1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2018, 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.haxx.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#ifdef __SYMBIAN32__
32/* zlib pollutes the namespace with this definition */
33#undef WIN32
34#endif
35#endif
36
37#ifdef HAVE_BROTLI
38#include <brotli/decode.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. */
84typedef struct {
85 zlibInitState zlib_init; /* zlib init state */
86 uInt trailerlen; /* Remaining trailer byte count. */
87 z_stream z; /* State structure for zlib. */
88} zlib_params;
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 connectdata *conn, z_stream *z)
108{
109 struct Curl_easy *data = conn->data;
110 if(z->msg)
111 failf(data, "Error while processing content unencoding: %s",
112 z->msg);
113 else
114 failf(data, "Error while processing content unencoding: "
115 "Unknown failure within decompression software.");
116
117 return CURLE_BAD_CONTENT_ENCODING;
118}
119
120static CURLcode
121exit_zlib(struct connectdata *conn,
122 z_stream *z, zlibInitState *zlib_init, CURLcode result)
123{
124 if(*zlib_init == ZLIB_GZIP_HEADER)
125 Curl_safefree(z->next_in);
126
127 if(*zlib_init != ZLIB_UNINIT) {
128 if(inflateEnd(z) != Z_OK && result == CURLE_OK)
129 result = process_zlib_error(conn, z);
130 *zlib_init = ZLIB_UNINIT;
131 }
132
133 return result;
134}
135
136static CURLcode process_trailer(struct connectdata *conn, 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(conn, 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 connectdata *conn,
160 contenc_writer *writer, zlibInitState started)
161{
162 zlib_params *zp = (zlib_params *) &writer->params;
163 z_stream *z = &zp->z; /* zlib state structure */
164 uInt nread = z->avail_in;
165 Bytef *orig_in = z->next_in;
166 bool done = FALSE;
167 CURLcode result = CURLE_OK; /* Curl_client_write status */
168 char *decomp; /* Put the decompressed data here. */
169
170 /* Check state. */
171 if(zp->zlib_init != ZLIB_INIT &&
172 zp->zlib_init != ZLIB_INFLATING &&
173 zp->zlib_init != ZLIB_INIT_GZIP &&
174 zp->zlib_init != ZLIB_GZIP_INFLATING)
175 return exit_zlib(conn, z, &zp->zlib_init, CURLE_WRITE_ERROR);
176
177 /* Dynamically allocate a buffer for decompression because it's uncommonly
178 large to hold on the stack */
179 decomp = malloc(DSIZ);
180 if(decomp == NULL)
181 return exit_zlib(conn, z, &zp->zlib_init, CURLE_OUT_OF_MEMORY);
182
183 /* because the buffer size is fixed, iteratively decompress and transfer to
184 the client via downstream_write function. */
185 while(!done) {
186 int status; /* zlib status */
187 done = TRUE;
188
189 /* (re)set buffer for decompressed output for every iteration */
190 z->next_out = (Bytef *) decomp;
191 z->avail_out = DSIZ;
192
193#ifdef Z_BLOCK
194 /* Z_BLOCK is only available in zlib ver. >= 1.2.0.5 */
195 status = inflate(z, Z_BLOCK);
196#else
197 /* fallback for zlib ver. < 1.2.0.5 */
198 status = inflate(z, Z_SYNC_FLUSH);
199#endif
200
201 /* Flush output data if some. */
202 if(z->avail_out != DSIZ) {
203 if(status == Z_OK || status == Z_STREAM_END) {
204 zp->zlib_init = started; /* Data started. */
205 result = Curl_unencode_write(conn, writer->downstream, decomp,
206 DSIZ - z->avail_out);
207 if(result) {
208 exit_zlib(conn, z, &zp->zlib_init, result);
209 break;
210 }
211 }
212 }
213
214 /* Dispatch by inflate() status. */
215 switch(status) {
216 case Z_OK:
217 /* Always loop: there may be unflushed latched data in zlib state. */
218 done = FALSE;
219 break;
220 case Z_BUF_ERROR:
221 /* No more data to flush: just exit loop. */
222 break;
223 case Z_STREAM_END:
224 result = process_trailer(conn, zp);
225 break;
226 case Z_DATA_ERROR:
