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 1.127 2020/05/31 00:11:06 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 #include <string.h>
47 #include <errno.h>
48 #include <ctype.h>
49 #include <stdarg.h>
50 #include <signal.h>
51 #ifndef HAVE_SIG_T
52 typedef void (*sig_t)(int);
53 #endif /* HAVE_SIG_T */
54 #if !defined(__MINGW32__) && !defined(WIN32) && !defined(__MINGW64__)
55 #include <sys/ioctl.h>
56 #endif
57 #ifdef HAVE_SYS_WAIT_H
58 #include <sys/wait.h>
59 #endif
60 #if defined(HAVE_SYS_TIME_H)
61 #include <sys/time.h>
62 #endif
63
64 #if defined(HAVE_ZLIB_H) && defined(ZLIBSUPPORT)
65 #define BUILTIN_DECOMPRESS
66 #include <zlib.h>
67 #endif
68
69 #if defined(HAVE_BZLIB_H) && defined(BZLIBSUPPORT)
70 #define BUILTIN_BZLIB
71 #include <bzlib.h>
72 #endif
73
74 #if defined(HAVE_XZLIB_H) && defined(XZLIBSUPPORT)
75 #define BUILTIN_XZLIB
76 #include <lzma.h>
77 #endif
78
79 #ifdef DEBUG
80 int tty = -1;
81 #define DPRINTF(...) do { \
82 if (tty == -1) \
83 tty = open("/dev/tty", O_RDWR); \
84 if (tty == -1) \
85 abort(); \
86 dprintf(tty, __VA_ARGS__); \
87 } while (/*CONSTCOND*/0)
88 #else
89 #define DPRINTF(...)
90 #endif
91
92 #ifdef ZLIBSUPPORT
93 /*
94 * The following python code is not really used because ZLIBSUPPORT is only
95 * defined if we have a built-in zlib, and the built-in zlib handles that.
96 * That is not true for android where we have zlib.h and not -lz.
97 */
98 static const char zlibcode[] =
99 "import sys, zlib; sys.stdout.write(zlib.decompress(sys.stdin.read()))";
100
101 static const char *zlib_args[] = { "python", "-c", zlibcode, NULL };
102
103 static int
zlibcmp(const unsigned char * buf)104 zlibcmp(const unsigned char *buf)
105 {
106 unsigned short x = 1;
107 unsigned char *s = CAST(unsigned char *, CAST(void *, &x));
108
109 if ((buf[0] & 0xf) != 8 || (buf[0] & 0x80) != 0)
110 return 0;
111 if (s[0] != 1) /* endianness test */
112 x = buf[0] | (buf[1] << 8);
113 else
114 x = buf[1] | (buf[0] << 8);
115 if (x % 31)
116 return 0;
117 return 1;
118 }
119 #endif
120
121 static int
lzmacmp(const unsigned char * buf)122 lzmacmp(const unsigned char *buf)
123 {
124 if (buf[0] != 0x5d || buf[1] || buf[2])
125 return 0;
126 if (buf[12] && buf[12] != 0xff)
127 return 0;
128 return 1;
129 }
130
131 #define gzip_flags "-cd"
132 #define lrzip_flags "-do"
133 #define lzip_flags gzip_flags
134
135 static const char *gzip_args[] = {
136 "gzip", gzip_flags, NULL
137 };
138 static const char *uncompress_args[] = {
139 "uncompress", "-c", NULL
140 };
141 static const char *bzip2_args[] = {
142 "bzip2", "-cd", NULL
143 };
144 static const char *lzip_args[] = {
145 "lzip", lzip_flags, NULL
146 };
147 static const char *xz_args[] = {
148 "xz", "-cd", NULL
149 };
