file_subs.c revision 1557
1195333Simp/*- 2195333Simp * Copyright (c) 1992 Keith Muller. 3195333Simp * Copyright (c) 1992, 1993 4195333Simp * The Regents of the University of California. All rights reserved. 5195333Simp * 6195333Simp * This code is derived from software contributed to Berkeley by 7195333Simp * Keith Muller of the University of California, San Diego. 8195333Simp * 9195333Simp * Redistribution and use in source and binary forms, with or without 10195333Simp * modification, are permitted provided that the following conditions 11195333Simp * are met: 12195333Simp * 1. Redistributions of source code must retain the above copyright 13195333Simp * notice, this list of conditions and the following disclaimer. 14195333Simp * 2. Redistributions in binary form must reproduce the above copyright 15195333Simp * notice, this list of conditions and the following disclaimer in the 16195333Simp * documentation and/or other materials provided with the distribution. 17195333Simp * 3. All advertising materials mentioning features or use of this software 18195333Simp * must display the following acknowledgement: 19195333Simp * This product includes software developed by the University of 20195333Simp * California, Berkeley and its contributors. 21195333Simp * 4. Neither the name of the University nor the names of its contributors 22195333Simp * may be used to endorse or promote products derived from this software 23195333Simp * without specific prior written permission. 24195333Simp * 25195333Simp * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26195333Simp * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27195333Simp * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28195333Simp * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29195333Simp * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30195333Simp * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31195333Simp * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32195333Simp * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33195333Simp * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34195333Simp * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35195333Simp * SUCH DAMAGE. 36195333Simp */ 37195333Simp 38195333Simp#ifndef lint 39195333Simpstatic char sccsid[] = "@(#)file_subs.c 8.1 (Berkeley) 5/31/93"; 40195333Simp#endif /* not lint */ 41195333Simp 42195333Simp#include <sys/types.h> 43195333Simp#include <sys/time.h> 44195333Simp#include <sys/stat.h> 45195333Simp#include <unistd.h> 46195333Simp#include <sys/param.h> 47195333Simp#include <fcntl.h> 48195333Simp#include <string.h> 49195333Simp#include <stdio.h> 50195333Simp#include <ctype.h> 51195333Simp#include <errno.h> 52195333Simp#include <sys/uio.h> 53195333Simp#include <stdlib.h> 54195333Simp#include "pax.h" 55195333Simp#include "extern.h" 56195333Simp 57195333Simpstatic int 58195333Simpmk_link __P((register char *,register struct stat *,register char *, int)); 59195333Simp 60195333Simp/* 61195333Simp * routines that deal with file operations such as: creating, removing; 62195333Simp * and setting access modes, uid/gid and times of files 63195333Simp */ 64195333Simp 65195333Simp#define FILEBITS (S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO) 66195333Simp#define SETBITS (S_ISUID | S_ISGID) 67195333Simp#define ABITS (FILEBITS | SETBITS) 68195333Simp 69195333Simp/* 70195333Simp * file_creat() 71195333Simp * Create and open a file. 72195333Simp * Return: 73195333Simp * file descriptor or -1 for failure 74195333Simp */ 75195333Simp 76195333Simp#if __STDC__ 77195333Simpint 78195333Simpfile_creat(register ARCHD *arcn) 79195333Simp#else 80195333Simpint 81195333Simpfile_creat(arcn) 82195333Simp register ARCHD *arcn; 83195333Simp#endif 84195333Simp{ 85195333Simp int fd = -1; 86195333Simp mode_t file_mode; 87195333Simp int oerrno; 88195333Simp 89195333Simp /* 90195333Simp * assume file doesn't exist, so just try to create it, most times this 91195333Simp * works. We have to take special handling when the file does exist. To 92195333Simp * detect this, we use O_EXCL. For example when trying to create a 93195333Simp * file and a character device or fifo exists with the same name, we 94195333Simp * can accidently open the device by mistake (or block waiting to open) 95195333Simp * If we find that the open has failed, then figure spend the effore to 96203000Sneel * figure out why. This strategy was found to have better average 97203000Sneel * performance in common use than checking the file (and the path) 98198669Srrs * first with lstat. 