xref: /openbmc/linux/fs/hfsplus/ioctl.c (revision 8fdff1dc)
1 /*
2  *  linux/fs/hfsplus/ioctl.c
3  *
4  * Copyright (C) 2003
5  * Ethan Benson <erbenson@alaska.net>
6  * partially derived from linux/fs/ext2/ioctl.c
7  * Copyright (C) 1993, 1994, 1995
8  * Remy Card (card@masi.ibp.fr)
9  * Laboratoire MASI - Institut Blaise Pascal
10  * Universite Pierre et Marie Curie (Paris VI)
11  *
12  * hfsplus ioctls
13  */
14 
15 #include <linux/capability.h>
16 #include <linux/fs.h>
17 #include <linux/mount.h>
18 #include <linux/sched.h>
19 #include <linux/xattr.h>
20 #include <asm/uaccess.h>
21 #include "hfsplus_fs.h"
22 
23 /*
24  * "Blessing" an HFS+ filesystem writes metadata to the superblock informing
25  * the platform firmware which file to boot from
26  */
27 static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags)
28 {
29 	struct dentry *dentry = file->f_path.dentry;
30 	struct inode *inode = dentry->d_inode;
31 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
32 	struct hfsplus_vh *vh = sbi->s_vhdr;
33 	struct hfsplus_vh *bvh = sbi->s_backup_vhdr;
34 	u32 cnid = (unsigned long)dentry->d_fsdata;
35 
36 	if (!capable(CAP_SYS_ADMIN))
37 		return -EPERM;
38 
39 	mutex_lock(&sbi->vh_mutex);
40 
41 	/* Directory containing the bootable system */
42 	vh->finder_info[0] = bvh->finder_info[0] =
43 		cpu_to_be32(parent_ino(dentry));
44 
45 	/*
46 	 * Bootloader. Just using the inode here breaks in the case of
47 	 * hard links - the firmware wants the ID of the hard link file,
48 	 * but the inode points at the indirect inode
49 	 */
50 	vh->finder_info[1] = bvh->finder_info[1] = cpu_to_be32(cnid);
51 
52 	/* Per spec, the OS X system folder - same as finder_info[0] here */
53 	vh->finder_info[5] = bvh->finder_info[5] =
54 		cpu_to_be32(parent_ino(dentry));
55 
56 	mutex_unlock(&sbi->vh_mutex);
57 	return 0;
58 }
59 
60 static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags)
61 {
62 	struct inode *inode = file->f_path.dentry->d_inode;
63 	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
64 	unsigned int flags = 0;
65 
66 	if (inode->i_flags & S_IMMUTABLE)
67 		flags |= FS_IMMUTABLE_FL;
68 	if (inode->i_flags & S_APPEND)
69 		flags |= FS_APPEND_FL;
70 	if (hip->userflags & HFSPLUS_FLG_NODUMP)
71 		flags |= FS_NODUMP_FL;
72 
73 	return put_user(flags, user_flags);
74 }
75 
76 static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags)
77 {
78 	struct inode *inode = file->f_path.dentry->d_inode;
79 	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
80 	unsigned int flags;
81 	int err = 0;
82 
83 	err = mnt_want_write_file(file);
84 	if (err)
85 		goto out;
86 
87 	if (!inode_owner_or_capable(inode)) {
88 		err = -EACCES;
89 		goto out_drop_write;
90 	}
91 
92 	if (get_user(flags, user_flags)) {
93 		err = -EFAULT;
94 		goto out_drop_write;
95 	}
96 
97 	mutex_lock(&inode->i_mutex);
98 
99 	if ((flags & (FS_IMMUTABLE_FL|FS_APPEND_FL)) ||
100 	    inode->i_flags & (S_IMMUTABLE|S_APPEND)) {
101 		if (!capable(CAP_LINUX_IMMUTABLE)) {
102 			err = -EPERM;
103 			goto out_unlock_inode;
104 		}
105 	}
106 
107 	/* don't silently ignore unsupported ext2 flags */
108 	if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) {
109 		err = -EOPNOTSUPP;
110 		goto out_unlock_inode;
111 	}
112 
113 	if (flags & FS_IMMUTABLE_FL)
114 		inode->i_flags |= S_IMMUTABLE;
115 	else
116 		inode->i_flags &= ~S_IMMUTABLE;
117 
118 	if (flags & FS_APPEND_FL)
119 		inode->i_flags |= S_APPEND;
120 	else
121 		inode->i_flags &= ~S_APPEND;
122 
123 	if (flags & FS_NODUMP_FL)
124 		hip->userflags |= HFSPLUS_FLG_NODUMP;
125 	else
126 		hip->userflags &= ~HFSPLUS_FLG_NODUMP;
127 
