Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | File: fs/xattr.c |
| 3 | |
| 4 | Extended attribute handling. |
| 5 | |
| 6 | Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org> |
| 7 | Copyright (C) 2001 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com> |
| 8 | Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> |
| 9 | */ |
| 10 | #include <linux/fs.h> |
| 11 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include <linux/file.h> |
| 13 | #include <linux/xattr.h> |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 14 | #include <linux/mount.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/namei.h> |
| 16 | #include <linux/security.h> |
Mimi Zohar | c7b87de | 2011-03-09 14:39:18 -0500 | [diff] [blame] | 17 | #include <linux/evm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <linux/syscalls.h> |
Paul Gortmaker | 630d9c4 | 2011-11-16 23:57:37 -0500 | [diff] [blame] | 19 | #include <linux/export.h> |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 20 | #include <linux/fsnotify.h> |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 21 | #include <linux/audit.h> |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 22 | #include <linux/vmalloc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 24 | #include <asm/uaccess.h> |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 25 | |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 26 | /* |
| 27 | * Check permissions for extended attribute access. This is a bit complicated |
| 28 | * because different namespaces have very different rules. |
| 29 | */ |
| 30 | static int |
| 31 | xattr_permission(struct inode *inode, const char *name, int mask) |
| 32 | { |
| 33 | /* |
| 34 | * We can never set or remove an extended attribute on a read-only |
| 35 | * filesystem or on an immutable / append-only inode. |
| 36 | */ |
| 37 | if (mask & MAY_WRITE) { |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 38 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) |
| 39 | return -EPERM; |
| 40 | } |
| 41 | |
| 42 | /* |
| 43 | * No restriction for security.* and system.* from the VFS. Decision |
| 44 | * on these is left to the underlying filesystem / security module. |
| 45 | */ |
| 46 | if (!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) || |
| 47 | !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) |
| 48 | return 0; |
| 49 | |
| 50 | /* |
Andreas Gruenbacher | 55b23bd | 2011-05-27 14:50:36 +0200 | [diff] [blame] | 51 | * The trusted.* namespace can only be accessed by privileged users. |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 52 | */ |
Andreas Gruenbacher | 55b23bd | 2011-05-27 14:50:36 +0200 | [diff] [blame] | 53 | if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) { |
| 54 | if (!capable(CAP_SYS_ADMIN)) |
| 55 | return (mask & MAY_WRITE) ? -EPERM : -ENODATA; |
| 56 | return 0; |
| 57 | } |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 58 | |
Andreas Gruenbacher | 55b23bd | 2011-05-27 14:50:36 +0200 | [diff] [blame] | 59 | /* |
| 60 | * In the user.* namespace, only regular files and directories can have |
Andreas Gruenbacher | f1f2d87 | 2006-11-02 22:07:29 -0800 | [diff] [blame] | 61 | * extended attributes. For sticky directories, only the owner and |
Andreas Gruenbacher | 55b23bd | 2011-05-27 14:50:36 +0200 | [diff] [blame] | 62 | * privileged users can write attributes. |
Andreas Gruenbacher | f1f2d87 | 2006-11-02 22:07:29 -0800 | [diff] [blame] | 63 | */ |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 64 | if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) { |
Andreas Gruenbacher | f1f2d87 | 2006-11-02 22:07:29 -0800 | [diff] [blame] | 65 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) |
Andreas Gruenbacher | 55b23bd | 2011-05-27 14:50:36 +0200 | [diff] [blame] | 66 | return (mask & MAY_WRITE) ? -EPERM : -ENODATA; |
Andreas Gruenbacher | f1f2d87 | 2006-11-02 22:07:29 -0800 | [diff] [blame] | 67 | if (S_ISDIR(inode->i_mode) && (inode->i_mode & S_ISVTX) && |
Serge E. Hallyn | 2e14967 | 2011-03-23 16:43:26 -0700 | [diff] [blame] | 68 | (mask & MAY_WRITE) && !inode_owner_or_capable(inode)) |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 69 | return -EPERM; |
| 70 | } |
| 71 | |
Al Viro | f419a2e | 2008-07-22 00:07:17 -0400 | [diff] [blame] | 72 | return inode_permission(inode, mask); |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 73 | } |
| 74 | |
David P. Quigley | b1ab7e4 | 2009-09-03 14:25:56 -0400 | [diff] [blame] | 75 | /** |
| 76 | * __vfs_setxattr_noperm - perform setxattr operation without performing |
