NetBSD-5.0.2/sys/nfs/nfs_export.c
/* $NetBSD: nfs_export.c,v 1.38 2008/05/10 02:26:10 rumble Exp $ */
/*-
* Copyright (c) 1997, 1998, 2004, 2005, 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center.
* This code is derived from software contributed to The NetBSD Foundation
* by Charles M. Hannum.
* This code is derived from software contributed to The NetBSD Foundation
* by Julio M. Merino Vidal.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)vfs_subr.c 8.13 (Berkeley) 4/18/94
*/
/*
* VFS exports list management.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: nfs_export.c,v 1.38 2008/05/10 02:26:10 rumble Exp $");
#include "opt_compat_netbsd.h"
#include "opt_inet.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/queue.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/namei.h>
#include <sys/errno.h>
#include <sys/malloc.h>
#include <sys/domain.h>
#include <sys/mbuf.h>
#include <sys/dirent.h>
#include <sys/socket.h> /* XXX for AF_MAX */
#include <sys/kauth.h>
#include <net/radix.h>
#include <netinet/in.h>
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nfs_var.h>
/*
* Network address lookup element.
*/
struct netcred {
struct radix_node netc_rnodes[2];
int netc_refcnt;
int netc_exflags;
kauth_cred_t netc_anon;
};
/*
* Network export information.
*/
struct netexport {
CIRCLEQ_ENTRY(netexport) ne_list;
struct mount *ne_mount;
struct netcred ne_defexported; /* Default export */
struct radix_node_head *ne_rtable[AF_MAX+1]; /* Individual exports */
};
CIRCLEQ_HEAD(, netexport) netexport_list =
CIRCLEQ_HEAD_INITIALIZER(netexport_list);
/* Malloc type used by the mount<->netexport map. */
MALLOC_DEFINE(M_NFS_EXPORT, "nfs_export", "NFS export data");
/* Publicly exported file system. */
struct nfs_public nfs_pub;
/*
* Local prototypes.
*/
static int init_exports(struct mount *, struct netexport **);
static int hang_addrlist(struct mount *, struct netexport *,
const struct export_args *);
static int sacheck(struct sockaddr *);
static int free_netcred(struct radix_node *, void *);
static int export(struct netexport *, const struct export_args *);
static int setpublicfs(struct mount *, struct netexport *,
const struct export_args *);
static struct netcred *netcred_lookup(struct netexport *, struct mbuf *);
static struct netexport *netexport_lookup(const struct mount *);
static struct netexport *netexport_lookup_byfsid(const fsid_t *);
static void netexport_clear(struct netexport *);
static void netexport_insert(struct netexport *);
static void netexport_remove(struct netexport *);
static void netexport_wrlock(void);
static void netexport_wrunlock(void);
/*
* PUBLIC INTERFACE
*/
/*
* Declare and initialize the file system export hooks.
*/
static void nfs_export_unmount(struct mount *);
struct vfs_hooks nfs_export_hooks = {
nfs_export_unmount,
{ NULL, NULL }
};
/*
* VFS unmount hook for NFS exports.
*
* Releases NFS exports list resources if the given mount point has some.
* As allocation happens lazily, it may be that it doesn't has this
* information, although it theorically should.
*/
static void
nfs_export_unmount(struct mount *mp)
{
struct netexport *ne;
KASSERT(mp != NULL);
netexport_wrlock();
ne = netexport_lookup(mp);
if (ne == NULL) {
netexport_wrunlock();
return;
}
netexport_clear(ne);
netexport_remove(ne);
netexport_wrunlock();
free(ne, M_NFS_EXPORT);
}
/*
* Atomically set the NFS exports list of the given file system, replacing
* it with a new list of entries.
*
* Returns zero on success or an appropriate error code otherwise.
*
* Helper function for the nfssvc(2) system call (NFSSVC_SETEXPORTSLIST
* command).
