Home | History | Annotate | Line # | Download | only in nfs
nfs_export.c revision 1.52
      1 /*	$NetBSD: nfs_export.c,v 1.52 2013/08/30 07:25:43 dholland 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 1.52 2013/08/30 07:25:43 dholland 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 	CIRCLEQ_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 CIRCLEQ_HEAD(, netexport) netexport_list =
    127     CIRCLEQ_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 has 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 (!CIRCLEQ_EMPTY(&netexport_list)) {
    211 		netexport_wrlock();
    212 		ne = CIRCLEQ_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 	/* Lookup 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 	CIRCLEQ_INSERT_HEAD(&netexport_list, ne, ne_list);
    344 }
    345 
    346 static void
    347 netexport_remove(struct netexport *ne)
    348 {
    349 
    350 	CIRCLEQ_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 	CIRCLEQ_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 	CIRCLEQ_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 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 		/* The following assumes export_args has not changed since
    449 		 * export_args30 - typedef checks sizes. */
    450 		typedef char x[sizeof args->eargs == sizeof *mel.mel_exports ? 1 : -1];
    451 
    452 		mel.mel_nexports = 1;
    453 		mel.mel_exports = (void *)&args->eargs;
    454 	}
    455 
    456 	return mountd_set_exports_list(&mel, curlwp, mp);
    457 }
    458 
    459 /*
    460  * INTERNAL FUNCTIONS
    461  */
    462 
    463 /*
    464  * Initializes NFS exports for the mountpoint given in 'mp'.
    465  * If successful, returns 0 and sets *nep to the address of the new
    466  * netexport item; otherwise returns an appropriate error code
    467  * and *nep remains unmodified.
    468  */
    469 static int
    470 init_exports(struct mount *mp, struct netexport **nep)
    471 {
    472 	int error;
    473 	struct export_args ea;
    474 	struct netexport *ne;
    475 
    476 	KASSERT(mp != NULL);
    477 
    478 	/* Ensure that we do not already have this mount point. */
    479 	KASSERT(netexport_lookup(mp) == NULL);
    480 
    481 	ne = kmem_zalloc(sizeof(*ne), KM_SLEEP);
    482 	ne->ne_mount = mp;
    483 
    484 	/* Set the default export entry.  Handled internally by export upon
    485 	 * first call. */
    486 	memset(&ea, 0, sizeof(ea));
    487 	ea.ex_root = -2;
    488 	if (mp->mnt_flag & MNT_RDONLY)
    489 		ea.ex_flags |= MNT_EXRDONLY;
    490 	error = export(ne, &ea);
    491 	if (error != 0) {
    492 		kmem_free(ne, sizeof(*ne));
    493 	} else {
    494 		netexport_insert(ne);
    495 		*nep = ne;
    496 	}
    497 
    498 	return error;
    499 }
    500 
    501 /*
    502  * Build hash lists of net addresses and hang them off the mount point.
    503  * Called by export() to set up a new entry in the lists of export
    504  * addresses.
