stdout, since we have nothing to send to it, and don't care about its stderr output. if you do, you'll have to adjust the following code accordingly.
Loops on stream_select(), which will block for a period up to the $timeout set ($stop - time()).
If there is input, it will var_dump() the contents of the input buffer. This won't block, because we have stream_set_blocking($pipe[1], false) on the pipe. You will likely want to save the content into a variable (appending it rather than overwriting it), rather than printing out.
When we have read the entire file, or we have exceeded our timeout, stop.
Cleanup by closing the process we have opened.
Output is stored in the pass-by-reference string $output. The process's exit code is returned, or -1 in the case of a timeout.
I want to create an easy PHP server (TCP-based) that would serve actual time and close the connection immediately. I've done that already. I wanted to add crtl-C handling so I needed to replace blocking socket_accept with non-blocking (this is because when the blocking socket_accept instruction is reached and I send SIGINT /ctrl-C/ then the server will still be alive until the first client is server and then it closes itself - and I didn't want this behavior).
My current code looks like this:
<?php
error_reporting(E_ALL);
ob_implicit_flush();
if ($argc != 2)
die("Wrong params");
$address = 'localhost';
$port = $argv[1];
if (($sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) === false)
die(socket_strerror(socket_last_error()) . "\n");
if (socket_bind($sock, $address, $port) === false)
die(socket_strerror(socket_last_error($sock)) . "\n");
if (socket_listen($sock, 5) === false)
die(socket_strerror(socket_last_error($sock)) . "\n");
socket_set_nonblock($sock);
$remote_host = $remote_port = $msgsock = null;
declare(ticks = 1);
function sig_handler($signo)
{
switch ($signo) {
case SIGTERM:
case SIGINT:
global $sock;
socket_shutdown($sock);
socket_close($sock);
echo "Terminating...\n";
exit;
}
}
pcntl_signal(SIGTERM, "sig_handler");
pcntl_signal(SIGINT, "sig_handler");
echo "Starting server\n";
while (1) {
do {
$msgsock = socket_accept($sock);
usleep(100000);
} while ($msgsock === false);
socket_getpeername($msgsock, $remote_host, $remote_port);
echo "Connection made from {$remote_host}:{$remote_port}\n";
$msg = date('r', time()) . "\n";
socket_write($msgsock, $msg, strlen($msg));
socket_close($msgsock);
};
socket_close($sock);
Everything works fine except for one detail... I get the following PHP warning every 0.1 second (= 100000 microseconds):
PHP Warning: socket_accept(): unable to accept incoming connection [11]: Resource temporarily unavailable in /home/tomasz/Development/Python/twisted/time-server.php on line 55
PHP Stack trace:
PHP 1. {main}() /home/tomasz/Development/Python/twisted/time-server.php:0
PHP 2. socket_accept() /home/tomasz/Development/Python/twisted/time-server.php:55
What I've tried to achieve is non-blocking accept: PHP uses the server socket, checks if there's any connection awaiting to be served. I not - wait 0.1 second. If there is a pending connection, serve it. All functionality is OK except that I've got no idea why is this warning thrown - I just want to check if there's any connection to be served. Modifying error_reporting to E_ERROR makes the warnings quiet, but I hope there's a better way to solve that...
edit:
modifying socket_accept($sock) to #socket_accept($sock) will just suspress warnings from being thrown, but still this doesn't state why it is thrown...
I located your question while searching for a solution to the exact same problem. Additionally, I found a few other posts asking about the same thing, but also without solutions. Some posts indicated that there was no way to prevent socket_accept() from throwing warnings, as it is by design to indicate "there is no waiting connection to accept." I couldn't confirm this as it doesn't seem to be mentioned in the PHP manual page for socket_accept()
Like you, I wasn't satisfied with using any sort of error suppression. It seemed the next logical step was to wrap socket_accept() in some sort of conditional so that it would only execute if I knew there was a connection waiting. I couldn't find anything that did this. But when using stream_*() functions instead of just socket_*() functions, it looks like there is. So I switched out to using streams (seems there are some other advantages as well), as follows:
if (( $socket = stream_socket_server( "tcp://$address:$port", $errno, $errstr )) === FALSE ) {
die( "failed to create socket: $errstr\n" );
}
echo "Waiting for clients to connect...\n";
while ( $server_listening ) {
$read = array( $socket );
$array = array();
if ( stream_select( $read, $array, $array, 0 )) {
$connection = stream_socket_accept( $socket, 0 );
client_handler( $socket, $connection );
} else {
usleep( 100 );
}
}
This seems to work well. My script only attempts to accept the connection if it first determines that there is a connection waiting. After going through this, I did find that there was an equivalent socket function for this, socket_select(), which appears to work the same way. So you may be able to do something similar if you wanted to stick with the socket_*() functions.
