1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23#include "curl_setup.h"
24
25#include "urldata.h"
26#include <curl/curl.h>
27#include <stddef.h>
28
29#ifdef HAVE_ZLIB_H
30#include <zlib.h>
31#endif
32
33#ifdef HAVE_BROTLI
34#include <brotli/decode.h>
35#endif
36
37#ifdef HAVE_ZSTD
38#include <zstd.h>
39#endif
40
41#include "sendf.h"
42#include "http.h"
43#include "content_encoding.h"
44#include "strdup.h"
45#include "strcase.h"
46#include "curl_memory.h"
47#include "memdebug.h"
48
49#define CONTENT_ENCODING_DEFAULT "identity"
50
51#ifndef CURL_DISABLE_HTTP
52
53#define DSIZ CURL_MAX_WRITE_SIZE /* buffer size for decompressed data */
54
55
56#ifdef HAVE_LIBZ
57
58/* Comment this out if zlib is always going to be at least ver. 1.2.0.4
59 (doing so will reduce code size slightly). */
60#define OLD_ZLIB_SUPPORT 1
61
62#define GZIP_MAGIC_0 0x1f
63#define GZIP_MAGIC_1 0x8b
64
65/* gzip flag byte */
66#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
67#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */
68#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
69#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
70#define COMMENT 0x10 /* bit 4 set: file comment present */
71#define RESERVED 0xE0 /* bits 5..7: reserved */
72
73typedef enum {
74 ZLIB_UNINIT, /* uninitialized */
75 ZLIB_INIT, /* initialized */
76 ZLIB_INFLATING, /* inflating started. */
77 ZLIB_EXTERNAL_TRAILER, /* reading external trailer */
78 ZLIB_GZIP_HEADER, /* reading gzip header */
79 ZLIB_GZIP_INFLATING, /* inflating gzip stream */
80 ZLIB_INIT_GZIP /* initialized in transparent gzip mode */
81} zlibInitState;
82
83/* Writer parameters. */
84struct zlib_params {
85 zlibInitState zlib_init; /* zlib init state */
86 uInt trailerlen; /* Remaining trailer byte count. */
87 z_stream z; /* State structure for zlib. */
88};
89
90
91static voidpf
92zalloc_cb(voidpf opaque, unsigned int items, unsigned int size)
93{
94 (void) opaque;
95 /* not a typo, keep it calloc() */
96 return (voidpf) calloc(items, size);
97}
98
99static void
100zfree_cb(voidpf opaque, voidpf ptr)
101{
102 (void) opaque;
103 free(ptr);
104}
105
106static CURLcode
107process_zlib_error(struct Curl_easy *data, z_stream *z)
108{
109 if(z->msg)
110 failf(data, "Error while processing content unencoding: %s",
111 z->msg);
112 else
113 failf(data, "Error while processing content unencoding: "
114 "Unknown failure within decompression software.");
115
116 return CURLE_BAD_CONTENT_ENCODING;
117}
118
119static CURLcode
120exit_zlib(struct Curl_easy *data,
121 z_stream *z, zlibInitState *zlib_init, CURLcode result)
122{
123 if(*zlib_init == ZLIB_GZIP_HEADER)
124 Curl_safefree(z->next_in);
125
126 if(*zlib_init != ZLIB_UNINIT) {
127 if(inflateEnd(z) != Z_OK && result == CURLE_OK)
128 result = process_zlib_error(data, z);
129 *zlib_init = ZLIB_UNINIT;
130 }
131
132 return result;
133}
134
135static CURLcode process_trailer(struct Curl_easy *data,
136 struct zlib_params *zp)
137{
138 z_stream *z = &zp->z;
139 CURLcode result = CURLE_OK;
140 uInt len = z->avail_in < zp->trailerlen? z->avail_in: zp->trailerlen;
141
142 /* Consume expected trailer bytes. Terminate stream if exhausted.
