1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1999-2002 Robert N. M. Watson 5 * Copyright (c) 2002-2003 Networks Associates Technology, Inc. 6 * All rights reserved. 7 * 8 * This software was developed by Robert Watson for the TrustedBSD Project. 9 * 10 * This software was developed for the FreeBSD Project in part by Network 11 * Associates Laboratories, the Security Research Division of Network 12 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), 13 * as part of the DARPA CHATS research program. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 */ 37 38 /* 39 * Support for filesystem extended attribute: UFS-specific support functions. 40 */ 41 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD$"); 44 45 #include "opt_ufs.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/kernel.h> 50 #include <sys/ktr.h> 51 #include <sys/namei.h> 52 #include <sys/malloc.h> 53 #include <sys/fcntl.h> 54 #include <sys/priv.h> 55 #include <sys/proc.h> 56 #include <sys/vnode.h> 57 #include <sys/mount.h> 58 #include <sys/lock.h> 59 #include <sys/dirent.h> 60 #include <sys/extattr.h> 61 #include <sys/sx.h> 62 #include <sys/sysctl.h> 63 64 #include <vm/uma.h> 65 66 #include <ufs/ufs/dir.h> 67 #include <ufs/ufs/extattr.h> 68 #include <ufs/ufs/quota.h> 69 #include <ufs/ufs/ufsmount.h> 70 #include <ufs/ufs/inode.h> 71 #include <ufs/ufs/ufs_extern.h> 72 73 #ifdef UFS_EXTATTR 74 75 FEATURE(ufs_extattr, "ufs extended attribute support"); 76 77 static MALLOC_DEFINE(M_UFS_EXTATTR, "ufs_extattr", "ufs extended attribute"); 78 79 static int ufs_extattr_sync = 0; 80 SYSCTL_INT(_debug, OID_AUTO, ufs_extattr_sync, CTLFLAG_RW, &ufs_extattr_sync, 81 0, ""); 82 83 static int ufs_extattr_valid_attrname(int attrnamespace, 84 const char *attrname); 85 static int ufs_extattr_enable_with_open(struct ufsmount *ump, 86 struct vnode *vp, int attrnamespace, const char *attrname, 87 struct thread *td); 88 static int ufs_extattr_enable(struct ufsmount *ump, int attrnamespace, 89 const char *attrname, struct vnode *backing_vnode, 90 struct thread *td); 91 static int ufs_extattr_disable(struct ufsmount *ump, int attrnamespace, 92 const char *attrname, struct thread *td); 93 static int ufs_extattr_get(struct vnode *vp, int attrnamespace, 94 const char *name, struct uio *uio, size_t *size, 95 struct ucred *cred, struct thread *td); 96 static int ufs_extattr_set(struct vnode *vp, int attrnamespace, 97 const char *name, struct uio *uio, struct ucred *cred, 98 struct thread *td); 99 static int ufs_extattr_rm(struct vnode *vp, int attrnamespace, 100 const char *name, struct ucred *cred, struct thread *td); 101 #ifdef UFS_EXTATTR_AUTOSTART 102 static int ufs_extattr_autostart_locked(struct mount *mp, 103 struct thread *td); 104 #endif 105 static int ufs_extattr_start_locked(struct ufsmount *ump, 106 struct thread *td); 107 108 /* 109 * Per-FS attribute lock protecting attribute operations. 110 * 111 * XXXRW: Perhaps something more fine-grained would be appropriate, but at 112 * the end of the day we're going to contend on the vnode lock for the 113 * backing file anyway. 114 */ 115 static void 116 ufs_extattr_uepm_lock(struct ufsmount *ump) 117 { 118 119 sx_xlock(&ump->um_extattr.uepm_lock); 120 } 121 122 static void 123 ufs_extattr_uepm_unlock(struct ufsmount *ump) 124 { 125 126 sx_xunlock(&ump->um_extattr.uepm_lock); 127 } 128 129 /*- 130 * Determine whether the name passed is a valid name for an actual 131 * attribute. 132 * 133 * Invalid currently consists of: 134 * NULL pointer for attrname 135 * zero-length attrname (used to retrieve application attribute list) 136 */ 137 static int 138 ufs_extattr_valid_attrname(int attrnamespace, const char *attrname) 139 { 140 141 if (attrname == NULL) 142 return (0); 143 if (strlen(attrname) == 0) 144 return (0); 145 return (1); 146 } 147 148 /* 149 * Locate an attribute given a name and mountpoint. 150 * Must be holding uepm lock for the mount point. 151 */ 152 static struct ufs_extattr_list_entry * 153 ufs_extattr_find_attr(struct ufsmount *ump, int attrnamespace, 154 const char *attrname) 155 { 156 struct ufs_extattr_list_entry *search_attribute; 157 158 sx_assert(&ump->um_extattr.uepm_lock, SA_XLOCKED); 159 160 for (search_attribute = LIST_FIRST(&ump->um_extattr.uepm_list); 161 search_attribute != NULL; 162 search_attribute = LIST_NEXT(search_attribute, uele_entries)) { 163 if (!