nfs_export.c revision 1.57 1 /* $NetBSD: nfs_export.c,v 1.57 2013/11/23 14:20:46 christos Exp $ */
2
3 /*-
4 * Copyright (c) 1997, 1998, 2004, 2005, 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 * This code is derived from software contributed to The NetBSD Foundation
11 * by Charles M. Hannum.
12 * This code is derived from software contributed to The NetBSD Foundation
13 * by Julio M. Merino Vidal.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
26 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
27 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
28 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37 /*
38 * Copyright (c) 1989, 1993
39 * The Regents of the University of California. All rights reserved.
40 * (c) UNIX System Laboratories, Inc.
41 * All or some portions of this file are derived from material licensed
42 * to the University of California by American Telephone and Telegraph
43 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
44 * the permission of UNIX System Laboratories, Inc.
45 *
46 * Redistribution and use in source and binary forms, with or without
47 * modification, are permitted provided that the following conditions
48 * are met:
49 * 1. Redistributions of source code must retain the above copyright
50 * notice, this list of conditions and the following disclaimer.
51 * 2. Redistributions in binary form must reproduce the above copyright
52 * notice, this list of conditions and the following disclaimer in the
53 * documentation and/or other materials provided with the distribution.
54 * 3. Neither the name of the University nor the names of its contributors
55 * may be used to endorse or promote products derived from this software
56 * without specific prior written permission.
57 *
58 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
59 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
60 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
61 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
62 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
63 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
64 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
65 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
66 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
67 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
68 * SUCH DAMAGE.
69 *
70 * @(#)vfs_subr.c 8.13 (Berkeley) 4/18/94
71 */
72
73 /*
74 * VFS exports list management.
75 *
76 * Lock order: vfs_busy -> mnt_updating -> netexport_lock.
77 */
78
79 #include <sys/cdefs.h>
80 __KERNEL_RCSID(0, "$NetBSD: nfs_export.c,v 1.57 2013/11/23 14:20:46 christos Exp $");
81
82 #include <sys/param.h>
83 #include <sys/systm.h>
84 #include <sys/kernel.h>
85 #include <sys/queue.h>
86 #include <sys/proc.h>
87 #include <sys/mount.h>
88 #include <sys/vnode.h>
89 #include <sys/namei.h>
90 #include <sys/errno.h>
91 #include <sys/malloc.h>
92 #include <sys/domain.h>
93 #include <sys/mbuf.h>
94 #include <sys/dirent.h>
95 #include <sys/socket.h> /* XXX for AF_MAX */
96 #include <sys/kauth.h>
97
98 #include <net/radix.h>
99
100 #include <netinet/in.h>
101
102 #include <nfs/rpcv2.h>
103 #include <nfs/nfsproto.h>
104 #include <nfs/nfs.h>
105 #include <nfs/nfs_var.h>
106
107 /*
108 * Network address lookup element.
109 */
110 struct netcred {
111 struct radix_node netc_rnodes[2];
112 int netc_refcnt;
113 int netc_exflags;
114 kauth_cred_t netc_anon;
115 };
116
117 /*
118 * Network export information.
119 */
120 struct netexport {
121 TAILQ_ENTRY(netexport) ne_list;
122 struct mount *ne_mount;
123 struct netcred ne_defexported; /* Default export */
124 struct radix_node_head *ne_rtable[AF_MAX+1]; /* Individual exports */
125 };
126 TAILQ_HEAD(, netexport) netexport_list =
127 TAILQ_HEAD_INITIALIZER(netexport_list);
128
129 /* Publicly exported file system. */
130 struct nfs_public nfs_pub;
131
132 /*
133 * Local prototypes.
