file_subs.c revision 1.41.2.7
1/* $NetBSD: file_subs.c,v 1.41.2.7 2004/08/25 02:44:45 jmc 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 1.41.2.7 2004/08/25 02:44:45 jmc 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 87/* 88 * file_creat() 89 * Create and open a file. 90 * Return: 91 * file descriptor or -1 for failure 92 */ 93 94int 95file_creat(ARCHD *arcn, int write_to_hardlink) 96{ 97 int fd = -1; 98 int oerrno; 99 100 /* 101 * Some horribly busted tar implementations, have directory nodes 102 * that end in a /, but they mark as files. Compensate for that 103 * by not creating a directory node at this point, but a file node, 104 * and not creating the temp file. 105 */ 106 if (arcn->nlen != 0 && arcn->name[arcn->nlen - 1] == '/') { 107 if (!warn_broken) { 108 tty_warn(0, "Archive was created with a broken tar;" 109 " file `%s' is a directory, but marked as plain.", 110 arcn->name); 111 warn_broken = 1; 112 } 113 return -1; 114 } 115 116 /* 117 * In "cpio" archives it's usually the last record of a set of 118 * hardlinks which includes the contents of the file. We cannot 119 * use a tempory file in that case because we couldn't link it 120 * with the existing other hardlinks after restoring the contents 121 * to it. And it's also useless to create the hardlink under a 122 * temporary name because the other hardlinks would have partial 123 * contents while restoring. 124 */ 125 if (write_to_hardlink) 126 return (open(arcn->name, O_TRUNC | O_EXCL | O_RDWR, 0)); 127 128 /* 129 * Create a temporary file name so that the file doesn't have partial 130 * contents while restoring. 131 */ 132 arcn->tmp_name = malloc(arcn->nlen + 8); 133 if (arcn->tmp_name == NULL) { 134 syswarn(1, errno, "Cannot malloc %d bytes", arcn->nlen + 8); 135 return(-1); 136 } 137 if (xtmp_name != NULL) 138 abort(); 139 xtmp_name = arcn->tmp_name; 140 141 for (;;) { 142 /* 143 * try to create the temporary file we use to restore the 144 * contents info. if this fails, keep checking all the nodes 145 * in the path until chk_path() finds that it cannot fix 146 * anything further. if that happens we just give up. 147 */ 148 (void)snprintf(arcn->tmp_name, arcn->nlen + 8, "%s.XXXXXX", 149 arcn->name); 150 fd = mkstemp(arcn->tmp_name); 151 if (fd >= 0) 152 break; 153 oerrno = errno; 154 if (nodirs || chk_path(arcn->name,arcn->sb.st_uid,arcn->sb.st_gid) < 0) { 155 (void)fflush(listf); 156 syswarn(1, oerrno, "Cannot create %s", arcn->tmp_name); 157 xtmp_name = NULL; 158 free(arcn->tmp_name); 159 arcn->tmp_name = NULL; 160 return(-1); 161 } 162 } 163 return(fd); 164} 165 166/* 167 * file_close() 168 * Close file descriptor to a file just created by pax. Sets modes, 169 * ownership and times as required. 170 * Return: 171 * 0 for success, -1 for failure 172 */ 173 174void 175file_close(ARCHD *arcn, int fd) 176{ 177 char *tmp_name; 178 int res; 179 180 if (fd < 0) 181 return; 182 183 tmp_name = (arcn->tmp_name != NULL) ? arcn->tmp_name : arcn->name; 184 185 if (close(fd) < 0) 186 syswarn(0, errno, "Cannot close file descriptor on %s", 187 tmp_name); 188 189 /* 190 * set owner/groups first as this may strip off mode bits we want 191 * then set file permission modes. Then set file access and 192 * modification times. 193 */ 194 if (pids) 195 res = set_ids(tmp_name, arcn->sb.st_uid, arcn->sb.st_gid); 196 else 197 res = 0; 198 199 /* 200 * IMPORTANT SECURITY NOTE: 201 * if not preserving mode or we cannot set uid/gid, then PROHIBIT 202 * set uid/gid bits but restore the file modes (since mkstemp doesn't). 