Posts Tagged ‘Mode’

CentOS disable SELinux permanently or one time on grub Linux kernel boot time

Saturday, July 24th, 2021

selinux-artistic-penguin-logo-protect-data

 

1. Office 365 cloud connected computer and a VirtualBox hosted machine with SELINUX preventing it to boot

At my job we're in process of migrating my old Lenovo Laptop Thinkpad model L560 Laptop to Dell Latitude 5510 wiith Intel Core i5 vPro CPU and 256 Gb SSD Hard Drive.  The new laptops are generally fiine though they're not even a middle class computers and generally I prefer thinkpads. The sad thing out of this is our employee decided to migrate to Office 365 (again perhaps another stupid managerial decision out of an excel sheet wtih a balance to save some money … 

As you can imagine Office 365 is not really PCI Standards compliant and not secure since our data is stored in Microsoft cloud and theoretically Microsoft has and owns our data or could wipe loose the data if they want to. The other obvious security downside I've noticed with the new "Secure PCI complaint laptop" is the initial PC login screen which by default offers fingerprint authentication or the even worse  and even less secure face recognition, but obviosly everyhing becomes more and more crazy and people become less and less cautious for security if that would save money or centralize the data … In the name of security we completely waste security that is very dubious paradox I don't really understand but anyways, enough rant back to the main topic of this article is how to and I had to disable selinux?

As part of Migration I've used Microsoft OneDrive to copy old files from the Thinkpad to the Latitude (as on the old machine USB's are forbidden and I cannot copy over wiith a siimple USB driive, as well as II have no right to open the laptop and copy data from the Hard driive, and even if we had this right without breaking up some crazy company policy that will not be possible as the hard drive data on old laptop is encrypted, the funny thing is that the new laptop data comes encrypted and there is no something out of the box as BitDefender or McAffee incryption (once again, obviously our data security is a victim of some managarial decisions) …
 

2. OneDrive copy problems unable to sync some of the copied files to Onedrive


Anyways as the Old Laptop's security is quite paranoid and we're like Fort Nox, only port 80 and port 443 connections to the internet can be initiated to get around this harsh restrictions it was as simple to use a Virtualbox Virtual Machine. So on old laptop I've installed a CentOS 7 image which I used so far and I used one drive to copy my vbox .vdi image on the new laptop work machine.

The first head buml was the .vdi which seems to be prohibited to be copied to OneDrive, so to work around this I had to rename the origianl CentOS7.vdi to CentOS7.vdi-renamed on old laptop and once the data is in one drive copy my Vitualbox VM/ directory from one drive to the Dell Latitude machine and rename the .vdi-named towards .vdi as well as import it from the latest installed VirtualBox on the new machine.
 

3. Disable SELINUX from initial grub boot


So far so good but as usual happens with miigrations I've struck towards another blocker, the VM image once initiated to boot from Virtualbox badly crashed with some complains that selinux cannot be loaded.
Realizing CentOS 7 has the more or less meaningless Selinux, I've took the opportunity to disable SeLinux.

To do so I've booted the Kernel with Selinux disabled from GRUB2 loader prompt before Kernel and OS Userland boots.

 

 

I thought I need to type the information on the source in grub. What I did is very simple, on the Linux GRUB boot screen I've pressed

'e' keyboard letter

that brought the grub boot loader into edit mode.

Then I had to add selinux=0 on the edited selected kernel version, as shown in below screenshot:

selinux-disable-from-grub.png

Next to boot the Linux VM without Selinux enabled one time,  just had to press together

Ctrl+X then add selinux=0 on the edited selected kernel version, that should be added as shown in the screenshot somewhere after the line of
root=/dev/mapper/….

4. Permanently Disable Selinux on CentOS 7


Once I managed to boot Virtual Machine properly with Oracle Virtualbox, to permanently disabled selinux I had to:

 

Once booted into CentOS, to check the status of selinux run:

 

# sestatus
Copy
SELinux status:                 enabled
SELinuxfs mount:                /sys/fs/selinux
SELinux root directory:         /etc/selinux
Loaded policy name:             targeted
Current mode:                   enforcing
Mode from config file:          enforcing
Policy MLS status:              enabled
Policy deny_unknown status:     allowed
Max kernel policy version:      31

 

5. Disable SELinux one time with setenforce command


You can temporarily change the SELinux mode from targeted to permissive with the following command:

 

# setenforce 0


Next o permanently disable SELinux on your CentOS 7 next time the system boots, Open the /etc/selinux/config file and set the SELINUX mod parameter to disabled.

On CentOS 7 you can  edit the kernel parameters in /etc/default/grub (in the GRUB_CMDLINE_LINUX= key) and set selinux=0 so on next VM / PC boot we boot with a SELINUX disabled for example add   RUB_CMDLINE_LINUX=selinux=0 to the file then you have to regenerate your Grub config like this:
 

# grub2-mkconfig -o /etc/grub2.cfg
# grub2-mkconfig -o /etc/grub2-efi.cfg


Further on to disable SeLinux on OS level edit /etc/selinux
 

Default /etc/selinux/config with selinux enabled should look like so:

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#       enforcing – SELinux security policy is enforced.
#       permissive – SELinux prints warnings instead of enforcing.
#       disabled – No SELinux policy is loaded.
SELINUX=enforcing
# SELINUXTYPE= can take one of these two values:
#       targeted – Targeted processes are protected,
#       mls – Multi Level Security protection.
SELINUXTYPE=targeted


To disable SeLinux modify the file to be something like:

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#       enforcing – SELinux security policy is enforced.
#       permissive – SELinux prints warnings instead of enforcing.
#       disabled – No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of these two values:
#       targeted – Targeted processes are protected,
#       mls – Multi Level Security protection.
SELINUXTYPE=targeted

6. Check SELINUX status is disabled

# sestatus

SELinux status:                 disabled

So in this article shottly was explained shortly the fake security adopted by using Microsoft Cloud environment Offiice 365, my faced OneDrive copy issues (which prevented even my old laptop Virtual Machine to boot properly and the handy trick to rename the file that is unwilling to get copied from old PC towards m$ OneDrive as well as the grub trick to disable Selinux permanently from grub2.

