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#include <rpc/types.h> 65#include <rpc/auth.h> 66 67static MALLOC_DEFINE(M_NETADDR, "export_host", "Export host address structure"); 68 69#if defined(INET) || defined(INET6) 70static struct radix_node_head *vfs_create_addrlist_af( 71 struct radix_node_head **prnh, int off); 72#endif 73static void vfs_free_addrlist(struct netexport *nep); 74static int vfs_free_netcred(struct radix_node *rn, void *w); 75static void vfs_free_addrlist_af(struct radix_node_head **prnh); 76static int vfs_hang_addrlist(struct mount *mp, struct netexport *nep, 77 struct export_args *argp); 78static struct netcred *vfs_export_lookup(struct mount *, struct sockaddr *); 79 80/* 81 * Network address lookup element 82 */ 83struct netcred { 84 struct radix_node netc_rnodes[2]; 85 int netc_exflags; 86 struct ucred *netc_anon; 87 int netc_numsecflavors; 88 int netc_secflavors[MAXSECFLAVORS]; 89}; 90 91/* 92 * Network export information 93 */ 94struct netexport { 95 struct netcred ne_defexported; /* Default export */ 96 struct radix_node_head *ne4; 97 struct radix_node_head *ne6; 98}; 99 100/* 101 * Build hash lists of net addresses and hang them off the mount point. 102 * Called by vfs_export() to set up the lists of export addresses. 103 */ 104static int 105vfs_hang_addrlist(struct mount *mp, struct netexport *nep, 106 struct export_args *argp) 107{ 108 struct netcred *np; 109 struct radix_node_head *rnh; 110 int i; 111 struct radix_node *rn; 112 struct sockaddr *saddr, *smask = NULL; 113#if defined(INET6) || defined(INET) 114 int off; 115#endif 116 int error; 117 118 KASSERT(argp->ex_numsecflavors > 0, 119 ("%s: numsecflavors <= 0", __func__)); 120 KASSERT(argp->ex_numsecflavors < MAXSECFLAVORS, 121 ("%s: numsecflavors >= MAXSECFLAVORS", __func__)); 122 123 /* 124 * XXX: This routine converts from a `struct xucred' 125 * (argp->ex_anon) to a `struct ucred' (np->netc_anon). This 126 * operation is questionable; for example, what should be done 127 * with fields like cr_uidinfo and cr_prison? Currently, this 128 * routine does not touch them (leaves them as NULL). 129 */ 130 if (argp->ex_anon.cr_version != XUCRED_VERSION) { 131 vfs_mount_error(mp, "ex_anon.cr_version: %d != %d", 132 argp->ex_anon.cr_version, XUCRED_VERSION); 133 return (EINVAL); 134 } 135 136 if (argp->ex_addrlen == 0) { 137 if (mp->mnt_flag & MNT_DEFEXPORTED) { 138 vfs_mount_error(mp, 139 "MNT_DEFEXPORTED already set for mount %p", mp); 140 return (EPERM); 141 } 142 np = &nep->ne_defexported; 143 np->netc_exflags = argp->ex_flags; 144 np->netc_anon = crget(); 145 np->netc_anon->cr_uid = argp->ex_anon.cr_uid; 146 crsetgroups(np->netc_anon, argp->ex_anon.cr_ngroups, 147 argp->ex_anon.cr_groups); 148 np->netc_anon->cr_prison = &prison0; 149 prison_hold(np->netc_anon->cr_prison); 150 np->netc_numsecflavors = argp->ex_numsecflavors; 151 bcopy(argp->ex_secflavors, np->netc_secflavors, 152 sizeof(np->netc_secflavors)); 153 MNT_ILOCK(mp); 154 mp->mnt_flag |= MNT_DEFEXPORTED; 155 MNT_IUNLOCK(mp); 156 return (0); 157 } 158 159#if MSIZE <= 256 160 if (argp->ex_addrlen > MLEN) { 161 vfs_mount_error(mp, "ex_addrlen %d is greater than %d", 162 argp->ex_addrlen, MLEN); 163 return (EINVAL); 164 } 165#endif 166 167 i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen; 168 np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK | M_ZERO); 169 saddr = (struct sockaddr *) (np + 1); 170 if ((error = copyin(argp->ex_addr, saddr, argp->ex_addrlen))) 171 goto out; 172 if (saddr->sa_family == AF_UNSPEC || saddr->sa_family > AF_MAX) { 173 error = EINVAL; 174 vfs_mount_error(mp, "Invalid saddr->sa_family: %d"); 175 goto out; 176 } 177 if (saddr->sa_len > argp->ex_addrlen) 178 saddr->sa_len = argp->ex_addrlen; 179 if (argp->ex_masklen) { 180 smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen); 181 error = copyin(argp->ex_mask, smask, argp->ex_masklen); 182 if (error) 183 goto out; 184 if (smask->sa_len > argp->ex_masklen) 185 smask->sa_len = argp->ex_masklen; 186 } 187 rnh = NULL; 188 switch (saddr->sa_family) { 189#ifdef INET 190 case AF_INET: 191 if ((rnh = nep->ne4) == NULL) { 192 off = offsetof(struct sockaddr_in, sin_addr) << 3; 193 rnh = vfs_create_addrlist_af(&nep->ne4, off); 194 } 195 break; 196#endif 197#ifdef INET6 198 case AF_INET6: 199 if ((rnh = nep->ne6) == NULL) { 200 off = offsetof(struct sockaddr_in6, sin6_addr) << 3; 201 rnh = vfs_create_addrlist_af(&nep->ne6, off); 202 } 203 break; 204#endif 205 } 206 if (rnh == NULL) { 207 error = ENOBUFS; 208 vfs_mount_error(mp, "%s %s %d", 209 "Unable to initialize radix node head ", 210 "for address family", saddr->sa_family); 211 goto out; 212 } 213 RADIX_NODE_HEAD_LOCK(rnh); 214 rn = (*rnh->rnh_addaddr)(saddr, smask, &rnh->rh, np->netc_rnodes); 215 RADIX_NODE_HEAD_UNLOCK(rnh); 216 if (rn == NULL || np != (struct netcred *)rn) { /* already exists */ 217 error = EPERM; 218 vfs_mount_error(mp, 219 "netcred already exists for given addr/mask"); 220 goto out; 221 } 222 np->netc_exflags = argp->ex_flags; 223 np->netc_anon = crget(); 224 np->netc_anon->cr_uid = argp->ex_anon.cr_uid; 225 crsetgroups(np->netc_anon, argp->ex_anon.cr_ngroups, 226 argp->ex_anon.cr_groups); 227 np->netc_anon->cr_prison = &prison0; 228 prison_hold(np->netc_anon->cr_prison); 229 np->netc_numsecflavors = argp->ex_numsecflavors; 230 bcopy(argp->ex_secflavors, np->netc_secflavors, 231 sizeof(np->netc_secflavors)); 232 return (0); 233out: 234 free(np, M_NETADDR); 235 return (error); 236} 237 238/* Helper for vfs_free_addrlist. */ 239/* ARGSUSED */ 240static int 241vfs_free_netcred(struct radix_node *rn, void *w) 242{ 243 struct radix_node_head *rnh = (struct radix_node_head *) w; 244 struct ucred *cred; 245 246 (*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, &rnh->rh); 247 cred = ((struct netcred *)rn)->netc_anon; 248 if (cred != NULL) 249 crfree(cred); 250 free(rn, M_NETADDR); 251 return (0); 252} 253 254#if defined(INET) || defined(INET6) 255static struct radix_node_head * 256vfs_create_addrlist_af(struct radix_node_head **prnh, int off) 257{ 258 259 if (rn_inithead((void **)prnh, off) == 0) 260 return (NULL); 261 RADIX_NODE_HEAD_LOCK_INIT(*prnh); 262 return (*prnh); 263} 264#endif 265 266static void 267vfs_free_addrlist_af(struct radix_node_head **prnh) 268{ 269 struct radix_node_head *rnh; 270 271 rnh = *prnh; 272 RADIX_NODE_HEAD_LOCK(rnh); 273 (*rnh->rnh_walktree)(&rnh->rh, vfs_free_netcred, rnh); 274 RADIX_NODE_HEAD_UNLOCK(rnh); 275 RADIX_NODE_HEAD_DESTROY(rnh); 276 rn_detachhead((void **)prnh); 277 prnh = NULL; 278} 279 280/* 281 * Free the net address hash lists that are hanging off the mount points. 282 */ 283static void 284vfs_free_addrlist(struct netexport *nep) 285{ 286 struct ucred *cred; 287 288 if (nep->ne4 != NULL) 289 vfs_free_addrlist_af(&nep->ne4); 290 if (nep->ne6 != NULL) 291 vfs_free_addrlist_af(&nep->ne6); 292 293 cred = nep->ne_defexported.netc_anon; 294 if (cred != NULL) 295 crfree(cred); 296 297} 298 299/* 300 * High level function to manipulate export options on a mount point 301 * and the passed in netexport. 