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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * NFS exporting and validation.
4 *
5 * We maintain a list of clients, each of which has a list of
6 * exports. To export an fs to a given client, you first have
7 * to create the client entry with NFSCTL_ADDCLIENT, which
8 * creates a client control block and adds it to the hash
9 * table. Then, you call NFSCTL_EXPORT for each fs.
10 *
11 *
12 * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
13 */
14
15 #include <linux/slab.h>
16 #include <linux/namei.h>
17 #include <linux/module.h>
18 #include <linux/exportfs.h>
19 #include <linux/sunrpc/svc_xprt.h>
20
21 #include "nfsd.h"
22 #include "nfsfh.h"
23 #include "netns.h"
24 #include "pnfs.h"
25 #include "filecache.h"
26 #include "trace.h"
27
28 #define NFSDDBG_FACILITY NFSDDBG_EXPORT
29
30 /*
31 * We have two caches.
32 * One maps client+vfsmnt+dentry to export options - the export map
33 * The other maps client+filehandle-fragment to export options. - the expkey map
34 *
35 * The export options are actually stored in the first map, and the
36 * second map contains a reference to the entry in the first map.
37 */
38
39 #define EXPKEY_HASHBITS 8
40 #define EXPKEY_HASHMAX (1 << EXPKEY_HASHBITS)
41 #define EXPKEY_HASHMASK (EXPKEY_HASHMAX -1)
42
43 static void expkey_put(struct kref *ref)
44 {
45 struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
46
47 if (test_bit(CACHE_VALID, &key->h.flags) &&
48 !test_bit(CACHE_NEGATIVE, &key->h.flags))
49 path_put(&key->ek_path);
50 auth_domain_put(key->ek_client);
51 kfree_rcu(key, ek_rcu);
52 }
53
54 static int expkey_upcall(struct cache_detail *cd, struct cache_head *h)
55 {
56 return sunrpc_cache_pipe_upcall(cd, h);
57 }
58
59 static void expkey_request(struct cache_detail *cd,
60 struct cache_head *h,
61 char **bpp, int *blen)
62 {
63 /* client fsidtype \xfsid */
64 struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
65 char type[5];
66
67 qword_add(bpp, blen, ek->ek_client->name);
68 snprintf(type, 5, "%d", ek->ek_fsidtype);
69 qword_add(bpp, blen, type);
70 qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
71 (*bpp)[-1] = '\n';
72 }
73
74 static struct svc_expkey *svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
75 struct svc_expkey *old);
76 static struct svc_expkey *svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *);
77
78 static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
79 {
80 /* client fsidtype fsid expiry [path] */
81 char *buf;
82 int len;
83 struct auth_domain *dom = NULL;
84 int err;
85 int fsidtype;
86 char *ep;
87 struct svc_expkey key;
88 struct svc_expkey *ek = NULL;
89
90 if (mesg[mlen - 1] != '\n')
91 return -EINVAL;
92 mesg[mlen-1] = 0;
93
94 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
95 err = -ENOMEM;
96 if (!buf)
97 goto out;
98
99 err = -EINVAL;
100 if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
101 goto out;
102
103 err = -ENOENT;
104 dom = auth_domain_find(buf);
105 if (!dom)
106 goto out;
107 dprintk("found domain %s\n", buf);
108
109 err = -EINVAL;
110 if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
111 goto out;
112 fsidtype = simple_strtoul(buf, &ep, 10);
113 if (*ep)
114 goto out;
115 dprintk("found fsidtype %d\n", fsidtype);
116 if (key_len(fsidtype)==0) /* invalid type */
117 goto out;
118 if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
119 goto out;
