1/* $OpenBSD: file_subs.c,v 1.30 2005/11/09 19:59:06 otto Exp $ */ 2/* $NetBSD: file_subs.c,v 1.4 1995/03/21 09:07:18 cgd Exp $ */ 3 4/*- 5 * Copyright (c) 1992 Keith Muller. 6 * Copyright (c) 1992, 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * Keith Muller of the University of California, San Diego. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37#include <sys/cdefs.h> 38#ifndef lint 39#if 0 40static const char sccsid[] = "@(#)file_subs.c 8.1 (Berkeley) 5/31/93"; 41#else 42__used static const char rcsid[] = "$OpenBSD: file_subs.c,v 1.30 2005/11/09 19:59:06 otto Exp $"; 43#endif 44#endif /* not lint */ 45 46#include <sys/param.h> 47#include <sys/time.h> 48#include <sys/stat.h> 49#include <sys/uio.h> 50#include <err.h> 51#include <errno.h> 52#include <fcntl.h> 53#include <stdio.h> 54#include <stdlib.h> 55#include <string.h> 56#include <unistd.h> 57#include "pax.h" 58#include "options.h" 59#include "extern.h" 60 61static int 62mk_link(char *, struct stat *, char *, int); 63 64/* 65 * routines that deal with file operations such as: creating, removing; 66 * and setting access modes, uid/gid and times of files 67 */ 68 69#define FILEBITS (S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO) 70#define SETBITS (S_ISUID | S_ISGID) 71#define ABITS (FILEBITS | SETBITS) 72 73/* 74 * file_creat() 75 * Create and open a file. 76 * Return: 77 * file descriptor or -1 for failure 78 */ 79 80int 81file_creat(ARCHD *arcn) 82{ 83 int fd = -1; 84 mode_t file_mode; 85 int oerrno; 86 int rc = 0; 87 char *path_to_open; 88 char *new_path; 89 char *cwd; 90 char cwd_buff[MAXPATHLEN]; 91 92 /* 93 * Assume file doesn't exist, so just try to create it, most times this 94 * works. We have to take special handling when the file does exist. To 95 * detect this, we use O_EXCL. For example when trying to create a 96 * file and a character device or fifo exists with the same name, we 97 * can accidently open the device by mistake (or block waiting to open). 98 * If we find that the open has failed, then spend the effort to 99 * figure out why. This strategy was found to have better average 100 * performance in common use than checking the file (and the path) 101 * first with lstat. 102 */ 103 file_mode = arcn->sb.st_mode & FILEBITS; 104 if ((fd = open(arcn->name, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 105 file_mode)) >= 0) 106 return(fd); 107 108 /* 109 * the file seems to exist. First we try to get rid of it (found to be 110 * the second most common failure when traced). If this fails, only 111 * then we go to the expense to check and create the path to the file 112 */ 113 if (unlnk_exist(arcn->name, arcn->type) != 0) 114 return(-1); 115 116 path_to_open = arcn->name; 117 new_path = arcn->name; 118 cwd = getcwd(cwd_buff,sizeof(cwd_buff)); 119 if (cwd==NULL) return -1; 120 for (;;) { 121 /* 122 * try to open it again, if this fails, check all the nodes in 123 * the path and give it a final try. if chk_path() finds that 124 * it cannot fix anything, we will skip the last attempt 125 */ 126 if ((fd = open(path_to_open, O_WRONLY | O_CREAT | O_TRUNC, 127 file_mode)) >= 0) { 128 /* clean up the invalid_action */ 129 if (pax_invalid_action>0) { 130 record_pax_invalid_action_results(arcn, path_to_open); 131 } 132 break; 133 } 134 oerrno = errno; 135 if (pax_invalid_action>0) { 136 rc = perform_pax_invalid_action(arcn, oerrno); 137 if (rc == 0) continue; 138 if (rc == 1) { 139 fd = -1; 140 break; 141 } 142 } 143 /* rc == 2 reserved for -o invalid_action=write */ 144 if (nodirs || chk_path(path_to_open,arcn->sb.st_uid,arcn->sb.st_gid, 145 (rc==2) ? &new_path: NULL) < 0) { 146 syswarn((pax_invalid_action==0), oerrno, "Unable to create %s", arcn->name); 147 fd = -1; 148 break; 149 } 150 if (new_path) path_to_open = new_path; /* try again */ 151 } 152 if (new_path && strcmp(new_path, arcn->name)!=0) { 153 dochdir(cwd); /* go back to original directory */ 154 } 155 return(fd); 156} 157 158/* 159 * file_close() 160 * Close file descriptor to a file just created by pax. Sets modes, 161 * ownership and times as required. 