1 /*- 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <sys/param.h> 41 #include <sys/dirent.h> 42 #include <sys/domain.h> 43 #include <sys/jail.h> 44 #include <sys/kernel.h> 45 #include <sys/lock.h> 46 #include <sys/malloc.h> 47 #include <sys/mbuf.h> 48 #include <sys/mount.h> 49 #include <sys/mutex.h> 50 #include <sys/rwlock.h> 51 #include <sys/refcount.h> 52 #include <sys/socket.h> 53 #include <sys/systm.h> 54 #include <sys/vnode.h> 55 56 #include <net/radix.h> 57 58 static MALLOC_DEFINE(M_NETADDR, "export_host", "Export host address structure"); 59 60 static void vfs_free_addrlist(struct netexport *nep); 61 static int vfs_free_netcred(struct radix_node *rn, void *w); 62 static int vfs_hang_addrlist(struct mount *mp, struct netexport *nep, 63 struct export_args *argp); 64 static struct netcred *vfs_export_lookup(struct mount *, struct sockaddr *); 65 66 /* 67 * Network address lookup element 68 */ 69 struct netcred { 70 struct radix_node netc_rnodes[2]; 71 int netc_exflags; 72 struct ucred *netc_anon; 73 int netc_numsecflavors; 74 int netc_secflavors[MAXSECFLAVORS]; 75 }; 76 77 /* 78 * Network export information 79 */ 80 struct netexport { 81 struct netcred ne_defexported; /* Default export */ 82 struct radix_node_head *ne_rtable[AF_MAX+1]; /* Individual exports */ 83 }; 84 85 /* 86 * Build hash lists of net addresses and hang them off the mount point. 87 * Called by vfs_export() to set up the lists of export addresses. 88 */ 89 static int 90 vfs_hang_addrlist(struct mount *mp, struct netexport *nep, 91 struct export_args *argp) 92 { 93 register struct netcred *np; 94 register struct radix_node_head *rnh; 95 register int i; 96 struct radix_node *rn; 97 struct sockaddr *saddr, *smask = 0; 98 struct domain *dom; 99 int error; 100 101 /* 102 * XXX: This routine converts from a `struct xucred' 103 * (argp->ex_anon) to a `struct ucred' (np->netc_anon). This 104 * operation is questionable; for example, what should be done 105 * with fields like cr_uidinfo and cr_prison? Currently, this 106 * routine does not touch them (leaves them as NULL). 107 */ 108 if (argp->ex_anon.cr_version != XUCRED_VERSION) { 109 vfs_mount_error(mp, "ex_anon.cr_version: %d != %d", 110 argp->ex_anon.cr_version, XUCRED_VERSION); 111 return (EINVAL); 112 } 113 114 if (argp->ex_addrlen == 0) { 115 if (mp->mnt_flag & MNT_DEFEXPORTED) { 116 vfs_mount_error(mp, 117 "MNT_DEFEXPORTED already set for mount %p", mp); 118 return (EPERM); 119 } 120 np = &nep->ne_defexported; 121 np->netc_exflags = argp->ex_flags; 122 np->netc_anon = crget(); 123 np->netc_anon->cr_uid = argp->ex_anon.cr_uid; 124 crsetgroups(np->netc_anon, argp->ex_anon.cr_ngroups, 125 argp->ex_anon.cr_groups); 126 np->netc_anon->cr_prison = &prison0; 127 prison_hold(np->netc_anon->cr_prison); 128 np->netc_numsecflavors = argp->ex_numsecflavors; 129 bcopy(argp->ex_secflavors, np->netc_secflavors, 130 sizeof(np->netc_secflavors)); 131 MNT_ILOCK(mp); 132 mp->mnt_flag |= MNT_DEFEXPORTED; 133 MNT_IUNLOCK(mp); 134 return (0); 135 } 136 137 #if MSIZE <= 256 138 if (argp->ex_addrlen > MLEN) { 139 vfs_mount_error(mp, "ex_addrlen %d is greater than %d", 140 argp->ex_addrlen, MLEN); 141 return (EINVAL); 142 } 143 #endif 144 145 i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen; 146 