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 1.5 2003/09/28 14:39:14 hmp 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 (void)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 /* 157 * set up is based on device type 158 */ 159 if (fstat(arfd, &arsb) < 0) { 160 syswarn(0, errno, "Failed stat on %s", arcname); 161 (void)close(arfd); 162 arfd = -1; 163 can_unlnk = 0; 164 return(-1); 165 } 166 if (S_ISDIR(arsb.st_mode)) { 167 paxwarn(0, "Cannot write an archive on top of a directory %s", 168 arcname); 169 (void)close(arfd); 170 arfd = -1; 171 can_unlnk = 0; 172 return(-1); 173 } 174 175 if (S_ISCHR(arsb.st_mode)) 176 artyp = ioctl(arfd, MTIOCGET, &mb) ? ISCHR : ISTAPE; 177 else if (S_ISBLK(arsb.st_mode)) 178 artyp = ISBLK; 179 else if ((lseek(arfd, (off_t)0L, SEEK_CUR) == -1) && (errno == ESPIPE)) 180 artyp = ISPIPE; 181 else 182 artyp = ISREG; 183 184 /* 185 * make sure we beyond any doubt that we only can unlink regular files 186 * we created 187 */ 188 if (artyp != ISREG) 189 can_unlnk = 0; 190 /* 191 * if we are writing, we are done 192 */ 193 if (act == ARCHIVE) { 194 blksz = rdblksz = wrblksz; 195 lstrval = 1; 196 return(0); 197 } 198 199 /* 200 * set default blksz on read. APPNDs writes rdblksz on the last volume 201 * On all new archive volumes, we shift to wrblksz (if the user 202 * specified one, otherwize we will continue to use rdblksz). We 203 * must to set blocksize based on what kind of device the archive is 204 * stored. 205 */ 206 switch(artyp) { 207 case ISTAPE: 208 /* 209 * Tape drives come in at least two flavors. Those that support 210 * variable sized records and those that have fixed sized 211 * records. They must be treated differently. For tape drives 212 * that support variable sized records, we must make large 213 * reads to make sure we get the entire record, otherwise we 214 * will just get the first part of the record (up to size we 215 * asked). Tapes with fixed sized records may or may not return 216 * multiple records in a single read. We really do not care 217 * what the physical record size is UNLESS we are going to 218 * append. (We will need the physical block size to rewrite 219 * the trailer). Only when we are appending do we go to the 220 * effort to figure out the true PHYSICAL record size. 221 */ 222 blksz = rdblksz = MAXBLK; 223 break; 224 case ISPIPE: 225 case ISBLK: 226 case ISCHR: 227 /* 228 * Blocksize is not a major issue with these devices (but must 229 * be kept a multiple of 512). If the user specified a write 230 * block size, we use that to read. Under append, we must 231 * always keep blksz == rdblksz. Otherwise we go ahead and use 232 * the device optimal blocksize as (and if) returned by stat 233 * and if it is within pax specs. 234 */ 235 if ((act == APPND) && wrblksz) { 236 blksz = rdblksz = wrblksz; 237 break; 238 } 239 240 if ((arsb.st_blksize > 0) && (arsb.st_blksize < MAXBLK) && 241 ((arsb.st_blksize % BLKMULT) == 0)) 242 rdblksz = arsb.st_blksize; 243 else 244 rdblksz = DEVBLK; 245 /* 246 * For performance go for large reads when we can without harm 247 */ 248 if ((act == APPND) || (artyp == ISCHR)) 249 blksz = rdblksz; 250 else 251 blksz = MAXBLK; 252 break; 253 case ISREG: 254 /* 255 * if the user specified wrblksz works, use it. Under appends 256 * we must always keep blksz == rdblksz 257 */ 258 if ((act == APPND) && wrblksz && ((arsb.st_size%wrblksz)==0)){ 259 blksz = rdblksz = wrblksz; 260 break; 261 } 262 /* 263 * See if we can find the blocking factor from the file size 264 */ 265 for (rdblksz = MAXBLK; rdblksz > 0; rdblksz -= BLKMULT) 266 if ((arsb.st_size % rdblksz) == 0) 267 break; 268 /* 269 * When we cannot find a match, we may have a flawed archive. 