162 * Return: 163 * 0 for success, -1 for failure 164 */ 165 166void 167file_close(ARCHD *arcn, int fd) 168{ 169 int res = 0; 170 171 if (fd < 0) 172 return; 173 174 if (close(fd) < 0) 175 syswarn(0, errno, "Unable to close file descriptor on %s", 176 arcn->name); 177 178 /* 179 * set owner/groups first as this may strip off mode bits we want 180 * then set file permission modes. Then set file access and 181 * modification times. 182 */ 183 if (pids) 184 res = set_ids(arcn->name, arcn->sb.st_uid, 185 arcn->sb.st_gid); 186 else 187 res = 1; /* without pids, pax should NOT set s bits */ 188 189 /* 190 * IMPORTANT SECURITY NOTE: 191 * if not preserving mode or we cannot set uid/gid, then PROHIBIT 192 * set uid/gid bits 193 */ 194 if (!pmode || res) 195 arcn->sb.st_mode &= ~(SETBITS); 196 if (pmode) 197 set_pmode(arcn->name, arcn->sb.st_mode); 198 if (patime || pmtime) 199 set_ftime(arcn->name, arcn->sb.st_mtime, arcn->sb.st_atime, 0); 200} 201 202/* 203 * lnk_creat() 204 * Create a hard link to arcn->ln_name from arcn->name. arcn->ln_name 205 * must exist; 206 * Return: 207 * 0 if ok, -1 otherwise 208 */ 209 210int 211lnk_creat(ARCHD *arcn) 212{ 213 struct stat sb; 214 215 /* 216 * we may be running as root, so we have to be sure that link target 217 * is not a directory, so we lstat and check 218 */ 219 if (lstat(arcn->ln_name, &sb) < 0) { 220 syswarn(1,errno,"Unable to link to %s from %s", arcn->ln_name, 221 arcn->name); 222 return(-1); 223 } 224 225 if (S_ISDIR(sb.st_mode)) { 226 paxwarn(1, "A hard link to the directory %s is not allowed", 227 arcn->ln_name); 228 return(-1); 229 } 230 231 if (S_ISLNK(sb.st_mode)) { 232 int res; 233 char buff[PATH_MAX+1]; 234 /* 235 * Conformance: cannot make hard link to symlink - just make a 236 * symlink to the target of the symlink 237 */ 238 if ((res = readlink(arcn->ln_name, buff, sizeof(buff)-1)) < 0) { 239 syswarn(1,errno,"Unable to symlink to %s from %s", arcn->ln_name, 240 arcn->name); 241 return(-1); 242 } 243 buff[res] = 0; 244 res = symlink(buff, arcn->name); 245 return res; 246 } 247 248 return(mk_link(arcn->ln_name, &sb, arcn->name, 0)); 249} 250 251/* 252 * cross_lnk() 253 * Create a hard link to arcn->org_name from arcn->name. Only used in copy 254 * with the -l flag. No warning or error if this does not succeed (we will 255 * then just create the file) 256 * Return: 257 * 1 if copy() should try to create this file node 258 * 0 if cross_lnk() ok, -1 for fatal flaw (like linking to self). 259 */ 260 261int 262cross_lnk(ARCHD *arcn) 263{ 264 /* 265 * try to make a link to original file (-l flag in copy mode). make 266 * sure we do not try to link to directories in case we are running as 267 * root (and it might succeed). 268 */ 269 if (arcn->type == PAX_DIR) 270 return(1); 271 if (arcn->type == PAX_SLK) { /* for Unix 03 conformance tests 202,203 */ 272 if (!Lflag) 273 return(1); 274 } 275 return(mk_link(arcn->org_name, &(arcn->sb), arcn->name, 1)); 276} 277 278/* 279 * chk_same() 280 * In copy mode if we are not trying to make hard links between the src 281 * and destinations, make sure we are not going to overwrite ourselves by 282 * accident. This slows things down a little, but we have to protect all 283 * those people who make typing errors. 284 * Return: 285 * 1 the target does not exist, go ahead and copy 286 * 0 skip it file exists (-k) or may be the same as source file 287 */ 288 289int 290chk_same(ARCHD *arcn) 291{ 292 struct stat sb; 293 294 /* 295 * if file does not exist, return. if file exists and -k, skip it 296 * quietly 297 */ 298 if (lstat(arcn->name, &sb) < 0) 299 return(1); 300 if (kflag) 301 return(0); 302 303 /* 304 * better make sure the user does not have src == dest by mistake 305 */ 306 if ((arcn->sb.st_dev == sb.st_dev) && (arcn->sb.st_ino == sb.st_ino)) { 307 paxwarn(1, "Unable to copy %s, file would overwrite itself", 308 arcn->name); 309 return(0); 310 } 311 return(1); 312} 313 314/* 315 * mk_link() 316 * try to make a hard link between two files. if ign set, we do not 317 * complain. 