The hosting service that I use currently does not let me use sockets, probably for good reason on their part. They do, however, let me use fsockopen. I was wondering what the difference is, because some scripts that worked with socket_create and even stream_socket_server, do not work with fsockopen. That said, if fsockopen should work, my code is listed below. What it does is it listens on its own ip address for incoming udp packets and reads them.
Thanks
$sock = fsockopen("udp://x.x.x.x", $port);
while(1)
{
$buf = fread($sock, 200);
flush();
ob_flush();
}
fsockopen creates a connection to a host, not a listening socket.
fsockopen($address) ~== socket_connect(socket_create(), $address)
Your hosting provider doesn't want you listening on alternate ports/protocols.
If what you have works, I wouldn't count on it always working as it would be a bug.
Related
So Im trying to get my head wrapped around this....
I open the port
$remip = $_SERVER['SERVER_ADDR']; //Grab my server address
$fp = fsockopen($remip, 80, $errno, $errstr, 10);//Godaddy hosting only 80 and 443 ports work
//fsockopen(ip address , port, IDK, IDK, timeout delay)
so now the ports open or if not maybe some error checking to be sure
if (!$fp) { echo "$errstr ($errno)<br>\n"; exit; } //Not sure what this echos out but its clear how it stops errors
So now that the port is open any ip/client can connect on this port????
Ill assume I can now connect....
So on my client I open a socket to my server ip address port tcp connection.....
The php file includes something like
else {$out = "hello, 80\r\n"; //out specifies the string to be written , bytes to write
fwrite($fp, $out); //$fp is the handle
fclose($fp)}//close the connection
at this point ill assume that my client gets the hello written to it ..
finish up by closing the connection
Im entirely new to this so Im attempting to understand some sample code here...
So how long is this socket open for? If i want to keep this port open do i need to do a cron job to launch this file periodically.
Im 100% sure that I have got something wrong here so please set me straight.
I think you have a misconception of what fsockopen does. In your example your fsockopen does not actually open port 80 (as in opening a server socket), but it opens a client socket that connects to port 80 on the server itself. It actually does open a (client) port which gets a (not completely) random number.
After you connected using fsockopen you can send HTTP commands to the webserver such as GET /index.php
What you need to use is socket_listen() and socket_bind(). There are a few places in the docs that show you how to get PHP listening on a socket: http://www.php.net/manual/en/function.socket-listen.php
I suggest you read and try them out by simply testing then with a unix tool called netcat (nc <ip_address> <port> command normally)
I am currently using PHP to open up a port 43 connection to get whois information directly from a registry using this code.
// connecting to the whois server.
$handle = fsockopen($server, 43);
if (!$handle)
return false; // connection failure
//asking the server
fwrite($handle, $domain_name."\r\n");
// getting response
$response = '';
while (!feof($handle))
$response .= fgets($handle, 1024);
fclose($handle);
It works great however I want to connect though a proxy server so I route my intertent connection through it. If this were able to use cURL I would use curl_setopt($curl_handle, CURLOPT_PROXY, $ip_address . ':4040'); but i can not find a way to do this using fsocketopen. How can I accomplish this either with cURL or fsocketopen()?
Sockets dont have proxy. Just gateways and routers are in-the-middle (if any). You were talking about cURL, that it has proxy - it only uses http/s proxy service. For example, if you have http proxy service on server example.com:8080 you first need to open connection to server example.com (socket) on port 8080 and then send your request, proxy will forward your request and return response. In your case, you just open tcp connection on port 43 on specific host and exchange data directly with target server. If you dont want to do this directly and reveal your ip (or something) you'll need some service too. If you have access to other machine you could use it to do the job. If you want to do it manually you could use ssh or something like that, if you want to make it automatized, you'll probably need to write service on your middle server because you probably wont find any public proxy servers with other protocols than popular http, ftp, ...
Hope this helps.
By the way I see no reason why you should use proxy on whois service.
You could use a SOCKS proxy to relay the TCP connection from your machine to the SOCKS server to the WHOIS server but you would have to implement the SOCKS communication protocol over fsockopen.
Another method would be to use ProxyChains on the server and execute it via PHP. I've answered a similar question here ( How to capture and feed telnet using php and shell scripting? ) which shows how to invoke proxychains from PHP to execute a WHOIS command on a remote server and read the response.
I'm trying to make a simple listener on port 8195. When I try the following code block in PHP CLI conditions, it only shows 'Test' once, then hangs. If I delete the file 'votifier.run', the file designed to be the on/off switch, it still continues to hang. It never shows 'Client connected'.
Furthermore, if I try to connect to the host via Telnet on port 8195 while the script is running, I simply get a connection failed message. It's like it's looking for one connection and just not giving up.
// Set the IP and port to listen to
$address = 'localhost';
$port = 8195;
// Create a TCP Stream socket
$sock = socket_create(AF_INET, SOCK_STREAM, 0);
// Bind the socket to an address/port
socket_bind($sock, $address, $port);
// Start listening for connections
socket_listen($sock);
// Loop continuously
while ( file_exists('votifier.run') ) {
echo 'Test';
$client = socket_accept($sock);
if( $client ) {
echo 'Client connected';
// Don't hang on slow connections
socket_set_timeout($client, 5);
// Send them our version
socket_write("VOTIFIER MCWEBLINK\n");
// Read the 256 byte block
$block = socket_read($client, 256);
...