227 /* some servers seem to not generate zlib headers, so this is an attempt
228 to fix and continue anyway */
229 if(zp->zlib_init == ZLIB_INIT) {
230 /* Do not use inflateReset2(): only available since zlib 1.2.3.4. */
231 (void) inflateEnd(z); /* don't care about the return code */
232 if(inflateInit2(z, -MAX_WBITS) == Z_OK) {
233 z->next_in = orig_in;
234 z->avail_in = nread;
235 zp->zlib_init = ZLIB_INFLATING;
236 zp->trailerlen = 4; /* Tolerate up to 4 unknown trailer bytes. */
237 done = FALSE;
238 break;
239 }
240 zp->zlib_init = ZLIB_UNINIT; /* inflateEnd() already called. */
241 }
242 /* FALLTHROUGH */
243 default:
244 result = exit_zlib(conn, z, &zp->zlib_init, process_zlib_error(conn, z));
245 break;
246 }
247 }
248 free(decomp);
249
250 /* We're about to leave this call so the `nread' data bytes won't be seen
251 again. If we are in a state that would wrongly allow restart in raw mode
252 at the next call, assume output has already started. */
253 if(nread && zp->zlib_init == ZLIB_INIT)
254 zp->zlib_init = started; /* Cannot restart anymore. */
255
256 return result;
257}
258
259
260/* Deflate handler. */
261static CURLcode deflate_init_writer(struct connectdata *conn,
262 contenc_writer *writer)
263{
264 zlib_params *zp = (zlib_params *) &writer->params;
265 z_stream *z = &zp->z; /* zlib state structure */
266
267 if(!writer->downstream)
268 return CURLE_WRITE_ERROR;
269
270 /* Initialize zlib */
271 z->zalloc = (alloc_func) zalloc_cb;
272 z->zfree = (free_func) zfree_cb;
273
274 if(inflateInit(z) != Z_OK)
275 return process_zlib_error(conn, z);
276 zp->zlib_init = ZLIB_INIT;
277 return CURLE_OK;
278}
279
280static CURLcode deflate_unencode_write(struct connectdata *conn,
281 contenc_writer *writer,
282 const char *buf, size_t nbytes)
283{
284 zlib_params *zp = (zlib_params *) &writer->params;
285 z_stream *z = &zp->z; /* zlib state structure */
286
287 /* Set the compressed input when this function is called */
288 z->next_in = (Bytef *) buf;
289 z->avail_in = (uInt) nbytes;
290
291 if(zp->zlib_init == ZLIB_EXTERNAL_TRAILER)
292 return process_trailer(conn, zp);
293
294 /* Now uncompress the data */
295 return inflate_stream(conn, writer, ZLIB_INFLATING);
296}
297
298static void deflate_close_writer(struct connectdata *conn,
299 contenc_writer *writer)
300{
301 zlib_params *zp = (zlib_params *) &writer->params;
302 z_stream *z = &zp->z; /* zlib state structure */
303
304 exit_zlib(conn, z, &zp->zlib_init, CURLE_OK);
305}
306
307static const content_encoding deflate_encoding = {
308 "deflate",
309 NULL,
310 deflate_init_writer,
311 deflate_unencode_write,
312 deflate_close_writer,
313 sizeof(zlib_params)
314};
315
316
317/* Gzip handler. */
318static CURLcode gzip_init_writer(struct connectdata *conn,
319 contenc_writer *writer)
320{
321 zlib_params *zp = (zlib_params *) &writer->params;
322 z_stream *z = &zp->z; /* zlib state structure */
323
324 if(!writer->downstream)
325 return CURLE_WRITE_ERROR;
326
327 /* Initialize zlib */
328 z->zalloc = (alloc_func) zalloc_cb;
329 z->zfree = (free_func) zfree_cb;
330
331 if(strcmp(zlibVersion(), "1.2.0.4") >= 0) {
332 /* zlib ver. >= 1.2.0.4 supports transparent gzip decompressing */
333 if(inflateInit2(z, MAX_WBITS + 32) != Z_OK) {
334 return process_zlib_error(conn, z);
335 }
336 zp->zlib_init = ZLIB_INIT_GZIP; /* Transparent gzip decompress state */
337 }
338 else {
339 /* we must parse the gzip header and trailer ourselves */
340 if(inflateInit2(z, -MAX_WBITS) != Z_OK) {
341 return process_zlib_error(conn, z);
342 }
343 zp->trailerlen = 8; /* A CRC-32 and a 32-bit input size (RFC 1952, 2.2) */
344 zp->zlib_init = ZLIB_INIT; /* Initial call state */
345 }
346
347 return CURLE_OK;
348}
349
350#ifdef OLD_ZLIB_SUPPORT