134 */
135 static int init_exports(struct mount *, struct netexport **);
136 static int hang_addrlist(struct mount *, struct netexport *,
137 const struct export_args *);
138 static int sacheck(struct sockaddr *);
139 static int free_netcred(struct radix_node *, void *);
140 static int export(struct netexport *, const struct export_args *);
141 static int setpublicfs(struct mount *, struct netexport *,
142 const struct export_args *);
143 static struct netcred *netcred_lookup(struct netexport *, struct mbuf *);
144 static struct netexport *netexport_lookup(const struct mount *);
145 static struct netexport *netexport_lookup_byfsid(const fsid_t *);
146 static void netexport_clear(struct netexport *);
147 static void netexport_insert(struct netexport *);
148 static void netexport_remove(struct netexport *);
149 static void netexport_wrlock(void);
150 static void netexport_wrunlock(void);
151 static int nfs_export_update_30(struct mount *mp, const char *path, void *);
152
153 static krwlock_t netexport_lock;
154
155 /*
156 * PUBLIC INTERFACE
157 */
158
159 /*
160 * Declare and initialize the file system export hooks.
161 */
162 static void netexport_unmount(struct mount *);
163
164 struct vfs_hooks nfs_export_hooks = {
165 { NULL, NULL },
166 .vh_unmount = netexport_unmount,
167 .vh_reexport = nfs_export_update_30,
168 };
169
170 /*
171 * VFS unmount hook for NFS exports.
172 *
173 * Releases NFS exports list resources if the given mount point has some.
174 * As allocation happens lazily, it may be that it doesn't have this
175 * information, although it theoretically should.
176 */
177 static void
178 netexport_unmount(struct mount *mp)
179 {
180 struct netexport *ne;
181
182 KASSERT(mp != NULL);
183
184 netexport_wrlock();
185 ne = netexport_lookup(mp);
186 if (ne == NULL) {
187 netexport_wrunlock();
188 return;
189 }
190 netexport_clear(ne);
191 netexport_remove(ne);
192 netexport_wrunlock();
193 kmem_free(ne, sizeof(*ne));
194 }
195
196 void
197 netexport_init(void)
198 {
199
200 rw_init(&netexport_lock);
201 }
202
203 void
204 netexport_fini(void)
205 {
206 struct netexport *ne;
207 struct mount *mp;
208 int error;
209
210 while (!TAILQ_EMPTY(&netexport_list)) {
211 netexport_wrlock();
212 ne = TAILQ_FIRST(&netexport_list);
213 mp = ne->ne_mount;
214 error = vfs_busy(mp, NULL);
215 netexport_wrunlock();
216 if (error != 0) {
217 kpause("nfsfini", false, hz, NULL);
218 continue;
219 }
220 mutex_enter(&mp->mnt_updating); /* mnt_flag */
221 netexport_unmount(mp);
222 mutex_exit(&mp->mnt_updating); /* mnt_flag */
223 vfs_unbusy(mp, false, NULL);
224 }
225 rw_destroy(&netexport_lock);
226 }
227
228
229 /*
230 * Atomically set the NFS exports list of the given file system, replacing
231 * it with a new list of entries.
232 *
233 * Returns zero on success or an appropriate error code otherwise.
234 *
235 * Helper function for the nfssvc(2) system call (NFSSVC_SETEXPORTSLIST
236 * command).
237 */
238 int
239 mountd_set_exports_list(const struct mountd_exports_list *mel, struct lwp *l,
240 struct mount *nmp)
241 {
242 int error;
243 #ifdef notyet
244 /* XXX: See below to see the reason why this is disabled. */
245 size_t i;
246 #endif
247 struct mount *mp;
248 struct netexport *ne;
249 struct pathbuf *pb;
250 struct nameidata nd;
251 struct vnode *vp;
252 size_t fid_size;
253
254 if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_NFS,
255 KAUTH_REQ_NETWORK_NFS_EXPORT, NULL, NULL, NULL) != 0)
256 return EPERM;
257
258 /* Look up the file system path. */
259 error = pathbuf_copyin(mel->mel_path, &pb);
260 if (error) {
261 return error;
262 }
263 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, pb);
264 error = namei(&nd);
265 if (error != 0) {
266 pathbuf_destroy(pb);
267 return error;
268 }
269 vp = nd.ni_vp;
270 mp = vp->v_mount;
271 KASSERT(nmp == NULL || nmp == mp);
272 pathbuf_destroy(pb);
273
274 /*
275 * Make sure the file system can do vptofh. If the file system
276 * knows the handle's size, just trust it's able to do the
277 * actual translation also (otherwise we should check fhtovp
278 * also, and that's getting a wee bit ridiculous).