150 static const char *lrzip_args[] = {
151 "lrzip", lrzip_flags, NULL
152 };
153 static const char *lz4_args[] = {
154 "lz4", "-cd", NULL
155 };
156 static const char *zstd_args[] = {
157 "zstd", "-cd", NULL
158 };
159
160 #define do_zlib NULL
161 #define do_bzlib NULL
162
163 private const struct {
164 union {
165 const char *magic;
166 int (*func)(const unsigned char *);
167 } u;
168 int maglen;
169 const char **argv;
170 void *unused;
171 } compr[] = {
172 #define METH_FROZEN 2
173 #define METH_BZIP 7
174 #define METH_XZ 9
175 #define METH_LZMA 13
176 #define METH_ZLIB 14
177 { { .magic = "\037\235" }, 2, gzip_args, NULL }, /* 0, compressed */
178 /* Uncompress can get stuck; so use gzip first if we have it
179 * Idea from Damien Clark, thanks! */
180 { { .magic = "\037\235" }, 2, uncompress_args, NULL },/* 1, compressed */
181 { { .magic = "\037\213" }, 2, gzip_args, do_zlib },/* 2, gzipped */
182 { { .magic = "\037\236" }, 2, gzip_args, NULL }, /* 3, frozen */
183 { { .magic = "\037\240" }, 2, gzip_args, NULL }, /* 4, SCO LZH */
184 /* the standard pack utilities do not accept standard input */
185 { { .magic = "\037\036" }, 2, gzip_args, NULL }, /* 5, packed */
186 { { .magic = "PK\3\4" }, 4, gzip_args, NULL }, /* 6, pkziped */
187 /* ...only first file examined */
188 { { .magic = "BZh" }, 3, bzip2_args, do_bzlib },/* 7, bzip2-ed */
189 { { .magic = "LZIP" }, 4, lzip_args, NULL }, /* 8, lzip-ed */
190 { { .magic = "\3757zXZ\0" },6, xz_args, NULL }, /* 9, XZ Util */
191 { { .magic = "LRZI" }, 4, lrzip_args, NULL }, /* 10, LRZIP */
192 { { .magic = "\004\"M\030" },4, lz4_args, NULL }, /* 11, LZ4 */
193 { { .magic = "\x28\xB5\x2F\xFD" }, 4, zstd_args, NULL },/* 12, zstd */
194 { { .func = lzmacmp }, -13, xz_args, NULL }, /* 13, lzma */
195 #ifdef ZLIBSUPPORT
196 { { .func = zlibcmp }, -2, zlib_args, NULL }, /* 14, zlib */
197 #endif
198 };
199
200 #define OKDATA 0
201 #define NODATA 1
202 #define ERRDATA 2
203
204 private ssize_t swrite(int, const void *, size_t);
205 #if HAVE_FORK
206 private size_t ncompr = __arraycount(compr);
207 private int uncompressbuf(int, size_t, size_t, const unsigned char *,
208 unsigned char **, size_t *);
209 #ifdef BUILTIN_DECOMPRESS
210 private int uncompresszlib(const unsigned char *, unsigned char **, size_t,
211 size_t *, int);
212 private int uncompressgzipped(const unsigned char *, unsigned char **, size_t,
213 size_t *);
214 #endif
215 #ifdef BUILTIN_BZLIB
216 private int uncompressbzlib(const unsigned char *, unsigned char **, size_t,
217 size_t *);
218 #endif
219 #ifdef BUILTIN_XZLIB
220 private int uncompressxzlib(const unsigned char *, unsigned char **, size_t,
221 size_t *);
222 #endif
223
224 static int makeerror(unsigned char **, size_t *, const char *, ...)