120 dprintk("found fsid length %d\n", len);
121 if (len != key_len(fsidtype))
122 goto out;
123
124 /* OK, we seem to have a valid key */
125 key.h.flags = 0;
126 key.h.expiry_time = get_expiry(&mesg);
127 if (key.h.expiry_time == 0)
128 goto out;
129
130 key.ek_client = dom;
131 key.ek_fsidtype = fsidtype;
132 memcpy(key.ek_fsid, buf, len);
133
134 ek = svc_expkey_lookup(cd, &key);
135 err = -ENOMEM;
136 if (!ek)
137 goto out;
138
139 /* now we want a pathname, or empty meaning NEGATIVE */
140 err = -EINVAL;
141 len = qword_get(&mesg, buf, PAGE_SIZE);
142 if (len < 0)
143 goto out;
144 dprintk("Path seems to be <%s>\n", buf);
145 err = 0;
146 if (len == 0) {
147 set_bit(CACHE_NEGATIVE, &key.h.flags);
148 ek = svc_expkey_update(cd, &key, ek);
149 if (ek)
150 trace_nfsd_expkey_update(ek, NULL);
151 else
152 err = -ENOMEM;
153 } else {
154 err = kern_path(buf, 0, &key.ek_path);
155 if (err)
156 goto out;
157
158 dprintk("Found the path %s\n", buf);
159
160 ek = svc_expkey_update(cd, &key, ek);
161 if (ek)
162 trace_nfsd_expkey_update(ek, buf);
163 else
164 err = -ENOMEM;
165 path_put(&key.ek_path);
166 }
167 cache_flush();
168 out:
169 if (ek)
170 cache_put(&ek->h, cd);
171 if (dom)
172 auth_domain_put(dom);
173 kfree(buf);
174 return err;
175 }
176
177 static int expkey_show(struct seq_file *m,
178 struct cache_detail *cd,
179 struct cache_head *h)
180 {
181 struct svc_expkey *ek ;
182 int i;
183
184 if (h ==NULL) {
185 seq_puts(m, "#domain fsidtype fsid [path]\n");
186 return 0;
187 }
188 ek = container_of(h, struct svc_expkey, h);
189 seq_printf(m, "%s %d 0x", ek->ek_client->name,
190 ek->ek_fsidtype);
191 for (i=0; i < key_len(ek->ek_fsidtype)/4; i++)
192 seq_printf(m, "%08x", ek->ek_fsid[i]);
193 if (test_bit(CACHE_VALID, &h->flags) &&
194 !test_bit(CACHE_NEGATIVE, &h->flags)) {
195 seq_printf(m, " ");
196 seq_path(m, &ek->ek_path, "\\ \t\n");
197 }
198 seq_printf(m, "\n");
199 return 0;
200 }
201
202 static inline int expkey_match (struct cache_head *a, struct cache_head *b)
203 {
204 struct svc_expkey *orig = container_of(a, struct svc_expkey, h);
205 struct svc_expkey *new = container_of(b, struct svc_expkey, h);
206
207 if (orig->ek_fsidtype != new->ek_fsidtype ||
208 orig->ek_client != new->ek_client ||
209 memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0)
210 return 0;
211 return 1;
212 }
213
214 static inline void expkey_init(struct cache_head *cnew,
215 struct cache_head *citem)
216 {
217 struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
218 struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
219
220 kref_get(&item->ek_client->ref);
221 new->ek_client = item->ek_client;
222 new->ek_fsidtype = item->ek_fsidtype;
223
224 memcpy(new->ek_fsid, item->ek_fsid, sizeof(new->ek_fsid));
225 }
226
227 static inline void expkey_update(struct cache_head *cnew,
228 struct cache_head *citem)
229 {
230 struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
231 struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
232
233 new->ek_path = item->ek_path;
234 path_get(&item->ek_path);
235 }
236
237 static struct cache_head *expkey_alloc(void)
238 {
239 struct svc_expkey *i = kmalloc(sizeof(*i), GFP_KERNEL);
240 if (i)
241 return &i->h;
242 else
243 return NULL;
244 }
245
246 static void expkey_flush(void)
247 {
248 /*
249 * Take the nfsd_mutex here to ensure that the file cache is not
250 * destroyed while we're in the middle of flushing.
