text: /* Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  /*
   * http_request.c: functions to get and process requests
   *
   * Rob McCool 3/21/93
   *
   * Thoroughly revamped by rst for Apache.  NB this file reads
   * best from the bottom up.
   *
   */
  
  #include "apr_strings.h"
  #include "apr_file_io.h"
  #include "apr_fnmatch.h"
  
  #define APR_WANT_STRFUNC
  #include "apr_want.h"
  
  #include "ap_config.h"
  #include "httpd.h"
  #include "http_config.h"
  #include "http_request.h"
  #include "http_core.h"
  #include "http_protocol.h"
  #include "http_log.h"
  #include "http_main.h"
  #include "util_filter.h"
  #include "util_charset.h"
  #include "scoreboard.h"
  
  #include "mod_core.h"
  
  #if APR_HAVE_STDARG_H
  #include <stdarg.h>
  #endif
  
  APLOG_USE_MODULE(http);
  
  /*****************************************************************
   *
   * Mainline request processing...
   */
  
  /* XXX A cleaner and faster way to do this might be to pass the request_rec
   * down the filter chain as a parameter.  It would need to change for
   * subrequest vs. main request filters; perhaps the subrequest filter could
   * make the switch.
   */
  static void update_r_in_filters(ap_filter_t *f,
                                  request_rec *from,
                                  request_rec *to)
  {
      while (f) {
          if (f->r == from) {
              f->r = to;
          }
          f = f->next;
      }
  }
  
  static void ap_die_r(int type, request_rec *r, int recursive_error)
  {
      char *custom_response;
      request_rec *r_1st_err = r;
  
      if (type == OK || type == DONE) {
          ap_finalize_request_protocol(r);
          return;
      }
  
      if (!ap_is_HTTP_VALID_RESPONSE(type)) {
          ap_filter_t *next;
  
          /*
           * Check if we still have the ap_http_header_filter in place. If
           * this is the case we should not ignore the error here because
           * it means that we have not sent any response at all and never
           * will. This is bad. Sent an internal server error instead.
           */
          next = r->output_filters;
          while (next && (next->frec != ap_http_header_filter_handle)) {
                 next = next->next;
          }
  
          /*
           * If next != NULL then we left the while above because of
           * next->frec == ap_http_header_filter
           */
          if (next) {
              if (type != AP_FILTER_ERROR) {
                  ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01579)
                                "Invalid response status %i", type);
              }
              else {
                  ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02831)
                                "Response from AP_FILTER_ERROR");
              }
              type = HTTP_INTERNAL_SERVER_ERROR;
          }
          else {
              return;
          }
      }
  
      /*
       * The following takes care of Apache redirects to custom response URLs
       * Note that if we are already dealing with the response to some other
       * error condition, we just report on the original error, and give up on
       * any attempt to handle the other thing "intelligently"...
       */
      if (recursive_error != HTTP_OK) {
          while (r_1st_err->prev && (r_1st_err->prev->status != HTTP_OK))
              r_1st_err = r_1st_err->prev;  /* Get back to original error */
  
          if (r_1st_err != r) {
              /* The recursive error was caused by an ErrorDocument specifying
               * an internal redirect to a bad URI.  ap_internal_redirect has
               * changed the filter chains to point to the ErrorDocument's
               * request_rec.  Back out those changes so we can safely use the
               * original failing request_rec to send the canned error message.
               *
               * ap_send_error_response gets rid of existing resource filters
               * on the output side, so we can skip those.
               */
              update_r_in_filters(r_1st_err->proto_output_filters, r, r_1st_err);
              update_r_in_filters(r_1st_err->input_filters, r, r_1st_err);
          }
  
          custom_response = NULL; /* Do NOT retry the custom thing! */
      }
      else {
          int error_index = ap_index_of_response(type);
          custom_response = ap_response_code_string(r, error_index);
          recursive_error = 0;
      }
  
      r->status = type;
  
