e2image.c revision e99decb0441cbf8fc1f33b254e510273a6095fd4
1/* 2 * e2image.c --- Program which writes an image file backing up 3 * critical metadata for the filesystem. 4 * 5 * Copyright 2000, 2001 by Theodore Ts'o. 6 * 7 * %Begin-Header% 8 * This file may be redistributed under the terms of the GNU Public 9 * License. 10 * %End-Header% 11 */ 12 13#define _LARGEFILE_SOURCE 14#define _LARGEFILE64_SOURCE 15 16#include <fcntl.h> 17#include <grp.h> 18#ifdef HAVE_GETOPT_H 19#include <getopt.h> 20#else 21extern char *optarg; 22extern int optind; 23#endif 24#include <pwd.h> 25#include <stdio.h> 26#include <stdlib.h> 27#include <string.h> 28#include <time.h> 29#include <unistd.h> 30#include <fcntl.h> 31#include <errno.h> 32#include <sys/stat.h> 33#include <sys/types.h> 34 35#include "ext2fs/ext2_fs.h" 36#include "ext2fs/ext2fs.h" 37#include "et/com_err.h" 38#include "uuid/uuid.h" 39#include "e2p/e2p.h" 40#include "ext2fs/e2image.h" 41 42#include "../version.h" 43#include "nls-enable.h" 44 45const char * program_name = "e2image"; 46char * device_name = NULL; 47 48static void usage(void) 49{ 50 fprintf(stderr, _("Usage: %s [-rsI] device image_file\n"), 51 program_name); 52 exit (1); 53} 54 55static void write_header(int fd, struct ext2_image_hdr *hdr, int blocksize) 56{ 57 char *header_buf; 58 int actual; 59 60 header_buf = malloc(blocksize); 61 if (!header_buf) { 62 fputs(_("Couldn't allocate header buffer\n"), stderr); 63 exit(1); 64 } 65 66 if (lseek(fd, 0, SEEK_SET) < 0) { 67 perror("lseek while writing header"); 68 exit(1); 69 } 70 memset(header_buf, 0, blocksize); 71 72 if (hdr) 73 memcpy(header_buf, hdr, sizeof(struct ext2_image_hdr)); 74 75 actual = write(fd, header_buf, blocksize); 76 if (actual < 0) { 77 perror("write header"); 78 exit(1); 79 } 80 if (actual != blocksize) { 81 fprintf(stderr, _("short write (only %d bytes) for " 82 "writing image header"), actual); 83 exit(1); 84 } 85 free(header_buf); 86} 87 88static void write_image_file(ext2_filsys fs, int fd) 89{ 90 struct ext2_image_hdr hdr; 91 struct stat st; 92 errcode_t retval; 93 94 write_header(fd, NULL, fs->blocksize); 95 memset(&hdr, 0, sizeof(struct ext2_image_hdr)); 96 97 hdr.offset_super = lseek(fd, 0, SEEK_CUR); 98 retval = ext2fs_image_super_write(fs, fd, 0); 99 if (retval) { 100 com_err(program_name, retval, _("while writing superblock")); 101 exit(1); 102 } 103 104 hdr.offset_inode = lseek(fd, 0, SEEK_CUR); 105 retval = ext2fs_image_inode_write(fs, fd, 106 (fd != 1) ? IMAGER_FLAG_SPARSEWRITE : 0); 107 if (retval) { 108 com_err(program_name, retval, _("while writing inode table")); 109 exit(1); 110 } 111 112 hdr.offset_blockmap = lseek(fd, 0, SEEK_CUR); 113 retval = ext2fs_image_bitmap_write(fs, fd, 0); 114 if (retval) { 115 com_err(program_name, retval, _("while writing block bitmap")); 116 exit(1); 117 } 118 119 hdr.offset_inodemap = lseek(fd, 0, SEEK_CUR); 120 retval = ext2fs_image_bitmap_write(fs, fd, IMAGER_FLAG_INODEMAP); 121 if (retval) { 122 com_err(program_name, retval, _("while writing inode bitmap")); 123 exit(1); 124 } 125 126 hdr.magic_number = EXT2_ET_MAGIC_E2IMAGE; 127 strcpy(hdr.magic_descriptor, "Ext2 Image 1.0"); 128 gethostname(hdr.fs_hostname, sizeof(hdr.fs_hostname)); 129 strncat(hdr.fs_device_name, device_name, sizeof(hdr.fs_device_name)); 130 hdr.fs_device_name[sizeof(hdr.fs_device_name) - 1] = 0; 131 hdr.fs_blocksize = fs->blocksize; 132 133 if (stat(device_name, &st) == 0) 134 