318 * Return: 319 * 0 if successful (or we are done with this file but no error, such as 320 * finding the from file exists and the user has set -k). 321 * 1 when ign was set to indicates we could not make the link but we 322 * should try to copy/extract the file as that might work (and is an 323 * allowed option). -1 an error occurred. 324 */ 325 326static int 327mk_link(char *to, struct stat *to_sb, char *from, int ign) 328{ 329 struct stat sb; 330 int oerrno; 331 332 /* 333 * if from file exists, it has to be unlinked to make the link. If the 334 * file exists and -k is set, skip it quietly 335 */ 336 if (lstat(from, &sb) == 0) { 337 if (kflag) 338 return(0); 339 340 /* 341 * make sure it is not the same file, protect the user 342 */ 343 if ((to_sb->st_dev==sb.st_dev)&&(to_sb->st_ino == sb.st_ino)) { 344 paxwarn(1, "Unable to link file %s to itself", to); 345 return(-1); 346 } 347 348 /* 349 * try to get rid of the file, based on the type 350 */ 351 if (S_ISDIR(sb.st_mode)) { 352 if (rmdir(from) < 0) { 353 syswarn(1, errno, "Unable to remove %s", from); 354 return(-1); 355 } 356 } else if (unlink(from) < 0) { 357 if (!ign) { 358 syswarn(1, errno, "Unable to remove %s", from); 359 return(-1); 360 } 361 return(1); 362 } 363 } 364 365 /* 366 * from file is gone (or did not exist), try to make the hard link. 367 * if it fails, check the path and try it again (if chk_path() says to 368 * try again) 369 */ 370 for (;;) { 371 if (link(to, from) == 0) 372 break; 373 oerrno = errno; 374 if (!nodirs && chk_path(from, to_sb->st_uid, to_sb->st_gid, NULL) == 0) 375 continue; 376 if (!ign) { 377 syswarn(1, oerrno, "Could not link to %s from %s", to, 378 from); 379 return(-1); 380 } 381 return(1); 382 } 383 384 /* 385 * all right the link was made 386 */ 387 return(0); 388} 389 390/* 391 * node_creat() 392 * create an entry in the file system (other than a file or hard link). 393 * If successful, sets uid/gid modes and times as required. 394 * Return: 395 * 0 if ok, -1 otherwise 396 */ 397 398int 399node_creat(ARCHD *arcn) 400{ 401 int res; 402 int ign = 0; 403 int oerrno; 404 int pass = 0; 405 mode_t file_mode; 406 struct stat sb; 407 char target[MAXPATHLEN]; 408 char *nm = arcn->name; 409 int nmlen = arcn->nlen; 410 int len; 411 412 /* 413 * create node based on type, if that fails try to unlink the node and 414 * try again. finally check the path and try again. As noted in the 415 * file and link creation routines, this method seems to exhibit the 416 * best performance in general use workloads. 417 */ 418 file_mode = arcn->sb.st_mode & FILEBITS; 419 420 for (;;) { 421 switch (arcn->type) { 422 case PAX_DIR: 423 /* 424 * If -h (or -L) was given in tar-mode, follow the 425 * potential symlink chain before trying to create the 426 * directory. 427 */ 428 if (strcmp(NM_TAR, argv0) == 0 && Lflag) { 429 while (lstat(nm, &sb) == 0 && 430 S_ISLNK(sb.st_mode)) { 431 len = readlink(nm, target, 432 sizeof target - 1); 433 if (len == -1) { 434 syswarn(0, errno, 435 "cannot follow symlink %s in chain for %s", 436 nm, arcn->name); 437 res = -1; 438 goto badlink; 439 } 440 target[len] = '\0'; 441 nm = target; 442 nmlen = len; 443 } 444 } 445 res = mkdir(nm, file_mode); 446 447badlink: 448 if (ign) 449 res = 0; 450 break; 451 case PAX_CHR: 452 file_mode |= S_IFCHR; 453 res = mknod(nm, file_mode, arcn->sb.st_rdev); 454 break; 455 case PAX_BLK: 456 file_mode |= S_IFBLK; 457 res = mknod(nm, file_mode, arcn->sb.st_rdev); 458 break; 459 case PAX_FIF: 460 res = mkfifo(nm, file_mode); 461 break; 462 case PAX_SCK: 463 /* 464 * Skip sockets, operation has no meaning under BSD 465 */ 466 paxwarn(0, 467 "%s skipped. Sockets cannot be copied or extracted", 468 nm); 469 return(-1); 470 case PAX_SLK: 471 res = symlink(arcn->ln_name, nm); 472 break; 473 case PAX_CTG: 474 case PAX_HLK: 475 case PAX_HRG: 476 