1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2020 Bootlin
5 * Author: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
7 * sqfs.c: SquashFS filesystem implementation
10 #include <asm/unaligned.h>
13 #include <linux/types.h>
14 #include <linux/byteorder/little_endian.h>
15 #include <linux/byteorder/generic.h>
22 #include "sqfs_decompressor.h"
23 #include "sqfs_filesystem.h"
24 #include "sqfs_utils.h"
26 static struct squashfs_ctxt ctxt;
28 static int sqfs_disk_read(__u32 block, __u32 nr_blocks, void *buf)
35 ret = blk_dread(ctxt.cur_dev, ctxt.cur_part_info.start + block,
44 static int sqfs_read_sblk(struct squashfs_super_block **sblk)
46 *sblk = malloc_cache_aligned(ctxt.cur_dev->blksz);
50 if (sqfs_disk_read(0, 1, *sblk) != 1) {
58 static int sqfs_count_tokens(const char *filename)
60 int token_count = 1, l;
62 for (l = 1; l < strlen(filename); l++) {
63 if (filename[l] == '/')
67 /* Ignore trailing '/' in path */
68 if (filename[strlen(filename) - 1] == '/')
78 * Calculates how many blocks are needed for the buffer used in sqfs_disk_read.
79 * The memory section (e.g. inode table) start offset and its end (i.e. the next
80 * table start) must be specified. It also calculates the offset from which to
81 * start reading the buffer.
83 static int sqfs_calc_n_blks(__le64 start, __le64 end, u64 *offset)
85 u64 start_, table_size;
87 table_size = le64_to_cpu(end) - le64_to_cpu(start);
88 start_ = le64_to_cpu(start) / ctxt.cur_dev->blksz;
89 *offset = le64_to_cpu(start) - (start_ * ctxt.cur_dev->blksz);
91 return DIV_ROUND_UP(table_size + *offset, ctxt.cur_dev->blksz);
95 * Retrieves fragment block entry and returns true if the fragment block is
98 static int sqfs_frag_lookup(u32 inode_fragment_index,
99 struct squashfs_fragment_block_entry *e)
101 u64 start, n_blks, src_len, table_offset, start_block;
102 unsigned char *metadata_buffer, *metadata, *table;
103 struct squashfs_fragment_block_entry *entries;
104 struct squashfs_super_block *sblk = ctxt.sblk;
105 unsigned long dest_len;
106 int block, offset, ret;
109 if (inode_fragment_index >= get_unaligned_le32(&sblk->fragments))
112 start = get_unaligned_le64(&sblk->fragment_table_start) /
114 n_blks = sqfs_calc_n_blks(sblk->fragment_table_start,
115 sblk->export_table_start,
118 /* Allocate a proper sized buffer to store the fragment index table */
119 table = malloc_cache_aligned(n_blks * ctxt.cur_dev->blksz);
123 if (sqfs_disk_read(start, n_blks, table) < 0) {
128 block = SQFS_FRAGMENT_INDEX(inode_fragment_index);
129 offset = SQFS_FRAGMENT_INDEX_OFFSET(inode_fragment_index);
132 * Get the start offset of the metadata block that contains the right
133 * fragment block entry
135 start_block = get_unaligned_le64(table + table_offset + block *
138 start = start_block / ctxt.cur_dev->blksz;
139 n_blks = sqfs_calc_n_blks(cpu_to_le64(start_block),
140 sblk->fragment_table_start, &table_offset);
142 metadata_buffer = malloc_cache_aligned(n_blks * ctxt.cur_dev->blksz);
143 if (!metadata_buffer) {
148 if (sqfs_disk_read(start, n_blks, metadata_buffer) < 0) {
153 /* Every metadata block starts with a 16-bit header */
154 header = get_unaligned_le16(metadata_buffer + table_offset);
155 metadata = metadata_buffer + table_offset + SQFS_HEADER_SIZE;
157 if (!metadata || !header) {
162 entries = malloc(SQFS_METADATA_BLOCK_SIZE);
168 if (SQFS_COMPRESSED_METADATA(header)) {
169 src_len = SQFS_METADATA_SIZE(header);
170 dest_len = SQFS_METADATA_BLOCK_SIZE;
171 ret = sqfs_decompress(&ctxt, entries, &dest_len, metadata,
178 memcpy(entries, metadata, SQFS_METADATA_SIZE(header));
181 *e = entries[offset];
182 ret = SQFS_COMPRESSED_BLOCK(e->size);
187 free(metadata_buffer);
195 * The entry name is a flexible array member, and we don't know its size before
196 * actually reading the entry. So we need a first copy to retrieve this size so
197 * we can finally copy the whole struct.
199 static int sqfs_read_entry(struct squashfs_directory_entry **dest, void *src)
201 struct squashfs_directory_entry *tmp;
205 sz = get_unaligned_le16(src + sizeof(*tmp) - sizeof(u16));
207 * 'src' points to the begin of a directory entry, and 'sz' gets its
208 * 'name_size' member's value. name_size is actually the string
209 * length - 1, so adding 2 compensates this difference and adds space
210 * for the trailling null byte.