(strncmp(attrname, search_attribute->uele_attrname, 164 UFS_EXTATTR_MAXEXTATTRNAME)) && 165 (attrnamespace == search_attribute->uele_attrnamespace)) { 166 return (search_attribute); 167 } 168 } 169 170 return (0); 171 } 172 173 /* 174 * Initialize per-FS structures supporting extended attributes. Do not 175 * start extended attributes yet. 176 */ 177 void 178 ufs_extattr_uepm_init(struct ufs_extattr_per_mount *uepm) 179 { 180 181 uepm->uepm_flags = 0; 182 LIST_INIT(&uepm->uepm_list); 183 sx_init(&uepm->uepm_lock, "ufs_extattr_sx"); 184 uepm->uepm_flags |= UFS_EXTATTR_UEPM_INITIALIZED; 185 } 186 187 /* 188 * Destroy per-FS structures supporting extended attributes. Assumes 189 * that EAs have already been stopped, and will panic if not. 190 */ 191 void 192 ufs_extattr_uepm_destroy(struct ufs_extattr_per_mount *uepm) 193 { 194 195 if (!(uepm->uepm_flags & UFS_EXTATTR_UEPM_INITIALIZED)) 196 panic("ufs_extattr_uepm_destroy: not initialized"); 197 198 if ((uepm->uepm_flags & UFS_EXTATTR_UEPM_STARTED)) 199 panic("ufs_extattr_uepm_destroy: called while still started"); 200 201 /* 202 * It's not clear that either order for the next two lines is 203 * ideal, and it should never be a problem if this is only called 204 * during unmount, and with vfs_busy(). 205 */ 206 uepm->uepm_flags &= ~UFS_EXTATTR_UEPM_INITIALIZED; 207 sx_destroy(&uepm->uepm_lock); 208 } 209 210 /* 211 * Start extended attribute support on an FS. 212 */ 213 int 214 ufs_extattr_start(struct mount *mp, struct thread *td) 215 { 216 struct ufsmount *ump; 217 int error = 0; 218 219 ump = VFSTOUFS(mp); 220 221 ufs_extattr_uepm_lock(ump); 222 error = ufs_extattr_start_locked(ump, td); 223 ufs_extattr_uepm_unlock(ump); 224 return (error); 225 } 226 227 static int 228 ufs_extattr_start_locked(struct ufsmount *ump, struct thread *td) 229 { 230 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_INITIALIZED)) 231 return (EOPNOTSUPP); 232 if (ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED) 233 return (EBUSY); 234 235 ump->um_extattr.uepm_flags |= UFS_EXTATTR_UEPM_STARTED; 236 ump->um_extattr.uepm_ucred = crhold(td->td_ucred); 237 return (0); 238 } 239 240 #ifdef UFS_EXTATTR_AUTOSTART 241 /* 242 * Helper routine: given a locked parent directory and filename, return 243 * the locked vnode of the inode associated with the name. Will not 244 * follow symlinks, may return any type of vnode. Lock on parent will 245 * be released even in the event of a failure. In the event that the 246 * target is the parent (i.e., "."), there will be two references and 247 * one lock, requiring the caller to possibly special-case. 248 */ 249 #define UE_GETDIR_LOCKPARENT 1 250 #define UE_GETDIR_LOCKPARENT_DONT 2 251 static int 252 ufs_extattr_lookup(struct vnode *start_dvp, int lockparent, char *dirname, 253 struct vnode **vp, struct thread *td) 254 { 255 struct vop_cachedlookup_args vargs; 256 struct componentname cnp; 257 struct vnode *target_vp; 258 int error; 259 260 bzero(&cnp, sizeof(cnp)); 261 cnp.cn_nameiop = LOOKUP; 262 cnp.cn_flags = ISLASTCN; 263 if (lockparent == UE_GETDIR_LOCKPARENT) 264 cnp.cn_flags |= LOCKPARENT; 265 cnp.cn_lkflags = LK_EXCLUSIVE; 266 cnp.cn_thread = td; 267 cnp.cn_cred = td->td_ucred; 268 cnp.cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK); 269 cnp.cn_nameptr = cnp.cn_pnbuf; 270 error = copystr(dirname, cnp.cn_pnbuf, MAXPATHLEN, 271 (size_t *) &cnp.cn_namelen); 272 if (error) { 273 if (lockparent == UE_GETDIR_LOCKPARENT_DONT) { 274 VOP_UNLOCK(start_dvp); 275 } 276 uma_zfree(namei_zone, cnp.cn_pnbuf); 277 printf("ufs_extattr_lookup: copystr failed\n"); 278 return (error); 279 } 280 cnp.cn_namelen--; /* trim nul termination */ 281 vargs.a_gen.a_desc = NULL; 282 vargs.a_dvp = start_dvp; 283 vargs.a_vpp = &target_vp; 284 vargs.a_cnp = &cnp; 285 error = ufs_lookup(&vargs); 286 uma_zfree(namei_zone, cnp.cn_pnbuf); 287 if (error) { 288 /* 289 * Error condition, may have to release the lock on the parent 290 * if ufs_lookup() didn't. 291 */ 292 if (lockparent == UE_GETDIR_LOCKPARENT_DONT) 293 VOP_UNLOCK(start_dvp); 294 295 /* 296 * Check that ufs_lookup() didn't release the lock when we 297 * didn't want it to. 298 */ 299 if (lockparent == UE_GETDIR_LOCKPARENT) 300 ASSERT_VOP_LOCKED(start_dvp, "ufs_extattr_lookup"); 301 302 return (error); 303 } 304 /* 305 if (target_vp == start_dvp) 306 panic("ufs_extattr_lookup: target_vp == start_dvp"); 307 */ 308 309 if (target_vp != start_dvp && lockparent == UE_GETDIR_LOCKPARENT_DONT) 310 VOP_UNLOCK(start_dvp); 311 312 if (lockparent == UE_GETDIR_LOCKPARENT) 313 ASSERT_VOP_LOCKED(start_dvp, "ufs_extattr_lookup"); 314 315 /* printf("ufs_extattr_lookup: success\n"); */ 316 *vp = target_vp; 317 return (0); 318 } 319 #endif /* !UFS_EXTATTR_AUTOSTART */ 320 321 /* 322 * Enable an EA using the passed filesystem, backing vnode, attribute name, 323 * namespace, and proc. Will perform a VOP_OPEN() on the vp, so expects vp 324 * to be locked when passed in. The vnode will be returned unlocked, 325 * regardless of success/failure of the function. As a result, the caller 326 * will always need to vrele(), but not vput(). 