128 	inode->i_ctime = CURRENT_TIME_SEC;
129 	mark_inode_dirty(inode);
130 
131 out_unlock_inode:
132 	mutex_unlock(&inode->i_mutex);
133 out_drop_write:
134 	mnt_drop_write_file(file);
135 out:
136 	return err;
137 }
138 
139 long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
140 {
141 	void __user *argp = (void __user *)arg;
142 
143 	switch (cmd) {
144 	case HFSPLUS_IOC_EXT2_GETFLAGS:
145 		return hfsplus_ioctl_getflags(file, argp);
146 	case HFSPLUS_IOC_EXT2_SETFLAGS:
147 		return hfsplus_ioctl_setflags(file, argp);
148 	case HFSPLUS_IOC_BLESS:
149 		return hfsplus_ioctl_bless(file, argp);
150 	default:
151 		return -ENOTTY;
152 	}
153 }
154 
155 int hfsplus_setxattr(struct dentry *dentry, const char *name,
156 		     const void *value, size_t size, int flags)
157 {
158 	struct inode *inode = dentry->d_inode;
159 	struct hfs_find_data fd;
160 	hfsplus_cat_entry entry;
161 	struct hfsplus_cat_file *file;
162 	int res;
163 
164 	if (!S_ISREG(inode->i_mode) || HFSPLUS_IS_RSRC(inode))
165 		return -EOPNOTSUPP;
166 
167 	res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
168 	if (res)
169 		return res;
170 	res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
171 	if (res)
172 		goto out;
173 	hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
174 			sizeof(struct hfsplus_cat_file));
175 	file = &entry.file;
176 
177 	if (!strcmp(name, "hfs.type")) {
178 		if (size == 4)
179 			memcpy(&file->user_info.fdType, value, 4);
180 		else
181 			res = -ERANGE;
182 	} else if (!strcmp(name, "hfs.creator")) {
183 		if (size == 4)
184 			memcpy(&file->user_info.fdCreator, value, 4);
185 		else
186 			res = -ERANGE;
187 	} else
188 		res = -EOPNOTSUPP;
189 	if (!res) {
190 		hfs_bnode_write(fd.bnode, &entry, fd.entryoffset,
191 				sizeof(struct hfsplus_cat_file));
192 		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
193 	}
194 out:
195 	hfs_find_exit(&fd);
196 	return res;
197 }
198 
199 ssize_t hfsplus_getxattr(struct dentry *dentry, const char *name,
200 			 void *value, size_t size)
201 {
202 	struct inode *inode = dentry->d_inode;
203 	struct hfs_find_data fd;
204 	hfsplus_cat_entry entry;
205 	struct hfsplus_cat_file *file;
206 	ssize_t res = 0;
207 
208 	if (!S_ISREG(inode->i_mode) || HFSPLUS_IS_RSRC(inode))
209 		return -EOPNOTSUPP;
210 
211 	if (size) {
212 		res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
213 		if (res)
214 			return res;
215 		res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
216 		if (res)
217 			goto out;
218 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
219 				sizeof(struct hfsplus_cat_file));
220 	}
221 	file = &entry.file;
222 
223 	if (!strcmp(name, "hfs.type")) {
224 		if (size >= 4) {
225 			memcpy(value, &file->user_info.fdType, 4);
226 			res = 4;
227 		} else
228 			res = size ? -ERANGE : 4;
229 	} else if (!strcmp(name, "hfs.creator")) {
230 		if (size >= 4) {
231 			memcpy(value, &file->user_info.fdCreator, 4);
232 			res = 4;
233 		} else
234 			res = size ? -ERANGE : 4;
235 	} else
236 		res = -EOPNOTSUPP;
237 out:
238 	if (size)
239 		hfs_find_exit(&fd);
240 	return res;
241 }
242 
243 #define HFSPLUS_ATTRLIST_SIZE (sizeof("hfs.creator")+sizeof("hfs.type"))
244 
245 ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
246 {
247 	struct inode *inode = dentry->d_inode;
248 
249 	if (!S_ISREG(inode->i_mode) || HFSPLUS_IS_RSRC(inode))
250 		return -EOPNOTSUPP;
251 
252 	if (!buffer || !size)
253 		return HFSPLUS_ATTRLIST_SIZE;
254 	if (size < HFSPLUS_ATTRLIST_SIZE)
255 		return -ERANGE;
256 	strcpy(buffer, "hfs.type");
257 	strcpy(buffer + sizeof("hfs.type"), "hfs.creator");
258 
259 	return HFSPLUS_ATTRLIST_SIZE;
260 }
261