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 1.2 2003/06/17 04:22:50 dillon 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 __P((void)); 85 extern sigset_t s_mask; 86 static void ar_start_gzip __P((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 #ifdef __STDC__ 98 int 99 ar_open(char *name) 100 #else 101 int 102 ar_open(name) 103 char *name; 104 #endif 105 { 106 struct mtget mb; 107 108 if (arfd != -1) 109 (void)close(arfd); 110 arfd = -1; 111 can_unlnk = did_io = io_ok = invld_rec = 0; 112 artyp = ISREG; 113 flcnt = 0; 114 115 /* 116 * open based on overall operation mode 117 */ 118 switch (act) { 119 case LIST: 120 case EXTRACT: 121 if (name == NULL) { 122 arfd = STDIN_FILENO; 123 arcname = STDN; 124 } else if ((arfd = open(name, EXT_MODE, DMOD)) < 0) 125 syswarn(0, errno, "Failed open to read on %s", name); 126 if (arfd != -1 && gzip_program != NULL) 127 ar_start_gzip(arfd, gzip_program, 0); 128 break; 129 case ARCHIVE: 130 if (name == NULL) { 131 arfd = STDOUT_FILENO; 132 arcname = STDO; 133 } else if ((arfd = open(name, AR_MODE, DMOD)) < 0) 134 syswarn(0, errno, "Failed open to write on %s", name); 135 else 136 can_unlnk = 1; 137 if (arfd != -1 && gzip_program != NULL) 138 ar_start_gzip(arfd, gzip_program, 1); 139 break; 140 case APPND: 141 if (name == NULL) { 142 arfd = STDOUT_FILENO; 143 arcname = STDO; 144 } else if ((arfd = open(name, APP_MODE, DMOD)) < 0) 145 syswarn(0, errno, "Failed open to read/write on %s", 146 name); 147 break; 148 case COPY: 149 /* 150 * arfd not used in COPY mode 151 */ 152 arcname = "<NONE>"; 153 lstrval = 1; 154 return(0); 155 } 156 if (arfd < 0) 157 return(-1); 158 159 if (chdname != NULL) 160 if (chdir(chdname) != 0) 161 syswarn(1, errno, "Failed chdir to %s", chdname); 162 /* 163 * set up is based on device type 164 */ 165 if (fstat(arfd, &arsb) < 0) { 166 syswarn(0, errno, "Failed stat on %s", arcname); 167 (void)close(arfd); 168 arfd = -1; 169 can_unlnk = 0; 170 return(-1); 171 } 172 if (S_ISDIR(arsb.st_mode)) { 173 paxwarn(0, "Cannot write an archive on top of a directory %s", 174 arcname); 175 (void)close(arfd); 176 arfd = -1; 177 can_unlnk = 0; 178 return(-1); 179 } 180 181 if (S_ISCHR(arsb.st_mode)) 182 artyp = ioctl(arfd, MTIOCGET, &mb) ? ISCHR : ISTAPE; 183 else if (S_ISBLK(arsb.st_mode)) 184 artyp = ISBLK; 185 else if ((lseek(arfd, (off_t)0L, SEEK_CUR) == -1) && (errno == ESPIPE)) 186 artyp = ISPIPE; 187 else 188 artyp = ISREG; 189 190 /* 191 * make sure we beyond any doubt that we only can unlink regular files 192 * we created 193 */ 194 if (artyp != ISREG) 195 can_unlnk = 0; 196 /* 197 * if we are writing, we are done 198 */ 199 if (act == ARCHIVE) { 200 blksz = rdblksz = wrblksz; 201 lstrval = 1; 202 return(0); 203 } 204 205 /* 206 * set default blksz on read. APPNDs writes rdblksz on the last volume 207 * On all new archive volumes, we shift to wrblksz (if the user 208 * specified one, otherwize we will continue to use rdblksz). We 209 * must to set blocksize based on what kind of device the archive is 210 * stored. 211 */ 212 switch(artyp) { 213 case ISTAPE: 214 /* 215 * Tape drives come in at least two flavors. Those that support 216 * variable sized records and those that have fixed sized 217 * records. They must be treated differently. For tape drives 218 * that support variable sized records, we must make large 219 * reads to make sure we get the entire record, otherwise we 220 * will just get the first part of the record (up to size we 221 * asked). Tapes with fixed sized records may or may not return 222 * multiple records in a single read. We really do not care 223 * what the physical record size is UNLESS we are going to 224 * append. (We will need the physical block size to rewrite 225 * the trailer). Only when we are appending do we go to the 226 * effort to figure out the true PHYSICAL record size. 227 */ 228 blksz = rdblksz = MAXBLK; 229 break; 230 case ISPIPE: 231 case ISBLK: 232 case ISCHR: 233 /* 234 * Blocksize is not a major issue with these devices (but must 235 * be kept a multiple of 512). If the user specified a write 236 * block size, we use that to read. Under append, we must 237 * always keep blksz == rdblksz. Otherwise we go ahead and use 238 * the device optimal blocksize as (and if) returned by stat 239 * and if it is within pax specs. 