1/* $OpenBSD: ar_io.c,v 1.38 2008/06/11 00:49:08 pvalchev Exp $ */ 2/* $NetBSD: ar_io.c,v 1.5 1996/03/26 23:54:13 mrg 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[] = "@(#)ar_io.c 8.2 (Berkeley) 4/18/94"; 41#else 42__used static const char rcsid[] = "$OpenBSD: ar_io.c,v 1.38 2008/06/11 00:49:08 pvalchev Exp $"; 43#endif 44#endif /* not lint */ 45 46#include <sys/types.h> 47#include <sys/time.h> 48#include <sys/stat.h> 49#include <sys/ioctl.h> 50#ifndef __APPLE__ 51#include <sys/mtio.h> 52#endif /* !__APPLE__ */ 53#include <sys/param.h> 54#include <sys/wait.h> 55#include <signal.h> 56#include <string.h> 57#include <fcntl.h> 58#include <unistd.h> 59#include <stdio.h> 60#include <errno.h> 61#include <stdlib.h> 62#include <err.h> 63#include <stdint.h> 64#include "pax.h" 65#include "options.h" 66#include "extern.h" 67 68/* 69 * Routines which deal directly with the archive I/O device/file. 70 */ 71 72#define DMOD 0666 /* default mode of created archives */ 73#define EXT_MODE O_RDONLY /* open mode for list/extract */ 74#define AR_MODE (O_WRONLY | O_CREAT | O_TRUNC) /* mode for archive */ 75#define APP_MODE O_RDWR /* mode for append */ 76#define STDO "<STDOUT>" /* pseudo name for stdout */ 77#define STDN "<STDIN>" /* pseudo name for stdin */ 78#define _NONE "<NONE>" /* pseudo name for no files */ 79static int arfd = -1; /* archive file descriptor */ 80static int artyp = ISREG; /* archive type: file/FIFO/tape */ 81static int arvol = 1; /* archive volume number */ 82static int lstrval = -1; /* return value from last i/o */ 83static int io_ok; /* i/o worked on volume after resync */ 84static int did_io; /* did i/o ever occur on volume? */ 85static int done; /* set via tty termination */ 86static struct stat arsb; /* stat of archive device at open */ 87static int invld_rec; /* tape has out of spec record size */ 88static int wr_trail = 1; /* trailer was rewritten in append */ 89static int can_unlnk = 0; /* do we unlink null archives? */ 90const char *arcname; /* printable name of archive */ 91const char *gzip_program; /* name of gzip program */ 92static pid_t zpid = -1; /* pid of child process */ 93int force_one_volume; /* 1 if we ignore volume changes */ 94 95#ifndef __APPLE__ 96static int get_phys(void); 97#endif /* __APPLE__ */ 98extern sigset_t s_mask; 99static void ar_start_gzip(int, const char *, int); 100 101/* 102 * ar_open() 103 * Opens the next archive volume. Determines the type of the device and 104 * sets up block sizes as required by the archive device and the format. 105 * Note: we may be called with name == NULL on the first open only. 106 * Return: 107 * -1 on failure, 0 otherwise 108 */ 109 110int 111ar_open(const char *name) 112{ 113#ifndef __APPLE__ 114 struct mtget mb; 115#endif /* __APPLE__ */ 116 if (arfd != -1) 117 (void)close(arfd); 118 arfd = -1; 119 can_unlnk = did_io = io_ok = invld_rec = 0; 120 artyp = ISREG; 121 flcnt = 0; 122 123 /* 124 * open based on overall operation mode 125 */ 126 switch (act) { 127 case LIST: 128 case EXTRACT: 129 if (name == NULL) { 130 arfd = STDIN_FILENO; 131 arcname = STDN; 132 } else if ((arfd = open(name, EXT_MODE, DMOD)) < 0) 133 syswarn(1, errno, "Failed open to read on %s", name); 134 if (arfd != -1 && gzip_program != NULL) 135 ar_start_gzip(arfd, gzip_program, 0); 136 break; 137 case ARCHIVE: 138 if (name == NULL) { 139 arfd = STDOUT_FILENO; 140 arcname = STDO; 141 } else if ((arfd = open(name, AR_MODE, DMOD)) < 0) 142 syswarn(1, errno, "Failed open to write on %s", name); 143 else 144 can_unlnk = 1; 145 if (arfd != -1 && gzip_program != NULL) 146 ar_start_gzip(arfd, gzip_program, 1); 147 break; 148 case APPND: 149 if (name == NULL) { 150 arfd = STDOUT_FILENO; 151 arcname = STDO; 152 } else if ((arfd = open(name, APP_MODE, DMOD)) < 0) 153 syswarn(1, errno, "Failed open to read/write on %s", 154 name); 155 break; 156 case COPY: 157 /* 158 * arfd not used in COPY mode 159 */ 160 arcname = _NONE; 161 lstrval = 1; 162 return(0); 163 } 164 if (arfd < 0) 165 return(-1); 166 167 if (chdname != NULL) 168 if (dochdir(chdname) == -1) { 169 return(-1); 170 } 171 /* 172 * set up is based on device type 173 */ 174 if (fstat(arfd, &arsb) < 0) { 175 syswarn(0, errno, "Failed stat on %s", arcname); 176 (void)close(arfd); 177 arfd = -1; 178 can_unlnk = 0; 179 return(-1); 180 } 181 if (S_ISDIR(arsb.st_mode)) { 182 paxwarn(0, "Cannot write an archive on top of a directory %s", 183 arcname); 184 (void)close(arfd); 185 arfd = -1; 186 can_unlnk = 0; 187 return(-1); 188 } 189 190#ifndef __APPLE__ 191 if (S_ISCHR(arsb.st_mode)) 192 artyp = ioctl(arfd, MTIOCGET, &mb) ? ISCHR : ISTAPE; 193 else 194#endif /* !