Lachlan McIlroy | f9e09f0 | 2008-06-23 13:34:09 +1000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 Christoph Hellwig. |
| 3 | * Portions Copyright (C) 2000-2008 Silicon Graphics, Inc. |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU General Public License as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it would be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write the Free Software Foundation, |
| 16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 17 | */ |
| 18 | |
| 19 | #include "xfs.h" |
| 20 | #include "xfs_da_btree.h" |
| 21 | #include "xfs_bmap_btree.h" |
| 22 | #include "xfs_inode.h" |
| 23 | #include "xfs_attr.h" |
| 24 | #include "xfs_attr_leaf.h" |
| 25 | #include "xfs_acl.h" |
| 26 | #include "xfs_vnodeops.h" |
| 27 | |
| 28 | #include <linux/posix_acl_xattr.h> |
| 29 | #include <linux/xattr.h> |
| 30 | |
| 31 | |
| 32 | /* |
| 33 | * ACL handling. Should eventually be moved into xfs_acl.c |
| 34 | */ |
| 35 | |
| 36 | static int |
| 37 | xfs_decode_acl(const char *name) |
| 38 | { |
| 39 | if (strcmp(name, "posix_acl_access") == 0) |
| 40 | return _ACL_TYPE_ACCESS; |
| 41 | else if (strcmp(name, "posix_acl_default") == 0) |
| 42 | return _ACL_TYPE_DEFAULT; |
| 43 | return -EINVAL; |
| 44 | } |
| 45 | |
| 46 | /* |
| 47 | * Get system extended attributes which at the moment only |
| 48 | * includes Posix ACLs. |
| 49 | */ |
| 50 | static int |
| 51 | xfs_xattr_system_get(struct inode *inode, const char *name, |
| 52 | void *buffer, size_t size) |
| 53 | { |
| 54 | int acl; |
| 55 | |
| 56 | acl = xfs_decode_acl(name); |
| 57 | if (acl < 0) |
| 58 | return acl; |
| 59 | |
| 60 | return xfs_acl_vget(inode, buffer, size, acl); |
| 61 | } |
| 62 | |
| 63 | static int |
| 64 | xfs_xattr_system_set(struct inode *inode, const char *name, |
| 65 | const void *value, size_t size, int flags) |
| 66 | { |
Christoph Hellwig | f13fae2 | 2008-07-21 16:16:15 +1000 | [diff] [blame^] | 67 | int acl; |
Lachlan McIlroy | f9e09f0 | 2008-06-23 13:34:09 +1000 | [diff] [blame] | 68 | |
| 69 | acl = xfs_decode_acl(name); |
| 70 | if (acl < 0) |
| 71 | return acl; |
| 72 | if (flags & XATTR_CREATE) |
| 73 | return -EINVAL; |
| 74 | |
| 75 | if (!value) |
| 76 | return xfs_acl_vremove(inode, acl); |
| 77 | |
Christoph Hellwig | f13fae2 | 2008-07-21 16:16:15 +1000 | [diff] [blame^] | 78 | return xfs_acl_vset(inode, (void *)value, size, acl); |
Lachlan McIlroy | f9e09f0 | 2008-06-23 13:34:09 +1000 | [diff] [blame] | 79 | } |
| 80 | |
| 81 | static struct xattr_handler xfs_xattr_system_handler = { |
| 82 | .prefix = XATTR_SYSTEM_PREFIX, |
| 83 | .get = xfs_xattr_system_get, |
| 84 | .set = xfs_xattr_system_set, |
| 85 | }; |
| 86 | |
| 87 | |
| 88 | /* |
| 89 | * Real xattr handling. The only difference between the namespaces is |
| 90 | * a flag passed to the low-level attr code. |
| 91 | */ |
| 92 | |
| 93 | static int |
| 94 | __xfs_xattr_get(struct inode *inode, const char *name, |
| 95 | void *value, size_t size, int xflags) |
| 96 | { |
| 97 | struct xfs_inode *ip = XFS_I(inode); |
| 98 | int error, asize = size; |
| 99 | |
| 100 | if (strcmp(name, "") == 0) |
| 101 | return -EINVAL; |
| 102 | |
| 103 | /* Convert Linux syscall to XFS internal ATTR flags */ |
| 104 | if (!size) { |
| 105 | xflags |= ATTR_KERNOVAL; |
| 106 | value = NULL; |
| 107 | } |
| 108 | |
| 109 | error = -xfs_attr_get(ip, name, value, &asize, xflags); |
| 110 | if (error) |
| 111 | return error; |
| 112 | return asize; |
| 113 | } |
| 114 | |
