1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * fs/f2fs/acl.c 4 * 5 * Copyright (c) 2012 Samsung Electronics Co., Ltd. 6 * http://www.samsung.com/ 7 * 8 * Portions of this code from linux/fs/ext2/acl.c 9 * 10 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> 11 */ 12 #include <linux/f2fs_fs.h> 13 #include "f2fs.h" 14 #include "xattr.h" 15 #include "acl.h" 16 17 static inline size_t f2fs_acl_size(int count) 18 { 19 if (count <= 4) { 20 return sizeof(struct f2fs_acl_header) + 21 count * sizeof(struct f2fs_acl_entry_short); 22 } else { 23 return sizeof(struct f2fs_acl_header) + 24 4 * sizeof(struct f2fs_acl_entry_short) + 25 (count - 4) * sizeof(struct f2fs_acl_entry); 26 } 27 } 28 29 static inline int f2fs_acl_count(size_t size) 30 { 31 ssize_t s; 32 33 size -= sizeof(struct f2fs_acl_header); 34 s = size - 4 * sizeof(struct f2fs_acl_entry_short); 35 if (s < 0) { 36 if (size % sizeof(struct f2fs_acl_entry_short)) 37 return -1; 38 return size / sizeof(struct f2fs_acl_entry_short); 39 } else { 40 if (s % sizeof(struct f2fs_acl_entry)) 41 return -1; 42 return s / sizeof(struct f2fs_acl_entry) + 4; 43 } 44 } 45 46 static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size) 47 { 48 int i, count; 49 struct posix_acl *acl; 50 struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value; 51 struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1); 52 const char *end = value + size; 53 54 if (size < sizeof(struct f2fs_acl_header)) 55 return ERR_PTR(-EINVAL); 56 57 if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION)) 58 return ERR_PTR(-EINVAL); 59 60 count = f2fs_acl_count(size); 61 if (count < 0) 62 return ERR_PTR(-EINVAL); 63 if (count == 0) 64 return NULL; 65 66 acl = posix_acl_alloc(count, GFP_NOFS); 67 if (!acl) 68 return ERR_PTR(-ENOMEM); 69 70 for (i = 0; i < count; i++) { 71 72 if ((char *)entry > end) 73 goto fail; 74 75 acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag); 76 acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm); 77 78 switch (acl->a_entries[i].e_tag) { 79 case ACL_USER_OBJ: 80 case ACL_GROUP_OBJ: 81 case ACL_MASK: 82 case ACL_OTHER: 83 entry = (struct f2fs_acl_entry *)((char *)entry + 84 sizeof(struct f2fs_acl_entry_short)); 85 break; 86 87 case ACL_USER: 88 acl->a_entries[i].e_uid = 89 make_kuid(&init_user_ns, 90 le32_to_cpu(entry->e_id)); 91 entry = (struct f2fs_acl_entry *)((char *)entry + 92 sizeof(struct f2fs_acl_entry)); 93 break; 94 case ACL_GROUP: 95 acl->a_entries[i].e_gid = 96 make_kgid(&init_user_ns, 97 le32_to_cpu(entry->e_id)); 98 entry = (struct f2fs_acl_entry *)((char *)entry + 99 sizeof(struct f2fs_acl_entry)); 100 break; 101 default: 102 goto fail; 103 } 104 } 105 if ((char *)entry != end) 106 goto fail; 107 return acl; 108 fail: 109 posix_acl_release(acl); 110 return ERR_PTR(-EINVAL); 111 } 112 113 static void *f2fs_acl_to_disk(struct f2fs_sb_info *sbi, 114 const struct posix_acl *acl, size_t *size) 115 { 116 struct f2fs_acl_header *f2fs_acl; 117 struct f2fs_acl_entry *entry; 118 int i; 119 120 f2fs_acl = f2fs_kmalloc(sbi, sizeof(struct f2fs_acl_header) + 121 acl->a_count * sizeof(struct f2fs_acl_entry), 122 GFP_NOFS); 123 if (!f2fs_acl) 124 return ERR_PTR(-ENOMEM); 125 126 f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION); 127 entry = (struct f2fs_acl_entry *)(f2fs_acl + 1); 128 129 for (i = 0; i < acl->a_count; i++) { 130 131 entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag); 132 entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm); 133 134 switch (acl->a_entries[i].e_tag) { 135 case ACL_USER: 136 entry->e_id = cpu_to_le32( 137 