1 /*- 2 * Copyright (c) 1992 Keith Muller. 3 * Copyright (c) 1992, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Keith Muller of the University of California, San Diego. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)ar_io.c 8.2 (Berkeley) 4/18/94 38 * $FreeBSD: src/bin/pax/ar_io.c,v 1.12.2.1 2001/08/01 05:03:11 obrien Exp $ 39 * $DragonFly: src/bin/pax/ar_io.c,v 1.11 2006/09/27 21:58:08 pavalos Exp $ 40 */ 41 42 #include <sys/types.h> 43 #include <sys/ioctl.h> 44 #include <sys/mtio.h> 45 #include <sys/stat.h> 46 #include <sys/wait.h> 47 #include <err.h> 48 #include <errno.h> 49 #include <fcntl.h> 50 #include <signal.h> 51 #include <stdio.h> 52 #include <string.h> 53 #include <stdlib.h> 54 #include <unistd.h> 55 #include "pax.h" 56 #include "options.h" 57 #include "extern.h" 58 59 /* 60 * Routines which deal directly with the archive I/O device/file. 61 */ 62 63 #define DMOD 0666 /* default mode of created archives */ 64 #define EXT_MODE O_RDONLY /* open mode for list/extract */ 65 #define AR_MODE (O_WRONLY | O_CREAT | O_TRUNC) /* mode for archive */ 66 #define APP_MODE O_RDWR /* mode for append */ 67 #define STDO "<STDOUT>" /* pseudo name for stdout */ 68 #define STDN "<STDIN>" /* pseudo name for stdin */ 69 static int arfd = -1; /* archive file descriptor */ 70 static int artyp = ISREG; /* archive type: file/FIFO/tape */ 71 static int arvol = 1; /* archive volume number */ 72 static int lstrval = -1; /* return value from last i/o */ 73 static int io_ok; /* i/o worked on volume after resync */ 74 static int did_io; /* did i/o ever occur on volume? */ 75 static int done; /* set via tty termination */ 76 static struct stat arsb; /* stat of archive device at open */ 77 static int invld_rec; /* tape has out of spec record size */ 78 static int wr_trail = 1; /* trailer was rewritten in append */ 79 static int can_unlnk = 0; /* do we unlink null archives? */ 80 char *arcname; /* printable name of archive */ 81 const char *gzip_program; /* name of gzip program */ 82 static pid_t zpid = -1; /* pid of child process */ 83 84 static int get_phys (void); 85 extern sigset_t s_mask; 86 static void ar_start_gzip (int, const char *, int); 87 88 /* 89 * ar_open() 90 * Opens the next archive volume. Determines the type of the device and 91 * sets up block sizes as required by the archive device and the format. 92 * Note: we may be called with name == NULL on the first open only. 93 * Return: 94 * -1 on failure, 0 otherwise 95 */ 96 97 int 98 ar_open(char *name) 99 { 100 struct mtget mb; 101 102 if (arfd != -1) 103 close(arfd); 104 arfd = -1; 105 can_unlnk = did_io = io_ok = invld_rec = 0; 106 artyp = ISREG; 107 flcnt = 0; 108 109 /* 110 * open based on overall operation mode 111 */ 112 switch (act) { 113 case LIST: 114 case EXTRACT: 115 if (name == NULL) { 116 arfd = STDIN_FILENO; 117 arcname = STDN; 118 } else if ((arfd = open(name, EXT_MODE, DMOD)) < 0) 119 syswarn(0, errno, "Failed open to read on %s", name); 120 if (arfd != -1 && gzip_program != NULL) 121 ar_start_gzip(arfd, gzip_program, 0); 122 break; 123 case ARCHIVE: 124 if (name == NULL) { 125 arfd = STDOUT_FILENO; 126 arcname = STDO; 127 } else if ((arfd = open(name, AR_MODE, DMOD)) < 0) 128 syswarn(0, errno, "Failed open to write on %s", name); 129 else 130 can_unlnk = 1; 131 if (arfd != -1 && gzip_program != NULL) 132 ar_start_gzip(arfd, gzip_program, 1); 133 break; 134 case APPND: 135 if (name == NULL) { 136 arfd = STDOUT_FILENO; 137 arcname = STDO; 138 } else if ((arfd = open(name, APP_MODE, DMOD)) < 0) 139 syswarn(0, errno, "Failed open to read/write on %s", 140 name); 141 break; 142 case COPY: 143 /* 144 * arfd not used in COPY mode 145 */ 146 arcname = "<NONE>"; 147 lstrval = 1; 148 return(0); 149 } 150 if (arfd < 0) 151 return(-1); 152 153 if (chdname != NULL) { 154 if (chdir(chdname) != 0) { 155 syswarn(1, errno, "Failed chdir to %s", chdname); 156 return(-1); 157 } 158 } 159 /* 160 * set up is based on device type 161 */ 162 if (fstat(arfd, &arsb) < 0) { 163 syswarn(0, errno, "Failed stat on %s", arcname); 164 close(arfd); 165 arfd = -1; 166 can_unlnk = 0; 167 return(-1); 168 } 169 if (S_ISDIR(arsb.st_mode)) { 170 paxwarn(0, "Cannot write an archive on top of a