__APPLE__ */ 195 if (S_ISBLK(arsb.st_mode)) 196 artyp = ISBLK; 197 else if ((lseek(arfd, (off_t)0L, SEEK_CUR) == -1) && (errno == ESPIPE)) 198 artyp = ISPIPE; 199 else 200 artyp = ISREG; 201 202 /* 203 * make sure we beyond any doubt that we only can unlink regular files 204 * we created 205 */ 206 if (artyp != ISREG) 207 can_unlnk = 0; 208 /* 209 * if we are writing, we are done 210 */ 211 if (act == ARCHIVE) { 212 blksz = rdblksz = wrblksz; 213 lstrval = 1; 214 return(0); 215 } 216 217 /* 218 * set default blksz on read. APPNDs writes rdblksz on the last volume 219 * On all new archive volumes, we shift to wrblksz (if the user 220 * specified one, otherwise we will continue to use rdblksz). We 221 * must set blocksize based on what kind of device the archive is 222 * stored. 223 */ 224 switch (artyp) { 225 case ISTAPE: 226 /* 227 * Tape drives come in at least two flavors. Those that support 228 * variable sized records and those that have fixed sized 229 * records. They must be treated differently. For tape drives 230 * that support variable sized records, we must make large 231 * reads to make sure we get the entire record, otherwise we 232 * will just get the first part of the record (up to size we 233 * asked). Tapes with fixed sized records may or may not return 234 * multiple records in a single read. We really do not care 235 * what the physical record size is UNLESS we are going to 236 * append. (We will need the physical block size to rewrite 237 * the trailer). Only when we are appending do we go to the 238 * effort to figure out the true PHYSICAL record size. 239 */ 240 blksz = rdblksz = MAXBLK; 241 break; 242 case ISPIPE: 243 case ISBLK: 244 case ISCHR: 245 /* 246 * Blocksize is not a major issue with these devices (but must 247 * be kept a multiple of 512). If the user specified a write 248 * block size, we use that to read. Under append, we must 249 * always keep blksz == rdblksz. Otherwise we go ahead and use 250 * the device optimal blocksize as (and if) returned by stat 251 * and if it is within pax specs. 252 */ 253 if ((act == APPND) && wrblksz) { 254 blksz = rdblksz = wrblksz; 255 break; 256 } 257 258 if ((arsb.st_blksize > 0) && (arsb.st_blksize < MAXBLK) && 259 ((arsb.st_blksize % BLKMULT) == 0)) 260 rdblksz = arsb.st_blksize; 261 else 262 rdblksz = DEVBLK; 263 /* 264 * For performance go for large reads when we can without harm 265 */ 266 if ((act == APPND) || (artyp == ISCHR)) 267 blksz = rdblksz; 268 else 269 blksz = MAXBLK; 270 break; 271 case ISREG: 272 /* 273 * if the user specified wrblksz works, use it. Under appends 274 * we must always keep blksz == rdblksz 275 */ 276 if ((act == APPND) && wrblksz && ((arsb.st_size%wrblksz)==0)){ 277 blksz = rdblksz = wrblksz; 278 break; 279 } 280 /* 281 * See if we can find the blocking factor from the file size 282 */ 283 for (rdblksz = MAXBLK; rdblksz > 0; rdblksz -= BLKMULT) 284 if ((arsb.st_size % rdblksz) == 0) 285 break; 286 /* 287 * When we cannot find a match, we may have a flawed archive. 288 */ 289 if (rdblksz <= 0) 290 rdblksz = FILEBLK; 291 /* 292 * for performance go for large reads when we can 293 */ 294 if (act == APPND) 295 blksz = rdblksz; 296 else 297 blksz = MAXBLK; 298 break; 299 default: 300 /* 301 * should never happen, worst case, slow... 302 */ 303 blksz = rdblksz = BLKMULT; 304 break; 305 } 306 lstrval = 1; 307 return(0); 308} 309 310/* 311 * ar_close() 312 * closes archive device, increments volume number, and prints i/o summary 313 */ 314void 315ar_close(void) 316{ 317 int status; 318 319 if (arfd < 0) { 320 did_io = io_ok = flcnt = 0; 321 return; 322 } 323 324 /* 325 * Close archive file. This may take a LONG while on tapes (we may be 326 * forced to wait for the rewind to complete) so tell the user what is 327 * going on (this avoids the user hitting control-c thinking pax is 328 * broken). 