FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_export.c
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: releng/6.3/sys/kern/vfs_export.c 173886 2007-11-24 19:45:58Z cvs2svn $");
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/refcount.h>
50 #include <sys/socket.h>
51 #include <sys/systm.h>
52 #include <sys/vnode.h>
53
54 #include <net/radix.h>
55
56 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
57
58 static void vfs_free_addrlist(struct netexport *nep);
59 static int vfs_free_netcred(struct radix_node *rn, void *w);
60 static int vfs_hang_addrlist(struct mount *mp, struct netexport *nep,
61 struct export_args *argp);
62 static struct netcred *vfs_export_lookup(struct mount *, struct sockaddr *);
63
64 /*
65 * Network address lookup element
66 */
67 struct netcred {
68 struct radix_node netc_rnodes[2];
69 int netc_exflags;
70 struct ucred netc_anon;
71 };
72
73 /*
74 * Network export information
75 */
76 struct netexport {
77 struct netcred ne_defexported; /* Default export */
78 struct radix_node_head *ne_rtable[AF_MAX+1]; /* Individual exports */
79 };
80
81 /*
82 * Build hash lists of net addresses and hang them off the mount point.
83 * Called by ufs_mount() to set up the lists of export addresses.
84 */
85 static int
86 vfs_hang_addrlist(mp, nep, argp)
87 struct mount *mp;
88 struct netexport *nep;
89 struct export_args *argp;
90 {
91 register struct netcred *np;
92 register struct radix_node_head *rnh;
93 register int i;
94 struct radix_node *rn;
95 struct sockaddr *saddr, *smask = 0;
96 struct domain *dom;
97 int error;
98
99 /*
100 * XXX: This routine converts from a `struct xucred'
101 * (argp->ex_anon) to a `struct ucred' (np->netc_anon). This
102 * operation is questionable; for example, what should be done
103 * with fields like cr_uidinfo and cr_prison? Currently, this
104 * routine does not touch them (leaves them as NULL).
105 */
106 if (argp->ex_anon.cr_version != XUCRED_VERSION)
107 return (EINVAL);
108
109 if (argp->ex_addrlen == 0) {
110 if (mp->mnt_flag & MNT_DEFEXPORTED)
111 return (EPERM);
112 np = &nep->ne_defexported;
113 np->netc_exflags = argp->ex_flags;
114 bzero(&np->netc_anon, sizeof(np->netc_anon));
115 np->netc_anon.cr_uid = argp->ex_anon.cr_uid;
116 np->netc_anon.cr_ngroups = argp->ex_anon.cr_ngroups;
117 bcopy(argp->ex_anon.cr_groups, np->netc_anon.cr_groups,
118 sizeof(np->netc_anon.cr_groups));
119 refcount_init(&np->netc_anon.cr_ref, 1);
120 MNT_ILOCK(mp);
121 mp->mnt_flag |= MNT_DEFEXPORTED;
122 MNT_IUNLOCK(mp);
123 return (0);
124 }
125
126 #if MSIZE <= 256
127 if (argp->ex_addrlen > MLEN)
128 return (EINVAL);
129 #endif
130
131 i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
132 np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK | M_ZERO);
133 saddr = (struct sockaddr *) (np + 1);
134 if ((error = copyin(argp->ex_addr, saddr, argp->ex_addrlen)))
135 goto out;
136 if (saddr->sa_family > AF_MAX) {
137 error = EINVAL;
138 goto out;
139 }
140 if (saddr->sa_len > argp->ex_addrlen)
141 saddr->sa_len = argp->ex_addrlen;
142 if (argp->ex_masklen) {
143 smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen);
144 error = copyin(argp->ex_mask, smask, argp->ex_masklen);
145 if (error)
146 goto out;
147 if (smask->sa_len > argp->ex_masklen)
148 smask->sa_len = argp->ex_masklen;
149 }
150 i = saddr->sa_family;
151 if ((rnh = nep->ne_rtable[i]) == NULL) {
152 /*
153 * Seems silly to initialize every AF when most are not used,
154 * do so on demand here
155 */
156 for (dom = domains; dom; dom = dom->dom_next)
157 if (dom->dom_family == i && dom->dom_rtattach) {
