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 util_filter.h |
19 | * @brief Apache filter library |
20 | */ |
21 | |
22 | #ifndef AP_FILTER_H |
23 | #define AP_FILTER_H |
24 | |
25 | #include "apr.h" |
26 | #include "apr_buckets.h" |
27 | |
28 | #include "httpd.h" |
29 | |
30 | #if APR_HAVE_STDARG_H |
31 | #include <stdarg.h> |
32 | #endif |
33 | |
34 | #ifdef __cplusplus |
35 | extern "C" { |
36 | #endif |
37 | |
38 | /** Returned by the bottom-most filter if no data was written. |
39 | * @see ap_pass_brigade(). */ |
40 | #define AP_NOBODY_WROTE -1 |
41 | /** Returned by the bottom-most filter if no data was read. |
42 | * @see ap_get_brigade(). */ |
43 | #define AP_NOBODY_READ -2 |
44 | /** Returned when?? @bug find out when! */ |
45 | #define AP_FILTER_ERROR -3 |
46 | |
47 | /** |
48 | * @brief input filtering modes |
49 | */ |
50 | typedef enum { |
51 | /** The filter should return at most readbytes data. */ |
52 | AP_MODE_READBYTES, |
53 | /** The filter should return at most one line of CRLF data. |
54 | * (If a potential line is too long or no CRLF is found, the |
55 | * filter may return partial data). |
56 | */ |
57 | AP_MODE_GETLINE, |
58 | /** The filter should implicitly eat any CRLF pairs that it sees. */ |
59 | AP_MODE_EATCRLF, |
60 | /** The filter read should be treated as speculative and any returned |
61 | * data should be stored for later retrieval in another mode. */ |
62 | AP_MODE_SPECULATIVE, |
63 | /** The filter read should be exhaustive and read until it can not |
64 | * read any more. |
65 | * Use this mode with extreme caution. |
66 | */ |
67 | AP_MODE_EXHAUSTIVE, |
68 | /** The filter should initialize the connection if needed, |
69 | * NNTP or FTP over SSL for example. |
70 | */ |
71 | AP_MODE_INIT |
72 | } ap_input_mode_t; |
73 | |
74 | /** |
75 | * @defgroup APACHE_CORE_FILTER Filter Chain |
76 | * @ingroup APACHE_CORE |
77 | * |
78 | * Filters operate using a "chaining" mechanism. The filters are chained |
79 | * together into a sequence. When output is generated, it is passed through |
80 | * each of the filters on this chain, until it reaches the end (or "bottom") |
81 | * and is placed onto the network. |
82 | * |
83 | * The top of the chain, the code generating the output, is typically called |
84 | * a "content generator." The content generator's output is fed into the |
85 | * filter chain using the standard Apache output mechanisms: ap_rputs(), |
86 | * ap_rprintf(), ap_rwrite(), etc. |
87 | * |
88 | * Each filter is defined by a callback. This callback takes the output from |
89 | * the previous filter (or the content generator if there is no previous |
90 | * filter), operates on it, and passes the result to the next filter in the |
91 | * chain. This pass-off is performed using the ap_fc_* functions, such as |
92 | * ap_fc_puts(), ap_fc_printf(), ap_fc_write(), etc. |
93 | * |
94 | * When content generation is complete, the system will pass an "end of |
95 | * stream" marker into the filter chain. The filters will use this to flush |
96 | * out any internal state and to detect incomplete syntax (for example, an |
97 | * unterminated SSI directive). |
98 | */ |
99 | |
100 | /* forward declare the filter type */ |
101 | typedef struct ap_filter_t ap_filter_t; |
102 | |
103 | /** |
104 | * @name Filter callbacks |
105 | * |
106 | * This function type is used for filter callbacks. It will be passed a |
107 | * pointer to "this" filter, and a "bucket" containing the content to be |
108 | * filtered. |
109 | * |
110 | * In filter->ctx, the callback will find its context. This context is |
111 | * provided here, so that a filter may be installed multiple times, each |
112 | * receiving its own per-install context pointer. |
113 | * |
114 | * Callbacks are associated with a filter definition, which is specified |
115 | * by name. See ap_register_input_filter() and ap_register_output_filter() |
116 | * for setting the association between a name for a filter and its |
117 | * associated callback (and other information). |
118 | * |
119 | * If the initialization function argument passed to the registration |
120 | * functions is non-NULL, it will be called iff the filter is in the input |
121 | * or output filter chains and before any data is generated to allow the |
