blob: 057aff745506da64d5ca6b61d00f0eb41c597029 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#define MSNFS /* HACK HACK */
2/*
3 * linux/fs/nfsd/export.c
4 *
5 * NFS exporting and validation.
6 *
7 * We maintain a list of clients, each of which has a list of
8 * exports. To export an fs to a given client, you first have
9 * to create the client entry with NFSCTL_ADDCLIENT, which
10 * creates a client control block and adds it to the hash
11 * table. Then, you call NFSCTL_EXPORT for each fs.
12 *
13 *
14 * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
15 */
16
17#include <linux/unistd.h>
18#include <linux/slab.h>
19#include <linux/sched.h>
20#include <linux/stat.h>
21#include <linux/in.h>
22#include <linux/seq_file.h>
23#include <linux/syscalls.h>
24#include <linux/rwsem.h>
25#include <linux/dcache.h>
26#include <linux/namei.h>
27#include <linux/mount.h>
28#include <linux/hash.h>
Bruce Allanf35279d2005-09-06 15:17:08 -070029#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
31#include <linux/sunrpc/svc.h>
32#include <linux/nfsd/nfsd.h>
33#include <linux/nfsd/nfsfh.h>
34#include <linux/nfsd/syscall.h>
35#include <linux/lockd/bind.h>
36
37#define NFSDDBG_FACILITY NFSDDBG_EXPORT
38#define NFSD_PARANOIA 1
39
40typedef struct auth_domain svc_client;
41typedef struct svc_export svc_export;
42
43static void exp_do_unexport(svc_export *unexp);
44static int exp_verify_string(char *cp, int max);
45
46/*
47 * We have two caches.
48 * One maps client+vfsmnt+dentry to export options - the export map
49 * The other maps client+filehandle-fragment to export options. - the expkey map
50 *
51 * The export options are actually stored in the first map, and the
52 * second map contains a reference to the entry in the first map.
53 */
54
55#define EXPKEY_HASHBITS 8
56#define EXPKEY_HASHMAX (1 << EXPKEY_HASHBITS)
57#define EXPKEY_HASHMASK (EXPKEY_HASHMAX -1)
58static struct cache_head *expkey_table[EXPKEY_HASHMAX];
59
60static inline int svc_expkey_hash(struct svc_expkey *item)
61{
62 int hash = item->ek_fsidtype;
63 char * cp = (char*)item->ek_fsid;
64 int len = key_len(item->ek_fsidtype);
65
66 hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
67 hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
68 return hash & EXPKEY_HASHMASK;
69}
70
71void expkey_put(struct cache_head *item, struct cache_detail *cd)
72{
73 if (cache_put(item, cd)) {
74 struct svc_expkey *key = container_of(item, struct svc_expkey, h);
75 if (test_bit(CACHE_VALID, &item->flags) &&
76 !test_bit(CACHE_NEGATIVE, &item->flags))
77 exp_put(key->ek_export);
78 auth_domain_put(key->ek_client);
79 kfree(key);
80 }
81}
82
83static void expkey_request(struct cache_detail *cd,
84 struct cache_head *h,
85 char **bpp, int *blen)
86{
87 /* client fsidtype \xfsid */
88 struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
89 char type[5];
90
91 qword_add(bpp, blen, ek->ek_client->name);
92 snprintf(type, 5, "%d", ek->ek_fsidtype);
93 qword_add(bpp, blen, type);
94 qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
95 (*bpp)[-1] = '\n';
96}
97
98static struct svc_expkey *svc_expkey_lookup(struct svc_expkey *, int);
99static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
100{
101 /* client fsidtype fsid [path] */
102 char *buf;
103 int len;
104 struct auth_domain *dom = NULL;
105 int err;
106 int fsidtype;
107 char *ep;
108 struct svc_expkey key;
109
110 if (mesg[mlen-1] != '\n')
111 return -EINVAL;
112 mesg[mlen-1] = 0;
113
114 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
115 err = -ENOMEM;
116 if (!buf) goto out;
117
118 err = -EINVAL;
119 if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
120 goto out;
121
122 err = -ENOENT;
123 dom = auth_domain_find(buf);
124 if (!dom)
125 goto out;
126 dprintk("found domain %s\n", buf);
127
128 err = -EINVAL;
129 if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
130 goto out;
131 fsidtype = simple_strtoul(buf, &ep, 10);
132 if (*ep)
133 goto out;
134 dprintk("found fsidtype %d\n", fsidtype);
135 if (fsidtype > 2)
136 goto out;
137 if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
138 goto out;
139 dprintk("found fsid length %d\n", len);
140 if (len != key_len(fsidtype))
141 goto out;
142
143 /* OK, we seem to have a valid key */
144 key.h.flags = 0;
145 key.h.expiry_time = get_expiry(&mesg);
146 if (key.h.expiry_time == 0)
147 goto out;
148
149 key.ek_client = dom;
150 key.ek_fsidtype = fsidtype;
151 memcpy(key.ek_fsid, buf, len);
152
