Annotation of embedaddon/php/ext/fileinfo/libmagic/compress.c, revision 1.1.1.1
1.1 misho 1: /*
2: * Copyright (c) Ian F. Darwin 1986-1995.
3: * Software written by Ian F. Darwin and others;
4: * maintained 1995-present by Christos Zoulas and others.
5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: * 1. Redistributions of source code must retain the above copyright
10: * notice immediately at the beginning of the file, without modification,
11: * this list of conditions, and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: *
16: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20: * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26: * SUCH DAMAGE.
27: */
28: /*
29: * compress routines:
30: * zmagic() - returns 0 if not recognized, uncompresses and prints
31: * information if recognized
32: * uncompress(method, old, n, newch) - uncompress old into new,
33: * using method, return sizeof new
34: */
35: #include "config.h"
36: #include "file.h"
37:
38: #ifndef lint
39: FILE_RCSID("@(#)$File: compress.c,v 1.63 2009/03/23 14:21:51 christos Exp $")
40: #endif
41:
42: #include "magic.h"
43: #include <stdlib.h>
44: #ifdef HAVE_UNISTD_H
45: #include <unistd.h>
46: #endif
47: #include <string.h>
48: #include <errno.h>
49: #include <sys/types.h>
50: #ifndef PHP_WIN32
51: #include <sys/ioctl.h>
52: #endif
53: #ifdef HAVE_SYS_WAIT_H
54: #include <sys/wait.h>
55: #endif
56: #if defined(HAVE_SYS_TIME_H)
57: #include <sys/time.h>
58: #endif
59: #if defined(HAVE_ZLIB_H) && defined(HAVE_LIBZ)
60: #define BUILTIN_DECOMPRESS
61: #include <zlib.h>
62: #endif
63:
64: #undef FIONREAD
65:
66:
67: private const struct {
68: const char magic[8];
69: size_t maglen;
70: const char *argv[3];
71: int silent;
72: } compr[] = {
73: { "\037\235", 2, { "gzip", "-cdq", NULL }, 1 }, /* compressed */
74: /* Uncompress can get stuck; so use gzip first if we have it
75: * Idea from Damien Clark, thanks! */
76: { "\037\235", 2, { "uncompress", "-c", NULL }, 1 }, /* compressed */
77: { "\037\213", 2, { "gzip", "-cdq", NULL }, 1 }, /* gzipped */
78: { "\037\236", 2, { "gzip", "-cdq", NULL }, 1 }, /* frozen */
79: { "\037\240", 2, { "gzip", "-cdq", NULL }, 1 }, /* SCO LZH */
80: /* the standard pack utilities do not accept standard input */
81: { "\037\036", 2, { "gzip", "-cdq", NULL }, 0 }, /* packed */
82: { "PK\3\4", 4, { "gzip", "-cdq", NULL }, 1 }, /* pkzipped, */
83: /* ...only first file examined */
84: { "BZh", 3, { "bzip2", "-cd", NULL }, 1 }, /* bzip2-ed */
85: { "LZIP", 4, { "lzip", "-cdq", NULL }, 1 },
86: { "\3757zXZ\0",6,{ "xz", "-cd", NULL }, 1 }, /* XZ Utils */
87: };
88:
89: #define NODATA ((size_t)~0)
90:
91: private ssize_t swrite(int, const void *, size_t);
92: #ifdef PHP_FILEINFO_UNCOMPRESS
93: private size_t uncompressbuf(struct magic_set *, int, size_t,
94: const unsigned char *, unsigned char **, size_t);
95: #ifdef BUILTIN_DECOMPRESS
96: private size_t uncompressgzipped(struct magic_set *, const unsigned char *,
97: unsigned char **, size_t);
98: #endif
99:
100: protected int
101: file_zmagic(struct magic_set *ms, int fd, const char *name,
102: const unsigned char *buf, size_t nbytes)
103: {
104: unsigned char *newbuf = NULL;
105: size_t i, nsz;
106: int rv = 0;
107: int mime = ms->flags & MAGIC_MIME;
108: size_t ncompr;
109:
110: if ((ms->flags & MAGIC_COMPRESS) == 0)
111: return 0;
112:
113: ncompr = sizeof(compr) / sizeof(compr[0]);
114:
115: for (i = 0; i < ncompr; i++) {
116: if (nbytes < compr[i].maglen)
117: continue;
118: if (memcmp(buf, compr[i].magic, compr[i].maglen) == 0 &&
119: (nsz = uncompressbuf(ms, fd, i, buf, &newbuf,
120: nbytes)) != NODATA) {
121: ms->flags &= ~MAGIC_COMPRESS;
122: rv = -1;
123: if (file_buffer(ms, -1, name, newbuf, nsz) == -1)
124: goto error;
125:
126: if (mime == MAGIC_MIME || mime == 0) {
127: if (file_printf(ms, mime ?