99198669Srrs */ 100198669Srrs file_mode = arcn->sb.st_mode & FILEBITS; 101198669Srrs if ((fd = open(arcn->name, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 102198669Srrs file_mode)) >= 0) 103198669Srrs return(fd); 104195333Simp 105195333Simp /* 106195333Simp * the file seems to exist. First we try to get rid of it (found to be 107195333Simp * the second most common failure when traced). If this fails, only 108195333Simp * then we go to the expense to check and create the path to the file 109195333Simp */ 110195333Simp if (unlnk_exist(arcn->name, arcn->type) != 0) 111195333Simp return(-1); 112195333Simp 113195333Simp for (;;) { 114195333Simp /* 115195333Simp * try to open it again, if this fails, check all the nodes in 116195333Simp * the path and give it a final try. if chk_path() finds that 117195333Simp * it cannot fix anything, we will skip the last attempt 118195333Simp */ 119195333Simp if ((fd = open(arcn->name, O_WRONLY | O_CREAT | O_TRUNC, 120195333Simp file_mode)) >= 0) 121195333Simp break; 122195333Simp oerrno = errno; 123195333Simp if (chk_path(arcn->name,arcn->sb.st_uid,arcn->sb.st_gid) < 0) { 124195333Simp syswarn(1, oerrno, "Unable to create %s", arcn->name); 125195333Simp return(-1); 126195333Simp } 127195333Simp } 128195333Simp return(fd); 129195333Simp} 130195333Simp 131195333Simp/* 132195333Simp * file_close() 133195333Simp * Close file descriptor to a file just created by pax. Sets modes, 134195333Simp * ownership and times as required. 135195333Simp * Return: 136195333Simp * 0 for success, -1 for failure 137195333Simp */ 138195333Simp 139195333Simp#if __STDC__ 140195333Simpvoid 141195333Simpfile_close(register ARCHD *arcn, int fd) 142195333Simp#else 143195333Simpvoid 144195333Simpfile_close(arcn, fd) 145195333Simp register ARCHD *arcn; 146195333Simp int fd; 147195333Simp#endif 148195333Simp{ 149195333Simp int res = 0; 150195333Simp 151195333Simp if (fd < 0) 152195333Simp return; 153195333Simp if (close(fd) < 0) 154195333Simp syswarn(0, errno, "Unable to close file descriptor on %s", 155195333Simp arcn->name); 156195333Simp 157195333Simp /* 158195333Simp * set owner/groups first as this may strip off mode bits we want 159195333Simp * then set file permission modes. Then set file access and 160195333Simp * modification times. 161195333Simp */ 162195333Simp if (pids) 163195333Simp res = set_ids(arcn->name, arcn->sb.st_uid, arcn->sb.st_gid); 164195333Simp 165195333Simp /* 166195333Simp * IMPORTANT SECURITY NOTE: 167195333Simp * if not preserving mode or we cannot set uid/gid, then PROHIBIT 168195333Simp * set uid/gid bits 169195333Simp */ 170195333Simp if (!pmode || res) 171195333Simp arcn->sb.st_mode &= ~(SETBITS); 172195333Simp if (pmode) 173195333Simp set_pmode(arcn->name, arcn->sb.st_mode); 174202954Sgonzo if (patime || pmtime) 175195333Simp set_ftime(arcn->name, arcn->sb.st_mtime, arcn->sb.st_atime, 0); 176195333Simp} 177195333Simp 178195333Simp/* 179195333Simp * lnk_creat() 180195333Simp * Create a hard link to arcn->ln_name from arcn->name. arcn->ln_name 181195333Simp * must exist; 182195333Simp * Return: 183195333Simp * 0 if ok, -1 otherwise 184195333Simp */ 185195333Simp 186195333Simp#if __STDC__ 187195333Simpint 188203000Sneellnk_creat(register ARCHD *arcn) 189203000Sneel#else 190203000Sneelint 191203000Sneellnk_creat(arcn) 192203000Sneel register ARCHD *arcn; 193203000Sneel#endif 194203000Sneel{ 195203000Sneel struct stat sb; 196203000Sneel 197203000Sneel /* 198203000Sneel * we may be running as root, so we have to be sure