302 * Struct export_args *argp is the variable used to twiddle options, 303 * the structure is described in sys/mount.h 304 */ 305int 306vfs_export(struct mount *mp, struct export_args *argp) 307{ 308 struct netexport *nep; 309 int error; 310 311 if ((argp->ex_flags & (MNT_DELEXPORT | MNT_EXPORTED)) == 0) 312 return (EINVAL); 313 314 if ((argp->ex_flags & MNT_EXPORTED) != 0 && 315 (argp->ex_numsecflavors < 0 316 || argp->ex_numsecflavors >= MAXSECFLAVORS)) 317 return (EINVAL); 318 319 error = 0; 320 lockmgr(&mp->mnt_explock, LK_EXCLUSIVE, NULL); 321 nep = mp->mnt_export; 322 if (argp->ex_flags & MNT_DELEXPORT) { 323 if (nep == NULL) { 324 error = ENOENT; 325 goto out; 326 } 327 if (mp->mnt_flag & MNT_EXPUBLIC) { 328 vfs_setpublicfs(NULL, NULL, NULL); 329 MNT_ILOCK(mp); 330 mp->mnt_flag &= ~MNT_EXPUBLIC; 331 MNT_IUNLOCK(mp); 332 } 333 vfs_free_addrlist(nep); 334 mp->mnt_export = NULL; 335 free(nep, M_MOUNT); 336 nep = NULL; 337 MNT_ILOCK(mp); 338 mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED); 339 MNT_IUNLOCK(mp); 340 } 341 if (argp->ex_flags & MNT_EXPORTED) { 342 if (nep == NULL) { 343 nep = malloc(sizeof(struct netexport), M_MOUNT, M_WAITOK | M_ZERO); 344 mp->mnt_export = nep; 345 } 346 if (argp->ex_flags & MNT_EXPUBLIC) { 347 if ((error = vfs_setpublicfs(mp, nep, argp)) != 0) 348 goto out; 349 MNT_ILOCK(mp); 350 mp->mnt_flag |= MNT_EXPUBLIC; 351 MNT_IUNLOCK(mp); 352 } 353 if (argp->ex_numsecflavors == 0) { 354 argp->ex_numsecflavors = 1; 355 argp->ex_secflavors[0] = AUTH_SYS; 356 } 357 if ((error = vfs_hang_addrlist(mp, nep, argp))) 358 goto out; 359 MNT_ILOCK(mp); 360 mp->mnt_flag |= MNT_EXPORTED; 361 MNT_IUNLOCK(mp); 362 } 363 364out: 365 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 366 /* 367 * Once we have executed the vfs_export() command, we do 368 * not want to keep the "export" option around in the 369 * options list, since that will cause subsequent MNT_UPDATE 370 * calls to fail. The export information is saved in 371 * mp->mnt_export, so we can safely delete the "export" mount option 372 * here. 373 */ 374 vfs_deleteopt(mp->mnt_optnew, "export"); 375 vfs_deleteopt(mp->mnt_opt, "export"); 376 return (error); 377} 378 379/* 380 * Set the publicly exported filesystem (WebNFS). Currently, only 381 * one public filesystem is possible in the spec (RFC 2054 and 2055) 382 */ 383int 384vfs_setpublicfs(struct mount *mp, struct netexport *nep, 385 struct export_args *argp) 386{ 387 int error; 388 struct vnode *rvp; 389 char *cp; 390 391 /* 392 * mp == NULL -> invalidate the current info, the FS is 393 * no longer exported. May be called from either vfs_export 394 * or unmount, so check if it hasn't already been done. 395 */ 396 if (mp == NULL) { 397 if (nfs_pub.np_valid) { 398 nfs_pub.np_valid = 0; 399 if (nfs_pub.np_index != NULL) { 400 free(nfs_pub.np_index, M_TEMP); 401 nfs_pub.np_index = NULL; 402 } 403 } 404 return (0); 405 } 406 407 /* 408 * Only one allowed at a time. 409 */ 410 if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount) 411 return (EBUSY); 412 413 /* 414 * Get real filehandle for root of exported FS. 415 */ 416 bzero(&nfs_pub.np_handle, sizeof(nfs_pub.np_handle)); 417 nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid; 418 419 