xref: /openbmc/linux/fs/hfsplus/options.c (revision 63dc02bd)
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_barrier, opt_nobarrier,
27 	opt_force, opt_err
28 };
29 
30 static const match_table_t tokens = {
31 	{ opt_creator, "creator=%s" },
32 	{ opt_type, "type=%s" },
33 	{ opt_umask, "umask=%o" },
34 	{ opt_uid, "uid=%u" },
35 	{ opt_gid, "gid=%u" },
36 	{ opt_part, "part=%u" },
37 	{ opt_session, "session=%u" },
38 	{ opt_nls, "nls=%s" },
39 	{ opt_decompose, "decompose" },
40 	{ opt_nodecompose, "nodecompose" },
41 	{ opt_barrier, "barrier" },
42 	{ opt_nobarrier, "nobarrier" },
43 	{ opt_force, "force" },
44 	{ opt_err, NULL }
45 };
46 
47 /* Initialize an options object to reasonable defaults */
48 void hfsplus_fill_defaults(struct hfsplus_sb_info *opts)
49 {
50 	if (!opts)
51 		return;
52 
53 	opts->creator = HFSPLUS_DEF_CR_TYPE;
54 	opts->type = HFSPLUS_DEF_CR_TYPE;
55 	opts->umask = current_umask();
56 	opts->uid = current_uid();
57 	opts->gid = current_gid();
58 	opts->part = -1;
59 	opts->session = -1;
60 }
61 
62 /* convert a "four byte character" to a 32 bit int with error checks */
63 static inline int match_fourchar(substring_t *arg, u32 *result)
64 {
65 	if (arg->to - arg->from != 4)
66 		return -EINVAL;
67 	memcpy(result, arg->from, 4);
68 	return 0;
69 }
70 
71 int hfsplus_parse_options_remount(char *input, int *force)
72 {
73 	char *p;
74 	substring_t args[MAX_OPT_ARGS];
75 	int token;
76 
77 	if (!input)
78 		return 0;
79 
80 	while ((p = strsep(&input, ",")) != NULL) {
81 		if (!*p)
82 			continue;
83 
84 		token = match_token(p, tokens, args);
85 		switch (token) {
86 		case opt_force:
87 			*force = 1;
88 			break;
89 		default:
90 			break;
91 		}
92 	}
93 
94 	return 1;
95 }
96 
97 /* Parse options from mount. Returns 0 on failure */
98 /* input is the options passed to mount() as a string */
99 int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
100 {
101 	char *p;
102 	substring_t args[MAX_OPT_ARGS];
103 	int tmp, token;
104 
105 	if (!input)
106 		goto done;
107 
108 	while ((p = strsep(&input, ",")) != NULL) {
109 		if (!*p)
110 			continue;
111 
112 		token = match_token(p, tokens, args);
113 		switch (token) {
114 		case opt_creator:
115 			if (match_fourchar(&args[0], &sbi->creator)) {
116 				printk(KERN_ERR "hfs: creator requires a 4 character value\n");
117 				return 0;
118 			}
119 			break;
120 		case opt_type:
121 			if (match_fourchar(&args[0], &sbi->type)) {
122 				printk(KERN_ERR "hfs: type requires a 4 character value\n");
123 				return 0;
124 			}
125 			break;
126 		case opt_umask:
127 			if (match_octal(&args[0], &tmp)) {
128 				printk(KERN_ERR "hfs: umask requires a value\n");
129 				return 0;
130 			}
131 			sbi->umask = (umode_t)tmp;
132 			break;
133 		case opt_uid:
134 			if (match_int(&args[0], &tmp)) {
135 				printk(KERN_ERR "hfs: uid requires an argument\n");
136 				return 0;
137 			}
138 			sbi->uid = (uid_t)tmp;
139 			break;
140 		case opt_gid:
141 			if (match_int(&args[0], &tmp)) {
142 				printk(KERN_ERR "hfs: gid requires an argument\n");
143 				return 0;
144 			}
145 			sbi->gid = (gid_t)tmp;
146 			break;
147 		case opt_part:
148 			if (match_int(&args[0], &sbi->part)) {
149 				printk(KERN_ERR "hfs: part requires an argument\n");
150 				return 0;
151 			}
152 			break;
153 		case opt_session:
154 			if (match_int(&args[0], &sbi->session)) {
155 				printk(KERN_ERR "hfs: session requires an argument\n");
156 				return 0;
157 			}
158 			break;
159 		case opt_nls:
160 			if (sbi->nls) {
161 				printk(KERN_ERR "hfs: unable to change nls mapping\n");
162 				return 0;
163 			}
164 			p = match_strdup(&args[0]);
165 			if (p)
166 				sbi->nls = load_nls(p);
167 			if (!sbi->nls) {
168 				printk(KERN_ERR "hfs: unable to load "
169 						"nls mapping \"%s\"\n",
170 					p);
171 				kfree(p);
172 				return 0;
173 			}
174 			kfree(p);
175 			break;
176 		case opt_decompose:
177 			clear_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
178 			break;
179 		case opt_nodecompose:
180 			set_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
181 			break;
182 		case opt_barrier:
183 			clear_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
184 			break;
185 		case opt_nobarrier:
186 			set_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
187 			break;
188 		case opt_force:
189 			set_bit(HFSPLUS_SB_FORCE, &sbi->flags);
190 			break;
191 		default:
192 			return 0;
193 		}
194 	}
195 
196 done:
197 	if (!sbi->nls) {
198 		/* try utf8 first, as this is the old default behaviour */
199 		sbi->nls = load_nls("utf8");
200 		if (!sbi->nls)
201 			sbi->nls = load_nls_default();
202 		if (!sbi->nls)
203 			return 0;
204 	}
205 
206 	return 1;
207 }
208 
209 int hfsplus_show_options(struct seq_file *seq, struct dentry *root)
210 {
211 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(root->d_sb);
212 
213 	if (sbi->creator != HFSPLUS_DEF_CR_TYPE)
214 		seq_printf(seq, ",creator=%.4s", (char *)&sbi->creator);
215 	if (sbi->type != HFSPLUS_DEF_CR_TYPE)
216 		seq_printf(seq, ",type=%.4s", (char *)&sbi->type);
217 	seq_printf(seq, ",umask=%o,uid=%u,gid=%u", sbi->umask,
218 		sbi->uid, sbi->gid);
219 	if (sbi->part >= 0)
220 		seq_printf(seq, ",part=%u", sbi->part);
221 	if (sbi->session >= 0)
222 		seq_printf(seq, ",session=%u", sbi->session);
223 	if (sbi->nls)
224 		seq_printf(seq, ",nls=%s", sbi->nls->charset);
225 	if (test_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags))
226 		seq_printf(seq, ",nodecompose");
227 	if (test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
228 		seq_printf(seq, ",nobarrier");
229 	return 0;
230 }
231