351/* Skip over the gzip header */
352static enum {
353 GZIP_OK,
354 GZIP_BAD,
355 GZIP_UNDERFLOW
356} check_gzip_header(unsigned char const *data, ssize_t len, ssize_t *headerlen)
357{
358 int method, flags;
359 const ssize_t totallen = len;
360
361 /* The shortest header is 10 bytes */
362 if(len < 10)
363 return GZIP_UNDERFLOW;
364
365 if((data[0] != GZIP_MAGIC_0) || (data[1] != GZIP_MAGIC_1))
366 return GZIP_BAD;
367
368 method = data[2];
369 flags = data[3];
370
371 if(method != Z_DEFLATED || (flags & RESERVED) != 0) {
372 /* Can't handle this compression method or unknown flag */
373 return GZIP_BAD;
374 }
375
376 /* Skip over time, xflags, OS code and all previous bytes */
377 len -= 10;
378 data += 10;
379
380 if(flags & EXTRA_FIELD) {
381 ssize_t extra_len;
382
383 if(len < 2)
384 return GZIP_UNDERFLOW;
385
386 extra_len = (data[1] << 8) | data[0];
387
388 if(len < (extra_len + 2))
389 return GZIP_UNDERFLOW;
390
391 len -= (extra_len + 2);
392 data += (extra_len + 2);
393 }
394
395 if(flags & ORIG_NAME) {
396 /* Skip over NUL-terminated file name */
397 while(len && *data) {
398 --len;
399 ++data;
400 }
401 if(!len || *data)
402 return GZIP_UNDERFLOW;
403
404 /* Skip over the NUL */
405 --len;
406 ++data;
407 }
408
409 if(flags & COMMENT) {
410 /* Skip over NUL-terminated comment */
411 while(len && *data) {
412 --len;
413 ++data;
414 }
415 if(!len || *data)
416 return GZIP_UNDERFLOW;
417
418 /* Skip over the NUL */
419 --len;
420 }
421
422 if(flags & HEAD_CRC) {
423 if(len < 2)
424 return GZIP_UNDERFLOW;
425
426 len -= 2;
427 }
428
429 *headerlen = totallen - len;
430 return GZIP_OK;
431}
432#endif
433
434static CURLcode gzip_unencode_write(struct connectdata *conn,
435 contenc_writer *writer,
436 const char *buf, size_t nbytes)
437{
438 zlib_params *zp = (zlib_params *) &writer->params;
439 z_stream *z = &zp->z; /* zlib state structure */
440
441 if(zp->zlib_init == ZLIB_INIT_GZIP) {
442 /* Let zlib handle the gzip decompression entirely */
443 z->next_in = (Bytef *) buf;
444 z->avail_in = (uInt) nbytes;
445 /* Now uncompress the data */
446 return inflate_stream(conn, writer, ZLIB_INIT_GZIP);
447 }
448
449#ifndef OLD_ZLIB_SUPPORT
450 /* Support for old zlib versions is compiled away and we are running with
451 an old version, so return an error. */
452 return exit_zlib(conn, z, &zp->zlib_init, CURLE_WRITE_ERROR);
453
454#else
455 /* This next mess is to get around the potential case where there isn't
456 * enough data passed in to skip over the gzip header. If that happens, we
457 * malloc a block and copy what we have then wait for the next call. If
458 * there still isn't enough (this is definitely a worst-case scenario), we
459 * make the block bigger, copy the next part in and keep waiting.
460 *
461 * This is only required with zlib versions < 1.2.0.4 as newer versions
462 * can handle the gzip header themselves.
463 */
464
465 switch(zp->zlib_init) {
466 /* Skip over gzip header? */
467 case ZLIB_INIT:
468 {
469 /* Initial call state */
470 ssize_t hlen;
471
472 switch(check_gzip_header((unsigned char *) buf, nbytes, &hlen)) {
473 case GZIP_OK:
474 z->next_in = (Bytef *) buf + hlen;
475 z->avail_in = (uInt) (nbytes - hlen);
476 zp->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */
477 break;
478
479 case GZIP_UNDERFLOW:
480 /* We need more data so we can find the end of the gzip header. It's
481 * possible that the memory block we malloc here will never be freed if
482 * the transfer abruptly aborts after this point. Since it's unlikely
483 * that circumstances will be right for this code path to be followed in
484 * the first place, and it's even more unlikely for a transfer to fail
485 * immediately afterwards, it should seldom be a problem.
