nfs_srvsubs.c revision 1.10 1 /* $NetBSD: nfs_srvsubs.c,v 1.10 2011/04/11 01:33:05 dholland Exp $ */
2
3 /*
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Rick Macklem at The University of Guelph.
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 * 3. 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 * @(#)nfs_subs.c 8.8 (Berkeley) 5/22/95
35 */
36
37 /*
38 * Copyright 2000 Wasabi Systems, Inc.
39 * All rights reserved.
40 *
41 * Written by Frank van der Linden for Wasabi Systems, Inc.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 * notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 * notice, this list of conditions and the following disclaimer in the
50 * documentation and/or other materials provided with the distribution.
51 * 3. All advertising materials mentioning features or use of this software
52 * must display the following acknowledgement:
53 * This product includes software developed for the NetBSD Project by
54 * Wasabi Systems, Inc.
55 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
56 * or promote products derived from this software without specific prior
57 * written permission.
58 *
59 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
61 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
62 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
63 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
64 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
65 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
66 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
67 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
68 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
69 * POSSIBILITY OF SUCH DAMAGE.
70 */
71
72 #include <sys/cdefs.h>
73 __KERNEL_RCSID(0, "$NetBSD: nfs_srvsubs.c,v 1.10 2011/04/11 01:33:05 dholland Exp $");
74
75 #include <sys/param.h>
76 #include <sys/proc.h>
77 #include <sys/systm.h>
78 #include <sys/kernel.h>
79 #include <sys/kmem.h>
80 #include <sys/mount.h>
81 #include <sys/vnode.h>
82 #include <sys/namei.h>
83 #include <sys/mbuf.h>
84 #include <sys/socket.h>
85 #include <sys/stat.h>
86 #include <sys/filedesc.h>
87 #include <sys/time.h>
88 #include <sys/dirent.h>
89 #include <sys/once.h>
90 #include <sys/kauth.h>
91 #include <sys/atomic.h>
92
93 #include <uvm/uvm_extern.h>
94
95 #include <nfs/rpcv2.h>
96 #include <nfs/nfsproto.h>
97 #include <nfs/nfsnode.h>
98 #include <nfs/nfs.h>
99 #include <nfs/xdr_subs.h>
100 #include <nfs/nfsm_subs.h>
101 #include <nfs/nfsmount.h>
102 #include <nfs/nfsrtt.h>
103 #include <nfs/nfs_var.h>
104
105 #include <miscfs/specfs/specdev.h>
106
107 #include <netinet/in.h>
108
109 /*
110 * Set up nameidata for a lookup() call and do it.
111 *
112 * If pubflag is set, this call is done for a lookup operation on the
113 * public filehandle. In that case we allow crossing mountpoints and
114 * absolute pathnames. However, the caller is expected to check that
115 * the lookup result is within the public fs, and deny access if
116 * it is not.
117 */
118 int
119 nfs_namei(struct nameidata *ndp, nfsrvfh_t *nsfh, uint32_t len, struct nfssvc_sock *slp, struct mbuf *nam, struct mbuf **mdp, char **dposp, struct vnode **retdirp, struct lwp *l, int kerbflag, int pubflag)
120 {
121 int i, rem;
122 struct mbuf *md;
123 char *fromcp, *tocp, *cp, *path;
124 struct vnode *dp;
125 int error, rdonly;
126 int neverfollow;
127 struct componentname *cnp = &ndp->ni_cnd;
128
129 *retdirp = NULL;
130 ndp->ni_pathbuf = NULL;
131
132 if ((len + 1) > MAXPATHLEN)
133 return (ENAMETOOLONG);
134 if (len == 0)
135 return (EACCES);
136
137 /*
138 * Copy the name from the mbuf list to ndp->ni_pathbuf
139 * and set the various ndp fields appropriately.
140 */
141 path = PNBUF_GET();
142 fromcp = *dposp;
143 tocp = path;
144 md = *mdp;
145 rem = mtod(md, char *) + md->m_len - fromcp;
146 for (i = 0; i < len; i++) {
147 while (rem == 0) {
148 md = md->m_next;
149 if (md == NULL) {
150 error = EBADRPC;
151 goto out;
152 }
153 fromcp = mtod(md, void *);
154 rem = md->m_len;
155 }
156 if (*fromcp == '\0' || (!pubflag && *fromcp == '/')) {
157 error = EACCES;
158 goto out;
159 }
160 *tocp++ = *fromcp++;
161 rem--;
162 }
163 *tocp = '\0';
164 *mdp = md;
165 *dposp = fromcp;
166 len = nfsm_rndup(len)-len;
167 if (len > 0) {
168 if (rem >= len)
169 *dposp += len;
170 else if ((error = nfs_adv(mdp, dposp, len, rem)) != 0)
171 goto out;
172 }
173
174 /*
175 * Extract and set starting directory.