251 */
252 mutex_lock(&nfsd_mutex);
253 nfsd_file_cache_purge(current->nsproxy->net_ns);
254 mutex_unlock(&nfsd_mutex);
255 }
256
257 static const struct cache_detail svc_expkey_cache_template = {
258 .owner = THIS_MODULE,
259 .hash_size = EXPKEY_HASHMAX,
260 .name = "nfsd.fh",
261 .cache_put = expkey_put,
262 .cache_upcall = expkey_upcall,
263 .cache_request = expkey_request,
264 .cache_parse = expkey_parse,
265 .cache_show = expkey_show,
266 .match = expkey_match,
267 .init = expkey_init,
268 .update = expkey_update,
269 .alloc = expkey_alloc,
270 .flush = expkey_flush,
271 };
272
273 static int
274 svc_expkey_hash(struct svc_expkey *item)
275 {
276 int hash = item->ek_fsidtype;
277 char * cp = (char*)item->ek_fsid;
278 int len = key_len(item->ek_fsidtype);
279
280 hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
281 hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
282 hash &= EXPKEY_HASHMASK;
283 return hash;
284 }
285
286 static struct svc_expkey *
287 svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *item)
288 {
289 struct cache_head *ch;
290 int hash = svc_expkey_hash(item);
291
292 ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash);
293 if (ch)
294 return container_of(ch, struct svc_expkey, h);
295 else
296 return NULL;
297 }
298
299 static struct svc_expkey *
300 svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
301 struct svc_expkey *old)
302 {
303 struct cache_head *ch;
304 int hash = svc_expkey_hash(new);
305
306 ch = sunrpc_cache_update(cd, &new->h, &old->h, hash);
307 if (ch)
308 return container_of(ch, struct svc_expkey, h);
309 else
310 return NULL;
311 }
312
313
314 #define EXPORT_HASHBITS 8
315 #define EXPORT_HASHMAX (1<< EXPORT_HASHBITS)
316
317 static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
318 {
319 struct nfsd4_fs_location *locations = fsloc->locations;
320 int i;
321
322 if (!locations)
323 return;
324
325 for (i = 0; i < fsloc->locations_count; i++) {
326 kfree(locations[i].path);
327 kfree(locations[i].hosts);
328 }
329
330 kfree(locations);
331 fsloc->locations = NULL;
332 }
333
334 static void svc_export_put(struct kref *ref)
335 {
336 struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
337 path_put(&exp->ex_path);
338 auth_domain_put(exp->ex_client);
339 nfsd4_fslocs_free(&exp->ex_fslocs);
340 kfree(exp->ex_uuid);
341 kfree_rcu(exp, ex_rcu);
342 }
343
344 static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h)
345 {
346 return sunrpc_cache_pipe_upcall(cd, h);
347 }
348
349 static void svc_export_request(struct cache_detail *cd,
350 struct cache_head *h,
351 char **bpp, int *blen)
352 {
353 /* client path */
354 struct svc_export *exp = container_of(h, struct svc_export, h);
355 char *pth;
356
357 qword_add(bpp, blen, exp->ex_client->name);
358 pth = d_path(&exp->ex_path, *bpp, *blen);
359 if (IS_ERR(pth)) {
360 /* is this correct? */
361 (*bpp)[0] = '\n';
362 return;
363 }
364 qword_add(bpp, blen, pth);
365 (*bpp)[-1] = '\n';
366 }
367
368 static struct svc_export *svc_export_update(struct svc_export *new,
369 struct svc_export *old);
370 static struct svc_export *svc_export_lookup(struct svc_export *);
371
372 static int check_export(struct inode *inode, int *flags, unsigned char *uuid)
373 {
374
375 /*
376 * We currently export only dirs, regular files, and (for v4
377 * pseudoroot) symlinks.
378 */
379 if (!S_ISDIR(inode->i_mode) &&
380 !S_ISLNK(inode->i_mode) &&
381 !S_ISREG(inode->i_mode))
382 return -ENOTDIR;
383
384 /*
385 * Mountd should never pass down a writeable V4ROOT export, but,
386 * just to make sure:
387 */
388 if (*flags & NFSEXP_V4ROOT)
389 *flags |= NFSEXP_READONLY;
390
391 /* There are two requirements on a filesystem to be exportable.
392 * 1: We must be able to identify the filesystem from a number.