486 */
487 z->avail_in = (uInt) nbytes;
488 z->next_in = malloc(z->avail_in);
489 if(z->next_in == NULL) {
490 return exit_zlib(conn, z, &zp->zlib_init, CURLE_OUT_OF_MEMORY);
491 }
492 memcpy(z->next_in, buf, z->avail_in);
493 zp->zlib_init = ZLIB_GZIP_HEADER; /* Need more gzip header data state */
494 /* We don't have any data to inflate yet */
495 return CURLE_OK;
496
497 case GZIP_BAD:
498 default:
499 return exit_zlib(conn, z, &zp->zlib_init, process_zlib_error(conn, z));
500 }
501
502 }
503 break;
504
505 case ZLIB_GZIP_HEADER:
506 {
507 /* Need more gzip header data state */
508 ssize_t hlen;
509 z->avail_in += (uInt) nbytes;
510 z->next_in = Curl_saferealloc(z->next_in, z->avail_in);
511 if(z->next_in == NULL) {
512 return exit_zlib(conn, z, &zp->zlib_init, CURLE_OUT_OF_MEMORY);
513 }
514 /* Append the new block of data to the previous one */
515 memcpy(z->next_in + z->avail_in - nbytes, buf, nbytes);
516
517 switch(check_gzip_header(z->next_in, z->avail_in, &hlen)) {
518 case GZIP_OK:
519 /* This is the zlib stream data */
520 free(z->next_in);
521 /* Don't point into the malloced block since we just freed it */
522 z->next_in = (Bytef *) buf + hlen + nbytes - z->avail_in;
523 z->avail_in = (uInt) (z->avail_in - hlen);
524 zp->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */
525 break;
526
527 case GZIP_UNDERFLOW:
528 /* We still don't have any data to inflate! */
529 return CURLE_OK;
530
531 case GZIP_BAD:
532 default:
533 return exit_zlib(conn, z, &zp->zlib_init, process_zlib_error(conn, z));
534 }
535
536 }
537 break;
538
539 case ZLIB_EXTERNAL_TRAILER:
540 z->next_in = (Bytef *) buf;
541 z->avail_in = (uInt) nbytes;
542 return process_trailer(conn, zp);
543
544 case ZLIB_GZIP_INFLATING:
545 default:
546 /* Inflating stream state */
547 z->next_in = (Bytef *) buf;
548 z->avail_in = (uInt) nbytes;
549 break;
550 }
551
552 if(z->avail_in == 0) {
553 /* We don't have any data to inflate; wait until next time */
554 return CURLE_OK;
555 }
556
557 /* We've parsed the header, now uncompress the data */
558 return inflate_stream(conn, writer, ZLIB_GZIP_INFLATING);
559#endif
560}
561
562static void gzip_close_writer(struct connectdata *conn,
563 contenc_writer *writer)
564{
565 zlib_params *zp = (zlib_params *) &writer->params;
566 z_stream *z = &zp->z; /* zlib state structure */
567
568 exit_zlib(conn, z, &zp->zlib_init, CURLE_OK);
569}
570
571static const content_encoding gzip_encoding = {
572 "gzip",
573 "x-gzip",
574 gzip_init_writer,
575 gzip_unencode_write,
576 gzip_close_writer,
577 sizeof(zlib_params)
578};
579
580#endif /* HAVE_LIBZ */
581
582
583#ifdef HAVE_BROTLI
584
585/* Writer parameters. */
586typedef struct {
587 BrotliDecoderState *br; /* State structure for brotli. */
588} brotli_params;
589
590
591static CURLcode brotli_map_error(BrotliDecoderErrorCode be)
592{
593 switch(be) {
594 case BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_NIBBLE:
595 case BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_META_NIBBLE:
596 case BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_ALPHABET:
597 case BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_SAME:
598 case BROTLI_DECODER_ERROR_FORMAT_CL_SPACE:
599 case BROTLI_DECODER_ERROR_FORMAT_HUFFMAN_SPACE:
600 case BROTLI_DECODER_ERROR_FORMAT_CONTEXT_MAP_REPEAT:
601 case BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_1:
602 case BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_2:
603 case BROTLI_DECODER_ERROR_FORMAT_TRANSFORM:
604 case BROTLI_DECODER_ERROR_FORMAT_DICTIONARY:
605 case BROTLI_DECODER_ERROR_FORMAT_WINDOW_BITS:
606 case BROTLI_DECODER_ERROR_FORMAT_PADDING_1:
607 case BROTLI_DECODER_ERROR_FORMAT_PADDING_2:
608#ifdef BROTLI_DECODER_ERROR_COMPOUND_DICTIONARY
609 case BROTLI_DECODER_ERROR_COMPOUND_DICTIONARY:
610#endif
611#ifdef BROTLI_DECODER_ERROR_DICTIONARY_NOT_SET
612 case BROTLI_DECODER_ERROR_DICTIONARY_NOT_SET:
613#endif
614 case BROTLI_DECODER_ERROR_INVALID_ARGUMENTS:
615 return CURLE_BAD_CONTENT_ENCODING;
616 case BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MODES:
617 case BROTLI_DECODER_ERROR_ALLOC_TREE_GROUPS:
618 case BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MAP:
619 case BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_1:
620 case BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_2:
621 case BROTLI_DECODER_ERROR_ALLOC_BLOCK_TYPE_TREES:
622 return CURLE_OUT_OF_MEMORY;
623 default:
624 break;
625 }
626 return CURLE_WRITE_ERROR;
627}
628
629static CURLcode brotli_init_writer(struct connectdata *conn,
630 contenc_writer *writer)
631{
632 brotli_params *bp = (brotli_params *) &writer->params;
633
634 (void) conn;
635
636 if(!writer->downstream)
637 return CURLE_WRITE_ERROR;
638
639 bp->br = BrotliDecoderCreateInstance(NULL, NULL, NULL);
640 return bp->br? CURLE_OK: CURLE_OUT_OF_MEMORY;
641}
642
643static CURLcode brotli_unencode_write(struct connectdata *conn,
644 contenc_writer *writer,
645 const char *buf, size_t nbytes)
646{
647 brotli_params *bp = (brotli_params *) &writer->params;
648 const uint8_t *src = (const uint8_t *) buf;
649 char *decomp;
650 uint8_t *dst;
651 size_t dstleft;
652 CURLcode result = CURLE_OK;
653 BrotliDecoderResult r = BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT;
654
655 if(!bp->br)
656 return CURLE_WRITE_ERROR; /* Stream already ended. */
657
658 decomp = malloc(DSIZ);
659 if(!decomp)
660 return CURLE_OUT_OF_MEMORY;
661
662 while((nbytes || r == BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT) &&
663 result == CURLE_OK) {
664 dst = (uint8_t *) decomp;
665 dstleft = DSIZ;
666 r = BrotliDecoderDecompressStream(bp->br,
667 &nbytes, &src, &dstleft, &dst, NULL);
668 result = Curl_unencode_write(conn, writer->downstream,
669 decomp, DSIZ - dstleft);
670 if(result)
671 break;
672 switch(r) {
673 case BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT:
674 case BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT:
675 break;
676 case BROTLI_DECODER_RESULT_SUCCESS:
677 BrotliDecoderDestroyInstance(bp->br);
678 bp->br = NULL;
679 if(nbytes)
680 result = CURLE_WRITE_ERROR;
681 break;
682 default:
683 result = brotli_map_error(BrotliDecoderGetErrorCode(bp->br));
684 break;
685 }
686 }
687 free(decomp);
688 return result;
689}
690
691static void brotli_close_writer(struct connectdata *conn,
692 contenc_writer *writer)
693{
694 brotli_params *bp = (brotli_params *) &writer->params;
695
696 (void) conn;
697
698 if(bp->br) {
699 BrotliDecoderDestroyInstance(bp->br);
700 bp->br = NULL;
701 }
702}
703
704static const content_encoding brotli_encoding = {
705 "br",
706 NULL,
707 brotli_init_writer,
708 brotli_unencode_write,
709 brotli_close_writer,
710 sizeof(brotli_params)
711};
712#endif
713
714
715/* Identity handler. */
716static CURLcode identity_init_writer(struct connectdata *conn,
717 contenc_writer *writer)
718{
719 (void) conn;
720 return writer->downstream? CURLE_OK: CURLE_WRITE_ERROR;
721}
722
723static CURLcode identity_unencode_write(struct connectdata *conn,
724 contenc_writer *writer,
725 const char *buf, size_t nbytes)
726{
727 return Curl_unencode_write(conn, writer->downstream, buf, nbytes);
728}
729
730static void identity_close_writer(struct connectdata *conn,
731 contenc_writer *writer)