Fix Zabbix selinux caused permission issues on CentOS 7 Linux / cannot set resource limit: [13] Permission denied error solution

Tuesday, July 6th, 2021

zabbix-selinux-logo-fix-zabbix-permission-issues-when-running-on-ceontos-linux-change-selinux-to-permissive-howto.

If you have to install Zabbix client that has to communicate towards Zabbix server via a Zabbix Proxy you might be unpleasently surprised that it cannot cannot be start if the selinux mode is set to Enforcing.
Error message like on below screenshot will be displayed when starting proxy client with systemctl.

zabbix-proxy-cannot-be-started-due-to-selinux-permissions

In the zabbix logs you will see error  messages such as:
 

"cannot set resource limit: [13] Permission denied, CentOS 7"

 

29085:20160730:062959.263 Starting Zabbix Agent [Test host]. Zabbix 3.0.4 (revision 61185).
29085:20160730:062959.263 **** Enabled features ****
29085:20160730:062959.263 IPv6 support: YES
29085:20160730:062959.263 TLS support: YES
29085:20160730:062959.263 **************************
29085:20160730:062959.263 using configuration file: /etc/zabbix/zabbix_agentd.conf
29085:20160730:062959.263 cannot set resource limit: [13] Permission denied
29085:20160730:062959.263 cannot disable core dump, exiting…

 

Next step to do is to check whether zabbix is listed in selinux's enabled modules to do so run:
 

[root@centos ~ ]# semodules -l

…..
vhostmd    1.1.0
virt    1.5.0
vlock    1.2.0
vmtools    1.0.0
vmware    2.7.0
vnstatd    1.1.0
vpn    1.16.0
w3c    1.1.0
watchdog    1.8.0
wdmd    1.1.0
webadm    1.2.0
webalizer    1.13.0
wine    1.11.0
wireshark    2.4.0
xen    1.13.0
xguest    1.2.0
xserver    3.9.4
zabbix    1.6.0
zarafa    1.2.0
zebra    1.13.0
zoneminder    1.0.0
zosremote    1.2.0

 

[root@centos ~ ]# sestatus
# sestatusSELinux status:                 enabled
SELinuxfs mount:                /sys/fs/selinux
SELinux root directory:         /etc/selinux
Loaded policy name:             targeted
Current mode:                   enforcing
Mode from config file:          enforcing
Policy MLS status:              enabled
Policy deny_unknown status:     allowed
Max kernel policy version:      28

To get exact zabbix IDs that needs to be added as permissive for Selinux you can use ps -eZ like so:

[root@centos ~ ]# ps -eZ |grep -i zabbix
system_u:system_r:zabbix_agent_t:s0 1149 ?     00:00:00 zabbix_agentd
system_u:system_r:zabbix_agent_t:s0 1150 ?     00:04:28 zabbix_agentd
system_u:system_r:zabbix_agent_t:s0 1151 ?     00:00:00 zabbix_agentd
system_u:system_r:zabbix_agent_t:s0 1152 ?     00:00:00 zabbix_agentd
system_u:system_r:zabbix_agent_t:s0 1153 ?     00:00:00 zabbix_agentd
system_u:system_r:zabbix_agent_t:s0 1154 ?     02:21:46 zabbix_agentd

As you can see zabbix is enabled and hence selinux enforcing mode is preventing zabbix client / server to operate and communicate normally, hence to make it work we need to change zabbix agent and zabbix proxy to permissive mode.

Setting selinux for zabbix agent and zabbix proxy to permissive mode

If you don't have them installed you might neet the setroubleshoot setools, setools-console and policycoreutils-python rpms packs (if you have them installed skip this step).

[root@centos ~ ]# yum install setroubleshoot.x86_64 setools.x86_64 setools-console.x86_64 policycoreutils-python.x86_64

Then to add zabbix service to become permissive either run

[root@centos ~ ]# semanage permissive –add zabbix_t

[root@centos ~ ]# semanage permissive -a zabbix_agent_t


In some cases you might also need in case if just adding the permissive for zabbix_agent_t try also :

setsebool -P zabbix_can_network=1

Next try to start zabbox-proxy and zabbix-agent systemd services 

[root@centos ~ ]# systemctl start zabbix-proxy.service

[root@centos ~ ]# systemctl start zabbix-agent.service

Hopefully all should report fine with the service checking the status should show you something like:

[root@centos ~ ]# systemctl status zabbix-agent
● zabbix-agent.service – Zabbix Agent
   Loaded: loaded (/usr/lib/systemd/system/zabbix-agent.service; enabled; vendor preset: disabled)
   Active: active (running) since Thu 2021-06-24 07:47:42 CEST; 1 weeks 5 days ago
 Main PID: 1149 (zabbix_agentd)
   CGroup: /system.slice/zabbix-agent.service
           ├─1149 /usr/sbin/zabbix_agentd -c /etc/zabbix/zabbix_agentd.conf
           ├─1150 /usr/sbin/zabbix_agentd: collector [idle 1 sec]
           ├─1151 /usr/sbin/zabbix_agentd: listener #1 [waiting for connection]
           ├─1152 /usr/sbin/zabbix_agentd: listener #2 [waiting for connection]
           ├─1153 /usr/sbin/zabbix_agentd: listener #3 [waiting for connection]
           └─1154 /usr/sbin/zabbix_agentd: active checks #1 [idle 1 sec]

Check the Logs finally to make sure all is fine with zabbix being allowed by selinux.

