file_subs.c revision 1.65
1/* $NetBSD: file_subs.c,v 1.65 2023/05/28 21:42:40 lukem 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 1.65 2023/05/28 21:42:40 lukem 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_cleanup() 183 * Close file descriptor to a file just created by pax. 184 * Unlinks any temporary file. 185 */ 186 187void 188file_cleanup(ARCHD *arcn, int fd) 189{ 190 char *tmp_name; 191 192 if (fd < 0) 193 return; 194 195 tmp_name = (arcn->tmp_name != NULL) ? arcn->tmp_name : arcn->name; 196 197 if (close(fd) < 0) 198 syswarn(0, errno, "Cannot close file descriptor on %s", 199 tmp_name); 200 201 /* No temporary file to cleanup? */ 202 if (arcn->tmp_name == NULL) 203 return; 204 205 /* Cleanup the temporary file. */ 206 if (unlink(arcn->tmp_name) < 0) { 207 syswarn(0, errno, "Cannot unlink %s", arcn->tmp_name); 208 } 209 210 free(arcn->tmp_name); 211 arcn->tmp_name = NULL; 212 xtmp_name = NULL; 213} 214 215/* 216 * file_close() 217 * Close file descriptor to a file just created by pax. Sets modes, 218 * ownership and times as required. 219 */ 220 221void 222file_close(ARCHD *arcn, int fd) 223{ 224 char *tmp_name; 225 int res; 226 227 if (fd < 0) 228 return; 229 230 tmp_name = (arcn->tmp_name != NULL) ? arcn->tmp_name : arcn->name; 231 232 if (close(fd) < 0) 233 syswarn(0, errno, "Cannot close file descriptor on %s", 234 tmp_name); 235 236 /* 237 * set owner/groups first as this may strip off mode bits we want 238 * then set file permission modes. Then set file access and 239 * modification times. 240 */ 241 if (pids) 242 res = set_ids(tmp_name, arcn->sb.st_uid, arcn->sb.st_gid); 243 else 244 res = 0; 245 246 /* 247 * IMPORTANT SECURITY NOTE: 248 * if not preserving mode or we cannot set uid/gid, then PROHIBIT 249 * set uid/gid bits but restore the file modes (since mkstemp doesn't). 250 */ 251 if (!pmode || res) 252 arcn->sb.st_mode &= ~SETBITS(0); 253 if (pmode) 254 set_pmode(tmp_name, arcn->sb.st_mode); 255 else 256 set_pmode(tmp_name, 257 apply_umask((arcn->sb.st_mode & FILEBITS(0)))); 258 if (patime || pmtime) 259 set_ftime(tmp_name, arcn->sb.st_mtime, 260 arcn->sb.st_atime, 0, 0); 261 262 /* Did we write directly to the target file? */ 263 if (arcn->tmp_name == NULL) 264 return; 265 266 /* 267 * Finally, now the temp file is fully instantiated rename it to 268 * the desired file name. 269 */ 270 if (rename(tmp_name, arcn->name) < 0) { 271 syswarn(0, errno, "Cannot rename %s to %s", 272 tmp_name, arcn->name); 273 (void)unlink(tmp_name); 274 } 275 276#if HAVE_STRUCT_STAT_ST_FLAGS 277 if (pfflags && arcn->type != PAX_SLK) 278 set_chflags(arcn->name, arcn->sb.st_flags); 279#endif 280 281 free(arcn->tmp_name); 282 arcn->tmp_name = NULL; 283 xtmp_name = NULL; 284} 285 286/* 287 * lnk_creat() 288 * Create a hard link to arcn->ln_name from arcn->name. arcn->ln_name 289 * must exist; 290 * Return: 291 * 0 if ok, -1 otherwise 292 */ 293 294int 295lnk_creat(ARCHD *arcn, int *payload) 296{ 297 struct stat sb; 298 299 /* 300 * Check if this hardlink carries the "payload". In "cpio" archives 301 * it's usually the last record of a set of hardlinks which includes 302 * the contents of the file. 303 * 304 */ 305 *payload = S_ISREG(arcn->sb.st_mode) && 306 (arcn->sb.st_size > 0) && (arcn->sb.st_size <= arcn->skip); 307 308 /* 309 * We may be running as root, so we have to be sure that link target 310 * is not a directory, so we lstat and check. XXX: This is still racy. 311 */ 312 if (lstat(arcn->ln_name, &sb) != -1 && S_ISDIR(sb.st_mode)) { 313 tty_warn(1, "A hard link to the directory %s is not allowed", 314 arcn->ln_name); 315 return -1; 316 } 317 318 return mk_link(arcn->ln_name, &sb, arcn->name, 0); 319} 320 321/* 322 * cross_lnk() 323 * Create a hard link to arcn->org_name from arcn->name. Only used in copy 324 * with the -l flag. No warning or error if this does not succeed (we will 325 * then just create the file) 326 * Return: 327 * 1 if copy() should try to create this file node 328 * 0 if cross_lnk() ok, -1 for fatal flaw (like linking to self). 329 */ 330 331int 332cross_lnk(ARCHD *arcn) 333{ 334 /* 335 * try to make a link to original file (-l flag in copy mode). make 336 * sure we do not try to link to directories in case we are running as 337 * root (and it might succeed). 338 */ 339 if (arcn->type == PAX_DIR) 340 return 1; 341 return mk_link(arcn->org_name, &(arcn->sb), arcn->name, 1); 342} 343 344/* 345 * chk_same() 346 * In copy mode if we are not trying to make hard links between the src 347 * and destinations, make sure we are not going to overwrite ourselves by 348 * accident. This slows things down a little, but we have to protect all 349 * those people who make typing errors. 350 * Return: 351 * 1 the target does not exist, go ahead and copy 352 * 0 skip it file exists (-k) or may be the same as source file 353 */ 354 355int 356chk_same(ARCHD *arcn) 357{ 358 struct stat sb; 359 360 /* 361 * if file does not exist, return. if file exists and -k, skip it 362 * quietly 363 */ 364 if (lstat(arcn->name, &sb) < 0) 365 return 1; 366 if (kflag) 367 return 0; 368 369 /* 370 * better make sure the user does not have src == dest by mistake 371 */ 372 if ((arcn->sb.st_dev == sb.st_dev) && (arcn->sb.st_ino == sb.st_ino)) { 373 tty_warn(1, "Unable to copy %s, file would overwrite itself", 374 arcn->name); 375 return 0; 376 } 377 return 1; 378} 379 380/* 381 * mk_link() 382 * try to make a hard link between two files. if ign set, we do not 383 * complain. 384 * Return: 385 * 0 if successful (or we are done with this file but no error, such as 386 * finding the from file exists and the user has set -k). 387 * 1 when ign was set to indicates we could not make the link but we 388 * should try to copy/extract the file as that might work (and is an 389 * allowed option). -1 an error occurred. 390 */ 391 392static int 393mk_link(char *to, struct stat *to_sb, char *from, int ign) 394{ 395 struct stat sb; 396 int oerrno; 397 398 /* 399 * if from file exists, it has to be unlinked to make the link. If the 400 * file exists and -k is set, skip it quietly 401 */ 402 if (lstat(from, &sb) == 0) { 403 if (kflag) 404 return 0; 405 406 /* 407 * make sure it is not the same file, protect the user 408 */ 409 if ((to_sb->st_dev==sb.st_dev)&&(to_sb->st_ino == sb.st_ino)) { 410 tty_warn(1, "Cannot link file %s to itself", to); 411 return -1; 412 } 413 414 /* 415 * try to get rid of the file, based on the type 416 */ 417 if (S_ISDIR(sb.st_mode) && strcmp(from, ".") != 0) { 418 if (rmdir(from) < 0) { 419 syswarn(1, errno, "Cannot remove %s", from); 420 return -1; 421 } 422 } else if (unlink(from) < 0) { 423 if (!ign) { 424 syswarn(1, errno, "Cannot remove %s", from); 425 return -1; 426 } 427 return 1; 428 } 429 } 430 431 /* 432 * from file is gone (or did not exist), try to make the hard link. 433 * if it fails, check the path and try it again (if chk_path() says to 434 * try again) 435 */ 436 for (;;) { 437 if (link(to, from) == 0) 438 break; 439 oerrno = errno; 440 if (chk_path(from, to_sb->st_uid, to_sb->st_gid) == 0) 441 continue; 442 if (!ign) { 443 syswarn(1, oerrno, "Cannot link to %s from %s", to, 444 from); 445 return -1; 446 } 447 return 1; 448 } 449 450 /* 451 * all right the link was made 452 */ 453 return 0; 454} 455 456/* 457 * node_creat() 458 * create an entry in the file system (other than a file or hard link). 