*/
int
mountd_set_exports_list(const struct mountd_exports_list *mel, struct lwp *l)
{
int error;
#ifdef notyet
/* XXX: See below to see the reason why this is disabled. */
size_t i;
#endif
struct mount *mp;
struct netexport *ne;
struct nameidata nd;
struct vnode *vp;
struct fid *fid;
size_t fid_size;
if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_NFS,
KAUTH_REQ_NETWORK_NFS_EXPORT, NULL, NULL, NULL) != 0)
return EPERM;
/* Lookup the file system path. */
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE, mel->mel_path);
error = namei(&nd);
if (error != 0)
return error;
vp = nd.ni_vp;
mp = vp->v_mount;
fid_size = 0;
if ((error = VFS_VPTOFH(vp, NULL, &fid_size)) == E2BIG) {
fid = malloc(fid_size, M_TEMP, M_NOWAIT);
if (fid != NULL) {
error = VFS_VPTOFH(vp, fid, &fid_size);
free(fid, M_TEMP);
}
}
if (error != 0) {
vput(vp);
return EOPNOTSUPP;
}
/* Mark the file system busy. */
error = vfs_busy(mp, NULL);
vput(vp);
if (error != 0)
return error;
netexport_wrlock();
ne = netexport_lookup(mp);
if (ne == NULL) {
error = init_exports(mp, &ne);
if (error != 0) {
goto out;
}
}
KASSERT(ne != NULL);
KASSERT(ne->ne_mount == mp);
/*
* XXX: The part marked as 'notyet' works fine from the kernel's
* point of view, in the sense that it is able to atomically update
* the complete exports list for a file system. However, supporting
* this in mountd(8) requires a lot of work; so, for now, keep the
* old behavior of updating a single entry per call.
*
* When mountd(8) is fixed, just remove the second branch of this
* preprocessor conditional and enable the first one.
*/
#ifdef notyet
netexport_clear(ne);
for (i = 0; error == 0 && i < mel->mel_nexports; i++)
error = export(ne, &mel->mel_exports[i]);
#else
if (mel->mel_nexports == 0)
netexport_clear(ne);
else if (mel->mel_nexports == 1)
error = export(ne, &mel->mel_exports[0]);
else {
printf("mountd_set_exports_list: Cannot set more than one "
"entry at once (unimplemented)\n");
error = EOPNOTSUPP;
}
#endif
out:
netexport_wrunlock();
vfs_unbusy(mp, false, NULL);
return error;
}
static void
netexport_insert(struct netexport *ne)
{
CIRCLEQ_INSERT_HEAD(&netexport_list, ne, ne_list);
}
static void
netexport_remove(struct netexport *ne)
{
CIRCLEQ_REMOVE(&netexport_list, ne, ne_list);
}
static struct netexport *
netexport_lookup(const struct mount *mp)
{
struct netexport *ne;
CIRCLEQ_FOREACH(ne, &netexport_list, ne_list) {
if (ne->ne_mount == mp) {
goto done;
}
}
ne = NULL;
done:
return ne;
}
static struct netexport *
netexport_lookup_byfsid(const fsid_t *fsid)
{
struct netexport *ne;
CIRCLEQ_FOREACH(ne, &netexport_list, ne_list) {
const struct mount *mp = ne->ne_mount;
if (mp->mnt_stat.f_fsidx.__fsid_val[0] == fsid->__fsid_val[0] &&
mp->mnt_stat.f_fsidx.__fsid_val[1] == fsid->__fsid_val[1]) {
goto done;
}
}
ne = NULL;
done:
return ne;
}
/*
* Check if the file system specified by the 'mp' mount structure is
* exported to a client with 'anon' anonymous credentials. The 'mb'
* argument is an mbuf containing the network address of the client.
* The return parameters for the export flags for the client are returned
* in the address specified by 'wh'.
*
* This function is used exclusively by the NFS server. It is generally
* invoked before VFS_FHTOVP to validate that client has access to the
* file system.
*/
int
netexport_check(const fsid_t *fsid, struct mbuf *mb, struct mount **mpp,
int *wh, kauth_cred_t *anon)
{
struct netexport *ne;
struct netcred *np;
ne = netexport_lookup_byfsid(fsid);
if (ne == NULL) {
return EACCES;
}
np = netcred_lookup(ne, mb);
if (np == NULL) {
return EACCES;
}
*mpp = ne->ne_mount;
*wh = np->netc_exflags;
*anon = np->netc_anon;
return 0;
}
#ifdef COMPAT_30
/*
* Handles legacy export requests. In this case, the export information
* is hardcoded in a specific place of the mount arguments structure (given
* in data); the request for an update is given through the fspec field
* (also in a known location), which must be a null pointer.