270 */ 271 if (rdblksz <= 0) 272 rdblksz = FILEBLK; 273 /* 274 * for performance go for large reads when we can 275 */ 276 if (act == APPND) 277 blksz = rdblksz; 278 else 279 blksz = MAXBLK; 280 break; 281 default: 282 /* 283 * should never happen, worse case, slow... 284 */ 285 blksz = rdblksz = BLKMULT; 286 break; 287 } 288 lstrval = 1; 289 return(0); 290 } 291 292 /* 293 * ar_close() 294 * closes archive device, increments volume number, and prints i/o summary 295 */ 296 void 297 ar_close(void) 298 { 299 int status; 300 301 if (arfd < 0) { 302 did_io = io_ok = flcnt = 0; 303 return; 304 } 305 306 /* 307 * Close archive file. This may take a LONG while on tapes (we may be 308 * forced to wait for the rewind to complete) so tell the user what is 309 * going on (this avoids the user hitting control-c thinking pax is 310 * broken). 311 */ 312 if (vflag && (artyp == ISTAPE)) { 313 if (vfpart) 314 (void)putc('\n', listf); 315 (void)fprintf(listf, 316 "%s: Waiting for tape drive close to complete...", 317 argv0); 318 (void)fflush(listf); 319 } 320 321 /* 322 * if nothing was written to the archive (and we created it), we remove 323 * it 324 */ 325 if (can_unlnk && (fstat(arfd, &arsb) == 0) && (S_ISREG(arsb.st_mode)) && 326 (arsb.st_size == 0)) { 327 (void)unlink(arcname); 328 can_unlnk = 0; 329 } 330 331 /* 332 * for a quick extract/list, pax frequently exits before the child 333 * process is done 334 */ 335 if ((act == LIST || act == EXTRACT) && nflag && zpid > 0) 336 kill(zpid, SIGINT); 337 338 (void)close(arfd); 339 340 /* Do not exit before child to ensure data integrity */ 341 if (zpid > 0) 342 waitpid(zpid, &status, 0); 343 344 if (vflag && (artyp == ISTAPE)) { 345 (void)fputs("done.\n", listf); 346 vfpart = 0; 347 (void)fflush(listf); 348 } 349 arfd = -1; 350 351 if (!io_ok && !did_io) { 352 flcnt = 0; 353 return; 354 } 355 did_io = io_ok = 0; 356 357 /* 358 * The volume number is only increased when the last device has data 359 * and we have already determined the archive format. 360 */ 361 if (frmt != NULL) 362 ++arvol; 363 364 if (!vflag) { 365 flcnt = 0; 366 return; 367 } 368 369 /* 370 * Print out a summary of I/O for this archive volume. 371 */ 372 if (vfpart) { 373 (void)putc('\n', listf); 374 vfpart = 0; 375 } 376 377 /* 378 * If we have not determined the format yet, we just say how many bytes 379 * we have skipped over looking for a header to id. there is no way we 380 * could have written anything yet. 381 */ 382 if (frmt == NULL) { 383 # ifdef NET2_STAT 384 (void)fprintf(listf, "%s: unknown format, %lu bytes skipped.\n", 385 # else 386 (void)fprintf(listf, "%s: unknown format, %qu bytes skipped.\n", 387 # endif 388 argv0, rdcnt); 389 (void)fflush(listf); 390 flcnt = 0; 391 return; 392 } 393 394 if (strcmp(NM_CPIO, argv0) == 0) 395 (void)fprintf(listf, "%qu blocks\n", (rdcnt ? rdcnt : wrcnt) / 5120); 396 else if (strcmp(NM_TAR, argv0) != 0) 397 (void)fprintf(listf, 398 # ifdef NET2_STAT 399 "%s: %s vol %d, %lu files, %lu bytes read, %lu bytes written.\n", 400 # else 401 "%s: %s vol %d, %lu files, %qu bytes read, %qu bytes written.\n", 402 # endif 403 argv0, frmt->name, arvol-1, flcnt, rdcnt, wrcnt); 404 (void)fflush(listf); 405 flcnt = 0; 406 } 407 408 /* 409 * ar_drain() 410 * drain any archive format independent padding from an archive read 411 * from a socket or a pipe. This is to prevent the process on the 412 * other side of the pipe from getting a SIGPIPE (pax will stop 413 * reading an archive once a format dependent trailer is detected). 414 */ 415 void 416 ar_drain(void) 417 { 418 register int res; 419 char drbuf[MAXBLK]; 420 421 /* 422 * we only drain from a pipe/socket. Other devices can be closed 423 * without reading up to end of file. We sure hope that pipe is closed 424 * on the other side so we will get an EOF. 425 */ 426 if ((artyp != ISPIPE) || (lstrval <= 0)) 427 return; 428 429 /* 430 * keep reading until pipe is drained 431 */ 432 while ((res = read(arfd, drbuf, sizeof(drbuf))) > 0) 433 ; 434 lstrval = res; 435 } 436 437 /* 438 * ar_set_wr() 439 * Set up device right before switching from read to write in an append. 