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: src/sys/kern/vfs_export.c,v 1.327.2.2 2005/01/31 23:26:18 imp Exp $");
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/socket.h>
50 #include <sys/systm.h>
51 #include <sys/vnode.h>
52
53 #include <net/radix.h>
54
55 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
56
57 static void vfs_free_addrlist(struct netexport *nep);
58 static int vfs_free_netcred(struct radix_node *rn, void *w);
59 static int vfs_hang_addrlist(struct mount *mp, struct netexport *nep,
60 struct export_args *argp);
61
62 /*
63 * Network address lookup element
64 */
65 struct netcred {
66 struct radix_node netc_rnodes[2];
67 int netc_exflags;
68 struct ucred netc_anon;
69 };
70
71 /*
72 * Network export information
73 */
74 struct netexport {
75 struct netcred ne_defexported; /* Default export */
76 struct radix_node_head *ne_rtable[AF_MAX+1]; /* Individual exports */
77 };
78
79 /*
80 * Build hash lists of net addresses and hang them off the mount point.
81 * Called by ufs_mount() to set up the lists of export addresses.
82 */
83 static int
84 vfs_hang_addrlist(mp, nep, argp)
85 struct mount *mp;
86 struct netexport *nep;
87 struct export_args *argp;
88 {
89 register struct netcred *np;
90 register struct radix_node_head *rnh;
91 register int i;
92 struct radix_node *rn;
93 struct sockaddr *saddr, *smask = 0;
94 struct domain *dom;
95 int error;
96
97 /*
98 * XXX: This routine converts from a `struct xucred'
99 * (argp->ex_anon) to a `struct ucred' (np->netc_anon). This
100 * operation is questionable; for example, what should be done
101 * with fields like cr_uidinfo and cr_prison? Currently, this
102 * routine does not touch them (leaves them as NULL).
103 */
104 if (argp->ex_anon.cr_version != XUCRED_VERSION)
105 return (EINVAL);
106
107 if (argp->ex_addrlen == 0) {
108 if (mp->mnt_flag & MNT_DEFEXPORTED)
109 return (EPERM);
110 np = &nep->ne_defexported;
111 np->netc_exflags = argp->ex_flags;
112 bzero(&np->netc_anon, sizeof(np->netc_anon));
113 np->netc_anon.cr_uid = argp->ex_anon.cr_uid;
114 np->netc_anon.cr_ngroups = argp->ex_anon.cr_ngroups;
115 bcopy(argp->ex_anon.cr_groups, np->netc_anon.cr_groups,
116 sizeof(np->netc_anon.cr_groups));
117 np->netc_anon.cr_ref = 1;
118 mp->mnt_flag |= MNT_DEFEXPORTED;
119 return (0);
120 }
121
122 #if MSIZE <= 256
123 if (argp->ex_addrlen > MLEN)
124 return (EINVAL);
125 #endif
126
127 i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
128 np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK | M_ZERO);
129 saddr = (struct sockaddr *) (np + 1);
130 if ((error = copyin(argp->ex_addr, saddr, argp->ex_addrlen)))
131 goto out;
132 if (saddr->sa_family > AF_MAX) {
133 error = EINVAL;
134 goto out;
135 }
136 if (saddr->sa_len > argp->ex_addrlen)
137 saddr->sa_len = argp->ex_addrlen;
138 if (argp->ex_masklen) {
139 smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen);
140 error = copyin(argp->ex_mask, smask, argp->ex_masklen);
141 if (error)
142 goto out;
143 if (smask->sa_len > argp->ex_masklen)
144 smask->sa_len = argp->ex_masklen;
145 }
146 i = saddr->sa_family;
147 if ((rnh = nep->ne_rtable[i]) == NULL) {
148 /*
149 * Seems silly to initialize every AF when most are not used,
150 * do so on demand here
151 */
152 for (dom = domains; dom; dom = dom->dom_next)
153 if (dom->dom_family == i && dom->dom_rtattach) {
154 dom->dom_rtattach((void **) &nep->ne_rtable[i],