directory %s", 171 arcname); 172 close(arfd); 173 arfd = -1; 174 can_unlnk = 0; 175 return(-1); 176 } 177 178 if (S_ISCHR(arsb.st_mode)) 179 artyp = ioctl(arfd, MTIOCGET, &mb) ? ISCHR : ISTAPE; 180 else if (S_ISBLK(arsb.st_mode)) 181 artyp = ISBLK; 182 else if ((lseek(arfd, (off_t)0L, SEEK_CUR) == -1) && (errno == ESPIPE)) 183 artyp = ISPIPE; 184 else 185 artyp = ISREG; 186 187 /* 188 * make sure we beyond any doubt that we only can unlink regular files 189 * we created 190 */ 191 if (artyp != ISREG) 192 can_unlnk = 0; 193 /* 194 * if we are writing, we are done 195 */ 196 if (act == ARCHIVE) { 197 blksz = rdblksz = wrblksz; 198 lstrval = 1; 199 return(0); 200 } 201 202 /* 203 * set default blksz on read. APPNDs writes rdblksz on the last volume 204 * On all new archive volumes, we shift to wrblksz (if the user 205 * specified one, otherwise we will continue to use rdblksz). We 206 * must set blocksize based on what kind of device the archive is 207 * stored. 208 */ 209 switch(artyp) { 210 case ISTAPE: 211 /* 212 * Tape drives come in at least two flavors. Those that support 213 * variable sized records and those that have fixed sized 214 * records. They must be treated differently. For tape drives 215 * that support variable sized records, we must make large 216 * reads to make sure we get the entire record, otherwise we 217 * will just get the first part of the record (up to size we 218 * asked). Tapes with fixed sized records may or may not return 219 * multiple records in a single read. We really do not care 220 * what the physical record size is UNLESS we are going to 221 * append. (We will need the physical block size to rewrite 222 * the trailer). Only when we are appending do we go to the 223 * effort to figure out the true PHYSICAL record size. 224 */ 225 blksz = rdblksz = MAXBLK; 226 break; 227 case ISPIPE: 228 case ISBLK: 229 case ISCHR: 230 /* 231 * Blocksize is not a major issue with these devices (but must 232 * be kept a multiple of 512). If the user specified a write 233 * block size, we use that to read. Under append, we must 234 * always keep blksz == rdblksz. Otherwise we go ahead and use 235 * the device optimal blocksize as (and if) returned by stat 236 * and if it is within pax specs. 237 */ 238 if ((act == APPND) && wrblksz) { 239 blksz = rdblksz = wrblksz; 240 break; 241 } 242 243 if ((arsb.st_blksize > 0) && (arsb.st_blksize < MAXBLK) && 244 ((arsb.st_blksize % BLKMULT) == 0)) 245 rdblksz = arsb.st_blksize; 246 else 247 rdblksz = DEVBLK; 248 /* 249 * For performance go for large reads when we can without harm 250 */ 251 if ((act == APPND) || (artyp == ISCHR)) 252 blksz = rdblksz; 253 else 254 blksz = MAXBLK; 255 break; 256 case ISREG: 257 /* 258 * if the user specified wrblksz works, use it. Under appends 259 * we must always keep blksz == rdblksz 260 */ 261 if ((act == APPND) && wrblksz && ((arsb.st_size%wrblksz)==0)){ 262 blksz = rdblksz = wrblksz; 263 break; 264 } 265 /* 266 * See if we can find the blocking factor from the file size 267 */ 268 for (rdblksz = MAXBLK; rdblksz > 0; rdblksz -= BLKMULT) 269 if ((arsb.st_size % rdblksz) == 0) 270 break; 271 /* 272 * When we cannot find a match, we may have a flawed archive. 273 */ 274 if (rdblksz <= 0) 275 rdblksz = FILEBLK; 276 /* 277 * for performance go for large reads when we can 278 */ 279 if (act == APPND) 280 blksz = rdblksz; 281 else 282 blksz = MAXBLK; 283 break; 284 default: 285 /* 286 * should never happen, worst case, slow... 287 */ 288 blksz = rdblksz = BLKMULT; 289 break; 290 } 291 lstrval = 1; 292 return(0); 293 } 294 295 /* 296 * ar_close() 297 * closes archive device, increments volume number, and prints i/o summary 298 */ 299 void 300 ar_close(void) 301 { 302 int status; 303 304 if (arfd < 0) { 305 did_io = io_ok = flcnt = 0; 306 return; 307 } 308 309 /* 310 * Close archive file. This may take a LONG while on tapes (we may be 311 * forced to wait for the rewind to complete) so tell the user what is 312 * going on (this avoids the user hitting control-c thinking pax is 313 * broken). 