203 */ 204 if (!pmode || res) 205 arcn->sb.st_mode &= ~SETBITS(0); 206 if (pmode) 207 set_pmode(tmp_name, arcn->sb.st_mode); 208 else 209 set_pmode(tmp_name, arcn->sb.st_mode & FILEBITS(0)); 210 if (patime || pmtime) 211 set_ftime(tmp_name, arcn->sb.st_mtime, arcn->sb.st_atime, 0); 212 213 /* Did we write directly to the target file? */ 214 if (arcn->tmp_name == NULL) 215 return; 216 217 /* 218 * Finally, now the temp file is fully instantiated rename it to 219 * the desired file name. 220 */ 221 if (rename(tmp_name, arcn->name) < 0) { 222 syswarn(0, errno, "Cannot rename %s to %s", 223 tmp_name, arcn->name); 224 (void)unlink(tmp_name); 225 } 226 227#if HAVE_STRUCT_STAT_ST_FLAGS 228 if (pfflags && arcn->type != PAX_SLK) 229 set_chflags(arcn->name, arcn->sb.st_flags); 230#endif 231 232 free(arcn->tmp_name); 233 arcn->tmp_name = NULL; 234 xtmp_name = NULL; 235} 236 237/* 238 * lnk_creat() 239 * Create a hard link to arcn->ln_name from arcn->name. arcn->ln_name 240 * must exist; 241 * Return: 242 * 0 if ok, -1 otherwise 243 */ 244 245int 246lnk_creat(ARCHD *arcn, int *payload) 247{ 248 struct stat sb; 249 250 /* 251 * Check if this hardlink carries the "payload". In "cpio" archives 252 * it's usually the last record of a set of hardlinks which includes 253 * the contents of the file. 254 * 255 */ 256 *payload = S_ISREG(arcn->sb.st_mode) && 257 (arcn->sb.st_size > 0) && (arcn->sb.st_size <= arcn->skip); 258 259 /* 260 * We may be running as root, so we have to be sure that link target 261 * is not a directory, so we lstat and check 262 */ 263 if (lstat(arcn->ln_name, &sb) < 0) { 264 syswarn(1, errno, "Cannot link to %s from %s", arcn->ln_name, 265 arcn->name); 266 return(-1); 267 } 268 269 if (S_ISDIR(sb.st_mode)) { 270 tty_warn(1, "A hard link to the directory %s is not allowed", 271 arcn->ln_name); 272 return(-1); 273 } 274 275 return(mk_link(arcn->ln_name, &sb, arcn->name, 0)); 276} 277 278/* 279 * cross_lnk() 280 * Create a hard link to arcn->org_name from arcn->name. Only used in copy 281 * with the -l flag. No warning or error if this does not succeed (we will 282 * then just create the file) 283 * Return: 284 * 1 if copy() should try to create this file node 285 * 0 if cross_lnk() ok, -1 for fatal flaw (like linking to self). 286 */ 287 288int 289cross_lnk(ARCHD *arcn) 290{ 291 /* 292 * try to make a link to original file (-l flag in copy mode). make 293 * sure we do not try to link to directories in case we are running as 294 * root (and it might succeed). 295 */ 296 if (arcn->type == PAX_DIR) 297 return(1); 298 return(mk_link(arcn->org_name, &(arcn->sb), arcn->name, 1)); 299} 300 301/* 302 * chk_same() 303 * In copy mode if we are not trying to make hard links between the src 304 * and destinations, make sure we are not going to overwrite ourselves by 305 * accident. This slows things down a little, but we have to protect all 306 * those people who make typing errors. 307 * Return: 308 * 1 the target does not exist, go ahead and copy 309 * 0 skip it file exists (-k) or may be the same as source file 310 */ 311 312int 313chk_same(ARCHD *arcn) 314{ 315 struct stat sb; 316 317 /* 318 * if file does not exist, return. if file exists and -k, skip it 319 * quietly 320 */ 321 if (lstat(arcn->name, &sb) < 0) 322 return(1); 323 if (kflag) 324 return(0); 325 326 /* 327 * better make sure the user does not have src == dest by mistake 328 */ 329 if ((arcn->sb.st_dev == sb.st_dev) && (arcn->sb.st_ino == sb.st_ino)) { 330 tty_warn(1, "Unable to copy %s, file would overwrite itself", 331 arcn->name); 332 return(0); 333 } 334 return(1); 335} 336 337/* 338 * mk_link() 339 * try to make a hard link between two files. if ign set, we do not 340 * complain. 