[root@centos ~ ]# grep zabbix_proxy /var/log/audit/audit.log

[root@centos ~ ]# tail -n 100 /var/log/zabbix/zabbix_agentd.log


If no errors are in and you receive and you can visualize the usual zabbix collected CPU / Memory / Disk etc. values you're good, Enjoy ! 🙂

How to install and use memcached on Debian GNU / Linux to share php sessions between DNS round robined Apache webservers

Monday, November 9th, 2020

apache-load-balancing-keep-persistent-php-sessions-memcached-logo

Recently I had to come up with a solution to make A bunch of websites hosted on a machine to be high available. For the task haproxy is one of logical options to use. However as I didn't wanted to set new IP addresses and play around to build a cluster. I decided the much more simplistic approach to use 2 separate Machines each running Up-to-date same version of Apache Webserver as front end and using a shared data running on Master-to-Master MySQL replication database as a backend. For the load balancing itself I've used a simple 2 multiple DNS 'A' Active records, configured via the Bind DNS name server an Round Robin DNS load balancing for each of the domains, to make them point to the the 2 Internet IP addresses (XXX.XXX.XXX.4 and YYY.YYY.YYY.5) each configured on the 2 Linux servers eth0.

So far so good, this setup worked but immediately, I've run another issue as I found out the WordPress and Joomla based websites's PHP sessions are lost, as the connectivity by the remote client browser reaches one time on XXX…4 and one time on YYY…4 configured listerner on TCP port 80 and TCP p. 443. In other words if request comes up to Front end Apache worker webserver 1 with opened channel data is sent back to Client Browser and the next request is sent due to the other IP resolved by the DNS server to come to Apache worker webserver 2 of course webserver 2 has no idea about this previous session data and it gets confused and returns soemething like a 404 or 500 or any other error … not exciting really huh …

I've thought about work around and as I didn't wanted to involve thirty party stuff as Privoxy / Squid  / Varnish / Polipo etc. just as that would add extra complexity as if I choose to use haproxy from the beginning, after short investigation came to a reason to use memcached as a central PHP sessions storage.

php-memcached-apache-workers-webbrowser-keep-sessions-diagram
 

Why I choose memcached ?


Well it is relatively easy to configure, it doesn't come with mambo-jambo unreadable over-complicated configuration and the time to configure everything is really little as well as the configuration is much straight forward, plus I don't need to occupy more IP addresses and I don't need to do any changes to the already running 2 WebServers on 2 separate Linux hosts configured to be reachable from the Internet.
Of course using memcached is not a rock solid and not the best solution out there, as there is risk that if a memcached dies out for some reason all sessions stored in are lost as they're stored only in volatile memory, as well as there is a drawback that if a communication was done via one of the 2 webservers and one of them goes down sessions that were known by one of Apache's workers disappears.

So let me proceed and explain you the steps to take to configure memcached as a central session storage system.
 

1. Install memcached and php-memcached packages


To enable support for memcached besides installing memcached daemon, you need to have the php-memcached which will provide the memcached.so used by Apache loaded php script interpretter module.

On a Debian / Ubuntu and other deb based GNU / Linux it should be:

webserver1:~# apt-get install memcached php-memcached

TO use php-memcached I assume Apache and its support for PHP is already installed with lets say:
 

webserver1:~# apt-get install php libapache2-mod-php php-mcrypt


On CentOS / RHEL / Fedora Linux it is a little bit more complicated as you'll need to install php-pear and compile the module with pecl

 

[root@centos ~]# yum install php-pear

[root@centos ~]# yum install php-pecl-memcache


Compile memcache

[root@centos ~]# pecl install memcache

 

2. Test if memcached is properly loaded in PHP


Once installed lets check if memcached service is running and memcached support is loaded as module into PHP core.

 

webserver1:~# ps -efa  | egrep memcached
nobody   14443     1  0 Oct23 ?        00:04:34 /usr/bin/memcached -v -m 64 -p 11211 -u nobody -l 127.0.0.1 -l 192.168.0.1

root@webserver1:/# php -m | egrep memcache
memcached


To get a bit more verbose information on memcache version and few of memcached variable settings:

root@webserver1:/# php -i |grep -i memcache
/etc/php/7.4/cli/conf.d/25-memcached.ini
memcached
memcached support => enabled
libmemcached version => 1.0.18
memcached.compression_factor => 1.3 => 1.3
memcached.compression_threshold => 2000 => 2000
memcached.compression_type => fastlz => fastlz
memcached.default_binary_protocol => Off => Off
memcached.default_connect_timeout => 0 => 0
memcached.default_consistent_hash => Off => Off
memcached.serializer => php => php
memcached.sess_binary_protocol => On => On
memcached.sess_connect_timeout => 0 => 0
memcached.sess_consistent_hash => On => On
memcached.sess_consistent_hash_type => ketama => ketama
memcached.sess_lock_expire => 0 => 0
memcached.sess_lock_max_wait => not set => not set
memcached.sess_lock_retries => 5 => 5
memcached.sess_lock_wait => not set => not set
memcached.sess_lock_wait_max => 150 => 150
memcached.sess_lock_wait_min => 150 => 150
memcached.sess_locking => On => On
memcached.sess_number_of_replicas => 0 => 0
memcached.sess_persistent => Off => Off
memcached.sess_prefix => memc.sess.key. => memc.sess.key.
memcached.sess_randomize_replica_read => Off => Off
memcached.sess_remove_failed_servers => Off => Off
memcached.sess_sasl_password => no value => no value
memcached.sess_sasl_username => no value => no value
memcached.sess_server_failure_limit => 0 => 0
memcached.store_retry_count => 2 => 2
Registered save handlers => files user memcached


