source: UsbWattMeter/trunk/curl-7.47.1/lib/content_encoding.c@ 164

Last change on this file since 164 was 164, checked in by coas-nagasima, 8 years ago

TOPPERS/ECNLサンプルアプリ「USB充電器電力計」を追加
  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
  • Property svn:mime-type set to text/x-csrc
File size: 12.2 KB
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1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2011, 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#ifdef HAVE_LIBZ
26
27#include "urldata.h"
28#include <curl/curl.h>
29#include "sendf.h"
30#include "content_encoding.h"
31#include "curl_memory.h"
32
33#include "memdebug.h"
34
35/* Comment this out if zlib is always going to be at least ver. 1.2.0.4
36 (doing so will reduce code size slightly). */
37#define OLD_ZLIB_SUPPORT 1
38
39#define DSIZ CURL_MAX_WRITE_SIZE /* buffer size for decompressed data */
40
41#define GZIP_MAGIC_0 0x1f
42#define GZIP_MAGIC_1 0x8b
43
44/* gzip flag byte */
45#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
46#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */
47#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
48#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
49#define COMMENT 0x10 /* bit 4 set: file comment present */
50#define RESERVED 0xE0 /* bits 5..7: reserved */
51
52static voidpf
53zalloc_cb(voidpf opaque, unsigned int items, unsigned int size)
54{
55 (void) opaque;
56 /* not a typo, keep it calloc() */
57 return (voidpf) calloc(items, size);
58}
59
60static void
61zfree_cb(voidpf opaque, voidpf ptr)
62{
63 (void) opaque;
64 free(ptr);
65}
66
67static CURLcode
68process_zlib_error(struct connectdata *conn, z_stream *z)
69{
70 struct SessionHandle *data = conn->data;
71 if(z->msg)
72 failf (data, "Error while processing content unencoding: %s",
73 z->msg);
74 else
75 failf (data, "Error while processing content unencoding: "
76 "Unknown failure within decompression software.");
77
78 return CURLE_BAD_CONTENT_ENCODING;
79}
80
81static CURLcode
82exit_zlib(z_stream *z, zlibInitState *zlib_init, CURLcode result)
83{
84 inflateEnd(z);
85 *zlib_init = ZLIB_UNINIT;
86 return result;
87}
88
89static CURLcode
90inflate_stream(struct connectdata *conn,
91 struct SingleRequest *k)
92{
93 int allow_restart = 1;
94 z_stream *z = &k->z; /* zlib state structure */
95 uInt nread = z->avail_in;
96 Bytef *orig_in = z->next_in;
97 int status; /* zlib status */
98 CURLcode result = CURLE_OK; /* Curl_client_write status */
99 char *decomp; /* Put the decompressed data here. */
100
101 /* Dynamically allocate a buffer for decompression because it's uncommonly
102 large to hold on the stack */
103 decomp = malloc(DSIZ);
104 if(decomp == NULL) {
105 return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY);
106 }
107
108 /* because the buffer size is fixed, iteratively decompress and transfer to
109 the client via client_write. */
110 for(;;) {
111 /* (re)set buffer for decompressed output for every iteration */
112 z->next_out = (Bytef *)decomp;
113 z->avail_out = DSIZ;
114
115 status = inflate(z, Z_SYNC_FLUSH);
116 if(status == Z_OK || status == Z_STREAM_END) {
117 allow_restart = 0;
118 if((DSIZ - z->avail_out) && (!k->ignorebody)) {
119 result = Curl_client_write(conn, CLIENTWRITE_BODY, decomp,
120 DSIZ - z->avail_out);
121 /* if !CURLE_OK, clean up, return */
122 if(result) {
123 free(decomp);
124 return exit_zlib(z, &k->zlib_init, result);
125 }
126 }
127
128 /* Done? clean up, return */
129 if(status == Z_STREAM_END) {
130 free(decomp);
131 if(inflateEnd(z) == Z_OK)
132 return exit_zlib(z, &k->zlib_init, result);
133 else
134 return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
135 }
136
137 /* Done with these bytes, exit */
138
139 /* status is always Z_OK at this point! */
140 if(z->avail_in == 0) {
141 free(decomp);
142 return result;
143 }
144 }
145 else if(allow_restart && status == Z_DATA_ERROR) {
146 /* some servers seem to not generate zlib headers, so this is an attempt
147 to fix and continue anyway */
148
149 (void) inflateEnd(z); /* don't care about the return code */
150 if(inflateInit2(z, -MAX_WBITS) != Z_OK) {
151 free(decomp);
152 return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
153 }
154 z->next_in = orig_in;
155 z->avail_in = nread;
156 allow_restart = 0;