279 */
280 fid_size = 0;
281 if ((error = VFS_VPTOFH(vp, NULL, &fid_size)) != E2BIG) {
282 vput(vp);
283 return EOPNOTSUPP;
284 }
285
286 /* Mark the file system busy. */
287 error = vfs_busy(mp, NULL);
288 vput(vp);
289 if (error != 0)
290 return error;
291 if (nmp == NULL)
292 mutex_enter(&mp->mnt_updating); /* mnt_flag */
293 netexport_wrlock();
294 ne = netexport_lookup(mp);
295 if (ne == NULL) {
296 error = init_exports(mp, &ne);
297 if (error != 0) {
298 goto out;
299 }
300 }
301
302 KASSERT(ne != NULL);
303 KASSERT(ne->ne_mount == mp);
304
305 /*
306 * XXX: The part marked as 'notyet' works fine from the kernel's
307 * point of view, in the sense that it is able to atomically update
308 * the complete exports list for a file system. However, supporting
309 * this in mountd(8) requires a lot of work; so, for now, keep the
310 * old behavior of updating a single entry per call.
311 *
312 * When mountd(8) is fixed, just remove the second branch of this
313 * preprocessor conditional and enable the first one.
314 */
315 #ifdef notyet
316 netexport_clear(ne);
317 for (i = 0; error == 0 && i < mel->mel_nexports; i++)
318 error = export(ne, &mel->mel_exports[i]);
319 #else
320 if (mel->mel_nexports == 0)
321 netexport_clear(ne);
322 else if (mel->mel_nexports == 1)
323 error = export(ne, &mel->mel_exports[0]);
324 else {
325 printf("%s: Cannot set more than one "
326 "entry at once (unimplemented)\n", __func__);
327 error = EOPNOTSUPP;
328 }
329 #endif
330
331 out:
332 netexport_wrunlock();
333 if (nmp == NULL)
334 mutex_exit(&mp->mnt_updating); /* mnt_flag */
335 vfs_unbusy(mp, false, NULL);
336 return error;
337 }
338
339 static void
340 netexport_insert(struct netexport *ne)
341 {
342
343 TAILQ_INSERT_HEAD(&netexport_list, ne, ne_list);
344 }
345
346 static void
347 netexport_remove(struct netexport *ne)
348 {
349
350 TAILQ_REMOVE(&netexport_list, ne, ne_list);
351 }
352
353 static struct netexport *
354 netexport_lookup(const struct mount *mp)
355 {
356 struct netexport *ne;
357
358 TAILQ_FOREACH(ne, &netexport_list, ne_list) {
359 if (ne->ne_mount == mp) {
360 goto done;
361 }
362 }
363 ne = NULL;
364 done:
365 return ne;
366 }
367
368 static struct netexport *
369 netexport_lookup_byfsid(const fsid_t *fsid)
370 {
371 struct netexport *ne;
372
373 TAILQ_FOREACH(ne, &netexport_list, ne_list) {
374 const struct mount *mp = ne->ne_mount;
375
376 if (mp->mnt_stat.f_fsidx.__fsid_val[0] == fsid->__fsid_val[0] &&
377 mp->mnt_stat.f_fsidx.__fsid_val[1] == fsid->__fsid_val[1]) {
378 goto done;
379 }
380 }
381 ne = NULL;
382 done:
383
384 return ne;
385 }
386
387 /*
388 * Check if the file system specified by the 'mp' mount structure is
389 * exported to a client with 'anon' anonymous credentials. The 'mb'
390 * argument is an mbuf containing the network address of the client.
