1 /* $NetBSD: compress.c,v 1.18 2019/05/22 17:26:05 christos Exp $ */ 2 3 /* 4 * Copyright (c) Ian F. Darwin 1986-1995. 5 * Software written by Ian F. Darwin and others; 6 * maintained 1995-present by Christos Zoulas and others. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice immediately at the beginning of the file, without modification, 13 * this list of conditions, and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 22 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 /* 31 * compress routines: 32 * zmagic() - returns 0 if not recognized, uncompresses and prints 33 * information if recognized 34 * uncompress(method, old, n, newch) - uncompress old into new, 35 * using method, return sizeof new 36 */ 37 #include "file.h" 38 39 #ifndef lint 40 #if 0 41 FILE_RCSID("@(#)$File: compress.c,v 1.121 2019/05/07 02:27:11 christos Exp $") 42 #else 43 __RCSID("$NetBSD: compress.c,v 1.18 2019/05/22 17:26:05 christos Exp $"); 44 #endif 45 #endif 46 47 #include "magic.h" 48 #include <stdlib.h> 49 #ifdef HAVE_UNISTD_H 50 #include <unistd.h> 51 #endif 52 #include <string.h> 53 #include <errno.h> 54 #include <ctype.h> 55 #include <stdarg.h> 56 #include <signal.h> 57 #ifndef HAVE_SIG_T 58 typedef void (*sig_t)(int); 59 #endif /* HAVE_SIG_T */ 60 #if !defined(__MINGW32__) && !defined(WIN32) 61 #include <sys/ioctl.h> 62 #endif 63 #ifdef HAVE_SYS_WAIT_H 64 #include <sys/wait.h> 65 #endif 66 #if defined(HAVE_SYS_TIME_H) 67 #include <sys/time.h> 68 #endif 69 70 #if defined(HAVE_ZLIB_H) && defined(ZLIBSUPPORT) 71 #define BUILTIN_DECOMPRESS 72 #include <zlib.h> 73 #endif 74 75 #if defined(HAVE_BZLIB_H) 76 #define BUILTIN_BZLIB 77 #include <bzlib.h> 78 #endif 79 80 #ifdef DEBUG 81 int tty = -1; 82 #define DPRINTF(...) do { \ 83 if (tty == -1) \ 84 tty = open("/dev/tty", O_RDWR); \ 85 if (tty == -1) \ 86 abort(); \ 87 dprintf(tty, __VA_ARGS__); \ 88 } while (/*CONSTCOND*/0) 89 #else 90 #define DPRINTF(...) 91 #endif 92 93 #ifdef ZLIBSUPPORT 94 /* 95 * The following python code is not really used because ZLIBSUPPORT is only 96 * defined if we have a built-in zlib, and the built-in zlib handles that. 97 * That is not true for android where we have zlib.h and not -lz. 98 */ 99 static const char zlibcode[] = 100 "import sys, zlib; sys.stdout.write(zlib.decompress(sys.stdin.read()))"; 101 102 static const char *zlib_args[] = { "python", "-c", zlibcode, NULL }; 103 104 static int 105 zlibcmp(const unsigned char *buf) 106 { 107 unsigned short x = 1; 108 unsigned char *s = CAST(unsigned char *, CAST(void *, &x)); 109 110 if ((buf[0] & 0xf) != 8 || (buf[0] & 0x80) != 0) 111 return 0; 112 if (s[0] != 1) /* endianness test */ 113 x = buf[0] | (buf[1] << 8); 114 else 115 x = buf[1] | (buf[0] << 8); 116 if (x % 31) 117 return 0; 118 return 1; 119 } 120 #endif 121 122 #define gzip_flags "-cd" 123 #define lrzip_flags "-do" 124 #define lzip_flags gzip_flags 125 126 static const char *gzip_args[] = { 127 "gzip", gzip_flags, NULL 128 }; 129 static const char *uncompress_args[] = { 