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 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 #if 0 36 static char sccsid[] = "@(#)ar_io.c 8.2 (Berkeley) 4/18/94"; 37 #endif 38 #endif /* not lint */ 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 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 <stdint.h> 52 #include <stdio.h> 53 #include <string.h> 54 #include <stdlib.h> 55 #include <unistd.h> 56 #include "pax.h" 57 #include "options.h" 58 #include "extern.h" 59 60 /* 61 * Routines which deal directly with the archive I/O device/file. 62 */ 63 64 #define DMOD 0666 /* default mode of created archives */ 65 #define EXT_MODE O_RDONLY /* open mode for list/extract */ 66 #define AR_MODE (O_WRONLY | O_CREAT | O_TRUNC) /* mode for archive */ 67 #define APP_MODE O_RDWR /* mode for append */ 68 69 static char none[] = "<NONE>"; /* pseudo name for no file */ 70 static char stdo[] = "<STDOUT>"; /* pseudo name for stdout */ 71 static char stdn[] = "<STDIN>"; /* pseudo name for stdin */ 72 static int arfd = -1; /* archive file descriptor */ 73 static int artyp = ISREG; /* archive type: file/FIFO/tape */ 74 static int arvol = 1; /* archive volume number */ 75 static int lstrval = -1; /* return value from last i/o */ 76 static int io_ok; /* i/o worked on volume after resync */ 77 static int did_io; /* did i/o ever occur on volume? */ 78 static int done; /* set via tty termination */ 79 static struct stat arsb; /* stat of archive device at open */ 80 static int invld_rec; /* tape has out of spec record size */ 81 static int wr_trail = 1; /* trailer was rewritten in append */ 82 static int can_unlnk = 0; /* do we unlink null archives? */ 83 const char *arcname; /* printable name of archive */ 84 const char *gzip_program; /* name of gzip program */ 85 static pid_t zpid = -1; /* pid of child process */ 86 87 static int get_phys(void); 88 extern sigset_t s_mask; 89 static void ar_start_gzip(int, const char *, int); 90 91 /* 92 * ar_open() 93 * Opens the next archive volume. Determines the type of the device and 94 * sets up block sizes as required by the archive device and the format. 95 * Note: we may be called with name == NULL on the first open only. 96 * Return: 97 * -1 on failure, 0 otherwise 98 */ 99 100 int 101 ar_open(const char *name) 102 { 103 struct mtget mb; 104 105 if (arfd != -1) 106 (void)close(arfd); 107 arfd = -1; 108 can_unlnk = did_io = io_ok = invld_rec = 0; 109 artyp = ISREG; 110 flcnt = 0; 111 112 /* 113 * open based on overall operation mode 114 */ 115 switch (act) { 116 case LIST: 117 case EXTRACT: 118 if (name == NULL) { 119 arfd = STDIN_FILENO; 120 arcname = stdn; 121 } else if ((arfd = open(name, EXT_MODE, DMOD)) < 0) 122 syswarn(0, errno, "Failed open to read on %s", name); 123 if (arfd != -1 && gzip_program != NULL) 124 ar_start_gzip(arfd, gzip_program, 0); 125 break; 126 case ARCHIVE: 127 if (name == NULL) { 128 arfd = STDOUT_FILENO; 129 arcname = stdo; 130 } else if ((arfd = open(name, AR_MODE, DMOD)) < 0) 131 syswarn(0, errno, "Failed open to write on %s", name); 132 else 133 can_unlnk = 1; 134 if (arfd != -1 && gzip_program != NULL) 135 ar_start_gzip(arfd, gzip_program, 1); 136 break; 137 case APPND: 138 if (name == NULL) { 139 arfd = STDOUT_FILENO; 140 arcname = stdo; 141 } else if ((arfd = open(name, APP_MODE, DMOD)) < 0) 142 syswarn(0, errno, "Failed open to read/write on %s", 143 name); 144 break; 145 case COPY: 146 /* 147 * arfd not used in COPY mode 148 */ 149 arcname = none; 150 lstrval = 1; 151 return(0); 152 } 153 if (arfd < 0) 154 return(-1); 155 156 if (chdname != NULL) 157 if (chdir(chdname) != 0) { 158 syswarn(1, errno, "Failed chdir to %s", chdname); 159 return(-1); 160 } 161 /* 162 * set up is based on device type 163 */ 164 if (fstat(arfd, &arsb) < 0) { 165 syswarn(0, errno, "Failed stat on %s", arcname); 166 (void)close(arfd); 167 arfd = -1; 168 can_unlnk = 0; 169 return(-1); 170 } 171 if (S_ISDIR(arsb.st_mode)) { 172 paxwarn(0, "Cannot write an archive on top of a directory %s", 173 arcname); 