391 * The return parameters for the export flags for the client are returned
392 * in the address specified by 'wh'.
393 *
394 * This function is used exclusively by the NFS server. It is generally
395 * invoked before VFS_FHTOVP to validate that a client has access to the
396 * file system.
397 */
398
399 int
400 netexport_check(const fsid_t *fsid, struct mbuf *mb, struct mount **mpp,
401 int *wh, kauth_cred_t *anon)
402 {
403 struct netexport *ne;
404 struct netcred *np;
405
406 ne = netexport_lookup_byfsid(fsid);
407 if (ne == NULL) {
408 return EACCES;
409 }
410 np = netcred_lookup(ne, mb);
411 if (np == NULL) {
412 return EACCES;
413 }
414
415 *mpp = ne->ne_mount;
416 *wh = np->netc_exflags;
417 *anon = np->netc_anon;
418
419 return 0;
420 }
421
422 /*
423 * Handles legacy export requests. In this case, the export information
424 * is hardcoded in a specific place of the mount arguments structure (given
425 * in data); the request for an update is given through the fspec field
426 * (also in a known location), which must be a null pointer.
427 *
428 * Returns EJUSTRETURN if the given command was not a export request.
429 * Otherwise, returns 0 on success or an appropriate error code otherwise.
430 */
431 static int
432 nfs_export_update_30(struct mount *mp, const char *path, void *data)
433 {
434 struct mountd_exports_list mel;
435 struct mnt_export_args30 *args;
436
437 args = data;
438 mel.mel_path = path;
439
440 if (args->fspec != NULL)
441 return EJUSTRETURN;
442
443 if (args->eargs.ex_flags & 0x00020000) {
444 /* Request to delete exports. The mask above holds the
445 * value that used to be in MNT_DELEXPORT. */
446 mel.mel_nexports = 0;
447 } else {
448 /*
449 * The following code assumes export_args has not
450 * changed since export_args30, so check that.
451 */
452 __CTASSERT(sizeof(args->eargs) == sizeof(*mel.mel_exports));
453
454 mel.mel_nexports = 1;
455 mel.mel_exports = (void *)&args->eargs;
456 }
457
458 return mountd_set_exports_list(&mel, curlwp, mp);
459 }
460
461 /*
462 * INTERNAL FUNCTIONS
463 */
464
465 /*
466 * Initializes NFS exports for the mountpoint given in 'mp'.
467 * If successful, returns 0 and sets *nep to the address of the new
468 * netexport item; otherwise returns an appropriate error code
469 * and *nep remains unmodified.
470 */
471 static int
472 init_exports(struct mount *mp, struct netexport **nep)
473 {
474 int error;
475 struct export_args ea;
476 struct netexport *ne;
477
478 KASSERT(mp != NULL);
479
480 /* Ensure that we do not already have this mount point. */
481 KASSERT(netexport_lookup(mp) == NULL);
482
483 ne = kmem_zalloc(sizeof(*ne), KM_SLEEP);
484 ne->ne_mount = mp;
485
486 /* Set the default export entry. Handled internally by export upon
487 * first call. */
488 memset(&ea, 0, sizeof(ea));
489 ea.ex_root = -2;
490 if (mp->mnt_flag & MNT_RDONLY)
491 ea.ex_flags |= MNT_EXRDONLY;
492 error = export(ne, &ea);
493 if (error != 0) {
494 kmem_free(ne, sizeof(*ne));
495 } else {
496 netexport_insert(ne);
497 *nep = ne;
498 }
499
500 return error;
501 }
502
503 /*
504 * Build hash lists of net addresses and hang them off the mount point.
505 * Called by export() to set up a new entry in the lists of export
506 * addresses.