130 "uncompress", "-c", NULL 131 }; 132 static const char *bzip2_args[] = { 133 "bzip2", "-cd", NULL 134 }; 135 static const char *lzip_args[] = { 136 "lzip", lzip_flags, NULL 137 }; 138 static const char *xz_args[] = { 139 "xz", "-cd", NULL 140 }; 141 static const char *lrzip_args[] = { 142 "lrzip", lrzip_flags, NULL 143 }; 144 static const char *lz4_args[] = { 145 "lz4", "-cd", NULL 146 }; 147 static const char *zstd_args[] = { 148 "zstd", "-cd", NULL 149 }; 150 151 #define do_zlib NULL 152 #define do_bzlib NULL 153 154 private const struct { 155 const void *magic; 156 size_t maglen; 157 const char **argv; 158 void *unused; 159 } compr[] = { 160 { "\037\235", 2, gzip_args, NULL }, /* compressed */ 161 /* Uncompress can get stuck; so use gzip first if we have it 162 * Idea from Damien Clark, thanks! */ 163 { "\037\235", 2, uncompress_args, NULL }, /* compressed */ 164 { "\037\213", 2, gzip_args, do_zlib }, /* gzipped */ 165 { "\037\236", 2, gzip_args, NULL }, /* frozen */ 166 { "\037\240", 2, gzip_args, NULL }, /* SCO LZH */ 167 /* the standard pack utilities do not accept standard input */ 168 { "\037\036", 2, gzip_args, NULL }, /* packed */ 169 { "PK\3\4", 4, gzip_args, NULL }, /* pkzipped, */ 170 /* ...only first file examined */ 171 { "BZh", 3, bzip2_args, do_bzlib }, /* bzip2-ed */ 172 { "LZIP", 4, lzip_args, NULL }, /* lzip-ed */ 173 { "\3757zXZ\0", 6, xz_args, NULL }, /* XZ Utils */ 174 { "LRZI", 4, lrzip_args, NULL }, /* LRZIP */ 175 { "\004\"M\030",4, lz4_args, NULL }, /* LZ4 */ 176 { "\x28\xB5\x2F\xFD", 4, zstd_args, NULL }, /* zstd */ 177 #ifdef ZLIBSUPPORT 178 { RCAST(const void *, zlibcmp), 0, zlib_args, NULL }, /* zlib */ 179 #endif 180 }; 181 182 #define OKDATA 0 183 #define NODATA 1 184 #define ERRDATA 2 185 186 private ssize_t swrite(int, const void *, size_t); 187 #if HAVE_FORK 188 private size_t ncompr = __arraycount(compr); 189 private int uncompressbuf(int, size_t, size_t, const unsigned char *, 190 unsigned char **, size_t *); 191 #ifdef BUILTIN_DECOMPRESS 192 private int uncompresszlib(const unsigned char *, unsigned char **, size_t, 193 size_t *, int); 194 private int uncompressgzipped(const unsigned char *, unsigned char **, size_t, 195 size_t *); 196 #endif 197 #ifdef BUILTIN_BZLIB 198 private int uncompressbzlib(const unsigned char *, unsigned char **, size_t, 199 size_t *, int); 200 #endif 201 202 static int makeerror(unsigned char **, size_t *, const char *, ...) 203 __attribute__((__format__(__printf__, 3, 4))); 204 private const char *methodname(size_t); 205 206 private int 207 format_decompression_error(struct magic_set *ms, size_t i, unsigned char *buf) 208 { 209 unsigned char *p; 210 int mime = ms->flags & MAGIC_MIME; 211 212 if (!mime) 213 return file_printf(ms, "ERROR:[%s: %s]", methodname(i), buf); 214 215 for (p = buf; *p; p++) 216 if (!isalnum(*p)) 217 *p = '-'; 218 219 return file_printf(ms, "application/x-decompression-error-%s-%s", 220 methodname(i), buf); 221 } 222 223 protected int 224 file_zmagic(struct magic_set *ms, const struct buffer *b, const char *name) 225 { 226 unsigned char *newbuf = NULL; 227 size_t i, nsz; 228 char *rbuf; 229 file_pushbuf_t *pb; 230 int urv, prv, rv = 0; 231 int mime = ms->flags & MAGIC_MIME; 232 int fd = b->fd; 233 const unsigned char *buf = CAST(const unsigned char *, b->fbuf); 234 size_t nbytes = b->flen; 235 int sa_saved = 0; 236 struct sigaction sig_act; 237 238 if ((ms->flags & MAGIC_COMPRESS) == 0) 239 return 0; 240 241 for (i = 0; i < ncompr; i++) { 242 int zm; 243 if (nbytes < compr[i].maglen) 244 continue; 245 #ifdef ZLIBSUPPORT 246 if (compr[i].maglen == 0) 247 zm = (RCAST(int (*)(const unsigned char *), 248 CCAST(void *, compr[i].magic)))(buf); 249 else 250 #endif 251 zm = memcmp(buf, compr[i].magic, compr[i].maglen) == 0; 252 253 if (!zm) 254 continue; 255 256 /* Prevent SIGPIPE death if child dies unexpectedly */ 257 if (!sa_saved) { 258 //We can use sig_act for both new and old, but 259 struct sigaction new_act; 260 memset(&new_act, 0, sizeof(new_act)); 261 new_act.sa_handler = SIG_IGN; 262 sa_saved = sigaction(SIGPIPE, &new_act, &sig_act) != -1; 263 } 264 265 nsz = nbytes; 266 urv = uncompressbuf(fd, ms->bytes_max, i, buf, &newbuf, &nsz); 267 DPRINTF("uncompressbuf = %d, %s, %" SIZE_T_FORMAT "u\n", urv, 268 (char *)newbuf, nsz); 269 switch (urv) { 270 case OKDATA: 271 case ERRDATA: 272 ms->flags &= ~MAGIC_COMPRESS; 273 if (urv == ERRDATA) 274 prv = format_decompression_error(ms, i, newbuf); 275 else 276 prv = file_buffer(ms, -1, NULL, name, newbuf, nsz); 277 if (prv == -1) 278 goto error; 279 rv = 1; 280 if ((ms->flags & MAGIC_COMPRESS_TRANSP) != 0) 281 goto out; 282 if (mime != MAGIC_MIME && mime != 0) 283 goto out; 284 if ((file_printf(ms, 285 mime ? " compressed-encoding=" : " (")) == -1) 286 goto error; 287 if ((pb = file_push_buffer(ms)) == NULL) 288 goto error; 289 /* 290 * XXX: If file_buffer fails here, we overwrite 291 * the compressed text. FIXME. 292 */ 293 if (file_buffer(ms, -1, NULL, NULL, buf, nbytes) == -1) { 294 if (file_pop_buffer(ms, pb) != NULL) 295 abort(); 296 goto error; 297 } 298 if ((rbuf = file_pop_buffer(ms, pb)) != NULL) { 299 if (file_printf(ms, "%s", rbuf) == -1) { 300 free(rbuf); 301 goto error; 302 } 303 free(rbuf); 304 } 305 if (!mime && file_printf(ms, ")") == -1) 306 goto error; 307 /*FALLTHROUGH*/ 308 case NODATA: 309 break; 310 default: 311 abort(); 312 /*NOTREACHED*/ 313 error: 314 rv = -1; 315 break; 316 } 317 } 318 out: 319 DPRINTF("rv = %d\n", rv); 320 321 if (sa_saved && sig_act.sa_handler != SIG_IGN) 322 (void)sigaction(SIGPIPE, &sig_act, NULL); 323 324 free(newbuf); 325 ms->flags |= MAGIC_COMPRESS; 326 DPRINTF("Zmagic returns %d\n", rv); 327 return rv; 328 } 329 #endif 330 /* 331 * `safe' write for sockets and pipes. 332 */ 333 private ssize_t 334 swrite(int fd, const void *buf, size_t n) 335 { 336 ssize_t rv; 337 size_t rn = n; 338 339 do 340 switch (rv = write(fd, buf, n)) { 341 case -1: 342 if (errno == EINTR) 343 continue; 344 return -1; 345 default: 346 n -= rv; 347 buf = CAST(const char *, buf) + rv; 348 break; 349 } 350 while (n > 0); 351 return rn; 352 } 353 354 355 /* 356 * `safe' read for sockets and pipes. 