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[PATCH] knfsd: Fix up some bit-rot in exp_export
[linux.git] / fs / nfsd / nfsfh.c
CommitLineData
1da177e4
LT		 1/*
2 * linux/fs/nfsd/nfsfh.c
3 *
4 * NFS server file handle treatment.
5 *
6 * Copyright (C) 1995, 1996 Olaf Kirch <[email protected]>
7 * Portions Copyright (C) 1999 G. Allen Morris III <[email protected]>
8 * Extensive rewrite by Neil Brown <[email protected]> Southern-Spring 1999
9 * ... and again Southern-Winter 2001 to support export_operations
10 */
11
12#include <linux/sched.h>
13#include <linux/slab.h>
14#include <linux/smp_lock.h>
15#include <linux/fs.h>
16#include <linux/unistd.h>
17#include <linux/string.h>
18#include <linux/stat.h>
19#include <linux/dcache.h>
20#include <linux/mount.h>
21#include <asm/pgtable.h>
22
23#include <linux/sunrpc/svc.h>
24#include <linux/nfsd/nfsd.h>
25
26#define NFSDDBG_FACILITY NFSDDBG_FH
27#define NFSD_PARANOIA 1
28/* #define NFSD_DEBUG_VERBOSE 1 */
29
30
31static int nfsd_nr_verified;
32static int nfsd_nr_put;
33
34extern struct export_operations export_op_default;
35
36#define CALL(ops,fun) ((ops->fun)?(ops->fun):export_op_default.fun)
37
38/*
39 * our acceptability function.
40 * if NOSUBTREECHECK, accept anything
41 * if not, require that we can walk up to exp->ex_dentry
42 * doing some checks on the 'x' bits
43 */
44static int nfsd_acceptable(void *expv, struct dentry *dentry)
45{
46 struct svc_export *exp = expv;
47 int rv;
48 struct dentry *tdentry;
49 struct dentry *parent;
50
51 if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
52 return 1;
53
54 tdentry = dget(dentry);
55 while (tdentry != exp->ex_dentry && ! IS_ROOT(tdentry)) {
56 /* make sure parents give x permission to user */
57 int err;
58 parent = dget_parent(tdentry);
59 err = permission(parent->d_inode, MAY_EXEC, NULL);
60 if (err < 0) {
61 dput(parent);
62 break;
63 }
64 dput(tdentry);
65 tdentry = parent;
66 }
67 if (tdentry != exp->ex_dentry)
68 dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
69 rv = (tdentry == exp->ex_dentry);
70 dput(tdentry);
71 return rv;
72}
73
74/* Type check. The correct error return for type mismatches does not seem to be
75 * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
76 * comment in the NFSv3 spec says this is incorrect (implementation notes for
77 * the write call).
78 */
83b11340 79static inline __be32
1da177e4
LT		 80nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
81{
82 /* Type can be negative when creating hardlinks - not to a dir */
83 if (type > 0 && (mode & S_IFMT) != type) {
84 if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
85 return nfserr_symlink;
86 else if (type == S_IFDIR)
87 return nfserr_notdir;
88 else if ((mode & S_IFMT) == S_IFDIR)
89 return nfserr_isdir;
90 else
91 return nfserr_inval;
92 }
93 if (type < 0 && (mode & S_IFMT) == -type) {
94 if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
95 return nfserr_symlink;
96 else if (type == -S_IFDIR)
97 return nfserr_isdir;
98 else
99 return nfserr_notdir;
100 }
101 return 0;
102}
103
104/*
105 * Perform sanity checks on the dentry in a client's file handle.
106 *
107 * Note that the file handle dentry may need to be freed even after
108 * an error return.
109 *
110 * This is only called at the start of an nfsproc call, so fhp points to
111 * a svc_fh which is all 0 except for the over-the-wire file handle.
