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 "file.h"
36
37 #ifndef lint
38 FILE_RCSID("@(#)$File: compress.c,v 1.136 2022/09/13 16:08:34 christos Exp $")
39 #endif
40
41 #include "magic.h"
42 #include <stdlib.h>
43 #ifdef HAVE_UNISTD_H
44 #include <unistd.h>
45 #endif
46 #ifdef HAVE_SPAWN_H
47 #include <spawn.h>
48 #endif
49 #include <string.h>
50 #include <errno.h>
51 #include <ctype.h>
52 #include <stdarg.h>
53 #include <signal.h>
54 #ifndef HAVE_SIG_T
55 typedef void (*sig_t)(int);
56 #endif /* HAVE_SIG_T */
57 #ifdef HAVE_SYS_IOCTL_H
58 #include <sys/ioctl.h>
59 #endif
60 #ifdef HAVE_SYS_WAIT_H
61 #include <sys/wait.h>
62 #endif
63 #if defined(HAVE_SYS_TIME_H)
64 #include <sys/time.h>
65 #endif
66 #if defined(HAVE_ZLIB_H) && defined(PHP_FILEINFO_UNCOMPRESS)
67 #define BUILTIN_DECOMPRESS
68 #include <zlib.h>
69 #endif
70
71 #undef FIONREAD
72
73 #if defined(PHP_FILEINFO_UNCOMPRESS)
74 #define BUILTIN_BZLIB
75 #include <bzlib.h>
76 #endif
77
78 #if defined(HAVE_LZMA_H) && defined(XZLIBSUPPORT)
79 #define BUILTIN_XZLIB
80 #include <lzma.h>
81 #endif
82
83 #ifdef DEBUG
84 int tty = -1;
85 #define DPRINTF(...) do { \
86 if (tty == -1) \
87 tty = open("/dev/tty", O_RDWR); \
88 if (tty == -1) \
89 abort(); \
90 dprintf(tty, __VA_ARGS__); \
91 } while (/*CONSTCOND*/0)
92 #else
93 #define DPRINTF(...)
94 #endif
95
96 #ifdef ZLIBSUPPORT
97 /*
98 * The following python code is not really used because ZLIBSUPPORT is only
99 * defined if we have a built-in zlib, and the built-in zlib handles that.
100 * That is not true for android where we have zlib.h and not -lz.
101 */
102 static const char zlibcode[] =
103 "import sys, zlib; sys.stdout.write(zlib.decompress(sys.stdin.read()))";
104
105 static const char *zlib_args[] = { "python", "-c", zlibcode, NULL };
106
107 static int
zlibcmp(const unsigned char * buf)108 zlibcmp(const unsigned char *buf)
109 {
110 unsigned short x = 1;
111 unsigned char *s = CAST(unsigned char *, CAST(void *, &x));
112
113 if ((buf[0] & 0xf) != 8 || (buf[0] & 0x80) != 0)
114 return 0;
115 if (s[0] != 1) /* endianness test */
116 x = buf[0] | (buf[1] << 8);
117 else
118 x = buf[1] | (buf[0] << 8);
119 if (x % 31)
120 return 0;
121 return 1;
122 }
123 #endif
124
125 #ifdef PHP_FILEINFO_UNCOMPRESS
126
127 static int
lzmacmp(const unsigned char * buf)128 lzmacmp(const unsigned char *buf)
129 {
130 if (buf[0] != 0x5d || buf[1] || buf[2])
131 return 0;
132 if (buf[12] && buf[12] != 0xff)
133 return 0;
134 return 1;
135 }
136
137 #define gzip_flags "-cd"
138 #define lrzip_flags "-do"
139 #define lzip_flags gzip_flags
140
141 static const char *gzip_args[] = {
142 "gzip", gzip_flags, NULL
143 };
144 static const char *uncompress_args[] = {
145 "uncompress", "-c", NULL
146 };
147 static const char *bzip2_args[] = {
148 "bzip2", "-cd", NULL
149 };
150 static const char *lzip_args[] = {
151 "lzip", lzip_flags, NULL
152 };
153 static const char *xz_args[] = {
154 "xz", "-cd", NULL
155 };
156 static const char *lrzip_args[] = {
157 "lrzip", lrzip_flags, NULL
158 };
159 static const char *lz4_args[] = {
160 "lz4", "-cd", NULL
161 };
162 static const char *zstd_args[] = {
163 "zstd", "-cd", NULL
164 };
165
166 #define do_zlib NULL
167 #define do_bzlib NULL
168
169 private const struct {
170 union {
171 const char *magic;
172 int (*func)(const unsigned char *);
173 } u;
174 int maglen;
175 const char **argv;
176 void *unused;
177 } compr[] = {
178 #define METH_FROZEN 2
