Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 1 | /* |
| 2 | * inode.c - securityfs |
| 3 | * |
| 4 | * Copyright (C) 2005 Greg Kroah-Hartman <gregkh@suse.de> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License version |
| 8 | * 2 as published by the Free Software Foundation. |
| 9 | * |
| 10 | * Based on fs/debugfs/inode.c which had the following copyright notice: |
| 11 | * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> |
| 12 | * Copyright (C) 2004 IBM Inc. |
| 13 | */ |
| 14 | |
| 15 | /* #define DEBUG */ |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 16 | #include <linux/module.h> |
| 17 | #include <linux/fs.h> |
| 18 | #include <linux/mount.h> |
| 19 | #include <linux/pagemap.h> |
| 20 | #include <linux/init.h> |
| 21 | #include <linux/namei.h> |
| 22 | #include <linux/security.h> |
Mimi Zohar | 9256292 | 2008-10-07 14:00:12 -0400 | [diff] [blame] | 23 | #include <linux/magic.h> |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 24 | |
| 25 | static struct vfsmount *mount; |
| 26 | static int mount_count; |
| 27 | |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 28 | static int fill_super(struct super_block *sb, void *data, int silent) |
| 29 | { |
| 30 | static struct tree_descr files[] = {{""}}; |
| 31 | |
| 32 | return simple_fill_super(sb, SECURITYFS_MAGIC, files); |
| 33 | } |
| 34 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 35 | static struct dentry *get_sb(struct file_system_type *fs_type, |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 36 | int flags, const char *dev_name, |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 37 | void *data) |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 38 | { |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 39 | return mount_single(fs_type, flags, data, fill_super); |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 40 | } |
| 41 | |
| 42 | static struct file_system_type fs_type = { |
| 43 | .owner = THIS_MODULE, |
| 44 | .name = "securityfs", |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 45 | .mount = get_sb, |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 46 | .kill_sb = kill_litter_super, |
| 47 | }; |
| 48 | |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 49 | /** |
| 50 | * securityfs_create_file - create a file in the securityfs filesystem |
| 51 | * |
| 52 | * @name: a pointer to a string containing the name of the file to create. |
| 53 | * @mode: the permission that the file should have |
| 54 | * @parent: a pointer to the parent dentry for this file. This should be a |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 55 | * directory dentry if set. If this parameter is %NULL, then the |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 56 | * file will be created in the root of the securityfs filesystem. |
| 57 | * @data: a pointer to something that the caller will want to get to later |
Theodore Ts'o | 8e18e29 | 2006-09-27 01:50:46 -0700 | [diff] [blame] | 58 | * on. The inode.i_private pointer will point to this value on |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 59 | * the open() call. |
| 60 | * @fops: a pointer to a struct file_operations that should be used for |
| 61 | * this file. |
| 62 | * |
| 63 | * This is the basic "create a file" function for securityfs. It allows for a |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 64 | * wide range of flexibility in creating a file, or a directory (if you |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 65 | * want to create a directory, the securityfs_create_dir() function is |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 66 | * recommended to be used instead). |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 67 | * |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 68 | * This function returns a pointer to a dentry if it succeeds. This |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 69 | * pointer must be passed to the securityfs_remove() function when the file is |
| 70 | * to be removed (no automatic cleanup happens if your module is unloaded, |
Serge E. Hallyn | faa3aad | 2009-02-02 15:07:33 -0800 | [diff] [blame] | 71 | * you are responsible here). If an error occurs, the function will return |
Masanari Iida | da3dae5 | 2014-09-09 01:27:23 +0900 | [diff] [blame] | 72 | * the error value (via ERR_PTR). |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 73 | * |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 74 | * If securityfs is not enabled in the kernel, the value %-ENODEV is |
