1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_inet.h" 43 #include "opt_inet6.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/dirent.h> 48 #include <sys/jail.h> 49 #include <sys/kernel.h> 50 #include <sys/lock.h> 51 #include <sys/malloc.h> 52 #include <sys/mbuf.h> 53 #include <sys/mount.h> 54 #include <sys/mutex.h> 55 #include <sys/rmlock.h> 56 #include <sys/refcount.h> 57 #include <sys/signalvar.h> 58 #include <sys/socket.h> 59 #include <sys/vnode.h> 60 61 #include <netinet/in.h> 62 #include <net/radix.h> 63 64 static MALLOC_DEFINE(M_NETADDR, "export_host", "Export host address structure"); 65 66 #if defined(INET) || defined(INET6) 67 static struct radix_node_head *vfs_create_addrlist_af( 68 struct radix_node_head **prnh, int off); 69 #endif 70 static void vfs_free_addrlist(struct netexport *nep); 71 static int vfs_free_netcred(struct radix_node *rn, void *w); 72 static void vfs_free_addrlist_af(struct radix_node_head **prnh); 73 static int vfs_hang_addrlist(struct mount *mp, struct netexport *nep, 74 struct export_args *argp); 75 static struct netcred *vfs_export_lookup(struct mount *, struct sockaddr *); 76 77 /* 78 * Network address lookup element 79 */ 80 struct netcred { 81 struct radix_node netc_rnodes[2]; 82 int netc_exflags; 83 struct ucred *netc_anon; 84 int netc_numsecflavors; 85 int netc_secflavors[MAXSECFLAVORS]; 86 }; 87 88 /* 89 * Network export information 90 */ 91 struct netexport { 92 struct netcred ne_defexported; /* Default export */ 93 struct radix_node_head *ne4; 94 struct radix_node_head *ne6; 95 }; 96 97 /* 98 * Build hash lists of net addresses and hang them off the mount point. 99 * Called by vfs_export() to set up the lists of export addresses. 100 */ 101 static int 102 vfs_hang_addrlist(struct mount *mp, struct netexport *nep, 103 struct export_args *argp) 104 { 105 struct netcred *np; 106 struct radix_node_head *rnh; 107 int i; 108 struct radix_node *rn; 109 struct sockaddr *saddr, *smask = NULL; 110 #if defined(INET6) || defined(INET) 111 int off; 112 #endif 113 int error; 114 115 KASSERT(argp->ex_numsecflavors > 0, 116 ("%s: numsecflavors <= 0", __func__)); 117 KASSERT(argp->ex_numsecflavors < MAXSECFLAVORS, 118 ("%s: numsecflavors >= MAXSECFLAVORS", __func__)); 119 120 /* 121 * XXX: This routine converts from a `struct xucred' 122 * (argp->ex_anon) to a `struct ucred' (np->netc_anon). This 123 * operation is questionable; for example, what should be done 124 * with fields like cr_uidinfo and cr_prison? Currently, this 125 * routine does not touch them (leaves them as NULL). 126 */ 127 if (argp->ex_anon.cr_version != XUCRED_VERSION) { 128 vfs_mount_error(mp, "ex_anon.cr_version: %d != %d", 129 argp->ex_anon.cr_version, XUCRED_VERSION); 130 return (EINVAL); 131 } 132 133 if (argp->ex_addrlen == 0) { 134 if (mp->mnt_flag & MNT_DEFEXPORTED) { 135 vfs_mount_error(mp, 136 "MNT_DEFEXPORTED already set for mount %p", mp); 137 return (EPERM); 138 } 139 np = &nep->ne_defexported; 140 np->netc_exflags = argp->ex_flags; 141 np->netc_anon = crget(); 142 np->netc_anon->cr_uid = argp->ex_anon.cr_uid; 143 crsetgroups(np->netc_anon, argp->ex_anon.cr_ngroups, 144 argp->ex_anon.cr_groups); 145 np->netc_anon->cr_prison = &prison0; 146 prison_hold(np->netc_anon->cr_prison); 147 np->netc_numsecflavors = argp->ex_numsecflavors; 148 bcopy(argp->ex_secflavors, np->netc_secflavors, 149 sizeof(np->netc_secflavors)); 150 MNT_ILOCK(mp); 151 mp->mnt_flag |= MNT_DEFEXPORTED; 152 MNT_IUNLOCK(mp); 153 return (0); 154 } 155 156 #if MSIZE <= 256 157 if (argp->ex_addrlen > MLEN) { 158 vfs_mount_error(mp, "ex_addrlen %d is greater than %d", 159 argp->ex_addrlen, MLEN); 160 return (EINVAL); 161 } 162 #endif 163 164 i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen; 165 np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK | M_ZERO); 166 saddr = (struct sockaddr *) (np + 1); 167 if ((error = copyin(argp->ex_addr, saddr, argp->ex_addrlen))) 168 goto out; 169 if (saddr->sa_family == AF_UNSPEC || saddr->sa_family > AF_MAX) { 170 error = EINVAL; 171 vfs_mount_error(mp, "Invalid saddr->sa_family: %d"); 172 goto out; 173 } 174 if (saddr->sa_len > argp->ex_addrlen) 175 saddr->sa_len = argp->ex_addrlen; 176 if (argp->ex_masklen) { 177 smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen); 178 error = copyin(argp->ex_mask, smask, argp->ex_masklen); 179 if (error) 180 goto out; 181 if (smask->sa_len > argp->ex_masklen) 182 smask->sa_len = argp->ex_masklen; 183 } 184 rnh = NULL; 185 switch (saddr->sa_family) { 186 #ifdef INET 187 case AF_INET: 188 if ((rnh = nep->ne4) == NULL) { 189 off = offsetof(struct sockaddr_in, sin_addr) << 3; 190 rnh = vfs_create_addrlist_af(&nep->ne4, off); 191 } 192 break; 193 #endif 194 #ifdef INET6 195 case AF_INET6: 196 if ((rnh = nep->ne6) == NULL) { 197 off = offsetof(struct sockaddr_in6, sin6_addr) << 3; 198 rnh = vfs_create_addrlist_af(&nep->ne6, off); 199 } 200 break; 201 #endif 202 } 203 if (rnh == NULL) { 204 error = ENOBUFS; 205 vfs_mount_error(mp, "%s %s %d", 206 "Unable to initialize radix node head ", 207 "for address family", saddr->sa_family); 208 goto out; 209 } 210 RADIX_NODE_HEAD_LOCK(rnh); 211 rn = (*rnh->rnh_addaddr)(saddr, smask, &rnh->rh, np->netc_rnodes); 212 RADIX_NODE_HEAD_UNLOCK(rnh); 213 if (rn == NULL || np != (struct netcred *)rn) { /* already exists */ 214 error = EPERM; 215 vfs_mount_error(mp, 216 "netcred already exists for given addr/mask"); 217 goto out; 218 } 219 np->netc_exflags = argp->ex_flags; 220 np->netc_anon = crget(); 221 np->netc_anon->cr_uid = argp->ex_anon.cr_uid; 222 crsetgroups(np->netc_anon, argp->ex_anon.cr_ngroups, 223 argp->ex_anon.cr_groups); 224 np->netc_anon->cr_prison = &prison0; 225 prison_hold(np->netc_anon->cr_prison); 226 np->netc_numsecflavors = argp->ex_numsecflavors; 227 bcopy(argp->ex_secflavors, np->netc_secflavors, 228 sizeof(np->netc_secflavors)); 229 return (0); 230 out: 231 free(np, M_NETADDR); 232 return (error); 233 } 234 235 /* Helper for vfs_free_addrlist. */ 236 /* ARGSUSED */ 237 static int 238 vfs_free_netcred(struct radix_node *rn, void *w) 239 { 240 struct radix_node_head *rnh = (struct radix_node_head *) w; 241 struct ucred *cred; 242 243 (*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, &rnh->rh); 244 cred = ((struct netcred *)rn)->netc_anon; 245 if (cred != NULL) 246 crfree(cred); 247 free(rn, M_NETADDR); 248 return (0); 249 } 250 251 #if defined(INET) || defined(INET6) 252 static struct radix_node_head * 253 vfs_create_addrlist_af(struct radix_node_head **prnh, int off) 254 { 255 256 if (rn_inithead((void **)prnh, off) == 0) 257 return (NULL); 258 RADIX_NODE_HEAD_LOCK_INIT(*prnh); 259 return (*prnh); 260 } 261 #endif 262 263 static void 264 vfs_free_addrlist_af(struct radix_node_head **prnh) 265 { 266 struct radix_node_head *rnh; 267 268 rnh = *prnh; 269 RADIX_NODE_HEAD_LOCK(rnh); 270 (*rnh->rnh_walktree)(&rnh->rh, vfs_free_netcred, rnh); 271 RADIX_NODE_HEAD_UNLOCK(rnh); 272 RADIX_NODE_HEAD_DESTROY(rnh); 273 rn_detachhead((void **)prnh); 274 prnh = NULL; 275 } 276 277 /* 278 * Free the net address hash lists that are hanging off the mount points. 