case PAX_REG: 477 default: 478 /* 479 * we should never get here 480 */ 481 paxwarn(0, "%s has an unknown file type, skipping", 482 nm); 483 return(-1); 484 } 485 486 /* 487 * if we were able to create the node break out of the loop, 488 * otherwise try to unlink the node and try again. if that 489 * fails check the full path and try a final time. 490 */ 491 if (res == 0) 492 break; 493 494 /* 495 * we failed to make the node 496 */ 497 oerrno = errno; 498 if ((ign = unlnk_exist(nm, arcn->type)) < 0) 499 return(-1); 500 501 if (++pass <= 1) 502 continue; 503 504 if (nodirs || chk_path(nm,arcn->sb.st_uid,arcn->sb.st_gid, NULL) < 0) { 505 syswarn(1, oerrno, "Could not create: %s", nm); 506 return(-1); 507 } 508 } 509 510 /* 511 * we were able to create the node. set uid/gid, modes and times 512 */ 513 if (pids) 514 res = ((arcn->type == PAX_SLK) ? 515#if defined(__APPLE__) 516 /* Mac OS X doesn't have lchown, so don't bother */ 517 0 : 518#else 519 set_lids(nm, arcn->sb.st_uid, arcn->sb.st_gid) : 520#endif 521 set_ids(nm, arcn->sb.st_uid, arcn->sb.st_gid)); 522 else 523 res = 1; /* without pids, pax should NOT set s bits */ 524 525 /* 526 * symlinks are done now. 527 */ 528 if (arcn->type == PAX_SLK) 529 return(0); 530 531 /* 532 * IMPORTANT SECURITY NOTE: 533 * if not preserving mode or we cannot set uid/gid, then PROHIBIT any 534 * set uid/gid bits 535 */ 536 if (!pmode || res) 537 arcn->sb.st_mode &= ~(SETBITS); 538 if (pmode) 539 set_pmode(nm, arcn->sb.st_mode); 540 541 if (arcn->type == PAX_DIR && strcmp(NM_CPIO, argv0) != 0) { 542 /* 543 * Dirs must be processed again at end of extract to set times 544 * and modes to agree with those stored in the archive. However 545 * to allow extract to continue, we may have to also set owner 546 * rights. This allows nodes in the archive that are children 547 * of this directory to be extracted without failure. Both time 548 * and modes will be fixed after the entire archive is read and 549 * before pax exits. 550 */ 551 if (access(nm, R_OK | W_OK | X_OK) < 0) { 552 if (lstat(nm, &sb) < 0) { 553 syswarn(0, errno,"Could not access %s (stat)", 554 arcn->name); 555 set_pmode(nm,file_mode | S_IRWXU); 556 } else { 557 /* 558 * We have to add rights to the dir, so we make 559 * sure to restore the mode. The mode must be 560 * restored AS CREATED and not as stored if 561 * pmode is not set. 562 */ 563 set_pmode(nm, 564 ((sb.st_mode & FILEBITS) | S_IRWXU)); 565 if (!pmode) 566 arcn->sb.st_mode = sb.st_mode; 567 } 568 569 /* 570 * we have to force the mode to what was set here, 571 * since we changed it from the default as created. 572 */ 573 add_dir(nm, nmlen, &(arcn->sb), 1); 574 } else if (pmode || patime || pmtime) 575 add_dir(nm, nmlen, &(arcn->sb), 0); 576 } 577 578 if (patime || pmtime) 579 set_ftime(nm, arcn->sb.st_mtime, arcn->sb.st_atime, 0); 580 return(0); 581} 582 583/* 584 * unlnk_exist() 585 * Remove node from file system with the specified name. We pass the type 586 * of the node that is going to replace it. When we try to create a 587 * directory and find that it already exists, we allow processing to 588 * continue as proper modes etc will always be set for it later on. 589 * Return: 590 * 0 is ok to proceed, no file with the specified name exists 591 * -1 we were unable to remove the node, or we should not remove it (-k) 592 * 1 we found a directory and we were going to create a directory. 