341 * Return: 342 * 0 if successful (or we are done with this file but no error, such as 343 * finding the from file exists and the user has set -k). 344 * 1 when ign was set to indicates we could not make the link but we 345 * should try to copy/extract the file as that might work (and is an 346 * allowed option). -1 an error occurred. 347 */ 348 349static int 350mk_link(char *to, struct stat *to_sb, char *from, int ign) 351{ 352 struct stat sb; 353 int oerrno; 354 355 /* 356 * if from file exists, it has to be unlinked to make the link. If the 357 * file exists and -k is set, skip it quietly 358 */ 359 if (lstat(from, &sb) == 0) { 360 if (kflag) 361 return(0); 362 363 /* 364 * make sure it is not the same file, protect the user 365 */ 366 if ((to_sb->st_dev==sb.st_dev)&&(to_sb->st_ino == sb.st_ino)) { 367 tty_warn(1, "Cannot link file %s to itself", to); 368 return(-1); 369 } 370 371 /* 372 * try to get rid of the file, based on the type 373 */ 374 if (S_ISDIR(sb.st_mode) && strcmp(from, ".") != 0) { 375 if (rmdir(from) < 0) { 376 syswarn(1, errno, "Cannot remove %s", from); 377 return(-1); 378 } 379 } else if (unlink(from) < 0) { 380 if (!ign) { 381 syswarn(1, errno, "Cannot remove %s", from); 382 return(-1); 383 } 384 return(1); 385 } 386 } 387 388 /* 389 * from file is gone (or did not exist), try to make the hard link. 390 * if it fails, check the path and try it again (if chk_path() says to 391 * try again) 392 */ 393 for (;;) { 394 if (link(to, from) == 0) 395 break; 396 oerrno = errno; 397 if (chk_path(from, to_sb->st_uid, to_sb->st_gid) == 0) 398 continue; 399 if (!ign) { 400 syswarn(1, oerrno, "Cannot link to %s from %s", to, 401 from); 402 return(-1); 403 } 404 return(1); 405 } 406 407 /* 408 * all right the link was made 409 */ 410 return(0); 411} 412 413/* 414 * node_creat() 415 * create an entry in the file system (other than a file or hard link). 416 * If successful, sets uid/gid modes and times as required. 417 * Return: 418 * 0 if ok, -1 otherwise 419 */ 420 421int 422node_creat(ARCHD *arcn) 423{ 424 int res; 425 int ign = 0; 426 int oerrno; 427 int pass = 0; 428 mode_t file_mode; 429 struct stat sb; 430 char target[MAXPATHLEN]; 431 char *nm = arcn->name; 432 int len; 433 434 /* 435 * create node based on type, if that fails try to unlink the node and 436 * try again. finally check the path and try again. As noted in the 437 * file and link creation routines, this method seems to exhibit the 438 * best performance in general use workloads. 439 */ 440 file_mode = arcn->sb.st_mode & FILEBITS(arcn->type == PAX_DIR); 441 442 for (;;) { 443 switch (arcn->type) { 444 case PAX_DIR: 445 /* 446 * If -h (or -L) was given in tar-mode, follow the 447 * potential symlink chain before trying to create the 448 * directory. 449 */ 450 if (strcmp(NM_TAR, argv0) == 0 && Lflag) { 451 while (lstat(nm, &sb) == 0 && 452 S_ISLNK(sb.st_mode)) { 453 len = readlink(nm, target, 454 sizeof target - 1); 455 if (len == -1) { 456 syswarn(0, errno, 457 "cannot follow symlink %s " 458 "in chain for %s", 459 nm, arcn->name); 460 res = -1; 461 goto badlink; 462 } 463 target[len] = '\0'; 464 nm = target; 465 } 466 } 467 res = mkdir(nm, file_mode); 468 469badlink: 470 if (ign) 471 res = 0; 472 break; 473 case PAX_CHR: 474 file_mode |= S_IFCHR; 475 res = mknod(nm, file_mode, arcn->sb.st_rdev); 476 break; 477 case PAX_BLK: 478 file_mode |= S_IFBLK; 479 res = mknod(nm, file_mode, arcn->sb.st_rdev); 480 break; 481 case PAX_FIF: 482 res = mkfifo(nm, file_mode); 483 break; 484 case