143 Issue an error if unexpected bytes follow. */
144
145 zp->trailerlen -= len;
146 z->avail_in -= len;
147 z->next_in += len;
148 if(z->avail_in)
149 result = CURLE_WRITE_ERROR;
150 if(result || !zp->trailerlen)
151 result = exit_zlib(data, z, &zp->zlib_init, result);
152 else {
153 /* Only occurs for gzip with zlib < 1.2.0.4 or raw deflate. */
154 zp->zlib_init = ZLIB_EXTERNAL_TRAILER;
155 }
156 return result;
157}
158
159static CURLcode inflate_stream(struct Curl_easy *data,
160 struct contenc_writer *writer,
161 zlibInitState started)
162{
163 struct zlib_params *zp = (struct zlib_params *) &writer->params;
164 z_stream *z = &zp->z; /* zlib state structure */
165 uInt nread = z->avail_in;
166 Bytef *orig_in = z->next_in;
167 bool done = FALSE;
168 CURLcode result = CURLE_OK; /* Curl_client_write status */
169 char *decomp; /* Put the decompressed data here. */
170
171 /* Check state. */
172 if(zp->zlib_init != ZLIB_INIT &&
173 zp->zlib_init != ZLIB_INFLATING &&
174 zp->zlib_init != ZLIB_INIT_GZIP &&
175 zp->zlib_init != ZLIB_GZIP_INFLATING)
176 return exit_zlib(data, z, &zp->zlib_init, CURLE_WRITE_ERROR);
177
178 /* Dynamically allocate a buffer for decompression because it's uncommonly
179 large to hold on the stack */
180 decomp = malloc(DSIZ);
181 if(!decomp)
182 return exit_zlib(data, z, &zp->zlib_init, CURLE_OUT_OF_MEMORY);
183
184 /* because the buffer size is fixed, iteratively decompress and transfer to
185 the client via downstream_write function. */
186 while(!done) {
187 int status; /* zlib status */
188 done = TRUE;
189
190 /* (re)set buffer for decompressed output for every iteration */
191 z->next_out = (Bytef *) decomp;
192 z->avail_out = DSIZ;
193
194#ifdef Z_BLOCK
195 /* Z_BLOCK is only available in zlib ver. >= 1.2.0.5 */
196 status = inflate(z, Z_BLOCK);
197#else
198 /* fallback for zlib ver. < 1.2.0.5 */
199 status = inflate(z, Z_SYNC_FLUSH);
200#endif
201
202 /* Flush output data if some. */
203 if(z->avail_out != DSIZ) {
204 if(status == Z_OK || status == Z_STREAM_END) {
205 zp->zlib_init = started; /* Data started. */
206 result = Curl_unencode_write(data, writer->downstream, decomp,
207 DSIZ - z->avail_out);
208 if(result) {
209 exit_zlib(data, z, &zp->zlib_init, result);
210 break;
211 }
212 }
213 }
214
215 /* Dispatch by inflate() status. */
216 switch(status) {
217 case Z_OK:
218 /* Always loop: there may be unflushed latched data in zlib state. */
219 done = FALSE;
220 break;
221 case Z_BUF_ERROR:
222 /* No more data to flush: just exit loop. */
223 break;
224 case Z_STREAM_END:
225 result = process_trailer(data, zp);
226 break;
227 case Z_DATA_ERROR:
228 /* some servers seem to not generate zlib headers, so this is an attempt
229 to fix and continue anyway */
230 if(zp->zlib_init == ZLIB_INIT) {
231 /* Do not use inflateReset2(): only available since zlib 1.2.3.4. */
232 (void) inflateEnd(z); /* don't care about the return code */
233 if(inflateInit2(z, -MAX_WBITS) == Z_OK) {
234 z->next_in = orig_in;
235 z->avail_in = nread;
236 zp->zlib_init = ZLIB_INFLATING;
237 zp->trailerlen = 4; /* Tolerate up to 4 unknown trailer bytes. */
238 done = FALSE;
239 break;
240 }
241 zp->zlib_init = ZLIB_UNINIT; /* inflateEnd() already called. */
242 }
243 /* FALLTHROUGH */
244 default:
245 result = exit_zlib(data, z, &zp->zlib_init, process_zlib_error(data, z));
246 break;
247 }
248 }
249 free(decomp);
250
251 /* We're about to leave this call so the `nread' data bytes won't be seen
252 again. If we are in a state that would wrongly allow restart in raw mode
253 at the next call, assume output has already started. */
254 if(nread && zp->zlib_init == ZLIB_INIT)
255 zp->zlib_init = started; /* Cannot restart anymore. */
256
257 return result;
258}
259
260
261/* Deflate handler. */
262static CURLcode deflate_init_writer(struct Curl_easy *data,
263 struct contenc_writer *writer)