174 (void)close(arfd); 175 arfd = -1; 176 can_unlnk = 0; 177 return(-1); 178 } 179 180 if (S_ISCHR(arsb.st_mode)) 181 artyp = ioctl(arfd, MTIOCGET, &mb) ? ISCHR : ISTAPE; 182 else if (S_ISBLK(arsb.st_mode)) 183 artyp = ISBLK; 184 else if ((lseek(arfd, (off_t)0L, SEEK_CUR) == -1) && (errno == ESPIPE)) 185 artyp = ISPIPE; 186 else 187 artyp = ISREG; 188 189 /* 190 * make sure we beyond any doubt that we only can unlink regular files 191 * we created 192 */ 193 if (artyp != ISREG) 194 can_unlnk = 0; 195 /* 196 * if we are writing, we are done 197 */ 198 if (act == ARCHIVE) { 199 blksz = rdblksz = wrblksz; 200 lstrval = 1; 201 return(0); 202 } 203 204 /* 205 * set default blksz on read. APPNDs writes rdblksz on the last volume 206 * On all new archive volumes, we shift to wrblksz (if the user 207 * specified one, otherwize we will continue to use rdblksz). We 208 * must to set blocksize based on what kind of device the archive is 209 * stored. 210 */ 211 switch(artyp) { 212 case ISTAPE: 213 /* 214 * Tape drives come in at least two flavors. Those that support 215 * variable sized records and those that have fixed sized 216 * records. They must be treated differently. For tape drives 217 * that support variable sized records, we must make large 218 * reads to make sure we get the entire record, otherwise we 219 * will just get the first part of the record (up to size we 220 * asked). Tapes with fixed sized records may or may not return 221 * multiple records in a single read. We really do not care 222 * what the physical record size is UNLESS we are going to 223 * append. (We will need the physical block size to rewrite 224 * the trailer). Only when we are appending do we go to the 225 * effort to figure out the true PHYSICAL record size. 226 */ 227 blksz = rdblksz = MAXBLK; 228 break; 229 case ISPIPE: 230 case ISBLK: 231 case ISCHR: 232 /* 233 * Blocksize is not a major issue with these devices (but must 234 * be kept a multiple of 512). If the user specified a write 235 * block size, we use that to read. Under append, we must 236 * always keep blksz == rdblksz. Otherwise we go ahead and use 237 * the device optimal blocksize as (and if) returned by stat 238 * and if it is within pax specs. 239 */ 240 if ((act == APPND) && wrblksz) { 241 blksz = rdblksz = wrblksz; 242 break; 243 } 244 245 if ((arsb.st_blksize > 0) && (arsb.st_blksize < MAXBLK) && 246 ((arsb.st_blksize % BLKMULT) == 0)) 247 rdblksz = arsb.st_blksize; 248 else 249 rdblksz = DEVBLK; 250 /* 251 * For performance go for large reads when we can without harm 252 */ 253 if ((act == APPND) || (artyp == ISCHR)) 254 blksz = rdblksz; 255 else 256 blksz = MAXBLK; 257 break; 258 case ISREG: 259 /* 260 * if the user specified wrblksz works, use it. Under appends 261 * we must always keep blksz == rdblksz 262 */ 263 if ((act == APPND) && wrblksz && ((arsb.st_size%wrblksz)==0)){ 264 blksz = rdblksz = wrblksz; 265 break; 266 } 267 /* 268 * See if we can find the blocking factor from the file size 269 */ 270 for (rdblksz = MAXBLK; rdblksz > 0; rdblksz -= BLKMULT) 271 if ((arsb.st_size % rdblksz) == 0) 272 break; 273 /* 274 * When we cannot find a match, we may have a flawed archive. 275 */ 276 if (rdblksz <= 0) 277 rdblksz = FILEBLK; 278 /* 279 * for performance go for large reads when we can 280 */ 281 if (act == APPND) 282 blksz = rdblksz; 283 else 284 blksz = MAXBLK; 285 break; 286 default: 287 /* 288 * should never happen, worse case, slow... 289 */ 290 blksz = rdblksz = BLKMULT; 291 break; 292 } 293 lstrval = 1; 294 return(0); 295 } 296 297 /* 298 * ar_close() 299 * closes archive device, increments volume number, and prints i/o summary 300 */ 301 void 302 ar_close(void) 303 { 304 305 if (arfd < 0) { 306 did_io = io_ok = flcnt = 0; 307 return; 308 } 309 310 /* 311 * Close archive file. This may take a LONG while on tapes (we may be 312 * forced to wait for the rewind to complete) so tell the user what is 313 * going on (this avoids the user hitting control-c thinking pax is 314 * broken). 