blob: 417ec02df44f33145504eabd72c940ea6efb3662 [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);
Jesper Juhlf99d49a2005-11-07 01:01:34 -0800193 kfree(buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 return err;
195}
196
197static int expkey_show(struct seq_file *m,
198 struct cache_detail *cd,
199 struct cache_head *h)
200{
201 struct svc_expkey *ek ;
202
203 if (h ==NULL) {
204 seq_puts(m, "#domain fsidtype fsid [path]\n");
205 return 0;
206 }
207 ek = container_of(h, struct svc_expkey, h);
208 seq_printf(m, "%s %d 0x%08x", ek->ek_client->name,
209 ek->ek_fsidtype, ek->ek_fsid[0]);
210 if (ek->ek_fsidtype != 1)
211 seq_printf(m, "%08x", ek->ek_fsid[1]);
212 if (ek->ek_fsidtype == 2)
213 seq_printf(m, "%08x", ek->ek_fsid[2]);
214 if (test_bit(CACHE_VALID, &h->flags) &&
215 !test_bit(CACHE_NEGATIVE, &h->flags)) {
216 seq_printf(m, " ");
217 seq_path(m, ek->ek_export->ex_mnt, ek->ek_export->ex_dentry, "\\ \t\n");
218 }
219 seq_printf(m, "\n");
220 return 0;
221}
222
223struct cache_detail svc_expkey_cache = {
Bruce Allanf35279d2005-09-06 15:17:08 -0700224 .owner = THIS_MODULE,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 .hash_size = EXPKEY_HASHMAX,
226 .hash_table = expkey_table,
227 .name = "nfsd.fh",
228 .cache_put = expkey_put,
229 .cache_request = expkey_request,
230 .cache_parse = expkey_parse,
231 .cache_show = expkey_show,
232};
233
234static inline int svc_expkey_match (struct svc_expkey *a, struct svc_expkey *b)
235{
236 if (a->ek_fsidtype != b->ek_fsidtype ||
237 a->ek_client != b->ek_client ||
238 memcmp(a->ek_fsid, b->ek_fsid, key_len(a->ek_fsidtype)) != 0)
239 return 0;
240 return 1;
241}
242
243static inline void svc_expkey_init(struct svc_expkey *new, struct svc_expkey *item)
244{
245 cache_get(&item->ek_client->h);
246 new->ek_client = item->ek_client;
247 new->ek_fsidtype = item->ek_fsidtype;
248 new->ek_fsid[0] = item->ek_fsid[0];
249 new->ek_fsid[1] = item->ek_fsid[1];
250 new->ek_fsid[2] = item->ek_fsid[2];
251}
252
253static inline void svc_expkey_update(struct svc_expkey *new, struct svc_expkey *item)
254{
255 cache_get(&item->ek_export->h);
256 new->ek_export = item->ek_export;
257}
258
259static DefineSimpleCacheLookup(svc_expkey,0) /* no inplace updates */
260
261#define EXPORT_HASHBITS 8
262#define EXPORT_HASHMAX (1<< EXPORT_HASHBITS)
263#define EXPORT_HASHMASK (EXPORT_HASHMAX -1)
264
265static struct cache_head *export_table[EXPORT_HASHMAX];
266
267static inline int svc_export_hash(struct svc_export *item)
268{
269 int rv;
270
271 rv = hash_ptr(item->ex_client, EXPORT_HASHBITS);
272 rv ^= hash_ptr(item->ex_dentry, EXPORT_HASHBITS);
273 rv ^= hash_ptr(item->ex_mnt, EXPORT_HASHBITS);
274 return rv;
275}
276
277void svc_export_put(struct cache_head *item, struct cache_detail *cd)
278{
279 if (cache_put(item, cd)) {
280 struct svc_export *exp = container_of(item, struct svc_export, h);
281 dput(exp->ex_dentry);
282 mntput(exp->ex_mnt);
283 auth_domain_put(exp->ex_client);
284 kfree(exp);
285 }
286}
287
288static void svc_export_request(struct cache_detail *cd,
289 struct cache_head *h,
290 char **bpp, int *blen)
291{
292 /* client path */
293 struct svc_export *exp = container_of(h, struct svc_export, h);
294 char *pth;
295
296 qword_add(bpp, blen, exp->ex_client->name);
297 pth = d_path(exp->ex_dentry, exp->ex_mnt, *bpp, *blen);
298 if (IS_ERR(pth)) {
299 /* is this correct? */
300 (*bpp)[0] = '\n';
301 return;
302 }
303 qword_add(bpp, blen, pth);
304 (*bpp)[-1] = '\n';
305}
306
307static struct svc_export *svc_export_lookup(struct svc_export *, int);
308
309static int check_export(struct inode *inode, int flags)
310{
311
312 /* We currently export only dirs and regular files.