153 /* now we want a pathname, or empty meaning NEGATIVE */
154 if ((len=qword_get(&mesg, buf, PAGE_SIZE)) < 0)
155 goto out;
156 dprintk("Path seems to be <%s>\n", buf);
157 err = 0;
158 if (len == 0) {
159 struct svc_expkey *ek;
160 set_bit(CACHE_NEGATIVE, &key.h.flags);
161 ek = svc_expkey_lookup(&key, 1);
162 if (ek)
163 expkey_put(&ek->h, &svc_expkey_cache);
164 } else {
165 struct nameidata nd;
166 struct svc_expkey *ek;
167 struct svc_export *exp;
168 err = path_lookup(buf, 0, &nd);
169 if (err)
170 goto out;
171
172 dprintk("Found the path %s\n", buf);
173 exp = exp_get_by_name(dom, nd.mnt, nd.dentry, NULL);
174
175 err = -ENOENT;
176 if (!exp)
177 goto out_nd;
178 key.ek_export = exp;
179 dprintk("And found export\n");
180
181 ek = svc_expkey_lookup(&key, 1);
182 if (ek)
183 expkey_put(&ek->h, &svc_expkey_cache);
184 exp_put(exp);
185 err = 0;
186 out_nd:
187 path_release(&nd);
188 }
189 cache_flush();
190 out:
191 if (dom)
192 auth_domain_put(dom);
193 if (buf)
194 kfree(buf);
195 return err;
196}
197
198static int expkey_show(struct seq_file *m,
199 struct cache_detail *cd,
200 struct cache_head *h)
201{
202 struct svc_expkey *ek ;
203
204 if (h ==NULL) {
205 seq_puts(m, "#domain fsidtype fsid [path]\n");
206 return 0;
207 }
208 ek = container_of(h, struct svc_expkey, h);
209 seq_printf(m, "%s %d 0x%08x", ek->ek_client->name,
210 ek->ek_fsidtype, ek->ek_fsid[0]);
211 if (ek->ek_fsidtype != 1)
212 seq_printf(m, "%08x", ek->ek_fsid[1]);
213 if (ek->ek_fsidtype == 2)
214 seq_printf(m, "%08x", ek->ek_fsid[2]);
215 if (test_bit(CACHE_VALID, &h->flags) &&
216 !test_bit(CACHE_NEGATIVE, &h->flags)) {
217 seq_printf(m, " ");
218 seq_path(m, ek->ek_export->ex_mnt, ek->ek_export->ex_dentry, "\\ \t\n");
219 }
220 seq_printf(m, "\n");
221 return 0;
222}
223
224struct cache_detail svc_expkey_cache = {
Bruce Allanf35279d2005-09-06 15:17:08 -0700225 .owner = THIS_MODULE,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 .hash_size = EXPKEY_HASHMAX,
227 .hash_table = expkey_table,
228 .name = "nfsd.fh",
229 .cache_put = expkey_put,
230 .cache_request = expkey_request,
231 .cache_parse = expkey_parse,
232 .cache_show = expkey_show,
233};
234
235static inline int svc_expkey_match (struct svc_expkey *a, struct svc_expkey *b)
236{
237 if (a->ek_fsidtype != b->ek_fsidtype ||
238 a->ek_client != b->ek_client ||
239 memcmp(a->ek_fsid, b->ek_fsid, key_len(a->ek_fsidtype)) != 0)
240 return 0;
241 return 1;
242}
243
244static inline void svc_expkey_init(struct svc_expkey *new, struct svc_expkey *item)
245{
246 cache_get(&item->ek_client->h);
247 new->ek_client = item->ek_client;
248 new->ek_fsidtype = item->ek_fsidtype;
249 new->ek_fsid[0] = item->ek_fsid[0];
250 new->ek_fsid[1] = item->ek_fsid[1];
251 new->ek_fsid[2] = item->ek_fsid[2];
252}
253
254static inline void svc_expkey_update(struct svc_expkey *new, struct svc_expkey *item)
255{
256 cache_get(&item->ek_export->h);
257 new->ek_export = item->ek_export;
258}
259
260static DefineSimpleCacheLookup(svc_expkey,0) /* no inplace updates */
261
262#define EXPORT_HASHBITS 8
263#define EXPORT_HASHMAX (1<< EXPORT_HASHBITS)
264#define EXPORT_HASHMASK (EXPORT_HASHMAX -1)
265
266static struct cache_head *export_table[EXPORT_HASHMAX];
267
268static inline int svc_export_hash(struct svc_export *item)
269{
270 int rv;
271
272 rv = hash_ptr(item->ex_client, EXPORT_HASHBITS);
273 rv ^= hash_ptr(item->ex_dentry, EXPORT_HASHBITS);
274 rv ^= hash_ptr(item->ex_mnt, EXPORT_HASHBITS);
275 return rv;
276}
277
278void svc_export_put(struct cache_head *item, struct cache_detail *cd)
279{
280 if (cache_put(item, cd)) {
281 struct svc_export *exp = container_of(item, struct svc_export, h);
282 dput(exp->ex_dentry);
283 mntput(exp->ex_mnt);
284 auth_domain_put(exp->ex_client);
285 kfree(exp);
286 }
287}
288
289static void svc_export_request(struct cache_detail *cd,
290 struct cache_head *h,
291 char **bpp, int *blen)
292{
293 /* client path */
294 struct svc_export *exp = container_of(h, struct svc_export, h);
295 char *pth;
296
297 qword_add(bpp, blen, exp->ex_client->name);
298 pth = d_path(exp->ex_dentry, exp->ex_mnt, *bpp, *blen);
299 if (IS_ERR(pth)) {
300 /* is this correct? */
301 (*bpp)[0] = '\n';
302 return;
303 }
304 qword_add(bpp, blen, pth);
305 (*bpp)[-1] = '\n';
306}
307
308static struct svc_export *svc_export_lookup(struct svc_export *, int);
309
310static int check_export(struct inode *inode, int flags)
311{
312
313 /* We currently export only dirs and regular files.