240 */ 241 if ((act == APPND) && wrblksz) { 242 blksz = rdblksz = wrblksz; 243 break; 244 } 245 246 if ((arsb.st_blksize > 0) && (arsb.st_blksize < MAXBLK) && 247 ((arsb.st_blksize % BLKMULT) == 0)) 248 rdblksz = arsb.st_blksize; 249 else 250 rdblksz = DEVBLK; 251 /* 252 * For performance go for large reads when we can without harm 253 */ 254 if ((act == APPND) || (artyp == ISCHR)) 255 blksz = rdblksz; 256 else 257 blksz = MAXBLK; 258 break; 259 case ISREG: 260 /* 261 * if the user specified wrblksz works, use it. Under appends 262 * we must always keep blksz == rdblksz 263 */ 264 if ((act == APPND) && wrblksz && ((arsb.st_size%wrblksz)==0)){ 265 blksz = rdblksz = wrblksz; 266 break; 267 } 268 /* 269 * See if we can find the blocking factor from the file size 270 */ 271 for (rdblksz = MAXBLK; rdblksz > 0; rdblksz -= BLKMULT) 272 if ((arsb.st_size % rdblksz) == 0) 273 break; 274 /* 275 * When we cannot find a match, we may have a flawed archive. 276 */ 277 if (rdblksz <= 0) 278 rdblksz = FILEBLK; 279 /* 280 * for performance go for large reads when we can 281 */ 282 if (act == APPND) 283 blksz = rdblksz; 284 else 285 blksz = MAXBLK; 286 break; 287 default: 288 /* 289 * should never happen, worse case, slow... 290 */ 291 blksz = rdblksz = BLKMULT; 292 break; 293 } 294 lstrval = 1; 295 return(0); 296 } 297 298 /* 299 * ar_close() 300 * closes archive device, increments volume number, and prints i/o summary 301 */ 302 #ifdef __STDC__ 303 void 304 ar_close(void) 305 #else 306 void 307 ar_close() 308 #endif 309 { 310 311 if (arfd < 0) { 312 did_io = io_ok = flcnt = 0; 313 return; 314 } 315 316 /* 317 * Close archive file. This may take a LONG while on tapes (we may be 318 * forced to wait for the rewind to complete) so tell the user what is 319 * going on (this avoids the user hitting control-c thinking pax is 320 * broken). 321 */ 322 if (vflag && (artyp == ISTAPE)) { 323 if (vfpart) 324 (void)putc('\n', listf); 325 (void)fprintf(listf, 326 "%s: Waiting for tape drive close to complete...", 327 argv0); 328 (void)fflush(listf); 329 } 330 331 /* 332 * if nothing was written to the archive (and we created it), we remove 333 * it 334 */ 335 if (can_unlnk && (fstat(arfd, &arsb) == 0) && (S_ISREG(arsb.st_mode)) && 336 (arsb.st_size == 0)) { 337 (void)unlink(arcname); 338 can_unlnk = 0; 339 } 340 341 /* 342 * for a quick extract/list, pax frequently exits before the child 343 * process is done 344 */ 345 if ((act == LIST || act == EXTRACT) && nflag && zpid > 0) { 346 int status; 347 kill(zpid, SIGINT); 348 waitpid(zpid, &status, 0); 349 } 350 351 (void)close(arfd); 352 353 if (vflag && (artyp == ISTAPE)) { 354 (void)fputs("done.\n", listf); 355 vfpart = 0; 356 (void)fflush(listf); 357 } 358 arfd = -1; 359 360 if (!io_ok && !did_io) { 361 flcnt = 0; 362 return; 363 } 364 did_io = io_ok = 0; 365 366 /* 367 * The volume number is only increased when the last device has data 368 * and we have already determined the archive format. 369 */ 370 if (frmt != NULL) 371 ++arvol; 372 373 if (!vflag) { 374 flcnt = 0; 375 return; 376 } 377 378 /* 379 * Print out a summary of I/O for this archive volume. 380 */ 381 if (vfpart) { 382 (void)putc('\n', listf); 383 vfpart = 0; 384 } 385 386 /* 387 * If we have not determined the format yet, we just say how many bytes 388 * we have skipped over looking for a header to id. there is no way we 389 * could have written anything yet. 390 */ 391 if (frmt == NULL) { 392 # ifdef NET2_STAT 393 (void)fprintf(listf, "%s: unknown format, %lu bytes skipped.\n", 394 # else 395 (void)fprintf(listf, "%s: unknown format, %qu bytes skipped.\n", 396 # endif 397 argv0, rdcnt); 398 (void)fflush(listf); 399 flcnt = 0; 400 return; 401 } 402 403 if (strcmp(NM_CPIO, argv0) == 0) 404 (void)fprintf(listf, "%qu blocks\n", (rdcnt ? rdcnt : wrcnt) / 5120); 405 else if (strcmp(NM_TAR, argv0) != 0) 406 (void)fprintf(listf, 407 # ifdef NET2_STAT 408 "%s: %s vol %d, %lu files, %lu bytes read, %lu bytes written.