313 * This is what umountd does.
314 */
315 if (!S_ISDIR(inode->i_mode) &&
316 !S_ISREG(inode->i_mode))
317 return -ENOTDIR;
318
319 /* There are two requirements on a filesystem to be exportable.
320 * 1: We must be able to identify the filesystem from a number.
321 * either a device number (so FS_REQUIRES_DEV needed)
322 * or an FSID number (so NFSEXP_FSID needed).
323 * 2: We must be able to find an inode from a filehandle.
324 * This means that s_export_op must be set.
325 */
326 if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
327 !(flags & NFSEXP_FSID)) {
328 dprintk("exp_export: export of non-dev fs without fsid");
329 return -EINVAL;
330 }
331 if (!inode->i_sb->s_export_op) {
332 dprintk("exp_export: export of invalid fs type.\n");
333 return -EINVAL;
334 }
335
336 /* Ok, we can export it */;
337 if (!inode->i_sb->s_export_op->find_exported_dentry)
338 inode->i_sb->s_export_op->find_exported_dentry =
339 find_exported_dentry;
340 return 0;
341
342}
343
344static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
345{
346 /* client path expiry [flags anonuid anongid fsid] */
347 char *buf;
348 int len;
349 int err;
350 struct auth_domain *dom = NULL;
351 struct nameidata nd;
352 struct svc_export exp, *expp;
353 int an_int;
354
355 nd.dentry = NULL;
356
357 if (mesg[mlen-1] != '\n')
358 return -EINVAL;
359 mesg[mlen-1] = 0;
360
361 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
362 err = -ENOMEM;
363 if (!buf) goto out;
364
365 /* client */
366 len = qword_get(&mesg, buf, PAGE_SIZE);
367 err = -EINVAL;
368 if (len <= 0) goto out;
369
370 err = -ENOENT;
371 dom = auth_domain_find(buf);
372 if (!dom)
373 goto out;
374
375 /* path */
376 err = -EINVAL;
377 if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
378 goto out;
379 err = path_lookup(buf, 0, &nd);
380 if (err) goto out;
381
382 exp.h.flags = 0;
383 exp.ex_client = dom;
384 exp.ex_mnt = nd.mnt;
385 exp.ex_dentry = nd.dentry;
386
387 /* expiry */
388 err = -EINVAL;
389 exp.h.expiry_time = get_expiry(&mesg);
390 if (exp.h.expiry_time == 0)
391 goto out;
392
393 /* flags */
394 err = get_int(&mesg, &an_int);
395 if (err == -ENOENT)
396 set_bit(CACHE_NEGATIVE, &exp.h.flags);
397 else {
398 if (err || an_int < 0) goto out;
399 exp.ex_flags= an_int;
400
401 /* anon uid */
402 err = get_int(&mesg, &an_int);
403 if (err) goto out;
404 exp.ex_anon_uid= an_int;
405
406 /* anon gid */
407 err = get_int(&mesg, &an_int);
408 if (err) goto out;
409 exp.ex_anon_gid= an_int;
410
411 /* fsid */
412 err = get_int(&mesg, &an_int);
413 if (err) goto out;
414 exp.ex_fsid = an_int;
415
416 err = check_export(nd.dentry->d_inode, exp.ex_flags);
417 if (err) goto out;
418 }
419
420 expp = svc_export_lookup(&exp, 1);
421 if (expp)
422 exp_put(expp);
423 err = 0;
424 cache_flush();
425 out:
426 if (nd.dentry)
427 path_release(&nd);
428 if (dom)
429 auth_domain_put(dom);
Jesper Juhlf99d49a2005-11-07 01:01:34 -0800430 kfree(buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 return err;