      /*
       * This test is done here so that none of the auth modules needs to know
       * about proxy authentication.  They treat it like normal auth, and then
       * we tweak the status.
       */
      if (HTTP_UNAUTHORIZED == r->status && PROXYREQ_PROXY == r->proxyreq) {
          r->status = HTTP_PROXY_AUTHENTICATION_REQUIRED;
      }
  
      /* If we don't want to keep the connection, make sure we mark that the
       * connection is not eligible for keepalive.  If we want to keep the
       * connection, be sure that the request body (if any) has been read.
       */
      if (ap_status_drops_connection(r->status)) {
          r->connection->keepalive = AP_CONN_CLOSE;
      }
  
      /*
       * Two types of custom redirects --- plain text, and URLs. Plain text has
       * a leading '"', so the URL code, here, is triggered on its absence
       */
  
      if (custom_response && custom_response[0] != '"') {
  
          if (ap_is_url(custom_response)) {
              /*
               * The URL isn't local, so lets drop through the rest of this
               * apache code, and continue with the usual REDIRECT handler.
               * But note that the client will ultimately see the wrong
               * status...
               */
              r->status = HTTP_MOVED_TEMPORARILY;
              apr_table_setn(r->headers_out, "Location", custom_response);
          }
          else if (custom_response[0] == '/') {
              const char *error_notes;
              r->no_local_copy = 1;       /* Do NOT send HTTP_NOT_MODIFIED for
                                           * error documents! */
              /*
               * This redirect needs to be a GET no matter what the original
               * method was.
               */
              apr_table_setn(r->subprocess_env, "REQUEST_METHOD", r->method);
  
              /*
               * Provide a special method for modules to communicate
               * more informative (than the plain canned) messages to us.
               * Propagate them to ErrorDocuments via the ERROR_NOTES variable:
               */
              if ((error_notes = apr_table_get(r->notes,
                                               "error-notes")) != NULL) {
                  apr_table_setn(r->subprocess_env, "ERROR_NOTES", error_notes);
              }
              r->method = "GET";
              r->method_number = M_GET;
              ap_internal_redirect(custom_response, r);
              return;
          }
          else {
              /*
               * Dumb user has given us a bad url to redirect to --- fake up
               * dying with a recursive server error...
               */
              recursive_error = HTTP_INTERNAL_SERVER_ERROR;
              ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01580)
                          "Invalid error redirection directive: %s",
                          custom_response);
          }
      }
      ap_send_error_response(r_1st_err, recursive_error);
  }
  
  AP_DECLARE(void) ap_die(int type, request_rec *r)
  {
      ap_die_r(type, r, r->status);
  }
  
  static void check_pipeline(conn_rec *c, apr_bucket_brigade *bb)
  {
      apr_status_t rv;
      int num_blank_lines = DEFAULT_LIMIT_BLANK_LINES;
      ap_input_mode_t mode = AP_MODE_SPECULATIVE;
      apr_size_t cr = 0;
      char buf[2];
  
      c->data_in_input_filters = 0;
      while (c->keepalive != AP_CONN_CLOSE && !c->aborted) {
          apr_size_t len = cr + 1;
  
          apr_brigade_cleanup(bb);
          rv = ap_get_brigade(c->input_filters, bb, mode,
                              APR_NONBLOCK_READ, len);
          if (rv != APR_SUCCESS || APR_BRIGADE_EMPTY(bb)) {
              /*
               * Error or empty brigade: There is no data present in the input
               * filter
               */
              if (mode == AP_MODE_READBYTES) {
                  /* Unexpected error, stop with this connection */
                  ap_log_cerror(APLOG_MARK, APLOG_ERR, rv, c, APLOGNO(02967)
                                "Can't consume pipelined empty lines");
                  c->keepalive = AP_CONN_CLOSE;
              }
              break;
          }
  
