Older blog entries for Fefe (starting at number 15)

HAL 2001 ruled!

Much progress! Linus told me that I should not use kernel headers from user space in the diet libc, so I cleansed the diet libc header files. It was quite a lot of ugly work, but it had to be done. Now, theoretically, you can cross-compile it without needing anything else (except gcc and binutils of course) from completely strange and alien platforms like cygwin/alpha or a PDP/11 ;)

Olaf got an ld.so for the diet libc working on x86, and it's only 7k! A little more cleaning up and I say we are ripe for one-dot-oh, baby!

What else is new? I resurrected my djbdns IPv6 patches and added full IPv6 transport capabilities, not only for tinydns but also for dnscache (which took a lot of messing with internal structures and resulted in a 70k patch). It would have taken weeks had I not been able to reuse code from libowfat. Whew.

openssl did link but had some problems. Now it passes the complete test suite. And we linked openssh. And boa. And GNU bash (with readline and history).

The diet libc is maturing quickly. Recently, we successfully linked busybox, ncurses, vim, openssl, fdisk, mount and umount against it. Olaf is moving forward nicely with the shared library loader, the pthreads appear to work fine,... I'm happy. Mandrakesoft has ported their installation floppies to it, saving lots of space in the process.

Olaf and I are thinking about starting a libstdc++ using libowfat as foundation. I wrote a few libowfat functions for this, and Olaf already did a test iostream cout that is just a hello world and it was below 3k although it contained buffering code!

I cleaned up the diet libc mess when cross compiling a little. I also added a wrapper for gcc, so now you can say diet gcc -o t t.c and it will add all the magic gcc options by itself. It will also work when you say diet sparc-linux-gcc -o t t.c and link against the sparc cross-compiled dietlibc.a. I hope that makes diet libc more accessible.

I'm driving to CeBIT tomorrow, so I released new versions of the diet libc and the embedded utils tonight. It's getting more complete by the day. Recent additions are crypt and get{pw,sp,gr}ent, so I can now link checkpassword against it - one of the few pieces of djb software that did not work until now.

I linked most of the services on www.fefe.de against the diet libc now, and the Apache is by far the largest remaining memory hog, so it needs to go. I need CGI, I need it to run in a chroot jail, and I need basic header rewriting capabilities. Let's see how far I get.

I am currently writing an article about MPLS for c't magazine, and they want it to be ready tomorrow noon. The text is largely ready, but I need to sketch some illustrations now.

gethostbyaddr works now, too. DNS is even uglier than I previously thought. When you query for an A record (i.e. you want to know the IP for a name), you get n DNS records back. The problem is, there is no length byte, i.e. you don't know how long each record is. Unless you have code that knows how to parse the data payload for each record type, that is!

No problem, you might think. When you ask for A records, you will only get A records in replies, right? Wrong! You can also get CNAME records. And maybe DNAME? DNSSEC records?

I wonder what bozo invented a protocol like that and had the nerve to write in the RFCs that DNS is designed to be extensible.

gethostbyname is working now, and it's below 5k of code. It does not do name qualification yet (i.e. try appending domains from /etc/resolv.conf), but it's a start.

One of the major parts missing from the diet libc is DNS, i.e. gethostbyname and friends. I'm working on the code now, and it ain't pleasant. One obstacle on the way was inet_aton, which is very lenient in what it accepts. The more I dig into the libc, the more dirt I find.

I renamed libfefe to libowfat so you can against it with -lowfat. OK, it's a weak joke, but it's better than libfefe. ;-)

libowfat has grown to include scan, fmt, uint, stralloc, str and open. unix and socket is in the works.

Anyway, the diet libc is now feature complete enough that I can compile and link non-trivial programs like gzip, lzop and bzip2 against it (with large file support). Combined with the new upx beta it is a very powerful tool for low memory situations like rescue floppies.