rubbos/app/httpd-2.0.64/modules/experimental/mod_case_filter.c

   1 /* Licensed to the Apache Software Foundation (ASF) under one or more
   2  * contributor license agreements.  See the NOTICE file distributed with
   3  * this work for additional information regarding copyright ownership.
   4  * The ASF licenses this file to You under the Apache License, Version 2.0
   5  * (the "License"); you may not use this file except in compliance with
   6  * the License.  You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include "httpd.h"
  18 #include "http_config.h"
  19 #include "apr_buckets.h"
  20 #include "apr_general.h"
  21 #include "apr_lib.h"
  22 #include "util_filter.h"
  23 #include "http_request.h"
  24
  25 #include <ctype.h>
  26
  27 static const char s_szCaseFilterName[]="CaseFilter";
  28 module AP_MODULE_DECLARE_DATA case_filter_module;
  29
  30 typedef struct
  31     {
  32     int bEnabled;
  33     } CaseFilterConfig;
  34
  35 static void *CaseFilterCreateServerConfig(apr_pool_t *p,server_rec *s)
  36     {
  37     CaseFilterConfig *pConfig=apr_pcalloc(p,sizeof *pConfig);
  38
  39     pConfig->bEnabled=0;
  40
  41     return pConfig;
  42     }
  43
  44 static void CaseFilterInsertFilter(request_rec *r)
  45     {
  46     CaseFilterConfig *pConfig=ap_get_module_config(r->server->module_config,
  47                                                    &case_filter_module);
  48
  49     if(!pConfig->bEnabled)
  50         return;
  51
  52     ap_add_output_filter(s_szCaseFilterName,NULL,r,r->connection);
  53     }
  54
  55 static apr_status_t CaseFilterOutFilter(ap_filter_t *f,
  56                                         apr_bucket_brigade *pbbIn)
  57     {
  58     request_rec *r = f->r;
  59     conn_rec *c = r->connection;
  60     apr_bucket *pbktIn;
  61     apr_bucket_brigade *pbbOut;
  62
  63     pbbOut=apr_brigade_create(r->pool, c->bucket_alloc);
  64     APR_BRIGADE_FOREACH(pbktIn,pbbIn)
  65         {
  66         const char *data;
  67         apr_size_t len;
  68         char *buf;
  69         apr_size_t n;
  70         apr_bucket *pbktOut;
  71
  72         if(APR_BUCKET_IS_EOS(pbktIn))
  73             {
  74             apr_bucket *pbktEOS=apr_bucket_eos_create(c->bucket_alloc);
  75             APR_BRIGADE_INSERT_TAIL(pbbOut,pbktEOS);
  76             continue;
  77             }
  78
  79         /* read */
  80         apr_bucket_read(pbktIn,&data,&len,APR_BLOCK_READ);
  81
  82         /* write */
  83         buf = apr_bucket_alloc(len, c->bucket_alloc);
  84         for(n=0 ; n < len ; ++n)
  85             buf[n] = apr_toupper(data[n]);
  86
  87         pbktOut = apr_bucket_heap_create(buf, len, apr_bucket_free,
  88                                          c->bucket_alloc);
  89         APR_BRIGADE_INSERT_TAIL(pbbOut,pbktOut);
  90         }
  91
  92     /* Q: is there any advantage to passing a brigade for each bucket?
  93      * A: obviously, it can cut down server resource consumption, if this
  94      * experimental module was fed a file of 4MB, it would be using 8MB for
  95      * the 'read' buckets and the 'write' buckets.
  96      *
  97      * Note it is more efficient to consume (destroy) each bucket as it's
  98      * processed above than to do a single cleanup down here.  In any case,
  99      * don't let our caller pass the same buckets to us, twice;
 100      */
 101     apr_brigade_cleanup(pbbIn);
 102     return ap_pass_brigade(f->next,pbbOut);
 103     }
 104
 105 static const char *CaseFilterEnable(cmd_parms *cmd, void *dummy, int arg)
 106     {
 107     CaseFilterConfig *pConfig=ap_get_module_config(cmd->server->module_config,
 108                                                    &case_filter_module);
 109     pConfig->bEnabled=arg;
 110
 111     return NULL;
 112     }
 113
 114 static const command_rec CaseFilterCmds[] =
 115     {
 116     AP_INIT_FLAG("CaseFilter", CaseFilterEnable, NULL, RSRC_CONF,
 117                  "Run a case filter on this host"),
 118     { NULL }
 119     };
 120
 121 static void CaseFilterRegisterHooks(apr_pool_t *p)
 122     {
 123     ap_hook_insert_filter(CaseFilterInsertFilter,NULL,NULL,APR_HOOK_MIDDLE);
 124     ap_register_output_filter(s_szCaseFilterName,CaseFilterOutFilter,NULL,
 125                               AP_FTYPE_RESOURCE);
 126     }
 127
 128 module AP_MODULE_DECLARE_DATA case_filter_module =
 129 {
 130     STANDARD20_MODULE_STUFF,
 131     NULL,
 132     NULL,
 133     CaseFilterCreateServerConfig,
 134     NULL,
 135     CaseFilterCmds,
 136     CaseFilterRegisterHooks
 137 };