np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK | M_ZERO); 147 saddr = (struct sockaddr *) (np + 1); 148 if ((error = copyin(argp->ex_addr, saddr, argp->ex_addrlen))) 149 goto out; 150 if (saddr->sa_family == AF_UNSPEC || saddr->sa_family > AF_MAX) { 151 error = EINVAL; 152 vfs_mount_error(mp, "Invalid saddr->sa_family: %d"); 153 goto out; 154 } 155 if (saddr->sa_len > argp->ex_addrlen) 156 saddr->sa_len = argp->ex_addrlen; 157 if (argp->ex_masklen) { 158 smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen); 159 error = copyin(argp->ex_mask, smask, argp->ex_masklen); 160 if (error) 161 goto out; 162 if (smask->sa_len > argp->ex_masklen) 163 smask->sa_len = argp->ex_masklen; 164 } 165 i = saddr->sa_family; 166 if ((rnh = nep->ne_rtable[i]) == NULL) { 167 /* 168 * Seems silly to initialize every AF when most are not used, 169 * do so on demand here 170 */ 171 for (dom = domains; dom; dom = dom->dom_next) { 172 KASSERT(((i == AF_INET) || (i == AF_INET6)), 173 ("unexpected protocol in vfs_hang_addrlist")); 174 if (dom->dom_family == i && dom->dom_rtattach) { 175 /* 176 * XXX MRT 177 * The INET and INET6 domains know the 178 * offset already. We don't need to send it 179 * So we just use it as a flag to say that 180 * we are or are not setting up a real routing 181 * table. Only IP and IPV6 need have this 182 * be 0 so all other protocols can stay the 183 * same (ABI compatible). 184 */ 185 dom->dom_rtattach( 186 (void **) &nep->ne_rtable[i], 0); 187 break; 188 } 189 } 190 if ((rnh = nep->ne_rtable[i]) == NULL) { 191 error = ENOBUFS; 192 vfs_mount_error(mp, "%s %s %d", 193 "Unable to initialize radix node head ", 194 "for address family", i); 195 goto out; 196 } 197 } 198 RADIX_NODE_HEAD_LOCK(rnh); 199 rn = (*rnh->rnh_addaddr)(saddr, smask, rnh, np->netc_rnodes); 200 RADIX_NODE_HEAD_UNLOCK(rnh); 201 if (rn == NULL || np != (struct netcred *)rn) { /* already exists */ 202 error = EPERM; 203 vfs_mount_error(mp, "Invalid radix node head, rn: %p %p", 204 rn, np); 205 goto out; 206 } 207 np->netc_exflags = argp->ex_flags; 208 np->netc_anon = crget(); 209 np->netc_anon->cr_uid = argp->ex_anon.cr_uid; 210 crsetgroups(np->netc_anon, argp->ex_anon.cr_ngroups, 211 np->netc_anon->cr_groups); 212 np->netc_anon->cr_prison = &prison0; 213 prison_hold(np->netc_anon->cr_prison); 214 np->netc_numsecflavors = argp->ex_numsecflavors; 215 bcopy(argp->ex_secflavors, np->netc_secflavors, 216 sizeof(np->netc_secflavors)); 217 return (0); 218 out: 219 free(np, M_NETADDR); 220 return (error); 221 } 222 223 /* Helper for vfs_free_addrlist. */ 224 /* ARGSUSED */ 225 static int 226 vfs_free_netcred(struct radix_node *rn, void *w) 227 { 228 struct radix_node_head *rnh = (struct radix_node_head *) w; 229 struct ucred *cred; 230 231 (*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh); 232 cred = ((struct netcred *)rn)->netc_anon; 233 if (cred != NULL) 234 crfree(cred); 235 free(rn, M_NETADDR); 236 return (0); 237 } 238 239 /* 240 * Free the net address hash lists that are hanging off the mount points. 