122 | * filter to prepare for processing. |
123 | * |
124 | * The *bucket structure (and all those referenced by ->next and ->prev) |
125 | * should be considered "const". The filter is allowed to modify the |
126 | * next/prev to insert/remove/replace elements in the bucket list, but |
127 | * the types and values of the individual buckets should not be altered. |
128 | * |
129 | * For the input and output filters, the return value of a filter should be |
130 | * an APR status value. For the init function, the return value should |
131 | * be an HTTP error code or OK if it was successful. |
132 | * |
133 | * @ingroup filter |
134 | * @{ |
135 | */ |
136 | typedef apr_status_t (*ap_out_filter_func)(ap_filter_t *f, |
137 | apr_bucket_brigade *b); |
138 | typedef apr_status_t (*ap_in_filter_func)(ap_filter_t *f, |
139 | apr_bucket_brigade *b, |
140 | ap_input_mode_t mode, |
141 | apr_read_type_e block, |
142 | apr_off_t readbytes); |
143 | typedef int (*ap_init_filter_func)(ap_filter_t *f); |
144 | |
145 | typedef union ap_filter_func { |
146 | ap_out_filter_func out_func; |
147 | ap_in_filter_func in_func; |
148 | } ap_filter_func; |
149 | |
150 | /** @} */ |
151 | |
152 | /** |
153 | * Filters have different types/classifications. These are used to group |
154 | * and sort the filters to properly sequence their operation. |
155 | * |
156 | * The types have a particular sort order, which allows us to insert them |
157 | * into the filter chain in a determistic order. Within a particular grouping, |
158 | * the ordering is equivalent to the order of calls to ap_add_*_filter(). |
159 | */ |
160 | typedef enum { |
161 | /** These filters are used to alter the content that is passed through |
162 | * them. Examples are SSI or PHP. */ |
163 | AP_FTYPE_RESOURCE = 10, |
164 | /** These filters are used to alter the content as a whole, but after all |
165 | * AP_FTYPE_RESOURCE filters are executed. These filters should not |
166 | * change the content-type. An example is deflate. */ |
167 | AP_FTYPE_CONTENT_SET = 20, |
168 | /** These filters are used to handle the protocol between server and |
169 | * client. Examples are HTTP and POP. */ |
170 | AP_FTYPE_PROTOCOL = 30, |
171 | /** These filters implement transport encodings (e.g., chunking). */ |
172 | AP_FTYPE_TRANSCODE = 40, |
173 | /** These filters will alter the content, but in ways that are |
174 | * more strongly associated with the connection. Examples are |
175 | * splitting an HTTP connection into multiple requests and |
176 | * buffering HTTP responses across multiple requests. |
177 | * |
178 | * It is important to note that these types of filters are not |
179 | * allowed in a sub-request. A sub-request's output can certainly |
180 | * be filtered by ::AP_FTYPE_RESOURCE filters, but all of the "final |
181 | * processing" is determined by the main request. */ |
182 | AP_FTYPE_CONNECTION = 50, |
183 | /** These filters don't alter the content. They are responsible for |
184 | * sending/receiving data to/from the client. */ |
185 | AP_FTYPE_NETWORK = 60 |
186 | } ap_filter_type; |
187 | |
188 | /** |
189 | * This is the request-time context structure for an installed filter (in |
190 | * the output filter chain). It provides the callback to use for filtering, |
191 | * the request this filter is associated with (which is important when |
192 | * an output chain also includes sub-request filters), the context for this |
193 | * installed filter, and the filter ordering/chaining fields. |
194 | * |
195 | * Filter callbacks are free to use ->ctx as they please, to store context |
196 | * during the filter process. Generally, this is superior over associating |
197 | * the state directly with the request. A callback should not change any of |
198 | * the other fields. |
199 | */ |
200 | |
201 | typedef struct ap_filter_rec_t ap_filter_rec_t; |
202 | typedef struct ap_filter_provider_t ap_filter_provider_t; |
203 | |
204 | /** |
205 | * @brief This structure is used for recording information about the |
206 | * registered filters. It associates a name with the filter's callback |
207 | * and filter type. |
208 | * |
209 | * At the moment, these are simply linked in a chain, so a ->next pointer |
210 | * is available. |
211 | * |
212 | * It is used for any filter that can be inserted in the filter chain. |
