1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1992 Keith Muller. 5 * Copyright (c) 1992, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Keith Muller of the University of California, San Diego. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/types.h> 37 #include <sys/ioctl.h> 38 #include <sys/mtio.h> 39 #include <sys/stat.h> 40 #include <sys/wait.h> 41 #include <err.h> 42 #include <errno.h> 43 #include <fcntl.h> 44 #include <signal.h> 45 #include <stdint.h> 46 #include <stdio.h> 47 #include <string.h> 48 #include <stdlib.h> 49 #include <unistd.h> 50 #include "pax.h" 51 #include "options.h" 52 #include "extern.h" 53 54 /* 55 * Routines which deal directly with the archive I/O device/file. 56 */ 57 58 #define DMOD 0666 /* default mode of created archives */ 59 #define EXT_MODE O_RDONLY /* open mode for list/extract */ 60 #define AR_MODE (O_WRONLY | O_CREAT | O_TRUNC) /* mode for archive */ 61 #define APP_MODE O_RDWR /* mode for append */ 62 63 static char none[] = "<NONE>"; /* pseudo name for no file */ 64 static char stdo[] = "<STDOUT>"; /* pseudo name for stdout */ 65 static char stdn[] = "<STDIN>"; /* pseudo name for stdin */ 66 static int arfd = -1; /* archive file descriptor */ 67 static int artyp = ISREG; /* archive type: file/FIFO/tape */ 68 static int arvol = 1; /* archive volume number */ 69 static int lstrval = -1; /* return value from last i/o */ 70 static int io_ok; /* i/o worked on volume after resync */ 71 static int did_io; /* did i/o ever occur on volume? */ 72 static int done; /* set via tty termination */ 73 static struct stat arsb; /* stat of archive device at open */ 74 static int invld_rec; /* tape has out of spec record size */ 75 static int wr_trail = 1; /* trailer was rewritten in append */ 76 static int can_unlnk = 0; /* do we unlink null archives? */ 77 const char *arcname; /* printable name of archive */ 78 const char *gzip_program; /* name of gzip program */ 79 static pid_t zpid = -1; /* pid of child process */ 80 81 static int get_phys(void); 82 static void ar_start_gzip(int, const char *, int); 83 84 /* 85 * ar_open() 86 * Opens the next archive volume. Determines the type of the device and 87 * sets up block sizes as required by the archive device and the format. 88 * Note: we may be called with name == NULL on the first open only. 89 * Return: 90 * -1 on failure, 0 otherwise 91 */ 92 93 int 94 ar_open(const char *name) 95 { 96 struct mtget mb; 97 98 if (arfd != -1) 99 (void)close(arfd); 100 arfd = -1; 101 can_unlnk = did_io = io_ok = invld_rec = 0; 102 artyp = ISREG; 103 flcnt = 0; 104 105 /* 106 * open based on overall operation mode 107 */ 108 switch (act) { 109 case LIST: 110 case EXTRACT: 111 if (name == NULL) { 112 arfd = STDIN_FILENO; 113 arcname = stdn; 114 } else if ((arfd = open(name, EXT_MODE, DMOD)) < 0) 115 syswarn(0, errno, "Failed open to read on %s", name); 116 if (arfd != -1 && gzip_program != NULL) 117 ar_start_gzip(arfd, gzip_program, 0); 118 break; 119 case ARCHIVE: 120 if (name == NULL) { 121 arfd = STDOUT_FILENO; 122 arcname = stdo; 123 } else if ((arfd = open(name, AR_MODE, DMOD)) < 0) 124 syswarn(0, errno, "Failed open to write on %s", name); 125 else 126 can_unlnk = 1; 127 if (arfd != -1 && gzip_program != NULL) 128 ar_start_gzip(arfd, gzip_program, 1); 129 break; 130 case APPND: 131 if (name == NULL) { 132 arfd = STDOUT_FILENO; 133 arcname = stdo; 134 } else if ((arfd = open(name, APP_MODE, DMOD)) < 0) 135 syswarn(0, errno, "Failed open to read/write on %s", 136 name); 137 break; 138 case COPY: 139 /* 140 * arfd not used in COPY mode 141 */ 142 arcname = none; 143 lstrval = 1; 144 return(0); 145 } 146 if (arfd < 0) 147 return(-1); 148 149 if (chdname != NULL) 150 if (chdir(chdname) != 0) { 151 syswarn(1, errno, "Failed chdir to %s", chdname); 152 return(-1); 153 } 154 /* 155 * set up is based on device type 156 */ 157 if (fstat(arfd, &arsb) < 0) { 158 syswarn(0, errno, "Failed stat on %s", arcname); 159 (void)close(arfd); 160 arfd = -1; 161 can_unlnk = 0; 162 return(-1); 163 } 164 if (S_ISDIR(arsb.st_mode)) { 165 paxwarn(0, "Cannot write an archive on top of a directory %s", 166 arcname); 167 (void)close(arfd); 168 arfd = -1; 169 can_unlnk = 0; 170 return(-1); 171 } 172 173 if (S_ISCHR(arsb.st_mode)) 174 artyp = ioctl(arfd, MTIOCGET, &mb) ? ISCHR : ISTAPE; 175 else if (S_ISBLK(arsb.st_mode)) 176 artyp = ISBLK; 177 else if ((lseek(arfd, (off_t)0L, SEEK_CUR) == -1) && (errno == ESPIPE)) 178 artyp = ISPIPE; 179 else 180 artyp = ISREG; 181 182 /* 183 * make sure we beyond any doubt that we only can unlink regular files 184 * we created 185 */ 186 if (artyp != ISREG) 187 can_unlnk = 0; 188 /* 189 * if we are writing, we are done 190 */ 191 if (act == ARCHIVE) { 192 blksz = rdblksz = wrblksz; 193 lstrval = 1; 194 return(0); 195 } 196 197 /* 198 * set default blksz on read. APPNDs writes rdblksz on the last volume 199 * On all new archive volumes, we shift to wrblksz (if the user 200 * specified one, otherwise we will continue to use rdblksz). We 201 * must set blocksize based on what kind of device the archive is 202 * stored. 203 */ 204 switch(artyp) { 205 case ISTAPE: 206 /* 207 * Tape drives come in at least two flavors. Those that support 208 * variable sized records and those that have fixed sized 209 * records. They must be treated differently. For tape drives 210 * that support variable sized records, we must make large 211 * reads to make sure we get the entire record, otherwise we 212 * will just get the first part of the record (up to size we 213 * asked). Tapes with fixed sized records may or may not return 214 * multiple records in a single read. We really do not care 215 * what the physical record size is UNLESS we are going to 216 * append. (We will need the physical block size to rewrite 217 * the trailer). Only when we are appending do we go to the 218 * effort to figure out the true PHYSICAL record size. 219 */ 220 blksz = rdblksz = MAXBLK; 221 break; 222 case ISPIPE: 223 case ISBLK: 224 case ISCHR: 225 /* 226 * Blocksize is not a major issue with these devices (but must 227 * be kept a multiple of 512). If the user specified a write 228 * block size, we use that to read. Under append, we must 229 * always keep blksz == rdblksz. Otherwise we go ahead and use 230 * the device optimal blocksize as (and if) returned by stat 231 * and if it is within pax specs. 232 */ 233 if ((act == APPND) && wrblksz) { 234 blksz = rdblksz = wrblksz; 235 break; 236 } 237 238 if ((arsb.st_blksize > 0) && (arsb.st_blksize < MAXBLK) && 239 ((arsb.st_blksize % BLKMULT) == 0)) 240 rdblksz = arsb.st_blksize; 241 else 242 rdblksz = DEVBLK; 243 /* 244 * For performance go for large reads when we can without harm 245 */ 246 if ((act == APPND) || (artyp == ISCHR)) 247 blksz = rdblksz; 248 else 249 blksz = MAXBLK; 250 break; 251 case ISREG: 252 /* 253 * if the user specified wrblksz works, use it. Under appends 254 * we must always keep blksz == rdblksz 255 */ 256 if ((act == APPND) && wrblksz && ((arsb.st_size%wrblksz)==0)){ 257 blksz = rdblksz = wrblksz; 258 break; 259 } 260 /* 261 * See if we can find the blocking factor from the file size 262 */ 263 for (rdblksz = MAXBLK; rdblksz > 0; rdblksz -= BLKMULT) 264 if ((arsb.st_size % rdblksz) == 0) 265 break; 266 /* 267 * When we cannot find a match, we may have a flawed archive. 268 */ 269 if (rdblksz <= 0) 270 rdblksz = FILEBLK; 271 /* 272 * for performance go for large reads when we can 273 */ 274 if (act == APPND) 275 blksz = rdblksz; 276 else 277 blksz = MAXBLK; 278 break; 279 default: 280 /* 281 * should never happen, worst case, slow... 282 */ 283 blksz = rdblksz = BLKMULT; 284 break; 285 } 286 lstrval = 1; 287 return(0); 288 } 289 290 /* 291 * ar_close() 292 * closes archive device, increments volume number, and prints i/o summary 293 */ 294 void 295 ar_close(void) 296 { 297 int status; 298 299 if (arfd < 0) { 300 did_io = io_ok = flcnt = 0; 301 return; 302 } 303 304 /* 305 * Close archive file. This may take a LONG while on tapes (we may be 306 * forced to wait for the rewind to complete) so tell the user what is 307 * going on (this avoids the user hitting control-c thinking pax is 308 * broken). 