440 * device dependent code (if required) to do this should be added here. 441 * For all archive devices we are already positioned at the place we want 442 * to start writing when this routine is called. 443 * Return: 444 * 0 if all ready to write, -1 otherwise 445 */ 446 447 int 448 ar_set_wr(void) 449 { 450 off_t cpos; 451 452 /* 453 * we must make sure the trailer is rewritten on append, ar_next() 454 * will stop us if the archive containing the trailer was not written 455 */ 456 wr_trail = 0; 457 458 /* 459 * Add any device dependent code as required here 460 */ 461 if (artyp != ISREG) 462 return(0); 463 /* 464 * Ok we have an archive in a regular file. If we were rewriting a 465 * file, we must get rid of all the stuff after the current offset 466 * (it was not written by pax). 467 */ 468 if (((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) || 469 (ftruncate(arfd, cpos) < 0)) { 470 syswarn(1, errno, "Unable to truncate archive file"); 471 return(-1); 472 } 473 return(0); 474 } 475 476 /* 477 * ar_app_ok() 478 * check if the last volume in the archive allows appends. We cannot check 479 * this until we are ready to write since there is no spec that says all 480 * volumes in a single archive have to be of the same type... 481 * Return: 482 * 0 if we can append, -1 otherwise. 483 */ 484 485 int 486 ar_app_ok(void) 487 { 488 if (artyp == ISPIPE) { 489 paxwarn(1, "Cannot append to an archive obtained from a pipe."); 490 return(-1); 491 } 492 493 if (!invld_rec) 494 return(0); 495 paxwarn(1,"Cannot append, device record size %d does not support %s spec", 496 rdblksz, argv0); 497 return(-1); 498 } 499 500 /* 501 * ar_read() 502 * read up to a specified number of bytes from the archive into the 503 * supplied buffer. When dealing with tapes we may not always be able to 504 * read what we want. 505 * Return: 506 * Number of bytes in buffer. 0 for end of file, -1 for a read error. 507 */ 508 509 int 510 ar_read(register char *buf, register int cnt) 511 { 512 register int res = 0; 513 514 /* 515 * if last i/o was in error, no more reads until reset or new volume 516 */ 517 if (lstrval <= 0) 518 return(lstrval); 519 520 /* 521 * how we read must be based on device type 522 */ 523 switch (artyp) { 524 case ISTAPE: 525 if ((res = read(arfd, buf, cnt)) > 0) { 526 /* 527 * CAUTION: tape systems may not always return the same 528 * sized records so we leave blksz == MAXBLK. The 529 * physical record size that a tape drive supports is 530 * very hard to determine in a uniform and portable 531 * manner. 532 */ 533 io_ok = 1; 534 if (res != rdblksz) { 535 /* 536 * Record size changed. If this is happens on 537 * any record after the first, we probably have 538 * a tape drive which has a fixed record size 539 * we are getting multiple records in a single 540 * read). Watch out for record blocking that 541 * violates pax spec (must be a multiple of 542 * BLKMULT). 543 */ 544 rdblksz = res; 545 if (rdblksz % BLKMULT) 546 invld_rec = 1; 547 } 548 return(res); 549 } 550 break; 551 case ISREG: 552 case ISBLK: 553 case ISCHR: 554 case ISPIPE: 555 default: 556 /* 557 * Files are so easy to deal with. These other things cannot 558 * be trusted at all. So when we are dealing with character 559 * devices and pipes we just take what they have ready for us 560 * and return. Trying to do anything else with them runs the 561 * risk of failure. 562 */ 563 if ((res = read(arfd, buf, cnt)) > 0) { 564 io_ok = 1; 565 return(res); 566 } 567 break; 568 } 569 570 /* 571 * We are in trouble at this point, something is broken... 