First, some background info. What I'm trying to do is essentially a port sniff. I'm trying to connect to a host and determine if a port is open, closed or blocked. I used to do this using the fsockopen( ) function. It lets you set a timeout for initiating the connection, and life was good. But then I started running this website on it's own unique IP address, and so I have to bind the connection to this IP. You can't do this with fsockopen( ) but you can do it with socket_create( ) and related functions.
So I've switched to using these functions, but now I have a new problem. I seem to be able to create read and write timeouts, but no timeout for actually creating the connection. I've tried setting send and receive timeouts, and setting the default_socket_timeout value. I set both to timeout in 2 seconds, but it still takes 75 seconds to timeout.
Also to be clear, this code works fine for most hosts. The problem is running it on a host that has the port blocked via firewall. socket_connect( ) eventually returns an error #60, as it should, for a timed-out connection. The problem is how long that error takes (75 seconds).
$sock = socket_create(AF_INET,SOCK_STREAM,SOL_TCP);
socket_set_option($sock, SOL_SOCKET, SO_RCVTIMEO, array("sec" => 1, "usec" => 0));
socket_set_option($sock, SOL_SOCKET, SO_SNDTIMEO, array("sec" => 1, "usec" => 0));
$sock_status = @socket_connect($sock,$ip,$port);
In the above code: OPERATING_IP is a constant of the IP address I am binding to, $ip is the IP address I am connecting to. This will be any user anywhere on the internet. I do not control or know anything about it, $port is the specific port I am testing
So just to reiterate, how can I set a timeout for actually initiating the TCP connection using socket_connect( )? I tried (in lines 1, 4 & 5) to set it to a short timeout of 2 seconds, but it still takes 75 seconds to timeout, when connecting to hosts that block connections.