212 *dest = malloc(sizeof(*tmp) + sz + 2);
216 memcpy(*dest, src, sizeof(*tmp) + sz + 1);
217 (*dest)->name[sz + 1] = '\0';
222 static int sqfs_get_tokens_length(char **tokens, int count)
227 * 1 is added to the result of strlen to consider the slash separator
228 * between the tokens.
230 for (i = 0; i < count; i++)
231 length += strlen(tokens[i]) + 1;
236 /* Takes a token list and returns a single string with '/' as separator. */
237 static char *sqfs_concat_tokens(char **token_list, int token_count)
240 int i, length = 0, offset = 0;
242 length = sqfs_get_tokens_length(token_list, token_count);
244 result = malloc(length + 1);
245 result[length] = '\0';
247 for (i = 0; i < token_count; i++) {
248 strcpy(result + offset, token_list[i]);
249 offset += strlen(token_list[i]);
250 result[offset++] = '/';
257 * Differently from sqfs_concat_tokens, sqfs_join writes the result into a
258 * previously allocated string, and returns the number of bytes written.
260 static int sqfs_join(char **strings, char *dest, int start, int end,
265 for (i = start; i < end; i++) {
266 strcpy(dest + offset, strings[i]);
267 offset += strlen(strings[i]);
269 dest[offset++] = separator;
276 * Fills the given token list using its size (count) and a source string (str)
278 static int sqfs_tokenize(char **tokens, int count, const char *str)
287 if (!strcmp(strc, "/")) {
288 tokens[0] = strdup(strc);
294 for (j = 0; j < count; j++) {
295 aux = strtok(!j ? strc : NULL, "/");
296 tokens[j] = strdup(aux);
298 for (i = 0; i < j; i++)
313 * Remove last 'updir + 1' tokens from the base path tokens list. This leaves us
314 * with a token list containing only the tokens needed to form the resolved
315 * path, and returns the decremented size of the token list.
317 static int sqfs_clean_base_path(char **base, int count, int updir)
321 for (i = count - updir - 1; i < count; i++)
324 return count - updir - 1;
328 * Given the base ("current dir.") path and the relative one, generate the
331 static char *sqfs_get_abs_path(const char *base, const char *rel)
333 char **base_tokens, **rel_tokens, *resolved = NULL;
334 int ret, bc, rc, i, updir = 0, resolved_size = 0, offset = 0;
336 /* Memory allocation for the token lists */
337 bc = sqfs_count_tokens(base);
338 rc = sqfs_count_tokens(rel);
339 if (bc < 1 || rc < 1)
342 base_tokens = malloc(bc * sizeof(char *));
346 rel_tokens = malloc(rc * sizeof(char *));
350 /* Fill token lists */
351 ret = sqfs_tokenize(base_tokens, bc, base);
355 sqfs_tokenize(rel_tokens, rc, rel);
359 /* count '..' occurrences in target path */
360 for (i = 0; i < rc; i++) {
361 if (!strcmp(rel_tokens[i], ".."))
365 /* Remove the last token and the '..' occurrences */
366 bc = sqfs_clean_base_path(base_tokens, bc, updir);
370 /* Calculate resolved path size */
374 resolved_size += sqfs_get_tokens_length(base_tokens, bc) +
375 sqfs_get_tokens_length(rel_tokens, rc);
377 resolved = malloc(resolved_size + 1);
379 goto free_r_tokens_loop;
381 /* Set resolved path */
382 memset(resolved, '\0', resolved_size + 1);
383 offset += sqfs_join(base_tokens, resolved + offset, 0, bc, '/');
384 resolved[offset++] = '/';
385 offset += sqfs_join(rel_tokens, resolved + offset, updir, rc, '/');
388 for (i = 0; i < rc; i++)
390 for (i = 0; i < bc; i++)
391 free(base_tokens[i]);
400 static char *sqfs_resolve_symlink(struct squashfs_symlink_inode *sym,
401 const char *base_path)
403 char *resolved, *target;
406 sz = get_unaligned_le32(&sym->symlink_size);
407 target = malloc(sz + 1);
412 * There is no trailling null byte in the symlink's target path, so a
413 * copy is made and a '\0' is added at its end.