572 */ 573 lstrval = res; 574 if (res < 0) 575 syswarn(1, errno, "Failed read on archive volume %d", arvol); 576 else 577 paxwarn(0, "End of archive volume %d reached", arvol); 578 return(res); 579 } 580 581 /* 582 * ar_write() 583 * Write a specified number of bytes in supplied buffer to the archive 584 * device so it appears as a single "block". Deals with errors and tries 585 * to recover when faced with short writes. 586 * Return: 587 * Number of bytes written. 0 indicates end of volume reached and with no 588 * flaws (as best that can be detected). A -1 indicates an unrecoverable 589 * error in the archive occured. 590 */ 591 592 int 593 ar_write(register char *buf, register int bsz) 594 { 595 register int res; 596 off_t cpos; 597 598 /* 599 * do not allow pax to create a "bad" archive. Once a write fails on 600 * an archive volume prevent further writes to it. 601 */ 602 if (lstrval <= 0) 603 return(lstrval); 604 605 if ((res = write(arfd, buf, bsz)) == bsz) { 606 wr_trail = 1; 607 io_ok = 1; 608 return(bsz); 609 } 610 /* 611 * write broke, see what we can do with it. We try to send any partial 612 * writes that may violate pax spec to the next archive volume. 613 */ 614 if (res < 0) 615 lstrval = res; 616 else 617 lstrval = 0; 618 619 switch (artyp) { 620 case ISREG: 621 if ((res > 0) && (res % BLKMULT)) { 622 /* 623 * try to fix up partial writes which are not BLKMULT 624 * in size by forcing the runt record to next archive 625 * volume 626 */ 627 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 628 break; 629 cpos -= (off_t)res; 630 if (ftruncate(arfd, cpos) < 0) 631 break; 632 res = lstrval = 0; 633 break; 634 } 635 if (res >= 0) 636 break; 637 /* 638 * if file is out of space, handle it like a return of 0 639 */ 640 if ((errno == ENOSPC) || (errno == EFBIG) || (errno == EDQUOT)) 641 res = lstrval = 0; 642 break; 643 case ISTAPE: 644 case ISCHR: 645 case ISBLK: 646 if (res >= 0) 647 break; 648 if (errno == EACCES) { 649 paxwarn(0, "Write failed, archive is write protected."); 650 res = lstrval = 0; 651 return(0); 652 } 653 /* 654 * see if we reached the end of media, if so force a change to 655 * the next volume 656 */ 657 if ((errno == ENOSPC) || (errno == EIO) || (errno == ENXIO)) 658 res = lstrval = 0; 659 break; 660 case ISPIPE: 661 default: 662 /* 663 * we cannot fix errors to these devices 664 */ 665 break; 666 } 667 668 /* 669 * Better tell the user the bad news... 670 * if this is a block aligned archive format, we may have a bad archive 671 * if the format wants the header to start at a BLKMULT boundary. While 672 * we can deal with the mis-aligned data, it violates spec and other 673 * archive readers will likely fail. if the format is not block 674 * aligned, the user may be lucky (and the archive is ok). 675 */ 676 if (res >= 0) { 677 if (res > 0) 678 wr_trail = 1; 679 io_ok = 1; 680 } 681 682 /* 683 * If we were trying to rewrite the trailer and it didn't work, we 684 * must quit right away. 685 */ 686 if (!wr_trail && (res <= 0)) { 687 paxwarn(1,"Unable to append, trailer re-write failed. Quitting."); 688 return(res); 689 } 690 691 if (res == 0) 692 paxwarn(0, "End of archive volume %d reached", arvol); 693 else if (res < 0) 694 syswarn(1, errno, "Failed write to archive volume: %d", arvol); 695 else if (!frmt->blkalgn || ((res % frmt->blkalgn) == 0)) 696 paxwarn(0,"WARNING: partial archive write. Archive MAY BE FLAWED"); 697 else 698 paxwarn(1,"WARNING: partial archive write. Archive IS FLAWED"); 699 return(res); 700 } 701 702 /* 703 * ar_rdsync() 704 * Try to move past a bad spot on a flawed archive as needed to continue 705 * I/O. Clears error flags to allow I/O to continue. 706 * Return: 707 * 0 when ok to try i/o again, -1 otherwise. 