1 /*- 2 * Copyright (c) 1992 Keith Muller. 3 * Copyright (c) 1992, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Keith Muller of the University of California, San Diego. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)file_subs.c 8.1 (Berkeley) 5/31/93 38 * $FreeBSD: src/bin/pax/file_subs.c,v 1.12.2.1 2001/08/01 05:03:11 obrien Exp $ 39 * $DragonFly: src/bin/pax/file_subs.c,v 1.2 2003/06/17 04:22:50 dillon Exp $ 40 */ 41 42 #include <sys/types.h> 43 #include <sys/time.h> 44 #include <sys/stat.h> 45 #include <unistd.h> 46 #include <fcntl.h> 47 #include <string.h> 48 #include <stdio.h> 49 #include <errno.h> 50 #include <sys/uio.h> 51 #include <stdlib.h> 52 #include "pax.h" 53 #include "options.h" 54 #include "extern.h" 55 56 static int 57 mk_link __P((register char *,register struct stat *,register char *, int)); 58 59 /* 60 * routines that deal with file operations such as: creating, removing; 61 * and setting access modes, uid/gid and times of files 62 */ 63 64 #define FILEBITS (S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO) 65 #define SETBITS (S_ISUID | S_ISGID) 66 #define ABITS (FILEBITS | SETBITS) 67 68 /* 69 * file_creat() 70 * Create and open a file. 71 * Return: 72 * file descriptor or -1 for failure 73 */ 74 75 #ifdef __STDC__ 76 int 77 file_creat(register ARCHD *arcn) 78 #else 79 int 80 file_creat(arcn) 81 register ARCHD *arcn; 82 #endif 83 { 84 int fd = -1; 85 mode_t file_mode; 86 int oerrno; 87 88 /* 89 * assume file doesn't exist, so just try to create it, most times this 90 * works. We have to take special handling when the file does exist. To 91 * detect this, we use O_EXCL. For example when trying to create a 92 * file and a character device or fifo exists with the same name, we 93 * can accidently open the device by mistake (or block waiting to open) 94 * If we find that the open has failed, then figure spend the effort to 95 * figure out why. This strategy was found to have better average 96 * performance in common use than checking the file (and the path) 97 * first with lstat. 98 */ 99 file_mode = arcn->sb.st_mode & FILEBITS; 100 if ((fd = open(arcn->name, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 101 file_mode)) >= 0) 102 return(fd); 103 104 /* 105 * the file seems to exist. First we try to get rid of it (found to be 106 * the second most common failure when traced). If this fails, only 107 * then we go to the expense to check and create the path to the file 108 */ 109 if (unlnk_exist(arcn->name, arcn->type) != 0) 110 return(-1); 111 112 for (;;) { 113 /* 114 * try to open it again, if this fails, check all the nodes in 115 * the path and give it a final try. if chk_path() finds that 116 * it cannot fix anything, we will skip the last attempt 117 */ 118 if ((fd = open(arcn->name, O_WRONLY | O_CREAT | O_TRUNC, 119 file_mode)) >= 0) 120 break; 121 oerrno = errno; 122 if (nodirs || chk_path(arcn->name,arcn->sb.st_uid,arcn->sb.st_gid) < 0) { 123 syswarn(1, oerrno, "Unable to create %s", arcn->name); 124 return(-1); 125 } 126 } 127 return(fd); 128 } 129 130 /* 131 * file_close() 132 * Close file descriptor to a file just created by pax. Sets modes, 133 * ownership and times as required. 134 * Return: 135 * 0 for success, -1 for failure 136 */ 137 138 #ifdef __STDC__ 139 void 140 file_close(register ARCHD *arcn, int fd) 141 #else 142 void 143 file_close(arcn, fd) 144 register ARCHD *arcn; 145 int fd; 146 #endif 147 { 148 int res = 0; 149 150 if (fd < 0) 151 return; 152 if (close(fd) < 0) 153 syswarn(0, errno, "Unable to close file descriptor on %s", 154 arcn->name); 155 156 /* 157 * set owner/groups first as this may strip off mode bits we want 158 * then set file permission modes. Then set file access and 159 * modification times. 