\n", 409 # else 410 "%s: %s vol %d, %lu files, %qu bytes read, %qu bytes written.\n", 411 # endif 412 argv0, frmt->name, arvol-1, flcnt, rdcnt, wrcnt); 413 (void)fflush(listf); 414 flcnt = 0; 415 } 416 417 /* 418 * ar_drain() 419 * drain any archive format independent padding from an archive read 420 * from a socket or a pipe. This is to prevent the process on the 421 * other side of the pipe from getting a SIGPIPE (pax will stop 422 * reading an archive once a format dependent trailer is detected). 423 */ 424 #ifdef __STDC__ 425 void 426 ar_drain(void) 427 #else 428 void 429 ar_drain() 430 #endif 431 { 432 register int res; 433 char drbuf[MAXBLK]; 434 435 /* 436 * we only drain from a pipe/socket. Other devices can be closed 437 * without reading up to end of file. We sure hope that pipe is closed 438 * on the other side so we will get an EOF. 439 */ 440 if ((artyp != ISPIPE) || (lstrval <= 0)) 441 return; 442 443 /* 444 * keep reading until pipe is drained 445 */ 446 while ((res = read(arfd, drbuf, sizeof(drbuf))) > 0) 447 ; 448 lstrval = res; 449 } 450 451 /* 452 * ar_set_wr() 453 * Set up device right before switching from read to write in an append. 454 * device dependent code (if required) to do this should be added here. 455 * For all archive devices we are already positioned at the place we want 456 * to start writing when this routine is called. 457 * Return: 458 * 0 if all ready to write, -1 otherwise 459 */ 460 461 #ifdef __STDC__ 462 int 463 ar_set_wr(void) 464 #else 465 int 466 ar_set_wr() 467 #endif 468 { 469 off_t cpos; 470 471 /* 472 * we must make sure the trailer is rewritten on append, ar_next() 473 * will stop us if the archive containing the trailer was not written 474 */ 475 wr_trail = 0; 476 477 /* 478 * Add any device dependent code as required here 479 */ 480 if (artyp != ISREG) 481 return(0); 482 /* 483 * Ok we have an archive in a regular file. If we were rewriting a 484 * file, we must get rid of all the stuff after the current offset 485 * (it was not written by pax). 486 */ 487 if (((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) || 488 (ftruncate(arfd, cpos) < 0)) { 489 syswarn(1, errno, "Unable to truncate archive file"); 490 return(-1); 491 } 492 return(0); 493 } 494 495 /* 496 * ar_app_ok() 497 * check if the last volume in the archive allows appends. We cannot check 498 * this until we are ready to write since there is no spec that says all 499 * volumes in a single archive have to be of the same type... 500 * Return: 501 * 0 if we can append, -1 otherwise. 502 */ 503 504 #ifdef __STDC__ 505 int 506 ar_app_ok(void) 507 #else 508 int 509 ar_app_ok() 510 #endif 511 { 512 if (artyp == ISPIPE) { 513 paxwarn(1, "Cannot append to an archive obtained from a pipe."); 514 return(-1); 515 } 516 517 if (!invld_rec) 518 return(0); 519 paxwarn(1,"Cannot append, device record size %d does not support %s spec", 520 rdblksz, argv0); 521 return(-1); 522 } 523 524 /* 525 * ar_read() 526 * read up to a specified number of bytes from the archive into the 527 * supplied buffer. When dealing with tapes we may not always be able to 528 * read what we want. 529 * Return: 530 * Number of bytes in buffer. 0 for end of file, -1 for a read error. 531 */ 532 533 #ifdef __STDC__ 534 int 535 ar_read(register char *buf, register int cnt) 536 #else 537 int 538 ar_read(buf, cnt) 539 register char *buf; 540 register int cnt; 541 #endif 542 { 543 register int res = 0; 544 545 /* 546 * if last i/o was in error, no more reads until reset or new volume 547 */ 548 if (lstrval <= 0) 549 return(lstrval); 550 551 /* 552 * how we read must be based on device type 553 */ 554 switch (artyp) { 555 case ISTAPE: 556 if ((res = read(arfd, buf, cnt)) > 0) { 557 /* 558 * CAUTION: tape systems may not always return the same 559 * sized records so we leave blksz == MAXBLK. The 560 * physical record size that a tape drive supports is 561 * very hard to determine in a uniform and portable 562 * manner. 