    505  */
    506 static int
    507 hang_addrlist(struct mount *mp, struct netexport *nep,
    508     const struct export_args *argp)
    509 {
    510 	int error, i;
    511 	struct netcred *np, *enp;
    512 	struct radix_node_head *rnh;
    513 	struct sockaddr *saddr, *smask;
    514 	struct domain *dom;
    515 
    516 	smask = NULL;
    517 
    518 	if (argp->ex_addrlen == 0) {
    519 		if (mp->mnt_flag & MNT_DEFEXPORTED)
    520 			return EPERM;
    521 		np = &nep->ne_defexported;
    522 		KASSERT(np->netc_anon == NULL);
    523 		np->netc_anon = kauth_cred_alloc();
    524 		np->netc_exflags = argp->ex_flags;
    525 		kauth_uucred_to_cred(np->netc_anon, &argp->ex_anon);
    526 		mp->mnt_flag |= MNT_DEFEXPORTED;
    527 		return 0;
    528 	}
    529 
    530 	if (argp->ex_addrlen > MLEN || argp->ex_masklen > MLEN)
    531 		return EINVAL;
    532 
    533 	i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
    534 	np = malloc(i, M_NETADDR, M_WAITOK | M_ZERO);
    535 	np->netc_anon = kauth_cred_alloc();
    536 	saddr = (struct sockaddr *)(np + 1);
    537 	error = copyin(argp->ex_addr, saddr, argp->ex_addrlen);
    538 	if (error)
    539 		goto out;
    540 	if (saddr->sa_len > argp->ex_addrlen)
    541 		saddr->sa_len = argp->ex_addrlen;
    542 	if (sacheck(saddr) == -1)
    543 		return EINVAL;
    544 	if (argp->ex_masklen) {
    545 		smask = (struct sockaddr *)((char *)saddr + argp->ex_addrlen);
    546 		error = copyin(argp->ex_mask, smask, argp->ex_masklen);
    547 		if (error)
    548 			goto out;
    549 		if (smask->sa_len > argp->ex_masklen)
    550 			smask->sa_len = argp->ex_masklen;
    551 		if (smask->sa_family != saddr->sa_family)
    552 			return EINVAL;
    553 		if (sacheck(smask) == -1)
    554 			return EINVAL;
    555 	}
    556 	i = saddr->sa_family;
    557 	if ((rnh = nep->ne_rtable[i]) == 0) {
    558 		/*
    559 		 * Seems silly to initialize every AF when most are not
    560 		 * used, do so on demand here
    561 		 */
    562 		DOMAIN_FOREACH(dom) {
    563 			if (dom->dom_family == i && dom->dom_rtattach) {
    564 				rn_inithead((void **)&nep->ne_rtable[i],
    565 					dom->dom_rtoffset);
    566 				break;
    567 			}
    568 		}
    569 		if ((rnh = nep->ne_rtable[i]) == 0) {
    570 			error = ENOBUFS;
    571 			goto out;
    572 		}
    573 	}
    574 
    575 	enp = (struct netcred *)(*rnh->rnh_addaddr)(saddr, smask, rnh,
    576 	    np->netc_rnodes);
    577 	if (enp != np) {
    578 		if (enp == NULL) {
    579 			enp = (struct netcred *)(*rnh->rnh_lookup)(saddr,
    580 			    smask, rnh);
    581 			if (enp == NULL) {
    582 				error = EPERM;
    583 				goto out;
    584 			}
    585 		} else
    586 			enp->netc_refcnt++;
    587 
    588 		goto check;
    589 	} else
    590 		enp->netc_refcnt = 1;
    591 
    592 	np->netc_exflags = argp->ex_flags;
    593 	kauth_uucred_to_cred(np->netc_anon, &argp->ex_anon);
    594 	return 0;
    595 check:
    596 	if (enp->netc_exflags != argp->ex_flags ||
    597 	    kauth_cred_uucmp(enp->netc_anon, &argp->ex_anon) != 0)
    598 		error = EPERM;
    599 	else
    600 		error = 0;
    601 out:
    602 	KASSERT(np->netc_anon != NULL);
    603 	kauth_cred_free(np->netc_anon);
    604 	free(np, M_NETADDR);
    605 	return error;
    606 }
    607 
    608 /*
    609  * Ensure that the address stored in 'sa' is valid.
    610  * Returns zero on success, otherwise -1.
    611  */
    612 static int
    613 sacheck(struct sockaddr *sa)
    614 {
    615 
    616 	switch (sa->sa_family) {
    617 	case AF_INET: {
    618 		struct sockaddr_in *sin = (struct sockaddr_in *)sa;
    619 		char *p = (char *)sin->sin_zero;
    620 		size_t i;
    621 
    622 		if (sin->sin_len != sizeof(*sin))
    623 			return -1;
    624 		if (sin->sin_port != 0)
    625 			return -1;
    626 		for (i = 0; i < sizeof(sin->sin_zero); i++)
    627 			if (*p++ != '\0')
    628 				return -1;
    629 		return 0;
    630 	}
    631 	case AF_INET6: {
    632 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
    633 
    634 		if (sin6->sin6_len != sizeof(*sin6))
    635 			return -1;
    636 		if (sin6->sin6_port != 0)
    637 			return -1;
    638 		return 0;
    639 	}
    640 	default:
    641 		return -1;
    642 	}
    643 }
    644 
    645 /*
    646  * Free the netcred object pointed to by the 'rn' radix node.