157 continue;
158 }
159 else { /* Error; exit loop, handle below */
160 free(decomp);
161 return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
162 }
163 }
164 /* Will never get here */
165}
166
167CURLcode
168Curl_unencode_deflate_write(struct connectdata *conn,
169 struct SingleRequest *k,
170 ssize_t nread)
171{
172 z_stream *z = &k->z; /* zlib state structure */
173
174 /* Initialize zlib? */
175 if(k->zlib_init == ZLIB_UNINIT) {
176 memset(z, 0, sizeof(z_stream));
177 z->zalloc = (alloc_func)zalloc_cb;
178 z->zfree = (free_func)zfree_cb;
179
180 if(inflateInit(z) != Z_OK)
181 return process_zlib_error(conn, z);
182 k->zlib_init = ZLIB_INIT;
183 }
184
185 /* Set the compressed input when this function is called */
186 z->next_in = (Bytef *)k->str;
187 z->avail_in = (uInt)nread;
188
189 /* Now uncompress the data */
190 return inflate_stream(conn, k);
191}
192
193#ifdef OLD_ZLIB_SUPPORT
194/* Skip over the gzip header */
195static enum {
196 GZIP_OK,
197 GZIP_BAD,
198 GZIP_UNDERFLOW
199} check_gzip_header(unsigned char const *data, ssize_t len, ssize_t *headerlen)
200{
201 int method, flags;
202 const ssize_t totallen = len;
203
204 /* The shortest header is 10 bytes */
205 if(len < 10)
206 return GZIP_UNDERFLOW;
207
208 if((data[0] != GZIP_MAGIC_0) || (data[1] != GZIP_MAGIC_1))
209 return GZIP_BAD;
210
211 method = data[2];
212 flags = data[3];
213
214 if(method != Z_DEFLATED || (flags & RESERVED) != 0) {
215 /* Can't handle this compression method or unknown flag */
216 return GZIP_BAD;
217 }
218
219 /* Skip over time, xflags, OS code and all previous bytes */
220 len -= 10;
221 data += 10;
222
223 if(flags & EXTRA_FIELD) {
224 ssize_t extra_len;
225
226 if(len < 2)
227 return GZIP_UNDERFLOW;
228
229 extra_len = (data[1] << 8) | data[0];
230
231 if(len < (extra_len+2))
232 return GZIP_UNDERFLOW;
233
234 len -= (extra_len + 2);
235 data += (extra_len + 2);
236 }
237
238 if(flags & ORIG_NAME) {
239 /* Skip over NUL-terminated file name */
240 while(len && *data) {
241 --len;
242 ++data;
243 }
244 if(!len || *data)
245 return GZIP_UNDERFLOW;
246
247 /* Skip over the NUL */
248 --len;
249 ++data;
250 }
251
252 if(flags & COMMENT) {
253 /* Skip over NUL-terminated comment */
254 while(len && *data) {
255 --len;
256 ++data;
257 }
258 if(!len || *data)
259 return GZIP_UNDERFLOW;
260
261 /* Skip over the NUL */
262 --len;
263 }
264
265 if(flags & HEAD_CRC) {
266 if(len < 2)
267 return GZIP_UNDERFLOW;
268
269 len -= 2;
270 }
271
272 *headerlen = totallen - len;
273 return GZIP_OK;
274}
275#endif
276
277CURLcode
278Curl_unencode_gzip_write(struct connectdata *conn,
279 struct SingleRequest *k,
280 ssize_t nread)
281{
282 z_stream *z = &k->z; /* zlib state structure */
283
284 /* Initialize zlib? */
285 if(k->zlib_init == ZLIB_UNINIT) {
286 memset(z, 0, sizeof(z_stream));
287 z->zalloc = (alloc_func)zalloc_cb;
288 z->zfree = (free_func)zfree_cb;
289
290 if(strcmp(zlibVersion(), "1.2.0.4") >= 0) {
291 /* zlib ver. >= 1.2.0.4 supports transparent gzip decompressing */
292 if(inflateInit2(z, MAX_WBITS+32) != Z_OK) {
293 return process_zlib_error(conn, z);
294 }
295 k->zlib_init = ZLIB_INIT_GZIP; /* Transparent gzip decompress state */
296 }
297 else {
298 /* we must parse the gzip header ourselves */
299 if(inflateInit2(z, -MAX_WBITS) != Z_OK) {
300 return process_zlib_error(conn, z);
301 }
302 k->zlib_init = ZLIB_INIT; /* Initial call state */
303 }
304 }
305
306 if(k->zlib_init == ZLIB_INIT_GZIP) {
307 /* Let zlib handle the gzip decompression entirely */
308 z->next_in = (Bytef *)k->str;
309 z->avail_in = (uInt)nread;
310 /* Now uncompress the data */
311 return inflate_stream(conn, k);
312 }
313
314#ifndef OLD_ZLIB_SUPPORT
315 /* Support for old zlib versions is compiled away and we are running with
316 an old version, so return an error. */
317 return exit_zlib(z, &k->zlib_init, CURLE_FUNCTION_NOT_FOUND);
318
319#else
320 /* This next mess is to get around the potential case where there isn't
321 * enough data passed in to skip over the gzip header. If that happens, we
322 * malloc a block and copy what we have then wait for the next call. If
323 * there still isn't enough (this is definitely a worst-case scenario), we
324 * make the block bigger, copy the next part in and keep waiting.