314 * This is what umountd does.
315 */
316 if (!S_ISDIR(inode->i_mode) &&
317 !S_ISREG(inode->i_mode))
318 return -ENOTDIR;
319
320 /* There are two requirements on a filesystem to be exportable.
321 * 1: We must be able to identify the filesystem from a number.
322 * either a device number (so FS_REQUIRES_DEV needed)
323 * or an FSID number (so NFSEXP_FSID needed).
324 * 2: We must be able to find an inode from a filehandle.
325 * This means that s_export_op must be set.
326 */
327 if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
328 !(flags & NFSEXP_FSID)) {
329 dprintk("exp_export: export of non-dev fs without fsid");
330 return -EINVAL;
331 }
332 if (!inode->i_sb->s_export_op) {
333 dprintk("exp_export: export of invalid fs type.\n");
334 return -EINVAL;
335 }
336
337 /* Ok, we can export it */;
338 if (!inode->i_sb->s_export_op->find_exported_dentry)
339 inode->i_sb->s_export_op->find_exported_dentry =
340 find_exported_dentry;
341 return 0;
342
343}
344
345static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
346{
347 /* client path expiry [flags anonuid anongid fsid] */
348 char *buf;
349 int len;
350 int err;
351 struct auth_domain *dom = NULL;
352 struct nameidata nd;
353 struct svc_export exp, *expp;
354 int an_int;
355
356 nd.dentry = NULL;
357
358 if (mesg[mlen-1] != '\n')
359 return -EINVAL;
360 mesg[mlen-1] = 0;
361
362 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
363 err = -ENOMEM;
364 if (!buf) goto out;
365
366 /* client */
367 len = qword_get(&mesg, buf, PAGE_SIZE);
368 err = -EINVAL;
369 if (len <= 0) goto out;
370
371 err = -ENOENT;
372 dom = auth_domain_find(buf);
373 if (!dom)
374 goto out;
375
376 /* path */
377 err = -EINVAL;
378 if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
379 goto out;
380 err = path_lookup(buf, 0, &nd);
381 if (err) goto out;
382
383 exp.h.flags = 0;
384 exp.ex_client = dom;
385 exp.ex_mnt = nd.mnt;
386 exp.ex_dentry = nd.dentry;
387
388 /* expiry */
389 err = -EINVAL;
390 exp.h.expiry_time = get_expiry(&mesg);
391 if (exp.h.expiry_time == 0)
392 goto out;
393
394 /* flags */
395 err = get_int(&mesg, &an_int);
396 if (err == -ENOENT)
397 set_bit(CACHE_NEGATIVE, &exp.h.flags);
398 else {
399 if (err || an_int < 0) goto out;
400 exp.ex_flags= an_int;
401
402 /* anon uid */
403 err = get_int(&mesg, &an_int);
404 if (err) goto out;
405 exp.ex_anon_uid= an_int;
406
407 /* anon gid */
408 err = get_int(&mesg, &an_int);
409 if (err) goto out;
410 exp.ex_anon_gid= an_int;
411
412 /* fsid */
413 err = get_int(&mesg, &an_int);
414 if (err) goto out;
415 exp.ex_fsid = an_int;
416
417 err = check_export(nd.dentry->d_inode, exp.ex_flags);
418 if (err) goto out;
419 }
420
421 expp = svc_export_lookup(&exp, 1);
422 if (expp)
423 exp_put(expp);
424 err = 0;
425 cache_flush();
426 out:
427 if (nd.dentry)
428 path_release(&nd);
429 if (dom)
430 auth_domain_put(dom);
431 if (buf)
432 kfree(buf);
433 return err;
434}
435
436static void exp_flags(struct seq_file *m, int flag, int fsid, uid_t anonu, uid_t anong);
437
438static int svc_export_show(struct seq_file *m,
439 struct cache_detail *cd,
440 struct cache_head *h)
441{
442 struct svc_export *exp ;
443
444 if (h ==NULL) {
445 seq_puts(m, "#path domain(flags)\n");
446 return 0;
447 }
448 exp = container_of(h, struct svc_export, h);
449 seq_path(m, exp->ex_mnt, exp->ex_dentry, " \t\n\\");
450 seq_putc(m, '\t');
451 seq_escape(m, exp->ex_client->name, " \t\n\\");
452 seq_putc(m, '(');
453 if (test_bit(CACHE_VALID, &h->flags) &&
454 !test_bit(CACHE_NEGATIVE, &h->flags))