357 */ 358 protected ssize_t 359 sread(int fd, void *buf, size_t n, int canbepipe __attribute__((__unused__))) 360 { 361 ssize_t rv; 362 #ifdef FIONREAD 363 int t = 0; 364 #endif 365 size_t rn = n; 366 367 if (fd == STDIN_FILENO) 368 goto nocheck; 369 370 #ifdef FIONREAD 371 if (canbepipe && (ioctl(fd, FIONREAD, &t) == -1 || t == 0)) { 372 #ifdef FD_ZERO 373 ssize_t cnt; 374 for (cnt = 0;; cnt++) { 375 fd_set check; 376 struct timeval tout = {0, 100 * 1000}; 377 int selrv; 378 379 FD_ZERO(&check); 380 FD_SET(fd, &check); 381 382 /* 383 * Avoid soft deadlock: do not read if there 384 * is nothing to read from sockets and pipes. 385 */ 386 selrv = select(fd + 1, &check, NULL, NULL, &tout); 387 if (selrv == -1) { 388 if (errno == EINTR || errno == EAGAIN) 389 continue; 390 } else if (selrv == 0 && cnt >= 5) { 391 return 0; 392 } else 393 break; 394 } 395 #endif 396 (void)ioctl(fd, FIONREAD, &t); 397 } 398 399 if (t > 0 && CAST(size_t, t) < n) { 400 n = t; 401 rn = n; 402 } 403 #endif 404 405 nocheck: 406 do 407 switch ((rv = read(fd, buf, n))) { 408 case -1: 409 if (errno == EINTR) 410 continue; 411 return -1; 412 case 0: 413 return rn - n; 414 default: 415 n -= rv; 416 buf = CAST(char *, CCAST(void *, buf)) + rv; 417 break; 418 } 419 while (n > 0); 420 return rn; 421 } 422 423 protected int 424 file_pipe2file(struct magic_set *ms, int fd, const void *startbuf, 425 size_t nbytes) 426 { 427 char buf[4096]; 428 ssize_t r; 429 int tfd; 430 431 (void)strlcpy(buf, "/tmp/file.XXXXXX", sizeof buf); 432 #ifndef HAVE_MKSTEMP 433 { 434 char *ptr = mktemp(buf); 435 tfd = open(ptr, O_RDWR|O_TRUNC|O_EXCL|O_CREAT, 0600); 436 r = errno; 437 (void)unlink(ptr); 438 errno = r; 439 } 440 #else 441 { 442 int te; 443 mode_t ou = umask(0); 444 tfd = mkstemp(buf); 445 (void)umask(ou); 446 te = errno; 447 (void)unlink(buf); 448 errno = te; 449 } 450 #endif 451 if (tfd == -1) { 452 file_error(ms, errno, 453 "cannot create temporary file for pipe copy"); 454 return -1; 455 } 456 457 if (swrite(tfd, startbuf, nbytes) != CAST(ssize_t, nbytes)) 458 r = 1; 459 else { 460 while ((r = sread(fd, buf, sizeof(buf), 1)) > 0) 461 if (swrite(tfd, buf, CAST(size_t, r)) != r) 462 break; 463 } 464 465 switch (r) { 466 case -1: 467 file_error(ms, errno, "error copying from pipe to temp file"); 468 return -1; 469 case 0: 470 break; 471 default: 472 file_error(ms, errno, "error while writing to temp file"); 473 return -1; 474 } 475 476 /* 477 * We duplicate the file descriptor, because fclose on a 478 * tmpfile will delete the file, but any open descriptors 479 * can still access the phantom inode. 