329 */ 330 if (vflag && (artyp == ISTAPE)) { 331 if (vfpart) 332 (void)putc('\n', listf); 333 (void)fprintf(listf, 334 "%s: Waiting for tape drive close to complete...", 335 argv0); 336 (void)fflush(listf); 337 } 338 339 /* 340 * if nothing was written to the archive (and we created it), we remove 341 * it 342 */ 343 if (can_unlnk && (fstat(arfd, &arsb) == 0) && (S_ISREG(arsb.st_mode)) && 344 (arsb.st_size == 0)) { 345 (void)unlink(arcname); 346 can_unlnk = 0; 347 } 348 349 /* 350 * for a quick extract/list, pax frequently exits before the child 351 * process is done 352 */ 353 if ((act == LIST || act == EXTRACT) && nflag && zpid > 0) 354 kill(zpid, SIGINT); 355 356 (void)close(arfd); 357 358 /* Do not exit before child to ensure data integrity */ 359 if (zpid > 0) 360 waitpid(zpid, &status, 0); 361 362 if (vflag && (artyp == ISTAPE)) { 363 (void)fputs("done.\n", listf); 364 vfpart = 0; 365 (void)fflush(listf); 366 } 367 arfd = -1; 368 369 if (!io_ok && !did_io) { 370 flcnt = 0; 371 return; 372 } 373 did_io = io_ok = 0; 374 375 /* 376 * The volume number is only increased when the last device has data 377 * and we have already determined the archive format. 378 */ 379 if (frmt != NULL) 380 ++arvol; 381 382 if (!vflag) { 383 flcnt = 0; 384 return; 385 } 386 387 /* 388 * Print out a summary of I/O for this archive volume. 389 */ 390 if (vfpart) { 391 (void)putc('\n', listf); 392 vfpart = 0; 393 } 394 395 /* 396 * If we have not determined the format yet, we just say how many bytes 397 * we have skipped over looking for a header to id. there is no way we 398 * could have written anything yet. 399 */ 400 if (frmt == NULL) { 401# ifdef LONG_OFF_T 402 (void)fprintf(listf, "%s: unknown format, %lu bytes skipped.\n", 403# else 404 (void)fprintf(listf, "%s: unknown format, %qu bytes skipped.\n", 405# endif 406 argv0, rdcnt); 407 (void)fflush(listf); 408 flcnt = 0; 409 return; 410 } 411 412 if (strcmp(NM_CPIO, argv0) == 0) 413 (void)fprintf(listf, "%qu blocks\n", (rdcnt ? rdcnt : wrcnt) / 5120); 414 else if (strcmp(NM_TAR, argv0) != 0 && strcmp(NM_PAX, argv0) != 0) 415 (void)fprintf(listf, 416# ifdef LONG_OFF_T 417 "%s: %s vol %d, %lu files, %lu bytes read, %lu bytes written.\n", 418 argv0, frmt->name, arvol-1, flcnt, rdcnt, wrcnt); 419# else 420 "%s: %s vol %d, %lu files, %ju bytes read, %ju bytes written.\n", 421 argv0, frmt->name, arvol-1, flcnt, (uintmax_t)rdcnt, (uintmax_t)wrcnt); 422# endif 423 (void)fflush(listf); 424 flcnt = 0; 425} 426 427/* 428 * ar_drain() 429 * drain any archive format independent padding from an archive read 430 * from a socket or a pipe. This is to prevent the process on the 431 * other side of the pipe from getting a SIGPIPE (pax will stop 432 * reading an archive once a format dependent trailer is detected). 433 */ 434void 435ar_drain(void) 436{ 437 int res; 438 char drbuf[MAXBLK]; 439 440 /* 441 * we only drain from a pipe/socket. Other devices can be closed 442 * without reading up to end of file. We sure hope that pipe is closed 443 * on the other side so we will get an EOF. 444 */ 445 if ((artyp != ISPIPE) || (lstrval <= 0)) 446 return; 447 448 /* 449 * keep reading until pipe is drained 450 */ 451 while ((res = read(arfd, drbuf, sizeof(drbuf))) > 0) 452 ; 453 lstrval = res; 454} 455 456/* 457 * ar_set_wr() 458 * Set up device right before switching from read to write in an append. 459 * device dependent code (if required) to do this should be added here. 460 * For all archive devices we are already positioned at the place we want 461 * to start writing when this routine is called. 462 * Return: 463 * 0 if all ready to write, -1 otherwise 464 */ 465 466int 467ar_set_wr(void) 468{ 469 off_t cpos; 470 471 /* 472 * we must make sure the trailer is rewritten on append, ar_next() 473 * will stop us if the archive containing the trailer was not written 474 */ 475 wr_trail = 0; 476 477 /* 478 * Add any device dependent code as required here 479 */ 480 if (artyp != ISREG) 481 return(0); 482 /* 483 * Ok we have an archive in a regular file. If we were rewriting a 484 * file, we must get rid of all the stuff after the current offset 485 * (it was not written by pax). 486 */ 487 if (((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) || 488 (ftruncate(arfd, cpos) < 0)) { 489 syswarn(1, errno, "Unable to truncate archive file"); 490 return(-1); 491 } 492 return(0); 493} 494 495/* 496 * ar_app_ok() 497 * check if the last volume in the archive allows appends. We cannot check 498 * this until we are ready to write since there is no spec that says all 499 * volumes in a single archive have to be of the same type... 500 * Return: 501 * 0 if we can append, -1 otherwise. 