    647  * 'w' holds a pointer to the radix tree head.
    648  */
    649 static int
    650 free_netcred(struct radix_node *rn, void *w)
    651 {
    652 	struct radix_node_head *rnh = (struct radix_node_head *)w;
    653 	struct netcred *np = (struct netcred *)(void *)rn;
    654 
    655 	(*rnh->rnh_deladdr)(rn->rn_key, rn->rn_mask, rnh);
    656 	if (--(np->netc_refcnt) <= 0) {
    657 		KASSERT(np->netc_anon != NULL);
    658 		kauth_cred_free(np->netc_anon);
    659 		free(np, M_NETADDR);
    660 	}
    661 	return 0;
    662 }
    663 
    664 /*
    665  * Clears the exports list for a given file system.
    666  */
    667 static void
    668 netexport_clear(struct netexport *ne)
    669 {
    670 	struct radix_node_head *rnh;
    671 	struct mount *mp = ne->ne_mount;
    672 	int i;
    673 
    674 	if (mp->mnt_flag & MNT_EXPUBLIC) {
    675 		setpublicfs(NULL, NULL, NULL);
    676 		mp->mnt_flag &= ~MNT_EXPUBLIC;
    677 	}
    678 
    679 	for (i = 0; i <= AF_MAX; i++) {
    680 		if ((rnh = ne->ne_rtable[i]) != NULL) {
    681 			rn_walktree(rnh, free_netcred, rnh);
    682 			free(rnh, M_RTABLE);
    683 			ne->ne_rtable[i] = NULL;
    684 		}
    685 	}
    686 
    687 	if ((mp->mnt_flag & MNT_DEFEXPORTED) != 0) {
    688 		struct netcred *np = &ne->ne_defexported;
    689 
    690 		KASSERT(np->netc_anon != NULL);
    691 		kauth_cred_free(np->netc_anon);
    692 		np->netc_anon = NULL;
    693 	} else {
    694 		KASSERT(ne->ne_defexported.netc_anon == NULL);
    695 	}
    696 
    697 	mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
    698 }
    699 
    700 /*
    701  * Add a new export entry (described by an export_args structure) to the
    702  * given file system.
    703  */
    704 static int
    705 export(struct netexport *nep, const struct export_args *argp)
    706 {
    707 	struct mount *mp = nep->ne_mount;
    708 	int error;
    709 
    710 	if (argp->ex_flags & MNT_EXPORTED) {
    711 		if (argp->ex_flags & MNT_EXPUBLIC) {
    712 			if ((error = setpublicfs(mp, nep, argp)) != 0)
    713 				return error;
    714 			mp->mnt_flag |= MNT_EXPUBLIC;
    715 		}
    716 		if ((error = hang_addrlist(mp, nep, argp)) != 0)
    717 			return error;
    718 		mp->mnt_flag |= MNT_EXPORTED;
    719 	}
    720 	return 0;
    721 }
    722 
    723 /*
    724  * Set the publicly exported filesystem (WebNFS).  Currently, only
    725  * one public filesystem is possible in the spec (RFC 2054 and 2055)
    726  */
    727 static int
    728 setpublicfs(struct mount *mp, struct netexport *nep,
    729     const struct export_args *argp)
    730 {
    731 	char *cp;
    732 	int error;
    733 	struct vnode *rvp;
    734 	size_t fhsize;
    735 
    736 	/*
    737 	 * mp == NULL -> invalidate the current info, the FS is
    738 	 * no longer exported. May be called from either export
    739 	 * or unmount, so check if it hasn't already been done.
    740 	 */
    741 	if (mp == NULL) {
    742 		if (nfs_pub.np_valid) {
    743 			nfs_pub.np_valid = 0;
    744 			if (nfs_pub.np_handle != NULL) {
    745 				free(nfs_pub.np_handle, M_TEMP);
    746 				nfs_pub.np_handle = NULL;
    747 			}
    748 			if (nfs_pub.np_index != NULL) {
    749 				free(nfs_pub.np_index, M_TEMP);
    750 				nfs_pub.np_index = NULL;
    751 			}
    752 		}
    753 		return 0;
    754 	}
    755 
    756 	/*
    757 	 * Only one allowed at a time.