315 */ 316 if (vflag && (artyp == ISTAPE)) { 317 if (vfpart) 318 (void)putc('\n', listf); 319 (void)fprintf(listf, 320 "%s: Waiting for tape drive close to complete...", 321 argv0); 322 (void)fflush(listf); 323 } 324 325 /* 326 * if nothing was written to the archive (and we created it), we remove 327 * it 328 */ 329 if (can_unlnk && (fstat(arfd, &arsb) == 0) && (S_ISREG(arsb.st_mode)) && 330 (arsb.st_size == 0)) { 331 (void)unlink(arcname); 332 can_unlnk = 0; 333 } 334 335 /* 336 * for a quick extract/list, pax frequently exits before the child 337 * process is done 338 */ 339 if ((act == LIST || act == EXTRACT) && nflag && zpid > 0) { 340 int status; 341 kill(zpid, SIGINT); 342 waitpid(zpid, &status, 0); 343 } 344 345 (void)close(arfd); 346 347 if (vflag && (artyp == ISTAPE)) { 348 (void)fputs("done.\n", listf); 349 vfpart = 0; 350 (void)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 (void)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 # ifdef NET2_STAT 387 (void)fprintf(listf, "%s: unknown format, %lu bytes skipped.\n", 388 argv0, rdcnt); 389 # else 390 (void)fprintf(listf, "%s: unknown format, %ju bytes skipped.\n", 391 argv0, (uintmax_t)rdcnt); 392 # endif 393 (void)fflush(listf); 394 flcnt = 0; 395 return; 396 } 397 398 if (strcmp(NM_CPIO, argv0) == 0) 399 (void)fprintf(listf, "%llu blocks\n", 400 (unsigned long long)((rdcnt ? rdcnt : wrcnt) / 5120)); 401 else if (strcmp(NM_TAR, argv0) != 0) 402 (void)fprintf(listf, 403 # ifdef NET2_STAT 404 "%s: %s vol %d, %lu files, %lu bytes read, %lu bytes written.\n", 405 argv0, frmt->name, arvol-1, flcnt, rdcnt, wrcnt); 406 # else 407 "%s: %s vol %d, %ju files, %ju bytes read, %ju bytes written.\n", 408 argv0, frmt->name, arvol-1, (uintmax_t)flcnt, 409 (uintmax_t)rdcnt, (uintmax_t)wrcnt); 410 # endif 411 (void)fflush(listf); 412 flcnt = 0; 413 } 414 415 /* 416 * ar_drain() 417 * drain any archive format independent padding from an archive read 418 * from a socket or a pipe. This is to prevent the process on the 419 * other side of the pipe from getting a SIGPIPE (pax will stop 420 * reading an archive once a format dependent trailer is detected). 421 */ 422 void 423 ar_drain(void) 424 { 425 int res; 426 char drbuf[MAXBLK]; 427 428 /* 429 * we only drain from a pipe/socket. Other devices can be closed 430 * without reading up to end of file. We sure hope that pipe is closed 431 * on the other side so we will get an EOF. 432 */ 433 if ((artyp != ISPIPE) || (lstrval <= 0)) 434 return; 435 436 /* 437 * keep reading until pipe is drained 438 */ 439 while ((res = read(arfd, drbuf, sizeof(drbuf))) > 0) 440 ; 441 lstrval = res; 442 } 443 444 /* 445 * ar_set_wr() 446 * Set up device right before switching from read to write in an append. 447 * device dependent code (if required) to do this should be added here. 448 * For all archive devices we are already positioned at the place we want 449 * to start writing when this routine is called. 450 * Return: 451 * 0 if all ready to write, -1 otherwise 452 */ 453 454 int 455 ar_set_wr(void) 456 { 457 off_t cpos; 458 459 /* 460 * we must make sure the trailer is rewritten on append, ar_next() 461 * will stop us if the archive containing the trailer was not written 462 */ 463 wr_trail = 0; 464 465 /* 466 * Add any device dependent code as required here 467 */ 468 if (artyp != ISREG) 469 return(0); 470 /* 471 * Ok we have an archive in a regular file. If we were rewriting a 472 * file, we must get rid of all the stuff after the current offset 473 * (it was not written by pax). 474 */ 475 if (((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) || 476 (ftruncate(arfd, cpos) < 0)) { 477 syswarn(1, errno, "Unable to truncate archive file"); 478 return(-1); 479 } 480 return(0); 481 } 482 483 /* 484 * ar_app_ok() 485 * check if the last volume in the archive allows appends. We cannot check 486 * this until we are ready to write since there is no spec that says all 487 * volumes in a single archive have to be of the same type... 488 * Return: 489 * 0 if we can append, -1 otherwise. 