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.
   */
  
  /*
   * protocol.c --- routines which directly communicate with the client.
   *
   * Code originally by Rob McCool; much redone by Robert S. Thau
   * and the Apache Software Foundation.
   */
  
  #include "apr.h"
  #include "apr_strings.h"
  #include "apr_buckets.h"
  #include "apr_lib.h"
  #include "apr_signal.h"
  #include "apr_strmatch.h"
  
  #define APR_WANT_STDIO          /* for sscanf */
  #define APR_WANT_STRFUNC
  #define APR_WANT_MEMFUNC
  #include "apr_want.h"
  
  #include "util_filter.h"
  #include "ap_config.h"
  #include "httpd.h"
  #include "http_config.h"
  #include "http_core.h"
  #include "http_protocol.h"
  #include "http_main.h"
  #include "http_request.h"
  #include "http_vhost.h"
  #include "http_log.h"           /* For errors detected in basic auth common
                                   * support code... */
  #include "mod_core.h"
  #include "util_charset.h"
  #include "util_ebcdic.h"
  #include "scoreboard.h"
  
  #if APR_HAVE_STDARG_H
  #include <stdarg.h>
  #endif
  #if APR_HAVE_UNISTD_H
  #include <unistd.h>
  #endif
  
  /* we know core's module_index is 0 */
  #undef APLOG_MODULE_INDEX
  #define APLOG_MODULE_INDEX AP_CORE_MODULE_INDEX
  
  APR_HOOK_STRUCT(
      APR_HOOK_LINK(pre_read_request)
      APR_HOOK_LINK(post_read_request)
      APR_HOOK_LINK(log_transaction)
      APR_HOOK_LINK(http_scheme)
      APR_HOOK_LINK(default_port)
      APR_HOOK_LINK(note_auth_failure)
      APR_HOOK_LINK(protocol_propose)
      APR_HOOK_LINK(protocol_switch)
      APR_HOOK_LINK(protocol_get)
      APR_HOOK_LINK(ssl_conn_is_ssl)
      APR_HOOK_LINK(ssl_var_lookup)
      APR_HOOK_LINK(ssl_add_cert_files) 
      APR_HOOK_LINK(ssl_add_fallback_cert_files) 
      APR_HOOK_LINK(ssl_answer_challenge) 
  )
  
  AP_DECLARE_DATA ap_filter_rec_t *ap_old_write_func = NULL;
  
  
  /* Patterns to match in ap_make_content_type() */
  static const char *needcset[] = {
      "text/plain",
      "text/html",
      NULL
  };
  static const apr_strmatch_pattern **needcset_patterns;
  static const apr_strmatch_pattern *charset_pattern;
  
  AP_DECLARE(void) ap_setup_make_content_type(apr_pool_t *pool)
  {
      int i;
      for (i = 0; needcset[i]; i++) {
          continue;
      }
      needcset_patterns = (const apr_strmatch_pattern **)
          apr_palloc(pool, (i + 1) * sizeof(apr_strmatch_pattern *));
      for (i = 0; needcset[i]; i++) {
          needcset_patterns[i] = apr_strmatch_precompile(pool, needcset[i], 0);
      }
      needcset_patterns[i] = NULL;
      charset_pattern = apr_strmatch_precompile(pool, "charset=", 0);
  }
  
  /*
   * Builds the content-type that should be sent to the client from the
   * content-type specified.  The following rules are followed:
   *    - if type is NULL or "", return NULL (do not set content-type).
   *    - if charset adding is disabled, stop processing and return type.
   *    - then, if there are no parameters on type, add the default charset
   *    - return type
   */
  AP_DECLARE(const char *)ap_make_content_type(request_rec *r, const char *type)
  {
      const apr_strmatch_pattern **pcset;
      core_dir_config *conf =
          (core_dir_config *)ap_get_core_module_config(r->per_dir_config);
      core_request_config *request_conf;
      apr_size_t type_len;
  
      if (!type || *type == '\0') {
          return NULL;
      }
  
      if (conf->add_default_charset != ADD_DEFAULT_CHARSET_ON) {
          return type;
      }
  
      request_conf = ap_get_core_module_config(r->request_config);
      if (request_conf->suppress_charset) {
          return type;
      }
  
      type_len = strlen(type);
  
      if (apr_strmatch(charset_pattern, type, type_len) != NULL) {
          /* already has parameter, do nothing */
          /* XXX we don't check the validity */
          ;
      }
      else {
          /* see if it makes sense to add the charset. At present,
           * we only add it if the Content-type is one of needcset[]
           */
          for (pcset = needcset_patterns; *pcset ; pcset++) {
              if (apr_strmatch(*pcset, type, type_len) != NULL) {
                  struct iovec concat[3];
                  concat[0].iov_base = (void *)type;
                  concat[0].iov_len = type_len;
                  concat[1].iov_base = (void *)"; charset=";
                  concat[1].iov_len = sizeof("; charset=") - 1;
                  concat[2].iov_base = (void *)(conf->add_default_charset_name);
                  concat[2].iov_len = strlen(conf->add_default_charset_name);
                  type = apr_pstrcatv(r->pool, concat, 3, NULL);
                  break;
              }
          }
      }
  
      return type;
  }
  
  AP_DECLARE(void) ap_set_content_length(request_rec *r, apr_off_t clength)
  {
      r->clength = clength;
      apr_table_setn(r->headers_out, "Content-Length",
                     apr_off_t_toa(r->pool, clength));
  }
  
  /*
   * Return the latest rational time from a request/mtime (modification time)
   * pair.  We return the mtime unless it's in the future, in which case we
   * return the current time.  We use the request time as a reference in order
   * to limit the number of calls to time().  We don't check for futurosity
   * unless the mtime is at least as new as the reference.
   */
  AP_DECLARE(apr_time_t) ap_rationalize_mtime(request_rec *r, apr_time_t mtime)
  {
      apr_time_t now;
  
      /* For all static responses, it's almost certain that the file was
       * last modified before the beginning of the request.  So there's
       * no reason to call time(NULL) again.  But if the response has been
       * created on demand, then it might be newer than the time the request
       * started.  In this event we really have to call time(NULL) again
       * so that we can give the clients the most accurate Last-Modified.  If we
       * were given a time in the future, we return the current time - the
       * Last-Modified can't be in the future.
       */
      now = (mtime < r->request_time) ? r->request_time : apr_time_now();
      return (mtime > now) ? now : mtime;
  }
  
  /* Get a line from an input filter, including any continuation lines
   * caused by MIME folding (or broken clients) if fold != 0, and place it
   * in the buffer s, of size n bytes, without the ending newline.
   *
   * If s is NULL, ap_fgetline_core will allocate necessary memory from p.
   *
   * Returns APR_SUCCESS if there are no problems and sets *read to be
   * the full length of s.
   *
   * APR_ENOSPC is returned if there is not enough buffer space.
   * Other errors may be returned on other errors.
   *
   * The [CR]LF are *not* returned in the buffer.  Therefore, a *read of 0
   * indicates that an empty line was read.
   *
   * Notes: Because the buffer uses 1 char for NUL, the most we can return is
   *        (n - 1) actual characters.
   *
   *        If no LF is detected on the last line due to a dropped connection
   *        or a full buffer, that's considered an error.
   */
  static apr_status_t ap_fgetline_core(char **s, apr_size_t n,
                                       apr_size_t *read, ap_filter_t *f,
                                       int flags, apr_bucket_brigade *bb,
                                       apr_pool_t *p)
  {
      apr_status_t rv;
      apr_bucket *e;
      apr_size_t bytes_handled = 0, current_alloc = 0;
      char *pos, *last_char = *s;
      int do_alloc = (*s == NULL), saw_eos = 0;
      int fold = flags & AP_GETLINE_FOLD;
      int crlf = flags & AP_GETLINE_CRLF;
      int nospc_eol = flags & AP_GETLINE_NOSPC_EOL;
      int saw_eol = 0, saw_nospc = 0;
      apr_read_type_e block;
  
      if (!n) {
          /* Needs room for NUL byte at least */
          *read = 0;
          return APR_BADARG;
      }
  
      block = (flags & AP_GETLINE_NONBLOCK) ? APR_NONBLOCK_READ
                                            : APR_BLOCK_READ;
  
      /*
       * Initialize last_char as otherwise a random value will be compared
       * against APR_ASCII_LF at the end of the loop if bb only contains
       * zero-length buckets.
       */
      if (last_char)
          *last_char = '\0';
  
      do {
          apr_brigade_cleanup(bb);
          rv = ap_get_brigade(f, bb, AP_MODE_GETLINE, block, 0);
          if (rv != APR_SUCCESS) {
              goto cleanup;
          }
  
          /* Something horribly wrong happened.  Someone didn't block! 
           * (this also happens at the end of each keepalive connection)
           * (this also happens when non-blocking is asked too, not that wrong)
           */
          if (APR_BRIGADE_EMPTY(bb)) {
              if (block != APR_NONBLOCK_READ) {
                  rv = APR_EGENERAL;
              }
              else {
                  rv = APR_EAGAIN;
              }
              goto cleanup;
          }
  
          for (e = APR_BRIGADE_FIRST(bb);
               e != APR_BRIGADE_SENTINEL(bb);
               e = APR_BUCKET_NEXT(e))
          {
              const char *str;
              apr_size_t len;
  
              /* If we see an EOS, don't bother doing anything more. */
              if (APR_BUCKET_IS_EOS(e)) {
                  saw_eos = 1;
                  break;
              }
  
              rv = apr_bucket_read(e, &str, &len, APR_BLOCK_READ);
              if (rv != APR_SUCCESS) {
                  goto cleanup;
              }
  
              if (len == 0) {
                  /* no use attempting a zero-byte alloc (hurts when
                   * using --with-efence --enable-pool-debug) or
                   * doing any of the other logic either
                   */
                  continue;
              }
  
              /* Would this overrun our buffer?  If so, we'll die. */
              if (n < bytes_handled + len) {
                  /* Before we die, let's fill the buffer up to its limit (i.e.
                   * fall through with the remaining length, if any), setting
                   * saw_eol on LF to stop the outer loop appropriately; we may
                   * come back here once the buffer is filled (no LF seen), and
                   * either be done at that time or continue to wait for LF here
                   * if nospc_eol is set.
                   *
                   * But there is also a corner cases which we want to address,
                   * namely if the buffer is overrun by the final LF only (i.e.
                   * the CR fits in); this is not really an overrun since we'll
                   * strip the CR finally (and use it for NUL byte), but anyway
                   * we have to handle the case so that it's not returned to the
                   * caller as part of the truncated line (it's not!). This is
                   * easier to consider that LF is out of counting and thus fall
                   * through with no error (saw_eol is set to 2 so that we later
                   * ignore LF handling already done here), while folding and
                   * nospc_eol logics continue to work (or fail) appropriately.
                   */
                  saw_eol = (str[len - 1] == APR_ASCII_LF);
                  if (/* First time around */
                      saw_eol && !saw_nospc
                      /*  Single LF completing the buffered CR, */
                      && ((len == 1 && ((*s)[bytes_handled - 1] == APR_ASCII_CR))
                      /*  or trailing CRLF overuns by LF only */
                          || (len > 1 && str[len - 2] == APR_ASCII_CR
                              && n - bytes_handled + 1 == len))) {
                      /* In both cases *last_char is (to be) the CR stripped by
                       * later 'bytes_handled = last_char - *s'.
                       */
                      saw_eol = 2;
                  }
                  else {
                      /* In any other case we'd lose data. */
                      rv = APR_ENOSPC;
                      saw_nospc = 1;
                  }
                  len = n - bytes_handled;
                  if (!len) {
                      if (saw_eol) {
                          break;
                      }
                      if (nospc_eol) {
                          continue;
                      }
                      goto cleanup;
                  }
              }
  