213 | * This may be either a httpd-2.0 filter or a mod_filter harness. |
214 | * In the latter case it contains dispatch, provider and protocol information. |
215 | * In the former case, the new fields (from dispatch) are ignored. |
216 | */ |
217 | struct ap_filter_rec_t { |
218 | /** The registered name for this filter */ |
219 | const char *name; |
220 | |
221 | /** The function to call when this filter is invoked. */ |
222 | ap_filter_func filter_func; |
223 | |
224 | /** The function to call directly before the handlers are invoked |
225 | * for a request. The init function is called once directly |
226 | * before running the handlers for a request or subrequest. The |
227 | * init function is never called for a connection filter (with |
228 | * ftype >= AP_FTYPE_CONNECTION). Any use of this function for |
229 | * filters for protocols other than HTTP is specified by the |
230 | * module supported that protocol. |
231 | */ |
232 | ap_init_filter_func filter_init_func; |
233 | |
234 | /** The type of filter, either AP_FTYPE_CONTENT or AP_FTYPE_CONNECTION. |
235 | * An AP_FTYPE_CONTENT filter modifies the data based on information |
236 | * found in the content. An AP_FTYPE_CONNECTION filter modifies the |
237 | * data based on the type of connection. |
238 | */ |
239 | ap_filter_type ftype; |
240 | |
241 | /** The next filter_rec in the list */ |
242 | struct ap_filter_rec_t *next; |
243 | |
244 | /** Providers for this filter */ |
245 | ap_filter_provider_t *providers; |
246 | |
247 | /** Trace level for this filter */ |
248 | int debug; |
249 | |
250 | /** Protocol flags for this filter */ |
251 | unsigned int proto_flags; |
252 | }; |
253 | |
254 | /** |
255 | * @brief The representation of a filter chain. |
256 | * |
257 | * Each request has a list |
258 | * of these structures which are called in turn to filter the data. Sub |
259 | * requests get an exact copy of the main requests filter chain. |
260 | */ |
261 | struct ap_filter_t { |
262 | /** The internal representation of this filter. This includes |
263 | * the filter's name, type, and the actual function pointer. |
264 | */ |
265 | ap_filter_rec_t *frec; |
266 | |
267 | /** A place to store any data associated with the current filter */ |
268 | void *ctx; |
269 | |
270 | /** The next filter in the chain */ |
271 | ap_filter_t *next; |
272 | |
273 | /** The request_rec associated with the current filter. If a sub-request |
274 | * adds filters, then the sub-request is the request associated with the |
275 | * filter. |
276 | */ |
277 | request_rec *r; |
278 | |
279 | /** The conn_rec associated with the current filter. This is analogous |
280 | * to the request_rec, except that it is used for input filtering. |
281 | */ |
282 | conn_rec *c; |
283 | }; |
284 | |
285 | /** |
286 | * Get the current bucket brigade from the next filter on the filter |
287 | * stack. The filter returns an apr_status_t value. If the bottom-most |
288 | * filter doesn't read from the network, then ::AP_NOBODY_READ is returned. |
289 | * The bucket brigade will be empty when there is nothing left to get. |
290 | * @param filter The next filter in the chain |
291 | * @param bucket The current bucket brigade. The original brigade passed |
292 | * to ap_get_brigade() must be empty. |
293 | * @param mode The way in which the data should be read |
294 | * @param block How the operations should be performed |
295 | * ::APR_BLOCK_READ, ::APR_NONBLOCK_READ |
296 | * @param readbytes How many bytes to read from the next filter. |
297 | */ |
298 | AP_DECLARE(apr_status_t) ap_get_brigade(ap_filter_t *filter, |
299 | apr_bucket_brigade *bucket, |
300 | ap_input_mode_t mode, |
301 | apr_read_type_e block, |
302 | apr_off_t readbytes); |
303 | |
304 | /** |
305 | * Pass the current bucket brigade down to the next filter on the filter |
306 | * stack. The filter returns an apr_status_t value. If the bottom-most |
307 | * filter doesn't write to the network, then ::AP_NOBODY_WROTE is returned. |
308 | * The caller relinquishes ownership of the brigade. |
309 | * @param filter The next filter in the chain |
310 | * @param bucket The current bucket brigade |
311 | */ |
312 | AP_DECLARE(apr_status_t) ap_pass_brigade(ap_filter_t *filter, |
313 | apr_bucket_brigade *bucket); |