112 */
83b11340 113__be32
1da177e4
LT		 114fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
115{
116 struct knfsd_fh *fh = &fhp->fh_handle;
117 struct svc_export *exp = NULL;
118 struct dentry *dentry;
83b11340 119 __be32 error = 0;
1da177e4
LT		 120
121 dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
122
123 /* keep this filehandle for possible reference when encoding attributes */
124 rqstp->rq_reffh = fh;
125
126 if (!fhp->fh_dentry) {
127 __u32 *datap=NULL;
128 __u32 tfh[3]; /* filehandle fragment for oldstyle filehandles */
129 int fileid_type;
130 int data_left = fh->fh_size/4;
131
132 error = nfserr_stale;
133 if (rqstp->rq_client == NULL)
134 goto out;
135 if (rqstp->rq_vers > 2)
136 error = nfserr_badhandle;
137 if (rqstp->rq_vers == 4 && fh->fh_size == 0)
138 return nfserr_nofilehandle;
139
140 if (fh->fh_version == 1) {
141 int len;
142 datap = fh->fh_auth;
143 if (--data_left<0) goto out;
144 switch (fh->fh_auth_type) {
145 case 0: break;
146 default: goto out;
147 }
148 len = key_len(fh->fh_fsid_type) / 4;
149 if (len == 0) goto out;
150 if (fh->fh_fsid_type == 2) {
151 /* deprecated, convert to type 3 */
152 len = 3;
153 fh->fh_fsid_type = 3;
154 fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
155 fh->fh_fsid[1] = fh->fh_fsid[2];
156 }
157 if ((data_left -= len)<0) goto out;
158 exp = exp_find(rqstp->rq_client, fh->fh_fsid_type, datap, &rqstp->rq_chandle);
159 datap += len;
160 } else {
161 dev_t xdev;
162 ino_t xino;
163 if (fh->fh_size != NFS_FHSIZE)
164 goto out;
165 /* assume old filehandle format */
166 xdev = old_decode_dev(fh->ofh_xdev);
167 xino = u32_to_ino_t(fh->ofh_xino);
168 mk_fsid_v0(tfh, xdev, xino);
169 exp = exp_find(rqstp->rq_client, 0, tfh, &rqstp->rq_chandle);
170 }
171
e0bb89ef
BF		 172 if (IS_ERR(exp) && (PTR_ERR(exp) == -EAGAIN
173 || PTR_ERR(exp) == -ETIMEDOUT)) {
174 error = nfserrno(PTR_ERR(exp));
1da177e4 175 goto out;
e0bb89ef 176 }
1da177e4
LT		 177
178 error = nfserr_stale;
179 if (!exp || IS_ERR(exp))
180 goto out;
181
182 /* Check if the request originated from a secure port. */
183 error = nfserr_perm;
184 if (!rqstp->rq_secure && EX_SECURE(exp)) {
185 printk(KERN_WARNING
186 "nfsd: request from insecure port (%u.%u.%u.%u:%d)!\n",
187 NIPQUAD(rqstp->rq_addr.sin_addr.s_addr),
188 ntohs(rqstp->rq_addr.sin_port));
189 goto out;
190 }
191
d1bbf14f
N		 192 /* Set user creds for this exportpoint */
193 error = nfserrno(nfsd_setuser(rqstp, exp));
194 if (error)
195 goto out;
196
1da177e4
LT		 197 /*
198 * Look up the dentry using the NFS file handle.
199 */
200 error = nfserr_stale;
201 if (rqstp->rq_vers > 2)
202 error = nfserr_badhandle;
203
204 if (fh->fh_version != 1) {
205 tfh[0] = fh->ofh_ino;
206 tfh[1] = fh->ofh_generation;
207 tfh[2] = fh->ofh_dirino;
208 datap = tfh;
209 data_left = 3;
210 if (fh->ofh_dirino == 0)
211 fileid_type = 1;
212 else
213 fileid_type = 2;
214 } else
215 fileid_type = fh->fh_fileid_type;
216
217 if (fileid_type == 0)
218 dentry = dget(exp->ex_dentry);
219 else {
220 struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
221 dentry = CALL(nop,decode_fh)(exp->ex_mnt->mnt_sb,
222 datap, data_left,
223 fileid_type,
224 nfsd_acceptable, exp);
225 }
226 if (dentry == NULL)
227 goto out;
228 if (IS_ERR(dentry)) {
229 if (PTR_ERR(dentry) != -EINVAL)
230 error = nfserrno(PTR_ERR(dentry));
231 goto out;
232 }
233#ifdef NFSD_PARANOIA
234 if (S_ISDIR(dentry->d_inode->i_mode) &&
235 (dentry->d_flags & DCACHE_DISCONNECTED)) {
236 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
237 dentry->d_parent->d_name.name, dentry->d_name.name);
238 }
239#endif
240
241 fhp->fh_dentry = dentry;
242 fhp->fh_export = exp;
243 nfsd_nr_verified++;
244 } else {
245 /* just rechecking permissions
246 * (e.g. nfsproc_create calls fh_verify, then nfsd_create does as well)
247 */
248 dprintk("nfsd: fh_verify - just checking\n");
249 dentry = fhp->fh_dentry;
250 exp = fhp->fh_export;
d1bbf14f
N		 251 /* Set user creds for this exportpoint; necessary even
252 * in the "just checking" case because this may be a
253 * filehandle that was created by fh_compose, and that
254 * is about to be used in another nfsv4 compound
255 * operation */
256 error = nfserrno(nfsd_setuser(rqstp, exp));
257 if (error)
258 goto out;
1da177e4
LT		 259 }
260 cache_get(&exp->h);
261
7fc90ec9 262
1da177e4
LT		 263 error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
264 if (error)
265 goto out;
266
267 /* Finally, check access permissions. */
268 error = nfsd_permission(exp, dentry, access);
269
270#ifdef NFSD_PARANOIA_EXTREME
271 if (error) {
272 printk("fh_verify: %s/%s permission failure, acc=%x, error=%d\n",
273 dentry->d_parent->d_name.name, dentry->d_name.name, access, (error >> 24));
274 }
275#endif
276out:
277 if (exp && !IS_ERR(exp))
278 exp_put(exp);
279 if (error == nfserr_stale)
280 nfsdstats.fh_stale++;
281 return error;
282}
283
284
285/*
286 * Compose a file handle for an NFS reply.