279 */ 280 static void 281 vfs_free_addrlist(struct netexport *nep) 282 { 283 struct ucred *cred; 284 285 if (nep->ne4 != NULL) 286 vfs_free_addrlist_af(&nep->ne4); 287 if (nep->ne6 != NULL) 288 vfs_free_addrlist_af(&nep->ne6); 289 290 cred = nep->ne_defexported.netc_anon; 291 if (cred != NULL) 292 crfree(cred); 293 294 } 295 296 /* 297 * High level function to manipulate export options on a mount point 298 * and the passed in netexport. 299 * Struct export_args *argp is the variable used to twiddle options, 300 * the structure is described in sys/mount.h 301 */ 302 int 303 vfs_export(struct mount *mp, struct export_args *argp) 304 { 305 struct netexport *nep; 306 int error; 307 308 if ((argp->ex_flags & (MNT_DELEXPORT | MNT_EXPORTED)) == 0) 309 return (EINVAL); 310 311 if ((argp->ex_flags & MNT_EXPORTED) != 0 && 312 (argp->ex_numsecflavors <= 0 313 || argp->ex_numsecflavors >= MAXSECFLAVORS)) 314 return (EINVAL); 315 316 error = 0; 317 lockmgr(&mp->mnt_explock, LK_EXCLUSIVE, NULL); 318 nep = mp->mnt_export; 319 if (argp->ex_flags & MNT_DELEXPORT) { 320 if (nep == NULL) { 321 error = ENOENT; 322 goto out; 323 } 324 if (mp->mnt_flag & MNT_EXPUBLIC) { 325 vfs_setpublicfs(NULL, NULL, NULL); 326 MNT_ILOCK(mp); 327 mp->mnt_flag &= ~MNT_EXPUBLIC; 328 MNT_IUNLOCK(mp); 329 } 330 vfs_free_addrlist(nep); 331 mp->mnt_export = NULL; 332 free(nep, M_MOUNT); 333 nep = NULL; 334 MNT_ILOCK(mp); 335 mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED); 336 MNT_IUNLOCK(mp); 337 } 338 if (argp->ex_flags & MNT_EXPORTED) { 339 if (nep == NULL) { 340 nep = malloc(sizeof(struct netexport), M_MOUNT, M_WAITOK | M_ZERO); 341 mp->mnt_export = nep; 342 } 343 if (argp->ex_flags & MNT_EXPUBLIC) { 344 if ((error = vfs_setpublicfs(mp, nep, argp)) != 0) 345 goto out; 346 MNT_ILOCK(mp); 347 mp->mnt_flag |= MNT_EXPUBLIC; 348 MNT_IUNLOCK(mp); 349 } 350 if ((error = vfs_hang_addrlist(mp, nep, argp))) 351 goto out; 352 MNT_ILOCK(mp); 353 mp->mnt_flag |= MNT_EXPORTED; 354 MNT_IUNLOCK(mp); 355 } 356 357 out: 358 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 359 /* 360 * Once we have executed the vfs_export() command, we do 361 * not want to keep the "export" option around in the 362 * options list, since that will cause subsequent MNT_UPDATE 363 * calls to fail. The export information is saved in 364 * mp->mnt_export, so we can safely delete the "export" mount option 365 * here. 366 */ 367 vfs_deleteopt(mp->mnt_optnew, "export"); 368 vfs_deleteopt(mp->mnt_opt, "export"); 369 return (error); 370 } 371 372 /* 373 * Set the publicly exported filesystem (WebNFS). Currently, only 374 * one public filesystem is possible in the spec (RFC 2054 and 2055) 375 */ 376 int 377 vfs_setpublicfs(struct mount *mp, struct netexport *nep, 378 struct export_args *argp) 379 { 380 int error; 381 struct vnode *rvp; 382 char *cp; 383 384 /* 385 * mp == NULL -> invalidate the current info, the FS is 386 * no longer exported. May be called from either vfs_export 387 * or unmount, so check if it hasn't already been done. 388 */ 389 if (mp == NULL) { 390 if (nfs_pub.np_valid) { 391 nfs_pub.np_valid = 0; 392 if (nfs_pub.np_index != NULL) { 393 free(nfs_pub.np_index, M_TEMP); 394 nfs_pub.np_index = NULL; 395 } 396 } 397 return (0); 398 } 399 400 /* 401 * Only one allowed at a time. 402 */ 403 if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount) 404 return (EBUSY); 405 406 /* 407 * Get real filehandle for root of exported FS. 408 */ 409 bzero(&nfs_pub.np_handle, sizeof(nfs_pub.np_handle)); 