314 | |
315 | /** |
316 | * This function is used to register an input filter with the system. |
317 | * After this registration is performed, then a filter may be added |
318 | * into the filter chain by using ap_add_input_filter() and simply |
319 | * specifying the name. |
320 | * |
321 | * @param name The name to attach to the filter function |
322 | * @param filter_func The filter function to name |
323 | * @param filter_init The function to call before the filter handlers |
324 | are invoked |
325 | * @param ftype The type of filter function, either ::AP_FTYPE_CONTENT or |
326 | * ::AP_FTYPE_CONNECTION |
327 | * @see add_input_filter() |
328 | */ |
329 | AP_DECLARE(ap_filter_rec_t *) ap_register_input_filter(const char *name, |
330 | ap_in_filter_func filter_func, |
331 | ap_init_filter_func filter_init, |
332 | ap_filter_type ftype); |
333 | |
334 | /** |
335 | * This function is used to register an output filter with the system. |
336 | * After this registration is performed, then a filter may be added |
337 | * into the filter chain by using ap_add_output_filter() and simply |
338 | * specifying the name. It may also be used as a provider under mod_filter. |
339 | * This is (equivalent to) ap_register_output_filter_protocol with |
340 | * proto_flags=0, and is retained for back-compatibility with 2.0 modules. |
341 | * |
342 | * @param name The name to attach to the filter function |
343 | * @param filter_func The filter function to name |
344 | * @param filter_init The function to call before the filter handlers |
345 | * are invoked |
346 | * @param ftype The type of filter function, either ::AP_FTYPE_CONTENT or |
347 | * ::AP_FTYPE_CONNECTION |
348 | * @see ap_add_output_filter() |
349 | */ |
350 | AP_DECLARE(ap_filter_rec_t *) ap_register_output_filter(const char *name, |
351 | ap_out_filter_func filter_func, |
352 | ap_init_filter_func filter_init, |
353 | ap_filter_type ftype); |
354 | |
355 | /* For httpd-2.2 I suggest replacing the above with |
356 | #define ap_register_output_filter(name,ffunc,init,ftype) \ |
357 | ap_register_output_filter_protocol(name,ffunc,init,ftype,0) |
358 | */ |
359 | |
360 | /** |
361 | * This function is used to register an output filter with the system. |
362 | * After this registration is performed, then a filter may be added |
363 | * into the filter chain by using ap_add_output_filter() and simply |
364 | * specifying the name. It may also be used as a provider under mod_filter. |
365 | * |
366 | * @param name The name to attach to the filter function |
367 | * @param filter_func The filter function to name |
368 | * @param filter_init The function to call before the filter handlers |
369 | * are invoked |
370 | * @param ftype The type of filter function, either ::AP_FTYPE_CONTENT or |
371 | * ::AP_FTYPE_CONNECTION |
372 | * @param proto_flags Protocol flags: logical OR of AP_FILTER_PROTO_* bits |
373 | * @see ap_add_output_filter() |
374 | */ |
375 | AP_DECLARE(ap_filter_rec_t *) ap_register_output_filter_protocol( |
376 | const char *name, |
377 | ap_out_filter_func filter_func, |
378 | ap_init_filter_func filter_init, |
379 | ap_filter_type ftype, |
380 | unsigned int proto_flags); |
381 | |
382 | /** |
383 | * Adds a named filter into the filter chain on the specified request record. |
384 | * The filter will be installed with the specified context pointer. |
385 | * |
386 | * Filters added in this way will always be placed at the end of the filters |
387 | * that have the same type (thus, the filters have the same order as the |
388 | * calls to ap_add_filter). If the current filter chain contains filters |
389 | * from another request, then this filter will be added before those other |
390 | * filters. |
391 | * |
392 | * To re-iterate that last comment. This function is building a FIFO |
393 | * list of filters. Take note of that when adding your filter to the chain. |
394 | * |
395 | * @param name The name of the filter to add |
396 | * @param ctx Context data to provide to the filter |
397 | * @param r The request to add this filter for (or NULL if it isn't associated with a request) |
398 | * @param c The connection to add the fillter for |
399 | */ |
400 | AP_DECLARE(ap_filter_t *) ap_add_input_filter(const char *name, void *ctx, |
401 | request_rec *r, conn_rec *c); |
