file_subs.c revision 1.61.12.1
1/* $NetBSD: file_subs.c,v 1.61.12.1 2009/05/13 19:15:50 jym Exp $ */ 2 3/*- 4 * Copyright (c) 1992 Keith Muller. 5 * Copyright (c) 1992, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Keith Muller of the University of California, San Diego. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36#if HAVE_NBTOOL_CONFIG_H 37#include "nbtool_config.h" 38#endif 39 40#include <sys/cdefs.h> 41#if !defined(lint) 42#if 0 43static char sccsid[] = "@(#)file_subs.c 8.1 (Berkeley) 5/31/93"; 44#else 45__RCSID("$NetBSD: file_subs.c,v 1.61.12.1 2009/05/13 19:15:50 jym Exp $"); 46#endif 47#endif /* not lint */ 48 49#include <sys/types.h> 50#include <sys/time.h> 51#include <sys/stat.h> 52#include <unistd.h> 53#include <sys/param.h> 54#include <fcntl.h> 55#include <string.h> 56#include <stdio.h> 57#include <ctype.h> 58#include <errno.h> 59#include <sys/uio.h> 60#include <stdlib.h> 61#include "pax.h" 62#include "extern.h" 63#include "options.h" 64 65char *xtmp_name; 66 67static int 68mk_link(char *,struct stat *,char *, int); 69 70static int warn_broken; 71 72/* 73 * routines that deal with file operations such as: creating, removing; 74 * and setting access modes, uid/gid and times of files 75 */ 76#define SET_BITS (S_ISUID | S_ISGID) 77#define FILE_BITS (S_IRWXU | S_IRWXG | S_IRWXO) 78#define A_BITS (FILE_BITS | SET_BITS | S_ISVTX) 79 80/* 81 * The S_ISVTX (sticky bit) can be set by non-superuser on directories 82 * but not other kinds of files. 83 */ 84#define FILEBITS(dir) ((dir) ? (FILE_BITS | S_ISVTX) : FILE_BITS) 85#define SETBITS(dir) ((dir) ? SET_BITS : (SET_BITS | S_ISVTX)) 86 87static mode_t 88apply_umask(mode_t mode) 89{ 90 static mode_t cached_umask; 91 static int cached_umask_valid; 92 93 if (!cached_umask_valid) { 94 cached_umask = umask(0); 95 umask(cached_umask); 96 cached_umask_valid = 1; 97 } 98 99 return mode & ~cached_umask; 100} 101 102/* 103 * file_creat() 104 * Create and open a file. 105 * Return: 106 * file descriptor or -1 for failure 107 */ 108 109int 110file_creat(ARCHD *arcn, int write_to_hardlink) 111{ 112 int fd = -1; 113 int oerrno; 114 115 /* 116 * Some horribly busted tar implementations, have directory nodes 117 * that end in a /, but they mark as files. Compensate for that 118 * by not creating a directory node at this point, but a file node, 119 * and not creating the temp file. 120 */ 121 if (arcn->nlen != 0 && arcn->name[arcn->nlen - 1] == '/') { 122 if (!warn_broken) { 123 tty_warn(0, "Archive was created with a broken tar;" 124 " file `%s' is a directory, but marked as plain.", 125 arcn->name); 126 warn_broken = 1; 127 } 128 return -1; 129 } 130 131 /* 132 * In "cpio" archives it's usually the last record of a set of 133 * hardlinks which includes the contents of the file. We cannot 134 * use a tempory file in that case because we couldn't link it 135 * with the existing other hardlinks after restoring the contents 136 * to it. And it's also useless to create the hardlink under a 137 * temporary name because the other hardlinks would have partial 138 * contents while restoring. 139 */ 140 if (write_to_hardlink) 141 return (open(arcn->name, O_TRUNC | O_EXCL | O_RDWR, 0)); 142 143 /* 144 * Create a temporary file name so that the file doesn't have partial 145 * contents while restoring. 146 */ 147 arcn->tmp_name = malloc(arcn->nlen + 8); 148 if (arcn->tmp_name == NULL) { 149 syswarn(1, errno, "Cannot malloc %d bytes", arcn->nlen + 8); 150 return -1; 151 } 152 if (xtmp_name != NULL) 153 abort(); 154 xtmp_name = arcn->tmp_name; 155 156 for (;;) { 157 /* 158 * try to create the temporary file we use to restore the 159 * contents info. if this fails, keep checking all the nodes 160 * in the path until chk_path() finds that it cannot fix 161 * anything further. if that happens we just give up. 162 */ 163 (void)snprintf(arcn->tmp_name, arcn->nlen + 8, "%s.XXXXXX", 164 arcn->name); 165 fd = mkstemp(arcn->tmp_name); 166 if (fd >= 0) 167 break; 168 oerrno = errno; 169 if (nodirs || chk_path(arcn->name,arcn->sb.st_uid,arcn->sb.st_gid) < 0) { 170 (void)fflush(listf); 171 syswarn(1, oerrno, "Cannot create %s", arcn->tmp_name); 172 xtmp_name = NULL; 173 free(arcn->tmp_name); 174 arcn->tmp_name = NULL; 175 return -1; 176 } 177 } 178 return fd; 179} 180 181/* 182 * file_close() 183 * Close file descriptor to a file just created by pax. Sets modes, 184 * ownership and times as required. 