2 * linux/fs/nfsd/nfsfh.c
4 * NFS server file handle treatment.
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
12 #include <linux/sched.h>
13 #include <linux/slab.h>
14 #include <linux/smp_lock.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>
23 #include <linux/sunrpc/svc.h>
24 #include <linux/nfsd/nfsd.h>
26 #define NFSDDBG_FACILITY NFSDDBG_FH
27 #define NFSD_PARANOIA 1
28 /* #define NFSD_DEBUG_VERBOSE 1 */
31 static int nfsd_nr_verified;
32 static int nfsd_nr_put;
34 extern struct export_operations export_op_default;
36 #define CALL(ops,fun) ((ops->fun)?(ops->fun):export_op_default.fun)
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
44 static int nfsd_acceptable(void *expv, struct dentry *dentry)
46 struct svc_export *exp = expv;
48 struct dentry *tdentry;
49 struct dentry *parent;
51 if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
54 tdentry = dget(dentry);
55 while (tdentry != exp->ex_dentry && ! IS_ROOT(tdentry)) {
56 /* make sure parents give x permission to user */
58 parent = dget_parent(tdentry);
59 err = permission(parent->d_inode, MAY_EXEC, NULL);
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);
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
80 nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
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)
88 else if ((mode & S_IFMT) == S_IFDIR)
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)
105 * Perform sanity checks on the dentry in a client's file handle.
107 * Note that the file handle dentry may need to be freed even after
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.
114 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
116 struct knfsd_fh *fh = &fhp->fh_handle;
117 struct svc_export *exp = NULL;
118 struct dentry *dentry;
121 dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
123 /* keep this filehandle for possible reference when encoding attributes */
124 rqstp->rq_reffh = fh;
126 if (!fhp->fh_dentry) {
128 __u32 tfh[3]; /* filehandle fragment for oldstyle filehandles */
130 int data_left = fh->fh_size/4;
132 error = nfserr_stale;
133 if (rqstp->rq_client == NULL)
135 if (rqstp->rq_vers > 2)
136 error = nfserr_badhandle;
137 if (rqstp->rq_vers == 4 && fh->fh_size == 0)
138 return nfserr_nofilehandle;
140 if (fh->fh_version == 1) {
143 if (--data_left<0) goto out;
144 switch (fh->fh_auth_type) {
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 */
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];
157 if ((data_left -= len)<0) goto out;
158 exp = exp_find(rqstp->rq_client, fh->fh_fsid_type, datap, &rqstp->rq_chandle);
163 if (fh->fh_size != NFS_FHSIZE)
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);
172 error = nfserr_dropit;
173 if (IS_ERR(exp) && PTR_ERR(exp) == -EAGAIN)
176 error = nfserr_stale;
177 if (!exp || IS_ERR(exp))
180 /* Check if the request originated from a secure port. */
182 if (!rqstp->rq_secure && EX_SECURE(exp)) {
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));
190 /* Set user creds for this exportpoint */
191 error = nfserrno(nfsd_setuser(rqstp, exp));
196 * Look up the dentry using the NFS file handle.