459 * If successful, sets uid/gid modes and times as required. 460 * Return: 461 * 0 if ok, -1 otherwise 462 */ 463 464int 465node_creat(ARCHD *arcn) 466{ 467 int res; 468 int ign = 0; 469 int oerrno; 470 int pass = 0; 471 mode_t file_mode; 472 struct stat sb; 473 char target[MAXPATHLEN]; 474 char *nm = arcn->name; 475 int len; 476 477 /* 478 * create node based on type, if that fails try to unlink the node and 479 * try again. finally check the path and try again. As noted in the 480 * file and link creation routines, this method seems to exhibit the 481 * best performance in general use workloads. 482 */ 483 file_mode = arcn->sb.st_mode & FILEBITS(arcn->type == PAX_DIR); 484 485 for (;;) { 486 switch (arcn->type) { 487 case PAX_DIR: 488 /* 489 * If -h (or -L) was given in tar-mode, follow the 490 * potential symlink chain before trying to create the 491 * directory. 492 */ 493 if (strcmp(NM_TAR, argv0) == 0 && Lflag) { 494 while (lstat(nm, &sb) == 0 && 495 S_ISLNK(sb.st_mode)) { 496 len = readlink(nm, target, 497 sizeof target - 1); 498 if (len == -1) { 499 syswarn(0, errno, 500 "cannot follow symlink %s " 501 "in chain for %s", 502 nm, arcn->name); 503 res = -1; 504 goto badlink; 505 } 506 target[len] = '\0'; 507 nm = target; 508 } 509 } 510 res = domkdir(nm, file_mode); 511badlink: 512 if (ign) 513 res = 0; 514 break; 515 case PAX_CHR: 516 file_mode |= S_IFCHR; 517 res = mknod(nm, file_mode, arcn->sb.st_rdev); 518 break; 519 case PAX_BLK: 520 file_mode |= S_IFBLK; 521 res = mknod(nm, file_mode, arcn->sb.st_rdev); 522 break; 523 case PAX_FIF: 524 res = mkfifo(nm, file_mode); 525 break; 526 case PAX_SCK: 527 /* 528 * Skip sockets, operation has no meaning under BSD 529 */ 530 tty_warn(0, 531 "%s skipped. Sockets cannot be copied or extracted", 532 nm); 533 return (-1); 534 case PAX_SLK: 535 res = symlink(arcn->ln_name, nm); 536 break; 537 case PAX_CTG: 538 case PAX_HLK: 539 case PAX_HRG: 540 case PAX_REG: 541 default: 542 /* 543 * we should never get here 544 */ 545 tty_warn(0, "%s has an unknown file type, skipping", 546 nm); 547 return (-1); 548 } 549 550 /* 551 * if we were able to create the node break out of the loop, 552 * otherwise try to unlink the node and try again. if that 553 * fails check the full path and try a final time. 554 */ 555 if (res == 0) 556 break; 557 558 /* 559 * we failed to make the node 560 */ 561 oerrno = errno; 562 switch (pass++) { 563 case 0: 564 if ((ign = unlnk_exist(nm, arcn->type)) < 0) 565 return (-1); 566 continue; 567 568 case 1: 569 if (nodirs || 570 chk_path(nm, arcn->sb.st_uid, 571 arcn->sb.st_gid) < 0) { 572 syswarn(1, oerrno, "Cannot create %s", nm); 573 return (-1); 574 } 575 continue; 576 } 577 578 /* 579 * it must be a file that exists but we can't create or 580 * remove, but we must avoid the infinite loop. 581 */ 582 break; 583 } 584 585 /* 586 * we were able to create the node. set uid/gid, modes and times 587 */ 588 if (pids) 589 res = set_ids(nm, arcn->sb.st_uid, arcn->sb.st_gid); 590 else 591 res = 0; 592 593 /* 594 * IMPORTANT SECURITY NOTE: 595 * if not preserving mode or we cannot