327 */ 328 static int 329 ufs_extattr_enable_with_open(struct ufsmount *ump, struct vnode *vp, 330 int attrnamespace, const char *attrname, struct thread *td) 331 { 332 int error; 333 334 error = VOP_OPEN(vp, FREAD|FWRITE, td->td_ucred, td, NULL); 335 if (error) { 336 printf("ufs_extattr_enable_with_open.VOP_OPEN(): failed " 337 "with %d\n", error); 338 VOP_UNLOCK(vp); 339 return (error); 340 } 341 342 error = VOP_ADD_WRITECOUNT(vp, 1); 343 if (error != 0) { 344 VOP_CLOSE(vp, FREAD | FWRITE, td->td_ucred, td); 345 VOP_UNLOCK(vp); 346 return (error); 347 } 348 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d", __func__, vp, 349 vp->v_writecount); 350 351 vref(vp); 352 353 VOP_UNLOCK(vp); 354 355 error = ufs_extattr_enable(ump, attrnamespace, attrname, vp, td); 356 if (error != 0) 357 vn_close(vp, FREAD|FWRITE, td->td_ucred, td); 358 return (error); 359 } 360 361 #ifdef UFS_EXTATTR_AUTOSTART 362 /* 363 * Given a locked directory vnode, iterate over the names in the directory 364 * and use ufs_extattr_lookup() to retrieve locked vnodes of potential 365 * attribute files. Then invoke ufs_extattr_enable_with_open() on each 366 * to attempt to start the attribute. Leaves the directory locked on 367 * exit. 368 */ 369 static int 370 ufs_extattr_iterate_directory(struct ufsmount *ump, struct vnode *dvp, 371 int attrnamespace, struct thread *td) 372 { 373 struct vop_readdir_args vargs; 374 struct dirent *dp, *edp; 375 struct vnode *attr_vp; 376 struct uio auio; 377 struct iovec aiov; 378 char *dirbuf; 379 int error, eofflag = 0; 380 381 if (dvp->v_type != VDIR) 382 return (ENOTDIR); 383 384 dirbuf = malloc(DIRBLKSIZ, M_TEMP, M_WAITOK); 385 386 auio.uio_iov = &aiov; 387 auio.uio_iovcnt = 1; 388 auio.uio_rw = UIO_READ; 389 auio.uio_segflg = UIO_SYSSPACE; 390 auio.uio_td = td; 391 auio.uio_offset = 0; 392 393 vargs.a_gen.a_desc = NULL; 394 vargs.a_vp = dvp; 395 vargs.a_uio = &auio; 396 vargs.a_cred = td->td_ucred; 397 vargs.a_eofflag = &eofflag; 398 vargs.a_ncookies = NULL; 399 vargs.a_cookies = NULL; 400 401 while (!eofflag) { 402 auio.uio_resid = DIRBLKSIZ; 403 aiov.iov_base = dirbuf; 404 aiov.iov_len = DIRBLKSIZ; 405 error = ufs_readdir(&vargs); 406 if (error) { 407 printf("ufs_extattr_iterate_directory: ufs_readdir " 408 "%d\n", error); 409 return (error); 410 } 411 412 edp = (struct dirent *)&dirbuf[DIRBLKSIZ - auio.uio_resid]; 413 for (dp = (struct dirent *)dirbuf; dp < edp; ) { 414 if (dp->d_reclen == 0) 415 break; 416 error = ufs_extattr_lookup(dvp, UE_GETDIR_LOCKPARENT, 417 dp->d_name, &attr_vp, td); 418 if (error) { 419 printf("ufs_extattr_iterate_directory: lookup " 420 "%s %d\n", dp->d_name, error); 421 } else if (attr_vp == dvp) { 422 vrele(attr_vp); 423 } else if (attr_vp->v_type != VREG) { 424 vput(attr_vp); 425 } else { 426 error = ufs_extattr_enable_with_open(ump, 427 attr_vp, attrnamespace, dp->d_name, td); 428 vrele(attr_vp); 429 if (error) { 430 printf("ufs_extattr_iterate_directory: " 431 "enable %s %d\n", dp->d_name, 432 error); 433 } else if (bootverbose) { 434 printf("UFS autostarted EA %s\n", 435 dp->d_name); 436 } 437 } 438 dp = (struct dirent *) ((char *)dp + dp->d_reclen); 439 if (dp >= edp) 440 break; 441 } 442 } 443 free(dirbuf, M_TEMP); 444 445 return (0); 446 } 447 448 /* 449 * Auto-start of extended attributes, to be executed (optionally) at 450 * mount-time. 451 */ 452 int 453 ufs_extattr_autostart(struct mount *mp, struct thread *td) 454 { 455 struct ufsmount *ump; 456 int error; 457 458 ump = VFSTOUFS(mp); 459 ufs_extattr_uepm_lock(ump); 460 error = ufs_extattr_autostart_locked(mp, td); 461 ufs_extattr_uepm_unlock(ump); 462 return (error); 463 } 464 465 static int 466 ufs_extattr_autostart_locked(struct mount *mp, struct thread *td) 467 { 468 struct vnode *rvp, *attr_dvp, *attr_system_dvp, *attr_user_dvp; 469 struct ufsmount *ump = VFSTOUFS(mp); 470 int error; 471 472 /* 473 * UFS_EXTATTR applies only to UFS1, as UFS2 uses native extended 474 * attributes, so don't autostart. 