[users@httpd] Request Filter

[living liquid | Christian Meisinger <c....@livingliquid.com>]

i try to write a filter which can block request.
i copied and modified mod_authn_dbd which has already some SQL stuff.
my problem is that i can't get any configuration settings.
WHATEVERRequestConfig->ipCheck should be a string to a SQL query.

WHATEVERIPCheckPrepare() is called.

however in WHATEVERRequest() ipCheck is NULL

??? any ideas

i tried to use <Directory> or <Location> no help.



mod_WHATEVER.c
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  * 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
  *
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  * 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.
  */

/*
  * WHATEVER request filer
  */
#include "httpd.h"
#include "http_config.h"
#include "http_core.h"
#include "apr_buckets.h"
#include "apr_general.h"
#include "apr_lib.h"
#include "util_filter.h"
#include "http_request.h"
#include "http_log.h"
#include "apr_lib.h"
#include "apr_dbd.h"
#include "mod_dbd.h"
#include "mod_auth.h"

#include <ctype.h>


/* optional function - look it up once in post_config */
static ap_dbd_t * (*WHATEVER_acquire_fn)(request_rec*) = NULL;
static void       (*WHATEVER_prepare_fn)(server_rec*, const char*, const char*) = NULL;


typedef struct
{
     int    enabled;
     char * ipCheck;
} WHATEVERRequestConfig;


static void *WHATEVERRequestDirConfigCreate(apr_pool_t *p, char *dirspec)
{
     WHATEVERRequestConfig *conf = (WHATEVERRequestConfig *) apr_pcalloc(p, sizeof(WHATEVERRequestConfig));

     conf->enabled = 1;
     conf->ipCheck = NULL;

     return (void *) conf;
}

static const char *WHATEVERIPCheckPrepare(cmd_parms *cmd, void *conf, const char *query)
{
     static unsigned int WHATEVER_num = 0;

     if (WHATEVER_prepare_fn == NULL)
     {
         WHATEVER_prepare_fn = APR_RETRIEVE_OPTIONAL_FN(ap_dbd_prepare);
         if (WHATEVER_prepare_fn == NULL)
         {
             return "You must load mod_dbd to enable AuthDBD functions";
         }
         WHATEVER_acquire_fn = APR_RETRIEVE_OPTIONAL_FN(ap_dbd_acquire);
     }

     const char* label = apr_psprintf(cmd->pool, "mod_WHATEVER_%d", ++WHATEVER_num);

     WHATEVER_prepare_fn(cmd->server, query, label);

     ap_set_string_slot(cmd, conf, label);

     WHATEVERRequestConfig *tXRCfg = (WHATEVERRequestConfig *)conf;
     ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, "WHATEVERIPCheckPrepare: %s = %s / %s", label, query, 
tXRCfg->ipCheck);

     /* save the label here for our own use */
     return NULL;
}

static const command_rec WHATEVERRequestCmds[] =
{
     AP_INIT_FLAG("WHATEVEREnabled", ap_set_flag_slot, (void *)APR_OFFSETOF(WHATEVERRequestConfig, enabled),
         OR_AUTHCFG, "Enable WHATEVER  filter"),
     AP_INIT_TAKE1("WHATEVERIPCheck", WHATEVERIPCheckPrepare, (void *)APR_OFFSETOF(WHATEVERRequestConfig, ipCheck),
         OR_AUTHCFG, "Query used to check for a blocked IP"),
     { NULL }
};


module AP_MODULE_DECLARE_DATA WHATEVER_module;


static apr_status_t WHATEVERRequest(request_rec *r)
{
     WHATEVERRequestConfig *conf = ap_get_module_config(r->per_dir_config, &WHATEVER_module);

     if ( !conf->enabled )
     {
         ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "WHATEVERRequest is disabled %d", conf->enabled);
         return DECLINED;
     }

     apr_dbd_prepared_t *statement;
     apr_dbd_results_t *res = NULL;
     apr_dbd_row_t *row = NULL;
     apr_status_t rv;

     // the connection struct is explained at the end of this file
     conn_rec *c = r->connection;

      apr_pool_t *p = NULL;
      if (r != NULL)
      {
          p = r->pool;
      }
      else if (c != NULL)
      {
          p = c->pool;
      }

      ap_dbd_t *dbd = WHATEVER_acquire_fn(r);
      if (dbd == NULL)
      {
          ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "Error looking up %s in database", c->remote_ip);
          return AUTH_GENERAL_ERROR;
      }

      if (conf->ipCheck == NULL)
      {
           ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "No WHATEVERIPCheck has been specified.");
           return AUTH_GENERAL_ERROR;
      }

      statement = apr_hash_get(dbd->prepared, conf->ipCheck, APR_HASH_KEY_STRING);
      if (statement == NULL)
      {
          ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                        "A prepared statement could not be found for WHATEVERRequest, key '%s'.", conf->ipCheck);
          return AUTH_GENERAL_ERROR;
      }

//     if (apr_dbd_pvselect(dbd->driver, r->pool, dbd->handle, &res, statement, 0, c->remote_ip, NULL) != 0)
//     {
//         ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "Error looking up %s in database", c->remote_ip);
//         return AUTH_GENERAL_ERROR;
//     }
//     for (rv = apr_dbd_get_row(dbd->driver, r->pool, res, &row, -1);
//          rv != -1;
//          rv = apr_dbd_get_row(dbd->driver, r->pool, res, &row, -1))
//     {
//         /* we can't break out here or row won't get cleaned up */
//         ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "Entry: %s", apr_dbd_get_entry(dbd->driver, row, 0));
//         return HTTP_FORBIDDEN;
//     }

      ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, "IP '%s' is OK", c->remote_ip);

      return OK;
}


static void WHATEVERRequestRegisterHooks(apr_pool_t *p)
{
     ap_hook_post_read_request(WHATEVERRequest, NULL, NULL, APR_HOOK_FIRST);
}

module AP_MODULE_DECLARE_DATA WHATEVER_module =
{
     STANDARD20_MODULE_STUFF,
     WHATEVERRequestDirConfigCreate,
     NULL,
     NULL,
     NULL,
     WHATEVERRequestCmds,
     WHATEVERRequestRegisterHooks
};

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Re: [users@httpd] Request Filter

[Joshua Slive <jo...@slive.ca>]

On Tue, Jun 3, 2008 at 3:34 AM, living liquid | Christian Meisinger
<c....@livingliquid.com> wrote:
> i try to write a filter which can block request.
> i copied and modified mod_authn_dbd which has already some SQL stuff.
> my problem is that i can't get any configuration settings.

I recommend you try the module developers mailing list, where this
question is more likely to find an answer:
http://httpd.apache.org/lists.html#modules-dev

Joshua.

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