After a few hours of digging through the nginx code, I think I've
discovered the nature of the bug, but I still don't know how to fix it
just yet. I'm using the 3rd-party upload module to handle my uploads,
which are then sent along to a fastcgi process.
The problem I'm having is I can't seem to set a custom error page for
HTTP 413 errors. If I issue a file upload to an nginx url and it
exceeds the maximum size set in my configuration, I want the custom
error page to show. Instead I get the nginx default.
error_page 413 /err/413.html
when I upload will give me something like this in my error log:
2009/06/03 23:08:06 [error] 19180#0: *163 client intended to send too
large body: 995365 bytes, client: 192.168.98.223, server: localhost,
request: "POST /attach HTTP/1.1", host: "localhost:10443", referrer: "https://localhost:10443/attach
"
2009/06/03 23:08:06 [error] 19180#0: *163 client intended to send too
large body: 995365 bytes, client: 192.168.98.223, server: localhost,
request: "POST /attach HTTP/1.1", host: "localhost:10443", referrer: "https://localhost:10443/attach
"
When I pointed the error page at an invalid location (error_page 413
@bad_location) I got this instead:
2009/06/03 23:06:31 [error] 11885#0: *153 client intended to send too
large body: 995365 bytes, client: 192.168.98.223, server: localhost,
request: "POST /attach HTTP/1.1", host: "localhost:10443", referrer: "https://localhost:10443/attach
"
2009/06/03 23:06:31 [error] 11885#0: *153 could not find named
location "@bad_location", client: 192.168.98.223, server: localhost,
request: "POST /attach HTTP/1.1", host: "localhost:10443", referrer: "https://localhost:10443/attach
"
So what I think is happening is the initial request is made, which
eventually throws a NGX_HTTP_REQUEST_ENTITY_TOO_LARGE error, resulting
in the error page handler to run. It tries cleaning up the request
and resets it to an internal request for /err/413.html, but I think it
isn't cleaning everything up well enough. So when the error page tries
to load, it notices that the content length of the request is still
too large, and throws an error as well.
Does anyone have any idea how to fix this, or would like to submit a
patch? I'm going to try my best to fix the code, and if I can I'll
send a patch in to the mailing list. But my C skills aren't that
solid, and I'm unfamiliar with the nginx codebase.
Thank you, and I hope someone has a magic-bullet solution for this. :-)
