summaryrefslogtreecommitdiffhomepage
path: root/e2fsprogs/e2p/feature.c
blob: 602c2ff027b4f5047ac9bfa5e99dd92e3c2f730a (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
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
/* vi: set sw=4 ts=4: */
/*
 * feature.c --- convert between features and strings
 *
 * Copyright (C) 1999  Theodore Ts'o <tytso@mit.edu>
 *
 * This file can be redistributed under the terms of the GNU Library General
 * Public License
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>

#include "e2p.h"

struct feature {
	int		compat;
	unsigned int	mask;
	const char	*string;
};

static const struct feature feature_list[] = {
	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_DIR_PREALLOC,
			"dir_prealloc" },
	{	E2P_FEATURE_COMPAT, EXT3_FEATURE_COMPAT_HAS_JOURNAL,
			"has_journal" },
	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_IMAGIC_INODES,
			"imagic_inodes" },
	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_EXT_ATTR,
			"ext_attr" },
	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_DIR_INDEX,
			"dir_index" },
	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_RESIZE_INODE,
			"resize_inode" },
	{	E2P_FEATURE_RO_INCOMPAT, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER,
			"sparse_super" },
	{	E2P_FEATURE_RO_INCOMPAT, EXT2_FEATURE_RO_COMPAT_LARGE_FILE,
			"large_file" },
	{	E2P_FEATURE_INCOMPAT, EXT2_FEATURE_INCOMPAT_COMPRESSION,
			"compression" },
	{	E2P_FEATURE_INCOMPAT, EXT2_FEATURE_INCOMPAT_FILETYPE,
			"filetype" },
	{	E2P_FEATURE_INCOMPAT, EXT3_FEATURE_INCOMPAT_RECOVER,
			"needs_recovery" },
	{	E2P_FEATURE_INCOMPAT, EXT3_FEATURE_INCOMPAT_JOURNAL_DEV,
			"journal_dev" },
	{	E2P_FEATURE_INCOMPAT, EXT3_FEATURE_INCOMPAT_EXTENTS,
			"extents" },
	{	E2P_FEATURE_INCOMPAT, EXT2_FEATURE_INCOMPAT_META_BG,
			"meta_bg" },
	{	0, 0, 0 },
};

const char *e2p_feature2string(int compat, unsigned int mask)
{
	const struct feature *f;
	static char buf[20];
	char fchar;
	int fnum;

	for (f = feature_list; f->string; f++) {
		if ((compat == f->compat) &&
		    (mask == f->mask))
			return f->string;
	}
	switch (compat) {
	case E2P_FEATURE_COMPAT:
		fchar = 'C';
		break;
	case E2P_FEATURE_INCOMPAT:
		fchar = 'I';
		break;
	case E2P_FEATURE_RO_INCOMPAT:
		fchar = 'R';
		break;
	default:
		fchar = '?';
		break;
	}
	for (fnum = 0; mask >>= 1; fnum++);
		sprintf(buf, "FEATURE_%c%d", fchar, fnum);
	return buf;
}

int e2p_string2feature(char *string, int *compat_type, unsigned int *mask)
{
	const struct feature *f;
	char *eptr;
	int num;

	for (f = feature_list; f->string; f++) {
		if (!strcasecmp(string, f->string)) {
			*compat_type = f->compat;
			*mask = f->mask;
			return 0;
		}
	}
	if (strncasecmp(string, "FEATURE_", 8))
		return 1;

	switch (string[8]) {
	case 'c':
	case 'C':
		*compat_type = E2P_FEATURE_COMPAT;
		break;
	case 'i':
	case 'I':
		*compat_type = E2P_FEATURE_INCOMPAT;
		break;
	case 'r':
	case 'R':
		*compat_type = E2P_FEATURE_RO_INCOMPAT;
		break;
	default:
		return 1;
	}
	if (string[9] == 0)
		return 1;
	num = strtol(string+9, &eptr, 10);
	if (num > 32 || num < 0)
		return 1;
	if (*eptr)
		return 1;
	*mask = 1 << num;
	return 0;
}

static inline char *skip_over_blanks(char *cp)
{
	while (*cp && isspace(*cp))
		cp++;
	return cp;
}

static inline char *skip_over_word(char *cp)
{
	while (*cp && !isspace(*cp) && *cp != ',')
		cp++;
	return cp;
}

/*
 * Edit a feature set array as requested by the user.  The ok_array,
 * if set, allows the application to limit what features the user is
 * allowed to set or clear using this function.
 */
int e2p_edit_feature(const char *str, __u32 *compat_array, __u32 *ok_array)
{
	char	*cp, *buf, *next;
	int	neg;
	unsigned int	mask;
	int		compat_type;

	buf = bb_xstrdup(str);
	cp = buf;
	while (cp && *cp) {
		neg = 0;
		cp = skip_over_blanks(cp);
		next = skip_over_word(cp);
		if (*next == 0)
			next = 0;
		else
			*next = 0;
		switch (*cp) {
		case '-':
		case '^':
			neg++;
		case '+':
			cp++;
			break;
		}
		if (e2p_string2feature(cp, &compat_type, &mask))
			return 1;
		if (ok_array && !(ok_array[compat_type] & mask))
			return 1;
		if (neg)
			compat_array[compat_type] &= ~mask;
		else
			compat_array[compat_type] |= mask;
		cp = next ? next+1 : 0;
	}
	return 0;
}