| 77 | * permission checks. |
| 78 | * |
| 79 | * @dentry - object to perform setxattr on |
| 80 | * @name - xattr name to set |
| 81 | * @value - value to set @name to |
| 82 | * @size - size of @value |
| 83 | * @flags - flags to pass into filesystem operations |
| 84 | * |
| 85 | * returns the result of the internal setxattr or setsecurity operations. |
| 86 | * |
| 87 | * This function requires the caller to lock the inode's i_mutex before it |
| 88 | * is executed. It also assumes that the caller will make the appropriate |
| 89 | * permission checks. |
| 90 | */ |
| 91 | int __vfs_setxattr_noperm(struct dentry *dentry, const char *name, |
| 92 | const void *value, size_t size, int flags) |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 93 | { |
| 94 | struct inode *inode = dentry->d_inode; |
David P. Quigley | b1ab7e4 | 2009-09-03 14:25:56 -0400 | [diff] [blame] | 95 | int error = -EOPNOTSUPP; |
Andi Kleen | 69b4573 | 2011-05-28 08:25:51 -0700 | [diff] [blame] | 96 | int issec = !strncmp(name, XATTR_SECURITY_PREFIX, |
| 97 | XATTR_SECURITY_PREFIX_LEN); |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 98 | |
Andi Kleen | 69b4573 | 2011-05-28 08:25:51 -0700 | [diff] [blame] | 99 | if (issec) |
| 100 | inode->i_flags &= ~S_NOSEC; |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 101 | if (inode->i_op->setxattr) { |
| 102 | error = inode->i_op->setxattr(dentry, name, value, size, flags); |
| 103 | if (!error) { |
| 104 | fsnotify_xattr(dentry); |
| 105 | security_inode_post_setxattr(dentry, name, value, |
| 106 | size, flags); |
| 107 | } |
Andi Kleen | 69b4573 | 2011-05-28 08:25:51 -0700 | [diff] [blame] | 108 | } else if (issec) { |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 109 | const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 110 | error = security_inode_setsecurity(inode, suffix, value, |
| 111 | size, flags); |
| 112 | if (!error) |
| 113 | fsnotify_xattr(dentry); |
| 114 | } |
David P. Quigley | b1ab7e4 | 2009-09-03 14:25:56 -0400 | [diff] [blame] | 115 | |
| 116 | return error; |
| 117 | } |
| 118 | |
| 119 | |
| 120 | int |
| 121 | vfs_setxattr(struct dentry *dentry, const char *name, const void *value, |
| 122 | size_t size, int flags) |
| 123 | { |
| 124 | struct inode *inode = dentry->d_inode; |
| 125 | int error; |
| 126 | |
| 127 | error = xattr_permission(inode, name, MAY_WRITE); |
| 128 | if (error) |
| 129 | return error; |
| 130 | |
| 131 | mutex_lock(&inode->i_mutex); |
| 132 | error = security_inode_setxattr(dentry, name, value, size, flags); |
| 133 | if (error) |
| 134 | goto out; |
| 135 | |
| 136 | error = __vfs_setxattr_noperm(dentry, name, value, size, flags); |
| 137 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 138 | out: |
| 139 | mutex_unlock(&inode->i_mutex); |
| 140 | return error; |
| 141 | } |
| 142 | EXPORT_SYMBOL_GPL(vfs_setxattr); |
| 143 | |
| 144 | ssize_t |
David P. Quigley | 4249259 | 2008-02-04 22:29:39 -0800 | [diff] [blame] | 145 | xattr_getsecurity(struct inode *inode, const char *name, void *value, |
| 146 | size_t size) |
| 147 | { |
| 148 | void *buffer = NULL; |
| 149 | ssize_t len; |
| 150 | |
| 151 | if (!value || !size) { |
| 152 | len = security_inode_getsecurity(inode, name, &buffer, false); |
| 153 | goto out_noalloc; |
| 154 | } |
| 155 | |
| 156 | len = security_inode_getsecurity(inode, name, &buffer, true); |
| 157 | if (len < 0) |
| 158 | return len; |
| 159 | if (size < len) { |
| 160 | len = -ERANGE; |
| 161 | goto out; |
| 162 | } |
| 163 | memcpy(value, buffer, len); |
| 164 | out: |
| 165 | security_release_secctx(buffer, len); |
| 166 | out_noalloc: |
| 167 | return len; |
| 168 | } |
| 169 | EXPORT_SYMBOL_GPL(xattr_getsecurity); |
| 170 | |
Mimi Zohar | 1601fba | 2011-03-09 14:23:34 -0500 | [diff] [blame] | 171 | /* |
| 172 | * vfs_getxattr_alloc - allocate memory, if necessary, before calling getxattr |
| 173 | * |
| 174 | * Allocate memory, if not already allocated, or re-allocate correct size, |
| 175 | * before retrieving the extended attribute. |
| 176 | * |
| 177 | * Returns the result of alloc, if failed, or the getxattr operation. |
| 178 | */ |
| 179 | ssize_t |
| 180 | vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value, |
| 181 | size_t xattr_size, gfp_t flags) |
| 182 | { |
| 183 | struct inode *inode = dentry->d_inode; |
| 184 | char *value = *xattr_value; |
| 185 | int error; |
| 186 | |
| 187 | error = xattr_permission(inode, name, MAY_READ); |
| 188 | if (error) |
| 189 | return error; |
| 190 | |
| 191 | if (!inode->i_op->getxattr) |
| 192 | return -EOPNOTSUPP; |