314 */ 315 if (vflag && (artyp == ISTAPE)) { 316 if (vfpart) 317 putc('\n', listf); 318 fprintf(listf, 319 "%s: Waiting for tape drive close to complete...", 320 argv0); 321 fflush(listf); 322 } 323 324 /* 325 * if nothing was written to the archive (and we created it), we remove 326 * it 327 */ 328 if (can_unlnk && (fstat(arfd, &arsb) == 0) && (S_ISREG(arsb.st_mode)) && 329 (arsb.st_size == 0)) { 330 unlink(arcname); 331 can_unlnk = 0; 332 } 333 334 /* 335 * for a quick extract/list, pax frequently exits before the child 336 * process is done 337 */ 338 if ((act == LIST || act == EXTRACT) && nflag && zpid > 0) 339 kill(zpid, SIGINT); 340 341 close(arfd); 342 343 /* Do not exit before child to ensure data integrity */ 344 if (zpid > 0) 345 waitpid(zpid, &status, 0); 346 347 if (vflag && (artyp == ISTAPE)) { 348 fputs("done.\n", listf); 349 vfpart = 0; 350 fflush(listf); 351 } 352 arfd = -1; 353 354 if (!io_ok && !did_io) { 355 flcnt = 0; 356 return; 357 } 358 did_io = io_ok = 0; 359 360 /* 361 * The volume number is only increased when the last device has data 362 * and we have already determined the archive format. 363 */ 364 if (frmt != NULL) 365 ++arvol; 366 367 if (!vflag) { 368 flcnt = 0; 369 return; 370 } 371 372 /* 373 * Print out a summary of I/O for this archive volume. 374 */ 375 if (vfpart) { 376 putc('\n', listf); 377 vfpart = 0; 378 } 379 380 /* 381 * If we have not determined the format yet, we just say how many bytes 382 * we have skipped over looking for a header to id. there is no way we 383 * could have written anything yet. 384 */ 385 if (frmt == NULL) { 386 fprintf(listf, "%s: unknown format, %qu bytes skipped.\n", 387 argv0, rdcnt); 388 fflush(listf); 389 flcnt = 0; 390 return; 391 } 392 393 if (strcmp(NM_CPIO, argv0) == 0) 394 fprintf(listf, "%qu blocks\n", (rdcnt ? rdcnt : wrcnt) / 5120); 395 else if (strcmp(NM_TAR, argv0) != 0) 396 fprintf(listf, 397 "%s: %s vol %d, %lu files, %qu bytes read, %qu bytes written.\n", 398 argv0, frmt->name, arvol-1, flcnt, rdcnt, wrcnt); 399 fflush(listf); 400 flcnt = 0; 401 } 402 403 /* 404 * ar_drain() 405 * drain any archive format independent padding from an archive read 406 * from a socket or a pipe. This is to prevent the process on the 407 * other side of the pipe from getting a SIGPIPE (pax will stop 408 * reading an archive once a format dependent trailer is detected). 409 */ 410 void 411 ar_drain(void) 412 { 413 int res; 414 char drbuf[MAXBLK]; 415 416 /* 417 * we only drain from a pipe/socket. Other devices can be closed 418 * without reading up to end of file. We sure hope that pipe is closed 419 * on the other side so we will get an EOF. 420 */ 421 if ((artyp != ISPIPE) || (lstrval <= 0)) 422 return; 423 424 /* 425 * keep reading until pipe is drained 426 */ 427 while ((res = read(arfd, drbuf, sizeof(drbuf))) > 0) 428 ; 429 lstrval = res; 430 } 431 432 /* 433 * ar_set_wr() 434 * Set up device right before switching from read to write in an append. 435 * device dependent code (if required) to do this should be added here. 436 * For all archive devices we are already positioned at the place we want 437 * to start writing when this routine is called. 438 * Return: 439 * 0 if all ready to write, -1 otherwise 440 */ 441 442 int 443 ar_set_wr(void) 444 { 445 off_t cpos; 446 447 /* 448 * we must make sure the trailer is rewritten on append, ar_next() 449 * will stop us if the archive containing the trailer was not written 450 */ 451 wr_trail = 0; 452 453 /* 454 * Add any device dependent code as required here 455 */ 456 if (artyp != ISREG) 457 return(0); 458 /* 459 * Ok we have an archive in a regular file. If we were rewriting a 460 * file, we must get rid of all the stuff after the current offset 461 * (it was not written by pax). 462 */ 463 if (((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) || 464 (ftruncate(arfd, cpos) < 0)) { 465 syswarn(1, errno, "Unable to truncate archive file"); 466 return(-1); 467 } 468 return(0); 469 } 470 471 /* 472 * ar_app_ok() 473 * check if the last volume in the archive allows appends. We cannot check 474 * this until we are ready to write since there is no spec that says all 475 * volumes in a single archive have to be of the same type... 476 * Return: 477 * 0 if we can append, -1 otherwise. 