1 /*
2 * mountopts.c --- convert between default mount options and strings
3 *
4 * Copyright (C) 2002 Theodore Ts'o <tytso@mit.edu>
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Library
8 * General Public License, version 2.
9 * %End-Header%
10 */
11
12 #include "config.h"
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include <strings.h>
17 #include <ctype.h>
18 #include <errno.h>
19
20 #include "e2p.h"
21
22 struct mntopt {
23 unsigned int mask;
24 const char *string;
25 };
26
27 static struct mntopt mntopt_list[] = {
28 { EXT2_DEFM_DEBUG, "debug" },
29 { EXT2_DEFM_BSDGROUPS, "bsdgroups" },
30 { EXT2_DEFM_XATTR_USER, "user_xattr" },
31 { EXT2_DEFM_ACL, "acl" },
32 { EXT2_DEFM_UID16, "uid16" },
33 { EXT3_DEFM_JMODE_DATA, "journal_data" },
34 { EXT3_DEFM_JMODE_ORDERED, "journal_data_ordered" },
35 { EXT3_DEFM_JMODE_WBACK, "journal_data_writeback" },
36 { EXT4_DEFM_NOBARRIER, "nobarrier" },
37 { EXT4_DEFM_BLOCK_VALIDITY, "block_validity" },
38 { EXT4_DEFM_DISCARD, "discard"},
39 { EXT4_DEFM_NODELALLOC, "nodelalloc"},
40 { 0, 0 },
41 };
42
e2p_mntopt2string(unsigned int mask)43 const char *e2p_mntopt2string(unsigned int mask)
44 {
45 struct mntopt *f;
46 static char buf[20];
47 int fnum;
48
49 for (f = mntopt_list; f->string; f++) {
50 if (mask == f->mask)
51 return f->string;
52 }
53 for (fnum = 0; mask >>= 1; fnum++);
54 sprintf(buf, "MNTOPT_%d", fnum);
55 return buf;
56 }
57
e2p_string2mntopt(char * string,unsigned int * mask)58 int e2p_string2mntopt(char *string, unsigned int *mask)
59 {
60 struct mntopt *f;
61 char *eptr;
62 int num;
63
64 for (f = mntopt_list; f->string; f++) {
65 if (!strcasecmp(string, f->string)) {
66 *mask = f->mask;
67 return 0;
68 }
69 }
70 if (strncasecmp(string, "MNTOPT_", 7))
71 return 1;
72
73 if (string[8] == 0)
74 return 1;
75 num = strtol(string+8, &eptr, 10);
76 if (num > 31 || num < 0)
77 return 1;
78 if (*eptr)
79 return 1;
80 *mask = 1 << num;
81 return 0;
82 }
83
skip_over_blanks(char * cp)84 static char *skip_over_blanks(char *cp)
85 {
86 while (*cp && isspace(*cp))
87 cp++;
88 return cp;
89 }
90
skip_over_word(char * cp)91 static char *skip_over_word(char *cp)
92 {
93 while (*cp && !isspace(*cp) && *cp != ',')
94 cp++;
95 return cp;
96 }
97
98 /*
99 * Edit a mntopt set array as requested by the user. The ok
100 * parameter, if non-zero, allows the application to limit what
101 * mntopts the user is allowed to set or clear using this function.
102 */
e2p_edit_mntopts(const char * str,__u32 * mntopts,__u32 ok)103 int e2p_edit_mntopts(const char *str, __u32 *mntopts, __u32 ok)
104 {
105 char *cp, *buf, *next;
106 int neg;
107 unsigned int mask;
108 int rc = 0;
109
110 buf = malloc(strlen(str)+1);
111 if (!buf)
112 return 1;
113 strcpy(buf, str);
114 cp = buf;
115 while (cp && *cp) {
116 neg = 0;
117 cp = skip_over_blanks(cp);
118 next = skip_over_word(cp);
119 if (*next == 0)
120 next = 0;
121 else
122 *next = 0;
123 switch (*cp) {
124 case '-':
125 case '^':
126 neg++;
127 /* fallthrough */
128 case '+':
129 cp++;
130 break;
131 }
132 if (e2p_string2mntopt(cp, &mask)) {
133 rc = 1;
134 break;
135 }
136 if (ok && !(ok & mask)) {
137 rc = 1;
138 break;
139 }
140 if (mask & EXT3_DEFM_JMODE)
141 *mntopts &= ~EXT3_DEFM_JMODE;
142 if (neg)
143 *mntopts &= ~mask;
144 else
145 *mntopts |= mask;
146 cp = next ? next+1 : 0;
147 }
148 free(buf);
149 return rc;
150 }
151