402 | |
403 | /** |
404 | * Variant of ap_add_input_filter() that accepts a registered filter handle |
405 | * (as returned by ap_register_input_filter()) rather than a filter name |
406 | * |
407 | * @param f The filter handle to add |
408 | * @param ctx Context data to provide to the filter |
409 | * @param r The request to add this filter for (or NULL if it isn't associated with a request) |
410 | * @param c The connection to add the fillter for |
411 | */ |
412 | AP_DECLARE(ap_filter_t *) ap_add_input_filter_handle(ap_filter_rec_t *f, |
413 | void *ctx, |
414 | request_rec *r, |
415 | conn_rec *c); |
416 | |
417 | /** |
418 | * Returns the filter handle for use with ap_add_input_filter_handle. |
419 | * |
420 | * @param name The filter name to look up |
421 | */ |
422 | AP_DECLARE(ap_filter_rec_t *) ap_get_input_filter_handle(const char *name); |
423 | |
424 | /** |
425 | * Add a filter to the current request. Filters are added in a FIFO manner. |
426 | * The first filter added will be the first filter called. |
427 | * @param name The name of the filter to add |
428 | * @param ctx Context data to set in the filter |
429 | * @param r The request to add this filter for (or NULL if it isn't associated with a request) |
430 | * @param c The connection to add this filter for |
431 | */ |
432 | AP_DECLARE(ap_filter_t *) ap_add_output_filter(const char *name, void *ctx, |
433 | request_rec *r, conn_rec *c); |
434 | |
435 | /** |
436 | * Variant of ap_add_output_filter() that accepts a registered filter handle |
437 | * (as returned by ap_register_output_filter()) rather than a filter name |
438 | * |
439 | * @param f The filter handle to add |
440 | * @param r The request to add this filter for (or NULL if it isn't associated with a request) |
441 | * @param c The connection to add the fillter for |
442 | */ |
443 | AP_DECLARE(ap_filter_t *) ap_add_output_filter_handle(ap_filter_rec_t *f, |
444 | void *ctx, |
445 | request_rec *r, |
446 | conn_rec *c); |
447 | |
448 | /** |
449 | * Returns the filter handle for use with ap_add_output_filter_handle. |
450 | * |
451 | * @param name The filter name to look up |
452 | */ |
453 | AP_DECLARE(ap_filter_rec_t *) ap_get_output_filter_handle(const char *name); |
454 | |
455 | /** |
456 | * Remove an input filter from either the request or connection stack |
457 | * it is associated with. |
458 | * @param f The filter to remove |
459 | */ |
460 | |
461 | AP_DECLARE(void) ap_remove_input_filter(ap_filter_t *f); |
462 | |
463 | /** |
464 | * Remove an output filter from either the request or connection stack |
465 | * it is associated with. |
466 | * @param f The filter to remove |
467 | */ |
468 | |
469 | AP_DECLARE(void) ap_remove_output_filter(ap_filter_t *f); |
470 | |
471 | /* The next two filters are for abstraction purposes only. They could be |
472 | * done away with, but that would require that we break modules if we ever |
473 | * want to change our filter registration method. The basic idea, is that |
474 | * all filters have a place to store data, the ctx pointer. These functions |
475 | * fill out that pointer with a bucket brigade, and retrieve that data on |
476 | * the next call. The nice thing about these functions, is that they |
477 | * automatically concatenate the bucket brigades together for you. This means |
478 | * that if you have already stored a brigade in the filters ctx pointer, then |
479 | * when you add more it will be tacked onto the end of that brigade. When |
480 | * you retrieve data, if you pass in a bucket brigade to the get function, |
481 | * it will append the current brigade onto the one that you are retrieving. |
482 | */ |
483 | |
484 | /** |
485 | * prepare a bucket brigade to be setaside. If a different brigade was |
486 | * set-aside earlier, then the two brigades are concatenated together. |
487 | * @param f The current filter |
488 | * @param save_to The brigade that was previously set-aside. Regardless, the |
489 | * new bucket brigade is returned in this location. |
490 | * @param b The bucket brigade to save aside. This brigade is always empty |
491 | * on return |
492 | * @param p Ensure that all data in the brigade lives as long as this pool |
493 | */ |
494 | AP_DECLARE(apr_status_t) ap_save_brigade(ap_filter_t *f, |
