xref: /linux/fs/hfsplus/options.c (revision 4bedea94545165364618d403d03b61d797acba0b)
1 /*
2  *  linux/fs/hfsplus/options.c
3  *
4  * Copyright (C) 2001
5  * Brad Boyer (flar@allandria.com)
6  * (C) 2003 Ardis Technologies <roman@ardistech.com>
7  *
8  * Option parsing
9  */
10 
11 #include <linux/string.h>
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/parser.h>
15 #include <linux/nls.h>
16 #include "hfsplus_fs.h"
17 
18 enum {
19 	opt_creator, opt_type,
20 	opt_umask, opt_uid, opt_gid,
21 	opt_part, opt_session, opt_nls,
22 	opt_nodecompose, opt_decompose,
23 	opt_err
24 };
25 
26 static match_table_t tokens = {
27 	{ opt_creator, "creator=%s" },
28 	{ opt_type, "type=%s" },
29 	{ opt_umask, "umask=%o" },
30 	{ opt_uid, "uid=%u" },
31 	{ opt_gid, "gid=%u" },
32 	{ opt_part, "part=%u" },
33 	{ opt_session, "session=%u" },
34 	{ opt_nls, "nls=%s" },
35 	{ opt_decompose, "decompose" },
36 	{ opt_nodecompose, "nodecompose" },
37 	{ opt_err, NULL }
38 };
39 
40 /* Initialize an options object to reasonable defaults */
41 void fill_defaults(struct hfsplus_sb_info *opts)
42 {
43 	if (!opts)
44 		return;
45 
46 	opts->creator = HFSPLUS_DEF_CR_TYPE;
47 	opts->type = HFSPLUS_DEF_CR_TYPE;
48 	opts->umask = current->fs->umask;
49 	opts->uid = current->uid;
50 	opts->gid = current->gid;
51 	opts->part = -1;
52 	opts->session = -1;
53 }
54 
55 /* convert a "four byte character" to a 32 bit int with error checks */
56 static inline int match_fourchar(substring_t *arg, u32 *result)
57 {
58 	if (arg->to - arg->from != 4)
59 		return -EINVAL;
60 	memcpy(result, arg->from, 4);
61 	return 0;
62 }
63 
64 /* Parse options from mount. Returns 0 on failure */
65 /* input is the options passed to mount() as a string */
66 int parse_options(char *input, struct hfsplus_sb_info *sbi)
67 {
68 	char *p;
69 	substring_t args[MAX_OPT_ARGS];
70 	int tmp, token;
71 
72 	if (!input)
73 		goto done;
74 
75 	while ((p = strsep(&input, ",")) != NULL) {
76 		if (!*p)
77 			continue;
78 
79 		token = match_token(p, tokens, args);
80 		switch (token) {
81 		case opt_creator:
82 			if (match_fourchar(&args[0], &sbi->creator)) {
83 				printk("HFS+-fs: creator requires a 4 character value\n");
84 				return 0;
85 			}
86 			break;
87 		case opt_type:
88 			if (match_fourchar(&args[0], &sbi->type)) {
89 				printk("HFS+-fs: type requires a 4 character value\n");
90 				return 0;
91 			}
92 			break;
93 		case opt_umask:
94 			if (match_octal(&args[0], &tmp)) {
95 				printk("HFS+-fs: umask requires a value\n");
96 				return 0;
97 			}
98 			sbi->umask = (umode_t)tmp;
99 			break;
100 		case opt_uid:
101 			if (match_int(&args[0], &tmp)) {
102 				printk("HFS+-fs: uid requires an argument\n");
103 				return 0;
104 			}
105 			sbi->uid = (uid_t)tmp;
106 			break;
107 		case opt_gid:
108 			if (match_int(&args[0], &tmp)) {
109 				printk("HFS+-fs: gid requires an argument\n");
110 				return 0;
111 			}
112 			sbi->gid = (gid_t)tmp;
113 			break;
114 		case opt_part:
115 			if (match_int(&args[0], &sbi->part)) {
116 				printk("HFS+-fs: part requires an argument\n");
117 				return 0;
118 			}
119 			break;
120 		case opt_session:
121 			if (match_int(&args[0], &sbi->session)) {
122 				printk("HFS+-fs: session requires an argument\n");
123 				return 0;
124 			}
125 			break;
126 		case opt_nls:
127 			if (sbi->nls) {
128 				printk("HFS+-fs: unable to change nls mapping\n");
129 				return 0;
130 			}
131 			p = match_strdup(&args[0]);
132 			sbi->nls = load_nls(p);
133 			if (!sbi->nls) {
134 				printk("HFS+-fs: unable to load nls mapping \"%s\"\n", p);
135 				kfree(p);
136 				return 0;
137 			}
138 			kfree(p);
139 			break;
140 		case opt_decompose:
141 			sbi->flags &= ~HFSPLUS_SB_NODECOMPOSE;
142 			break;
143 		case opt_nodecompose:
144 			sbi->flags |= HFSPLUS_SB_NODECOMPOSE;
145 			break;
146 		default:
147 			return 0;
148 		}
149 	}
150 
151 done:
152 	if (!sbi->nls) {
153 		/* try utf8 first, as this is the old default behaviour */
154 		sbi->nls = load_nls("utf8");
155 		if (!sbi->nls)
156 			sbi->nls = load_nls_default();
157 		if (!sbi->nls)
158 			return 0;
159 	}
160 
161 	return 1;
162 }
163