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Commit | Line | Data |
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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 | ||
31 | static int nfsd_nr_verified; | |
32 | static int nfsd_nr_put; | |
33 | ||
34 | extern 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 | */ | |
44 | static 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 | */ | |
79 | static inline int | |
80 | nfsd_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 | */ | |
113 | u32 | |
114 | fh_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 | ||
190 | /* Set user creds for this exportpoint */ | |
191 | error = nfsd_setuser(rqstp, exp); | |
192 | if (error) { | |
193 | error = nfserrno(error); | |
194 | goto out; | |
195 | } | |
196 | ||
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; | |
251 | } | |
252 | cache_get(&exp->h); | |
253 | ||
254 | error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type); | |
255 | if (error) | |
256 | goto out; | |
257 | ||
258 | /* Finally, check access permissions. */ | |
259 | error = nfsd_permission(exp, dentry, access); | |
260 | ||
261 | #ifdef NFSD_PARANOIA_EXTREME | |
262 | if (error) { | |
263 | printk("fh_verify: %s/%s permission failure, acc=%x, error=%d\n", | |
264 | dentry->d_parent->d_name.name, dentry->d_name.name, access, (error >> 24)); | |
265 | } | |
266 | #endif | |
267 | out: | |
268 | if (exp && !IS_ERR(exp)) | |
269 | exp_put(exp); | |
270 | if (error == nfserr_stale) | |
271 | nfsdstats.fh_stale++; | |
272 | return error; | |
273 | } | |
274 | ||
275 | ||
276 | /* | |
277 | * Compose a file handle for an NFS reply. | |
278 | * | |
279 | * Note that when first composed, the dentry may not yet have | |
280 | * an inode. In this case a call to fh_update should be made | |
281 | * before the fh goes out on the wire ... | |
282 | */ | |
283 | static inline int _fh_update(struct dentry *dentry, struct svc_export *exp, | |
284 | __u32 *datap, int *maxsize) | |
285 | { | |
286 | struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op; | |
287 | ||
288 | if (dentry == exp->ex_dentry) { | |
289 | *maxsize = 0; | |
290 | return 0; | |
291 | } | |
292 | ||
293 | return CALL(nop,encode_fh)(dentry, datap, maxsize, | |
294 | !(exp->ex_flags&NFSEXP_NOSUBTREECHECK)); | |
295 | } | |
296 | ||
297 | /* | |
298 | * for composing old style file handles | |
299 | */ | |
300 | static inline void _fh_update_old(struct dentry *dentry, | |
301 | struct svc_export *exp, | |
302 | struct knfsd_fh *fh) | |
303 | { | |
304 | fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino); | |
305 | fh->ofh_generation = dentry->d_inode->i_generation; | |
306 | if (S_ISDIR(dentry->d_inode->i_mode) || | |
307 | (exp->ex_flags & NFSEXP_NOSUBTREECHECK)) | |
308 | fh->ofh_dirino = 0; | |
309 | } | |
310 | ||
311 | int | |
312 | fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry, struct svc_fh *ref_fh) | |
313 | { | |
314 | /* ref_fh is a reference file handle. | |
315 | * if it is non-null, then we should compose a filehandle which is | |
316 | * of the same version, where possible. | |
317 | * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca | |
318 | * Then create a 32byte filehandle using nfs_fhbase_old | |
319 | * | |
320 | */ | |
321 | ||
322 | u8 ref_fh_version = 0; | |
323 | u8 ref_fh_fsid_type = 0; | |
324 | struct inode * inode = dentry->d_inode; | |
325 | struct dentry *parent = dentry->d_parent; | |