432}
433
434static void exp_flags(struct seq_file *m, int flag, int fsid, uid_t anonu, uid_t anong);
435
436static int svc_export_show(struct seq_file *m,
437 struct cache_detail *cd,
438 struct cache_head *h)
439{
440 struct svc_export *exp ;
441
442 if (h ==NULL) {
443 seq_puts(m, "#path domain(flags)\n");
444 return 0;
445 }
446 exp = container_of(h, struct svc_export, h);
447 seq_path(m, exp->ex_mnt, exp->ex_dentry, " \t\n\\");
448 seq_putc(m, '\t');
449 seq_escape(m, exp->ex_client->name, " \t\n\\");
450 seq_putc(m, '(');
451 if (test_bit(CACHE_VALID, &h->flags) &&
452 !test_bit(CACHE_NEGATIVE, &h->flags))
453 exp_flags(m, exp->ex_flags, exp->ex_fsid,
454 exp->ex_anon_uid, exp->ex_anon_gid);
455 seq_puts(m, ")\n");
456 return 0;
457}
458struct cache_detail svc_export_cache = {
Bruce Allanf35279d2005-09-06 15:17:08 -0700459 .owner = THIS_MODULE,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 .hash_size = EXPORT_HASHMAX,
461 .hash_table = export_table,
462 .name = "nfsd.export",
463 .cache_put = svc_export_put,
464 .cache_request = svc_export_request,
465 .cache_parse = svc_export_parse,
466 .cache_show = svc_export_show,
467};
468
469static inline int svc_export_match(struct svc_export *a, struct svc_export *b)
470{
471 return a->ex_client == b->ex_client &&
472 a->ex_dentry == b->ex_dentry &&
473 a->ex_mnt == b->ex_mnt;
474}
475static inline void svc_export_init(struct svc_export *new, struct svc_export *item)
476{
477 cache_get(&item->ex_client->h);
478 new->ex_client = item->ex_client;
479 new->ex_dentry = dget(item->ex_dentry);
480 new->ex_mnt = mntget(item->ex_mnt);
481}
482
483static inline void svc_export_update(struct svc_export *new, struct svc_export *item)
484{
485 new->ex_flags = item->ex_flags;
486 new->ex_anon_uid = item->ex_anon_uid;
487 new->ex_anon_gid = item->ex_anon_gid;
488 new->ex_fsid = item->ex_fsid;
489}
490
491static DefineSimpleCacheLookup(svc_export,1) /* allow inplace updates */
492
493
494struct svc_expkey *
495exp_find_key(svc_client *clp, int fsid_type, u32 *fsidv, struct cache_req *reqp)
496{
497 struct svc_expkey key, *ek;
498 int err;
499
500 if (!clp)
501 return NULL;
502
503 key.ek_client = clp;
504 key.ek_fsidtype = fsid_type;
505 memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
506
507 ek = svc_expkey_lookup(&key, 0);
508 if (ek != NULL)
509 if ((err = cache_check(&svc_expkey_cache, &ek->h, reqp)))
510 ek = ERR_PTR(err);
511 return ek;
512}
513
514static int exp_set_key(svc_client *clp, int fsid_type, u32 *fsidv,
515 struct svc_export *exp)
516{
517 struct svc_expkey key, *ek;
518
519 key.ek_client = clp;
520 key.ek_fsidtype = fsid_type;
521 memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
522 key.ek_export = exp;
523 key.h.expiry_time = NEVER;
524 key.h.flags = 0;
525
526 ek = svc_expkey_lookup(&key, 1);
527 if (ek) {
528 expkey_put(&ek->h, &svc_expkey_cache);
529 return 0;
530 }
531 return -ENOMEM;
532}
533
534/*
535 * Find the client's export entry matching xdev/xino.