PAX_SCK: 485 /* 486 * Skip sockets, operation has no meaning under BSD 487 */ 488 tty_warn(0, 489 "%s skipped. Sockets cannot be copied or extracted", 490 nm); 491 return (-1); 492 case PAX_SLK: 493 res = symlink(arcn->ln_name, nm); 494 break; 495 case PAX_CTG: 496 case PAX_HLK: 497 case PAX_HRG: 498 case PAX_REG: 499 default: 500 /* 501 * we should never get here 502 */ 503 tty_warn(0, "%s has an unknown file type, skipping", 504 nm); 505 return (-1); 506 } 507 508 /* 509 * if we were able to create the node break out of the loop, 510 * otherwise try to unlink the node and try again. if that 511 * fails check the full path and try a final time. 512 */ 513 if (res == 0) 514 break; 515 516 /* 517 * we failed to make the node 518 */ 519 oerrno = errno; 520 switch (pass++) { 521 case 0: 522 if ((ign = unlnk_exist(nm, arcn->type)) < 0) 523 return (-1); 524 continue; 525 526 case 1: 527 if (nodirs || 528 chk_path(nm, arcn->sb.st_uid, 529 arcn->sb.st_gid) < 0) { 530 syswarn(1, oerrno, "Cannot create %s", nm); 531 return (-1); 532 } 533 continue; 534 } 535 536 /* 537 * it must be a file that exists but we can't create or 538 * remove, but we must avoid the infinite loop. 539 */ 540 break; 541 } 542 543 /* 544 * we were able to create the node. set uid/gid, modes and times 545 */ 546 if (pids) 547 res = set_ids(nm, arcn->sb.st_uid, arcn->sb.st_gid); 548 else 549 res = 0; 550 551 /* 552 * IMPORTANT SECURITY NOTE: 553 * if not preserving mode or we cannot set uid/gid, then PROHIBIT any 554 * set uid/gid bits 555 */ 556 if (!pmode || res) 557 arcn->sb.st_mode &= ~SETBITS(arcn->type == PAX_DIR); 558 if (pmode) 559 set_pmode(arcn->name, arcn->sb.st_mode); 560 561 if (arcn->type == PAX_DIR && strcmp(NM_CPIO, argv0) != 0) { 562 /* 563 * Dirs must be processed again at end of extract to set times 564 * and modes to agree with those stored in the archive. However 565 * to allow extract to continue, we may have to also set owner 566 * rights. This allows nodes in the archive that are children 567 * of this directory to be extracted without failure. Both time 568 * and modes will be fixed after the entire archive is read and 569 * before pax exits. 570 */ 571 if (access(nm, R_OK | W_OK | X_OK) < 0) { 572 if (lstat(nm, &sb) < 0) { 573 syswarn(0, errno,"Cannot access %s (stat)", 574 arcn->name); 575 set_pmode(nm,file_mode | S_IRWXU); 576 } else { 577 /* 578 * We have to add rights to the dir, so we make 579 * sure to restore the mode. The mode must be 580 * restored AS CREATED and not as stored if 581 * pmode is not set. 582 */ 583 set_pmode(nm, ((sb.st_mode & 584 FILEBITS(arcn->type == PAX_DIR)) | 585 S_IRWXU)); 586 if (!pmode) 587 arcn->sb.st_mode = sb.st_mode; 588 } 589 590 /* 591 * we have to force the mode to what was set here, 592 * since we changed it from the default as created. 593 */ 594 add_dir(nm, arcn->nlen, &(arcn->sb), 1); 595 } else if (pmode || patime || pmtime) 596 add_dir(nm, arcn->nlen, &(arcn->sb), 0); 597 } 598 599#if HAVE_LUTIMES 600 if (patime || pmtime) 601#else 602 if ((patime || pmtime) && arcn->type != PAX_SLK) 603#endif 604 set_ftime(arcn->name, arcn->sb.st_mtime, arcn->sb.st_atime, 0); 605 606#if HAVE_STRUCT_STAT_ST_FLAGS 607 if (pfflags && arcn->type != PAX_SLK) 608 set_chflags(arcn->name, arcn->sb.st_flags); 609#endif 610 return(0); 611} 612 613/* 614 * unlnk_exist() 615 * Remove node from file system with the specified name. We pass the type 616 * of the node that is going to replace it. When we try to create a 617 * directory and find that it already exists, we allow processing to 618 * continue as proper modes etc will always be set for it later on. 619 * Return: 620 * 0 is ok to proceed, no file with the specified name exists 621 * -1 we were unable to remove the node, or we should not remove it (-k) 622 * 1 we found a directory and we were going to create a directory. 