/* 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.
 */

#include <string.h>

#include "apr_file_io.h"

#include "httpd.h"
#include "http_config.h"
#include "http_request.h"

/*
 * Test Apache handling of file truncation
 *
 * 1. load this module (full config below)
 * 2. create directory /tmp/mod_trunc
 * 3. issue a request with "truncate" in the query args
 *    example: http://127.0.0.1/index.html?truncate
 *
 * if sendfile is enabled and apr_socket_sendfile() doesn't
 * give retcode feedback, expect a busy loop/swapfest.
 */

/*
Config to use with this:

loadmodule trunc_module modules/mod_trunc.so

<Directory /tmp/mod_trunc>
  AllowOverride None

<IfModule mod_version.c>
  <IfVersion >= 2.3>
  Require all granted
  </IfVersion>

  <IfVersion < 2.3>
  Order Allow,Deny
  Allow from all
  </IfVersion>
</IfModule>

<IfModule !mod_version.c>
  Order Allow,Deny
  Allow from all
</IfModule>

</Directory>

*/

static int trunc_translate_name(request_rec *r)
{
  if (r->args && strstr(r->args, "truncate")) {
    apr_status_t rv;
    apr_file_t *f;

    r->filename = "/tmp/mod_trunc/aaa";

#if APR_MAJOR_VERSION == 0
    rv = apr_file_open(&f, r->filename, 
                       APR_WRITE | APR_CREATE | APR_TRUNCATE,
                       APR_OS_DEFAULT,
                       r->pool);
#else
    rv = apr_file_open(&f, r->filename, 
                       APR_FOPEN_WRITE | APR_FOPEN_CREATE | APR_FOPEN_TRUNCATE,
                       APR_FPROT_OS_DEFAULT,
                       r->pool);
#endif
    if (rv == APR_SUCCESS) {
      const int CHUNK_SIZE = 100000;
      int i;
      char *buf = (char *)malloc(CHUNK_SIZE);
      apr_size_t nbytes;

      memset(buf, '.', CHUNK_SIZE);
      nbytes = CHUNK_SIZE;
      rv = apr_file_write(f, buf, &nbytes);
      apr_file_close(f);
      free(buf);
    }

    return OK;
  }
  return DECLINED;
}

static int trunc_handler(request_rec *r)
{
  apr_status_t rv;
  apr_file_t *f;

  if (r->args && strstr(r->args, "truncate")) {
#if APR_MAJOR_VERSION == 0
    rv = apr_file_open(&f, r->filename, 
                       APR_WRITE | APR_APPEND,
                       APR_OS_DEFAULT,
                       r->pool);
#else
    rv = apr_file_open(&f, r->filename, 
                       APR_FOPEN_WRITE | APR_FOPEN_APPEND,
                       APR_FPROT_OS_DEFAULT,
                       r->pool);
#endif
    if (rv == APR_SUCCESS) {
      apr_file_trunc(f, 50000);
      apr_file_close(f);
    }
  }

  return DECLINED;
}

static void trunc_register_hooks(apr_pool_t *p)
{
  ap_hook_translate_name(trunc_translate_name, NULL, NULL, APR_HOOK_MIDDLE);
  ap_hook_handler(trunc_handler, NULL, NULL, APR_HOOK_FIRST);
}

module AP_MODULE_DECLARE_DATA trunc_module =
{
    STANDARD20_MODULE_STUFF,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    trunc_register_hooks,
};