Make sure /etc/default/memcached (on Debian is enabled) on CentOS / RHELs this should be /etc/sysconfig/memcached

webserver1:~# cat default/memcached 
# Set this to no to disable memcached.
ENABLE_MEMCACHED=yes

As assured on server1 memcached + php is ready to be used, next login to Linux server 2 and repeat the same steps install memcached and the module and check it is showing as loaded.

Next place under some of your webservers hosted websites under check_memcached.php below PHP code
 

<?php
if (class_exists('Memcache')) {
    $server = 'localhost';
    if (!empty($_REQUEST[‘server’])) {
        $server = $_REQUEST[‘server’];
    }
    $memcache = new Memcache;
    $isMemcacheAvailable = @$memcache->connect($server);

    if ($isMemcacheAvailable) {
        $aData = $memcache->get('data');
        echo '<pre>';
        if ($aData) {
            echo '<h2>Data from Cache:</h2>';
            print_r($aData);
        } else {
            $aData = array(
                'me' => 'you',
                'us' => 'them',
            );
            echo '<h2>Fresh Data:</h2>';
            print_r($aData);
            $memcache->set('data', $aData, 0, 300);
        }
        $aData = $memcache->get('data');
        if ($aData) {
            echo '<h3>Memcache seem to be working fine!</h3>';
        } else {
            echo '<h3>Memcache DOES NOT seem to be working!</h3>';
        }
        echo '</pre>';
    }
}

if (!$isMemcacheAvailable) {
    echo 'Memcache not available';
}

?>


Launch in a browser https://your-dns-round-robined-domain.com/check_memcached.php, the browser output should be as on below screenshot:

check_memcached-php-script-website-screenshot

3. Configure memcached daemons on both nodes

All we need to set up is the listen IPv4 addresses

On Host Webserver1
You should have in /etc/memcached.conf

-l 127.0.0.1
-l 192.168.0.1

webserver1:~# grep -Ei '\-l' /etc/memcached.conf 
-l 127.0.0.1
-l 192.168.0.1


On Host Webserver2

-l 127.0.0.1
-l 192.168.0.200

 

webserver2:~# grep -Ei '\-l' /etc/memcached.conf
-l 127.0.0.1
-l 192.168.0.200

 

4. Configure memcached in php.ini

Edit config /etc/php.ini (on CentOS / RHEL) or on Debians / Ubuntus etc. modify /etc/php/*/apache2/php.ini (where depending on the PHP version you're using your php location could be different lets say /etc/php/5.6/apache2/php.ini):

If you wonder where is the php.ini config in your case you can usually get it from the php cli:

webserver1:~# php -i | grep "php.ini"
Configuration File (php.ini) Path => /etc/php/7.4/cli
Loaded Configuration File => /etc/php/7.4/cli/php.ini

 

! Note: That on on PHP-FPM installations (where FastCGI Process Manager) is handling PHP requests,path would be rather something like:
 

/etc/php5/fpm/php.ini

in php.ini you need to change as minimum below 2 variables
 

session.save_handler =
session.save_path =


By default session.save_path would be set to lets say session.save_path = "

/var/lib/php7/sessions"


To make php use a 2 central configured memcached servers on webserver1 and webserver2 or even more memcached configured machines set it to look as so:

session.save_path="192.168.0.200:11211, 192.168.0.1:11211"


Also modify set

session.save_handler = memcache


Overall changed php.ini configuration on Linux machine 1 ( webserver1 ) and Linux machine 2 ( webserver2 ) should be:

session.save_handler = memcache
session.save_path="192.168.0.200:11211, 192.168.0.1:11211"

 

Below is approximately how it should look on both :

webserver1: ~# grep -Ei 'session.save_handler|session.save_path' /etc/php.ini
;; session.save_handler = files
session.save_handler = memcache
;     session.save_path = "N;/path"
;     session.save_path = "N;MODE;/path"
;session.save_path = "/var/lib/php7/sessions"
session.save_path="192.168.0.200:11211, 192.168.0.1:11211"
;       (see session.save_path above), then garbage collection does *not*
 

 

webserver2: ~# grep -Ei 'session.save_handler|session.save_path' /etc/php.ini
;; session.save_handler = files
session.save_handler = memcache
;     session.save_path = "N;/path"
;     session.save_path = "N;MODE;/path"
;session.save_path = "/var/lib/php7/sessions"
session.save_path="192.168.0.200:11211, 192.168.0.1:11211"
;       (see session.save_path above), then garbage collection does *not*


As you can see I have configured memcached on webserver1 to listen on internal local LAN IP 192.168.0.200 and on Local LAN eth iface 192.168.0.1 on TCP port 11211 (this is the default memcached connections listen port), for security or obscurity reasons you might choose another empty one. Make sure to also set the proper firewalling to that port, the best is to enable connections only between 192.168.0.200 and 192.168.0.1 on each of machine 1 and machine 2.