325 *
326 * This is only required with zlib versions < 1.2.0.4 as newer versions
327 * can handle the gzip header themselves.
328 */
329
330 switch (k->zlib_init) {
331 /* Skip over gzip header? */
332 case ZLIB_INIT:
333 {
334 /* Initial call state */
335 ssize_t hlen;
336
337 switch (check_gzip_header((unsigned char *)k->str, nread, &hlen)) {
338 case GZIP_OK:
339 z->next_in = (Bytef *)k->str + hlen;
340 z->avail_in = (uInt)(nread - hlen);
341 k->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */
342 break;
343
344 case GZIP_UNDERFLOW:
345 /* We need more data so we can find the end of the gzip header. It's
346 * possible that the memory block we malloc here will never be freed if
347 * the transfer abruptly aborts after this point. Since it's unlikely
348 * that circumstances will be right for this code path to be followed in
349 * the first place, and it's even more unlikely for a transfer to fail
350 * immediately afterwards, it should seldom be a problem.
351 */
352 z->avail_in = (uInt)nread;
353 z->next_in = malloc(z->avail_in);
354 if(z->next_in == NULL) {
355 return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY);
356 }
357 memcpy(z->next_in, k->str, z->avail_in);
358 k->zlib_init = ZLIB_GZIP_HEADER; /* Need more gzip header data state */
359 /* We don't have any data to inflate yet */
360 return CURLE_OK;
361
362 case GZIP_BAD:
363 default:
364 return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
365 }
366
367 }
368 break;
369
370 case ZLIB_GZIP_HEADER:
371 {
372 /* Need more gzip header data state */
373 ssize_t hlen;
374 unsigned char *oldblock = z->next_in;
375
376 z->avail_in += (uInt)nread;
377 z->next_in = realloc(z->next_in, z->avail_in);
378 if(z->next_in == NULL) {
379 free(oldblock);
380 return exit_zlib(z, &k->zlib_init, CURLE_OUT_OF_MEMORY);
381 }
382 /* Append the new block of data to the previous one */
383 memcpy(z->next_in + z->avail_in - nread, k->str, nread);
384
385 switch (check_gzip_header(z->next_in, z->avail_in, &hlen)) {
386 case GZIP_OK:
387 /* This is the zlib stream data */
388 free(z->next_in);
389 /* Don't point into the malloced block since we just freed it */
390 z->next_in = (Bytef *)k->str + hlen + nread - z->avail_in;
391 z->avail_in = (uInt)(z->avail_in - hlen);
392 k->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */
393 break;
394
395 case GZIP_UNDERFLOW:
396 /* We still don't have any data to inflate! */
397 return CURLE_OK;
398
399 case GZIP_BAD:
400 default:
401 free(z->next_in);
402 return exit_zlib(z, &k->zlib_init, process_zlib_error(conn, z));
403 }
404
405 }
406 break;
407
408 case ZLIB_GZIP_INFLATING:
409 default:
410 /* Inflating stream state */
411 z->next_in = (Bytef *)k->str;
412 z->avail_in = (uInt)nread;
413 break;
414 }
415
416 if(z->avail_in == 0) {
417 /* We don't have any data to inflate; wait until next time */
418 return CURLE_OK;
419 }
420
421 /* We've parsed the header, now uncompress the data */
422 return inflate_stream(conn, k);
423#endif
424}
425
426void Curl_unencode_cleanup(struct connectdata *conn)
427{
428 struct SessionHandle *data = conn->data;
429 struct SingleRequest *k = &data->req;
430 z_stream *z = &k->z;
431 if(k->zlib_init != ZLIB_UNINIT)
432 (void) exit_zlib(z, &k->zlib_init, CURLE_OK);
433}
434
435#endif /* HAVE_LIBZ */
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