708 */ 709 710 int 711 ar_rdsync(void) 712 { 713 long fsbz; 714 off_t cpos; 715 off_t mpos; 716 struct mtop mb; 717 718 /* 719 * Fail resync attempts at user request (done) or this is going to be 720 * an update/append to a existing archive. if last i/o hit media end, 721 * we need to go to the next volume not try a resync 722 */ 723 if ((done > 0) || (lstrval == 0)) 724 return(-1); 725 726 if ((act == APPND) || (act == ARCHIVE)) { 727 paxwarn(1, "Cannot allow updates to an archive with flaws."); 728 return(-1); 729 } 730 if (io_ok) 731 did_io = 1; 732 733 switch(artyp) { 734 case ISTAPE: 735 /* 736 * if the last i/o was a successful data transfer, we assume 737 * the fault is just a bad record on the tape that we are now 738 * past. If we did not get any data since the last resync try 739 * to move the tape forward one PHYSICAL record past any 740 * damaged tape section. Some tape drives are stubborn and need 741 * to be pushed. 742 */ 743 if (io_ok) { 744 io_ok = 0; 745 lstrval = 1; 746 break; 747 } 748 mb.mt_op = MTFSR; 749 mb.mt_count = 1; 750 if (ioctl(arfd, MTIOCTOP, &mb) < 0) 751 break; 752 lstrval = 1; 753 break; 754 case ISREG: 755 case ISCHR: 756 case ISBLK: 757 /* 758 * try to step over the bad part of the device. 759 */ 760 io_ok = 0; 761 if (((fsbz = arsb.st_blksize) <= 0) || (artyp != ISREG)) 762 fsbz = BLKMULT; 763 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 764 break; 765 mpos = fsbz - (cpos % (off_t)fsbz); 766 if (lseek(arfd, mpos, SEEK_CUR) < 0) 767 break; 768 lstrval = 1; 769 break; 770 case ISPIPE: 771 default: 772 /* 773 * cannot recover on these archive device types 774 */ 775 io_ok = 0; 776 break; 777 } 778 if (lstrval <= 0) { 779 paxwarn(1, "Unable to recover from an archive read failure."); 780 return(-1); 781 } 782 paxwarn(0, "Attempting to recover from an archive read failure."); 783 return(0); 784 } 785 786 /* 787 * ar_fow() 788 * Move the I/O position within the archive foward the specified number of 789 * bytes as supported by the device. If we cannot move the requested 790 * number of bytes, return the actual number of bytes moved in skipped. 791 * Return: 792 * 0 if moved the requested distance, -1 on complete failure, 1 on 793 * partial move (the amount moved is in skipped) 794 */ 795 796 int 797 ar_fow(off_t sksz, off_t *skipped) 798 { 799 off_t cpos; 800 off_t mpos; 801 802 *skipped = 0; 803 if (sksz <= 0) 804 return(0); 805 806 /* 807 * we cannot move foward at EOF or error 808 */ 809 if (lstrval <= 0) 810 return(lstrval); 811 812 /* 813 * Safer to read forward on devices where it is hard to find the end of 814 * the media without reading to it. With tapes we cannot be sure of the 815 * number of physical blocks to skip (we do not know physical block 816 * size at this point), so we must only read foward on tapes! 817 */ 818 if (artyp != ISREG) 819 return(0); 820 821 /* 822 * figure out where we are in the archive 823 */ 824 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) >= 0) { 825 /* 826 * we can be asked to move farther than there are bytes in this 827 * volume, if so, just go to file end and let normal buf_fill() 828 * deal with the end of file (it will go to next volume by 829 * itself) 830 */ 831 if ((mpos = cpos + sksz) > arsb.st_size) { 832 *skipped = arsb.st_size - cpos; 833 mpos = arsb.st_size; 834 } else 835 *skipped = sksz; 836 if (lseek(arfd, mpos, SEEK_SET) >= 0) 837 return(0); 838 } 839 syswarn(1, errno, "Forward positioning operation on archive failed"); 840 lstrval = -1; 841 return(-1); 842 } 843 844 /* 845 * ar_rev() 846 * move the i/o position within the archive backwards the specified byte 847 * count as supported by the device. With tapes drives we RESET rdblksz to 848 * the PHYSICAL blocksize. 849 * NOTE: We should only be called to move backwards so we can rewrite the 850 * last records (the trailer) of an archive (APPEND). 