732{
733 (void) conn;
734 (void) writer;
735}
736
737static const content_encoding identity_encoding = {
738 "identity",
739 "none",
740 identity_init_writer,
741 identity_unencode_write,
742 identity_close_writer,
743 0
744};
745
746
747/* supported content encodings table. */
748static const content_encoding * const encodings[] = {
749 &identity_encoding,
750#ifdef HAVE_LIBZ
751 &deflate_encoding,
752 &gzip_encoding,
753#endif
754#ifdef HAVE_BROTLI
755 &brotli_encoding,
756#endif
757 NULL
758};
759
760
761/* Return a list of comma-separated names of supported encodings. */
762char *Curl_all_content_encodings(void)
763{
764 size_t len = 0;
765 const content_encoding * const *cep;
766 const content_encoding *ce;
767 char *ace;
768
769 for(cep = encodings; *cep; cep++) {
770 ce = *cep;
771 if(!strcasecompare(ce->name, CONTENT_ENCODING_DEFAULT))
772 len += strlen(ce->name) + 2;
773 }
774
775 if(!len)
776 return strdup(CONTENT_ENCODING_DEFAULT);
777
778 ace = malloc(len);
779 if(ace) {
780 char *p = ace;
781 for(cep = encodings; *cep; cep++) {
782 ce = *cep;
783 if(!strcasecompare(ce->name, CONTENT_ENCODING_DEFAULT)) {
784 strcpy(p, ce->name);
785 p += strlen(p);
786 *p++ = ',';
787 *p++ = ' ';
788 }
789 }
790 p[-2] = '\0';
791 }
792
793 return ace;
794}
795
796
797/* Real client writer: no downstream. */
798static CURLcode client_init_writer(struct connectdata *conn,
799 contenc_writer *writer)
800{
801 (void) conn;
802 return writer->downstream? CURLE_WRITE_ERROR: CURLE_OK;
803}
804
805static CURLcode client_unencode_write(struct connectdata *conn,
806 contenc_writer *writer,
807 const char *buf, size_t nbytes)
808{
809 struct Curl_easy *data = conn->data;
810 struct SingleRequest *k = &data->req;
811
812 (void) writer;
813
814 if(!nbytes || k->ignorebody)
815 return CURLE_OK;
816
817 return Curl_client_write(conn, CLIENTWRITE_BODY, (char *) buf, nbytes);
818}
819
820static void client_close_writer(struct connectdata *conn,
821 contenc_writer *writer)
822{
823 (void) conn;
824 (void) writer;
825}
826
827static const content_encoding client_encoding = {
828 NULL,
829 NULL,
830 client_init_writer,
831 client_unencode_write,
832 client_close_writer,
833 0
834};
835
836
837/* Deferred error dummy writer. */
838static CURLcode error_init_writer(struct connectdata *conn,
839 contenc_writer *writer)
840{
841 (void) conn;
842 return writer->downstream? CURLE_OK: CURLE_WRITE_ERROR;
843}
844
845static CURLcode error_unencode_write(struct connectdata *conn,
846 contenc_writer *writer,
847 const char *buf, size_t nbytes)
848{
849 char *all = Curl_all_content_encodings();
850
851 (void) writer;
852 (void) buf;
853 (void) nbytes;
854
855 if(!all)
856 return CURLE_OUT_OF_MEMORY;
857 failf(conn->data, "Unrecognized content encoding type. "
858 "libcurl understands %s content encodings.", all);
859 free(all);
860 return CURLE_BAD_CONTENT_ENCODING;
861}
862
863static void error_close_writer(struct connectdata *conn,
864 contenc_writer *writer)
865{
866 (void) conn;
867 (void) writer;
868}
869
870static const content_encoding error_encoding = {
871 NULL,
872 NULL,
873 error_init_writer,
874 error_unencode_write,
875 error_close_writer,
876 0
877};
878
879/* Create an unencoding writer stage using the given handler. */
880static contenc_writer *new_unencoding_writer(struct connectdata *conn,
881 const content_encoding *handler,
882 contenc_writer *downstream)
883{
884 size_t sz = offsetof(contenc_writer, params) + handler->paramsize;
885 contenc_writer *writer = (contenc_writer *) calloc(1, sz);
886
887 if(writer) {
888 writer->handler = handler;
