include/http_protocol.h

   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 /**
  18  * @file  http_protocol.h
  19  * @brief HTTP protocol handling
  20  *
  21  * @defgroup APACHE_CORE_PROTO HTTP Protocol Handling
  22  * @ingroup  APACHE_CORE
  23  * @{
  24  */
  25
  26 #ifndef APACHE_HTTP_PROTOCOL_H
  27 #define APACHE_HTTP_PROTOCOL_H
  28
  29 #include "httpd.h"
  30 #include "apr_hooks.h"
  31 #include "apr_portable.h"
  32 #include "apr_mmap.h"
  33 #include "apr_buckets.h"
  34 #include "util_filter.h"
  35
  36 #ifdef __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 /**
  41  * This hook allows modules to insert filters for the current error response
  42  * @param r the current request
  43  * @ingroup hooks
  44  */
  45 AP_DECLARE_HOOK(void,insert_error_filter,(request_rec *r))
  46
  47 /** This is an optimization.  We keep a record of the filter_rec that
  48  * stores the old_write filter, so that we can avoid strcmp's later.
  49  */
  50 AP_DECLARE_DATA extern ap_filter_rec_t *ap_old_write_func;
  51
  52 /*
  53  * Prototypes for routines which either talk directly back to the user,
  54  * or control the ones that eventually do.
  55  */
  56
  57 /**
  58  * Read a request and fill in the fields.
  59  * @param c The current connection
  60  * @return The new request_rec
  61  */
  62 request_rec *ap_read_request(conn_rec *c);
  63
  64 /**
  65  * Read the mime-encoded headers.
  66  * @param r The current request
  67  */
  68 AP_DECLARE(void) ap_get_mime_headers(request_rec *r);
  69
  70 /**
  71  * Optimized version of ap_get_mime_headers() that requires a
  72  * temporary brigade to work with
  73  * @param r The current request
  74  * @param bb temp brigade
  75  */
  76 AP_DECLARE(void) ap_get_mime_headers_core(request_rec *r,
  77                                           apr_bucket_brigade *bb);
  78
  79 /* Finish up stuff after a request */
  80
  81 /**
  82  * Called at completion of sending the response.  It sends the terminating
  83  * protocol information.
  84  * @param r The current request
  85  */
  86 AP_DECLARE(void) ap_finalize_request_protocol(request_rec *r);
  87
  88 /**
  89  * Send error back to client.
  90  * @param r The current request
  91  * @param recursive_error last arg indicates error status in case we get
  92  *      an error in the process of trying to deal with an ErrorDocument
  93  *      to handle some other error.  In that case, we print the default
  94  *      report for the first thing that went wrong, and more briefly report
  95  *      on the problem with the ErrorDocument.
  96  */
  97 AP_DECLARE(void) ap_send_error_response(request_rec *r, int recursive_error);
  98
  99 /* Set last modified header line from the lastmod date of the associated file.
 100  * Also, set content length.
 101  *
 102  * May return an error status, typically HTTP_NOT_MODIFIED (that when the
 103  * permit_cache argument is set to one).
 104  */
 105
 106 /**
 107  * Set the content length for this request
 108  * @param r The current request
 109  * @param length The new content length
 110  */
 111 AP_DECLARE(void) ap_set_content_length(request_rec *r, apr_off_t length);
 112
 113 /**
 114  * Set the keepalive status for this request
 115  * @param r The current request
 116  * @return 1 if keepalive can be set, 0 otherwise
 117  */
 118 AP_DECLARE(int) ap_set_keepalive(request_rec *r);
 119
 120 /**
 121  * Return the latest rational time from a request/mtime pair.  Mtime is
 122  * returned unless it's in the future, in which case we return the current time.
 123  * @param r The current request
 124  * @param mtime The last modified time
 125  * @return the latest rational time.
 126  */
 127 AP_DECLARE(apr_time_t) ap_rationalize_mtime(request_rec *r, apr_time_t mtime);
 128
 129 /**
 130  * Build the content-type that should be sent to the client from the
 131  * content-type specified.  The following rules are followed:
 132  *    - if type is NULL or "", return NULL (do not set content-type).
 133  *    - if charset adding is disabled, stop processing and return type.