851 * Return: 852 * 0 if moved the requested distance, -1 on complete failure 853 */ 854 855 int 856 ar_rev(off_t sksz) 857 { 858 off_t cpos; 859 struct mtop mb; 860 register int phyblk; 861 862 /* 863 * make sure we do not have try to reverse on a flawed archive 864 */ 865 if (lstrval < 0) 866 return(lstrval); 867 868 switch(artyp) { 869 case ISPIPE: 870 if (sksz <= 0) 871 break; 872 /* 873 * cannot go backwards on these critters 874 */ 875 paxwarn(1, "Reverse positioning on pipes is not supported."); 876 lstrval = -1; 877 return(-1); 878 case ISREG: 879 case ISBLK: 880 case ISCHR: 881 default: 882 if (sksz <= 0) 883 break; 884 885 /* 886 * For things other than files, backwards movement has a very 887 * high probability of failure as we really do not know the 888 * true attributes of the device we are talking to (the device 889 * may not even have the ability to lseek() in any direction). 890 * First we figure out where we are in the archive. 891 */ 892 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) { 893 syswarn(1, errno, 894 "Unable to obtain current archive byte offset"); 895 lstrval = -1; 896 return(-1); 897 } 898 899 /* 900 * we may try to go backwards past the start when the archive 901 * is only a single record. If this hapens and we are on a 902 * multi volume archive, we need to go to the end of the 903 * previous volume and continue our movement backwards from 904 * there. 905 */ 906 if ((cpos -= sksz) < (off_t)0L) { 907 if (arvol > 1) { 908 /* 909 * this should never happen 910 */ 911 paxwarn(1,"Reverse position on previous volume."); 912 lstrval = -1; 913 return(-1); 914 } 915 cpos = (off_t)0L; 916 } 917 if (lseek(arfd, cpos, SEEK_SET) < 0) { 918 syswarn(1, errno, "Unable to seek archive backwards"); 919 lstrval = -1; 920 return(-1); 921 } 922 break; 923 case ISTAPE: 924 /* 925 * Calculate and move the proper number of PHYSICAL tape 926 * blocks. If the sksz is not an even multiple of the physical 927 * tape size, we cannot do the move (this should never happen). 928 * (We also cannot handler trailers spread over two vols). 929 * get_phys() also makes sure we are in front of the filemark. 930 */ 931 if ((phyblk = get_phys()) <= 0) { 932 lstrval = -1; 933 return(-1); 934 } 935 936 /* 937 * make sure future tape reads only go by physical tape block 938 * size (set rdblksz to the real size). 939 */ 940 rdblksz = phyblk; 941 942 /* 943 * if no movement is required, just return (we must be after 944 * get_phys() so the physical blocksize is properly set) 945 */ 946 if (sksz <= 0) 947 break; 948 949 /* 950 * ok we have to move. Make sure the tape drive can do it. 951 */ 952 if (sksz % phyblk) { 953 paxwarn(1, 954 "Tape drive unable to backspace requested amount"); 955 lstrval = -1; 956 return(-1); 957 } 958 959 /* 960 * move backwards the requested number of bytes 961 */ 962 mb.mt_op = MTBSR; 963 mb.mt_count = sksz/phyblk; 964 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 965 syswarn(1,errno, "Unable to backspace tape %d blocks.", 966 mb.mt_count); 967 lstrval = -1; 968 return(-1); 969 } 970 break; 971 } 972 lstrval = 1; 973 return(0); 974 } 975 976 /* 977 * get_phys() 978 * Determine the physical block size on a tape drive. We need the physical 979 * block size so we know how many bytes we skip over when we move with 980 * mtio commands. We also make sure we are BEFORE THE TAPE FILEMARK when 981 * return. 982 * This is one really SLOW routine... 983 * Return: 984 * physical block size if ok (ok > 0), -1 otherwise 985 */ 986 987 static int 988 get_phys(void) 989 { 990 register int padsz = 0; 991 register int res; 992 register int phyblk; 993 struct mtop mb; 994 char scbuf[MAXBLK]; 995 996 /* 997 * move to the file mark, and then back up one record and read it. 998 * this should tell us the physical record size the tape is using. 