309 */ 310 if (vflag && (artyp == ISTAPE)) { 311 if (vfpart) 312 (void)putc('\n', listf); 313 (void)fprintf(listf, 314 "%s: Waiting for tape drive close to complete...", 315 argv0); 316 (void)fflush(listf); 317 } 318 319 /* 320 * if nothing was written to the archive (and we created it), we remove 321 * it 322 */ 323 if (can_unlnk && (fstat(arfd, &arsb) == 0) && (S_ISREG(arsb.st_mode)) && 324 (arsb.st_size == 0)) { 325 (void)unlink(arcname); 326 can_unlnk = 0; 327 } 328 329 /* 330 * for a quick extract/list, pax frequently exits before the child 331 * process is done 332 */ 333 if ((act == LIST || act == EXTRACT) && nflag && zpid > 0) 334 kill(zpid, SIGINT); 335 336 (void)close(arfd); 337 338 /* Do not exit before child to ensure data integrity */ 339 if (zpid > 0) 340 waitpid(zpid, &status, 0); 341 342 if (vflag && (artyp == ISTAPE)) { 343 (void)fputs("done.\n", listf); 344 vfpart = 0; 345 (void)fflush(listf); 346 } 347 arfd = -1; 348 349 if (!io_ok && !did_io) { 350 flcnt = 0; 351 return; 352 } 353 did_io = io_ok = 0; 354 355 /* 356 * The volume number is only increased when the last device has data 357 * and we have already determined the archive format. 358 */ 359 if (frmt != NULL) 360 ++arvol; 361 362 if (!vflag) { 363 flcnt = 0; 364 return; 365 } 366 367 /* 368 * Print out a summary of I/O for this archive volume. 369 */ 370 if (vfpart) { 371 (void)putc('\n', listf); 372 vfpart = 0; 373 } 374 375 /* 376 * If we have not determined the format yet, we just say how many bytes 377 * we have skipped over looking for a header to id. There is no way we 378 * could have written anything yet. 379 */ 380 if (frmt == NULL) { 381 (void)fprintf(listf, "%s: unknown format, %ju bytes skipped.\n", 382 argv0, (uintmax_t)rdcnt); 383 (void)fflush(listf); 384 flcnt = 0; 385 return; 386 } 387 388 if (strcmp(NM_CPIO, argv0) == 0) 389 (void)fprintf(listf, "%llu blocks\n", 390 (unsigned long long)((rdcnt ? rdcnt : wrcnt) / 5120)); 391 else if (strcmp(NM_TAR, argv0) != 0) 392 (void)fprintf(listf, 393 "%s: %s vol %d, %ju files, %ju bytes read, %ju bytes written.\n", 394 argv0, frmt->name, arvol-1, (uintmax_t)flcnt, 395 (uintmax_t)rdcnt, (uintmax_t)wrcnt); 396 (void)fflush(listf); 397 flcnt = 0; 398 } 399 400 /* 401 * ar_drain() 402 * drain any archive format independent padding from an archive read 403 * from a socket or a pipe. This is to prevent the process on the 404 * other side of the pipe from getting a SIGPIPE (pax will stop 405 * reading an archive once a format dependent trailer is detected). 406 */ 407 void 408 ar_drain(void) 409 { 410 int res; 411 char drbuf[MAXBLK]; 412 413 /* 414 * we only drain from a pipe/socket. Other devices can be closed 415 * without reading up to end of file. We sure hope that pipe is closed 416 * on the other side so we will get an EOF. 417 */ 418 if ((artyp != ISPIPE) || (lstrval <= 0)) 419 return; 420 421 /* 422 * keep reading until pipe is drained 423 */ 424 while ((res = read(arfd, drbuf, sizeof(drbuf))) > 0) 425 ; 426 lstrval = res; 427 } 428 429 /* 430 * ar_set_wr() 431 * Set up device right before switching from read to write in an append. 432 * device dependent code (if required) to do this should be added here. 433 * For all archive devices we are already positioned at the place we want 434 * to start writing when this routine is called. 435 * Return: 436 * 0 if all ready to write, -1 otherwise 437 */ 438 439 int 440 ar_set_wr(void) 441 { 442 off_t cpos; 443 444 /* 445 * we must make sure the trailer is rewritten on append, ar_next() 446 * will stop us if the archive containing the trailer was not written 447 */ 448 wr_trail = 0; 449 450 /* 451 * Add any device dependent code as required here 452 */ 453 if (artyp != ISREG) 454 return(0); 455 /* 456 * Ok we have an archive in a regular file. If we were rewriting a 457 * file, we must get rid of all the stuff after the current offset 458 * (it was not written by pax). 459 */ 460 if (((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) || 461 (ftruncate(arfd, cpos) < 0)) { 462 syswarn(1, errno, "Unable to truncate archive file"); 463 return(-1); 464 } 465 return(0); 466 } 467 468 /* 469 * ar_app_ok() 470 * check if the last volume in the archive allows appends. We cannot check 471 * this until we are ready to write since there is no spec that says all 472 * volumes in a single archive have to be of the same type... 473 * Return: 474 * 0 if we can append, -1 otherwise. 