160 */ 161 if (pids) 162 res = set_ids(arcn->name, arcn->sb.st_uid, arcn->sb.st_gid); 163 164 /* 165 * IMPORTANT SECURITY NOTE: 166 * if not preserving mode or we cannot set uid/gid, then PROHIBIT 167 * set uid/gid bits 168 */ 169 if (!pmode || res) 170 arcn->sb.st_mode &= ~(SETBITS); 171 if (pmode) 172 set_pmode(arcn->name, arcn->sb.st_mode); 173 if (patime || pmtime) 174 set_ftime(arcn->name, arcn->sb.st_mtime, arcn->sb.st_atime, 0); 175 } 176 177 /* 178 * lnk_creat() 179 * Create a hard link to arcn->ln_name from arcn->name. arcn->ln_name 180 * must exist; 181 * Return: 182 * 0 if ok, -1 otherwise 183 */ 184 185 #ifdef __STDC__ 186 int 187 lnk_creat(register ARCHD *arcn) 188 #else 189 int 190 lnk_creat(arcn) 191 register ARCHD *arcn; 192 #endif 193 { 194 struct stat sb; 195 196 /* 197 * we may be running as root, so we have to be sure that link target 198 * is not a directory, so we lstat and check 199 */ 200 if (lstat(arcn->ln_name, &sb) < 0) { 201 syswarn(1,errno,"Unable to link to %s from %s", arcn->ln_name, 202 arcn->name); 203 return(-1); 204 } 205 206 if (S_ISDIR(sb.st_mode)) { 207 paxwarn(1, "A hard link to the directory %s is not allowed", 208 arcn->ln_name); 209 return(-1); 210 } 211 212 return(mk_link(arcn->ln_name, &sb, arcn->name, 0)); 213 } 214 215 /* 216 * cross_lnk() 217 * Create a hard link to arcn->org_name from arcn->name. Only used in copy 218 * with the -l flag. No warning or error if this does not succeed (we will 219 * then just create the file) 220 * Return: 221 * 1 if copy() should try to create this file node 222 * 0 if cross_lnk() ok, -1 for fatal flaw (like linking to self). 223 */ 224 225 #ifdef __STDC__ 226 int 227 cross_lnk(register ARCHD *arcn) 228 #else 229 int 230 cross_lnk(arcn) 231 register ARCHD *arcn; 232 #endif 233 { 234 /* 235 * try to make a link to original file (-l flag in copy mode). make sure 236 * we do not try to link to directories in case we are running as root 237 * (and it might succeed). 238 */ 239 if (arcn->type == PAX_DIR) 240 return(1); 241 return(mk_link(arcn->org_name, &(arcn->sb), arcn->name, 1)); 242 } 243 244 /* 245 * chk_same() 246 * In copy mode if we are not trying to make hard links between the src 247 * and destinations, make sure we are not going to overwrite ourselves by 248 * accident. This slows things down a little, but we have to protect all 249 * those people who make typing errors. 250 * Return: 251 * 1 the target does not exist, go ahead and copy 252 * 0 skip it file exists (-k) or may be the same as source file 253 */ 254 255 #ifdef __STDC__ 256 int 257 chk_same(register ARCHD *arcn) 258 #else 259 int 260 chk_same(arcn) 261 register ARCHD *arcn; 262 #endif 263 { 264 struct stat sb; 265 266 /* 267 * if file does not exist, return. if file exists and -k, skip it 268 * quietly 269 */ 270 if (lstat(arcn->name, &sb) < 0) 271 return(1); 272 if (kflag) 273 return(0); 274 275 /* 276 * better make sure the user does not have src == dest by mistake 277 */ 278 if ((arcn->sb.st_dev == sb.st_dev) && (arcn->sb.st_ino == sb.st_ino)) { 279 paxwarn(1, "Unable to copy %s, file would overwrite itself", 280 arcn->name); 281 return(0); 282 } 283 return(1); 284 } 285 286 /* 287 * mk_link() 288 * try to make a hard link between two files. if ign set, we do not 289 * complain. 290 * Return: 291 * 0 if successful (or we are done with this file but no error, such as 292 * finding the from file exists and the user has set -k). 