179 #define METH_BZIP 7
180 #define METH_XZ 9
181 #define METH_LZMA 13
182 #define METH_ZLIB 14
183 { { .magic = "\037\235" }, 2, gzip_args, NULL }, /* 0, compressed */
184 /* Uncompress can get stuck; so use gzip first if we have it
185 * Idea from Damien Clark, thanks! */
186 { { .magic = "\037\235" }, 2, uncompress_args, NULL },/* 1, compressed */
187 { { .magic = "\037\213" }, 2, gzip_args, do_zlib },/* 2, gzipped */
188 { { .magic = "\037\236" }, 2, gzip_args, NULL }, /* 3, frozen */
189 { { .magic = "\037\240" }, 2, gzip_args, NULL }, /* 4, SCO LZH */
190 /* the standard pack utilities do not accept standard input */
191 { { .magic = "\037\036" }, 2, gzip_args, NULL }, /* 5, packed */
192 { { .magic = "PK\3\4" }, 4, gzip_args, NULL }, /* 6, pkziped */
193 /* ...only first file examined */
194 { { .magic = "BZh" }, 3, bzip2_args, do_bzlib },/* 7, bzip2-ed */
195 { { .magic = "LZIP" }, 4, lzip_args, NULL }, /* 8, lzip-ed */
196 { { .magic = "\3757zXZ\0" },6, xz_args, NULL }, /* 9, XZ Util */
197 { { .magic = "LRZI" }, 4, lrzip_args, NULL }, /* 10, LRZIP */
198 { { .magic = "\004\"M\030" },4, lz4_args, NULL }, /* 11, LZ4 */
199 { { .magic = "\x28\xB5\x2F\xFD" }, 4, zstd_args, NULL },/* 12, zstd */
200 { { .func = lzmacmp }, -13, xz_args, NULL }, /* 13, lzma */
201 #ifdef ZLIBSUPPORT
202 { { .func = zlibcmp }, -2, zlib_args, NULL }, /* 14, zlib */
203 #endif
204 };
205
206 #define OKDATA 0
207 #define NODATA 1
208 #define ERRDATA 2
209
210 private ssize_t swrite(int, const void *, size_t);
211 #if HAVE_FORK
212 private size_t ncompr = __arraycount(compr);
213 private int uncompressbuf(int, size_t, size_t, const unsigned char *,
214 unsigned char **, size_t *);
215 #ifdef BUILTIN_DECOMPRESS
216 private int uncompresszlib(const unsigned char *, unsigned char **, size_t,
217 size_t *, int);
218 private int uncompressgzipped(const unsigned char *, unsigned char **, size_t,
219 size_t *);
220 #endif
221 #ifdef BUILTIN_BZLIB
222 private int uncompressbzlib(const unsigned char *, unsigned char **, size_t,
223 size_t *);
224 #endif
225 #ifdef BUILTIN_XZLIB
226 private int uncompressxzlib(const unsigned char *, unsigned char **, size_t,
227 size_t *);
228 #endif
229
230 static int makeerror(unsigned char **, size_t *, const char *, ...)
231 __attribute__((__format__(__printf__, 3, 4)));
232 private const char *methodname(size_t);
233
234 private int
format_decompression_error(struct magic_set * ms,size_t i,unsigned char * buf)235 format_decompression_error(struct magic_set *ms, size_t i, unsigned char *buf)
236 {
237 unsigned char *p;
238 int mime = ms->flags & MAGIC_MIME;
239
240 if (!mime)
241 return file_printf(ms, "ERROR:[%s: %s]", methodname(i), buf);
242
243 for (p = buf; *p; p++)
244 if (!isalnum(*p))
245 *p = '-';
246
247 return file_printf(ms, "application/x-decompression-error-%s-%s",
248 methodname(i), buf);
249 }
250
251 protected int
file_zmagic(struct magic_set * ms,const struct buffer * b,const char * name)252 file_zmagic(struct magic_set *ms, const struct buffer *b, const char *name)
253 {
254 unsigned char *newbuf = NULL;
255 size_t i, nsz;
256 char *rbuf;
257 file_pushbuf_t *pb;
258 int urv, prv, rv = 0;
259 int mime = ms->flags & MAGIC_MIME;
260 int fd = b->fd;
261 const unsigned char *buf = CAST(const unsigned char *, b->fbuf);
262 size_t nbytes = b->flen;
263 int sa_saved = 0;
264 struct sigaction sig_act;
265
266 if ((ms->flags & MAGIC_COMPRESS) == 0)
