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 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)ar_io.c 8.2 (Berkeley) 4/18/94"; 39 #endif 40 #endif /* not lint */ 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <sys/types.h> 45 #include <sys/ioctl.h> 46 #include <sys/mtio.h> 47 #include <sys/stat.h> 48 #include <sys/wait.h> 49 #include <err.h> 50 #include <errno.h> 51 #include <fcntl.h> 52 #include <signal.h> 53 #include <stdint.h> 54 #include <stdio.h> 55 #include <string.h> 56 #include <stdlib.h> 57 #include <unistd.h> 58 #include "pax.h" 59 #include "options.h" 60 #include "extern.h" 61 62 /* 63 * Routines which deal directly with the archive I/O device/file. 64 */ 65 66 #define DMOD 0666 /* default mode of created archives */ 67 #define EXT_MODE O_RDONLY /* open mode for list/extract */ 68 #define AR_MODE (O_WRONLY | O_CREAT | O_TRUNC) /* mode for archive */ 69 #define APP_MODE O_RDWR /* mode for append */ 70 71 static char none[] = "<NONE>"; /* pseudo name for no file */ 72 static char stdo[] = "<STDOUT>"; /* pseudo name for stdout */ 73 static char stdn[] = "<STDIN>"; /* pseudo name for stdin */ 74 static int arfd = -1; /* archive file descriptor */ 75 static int artyp = ISREG; /* archive type: file/FIFO/tape */ 76 static int arvol = 1; /* archive volume number */ 77 static int lstrval = -1; /* return value from last i/o */ 78 static int io_ok; /* i/o worked on volume after resync */ 79 static int did_io; /* did i/o ever occur on volume? */ 80 static int done; /* set via tty termination */ 81 static struct stat arsb; /* stat of archive device at open */ 82 static int invld_rec; /* tape has out of spec record size */ 83 static int wr_trail = 1; /* trailer was rewritten in append */ 84 static int can_unlnk = 0; /* do we unlink null archives? */ 85 const char *arcname; /* printable name of archive */ 86 const char *gzip_program; /* name of gzip program */ 87 static pid_t zpid = -1; /* pid of child process */ 88 89 static int get_phys(void); 90 static void ar_start_gzip(int, const char *, int); 91 92 /* 93 * ar_open() 94 * Opens the next archive volume. Determines the type of the device and 95 * sets up block sizes as required by the archive device and the format. 96 * Note: we may be called with name == NULL on the first open only. 97 * Return: 98 * -1 on failure, 0 otherwise 99 */ 100 101 int 102 ar_open(const char *name) 103 { 104 struct mtget mb; 105 106 if (arfd != -1) 107 (void)close(arfd); 108 arfd = -1; 109 can_unlnk = did_io = io_ok = invld_rec = 0; 110 artyp = ISREG; 111 flcnt = 0; 112 113 /* 114 * open based on overall operation mode 115 */ 116 switch (act) { 117 case LIST: 118 case EXTRACT: 119 if (name == NULL) { 120 arfd = STDIN_FILENO; 121 arcname = stdn; 122 } else if ((arfd = open(name, EXT_MODE, DMOD)) < 0) 123 syswarn(0, errno, "Failed open to read on %s", name); 124 if (arfd != -1 && gzip_program != NULL) 125 ar_start_gzip(arfd, gzip_program, 0); 126 break; 127 case ARCHIVE: 128 if (name == NULL) { 129 arfd = STDOUT_FILENO; 130 arcname = stdo; 131 } else if ((arfd = open(name, AR_MODE, DMOD)) < 0) 132 syswarn(0, errno, "Failed open to write on %s", name); 133 else 134 can_unlnk = 1; 135 if (arfd != -1 && gzip_program != NULL) 136 ar_start_gzip(arfd, gzip_program, 1); 137 break; 138 case APPND: 139 if (name == NULL) { 140 arfd = STDOUT_FILENO; 141 arcname = stdo; 142 } else if ((arfd = open(name, APP_MODE, DMOD)) < 0) 143 syswarn(0, errno, "Failed open to read/write on %s", 144 name); 145 break; 146 case COPY: 147 /* 148 * arfd not used in COPY mode 149 */ 150 arcname = none; 151 lstrval = 1; 152 return(0); 153 } 154 if (arfd < 0) 155 return(-1); 156 157 if (chdname != NULL) 158 if (chdir(chdname) != 0) { 159 syswarn(1, errno, "Failed chdir to %s", chdname); 160 return(-1); 161 } 162 /* 163 * set up is based on device type 164 */ 165 if (fstat(arfd, &arsb) < 0) { 166 syswarn(0, errno, "Failed stat on %s", arcname); 167 (void)close(arfd); 168 arfd = -1; 169 can_unlnk = 0; 170 return(-1); 171 } 172 if (S_ISDIR(arsb.st_mode)) { 173 paxwarn(0, "Cannot write an archive on top of a directory %s", 174 arcname); 175 (void)close(arfd); 176 arfd = -1; 177 can_unlnk = 0; 178 return(-1); 179 } 180 181 if (S_ISCHR(arsb.st_mode)) 182 artyp = ioctl(arfd, MTIOCGET, &mb) ? ISCHR : ISTAPE; 183 else if (S_ISBLK(arsb.st_mode)) 184 artyp = ISBLK; 185 else if ((lseek(arfd, (off_t)0L, SEEK_CUR) == -1) && (errno == ESPIPE)) 186 artyp = ISPIPE; 187 else 188 artyp = ISREG; 189 190 /* 191 * make sure we beyond any doubt that we only can unlink regular files 192 * we created 193 */ 194 if (artyp != ISREG) 195 can_unlnk = 0; 196 /* 197 * if we are writing, we are done 198 */ 199 if (act == ARCHIVE) { 200 blksz = rdblksz = wrblksz; 201 lstrval = 1; 202 return(0); 203 } 204 205 /* 206 * set default blksz on read. APPNDs writes rdblksz on the last volume 207 * On all new archive volumes, we shift to wrblksz (if the user 208 * specified one, otherwise we will continue to use rdblksz). We 209 * must to set blocksize based on what kind of device the archive is 210 * stored. 211 */ 212 switch(artyp) { 213 case ISTAPE: 214 /* 215 * Tape drives come in at least two flavors. Those that support 216 * variable sized records and those that have fixed sized 217 * records. They must be treated differently. For tape drives 218 * that support variable sized records, we must make large 219 * reads to make sure we get the entire record, otherwise we 220 * will just get the first part of the record (up to size we 221 * asked). Tapes with fixed sized records may or may not return 222 * multiple records in a single read. We really do not care 223 * what the physical record size is UNLESS we are going to 224 * append. (We will need the physical block size to rewrite 225 * the trailer). Only when we are appending do we go to the 226 * effort to figure out the true PHYSICAL record size. 227 */ 228 blksz = rdblksz = MAXBLK; 229 break; 230 case ISPIPE: 231 case ISBLK: 232 case ISCHR: 233 /* 234 * Blocksize is not a major issue with these devices (but must 235 * be kept a multiple of 512). If the user specified a write 236 * block size, we use that to read. Under append, we must 237 * always keep blksz == rdblksz. Otherwise we go ahead and use 238 * the device optimal blocksize as (and if) returned by stat 239 * and if it is within pax specs. 240 */ 241 if ((act == APPND) && wrblksz) { 242 blksz = rdblksz = wrblksz; 243 break; 244 } 245 246 if ((arsb.st_blksize > 0) && (arsb.st_blksize < MAXBLK) && 247 ((arsb.st_blksize % BLKMULT) == 0)) 248 rdblksz = arsb.st_blksize; 249 else 250 rdblksz = DEVBLK; 251 /* 252 * For performance go for large reads when we can without harm 253 */ 254 if ((act == APPND) || (artyp == ISCHR)) 255 blksz = rdblksz; 256 else 257 blksz = MAXBLK; 258 break; 259 case ISREG: 260 /* 261 * if the user specified wrblksz works, use it. Under appends 262 * we must always keep blksz == rdblksz 263 */ 264 if ((act == APPND) && wrblksz && ((arsb.st_size%wrblksz)==0)){ 265 blksz = rdblksz = wrblksz; 266 break; 267 } 268 /* 269 * See if we can find the blocking factor from the file size 270 */ 271 for (rdblksz = MAXBLK; rdblksz > 0; rdblksz -= BLKMULT) 272 if ((arsb.st_size % rdblksz) == 0) 273 break; 274 /* 275 * When we cannot find a match, we may have a flawed archive. 276 */ 277 if (rdblksz <= 0) 278 rdblksz = FILEBLK; 279 /* 280 * for performance go for large reads when we can 281 */ 282 if (act == APPND) 283 blksz = rdblksz; 284 else 285 blksz = MAXBLK; 286 break; 287 default: 288 /* 289 * should never happen, worse case, slow... 290 */ 291 blksz = rdblksz = BLKMULT; 292 break; 293 } 294 lstrval = 1; 295 return(0); 296 } 297 298 /* 299 * ar_close() 300 * closes archive device, increments volume number, and prints i/o summary 301 */ 302 void 303 ar_close(void) 304 { 305 int status; 306 307 if (arfd < 0) { 308 did_io = io_ok = flcnt = 0; 309 return; 310 } 311 312 /* 313 * Close archive file. This may take a LONG while on tapes (we may be 314 * forced to wait for the rewind to complete) so tell the user what is 315 * going on (this avoids the user hitting control-c thinking pax is 316 * broken). 