293 * 1 when ign was set to indicates we could not make the link but we 294 * should try to copy/extract the file as that might work (and is an 295 * allowed option). -1 an error occurred. 296 */ 297 298 #ifdef __STDC__ 299 static int 300 mk_link(register char *to, register struct stat *to_sb, register char *from, 301 int ign) 302 #else 303 static int 304 mk_link(to, to_sb, from, ign) 305 register char *to; 306 register struct stat *to_sb; 307 register char *from; 308 int ign; 309 #endif 310 { 311 struct stat sb; 312 int oerrno; 313 314 /* 315 * if from file exists, it has to be unlinked to make the link. If the 316 * file exists and -k is set, skip it quietly 317 */ 318 if (lstat(from, &sb) == 0) { 319 if (kflag) 320 return(0); 321 322 /* 323 * make sure it is not the same file, protect the user 324 */ 325 if ((to_sb->st_dev==sb.st_dev)&&(to_sb->st_ino == sb.st_ino)) { 326 paxwarn(1, "Unable to link file %s to itself", to); 327 return(-1);; 328 } 329 330 /* 331 * try to get rid of the file, based on the type 332 */ 333 if (S_ISDIR(sb.st_mode)) { 334 if (rmdir(from) < 0) { 335 syswarn(1, errno, "Unable to remove %s", from); 336 return(-1); 337 } 338 } else if (unlink(from) < 0) { 339 if (!ign) { 340 syswarn(1, errno, "Unable to remove %s", from); 341 return(-1); 342 } 343 return(1); 344 } 345 } 346 347 /* 348 * from file is gone (or did not exist), try to make the hard link. 349 * if it fails, check the path and try it again (if chk_path() says to 350 * try again) 351 */ 352 for (;;) { 353 if (link(to, from) == 0) 354 break; 355 oerrno = errno; 356 if (!nodirs && chk_path(from, to_sb->st_uid, to_sb->st_gid) == 0) 357 continue; 358 if (!ign) { 359 syswarn(1, oerrno, "Could not link to %s from %s", to, 360 from); 361 return(-1); 362 } 363 return(1); 364 } 365 366 /* 367 * all right the link was made 368 */ 369 return(0); 370 } 371 372 /* 373 * node_creat() 374 * create an entry in the file system (other than a file or hard link). 375 * If successful, sets uid/gid modes and times as required. 376 * Return: 377 * 0 if ok, -1 otherwise 378 */ 379 380 #ifdef __STDC__ 381 int 382 node_creat(register ARCHD *arcn) 383 #else 384 int 385 node_creat(arcn) 386 register ARCHD *arcn; 387 #endif 388 { 389 register int res; 390 register int ign = 0; 391 register int oerrno; 392 register int pass = 0; 393 mode_t file_mode; 394 struct stat sb; 395 396 /* 397 * create node based on type, if that fails try to unlink the node and 398 * try again. finally check the path and try again. As noted in the 399 * file and link creation routines, this method seems to exhibit the 400 * best performance in general use workloads. 401 */ 402 file_mode = arcn->sb.st_mode & FILEBITS; 403 404 for (;;) { 405 switch(arcn->type) { 406 case PAX_DIR: 407 res = mkdir(arcn->name, file_mode); 408 if (ign) 409 res = 0; 410 break; 411 case PAX_CHR: 412 file_mode |= S_IFCHR; 413 res = mknod(arcn->name, file_mode, arcn->sb.st_rdev); 414 break; 415 case PAX_BLK: 416 file_mode |= S_IFBLK; 417 res = mknod(arcn->name, file_mode, arcn->sb.st_rdev); 418 break; 419 case PAX_FIF: 420 res = mkfifo(arcn->name, file_mode); 421 break; 422 case PAX_SCK: 423 /* 424 * Skip sockets, operation has no meaning under BSD 425 */ 426 paxwarn(0, 427 "%s skipped. Sockets cannot be copied or extracted", 428 arcn->name); 429 return(-1); 430 case PAX_SLK: 431 res = symlink(arcn->ln_name, arcn->name); 432 break; 433 case PAX_CTG: 434 case PAX_HLK: 435 case PAX_HRG: 436 case PAX_REG: 437 default: 438 /* 439 * we should never get here 440 */ 441 paxwarn(0, "%s has an unknown file type, skipping", 442 arcn->name); 443 return(-1); 444 } 445 446 /* 447 * if we were able to create the node break out of the loop, 448 * otherwise try to