bert hubert finally blogs

WiFi antenna, Fine, PowerDNS, Windows

Posted by bert hubert Sat, 06 May 2006 21:58:00 GMT

Welcome back after this 9-day hiatus from my Blog!

Ok, what has happened. I had two good experiences with local electronics stores here in Delft. Goris was unable to provide me with the proper cable to hook up my shiny new WiFi directional antenna, but they referred me to HEC, which did have the components to make the cable. My skills with the soldering iron are humorous at best. However the people at HEC kindly offered to make the cable for me! So now I finally have a working combination of antenna, cable and adapter. And to make things perfect, Goris allowed me to test my new WiFi card to verify Linux compatability. Luckily it all works. I hope to hook up pahu tomorrow.

Slight damper on today is that I was fined for driving my bicycle through a street here in Delft that turned out to be for pedestrians only. 30 euros too. I normally am all in favour of the rule of law but this makes little sense. It is fortunate therefore that the actual fine contained a number of errors which I am sure invalidate it, so I wasted no time in drafting a written protest. I’m not usually like this but I was pissed of at the inanity of this fine.

PowerDNS & Windows

As staunch a supporter as I am of Open Source, my technology wants to go places. So, I downloaded the ‘free’ version of Visual Studio Express 2005 from Microsoft. And a fine compiler it is! I had fixed a bunch of initial incompatabilities using the (also fine) Minimalistic GCC for Windows. I think this is the first Microsoft C++ compiler that can really be taken seriously. VC++ debugging mode found two real bugs in PowerDNS, which motivated me to turn on the ‘debugging mode’ of the G++ libstdc++ as well, which uncovered two further bugs!

This strengthens my feelings that porting to different platforms helps uncover bugs which aren’t (yet) a problem but might be.

Ahu’s quick guide to porting to windows:

1. Use VC++ 2005, earlier versions have a lot more problems with constructions g++ accepts. It also appears that VC++ 2005 is smart with respect to UNIX/DOS line endings.
2. Separate the really different things to different files, which share one header file. Don’t make #ifdef soup!
3. Make a single include file that includes OS-dependent include files (like windows.h).
4. On windows, one can only write and read from sockets using send(to) and recv(from). As these functions work for UNIX as well, use these functions exclusively on sockets.
5. To close a socket under windows, you need closesocket() and not close. Candidate for the file mentioned under 1.
6. Windows has different errno traditions. All network (‘winsock’) related errors need WSAGetLastError(). See here.
7. Use ‘Tortoise’ Subversion for revision control, integrates really well with both Windows and UNIX. Also smart about line endings.
8. If, as for me, your prime development platform is UNIX, install the MINGW crosscompiler so you can easily verify the code at least compiles for Windows. This helps prevent code-rot at an early stage.
9. Get a Windows buddy :-) Many thanks to Michel Stol, who is far more at home in Windows than I am.

PowerDNS 3.1

I hope to release PowerDNS 3.1 shortly, and make things settle down a bit then. Since the previous blog post, I added full blown IPv6 outgoing support, with IPv6 achieving full parity - any IPv6 nameserves that are faster than their IPv4 partners will receive more queries.

The ‘–export-etc-hosts’ stuff also works fine now, which should allow many networks to simply run unconfigured, save for that option, and have everything Just Work.

For more, see here.