| 115 | static int |
| 116 | __xfs_xattr_set(struct inode *inode, const char *name, const void *value, |
| 117 | size_t size, int flags, int xflags) |
| 118 | { |
| 119 | struct xfs_inode *ip = XFS_I(inode); |
| 120 | |
| 121 | if (strcmp(name, "") == 0) |
| 122 | return -EINVAL; |
| 123 | |
| 124 | /* Convert Linux syscall to XFS internal ATTR flags */ |
| 125 | if (flags & XATTR_CREATE) |
| 126 | xflags |= ATTR_CREATE; |
| 127 | if (flags & XATTR_REPLACE) |
| 128 | xflags |= ATTR_REPLACE; |
| 129 | |
| 130 | if (!value) |
| 131 | return -xfs_attr_remove(ip, name, xflags); |
| 132 | return -xfs_attr_set(ip, name, (void *)value, size, xflags); |
| 133 | } |
| 134 | |
| 135 | static int |
| 136 | xfs_xattr_user_get(struct inode *inode, const char *name, |
| 137 | void *value, size_t size) |
| 138 | { |
| 139 | return __xfs_xattr_get(inode, name, value, size, 0); |
| 140 | } |
| 141 | |
| 142 | static int |
| 143 | xfs_xattr_user_set(struct inode *inode, const char *name, |
| 144 | const void *value, size_t size, int flags) |
| 145 | { |
| 146 | return __xfs_xattr_set(inode, name, value, size, flags, 0); |
| 147 | } |
| 148 | |
| 149 | static struct xattr_handler xfs_xattr_user_handler = { |
| 150 | .prefix = XATTR_USER_PREFIX, |
| 151 | .get = xfs_xattr_user_get, |
| 152 | .set = xfs_xattr_user_set, |
| 153 | }; |
| 154 | |
| 155 | |
| 156 | static int |
| 157 | xfs_xattr_trusted_get(struct inode *inode, const char *name, |
| 158 | void *value, size_t size) |
| 159 | { |
| 160 | return __xfs_xattr_get(inode, name, value, size, ATTR_ROOT); |
| 161 | } |
| 162 | |
| 163 | static int |
| 164 | xfs_xattr_trusted_set(struct inode *inode, const char *name, |
| 165 | const void *value, size_t size, int flags) |
| 166 | { |
| 167 | return __xfs_xattr_set(inode, name, value, size, flags, ATTR_ROOT); |
| 168 | } |
| 169 | |
| 170 | static struct xattr_handler xfs_xattr_trusted_handler = { |
| 171 | .prefix = XATTR_TRUSTED_PREFIX, |
| 172 | .get = xfs_xattr_trusted_get, |
| 173 | .set = xfs_xattr_trusted_set, |
| 174 | }; |
| 175 | |
| 176 | |
| 177 | static int |
| 178 | xfs_xattr_secure_get(struct inode *inode, const char *name, |
| 179 | void *value, size_t size) |
| 180 | { |
| 181 | return __xfs_xattr_get(inode, name, value, size, ATTR_SECURE); |
| 182 | } |
| 183 | |
| 184 | static int |
| 185 | xfs_xattr_secure_set(struct inode *inode, const char *name, |
| 186 | const void *value, size_t size, int flags) |
| 187 | { |
| 188 | return __xfs_xattr_set(inode, name, value, size, flags, ATTR_SECURE); |
| 189 | } |
| 190 | |
| 191 | static struct xattr_handler xfs_xattr_security_handler = { |
| 192 | .prefix = XATTR_SECURITY_PREFIX, |
| 193 | .get = xfs_xattr_secure_get, |
| 194 | .set = xfs_xattr_secure_set, |
| 195 | }; |
| 196 | |
| 197 | |
| 198 | struct xattr_handler *xfs_xattr_handlers[] = { |
| 199 | &xfs_xattr_user_handler, |
| 200 | &xfs_xattr_trusted_handler, |
| 201 | &xfs_xattr_security_handler, |
| 202 | &xfs_xattr_system_handler, |
| 203 | NULL |
| 204 | }; |
| 205 | |
| 206 | static unsigned int xfs_xattr_prefix_len(int flags) |
| 207 | { |
| 208 | if (flags & XFS_ATTR_SECURE) |
| 209 | return sizeof("security"); |
| 210 | else if (flags & XFS_ATTR_ROOT) |
| 211 | return sizeof("trusted"); |
| 212 | else |
| 213 | return sizeof("user"); |
| 214 | } |
| 215 | |
| 216 | static const char *xfs_xattr_prefix(int flags) |
| 217 | { |
| 218 | if (flags & XFS_ATTR_SECURE) |
| 219 | return xfs_xattr_security_handler.prefix; |
| 220 | else if (flags & XFS_ATTR_ROOT) |
