feature.c revision 477007e1b1f8880f8974729167fcfca8076dbd6c 
1/*
2 * feature.c --- convert between features and strings
3 *
4 * Copyright (C) 1999  Theodore Ts'o <tytso@mit.edu>
5 *
6 * This file can be redistributed under the terms of the GNU Library General
7 * Public License
8 *
9 */
10
11#include <stdio.h>
12#include <stdlib.h>
13#include <string.h>
14#include <ctype.h>
15#include <errno.h>
16
17#include "e2p.h"
18
19struct feature {
20	int		compat;
21	unsigned int	mask;
22	const char	*string;
23};
24
25static struct feature feature_list[] = {
26	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_DIR_PREALLOC,
27			"dir_prealloc" },
28	{	E2P_FEATURE_COMPAT, EXT3_FEATURE_COMPAT_HAS_JOURNAL,
29			"has_journal" },
30	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_IMAGIC_INODES,
31			"imagic_inodes" },
32	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_EXT_ATTR,
33			"ext_attr" },
34	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_DIR_INDEX,
35			"dir_index" },
36	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_RESIZE_INODE,
37			"resize_inode" },
38	{	E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_LAZY_BG,
39			"lazy_bg" },
40
41	{	E2P_FEATURE_RO_INCOMPAT, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER,
42			"sparse_super" },
43	{	E2P_FEATURE_RO_INCOMPAT, EXT2_FEATURE_RO_COMPAT_LARGE_FILE,
44			"large_file" },
45	{	E2P_FEATURE_RO_INCOMPAT, EXT4_FEATURE_RO_COMPAT_HUGE_FILE,
46			"huge_file" },
47	{	E2P_FEATURE_RO_INCOMPAT, EXT4_FEATURE_RO_COMPAT_GDT_CSUM,
48			"gdt_checksum" },
49	{	E2P_FEATURE_RO_INCOMPAT, EXT4_FEATURE_RO_COMPAT_DIR_NLINK,
50			"dir_nlink" },
51	{	E2P_FEATURE_RO_INCOMPAT, EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE,
52			"extra_isize" },
53
54	{	E2P_FEATURE_INCOMPAT, EXT2_FEATURE_INCOMPAT_COMPRESSION,
55			"compression" },
56	{	E2P_FEATURE_INCOMPAT, EXT2_FEATURE_INCOMPAT_FILETYPE,
57			"filetype" },
58	{	E2P_FEATURE_INCOMPAT, EXT3_FEATURE_INCOMPAT_RECOVER,
59			"needs_recovery" },
60	{	E2P_FEATURE_INCOMPAT, EXT3_FEATURE_INCOMPAT_JOURNAL_DEV,
61			"journal_dev" },
62	{	E2P_FEATURE_INCOMPAT, EXT3_FEATURE_INCOMPAT_EXTENTS,
63			"extents" },
64	{	E2P_FEATURE_INCOMPAT, EXT2_FEATURE_INCOMPAT_META_BG,
65			"meta_bg" },
66	{	E2P_FEATURE_INCOMPAT, EXT3_FEATURE_INCOMPAT_EXTENTS,
67			"extent" },
68	{	E2P_FEATURE_INCOMPAT, EXT4_FEATURE_INCOMPAT_64BIT,
69			"64bit" },
70	{	0, 0, 0 },
71};
72
73const char *e2p_feature2string(int compat, unsigned int mask)
74{
75	struct feature  *f;
76	static char buf[20];
77	char	fchar;
78	int	fnum;
79
80	for (f = feature_list; f->string; f++) {
81		if ((compat == f->compat) &&
82		    (mask == f->mask))
83			return f->string;
84	}
85	switch (compat) {
86	case  E2P_FEATURE_COMPAT:
87		fchar = 'C';
88		break;
89	case E2P_FEATURE_INCOMPAT:
90		fchar = 'I';
91		break;
92	case E2P_FEATURE_RO_INCOMPAT:
93		fchar = 'R';
94		break;
95	default:
96		fchar = '?';
97		break;
98	}
99	for (fnum = 0; mask >>= 1; fnum++);
100	sprintf(buf, "FEATURE_%c%d", fchar, fnum);
101	return buf;
102}
103
104int e2p_string2feature(char *string, int *compat_type, unsigned int *mask)
105{
106	struct feature  *f;
107	char		*eptr;
108	int		num;
109
110	for (f = feature_list; f->string; f++) {
111		if (!strcasecmp(string, f->string)) {
112			*compat_type = f->compat;
113			*mask = f->mask;
114			return 0;
115		}
116	}
117	if (strncasecmp(string, "FEATURE_", 8))
118		return 1;
119
120	switch (string[8]) {
121	case 'c':
122	case 'C':
123		*compat_type = E2P_FEATURE_COMPAT;
124		break;
125	case 'i':
126	case 'I':
127		*compat_type = E2P_FEATURE_INCOMPAT;
128		break;
129	case 'r':
130	case 'R':
131		*compat_type = E2P_FEATURE_RO_INCOMPAT;
132		break;
133	default:
134		return 1;
135	}
136	if (string[9] == 0)
137		return 1;
138	num = strtol(string+9, &eptr, 10);
139	if (num > 32 || num < 0)
140		return 1;
141	if (*eptr)
142		return 1;
143	*mask = 1 << num;
144	return 0;
145}
146
147static char *skip_over_blanks(char *cp)
148{
149	while (*cp && isspace(*cp))
150		cp++;
151	return cp;
152}
153
154static char *skip_over_word(char *cp)
155{
156	while (*cp && !isspace(*cp) && *cp != ',')
157		cp++;
158	return cp;
159}
160
161/*
162 * Edit a feature set array as requested by the user.  The ok_array,
163 * if set, allows the application to limit what features the user is
164 * allowed to set or clear using this function.
165 */
166int e2p_edit_feature(const char *str, __u32 *compat_array, __u32 *ok_array)
167{
168	char	*cp, *buf, *next;
169	int	neg;
170	unsigned int	mask;
171	int		compat_type;
172
173	buf = malloc(strlen(str)+1);
174	if (!buf)
175		return 1;
176	strcpy(buf, str);
177	for (cp = buf; cp && *cp; cp = next ? next+1 : 0) {
178		neg = 0;
179		cp = skip_over_blanks(cp);
180		next = skip_over_word(cp);
181
182		if (*next == 0)
183			next = 0;
184		else
185			*next = 0;
186
187		if ((strcasecmp(cp, "none") == 0) ||
188		    (strcasecmp(cp, "clear") == 0)) {
189			compat_array[0] = 0;
190			compat_array[1] = 0;
191			compat_array[2] = 0;
192			continue;
193		}
194
195		switch (*cp) {
196		case '-':
197		case '^':
198			neg++;
199		case '+':
200			cp++;
201			break;
202		}
203		if (e2p_string2feature(cp, &compat_type, &mask))
204			return 1;
205		if (ok_array && !(ok_array[compat_type] & mask))
206			return 1;
207		if (neg)
208			compat_array[compat_type] &= ~mask;
209		else
210			compat_array[compat_type] |= mask;
211	}
212	return 0;
213}
214
215