unlink the node and try again. if that 449 * fails check the full path and try a final time. 450 */ 451 if (res == 0) 452 break; 453 454 /* 455 * we failed to make the node 456 */ 457 oerrno = errno; 458 if ((ign = unlnk_exist(arcn->name, arcn->type)) < 0) 459 return(-1); 460 461 if (++pass <= 1) 462 continue; 463 464 if (nodirs || chk_path(arcn->name,arcn->sb.st_uid,arcn->sb.st_gid) < 0) { 465 syswarn(1, oerrno, "Could not create: %s", arcn->name); 466 return(-1); 467 } 468 } 469 470 /* 471 * we were able to create the node. set uid/gid, modes and times 472 */ 473 if (pids) 474 res = ((arcn->type == PAX_SLK) ? 475 set_lids(arcn->name, arcn->sb.st_uid, arcn->sb.st_gid) : 476 set_ids(arcn->name, arcn->sb.st_uid, arcn->sb.st_gid)); 477 else 478 res = 0; 479 480 /* 481 * symlinks are done now. 482 */ 483 if (arcn->type == PAX_SLK) 484 return(0); 485 486 /* 487 * IMPORTANT SECURITY NOTE: 488 * if not preserving mode or we cannot set uid/gid, then PROHIBIT any 489 * set uid/gid bits 490 */ 491 if (!pmode || res) 492 arcn->sb.st_mode &= ~(SETBITS); 493 if (pmode) 494 set_pmode(arcn->name, arcn->sb.st_mode); 495 496 if (arcn->type == PAX_DIR && strcmp(NM_CPIO, argv0) != 0) { 497 /* 498 * Dirs must be processed again at end of extract to set times 499 * and modes to agree with those stored in the archive. However 500 * to allow extract to continue, we may have to also set owner 501 * rights. This allows nodes in the archive that are children 502 * of this directory to be extracted without failure. Both time 503 * and modes will be fixed after the entire archive is read and 504 * before pax exits. 505 */ 506 if (access(arcn->name, R_OK | W_OK | X_OK) < 0) { 507 if (lstat(arcn->name, &sb) < 0) { 508 syswarn(0, errno,"Could not access %s (stat)", 509 arcn->name); 510 set_pmode(arcn->name,file_mode | S_IRWXU); 511 } else { 512 /* 513 * We have to add rights to the dir, so we make 514 * sure to restore the mode. The mode must be 515 * restored AS CREATED and not as stored if 516 * pmode is not set. 517 */ 518 set_pmode(arcn->name, 519 ((sb.st_mode & FILEBITS) | S_IRWXU)); 520 if (!pmode) 521 arcn->sb.st_mode = sb.st_mode; 522 } 523 524 /* 525 * we have to force the mode to what was set here, 526 * since we changed it from the default as created. 527 */ 528 add_dir(arcn->name, arcn->nlen, &(arcn->sb), 1); 529 } else if (pmode || patime || pmtime) 530 add_dir(arcn->name, arcn->nlen, &(arcn->sb), 0); 531 } 532 533 if (patime || pmtime) 534 set_ftime(arcn->name, arcn->sb.st_mtime, arcn->sb.st_atime, 0); 535 return(0); 536 } 537 538 /* 539 * unlnk_exist() 540 * Remove node from file system with the specified name. We pass the type 541 * of the node that is going to replace it. When we try to create a 542 * directory and find that it already exists, we allow processing to 543 * continue as proper modes etc will always be set for it later on. 544 * Return: 545 * 0 is ok to proceed, no file with the specified name exists 546 * -1 we were unable to remove the node, or we should not remove it (-k) 547 * 1 we found a directory and we were going to create a directory. 