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