317 */ 318 if (vflag && (artyp == ISTAPE)) { 319 if (vfpart) 320 (void)putc('\n', listf); 321 (void)fprintf(listf, 322 "%s: Waiting for tape drive close to complete...", 323 argv0); 324 (void)fflush(listf); 325 } 326 327 /* 328 * if nothing was written to the archive (and we created it), we remove 329 * it 330 */ 331 if (can_unlnk && (fstat(arfd, &arsb) == 0) && (S_ISREG(arsb.st_mode)) && 332 (arsb.st_size == 0)) { 333 (void)unlink(arcname); 334 can_unlnk = 0; 335 } 336 337 /* 338 * for a quick extract/list, pax frequently exits before the child 339 * process is done 340 */ 341 if ((act == LIST || act == EXTRACT) && nflag && zpid > 0) 342 kill(zpid, SIGINT); 343 344 (void)close(arfd); 345 346 /* Do not exit before child to ensure data integrity */ 347 if (zpid > 0) 348 waitpid(zpid, &status, 0); 349 350 if (vflag && (artyp == ISTAPE)) { 351 (void)fputs("done.\n", listf); 352 vfpart = 0; 353 (void)fflush(listf); 354 } 355 arfd = -1; 356 357 if (!io_ok && !did_io) { 358 flcnt = 0; 359 return; 360 } 361 did_io = io_ok = 0; 362 363 /* 364 * The volume number is only increased when the last device has data 365 * and we have already determined the archive format. 366 */ 367 if (frmt != NULL) 368 ++arvol; 369 370 if (!vflag) { 371 flcnt = 0; 372 return; 373 } 374 375 /* 376 * Print out a summary of I/O for this archive volume. 377 */ 378 if (vfpart) { 379 (void)putc('\n', listf); 380 vfpart = 0; 381 } 382 383 /* 384 * If we have not determined the format yet, we just say how many bytes 385 * we have skipped over looking for a header to id. There is no way we 386 * could have written anything yet. 387 */ 388 if (frmt == NULL) { 389 # ifdef NET2_STAT 390 (void)fprintf(listf, "%s: unknown format, %lu bytes skipped.\n", 391 argv0, rdcnt); 392 # else 393 (void)fprintf(listf, "%s: unknown format, %ju bytes skipped.\n", 394 argv0, (uintmax_t)rdcnt); 395 # endif 396 (void)fflush(listf); 397 flcnt = 0; 398 return; 399 } 400 401 if (strcmp(NM_CPIO, argv0) == 0) 402 (void)fprintf(listf, "%llu blocks\n", 403 (unsigned long long)((rdcnt ? rdcnt : wrcnt) / 5120)); 404 else if (strcmp(NM_TAR, argv0) != 0) 405 (void)fprintf(listf, 406 # ifdef NET2_STAT 407 "%s: %s vol %d, %lu files, %lu bytes read, %lu bytes written.\n", 408 argv0, frmt->name, arvol-1, flcnt, rdcnt, wrcnt); 409 # else 410 "%s: %s vol %d, %ju files, %ju bytes read, %ju bytes written.\n", 411 argv0, frmt->name, arvol-1, (uintmax_t)flcnt, 412 (uintmax_t)rdcnt, (uintmax_t)wrcnt); 413 # endif 414 (void)fflush(listf); 415 flcnt = 0; 416 } 417 418 /* 419 * ar_drain() 420 * drain any archive format independent padding from an archive read 421 * from a socket or a pipe. This is to prevent the process on the 422 * other side of the pipe from getting a SIGPIPE (pax will stop 423 * reading an archive once a format dependent trailer is detected). 424 */ 425 void 426 ar_drain(void) 427 { 428 int res; 429 char drbuf[MAXBLK]; 430 431 /* 432 * we only drain from a pipe/socket. Other devices can be closed 433 * without reading up to end of file. We sure hope that pipe is closed 434 * on the other side so we will get an EOF. 435 */ 436 if ((artyp != ISPIPE) || (lstrval <= 0)) 437 return; 438 439 /* 440 * keep reading until pipe is drained 441 */ 442 while ((res = read(arfd, drbuf, sizeof(drbuf))) > 0) 443 ; 444 lstrval = res; 445 } 446 447 /* 448 * ar_set_wr() 449 * Set up device right before switching from read to write in an append. 450 * device dependent code (if required) to do this should be added here. 451 * For all archive devices we are already positioned at the place we want 452 * to start writing when this routine is called. 453 * Return: 454 * 0 if all ready to write, -1 otherwise 455 */ 456 457 int 458 ar_set_wr(void) 459 { 460 off_t cpos; 461 462 /* 463 * we must make sure the trailer is rewritten on append, ar_next() 464 * will stop us if the archive containing the trailer was not written 465 */ 466 wr_trail = 0; 467 468 /* 469 * Add any device dependent code as required here 470 */ 471 if (artyp != ISREG) 472 return(0); 473 /* 474 * Ok we have an archive in a regular file. If we were rewriting a 475 * file, we must get rid of all the stuff after the current offset 476 * (it was not written by pax). 477 */ 478 if (((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) || 479 (ftruncate(arfd, cpos) < 0)) { 480 syswarn(1, errno, "Unable to truncate archive file"); 481 return(-1); 482 } 483 return(0); 484 } 485 486 /* 487 * ar_app_ok() 488 * check if the last volume in the archive allows appends. We cannot check 489 * this until we are ready to write since there is no spec that says all 490 * volumes in a single archive have to be of the same type... 491 * Return: 492 * 0 if we can append, -1 otherwise. 