548 */ 549 550 #ifdef __STDC__ 551 int 552 unlnk_exist(register char *name, register int type) 553 #else 554 int 555 unlnk_exist(name, type) 556 register char *name; 557 register int type; 558 #endif 559 { 560 struct stat sb; 561 562 /* 563 * the file does not exist, or -k we are done 564 */ 565 if (lstat(name, &sb) < 0) 566 return(0); 567 if (kflag) 568 return(-1); 569 570 if (S_ISDIR(sb.st_mode)) { 571 /* 572 * try to remove a directory, if it fails and we were going to 573 * create a directory anyway, tell the caller (return a 1) 574 */ 575 if (rmdir(name) < 0) { 576 if (type == PAX_DIR) 577 return(1); 578 syswarn(1,errno,"Unable to remove directory %s", name); 579 return(-1); 580 } 581 return(0); 582 } 583 584 /* 585 * try to get rid of all non-directory type nodes 586 */ 587 if (unlink(name) < 0) { 588 syswarn(1, errno, "Could not unlink %s", name); 589 return(-1); 590 } 591 return(0); 592 } 593 594 /* 595 * chk_path() 596 * We were trying to create some kind of node in the file system and it 597 * failed. chk_path() makes sure the path up to the node exists and is 598 * writeable. When we have to create a directory that is missing along the 599 * path somewhere, the directory we create will be set to the same 600 * uid/gid as the file has (when uid and gid are being preserved). 601 * NOTE: this routine is a real performance loss. It is only used as a 602 * last resort when trying to create entries in the file system. 603 * Return: 604 * -1 when it could find nothing it is allowed to fix. 605 * 0 otherwise 606 */ 607 608 #ifdef __STDC__ 609 int 610 chk_path( register char *name, uid_t st_uid, gid_t st_gid) 611 #else 612 int 613 chk_path(name, st_uid, st_gid) 614 register char *name; 615 uid_t st_uid; 616 gid_t st_gid; 617 #endif 618 { 619 register char *spt = name; 620 struct stat sb; 621 int retval = -1; 622 623 /* 624 * watch out for paths with nodes stored directly in / (e.g. /bozo) 625 */ 626 if (*spt == '/') 627 ++spt; 628 629 for(;;) { 630 /* 631 * work foward from the first / and check each part of the path 632 */ 633 spt = strchr(spt, '/'); 634 if (spt == NULL) 635 break; 636 *spt = '\0'; 637 638 /* 639 * if it exists we assume it is a directory, it is not within 640 * the spec (at least it seems to read that way) to alter the 641 * file system for nodes NOT EXPLICITLY stored on the archive. 642 * If that assumption is changed, you would test the node here 643 * and figure out how to get rid of it (probably like some 644 * recursive unlink()) or fix up the directory permissions if 645 * required (do an access()). 646 */ 647 if (lstat(name, &sb) == 0) { 648 *(spt++) = '/'; 649 continue; 650 } 651 652 /* 653 * the path fails at this point, see if we can create the 654 * needed directory and continue on 655 */ 656 if (mkdir(name, S_IRWXU | S_IRWXG | S_IRWXO) < 0) { 657 *spt = '/'; 658 retval = -1; 659 break; 660 } 661 662 /* 663 * we were able to create the directory. We will tell the 664 * caller that we found something to fix, and it is ok to try 665 * and create the node again. 666 */ 667 retval = 0; 668 if (pids) 669 (void)set_ids(name, st_uid, st_gid); 670 671 /* 672 * make sure the user doen't have some strange umask that 673 * causes this newly created directory to be unusable. We fix 674 * the modes and restore them back to the creation default at 675 * the end of pax 676 */ 677 if ((access(name, R_OK | W_OK | X_OK) < 0) && 678 (lstat(name, &sb) == 0)) { 679 set_pmode(name, ((sb.st_mode & FILEBITS) | S_IRWXU)); 680 add_dir(name, spt - name, &sb, 1); 681 } 682 *(spt++) = '/'; 683 continue; 684 } 685 return(retval); 686 } 687 688 /* 689 * set_ftime() 690 * Set the access time and modification time for a named file. If frc is 691 * non-zero we force these times to be set even if the user did not 692 * request access and/or modification time preservation (this is also 693 * used by -t to reset access times). 694 * When ign is zero, only those times the user has asked for are set, the 695 * other ones are left alone. We do not assume the un-documented feature 696 * of many utimes() implementations that consider a 0 time value as a do 697 * not set request. 