The answer:
socket_accept() will usually hang until a connection is made. If a connection attempt was made, the script would continue, but because the socket was being created on localhost, it would only accept connections to it from localhost.
The fix is to use your external IP rather than 'localhost' or '127.0.0.1'. Then you can Telnet to it.
I'm just guessing here, but could it be that the address you are trying to bind to should not be a hostname?
If the socket is of the AF_INET family, the address is an IP in dotted-quad notation (e.g. 127.0.0.1).
EDIT
Ok, I've taken your script and tried to reproduce your error but couldn't. There are a couple of flaws in it but none that would cause a telnet client's connection attempt to fail.
Since none of the aforementioned applies, let's go thru the checklist one by one:
sockets module loaded/compiled
localhost does resolve to 127.0.0.1
the port isn't taken by any other application running
there's no rule of any sort of firewall that would prevent communication between the telnet client and your server
the machine which you connect from is allowed to connect to the server host (try the same host if it isn't)
the file that's being checked in the while-loop does exist
you are sure that there isn't another fatal error within your script that would prevent the snippet you posted from running
These are all the possible error sources I can think of, atm. Try fixing up the minor flaws first, then go thru the checklist.
if( $client ) {
echo 'Client connected';
// Don't hang on slow connections
socket_set_option(
$client,
SOL_SOCKET,
SO_RCVTIMEO | SO_SNDTIMEO,
array('sec' => 5, 'usec' => 0)
);
// Send them our version
socket_write($client, "VOTIFIER MCWEBLINK\n");
^^^^^^^
// Read the 256 byte block
$block = socket_read($client, 256);
You should be using threads. If the client never sends anything your code will block in the read() method. Each accepted socket should be completely handled in a new thread.
You may want to check this:
PHP Votifier example for Minecraft Topsites
It explains how the code works, it's the basic function that makes the encryption, fills up the 256 blank spaces and sends the packet too. You can work a little with it as you may want to improve it.
You can see a live demo of the running php for the plugin here: http://topg.org/test_votifier
I tryed to create a socket in php and reuse it from other process.
I know this can be done with a daemon script but I want to do this without.
I created a socket and binded it to a specific port.
$sock = socket_create (AF_INET, SOCK_STREAM, SOL_TCP);
socket_set_option ($sock, SOL_SOCKET, SO_REUSEADDR, 1);
socket_bind ($sock, 'xx.xx.xx.xx', 10000);
socket_connect ($sock, $host, $port);
And from another php file I did the same thing. But the packets that I send from the 2 file are not "validated" by host. I sniffed all ports and I see that it uses same local and destination port. I don't understand where is the problem.
Can you help me with this?
It's ok in any other programming language, or any other solution for this.
Andrew
Sockets are not symmetrical. The server side listens on a specific port for a client to conect - the client does not specify the local port - only the remote port and address. Its nothing to do with the language you implement it in.
There's a very good socket server implementation available at http://www.phpclasses.org/browse/package/5758.html with examples.
C.
You can't really use persistent sockets in php. When you execute a php file, a new process is created which cannot access the variables - or sockets - of a different php process so it won't know if there already exists a socket and just creates it.
I'm trying to connect to gmail pop server from a phplist installation and it fails, but i'm not sure whether my webhost opened port 995 or not. They say they have opened it, but i'm in doubt. Is there a way i can check it from a php script? They are running php 5.2.0 on a windows server, though i'm not sure what OS is that. phpinfo() says "Windows NT DEDI514 5.2 build 3790"
You can put code in a php script to open a connection to a specific hostname (or IP address) and port.
If you know the expected response, you should be able to tell if you are getting a connection. If you get something like "Connection refused", then either you are being blocked, or the destination host is not accepting connections on that port.
This example uses IP address 192.0.2.0 and port 995. Replace these with whatever you want to test.
<?php
echo "\nOpening connection\n\n";
$fp = fsockopen("192.0.2.0", 995, $errno, $errstr);
if (!$fp) {
echo "ERROR: $errno - $errstr\n";
} else {
echo fread($fp, 1024);
fclose($fp);
}
?>
You can also send data to the server using
fwrite($fp, "blah blah blah\r\n");
There is more information about fsockopen here.
I think you'll need to ping or traceroute to a machine that will respond on that port.
This article should have much more than you want to know, but there's an example script at the bottom that you can modify to test.
http://www.planet-source-code.com/vb/scripts/ShowCode.asp?lngWId=8&txtCodeId=1786
There are some other scripts here:
http://www.theworldsend.net/
I can't vouch for any of these personally, but they look like what you need.
And, of course, if you can ssh or telnet into your server, you can do all this much more easily using the ping and traceroute commands.
Maybe safe mode is active? This prevents calling services on other servers.
Edit:
All filesystem and stream functions are affected by the safe mode settings!
The open_basedir setting affects fopen()!