563 */ 564 io_ok = 1; 565 if (res != rdblksz) { 566 /* 567 * Record size changed. If this is happens on 568 * any record after the first, we probably have 569 * a tape drive which has a fixed record size 570 * we are getting multiple records in a single 571 * read). Watch out for record blocking that 572 * violates pax spec (must be a multiple of 573 * BLKMULT). 574 */ 575 rdblksz = res; 576 if (rdblksz % BLKMULT) 577 invld_rec = 1; 578 } 579 return(res); 580 } 581 break; 582 case ISREG: 583 case ISBLK: 584 case ISCHR: 585 case ISPIPE: 586 default: 587 /* 588 * Files are so easy to deal with. These other things cannot 589 * be trusted at all. So when we are dealing with character 590 * devices and pipes we just take what they have ready for us 591 * and return. Trying to do anything else with them runs the 592 * risk of failure. 593 */ 594 if ((res = read(arfd, buf, cnt)) > 0) { 595 io_ok = 1; 596 return(res); 597 } 598 break; 599 } 600 601 /* 602 * We are in trouble at this point, something is broken... 603 */ 604 lstrval = res; 605 if (res < 0) 606 syswarn(1, errno, "Failed read on archive volume %d", arvol); 607 else 608 paxwarn(0, "End of archive volume %d reached", arvol); 609 return(res); 610 } 611 612 /* 613 * ar_write() 614 * Write a specified number of bytes in supplied buffer to the archive 615 * device so it appears as a single "block". Deals with errors and tries 616 * to recover when faced with short writes. 617 * Return: 618 * Number of bytes written. 0 indicates end of volume reached and with no 619 * flaws (as best that can be detected). A -1 indicates an unrecoverable 620 * error in the archive occured. 621 */ 622 623 #ifdef __STDC__ 624 int 625 ar_write(register char *buf, register int bsz) 626 #else 627 int 628 ar_write(buf, bsz) 629 register char *buf; 630 register int bsz; 631 #endif 632 { 633 register int res; 634 off_t cpos; 635 636 /* 637 * do not allow pax to create a "bad" archive. Once a write fails on 638 * an archive volume prevent further writes to it. 639 */ 640 if (lstrval <= 0) 641 return(lstrval); 642 643 if ((res = write(arfd, buf, bsz)) == bsz) { 644 wr_trail = 1; 645 io_ok = 1; 646 return(bsz); 647 } 648 /* 649 * write broke, see what we can do with it. We try to send any partial 650 * writes that may violate pax spec to the next archive volume. 651 */ 652 if (res < 0) 653 lstrval = res; 654 else 655 lstrval = 0; 656 657 switch (artyp) { 658 case ISREG: 659 if ((res > 0) && (res % BLKMULT)) { 660 /* 661 * try to fix up partial writes which are not BLKMULT 662 * in size by forcing the runt record to next archive 663 * volume 664 */ 665 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 666 break; 667 cpos -= (off_t)res; 668 if (ftruncate(arfd, cpos) < 0) 669 break; 670 res = lstrval = 0; 671 break; 672 } 673 if (res >= 0) 674 break; 675 /* 676 * if file is out of space, handle it like a return of 0 677 */ 678 if ((errno == ENOSPC) || (errno == EFBIG) || (errno == EDQUOT)) 679 res = lstrval = 0; 680 break; 681 case ISTAPE: 682 case ISCHR: 683 case ISBLK: 684 if (res >= 0) 685 break; 686 if (errno == EACCES) { 687 paxwarn(0, "Write failed, archive is write protected."); 688 res = lstrval = 0; 689 return(0); 690 } 691 /* 692 * see if we reached the end of media, if so force a change to 693 * the next volume 694 */ 695 if ((errno == ENOSPC) || (errno == EIO) || (errno == ENXIO)) 696 res = lstrval = 0; 697 break; 698 case ISPIPE: 699 default: 700 /* 701 * we cannot fix errors to these devices 702 */ 703 break; 704 } 705 706 /* 707 * Better tell the user the bad news... 708 * if this is a block aligned archive format, we may have a bad archive 709 * if the format wants the header to start at a BLKMULT boundary. While 710 * we can deal with the mis-aligned data, it violates spec and other 711 * archive readers will likely fail. if the format is not block 712 * aligned, the user may be lucky (and the archive is ok). 