264{
265 struct zlib_params *zp = (struct zlib_params *) &writer->params;
266 z_stream *z = &zp->z; /* zlib state structure */
267
268 if(!writer->downstream)
269 return CURLE_WRITE_ERROR;
270
271 /* Initialize zlib */
272 z->zalloc = (alloc_func) zalloc_cb;
273 z->zfree = (free_func) zfree_cb;
274
275 if(inflateInit(z) != Z_OK)
276 return process_zlib_error(data, z);
277 zp->zlib_init = ZLIB_INIT;
278 return CURLE_OK;
279}
280
281static CURLcode deflate_unencode_write(struct Curl_easy *data,
282 struct contenc_writer *writer,
283 const char *buf, size_t nbytes)
284{
285 struct zlib_params *zp = (struct zlib_params *) &writer->params;
286 z_stream *z = &zp->z; /* zlib state structure */
287
288 /* Set the compressed input when this function is called */
289 z->next_in = (Bytef *) buf;
290 z->avail_in = (uInt) nbytes;
291
292 if(zp->zlib_init == ZLIB_EXTERNAL_TRAILER)
293 return process_trailer(data, zp);
294
295 /* Now uncompress the data */
296 return inflate_stream(data, writer, ZLIB_INFLATING);
297}
298
299static void deflate_close_writer(struct Curl_easy *data,
300 struct contenc_writer *writer)
301{
302 struct zlib_params *zp = (struct zlib_params *) &writer->params;
303 z_stream *z = &zp->z; /* zlib state structure */
304
305 exit_zlib(data, z, &zp->zlib_init, CURLE_OK);
306}
307
308static const struct content_encoding deflate_encoding = {
309 "deflate",
310 NULL,
311 deflate_init_writer,
312 deflate_unencode_write,
313 deflate_close_writer,
314 sizeof(struct zlib_params)
315};
316
317
318/* Gzip handler. */
319static CURLcode gzip_init_writer(struct Curl_easy *data,
320 struct contenc_writer *writer)
321{
322 struct zlib_params *zp = (struct zlib_params *) &writer->params;
323 z_stream *z = &zp->z; /* zlib state structure */
324
325 if(!writer->downstream)
326 return CURLE_WRITE_ERROR;
327
328 /* Initialize zlib */
329 z->zalloc = (alloc_func) zalloc_cb;
330 z->zfree = (free_func) zfree_cb;
331
332 if(strcmp(zlibVersion(), "1.2.0.4") >= 0) {
333 /* zlib ver. >= 1.2.0.4 supports transparent gzip decompressing */
334 if(inflateInit2(z, MAX_WBITS + 32) != Z_OK) {
335 return process_zlib_error(data, z);
336 }
337 zp->zlib_init = ZLIB_INIT_GZIP; /* Transparent gzip decompress state */
338 }
339 else {
340 /* we must parse the gzip header and trailer ourselves */
341 if(inflateInit2(z, -MAX_WBITS) != Z_OK) {
342 return process_zlib_error(data, z);
343 }
344 zp->trailerlen = 8; /* A CRC-32 and a 32-bit input size (RFC 1952, 2.2) */
345 zp->zlib_init = ZLIB_INIT; /* Initial call state */
346 }
347
348 return CURLE_OK;
349}
350
351#ifdef OLD_ZLIB_SUPPORT
352/* Skip over the gzip header */
353static enum {
354 GZIP_OK,
355 GZIP_BAD,
356 GZIP_UNDERFLOW
357} check_gzip_header(unsigned char const *data, ssize_t len, ssize_t *headerlen)
358{
359 int method, flags;
360 const ssize_t totallen = len;
361
362 /* The shortest header is 10 bytes */
363 if(len < 10)
364 return GZIP_UNDERFLOW;
365
366 if((data[0] != GZIP_MAGIC_0) || (data[1] != GZIP_MAGIC_1))
367 return GZIP_BAD;
368
369 method = data[2];
370 flags = data[3];
371
372 if(method != Z_DEFLATED || (flags & RESERVED) != 0) {
373 /* Can't handle this compression method or unknown flag */
374 return GZIP_BAD;
375 }
376
377 /* Skip over time, xflags, OS code and all previous bytes */
378 len -= 10;
379 data += 10;
380
381 if(flags & EXTRA_FIELD) {
382 ssize_t extra_len;
383
384 if(len < 2)
385 return GZIP_UNDERFLOW;
386
387 extra_len = (data[1] << 8) | data[0];
388
389 if(len < (extra_len + 2))
390 return GZIP_UNDERFLOW;
391
392 len -= (extra_len + 2);
393 data += (extra_len + 2);
394 }
395
396 if(flags & ORIG_NAME) {
397 /* Skip over NUL-terminated file name */
398 while(len && *data) {
399 --len;
400 ++data;
401 }
402 if(!len || *data)
403 return GZIP_UNDERFLOW;
404
405 /* Skip over the NUL */
406 --len;
407 ++data;
408 }
409