623 */ 624 625int 626unlnk_exist(char *name, int type) 627{ 628 struct stat sb; 629 630 /* 631 * the file does not exist, or -k we are done 632 */ 633 if (lstat(name, &sb) < 0) 634 return(0); 635 if (kflag) 636 return(-1); 637 638 if (S_ISDIR(sb.st_mode)) { 639 /* 640 * try to remove a directory, if it fails and we were going to 641 * create a directory anyway, tell the caller (return a 1). 642 * 643 * don't try to remove the directory if the name is "." 644 * otherwise later file/directory creation fails. 645 */ 646 if (strcmp(name, ".") == 0) 647 return(1); 648 if (rmdir(name) < 0) { 649 if (type == PAX_DIR) 650 return(1); 651 syswarn(1, errno, "Cannot remove directory %s", name); 652 return(-1); 653 } 654 return(0); 655 } 656 657 /* 658 * try to get rid of all non-directory type nodes 659 */ 660 if (unlink(name) < 0) { 661 (void)fflush(listf); 662 syswarn(1, errno, "Cannot unlink %s", name); 663 return(-1); 664 } 665 return(0); 666} 667 668/* 669 * chk_path() 670 * We were trying to create some kind of node in the file system and it 671 * failed. chk_path() makes sure the path up to the node exists and is 672 * writable. When we have to create a directory that is missing along the 673 * path somewhere, the directory we create will be set to the same 674 * uid/gid as the file has (when uid and gid are being preserved). 675 * NOTE: this routine is a real performance loss. It is only used as a 676 * last resort when trying to create entries in the file system. 677 * Return: 678 * -1 when it could find nothing it is allowed to fix. 679 * 0 otherwise 680 */ 681 682int 683chk_path(char *name, uid_t st_uid, gid_t st_gid) 684{ 685 char *spt = name; 686 struct stat sb; 687 int retval = -1; 688 689 /* 690 * watch out for paths with nodes stored directly in / (e.g. /bozo) 691 */ 692 if (*spt == '/') 693 ++spt; 694 695 for(;;) { 696 /* 697 * work forward from the first / and check each part of 698 * the path 699 */ 700 spt = strchr(spt, '/'); 701 if (spt == NULL) 702 break; 703 *spt = '\0'; 704 705 /* 706 * if it exists we assume it is a directory, it is not within 707 * the spec (at least it seems to read that way) to alter the 708 * file system for nodes NOT EXPLICITLY stored on the archive. 709 * If that assumption is changed, you would test the node here 710 * and figure out how to get rid of it (probably like some 711 * recursive unlink()) or fix up the directory permissions if 712 * required (do an access()). 713 */ 714 if (lstat(name, &sb) == 0) { 715 *(spt++) = '/'; 716 continue; 717 } 718 719 /* 720 * the path fails at this point, see if we can create the 721 * needed directory and continue on 722 */ 723 if (mkdir(name, S_IRWXU | S_IRWXG | S_IRWXO) < 0) { 724 *spt = '/'; 725 retval = -1; 726 break; 727 } 728 729 /* 730 * we were able to create the directory. We will tell the 731 * caller that we found something to fix, and it is ok to try 732 * and create the node again. 