593 */ 594 595int 596unlnk_exist(char *name, int type) 597{ 598 struct stat sb; 599 600 /* 601 * the file does not exist, or -k we are done 602 */ 603 if (lstat(name, &sb) < 0) 604 return(0); 605 if (kflag) 606 return(-1); 607 608 if(strstr(name, "._") != NULL) /* remove when stat works properly */ 609 return(0); 610 611 if (S_ISDIR(sb.st_mode)) { 612 /* 613 * try to remove a directory, if it fails and we were going to 614 * create a directory anyway, tell the caller (return a 1) 615 */ 616 if (rmdir(name) < 0) { 617 if (type == PAX_DIR) 618 return(1); 619 syswarn(1,errno,"Unable to remove directory %s", name); 620 return(-1); 621 } 622 return(0); 623 } 624 625 /* 626 * try to get rid of all non-directory type nodes 627 */ 628 if (unlink(name) < 0) { 629 syswarn(1, errno, "Could not unlink %s", name); 630 return(-1); 631 } 632 return(0); 633} 634 635/* 636 * chk_path() 637 * We were trying to create some kind of node in the file system and it 638 * failed. chk_path() makes sure the path up to the node exists and is 639 * writeable. When we have to create a directory that is missing along the 640 * path somewhere, the directory we create will be set to the same 641 * uid/gid as the file has (when uid and gid are being preserved). 642 * NOTE: this routine is a real performance loss. It is only used as a 643 * last resort when trying to create entries in the file system. 644 * Return: 645 * -1 when it could find nothing it is allowed to fix. 646 * 0 otherwise 647 */ 648 649int 650chk_path(char *name, uid_t st_uid, gid_t st_gid, char ** new_name) 651{ 652 char *spt = name; 653 int namelen = strlen(name); 654 struct stat sb; 655 int retval = -1; 656 657 /* 658 * watch out for paths with nodes stored directly in / (e.g. /bozo) 659 */ 660 if (*spt == '/') 661 ++spt; 662 663 for (;;) { 664 /* 665 * work forward from the first / and check each part of the path 666 */ 667 spt = strchr(spt, '/'); 668 if (spt == NULL) 669 break; 670 *spt = '\0'; 671 672 /* 673 * if it exists we assume it is a directory, it is not within 674 * the spec (at least it seems to read that way) to alter the 675 * file system for nodes NOT EXPLICITLY stored on the archive. 676 * If that assumption is changed, you would test the node here 677 * and figure out how to get rid of it (probably like some 678 * recursive unlink()) or fix up the directory permissions if 679 * required (do an access()). 680 */ 681 if (lstat(name, &sb) == 0) { 682 *(spt++) = '/'; 683 if (new_name==NULL) continue; 684 retval = 0; /* accept it one directory at a time */ 685 break; 686 } 687 688 /* 689 * the path fails at this point, see if we can create the 690 * needed directory and continue on 691 */ 692 if (mkdir(name, S_IRWXU | S_IRWXG | S_IRWXO) < 0) { 693 *spt = '/'; 694 retval = -1; 695 break; 696 } 697 698 /* 699 * we were able to create the directory. We will tell the 700 * caller that we found something to fix, and it is ok to try 701 * and create the node again. 702 */ 703 retval = 0; 704 if (pids) 705 (void)set_ids(name, st_uid, st_gid); 706 707 /* 708 * make sure the user doesn't have some strange umask that 709 * causes this newly created directory to be unusable. We fix 710 * the modes and restore them back to the creation default at 711 * the end of pax 712 */ 713 if ((access(name, R_OK | W_OK | X_OK) < 0) && 714 (lstat(name, &sb) == 0)) { 715 set_pmode(name, ((sb.st_mode & FILEBITS) | S_IRWXU)); 716 add_dir(name, namelen, &sb, 1); 717 } 718 *(spt++) = '/'; 719 if (new_name==NULL) continue; 720 break; 721 } 722 if ((new_name != NULL) && retval==0) { 723 /* save the new path */ 724 *(--spt) = '\0'; 725 /* 726 printf ("chdir to %s\n", name); 727 */ 728 if(0==chdir(name)) { 729 *spt++ = '/'; 730 /* 731 printf ("remaining path: %s\n",spt); 732 */ 733 *new_name = spt; 734 } else 735 *spt = '/'; 736 } 737 return(retval); 738} 739 740/* 741 * set_ftime() 742 * Set the access time and modification time for a named file. If frc 743 * is non-zero we force these times to be set even if the user did not 744 * request access and/or modification time preservation (this is also 745 * used by -t to reset access times). 746 * When frc is zero, only those times the user has asked for are set, the 747 * other ones are left alone. We do not assume the un-documented feature 748 * of many utimes() implementations that consider a 0 time value as a do 749 * not set request. 