set uid/gid, then PROHIBIT any 596 * set uid/gid bits 597 */ 598 if (!pmode || res) 599 arcn->sb.st_mode &= ~SETBITS(arcn->type == PAX_DIR); 600 if (pmode) 601 set_pmode(arcn->name, arcn->sb.st_mode); 602 603 if (arcn->type == PAX_DIR && strcmp(NM_CPIO, argv0) != 0) { 604 /* 605 * Dirs must be processed again at end of extract to set times 606 * and modes to agree with those stored in the archive. However 607 * to allow extract to continue, we may have to also set owner 608 * rights. This allows nodes in the archive that are children 609 * of this directory to be extracted without failure. Both time 610 * and modes will be fixed after the entire archive is read and 611 * before pax exits. 612 */ 613 if (access(nm, R_OK | W_OK | X_OK) < 0) { 614 if (lstat(nm, &sb) < 0) { 615 syswarn(0, errno,"Cannot access %s (stat)", 616 arcn->name); 617 set_pmode(nm,file_mode | S_IRWXU); 618 } else { 619 /* 620 * We have to add rights to the dir, so we make 621 * sure to restore the mode. The mode must be 622 * restored AS CREATED and not as stored if 623 * pmode is not set. 624 */ 625 set_pmode(nm, ((sb.st_mode & 626 FILEBITS(arcn->type == PAX_DIR)) | 627 S_IRWXU)); 628 if (!pmode) 629 arcn->sb.st_mode = sb.st_mode; 630 } 631 632 /* 633 * we have to force the mode to what was set here, 634 * since we changed it from the default as created. 635 */ 636 add_dir(nm, arcn->nlen, &(arcn->sb), 1); 637 } else if (pmode || patime || pmtime) 638 add_dir(nm, arcn->nlen, &(arcn->sb), 0); 639 } 640 641 if (patime || pmtime) 642 set_ftime(arcn->name, arcn->sb.st_mtime, 643 arcn->sb.st_atime, 0, (arcn->type == PAX_SLK) ? 1 : 0); 644 645#if HAVE_STRUCT_STAT_ST_FLAGS 646 if (pfflags && arcn->type != PAX_SLK) 647 set_chflags(arcn->name, arcn->sb.st_flags); 648#endif 649 return 0; 650} 651 652/* 653 * unlnk_exist() 654 * Remove node from file system with the specified name. We pass the type 655 * of the node that is going to replace it. When we try to create a 656 * directory and find that it already exists, we allow processing to 657 * continue as proper modes etc will always be set for it later on. 658 * Return: 659 * 0 is ok to proceed, no file with the specified name exists 660 * -1 we were unable to remove the node, or we should not remove it (-k) 661 * 1 we found a directory and we were going to create a directory. 662 */ 663 664int 665unlnk_exist(char *name, int type) 666{ 667 struct stat sb; 668 669 /* 670 * the file does not exist, or -k we are done 671 */ 672 if (lstat(name, &sb) < 0) 673 return 0; 674 if (kflag) 675 return -1; 676 677 if (S_ISDIR(sb.st_mode)) { 678 /* 679 * try to remove a directory, if it fails and we were going to 680 * create a directory anyway, tell the caller (return a 1). 681 * 682 * don't try to remove the directory if the name is "." 683 * otherwise later file/directory creation fails. 684 */ 685 if (strcmp(name, ".") == 0) 686 return 1; 687 if (rmdir(name) < 0) { 688 if (type == PAX_DIR) 689 return 1; 690 syswarn(1, errno, "Cannot remove directory %s", name); 691 return -1; 692 } 693 return 0; 694 } 695 696 /* 697 * try to get rid of all non-directory type nodes 698 */ 699 if (unlink(name) < 0) { 700 (void)fflush(listf); 701 syswarn(1, errno, "Cannot unlink %s", name); 702 return -1; 703 } 704 return 0; 705} 706 707/* 708 * chk_path() 709 * We were trying to create some kind of node in the file system and it 710 * failed. chk_path() makes sure the path up to the node exists and is 711 * writable. When we have to create a directory that is missing along the 712 * path somewhere, the directory we create will be set to the same 713 * uid/gid as the file has (when uid and gid are being preserved). 