1
2 /*
3 * Copyright (C) Igor Sysoev
4 * Copyright (C) Nginx, Inc.
5 */
6
7
8 #include <ngx_config.h>
9 #include <ngx_core.h>
10 #include <ngx_http.h>
11
12
13 typedef struct ngx_http_header_val_s ngx_http_header_val_t;
14
15 typedef ngx_int_t (*ngx_http_set_header_pt)(ngx_http_request_t *r,
16 ngx_http_header_val_t *hv, ngx_str_t *value);
17
18
19 typedef struct {
20 ngx_str_t name;
21 ngx_uint_t offset;
22 ngx_http_set_header_pt handler;
23 } ngx_http_set_header_t;
24
25
26 struct ngx_http_header_val_s {
27 ngx_http_complex_value_t value;
28 ngx_str_t key;
29 ngx_http_set_header_pt handler;
30 ngx_uint_t offset;
31 };
32
33
34 typedef enum {
35 NGX_HTTP_EXPIRES_OFF,
36 NGX_HTTP_EXPIRES_EPOCH,
37 NGX_HTTP_EXPIRES_MAX,
38 NGX_HTTP_EXPIRES_ACCESS,
39 NGX_HTTP_EXPIRES_MODIFIED,
40 NGX_HTTP_EXPIRES_DAILY,
41 NGX_HTTP_EXPIRES_UNSET
42 } ngx_http_expires_t;
43
44
45 typedef struct {
46 ngx_http_expires_t expires;
47 time_t expires_time;
48 ngx_array_t *headers;
49 } ngx_http_headers_conf_t;
50
51
52 static ngx_int_t ngx_http_set_expires(ngx_http_request_t *r,
53 ngx_http_headers_conf_t *conf);
54 static ngx_int_t ngx_http_add_cache_control(ngx_http_request_t *r,
55 ngx_http_header_val_t *hv, ngx_str_t *value);
56 static ngx_int_t ngx_http_add_header(ngx_http_request_t *r,
57 ngx_http_header_val_t *hv, ngx_str_t *value);
58 static ngx_int_t ngx_http_set_last_modified(ngx_http_request_t *r,
59 ngx_http_header_val_t *hv, ngx_str_t *value);
60 static ngx_int_t ngx_http_set_response_header(ngx_http_request_t *r,
61 ngx_http_header_val_t *hv, ngx_str_t *value);
62
63 static void *ngx_http_headers_create_conf(ngx_conf_t *cf);
64 static char *ngx_http_headers_merge_conf(ngx_conf_t *cf,
65 void *parent, void *child);
66 static ngx_int_t ngx_http_headers_filter_init(ngx_conf_t *cf);
67 static char *ngx_http_headers_expires(ngx_conf_t *cf, ngx_command_t *cmd,
68 void *conf);
69 static char *ngx_http_headers_add(ngx_conf_t *cf, ngx_command_t *cmd,
70 void *conf);
71
72
73 static ngx_http_set_header_t ngx_http_set_headers[] = {
74
75 { ngx_string("Cache-Control"), 0, ngx_http_add_cache_control },
76
77 { ngx_string("Last-Modified"),
78 offsetof(ngx_http_headers_out_t, last_modified),
79 ngx_http_set_last_modified },
80
81 { ngx_string("ETag"),
82 offsetof(ngx_http_headers_out_t, etag),
83 ngx_http_set_response_header },
84
85 { ngx_null_string, 0, NULL }
86 };
87
88
89 static ngx_command_t ngx_http_headers_filter_commands[] = {
90
91 { ngx_string("expires"),
92 NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF
93 |NGX_CONF_TAKE12,
94 ngx_http_headers_expires,
95 NGX_HTTP_LOC_CONF_OFFSET,
96 0,
97 NULL},
98
99 { ngx_string("add_header"),
100 NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF
101 |NGX_CONF_TAKE2,
102 ngx_http_headers_add,
103 NGX_HTTP_LOC_CONF_OFFSET,
104 0,
105 NULL},
106
107 ngx_null_command
108 };
109
110
111 static ngx_http_module_t ngx_http_headers_filter_module_ctx = {
112 NULL, /* preconfiguration */
113 ngx_http_headers_filter_init, /* postconfiguration */