733 */ 734 retval = 0; 735 if (pids) 736 (void)set_ids(name, st_uid, st_gid); 737 738 /* 739 * make sure the user doesn't have some strange umask that 740 * causes this newly created directory to be unusable. We fix 741 * the modes and restore them back to the creation default at 742 * the end of pax 743 */ 744 if ((access(name, R_OK | W_OK | X_OK) < 0) && 745 (lstat(name, &sb) == 0)) { 746 set_pmode(name, ((sb.st_mode & FILEBITS(0)) | 747 S_IRWXU)); 748 add_dir(name, spt - name, &sb, 1); 749 } 750 *(spt++) = '/'; 751 continue; 752 } 753 return(retval); 754} 755 756/* 757 * set_ftime() 758 * Set the access time and modification time for a named file. If frc 759 * is non-zero we force these times to be set even if the user did not 760 * request access and/or modification time preservation (this is also 761 * used by -t to reset access times). 762 * When ign is zero, only those times the user has asked for are set, the 763 * other ones are left alone. We do not assume the un-documented feature 764 * of many utimes() implementations that consider a 0 time value as a do 765 * not set request. 766 */ 767 768void 769set_ftime(char *fnm, time_t mtime, time_t atime, int frc) 770{ 771 struct timeval tv[2]; 772 struct stat sb; 773 774 tv[0].tv_sec = (long)atime; 775 tv[0].tv_usec = 0; 776 tv[1].tv_sec = (long)mtime; 777 tv[1].tv_usec = 0; 778 if (!frc && (!patime || !pmtime)) { 779 /* 780 * if we are not forcing, only set those times the user wants 781 * set. We get the current values of the times if we need them. 782 */ 783 if (lstat(fnm, &sb) == 0) { 784#if BSD4_4 && !HAVE_NBTOOL_CONFIG_H 785 if (!patime) 786 TIMESPEC_TO_TIMEVAL(&tv[0], &sb.st_atimespec); 787 if (!pmtime) 788 TIMESPEC_TO_TIMEVAL(&tv[1], &sb.st_mtimespec); 789#else 790 if (!patime) 791 tv[0].tv_sec = sb.st_atime; 792 if (!pmtime) 793 tv[1].tv_sec = sb.st_mtime; 794#endif 795 } else 796 syswarn(0, errno, "Cannot obtain file stats %s", fnm); 797 } 798 799 /* 800 * set the times 801 */ 802#if HAVE_LUTIMES 803 if (lutimes(fnm, tv)) 804#else 805 if (utimes(fnm, tv)) 806#endif 807 syswarn(1, errno, "Access/modification time set failed on: %s", 808 fnm); 809 return; 810} 811 812/* 813 * set_ids() 814 * set the uid and gid of a file system node 815 * Return: 816 * 0 when set, -1 on failure 817 */ 818 819int 820set_ids(char *fnm, uid_t uid, gid_t gid) 821{ 822 if (geteuid() == 0) 823 if (lchown(fnm, uid, gid)) { 824 (void)fflush(listf); 825 syswarn(1, errno, "Cannot set file uid/gid of %s", 826 fnm); 827 return(-1); 828 } 829 return(0); 830} 831 832/* 833 * set_pmode() 834 * Set file access mode 835 */ 836 837void 838set_pmode(char *fnm, mode_t mode) 839{ 840 mode &= A_BITS; 841 if (lchmod(fnm, mode)) { 842 (void)fflush(listf); 843 syswarn(1, errno, "Cannot set permissions on %s", fnm); 844 } 845 return; 846} 847 848/* 849 * set_chflags() 850 * Set 4.4BSD file flags 851 */ 852void 853set_chflags(char *fnm, u_int32_t flags) 854{ 855 856#if 0 857 if (chflags(fnm, flags) < 0 && errno != EOPNOTSUPP) 858 syswarn(1, errno, "Cannot set file flags on %s", fnm); 859#endif 860 return; 861} 862 863/* 864 * file_write() 865 * Write/copy a file (during copy or archive extract). This routine knows 866 * how to copy files with lseek holes in it. (Which are read as file 867 * blocks containing all 0's but do not have any file blocks associated 868 * with the data). Typical examples of these are files created by dbm 869 * variants (.pag files). While the file size of these files are huge, the 870 * actual storage is quite small (the files are sparse). The problem is 871 * the holes read as all zeros so are probably stored on the archive that 872 * way (there is no way to determine if the file block is really a hole, 873 * we only know that a file block of all zero's can be a hole). 