241 */ 242 static void 243 vfs_free_addrlist(struct netexport *nep) 244 { 245 int i; 246 struct radix_node_head *rnh; 247 struct ucred *cred; 248 249 for (i = 0; i <= AF_MAX; i++) { 250 if ((rnh = nep->ne_rtable[i])) { 251 RADIX_NODE_HEAD_LOCK(rnh); 252 (*rnh->rnh_walktree) (rnh, vfs_free_netcred, rnh); 253 RADIX_NODE_HEAD_UNLOCK(rnh); 254 RADIX_NODE_HEAD_DESTROY(rnh); 255 free(rnh, M_RTABLE); 256 nep->ne_rtable[i] = NULL; /* not SMP safe XXX */ 257 } 258 } 259 cred = nep->ne_defexported.netc_anon; 260 if (cred != NULL) 261 crfree(cred); 262 263 } 264 265 /* 266 * High level function to manipulate export options on a mount point 267 * and the passed in netexport. 268 * Struct export_args *argp is the variable used to twiddle options, 269 * the structure is described in sys/mount.h 270 */ 271 int 272 vfs_export(struct mount *mp, struct export_args *argp) 273 { 274 struct netexport *nep; 275 int error; 276 277 if (argp->ex_numsecflavors < 0 278 || argp->ex_numsecflavors >= MAXSECFLAVORS) 279 return (EINVAL); 280 281 error = 0; 282 lockmgr(&mp->mnt_explock, LK_EXCLUSIVE, NULL); 283 nep = mp->mnt_export; 284 if (argp->ex_flags & MNT_DELEXPORT) { 285 if (nep == NULL) { 286 error = ENOENT; 287 goto out; 288 } 289 if (mp->mnt_flag & MNT_EXPUBLIC) { 290 vfs_setpublicfs(NULL, NULL, NULL); 291 MNT_ILOCK(mp); 292 mp->mnt_flag &= ~MNT_EXPUBLIC; 293 MNT_IUNLOCK(mp); 294 } 295 vfs_free_addrlist(nep); 296 mp->mnt_export = NULL; 297 free(nep, M_MOUNT); 298 nep = NULL; 299 MNT_ILOCK(mp); 300 mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED); 301 MNT_IUNLOCK(mp); 302 } 303 if (argp->ex_flags & MNT_EXPORTED) { 304 if (nep == NULL) { 305 nep = malloc(sizeof(struct netexport), M_MOUNT, M_WAITOK | M_ZERO); 306 mp->mnt_export = nep; 307 } 308 if (argp->ex_flags & MNT_EXPUBLIC) { 309 if ((error = vfs_setpublicfs(mp, nep, argp)) != 0) 310 goto out; 311 MNT_ILOCK(mp); 312 mp->mnt_flag |= MNT_EXPUBLIC; 313 MNT_IUNLOCK(mp); 314 } 315 if ((error = vfs_hang_addrlist(mp, nep, argp))) 316 goto out; 317 MNT_ILOCK(mp); 318 mp->mnt_flag |= MNT_EXPORTED; 319 MNT_IUNLOCK(mp); 320 } 321 322 out: 323 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 324 /* 325 * Once we have executed the vfs_export() command, we do 326 * not want to keep the "export" option around in the 327 * options list, since that will cause subsequent MNT_UPDATE 328 * calls to fail. The export information is saved in 329 * mp->mnt_export, so we can safely delete the "export" mount option 330 * here. 331 */ 332 vfs_deleteopt(mp->mnt_optnew, "export"); 333 vfs_deleteopt(mp->mnt_opt, "export"); 334 return (error); 335 } 336 337 /* 338 * Set the publicly exported filesystem (WebNFS). Currently, only 339 * one public filesystem is possible in the spec (RFC 2054 and 2055) 340 */ 341 int 342 vfs_setpublicfs(struct mount *mp, struct netexport *nep, 343 struct export_args *argp) 344 { 345 int error; 346 struct vnode *rvp; 347 char *cp; 348 349 /* 350 * mp == NULL -> invalidate the current info, the FS is 351 * no longer exported. May be called from either vfs_export 352 * or unmount, so check if it hasn't already been done. 353 */ 354 if (mp == NULL) { 355 if (nfs_pub.np_valid) { 356 nfs_pub.np_valid = 0; 357 if (nfs_pub.np_index != NULL) { 358 free(nfs_pub.np_index, M_TEMP); 359 nfs_pub.np_index = NULL; 360 } 361 } 362 return (0); 363 } 364 365 /* 366 * Only one allowed at a time. 367 */ 368 if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount) 369 return (EBUSY); 370 371 /* 372 * Get real filehandle for root