480 */ 481 if ((fd = dup2(tfd, fd)) == -1) { 482 file_error(ms, errno, "could not dup descriptor for temp file"); 483 return -1; 484 } 485 (void)close(tfd); 486 if (lseek(fd, CAST(off_t, 0), SEEK_SET) == CAST(off_t, -1)) { 487 file_badseek(ms); 488 return -1; 489 } 490 return fd; 491 } 492 #if HAVE_FORK 493 #ifdef BUILTIN_DECOMPRESS 494 495 #define FHCRC (1 << 1) 496 #define FEXTRA (1 << 2) 497 #define FNAME (1 << 3) 498 #define FCOMMENT (1 << 4) 499 500 501 private int 502 uncompressgzipped(const unsigned char *old, unsigned char **newch, 503 size_t bytes_max, size_t *n) 504 { 505 unsigned char flg = old[3]; 506 size_t data_start = 10; 507 508 if (flg & FEXTRA) { 509 if (data_start + 1 >= *n) 510 goto err; 511 data_start += 2 + old[data_start] + old[data_start + 1] * 256; 512 } 513 if (flg & FNAME) { 514 while(data_start < *n && old[data_start]) 515 data_start++; 516 data_start++; 517 } 518 if (flg & FCOMMENT) { 519 while(data_start < *n && old[data_start]) 520 data_start++; 521 data_start++; 522 } 523 if (flg & FHCRC) 524 data_start += 2; 525 526 if (data_start >= *n) 527 goto err; 528 529 *n -= data_start; 530 old += data_start; 531 return uncompresszlib(old, newch, bytes_max, n, 0); 532 err: 533 return makeerror(newch, n, "File too short"); 534 } 535 536 private int 537 uncompresszlib(const unsigned char *old, unsigned char **newch, 538 size_t bytes_max, size_t *n, int zlib) 539 { 540 int rc; 541 z_stream z; 542 543 if ((*newch = CAST(unsigned char *, malloc(bytes_max + 1))) == NULL) 544 return makeerror(newch, n, "No buffer, %s", strerror(errno)); 545 546 z.next_in = CCAST(Bytef *, old); 547 z.avail_in = CAST(uint32_t, *n); 548 z.next_out = *newch; 549 z.avail_out = CAST(unsigned int, bytes_max); 550 z.zalloc = Z_NULL; 551 z.zfree = Z_NULL; 552 z.opaque = Z_NULL; 553 554 /* LINTED bug in header macro */ 555 rc = zlib ? inflateInit(&z) : inflateInit2(&z, -15); 556 if (rc != Z_OK) 557 goto err; 558 559 rc = inflate(&z, Z_SYNC_FLUSH); 560 if (rc != Z_OK && rc != Z_STREAM_END) 561 goto err; 562 563 *n = CAST(size_t, z.total_out); 564 rc = inflateEnd(&z); 565 if (rc != Z_OK) 566 goto err; 567 568 /* let's keep the nul-terminate tradition */ 569 (*newch)[*n] = '\0'; 570 571 return OKDATA; 572 err: 573 strlcpy(RCAST(char *, *newch), z.msg ? z.msg : zError(rc), bytes_max); 574 *n = strlen(RCAST(char *, *newch)); 575 return ERRDATA; 576 } 577 #endif 578 579 static int 580 makeerror(unsigned char **buf, size_t *len, const char *fmt, ...) 581 { 582 char *msg; 583 va_list ap; 584 int rv; 585 586 va_start(ap, fmt); 587 rv = vasprintf(&msg, fmt, ap); 588 va_end(ap); 589 if (rv < 0) { 590 *buf = NULL; 591 *len = 0; 592 return NODATA; 593 } 594 *buf = RCAST(unsigned char *, msg); 595 *len = strlen(msg); 596 return ERRDATA; 597 } 598 599 static void 600 closefd(int *fd, size_t i) 601 { 602 if (fd[i] == -1) 603 return; 604 (void) close(fd[i]); 605 fd[i] = -1; 606 } 607 608 static void 609 closep(int *fd) 610 { 611 size_t i; 612 for (i = 0; i < 2; i++) 613 closefd(fd, i); 614 } 615 616 static int 617 copydesc(int i, int fd) 618 { 619 if (fd == i) 620 return 0; /* "no dup was necessary" */ 621 if (dup2(fd, i) == -1) { 622 DPRINTF("dup(%d, %d) failed (%s)\n", fd, i, strerror(errno)); 623 exit(1); 624 } 625 return 1; 626 } 627 628 