vfs_export.c revision 191990
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: head/sys/kern/vfs_export.c 191990 2009-05-11 15:33:26Z attilio $"); 39 40#include <sys/param.h> 41#include <sys/dirent.h> 42#include <sys/domain.h> 43#include <sys/kernel.h> 44#include <sys/lock.h> 45#include <sys/malloc.h> 46#include <sys/mbuf.h> 47#include <sys/mount.h> 48#include <sys/mutex.h> 49#include <sys/rwlock.h> 50#include <sys/refcount.h> 51#include <sys/socket.h> 52#include <sys/systm.h> 53#include <sys/vnode.h> 54 55#include <net/radix.h> 56 57static MALLOC_DEFINE(M_NETADDR, "export_host", "Export host address structure"); 58 59static void vfs_free_addrlist(struct netexport *nep); 60static int vfs_free_netcred(struct radix_node *rn, void *w); 61static int vfs_hang_addrlist(struct mount *mp, struct netexport *nep, 62 struct export_args *argp); 63static struct netcred *vfs_export_lookup(struct mount *, struct sockaddr *); 64 65/* 66 * Network address lookup element 67 */ 68struct netcred { 69 struct radix_node netc_rnodes[2]; 70 int netc_exflags; 71 struct ucred *netc_anon; 72 int netc_numsecflavors; 73 int netc_secflavors[MAXSECFLAVORS]; 74}; 75 76/* 77 * Network export information 78 */ 79struct netexport { 80 struct netcred ne_defexported; /* Default export */ 81 struct radix_node_head *ne_rtable[AF_MAX+1]; /* Individual exports */ 82}; 83 84/* 85 * Build hash lists of net addresses and hang them off the mount point. 86 * Called by vfs_export() to set up the lists of export addresses. 87 */ 88static int 89vfs_hang_addrlist(struct mount *mp, struct netexport *nep, 90 struct export_args *argp) 91{ 92 register struct netcred *np; 93 register struct radix_node_head *rnh; 94 register int i; 95 struct radix_node *rn; 96 struct sockaddr *saddr, *smask = 0; 97 struct domain *dom; 98 int error; 99 100 /* 101 * XXX: This routine converts from a `struct xucred' 102 * (argp->ex_anon) to a `struct ucred' (np->netc_anon). This 103 * operation is questionable; for example, what should be done 104 * with fields like cr_uidinfo and cr_prison? Currently, this 105 * routine does not touch them (leaves them as NULL). 106 */ 107 if (argp->ex_anon.cr_version != XUCRED_VERSION) { 108 vfs_mount_error(mp, "ex_anon.cr_version: %d != %d", 109 argp->ex_anon.cr_version, XUCRED_VERSION); 110 return (EINVAL); 111 } 112 113 if (argp->ex_addrlen == 0) { 114 if (mp->mnt_flag & MNT_DEFEXPORTED) { 115 vfs_mount_error(mp, 116 "MNT_DEFEXPORTED already set for mount %p", mp); 117 return (EPERM); 118 } 119 np = &nep->ne_defexported; 120 np->netc_exflags = argp->ex_flags; 121 np->netc_anon = crget(); 122 np->netc_anon->cr_uid = argp->ex_anon.cr_uid; 123 np->netc_anon->cr_ngroups = argp->ex_anon.cr_ngroups; 124 bcopy(argp->ex_anon.cr_groups, np->netc_anon->cr_groups, 125 sizeof(np->netc_anon->cr_groups)); 126 np->netc_numsecflavors = argp->ex_numsecflavors; 127 bcopy(argp->ex_secflavors, np->netc_secflavors, 128 sizeof(np->netc_secflavors)); 129 MNT_ILOCK(mp); 130 mp->mnt_flag |= MNT_DEFEXPORTED; 131 MNT_IUNLOCK(mp); 132 return (0); 133 } 134 135#if MSIZE <= 256 136 if (argp->ex_addrlen > MLEN) { 137 vfs_mount_error(mp, "ex_addrlen %d is greater than %d", 138 argp->ex_addrlen, MLEN); 139 return (EINVAL); 140 } 141#endif 142 143 i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen; 144 np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK | M_ZERO); 145 saddr = (struct sockaddr *) (np + 1); 146 if ((error = copyin(argp->ex_addr, saddr, argp->ex_addrlen))) 147 goto out; 148 if (saddr->sa_family == AF_UNSPEC || saddr->sa_family > AF_MAX) { 149 error = EINVAL; 150 vfs_mount_error(mp, "Invalid saddr->sa_family: %d"); 151 goto out; 152 } 153 if (saddr->sa_len > argp->ex_addrlen) 154 saddr->sa_len = argp->ex_addrlen; 155 if (argp->ex_masklen) { 156 smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen); 157 error = copyin(argp->ex_mask, smask, argp->ex_masklen); 158 if (error) 159 goto out; 160 if (smask->sa_len > argp->ex_masklen) 161 smask->sa_len = argp->ex_masklen; 162 } 163 i = saddr->sa_family; 164 if ((rnh = nep->ne_rtable[i]) == NULL) { 165 /* 166 * Seems silly to initialize every AF when most are not used, 167 * do so on demand here 168 */ 169 for (dom = domains; dom; dom = dom->dom_next) { 170 KASSERT(((i == AF_INET) || (i == AF_INET6)), 171 ("unexpected protocol in vfs_hang_addrlist")); 172 if (dom->dom_family == i && dom->dom_rtattach) { 173 /* 174 * XXX MRT 175 * The INET and INET6 domains know the 176 * offset already. We don't need to send it 177 * So we just use it as a flag to say that 178 * we are or are not setting up a real routing 179 * table. Only IP and IPV6 need have this 180 * be 0 so all other protocols can stay the 181 * same (ABI compatible). 182 */ 183 dom->dom_rtattach( 184 (void **) &nep->ne_rtable[i], 0); 185 break; 186 } 187 } 188 if ((rnh = nep->ne_rtable[i]) == NULL) { 189 error = ENOBUFS; 190 vfs_mount_error(mp, "%s %s %d", 191 "Unable to initialize radix node head ", 192 "for address family", i); 193 goto out; 194 } 195 } 196 RADIX_NODE_HEAD_LOCK(rnh); 197 rn = (*rnh->rnh_addaddr)(saddr, smask, rnh, np->netc_rnodes); 198 RADIX_NODE_HEAD_UNLOCK(rnh); 199 if (rn == NULL || np != (struct netcred *)rn) { /* already exists */ 200 error = EPERM; 201 vfs_mount_error(mp, "Invalid radix node head, rn: %p %p", 202 rn, np); 203 goto out; 204 } 205 np->netc_exflags = argp->ex_flags; 206 np->netc_anon = crget(); 207 np->netc_anon->cr_uid = argp->ex_anon.cr_uid; 208 np->netc_anon->cr_ngroups = argp->ex_anon.cr_ngroups; 209 bcopy(argp->ex_anon.cr_groups, np->netc_anon->cr_groups, 210 sizeof(np->netc_anon->cr_groups)); 211 np->netc_numsecflavors = argp->ex_numsecflavors; 212 bcopy(argp->ex_secflavors, np->netc_secflavors, 213 sizeof(np->netc_secflavors)); 214 return (0); 215out: 216 free(np, M_NETADDR); 217 return (error); 218} 219 220/* Helper for vfs_free_addrlist. */ 221/* ARGSUSED */ 222static int 223vfs_free_netcred(struct radix_node *rn, void *w) 224{ 225 register struct radix_node_head *rnh = (struct radix_node_head *) w; 226 227 (*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh); 228 free(rn, M_NETADDR); 229 return (0); 230} 231 232/* 233 * Free the net address hash lists that are hanging off the mount points. 