698 */ 699 700 #ifdef __STDC__ 701 void 702 set_ftime(char *fnm, time_t mtime, time_t atime, int frc) 703 #else 704 void 705 set_ftime(fnm, mtime, atime, frc) 706 char *fnm; 707 time_t mtime; 708 time_t atime; 709 int frc; 710 #endif 711 { 712 static struct timeval tv[2] = {{0L, 0L}, {0L, 0L}}; 713 struct stat sb; 714 715 tv[0].tv_sec = (long)atime; 716 tv[1].tv_sec = (long)mtime; 717 if (!frc && (!patime || !pmtime)) { 718 /* 719 * if we are not forcing, only set those times the user wants 720 * set. We get the current values of the times if we need them. 721 */ 722 if (lstat(fnm, &sb) == 0) { 723 if (!patime) 724 tv[0].tv_sec = (long)sb.st_atime; 725 if (!pmtime) 726 tv[1].tv_sec = (long)sb.st_mtime; 727 } else 728 syswarn(0,errno,"Unable to obtain file stats %s", fnm); 729 } 730 731 /* 732 * set the times 733 */ 734 if (utimes(fnm, tv) < 0) 735 syswarn(1, errno, "Access/modification time set failed on: %s", 736 fnm); 737 return; 738 } 739 740 /* 741 * set_ids() 742 * set the uid and gid of a file system node 743 * Return: 744 * 0 when set, -1 on failure 745 */ 746 747 #ifdef __STDC__ 748 int 749 set_ids(char *fnm, uid_t uid, gid_t gid) 750 #else 751 int 752 set_ids(fnm, uid, gid) 753 char *fnm; 754 uid_t uid; 755 gid_t gid; 756 #endif 757 { 758 if (chown(fnm, uid, gid) < 0) { 759 /* 760 * ignore EPERM unless in verbose mode or being run by root. 761 * if running as pax, POSIX requires a warning. 762 */ 763 if (strcmp(NM_PAX, argv0) == 0 || errno != EPERM || vflag || 764 geteuid() == 0) 765 syswarn(1, errno, "Unable to set file uid/gid of %s", 766 fnm); 767 return(-1); 768 } 769 return(0); 770 } 771 772 /* 773 * set_lids() 774 * set the uid and gid of a file system node 775 * Return: 776 * 0 when set, -1 on failure 777 */ 778 779 #ifdef __STDC__ 780 int 781 set_lids(char *fnm, uid_t uid, gid_t gid) 782 #else 783 int 784 set_lids(fnm, uid, gid) 785 char *fnm; 786 uid_t uid; 787 gid_t gid; 788 #endif 789 { 790 if (lchown(fnm, uid, gid) < 0) { 791 /* 792 * ignore EPERM unless in verbose mode or being run by root. 793 * if running as pax, POSIX requires a warning. 794 */ 795 if (strcmp(NM_PAX, argv0) == 0 || errno != EPERM || vflag || 796 geteuid() == 0) 797 syswarn(1, errno, "Unable to set file uid/gid of %s", 798 fnm); 799 return(-1); 800 } 801 return(0); 802 } 803 804 /* 805 * set_pmode() 806 * Set file access mode 807 */ 808 809 #ifdef __STDC__ 810 void 811 set_pmode(char *fnm, mode_t mode) 812 #else 813 void 814 set_pmode(fnm, mode) 815 char *fnm; 816 mode_t mode; 817 #endif 818 { 819 mode &= ABITS; 820 if (chmod(fnm, mode) < 0) 821 syswarn(1, errno, "Could not set permissions on %s", fnm); 822 return; 823 } 824 825 /* 826 * file_write() 827 * Write/copy a file (during copy or archive extract). This routine knows 828 * how to copy files with lseek holes in it. (Which are read as file 829 * blocks containing all 0's but do not have any file blocks associated 830 * with the data). Typical examples of these are files created by dbm 831 * variants (.pag files). While the file size of these files are huge, the 832 * actual storage is quite small (the files are sparse). The problem is 833 * the holes read as all zeros so are probably stored on the archive that 834 * way (there is no way to determine if the file block is really a hole, 835 * we only know that a file block of all zero's can be a hole). 