416 /* Get target name (relative path) */
417 strncpy(target, sym->symlink, sz);
419 /* Relative -> absolute path conversion */
420 resolved = sqfs_get_abs_path(base_path, target);
428 * m_list contains each metadata block's position, and m_count is the number of
429 * elements of m_list. Those metadata blocks come from the compressed directory
432 static int sqfs_search_dir(struct squashfs_dir_stream *dirs, char **token_list,
433 int token_count, u32 *m_list, int m_count)
435 struct squashfs_super_block *sblk = ctxt.sblk;
436 char *path, *target, **sym_tokens, *res, *rem;
437 int j, ret, new_inode_number, offset;
438 struct squashfs_symlink_inode *sym;
439 struct squashfs_ldir_inode *ldir;
440 struct squashfs_dir_inode *dir;
441 struct fs_dir_stream *dirsp;
442 struct fs_dirent *dent;
443 unsigned char *table;
445 dirsp = (struct fs_dir_stream *)dirs;
447 /* Start by root inode */
448 table = sqfs_find_inode(dirs->inode_table, le32_to_cpu(sblk->inodes),
449 sblk->inodes, sblk->block_size);
451 dir = (struct squashfs_dir_inode *)table;
452 ldir = (struct squashfs_ldir_inode *)table;
454 /* get directory offset in directory table */
455 offset = sqfs_dir_offset(table, m_list, m_count);
456 dirs->table = &dirs->dir_table[offset];
458 /* Setup directory header */
459 dirs->dir_header = malloc(SQFS_DIR_HEADER_SIZE);
460 if (!dirs->dir_header)
463 memcpy(dirs->dir_header, dirs->table, SQFS_DIR_HEADER_SIZE);
465 /* Initialize squashfs_dir_stream members */
466 dirs->table += SQFS_DIR_HEADER_SIZE;
467 dirs->size = get_unaligned_le16(&dir->file_size) - SQFS_DIR_HEADER_SIZE;
468 dirs->entry_count = dirs->dir_header->count + 1;
470 /* No path given -> root directory */
471 if (!strcmp(token_list[0], "/")) {
472 dirs->table = &dirs->dir_table[offset];
473 memcpy(&dirs->i_dir, dir, sizeof(*dir));
477 for (j = 0; j < token_count; j++) {
478 if (!sqfs_is_dir(get_unaligned_le16(&dir->inode_type))) {
479 printf("** Cannot find directory. **\n");
483 while (!sqfs_readdir(dirsp, &dent)) {
484 ret = strcmp(dent->name, token_list[j]);
491 printf("** Cannot find directory. **\n");
495 /* Redefine inode as the found token */
496 new_inode_number = dirs->entry->inode_offset +
497 dirs->dir_header->inode_number;
499 /* Get reference to inode in the inode table */
500 table = sqfs_find_inode(dirs->inode_table, new_inode_number,
501 sblk->inodes, sblk->block_size);
502 dir = (struct squashfs_dir_inode *)table;
504 /* Check for symbolic link and inode type sanity */
505 if (get_unaligned_le16(&dir->inode_type) == SQFS_SYMLINK_TYPE) {
506 sym = (struct squashfs_symlink_inode *)table;
507 /* Get first j + 1 tokens */
508 path = sqfs_concat_tokens(token_list, j + 1);
509 /* Resolve for these tokens */
510 target = sqfs_resolve_symlink(sym, path);
511 /* Join remaining tokens */
512 rem = sqfs_concat_tokens(token_list + j + 1, token_count -
514 /* Concatenate remaining tokens and symlink's target */
515 res = malloc(strlen(rem) + strlen(target) + 1);
517 res[strlen(target)] = '/';
518 strcpy(res + strlen(target) + 1, rem);
519 token_count = sqfs_count_tokens(res);
524 sym_tokens = malloc(token_count * sizeof(char *));
528 /* Fill tokens list */
529 ret = sqfs_tokenize(sym_tokens, token_count, res);
534 ret = sqfs_search_dir(dirs, sym_tokens, token_count,
537 } else if (!sqfs_is_dir(get_unaligned_le16(&dir->inode_type))) {
538 printf("** Cannot find directory. **\n");
543 /* Check if it is an extended dir. */
544 if (get_unaligned_le16(&dir->inode_type) == SQFS_LDIR_TYPE)
545 ldir = (struct squashfs_ldir_inode *)table;
547 /* Get dir. offset into the directory table */
548 offset = sqfs_dir_offset(table, m_list, m_count);
549 dirs->table = &dirs->dir_table[offset];
551 /* Copy directory header */
552 memcpy(dirs->dir_header, &dirs->dir_table[offset],
553 SQFS_DIR_HEADER_SIZE);
555 /* Check for empty directory */
556 if (sqfs_is_empty_dir(table)) {
557 printf("Empty directory.\n");
559 return SQFS_EMPTY_DIR;
562 dirs->table += SQFS_DIR_HEADER_SIZE;
563 dirs->size = get_unaligned_le16(&dir->file_size);
564 dirs->entry_count = dirs->dir_header->count + 1;
565 dirs->size -= SQFS_DIR_HEADER_SIZE;
569 offset = sqfs_dir_offset(table, m_list, m_count);
570 dirs->table = &dirs->dir_table[offset];
572 if (get_unaligned_le16(&dir->inode_type) == SQFS_DIR_TYPE)
573 memcpy(&dirs->i_dir, dir, sizeof(*dir));
575 memcpy(&dirs->i_ldir, ldir, sizeof(*ldir));
581 * Inode and directory tables are stored as a series of metadata blocks, and
582 * given the compressed size of this table, we can calculate how much metadata
583 * blocks are needed to store the result of the decompression, since a
584 * decompressed metadata block should have a size of 8KiB.