 134  *    - then, if there are no parameters on type, add the default charset
 135  *    - return type
 136  * @param r The current request
 137  * @param type The content type
 138  * @return The content-type
 139  */
 140 AP_DECLARE(const char *) ap_make_content_type(request_rec *r,
 141                                               const char *type);
 142
 143 /**
 144  * Precompile metadata structures used by ap_make_content_type()
 145  * @param pool The pool to use for allocations
 146  */
 147 AP_DECLARE(void) ap_setup_make_content_type(apr_pool_t *pool);
 148
 149 /**
 150  * Construct an entity tag from the resource information.  If it's a real
 151  * file, build in some of the file characteristics.
 152  * @param r The current request
 153  * @param force_weak Force the entity tag to be weak - it could be modified
 154  *                   again in as short an interval.
 155  * @return The entity tag
 156  */
 157 AP_DECLARE(char *) ap_make_etag(request_rec *r, int force_weak);
 158
 159 /**
 160  * Set the E-tag outgoing header
 161  * @param r The current request
 162  */
 163 AP_DECLARE(void) ap_set_etag(request_rec *r);
 164
 165 /**
 166  * Set the last modified time for the file being sent
 167  * @param r The current request
 168  */
 169 AP_DECLARE(void) ap_set_last_modified(request_rec *r);
 170
 171 /**
 172  * Implements condition GET rules for HTTP/1.1 specification.  This function
 173  * inspects the client headers and determines if the response fulfills
 174  * the requirements specified.
 175  * @param r The current request
 176  * @return OK if the response fulfills the condition GET rules, some
 177  *         other status code otherwise
 178  */
 179 AP_DECLARE(int) ap_meets_conditions(request_rec *r);
 180
 181 /* Other ways to send stuff at the client.  All of these keep track
 182  * of bytes_sent automatically.  This indirection is intended to make
 183  * it a little more painless to slide things like HTTP-NG packetization
 184  * underneath the main body of the code later.  In the meantime, it lets
 185  * us centralize a bit of accounting (bytes_sent).
 186  *
 187  * These also return the number of bytes written by the call.
 188  * They should only be called with a timeout registered, for obvious reaasons.
 189  * (Ditto the send_header stuff).
 190  */
 191
 192 /**
 193  * Send an entire file to the client, using sendfile if supported by the
 194  * current platform
 195  * @param fd The file to send.
 196  * @param r The current request
 197  * @param offset Offset into the file to start sending.
 198  * @param length Amount of data to send
 199  * @param nbytes Amount of data actually sent
 200  */
 201 AP_DECLARE(apr_status_t) ap_send_fd(apr_file_t *fd, request_rec *r, apr_off_t offset,
 202                                    apr_size_t length, apr_size_t *nbytes);
 203
 204 #if APR_HAS_MMAP
 205 /**
 206  * Send an MMAP'ed file to the client
 207  * @param mm The MMAP'ed file to send
 208  * @param r The current request
 209  * @param offset The offset into the MMAP to start sending
 210  * @param length The amount of data to send
 211  * @return The number of bytes sent
 212  */
 213 AP_DECLARE(size_t) ap_send_mmap(apr_mmap_t *mm, request_rec *r, size_t offset,
 214                              size_t length);
 215 #endif
 216
 217
 218 /**
 219  * Register a new request method, and return the offset that will be
 220  * associated with that method.
 221  *
 222  * @param p        The pool to create registered method numbers from.
 223  * @param methname The name of the new method to register.
 224  * @return         Ab int value representing an offset into a bitmask.
 225  */
 226 AP_DECLARE(int) ap_method_register(apr_pool_t *p, const char *methname);
 227
 228 /**
 229  * Initialize the method_registry and allocate memory for it.
 230  *
 231  * @param p Pool to allocate memory for the registry from.
 232  */
 233 AP_DECLARE(void) ap_method_registry_init(apr_pool_t *p);
 234
 235 /**
 236  * This is a convenience macro to ease with checking a mask
 237  * against a method name.
 238  */
 239 #define AP_METHOD_CHECK_ALLOWED(mask, methname) \
 240     ((mask) & (AP_METHOD_BIT << ap_method_number_of((methname))))
 241
 242 /**
 243  * Create a new method list with the specified number of preallocated
 244  * slots for extension methods.
 245  *
 246  * @param   p       Pointer to a pool in which the structure should be
 247  *                  allocated.
 248  * @param   nelts   Number of preallocated extension slots
 249  * @return  Pointer to the newly created structure.
