Bug #75283 [Opn->Fbk]: Disconnection not detected by socket_read()

Edit report at https://bugs.php.net/bug.php?id=75283&edit=1 ID: 75283 Updated by: cmb@php.net Reported by: privacy dot and dot spam dot protection at gmx dot fr Summary: Disconnection not detected by socket_read() -Status: Open +Status: Feedback Type: Bug Package: Sockets related Operating System: Debian PHP Version: 7.0.24 -Assigned To: +Assigned To: cmb Block user comment: N Private report: N New Comment: Is this still an issue with any of the actively supported PHP versions[1]? [1] <https://www.php.net/supported-versions.php> Previous Comments: ------------------------------------------------------------------------ [2017-09-29 13:18:09] privacy dot and dot spam dot protection at gmx dot fr I haven't got server code because I use an RS232 TCP/IP converter's box. Problem happens when there's an ellectric shutdown, PHP socket_read function doesn't detect disconnection ------------------------------------------------------------------------ [2017-09-29 11:13:27] requinix@php.net Looks like the socket is still open, not reset. I haven't been able to reproduce your output in a way where the socket is reset/closed. What's the server code? What's the actual client code that sends data to the server in order to trigger the RST? ------------------------------------------------------------------------ [2017-09-29 09:54:56] privacy dot and dot spam dot protection at gmx dot fr Description: ------------ According to documentation, an empty string ("") is returned by socket_read() when there's no more data to read and false value on error (including if the remote host has closed the connection). However when socket_read has no data to read false is still returned. So it's impossible to detect if connection has been reseted by pear. Test script: --------------- $co = false; while (!$co) { $socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP); if ($socket !== false) echo "OK 1.\n"; $result = socket_connect($socket, $address, $service_port); if ($socket !== false) { socket_set_option($socket, SOL_SOCKET, SO_RCVTIMEO, array("sec" => 1, "usec" => 1)); echo "OK 2.\n"; $co = true; } } while (true) { socket_clear_error($socket); $out = socket_read($socket, 2048); $socket_last_error = socket_last_error($socket); $strErr = socket_strerror($socket_last_error) . ' ' . $socket_last_error; echo date('Ymd H:i:s') . " : $strErr ($socket_last_error) => " . var_export($out, true) . PHP_EOL; } Expected result: ---------------- OK 1. Try connection '9.3.0.23' on port '30001'... OK 2. // client's connected on server // no data have been sent by server 20170929 11:09:17 : Success 0 (0) => '' 20170929 11:09:18 : Success 0 (0) => '' 20170929 11:09:19 : Success 0 (0) => '' //server send data 20170929 11:09:19 : Success 0 (0) => 'a' 20170929 11:09:19 : Success 0 (0) => 'a' 20170929 11:09:20 : Success 0 (0) => 'a' 20170929 11:09:20 : Success 0 (0) => 'a' 20170929 11:09:20 : Success 0 (0) => 'a' 20170929 11:09:20 : Success 0 (0) => 'a' 20170929 11:09:20 : Success 0 (0) => 'a' // no data have been sent by server 20170929 11:09:21 : Success 0 (0) => '' 20170929 11:09:22 : Success 0 (0) => '' 20170929 11:09:23 : Success 0 (0) => '' // connection is reset by server 20170929 11:09:24 : Resource temporarily unavailable 11 (11) => false 20170929 11:09:25 : Resource temporarily unavailable 11 (11) => false 20170929 11:09:26 : Resource temporarily unavailable 11 (11) => false 20170929 11:09:27 : Resource temporarily unavailable 11 (11) => false 20170929 11:09:28 : Resource temporarily unavailable 11 (11) => false Actual result: -------------- OK 1. Try connection '9.3.0.23' on port '30001'... OK 2. // client's connected on server // no data have been sent by server 20170929 11:09:17 : Resource temporarily unavailable 11 (11) => false 20170929 11:09:18 : Resource temporarily unavailable 11 (11) => false 20170929 11:09:19 : Resource temporarily unavailable 11 (11) => false //server send data 20170929 11:09:19 : Success 0 (0) => 'a' 20170929 11:09:19 : Success 0 (0) => 'a' 20170929 11:09:20 : Success 0 (0) => 'a' 20170929 11:09:20 : Success 0 (0) => 'a' 20170929 11:09:20 : Success 0 (0) => 'a' 20170929 11:09:20 : Success 0 (0) => 'a' 20170929 11:09:20 : Success 0 (0) => 'a' // no data have been sent by server 20170929 11:09:21 : Resource temporarily unavailable 11 (11) => false 20170929 11:09:22 : Resource temporarily unavailable 11 (11) => false 20170929 11:09:23 : Resource temporarily unavailable 11 (11) => false // connection is reset by server 20170929 11:09:24 : Resource temporarily unavailable 11 (11) => false 20170929 11:09:25 : Resource temporarily unavailable 11 (11) => false 20170929 11:09:26 : Resource temporarily unavailable 11 (11) => false 20170929 11:09:27 : Resource temporarily unavailable 11 (11) => false 20170929 11:09:28 : Resource temporarily unavailable 11 (11) => false ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=75283&edit=1