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("$FreeBSD$");
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
183 out:
184 free(np, M_NETADDR);
185 return (error);
186 }
187
188 /* Helper for vfs_free_addrlist. */
189 /* ARGSUSED */
190 static int
191 vfs_free_netcred(rn, w)
192 struct radix_node *rn;
193 void *w;
194 {
195 register struct radix_node_head *rnh = (struct radix_node_head *) w;
196
197 (*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh);
198 free(rn, M_NETADDR);
199 return (0);
200 }
201
202 /*
203 * Free the net address hash lists that are hanging off the mount points.
204 */
205 static void
206 vfs_free_addrlist(nep)
207 struct netexport *nep;
208 {
209 register int i;
210 register struct radix_node_head *rnh;
211
212 for (i = 0; i <= AF_MAX; i++)
213 if ((rnh = nep->ne_rtable[i])) {
214 RADIX_NODE_HEAD_LOCK(rnh);
215 (*rnh->rnh_walktree) (rnh, vfs_free_netcred, rnh);
216 RADIX_NODE_HEAD_DESTROY(rnh);
217 free(rnh, M_RTABLE);
218 nep->ne_rtable[i] = NULL; /* not SMP safe XXX */
219 }
220 }
221
222 /*
223 * High level function to manipulate export options on a mount point
224 * and the passed in netexport.
225 * Struct export_args *argp is the variable used to twiddle options,
226 * the structure is described in sys/mount.h
227 */
228 int
229 vfs_export(mp, argp)
230 struct mount *mp;
231 struct export_args *argp;
232 {
233 struct netexport *nep;
234 int error;
235
236 error = 0;
237 lockmgr(&mp->mnt_explock, LK_EXCLUSIVE, NULL, curthread);
238 nep = mp->mnt_export;
239 if (argp->ex_flags & MNT_DELEXPORT) {
240 if (nep == NULL) {
241 error = ENOENT;
242 goto out;
243 }
244 if (mp->mnt_flag & MNT_EXPUBLIC) {
245 vfs_setpublicfs(NULL, NULL, NULL);
246 MNT_ILOCK(mp);
247 mp->mnt_flag &= ~MNT_EXPUBLIC;
248 MNT_IUNLOCK(mp);
249 }
250 vfs_free_addrlist(nep);
251 mp->mnt_export = NULL;
252 free(nep, M_MOUNT);
253 nep = NULL;
254 MNT_ILOCK(mp);
255 mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
256 MNT_IUNLOCK(mp);
257 }
258 if (argp->ex_flags & MNT_EXPORTED) {
259 if (nep == NULL) {
260 nep = malloc(sizeof(struct netexport), M_MOUNT, M_WAITOK | M_ZERO);
261 mp->mnt_export = nep;
262 }
263 if (argp->ex_flags & MNT_EXPUBLIC) {
264 if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
265 goto out;
266 MNT_ILOCK(mp);
267 mp->mnt_flag |= MNT_EXPUBLIC;
268 MNT_IUNLOCK(mp);
269 }
270 if ((error = vfs_hang_addrlist(mp, nep, argp)))
271 goto out;
272 MNT_ILOCK(mp);
273 mp->mnt_flag |= MNT_EXPORTED;
274 MNT_IUNLOCK(mp);
275 }
276 out:
277 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL, curthread);
278 return (error);
279 }
280
281 /*
282 * Set the publicly exported filesystem (WebNFS). Currently, only
283 * one public filesystem is possible in the spec (RFC 2054 and 2055)
284 */
285 int
286 vfs_setpublicfs(mp, nep, argp)
287 struct mount *mp;
288 struct netexport *nep;
289 struct export_args *argp;
290 {
291 int error;
292 struct vnode *rvp;
293 char *cp;
294
295 /*
296 * mp == NULL -> invalidate the current info, the FS is
297 * no longer exported. May be called from either vfs_export
298 * or unmount, so check if it hasn't already been done.