114
115 NULL, /* create main configuration */
116 NULL, /* init main configuration */
117
118 NULL, /* create server configuration */
119 NULL, /* merge server configuration */
120
121 ngx_http_headers_create_conf, /* create location configuration */
122 ngx_http_headers_merge_conf /* merge location configuration */
123 };
124
125
126 ngx_module_t ngx_http_headers_filter_module = {
127 NGX_MODULE_V1,
128 &ngx_http_headers_filter_module_ctx, /* module context */
129 ngx_http_headers_filter_commands, /* module directives */
130 NGX_HTTP_MODULE, /* module type */
131 NULL, /* init master */
132 NULL, /* init module */
133 NULL, /* init process */
134 NULL, /* init thread */
135 NULL, /* exit thread */
136 NULL, /* exit process */
137 NULL, /* exit master */
138 NGX_MODULE_V1_PADDING
139 };
140
141
142 static ngx_http_output_header_filter_pt ngx_http_next_header_filter;
143
144
145 static ngx_int_t
146 ngx_http_headers_filter(ngx_http_request_t *r)
147 {
148 ngx_str_t value;
149 ngx_uint_t i;
150 ngx_http_header_val_t *h;
151 ngx_http_headers_conf_t *conf;
152
153 conf = ngx_http_get_module_loc_conf(r, ngx_http_headers_filter_module);
154
155 if ((conf->expires == NGX_HTTP_EXPIRES_OFF && conf->headers == NULL)
156 || r != r->main
157 || (r->headers_out.status != NGX_HTTP_OK
158 && r->headers_out.status != NGX_HTTP_CREATED
159 && r->headers_out.status != NGX_HTTP_NO_CONTENT
160 && r->headers_out.status != NGX_HTTP_PARTIAL_CONTENT
161 && r->headers_out.status != NGX_HTTP_MOVED_PERMANENTLY
162 && r->headers_out.status != NGX_HTTP_MOVED_TEMPORARILY
163 && r->headers_out.status != NGX_HTTP_SEE_OTHER
164 && r->headers_out.status != NGX_HTTP_NOT_MODIFIED
165 && r->headers_out.status != NGX_HTTP_TEMPORARY_REDIRECT))
166 {
167 return ngx_http_next_header_filter(r);
168 }
169
170 if (conf->expires != NGX_HTTP_EXPIRES_OFF) {
171 if (ngx_http_set_expires(r, conf) != NGX_OK) {
172 return NGX_ERROR;
173 }
174 }
175
176 if (conf->headers) {
177 h = conf->headers->elts;
178 for (i = 0; i < conf->headers->nelts; i++) {
179
180 if (ngx_http_complex_value(r, &h[i].value, &value) != NGX_OK) {
181 return NGX_ERROR;
182 }
183
184 if (h[i].handler(r, &h[i], &value) != NGX_OK) {
185 return NGX_ERROR;
186 }
187 }
188 }
189
190 return ngx_http_next_header_filter(r);
191 }
192
193
194 static ngx_int_t
195 ngx_http_set_expires(ngx_http_request_t *r, ngx_http_headers_conf_t *conf)
196 {
197 size_t len;
198 time_t now, expires_time, max_age;
199 ngx_uint_t i;
200 ngx_table_elt_t *expires, *cc, **ccp;
201
202 expires = r->headers_out.expires;
203
204 if (expires == NULL) {
205
206 expires = ngx_list_push(&r->headers_out.headers);
207 if (expires == NULL) {
208 return NGX_ERROR;
209 }
210
211 r->headers_out.expires = expires;
212
213 expires->hash = 1;
214 ngx_str_set(&expires->key, "Expires");
215 }
216
217 len = sizeof("Mon, 28 Sep 1970 06:00:00 GMT");
218 expires->value.len = len - 1;
219
220 ccp = r->headers_out.cache_control.elts;
221
222 if (ccp == NULL) {
223
