xref: /linux/fs/hfsplus/options.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 <linux/mount.h>
17 #include <linux/seq_file.h>
18 #include <linux/slab.h>
19 #include "hfsplus_fs.h"
20 
21 enum {
22 	opt_creator, opt_type,
23 	opt_umask, opt_uid, opt_gid,
24 	opt_part, opt_session, opt_nls,
25 	opt_nodecompose, opt_decompose,
26 	opt_force, opt_err
27 };
28 
29 static const match_table_t tokens = {
30 	{ opt_creator, "creator=%s" },
31 	{ opt_type, "type=%s" },
32 	{ opt_umask, "umask=%o" },
33 	{ opt_uid, "uid=%u" },
34 	{ opt_gid, "gid=%u" },
35 	{ opt_part, "part=%u" },
36 	{ opt_session, "session=%u" },
37 	{ opt_nls, "nls=%s" },
38 	{ opt_decompose, "decompose" },
39 	{ opt_nodecompose, "nodecompose" },
40 	{ opt_force, "force" },
41 	{ opt_err, NULL }
42 };
43 
44 /* Initialize an options object to reasonable defaults */
45 void hfsplus_fill_defaults(struct hfsplus_sb_info *opts)
46 {
47 	if (!opts)
48 		return;
49 
50 	opts->creator = HFSPLUS_DEF_CR_TYPE;
51 	opts->type = HFSPLUS_DEF_CR_TYPE;
52 	opts->umask = current_umask();
53 	opts->uid = current_uid();
54 	opts->gid = current_gid();
55 	opts->part = -1;
56 	opts->session = -1;
57 }
58 
59 /* convert a "four byte character" to a 32 bit int with error checks */
60 static inline int match_fourchar(substring_t *arg, u32 *result)
61 {
62 	if (arg->to - arg->from != 4)
63 		return -EINVAL;
64 	memcpy(result, arg->from, 4);
65 	return 0;
66 }
67 
68 /* Parse options from mount. Returns 0 on failure */
69 /* input is the options passed to mount() as a string */
70 int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
71 {
72 	char *p;
73 	substring_t args[MAX_OPT_ARGS];
74 	int tmp, token;
75 
76 	if (!input)
77 		goto done;
78 
79 	while ((p = strsep(&input, ",")) != NULL) {
80 		if (!*p)
81 			continue;
82 
83 		token = match_token(p, tokens, args);
84 		switch (token) {
85 		case opt_creator:
86 			if (match_fourchar(&args[0], &sbi->creator)) {
87 				printk(KERN_ERR "hfs: creator requires a 4 character value\n");
88 				return 0;
89 			}
90 			break;
91 		case opt_type:
92 			if (match_fourchar(&args[0], &sbi->type)) {
93 				printk(KERN_ERR "hfs: type requires a 4 character value\n");
94 				return 0;
95 			}
96 			break;
97 		case opt_umask:
98 			if (match_octal(&args[0], &tmp)) {
99 				printk(KERN_ERR "hfs: umask requires a value\n");
100 				return 0;
101 			}
102 			sbi->umask = (umode_t)tmp;
103 			break;
104 		case opt_uid:
105 			if (match_int(&args[0], &tmp)) {
106 				printk(KERN_ERR "hfs: uid requires an argument\n");
107 				return 0;
108 			}
109 			sbi->uid = (uid_t)tmp;
110 			break;
111 		case opt_gid:
112 			if (match_int(&args[0], &tmp)) {
113 				printk(KERN_ERR "hfs: gid requires an argument\n");
114 				return 0;
115 			}
116 			sbi->gid = (gid_t)tmp;
117 			break;
118 		case opt_part:
119 			if (match_int(&args[0], &sbi->part)) {
120 				printk(KERN_ERR "hfs: part requires an argument\n");
121 				return 0;
122 			}
123 			break;
124 		case opt_session:
125 			if (match_int(&args[0], &sbi->session)) {
126 				printk(KERN_ERR "hfs: session requires an argument\n");
127 				return 0;
128 			}
129 			break;
130 		case opt_nls:
131 			if (sbi->nls) {
132 				printk(KERN_ERR "hfs: unable to change nls mapping\n");
133 				return 0;
134 			}
135 			p = match_strdup(&args[0]);
136 			if (p)
137 				sbi->nls = load_nls(p);
138 			if (!sbi->nls) {
139 				printk(KERN_ERR "hfs: unable to load nls mapping \"%s\"\n", p);
140 				kfree(p);
141 				return 0;
142 			}
143 			kfree(p);
144 			break;
145 		case opt_decompose:
146 			sbi->flags &= ~HFSPLUS_SB_NODECOMPOSE;
147 			break;
148 		case opt_nodecompose:
149 			sbi->flags |= HFSPLUS_SB_NODECOMPOSE;
150 			break;
151 		case opt_force:
152 			sbi->flags |= HFSPLUS_SB_FORCE;
153 			break;
154 		default:
155 			return 0;
156 		}
157 	}
158 
159 done:
160 	if (!sbi->nls) {
161 		/* try utf8 first, as this is the old default behaviour */
162 		sbi->nls = load_nls("utf8");
163 		if (!sbi->nls)
164 			sbi->nls = load_nls_default();
165 		if (!sbi->nls)
166 			return 0;
167 	}
168 
169 	return 1;
170 }
171 
172 int hfsplus_show_options(struct seq_file *seq, struct vfsmount *mnt)
173 {
174 	struct hfsplus_sb_info *sbi = &HFSPLUS_SB(mnt->mnt_sb);
175 
176 	if (sbi->creator != HFSPLUS_DEF_CR_TYPE)
177 		seq_printf(seq, ",creator=%.4s", (char *)&sbi->creator);
178 	if (sbi->type != HFSPLUS_DEF_CR_TYPE)
179 		seq_printf(seq, ",type=%.4s", (char *)&sbi->type);
180 	seq_printf(seq, ",umask=%o,uid=%u,gid=%u", sbi->umask, sbi->uid, sbi->gid);
181 	if (sbi->part >= 0)
182 		seq_printf(seq, ",part=%u", sbi->part);
183 	if (sbi->session >= 0)
184 		seq_printf(seq, ",session=%u", sbi->session);
185 	if (sbi->nls)
186 		seq_printf(seq, ",nls=%s", sbi->nls->charset);
187 	if (sbi->flags & HFSPLUS_SB_NODECOMPOSE)
188 		seq_printf(seq, ",nodecompose");
189 	return 0;
190 }
191