287 *
288 * Note that when first composed, the dentry may not yet have
289 * an inode. In this case a call to fh_update should be made
290 * before the fh goes out on the wire ...
291 */
292static inline int _fh_update(struct dentry *dentry, struct svc_export *exp,
293 __u32 *datap, int *maxsize)
294{
295 struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
296
297 if (dentry == exp->ex_dentry) {
298 *maxsize = 0;
299 return 0;
300 }
301
302 return CALL(nop,encode_fh)(dentry, datap, maxsize,
303 !(exp->ex_flags&NFSEXP_NOSUBTREECHECK));
304}
305
306/*
307 * for composing old style file handles
308 */
309static inline void _fh_update_old(struct dentry *dentry,
310 struct svc_export *exp,
311 struct knfsd_fh *fh)
312{
313 fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
314 fh->ofh_generation = dentry->d_inode->i_generation;
315 if (S_ISDIR(dentry->d_inode->i_mode) ||
316 (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
317 fh->ofh_dirino = 0;
318}
319
83b11340 320__be32
1da177e4
LT		 321fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry, struct svc_fh *ref_fh)
322{
323 /* ref_fh is a reference file handle.
7e405364
N		 324 * if it is non-null and for the same filesystem, then we should compose
325 * a filehandle which is of the same version, where possible.
1da177e4
LT		 326 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
327 * Then create a 32byte filehandle using nfs_fhbase_old
328 *
329 */
330
331 u8 ref_fh_version = 0;
332 u8 ref_fh_fsid_type = 0;
333 struct inode * inode = dentry->d_inode;
334 struct dentry *parent = dentry->d_parent;
335 __u32 *datap;
336 dev_t ex_dev = exp->ex_dentry->d_inode->i_sb->s_dev;
337
338 dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
339 MAJOR(ex_dev), MINOR(ex_dev),
340 (long) exp->ex_dentry->d_inode->i_ino,
341 parent->d_name.name, dentry->d_name.name,
342 (inode ? inode->i_ino : 0));
343
7e405364 344 if (ref_fh && ref_fh->fh_export == exp) {
1da177e4
LT		 345 ref_fh_version = ref_fh->fh_handle.fh_version;
346 if (ref_fh_version == 0xca)
347 ref_fh_fsid_type = 0;
348 else
349 ref_fh_fsid_type = ref_fh->fh_handle.fh_fsid_type;
350 if (ref_fh_fsid_type > 3)
351 ref_fh_fsid_type = 0;
352
353 /* make sure ref_fh type works for given export */
354 if (ref_fh_fsid_type == 1 &&
355 !(exp->ex_flags & NFSEXP_FSID)) {
356 /* if we don't have an fsid, we cannot provide one... */
357 ref_fh_fsid_type = 0;
358 }
359 } else if (exp->ex_flags & NFSEXP_FSID)
360 ref_fh_fsid_type = 1;
361
362 if (!old_valid_dev(ex_dev) && ref_fh_fsid_type == 0) {
363 /* for newer device numbers, we must use a newer fsid format */
364 ref_fh_version = 1;
365 ref_fh_fsid_type = 3;
366 }
367 if (old_valid_dev(ex_dev) &&
368 (ref_fh_fsid_type == 2 || ref_fh_fsid_type == 3))
369 /* must use type1 for smaller device numbers */
370 ref_fh_fsid_type = 0;
371
372 if (ref_fh == fhp)
373 fh_put(ref_fh);
374
375 if (fhp->fh_locked || fhp->fh_dentry) {
376 printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
377 parent->d_name.name, dentry->d_name.name);
378 }
379 if (fhp->fh_maxsize < NFS_FHSIZE)
380 printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
381 fhp->fh_maxsize, parent->d_name.name, dentry->d_name.name);
382
383 fhp->fh_dentry = dget(dentry); /* our internal copy */
384 fhp->fh_export = exp;
385 cache_get(&exp->h);
386
387 if (ref_fh_version == 0xca) {
388 /* old style filehandle please */
389 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
390 fhp->fh_handle.fh_size = NFS_FHSIZE;
391 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
392 fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev);
393 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
