1
2 /*
3 * Copyright (C) Roman Arutyunyan
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 {
14 size_t size;
15 } ngx_http_slice_loc_conf_t;
16
17
18 typedef struct {
19 off_t start;
20 off_t end;
21 ngx_str_t range;
22 ngx_str_t etag;
23 unsigned last:1;
24 unsigned active:1;
25 ngx_http_request_t *sr;
26 } ngx_http_slice_ctx_t;
27
28
29 typedef struct {
30 off_t start;
31 off_t end;
32 off_t complete_length;
33 } ngx_http_slice_content_range_t;
34
35
36 static ngx_int_t ngx_http_slice_header_filter(ngx_http_request_t *r);
37 static ngx_int_t ngx_http_slice_body_filter(ngx_http_request_t *r,
38 ngx_chain_t *in);
39 static ngx_int_t ngx_http_slice_parse_content_range(ngx_http_request_t *r,
40 ngx_http_slice_content_range_t *cr);
41 static ngx_int_t ngx_http_slice_range_variable(ngx_http_request_t *r,
42 ngx_http_variable_value_t *v, uintptr_t data);
43 static off_t ngx_http_slice_get_start(ngx_http_request_t *r);
44 static void *ngx_http_slice_create_loc_conf(ngx_conf_t *cf);
45 static char *ngx_http_slice_merge_loc_conf(ngx_conf_t *cf, void *parent,
46 void *child);
47 static ngx_int_t ngx_http_slice_add_variables(ngx_conf_t *cf);
48 static ngx_int_t ngx_http_slice_init(ngx_conf_t *cf);
49
50
51 static ngx_command_t ngx_http_slice_filter_commands[] = {
52
53 { ngx_string("slice"),
54 NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
55 ngx_conf_set_size_slot,
56 NGX_HTTP_LOC_CONF_OFFSET,
57 offsetof(ngx_http_slice_loc_conf_t, size),
58 NULL },
59
60 ngx_null_command
61 };
62
63
64 static ngx_http_module_t ngx_http_slice_filter_module_ctx = {
65 ngx_http_slice_add_variables, /* preconfiguration */
66 ngx_http_slice_init, /* postconfiguration */
67
68 NULL, /* create main configuration */
69 NULL, /* init main configuration */
70
71 NULL, /* create server configuration */
72 NULL, /* merge server configuration */
73
74 ngx_http_slice_create_loc_conf, /* create location configuration */
75 ngx_http_slice_merge_loc_conf /* merge location configuration */
76 };
77
78
79 ngx_module_t ngx_http_slice_filter_module = {
80 NGX_MODULE_V1,
81 &ngx_http_slice_filter_module_ctx, /* module context */
82 ngx_http_slice_filter_commands, /* module directives */
83 NGX_HTTP_MODULE, /* module type */
84 NULL, /* init master */
85 NULL, /* init module */
86 NULL, /* init process */
87 NULL, /* init thread */
88 NULL, /* exit thread */
89 NULL, /* exit process */
90 NULL, /* exit master */
91 NGX_MODULE_V1_PADDING
92 };
93
94
95 static ngx_str_t ngx_http_slice_range_name = ngx_string("slice_range");
96
97 static ngx_http_output_header_filter_pt ngx_http_next_header_filter;
98 static ngx_http_output_body_filter_pt ngx_http_next_body_filter;
99
100
101 static ngx_int_t
ngx_http_slice_header_filter(ngx_http_request_t * r)102 ngx_http_slice_header_filter(ngx_http_request_t *r)
103 {
104 off_t end;
105 ngx_int_t rc;
106 ngx_table_elt_t *h;
107 ngx_http_slice_ctx_t *ctx;
108 ngx_http_slice_loc_conf_t *slcf;
109 ngx_http_slice_content_range_t cr;
110
111 ctx = ngx_http_get_module_ctx(r, ngx_http_slice_filter_module);
112 if (ctx == NULL) {
113 return ngx_http_next_header_filter(r);
114 }
115
116 if (r->headers_out.status != NGX_HTTP_PARTIAL_CONTENT) {
117 if (r == r->main) {
118 ngx_http_set_ctx(r, NULL, ngx_http_slice_filter_module);
119 return ngx_http_next_header_filter(r);
120 }
121