502 */ 503 504int 505ar_app_ok(void) 506{ 507 if (artyp == ISPIPE) { 508 paxwarn(1, "Cannot append to an archive obtained from a pipe."); 509 return(-1); 510 } 511 512 if (!invld_rec) 513 return(0); 514 paxwarn(1,"Cannot append, device record size %d does not support %s spec", 515 rdblksz, argv0); 516 return(-1); 517} 518 519/* 520 * ar_read() 521 * read up to a specified number of bytes from the archive into the 522 * supplied buffer. When dealing with tapes we may not always be able to 523 * read what we want. 524 * Return: 525 * Number of bytes in buffer. 0 for end of file, -1 for a read error. 526 */ 527 528int 529ar_read(char *buf, int cnt) 530{ 531 int res = 0; 532 533 /* 534 * if last i/o was in error, no more reads until reset or new volume 535 */ 536 if (lstrval <= 0) 537 return(lstrval); 538 539 /* 540 * how we read must be based on device type 541 */ 542 switch (artyp) { 543 case ISTAPE: 544 if ((res = read(arfd, buf, cnt)) > 0) { 545 /* 546 * CAUTION: tape systems may not always return the same 547 * sized records so we leave blksz == MAXBLK. The 548 * physical record size that a tape drive supports is 549 * very hard to determine in a uniform and portable 550 * manner. 551 */ 552 io_ok = 1; 553 if (res != rdblksz) { 554 /* 555 * Record size changed. If this happens on 556 * any record after the first, we probably have 557 * a tape drive which has a fixed record size 558 * (we are getting multiple records in a single 559 * read). Watch out for record blocking that 560 * violates pax spec (must be a multiple of 561 * BLKMULT). 562 */ 563 rdblksz = res; 564 if (rdblksz % BLKMULT) 565 invld_rec = 1; 566 } 567 return(res); 568 } 569 break; 570 case ISREG: 571 case ISBLK: 572 case ISCHR: 573 case ISPIPE: 574 default: 575 /* 576 * Files are so easy to deal with. These other things cannot 577 * be trusted at all. So when we are dealing with character 578 * devices and pipes we just take what they have ready for us 579 * and return. Trying to do anything else with them runs the 580 * risk of failure. 581 */ 582 if ((res = read(arfd, buf, cnt)) > 0) { 583 io_ok = 1; 584 return(res); 585 } 586 break; 587 } 588 589 /* 590 * We are in trouble at this point, something is broken... 591 */ 592 lstrval = res; 593 if (res < 0) 594 syswarn(1, errno, "Failed read on archive volume %d", arvol); 595 else 596 paxwarn(0, "End of archive volume %d reached", arvol); 597 return(res); 598} 599 600/* 601 * ar_write() 602 * Write a specified number of bytes in supplied buffer to the archive 603 * device so it appears as a single "block". Deals with errors and tries 604 * to recover when faced with short writes. 605 * Return: 606 * Number of bytes written. 0 indicates end of volume reached and with no 607 * flaws (as best that can be detected). A -1 indicates an unrecoverable 608 * error in the archive occurred. 609 */ 610 611int 612ar_write(char *buf, int bsz) 613{ 614 int res; 615 off_t cpos; 616 617 /* 618 * do not allow pax to create a "bad" archive. Once a write fails on 619 * an archive volume prevent further writes to it. 620 */ 621 if (lstrval <= 0) 622 return(lstrval); 623 624 if ((res = write(arfd, buf, bsz)) == bsz) { 625 wr_trail = 1; 626 io_ok = 1; 627 return(bsz); 628 } else if (res < 0 && artyp == ISPIPE && errno == EPIPE) { /* ignore it */ 629 wr_trail = 1; 630 io_ok = 1; 631 errno = 0; 632 arfd = open("/dev/null", AR_MODE, DMOD); 633 artyp = ISREG; 634 return bsz; 635 } 636 637 /* 638 * write broke, see what we can do with it. We try to send any partial 639 * writes that may violate pax spec to the next archive volume. 640 */ 641 if (res < 0) 642 lstrval = res; 643 else 644 lstrval = 0; 645 646 switch (artyp) { 647 case ISREG: 648 if ((res > 0) && (res % BLKMULT)) { 649 /* 650 * try to fix up partial writes which are not BLKMULT 651 * in size by forcing the runt record to next archive 652 * volume 653 */ 654 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 655 break; 656 cpos -= (off_t)res; 657 if (ftruncate(arfd, cpos) < 0) 658 break; 659 res = lstrval = 0; 660 break; 661 } 662 if (res >= 0) 663 break; 664 /* 665 * if file is out of space, handle it like a return of 0 666 */ 667 if ((errno == ENOSPC) || (errno == EFBIG) || (errno == EDQUOT)) 668 res = lstrval = 0; 669 break; 