714 * NOTE: this routine is a real performance loss. It is only used as a 715 * last resort when trying to create entries in the file system. 716 * Return: 717 * -1 when it could find nothing it is allowed to fix. 718 * 0 otherwise 719 */ 720 721int 722chk_path(char *name, uid_t st_uid, gid_t st_gid) 723{ 724 char *spt = name; 725 struct stat sb; 726 int retval = -1; 727 728 /* 729 * watch out for paths with nodes stored directly in / (e.g. /bozo) 730 */ 731 if (*spt == '/') 732 ++spt; 733 734 for(;;) { 735 /* 736 * work forward from the first / and check each part of 737 * the path 738 */ 739 spt = strchr(spt, '/'); 740 if (spt == NULL) 741 break; 742 *spt = '\0'; 743 744 /* 745 * if it exists we assume it is a directory, it is not within 746 * the spec (at least it seems to read that way) to alter the 747 * file system for nodes NOT EXPLICITLY stored on the archive. 748 * If that assumption is changed, you would test the node here 749 * and figure out how to get rid of it (probably like some 750 * recursive unlink()) or fix up the directory permissions if 751 * required (do an access()). 752 */ 753 if (lstat(name, &sb) == 0) { 754 *(spt++) = '/'; 755 continue; 756 } 757 758 /* 759 * the path fails at this point, see if we can create the 760 * needed directory and continue on 761 */ 762 if (domkdir(name, S_IRWXU | S_IRWXG | S_IRWXO) == -1) { 763 *spt = '/'; 764 retval = -1; 765 break; 766 } 767 768 /* 769 * we were able to create the directory. We will tell the 770 * caller that we found something to fix, and it is ok to try 771 * and create the node again. 772 */ 773 retval = 0; 774 if (pids) 775 (void)set_ids(name, st_uid, st_gid); 776 777 /* 778 * make sure the user doesn't have some strange umask that 779 * causes this newly created directory to be unusable. We fix 780 * the modes and restore them back to the creation default at 781 * the end of pax 782 */ 783 if ((access(name, R_OK | W_OK | X_OK) < 0) && 784 (lstat(name, &sb) == 0)) { 785 set_pmode(name, ((sb.st_mode & FILEBITS(0)) | 786 S_IRWXU)); 787 add_dir(name, spt - name, &sb, 1); 788 } 789 *(spt++) = '/'; 790 continue; 791 } 792 /* 793 * We perform one final check here, because if someone else 794 * created the directory in parallel with us, we might return 795 * the wrong error code, even if the directory exists now. 796 */ 797 if (retval == -1 && stat(name, &sb) == 0 && S_ISDIR(sb.st_mode)) 798 retval = 0; 799 return retval; 800} 801 802/* 803 * set_ftime() 804 * Set the access time and modification time for a named file. If frc 805 * is non-zero we force these times to be set even if the user did not 806 * request access and/or modification time preservation (this is also 807 * used by -t to reset access times). 808 * When ign is zero, only those times the user has asked for are set, the 809 * other ones are left alone. We do not assume the un-documented feature 810 * of many utimes() implementations that consider a 0 time value as a do 811 * not set request. 812 * 813 * Unfortunately, there are systems where lutimes() is present but does 814 * not work on some filesystem types, which cannot be detected at 815 * compile time. This requires passing down symlink knowledge into 816 * this function to obtain correct operation. Linux with XFS is one 817 * example of such a system. 