836 * At this writing, no major archive format knows how to archive files 837 * with holes. However, on extraction (or during copy, -rw) we have to 838 * deal with these files. Without detecting the holes, the files can 839 * consume a lot of file space if just written to disk. This replacement 840 * for write when passed the basic allocation size of a file system block, 841 * uses lseek whenever it detects the input data is all 0 within that 842 * file block. In more detail, the strategy is as follows: 843 * While the input is all zero keep doing an lseek. Keep track of when we 844 * pass over file block boundries. Only write when we hit a non zero 845 * input. once we have written a file block, we continue to write it to 846 * the end (we stop looking at the input). When we reach the start of the 847 * next file block, start checking for zero blocks again. Working on file 848 * block boundries significantly reduces the overhead when copying files 849 * that are NOT very sparse. This overhead (when compared to a write) is 850 * almost below the measurement resolution on many systems. Without it, 851 * files with holes cannot be safely copied. It does has a side effect as 852 * it can put holes into files that did not have them before, but that is 853 * not a problem since the file contents are unchanged (in fact it saves 854 * file space). (Except on paging files for diskless clients. But since we 855 * cannot determine one of those file from here, we ignore them). If this 856 * ever ends up on a system where CTG files are supported and the holes 857 * are not desired, just do a conditional test in those routines that 858 * call file_write() and have it call write() instead. BEFORE CLOSING THE 859 * FILE, make sure to call file_flush() when the last write finishes with 860 * an empty block. A lot of file systems will not create an lseek hole at 861 * the end. In this case we drop a single 0 at the end to force the 862 * trailing 0's in the file. 863 * ---Parameters--- 864 * rem: how many bytes left in this file system block 865 * isempt: have we written to the file block yet (is it empty) 866 * sz: basic file block allocation size 867 * cnt: number of bytes on this write 868 * str: buffer to write 869 * Return: 870 * number of bytes written, -1 on write (or lseek) error. 871 */ 872 873 #ifdef __STDC__ 874 int 875 file_write(int fd, char *str, register int cnt, int *rem, int *isempt, int sz, 876 char *name) 877 #else 878 int 879 file_write(fd, str, cnt, rem, isempt, sz, name) 880 int fd; 881 char *str; 882 register int cnt; 883 int *rem; 884 int *isempt; 885 int sz; 886 char *name; 887 #endif 888 { 889 register char *pt; 890 register char *end; 891 register int wcnt; 892 register char *st = str; 893 894 /* 895 * while we have data to process 896 */ 897 while (cnt) { 898 if (!*rem) { 899 /* 900 * We are now at the start of file system block again 901 * (or what we think one is...). start looking for 902 * empty blocks again 903 */ 904 *isempt = 1; 905 *rem = sz; 906 } 907 908 /* 909 * only examine up to the end of the current file block or 910 * remaining characters to write, whatever is smaller 911 */ 912 wcnt = MIN(cnt, *rem); 913 cnt -= wcnt; 914 *rem -= wcnt; 915 if (*isempt) { 916 /* 917 * have not written to this block yet, so we keep 918 * looking for zero's 919 */ 920 pt = st; 921 end = st + wcnt; 922 923 /* 924 * look for a zero filled buffer 925 */ 926 while ((pt < end) && (*pt == '\0')) 927 ++pt; 928 929 if (pt == end) { 930 /* 931 * skip, buf is empty so far 932 */ 933 if (lseek(fd, (off_t)wcnt, SEEK_CUR) < 0) { 934 syswarn(1,errno,"File seek on %s", 935 name); 936 return(-1); 937 } 938 st = pt; 939 continue; 940 } 941 /* 942 * drat, the buf is not zero filled 943 */ 944 *isempt = 0; 945 } 946 947 /* 948 * have non-zero data in this file system block, have to write 949 */ 950 if (write(fd, st, wcnt) != wcnt) { 951 syswarn(1, errno, "Failed write to file %s", name); 952 return(-1); 953 } 954 st += wcnt; 955 } 956 return(st - str); 957 } 958 959 /* 960 * file_flush() 961 * when the last file block in a file is zero, many file systems will not 962 * let us create a hole at the end. To get the last block with zeros, we 963 * write the last BYTE with a zero (back up one byte and write a zero). 