loadbalancing2-php-sessions-scheme-explained
 

5. Enable Memcached for session redundancy


Next step is to configure memcached to allow failover (e.g. use both memcached on 2 linux hosts) and configure session redundancy.
Configure /etc/php/7.3/mods-available/memcache.ini or /etc/php5/mods-available/memcache.ini or respectively to the right location depending on the PHP installed and used webservers version.
 

webserver1 :~#  vim /etc/php/7.3/mods-available/memcache.ini

; configuration for php memcached module
; priority=20
; settings to write sessions to both servers and have fail over
memcache.hash_strategy=consistent
memcache.allow_failover=1
memcache.session_redundancy=3
extension=memcached.so

 

webserver2 :~# vim /etc/php/7.3/mods-available/memcache.ini

; configuration for php memcached module
; priority=20
; settings to write sessions to both servers and have fail over
memcache.hash_strategy=consistent
memcache.allow_failover=1
memcache.session_redundancy=3
extension=memcached.so

 

memcache.session_redundancy directive must be equal to the number of memcached servers + 1 for the session information to be replicated to all the servers. This is due to a bug in PHP.
I have only 2 memcached configured that's why I set it to 3.
 

6. Restart Apache Webservers

Restart on both machines webserver1 and webserver2 Apache to make php load memcached.so
 

webserver1:~# systemctl restart httpd

webserver2:~# systemctl restart httpd

 

7. Restart memcached on machine 1 and 2

 

webserver1 :~# systemctl restart memcached

webserver2 :~# systemctl restart memcached

 

8. Test php sessions are working as expected with a php script

Copy to both website locations to accessible URL a file test_sessions.php:
 

<?php  
session_start();

if(isset($_SESSION[‘georgi’]))
{
echo "Sessions is ".$_SESSION[‘georgi’]."!\n";
}
else
{
echo "Session ID: ".session_id()."\n";
echo "Session Name: ".session_name()."\n";
echo "Setting 'georgi' to 'cool'\n";
$_SESSION[‘georgi’]='cool';
}
?>

 

Now run the test to see PHP sessions are kept persistently:
 

hipo@jeremiah:~/Desktop $ curl -vL -s https://www.pc-freak.net/session.php 2>&1 | grep 'Set-Cookie:'
< Set-Cookie: PHPSESSID=micir464cplbdfpo36n3qi9hd3; expires=Tue, 10-Nov-2020 12:14:32 GMT; Max-Age=86400; path=/

hipo@jeremiah:~/Desktop $ curl -L –cookie "PHPSESSID=micir464cplbdfpo36n3qi9hd3" http://83.228.93.76/session.php http://213.91.190.233/session.php
Session is cool!
Session is cool!

 

Copy to the locations that is resolving to both DNS servers some sample php script such as sessions_test.php  with below content:

<?php
    header('Content-Type: text/plain');
    session_start();
    if(!isset($_SESSION[‘visit’]))
    {
        echo "This is the first time you're visiting this server\n";
        $_SESSION[‘visit’] = 0;
    }
    else
            echo "Your number of visits: ".$_SESSION[‘visit’] . "\n";

    $_SESSION[‘visit’]++;

    echo "Server IP: ".$_SERVER[‘SERVER_ADDR’] . "\n";
    echo "Client IP: ".$_SERVER[‘REMOTE_ADDR’] . "\n";
    print_r($_COOKIE);
?>

Test in a Web Opera / Firefox / Chrome browser.

You should get an output in the browser similar to:
 

Your number of visits: 15
Server IP: 83.228.93.76
Client IP: 91.92.15.51
Array
(
    [_ga] => GA1.2.651288003.1538922937
    [__utma] => 238407297.651288003.1538922937.1601730730.1601759984.45
    [__utmz] => 238407297.1571087583.28.4.utmcsr=google|utmccn=(organic)|utmcmd=organic|utmctr=(not provided)
    [shellInABox] => 467306938:1110101010
    [fpestid] => EzkIzv_9OWmR9PxhUM8HEKoV3fbOri1iAiHesU7T4Pso4Mbi7Gtt9L1vlChtkli5GVDKtg
    [__gads] => ID=8a1e445d88889784-22302f2c01b9005b:T=1603219663:RT=1603219663:S=ALNI_MZ6L4IIaIBcwaeCk_KNwmL3df3Z2g
    [PHPSESSID] => mgpk1ivhvfc2d0daq08e0p0ec5
)

If you want to test php sessions are working with text browser or from another external script for automation use something as below PHP code:
 

<?php
// save as "session_test.php" inside your webspace  
ini_set('display_errors', 'On');
error_reporting(6143);

session_start();

$sessionSavePath = ini_get('session.save_path');

echo '<br><div style="background:#def;padding:6px">'
   , 'If a session could be started successfully <b>you should'
   , ' not see any Warning(s)</b>, otherwise check the path/folder'
   , ' mentioned in the warning(s) for proper access rights.<hr>';
echo "WebServer IP:" . $_SERVER[‘SERVER_ADDR’] . "\n<br />";
if (empty($sessionSavePath)) {
    echo 'A "<b>session.save_path</b>" is currently',
         ' <b>not</b> set.<br>Normally "<b>';
    if (isset($_ENV[‘TMP’])) {
        echo  $_ENV[‘TMP’], ‘” ($_ENV[“TMP”]) ';
    } else {
        echo '/tmp</b>" or "<b>C:\tmp</b>" (or whatever',
             ' the OS default "TMP" folder is set to)';
    }    
    echo ' is used in this case.';
} else {
    echo 'The current "session.save_path" is "<b>',
         $sessionSavePath, '</b>".';
}

echo '<br>Session file name: "<b>sess_', session_id()
   , '</b>".</div><br>';
?>

You can download the test_php_sessions.php script here.