818 */ 819 820void 821set_ftime(char *fnm, time_t mtime, time_t atime, int frc, int slk) 822{ 823 struct timeval tv[2]; 824 struct stat sb; 825 826 tv[0].tv_sec = atime; 827 tv[0].tv_usec = 0; 828 tv[1].tv_sec = mtime; 829 tv[1].tv_usec = 0; 830 if (!frc && (!patime || !pmtime)) { 831 /* 832 * if we are not forcing, only set those times the user wants 833 * set. We get the current values of the times if we need them. 834 */ 835 if (lstat(fnm, &sb) == 0) { 836#if BSD4_4 && !HAVE_NBTOOL_CONFIG_H 837 if (!patime) 838 TIMESPEC_TO_TIMEVAL(&tv[0], &sb.st_atimespec); 839 if (!pmtime) 840 TIMESPEC_TO_TIMEVAL(&tv[1], &sb.st_mtimespec); 841#else 842 if (!patime) 843 tv[0].tv_sec = sb.st_atime; 844 if (!pmtime) 845 tv[1].tv_sec = sb.st_mtime; 846#endif 847 } else 848 syswarn(0, errno, "Cannot obtain file stats %s", fnm); 849 } 850 851 /* 852 * set the times 853 */ 854#if HAVE_LUTIMES 855 if (lutimes(fnm, tv) == 0) 856 return; 857 if (errno != ENOSYS) /* XXX linux: lutimes is per-FS */ 858 goto bad; 859#endif 860 if (slk) 861 return; 862 if (utimes(fnm, tv) == -1) 863 goto bad; 864 return; 865bad: 866 syswarn(1, errno, "Access/modification time set failed on: %s", fnm); 867} 868 869/* 870 * set_ids() 871 * set the uid and gid of a file system node 872 * Return: 873 * 0 when set, -1 on failure 874 */ 875 876int 877set_ids(char *fnm, uid_t uid, gid_t gid) 878{ 879 if (geteuid() == 0) 880 if (lchown(fnm, uid, gid)) { 881 (void)fflush(listf); 882 syswarn(1, errno, "Cannot set file uid/gid of %s", 883 fnm); 884 return -1; 885 } 886 return 0; 887} 888 889/* 890 * set_pmode() 891 * Set file access mode 892 */ 893 894void 895set_pmode(char *fnm, mode_t mode) 896{ 897 mode &= A_BITS; 898 if (lchmod(fnm, mode)) { 899 (void)fflush(listf); 900 syswarn(1, errno, "Cannot set permissions on %s", fnm); 901 } 902 return; 903} 904 905/* 906 * set_chflags() 907 * Set 4.4BSD file flags 908 */ 909void 910set_chflags(char *fnm, u_int32_t flags) 911{ 912 913#if 0 914 if (chflags(fnm, flags) < 0 && errno != EOPNOTSUPP) 915 syswarn(1, errno, "Cannot set file flags on %s", fnm); 916#endif 917 return; 918} 919 920/* 921 * file_write() 922 * Write/copy a file (during copy or archive extract). This routine knows 923 * how to copy files with lseek holes in it. (Which are read as file 924 * blocks containing all 0's but do not have any file blocks associated 925 * with the data). Typical examples of these are files created by dbm 926 * variants (.pag files). While the file size of these files are huge, the 927 * actual storage is quite small (the files are sparse). The problem is 928 * the holes read as all zeros so are probably stored on the archive that 929 * way (there is no way to determine if the file block is really a hole, 930 * we only know that a file block of all zeros can be a hole). 931 * At this writing, no major archive format knows how to archive files 932 * with holes. However, on extraction (or during copy, -rw) we have to 933 * deal with these files. Without detecting the holes, the files can 934 * consume a lot of file space if just written to disk. This replacement 935 * for write when passed the basic allocation size of a file system block, 936 * uses lseek whenever it detects the input data is all 0 within that 937 * file block. In more detail, the strategy is as follows: 938 * While the input is all zero keep doing an lseek. Keep track of when we 939 * pass over file block boundaries. Only write when we hit a non zero 940 * input. once we have