478 */ 479 480 int 481 ar_app_ok(void) 482 { 483 if (artyp == ISPIPE) { 484 paxwarn(1, "Cannot append to an archive obtained from a pipe."); 485 return(-1); 486 } 487 488 if (!invld_rec) 489 return(0); 490 paxwarn(1,"Cannot append, device record size %d does not support %s spec", 491 rdblksz, argv0); 492 return(-1); 493 } 494 495 /* 496 * ar_read() 497 * read up to a specified number of bytes from the archive into the 498 * supplied buffer. When dealing with tapes we may not always be able to 499 * read what we want. 500 * Return: 501 * Number of bytes in buffer. 0 for end of file, -1 for a read error. 502 */ 503 504 int 505 ar_read(char *buf, int cnt) 506 { 507 int res = 0; 508 509 /* 510 * if last i/o was in error, no more reads until reset or new volume 511 */ 512 if (lstrval <= 0) 513 return(lstrval); 514 515 /* 516 * how we read must be based on device type 517 */ 518 switch (artyp) { 519 case ISTAPE: 520 if ((res = read(arfd, buf, cnt)) > 0) { 521 /* 522 * CAUTION: tape systems may not always return the same 523 * sized records so we leave blksz == MAXBLK. The 524 * physical record size that a tape drive supports is 525 * very hard to determine in a uniform and portable 526 * manner. 527 */ 528 io_ok = 1; 529 if (res != rdblksz) { 530 /* 531 * Record size changed. If this happens on 532 * any record after the first, we probably have 533 * a tape drive which has a fixed record size 534 * (we are getting multiple records in a single 535 * read). Watch out for record blocking that 536 * violates pax spec (must be a multiple of 537 * BLKMULT). 538 */ 539 rdblksz = res; 540 if (rdblksz % BLKMULT) 541 invld_rec = 1; 542 } 543 return(res); 544 } 545 break; 546 case ISREG: 547 case ISBLK: 548 case ISCHR: 549 case ISPIPE: 550 default: 551 /* 552 * Files are so easy to deal with. These other things cannot 553 * be trusted at all. So when we are dealing with character 554 * devices and pipes we just take what they have ready for us 555 * and return. Trying to do anything else with them runs the 556 * risk of failure. 557 */ 558 if ((res = read(arfd, buf, cnt)) > 0) { 559 io_ok = 1; 560 return(res); 561 } 562 break; 563 } 564 565 /* 566 * We are in trouble at this point, something is broken... 567 */ 568 lstrval = res; 569 if (res < 0) 570 syswarn(1, errno, "Failed read on archive volume %d", arvol); 571 else 572 paxwarn(0, "End of archive volume %d reached", arvol); 573 return(res); 574 } 575 576 /* 577 * ar_write() 578 * Write a specified number of bytes in supplied buffer to the archive 579 * device so it appears as a single "block". Deals with errors and tries 580 * to recover when faced with short writes. 581 * Return: 582 * Number of bytes written. 0 indicates end of volume reached and with no 583 * flaws (as best that can be detected). A -1 indicates an unrecoverable 584 * error in the archive occurred. 585 */ 586 587 int 588 ar_write(char *buf, int bsz) 589 { 590 int res; 591 off_t cpos; 592 593 /* 594 * do not allow pax to create a "bad" archive. Once a write fails on 595 * an archive volume prevent further writes to it. 596 */ 597 if (lstrval <= 0) 598 return(lstrval); 599 600 if ((res = write(arfd, buf, bsz)) == bsz) { 601 wr_trail = 1; 602 io_ok = 1; 603 return(bsz); 604 } 605 /* 606 * write broke, see what we can do with it. We try to send any partial 607 * writes that may violate pax spec to the next archive volume. 608 */ 609 if (res < 0) 610 lstrval = res; 611 else 612 lstrval = 0; 613 614 switch (artyp) { 615 case ISREG: 616 if ((res > 0) && (res % BLKMULT)) { 617 /* 618 * try to fix up partial writes which are not BLKMULT 619 * in size by forcing the runt record to next archive 620 * volume 621 */ 622 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 623 break; 624 cpos -= (off_t)res; 625 if (ftruncate(arfd, cpos) < 0) 626 break; 627 res = lstrval = 0; 628 break; 629 } 630 if (res >= 0) 631 break; 632 /* 633 * if file is out of space, handle it like a return of 0 634 */ 635 if ((errno == ENOSPC) || (errno == EFBIG) || (errno == EDQUOT)) 636 res = lstrval = 0; 637 break; 638 case ISTAPE: 639 case ISCHR: 640 case ISBLK: 641 if (res >= 0) 642 break; 643 if (errno == EACCES) { 644 paxwarn(0, "Write failed, archive is write protected."); 645 res = lstrval = 0; 646 return(0); 647 } 648 /* 649 * see if we reached