*
* Returns EJUSTRETURN if the given command was not a export request.
* Otherwise, returns 0 on success or an appropriate error code otherwise.
*/
int
nfs_update_exports_30(struct mount *mp, const char *path,
struct mnt_export_args30 *args, struct lwp *l)
{
struct mountd_exports_list mel;
mel.mel_path = path;
if (args->fspec != NULL)
return EJUSTRETURN;
if (args->eargs.ex_flags & 0x00020000) {
/* Request to delete exports. The mask above holds the
* value that used to be in MNT_DELEXPORT. */
mel.mel_nexports = 0;
} else {
/* The following assumes export_args has not changed since
* export_args30 - typedef checks sizes. */
typedef char x[sizeof args->eargs == sizeof *mel.mel_exports ? 1 : -1];
mel.mel_nexports = 1;
mel.mel_exports = (void *)&args->eargs;
}
return mountd_set_exports_list(&mel, l);
}
#endif
/*
* INTERNAL FUNCTIONS
*/
/*
* Initializes NFS exports for the file system given in 'mp' if it supports
* file handles; this is determined by checking whether mp's vfs_vptofh and
* vfs_fhtovp operations are NULL or not.
*
* If successful, returns 0 and sets *mnpp to the address of the new
* mount_netexport_pair item; otherwise returns an appropriate error code
* and *mnpp remains unmodified.
*/
static int
init_exports(struct mount *mp, struct netexport **nep)
{
int error;
struct export_args ea;
struct netexport *ne;
KASSERT(mp != NULL);
/* Ensure that we do not already have this mount point. */
KASSERT(netexport_lookup(mp) == NULL);
ne = malloc(sizeof(*ne), M_NFS_EXPORT, M_WAITOK | M_ZERO);
ne->ne_mount = mp;
/* Set the default export entry. Handled internally by export upon
* first call. */
memset(&ea, 0, sizeof(ea));
ea.ex_root = -2;
if (mp->mnt_flag & MNT_RDONLY)
ea.ex_flags |= MNT_EXRDONLY;
error = export(ne, &ea);
if (error != 0) {
free(ne, M_NFS_EXPORT);
} else {
netexport_insert(ne);
*nep = ne;
}
return error;
}
/*
* Build hash lists of net addresses and hang them off the mount point.
* Called by export() to set up a new entry in the lists of export
* addresses.
*/
static int
hang_addrlist(struct mount *mp, struct netexport *nep,
const struct export_args *argp)
{
int error, i;
struct netcred *np, *enp;
struct radix_node_head *rnh;
struct sockaddr *saddr, *smask;
struct domain *dom;
smask = NULL;
if (argp->ex_addrlen == 0) {
if (mp->mnt_flag & MNT_DEFEXPORTED)
return EPERM;
np = &nep->ne_defexported;
KASSERT(np->netc_anon == NULL);
np->netc_anon = kauth_cred_alloc();
np->netc_exflags = argp->ex_flags;
kauth_uucred_to_cred(np->netc_anon, &argp->ex_anon);
mp->mnt_flag |= MNT_DEFEXPORTED;
return 0;
}
if (argp->ex_addrlen > MLEN || argp->ex_masklen > MLEN)
return EINVAL;
i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
np = malloc(i, M_NETADDR, M_WAITOK | M_ZERO);
np->netc_anon = kauth_cred_alloc();
saddr = (struct sockaddr *)(np + 1);
error = copyin(argp->ex_addr, saddr, argp->ex_addrlen);
if (error)
goto out;
if (saddr->sa_len > argp->ex_addrlen)
saddr->sa_len = argp->ex_addrlen;
if (sacheck(saddr) == -1)
return EINVAL;
if (argp->ex_masklen) {
smask = (struct sockaddr *)((char *)saddr + argp->ex_addrlen);
error = copyin(argp->ex_mask, smask, argp->ex_masklen);
if (error)