224 if (ngx_array_init(&r->headers_out.cache_control, r->pool,
225 1, sizeof(ngx_table_elt_t *))
226 != NGX_OK)
227 {
228 return NGX_ERROR;
229 }
230
231 ccp = ngx_array_push(&r->headers_out.cache_control);
232 if (ccp == NULL) {
233 return NGX_ERROR;
234 }
235
236 cc = ngx_list_push(&r->headers_out.headers);
237 if (cc == NULL) {
238 return NGX_ERROR;
239 }
240
241 cc->hash = 1;
242 ngx_str_set(&cc->key, "Cache-Control");
243 *ccp = cc;
244
245 } else {
246 for (i = 1; i < r->headers_out.cache_control.nelts; i++) {
247 ccp[i]->hash = 0;
248 }
249
250 cc = ccp[0];
251 }
252
253 if (conf->expires == NGX_HTTP_EXPIRES_EPOCH) {
254 expires->value.data = (u_char *) "Thu, 01 Jan 1970 00:00:01 GMT";
255 ngx_str_set(&cc->value, "no-cache");
256 return NGX_OK;
257 }
258
259 if (conf->expires == NGX_HTTP_EXPIRES_MAX) {
260 expires->value.data = (u_char *) "Thu, 31 Dec 2037 23:55:55 GMT";
261 /* 10 years */
262 ngx_str_set(&cc->value, "max-age=315360000");
263 return NGX_OK;
264 }
265
266 expires->value.data = ngx_pnalloc(r->pool, len);
267 if (expires->value.data == NULL) {
268 return NGX_ERROR;
269 }
270
271 if (conf->expires_time == 0 && conf->expires != NGX_HTTP_EXPIRES_DAILY) {
272 ngx_memcpy(expires->value.data, ngx_cached_http_time.data,
273 ngx_cached_http_time.len + 1);
274 ngx_str_set(&cc->value, "max-age=0");
275 return NGX_OK;
276 }
277
278 now = ngx_time();
279
280 if (conf->expires == NGX_HTTP_EXPIRES_DAILY) {
281 expires_time = ngx_next_time(conf->expires_time);
282 max_age = expires_time - now;
283
284 } else if (conf->expires == NGX_HTTP_EXPIRES_ACCESS
285 || r->headers_out.last_modified_time == -1)
286 {
287 expires_time = now + conf->expires_time;
288 max_age = conf->expires_time;
289
290 } else {
291 expires_time = r->headers_out.last_modified_time + conf->expires_time;
292 max_age = expires_time - now;
293 }
294
295 ngx_http_time(expires->value.data, expires_time);
296
297 if (conf->expires_time < 0 || max_age < 0) {
298 ngx_str_set(&cc->value, "no-cache");
299 return NGX_OK;
300 }
301
302 cc->value.data = ngx_pnalloc(r->pool,
303 sizeof("max-age=") + NGX_TIME_T_LEN + 1);
304 if (cc->value.data == NULL) {
305 return NGX_ERROR;
306 }
307
308 cc->value.len = ngx_sprintf(cc->value.data, "max-age=%T", max_age)
309 - cc->value.data;
310
311 return NGX_OK;
312 }
313
314
315 static ngx_int_t
316 ngx_http_add_header(ngx_http_request_t *r, ngx_http_header_val_t *hv,
317 ngx_str_t *value)
318 {
319 ngx_table_elt_t *h;
320
321 if (value->len) {
322 h = ngx_list_push(&r->headers_out.headers);
323 if (h == NULL) {
324 return NGX_ERROR;
325 }
326
327 h->hash = 1;
328 h->key = hv->key;
329 h->value = *value;
330 }
331
332 return NGX_OK;
333 }
334
335
336 static ngx_int_t
337 ngx_http_add_cache_control(ngx_http_request_t *r, ngx_http_header_val_t *hv,
338 ngx_str_t *value)
339 {
340 ngx_table_elt_t *cc, **ccp;
341
342 ccp = r->headers_out.cache_control.elts;
343
344 if (ccp == NULL) {
345
346 if (ngx_array_init(&r->headers_out.cache_control, r->pool,
