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; |
| 324 | char kname[XATTR_NAME_MAX + 1]; |
| 325 | |
| 326 | if (flags & ~(XATTR_CREATE|XATTR_REPLACE)) |
| 327 | return -EINVAL; |
| 328 | |
| 329 | error = strncpy_from_user(kname, name, sizeof(kname)); |
| 330 | if (error == 0 || error == sizeof(kname)) |
| 331 | error = -ERANGE; |
| 332 | if (error < 0) |
| 333 | return error; |
| 334 | |
| 335 | if (size) { |
| 336 | if (size > XATTR_SIZE_MAX) |
| 337 | return -E2BIG; |
Li Zefan | 3939fcd | 2009-04-08 15:06:12 +0800 | [diff] [blame] | 338 | kvalue = memdup_user(value, size); |
| 339 | if (IS_ERR(kvalue)) |
| 340 | return PTR_ERR(kvalue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | } |
| 342 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 343 | error = vfs_setxattr(d, kname, kvalue, size, flags); |
Jesper Juhl | f99d49a | 2005-11-07 01:01:34 -0800 | [diff] [blame] | 344 | kfree(kvalue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | return error; |
| 346 | } |
| 347 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 348 | SYSCALL_DEFINE5(setxattr, const char __user *, pathname, |
| 349 | const char __user *, name, const void __user *, value, |
| 350 | size_t, size, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 352 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | int error; |
| 354 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 355 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | if (error) |
| 357 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 358 | error = mnt_want_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 359 | if (!error) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 360 | error = setxattr(path.dentry, name, value, size, flags); |
| 361 | mnt_drop_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 362 | } |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 363 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | return error; |
| 365 | } |
| 366 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 367 | SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname, |
| 368 | const char __user *, name, const void __user *, value, |
| 369 | size_t, size, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 371 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | int error; |
| 373 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 374 | error = user_lpath(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | if (error) |
| 376 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 377 | error = mnt_want_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 378 | if (!error) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 379 | error = setxattr(path.dentry, name, value, size, flags); |
| 380 | mnt_drop_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 381 | } |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 382 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | return error; |
| 384 | } |
| 385 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 386 | SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, |
| 387 | const void __user *,value, size_t, size, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | { |
| 389 | struct file *f; |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 390 | struct dentry *dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | int error = -EBADF; |
| 392 | |
| 393 | f = fget(fd); |
| 394 | if (!f) |
| 395 | return error; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 396 | dentry = f->f_path.dentry; |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 397 | audit_inode(NULL, dentry); |
npiggin@suse.de | 96029c4 | 2009-04-26 20:25:55 +1000 | [diff] [blame] | 398 | error = mnt_want_write_file(f); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 399 | if (!error) { |
| 400 | error = setxattr(dentry, name, value, size, flags); |
Al Viro | 2a79f17 | 2011-12-09 08:06:57 -0500 | [diff] [blame] | 401 | mnt_drop_write_file(f); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 402 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | fput(f); |
| 404 | return error; |
| 405 | } |
| 406 | |
| 407 | /* |
| 408 | * Extended attribute GET operations |
| 409 | */ |
| 410 | static ssize_t |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 411 | getxattr(struct dentry *d, const char __user *name, void __user *value, |
| 412 | size_t size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | { |
| 414 | ssize_t error; |
| 415 | void *kvalue = NULL; |
| 416 | char kname[XATTR_NAME_MAX + 1]; |
| 417 | |
| 418 | error = strncpy_from_user(kname, name, sizeof(kname)); |
| 419 | if (error == 0 || error == sizeof(kname)) |
| 420 | error = -ERANGE; |
| 421 | if (error < 0) |
| 422 | return error; |
| 423 | |
| 424 | if (size) { |
| 425 | if (size > XATTR_SIZE_MAX) |
| 426 | size = XATTR_SIZE_MAX; |