225 __attribute__((__format__(__printf__, 3, 4)));
226 private const char *methodname(size_t);
227
228 private int
format_decompression_error(struct magic_set * ms,size_t i,unsigned char * buf)229 format_decompression_error(struct magic_set *ms, size_t i, unsigned char *buf)
230 {
231 unsigned char *p;
232 int mime = ms->flags & MAGIC_MIME;
233
234 if (!mime)
235 return file_printf(ms, "ERROR:[%s: %s]", methodname(i), buf);
236
237 for (p = buf; *p; p++)
238 if (!isalnum(*p))
239 *p = '-';
240
241 return file_printf(ms, "application/x-decompression-error-%s-%s",
242 methodname(i), buf);
243 }
244
245 protected int
file_zmagic(struct magic_set * ms,const struct buffer * b,const char * name)246 file_zmagic(struct magic_set *ms, const struct buffer *b, const char *name)
247 {
248 unsigned char *newbuf = NULL;
249 size_t i, nsz;
250 char *rbuf;
251 file_pushbuf_t *pb;
252 int urv, prv, rv = 0;
253 int mime = ms->flags & MAGIC_MIME;
254 int fd = b->fd;
255 const unsigned char *buf = CAST(const unsigned char *, b->fbuf);
256 size_t nbytes = b->flen;
257 int sa_saved = 0;
258 struct sigaction sig_act;
259
260 if ((ms->flags & MAGIC_COMPRESS) == 0)
261 return 0;
262
263 for (i = 0; i < ncompr; i++) {
264 int zm;
265 if (nbytes < CAST(size_t, abs(compr[i].maglen)))
266 continue;
267 if (compr[i].maglen < 0) {
268 zm = (*compr[i].u.func)(buf);
269 } else {
270 zm = memcmp(buf, compr[i].u.magic,
271 CAST(size_t, compr[i].maglen)) == 0;
272 }
273
274 if (!zm)
275 continue;
276
277 /* Prevent SIGPIPE death if child dies unexpectedly */
278 if (!sa_saved) {
279 //We can use sig_act for both new and old, but
280 struct sigaction new_act;
281 memset(&new_act, 0, sizeof(new_act));
282 new_act.sa_handler = SIG_IGN;
283 sa_saved = sigaction(SIGPIPE, &new_act, &sig_act) != -1;
284 }
285
286 nsz = nbytes;
287 urv = uncompressbuf(fd, ms->bytes_max, i, buf, &newbuf, &nsz);
288 DPRINTF("uncompressbuf = %d, %s, %" SIZE_T_FORMAT "u\n", urv,
289 (char *)newbuf, nsz);
290 switch (urv) {
291 case OKDATA:
292 case ERRDATA:
293 ms->flags &= ~MAGIC_COMPRESS;
294 if (urv == ERRDATA)
295 prv = format_decompression_error(ms, i, newbuf);
296 else
297 prv = file_buffer(ms, -1, NULL, name, newbuf, nsz);
298 if (prv == -1)
299 goto error;
300 rv = 1;
301 if ((ms->flags & MAGIC_COMPRESS_TRANSP) != 0)
302 goto out;
303 if (mime != MAGIC_MIME && mime != 0)
304 goto out;
305 if ((file_printf(ms,
306 mime ? " compressed-encoding=" : " (")) == -1)
307 goto error;
308 if ((pb = file_push_buffer(ms)) == NULL)
309 goto error;
310 /*
311 * XXX: If file_buffer fails here, we overwrite
312 * the compressed text. FIXME.
313 */
314 if (file_buffer(ms, -1, NULL, NULL, buf, nbytes) == -1) {
315 if (file_pop_buffer(ms, pb) != NULL)
316 abort();
317 goto error;
318 }
319 if ((rbuf = file_pop_buffer(ms, pb)) != NULL) {
320 if (file_printf(ms, "%s", rbuf) == -1) {
321 free(rbuf);
322 goto error;
323 }
324 free(rbuf);
325 }
326 if (!mime && file_printf(ms, ")") == -1)
327 goto error;
328 /*FALLTHROUGH*/
329 case NODATA:
330 break;
331 default:
332 abort();
333 /*NOTREACHED*/
334 error:
335 rv = -1;
336 break;
337 }
338 }
339 out:
340 DPRINTF("rv = %d\n", rv);
341
342 if (sa_saved && sig_act.sa_handler != SIG_IGN)
343 (void)sigaction(SIGPIPE, &sig_act, NULL);
344
345 free(newbuf);
346 ms->flags |= MAGIC_COMPRESS;
347 DPRINTF("Zmagic returns %d\n", rv);
348 return rv;
349 }
350 #endif
351 /*
352 * `safe' write for sockets and pipes.
353 */
354 private ssize_t
swrite(int fd,const void * buf,size_t n)355 swrite(int fd, const void *buf, size_t n)
356 {
357 ssize_t rv;
358 size_t rn = n;
359
360 do
361 switch (rv = write(fd, buf, n)) {
362 case -1:
363 if (errno == EINTR)
364 continue;
365 return -1;
366 default:
367 n -= rv;
368 buf = CAST(const char *, buf) + rv;
369 break;
370 }
371 while (n > 0);
372 return rn;
373 }
374
375
376 /*
377 * `safe' read for sockets and pipes.