490 */ 491 492 int 493 ar_app_ok(void) 494 { 495 if (artyp == ISPIPE) { 496 paxwarn(1, "Cannot append to an archive obtained from a pipe."); 497 return(-1); 498 } 499 500 if (!invld_rec) 501 return(0); 502 paxwarn(1,"Cannot append, device record size %d does not support %s spec", 503 rdblksz, argv0); 504 return(-1); 505 } 506 507 /* 508 * ar_read() 509 * read up to a specified number of bytes from the archive into the 510 * supplied buffer. When dealing with tapes we may not always be able to 511 * read what we want. 512 * Return: 513 * Number of bytes in buffer. 0 for end of file, -1 for a read error. 514 */ 515 516 int 517 ar_read(char *buf, int cnt) 518 { 519 int res = 0; 520 521 /* 522 * if last i/o was in error, no more reads until reset or new volume 523 */ 524 if (lstrval <= 0) 525 return(lstrval); 526 527 /* 528 * how we read must be based on device type 529 */ 530 switch (artyp) { 531 case ISTAPE: 532 if ((res = read(arfd, buf, cnt)) > 0) { 533 /* 534 * CAUTION: tape systems may not always return the same 535 * sized records so we leave blksz == MAXBLK. The 536 * physical record size that a tape drive supports is 537 * very hard to determine in a uniform and portable 538 * manner. 539 */ 540 io_ok = 1; 541 if (res != rdblksz) { 542 /* 543 * Record size changed. If this is happens on 544 * any record after the first, we probably have 545 * a tape drive which has a fixed record size 546 * we are getting multiple records in a single 547 * read). Watch out for record blocking that 548 * violates pax spec (must be a multiple of 549 * BLKMULT). 550 */ 551 rdblksz = res; 552 if (rdblksz % BLKMULT) 553 invld_rec = 1; 554 } 555 return(res); 556 } 557 break; 558 case ISREG: 559 case ISBLK: 560 case ISCHR: 561 case ISPIPE: 562 default: 563 /* 564 * Files are so easy to deal with. These other things cannot 565 * be trusted at all. So when we are dealing with character 566 * devices and pipes we just take what they have ready for us 567 * and return. Trying to do anything else with them runs the 568 * risk of failure. 569 */ 570 if ((res = read(arfd, buf, cnt)) > 0) { 571 io_ok = 1; 572 return(res); 573 } 574 break; 575 } 576 577 /* 578 * We are in trouble at this point, something is broken... 579 */ 580 lstrval = res; 581 if (res < 0) 582 syswarn(1, errno, "Failed read on archive volume %d", arvol); 583 else 584 paxwarn(0, "End of archive volume %d reached", arvol); 585 return(res); 586 } 587 588 /* 589 * ar_write() 590 * Write a specified number of bytes in supplied buffer to the archive 591 * device so it appears as a single "block". Deals with errors and tries 592 * to recover when faced with short writes. 593 * Return: 594 * Number of bytes written. 0 indicates end of volume reached and with no 595 * flaws (as best that can be detected). A -1 indicates an unrecoverable 596 * error in the archive occured. 597 */ 598 599 int 600 ar_write(char *buf, int bsz) 601 { 602 int res; 603 off_t cpos; 604 605 /* 606 * do not allow pax to create a "bad" archive. Once a write fails on 607 * an archive volume prevent further writes to it. 608 */ 609 if (lstrval <= 0) 610 return(lstrval); 611 612 if ((res = write(arfd, buf, bsz)) == bsz) { 613 wr_trail = 1; 614 io_ok = 1; 615 return(bsz); 616 } 617 /* 618 * write broke, see what we can do with it. We try to send any partial 619 * writes that may violate pax spec to the next archive volume. 620 */ 621 if (res < 0) 622 lstrval = res; 623 else 624 lstrval = 0; 625 626 switch (artyp) { 627 case ISREG: 628 if ((res > 0) && (res % BLKMULT)) { 629 /* 630 * try to fix up partial writes which are not BLKMULT 631 * in size by forcing the runt record to next archive 632 * volume 633 */ 634 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 635 break; 636 cpos -= (off_t)res; 637 if (ftruncate(arfd, cpos) < 0) 638 break; 639 res = lstrval = 0; 640 break; 641 } 642 if (res >= 0) 643 break; 644 /* 645 * if file is out of space, handle it like a return of 0 646 */ 647 if ((errno == ENOSPC) || (errno == EFBIG) || (errno == EDQUOT)) 648 res = lstrval = 0; 649 break; 650 case ISTAPE: 651 case ISCHR: 652 case ISBLK: 653 if (res >= 0) 654 break; 655 if (errno == EACCES) { 656 paxwarn(0, "Write failed, archive is write protected."); 657 res = lstrval = 0; 658 return(0); 659 } 660 /* 661 * see if we reached the end of media, if so force a change to 662 * the next volume 663 */ 664 if ((errno == ENOSPC) || (errno == EIO) || (errno == ENXIO)) 665 res = lstrval = 0; 666 break; 667 case ISPIPE: 668 default: 669 /* 670 * we cannot fix errors to these devices 671 */ 672 break; 673 } 674 675 /* 676 * Better tell the user the bad news... 677 * if this is a block aligned archive format, we may have a bad archive 678 * if the format wants the header to start at a BLKMULT boundary. While 679 * we can deal with the mis-aligned data, it violates spec and other 680 * archive readers will likely fail. if the format is not block 681 * aligned, the user may be lucky (and the archive is ok). 682 */ 683 if (res >= 0) { 684 if (res > 0) 685 wr_trail = 1; 686 io_ok = 1; 687 } 688 689 /* 690 * If we were trying to rewrite the trailer and it didn't work, we 691 * must quit right away. 692 */ 693 if (!wr_trail && (res <= 0)) { 694 paxwarn(1,"Unable to append, trailer re-write failed. Quitting."); 695 return(res); 696 } 697 698 if (res == 0) 699 paxwarn(0, "End of archive volume %d reached", arvol); 700 else if (res < 0) 701 syswarn(1, errno, "Failed write to archive volume: %d", arvol); 702 else if (!frmt->blkalgn || ((res % frmt->blkalgn) == 0)) 703 paxwarn(0,"WARNING: partial archive write. Archive MAY BE FLAWED"); 704 else 705 paxwarn(1,"WARNING: partial archive write. Archive IS FLAWED"); 706 return(res); 707 } 708 709 /* 710 * ar_rdsync() 711 * Try to move past a bad spot on a flawed archive as needed to continue 712 * I/O. Clears error flags to allow I/O to continue. 713 * Return: 714 * 0 when ok to try i/o again, -1 otherwise. 715 */ 716 717 int 718 ar_rdsync(void) 719 { 720 long fsbz; 721 off_t cpos; 722 off_t mpos; 723 struct mtop mb; 724 725 /* 726 * Fail resync attempts at user request (done) or this is going to be 727 * an update/append to an existing archive. If last i/o hit media end, 728 * we need to go to the next volume not try a resync. 729 */ 730 if ((done > 0) || (lstrval == 0)) 731 return(-1); 732 733 if ((act == APPND) || (act == ARCHIVE)) { 734 paxwarn(1, "Cannot allow updates to an archive with flaws."); 735 return(-1); 736 } 737 if (io_ok) 738 did_io = 1; 739 740 switch(artyp) { 741 case ISTAPE: 742 /* 743 * if the last i/o was a successful data transfer, we assume 744 * the fault is just a bad record on the tape that we are now 745 * past. If we did not get any data since the last resync try 746 * to move the tape forward one PHYSICAL record past any 747 * damaged tape section. Some tape drives are stubborn and need 748 * to be pushed. 749 */ 750 if (io_ok) { 751 io_ok = 0; 752 lstrval = 1; 753 break; 754 } 755 mb.mt_op = MTFSR; 756 mb.mt_count = 1; 757 if (ioctl(arfd, MTIOCTOP, &mb) < 0) 758 break; 759 lstrval = 1; 760 break; 761 case ISREG: 762 case ISCHR: 763 case ISBLK: 764 /* 765 * try to step over the bad part of the device. 766 */ 767 io_ok = 0; 768 if (((fsbz = arsb.st_blksize) <= 0) || (artyp != ISREG)) 769 fsbz = BLKMULT; 770 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 771 break; 772 mpos = fsbz - (cpos % (off_t)fsbz); 773 if (lseek(arfd, mpos, SEEK_CUR) < 0) 774 break; 775 lstrval = 1; 776 break; 777 case ISPIPE: 778 default: 779 /* 780 * cannot recover on these archive device types 781 */ 782 io_ok = 0; 783 break; 784 } 785 if (lstrval <= 0) { 786 paxwarn(1, "Unable to recover from an archive read failure."); 787 return(-1); 788 } 789 paxwarn(0, "Attempting to recover from an archive read failure."); 790 return(0); 791 } 792 793 /* 794 * ar_fow() 795 * Move the I/O position within the archive foward the specified number of 796 * bytes as supported by the device. If we cannot move the requested 797 * number of bytes, return the actual number of bytes moved in skipped. 