Add directives to control two protocol options:

 HttpContentLengthHeadZero - allow Content-Length of 0 to be returned on HEAD
 HttpExpectStrict - allow admin to control whether we must see "100-continue"

This is helpful when using Ceph's radosgw and httpd.

Inspired by: Yehuda Sadeh <yehuda@inktank.com>
See https://github.com/ceph/apache2/commits/precise

* include/http_core.h
  (core_server_config): Add http_cl_head_zero and http_expect_strict fields.
* modules/http/http_filters.c
  (ap_http_header_filter): Only clear out the C-L if http_cl_head_zero is not
  explictly set.
* server/core.c
  (merge_core_server_configs): Add new fields.
  (set_cl_head_zero, set_expect_strict): New config helpers.
  (HttpContentLengthHeadZero, HttpExpectStrict): Declare new directives.
* server/protocol.c
  (ap_read_request): Allow http_expect_strict to control if we return 417.
* include/ap_mmn.h
  (MODULE_MAGIC_NUMBER_MAJOR, MODULE_MAGIC_NUMBER_MINOR): Bump.
* CHANGES: Add a brief description.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1554303 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 7 insertions, 1 deletions

diff --git a/modules/http/http_filters.c b/modules/http/http_filters.c
index 1224914108..dc3220e344 100644
--- a/modules/http/http_filters.c
+++ b/modules/http/http_filters.c
@@ -1245,10 +1245,16 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_http_header_filter(ap_filter_t *f,
      * zero C-L to the client.  We can't just remove the C-L filter,
      * because well behaved 2.0 handlers will send their data down the stack,
      * and we will compute a real C-L for the head request. RBB
+     *
+     * Allow modification of this behavior through the
+     * HttpContentLengthHeadZero directive.
+     *
+     * The default (unset) behavior is to squelch the C-L in this case.
      */
     if (r->header_only
         && (clheader = apr_table_get(r->headers_out, "Content-Length"))
-        && !strcmp(clheader, "0")) {
+        && !strcmp(clheader, "0")
+        && conf->http_cl_head_zero != AP_HTTP_CL_HEAD_ZERO_ENABLE) {
         apr_table_unset(r->headers_out, "Content-Length");
     }