James Morris | d381d8a | 2005-10-30 14:59:22 -0800 | [diff] [blame] | 427 | kvalue = kzalloc(size, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | if (!kvalue) |
| 429 | return -ENOMEM; |
| 430 | } |
| 431 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 432 | error = vfs_getxattr(d, kname, kvalue, size); |
Stephen Smalley | f549d6c | 2005-09-03 15:55:18 -0700 | [diff] [blame] | 433 | if (error > 0) { |
| 434 | if (size && copy_to_user(value, kvalue, error)) |
| 435 | error = -EFAULT; |
| 436 | } else if (error == -ERANGE && size >= XATTR_SIZE_MAX) { |
| 437 | /* The file system tried to returned a value bigger |
| 438 | than XATTR_SIZE_MAX bytes. Not possible. */ |
| 439 | error = -E2BIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | } |
Jesper Juhl | f99d49a | 2005-11-07 01:01:34 -0800 | [diff] [blame] | 441 | kfree(kvalue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | return error; |
| 443 | } |
| 444 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 445 | SYSCALL_DEFINE4(getxattr, const char __user *, pathname, |
| 446 | const char __user *, name, void __user *, value, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 448 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | ssize_t error; |
| 450 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 451 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | if (error) |
| 453 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 454 | error = getxattr(path.dentry, name, value, size); |
| 455 | path_put(&path); |
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(lgetxattr, 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_lpath(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(fgetxattr, int, fd, const char __user *, name, |
| 474 | void __user *, value, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | { |
| 476 | struct file *f; |
| 477 | ssize_t error = -EBADF; |
| 478 | |
| 479 | f = fget(fd); |
| 480 | if (!f) |
| 481 | return error; |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 482 | audit_inode(NULL, f->f_path.dentry); |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 483 | error = getxattr(f->f_path.dentry, name, value, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | fput(f); |
| 485 | return error; |
| 486 | } |
| 487 | |
| 488 | /* |
| 489 | * Extended attribute LIST operations |
| 490 | */ |
| 491 | static ssize_t |
| 492 | listxattr(struct dentry *d, char __user *list, size_t size) |
| 493 | { |
| 494 | ssize_t error; |
| 495 | char *klist = NULL; |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame^] | 496 | char *vlist = NULL; /* If non-NULL, we used vmalloc() */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 497 | |
| 498 | if (size) { |
| 499 | if (size > XATTR_LIST_MAX) |
| 500 | size = XATTR_LIST_MAX; |
Dave Jones | 703bf2d | 2012-04-05 14:25:06 -0700 | [diff] [blame] | 501 | klist = kmalloc(size, __GFP_NOWARN | GFP_KERNEL); |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame^] | 502 | if (!klist) { |
| 503 | vlist = vmalloc(size); |
| 504 | if (!vlist) |
| 505 | return -ENOMEM; |
| 506 | klist = vlist; |
| 507 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | } |
| 509 | |
Bill Nottingham | 659564c | 2006-10-09 16:10:48 -0400 | [diff] [blame] | 510 | error = vfs_listxattr(d, klist, size); |
Stephen Smalley | f549d6c | 2005-09-03 15:55:18 -0700 | [diff] [blame] | 511 | if (error > 0) { |
| 512 | if (size && copy_to_user(list, klist, error)) |
| 513 | error = -EFAULT; |
| 514 | } else if (error == -ERANGE && size >= XATTR_LIST_MAX) { |
| 515 | /* The file system tried to returned a list bigger |
| 516 | than XATTR_LIST_MAX bytes. Not possible. */ |
| 517 | error = -E2BIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | } |
Andrew Morton | 0d08d7b | 2012-04-05 14:25:07 -0700 | [diff] [blame^] | 519 | if (vlist) |
| 520 | vfree(vlist); |
| 521 | else |
| 522 | kfree(klist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | return error; |
| 524 | } |
| 525 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 526 | SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list, |
| 527 | size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 529 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | ssize_t error; |
| 531 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 532 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | if (error) |
| 534 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 535 | error = listxattr(path.dentry, list, size); |
| 536 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | return error; |
| 538 | } |
| 539 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 540 | SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list, |
| 541 | size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 543 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | ssize_t error; |
| 545 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 546 | error = user_lpath(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | if (error) |