static pid_t 629 writechild(int fd, const void *old, size_t n) 630 { 631 pid_t pid; 632 633 /* 634 * fork again, to avoid blocking because both 635 * pipes filled 636 */ 637 pid = fork(); 638 if (pid == -1) { 639 DPRINTF("Fork failed (%s)\n", strerror(errno)); 640 exit(1); 641 } 642 if (pid == 0) { 643 /* child */ 644 if (swrite(fd, old, n) != CAST(ssize_t, n)) { 645 DPRINTF("Write failed (%s)\n", strerror(errno)); 646 exit(1); 647 } 648 exit(0); 649 } 650 /* parent */ 651 return pid; 652 } 653 654 static ssize_t 655 filter_error(unsigned char *ubuf, ssize_t n) 656 { 657 char *p; 658 char *buf; 659 660 ubuf[n] = '\0'; 661 buf = RCAST(char *, ubuf); 662 while (isspace(CAST(unsigned char, *buf))) 663 buf++; 664 DPRINTF("Filter error[[[%s]]]\n", buf); 665 if ((p = strchr(CAST(char *, buf), '\n')) != NULL) 666 *p = '\0'; 667 if ((p = strchr(CAST(char *, buf), ';')) != NULL) 668 *p = '\0'; 669 if ((p = strrchr(CAST(char *, buf), ':')) != NULL) { 670 ++p; 671 while (isspace(CAST(unsigned char, *p))) 672 p++; 673 n = strlen(p); 674 memmove(ubuf, p, CAST(size_t, n + 1)); 675 } 676 DPRINTF("Filter error after[[[%s]]]\n", (char *)ubuf); 677 if (islower(*ubuf)) 678 *ubuf = toupper(*ubuf); 679 return n; 680 } 681 682 private const char * 683 methodname(size_t method) 684 { 685 #ifdef BUILTIN_DECOMPRESS 686 /* FIXME: This doesn't cope with bzip2 */ 687 if (method == 2 || compr[method].maglen == 0) 688 return "zlib"; 689 #endif 690 return compr[method].argv[0]; 691 } 692 693 private int 694 uncompressbuf(int fd, size_t bytes_max, size_t method, const unsigned char *old, 695 unsigned char **newch, size_t* n) 696 { 697 int fdp[3][2]; 698 int status, rv, w; 699 pid_t pid; 700 pid_t writepid = -1; 701 size_t i; 702 ssize_t r; 703 704 #ifdef BUILTIN_DECOMPRESS 705 /* FIXME: This doesn't cope with bzip2 */ 706 if (method == 2) 707 return uncompressgzipped(old, newch, bytes_max, n); 708 if (compr[method].maglen == 0) 709 return uncompresszlib(old, newch, bytes_max, n, 1); 710 #endif 711 (void)fflush(stdout); 712 (void)fflush(stderr); 713 714 for (i = 0; i < __arraycount(fdp); i++) 715 fdp[i][0] = fdp[i][1] = -1; 716 717 if ((fd == -1 && pipe(fdp[STDIN_FILENO]) == -1) || 718 pipe(fdp[STDOUT_FILENO]) == -1 || pipe(fdp[STDERR_FILENO]) == -1) { 719 closep(fdp[STDIN_FILENO]); 720 closep(fdp[STDOUT_FILENO]); 721 return makeerror(newch, n, "Cannot create pipe, %s", 722 strerror(errno)); 723 } 724 725 /* For processes with large mapped virtual sizes, vfork 726 * may be _much_ faster (10-100 times) than fork. 727 */ 728 pid = vfork(); 729 if (pid == -1) { 730 return makeerror(newch, n, "Cannot vfork, %s", 731 strerror(errno)); 732 } 733 if (pid == 0) { 734 /* child */ 735 /* Note: we are after vfork, do not modify memory 736 * in a way which confuses parent. In particular, 737 * do not modify fdp[i][j]. 