Specify source port range with curl using PHP

Question

I need to specify the source port range for curl.
I don't see any option who let me choose a range for source port in TCP.

Is it possible?

That doesn't make sense. Why do you want to connect to a range of ports? — slugonamission, Feb 19 '13 at 14:27
There is a firewall who block curl traffic if the source port is below 20000... Is have no time to wait for the network guys ;) — hotips, Feb 19 '13 at 14:31
But what do you mean by connecting to a range of ports? A TCP connection only connects to a single port... — slugonamission, Feb 19 '13 at 14:32
Curl have to use a port inside a specific range e.g. 30.000 to 65535 — hotips, Feb 19 '13 at 14:43

score 4 · Answer 1 · answered Jan 21 '21 at 13:22

You can use CURLOPT_LOCALPORT and CURLOPT_LOCALPORTRANGE options, which are similar to curl's --local-port command line option.

In the following example curl will try to use source port in range 6000-7000:

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_LOCALPORT, 6000);
curl_setopt($ch, CURLOPT_LOCALPORTRANGE, 1000);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$result = curl_exec($ch);
curl_close($ch);
echo $result;

From the command line one would use:

curl --local-port 6000-7000 <url>

For documentation see: CURLOPT_LOCALPORT and Local port number.

score 1 · Answer 2 · answered Feb 19 '13 at 14:41

I think it would be better using fsockopen. I came up many times this worked for me when blocked by firewalls. See: http://php.net/fsockopen

$ports = array(80, 81);
foreach ($ports as $port) {
    $fp =@ fsockopen("tcp://127.0.0.1", $port);
    // or fsockopen("www.google.com", $port);
    if ($fp) {
        print "Port $port is open.\n";
        fclose($fp);
    } else {
        print "Port $port is not open.\n";
    }
}

By the way, there is CURLOPT_PORT for CURL, but doesn't work with tcp://127.0.0.1;

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://127.0.0.1");
curl_setopt($ch, CURLOPT_PORT, 80);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); 
$re = curl_exec($ch);
// echo curl_errno($ch);
curl_close($ch);
print $re;

CURLOPT_PORT is normally for the distant port : CURLOPT_PORT An alternative port number to connect to. — hotips, Feb 19 '13 at 14:53
They are asking to set the port for the connection to connect **from**, not **to**. — gre_gor, Oct 11 '22 at 16:01

Specify source port range with curl using PHP

2 Answers2