586 static int sqfs_count_metablks(void *table, u32 offset, int table_size)
588 int count = 0, cur_size = 0, ret;
593 ret = sqfs_read_metablock(table, offset + cur_size, &comp,
597 cur_size += data_size + SQFS_HEADER_SIZE;
599 } while (cur_size < table_size);
605 * Storing the metadata blocks header's positions will be useful while looking
606 * for an entry in the directory table, using the reference (index and offset)
607 * given by its inode.
609 static int sqfs_get_metablk_pos(u32 *pos_list, void *table, u32 offset,
612 u32 data_size, cur_size = 0;
619 for (j = 0; j < metablks_count; j++) {
620 ret = sqfs_read_metablock(table, offset + cur_size, &comp,
625 cur_size += data_size + SQFS_HEADER_SIZE;
626 pos_list[j] = cur_size;
632 static int sqfs_read_inode_table(unsigned char **inode_table)
634 struct squashfs_super_block *sblk = ctxt.sblk;
635 u64 start, n_blks, table_offset, table_size;
636 int j, ret = 0, metablks_count;
637 unsigned char *src_table, *itb;
638 u32 src_len, dest_offset = 0;
639 unsigned long dest_len = 0;
642 table_size = get_unaligned_le64(&sblk->directory_table_start) -
643 get_unaligned_le64(&sblk->inode_table_start);
644 start = get_unaligned_le64(&sblk->inode_table_start) /
646 n_blks = sqfs_calc_n_blks(sblk->inode_table_start,
647 sblk->directory_table_start, &table_offset);
649 /* Allocate a proper sized buffer (itb) to store the inode table */
650 itb = malloc_cache_aligned(n_blks * ctxt.cur_dev->blksz);
654 if (sqfs_disk_read(start, n_blks, itb) < 0) {
659 /* Parse inode table (metadata block) header */
660 ret = sqfs_read_metablock(itb, table_offset, &compressed, &src_len);
666 /* Calculate size to store the whole decompressed table */
667 metablks_count = sqfs_count_metablks(itb, table_offset, table_size);
668 if (metablks_count < 1) {
673 *inode_table = malloc(metablks_count * SQFS_METADATA_BLOCK_SIZE);
679 src_table = itb + table_offset + SQFS_HEADER_SIZE;
681 /* Extract compressed Inode table */
682 for (j = 0; j < metablks_count; j++) {
683 sqfs_read_metablock(itb, table_offset, &compressed, &src_len);
685 dest_len = SQFS_METADATA_BLOCK_SIZE;
686 ret = sqfs_decompress(&ctxt, *inode_table +
687 dest_offset, &dest_len,
694 dest_offset += dest_len;
696 memcpy(*inode_table + (j * SQFS_METADATA_BLOCK_SIZE),
701 * Offsets to the decompression destination, to the metadata
702 * buffer 'itb' and to the decompression source, respectively.
705 table_offset += src_len + SQFS_HEADER_SIZE;
706 src_table += src_len + SQFS_HEADER_SIZE;
715 static int sqfs_read_directory_table(unsigned char **dir_table, u32 **pos_list)
717 u64 start, n_blks, table_offset, table_size;
718 struct squashfs_super_block *sblk = ctxt.sblk;
719 int j, ret = 0, metablks_count = -1;
720 unsigned char *src_table, *dtb;
721 u32 src_len, dest_offset = 0;
722 unsigned long dest_len = 0;
725 /* DIRECTORY TABLE */
726 table_size = get_unaligned_le64(&sblk->fragment_table_start) -
727 get_unaligned_le64(&sblk->directory_table_start);
728 start = get_unaligned_le64(&sblk->directory_table_start) /
730 n_blks = sqfs_calc_n_blks(sblk->directory_table_start,
731 sblk->fragment_table_start, &table_offset);
733 /* Allocate a proper sized buffer (dtb) to store the directory table */
734 dtb = malloc_cache_aligned(n_blks * ctxt.cur_dev->blksz);
738 if (sqfs_disk_read(start, n_blks, dtb) < 0)
741 /* Parse directory table (metadata block) header */
742 ret = sqfs_read_metablock(dtb, table_offset, &compressed, &src_len);
746 /* Calculate total size to store the whole decompressed table */
747 metablks_count = sqfs_count_metablks(dtb, table_offset, table_size);
748 if (metablks_count < 1)
751 *dir_table = malloc(metablks_count * SQFS_METADATA_BLOCK_SIZE);
755 *pos_list = malloc(metablks_count * sizeof(u32));
761 ret = sqfs_get_metablk_pos(*pos_list, dtb, table_offset,
770 src_table = dtb + table_offset + SQFS_HEADER_SIZE;
772 /* Extract compressed Directory table */
774 for (j = 0; j < metablks_count; j++) {
775 sqfs_read_metablock(dtb, table_offset, &compressed, &src_len);
777 dest_len = SQFS_METADATA_BLOCK_SIZE;
778 ret = sqfs_decompress(&ctxt, *dir_table +
779 (j * SQFS_METADATA_BLOCK_SIZE),
780 &dest_len, src_table, src_len);
787 if (dest_len < SQFS_METADATA_BLOCK_SIZE) {
788 dest_offset += dest_len;
792 dest_offset += dest_len;
794 memcpy(*dir_table + (j * SQFS_METADATA_BLOCK_SIZE),
799 * Offsets to the decompression destination, to the metadata
800 * buffer 'dtb' and to the decompression source, respectively.