999 */ 1000 if (lstrval == 1) { 1001 /* 1002 * we know we are at file mark when we get back a 0 from 1003 * read() 1004 */ 1005 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1006 padsz += res; 1007 if (res < 0) { 1008 syswarn(1, errno, "Unable to locate tape filemark."); 1009 return(-1); 1010 } 1011 } 1012 1013 /* 1014 * move backwards over the file mark so we are at the end of the 1015 * last record. 1016 */ 1017 mb.mt_op = MTBSF; 1018 mb.mt_count = 1; 1019 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1020 syswarn(1, errno, "Unable to backspace over tape filemark."); 1021 return(-1); 1022 } 1023 1024 /* 1025 * move backwards so we are in front of the last record and read it to 1026 * get physical tape blocksize. 1027 */ 1028 mb.mt_op = MTBSR; 1029 mb.mt_count = 1; 1030 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1031 syswarn(1, errno, "Unable to backspace over last tape block."); 1032 return(-1); 1033 } 1034 if ((phyblk = read(arfd, scbuf, sizeof(scbuf))) <= 0) { 1035 syswarn(1, errno, "Cannot determine archive tape blocksize."); 1036 return(-1); 1037 } 1038 1039 /* 1040 * read foward to the file mark, then back up in front of the filemark 1041 * (this is a bit paranoid, but should be safe to do). 1042 */ 1043 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1044 ; 1045 if (res < 0) { 1046 syswarn(1, errno, "Unable to locate tape filemark."); 1047 return(-1); 1048 } 1049 mb.mt_op = MTBSF; 1050 mb.mt_count = 1; 1051 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1052 syswarn(1, errno, "Unable to backspace over tape filemark."); 1053 return(-1); 1054 } 1055 1056 /* 1057 * set lstrval so we know that the filemark has not been seen 1058 */ 1059 lstrval = 1; 1060 1061 /* 1062 * return if there was no padding 1063 */ 1064 if (padsz == 0) 1065 return(phyblk); 1066 1067 /* 1068 * make sure we can move backwards over the padding. (this should 1069 * never fail). 1070 */ 1071 if (padsz % phyblk) { 1072 paxwarn(1, "Tape drive unable to backspace requested amount"); 1073 return(-1); 1074 } 1075 1076 /* 1077 * move backwards over the padding so the head is where it was when 1078 * we were first called (if required). 1079 */ 1080 mb.mt_op = MTBSR; 1081 mb.mt_count = padsz/phyblk; 1082 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1083 syswarn(1,errno,"Unable to backspace tape over %d pad blocks", 1084 mb.mt_count); 1085 return(-1); 1086 } 1087 return(phyblk); 1088 } 1089 1090 /* 1091 * ar_next() 1092 * prompts the user for the next volume in this archive. For some devices 1093 * we may allow the media to be changed. Otherwise a new archive is 1094 * prompted for. By pax spec, if there is no controlling tty or an eof is 1095 * read on tty input, we must quit pax. 1096 * Return: 1097 * 0 when ready to continue, -1 when all done 1098 */ 1099 1100 int 1101 ar_next(void) 1102 { 1103 char buf[PAXPATHLEN+2]; 1104 static int freeit = 0; 1105 sigset_t o_mask; 1106 1107 /* 1108 * WE MUST CLOSE THE DEVICE. A lot of devices must see last close, (so 1109 * things like writing EOF etc will be done) (Watch out ar_close() can 1110 * also be called via a signal handler, so we must prevent a race. 1111 */ 1112 if (sigprocmask(SIG_BLOCK, &s_mask, &o_mask) < 0) 1113 syswarn(0, errno, "Unable to set signal mask"); 1114 ar_close(); 1115 if (sigprocmask(SIG_SETMASK, &o_mask, NULL) < 0) 1116 syswarn(0, errno, "Unable to restore signal mask"); 1117 1118 if (done || !wr_trail || strcmp(NM_TAR, argv0) == 0) 1119 return(-1); 1120 1121 tty_prnt("\nATTENTION! %s archive volume change required.