410 if(flags & COMMENT) {
411 /* Skip over NUL-terminated comment */
412 while(len && *data) {
413 --len;
414 ++data;
415 }
416 if(!len || *data)
417 return GZIP_UNDERFLOW;
418
419 /* Skip over the NUL */
420 --len;
421 }
422
423 if(flags & HEAD_CRC) {
424 if(len < 2)
425 return GZIP_UNDERFLOW;
426
427 len -= 2;
428 }
429
430 *headerlen = totallen - len;
431 return GZIP_OK;
432}
433#endif
434
435static CURLcode gzip_unencode_write(struct Curl_easy *data,
436 struct contenc_writer *writer,
437 const char *buf, size_t nbytes)
438{
439 struct zlib_params *zp = (struct zlib_params *) &writer->params;
440 z_stream *z = &zp->z; /* zlib state structure */
441
442 if(zp->zlib_init == ZLIB_INIT_GZIP) {
443 /* Let zlib handle the gzip decompression entirely */
444 z->next_in = (Bytef *) buf;
445 z->avail_in = (uInt) nbytes;
446 /* Now uncompress the data */
447 return inflate_stream(data, writer, ZLIB_INIT_GZIP);
448 }
449
450#ifndef OLD_ZLIB_SUPPORT
451 /* Support for old zlib versions is compiled away and we are running with
452 an old version, so return an error. */
453 return exit_zlib(data, z, &zp->zlib_init, CURLE_WRITE_ERROR);
454
455#else
456 /* This next mess is to get around the potential case where there isn't
457 * enough data passed in to skip over the gzip header. If that happens, we
458 * malloc a block and copy what we have then wait for the next call. If
459 * there still isn't enough (this is definitely a worst-case scenario), we
460 * make the block bigger, copy the next part in and keep waiting.
461 *
462 * This is only required with zlib versions < 1.2.0.4 as newer versions
463 * can handle the gzip header themselves.
464 */
465
466 switch(zp->zlib_init) {
467 /* Skip over gzip header? */
468 case ZLIB_INIT:
469 {
470 /* Initial call state */
471 ssize_t hlen;
472
473 switch(check_gzip_header((unsigned char *) buf, nbytes, &hlen)) {
474 case GZIP_OK:
475 z->next_in = (Bytef *) buf + hlen;
476 z->avail_in = (uInt) (nbytes - hlen);
477 zp->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */
478 break;
479
480 case GZIP_UNDERFLOW:
481 /* We need more data so we can find the end of the gzip header. It's
482 * possible that the memory block we malloc here will never be freed if
483 * the transfer abruptly aborts after this point. Since it's unlikely
484 * that circumstances will be right for this code path to be followed in
485 * the first place, and it's even more unlikely for a transfer to fail
486 * immediately afterwards, it should seldom be a problem.
487 */
488 z->avail_in = (uInt) nbytes;
489 z->next_in = malloc(z->avail_in);
490 if(!z->next_in) {
491 return exit_zlib(data, z, &zp->zlib_init, CURLE_OUT_OF_MEMORY);
492 }
493 memcpy(z->next_in, buf, z->avail_in);
494 zp->zlib_init = ZLIB_GZIP_HEADER; /* Need more gzip header data state */
495 /* We don't have any data to inflate yet */
496 return CURLE_OK;
497
498 case GZIP_BAD:
499 default:
500 return exit_zlib(data, z, &zp->zlib_init, process_zlib_error(data, z));
501 }
502
503 }
504 break;
505
506 case ZLIB_GZIP_HEADER:
507 {
508 /* Need more gzip header data state */
509 ssize_t hlen;
510 z->avail_in += (uInt) nbytes;
511 z->next_in = Curl_saferealloc(z->next_in, z->avail_in);
512 if(!z->next_in) {
513 return exit_zlib(data, z, &zp->zlib_init, CURLE_OUT_OF_MEMORY);
514 }
515 /* Append the new block of data to the previous one */
516 memcpy(z->next_in + z->avail_in - nbytes, buf, nbytes);
517
518 switch(check_gzip_header(z->next_in, z->avail_in, &hlen)) {
519 case GZIP_OK:
520 /* This is the zlib stream data */
521 free(z->next_in);
522 /* Don't point into the malloced block since we just freed it */
523 z->next_in = (Bytef *) buf + hlen + nbytes - z->avail_in;
524 z->avail_in = (uInt) (z->avail_in - hlen);
525 zp->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */
526 break;
527
528 case GZIP_UNDERFLOW:
529 /* We still don't have any data to inflate! */
530 return CURLE_OK;
531
532 case GZIP_BAD:
533 default:
534 return exit_zlib(data, z, &zp->zlib_init, process_zlib_error(data, z));
535 }
536
537 }
538 break;
539
540 case ZLIB_EXTERNAL_TRAILER:
541 z->next_in = (Bytef *) buf;
542 z->avail_in = (uInt) nbytes;
543 return process_trailer(data, zp);
544
545 case ZLIB_GZIP_INFLATING:
546 default:
547 /* Inflating stream state */
548 z->next_in = (Bytef *) buf;
549 z->avail_in = (uInt) nbytes;
550 break;
551 }
552
553 if(z->avail_in == 0) {
554 /* We don't have any data to inflate; wait until next time */
555 return CURLE_OK;
556 }
557
558 /* We've parsed the header, now uncompress the data */
559 return inflate_stream(data, writer, ZLIB_GZIP_INFLATING);
560#endif
561}
562
563static void gzip_close_writer(struct Curl_easy *data,
564 struct contenc_writer *writer)
565{
566 struct zlib_params *zp = (struct zlib_params *) &writer->params;
567 z_stream *z = &zp->z; /* zlib state structure */
568
569 exit_zlib(data, z, &zp->zlib_init, CURLE_OK);
570}
571
572static const struct content_encoding gzip_encoding = {
573 "gzip",
574 "x-gzip",
575 gzip_init_writer,
576 gzip_unencode_write,
577 gzip_close_writer,
578 sizeof(struct zlib_params)
579};
580
581#endif /* HAVE_LIBZ */
582
583
584#ifdef HAVE_BROTLI
585/* Writer parameters. */
586struct brotli_params {
587 BrotliDecoderState *br; /* State structure for brotli. */
588};
589
590static CURLcode brotli_map_error(BrotliDecoderErrorCode be)
591{
592 switch(be) {
593 case BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_NIBBLE:
594 case BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_META_NIBBLE:
595 case BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_ALPHABET:
596 case BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_SAME:
597 case BROTLI_DECODER_ERROR_FORMAT_CL_SPACE:
598 case BROTLI_DECODER_ERROR_FORMAT_HUFFMAN_SPACE:
599 case BROTLI_DECODER_ERROR_FORMAT_CONTEXT_MAP_REPEAT:
600 case BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_1:
601 case BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_2:
602 case BROTLI_DECODER_ERROR_FORMAT_TRANSFORM:
603 case BROTLI_DECODER_ERROR_FORMAT_DICTIONARY:
604 case BROTLI_DECODER_ERROR_FORMAT_WINDOW_BITS:
605 case BROTLI_DECODER_ERROR_FORMAT_PADDING_1:
606 case BROTLI_DECODER_ERROR_FORMAT_PADDING_2:
607#ifdef BROTLI_DECODER_ERROR_COMPOUND_DICTIONARY
608 case BROTLI_DECODER_ERROR_COMPOUND_DICTIONARY:
609#endif
610#ifdef BROTLI_DECODER_ERROR_DICTIONARY_NOT_SET
611 case BROTLI_DECODER_ERROR_DICTIONARY_NOT_SET:
612#endif
613 case BROTLI_DECODER_ERROR_INVALID_ARGUMENTS:
614 return CURLE_BAD_CONTENT_ENCODING;
615 case BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MODES:
616 case BROTLI_DECODER_ERROR_ALLOC_TREE_GROUPS:
617 case BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MAP:
618 case BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_1:
619 case BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_2:
620 case BROTLI_DECODER_ERROR_ALLOC_BLOCK_TYPE_TREES:
621 return CURLE_OUT_OF_MEMORY;
622 default:
623 break;
624 }
625 return CURLE_WRITE_ERROR;
626}
627
628static CURLcode brotli_init_writer(struct Curl_easy *data,
629 struct contenc_writer *writer)
630{
631 struct brotli_params *bp = (struct brotli_params *) &writer->params;
632 (void) data;
633
634 if(!writer->downstream)
635 return CURLE_WRITE_ERROR;
636
637 bp->br = BrotliDecoderCreateInstance(NULL, NULL, NULL);
638 return bp->br? CURLE_OK: CURLE_OUT_OF_MEMORY;
639}
640
641static CURLcode brotli_unencode_write(struct Curl_easy *data,
642 struct contenc_writer *writer,
643 const char *buf, size_t nbytes)
644{
645 struct brotli_params *bp = (struct brotli_params *) &writer->params;
646 const uint8_t *src = (const uint8_t *) buf;
647 char *decomp;
648 uint8_t *dst;
649 size_t dstleft;
650 CURLcode result = CURLE_OK;