802 table_offset += src_len + SQFS_HEADER_SIZE;
803 src_table += src_len + SQFS_HEADER_SIZE;
809 return metablks_count;
812 int sqfs_opendir(const char *filename, struct fs_dir_stream **dirsp)
814 unsigned char *inode_table = NULL, *dir_table = NULL;
815 int j, token_count, ret = 0, metablks_count;
816 struct squashfs_dir_stream *dirs;
817 char **token_list, *path;
818 u32 *pos_list = NULL;
820 dirs = malloc(sizeof(*dirs));
824 ret = sqfs_read_inode_table(&inode_table);
828 metablks_count = sqfs_read_directory_table(&dir_table, &pos_list);
829 if (metablks_count < 1)
832 /* Tokenize filename */
833 token_count = sqfs_count_tokens(filename);
837 path = strdup(filename);
841 token_list = malloc(token_count * sizeof(char *));
847 /* Fill tokens list */
848 ret = sqfs_tokenize(token_list, token_count, path);
852 * ldir's (extended directory) size is greater than dir, so it works as
853 * a general solution for the malloc size, since 'i' is a union.
855 dirs->inode_table = inode_table;
856 dirs->dir_table = dir_table;
857 ret = sqfs_search_dir(dirs, token_list, token_count, pos_list,
862 if (le16_to_cpu(dirs->i_dir.inode_type) == SQFS_DIR_TYPE)
863 dirs->size = le16_to_cpu(dirs->i_dir.file_size);
865 dirs->size = le32_to_cpu(dirs->i_ldir.file_size);
867 /* Setup directory header */
868 memcpy(dirs->dir_header, dirs->table, SQFS_DIR_HEADER_SIZE);
869 dirs->entry_count = dirs->dir_header->count + 1;
870 dirs->size -= SQFS_DIR_HEADER_SIZE;
874 dirs->table += SQFS_DIR_HEADER_SIZE;
876 *dirsp = (struct fs_dir_stream *)dirs;
879 for (j = 0; j < token_count; j++)
889 int sqfs_readdir(struct fs_dir_stream *fs_dirs, struct fs_dirent **dentp)
891 struct squashfs_super_block *sblk = ctxt.sblk;
892 struct squashfs_dir_stream *dirs;
893 struct squashfs_lreg_inode *lreg;
894 struct squashfs_base_inode *base;
895 struct squashfs_reg_inode *reg;
896 int i_number, offset = 0, ret;
897 struct fs_dirent *dent;
900 dirs = (struct squashfs_dir_stream *)fs_dirs;
903 return -SQFS_STOP_READDIR;
908 if (!dirs->entry_count) {
909 if (dirs->size > SQFS_DIR_HEADER_SIZE) {
910 dirs->size -= SQFS_DIR_HEADER_SIZE;
914 return -SQFS_STOP_READDIR;
917 if (dirs->size > SQFS_EMPTY_FILE_SIZE) {
918 /* Read follow-up (emitted) dir. header */
919 memcpy(dirs->dir_header, dirs->table,
920 SQFS_DIR_HEADER_SIZE);
921 dirs->entry_count = dirs->dir_header->count + 1;
922 ret = sqfs_read_entry(&dirs->entry, dirs->table +
923 SQFS_DIR_HEADER_SIZE);
925 return -SQFS_STOP_READDIR;
927 dirs->table += SQFS_DIR_HEADER_SIZE;
930 ret = sqfs_read_entry(&dirs->entry, dirs->table);
932 return -SQFS_STOP_READDIR;
935 i_number = dirs->dir_header->inode_number + dirs->entry->inode_offset;
936 ipos = sqfs_find_inode(dirs->inode_table, i_number, sblk->inodes,
939 base = (struct squashfs_base_inode *)ipos;
941 /* Set entry type and size */
942 switch (dirs->entry->type) {
945 dent->type = FS_DT_DIR;
950 * Entries do not differentiate extended from regular types, so
951 * it needs to be verified manually.