455 exp_flags(m, exp->ex_flags, exp->ex_fsid,
456 exp->ex_anon_uid, exp->ex_anon_gid);
457 seq_puts(m, ")\n");
458 return 0;
459}
460struct cache_detail svc_export_cache = {
Bruce Allanf35279d2005-09-06 15:17:08 -0700461 .owner = THIS_MODULE,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 .hash_size = EXPORT_HASHMAX,
463 .hash_table = export_table,
464 .name = "nfsd.export",
465 .cache_put = svc_export_put,
466 .cache_request = svc_export_request,
467 .cache_parse = svc_export_parse,
468 .cache_show = svc_export_show,
469};
470
471static inline int svc_export_match(struct svc_export *a, struct svc_export *b)
472{
473 return a->ex_client == b->ex_client &&
474 a->ex_dentry == b->ex_dentry &&
475 a->ex_mnt == b->ex_mnt;
476}
477static inline void svc_export_init(struct svc_export *new, struct svc_export *item)
478{
479 cache_get(&item->ex_client->h);
480 new->ex_client = item->ex_client;
481 new->ex_dentry = dget(item->ex_dentry);
482 new->ex_mnt = mntget(item->ex_mnt);
483}
484
485static inline void svc_export_update(struct svc_export *new, struct svc_export *item)
486{
487 new->ex_flags = item->ex_flags;
488 new->ex_anon_uid = item->ex_anon_uid;
489 new->ex_anon_gid = item->ex_anon_gid;
490 new->ex_fsid = item->ex_fsid;
491}
492
493static DefineSimpleCacheLookup(svc_export,1) /* allow inplace updates */
494
495
496struct svc_expkey *
497exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv, struct cache_req *reqp)
498{
499 struct svc_expkey key, *ek;
500 int err;
501
502 if (!clp)
503 return NULL;
504
505 key.ek_client = clp;
506 key.ek_fsidtype = fsid_type;
507 memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
508
509 ek = svc_expkey_lookup(&key, 0);
510 if (ek != NULL)
511 if ((err = cache_check(&svc_expkey_cache, &ek->h, reqp)))
512 ek = ERR_PTR(err);
513 return ek;
514}
515
516static int exp_set_key(svc_client *clp, int fsid_type, u32 *fsidv,
517 struct svc_export *exp)
518{
519 struct svc_expkey key, *ek;
520
521 key.ek_client = clp;
522 key.ek_fsidtype = fsid_type;
523 memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
524 key.ek_export = exp;
525 key.h.expiry_time = NEVER;
526 key.h.flags = 0;
527
528 ek = svc_expkey_lookup(&key, 1);
529 if (ek) {
530 expkey_put(&ek->h, &svc_expkey_cache);
531 return 0;
532 }
533 return -ENOMEM;
534}
535
536/*
537 * Find the client's export entry matching xdev/xino.
538 */
539static inline struct svc_expkey *
540exp_get_key(svc_client *clp, dev_t dev, ino_t ino)
541{
542 u32 fsidv[3];
543
544 if (old_valid_dev(dev)) {
545 mk_fsid_v0(fsidv, dev, ino);
546 return exp_find_key(clp, 0, fsidv, NULL);
547 }
548 mk_fsid_v3(fsidv, dev, ino);
549 return exp_find_key(clp, 3, fsidv, NULL);
550}
551
552/*
553 * Find the client's export entry matching fsid
554 */
555static inline struct svc_expkey *
556exp_get_fsid_key(svc_client *clp, int fsid)
557{
558 u32 fsidv[2];
559
560 mk_fsid_v1(fsidv, fsid);
561
562 return exp_find_key(clp, 1, fsidv, NULL);
563}
564
565svc_export *
566exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
567 struct cache_req *reqp)
568{
569 struct svc_export *exp, key;
570
571 if (!clp)
572 return NULL;
573
574 key.ex_client = clp;
575 key.ex_mnt = mnt;
576 key.ex_dentry = dentry;
577
578 exp = svc_export_lookup(&key, 0);
579 if (exp != NULL)
580 switch (cache_check(&svc_export_cache, &exp->h, reqp)) {
581 case 0: break;
582 case -EAGAIN:
583 exp = ERR_PTR(-EAGAIN);
584 break;
585 default:
586 exp = NULL;
587 }
588
589 return exp;
590}
591
592/*
593 * Find the export entry for a given dentry.