475 */ 476 if (ump->um_fstype != UFS1) 477 return (0); 478 479 /* 480 * Does UFS_EXTATTR_FSROOTSUBDIR exist off the filesystem root? 481 * If so, automatically start EA's. 482 */ 483 error = VFS_ROOT(mp, LK_EXCLUSIVE, &rvp); 484 if (error) { 485 printf("ufs_extattr_autostart.VFS_ROOT() returned %d\n", 486 error); 487 return (error); 488 } 489 490 error = ufs_extattr_lookup(rvp, UE_GETDIR_LOCKPARENT_DONT, 491 UFS_EXTATTR_FSROOTSUBDIR, &attr_dvp, td); 492 if (error) { 493 /* rvp ref'd but now unlocked */ 494 vrele(rvp); 495 return (error); 496 } 497 if (rvp == attr_dvp) { 498 /* Should never happen. */ 499 vput(rvp); 500 vrele(attr_dvp); 501 return (EINVAL); 502 } 503 vrele(rvp); 504 505 if (attr_dvp->v_type != VDIR) { 506 printf("ufs_extattr_autostart: %s != VDIR\n", 507 UFS_EXTATTR_FSROOTSUBDIR); 508 goto return_vput_attr_dvp; 509 } 510 511 error = ufs_extattr_start_locked(ump, td); 512 if (error) { 513 printf("ufs_extattr_autostart: ufs_extattr_start failed (%d)\n", 514 error); 515 goto return_vput_attr_dvp; 516 } 517 518 /* 519 * Look for two subdirectories: UFS_EXTATTR_SUBDIR_SYSTEM, 520 * UFS_EXTATTR_SUBDIR_USER. For each, iterate over the sub-directory, 521 * and start with appropriate type. Failures in either don't 522 * result in an over-all failure. attr_dvp is left locked to 523 * be cleaned up on exit. 524 */ 525 error = ufs_extattr_lookup(attr_dvp, UE_GETDIR_LOCKPARENT, 526 UFS_EXTATTR_SUBDIR_SYSTEM, &attr_system_dvp, td); 527 if (!error) { 528 error = ufs_extattr_iterate_directory(VFSTOUFS(mp), 529 attr_system_dvp, EXTATTR_NAMESPACE_SYSTEM, td); 530 if (error) 531 printf("ufs_extattr_iterate_directory returned %d\n", 532 error); 533 vput(attr_system_dvp); 534 } 535 536 error = ufs_extattr_lookup(attr_dvp, UE_GETDIR_LOCKPARENT, 537 UFS_EXTATTR_SUBDIR_USER, &attr_user_dvp, td); 538 if (!error) { 539 error = ufs_extattr_iterate_directory(VFSTOUFS(mp), 540 attr_user_dvp, EXTATTR_NAMESPACE_USER, td); 541 if (error) 542 printf("ufs_extattr_iterate_directory returned %d\n", 543 error); 544 vput(attr_user_dvp); 545 } 546 547 /* Mask startup failures in sub-directories. */ 548 error = 0; 549 550 return_vput_attr_dvp: 551 vput(attr_dvp); 552 553 return (error); 554 } 555 #endif /* !UFS_EXTATTR_AUTOSTART */ 556 557 /* 558 * Stop extended attribute support on an FS. 559 */ 560 int 561 ufs_extattr_stop(struct mount *mp, struct thread *td) 562 { 563 struct ufs_extattr_list_entry *uele; 564 struct ufsmount *ump = VFSTOUFS(mp); 565 int error = 0; 566 567 ufs_extattr_uepm_lock(ump); 568 569 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) { 570 error = EOPNOTSUPP; 571 goto unlock; 572 } 573 574 while ((uele = LIST_FIRST(&ump->um_extattr.uepm_list)) != NULL) { 575 ufs_extattr_disable(ump, uele->uele_attrnamespace, 576 uele->uele_attrname, td); 577 } 578 579 ump->um_extattr.uepm_flags &= ~UFS_EXTATTR_UEPM_STARTED; 580 581 crfree(ump->um_extattr.uepm_ucred); 582 ump->um_extattr.uepm_ucred = NULL; 583 584 unlock: 585 ufs_extattr_uepm_unlock(ump); 586 587 return (error); 588 } 589 590 /* 591 * Enable a named attribute on the specified filesystem; provide an 592 * unlocked backing vnode to hold the attribute data. 593 */ 594 static int 595 ufs_extattr_enable(struct ufsmount *ump, int attrnamespace, 596 const char *attrname, struct vnode *backing_vnode, struct thread *td) 597 { 598 struct ufs_extattr_list_entry *attribute; 599 struct iovec aiov; 600 struct uio auio; 601 int error = 0; 602 603 if (!ufs_extattr_valid_attrname(attrnamespace, attrname)) 604 return (EINVAL); 605 if (backing_vnode->v_type != VREG) 606 return (EINVAL); 607 608 attribute = malloc(sizeof(struct ufs_extattr_list_entry), 609 M_UFS_EXTATTR, M_WAITOK); 610 611 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) { 612 error = EOPNOTSUPP; 613 goto free_exit; 614 } 615 616 if (ufs_extattr_find_attr(ump, attrnamespace, attrname)) { 617 error = EEXIST; 618 goto free_exit; 619 } 620 621 strncpy(attribute->uele_attrname, attrname, 622 UFS_EXTATTR_MAXEXTATTRNAME); 623 attribute->uele_attrnamespace = attrnamespace; 624 bzero(&attribute->uele_fileheader, 625 sizeof(struct ufs_extattr_fileheader)); 626 627 attribute->uele_backing_vnode = backing_vnode; 628 629 auio.uio_iov = &aiov; 630 auio.uio_iovcnt = 1; 631 aiov.iov_base = (caddr_t) &attribute->uele_fileheader; 632 aiov.iov_len = sizeof(struct ufs_extattr_fileheader); 633 auio.uio_resid = sizeof(struct ufs_extattr_fileheader); 634 auio.uio_offset = (off_t) 0; 635 auio.uio_segflg = UIO_SYSSPACE; 636 auio.uio_rw = UIO_READ; 637 auio.uio_td = td; 638 639 vn_lock(backing_vnode, LK_SHARED | LK_RETRY); 640 error = VOP_READ(backing_vnode, &auio, IO_NODELOCKED, 641 ump->um_extattr.uepm_ucred); 642 643 if (error) 644 goto unlock_free_exit; 645 646 if (auio.uio_resid != 0) { 647 printf("ufs_extattr_enable: malformed attribute header\n"); 648 error = EINVAL; 649 goto unlock_free_exit; 650 } 651 652 if (attribute->uele_fileheader.uef_magic != UFS_EXTATTR_MAGIC) { 653 printf("ufs_extattr_enable: invalid