Edit report at http://bugs.php.net/bug.php?id=52848&edit=1
ID: 52848
Updated by: srina...@php.net
Reported by: php dot net at phrozenbyte dot de
Summary: Processing out-of-band data doesn't work
Status: To be documented
Type: Bug
Package: Streams related
Operating System: Ubuntu 10.04 Lucid Lynx
PHP Version: 5.3.3
Block user comment: N
New Comment:
few additional comments
on Linux/Solaris socket implementations, when you send with MSG_OOB
flags set, only the last byte is recvd. the subsequent recv call will
flush out the rest of the bytes.
for example, in your example,if you edit it like below you will notice
this more clearly:
client script
<?php
$socket = stream_socket_client('tcp://127.0.0.1:1234');
stream_socket_sendto($socket, '123456789', STREAM_OOB);
fclose($socket);
?>
server (with 2 recv calls even though client is sending only one send
call.)
<?php
$server = stream_socket_server('tcp://127.0.0.1:1234');
stream_set_timeout($server, 180);
$socket = stream_socket_accept($server);
echo "Data: '".stream_socket_recvfrom($socket, 100, STREAM_OOB)."'\n";
echo "Data: '".stream_socket_recvfrom($socket, 100)."'\n";
?>
Hope this clarifies
I don't think this is an issue with PHP.
Previous Comments:
------------------------------------------------------------------------
[2010-09-15 22:17:16] php dot net at phrozenbyte dot de
When you're sending data out-of-band (one or more bytes make no
difference) and the client socket is in $read and $except of
stream_select() the socket will be available every time in both arrays.
------------------------------------------------------------------------
[2010-09-15 20:41:18] php dot net at phrozenbyte dot de
Ok, thanks. As cataphract at php dot net mentioned first there are
situations on which even that single byte isn't shown. I'm not able to
reproduce the bug, the only possibility is to repeat running my test
server and client. After some trys the script will result in
OOB-Data 1/2: ''
OOB-Data 2/2: ''
Data 1/2: '12345678'
Data 2/2: ''
------------------------------------------------------------------------
[2010-09-15 16:15:20] cataphr...@php.net
It should be documented in stream_socket_sendto and
stream_socket_recvfrom, that OOB data can be only one byte long.
------------------------------------------------------------------------
[2010-09-15 16:13:20] cataphr...@php.net
"In Transmission Control Protocol (TCP), the OOB data block is always
one byte. Therefore, if you send multiple-byte OOB data, only the last
byte of the OOB data is retrieved. The remaining data is treated like
normal data."
See also http://support.microsoft.com/kb/830597
------------------------------------------------------------------------
[2010-09-15 14:44:54] cataphr...@php.net
Sorry, correction: Windows presented the same behavior.
------------------------------------------------------------------------
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