the end of media, if so force a change to 650 * the next volume 651 */ 652 if ((errno == ENOSPC) || (errno == EIO) || (errno == ENXIO)) 653 res = lstrval = 0; 654 break; 655 case ISPIPE: 656 default: 657 /* 658 * we cannot fix errors to these devices 659 */ 660 break; 661 } 662 663 /* 664 * Better tell the user the bad news... 665 * if this is a block aligned archive format, we may have a bad archive 666 * if the format wants the header to start at a BLKMULT boundary. While 667 * we can deal with the mis-aligned data, it violates spec and other 668 * archive readers will likely fail. if the format is not block 669 * aligned, the user may be lucky (and the archive is ok). 670 */ 671 if (res >= 0) { 672 if (res > 0) 673 wr_trail = 1; 674 io_ok = 1; 675 } 676 677 /* 678 * If we were trying to rewrite the trailer and it didn't work, we 679 * must quit right away. 680 */ 681 if (!wr_trail && (res <= 0)) { 682 paxwarn(1,"Unable to append, trailer re-write failed. Quitting."); 683 return(res); 684 } 685 686 if (res == 0) 687 paxwarn(0, "End of archive volume %d reached", arvol); 688 else if (res < 0) 689 syswarn(1, errno, "Failed write to archive volume: %d", arvol); 690 else if (!frmt->blkalgn || ((res % frmt->blkalgn) == 0)) 691 paxwarn(0,"WARNING: partial archive write. Archive MAY BE FLAWED"); 692 else 693 paxwarn(1,"WARNING: partial archive write. Archive IS FLAWED"); 694 return(res); 695 } 696 697 /* 698 * ar_rdsync() 699 * Try to move past a bad spot on a flawed archive as needed to continue 700 * I/O. Clears error flags to allow I/O to continue. 701 * Return: 702 * 0 when ok to try i/o again, -1 otherwise. 703 */ 704 705 int 706 ar_rdsync(void) 707 { 708 long fsbz; 709 off_t cpos; 710 off_t mpos; 711 struct mtop mb; 712 713 /* 714 * Fail resync attempts at user request (done) or if this is going to be 715 * an update/append to a existing archive. if last i/o hit media end, 716 * we need to go to the next volume not try a resync 717 */ 718 if ((done > 0) || (lstrval == 0)) 719 return(-1); 720 721 if ((act == APPND) || (act == ARCHIVE)) { 722 paxwarn(1, "Cannot allow updates to an archive with flaws."); 723 return(-1); 724 } 725 if (io_ok) 726 did_io = 1; 727 728 switch(artyp) { 729 case ISTAPE: 730 /* 731 * if the last i/o was a successful data transfer, we assume 732 * the fault is just a bad record on the tape that we are now 733 * past. If we did not get any data since the last resync try 734 * to move the tape forward one PHYSICAL record past any 735 * damaged tape section. Some tape drives are stubborn and need 736 * to be pushed. 737 */ 738 if (io_ok) { 739 io_ok = 0; 740 lstrval = 1; 741 break; 742 } 743 mb.mt_op = MTFSR; 744 mb.mt_count = 1; 745 if (ioctl(arfd, MTIOCTOP, &mb) < 0) 746 break; 747 lstrval = 1; 748 break; 749 case ISREG: 750 case ISCHR: 751 case ISBLK: 752 /* 753 * try to step over the bad part of the device. 754 */ 755 io_ok = 0; 756 if (((fsbz = arsb.st_blksize) <= 0) || (artyp != ISREG)) 757 fsbz = BLKMULT; 758 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 759 break; 760 mpos = fsbz - (cpos % (off_t)fsbz); 761 if (lseek(arfd, mpos, SEEK_CUR) < 0) 762 break; 763 lstrval = 1; 764 break; 765 case ISPIPE: 766 default: 767 /* 768 * cannot recover on these archive device types 769 */ 770 io_ok = 0; 771 break; 772 } 773 if (lstrval <= 0) { 774 paxwarn(1, "Unable to recover from an archive read failure."); 775 return(-1); 776 } 777 paxwarn(0, "Attempting to recover from an archive read failure."); 778 return(0); 779 } 780 781 /* 782 * ar_fow() 783 * Move the I/O position within the archive forward the specified number of 784 * bytes as supported by the device. If we cannot move the requested 785 * number of bytes, return the actual number of bytes moved in skipped. 786 * Return: 787 * 0 if moved the requested distance, -1 on complete failure, 1 on 788 * partial move (the amount moved is in skipped) 789 */ 790 791 int 792 ar_fow(off_t sksz, off_t *skipped) 793 { 794 off_t cpos; 795 off_t mpos; 796 797 *skipped = 0; 798 if (sksz <= 0) 799 return(0); 800 801 /* 802 * we cannot move forward at EOF or error 803 */ 804 if (lstrval <= 0) 805 return(lstrval); 806 807 /* 808 * Safer to read forward on devices where it is hard to find the end of 809 * the media without reading to it. With tapes we cannot be sure of the 810 * number of physical blocks to skip (we do not know physical block 811 * size at this point), so we must only read forward on tapes! 