326 | __u32 *datap; | |
327 | dev_t ex_dev = exp->ex_dentry->d_inode->i_sb->s_dev; | |
328 | ||
329 | dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n", | |
330 | MAJOR(ex_dev), MINOR(ex_dev), | |
331 | (long) exp->ex_dentry->d_inode->i_ino, | |
332 | parent->d_name.name, dentry->d_name.name, | |
333 | (inode ? inode->i_ino : 0)); | |
334 | ||
335 | if (ref_fh) { | |
336 | ref_fh_version = ref_fh->fh_handle.fh_version; | |
337 | if (ref_fh_version == 0xca) | |
338 | ref_fh_fsid_type = 0; | |
339 | else | |
340 | ref_fh_fsid_type = ref_fh->fh_handle.fh_fsid_type; | |
341 | if (ref_fh_fsid_type > 3) | |
342 | ref_fh_fsid_type = 0; | |
343 | ||
344 | /* make sure ref_fh type works for given export */ | |
345 | if (ref_fh_fsid_type == 1 && | |
346 | !(exp->ex_flags & NFSEXP_FSID)) { | |
347 | /* if we don't have an fsid, we cannot provide one... */ | |
348 | ref_fh_fsid_type = 0; | |
349 | } | |
350 | } else if (exp->ex_flags & NFSEXP_FSID) | |
351 | ref_fh_fsid_type = 1; | |
352 | ||
353 | if (!old_valid_dev(ex_dev) && ref_fh_fsid_type == 0) { | |
354 | /* for newer device numbers, we must use a newer fsid format */ | |
355 | ref_fh_version = 1; | |
356 | ref_fh_fsid_type = 3; | |
357 | } | |
358 | if (old_valid_dev(ex_dev) && | |
359 | (ref_fh_fsid_type == 2 || ref_fh_fsid_type == 3)) | |
360 | /* must use type1 for smaller device numbers */ | |
361 | ref_fh_fsid_type = 0; | |
362 | ||
363 | if (ref_fh == fhp) | |
364 | fh_put(ref_fh); | |
365 | ||
366 | if (fhp->fh_locked || fhp->fh_dentry) { | |
367 | printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n", | |
368 | parent->d_name.name, dentry->d_name.name); | |
369 | } | |
370 | if (fhp->fh_maxsize < NFS_FHSIZE) | |
371 | printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n", | |
372 | fhp->fh_maxsize, parent->d_name.name, dentry->d_name.name); | |
373 | ||
374 | fhp->fh_dentry = dget(dentry); /* our internal copy */ | |
375 | fhp->fh_export = exp; | |
376 | cache_get(&exp->h); | |
377 | ||
378 | if (ref_fh_version == 0xca) { | |
379 | /* old style filehandle please */ | |
380 | memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE); | |
381 | fhp->fh_handle.fh_size = NFS_FHSIZE; | |
382 | fhp->fh_handle.ofh_dcookie = 0xfeebbaca; | |
383 | fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev); | |
384 | fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev; | |
385 | fhp->fh_handle.ofh_xino = ino_t_to_u32(exp->ex_dentry->d_inode->i_ino); | |
386 | fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry)); | |
387 | if (inode) | |
388 | _fh_update_old(dentry, exp, &fhp->fh_handle); | |
389 | } else { | |
390 | int len; | |
391 | fhp->fh_handle.fh_version = 1; | |
392 | fhp->fh_handle.fh_auth_type = 0; | |
393 | datap = fhp->fh_handle.fh_auth+0; | |
394 | fhp->fh_handle.fh_fsid_type = ref_fh_fsid_type; | |
395 | switch (ref_fh_fsid_type) { | |
396 | case 0: | |
397 | /* | |
398 | * fsid_type 0: | |
399 | * 2byte major, 2byte minor, 4byte inode | |
400 | */ | |
401 | mk_fsid_v0(datap, ex_dev, | |
402 | exp->ex_dentry->d_inode->i_ino); | |
403 | break; | |
404 | case 1: | |
405 | /* fsid_type 1 == 4 bytes filesystem id */ | |
406 | mk_fsid_v1(datap, exp->ex_fsid); | |
407 | break; | |
408 | case 2: | |
409 | /* | |
410 | * fsid_type 2: | |
411 | * 4byte major, 4byte minor, 4byte inode | |
412 | */ | |
413 | mk_fsid_v2(datap, ex_dev, | |
414 | exp->ex_dentry->d_inode->i_ino); | |
415 | break; | |
416 | case 3: | |
417 | /* | |
418 | * fsid_type 3: | |