536 */
537static inline struct svc_expkey *
538exp_get_key(svc_client *clp, dev_t dev, ino_t ino)
539{
540 u32 fsidv[3];
541
542 if (old_valid_dev(dev)) {
543 mk_fsid_v0(fsidv, dev, ino);
544 return exp_find_key(clp, 0, fsidv, NULL);
545 }
546 mk_fsid_v3(fsidv, dev, ino);
547 return exp_find_key(clp, 3, fsidv, NULL);
548}
549
550/*
551 * Find the client's export entry matching fsid
552 */
553static inline struct svc_expkey *
554exp_get_fsid_key(svc_client *clp, int fsid)
555{
556 u32 fsidv[2];
557
558 mk_fsid_v1(fsidv, fsid);
559
560 return exp_find_key(clp, 1, fsidv, NULL);
561}
562
563svc_export *
564exp_get_by_name(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
565 struct cache_req *reqp)
566{
567 struct svc_export *exp, key;
568
569 if (!clp)
570 return NULL;
571
572 key.ex_client = clp;
573 key.ex_mnt = mnt;
574 key.ex_dentry = dentry;
575
576 exp = svc_export_lookup(&key, 0);
577 if (exp != NULL)
578 switch (cache_check(&svc_export_cache, &exp->h, reqp)) {
579 case 0: break;
580 case -EAGAIN:
581 exp = ERR_PTR(-EAGAIN);
582 break;
583 default:
584 exp = NULL;
585 }
586
587 return exp;
588}
589
590/*
591 * Find the export entry for a given dentry.
592 */
593struct svc_export *
594exp_parent(svc_client *clp, struct vfsmount *mnt, struct dentry *dentry,
595 struct cache_req *reqp)
596{
597 svc_export *exp;
598
599 dget(dentry);
600 exp = exp_get_by_name(clp, mnt, dentry, reqp);
601
602 while (exp == NULL && !IS_ROOT(dentry)) {
603 struct dentry *parent;
604
605 parent = dget_parent(dentry);
606 dput(dentry);
607 dentry = parent;
608 exp = exp_get_by_name(clp, mnt, dentry, reqp);
609 }
610 dput(dentry);
611 return exp;
612}
613
614/*
615 * Hashtable locking. Write locks are placed only by user processes
616 * wanting to modify export information.
617 * Write locking only done in this file. Read locking
618 * needed externally.
619 */
620
621static DECLARE_RWSEM(hash_sem);
622
623void
624exp_readlock(void)
625{
626 down_read(&hash_sem);
627}
628
629static inline void
630exp_writelock(void)
631{
632 down_write(&hash_sem);
633}
634
635void
636exp_readunlock(void)
637{
638 up_read(&hash_sem);
639}
640
641static inline void
642exp_writeunlock(void)
643{
644 up_write(&hash_sem);
645}
646
647static void exp_fsid_unhash(struct svc_export *exp)
648{
649 struct svc_expkey *ek;
650
651 if ((exp->ex_flags & NFSEXP_FSID) == 0)
652 return;
653
654 ek = exp_get_fsid_key(exp->ex_client, exp->ex_fsid);
655 if (ek && !IS_ERR(ek)) {
656 ek->h.expiry_time = get_seconds()-1;
657 expkey_put(&ek->h, &svc_expkey_cache);
658 }
659 svc_expkey_cache.nextcheck = get_seconds();
660}
661
662static int exp_fsid_hash(svc_client *clp, struct svc_export *exp)
663{
664 u32 fsid[2];
665
666 if ((exp->ex_flags & NFSEXP_FSID) == 0)
667 return 0;
668
669 mk_fsid_v1(fsid, exp->ex_fsid);
670 return exp_set_key(clp, 1, fsid, exp);
671}
672
673static int exp_hash(struct auth_domain *clp, struct svc_export *exp)
674{
675 u32 fsid[2];
676 struct inode *inode = exp->ex_dentry->d_inode;
677 dev_t dev = inode->i_sb->s_dev;
678
679 if (old_valid_dev(dev)) {
680 mk_fsid_v0(fsid, dev, inode->i_ino);
681 return exp_set_key(clp, 0, fsid, exp);
682 }
683 mk_fsid_v3(fsid, dev, inode->i_ino);
684 return exp_set_key(clp, 3, fsid, exp);
685}
686
687static void exp_unhash(struct svc_export *exp)
688{
689 struct svc_expkey *ek;
690 struct inode *inode = exp->ex_dentry->d_inode;
691
692 ek = exp_get_key(exp->ex_client, inode->i_sb->s_dev, inode->i_ino);
693 if (ek && !IS_ERR(ek)) {
694 ek->h.expiry_time = get_seconds()-1;
695 expkey_put(&ek->h, &svc_expkey_cache);
696 }
697 svc_expkey_cache.nextcheck = get_seconds();
698}
699
700/*
701 * Export a file system.
