Apache2::HookRun - Perl API for Invoking Apache HTTP phases

  # httpd.conf
  PerlProcessConnectionHandler MyApache2::PseudoHTTP::handler

  #file:MyApache2/PseudoHTTP.pm
  #---------------------------
  package MyApache2::PseudoHTTP;

  use Apache2::HookRun ();
  use Apache2::RequestUtil ();
  use Apache2::RequestRec ();

  use Apache2::Const -compile => qw(OK DECLINED DONE SERVER_ERROR);

  # implement the HTTP protocol cycle in protocol handler
  sub handler {
      my $c = shift;
      my $r = Apache2::RequestRec->new($c);

      # register any custom callbacks here, e.g.:
      # $r->push_handlers(PerlAccessHandler => \&my_access);

      $rc = $r->run_post_read_request();
      return $rc unless $rc == Apache2::Const::OK or $rc == Apache2::Const::DECLINED;

      $rc = $r->run_translate_name;
      return $rc unless $rc == Apache2::Const::OK or $rc == Apache2::Const::DECLINED;

      $rc = $r->run_map_to_storage;
      return $rc unless $rc == Apache2::Const::OK or $rc == Apache2::Const::DECLINED;

      # this must be run all a big havoc will happen in the following
      # phases
      $r->location_merge($path);

      $rc = $r->run_header_parser;
      return $rc unless $rc == Apache2::Const::OK or $rc == Apache2::Const::DECLINED;

      my $args = $r->args || '';
      if ($args eq 'die') {
          $r->die(Apache2::Const::SERVER_ERROR);
          return Apache2::Const::DONE;
      }

      $rc = $r->run_access_checker;
      return $rc unless $rc == Apache2::Const::OK or $rc == Apache2::Const::DECLINED;

      $rc = $r->run_auth_checker;
      return $rc unless $rc == Apache2::Const::OK or $rc == Apache2::Const::DECLINED;

      $rc = $r->run_check_user_id;
      return $rc unless $rc == Apache2::Const::OK or $rc == Apache2::Const::DECLINED;

      $rc = $r->run_type_checker;
      return $rc unless $rc == Apache2::Const::OK or $rc == Apache2::Const::DECLINED;

      $rc = $r->run_fixups;
      return $rc unless $rc == Apache2::Const::OK or $rc == Apache2::Const::DECLINED;

      # $r->run_handler is called internally by $r->invoke_handler,
      # invoke_handler sets all kind of filters, and does a few other
      # things but it's possible to call $r->run_handler, bypassing
      # invoke_handler
      $rc = $r->invoke_handler;
      return $rc unless $rc == Apache2::Const::OK or $rc == Apache2::Const::DECLINED;

      $rc = $r->run_log_transaction;
      return $rc unless $rc == Apache2::Const::OK or $rc == Apache2::Const::DECLINED;

      return Apache2::Const::OK;
  }

CWApache2::HookRun exposes parts of the Apache HTTP protocol implementation, responsible for invoking callbacks for each HTTP Request cycle phase.

Armed with that API, you could run some of the http protocol framework parts when implementing your own protocols. For example see how HTTP AAA (access, auth and authz) hooks are called from a protocol handler, implementing a command server, which has nothing to do with HTTP. Also you can see in Synopsis how to re-implement Apache HTTP cycle in the protocol handler.

Using this API you could probably also change the normal Apache behavior (e.g. invoking some hooks earlier than normal, or later), but before doing that you will probably need to spend some time reading through the Apache C code. That's why some of the methods in this document, point you to the specific functions in the Apache source code. If you just try to use the methods from this module, without understanding them well, don't be surprised if you will get some nasty crashes, from which mod_perl can't protect you.

CWApache2::HookRun provides the following functions and/or methods: Kill the current request

  $r->die($type);

ret: no return value

since: 2.0.00

This method doesn't really abort the request, it just handles the sending of the error response, logging the error and such. You want to take a look at the internals of CWap_die() in httpd-2.0/modules/http/http_request.c for more details. Run the response phase.

  $rc = $r->invoke_handler();

since: 2.0.00

CWinvoke_handler() allows modules to insert filters, sets a default handler if none is set, runs CWCIrun_handler()CW and handles some errors.

For more details see CWap_invoke_handler() in httpd-2.0/server/config.c. Run the resource access control phase.

  $rc = $r->run_access_checker();

since: 2.0.00

This phase runs before a user is authenticated, so this hook is really to apply additional restrictions independent of a user. It also runs independent of 'CWRequire' directive usage. Run the authentication phase.

  $rc = $r->run_auth_checker();

since: 2.0.00

This phase is used to check to see if the resource being requested is available for the authenticated user (CW$r->user and CW$r->ap_auth_type).

It runs after the access_checker and check_user_id hooks.

Note that it will only be called if Apache determines that access control has been applied to this resource (through a 'CWRequire' directive). Run the authorization phase.

  $rc = $r->run_check_user_id();

since: 2.0.00

This hook is used to analyze the request headers, authenticate the user, and set the user information in the request record (CW$r->user and CW$r->ap_auth_type).

This hook is only run when Apache determines that authentication/authorization is required for this resource (as determined by the 'CWRequire' directive).

It runs after the access_checker hook, and before the auth_checker hook. Run the fixup phase.

  $rc = $r->run_fixups();

since: 2.0.00

This phase allows modules to perform module-specific fixing of HTTP header fields. This is invoked just before the response phase. Run the response phase.

  $rc = $r->run_handler();

since: 2.0.00

CWrun_handler() is called internally by CWCIinvoke_handler()CW. Use CWrun_handler() only if you want to bypass the extra functionality provided by CWCIinvoke_handler()CW. Run the header parser phase.

  $rc = $r->run_header_parser();

since: 2.0.00

Run the logging phase.

  $rc = $r->run_log_transaction();

since: 2.0.00

This hook allows modules to perform any module-specific logging activities over and above the normal server things. Run the map_to_storage phase.

  $rc = $r->run_map_to_storage();

since: 2.0.00

This phase allows modules to set the per_dir_config based on their own context (such as CW<Proxy> sections) and responds to contextless requests such as CWTRACE that need no security or filesystem mapping based on the filesystem. Run the post_read_request phase.

  $rc = $r->run_post_read_request();

since: 2.0.00

This phase is run right after CWread_request() or CWinternal_redirect(), and not run during any subrequests. This hook allows modules to affect the request immediately after the request has been read, and before any other phases have been processes. This allows modules to make decisions based upon the input header fields Run the translate phase.

  $rc = $r->run_translate_name();

since: 2.0.00

This phase gives modules an opportunity to translate the URI into an actual filename. If no modules do anything special, the server's default rules will be applied. Run the type_checker phase.

  $rc = $r->run_type_checker();

since: 2.0.00

This phase is used to determine and/or set the various document type information bits, like CWContent-type (via CW$r->content_type), language, etc.

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