          /* Ignore trailing blank lines (which must not be interpreted as
           * pipelined requests) up to the limit, otherwise we would block
           * on the next read without flushing data, and hence possibly delay
           * pending response(s) until the next/real request comes in or the
           * keepalive timeout expires.
           */
          rv = apr_brigade_flatten(bb, buf, &len);
          if (rv != APR_SUCCESS || len != cr + 1) {
              int log_level;
              if (mode == AP_MODE_READBYTES) {
                  /* Unexpected error, stop with this connection */
                  c->keepalive = AP_CONN_CLOSE;
                  log_level = APLOG_ERR;
              }
              else {
                  /* Let outside (non-speculative/blocking) read determine
                   * where this possible failure comes from (metadata,
                   * morphed EOF socket => empty bucket? debug only here).
                   */
                  c->data_in_input_filters = 1;
                  log_level = APLOG_DEBUG;
              }
              ap_log_cerror(APLOG_MARK, log_level, rv, c, APLOGNO(02968)
                            "Can't check pipelined data");
              break;
          }
  
          if (mode == AP_MODE_READBYTES) {
              mode = AP_MODE_SPECULATIVE;
              cr = 0;
          }
          else if (cr) {
              AP_DEBUG_ASSERT(len == 2 && buf[0] == APR_ASCII_CR);
              if (buf[1] == APR_ASCII_LF) {
                  mode = AP_MODE_READBYTES;
                  num_blank_lines--;
              }
              else {
                  c->data_in_input_filters = 1;
                  break;
              }
          }
          else {
              if (buf[0] == APR_ASCII_LF) {
                  mode = AP_MODE_READBYTES;
                  num_blank_lines--;
              }
              else if (buf[0] == APR_ASCII_CR) {
                  cr = 1;
              }
              else {
                  c->data_in_input_filters = 1;
                  break;
              }
          }
          /* Enough blank lines with this connection?
           * Stop and don't recycle it.
           */
          if (num_blank_lines < 0) {
              c->keepalive = AP_CONN_CLOSE;
          }
      }
  }
  
  
  AP_DECLARE(void) ap_process_request_after_handler(request_rec *r)
  {
      apr_bucket_brigade *bb;
      apr_bucket *b;
      conn_rec *c = r->connection;
  
      /* Send an EOR bucket through the output filter chain.  When
       * this bucket is destroyed, the request will be logged and
       * its pool will be freed
       */
      bb = apr_brigade_create(c->pool, c->bucket_alloc);
      b = ap_bucket_eor_create(c->bucket_alloc, r);
      APR_BRIGADE_INSERT_HEAD(bb, b);
  
      /* Find the last request, taking into account internal
       * redirects. We want to send the EOR bucket at the end of
       * all the buckets so it does not jump the queue.
       */
      while (r->next) {
          r = r->next;
      }
  
      ap_pass_brigade(r->output_filters, bb);
  
      /* The EOR bucket has either been handled by an output filter (eg.
       * deleted or moved to a buffered_bb => no more in bb), or an error
       * occured before that (eg. c->aborted => still in bb) and we ought
       * to destroy it now. So cleanup any remaining bucket along with
       * the orphan request (if any).
       */
      apr_brigade_cleanup(bb);
  
      /* From here onward, it is no longer safe to reference r
       * or r->pool, because r->pool may have been destroyed
       * already by the EOR bucket's cleanup function.
       */
  
      check_pipeline(c, bb);
      apr_brigade_destroy(bb);
      if (c->cs)
          c->cs->state = (c->aborted) ? CONN_STATE_LINGER
                                      : CONN_STATE_WRITE_COMPLETION;
      AP_PROCESS_REQUEST_RETURN((uintptr_t)r, r->uri, r->status);
      if (ap_extended_status) {
          ap_time_process_request(c->sbh, STOP_PREQUEST);
      }
  }
  
  void ap_process_async_request(request_rec *r)
  {
      conn_rec *c = r->connection;
      int access_status;
  