              /* Do we have to handle the allocation ourselves? */
              if (do_alloc) {
                  /* We'll assume the common case where one bucket is enough. */
                  if (!*s) {
                      current_alloc = len;
                      *s = apr_palloc(p, current_alloc + 1);
                  }
                  else if (bytes_handled + len > current_alloc) {
                      /* Increase the buffer size */
                      apr_size_t new_size = current_alloc * 2;
                      char *new_buffer;
  
                      if (bytes_handled + len > new_size) {
                          new_size = (bytes_handled + len) * 2;
                      }
  
                      new_buffer = apr_palloc(p, new_size + 1);
  
                      /* Copy what we already had. */
                      memcpy(new_buffer, *s, bytes_handled);
                      current_alloc = new_size;
                      *s = new_buffer;
                  }
              }
  
              /* Just copy the rest of the data to the end of the old buffer. */
              pos = *s + bytes_handled;
              memcpy(pos, str, len);
              last_char = pos + len - 1;
  
              /* We've now processed that new data - update accordingly. */
              bytes_handled += len;
          }
  
          /* If we got a full line of input, stop reading */
          if (last_char && (*last_char == APR_ASCII_LF)) {
              saw_eol = 1;
          }
      } while (!saw_eol);
  
      if (rv != APR_SUCCESS) {
          /* End of line after APR_ENOSPC above */
          goto cleanup;
      }
  
      /* Now terminate the string at the end of the line;
       * if the last-but-one character is a CR, terminate there.
       * LF is handled above (not accounted) when saw_eol == 2,
       * the last char is CR to terminate at still.
       */
      if (saw_eol < 2) {
          if (last_char > *s && last_char[-1] == APR_ASCII_CR) {
              last_char--;
          }
          else if (crlf) {
              rv = APR_EINVAL;
              goto cleanup;
          }
      }
      bytes_handled = last_char - *s;
  
      /* If we're folding, we have more work to do.
       *
       * Note that if an EOS was seen, we know we can't have another line.
       */
      if (fold && bytes_handled && !saw_eos) {
          for (;;) {
              const char *str;
              apr_size_t len;
              char c;
  
              /* Clear the temp brigade for this filter read. */
              apr_brigade_cleanup(bb);
  
              /* We only care about the first byte. */
              rv = ap_get_brigade(f, bb, AP_MODE_SPECULATIVE, block, 1);
              if (rv != APR_SUCCESS) {
                  goto cleanup;
              }
  
              if (APR_BRIGADE_EMPTY(bb)) {
                  break;
              }
  
              e = APR_BRIGADE_FIRST(bb);
  
              /* If we see an EOS, don't bother doing anything more. */
              if (APR_BUCKET_IS_EOS(e)) {
                  break;
              }
  
              rv = apr_bucket_read(e, &str, &len, APR_BLOCK_READ);
              if (rv != APR_SUCCESS) {
                  apr_brigade_cleanup(bb);
                  goto cleanup;
              }
  
              /* Found one, so call ourselves again to get the next line.
               *
               * FIXME: If the folding line is completely blank, should we
               * stop folding?  Does that require also looking at the next
               * char?
               */
              /* When we call destroy, the buckets are deleted, so save that
               * one character we need.  This simplifies our execution paths
               * at the cost of one character read.
               */
              c = *str;
              if (c == APR_ASCII_BLANK || c == APR_ASCII_TAB) {
                  /* Do we have enough space? We may be full now. */
                  if (bytes_handled >= n) {
                      rv = APR_ENOSPC;
                      goto cleanup;
                  }
                  else {
                      apr_size_t next_size, next_len;
                      char *tmp;
  
                      /* If we're doing the allocations for them, we have to
                       * give ourselves a NULL and copy it on return.
                       */
                      if (do_alloc) {
                          tmp = NULL;
                      }
                      else {
                          tmp = last_char;
                      }
  
                      next_size = n - bytes_handled;
  
                      rv = ap_fgetline_core(&tmp, next_size, &next_len, f,
                                            flags & ~AP_GETLINE_FOLD, bb, p);
                      if (rv != APR_SUCCESS) {
                          goto cleanup;
                      }
  
                      if (do_alloc && next_len > 0) {
                          char *new_buffer;
                          apr_size_t new_size = bytes_handled + next_len + 1;
  
                          /* we need to alloc an extra byte for a null */
                          new_buffer = apr_palloc(p, new_size);
  
                          /* Copy what we already had. */
                          memcpy(new_buffer, *s, bytes_handled);
  
                          /* copy the new line, including the trailing null */
                          memcpy(new_buffer + bytes_handled, tmp, next_len);
                          *s = new_buffer;
                      }
  
                      last_char += next_len;
                      bytes_handled += next_len;
                  }
              }
              else { /* next character is not tab or space */
                  break;
              }
          }
      }
  
  cleanup:
      if (bytes_handled >= n) {
          bytes_handled = n - 1;
      }
  
      *read = bytes_handled;
      if (*s) {
          /* ensure the string is NUL terminated */
          (*s)[*read] = '\0';
  
          /* PR#43039: We shouldn't accept NULL bytes within the line */
          bytes_handled = strlen(*s);
          if (bytes_handled < *read) {
              *read = bytes_handled;
              if (rv == APR_SUCCESS) {
                  rv = APR_EINVAL;
              }
          }
      }
      return rv;
  }
  
  AP_DECLARE(apr_status_t) ap_fgetline(char **s, apr_size_t n,
                                       apr_size_t *read, ap_filter_t *f,
                                       int flags, apr_bucket_brigade *bb,
                                       apr_pool_t *p)
  {
      apr_status_t rv;
      
      rv = ap_fgetline_core(s, n, read, f, flags, bb, p);
  
  #if APR_CHARSET_EBCDIC
      /* On EBCDIC boxes, each complete http protocol input line needs to be
       * translated into the code page used by the compiler.  Since
       * ap_fgetline_core uses recursion, we do the translation in a wrapper
       * function to ensure that each input character gets translated only once.
       */
      if (*read) {
          ap_xlate_proto_from_ascii(*s, *read);
      }
  #endif
  
      return rv;
  }
  
  /* Same as ap_fgetline(), working on r's pool and protocol input filters.
   * Pulls from r->proto_input_filters instead of r->input_filters for
   * stricter protocol adherence and better input filter behavior during
   * chunked trailer processing (for http).
   */
  AP_DECLARE(apr_status_t) ap_rgetline(char **s, apr_size_t n,
                                       apr_size_t *read, request_rec *r,
                                       int flags, apr_bucket_brigade *bb)
  {
      apr_status_t rv;
  
      rv = ap_fgetline_core(s, n, read, r->proto_input_filters, flags,
                            bb, r->pool);
  #if APR_CHARSET_EBCDIC
      /* On EBCDIC boxes, each complete http protocol input line needs to be
       * translated into the code page used by the compiler.  Since
       * ap_fgetline_core uses recursion, we do the translation in a wrapper
       * function to ensure that each input character gets translated only once.
       */
      if (*read) {
          ap_xlate_proto_from_ascii(*s, *read);
      }
  #endif
  
      return rv;
  }
  
  AP_DECLARE(int) ap_getline(char *s, int n, request_rec *r, int flags)
  {
      apr_status_t rv;
      apr_size_t len;
      apr_bucket_brigade *tmp_bb;
  
      if (n < 1) {
          /* Can't work since we always NUL terminate */
          return -1;
      }
  
      tmp_bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
      rv = ap_rgetline(&s, n, &len, r, flags, tmp_bb);
      apr_brigade_destroy(tmp_bb);
  
      /* Map the out-of-space condition to the old API. */
      if (rv == APR_ENOSPC) {
          return n;
      }
  
      /* Anything else is just bad. */
      if (rv != APR_SUCCESS) {
          return -1;
      }
  
      return (int)len;
  }
  
  /* parse_uri: break apart the uri
   * Side Effects:
   * - sets r->args to rest after '?' (or NULL if no '?')
   * - sets r->uri to request uri (without r->args part)
   * - sets r->hostname (if not set already) from request (scheme://host:port)
   */
  AP_CORE_DECLARE(void) ap_parse_uri(request_rec *r, const char *uri)
  {
      int status = HTTP_OK;
  
      r->unparsed_uri = apr_pstrdup(r->pool, uri);
  
      /* http://issues.apache.org/bugzilla/show_bug.cgi?id=31875
       * http://issues.apache.org/bugzilla/show_bug.cgi?id=28450
       *
       * This is not in fact a URI, it's a path.  That matters in the
       * case of a leading double-slash.  We need to resolve the issue
       * by normalizing that out before treating it as a URI.
       */
      while ((uri[0] == '/') && (uri[1] == '/')) {
          ++uri ;
      }
      if (r->method_number == M_CONNECT) {
          status = apr_uri_parse_hostinfo(r->pool, uri, &r->parsed_uri);
      }
      else {
          status = apr_uri_parse(r->pool, uri, &r->parsed_uri);
      }
  
      if (status == APR_SUCCESS) {
          /* if it has a scheme we may need to do absoluteURI vhost stuff */
          if (r->parsed_uri.scheme
              && !ap_cstr_casecmp(r->parsed_uri.scheme, ap_http_scheme(r))) {
              r->hostname = r->parsed_uri.hostname;
          }
          else if (r->method_number == M_CONNECT) {
              r->hostname = r->parsed_uri.hostname;
          }
  
          r->args = r->parsed_uri.query;
          if (r->parsed_uri.path) {
              r->uri = r->parsed_uri.path;
          }
          else if (r->method_number == M_OPTIONS) {
              r->uri = apr_pstrdup(r->pool, "*");
          }
          else {
              r->uri = apr_pstrdup(r->pool, "/");
          }
  
  #if defined(OS2) || defined(WIN32)
          /* Handle path translations for OS/2 and plug security hole.
           * This will prevent "http://www.wherever.com/..\..\/" from
           * returning a directory for the root drive.
           */
          {
              char *x;
  
              for (x = r->uri; (x = strchr(x, '\\')) != NULL; )
                  *x = '/';
          }
  #endif /* OS2 || WIN32 */
      }
      else {
          r->args = NULL;
          r->hostname = NULL;
          r->status = HTTP_BAD_REQUEST;             /* set error status */
          r->uri = apr_pstrdup(r->pool, uri);
      }
  }
  
  /* get the length of the field name for logging, but no more than 80 bytes */
  #define LOG_NAME_MAX_LEN 80
  static int field_name_len(const char *field)
  {
      const char *end = ap_strchr_c(field, ':');
      if (end == NULL || end - field > LOG_NAME_MAX_LEN)
          return LOG_NAME_MAX_LEN;
      return end - field;
  }
  
  static int read_request_line(request_rec *r, apr_bucket_brigade *bb)
  {
      apr_size_t len;
      int num_blank_lines = DEFAULT_LIMIT_BLANK_LINES;
      core_server_config *conf = ap_get_core_module_config(r->server->module_config);
      int strict = (conf->http_conformance != AP_HTTP_CONFORMANCE_UNSAFE);
  
      /* Read past empty lines until we get a real request line,
       * a read error, the connection closes (EOF), or we timeout.
       *
       * We skip empty lines because browsers have to tack a CRLF on to the end
       * of POSTs to support old CERN webservers.  But note that we may not
       * have flushed any previous response completely to the client yet.
       * We delay the flush as long as possible so that we can improve
       * performance for clients that are pipelining requests.  If a request
       * is pipelined then we won't block during the (implicit) read() below.
       * If the requests aren't pipelined, then the client is still waiting
       * for the final buffer flush from us, and we will block in the implicit
       * read().  B_SAFEREAD ensures that the BUFF layer flushes if it will
       * have to block during a read.
       */
  
      do {
          apr_status_t rv;
  
          /* ensure ap_rgetline allocates memory each time thru the loop
           * if there are empty lines
           */
          r->the_request = NULL;
          rv = ap_rgetline(&(r->the_request), (apr_size_t)(r->server->limit_req_line + 2),
                           &len, r, strict ? AP_GETLINE_CRLF : 0, bb);
  
          if (rv != APR_SUCCESS) {
              r->request_time = apr_time_now();
  