713 */ 714 if (res >= 0) { 715 if (res > 0) 716 wr_trail = 1; 717 io_ok = 1; 718 } 719 720 /* 721 * If we were trying to rewrite the trailer and it didn't work, we 722 * must quit right away. 723 */ 724 if (!wr_trail && (res <= 0)) { 725 paxwarn(1,"Unable to append, trailer re-write failed. Quitting."); 726 return(res); 727 } 728 729 if (res == 0) 730 paxwarn(0, "End of archive volume %d reached", arvol); 731 else if (res < 0) 732 syswarn(1, errno, "Failed write to archive volume: %d", arvol); 733 else if (!frmt->blkalgn || ((res % frmt->blkalgn) == 0)) 734 paxwarn(0,"WARNING: partial archive write. Archive MAY BE FLAWED"); 735 else 736 paxwarn(1,"WARNING: partial archive write. Archive IS FLAWED"); 737 return(res); 738 } 739 740 /* 741 * ar_rdsync() 742 * Try to move past a bad spot on a flawed archive as needed to continue 743 * I/O. Clears error flags to allow I/O to continue. 744 * Return: 745 * 0 when ok to try i/o again, -1 otherwise. 746 */ 747 748 #ifdef __STDC__ 749 int 750 ar_rdsync(void) 751 #else 752 int 753 ar_rdsync() 754 #endif 755 { 756 long fsbz; 757 off_t cpos; 758 off_t mpos; 759 struct mtop mb; 760 761 /* 762 * Fail resync attempts at user request (done) or this is going to be 763 * an update/append to a existing archive. if last i/o hit media end, 764 * we need to go to the next volume not try a resync 765 */ 766 if ((done > 0) || (lstrval == 0)) 767 return(-1); 768 769 if ((act == APPND) || (act == ARCHIVE)) { 770 paxwarn(1, "Cannot allow updates to an archive with flaws."); 771 return(-1); 772 } 773 if (io_ok) 774 did_io = 1; 775 776 switch(artyp) { 777 case ISTAPE: 778 /* 779 * if the last i/o was a successful data transfer, we assume 780 * the fault is just a bad record on the tape that we are now 781 * past. If we did not get any data since the last resync try 782 * to move the tape forward one PHYSICAL record past any 783 * damaged tape section. Some tape drives are stubborn and need 784 * to be pushed. 785 */ 786 if (io_ok) { 787 io_ok = 0; 788 lstrval = 1; 789 break; 790 } 791 mb.mt_op = MTFSR; 792 mb.mt_count = 1; 793 if (ioctl(arfd, MTIOCTOP, &mb) < 0) 794 break; 795 lstrval = 1; 796 break; 797 case ISREG: 798 case ISCHR: 799 case ISBLK: 800 /* 801 * try to step over the bad part of the device. 802 */ 803 io_ok = 0; 804 if (((fsbz = arsb.st_blksize) <= 0) || (artyp != ISREG)) 805 fsbz = BLKMULT; 806 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) 807 break; 808 mpos = fsbz - (cpos % (off_t)fsbz); 809 if (lseek(arfd, mpos, SEEK_CUR) < 0) 810 break; 811 lstrval = 1; 812 break; 813 case ISPIPE: 814 default: 815 /* 816 * cannot recover on these archive device types 817 */ 818 io_ok = 0; 819 break; 820 } 821 if (lstrval <= 0) { 822 paxwarn(1, "Unable to recover from an archive read failure."); 823 return(-1); 824 } 825 paxwarn(0, "Attempting to recover from an archive read failure."); 826 return(0); 827 } 828 829 /* 830 * ar_fow() 831 * Move the I/O position within the archive foward the specified number of 832 * bytes as supported by the device. If we cannot move the requested 833 * number of bytes, return the actual number of bytes moved in skipped. 834 * Return: 835 * 0 if moved the requested distance, -1 on complete failure, 1 on 836 * partial move (the amount moved is in skipped) 837 */ 838 839 #ifdef __STDC__ 840 int 841 ar_fow(off_t sksz, off_t *skipped) 842 #else 843 int 844 ar_fow(sksz, skipped) 845 off_t sksz; 846 off_t *skipped; 847 #endif 848 { 849 off_t cpos; 850 off_t mpos; 851 852 *skipped = 0; 853 if (sksz <= 0) 854 return(0); 855 856 /* 857 * we cannot move foward at EOF or error 858 */ 859 if (lstrval <= 0) 860 return(lstrval); 861 862 /* 863 * Safer to read forward on devices where it is hard to find the end of 864 * the media without reading to it. With tapes we cannot be sure of the 865 * number of physical blocks to skip (we do not know physical block 866 * size at this point), so we must only read foward on tapes! 