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