812 */ 813 if (artyp != ISREG) 814 return(0); 815 816 /* 817 * figure out where we are in the archive 818 */ 819 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) >= 0) { 820 /* 821 * we can be asked to move farther than there are bytes in this 822 * volume, if so, just go to file end and let normal buf_fill() 823 * deal with the end of file (it will go to next volume by 824 * itself) 825 */ 826 if ((mpos = cpos + sksz) > arsb.st_size) { 827 *skipped = arsb.st_size - cpos; 828 mpos = arsb.st_size; 829 } else 830 *skipped = sksz; 831 if (lseek(arfd, mpos, SEEK_SET) >= 0) 832 return(0); 833 } 834 syswarn(1, errno, "Forward positioning operation on archive failed"); 835 lstrval = -1; 836 return(-1); 837 } 838 839 /* 840 * ar_rev() 841 * move the i/o position within the archive backwards the specified byte 842 * count as supported by the device. With tapes drives we RESET rdblksz to 843 * the PHYSICAL blocksize. 844 * NOTE: We should only be called to move backwards so we can rewrite the 845 * last records (the trailer) of an archive (APPEND). 846 * Return: 847 * 0 if moved the requested distance, -1 on complete failure 848 */ 849 850 int 851 ar_rev(off_t sksz) 852 { 853 off_t cpos; 854 struct mtop mb; 855 int phyblk; 856 857 /* 858 * make sure we do not have try to reverse on a flawed archive 859 */ 860 if (lstrval < 0) 861 return(lstrval); 862 863 switch(artyp) { 864 case ISPIPE: 865 if (sksz <= 0) 866 break; 867 /* 868 * cannot go backwards on these critters 869 */ 870 paxwarn(1, "Reverse positioning on pipes is not supported."); 871 lstrval = -1; 872 return(-1); 873 case ISREG: 874 case ISBLK: 875 case ISCHR: 876 default: 877 if (sksz <= 0) 878 break; 879 880 /* 881 * For things other than files, backwards movement has a very 882 * high probability of failure as we really do not know the 883 * true attributes of the device we are talking to (the device 884 * may not even have the ability to lseek() in any direction). 885 * First we figure out where we are in the archive. 886 */ 887 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) { 888 syswarn(1, errno, 889 "Unable to obtain current archive byte offset"); 890 lstrval = -1; 891 return(-1); 892 } 893 894 /* 895 * we may try to go backwards past the start when the archive 896 * is only a single record. If this happens and we are on a 897 * multi-volume archive, we need to go to the end of the 898 * previous volume and continue our movement backwards from 899 * there. 900 */ 901 if ((cpos -= sksz) < (off_t)0L) { 902 if (arvol > 1) { 903 /* 904 * this should never happen 905 */ 906 paxwarn(1,"Reverse position on previous volume."); 907 lstrval = -1; 908 return(-1); 909 } 910 cpos = (off_t)0L; 911 } 912 if (lseek(arfd, cpos, SEEK_SET) < 0) { 913 syswarn(1, errno, "Unable to seek archive backwards"); 914 lstrval = -1; 915 return(-1); 916 } 917 break; 918 case ISTAPE: 919 /* 920 * Calculate and move the proper number of PHYSICAL tape 921 * blocks. If the sksz is not an even multiple of the physical 922 * tape size, we cannot do the move (this should never happen). 923 * (We also cannot handle trailers spread over two vols.) 924 * get_phys() also makes sure we are in front of the filemark. 925 */ 926 if ((phyblk = get_phys()) <= 0) { 927 lstrval = -1; 928 return(-1); 929 } 930 931 /* 932 * make sure future tape reads only go by physical tape block 933 * size (set rdblksz to the real size). 934 */ 935 rdblksz = phyblk; 936 937 /* 938 * if no movement is required, just return (we must be after 939 * get_phys() so the physical blocksize is properly set) 940 */ 941 if (sksz <= 0) 942 break; 943 944 /* 945 * ok we have to move. Make sure the tape drive can do it. 946 */ 947 if (sksz % phyblk) { 948 paxwarn(1, 949 "Tape drive unable to backspace requested amount"); 950 lstrval = -1; 951 return(-1); 952 } 953 954 /* 955 * move backwards the requested number of bytes 956 */ 957 mb.mt_op = MTBSR; 958 mb.mt_count = sksz/phyblk; 959 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 960 syswarn(1,errno, "Unable to backspace tape %d blocks.", 961 mb.mt_count); 962 lstrval = -1; 963 return(-1); 964 } 965 break; 966 } 967 lstrval = 1; 968 return(0); 969 } 970 971 /* 972 * get_phys() 973 * Determine the physical block size on a tape drive. We need the physical 974 * block size so we know how many bytes we skip over when we move with 975 * mtio commands. We also make sure we are BEFORE THE TAPE FILEMARK when 976 * return. 