738 */ 739 if (fd != -1) { 740 (void) lseek(fd, CAST(off_t, 0), SEEK_SET); 741 if (copydesc(STDIN_FILENO, fd)) 742 (void) close(fd); 743 } else { 744 if (copydesc(STDIN_FILENO, fdp[STDIN_FILENO][0])) 745 (void) close(fdp[STDIN_FILENO][0]); 746 if (fdp[STDIN_FILENO][1] > 2) 747 (void) close(fdp[STDIN_FILENO][1]); 748 } 749 ///FIXME: if one of the fdp[i][j] is 0 or 1, this can bomb spectacularly 750 if (copydesc(STDOUT_FILENO, fdp[STDOUT_FILENO][1])) 751 (void) close(fdp[STDOUT_FILENO][1]); 752 if (fdp[STDOUT_FILENO][0] > 2) 753 (void) close(fdp[STDOUT_FILENO][0]); 754 755 if (copydesc(STDERR_FILENO, fdp[STDERR_FILENO][1])) 756 (void) close(fdp[STDERR_FILENO][1]); 757 if (fdp[STDERR_FILENO][0] > 2) 758 (void) close(fdp[STDERR_FILENO][0]); 759 760 (void)execvp(compr[method].argv[0], 761 RCAST(char *const *, RCAST(intptr_t, compr[method].argv))); 762 dprintf(STDERR_FILENO, "exec `%s' failed, %s", 763 compr[method].argv[0], strerror(errno)); 764 _exit(1); /* _exit(), not exit(), because of vfork */ 765 } 766 /* parent */ 767 /* Close write sides of child stdout/err pipes */ 768 for (i = 1; i < __arraycount(fdp); i++) 769 closefd(fdp[i], 1); 770 /* Write the buffer data to child stdin, if we don't have fd */ 771 if (fd == -1) { 772 closefd(fdp[STDIN_FILENO], 0); 773 writepid = writechild(fdp[STDIN_FILENO][1], old, *n); 774 closefd(fdp[STDIN_FILENO], 1); 775 } 776 777 *newch = CAST(unsigned char *, malloc(bytes_max + 1)); 778 if (*newch == NULL) { 779 rv = makeerror(newch, n, "No buffer, %s", 780 strerror(errno)); 781 goto err; 782 } 783 rv = OKDATA; 784 r = sread(fdp[STDOUT_FILENO][0], *newch, bytes_max, 0); 785 if (r <= 0) { 786 DPRINTF("Read stdout failed %d (%s)\n", fdp[STDOUT_FILENO][0], 787 r != -1 ? strerror(errno) : "no data"); 788 789 rv = ERRDATA; 790 if (r == 0 && 791 (r = sread(fdp[STDERR_FILENO][0], *newch, bytes_max, 0)) > 0) 792 { 793 r = filter_error(*newch, r); 794 goto ok; 795 } 796 free(*newch); 797 if (r == 0) 798 rv = makeerror(newch, n, "Read failed, %s", 799 strerror(errno)); 800 else 801 rv = makeerror(newch, n, "No data"); 802 goto err; 803 } 804 ok: 805 *n = r; 806 /* NUL terminate, as every buffer is handled here. */ 807 (*newch)[*n] = '\0'; 808 err: 809 closefd(fdp[STDIN_FILENO], 1); 810 closefd(fdp[STDOUT_FILENO], 0); 811 closefd(fdp[STDERR_FILENO], 0); 812 813 w = waitpid(pid, &status, 0); 814 wait_err: 815 if (w == -1) { 816 free(*newch); 817 rv = makeerror(newch, n, "Wait failed, %s", strerror(errno)); 818 DPRINTF("Child wait return %#x\n", status); 819 } else if (!WIFEXITED(status)) { 820 DPRINTF("Child not exited (%#x)\n", status); 821 } else if (WEXITSTATUS(status) != 0) { 822 DPRINTF("Child exited (%#x)\n", WEXITSTATUS(status)); 823 } 824 if (writepid > 0) { 825 /* _After_ we know decompressor has exited, our input writer 826 * definitely will exit now (at worst, writing fails in it, 827 * since output fd is closed now on the reading size). 828 */ 829 w = waitpid(writepid, &status, 0); 830 writepid = -1; 831 goto wait_err; 832 } 833 834 closefd(fdp[STDIN_FILENO], 0); //why? it is already closed here! 835 DPRINTF("Returning %p n=%" SIZE_T_FORMAT "u rv=%d\n", *newch, *n, rv); 836 837 return rv; 838 } 839 #endif 840