185 * Return: 186 * 0 for success, -1 for failure 187 */ 188 189void 190file_close(ARCHD *arcn, int fd) 191{ 192 char *tmp_name; 193 int res; 194 195 if (fd < 0) 196 return; 197 198 tmp_name = (arcn->tmp_name != NULL) ? arcn->tmp_name : arcn->name; 199 200 if (close(fd) < 0) 201 syswarn(0, errno, "Cannot close file descriptor on %s", 202 tmp_name); 203 204 /* 205 * set owner/groups first as this may strip off mode bits we want 206 * then set file permission modes. Then set file access and 207 * modification times. 208 */ 209 if (pids) 210 res = set_ids(tmp_name, arcn->sb.st_uid, arcn->sb.st_gid); 211 else 212 res = 0; 213 214 /* 215 * IMPORTANT SECURITY NOTE: 216 * if not preserving mode or we cannot set uid/gid, then PROHIBIT 217 * set uid/gid bits but restore the file modes (since mkstemp doesn't). 218 */ 219 if (!pmode || res) 220 arcn->sb.st_mode &= ~SETBITS(0); 221 if (pmode) 222 set_pmode(tmp_name, arcn->sb.st_mode); 223 else 224 set_pmode(tmp_name, 225 apply_umask((arcn->sb.st_mode & FILEBITS(0)))); 226 if (patime || pmtime) 227 set_ftime(tmp_name, arcn->sb.st_mtime, 228 arcn->sb.st_atime, 0, 0); 229 230 /* Did we write directly to the target file? */ 231 if (arcn->tmp_name == NULL) 232 return; 233 234 /* 235 * Finally, now the temp file is fully instantiated rename it to 236 * the desired file name. 237 */ 238 if (rename(tmp_name, arcn->name) < 0) { 239 syswarn(0, errno, "Cannot rename %s to %s", 240 tmp_name, arcn->name); 241 (void)unlink(tmp_name); 242 } 243 244#if HAVE_STRUCT_STAT_ST_FLAGS 245 if (pfflags && arcn->type != PAX_SLK) 246 set_chflags(arcn->name, arcn->sb.st_flags); 247#endif 248 249 free(arcn->tmp_name); 250 arcn->tmp_name = NULL; 251 xtmp_name = NULL; 252} 253 254/* 255 * lnk_creat() 256 * Create a hard link to arcn->ln_name from arcn->name. arcn->ln_name 257 * must exist; 258 * Return: 259 * 0 if ok, -1 otherwise 260 */ 261 262int 263lnk_creat(ARCHD *arcn, int *payload) 264{ 265 struct stat sb; 266 267 /* 268 * Check if this hardlink carries the "payload". In "cpio" archives 269 * it's usually the last record of a set of hardlinks which includes 270 * the contents of the file. 271 * 272 */ 273 *payload = S_ISREG(arcn->sb.st_mode) && 274 (arcn->sb.st_size > 0) && (arcn->sb.st_size <= arcn->skip); 275 276 /* 277 * We may be running as root, so we have to be sure that link target 278 * is not a directory, so we lstat and check. XXX: This is still racy. 279 */ 280 if (lstat(arcn->ln_name, &sb) != -1 && S_ISDIR(sb.st_mode)) { 281 tty_warn(1, "A hard link to the directory %s is not allowed", 282 arcn->ln_name); 283 return -1; 284 } 285 286 return mk_link(arcn->ln_name, &sb, arcn->name, 0); 287} 288 289/* 290 * cross_lnk() 291 * Create a hard link to arcn->org_name from arcn->name. Only used in copy 292 * with the -l flag. No warning or error if this does not succeed (we will 293 * then just create the file) 294 * Return: 295 * 1 if copy() should try to create this file node 296 * 0 if cross_lnk() ok, -1 for fatal flaw (like linking to self). 297 */ 298 299int 300cross_lnk(ARCHD *arcn) 301{ 302 /* 303 * try to make a link to original file (-l flag in copy mode). make 304 * sure we do not try to link to directories in case we are running as 305 * root (and it might succeed). 