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Software Code Quality Of Apache Analyzed
fruey writes "Following Reasoning's February analysis of the Linux TCP/IP stack (putting it ahead of many commercial implementations for it's low error density), they recently pitted Apache 2.1 source code against commercial web server offerings, although they don't say which. Apparently, Apache is close, but no cigar..."
2.1 is'nt even out yet! the latest is 2.0.46!
Cats: All your base are belong to us.
Captain: Take off every sig !!
Reasoning found 31 software defects in 58,944 lines of source code of the Apache http server V2.1 code.
so what are the calling a defect?
So?
There are errors and there are errors. There are error that don't matter a jot, and there are errors that are show-stoppers.
I've worked on banking software containing code that was written in assembly for PD11s and developed over decades. The most horrible spaggetti code you could ever imagine. Why did the banks keep using it? Because for any particular input it always gave the correct output.
Years of bug fixing had made the code horrible and probably full of errors if you were looking at it from a purely theoretical/software engineering viewpoint. But from an input/output point of view, it was faultless.
Agreed. Things like splint often report "warnings" on code that shouldn't be. For instance
int some_func(char *somebuf)
{
if (somebuf == NULL) return ERROR;
somebuf[0] = 'a';
return OK;
}
Will generate a warning with splint saying "pointer may be null" despite the fact it cannot be.
Those tools are generally too sensitive and give too many false positives to be useful in the long run.
Tom
Someday, I'll have a real sig.
One word: architecture.
And not just the architecture of the web server, but the architecture of the entire platform. But specifically looking at the architecture of Apache versus the architecture of IIS, you'll immediately see that the goals of the two pieces of software are not the same. Look at things like IIS's metabase - the structural details of the server's configuration are kept in an in-memory data structure, which is easily modified while the server is running. Apache, in contrast, reads its configuration at startup, and uses it to determine which modules of code are loaded, and how they are used to process requests - fixing the behavior of the web server at startup.
IIS follows typical MS enterprise software design - it has to interface with COM, and the NT security model, and active directory, and the registry, and a million other systems, all in the name of integration, and enterprise management. Apache doesn't have PHBs telling it that it needs another way for the metabase to be edited, or a new instrumentation API, or whatever else a particular large customer asked for - and can get on with just providing its facilities cleanly.
That's why IIS has so many more security holes, even if it does (as may or may not be the case) have the same raw coding error rate as Apache.