798 * Return: 799 * 0 if moved the requested distance, -1 on complete failure, 1 on 800 * partial move (the amount moved is in skipped) 801 */ 802 803 int 804 ar_fow(off_t sksz, off_t *skipped) 805 { 806 off_t cpos; 807 off_t mpos; 808 809 *skipped = 0; 810 if (sksz <= 0) 811 return(0); 812 813 /* 814 * we cannot move foward at EOF or error 815 */ 816 if (lstrval <= 0) 817 return(lstrval); 818 819 /* 820 * Safer to read forward on devices where it is hard to find the end of 821 * the media without reading to it. With tapes we cannot be sure of the 822 * number of physical blocks to skip (we do not know physical block 823 * size at this point), so we must only read foward on tapes! 824 */ 825 if (artyp != ISREG) 826 return(0); 827 828 /* 829 * figure out where we are in the archive 830 */ 831 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) >= 0) { 832 /* 833 * we can be asked to move farther than there are bytes in this 834 * volume, if so, just go to file end and let normal buf_fill() 835 * deal with the end of file (it will go to next volume by 836 * itself) 837 */ 838 if ((mpos = cpos + sksz) > arsb.st_size) { 839 *skipped = arsb.st_size - cpos; 840 mpos = arsb.st_size; 841 } else 842 *skipped = sksz; 843 if (lseek(arfd, mpos, SEEK_SET) >= 0) 844 return(0); 845 } 846 syswarn(1, errno, "Forward positioning operation on archive failed"); 847 lstrval = -1; 848 return(-1); 849 } 850 851 /* 852 * ar_rev() 853 * move the i/o position within the archive backwards the specified byte 854 * count as supported by the device. With tapes drives we RESET rdblksz to 855 * the PHYSICAL blocksize. 856 * NOTE: We should only be called to move backwards so we can rewrite the 857 * last records (the trailer) of an archive (APPEND). 858 * Return: 859 * 0 if moved the requested distance, -1 on complete failure 860 */ 861 862 int 863 ar_rev(off_t sksz) 864 { 865 off_t cpos; 866 struct mtop mb; 867 int phyblk; 868 869 /* 870 * make sure we do not have try to reverse on a flawed archive 871 */ 872 if (lstrval < 0) 873 return(lstrval); 874 875 switch(artyp) { 876 case ISPIPE: 877 if (sksz <= 0) 878 break; 879 /* 880 * cannot go backwards on these critters 881 */ 882 paxwarn(1, "Reverse positioning on pipes is not supported."); 883 lstrval = -1; 884 return(-1); 885 case ISREG: 886 case ISBLK: 887 case ISCHR: 888 default: 889 if (sksz <= 0) 890 break; 891 892 /* 893 * For things other than files, backwards movement has a very 894 * high probability of failure as we really do not know the 895 * true attributes of the device we are talking to (the device 896 * may not even have the ability to lseek() in any direction). 897 * First we figure out where we are in the archive. 898 */ 899 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) { 900 syswarn(1, errno, 901 "Unable to obtain current archive byte offset"); 902 lstrval = -1; 903 return(-1); 904 } 905 906 /* 907 * we may try to go backwards past the start when the archive 908 * is only a single record. If this hapens and we are on a 909 * multi volume archive, we need to go to the end of the 910 * previous volume and continue our movement backwards from 911 * there. 912 */ 913 if ((cpos -= sksz) < (off_t)0L) { 914 if (arvol > 1) { 915 /* 916 * this should never happen 917 */ 918 paxwarn(1,"Reverse position on previous volume."); 919 lstrval = -1; 920 return(-1); 921 } 922 cpos = (off_t)0L; 923 } 924 if (lseek(arfd, cpos, SEEK_SET) < 0) { 925 syswarn(1, errno, "Unable to seek archive backwards"); 926 lstrval = -1; 927 return(-1); 928 } 929 break; 930 case ISTAPE: 931 /* 932 * Calculate and move the proper number of PHYSICAL tape 933 * blocks. If the sksz is not an even multiple of the physical 934 * tape size, we cannot do the move (this should never happen). 935 * (We also cannot handler trailers spread over two vols). 936 * get_phys() also makes sure we are in front of the filemark. 937 */ 938 if ((phyblk = get_phys()) <= 0) { 939 lstrval = -1; 940 return(-1); 941 } 942 943 /* 944 * make sure future tape reads only go by physical tape block 945 * size (set rdblksz to the real size). 