b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame] | 1 | /* |
| 2 | * fs/cifs/xattr.c |
| 3 | * |
| 4 | * Copyright (c) International Business Machines Corp., 2003, 2007 |
| 5 | * Author(s): Steve French (sfrench@us.ibm.com) |
| 6 | * |
| 7 | * This library is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU Lesser General Public License as published |
| 9 | * by the Free Software Foundation; either version 2.1 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This library is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
| 15 | * the GNU Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public License |
| 18 | * along with this library; if not, write to the Free Software |
| 19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 20 | */ |
| 21 | |
| 22 | #include <linux/fs.h> |
| 23 | #include <linux/posix_acl_xattr.h> |
| 24 | #include <linux/slab.h> |
| 25 | #include <linux/xattr.h> |
| 26 | #include "cifsfs.h" |
| 27 | #include "cifspdu.h" |
| 28 | #include "cifsglob.h" |
| 29 | #include "cifsproto.h" |
| 30 | #include "cifs_debug.h" |
| 31 | #include "cifs_fs_sb.h" |
| 32 | #include "cifs_unicode.h" |
| 33 | |
| 34 | #define MAX_EA_VALUE_SIZE CIFSMaxBufSize |
| 35 | #define CIFS_XATTR_CIFS_ACL "system.cifs_acl" |
| 36 | #define CIFS_XATTR_ATTRIB "cifs.dosattrib" /* full name: user.cifs.dosattrib */ |
| 37 | #define CIFS_XATTR_CREATETIME "cifs.creationtime" /* user.cifs.creationtime */ |
| 38 | /* |
| 39 | * Although these three are just aliases for the above, need to move away from |
| 40 | * confusing users and using the 20+ year old term 'cifs' when it is no longer |
| 41 | * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago |
| 42 | */ |
| 43 | #define SMB3_XATTR_CIFS_ACL "system.smb3_acl" |
| 44 | #define SMB3_XATTR_ATTRIB "smb3.dosattrib" /* full name: user.smb3.dosattrib */ |
| 45 | #define SMB3_XATTR_CREATETIME "smb3.creationtime" /* user.smb3.creationtime */ |
| 46 | /* BB need to add server (Samba e.g) support for security and trusted prefix */ |
| 47 | |
| 48 | enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT }; |
| 49 | |
| 50 | static int cifs_xattr_set(const struct xattr_handler *handler, |
| 51 | struct dentry *dentry, struct inode *inode, |
| 52 | const char *name, const void *value, |
| 53 | size_t size, int flags) |
| 54 | { |
| 55 | int rc = -EOPNOTSUPP; |
| 56 | unsigned int xid; |
| 57 | struct super_block *sb = dentry->d_sb; |
| 58 | struct cifs_sb_info *cifs_sb = CIFS_SB(sb); |
| 59 | struct tcon_link *tlink; |
| 60 | struct cifs_tcon *pTcon; |
| 61 | char *full_path; |
| 62 | |
| 63 | tlink = cifs_sb_tlink(cifs_sb); |
| 64 | if (IS_ERR(tlink)) |
| 65 | return PTR_ERR(tlink); |
| 66 | pTcon = tlink_tcon(tlink); |
| 67 | |
| 68 | xid = get_xid(); |
| 69 | |
| 70 | full_path = build_path_from_dentry(dentry); |
| 71 | if (full_path == NULL) { |
| 72 | rc = -ENOMEM; |
| 73 | goto out; |
| 74 | } |
| 75 | /* return dos attributes as pseudo xattr */ |
| 76 | /* return alt name if available as pseudo attr */ |
| 77 | |
| 78 | /* if proc/fs/cifs/streamstoxattr is set then |
| 79 | search server for EAs or streams to |
| 80 | returns as xattrs */ |
| 81 | if (size > MAX_EA_VALUE_SIZE) { |
| 82 | cifs_dbg(FYI, "size of EA value too large\n"); |
| 83 | rc = -EOPNOTSUPP; |
| 84 | goto out; |
| 85 | } |
| 86 | |
| 87 | switch (handler->flags) { |
| 88 | case XATTR_USER: |
| 89 | if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR) |