234 */ 235static void 236vfs_free_addrlist(struct netexport *nep) 237{ 238 register int i; 239 register struct radix_node_head *rnh; 240 241 for (i = 0; i <= AF_MAX; i++) 242 if ((rnh = nep->ne_rtable[i])) { 243 RADIX_NODE_HEAD_LOCK(rnh); 244 (*rnh->rnh_walktree) (rnh, vfs_free_netcred, rnh); 245 RADIX_NODE_HEAD_UNLOCK(rnh); 246 RADIX_NODE_HEAD_DESTROY(rnh); 247 free(rnh, M_RTABLE); 248 nep->ne_rtable[i] = NULL; /* not SMP safe XXX */ 249 } 250} 251 252/* 253 * High level function to manipulate export options on a mount point 254 * and the passed in netexport. 255 * Struct export_args *argp is the variable used to twiddle options, 256 * the structure is described in sys/mount.h 257 */ 258int 259vfs_export(struct mount *mp, struct export_args *argp) 260{ 261 struct netexport *nep; 262 int error; 263 264 if (argp->ex_numsecflavors < 0 265 || argp->ex_numsecflavors >= MAXSECFLAVORS) 266 return (EINVAL); 267 268 error = 0; 269 lockmgr(&mp->mnt_explock, LK_EXCLUSIVE, NULL); 270 nep = mp->mnt_export; 271 if (argp->ex_flags & MNT_DELEXPORT) { 272 if (nep == NULL) { 273 error = ENOENT; 274 goto out; 275 } 276 if (mp->mnt_flag & MNT_EXPUBLIC) { 277 vfs_setpublicfs(NULL, NULL, NULL); 278 MNT_ILOCK(mp); 279 mp->mnt_flag &= ~MNT_EXPUBLIC; 280 MNT_IUNLOCK(mp); 281 } 282 vfs_free_addrlist(nep); 283 mp->mnt_export = NULL; 284 free(nep, M_MOUNT); 285 nep = NULL; 286 MNT_ILOCK(mp); 287 mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED); 288 MNT_IUNLOCK(mp); 289 } 290 if (argp->ex_flags & MNT_EXPORTED) { 291 if (nep == NULL) { 292 nep = malloc(sizeof(struct netexport), M_MOUNT, M_WAITOK | M_ZERO); 293 mp->mnt_export = nep; 294 } 295 if (argp->ex_flags & MNT_EXPUBLIC) { 296 if ((error = vfs_setpublicfs(mp, nep, argp)) != 0) 297 goto out; 298 MNT_ILOCK(mp); 299 mp->mnt_flag |= MNT_EXPUBLIC; 300 MNT_IUNLOCK(mp); 301 } 302 if ((error = vfs_hang_addrlist(mp, nep, argp))) 303 goto out; 304 MNT_ILOCK(mp); 305 mp->mnt_flag |= MNT_EXPORTED; 306 MNT_IUNLOCK(mp); 307 } 308 309out: 310 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 311 /* 312 * Once we have executed the vfs_export() command, we do 313 * not want to keep the "export" option around in the 314 * options list, since that will cause subsequent MNT_UPDATE 315 * calls to fail. The export information is saved in 316 * mp->mnt_export, so we can safely delete the "export" mount option 317 * here. 318 */ 319 vfs_deleteopt(mp->mnt_optnew, "export"); 320 vfs_deleteopt(mp->mnt_opt, "export"); 321 return (error); 322} 323 324/* 325 * Set the publicly exported filesystem (WebNFS). Currently, only 326 * one public filesystem is possible in the spec (RFC 2054 and 2055) 327 */ 328int 329vfs_setpublicfs(struct mount *mp, struct netexport *nep, 330 struct export_args *argp) 331{ 332 int error; 333 struct vnode *rvp; 334 char *cp; 335 336 /* 337 * mp == NULL -> invalidate the current info, the FS is 338 * no longer exported. May be called from either vfs_export 339 * or unmount, so check if it hasn't already been done. 340 */ 341 if (mp == NULL) { 342 if (nfs_pub.np_valid) { 343 nfs_pub.np_valid = 0; 344 if (nfs_pub.np_index != NULL) { 345 free(nfs_pub.np_index, M_TEMP); 346 nfs_pub.np_index = NULL; 347 } 348 } 349 return (0); 350 } 351 352 /* 353 * Only one allowed at a time. 354 */ 355 if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount) 356 return (EBUSY); 357 358 /* 359 * Get real filehandle for root of exported FS. 360 */ 361 