from_kuid(&init_user_ns, 138 acl->a_entries[i].e_uid)); 139 entry = (struct f2fs_acl_entry *)((char *)entry + 140 sizeof(struct f2fs_acl_entry)); 141 break; 142 case ACL_GROUP: 143 entry->e_id = cpu_to_le32( 144 from_kgid(&init_user_ns, 145 acl->a_entries[i].e_gid)); 146 entry = (struct f2fs_acl_entry *)((char *)entry + 147 sizeof(struct f2fs_acl_entry)); 148 break; 149 case ACL_USER_OBJ: 150 case ACL_GROUP_OBJ: 151 case ACL_MASK: 152 case ACL_OTHER: 153 entry = (struct f2fs_acl_entry *)((char *)entry + 154 sizeof(struct f2fs_acl_entry_short)); 155 break; 156 default: 157 goto fail; 158 } 159 } 160 *size = f2fs_acl_size(acl->a_count); 161 return (void *)f2fs_acl; 162 163 fail: 164 kfree(f2fs_acl); 165 return ERR_PTR(-EINVAL); 166 } 167 168 static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type, 169 struct page *dpage) 170 { 171 int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; 172 void *value = NULL; 173 struct posix_acl *acl; 174 int retval; 175 176 if (type == ACL_TYPE_ACCESS) 177 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; 178 179 retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage); 180 if (retval > 0) { 181 value = f2fs_kmalloc(F2FS_I_SB(inode), retval, GFP_F2FS_ZERO); 182 if (!value) 183 return ERR_PTR(-ENOMEM); 184 retval = f2fs_getxattr(inode, name_index, "", value, 185 retval, dpage); 186 } 187 188 if (retval > 0) 189 acl = f2fs_acl_from_disk(value, retval); 190 else if (retval == -ENODATA) 191 acl = NULL; 192 else 193 acl = ERR_PTR(retval); 194 kfree(value); 195 196 return acl; 197 } 198 199 struct posix_acl *f2fs_get_acl(struct inode *inode, int type, bool rcu) 200 { 201 if (rcu) 202 return ERR_PTR(-ECHILD); 203 204 return __f2fs_get_acl(inode, type, NULL); 205 } 206 207 static int f2fs_acl_update_mode(struct mnt_idmap *idmap, 208 struct inode *inode, umode_t *mode_p, 209 struct posix_acl **acl) 210 { 211 umode_t mode = inode->i_mode; 212 int error; 213 214 if (is_inode_flag_set(inode, FI_ACL_MODE)) 215 mode = F2FS_I(inode)->i_acl_mode; 216 217 error = posix_acl_equiv_mode(*acl, &mode); 218 if (error < 0) 219 return error; 220 if (error == 0) 221 *acl = NULL; 222 if (!in_group_or_capable(idmap, inode, i_gid_into_vfsgid(idmap, inode))) 223 mode &= ~S_ISGID; 224 *mode_p = mode; 225 return 0; 226 } 227 228 static int __f2fs_set_acl(struct mnt_idmap *idmap, 229 struct inode *inode, int type, 230 struct posix_acl *acl, struct page *ipage) 231 { 232 int name_index; 233 void *value = NULL; 234 size_t size = 0; 235 int error; 236 umode_t mode = inode->i_mode; 237 238 switch (type) { 239 case ACL_TYPE_ACCESS: 240 name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS; 241 if (acl && !ipage) { 242 error = f2fs_acl_update_mode(idmap, inode, 243 &mode, &acl); 244 if (error) 245 return error; 246 set_acl_inode(inode, mode); 247 } 248 break; 249 250 case ACL_TYPE_DEFAULT: 251 name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT; 252 if (!S_ISDIR(inode->i_mode)) 253 return acl ? -EACCES : 0; 254 break; 255 256 default: 257 return -EINVAL; 258 } 259 260 if (acl) { 261 value = f2fs_acl_to_disk(F2FS_I_SB(inode), acl, &size); 262 if (IS_ERR(value)) { 263 clear_inode_flag(inode, FI_ACL_MODE); 264 return PTR_ERR(value); 265 } 266 } 267 268 error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0); 269 270 kfree(value); 271 if (!error) 272 set_cached_acl(inode, type, acl); 273 274 clear_inode_flag(inode, FI_ACL_MODE); 275 return error; 276 } 277 278 int f2fs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 279 struct posix_acl *acl, int type) 280 { 281 struct inode *inode = d_inode(dentry); 282 283 