aboutsummaryrefslogtreecommitdiff
path: root/lib/sqfs/id_table.c
blob: 55477dc5cc9518346f551dc2401d6795d08e80e9 (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
/* SPDX-License-Identifier: LGPL-3.0-or-later */
/*
 * id_table.c
 *
 * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
 */
#define SQFS_BUILDING_DLL
#include "config.h"

#include "sqfs/id_table.h"
#include "sqfs/super.h"
#include "sqfs/table.h"
#include "sqfs/error.h"

#include <stdlib.h>
#include <string.h>

struct sqfs_id_table_t {
	uint32_t *ids;
	size_t num_ids;
	size_t max_ids;
};

sqfs_id_table_t *sqfs_id_table_create(void)
{
	return calloc(1, sizeof(sqfs_id_table_t));
}

void sqfs_id_table_destroy(sqfs_id_table_t *tbl)
{
	free(tbl->ids);
	free(tbl);
}

int sqfs_id_table_id_to_index(sqfs_id_table_t *tbl, uint32_t id, uint16_t *out)
{
	size_t i, sz;
	void *ptr;

	for (i = 0; i < tbl->num_ids; ++i) {
		if (tbl->ids[i] == id) {
			*out = i;
			return 0;
		}
	}

	if (tbl->num_ids == 0x10000)
		return SQFS_ERROR_OVERFLOW;

	if (tbl->num_ids == tbl->max_ids) {
		sz = (tbl->max_ids ? tbl->max_ids * 2 : 16);
		ptr = realloc(tbl->ids, sizeof(tbl->ids[0]) * sz);

		if (ptr == NULL)
			return SQFS_ERROR_ALLOC;

		tbl->ids = ptr;
		tbl->max_ids = sz;
	}

	*out = tbl->num_ids;
	tbl->ids[tbl->num_ids++] = id;
	return 0;
}

int sqfs_id_table_index_to_id(const sqfs_id_table_t *tbl, uint16_t index,
			      uint32_t *out)
{
	if (index >= tbl->num_ids)
		return SQFS_ERROR_OUT_OF_BOUNDS;

	*out = tbl->ids[index];
	return 0;
}

int sqfs_id_table_read(sqfs_id_table_t *tbl, sqfs_file_t *file,
		       sqfs_super_t *super, sqfs_compressor_t *cmp)
{
	uint64_t upper_limit, lower_limit;
	void *raw_ids;
	size_t i;
	int ret;

	if (tbl->ids != NULL) {
		free(tbl->ids);
		tbl->num_ids = 0;
		tbl->max_ids = 0;
		tbl->ids = NULL;
	}

	if (!super->id_count || super->id_table_start >= super->bytes_used)
		return SQFS_ERROR_CORRUPTED;

	upper_limit = super->id_table_start;
	lower_limit = super->directory_table_start;

	if (super->fragment_table_start > lower_limit &&
	    super->fragment_table_start < upper_limit) {
		lower_limit = super->fragment_table_start;
	}

	if (super->export_table_start > lower_limit &&
	    super->export_table_start < upper_limit) {
		lower_limit = super->export_table_start;
	}

	tbl->num_ids = super->id_count;
	tbl->max_ids = super->id_count;
	ret = sqfs_read_table(file, cmp, tbl->num_ids * sizeof(uint32_t),
			      super->id_table_start, lower_limit,
			      upper_limit, &raw_ids);
	if (ret)
		return ret;

	tbl->ids = raw_ids;

	for (i = 0; i < tbl->num_ids; ++i)
		tbl->ids[i] = le32toh(tbl->ids[i]);

	return 0;
}

int sqfs_id_table_write(sqfs_id_table_t *tbl, sqfs_file_t *file,
			sqfs_super_t *super, sqfs_compressor_t *cmp)
{
	uint64_t start;
	size_t i;
	int ret;

	for (i = 0; i < tbl->num_ids; ++i)
		tbl->ids[i] = htole32(tbl->ids[i]);

	super->id_count = tbl->num_ids;

	ret = sqfs_write_table(file, cmp, tbl->ids,
			       sizeof(tbl->ids[0]) * tbl->num_ids, &start);

	super->id_table_start = start;

	for (i = 0; i < tbl->num_ids; ++i)
		tbl->ids[i] = le32toh(tbl->ids[i]);

	return ret;
}