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ankit
Asked: 2011-02-05 16:33:53 +0800 CST

PHP Execute Ping Command

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I have asked this question before but with not much success. I guess i was confused and did not put my question properly. So here it goes again.

Some points before i begin:

  1. I am running FC 14
  2. I did not install apache manually ... used yum
  3. safe mode in PHP is turned OFF

Basically I want to execute ping command and show the results on the PHP page. The code I use is

<?php
$who = shell_exec('whoami');
$result1 = shell_exec("/webserver_commands/ping -c 4 www.google.com");
exec("ping -c 4 www.google.com",$result2);

echo $who;
echo "<br/>".$result1;
echo "<br/>".$result2;
?>

The Output I get is

apache 

Array

So I know the scripts are being run as the user 'apache'

In the apache log I see the following lines

sh: /webserver_commands/ping: Permission denied
ping: icmp open socket: Permission denied

I have made sure the directory /webserver_commands/ and the file ping in it are owned by the user apache of the group apache

917506 drwxrwxrwx.   2 apache apache  4096 Feb  4 18:29 webserver_commands
917507 -rwxrwxrwx. 1 apache apache 43448 Feb  4 18:29 ping

Any ideas what could be going wrong here ?

thank you, -ankit

php apache-2.2 bash

3 Answers

  1. if you want to display $result2 you need to implode it. exec() puts its output into the second argument as an array. So

    print(implode("<br>",$result2));

    Or echo, whatever your preference

    As for ping, its not working because it lost the setuid bit when you copied it. You need to do

    chown root /webserver_commands/ping
chmod u+s /webserver_commands/ping
    • 2
  2. Best Answer

    apache user does not have sufficient rights to send ICMP packets, consider using Net_Ping library from PEAR instead. If you are using Debian it can be installed using apt-get install php-net-ping

    • 1

  3. One potential cause is that ping is by design a root-only command so, in order to execute it from non-root users, many distributions have the setuid bit set on 'ping'; however, conversely, many do not - this may include FC14

    If ping does not have the setuid bit set, and if you are willing to open up this potential (but unlikely) security hole you can chmod u+s on ping to allow it to be executed from any user.

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