378 */
379 protected ssize_t
sread(int fd,void * buf,size_t n,int canbepipe)380 sread(int fd, void *buf, size_t n, int canbepipe __attribute__((__unused__)))
381 {
382 ssize_t rv;
383 #ifdef FIONREAD
384 int t = 0;
385 #endif
386 size_t rn = n;
387
388 if (fd == STDIN_FILENO)
389 goto nocheck;
390
391 #ifdef FIONREAD
392 if (canbepipe && (ioctl(fd, FIONREAD, &t) == -1 || t == 0)) {
393 #ifdef FD_ZERO
394 ssize_t cnt;
395 for (cnt = 0;; cnt++) {
396 fd_set check;
397 struct timeval tout = {0, 100 * 1000};
398 int selrv;
399
400 FD_ZERO(&check);
401 FD_SET(fd, &check);
402
403 /*
404 * Avoid soft deadlock: do not read if there
405 * is nothing to read from sockets and pipes.
406 */
407 selrv = select(fd + 1, &check, NULL, NULL, &tout);
408 if (selrv == -1) {
409 if (errno == EINTR || errno == EAGAIN)
410 continue;
411 } else if (selrv == 0 && cnt >= 5) {
412 return 0;
413 } else
414 break;
415 }
416 #endif
417 (void)ioctl(fd, FIONREAD, &t);
418 }
419
420 if (t > 0 && CAST(size_t, t) < n) {
421 n = t;
422 rn = n;
423 }
424 #endif
425
426 nocheck:
427 do
428 switch ((rv = read(fd, buf, n))) {
429 case -1:
430 if (errno == EINTR)
431 continue;
432 return -1;
433 case 0:
434 return rn - n;
435 default:
436 n -= rv;
437 buf = CAST(char *, CCAST(void *, buf)) + rv;
438 break;
439 }
440 while (n > 0);
441 return rn;
442 }
443
444 protected int
file_pipe2file(struct magic_set * ms,int fd,const void * startbuf,size_t nbytes)445 file_pipe2file(struct magic_set *ms, int fd, const void *startbuf,
446 size_t nbytes)
447 {
448 char buf[4096];
449 ssize_t r;
450 int tfd;
451
452 (void)strlcpy(buf, "/tmp/file.XXXXXX", sizeof buf);
453 #ifndef HAVE_MKSTEMP
454 {
455 char *ptr = mktemp(buf);
456 tfd = open(ptr, O_RDWR|O_TRUNC|O_EXCL|O_CREAT, 0600);
457 r = errno;
458 (void)unlink(ptr);
459 errno = r;
460 }
461 #else
462 {
463 int te;
464 mode_t ou = umask(0);
465 tfd = mkstemp(buf);
466 (void)umask(ou);
467 te = errno;
468 (void)unlink(buf);
469 errno = te;
470 }
471 #endif
472 if (tfd == -1) {
473 file_error(ms, errno,
474 "cannot create temporary file for pipe copy");
475 return -1;
476 }
477
478 if (swrite(tfd, startbuf, nbytes) != CAST(ssize_t, nbytes))
479 r = 1;
480 else {
481 while ((r = sread(fd, buf, sizeof(buf), 1)) > 0)
482 if (swrite(tfd, buf, CAST(size_t, r)) != r)
483 break;
484 }
485
486 switch (r) {
487 case -1:
488 file_error(ms, errno, "error copying from pipe to temp file");
489 return -1;
490 case 0:
491 break;
492 default:
493 file_error(ms, errno, "error while writing to temp file");
494 return -1;
495 }
496
497 /*
498 * We duplicate the file descriptor, because fclose on a
499 * tmpfile will delete the file, but any open descriptors
500 * can still access the phantom inode.