306 */ 307 if (arcn->type == PAX_DIR) 308 return 1; 309 return mk_link(arcn->org_name, &(arcn->sb), arcn->name, 1); 310} 311 312/* 313 * chk_same() 314 * In copy mode if we are not trying to make hard links between the src 315 * and destinations, make sure we are not going to overwrite ourselves by 316 * accident. This slows things down a little, but we have to protect all 317 * those people who make typing errors. 318 * Return: 319 * 1 the target does not exist, go ahead and copy 320 * 0 skip it file exists (-k) or may be the same as source file 321 */ 322 323int 324chk_same(ARCHD *arcn) 325{ 326 struct stat sb; 327 328 /* 329 * if file does not exist, return. if file exists and -k, skip it 330 * quietly 331 */ 332 if (lstat(arcn->name, &sb) < 0) 333 return 1; 334 if (kflag) 335 return 0; 336 337 /* 338 * better make sure the user does not have src == dest by mistake 339 */ 340 if ((arcn->sb.st_dev == sb.st_dev) && (arcn->sb.st_ino == sb.st_ino)) { 341 tty_warn(1, "Unable to copy %s, file would overwrite itself", 342 arcn->name); 343 return 0; 344 } 345 return 1; 346} 347 348/* 349 * mk_link() 350 * try to make a hard link between two files. if ign set, we do not 351 * complain. 352 * Return: 353 * 0 if successful (or we are done with this file but no error, such as 354 * finding the from file exists and the user has set -k). 355 * 1 when ign was set to indicates we could not make the link but we 356 * should try to copy/extract the file as that might work (and is an 357 * allowed option). -1 an error occurred. 358 */ 359 360static int 361mk_link(char *to, struct stat *to_sb, char *from, int ign) 362{ 363 struct stat sb; 364 int oerrno; 365 366 /* 367 * if from file exists, it has to be unlinked to make the link. If the 368 * file exists and -k is set, skip it quietly 369 */ 370 if (lstat(from, &sb) == 0) { 371 if (kflag) 372 return 0; 373 374 /* 375 * make sure it is not the same file, protect the user 376 */ 377 if ((to_sb->st_dev==sb.st_dev)&&(to_sb->st_ino == sb.st_ino)) { 378 tty_warn(1, "Cannot link file %s to itself", to); 379 return -1; 380 } 381 382 /* 383 * try to get rid of the file, based on the type 384 */ 385 if (S_ISDIR(sb.st_mode) && strcmp(from, ".") != 0) { 386 if (rmdir(from) < 0) { 387 syswarn(1, errno, "Cannot remove %s", from); 388 return -1; 389 } 390 } else if (unlink(from) < 0) { 391 if (!ign) { 392 syswarn(1, errno, "Cannot remove %s", from); 393 return -1; 394 } 395 return 1; 396 } 397 } 398 399 /* 400 * from file is gone (or did not exist), try to make the hard link. 401 * if it fails, check the path and try it again (if chk_path() says to 402 * try again) 403 */ 404 for (;;) { 405 if (link(to, from) == 0) 406 break; 407 oerrno = errno; 408 if (chk_path(from, to_sb->st_uid, to_sb->st_gid) == 0) 409 continue; 410 if (!ign) { 411 syswarn(1, oerrno, "Cannot link to %s from %s", to, 412 from); 413 return -1; 414 } 415 return 1; 416 } 417 418 /* 419 * all right the link was made 420 */ 421 return 0; 422} 423 424/* 425 * node_creat() 426 * create an entry in the file system (other than a file or hard link). 427 * If successful, sets uid/gid modes and times as required. 428 * Return: 429 * 0 if ok, -1 otherwise 430 */ 431 432int 433node_creat(ARCHD *arcn) 434{ 435 int res; 436 int ign = 0; 437 int oerrno; 438 int pass = 0; 439 mode_t file_mode; 440 struct stat sb; 441 char target[MAXPATHLEN]; 442 char *nm = arcn->name; 443 int len; 444 445 /* 446 * create node based on type, if that fails try to unlink the node and 447 * try again. finally check the path and try again. As noted in the 448 * file and link creation routines, this method seems to exhibit the 449 * best performance in general use workloads. 450 */ 451 file_mode = arcn->sb.st_mode & FILEBITS(arcn->type == PAX_DIR); 452 453 for (;;) { 454 switch (arcn->type) { 455 case PAX_DIR: 456 /* 457 * If -h (or -L) was given in tar-mode, follow the 458 * potential symlink chain before trying to create the 459 * directory. 