that link target 199203000Sneel * is not a directory, so we lstat and check 200203000Sneel */ 201203000Sneel if (lstat(arcn->ln_name, &sb) < 0) { 202203000Sneel syswarn(1,errno,"Unable to link to %s from %s", arcn->ln_name, 203203000Sneel arcn->name); 204203000Sneel return(-1); 205203000Sneel } 206203000Sneel 207203000Sneel if (S_ISDIR(sb.st_mode)) { 208203000Sneel warn(1, "A hard link to the directory %s is not allowed", 209203000Sneel arcn->ln_name); 210195333Simp return(-1); 211195333Simp } 212195333Simp 213195333Simp return(mk_link(arcn->ln_name, &sb, arcn->name, 0)); 214195333Simp} 215195333Simp 216195333Simp/* 217195333Simp * cross_lnk() 218195333Simp * Create a hard link to arcn->org_name from arcn->name. Only used in copy 219195333Simp * with the -l flag. No warning or error if this does not succeed (we will 220195333Simp * then just create the file) 221195333Simp * Return: 222195333Simp * 1 if copy() should try to create this file node 223195333Simp * 0 if cross_lnk() ok, -1 for fatal flaw (like linking to self). 224195333Simp */ 225195333Simp 226195333Simp#if __STDC__ 227195333Simpint 228195333Simpcross_lnk(register ARCHD *arcn) 229195333Simp#else 230195333Simpint 231195333Simpcross_lnk(arcn) 232195333Simp register ARCHD *arcn; 233195333Simp#endif 234195333Simp{ 235195333Simp /* 236195333Simp * try to make a link to orginal file (-l flag in copy mode). make sure 237195333Simp * we do not try to link to directories in case we are running as root 238195333Simp * (and it might succeed). 239195333Simp */ 240195333Simp if (arcn->type == PAX_DIR) 241195333Simp return(1); 242195333Simp return(mk_link(arcn->org_name, &(arcn->sb), arcn->name, 1)); 243195333Simp} 244195333Simp 245195333Simp/* 246195333Simp * chk_same() 247195333Simp * In copy mode if we are not trying to make hard links between the src 248195333Simp * and destinations, make sure we are not going to overwrite ourselves by 249195333Simp * accident. This slows things down a little, but we have to protect all 250195333Simp * those people who make typing errors. 251195333Simp * Return: 252195333Simp * 1 the target does not exist, go ahead and copy 253195333Simp * 0 skip it file exists (-k) or may be the same as source file 254195333Simp */ 255195333Simp 256195333Simp#if __STDC__ 257202864Sneelint 258202864Sneelchk_same(register ARCHD *arcn) 259202864Sneel#else 260202864Sneelint 261202864Sneelchk_same(arcn) 262202864Sneel register ARCHD *arcn; 263202864Sneel#endif 264202864Sneel{ 265202864Sneel struct stat sb; 266202864Sneel 267202864Sneel /* 268202864Sneel * if file does not exist, return. if file exists and -k, skip it 269195333Simp * quietly 270201631Sneel */ 271201631Sneel if (lstat(arcn->name, &sb) < 0) 272195333Simp return(1); 273202864Sneel if (kflag) 274202864Sneel return(0); 275202864Sneel 276202864Sneel /* 277202864Sneel * better make sure the user does not have src == dest by mistake 278195333Simp */ 279195333Simp if ((arcn->sb.st_dev == sb.st_dev) && (arcn->sb.st_ino == sb.st_ino)) { 280202954Sgonzo warn(1, "Unable to copy %s, file would overwrite itself", 281195333Simp arcn->name); 282201845Simp return(0); 283201881Simp } 284201845Simp return(1); 285195333Simp} 286195333Simp 287195333Simp/* 288195333Simp * mk_link() 289201631Sneel * try to make a hard link between two files. if ign set, we do not 290201631Sneel * complain. 291201631Sneel * Return: 292201631Sneel * 0 if successful (or we are done with this file but no error, such as 293201631Sneel * finding the from file exists and the user has set -k). 294195333Simp * 1 when ign was set to indicates we could not make the link but we 295201631Sneel * should try to copy/extract the file as that might work (and is an 296201631Sneel * allowed option). -1 an error occurred. 