670 case ISTAPE: 671 case ISCHR: 672 case ISBLK: 673 if (res >= 0) 674 break; 675 if (errno == EACCES) { 676 paxwarn(0, "Write failed, archive is write protected."); 677 lstrval = 0; 678 return(0); 679 } 680 /* 681 * see if we reached the end of media, if so force a change to 682 * the next volume 683 */ 684 if ((errno == ENOSPC) || (errno == EIO) || (errno == ENXIO)) 685 res = lstrval = 0; 686 break; 687 case ISPIPE: 688 default: 689 /* 690 * we cannot fix errors to these devices 691 */ 692 break; 693 } 694 695 /* 696 * Better tell the user the bad news... 697 * if this is a block aligned archive format, we may have a bad archive 698 * if the format wants the header to start at a BLKMULT boundary.. While 699 * we can deal with the mis-aligned data, it violates spec and other 700 * archive readers will likely fail. if the format is not block 701 * aligned, the user may be lucky (and the archive is ok). 702 */ 703 if (res >= 0) { 704 if (res > 0) 705 wr_trail = 1; 706 io_ok = 1; 707 } 708 709 /* 710 * If we were trying to rewrite the trailer and it didn't work, we 711 * must quit right away. 712 */ 713 if (!wr_trail && (res <= 0)) { 714 paxwarn(1,"Unable to append, trailer re-write failed. Quitting."); 715 return(res); 716 } 717 718 if (res == 0) 719 paxwarn(0, "End of archive volume %d reached", arvol); 720 else if (res < 0) 721 syswarn(1, errno, "Failed write to archive volume: %d", arvol); 722 else if (!frmt->blkalgn || ((res % frmt->blkalgn) == 0)) 723 paxwarn(0,"WARNING: partial archive write. Archive MAY BE FLAWED"); 724 else 725 paxwarn(1,"WARNING: partial archive write. Archive IS FLAWED"); 726 return(res); 727} 728 729/* 730 * ar_rdsync() 731 * Try to move past a bad spot on a flawed archive as needed to continue 732 * I/O. Clears error flags to allow I/O to continue. 733 * Return: 734 * 0 when ok to try i/o again, -1 otherwise. 735 */ 736 737int 738ar_rdsync(void) 739{ 740 long fsbz; 741 off_t cpos; 742 off_t mpos; 743#ifndef __APPLE__ 744 struct mtop mb; 745#endif /* !__APPLE__ */ 746 747 /* 748 * Fail resync attempts at user request (done) or if this is going to be 749 * an update/append to a existing archive. if last i/o hit media end, 750 * we need to go to the next volume not try a resync 751 */ 752 if ((done > 0) || (lstrval == 0)) 753 return(-1); 754 755 if ((act == APPND) || (act == ARCHIVE)) { 756 paxwarn(1, "Cannot allow updates to an archive with flaws."); 757 return(-1); 758 } 759 if (io_ok) 760 did_io = 1; 761 762 switch (artyp) { 763#ifndef __APPLE__ 764 case ISTAPE: 765 /* 766 * if the last i/o was a successful data transfer, we assume 767 * the fault is just a bad record on the tape that we are now 768 * past. If we did not get any data since the last resync try 769 * to move the tape forward one PHYSICAL record past any 770 * damaged tape section. Some tape drives are stubborn and need 771 * to be pushed. 772 */ 773 if (io_ok) { 774 io_ok = 0; 775 lstrval = 1; 776 break; 777 } 778 mb.mt_op = MTFSR; 779 mb.mt_count = 1; 780 if (ioctl(arfd, MTIOCTOP, &mb) < 0) 781 break; 782 lstrval = 1; 783 break; 784#endif /* !__APPLE__ */ 785 case ISREG: 786 case ISCHR: 787 case ISBLK: 788 /* 789 * try to step over the bad part of the device. 790 */ 791 io_ok = 0; 792 if (((fsbz = arsb.st_blksize) <= 0) || (artyp != ISREG)) 793 fsbz = BLKMULT; 794 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 795 break; 796 mpos = fsbz - (cpos % (off_t)fsbz); 797 if (lseek(arfd, mpos, SEEK_CUR) < 0) 798 break; 799 lstrval = 1; 800 break; 801 case ISPIPE: 802 default: 803 /* 804 * cannot recover on these archive device types 805 */ 806 io_ok = 0; 807 break; 808 } 809 if (lstrval <= 0) { 810 paxwarn(1, "Unable to recover from an archive read failure."); 811 return(-1); 812 } 813 paxwarn(0, "Attempting to recover from an archive read failure."); 814 return(0); 815} 816 817/* 818 * ar_fow() 819 * Move the I/O position within the archive forward the specified number of 820 * bytes as supported by the device. If we cannot move the requested 821 * number of bytes, return the actual number of bytes moved in skipped. 