946 */ 947 rdblksz = phyblk; 948 949 /* 950 * if no movement is required, just return (we must be after 951 * get_phys() so the physical blocksize is properly set) 952 */ 953 if (sksz <= 0) 954 break; 955 956 /* 957 * ok we have to move. Make sure the tape drive can do it. 958 */ 959 if (sksz % phyblk) { 960 paxwarn(1, 961 "Tape drive unable to backspace requested amount"); 962 lstrval = -1; 963 return(-1); 964 } 965 966 /* 967 * move backwards the requested number of bytes 968 */ 969 mb.mt_op = MTBSR; 970 mb.mt_count = sksz/phyblk; 971 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 972 syswarn(1,errno, "Unable to backspace tape %d blocks.", 973 mb.mt_count); 974 lstrval = -1; 975 return(-1); 976 } 977 break; 978 } 979 lstrval = 1; 980 return(0); 981 } 982 983 /* 984 * get_phys() 985 * Determine the physical block size on a tape drive. We need the physical 986 * block size so we know how many bytes we skip over when we move with 987 * mtio commands. We also make sure we are BEFORE THE TAPE FILEMARK when 988 * return. 989 * This is one really SLOW routine... 990 * Return: 991 * physical block size if ok (ok > 0), -1 otherwise 992 */ 993 994 static int 995 get_phys(void) 996 { 997 int padsz = 0; 998 int res; 999 int phyblk; 1000 struct mtop mb; 1001 char scbuf[MAXBLK]; 1002 1003 /* 1004 * move to the file mark, and then back up one record and read it. 1005 * this should tell us the physical record size the tape is using. 1006 */ 1007 if (lstrval == 1) { 1008 /* 1009 * we know we are at file mark when we get back a 0 from 1010 * read() 1011 */ 1012 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1013 padsz += res; 1014 if (res < 0) { 1015 syswarn(1, errno, "Unable to locate tape filemark."); 1016 return(-1); 1017 } 1018 } 1019 1020 /* 1021 * move backwards over the file mark so we are at the end of the 1022 * last record. 1023 */ 1024 mb.mt_op = MTBSF; 1025 mb.mt_count = 1; 1026 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1027 syswarn(1, errno, "Unable to backspace over tape filemark."); 1028 return(-1); 1029 } 1030 1031 /* 1032 * move backwards so we are in front of the last record and read it to 1033 * get physical tape blocksize. 1034 */ 1035 mb.mt_op = MTBSR; 1036 mb.mt_count = 1; 1037 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1038 syswarn(1, errno, "Unable to backspace over last tape block."); 1039 return(-1); 1040 } 1041 if ((phyblk = read(arfd, scbuf, sizeof(scbuf))) <= 0) { 1042 syswarn(1, errno, "Cannot determine archive tape blocksize."); 1043 return(-1); 1044 } 1045 1046 /* 1047 * read foward to the file mark, then back up in front of the filemark 1048 * (this is a bit paranoid, but should be safe to do). 1049 */ 1050 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1051 ; 1052 if (res < 0) { 1053 syswarn(1, errno, "Unable to locate tape filemark."); 1054 return(-1); 1055 } 1056 mb.mt_op = MTBSF; 1057 mb.mt_count = 1; 1058 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1059 syswarn(1, errno, "Unable to backspace over tape filemark."); 1060 return(-1); 1061 } 1062 1063 /* 1064 * set lstrval so we know that the filemark has not been seen 1065 */ 1066 lstrval = 1; 1067 1068 /* 1069 * return if there was no padding 1070 */ 1071 if (padsz == 0) 1072 return(phyblk); 1073 1074 /* 1075 * make sure we can move backwards over the padding. (this should 1076 * never fail). 1077 */ 1078 if (padsz % phyblk) { 1079 paxwarn(1, "Tape drive unable to backspace requested amount"); 1080 return(-1); 1081 } 1082 1083 /* 1084 * move backwards over the padding so the head is where it was when 1085 * we were first called (if required). 