953 if (get_unaligned_le16(&base->inode_type) == SQFS_LREG_TYPE) {
954 lreg = (struct squashfs_lreg_inode *)ipos;
955 dent->size = get_unaligned_le64(&lreg->file_size);
957 reg = (struct squashfs_reg_inode *)ipos;
958 dent->size = get_unaligned_le32(®->file_size);
961 dent->type = FS_DT_REG;
963 case SQFS_BLKDEV_TYPE:
964 case SQFS_CHRDEV_TYPE:
965 case SQFS_LBLKDEV_TYPE:
966 case SQFS_LCHRDEV_TYPE:
968 case SQFS_SOCKET_TYPE:
969 case SQFS_LFIFO_TYPE:
970 case SQFS_LSOCKET_TYPE:
971 dent->type = SQFS_MISC_ENTRY_TYPE;
973 case SQFS_SYMLINK_TYPE:
974 case SQFS_LSYMLINK_TYPE:
975 dent->type = FS_DT_LNK;
978 return -SQFS_STOP_READDIR;
982 strncpy(dent->name, dirs->entry->name, dirs->entry->name_size + 1);
983 dent->name[dirs->entry->name_size + 1] = '\0';
985 offset = dirs->entry->name_size + 1 + SQFS_ENTRY_BASE_LENGTH;
988 /* Decrement size to be read */
989 if (dirs->size > offset)
990 dirs->size -= offset;
994 /* Keep a reference to the current entry before incrementing it */
995 dirs->table += offset;
1002 int sqfs_probe(struct blk_desc *fs_dev_desc, struct disk_partition *fs_partition)
1004 struct squashfs_super_block *sblk;
1007 ctxt.cur_dev = fs_dev_desc;
1008 ctxt.cur_part_info = *fs_partition;
1010 ret = sqfs_read_sblk(&sblk);
1014 /* Make sure it has a valid SquashFS magic number*/
1015 if (get_unaligned_le32(&sblk->s_magic) != SQFS_MAGIC_NUMBER) {
1016 printf("Bad magic number for SquashFS image.\n");
1017 ctxt.cur_dev = NULL;
1023 ret = sqfs_decompressor_init(&ctxt);
1026 ctxt.cur_dev = NULL;
1034 static char *sqfs_basename(char *path)
1038 fname = path + strlen(path) - 1;
1039 while (fname >= path) {
1040 if (*fname == '/') {
1051 static char *sqfs_dirname(char *path)
1055 fname = sqfs_basename(path);
1063 * Takes a path to file and splits it in two parts: the filename itself and the
1064 * directory's path, e.g.:
1065 * path: /path/to/file.txt
1069 static int sqfs_split_path(char **file, char **dir, const char *path)
1071 char *dirc, *basec, *bname, *dname, *tmp_path;
1074 /* check for first slash in path*/
1075 if (path[0] == '/') {
1076 tmp_path = strdup(path);
1080 tmp_path = malloc(strlen(path) + 2);
1084 strcpy(tmp_path + 1, path);
1087 /* String duplicates */
1088 dirc = strdup(tmp_path);
1094 basec = strdup(tmp_path);
1100 dname = sqfs_dirname(dirc);
1101 bname = sqfs_basename(basec);
1103 *file = strdup(bname);
1110 if (*dname == '\0') {
1120 *dir = strdup(dname);
1137 static int sqfs_get_regfile_info(struct squashfs_reg_inode *reg,
1138 struct squashfs_file_info *finfo,
1139 struct squashfs_fragment_block_entry *fentry,
1142 int datablk_count = 0, ret;
1144 finfo->size = get_unaligned_le32(®->file_size);
1145 finfo->offset = get_unaligned_le32(®->offset);
1146 finfo->start = get_unaligned_le32(®->start_block);
1147 finfo->frag = SQFS_IS_FRAGMENTED(get_unaligned_le32(®->fragment));
1149 if (finfo->frag && finfo->offset == 0xFFFFFFFF)
1152 if (finfo->size < 1 || finfo->start == 0xFFFFFFFF)
1156 datablk_count = finfo->size / le32_to_cpu(blksz);
1157 ret = sqfs_frag_lookup(get_unaligned_le32(®->fragment),
1162 if (fentry->size < 1 || fentry->start == 0x7FFFFFFF)
1165 datablk_count = DIV_ROUND_UP(finfo->size, le32_to_cpu(blksz));
1168 finfo->blk_sizes = malloc(datablk_count * sizeof(u32));
1169 if (!finfo->blk_sizes)
1172 return datablk_count;
1175 static int sqfs_get_lregfile_info(struct squashfs_lreg_inode *lreg,
1176 struct squashfs_file_info *finfo,
1177 struct squashfs_fragment_block_entry *fentry,
1180 int datablk_count = 0, ret;
1182 finfo->size = get_unaligned_le64(&lreg->file_size);
1183 finfo->offset = get_unaligned_le32(&lreg->offset);
1184 finfo->start = get_unaligned_le64(&lreg->start_block);
1185 finfo->frag = SQFS_IS_FRAGMENTED(get_unaligned_le32(&lreg->fragment));