822 * Return: 823 * 0 if moved the requested distance, -1 on complete failure, 1 on 824 * partial move (the amount moved is in skipped) 825 */ 826 827int 828ar_fow(off_t sksz, off_t *skipped) 829{ 830 off_t cpos; 831 off_t mpos; 832 833 *skipped = 0; 834 if (sksz <= 0) 835 return(0); 836 837 /* 838 * we cannot move forward at EOF or error 839 */ 840 if (lstrval <= 0) 841 return(lstrval); 842 843 /* 844 * Safer to read forward on devices where it is hard to find the end of 845 * the media without reading to it. With tapes we cannot be sure of the 846 * number of physical blocks to skip (we do not know physical block 847 * size at this point), so we must only read forward on tapes! 848 */ 849 if (artyp != ISREG) 850 return(0); 851 852 /* 853 * figure out where we are in the archive 854 */ 855 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) >= 0) { 856 /* 857 * we can be asked to move farther than there are bytes in this 858 * volume, if so, just go to file end and let normal buf_fill() 859 * deal with the end of file (it will go to next volume by 860 * itself) 861 */ 862 if ((mpos = cpos + sksz) > arsb.st_size) { 863 *skipped = arsb.st_size - cpos; 864 mpos = arsb.st_size; 865 } else 866 *skipped = sksz; 867 if (lseek(arfd, mpos, SEEK_SET) >= 0) 868 return(0); 869 } 870 syswarn(1, errno, "Forward positioning operation on archive failed"); 871 lstrval = -1; 872 return(-1); 873} 874 875/* 876 * ar_rev() 877 * move the i/o position within the archive backwards the specified byte 878 * count as supported by the device. With tapes drives we RESET rdblksz to 879 * the PHYSICAL blocksize. 880 * NOTE: We should only be called to move backwards so we can rewrite the 881 * last records (the trailer) of an archive (APPEND). 882 * Return: 883 * 0 if moved the requested distance, -1 on complete failure 884 */ 885 886int 887ar_rev(off_t sksz) 888{ 889 off_t cpos; 890#ifndef __APPLE__ 891 struct mtop mb; 892 int phyblk; 893#endif /* __APPLE__ */ 894 895 /* 896 * make sure we do not have try to reverse on a flawed archive 897 */ 898 if (lstrval < 0) 899 return(lstrval); 900 901 switch (artyp) { 902 case ISPIPE: 903 if (sksz <= 0) 904 break; 905 /* 906 * cannot go backwards on these critters 907 */ 908 paxwarn(1, "Reverse positioning on pipes is not supported."); 909 lstrval = -1; 910 return(-1); 911 case ISREG: 912 case ISBLK: 913 case ISCHR: 914 default: 915 if (sksz <= 0) 916 break; 917 918 /* 919 * For things other than files, backwards movement has a very 920 * high probability of failure as we really do not know the 921 * true attributes of the device we are talking to (the device 922 * may not even have the ability to lseek() in any direction). 923 * First we figure out where we are in the archive. 924 */ 925 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) { 926 syswarn(1, errno, 927 "Unable to obtain current archive byte offset"); 928 lstrval = -1; 929 return(-1); 930 } 931 932 /* 933 * we may try to go backwards past the start when the archive 934 * is only a single record. If this happens and we are on a 935 * multi-volume archive, we need to go to the end of the 936 * previous volume and continue our movement backwards from 937 * there. 938 */ 939 if ((cpos -= sksz) < (off_t)0L) { 940 if (arvol > 1) { 941 /* 942 * this should never happen 943 */ 944 paxwarn(1,"Reverse position on previous volume."); 945 lstrval = -1; 946 return(-1); 947 } 948 cpos = (off_t)0L; 949 } 950 if (lseek(arfd, cpos, SEEK_SET) < 0) { 951 syswarn(1, errno, "Unable to seek archive backwards"); 952 lstrval = -1; 953 return(-1); 954 } 955 break; 956#ifndef __APPLE__ 957 case ISTAPE: 958 /* 959 * Calculate and move the proper number of PHYSICAL tape 960 * blocks. If the sksz is not an even multiple of the physical 961 * tape size, we cannot do the move (this should never happen). 962 * (We also cannot handle trailers spread over two vols.) 963 * get_phys() also makes sure we are in front of the filemark. 964 */ 965 if ((phyblk = get_phys()) <= 0) { 966 lstrval = -1; 967 return(-1); 968 } 969 970 /* 971 * make sure future tape reads only go by physical tape block 972 * size (set rdblksz to the real size). 973 */ 974 rdblksz = phyblk; 975 976 /* 977 * if no movement is required, just return (we must be after 978 * get_phys() so the physical blocksize is properly set) 979 */ 980 if (sksz <= 0) 981 break; 982 983 /* 984 * ok we have to move. Make sure the tape drive can do it. 985 */ 986 if (sksz % phyblk) { 987 paxwarn(1, 988 "Tape drive unable to backspace requested amount"); 989 lstrval = -1; 990 return(-1); 991 } 992 993 /* 994 * move backwards the requested number of bytes 995 */ 996 mb.mt_op = MTBSR; 997 mb.mt_count = sksz/phyblk; 998 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 999 syswarn(1,errno, "Unable to backspace tape %d blocks.", 1000 mb.mt_count); 1001 lstrval = -1; 1002 return(-1); 1003 } 1004 break; 1005#endif /* !