Serge E. Hallyn | faa3aad | 2009-02-02 15:07:33 -0800 | [diff] [blame] | 75 | * returned. |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 76 | */ |
Al Viro | 52ef0c0 | 2011-07-26 04:30:04 -0400 | [diff] [blame] | 77 | struct dentry *securityfs_create_file(const char *name, umode_t mode, |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 78 | struct dentry *parent, void *data, |
Arjan van de Ven | 9c2e08c | 2007-02-12 00:55:37 -0800 | [diff] [blame] | 79 | const struct file_operations *fops) |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 80 | { |
Al Viro | 3e25eb9 | 2012-01-10 10:20:35 -0500 | [diff] [blame] | 81 | struct dentry *dentry; |
| 82 | int is_dir = S_ISDIR(mode); |
| 83 | struct inode *dir, *inode; |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 84 | int error; |
| 85 | |
Al Viro | 3e25eb9 | 2012-01-10 10:20:35 -0500 | [diff] [blame] | 86 | if (!is_dir) { |
| 87 | BUG_ON(!fops); |
| 88 | mode = (mode & S_IALLUGO) | S_IFREG; |
| 89 | } |
| 90 | |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 91 | pr_debug("securityfs: creating file '%s'\n",name); |
| 92 | |
Trond Myklebust | 1f5ce9e | 2006-06-09 09:34:16 -0400 | [diff] [blame] | 93 | error = simple_pin_fs(&fs_type, &mount, &mount_count); |
Al Viro | 3e25eb9 | 2012-01-10 10:20:35 -0500 | [diff] [blame] | 94 | if (error) |
| 95 | return ERR_PTR(error); |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 96 | |
Al Viro | 3e25eb9 | 2012-01-10 10:20:35 -0500 | [diff] [blame] | 97 | if (!parent) |
| 98 | parent = mount->mnt_root; |
| 99 | |
David Howells | ce0b16d | 2015-02-19 10:47:02 +0000 | [diff] [blame] | 100 | dir = d_inode(parent); |
Al Viro | 3e25eb9 | 2012-01-10 10:20:35 -0500 | [diff] [blame] | 101 | |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 102 | inode_lock(dir); |
Al Viro | 3e25eb9 | 2012-01-10 10:20:35 -0500 | [diff] [blame] | 103 | dentry = lookup_one_len(name, parent, strlen(name)); |
| 104 | if (IS_ERR(dentry)) |
| 105 | goto out; |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 106 | |
David Howells | ce0b16d | 2015-02-19 10:47:02 +0000 | [diff] [blame] | 107 | if (d_really_is_positive(dentry)) { |
Al Viro | 3e25eb9 | 2012-01-10 10:20:35 -0500 | [diff] [blame] | 108 | error = -EEXIST; |
| 109 | goto out1; |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 110 | } |
Al Viro | 3e25eb9 | 2012-01-10 10:20:35 -0500 | [diff] [blame] | 111 | |
| 112 | inode = new_inode(dir->i_sb); |
| 113 | if (!inode) { |
| 114 | error = -ENOMEM; |
| 115 | goto out1; |
| 116 | } |
| 117 | |
| 118 | inode->i_ino = get_next_ino(); |
| 119 | inode->i_mode = mode; |
| 120 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 121 | inode->i_private = data; |
| 122 | if (is_dir) { |
| 123 | inode->i_op = &simple_dir_inode_operations; |
| 124 | inode->i_fop = &simple_dir_operations; |
| 125 | inc_nlink(inode); |
| 126 | inc_nlink(dir); |
| 127 | } else { |
| 128 | inode->i_fop = fops; |
| 129 | } |
| 130 | d_instantiate(dentry, inode); |
| 131 | dget(dentry); |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 132 | inode_unlock(dir); |
Al Viro | 3e25eb9 | 2012-01-10 10:20:35 -0500 | [diff] [blame] | 133 | return dentry; |
| 134 | |
| 135 | out1: |
| 136 | dput(dentry); |
| 137 | dentry = ERR_PTR(error); |
| 138 | out: |
Al Viro | 5955102 | 2016-01-22 15:40:57 -0500 | [diff] [blame] | 139 | inode_unlock(dir); |
Al Viro | 3e25eb9 | 2012-01-10 10:20:35 -0500 | [diff] [blame] | 140 | simple_release_fs(&mount, &mount_count); |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 141 | return dentry; |
| 142 | } |
| 143 | EXPORT_SYMBOL_GPL(securityfs_create_file); |
| 144 | |
| 145 | /** |
| 146 | * securityfs_create_dir - create a directory in the securityfs filesystem |
| 147 | * |
| 148 | * @name: a pointer to a string containing the name of the directory to |
| 149 | * create. |
| 150 | * @parent: a pointer to the parent dentry for this file. This should be a |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 151 | * directory dentry if set. If this parameter is %NULL, then the |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 152 | * directory will be created in the root of the securityfs filesystem. |