written a file block, we continue to write it to 941 * the end (we stop looking at the input). When we reach the start of the 942 * next file block, start checking for zero blocks again. Working on file 943 * block boundaries significantly reduces the overhead when copying files 944 * that are NOT very sparse. This overhead (when compared to a write) is 945 * almost below the measurement resolution on many systems. Without it, 946 * files with holes cannot be safely copied. It does has a side effect as 947 * it can put holes into files that did not have them before, but that is 948 * not a problem since the file contents are unchanged (in fact it saves 949 * file space). (Except on paging files for diskless clients. But since we 950 * cannot determine one of those file from here, we ignore them). If this 951 * ever ends up on a system where CTG files are supported and the holes 952 * are not desired, just do a conditional test in those routines that 953 * call file_write() and have it call write() instead. BEFORE CLOSING THE 954 * FILE, make sure to call file_flush() when the last write finishes with 955 * an empty block. A lot of file systems will not create an lseek hole at 956 * the end. In this case we drop a single 0 at the end to force the 957 * trailing 0's in the file. 958 * ---Parameters--- 959 * rem: how many bytes left in this file system block 960 * isempt: have we written to the file block yet (is it empty) 961 * sz: basic file block allocation size 962 * cnt: number of bytes on this write 963 * str: buffer to write 964 * Return: 965 * number of bytes written, -1 on write (or lseek) error. 966 */ 967 968int 969file_write(int fd, char *str, int cnt, int *rem, int *isempt, int sz, 970 char *name) 971{ 972 char *pt; 973 char *end; 974 int wcnt; 975 char *st = str; 976 char **strp; 977 size_t *lenp; 978 979 /* 980 * while we have data to process 981 */ 982 while (cnt) { 983 if (!*rem) { 984 /* 985 * We are now at the start of file system block again 986 * (or what we think one is...). start looking for 987 * empty blocks again 988 */ 989 *isempt = 1; 990 *rem = sz; 991 } 992 993 /* 994 * only examine up to the end of the current file block or 995 * remaining characters to write, whatever is smaller 996 */ 997 wcnt = MIN(cnt, *rem); 998 cnt -= wcnt; 999 *rem -= wcnt; 1000 if (*isempt) { 1001 /* 1002 * have not written to this block yet, so we keep 1003 * looking for zeros 1004 */ 1005 pt = st; 1006 end = st + wcnt; 1007 1008 /* 1009 * look for a zero filled buffer 1010 */ 1011 while ((pt < end) && (*pt == '\0')) 1012 ++pt; 1013 1014 if (pt == end) { 1015 /* 1016 * skip, buf is empty so far 1017 */ 1018 if (fd > -1 && 1019 lseek(fd, (off_t)wcnt, SEEK_CUR) < 0) { 1020 syswarn(1, errno, "File seek on %s", 1021 name); 1022 return -1; 1023 } 1024 st = pt; 1025 continue; 1026 } 1027 /* 1028 * drat, the buf is not zero filled 1029 */ 1030 *isempt = 0; 1031 } 1032 1033 /* 1034 * have non-zero data in this file system block, have to write 1035 */ 1036 switch (fd) { 1037 case -PAX_GLF: 1038 strp = &gnu_name_string; 1039 lenp = &gnu_name_length; 1040 break; 1041 case -PAX_GLL: 1042 strp = &gnu_link_string; 1043 lenp = &gnu_link_length; 1044 break; 1045 default: 1046 strp = NULL; 1047 lenp = NULL; 1048 break; 1049 } 1050 if (strp) { 1051 char *nstr = *strp ? realloc(*strp, *lenp + wcnt + 1) : 1052 malloc(wcnt + 1); 1053 if (nstr == NULL) { 1054 tty_warn(1, "Out of memory"); 1055 return -1; 1056 } 1057 (void)strlcpy(&nstr[*lenp], st, wcnt + 1); 1058 *strp = nstr; 1059 *lenp += wcnt; 1060 } else if (xwrite(fd, st, wcnt) != wcnt) { 1061 syswarn(1, errno, "Failed write to file %s", name); 1062 return -1; 1063 } 1064 st += wcnt; 1065 } 1066 return st - str; 1067} 1068 1069/* 1070 * file_flush() 1071 * when the last file block in a file is zero, many file systems will not 1072 * let us create a hole at the end. To get the last block with zeros, we 1073 * write the last BYTE with a zero (back up one byte and write a zero). 