              /* ap_rgetline returns APR_ENOSPC if it fills up the
               * buffer before finding the end-of-line.  This is only going to
               * happen if it exceeds the configured limit for a request-line.
               */
              if (APR_STATUS_IS_ENOSPC(rv)) {
                  r->status = HTTP_REQUEST_URI_TOO_LARGE;
              }
              else if (APR_STATUS_IS_TIMEUP(rv)) {
                  r->status = HTTP_REQUEST_TIME_OUT;
              }
              else if (APR_STATUS_IS_BADARG(rv)) {
                  r->status = HTTP_BAD_REQUEST;
              }
              else if (APR_STATUS_IS_EINVAL(rv)) {
                  r->status = HTTP_BAD_REQUEST;
              }
              r->proto_num = HTTP_VERSION(1,0);
              r->protocol  = "HTTP/1.0";
              return 0;
          }
      } while ((len <= 0) && (--num_blank_lines >= 0));
  
      if (APLOGrtrace5(r)) {
          ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, r,
                        "Request received from client: %s",
                        ap_escape_logitem(r->pool, r->the_request));
      }
  
      r->request_time = apr_time_now();
      return 1;
  }
  
  AP_DECLARE(int) ap_parse_request_line(request_rec *r)
  {
      core_server_config *conf = ap_get_core_module_config(r->server->module_config);
      int strict = (conf->http_conformance != AP_HTTP_CONFORMANCE_UNSAFE);
      enum {
          rrl_none, rrl_badmethod, rrl_badwhitespace, rrl_excesswhitespace,
          rrl_missinguri, rrl_baduri, rrl_badprotocol, rrl_trailingtext,
          rrl_badmethod09, rrl_reject09
      } deferred_error = rrl_none;
      apr_size_t len = 0;
      char *uri, *ll;
  
      r->method = r->the_request;
  
      /* If there is whitespace before a method, skip it and mark in error */
      if (apr_isspace(*r->method)) {
          deferred_error = rrl_badwhitespace; 
          for ( ; apr_isspace(*r->method); ++r->method)
              ; 
      }
  
      /* Scan the method up to the next whitespace, ensure it contains only
       * valid http-token characters, otherwise mark in error
       */
      if (strict) {
          ll = (char*) ap_scan_http_token(r->method);
      }
      else {
          ll = (char*) ap_scan_vchar_obstext(r->method);
      }
  
      if (((ll == r->method) || (*ll && !apr_isspace(*ll)))
              && deferred_error == rrl_none) {
          deferred_error = rrl_badmethod;
          ll = strpbrk(ll, "\t\n\v\f\r ");
      }
  
      /* Verify method terminated with a single SP, or mark as specific error */
      if (!ll) {
          if (deferred_error == rrl_none)
              deferred_error = rrl_missinguri;
          r->protocol = uri = "";
          goto rrl_done;
      }
      else if (strict && ll[0] && apr_isspace(ll[1])
               && deferred_error == rrl_none) {
          deferred_error = rrl_excesswhitespace; 
      }
  
      /* Advance uri pointer over leading whitespace, NUL terminate the method
       * If non-SP whitespace is encountered, mark as specific error
       */
      for (uri = ll; apr_isspace(*uri); ++uri) 
          if (*uri != ' ' && deferred_error == rrl_none)
              deferred_error = rrl_badwhitespace; 
      *ll = '\0';
  
      if (!*uri && deferred_error == rrl_none)
          deferred_error = rrl_missinguri;
  
      /* Scan the URI up to the next whitespace, ensure it contains no raw
       * control characters, otherwise mark in error
       */
      ll = (char*) ap_scan_vchar_obstext(uri);
      if (ll == uri || (*ll && !apr_isspace(*ll))) {
          deferred_error = rrl_baduri;
          ll = strpbrk(ll, "\t\n\v\f\r ");
      }
  
      /* Verify URI terminated with a single SP, or mark as specific error */
      if (!ll) {
          r->protocol = "";
          goto rrl_done;
      }
      else if (strict && ll[0] && apr_isspace(ll[1])
               && deferred_error == rrl_none) {
          deferred_error = rrl_excesswhitespace; 
      }
  
      /* Advance protocol pointer over leading whitespace, NUL terminate the uri
       * If non-SP whitespace is encountered, mark as specific error
       */
      for (r->protocol = ll; apr_isspace(*r->protocol); ++r->protocol) 
          if (*r->protocol != ' ' && deferred_error == rrl_none)
              deferred_error = rrl_badwhitespace; 
      *ll = '\0';
  
      /* Scan the protocol up to the next whitespace, validation comes later */
      if (!(ll = (char*) ap_scan_vchar_obstext(r->protocol))) {
          len = strlen(r->protocol);
          goto rrl_done;
      }
      len = ll - r->protocol;
  
      /* Advance over trailing whitespace, if found mark in error,
       * determine if trailing text is found, unconditionally mark in error,
       * finally NUL terminate the protocol string
       */
      if (*ll && !apr_isspace(*ll)) {
          deferred_error = rrl_badprotocol;
      }
      else if (strict && *ll) {
          deferred_error = rrl_excesswhitespace;
      }
      else {
          for ( ; apr_isspace(*ll); ++ll)
              if (*ll != ' ' && deferred_error == rrl_none)
                  deferred_error = rrl_badwhitespace; 
          if (*ll && deferred_error == rrl_none)
              deferred_error = rrl_trailingtext;
      }
      *((char *)r->protocol + len) = '\0';
  
  rrl_done:
      /* For internal integrity and palloc efficiency, reconstruct the_request
       * in one palloc, using only single SP characters, per spec.
       */
      r->the_request = apr_pstrcat(r->pool, r->method, *uri ? " " : NULL, uri,
                                   *r->protocol ? " " : NULL, r->protocol, NULL);
  
      if (len == 8
              && r->protocol[0] == 'H' && r->protocol[1] == 'T'
              && r->protocol[2] == 'T' && r->protocol[3] == 'P'
              && r->protocol[4] == '/' && apr_isdigit(r->protocol[5])
              && r->protocol[6] == '.' && apr_isdigit(r->protocol[7])
              && r->protocol[5] != '0') {
          r->assbackwards = 0;
          r->proto_num = HTTP_VERSION(r->protocol[5] - '0', r->protocol[7] - '0');
      }
      else if (len == 8
                   && (r->protocol[0] == 'H' || r->protocol[0] == 'h')
                   && (r->protocol[1] == 'T' || r->protocol[1] == 't')
                   && (r->protocol[2] == 'T' || r->protocol[2] == 't')
                   && (r->protocol[3] == 'P' || r->protocol[3] == 'p')
                   && r->protocol[4] == '/' && apr_isdigit(r->protocol[5])
                   && r->protocol[6] == '.' && apr_isdigit(r->protocol[7])
                   && r->protocol[5] != '0') {
          r->assbackwards = 0;
          r->proto_num = HTTP_VERSION(r->protocol[5] - '0', r->protocol[7] - '0');
          if (strict && deferred_error == rrl_none)
              deferred_error = rrl_badprotocol;
          else
              memcpy((char*)r->protocol, "HTTP", 4);
      }
      else if (r->protocol[0]) {
          r->proto_num = HTTP_VERSION(0, 9);
          /* Defer setting the r->protocol string till error msg is composed */
          if (deferred_error == rrl_none)
              deferred_error = rrl_badprotocol;
      }
      else {
          r->assbackwards = 1;
          r->protocol = "HTTP/0.9";
          r->proto_num = HTTP_VERSION(0, 9);
      }
  
      /* Determine the method_number and parse the uri prior to invoking error
       * handling, such that these fields are available for substitution
       */
      r->method_number = ap_method_number_of(r->method);
      if (r->method_number == M_GET && r->method[0] == 'H')
          r->header_only = 1;
  
      ap_parse_uri(r, uri);
      if (r->status == HTTP_OK
              && (r->parsed_uri.path != NULL)
              && (r->parsed_uri.path[0] != '/')
              && (r->method_number != M_OPTIONS
                  || strcmp(r->parsed_uri.path, "*") != 0)) {
          /* Invalid request-target per RFC 7230 section 5.3 */
          r->status = HTTP_BAD_REQUEST;
      }
  
      /* With the request understood, we can consider HTTP/0.9 specific errors */
      if (r->proto_num == HTTP_VERSION(0, 9) && deferred_error == rrl_none) {
          if (conf->http09_enable == AP_HTTP09_DISABLE)
              deferred_error = rrl_reject09;
          else if (strict && (r->method_number != M_GET || r->header_only))
              deferred_error = rrl_badmethod09;
      }
  
      /* Now that the method, uri and protocol are all processed,
       * we can safely resume any deferred error reporting
       */
      if (deferred_error != rrl_none) {
          if (deferred_error == rrl_badmethod)
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03445)
                            "HTTP Request Line; Invalid method token: '%.*s'",
                            field_name_len(r->method), r->method);
          else if (deferred_error == rrl_badmethod09)
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03444)
                            "HTTP Request Line; Invalid method token: '%.*s'"
                            " (only GET is allowed for HTTP/0.9 requests)",
                            field_name_len(r->method), r->method);
          else if (deferred_error == rrl_missinguri)
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03446)
                            "HTTP Request Line; Missing URI");
          else if (deferred_error == rrl_baduri)
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03454)
                            "HTTP Request Line; URI incorrectly encoded: '%.*s'",
                            field_name_len(r->unparsed_uri), r->unparsed_uri);
          else if (deferred_error == rrl_badwhitespace)
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03447)
                            "HTTP Request Line; Invalid whitespace");
          else if (deferred_error == rrl_excesswhitespace)
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03448)
                            "HTTP Request Line; Excess whitespace "
                            "(disallowed by HttpProtocolOptions Strict)");
          else if (deferred_error == rrl_trailingtext)
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03449)
                            "HTTP Request Line; Extraneous text found '%.*s' "
                            "(perhaps whitespace was injected?)",
                            field_name_len(ll), ll);
          else if (deferred_error == rrl_reject09)
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02401)
                            "HTTP Request Line; Rejected HTTP/0.9 request");
          else if (deferred_error == rrl_badprotocol)
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02418)
                            "HTTP Request Line; Unrecognized protocol '%.*s' "
                            "(perhaps whitespace was injected?)",
                            field_name_len(r->protocol), r->protocol);
          r->status = HTTP_BAD_REQUEST;
          goto rrl_failed;
      }
  
      if (conf->http_methods == AP_HTTP_METHODS_REGISTERED
              && r->method_number == M_INVALID) {
          ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02423)
                        "HTTP Request Line; Unrecognized HTTP method: '%.*s' "
                        "(disallowed by RegisteredMethods)",
                        field_name_len(r->method), r->method);
          r->status = HTTP_NOT_IMPLEMENTED;
          /* This can't happen in an HTTP/0.9 request, we verified GET above */
          return 0;
      }
  
      if (r->status != HTTP_OK) {
          ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03450)
                        "HTTP Request Line; Unable to parse URI: '%.*s'",
                        field_name_len(r->uri), r->uri);
          goto rrl_failed;
      }
  
      if (strict) {
          if (r->parsed_uri.fragment) {
              /* RFC3986 3.5: no fragment */
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02421)
                            "HTTP Request Line; URI must not contain a fragment");
              r->status = HTTP_BAD_REQUEST;
              goto rrl_failed;
          }
          if (r->parsed_uri.user || r->parsed_uri.password) {
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02422)
                            "HTTP Request Line; URI must not contain a "
                            "username/password");
              r->status = HTTP_BAD_REQUEST;
              goto rrl_failed;
          }
      }
  
      return 1;
  
  rrl_failed:
      if (r->proto_num == HTTP_VERSION(0, 9)) {
          /* Send all parsing and protocol error response with 1.x behavior,
           * and reserve 505 errors for actual HTTP protocols presented.
           * As called out in RFC7230 3.5, any errors parsing the protocol
           * from the request line are nearly always misencoded HTTP/1.x
           * requests. Only a valid 0.9 request with no parsing errors
           * at all may be treated as a simple request, if allowed.
           */
          r->assbackwards = 0;
          r->connection->keepalive = AP_CONN_CLOSE;
          r->proto_num = HTTP_VERSION(1, 0);
          r->protocol  = "HTTP/1.0";
      }
      return 0;
  }
  