267 return 0;
268
269 for (i = 0; i < ncompr; i++) {
270 int zm;
271 if (nbytes < CAST(size_t, abs(compr[i].maglen)))
272 continue;
273 if (compr[i].maglen < 0) {
274 zm = (*compr[i].u.func)(buf);
275 } else {
276 zm = memcmp(buf, compr[i].u.magic,
277 CAST(size_t, compr[i].maglen)) == 0;
278 }
279
280 if (!zm)
281 continue;
282
283 /* Prevent SIGPIPE death if child dies unexpectedly */
284 if (!sa_saved) {
285 //We can use sig_act for both new and old, but
286 struct sigaction new_act;
287 memset(&new_act, 0, sizeof(new_act));
288 new_act.sa_handler = SIG_IGN;
289 sa_saved = sigaction(SIGPIPE, &new_act, &sig_act) != -1;
290 }
291
292 nsz = nbytes;
293 urv = uncompressbuf(fd, ms->bytes_max, i, buf, &newbuf, &nsz);
294 DPRINTF("uncompressbuf = %d, %s, %" SIZE_T_FORMAT "u\n", urv,
295 (char *)newbuf, nsz);
296 switch (urv) {
297 case OKDATA:
298 case ERRDATA:
299 ms->flags &= ~MAGIC_COMPRESS;
300 if (urv == ERRDATA)
301 prv = format_decompression_error(ms, i, newbuf);
302 else
303 prv = file_buffer(ms, NULL, NULL, name, newbuf, nsz);
304 if (prv == -1)
305 goto error;
306 rv = 1;
307 if ((ms->flags & MAGIC_COMPRESS_TRANSP) != 0)
308 goto out;
309 if (mime != MAGIC_MIME && mime != 0)
310 goto out;
311 if ((file_printf(ms,
312 mime ? " compressed-encoding=" : " (")) == -1)
313 goto error;
314 if ((pb = file_push_buffer(ms)) == NULL)
315 goto error;
316 /*
317 * XXX: If file_buffer fails here, we overwrite
318 * the compressed text. FIXME.
319 */
320 if (file_buffer(ms, NULL, NULL, NULL, buf, nbytes) == -1) {
321 if (file_pop_buffer(ms, pb) != NULL)
322 abort();
323 goto error;
324 }
325 if ((rbuf = file_pop_buffer(ms, pb)) != NULL) {
326 if (file_printf(ms, "%s", rbuf) == -1) {
327 efree(rbuf);
328 goto error;
329 }
330 efree(rbuf);
331 }
332 if (!mime && file_printf(ms, ")") == -1)
333 goto error;
334 /*FALLTHROUGH*/
335 case NODATA:
336 break;
337 default:
338 abort();
339 /*NOTREACHED*/
340 error:
341 rv = -1;
342 break;
343 }
344 }
345 out:
346 DPRINTF("rv = %d\n", rv);
347
348 if (sa_saved && sig_act.sa_handler != SIG_IGN)
349 (void)sigaction(SIGPIPE, &sig_act, NULL);
350
351 if (newbuf)
352 efree(newbuf);
353 ms->flags |= MAGIC_COMPRESS;
354 DPRINTF("Zmagic returns %d\n", rv);
355 return rv;
356 }
357 #endif
358 /*
359 * `safe' write for sockets and pipes.
360 */
361 private ssize_t
swrite(int fd,const void * buf,size_t n)362 swrite(int fd, const void *buf, size_t n)
363 {
364 ssize_t rv;
365 size_t rn = n;
366
367 do
368 switch (rv = write(fd, buf, n)) {
369 case -1:
370 if (errno == EINTR)
371 continue;
372 return -1;
373 default:
374 n -= rv;
375 buf = CAST(const char *, buf) + rv;
376 break;
377 }
378 while (n > 0);
379 return rn;
380 }
381
382
383 /*
384 * `safe' read for sockets and pipes.
385 */
386 protected ssize_t
sread(int fd,void * buf,size_t n,int canbepipe)387 sread(int fd, void *buf, size_t n, int canbepipe __attribute__((__unused__)))
388 {
389 ssize_t rv;
390 #ifdef FIONREAD
391 int t = 0;
392 #endif
393 size_t rn = n;
394
395 if (fd == STDIN_FILENO)
396 goto nocheck;
397
398 #ifdef FIONREAD
399 if (canbepipe && (ioctl(fd, FIONREAD, &t) == -1 || t == 0)) {
400 #ifdef FD_ZERO
401 ssize_t cnt;
402 for (cnt = 0;; cnt++) {
403 fd_set check;
404 struct timeval tout = {0, 100 * 1000};
405 int selrv;
406
407 FD_ZERO(&check);
408 FD_SET(fd, &check);
409
410 /*
411 * Avoid soft deadlock: do not read if there
412 * is nothing to read from sockets and pipes.