128: " compressed-encoding=" : " (") == -1)
129: goto error;
130: }
131:
132: if ((mime == 0 || mime & MAGIC_MIME_ENCODING) &&
133: file_buffer(ms, -1, NULL, buf, nbytes) == -1)
134: goto error;
135:
136: if (!mime && file_printf(ms, ")") == -1)
137: goto error;
138: rv = 1;
139: break;
140: }
141: }
142: error:
143: if (newbuf)
144: efree(newbuf);
145: ms->flags |= MAGIC_COMPRESS;
146: return rv;
147: }
148: #endif
149:
150: /*
151: * `safe' write for sockets and pipes.
152: */
153: private ssize_t
154: swrite(int fd, const void *buf, size_t n)
155: {
156: int rv;
157: size_t rn = n;
158:
159: do
160: switch (rv = write(fd, buf, n)) {
161: case -1:
162: if (errno == EINTR)
163: continue;
164: return -1;
165: default:
166: n -= rv;
167: buf = ((const char *)buf) + rv;
168: break;
169: }
170: while (n > 0);
171: return rn;
172: }
173:
174:
175: /*
176: * `safe' read for sockets and pipes.
177: */
178: protected ssize_t
179: sread(int fd, void *buf, size_t n, int canbepipe)
180: {
181: int rv;
182: #ifdef FIONREAD
183: int t = 0;
184: #endif
185: size_t rn = n;
186:
187: if (fd == STDIN_FILENO)
188: goto nocheck;
189:
190: #ifdef FIONREAD
191: if ((canbepipe && (ioctl(fd, FIONREAD, &t) == -1)) || (t == 0)) {
192: #ifdef FD_ZERO
193: int cnt;
194: for (cnt = 0;; cnt++) {
195: fd_set check;
196: struct timeval tout = {0, 100 * 1000};
197: int selrv;
198:
199: FD_ZERO(&check);
200: FD_SET(fd, &check);
201:
202: /*
203: * Avoid soft deadlock: do not read if there
204: * is nothing to read from sockets and pipes.