  AP_DECLARE(int) ap_check_request_header(request_rec *r)
  {
      core_server_config *conf;
      int strict_host_check;
      const char *expect;
      int access_status;
  
      conf = ap_get_core_module_config(r->server->module_config);
  
      /* update what we think the virtual host is based on the headers we've
       * now read. may update status.
       */
      strict_host_check = (conf->strict_host_check == AP_CORE_CONFIG_ON);
      access_status = ap_update_vhost_from_headers_ex(r, strict_host_check);
      if (strict_host_check && access_status != HTTP_OK) { 
          if (r->server == ap_server_conf) { 
              ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(10156)
                            "Requested hostname '%s' did not match any ServerName/ServerAlias "
                            "in the global server configuration ", r->hostname);
          }
          else { 
              ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(10157)
                            "Requested hostname '%s' did not match any ServerName/ServerAlias "
                            "in the matching virtual host (default vhost for "
                            "current connection is %s:%u)", 
                            r->hostname, r->server->defn_name, r->server->defn_line_number);
          }
          r->status = access_status;
      }
      if (r->status != HTTP_OK) { 
          return 0;
      }
  
      if ((!r->hostname && (r->proto_num >= HTTP_VERSION(1, 1)))
          || ((r->proto_num == HTTP_VERSION(1, 1))
              && !apr_table_get(r->headers_in, "Host"))) {
          /*
           * Client sent us an HTTP/1.1 or later request without telling us the
           * hostname, either with a full URL or a Host: header. We therefore
           * need to (as per the 1.1 spec) send an error.  As a special case,
           * HTTP/1.1 mentions twice (S9, S14.23) that a request MUST contain
           * a Host: header, and the server MUST respond with 400 if it doesn't.
           */
          ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00569)
                        "client sent HTTP/1.1 request without hostname "
                        "(see RFC2616 section 14.23): %s", r->uri);
          r->status = HTTP_BAD_REQUEST;
          return 0;
      }
  
      /* we may have switched to another server */
      conf = ap_get_core_module_config(r->server->module_config);
  
      if (((expect = apr_table_get(r->headers_in, "Expect")) != NULL)
          && (expect[0] != '\0')) {
          /*
           * The Expect header field was added to HTTP/1.1 after RFC 2068
           * as a means to signal when a 100 response is desired and,
           * unfortunately, to signal a poor man's mandatory extension that
           * the server must understand or return 417 Expectation Failed.
           */
          if (ap_cstr_casecmp(expect, "100-continue") == 0) {
              r->expecting_100 = 1;
          }
          else if (conf->http_expect_strict == AP_HTTP_EXPECT_STRICT_DISABLE) {
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02595)
                            "client sent an unrecognized expectation value "
                            "of Expect (not fatal): %s", expect);
          }
          else {
              ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(00570)
                            "client sent an unrecognized expectation value "
                            "of Expect: %s", expect);
              r->status = HTTP_EXPECTATION_FAILED;
              return 0;
          }
      }
  
      return 1;
  }
  
  static int table_do_fn_check_lengths(void *r_, const char *key,
                                       const char *value)
  {
      request_rec *r = r_;
      if (value == NULL || r->server->limit_req_fieldsize >= strlen(value) )
          return 1;
  
      r->status = HTTP_BAD_REQUEST;
      apr_table_setn(r->notes, "error-notes",
                     "Size of a request header field exceeds server limit.");
      ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(00560) "Request "
                    "header exceeds LimitRequestFieldSize after merging: %.*s",
                    field_name_len(key), key);
      return 0;
  }
  
  AP_DECLARE(void) ap_get_mime_headers_core(request_rec *r, apr_bucket_brigade *bb)
  {
      char *last_field = NULL;
      apr_size_t last_len = 0;
      apr_size_t alloc_len = 0;
      char *field;
      char *value;
      apr_size_t len;
      int fields_read = 0;
      char *tmp_field;
      core_server_config *conf = ap_get_core_module_config(r->server->module_config);
      int strict = (conf->http_conformance != AP_HTTP_CONFORMANCE_UNSAFE);
  
      /*
       * Read header lines until we get the empty separator line, a read error,
       * the connection closes (EOF), reach the server limit, or we timeout.
       */
      while(1) {
          apr_status_t rv;
  
          field = NULL;
          rv = ap_rgetline(&field, r->server->limit_req_fieldsize + 2,
                           &len, r, strict ? AP_GETLINE_CRLF : 0, bb);
  
          if (rv != APR_SUCCESS) {
              if (APR_STATUS_IS_TIMEUP(rv)) {
                  r->status = HTTP_REQUEST_TIME_OUT;
              }
              else {
                  r->status = HTTP_BAD_REQUEST;
              }
  
              /* ap_rgetline returns APR_ENOSPC if it fills up the buffer before
               * finding the end-of-line.  This is only going to happen if it
               * exceeds the configured limit for a field size.
               */
              if (rv == APR_ENOSPC) {
                  apr_table_setn(r->notes, "error-notes",
                                 "Size of a request header field "
                                 "exceeds server limit.");
                  ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(00561)
                                "Request header exceeds LimitRequestFieldSize%s"
                                "%.*s",
                                (field && *field) ? ": " : "",
                                (field) ? field_name_len(field) : 0,
                                (field) ? field : "");
              }
              return;
          }
  
          /* For all header values, and all obs-fold lines, the presence of
           * additional whitespace is a no-op, so collapse trailing whitespace
           * to save buffer allocation and optimize copy operations.
           * Do not remove the last single whitespace under any condition.
           */
          while (len > 1 && (field[len-1] == '\t' || field[len-1] == ' ')) {
              field[--len] = '\0';
          } 
  
          if (*field == '\t' || *field == ' ') {
  
              /* Append any newly-read obs-fold line onto the preceding
               * last_field line we are processing
               */
              apr_size_t fold_len;
  
              if (last_field == NULL) {
                  r->status = HTTP_BAD_REQUEST;
                  ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03442)
                                "Line folding encountered before first"
                                " header line");
                  return;
              }
  
              if (field[1] == '\0') {
                  r->status = HTTP_BAD_REQUEST;
                  ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03443)
                                "Empty folded line encountered");
                  return;
              }
  
              /* Leading whitespace on an obs-fold line can be
               * similarly discarded */
              while (field[1] == '\t' || field[1] == ' ') {
                  ++field; --len;
              }
  
              /* This line is a continuation of the preceding line(s),
               * so append it to the line that we've set aside.
               * Note: this uses a power-of-two allocator to avoid
               * doing O(n) allocs and using O(n^2) space for
               * continuations that span many many lines.
               */
              fold_len = last_len + len + 1; /* trailing null */
  
              if (fold_len >= (apr_size_t)(r->server->limit_req_fieldsize)) {
                  r->status = HTTP_BAD_REQUEST;
                  /* report what we have accumulated so far before the
                   * overflow (last_field) as the field with the problem
                   */
                  apr_table_setn(r->notes, "error-notes",
                                 "Size of a request header field "
                                 "exceeds server limit.");
                  ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(00562)
                                "Request header exceeds LimitRequestFieldSize "
                                "after folding: %.*s",
                                field_name_len(last_field), last_field);
                  return;
              }
  
              if (fold_len > alloc_len) {
                  char *fold_buf;
                  alloc_len += alloc_len;
                  if (fold_len > alloc_len) {
                      alloc_len = fold_len;
                  }
                  fold_buf = (char *)apr_palloc(r->pool, alloc_len);
                  memcpy(fold_buf, last_field, last_len);
                  last_field = fold_buf;
              }
              memcpy(last_field + last_len, field, len +1); /* +1 for nul */
              /* Replace obs-fold w/ SP per RFC 7230 3.2.4 */
              last_field[last_len] = ' ';
              last_len += len;
  
              /* We've appended this obs-fold line to last_len, proceed to
               * read the next input line
               */
              continue;
          }
          else if (last_field != NULL) {
  
              /* Process the previous last_field header line with all obs-folded
               * segments already concatenated (this is not operating on the
               * most recently read input line).
               */
  
              if (r->server->limit_req_fields
                      && (++fields_read > r->server->limit_req_fields)) {
                  r->status = HTTP_BAD_REQUEST;
                  apr_table_setn(r->notes, "error-notes",
                                 "The number of request header fields "
                                 "exceeds this server's limit.");
                  ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(00563)
                                "Number of request headers exceeds "
                                "LimitRequestFields");
                  return;
              }
  
              if (!strict)
              {
                  /* Not Strict ('Unsafe' mode), using the legacy parser */
  
                  if (!(value = strchr(last_field, ':'))) { /* Find ':' or */
                      r->status = HTTP_BAD_REQUEST;   /* abort bad request */
                      ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00564)
                                    "Request header field is missing ':' "
                                    "separator: %.*s", (int)LOG_NAME_MAX_LEN,
                                    last_field);
                      return;
                  }
  
                  if (value == last_field) {
                      r->status = HTTP_BAD_REQUEST;
                      ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03453)
                                    "Request header field name was empty");
                      return;
                  }
  
                  *value++ = '\0'; /* NUL-terminate at colon */
  
                  if (strpbrk(last_field, "\t\n\v\f\r ")) {
                      r->status = HTTP_BAD_REQUEST;
                      ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03452)
                                    "Request header field name presented"
                                    " invalid whitespace");
                      return;
                  }
  
                  while (*value == ' ' || *value == '\t') {
                       ++value;            /* Skip to start of value   */
                  }
  
                  if (strpbrk(value, "\n\v\f\r")) {
                      r->status = HTTP_BAD_REQUEST;
                      ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03451)
                                    "Request header field value presented"
                                    " bad whitespace");
                      return;
                  }
              }
              else /* Using strict RFC7230 parsing */
              {
                  /* Ensure valid token chars before ':' per RFC 7230 3.2.4 */
                  value = (char *)ap_scan_http_token(last_field);
                  if ((value == last_field) || *value != ':') {
                      r->status = HTTP_BAD_REQUEST;
                      ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02426)
                                    "Request header field name is malformed: "
                                    "%.*s", (int)LOG_NAME_MAX_LEN, last_field);
                      return;
                  }
  
                  *value++ = '\0'; /* NUL-terminate last_field name at ':' */
  
                  while (*value == ' ' || *value == '\t') {
                      ++value;     /* Skip LWS of value */
                  }
  
                  /* Find invalid, non-HT ctrl char, or the trailing NULL */
                  tmp_field = (char *)ap_scan_http_field_content(value);
  
                  /* Reject value for all garbage input (CTRLs excluding HT)
                   * e.g. only VCHAR / SP / HT / obs-text are allowed per
                   * RFC7230 3.2.6 - leave all more explicit rule enforcement
                   * for specific header handler logic later in the cycle
                   */
                  if (*tmp_field != '\0') {
                      r->status = HTTP_BAD_REQUEST;
                      ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02427)
                                    "Request header value is malformed: "
                                    "%.*s", (int)LOG_NAME_MAX_LEN, value);
                      return;
                  }
              }
  
              apr_table_addn(r->headers_in, last_field, value);
  
              /* This last_field header is now stored in headers_in,
               * resume processing of the current input line.
               */
          }
  
          /* Found the terminating empty end-of-headers line, stop. */
          if (len == 0) {
              break;
          }
  
          /* Keep track of this new header line so that we can extend it across
           * any obs-fold or parse it on the next loop iteration. We referenced
           * our previously allocated buffer in r->headers_in,
           * so allocate a fresh buffer if required.
           */
          alloc_len = 0;
          last_field = field;
          last_len = len;
      }
  
      /* Combine multiple message-header fields with the same
       * field-name, following RFC 2616, 4.2.
       */
      apr_table_compress(r->headers_in, APR_OVERLAP_TABLES_MERGE);
  
      /* enforce LimitRequestFieldSize for merged headers */
      apr_table_do(table_do_fn_check_lengths, r, r->headers_in, NULL);
  }
  
  AP_DECLARE(void) ap_get_mime_headers(request_rec *r)
  {
      apr_bucket_brigade *tmp_bb;
      tmp_bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
      ap_get_mime_headers_core(r, tmp_bb);
      apr_brigade_destroy(tmp_bb);
  }
  