198 error = nfserr_stale;
199 if (rqstp->rq_vers > 2)
200 error = nfserr_badhandle;
202 if (fh->fh_version != 1) {
203 tfh[0] = fh->ofh_ino;
204 tfh[1] = fh->ofh_generation;
205 tfh[2] = fh->ofh_dirino;
208 if (fh->ofh_dirino == 0)
213 fileid_type = fh->fh_fileid_type;
215 if (fileid_type == 0)
216 dentry = dget(exp->ex_dentry);
218 struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
219 dentry = CALL(nop,decode_fh)(exp->ex_mnt->mnt_sb,
222 nfsd_acceptable, exp);
226 if (IS_ERR(dentry)) {
227 if (PTR_ERR(dentry) != -EINVAL)
228 error = nfserrno(PTR_ERR(dentry));
232 if (S_ISDIR(dentry->d_inode->i_mode) &&
233 (dentry->d_flags & DCACHE_DISCONNECTED)) {
234 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
235 dentry->d_parent->d_name.name, dentry->d_name.name);
239 fhp->fh_dentry = dentry;
240 fhp->fh_export = exp;
243 /* just rechecking permissions
244 * (e.g. nfsproc_create calls fh_verify, then nfsd_create does as well)
246 dprintk("nfsd: fh_verify - just checking\n");
247 dentry = fhp->fh_dentry;
248 exp = fhp->fh_export;
249 /* Set user creds for this exportpoint; necessary even
250 * in the "just checking" case because this may be a
251 * filehandle that was created by fh_compose, and that
252 * is about to be used in another nfsv4 compound
254 error = nfserrno(nfsd_setuser(rqstp, exp));
261 error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
265 /* Finally, check access permissions. */
266 error = nfsd_permission(exp, dentry, access);
268 #ifdef NFSD_PARANOIA_EXTREME
270 printk("fh_verify: %s/%s permission failure, acc=%x, error=%d\n",
271 dentry->d_parent->d_name.name, dentry->d_name.name, access, (error >> 24));
275 if (exp && !IS_ERR(exp))
277 if (error == nfserr_stale)
278 nfsdstats.fh_stale++;
284 * Compose a file handle for an NFS reply.
286 * Note that when first composed, the dentry may not yet have
287 * an inode. In this case a call to fh_update should be made
288 * before the fh goes out on the wire ...
290 static inline int _fh_update(struct dentry *dentry, struct svc_export *exp,
291 __u32 *datap, int *maxsize)
293 struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op;
295 if (dentry == exp->ex_dentry) {
300 return CALL(nop,encode_fh)(dentry, datap, maxsize,
301 !(exp->ex_flags&NFSEXP_NOSUBTREECHECK));
305 * for composing old style file handles
307 static inline void _fh_update_old(struct dentry *dentry,
308 struct svc_export *exp,
311 fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
312 fh->ofh_generation = dentry->d_inode->i_generation;
313 if (S_ISDIR(dentry->d_inode->i_mode) ||
314 (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
319 fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry, struct svc_fh *ref_fh)
321 /* ref_fh is a reference file handle.
322 * if it is non-null and for the same filesystem, then we should compose
323 * a filehandle which is of the same version, where possible.
324 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
325 * Then create a 32byte filehandle using nfs_fhbase_old
329 u8 ref_fh_version = 0;
330 u8 ref_fh_fsid_type = 0;
331 struct inode * inode = dentry->d_inode;
332 struct dentry *parent = dentry->d_parent;
334 dev_t ex_dev = exp->ex_dentry->d_inode->i_sb->s_dev;
336 dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
337 MAJOR(ex_dev), MINOR(ex_dev),
338 (long) exp->ex_dentry->d_inode->i_ino,
339 parent->d_name.name, dentry->d_name.name,
340 (inode ? inode->i_ino : 0));
342 if (ref_fh && ref_fh->fh_export == exp) {
343 ref_fh_version = ref_fh->fh_handle.fh_version;
344 if (ref_fh_version == 0xca)
345 ref_fh_fsid_type = 0;
347 ref_fh_fsid_type = ref_fh->fh_handle.fh_fsid_type;
348 if (ref_fh_fsid_type > 3)
349 ref_fh_fsid_type = 0;
351 /* make sure ref_fh type works for given export */
352 if (ref_fh_fsid_type == 1 &&
353 !(exp->ex_flags & NFSEXP_FSID)) {
