Joe Schaefer wrote:
I don't think people groked my point very well. When you POST
via HTTP/1.1, httpd will send a "Continue: 100" header before it
starts doing blocking reads on the client socket (any attempts to
read from the client will trigger this behavior). If you really
want to interrupt an upload, the time to do it is *before* httpd
sends that header. Afterwards httpd commits to reading the entire
request in *before it lets you send a response* in order to maintain
protocol compliance.
So basically, it means that there is no way to stop an upload, once the browser has
started to send the file, right ?
The best you could do, is before you start reading, check if there was a Content-length
header in the request, and if there was, check if the size it says is lower/equal to what
you are prepared to accept (aka what this user is still allowed to upload e.g.).
- if it is ok, then start reading
- if it is not ok, send an error response to block the POST, before you read
(preferably a nice one, to let the user know why it does not work)
All this depends on 2 things :
- that there was a Content-length header in the request (which is not necessarily the case
if "chunked" encoding is allowed on the part of a client)
- that the fact of retrieving the request header does not automatically cause the reading
and parsing of the whole request body
All the above just guessing, and awaiting confirmation...
(And all the above, and the rest of this discussion, assuming that the POST can be large
enough that it all matters (like uploading a multi-MB file e.g.))
For reasons that escape me it doesn't look like mod_perl exposes
r->remaining, which is the thing to check when looking at the
pending number of bytes the client wants to send. If I'm not wrong
that should be easy enough for us to address. apreq won't read
anything in in this situation tho, so you're good on that front.
CGI.pm I'd bet doesn't try to read either if the pending data
is too big, but I haven't looked at that codebase in a long time.
----- Original Message -----
From: Vincent Veyron <vv.li...@wanadoo.fr>
To: mike cardeiro <mcarde...@yahoo.com>
Cc: Torsten Förtsch <torsten.foert...@gmx.net>; "modperl@perl.apache.org"
<modperl@perl.apache.org>
Sent: Wednesday, February 8, 2012 4:24 PM
Subject: Re: Interrupting a POST with file upload
Le mercredi 08 février 2012 à 05:53 -0800, mike cardeiro a écrit :
This is a fantastic list!
Agreed.
On the same note : I was recently presenting the legal case management
app in my sig to an institutional client in the south of France, and the
IT guy said that it had a 'fantastic architecture' (I assume he was
talking about mod_perl).
--
Vincent Veyron
http://marica.fr/
Logiciel de gestion des sinistres et des contentieux pour le service juridique