493 */ 494 495 int 496 ar_app_ok(void) 497 { 498 if (artyp == ISPIPE) { 499 paxwarn(1, "Cannot append to an archive obtained from a pipe."); 500 return(-1); 501 } 502 503 if (!invld_rec) 504 return(0); 505 paxwarn(1,"Cannot append, device record size %d does not support %s spec", 506 rdblksz, argv0); 507 return(-1); 508 } 509 510 /* 511 * ar_read() 512 * read up to a specified number of bytes from the archive into the 513 * supplied buffer. When dealing with tapes we may not always be able to 514 * read what we want. 515 * Return: 516 * Number of bytes in buffer. 0 for end of file, -1 for a read error. 517 */ 518 519 int 520 ar_read(char *buf, int cnt) 521 { 522 int res = 0; 523 524 /* 525 * if last i/o was in error, no more reads until reset or new volume 526 */ 527 if (lstrval <= 0) 528 return(lstrval); 529 530 /* 531 * how we read must be based on device type 532 */ 533 switch (artyp) { 534 case ISTAPE: 535 if ((res = read(arfd, buf, cnt)) > 0) { 536 /* 537 * CAUTION: tape systems may not always return the same 538 * sized records so we leave blksz == MAXBLK. The 539 * physical record size that a tape drive supports is 540 * very hard to determine in a uniform and portable 541 * manner. 542 */ 543 io_ok = 1; 544 if (res != rdblksz) { 545 /* 546 * Record size changed. If this is happens on 547 * any record after the first, we probably have 548 * a tape drive which has a fixed record size 549 * we are getting multiple records in a single 550 * read). Watch out for record blocking that 551 * violates pax spec (must be a multiple of 552 * BLKMULT). 553 */ 554 rdblksz = res; 555 if (rdblksz % BLKMULT) 556 invld_rec = 1; 557 } 558 return(res); 559 } 560 break; 561 case ISREG: 562 case ISBLK: 563 case ISCHR: 564 case ISPIPE: 565 default: 566 /* 567 * Files are so easy to deal with. These other things cannot 568 * be trusted at all. So when we are dealing with character 569 * devices and pipes we just take what they have ready for us 570 * and return. Trying to do anything else with them runs the 571 * risk of failure. 572 */ 573 if ((res = read(arfd, buf, cnt)) > 0) { 574 io_ok = 1; 575 return(res); 576 } 577 break; 578 } 579 580 /* 581 * We are in trouble at this point, something is broken... 582 */ 583 lstrval = res; 584 if (res < 0) 585 syswarn(1, errno, "Failed read on archive volume %d", arvol); 586 else 587 paxwarn(0, "End of archive volume %d reached", arvol); 588 return(res); 589 } 590 591 /* 592 * ar_write() 593 * Write a specified number of bytes in supplied buffer to the archive 594 * device so it appears as a single "block". Deals with errors and tries 595 * to recover when faced with short writes. 596 * Return: 597 * Number of bytes written. 0 indicates end of volume reached and with no 598 * flaws (as best that can be detected). A -1 indicates an unrecoverable 599 * error in the archive occurred. 600 */ 601 602 int 603 ar_write(char *buf, int bsz) 604 { 605 int res; 606 off_t cpos; 607 608 /* 609 * do not allow pax to create a "bad" archive. Once a write fails on 610 * an archive volume prevent further writes to it. 611 */ 612 if (lstrval <= 0) 613 return(lstrval); 614 615 if ((res = write(arfd, buf, bsz)) == bsz) { 616 wr_trail = 1; 617 io_ok = 1; 618 return(bsz); 619 } 620 /* 621 * write broke, see what we can do with it. We try to send any partial 622 * writes that may violate pax spec to the next archive volume. 623 */ 624 if (res < 0) 625 lstrval = res; 626 else 627 lstrval = 0; 628 629 switch (artyp) { 630 case ISREG: 631 if ((res > 0) && (res % BLKMULT)) { 632 /* 633 * try to fix up partial writes which are not BLKMULT 634 * in size by forcing the runt record to next archive 635 * volume 636 */ 637 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 638 break; 639 cpos -= (off_t)res; 640 if (ftruncate(arfd, cpos) < 0) 641 break; 642 res = lstrval = 0; 643 break; 644 } 645 if (res >= 0) 646 break; 647 /* 648 * if file is out of space, handle it like a return of 0 649 */ 650 if ((errno == ENOSPC) || (errno == EFBIG) || (errno == EDQUOT)) 651 res = lstrval = 0; 652 break; 653 case ISTAPE: 654 case ISCHR: 655 case ISBLK: 656 if (res >= 0) 657 break; 658 if (errno == EACCES) { 659 paxwarn(0, "Write failed, archive is write protected."); 660 res = lstrval = 0; 661 return(0); 662 } 663 /* 664 * see if we reached the end of media, if so force a change to 665 * the next volume 666 */ 667 if ((errno == ENOSPC) || (errno == EIO) || (errno == ENXIO)) 668 res = lstrval = 0; 669 break; 670 case ISPIPE: 671 default: 672 /* 673 * we cannot fix errors to these devices 674 */ 675 break; 676 } 677 678 /* 679 * Better tell the user the bad news... 680 * if this is a block aligned archive format, we may have a bad archive 681 * if the format wants the header to start at a BLKMULT boundary. While 682 * we can deal with the mis-aligned data, it violates spec and other 683 * archive readers will likely fail. If the format is not block 684 * aligned, the user may be lucky (and the archive is ok). 685 */ 686 if (res >= 0) { 687 if (res > 0) 688 wr_trail = 1; 689 io_ok = 1; 690 } 691 692 /* 693 * If we were trying to rewrite the trailer and it didn't work, we 694 * must quit right away. 695 */ 696 if (!wr_trail && (res <= 0)) { 697 paxwarn(1,"Unable to append, trailer re-write failed. Quitting."); 698 return(res); 699 } 700 701 if (res == 0) 702 paxwarn(0, "End of archive volume %d reached", arvol); 703 else if (res < 0) 704 syswarn(1, errno, "Failed write to archive volume: %d", arvol); 705 else if (!frmt->blkalgn || ((res % frmt->blkalgn) == 0)) 706 paxwarn(0,"WARNING: partial archive write. Archive MAY BE FLAWED"); 707 else 708 paxwarn(1,"WARNING: partial archive write. Archive IS FLAWED"); 709 return(res); 710 } 711 712 /* 713 * ar_rdsync() 714 * Try to move past a bad spot on a flawed archive as needed to continue 715 * I/O. Clears error flags to allow I/O to continue. 716 * Return: 717 * 0 when ok to try i/o again, -1 otherwise. 718 */ 719 720 int 721 ar_rdsync(void) 722 { 723 long fsbz; 724 off_t cpos; 725 off_t mpos; 726 struct mtop mb; 727 728 /* 729 * Fail resync attempts at user request (done) or this is going to be 730 * an update/append to an existing archive. If last i/o hit media end, 731 * we need to go to the next volume not try a resync. 732 */ 733 if ((done > 0) || (lstrval == 0)) 734 return(-1); 735 736 if ((act == APPND) || (act == ARCHIVE)) { 737 paxwarn(1, "Cannot allow updates to an archive with flaws."); 738 return(-1); 739 } 740 if (io_ok) 741 did_io = 1; 742 743 switch(artyp) { 744 case ISTAPE: 745 /* 746 * if the last i/o was a successful data transfer, we assume 747 * the fault is just a bad record on the tape that we are now 748 * past. If we did not get any data since the last resync try 749 * to move the tape forward one PHYSICAL record past any 750 * damaged tape section. Some tape drives are stubborn and need 751 * to be pushed. 752 */ 753 if (io_ok) { 754 io_ok = 0; 755 lstrval = 1; 756 break; 757 } 758 mb.mt_op = MTFSR; 759 mb.mt_count = 1; 760 if (ioctl(arfd, MTIOCTOP, &mb) < 0) 761 break; 762 lstrval = 1; 763 break; 764 case ISREG: 765 case ISCHR: 766 case ISBLK: 767 /* 768 * try to step over the bad part of the device. 769 */ 770 io_ok = 0; 771 if (((fsbz = arsb.st_blksize) <= 0) || (artyp != ISREG)) 772 fsbz = BLKMULT; 773 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 774 break; 775 mpos = fsbz - (cpos % (off_t)fsbz); 776 if (lseek(arfd, mpos, SEEK_CUR) < 0) 777 break; 778 lstrval = 1; 779 break; 780 case ISPIPE: 781 default: 782 /* 783 * cannot recover on these archive device types 784 */ 785 io_ok = 0; 786 break; 787 } 788 if (lstrval <= 0) { 789 paxwarn(1, "Unable to recover from an archive read failure."); 790 return(-1); 791 } 792 paxwarn(0, "Attempting to recover from an archive read failure."); 793 return(0); 794 } 795 796 /* 797 * ar_fow() 798 * Move the I/O position within the archive forward the specified number of 799 * bytes as supported by the device. If we cannot move the requested 800 * number of bytes, return the actual number of bytes moved in skipped. 