122 ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
123 "unexpected status code %ui in slice response",
124 r->headers_out.status);
125 return NGX_ERROR;
126 }
127
128 h = r->headers_out.etag;
129
130 if (ctx->etag.len) {
131 if (h == NULL
132 || h->value.len != ctx->etag.len
133 || ngx_strncmp(h->value.data, ctx->etag.data, ctx->etag.len)
134 != 0)
135 {
136 ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
137 "etag mismatch in slice response");
138 return NGX_ERROR;
139 }
140 }
141
142 if (h) {
143 ctx->etag = h->value;
144 }
145
146 if (ngx_http_slice_parse_content_range(r, &cr) != NGX_OK) {
147 ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
148 "invalid range in slice response");
149 return NGX_ERROR;
150 }
151
152 if (cr.complete_length == -1) {
153 ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
154 "no complete length in slice response");
155 return NGX_ERROR;
156 }
157
158 ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
159 "http slice response range: %O-%O/%O",
160 cr.start, cr.end, cr.complete_length);
161
162 slcf = ngx_http_get_module_loc_conf(r, ngx_http_slice_filter_module);
163
164 end = ngx_min(cr.start + (off_t) slcf->size, cr.complete_length);
165
166 if (cr.start != ctx->start || cr.end != end) {
167 ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
168 "unexpected range in slice response: %O-%O",
169 cr.start, cr.end);
170 return NGX_ERROR;
171 }
172
173 ctx->start = end;
174 ctx->active = 1;
175
176 r->headers_out.status = NGX_HTTP_OK;
177 r->headers_out.status_line.len = 0;
178 r->headers_out.content_length_n = cr.complete_length;
179 r->headers_out.content_offset = cr.start;
180 r->headers_out.content_range->hash = 0;
181 r->headers_out.content_range = NULL;
182
183 if (r->headers_out.accept_ranges) {
184 r->headers_out.accept_ranges->hash = 0;
185 r->headers_out.accept_ranges = NULL;
186 }
187
188 r->allow_ranges = 1;
189 r->subrequest_ranges = 1;
190 r->single_range = 1;
191
192 rc = ngx_http_next_header_filter(r);
193
194 if (r != r->main) {
195 return rc;
196 }
197
198 r->preserve_body = 1;
199
200 if (r->headers_out.status == NGX_HTTP_PARTIAL_CONTENT) {
201 if (ctx->start + (off_t) slcf->size <= r->headers_out.content_offset) {
202 ctx->start = slcf->size
203 * (r->headers_out.content_offset / slcf->size);
204 }
205
206 ctx->end = r->headers_out.content_offset
207 + r->headers_out.content_length_n;
208
209 } else {
210 ctx->end = cr.complete_length;
211 }
212
213 return rc;
214 }
215
216
217 static ngx_int_t
ngx_http_slice_body_filter(ngx_http_request_t * r,ngx_chain_t * in)218 ngx_http_slice_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
219 {
220 ngx_int_t rc;
221 ngx_chain_t *cl;
222 ngx_http_slice_ctx_t *ctx;
223 ngx_http_slice_loc_conf_t *slcf;
224
225 ctx = ngx_http_get_module_ctx(r, ngx_http_slice_filter_module);
226
227 if (ctx == NULL || r != r->main) {
228 return ngx_http_next_body_filter(r, in);
229 }
230
231 for (cl = in; cl; cl = cl->next) {
232 if (cl->buf->last_buf) {
233 cl->buf->last_buf = 0;
234 cl->buf->last_in_chain = 1;
235 cl->buf->sync = 1;
236 ctx->last = 1;
237 }
238 }
239
240 rc = ngx_http_next_body_filter(r, in);
241
242 if (rc == NGX_ERROR || !ctx->last) {
243 return rc;
244 }
245
246 if (ctx->sr && !ctx->sr->done) {
247 return rc;
248 }
249
250 if (!ctx->active) {
251 ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