460 */ 461 if (strcmp(NM_TAR, argv0) == 0 && Lflag) { 462 while (lstat(nm, &sb) == 0 && 463 S_ISLNK(sb.st_mode)) { 464 len = readlink(nm, target, 465 sizeof target - 1); 466 if (len == -1) { 467 syswarn(0, errno, 468 "cannot follow symlink %s " 469 "in chain for %s", 470 nm, arcn->name); 471 res = -1; 472 goto badlink; 473 } 474 target[len] = '\0'; 475 nm = target; 476 } 477 } 478 res = domkdir(nm, file_mode); 479badlink: 480 if (ign) 481 res = 0; 482 break; 483 case PAX_CHR: 484 file_mode |= S_IFCHR; 485 res = mknod(nm, file_mode, arcn->sb.st_rdev); 486 break; 487 case PAX_BLK: 488 file_mode |= S_IFBLK; 489 res = mknod(nm, file_mode, arcn->sb.st_rdev); 490 break; 491 case PAX_FIF: 492 res = mkfifo(nm, file_mode); 493 break; 494 case PAX_SCK: 495 /* 496 * Skip sockets, operation has no meaning under BSD 497 */ 498 tty_warn(0, 499 "%s skipped. Sockets cannot be copied or extracted", 500 nm); 501 return (-1); 502 case PAX_SLK: 503 res = symlink(arcn->ln_name, nm); 504 break; 505 case PAX_CTG: 506 case PAX_HLK: 507 case PAX_HRG: 508 case PAX_REG: 509 default: 510 /* 511 * we should never get here 512 */ 513 tty_warn(0, "%s has an unknown file type, skipping", 514 nm); 515 return (-1); 516 } 517 518 /* 519 * if we were able to create the node break out of the loop, 520 * otherwise try to unlink the node and try again. if that 521 * fails check the full path and try a final time. 522 */ 523 if (res == 0) 524 break; 525 526 /* 527 * we failed to make the node 528 */ 529 oerrno = errno; 530 switch (pass++) { 531 case 0: 532 if ((ign = unlnk_exist(nm, arcn->type)) < 0) 533 return (-1); 534 continue; 535 536 case 1: 537 if (nodirs || 538 chk_path(nm, arcn->sb.st_uid, 539 arcn->sb.st_gid) < 0) { 540 syswarn(1, oerrno, "Cannot create %s", nm); 541 return (-1); 542 } 543 continue; 544 } 545 546 /* 547 * it must be a file that exists but we can't create or 548 * remove, but we must avoid the infinite loop. 549 */ 550 break; 551 } 552 553 /* 554 * we were able to create the node. set uid/gid, modes and times 555 */ 556 if (pids) 557 res = set_ids(nm, arcn->sb.st_uid, arcn->sb.st_gid); 558 else 559 res = 0; 560 561 /* 562 * IMPORTANT SECURITY NOTE: 563 * if not preserving mode or we cannot set uid/gid, then PROHIBIT any 564 * set uid/gid bits 565 */ 566 if (!pmode || res) 567 arcn->sb.st_mode &= ~SETBITS(arcn->type == PAX_DIR); 568 if (pmode) 569 set_pmode(arcn->name, arcn->sb.st_mode); 570 571 if (arcn->type == PAX_DIR && strcmp(NM_CPIO, argv0) != 0) { 572 /* 573 * Dirs must be processed again at end of extract to set times 574 * and modes to agree with those stored in the archive. However 575 * to allow extract to continue, we may have to also set owner 576 * rights. This allows nodes in the archive that are children 577 * of this directory to be extracted without failure. Both time 578 * and modes will be fixed after the entire archive is read and 579 * before pax exits. 580 */ 581 if (access(nm, R_OK | W_OK | X_OK) < 0) { 582 if (lstat(nm, &sb) < 0) { 583 syswarn(0, errno,"Cannot access %s (stat)", 584 arcn->name); 585 set_pmode(nm,file_mode | S_IRWXU); 586 } else { 587 /* 588 * We have to add rights to the dir, so we make 589 * sure to restore the mode. The mode must be 590 * restored AS CREATED and not as stored if 591 * pmode is not set. 592 */ 593 set_pmode(nm, ((sb.st_mode & 594 FILEBITS(arcn->type == PAX_DIR)) | 595 S_IRWXU)); 596 if (!pmode) 597 arcn->sb.st_mode = sb.st_mode; 598 } 599 600 /* 601 * we have to force the mode to what was set here, 602 * since we changed it from the default as created. 603 */ 604 add_dir(nm, arcn->nlen, &(arcn->sb), 1); 605 } else if (pmode || patime || pmtime) 606 add_dir(nm, arcn->nlen, &(arcn->sb), 0); 607 } 608 609 if (patime || pmtime) 610 set_ftime(arcn->name, arcn->sb.st_mtime, 611 arcn->sb.st_atime, 0, (arcn->type == PAX_SLK) ? 