| 193 | |
| 194 | error = inode->i_op->getxattr(dentry, name, NULL, 0); |
| 195 | if (error < 0) |
| 196 | return error; |
| 197 | |
| 198 | if (!value || (error > xattr_size)) { |
| 199 | value = krealloc(*xattr_value, error + 1, flags); |
| 200 | if (!value) |
| 201 | return -ENOMEM; |
| 202 | memset(value, 0, error + 1); |
| 203 | } |
| 204 | |
| 205 | error = inode->i_op->getxattr(dentry, name, value, error); |
| 206 | *xattr_value = value; |
| 207 | return error; |
| 208 | } |
| 209 | |
| 210 | /* Compare an extended attribute value with the given value */ |
| 211 | int vfs_xattr_cmp(struct dentry *dentry, const char *xattr_name, |
| 212 | const char *value, size_t size, gfp_t flags) |
| 213 | { |
| 214 | char *xattr_value = NULL; |
| 215 | int rc; |
| 216 | |
| 217 | rc = vfs_getxattr_alloc(dentry, xattr_name, &xattr_value, 0, flags); |
| 218 | if (rc < 0) |
| 219 | return rc; |
| 220 | |
| 221 | if ((rc != size) || (memcmp(xattr_value, value, rc) != 0)) |
| 222 | rc = -EINVAL; |
| 223 | else |
| 224 | rc = 0; |
| 225 | kfree(xattr_value); |
| 226 | return rc; |
| 227 | } |
| 228 | |
David P. Quigley | 4249259 | 2008-02-04 22:29:39 -0800 | [diff] [blame] | 229 | ssize_t |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 230 | vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size) |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 231 | { |
| 232 | struct inode *inode = dentry->d_inode; |
| 233 | int error; |
| 234 | |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 235 | error = xattr_permission(inode, name, MAY_READ); |
| 236 | if (error) |
| 237 | return error; |
| 238 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 239 | error = security_inode_getxattr(dentry, name); |
| 240 | if (error) |
| 241 | return error; |
| 242 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 243 | if (!strncmp(name, XATTR_SECURITY_PREFIX, |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 244 | XATTR_SECURITY_PREFIX_LEN)) { |
| 245 | const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; |
David P. Quigley | 4249259 | 2008-02-04 22:29:39 -0800 | [diff] [blame] | 246 | int ret = xattr_getsecurity(inode, suffix, value, size); |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 247 | /* |
| 248 | * Only overwrite the return value if a security module |
| 249 | * is actually active. |
| 250 | */ |
David P. Quigley | 4bea580 | 2008-02-04 22:29:40 -0800 | [diff] [blame] | 251 | if (ret == -EOPNOTSUPP) |
| 252 | goto nolsm; |
| 253 | return ret; |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 254 | } |
David P. Quigley | 4bea580 | 2008-02-04 22:29:40 -0800 | [diff] [blame] | 255 | nolsm: |
| 256 | if (inode->i_op->getxattr) |
| 257 | error = inode->i_op->getxattr(dentry, name, value, size); |
| 258 | else |
| 259 | error = -EOPNOTSUPP; |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 260 | |
| 261 | return error; |
| 262 | } |
| 263 | EXPORT_SYMBOL_GPL(vfs_getxattr); |
| 264 | |
Bill Nottingham | 659564c | 2006-10-09 16:10:48 -0400 | [diff] [blame] | 265 | ssize_t |
| 266 | vfs_listxattr(struct dentry *d, char *list, size_t size) |
| 267 | { |
| 268 | ssize_t error; |
| 269 | |
| 270 | error = security_inode_listxattr(d); |
| 271 | if (error) |
| 272 | return error; |
| 273 | error = -EOPNOTSUPP; |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 274 | if (d->d_inode->i_op->listxattr) { |
Bill Nottingham | 659564c | 2006-10-09 16:10:48 -0400 | [diff] [blame] | 275 | error = d->d_inode->i_op->listxattr(d, list, size); |
| 276 | } else { |
| 277 | error = security_inode_listsecurity(d->d_inode, list, size); |
| 278 | if (size && error > size) |
| 279 | error = -ERANGE; |
| 280 | } |
| 281 | return error; |
| 282 | } |
| 283 | EXPORT_SYMBOL_GPL(vfs_listxattr); |
| 284 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 285 | int |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 286 | vfs_removexattr(struct dentry *dentry, const char *name) |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 287 | { |
| 288 | struct inode *inode = dentry->d_inode; |
| 289 | int error; |
| 290 | |
| 291 | if (!inode->i_op->removexattr) |
| 292 | return -EOPNOTSUPP; |
| 293 | |
akpm@osdl.org | e0ad7b0 | 2006-01-09 20:51:56 -0800 | [diff] [blame] | 294 | error = xattr_permission(inode, name, MAY_WRITE); |
| 295 | if (error) |
| 296 | return error; |
| 297 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 298 | error = security_inode_removexattr(dentry, name); |
| 299 | if (error) |
| 300 | return error; |
| 301 | |
| 302 | mutex_lock(&inode->i_mutex); |