      /* Give quick handlers a shot at serving the request on the fast
       * path, bypassing all of the other Apache hooks.
       *
       * This hook was added to enable serving files out of a URI keyed
       * content cache ( e.g., Mike Abbott's Quick Shortcut Cache,
       * described here: http://oss.sgi.com/projects/apache/mod_qsc.html )
       *
       * It may have other uses as well, such as routing requests directly to
       * content handlers that have the ability to grok HTTP and do their
       * own access checking, etc (e.g. servlet engines).
       *
       * Use this hook with extreme care and only if you know what you are
       * doing.
       */
      AP_PROCESS_REQUEST_ENTRY((uintptr_t)r, r->uri);
      if (ap_extended_status) {
          ap_time_process_request(r->connection->sbh, START_PREQUEST);
      }
  
      if (APLOGrtrace4(r)) {
          int i;
          const apr_array_header_t *t_h = apr_table_elts(r->headers_in);
          const apr_table_entry_t *t_elt = (apr_table_entry_t *)t_h->elts;
          ap_log_rerror(APLOG_MARK, APLOG_TRACE4, 0, r,
                        "Headers received from client:");
          for (i = 0; i < t_h->nelts; i++, t_elt++) {
              ap_log_rerror(APLOG_MARK, APLOG_TRACE4, 0, r, "  %s: %s",
                            ap_escape_logitem(r->pool, t_elt->key),
                            ap_escape_logitem(r->pool, t_elt->val));
          }
      }
  
  #if APR_HAS_THREADS
      apr_thread_mutex_create(&r->invoke_mtx, APR_THREAD_MUTEX_DEFAULT, r->pool);
      apr_thread_mutex_lock(r->invoke_mtx);
  #endif
      access_status = ap_run_quick_handler(r, 0);  /* Not a look-up request */
      if (access_status == DECLINED) {
          access_status = ap_process_request_internal(r);
          if (access_status == OK) {
              access_status = ap_invoke_handler(r);
          }
      }
  
      if (access_status == SUSPENDED) {
          /* TODO: Should move these steps into a generic function, so modules
           * working on a suspended request can also call _ENTRY again.
           */
          AP_PROCESS_REQUEST_RETURN((uintptr_t)r, r->uri, access_status);
          if (ap_extended_status) {
              ap_time_process_request(c->sbh, STOP_PREQUEST);
          }
          if (c->cs)
              c->cs->state = CONN_STATE_SUSPENDED;
  #if APR_HAS_THREADS
          apr_thread_mutex_unlock(r->invoke_mtx);
  #endif
          return;
      }
  #if APR_HAS_THREADS
      apr_thread_mutex_unlock(r->invoke_mtx);
  #endif
  
      ap_die_r(access_status, r, HTTP_OK);
  
      ap_process_request_after_handler(r);
  }
  
  AP_DECLARE(void) ap_process_request(request_rec *r)
  {
      apr_bucket_brigade *bb;
      apr_bucket *b;
      conn_rec *c = r->connection;
      apr_status_t rv;
  
      ap_process_async_request(r);
  
      if (!c->data_in_input_filters) {
          bb = apr_brigade_create(c->pool, c->bucket_alloc);
          b = apr_bucket_flush_create(c->bucket_alloc);
          APR_BRIGADE_INSERT_HEAD(bb, b);
          rv = ap_pass_brigade(c->output_filters, bb);
          if (APR_STATUS_IS_TIMEUP(rv)) {
              /*
               * Notice a timeout as an error message. This might be
               * valuable for detecting clients with broken network
               * connections or possible DoS attacks.
               *
               * It is still safe to use r / r->pool here as the eor bucket
               * could not have been destroyed in the event of a timeout.
               */
              ap_log_rerror(APLOG_MARK, APLOG_INFO, rv, r, APLOGNO(01581)
                            "Timeout while writing data for URI %s to the"
                            " client", r->unparsed_uri);
          }
      }
      if (ap_extended_status) {
          ap_time_process_request(c->sbh, STOP_PREQUEST);
      }
  }
  
