xref: /linux/fs/ubifs/ioctl.c (revision aa23aa55166c2865ac430168c4b9d405cf8c6980)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * This file is part of UBIFS.
4  *
5  * Copyright (C) 2006-2008 Nokia Corporation.
6  * Copyright (C) 2006, 2007 University of Szeged, Hungary
7  *
8  * Authors: Zoltan Sogor
9  *          Artem Bityutskiy (Битюцкий Артём)
10  *          Adrian Hunter
11  */
12 
13 /* This file implements EXT2-compatible extended attribute ioctl() calls */
14 
15 #include <linux/compat.h>
16 #include <linux/mount.h>
17 #include "ubifs.h"
18 
19 /* Need to be kept consistent with checked flags in ioctl2ubifs() */
20 #define UBIFS_SUPPORTED_IOCTL_FLAGS \
21 	(FS_COMPR_FL | FS_SYNC_FL | FS_APPEND_FL | \
22 	 FS_IMMUTABLE_FL | FS_DIRSYNC_FL)
23 
24 /**
25  * ubifs_set_inode_flags - set VFS inode flags.
26  * @inode: VFS inode to set flags for
27  *
28  * This function propagates flags from UBIFS inode object to VFS inode object.
29  */
30 void ubifs_set_inode_flags(struct inode *inode)
31 {
32 	unsigned int flags = ubifs_inode(inode)->flags;
33 
34 	inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC |
35 			    S_ENCRYPTED);
36 	if (flags & UBIFS_SYNC_FL)
37 		inode->i_flags |= S_SYNC;
38 	if (flags & UBIFS_APPEND_FL)
39 		inode->i_flags |= S_APPEND;
40 	if (flags & UBIFS_IMMUTABLE_FL)
41 		inode->i_flags |= S_IMMUTABLE;
42 	if (flags & UBIFS_DIRSYNC_FL)
43 		inode->i_flags |= S_DIRSYNC;
44 	if (flags & UBIFS_CRYPT_FL)
45 		inode->i_flags |= S_ENCRYPTED;
46 }
47 
48 /*
49  * ioctl2ubifs - convert ioctl inode flags to UBIFS inode flags.
50  * @ioctl_flags: flags to convert
51  *
52  * This function converts ioctl flags (@FS_COMPR_FL, etc) to UBIFS inode flags
53  * (@UBIFS_COMPR_FL, etc).
54  */
55 static int ioctl2ubifs(int ioctl_flags)
56 {
57 	int ubifs_flags = 0;
58 
59 	if (ioctl_flags & FS_COMPR_FL)
60 		ubifs_flags |= UBIFS_COMPR_FL;
61 	if (ioctl_flags & FS_SYNC_FL)
62 		ubifs_flags |= UBIFS_SYNC_FL;
63 	if (ioctl_flags & FS_APPEND_FL)
64 		ubifs_flags |= UBIFS_APPEND_FL;
65 	if (ioctl_flags & FS_IMMUTABLE_FL)
66 		ubifs_flags |= UBIFS_IMMUTABLE_FL;
67 	if (ioctl_flags & FS_DIRSYNC_FL)
68 		ubifs_flags |= UBIFS_DIRSYNC_FL;
69 
70 	return ubifs_flags;
71 }
72 
73 /*
74  * ubifs2ioctl - convert UBIFS inode flags to ioctl inode flags.
75  * @ubifs_flags: flags to convert
76  *
77  * This function converts UBIFS inode flags (@UBIFS_COMPR_FL, etc) to ioctl
78  * flags (@FS_COMPR_FL, etc).
79  */
80 static int ubifs2ioctl(int ubifs_flags)
81 {
82 	int ioctl_flags = 0;
83 
84 	if (ubifs_flags & UBIFS_COMPR_FL)
85 		ioctl_flags |= FS_COMPR_FL;
86 	if (ubifs_flags & UBIFS_SYNC_FL)
87 		ioctl_flags |= FS_SYNC_FL;
88 	if (ubifs_flags & UBIFS_APPEND_FL)
89 		ioctl_flags |= FS_APPEND_FL;
90 	if (ubifs_flags & UBIFS_IMMUTABLE_FL)
91 		ioctl_flags |= FS_IMMUTABLE_FL;
92 	if (ubifs_flags & UBIFS_DIRSYNC_FL)
93 		ioctl_flags |= FS_DIRSYNC_FL;
94 
95 	return ioctl_flags;
96 }
97 
98 static int setflags(struct inode *inode, int flags)
99 {
100 	int oldflags, err, release;
101 	struct ubifs_inode *ui = ubifs_inode(inode);
102 	struct ubifs_info *c = inode->i_sb->s_fs_info;
103 	struct ubifs_budget_req req = { .dirtied_ino = 1,
104 					.dirtied_ino_d = ui->data_len };
105 
106 	err = ubifs_budget_space(c, &req);
107 	if (err)
108 		return err;
109 
110 	/*
111 	 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
112 	 * the relevant capability.