702 */
703int
704exp_export(struct nfsctl_export *nxp)
705{
706 svc_client *clp;
707 struct svc_export *exp = NULL;
708 struct svc_export new;
709 struct svc_expkey *fsid_key = NULL;
710 struct nameidata nd;
711 int err;
712
713 /* Consistency check */
714 err = -EINVAL;
715 if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
716 !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
717 goto out;
718
719 dprintk("exp_export called for %s:%s (%x/%ld fl %x).\n",
720 nxp->ex_client, nxp->ex_path,
721 (unsigned)nxp->ex_dev, (long)nxp->ex_ino,
722 nxp->ex_flags);
723
724 /* Try to lock the export table for update */
725 exp_writelock();
726
727 /* Look up client info */
728 if (!(clp = auth_domain_find(nxp->ex_client)))
729 goto out_unlock;
730
731
732 /* Look up the dentry */
733 err = path_lookup(nxp->ex_path, 0, &nd);
734 if (err)
735 goto out_unlock;
736 err = -EINVAL;
737
738 exp = exp_get_by_name(clp, nd.mnt, nd.dentry, NULL);
739
740 /* must make sure there won't be an ex_fsid clash */
741 if ((nxp->ex_flags & NFSEXP_FSID) &&
742 (fsid_key = exp_get_fsid_key(clp, nxp->ex_dev)) &&
743 !IS_ERR(fsid_key) &&
744 fsid_key->ek_export &&
745 fsid_key->ek_export != exp)
746 goto finish;
747
748 if (exp) {
749 /* just a flags/id/fsid update */
750
751 exp_fsid_unhash(exp);
752 exp->ex_flags = nxp->ex_flags;
753 exp->ex_anon_uid = nxp->ex_anon_uid;
754 exp->ex_anon_gid = nxp->ex_anon_gid;
755 exp->ex_fsid = nxp->ex_dev;
756
757 err = exp_fsid_hash(clp, exp);
758 goto finish;
759 }
760
761 err = check_export(nd.dentry->d_inode, nxp->ex_flags);
762 if (err) goto finish;
763
764 err = -ENOMEM;
765
766 dprintk("nfsd: creating export entry %p for client %p\n", exp, clp);
767
768 new.h.expiry_time = NEVER;
769 new.h.flags = 0;
770 new.ex_client = clp;
771 new.ex_mnt = nd.mnt;
772 new.ex_dentry = nd.dentry;
773 new.ex_flags = nxp->ex_flags;
774 new.ex_anon_uid = nxp->ex_anon_uid;
775 new.ex_anon_gid = nxp->ex_anon_gid;
776 new.ex_fsid = nxp->ex_dev;
777
778 exp = svc_export_lookup(&new, 1);
779
780 if (exp == NULL)
781 goto finish;
782
783 err = 0;
784
785 if (exp_hash(clp, exp) ||
786 exp_fsid_hash(clp, exp)) {
787 /* failed to create at least one index */
788 exp_do_unexport(exp);
789 cache_flush();
790 err = -ENOMEM;
791 }
792
793finish:
794 if (exp)
795 exp_put(exp);
796 if (fsid_key && !IS_ERR(fsid_key))
797 expkey_put(&fsid_key->h, &svc_expkey_cache);
798 if (clp)
799 auth_domain_put(clp);
800 path_release(&nd);
801out_unlock:
802 exp_writeunlock();
803out:
804 return err;
805}
806
807/*
808 * Unexport a file system. The export entry has already
809 * been removed from the client's list of exported fs's.