205: */
206: selrv = select(fd + 1, &check, NULL, NULL, &tout);
207: if (selrv == -1) {
208: if (errno == EINTR || errno == EAGAIN)
209: continue;
210: } else if (selrv == 0 && cnt >= 5) {
211: return 0;
212: } else
213: break;
214: }
215: #endif
216: (void)ioctl(fd, FIONREAD, &t);
217: }
218:
219: if (t > 0 && (size_t)t < n) {
220: n = t;
221: rn = n;
222: }
223: #endif
224:
225: nocheck:
226: do
227: switch ((rv = read(fd, buf, n))) {
228: case -1:
229: if (errno == EINTR)
230: continue;
231: return -1;
232: case 0:
233: return rn - n;
234: default:
235: n -= rv;
236: buf = ((char *)buf) + rv;
237: break;
238: }
239: while (n > 0);
240: return rn;
241: }
242:
243: protected int
244: file_pipe2file(struct magic_set *ms, int fd, const void *startbuf,
245: size_t nbytes)
246: {
247: char buf[4096];
248: int r, tfd;
249:
250: (void)strlcpy(buf, "/tmp/file.XXXXXX", sizeof buf);
251: #ifndef HAVE_MKSTEMP
252: {
253: char *ptr = mktemp(buf);
254: tfd = open(ptr, O_RDWR|O_TRUNC|O_EXCL|O_CREAT, 0600);
255: r = errno;
256: (void)unlink(ptr);
257: errno = r;
258: }
259: #else
260: tfd = mkstemp(buf);
261: r = errno;
262: (void)unlink(buf);
263: errno = r;
264: #endif
265: if (tfd == -1) {
266: file_error(ms, errno,
267: "cannot create temporary file for pipe copy");
268: return -1;
269: }
270:
271: if (swrite(tfd, startbuf, nbytes) != (ssize_t)nbytes)
272: r = 1;
273: else {
274: while ((r = sread(fd, buf, sizeof(buf), 1)) > 0)
275: if (swrite(tfd, buf, (size_t)r) != r)
276: break;
277: }
278:
279: switch (r) {
280: case -1:
281: file_error(ms, errno, "error copying from pipe to temp file");
282: return -1;
283: case 0:
284: break;
285: default:
286: file_error(ms, errno, "error while writing to temp file");
287: return -1;
288: }
289:
290: /*
291: * We duplicate the file descriptor, because fclose on a
292: * tmpfile will delete the file, but any open descriptors
293: * can still access the phantom inode.
294: */
295: if ((fd = dup2(tfd, fd)) == -1) {
296: file_error(ms, errno, "could not dup descriptor for temp file");
297: return -1;
298: }
299: (void)close(tfd);
300: if (lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) {
301: file_badseek(ms);
302: return -1;
303: }
304: return fd;
305: }
306:
307: #ifdef PHP_FILEINFO_UNCOMPRESS
308: #ifdef BUILTIN_DECOMPRESS
309:
310: #define FHCRC (1 << 1)
311: #define FEXTRA (1 << 2)
312: #define FNAME (1 << 3)
313: #define FCOMMENT (1 << 4)
314:
315:
316: private size_t
317: uncompressgzipped(struct magic_set *ms, const unsigned char *old,
318: unsigned char **newch, size_t n)
319: {
320: unsigned char flg = old[3];
321: size_t data_start = 10;
322: z_stream z;
323: int rc;
324:
325: if (flg & FEXTRA) {
326: if (data_start+1 >= n)
327: return 0;
328: data_start += 2 + old[data_start] + old[data_start + 1] * 256;
329: }
330: if (flg & FNAME) {
331: while(data_start < n && old[data_start])
332: data_start++;
333: data_start++;
334: }
335: if(flg & FCOMMENT) {
336: while(data_start < n && old[data_start])
337: data_start++;
338: data_start++;
339: }
340: if(flg & FHCRC)
341: data_start += 2;
342:
343: if (data_start >= n)
344: return 0;
345: *newch = (unsigned char *)emalloc(HOWMANY + 1));
346:
347: /* XXX: const castaway, via strchr */
348: z.next_in = (Bytef *)strchr((const char *)old + data_start,
349: old[data_start]);
350: z.avail_in = n - data_start;
351: z.next_out = *newch;
352: z.avail_out = HOWMANY;