| 548 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 549 | error = listxattr(path.dentry, list, size); |
| 550 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | return error; |
| 552 | } |
| 553 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 554 | SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | { |
| 556 | struct file *f; |
| 557 | ssize_t error = -EBADF; |
| 558 | |
| 559 | f = fget(fd); |
| 560 | if (!f) |
| 561 | return error; |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 562 | audit_inode(NULL, f->f_path.dentry); |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 563 | error = listxattr(f->f_path.dentry, list, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | fput(f); |
| 565 | return error; |
| 566 | } |
| 567 | |
| 568 | /* |
| 569 | * Extended attribute REMOVE operations |
| 570 | */ |
| 571 | static long |
David Howells | 8f0cfa5 | 2008-04-29 00:59:41 -0700 | [diff] [blame] | 572 | removexattr(struct dentry *d, const char __user *name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | { |
| 574 | int error; |
| 575 | char kname[XATTR_NAME_MAX + 1]; |
| 576 | |
| 577 | error = strncpy_from_user(kname, name, sizeof(kname)); |
| 578 | if (error == 0 || error == sizeof(kname)) |
| 579 | error = -ERANGE; |
| 580 | if (error < 0) |
| 581 | return error; |
| 582 | |
Christoph Hellwig | 5be196e | 2006-01-09 20:51:55 -0800 | [diff] [blame] | 583 | return vfs_removexattr(d, kname); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | } |
| 585 | |
Heiko Carstens | 64fd1de | 2009-01-14 14:14:14 +0100 | [diff] [blame] | 586 | SYSCALL_DEFINE2(removexattr, const char __user *, pathname, |
| 587 | const char __user *, name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 589 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 590 | int error; |
| 591 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 592 | error = user_path(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | if (error) |
| 594 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 595 | error = mnt_want_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 596 | if (!error) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 597 | error = removexattr(path.dentry, name); |
| 598 | mnt_drop_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 599 | } |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 600 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | return error; |
| 602 | } |
| 603 | |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 604 | SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname, |
| 605 | const char __user *, name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 607 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 608 | int error; |
| 609 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 610 | error = user_lpath(pathname, &path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 611 | if (error) |
| 612 | return error; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 613 | error = mnt_want_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 614 | if (!error) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 615 | error = removexattr(path.dentry, name); |
| 616 | mnt_drop_write(path.mnt); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 617 | } |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 618 | path_put(&path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | return error; |
| 620 | } |
| 621 | |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 622 | SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | { |
| 624 | struct file *f; |
Amy Griffis | 73241cc | 2005-11-03 16:00:25 +0000 | [diff] [blame] | 625 | struct dentry *dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 626 | int error = -EBADF; |
| 627 | |
| 628 | f = fget(fd); |
| 629 | if (!f) |
| 630 | return error; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 631 | dentry = f->f_path.dentry; |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 632 | audit_inode(NULL, dentry); |
npiggin@suse.de | 96029c4 | 2009-04-26 20:25:55 +1000 | [diff] [blame] | 633 | error = mnt_want_write_file(f); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 634 | if (!error) { |
| 635 | error = removexattr(dentry, name); |
Al Viro | 2a79f17 | 2011-12-09 08:06:57 -0500 | [diff] [blame] | 636 | mnt_drop_write_file(f); |
Dave Hansen | 18f335a | 2008-02-15 14:37:38 -0800 | [diff] [blame] | 637 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 638 | fput(f); |
| 639 | return error; |
| 640 | } |
| 641 | |
| 642 | |
| 643 | static const char * |
| 644 | strcmp_prefix(const char *a, const char *a_prefix) |
| 645 | { |
| 646 | while (*a_prefix && *a == *a_prefix) { |
| 647 | a++; |
| 648 | a_prefix++; |
| 649 | } |
| 650 | return *a_prefix ? NULL : a; |
| 651 | } |
| 652 | |
| 653 | /* |
| 654 | * In order to implement different sets of xattr operations for each xattr |