bzero(&nfs_pub.np_handle, sizeof(nfs_pub.np_handle)); 362 nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid; 363 364 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rvp))) 365 return (error); 366 367 if ((error = VOP_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid))) 368 return (error); 369 370 vput(rvp); 371 372 /* 373 * If an indexfile was specified, pull it in. 374 */ 375 if (argp->ex_indexfile != NULL) { 376 if (nfs_pub.np_index != NULL) 377 nfs_pub.np_index = malloc(MAXNAMLEN + 1, M_TEMP, 378 M_WAITOK); 379 error = copyinstr(argp->ex_indexfile, nfs_pub.np_index, 380 MAXNAMLEN, (size_t *)0); 381 if (!error) { 382 /* 383 * Check for illegal filenames. 384 */ 385 for (cp = nfs_pub.np_index; *cp; cp++) { 386 if (*cp == '/') { 387 error = EINVAL; 388 break; 389 } 390 } 391 } 392 if (error) { 393 free(nfs_pub.np_index, M_TEMP); 394 nfs_pub.np_index = NULL; 395 return (error); 396 } 397 } 398 399 nfs_pub.np_mount = mp; 400 nfs_pub.np_valid = 1; 401 return (0); 402} 403 404/* 405 * Used by the filesystems to determine if a given network address 406 * (passed in 'nam') is present in their exports list, returns a pointer 407 * to struct netcred so that the filesystem can examine it for 408 * access rights (read/write/etc). 409 */ 410static struct netcred * 411vfs_export_lookup(struct mount *mp, struct sockaddr *nam) 412{ 413 struct netexport *nep; 414 register struct netcred *np; 415 register struct radix_node_head *rnh; 416 struct sockaddr *saddr; 417 418 nep = mp->mnt_export; 419 if (nep == NULL) 420 return (NULL); 421 np = NULL; 422 if (mp->mnt_flag & MNT_EXPORTED) { 423 /* 424 * Lookup in the export list first. 425 */ 426 if (nam != NULL) { 427 saddr = nam; 428 rnh = nep->ne_rtable[saddr->sa_family]; 429 if (rnh != NULL) { 430 RADIX_NODE_HEAD_RLOCK(rnh); 431 np = (struct netcred *) 432 (*rnh->rnh_matchaddr)(saddr, rnh); 433 RADIX_NODE_HEAD_RUNLOCK(rnh); 434 if (np && np->netc_rnodes->rn_flags & RNF_ROOT) 435 np = NULL; 436 } 437 } 438 /* 439 * If no address match, use the default if it exists. 440 */ 441 if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED) 442 np = &nep->ne_defexported; 443 } 444 return (np); 445} 446 447/* 448 * XXX: This comment comes from the deprecated ufs_check_export() 449 * XXX: and may not entirely apply, but lacking something better: 450 * This is the generic part of fhtovp called after the underlying 451 * filesystem has validated the file handle. 452 * 453 * Verify that a host should have access to a filesystem. 454 */ 455 456int 457vfs_stdcheckexp(struct mount *mp, struct sockaddr *nam, int *extflagsp, 458 struct ucred **credanonp, int *numsecflavors, int **secflavors) 459{ 460 struct netcred *np; 461 462 lockmgr(&mp->mnt_explock, LK_SHARED, NULL); 463 np = vfs_export_lookup(mp, nam); 464 if (np == NULL) { 465 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 466 *credanonp = NULL; 467 return (EACCES); 468 } 469 *extflagsp = np->netc_exflags; 470 if ((*credanonp = np->netc_anon) != NULL) 471 crhold(*credanonp); 472 if (numsecflavors) 473 *numsecflavors = np->netc_numsecflavors; 474 if (secflavors) 475 *secflavors = np->netc_secflavors; 476 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL); 477 return (0); 478} 479 480