393 * either a device number (so FS_REQUIRES_DEV needed)
394 * or an FSID number (so NFSEXP_FSID or ->uuid is needed).
395 * 2: We must be able to find an inode from a filehandle.
396 * This means that s_export_op must be set.
397 */
398 if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
399 !(*flags & NFSEXP_FSID) &&
400 uuid == NULL) {
401 dprintk("exp_export: export of non-dev fs without fsid\n");
402 return -EINVAL;
403 }
404
405 if (!inode->i_sb->s_export_op ||
406 !inode->i_sb->s_export_op->fh_to_dentry) {
407 dprintk("exp_export: export of invalid fs type.\n");
408 return -EINVAL;
409 }
410
411 return 0;
412
413 }
414
415 #ifdef CONFIG_NFSD_V4
416
417 static int
418 fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
419 {
420 int len;
421 int migrated, i, err;
422
423 /* more than one fsloc */
424 if (fsloc->locations)
425 return -EINVAL;
426
427 /* listsize */
428 err = get_uint(mesg, &fsloc->locations_count);
429 if (err)
430 return err;
431 if (fsloc->locations_count > MAX_FS_LOCATIONS)
432 return -EINVAL;
433 if (fsloc->locations_count == 0)
434 return 0;
435
436 fsloc->locations = kcalloc(fsloc->locations_count,
437 sizeof(struct nfsd4_fs_location),
438 GFP_KERNEL);
439 if (!fsloc->locations)
440 return -ENOMEM;
441 for (i=0; i < fsloc->locations_count; i++) {
442 /* colon separated host list */
443 err = -EINVAL;
444 len = qword_get(mesg, buf, PAGE_SIZE);
445 if (len <= 0)
446 goto out_free_all;
447 err = -ENOMEM;
448 fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
449 if (!fsloc->locations[i].hosts)
450 goto out_free_all;
451 err = -EINVAL;
452 /* slash separated path component list */
453 len = qword_get(mesg, buf, PAGE_SIZE);
454 if (len <= 0)
455 goto out_free_all;
456 err = -ENOMEM;
457 fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
458 if (!fsloc->locations[i].path)
459 goto out_free_all;
460 }
461 /* migrated */
462 err = get_int(mesg, &migrated);
463 if (err)
464 goto out_free_all;
465 err = -EINVAL;
466 if (migrated < 0 || migrated > 1)
467 goto out_free_all;
468 fsloc->migrated = migrated;
469 return 0;
470 out_free_all:
471 nfsd4_fslocs_free(fsloc);
472 return err;
473 }
474
475 static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
476 {
477 struct exp_flavor_info *f;
478 u32 listsize;
479 int err;
480
481 /* more than one secinfo */
482 if (exp->ex_nflavors)
483 return -EINVAL;
484
485 err = get_uint(mesg, &listsize);
486 if (err)
487 return err;
488 if (listsize > MAX_SECINFO_LIST)
489 return -EINVAL;
490
491 for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
492 err = get_uint(mesg, &f->pseudoflavor);
493 if (err)
494 return err;
495 /*
496 * XXX: It would be nice to also check whether this
497 * pseudoflavor is supported, so we can discover the
498 * problem at export time instead of when a client fails
499 * to authenticate.