1187 if (finfo->frag && finfo->offset == 0xFFFFFFFF)
1190 if (finfo->size < 1 || finfo->start == 0x7FFFFFFF)
1194 datablk_count = finfo->size / le32_to_cpu(blksz);
1195 ret = sqfs_frag_lookup(get_unaligned_le32(&lreg->fragment),
1200 if (fentry->size < 1 || fentry->start == 0x7FFFFFFF)
1203 datablk_count = DIV_ROUND_UP(finfo->size, le32_to_cpu(blksz));
1206 finfo->blk_sizes = malloc(datablk_count * sizeof(u32));
1207 if (!finfo->blk_sizes)
1210 return datablk_count;
1213 int sqfs_read(const char *filename, void *buf, loff_t offset, loff_t len,
1216 char *dir, *fragment_block, *datablock = NULL, *data_buffer = NULL;
1217 char *fragment, *file, *resolved, *data;
1218 u64 start, n_blks, table_size, data_offset, table_offset;
1219 int ret, j, i_number, datablk_count = 0;
1220 struct squashfs_super_block *sblk = ctxt.sblk;
1221 struct squashfs_fragment_block_entry frag_entry;
1222 struct squashfs_file_info finfo = {0};
1223 struct squashfs_symlink_inode *symlink;
1224 struct fs_dir_stream *dirsp = NULL;
1225 struct squashfs_dir_stream *dirs;
1226 struct squashfs_lreg_inode *lreg;
1227 struct squashfs_base_inode *base;
1228 struct squashfs_reg_inode *reg;
1229 unsigned long dest_len;
1230 struct fs_dirent *dent;
1231 unsigned char *ipos;
1236 * sqfs_opendir will uncompress inode and directory tables, and will
1237 * return a pointer to the directory that contains the requested file.
1239 sqfs_split_path(&file, &dir, filename);
1240 ret = sqfs_opendir(dir, &dirsp);
1242 sqfs_closedir(dirsp);
1246 dirs = (struct squashfs_dir_stream *)dirsp;
1248 /* For now, only regular files are able to be loaded */
1249 while (!sqfs_readdir(dirsp, &dent)) {
1250 ret = strcmp(dent->name, file);
1258 printf("File not found.\n");
1260 sqfs_closedir(dirsp);
1265 i_number = dirs->dir_header->inode_number + dirs->entry->inode_offset;
1266 ipos = sqfs_find_inode(dirs->inode_table, i_number, sblk->inodes,
1269 base = (struct squashfs_base_inode *)ipos;
1270 switch (get_unaligned_le16(&base->inode_type)) {
1272 reg = (struct squashfs_reg_inode *)ipos;
1273 datablk_count = sqfs_get_regfile_info(reg, &finfo, &frag_entry,
1275 if (datablk_count < 0) {
1280 memcpy(finfo.blk_sizes, ipos + sizeof(*reg),
1281 datablk_count * sizeof(u32));
1283 case SQFS_LREG_TYPE:
1284 lreg = (struct squashfs_lreg_inode *)ipos;
1285 datablk_count = sqfs_get_lregfile_info(lreg, &finfo,
1288 if (datablk_count < 0) {
1293 memcpy(finfo.blk_sizes, ipos + sizeof(*lreg),
1294 datablk_count * sizeof(u32));
1296 case SQFS_SYMLINK_TYPE:
1297 case SQFS_LSYMLINK_TYPE:
1298 symlink = (struct squashfs_symlink_inode *)ipos;
1299 resolved = sqfs_resolve_symlink(symlink, filename);
1300 ret = sqfs_read(resolved, buf, offset, len, actread);
1303 case SQFS_BLKDEV_TYPE:
1304 case SQFS_CHRDEV_TYPE:
1305 case SQFS_LBLKDEV_TYPE:
1306 case SQFS_LCHRDEV_TYPE:
1307 case SQFS_FIFO_TYPE:
1308 case SQFS_SOCKET_TYPE:
1309 case SQFS_LFIFO_TYPE:
1310 case SQFS_LSOCKET_TYPE:
1312 printf("Unsupported entry type\n");
1317 /* If the user specifies a length, check its sanity */
1319 if (len > finfo.size) {
1327 if (datablk_count) {
1328 data_offset = finfo.start;
1329 datablock = malloc(get_unaligned_le32(&sblk->block_size));
1336 for (j = 0; j < datablk_count; j++) {
1337 start = data_offset / ctxt.cur_dev->blksz;
1338 table_size = SQFS_BLOCK_SIZE(finfo.blk_sizes[j]);
1339 table_offset = data_offset - (start * ctxt.cur_dev->blksz);
1340 n_blks = DIV_ROUND_UP(table_size + table_offset,
1341 ctxt.cur_dev->blksz);
1343 data_buffer = malloc_cache_aligned(n_blks * ctxt.cur_dev->blksz);
1350 ret = sqfs_disk_read(start, n_blks, data_buffer);
1353 * Possible causes: too many data blocks or too large
1354 * SquashFS block size. Tip: re-compile the SquashFS
1355 * image with mksquashfs's -b <block_size> option.
