Bug 38903

Summary: r->allowed does not affect Allow response header
Product: Apache httpd-2 Reporter: Anton Lavrentiev <lavr>
Component: AllAssignee: Apache HTTPD Bugs Mailing List <bugs>
Severity: major Keywords: MassUpdate
Priority: P2    
Version: 2.0.55   
Target Milestone: ---   
Hardware: All   
OS: All   

Description Anton Lavrentiev 2006-03-09 03:06:05 UTC
There is a "request_rec::allowed" member, which is documented like so
(in include/httpd.h, struct request_rec):

     *  'allowed' is a bitvector of the allowed methods.
     *  A handler must ensure that the request method is one that
     *  it is capable of handling.  Generally modules should DECLINE
     *  any request methods they do not handle.  Prior to aborting the
     *  handler like this the handler should set r->allowed to the list
     *  of methods that it is willing to handle.  This bitvector is used
     *  to construct the "Allow:" header required for OPTIONS requests,
     *  Since the default_handler deals with OPTIONS, all modules can
     *  usually decline to deal with OPTIONS.  TRACE is always allowed,
     *  modules don't need to set it explicitly.
     *  Since the default_handler will always handle a GET, a
     *  module which does *not* implement GET should probably return
     *  HTTP_METHOD_NOT_ALLOWED.  Unfortunately this means that a Script GET
     *  handler can't be installed by mod_actions.
    apr_int64_t allowed; 

But "Allow:" is never actually constructed out of this member (done
in http/http_protocol.c, by make_allow()):

/* Build the Allow field-value from the request handler method mask.
 * Note that we always allow TRACE, since it is handled below.
static char *make_allow(request_rec *r) 

Naturally, this member is never referenced in this function,
nor in any other one across the entire package, except that it is
only _set_ by various modules as to how it is documented --  see above,
like for example in mod_status.c.

Thus, setting of r->allowed does not work, and only "Allow: TRACE" gets
returned in the response headers regardless of the value of r->allowed
when HTTP_METHOD_NOT_ALLOWED results from a handler.
Comment 1 A. Shaw 2007-03-30 08:01:13 UTC
This is a real problem.

ap_send_http_options() looks at r->allowed_methods->method_mask, not r->allowed.

You can do something like this as a workaround:
... r->allowed_methods->method_mask = r->allowed;
... ap_send_http_options(r);
Comment 2 William A. Rowe Jr. 2018-11-07 21:08:56 UTC
Please help us to refine our list of open and current defects; this is a mass update of old and inactive Bugzilla reports which reflect user error, already resolved defects, and still-existing defects in httpd.

As repeatedly announced, the Apache HTTP Server Project has discontinued all development and patch review of the 2.2.x series of releases. The final release 2.2.34 was published in July 2017, and no further evaluation of bug reports or security risks will be considered or published for 2.2.x releases. All reports older than 2.4.x have been updated to status RESOLVED/LATER; no further action is expected unless the report still applies to a current version of httpd.

If your report represented a question or confusion about how to use an httpd feature, an unexpected server behavior, problems building or installing httpd, or working with an external component (a third party module, browser etc.) we ask you to start by bringing your question to the User Support and Discussion mailing list, see [https://httpd.apache.org/lists.html#http-users] for details. Include a link to this Bugzilla report for completeness with your question.

If your report was clearly a defect in httpd or a feature request, we ask that you retest using a modern httpd release (2.4.33 or later) released in the past year. If it can be reproduced, please reopen this bug and change the Version field above to the httpd version you have reconfirmed with.

Your help in identifying defects or enhancements still applicable to the current httpd server software release is greatly appreciated.