CentOS


Building wireshark-2.4.2 on CentOS 7 (64bit)

Recently we were trying to compile WireShark from source on a CentOS 7 (64bit) with GTK3 disabled (./configure --disable-gtk3;).

As seen in the truncated logs below we got some errors.
To resolve them we had to install a few packages using yum.
Specifically, our solution involved the installation of the following:

sudo yum install libgcrypt-devel qt5-qttools-devel libpcap-devel -y;

Truncated logs:

...
checking for libgcrypt-config... no
checking for LIBGCRYPT - version >= 1.4.2... no
configure: error: libgcrypt not found; install libgcrypt-devel package for your system
libgcrypt-devel.i686 libgcrypt-devel.x86_64 
[[email protected] wireshark-2.4.2]$ sudo yum install libgcrypt-devel -y

checking for lrelease-qt5... no
checking for lrelease... no
configure: error: I couldn't find lrelease-qt5 or lrelease; make sure it's installed and in your path
[[email protected] wireshark-2.4.2]$ sudo yum install qt5-qttools-devel

checking whether to use libpcap for packet capture... yes
checking for pcap-config... no
checking for extraneous pcap header directories... not found
checking pcap.h usability... no
checking pcap.h presence... no
checking for pcap.h... no
configure: error: Header file pcap.h not found; if you installed libpcap
from source, did you also do "make install-incl", and if you installed a
binary package of libpcap, is there also a developer's package of libpcap,
and did you also install that package?
[[email protected] wireshark-2.4.2]$ sudo yum install libpcap-devel

[[email protected] wireshark-2.4.2]$ ./configure --disable-gtk3

 

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CentOS 7: C++: static linking cannot find -lstdc++ -lm and -lc

Recently, we were trying to compile a C++ application with the following compilation command on a CentOS 7 64bit :

g++ -static -O2 -lm -Wall -Wno-unused-result -std=c++11 -DCS_ACADEMY -DONLINE_JUDGE 510152025.cpp -o 510152025;

unfortunately, we got the following errors:

 /usr/bin/ld: cannot find -lstdc++
 /usr/bin/ld: cannot find -lm
 /usr/bin/ld: cannot find -lc
 collect2: error: ld returned 1 exit status

To resolve the issues, we performed the following installations to install the static versions of the glibc and libstdc libraries:

sudo yum install glibc-static libstdc++-static -y;

 


CentOS 7: Setup a DHCP server and provide specific IP based on MAC address

Step 1: Install DHCP service

We installed the Dynamic host configuration protocol software (DHCP service) using the command:

yum install dhcp;

The dhcp package provides the ISC DHCP service and relay agent.

Step 2: Configure the DHCP service

Afterwards, we created the file /etc/dhcp/dhcpd.conf using the following content:

subnet 192.168.0.0 netmask 255.255.255.0 {
 option routers                  192.168.0.254;
 option subnet-mask              255.255.255.0;
 option domain-name              "bytefreaks.net";
 option domain-name-servers       192.168.0.1;
 option time-offset              -18000;     # Eastern Standard Time
 range 192.168.0.90 192.168.0.99;
}

host coolServer {
 hardware ethernet 0e:e0:4b:b4:28:82;
 fixed-address 192.168.0.80;
}

This configuration allowed us to provide a DHCP service to the network for the subdomain 192.168.0.x with the range [90,99].
Also, we statically defined the IP for our coolServer using a filter based on the MAC address of the machine.
If you do not want to provide any range, only static IPs, then comment out (#) the line that starts with the word range .

Step 3: Start DHCP service

systemctl start dhcpd.service;

Step 4: Check the status of DHCP service

systemctl status dhcpd.service;

It is a good idea to verify that there are no errors, so be sure to check the status of the service.
You can ignore the error that says “you did not define a subnet declaration for all devices” if you do not really need to do it.

Step 5: Permanently enable the DHCP service

systemctl enable dhcpd.service;

Additional:

Disable the DHCP service

systemctl disable dhcpd.service;

Stop the DHCP service

systemctl stop dhcpd.service;


NTFS Support on CentOS 7 1

Solution

sudo yum --enablerepo=extras install epel-release;
sudo yum install ntfs-3g -y;

Background – Explanation of commands

By default, CentOS does not have installed the necessary drivers to mount ntfs drives.

sudo yum --enablerepo=extras install epel-release;

To install them, you need to enable the Extra Packages for Enterprise Linux (EPEL).

Extra Packages for Enterprise Linux (or EPEL) is a Fedora Special Interest Group that creates, maintains, and manages a high quality set of additional packages for Enterprise Linux, including, but not limited to, Red Hat Enterprise Linux (RHEL), CentOS and Scientific Linux (SL), Oracle Linux (OL).