1357 printf("Error: too many data blocks to be read.\n");
1361 data = data_buffer + table_offset;
1364 if (SQFS_COMPRESSED_BLOCK(finfo.blk_sizes[j])) {
1365 dest_len = get_unaligned_le32(&sblk->block_size);
1366 ret = sqfs_decompress(&ctxt, datablock, &dest_len,
1371 memcpy(buf + offset + *actread, datablock, dest_len);
1372 *actread += dest_len;
1374 memcpy(buf + offset + *actread, data, table_size);
1375 *actread += table_size;
1378 data_offset += table_size;
1381 free(finfo.blk_sizes);
1384 * There is no need to continue if the file is not fragmented.
1391 start = frag_entry.start / ctxt.cur_dev->blksz;
1392 table_size = SQFS_BLOCK_SIZE(frag_entry.size);
1393 table_offset = frag_entry.start - (start * ctxt.cur_dev->blksz);
1394 n_blks = DIV_ROUND_UP(table_size + table_offset, ctxt.cur_dev->blksz);
1396 fragment = malloc_cache_aligned(n_blks * ctxt.cur_dev->blksz);
1403 ret = sqfs_disk_read(start, n_blks, fragment);
1407 /* File compressed and fragmented */
1408 if (finfo.frag && finfo.comp) {
1409 dest_len = get_unaligned_le32(&sblk->block_size);
1410 fragment_block = malloc(dest_len);
1411 if (!fragment_block) {
1416 ret = sqfs_decompress(&ctxt, fragment_block, &dest_len,
1417 (void *)fragment + table_offset,
1420 free(fragment_block);
1424 for (j = offset + *actread; j < finfo.size; j++) {
1425 memcpy(buf + j, &fragment_block[finfo.offset + j], 1);
1429 free(fragment_block);
1431 } else if (finfo.frag && !finfo.comp) {
1432 fragment_block = (void *)fragment + table_offset;
1434 for (j = offset + *actread; j < finfo.size; j++) {
1435 memcpy(buf + j, &fragment_block[finfo.offset + j], 1);
1455 int sqfs_size(const char *filename, loff_t *size)
1457 struct squashfs_super_block *sblk = ctxt.sblk;
1458 struct squashfs_symlink_inode *symlink;
1459 struct fs_dir_stream *dirsp = NULL;
1460 struct squashfs_base_inode *base;
1461 struct squashfs_dir_stream *dirs;
1462 struct squashfs_lreg_inode *lreg;
1463 struct squashfs_reg_inode *reg;
1464 char *dir, *file, *resolved;
1465 struct fs_dirent *dent;
1466 unsigned char *ipos;
1469 sqfs_split_path(&file, &dir, filename);
1471 * sqfs_opendir will uncompress inode and directory tables, and will
1472 * return a pointer to the directory that contains the requested file.
1474 ret = sqfs_opendir(dir, &dirsp);
1476 sqfs_closedir(dirsp);
1481 dirs = (struct squashfs_dir_stream *)dirsp;
1483 while (!sqfs_readdir(dirsp, &dent)) {
1484 ret = strcmp(dent->name, file);
1491 printf("File not found.\n");
1497 i_number = dirs->dir_header->inode_number + dirs->entry->inode_offset;
1498 ipos = sqfs_find_inode(dirs->inode_table, i_number, sblk->inodes,
1502 base = (struct squashfs_base_inode *)ipos;
1503 switch (get_unaligned_le16(&base->inode_type)) {
1505 reg = (struct squashfs_reg_inode *)ipos;
1506 *size = get_unaligned_le32(®->file_size);
1508 case SQFS_LREG_TYPE:
1509 lreg = (struct squashfs_lreg_inode *)ipos;
1510 *size = get_unaligned_le64(&lreg->file_size);
1512 case SQFS_SYMLINK_TYPE:
1513 case SQFS_LSYMLINK_TYPE:
1514 symlink = (struct squashfs_symlink_inode *)ipos;
1515 resolved = sqfs_resolve_symlink(symlink, filename);
1516 ret = sqfs_size(resolved, size);
1519 case SQFS_BLKDEV_TYPE:
1520 case SQFS_CHRDEV_TYPE:
1521 case SQFS_LBLKDEV_TYPE:
1522 case SQFS_LCHRDEV_TYPE:
1523 case SQFS_FIFO_TYPE:
1524 case SQFS_SOCKET_TYPE:
1525 case SQFS_LFIFO_TYPE:
1526 case SQFS_LSOCKET_TYPE:
1528 printf("Unable to recover entry's size.\n");
1538 sqfs_closedir(dirsp);
1543 void sqfs_close(void)
1546 ctxt.cur_dev = NULL;
1547 sqfs_decompressor_cleanup(&ctxt);
1550 void sqfs_closedir(struct fs_dir_stream *dirs)
1552 struct squashfs_dir_stream *sqfs_dirs;
1554 sqfs_dirs = (struct squashfs_dir_stream *)dirs;
1555 free(sqfs_dirs->inode_table);
1556 free(sqfs_dirs->dir_table);
1557 free(sqfs_dirs->dir_header);