507 */
508 static int
509 hang_addrlist(struct mount *mp, struct netexport *nep,
510 const struct export_args *argp)
511 {
512 int error, i;
513 struct netcred *np, *enp;
514 struct radix_node_head *rnh;
515 struct sockaddr *saddr, *smask;
516 struct domain *dom;
517
518 smask = NULL;
519
520 if (argp->ex_addrlen == 0) {
521 if (mp->mnt_flag & MNT_DEFEXPORTED)
522 return EPERM;
523 np = &nep->ne_defexported;
524 KASSERT(np->netc_anon == NULL);
525 np->netc_anon = kauth_cred_alloc();
526 np->netc_exflags = argp->ex_flags;
527 kauth_uucred_to_cred(np->netc_anon, &argp->ex_anon);
528 mp->mnt_flag |= MNT_DEFEXPORTED;
529 return 0;
530 }
531
532 if (argp->ex_addrlen > MLEN || argp->ex_masklen > MLEN)
533 return EINVAL;
534
535 i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
536 np = malloc(i, M_NETADDR, M_WAITOK | M_ZERO);
537 np->netc_anon = kauth_cred_alloc();
538 saddr = (struct sockaddr *)(np + 1);
539 error = copyin(argp->ex_addr, saddr, argp->ex_addrlen);
540 if (error)
541 goto out;
542 if (saddr->sa_len > argp->ex_addrlen)
543 saddr->sa_len = argp->ex_addrlen;
544 if (sacheck(saddr) == -1)
545 return EINVAL;
546 if (argp->ex_masklen) {
547 smask = (struct sockaddr *)((char *)saddr + argp->ex_addrlen);
548 error = copyin(argp->ex_mask, smask, argp->ex_masklen);
549 if (error)
550 goto out;
551 if (smask->sa_len > argp->ex_masklen)
552 smask->sa_len = argp->ex_masklen;
553 if (smask->sa_family != saddr->sa_family)
554 return EINVAL;
555 if (sacheck(smask) == -1)
556 return EINVAL;
557 }
558 i = saddr->sa_family;
559 if ((rnh = nep->ne_rtable[i]) == 0) {
560 /*
561 * Seems silly to initialize every AF when most are not
562 * used, do so on demand here.
563 */
564 DOMAIN_FOREACH(dom) {
565 if (dom->dom_family == i && dom->dom_rtattach) {
566 rn_inithead((void **)&nep->ne_rtable[i],
567 dom->dom_rtoffset);
568 break;
569 }
570 }
571 if ((rnh = nep->ne_rtable[i]) == 0) {
572 error = ENOBUFS;
573 goto out;
574 }
575 }
576
577 enp = (struct netcred *)(*rnh->rnh_addaddr)(saddr, smask, rnh,
578 np->netc_rnodes);
579 if (enp != np) {
580 if (enp == NULL) {
581 enp = (struct netcred *)(*rnh->rnh_lookup)(saddr,
582 smask, rnh);
583 if (enp == NULL) {
584 error = EPERM;
585 goto out;
586 }
587 } else
588 enp->netc_refcnt++;
589
590 goto check;
591 } else
592 enp->netc_refcnt = 1;
593
594 np->netc_exflags = argp->ex_flags;
595 kauth_uucred_to_cred(np->netc_anon, &argp->ex_anon);
596 return 0;
597 check:
598 if (enp->netc_exflags != argp->ex_flags ||
599 kauth_cred_uucmp(enp->netc_anon, &argp->ex_anon) != 0)
600 error = EPERM;
601 else
602 error = 0;
603 out:
604 KASSERT(np->netc_anon != NULL);
605 kauth_cred_free(np->netc_anon);
606 free(np, M_NETADDR);
607 return error;
608 }
609
610 /*
611 * Ensure that the address stored in 'sa' is valid.
612 * Returns zero on success, otherwise -1.