  static apr_table_t *rename_original_env(apr_pool_t *p, apr_table_t *t)
  {
      const apr_array_header_t *env_arr = apr_table_elts(t);
      const apr_table_entry_t *elts = (const apr_table_entry_t *) env_arr->elts;
      apr_table_t *new = apr_table_make(p, env_arr->nalloc);
      int i;
  
      for (i = 0; i < env_arr->nelts; ++i) {
          if (!elts[i].key)
              continue;
          apr_table_setn(new, apr_pstrcat(p, "REDIRECT_", elts[i].key, NULL),
                    elts[i].val);
      }
  
      return new;
  }
  
  static request_rec *internal_internal_redirect(const char *new_uri,
                                                 request_rec *r) {
      int access_status;
      request_rec *new;
  
      if (ap_is_recursion_limit_exceeded(r)) {
          ap_die(HTTP_INTERNAL_SERVER_ERROR, r);
          return NULL;
      }
  
      new = (request_rec *) apr_pcalloc(r->pool, sizeof(request_rec));
  
      new->connection = r->connection;
      new->server     = r->server;
      new->pool       = r->pool;
  
      /*
       * A whole lot of this really ought to be shared with http_protocol.c...
       * another missing cleanup.  It's particularly inappropriate to be
       * setting header_only, etc., here.
       */
  
      new->method          = r->method;
      new->method_number   = r->method_number;
      new->allowed_methods = ap_make_method_list(new->pool, 2);
      ap_parse_uri(new, new_uri);
      new->parsed_uri.port_str = r->parsed_uri.port_str;
      new->parsed_uri.port = r->parsed_uri.port;
  
      new->request_config = ap_create_request_config(r->pool);
  
      new->per_dir_config = r->server->lookup_defaults;
  
      new->prev = r;
      r->next   = new;
  
      new->useragent_addr = r->useragent_addr;
      new->useragent_ip = r->useragent_ip;
  
      /* Must have prev and next pointers set before calling create_request
       * hook.
       */
      ap_run_create_request(new);
  
      /* Inherit the rest of the protocol info... */
  
      new->the_request = r->the_request;
  
      new->allowed         = r->allowed;
  
      new->status          = r->status;
      new->assbackwards    = r->assbackwards;
      new->header_only     = r->header_only;
      new->protocol        = r->protocol;
      new->proto_num       = r->proto_num;
      new->hostname        = r->hostname;
      new->request_time    = r->request_time;
      new->main            = r->main;
  
      new->headers_in      = r->headers_in;
      new->trailers_in     = r->trailers_in;
      new->headers_out     = apr_table_make(r->pool, 12);
      if (ap_is_HTTP_REDIRECT(new->status)) {
          const char *location = apr_table_get(r->headers_out, "Location");
          if (location)
              apr_table_setn(new->headers_out, "Location", location);
      }
      new->err_headers_out = r->err_headers_out;
      new->trailers_out    = apr_table_make(r->pool, 5);
      new->subprocess_env  = rename_original_env(r->pool, r->subprocess_env);
      new->notes           = apr_table_make(r->pool, 5);
  
      new->htaccess        = r->htaccess;
      new->no_cache        = r->no_cache;
      new->expecting_100   = r->expecting_100;
      new->no_local_copy   = r->no_local_copy;
      new->read_length     = r->read_length;     /* We can only read it once */
      new->vlist_validator = r->vlist_validator;
  
      new->proto_output_filters  = r->proto_output_filters;
      new->proto_input_filters   = r->proto_input_filters;
  
      new->input_filters   = new->proto_input_filters;
  
      if (new->main) {
          ap_filter_t *f, *nextf;
  