801 * Return: 802 * 0 if moved the requested distance, -1 on complete failure, 1 on 803 * partial move (the amount moved is in skipped) 804 */ 805 806 int 807 ar_fow(off_t sksz, off_t *skipped) 808 { 809 off_t cpos; 810 off_t mpos; 811 812 *skipped = 0; 813 if (sksz <= 0) 814 return(0); 815 816 /* 817 * we cannot move forward at EOF or error 818 */ 819 if (lstrval <= 0) 820 return(lstrval); 821 822 /* 823 * Safer to read forward on devices where it is hard to find the end of 824 * the media without reading to it. With tapes we cannot be sure of the 825 * number of physical blocks to skip (we do not know physical block 826 * size at this point), so we must only read forward on tapes! 827 */ 828 if (artyp != ISREG) 829 return(0); 830 831 /* 832 * figure out where we are in the archive 833 */ 834 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) >= 0) { 835 /* 836 * we can be asked to move farther than there are bytes in this 837 * volume, if so, just go to file end and let normal buf_fill() 838 * deal with the end of file (it will go to next volume by 839 * itself) 840 */ 841 if ((mpos = cpos + sksz) > arsb.st_size) { 842 *skipped = arsb.st_size - cpos; 843 mpos = arsb.st_size; 844 } else 845 *skipped = sksz; 846 if (lseek(arfd, mpos, SEEK_SET) >= 0) 847 return(0); 848 } 849 syswarn(1, errno, "Forward positioning operation on archive failed"); 850 lstrval = -1; 851 return(-1); 852 } 853 854 /* 855 * ar_rev() 856 * move the i/o position within the archive backwards the specified byte 857 * count as supported by the device. With tapes drives we RESET rdblksz to 858 * the PHYSICAL blocksize. 859 * NOTE: We should only be called to move backwards so we can rewrite the 860 * last records (the trailer) of an archive (APPEND). 861 * Return: 862 * 0 if moved the requested distance, -1 on complete failure 863 */ 864 865 int 866 ar_rev(off_t sksz) 867 { 868 off_t cpos; 869 struct mtop mb; 870 int phyblk; 871 872 /* 873 * make sure we do not have try to reverse on a flawed archive 874 */ 875 if (lstrval < 0) 876 return(lstrval); 877 878 switch(artyp) { 879 case ISPIPE: 880 if (sksz <= 0) 881 break; 882 /* 883 * cannot go backwards on these critters 884 */ 885 paxwarn(1, "Reverse positioning on pipes is not supported."); 886 lstrval = -1; 887 return(-1); 888 case ISREG: 889 case ISBLK: 890 case ISCHR: 891 default: 892 if (sksz <= 0) 893 break; 894 895 /* 896 * For things other than files, backwards movement has a very 897 * high probability of failure as we really do not know the 898 * true attributes of the device we are talking to (the device 899 * may not even have the ability to lseek() in any direction). 900 * First we figure out where we are in the archive. 901 */ 902 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) { 903 syswarn(1, errno, 904 "Unable to obtain current archive byte offset"); 905 lstrval = -1; 906 return(-1); 907 } 908 909 /* 910 * we may try to go backwards past the start when the archive 911 * is only a single record. If this happens and we are on a 912 * multi volume archive, we need to go to the end of the 913 * previous volume and continue our movement backwards from 914 * there. 915 */ 916 if ((cpos -= sksz) < (off_t)0L) { 917 if (arvol > 1) { 918 /* 919 * this should never happen 920 */ 921 paxwarn(1,"Reverse position on previous volume."); 922 lstrval = -1; 923 return(-1); 924 } 925 cpos = (off_t)0L; 926 } 927 if (lseek(arfd, cpos, SEEK_SET) < 0) { 928 syswarn(1, errno, "Unable to seek archive backwards"); 929 lstrval = -1; 930 return(-1); 931 } 932 break; 933 case ISTAPE: 934 /* 935 * Calculate and move the proper number of PHYSICAL tape 936 * blocks. If the sksz is not an even multiple of the physical 937 * tape size, we cannot do the move (this should never happen). 938 * (We also cannot handler trailers spread over two vols). 939 * get_phys() also makes sure we are in front of the filemark. 940 */ 941 if ((phyblk = get_phys()) <= 0) { 942 lstrval = -1; 943 return(-1); 944 } 945 946 /* 947 * make sure future tape reads only go by physical tape block 948 * size (set rdblksz to the real size). 