goto out;
if (smask->sa_len > argp->ex_masklen)
smask->sa_len = argp->ex_masklen;
if (smask->sa_family != saddr->sa_family)
return EINVAL;
if (sacheck(smask) == -1)
return EINVAL;
}
i = saddr->sa_family;
if ((rnh = nep->ne_rtable[i]) == 0) {
/*
* Seems silly to initialize every AF when most are not
* used, do so on demand here
*/
DOMAIN_FOREACH(dom) {
if (dom->dom_family == i && dom->dom_rtattach) {
dom->dom_rtattach((void **)&nep->ne_rtable[i],
dom->dom_rtoffset);
break;
}
}
if ((rnh = nep->ne_rtable[i]) == 0) {
error = ENOBUFS;
goto out;
}
}
enp = (struct netcred *)(*rnh->rnh_addaddr)(saddr, smask, rnh,
np->netc_rnodes);
if (enp != np) {
if (enp == NULL) {
enp = (struct netcred *)(*rnh->rnh_lookup)(saddr,
smask, rnh);
if (enp == NULL) {
error = EPERM;
goto out;
}
} else
enp->netc_refcnt++;
goto check;
} else
enp->netc_refcnt = 1;
np->netc_exflags = argp->ex_flags;
kauth_uucred_to_cred(np->netc_anon, &argp->ex_anon);
return 0;
check:
if (enp->netc_exflags != argp->ex_flags ||
kauth_cred_uucmp(enp->netc_anon, &argp->ex_anon) != 0)
error = EPERM;
else
error = 0;
out:
KASSERT(np->netc_anon != NULL);
kauth_cred_free(np->netc_anon);
free(np, M_NETADDR);
return error;
}
/*
* Ensure that the address stored in 'sa' is valid.
* Returns zero on success, otherwise -1.
*/
static int
sacheck(struct sockaddr *sa)
{
switch (sa->sa_family) {
#ifdef INET
case AF_INET: {
struct sockaddr_in *sin = (struct sockaddr_in *)sa;
char *p = (char *)sin->sin_zero;
size_t i;
if (sin->sin_len != sizeof(*sin))
return -1;
if (sin->sin_port != 0)
return -1;
for (i = 0; i < sizeof(sin->sin_zero); i++)
if (*p++ != '\0')
return -1;
return 0;
}
#endif
#ifdef INET6
case AF_INET6: {
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
if (sin6->sin6_len != sizeof(*sin6))
return -1;
if (sin6->sin6_port != 0)
return -1;
return 0;
}
#endif
default:
return -1;
}
}
/*
* Free the netcred object pointed to by the 'rn' radix node.
* 'w' holds a pointer to the radix tree head.
*/
static int
free_netcred(struct radix_node *rn, void *w)
{
struct radix_node_head *rnh = (struct radix_node_head *)w;
struct netcred *np = (struct netcred *)(void *)rn;
(*rnh->rnh_deladdr)(rn->rn_key, rn->rn_mask, rnh);
if (--(np->netc_refcnt) <= 0) {
KASSERT(np->netc_anon != NULL);
kauth_cred_free(np->netc_anon);
free(np, M_NETADDR);
}
return 0;
}
/*
* Clears the exports list for a given file system.
*/
static void
netexport_clear(struct netexport *ne)
{
struct radix_node_head *rnh;
struct mount *mp = ne->ne_mount;
int i;
if (mp->mnt_flag & MNT_EXPUBLIC) {
setpublicfs(NULL, NULL, NULL);
mp->mnt_flag &= ~MNT_EXPUBLIC;
}
for (i = 0; i <= AF_MAX; i++) {
if ((rnh = ne->ne_rtable[i]) != NULL) {
rn_walktree(rnh, free_netcred, rnh);
free(rnh, M_RTABLE);
ne->ne_rtable[i] = NULL;
}
}
if ((mp->mnt_flag & MNT_DEFEXPORTED) != 0) {
struct netcred *np = &ne->ne_defexported;
KASSERT(np->netc_anon != NULL);
kauth_cred_free(np->netc_anon);
np->netc_anon = NULL;
} else {
KASSERT(ne->ne_defexported.netc_anon == NULL);
}
mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
}
/*
* Add a new export entry (described by an export_args structure) to the
* given file system.