| 303 | error = inode->i_op->removexattr(dentry, name); |
| 304 | mutex_unlock(&inode->i_mutex); |
| 305 | |
Mimi Zohar | c7b87de | 2011-03-09 14:39:18 -0500 | [diff] [blame] | 306 | if (!error) { |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 307 | fsnotify_xattr(dentry); |
Mimi Zohar | c7b87de | 2011-03-09 14:39:18 -0500 | [diff] [blame] | 308 | evm_inode_post_removexattr(dentry, name); |
| 309 | } |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 310 | return error; |
| 311 | } |
| 312 | EXPORT_SYMBOL_GPL(vfs_removexattr); |
| 313 | |
| 314 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | /* |
| 316 | * Extended attribute SET operations |
| 317 | */ |
| 318 | static long |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 319 | setxattr(struct dentry *d, const char __user *name, const void __user *value, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | size_t size, int flags) |
| 321 | { |
| 322 | int error; |
| 323 | void *kvalue = NULL; |
Andrew Morton | 44c8249 | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 324 | void *vvalue = NULL; /* If non-NULL, we used vmalloc() */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | char kname[XATTR_NAME_MAX + 1]; |
| 326 | |
| 327 | if (flags & ~(XATTR_CREATE|XATTR_REPLACE)) |
| 328 | return -EINVAL; |
| 329 | |
| 330 | error = strncpy_from_user(kname, name, sizeof(kname)); |
| 331 | if (error == 0 || error == sizeof(kname)) |
| 332 | error = -ERANGE; |
| 333 | if (error < 0) |
| 334 | return error; |
| 335 | |
| 336 | if (size) { |
| 337 | if (size > XATTR_SIZE_MAX) |
| 338 | return -E2BIG; |
Andrew Morton | 44c8249 | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 339 | kvalue = kmalloc(size, GFP_KERNEL | __GFP_NOWARN); |
| 340 | if (!kvalue) { |
| 341 | vvalue = vmalloc(size); |
| 342 | if (!vvalue) |
| 343 | return -ENOMEM; |
| 344 | kvalue = vvalue; |
| 345 | } |
| 346 | if (copy_from_user(kvalue, value, size)) { |
| 347 | error = -EFAULT; |
| 348 | goto out; |
| 349 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | } |
| 351 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 352 | error = vfs_setxattr(d, kname, kvalue, size, flags); |
Andrew Morton | 44c8249 | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 353 | out: |
| 354 | if (vvalue) |
| 355 | vfree(vvalue); |
| 356 | else |
| 357 | kfree(kvalue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | return error; |
| 359 | } |
| 360 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 361 | SYSCALL_DEFINE5(setxattr, const char __user *, pathname, |
| 362 | const char __user *, name, const void __user *, value, |
| 363 | size_t, size, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 365 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | int error; |
| 367 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 368 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | if (error) |
| 370 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 371 | error = mnt_want_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 372 | if (!error) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 373 | error = setxattr(path.dentry, name, value, size, flags); |
| 374 | mnt_drop_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 375 | } |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 376 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | return error; |
| 378 | } |
| 379 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 380 | SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname, |
| 381 | const char __user *, name, const void __user *, value, |
| 382 | size_t, size, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 384 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | int error; |
| 386 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 387 | error = user_lpath(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | if (error) |
| 389 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 390 | error = mnt_want_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 391 | if (!error) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 392 | error = setxattr(path.dentry, name, value, size, flags); |
| 393 | mnt_drop_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 394 | } |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 395 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | return error; |
| 397 | } |
| 398 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 399 | SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, |
| 400 | const void __user *,value, size_t, size, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | { |
Al Viro | 7449af1 | 2012-04-21 18:41:25 -0400 | [diff] [blame] | 402 | int fput_needed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | struct file *f; |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 404 | struct dentry *dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | int error = -EBADF; |
| 406 | |
Al Viro | 7449af1 | 2012-04-21 18:41:25 -0400 | [diff] [blame] | 407 | f = fget_light(fd, &fput_needed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | if (!f) |
| 409 | return error; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 410 | dentry = f->f_path.dentry; |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 411 | audit_inode(NULL, dentry); |
npiggin@suse.de | 96029c4 | 2009-04-26 20:25:55 +1000 | [diff] [blame] | 412 | error = mnt_want_write_file(f); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 413 | if (!error) { |
| 414 | error = setxattr(dentry, name, value, size, flags); |
Al Viro | 2a79f17 | 2011-12-09 08:06:57 -0500 | [diff] [blame] | 415 | mnt_drop_write_file(f); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 416 | } |
Al Viro | 7449af1 | 2012-04-21 18:41:25 -0400 | [diff] [blame] | 417 | fput_light(f, fput_needed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | return error; |
| 419 | } |
| 420 | |
| 421 | /* |
| 422 | * Extended attribute GET operations |
| 423 | */ |
| 424 | static ssize_t |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 425 | getxattr(struct dentry *d, const char __user *name, void __user *value, |
| 426 | size_t size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | { |
| 428 | ssize_t error; |
| 429 | void *kvalue = NULL; |
| 430 | char kname[XATTR_NAME_MAX + 1]; |
| 431 | |
| 432 | error = strncpy_from_user(kname, name, sizeof(kname)); |
| 433 | if (error == 0 || error == sizeof(kname)) |
| 434 | error = -ERANGE; |
| 435 | if (error < 0) |
| 436 | return error; |
| 437 | |
| 438 | if (size) { |
| 439 | if (size > XATTR_SIZE_MAX) |
| 440 | size = XATTR_SIZE_MAX; |
James Morris | d381d8a | 2005-10-30 14:59:22 -0800 | [diff] [blame] | 441 | kvalue = kzalloc(size, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | if (!kvalue) |
| 443 | return -ENOMEM; |
| 444 | } |
| 445 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 446 | error = vfs_getxattr(d, kname, kvalue, size); |
Stephen Smalley | f549d6c | 2005-09-03 15:55:18 -0700 | [diff] [blame] | 447 | if (error > 0) { |
| 448 | if (size && copy_to_user(value, kvalue, error)) |
| 449 | error = -EFAULT; |
| 450 | } else if (error == -ERANGE && size >= XATTR_SIZE_MAX) { |
| 451 | /* The file system tried to returned a value bigger |
| 452 | than XATTR_SIZE_MAX bytes. Not possible. */ |
| 453 | error = -E2BIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | } |
Jesper Juhl | f99d49a | 2005-11-07 01:01:34 -0800 | [diff] [blame] | 455 | kfree(kvalue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | return error; |
| 457 | } |
| 458 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 459 | SYSCALL_DEFINE4(getxattr, const char __user *, pathname, |
| 460 | const char __user *, name, void __user *, value, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 462 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | ssize_t error; |
| 464 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 465 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | if (error) |
| 467 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 468 | error = getxattr(path.dentry, name, value, size); |
| 469 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | return error; |
| 471 | } |
| 472 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 473 | SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname, |
| 474 | const char __user *, name, void __user *, value, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 476 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | ssize_t error; |
| 478 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 479 | error = user_lpath(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 480 | if (error) |
| 481 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 482 | error = getxattr(path.dentry, name, value, size); |
| 483 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | return error; |
| 485 | } |
| 486 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 487 | SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name, |
| 488 | void __user *, value, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 489 | { |
Al Viro | 7449af1 | 2012-04-21 18:41:25 -0400 | [diff] [blame] | 490 | int fput_needed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | struct file *f; |
