[vlc-devel] 0.9.2 SAP

Rémi Denis-Courmont rem at videolan.org
Tue Sep 23 18:24:42 CEST 2008


Le mardi 23 septembre 2008 18:44:42 Marian Ďurkovič, vous avez écrit :
> What's the point of pedantically enforcing order of fields in SDPs on the
> *receive* side - especially when it makes the code unnecessarily complex?

For the record, some time when we had the old _bug-ridden_ SDP parser, we 
ended up writing _incorrect_ SDPs. If we revert back to the crappy parser, we 
will soon enough start breaking the "basic Internet principles" by not being 
conservative in what we send. Yes, our SDPs broke other people's valid 
software. Because we had nothing to validate our own implementation against. 
Same apply to other people, who will not write broken SAP/SDP implementations 
if they use VLC 0.9.2 client-side.
Frankly, I prefer conservative read and conservative write to liberal read and 
outright broken write. But that was just some principles rant.


No. Here are my real concerns. The not-so-new SDP parser was written to fix 
problems with real-life (non-broken) announces. It's been available for 
testing for at least nineteen months now. Nobody ever complained until 
yesterday. Sorry, that's just too late. I am totally not going to risk 
re-introducing all those parsing bugs and their nasty security implications 
post 0.9.2. Especially not for the sake of third-party commercial broken 
so-called "professional" softwares, whereas we are a volunteer amateur 
project.

> And I bet you have some logical error in that code, since expect is never
> assigned the value of 'm' although you have "case 'm'" there...

I cannot find an actual bug there. The case statement is not used but it helps 
readability.

-- 
Rémi Denis-Courmont
http://git.remlab.net/cgi-bin/gitweb.cgi?p=vlc-courmisch.git;a=summary



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