594 */
595struct svc_export *
596exp_parent(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
597 struct cache_req *reqp)
598{
599 svc_export *exp;
600
601 dget(dentry);
602 exp = exp_get_by_name(clp, mnt, dentry, reqp);
603
604 while (exp == NULL && !IS_ROOT(dentry)) {
605 struct dentry *parent;
606
607 parent = dget_parent(dentry);
608 dput(dentry);
609 dentry = parent;
610 exp = exp_get_by_name(clp, mnt, dentry, reqp);
611 }
612 dput(dentry);
613 return exp;
614}
615
616/*
617 * Hashtable locking. Write locks are placed only by user processes
618 * wanting to modify export information.
619 * Write locking only done in this file. Read locking
620 * needed externally.
621 */
622
623static DECLARE_RWSEM(hash_sem);
624
625void
626exp_readlock(void)
627{
628 down_read(&hash_sem);
629}
630
631static inline void
632exp_writelock(void)
633{
634 down_write(&hash_sem);
635}
636
637void
638exp_readunlock(void)
639{
640 up_read(&hash_sem);
641}
642
643static inline void
644exp_writeunlock(void)
645{
646 up_write(&hash_sem);
647}
648
649static void exp_fsid_unhash(struct svc_export *exp)
650{
651 struct svc_expkey *ek;
652
653 if ((exp->ex_flags & NFSEXP_FSID) == 0)
654 return;
655
656 ek = exp_get_fsid_key(exp->ex_client, exp->ex_fsid);
657 if (ek && !IS_ERR(ek)) {
658 ek->h.expiry_time = get_seconds()-1;
659 expkey_put(&ek->h, &svc_expkey_cache);
660 }
661 svc_expkey_cache.nextcheck = get_seconds();
662}
663
664static int exp_fsid_hash(svc_client *clp, struct svc_export *exp)
665{
666 u32 fsid[2];
667
668 if ((exp->ex_flags & NFSEXP_FSID) == 0)
669 return 0;
670
671 mk_fsid_v1(fsid, exp->ex_fsid);
672 return exp_set_key(clp, 1, fsid, exp);
673}
674
675static int exp_hash(struct auth_domain *clp, struct svc_export *exp)
676{
677 u32 fsid[2];
678 struct inode *inode = exp->ex_dentry->d_inode;
679 dev_t dev = inode->i_sb->s_dev;
680
681 if (old_valid_dev(dev)) {
682 mk_fsid_v0(fsid, dev, inode->i_ino);
683 return exp_set_key(clp, 0, fsid, exp);
684 }
685 mk_fsid_v3(fsid, dev, inode->i_ino);
686 return exp_set_key(clp, 3, fsid, exp);
687}
688
689static void exp_unhash(struct svc_export *exp)
690{
691 struct svc_expkey *ek;
692 struct inode *inode = exp->ex_dentry->d_inode;
693
694 ek = exp_get_key(exp->ex_client, inode->i_sb->s_dev, inode->i_ino);
695 if (ek && !IS_ERR(ek)) {
696 ek->h.expiry_time = get_seconds()-1;
697 expkey_put(&ek->h, &svc_expkey_cache);
698 }
699 svc_expkey_cache.nextcheck = get_seconds();
700}
701
702/*
703 * Export a file system.