475 */ 476 477 int 478 ar_app_ok(void) 479 { 480 if (artyp == ISPIPE) { 481 paxwarn(1, "Cannot append to an archive obtained from a pipe."); 482 return(-1); 483 } 484 485 if (!invld_rec) 486 return(0); 487 paxwarn(1,"Cannot append, device record size %d does not support %s spec", 488 rdblksz, argv0); 489 return(-1); 490 } 491 492 /* 493 * ar_read() 494 * read up to a specified number of bytes from the archive into the 495 * supplied buffer. When dealing with tapes we may not always be able to 496 * read what we want. 497 * Return: 498 * Number of bytes in buffer. 0 for end of file, -1 for a read error. 499 */ 500 501 int 502 ar_read(char *buf, int cnt) 503 { 504 int res = 0; 505 506 /* 507 * if last i/o was in error, no more reads until reset or new volume 508 */ 509 if (lstrval <= 0) 510 return(lstrval); 511 512 /* 513 * how we read must be based on device type 514 */ 515 switch (artyp) { 516 case ISTAPE: 517 if ((res = read(arfd, buf, cnt)) > 0) { 518 /* 519 * CAUTION: tape systems may not always return the same 520 * sized records so we leave blksz == MAXBLK. The 521 * physical record size that a tape drive supports is 522 * very hard to determine in a uniform and portable 523 * manner. 524 */ 525 io_ok = 1; 526 if (res != rdblksz) { 527 /* 528 * Record size changed. If this happens on 529 * any record after the first, we probably have 530 * a tape drive which has a fixed record size 531 * (we are getting multiple records in a single 532 * read). Watch out for record blocking that 533 * violates pax spec (must be a multiple of 534 * BLKMULT). 535 */ 536 rdblksz = res; 537 if (rdblksz % BLKMULT) 538 invld_rec = 1; 539 } 540 return(res); 541 } 542 break; 543 case ISREG: 544 case ISBLK: 545 case ISCHR: 546 case ISPIPE: 547 default: 548 /* 549 * Files are so easy to deal with. These other things cannot 550 * be trusted at all. So when we are dealing with character 551 * devices and pipes we just take what they have ready for us 552 * and return. Trying to do anything else with them runs the 553 * risk of failure. 554 */ 555 if ((res = read(arfd, buf, cnt)) > 0) { 556 io_ok = 1; 557 return(res); 558 } 559 break; 560 } 561 562 /* 563 * We are in trouble at this point, something is broken... 564 */ 565 lstrval = res; 566 if (res < 0) 567 syswarn(1, errno, "Failed read on archive volume %d", arvol); 568 else 569 paxwarn(0, "End of archive volume %d reached", arvol); 570 return(res); 571 } 572 573 /* 574 * ar_write() 575 * Write a specified number of bytes in supplied buffer to the archive 576 * device so it appears as a single "block". Deals with errors and tries 577 * to recover when faced with short writes. 578 * Return: 579 * Number of bytes written. 0 indicates end of volume reached and with no 580 * flaws (as best that can be detected). A -1 indicates an unrecoverable 581 * error in the archive occurred. 582 */ 583 584 int 585 ar_write(char *buf, int bsz) 586 { 587 int res; 588 off_t cpos; 589 590 /* 591 * do not allow pax to create a "bad" archive. Once a write fails on 592 * an archive volume prevent further writes to it. 593 */ 594 if (lstrval <= 0) 595 return(lstrval); 596 597 if ((res = write(arfd, buf, bsz)) == bsz) { 598 wr_trail = 1; 599 io_ok = 1; 600 return(bsz); 601 } 602 /* 603 * write broke, see what we can do with it. We try to send any partial 604 * writes that may violate pax spec to the next archive volume. 605 */ 606 if (res < 0) 607 lstrval = res; 608 else 609 lstrval = 0; 610 611 switch (artyp) { 612 case ISREG: 613 if ((res > 0) && (res % BLKMULT)) { 614 /* 615 * try to fix up partial writes which are not BLKMULT 616 * in size by forcing the runt record to next archive 617 * volume 618 */ 619 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 620 break; 621 cpos -= (off_t)res; 622 if (ftruncate(arfd, cpos) < 0) 623 break; 624 res = lstrval = 0; 625 break; 626 } 627 if (res >= 0) 628 break; 629 /* 630 * if file is out of space, handle it like a return of 0 631 */ 632 if ((errno == ENOSPC) || (errno == EFBIG) || (errno == EDQUOT)) 633 res = lstrval = 0; 634 break; 635 case ISTAPE: 636 case ISCHR: 637 case ISBLK: 638 if (res >= 0) 639 break; 640 if (errno == EACCES) { 641 paxwarn(0, "Write failed, archive is write protected."); 642 res = lstrval = 0; 643 