1 : 0); 612 613#if HAVE_STRUCT_STAT_ST_FLAGS 614 if (pfflags && arcn->type != PAX_SLK) 615 set_chflags(arcn->name, arcn->sb.st_flags); 616#endif 617 return 0; 618} 619 620/* 621 * unlnk_exist() 622 * Remove node from file system with the specified name. We pass the type 623 * of the node that is going to replace it. When we try to create a 624 * directory and find that it already exists, we allow processing to 625 * continue as proper modes etc will always be set for it later on. 626 * Return: 627 * 0 is ok to proceed, no file with the specified name exists 628 * -1 we were unable to remove the node, or we should not remove it (-k) 629 * 1 we found a directory and we were going to create a directory. 630 */ 631 632int 633unlnk_exist(char *name, int type) 634{ 635 struct stat sb; 636 637 /* 638 * the file does not exist, or -k we are done 639 */ 640 if (lstat(name, &sb) < 0) 641 return 0; 642 if (kflag) 643 return -1; 644 645 if (S_ISDIR(sb.st_mode)) { 646 /* 647 * try to remove a directory, if it fails and we were going to 648 * create a directory anyway, tell the caller (return a 1). 649 * 650 * don't try to remove the directory if the name is "." 651 * otherwise later file/directory creation fails. 652 */ 653 if (strcmp(name, ".") == 0) 654 return 1; 655 if (rmdir(name) < 0) { 656 if (type == PAX_DIR) 657 return 1; 658 syswarn(1, errno, "Cannot remove directory %s", name); 659 return -1; 660 } 661 return 0; 662 } 663 664 /* 665 * try to get rid of all non-directory type nodes 666 */ 667 if (unlink(name) < 0) { 668 (void)fflush(listf); 669 syswarn(1, errno, "Cannot unlink %s", name); 670 return -1; 671 } 672 return 0; 673} 674 675/* 676 * chk_path() 677 * We were trying to create some kind of node in the file system and it 678 * failed. chk_path() makes sure the path up to the node exists and is 679 * writable. When we have to create a directory that is missing along the 680 * path somewhere, the directory we create will be set to the same 681 * uid/gid as the file has (when uid and gid are being preserved). 682 * NOTE: this routine is a real performance loss. It is only used as a 683 * last resort when trying to create entries in the file system. 684 * Return: 685 * -1 when it could find nothing it is allowed to fix. 686 * 0 otherwise 687 */ 688 689int 690chk_path(char *name, uid_t st_uid, gid_t st_gid) 691{ 692 char *spt = name; 693 struct stat sb; 694 int retval = -1; 695 696 /* 697 * watch out for paths with nodes stored directly in / (e.g. /bozo) 698 */ 699 if (*spt == '/') 700 ++spt; 701 702 for(;;) { 703 /* 704 * work forward from the first / and check each part of 705 * the path 706 */ 707 spt = strchr(spt, '/'); 708 if (spt == NULL) 709 break; 710 *spt = '\0'; 711 712 /* 713 * if it exists we assume it is a directory, it is not within 714 * the spec (at least it seems to read that way) to alter the 715 * file system for nodes NOT EXPLICITLY stored on the archive. 716 * If that assumption is changed, you would test the node here 717 * and figure out how to get rid of it (probably like some 718 * recursive unlink()) or fix up the directory permissions if 719 * required (do an access()). 720 */ 721 if (lstat(name, &sb) == 0) { 722 *(spt++) = '/'; 723 continue; 724 } 725 726 /* 727 * the path fails at this point, see if we can create the 728 * needed directory and continue on 729 */ 730 if (domkdir(name, S_IRWXU | S_IRWXG | S_IRWXO) == -1) { 731 *spt = '/'; 732 retval = -1; 733 break; 734 } 735 736 /* 737 * we were able to create the directory. We will tell the 738 * caller that we found something to fix, and it is ok to try 739 * and create the node again. 