xref: /linux/fs/hfsplus/options.c (revision 79d2e1919a2728ef49d938eb20ebd5903c14dfb0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/hfsplus/options.c
4  *
5  * Copyright (C) 2001
6  * Brad Boyer (flar@allandria.com)
7  * (C) 2003 Ardis Technologies <roman@ardistech.com>
8  *
9  * Option parsing
10  */
11 
12 #include <linux/string.h>
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/fs_context.h>
16 #include <linux/fs_parser.h>
17 #include <linux/nls.h>
18 #include <linux/mount.h>
19 #include <linux/seq_file.h>
20 #include <linux/slab.h>
21 #include "hfsplus_fs.h"
22 
23 enum {
24 	opt_creator, opt_type,
25 	opt_umask, opt_uid, opt_gid,
26 	opt_part, opt_session, opt_nls,
27 	opt_decompose, opt_barrier,
28 	opt_force,
29 };
30 
31 static const struct fs_parameter_spec hfs_param_spec[] = {
32 	fsparam_string	("creator",	opt_creator),
33 	fsparam_string	("type",	opt_type),
34 	fsparam_u32oct	("umask",	opt_umask),
35 	fsparam_u32	("uid",		opt_uid),
36 	fsparam_u32	("gid",		opt_gid),
37 	fsparam_u32	("part",	opt_part),
38 	fsparam_u32	("session",	opt_session),
39 	fsparam_string	("nls",		opt_nls),
40 	fsparam_flag_no	("decompose",	opt_decompose),
41 	fsparam_flag_no	("barrier",	opt_barrier),
42 	fsparam_flag	("force",	opt_force),
43 	{}
44 };
45 
46 /* Initialize an options object to reasonable defaults */
47 void hfsplus_fill_defaults(struct hfsplus_sb_info *opts)
48 {
49 	if (!opts)
50 		return;
51 
52 	opts->creator = HFSPLUS_DEF_CR_TYPE;
53 	opts->type = HFSPLUS_DEF_CR_TYPE;
54 	opts->umask = current_umask();
55 	opts->uid = current_uid();
56 	opts->gid = current_gid();
57 	opts->part = -1;
58 	opts->session = -1;
59 }
60 
61 /* Parse options from mount. Returns nonzero errno on failure */
62 int hfsplus_parse_param(struct fs_context *fc, struct fs_parameter *param)
63 {
64 	struct hfsplus_sb_info *sbi = fc->s_fs_info;
65 	struct fs_parse_result result;
66 	int opt;
67 
68 	/*
69 	 * Only the force option is examined during remount, all others
70 	 * are ignored.
71 	 */
72 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE &&
73 	    strncmp(param->key, "force", 5))
74 		return 0;
75 
76 	opt = fs_parse(fc, hfs_param_spec, param, &result);
77 	if (opt < 0)
78 		return opt;
79 
80 	switch (opt) {
81 	case opt_creator:
82 		if (strlen(param->string) != 4) {
83 			pr_err("creator requires a 4 character value\n");
84 			return -EINVAL;
85 		}
86 		memcpy(&sbi->creator, param->string, 4);
87 		break;
88 	case opt_type:
89 		if (strlen(param->string) != 4) {
90 			pr_err("type requires a 4 character value\n");
91 			return -EINVAL;
92 		}
93 		memcpy(&sbi->type, param->string, 4);
94 		break;
95 	case opt_umask:
96 		sbi->umask = (umode_t)result.uint_32;
97 		break;
98 	case opt_uid:
99 		sbi->uid = result.uid;
100 		set_bit(HFSPLUS_SB_UID, &sbi->flags);
101 		break;
102 	case opt_gid:
103 		sbi->gid = result.gid;
104 		set_bit(HFSPLUS_SB_GID, &sbi->flags);
105 		break;
106 	case opt_part:
107 		sbi->part = result.uint_32;
108 		break;
109 	case opt_session:
110 		sbi->session = result.uint_32;
111 		break;
112 	case opt_nls:
113 		if (sbi->nls) {
114 			pr_err("unable to change nls mapping\n");
115 			return -EINVAL;
116 		}
117 		sbi->nls = load_nls(param->string);
118 		if (!sbi->nls) {
119 			pr_err("unable to load nls mapping \"%s\"\n",
120 			       param->string);
121 			return -EINVAL;
122 		}
123 		break;
124 	case opt_decompose:
125 		if (result.negated)
126 			set_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
127 		else
128 			clear_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
129 		break;
130 	case opt_barrier:
131 		if (result.negated)
132 			set_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
133 		else
134 			clear_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
135 		break;
136 	case opt_force:
137 		set_bit(HFSPLUS_SB_FORCE, &sbi->flags);
138 		break;
139 	default:
140 		return -EINVAL;
141 	}
142 
143 	return 0;
144 }
145 
146 int hfsplus_show_options(struct seq_file *seq, struct dentry *root)
147 {
148 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(root->d_sb);
149 
150 	if (sbi->creator != HFSPLUS_DEF_CR_TYPE)
151 		seq_show_option_n(seq, "creator", (char *)&sbi->creator, 4);
152 	if (sbi->type != HFSPLUS_DEF_CR_TYPE)
153 		seq_show_option_n(seq, "type", (char *)&sbi->type, 4);
154 	seq_printf(seq, ",umask=%o,uid=%u,gid=%u", sbi->umask,
155 			from_kuid_munged(&init_user_ns, sbi->uid),
156 			from_kgid_munged(&init_user_ns, sbi->gid));
157 	if (sbi->part >= 0)
158 		seq_printf(seq, ",part=%u", sbi->part);
159 	if (sbi->session >= 0)
160 		seq_printf(seq, ",session=%u", sbi->session);
161 	if (sbi->nls)
162 		seq_printf(seq, ",nls=%s", sbi->nls->charset);
163 	if (test_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags))
164 		seq_puts(seq, ",nodecompose");
165 	if (test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
166 		seq_puts(seq, ",nobarrier");
167 	return 0;
168 }
169