413 */
414 selrv = select(fd + 1, &check, NULL, NULL, &tout);
415 if (selrv == -1) {
416 if (errno == EINTR || errno == EAGAIN)
417 continue;
418 } else if (selrv == 0 && cnt >= 5) {
419 return 0;
420 } else
421 break;
422 }
423 #endif
424 (void)ioctl(fd, FIONREAD, &t);
425 }
426
427 if (t > 0 && CAST(size_t, t) < n) {
428 n = t;
429 rn = n;
430 }
431 #endif
432
433 nocheck:
434 do
435 switch ((rv = FINFO_READ_FUNC(fd, buf, n))) {
436 case -1:
437 if (errno == EINTR)
438 continue;
439 return -1;
440 case 0:
441 return rn - n;
442 default:
443 n -= rv;
444 buf = CAST(char *, CCAST(void *, buf)) + rv;
445 break;
446 }
447 while (n > 0);
448 return rn;
449 }
450
451 protected int
file_pipe2file(struct magic_set * ms,int fd,const void * startbuf,size_t nbytes)452 file_pipe2file(struct magic_set *ms, int fd, const void *startbuf,
453 size_t nbytes)
454 {
455 char buf[4096];
456 ssize_t r;
457 int tfd;
458
459 #ifdef WIN32
460 const char *t;
461 buf[0] = '\0';
462 if ((t = getenv("TEMP")) != NULL)
463 (void)strlcpy(buf, t, sizeof(buf));
464 else if ((t = getenv("TMP")) != NULL)
465 (void)strlcpy(buf, t, sizeof(buf));
466 else if ((t = getenv("TMPDIR")) != NULL)
467 (void)strlcpy(buf, t, sizeof(buf));
468 if (buf[0] != '\0')
469 (void)strlcat(buf, "/", sizeof(buf));
470 (void)strlcat(buf, "file.XXXXXX", sizeof(buf));
471 #else
472 (void)strlcpy(buf, "/tmp/file.XXXXXX", sizeof(buf));
473 #endif
474 #ifndef HAVE_MKSTEMP
475 {
476 char *ptr = mktemp(buf);
477 tfd = open(ptr, O_RDWR|O_TRUNC|O_EXCL|O_CREAT, 0600);
478 r = errno;
479 (void)unlink(ptr);
480 errno = r;
481 }
482 #else
483 {
484 int te;
485 mode_t ou = umask(0);
486 tfd = mkstemp(buf);
487 (void)umask(ou);
488 te = errno;
489 (void)unlink(buf);
490 errno = te;
491 }
492 #endif
493 if (tfd == -1) {
494 file_error(ms, errno,
495 "cannot create temporary file for pipe copy");
496 return -1;
497 }
498
499 if (swrite(tfd, startbuf, nbytes) != CAST(ssize_t, nbytes))
500 r = 1;
501 else {
502 while ((r = sread(fd, buf, sizeof(buf), 1)) > 0)
503 if (swrite(tfd, buf, CAST(size_t, r)) != r)
504 break;
505 }
506
507 switch (r) {
508 case -1:
509 file_error(ms, errno, "error copying from pipe to temp file");
510 return -1;
511 case 0:
512 break;
513 default:
514 file_error(ms, errno, "error while writing to temp file");
515 return -1;
516 }
517
518 /*
519 * We duplicate the file descriptor, because fclose on a
520 * tmpfile will delete the file, but any open descriptors
521 * can still access the phantom inode.