| 655 | * prefix with the generic xattr API, a filesystem should create a |
| 656 | * null-terminated array of struct xattr_handler (one for each prefix) and |
| 657 | * hang a pointer to it off of the s_xattr field of the superblock. |
| 658 | * |
| 659 | * The generic_fooxattr() functions will use this list to dispatch xattr |
| 660 | * operations to the correct xattr_handler. |
| 661 | */ |
| 662 | #define for_each_xattr_handler(handlers, handler) \ |
| 663 | for ((handler) = *(handlers)++; \ |
| 664 | (handler) != NULL; \ |
| 665 | (handler) = *(handlers)++) |
| 666 | |
| 667 | /* |
| 668 | * Find the xattr_handler with the matching prefix. |
| 669 | */ |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 670 | static const struct xattr_handler * |
| 671 | xattr_resolve_name(const struct xattr_handler **handlers, const char **name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 672 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 673 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 674 | |
| 675 | if (!*name) |
| 676 | return NULL; |
| 677 | |
| 678 | for_each_xattr_handler(handlers, handler) { |
| 679 | const char *n = strcmp_prefix(*name, handler->prefix); |
| 680 | if (n) { |
| 681 | *name = n; |
| 682 | break; |
| 683 | } |
| 684 | } |
| 685 | return handler; |
| 686 | } |
| 687 | |
| 688 | /* |
| 689 | * Find the handler for the prefix and dispatch its get() operation. |
| 690 | */ |
| 691 | ssize_t |
| 692 | generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size) |
| 693 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 694 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 696 | handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | if (!handler) |
| 698 | return -EOPNOTSUPP; |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 699 | return handler->get(dentry, name, buffer, size, handler->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | } |
| 701 | |
| 702 | /* |
| 703 | * Combine the results of the list() operation from every xattr_handler in the |
| 704 | * list. |
| 705 | */ |
| 706 | ssize_t |
| 707 | generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) |
| 708 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 709 | const struct xattr_handler *handler, **handlers = dentry->d_sb->s_xattr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 710 | unsigned int size = 0; |
| 711 | |
| 712 | if (!buffer) { |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 713 | for_each_xattr_handler(handlers, handler) { |
| 714 | size += handler->list(dentry, NULL, 0, NULL, 0, |
| 715 | handler->flags); |
| 716 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | } else { |
| 718 | char *buf = buffer; |
| 719 | |
| 720 | for_each_xattr_handler(handlers, handler) { |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 721 | size = handler->list(dentry, buf, buffer_size, |
| 722 | NULL, 0, handler->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 723 | if (size > buffer_size) |
| 724 | return -ERANGE; |
| 725 | buf += size; |
| 726 | buffer_size -= size; |
| 727 | } |
| 728 | size = buf - buffer; |
| 729 | } |
| 730 | return size; |
| 731 | } |
| 732 | |
| 733 | /* |
| 734 | * Find the handler for the prefix and dispatch its set() operation. |
| 735 | */ |
| 736 | int |
| 737 | generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) |
| 738 | { |
Stephen Hemminger | bb43545 | 2010-05-13 17:53:14 -0700 | [diff] [blame] | 739 | const struct xattr_handler *handler; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | |
| 741 | if (size == 0) |
| 742 | value = ""; /* empty EA, do not remove */ |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 743 | handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 744 | if (!handler) |
| 745 | return -EOPNOTSUPP; |
Jan Kara | df7e130 | 2011-04-20 20:30:40 +0200 | [diff] [blame] | 746 | return handler->set(dentry, name, value, size, flags, handler->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 747 | } |
| 748 | |
| 749 | /* |
| 750 | * Find the handler for the prefix and dispatch its set() operation to remove |
| 751 | * any associated extended attribute. |
| 752 | */ |
| 753 | int |
| 754 | generic_removexattr(struct dentry *dentry, const char *name) |
| 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 | |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 758 | handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | if (!handler) |
| 760 | return -EOPNOTSUPP; |
Christoph Hellwig | 431547b | 2009-11-13 09:52:56 +0000 | [diff] [blame] | 761 | return handler->set(dentry, name, NULL, 0, |
| 762 | XATTR_REPLACE, handler->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 763 | } |
| 764 | |
| 765 | EXPORT_SYMBOL(generic_getxattr); |
| 766 | EXPORT_SYMBOL(generic_listxattr); |
| 767 | EXPORT_SYMBOL(generic_setxattr); |
| 768 | EXPORT_SYMBOL(generic_removexattr); |