347 1, sizeof(ngx_table_elt_t *))
348 != NGX_OK)
349 {
350 return NGX_ERROR;
351 }
352 }
353
354 ccp = ngx_array_push(&r->headers_out.cache_control);
355 if (ccp == NULL) {
356 return NGX_ERROR;
357 }
358
359 cc = ngx_list_push(&r->headers_out.headers);
360 if (cc == NULL) {
361 return NGX_ERROR;
362 }
363
364 cc->hash = 1;
365 ngx_str_set(&cc->key, "Cache-Control");
366 cc->value = *value;
367
368 *ccp = cc;
369
370 return NGX_OK;
371 }
372
373
374 static ngx_int_t
375 ngx_http_set_last_modified(ngx_http_request_t *r, ngx_http_header_val_t *hv,
376 ngx_str_t *value)
377 {
378 if (ngx_http_set_response_header(r, hv, value) != NGX_OK) {
379 return NGX_ERROR;
380 }
381
382 r->headers_out.last_modified_time =
383 (value->len) ? ngx_http_parse_time(value->data, value->len) : -1;
384
385 return NGX_OK;
386 }
387
388
389 static ngx_int_t
390 ngx_http_set_response_header(ngx_http_request_t *r, ngx_http_header_val_t *hv,
391 ngx_str_t *value)
392 {
393 ngx_table_elt_t *h, **old;
394
395 old = (ngx_table_elt_t **) ((char *) &r->headers_out + hv->offset);
396
397 if (value->len == 0) {
398 if (*old) {
399 (*old)->hash = 0;
400 *old = NULL;
401 }
402
403 return NGX_OK;
404 }
405
406 if (*old) {
407 h = *old;
408
409 } else {
410 h = ngx_list_push(&r->headers_out.headers);
411 if (h == NULL) {
412 return NGX_ERROR;
413 }
414
415 *old = h;
416 }
417
418 h->hash = 1;
419 h->key = hv->key;
420 h->value = *value;
421
422 return NGX_OK;
423 }
424
425
426 static void *
427 ngx_http_headers_create_conf(ngx_conf_t *cf)
428 {
429 ngx_http_headers_conf_t *conf;
430
431 conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_headers_conf_t));
432 if (conf == NULL) {
433 return NULL;
434 }
435
436 /*
437 * set by ngx_pcalloc():
438 *
439 * conf->headers = NULL;
440 * conf->expires_time = 0;
441 */
442
443 conf->expires = NGX_HTTP_EXPIRES_UNSET;
444
445 return conf;
446 }
447
448
449 static char *
450 ngx_http_headers_merge_conf(ngx_conf_t *cf, void *parent, void *child)
451 {
452 ngx_http_headers_conf_t *prev = parent;
453 ngx_http_headers_conf_t *conf = child;
454
455 if (conf->expires == NGX_HTTP_EXPIRES_UNSET) {
456 conf->expires = prev->expires;
457 conf->expires_time = prev->expires_time;
458
459 if (conf->expires == NGX_HTTP_EXPIRES_UNSET) {
460 conf->expires = NGX_HTTP_EXPIRES_OFF;
461 }
462 }
463
464 if (conf->headers == NULL) {
465 conf->headers = prev->headers;
466 }
467
468 return NGX_CONF_OK;
469 }
470
471
472 static ngx_int_t
473 ngx_http_headers_filter_init(ngx_conf_t *cf)
474 {
475 ngx_http_next_header_filter = ngx_http_top_header_filter;
476 ngx_http_top_header_filter = ngx_http_headers_filter;
477
478 return NGX_OK;
479 }
480
481
482 static char *
483 ngx_http_headers_expires(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
484 {
485 ngx_http_headers_conf_t *hcf = conf;
486
487 ngx_uint_t minus, n;
488 ngx_str_t *value;
489
490 if (hcf->expires != NGX_HTTP_EXPIRES_UNSET) {
491 return "is duplicate";
492 }
493
494 value = cf->args->elts;
495
496 if (cf->args->nelts == 2) {