810 */
811static void
812exp_do_unexport(svc_export *unexp)
813{
814 unexp->h.expiry_time = get_seconds()-1;
815 svc_export_cache.nextcheck = get_seconds();
816 exp_unhash(unexp);
817 exp_fsid_unhash(unexp);
818}
819
820
821/*
822 * unexport syscall.
823 */
824int
825exp_unexport(struct nfsctl_export *nxp)
826{
827 struct auth_domain *dom;
828 svc_export *exp;
829 struct nameidata nd;
830 int err;
831
832 /* Consistency check */
833 if (!exp_verify_string(nxp->ex_path, NFS_MAXPATHLEN) ||
834 !exp_verify_string(nxp->ex_client, NFSCLNT_IDMAX))
835 return -EINVAL;
836
837 exp_writelock();
838
839 err = -EINVAL;
840 dom = auth_domain_find(nxp->ex_client);
841 if (!dom) {
842 dprintk("nfsd: unexport couldn't find %s\n", nxp->ex_client);
843 goto out_unlock;
844 }
845
846 err = path_lookup(nxp->ex_path, 0, &nd);
847 if (err)
848 goto out_domain;
849
850 err = -EINVAL;
851 exp = exp_get_by_name(dom, nd.mnt, nd.dentry, NULL);
852 path_release(&nd);
853 if (!exp)
854 goto out_domain;
855
856 exp_do_unexport(exp);
857 exp_put(exp);
858 err = 0;
859
860out_domain:
861 auth_domain_put(dom);
862 cache_flush();
863out_unlock:
864 exp_writeunlock();
865 return err;
866}
867
868/*
869 * Obtain the root fh on behalf of a client.
870 * This could be done in user space, but I feel that it adds some safety
871 * since its harder to fool a kernel module than a user space program.
872 */
873int
874exp_rootfh(svc_client *clp, char *path, struct knfsd_fh *f, int maxsize)
875{
876 struct svc_export *exp;
877 struct nameidata nd;
878 struct inode *inode;
879 struct svc_fh fh;
880 int err;
881
882 err = -EPERM;
883 /* NB: we probably ought to check that it's NUL-terminated */
884 if (path_lookup(path, 0, &nd)) {
885 printk("nfsd: exp_rootfh path not found %s", path);
886 return err;
887 }
888 inode = nd.dentry->d_inode;
889
890 dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
891 path, nd.dentry, clp->name,
892 inode->i_sb->s_id, inode->i_ino);
893 exp = exp_parent(clp, nd.mnt, nd.dentry, NULL);
894 if (!exp) {
895 dprintk("nfsd: exp_rootfh export not found.\n");
896 goto out;
897 }
898
899 /*
900 * fh must be initialized before calling fh_compose
901 */
902 fh_init(&fh, maxsize);
903 if (fh_compose(&fh, exp, nd.dentry, NULL))
904 err = -EINVAL;
905 else
906 err = 0;
907 memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
908 fh_put(&fh);
909 exp_put(exp);
910out:
911 path_release(&nd);
912 return err;
913}
914
915/*
916 * Called when we need the filehandle for the root of the pseudofs,
917 * for a given NFSv4 client. The root is defined to be the
918 * export point with fsid==0
919 */
920int
921exp_pseudoroot(struct auth_domain *clp, struct svc_fh *fhp,
922 struct cache_req *creq)
923{
924 struct svc_expkey *fsid_key;
925 int rv;
926 u32 fsidv[2];
927
928 mk_fsid_v1(fsidv, 0);
929
930 fsid_key = exp_find_key(clp, 1, fsidv, creq);
931 if (IS_ERR(fsid_key) && PTR_ERR(fsid_key) == -EAGAIN)
932 return nfserr_dropit;
933 if (!fsid_key || IS_ERR(fsid_key))
934 return nfserr_perm;
935
936 rv = fh_compose(fhp, fsid_key->ek_export,
937 fsid_key->ek_export->ex_dentry, NULL);
938 expkey_put(&fsid_key->h, &svc_expkey_cache);
939 return rv;
940}
941
942/* Iterator */
943
944static void *e_start(struct seq_file *m, loff_t *pos)
945{
946 loff_t n = *pos;