949 */ 950 rdblksz = phyblk; 951 952 /* 953 * if no movement is required, just return (we must be after 954 * get_phys() so the physical blocksize is properly set) 955 */ 956 if (sksz <= 0) 957 break; 958 959 /* 960 * ok we have to move. Make sure the tape drive can do it. 961 */ 962 if (sksz % phyblk) { 963 paxwarn(1, 964 "Tape drive unable to backspace requested amount"); 965 lstrval = -1; 966 return(-1); 967 } 968 969 /* 970 * move backwards the requested number of bytes 971 */ 972 mb.mt_op = MTBSR; 973 mb.mt_count = sksz/phyblk; 974 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 975 syswarn(1,errno, "Unable to backspace tape %d blocks.", 976 mb.mt_count); 977 lstrval = -1; 978 return(-1); 979 } 980 break; 981 } 982 lstrval = 1; 983 return(0); 984 } 985 986 /* 987 * get_phys() 988 * Determine the physical block size on a tape drive. We need the physical 989 * block size so we know how many bytes we skip over when we move with 990 * mtio commands. We also make sure we are BEFORE THE TAPE FILEMARK when 991 * return. 992 * This is one really SLOW routine... 993 * Return: 994 * physical block size if ok (ok > 0), -1 otherwise 995 */ 996 997 static int 998 get_phys(void) 999 { 1000 int padsz = 0; 1001 int res; 1002 int phyblk; 1003 struct mtop mb; 1004 char scbuf[MAXBLK]; 1005 1006 /* 1007 * move to the file mark, and then back up one record and read it. 1008 * this should tell us the physical record size the tape is using. 1009 */ 1010 if (lstrval == 1) { 1011 /* 1012 * we know we are at file mark when we get back a 0 from 1013 * read() 1014 */ 1015 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1016 padsz += res; 1017 if (res < 0) { 1018 syswarn(1, errno, "Unable to locate tape filemark."); 1019 return(-1); 1020 } 1021 } 1022 1023 /* 1024 * move backwards over the file mark so we are at the end of the 1025 * last record. 1026 */ 1027 mb.mt_op = MTBSF; 1028 mb.mt_count = 1; 1029 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1030 syswarn(1, errno, "Unable to backspace over tape filemark."); 1031 return(-1); 1032 } 1033 1034 /* 1035 * move backwards so we are in front of the last record and read it to 1036 * get physical tape blocksize. 1037 */ 1038 mb.mt_op = MTBSR; 1039 mb.mt_count = 1; 1040 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1041 syswarn(1, errno, "Unable to backspace over last tape block."); 1042 return(-1); 1043 } 1044 if ((phyblk = read(arfd, scbuf, sizeof(scbuf))) <= 0) { 1045 syswarn(1, errno, "Cannot determine archive tape blocksize."); 1046 return(-1); 1047 } 1048 1049 /* 1050 * read forward to the file mark, then back up in front of the filemark 1051 * (this is a bit paranoid, but should be safe to do). 1052 */ 1053 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1054 ; 1055 if (res < 0) { 1056 syswarn(1, errno, "Unable to locate tape filemark."); 1057 return(-1); 1058 } 1059 mb.mt_op = MTBSF; 1060 mb.mt_count = 1; 1061 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1062 syswarn(1, errno, "Unable to backspace over tape filemark."); 1063 return(-1); 1064 } 1065 1066 /* 1067 * set lstrval so we know that the filemark has not been seen 1068 */ 1069 lstrval = 1; 1070 1071 /* 1072 * return if there was no padding 1073 */ 1074 if (padsz == 0) 1075 return(phyblk); 1076 1077 /* 1078 * make sure we can move backwards over the padding. (this should 1079 * never fail). 1080 */ 1081 if (padsz % phyblk) { 1082 paxwarn(1, "Tape drive unable to backspace requested amount"); 1083 return(-1); 1084 } 1085 1086 /* 1087 * move backwards over the padding so the head is where it was when 1088 * we were first called (if required). 1089 */ 1090 mb.mt_op = MTBSR; 1091 mb.mt_count = padsz/phyblk; 1092 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1093 syswarn(1,errno,"Unable to backspace tape over %d pad blocks", 1094 mb.mt_count); 1095 return(-1); 1096 } 1097 return(phyblk); 1098 } 1099 1100 /* 1101 * ar_next() 1102 * prompts the user for the next volume in this archive. For some devices 1103 * we may allow the media to be changed. Otherwise a new archive is 1104 * prompted for. By pax spec, if there is no controlling tty or an eof is 1105 * read on tty input, we must quit pax. 1106 * Return: 1107 * 0 when ready to continue, -1 when all done 1108 */ 1109 1110 int 1111 ar_next(void) 1112 { 1113 static char *arcbuf; 1114 char buf[PAXPATHLEN+2]; 1115 sigset_t o_mask; 1116 1117 /* 1118 * WE MUST CLOSE THE DEVICE. A lot of devices must see last close, (so 1119 * things like writing EOF etc will be done) (Watch out ar_close() can 1120 * also be called via a signal handler, so we must prevent a race. 1121 */ 1122 if (sigprocmask(SIG_BLOCK, &s_mask, &o_mask) < 0) 1123 syswarn(0, errno, "Unable to set signal mask"); 1124 ar_close(); 1125 if (sigprocmask(SIG_SETMASK, &o_mask, NULL) < 0) 1126 syswarn(0, errno, "Unable to restore signal mask"); 1127 1128 if (done || !wr_trail || Oflag || strcmp(NM_TAR, argv0) == 0) 1129 return(-1); 1130 1131 tty_prnt("\nATTENTION! %s archive volume change required.