252 "missing slice response");
253 return NGX_ERROR;
254 }
255
256 if (ctx->start >= ctx->end) {
257 ngx_http_set_ctx(r, NULL, ngx_http_slice_filter_module);
258 ngx_http_send_special(r, NGX_HTTP_LAST);
259 return rc;
260 }
261
262 if (r->buffered) {
263 return rc;
264 }
265
266 if (ngx_http_subrequest(r, &r->uri, &r->args, &ctx->sr, NULL,
267 NGX_HTTP_SUBREQUEST_CLONE)
268 != NGX_OK)
269 {
270 return NGX_ERROR;
271 }
272
273 ngx_http_set_ctx(ctx->sr, ctx, ngx_http_slice_filter_module);
274
275 slcf = ngx_http_get_module_loc_conf(r, ngx_http_slice_filter_module);
276
277 ctx->range.len = ngx_sprintf(ctx->range.data, "bytes=%O-%O", ctx->start,
278 ctx->start + (off_t) slcf->size - 1)
279 - ctx->range.data;
280
281 ctx->active = 0;
282
283 ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
284 "http slice subrequest: \"%V\"", &ctx->range);
285
286 return rc;
287 }
288
289
290 static ngx_int_t
ngx_http_slice_parse_content_range(ngx_http_request_t * r,ngx_http_slice_content_range_t * cr)291 ngx_http_slice_parse_content_range(ngx_http_request_t *r,
292 ngx_http_slice_content_range_t *cr)
293 {
294 off_t start, end, complete_length, cutoff, cutlim;
295 u_char *p;
296 ngx_table_elt_t *h;
297
298 h = r->headers_out.content_range;
299
300 if (h == NULL
301 || h->value.len < 7
302 || ngx_strncmp(h->value.data, "bytes ", 6) != 0)
303 {
304 return NGX_ERROR;
305 }
306
307 p = h->value.data + 6;
308
309 cutoff = NGX_MAX_OFF_T_VALUE / 10;
310 cutlim = NGX_MAX_OFF_T_VALUE % 10;
311
312 start = 0;
313 end = 0;
314 complete_length = 0;
315
316 while (*p == ' ') { p++; }
317
318 if (*p < '0' || *p > '9') {
319 return NGX_ERROR;
320 }
321
322 while (*p >= '0' && *p <= '9') {
323 if (start >= cutoff && (start > cutoff || *p - '0' > cutlim)) {
324 return NGX_ERROR;
325 }
326
327 start = start * 10 + (*p++ - '0');
328 }
329
330 while (*p == ' ') { p++; }
331
332 if (*p++ != '-') {
333 return NGX_ERROR;
334 }
335
336 while (*p == ' ') { p++; }
337
338 if (*p < '0' || *p > '9') {
339 return NGX_ERROR;
340 }
341
342 while (*p >= '0' && *p <= '9') {
343 if (end >= cutoff && (end > cutoff || *p - '0' > cutlim)) {
344 return NGX_ERROR;
345 }
346
347 end = end * 10 + (*p++ - '0');
348 }
349
350 end++;
351
352 while (*p == ' ') { p++; }
353
354 if (*p++ != '/') {
355 return NGX_ERROR;
356 }
357
358 while (*p == ' ') { p++; }
359
360 if (*p != '*') {
361 if (*p < '0' || *p > '9') {
362 return NGX_ERROR;
363 }
364
365 while (*p >= '0' && *p <= '9') {
366 if (complete_length >= cutoff
367 && (complete_length > cutoff || *p - '0' > cutlim))
368 {
369 return NGX_ERROR;
370 }
371
372 complete_length = complete_length * 10 + (*p++ - '0');
373 }
374
375 } else {
376 complete_length = -1;
377 p++;
378 }
379
380 while (*p == ' ') { p++; }
381
382 if (*p != '\0') {
383 return NGX_ERROR;
384 }
385
386 cr->start = start;
387 cr->end = end;
388 cr->complete_length = complete_length;
389
390 return NGX_OK;
391 }
392
393
394 static ngx_int_t
ngx_http_slice_range_variable(ngx_http_request_t * r,ngx_http_variable_value_t * v,uintptr_t data)395 ngx_http_slice_range_variable(ngx_http_request_t *r,
396 ngx_http_variable_value_t *v, uintptr_t data)
397 {
398 u_char *p;
399 ngx_http_slice_ctx_t *ctx;
400 ngx_http_slice_loc_conf_t *slcf;
401
402 ctx = ngx_http_get_module_ctx(r, ngx_http_slice_filter_module);
403
404 if (ctx == NULL) {