495 | apr_bucket_brigade **save_to, |
496 | apr_bucket_brigade **b, apr_pool_t *p); |
497 | |
498 | /** |
499 | * Flush function for apr_brigade_* calls. This calls ap_pass_brigade |
500 | * to flush the brigade if the brigade buffer overflows. |
501 | * @param bb The brigade to flush |
502 | * @param ctx The filter to pass the brigade to |
503 | * @note this function has nothing to do with FLUSH buckets. It is simply |
504 | * a way to flush content out of a brigade and down a filter stack. |
505 | */ |
506 | AP_DECLARE_NONSTD(apr_status_t) ap_filter_flush(apr_bucket_brigade *bb, |
507 | void *ctx); |
508 | |
509 | /** |
510 | * Flush the current brigade down the filter stack. |
511 | * @param f The filter we are passing to |
512 | * @param bb The brigade to flush |
513 | */ |
514 | AP_DECLARE(apr_status_t) ap_fflush(ap_filter_t *f, apr_bucket_brigade *bb); |
515 | |
516 | /** |
517 | * Write a buffer for the current filter, buffering if possible. |
518 | * @param f the filter we are writing to |
519 | * @param bb The brigade to buffer into |
520 | * @param data The data to write |
521 | * @param nbyte The number of bytes in the data |
522 | */ |
523 | #define ap_fwrite(f, bb, data, nbyte) \ |
524 | apr_brigade_write : enter=0, leave=0
apr_brigade_write : /usr/include/apr-1/apr_buckets.h line=810 column=27
apr_brigade_write(bb, ap_filter_flush : include/util_filter.h line=506 column=33
ap_filter_flush, f, data, nbyte) |
525 | |
526 | /** |
527 | * Write a buffer for the current filter, buffering if possible. |
528 | * @param f the filter we are writing to |
529 | * @param bb The brigade to buffer into |
530 | * @param str The string to write |
531 | */ |
532 | #define ap_fputs(f, bb, str) \ |
533 | apr_brigade_puts : enter=0, leave=0
apr_brigade_puts : /usr/include/apr-1/apr_buckets.h line=837 column=27
apr_brigade_puts(bb, ap_filter_flush : include/util_filter.h line=506 column=33
ap_filter_flush, f, str) |
534 | |
535 | /** |
536 | * Write a character for the current filter, buffering if possible. |
537 | * @param f the filter we are writing to |
538 | * @param bb The brigade to buffer into |
539 | * @param c The character to write |
540 | */ |
541 | #define ap_fputc(f, bb, c) \ |
542 | apr_brigade_putc(bb, ap_filter_flush, f, c) |
543 | |
544 | /** |
545 | * Write an unspecified number of strings to the current filter |
546 | * @param f the filter we are writing to |
547 | * @param bb The brigade to buffer into |
548 | * @param ... The strings to write |
549 | */ |
550 | AP_DECLARE_NONSTD(apr_status_t) ap_fputstrs(ap_filter_t *f, |
551 | apr_bucket_brigade *bb, |
552 | ...); |
553 | |
554 | /** |
555 | * Output data to the filter in printf format |
556 | * @param f the filter we are writing to |
557 | * @param bb The brigade to buffer into |
558 | * @param fmt The format string |
559 | * @param ... The argumets to use to fill out the format string |
560 | */ |
561 | AP_DECLARE_NONSTD(apr_status_t) ap_fprintf(ap_filter_t *f, |
562 | apr_bucket_brigade *bb, |
563 | const char *fmt, |
564 | ...) |
565 | __attribute__((format(printf,3,4))); |
566 | |
567 | /** |
568 | * set protocol requirements for an output content filter |
569 | * (only works with AP_FTYPE_RESOURCE and AP_FTYPE_CONTENT_SET) |
570 | * @param f the filter in question |
571 | * @param proto_flags Logical OR of AP_FILTER_PROTO_* bits |
572 | */ |
573 | AP_DECLARE(void) ap_filter_protocol(ap_filter_t* f, unsigned int proto_flags); |
574 | |
575 | /** Filter changes contents (so invalidating checksums/etc) */ |
576 | #define AP_FILTER_PROTO_CHANGE 0x1 |
577 | |
578 | /** Filter changes length of contents (so invalidating content-length/etc) */ |
579 | #define AP_FILTER_PROTO_CHANGE_LENGTH 0x2 |
580 | |
581 | /** Filter requires complete input and can't work on byteranges */ |
582 | #define AP_FILTER_PROTO_NO_BYTERANGE 0x4 |
583 | |
584 | /** Filter should not run in a proxy */ |
585 | #define AP_FILTER_PROTO_NO_PROXY 0x8 |
586 | |
587 | /** Filter makes output non-cacheable */ |
588 | #define AP_FILTER_PROTO_NO_CACHE 0x10 |
589 | |
590 | /** Filter is incompatible with "Cache-Control: no-transform" */ |
591 | #define AP_FILTER_PROTO_TRANSFORM 0x20 |
592 | |
593 | #ifdef __cplusplus |
594 | } |
595 | #endif |
596 | |
597 | #endif /* !AP_FILTER_H */ |
598 | [EOF] |