| 492 | ssize_t error = -EBADF; |
| 493 | |
Al Viro | 7449af1 | 2012-04-21 18:41:25 -0400 | [diff] [blame] | 494 | f = fget_light(fd, &fput_needed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | if (!f) |
| 496 | return error; |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 497 | audit_inode(NULL, f->f_path.dentry); |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 498 | error = getxattr(f->f_path.dentry, name, value, size); |
Al Viro | 7449af1 | 2012-04-21 18:41:25 -0400 | [diff] [blame] | 499 | fput_light(f, fput_needed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | return error; |
| 501 | } |
| 502 | |
| 503 | /* |
| 504 | * Extended attribute LIST operations |
| 505 | */ |
| 506 | static ssize_t |
| 507 | listxattr(struct dentry *d, char __user *list, size_t size) |
| 508 | { |
| 509 | ssize_t error; |
| 510 | char *klist = NULL; |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 511 | char *vlist = NULL; /* If non-NULL, we used vmalloc() */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | |
| 513 | if (size) { |
| 514 | if (size > XATTR_LIST_MAX) |
| 515 | size = XATTR_LIST_MAX; |
Dave Jones | 703bf2d | 2012-04-05 14:25:06 -0700 | [diff] [blame] | 516 | klist = kmalloc(size, __GFP_NOWARN | GFP_KERNEL); |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 517 | if (!klist) { |
| 518 | vlist = vmalloc(size); |
| 519 | if (!vlist) |
| 520 | return -ENOMEM; |
| 521 | klist = vlist; |
| 522 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | } |
| 524 | |
Bill Nottingham | 659564c | 2006-10-09 16:10:48 -0400 | [diff] [blame] | 525 | error = vfs_listxattr(d, klist, size); |
Stephen Smalley | f549d6c | 2005-09-03 15:55:18 -0700 | [diff] [blame] | 526 | if (error > 0) { |
| 527 | if (size && copy_to_user(list, klist, error)) |
| 528 | error = -EFAULT; |
| 529 | } else if (error == -ERANGE && size >= XATTR_LIST_MAX) { |
| 530 | /* The file system tried to returned a list bigger |
| 531 | than XATTR_LIST_MAX bytes. Not possible. */ |
| 532 | error = -E2BIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | } |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame] | 534 | if (vlist) |
| 535 | vfree(vlist); |
| 536 | else |
| 537 | kfree(klist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | return error; |
| 539 | } |
| 540 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 541 | SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list, |
| 542 | size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 544 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | ssize_t error; |
| 546 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 547 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | if (error) |
| 549 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 550 | error = listxattr(path.dentry, list, size); |
| 551 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 552 | return error; |
| 553 | } |
| 554 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 555 | SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list, |
| 556 | size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 558 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | ssize_t error; |
| 560 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 561 | error = user_lpath(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | if (error) |
| 563 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 564 | error = listxattr(path.dentry, list, size); |
| 565 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | return error; |
| 567 | } |
| 568 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 569 | SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | { |
Al Viro | 7449af1 | 2012-04-21 18:41:25 -0400 | [diff] [blame] | 571 | int fput_needed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | struct file *f; |
| 573 | ssize_t error = -EBADF; |
| 574 | |
Al Viro | 7449af1 | 2012-04-21 18:41:25 -0400 | [diff] [blame] | 575 | f = fget_light(fd, &fput_needed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | if (!f) |
| 577 | return error; |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 578 | audit_inode(NULL, f->f_path.dentry); |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 579 | error = listxattr(f->f_path.dentry, list, size); |
Al Viro | 7449af1 | 2012-04-21 18:41:25 -0400 | [diff] [blame] | 580 | fput_light(f, fput_needed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | return error; |
| 582 | } |
| 583 | |
| 584 | /* |
| 585 | * Extended attribute REMOVE operations |