176 */
177 error = nfsrv_fhtovp(nsfh, false, &dp, ndp->ni_cnd.cn_cred, slp,
178 nam, &rdonly, kerbflag, pubflag);
179 if (error)
180 goto out;
181 if (dp->v_type != VDIR) {
182 vrele(dp);
183 error = ENOTDIR;
184 goto out;
185 }
186
187 if (rdonly)
188 cnp->cn_flags |= RDONLY;
189
190 *retdirp = dp;
191
192 if (pubflag) {
193 /*
194 * Oh joy. For WebNFS, handle those pesky '%' escapes,
195 * and the 'native path' indicator.
196 */
197 cp = PNBUF_GET();
198 fromcp = path;
199 tocp = cp;
200 if ((unsigned char)*fromcp >= WEBNFS_SPECCHAR_START) {
201 switch ((unsigned char)*fromcp) {
202 case WEBNFS_NATIVE_CHAR:
203 /*
204 * 'Native' path for us is the same
205 * as a path according to the NFS spec,
206 * just skip the escape char.
207 */
208 fromcp++;
209 break;
210 /*
211 * More may be added in the future, range 0x80-0xff
212 */
213 default:
214 error = EIO;
215 vrele(dp);
216 PNBUF_PUT(cp);
217 goto out;
218 }
219 }
220 /*
221 * Translate the '%' escapes, URL-style.
222 */
223 while (*fromcp != '\0') {
224 if (*fromcp == WEBNFS_ESC_CHAR) {
225 if (fromcp[1] != '\0' && fromcp[2] != '\0') {
226 fromcp++;
227 *tocp++ = HEXSTRTOI(fromcp);
228 fromcp += 2;
229 continue;
230 } else {
231 error = ENOENT;
232 vrele(dp);
233 PNBUF_PUT(cp);
234 goto out;
235 }
236 } else
237 *tocp++ = *fromcp++;
238 }
239 *tocp = '\0';
240 PNBUF_PUT(path);
241 path = cp;
242 }
243
244 ndp->ni_pathbuf = pathbuf_assimilate(path);
245 if (ndp->ni_pathbuf == NULL) {
246 error = ENOMEM;
247 goto out;
248 }
249
250 if (pubflag) {
251 if (path[0] == '/')
252 dp = rootvnode;
253 } else {
254 cnp->cn_flags |= NOCROSSMOUNT;
255 }
256
257 neverfollow = !pubflag;
258
259 /*
260 * And call lookup() to do the real work
261 *
262 * Note: ndp->ni_pathbuf is left undestroyed; caller must
263 * clean it up.
264 */
265 error = lookup_for_nfsd(ndp, dp, neverfollow);
266 if (error) {
267 return (error);
268 }
269 return 0;
270
271 out:
272 if (ndp->ni_pathbuf != NULL) {
273 pathbuf_destroy(ndp->ni_pathbuf);
274 ndp->ni_pathbuf = NULL;
275 } else {
276 PNBUF_PUT(path);
277 }
278 return (error);
279 }
280
281 /*
282 * nfsrv_fhtovp() - convert a fh to a vnode ptr (optionally locked)
283 * - look up fsid in mount list (if not found ret error)
284 * - get vp and export rights by calling VFS_FHTOVP()
285 * - if cred->cr_uid == 0 or MNT_EXPORTANON set it to credanon
286 * - if not lockflag unlock it with VOP_UNLOCK()
287 */
288 int
289 nfsrv_fhtovp(nfsrvfh_t *nsfh, int lockflag, struct vnode **vpp,
290 kauth_cred_t cred, struct nfssvc_sock *slp, struct mbuf *nam, int *rdonlyp,
291 int kerbflag, int pubflag)
292 {
293 struct mount *mp;
294 kauth_cred_t credanon;
295 int error, exflags;
296 struct sockaddr_in *saddr;
297 fhandle_t *fhp;
298
299 fhp = NFSRVFH_FHANDLE(nsfh);
300 *vpp = (struct vnode *)0;
301
302 if (nfs_ispublicfh(nsfh)) {
303 if (!pubflag || !nfs_pub.np_valid)
304 return (ESTALE);
305 fhp = nfs_pub.np_handle;
306 }
307
308 error = netexport_check(&fhp->fh_fsid, nam, &mp, &exflags, &credanon);
309 if (error) {
310 return error;
311 }
312
313 error = VFS_FHTOVP(mp, &fhp->fh_fid, vpp);
314 if (error)
315 return (error);
316
317 if (!(exflags & (MNT_EXNORESPORT|MNT_EXPUBLIC))) {
318 saddr = mtod(nam, struct sockaddr_in *);
319 if ((saddr->sin_family == AF_INET) &&
320 ntohs(saddr->sin_port) >= IPPORT_RESERVED) {
321 vput(*vpp);
322 return (NFSERR_AUTHERR | AUTH_TOOWEAK);
323 }
324 if ((saddr->sin_family == AF_INET6) &&
325 ntohs(saddr->sin_port) >= IPV6PORT_RESERVED) {
326 vput(*vpp);
327 return (NFSERR_AUTHERR | AUTH_TOOWEAK);
328 }
329 }
330 /*
331 * Check/setup credentials.