297195333Simp */ 298195333Simp 299195333Simp#if __STDC__ 300195333Simpstatic int 301195333Simpmk_link(register char *to, register struct stat *to_sb, register char *from, 302195333Simp int ign) 303195333Simp#else 304static int 305mk_link(to, to_sb, from, ign) 306 register char *to; 307 register struct stat *to_sb; 308 register char *from; 309 int ign; 310#endif 311{ 312 struct stat sb; 313 int oerrno; 314 315 /* 316 * if from file exists, it has to be unlinked to make the link. If the 317 * file exists and -k is set, skip it quietly 318 */ 319 if (lstat(from, &sb) == 0) { 320 if (kflag) 321 return(0); 322 323 /* 324 * make sure it is not the same file, protect the user 325 */ 326 if ((to_sb->st_dev==sb.st_dev)&&(to_sb->st_ino == sb.st_ino)) { 327 warn(1, "Unable to link file %s to itself", to); 328 return(-1);; 329 } 330 331 /* 332 * try to get rid of the file, based on the type 333 */ 334 if (S_ISDIR(sb.st_mode)) { 335 if (rmdir(from) < 0) { 336 syswarn(1, errno, "Unable to remove %s", from); 337 return(-1); 338 } 339 } else if (unlink(from) < 0) { 340 if (!ign) { 341 syswarn(1, errno, "Unable to remove %s", from); 342 return(-1); 343 } 344 return(1); 345 } 346 } 347 348 /* 349 * from file is gone (or did not exist), try to make the hard link. 350 * if it fails, check the path and try it again (if chk_path() says to 351 * try again) 352 */ 353 for (;;) { 354 if (link(to, from) == 0) 355 break; 356 oerrno = errno; 357 if (chk_path(from, to_sb->st_uid, to_sb->st_gid) == 0) 358 continue; 359 if (!ign) { 360 syswarn(1, oerrno, "Could not link to %s from %s", to, 361 from); 362 return(-1); 363 } 364 return(1); 365 } 366 367 /* 368 * all right the link was made 369 */ 370 return(0); 371} 372 373/* 374 * node_creat() 375 * create an entry in the file system (other than a file or hard link). 376 * If successful, sets uid/gid modes and times as required. 377 * Return: 378 * 0 if ok, -1 otherwise 379 */ 380 381#if __STDC__ 382int 383node_creat(register ARCHD *arcn) 384#else 385int 386node_creat(arcn) 387 register ARCHD *arcn; 388#endif 389{ 390 register int res; 391 register int ign = 0; 392 register int oerrno; 393 register int pass = 0; 394 mode_t file_mode; 395 struct stat sb; 396 397 /* 398 * create node based on type, if that fails try to unlink the node and 399 * try again. finally check the path and try again. As noted in the 400 * file and link creation routines, this method seems to exhibit the 401 * best performance in general use workloads. 402 */ 403 file_mode = arcn->sb.st_mode & FILEBITS; 404 405 for (;;) { 406 switch(arcn->type) { 407 case PAX_DIR: 408 res = mkdir(arcn->name, file_mode); 409 if (ign) 410 res = 0; 411 break; 412 case PAX_CHR: 413 file_mode |= S_IFCHR; 414 res = mknod(arcn->name, file_mode, arcn->sb.st_rdev); 415 break; 416 case PAX_BLK: 417 file_mode |= S_IFBLK; 418 res = mknod(arcn->name, file_mode, arcn->sb.st_rdev); 419 break; 420 case PAX_FIF: 421 res = mkfifo(arcn->name, file_mode); 422 break; 423 case PAX_SCK: 424 /* 425 * Skip sockets, operation has no meaning under BSD 426 */ 427 warn(0, 428 "%s skipped. Sockets cannot be copied or extracted", 429 arcn->name); 430 return(-1); 431 case PAX_SLK: 432 if ((res = symlink(arcn->ln_name, arcn->name)) == 0) 433 return(0); 434 break; 435 case PAX_CTG: 436 case PAX_HLK: 437 case PAX_HRG: 438 case PAX_REG: 439 default: 440 /* 441 * we should never get here 442 */ 443 warn(0, "%s has an unknown file type, skipping", 444 arcn->name); 445 return(-1); 446 } 447 448 /* 449 * if we were able to create the node break out of the loop, 450 * otherwise try to unlink the node and try again. if that 451 * fails check the full path and try a final time. 452 */ 453 if (res == 0) 454 break; 455 456 /* 457 * we failed to make the node 458 */ 459 oerrno = errno; 460 if ((ign = unlnk_exist(arcn->name, arcn->type)) < 0) 461 return(-1); 462 463 if (++pass <= 1) 464 continue; 465 466 if (chk_path(arcn->name,arcn->sb.st_uid,arcn->sb.st_gid) < 0) { 467 syswarn(1, oerrno, "Could not create: %s", arcn->name); 468 return(-1); 469 } 470 } 471 472 /* 473 * we were able to create the node. set uid/gid, modes and times 474 */ 475 if (pids) 476 res = set_ids(arcn->name, arcn->sb.st_uid, arcn->sb.st_gid); 477 else 478 res = 0; 479 480 /* 481 * IMPORTANT SECURITY NOTE: 482 * if not preserving mode or