740 */ 741 retval = 0; 742 if (pids) 743 (void)set_ids(name, st_uid, st_gid); 744 745 /* 746 * make sure the user doesn't have some strange umask that 747 * causes this newly created directory to be unusable. We fix 748 * the modes and restore them back to the creation default at 749 * the end of pax 750 */ 751 if ((access(name, R_OK | W_OK | X_OK) < 0) && 752 (lstat(name, &sb) == 0)) { 753 set_pmode(name, ((sb.st_mode & FILEBITS(0)) | 754 S_IRWXU)); 755 add_dir(name, spt - name, &sb, 1); 756 } 757 *(spt++) = '/'; 758 continue; 759 } 760 /* 761 * We perform one final check here, because if someone else 762 * created the directory in parallel with us, we might return 763 * the wrong error code, even if the directory exists now. 764 */ 765 if (retval == -1 && stat(name, &sb) == 0 && S_ISDIR(sb.st_mode)) 766 retval = 0; 767 return retval; 768} 769 770/* 771 * set_ftime() 772 * Set the access time and modification time for a named file. If frc 773 * is non-zero we force these times to be set even if the user did not 774 * request access and/or modification time preservation (this is also 775 * used by -t to reset access times). 776 * When ign is zero, only those times the user has asked for are set, the 777 * other ones are left alone. We do not assume the un-documented feature 778 * of many utimes() implementations that consider a 0 time value as a do 779 * not set request. 780 * 781 * Unfortunately, there are systems where lutimes() is present but does 782 * not work on some filesystem types, which cannot be detected at 783 * compile time. This requires passing down symlink knowledge into 784 * this function to obtain correct operation. Linux with XFS is one 785 * example of such a system. 786 */ 787 788void 789set_ftime(char *fnm, time_t mtime, time_t atime, int frc, int slk) 790{ 791 struct timeval tv[2]; 792 struct stat sb; 793 794 tv[0].tv_sec = (long)atime; 795 tv[0].tv_usec = 0; 796 tv[1].tv_sec = (long)mtime; 797 tv[1].tv_usec = 0; 798 if (!frc && (!patime || !pmtime)) { 799 /* 800 * if we are not forcing, only set those times the user wants 801 * set. We get the current values of the times if we need them. 802 */ 803 if (lstat(fnm, &sb) == 0) { 804#if BSD4_4 && !HAVE_NBTOOL_CONFIG_H 805 if (!patime) 806 TIMESPEC_TO_TIMEVAL(&tv[0], &sb.st_atimespec); 807 if (!pmtime) 808 TIMESPEC_TO_TIMEVAL(&tv[1], &sb.st_mtimespec); 809#else 810 if (!patime) 811 tv[0].tv_sec = sb.st_atime; 812 if (!pmtime) 813 tv[1].tv_sec = sb.st_mtime; 814#endif 815 } else 816 syswarn(0, errno, "Cannot obtain file stats %s", fnm); 817 } 818 819 /* 820 * set the times 821 */ 822#if HAVE_LUTIMES 823 if (lutimes(fnm, tv) == 0) 824 return; 825 if (errno != ENOSYS) /* XXX linux: lutimes is per-FS */ 826 goto bad; 827#endif 828 if (slk) 829 return; 830 if (utimes(fnm, tv) == -1) 831 goto bad; 832 return; 833bad: 834 syswarn(1, errno, "Access/modification time set failed on: %s", fnm); 835} 836 837/* 838 * set_ids() 839 * set the uid and gid of a file system node 840 * Return: 841 * 0 when set, -1 on failure 842 */ 843 844int 845set_ids(char *fnm, uid_t uid, gid_t gid) 846{ 847 if (geteuid() == 0) 848 if (lchown(fnm, uid, gid)) { 849 (void)fflush(listf); 850 syswarn(1, errno, "Cannot set file uid/gid of %s", 851 fnm); 852 return -1; 853 } 854 return 0; 855} 856 857/* 858 * set_pmode() 859 * Set file access mode 860 */ 861 862void 863set_pmode(char *fnm, mode_t mode) 864{ 865 mode &= A_BITS; 866 if (lchmod(fnm, mode)) { 867 (void)fflush(listf); 868 syswarn(1, errno, "Cannot set permissions on %s", fnm); 869 } 870 return; 871} 872 873/* 874 * set_chflags() 875 * Set 4.4BSD file flags 876 */ 877void 878set_chflags(char *fnm, u_int32_t flags) 879{ 880 881#if 0 882 if (chflags(fnm, flags) < 0 && errno != EOPNOTSUPP) 883 syswarn(1, errno, "Cannot set file flags on %s", fnm); 884#endif 885 return; 886} 887 888/* 889 * file_write() 890 * Write/copy a file (during copy or archive extract). This routine knows 891 * how to copy files with lseek holes in it. (Which are read as file 892 * blocks containing all 0's but do not have any file blocks associated 893 * with the data). Typical examples of these are files created by dbm 894 * variants (.pag files). While the file size of these files are huge, the 895 * actual storage is quite small (the files are sparse). The problem is 896 * the holes read as all zeros so are probably stored on the archive that 897 * way (there is no way to determine if the file block is really a hole, 898 * we only know that a file block of all zero's can be a hole). 