1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/fs/hfsplus/ioctl.c
4 *
5 * Copyright (C) 2003
6 * Ethan Benson <erbenson@alaska.net>
7 * partially derived from linux/fs/ext2/ioctl.c
8 * Copyright (C) 1993, 1994, 1995
9 * Remy Card (card@masi.ibp.fr)
10 * Laboratoire MASI - Institut Blaise Pascal
11 * Universite Pierre et Marie Curie (Paris VI)
12 *
13 * hfsplus ioctls
14 */
15
16 #include <linux/capability.h>
17 #include <linux/fs.h>
18 #include <linux/mount.h>
19 #include <linux/sched.h>
20 #include <linux/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 */
hfsplus_ioctl_bless(struct file * file,int __user * user_flags)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 = d_inode(dentry);
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
hfsplus_getflags(struct inode * inode)60 static inline unsigned int hfsplus_getflags(struct inode *inode)
61 {
62 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
63 unsigned int flags = 0;
64
65 if (inode->i_flags & S_IMMUTABLE)
66 flags |= FS_IMMUTABLE_FL;
67 if (inode->i_flags & S_APPEND)
68 flags |= FS_APPEND_FL;
69 if (hip->userflags & HFSPLUS_FLG_NODUMP)
70 flags |= FS_NODUMP_FL;
71 return flags;
72 }
73
hfsplus_ioctl_getflags(struct file * file,int __user * user_flags)74 static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags)
75 {
76 struct inode *inode = file_inode(file);
77 unsigned int flags = hfsplus_getflags(inode);
78
79 return put_user(flags, user_flags);
80 }
81
hfsplus_ioctl_setflags(struct file * file,int __user * user_flags)82 static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags)
83 {
84 struct inode *inode = file_inode(file);
85 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
86 unsigned int flags, new_fl = 0;
87 unsigned int oldflags = hfsplus_getflags(inode);
88 int err = 0;
89
90 err = mnt_want_write_file(file);
91 if (err)
92 goto out;
93
94 if (!inode_owner_or_capable(inode)) {
95 err = -EACCES;
96 goto out_drop_write;
97 }
98
99 if (get_user(flags, user_flags)) {
100 err = -EFAULT;
101 goto out_drop_write;
102 }
103
104 inode_lock(inode);
105
106 err = vfs_ioc_setflags_prepare(inode, oldflags, flags);
107 if (err)
108 goto out_unlock_inode;
109
110 /* don't silently ignore unsupported ext2 flags */
111 if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) {
112 err = -EOPNOTSUPP;
113 goto out_unlock_inode;
114 }
115
116 if (flags & FS_IMMUTABLE_FL)
117 new_fl |= S_IMMUTABLE;
118
119 if (flags & FS_APPEND_FL)
120 new_fl |= S_APPEND;
121
122 inode_set_flags(inode, new_fl, S_IMMUTABLE | S_APPEND);
123
124 if (flags & FS_NODUMP_FL)
125 hip->userflags |= HFSPLUS_FLG_NODUMP;
126 else
127 hip->userflags &= ~HFSPLUS_FLG_NODUMP;
128
129 inode->i_ctime = current_time(inode);
130 mark_inode_dirty(inode);
131
132 out_unlock_inode:
133 inode_unlock(inode);
134 out_drop_write:
135 mnt_drop_write_file(file);
136 out:
137 return err;
138 }
139
hfsplus_ioctl(struct file * file,unsigned int cmd,unsigned long arg)140 long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
141 {
142 void __user *argp = (void __user *)arg;
143
144 switch (cmd) {
145 case HFSPLUS_IOC_EXT2_GETFLAGS:
146 return hfsplus_ioctl_getflags(file, argp);
147 case HFSPLUS_IOC_EXT2_SETFLAGS:
148 return hfsplus_ioctl_setflags(file, argp);
149 case HFSPLUS_IOC_BLESS:
150 return hfsplus_ioctl_bless(file, argp);
151 default:
152 return -ENOTTY;
153 }
154 }
155