750 */ 751 752void 753set_ftime(char *fnm, time_t mtime, time_t atime, int frc) 754{ 755 static struct timeval tv[2] = {{0L, 0L}, {0L, 0L}}; 756 struct stat sb; 757 758 tv[0].tv_sec = (long)atime; 759 tv[1].tv_sec = (long)mtime; 760 if (!frc && (!patime || !pmtime)) { 761 /* 762 * if we are not forcing, only set those times the user wants 763 * set. We get the current values of the times if we need them. 764 */ 765 if (lstat(fnm, &sb) == 0) { 766 if (!patime) 767 tv[0].tv_sec = (long)sb.st_atime; 768 if (!pmtime) 769 tv[1].tv_sec = (long)sb.st_mtime; 770 } else 771 syswarn(0,errno,"Unable to obtain file stats %s", fnm); 772 } 773 774 /* 775 * set the times 776 */ 777 if (pax_invalid_action_write_cwd) { 778 char cwd_buff[MAXPATHLEN]; 779 char * cwd; 780 cwd = getcwd(&cwd_buff[0],MAXPATHLEN); 781 chdir(pax_invalid_action_write_cwd); 782 if (utimes(pax_invalid_action_write_path, tv) < 0) 783 syswarn(1, errno, "Access/modification time set failed on: %s", 784 pax_invalid_action_write_path); 785 chdir(cwd); 786 cleanup_pax_invalid_action(); 787 } else { 788 if (utimes(fnm, tv) < 0) 789 syswarn(1, errno, "Access/modification time set failed on: %s", 790 fnm); 791 } 792 return; 793} 794 795void 796fset_ftime(char *fnm, int fd, time_t mtime, time_t atime, int frc) 797{ 798 static struct timeval tv[2] = {{0L, 0L}, {0L, 0L}}; 799 struct stat sb; 800 801 tv[0].tv_sec = (long)atime; 802 tv[1].tv_sec = (long)mtime; 803 if (!frc && (!patime || !pmtime)) { 804 /* 805 * if we are not forcing, only set those times the user wants 806 * set. We get the current values of the times if we need them. 807 */ 808 if (fstat(fd, &sb) == 0) { 809 if (!patime) 810 tv[0].tv_sec = (long)sb.st_atime; 811 if (!pmtime) 812 tv[1].tv_sec = (long)sb.st_mtime; 813 } else 814 syswarn(0,errno,"Unable to obtain file stats %s", fnm); 815 } 816 /* 817 * set the times 818 */ 819 if (futimes(fd, tv) < 0) 820 syswarn(1, errno, "Access/modification time set failed on: %s", 821 fnm); 822 return; 823} 824 825/* 826 * set_ids() 827 * set the uid and gid of a file system node 828 * Return: 829 * 0 when set, -1 on failure 830 */ 831 832int 833set_ids(char *fnm, uid_t uid, gid_t gid) 834{ 835 if (chown(fnm, uid, gid) < 0) { 836 /* 837 * ignore EPERM unless in verbose mode or being run by root. 838 * if running as pax, POSIX requires a warning. 839 */ 840 if (strcmp(NM_PAX, argv0) == 0 || errno != EPERM || vflag || 841 geteuid() == 0) 842 syswarn(1, errno, "Unable to set file uid/gid of %s", 843 fnm); 844 return(-1); 845 } 846 return(0); 847} 848 849int 850fset_ids(char *fnm, int fd, uid_t uid, gid_t gid) 851{ 852 if (fchown(fd, uid, gid) < 0) { 853 /* 854 * ignore EPERM unless in verbose mode or being run by root. 855 * if running as pax, POSIX requires a warning. 856 */ 857 if (strcmp(NM_PAX, argv0) == 0 || errno != EPERM || vflag || 858 geteuid() == 0) 859 syswarn(1, errno, "Unable to set file uid/gid of %s", 860 fnm); 861 return(-1); 862 } 863 return(0); 864} 865 866#if !defined(__APPLE__) 867/* 868 * set_lids() 869 * set the uid and gid of a file system node 870 * Return: 871 * 0 when set, -1 on failure 872 */ 873 874int 875set_lids(char *fnm, uid_t uid, gid_t gid) 876{ 877 if (lchown(fnm, uid, gid) < 0) { 878 /* 879 * ignore EPERM unless in verbose mode or being run by root. 880 * if running as pax, POSIX requires a warning. 881 */ 882 if (strcmp(NM_PAX, argv0) == 0 || errno != EPERM || vflag || 883 geteuid() == 0) 884 syswarn(1, errno, "Unable to set file uid/gid of %s", 885 fnm); 886 return(-1); 887 } 888 return(0); 889} 890#endif /* !__APPLE__ */ 891 892/* 893 * set_pmode() 894 * Set file access mode 895 */ 896 897void 898set_pmode(char *fnm, mode_t mode) 899{ 900 mode &= ABITS; 901 if (chmod(fnm, mode) < 0) 902 syswarn(1, errno, "Could not set permissions on %s", fnm); 903 return; 904} 905 906void 907fset_pmode(char *fnm, int fd, mode_t mode) 908{ 909 mode &= ABITS; 910 if (fchmod(fd, mode) < 0) 911 syswarn(1, errno, "Could not set permissions on %s", fnm); 912 return; 913} 914 915/* 916 * file_write() 917 * Write/copy a file (during copy or archive extract). This routine knows 918 * how to copy files with lseek holes in it. (Which are read as file 919 * blocks containing all 0's but do not have any file blocks associated 920 * with the data). Typical examples of these are files created by dbm 921 * variants (.pag files). While the file size of these files are huge, the 922 * actual storage is quite small (the files are sparse). The problem is 923 * the holes read as all zeros so are probably stored on the archive that 924 * way (there is no way to determine if the file block is really a hole, 925 * we only know that a file block of all zero's can be a hole). 