attribute header magic\n"); 654 error = EINVAL; 655 goto unlock_free_exit; 656 } 657 658 if (attribute->uele_fileheader.uef_version != UFS_EXTATTR_VERSION) { 659 printf("ufs_extattr_enable: incorrect attribute header " 660 "version\n"); 661 error = EINVAL; 662 goto unlock_free_exit; 663 } 664 665 ASSERT_VOP_LOCKED(backing_vnode, "ufs_extattr_enable"); 666 LIST_INSERT_HEAD(&ump->um_extattr.uepm_list, attribute, 667 uele_entries); 668 669 VOP_UNLOCK(backing_vnode); 670 return (0); 671 672 unlock_free_exit: 673 VOP_UNLOCK(backing_vnode); 674 675 free_exit: 676 free(attribute, M_UFS_EXTATTR); 677 return (error); 678 } 679 680 /* 681 * Disable extended attribute support on an FS. 682 */ 683 static int 684 ufs_extattr_disable(struct ufsmount *ump, int attrnamespace, 685 const char *attrname, struct thread *td) 686 { 687 struct ufs_extattr_list_entry *uele; 688 int error = 0; 689 690 if (!ufs_extattr_valid_attrname(attrnamespace, attrname)) 691 return (EINVAL); 692 693 uele = ufs_extattr_find_attr(ump, attrnamespace, attrname); 694 if (!uele) 695 return (ENOATTR); 696 697 LIST_REMOVE(uele, uele_entries); 698 699 vn_lock(uele->uele_backing_vnode, LK_SHARED | LK_RETRY); 700 ASSERT_VOP_LOCKED(uele->uele_backing_vnode, "ufs_extattr_disable"); 701 VOP_UNLOCK(uele->uele_backing_vnode); 702 error = vn_close(uele->uele_backing_vnode, FREAD|FWRITE, 703 td->td_ucred, td); 704 705 free(uele, M_UFS_EXTATTR); 706 707 return (error); 708 } 709 710 /* 711 * VFS call to manage extended attributes in UFS. If filename_vp is 712 * non-NULL, it must be passed in locked, and regardless of errors in 713 * processing, will be unlocked. 714 */ 715 int 716 ufs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp, 717 int attrnamespace, const char *attrname) 718 { 719 struct ufsmount *ump = VFSTOUFS(mp); 720 struct thread *td = curthread; 721 int error; 722 723 /* 724 * Processes with privilege, but in jail, are not allowed to 725 * configure extended attributes. 726 */ 727 error = priv_check(td, PRIV_UFS_EXTATTRCTL); 728 if (error) { 729 if (filename_vp != NULL) 730 VOP_UNLOCK(filename_vp); 731 return (error); 732 } 733 734 /* 735 * We only allow extattrctl(2) on UFS1 file systems, as UFS2 uses 736 * native extended attributes. 737 */ 738 if (ump->um_fstype != UFS1) { 739 if (filename_vp != NULL) 740 VOP_UNLOCK(filename_vp); 741 return (EOPNOTSUPP); 742 } 743 744 switch(cmd) { 745 case UFS_EXTATTR_CMD_START: 746 if (filename_vp != NULL) { 747 VOP_UNLOCK(filename_vp); 748 return (EINVAL); 749 } 750 if (attrname != NULL) 751 return (EINVAL); 752 753 error = ufs_extattr_start(mp, td); 754 755 return (error); 756 757 case UFS_EXTATTR_CMD_STOP: 758 if (filename_vp != NULL) { 759 VOP_UNLOCK(filename_vp); 760 return (EINVAL); 761 } 762 if (attrname != NULL) 763 return (EINVAL); 764 765 error = ufs_extattr_stop(mp, td); 766 767 return (error); 768 769 case UFS_EXTATTR_CMD_ENABLE: 770 771 if (filename_vp == NULL) 772 return (EINVAL); 773 if (attrname == NULL) { 774 VOP_UNLOCK(filename_vp); 775 return (EINVAL); 776 } 777 778 /* 779 * ufs_extattr_enable_with_open() will always unlock the 780 * vnode, regardless of failure. 781 */ 782 ufs_extattr_uepm_lock(ump); 783 error = ufs_extattr_enable_with_open(ump, filename_vp, 784 attrnamespace, attrname, td); 785 ufs_extattr_uepm_unlock(ump); 786 787 return (error); 788 789 case UFS_EXTATTR_CMD_DISABLE: 790 791 if (filename_vp != NULL) { 792 VOP_UNLOCK(filename_vp); 793 return (EINVAL); 794 } 795 if (attrname == NULL) 796 return (EINVAL); 797 798 ufs_extattr_uepm_lock(ump); 799 error = ufs_extattr_disable(ump, attrnamespace, attrname, 800 td); 801 ufs_extattr_uepm_unlock(ump); 802 803 return (error); 804 805 default: 806 return (EINVAL); 807 } 808 } 809 810 /* 811 * Vnode operating to retrieve a named extended attribute. 812 */ 813 int 814 ufs_getextattr(struct vop_getextattr_args *ap) 815 /* 816 vop_getextattr { 817 IN struct vnode *a_vp; 818 IN int a_attrnamespace; 819 IN const char *a_name; 820 INOUT struct uio *a_uio; 821 OUT size_t *a_size; 822 IN struct ucred *a_cred; 823 IN struct thread *a_td; 824 }; 825 */ 826 { 827 struct mount *mp = ap->a_vp->v_mount; 828 struct ufsmount *ump = VFSTOUFS(mp); 829 int error; 830 831 ufs_extattr_uepm_lock(ump); 832 833 error = ufs_extattr_get(ap->a_vp, ap->a_attrnamespace, ap->a_name, 834 ap->a_uio, ap->a_size, ap->a_cred, ap->a_td); 835 836 ufs_extattr_uepm_unlock(ump); 837 838 return (error); 839 } 840 841 /* 842 * Real work associated with retrieving a named attribute--assumes that 843 * the attribute lock has already been grabbed. 