On Fri, May 12, 2023 at 6:35 PM Stefan Eissing via dev
<dev@httpd.apache.org> wrote:
>
> Regarding https://bz.apache.org/bugzilla/show_bug.cgi?id=66499 I have a
> question.
>
> When using httpd in a forward proxy setup ("ProxyRequests On"), we expect
> absolute URLs in HTTP/1.1 requests. Fine.
>
> When accessing such a setup via HTTP/2, we get :scheme, :auhority and :path
> and, usually, do NOT want to convert that to absolute URIs in the reuqest
> line. That is what 66499 complained about. However, in the forward proxy
> case, we need it.
>
> How is mod_http2 supposed to know which case is in play? Any ideas?
It can't know I agree, but possibly mod_h2 could fill in r->parsed_uri
when creating the request_rec (as if a full uri-path were received),
that's what proxy_detect() needs to allow forward-proxying (in
addition to ProxyRequests on). Reverse-proxying won't use
r->parsed_uri.{scheme,hostname} anyway so ProxyRequests on/off would
be the only criteria, which seems fine?
PS: Since we are discussing PRs, maybe we can talk about PR 66597 :p
There it seems that in 2.4.x (i.e. !AP_HAS_RESPONSE_BUCKETS), the
H2_C2_REQUEST_IN filter will insert chunk encoding (via
read_and_chunk()) at AP_FTYPE_PROTOCOL, which is the same level as the
HTTP_IN filter supposed to consume this chunking (IIUC).
Could it be possible that H2_C2_REQUEST_IN gets added earlier than
HTTP_IN such that the order of the two is backward (i.e. the chunk
encoding is never consumed), which is why mod_proxy ends up
reading/forwarding chunked encoding as if HTTP_IN was not called?
So maybe the below patch would make the ordering more robust:
Index: modules/http2/h2_c2.c
===================================================================
--- modules/http2/h2_c2.c (revision 1909607)
+++ modules/http2/h2_c2.c (working copy)
@@ -854,7 +854,7 @@ void h2_c2_register_hooks(void)
NULL, AP_FTYPE_NETWORK);
ap_register_input_filter("H2_C2_REQUEST_IN", h2_c2_filter_request_in,
- NULL, AP_FTYPE_PROTOCOL);
+ NULL, AP_FTYPE_PROTOCOL - 1);
ap_register_output_filter("H2_C2_RESPONSE_OUT", h2_c2_filter_response_out,
NULL, AP_FTYPE_PROTOCOL);
ap_register_output_filter("H2_C2_TRAILERS_OUT", h2_c2_filter_trailers_out,
?
Regards;
Yann.