of exported FS. 373 */ 374 bzero(&nfs_pub.np_handle, sizeof(nfs_pub.np_handle)); 375 nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid; 376 377 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rvp))) 378 return (error); 379 380 if ((error = VOP_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid))) 381 return (error); 382 383 vput(rvp); 384 385 /* 386 * If an indexfile was specified, pull it in. 387 */ 388 if (argp->ex_indexfile != NULL) { 389 if (nfs_pub.np_index != NULL) 390 nfs_pub.np_index = malloc(MAXNAMLEN + 1, M_TEMP, 391 M_WAITOK); 392 error = copyinstr(argp->ex_indexfile, nfs_pub.np_index, 393 MAXNAMLEN, (size_t *)0); 394 if (!error) { 395 /* 396 * Check for illegal filenames. 397 */ 398 for (cp = nfs_pub.np_index; *cp; cp++) { 399 if (*cp == '/') { 400 error = EINVAL; 401 break; 402 } 403 } 404 } 405 if (error) { 406 free(nfs_pub.np_index, M_TEMP); 407 nfs_pub.np_index = NULL; 408 return (error); 409 } 410 } 411 412 nfs_pub.np_mount = mp; 413 nfs_pub.np_valid = 1; 414 return (0); 415 } 416 417 /* 418 * Used by the filesystems to determine if a given network address 419 * (passed in 'nam') is present in their exports list, returns a pointer 420 * to struct netcred so that the filesystem can examine it for 421 * access rights (read/write/etc). 422 */ 423 static struct netcred * 424 vfs_export_lookup(struct mount *mp, struct sockaddr *nam) 425 { 426 struct netexport *nep; 427 register struct netcred *np; 428 register struct radix_node_head *rnh; 429 struct sockaddr *saddr; 430 431 nep = mp->mnt_export; 432 if (nep == NULL) 433 return (NULL); 434 np = NULL; 435 if (mp->mnt_flag & MNT_EXPORTED) { 436 /* 437 * Lookup in the export list first. 438 */ 439 if (nam != NULL) { 440 saddr = nam; 441 rnh = nep->ne_rtable[saddr->sa_family]; 442 if (rnh != NULL) { 443 RADIX_NODE_HEAD_RLOCK(rnh); 444 np = (struct netcred *) 445 (*rnh->rnh_matchaddr)(saddr, rnh); 446 RADIX_NODE_HEAD_RUNLOCK(rnh); 447 if (np && np->netc_rnodes->rn_flags & RNF_ROOT) 448 np = NULL; 449 } 450 } 451 /* 452 * If no address match, use the default if it exists. 453 */ 454 if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED) 455 np = &nep->ne_defexported; 456 } 457 return (np); 458 } 459 460 /* 461 * XXX: This comment comes from the deprecated ufs_check_export() 462 * XXX: and may not entirely apply, but lacking something better: 463 * This is the generic part of fhtovp called after the underlying 464 * filesystem has validated the file handle. 465 * 466 * Verify that a host should have access to a filesystem. 467 */ 468 469 int 470 vfs_stdcheckexp(struct mount *mp, struct sockaddr *nam, int *extflagsp, 471 struct ucred **credanonp, int *numsecflavors, int **secflavors) 472 { 473 struct netcred *np; 474 475 lockmgr(&mp->mnt_explock, LK_SHARED, NULL); 476 np = vfs_export_lookup(mp, nam); 477 if (np == NULL) { 478 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 479 *credanonp = NULL; 480 return (EACCES); 481 } 482 *extflagsp = np->netc_exflags; 483 if ((*credanonp = np->netc_anon) != NULL) 484 crhold(*credanonp); 485 if (numsecflavors) 486 *numsecflavors = np->netc_numsecflavors; 487 if (secflavors) 488 *secflavors = np->netc_secflavors; 489 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 490 return (0); 491 } 492 493