332 */
333 if (exflags & MNT_EXKERB) {
334 if (!kerbflag) {
335 vput(*vpp);
336 return (NFSERR_AUTHERR | AUTH_TOOWEAK);
337 }
338 } else if (kerbflag) {
339 vput(*vpp);
340 return (NFSERR_AUTHERR | AUTH_TOOWEAK);
341 } else if (kauth_cred_geteuid(cred) == 0 || /* NFS maproot, see below */
342 (exflags & MNT_EXPORTANON)) {
343 /*
344 * This is used by the NFS maproot option. While we can change
345 * the secmodel on our own host, we can't change it on the
346 * clients. As means of least surprise, we're doing the
347 * traditional thing here.
348 * Should look into adding a "mapprivileged" or similar where
349 * the users can be explicitly specified...
350 * [elad, yamt 2008-03-05]
351 */
352 kauth_cred_clone(credanon, cred);
353 }
354 if (exflags & MNT_EXRDONLY)
355 *rdonlyp = 1;
356 else
357 *rdonlyp = 0;
358 if (!lockflag)
359 VOP_UNLOCK(*vpp);
360 return (0);
361 }
362
363 /*
364 * WebNFS: check if a filehandle is a public filehandle. For v3, this
365 * means a length of 0, for v2 it means all zeroes.
366 */
367 int
368 nfs_ispublicfh(const nfsrvfh_t *nsfh)
369 {
370 const char *cp = (const void *)(NFSRVFH_DATA(nsfh));
371 int i;
372
373 if (NFSRVFH_SIZE(nsfh) == 0) {
374 return true;
375 }
376 if (NFSRVFH_SIZE(nsfh) != NFSX_V2FH) {
377 return false;
378 }
379 for (i = 0; i < NFSX_V2FH; i++)
380 if (*cp++ != 0)
381 return false;
382 return true;
383 }
384
385 int
386 nfsrv_composefh(struct vnode *vp, nfsrvfh_t *nsfh, bool v3)
387 {
388 int error;
389 size_t fhsize;
390
391 fhsize = NFSD_MAXFHSIZE;
392 error = vfs_composefh(vp, (void *)NFSRVFH_DATA(nsfh), &fhsize);
393 if (NFSX_FHTOOBIG_P(fhsize, v3)) {
394 error = EOPNOTSUPP;
395 }
396 if (error != 0) {
397 return error;
398 }
399 if (!v3 && fhsize < NFSX_V2FH) {
400 memset((char *)NFSRVFH_DATA(nsfh) + fhsize, 0,
401 NFSX_V2FH - fhsize);
402 fhsize = NFSX_V2FH;
403 }
404 if ((fhsize % NFSX_UNSIGNED) != 0) {
405 return EOPNOTSUPP;
406 }
407 nsfh->nsfh_size = fhsize;
408 return 0;
409 }
410
411 int
412 nfsrv_comparefh(const nfsrvfh_t *fh1, const nfsrvfh_t *fh2)
413 {
414
415 if (NFSRVFH_SIZE(fh1) != NFSRVFH_SIZE(fh2)) {
416 return NFSRVFH_SIZE(fh2) - NFSRVFH_SIZE(fh1);
417 }
418 return memcmp(NFSRVFH_DATA(fh1), NFSRVFH_DATA(fh2), NFSRVFH_SIZE(fh1));
419 }
420
421 void
422 nfsrv_copyfh(nfsrvfh_t *fh1, const nfsrvfh_t *fh2)
423 {
424 size_t size;
425
426 fh1->nsfh_size = size = NFSRVFH_SIZE(fh2);
427 memcpy(NFSRVFH_DATA(fh1), NFSRVFH_DATA(fh2), size);
428 }
429