500 */
501 err = get_uint(mesg, &f->flags);
502 if (err)
503 return err;
504 /* Only some flags are allowed to differ between flavors: */
505 if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
506 return -EINVAL;
507 }
508 exp->ex_nflavors = listsize;
509 return 0;
510 }
511
512 #else /* CONFIG_NFSD_V4 */
513 static inline int
514 fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
515 static inline int
516 secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
517 #endif
518
519 static inline int
520 nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid)
521 {
522 int len;
523
524 /* more than one uuid */
525 if (*puuid)
526 return -EINVAL;
527
528 /* expect a 16 byte uuid encoded as \xXXXX... */
529 len = qword_get(mesg, buf, PAGE_SIZE);
530 if (len != EX_UUID_LEN)
531 return -EINVAL;
532
533 *puuid = kmemdup(buf, EX_UUID_LEN, GFP_KERNEL);
534 if (*puuid == NULL)
535 return -ENOMEM;
536
537 return 0;
538 }
539
540 static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
541 {
542 /* client path expiry [flags anonuid anongid fsid] */
543 char *buf;
544 int len;
545 int err;
546 struct auth_domain *dom = NULL;
547 struct svc_export exp = {}, *expp;
548 int an_int;
549
550 if (mesg[mlen-1] != '\n')
551 return -EINVAL;
552 mesg[mlen-1] = 0;
553
554 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
555 if (!buf)
556 return -ENOMEM;
557
558 /* client */
559 err = -EINVAL;
560 len = qword_get(&mesg, buf, PAGE_SIZE);
561 if (len <= 0)
562 goto out;
563
564 err = -ENOENT;
565 dom = auth_domain_find(buf);
566 if (!dom)
567 goto out;
568
569 /* path */
570 err = -EINVAL;
571 if ((len = qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
572 goto out1;
573
574 err = kern_path(buf, 0, &exp.ex_path);
575 if (err)
576 goto out1;
577
578 exp.ex_client = dom;
579 exp.cd = cd;
580 exp.ex_devid_map = NULL;
581
582 /* expiry */
583 err = -EINVAL;
584 exp.h.expiry_time = get_expiry(&mesg);
585 if (exp.h.expiry_time == 0)
586 goto out3;
587
588 /* flags */
589 err = get_int(&mesg, &an_int);
590 if (err == -ENOENT) {
591 err = 0;
592 set_bit(CACHE_NEGATIVE, &exp.h.flags);
593 } else {
594 if (err || an_int < 0)
595 goto out3;
596 exp.ex_flags= an_int;
597
598 /* anon uid */
599 err = get_int(&mesg, &an_int);
600 if (err)
601 goto out3;
602 exp.ex_anon_uid= make_kuid(current_user_ns(), an_int);
603
604 /* anon gid */
605 err = get_int(&mesg, &an_int);
606 if (err)
607 goto out3;
608 exp.ex_anon_gid= make_kgid(current_user_ns(), an_int);
609
610 /* fsid */
611 err = get_int(&mesg, &an_int);
612 if (err)
613 goto out3;
614 exp.ex_fsid = an_int;
615
616 while ((len = qword_get(&mesg, buf, PAGE_SIZE)) > 0) {
617 if (strcmp(buf, "fsloc") == 0)
618 err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
619 else if (strcmp(buf, "uuid") == 0)
620 err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid);
621 else if (strcmp(buf, "secinfo") == 0)
622 err = secinfo_parse(&mesg, buf, &exp);
623 else
624 /* quietly ignore unknown words and anything
625 * following. Newer user-space can try to set
626 * new values, then see what the result was.
627 */
628 break;
629 if (err)
630 goto out4;
631 }
632
633 err = check_export(d_inode(exp.ex_path.dentry), &exp.ex_flags,
634 exp.ex_uuid);
635 if (err)
636 goto out4;
637 /*
638 * No point caching this if it would immediately expire.
