projects / deliverable / linux.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[deliverable/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 <okir@monad.swb.de>
7 * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
8 * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> 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 */
79static inline int
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 */
113u32
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;
119 u32 error = 0;
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
172 error = nfserr_dropit;
173 if (IS_ERR(exp) && PTR_ERR(exp) == -EAGAIN)
174 goto out;
175
176 error = nfserr_stale;
177 if (!exp || IS_ERR(exp))
178 goto out;
179
180 /* Check if the request originated from a secure port. */
181 error = nfserr_perm;
182 if (!rqstp->rq_secure && EX_SECURE(exp)) {
183 printk(KERN_WARNING
184 "nfsd: request from insecure port (%u.%u.%u.%u:%d)!\n",
185 NIPQUAD(rqstp->rq_addr.sin_addr.s_addr),
186 ntohs(rqstp->rq_addr.sin_port));
187 goto out;
188 }
189
1da177e4
LT		 190 /*
191 * Look up the dentry using the NFS file handle.
192 */
193 error = nfserr_stale;
194 if (rqstp->rq_vers > 2)
195 error = nfserr_badhandle;
196
197 if (fh->fh_version != 1) {
198 tfh[0] = fh->ofh_ino;
199 tfh[1] = fh->ofh_generation;
200 tfh[2] = fh->ofh_dirino;
201 datap = tfh;
202 data_left = 3;
203 if (fh->ofh_dirino == 0)
204 fileid_type = 1;
205 else
206 fileid_type = 2;
207 } else
208 fileid_type = fh->fh_fileid_type;
209
210 if (fileid_type == 0)
211 dentry = dget(exp->ex_dentry);
212 else {
213 struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
214 dentry = CALL(nop,decode_fh)(exp->ex_mnt->mnt_sb,
215 datap, data_left,
216 fileid_type,
217 nfsd_acceptable, exp);
218 }
219 if (dentry == NULL)
220 goto out;
221 if (IS_ERR(dentry)) {
222 if (PTR_ERR(dentry) != -EINVAL)
223 error = nfserrno(PTR_ERR(dentry));
224 goto out;
225 }
226#ifdef NFSD_PARANOIA
227 if (S_ISDIR(dentry->d_inode->i_mode) &&
228 (dentry->d_flags & DCACHE_DISCONNECTED)) {
229 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
230 dentry->d_parent->d_name.name, dentry->d_name.name);
231 }
232#endif
233
234 fhp->fh_dentry = dentry;
235 fhp->fh_export = exp;
236 nfsd_nr_verified++;
237 } else {
238 /* just rechecking permissions
239 * (e.g. nfsproc_create calls fh_verify, then nfsd_create does as well)
240 */
241 dprintk("nfsd: fh_verify - just checking\n");
242 dentry = fhp->fh_dentry;
243 exp = fhp->fh_export;
244 }
245 cache_get(&exp->h);
246
7fc90ec9
BF		 247 /* Set user creds for this exportpoint; necessary even in the "just
248 * checking" case because this may be a filehandle that was created by
249 * fh_compose, and that is about to be used in another nfsv4 compound
250 * operation */
251 error = nfserrno(nfsd_setuser(rqstp, exp));
252 if (error)
253 goto out;
254
1da177e4
LT		 255 error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
256 if (error)
257 goto out;
258
259 /* Finally, check access permissions. */
260 error = nfsd_permission(exp, dentry, access);
261
262#ifdef NFSD_PARANOIA_EXTREME
263 if (error) {
264 printk("fh_verify: %s/%s permission failure, acc=%x, error=%d\n",
265 dentry->d_parent->d_name.name, dentry->d_name.name, access, (error >> 24));
266 }
267#endif
268out:
269 if (exp && !IS_ERR(exp))
270 exp_put(exp);
271 if (error == nfserr_stale)
272 nfsdstats.fh_stale++;
273 return error;
274}
275
276
277/*
278 * Compose a file handle for an NFS reply.
279 *
280 * Note that when first composed, the dentry may not yet have
281 * an inode. In this case a call to fh_update should be made
282 * before the fh goes out on the wire ...
