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