ID: 40674
User updated by: matth at mystictrd dot com
Reported By: matth at mystictrd dot com
Status: Open
Bug Type: Sockets related
Operating System: Debian 3.1
PHP Version: 5.2.1
New Comment:
The way it seems this should work (I easily could be completely off
base) is:
socket_bind could be defined as:
bool socket_bind ( resource $socket, string $address [, int $port [,
string $mac or $iface ]] )
Previous Comments:
------------------------------------------------------------------------
[2007-03-02 17:21:23] matth at mystictrd dot com
I believe in C/C++ you can specify hardware addresses to listen on -
specifically either a MAC address/an interface name (eth0 in linux).
After doing some tests in C it seems that if you listen on an ip (i.e.
192.168.0.1) and you will not see that type of packet but if you listen
on 0.0.0.0 or INADDR_ANY you can see it.
------------------------------------------------------------------------
[2007-03-01 17:38:01] matth at mystictrd dot com
Ignore my previous workaround example, it did not work as expected.
------------------------------------------------------------------------
[2007-03-01 17:25:57] matth at mystictrd dot com
The reason why is if you take a normal DHCP server you can typically
listen on multiple interfaces. If one wanted to know what interface is
receiving the data you would think to bind on the interfaces IP address.
But since you cannot see that type of packet binding to an IP like that
you must bind to 0 or 0.0.0.0 which doesn't help with knowing what
interface recieved the data since the data does not contain information
about interface mac/ip destination from the client. I'm not positive if
this is a PHP issue or not but I believe you can do it in C/C++ and
that you should be able to do it with PHP. A work around I'm
experimenting with goes as:
<?php
$interface_ip = "10.66.66.1";
$interface_port = 67;
//listens for dhcp requests
$socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
//you must bind to 0.0.0.0 to actually see anything
socket_bind($socket, 0, 67);
while(1)
{
if($src = @socket_recvfrom($socket, $data, 9999, 0, $interface_ip,
$interface_port))
{
echo "data!\n";
}
}
?>
------------------------------------------------------------------------
[2007-03-01 09:01:09] [EMAIL PROTECTED]
And why do you think it's PHP related?
------------------------------------------------------------------------
[2007-03-01 00:41:33] matth at mystictrd dot com
Description:
------------
A SOCK_DGRAM SOL_UDP socket using socket_bind to an IP address
associated with an interface will not see UDP broadcasts destined to
255.255.255.255. I do not know if this is intended but you can see
them
when listening on 0.0.0.0
Reproduce code:
---------------
<?php
//listens for dhcp requests
$socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
//you must bind to 0.0.0.0 to actually see anything
socket_bind($socket, "10.66.66.1", 67);
while(1)
{
if($src = @socket_recv($socket, $data, 9999, 0))
{
echo "data!\n";
}
}
?>
Expected result:
----------------
When a DHCP request is made we should see "data!" echoed.
Actual result:
--------------
Nothing was read on the interface - it can only see localhost or direct
packets sent to it (destination interface IP address).
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=40674&edit=1