155 dom->dom_rtoffset);
156 break;
157 }
158 if ((rnh = nep->ne_rtable[i]) == NULL) {
159 error = ENOBUFS;
160 goto out;
161 }
162 }
163 RADIX_NODE_HEAD_LOCK(rnh);
164 rn = (*rnh->rnh_addaddr)(saddr, smask, rnh, np->netc_rnodes);
165 RADIX_NODE_HEAD_UNLOCK(rnh);
166 if (rn == NULL || np != (struct netcred *)rn) { /* already exists */
167 error = EPERM;
168 goto out;
169 }
170 np->netc_exflags = argp->ex_flags;
171 bzero(&np->netc_anon, sizeof(np->netc_anon));
172 np->netc_anon.cr_uid = argp->ex_anon.cr_uid;
173 np->netc_anon.cr_ngroups = argp->ex_anon.cr_ngroups;
174 bcopy(argp->ex_anon.cr_groups, np->netc_anon.cr_groups,
175 sizeof(np->netc_anon.cr_groups));
176 np->netc_anon.cr_ref = 1;
177 return (0);
178 out:
179 free(np, M_NETADDR);
180 return (error);
181 }
182
183 /* Helper for vfs_free_addrlist. */
184 /* ARGSUSED */
185 static int
186 vfs_free_netcred(rn, w)
187 struct radix_node *rn;
188 void *w;
189 {
190 register struct radix_node_head *rnh = (struct radix_node_head *) w;
191
192 (*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh);
193 free(rn, M_NETADDR);
194 return (0);
195 }
196
197 /*
198 * Free the net address hash lists that are hanging off the mount points.
199 */
200 static void
201 vfs_free_addrlist(nep)
202 struct netexport *nep;
203 {
204 register int i;
205 register struct radix_node_head *rnh;
206
207 for (i = 0; i <= AF_MAX; i++)
208 if ((rnh = nep->ne_rtable[i])) {
209 RADIX_NODE_HEAD_LOCK(rnh);
210 (*rnh->rnh_walktree) (rnh, vfs_free_netcred, rnh);
211 RADIX_NODE_HEAD_DESTROY(rnh);
212 free(rnh, M_RTABLE);
213 nep->ne_rtable[i] = NULL; /* not SMP safe XXX */
214 }
215 }
216
217 /*
218 * High level function to manipulate export options on a mount point
219 * and the passed in netexport.
220 * Struct export_args *argp is the variable used to twiddle options,
221 * the structure is described in sys/mount.h
222 */
223 int
224 vfs_export(mp, argp)
225 struct mount *mp;
226 struct export_args *argp;
227 {
228 struct netexport *nep;
229 int error;
230
231 nep = mp->mnt_export;
232 if (argp->ex_flags & MNT_DELEXPORT) {
233 if (nep == NULL)
234 return (ENOENT);
235 if (mp->mnt_flag & MNT_EXPUBLIC) {
236 vfs_setpublicfs(NULL, NULL, NULL);
237 mp->mnt_flag &= ~MNT_EXPUBLIC;
238 }
239 vfs_free_addrlist(nep);
240 mp->mnt_export = NULL;
241 free(nep, M_MOUNT);
242 mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
243 }
244 if (argp->ex_flags & MNT_EXPORTED) {
245 if (nep == NULL) {
246 nep = malloc(sizeof(struct netexport), M_MOUNT, M_WAITOK | M_ZERO);
247 mp->mnt_export = nep;
248 }
249 if (argp->ex_flags & MNT_EXPUBLIC) {
250 if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
251 return (error);
252 mp->mnt_flag |= MNT_EXPUBLIC;
253 }
254 if ((error = vfs_hang_addrlist(mp, nep, argp)))
255 return (error);
256 mp->mnt_flag |= MNT_EXPORTED;
257 }
258 return (0);
259 }
260
261 /*
262 * Set the publicly exported filesystem (WebNFS). Currently, only
263 * one public filesystem is possible in the spec (RFC 2054 and 2055)
264 */
265 int
266 vfs_setpublicfs(mp, nep, argp)
267 struct mount *mp;
268 struct netexport *nep;
269 struct export_args *argp;
270 {
271 int error;
272 struct vnode *rvp;
273 char *cp;
274
275 /*
276 * mp == NULL -> invalidate the current info, the FS is
277 * no longer exported. May be called from either vfs_export
278 * or unmount, so check if it hasn't already been done.