283 */
284static inline int _fh_update(struct dentry *dentry, struct svc_export *exp,
285 __u32 *datap, int *maxsize)
286{
287 struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
288
289 if (dentry == exp->ex_dentry) {
290 *maxsize = 0;
291 return 0;
292 }
293
294 return CALL(nop,encode_fh)(dentry, datap, maxsize,
295 !(exp->ex_flags&NFSEXP_NOSUBTREECHECK));
296}
297
298/*
299 * for composing old style file handles
300 */
301static inline void _fh_update_old(struct dentry *dentry,
302 struct svc_export *exp,
303 struct knfsd_fh *fh)
304{
305 fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
306 fh->ofh_generation = dentry->d_inode->i_generation;
307 if (S_ISDIR(dentry->d_inode->i_mode) ||
308 (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
309 fh->ofh_dirino = 0;
310}
311
312int
313fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry, struct svc_fh *ref_fh)
314{
315 /* ref_fh is a reference file handle.
7e405364
N		 316 * if it is non-null and for the same filesystem, then we should compose
317 * a filehandle which is of the same version, where possible.
1da177e4
LT		 318 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
319 * Then create a 32byte filehandle using nfs_fhbase_old
320 *
321 */
322
323 u8 ref_fh_version = 0;
324 u8 ref_fh_fsid_type = 0;
325 struct inode * inode = dentry->d_inode;
326 struct dentry *parent = dentry->d_parent;
327 __u32 *datap;
328 dev_t ex_dev = exp->ex_dentry->d_inode->i_sb->s_dev;
329
330 dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
331 MAJOR(ex_dev), MINOR(ex_dev),
332 (long) exp->ex_dentry->d_inode->i_ino,
333 parent->d_name.name, dentry->d_name.name,
334 (inode ? inode->i_ino : 0));
335
7e405364 336 if (ref_fh && ref_fh->fh_export == exp) {
1da177e4
LT		 337 ref_fh_version = ref_fh->fh_handle.fh_version;
338 if (ref_fh_version == 0xca)
339 ref_fh_fsid_type = 0;
340 else
341 ref_fh_fsid_type = ref_fh->fh_handle.fh_fsid_type;
342 if (ref_fh_fsid_type > 3)
343 ref_fh_fsid_type = 0;
344
345 /* make sure ref_fh type works for given export */
346 if (ref_fh_fsid_type == 1 &&
347 !(exp->ex_flags & NFSEXP_FSID)) {
348 /* if we don't have an fsid, we cannot provide one... */
349 ref_fh_fsid_type = 0;
350 }
351 } else if (exp->ex_flags & NFSEXP_FSID)
352 ref_fh_fsid_type = 1;
353
354 if (!old_valid_dev(ex_dev) && ref_fh_fsid_type == 0) {
355 /* for newer device numbers, we must use a newer fsid format */
356 ref_fh_version = 1;
357 ref_fh_fsid_type = 3;
358 }
359 if (old_valid_dev(ex_dev) &&
360 (ref_fh_fsid_type == 2 || ref_fh_fsid_type == 3))
361 /* must use type1 for smaller device numbers */
362 ref_fh_fsid_type = 0;
363
364 if (ref_fh == fhp)
365 fh_put(ref_fh);
366
367 if (fhp->fh_locked || fhp->fh_dentry) {
368 printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
369 parent->d_name.name, dentry->d_name.name);
370 }
371 if (fhp->fh_maxsize < NFS_FHSIZE)
372 printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
373 fhp->fh_maxsize, parent->d_name.name, dentry->d_name.name);
374
375 fhp->fh_dentry = dget(dentry); /* our internal copy */
376 fhp->fh_export = exp;
377 cache_get(&exp->h);
378
379 if (ref_fh_version == 0xca) {
380 /* old style filehandle please */
381 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
382 fhp->fh_handle.fh_size = NFS_FHSIZE;
383 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
384 fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev);
385 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
386 fhp->fh_handle.ofh_xino = ino_t_to_u32(exp->ex_dentry->d_inode->i_ino);