158 dom->dom_rtattach((void **) &nep->ne_rtable[i],
159 dom->dom_rtoffset);
160 break;
161 }
162 if ((rnh = nep->ne_rtable[i]) == NULL) {
163 error = ENOBUFS;
164 goto out;
165 }
166 }
167 RADIX_NODE_HEAD_LOCK(rnh);
168 rn = (*rnh->rnh_addaddr)(saddr, smask, rnh, np->netc_rnodes);
169 RADIX_NODE_HEAD_UNLOCK(rnh);
170 if (rn == NULL || np != (struct netcred *)rn) { /* already exists */
171 error = EPERM;
172 goto out;
173 }
174 np->netc_exflags = argp->ex_flags;
175 bzero(&np->netc_anon, sizeof(np->netc_anon));
176 np->netc_anon.cr_uid = argp->ex_anon.cr_uid;
177 np->netc_anon.cr_ngroups = argp->ex_anon.cr_ngroups;
178 bcopy(argp->ex_anon.cr_groups, np->netc_anon.cr_groups,
179 sizeof(np->netc_anon.cr_groups));
180 refcount_init(&np->netc_anon.cr_ref, 1);
181 return (0);
182 out:
183 free(np, M_NETADDR);
184 return (error);
185 }
186
187 /* Helper for vfs_free_addrlist. */
188 /* ARGSUSED */
189 static int
190 vfs_free_netcred(rn, w)
191 struct radix_node *rn;
192 void *w;
193 {
194 register struct radix_node_head *rnh = (struct radix_node_head *) w;
195
196 (*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh);
197 free(rn, M_NETADDR);
198 return (0);
199 }
200
201 /*
202 * Free the net address hash lists that are hanging off the mount points.
203 */
204 static void
205 vfs_free_addrlist(nep)
206 struct netexport *nep;
207 {
208 register int i;
209 register struct radix_node_head *rnh;
210
211 for (i = 0; i <= AF_MAX; i++)
212 if ((rnh = nep->ne_rtable[i])) {
213 RADIX_NODE_HEAD_LOCK(rnh);
214 (*rnh->rnh_walktree) (rnh, vfs_free_netcred, rnh);
215 RADIX_NODE_HEAD_DESTROY(rnh);
216 free(rnh, M_RTABLE);
217 nep->ne_rtable[i] = NULL; /* not SMP safe XXX */
218 }
219 }
220
221 /*
222 * High level function to manipulate export options on a mount point
223 * and the passed in netexport.
224 * Struct export_args *argp is the variable used to twiddle options,
225 * the structure is described in sys/mount.h
226 */
227 int
228 vfs_export(mp, argp)
229 struct mount *mp;
230 struct export_args *argp;
231 {
232 struct netexport *nep;
233 int error;
234
235 nep = mp->mnt_export;
236 if (argp->ex_flags & MNT_DELEXPORT) {
237 if (nep == NULL)
238 return (ENOENT);
239 if (mp->mnt_flag & MNT_EXPUBLIC) {
240 vfs_setpublicfs(NULL, NULL, NULL);
241 MNT_ILOCK(mp);
242 mp->mnt_flag &= ~MNT_EXPUBLIC;
243 MNT_IUNLOCK(mp);
244 }
245 vfs_free_addrlist(nep);
246 mp->mnt_export = NULL;
247 free(nep, M_MOUNT);
248 nep = NULL;
249 MNT_ILOCK(mp);
250 mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
251 MNT_IUNLOCK(mp);
252 }
253 if (argp->ex_flags & MNT_EXPORTED) {
254 if (nep == NULL) {
255 nep = malloc(sizeof(struct netexport), M_MOUNT, M_WAITOK | M_ZERO);
256 mp->mnt_export = nep;
257 }
258 if (argp->ex_flags & MNT_EXPUBLIC) {
259 if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
260 return (error);
261 MNT_ILOCK(mp);
262 mp->mnt_flag |= MNT_EXPUBLIC;
263 MNT_IUNLOCK(mp);
264 }
265 if ((error = vfs_hang_addrlist(mp, nep, argp)))
266 return (error);
267 MNT_ILOCK(mp);
268 mp->mnt_flag |= MNT_EXPORTED;
269 MNT_IUNLOCK(mp);
270 }
271 return (0);
272 }
273
274 /*
275 * Set the publicly exported filesystem (WebNFS). Currently, only
276 * one public filesystem is possible in the spec (RFC 2054 and 2055)
277 */
278 int
279 vfs_setpublicfs(mp, nep, argp)
280 struct mount *mp;
281 struct netexport *nep;
282 struct export_args *argp;
283 {
284 int error;
285 struct vnode *rvp;
286 char *cp;
287
288 /*
289 * mp == NULL -> invalidate the current info, the FS is
290 * no longer exported. May be called from either vfs_export
291 * or unmount, so check if it hasn't already been done.