947 unsigned hash, export;
948 struct cache_head *ch;
949
950 exp_readlock();
951 read_lock(&svc_export_cache.hash_lock);
952 if (!n--)
953 return (void *)1;
954 hash = n >> 32;
955 export = n & ((1LL<<32) - 1);
956
957
958 for (ch=export_table[hash]; ch; ch=ch->next)
959 if (!export--)
960 return ch;
961 n &= ~((1LL<<32) - 1);
962 do {
963 hash++;
964 n += 1LL<<32;
965 } while(hash < EXPORT_HASHMAX && export_table[hash]==NULL);
966 if (hash >= EXPORT_HASHMAX)
967 return NULL;
968 *pos = n+1;
969 return export_table[hash];
970}
971
972static void *e_next(struct seq_file *m, void *p, loff_t *pos)
973{
974 struct cache_head *ch = p;
975 int hash = (*pos >> 32);
976
977 if (p == (void *)1)
978 hash = 0;
979 else if (ch->next == NULL) {
980 hash++;
981 *pos += 1LL<<32;
982 } else {
983 ++*pos;
984 return ch->next;
985 }
986 *pos &= ~((1LL<<32) - 1);
987 while (hash < EXPORT_HASHMAX && export_table[hash] == NULL) {
988 hash++;
989 *pos += 1LL<<32;
990 }
991 if (hash >= EXPORT_HASHMAX)
992 return NULL;
993 ++*pos;
994 return export_table[hash];
995}
996
997static void e_stop(struct seq_file *m, void *p)
998{
999 read_unlock(&svc_export_cache.hash_lock);
1000 exp_readunlock();
1001}
1002
1003static struct flags {
1004 int flag;
1005 char *name[2];
1006} expflags[] = {
1007 { NFSEXP_READONLY, {"ro", "rw"}},
1008 { NFSEXP_INSECURE_PORT, {"insecure", ""}},
1009 { NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1010 { NFSEXP_ALLSQUASH, {"all_squash", ""}},
1011 { NFSEXP_ASYNC, {"async", "sync"}},
1012 { NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1013 { NFSEXP_NOHIDE, {"nohide", ""}},
1014 { NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1015 { NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1016 { NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1017#ifdef MSNFS
1018 { NFSEXP_MSNFS, {"msnfs", ""}},
1019#endif
1020 { 0, {"", ""}}
1021};
1022
1023static void exp_flags(struct seq_file *m, int flag, int fsid, uid_t anonu, uid_t anong)
1024{
1025 int first = 0;
1026 struct flags *flg;
1027
1028 for (flg = expflags; flg->flag; flg++) {
1029 int state = (flg->flag & flag)?0:1;
1030 if (*flg->name[state])
1031 seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1032 }
1033 if (flag & NFSEXP_FSID)
1034 seq_printf(m, "%sfsid=%d", first++?",":"", fsid);
1035 if (anonu != (uid_t)-2 && anonu != (0x10000-2))
1036 seq_printf(m, "%sanonuid=%d", first++?",":"", anonu);
1037 if (anong != (gid_t)-2 && anong != (0x10000-2))
1038 seq_printf(m, "%sanongid=%d", first++?",":"", anong);
1039}
1040
1041static int e_show(struct seq_file *m, void *p)
1042{
1043 struct cache_head *cp = p;
1044 struct svc_export *exp = container_of(cp, struct svc_export, h);
1045 svc_client *clp;
1046
1047 if (p == (void *)1) {
1048 seq_puts(m, "# Version 1.1\n");
1049 seq_puts(m, "# Path Client(Flags) # IPs\n");
1050 return 0;
1051 }
1052
1053 clp = exp->ex_client;
1054 cache_get(&exp->h);
1055 if (cache_check(&svc_export_cache, &exp->h, NULL))
1056 return 0;
1057 if (cache_put(&exp->h, &svc_export_cache)) BUG();
1058 return svc_export_show(m, &svc_export_cache, cp);
1059}
1060
1061struct seq_operations nfs_exports_op = {
1062 .start = e_start,
1063 .next = e_next,
1064 .stop = e_stop,
1065 .show = e_show,
1066};
1067
1068/*
1069 * Add or modify a client.