522 */
523 if ((fd = dup2(tfd, fd)) == -1) {
524 file_error(ms, errno, "could not dup descriptor for temp file");
525 return -1;
526 }
527 (void)close(tfd);
528 if (FINFO_LSEEK_FUNC(fd, (zend_off_t)0, SEEK_SET) == (zend_off_t)-1) {
529 file_badseek(ms);
530 return -1;
531 }
532 return fd;
533 }
534 #ifdef PHP_FILEINFO_UNCOMPRESS
535 #ifdef BUILTIN_DECOMPRESS
536
537 #define FHCRC (1 << 1)
538 #define FEXTRA (1 << 2)
539 #define FNAME (1 << 3)
540 #define FCOMMENT (1 << 4)
541
542
543 private int
uncompressgzipped(const unsigned char * old,unsigned char ** newch,size_t bytes_max,size_t * n)544 uncompressgzipped(const unsigned char *old, unsigned char **newch,
545 size_t bytes_max, size_t *n)
546 {
547 unsigned char flg = old[3];
548 size_t data_start = 10;
549
550 if (flg & FEXTRA) {
551 if (data_start + 1 >= *n)
552 goto err;
553 data_start += 2 + old[data_start] + old[data_start + 1] * 256;
554 }
555 if (flg & FNAME) {
556 while(data_start < *n && old[data_start])
557 data_start++;
558 data_start++;
559 }
560 if (flg & FCOMMENT) {
561 while(data_start < *n && old[data_start])
562 data_start++;
563 data_start++;
564 }
565 if (flg & FHCRC)
566 data_start += 2;
567
568 if (data_start >= *n)
569 goto err;
570
571 *n -= data_start;
572 old += data_start;
573 return uncompresszlib(old, newch, bytes_max, n, 0);
574 err:
575 return makeerror(newch, n, "File too short");
576 }
577
578 private int
uncompresszlib(const unsigned char * old,unsigned char ** newch,size_t bytes_max,size_t * n,int zlib)579 uncompresszlib(const unsigned char *old, unsigned char **newch,
580 size_t bytes_max, size_t *n, int zlib)
581 {
582 int rc;
583 z_stream z;
584
585 if ((*newch = CAST(unsigned char *, emalloc(bytes_max + 1))) == NULL)
586 return makeerror(newch, n, "No buffer, %s", strerror(errno));
587
588 z.next_in = CCAST(Bytef *, old);
589 z.avail_in = CAST(uint32_t, *n);
590 z.next_out = *newch;
591 z.avail_out = CAST(unsigned int, bytes_max);
592 z.zalloc = Z_NULL;
593 z.zfree = Z_NULL;
594 z.opaque = Z_NULL;
595
596 /* LINTED bug in header macro */
597 rc = zlib ? inflateInit(&z) : inflateInit2(&z, -15);
598 if (rc != Z_OK)
599 goto err;
600
601 rc = inflate(&z, Z_SYNC_FLUSH);
602 if (rc != Z_OK && rc != Z_STREAM_END)
603 goto err;
604
605 *n = CAST(size_t, z.total_out);
606 rc = inflateEnd(&z);
607 if (rc != Z_OK)
608 goto err;
609
610 /* let's keep the nul-terminate tradition */
611 (*newch)[*n] = '\0';
612
613 return OKDATA;
614 err:
615 strlcpy(RCAST(char *, *newch), z.msg ? z.msg : zError(rc), bytes_max);
616 *n = strlen(RCAST(char *, *newch));
617 return ERRDATA;
618 }
619 #endif
620
621 #ifdef BUILTIN_BZLIB
622 private int
uncompressbzlib(const unsigned char * old,unsigned char ** newch,size_t bytes_max,size_t * n)623 uncompressbzlib(const unsigned char *old, unsigned char **newch,
624 size_t bytes_max, size_t *n)
625 {
626 int rc;
627 bz_stream bz;
628
629 memset(&bz, 0, sizeof(bz));
630 rc = BZ2_bzDecompressInit(&bz, 0, 0);
631 if (rc != BZ_OK)
632 goto err;
633
634 if ((*newch = CAST(unsigned char *, malloc(bytes_max + 1))) == NULL)
635 return makeerror(newch, n, "No buffer, %s", strerror(errno));
636
637 bz.next_in = CCAST(char *, RCAST(const char *, old));
638 bz.avail_in = CAST(uint32_t, *n);
639 bz.next_out = RCAST(char *, *newch);
640 bz.avail_out = CAST(unsigned int, bytes_max);
641
642 rc = BZ2_bzDecompress(&bz);
643 if (rc != BZ_OK && rc != BZ_STREAM_END)
644 goto err;
645
646 /* Assume byte_max is within 32bit */
647 /* assert(bz.total_out_hi32 == 0); */
648 *n = CAST(size_t, bz.total_out_lo32);
649 rc = BZ2_bzDecompressEnd(&bz);
650 if (rc != BZ_OK)
651 goto err;
652
653 /* let's keep the nul-terminate tradition */
654 (*newch)[*n] = '\0';
655
656 return OKDATA;
657 err:
658 snprintf(RCAST(char *, *newch), bytes_max, "bunzip error %d", rc);
659 *n = strlen(RCAST(char *, *newch));
660 return ERRDATA;
661 }
662 #endif
663
664 #ifdef BUILTIN_XZLIB
665 private int
uncompressxzlib(const unsigned char * old,unsigned char ** newch,size_t bytes_max,size_t * n)666 uncompressxzlib(const unsigned char *old, unsigned char **newch,
667 size_t bytes_max, size_t *n)
668 {
669 int rc;
670 lzma_stream xz;
671
672 memset(&xz, 0, sizeof(xz));
673 rc = lzma_auto_decoder(&xz, UINT64_MAX, 0);
674 if (rc != LZMA_OK)
675 goto err;
676
677 if ((*newch = CAST(unsigned char *, malloc(bytes_max + 1))) == NULL)
678 return makeerror(newch, n, "No buffer, %s", strerror(errno));
679
680 xz.next_in = CCAST(const uint8_t *, old);
681 xz.avail_in = CAST(uint32_t, *n);
682 xz.next_out = RCAST(uint8_t *, *newch);
683 xz.avail_out = CAST(unsigned int, bytes_max);
684
685 rc = lzma_code(&xz, LZMA_RUN);
686 if (rc != LZMA_OK && rc != LZMA_STREAM_END)
687 goto err;
688
689 *n = CAST(size_t, xz.total_out);
690
691 lzma_end(&xz);
692
693 /* let's keep the nul-terminate tradition */
694 (*newch)[*n] = '\0';
695
696 return OKDATA;
697 err:
698 snprintf(RCAST(char *, *newch), bytes_max, "unxz error %d", rc);
699 *n = strlen(RCAST(char *, *newch));
700 return ERRDATA;
701 }
702 #endif
703
704
705 static int
makeerror(unsigned char ** buf,size_t * len,const char * fmt,...)706 makeerror(unsigned char **buf, size_t *len, const char *fmt, ...)
