Friday, March 27, 2009
Traditionally, Unix/Linux/POSIX filenames can be almost any sequence of bytes, and their meaning is unassigned. The only real rules are that "/" is always the directory separator, and that filenames can't contain byte 0 (because this is the terminator). Although this is flexible, this creates many unnecessary problems. In particular, this lack of limitations makes it unnecessarily difficult to write correct programs (enabling many security flaws), makes it impossible to consistently and accurately display filenames, causes portability problems, and confuses users. more....
Monday, January 19, 2009
This tutorial covers TCP/IP networking and system configuration basics. Linux can support multiple network devices. The device names are numbered and begin at zero and count upwards. For example, a computer running two ethernet cards will have two devices labeled /dev/eth0 and /dev/eth1. Linux network configuration, management, monitoring and system tools are covered in this tutorial.
Servers—whether used for testing or production—are primary targets for attackers. By taking the proper steps, you can turn a vulnerable box into a hardened server and help thwart outside attackers. Learn how to secure SSH sessions, configure firewall rules, and set up intrusion detection to alert you to any possible attacks on your GNU/Linux® server. Once you've gained a solid foundation in the basics of securing your server, you can build on this knowledge to further harden your systems.
Saturday, January 03, 2009
This article assumes that you're already familiar with things like building kernels, applying patches and so on. The target audience is the "advanced end user", and also the Debian developers responsible for the packages concerned who I hope will be motivated to incorporate some of this work.
The creation and management of user-space processes in Linux® have many principles in common with UNIX® but also include several unique optimizations specific to Linux. Here, review the life cycle of Linux processes and explore the kernel internals for user process creation, memory management, scheduling, and death. more...