977 * This is one really SLOW routine... 978 * Return: 979 * physical block size if ok (ok > 0), -1 otherwise 980 */ 981 982 static int 983 get_phys(void) 984 { 985 int padsz = 0; 986 int res; 987 int phyblk; 988 struct mtop mb; 989 char scbuf[MAXBLK]; 990 991 /* 992 * move to the file mark, and then back up one record and read it. 993 * this should tell us the physical record size the tape is using. 994 */ 995 if (lstrval == 1) { 996 /* 997 * we know we are at file mark when we get back a 0 from 998 * read() 999 */ 1000 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1001 padsz += res; 1002 if (res < 0) { 1003 syswarn(1, errno, "Unable to locate tape filemark."); 1004 return(-1); 1005 } 1006 } 1007 1008 /* 1009 * move backwards over the file mark so we are at the end of the 1010 * last record. 1011 */ 1012 mb.mt_op = MTBSF; 1013 mb.mt_count = 1; 1014 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1015 syswarn(1, errno, "Unable to backspace over tape filemark."); 1016 return(-1); 1017 } 1018 1019 /* 1020 * move backwards so we are in front of the last record and read it to 1021 * get physical tape blocksize. 1022 */ 1023 mb.mt_op = MTBSR; 1024 mb.mt_count = 1; 1025 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1026 syswarn(1, errno, "Unable to backspace over last tape block."); 1027 return(-1); 1028 } 1029 if ((phyblk = read(arfd, scbuf, sizeof(scbuf))) <= 0) { 1030 syswarn(1, errno, "Cannot determine archive tape blocksize."); 1031 return(-1); 1032 } 1033 1034 /* 1035 * read forward to the file mark, then back up in front of the filemark 1036 * (this is a bit paranoid, but should be safe to do). 1037 */ 1038 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1039 ; 1040 if (res < 0) { 1041 syswarn(1, errno, "Unable to locate tape filemark."); 1042 return(-1); 1043 } 1044 mb.mt_op = MTBSF; 1045 mb.mt_count = 1; 1046 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1047 syswarn(1, errno, "Unable to backspace over tape filemark."); 1048 return(-1); 1049 } 1050 1051 /* 1052 * set lstrval so we know that the filemark has not been seen 1053 */ 1054 lstrval = 1; 1055 1056 /* 1057 * return if there was no padding 1058 */ 1059 if (padsz == 0) 1060 return(phyblk); 1061 1062 /* 1063 * make sure we can move backwards over the padding. (this should 1064 * never fail). 1065 */ 1066 if (padsz % phyblk) { 1067 paxwarn(1, "Tape drive unable to backspace requested amount"); 1068 return(-1); 1069 } 1070 1071 /* 1072 * move backwards over the padding so the head is where it was when 1073 * we were first called (if required). 1074 */ 1075 mb.mt_op = MTBSR; 1076 mb.mt_count = padsz/phyblk; 1077 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1078 syswarn(1,errno,"Unable to backspace tape over %d pad blocks", 1079 mb.mt_count); 1080 return(-1); 1081 } 1082 return(phyblk); 1083 } 1084 1085 /* 1086 * ar_next() 1087 * prompts the user for the next volume in this archive. For some devices 1088 * we may allow the media to be changed. Otherwise a new archive is 1089 * prompted for. By pax spec, if there is no controlling tty or an eof is 1090 * read on tty input, we must quit pax. 1091 * Return: 1092 * 0 when ready to continue, -1 when all done 1093 */ 1094 1095 int 1096 ar_next(void) 1097 { 1098 char buf[PAXPATHLEN+2]; 1099 static int freeit = 0; 1100 sigset_t o_mask; 1101 1102 /* 1103 * WE MUST CLOSE THE DEVICE. A lot of devices must see last close, (so 1104 * things like writing EOF etc will be done) (Watch out ar_close() can 1105 * also be called via a signal handler, so we must prevent a race. 1106 */ 1107 if (sigprocmask(SIG_BLOCK, &s_mask, &o_mask) < 0) 1108 syswarn(0, errno, "Unable to set signal mask"); 1109 ar_close(); 1110 if (sigprocmask(SIG_SETMASK, &o_mask, NULL) < 0) 1111 syswarn(0, errno, "Unable to restore signal mask"); 1112 1113 if (done || !wr_trail || strcmp(NM_TAR, argv0) == 0) 1114 return(-1); 1115 1116 tty_prnt("\nATTENTION! %s archive volume change required.