e2image.c revision d7eee82910b2e62728dca18def04c3ad5f680345
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 first_block, b; 248 unsigned int i,j; 249 250 first_block = fs->super->s_first_data_block; 251 /* 252 * Mark primary superblock 253 */ 254 ext2fs_mark_block_bitmap(meta_block_map, first_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, first_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 } 291} 292 293/* 294 * This function returns 1 if the specified block is all zeros 295 */ 296static int check_zero_block(char *buf, int blocksize) 297{ 298 char *cp = buf; 299 int left = blocksize; 300 301 while (left > 0) { 302 if (*cp++) 303 return 0; 304 left--; 305 } 306 return 1; 307} 308 309static void write_block(int fd, char *buf, int sparse_offset, 310 int blocksize, blk_t block) 311{ 312 int count; 313 errcode_t err; 314 315 if (sparse_offset) { 316#ifdef HAVE_LSEEK64 317 if (lseek64(fd, sparse_offset, SEEK_CUR) < 0) 318 perror("lseek"); 319#else 320 if (lseek(fd, sparse_offset, SEEK_CUR) < 0) 321 perror("lseek"); 322#endif 323 } 324 if (blocksize) { 325 count = write(fd, buf, blocksize); 326 if (count != blocksize) { 327 if (count == -1) 328 err = errno; 329 else 330 err = 0; 331 com_err(program_name, err, "error writing block %u", 332 block); 333 } 334 } 335} 336 337int name_id[256]; 338 339static void scramble_dir_block(ext2_filsys fs, blk_t blk, char *buf) 340{ 341 char *p, *end, *cp; 342 struct ext2_dir_entry_2 *dirent; 343 int rec_len, id, len; 344 345 end = buf + fs->blocksize; 346 for (p = buf; p < end-8; p += rec_len) { 347 dirent = (struct ext2_dir_entry_2 *) p; 348 rec_len = dirent->rec_len; 349#ifdef EXT2FS_ENABLE_SWAPFS 350 if (fs->flags & EXT2_FLAG_SWAP_BYTES) 351 rec_len = ext2fs_swab16(rec_len); 352#endif 353#if 0 354 printf("rec_len = %d, name_len = %d\n", rec_len, dirent->name_len); 355#endif 356 if (rec_len < 8 || (rec_len % 4) || 357 (p+rec_len > end)) { 358 printf("Corrupt directory block %lu: " 359 "bad rec_len (%d)\n", (unsigned long) blk, 360 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", (unsigned long) blk, 371 dirent->name_len); 372 dirent->name_len = rec_len - 8; 373 continue; 374 } 375 cp = p+8; 376 len = rec_len - dirent->name_len - 8; 377 if (len > 0) 378 memset(cp+dirent->name_len, 0, len); 379 if (dirent->name_len==1 && cp[0] == '.') 380 continue; 381 if (dirent->name_len==2 && cp[0] == '.' && cp[1] == '.') 382 continue; 383 384 memset(cp, 'A', dirent->name_len); 385 len = dirent->name_len; 386 id = name_id[len]++; 387 while ((len > 0) && (id > 0)) { 388 *cp += id % 26; 389 id = id / 26; 390 cp++; 391 len--; 392 } 393 } 394} 395 396static void output_meta_data_blocks(ext2_filsys fs, int fd) 397{ 398 errcode_t retval; 399 blk_t blk; 400 char *buf, *zero_buf; 401 int sparse = 0; 402 403 buf = malloc(fs->blocksize); 404 if (!buf) { 405 com_err(program_name, ENOMEM, "while allocating buffer"); 406 exit(1); 407 } 408 zero_buf = malloc(fs->blocksize); 409 if (!zero_buf) { 410 com_err(program_name, ENOMEM, "while allocating buffer"); 411 exit(1); 412 } 413 memset(zero_buf, 0, fs->blocksize); 414 for (blk = 0; blk < fs->super->s_blocks_count; blk++) { 415 if ((blk >= fs->super->s_first_data_block) && 416 ext2fs_test_block_bitmap(meta_block_map, blk)) { 417 retval = io_channel_read_blk(fs->io, blk, 1, buf); 418 if (retval) { 419 com_err(program_name, retval, 420 "error reading block %u", blk); 421 } 422 if (scramble_block_map && 423 ext2fs_test_block_bitmap(scramble_block_map, blk)) 424 scramble_dir_block(fs, blk, buf); 425 if ((fd != 1) && check_zero_block(buf, fs->blocksize)) 426 goto sparse_write; 427 write_block(fd, buf, sparse, fs->blocksize, blk); 428 sparse = 0; 429 } else { 430 sparse_write: 431 if (fd == 1) { 432 write_block(fd, zero_buf, 0, 433 fs->blocksize, blk); 434 continue; 435 } 436 sparse += fs->blocksize; 437 if (sparse >= 1024*1024) { 438 write_block(fd, 0, sparse, 0, 0); 439 sparse = 0; 440 } 441 } 442 } 443 write_block(fd, zero_buf, sparse, 1, -1); 444 free(zero_buf); 445 free(buf); 446} 447 448static void write_raw_image_file(ext2_filsys fs, int fd, int scramble_flag) 449{ 450 struct process_block_struct pb; 451 struct ext2_inode inode; 452 ext2_inode_scan scan; 453 ext2_ino_t ino; 454 errcode_t retval; 455 char * block_buf; 456 457 retval = ext2fs_allocate_block_bitmap(fs, "in-use block map", 458 &meta_block_map); 459 if (retval) { 460 com_err(program_name, retval, "while allocating block bitmap"); 461 exit(1); 462 } 463 464 if (scramble_flag) { 465 retval = ext2fs_allocate_block_bitmap(fs, "scramble block map", 466 &scramble_block_map); 467 if (retval) { 468 com_err(program_name, retval, 469 "while allocating scramble block bitmap"); 470 exit(1); 471 } 472 } 473 474 mark_table_blocks(fs); 475 476 retval = ext2fs_open_inode_scan(fs, 0, &scan); 477 if (retval) { 478 com_err(program_name, retval, _("while opening inode scan")); 479 exit(1); 480 } 481 482 block_buf = malloc(fs->blocksize * 3); 483 if (!block_buf) { 484 com_err(program_name, 0, "Can't allocate block buffer"); 485 exit(1); 486 } 487 488 use_inode_shortcuts(fs, 1); 489 stashed_inode = &inode; 490 while (1) { 491 retval = ext2fs_get_next_inode(scan, &ino, &inode); 492 if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE) 493 continue; 494 if (retval) { 495 com_err(program_name, retval, 496 _("while getting next inode")); 497 exit(1); 498 } 499 if (ino == 0) 500 break; 501 if (!inode.i_links_count) 502 continue; 503 if (inode.i_file_acl) { 504 ext2fs_mark_block_bitmap(meta_block_map, 505 inode.i_file_acl); 506 } 507 if (!ext2fs_inode_has_valid_blocks(&inode)) 508 continue; 509 510 stashed_ino = ino; 511 pb.ino = ino; 512 pb.is_dir = LINUX_S_ISDIR(inode.i_mode); 513 if (LINUX_S_ISDIR(inode.i_mode) || 514 (LINUX_S_ISLNK(inode.i_mode) && 515 ext2fs_inode_has_valid_blocks(&inode)) || 516 ino == fs->super->s_journal_inum) { 517 retval = ext2fs_block_iterate2(fs, ino, 0, 518 block_buf, process_dir_block, &pb); 519 if (retval) { 520 com_err(program_name, retval, 521 "while iterating over inode %u", 522 ino); 523 exit(1); 524 } 525 } else { 526 if (inode.i_block[EXT2_IND_BLOCK] || 527 inode.i_block[EXT2_DIND_BLOCK] || 528 inode.i_block[EXT2_TIND_BLOCK]) { 529 retval = ext2fs_block_iterate2(fs, 530 ino, 0, block_buf, 531 process_file_block, &pb); 532 if (retval) { 533 com_err(program_name, retval, 534 "while iterating over inode %u", ino); 535 exit(1); 536 } 537 } 538 } 539 } 540 use_inode_shortcuts(fs, 0); 541 output_meta_data_blocks(fs, fd); 542 free(block_buf); 543} 544 545static void