On 04/29/2014 02:22 PM, Jim Jagielski wrote:
On Apr 29, 2014, at 7:41 AM, Jan Kaluža <jkal...@redhat.com> wrote:
That's what we do with current patch I think, don't we? In the patch, we create "char
*match_name" which is NULL when the worker_name is not regex and contains the escaped name if
regex is used (with "$N" replaced by '*').
ap_proxy_get_worker() later checks the match_name and if it's not NULL, it
tries regex matching using ap_proxy_strcmp_ematch().
The actual problem is that ap_proxy_get_worker() cannot find out proper
proxy_worker, because this method is not regex aware. To make it regex aware,
we have to distinguish regex workers during creation,
right, hence the flag.
replace the regex variables ($N -> *) in some safe manner and allow
ap_proxy_get_worker() to find the right worker using this new info. And that's
what the patch does.
Why replace? Why can't we store the name as is?
Because later we have to match the URL of request with some proxy_worker.
If you configure ProxyPassMatch like this:
ProxyPassMatch ^/test/(\d+)/foo.jpg http://x/$1/foo.jpg
Then the proxy_worker name would be "http://x/$1/foo.jpg";.
If you receive request with URL "http://x/something/foo.jpg";,
ap_proxy_get_worker() will have to find out the worker with name
"http://x/$1/foo.jpg";. The question here is how it would do that?
The answer used in the patch is "we change the worker name to
http://x/*/foo.jpg"; and check if the URL ("http://x/something/foo.jpg";
in our case) matches that worker.
If we store the original name with $N, we will have to find out
different way how to match the worker (probably emulating wildcard
pattern matching)
It would be possible to store only the original name (with "$N"
variables), store the flag that the proxy worker is using regex and
change ap_proxy_strcmp_ematch() function to treat "$N" as "*", but I
don't see any real advantage here.
The version I looked at had some 'use_regex' logic outside of
ap_proxy_get_worker(), right before we call it, in fact. Maybe
I'm seeing an older version of the patch?
I think that's the correct patch. It has use_regex only for creating the
proxy_worker to distinguish between "normal" worker and "regex" worker.
Note that "use_regex" does not influence the call of
"ap_proxy_get_worker()". As I said, it's used only to distinguish
whether the newly created worker is "normal" worker or "regex" worker.
Regards,
Jan Kaluza
![http://x/$1/foo.jpg"](http://x/$1/foo.jpg"){kind=link}
![http://x/something/foo.jpg"](http://x/something/foo.jpg"){kind=link}
![http://x/*/foo.jpg"](http://x/*/foo.jpg"){kind=link}