704 */
705int
706exp_export(struct nfsctl_export *nxp)
707{
708 svc_client *clp;
709 struct svc_export *exp = NULL;
710 struct svc_export new;
711 struct svc_expkey *fsid_key = NULL;
712 struct nameidata nd;
713 int err;
714
715 /* Consistency check */
716 err = -EINVAL;
717 if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
718 !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
719 goto out;
720
721 dprintk("exp_export called for %s:%s (%x/%ld fl %x).\n",
722 nxp->ex_client, nxp->ex_path,
723 (unsigned)nxp->ex_dev, (long)nxp->ex_ino,
724 nxp->ex_flags);
725
726 /* Try to lock the export table for update */
727 exp_writelock();
728
729 /* Look up client info */
730 if (!(clp = auth_domain_find(nxp->ex_client)))
731 goto out_unlock;
732
733
734 /* Look up the dentry */
735 err = path_lookup(nxp->ex_path, 0, &nd);
736 if (err)
737 goto out_unlock;
738 err = -EINVAL;
739
740 exp = exp_get_by_name(clp, nd.mnt, nd.dentry, NULL);
741
742 /* must make sure there won't be an ex_fsid clash */
743 if ((nxp->ex_flags & NFSEXP_FSID) &&
744 (fsid_key = exp_get_fsid_key(clp, nxp->ex_dev)) &&
745 !IS_ERR(fsid_key) &&
746 fsid_key->ek_export &&
747 fsid_key->ek_export != exp)
748 goto finish;
749
750 if (exp) {
751 /* just a flags/id/fsid update */
752
753 exp_fsid_unhash(exp);
754 exp->ex_flags = nxp->ex_flags;
755 exp->ex_anon_uid = nxp->ex_anon_uid;
756 exp->ex_anon_gid = nxp->ex_anon_gid;
757 exp->ex_fsid = nxp->ex_dev;
758
759 err = exp_fsid_hash(clp, exp);
760 goto finish;
761 }
762
763 err = check_export(nd.dentry->d_inode, nxp->ex_flags);
764 if (err) goto finish;
765
766 err = -ENOMEM;
767
768 dprintk("nfsd: creating export entry %p for client %p\n", exp, clp);
769
770 new.h.expiry_time = NEVER;
771 new.h.flags = 0;
772 new.ex_client = clp;
773 new.ex_mnt = nd.mnt;
774 new.ex_dentry = nd.dentry;
775 new.ex_flags = nxp->ex_flags;
776 new.ex_anon_uid = nxp->ex_anon_uid;
777 new.ex_anon_gid = nxp->ex_anon_gid;
778 new.ex_fsid = nxp->ex_dev;
779
780 exp = svc_export_lookup(&new, 1);
781
782 if (exp == NULL)
783 goto finish;
784
785 err = 0;
786
787 if (exp_hash(clp, exp) ||
788 exp_fsid_hash(clp, exp)) {
789 /* failed to create at least one index */
790 exp_do_unexport(exp);
791 cache_flush();
792 err = -ENOMEM;
793 }
794
795finish:
796 if (exp)
797 exp_put(exp);
798 if (fsid_key && !IS_ERR(fsid_key))
799 expkey_put(&fsid_key->h, &svc_expkey_cache);
800 if (clp)
801 auth_domain_put(clp);
802 path_release(&nd);
803out_unlock:
804 exp_writeunlock();
805out:
806 return err;
807}
808
809/*
810 * Unexport a file system. The export entry has already
811 * been removed from the client's list of exported fs's.
812 */
813static void
814exp_do_unexport(svc_export *unexp)
815{
816 unexp->h.expiry_time = get_seconds()-1;
817 svc_export_cache.nextcheck = get_seconds();
818 exp_unhash(unexp);
819 exp_fsid_unhash(unexp);
820}
821
822
823/*
824 * unexport syscall.
825 */
826int
827exp_unexport(struct nfsctl_export *nxp)
828{
829 struct auth_domain *dom;
830 svc_export *exp;
831 struct nameidata nd;
832 int err;
833
834 /* Consistency check */
835 if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
836 !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
837 return -EINVAL;
838
839 exp_writelock();
840
841 err = -EINVAL;
842 dom = auth_domain_find(nxp->ex_client);
843 if (!dom) {
844 dprintk("nfsd: unexport couldn't find %s\n", nxp->ex_client);
845 goto out_unlock;
846 }
847
848 err = path_lookup(nxp->ex_path, 0, &nd);
849 if (err)
850 goto out_domain;
851
852 err = -EINVAL;
853 exp = exp_get_by_name(dom, nd.mnt, nd.dentry, NULL);
854 path_release(&nd);
855 if (!exp)
856 goto out_domain;
857
858 exp_do_unexport(exp);
859 exp_put(exp);
860 err = 0;
861
862out_domain:
863 auth_domain_put(dom);
864 cache_flush();
865out_unlock:
866 exp_writeunlock();
867 return err;
868}
869
870/*
871 * Obtain the root fh on behalf of a client.
872 * This could be done in user space, but I feel that it adds some safety
873 * since its harder to fool a kernel module than a user space program.
