Nov 19

Opening a TUN Device on UNIX

Category: C, Networking, Programming

The TUN/TAP interface under Linux provides user space access to Transport (Ethernet) or Network Layer (IP) traffic by allowing a developer to create a “virtual” interface that can be openend in user space as a file descriptor.
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Nov 17

Open Source Performance Tools

Category: Networking

A lot of performance tools are very web-oriented these days. Here are a list of tools for simulating network traffic conditions and check throughput, delay, jitter, etc.
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Nov 15

Overview of the CCSDS Network Protocols

Category: CCSDS, Networking

The CCSDS standards can be intimidating to the uninitiated, this article covers AOS, TC, COP-1, and other protocols used in space communications, how they interact, and where to find the details.
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Oct 27

RSS and mercurial

Category: Programming

In a surprisingly well-kept secret, HgWeb and HgWebDir support RSS. Details below.
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Oct 25

LDAP, PAM, SSHA, and CRYPT on RHEL 5

Category: Networking

I’m putting this here because it took me two days to figure this out. RHEL 5 (or CentOS 5) has openLDAP broken out of the box. It does not handle SSHA password encryption (the default for openLDAP) properly. If you want openLDAP authentication to work with PAM on CentOs 5.3 you MUST edit the /etc/openldap/slapd.conf to contain:

password-hash    {CRYPT}

If you do not then as soon as you use ldappasswd to change a password your user will no longer be able to log in. That is all.

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Jul 24

Why is XML Better?

Category: Programming, XML, XPath, XSLT

Why is XML better than custom internal formats? Isn’t a non-standard set of XML tags basically equivalent to a custom format when using data internally to an application? Absolutely not, and here is why.
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Jun 26

DVSL: An Alternative to XSLT

Category: Java, XML, XPath, XSLT

DVSL is a fairly small, little known, product associated with the Velocity project over at Apache which takes the best part of XSLT, XPATH, and replaces the verbose and frustrating scripting of XSLT with a java-based template language instead.
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Dec 10

Spirit Vs. Lex/yacc/et al.

What are the differences and when should I use one or the other?
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Nov 4

Boost Spirit III (Adding Error Handling)

Category: C++, Programming

This article expands the example from the previous two, here and here, to add more specific error information.

As always the full code from the example is available here here.

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Oct 13

Writing a custom check macro for the BOOST test library

Category: C++, Programming

In this article I demonstrate how to write your own check macros for the boost test library (not guaranteed to work in the future)

Full source code for this example can be downloaded here.
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