| 153 | * |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 154 | * This function creates a directory in securityfs with the given @name. |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 155 | * |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 156 | * This function returns a pointer to a dentry if it succeeds. This |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 157 | * pointer must be passed to the securityfs_remove() function when the file is |
| 158 | * to be removed (no automatic cleanup happens if your module is unloaded, |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 159 | * you are responsible here). If an error occurs, %NULL will be returned. |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 160 | * |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 161 | * If securityfs is not enabled in the kernel, the value %-ENODEV is |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 162 | * returned. It is not wise to check for this value, but rather, check for |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 163 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 164 | * code. |
| 165 | */ |
| 166 | struct dentry *securityfs_create_dir(const char *name, struct dentry *parent) |
| 167 | { |
| 168 | return securityfs_create_file(name, |
| 169 | S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, |
| 170 | parent, NULL, NULL); |
| 171 | } |
| 172 | EXPORT_SYMBOL_GPL(securityfs_create_dir); |
| 173 | |
| 174 | /** |
| 175 | * securityfs_remove - removes a file or directory from the securityfs filesystem |
| 176 | * |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 177 | * @dentry: a pointer to a the dentry of the file or directory to be removed. |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 178 | * |
| 179 | * This function removes a file or directory in securityfs that was previously |
| 180 | * created with a call to another securityfs function (like |
| 181 | * securityfs_create_file() or variants thereof.) |
| 182 | * |
| 183 | * This function is required to be called in order for the file to be |
Randy Dunlap | 3f23d81 | 2008-08-17 21:44:22 -0700 | [diff] [blame] | 184 | * removed. No automatic cleanup of files will happen when a module is |
| 185 | * removed; you are responsible here. |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 186 | */ |
| 187 | void securityfs_remove(struct dentry *dentry) |
| 188 | { |
Al Viro | 4093d30 | 2016-05-29 14:54:04 -0400 | [diff] [blame] | 189 | struct inode *dir; |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 190 | |
Eric Paris | d93e4c9 | 2009-05-11 20:47:15 -0400 | [diff] [blame] | 191 | if (!dentry || IS_ERR(dentry)) |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 192 | return; |
| 193 | |
Al Viro | 4093d30 | 2016-05-29 14:54:04 -0400 | [diff] [blame] | 194 | dir = d_inode(dentry->d_parent); |
| 195 | inode_lock(dir); |
Al Viro | dc3f419 | 2015-05-18 10:10:34 -0400 | [diff] [blame] | 196 | if (simple_positive(dentry)) { |
| 197 | if (d_is_dir(dentry)) |
Al Viro | 4093d30 | 2016-05-29 14:54:04 -0400 | [diff] [blame] | 198 | simple_rmdir(dir, dentry); |
Al Viro | dc3f419 | 2015-05-18 10:10:34 -0400 | [diff] [blame] | 199 | else |
Al Viro | 4093d30 | 2016-05-29 14:54:04 -0400 | [diff] [blame] | 200 | simple_unlink(dir, dentry); |
Al Viro | dc3f419 | 2015-05-18 10:10:34 -0400 | [diff] [blame] | 201 | dput(dentry); |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 202 | } |
Al Viro | 4093d30 | 2016-05-29 14:54:04 -0400 | [diff] [blame] | 203 | inode_unlock(dir); |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 204 | simple_release_fs(&mount, &mount_count); |
| 205 | } |
| 206 | EXPORT_SYMBOL_GPL(securityfs_remove); |
| 207 | |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 208 | static int __init securityfs_init(void) |
| 209 | { |
| 210 | int retval; |
| 211 | |
Eric W. Biederman | f9bb488 | 2015-05-13 17:35:41 -0500 | [diff] [blame] | 212 | retval = sysfs_create_mount_point(kernel_kobj, "security"); |
| 213 | if (retval) |
| 214 | return retval; |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 215 | |
| 216 | retval = register_filesystem(&fs_type); |
| 217 | if (retval) |
Eric W. Biederman | f9bb488 | 2015-05-13 17:35:41 -0500 | [diff] [blame] | 218 | sysfs_remove_mount_point(kernel_kobj, "security"); |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 219 | return retval; |
| 220 | } |
| 221 | |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 222 | core_initcall(securityfs_init); |
Greg KH | b67dbf9 | 2005-07-07 14:37:53 -0700 | [diff] [blame] | 223 | MODULE_LICENSE("GPL"); |
| 224 | |