http_request.h 13.7 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361
/* 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.
 */

/**
 * @file http_request.h
 * @brief Apache Request library
 *
 * request.c is the code which handles the main line of request
 * processing, once a request has been read in (finding the right per-
 * directory configuration, building it if necessary, and calling all
 * the module dispatch functions in the right order).
 *
 * The pieces here which are public to the modules, allow them to learn
 * how the server would handle some other file or URI, or perhaps even
 * direct the server to serve that other file instead of the one the
 * client requested directly.
 *
 * There are two ways to do that.  The first is the sub_request mechanism,
 * which handles looking up files and URIs as adjuncts to some other
 * request (e.g., directory entries for multiviews and directory listings);
 * the lookup functions stop short of actually running the request, but
 * (e.g., for includes), a module may call for the request to be run
 * by calling run_sub_req.  The space allocated to create sub_reqs can be
 * reclaimed by calling destroy_sub_req --- be sure to copy anything you care
 * about which was allocated in its apr_pool_t elsewhere before doing this.
 */

#ifndef APACHE_HTTP_REQUEST_H
#define APACHE_HTTP_REQUEST_H

#include "apr_hooks.h"
#include "util_filter.h"

#ifdef __cplusplus
extern "C" {
#endif

#define AP_SUBREQ_NO_ARGS 0
#define AP_SUBREQ_MERGE_ARGS 1

/**
 * An internal handler used by the ap_process_request, all subrequest mechanisms
 * and the redirect mechanism.
 * @param r The request, subrequest or internal redirect to pre-process
 * @return The return code for the request
 */
AP_DECLARE(int) ap_process_request_internal(request_rec *r);

/**
 * Create a subrequest from the given URI.  This subrequest can be
 * inspected to find information about the requested URI
 * @param new_uri The URI to lookup
 * @param r The current request
 * @param next_filter The first filter the sub_request should use.  If this is
 *                    NULL, it defaults to the first filter for the main request
 * @return The new request record
 */
AP_DECLARE(request_rec *) ap_sub_req_lookup_uri(const char *new_uri,
                                                const request_rec *r,
                                                ap_filter_t *next_filter);

/**
 * Create a subrequest for the given file.  This subrequest can be
 * inspected to find information about the requested file
 * @param new_file The file to lookup
 * @param r The current request
 * @param next_filter The first filter the sub_request should use.  If this is
 *                    NULL, it defaults to the first filter for the main request
 * @return The new request record
 */
AP_DECLARE(request_rec *) ap_sub_req_lookup_file(const char *new_file,
                                              const request_rec *r,
                                              ap_filter_t *next_filter);
/**
 * Create a subrequest for the given apr_dir_read result.  This subrequest 
 * can be inspected to find information about the requested file
 * @param finfo The apr_dir_read result to lookup
 * @param r The current request
 * @param subtype What type of subrequest to perform, one of;
 * <PRE>
 *      AP_SUBREQ_NO_ARGS     ignore r->args and r->path_info
 *      AP_SUBREQ_MERGE_ARGS  merge r->args and r->path_info
 * </PRE>
 * @param next_filter The first filter the sub_request should use.  If this is
 *                    NULL, it defaults to the first filter for the main request
 * @return The new request record
 * @note The apr_dir_read flags value APR_FINFO_MIN|APR_FINFO_NAME flag is the 
 * minimum recommended query if the results will be passed to apr_dir_read.
 * The file info passed must include the name, and must have the same relative
 * directory as the current request.
 */
AP_DECLARE(request_rec *) ap_sub_req_lookup_dirent(const apr_finfo_t *finfo,
                                                   const request_rec *r,
                                                   int subtype,
                                                   ap_filter_t *next_filter);
/**
 * Create a subrequest for the given URI using a specific method.  This
 * subrequest can be inspected to find information about the requested URI
 * @param method The method to use in the new subrequest
 * @param new_uri The URI to lookup
 * @param r The current request
 * @param next_filter The first filter the sub_request should use.  If this is
 *                    NULL, it defaults to the first filter for the main request
 * @return The new request record
 */
AP_DECLARE(request_rec *) ap_sub_req_method_uri(const char *method,
                                                const char *new_uri,
                                                const request_rec *r,
                                                ap_filter_t *next_filter);
/**
 * An output filter to strip EOS buckets from sub-requests.  This always
 * has to be inserted at the end of a sub-requests filter stack.
 * @param f The current filter
 * @param bb The brigade to filter
 * @return status code
 */
AP_CORE_DECLARE_NONSTD(apr_status_t) ap_sub_req_output_filter(ap_filter_t *f,
                                                        apr_bucket_brigade *bb);