 250  */
 251 AP_DECLARE(ap_method_list_t *) ap_make_method_list(apr_pool_t *p, int nelts);
 252
 253
 254 /**
 255  * Copy a method list
 256  *
 257  * @param   dest List to copy to
 258  * @param   src  List to copy from
 259  */
 260 AP_DECLARE(void) ap_copy_method_list(ap_method_list_t *dest,
 261                                      ap_method_list_t *src);
 262
 263 /**
 264  * Search for an HTTP method name in an ap_method_list_t structure, and
 265  * return true if found.
 266  *
 267  * @param   method  String containing the name of the method to check.
 268  * @param   l       Pointer to a method list, such as r->allowed_methods.
 269  * @return  1 if method is in the list, otherwise 0
 270  */
 271 AP_DECLARE(int) ap_method_in_list(ap_method_list_t *l, const char *method);
 272
 273 /**
 274  * Add an HTTP method name to an ap_method_list_t structure if it isn't
 275  * already listed.
 276  *
 277  * @param   method  String containing the name of the method to check.
 278  * @param   l       Pointer to a method list, such as r->allowed_methods.
 279  * @return  None.
 280  */
 281 AP_DECLARE(void) ap_method_list_add(ap_method_list_t *l, const char *method);
 282
 283 /**
 284  * Remove an HTTP method name from an ap_method_list_t structure.
 285  *
 286  * @param   l       Pointer to a method list, such as r->allowed_methods.
 287  * @param   method  String containing the name of the method to remove.
 288  * @return  None.
 289  */
 290 AP_DECLARE(void) ap_method_list_remove(ap_method_list_t *l,
 291                                        const char *method);
 292
 293 /**
 294  * Reset a method list to be completely empty.
 295  *
 296  * @param   l       Pointer to a method list, such as r->allowed_methods.
 297  * @return  None.
 298  */
 299 AP_DECLARE(void) ap_clear_method_list(ap_method_list_t *l);
 300
 301 /**
 302  * Set the content type for this request (r->content_type).
 303  * @param r The current request
 304  * @param ct The new content type
 305  * @warning This function must be called to set r->content_type in order
 306  * for the AddOutputFilterByType directive to work correctly.
 307  */
 308 AP_DECLARE(void) ap_set_content_type(request_rec *r, const char *ct);
 309
 310 /* Hmmm... could macrofy these for now, and maybe forever, though the
 311  * definitions of the macros would get a whole lot hairier.
 312  */
 313
 314 /**
 315  * Output one character for this request
 316  * @param c the character to output
 317  * @param r the current request
 318  * @return The number of bytes sent
 319  */
 320 AP_DECLARE(int) ap_rputc(int c, request_rec *r);
 321
 322 /**
 323  * Output a string for the current request
 324  * @param str The string to output
 325  * @param r The current request
 326  * @return The number of bytes sent
 327  */
 328 AP_DECLARE(int) ap_rputs(const char *str, request_rec *r);
 329
 330 /**
 331  * Write a buffer for the current request
 332  * @param buf The buffer to write
 333  * @param nbyte The number of bytes to send from the buffer
 334  * @param r The current request
 335  * @return The number of bytes sent
 336  */
 337 AP_DECLARE(int) ap_rwrite(const void *buf, int nbyte, request_rec *r);
 338
 339 /**
 340  * Write an unspecified number of strings to the request
 341  * @param r The current request
 342  * @param ... The strings to write
 343  * @return The number of bytes sent
 344  */
 345 AP_DECLARE_NONSTD(int) ap_rvputs(request_rec *r,...);
 346
 347 /**
 348  * Output data to the client in a printf format
 349  * @param r The current request
 350  * @param fmt The format string
 351  * @param vlist The arguments to use to fill out the format string
 352  * @return The number of bytes sent
 353  */
 354 AP_DECLARE(int) ap_vrprintf(request_rec *r, const char *fmt, va_list vlist);
 355
 356 /**
 357  * Output data to the client in a printf format
 358  * @param r The current request
 359  * @param fmt The format string
 360  * @param ... The arguments to use to fill out the format string
 361  * @return The number of bytes sent
 362  */
 363 AP_DECLARE_NONSTD(int) ap_rprintf(request_rec *r, const char *fmt,...)
 364                                 __attribute__((format(printf,2,3)));
 365
 366 /**
 367  * Flush all of the data for the current request to the client
 368  * @param r The current request
 369  * @return The number of bytes sent
 370  */
 371 AP_DECLARE(int) ap_rflush(request_rec *r);
 372
 373 /**
 374  * Index used in custom_responses array for a specific error code
 375  * (only use outside protocol.c is in getting them configured).
