nick at webthing.com
Mon Dec 3 18:37:56 UTC 2012
On Mon, 3 Dec 2012 21:31:52 +0400
Maxim Dounin <mdounin at mdounin.ru> wrote:
> > Thanks for the reply. You mean you're happy to add a new-connection
> > hook, but not a context?
> Something like this. I would like to see use case first though,
> to make sure it indeed requires connection start hook.
The basic use case is for a module that hooks in a library
that needs to be notified of new connections.
There are a couple of reasons for this. One is that it has
its own connection struct that needs to be initialised before
it can process requests on the connection. To do that
per-request would require a lookup table of existing
connections, and a mutex to prevent a race condition
between requests on a connection. In other words, quite
a lot of extra complexity.
The other reason is, this is a security tool, and we'd like
to know about any connections that are NOT followed by a
valid (and notifiable) HTTP request, and might be part of
an attack on a server.
> As of now its always true. Note though, that with SPDY patches
> Valentin is working on it will likely change. I've just talked to
> him and he suggests to compare r->connection->fd instead as a
> more bulletproof solution.
Surely an fd will be recycled/re-used?
OK, I can work around that, too: just a little extra work to re-use
the library's connection initialisation to generate a key.
Though it means holding a mutex rather longer!
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