To test with lynx:

hipo@jeremiah:~/Desktop $ lynx -source 'https://www.pc-freak.net/test_php_sessions.php'
<br><div style="background:#def;padding:6px">If a session could be started successfully <b>you should not see any Warning(s)</b>, otherwise check the path/folder mentioned in the warning(s) for proper access rights.<hr>WebServer IP:83.228.93.76
<br />The current "session.save_path" is "<b>tcp://192.168.0.200:11211, tcp://192.168.0.1:11211</b>".<br>Session file name: "<b>sess_5h18f809b88isf8vileudgrl40</b>".</div><br>

How to install Toshiba Satellite L40 B14 Wireless Adapter ( ID 0bda:8197 Realtek Semiconductor Corp. RTL8187B) on Ubuntu and Debian Linux

Thursday, April 28th, 2011

https://www.pc-freak.net/images/toshiba-satellite-l40

How to install Toshiba L40 B14 Wireless Adapter ( ID 0bda:8197 Realtek Semiconductor Corp. RTL8187B) on Ubuntu and Debian Linux
I've been struggling for more than 10 hours to fix up issues on a Ubuntu Maverick-Meerkaat with a rtl8187B Wireless Adapter

The RTL8187B almost drove me mad. I could see the wlan0 which meant the kernel is detecting the device, I could even bring it up with ifconfig wlan0 up , however when I tried it in gnome's network-manager or wicd the wireless networks were not showing up.

Trying to scan for networks using the commands:


ubuntu:~# iwlist wlan0 scan

was also unsuccesful, trying to bring up and down the wireless wlan0 interface with:


ubuntu:~# iwconfig wlan0 up

or


ubuntu:~# iwconfig wlan0 down

Both returned the error:
iwconfig: unknown command "up" and iwconfig: unknown command "down"

Running simply iwconfig was properly returning information about my Wireless Interface wlan0 :


wlan0 IEEE 802.11bg ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=20 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:off

The exact information I could get about the wireless device was via the command:


ubuntu:~# lsusb | grep realtek
Bus 001 Device 002: ID 0bda:8197 Realtek Semiconductor Corp. RTL8187B Wireless Adapter

Trying manually to scan for wireless networks from console or gnome-terminal with command returned also the below weird results:


ubuntu:~# iwconfig wlan0 scan
iwconfig: unknown command "scan"

More oddly tunning wlan0 interface with commands like:


ubuntu:~# iwconfig wlan0 mode managed
ubuntu:~# iwconfig wlan0 essid ESSID
ubuntu:~# iwconfig wlan0 rate 11M

were succesful …

I read a bunch of documentation online concerning the wireless card troubles on Ubuntu, Gentoo, Debian etc.

Just few of all the resources I've read and tried are:

http://rtl-wifi.sourceforge.net/wiki/Main_Page (Returning empty page already a lot resource)
http://rtl8187b.sourceforge.net (A fork of rtl-wifi.sourceforge.net which is still available though it was not usable)

Some of the other resources which most of the people recommended as a way to properly install the RTL8187B wireless driver on linux was located on the website:

http://datanorth.net/~cuervo/rtl8187b/ (Trying to access this page returned a 404 error e.g. this page is no-longer usable)

I found even a webpage in Ubuntu Help which claimed to explain how to properly install and configure the RTL8187B wireless driver on which is below:

https://help.ubuntu.com/community/WifiDocs/Device/RealtekRTL8187b

Even the Ubuntu help instructions were pointing me to the broken cuervo's website URL

Anyways I was able to find the rtl8187b-modified-dist.tar.gz online and made a mirror of rtl8187b-modified-dist.tar.gz which you can download here

Another rtl8187b driver I found was on a toshiba website made especailly for the wireless linux drivers:

http://linux.toshiba-dme.co.jp/linux/eng/pc/sat_PSPD0_report.htm

The questionable file which was claimed to properly be able to make the Realtek Semiconductor Corp. RTL8187B Wireless Adapter to work out was called rl8187b-modified-804.tar.gz.
I've made a mirror of rtl8187b-modified-804.tar.gz is here

None of the driver archives rtl8187b-modified-dist.tar.gz and rl8187b-modified-804.tar.gz that was supposed to make the Toshiba L40 realtek wireless to work out, after compiling and installing the drivers from source worked out …

Both archives produced plenty of error messages and it seems on newer kernels like the one on this notebook:

Linux zlatina 2.6.35-28-generic #50-Ubuntu SMP Fri Mar 18 19:00:26 UTC 2011 i686 GNU/Linux, they're no longer usable.