| 586 | */ |
| 587 | static long |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 588 | removexattr(struct dentry *d, const char __user *name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 589 | { |
| 590 | int error; |
| 591 | char kname[XATTR_NAME_MAX + 1]; |
| 592 | |
| 593 | error = strncpy_from_user(kname, name, sizeof(kname)); |
| 594 | if (error == 0 || error == sizeof(kname)) |
| 595 | error = -ERANGE; |
| 596 | if (error < 0) |
| 597 | return error; |
| 598 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 599 | return vfs_removexattr(d, kname); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | } |
| 601 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 602 | SYSCALL_DEFINE2(removexattr, const char __user *, pathname, |
| 603 | const char __user *, name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 604 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 605 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | int error; |
| 607 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 608 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 609 | if (error) |
| 610 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 611 | error = mnt_want_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 612 | if (!error) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 613 | error = removexattr(path.dentry, name); |
| 614 | mnt_drop_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 615 | } |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 616 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | return error; |
| 618 | } |
| 619 | |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 620 | SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname, |
| 621 | const char __user *, name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 622 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 623 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 624 | int error; |
| 625 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 626 | error = user_lpath(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | if (error) |
| 628 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 629 | error = mnt_want_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 630 | if (!error) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 631 | error = removexattr(path.dentry, name); |
| 632 | mnt_drop_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 633 | } |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 634 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 635 | return error; |
| 636 | } |
| 637 | |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 638 | SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | { |
Al Viro | 7449af1 | 2012-04-21 18:41:25 -0400 | [diff] [blame] | 640 | int fput_needed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 641 | struct file *f; |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 642 | struct dentry *dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 643 | int error = -EBADF; |
| 644 | |
Al Viro | 7449af1 | 2012-04-21 18:41:25 -0400 | [diff] [blame] | 645 | f = fget_light(fd, &fput_needed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 646 | if (!f) |
| 647 | return error; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 648 | dentry = f->f_path.dentry; |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 649 | audit_inode(NULL, dentry); |
npiggin@suse.de | 96029c4 | 2009-04-26 20:25:55 +1000 | [diff] [blame] | 650 | error = mnt_want_write_file(f); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 651 | if (!error) { |
| 652 | error = removexattr(dentry, name); |
Al Viro | 2a79f17 | 2011-12-09 08:06:57 -0500 | [diff] [blame] | 653 | mnt_drop_write_file(f); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 654 | } |
Al Viro | 7449af1 | 2012-04-21 18:41:25 -0400 | [diff] [blame] | 655 | fput_light(f, fput_needed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | return error; |
| 657 | } |
| 658 | |
| 659 | |
| 660 | static const char * |
| 661 | strcmp_prefix(const char *a, const char *a_prefix) |
| 662 | { |
| 663 | while (*a_prefix && *a == *a_prefix) { |
| 664 | a++; |
| 665 | a_prefix++; |
| 666 | } |
| 667 | return *a_prefix ? NULL : a; |
| 668 | } |
| 669 | |
| 670 | /* |
| 671 | * In order to implement different sets of xattr operations for each xattr |
| 672 | * prefix with the generic xattr API, a filesystem should create a |
| 673 | * null-terminated array of struct xattr_handler (one for each prefix) and |
| 674 | * hang a pointer to it off of the s_xattr field of the superblock. |