867 */ 868 if (artyp != ISREG) 869 return(0); 870 871 /* 872 * figure out where we are in the archive 873 */ 874 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) >= 0) { 875 /* 876 * we can be asked to move farther than there are bytes in this 877 * volume, if so, just go to file end and let normal buf_fill() 878 * deal with the end of file (it will go to next volume by 879 * itself) 880 */ 881 if ((mpos = cpos + sksz) > arsb.st_size) { 882 *skipped = arsb.st_size - cpos; 883 mpos = arsb.st_size; 884 } else 885 *skipped = sksz; 886 if (lseek(arfd, mpos, SEEK_SET) >= 0) 887 return(0); 888 } 889 syswarn(1, errno, "Forward positioning operation on archive failed"); 890 lstrval = -1; 891 return(-1); 892 } 893 894 /* 895 * ar_rev() 896 * move the i/o position within the archive backwards the specified byte 897 * count as supported by the device. With tapes drives we RESET rdblksz to 898 * the PHYSICAL blocksize. 899 * NOTE: We should only be called to move backwards so we can rewrite the 900 * last records (the trailer) of an archive (APPEND). 901 * Return: 902 * 0 if moved the requested distance, -1 on complete failure 903 */ 904 905 #ifdef __STDC__ 906 int 907 ar_rev(off_t sksz) 908 #else 909 int 910 ar_rev(sksz) 911 off_t sksz; 912 #endif 913 { 914 off_t cpos; 915 struct mtop mb; 916 register int phyblk; 917 918 /* 919 * make sure we do not have try to reverse on a flawed archive 920 */ 921 if (lstrval < 0) 922 return(lstrval); 923 924 switch(artyp) { 925 case ISPIPE: 926 if (sksz <= 0) 927 break; 928 /* 929 * cannot go backwards on these critters 930 */ 931 paxwarn(1, "Reverse positioning on pipes is not supported."); 932 lstrval = -1; 933 return(-1); 934 case ISREG: 935 case ISBLK: 936 case ISCHR: 937 default: 938 if (sksz <= 0) 939 break; 940 941 /* 942 * For things other than files, backwards movement has a very 943 * high probability of failure as we really do not know the 944 * true attributes of the device we are talking to (the device 945 * may not even have the ability to lseek() in any direction). 946 * First we figure out where we are in the archive. 947 */ 948 if ((cpos = lseek(arfd, (off_t)0L, SEEK_CUR)) < 0) { 949 syswarn(1, errno, 950 "Unable to obtain current archive byte offset"); 951 lstrval = -1; 952 return(-1); 953 } 954 955 /* 956 * we may try to go backwards past the start when the archive 957 * is only a single record. If this hapens and we are on a 958 * multi volume archive, we need to go to the end of the 959 * previous volume and continue our movement backwards from 960 * there. 961 */ 962 if ((cpos -= sksz) < (off_t)0L) { 963 if (arvol > 1) { 964 /* 965 * this should never happen 966 */ 967 paxwarn(1,"Reverse position on previous volume."); 968 lstrval = -1; 969 return(-1); 970 } 971 cpos = (off_t)0L; 972 } 973 if (lseek(arfd, cpos, SEEK_SET) < 0) { 974 syswarn(1, errno, "Unable to seek archive backwards"); 975 lstrval = -1; 976 return(-1); 977 } 978 break; 979 case ISTAPE: 980 /* 981 * Calculate and move the proper number of PHYSICAL tape 982 * blocks. If the sksz is not an even multiple of the physical 983 * tape size, we cannot do the move (this should never happen). 984 * (We also cannot handler trailers spread over two vols). 985 * get_phys() also makes sure we are in front of the filemark. 986 */ 987 if ((phyblk = get_phys()) <= 0) { 988 lstrval = -1; 989 return(-1); 990 } 991 992 /* 993 * make sure future tape reads only go by physical tape block 994 * size (set rdblksz to the real size). 995 */ 996 rdblksz = phyblk; 997 998 /* 999 * if no movement is required, just return (we must be after 1000 * get_phys() so the physical blocksize is properly set) 1001 */ 1002 if (sksz <= 0) 1003 break; 1004 1005 /* 1006 * ok we have to move. Make sure the tape drive can do it. 1007 */ 1008 if (sksz % phyblk) { 1009 paxwarn(1, 1010 "Tape drive unable to backspace requested amount"); 1011 lstrval = -1; 1012 return(-1); 1013 } 1014 1015 /* 1016 * move backwards the requested number of bytes 1017 */ 1018 mb.mt_op = MTBSR; 1019 mb.mt_count = sksz/phyblk; 1020 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1021 syswarn(1,errno, "Unable to backspace tape %d blocks.", 1022 mb.mt_count); 1023 lstrval = -1; 1024 return(-1); 1025 } 1026 break; 1027 } 1028 lstrval = 1; 1029 return(0); 1030 } 1031 1032 /* 1033 * get_phys() 1034 * Determine the physical block size on a tape drive. We need the physical 1035 * block size so we know how many bytes we skip over when we move with 1036 * mtio commands. We also make sure we are BEFORE THE TAPE FILEMARK when 1037 * return. 