613 */
614 static int
615 sacheck(struct sockaddr *sa)
616 {
617
618 switch (sa->sa_family) {
619 case AF_INET: {
620 struct sockaddr_in *sin = (struct sockaddr_in *)sa;
621 char *p = (char *)sin->sin_zero;
622 size_t i;
623
624 if (sin->sin_len != sizeof(*sin))
625 return -1;
626 if (sin->sin_port != 0)
627 return -1;
628 for (i = 0; i < sizeof(sin->sin_zero); i++)
629 if (*p++ != '\0')
630 return -1;
631 return 0;
632 }
633 case AF_INET6: {
634 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
635
636 if (sin6->sin6_len != sizeof(*sin6))
637 return -1;
638 if (sin6->sin6_port != 0)
639 return -1;
640 return 0;
641 }
642 default:
643 return -1;
644 }
645 }
646
647 /*
648 * Free the netcred object pointed to by the 'rn' radix node.
649 * 'w' holds a pointer to the radix tree head.
650 */
651 static int
652 free_netcred(struct radix_node *rn, void *w)
653 {
654 struct radix_node_head *rnh = (struct radix_node_head *)w;
655 struct netcred *np = (struct netcred *)(void *)rn;
656
657 (*rnh->rnh_deladdr)(rn->rn_key, rn->rn_mask, rnh);
658 if (--(np->netc_refcnt) <= 0) {
659 KASSERT(np->netc_anon != NULL);
660 kauth_cred_free(np->netc_anon);
661 free(np, M_NETADDR);
662 }
663 return 0;
664 }
665
666 /*
667 * Clears the exports list for a given file system.
668 */
669 static void
670 netexport_clear(struct netexport *ne)
671 {
672 struct radix_node_head *rnh;
673 struct mount *mp = ne->ne_mount;
674 int i;
675
676 if (mp->mnt_flag & MNT_EXPUBLIC) {
677 setpublicfs(NULL, NULL, NULL);
678 mp->mnt_flag &= ~MNT_EXPUBLIC;
679 }
680
681 for (i = 0; i <= AF_MAX; i++) {
682 if ((rnh = ne->ne_rtable[i]) != NULL) {
683 rn_walktree(rnh, free_netcred, rnh);
684 free(rnh, M_RTABLE);
685 ne->ne_rtable[i] = NULL;
686 }
687 }
688
689 if ((mp->mnt_flag & MNT_DEFEXPORTED) != 0) {
690 struct netcred *np = &ne->ne_defexported;
691
692 KASSERT(np->netc_anon != NULL);
693 kauth_cred_free(np->netc_anon);
694 np->netc_anon = NULL;
695 } else {
696 KASSERT(ne->ne_defexported.netc_anon == NULL);
697 }
698
699 mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
700 }
701
702 /*
703 * Add a new export entry (described by an export_args structure) to the
704 * given file system.
705 */
706 static int
707 export(struct netexport *nep, const struct export_args *argp)
708 {
709 struct mount *mp = nep->ne_mount;
710 int error;
711
712 if (argp->ex_flags & MNT_EXPORTED) {
713 if (argp->ex_flags & MNT_EXPUBLIC) {
714 if ((error = setpublicfs(mp, nep, argp)) != 0)
715 return error;
716 mp->mnt_flag |= MNT_EXPUBLIC;
717 }
718 if ((error = hang_addrlist(mp, nep, argp)) != 0)
719 return error;
720 mp->mnt_flag |= MNT_EXPORTED;
721 }
722 return 0;
723 }
724
725 /*
726 * Set the publicly exported filesystem (WebNFS). Currently, only
727 * one public filesystem is possible in the spec (RFC 2054 and 2055)
728 */
729 static int
730 setpublicfs(struct mount *mp, struct netexport *nep,
731 const struct export_args *argp)
732 {
733 char *cp;
734 int error;
735 struct vnode *rvp;
736 size_t fhsize;
737
738 /*
739 * mp == NULL --> invalidate the current info; the FS is
740 * no longer exported. May be called from either export
741 * or unmount, so check if it hasn't already been done.