          /* If this is a subrequest, the filter chain may contain a
           * mixture of filters specific to the old request (r), and
           * some inherited from r->main.  Here, inherit that filter
           * chain, and remove all those which are specific to the old
           * request; ensuring the subreq filter is left in place. */
          new->output_filters = r->output_filters;
  
          f = new->output_filters;
          do {
              nextf = f->next;
  
              if (f->r == r && f->frec != ap_subreq_core_filter_handle) {
                  ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01582)
                                "dropping filter '%s' in internal redirect from %s to %s",
                                f->frec->name, r->unparsed_uri, new_uri);
  
                  /* To remove the filter, first set f->r to the *new*
                   * request_rec, so that ->output_filters on 'new' is
                   * changed (if necessary) when removing the filter. */
                  f->r = new;
                  ap_remove_output_filter(f);
              }
  
              f = nextf;
  
              /* Stop at the protocol filters.  If a protocol filter has
               * been newly installed for this resource, better leave it
               * in place, though it's probably a misconfiguration or
               * filter bug to get into this state. */
          } while (f && f != new->proto_output_filters);
      }
      else {
          /* If this is not a subrequest, clear out all
           * resource-specific filters. */
          new->output_filters  = new->proto_output_filters;
      }
  
      update_r_in_filters(new->input_filters, r, new);
      update_r_in_filters(new->output_filters, r, new);
  
      apr_table_setn(new->subprocess_env, "REDIRECT_STATUS",
                     apr_itoa(r->pool, r->status));
  
      /* Begin by presuming any module can make its own path_info assumptions,
       * until some module interjects and changes the value.
       */
      new->used_path_info = AP_REQ_DEFAULT_PATH_INFO;
  
  #if APR_HAS_THREADS
      new->invoke_mtx = r->invoke_mtx;
  #endif
  
      /*
       * XXX: hmm.  This is because mod_setenvif and mod_unique_id really need
       * to do their thing on internal redirects as well.  Perhaps this is a
       * misnamed function.
       */
      if ((access_status = ap_run_post_read_request(new))) {
          ap_die(access_status, new);
          return NULL;
      }
  
      return new;
  }
  
  /* XXX: Is this function is so bogus and fragile that we deep-6 it? */
  AP_DECLARE(void) ap_internal_fast_redirect(request_rec *rr, request_rec *r)
  {
      /* We need to tell POOL_DEBUG that we're guaranteeing that rr->pool
       * will exist as long as r->pool.  Otherwise we run into troubles because
       * some values in this request will be allocated in r->pool, and others in
       * rr->pool.
       */
      apr_pool_join(r->pool, rr->pool);
      r->proxyreq = rr->proxyreq;
      r->no_cache = (r->no_cache && rr->no_cache);
      r->no_local_copy = (r->no_local_copy && rr->no_local_copy);
      r->mtime = rr->mtime;
      r->uri = rr->uri;
      r->filename = rr->filename;
      r->canonical_filename = rr->canonical_filename;
      r->path_info = rr->path_info;
      r->args = rr->args;
      r->finfo = rr->finfo;
      r->handler = rr->handler;
      ap_set_content_type(r, rr->content_type);
      r->content_encoding = rr->content_encoding;
      r->content_languages = rr->content_languages;
      r->per_dir_config = rr->per_dir_config;
      /* copy output headers from subrequest, but leave negotiation headers */
      r->notes = apr_table_overlay(r->pool, rr->notes, r->notes);
      r->headers_out = apr_table_overlay(r->pool, rr->headers_out,
                                         r->headers_out);
      r->err_headers_out = apr_table_overlay(r->pool, rr->err_headers_out,
                                             r->err_headers_out);
      r->trailers_out = apr_table_overlay(r->pool, rr->trailers_out,
                                             r->trailers_out);
      r->subprocess_env = apr_table_overlay(r->pool, rr->subprocess_env,
                                            r->subprocess_env);
  
      r->output_filters = rr->output_filters;
      r->input_filters = rr->input_filters;
  