639 * Also, this protects exportfs's dummy export from the
640 * anon_uid/anon_gid checks:
641 */
642 if (exp.h.expiry_time < seconds_since_boot())
643 goto out4;
644 /*
645 * For some reason exportfs has been passing down an
646 * invalid (-1) uid & gid on the "dummy" export which it
647 * uses to test export support. To make sure exportfs
648 * sees errors from check_export we therefore need to
649 * delay these checks till after check_export:
650 */
651 err = -EINVAL;
652 if (!uid_valid(exp.ex_anon_uid))
653 goto out4;
654 if (!gid_valid(exp.ex_anon_gid))
655 goto out4;
656 err = 0;
657
658 nfsd4_setup_layout_type(&exp);
659 }
660
661 expp = svc_export_lookup(&exp);
662 if (!expp) {
663 err = -ENOMEM;
664 goto out4;
665 }
666 expp = svc_export_update(&exp, expp);
667 if (expp) {
668 trace_nfsd_export_update(expp);
669 cache_flush();
670 exp_put(expp);
671 } else
672 err = -ENOMEM;
673 out4:
674 nfsd4_fslocs_free(&exp.ex_fslocs);
675 kfree(exp.ex_uuid);
676 out3:
677 path_put(&exp.ex_path);
678 out1:
679 auth_domain_put(dom);
680 out:
681 kfree(buf);
682 return err;
683 }
684
685 static void exp_flags(struct seq_file *m, int flag, int fsid,
686 kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
687 static void show_secinfo(struct seq_file *m, struct svc_export *exp);
688
689 static int svc_export_show(struct seq_file *m,
690 struct cache_detail *cd,
691 struct cache_head *h)
692 {
693 struct svc_export *exp ;
694
695 if (h ==NULL) {
696 seq_puts(m, "#path domain(flags)\n");
697 return 0;
698 }
699 exp = container_of(h, struct svc_export, h);
700 seq_path(m, &exp->ex_path, " \t\n\\");
701 seq_putc(m, '\t');
702 seq_escape(m, exp->ex_client->name, " \t\n\\");
703 seq_putc(m, '(');
704 if (test_bit(CACHE_VALID, &h->flags) &&
705 !test_bit(CACHE_NEGATIVE, &h->flags)) {
706 exp_flags(m, exp->ex_flags, exp->ex_fsid,
707 exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
708 if (exp->ex_uuid) {
709 int i;
710 seq_puts(m, ",uuid=");
711 for (i = 0; i < EX_UUID_LEN; i++) {
712 if ((i&3) == 0 && i)
713 seq_putc(m, ':');
714 seq_printf(m, "%02x", exp->ex_uuid[i]);
715 }
716 }
717 show_secinfo(m, exp);
718 }
719 seq_puts(m, ")\n");
720 return 0;
721 }
722 static int svc_export_match(struct cache_head *a, struct cache_head *b)
723 {
724 struct svc_export *orig = container_of(a, struct svc_export, h);
725 struct svc_export *new = container_of(b, struct svc_export, h);
726 return orig->ex_client == new->ex_client &&
727 path_equal(&orig->ex_path, &new->ex_path);
728 }
729
730 static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
731 {
732 struct svc_export *new = container_of(cnew, struct svc_export, h);
733 struct svc_export *item = container_of(citem, struct svc_export, h);
734
735 kref_get(&item->ex_client->ref);
736 new->ex_client = item->ex_client;
737 new->ex_path = item->ex_path;
738 path_get(&item->ex_path);
739 new->ex_fslocs.locations = NULL;
740 new->ex_fslocs.locations_count = 0;
741 new->ex_fslocs.migrated = 0;
742 new->ex_layout_types = 0;
743 new->ex_uuid = NULL;
744 new->cd = item->cd;
745 }
746
747 static void export_update(struct cache_head *cnew, struct cache_head *citem)
748 {
749 struct svc_export *new = container_of(cnew, struct svc_export, h);
750 struct svc_export *item = container_of(citem, struct svc_export, h);
751 int i;
752
753 new->ex_flags = item->ex_flags;
754 new->ex_anon_uid = item->ex_anon_uid;
755 new->ex_anon_gid = item->ex_anon_gid;
756 new->ex_fsid = item->ex_fsid;
757 new->ex_devid_map = item->ex_devid_map;
758 item->ex_devid_map = NULL;
759 new->ex_uuid = item->ex_uuid;
760 item->ex_uuid = NULL;
761 new->ex_fslocs.locations = item->ex_fslocs.locations;
762 item->ex_fslocs.locations = NULL;
763 new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
764 item->ex_fslocs.locations_count = 0;
765 new->ex_fslocs.migrated = item->ex_fslocs.migrated;
766 item->ex_fslocs.migrated = 0;
767 new->ex_layout_types = item->ex_layout_types;