| 90 | goto out; |
| 91 | |
| 92 | if (pTcon->ses->server->ops->set_EA) |
| 93 | rc = pTcon->ses->server->ops->set_EA(xid, pTcon, |
| 94 | full_path, name, value, (__u16)size, |
| 95 | cifs_sb->local_nls, cifs_sb); |
| 96 | break; |
| 97 | |
| 98 | case XATTR_CIFS_ACL: { |
| 99 | struct cifs_ntsd *pacl; |
| 100 | |
| 101 | if (!value) |
| 102 | goto out; |
| 103 | pacl = kmalloc(size, GFP_KERNEL); |
| 104 | if (!pacl) { |
| 105 | rc = -ENOMEM; |
| 106 | } else { |
| 107 | memcpy(pacl, value, size); |
| 108 | if (value && |
| 109 | pTcon->ses->server->ops->set_acl) |
| 110 | rc = pTcon->ses->server->ops->set_acl(pacl, |
| 111 | size, inode, |
| 112 | full_path, CIFS_ACL_DACL); |
| 113 | else |
| 114 | rc = -EOPNOTSUPP; |
| 115 | if (rc == 0) /* force revalidate of the inode */ |
| 116 | CIFS_I(inode)->time = 0; |
| 117 | kfree(pacl); |
| 118 | } |
| 119 | break; |
| 120 | } |
| 121 | |
| 122 | case XATTR_ACL_ACCESS: |
| 123 | #ifdef CONFIG_CIFS_POSIX |
| 124 | if (!value) |
| 125 | goto out; |
| 126 | if (sb->s_flags & SB_POSIXACL) |
| 127 | rc = CIFSSMBSetPosixACL(xid, pTcon, full_path, |
| 128 | value, (const int)size, |
| 129 | ACL_TYPE_ACCESS, cifs_sb->local_nls, |
| 130 | cifs_remap(cifs_sb)); |
| 131 | #endif /* CONFIG_CIFS_POSIX */ |
| 132 | break; |
| 133 | |
| 134 | case XATTR_ACL_DEFAULT: |
| 135 | #ifdef CONFIG_CIFS_POSIX |
| 136 | if (!value) |
| 137 | goto out; |
| 138 | if (sb->s_flags & SB_POSIXACL) |
| 139 | rc = CIFSSMBSetPosixACL(xid, pTcon, full_path, |
| 140 | value, (const int)size, |
| 141 | ACL_TYPE_DEFAULT, cifs_sb->local_nls, |
| 142 | cifs_remap(cifs_sb)); |
| 143 | #endif /* CONFIG_CIFS_POSIX */ |
| 144 | break; |
| 145 | } |
| 146 | |
| 147 | out: |
| 148 | kfree(full_path); |
| 149 | free_xid(xid); |
| 150 | cifs_put_tlink(tlink); |
| 151 | return rc; |
| 152 | } |
| 153 | |
| 154 | static int cifs_attrib_get(struct dentry *dentry, |
| 155 | struct inode *inode, void *value, |
| 156 | size_t size) |
| 157 | { |
| 158 | ssize_t rc; |
| 159 | __u32 *pattribute; |
| 160 | |
| 161 | rc = cifs_revalidate_dentry_attr(dentry); |
| 162 | |
| 163 | if (rc) |
| 164 | return rc; |
| 165 | |
| 166 | if ((value == NULL) || (size == 0)) |
| 167 | return sizeof(__u32); |
| 168 | else if (size < sizeof(__u32)) |
| 169 | return -ERANGE; |
| 170 | |
| 171 | /* return dos attributes as pseudo xattr */ |
| 172 | pattribute = (__u32 *)value; |
| 173 | *pattribute = CIFS_I(inode)->cifsAttrs; |
| 174 | |
| 175 | return sizeof(__u32); |
| 176 | } |
| 177 | |
| 178 | static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode, |
| 179 | void *value, size_t size) |
| 180 | { |
| 181 | ssize_t rc; |
| 182 | __u64 * pcreatetime; |
| 183 | |
| 184 | rc = cifs_revalidate_dentry_attr(dentry); |
| 185 | if (rc) |
| 186 | return rc; |
| 187 | |
| 188 | if ((value == NULL) || (size == 0)) |
| 189 | return sizeof(__u64); |
| 190 | else if (size < sizeof(__u64)) |
| 191 | return -ERANGE; |
| 192 | |
| 193 | /* return dos attributes as pseudo xattr */ |
| 194 | pcreatetime = (__u64 *)value; |
| 195 | *pcreatetime = CIFS_I(inode)->createtime; |
| 196 | return sizeof(__u64); |
| 197 | } |
| 198 | |
| 199 | |
| 200 | static int cifs_xattr_get(const struct xattr_handler *handler, |
| 201 | struct dentry *dentry, struct inode *inode, |
| 202 | const char *name, void *value, size_t size, int flags) |
| 203 | { |
| 204 | ssize_t rc = -EOPNOTSUPP; |
| 205 | unsigned int xid; |