501 */
502 if ((fd = dup2(tfd, fd)) == -1) {
503 file_error(ms, errno, "could not dup descriptor for temp file");
504 return -1;
505 }
506 (void)close(tfd);
507 if (lseek(fd, CAST(off_t, 0), SEEK_SET) == CAST(off_t, -1)) {
508 file_badseek(ms);
509 return -1;
510 }
511 return fd;
512 }
513 #if HAVE_FORK
514 #ifdef BUILTIN_DECOMPRESS
515
516 #define FHCRC (1 << 1)
517 #define FEXTRA (1 << 2)
518 #define FNAME (1 << 3)
519 #define FCOMMENT (1 << 4)
520
521
522 private int
uncompressgzipped(const unsigned char * old,unsigned char ** newch,size_t bytes_max,size_t * n)523 uncompressgzipped(const unsigned char *old, unsigned char **newch,
524 size_t bytes_max, size_t *n)
525 {
526 unsigned char flg = old[3];
527 size_t data_start = 10;
528
529 if (flg & FEXTRA) {
530 if (data_start + 1 >= *n)
531 goto err;
532 data_start += 2 + old[data_start] + old[data_start + 1] * 256;
533 }
534 if (flg & FNAME) {
535 while(data_start < *n && old[data_start])
536 data_start++;
537 data_start++;
538 }
539 if (flg & FCOMMENT) {
540 while(data_start < *n && old[data_start])
541 data_start++;
542 data_start++;
543 }
544 if (flg & FHCRC)
545 data_start += 2;
546
547 if (data_start >= *n)
548 goto err;
549
550 *n -= data_start;
551 old += data_start;
552 return uncompresszlib(old, newch, bytes_max, n, 0);
553 err:
554 return makeerror(newch, n, "File too short");
555 }
556
557 private int
uncompresszlib(const unsigned char * old,unsigned char ** newch,size_t bytes_max,size_t * n,int zlib)558 uncompresszlib(const unsigned char *old, unsigned char **newch,
559 size_t bytes_max, size_t *n, int zlib)
560 {
561 int rc;
562 z_stream z;
563
564 if ((*newch = CAST(unsigned char *, malloc(bytes_max + 1))) == NULL)
565 return makeerror(newch, n, "No buffer, %s", strerror(errno));
566
567 z.next_in = CCAST(Bytef *, old);
568 z.avail_in = CAST(uint32_t, *n);
569 z.next_out = *newch;
570 z.avail_out = CAST(unsigned int, bytes_max);
571 z.zalloc = Z_NULL;
572 z.zfree = Z_NULL;
573 z.opaque = Z_NULL;
574
575 /* LINTED bug in header macro */
576 rc = zlib ? inflateInit(&z) : inflateInit2(&z, -15);
577 if (rc != Z_OK)
578 goto err;
579
580 rc = inflate(&z, Z_SYNC_FLUSH);
581 if (rc != Z_OK && rc != Z_STREAM_END)
582 goto err;
583
584 *n = CAST(size_t, z.total_out);
585 rc = inflateEnd(&z);
586 if (rc != Z_OK)
587 goto err;
588
589 /* let's keep the nul-terminate tradition */
590 (*newch)[*n] = '\0';
591
592 return OKDATA;
593 err:
594 strlcpy(RCAST(char *, *newch), z.msg ? z.msg : zError(rc), bytes_max);
595 *n = strlen(RCAST(char *, *newch));
596 return ERRDATA;
597 }
598 #endif
599
600 #ifdef BUILTIN_BZLIB
601 private int
uncompressbzlib(const unsigned char * old,unsigned char ** newch,size_t bytes_max,size_t * n)602 uncompressbzlib(const unsigned char *old, unsigned char **newch,
603 size_t bytes_max, size_t *n)
604 {
605 int rc;
606 bz_stream bz;
607
608 memset(&bz, 0, sizeof(bz));
609 rc = BZ2_bzDecompressInit(&bz, 0, 0);
610 if (rc != BZ_OK)
611 goto err;
612
613 if ((*newch = CAST(unsigned char *, malloc(bytes_max + 1))) == NULL)
614 return makeerror(newch, n, "No buffer, %s", strerror(errno));
615
616 bz.next_in = CCAST(char *, RCAST(const char *, old));