hdr.fs_device = st.st_rdev; 135 136 if (fstat(fd, &st) == 0) { 137 hdr.image_device = st.st_dev; 138 hdr.image_inode = st.st_ino; 139 } 140 memcpy(hdr.fs_uuid, fs->super->s_uuid, sizeof(hdr.fs_uuid)); 141 142 hdr.image_time = time(0); 143 write_header(fd, &hdr, fs->blocksize); 144} 145 146/* 147 * These set of functions are used to write a RAW image file. 148 */ 149ext2fs_block_bitmap meta_block_map; 150ext2fs_block_bitmap scramble_block_map; /* Directory blocks to be scrambled */ 151 152struct process_block_struct { 153 ext2_ino_t ino; 154 int is_dir; 155}; 156 157/* 158 * These subroutines short circuits ext2fs_get_blocks and 159 * ext2fs_check_directory; we use them since we already have the inode 160 * structure, so there's no point in letting the ext2fs library read 161 * the inode again. 162 */ 163static ino_t stashed_ino = 0; 164static struct ext2_inode *stashed_inode; 165 166static errcode_t meta_get_blocks(ext2_filsys fs EXT2FS_ATTR((unused)), 167 ext2_ino_t ino, 168 blk_t *blocks) 169{ 170 int i; 171 172 if ((ino != stashed_ino) || !stashed_inode) 173 return EXT2_ET_CALLBACK_NOTHANDLED; 174 175 for (i=0; i < EXT2_N_BLOCKS; i++) 176 blocks[i] = stashed_inode->i_block[i]; 177 return 0; 178} 179 180static errcode_t meta_check_directory(ext2_filsys fs EXT2FS_ATTR((unused)), 181 ext2_ino_t ino) 182{ 183 if ((ino != stashed_ino) || !stashed_inode) 184 return EXT2_ET_CALLBACK_NOTHANDLED; 185 186 if (!LINUX_S_ISDIR(stashed_inode->i_mode)) 187 return EXT2_ET_NO_DIRECTORY; 188 return 0; 189} 190 191static errcode_t meta_read_inode(ext2_filsys fs EXT2FS_ATTR((unused)), 192 ext2_ino_t ino, 193 struct ext2_inode *inode) 194{ 195 if ((ino != stashed_ino) || !stashed_inode) 196 return EXT2_ET_CALLBACK_NOTHANDLED; 197 *inode = *stashed_inode; 198 return 0; 199} 200 201static void use_inode_shortcuts(ext2_filsys fs, int bool) 202{ 203 if (bool) { 204 fs->get_blocks = meta_get_blocks; 205 fs->check_directory = meta_check_directory; 206 fs->read_inode = meta_read_inode; 207 stashed_ino = 0; 208 } else { 209 fs->get_blocks = 0; 210 fs->check_directory = 0; 211 fs->read_inode = 0; 212 } 213} 214 215static int process_dir_block(ext2_filsys fs EXT2FS_ATTR((unused)), 216 blk_t *block_nr, 217 e2_blkcnt_t blockcnt EXT2FS_ATTR((unused)), 218 blk_t ref_block EXT2FS_ATTR((unused)), 219 int ref_offset EXT2FS_ATTR((unused)), 220 void *priv_data EXT2FS_ATTR((unused))) 221{ 222 struct process_block_struct *p; 223 224 p = (struct process_block_struct *) priv_data; 225 226 ext2fs_mark_block_bitmap(meta_block_map, *block_nr); 227 if (scramble_block_map && p->is_dir && blockcnt >= 0) 228 ext2fs_mark_block_bitmap(scramble_block_map, *block_nr); 229 return 0; 230} 231 232static int process_file_block(ext2_filsys fs EXT2FS_ATTR((unused)), 233 blk_t *block_nr, 234 e2_blkcnt_t blockcnt, 235 blk_t ref_block EXT2FS_ATTR((unused)), 236 int ref_offset EXT2FS_ATTR((unused)), 237 void *priv_data EXT2FS_ATTR((unused))) 238{ 239 if (blockcnt < 0) { 240 ext2fs_mark_block_bitmap(meta_block_map, *block_nr); 241 } 242 return 0; 243} 244 245static void mark_table_blocks(ext2_filsys fs) 246{ 247 blk_t block, b; 248 unsigned int i,j; 249 250 block = fs->super->s_first_data_block; 251 /* 252 * Mark primary superblock 253 */ 254 ext2fs_mark_block_bitmap(meta_block_map, block); 255 256 /* 257 * Mark the primary superblock descriptors 258 */ 259 for (j = 0; j < fs->desc_blocks; j++) { 260 ext2fs_mark_block_bitmap(meta_block_map, 