410 nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid; 411 412 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rvp))) 413 return (error); 414 415 if ((error = VOP_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid))) 416 return (error); 417 418 vput(rvp); 419 420 /* 421 * If an indexfile was specified, pull it in. 422 */ 423 if (argp->ex_indexfile != NULL) { 424 if (nfs_pub.np_index == NULL) 425 nfs_pub.np_index = malloc(MAXNAMLEN + 1, M_TEMP, 426 M_WAITOK); 427 error = copyinstr(argp->ex_indexfile, nfs_pub.np_index, 428 MAXNAMLEN, (size_t *)0); 429 if (!error) { 430 /* 431 * Check for illegal filenames. 432 */ 433 for (cp = nfs_pub.np_index; *cp; cp++) { 434 if (*cp == '/') { 435 error = EINVAL; 436 break; 437 } 438 } 439 } 440 if (error) { 441 free(nfs_pub.np_index, M_TEMP); 442 nfs_pub.np_index = NULL; 443 return (error); 444 } 445 } 446 447 nfs_pub.np_mount = mp; 448 nfs_pub.np_valid = 1; 449 return (0); 450 } 451 452 /* 453 * Used by the filesystems to determine if a given network address 454 * (passed in 'nam') is present in their exports list, returns a pointer 455 * to struct netcred so that the filesystem can examine it for 456 * access rights (read/write/etc). 457 */ 458 static struct netcred * 459 vfs_export_lookup(struct mount *mp, struct sockaddr *nam) 460 { 461 RADIX_NODE_HEAD_RLOCK_TRACKER; 462 struct netexport *nep; 463 struct netcred *np = NULL; 464 struct radix_node_head *rnh; 465 struct sockaddr *saddr; 466 467 nep = mp->mnt_export; 468 if (nep == NULL) 469 return (NULL); 470 if ((mp->mnt_flag & MNT_EXPORTED) == 0) 471 return (NULL); 472 473 /* 474 * Lookup in the export list 475 */ 476 if (nam != NULL) { 477 saddr = nam; 478 rnh = NULL; 479 switch (saddr->sa_family) { 480 case AF_INET: 481 rnh = nep->ne4; 482 break; 483 case AF_INET6: 484 rnh = nep->ne6; 485 break; 486 } 487 if (rnh != NULL) { 488 RADIX_NODE_HEAD_RLOCK(rnh); 489 np = (struct netcred *) (*rnh->rnh_matchaddr)(saddr, &rnh->rh); 490 RADIX_NODE_HEAD_RUNLOCK(rnh); 491 if (np != NULL && (np->netc_rnodes->rn_flags & RNF_ROOT) != 0) 492 return (NULL); 493 } 494 } 495 496 /* 497 * If no address match, use the default if it exists. 498 */ 499 if (np == NULL && (mp->mnt_flag & MNT_DEFEXPORTED) != 0) 500 return (&nep->ne_defexported); 501 502 return (np); 503 } 504 505 /* 506 * XXX: This comment comes from the deprecated ufs_check_export() 507 * XXX: and may not entirely apply, but lacking something better: 508 * This is the generic part of fhtovp called after the underlying 509 * filesystem has validated the file handle. 510 * 511 * Verify that a host should have access to a filesystem. 512 */ 513 514 int 515 vfs_stdcheckexp(struct mount *mp, struct sockaddr *nam, int *extflagsp, 516 struct ucred **credanonp, int *numsecflavors, int **secflavors) 517 { 518 struct netcred *np; 519 520 lockmgr(&mp->mnt_explock, LK_SHARED, NULL); 521 np = vfs_export_lookup(mp, nam); 522 if (np == NULL) { 523 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 524 *credanonp = NULL; 525 return (EACCES); 526 } 527 *extflagsp = np->netc_exflags; 528 if ((*credanonp = np->netc_anon) != NULL) 529 crhold(*credanonp); 530 if (numsecflavors) { 531 *numsecflavors = np->netc_numsecflavors; 532 KASSERT(*numsecflavors > 0, 533 ("%s: numsecflavors <= 0", __func__)); 534 KASSERT(*numsecflavors < MAXSECFLAVORS, 535 ("%s: numsecflavors >= MAXSECFLAVORS", __func__)); 536 } 537 if (secflavors) 538 *secflavors = np->netc_secflavors; 539 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 540 return (0); 541 } 542 543