394 fhp->fh_handle.ofh_xino = ino_t_to_u32(exp->ex_dentry->d_inode->i_ino);
395 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
396 if (inode)
397 _fh_update_old(dentry, exp, &fhp->fh_handle);
398 } else {
399 int len;
400 fhp->fh_handle.fh_version = 1;
401 fhp->fh_handle.fh_auth_type = 0;
402 datap = fhp->fh_handle.fh_auth+0;
403 fhp->fh_handle.fh_fsid_type = ref_fh_fsid_type;
404 switch (ref_fh_fsid_type) {
405 case 0:
406 /*
407 * fsid_type 0:
408 * 2byte major, 2byte minor, 4byte inode
409 */
410 mk_fsid_v0(datap, ex_dev,
411 exp->ex_dentry->d_inode->i_ino);
412 break;
413 case 1:
414 /* fsid_type 1 == 4 bytes filesystem id */
415 mk_fsid_v1(datap, exp->ex_fsid);
416 break;
417 case 2:
418 /*
419 * fsid_type 2:
420 * 4byte major, 4byte minor, 4byte inode
421 */
422 mk_fsid_v2(datap, ex_dev,
423 exp->ex_dentry->d_inode->i_ino);
424 break;
425 case 3:
426 /*
427 * fsid_type 3:
428 * 4byte devicenumber, 4byte inode
429 */
430 mk_fsid_v3(datap, ex_dev,
431 exp->ex_dentry->d_inode->i_ino);
432 break;
433 }
434 len = key_len(ref_fh_fsid_type);
435 datap += len/4;
436 fhp->fh_handle.fh_size = 4 + len;
437
438 if (inode) {
439 int size = (fhp->fh_maxsize-len-4)/4;
440 fhp->fh_handle.fh_fileid_type =
441 _fh_update(dentry, exp, datap, &size);
442 fhp->fh_handle.fh_size += size*4;
443 }
444 if (fhp->fh_handle.fh_fileid_type == 255)
445 return nfserr_opnotsupp;
446 }
447
448 nfsd_nr_verified++;
449 return 0;
450}
451
452/*
453 * Update file handle information after changing a dentry.
454 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
455 */
83b11340 456__be32
1da177e4
LT		 457fh_update(struct svc_fh *fhp)
458{
459 struct dentry *dentry;
460 __u32 *datap;
461
462 if (!fhp->fh_dentry)
463 goto out_bad;
464
465 dentry = fhp->fh_dentry;
466 if (!dentry->d_inode)
467 goto out_negative;
468 if (fhp->fh_handle.fh_version != 1) {
469 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
470 } else {
471 int size;
472 if (fhp->fh_handle.fh_fileid_type != 0)
4c9608b2 473 goto out;
1da177e4
LT		 474 datap = fhp->fh_handle.fh_auth+
475 fhp->fh_handle.fh_size/4 -1;
476 size = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
477 fhp->fh_handle.fh_fileid_type =
478 _fh_update(dentry, fhp->fh_export, datap, &size);
479 fhp->fh_handle.fh_size += size*4;
480 if (fhp->fh_handle.fh_fileid_type == 255)
481 return nfserr_opnotsupp;
482 }
483out:
484 return 0;
485
486out_bad:
487 printk(KERN_ERR "fh_update: fh not verified!\n");
488 goto out;
489out_negative:
490 printk(KERN_ERR "fh_update: %s/%s still negative!\n",
491 dentry->d_parent->d_name.name, dentry->d_name.name);
492 goto out;
1da177e4
LT		 493}
494
495/*
496 * Release a file handle.
497 */
498void
499fh_put(struct svc_fh *fhp)
500{
501 struct dentry * dentry = fhp->fh_dentry;
502 struct svc_export * exp = fhp->fh_export;
503 if (dentry) {
504 fh_unlock(fhp);
505 fhp->fh_dentry = NULL;
506 dput(dentry);
507#ifdef CONFIG_NFSD_V3
508 fhp->fh_pre_saved = 0;
509 fhp->fh_post_saved = 0;
510#endif
511 nfsd_nr_put++;
512 }
513 if (exp) {
baab935f 514 cache_put(&exp->h, &svc_export_cache);
1da177e4
LT		 515 fhp->fh_export = NULL;
516 }
517 return;
518}
519
520/*
521 * Shorthand for dprintk()'s
522 */
523char * SVCFH_fmt(struct svc_fh *fhp)
524{
525 struct knfsd_fh *fh = &fhp->fh_handle;
526
527 static char buf[80];
528 sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
529 fh->fh_size,
530 fh->fh_base.fh_pad[0],
531 fh->fh_base.fh_pad[1],
532 fh->fh_base.fh_pad[2],
533 fh->fh_base.fh_pad[3],
534 fh->fh_base.fh_pad[4],
535 fh->fh_base.fh_pad[5]);
536 return buf;
537}
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