651 BrotliDecoderResult r = BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT;
652
653 if(!bp->br)
654 return CURLE_WRITE_ERROR; /* Stream already ended. */
655
656 decomp = malloc(DSIZ);
657 if(!decomp)
658 return CURLE_OUT_OF_MEMORY;
659
660 while((nbytes || r == BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT) &&
661 result == CURLE_OK) {
662 dst = (uint8_t *) decomp;
663 dstleft = DSIZ;
664 r = BrotliDecoderDecompressStream(bp->br,
665 &nbytes, &src, &dstleft, &dst, NULL);
666 result = Curl_unencode_write(data, writer->downstream,
667 decomp, DSIZ - dstleft);
668 if(result)
669 break;
670 switch(r) {
671 case BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT:
672 case BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT:
673 break;
674 case BROTLI_DECODER_RESULT_SUCCESS:
675 BrotliDecoderDestroyInstance(bp->br);
676 bp->br = NULL;
677 if(nbytes)
678 result = CURLE_WRITE_ERROR;
679 break;
680 default:
681 result = brotli_map_error(BrotliDecoderGetErrorCode(bp->br));
682 break;
683 }
684 }
685 free(decomp);
686 return result;
687}
688
689static void brotli_close_writer(struct Curl_easy *data,
690 struct contenc_writer *writer)
691{
692 struct brotli_params *bp = (struct brotli_params *) &writer->params;
693 (void) data;
694
695 if(bp->br) {
696 BrotliDecoderDestroyInstance(bp->br);
697 bp->br = NULL;
698 }
699}
700
701static const struct content_encoding brotli_encoding = {
702 "br",
703 NULL,
704 brotli_init_writer,
705 brotli_unencode_write,
706 brotli_close_writer,
707 sizeof(struct brotli_params)
708};
709#endif
710
711
712#ifdef HAVE_ZSTD
713/* Writer parameters. */
714struct zstd_params {
715 ZSTD_DStream *zds; /* State structure for zstd. */
716 void *decomp;
717};
718
719static CURLcode zstd_init_writer(struct Curl_easy *data,
720 struct contenc_writer *writer)
721{
722 struct zstd_params *zp = (struct zstd_params *)&writer->params;
723 (void)data;
724
725 if(!writer->downstream)
726 return CURLE_WRITE_ERROR;
727
728 zp->zds = ZSTD_createDStream();
729 zp->decomp = NULL;
730 return zp->zds ? CURLE_OK : CURLE_OUT_OF_MEMORY;
731}
732
733static CURLcode zstd_unencode_write(struct Curl_easy *data,
734 struct contenc_writer *writer,
735 const char *buf, size_t nbytes)
736{
737 CURLcode result = CURLE_OK;
738 struct zstd_params *zp = (struct zstd_params *)&writer->params;
739 ZSTD_inBuffer in;
740 ZSTD_outBuffer out;
741 size_t errorCode;
742
743 if(!zp->decomp) {
744 zp->decomp = malloc(DSIZ);
745 if(!zp->decomp)
746 return CURLE_OUT_OF_MEMORY;
747 }
748 in.pos = 0;
749 in.src = buf;
750 in.size = nbytes;
751
752 for(;;) {
753 out.pos = 0;
754 out.dst = zp->decomp;
755 out.size = DSIZ;
756
757 errorCode = ZSTD_decompressStream(zp->zds, &out, &in);
758 if(ZSTD_isError(errorCode)) {
759 return CURLE_BAD_CONTENT_ENCODING;
760 }
761 if(out.pos > 0) {
762 result = Curl_unencode_write(data, writer->downstream,
763 zp->decomp, out.pos);
764 if(result)
765 break;
766 }
767 if((in.pos == nbytes) && (out.pos < out.size))
768 break;
769 }
770
771 return result;
772}
773
774static void zstd_close_writer(struct Curl_easy *data,
775 struct contenc_writer *writer)
776{
777 struct zstd_params *zp = (struct zstd_params *)&writer->params;
778 (void)data;
779
780 if(zp->decomp) {
781 free(zp->decomp);
782 zp->decomp = NULL;
783 }
784 if(zp->zds) {
785 ZSTD_freeDStream(zp->zds);
786 zp->zds = NULL;
787 }
788}
789
790static const struct content_encoding zstd_encoding = {
791 "zstd",
792 NULL,
793 zstd_init_writer,
794 zstd_unencode_write,
795 zstd_close_writer,
796 sizeof(struct zstd_params)
797};
798#endif
799
800
801/* Identity handler. */
802static CURLcode identity_init_writer(struct Curl_easy *data,
803 struct contenc_writer *writer)
804{
805 (void) data;
806 return writer->downstream? CURLE_OK: CURLE_WRITE_ERROR;
807}
808
809static CURLcode identity_unencode_write(struct Curl_easy *data,