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rvp))) 420 return (error); 421 422 if ((error = VOP_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid))) 423 return (error); 424 425 vput(rvp); 426 427 /* 428 * If an indexfile was specified, pull it in. 429 */ 430 if (argp->ex_indexfile != NULL) { 431 if (nfs_pub.np_index == NULL) 432 nfs_pub.np_index = malloc(MAXNAMLEN + 1, M_TEMP, 433 M_WAITOK); 434 error = copyinstr(argp->ex_indexfile, nfs_pub.np_index, 435 MAXNAMLEN, (size_t *)0); 436 if (!error) { 437 /* 438 * Check for illegal filenames. 439 */ 440 for (cp = nfs_pub.np_index; *cp; cp++) { 441 if (*cp == '/') { 442 error = EINVAL; 443 break; 444 } 445 } 446 } 447 if (error) { 448 free(nfs_pub.np_index, M_TEMP); 449 nfs_pub.np_index = NULL; 450 return (error); 451 } 452 } 453 454 nfs_pub.np_mount = mp; 455 nfs_pub.np_valid = 1; 456 return (0); 457} 458 459/* 460 * Used by the filesystems to determine if a given network address 461 * (passed in 'nam') is present in their exports list, returns a pointer 462 * to struct netcred so that the filesystem can examine it for 463 * access rights (read/write/etc). 464 */ 465static struct netcred * 466vfs_export_lookup(struct mount *mp, struct sockaddr *nam) 467{ 468 RADIX_NODE_HEAD_RLOCK_TRACKER; 469 struct netexport *nep; 470 struct netcred *np = NULL; 471 struct radix_node_head *rnh; 472 struct sockaddr *saddr; 473 474 nep = mp->mnt_export; 475 if (nep == NULL) 476 return (NULL); 477 if ((mp->mnt_flag & MNT_EXPORTED) == 0) 478 return (NULL); 479 480 /* 481 * Lookup in the export list 482 */ 483 if (nam != NULL) { 484 saddr = nam; 485 rnh = NULL; 486 switch (saddr->sa_family) { 487 case AF_INET: 488 rnh = nep->ne4; 489 break; 490 case AF_INET6: 491 rnh = nep->ne6; 492 break; 493 } 494 if (rnh != NULL) { 495 RADIX_NODE_HEAD_RLOCK(rnh); 496 np = (struct netcred *) (*rnh->rnh_matchaddr)(saddr, &rnh->rh); 497 RADIX_NODE_HEAD_RUNLOCK(rnh); 498 if (np != NULL && (np->netc_rnodes->rn_flags & RNF_ROOT) != 0) 499 return (NULL); 500 } 501 } 502 503 /* 504 * If no address match, use the default if it exists. 505 */ 506 if (np == NULL && (mp->mnt_flag & MNT_DEFEXPORTED) != 0) 507 return (&nep->ne_defexported); 508 509 return (np); 510} 511 512/* 513 * XXX: This comment comes from the deprecated ufs_check_export() 514 * XXX: and may not entirely apply, but lacking something better: 515 * This is the generic part of fhtovp called after the underlying 516 * filesystem has validated the file handle. 517 * 518 * Verify that a host should have access to a filesystem. 519 */ 520 521int 522vfs_stdcheckexp(struct mount *mp, struct sockaddr *nam, int *extflagsp, 523 struct ucred **credanonp, int *numsecflavors, int **secflavors) 524{ 525 struct netcred *np; 526 527 lockmgr(&mp->mnt_explock, LK_SHARED, NULL); 528 np = vfs_export_lookup(mp, nam); 529 if (np == NULL) { 530 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 531 *credanonp = NULL; 532 return (EACCES); 533 } 534 *extflagsp = np->netc_exflags; 535 if ((*credanonp = np->netc_anon) != NULL) 536 crhold(*credanonp); 537 if (numsecflavors) { 538 *numsecflavors = np->netc_numsecflavors; 539 KASSERT(*numsecflavors > 0, 540 ("%s: numsecflavors <= 0", __func__)); 541 KASSERT(*numsecflavors < MAXSECFLAVORS, 542 ("%s: numsecflavors >= MAXSECFLAVORS", __func__)); 543 } 544 if (secflavors) 545 *secflavors = np->netc_secflavors; 546 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 547 return (0); 548} 549 550