  AP_DECLARE(request_rec *) ap_create_request(conn_rec *conn)
  {
      request_rec *r;
      apr_pool_t *p;
  
      apr_pool_create(&p, conn->pool);
      apr_pool_tag(p, "request");
      r = apr_pcalloc(p, sizeof(request_rec));
      AP_READ_REQUEST_ENTRY((intptr_t)r, (uintptr_t)conn);
      r->pool            = p;
      r->connection      = conn;
      r->server          = conn->base_server;
  
      r->user            = NULL;
      r->ap_auth_type    = NULL;
  
      r->allowed_methods = ap_make_method_list(p, 2);
  
      r->headers_in      = apr_table_make(r->pool, 25);
      r->trailers_in     = apr_table_make(r->pool, 5);
      r->subprocess_env  = apr_table_make(r->pool, 25);
      r->headers_out     = apr_table_make(r->pool, 12);
      r->err_headers_out = apr_table_make(r->pool, 5);
      r->trailers_out    = apr_table_make(r->pool, 5);
      r->notes           = apr_table_make(r->pool, 5);
  
      r->request_config  = ap_create_request_config(r->pool);
      /* Must be set before we run create request hook */
  
      r->proto_output_filters = conn->output_filters;
      r->output_filters  = r->proto_output_filters;
      r->proto_input_filters = conn->input_filters;
      r->input_filters   = r->proto_input_filters;
      ap_run_create_request(r);
      r->per_dir_config  = r->server->lookup_defaults;
  
      r->sent_bodyct     = 0;                      /* bytect isn't for body */
  
      r->read_length     = 0;
      r->read_body       = REQUEST_NO_BODY;
  
      r->status          = HTTP_OK;  /* Until further notice */
      r->header_only     = 0;
      r->the_request     = NULL;
  
      /* Begin by presuming any module can make its own path_info assumptions,
       * until some module interjects and changes the value.
       */
      r->used_path_info = AP_REQ_DEFAULT_PATH_INFO;
  
      r->useragent_addr = conn->client_addr;
      r->useragent_ip = conn->client_ip;
  
      return r;
  }
  
  /* Apply the server's timeout/config to the connection/request. */
  static void apply_server_config(request_rec *r)
  {
      apr_socket_t *csd;
  
      csd = ap_get_conn_socket(r->connection);
      apr_socket_timeout_set(csd, r->server->timeout);
  
      r->per_dir_config = r->server->lookup_defaults;
  }
  
  request_rec *ap_read_request(conn_rec *conn)
  {
      int access_status;
      apr_bucket_brigade *tmp_bb;
  
      request_rec *r = ap_create_request(conn);
  
      tmp_bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
  
      ap_run_pre_read_request(r, conn);
  
      /* Get the request... */
      if (!read_request_line(r, tmp_bb) || !ap_parse_request_line(r)) {
          apr_brigade_cleanup(tmp_bb);
          switch (r->status) {
          case HTTP_REQUEST_URI_TOO_LARGE:
          case HTTP_BAD_REQUEST:
          case HTTP_VERSION_NOT_SUPPORTED:
          case HTTP_NOT_IMPLEMENTED:
              if (r->status == HTTP_REQUEST_URI_TOO_LARGE) {
                  ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(00565)
                                "request failed: client's request-line exceeds LimitRequestLine (longer than %d)",
                                r->server->limit_req_line);
              }
              else if (r->method == NULL) {
                  ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00566)
                                "request failed: malformed request line");
              }
              access_status = r->status;
              goto die_unusable_input;
  
          case HTTP_REQUEST_TIME_OUT:
              /* Just log, no further action on this connection. */
              ap_update_child_status(conn->sbh, SERVER_BUSY_LOG, NULL);
              if (!r->connection->keepalives)
                  ap_run_log_transaction(r);
              break;
          }
          /* Not worth dying with. */
          conn->keepalive = AP_CONN_CLOSE;
          apr_pool_destroy(r->pool);
          goto ignore;
      }
      apr_brigade_cleanup(tmp_bb);
  
      /* We may have been in keep_alive_timeout mode, so toggle back
       * to the normal timeout mode as we fetch the header lines,
       * as necessary.
       */
      apply_server_config(r);
  
      if (!r->assbackwards) {
          const char *tenc, *clen;
  
          ap_get_mime_headers_core(r, tmp_bb);
          apr_brigade_cleanup(tmp_bb);
          if (r->status != HTTP_OK) {
              ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00567)
                            "request failed: error reading the headers");
              access_status = r->status;
              goto die_unusable_input;
          }
  
          clen = apr_table_get(r->headers_in, "Content-Length");
          if (clen) {
              apr_off_t cl;
  
              if (!ap_parse_strict_length(&cl, clen)) {
                  ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(10242)
                                "client sent invalid Content-Length "
                                "(%s): %s", clen, r->uri);
                  access_status = HTTP_BAD_REQUEST;
                  goto die_unusable_input;
              }
          }
  
          tenc = apr_table_get(r->headers_in, "Transfer-Encoding");
          if (tenc) {
              /* https://tools.ietf.org/html/rfc7230
               * Section 3.3.3.3: "If a Transfer-Encoding header field is
               * present in a request and the chunked transfer coding is not
               * the final encoding ...; the server MUST respond with the 400
               * (Bad Request) status code and then close the connection".
               */
              if (!ap_is_chunked(r->pool, tenc)) {
                  ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02539)
                                "client sent unknown Transfer-Encoding "
                                "(%s): %s", tenc, r->uri);
                  access_status = HTTP_BAD_REQUEST;
                  goto die_unusable_input;
              }
  
              /* https://tools.ietf.org/html/rfc7230
               * Section 3.3.3.3: "If a message is received with both a
               * Transfer-Encoding and a Content-Length header field, the
               * Transfer-Encoding overrides the Content-Length. ... A sender
               * MUST remove the received Content-Length field".
               */
              if (clen) {
                  apr_table_unset(r->headers_in, "Content-Length");
  
                  /* Don't reuse this connection anyway to avoid confusion with
                   * intermediaries and request/reponse spltting.
                   */
                  conn->keepalive = AP_CONN_CLOSE;
              }
          }
      }
  
      /*
       * Add the HTTP_IN filter here to ensure that ap_discard_request_body
       * called by ap_die and by ap_send_error_response works correctly on
       * status codes that do not cause the connection to be dropped and
       * in situations where the connection should be kept alive.
       */
      ap_add_input_filter_handle(ap_http_input_filter_handle,
                                 NULL, r, r->connection);
  
      /* Validate Host/Expect headers and select vhost. */
      if (!ap_check_request_header(r)) {
          /* we may have switched to another server still */
          apply_server_config(r);
          access_status = r->status;
          goto die_before_hooks;
      }
  
      /* we may have switched to another server */
      apply_server_config(r);
  
      if ((access_status = ap_run_post_read_request(r))) {
          goto die;
      }
  
      AP_READ_REQUEST_SUCCESS((uintptr_t)r, (char *)r->method,
                              (char *)r->uri, (char *)r->server->defn_name,
                              r->status);
      return r;
  
      /* Everything falls through on failure */
  
  die_unusable_input:
      /* Input filters are in an undeterminate state, cleanup (including
       * CORE_IN's socket) such that any further attempt to read is EOF.
       */
      {
          ap_filter_t *f = conn->input_filters;
          while (f) {
              ap_filter_reinstate_brigade(f, tmp_bb, NULL);
              apr_brigade_cleanup(tmp_bb);
              if (f->frec == ap_core_input_filter_handle) {
                  break;
              }
              ap_remove_input_filter(f);
              f = f->next;
          }
          conn->input_filters = r->input_filters = f;
          conn->keepalive = AP_CONN_CLOSE;
      }
  
  die_before_hooks:
      /* First call to ap_die() (non recursive) */
      r->status = HTTP_OK;
  
  die:
      ap_die(access_status, r);
  
      /* ap_die() sent the response through the output filters, we must now
       * end the request with an EOR bucket for stream/pipeline accounting.
       */
      {
          apr_bucket_brigade *eor_bb;
          eor_bb = ap_acquire_brigade(conn);
          APR_BRIGADE_INSERT_TAIL(eor_bb,
                                  ap_bucket_eor_create(conn->bucket_alloc, r));
          ap_pass_brigade(conn->output_filters, eor_bb);
          ap_release_brigade(conn, eor_bb);
      }
  
  ignore:
      r = NULL;
      AP_READ_REQUEST_FAILURE((uintptr_t)r);
      return NULL;
  }
  
  /* if a request with a body creates a subrequest, remove original request's
   * input headers which pertain to the body which has already been read.
   * out-of-line helper function for ap_set_sub_req_protocol.
   */
  
  static void strip_headers_request_body(request_rec *rnew)
  {
      apr_table_unset(rnew->headers_in, "Content-Encoding");
      apr_table_unset(rnew->headers_in, "Content-Language");
      apr_table_unset(rnew->headers_in, "Content-Length");
      apr_table_unset(rnew->headers_in, "Content-Location");
      apr_table_unset(rnew->headers_in, "Content-MD5");
      apr_table_unset(rnew->headers_in, "Content-Range");
      apr_table_unset(rnew->headers_in, "Content-Type");
      apr_table_unset(rnew->headers_in, "Expires");
      apr_table_unset(rnew->headers_in, "Last-Modified");
      apr_table_unset(rnew->headers_in, "Transfer-Encoding");
  }
  
  /*
   * A couple of other functions which initialize some of the fields of
   * a request structure, as appropriate for adjuncts of one kind or another
   * to a request in progress.  Best here, rather than elsewhere, since
   * *someone* has to set the protocol-specific fields...
   */
  
  AP_DECLARE(void) ap_set_sub_req_protocol(request_rec *rnew,
                                           const request_rec *r)
  {
      rnew->the_request     = r->the_request;  /* Keep original request-line */
  
      rnew->assbackwards    = 1;   /* Don't send headers from this. */
      rnew->no_local_copy   = 1;   /* Don't try to send HTTP_NOT_MODIFIED for a
                                    * fragment. */
      rnew->method          = "GET";
      rnew->method_number   = M_GET;
      rnew->protocol        = "INCLUDED";
  
      rnew->status          = HTTP_OK;
  
      rnew->headers_in      = apr_table_copy(rnew->pool, r->headers_in);
      rnew->trailers_in     = apr_table_copy(rnew->pool, r->trailers_in);
  
      /* did the original request have a body?  (e.g. POST w/SSI tags)
       * if so, make sure the subrequest doesn't inherit body headers
       */
      if (!r->kept_body && (apr_table_get(r->headers_in, "Content-Length")
          || apr_table_get(r->headers_in, "Transfer-Encoding"))) {
          strip_headers_request_body(rnew);
      }
      rnew->subprocess_env  = apr_table_copy(rnew->pool, r->subprocess_env);
      rnew->headers_out     = apr_table_make(rnew->pool, 5);
      rnew->err_headers_out = apr_table_make(rnew->pool, 5);
      rnew->trailers_out    = apr_table_make(rnew->pool, 5);
      rnew->notes           = apr_table_make(rnew->pool, 5);
  
      rnew->expecting_100   = r->expecting_100;
      rnew->read_length     = r->read_length;
      rnew->read_body       = REQUEST_NO_BODY;
  
      rnew->main = (request_rec *) r;
  }
  
  static void error_output_stream(request_rec *r, int status)
  {
      conn_rec *c = r->connection;
      apr_bucket_brigade *bb;
      apr_bucket *b;
  
      bb = apr_brigade_create(r->pool, c->bucket_alloc);
      b = ap_bucket_error_create(status, NULL, r->pool,
              r->connection->bucket_alloc);
      APR_BRIGADE_INSERT_TAIL(bb, b);
      b = apr_bucket_eos_create(c->bucket_alloc);
      APR_BRIGADE_INSERT_TAIL(bb, b);
      ap_pass_brigade(r->output_filters, bb);
  }
  
  static void end_output_stream(request_rec *r)
  {
      conn_rec *c = r->connection;
      apr_bucket_brigade *bb;
      apr_bucket *b;
  
      bb = apr_brigade_create(r->pool, c->bucket_alloc);
      b = apr_bucket_eos_create(c->bucket_alloc);
      APR_BRIGADE_INSERT_TAIL(bb, b);
      ap_pass_brigade(r->output_filters, bb);
  }
  