 376  * @param status HTTP status code
 377  * @return The index of the response
 378  */
 379 AP_DECLARE(int) ap_index_of_response(int status);
 380
 381 /**
 382  * Return the Status-Line for a given status code (excluding the
 383  * HTTP-Version field). If an invalid or unknown status code is
 384  * passed, "500 Internal Server Error" will be returned.
 385  * @param status The HTTP status code
 386  * @return The Status-Line
 387  */
 388 AP_DECLARE(const char *) ap_get_status_line(int status);
 389
 390 /* Reading a block of data from the client connection (e.g., POST arg) */
 391
 392 /**
 393  * Setup the client to allow Apache to read the request body.
 394  * @param r The current request
 395  * @param read_policy How the server should interpret a chunked
 396  *                    transfer-encoding.  One of: <pre>
 397  *    REQUEST_NO_BODY          Send 413 error if message has any body
 398  *    REQUEST_CHUNKED_ERROR    Send 411 error if body without Content-Length
 399  *    REQUEST_CHUNKED_DECHUNK  If chunked, remove the chunks for me.
 400  * </pre>
 401  * @return either OK or an error code
 402  */
 403 AP_DECLARE(int) ap_setup_client_block(request_rec *r, int read_policy);
 404
 405 /**
 406  * Determine if the client has sent any data.  This also sends a
 407  * 100 Continue response to HTTP/1.1 clients, so modules should not be called
 408  * until the module is ready to read content.
 409  * @warning Never call this function more than once.
 410  * @param r The current request
 411  * @return 0 if there is no message to read, 1 otherwise
 412  */
 413 AP_DECLARE(int) ap_should_client_block(request_rec *r);
 414
 415 /**
 416  * Call this in a loop.  It will put data into a buffer and return the length
 417  * of the input block
 418  * @param r The current request
 419  * @param buffer The buffer in which to store the data
 420  * @param bufsiz The size of the buffer
 421  * @return Number of bytes inserted into the buffer.  When done reading, 0
 422  *         if EOF, or -1 if there was an error
 423  */
 424 AP_DECLARE(long) ap_get_client_block(request_rec *r, char *buffer, apr_size_t bufsiz);
 425
 426 /**
 427  * In HTTP/1.1, any method can have a body.  However, most GET handlers
 428  * wouldn't know what to do with a request body if they received one.
 429  * This helper routine tests for and reads any message body in the request,
 430  * simply discarding whatever it receives.  We need to do this because
 431  * failing to read the request body would cause it to be interpreted
 432  * as the next request on a persistent connection.
 433  * @param r The current request
 434  * @return error status if request is malformed, OK otherwise
 435  */
 436 AP_DECLARE(int) ap_discard_request_body(request_rec *r);
 437
 438 /**
 439  * Setup the output headers so that the client knows how to authenticate
 440  * itself the next time, if an authentication request failed.  This function
 441  * works for both basic and digest authentication
 442  * @param r The current request
 443  */
 444 AP_DECLARE(void) ap_note_auth_failure(request_rec *r);
 445
 446 /**
 447  * Setup the output headers so that the client knows how to authenticate
 448  * itself the next time, if an authentication request failed.  This function
 449  * works only for basic authentication
 450  * @param r The current request
 451  */
 452 AP_DECLARE(void) ap_note_basic_auth_failure(request_rec *r);
 453
 454 /**
 455  * Setup the output headers so that the client knows how to authenticate
 456  * itself the next time, if an authentication request failed.  This function
 457  * works only for digest authentication
 458  * @param r The current request
 459  */
 460 AP_DECLARE(void) ap_note_digest_auth_failure(request_rec *r);
 461
 462 /**
 463  * Get the password from the request headers
 464  * @param r The current request
 465  * @param pw The password as set in the headers
 466  * @return 0 (OK) if it set the 'pw' argument (and assured
 467  *         a correct value in r->user); otherwise it returns
 468  *         an error code, either HTTP_INTERNAL_SERVER_ERROR if things are
 469  *         really confused, HTTP_UNAUTHORIZED if no authentication at all
 470  *         seemed to be in use, or DECLINED if there was authentication but
 471  *         it wasn't Basic (in which case, the caller should presumably
 472  *         decline as well).