707 {
708 char *msg;
709 va_list ap;
710 int rv;
711
712 va_start(ap, fmt);
713 rv = vasprintf(&msg, fmt, ap);
714 va_end(ap);
715 if (rv < 0) {
716 *buf = NULL;
717 *len = 0;
718 return NODATA;
719 }
720 *buf = RCAST(unsigned char *, msg);
721 *len = strlen(msg);
722 return ERRDATA;
723 }
724
725 static void
closefd(int * fd,size_t i)726 closefd(int *fd, size_t i)
727 {
728 if (fd[i] == -1)
729 return;
730 (void) close(fd[i]);
731 fd[i] = -1;
732 }
733
734 static void
closep(int * fd)735 closep(int *fd)
736 {
737 size_t i;
738 for (i = 0; i < 2; i++)
739 closefd(fd, i);
740 }
741
742 static void
movedesc(void * v,int i,int fd)743 movedesc(void *v, int i, int fd)
744 {
745 if (fd == i)
746 return; /* "no dup was necessary" */
747 #ifdef HAVE_POSIX_SPAWNP
748 posix_spawn_file_actions_t *fa = RCAST(posix_spawn_file_actions_t *, v);
749 posix_spawn_file_actions_adddup2(fa, fd, i);
750 posix_spawn_file_actions_addclose(fa, fd);
751 #else
752 if (dup2(fd, i) == -1) {
753 DPRINTF("dup(%d, %d) failed (%s)\n", fd, i, strerror(errno));
754 exit(1);
755 }
756 close(v ? fd : fd);
757 #endif
758 }
759
760 static void
closedesc(void * v,int fd)761 closedesc(void *v, int fd)
762 {
763 #ifdef HAVE_POSIX_SPAWNP
764 posix_spawn_file_actions_t *fa = RCAST(posix_spawn_file_actions_t *, v);
765 posix_spawn_file_actions_addclose(fa, fd);
766 #else
767 close(v ? fd : fd);
768 #endif
769 }
770
771 static void
handledesc(void * v,int fd,int fdp[3][2])772 handledesc(void *v, int fd, int fdp[3][2])
773 {
774 if (fd != -1) {
775 (void) lseek(fd, CAST(off_t, 0), SEEK_SET);
776 movedesc(v, STDIN_FILENO, fd);
777 } else {
778 movedesc(v, STDIN_FILENO, fdp[STDIN_FILENO][0]);
779 if (fdp[STDIN_FILENO][1] > 2)
780 closedesc(v, fdp[STDIN_FILENO][1]);
781 }
782
783 file_clear_closexec(STDIN_FILENO);
784
785 ///FIXME: if one of the fdp[i][j] is 0 or 1, this can bomb spectacularly
786 movedesc(v, STDOUT_FILENO, fdp[STDOUT_FILENO][1]);
787 if (fdp[STDOUT_FILENO][0] > 2)
788 closedesc(v, fdp[STDOUT_FILENO][0]);
789
790 file_clear_closexec(STDOUT_FILENO);
791
792 movedesc(v, STDERR_FILENO, fdp[STDERR_FILENO][1]);
793 if (fdp[STDERR_FILENO][0] > 2)
794 closedesc(v, fdp[STDERR_FILENO][0]);
795
796 file_clear_closexec(STDERR_FILENO);
797 }
798
799 static pid_t
writechild(int fd,const void * old,size_t n)800 writechild(int fd, const void *old, size_t n)
801 {
802 pid_t pid;
803
804 /*
805 * fork again, to avoid blocking because both
806 * pipes filled
807 */
808 pid = fork();
809 if (pid == -1) {
810 DPRINTF("Fork failed (%s)\n", strerror(errno));
811 exit(1);
812 }
813 if (pid == 0) {
814 /* child */
815 if (swrite(fd, old, n) != CAST(ssize_t, n)) {
816 DPRINTF("Write failed (%s)\n", strerror(errno));
817 exit(1);
818 }
819 exit(0);
820 }
821 /* parent */
822 return pid;
823 }
824
825 static ssize_t
filter_error(unsigned char * ubuf,ssize_t n)826 filter_error(unsigned char *ubuf, ssize_t n)
827 {
828 char *p;
829 char *buf;
830