EPEL packages are usually based on their Fedora counterparts and will never conflict with or replace packages in the base Enterprise Linux distributions. EPEL uses much of the same infrastructure as Fedora, including buildsystem, bugzilla instance, updates manager, mirror manager and more.

From: https://fedoraproject.org/wiki/EPEL

You can install EPEL by running yum --enablerepo=extras install epel-release. The epel-release package is included in the CentOS Extras repository that is enabled by default. The package includes gpg keys for package signing and repository information. Installing this package for your Enterprise Linux version should allow you to use normal tools such as yum to install packages and their dependencies.

sudo yum install ntfs-3g -y;

After you’ve enabled the repository, you should be able to install the Linux NTFS userspace driver packaged in ntfs-3g. ntfs-3g is a stable, open source, GPL licensed, POSIX, read/write NTFS driver for Linux and many other operating systems. It provides safe handling of the Windows XP, Windows Server 2003, Windows 2000, Windows Vista, Windows Server 2008 and Windows 7 NTFS file systems. NTFS-3G can create, remove, rename, move files, directories, hard links, and streams; it can read and write normal and transparently compressed files, including streams and sparse files; it can handle special files like symbolic links, devices, and FIFOs, ACL, extended attributes; moreover it provides full file access right and ownership support.

To install it, we used the following command: yum install ntfs-3g -y.


How To Install on GNU/Linux CentOS 7 the LAMP stack (Apache, MySQL, PHP) + phpMyAdmin

Following you will find the commands to perform the installation of the LAMP stack (Apache, MySQL, PHP) and phpMyAdmin on a GNU/Linux CentOS 7.
In this guide we kept the information to the bare minimum about what is what.

Installation

To perform the installation, please execute the following as a user with administrative rights:

#Update your system
sudo yum update -y;
#Install Apache, MariaDB (MySQL), PHP (with MySQL support and phpMyAdmin which is a free software tool written in PHP, intended to handle the administration of MySQL over the Web)
sudo yum install httpd mariadb-server mariadb php php-mysql phpmyadmin -y;
#Start Apache (PHP will start with Apache as module)
sudo systemctl start httpd;
#Enable Apache to start on boot
sudo systemctl enable httpd;
#Start MariaDB(MySQL)
sudo systemctl start mariadb;
#Enable MariaDB(MySQL) to start on boot
sudo systemctl enable mariadb;

Configuration of MariaDB (MySQL)

By now, your system should have all necessary packages installed and the services up and running.
Now it is best to configure your MariaDB (MySQL) in a way to disable some test data and test accounts and assign a password to your root user.
Execute the following to do so:

sudo mysql_secure_installation;

This tool will ask you for your current database root password. Since you just installed MariaDB (MySQL) you should not have one, so leave the field empty and press enter.
We recommend to answer with Y (Yes) in all of the security questions of this tool and set a strong password for your root user.

sudo mysql_secure_installation;

Following is the output we got from this tool:

NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MariaDB
 SERVERS IN PRODUCTION USE!  PLEASE READ EACH STEP CAREFULLY!

In order to log into MariaDB to secure it, we'll need the current
 password for the root user.  If you've just installed MariaDB, and
 you haven't set the root password yet, the password will be blank,
 so you should just press enter here.

Enter current password for root (enter for none):
 OK, successfully used password, moving on...

Setting the root password ensures that nobody can log into the MariaDB
 root user without the proper authorisation.

Set root password? [Y/n] Y
 New password:
 Re-enter new password:
 Password updated successfully!
 Reloading privilege tables..
 ... Success!

By default, a MariaDB installation has an anonymous user, allowing anyone
 to log into MariaDB without having to have a user account created for
 them.  This is intended only for testing, and to make the installation
 go a bit smoother.  You should remove them before moving into a
 production environment.

Remove anonymous users? [Y/n] Y
 ... Success!

Normally, root should only be allowed to connect from 'localhost'.  This
 ensures that someone cannot guess at the root password from the network.

Disallow root login remotely? [Y/n] Y
 ... Success!

By default, MariaDB comes with a database named 'test' that anyone can
 access.  This is also intended only for testing, and should be removed
 before moving into a production environment.

Remove test database and access to it? [Y/n] Y
 - Dropping test database...
 ... Success!
 - Removing privileges on test database...
 ... Success!

Reloading the privilege tables will ensure that all changes made so far
 will take effect immediately.

Reload privilege tables now? [Y/n] Y
 ... Success!

Cleaning up...

All done!  If you've completed all of the above steps, your MariaDB
 installation should now be secure.

Thanks for using MariaDB!