__APPLE__ */ 1006 } 1007 lstrval = 1; 1008 return(0); 1009} 1010#ifndef __APPLE__ 1011/* 1012 * get_phys() 1013 * Determine the physical block size on a tape drive. We need the physical 1014 * block size so we know how many bytes we skip over when we move with 1015 * mtio commands. We also make sure we are BEFORE THE TAPE FILEMARK when 1016 * return. 1017 * This is one really SLOW routine... 1018 * Return: 1019 * physical block size if ok (ok > 0), -1 otherwise 1020 */ 1021 1022static int 1023get_phys(void) 1024{ 1025 int padsz = 0; 1026 int res; 1027 int phyblk; 1028 struct mtop mb; 1029 char scbuf[MAXBLK]; 1030 1031 /* 1032 * move to the file mark, and then back up one record and read it. 1033 * this should tell us the physical record size the tape is using. 1034 */ 1035 if (lstrval == 1) { 1036 /* 1037 * we know we are at file mark when we get back a 0 from 1038 * read() 1039 */ 1040 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1041 padsz += res; 1042 if (res < 0) { 1043 syswarn(1, errno, "Unable to locate tape filemark."); 1044 return(-1); 1045 } 1046 } 1047 1048 /* 1049 * move backwards over the file mark so we are at the end of the 1050 * last record. 1051 */ 1052 mb.mt_op = MTBSF; 1053 mb.mt_count = 1; 1054 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1055 syswarn(1, errno, "Unable to backspace over tape filemark."); 1056 return(-1); 1057 } 1058 1059 /* 1060 * move backwards so we are in front of the last record and read it to 1061 * get physical tape blocksize. 1062 */ 1063 mb.mt_op = MTBSR; 1064 mb.mt_count = 1; 1065 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1066 syswarn(1, errno, "Unable to backspace over last tape block."); 1067 return(-1); 1068 } 1069 if ((phyblk = read(arfd, scbuf, sizeof(scbuf))) <= 0) { 1070 syswarn(1, errno, "Cannot determine archive tape blocksize."); 1071 return(-1); 1072 } 1073 1074 /* 1075 * read forward to the file mark, then back up in front of the filemark 1076 * (this is a bit paranoid, but should be safe to do). 1077 */ 1078 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1079 ; 1080 if (res < 0) { 1081 syswarn(1, errno, "Unable to locate tape filemark."); 1082 return(-1); 1083 } 1084 mb.mt_op = MTBSF; 1085 mb.mt_count = 1; 1086 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1087 syswarn(1, errno, "Unable to backspace over tape filemark."); 1088 return(-1); 1089 } 1090 1091 /* 1092 * set lstrval so we know that the filemark has not been seen 1093 */ 1094 lstrval = 1; 1095 1096 /* 1097 * return if there was no padding 1098 */ 1099 if (padsz == 0) 1100 return(phyblk); 1101 1102 /* 1103 * make sure we can move backwards over the padding. (this should 1104 * never fail). 1105 */ 1106 if (padsz % phyblk) { 1107 paxwarn(1, "Tape drive unable to backspace requested amount"); 1108 return(-1); 1109 } 1110 1111 /* 1112 * move backwards over the padding so the head is where it was when 1113 * we were first called (if required). 1114 */ 1115 mb.mt_op = MTBSR; 1116 mb.mt_count = padsz/phyblk; 1117 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1118 syswarn(1,errno,"Unable to backspace tape over %d pad blocks", 1119 mb.mt_count); 1120 return(-1); 1121 } 1122 return(phyblk); 1123} 1124#endif /* !__APPLE__ */ 1125/* 1126 * ar_next() 1127 * prompts the user for the next volume in this archive. For some devices 1128 * we may allow the media to be changed. Otherwise a new archive is 1129 * prompted for. By pax spec, if there is no controlling tty or an eof is 1130 * read on tty input, we must quit pax. 1131 * Return: 1132 * 0 when ready to continue, -1 when all done 1133 */ 1134 1135int 1136ar_next(void) 1137{ 1138 char buf[PAXPATHLEN+2]; 1139 static int freeit = 0; 1140 sigset_t o_mask; 1141 1142 /* 1143 * WE MUST CLOSE THE DEVICE. A lot of devices must see last close, (so 1144 * things like writing EOF etc will be done) (Watch out ar_close() can 1145 * also be called via a signal handler, so we must prevent a race. 1146 */ 1147 if (sigprocmask(SIG_BLOCK, &s_mask, &o_mask) < 0) 1148 syswarn(0, errno, "Unable to set signal mask"); 1149 ar_close(); 1150 if (sigprocmask(SIG_SETMASK, &o_mask, NULL) < 0) 1151 syswarn(0, errno, "Unable to restore signal mask"); 1152 1153 if (frmt == NULL || done || !wr_trail || force_one_volume || strcmp(NM_TAR, argv0) == 0 || 1154 strcmp(NM_PAX, argv0) == 0) 1155 return(-1); 1156 1157 tty_prnt("\nATTENTION! %s archive volume change required.