742 */
743 if (mp == NULL) {
744 if (nfs_pub.np_valid) {
745 nfs_pub.np_valid = 0;
746 if (nfs_pub.np_handle != NULL) {
747 free(nfs_pub.np_handle, M_TEMP);
748 nfs_pub.np_handle = NULL;
749 }
750 if (nfs_pub.np_index != NULL) {
751 free(nfs_pub.np_index, M_TEMP);
752 nfs_pub.np_index = NULL;
753 }
754 }
755 return 0;
756 }
757
758 /*
759 * Only one allowed at a time.
760 */
761 if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
762 return EBUSY;
763
764 /*
765 * Get real filehandle for root of exported FS.
766 */
767 if ((error = VFS_ROOT(mp, &rvp)))
768 return error;
769
770 fhsize = 0;
771 error = vfs_composefh(rvp, NULL, &fhsize);
772 if (error != E2BIG)
773 return error;
774 nfs_pub.np_handle = malloc(fhsize, M_TEMP, M_NOWAIT);
775 if (nfs_pub.np_handle == NULL)
776 error = ENOMEM;
777 else
778 error = vfs_composefh(rvp, nfs_pub.np_handle, &fhsize);
779 if (error)
780 return error;
781
782 vput(rvp);
783
784 /*
785 * If an indexfile was specified, pull it in.
786 */
787 if (argp->ex_indexfile != NULL) {
788 nfs_pub.np_index = malloc(NFS_MAXNAMLEN + 1, M_TEMP, M_WAITOK);
789 error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
790 NFS_MAXNAMLEN, (size_t *)0);
791 if (!error) {
792 /*
793 * Check for illegal filenames.
794 */
795 for (cp = nfs_pub.np_index; *cp; cp++) {
796 if (*cp == '/') {
797 error = EINVAL;
798 break;
799 }
800 }
801 }
802 if (error) {
803 free(nfs_pub.np_index, M_TEMP);
804 return error;
805 }
806 }
807
808 nfs_pub.np_mount = mp;
809 nfs_pub.np_valid = 1;
810 return 0;
811 }
812
813 /*
814 * Look up an export entry in the exports list that matches the address
815 * stored in 'nam'. If no entry is found, the default one is used instead
816 * (if available).
817 */
818 static struct netcred *
819 netcred_lookup(struct netexport *ne, struct mbuf *nam)
820 {
821 struct netcred *np;
822 struct radix_node_head *rnh;
823 struct sockaddr *saddr;
824
825 if ((ne->ne_mount->mnt_flag & MNT_EXPORTED) == 0) {
826 return NULL;
827 }
828
829 /*
830 * Look in the export list first.
831 */
832 np = NULL;
833 if (nam != NULL) {
834 saddr = mtod(nam, struct sockaddr *);
835 rnh = ne->ne_rtable[saddr->sa_family];
836 if (rnh != NULL) {
837 np = (struct netcred *)
838 (*rnh->rnh_matchaddr)((void *)saddr,
839 rnh);
840 if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
841 np = NULL;
842 }
843 }
844 /*
845 * If no address match, use the default if it exists.
846 */
847 if (np == NULL && ne->ne_mount->mnt_flag & MNT_DEFEXPORTED)
848 np = &ne->ne_defexported;
849
850 return np;
851 }
852
853 void
854 netexport_rdlock(void)
855 {
856
857 rw_enter(&netexport_lock, RW_READER);
858 }
859
860 void
861 netexport_rdunlock(void)
862 {
863
864 rw_exit(&netexport_lock);
865 }
866
867 static void
868 netexport_wrlock(void)
869 {
870
871 rw_enter(&netexport_lock, RW_WRITER);
872 }
873
874 static void
875 netexport_wrunlock(void)
876 {
877
878 rw_exit(&netexport_lock);
879 }
880