/**
 * Run the handler for the subrequest
 * @param r The subrequest to run
 * @return The return code for the subrequest
 */
AP_DECLARE(int) ap_run_sub_req(request_rec *r);

/**
 * Free the memory associated with a subrequest
 * @param r The subrequest to finish
 */
AP_DECLARE(void) ap_destroy_sub_req(request_rec *r);

/*
 * Then there's the case that you want some other request to be served
 * as the top-level request INSTEAD of what the client requested directly.
 * If so, call this from a handler, and then immediately return OK.
 */

/**
 * Redirect the current request to some other uri
 * @param new_uri The URI to replace the current request with
 * @param r The current request
 */
AP_DECLARE(void) ap_internal_redirect(const char *new_uri, request_rec *r);

/**
 * This function is designed for things like actions or CGI scripts, when
 * using AddHandler, and you want to preserve the content type across
 * an internal redirect.
 * @param new_uri The URI to replace the current request with.
 * @param r The current request
 */
AP_DECLARE(void) ap_internal_redirect_handler(const char *new_uri, request_rec *r);

/**
 * Redirect the current request to a sub_req, merging the pools
 * @param sub_req A subrequest created from this request
 * @param r The current request
 * @note the sub_req's pool will be merged into r's pool, be very careful
 * not to destroy this subrequest, it will be destroyed with the main request!
 */
AP_DECLARE(void) ap_internal_fast_redirect(request_rec *sub_req, request_rec *r);

/**
 * Can be used within any handler to determine if any authentication
 * is required for the current request
 * @param r The current request
 * @return 1 if authentication is required, 0 otherwise
 */
AP_DECLARE(int) ap_some_auth_required(request_rec *r);
 
/**
 * Determine if the current request is the main request or a subrequest
 * @param r The current request
 * @return 1 if this is the main request, 0 otherwise
 */
AP_DECLARE(int) ap_is_initial_req(request_rec *r);

/**
 * Function to set the r->mtime field to the specified value if it's later
 * than what's already there.
 * @param r The current request
 * @param dependency_mtime Time to set the mtime to
 */
AP_DECLARE(void) ap_update_mtime(request_rec *r, apr_time_t dependency_mtime);

/**
 * Add one or more methods to the list permitted to access the resource.
 * Usually executed by the content handler before the response header is
 * sent, but sometimes invoked at an earlier phase if a module knows it
 * can set the list authoritatively.  Note that the methods are ADDED
 * to any already permitted unless the reset flag is non-zero.  The
 * list is used to generate the Allow response header field when it
 * is needed.
 * @param   r     The pointer to the request identifying the resource.
 * @param   reset Boolean flag indicating whether this list should
 *                completely replace any current settings.
 * @param   ...   A NULL-terminated list of strings, each identifying a
 *                method name to add.
 * @return  None.
 */
AP_DECLARE(void) ap_allow_methods(request_rec *r, int reset, ...);

/**
 * Add one or more methods to the list permitted to access the resource.
 * Usually executed by the content handler before the response header is
 * sent, but sometimes invoked at an earlier phase if a module knows it
 * can set the list authoritatively.  Note that the methods are ADDED
 * to any already permitted unless the reset flag is non-zero.  The
 * list is used to generate the Allow response header field when it
 * is needed.
 * @param   r     The pointer to the request identifying the resource.
 * @param   reset Boolean flag indicating whether this list should
 *                completely replace any current settings.
 * @param   ...   A list of method identifiers, from the "M_" series
 *                defined in httpd.h, terminated with a value of -1
 *                (e.g., "M_GET, M_POST, M_OPTIONS, -1")
 * @return  None.
 */
AP_DECLARE(void) ap_allow_standard_methods(request_rec *r, int reset, ...);