292 */
293 if (mp == NULL) {
294 if (nfs_pub.np_valid) {
295 nfs_pub.np_valid = 0;
296 if (nfs_pub.np_index != NULL) {
297 FREE(nfs_pub.np_index, M_TEMP);
298 nfs_pub.np_index = NULL;
299 }
300 }
301 return (0);
302 }
303
304 /*
305 * Only one allowed at a time.
306 */
307 if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
308 return (EBUSY);
309
310 /*
311 * Get real filehandle for root of exported FS.
312 */
313 bzero(&nfs_pub.np_handle, sizeof(nfs_pub.np_handle));
314 nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
315
316 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rvp, curthread /* XXX */)))
317 return (error);
318
319 if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
320 return (error);
321
322 vput(rvp);
323
324 /*
325 * If an indexfile was specified, pull it in.
326 */
327 if (argp->ex_indexfile != NULL) {
328 MALLOC(nfs_pub.np_index, char *, MAXNAMLEN + 1, M_TEMP,
329 M_WAITOK);
330 error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
331 MAXNAMLEN, (size_t *)0);
332 if (!error) {
333 /*
334 * Check for illegal filenames.
335 */
336 for (cp = nfs_pub.np_index; *cp; cp++) {
337 if (*cp == '/') {
338 error = EINVAL;
339 break;
340 }
341 }
342 }
343 if (error) {
344 FREE(nfs_pub.np_index, M_TEMP);
345 return (error);
346 }
347 }
348
349 nfs_pub.np_mount = mp;
350 nfs_pub.np_valid = 1;
351 return (0);
352 }
353
354 /*
355 * Used by the filesystems to determine if a given network address
356 * (passed in 'nam') is present in thier exports list, returns a pointer
357 * to struct netcred so that the filesystem can examine it for
358 * access rights (read/write/etc).
359 */
360 static struct netcred *
361 vfs_export_lookup(struct mount *mp, struct sockaddr *nam)
362 {
363 struct netexport *nep;
364 register struct netcred *np;
365 register struct radix_node_head *rnh;
366 struct sockaddr *saddr;
367
368 nep = mp->mnt_export;
369 if (nep == NULL)
370 return (NULL);
371 np = NULL;
372 if (mp->mnt_flag & MNT_EXPORTED) {
373 /*
374 * Lookup in the export list first.
375 */
376 if (nam != NULL) {
377 saddr = nam;
378 rnh = nep->ne_rtable[saddr->sa_family];
379 if (rnh != NULL) {
380 RADIX_NODE_HEAD_LOCK(rnh);
381 np = (struct netcred *)
382 (*rnh->rnh_matchaddr)(saddr, rnh);
383 RADIX_NODE_HEAD_UNLOCK(rnh);
384 if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
385 np = NULL;
386 }
387 }
388 /*
389 * If no address match, use the default if it exists.
390 */
391 if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED)
392 np = &nep->ne_defexported;
393 }
394 return (np);
395 }
396
397 /*
398 * XXX: This comment comes from the deprecated ufs_check_export()
399 * XXX: and may not entirely apply, but lacking something better:
400 * This is the generic part of fhtovp called after the underlying
401 * filesystem has validated the file handle.
402 *
403 * Verify that a host should have access to a filesystem.
404 */
405
406 int
407 vfs_stdcheckexp(mp, nam, extflagsp, credanonp)
408 struct mount *mp;
409 struct sockaddr *nam;
410 int *extflagsp;
411 struct ucred **credanonp;
412 {
413 struct netcred *np;
414
415 np = vfs_export_lookup(mp, nam);
416 if (np == NULL)
417 return (EACCES);
418 *extflagsp = np->netc_exflags;
419 *credanonp = &np->netc_anon;
420 return (0);
421 }
422
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