261 ext2fs_descriptor_block_loc(fs, block, j)); 262 } 263 264 for (i = 0; i < fs->group_desc_count; i++) { 265 /* 266 * Mark the blocks used for the inode table 267 */ 268 if (fs->group_desc[i].bg_inode_table) { 269 for (j = 0, b = fs->group_desc[i].bg_inode_table; 270 j < (unsigned) fs->inode_blocks_per_group; 271 j++, b++) 272 ext2fs_mark_block_bitmap(meta_block_map, b); 273 } 274 275 /* 276 * Mark block used for the block bitmap 277 */ 278 if (fs->group_desc[i].bg_block_bitmap) { 279 ext2fs_mark_block_bitmap(meta_block_map, 280 fs->group_desc[i].bg_block_bitmap); 281 } 282 283 /* 284 * Mark block used for the inode bitmap 285 */ 286 if (fs->group_desc[i].bg_inode_bitmap) { 287 ext2fs_mark_block_bitmap(meta_block_map, 288 fs->group_desc[i].bg_inode_bitmap); 289 } 290 block += fs->super->s_blocks_per_group; 291 } 292} 293 294/* 295 * This function returns 1 if the specified block is all zeros 296 */ 297static int check_zero_block(char *buf, int blocksize) 298{ 299 char *cp = buf; 300 int left = blocksize; 301 302 while (left > 0) { 303 if (*cp++) 304 return 0; 305 left--; 306 } 307 return 1; 308} 309 310static void write_block(int fd, char *buf, int sparse_offset, 311 int blocksize, blk_t block) 312{ 313 int count; 314 errcode_t err; 315 316 if (sparse_offset) { 317#ifdef HAVE_LSEEK64 318 if (lseek64(fd, sparse_offset, SEEK_CUR) < 0) 319 perror("lseek"); 320#else 321 if (lseek(fd, sparse_offset, SEEK_CUR) < 0) 322 perror("lseek"); 323#endif 324 } 325 if (blocksize) { 326 count = write(fd, buf, blocksize); 327 if (count != blocksize) { 328 if (count == -1) 329 err = errno; 330 else 331 err = 0; 332 com_err(program_name, err, "error writing block %d", 333 block); 334 } 335 } 336} 337 338int name_id[256]; 339 340static void scramble_dir_block(ext2_filsys fs, blk_t blk, char *buf) 341{ 342 char *p, *end, *cp; 343 struct ext2_dir_entry_2 *dirent; 344 int rec_len, id, len; 345 346 end = buf + fs->blocksize; 347 for (p = buf; p < end-8; p += rec_len) { 348 dirent = (struct ext2_dir_entry_2 *) p; 349 rec_len = dirent->rec_len; 350#ifdef EXT2FS_ENABLE_SWAPFS 351 if (fs->flags & EXT2_FLAG_SWAP_BYTES) 352 rec_len = ext2fs_swab16(rec_len); 353#endif 354#if 0 355 printf("rec_len = %d, name_len = %d\n", rec_len, dirent->name_len); 356#endif 357 if (rec_len < 8 || (rec_len % 4) || 358 (p+rec_len > end)) { 359 printf("Corrupt directory block %lu: " 360 "bad rec_len (%d)\n", blk, rec_len); 361 rec_len = end - p; 362#ifdef EXT2FS_ENABLE_SWAPFS 363 if (fs->flags & EXT2_FLAG_SWAP_BYTES) 364 dirent->rec_len = ext2fs_swab16(rec_len); 365#endif 366 continue; 367 } 368 if (dirent->name_len + 8 > rec_len) { 369 printf("Corrupt directory block %lu: " 370 "bad name_len (%d)\n", blk, dirent->name_len); 371 dirent->name_len = rec_len - 8; 372 continue; 373 } 374 if (dirent->name_len==1 && p[8] == '.') 375 continue; 376 if (dirent->name_len==2 && p[8] == '.' && p[9] == '.') 377 continue; 378 379 cp = p+8; 380 memset(cp, 'A', dirent->name_len); 381 len = rec_len - dirent->name_len - 8; 382 if (len > 0) 383 memset(cp+dirent->name_len, 0, len); 384 len = dirent->name_len; 385 id = name_id[len]++; 386 while ((len > 0) && (id > 0)) { 387 *cp += id % 26; 388 id = id / 26; 389 cp++; 390 len--; 391 } 392 } 393} 394 395static void output_meta_data_blocks(ext2_filsys fs, int fd) 396{ 397 errcode_t retval; 398 blk_t blk; 399 char *buf, *zero_buf; 400 int sparse = 0; 401 402 buf = malloc(fs->blocksize); 403 if (!buf) { 404 com_err(program_name, ENOMEM, "while allocating buffer"); 405 exit(1); 406 } 407 zero_buf = malloc(fs->blocksize); 408 if (!zero_buf) { 409 com_err(program_name, ENOMEM, "while allocating buffer"); 410 exit(1); 411 } 412 memset(zero_buf, 0, fs->blocksize); 413 for (blk = 0; blk < fs->super->s_blocks_count; blk++) { 414 if ((blk >= fs->super->s_first_data_block) && 415 ext2fs_test_block_bitmap(meta_block_map, blk)) { 416 retval = io_channel_read_blk(fs->io, blk, 1, buf); 417 if (retval) { 418 com_err(program_name, retval, 419 "error reading block %d", blk); 420 } 421 if (scramble_block_map && 422 ext2fs_test_block_bitmap(scramble_block_map, blk)) 423 scramble_dir_block(fs, blk, buf); 424 if ((fd != 1) && check_zero_block(buf, fs->blocksize)) 425 goto sparse_write; 426 write_block(fd, buf, sparse, fs->blocksize, blk); 427 sparse = 0; 428 } else { 429 sparse_write: 430 if (fd == 1) { 431 write_block(fd, zero_buf, 0, 432 fs->blocksize, blk); 433 continue; 434 } 435 sparse += fs->blocksize; 436 if (sparse >= 1024*1024) { 437 write_block(fd, 0, sparse, 0, 0); 438 sparse = 0; 439 } 440 } 441 } 442 write_block(fd, zero_buf, sparse, 1, -1); 443} 444 445static void write_raw_image_file(ext2_filsys fs, int fd, int scramble_flag) 446{ 447 struct process_block_struct pb; 448 struct ext2_inode inode; 449 ext2_inode_scan scan; 450 ext2_ino_t ino; 451 errcode_t retval; 452 char * block_buf; 453 454 retval = ext2fs_allocate_block_bitmap(fs, "in-use block map", 455 &meta_block_map); 456 if (retval) { 457 com_err(program_name, retval, "while allocating block bitmap"); 458 exit(1); 459 } 460 461 if (scramble_flag) { 462 retval = ext2fs_allocate_block_bitmap(fs, "scramble block map", 463 &scramble_block_map); 464 if (retval) { 465 com_err(program_name, retval, 466 "while allocating scramble block bitmap"); 467 exit(1); 468 } 469 } 470 471 mark_table_blocks(fs); 472 473 retval = ext2fs_open_inode_scan(fs, 0, &scan); 474 if (retval) { 475 com_err(program_name, retval, _("while opening inode scan")); 476 exit(1); 477 } 478 479 block_buf = malloc(fs->blocksize * 3); 480 if (!block_buf) { 481 com_err(program_name, 0, "Can't allocate block buffer"); 482 exit(1); 483 } 484 485 use_inode_shortcuts(fs, 1); 486 stashed_inode = &inode; 487 while (1) { 488 retval = ext2fs_get_next_inode(scan, &ino, &inode); 489 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE) 490 continue; 491 if (retval) { 492 com_err(program_name, retval, 493 _("while getting next inode")); 494 exit(1); 495 } 496 if (ino == 0) 497 break; 498 if (!inode.i_links_count) 499 continue; 500 if (inode.i_file_acl) { 501 ext2fs_mark_block_bitmap(meta_block_map, 502 inode.i_file_acl); 503 } 504 if (!ext2fs_inode_has_valid_blocks(&inode)) 505 continue; 506 507 stashed_ino = ino; 508 pb.ino = ino; 509 pb.is_dir = LINUX_S_ISDIR(inode.i_mode); 510 if (LINUX_S_ISDIR(inode.i_mode) || 511 (LINUX_S_ISLNK(inode.i_mode) && 512 ext2fs_inode_has_valid_blocks(&inode)) || 513 ino == fs->super->s_journal_inum) { 514 retval = ext2fs_block_iterate2(fs, ino, 0, 515 block_buf, process_dir_block, &pb); 516 if (retval) { 517 com_err(program_name, retval, 518 "while iterating over inode %d", 519 ino); 520 exit(1); 521 } 522 } else { 523 if (inode.i_block[EXT2_IND_BLOCK] || 524 inode.i_block[EXT2_DIND_BLOCK] || 525 inode.i_block[EXT2_TIND_BLOCK]) { 526 retval = ext2fs_block_iterate2(fs, 527 ino, 0, block_buf, 528 process_file_block, &pb); 529 if (retval) { 530 com_err(program_name, retval, 531 "while iterating over %d", ino); 532 exit(1); 533 } 534 } 535 } 536 } 537 use_inode_shortcuts(fs, 0); 538 output_meta_data_blocks(fs, fd); 539} 540 541static void install_image(char *device, char *image_fn, int raw_flag) 542{ 543 errcode_t retval; 544 ext2_filsys fs; 545 int open_flag = EXT2_FLAG_IMAGE_FILE; 546 int fd = 0; 547 io_manager io_ptr; 548 io_channel io, image_io; 549 550 if (raw_flag) { 551 com_err(program_name, 0, "Raw images cannot be installed"); 552 exit(1); 553 } 554 555#ifdef CONFIG_TESTIO_DEBUG 556 io_ptr = test_io_manager; 557 test_io_backing_manager = unix_io_manager; 558#else 559 io_ptr = unix_io_manager; 560#endif 561 562 retval = ext2fs_open (image_fn, open_flag, 0, 0, 563 io_ptr, &fs); 564 if (retval) { 565 com_err (program_name, retval, _("while trying to open %s"), 566 image_fn); 567 exit(1); 568 } 569 570 retval = ext2fs_read_bitmaps (fs); 571 if (retval) { 572 com_err(program_name, retval, "error reading bitmaps"); 573 exit(1); 574 } 575 576 577 fd = open(image_fn, O_RDONLY); 578 if (fd < 0) { 579 perror(image_fn); 580 exit(1); 581 } 582 583 retval = io_ptr->open(device, IO_FLAG_RW, &io); 584 if (retval) { 585 com_err(device, 0, "while opening device file"); 586 exit(1); 587 } 588 589 image_io = fs->io; 590 591 ext2fs_rewrite_to_io(fs, io); 592 593 if (lseek(fd, fs->image_header->offset_inode, SEEK_SET) < 0) { 594 perror("lseek"); 595 exit(1); 596 } 597 598 retval = ext2fs_image_inode_read(fs, fd, 0); 599 if (retval) { 600 com_err(image_fn, 0, "while restoring the image table"); 601 exit(1); 602 } 603 604 ext2fs_close (fs); 605 exit (0); 606} 607 608int main (int argc, char ** argv) 609{ 610 int c; 611 errcode_t retval; 612 ext2_filsys fs; 613 char *image_fn; 614 int open_flag = 0; 615 int raw_flag = 0; 616 int install_flag = 0; 617 int scramble_flag = 0; 618 int fd = 0; 619 620#ifdef ENABLE_NLS 621 setlocale(LC_MESSAGES, ""); 622 setlocale(LC_CTYPE, ""); 623 bindtextdomain(NLS_CAT_NAME, LOCALEDIR); 624 textdomain(NLS_CAT_NAME); 625#endif 626 fprintf (stderr, "e2image %s (%s)\n", E2FSPROGS_VERSION, 627 E2FSPROGS_DATE); 628 if (argc && *argv) 629 program_name = *argv; 630 initialize_ext2_error_table(); 631 while ((c = getopt (argc, argv, "rsI")) != EOF) 632 switch (c) { 633 case 'r': 634 raw_flag++; 635 break; 636 case 's': 637 scramble_flag++; 638 break; 639 case 'I': 640 install_flag++; 641 break; 642 default: 643 usage(); 644 } 645 if (optind != argc - 2 ) 646 usage(); 647 device_name = argv[optind]; 648 image_fn = argv[optind+1]; 649 650 if (install_flag) { 651 install_image(device_name, image_fn, raw_flag); 652 exit (0); 653 } 654 655 retval = ext2fs_open (device_name, open_flag, 0, 0, 656 unix_io_manager, &fs); 657 if (retval) { 658 com_err (program_name, retval, _("while trying to open %s"), 659 device_name); 660 fputs(_("Couldn't find valid filesystem superblock.\n"), stdout); 661 exit(1); 662 } 663 664 if (strcmp(image_fn, "-") == 0) 665 fd = 1; 666 else { 667#ifdef HAVE_OPEN64 668 fd = open64(image_fn, O_CREAT|O_TRUNC|O_WRONLY, 0600); 669#else 670 fd = open(image_fn, O_CREAT|O_TRUNC|O_WRONLY, 0600); 671#endif 672 if (fd < 0) { 673 com_err(program_name, errno, 674 _("while trying to open %s"), argv[optind+1]); 675 exit(1); 676 } 677 } 678 679 if (raw_flag) 680 write_raw_image_file(fs, fd, scramble_flag); 681 else 682 write_image_file(fs, fd); 683 684 ext2fs_close (fs); 685 exit (0); 686} 687