405 if (r != r->main || r->headers_out.status) {
406 v->not_found = 1;
407 return NGX_OK;
408 }
409
410 slcf = ngx_http_get_module_loc_conf(r, ngx_http_slice_filter_module);
411
412 if (slcf->size == 0) {
413 v->not_found = 1;
414 return NGX_OK;
415 }
416
417 ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_slice_ctx_t));
418 if (ctx == NULL) {
419 return NGX_ERROR;
420 }
421
422 ngx_http_set_ctx(r, ctx, ngx_http_slice_filter_module);
423
424 p = ngx_pnalloc(r->pool, sizeof("bytes=-") - 1 + 2 * NGX_OFF_T_LEN);
425 if (p == NULL) {
426 return NGX_ERROR;
427 }
428
429 ctx->start = slcf->size * (ngx_http_slice_get_start(r) / slcf->size);
430
431 ctx->range.data = p;
432 ctx->range.len = ngx_sprintf(p, "bytes=%O-%O", ctx->start,
433 ctx->start + (off_t) slcf->size - 1)
434 - p;
435 }
436
437 v->data = ctx->range.data;
438 v->valid = 1;
439 v->not_found = 0;
440 v->no_cacheable = 1;
441 v->len = ctx->range.len;
442
443 return NGX_OK;
444 }
445
446
447 static off_t
ngx_http_slice_get_start(ngx_http_request_t * r)448 ngx_http_slice_get_start(ngx_http_request_t *r)
449 {
450 off_t start, cutoff, cutlim;
451 u_char *p;
452 ngx_table_elt_t *h;
453
454 if (r->headers_in.if_range) {
455 return 0;
456 }
457
458 h = r->headers_in.range;
459
460 if (h == NULL
461 || h->value.len < 7
462 || ngx_strncasecmp(h->value.data, (u_char *) "bytes=", 6) != 0)
463 {
464 return 0;
465 }
466
467 p = h->value.data + 6;
468
469 if (ngx_strchr(p, ',')) {
470 return 0;
471 }
472
473 while (*p == ' ') { p++; }
474
475 if (*p == '-') {
476 return 0;
477 }
478
479 cutoff = NGX_MAX_OFF_T_VALUE / 10;
480 cutlim = NGX_MAX_OFF_T_VALUE % 10;
481
482 start = 0;
483
484 while (*p >= '0' && *p <= '9') {
485 if (start >= cutoff && (start > cutoff || *p - '0' > cutlim)) {
486 return 0;
487 }
488
489 start = start * 10 + (*p++ - '0');
490 }
491
492 return start;
493 }
494
495
496 static void *
ngx_http_slice_create_loc_conf(ngx_conf_t * cf)497 ngx_http_slice_create_loc_conf(ngx_conf_t *cf)
498 {
499 ngx_http_slice_loc_conf_t *slcf;
500
501 slcf = ngx_palloc(cf->pool, sizeof(ngx_http_slice_loc_conf_t));
502 if (slcf == NULL) {
503 return NULL;
504 }
505
506 slcf->size = NGX_CONF_UNSET_SIZE;
507
508 return slcf;
509 }
510
511
512 static char *
ngx_http_slice_merge_loc_conf(ngx_conf_t * cf,void * parent,void * child)513 ngx_http_slice_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
514 {
515 ngx_http_slice_loc_conf_t *prev = parent;
516 ngx_http_slice_loc_conf_t *conf = child;
517
518 ngx_conf_merge_size_value(conf->size, prev->size, 0);
519
520 return NGX_CONF_OK;
521 }
522
523
524 static ngx_int_t
ngx_http_slice_add_variables(ngx_conf_t * cf)525 ngx_http_slice_add_variables(ngx_conf_t *cf)
526 {
527 ngx_http_variable_t *var;
528
529 var = ngx_http_add_variable(cf, &ngx_http_slice_range_name, 0);
530 if (var == NULL) {
531 return NGX_ERROR;
532 }
533
534 var->get_handler = ngx_http_slice_range_variable;
535
536 return NGX_OK;
537 }
538
539
540 static ngx_int_t
ngx_http_slice_init(ngx_conf_t * cf)541 ngx_http_slice_init(ngx_conf_t *cf)
542 {
543 ngx_http_next_header_filter = ngx_http_top_header_filter;
544 ngx_http_top_header_filter = ngx_http_slice_header_filter;
545
546 ngx_http_next_body_filter = ngx_http_top_body_filter;
547 ngx_http_top_body_filter = ngx_http_slice_body_filter;
548
549 return NGX_OK;
550 }
551