\n", argv0); 1122 1123 /* 1124 * if i/o is on stdin or stdout, we cannot reopen it (we do not know 1125 * the name), the user will be forced to type it in. 1126 */ 1127 if (strcmp(arcname, STDO) && strcmp(arcname, STDN) && (artyp != ISREG) 1128 && (artyp != ISPIPE)) { 1129 if (artyp == ISTAPE) { 1130 tty_prnt("%s ready for archive tape volume: %d\n", 1131 arcname, arvol); 1132 tty_prnt("Load the NEXT TAPE on the tape drive"); 1133 } else { 1134 tty_prnt("%s ready for archive volume: %d\n", 1135 arcname, arvol); 1136 tty_prnt("Load the NEXT STORAGE MEDIA (if required)"); 1137 } 1138 1139 if ((act == ARCHIVE) || (act == APPND)) 1140 tty_prnt(" and make sure it is WRITE ENABLED.\n"); 1141 else 1142 tty_prnt("\n"); 1143 1144 for(;;) { 1145 tty_prnt("Type \"y\" to continue, \".\" to quit %s,", 1146 argv0); 1147 tty_prnt(" or \"s\" to switch to new device.\nIf you"); 1148 tty_prnt(" cannot change storage media, type \"s\"\n"); 1149 tty_prnt("Is the device ready and online? > "); 1150 1151 if ((tty_read(buf,sizeof(buf))<0) || !strcmp(buf,".")){ 1152 done = 1; 1153 lstrval = -1; 1154 tty_prnt("Quitting %s!\n", argv0); 1155 vfpart = 0; 1156 return(-1); 1157 } 1158 1159 if ((buf[0] == '\0') || (buf[1] != '\0')) { 1160 tty_prnt("%s unknown command, try again\n",buf); 1161 continue; 1162 } 1163 1164 switch (buf[0]) { 1165 case 'y': 1166 case 'Y': 1167 /* 1168 * we are to continue with the same device 1169 */ 1170 if (ar_open(arcname) >= 0) 1171 return(0); 1172 tty_prnt("Cannot re-open %s, try again\n", 1173 arcname); 1174 continue; 1175 case 's': 1176 case 'S': 1177 /* 1178 * user wants to open a different device 1179 */ 1180 tty_prnt("Switching to a different archive\n"); 1181 break; 1182 default: 1183 tty_prnt("%s unknown command, try again\n",buf); 1184 continue; 1185 } 1186 break; 1187 } 1188 } else 1189 tty_prnt("Ready for archive volume: %d\n", arvol); 1190 1191 /* 1192 * have to go to a different archive 1193 */ 1194 for (;;) { 1195 tty_prnt("Input archive name or \".\" to quit %s.\n", argv0); 1196 tty_prnt("Archive name > "); 1197 1198 if ((tty_read(buf, sizeof(buf)) < 0) || !strcmp(buf, ".")) { 1199 done = 1; 1200 lstrval = -1; 1201 tty_prnt("Quitting %s!\n", argv0); 1202 vfpart = 0; 1203 return(-1); 1204 } 1205 if (buf[0] == '\0') { 1206 tty_prnt("Empty file name, try again\n"); 1207 continue; 1208 } 1209 if (!strcmp(buf, "..")) { 1210 tty_prnt("Illegal file name: .. try again\n"); 1211 continue; 1212 } 1213 if (strlen(buf) > PAXPATHLEN) { 1214 tty_prnt("File name too long, try again\n"); 1215 continue; 1216 } 1217 1218 /* 1219 * try to open new archive 1220 */ 1221 if (ar_open(buf) >= 0) { 1222 if (freeit) { 1223 (void)free(arcname); 1224 freeit = 0; 1225 } 1226 if ((arcname = strdup(buf)) == NULL) { 1227 done = 1; 1228 lstrval = -1; 1229 paxwarn(0, "Cannot save archive name."); 1230 return(-1); 1231 } 1232 freeit = 1; 1233 break; 1234 } 1235 tty_prnt("Cannot open %s, try again\n", buf); 1236 continue; 1237 } 1238 return(0); 1239 } 1240 1241 /* 1242 * ar_start_gzip() 1243 * starts the gzip compression/decompression process as a child, using magic 1244 * to keep the fd the same in the calling function (parent). 1245 */ 1246 void 1247 ar_start_gzip(int fd, const char *gzip_program, int wr) 1248 { 1249 int fds[2]; 1250 char *gzip_flags; 1251 1252 if (pipe(fds) < 0) 1253 err(1, "could not pipe"); 1254 zpid = fork(); 1255 if (zpid < 0) 1256 err(1, "could not fork"); 1257 1258 /* parent */ 1259 if (zpid) { 1260 if (wr) 1261 dup2(fds[1], fd); 1262 else 1263 dup2(fds[0], fd); 1264 close(fds[0]); 1265 close(fds[1]); 1266 } else { 1267 if (wr) { 1268 dup2(fds[0], STDIN_FILENO); 1269 dup2(fd, STDOUT_FILENO); 1270 gzip_flags = "-c"; 1271 } else { 1272 dup2(fds[1], STDOUT_FILENO); 1273 dup2(fd, STDIN_FILENO); 1274 gzip_flags = "-dc"; 1275 } 1276 close(fds[0]); 1277 close(fds[1]); 1278 if (execlp(gzip_program, gzip_program, gzip_flags, 1279 (char *)NULL) < 0) 1280 err(1, "could not exec"); 1281 /* NOTREACHED */ 1282 } 1283 } 1284