617 bz.avail_in = CAST(uint32_t, *n);
618 bz.next_out = RCAST(char *, *newch);
619 bz.avail_out = CAST(unsigned int, bytes_max);
620
621 rc = BZ2_bzDecompress(&bz);
622 if (rc != BZ_OK && rc != BZ_STREAM_END)
623 goto err;
624
625 /* Assume byte_max is within 32bit */
626 /* assert(bz.total_out_hi32 == 0); */
627 *n = CAST(size_t, bz.total_out_lo32);
628 rc = BZ2_bzDecompressEnd(&bz);
629 if (rc != BZ_OK)
630 goto err;
631
632 /* let's keep the nul-terminate tradition */
633 (*newch)[*n] = '\0';
634
635 return OKDATA;
636 err:
637 snprintf(RCAST(char *, *newch), bytes_max, "bunzip error %d", rc);
638 *n = strlen(RCAST(char *, *newch));
639 return ERRDATA;
640 }
641 #endif
642
643 #ifdef BUILTIN_XZLIB
644 private int
uncompressxzlib(const unsigned char * old,unsigned char ** newch,size_t bytes_max,size_t * n)645 uncompressxzlib(const unsigned char *old, unsigned char **newch,
646 size_t bytes_max, size_t *n)
647 {
648 int rc;
649 lzma_stream xz;
650
651 memset(&xz, 0, sizeof(xz));
652 rc = lzma_auto_decoder(&xz, UINT64_MAX, 0);
653 if (rc != LZMA_OK)
654 goto err;
655
656 if ((*newch = CAST(unsigned char *, malloc(bytes_max + 1))) == NULL)
657 return makeerror(newch, n, "No buffer, %s", strerror(errno));
658
659 xz.next_in = CCAST(const uint8_t *, old);
660 xz.avail_in = CAST(uint32_t, *n);
661 xz.next_out = RCAST(uint8_t *, *newch);
662 xz.avail_out = CAST(unsigned int, bytes_max);
663
664 rc = lzma_code(&xz, LZMA_RUN);
665 if (rc != LZMA_OK && rc != LZMA_STREAM_END)
666 goto err;
667
668 *n = CAST(size_t, xz.total_out);
669
670 lzma_end(&xz);
671
672 /* let's keep the nul-terminate tradition */
673 (*newch)[*n] = '\0';
674
675 return OKDATA;
676 err:
677 snprintf(RCAST(char *, *newch), bytes_max, "unxz error %d", rc);
678 *n = strlen(RCAST(char *, *newch));
679 return ERRDATA;
680 }
681 #endif
682
683
684 static int
makeerror(unsigned char ** buf,size_t * len,const char * fmt,...)685 makeerror(unsigned char **buf, size_t *len, const char *fmt, ...)
686 {
687 char *msg;
688 va_list ap;
689 int rv;
690
691 va_start(ap, fmt);
692 rv = vasprintf(&msg, fmt, ap);
693 va_end(ap);
694 if (rv < 0) {
695 *buf = NULL;
696 *len = 0;
697 return NODATA;
698 }
699 *buf = RCAST(unsigned char *, msg);
700 *len = strlen(msg);
701 return ERRDATA;
702 }
703
704 static void
closefd(int * fd,size_t i)705 closefd(int *fd, size_t i)
706 {
707 if (fd[i] == -1)
708 return;
709 (void) close(fd[i]);
710 fd[i] = -1;
711 }
712
713 static void
closep(int * fd)714 closep(int *fd)
715 {
716 size_t i;
717 for (i = 0; i < 2; i++)
718 closefd(fd, i);
719 }
720
721 static int
copydesc(int i,int fd)722 copydesc(int i, int fd)
723 {
724 if (fd == i)
725 return 0; /* "no dup was necessary" */
726 if (dup2(fd, i) == -1) {
727 DPRINTF("dup(%d, %d) failed (%s)\n", fd, i, strerror(errno));
728 exit(1);
729 }
730 return 1;
731 }
732
733 static pid_t
writechild(int fd,const void * old,size_t n)734 writechild(int fd, const void *old, size_t n)
735 {
736 pid_t pid;
737
738 /*
739 * fork again, to avoid blocking because both
740 * pipes filled
741 */
742 pid = fork();
743 if (pid == -1) {
744 DPRINTF("Fork failed (%s)\n", strerror(errno));