874 * At this writing, no major archive format knows how to archive files 875 * with holes. However, on extraction (or during copy, -rw) we have to 876 * deal with these files. Without detecting the holes, the files can 877 * consume a lot of file space if just written to disk. This replacement 878 * for write when passed the basic allocation size of a file system block, 879 * uses lseek whenever it detects the input data is all 0 within that 880 * file block. In more detail, the strategy is as follows: 881 * While the input is all zero keep doing an lseek. Keep track of when we 882 * pass over file block boundaries. Only write when we hit a non zero 883 * input. once we have written a file block, we continue to write it to 884 * the end (we stop looking at the input). When we reach the start of the 885 * next file block, start checking for zero blocks again. Working on file 886 * block boundaries significantly reduces the overhead when copying files 887 * that are NOT very sparse. This overhead (when compared to a write) is 888 * almost below the measurement resolution on many systems. Without it, 889 * files with holes cannot be safely copied. It does has a side effect as 890 * it can put holes into files that did not have them before, but that is 891 * not a problem since the file contents are unchanged (in fact it saves 892 * file space). (Except on paging files for diskless clients. But since we 893 * cannot determine one of those file from here, we ignore them). If this 894 * ever ends up on a system where CTG files are supported and the holes 895 * are not desired, just do a conditional test in those routines that 896 * call file_write() and have it call write() instead. BEFORE CLOSING THE 897 * FILE, make sure to call file_flush() when the last write finishes with 898 * an empty block. A lot of file systems will not create an lseek hole at 899 * the end. In this case we drop a single 0 at the end to force the 900 * trailing 0's in the file. 901 * ---Parameters--- 902 * rem: how many bytes left in this file system block 903 * isempt: have we written to the file block yet (is it empty) 904 * sz: basic file block allocation size 905 * cnt: number of bytes on this write 906 * str: buffer to write 907 * Return: 908 * number of bytes written, -1 on write (or lseek) error. 909 */ 910 911int 912file_write(int fd, char *str, int cnt, int *rem, int *isempt, int sz, 913 char *name) 914{ 915 char *pt; 916 char *end; 917 int wcnt; 918 char *st = str; 919 char **strp; 920 921 /* 922 * while we have data to process 923 */ 924 while (cnt) { 925 if (!*rem) { 926 /* 927 * We are now at the start of file system block again 928 * (or what we think one is...). start looking for 929 * empty blocks again 930 */ 931 *isempt = 1; 932 *rem = sz; 933 } 934 935 /* 936 * only examine up to the end of the current file block or 937 * remaining characters to write, whatever is smaller 938 */ 939 wcnt = MIN(cnt, *rem); 940 cnt -= wcnt; 941 *rem -= wcnt; 942 if (*isempt) { 943 /* 944 * have not written to this block yet, so we keep 945 * looking for zero's 946 */ 947 pt = st; 948 end = st + wcnt; 949 950 /* 951 * look for a zero filled buffer 952 */ 953 while ((pt < end) && (*pt == '\0')) 954 ++pt; 955 956 if (pt == end) { 957 /* 958 * skip, buf is empty so far 959 */ 960 if (fd > -1 && 961 lseek(fd, (off_t)wcnt, SEEK_CUR) < 0) { 962 syswarn(1, errno, "File seek on %s", 963 name); 964 return(-1); 965 } 966 st = pt; 967 continue; 968 } 969 /* 970 * drat, the buf is not zero filled 971 */ 972 *isempt = 0; 973 } 974 975 /* 976 * have non-zero data in this file system block, have to write 977 */ 978 switch (fd) { 979 case -1: 980 strp = &gnu_name_string; 981 break; 982 case -2: 983 strp = &gnu_link_string; 984 break; 985 default: 986 strp = NULL; 987 