| 221 | return xfs_xattr_trusted_handler.prefix; |
| 222 | else |
| 223 | return xfs_xattr_user_handler.prefix; |
| 224 | } |
| 225 | |
| 226 | static int |
| 227 | xfs_xattr_put_listent(struct xfs_attr_list_context *context, int flags, |
| 228 | char *name, int namelen, int valuelen, char *value) |
| 229 | { |
| 230 | unsigned int prefix_len = xfs_xattr_prefix_len(flags); |
| 231 | char *offset; |
| 232 | int arraytop; |
| 233 | |
| 234 | ASSERT(context->count >= 0); |
| 235 | |
| 236 | /* |
| 237 | * Only show root namespace entries if we are actually allowed to |
| 238 | * see them. |
| 239 | */ |
| 240 | if ((flags & XFS_ATTR_ROOT) && !capable(CAP_SYS_ADMIN)) |
| 241 | return 0; |
| 242 | |
| 243 | arraytop = context->count + prefix_len + namelen + 1; |
| 244 | if (arraytop > context->firstu) { |
| 245 | context->count = -1; /* insufficient space */ |
| 246 | return 1; |
| 247 | } |
| 248 | offset = (char *)context->alist + context->count; |
| 249 | strncpy(offset, xfs_xattr_prefix(flags), prefix_len); |
| 250 | offset += prefix_len; |
| 251 | strncpy(offset, name, namelen); /* real name */ |
| 252 | offset += namelen; |
| 253 | *offset = '\0'; |
| 254 | context->count += prefix_len + namelen + 1; |
| 255 | return 0; |
| 256 | } |
| 257 | |
| 258 | static int |
| 259 | xfs_xattr_put_listent_sizes(struct xfs_attr_list_context *context, int flags, |
| 260 | char *name, int namelen, int valuelen, char *value) |
| 261 | { |
| 262 | context->count += xfs_xattr_prefix_len(flags) + namelen + 1; |
| 263 | return 0; |
| 264 | } |
| 265 | |
| 266 | static int |
| 267 | list_one_attr(const char *name, const size_t len, void *data, |
| 268 | size_t size, ssize_t *result) |
| 269 | { |
| 270 | char *p = data + *result; |
| 271 | |
| 272 | *result += len; |
| 273 | if (!size) |
| 274 | return 0; |
| 275 | if (*result > size) |
| 276 | return -ERANGE; |
| 277 | |
| 278 | strcpy(p, name); |
| 279 | return 0; |
| 280 | } |
| 281 | |
| 282 | ssize_t |
| 283 | xfs_vn_listxattr(struct dentry *dentry, char *data, size_t size) |
| 284 | { |
| 285 | struct xfs_attr_list_context context; |
| 286 | struct attrlist_cursor_kern cursor = { 0 }; |
| 287 | struct inode *inode = dentry->d_inode; |
| 288 | int error; |
| 289 | |
| 290 | /* |
| 291 | * First read the regular on-disk attributes. |
| 292 | */ |
| 293 | memset(&context, 0, sizeof(context)); |
| 294 | context.dp = XFS_I(inode); |
| 295 | context.cursor = &cursor; |
| 296 | context.resynch = 1; |
| 297 | context.alist = data; |
| 298 | context.bufsize = size; |
| 299 | context.firstu = context.bufsize; |
| 300 | |
| 301 | if (size) |
| 302 | context.put_listent = xfs_xattr_put_listent; |
| 303 | else |
| 304 | context.put_listent = xfs_xattr_put_listent_sizes; |
| 305 | |
| 306 | xfs_attr_list_int(&context); |
| 307 | if (context.count < 0) |
| 308 | return -ERANGE; |
| 309 | |
| 310 | /* |
| 311 | * Then add the two synthetic ACL attributes. |
| 312 | */ |
| 313 | if (xfs_acl_vhasacl_access(inode)) { |
| 314 | error = list_one_attr(POSIX_ACL_XATTR_ACCESS, |
| 315 | strlen(POSIX_ACL_XATTR_ACCESS) + 1, |
| 316 | data, size, &context.count); |
| 317 | if (error) |
| 318 | return error; |
| 319 | } |
| 320 | |
| 321 | if (xfs_acl_vhasacl_default(inode)) { |
| 322 | error = list_one_attr(POSIX_ACL_XATTR_DEFAULT, |
| 323 | strlen(POSIX_ACL_XATTR_DEFAULT) + 1, |
| 324 | data, size, &context.count); |
| 325 | if (error) |
| 326 | return error; |
| 327 | } |
| 328 | |
| 329 | return context.count; |
| 330 | } |