    758 	 */
    759 	if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
    760 		return EBUSY;
    761 
    762 	/*
    763 	 * Get real filehandle for root of exported FS.
    764 	 */
    765 	if ((error = VFS_ROOT(mp, &rvp)))
    766 		return error;
    767 
    768 	fhsize = 0;
    769 	error = vfs_composefh(rvp, NULL, &fhsize);
    770 	if (error != E2BIG)
    771 		return error;
    772 	nfs_pub.np_handle = malloc(fhsize, M_TEMP, M_NOWAIT);
    773 	if (nfs_pub.np_handle == NULL)
    774 		error = ENOMEM;
    775 	else
    776 		error = vfs_composefh(rvp, nfs_pub.np_handle, &fhsize);
    777 	if (error)
    778 		return error;
    779 
    780 	vput(rvp);
    781 
    782 	/*
    783 	 * If an indexfile was specified, pull it in.
    784 	 */
    785 	if (argp->ex_indexfile != NULL) {
    786 		nfs_pub.np_index = malloc(NFS_MAXNAMLEN + 1, M_TEMP, M_WAITOK);
    787 		error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
    788 		    NFS_MAXNAMLEN, (size_t *)0);
    789 		if (!error) {
    790 			/*
    791 			 * Check for illegal filenames.
    792 			 */
    793 			for (cp = nfs_pub.np_index; *cp; cp++) {
    794 				if (*cp == '/') {
    795 					error = EINVAL;
    796 					break;
    797 				}
    798 			}
    799 		}
    800 		if (error) {
    801 			free(nfs_pub.np_index, M_TEMP);
    802 			return error;
    803 		}
    804 	}
    805 
    806 	nfs_pub.np_mount = mp;
    807 	nfs_pub.np_valid = 1;
    808 	return 0;
    809 }
    810 
    811 /*
    812  * Lookup an export entry in the exports list that matches the address
    813  * stored in 'nam'.  If no entry is found, the default one is used instead
    814  * (if available).
    815  */
    816 static struct netcred *
    817 netcred_lookup(struct netexport *ne, struct mbuf *nam)
    818 {
    819 	struct netcred *np;
    820 	struct radix_node_head *rnh;
    821 	struct sockaddr *saddr;
    822 
    823 	if ((ne->ne_mount->mnt_flag & MNT_EXPORTED) == 0) {
    824 		return NULL;
    825 	}
    826 
    827 	/*
    828 	 * Lookup in the export list first.
    829 	 */
    830 	np = NULL;
    831 	if (nam != NULL) {
    832 		saddr = mtod(nam, struct sockaddr *);
    833 		rnh = ne->ne_rtable[saddr->sa_family];
    834 		if (rnh != NULL) {
    835 			np = (struct netcred *)
    836 				(*rnh->rnh_matchaddr)((void *)saddr,
    837 						      rnh);
    838 			if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
    839 				np = NULL;
    840 		}
    841 	}
    842 	/*
    843 	 * If no address match, use the default if it exists.
    844 	 */
    845 	if (np == NULL && ne->ne_mount->mnt_flag & MNT_DEFEXPORTED)
    846 		np = &ne->ne_defexported;
    847 
    848 	return np;
    849 }
    850 
    851 void
    852 netexport_rdlock(void)
    853 {
    854 
    855 	rw_enter(&netexport_lock, RW_READER);
    856 }
    857 
    858 void
    859 netexport_rdunlock(void)
    860 {
    861 
    862 	rw_exit(&netexport_lock);
    863 }
    864 
    865 static void
    866 netexport_wrlock(void)
    867 {
    868 
    869 	rw_enter(&netexport_lock, RW_WRITER);
    870 }
    871 
    872 static void
    873 netexport_wrunlock(void)
    874 {
    875 
    876 	rw_exit(&netexport_lock);
    877 }
    878