The compile errors I got when I tried compiling the rtl8187b driver provided by the archive rtl8187b-modified-dist were:


root@ubuntu:/home/zlatina/rtl8187b-modified# sh makedrv
rm -fr *.mod.c *.mod *.o .*.cmd *.mod.* *.ko *.o *~
make -C /lib/modules/2.6.35-28-generic/build M=/home/zlatina/rtl8187b-modified/ieee80211 CC=gcc modules
make[1]: Entering directory `/usr/src/linux-headers-2.6.35-28-generic'
scripts/Makefile.build:49: *** CFLAGS was changed in "/home/zlatina/rtl8187b-modified/ieee80211/Makefile". Fix it to use EXTRA_CFLAGS. Stop.
make[1]: *** [_module_/home/zlatina/rtl8187b-modified/ieee80211] Error 2
make[1]: Leaving directory `/usr/src/linux-headers-2.6.35-28-generic'
make: *** [modules] Error 2
rm -fr *.mod.c *.mod *.o .*.cmd *.ko *~
make -C /lib/modules/2.6.35-28-generic/build M=/home/zlatina/rtl8187b-modified/rtl8187 CC=gcc modules
make[1]: Entering directory `/usr/src/linux-headers-2.6.35-28-generic'
scripts/Makefile.build:49: *** CFLAGS was changed in "/home/zlatina/rtl8187b-modified/rtl8187/Makefile". Fix it to use EXTRA_CFLAGS. Stop.
make[1]: *** [_module_/home/zlatina/rtl8187b-modified/rtl8187] Error 2
make[1]: Leaving directory `/usr/src/linux-headers-2.6.35-28-generic'
make: *** [modules] Error 2
root@ubuntu:/home/zlatina/rtl8187b-modified#

Another driver I tried which was found on aircrack-ng.org's website was rtl8187_linux_26.1010.zip

Here are the error messages I experienced while I tried to compile the realtek wireless driver from the archive rtl8187_linux_26.1010.0622.2006


compilation terminated.
make[2]: *** [/home/zlatina/rtl8187_linux_26.1010.0622.2006/beta-8187/r8187_core.o] Error 1
make[1]: *** [_module_/home/zlatina/rtl8187_linux_26.1010.0622.2006/beta-8187] Error 2
make[1]: Leaving directory `/usr/src/linux-headers-2.6.35-28-generic'
make: *** [modules] Error 2
make: *** [modules] Error 2

I tried a number of fix ups hoping to solve the compile error messages, but my efforts were useless, as it seems many things has changed in newer Ubuntu versions and they could no longer be compiled.

As I realized I couldn't make the native drivers provided by the above sources compile, I decided to give a try to the Windows drivers for Realtek 8187B with ndiswrapper, a link for download of Realtek 8187B (RTL8187B_XP_6.1163.0331.2010_Win7_62.1182.0331.2010_UI_1.00.0179 is found here

I untarred the
RTL8187B_XP driver
and used ndiswrapper to load driver like so:


root@ubuntu:~# tar -zxvf
RTL8187B_XP_6.1163.0331.2010_Win7_....L.tar.gz
root@ubuntu:/home/zlatina/RTL8187B#
root@ubuntu:/home/zlatina/RTL8187B# cd Driver/WinXP
root@ubuntu:/home/zlatina/RTL8187B/Driver/WinXP# ndiswrapper -i net8187b.inf

In order to test the RTL8178B Windows driver I used:


root@ubuntu:~# ndiswrapper -l
net8187b : driver installed
device (0BDA:8197) present (alternate driver: rtl8187)

To finally load the Windows XP RTL8187B driver on the Ubuntu I used again ndiswrapper:


root@ubuntu:~# ndiswrapper -m

Further on I used the ndisgtk graphical ndiswrapper interface to once again test if the Windows driver is working on the Ubuntu and it seemed like it is working, however still my wicd was unable to find any wireless network ….

There were many online documentation which claimed that the driver for rtl8187b works out of the box on newer kernel releases (kernel versions > 2.6.24)

Finally I found out there is a driver which is a default one with the Ubuntu e.g. rtl8187.ko , I proceeded and loaded the module:


root@ubuntu:~# modprobe rtl8187

I also decided to check out if the hardware switch button of the Toshiba Satellite L40 notebook is not switched off and guess what ?! The Wireless ON/OFF button was switched OFF!!! OMG …

I switched on the button and wicd immediately started showing up the wireless networks …

To make the rtl8187 module load on Ubuntu boot up, I had to issue the command:


root@ubuntu:~# echo 'rtl8187' >> /etc/modules

Voila after all this struggle the wireless card is working now, it's sad I had to loose about 10 hours of time until I come with the simple solution of using the default provided ubuntu driver rtl8187 , what is strange is how comes that it does not load up automatically.

Thanks God it works now.

How to change / reset lost or forgot TightVNC administrator password

Tuesday, May 24th, 2011

how-to-change-reset-lost-TightVNC-administrator-password

I have installed TightVNC to a Windows host just a few weeks ago in order to be able to manage remotely a Windows host and forgot to write down the administrator password 🙂 (stoopid!)

I had to explain to a friend remotely how to change the TightVNC admin password and it was a complete nightmare!

Shortly here is the exact menus one who wants to reset the password of a TigthVNC server after forgotten:

Start -> All Programs -> TightVNC
-> TightVNC Server (Service Mode) ->
TightVNC Service - Offline Configuration.

In the configuration dialog to popup there are the Server and Administration tabs through which a new password can be set.

After the password is change either a restart of the TightVNC server is necessery or a restart of the Windows PC.

Still Here

Wednesday, January 17th, 2007

Aloha. Still here. Two days ago I ran Heroes 3 under my FreeBSD box successfully, there was a terrible bug in fullscreen mode which needed fix I’ve used the loki’s site patch to patch the heroes 3 start binary with xdelta. The loki installer was a terrible pain in the ass I used my l337test sk!llZ :} to be able to patch the binary by hand. About the last post yes I was desperate still not good still living. Today I was on exam again a failure probably, nothing new.