926 * At this writing, no major archive format knows how to archive files 927 * with holes. However, on extraction (or during copy, -rw) we have to 928 * deal with these files. Without detecting the holes, the files can 929 * consume a lot of file space if just written to disk. This replacement 930 * for write when passed the basic allocation size of a file system block, 931 * uses lseek whenever it detects the input data is all 0 within that 932 * file block. In more detail, the strategy is as follows: 933 * While the input is all zero keep doing an lseek. Keep track of when we 934 * pass over file block boundaries. Only write when we hit a non zero 935 * input. once we have written a file block, we continue to write it to 936 * the end (we stop looking at the input). When we reach the start of the 937 * next file block, start checking for zero blocks again. Working on file 938 * block boundaries significantly reduces the overhead when copying files 939 * that are NOT very sparse. This overhead (when compared to a write) is 940 * almost below the measurement resolution on many systems. Without it, 941 * files with holes cannot be safely copied. It does has a side effect as 942 * it can put holes into files that did not have them before, but that is 943 * not a problem since the file contents are unchanged (in fact it saves 944 * file space). (Except on paging files for diskless clients. But since we 945 * cannot determine one of those file from here, we ignore them). If this 946 * ever ends up on a system where CTG files are supported and the holes 947 * are not desired, just do a conditional test in those routines that 948 * call file_write() and have it call write() instead. BEFORE CLOSING THE 949 * FILE, make sure to call file_flush() when the last write finishes with 950 * an empty block. A lot of file systems will not create an lseek hole at 951 * the end. In this case we drop a single 0 at the end to force the 952 * trailing 0's in the file. 953 * ---Parameters--- 954 * rem: how many bytes left in this file system block 955 * isempt: have we written to the file block yet (is it empty) 956 * sz: basic file block allocation size 957 * cnt: number of bytes on this write 958 * str: buffer to write 959 * Return: 960 * number of bytes written, -1 on write (or lseek) error. 961 */ 962 963int 964file_write(int fd, char *str, int cnt, int *rem, int *isempt, int sz, 965 char *name) 966{ 967 char *pt; 968 char *end; 969 int wcnt; 970 char *st = str; 971 char **strp; 972 973 /* 974 * while we have data to process 975 */ 976 while (cnt) { 977 if (!*rem) { 978 /* 979 * We are now at the start of file system block again 980 * (or what we think one is...). start looking for 981 * empty blocks again 982 */ 983 *isempt = 1; 984 *rem = sz; 985 } 986 987 /* 988 * only examine up to the end of the current file block or 989 * remaining characters to write, whatever is smaller 990 */ 991 wcnt = MIN(cnt, *rem); 992 cnt -= wcnt; 993 *rem -= wcnt; 994 if (*isempt) { 995 /* 996 * have not written to this block yet, so we keep 997 * looking for zero's 998 */ 999 pt = st; 1000 end = st + wcnt; 1001 1002 /* 1003 * look for a zero filled buffer 1004 */ 1005 while ((pt < end) && (*pt == '\0')) 1006 ++pt; 1007 1008 if (pt == end) { 1009 /* 1010 * skip, buf is empty so far 1011 */ 1012 if (fd > -1 && 1013 lseek(fd, (off_t)wcnt, SEEK_CUR) < 0) { 1014 syswarn(1,errno,"File seek on %s", 1015 name); 1016 return(-1); 1017 } 1018 st = pt; 1019 continue; 1020 } 1021 /* 1022 * drat, the buf is not zero filled 1023 */ 1024 *isempt = 0; 1025 } 1026 1027 /* 1028 * have non-zero data in this file system block, have to write 1029 */ 1030 switch (fd) { 1031 case -1: 1032 strp = &gnu_name_string; 1033 break; 1034 case -2: 1035 strp = &gnu_link_string; 1036 break; 1037 default: 1038 strp = NULL; 1039 break; 1040 } 1041 if (strp) { 1042 if (*strp) 1043 err(1, "WARNING! Major Internal Error! GNU hack Failing!"); 1044 *strp = malloc(wcnt + 1); 1045 if (*strp == NULL) { 1046 paxwarn(1, "Out of memory"); 1047 return(-1); 1048 } 1049 memcpy(*strp, st, wcnt); 1050 (*strp)[wcnt] = '\0'; 1051 break; 1052 } else if (write(fd, st, wcnt) != wcnt) { 1053 syswarn(1, errno, "Failed write to file %s", name); 1054 return(-1); 1055 } 1056 st += wcnt; 1057 } 1058 return(st - str); 1059} 1060 1061/* 1062 * file_flush() 1063 * when the last file block in a file is zero, many file systems will not 1064 * let us create a hole at the end. To get the last block with zeros, we 1065 * write the last BYTE with a zero (back up one byte and write a zero). 1066 */ 1067 1068void 1069file_flush(int fd, char *fname, int isempt) 1070{ 1071 static char blnk[] = "\0"; 1072 1073 /* 1074 * silly test, but make sure we are only called when the last block is 1075 * filled with all zeros. 1076 */ 1077 if (!isempt) 1078 return; 1079 1080 /* 1081 * move back one byte and write a zero 1082 */ 1083 if (lseek(fd, (off_t)-1, SEEK_CUR) < 0) { 1084 syswarn(1, errno, "Failed seek on file %s", fname); 1085 return; 1086 } 1087 1088 if (write(fd, blnk, 1) < 0) 1089 syswarn(1, errno, "Failed write to file %s", fname); 1090 return; 1091} 1092 1093/* 1094 * rdfile_close() 1095 * close a file we have beed reading (to copy or archive). If we have to 1096 * reset access time (tflag) do so (the times are stored in arcn). 1097 */ 1098 1099void 1100rdfile_close(ARCHD *arcn, int *fd) 1101{ 1102 /* 1103 * make sure the file is open 1104 */ 1105 if (*fd < 0) 1106 return; 1107 1108 (void)close(*fd); 1109 *fd = -1; 1110 if (!tflag) 1111 return; 1112 1113 /* 1114 * user wants last access time reset 1115 */ 1116 set_ftime(arcn->org_name, arcn->sb.st_mtime, arcn->sb.st_atime, 1); 1117 return; 1118} 1119 1120/* 1121 * set_crc() 1122 * read a file to calculate its crc. This is a real drag. Archive formats 1123 * that have this, end up reading the file twice (we have to write the 1124 * header WITH the crc before writing the file contents. Oh well... 1125 * Return: 1126 * 0 if was able to calculate the crc, -1 otherwise 1127 */ 1128 1129int 1130set_crc(ARCHD *arcn, int fd) 1131{ 1132 int i; 1133 int res; 1134 off_t cpcnt = 0L; 1135 u_long size; 1136 u_int32_t crc = 0; 1137 char tbuf[FILEBLK]; 1138 struct stat sb; 1139 1140 if (fd < 0) { 1141 /* 1142 * hmm, no fd, should never happen. well no crc then. 1143 */ 1144 arcn->crc = 0L; 1145 return(0); 1146 } 1147 1148 if ((size = (u_long)arcn->sb.st_blksize) > (u_long)sizeof(tbuf)) 1149 size = (u_long)sizeof(tbuf); 1150 1151 /* 1152 * read all the bytes we think that there are in the file. If the user 1153 * is trying to archive an active file, forget this file. 1154 */ 1155 for (;;) { 1156 if ((res = read(fd, tbuf, size)) <= 0) 1157 break; 1158 cpcnt += res; 1159 for (i = 0; i < res; ++i) 1160 crc += (tbuf[i] & 0xff); 1161 } 1162 1163 /* 1164 * safety check. we want to avoid archiving files that are active as 1165 * they can create inconsistent archive copies. 1166 */ 1167 if (cpcnt != arcn->sb.st_size) 1168 paxwarn(1, "File changed size %s", arcn->org_name); 1169 else if (fstat(fd, &sb) < 0) 1170 syswarn(1, errno, "Failed stat on %s", arcn->org_name); 1171 else if (arcn->sb.st_mtime != sb.st_mtime) 1172 paxwarn(1, "File %s was modified during read", arcn->org_name); 1173 else if (lseek(fd, (off_t)0L, SEEK_SET) < 0) 1174 syswarn(1, errno, "File rewind failed on: %s", arcn->org_name); 1175 else { 1176 arcn->crc = crc; 1177 return(0); 1178 } 1179 return(-1); 1180} 1181