279 */
280 if (mp == NULL) {
281 if (nfs_pub.np_valid) {
282 nfs_pub.np_valid = 0;
283 if (nfs_pub.np_index != NULL) {
284 FREE(nfs_pub.np_index, M_TEMP);
285 nfs_pub.np_index = NULL;
286 }
287 }
288 return (0);
289 }
290
291 /*
292 * Only one allowed at a time.
293 */
294 if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
295 return (EBUSY);
296
297 /*
298 * Get real filehandle for root of exported FS.
299 */
300 bzero(&nfs_pub.np_handle, sizeof(nfs_pub.np_handle));
301 nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
302
303 if ((error = VFS_ROOT(mp, &rvp, curthread /* XXX */)))
304 return (error);
305
306 if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
307 return (error);
308
309 vput(rvp);
310
311 /*
312 * If an indexfile was specified, pull it in.
313 */
314 if (argp->ex_indexfile != NULL) {
315 MALLOC(nfs_pub.np_index, char *, MAXNAMLEN + 1, M_TEMP,
316 M_WAITOK);
317 error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
318 MAXNAMLEN, (size_t *)0);
319 if (!error) {
320 /*
321 * Check for illegal filenames.
322 */
323 for (cp = nfs_pub.np_index; *cp; cp++) {
324 if (*cp == '/') {
325 error = EINVAL;
326 break;
327 }
328 }
329 }
330 if (error) {
331 FREE(nfs_pub.np_index, M_TEMP);
332 return (error);
333 }
334 }
335
336 nfs_pub.np_mount = mp;
337 nfs_pub.np_valid = 1;
338 return (0);
339 }
340
341 /*
342 * Used by the filesystems to determine if a given network address
343 * (passed in 'nam') is present in thier exports list, returns a pointer
344 * to struct netcred so that the filesystem can examine it for
345 * access rights (read/write/etc).
346 */
347 struct netcred *
348 vfs_export_lookup(mp, nam)
349 register struct mount *mp;
350 struct sockaddr *nam;
351 {
352 struct netexport *nep;
353 register struct netcred *np;
354 register struct radix_node_head *rnh;
355 struct sockaddr *saddr;
356
357 nep = mp->mnt_export;
358 if (nep == NULL)
359 return (NULL);
360 np = NULL;
361 if (mp->mnt_flag & MNT_EXPORTED) {
362 /*
363 * Lookup in the export list first.
364 */
365 if (nam != NULL) {
366 saddr = nam;
367 rnh = nep->ne_rtable[saddr->sa_family];
368 if (rnh != NULL) {
369 RADIX_NODE_HEAD_LOCK(rnh);
370 np = (struct netcred *)
371 (*rnh->rnh_matchaddr)(saddr, rnh);
372 RADIX_NODE_HEAD_UNLOCK(rnh);
373 if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
374 np = NULL;
375 }
376 }
377 /*
378 * If no address match, use the default if it exists.
379 */
380 if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED)
381 np = &nep->ne_defexported;
382 }
383 return (np);
384 }
385
386 /*
387 * XXX: This comment comes from the deprecated ufs_check_export()
388 * XXX: and may not entirely apply, but lacking something better:
389 * This is the generic part of fhtovp called after the underlying
390 * filesystem has validated the file handle.
391 *
392 * Verify that a host should have access to a filesystem.
393 */
394
395 int
396 vfs_stdcheckexp(mp, nam, extflagsp, credanonp)
397 struct mount *mp;
398 struct sockaddr *nam;
399 int *extflagsp;
400 struct ucred **credanonp;
401 {
402 struct netcred *np;
403
404 np = vfs_export_lookup(mp, nam);
405 if (np == NULL)
406 return (EACCES);
407 *extflagsp = np->netc_exflags;
408 *credanonp = &np->netc_anon;
409 return (0);
410 }
411
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