| 675 | * |
| 676 | * The generic_fooxattr() functions will use this list to dispatch xattr |
| 677 | * operations to the correct xattr_handler. |
| 678 | */ |
| 679 | #define for_each_xattr_handler(handlers, handler) \ |
| 680 | for ((handler) = *(handlers)++; \ |
| 681 | (handler) != NULL; \ |
| 682 | (handler) = *(handlers)++) |
| 683 | |
| 684 | /* |
| 685 | * Find the xattr_handler with the matching prefix. |
| 686 | */ |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 687 | static const struct xattr_handler * |
| 688 | xattr_resolve_name(const struct xattr_handler **handlers, const char **name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 690 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | |
| 692 | if (!*name) |
| 693 | return NULL; |
| 694 | |
| 695 | for_each_xattr_handler(handlers, handler) { |
| 696 | const char *n = strcmp_prefix(*name, handler->prefix); |
| 697 | if (n) { |
| 698 | *name = n; |
| 699 | break; |
| 700 | } |
| 701 | } |
| 702 | return handler; |
| 703 | } |
| 704 | |
| 705 | /* |
| 706 | * Find the handler for the prefix and dispatch its get() operation. |
| 707 | */ |
| 708 | ssize_t |
| 709 | generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size) |
| 710 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 711 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 713 | handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 714 | if (!handler) |
| 715 | return -EOPNOTSUPP; |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 716 | return handler->get(dentry, name, buffer, size, handler->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | } |
| 718 | |
| 719 | /* |
| 720 | * Combine the results of the list() operation from every xattr_handler in the |
| 721 | * list. |
| 722 | */ |
| 723 | ssize_t |
| 724 | generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) |
| 725 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 726 | const struct xattr_handler *handler, **handlers = dentry->d_sb->s_xattr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 727 | unsigned int size = 0; |
| 728 | |
| 729 | if (!buffer) { |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 730 | for_each_xattr_handler(handlers, handler) { |
| 731 | size += handler->list(dentry, NULL, 0, NULL, 0, |
| 732 | handler->flags); |
| 733 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | } else { |
| 735 | char *buf = buffer; |
| 736 | |
| 737 | for_each_xattr_handler(handlers, handler) { |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 738 | size = handler->list(dentry, buf, buffer_size, |
| 739 | NULL, 0, handler->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | if (size > buffer_size) |
| 741 | return -ERANGE; |
| 742 | buf += size; |
| 743 | buffer_size -= size; |
| 744 | } |
| 745 | size = buf - buffer; |
| 746 | } |
| 747 | return size; |
| 748 | } |
| 749 | |
| 750 | /* |
| 751 | * Find the handler for the prefix and dispatch its set() operation. |
| 752 | */ |
| 753 | int |
| 754 | generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) |
| 755 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 756 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | |
| 758 | if (size == 0) |
| 759 | value = ""; /* empty EA, do not remove */ |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 760 | handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 761 | if (!handler) |
| 762 | return -EOPNOTSUPP; |
Jan Kara | df7e130 | 2011-04-20 20:30:40 +0200 | [diff] [blame] | 763 | return handler->set(dentry, name, value, size, flags, handler->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | } |
| 765 | |
| 766 | /* |
| 767 | * Find the handler for the prefix and dispatch its set() operation to remove |
| 768 | * any associated extended attribute. |
| 769 | */ |
| 770 | int |
| 771 | generic_removexattr(struct dentry *dentry, const char *name) |
| 772 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 773 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 774 | |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 775 | handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 776 | if (!handler) |
| 777 | return -EOPNOTSUPP; |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 778 | return handler->set(dentry, name, NULL, 0, |
| 779 | XATTR_REPLACE, handler->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | } |
| 781 | |
| 782 | EXPORT_SYMBOL(generic_getxattr); |
| 783 | EXPORT_SYMBOL(generic_listxattr); |
| 784 | EXPORT_SYMBOL(generic_setxattr); |
| 785 | EXPORT_SYMBOL(generic_removexattr); |