On a side note, I'm glad I made the switch to streams as they seem easier to work with. And since my application is limited to TCP, I don't seem to be missing any functionality that I would get with more low-level sockets.
There is something that does that, and it's select(). Nonblocking socket IO should use select(), period. In PHP that means socket_select(). See any reference on BSD sockets for more info.
This is what i want to accomplish using php (possibly using exce()?):
telnet to a whois registrar using a program called proxychains:
proxychains telent whois.someregistrar 43
if failed -> try 1 again
feed a domain name to the connection:
somedomainname.com
capture data returned by the registrar to php
I have no experience with shell scripting so how do i capture the event
in which telnet is connected and hangs for input and how do i "feed" it?
Am i totaly off here or is this the right way to go about it?
EDIT: i see python have a good way to handel this using expect
Here is a basic working example.
<?php
$whois = 'whois.isoc.org.il'; // server to connect to for whois
$data = 'drew.co.il'; // query to send to whois server
$errFile = '/tmp/error-output.txt'; // where stderr gets written to
$command = "proxychains telnet $whois 43"; // command to run for making query
// variables to pass to proc_open
$cwd = '/tmp';
$env = null;
$descriptorspec = array(
0 => array("pipe", "r"), // stdin is a pipe that the child will read from
1 => array("pipe", "w"), // stdout is a pipe that the child will write to
2 => array("file", "/tmp/error-output.txt", "a") // stderr is a file to write to
);
// process output goes here
$output = '';
// store return value on failure
$return_value = null;
// open the process
$process = proc_open($command, $descriptorspec, $pipes, $cwd, $env);
if (is_resource($process)) {
echo "Opened process...\n";
$readBuf = '';
// infinite loop until process returns
for(;;) {
usleep(100000); // dont consume too many resources
// TODO: implement a timeout
$stat = proc_get_status($process); // get info on process
if ($stat['running']) { // still running
$read = fread($pipes[1], 4096);
if ($read) {
$readBuf .= $read;
}
// read output to determine if telnet connected successfully
if (strpos($readBuf, "Connected to $whois") !== false) {
// write our query to process and append newline to initiate
fwrite($pipes[0], $data . "\n");
// read the output of the process
$output = stream_get_contents($pipes[1]);
break;
}
} else {
// process finished before we could do anything
$output = stream_get_contents($pipes[1]); // get output of command
$return_value = $stat['exitcode']; // set exit code
break;
}
}
echo "Execution completed.\n";
if ($return_value != null) {
var_dump($return_value, file_get_contents($errFile));
} else {
var_dump($output);
}
// close pipes
fclose($pipes[1]);
fclose($pipes[0]);
// close process
proc_close($process);
} else {
echo 'Failed to open process.';
}
This is meant to be run from the command line, but it doesn't have to be. I tried to comment it fairly well. Basically at the beginning you can set the whois server, and the domain to query.
The script uses proc_open to open a proxychains process that calls telnet. It checks to see if the process was opened successfully, and if so check that its status is running. While its running, it reads the output from telnet into a buffer and looks for the string telnet outputs to indicate we are connected.
Once it detects telnet connected, it writes the data to the process followed by a newline (\n) and then reads the data from the pipe where the telnet data goes. Once that happens it breaks out of the loop and closes the process and handles.
You can view the output from proxychains from the file specified by $errFile. This contains the connection information as well as debug information in the event of a connection failure.
There is probably some additional error checking or process management that may need to be done to make it more robust, but if you put this into a function you should be able to easily call it and check the return value to see if the query was successful.
Hope that gives you a good starting point.
Also check out this answer of mine for another working example of proc_open, this example implements a timeout check so you can bail if the command hasn't completed in a certain amount of time: Creating a PHP Online Grading System on Linux: exec Behavior, Process IDs, and grep
Here is the code that I am using:
if (!($fp = fsockopen('ssl://imap.gmail.com', '993', $errno, $errstr, 15)))
echo "Could not connect to host";
$server_response = fread($fp, 256);
echo $server_response;
fwrite($fp, "C01 CAPABILITY"."\r\n");
while (!feof($fp)) {
echo fgets($fp, 256);
}
I get the first response:
OK Gimap ready for requests from xx.xx.xx.xx v3if9968808ibd.15
but then the page times out. I have searched through stream_set_blocking, stream_set_timeout, stream_select, fread, etc. but could not get it to work. I need to read all the data that the server sends and then proceed with other commands (I would be retrieving emails using imap).