\n", argv0); 1132 1133 /* 1134 * if i/o is on stdin or stdout, we cannot reopen it (we do not know 1135 * the name), the user will be forced to type it in. 1136 */ 1137 if (strcmp(arcname, stdo) && strcmp(arcname, stdn) && (artyp != ISREG) 1138 && (artyp != ISPIPE)) { 1139 if (artyp == ISTAPE) { 1140 tty_prnt("%s ready for archive tape volume: %d\n", 1141 arcname, arvol); 1142 tty_prnt("Load the NEXT TAPE on the tape drive"); 1143 } else { 1144 tty_prnt("%s ready for archive volume: %d\n", 1145 arcname, arvol); 1146 tty_prnt("Load the NEXT STORAGE MEDIA (if required)"); 1147 } 1148 1149 if ((act == ARCHIVE) || (act == APPND)) 1150 tty_prnt(" and make sure it is WRITE ENABLED.\n"); 1151 else 1152 tty_prnt("\n"); 1153 1154 for(;;) { 1155 tty_prnt("Type \"y\" to continue, \".\" to quit %s,", 1156 argv0); 1157 tty_prnt(" or \"s\" to switch to new device.\nIf you"); 1158 tty_prnt(" cannot change storage media, type \"s\"\n"); 1159 tty_prnt("Is the device ready and online? > "); 1160 1161 if ((tty_read(buf,sizeof(buf))<0) || !strcmp(buf,".")){ 1162 done = 1; 1163 lstrval = -1; 1164 tty_prnt("Quitting %s!\n", argv0); 1165 vfpart = 0; 1166 return(-1); 1167 } 1168 1169 if ((buf[0] == '\0') || (buf[1] != '\0')) { 1170 tty_prnt("%s unknown command, try again\n",buf); 1171 continue; 1172 } 1173 1174 switch (buf[0]) { 1175 case 'y': 1176 case 'Y': 1177 /* 1178 * we are to continue with the same device 1179 */ 1180 if (ar_open(arcname) >= 0) 1181 return(0); 1182 tty_prnt("Cannot re-open %s, try again\n", 1183 arcname); 1184 continue; 1185 case 's': 1186 case 'S': 1187 /* 1188 * user wants to open a different device 1189 */ 1190 tty_prnt("Switching to a different archive\n"); 1191 break; 1192 default: 1193 tty_prnt("%s unknown command, try again\n",buf); 1194 continue; 1195 } 1196 break; 1197 } 1198 } else 1199 tty_prnt("Ready for archive volume: %d\n", arvol); 1200 1201 /* 1202 * have to go to a different archive 1203 */ 1204 for (;;) { 1205 tty_prnt("Input archive name or \".\" to quit %s.\n", argv0); 1206 tty_prnt("Archive name > "); 1207 1208 if ((tty_read(buf, sizeof(buf)) < 0) || !strcmp(buf, ".")) { 1209 done = 1; 1210 lstrval = -1; 1211 tty_prnt("Quitting %s!\n", argv0); 1212 vfpart = 0; 1213 return(-1); 1214 } 1215 if (buf[0] == '\0') { 1216 tty_prnt("Empty file name, try again\n"); 1217 continue; 1218 } 1219 if (!strcmp(buf, "..")) { 1220 tty_prnt("Illegal file name: .. try again\n"); 1221 continue; 1222 } 1223 if (strlen(buf) > PAXPATHLEN) { 1224 tty_prnt("File name too long, try again\n"); 1225 continue; 1226 } 1227 1228 /* 1229 * try to open new archive 1230 */ 1231 if (ar_open(buf) >= 0) { 1232 free(arcbuf); 1233 if ((arcbuf = strdup(buf)) == NULL) { 1234 done = 1; 1235 lstrval = -1; 1236 paxwarn(0, "Cannot save archive name."); 1237 return(-1); 1238 } 1239 arcname = arcbuf; 1240 break; 1241 } 1242 tty_prnt("Cannot open %s, try again\n", buf); 1243 continue; 1244 } 1245 return(0); 1246 } 1247 1248 /* 1249 * ar_start_gzip() 1250 * starts the gzip compression/decompression process as a child, using magic 1251 * to keep the fd the same in the calling function (parent). 1252 */ 1253 void 1254 ar_start_gzip(int fd, const char *gzip_prog, int wr) 1255 { 1256 int fds[2]; 1257 const char *gzip_flags; 1258 1259 if (pipe(fds) < 0) 1260 err(1, "could not pipe"); 1261 zpid = fork(); 1262 if (zpid < 0) 1263 err(1, "could not fork"); 1264 1265 /* parent */ 1266 if (zpid) { 1267 if (wr) 1268 dup2(fds[1], fd); 1269 else 1270 dup2(fds[0], fd); 1271 close(fds[0]); 1272 close(fds[1]); 1273 } else { 1274 if (wr) { 1275 dup2(fds[0], STDIN_FILENO); 1276 dup2(fd, STDOUT_FILENO); 1277 gzip_flags = "-c"; 1278 } else { 1279 dup2(fds[1], STDOUT_FILENO); 1280 dup2(fd, STDIN_FILENO); 1281 gzip_flags = "-dc"; 1282 } 1283 close(fds[0]); 1284 close(fds[1]); 1285 if (execlp(gzip_prog, gzip_prog, gzip_flags, 1286 (char *)NULL) < 0) 1287 err(1, "could not exec"); 1288 /* NOTREACHED */ 1289 } 1290 } 1291