113 	 */
114 	mutex_lock(&ui->ui_mutex);
115 	oldflags = ubifs2ioctl(ui->flags);
116 	if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
117 		if (!capable(CAP_LINUX_IMMUTABLE)) {
118 			err = -EPERM;
119 			goto out_unlock;
120 		}
121 	}
122 
123 	ui->flags = ioctl2ubifs(flags);
124 	ubifs_set_inode_flags(inode);
125 	inode->i_ctime = current_time(inode);
126 	release = ui->dirty;
127 	mark_inode_dirty_sync(inode);
128 	mutex_unlock(&ui->ui_mutex);
129 
130 	if (release)
131 		ubifs_release_budget(c, &req);
132 	if (IS_SYNC(inode))
133 		err = write_inode_now(inode, 1);
134 	return err;
135 
136 out_unlock:
137 	ubifs_err(c, "can't modify inode %lu attributes", inode->i_ino);
138 	mutex_unlock(&ui->ui_mutex);
139 	ubifs_release_budget(c, &req);
140 	return err;
141 }
142 
143 long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
144 {
145 	int flags, err;
146 	struct inode *inode = file_inode(file);
147 
148 	switch (cmd) {
149 	case FS_IOC_GETFLAGS:
150 		flags = ubifs2ioctl(ubifs_inode(inode)->flags);
151 
152 		dbg_gen("get flags: %#x, i_flags %#x", flags, inode->i_flags);
153 		return put_user(flags, (int __user *) arg);
154 
155 	case FS_IOC_SETFLAGS: {
156 		if (IS_RDONLY(inode))
157 			return -EROFS;
158 
159 		if (!inode_owner_or_capable(inode))
160 			return -EACCES;
161 
162 		if (get_user(flags, (int __user *) arg))
163 			return -EFAULT;
164 
165 		if (flags & ~UBIFS_SUPPORTED_IOCTL_FLAGS)
166 			return -EOPNOTSUPP;
167 
168 		if (!S_ISDIR(inode->i_mode))
169 			flags &= ~FS_DIRSYNC_FL;
170 
171 		/*
172 		 * Make sure the file-system is read-write and make sure it
173 		 * will not become read-only while we are changing the flags.
174 		 */
175 		err = mnt_want_write_file(file);
176 		if (err)
177 			return err;
178 		dbg_gen("set flags: %#x, i_flags %#x", flags, inode->i_flags);
179 		err = setflags(inode, flags);
180 		mnt_drop_write_file(file);
181 		return err;
182 	}
183 	case FS_IOC_SET_ENCRYPTION_POLICY: {
184 		struct ubifs_info *c = inode->i_sb->s_fs_info;
185 
186 		err = ubifs_enable_encryption(c);
187 		if (err)
188 			return err;
189 
190 		return fscrypt_ioctl_set_policy(file, (const void __user *)arg);
191 	}
192 	case FS_IOC_GET_ENCRYPTION_POLICY:
193 		return fscrypt_ioctl_get_policy(file, (void __user *)arg);
194 
195 	default:
196 		return -ENOTTY;
197 	}
198 }
199 
200 #ifdef CONFIG_COMPAT
201 long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
202 {
203 	switch (cmd) {
204 	case FS_IOC32_GETFLAGS:
205 		cmd = FS_IOC_GETFLAGS;
206 		break;
207 	case FS_IOC32_SETFLAGS:
208 		cmd = FS_IOC_SETFLAGS;
209 		break;
210 	case FS_IOC_SET_ENCRYPTION_POLICY:
211 	case FS_IOC_GET_ENCRYPTION_POLICY:
212 		break;
213 	default:
214 		return -ENOIOCTLCMD;
215 	}
216 	return ubifs_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
217 }
218 #endif
219