return(0); 644 } 645 /* 646 * see if we reached the end of media, if so force a change to 647 * the next volume 648 */ 649 if ((errno == ENOSPC) || (errno == EIO) || (errno == ENXIO)) 650 res = lstrval = 0; 651 break; 652 case ISPIPE: 653 default: 654 /* 655 * we cannot fix errors to these devices 656 */ 657 break; 658 } 659 660 /* 661 * Better tell the user the bad news... 662 * if this is a block aligned archive format, we may have a bad archive 663 * if the format wants the header to start at a BLKMULT boundary. While 664 * we can deal with the mis-aligned data, it violates spec and other 665 * archive readers will likely fail. If the format is not block 666 * aligned, the user may be lucky (and the archive is ok). 667 */ 668 if (res >= 0) { 669 if (res > 0) 670 wr_trail = 1; 671 io_ok = 1; 672 } 673 674 /* 675 * If we were trying to rewrite the trailer and it didn't work, we 676 * must quit right away. 677 */ 678 if (!wr_trail && (res <= 0)) { 679 paxwarn(1,"Unable to append, trailer re-write failed. Quitting."); 680 return(res); 681 } 682 683 if (res == 0) 684 paxwarn(0, "End of archive volume %d reached", arvol); 685 else if (res < 0) 686 syswarn(1, errno, "Failed write to archive volume: %d", arvol); 687 else if (!frmt->blkalgn || ((res % frmt->blkalgn) == 0)) 688 paxwarn(0,"WARNING: partial archive write. Archive MAY BE FLAWED"); 689 else 690 paxwarn(1,"WARNING: partial archive write. Archive IS FLAWED"); 691 return(res); 692 } 693 694 /* 695 * ar_rdsync() 696 * Try to move past a bad spot on a flawed archive as needed to continue 697 * I/O. Clears error flags to allow I/O to continue. 698 * Return: 699 * 0 when ok to try i/o again, -1 otherwise. 700 */ 701 702 int 703 ar_rdsync(void) 704 { 705 long fsbz; 706 off_t cpos; 707 off_t mpos; 708 struct mtop mb; 709 710 /* 711 * Fail resync attempts at user request (done) or if this is going to be 712 * an update/append to an existing archive. If last i/o hit media end, 713 * we need to go to the next volume not try a resync. 714 */ 715 if ((done > 0) || (lstrval == 0)) 716 return(-1); 717 718 if ((act == APPND) || (act == ARCHIVE)) { 719 paxwarn(1, "Cannot allow updates to an archive with flaws."); 720 return(-1); 721 } 722 if (io_ok) 723 did_io = 1; 724 725 switch(artyp) { 726 case ISTAPE: 727 /* 728 * if the last i/o was a successful data transfer, we assume 729 * the fault is just a bad record on the tape that we are now 730 * past. If we did not get any data since the last resync try 731 * to move the tape forward one PHYSICAL record past any 732 * damaged tape section. Some tape drives are stubborn and need 733 * to be pushed. 734 */ 735 if (io_ok) { 736 io_ok = 0; 737 lstrval = 1; 738 break; 739 } 740 mb.mt_op = MTFSR; 741 mb.mt_count = 1; 742 if (ioctl(arfd, MTIOCTOP, &mb) < 0) 743 break; 744 lstrval = 1; 745 break; 746 case ISREG: 747 case ISCHR: 748 case ISBLK: 749 /* 750 * try to step over the bad part of the device. 751 */ 752 io_ok = 0; 753 if (((fsbz = arsb.st_blksize) <= 0) || (artyp != ISREG)) 754 fsbz = BLKMULT; 755 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 756 break; 757 mpos = fsbz - (cpos % (off_t)fsbz); 758 if (lseek(arfd, mpos, SEEK_CUR) < 0) 759 break; 760 lstrval = 1; 761 break; 762 case ISPIPE: 763 default: 764 /* 765 * cannot recover on these archive device types 766 */ 767 io_ok = 0; 768 break; 769 } 770 if (lstrval <= 0) { 771 paxwarn(1, "Unable to recover from an archive read failure."); 772 return(-1); 773 } 774 paxwarn(0, "Attempting to recover from an archive read failure."); 775 return(0); 776 } 777 778 /* 779 * ar_fow() 780 * Move the I/O position within the archive forward the specified number of 781 * bytes as supported by the device. If we cannot move the requested 782 * number of bytes, return the actual number of bytes moved in skipped. 783 * Return: 784 * 0 if moved the requested distance, -1 on complete failure, 1 on 785 * partial move (the amount moved is in skipped) 786 */ 787 788 int 789 ar_fow(off_t sksz, off_t *skipped) 790 { 791 off_t cpos; 792 off_t mpos; 793 794 *skipped = 0; 795 if (sksz <= 0) 796 return(0); 797 798 /* 799 * we cannot move forward at EOF or error 800 */ 801 if (lstrval <= 0) 802 return(lstrval); 803 804 /* 805 * Safer to read forward on devices where it is hard to find the end of 806 * the media without reading to it. With tapes we cannot be sure of the 807 * number of physical blocks to skip (we do not know physical block 808 * size at this point), so we must only read forward on tapes! 