install_image(char *device, char *image_fn, int raw_flag) 546{ 547 errcode_t retval; 548 ext2_filsys fs; 549 int open_flag = EXT2_FLAG_IMAGE_FILE; 550 int fd = 0; 551 io_manager io_ptr; 552 io_channel io, image_io; 553 554 if (raw_flag) { 555 com_err(program_name, 0, "Raw images cannot be installed"); 556 exit(1); 557 } 558 559#ifdef CONFIG_TESTIO_DEBUG 560 io_ptr = test_io_manager; 561 test_io_backing_manager = unix_io_manager; 562#else 563 io_ptr = unix_io_manager; 564#endif 565 566 retval = ext2fs_open (image_fn, open_flag, 0, 0, 567 io_ptr, &fs); 568 if (retval) { 569 com_err (program_name, retval, _("while trying to open %s"), 570 image_fn); 571 exit(1); 572 } 573 574 retval = ext2fs_read_bitmaps (fs); 575 if (retval) { 576 com_err(program_name, retval, "error reading bitmaps"); 577 exit(1); 578 } 579 580 581 fd = open(image_fn, O_RDONLY); 582 if (fd < 0) { 583 perror(image_fn); 584 exit(1); 585 } 586 587 retval = io_ptr->open(device, IO_FLAG_RW, &io); 588 if (retval) { 589 com_err(device, 0, "while opening device file"); 590 exit(1); 591 } 592 593 image_io = fs->io; 594 595 ext2fs_rewrite_to_io(fs, io); 596 597 if (lseek(fd, fs->image_header->offset_inode, SEEK_SET) < 0) { 598 perror("lseek"); 599 exit(1); 600 } 601 602 retval = ext2fs_image_inode_read(fs, fd, 0); 603 if (retval) { 604 com_err(image_fn, 0, "while restoring the image table"); 605 exit(1); 606 } 607 608 ext2fs_close (fs); 609 exit (0); 610} 611 612int main (int argc, char ** argv) 613{ 614 int c; 615 errcode_t retval; 616 ext2_filsys fs; 617 char *image_fn; 618 int open_flag = 0; 619 int raw_flag = 0; 620 int install_flag = 0; 621 int scramble_flag = 0; 622 int fd = 0; 623 624#ifdef ENABLE_NLS 625 setlocale(LC_MESSAGES, ""); 626 setlocale(LC_CTYPE, ""); 627 bindtextdomain(NLS_CAT_NAME, LOCALEDIR); 628 textdomain(NLS_CAT_NAME); 629#endif 630 fprintf (stderr, "e2image %s (%s)\n", E2FSPROGS_VERSION, 631 E2FSPROGS_DATE); 632 if (argc && *argv) 633 program_name = *argv; 634 add_error_table(&et_ext2_error_table); 635 while ((c = getopt (argc, argv, "rsI")) != EOF) 636 switch (c) { 637 case 'r': 638 raw_flag++; 639 break; 640 case 's': 641 scramble_flag++; 642 break; 643 case 'I': 644 install_flag++; 645 break; 646 default: 647 usage(); 648 } 649 if (optind != argc - 2 ) 650 usage(); 651 device_name = argv[optind]; 652 image_fn = argv[optind+1]; 653 654 if (install_flag) { 655 install_image(device_name, image_fn, raw_flag); 656 exit (0); 657 } 658 659 retval = ext2fs_open (device_name, open_flag, 0, 0, 660 unix_io_manager, &fs); 661 if (retval) { 662 com_err (program_name, retval, _("while trying to open %s"), 663 device_name); 664 fputs(_("Couldn't find valid filesystem superblock.\n"), stdout); 665 exit(1); 666 } 667 668 if (strcmp(image_fn, "-") == 0) 669 fd = 1; 670 else { 671#ifdef HAVE_OPEN64 672 fd = open64(image_fn, O_CREAT|O_TRUNC|O_WRONLY, 0600); 673#else 674 fd = open(image_fn, O_CREAT|O_TRUNC|O_WRONLY, 0600); 675#endif 676 if (fd < 0) { 677 com_err(program_name, errno, 678 _("while trying to open %s"), argv[optind+1]); 679 exit(1); 680 } 681 } 682 683 if (raw_flag) 684 write_raw_image_file(fs, fd, scramble_flag); 685 else 686 write_image_file(fs, fd); 687 688 ext2fs_close (fs); 689 remove_error_table(&et_ext2_error_table); 690 exit (0); 691} 692