Re: chunked trailers input filter processing by ap_http_filter should be documented
On Sun, 10 Feb 2013 08:25:35 -0800 (PST) Joe Schaefer joe_schae...@yahoo.com wrote: Here's a sledgehammer patch to ap_rgetline_core() to replace r-input_filters with r-proto_input_filters. This would still mean protocol filters behind ap_http_filter would need to punt on these calls, but that's a lot more reasonable than imposing it on AP_FTYPE_RESOURCE and similar filters as well. +1, seems much saner. Request filters have no business reading beyond end of request body.
Re: chunked trailers input filter processing by ap_http_filter should be documented
Thx Bill! I will let a few days of lazy consensus pass before committing this to trunk. From: William A. Rowe Jr. wr...@rowe-clan.net To: dev@httpd.apache.org Cc: joe_schae...@yahoo.com Sent: Tuesday, February 12, 2013 11:52 AM Subject: Re: chunked trailers input filter processing by ap_http_filter should be documented On Sun, 10 Feb 2013 08:25:35 -0800 (PST) Joe Schaefer joe_schae...@yahoo.com wrote: Here's a sledgehammer patch to ap_rgetline_core() to replace r-input_filters with r-proto_input_filters. This would still mean protocol filters behind ap_http_filter would need to punt on these calls, but that's a lot more reasonable than imposing it on AP_FTYPE_RESOURCE and similar filters as well. +1, seems much saner. Request filters have no business reading beyond end of request body.
chunked trailers input filter processing by ap_http_filter should be documented
So ap_http_filter winds up calling ap_get_mime_headers once it recognizes that the request body has finished, to process the trailing headers on chunked requests. This is actually a strange thing to do, because it means ap_http_filter winds up calling ap_get_brigade on r-input_filters with AP_MODE_GETLINE set, right in the middle of an existing ap_get_brigade sequence on the filter chain. In other words, this recursion only works if all post-protocol filters are written to punt on processing AP_MODE_GETLINE invocations- this is what we need to document somewhere if we don't want to fix the code. It would be logically better if there were a way to pass a ap_filter_t argument to ap_get_mime_headers so ap_http_filter didn't need to reach backwards in the input filter chain just to finish its HTTP protocol handling.
Re: chunked trailers input filter processing by ap_http_filter should be documented
Here's a sledgehammer patch to ap_rgetline_core()
to replace r-input_filters with r-proto_input_filters.
This would still mean protocol filters behind ap_http_filter
would need to punt on these calls, but that's a lot
more reasonable than imposing it on AP_FTYPE_RESOURCE
and similar filters as well.
Index: protocol.c
===
--- protocol.c (revision 1331861)
+++ protocol.c (working copy)
@@ -229,7 +229,7 @@
for (;;) {
apr_brigade_cleanup(bb);
- rv = ap_get_brigade(r-input_filters, bb, AP_MODE_GETLINE,
+ rv = ap_get_brigade(r-proto_input_filters, bb, AP_MODE_GETLINE,
APR_BLOCK_READ, 0);
if (rv != APR_SUCCESS) {
return rv;
@@ -346,7 +346,7 @@
apr_brigade_cleanup(bb);
/* We only care about the first byte. */
- rv = ap_get_brigade(r-input_filters, bb, AP_MODE_SPECULATIVE,
+ rv = ap_get_brigade(r-proto_input_filters, bb,
AP_MODE_SPECULATIVE,
APR_BLOCK_READ, 1);
if (rv != APR_SUCCESS) {
return rv;
From: Joe Schaefer joe_schae...@yahoo.com
To: dev@httpd.apache.org dev@httpd.apache.org
Sent: Sunday, February 10, 2013 11:05 AM
Subject: chunked trailers input filter processing by ap_http_filter should be
documented
So ap_http_filter winds up calling ap_get_mime_headers
once it recognizes that the request body has finished,
to process the trailing headers on chunked requests.
This is actually a strange thing to do, because it means
ap_http_filter winds up calling ap_get_brigade on
r-input_filters with AP_MODE_GETLINE set, right in the middle of an
existing ap_get_brigade sequence on the filter chain.
In other words, this recursion only works if all
post-protocol filters are written to punt on processing
AP_MODE_GETLINE invocations- this is what we need to
document somewhere if we don't want to fix the code.
It would be logically better if there were a way to pass a
ap_filter_t argument to ap_get_mime_headers so ap_http_filter
didn't need to reach backwards in the input filter chain just
to finish its HTTP protocol handling.