299 */
300 if (mp == NULL) {
301 if (nfs_pub.np_valid) {
302 nfs_pub.np_valid = 0;
303 if (nfs_pub.np_index != NULL) {
304 FREE(nfs_pub.np_index, M_TEMP);
305 nfs_pub.np_index = NULL;
306 }
307 }
308 return (0);
309 }
310
311 /*
312 * Only one allowed at a time.
313 */
314 if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
315 return (EBUSY);
316
317 /*
318 * Get real filehandle for root of exported FS.
319 */
320 bzero(&nfs_pub.np_handle, sizeof(nfs_pub.np_handle));
321 nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
322
323 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rvp, curthread /* XXX */)))
324 return (error);
325
326 if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
327 return (error);
328
329 vput(rvp);
330
331 /*
332 * If an indexfile was specified, pull it in.
333 */
334 if (argp->ex_indexfile != NULL) {
335 MALLOC(nfs_pub.np_index, char *, MAXNAMLEN + 1, M_TEMP,
336 M_WAITOK);
337 error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
338 MAXNAMLEN, (size_t *)0);
339 if (!error) {
340 /*
341 * Check for illegal filenames.
342 */
343 for (cp = nfs_pub.np_index; *cp; cp++) {
344 if (*cp == '/') {
345 error = EINVAL;
346 break;
347 }
348 }
349 }
350 if (error) {
351 FREE(nfs_pub.np_index, M_TEMP);
352 return (error);
353 }
354 }
355
356 nfs_pub.np_mount = mp;
357 nfs_pub.np_valid = 1;
358 return (0);
359 }
360
361 /*
362 * Used by the filesystems to determine if a given network address
363 * (passed in 'nam') is present in thier exports list, returns a pointer
364 * to struct netcred so that the filesystem can examine it for
365 * access rights (read/write/etc).
366 */
367 static struct netcred *
368 vfs_export_lookup(struct mount *mp, struct sockaddr *nam)
369 {
370 struct netexport *nep;
371 register struct netcred *np;
372 register struct radix_node_head *rnh;
373 struct sockaddr *saddr;
374
375 nep = mp->mnt_export;
376 if (nep == NULL)
377 return (NULL);
378 np = NULL;
379 if (mp->mnt_flag & MNT_EXPORTED) {
380 /*
381 * Lookup in the export list first.
382 */
383 if (nam != NULL) {
384 saddr = nam;
385 rnh = nep->ne_rtable[saddr->sa_family];
386 if (rnh != NULL) {
387 RADIX_NODE_HEAD_LOCK(rnh);
388 np = (struct netcred *)
389 (*rnh->rnh_matchaddr)(saddr, rnh);
390 RADIX_NODE_HEAD_UNLOCK(rnh);
391 if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
392 np = NULL;
393 }
394 }
395 /*
396 * If no address match, use the default if it exists.
397 */
398 if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED)
399 np = &nep->ne_defexported;
400 }
401 return (np);
402 }
403
404 /*
405 * XXX: This comment comes from the deprecated ufs_check_export()
406 * XXX: and may not entirely apply, but lacking something better:
407 * This is the generic part of fhtovp called after the underlying
408 * filesystem has validated the file handle.
409 *
410 * Verify that a host should have access to a filesystem.
411 */
412
413 int
414 vfs_stdcheckexp(mp, nam, extflagsp, credanonp)
415 struct mount *mp;
416 struct sockaddr *nam;
417 int *extflagsp;
418 struct ucred **credanonp;
419 {
420 struct netcred *np;
421
422 lockmgr(&mp->mnt_explock, LK_SHARED, NULL, curthread);
423 np = vfs_export_lookup(mp, nam);
424 lockmgr(&mp->mnt_explock, LK_RELEASE, NULL, curthread);
425 if (np == NULL)
426 return (EACCES);
427 *extflagsp = np->netc_exflags;
428 *credanonp = &np->netc_anon;
429 return (0);
430 }
431
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