809 */ 810 if (artyp != ISREG) 811 return(0); 812 813 /* 814 * figure out where we are in the archive 815 */ 816 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) >= 0) { 817 /* 818 * we can be asked to move farther than there are bytes in this 819 * volume, if so, just go to file end and let normal buf_fill() 820 * deal with the end of file (it will go to next volume by 821 * itself) 822 */ 823 if ((mpos = cpos + sksz) > arsb.st_size) { 824 *skipped = arsb.st_size - cpos; 825 mpos = arsb.st_size; 826 } else 827 *skipped = sksz; 828 if (lseek(arfd, mpos, SEEK_SET) >= 0) 829 return(0); 830 } 831 syswarn(1, errno, "Forward positioning operation on archive failed"); 832 lstrval = -1; 833 return(-1); 834 } 835 836 /* 837 * ar_rev() 838 * move the i/o position within the archive backwards the specified byte 839 * count as supported by the device. With tapes drives we RESET rdblksz to 840 * the PHYSICAL blocksize. 841 * NOTE: We should only be called to move backwards so we can rewrite the 842 * last records (the trailer) of an archive (APPEND). 843 * Return: 844 * 0 if moved the requested distance, -1 on complete failure 845 */ 846 847 int 848 ar_rev(off_t sksz) 849 { 850 off_t cpos; 851 struct mtop mb; 852 int phyblk; 853 854 /* 855 * make sure we do not have try to reverse on a flawed archive 856 */ 857 if (lstrval < 0) 858 return(lstrval); 859 860 switch(artyp) { 861 case ISPIPE: 862 if (sksz <= 0) 863 break; 864 /* 865 * cannot go backwards on these critters 866 */ 867 paxwarn(1, "Reverse positioning on pipes is not supported."); 868 lstrval = -1; 869 return(-1); 870 case ISREG: 871 case ISBLK: 872 case ISCHR: 873 default: 874 if (sksz <= 0) 875 break; 876 877 /* 878 * For things other than files, backwards movement has a very 879 * high probability of failure as we really do not know the 880 * true attributes of the device we are talking to (the device 881 * may not even have the ability to lseek() in any direction). 882 * First we figure out where we are in the archive. 883 */ 884 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) { 885 syswarn(1, errno, 886 "Unable to obtain current archive byte offset"); 887 lstrval = -1; 888 return(-1); 889 } 890 891 /* 892 * we may try to go backwards past the start when the archive 893 * is only a single record. If this happens and we are on a 894 * multi volume archive, we need to go to the end of the 895 * previous volume and continue our movement backwards from 896 * there. 897 */ 898 if ((cpos -= sksz) < (off_t)0L) { 899 if (arvol > 1) { 900 /* 901 * this should never happen 902 */ 903 paxwarn(1,"Reverse position on previous volume."); 904 lstrval = -1; 905 return(-1); 906 } 907 cpos = (off_t)0L; 908 } 909 if (lseek(arfd, cpos, SEEK_SET) < 0) { 910 syswarn(1, errno, "Unable to seek archive backwards"); 911 lstrval = -1; 912 return(-1); 913 } 914 break; 915 case ISTAPE: 916 /* 917 * Calculate and move the proper number of PHYSICAL tape 918 * blocks. If the sksz is not an even multiple of the physical 919 * tape size, we cannot do the move (this should never happen). 920 * (We also cannot handle trailers spread over two vols). 921 * get_phys() also makes sure we are in front of the filemark. 922 */ 923 if ((phyblk = get_phys()) <= 0) { 924 lstrval = -1; 925 return(-1); 926 } 927 928 /* 929 * make sure future tape reads only go by physical tape block 930 * size (set rdblksz to the real size). 