874 */
875int
876exp_rootfh(svc_client *clp, char *path, struct knfsd_fh *f, int maxsize)
877{
878 struct svc_export *exp;
879 struct nameidata nd;
880 struct inode *inode;
881 struct svc_fh fh;
882 int err;
883
884 err = -EPERM;
885 /* NB: we probably ought to check that it's NUL-terminated */
886 if (path_lookup(path, 0, &nd)) {
887 printk("nfsd: exp_rootfh path not found %s", path);
888 return err;
889 }
890 inode = nd.dentry->d_inode;
891
892 dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
893 path, nd.dentry, clp->name,
894 inode->i_sb->s_id, inode->i_ino);
895 exp = exp_parent(clp, nd.mnt, nd.dentry, NULL);
896 if (!exp) {
897 dprintk("nfsd: exp_rootfh export not found.\n");
898 goto out;
899 }
900
901 /*
902 * fh must be initialized before calling fh_compose
903 */
904 fh_init(&fh, maxsize);
905 if (fh_compose(&fh, exp, nd.dentry, NULL))
906 err = -EINVAL;
907 else
908 err = 0;
909 memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
910 fh_put(&fh);
911 exp_put(exp);
912out:
913 path_release(&nd);
914 return err;
915}
916
917/*
918 * Called when we need the filehandle for the root of the pseudofs,
919 * for a given NFSv4 client. The root is defined to be the
920 * export point with fsid==0
921 */
922int
923exp_pseudoroot(struct auth_domain *clp, struct svc_fh *fhp,
924 struct cache_req *creq)
925{
926 struct svc_expkey *fsid_key;
927 int rv;
928 u32 fsidv[2];
929
930 mk_fsid_v1(fsidv, 0);
931
932 fsid_key = exp_find_key(clp, 1, fsidv, creq);
933 if (IS_ERR(fsid_key) && PTR_ERR(fsid_key) == -EAGAIN)
934 return nfserr_dropit;
935 if (!fsid_key || IS_ERR(fsid_key))
936 return nfserr_perm;
937
938 rv = fh_compose(fhp, fsid_key->ek_export,
939 fsid_key->ek_export->ex_dentry, NULL);
940 expkey_put(&fsid_key->h, &svc_expkey_cache);
941 return rv;
942}
943
944/* Iterator */
945
946static void *e_start(struct seq_file *m, loff_t *pos)
947{
948 loff_t n = *pos;
949 unsigned hash, export;
950 struct cache_head *ch;
951
952 exp_readlock();
953 read_lock(&svc_export_cache.hash_lock);
954 if (!n--)
955 return (void *)1;
956 hash = n >> 32;
957 export = n & ((1LL<<32) - 1);
958
959
960 for (ch=export_table[hash]; ch; ch=ch->next)
961 if (!export--)
962 return ch;
963 n &= ~((1LL<<32) - 1);
964 do {
965 hash++;
966 n += 1LL<<32;
967 } while(hash < EXPORT_HASHMAX && export_table[hash]==NULL);
968 if (hash >= EXPORT_HASHMAX)
969 return NULL;
970 *pos = n+1;
971 return export_table[hash];
972}
973
974static void *e_next(struct seq_file *m, void *p, loff_t *pos)
975{
976 struct cache_head *ch = p;
977 int hash = (*pos >> 32);
978
979 if (p == (void *)1)
980 hash = 0;
981 else if (ch->next == NULL) {
982 hash++;
983 *pos += 1LL<<32;
984 } else {
985 ++*pos;
986 return ch->next;
987 }
988 *pos &= ~((1LL<<32) - 1);
989 while (hash < EXPORT_HASHMAX && export_table[hash] == NULL) {
990 hash++;
991 *pos += 1LL<<32;
992 }
993 if (hash >= EXPORT_HASHMAX)
994 return NULL;
995 ++*pos;
996 return export_table[hash];
997}
998
999static void e_stop(struct seq_file *m, void *p)
1000{
1001 read_unlock(&svc_export_cache.hash_lock);
1002 exp_readunlock();
1003}
1004
1005static struct flags {
1006 int flag;
1007 char *name[2];
1008} expflags[] = {
1009 { NFSEXP_READONLY, {"ro", "rw"}},
1010 { NFSEXP_INSECURE_PORT, {"insecure", ""}},
1011 { NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1012 { NFSEXP_ALLSQUASH, {"all_squash", ""}},
1013 { NFSEXP_ASYNC, {"async", "sync"}},
1014 { NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1015 { NFSEXP_NOHIDE, {"nohide", ""}},
1016 { NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1017 { NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1018 { NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1019#ifdef MSNFS
1020 { NFSEXP_MSNFS, {"msnfs", ""}},
1021#endif
1022 { 0, {"", ""}}
1023};
1024
1025static void exp_flags(struct seq_file *m, int flag, int fsid, uid_t anonu, uid_t anong)
1026{
1027 int first = 0;
1028 struct flags *flg;
1029
1030 for (flg = expflags; flg->flag; flg++) {
1031 int state = (flg->flag & flag)?0:1;
1032 if (*flg->name[state])
1033 seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1034 }
1035 if (flag & NFSEXP_FSID)
1036 seq_printf(m, "%sfsid=%d", first++?",":"", fsid);
1037 if (anonu != (uid_t)-2 && anonu != (0x10000-2))
1038 seq_printf(m, "%sanonuid=%d", first++?",":"", anonu);
1039 if (anong != (gid_t)-2 && anong != (0x10000-2))
1040 seq_printf(m, "%sanongid=%d", first++?",":"", anong);
1041}
1042
1043static int e_show(struct seq_file *m, void *p)
1044{
1045 struct cache_head *cp = p;
1046 struct svc_export *exp = container_of(cp, struct svc_export, h);
1047 svc_client *clp;
1048
1049 if (p == (void *)1) {
1050 seq_puts(m, "# Version 1.1\n");
1051 seq_puts(m, "# Path Client(Flags) # IPs\n");
1052 return 0;
1053 }
1054
1055 clp = exp->ex_client;
1056 cache_get(&exp->h);
1057 if (cache_check(&svc_export_cache, &exp->h, NULL))
1058 return 0;
1059 if (cache_put(&exp->h, &svc_export_cache)) BUG();
1060 return svc_export_show(m, &svc_export_cache, cp);
1061}
1062
1063struct seq_operations nfs_exports_op = {
1064 .start = e_start,
1065 .next = e_next,
1066 .stop = e_stop,
1067 .show = e_show,
1068};
1069
1070/*
1071 * Add or modify a client.