844 */ 845 static int 846 ufs_extattr_get(struct vnode *vp, int attrnamespace, const char *name, 847 struct uio *uio, size_t *size, struct ucred *cred, struct thread *td) 848 { 849 struct ufs_extattr_list_entry *attribute; 850 struct ufs_extattr_header ueh; 851 struct iovec local_aiov; 852 struct uio local_aio; 853 struct mount *mp = vp->v_mount; 854 struct ufsmount *ump = VFSTOUFS(mp); 855 struct inode *ip = VTOI(vp); 856 off_t base_offset; 857 size_t len, old_len; 858 int error = 0; 859 860 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) 861 return (EOPNOTSUPP); 862 863 if (strlen(name) == 0) 864 return (EINVAL); 865 866 error = extattr_check_cred(vp, attrnamespace, cred, td, VREAD); 867 if (error) 868 return (error); 869 870 attribute = ufs_extattr_find_attr(ump, attrnamespace, name); 871 if (!attribute) 872 return (ENOATTR); 873 874 /* 875 * Allow only offsets of zero to encourage the read/replace 876 * extended attribute semantic. Otherwise we can't guarantee 877 * atomicity, as we don't provide locks for extended attributes. 878 */ 879 if (uio != NULL && uio->uio_offset != 0) 880 return (ENXIO); 881 882 /* 883 * Find base offset of header in file based on file header size, and 884 * data header size + maximum data size, indexed by inode number. 885 */ 886 base_offset = sizeof(struct ufs_extattr_fileheader) + 887 ip->i_number * (sizeof(struct ufs_extattr_header) + 888 attribute->uele_fileheader.uef_size); 889 890 /* 891 * Read in the data header to see if the data is defined, and if so 892 * how much. 893 */ 894 bzero(&ueh, sizeof(struct ufs_extattr_header)); 895 local_aiov.iov_base = (caddr_t) &ueh; 896 local_aiov.iov_len = sizeof(struct ufs_extattr_header); 897 local_aio.uio_iov = &local_aiov; 898 local_aio.uio_iovcnt = 1; 899 local_aio.uio_rw = UIO_READ; 900 local_aio.uio_segflg = UIO_SYSSPACE; 901 local_aio.uio_td = td; 902 local_aio.uio_offset = base_offset; 903 local_aio.uio_resid = sizeof(struct ufs_extattr_header); 904 905 /* 906 * Acquire locks. 907 * 908 * Don't need to get a lock on the backing file if the getattr is 909 * being applied to the backing file, as the lock is already held. 910 */ 911 if (attribute->uele_backing_vnode != vp) 912 vn_lock(attribute->uele_backing_vnode, LK_SHARED | LK_RETRY); 913 914 error = VOP_READ(attribute->uele_backing_vnode, &local_aio, 915 IO_NODELOCKED, ump->um_extattr.uepm_ucred); 916 if (error) 917 goto vopunlock_exit; 918 919 /* Defined? */ 920 if ((ueh.ueh_flags & UFS_EXTATTR_ATTR_FLAG_INUSE) == 0) { 921 error = ENOATTR; 922 goto vopunlock_exit; 923 } 924 925 /* Valid for the current inode generation? */ 926 if (ueh.ueh_i_gen != ip->i_gen) { 927 /* 928 * The inode itself has a different generation number 929 * than the attribute data. For now, the best solution 930 * is to coerce this to undefined, and let it get cleaned 931 * up by the next write or extattrctl clean. 932 */ 933 printf("ufs_extattr_get (%s): inode number inconsistency (%d, %ju)\n", 934 mp->mnt_stat.f_mntonname, ueh.ueh_i_gen, (uintmax_t)ip->i_gen); 935 error = ENOATTR; 936 goto vopunlock_exit; 937 } 938 939 /* Local size consistency check. */ 940 if (ueh.ueh_len > attribute->uele_fileheader.uef_size) { 941 error = ENXIO; 942 goto vopunlock_exit; 943 } 944 945 /* Return full data size if caller requested it. */ 946 if (size != NULL) 947 *size = ueh.ueh_len; 948 949 /* Return data if the caller requested it. */ 950 if (uio != NULL) { 951 /* Allow for offset into the attribute data. */ 952 uio->uio_offset = base_offset + sizeof(struct 953 ufs_extattr_header); 954 955 /* 956 * Figure out maximum to transfer -- use buffer size and 957 * local data limit. 958 */ 959 len = MIN(uio->uio_resid, ueh.ueh_len); 960 old_len = uio->uio_resid; 961 uio->uio_resid = len; 962 963 error = VOP_READ(attribute->uele_backing_vnode, uio, 964 IO_NODELOCKED, ump->um_extattr.uepm_ucred); 965 if (error) 966 goto vopunlock_exit; 967 968 uio->uio_resid = old_len - (len - uio->uio_resid); 969 } 970 971 vopunlock_exit: 972 973 if (uio != NULL) 974 uio->uio_offset = 0; 975 976 if (attribute->uele_backing_vnode != vp) 977 VOP_UNLOCK(attribute->uele_backing_vnode); 978 979 return (error); 980 } 981 982 /* 983 * Vnode operation to remove a named attribute. 984 */ 985 int 986 ufs_deleteextattr(struct vop_deleteextattr_args *ap) 987 /* 988 vop_deleteextattr { 989 IN struct vnode *a_vp; 990 IN int a_attrnamespace; 991 IN const char *a_name; 992 IN struct ucred *a_cred; 993 IN struct thread *a_td; 994 }; 995 */ 996 { 997 struct mount *mp = ap->a_vp->v_mount; 998 struct ufsmount *ump = VFSTOUFS(mp); 999 int error; 1000 1001 ufs_extattr_uepm_lock(ump); 1002 1003 error = ufs_extattr_rm(ap->a_vp, ap->a_attrnamespace, ap->a_name, 1004 ap->a_cred, ap->a_td); 1005 1006 ufs_extattr_uepm_unlock(ump); 1007 1008 return (error); 1009 } 1010 1011 /* 1012 * Vnode operation to set a named attribute. 