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
21enum {
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
30static 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 */
48void 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 */
63static 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
71int 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 1;
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 */
99int 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				pr_err("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				pr_err("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				pr_err("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				pr_err("uid requires an argument\n");
136				return 0;
137			}
138			sbi->uid = make_kuid(current_user_ns(), (uid_t)tmp);
139			if (!uid_valid(sbi->uid)) {
140				pr_err("invalid uid specified\n");
141				return 0;
142			}
143			break;
144		case opt_gid:
145			if (match_int(&args[0], &tmp)) {
146				pr_err("gid requires an argument\n");
147				return 0;
148			}
149			sbi->gid = make_kgid(current_user_ns(), (gid_t)tmp);
150			if (!gid_valid(sbi->gid)) {
151				pr_err("invalid gid specified\n");
152				return 0;
153			}
154			break;
155		case opt_part:
156			if (match_int(&args[0], &sbi->part)) {
157				pr_err("part requires an argument\n");
158				return 0;
159			}
160			break;
161		case opt_session:
162			if (match_int(&args[0], &sbi->session)) {
163				pr_err("session requires an argument\n");
164				return 0;
165			}
166			break;
167		case opt_nls:
168			if (sbi->nls) {
169				pr_err("unable to change nls mapping\n");
170				return 0;
171			}
172			p = match_strdup(&args[0]);
173			if (p)
174				sbi->nls = load_nls(p);
175			if (!sbi->nls) {
176				pr_err("unable to load nls mapping \"%s\"\n",
177				       p);
178				kfree(p);
179				return 0;
180			}
181			kfree(p);
182			break;
183		case opt_decompose:
184			clear_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
185			break;
186		case opt_nodecompose:
187			set_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
188			break;
189		case opt_barrier:
190			clear_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
191			break;
192		case opt_nobarrier:
193			set_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
194			break;
195		case opt_force:
196			set_bit(HFSPLUS_SB_FORCE, &sbi->flags);
197			break;
198		default:
199			return 0;
200		}
201	}
202
203done:
204	if (!sbi->nls) {
205		/* try utf8 first, as this is the old default behaviour */
206		sbi->nls = load_nls("utf8");
207		if (!sbi->nls)
208			sbi->nls = load_nls_default();
209		if (!sbi->nls)
210			return 0;
211	}
212
213	return 1;
214}
215
216int hfsplus_show_options(struct seq_file *seq, struct dentry *root)
217{
218	struct hfsplus_sb_info *sbi = HFSPLUS_SB(root->d_sb);
219
220	if (sbi->creator != HFSPLUS_DEF_CR_TYPE)
221		seq_show_option_n(seq, "creator", (char *)&sbi->creator, 4);
222	if (sbi->type != HFSPLUS_DEF_CR_TYPE)
223		seq_show_option_n(seq, "type", (char *)&sbi->type, 4);
224	seq_printf(seq, ",umask=%o,uid=%u,gid=%u", sbi->umask,
225			from_kuid_munged(&init_user_ns, sbi->uid),
226			from_kgid_munged(&init_user_ns, sbi->gid));
227	if (sbi->part >= 0)
228		seq_printf(seq, ",part=%u", sbi->part);
229	if (sbi->session >= 0)
230		seq_printf(seq, ",session=%u", sbi->session);
231	if (sbi->nls)
232		seq_printf(seq, ",nls=%s", sbi->nls->charset);
233	if (test_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags))
234		seq_puts(seq, ",nodecompose");
235	if (test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
236		seq_puts(seq, ",nobarrier");
237	return 0;
238}
239