1072 * Change requests may involve the list of host addresses. The list of
1073 * exports and possibly existing uid maps are left untouched.
1074 */
1075int
1076exp_addclient(struct nfsctl_client *ncp)
1077{
1078 struct auth_domain *dom;
1079 int i, err;
1080
1081 /* First, consistency check. */
1082 err = -EINVAL;
1083 if (! exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
1084 goto out;
1085 if (ncp->cl_naddr > NFSCLNT_ADDRMAX)
1086 goto out;
1087
1088 /* Lock the hashtable */
1089 exp_writelock();
1090
1091 dom = unix_domain_find(ncp->cl_ident);
1092
1093 err = -ENOMEM;
1094 if (!dom)
1095 goto out_unlock;
1096
1097 /* Insert client into hashtable. */
1098 for (i = 0; i < ncp->cl_naddr; i++)
1099 auth_unix_add_addr(ncp->cl_addrlist[i], dom);
1100
1101 auth_unix_forget_old(dom);
1102 auth_domain_put(dom);
1103
1104 err = 0;
1105
1106out_unlock:
1107 exp_writeunlock();
1108out:
1109 return err;
1110}
1111
1112/*
1113 * Delete a client given an identifier.
1114 */
1115int
1116exp_delclient(struct nfsctl_client *ncp)
1117{
1118 int err;
1119 struct auth_domain *dom;
1120
1121 err = -EINVAL;
1122 if (!exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
1123 goto out;
1124
1125 /* Lock the hashtable */
1126 exp_writelock();
1127
1128 dom = auth_domain_find(ncp->cl_ident);
1129 /* just make sure that no addresses work
1130 * and that it will expire soon
1131 */
1132 if (dom) {
1133 err = auth_unix_forget_old(dom);
1134 dom->h.expiry_time = get_seconds();
1135 auth_domain_put(dom);
1136 }
1137
1138 exp_writeunlock();
1139out:
1140 return err;
1141}
1142
1143/*
1144 * Verify that string is non-empty and does not exceed max length.
1145 */
1146static int
1147exp_verify_string(char *cp, int max)
1148{
1149 int i;
1150
1151 for (i = 0; i < max; i++)
1152 if (!cp[i])
1153 return i;
1154 cp[i] = 0;
1155 printk(KERN_NOTICE "nfsd: couldn't validate string %s\n", cp);
1156 return 0;
1157}
1158
1159/*
1160 * Initialize the exports module.
1161 */
1162void
1163nfsd_export_init(void)
1164{
1165 dprintk("nfsd: initializing export module.\n");
1166
1167 cache_register(&svc_export_cache);
1168 cache_register(&svc_expkey_cache);
1169
1170}
1171
1172/*
1173 * Flush exports table - called when last nfsd thread is killed
1174 */
1175void
1176nfsd_export_flush(void)
1177{
1178 exp_writelock();
1179 cache_purge(&svc_expkey_cache);
1180 cache_purge(&svc_export_cache);
1181 exp_writeunlock();
1182}
1183
1184/*
1185 * Shutdown the exports module.
1186 */
1187void
1188nfsd_export_shutdown(void)
1189{
1190
1191 dprintk("nfsd: shutting down export module.\n");
1192
1193 exp_writelock();
1194
1195 if (cache_unregister(&svc_expkey_cache))
1196 printk(KERN_ERR "nfsd: failed to unregister expkey cache\n");
1197 if (cache_unregister(&svc_export_cache))
1198 printk(KERN_ERR "nfsd: failed to unregister export cache\n");
1199 svcauth_unix_purge();
1200
1201 exp_writeunlock();
1202 dprintk("nfsd: export shutdown complete.\n");
1203}