831 ubuf[n] = '\0';
832 buf = RCAST(char *, ubuf);
833 while (isspace(CAST(unsigned char, *buf)))
834 buf++;
835 DPRINTF("Filter error[[[%s]]]\n", buf);
836 if ((p = strchr(CAST(char *, buf), '\n')) != NULL)
837 *p = '\0';
838 if ((p = strchr(CAST(char *, buf), ';')) != NULL)
839 *p = '\0';
840 if ((p = strrchr(CAST(char *, buf), ':')) != NULL) {
841 ++p;
842 while (isspace(CAST(unsigned char, *p)))
843 p++;
844 n = strlen(p);
845 memmove(ubuf, p, CAST(size_t, n + 1));
846 }
847 DPRINTF("Filter error after[[[%s]]]\n", (char *)ubuf);
848 if (islower(*ubuf))
849 *ubuf = toupper(*ubuf);
850 return n;
851 }
852
853 private const char *
methodname(size_t method)854 methodname(size_t method)
855 {
856 switch (method) {
857 #ifdef BUILTIN_DECOMPRESS
858 case METH_FROZEN:
859 case METH_ZLIB:
860 return "zlib";
861 #endif
862 #ifdef BUILTIN_BZLIB
863 case METH_BZIP:
864 return "bzlib";
865 #endif
866 #ifdef BUILTIN_XZLIB
867 case METH_XZ:
868 case METH_LZMA:
869 return "xzlib";
870 #endif
871 default:
872 return compr[method].argv[0];
873 }
874 }
875
876 private int
uncompressbuf(int fd,size_t bytes_max,size_t method,const unsigned char * old,unsigned char ** newch,size_t * n)877 uncompressbuf(int fd, size_t bytes_max, size_t method, const unsigned char *old,
878 unsigned char **newch, size_t* n)
879 {
880 int fdp[3][2];
881 int status, rv, w;
882 pid_t pid;
883 pid_t writepid = -1;
884 size_t i;
885 ssize_t r;
886 char *const *args;
887 #ifdef HAVE_POSIX_SPAWNP
888 posix_spawn_file_actions_t fa;
889 #endif
890
891 switch (method) {
892 #ifdef BUILTIN_DECOMPRESS
893 case METH_FROZEN:
894 return uncompressgzipped(old, newch, bytes_max, n);
895 case METH_ZLIB:
896 return uncompresszlib(old, newch, bytes_max, n, 1);
897 #endif
898 #ifdef BUILTIN_BZLIB
899 case METH_BZIP:
900 return uncompressbzlib(old, newch, bytes_max, n);
901 #endif
902 #ifdef BUILTIN_XZLIB
903 case METH_XZ:
904 case METH_LZMA:
905 return uncompressxzlib(old, newch, bytes_max, n);
906 #endif
907 default:
908 break;
909 }
910
911 (void)fflush(stdout);
912 (void)fflush(stderr);
913
914 for (i = 0; i < __arraycount(fdp); i++)
915 fdp[i][0] = fdp[i][1] = -1;
916
917 /*
918 * There are multithreaded users who run magic_file()
919 * from dozens of threads. If two parallel magic_file() calls
920 * analyze two large compressed files, both will spawn
921 * an uncompressing child here, which writes out uncompressed data.
922 * We read some portion, then close the pipe, then waitpid() the child.
923 * If uncompressed data is larger, child shound get EPIPE and exit.
924 * However, with *parallel* calls OTHER child may unintentionally
925 * inherit pipe fds, thus keeping pipe open and making writes in
926 * our child block instead of failing with EPIPE!
927 * (For the bug to occur, two threads must mutually inherit their pipes,
928 * and both must have large outputs. Thus it happens not that often).
929 * To avoid this, be sure to create pipes with O_CLOEXEC.