1038 * This is one really SLOW routine... 1039 * Return: 1040 * physical block size if ok (ok > 0), -1 otherwise 1041 */ 1042 1043 #ifdef __STDC__ 1044 static int 1045 get_phys(void) 1046 #else 1047 static int 1048 get_phys() 1049 #endif 1050 { 1051 register int padsz = 0; 1052 register int res; 1053 register int phyblk; 1054 struct mtop mb; 1055 char scbuf[MAXBLK]; 1056 1057 /* 1058 * move to the file mark, and then back up one record and read it. 1059 * this should tell us the physical record size the tape is using. 1060 */ 1061 if (lstrval == 1) { 1062 /* 1063 * we know we are at file mark when we get back a 0 from 1064 * read() 1065 */ 1066 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1067 padsz += res; 1068 if (res < 0) { 1069 syswarn(1, errno, "Unable to locate tape filemark."); 1070 return(-1); 1071 } 1072 } 1073 1074 /* 1075 * move backwards over the file mark so we are at the end of the 1076 * last record. 1077 */ 1078 mb.mt_op = MTBSF; 1079 mb.mt_count = 1; 1080 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1081 syswarn(1, errno, "Unable to backspace over tape filemark."); 1082 return(-1); 1083 } 1084 1085 /* 1086 * move backwards so we are in front of the last record and read it to 1087 * get physical tape blocksize. 1088 */ 1089 mb.mt_op = MTBSR; 1090 mb.mt_count = 1; 1091 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1092 syswarn(1, errno, "Unable to backspace over last tape block."); 1093 return(-1); 1094 } 1095 if ((phyblk = read(arfd, scbuf, sizeof(scbuf))) <= 0) { 1096 syswarn(1, errno, "Cannot determine archive tape blocksize."); 1097 return(-1); 1098 } 1099 1100 /* 1101 * read foward to the file mark, then back up in front of the filemark 1102 * (this is a bit paranoid, but should be safe to do). 1103 */ 1104 while ((res = read(arfd, scbuf, sizeof(scbuf))) > 0) 1105 ; 1106 if (res < 0) { 1107 syswarn(1, errno, "Unable to locate tape filemark."); 1108 return(-1); 1109 } 1110 mb.mt_op = MTBSF; 1111 mb.mt_count = 1; 1112 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1113 syswarn(1, errno, "Unable to backspace over tape filemark."); 1114 return(-1); 1115 } 1116 1117 /* 1118 * set lstrval so we know that the filemark has not been seen 1119 */ 1120 lstrval = 1; 1121 1122 /* 1123 * return if there was no padding 1124 */ 1125 if (padsz == 0) 1126 return(phyblk); 1127 1128 /* 1129 * make sure we can move backwards over the padding. (this should 1130 * never fail). 1131 */ 1132 if (padsz % phyblk) { 1133 paxwarn(1, "Tape drive unable to backspace requested amount"); 1134 return(-1); 1135 } 1136 1137 /* 1138 * move backwards over the padding so the head is where it was when 1139 * we were first called (if required). 1140 */ 1141 mb.mt_op = MTBSR; 1142 mb.mt_count = padsz/phyblk; 1143 if (ioctl(arfd, MTIOCTOP, &mb) < 0) { 1144 syswarn(1,errno,"Unable to backspace tape over %d pad blocks", 1145 mb.mt_count); 1146 return(-1); 1147 } 1148 return(phyblk); 1149 } 1150 1151 /* 1152 * ar_next() 1153 * prompts the user for the next volume in this archive. For some devices 1154 * we may allow the media to be changed. Otherwise a new archive is 1155 * prompted for. By pax spec, if there is no controlling tty or an eof is 1156 * read on tty input, we must quit pax. 1157 * Return: 1158 * 0 when ready to continue, -1 when all done 1159 */ 1160 1161 #ifdef __STDC__ 1162 int 1163 ar_next(void) 1164 #else 1165 int 1166 ar_next() 1167 #endif 1168 { 1169 char buf[PAXPATHLEN+2]; 1170 static int freeit = 0; 1171 sigset_t o_mask; 1172 1173 /* 1174 * WE MUST CLOSE THE DEVICE. A lot of devices must see last close, (so 1175 * things like writing EOF etc will be done) (Watch out ar_close() can 1176 * also be called via a signal handler, so we must prevent a race. 1177 */ 1178 if (sigprocmask(SIG_BLOCK, &s_mask, &o_mask) < 0) 1179 syswarn(0, errno, "Unable to set signal mask"); 1180 ar_close(); 1181 if (sigprocmask(SIG_SETMASK, &o_mask, NULL) < 0) 1182 syswarn(0, errno, "Unable to restore signal mask"); 1183 1184 if (done || !wr_trail || strcmp(NM_TAR, argv0) == 0) 1185 return(-1); 1186 1187 tty_prnt("\nATTENTION! %s archive volume change required.