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