Thanks
Your script is hanging in the while loop at the end. This is because you have used !feof() as the condition for the loop, and the server is not closing the connection. This means the feof() will always return false and the loop will continue forever.
This will not be problem when your write a full implementation, as you will be looking for response codes and can break out of the loop accordingly, for example:
<?php
// Open a socket
if (!($fp = fsockopen('ssl://imap.gmail.com', 993, $errno, $errstr, 15))) {
die("Could not connect to host");
}
// Set timout to 1 second
if (!stream_set_timeout($fp, 1)) die("Could not set timeout");
// Fetch first line of response and echo it
echo fgets($fp);
// Send data to server
echo "Writing data...";
fwrite($fp, "C01 CAPABILITY\r\n");
echo " Done\r\n";
// Keep fetching lines until response code is correct
while ($line = fgets($fp)) {
echo $line;
$line = preg_split('/\s+/', $line, 0, PREG_SPLIT_NO_EMPTY);
$code = $line[0];
if (strtoupper($code) == 'C01') {
break;
}
}
echo "I've finished!";
Your script should be working. In fact, it is working.
See the results below on my pc when I ran your code:
* OK Gimap ready for requests from xx.xx.xx.xx l5if4585958ebb.20
* CAPABILITY IMAP4rev1 UNSELECT IDLE NAMESPACE QUOTA ID XLIST CHILDREN X-GM-EXT-1 XYZZY SASL-IR AUTH=XOAUTH
C01 OK Thats all she wrote! l5if4585958ebb.20
Since gmail doesn't disconnect you. No end of file occurs. And the page loading simply times out.
In other words: Your script will just keep waiting and waiting until gmail does disconnect, which unfortunately happens after your page load has already timed out.
I am trying to create a inetd-like service for Windows in PHP for future use with my other application.
So all I can think of is to use Steam Server and proc_open to pipe the stream directly to the process (like inetd). Because on Windows there is no pcntl_fork(), and PHP doesn't support threading.
So far, here is my code. The inetdtest program is a simple program with single printf (written in C). But the problem is that when I connected to my server (via netcat), I got no response message.
<?php
define ('SERVICE_COMMAND', 'inetdtest');
define ('SERVICE_PORT', 35123);
function main() {
echo "Simple inetd starting...\n";
$socket = stream_socket_server('tcp://0.0.0.0:' . SERVICE_PORT, $errno, $errstr, STREAM_SERVER_BIND|STREAM_SERVER_LISTEN);
if ($socket === false) {
echo "Can't bind to service port.\n";
echo "[$errno] $errstr";
die(1);
}
$processes = array();
while (true) {
$current = #stream_socket_accept($socket, 5, $host);
if ($current !== false) {
echo 'Incomming connection from client ' . $host . "\n";
echo "Lunching child process... ";
$io = array(
0 => $current,
1 => $current,
2 => array('file', 'stderr.log', 'a')
);
$proc = proc_open(SERVICE_COMMAND, $io, $pipes, NULL, NULL, array('bypass_shell'));
$status = proc_get_status($proc);
echo " DONE! PID : {$status['pid']}\n";
$processes[] = array($current, $proc);
}
foreach ($processes as $k=>$v) {
$status = proc_get_status($v[1]);
if (false === $status['running']) {
echo "Finalizing process {$status['pid']}... ";
fflush($v[0]);
fclose($v[0]);
proc_close($v[1]);
unset($processes[$k]);
echo "DONE!\n";
}
}
}
}
main();
The code justs works as it stands here (using cat as program and on linux), so the problem lies somewhere in the windows side of things.
For one thing, the option you are passing, to bypass the shell, should be given as
array('bypass_shell'=>true)
This may fix things already. The tricky part with these things, is that you're passing a socket fd to a process, which may or may not be expected to handle that properly. I don't know how these things are done in windows, but cutting cmd out of the equation can only help.
If it still doesn't work, you should create a loop which waits for data (either from network or child processes) and sends data from the network socket to the process pipe, and vice versa.