810 struct contenc_writer *writer,
811 const char *buf, size_t nbytes)
812{
813 return Curl_unencode_write(data, writer->downstream, buf, nbytes);
814}
815
816static void identity_close_writer(struct Curl_easy *data,
817 struct contenc_writer *writer)
818{
819 (void) data;
820 (void) writer;
821}
822
823static const struct content_encoding identity_encoding = {
824 "identity",
825 "none",
826 identity_init_writer,
827 identity_unencode_write,
828 identity_close_writer,
829 0
830};
831
832
833/* supported content encodings table. */
834static const struct content_encoding * const encodings[] = {
835 &identity_encoding,
836#ifdef HAVE_LIBZ
837 &deflate_encoding,
838 &gzip_encoding,
839#endif
840#ifdef HAVE_BROTLI
841 &brotli_encoding,
842#endif
843#ifdef HAVE_ZSTD
844 &zstd_encoding,
845#endif
846 NULL
847};
848
849
850/* Return a list of comma-separated names of supported encodings. */
851char *Curl_all_content_encodings(void)
852{
853 size_t len = 0;
854 const struct content_encoding * const *cep;
855 const struct content_encoding *ce;
856 char *ace;
857
858 for(cep = encodings; *cep; cep++) {
859 ce = *cep;
860 if(!strcasecompare(ce->name, CONTENT_ENCODING_DEFAULT))
861 len += strlen(ce->name) + 2;
862 }
863
864 if(!len)
865 return strdup(CONTENT_ENCODING_DEFAULT);
866
867 ace = malloc(len);
868 if(ace) {
869 char *p = ace;
870 for(cep = encodings; *cep; cep++) {
871 ce = *cep;
872 if(!strcasecompare(ce->name, CONTENT_ENCODING_DEFAULT)) {
873 strcpy(p, ce->name);
874 p += strlen(p);
875 *p++ = ',';
876 *p++ = ' ';
877 }
878 }
879 p[-2] = '\0';
880 }
881
882 return ace;
883}
884
885
886/* Real client writer: no downstream. */
887static CURLcode client_init_writer(struct Curl_easy *data,
888 struct contenc_writer *writer)
889{
890 (void) data;
891 return writer->downstream? CURLE_WRITE_ERROR: CURLE_OK;
892}
893
894static CURLcode client_unencode_write(struct Curl_easy *data,
895 struct contenc_writer *writer,
896 const char *buf, size_t nbytes)
897{
898 struct SingleRequest *k = &data->req;
899
900 (void) writer;
901
902 if(!nbytes || k->ignorebody)
903 return CURLE_OK;
904
905 return Curl_client_write(data, CLIENTWRITE_BODY, (char *) buf, nbytes);
906}
907
908static void client_close_writer(struct Curl_easy *data,
909 struct contenc_writer *writer)
910{
911 (void) data;
912 (void) writer;
913}
914
915static const struct content_encoding client_encoding = {
916 NULL,
917 NULL,
918 client_init_writer,
919 client_unencode_write,
920 client_close_writer,
921 0
922};
923
924
925/* Deferred error dummy writer. */
926static CURLcode error_init_writer(struct Curl_easy *data,
927 struct contenc_writer *writer)
928{
929 (void) data;
930 return writer->downstream? CURLE_OK: CURLE_WRITE_ERROR;
931}
932
933static CURLcode error_unencode_write(struct Curl_easy *data,
934 struct contenc_writer *writer,
935 const char *buf, size_t nbytes)
936{
937 char *all = Curl_all_content_encodings();
938
939 (void) writer;
940 (void) buf;
941 (void) nbytes;
942
943 if(!all)
944 return CURLE_OUT_OF_MEMORY;
945 failf(data, "Unrecognized content encoding type. "
946 "libcurl understands %s content encodings.", all);
947 free(all);
948 return CURLE_BAD_CONTENT_ENCODING;
949}
950
951static void error_close_writer(struct Curl_easy *data,
952 struct contenc_writer *writer)
953{
954 (void) data;
955 (void) writer;
956}
957
958static const struct content_encoding error_encoding = {
959 NULL,
960 NULL,
961 error_init_writer,
962 error_unencode_write,
963 error_close_writer,
964 0
965};
966
967/* Create an unencoding writer stage using the given handler. */
968static struct contenc_writer *
969new_unencoding_writer(struct Curl_easy *data,
970 const struct content_encoding *handler,
971 struct contenc_writer *downstream)
972{
973 size_t sz = offsetof(struct contenc_writer, params) + handler->paramsize;