1074 * Return: 1075 * 0 if was able to flush the file, -1 otherwise 1076 */ 1077 1078int 1079file_flush(int fd, char *fname, int isempt) 1080{ 1081 static char blnk[] = "\0"; 1082 1083 /* 1084 * silly test, but make sure we are only called when the last block is 1085 * filled with all zeros. 1086 */ 1087 if (!isempt) 1088 return 0; 1089 1090 /* 1091 * move back one byte and write a zero 1092 */ 1093 if (lseek(fd, (off_t)-1, SEEK_CUR) < 0) { 1094 syswarn(1, errno, "Failed seek on file %s", fname); 1095 return -1; 1096 } 1097 1098 if (write_with_restart(fd, blnk, 1) < 0) { 1099 syswarn(1, errno, "Failed write to file %s", fname); 1100 return -1; 1101 } 1102 return 0; 1103} 1104 1105/* 1106 * rdfile_close() 1107 * close a file we have been reading (to copy or archive). If we have to 1108 * reset access time (tflag) do so (the times are stored in arcn). 1109 */ 1110 1111void 1112rdfile_close(ARCHD *arcn, int *fd) 1113{ 1114 /* 1115 * make sure the file is open 1116 */ 1117 if (*fd < 0) 1118 return; 1119 1120 (void)close(*fd); 1121 *fd = -1; 1122 if (!tflag) 1123 return; 1124 1125 /* 1126 * user wants last access time reset 1127 */ 1128 set_ftime(arcn->org_name, arcn->sb.st_mtime, arcn->sb.st_atime, 1, 0); 1129 return; 1130} 1131 1132/* 1133 * set_crc() 1134 * read a file to calculate its crc. This is a real drag. Archive formats 1135 * that have this, end up reading the file twice (we have to write the 1136 * header WITH the crc before writing the file contents. Oh well... 1137 * Return: 1138 * 0 if was able to calculate the crc, -1 otherwise 1139 */ 1140 1141int 1142set_crc(ARCHD *arcn, int fd) 1143{ 1144 int i; 1145 int res; 1146 off_t cpcnt = 0L; 1147 u_long size; 1148 unsigned long crc = 0L; 1149 char tbuf[FILEBLK]; 1150 struct stat sb; 1151 1152 if (fd < 0) { 1153 /* 1154 * hmm, no fd, should never happen. well no crc then. 1155 */ 1156 arcn->crc = 0L; 1157 return 0; 1158 } 1159 1160 if ((size = (u_long)arcn->sb.st_blksize) > (u_long)sizeof(tbuf)) 1161 size = (u_long)sizeof(tbuf); 1162 1163 /* 1164 * read all the bytes we think that there are in the file. If the user 1165 * is trying to archive an active file, forget this file. 1166 */ 1167 for(;;) { 1168 if ((res = read(fd, tbuf, size)) <= 0) 1169 break; 1170 cpcnt += res; 1171 for (i = 0; i < res; ++i) 1172 crc += (tbuf[i] & 0xff); 1173 } 1174 1175 /* 1176 * safety check. we want to avoid archiving files that are active as 1177 * they can create inconsistent archive copies. 1178 */ 1179 if (cpcnt != arcn->sb.st_size) 1180 tty_warn(1, "File changed size %s", arcn->org_name); 1181 else if (fstat(fd, &sb) < 0) 1182 syswarn(1, errno, "Failed stat on %s", arcn->org_name); 1183 else if (arcn->sb.st_mtime != sb.st_mtime) 1184 tty_warn(1, "File %s was modified during read", arcn->org_name); 1185 else if (lseek(fd, (off_t)0L, SEEK_SET) < 0) 1186 syswarn(1, errno, "File rewind failed on: %s", arcn->org_name); 1187 else { 1188 arcn->crc = crc; 1189 return 0; 1190 } 1191 return -1; 1192} 1193