      /* If any filters pointed at the now-defunct rr, we must point them
       * at our "new" instance of r.  In particular, some of rr's structures
       * will now be bogus (say rr->headers_out).  If a filter tried to modify
       * their f->r structure when it is pointing to rr, the real request_rec
       * will not get updated.  Fix that here.
       */
      update_r_in_filters(r->input_filters, rr, r);
      update_r_in_filters(r->output_filters, rr, r);
  
      if (r->main) {
          ap_filter_t *next = r->output_filters;
          while (next && (next != r->proto_output_filters)) {
              if (next->frec == ap_subreq_core_filter_handle) {
                  break;
              }
              next = next->next;
          }
          if (!next || next == r->proto_output_filters) {
              ap_add_output_filter_handle(ap_subreq_core_filter_handle,
                                          NULL, r, r->connection);
          }
      }
      else {
          /*
           * We need to check if we now have the SUBREQ_CORE filter in our filter
           * chain. If this is the case we need to remove it since we are NO
           * subrequest. But we need to keep in mind that the SUBREQ_CORE filter
           * does not necessarily need to be the first filter in our chain. So we
           * need to go through the chain. But we only need to walk up the chain
           * until the proto_output_filters as the SUBREQ_CORE filter is below the
           * protocol filters.
           */
          ap_filter_t *next;
  
          next = r->output_filters;
          while (next && (next->frec != ap_subreq_core_filter_handle)
                 && (next != r->proto_output_filters)) {
                  next = next->next;
          }
          if (next && (next->frec == ap_subreq_core_filter_handle)) {
              ap_remove_output_filter(next);
          }
      }
  }
  
  AP_DECLARE(void) ap_internal_redirect(const char *new_uri, request_rec *r)
  {
      int access_status;
      request_rec *new = internal_internal_redirect(new_uri, r);
  
      AP_INTERNAL_REDIRECT(r->uri, new_uri);
  
      /* ap_die was already called, if an error occured */
      if (!new) {
          return;
      }
  
      access_status = ap_run_quick_handler(new, 0);  /* Not a look-up request */
      if (access_status == DECLINED) {
          access_status = ap_process_request_internal(new);
          if (access_status == OK) {
              access_status = ap_invoke_handler(new);
          }
      }
      ap_die(access_status, new);
  }
  
  /* This function is designed for things like actions or CGI scripts, when
   * using AddHandler, and you want to preserve the content type across
   * an internal redirect.
   */
  AP_DECLARE(void) ap_internal_redirect_handler(const char *new_uri, request_rec *r)
  {
      int access_status;
      request_rec *new = internal_internal_redirect(new_uri, r);
  
      /* ap_die was already called, if an error occured */
      if (!new) {
          return;
      }
  
      if (r->handler)
          ap_set_content_type(new, r->content_type);
      access_status = ap_process_request_internal(new);
      if (access_status == OK) {
          access_status = ap_invoke_handler(new);
      }
      ap_die(access_status, new);
  }
  
  AP_DECLARE(void) ap_allow_methods(request_rec *r, int reset, ...)
  {
      const char *method;
      va_list methods;
  
      /*
       * Get rid of any current settings if requested; not just the
       * well-known methods but any extensions as well.
       */
      if (reset) {
          ap_clear_method_list(r->allowed_methods);
      }
  
      va_start(methods, reset);
      while ((method = va_arg(methods, const char *)) != NULL) {
          ap_method_list_add(r->allowed_methods, method);
      }
      va_end(methods);
  }
  
  AP_DECLARE(void) ap_allow_standard_methods(request_rec *r, int reset, ...)
  {
      int method;
      va_list methods;
      apr_int64_t mask;
  
      /*
       * Get rid of any current settings if requested; not just the
       * well-known methods but any extensions as well.
       */
      if (reset) {
          ap_clear_method_list(r->allowed_methods);
      }
  
      mask = 0;
      va_start(methods, reset);
      while ((method = va_arg(methods, int)) != -1) {
          mask |= (AP_METHOD_BIT << method);
      }
      va_end(methods);
  
      r->allowed_methods->method_mask |= mask;
  }
  