we cannot set uid/gid, then PROHIBIT any 483 * set uid/gid bits 484 */ 485 if (!pmode || res) 486 arcn->sb.st_mode &= ~(SETBITS); 487 if (pmode) 488 set_pmode(arcn->name, arcn->sb.st_mode); 489 490 if (arcn->type == PAX_DIR) { 491 /* 492 * Dirs must be processed again at end of extract to set times 493 * and modes to agree with those stored in the archive. However 494 * to allow extract to continue, we may have to also set owner 495 * rights. This allows nodes in the archive that are children 496 * of this directory to be extracted without failure. Both time 497 * and modes will be fixed after the entire archive is read and 498 * before pax exits. 499 */ 500 if (access(arcn->name, R_OK | W_OK | X_OK) < 0) { 501 if (lstat(arcn->name, &sb) < 0) { 502 syswarn(0, errno,"Could not access %s (stat)", 503 arcn->name); 504 set_pmode(arcn->name,file_mode | S_IRWXU); 505 } else { 506 /* 507 * We have to add rights to the dir, so we make 508 * sure to restore the mode. The mode must be 509 * restored AS CREATED and not as stored if 510 * pmode is not set. 511 */ 512 set_pmode(arcn->name, 513 ((sb.st_mode & FILEBITS) | S_IRWXU)); 514 if (!pmode) 515 arcn->sb.st_mode = sb.st_mode; 516 } 517 518 /* 519 * we have to force the mode to what was set here, 520 * since we changed it from the default as created. 521 */ 522 add_dir(arcn->name, arcn->nlen, &(arcn->sb), 1); 523 } else if (pmode || patime || pmtime) 524 add_dir(arcn->name, arcn->nlen, &(arcn->sb), 0); 525 } 526 527 if (patime || pmtime) 528 set_ftime(arcn->name, arcn->sb.st_mtime, arcn->sb.st_atime, 0); 529 return(0); 530} 531 532/* 533 * unlnk_exist() 534 * Remove node from file system with the specified name. We pass the type 535 * of the node that is going to replace it. When we try to create a 536 * directory and find that it already exists, we allow processing to 537 * continue as proper modes etc will always be set for it later on. 538 * Return: 539 * 0 is ok to proceed, no file with the specified name exists 540 * -1 we were unable to remove the node, or we should not remove it (-k) 541 * 1 we found a directory and we were going to create a directory. 542 */ 543 544#if __STDC__ 545int 546unlnk_exist(register char *name, register int type) 547#else 548int 549unlnk_exist(name, type) 550 register char *name; 551 register int type; 552#endif 553{ 554 struct stat sb; 555 556 /* 557 * the file does not exist, or -k we are done 558 */ 559 if (lstat(name, &sb) < 0) 560 return(0); 561 if (kflag) 562 return(-1); 563 564 if (S_ISDIR(sb.st_mode)) { 565 /* 566 * try to remove a directory, if it fails and we were going to 567 * create a directory anyway, tell the caller (return a 1) 568 */ 569 if (rmdir(name) < 0) { 570 if (type == PAX_DIR) 571 return(1); 572 syswarn(1,errno,"Unable to remove directory %s", name); 573 return(-1); 574 } 575 return(0); 576 } 577 578 /* 579 * try to get rid of all non-directory type nodes 580 */ 581 if (unlink(name) < 0) { 582 syswarn(1, errno, "Could not unlink %s", name); 583 return(-1); 584 } 585 return(0); 586} 587 588/* 589 * chk_path() 590 * We were trying to create some kind of node in the file system and it 591 * failed. chk_path() makes sure the path up to the node exists and is 592 * writeable. When we have to create a directory that is missing along the 593 * path somewhere, the directory we create will be set to the same 594 * uid/gid as the file has (when uid and gid are being preserved). 595 * NOTE: this routine is a real performance loss. It is only used as a 596 * last resort when trying to create entries in the file system. 597 * Return: 598 * -1 when it could find nothing it is allowed to fix. 599 * 0 otherwise 600 */ 601 602#if __STDC__ 603int 604chk_path( register char *name, uid_t st_uid, gid_t st_gid) 605#else 606int 607chk_path(name, st_uid, st_gid) 608 register char *name; 609 uid_t st_uid; 610 gid_t st_gid; 611#endif 612{ 613 register char *spt = name; 614 struct stat sb; 615 int retval = -1; 616 617 /* 618 * watch out for paths with nodes stored directly in / (e.g. /bozo) 619 */ 620 if (*spt == '/') 621 ++spt; 622 623 for(;;) { 624 /* 625 * work foward from the first / and check each part of the path 626 */ 627 spt = strchr(spt, '/'); 628 if (spt == NULL) 629 break; 630 *spt = '\0'; 631 632 /* 633 * if it exists we assume it is a directory, it is not within 634 * the spec (at least it seems to read that way) to alter the 635 * file system for nodes NOT EXPLICITLY stored on the archive. 