\n", argv0); 1117 1118 /* 1119 * if i/o is on stdin or stdout, we cannot reopen it (we do not know 1120 * the name), the user will be forced to type it in. 1121 */ 1122 if (strcmp(arcname, STDO) && strcmp(arcname, STDN) && (artyp != ISREG) 1123 && (artyp != ISPIPE)) { 1124 if (artyp == ISTAPE) { 1125 tty_prnt("%s ready for archive tape volume: %d\n", 1126 arcname, arvol); 1127 tty_prnt("Load the NEXT TAPE on the tape drive"); 1128 } else { 1129 tty_prnt("%s ready for archive volume: %d\n", 1130 arcname, arvol); 1131 tty_prnt("Load the NEXT STORAGE MEDIA (if required)"); 1132 } 1133 1134 if ((act == ARCHIVE) || (act == APPND)) 1135 tty_prnt(" and make sure it is WRITE ENABLED.\n"); 1136 else 1137 tty_prnt("\n"); 1138 1139 for(;;) { 1140 tty_prnt("Type \"y\" to continue, \".\" to quit %s,", 1141 argv0); 1142 tty_prnt(" or \"s\" to switch to new device.\nIf you"); 1143 tty_prnt(" cannot change storage media, type \"s\"\n"); 1144 tty_prnt("Is the device ready and online? > "); 1145 1146 if ((tty_read(buf,sizeof(buf))<0) || !strcmp(buf,".")){ 1147 done = 1; 1148 lstrval = -1; 1149 tty_prnt("Quitting %s!\n", argv0); 1150 vfpart = 0; 1151 return(-1); 1152 } 1153 1154 if ((buf[0] == '\0') || (buf[1] != '\0')) { 1155 tty_prnt("%s unknown command, try again\n",buf); 1156 continue; 1157 } 1158 1159 switch (buf[0]) { 1160 case 'y': 1161 case 'Y': 1162 /* 1163 * we are to continue with the same device 1164 */ 1165 if (ar_open(arcname) >= 0) 1166 return(0); 1167 tty_prnt("Cannot re-open %s, try again\n", 1168 arcname); 1169 continue; 1170 case 's': 1171 case 'S': 1172 /* 1173 * user wants to open a different device 1174 */ 1175 tty_prnt("Switching to a different archive\n"); 1176 break; 1177 default: 1178 tty_prnt("%s unknown command, try again\n",buf); 1179 continue; 1180 } 1181 break; 1182 } 1183 } else 1184 tty_prnt("Ready for archive volume: %d\n", arvol); 1185 1186 /* 1187 * have to go to a different archive 1188 */ 1189 for (;;) { 1190 tty_prnt("Input archive name or \".\" to quit %s.\n", argv0); 1191 tty_prnt("Archive name > "); 1192 1193 if ((tty_read(buf, sizeof(buf)) < 0) || !strcmp(buf, ".")) { 1194 done = 1; 1195 lstrval = -1; 1196 tty_prnt("Quitting %s!\n", argv0); 1197 vfpart = 0; 1198 return(-1); 1199 } 1200 if (buf[0] == '\0') { 1201 tty_prnt("Empty file name, try again\n"); 1202 continue; 1203 } 1204 if (!strcmp(buf, "..")) { 1205 tty_prnt("Illegal file name: .. try again\n"); 1206 continue; 1207 } 1208 if (strlen(buf) > PAXPATHLEN) { 1209 tty_prnt("File name too long, try again\n"); 1210 continue; 1211 } 1212 1213 /* 1214 * try to open new archive 1215 */ 1216 if (ar_open(buf) >= 0) { 1217 if (freeit) { 1218 free(arcname); 1219 freeit = 0; 1220 } 1221 if ((arcname = strdup(buf)) == NULL) { 1222 done = 1; 1223 lstrval = -1; 1224 paxwarn(0, "Cannot save archive name."); 1225 return(-1); 1226 } 1227 freeit = 1; 1228 break; 1229 } 1230 tty_prnt("Cannot open %s, try again\n", buf); 1231 continue; 1232 } 1233 return(0); 1234 } 1235 1236 /* 1237 * ar_start_gzip() 1238 * starts the gzip compression/decompression process as a child, using magic 1239 * to keep the fd the same in the calling function (parent). 1240 */ 1241 void 1242 ar_start_gzip(int fd, const char *gzip_program, int wr) 1243 { 1244 int fds[2]; 1245 char *gzip_flags; 1246 1247 if (pipe(fds) < 0) 1248 err(1, "could not pipe"); 1249 zpid = fork(); 1250 if (zpid < 0) 1251 err(1, "could not fork"); 1252 1253 /* parent */ 1254 if (zpid) { 1255 if (wr) 1256 dup2(fds[1], fd); 1257 else 1258 dup2(fds[0], fd); 1259 close(fds[0]); 1260 close(fds[1]); 1261 } else { 1262 if (wr) { 1263 dup2(fds[0], STDIN_FILENO); 1264 dup2(fd, STDOUT_FILENO); 1265 gzip_flags = "-c"; 1266 } else { 1267 dup2(fds[1], STDOUT_FILENO); 1268 dup2(fd, STDIN_FILENO); 1269 gzip_flags = "-dc"; 1270 } 1271 close(fds[0]); 1272 close(fds[1]); 1273 if (execlp(gzip_program, gzip_program, gzip_flags, 1274 (char *)NULL) < 0) 1275 err(1, "could not exec"); 1276 /* NOTREACHED */ 1277 } 1278 } 1279