| 206 | struct super_block *sb = dentry->d_sb; |
| 207 | struct cifs_sb_info *cifs_sb = CIFS_SB(sb); |
| 208 | struct tcon_link *tlink; |
| 209 | struct cifs_tcon *pTcon; |
| 210 | char *full_path; |
| 211 | |
| 212 | tlink = cifs_sb_tlink(cifs_sb); |
| 213 | if (IS_ERR(tlink)) |
| 214 | return PTR_ERR(tlink); |
| 215 | pTcon = tlink_tcon(tlink); |
| 216 | |
| 217 | xid = get_xid(); |
| 218 | |
| 219 | full_path = build_path_from_dentry(dentry); |
| 220 | if (full_path == NULL) { |
| 221 | rc = -ENOMEM; |
| 222 | goto out; |
| 223 | } |
| 224 | |
| 225 | /* return alt name if available as pseudo attr */ |
| 226 | switch (handler->flags) { |
| 227 | case XATTR_USER: |
| 228 | cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name); |
| 229 | if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) || |
| 230 | (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) { |
| 231 | rc = cifs_attrib_get(dentry, inode, value, size); |
| 232 | break; |
| 233 | } else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) || |
| 234 | (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) { |
| 235 | rc = cifs_creation_time_get(dentry, inode, value, size); |
| 236 | break; |
| 237 | } |
| 238 | |
| 239 | if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR) |
| 240 | goto out; |
| 241 | |
| 242 | if (pTcon->ses->server->ops->query_all_EAs) |
| 243 | rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon, |
| 244 | full_path, name, value, size, cifs_sb); |
| 245 | break; |
| 246 | |
| 247 | case XATTR_CIFS_ACL: { |
| 248 | u32 acllen; |
| 249 | struct cifs_ntsd *pacl; |
| 250 | |
| 251 | if (pTcon->ses->server->ops->get_acl == NULL) |
| 252 | goto out; /* rc already EOPNOTSUPP */ |
| 253 | |
| 254 | pacl = pTcon->ses->server->ops->get_acl(cifs_sb, |
| 255 | inode, full_path, &acllen); |
| 256 | if (IS_ERR(pacl)) { |
| 257 | rc = PTR_ERR(pacl); |
| 258 | cifs_dbg(VFS, "%s: error %zd getting sec desc\n", |
| 259 | __func__, rc); |
| 260 | } else { |
| 261 | if (value) { |
| 262 | if (acllen > size) |
| 263 | acllen = -ERANGE; |
| 264 | else |
| 265 | memcpy(value, pacl, acllen); |
| 266 | } |
| 267 | rc = acllen; |
| 268 | kfree(pacl); |
| 269 | } |
| 270 | break; |
| 271 | } |
| 272 | |
| 273 | case XATTR_ACL_ACCESS: |
| 274 | #ifdef CONFIG_CIFS_POSIX |
| 275 | if (sb->s_flags & SB_POSIXACL) |
| 276 | rc = CIFSSMBGetPosixACL(xid, pTcon, full_path, |
| 277 | value, size, ACL_TYPE_ACCESS, |
| 278 | cifs_sb->local_nls, |
| 279 | cifs_remap(cifs_sb)); |
| 280 | #endif /* CONFIG_CIFS_POSIX */ |
| 281 | break; |
| 282 | |
| 283 | case XATTR_ACL_DEFAULT: |
| 284 | #ifdef CONFIG_CIFS_POSIX |
| 285 | if (sb->s_flags & SB_POSIXACL) |
| 286 | rc = CIFSSMBGetPosixACL(xid, pTcon, full_path, |
| 287 | value, size, ACL_TYPE_DEFAULT, |
| 288 | cifs_sb->local_nls, |
| 289 | cifs_remap(cifs_sb)); |
| 290 | #endif /* CONFIG_CIFS_POSIX */ |
| 291 | break; |
| 292 | } |
| 293 | |
| 294 | /* We could add an additional check for streams ie |
| 295 | if proc/fs/cifs/streamstoxattr is set then |
| 296 | search server for EAs or streams to |
| 297 | returns as xattrs */ |
| 298 | |
| 299 | if (rc == -EINVAL) |
| 300 | rc = -EOPNOTSUPP; |
| 301 | |
| 302 | out: |
| 303 | kfree(full_path); |
| 304 | free_xid(xid); |
| 305 | cifs_put_tlink(tlink); |
| 306 | return rc; |
| 307 | } |
| 308 | |
| 309 | ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size) |
| 310 | { |
| 311 | ssize_t rc = -EOPNOTSUPP; |