636 * If that assumption is changed, you would test the node here 637 * and figure out how to get rid of it (probably like some 638 * recursive unlink()) or fix up the directory permissions if 639 * required (do an access()). 640 */ 641 if (lstat(name, &sb) == 0) { 642 *(spt++) = '/'; 643 continue; 644 } 645 646 /* 647 * the path fails at this point, see if we can create the 648 * needed directory and continue on 649 */ 650 if (mkdir(name, S_IRWXU | S_IRWXG | S_IRWXO) < 0) { 651 *spt = '/'; 652 retval = -1; 653 break; 654 } 655 656 /* 657 * we were able to create the directory. We will tell the 658 * caller that we found something to fix, and it is ok to try 659 * and create the node again. 660 */ 661 retval = 0; 662 if (pids) 663 (void)set_ids(name, st_uid, st_gid); 664 665 /* 666 * make sure the user doen't have some strange umask that 667 * causes this newly created directory to be unusable. We fix 668 * the modes and restore them back to the creation default at 669 * the end of pax 670 */ 671 if ((access(name, R_OK | W_OK | X_OK) < 0) && 672 (lstat(name, &sb) == 0)) { 673 set_pmode(name, ((sb.st_mode & FILEBITS) | S_IRWXU)); 674 add_dir(name, spt - name, &sb, 1); 675 } 676 *(spt++) = '/'; 677 continue; 678 } 679 return(retval); 680} 681 682/* 683 * set_ftime() 684 * Set the access time and modification time for a named file. If frc is 685 * non-zero we force these times to be set even if the the user did not 686 * request access and/or modification time preservation (this is also 687 * used by -t to reset access times). 688 * When ign is zero, only those times the user has asked for are set, the 689 * other ones are left alone. We do not assume the un-documented feature 690 * of many utimes() implementations that consider a 0 time value as a do 691 * not set request. 692 */ 693 694#if __STDC__ 695void 696set_ftime(char *fnm, time_t mtime, time_t atime, int frc) 697#else 698void 699set_ftime(fnm, mtime, atime, frc) 700 char *fnm; 701 time_t mtime; 702 time_t atime; 703 int frc; 704#endif 705{ 706 static struct timeval tv[2] = {{0L, 0L}, {0L, 0L}}; 707 struct stat sb; 708 709 tv[0].tv_sec = (long)atime; 710 tv[1].tv_sec = (long)mtime; 711 if (!frc && (!patime || !pmtime)) { 712 /* 713 * if we are not forcing, only set those times the user wants 714 * set. We get the current values of the times if we need them. 715 */ 716 if (lstat(fnm, &sb) == 0) { 717 if (!patime) 718 tv[0].tv_sec = (long)sb.st_atime; 719 if (!pmtime) 720 tv[1].tv_sec = (long)sb.st_mtime; 721 } else 722 syswarn(0,errno,"Unable to obtain file stats %s", fnm); 723 } 724 725 /* 726 * set the times 727 */ 728 if (utimes(fnm, tv) < 0) 729 syswarn(1, errno, "Access/modification time set failed on: %s", 730 fnm); 731 return; 732} 733 734/* 735 * set_ids() 736 * set the uid and gid of a file system node 737 * Return: 738 * 0 when set, -1 on failure 739 */ 740 741#if __STDC__ 742int 743set_ids(char *fnm, uid_t uid, gid_t gid) 744#else 745int 746set_ids(fnm, uid, gid) 747 char *fnm; 748 uid_t uid; 749 gid_t gid; 750#endif 751{ 752 if (chown(fnm, uid, gid) < 0) { 753 syswarn(1, errno, "Unable to set file uid/gid of %s", fnm); 754 return(-1); 755 } 756 return(0); 757} 758 759/* 760 * set_pmode() 761 * Set file access mode 762 */ 763 764#if __STDC__ 765void 766set_pmode(char *fnm, mode_t mode) 767#else 768void 769set_pmode(fnm, mode) 770 char *fnm; 771 mode_t mode; 772#endif 773{ 774 mode &= ABITS; 775 if (chmod(fnm, mode) < 0) 776 syswarn(1, errno, "Could not set permissions on %s", fnm); 777 return; 778} 779 780/* 781 * file_write() 782 * Write/copy a file (during copy or archive extract). This routine knows 783 * how to copy files with lseek holes in it. (Which are read as file 784 * blocks containing all 0's but do not have any file blocks associated 785 * with the data). Typical examples of these are files created by dbm 786 * variants (.pag files). While the file size of these files are huge, the 787 * actual storage is quite small (the files are sparse). The problem is 788 * the holes read as all zeros so are probably stored on the archive that 789 * way (there is no way to determine if the file block is really a hole, 790 * we only know that a file block of all zero's can be a hole). 