353: z.zalloc = Z_NULL;
354: z.zfree = Z_NULL;
355: z.opaque = Z_NULL;
356:
357: rc = inflateInit2(&z, -15);
358: if (rc != Z_OK) {
359: file_error(ms, 0, "zlib: %s", z.msg);
360: return 0;
361: }
362:
363: rc = inflate(&z, Z_SYNC_FLUSH);
364: if (rc != Z_OK && rc != Z_STREAM_END) {
365: file_error(ms, 0, "zlib: %s", z.msg);
366: return 0;
367: }
368:
369: n = (size_t)z.total_out;
370: (void)inflateEnd(&z);
371:
372: /* let's keep the nul-terminate tradition */
373: (*newch)[n] = '\0';
374:
375: return n;
376: }
377: #endif
378:
379: private size_t
380: uncompressbuf(struct magic_set *ms, int fd, size_t method,
381: const unsigned char *old, unsigned char **newch, size_t n)
382: {
383: int fdin[2], fdout[2];
384: int r;
385:
386: #ifdef BUILTIN_DECOMPRESS
387: /* FIXME: This doesn't cope with bzip2 */
388: if (method == 2)
389: return uncompressgzipped(ms, old, newch, n);
390: #endif
391: (void)fflush(stdout);
392: (void)fflush(stderr);
393:
394: if ((fd != -1 && pipe(fdin) == -1) || pipe(fdout) == -1) {
395: file_error(ms, errno, "cannot create pipe");
396: return NODATA;
397: }
398: switch (fork()) {
399: case 0: /* child */
400: (void) close(0);
401: if (fd != -1) {
402: (void) dup(fd);
403: (void) lseek(0, (off_t)0, SEEK_SET);
404: } else {
405: (void) dup(fdin[0]);
406: (void) close(fdin[0]);
407: (void) close(fdin[1]);
408: }
409:
410: (void) close(1);
411: (void) dup(fdout[1]);
412: (void) close(fdout[0]);
413: (void) close(fdout[1]);
414: #ifndef DEBUG
415: if (compr[method].silent)
416: (void)close(2);
417: #endif
418:
419: (void)execvp(compr[method].argv[0],
420: (char *const *)(intptr_t)compr[method].argv);
421: #ifdef DEBUG
422: (void)fprintf(stderr, "exec `%s' failed (%s)\n",
423: compr[method].argv[0], strerror(errno));
424: #endif
425: exit(1);
426: /*NOTREACHED*/
427: case -1:
428: file_error(ms, errno, "could not fork");
429: return NODATA;
430:
431: default: /* parent */
432: (void) close(fdout[1]);
433: if (fd == -1) {
434: (void) close(fdin[0]);
435: /*
436: * fork again, to avoid blocking because both
437: * pipes filled
438: */
439: switch (fork()) {
440: case 0: /* child */
441: (void)close(fdout[0]);
442: if (swrite(fdin[1], old, n) != (ssize_t)n) {
443: #ifdef DEBUG
444: (void)fprintf(stderr,
445: "Write failed (%s)\n",
446: strerror(errno));
447: #endif
448: exit(1);
449: }
450: exit(0);
451: /*NOTREACHED*/
452:
453: case -1:
454: #ifdef DEBUG
455: (void)fprintf(stderr, "Fork failed (%s)\n",
456: strerror(errno));
457: #endif
458: exit(1);
459: /*NOTREACHED*/
460:
461: default: /* parent */
462: break;
463: }
464: (void) close(fdin[1]);
465: fdin[1] = -1;
466: }
467:
468: *newch = (unsigned char *) emalloc(HOWMANY + 1);
469:
470: if ((r = sread(fdout[0], *newch, HOWMANY, 0)) <= 0) {
471: #ifdef DEBUG
472: (void)fprintf(stderr, "Read failed (%s)\n",
473: strerror(errno));
474: #endif
475: efree(*newch);
476: n = 0;
477: newch[0] = '\0';
478: goto err;
479: } else {
480: n = r;
481: }
482: /* NUL terminate, as every buffer is handled here. */
483: (*newch)[n] = '\0';
484: err:
485: if (fdin[1] != -1)
486: (void) close(fdin[1]);
487: (void) close(fdout[0]);
488: #ifdef WNOHANG
489: while (waitpid(-1, NULL, WNOHANG) != -1)
490: continue;
491: #else
492: (void)wait(NULL);
493: #endif
494: (void) close(fdin[0]);
495:
496: return n;
497: }
498: }
499: #endif /* if PHP_FILEINFO_UNCOMPRESS */
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