964 */ 965 966 #ifdef __STDC__ 967 void 968 file_flush(int fd, char *fname, int isempt) 969 #else 970 void 971 file_flush(fd, fname, isempt) 972 int fd; 973 char *fname; 974 int isempt; 975 #endif 976 { 977 static char blnk[] = "\0"; 978 979 /* 980 * silly test, but make sure we are only called when the last block is 981 * filled with all zeros. 982 */ 983 if (!isempt) 984 return; 985 986 /* 987 * move back one byte and write a zero 988 */ 989 if (lseek(fd, (off_t)-1, SEEK_CUR) < 0) { 990 syswarn(1, errno, "Failed seek on file %s", fname); 991 return; 992 } 993 994 if (write(fd, blnk, 1) < 0) 995 syswarn(1, errno, "Failed write to file %s", fname); 996 return; 997 } 998 999 /* 1000 * rdfile_close() 1001 * close a file we have beed reading (to copy or archive). If we have to 1002 * reset access time (tflag) do so (the times are stored in arcn). 1003 */ 1004 1005 #ifdef __STDC__ 1006 void 1007 rdfile_close(register ARCHD *arcn, register int *fd) 1008 #else 1009 void 1010 rdfile_close(arcn, fd) 1011 register ARCHD *arcn; 1012 register int *fd; 1013 #endif 1014 { 1015 /* 1016 * make sure the file is open 1017 */ 1018 if (*fd < 0) 1019 return; 1020 1021 (void)close(*fd); 1022 *fd = -1; 1023 if (!tflag) 1024 return; 1025 1026 /* 1027 * user wants last access time reset 1028 */ 1029 set_ftime(arcn->org_name, arcn->sb.st_mtime, arcn->sb.st_atime, 1); 1030 return; 1031 } 1032 1033 /* 1034 * set_crc() 1035 * read a file to calculate its crc. This is a real drag. Archive formats 1036 * that have this, end up reading the file twice (we have to write the 1037 * header WITH the crc before writing the file contents. Oh well... 1038 * Return: 1039 * 0 if was able to calculate the crc, -1 otherwise 1040 */ 1041 1042 #ifdef __STDC__ 1043 int 1044 set_crc(register ARCHD *arcn, register int fd) 1045 #else 1046 int 1047 set_crc(arcn, fd) 1048 register ARCHD *arcn; 1049 register int fd; 1050 #endif 1051 { 1052 register int i; 1053 register int res; 1054 off_t cpcnt = 0L; 1055 u_long size; 1056 unsigned long crc = 0L; 1057 char tbuf[FILEBLK]; 1058 struct stat sb; 1059 1060 if (fd < 0) { 1061 /* 1062 * hmm, no fd, should never happen. well no crc then. 1063 */ 1064 arcn->crc = 0L; 1065 return(0); 1066 } 1067 1068 if ((size = (u_long)arcn->sb.st_blksize) > (u_long)sizeof(tbuf)) 1069 size = (u_long)sizeof(tbuf); 1070 1071 /* 1072 * read all the bytes we think that there are in the file. If the user 1073 * is trying to archive an active file, forget this file. 1074 */ 1075 for(;;) { 1076 if ((res = read(fd, tbuf, size)) <= 0) 1077 break; 1078 cpcnt += res; 1079 for (i = 0; i < res; ++i) 1080 crc += (tbuf[i] & 0xff); 1081 } 1082 1083 /* 1084 * safety check. we want to avoid archiving files that are active as 1085 * they can create inconsistant archive copies. 1086 */ 1087 if (cpcnt != arcn->sb.st_size) 1088 paxwarn(1, "File changed size %s", arcn->org_name); 1089 else if (fstat(fd, &sb) < 0) 1090 syswarn(1, errno, "Failed stat on %s", arcn->org_name); 1091 else if (arcn->sb.st_mtime != sb.st_mtime) 1092 paxwarn(1, "File %s was modified during read", arcn->org_name); 1093 else if (lseek(fd, (off_t)0L, SEEK_SET) < 0) 1094 syswarn(1, errno, "File rewind failed on: %s", arcn->org_name); 1095 else { 1096 arcn->crc = crc; 1097 return(0); 1098 } 1099 return(-1); 1100 } 1101