if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) 284 return -EIO; 285 286 return __f2fs_set_acl(idmap, inode, type, acl, NULL); 287 } 288 289 /* 290 * Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create 291 * are copied from posix_acl.c 292 */ 293 static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl, 294 gfp_t flags) 295 { 296 struct posix_acl *clone = NULL; 297 298 if (acl) { 299 int size = sizeof(struct posix_acl) + acl->a_count * 300 sizeof(struct posix_acl_entry); 301 clone = kmemdup(acl, size, flags); 302 if (clone) 303 refcount_set(&clone->a_refcount, 1); 304 } 305 return clone; 306 } 307 308 static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) 309 { 310 struct posix_acl_entry *pa, *pe; 311 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; 312 umode_t mode = *mode_p; 313 int not_equiv = 0; 314 315 /* assert(atomic_read(acl->a_refcount) == 1); */ 316 317 FOREACH_ACL_ENTRY(pa, acl, pe) { 318 switch (pa->e_tag) { 319 case ACL_USER_OBJ: 320 pa->e_perm &= (mode >> 6) | ~S_IRWXO; 321 mode &= (pa->e_perm << 6) | ~S_IRWXU; 322 break; 323 324 case ACL_USER: 325 case ACL_GROUP: 326 not_equiv = 1; 327 break; 328 329 case ACL_GROUP_OBJ: 330 group_obj = pa; 331 break; 332 333 case ACL_OTHER: 334 pa->e_perm &= mode | ~S_IRWXO; 335 mode &= pa->e_perm | ~S_IRWXO; 336 break; 337 338 case ACL_MASK: 339 mask_obj = pa; 340 not_equiv = 1; 341 break; 342 343 default: 344 return -EIO; 345 } 346 } 347 348 if (mask_obj) { 349 mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; 350 mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; 351 } else { 352 if (!group_obj) 353 return -EIO; 354 group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; 355 mode &= (group_obj->e_perm << 3) | ~S_IRWXG; 356 } 357 358 *mode_p = (*mode_p & ~S_IRWXUGO) | mode; 359 return not_equiv; 360 } 361 362 static int f2fs_acl_create(struct inode *dir, umode_t *mode, 363 struct posix_acl **default_acl, struct posix_acl **acl, 364 struct page *dpage) 365 { 366 struct posix_acl *p; 367 struct posix_acl *clone; 368 int ret; 369 370 *acl = NULL; 371 *default_acl = NULL; 372 373 if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) 374 return 0; 375 376 p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage); 377 if (!p || p == ERR_PTR(-EOPNOTSUPP)) { 378 *mode &= ~current_umask(); 379 return 0; 380 } 381 if (IS_ERR(p)) 382 return PTR_ERR(p); 383 384 clone = f2fs_acl_clone(p, GFP_NOFS); 385 if (!clone) { 386 ret = -ENOMEM; 387 goto release_acl; 388 } 389 390 ret = f2fs_acl_create_masq(clone, mode); 391 if (ret < 0) 392 goto release_clone; 393 394 if (ret == 0) 395 posix_acl_release(clone); 396 else 397 *acl = clone; 398 399 if (!S_ISDIR(*mode)) 400 posix_acl_release(p); 401 else 402 *default_acl = p; 403 404 return 0; 405 406 release_clone: 407 posix_acl_release(clone); 408 release_acl: 409 posix_acl_release(p); 410 return ret; 411 } 412 413 int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage, 414 struct page *dpage) 415 { 416 struct posix_acl *default_acl = NULL, *acl = NULL; 417 int error; 418 419 error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage); 420 if (error) 421 return error; 422 423 f2fs_mark_inode_dirty_sync(inode, true); 424 425 if (default_acl) { 426 error = __f2fs_set_acl(NULL, inode, ACL_TYPE_DEFAULT, default_acl, 427 ipage); 428 posix_acl_release(default_acl); 429 } else { 430 inode->i_default_acl = NULL; 431 } 432 if (acl) { 433 if (!error) 434 error = __f2fs_set_acl(NULL, inode, ACL_TYPE_ACCESS, acl, 435 ipage); 436 posix_acl_release(acl); 437 } else { 438 inode->i_acl = NULL; 439 } 440 441 return error; 442 } 443