1086 */ 1087 mb.mt_op = MTBSR; 1088 mb.mt_count = padsz/phyblk; 1089 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1090 syswarn(1,errno,"Unable to backspace tape over %d pad blocks", 1091 mb.mt_count); 1092 return(-1); 1093 } 1094 return(phyblk); 1095 } 1096 1097 /* 1098 * ar_next() 1099 * prompts the user for the next volume in this archive. For some devices 1100 * we may allow the media to be changed. Otherwise a new archive is 1101 * prompted for. By pax spec, if there is no controlling tty or an eof is 1102 * read on tty input, we must quit pax. 1103 * Return: 1104 * 0 when ready to continue, -1 when all done 1105 */ 1106 1107 int 1108 ar_next(void) 1109 { 1110 char buf[PAXPATHLEN+2]; 1111 static int freeit = 0; 1112 sigset_t o_mask; 1113 1114 /* 1115 * WE MUST CLOSE THE DEVICE. A lot of devices must see last close, (so 1116 * things like writing EOF etc will be done) (Watch out ar_close() can 1117 * also be called via a signal handler, so we must prevent a race. 1118 */ 1119 if (sigprocmask(SIG_BLOCK, &s_mask, &o_mask) < 0) 1120 syswarn(0, errno, "Unable to set signal mask"); 1121 ar_close(); 1122 if (sigprocmask(SIG_SETMASK, &o_mask, NULL) < 0) 1123 syswarn(0, errno, "Unable to restore signal mask"); 1124 1125 if (done || !wr_trail || strcmp(NM_TAR, argv0) == 0) 1126 return(-1); 1127 1128 tty_prnt("\nATTENTION! %s archive volume change required.\n", argv0); 1129 1130 /* 1131 * if i/o is on stdin or stdout, we cannot reopen it (we do not know 1132 * the name), the user will be forced to type it in. 1133 */ 1134 if (strcmp(arcname, stdo) && strcmp(arcname, stdn) && (artyp != ISREG) 1135 && (artyp != ISPIPE)) { 1136 if (artyp == ISTAPE) { 1137 tty_prnt("%s ready for archive tape volume: %d\n", 1138 arcname, arvol); 1139 tty_prnt("Load the NEXT TAPE on the tape drive"); 1140 } else { 1141 tty_prnt("%s ready for archive volume: %d\n", 1142 arcname, arvol); 1143 tty_prnt("Load the NEXT STORAGE MEDIA (if required)"); 1144 } 1145 1146 if ((act == ARCHIVE) || (act == APPND)) 1147 tty_prnt(" and make sure it is WRITE ENABLED.\n"); 1148 else 1149 tty_prnt("\n"); 1150 1151 for(;;) { 1152 tty_prnt("Type \"y\" to continue, \".\" to quit %s,", 1153 argv0); 1154 tty_prnt(" or \"s\" to switch to new device.\nIf you"); 1155 tty_prnt(" cannot change storage media, type \"s\"\n"); 1156 tty_prnt("Is the device ready and online? > "); 1157 1158 if ((tty_read(buf,sizeof(buf))<0) || !strcmp(buf,".")){ 1159 done = 1; 1160 lstrval = -1; 1161 tty_prnt("Quitting %s!\n", argv0); 1162 vfpart = 0; 1163 return(-1); 1164 } 1165 1166 if ((buf[0] == '\0') || (buf[1] != '\0')) { 1167 tty_prnt("%s unknown command, try again\n",buf); 1168 continue; 1169 } 1170 1171 switch (buf[0]) { 1172 case 'y': 1173 case 'Y': 1174 /* 1175 * we are to continue with the same device 1176 */ 1177 if (ar_open(arcname) >= 0) 1178 return(0); 1179 tty_prnt("Cannot re-open %s, try again\n", 1180 arcname); 1181 continue; 1182 case 's': 1183 case 'S': 1184 /* 1185 * user wants to open a different device 1186 */ 1187 tty_prnt("Switching to a different archive\n"); 1188 break; 1189 default: 1190 tty_prnt("%s unknown command, try again\n",buf); 1191 continue; 1192 } 1193 break; 1194 } 1195 } else 1196 tty_prnt("Ready for archive volume: %d\n", arvol); 1197 1198 /* 1199 * have to go to a different archive 1200 */ 1201 for (;;) { 1202 tty_prnt("Input archive name or \".\" to quit %s.\n", argv0); 1203 tty_prnt("Archive name > "); 1204 1205 if ((tty_read(buf, sizeof(buf)) < 0) || !strcmp(buf, ".")) { 1206 done = 1; 1207 lstrval = -1; 1208 tty_prnt("Quitting %s!\n", argv0); 1209 vfpart = 0; 1210 return(-1); 1211 } 1212 if (buf[0] == '\0') { 1213 tty_prnt("Empty file name, try again\n"); 1214 continue; 1215 } 1216 if (!strcmp(buf, "..")) { 1217 tty_prnt("Illegal file name: .. try again\n"); 1218 continue; 1219 } 1220 if (strlen(buf) > PAXPATHLEN) { 1221 tty_prnt("File name too long, try again\n"); 1222 continue; 1223 } 1224 1225 /* 1226 * try to open new archive 1227 */ 1228 if (ar_open(buf) >= 0) { 1229 if (freeit) { 1230 (void)free((char *)(uintptr_t)arcname); 1231 freeit = 0; 1232 } 1233 if ((arcname = strdup(buf)) == NULL) { 1234 done = 1; 1235 lstrval = -1; 1236 paxwarn(0, "Cannot save archive name."); 1237 return(-1); 1238 } 1239 freeit = 1; 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