  AP_DECLARE(void) ap_finalize_sub_req_protocol(request_rec *sub)
  {
      /* tell the filter chain there is no more content coming */
      if (!sub->eos_sent) {
          end_output_stream(sub);
      }
  }
  
  /* finalize_request_protocol is called at completion of sending the
   * response.  Its sole purpose is to send the terminating protocol
   * information for any wrappers around the response message body
   * (i.e., transfer encodings).  It should have been named finalize_response.
   */
  AP_DECLARE(void) ap_finalize_request_protocol(request_rec *r)
  {
      int status = ap_discard_request_body(r);
  
      /* tell the filter chain there is no more content coming */
      if (status) {
          error_output_stream(r, status);
      }
      if (!r->eos_sent) {
          end_output_stream(r);
      }
  }
  
  /*
   * Support for the Basic authentication protocol, and a bit for Digest.
   */
  AP_DECLARE(void) ap_note_auth_failure(request_rec *r)
  {
      const char *type = ap_auth_type(r);
      if (type) {
          ap_run_note_auth_failure(r, type);
      }
      else {
          ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00571)
                        "need AuthType to note auth failure: %s", r->uri);
      }
  }
  
  AP_DECLARE(void) ap_note_basic_auth_failure(request_rec *r)
  {
      ap_note_auth_failure(r);
  }
  
  AP_DECLARE(void) ap_note_digest_auth_failure(request_rec *r)
  {
      ap_note_auth_failure(r);
  }
  
  AP_DECLARE(int) ap_get_basic_auth_pw(request_rec *r, const char **pw)
  {
      const char *t, *auth_line;
  
      if (!(t = ap_auth_type(r)) || ap_cstr_casecmp(t, "Basic"))
          return DECLINED;
  
      if (!ap_auth_name(r)) {
          ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00572) 
                        "need AuthName: %s", r->uri);
          return HTTP_INTERNAL_SERVER_ERROR;
      }
  
      auth_line = apr_table_get(r->headers_in,
                                (PROXYREQ_PROXY == r->proxyreq)
                                    ? "Proxy-Authorization" : "Authorization");
  
      if (!auth_line) {
          ap_note_auth_failure(r);
          return HTTP_UNAUTHORIZED;
      }
  
      if (ap_cstr_casecmp(ap_getword(r->pool, &auth_line, ' '), "Basic")) {
          /* Client tried to authenticate using wrong auth scheme */
          ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(00573)
                        "client used wrong authentication scheme: %s", r->uri);
          ap_note_auth_failure(r);
          return HTTP_UNAUTHORIZED;
      }
  
      while (*auth_line == ' ' || *auth_line == '\t') {
          auth_line++;
      }
  
      t = ap_pbase64decode(r->pool, auth_line);
      r->user = ap_getword_nulls (r->pool, &t, ':');
      apr_table_setn(r->notes, AP_GET_BASIC_AUTH_PW_NOTE, "1");
      r->ap_auth_type = "Basic";
  
      *pw = t;
  
      return OK;
  }
  
  AP_DECLARE(apr_status_t) ap_get_basic_auth_components(const request_rec *r,
                                                        const char **username,
                                                        const char **password)
  {
      const char *auth_header;
      const char *credentials;
      const char *decoded;
      const char *user;
  
      auth_header = (PROXYREQ_PROXY == r->proxyreq) ? "Proxy-Authorization"
                                                    : "Authorization";
      credentials = apr_table_get(r->headers_in, auth_header);
  
      if (!credentials) {
          /* No auth header. */
          return APR_EINVAL;
      }
  
      if (ap_cstr_casecmp(ap_getword(r->pool, &credentials, ' '), "Basic")) {
          /* These aren't Basic credentials. */
          return APR_EINVAL;
      }
  
      while (*credentials == ' ' || *credentials == '\t') {
          credentials++;
      }
  
      /* XXX Our base64 decoding functions don't actually error out if the string
       * we give it isn't base64; they'll just silently stop and hand us whatever
       * they've parsed up to that point.
       *
       * Since this function is supposed to be a drop-in replacement for the
       * deprecated ap_get_basic_auth_pw(), don't fix this for 2.4.x.
       */
      decoded = ap_pbase64decode(r->pool, credentials);
      user = ap_getword_nulls(r->pool, &decoded, ':');
  
      if (username) {
          *username = user;
      }
      if (password) {
          *password = decoded;
      }
  
      return APR_SUCCESS;
  }
  
  struct content_length_ctx {
      int data_sent;  /* true if the C-L filter has already sent at
                       * least one bucket on to the next output filter
                       * for this request
                       */
      apr_bucket_brigade *tmpbb;
  };
  
  /* This filter computes the content length, but it also computes the number
   * of bytes sent to the client.  This means that this filter will always run
   * through all of the buckets in all brigades
   */
  AP_CORE_DECLARE_NONSTD(apr_status_t) ap_content_length_filter(
      ap_filter_t *f,
      apr_bucket_brigade *b)
  {
      request_rec *r = f->r;
      struct content_length_ctx *ctx;
      apr_bucket *e;
      int eos = 0;
      apr_read_type_e eblock = APR_NONBLOCK_READ;
  
      ctx = f->ctx;
      if (!ctx) {
          f->ctx = ctx = apr_palloc(r->pool, sizeof(*ctx));
          ctx->data_sent = 0;
          ctx->tmpbb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
      }
  
      /* Loop through the brigade to count the length. To avoid
       * arbitrary memory consumption with morphing bucket types, this
       * loop will stop and pass on the brigade when necessary. */
      e = APR_BRIGADE_FIRST(b);
      while (e != APR_BRIGADE_SENTINEL(b)) {
          apr_status_t rv;
  
          if (APR_BUCKET_IS_EOS(e)) {
              eos = 1;
              break;
          }
          /* For a flush bucket, fall through to pass the brigade and
           * flush now. */
          else if (APR_BUCKET_IS_FLUSH(e)) {
              e = APR_BUCKET_NEXT(e);
          }
          /* For metadata bucket types other than FLUSH, loop. */
          else if (APR_BUCKET_IS_METADATA(e)) {
              e = APR_BUCKET_NEXT(e);
              continue;
          }
          /* For determinate length data buckets, count the length and
           * continue. */
          else if (e->length != (apr_size_t)-1) {
              r->bytes_sent += e->length;
              e = APR_BUCKET_NEXT(e);
              continue;
          }
          /* For indeterminate length data buckets, perform one read. */
          else /* e->length == (apr_size_t)-1 */ {
              apr_size_t len;
              const char *ignored;
          
              rv = apr_bucket_read(e, &ignored, &len, eblock);
              if ((rv != APR_SUCCESS) && !APR_STATUS_IS_EAGAIN(rv)) {
                  ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(00574)
                                "ap_content_length_filter: "
                                "apr_bucket_read() failed");
                  return rv;
              }
              if (rv == APR_SUCCESS) {
                  eblock = APR_NONBLOCK_READ;
                  e = APR_BUCKET_NEXT(e);
                  r->bytes_sent += len;
              }
              else if (APR_STATUS_IS_EAGAIN(rv)) {
                  apr_bucket *flush;
  
                  /* Next read must block. */
                  eblock = APR_BLOCK_READ;
  
                  /* Ensure the last bucket to pass down is a flush if
                   * the next read will block. */
                  flush = apr_bucket_flush_create(f->c->bucket_alloc);
                  APR_BUCKET_INSERT_BEFORE(e, flush);
              }
          }
  
          /* Optimization: if the next bucket is EOS (directly after a
           * bucket morphed to the heap, or a flush), short-cut to
           * handle EOS straight away - allowing C-L to be determined
           * for content which is already entirely in memory. */
          if (e != APR_BRIGADE_SENTINEL(b) && APR_BUCKET_IS_EOS(e)) {
              continue;
          }
  
          /* On reaching here, pass on everything in the brigade up to
           * this point. */
          apr_brigade_split_ex(b, e, ctx->tmpbb);
          
          rv = ap_pass_brigade(f->next, b);
          if (rv != APR_SUCCESS) {
              return rv;
          }
          else if (f->c->aborted) {
              return APR_ECONNABORTED;
          }
          apr_brigade_cleanup(b);
          APR_BRIGADE_CONCAT(b, ctx->tmpbb);
          e = APR_BRIGADE_FIRST(b);
          
          ctx->data_sent = 1;
      }
  
      /* If we've now seen the entire response and it's otherwise
       * okay to set the C-L in the response header, then do so now.
       *
       * We can only set a C-L in the response header if we haven't already
       * sent any buckets on to the next output filter for this request.
       */
      if (ctx->data_sent == 0 && eos) {
          core_server_config *conf =
              ap_get_core_module_config(r->server->module_config);
  
          /* This is a hack, but I can't find anyway around it.  The idea is that
           * we don't want to send out 0 Content-Lengths if it is a HEAD request.
           * [Unless the corresponding body (for a GET) would really be empty!]
           * This happens when modules try to outsmart the server, and return
           * if they see a HEAD request.  Apache 1.3 handlers were supposed to
           * just return in that situation, and the core handled the HEAD.  From
           * 2.0, if a handler returns, then the core sends an EOS bucket down
           * the filter stack, and this content-length filter computes a length
           * of zero and we would end up sending a zero C-L to the client.
           * We can't just remove the this 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.
           */
  
          /* don't whack the C-L if it has already been set for a HEAD
           * by something like proxy.  the brigade only has an EOS bucket
           * in this case, making r->bytes_sent zero, and either there is
           * an existing C-L we want to preserve, or r->sent_bodyct is not
           * zero (the empty body is being sent) thus we don't want to add
           * a C-L of zero (the backend did not provide it, neither do we).
           *
           * if r->bytes_sent > 0 we have a (temporary) body whose length may
           * have been changed by a filter.  the C-L header might not have been
           * updated so we do it here.  long term it would be cleaner to have
           * such filters update or remove the C-L header, and just use it
           * if present.
           */
          if (!((r->header_only || AP_STATUS_IS_HEADER_ONLY(r->status))
                && !r->bytes_sent
                && (r->sent_bodyct
                    || conf->http_cl_head_zero != AP_HTTP_CL_HEAD_ZERO_ENABLE
                    || apr_table_get(r->headers_out, "Content-Length")))) {
              ap_set_content_length(r, r->bytes_sent);
          }
      }
  
      ctx->data_sent = 1;
      return ap_pass_brigade(f->next, b);
  }
  
  /*
   * Send the body of a response to the client.
   */
  AP_DECLARE(apr_status_t) ap_send_fd(apr_file_t *fd, request_rec *r,
                                      apr_off_t offset, apr_size_t len,
                                      apr_size_t *nbytes)
  {
      conn_rec *c = r->connection;
      apr_bucket_brigade *bb = NULL;
      apr_status_t rv;
  
      bb = apr_brigade_create(r->pool, c->bucket_alloc);
  
      apr_brigade_insert_file(bb, fd, offset, len, r->pool);
  
      rv = ap_pass_brigade(r->output_filters, bb);
      if (rv != APR_SUCCESS) {
          *nbytes = 0; /* no way to tell how many were actually sent */
      }
      else {
          *nbytes = len;
      }
  
      return rv;
  }
  
  #if APR_HAS_MMAP
  /* send data from an in-memory buffer */
  AP_DECLARE(apr_size_t) ap_send_mmap(apr_mmap_t *mm,
                                      request_rec *r,
                                      apr_size_t offset,
                                      apr_size_t length)
  {
      conn_rec *c = r->connection;
      apr_bucket_brigade *bb = NULL;
      apr_bucket *b;
  
      bb = apr_brigade_create(r->pool, c->bucket_alloc);
      b = apr_bucket_mmap_create(mm, offset, length, c->bucket_alloc);
      APR_BRIGADE_INSERT_TAIL(bb, b);
      ap_pass_brigade(r->output_filters, bb);
  
      return mm->size; /* XXX - change API to report apr_status_t? */
  }
  #endif /* APR_HAS_MMAP */
  
  typedef struct {
      apr_bucket_brigade *bb;
      apr_bucket_brigade *tmpbb;
  } old_write_filter_ctx;
  