 473  */
 474 AP_DECLARE(int) ap_get_basic_auth_pw(request_rec *r, const char **pw);
 475
 476 /**
 477  * parse_uri: break apart the uri
 478  * @warning Side Effects:
 479  *    @li sets r->args to rest after '?' (or NULL if no '?')
 480  *    @li sets r->uri to request uri (without r->args part)
 481  *    @li sets r->hostname (if not set already) from request (scheme://host:port)
 482  * @param r The current request
 483  * @param uri The uri to break apart
 484  */
 485 AP_CORE_DECLARE(void) ap_parse_uri(request_rec *r, const char *uri);
 486
 487 /**
 488  * Get the next line of input for the request
 489  * @param s The buffer into which to read the line
 490  * @param n The size of the buffer
 491  * @param r The request
 492  * @param fold Whether to merge continuation lines
 493  * @return The length of the line, if successful
 494  *         n, if the line is too big to fit in the buffer
 495  *         -1 for miscellaneous errors
 496  */
 497 AP_DECLARE(int) ap_getline(char *s, int n, request_rec *r, int fold);
 498
 499 /**
 500  * Get the next line of input for the request
 501  *
 502  * Note: on ASCII boxes, ap_rgetline is a macro which simply calls
 503  *       ap_rgetline_core to get the line of input.
 504  *
 505  *       on EBCDIC boxes, ap_rgetline is a wrapper function which
 506  *       translates ASCII protocol lines to the local EBCDIC code page
 507  *       after getting the line of input.
 508  *
 509  * @param s Pointer to the pointer to the buffer into which the line
 510  *          should be read; if *s==NULL, a buffer of the necessary size
 511  *          to hold the data will be allocated from the request pool
 512  * @param n The size of the buffer
 513  * @param read The length of the line.
 514  * @param r The request
 515  * @param fold Whether to merge continuation lines
 516  * @param bb Working brigade to use when reading buckets
 517  * @return APR_SUCCESS, if successful
 518  *         APR_ENOSPC, if the line is too big to fit in the buffer
 519  *         Other errors where appropriate
 520  */
 521 #if APR_CHARSET_EBCDIC
 522 AP_DECLARE(apr_status_t) ap_rgetline(char **s, apr_size_t n,
 523                                      apr_size_t *read,
 524                                      request_rec *r, int fold,
 525                                      apr_bucket_brigade *bb);
 526 #else /* ASCII box */
 527 #define ap_rgetline(s, n, read, r, fold, bb) \
 528         ap_rgetline_core((s), (n), (read), (r), (fold), (bb))
 529 #endif
 530
 531 /** @see ap_rgetline */
 532 AP_DECLARE(apr_status_t) ap_rgetline_core(char **s, apr_size_t n,
 533                                           apr_size_t *read,
 534                                           request_rec *r, int fold,
 535                                           apr_bucket_brigade *bb);
 536
 537 /**
 538  * Get the method number associated with the given string, assumed to
 539  * contain an HTTP method.  Returns M_INVALID if not recognized.
 540  * @param method A string containing a valid HTTP method
 541  * @return The method number
 542  */
 543 AP_DECLARE(int) ap_method_number_of(const char *method);
 544
 545 /**
 546  * Get the method name associated with the given internal method
 547  * number.  Returns NULL if not recognized.
 548  * @param p A pool to use for temporary allocations.
 549  * @param methnum An integer value corresponding to an internal method number
 550  * @return The name corresponding to the method number
 551  */
 552 AP_DECLARE(const char *) ap_method_name_of(apr_pool_t *p, int methnum);
 553
 554
 555   /* Hooks */
 556   /*
 557    * post_read_request --- run right after read_request or internal_redirect,
 558    *                  and not run during any subrequests.
 559    */
 560 /**
 561  * This hook allows modules to affect the request immediately after the request
 562  * has been read, and before any other phases have been processes.  This allows
 563  * modules to make decisions based upon the input header fields
 564  * @param r The current request
 565  * @return OK or DECLINED
 566  */
 567 AP_DECLARE_HOOK(int,post_read_request,(request_rec *r))
 568
 569 /**
 570  * This hook allows modules to perform any module-specific logging activities
 571  * over and above the normal server things.
 572  * @param r The current request
 573  * @return OK, DECLINED, or HTTP_...