1013 */ 1014 int 1015 ufs_setextattr(struct vop_setextattr_args *ap) 1016 /* 1017 vop_setextattr { 1018 IN struct vnode *a_vp; 1019 IN int a_attrnamespace; 1020 IN const char *a_name; 1021 INOUT struct uio *a_uio; 1022 IN struct ucred *a_cred; 1023 IN struct thread *a_td; 1024 }; 1025 */ 1026 { 1027 struct mount *mp = ap->a_vp->v_mount; 1028 struct ufsmount *ump = VFSTOUFS(mp); 1029 int error; 1030 1031 /* 1032 * XXX: No longer a supported way to delete extended attributes. 1033 */ 1034 if (ap->a_uio == NULL) 1035 return (EINVAL); 1036 1037 ufs_extattr_uepm_lock(ump); 1038 1039 error = ufs_extattr_set(ap->a_vp, ap->a_attrnamespace, ap->a_name, 1040 ap->a_uio, ap->a_cred, ap->a_td); 1041 1042 ufs_extattr_uepm_unlock(ump); 1043 1044 return (error); 1045 } 1046 1047 /* 1048 * Real work associated with setting a vnode's extended attributes; 1049 * assumes that the attribute lock has already been grabbed. 1050 */ 1051 static int 1052 ufs_extattr_set(struct vnode *vp, int attrnamespace, const char *name, 1053 struct uio *uio, struct ucred *cred, struct thread *td) 1054 { 1055 struct ufs_extattr_list_entry *attribute; 1056 struct ufs_extattr_header ueh; 1057 struct iovec local_aiov; 1058 struct uio local_aio; 1059 struct mount *mp = vp->v_mount; 1060 struct ufsmount *ump = VFSTOUFS(mp); 1061 struct inode *ip = VTOI(vp); 1062 off_t base_offset; 1063 int error = 0, ioflag; 1064 1065 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1066 return (EROFS); 1067 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) 1068 return (EOPNOTSUPP); 1069 if (!ufs_extattr_valid_attrname(attrnamespace, name)) 1070 return (EINVAL); 1071 1072 error = extattr_check_cred(vp, attrnamespace, cred, td, VWRITE); 1073 if (error) 1074 return (error); 1075 1076 attribute = ufs_extattr_find_attr(ump, attrnamespace, name); 1077 if (!attribute) 1078 return (ENOATTR); 1079 1080 /* 1081 * Early rejection of invalid offsets/length. 1082 * Reject: any offset but 0 (replace) 1083 * Any size greater than attribute size limit 1084 */ 1085 if (uio->uio_offset != 0 || 1086 uio->uio_resid > attribute->uele_fileheader.uef_size) 1087 return (ENXIO); 1088 1089 /* 1090 * Find base offset of header in file based on file header size, and 1091 * data header size + maximum data size, indexed by inode number. 1092 */ 1093 base_offset = sizeof(struct ufs_extattr_fileheader) + 1094 ip->i_number * (sizeof(struct ufs_extattr_header) + 1095 attribute->uele_fileheader.uef_size); 1096 1097 /* 1098 * Write out a data header for the data. 1099 */ 1100 ueh.ueh_len = uio->uio_resid; 1101 ueh.ueh_flags = UFS_EXTATTR_ATTR_FLAG_INUSE; 1102 ueh.ueh_i_gen = ip->i_gen; 1103 local_aiov.iov_base = (caddr_t) &ueh; 1104 local_aiov.iov_len = sizeof(struct ufs_extattr_header); 1105 local_aio.uio_iov = &local_aiov; 1106 local_aio.uio_iovcnt = 1; 1107 local_aio.uio_rw = UIO_WRITE; 1108 local_aio.uio_segflg = UIO_SYSSPACE; 1109 local_aio.uio_td = td; 1110 local_aio.uio_offset = base_offset; 1111 local_aio.uio_resid = sizeof(struct ufs_extattr_header); 1112 1113 /* 1114 * Acquire locks. 1115 * 1116 * Don't need to get a lock on the backing file if the setattr is 1117 * being applied to the backing file, as the lock is already held. 1118 */ 1119 if (attribute->uele_backing_vnode != vp) 1120 vn_lock(attribute->uele_backing_vnode, LK_EXCLUSIVE | LK_RETRY); 1121 1122 ioflag = IO_NODELOCKED; 1123 if (ufs_extattr_sync) 1124 ioflag |= IO_SYNC; 1125 error = VOP_WRITE(attribute->uele_backing_vnode, &local_aio, ioflag, 1126 ump->um_extattr.uepm_ucred); 1127 if (error) 1128 goto vopunlock_exit; 1129 1130 if (local_aio.uio_resid != 0) { 1131 error = ENXIO; 1132 goto vopunlock_exit; 1133 } 1134 1135 /* 1136 * Write out user data. 1137 */ 1138 uio->uio_offset = base_offset + sizeof(struct ufs_extattr_header); 1139 1140 ioflag = IO_NODELOCKED; 1141 if (ufs_extattr_sync) 1142 ioflag |= IO_SYNC; 1143 error = VOP_WRITE(attribute->uele_backing_vnode, uio, ioflag, 1144 ump->um_extattr.uepm_ucred); 1145 1146 vopunlock_exit: 1147 uio->uio_offset = 0; 1148 1149 if (attribute->uele_backing_vnode != vp) 1150 VOP_UNLOCK(attribute->uele_backing_vnode); 1151 1152 return (error); 1153 } 1154 1155 /* 1156 * Real work associated with removing an extended attribute from a vnode. 1157 * Assumes the attribute lock has already been grabbed. 