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_ioctl_getflags(struct file * file,int __user * user_flags)60 static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags)
61 {
62 struct inode *inode = file_inode(file);
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
hfsplus_ioctl_setflags(struct file * file,int __user * user_flags)76 static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags)
77 {
78 struct inode *inode = file_inode(file);
79 struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
80 unsigned int flags, new_fl = 0;
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 inode_lock(inode);
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 new_fl |= S_IMMUTABLE;
115
116 if (flags & FS_APPEND_FL)
117 new_fl |= S_APPEND;
118
119 inode_set_flags(inode, new_fl, S_IMMUTABLE | S_APPEND);
120
121 if (flags & FS_NODUMP_FL)
122 hip->userflags |= HFSPLUS_FLG_NODUMP;
123 else
124 hip->userflags &= ~HFSPLUS_FLG_NODUMP;
125
126 inode->i_ctime = current_time(inode);
127 mark_inode_dirty(inode);
128
129 out_unlock_inode:
130 inode_unlock(inode);
131 out_drop_write:
132 mnt_drop_write_file(file);
133 out:
134 return err;
135 }
136
hfsplus_ioctl(struct file * file,unsigned int cmd,unsigned long arg)137 long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
138 {
139 void __user *argp = (void __user *)arg;
140
141 switch (cmd) {
142 case HFSPLUS_IOC_EXT2_GETFLAGS:
143 return hfsplus_ioctl_getflags(file, argp);
144 case HFSPLUS_IOC_EXT2_SETFLAGS:
145 return hfsplus_ioctl_setflags(file, argp);
146 case HFSPLUS_IOC_BLESS:
147 return hfsplus_ioctl_bless(file, argp);
148 default:
149 return -ENOTTY;
150 }
151 }
152