899 * At this writing, no major archive format knows how to archive files 900 * with holes. However, on extraction (or during copy, -rw) we have to 901 * deal with these files. Without detecting the holes, the files can 902 * consume a lot of file space if just written to disk. This replacement 903 * for write when passed the basic allocation size of a file system block, 904 * uses lseek whenever it detects the input data is all 0 within that 905 * file block. In more detail, the strategy is as follows: 906 * While the input is all zero keep doing an lseek. Keep track of when we 907 * pass over file block boundaries. Only write when we hit a non zero 908 * input. once we have written a file block, we continue to write it to 909 * the end (we stop looking at the input). When we reach the start of the 910 * next file block, start checking for zero blocks again. Working on file 911 * block boundaries significantly reduces the overhead when copying files 912 * that are NOT very sparse. This overhead (when compared to a write) is 913 * almost below the measurement resolution on many systems. Without it, 914 * files with holes cannot be safely copied. It does has a side effect as 915 * it can put holes into files that did not have them before, but that is 916 * not a problem since the file contents are unchanged (in fact it saves 917 * file space). (Except on paging files for diskless clients. But since we 918 * cannot determine one of those file from here, we ignore them). If this 919 * ever ends up on a system where CTG files are supported and the holes 920 * are not desired, just do a conditional test in those routines that 921 * call file_write() and have it call write() instead. BEFORE CLOSING THE 922 * FILE, make sure to call file_flush() when the last write finishes with 923 * an empty block. A lot of file systems will not create an lseek hole at 924 * the end. In this case we drop a single 0 at the end to force the 925 * trailing 0's in the file. 926 * ---Parameters--- 927 * rem: how many bytes left in this file system block 928 * isempt: have we written to the file block yet (is it empty) 929 * sz: basic file block allocation size 930 * cnt: number of bytes on this write 931 * str: buffer to write 932 * Return: 933 * number of bytes written, -1 on write (or lseek) error. 934 */ 935 936int 937file_write(int fd, char *str, int cnt, int *rem, int *isempt, int sz, 938 char *name) 939{ 940 char *pt; 941 char *end; 942 int wcnt; 943 char *st = str; 944 char **strp; 945 size_t *lenp; 946 947 /* 948 * while we have data to process 949 */ 950 while (cnt) { 951 if (!*rem) { 952 /* 953 * We are now at the start of file system block again 954 * (or what we think one is...). start looking for 955 * empty blocks again 956 */ 957 *isempt = 1; 958 *rem = sz; 959 } 960 961 /* 962 * only examine up to the end of the current file block or 963 * remaining characters to write, whatever is smaller 964 */ 965 wcnt = MIN(cnt, *rem); 966 cnt -= wcnt; 967 *rem -= wcnt; 968 if (*isempt) { 969 /* 970 * have not written to this block yet, so we keep 971 * looking for zero's 972 */ 973 pt = st; 974 end = st + wcnt; 975 976 /* 977 * look for a zero filled buffer 978 */ 979 while ((pt < end) && (*pt == '\0')) 980 ++pt; 981 982 if (pt == end) { 983 /* 984 * skip, buf is empty so far 985 */ 986 if (fd > -1 && 987 lseek(fd, (off_t)wcnt, SEEK_CUR) < 0) { 988 syswarn(1, errno, "File seek on %s", 989 name); 990 return -1; 991 } 992 st = pt; 993 continue; 994 } 995 /* 996 * drat, the buf is not zero filled 997 */ 998 *isempt = 0; 999 } 1000 1001 /* 1002 * have non-zero data in this file system block, have