| 312 | unsigned int xid; |
| 313 | struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb); |
| 314 | struct tcon_link *tlink; |
| 315 | struct cifs_tcon *pTcon; |
| 316 | char *full_path; |
| 317 | |
| 318 | if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR) |
| 319 | return -EOPNOTSUPP; |
| 320 | |
| 321 | tlink = cifs_sb_tlink(cifs_sb); |
| 322 | if (IS_ERR(tlink)) |
| 323 | return PTR_ERR(tlink); |
| 324 | pTcon = tlink_tcon(tlink); |
| 325 | |
| 326 | xid = get_xid(); |
| 327 | |
| 328 | full_path = build_path_from_dentry(direntry); |
| 329 | if (full_path == NULL) { |
| 330 | rc = -ENOMEM; |
| 331 | goto list_ea_exit; |
| 332 | } |
| 333 | /* return dos attributes as pseudo xattr */ |
| 334 | /* return alt name if available as pseudo attr */ |
| 335 | |
| 336 | /* if proc/fs/cifs/streamstoxattr is set then |
| 337 | search server for EAs or streams to |
| 338 | returns as xattrs */ |
| 339 | |
| 340 | if (pTcon->ses->server->ops->query_all_EAs) |
| 341 | rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon, |
| 342 | full_path, NULL, data, buf_size, cifs_sb); |
| 343 | list_ea_exit: |
| 344 | kfree(full_path); |
| 345 | free_xid(xid); |
| 346 | cifs_put_tlink(tlink); |
| 347 | return rc; |
| 348 | } |
| 349 | |
| 350 | static const struct xattr_handler cifs_user_xattr_handler = { |
| 351 | .prefix = XATTR_USER_PREFIX, |
| 352 | .flags = XATTR_USER, |
| 353 | .get = cifs_xattr_get, |
| 354 | .set = cifs_xattr_set, |
| 355 | }; |
| 356 | |
| 357 | /* os2.* attributes are treated like user.* attributes */ |
| 358 | static const struct xattr_handler cifs_os2_xattr_handler = { |
| 359 | .prefix = XATTR_OS2_PREFIX, |
| 360 | .flags = XATTR_USER, |
| 361 | .get = cifs_xattr_get, |
| 362 | .set = cifs_xattr_set, |
| 363 | }; |
| 364 | |
| 365 | static const struct xattr_handler cifs_cifs_acl_xattr_handler = { |
| 366 | .name = CIFS_XATTR_CIFS_ACL, |
| 367 | .flags = XATTR_CIFS_ACL, |
| 368 | .get = cifs_xattr_get, |
| 369 | .set = cifs_xattr_set, |
| 370 | }; |
| 371 | |
| 372 | /* |
| 373 | * Although this is just an alias for the above, need to move away from |
| 374 | * confusing users and using the 20 year old term 'cifs' when it is no |
| 375 | * longer secure and was replaced by SMB2/SMB3 a long time ago, and |
| 376 | * SMB3 and later are highly secure. |
| 377 | */ |
| 378 | static const struct xattr_handler smb3_acl_xattr_handler = { |
| 379 | .name = SMB3_XATTR_CIFS_ACL, |
| 380 | .flags = XATTR_CIFS_ACL, |
| 381 | .get = cifs_xattr_get, |
| 382 | .set = cifs_xattr_set, |
| 383 | }; |
| 384 | |
| 385 | static const struct xattr_handler cifs_posix_acl_access_xattr_handler = { |
| 386 | .name = XATTR_NAME_POSIX_ACL_ACCESS, |
| 387 | .flags = XATTR_ACL_ACCESS, |
| 388 | .get = cifs_xattr_get, |
| 389 | .set = cifs_xattr_set, |
| 390 | }; |
| 391 | |
| 392 | static const struct xattr_handler cifs_posix_acl_default_xattr_handler = { |
| 393 | .name = XATTR_NAME_POSIX_ACL_DEFAULT, |
| 394 | .flags = XATTR_ACL_DEFAULT, |
| 395 | .get = cifs_xattr_get, |
| 396 | .set = cifs_xattr_set, |
| 397 | }; |
| 398 | |
| 399 | const struct xattr_handler *cifs_xattr_handlers[] = { |
| 400 | &cifs_user_xattr_handler, |
| 401 | &cifs_os2_xattr_handler, |
| 402 | &cifs_cifs_acl_xattr_handler, |
| 403 | &smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */ |
| 404 | &cifs_posix_acl_access_xattr_handler, |
| 405 | &cifs_posix_acl_default_xattr_handler, |
| 406 | NULL |
| 407 | }; |