#define MERGE_ALLOW 0
#define REPLACE_ALLOW 1

#ifdef CORE_PRIVATE
/**
 * Function called by main.c to handle first-level request 
 * @param r The current request
 */
void ap_process_request(request_rec *);

/**
 * Kill the current request
 * @param type Why the request is dieing
 * @param r The current request
 */
AP_DECLARE(void) ap_die(int type, request_rec *r);
#endif

/* Hooks */

/**
 * Gives modules a chance to create their request_config entry when the
 * request is created.
 * @param r The current request
 * @ingroup hooks
 */
AP_DECLARE_HOOK(int,create_request,(request_rec *r))

/**
 * This hook allow modules an opportunity to translate the URI into an
 * actual filename.  If no modules do anything special, the server's default
 * rules will be followed.
 * @param r The current request
 * @return OK, DECLINED, or HTTP_...
 * @ingroup hooks
 */
AP_DECLARE_HOOK(int,translate_name,(request_rec *r))

/**
 * This hook allow modules to set the per_dir_config based on their own
 * context (such as "<Proxy>" sections) and responds to contextless requests 
 * such as TRACE that need no security or filesystem mapping.
 * based on the filesystem.
 * @param r The current request
 * @return DONE (or HTTP_) if this contextless request was just fulfilled 
 * (such as TRACE), OK if this is not a file, and DECLINED if this is a file.
 * The core map_to_storage (HOOK_RUN_REALLY_LAST) will directory_walk
 * and file_walk the r->filename.
 * 
 * @ingroup hooks
 */
AP_DECLARE_HOOK(int,map_to_storage,(request_rec *r))

/**
 * This hook is used to analyze the request headers, authenticate the user,
 * and set the user information in the request record (r->user and
 * r->ap_auth_type). This hook is only run when Apache determines that
 * authentication/authorization is required for this resource (as determined
 * by the 'Require' directive). It runs after the access_checker hook, and
 * before the auth_checker hook.
 *
 * @param r The current request
 * @return OK, DECLINED, or HTTP_...
 * @ingroup hooks
 */
AP_DECLARE_HOOK(int,check_user_id,(request_rec *r))

/**
 * Allows modules to perform module-specific fixing of header fields.  This
 * is invoked just before any content-handler
 * @param r The current request
 * @return OK, DECLINED, or HTTP_...
 * @ingroup hooks
 */
AP_DECLARE_HOOK(int,fixups,(request_rec *r))
 
/**
 * This routine is called to determine and/or set the various document type
 * information bits, like Content-type (via r->content_type), language, et
 * cetera.
 * @param r the current request
 * @return OK, DECLINED, or HTTP_...
 * @ingroup hooks
 */
AP_DECLARE_HOOK(int,type_checker,(request_rec *r))

/**
 * This hook is used to apply additional access control to this resource.
 * It runs *before* a user is authenticated, so this hook is really to
 * apply additional restrictions independent of a user. It also runs
 * independent of 'Require' directive usage.
 *
 * @param r the current request
 * @return OK, DECLINED, or HTTP_...
 * @ingroup hooks
 */
AP_DECLARE_HOOK(int,access_checker,(request_rec *r))

/**
 * This hook is used to check to see if the resource being requested
 * is available for the authenticated user (r->user and r->ap_auth_type).
 * It runs after the access_checker and check_user_id hooks. Note that
 * it will *only* be called if Apache determines that access control has
 * been applied to this resource (through a 'Require' directive).
 *
 * @param r the current request
 * @return OK, DECLINED, or HTTP_...
 * @ingroup hooks
 */
AP_DECLARE_HOOK(int,auth_checker,(request_rec *r))

/**
 * This hook allows modules to insert filters for the current request
 * @param r the current request
 * @ingroup hooks
 */
AP_DECLARE_HOOK(void,insert_filter,(request_rec *r))

AP_DECLARE(int) ap_location_walk(request_rec *r);
AP_DECLARE(int) ap_directory_walk(request_rec *r);
AP_DECLARE(int) ap_file_walk(request_rec *r);

#ifdef __cplusplus
}
#endif

#endif	/* !APACHE_HTTP_REQUEST_H */