*/
static int
export(struct netexport *nep, const struct export_args *argp)
{
struct mount *mp = nep->ne_mount;
int error;
if (argp->ex_flags & MNT_EXPORTED) {
if (argp->ex_flags & MNT_EXPUBLIC) {
if ((error = setpublicfs(mp, nep, argp)) != 0)
return error;
mp->mnt_flag |= MNT_EXPUBLIC;
}
if ((error = hang_addrlist(mp, nep, argp)) != 0)
return error;
mp->mnt_flag |= MNT_EXPORTED;
}
return 0;
}
/*
* Set the publicly exported filesystem (WebNFS). Currently, only
* one public filesystem is possible in the spec (RFC 2054 and 2055)
*/
static int
setpublicfs(struct mount *mp, struct netexport *nep,
const struct export_args *argp)
{
char *cp;
int error;
struct vnode *rvp;
size_t fhsize;
/*
* mp == NULL -> invalidate the current info, the FS is
* no longer exported. May be called from either export
* or unmount, so check if it hasn't already been done.
*/
if (mp == NULL) {
if (nfs_pub.np_valid) {
nfs_pub.np_valid = 0;
if (nfs_pub.np_handle != NULL) {
free(nfs_pub.np_handle, M_TEMP);
nfs_pub.np_handle = NULL;
}
if (nfs_pub.np_index != NULL) {
FREE(nfs_pub.np_index, M_TEMP);
nfs_pub.np_index = NULL;
}
}
return 0;
}
/*
* Only one allowed at a time.
*/
if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
return EBUSY;
/*
* Get real filehandle for root of exported FS.
*/
if ((error = VFS_ROOT(mp, &rvp)))
return error;
fhsize = 0;
error = vfs_composefh(rvp, NULL, &fhsize);
if (error != E2BIG)
return error;
nfs_pub.np_handle = malloc(fhsize, M_TEMP, M_NOWAIT);
if (nfs_pub.np_handle == NULL)
error = ENOMEM;
else
error = vfs_composefh(rvp, nfs_pub.np_handle, &fhsize);
if (error)
return error;
vput(rvp);
/*
* If an indexfile was specified, pull it in.
*/
if (argp->ex_indexfile != NULL) {
MALLOC(nfs_pub.np_index, char *, MAXNAMLEN + 1, M_TEMP,
M_WAITOK);
error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
MAXNAMLEN, (size_t *)0);
if (!error) {
/*
* Check for illegal filenames.
*/
for (cp = nfs_pub.np_index; *cp; cp++) {
if (*cp == '/') {
error = EINVAL;
break;
}
}
}
if (error) {
FREE(nfs_pub.np_index, M_TEMP);
return error;
}
}
nfs_pub.np_mount = mp;
nfs_pub.np_valid = 1;
return 0;
}
/*
* Lookup an export entry in the exports list that matches the address
* stored in 'nam'. If no entry is found, the default one is used instead
* (if available).
*/
static struct netcred *
netcred_lookup(struct netexport *ne, struct mbuf *nam)
{
struct netcred *np;
struct radix_node_head *rnh;
struct sockaddr *saddr;
if ((ne->ne_mount->mnt_flag & MNT_EXPORTED) == 0) {
return NULL;
}
/*
* Lookup in the export list first.
*/
np = NULL;
if (nam != NULL) {
saddr = mtod(nam, struct sockaddr *);
rnh = ne->ne_rtable[saddr->sa_family];
if (rnh != NULL) {
np = (struct netcred *)
(*rnh->rnh_matchaddr)((void *)saddr,
rnh);
if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
np = NULL;
}
}
/*
* If no address match, use the default if it exists.
*/
if (np == NULL && ne->ne_mount->mnt_flag & MNT_DEFEXPORTED)
np = &ne->ne_defexported;
return np;
}
krwlock_t netexport_lock;
void
netexport_rdlock(void)
{
rw_enter(&netexport_lock, RW_READER);
}
void
netexport_rdunlock(void)
{
rw_exit(&netexport_lock);
}
static void
netexport_wrlock(void)
{
rw_enter(&netexport_lock, RW_WRITER);
}
static void
netexport_wrunlock(void)
{
rw_exit(&netexport_lock);
}