931 */ 932 rdblksz = phyblk; 933 934 /* 935 * if no movement is required, just return (we must be after 936 * get_phys() so the physical blocksize is properly set) 937 */ 938 if (sksz <= 0) 939 break; 940 941 /* 942 * ok we have to move. Make sure the tape drive can do it. 943 */ 944 if (sksz % phyblk) { 945 paxwarn(1, 946 "Tape drive unable to backspace requested amount"); 947 lstrval = -1; 948 return(-1); 949 } 950 951 /* 952 * move backwards the requested number of bytes 953 */ 954 mb.mt_op = MTBSR; 955 mb.mt_count = sksz/phyblk; 956 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 957 syswarn(1,errno, "Unable to backspace tape %d blocks.", 958 mb.mt_count); 959 lstrval = -1; 960 return(-1); 961 } 962 break; 963 } 964 lstrval = 1; 965 return(0); 966 } 967 968 /* 969 * get_phys() 970 * Determine the physical block size on a tape drive. We need the physical 971 * block size so we know how many bytes we skip over when we move with 972 * mtio commands. We also make sure we are BEFORE THE TAPE FILEMARK when 973 * return. 974 * This is one really SLOW routine... 975 * Return: 976 * physical block size if ok (ok > 0), -1 otherwise 977 */ 978 979 static int 980 get_phys(void) 981 { 982 int padsz = 0; 983 int res; 984 int phyblk; 985 struct mtop mb; 986 char scbuf[MAXBLK]; 987 988 /* 989 * move to the file mark, and then back up one record and read it. 990 * this should tell us the physical record size the tape is using. 991 */ 992 if (lstrval == 1) { 993 /* 994 * we know we are at file mark when we get back a 0 from 995 * read() 996 */ 997 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 998 padsz += res; 999 if (res < 0) { 1000 syswarn(1, errno, "Unable to locate tape filemark."); 1001 return(-1); 1002 } 1003 } 1004 1005 /* 1006 * move backwards over the file mark so we are at the end of the 1007 * last record. 1008 */ 1009 mb.mt_op = MTBSF; 1010 mb.mt_count = 1; 1011 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1012 syswarn(1, errno, "Unable to backspace over tape filemark."); 1013 return(-1); 1014 } 1015 1016 /* 1017 * move backwards so we are in front of the last record and read it to 1018 * get physical tape blocksize. 1019 */ 1020 mb.mt_op = MTBSR; 1021 mb.mt_count = 1; 1022 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1023 syswarn(1, errno, "Unable to backspace over last tape block."); 1024 return(-1); 1025 } 1026 if ((phyblk = read(arfd, scbuf, sizeof(scbuf))) <= 0) { 1027 syswarn(1, errno, "Cannot determine archive tape blocksize."); 1028 return(-1); 1029 } 1030 1031 /* 1032 * read forward to the file mark, then back up in front of the filemark 1033 * (this is a bit paranoid, but should be safe to do). 1034 */ 1035 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1036 ; 1037 if (res < 0) { 1038 syswarn(1, errno, "Unable to locate tape filemark."); 1039 return(-1); 1040 } 1041 mb.mt_op = MTBSF; 1042 mb.mt_count = 1; 1043 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1044 syswarn(1, errno, "Unable to backspace over tape filemark."); 1045 return(-1); 1046 } 1047 1048 /* 1049 * set lstrval so we know that the filemark has not been seen 1050 */ 1051 lstrval = 1; 1052 1053 /* 1054 * return if there was no padding 1055 */ 1056 if (padsz == 0) 1057 return(phyblk); 1058 1059 /* 1060 * make sure we can move backwards over the padding. (this should 1061 * never fail). 1062 */ 1063 if (padsz % phyblk) { 1064 paxwarn(1, "Tape drive unable to backspace requested amount"); 1065 return(-1); 1066 } 1067 1068 /* 1069 * move backwards over the padding so the head is where it was when 1070 * we were first called (if required). 1071 */ 1072 mb.mt_op = MTBSR; 1073 mb.mt_count = padsz/phyblk; 1074 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1075 syswarn(1,errno,"Unable to backspace tape over %d pad blocks", 1076 mb.mt_count); 1077 return(-1); 1078 } 1079 return(phyblk); 1080 } 1081 1082 /* 1083 * ar_next() 1084 * prompts the user for the next volume in this archive. For some devices 1085 * we may allow the media to be changed. Otherwise a new archive is 1086 * prompted for. By pax spec, if there is no controlling tty or an eof is 1087 * read on tty input, we must quit pax. 1088 * Return: 1089 * 0 when ready to continue, -1 when all done 1090 */ 1091 1092 int 1093 ar_next(void) 1094 { 1095 static char *arcbuf; 1096 char buf[PAXPATHLEN+2]; 1097 sigset_t o_mask; 1098 1099 /* 1100 * WE MUST CLOSE THE DEVICE. A lot of devices must see last close, (so 1101 * things like writing EOF etc will be done) (Watch out ar_close() can 1102 * also be called via a signal handler, so we must prevent a race. 1103 */ 1104 if (sigprocmask(SIG_BLOCK, &s_mask, &o_mask) < 0) 1105 syswarn(0, errno, "Unable to set signal mask"); 1106 ar_close(); 1107 if (sigprocmask(SIG_SETMASK, &o_mask, NULL) < 0) 1108 syswarn(0, errno, "Unable to restore signal mask"); 1109 1110 if (done || !wr_trail || Oflag || strcmp(NM_TAR, argv0) == 0) 1111 return(-1); 1112 1113 tty_prnt("\nATTENTION! %s archive volume change required.