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