\n", argv0); 1188 1189 /* 1190 * if i/o is on stdin or stdout, we cannot reopen it (we do not know 1191 * the name), the user will be forced to type it in. 1192 */ 1193 if (strcmp(arcname, STDO) && strcmp(arcname, STDN) && (artyp != ISREG) 1194 && (artyp != ISPIPE)) { 1195 if (artyp == ISTAPE) { 1196 tty_prnt("%s ready for archive tape volume: %d\n", 1197 arcname, arvol); 1198 tty_prnt("Load the NEXT TAPE on the tape drive"); 1199 } else { 1200 tty_prnt("%s ready for archive volume: %d\n", 1201 arcname, arvol); 1202 tty_prnt("Load the NEXT STORAGE MEDIA (if required)"); 1203 } 1204 1205 if ((act == ARCHIVE) || (act == APPND)) 1206 tty_prnt(" and make sure it is WRITE ENABLED.\n"); 1207 else 1208 tty_prnt("\n"); 1209 1210 for(;;) { 1211 tty_prnt("Type \"y\" to continue, \".\" to quit %s,", 1212 argv0); 1213 tty_prnt(" or \"s\" to switch to new device.\nIf you"); 1214 tty_prnt(" cannot change storage media, type \"s\"\n"); 1215 tty_prnt("Is the device ready and online? > "); 1216 1217 if ((tty_read(buf,sizeof(buf))<0) || !strcmp(buf,".")){ 1218 done = 1; 1219 lstrval = -1; 1220 tty_prnt("Quitting %s!\n", argv0); 1221 vfpart = 0; 1222 return(-1); 1223 } 1224 1225 if ((buf[0] == '\0') || (buf[1] != '\0')) { 1226 tty_prnt("%s unknown command, try again\n",buf); 1227 continue; 1228 } 1229 1230 switch (buf[0]) { 1231 case 'y': 1232 case 'Y': 1233 /* 1234 * we are to continue with the same device 1235 */ 1236 if (ar_open(arcname) >= 0) 1237 return(0); 1238 tty_prnt("Cannot re-open %s, try again\n", 1239 arcname); 1240 continue; 1241 case 's': 1242 case 'S': 1243 /* 1244 * user wants to open a different device 1245 */ 1246 tty_prnt("Switching to a different archive\n"); 1247 break; 1248 default: 1249 tty_prnt("%s unknown command, try again\n",buf); 1250 continue; 1251 } 1252 break; 1253 } 1254 } else 1255 tty_prnt("Ready for archive volume: %d\n", arvol); 1256 1257 /* 1258 * have to go to a different archive 1259 */ 1260 for (;;) { 1261 tty_prnt("Input archive name or \".\" to quit %s.\n", argv0); 1262 tty_prnt("Archive name > "); 1263 1264 if ((tty_read(buf, sizeof(buf)) < 0) || !strcmp(buf, ".")) { 1265 done = 1; 1266 lstrval = -1; 1267 tty_prnt("Quitting %s!\n", argv0); 1268 vfpart = 0; 1269 return(-1); 1270 } 1271 if (buf[0] == '\0') { 1272 tty_prnt("Empty file name, try again\n"); 1273 continue; 1274 } 1275 if (!strcmp(buf, "..")) { 1276 tty_prnt("Illegal file name: .. try again\n"); 1277 continue; 1278 } 1279 if (strlen(buf) > PAXPATHLEN) { 1280 tty_prnt("File name too long, try again\n"); 1281 continue; 1282 } 1283 1284 /* 1285 * try to open new archive 1286 */ 1287 if (ar_open(buf) >= 0) { 1288 if (freeit) { 1289 (void)free(arcname); 1290 freeit = 0; 1291 } 1292 if ((arcname = strdup(buf)) == NULL) { 1293 done = 1; 1294 lstrval = -1; 1295 paxwarn(0, "Cannot save archive name."); 1296 return(-1); 1297 } 1298 freeit = 1; 1299 break; 1300 } 1301 tty_prnt("Cannot open %s, try again\n", buf); 1302 continue; 1303 } 1304 return(0); 1305 } 1306 1307 /* 1308 * ar_start_gzip() 1309 * starts the gzip compression/decompression process as a child, using magic 1310 * to keep the fd the same in the calling function (parent). 1311 */ 1312 void 1313 ar_start_gzip(int fd, const char *gzip_program, int wr) 1314 { 1315 int fds[2]; 1316 char *gzip_flags; 1317 1318 if (pipe(fds) < 0) 1319 err(1, "could not pipe"); 1320 zpid = fork(); 1321 if (zpid < 0) 1322 err(1, "could not fork"); 1323 1324 /* parent */ 1325 if (zpid) { 1326 if (wr) 1327 dup2(fds[1], fd); 1328 else 1329 dup2(fds[0], fd); 1330 close(fds[0]); 1331 close(fds[1]); 1332 } else { 1333 if (wr) { 1334 dup2(fds[0], STDIN_FILENO); 1335 dup2(fd, STDOUT_FILENO); 1336 gzip_flags = "-c"; 1337 } else { 1338 dup2(fds[1], STDOUT_FILENO); 1339 dup2(fd, STDIN_FILENO); 1340 gzip_flags = "-dc"; 1341 } 1342 close(fds[0]); 1343 close(fds[1]); 1344 if (execlp(gzip_program, gzip_program, gzip_flags, 1345 (char *)NULL) < 0) 1346 err(1, "could not exec"); 1347 /* NOTREACHED */ 1348 } 1349 } 1350