354 /* if we don't have an fsid, we cannot provide one... */
355 ref_fh_fsid_type = 0;
357 } else if (exp->ex_flags & NFSEXP_FSID)
358 ref_fh_fsid_type = 1;
360 if (!old_valid_dev(ex_dev) && ref_fh_fsid_type == 0) {
361 /* for newer device numbers, we must use a newer fsid format */
363 ref_fh_fsid_type = 3;
365 if (old_valid_dev(ex_dev) &&
366 (ref_fh_fsid_type == 2 || ref_fh_fsid_type == 3))
367 /* must use type1 for smaller device numbers */
368 ref_fh_fsid_type = 0;
373 if (fhp->fh_locked || fhp->fh_dentry) {
374 printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
375 parent->d_name.name, dentry->d_name.name);
377 if (fhp->fh_maxsize < NFS_FHSIZE)
378 printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
379 fhp->fh_maxsize, parent->d_name.name, dentry->d_name.name);
381 fhp->fh_dentry = dget(dentry); /* our internal copy */
382 fhp->fh_export = exp;
385 if (ref_fh_version == 0xca) {
386 /* old style filehandle please */
387 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
388 fhp->fh_handle.fh_size = NFS_FHSIZE;
389 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
390 fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev);
391 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
392 fhp->fh_handle.ofh_xino = ino_t_to_u32(exp->ex_dentry->d_inode->i_ino);
393 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
395 _fh_update_old(dentry, exp, &fhp->fh_handle);
398 fhp->fh_handle.fh_version = 1;
399 fhp->fh_handle.fh_auth_type = 0;
400 datap = fhp->fh_handle.fh_auth+0;
401 fhp->fh_handle.fh_fsid_type = ref_fh_fsid_type;
402 switch (ref_fh_fsid_type) {
406 * 2byte major, 2byte minor, 4byte inode
408 mk_fsid_v0(datap, ex_dev,
409 exp->ex_dentry->d_inode->i_ino);
412 /* fsid_type 1 == 4 bytes filesystem id */
413 mk_fsid_v1(datap, exp->ex_fsid);
418 * 4byte major, 4byte minor, 4byte inode
420 mk_fsid_v2(datap, ex_dev,
421 exp->ex_dentry->d_inode->i_ino);
426 * 4byte devicenumber, 4byte inode
428 mk_fsid_v3(datap, ex_dev,
429 exp->ex_dentry->d_inode->i_ino);
432 len = key_len(ref_fh_fsid_type);
434 fhp->fh_handle.fh_size = 4 + len;
437 int size = (fhp->fh_maxsize-len-4)/4;
438 fhp->fh_handle.fh_fileid_type =
439 _fh_update(dentry, exp, datap, &size);
440 fhp->fh_handle.fh_size += size*4;
442 if (fhp->fh_handle.fh_fileid_type == 255)
443 return nfserr_opnotsupp;
451 * Update file handle information after changing a dentry.
452 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
455 fh_update(struct svc_fh *fhp)
457 struct dentry *dentry;
463 dentry = fhp->fh_dentry;
464 if (!dentry->d_inode)
466 if (fhp->fh_handle.fh_version != 1) {
467 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
470 if (fhp->fh_handle.fh_fileid_type != 0)
472 datap = fhp->fh_handle.fh_auth+
473 fhp->fh_handle.fh_size/4 -1;
474 size = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
475 fhp->fh_handle.fh_fileid_type =
476 _fh_update(dentry, fhp->fh_export, datap, &size);
477 fhp->fh_handle.fh_size += size*4;
478 if (fhp->fh_handle.fh_fileid_type == 255)
479 return nfserr_opnotsupp;
485 printk(KERN_ERR "fh_update: fh not verified!\n");
488 printk(KERN_ERR "fh_update: %s/%s still negative!\n",
489 dentry->d_parent->d_name.name, dentry->d_name.name);
494 * Release a file handle.
497 fh_put(struct svc_fh *fhp)
499 struct dentry * dentry = fhp->fh_dentry;
500 struct svc_export * exp = fhp->fh_export;
503 fhp->fh_dentry = NULL;
505 #ifdef CONFIG_NFSD_V3
506 fhp->fh_pre_saved = 0;
507 fhp->fh_post_saved = 0;
512 cache_put(&exp->h, &svc_export_cache);
513 fhp->fh_export = NULL;
519 * Shorthand for dprintk()'s
521 char * SVCFH_fmt(struct svc_fh *fhp)
523 struct knfsd_fh *fh = &fhp->fh_handle;
526 sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
528 fh->fh_base.fh_pad[0],
529 fh->fh_base.fh_pad[1],
530 fh->fh_base.fh_pad[2],
531 fh->fh_base.fh_pad[3],
532 fh->fh_base.fh_pad[4],
533 fh->fh_base.fh_pad[5]);