497
498 if (ngx_strcmp(value[1].data, "epoch") == 0) {
499 hcf->expires = NGX_HTTP_EXPIRES_EPOCH;
500 return NGX_CONF_OK;
501 }
502
503 if (ngx_strcmp(value[1].data, "max") == 0) {
504 hcf->expires = NGX_HTTP_EXPIRES_MAX;
505 return NGX_CONF_OK;
506 }
507
508 if (ngx_strcmp(value[1].data, "off") == 0) {
509 hcf->expires = NGX_HTTP_EXPIRES_OFF;
510 return NGX_CONF_OK;
511 }
512
513 hcf->expires = NGX_HTTP_EXPIRES_ACCESS;
514
515 n = 1;
516
517 } else { /* cf->args->nelts == 3 */
518
519 if (ngx_strcmp(value[1].data, "modified") != 0) {
520 return "invalid value";
521 }
522
523 hcf->expires = NGX_HTTP_EXPIRES_MODIFIED;
524
525 n = 2;
526 }
527
528 if (value[n].data[0] == '@') {
529 value[n].data++;
530 value[n].len--;
531 minus = 0;
532
533 if (hcf->expires == NGX_HTTP_EXPIRES_MODIFIED) {
534 return "daily time cannot be used with \"modified\" parameter";
535 }
536
537 hcf->expires = NGX_HTTP_EXPIRES_DAILY;
538
539 } else if (value[n].data[0] == '+') {
540 value[n].data++;
541 value[n].len--;
542 minus = 0;
543
544 } else if (value[n].data[0] == '-') {
545 value[n].data++;
546 value[n].len--;
547 minus = 1;
548
549 } else {
550 minus = 0;
551 }
552
553 hcf->expires_time = ngx_parse_time(&value[n], 1);
554
555 if (hcf->expires_time == (time_t) NGX_ERROR) {
556 return "invalid value";
557 }
558
559 if (hcf->expires == NGX_HTTP_EXPIRES_DAILY
560 && hcf->expires_time > 24 * 60 * 60)
561 {
562 return "daily time value must be less than 24 hours";
563 }
564
565 if (minus) {
566 hcf->expires_time = - hcf->expires_time;
567 }
568
569 return NGX_CONF_OK;
570 }
571
572
573 static char *
574 ngx_http_headers_add(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
575 {
576 ngx_http_headers_conf_t *hcf = conf;
577
578 ngx_str_t *value;
579 ngx_uint_t i;
580 ngx_http_header_val_t *hv;
581 ngx_http_set_header_t *set;
582 ngx_http_compile_complex_value_t ccv;
583
584 value = cf->args->elts;
585
586 if (hcf->headers == NULL) {
587 hcf->headers = ngx_array_create(cf->pool, 1,
588 sizeof(ngx_http_header_val_t));
589 if (hcf->headers == NULL) {
590 return NGX_CONF_ERROR;
591 }
592 }
593
594 hv = ngx_array_push(hcf->headers);
595 if (hv == NULL) {
596 return NGX_CONF_ERROR;
597 }
598
599 hv->key = value[1];
600 hv->handler = ngx_http_add_header;
601 hv->offset = 0;
602
603 set = ngx_http_set_headers;
604 for (i = 0; set[i].name.len; i++) {
605 if (ngx_strcasecmp(value[1].data, set[i].name.data) != 0) {
606 continue;
607 }
608
609 hv->offset = set[i].offset;
610 hv->handler = set[i].handler;
611
612 break;
613 }
614
615 if (value[2].len == 0) {
616 ngx_memzero(&hv->value, sizeof(ngx_http_complex_value_t));
617 return NGX_CONF_OK;
618 }
619
620 ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));
621
622 ccv.cf = cf;
623 ccv.value = &value[2];
624 ccv.complex_value = &hv->value;
625
626 if (ngx_http_compile_complex_value(&ccv) != NGX_OK) {
627 return NGX_CONF_ERROR;
628 }
629
630 return NGX_CONF_OK;
631 }
632
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