387 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
388 if (inode)
389 _fh_update_old(dentry, exp, &fhp->fh_handle);
390 } else {
391 int len;
392 fhp->fh_handle.fh_version = 1;
393 fhp->fh_handle.fh_auth_type = 0;
394 datap = fhp->fh_handle.fh_auth+0;
395 fhp->fh_handle.fh_fsid_type = ref_fh_fsid_type;
396 switch (ref_fh_fsid_type) {
397 case 0:
398 /*
399 * fsid_type 0:
400 * 2byte major, 2byte minor, 4byte inode
401 */
402 mk_fsid_v0(datap, ex_dev,
403 exp->ex_dentry->d_inode->i_ino);
404 break;
405 case 1:
406 /* fsid_type 1 == 4 bytes filesystem id */
407 mk_fsid_v1(datap, exp->ex_fsid);
408 break;
409 case 2:
410 /*
411 * fsid_type 2:
412 * 4byte major, 4byte minor, 4byte inode
413 */
414 mk_fsid_v2(datap, ex_dev,
415 exp->ex_dentry->d_inode->i_ino);
416 break;
417 case 3:
418 /*
419 * fsid_type 3:
420 * 4byte devicenumber, 4byte inode
421 */
422 mk_fsid_v3(datap, ex_dev,
423 exp->ex_dentry->d_inode->i_ino);
424 break;
425 }
426 len = key_len(ref_fh_fsid_type);
427 datap += len/4;
428 fhp->fh_handle.fh_size = 4 + len;
429
430 if (inode) {
431 int size = (fhp->fh_maxsize-len-4)/4;
432 fhp->fh_handle.fh_fileid_type =
433 _fh_update(dentry, exp, datap, &size);
434 fhp->fh_handle.fh_size += size*4;
435 }
436 if (fhp->fh_handle.fh_fileid_type == 255)
437 return nfserr_opnotsupp;
438 }
439
440 nfsd_nr_verified++;
441 return 0;
442}
443
444/*
445 * Update file handle information after changing a dentry.
446 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
447 */
448int
449fh_update(struct svc_fh *fhp)
450{
451 struct dentry *dentry;
452 __u32 *datap;
453
454 if (!fhp->fh_dentry)
455 goto out_bad;
456
457 dentry = fhp->fh_dentry;
458 if (!dentry->d_inode)
459 goto out_negative;
460 if (fhp->fh_handle.fh_version != 1) {
461 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
462 } else {
463 int size;
464 if (fhp->fh_handle.fh_fileid_type != 0)
4c9608b2 465 goto out;
1da177e4
LT		 466 datap = fhp->fh_handle.fh_auth+
467 fhp->fh_handle.fh_size/4 -1;
468 size = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
469 fhp->fh_handle.fh_fileid_type =
470 _fh_update(dentry, fhp->fh_export, datap, &size);
471 fhp->fh_handle.fh_size += size*4;
472 if (fhp->fh_handle.fh_fileid_type == 255)
473 return nfserr_opnotsupp;
474 }
475out:
476 return 0;
477
478out_bad:
479 printk(KERN_ERR "fh_update: fh not verified!\n");
480 goto out;
481out_negative:
482 printk(KERN_ERR "fh_update: %s/%s still negative!\n",
483 dentry->d_parent->d_name.name, dentry->d_name.name);
484 goto out;
1da177e4
LT		 485}
486
487/*
488 * Release a file handle.
489 */
490void
491fh_put(struct svc_fh *fhp)
492{
493 struct dentry * dentry = fhp->fh_dentry;
494 struct svc_export * exp = fhp->fh_export;
495 if (dentry) {
496 fh_unlock(fhp);
497 fhp->fh_dentry = NULL;
498 dput(dentry);
499#ifdef CONFIG_NFSD_V3
500 fhp->fh_pre_saved = 0;
501 fhp->fh_post_saved = 0;
502#endif
503 nfsd_nr_put++;
504 }
505 if (exp) {
baab935f 506 cache_put(&exp->h, &svc_export_cache);
1da177e4
LT		 507 fhp->fh_export = NULL;
508 }
509 return;
510}
511
512/*
513 * Shorthand for dprintk()'s
514 */
515char * SVCFH_fmt(struct svc_fh *fhp)
516{
517 struct knfsd_fh *fh = &fhp->fh_handle;
518
519 static char buf[80];
520 sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
521 fh->fh_size,
522 fh->fh_base.fh_pad[0],
523 fh->fh_base.fh_pad[1],
524 fh->fh_base.fh_pad[2],
525 fh->fh_base.fh_pad[3],
526 fh->fh_base.fh_pad[4],
527 fh->fh_base.fh_pad[5]);
528 return buf;
529}
Linux kernel - Deliverables
This page took 0.149886 seconds and 5 git commands to generate.