  AP_CORE_DECLARE_NONSTD(apr_status_t) ap_old_write_filter(
      ap_filter_t *f, apr_bucket_brigade *bb)
  {
      old_write_filter_ctx *ctx = f->ctx;
  
      AP_DEBUG_ASSERT(ctx);
  
      if (ctx->bb != NULL) {
          /* whatever is coming down the pipe (we don't care), we
           * can simply insert our buffered data at the front and
           * pass the whole bundle down the chain.
           */
          APR_BRIGADE_PREPEND(bb, ctx->bb);
      }
  
      return ap_pass_brigade(f->next, bb);
  }
  
  static ap_filter_t *insert_old_write_filter(request_rec *r)
  {
      ap_filter_t *f;
      old_write_filter_ctx *ctx;
  
      /* future optimization: record some flags in the request_rec to
       * say whether we've added our filter, and whether it is first.
       */
  
      /* this will typically exit on the first test */
      for (f = r->output_filters; f != NULL; f = f->next) {
          if (ap_old_write_func == f->frec)
              break;
      }
  
      if (f == NULL) {
          /* our filter hasn't been added yet */
          ctx = apr_pcalloc(r->pool, sizeof(*ctx));
          ctx->tmpbb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
  
          ap_add_output_filter("OLD_WRITE", ctx, r, r->connection);
          f = r->output_filters;
      }
  
      return f;
  }
  
  static apr_status_t buffer_output(request_rec *r,
                                    const char *str, apr_size_t len)
  {
      conn_rec *c = r->connection;
      ap_filter_t *f;
      old_write_filter_ctx *ctx;
  
      if (len == 0)
          return APR_SUCCESS;
  
      f = insert_old_write_filter(r);
      ctx = f->ctx;
  
      /* if the first filter is not our buffering filter, then we have to
       * deliver the content through the normal filter chain
       */
      if (f != r->output_filters) {
          apr_status_t rv;
          apr_bucket *b = apr_bucket_transient_create(str, len, c->bucket_alloc);
          APR_BRIGADE_INSERT_TAIL(ctx->tmpbb, b);
  
          rv = ap_pass_brigade(r->output_filters, ctx->tmpbb);
          apr_brigade_cleanup(ctx->tmpbb);
          return rv;
      }
  
      if (ctx->bb == NULL) {
          ctx->bb = apr_brigade_create(r->pool, c->bucket_alloc);
      }
  
      return ap_fwrite(f->next, ctx->bb, str, len);
  }
  
  AP_DECLARE(int) ap_rputc(int c, request_rec *r)
  {
      char c2 = (char)c;
  
      if (r->connection->aborted) {
          return -1;
      }
  
      if (buffer_output(r, &c2, 1) != APR_SUCCESS)
          return -1;
  
      return c;
  }
  
  AP_DECLARE(int) ap_rwrite(const void *buf, int nbyte, request_rec *r)
  {
      if (r->connection->aborted)
          return -1;
  
      if (buffer_output(r, buf, nbyte) != APR_SUCCESS)
          return -1;
  
      return nbyte;
  }
  
  struct ap_vrprintf_data {
      apr_vformatter_buff_t vbuff;
      request_rec *r;
      char *buff;
  };
  
  /* Flush callback for apr_vformatter; returns -1 on error. */
  static int r_flush(apr_vformatter_buff_t *buff)
  {
      /* callback function passed to ap_vformatter to be called when
       * vformatter needs to write into buff and buff.curpos > buff.endpos */
  
      /* ap_vrprintf_data passed as a apr_vformatter_buff_t, which is then
       * "downcast" to an ap_vrprintf_data */
      struct ap_vrprintf_data *vd = (struct ap_vrprintf_data*)buff;
  
      if (vd->r->connection->aborted)
          return -1;
  
      /* r_flush is called when vbuff is completely full */
      if (buffer_output(vd->r, vd->buff, AP_IOBUFSIZE)) {
          return -1;
      }
  
      /* reset the buffer position */
      vd->vbuff.curpos = vd->buff;
      vd->vbuff.endpos = vd->buff + AP_IOBUFSIZE;
  
      return 0;
  }
  
  AP_DECLARE(int) ap_vrprintf(request_rec *r, const char *fmt, va_list va)
  {
      int written;
      struct ap_vrprintf_data vd;
      char vrprintf_buf[AP_IOBUFSIZE];
  
      vd.vbuff.curpos = vrprintf_buf;
      vd.vbuff.endpos = vrprintf_buf + AP_IOBUFSIZE;
      vd.r = r;
      vd.buff = vrprintf_buf;
  
      if (r->connection->aborted)
          return -1;
  
      written = apr_vformatter(r_flush, &vd.vbuff, fmt, va);
  
      if (written != -1) {
          int n = vd.vbuff.curpos - vrprintf_buf;
  
          /* last call to buffer_output, to finish clearing the buffer */
          if (buffer_output(r, vrprintf_buf, n) != APR_SUCCESS)
              return -1;
  
          written += n;
      }
  
      return written;
  }
  
  AP_DECLARE_NONSTD(int) ap_rprintf(request_rec *r, const char *fmt, ...)
  {
      va_list va;
      int n;
  
      if (r->connection->aborted)
          return -1;
  
      va_start(va, fmt);
      n = ap_vrprintf(r, fmt, va);
      va_end(va);
  
      return n;
  }
  
  AP_DECLARE_NONSTD(int) ap_rvputs(request_rec *r, ...)
  {
      va_list va;
      const char *s;
      apr_size_t len;
      apr_size_t written = 0;
  
      if (r->connection->aborted)
          return -1;
  
      /* ### TODO: if the total output is large, put all the strings
       * ### into a single brigade, rather than flushing each time we
       * ### fill the buffer
       */
      va_start(va, r);
      while (1) {
          s = va_arg(va, const char *);
          if (s == NULL)
              break;
  
          len = strlen(s);
          if (buffer_output(r, s, len) != APR_SUCCESS) {
              va_end(va);
              return -1;
          }
  
          written += len;
      }
      va_end(va);
  
      return written;
  }
  
  AP_DECLARE(int) ap_rflush(request_rec *r)
  {
      conn_rec *c = r->connection;
      apr_bucket *b;
      ap_filter_t *f;
      old_write_filter_ctx *ctx;
      apr_status_t rv;
  
      f = insert_old_write_filter(r);
      ctx = f->ctx;
  
      b = apr_bucket_flush_create(c->bucket_alloc);
      APR_BRIGADE_INSERT_TAIL(ctx->tmpbb, b);
  
      rv = ap_pass_brigade(r->output_filters, ctx->tmpbb);
      apr_brigade_cleanup(ctx->tmpbb);
      if (rv != APR_SUCCESS)
          return -1;
  
      return 0;
  }
  
  /*
   * This function sets the Last-Modified output header field to the value
   * of the mtime field in the request structure - rationalized to keep it from
   * being in the future.
   */
  AP_DECLARE(void) ap_set_last_modified(request_rec *r)
  {
      if (!r->assbackwards) {
          apr_time_t mod_time = ap_rationalize_mtime(r, r->mtime);
          char *datestr = apr_palloc(r->pool, APR_RFC822_DATE_LEN);
  
          apr_rfc822_date(datestr, mod_time);
          apr_table_setn(r->headers_out, "Last-Modified", datestr);
      }
  }
  
  typedef struct hdr_ptr {
      ap_filter_t *f;
      apr_bucket_brigade *bb;
  } hdr_ptr;
  
   
  #if APR_CHARSET_EBCDIC
  static int send_header(void *data, const char *key, const char *val)
  {
      char *header_line = NULL;
      hdr_ptr *hdr = (hdr_ptr*)data;
  
      header_line = apr_pstrcat(hdr->bb->p, key, ": ", val, CRLF, NULL);
      ap_xlate_proto_to_ascii(header_line, strlen(header_line));
      ap_fputs(hdr->f, hdr->bb, header_line);
      return 1;
  }
  #else
  static int send_header(void *data, const char *key, const char *val)
  {
       ap_fputstrs(((hdr_ptr*)data)->f, ((hdr_ptr*)data)->bb,
                   key, ": ", val, CRLF, NULL);
       return 1;
   }
  #endif
  
  AP_DECLARE(void) ap_send_interim_response(request_rec *r, int send_headers)
  {
      hdr_ptr x;
      char *response_line = NULL;
      const char *status_line;
      request_rec *rr;
  
      if (r->proto_num < HTTP_VERSION(1,1)) {
          /* don't send interim response to HTTP/1.0 Client */
          return;
      }
      if (!ap_is_HTTP_INFO(r->status)) {
          ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00575)
                        "Status is %d - not sending interim response", r->status);
          return;
      }
      if (r->status == HTTP_CONTINUE) {
          if (!r->expecting_100) {
              /*
               * Don't send 100-Continue when there was no Expect: 100-continue
               * in the request headers. For origin servers this is a SHOULD NOT
               * for proxies it is a MUST NOT according to RFC 2616 8.2.3
               */
              return;
          }
  
          /* if we send an interim response, we're no longer in a state of
           * expecting one.  Also, this could feasibly be in a subrequest,
           * so we need to propagate the fact that we responded.
           */
          for (rr = r; rr != NULL; rr = rr->main) {
              rr->expecting_100 = 0;
          }
      }
  
      status_line = r->status_line;
      if (status_line == NULL) {
          status_line = ap_get_status_line_ex(r->pool, r->status);
      }
      response_line = apr_pstrcat(r->pool,
                                  AP_SERVER_PROTOCOL " ", status_line, CRLF,
                                  NULL);
      ap_xlate_proto_to_ascii(response_line, strlen(response_line));
  
      x.f = r->connection->output_filters;
      x.bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
  
      ap_fputs(x.f, x.bb, response_line);
      if (send_headers) {
          apr_table_do(send_header, &x, r->headers_out, NULL);
          apr_table_clear(r->headers_out);
      }
      ap_fputs(x.f, x.bb, CRLF_ASCII);
      ap_fflush(x.f, x.bb);
      apr_brigade_destroy(x.bb);
  }
  
  /*
   * Compare two protocol identifier. Result is similar to strcmp():
   * 0 gives same precedence, >0 means proto1 is preferred.
   */
  static int protocol_cmp(const apr_array_header_t *preferences,
                          const char *proto1,
                          const char *proto2)
  {
      if (preferences && preferences->nelts > 0) {
          int index1 = ap_array_str_index(preferences, proto1, 0);
          int index2 = ap_array_str_index(preferences, proto2, 0);
          if (index2 > index1) {
              return (index1 >= 0) ? 1 : -1;
          }
          else if (index1 > index2) {
              return (index2 >= 0) ? -1 : 1;
          }
      }
      /* both have the same index (maybe -1 or no pref configured) and we compare
       * the names so that spdy3 gets precedence over spdy2. That makes
       * the outcome at least deterministic. */
      return strcmp(proto1, proto2);
  }
  
  AP_DECLARE(const char *) ap_get_protocol(conn_rec *c)
  {
      const char *protocol = ap_run_protocol_get(c);
      return protocol? protocol : AP_PROTOCOL_HTTP1;
  }
  
  AP_DECLARE(apr_status_t) ap_get_protocol_upgrades(conn_rec *c, request_rec *r, 
                                                    server_rec *s, int report_all, 
                                                    const apr_array_header_t **pupgrades)
  {
      apr_pool_t *pool = r? r->pool : c->pool;
      core_server_config *conf;
      const char *existing;
      apr_array_header_t *upgrades = NULL;
  
      if (!s) {
          s = (r? r->server : c->base_server);
      }
      conf = ap_get_core_module_config(s->module_config);
      
      if (conf->protocols->nelts > 0) {
          existing = ap_get_protocol(c);
          if (conf->protocols->nelts > 1 
              || !ap_array_str_contains(conf->protocols, existing)) {
              int i;
              