1158 */ 1159 static int 1160 ufs_extattr_rm(struct vnode *vp, int attrnamespace, const char *name, 1161 struct ucred *cred, struct thread *td) 1162 { 1163 struct ufs_extattr_list_entry *attribute; 1164 struct ufs_extattr_header ueh; 1165 struct iovec local_aiov; 1166 struct uio local_aio; 1167 struct mount *mp = vp->v_mount; 1168 struct ufsmount *ump = VFSTOUFS(mp); 1169 struct inode *ip = VTOI(vp); 1170 off_t base_offset; 1171 int error = 0, ioflag; 1172 1173 if (vp->v_mount->mnt_flag & MNT_RDONLY) 1174 return (EROFS); 1175 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) 1176 return (EOPNOTSUPP); 1177 if (!ufs_extattr_valid_attrname(attrnamespace, name)) 1178 return (EINVAL); 1179 1180 error = extattr_check_cred(vp, attrnamespace, cred, td, VWRITE); 1181 if (error) 1182 return (error); 1183 1184 attribute = ufs_extattr_find_attr(ump, attrnamespace, name); 1185 if (!attribute) 1186 return (ENOATTR); 1187 1188 /* 1189 * Find base offset of header in file based on file header size, and 1190 * data header size + maximum data size, indexed by inode number. 1191 */ 1192 base_offset = sizeof(struct ufs_extattr_fileheader) + 1193 ip->i_number * (sizeof(struct ufs_extattr_header) + 1194 attribute->uele_fileheader.uef_size); 1195 1196 /* 1197 * Check to see if currently defined. 1198 */ 1199 bzero(&ueh, sizeof(struct ufs_extattr_header)); 1200 1201 local_aiov.iov_base = (caddr_t) &ueh; 1202 local_aiov.iov_len = sizeof(struct ufs_extattr_header); 1203 local_aio.uio_iov = &local_aiov; 1204 local_aio.uio_iovcnt = 1; 1205 local_aio.uio_rw = UIO_READ; 1206 local_aio.uio_segflg = UIO_SYSSPACE; 1207 local_aio.uio_td = td; 1208 local_aio.uio_offset = base_offset; 1209 local_aio.uio_resid = sizeof(struct ufs_extattr_header); 1210 1211 /* 1212 * Don't need to get the lock on the backing vnode if the vnode we're 1213 * modifying is it, as we already hold the lock. 1214 */ 1215 if (attribute->uele_backing_vnode != vp) 1216 vn_lock(attribute->uele_backing_vnode, LK_EXCLUSIVE | LK_RETRY); 1217 1218 error = VOP_READ(attribute->uele_backing_vnode, &local_aio, 1219 IO_NODELOCKED, ump->um_extattr.uepm_ucred); 1220 if (error) 1221 goto vopunlock_exit; 1222 1223 /* Defined? */ 1224 if ((ueh.ueh_flags & UFS_EXTATTR_ATTR_FLAG_INUSE) == 0) { 1225 error = ENOATTR; 1226 goto vopunlock_exit; 1227 } 1228 1229 /* Valid for the current inode generation? */ 1230 if (ueh.ueh_i_gen != ip->i_gen) { 1231 /* 1232 * The inode itself has a different generation number than 1233 * the attribute data. For now, the best solution is to 1234 * coerce this to undefined, and let it get cleaned up by 1235 * the next write or extattrctl clean. 1236 */ 1237 printf("ufs_extattr_rm (%s): inode number inconsistency (%d, %jd)\n", 1238 mp->mnt_stat.f_mntonname, ueh.ueh_i_gen, (intmax_t)ip->i_gen); 1239 error = ENOATTR; 1240 goto vopunlock_exit; 1241 } 1242 1243 /* Flag it as not in use. */ 1244 ueh.ueh_flags = 0; 1245 ueh.ueh_len = 0; 1246 1247 local_aiov.iov_base = (caddr_t) &ueh; 1248 local_aiov.iov_len = sizeof(struct ufs_extattr_header); 1249 local_aio.uio_iov = &local_aiov; 1250 local_aio.uio_iovcnt = 1; 1251 local_aio.uio_rw = UIO_WRITE; 1252 local_aio.uio_segflg = UIO_SYSSPACE; 1253 local_aio.uio_td = td; 1254 local_aio.uio_offset = base_offset; 1255 local_aio.uio_resid = sizeof(struct ufs_extattr_header); 1256 1257 ioflag = IO_NODELOCKED; 1258 if (ufs_extattr_sync) 1259 ioflag |= IO_SYNC; 1260 error = VOP_WRITE(attribute->uele_backing_vnode, &local_aio, ioflag, 1261 ump->um_extattr.uepm_ucred); 1262 if (error) 1263 goto vopunlock_exit; 1264 1265 if (local_aio.uio_resid != 0) 1266 error = ENXIO; 1267 1268 vopunlock_exit: 1269 VOP_UNLOCK(attribute->uele_backing_vnode); 1270 1271 return (error); 1272 } 1273 1274 /* 1275 * Called by UFS when an inode is no longer active and should have its 1276 * attributes stripped. 1277 */ 1278 void 1279 ufs_extattr_vnode_inactive(struct vnode *vp) 1280 { 1281 struct ufs_extattr_list_entry *uele; 1282 struct mount *mp = vp->v_mount; 1283 struct ufsmount *ump = VFSTOUFS(mp); 1284 1285 /* 1286 * In that case, we cannot lock. We should not have any active vnodes 1287 * on the fs if this is not yet initialized but is going to be, so 1288 * this can go unlocked. 1289 */ 1290 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_INITIALIZED)) 1291 return; 1292 1293 ufs_extattr_uepm_lock(ump); 1294 1295 if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) { 1296 ufs_extattr_uepm_unlock(ump); 1297 return; 1298 } 1299 1300 LIST_FOREACH(uele, &ump->um_extattr.uepm_list, uele_entries) 1301 ufs_extattr_rm(vp, uele->uele_attrnamespace, 1302 uele->uele_attrname, NULL, curthread); 1303 1304 ufs_extattr_uepm_unlock(ump); 1305 } 1306 1307 #endif /* !UFS_EXTATTR */ 1308