\n", argv0); 1114 1115 /* 1116 * if i/o is on stdin or stdout, we cannot reopen it (we do not know 1117 * the name), the user will be forced to type it in. 1118 */ 1119 if (strcmp(arcname, stdo) && strcmp(arcname, stdn) && (artyp != ISREG) 1120 && (artyp != ISPIPE)) { 1121 if (artyp == ISTAPE) { 1122 tty_prnt("%s ready for archive tape volume: %d\n", 1123 arcname, arvol); 1124 tty_prnt("Load the NEXT TAPE on the tape drive"); 1125 } else { 1126 tty_prnt("%s ready for archive volume: %d\n", 1127 arcname, arvol); 1128 tty_prnt("Load the NEXT STORAGE MEDIA (if required)"); 1129 } 1130 1131 if ((act == ARCHIVE) || (act == APPND)) 1132 tty_prnt(" and make sure it is WRITE ENABLED.\n"); 1133 else 1134 tty_prnt("\n"); 1135 1136 for(;;) { 1137 tty_prnt("Type \"y\" to continue, \".\" to quit %s,", 1138 argv0); 1139 tty_prnt(" or \"s\" to switch to new device.\nIf you"); 1140 tty_prnt(" cannot change storage media, type \"s\"\n"); 1141 tty_prnt("Is the device ready and online? > "); 1142 1143 if ((tty_read(buf,sizeof(buf))<0) || !strcmp(buf,".")){ 1144 done = 1; 1145 lstrval = -1; 1146 tty_prnt("Quitting %s!\n", argv0); 1147 vfpart = 0; 1148 return(-1); 1149 } 1150 1151 if ((buf[0] == '\0') || (buf[1] != '\0')) { 1152 tty_prnt("%s unknown command, try again\n",buf); 1153 continue; 1154 } 1155 1156 switch (buf[0]) { 1157 case 'y': 1158 case 'Y': 1159 /* 1160 * we are to continue with the same device 1161 */ 1162 if (ar_open(arcname) >= 0) 1163 return(0); 1164 tty_prnt("Cannot re-open %s, try again\n", 1165 arcname); 1166 continue; 1167 case 's': 1168 case 'S': 1169 /* 1170 * user wants to open a different device 1171 */ 1172 tty_prnt("Switching to a different archive\n"); 1173 break; 1174 default: 1175 tty_prnt("%s unknown command, try again\n",buf); 1176 continue; 1177 } 1178 break; 1179 } 1180 } else 1181 tty_prnt("Ready for archive volume: %d\n", arvol); 1182 1183 /* 1184 * have to go to a different archive 1185 */ 1186 for (;;) { 1187 tty_prnt("Input archive name or \".\" to quit %s.\n", argv0); 1188 tty_prnt("Archive name > "); 1189 1190 if ((tty_read(buf, sizeof(buf)) < 0) || !strcmp(buf, ".")) { 1191 done = 1; 1192 lstrval = -1; 1193 tty_prnt("Quitting %s!\n", argv0); 1194 vfpart = 0; 1195 return(-1); 1196 } 1197 if (buf[0] == '\0') { 1198 tty_prnt("Empty file name, try again\n"); 1199 continue; 1200 } 1201 if (!strcmp(buf, "..")) { 1202 tty_prnt("Illegal file name: .. try again\n"); 1203 continue; 1204 } 1205 if (strlen(buf) > PAXPATHLEN) { 1206 tty_prnt("File name too long, try again\n"); 1207 continue; 1208 } 1209 1210 /* 1211 * try to open new archive 1212 */ 1213 if (ar_open(buf) >= 0) { 1214 free(arcbuf); 1215 if ((arcbuf = strdup(buf)) == NULL) { 1216 done = 1; 1217 lstrval = -1; 1218 paxwarn(0, "Cannot save archive name."); 1219 return(-1); 1220 } 1221 arcname = arcbuf; 1222 break; 1223 } 1224 tty_prnt("Cannot open %s, try again\n", buf); 1225 continue; 1226 } 1227 return(0); 1228 } 1229 1230 /* 1231 * ar_start_gzip() 1232 * starts the gzip compression/decompression process as a child, using magic 1233 * to keep the fd the same in the calling function (parent). 1234 */ 1235 void 1236 ar_start_gzip(int fd, const char *gzip_prog, int wr) 1237 { 1238 int fds[2]; 1239 const char *gzip_flags; 1240 1241 if (pipe(fds) < 0) 1242 err(1, "could not pipe"); 1243 zpid = fork(); 1244 if (zpid < 0) 1245 err(1, "could not fork"); 1246 1247 /* parent */ 1248 if (zpid) { 1249 if (wr) 1250 dup2(fds[1], fd); 1251 else 1252 dup2(fds[0], fd); 1253 close(fds[0]); 1254 close(fds[1]); 1255 } else { 1256 if (wr) { 1257 dup2(fds[0], STDIN_FILENO); 1258 dup2(fd, STDOUT_FILENO); 1259 gzip_flags = "-c"; 1260 } else { 1261 dup2(fds[1], STDOUT_FILENO); 1262 dup2(fd, STDIN_FILENO); 1263 gzip_flags = "-dc"; 1264 } 1265 close(fds[0]); 1266 close(fds[1]); 1267 if (execlp(gzip_prog, gzip_prog, gzip_flags, 1268 (char *)NULL) < 0) 1269 err(1, "could not exec"); 1270 /* NOTREACHED */ 1271 } 1272 } 1273