              /* possibly more than one choice or one, but not the
               * existing. (TODO: maybe 426 and Upgrade then?) */
              upgrades = apr_array_make(pool, conf->protocols->nelts + 1, 
                                        sizeof(char *));
              for (i = 0; i < conf->protocols->nelts; i++) {
                  const char *p = APR_ARRAY_IDX(conf->protocols, i, char *);
                  if (strcmp(existing, p)) {
                      /* not the one we have and possible, add in this order */
                      APR_ARRAY_PUSH(upgrades, const char*) = p;
                  }
                  else if (!report_all) {
                      break;
                  }
              }
          }
      }
      
      *pupgrades = upgrades;
      return APR_SUCCESS;
  }
  
  AP_DECLARE(const char *) ap_select_protocol(conn_rec *c, request_rec *r, 
                                              server_rec *s,
                                              const apr_array_header_t *choices)
  {
      apr_pool_t *pool = r? r->pool : c->pool;
      core_server_config *conf;
      const char *protocol = NULL, *existing;
      apr_array_header_t *proposals;
  
      if (!s) {
          s = (r? r->server : c->base_server);
      }
      conf = ap_get_core_module_config(s->module_config);
      
      if (APLOGcdebug(c)) {
          const char *p = apr_array_pstrcat(pool, conf->protocols, ',');
          ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(03155) 
                        "select protocol from %s, choices=%s for server %s", 
                        p, apr_array_pstrcat(pool, choices, ','),
                        s->server_hostname);
      }
  
      if (conf->protocols->nelts <= 0) {
          /* nothing configured, by default, we only allow http/1.1 here.
           * For now...
           */
          if (ap_array_str_contains(choices, AP_PROTOCOL_HTTP1)) {
              return AP_PROTOCOL_HTTP1;
          }
          else {
              return NULL;
          }
      }
  
      proposals = apr_array_make(pool, choices->nelts + 1, sizeof(char *));
      ap_run_protocol_propose(c, r, s, choices, proposals);
  
      /* If the existing protocol has not been proposed, but is a choice,
       * add it to the proposals implicitly.
       */
      existing = ap_get_protocol(c);
      if (!ap_array_str_contains(proposals, existing)
          && ap_array_str_contains(choices, existing)) {
          APR_ARRAY_PUSH(proposals, const char*) = existing;
      }
  
      if (proposals->nelts > 0) {
          int i;
          const apr_array_header_t *prefs = NULL;
  
          /* Default for protocols_honor_order is 'on' or != 0 */
          if (conf->protocols_honor_order == 0 && choices->nelts > 0) {
              prefs = choices;
          }
          else {
              prefs = conf->protocols;
          }
  
          /* Select the most preferred protocol */
          if (APLOGcdebug(c)) {
              ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(03156) 
                            "select protocol, proposals=%s preferences=%s configured=%s", 
                            apr_array_pstrcat(pool, proposals, ','),
                            apr_array_pstrcat(pool, prefs, ','),
                            apr_array_pstrcat(pool, conf->protocols, ','));
          }
          for (i = 0; i < proposals->nelts; ++i) {
              const char *p = APR_ARRAY_IDX(proposals, i, const char *);
              if (!ap_array_str_contains(conf->protocols, p)) {
                  /* not a configured protocol here */
                  continue;
              }
              else if (!protocol 
                       || (protocol_cmp(prefs, protocol, p) < 0)) {
                  /* none selected yet or this one has preference */
                  protocol = p;
              }
          }
      }
      if (APLOGcdebug(c)) {
          ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(03157)
                        "selected protocol=%s", 
                        protocol? protocol : "(none)");
      }
  
      return protocol;
  }
  
  AP_DECLARE(apr_status_t) ap_switch_protocol(conn_rec *c, request_rec *r, 
                                              server_rec *s,
                                              const char *protocol)
  {
      const char *current = ap_get_protocol(c);
      int rc;
      
      if (!strcmp(current, protocol)) {
          ap_log_cerror(APLOG_MARK, APLOG_WARNING, 0, c, APLOGNO(02906)
                        "already at it, protocol_switch to %s", 
                        protocol);
          return APR_SUCCESS;
      }
      
      rc = ap_run_protocol_switch(c, r, s, protocol);
      switch (rc) {
          case DECLINED:
              ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(02907)
                            "no implementation for protocol_switch to %s", 
                            protocol);
              return APR_ENOTIMPL;
          case OK:
          case DONE:
              return APR_SUCCESS;
          default:
              ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(02905)
                            "unexpected return code %d from protocol_switch to %s"
                            , rc, protocol);
              return APR_EOF;
      }    
  }
  
  AP_DECLARE(int) ap_is_allowed_protocol(conn_rec *c, request_rec *r,
                                         server_rec *s, const char *protocol)
  {
      core_server_config *conf;
  
      if (!s) {
          s = (r? r->server : c->base_server);
      }
      conf = ap_get_core_module_config(s->module_config);
      
      if (conf->protocols->nelts > 0) {
          return ap_array_str_contains(conf->protocols, protocol);
      }
      return !strcmp(AP_PROTOCOL_HTTP1, protocol);
  }
  
  APR_DECLARE_OPTIONAL_FN(int, ssl_is_https, (conn_rec *));
  static APR_OPTIONAL_FN_TYPE(ssl_is_https) *module_ssl_is_https;
  
  static int ssl_is_https(conn_rec *c) 
  {
      /* Someone retrieved the optional function., not knowning about the
       * new API. We redirect them to what they should have inoked. */
      return ap_ssl_conn_is_ssl(c);
  }
  
  AP_DECLARE(int) ap_ssl_conn_is_ssl(conn_rec *c)
  {
      int r = (ap_run_ssl_conn_is_ssl(c) == OK);
      if (r == 0 && module_ssl_is_https) {
          r = module_ssl_is_https(c);
      }
      return r;
  }
  
  APR_DECLARE_OPTIONAL_FN(const char *, ssl_var_lookup,
                          (apr_pool_t *p, server_rec *s,
                           conn_rec *c, request_rec *r,
                           const char *name))
      AP_FN_ATTR_NONNULL((1, 2, 5)) AP_FN_ATTR_WARN_UNUSED_RESULT;
  static APR_OPTIONAL_FN_TYPE(ssl_var_lookup) *module_ssl_var_lookup;
      
  static const char *ssl_var_lookup(apr_pool_t *p, server_rec *s,
                                    conn_rec *c, request_rec *r,
                                    const char *name)
  {
      /* Someone retrieved the optional function., not knowning about the
       * new API. We redirect them to what they should have inoked. */
      return ap_ssl_var_lookup(p, s, c, r, name);
  }
  
  AP_DECLARE(const char *) ap_ssl_var_lookup(apr_pool_t *p, server_rec *s,
                                             conn_rec *c, request_rec *r,
                                             const char *name)
  {
      const char *val = ap_run_ssl_var_lookup(p, s, c, r, name);
      if (val == NULL && module_ssl_is_https) {
          val = module_ssl_var_lookup(p, s, c, r, name);
      }
      return val;
  }
  
  AP_DECLARE(void) ap_setup_ssl_optional_fns(apr_pool_t *pool)
  {
      /* Run as core's very early 'post config' hook, check for any already
       * installed optional functions related to SSL and save them. Install
       * our own instances that invoke the new hooks. */
      APR_OPTIONAL_FN_TYPE(ssl_is_https) *fn_is_https;
      APR_OPTIONAL_FN_TYPE(ssl_var_lookup) *fn_ssl_var_lookup;
      
      fn_is_https = APR_RETRIEVE_OPTIONAL_FN(ssl_is_https);
      module_ssl_is_https = (fn_is_https 
          && fn_is_https != ssl_is_https)? fn_is_https : NULL;
      APR_REGISTER_OPTIONAL_FN(ssl_is_https);
  
      fn_ssl_var_lookup = APR_RETRIEVE_OPTIONAL_FN(ssl_var_lookup);
      module_ssl_var_lookup = (fn_ssl_var_lookup 
          && fn_ssl_var_lookup != ssl_var_lookup)? fn_ssl_var_lookup : NULL;
      APR_REGISTER_OPTIONAL_FN(ssl_var_lookup);
  }
  
  AP_DECLARE(apr_status_t) ap_ssl_add_cert_files(server_rec *s, apr_pool_t *p,
                                                 apr_array_header_t *cert_files,
                                                 apr_array_header_t *key_files)
  {
      int rv = ap_run_ssl_add_cert_files(s, p, cert_files, key_files);
      return (rv == OK || rv == DECLINED)? APR_SUCCESS : APR_EGENERAL;
  }         
  
  AP_DECLARE(apr_status_t) ap_ssl_add_fallback_cert_files(server_rec *s, apr_pool_t *p,
                                                          apr_array_header_t *cert_files,
                                                          apr_array_header_t *key_files)
  {
      int rv = ap_run_ssl_add_fallback_cert_files(s, p, cert_files, key_files);
      return (rv == OK || rv == DECLINED)? APR_SUCCESS : APR_EGENERAL;
  }         
  
  AP_DECLARE(int) ap_ssl_answer_challenge(conn_rec *c, const char *server_name, 
                                          const char **pcert_pem, const char **pkey_pem)
  {
      return (ap_run_ssl_answer_challenge(c, server_name, pcert_pem, pkey_pem) == OK);
  }
  
  AP_IMPLEMENT_HOOK_VOID(pre_read_request,
                         (request_rec *r, conn_rec *c),
                         (r, c))
  AP_IMPLEMENT_HOOK_RUN_ALL(int,post_read_request,
                            (request_rec *r), (r), OK, DECLINED)
  AP_IMPLEMENT_HOOK_RUN_ALL(int,log_transaction,
                            (request_rec *r), (r), OK, DECLINED)
  AP_IMPLEMENT_HOOK_RUN_FIRST(const char *,http_scheme,
                              (const request_rec *r), (r), NULL)
  AP_IMPLEMENT_HOOK_RUN_FIRST(unsigned short,default_port,
                              (const request_rec *r), (r), 0)
  AP_IMPLEMENT_HOOK_RUN_FIRST(int, note_auth_failure,
                              (request_rec *r, const char *auth_type),
                              (r, auth_type), DECLINED)
  AP_IMPLEMENT_HOOK_RUN_ALL(int,protocol_propose,
                            (conn_rec *c, request_rec *r, server_rec *s,
                             const apr_array_header_t *offers,
                             apr_array_header_t *proposals), 
                            (c, r, s, offers, proposals), OK, DECLINED)
  AP_IMPLEMENT_HOOK_RUN_FIRST(int,protocol_switch,
                              (conn_rec *c, request_rec *r, server_rec *s,
                               const char *protocol), 
                              (c, r, s, protocol), DECLINED)
  AP_IMPLEMENT_HOOK_RUN_FIRST(const char *,protocol_get,
                              (const conn_rec *c), (c), NULL)
  AP_IMPLEMENT_HOOK_RUN_FIRST(int, ssl_conn_is_ssl, 
                              (conn_rec *c), (c), DECLINED)
  AP_IMPLEMENT_HOOK_RUN_FIRST(const char *,ssl_var_lookup,
          (apr_pool_t *p, server_rec *s, conn_rec *c, request_rec *r, const char *name),
          (p, s, c, r, name), NULL)
  AP_IMPLEMENT_HOOK_RUN_ALL(int, ssl_add_cert_files, 
          (server_rec *s, apr_pool_t *p, 
           apr_array_header_t *cert_files, apr_array_header_t *key_files),
          (s, p, cert_files, key_files), OK, DECLINED)
  AP_IMPLEMENT_HOOK_RUN_ALL(int, ssl_add_fallback_cert_files, 
          (server_rec *s, apr_pool_t *p,
           apr_array_header_t *cert_files, apr_array_header_t *key_files),
          (s, p, cert_files, key_files), OK, DECLINED)
  AP_IMPLEMENT_HOOK_RUN_FIRST(int, ssl_answer_challenge, 
          (conn_rec *c, const char *server_name, const char **pcert_pem, const char **pkey_pem),
          (c, server_name, pcert_pem, pkey_pem), DECLINED)
  
  