930 */
931 if ((fd == -1 && file_pipe_closexec(fdp[STDIN_FILENO]) == -1) ||
932 file_pipe_closexec(fdp[STDOUT_FILENO]) == -1 ||
933 file_pipe_closexec(fdp[STDERR_FILENO]) == -1) {
934 closep(fdp[STDIN_FILENO]);
935 closep(fdp[STDOUT_FILENO]);
936 return makeerror(newch, n, "Cannot create pipe, %s",
937 strerror(errno));
938 }
939
940 args = RCAST(char *const *, RCAST(intptr_t, compr[method].argv));
941 #ifdef HAVE_POSIX_SPAWNP
942 posix_spawn_file_actions_init(&fa);
943
944 handledesc(&fa, fd, fdp);
945
946 status = posix_spawnp(&pid, compr[method].argv[0], &fa, NULL,
947 args, NULL);
948
949 posix_spawn_file_actions_destroy(&fa);
950
951 if (status == -1) {
952 return makeerror(newch, n, "Cannot posix_spawn `%s', %s",
953 compr[method].argv[0], strerror(errno));
954 }
955 #else
956 /* For processes with large mapped virtual sizes, vfork
957 * may be _much_ faster (10-100 times) than fork.
958 */
959 pid = vfork();
960 if (pid == -1) {
961 return makeerror(newch, n, "Cannot vfork, %s",
962 strerror(errno));
963 }
964 if (pid == 0) {
965 /* child */
966 /* Note: we are after vfork, do not modify memory
967 * in a way which confuses parent. In particular,
968 * do not modify fdp[i][j].
969 */
970 handledesc(NULL, fd, fdp);
971
972 (void)execvp(compr[method].argv[0], args);
973 dprintf(STDERR_FILENO, "exec `%s' failed, %s",
974 compr[method].argv[0], strerror(errno));
975 _exit(1); /* _exit(), not exit(), because of vfork */
976 }
977 #endif
978 /* parent */
979 /* Close write sides of child stdout/err pipes */
980 for (i = 1; i < __arraycount(fdp); i++)
981 closefd(fdp[i], 1);
982 /* Write the buffer data to child stdin, if we don't have fd */
983 if (fd == -1) {
984 closefd(fdp[STDIN_FILENO], 0);
985 writepid = writechild(fdp[STDIN_FILENO][1], old, *n);
986 closefd(fdp[STDIN_FILENO], 1);
987 }
988
989 *newch = CAST(unsigned char *, malloc(bytes_max + 1));
990 if (*newch == NULL) {
991 rv = makeerror(newch, n, "No buffer, %s",
992 strerror(errno));
993 goto err;
994 }
995 rv = OKDATA;
996 errno = 0;
997 r = sread(fdp[STDOUT_FILENO][0], *newch, bytes_max, 0);
998 if (r == 0 && errno == 0)
999 goto ok;
1000 if (r <= 0) {
1001 DPRINTF("Read stdout failed %d (%s)\n", fdp[STDOUT_FILENO][0],
1002 r != -1 ? strerror(errno) : "no data");
1003
1004 rv = ERRDATA;
1005 if (r == 0 &&
1006 (r = sread(fdp[STDERR_FILENO][0], *newch, bytes_max, 0)) > 0)
1007 {
1008 r = filter_error(*newch, r);
1009 goto ok;
1010 }
1011 free(*newch);
1012 if (r == 0)
1013 rv = makeerror(newch, n, "Read failed, %s",
1014 strerror(errno));
1015 else
1016 rv = makeerror(newch, n, "No data");
1017 goto err;
1018 }
1019 ok:
1020 *n = r;
1021 /* NUL terminate, as every buffer is handled here. */
1022 (*newch)[*n] = '\0';
1023 err:
1024 closefd(fdp[STDIN_FILENO], 1);
1025 closefd(fdp[STDOUT_FILENO], 0);
1026 closefd(fdp[STDERR_FILENO], 0);
1027
1028 w = waitpid(pid, &status, 0);
1029 wait_err:
1030 if (w == -1) {
1031 free(*newch);
1032 rv = makeerror(newch, n, "Wait failed, %s", strerror(errno));
1033 DPRINTF("Child wait return %#x\n", status);
1034 } else if (!WIFEXITED(status)) {
1035 DPRINTF("Child not exited (%#x)\n", status);
1036 } else if (WEXITSTATUS(status) != 0) {
1037 DPRINTF("Child exited (%#x)\n", WEXITSTATUS(status));
1038 }
1039 if (writepid > 0) {
1040 /* _After_ we know decompressor has exited, our input writer
1041 * definitely will exit now (at worst, writing fails in it,
1042 * since output fd is closed now on the reading size).
1043 */
1044 w = waitpid(writepid, &status, 0);
1045 writepid = -1;
1046 goto wait_err;
1047 }
1048
1049 closefd(fdp[STDIN_FILENO], 0); //why? it is already closed here!
1050 DPRINTF("Returning %p n=%" SIZE_T_FORMAT "u rv=%d\n", *newch, *n, rv);
1051
1052 return rv;
1053 }
1054 #endif
1055 #endif
1056