745 exit(1);
746 }
747 if (pid == 0) {
748 /* child */
749 if (swrite(fd, old, n) != CAST(ssize_t, n)) {
750 DPRINTF("Write failed (%s)\n", strerror(errno));
751 exit(1);
752 }
753 exit(0);
754 }
755 /* parent */
756 return pid;
757 }
758
759 static ssize_t
filter_error(unsigned char * ubuf,ssize_t n)760 filter_error(unsigned char *ubuf, ssize_t n)
761 {
762 char *p;
763 char *buf;
764
765 ubuf[n] = '\0';
766 buf = RCAST(char *, ubuf);
767 while (isspace(CAST(unsigned char, *buf)))
768 buf++;
769 DPRINTF("Filter error[[[%s]]]\n", buf);
770 if ((p = strchr(CAST(char *, buf), '\n')) != NULL)
771 *p = '\0';
772 if ((p = strchr(CAST(char *, buf), ';')) != NULL)
773 *p = '\0';
774 if ((p = strrchr(CAST(char *, buf), ':')) != NULL) {
775 ++p;
776 while (isspace(CAST(unsigned char, *p)))
777 p++;
778 n = strlen(p);
779 memmove(ubuf, p, CAST(size_t, n + 1));
780 }
781 DPRINTF("Filter error after[[[%s]]]\n", (char *)ubuf);
782 if (islower(*ubuf))
783 *ubuf = toupper(*ubuf);
784 return n;
785 }
786
787 private const char *
methodname(size_t method)788 methodname(size_t method)
789 {
790 switch (method) {
791 #ifdef BUILTIN_DECOMPRESS
792 case METH_FROZEN:
793 case METH_ZLIB:
794 return "zlib";
795 #endif
796 #ifdef BUILTIN_BZLIB
797 case METH_BZIP:
798 return "bzlib";
799 #endif
800 #ifdef BUILTIN_XZLIB
801 case METH_XZ:
802 case METH_LZMA:
803 return "xzlib";
804 #endif
805 default:
806 return compr[method].argv[0];
807 }
808 }
809
810 private int
uncompressbuf(int fd,size_t bytes_max,size_t method,const unsigned char * old,unsigned char ** newch,size_t * n)811 uncompressbuf(int fd, size_t bytes_max, size_t method, const unsigned char *old,
812 unsigned char **newch, size_t* n)
813 {
814 int fdp[3][2];
815 int status, rv, w;
816 pid_t pid;
817 pid_t writepid = -1;
818 size_t i;
819 ssize_t r;
820
821 switch (method) {
822 #ifdef BUILTIN_DECOMPRESS
823 case METH_FROZEN:
824 return uncompressgzipped(old, newch, bytes_max, n);
825 case METH_ZLIB:
826 return uncompresszlib(old, newch, bytes_max, n, 1);
827 #endif
828 #ifdef BUILTIN_BZLIB
829 case METH_BZIP:
830 return uncompressbzlib(old, newch, bytes_max, n);
831 #endif
832 #ifdef BUILTIN_XZLIB
833 case METH_XZ:
834 case METH_LZMA:
835 return uncompressxzlib(old, newch, bytes_max, n);
836 #endif
837 default:
838 break;
839 }
840
841 (void)fflush(stdout);
842 (void)fflush(stderr);
843
844 for (i = 0; i < __arraycount(fdp); i++)
845 fdp[i][0] = fdp[i][1] = -1;
846
847 if ((fd == -1 && pipe(fdp[STDIN_FILENO]) == -1) ||
848 pipe(fdp[STDOUT_FILENO]) == -1 || pipe(fdp[STDERR_FILENO]) == -1) {
849 closep(fdp[STDIN_FILENO]);
850 closep(fdp[STDOUT_FILENO]);
851 return makeerror(newch, n, "Cannot create pipe, %s",
852 strerror(errno));
853 }
854
855 /* For processes with large mapped virtual sizes, vfork
856 * may be _much_ faster (10-100 times) than fork.
857 */
858 pid = vfork();
859 if (pid == -1) {
860 return makeerror(newch, n, "Cannot vfork, %s",
861 strerror(errno));
862 }
863 if (pid == 0) {
864 /* child */
865 /* Note: we are after vfork, do not modify memory
866 * in a way which confuses parent. In particular,
867 * do not modify fdp[i][j].