Configuration of the firewall

Executing the following will enable access to your web-server from the network for http and https.

sudo firewall-cmd --permanent --zone=public --add-service=http;
sudo firewall-cmd --permanent --zone=public --add-service=https;
sudo firewall-cmd --reload;

Location of files / Where to upload your website

In CentOS 7, the directory where the website pages are located is at /var/www/html/.
You can place your html and php code there.

Configuration of phpMyAdmin

phpMyAdmin should be available at http://<IP of the web server>/phpmyadmin
The access to phpMyAdmin is controlled by the Apache Virtual Host File for phpMyAdmin that is found here /etc/httpd/conf.d/phpMyAdmin.conf.
By default, this configuration file only allows access to phpMyAdmin from the localhost (127.0.0.1).
In case you want to access it from another machine, you need to modify this file.
Before doing any changes, make a backup of the original file first:

 sudo cp /etc/httpd/conf.d/phpMyAdmin.conf /etc/httpd/conf.d/phpMyAdmin.conf.original;

To enable access only for a specific IP

Edit the Apache Virtual Host File for phpMyAdmin (/etc/httpd/conf.d/phpMyAdmin.conf) and change every reference of 127.0.0.1 with the IP address of the machine you want to give access to.

There should be four lines that you need to change.
In our installation it was the following lines:

  1. 17Require ip 127.0.0.1
  2. 25Allow from 127.0.0.1
  3. 34Require ip 127.0.0.1
  4. 42Allow from 127.0.0.1

Then restart the Apache service to apply the changes:

sudo systemctl restart httpd;

To enable access to any IP

Delete the existing file and create a new one.

sudo rm /etc/httpd/conf.d/phpMyAdmin.conf;
sudo touch /etc/httpd/conf.d/phpMyAdmin.conf;

Using the editor of your choice add the following content and save it:

Alias /phpMyAdmin /usr/share/phpMyAdmin
Alias /phpmyadmin /usr/share/phpMyAdmin

<Directory /usr/share/phpMyAdmin/>
 AllowOverride None
 Options None
 Allow from All
 Require all granted
</Directory>

Then restart the Apache service to apply the changes:

sudo systemctl restart httpd;

Following is the original content of our Apache Virtual Host File for phpMyAdmin (/etc/httpd/conf.d/phpMyAdmin.conf)

phpMyAdmin.conf (compressed) (112 downloads)

$ cat /etc/httpd/conf.d/phpMyAdmin.conf
 # phpMyAdmin - Web based MySQL browser written in php
 #
 # Allows only localhost by default
 #
 # But allowing phpMyAdmin to anyone other than localhost should be considered
 # dangerous unless properly secured by SSL

Alias /phpMyAdmin /usr/share/phpMyAdmin
Alias /phpmyadmin /usr/share/phpMyAdmin

<Directory /usr/share/phpMyAdmin/>
 AddDefaultCharset UTF-8

 <IfModule mod_authz_core.c>
  # Apache 2.4
  <RequireAny>
   Require ip 192.168.0.20
   Require ip ::1
  </RequireAny>
 </IfModule>
 <IfModule !mod_authz_core.c>
  # Apache 2.2
  Order Deny,Allow
  Deny from All
  Allow from 192.168.0.20
  Allow from ::1
  </IfModule>
</Directory>

<Directory /usr/share/phpMyAdmin/setup/>
 <IfModule mod_authz_core.c>
  # Apache 2.4
  <RequireAny>
   Require ip 192.168.0.20
   Require ip ::1
  </RequireAny>
 </IfModule>
 <IfModule !mod_authz_core.c>
  # Apache 2.2
  Order Deny,Allow
  Deny from All
  Allow from 192.168.0.20
  Allow from ::1
 </IfModule>
</Directory>

# These directories do not require access over HTTP - taken from the original
# phpMyAdmin upstream tarball
#
 <Directory /usr/share/phpMyAdmin/libraries/>
  Order Deny,Allow
  Deny from All
  Allow from None
 </Directory>

<Directory /usr/share/phpMyAdmin/setup/lib/>
  Order Deny,Allow
  Deny from All
  Allow from None
</Directory>

<Directory /usr/share/phpMyAdmin/setup/frames/>
 Order Deny,Allow
 Deny from All
 Allow from None
</Directory>

# This configuration prevents mod_security at phpMyAdmin directories from
# filtering SQL etc.  This may break your mod_security implementation.
#
#<IfModule mod_security.c>
#    <Directory /usr/share/phpMyAdmin/>
#        SecRuleInheritance Off
#    </Directory>
#</IfModule>

phpMyAdmin.conf (compressed) (112 downloads)