1070 * Change requests may involve the list of host addresses. The list of
1071 * exports and possibly existing uid maps are left untouched.
1072 */
1073int
1074exp_addclient(struct nfsctl_client *ncp)
1075{
1076 struct auth_domain *dom;
1077 int i, err;
1078
1079 /* First, consistency check. */
1080 err = -EINVAL;
1081 if (! exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
1082 goto out;
1083 if (ncp->cl_naddr > NFSCLNT_ADDRMAX)
1084 goto out;
1085
1086 /* Lock the hashtable */
1087 exp_writelock();
1088
1089 dom = unix_domain_find(ncp->cl_ident);
1090
1091 err = -ENOMEM;
1092 if (!dom)
1093 goto out_unlock;
1094
1095 /* Insert client into hashtable. */
1096 for (i = 0; i < ncp->cl_naddr; i++)
1097 auth_unix_add_addr(ncp->cl_addrlist[i], dom);
1098
1099 auth_unix_forget_old(dom);
1100 auth_domain_put(dom);
1101
1102 err = 0;
1103
1104out_unlock:
1105 exp_writeunlock();
1106out:
1107 return err;
1108}
1109
1110/*
1111 * Delete a client given an identifier.
1112 */
1113int
1114exp_delclient(struct nfsctl_client *ncp)
1115{
1116 int err;
1117 struct auth_domain *dom;
1118
1119 err = -EINVAL;
1120 if (!exp_verify_string(ncp->cl_ident, NFSCLNT_IDMAX))
1121 goto out;
1122
1123 /* Lock the hashtable */
1124 exp_writelock();
1125
1126 dom = auth_domain_find(ncp->cl_ident);
1127 /* just make sure that no addresses work
1128 * and that it will expire soon
1129 */
1130 if (dom) {
1131 err = auth_unix_forget_old(dom);
1132 dom->h.expiry_time = get_seconds();
1133 auth_domain_put(dom);
1134 }
1135
1136 exp_writeunlock();
1137out:
1138 return err;
1139}
1140
1141/*
1142 * Verify that string is non-empty and does not exceed max length.
1143 */
1144static int
1145exp_verify_string(char *cp, int max)
1146{
1147 int i;
1148
1149 for (i = 0; i < max; i++)
1150 if (!cp[i])
1151 return i;
1152 cp[i] = 0;
1153 printk(KERN_NOTICE "nfsd: couldn't validate string %s\n", cp);
1154 return 0;
1155}
1156
1157/*
1158 * Initialize the exports module.
1159 */
1160void
1161nfsd_export_init(void)
1162{
1163 dprintk("nfsd: initializing export module.\n");
1164
1165 cache_register(&svc_export_cache);
1166 cache_register(&svc_expkey_cache);
1167
1168}
1169
1170/*
1171 * Flush exports table - called when last nfsd thread is killed
1172 */
1173void
1174nfsd_export_flush(void)
1175{
1176 exp_writelock();
1177 cache_purge(&svc_expkey_cache);
1178 cache_purge(&svc_export_cache);
1179 exp_writeunlock();
1180}
1181
1182/*
1183 * Shutdown the exports module.
1184 */
1185void
1186nfsd_export_shutdown(void)
1187{
1188
1189 dprintk("nfsd: shutting down export module.\n");
1190
1191 exp_writelock();
1192
1193 if (cache_unregister(&svc_expkey_cache))
1194 printk(KERN_ERR "nfsd: failed to unregister expkey cache\n");
1195 if (cache_unregister(&svc_export_cache))
1196 printk(KERN_ERR "nfsd: failed to unregister export cache\n");
1197 svcauth_unix_purge();
1198
1199 exp_writeunlock();
1200 dprintk("nfsd: export shutdown complete.\n");
1201}