break; 988 } 989 if (strp) { 990 if (*strp) 991 err(1, "WARNING! Major Internal Error! GNU hack Failing!"); 992 *strp = malloc(wcnt + 1); 993 if (*strp == NULL) { 994 tty_warn(1, "Out of memory"); 995 return(-1); 996 } 997 strlcpy(*strp, st, wcnt); 998 break; 999 } else if (xwrite(fd, st, wcnt) != wcnt) { 1000 syswarn(1, errno, "Failed write to file %s", name); 1001 return(-1); 1002 } 1003 st += wcnt; 1004 } 1005 return(st - str); 1006} 1007 1008/* 1009 * file_flush() 1010 * when the last file block in a file is zero, many file systems will not 1011 * let us create a hole at the end. To get the last block with zeros, we 1012 * write the last BYTE with a zero (back up one byte and write a zero). 1013 */ 1014 1015void 1016file_flush(int fd, char *fname, int isempt) 1017{ 1018 static char blnk[] = "\0"; 1019 1020 /* 1021 * silly test, but make sure we are only called when the last block is 1022 * filled with all zeros. 1023 */ 1024 if (!isempt) 1025 return; 1026 1027 /* 1028 * move back one byte and write a zero 1029 */ 1030 if (lseek(fd, (off_t)-1, SEEK_CUR) < 0) { 1031 syswarn(1, errno, "Failed seek on file %s", fname); 1032 return; 1033 } 1034 1035 if (write_with_restart(fd, blnk, 1) < 0) 1036 syswarn(1, errno, "Failed write to file %s", fname); 1037 return; 1038} 1039 1040/* 1041 * rdfile_close() 1042 * close a file we have been reading (to copy or archive). If we have to 1043 * reset access time (tflag) do so (the times are stored in arcn). 1044 */ 1045 1046void 1047rdfile_close(ARCHD *arcn, int *fd) 1048{ 1049 /* 1050 * make sure the file is open 1051 */ 1052 if (*fd < 0) 1053 return; 1054 1055 (void)close(*fd); 1056 *fd = -1; 1057 if (!tflag) 1058 return; 1059 1060 /* 1061 * user wants last access time reset 1062 */ 1063 set_ftime(arcn->org_name, arcn->sb.st_mtime, arcn->sb.st_atime, 1); 1064 return; 1065} 1066 1067/* 1068 * set_crc() 1069 * read a file to calculate its crc. This is a real drag. Archive formats 1070 * that have this, end up reading the file twice (we have to write the 1071 * header WITH the crc before writing the file contents. Oh well... 1072 * Return: 1073 * 0 if was able to calculate the crc, -1 otherwise 1074 */ 1075 1076int 1077set_crc(ARCHD *arcn, int fd) 1078{ 1079 int i; 1080 int res; 1081 off_t cpcnt = 0L; 1082 u_long size; 1083 unsigned long crc = 0L; 1084 char tbuf[FILEBLK]; 1085 struct stat sb; 1086 1087 if (fd < 0) { 1088 /* 1089 * hmm, no fd, should never happen. well no crc then. 1090 */ 1091 arcn->crc = 0L; 1092 return(0); 1093 } 1094 1095 if ((size = (u_long)arcn->sb.st_blksize) > (u_long)sizeof(tbuf)) 1096 size = (u_long)sizeof(tbuf); 1097 1098 /* 1099 * read all the bytes we think that there are in the file. If the user 1100 * is trying to archive an active file, forget this file. 1101 */ 1102 for(;;) { 1103 if ((res = read(fd, tbuf, size)) <= 0) 1104 break; 1105 cpcnt += res; 1106 for (i = 0; i < res; ++i) 1107 crc += (tbuf[i] & 0xff); 1108 } 1109 1110 /* 1111 * safety check. we want to avoid archiving files that are active as 1112 * they can create inconsistant archive copies. 1113 */ 1114 if (cpcnt != arcn->sb.st_size) 1115 tty_warn(1, "File changed size %s", arcn->org_name); 1116 else if (fstat(fd, &sb) < 0) 1117 syswarn(1, errno, "Failed stat on %s", arcn->org_name); 1118 else if (arcn->sb.st_mtime != sb.st_mtime) 1119 tty_warn(1, "File %s was modified during read", arcn->org_name); 1120 else if (lseek(fd, (off_t)0L, SEEK_SET) < 0) 1121 syswarn(1, errno, "File rewind failed on: %s", arcn->org_name); 1122 else { 1123 arcn->crc = crc; 1124 return(0); 1125 } 1126 return(-1); 1127} 1128