419 | * 4byte devicenumber, 4byte inode | |
420 | */ | |
421 | mk_fsid_v3(datap, ex_dev, | |
422 | exp->ex_dentry->d_inode->i_ino); | |
423 | break; | |
424 | } | |
425 | len = key_len(ref_fh_fsid_type); | |
426 | datap += len/4; | |
427 | fhp->fh_handle.fh_size = 4 + len; | |
428 | ||
429 | if (inode) { | |
430 | int size = (fhp->fh_maxsize-len-4)/4; | |
431 | fhp->fh_handle.fh_fileid_type = | |
432 | _fh_update(dentry, exp, datap, &size); | |
433 | fhp->fh_handle.fh_size += size*4; | |
434 | } | |
435 | if (fhp->fh_handle.fh_fileid_type == 255) | |
436 | return nfserr_opnotsupp; | |
437 | } | |
438 | ||
439 | nfsd_nr_verified++; | |
440 | return 0; | |
441 | } | |
442 | ||
443 | /* | |
444 | * Update file handle information after changing a dentry. | |
445 | * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create | |
446 | */ | |
447 | int | |
448 | fh_update(struct svc_fh *fhp) | |
449 | { | |
450 | struct dentry *dentry; | |
451 | __u32 *datap; | |
452 | ||
453 | if (!fhp->fh_dentry) | |
454 | goto out_bad; | |
455 | ||
456 | dentry = fhp->fh_dentry; | |
457 | if (!dentry->d_inode) | |
458 | goto out_negative; | |
459 | if (fhp->fh_handle.fh_version != 1) { | |
460 | _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle); | |
461 | } else { | |
462 | int size; | |
463 | if (fhp->fh_handle.fh_fileid_type != 0) | |
464 | goto out_uptodate; | |
465 | datap = fhp->fh_handle.fh_auth+ | |
466 | fhp->fh_handle.fh_size/4 -1; | |
467 | size = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4; | |
468 | fhp->fh_handle.fh_fileid_type = | |
469 | _fh_update(dentry, fhp->fh_export, datap, &size); | |
470 | fhp->fh_handle.fh_size += size*4; | |
471 | if (fhp->fh_handle.fh_fileid_type == 255) | |
472 | return nfserr_opnotsupp; | |
473 | } | |
474 | out: | |
475 | return 0; | |
476 | ||
477 | out_bad: | |
478 | printk(KERN_ERR "fh_update: fh not verified!\n"); | |
479 | goto out; | |
480 | out_negative: | |
481 | printk(KERN_ERR "fh_update: %s/%s still negative!\n", | |
482 | dentry->d_parent->d_name.name, dentry->d_name.name); | |
483 | goto out; | |
484 | out_uptodate: | |
485 | printk(KERN_ERR "fh_update: %s/%s already up-to-date!\n", | |
486 | dentry->d_parent->d_name.name, dentry->d_name.name); | |
487 | goto out; | |
488 | } | |
489 | ||
490 | /* | |
491 | * Release a file handle. | |
492 | */ | |
493 | void | |
494 | fh_put(struct svc_fh *fhp) | |
495 | { | |
496 | struct dentry * dentry = fhp->fh_dentry; | |
497 | struct svc_export * exp = fhp->fh_export; | |
498 | if (dentry) { | |
499 | fh_unlock(fhp); | |
500 | fhp->fh_dentry = NULL; | |
501 | dput(dentry); | |
502 | #ifdef CONFIG_NFSD_V3 | |
503 | fhp->fh_pre_saved = 0; | |
504 | fhp->fh_post_saved = 0; | |
505 | #endif | |
506 | nfsd_nr_put++; | |
507 | } | |
508 | if (exp) { | |
509 | svc_export_put(&exp->h, &svc_export_cache); | |
510 | fhp->fh_export = NULL; | |
511 | } | |
512 | return; | |
513 | } | |
514 | ||
515 | /* | |
516 | * Shorthand for dprintk()'s | |
517 | */ | |
518 | char * SVCFH_fmt(struct svc_fh *fhp) | |
519 | { | |
520 | struct knfsd_fh *fh = &fhp->fh_handle; | |
521 | ||
522 | static char buf[80]; | |
523 | sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x", | |
524 | fh->fh_size, | |
525 | fh->fh_base.fh_pad[0], | |
526 | fh->fh_base.fh_pad[1], | |
527 | fh->fh_base.fh_pad[2], | |
528 | fh->fh_base.fh_pad[3], | |
529 | fh->fh_base.fh_pad[4], | |
530 | fh->fh_base.fh_pad[5]); | |
531 | return buf; | |
532 | } |