\n", argv0); 1158 1159 /* 1160 * if i/o is on stdin or stdout, we cannot reopen it (we do not know 1161 * the name), the user will be forced to type it in. 1162 */ 1163 if (strcmp(arcname, STDO) && strcmp(arcname, STDN) && (artyp != ISREG) 1164 && (artyp != ISPIPE)) { 1165 if (artyp == ISTAPE) { 1166 tty_prnt("%s ready for archive tape volume: %d\n", 1167 arcname, arvol); 1168 tty_prnt("Load the NEXT TAPE on the tape drive"); 1169 } else { 1170 tty_prnt("%s ready for archive volume: %d\n", 1171 arcname, arvol); 1172 tty_prnt("Load the NEXT STORAGE MEDIA (if required)"); 1173 } 1174 1175 if ((act == ARCHIVE) || (act == APPND)) 1176 tty_prnt(" and make sure it is WRITE ENABLED.\n"); 1177 else 1178 tty_prnt("\n"); 1179 1180 for (;;) { 1181 tty_prnt("Type \"y\" to continue, \".\" to quit %s,", 1182 argv0); 1183 tty_prnt(" or \"s\" to switch to new device.\nIf you"); 1184 tty_prnt(" cannot change storage media, type \"s\"\n"); 1185 tty_prnt("Is the device ready and online? > "); 1186 1187 if ((tty_read(buf,sizeof(buf))<0) || !strcmp(buf,".")){ 1188 done = 1; 1189 lstrval = -1; 1190 tty_prnt("Quitting %s!\n", argv0); 1191 vfpart = 0; 1192 return(-1); 1193 } 1194 1195 if ((buf[0] == '\0') || (buf[1] != '\0')) { 1196 tty_prnt("%s unknown command, try again\n",buf); 1197 continue; 1198 } 1199 1200 switch (buf[0]) { 1201 case 'y': 1202 case 'Y': 1203 /* 1204 * we are to continue with the same device 1205 */ 1206 if (ar_open(arcname) >= 0) 1207 return(0); 1208 tty_prnt("Cannot re-open %s, try again\n", 1209 arcname); 1210 continue; 1211 case 's': 1212 case 'S': 1213 /* 1214 * user wants to open a different device 1215 */ 1216 tty_prnt("Switching to a different archive\n"); 1217 break; 1218 default: 1219 tty_prnt("%s unknown command, try again\n",buf); 1220 continue; 1221 } 1222 break; 1223 } 1224 } else 1225 tty_prnt("Ready for archive volume: %d\n", arvol); 1226 1227 /* 1228 * have to go to a different archive 1229 */ 1230 for (;;) { 1231 tty_prnt("Input archive name or \".\" to quit %s.\n", argv0); 1232 tty_prnt("Archive name > "); 1233 1234 if ((tty_read(buf, sizeof(buf)) < 0) || !strcmp(buf, ".")) { 1235 done = 1; 1236 lstrval = -1; 1237 tty_prnt("Quitting %s!\n", argv0); 1238 vfpart = 0; 1239 return(-1); 1240 } 1241 if (buf[0] == '\0') { 1242 tty_prnt("Empty file name, try again\n"); 1243 continue; 1244 } 1245 if (!strcmp(buf, "..")) { 1246 tty_prnt("Illegal file name: .. try again\n"); 1247 continue; 1248 } 1249 if (strlen(buf) > PAXPATHLEN) { 1250 tty_prnt("File name too long, try again\n"); 1251 continue; 1252 } 1253 1254 /* 1255 * try to open new archive 1256 */ 1257 if (ar_open(buf) >= 0) { 1258 if (freeit) { 1259 (void)free((char *)arcname); 1260 freeit = 0; 1261 } 1262 if ((arcname = strdup(buf)) == NULL) { 1263 done = 1; 1264 lstrval = -1; 1265 paxwarn(0, "Cannot save archive name."); 1266 return(-1); 1267 } 1268 freeit = 1; 1269 break; 1270 } 1271 tty_prnt("Cannot open %s, try again\n", buf); 1272 continue; 1273 } 1274 return(0); 1275} 1276 1277/* 1278 * ar_start_gzip() 1279 * starts the gzip compression/decompression process as a child, using magic 1280 * to keep the fd the same in the calling function (parent). 1281 */ 1282void 1283ar_start_gzip(int fd, const char *gzip_program, int wr) 1284{ 1285 int fds[2]; 1286 const char *gzip_flags = NULL; 1287 1288 if (pipe(fds) < 0) 1289 err(1, "could not pipe"); 1290 zpid = fork(); 1291 if (zpid < 0) 1292 err(1, "could not fork"); 1293 1294 /* parent */ 1295 if (zpid) { 1296 if (wr) 1297 dup2(fds[1], fd); 1298 else 1299 dup2(fds[0], fd); 1300 close(fds[0]); 1301 close(fds[1]); 1302 } else { 1303 if (wr) { 1304 dup2(fds[0], STDIN_FILENO); 1305 dup2(fd, STDOUT_FILENO); 1306 gzip_flags = "-c"; 1307 } else { 1308 dup2(fds[1], STDOUT_FILENO); 1309 dup2(fd, STDIN_FILENO); 1310 gzip_flags = "-dc"; 1311 } 1312 close(fds[0]); 1313 close(fds[1]); 1314 if (execlp(gzip_program, gzip_program, gzip_flags, (char *)NULL) < 0) 1315 err(1, "could not exec %s", gzip_program); 1316 /* NOTREACHED */ 1317 } 1318} 1319