to write 1003 */ 1004 switch (fd) { 1005 case -PAX_GLF: 1006 strp = &gnu_name_string; 1007 lenp = &gnu_name_length; 1008 break; 1009 case -PAX_GLL: 1010 strp = &gnu_link_string; 1011 lenp = &gnu_link_length; 1012 break; 1013 default: 1014 strp = NULL; 1015 lenp = NULL; 1016 break; 1017 } 1018 if (strp) { 1019 char *nstr = *strp ? realloc(*strp, *lenp + wcnt + 1) : 1020 malloc(wcnt + 1); 1021 if (nstr == NULL) { 1022 tty_warn(1, "Out of memory"); 1023 return -1; 1024 } 1025 (void)strlcpy(&nstr[*lenp], st, wcnt + 1); 1026 *strp = nstr; 1027 *lenp += wcnt; 1028 } else if (xwrite(fd, st, wcnt) != wcnt) { 1029 syswarn(1, errno, "Failed write to file %s", name); 1030 return -1; 1031 } 1032 st += wcnt; 1033 } 1034 return st - str; 1035} 1036 1037/* 1038 * file_flush() 1039 * when the last file block in a file is zero, many file systems will not 1040 * let us create a hole at the end. To get the last block with zeros, we 1041 * write the last BYTE with a zero (back up one byte and write a zero). 1042 */ 1043 1044void 1045file_flush(int fd, char *fname, int isempt) 1046{ 1047 static char blnk[] = "\0"; 1048 1049 /* 1050 * silly test, but make sure we are only called when the last block is 1051 * filled with all zeros. 1052 */ 1053 if (!isempt) 1054 return; 1055 1056 /* 1057 * move back one byte and write a zero 1058 */ 1059 if (lseek(fd, (off_t)-1, SEEK_CUR) < 0) { 1060 syswarn(1, errno, "Failed seek on file %s", fname); 1061 return; 1062 } 1063 1064 if (write_with_restart(fd, blnk, 1) < 0) 1065 syswarn(1, errno, "Failed write to file %s", fname); 1066 return; 1067} 1068 1069/* 1070 * rdfile_close() 1071 * close a file we have been reading (to copy or archive). If we have to 1072 * reset access time (tflag) do so (the times are stored in arcn). 1073 */ 1074 1075void 1076rdfile_close(ARCHD *arcn, int *fd) 1077{ 1078 /* 1079 * make sure the file is open 1080 */ 1081 if (*fd < 0) 1082 return; 1083 1084 (void)close(*fd); 1085 *fd = -1; 1086 if (!tflag) 1087 return; 1088 1089 /* 1090 * user wants last access time reset 1091 */ 1092 set_ftime(arcn->org_name, arcn->sb.st_mtime, arcn->sb.st_atime, 1, 0); 1093 return; 1094} 1095 1096/* 1097 * set_crc() 1098 * read a file to calculate its crc. This is a real drag. Archive formats 1099 * that have this, end up reading the file twice (we have to write the 1100 * header WITH the crc before writing the file contents. Oh well... 1101 * Return: 1102 * 0 if was able to calculate the crc, -1 otherwise 1103 */ 1104 1105int 1106set_crc(ARCHD *arcn, int fd) 1107{ 1108 int i; 1109 int res; 1110 off_t cpcnt = 0L; 1111 u_long size; 1112 unsigned long crc = 0L; 1113 char tbuf[FILEBLK]; 1114 struct stat sb; 1115 1116 if (fd < 0) { 1117 /* 1118 * hmm, no fd, should never happen. well no crc then. 1119 */ 1120 arcn->crc = 0L; 1121 return 0; 1122 } 1123 1124 if ((size = (u_long)arcn->sb.st_blksize) > (u_long)sizeof(tbuf)) 1125 size = (u_long)sizeof(tbuf); 1126 1127 /* 1128 * read all the bytes we think that there are in the file. If the user 1129 * is trying to archive an active file, forget this file. 1130 */ 1131 for(;;) { 1132 if ((res = read(fd, tbuf, size)) <= 0) 1133 break; 1134 cpcnt += res; 1135 for (i = 0; i < res; ++i) 1136 crc += (tbuf[i] & 0xff); 1137 } 1138 1139 /* 1140 * safety check. we want to avoid archiving files that are active as 1141 * they can create inconsistent archive copies. 1142 */ 1143 if (cpcnt != arcn->sb.st_size) 1144 tty_warn(1, "File changed size %s", arcn->org_name); 1145 else if (fstat(fd, &sb) < 0) 1146 syswarn(1, errno, "Failed stat on %s", arcn->org_name); 1147 else if (arcn->sb.st_mtime != sb.st_mtime) 1148 tty_warn(1, "File %s was modified during read", arcn->org_name); 1149 else if (lseek(fd, (off_t)0L, SEEK_SET) < 0) 1150 syswarn(1, errno, "File rewind failed on: %s", arcn->org_name); 1151 else { 1152 arcn->crc = crc; 1153 return 0; 1154 } 1155 return -1; 1156} 1157