974 struct contenc_writer *writer = (struct contenc_writer *)calloc(1, sz);
975
976 if(writer) {
977 writer->handler = handler;
978 writer->downstream = downstream;
979 if(handler->init_writer(data, writer)) {
980 free(writer);
981 writer = NULL;
982 }
983 }
984
985 return writer;
986}
987
988/* Write data using an unencoding writer stack. "nbytes" is not
989 allowed to be 0. */
990CURLcode Curl_unencode_write(struct Curl_easy *data,
991 struct contenc_writer *writer,
992 const char *buf, size_t nbytes)
993{
994 if(!nbytes)
995 return CURLE_OK;
996 return writer->handler->unencode_write(data, writer, buf, nbytes);
997}
998
999/* Close and clean-up the connection's writer stack. */
1000void Curl_unencode_cleanup(struct Curl_easy *data)
1001{
1002 struct SingleRequest *k = &data->req;
1003 struct contenc_writer *writer = k->writer_stack;
1004
1005 while(writer) {
1006 k->writer_stack = writer->downstream;
1007 writer->handler->close_writer(data, writer);
1008 free(writer);
1009 writer = k->writer_stack;
1010 }
1011}
1012
1013/* Find the content encoding by name. */
1014static const struct content_encoding *find_encoding(const char *name,
1015 size_t len)
1016{
1017 const struct content_encoding * const *cep;
1018
1019 for(cep = encodings; *cep; cep++) {
1020 const struct content_encoding *ce = *cep;
1021 if((strncasecompare(name, ce->name, len) && !ce->name[len]) ||
1022 (ce->alias && strncasecompare(name, ce->alias, len) && !ce->alias[len]))
1023 return ce;
1024 }
1025 return NULL;
1026}
1027
1028/* Set-up the unencoding stack from the Content-Encoding header value.
1029 * See RFC 7231 section 3.1.2.2. */
1030CURLcode Curl_build_unencoding_stack(struct Curl_easy *data,
1031 const char *enclist, int maybechunked)
1032{
1033 struct SingleRequest *k = &data->req;
1034
1035 do {
1036 const char *name;
1037 size_t namelen;
1038
1039 /* Parse a single encoding name. */
1040 while(ISSPACE(*enclist) || *enclist == ',')
1041 enclist++;
1042
1043 name = enclist;
1044
1045 for(namelen = 0; *enclist && *enclist != ','; enclist++)
1046 if(!ISSPACE(*enclist))
1047 namelen = enclist - name + 1;
1048
1049 /* Special case: chunked encoding is handled at the reader level. */
1050 if(maybechunked && namelen == 7 && strncasecompare(name, "chunked", 7)) {
1051 k->chunk = TRUE; /* chunks coming our way. */
1052 Curl_httpchunk_init(data); /* init our chunky engine. */
1053 }
1054 else if(namelen) {
1055 const struct content_encoding *encoding = find_encoding(name, namelen);
1056 struct contenc_writer *writer;
1057
1058 if(!k->writer_stack) {
1059 k->writer_stack = new_unencoding_writer(data, &client_encoding, NULL);
1060
1061 if(!k->writer_stack)
1062 return CURLE_OUT_OF_MEMORY;
1063 }
1064
1065 if(!encoding)
1066 encoding = &error_encoding; /* Defer error at stack use. */
1067
1068 /* Stack the unencoding stage. */
1069 writer = new_unencoding_writer(data, encoding, k->writer_stack);
1070 if(!writer)
1071 return CURLE_OUT_OF_MEMORY;
1072 k->writer_stack = writer;
1073 }
1074 } while(*enclist);
1075
1076 return CURLE_OK;
1077}
1078
1079#else
1080/* Stubs for builds without HTTP. */
1081CURLcode Curl_build_unencoding_stack(struct Curl_easy *data,
1082 const char *enclist, int maybechunked)
1083{
1084 (void) data;
1085 (void) enclist;
1086 (void) maybechunked;
1087 return CURLE_NOT_BUILT_IN;
1088}
1089
1090CURLcode Curl_unencode_write(struct Curl_easy *data,
1091 struct contenc_writer *writer,
1092 const char *buf, size_t nbytes)
1093{
1094 (void) data;
1095 (void) writer;
1096 (void) buf;
1097 (void) nbytes;
1098 return CURLE_NOT_BUILT_IN;
1099}
1100
1101void Curl_unencode_cleanup(struct Curl_easy *data)
1102{
1103 (void) data;
1104}
1105
1106char *Curl_all_content_encodings(void)
1107{
1108 return strdup(CONTENT_ENCODING_DEFAULT); /* Satisfy caller. */
1109}
1110
1111#endif /* CURL_DISABLE_HTTP */
1112