summaryrefslogtreecommitdiff
path: root/fs/squashfs/sqfs_inode.c
blob: 1368f3063c5cd019577181270e283b57ddba9fc9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2020 Bootlin
 *
 * Author: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
 */

#include <asm/unaligned.h>
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "sqfs_decompressor.h"
#include "sqfs_filesystem.h"
#include "sqfs_utils.h"

int sqfs_inode_size(struct squashfs_base_inode *inode, u32 blk_size)
{
	switch (get_unaligned_le16(&inode->inode_type)) {
	case SQFS_DIR_TYPE:
		return sizeof(struct squashfs_dir_inode);

	case SQFS_REG_TYPE: {
		struct squashfs_reg_inode *reg =
			(struct squashfs_reg_inode *)inode;
		u32 fragment = get_unaligned_le32(&reg->fragment);
		u32 file_size = get_unaligned_le32(&reg->file_size);
		unsigned int blk_list_size;

		if (SQFS_IS_FRAGMENTED(fragment))
			blk_list_size = file_size / blk_size;
		else
			blk_list_size = DIV_ROUND_UP(file_size, blk_size);

		return sizeof(*reg) + blk_list_size * sizeof(u32);
	}

	case SQFS_LDIR_TYPE: {
		struct squashfs_ldir_inode *ldir =
			(struct squashfs_ldir_inode *)inode;
		u16 i_count = get_unaligned_le16(&ldir->i_count);
		unsigned int index_list_size = 0, l = 0;
		struct squashfs_directory_index *di;
		u32 sz;

		if (i_count == 0)
			return sizeof(*ldir);

		di = ldir->index;
		while (l < i_count + 1) {
			sz = get_unaligned_le32(&di->size) + 1;
			index_list_size += sz;
			di = (void *)di + sizeof(*di) + sz;
			l++;
		}

		return sizeof(*ldir) + index_list_size +
			(i_count + 1) * SQFS_DIR_INDEX_BASE_LENGTH;
	}

	case SQFS_LREG_TYPE: {
		struct squashfs_lreg_inode *lreg =
			(struct squashfs_lreg_inode *)inode;
		u32 fragment = get_unaligned_le32(&lreg->fragment);
		u64 file_size = get_unaligned_le64(&lreg->file_size);
		unsigned int blk_list_size;

		if (fragment == 0xFFFFFFFF)
			blk_list_size = DIV_ROUND_UP(file_size, blk_size);
		else
			blk_list_size = file_size / blk_size;

		return sizeof(*lreg) + blk_list_size * sizeof(u32);
	}

	case SQFS_SYMLINK_TYPE:
	case SQFS_LSYMLINK_TYPE: {
		struct squashfs_symlink_inode *symlink =
			(struct squashfs_symlink_inode *)inode;

		return sizeof(*symlink) +
			get_unaligned_le32(&symlink->symlink_size);
	}

	case SQFS_BLKDEV_TYPE:
	case SQFS_CHRDEV_TYPE:
		return sizeof(struct squashfs_dev_inode);
	case SQFS_LBLKDEV_TYPE:
	case SQFS_LCHRDEV_TYPE:
		return sizeof(struct squashfs_ldev_inode);
	case SQFS_FIFO_TYPE:
	case SQFS_SOCKET_TYPE:
		return sizeof(struct squashfs_ipc_inode);
	case SQFS_LFIFO_TYPE:
	case SQFS_LSOCKET_TYPE:
		return sizeof(struct squashfs_lipc_inode);
	default:
		printf("Error while searching inode: unknown type.\n");
		return -EINVAL;
	}
}

/*
 * Given the uncompressed inode table, the inode to be found and the number of
 * inodes in the table, return inode position in case of success.
 */
void *sqfs_find_inode(void *inode_table, int inode_number, __le32 inode_count,
		      __le32 block_size)
{
	struct squashfs_base_inode *base;
	unsigned int offset = 0, k;
	int sz;

	if (!inode_table) {
		printf("%s: Invalid pointer to inode table.\n", __func__);
		return NULL;
	}

	for (k = 0; k < le32_to_cpu(inode_count); k++) {
		base = inode_table + offset;
		if (get_unaligned_le32(&base->inode_number) == inode_number)
			return inode_table + offset;

		sz = sqfs_inode_size(base, le32_to_cpu(block_size));
		if (sz < 0)
			return NULL;

		offset += sz;
	}

	printf("Inode not found.\n");

	return NULL;
}

int sqfs_read_metablock(unsigned char *file_mapping, int offset,
			bool *compressed, u32 *data_size)
{
	const unsigned char *data;
	u16 header;

	data = file_mapping + offset;
	if (!data)
		return -EFAULT;

	header = get_unaligned((u16 *)data);
	if (!header)
		return -EINVAL;

	*compressed = SQFS_COMPRESSED_METADATA(header);
	*data_size = SQFS_METADATA_SIZE(header);

	if (*data_size > SQFS_METADATA_BLOCK_SIZE) {
		printf("Invalid metatada block size: %d bytes.\n", *data_size);
		return -EINVAL;
	}

	return 0;
}