889 writer->downstream = downstream;
890 if(handler->init_writer(conn, writer)) {
891 free(writer);
892 writer = NULL;
893 }
894 }
895
896 return writer;
897}
898
899/* Write data using an unencoding writer stack. */
900CURLcode Curl_unencode_write(struct connectdata *conn, contenc_writer *writer,
901 const char *buf, size_t nbytes)
902{
903 if(!nbytes)
904 return CURLE_OK;
905 return writer->handler->unencode_write(conn, writer, buf, nbytes);
906}
907
908/* Close and clean-up the connection's writer stack. */
909void Curl_unencode_cleanup(struct connectdata *conn)
910{
911 struct Curl_easy *data = conn->data;
912 struct SingleRequest *k = &data->req;
913 contenc_writer *writer = k->writer_stack;
914
915 while(writer) {
916 k->writer_stack = writer->downstream;
917 writer->handler->close_writer(conn, writer);
918 free(writer);
919 writer = k->writer_stack;
920 }
921}
922
923/* Find the content encoding by name. */
924static const content_encoding *find_encoding(const char *name, size_t len)
925{
926 const content_encoding * const *cep;
927
928 for(cep = encodings; *cep; cep++) {
929 const content_encoding *ce = *cep;
930 if((strncasecompare(name, ce->name, len) && !ce->name[len]) ||
931 (ce->alias && strncasecompare(name, ce->alias, len) && !ce->alias[len]))
932 return ce;
933 }
934 return NULL;
935}
936
937/* Set-up the unencoding stack from the Content-Encoding header value.
938 * See RFC 7231 section 3.1.2.2. */
939CURLcode Curl_build_unencoding_stack(struct connectdata *conn,
940 const char *enclist, int maybechunked)
941{
942 struct Curl_easy *data = conn->data;
943 struct SingleRequest *k = &data->req;
944
945 do {
946 const char *name;
947 size_t namelen;
948
949 /* Parse a single encoding name. */
950 while(ISSPACE(*enclist) || *enclist == ',')
951 enclist++;
952
953 name = enclist;
954
955 for(namelen = 0; *enclist && *enclist != ','; enclist++)
956 if(!ISSPACE(*enclist))
957 namelen = enclist - name + 1;
958
959 /* Special case: chunked encoding is handled at the reader level. */
960 if(maybechunked && namelen == 7 && strncasecompare(name, "chunked", 7)) {
961 k->chunk = TRUE; /* chunks coming our way. */
962 Curl_httpchunk_init(conn); /* init our chunky engine. */
963 }
964 else if(namelen) {
965 const content_encoding *encoding = find_encoding(name, namelen);
966 contenc_writer *writer;
967
968 if(!k->writer_stack) {
969 k->writer_stack = new_unencoding_writer(conn, &client_encoding, NULL);
970
971 if(!k->writer_stack)
972 return CURLE_OUT_OF_MEMORY;
973 }
974
975 if(!encoding)
976 encoding = &error_encoding; /* Defer error at stack use. */
977
978 /* Stack the unencoding stage. */
979 writer = new_unencoding_writer(conn, encoding, k->writer_stack);
980 if(!writer)
981 return CURLE_OUT_OF_MEMORY;
982 k->writer_stack = writer;
983 }
984 } while(*enclist);
985
986 return CURLE_OK;
987}
988
989#else
990/* Stubs for builds without HTTP. */
991CURLcode Curl_build_unencoding_stack(struct connectdata *conn,
992 const char *enclist, int maybechunked)
993{
994 (void) conn;
995 (void) enclist;
996 (void) maybechunked;
997 return CURLE_NOT_BUILT_IN;
998}
999
1000CURLcode Curl_unencode_write(struct connectdata *conn, contenc_writer *writer,
1001 const char *buf, size_t nbytes)
1002{
1003 (void) conn;
1004 (void) writer;
1005 (void) buf;
1006 (void) nbytes;
1007 return CURLE_NOT_BUILT_IN;
1008}
1009
1010void Curl_unencode_cleanup(struct connectdata *conn)
1011{
1012 (void) conn;
1013}
1014
1015char *Curl_all_content_encodings(void)
1016{
1017 return strdup(CONTENT_ENCODING_DEFAULT); /* Satisfy caller. */
1018}
1019
1020#endif /* CURL_DISABLE_HTTP */
1021