868 */
869 if (fd != -1) {
870 (void) lseek(fd, CAST(off_t, 0), SEEK_SET);
871 if (copydesc(STDIN_FILENO, fd))
872 (void) close(fd);
873 } else {
874 if (copydesc(STDIN_FILENO, fdp[STDIN_FILENO][0]))
875 (void) close(fdp[STDIN_FILENO][0]);
876 if (fdp[STDIN_FILENO][1] > 2)
877 (void) close(fdp[STDIN_FILENO][1]);
878 }
879 ///FIXME: if one of the fdp[i][j] is 0 or 1, this can bomb spectacularly
880 if (copydesc(STDOUT_FILENO, fdp[STDOUT_FILENO][1]))
881 (void) close(fdp[STDOUT_FILENO][1]);
882 if (fdp[STDOUT_FILENO][0] > 2)
883 (void) close(fdp[STDOUT_FILENO][0]);
884
885 if (copydesc(STDERR_FILENO, fdp[STDERR_FILENO][1]))
886 (void) close(fdp[STDERR_FILENO][1]);
887 if (fdp[STDERR_FILENO][0] > 2)
888 (void) close(fdp[STDERR_FILENO][0]);
889
890 (void)execvp(compr[method].argv[0],
891 RCAST(char *const *, RCAST(intptr_t, compr[method].argv)));
892 dprintf(STDERR_FILENO, "exec `%s' failed, %s",
893 compr[method].argv[0], strerror(errno));
894 _exit(1); /* _exit(), not exit(), because of vfork */
895 }
896 /* parent */
897 /* Close write sides of child stdout/err pipes */
898 for (i = 1; i < __arraycount(fdp); i++)
899 closefd(fdp[i], 1);
900 /* Write the buffer data to child stdin, if we don't have fd */
901 if (fd == -1) {
902 closefd(fdp[STDIN_FILENO], 0);
903 writepid = writechild(fdp[STDIN_FILENO][1], old, *n);
904 closefd(fdp[STDIN_FILENO], 1);
905 }
906
907 *newch = CAST(unsigned char *, malloc(bytes_max + 1));
908 if (*newch == NULL) {
909 rv = makeerror(newch, n, "No buffer, %s",
910 strerror(errno));
911 goto err;
912 }
913 rv = OKDATA;
914 r = sread(fdp[STDOUT_FILENO][0], *newch, bytes_max, 0);
915 if (r <= 0) {
916 DPRINTF("Read stdout failed %d (%s)\n", fdp[STDOUT_FILENO][0],
917 r != -1 ? strerror(errno) : "no data");
918
919 rv = ERRDATA;
920 if (r == 0 &&
921 (r = sread(fdp[STDERR_FILENO][0], *newch, bytes_max, 0)) > 0)
922 {
923 r = filter_error(*newch, r);
924 goto ok;
925 }
926 free(*newch);
927 if (r == 0)
928 rv = makeerror(newch, n, "Read failed, %s",
929 strerror(errno));
930 else
931 rv = makeerror(newch, n, "No data");
932 goto err;
933 }
934 ok:
935 *n = r;
936 /* NUL terminate, as every buffer is handled here. */
937 (*newch)[*n] = '\0';
938 err:
939 closefd(fdp[STDIN_FILENO], 1);
940 closefd(fdp[STDOUT_FILENO], 0);
941 closefd(fdp[STDERR_FILENO], 0);
942
943 w = waitpid(pid, &status, 0);
944 wait_err:
945 if (w == -1) {
946 free(*newch);
947 rv = makeerror(newch, n, "Wait failed, %s", strerror(errno));
948 DPRINTF("Child wait return %#x\n", status);
949 } else if (!WIFEXITED(status)) {
950 DPRINTF("Child not exited (%#x)\n", status);
951 } else if (WEXITSTATUS(status) != 0) {
952 DPRINTF("Child exited (%#x)\n", WEXITSTATUS(status));
953 }
954 if (writepid > 0) {
955 /* _After_ we know decompressor has exited, our input writer
956 * definitely will exit now (at worst, writing fails in it,
957 * since output fd is closed now on the reading size).
958 */
959 w = waitpid(writepid, &status, 0);
960 writepid = -1;
961 goto wait_err;
962 }
963
964 closefd(fdp[STDIN_FILENO], 0); //why? it is already closed here!
965 DPRINTF("Returning %p n=%" SIZE_T_FORMAT "u rv=%d\n", *newch, *n, rv);
966
967 return rv;
968 }
969 #endif
970