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