 574  */
 575 AP_DECLARE_HOOK(int,log_transaction,(request_rec *r))
 576
 577 /**
 578  * This hook allows modules to retrieve the http scheme for a request.  This
 579  * allows Apache modules to easily extend the schemes that Apache understands
 580  * @param r The current request
 581  * @return The http scheme from the request
 582  */
 583 AP_DECLARE_HOOK(const char *,http_scheme,(const request_rec *r))
 584
 585 /**
 586  * Return the default port from the current request
 587  * @param r The current request
 588  * @return The current port
 589  */
 590 AP_DECLARE_HOOK(apr_port_t,default_port,(const request_rec *r))
 591
 592 /** @see ap_bucket_type_error */
 593 typedef struct ap_bucket_error ap_bucket_error;
 594
 595 /**
 596  * @struct ap_bucket_error
 597  * @brief  A bucket referring to an HTTP error
 598  *
 599  * This bucket can be passed down the filter stack to indicate that an
 600  * HTTP error occurred while running a filter.  In order for this bucket
 601  * to be used successfully, it MUST be sent as the first bucket in the
 602  * first brigade to be sent from a given filter.
 603  */
 604 struct ap_bucket_error {
 605     /** Number of buckets using this memory */
 606     apr_bucket_refcount refcount;
 607     /** The error code */
 608     int status;
 609     /** The error string */
 610     const char    *data;
 611 };
 612
 613 /** @see ap_bucket_type_error */
 614 AP_DECLARE_DATA extern const apr_bucket_type_t ap_bucket_type_error;
 615
 616 /**
 617  * Determine if a bucket is an error bucket
 618  * @param e The bucket to inspect
 619  * @return true or false
 620  */
 621 #define AP_BUCKET_IS_ERROR(e)         (e->type == &ap_bucket_type_error)
 622
 623 /**
 624  * Make the bucket passed in an error bucket
 625  * @param b The bucket to make into an error bucket
 626  * @param error The HTTP error code to put in the bucket.
 627  * @param buf An optional error string to put in the bucket.
 628  * @param p A pool to allocate out of.
 629  * @return The new bucket, or NULL if allocation failed
 630  */
 631 AP_DECLARE(apr_bucket *) ap_bucket_error_make(apr_bucket *b, int error,
 632                 const char *buf, apr_pool_t *p);
 633
 634 /**
 635  * Create a bucket referring to an HTTP error.
 636  * @param error The HTTP error code to put in the bucket.
 637  * @param buf An optional error string to put in the bucket.
 638  * @param p A pool to allocate the error string out of.
 639  * @param list The bucket allocator from which to allocate the bucket
 640  * @return The new bucket, or NULL if allocation failed
 641  */
 642 AP_DECLARE(apr_bucket *) ap_bucket_error_create(int error, const char *buf,
 643                                                 apr_pool_t *p,
 644                                                 apr_bucket_alloc_t *list);
 645
 646 AP_DECLARE_NONSTD(apr_status_t) ap_byterange_filter(ap_filter_t *f, apr_bucket_brigade *b);
 647 AP_DECLARE_NONSTD(apr_status_t) ap_http_header_filter(ap_filter_t *f, apr_bucket_brigade *b);
 648 AP_DECLARE_NONSTD(apr_status_t) ap_content_length_filter(ap_filter_t *,
 649                                                               apr_bucket_brigade *);
 650 AP_DECLARE_NONSTD(apr_status_t) ap_old_write_filter(ap_filter_t *f, apr_bucket_brigade *b);
 651
 652 /**
 653  * Sett up the protocol fields for subsidiary requests
 654  * @param rnew New Sub Request
 655  * @param r current request
 656  */
 657 AP_DECLARE(void) ap_set_sub_req_protocol(request_rec *rnew, const request_rec *r);
 658
 659 /**
 660  * A wrapup function to keep the internal accounting straight.
 661  * Indicates that there is no more content coming.
 662  * @param sub_r Subrequest that is now compete
 663  */
 664 AP_DECLARE(void) ap_finalize_sub_req_protocol(request_rec *sub_r);
 665
 666 /**
 667  * Send an interim (HTTP 1xx) response immediately.
 668  * @param r The request
 669  * @param send_headers Whether to send&clear headers in r->headers_out
 670  */
 671 AP_DECLARE(void) ap_send_interim_response(request_rec *r, int send_headers);
 672
 673 #ifdef __cplusplus
 674 }
 675 #endif
 676
 677 #endif  /* !APACHE_HTTP_PROTOCOL_H */
 678 /** @} */