As I often used to say in the fast if something starts bad then it overs bad too. See my life show this very well. I’m suffering terrible and still waiting for something to set me free to happen. What would be the turning point? Will there be turning point at all? No idea. If God is such good and powerful as he said in the bible and his promises are true then he will deliver me and set me free on a good ground. Still hoping … Prodigy — Speedway, else the earth is probably his favourite experiment.

How to make GNOME 3 Desktop icons to work as in GNOME 2 on Debian GNU / Linux

Saturday, February 4th, 2012

If you're using Debian GNU/Linux wheezy/sid, you have already figured out GNOME3 settings to start GNOME in Classic mode (like in GNOME 2), starts gnome in a mode where the desktop is not showing the usual Computer, Home, Trash etc.

Besides that in that strange back-compitability Classic GNOME mode its impossible to add any program as a link in desktop like in the good old GNOME 2.

Thanksfully this abusive behaviour of the backwards compitability mode is easily fixable by two simple steps, here they are:

1. Install gnome-tweak-tool – (Tool to adjust advanced configuration settings for GNOME

root@debian:~# apt-get install gnome-tweak-tool

2. Start gnome-tweak tool

Press ALT+F2 and run gnome-tweak-tool or run it via xterm / gnome-terminal:

moonman@Moon:~$ gnome-tweak-tool

Change in Desktop, Have file manager handle the desktop the settings to ON

gnome-tweek-tool Debian GNU Linux wheezy sid screenshot

gnome-tweak-tool Debian wheezy/Sid GNU Linux screenshot handle desktop on

Once the Screenshot Handle Desktop is set to ON, further drag and dropping any application to the Desktop will be working.
Something really irritating is that launching applications in GNOME 3 does not work properly if you just press ALT+F2 and type in lets say gnome-terminal , to work around this weirdity you will have to install gnome-shell package.

How ot fix Widgets drag and drop not working on WordPress

Thursday, July 14th, 2011

how to fix WordPress widgets missing drag and drop bug

My WordPress blog had an odd problem, all on the blog, worked just fine except the Widgets add new widget drag and drop functionality.
As there was new version of wordpress available I tried updating but this fixed the missing drag and drop widget functionality neither, so finally after a bit of googling and experimentation to follow suggested fixes like using the enable Accessiblity Mode button on top Widgets.Thus the common suggested fix that worked for most of the people who stumbled upon this annoying wordpress bug was to simply nagivate to:

Appearance -> Widgets -> Screen Options -> Enable Accessibility Mode As for me pressing over the Screen Options was impossible (nothing happened when I pressed over it), finally I’ve found a hack 😉

The hack is quite simple, all I had to do is just pass a variable ?widgets-access=on to the widget.php php script
Therefore the fix to the problem was as follows http://blog.mysite.com/wp-admin/widgets.php?widgets-access=on

And done, FIXED! 😉

Cleaning Packard Bell Hera GL laptop running Windows XP from Viruses and Spyware (Viruses / Spyware which can make CD drive and Wireless seem unworking)

Tuesday, December 13th, 2011

Packard Bell Hera GL Fixing Broken RaLink Wireless

Yesterday, one (girl)friend of mine brought me one Packard Bell notebook, which had a 2 years old Windows installed on it.
As one can imagine Windows XP on it is full of Spyware and Viruses. Besides the software problems the notebook had some hardware problems with the CD / DVD which is not reading CD / DVDs at all.

Initially I thought, the CD unable to read problems are caused by the infected Windows, however even restarting the PC with a bootable Hirens BootCD and a Whoppix liveCD and trying to boot from it failed this convinced me its a CD / DVD combo drive hardware failure.

By the way, I’ve just recently found out about Nixory – Is a nice Free Software Open Source AntiSpyware tool for Firefox, IE and Chrome.

Nixory Windows XP Screenshot

I hope it will get a sharp development and soon, when some friend asks me to fix his stupid non free-Windows PC, I would not have to use a trial version of Malware Bytes but directly use only Nixory

Anyways after using Nixory, MalwareBytes and Avira and thoroughfully scanned the system in Safe Mode and found and deleted some 15 Spyware / Viruses and tampered a bit with the Wireless Driver settings all the notebook devices started working fine again.

The wireless had also one really odd problem on this Packard BellHera GL, even though the notebook wireless antenna was capable of detecting all the wireless networks it couldn’t properly connect to any of it but failed to get proper IP addresses.
Partially the unable to grab an IP via wireless router dhcp server got fixed by using the Wireless restart Button (located on the Notebook corpus).
However even after cleaning up the Virus and Spyware the Wireless Networks connectivity problems on this Packard Bell continued, until I changed also few settings in the Control PanelI never thought Viruses / Spyware infected can have some bad impact on Wireless Card and CD drive make them unsusable though they showed like working correctly in Windows Control Panel -> System ??

In the meantime I reinstalled the Wireless Driver for the notebook, the Wireless card on the notebook was showing up itself under the name of Ralink 802.11n Wireless Lan Card in Windows Device Manager

After re-installing the wireless driver I had to also change few settings for the Wireless Network Connection using the menus Properties -> Configure -> Extended; therein everywhere for each Value I make it be Enable and for Power Saving Mode , I’ve choose the Value option of CAM

After a system reboot, everything started working finally fine. One last thing to add is that before I fixed the Ralink wireless to work under Windows, I tried to use a Bootable Linux LiveCD but even there the wireless was failing to connect to the wireless networks (maybe this shit wireless device has some issues with its Linux drivers).