791 * At this writing, no major archive format knows how to archive files 792 * with holes. However, on extraction (or during copy, -rw) we have to 793 * deal with these files. Without detecting the holes, the files can 794 * consume a lot of file space if just written to disk. This replacement 795 * for write when passed the basic allocation size of a file system block, 796 * uses lseek whenever it detects the input data is all 0 within that 797 * file block. In more detail, the strategy is as follows: 798 * While the input is all zero keep doing an lseek. Keep track of when we 799 * pass over file block boundries. Only write when we hit a non zero 800 * input. once we have written a file block, we continue to write it to 801 * the end (we stop looking at the input). When we reach the start of the 802 * next file block, start checking for zero blocks again. Working on file 803 * block boundries significantly reduces the overhead when copying files 804 * that are NOT very sparse. This overhead (when compared to a write) is 805 * almost below the measurement resolution on many systems. Without it, 806 * files with holes cannot be safely copied. It does has a side effect as 807 * it can put holes into files that did not have them before, but that is 808 * not a problem since the file contents are unchanged (in fact it saves 809 * file space). (Except on paging files for diskless clients. But since we 810 * cannot determine one of those file from here, we ignore them). If this 811 * ever ends up on a system where CTG files are supported and the holes 812 * are not desired, just do a conditional test in those routines that 813 * call file_write() and have it call write() instead. BEFORE CLOSING THE 814 * FILE, make sure to call file_flush() when the last write finishes with 815 * an empty block. A lot of file systems will not create an lseek hole at 816 * the end. In this case we drop a single 0 at the end to force the 817 * trailing 0's in the file. 818 * ---Parameters--- 819 * rem: how many bytes left in this file system block 820 * isempt: have we written to the file block yet (is it empty) 821 * sz: basic file block allocation size 822 * cnt: number of bytes on this write 823 * str: buffer to write 824 * Return: 825 * number of bytes written, -1 on write (or lseek) error. 826 */ 827 828#if __STDC__ 829int 830file_write(int fd, char *str, register int cnt, int *rem, int *isempt, int sz, 831 char *name) 832#else 833int 834file_write(fd, str, cnt, rem, isempt, sz, name) 835 int fd; 836 char *str; 837 register int cnt; 838 int *rem; 839 int *isempt; 840 int sz; 841 char *name; 842#endif 843{ 844 register char *pt; 845 register char *end; 846 register int wcnt; 847 register char *st = str; 848 849 /* 850 * while we have data to process 851 */ 852 while (cnt) { 853 if (!*rem) { 854 /* 855 * We are now at the start of file system block again 856 * (or what we think one is...). start looking for 857 * empty blocks again 858 */ 859 *isempt = 1; 860 *rem = sz; 861 } 862 863 /* 864 * only examine up to the end of the current file block or 865 * remaining characters to write, whatever is smaller 866 */ 867 wcnt = MIN(cnt, *rem); 868 cnt -= wcnt; 869 *rem -= wcnt; 870 if (*isempt) { 871 /* 872 * have not written to this block yet, so we keep 873 * looking for zero's 874 */ 875 pt = st; 876 end = st + wcnt; 877 878 /* 879 * look for a zero filled buffer 880 */ 881 while ((pt < end) && (*pt == '\0')) 882 ++pt; 883 884 if (pt == end) { 885 /* 886 * skip, buf is empty so far 887 */ 888 if (lseek(fd, (off_t)wcnt, SEEK_CUR) < 0) { 889 syswarn(1,errno,"File seek on %s", 890 name); 891 return(-1); 892 } 893 st = pt; 894 continue; 895 } 896 /* 897 * drat, the buf is not zero filled 898 */ 899 *isempt = 0; 900 } 901 902 /* 903 * have non-zero data in this file system block, have to write 904 */ 905 if (write(fd, st, wcnt) != wcnt) { 906 syswarn(1, errno, "Failed write to file %s", name); 907 return(-1); 908 } 909 st += wcnt; 910 } 911 return(st - str); 912} 913 914/* 915 * file_flush() 916 * when the last file block in a file is zero, many file systems will not 917 * let us create a hole at the end. To get the last block with zeros, we 918 * write the last BYTE with a zero (back up one byte and write a zero). 919 */ 920 921#if __STDC__ 922void 923file_flush(int fd, char *fname, int isempt) 924#else 925void 926file_flush(fd, fname, isempt) 927 int fd; 928 char *fname; 929 int isempt; 930#endif 931{ 932 static char blnk[] = "\0"; 933 934 /* 935 * silly test, but make sure we are only called when the last block is 936 * filled with all zeros. 937 */ 938 if (!isempt) 939 return; 940 941 /* 942 * move back one byte and write a zero 943 */ 944 if (lseek(fd, (off_t)-1, SEEK_CUR) < 0) { 945 syswarn(1, errno, "Failed seek on file %s", fname); 946 return; 947 } 948 949 if (write(fd, blnk, 1) < 0) 950 syswarn(1, errno, "Failed write to file %s", fname); 951 return; 952} 953 954/* 955 * rdfile_close() 956 * close a file we have beed reading (to copy or archive). If we have to 957 * reset access time (tflag) do so (the times are stored in arcn). 958 */ 959 960#if __STDC__ 961void 962rdfile_close(register ARCHD *arcn, register int *fd) 963#else 964void 965rdfile_close(arcn, fd) 966 register ARCHD *arcn; 967 register int *fd; 968#endif 969{ 970 /* 971 * make sure the file is open 972 */ 973 if (*fd < 0) 974 return; 975 976 (void)close(*fd); 977 *fd = -1; 978 if (!tflag) 979 return; 980 981 /* 982 * user wants last access time reset 983 */ 984 set_ftime(arcn->org_name, arcn->sb.st_mtime, arcn->sb.st_atime, 1); 985 return; 986} 987 988/* 989 * set_crc() 990 * read a file to calculate its crc. This is a real drag. Archive formats 991 * that have this, end up reading the file twice (we have to write the 992 * header WITH the crc before writing the file contents. Oh well... 993 * Return: 994 * 0 if was able to calculate the crc, -1 otherwise 995 */ 996 997#if __STDC__ 998int 999set_crc(register ARCHD *arcn, register int fd) 1000#else 1001int 1002set_crc(arcn, fd) 1003 register ARCHD *arcn; 1004 register int fd; 1005#endif 1006{ 1007 register int i; 1008 register int res; 1009 off_t cpcnt = 0L; 1010 u_long size; 1011 unsigned long crc = 0L; 1012 char tbuf[FILEBLK]; 1013 struct stat sb; 1014 1015 if (fd < 0) { 1016 /* 1017 * hmm, no fd, should never happen. well no crc then. 1018 */ 1019 arcn->crc = 0L; 1020 return(0); 1021 } 1022 1023 if ((size = (u_long)arcn->sb.st_blksize) > (u_long)sizeof(tbuf)) 1024 size = (u_long)sizeof(tbuf); 1025 1026 /* 1027 * read all the bytes we think that there are in the file. If the user 1028 * is trying to archive an active file, forget this file. 1029 */ 1030 for(;;) { 1031 if ((res = read(fd, tbuf, size)) <= 0) 1032 break; 1033 cpcnt += res; 1034 for (i = 0; i < res; ++i) 1035 crc += (tbuf[i] & 0xff); 1036 } 1037 1038 /* 1039 * safety check. we want to avoid archiving files that are active as 1040 * they can create inconsistant archive copies. 1041 */ 1042 if (cpcnt != arcn->sb.st_size) 1043 warn(1, "File changed size %s", arcn->org_name); 1044 else if (fstat(fd, &sb) < 0) 1045 syswarn(1, errno, "Failed stat on %s", arcn->org_name); 1046 else if (arcn->sb.st_mtime != sb.st_mtime) 1047 warn(1, "File %s was modified during read", arcn->org_name); 1048 else if (lseek(fd, (off_t)0L, SEEK_SET) < 0) 1049 syswarn(1, errno, "File rewind failed on: %s", arcn->org_name); 1050 else { 1051 arcn->crc = crc; 1052 return(0); 1053 } 1054 return(-1); 1055} 1056