768 new->ex_nflavors = item->ex_nflavors;
769 for (i = 0; i < MAX_SECINFO_LIST; i++) {
770 new->ex_flavors[i] = item->ex_flavors[i];
771 }
772 }
773
774 static struct cache_head *svc_export_alloc(void)
775 {
776 struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
777 if (i)
778 return &i->h;
779 else
780 return NULL;
781 }
782
783 static const struct cache_detail svc_export_cache_template = {
784 .owner = THIS_MODULE,
785 .hash_size = EXPORT_HASHMAX,
786 .name = "nfsd.export",
787 .cache_put = svc_export_put,
788 .cache_upcall = svc_export_upcall,
789 .cache_request = svc_export_request,
790 .cache_parse = svc_export_parse,
791 .cache_show = svc_export_show,
792 .match = svc_export_match,
793 .init = svc_export_init,
794 .update = export_update,
795 .alloc = svc_export_alloc,
796 };
797
798 static int
799 svc_export_hash(struct svc_export *exp)
800 {
801 int hash;
802
803 hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
804 hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
805 hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
806 return hash;
807 }
808
809 static struct svc_export *
810 svc_export_lookup(struct svc_export *exp)
811 {
812 struct cache_head *ch;
813 int hash = svc_export_hash(exp);
814
815 ch = sunrpc_cache_lookup_rcu(exp->cd, &exp->h, hash);
816 if (ch)
817 return container_of(ch, struct svc_export, h);
818 else
819 return NULL;
820 }
821
822 static struct svc_export *
823 svc_export_update(struct svc_export *new, struct svc_export *old)
824 {
825 struct cache_head *ch;
826 int hash = svc_export_hash(old);
827
828 ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash);
829 if (ch)
830 return container_of(ch, struct svc_export, h);
831 else
832 return NULL;
833 }
834
835
836 static struct svc_expkey *
837 exp_find_key(struct cache_detail *cd, struct auth_domain *clp, int fsid_type,
838 u32 *fsidv, struct cache_req *reqp)
839 {
840 struct svc_expkey key, *ek;
841 int err;
842
843 if (!clp)
844 return ERR_PTR(-ENOENT);
845
846 key.ek_client = clp;
847 key.ek_fsidtype = fsid_type;
848 memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
849
850 ek = svc_expkey_lookup(cd, &key);
851 if (ek == NULL)
852 return ERR_PTR(-ENOMEM);
853 err = cache_check(cd, &ek->h, reqp);
854 if (err) {
855 trace_nfsd_exp_find_key(&key, err);
856 return ERR_PTR(err);
857 }
858 return ek;
859 }
860
861 static struct svc_export *
862 exp_get_by_name(struct cache_detail *cd, struct auth_domain *clp,
863 const struct path *path, struct cache_req *reqp)
864 {
865 struct svc_export *exp, key;
866 int err;
867
868 if (!clp)
869 return ERR_PTR(-ENOENT);
870
871 key.ex_client = clp;
872 key.ex_path = *path;
873 key.cd = cd;
874
875 exp = svc_export_lookup(&key);
876 if (exp == NULL)
877 return ERR_PTR(-ENOMEM);
878 err = cache_check(cd, &exp->h, reqp);
879 if (err) {
880 trace_nfsd_exp_get_by_name(&key, err);
881 return ERR_PTR(err);
882 }
883 return exp;
884 }
885
886 /*
887 * Find the export entry for a given dentry.
888 */
889 static struct svc_export *
890 exp_parent(struct cache_detail *cd, struct auth_domain *clp, struct path *path)
891 {
892 struct dentry *saved = dget(path->dentry);
893 struct svc_export *exp = exp_get_by_name(cd, clp, path, NULL);
894
895 while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
896 struct dentry *parent = dget_parent(path->dentry);
897 dput(path->dentry);
898 path->dentry = parent;
899 exp = exp_get_by_name(cd, clp, path, NULL);
900 }
901 dput(path->dentry);
902 path->dentry = saved;
903 return exp;
904 }
905
906
907
908 /*
909 * Obtain the root fh on behalf of a client.
910 * This could be done in user space, but I feel that it adds some safety
911 * since its harder to fool a kernel module than a user space program.
912 */
913 int
914 exp_rootfh(struct net *net, struct auth_domain *clp, char *name,
915 struct knfsd_fh *f, int maxsize)
916 {
917 struct svc_export *exp;
918 struct path path;
919 struct inode *inode;
920 struct svc_fh fh;
921 int err;
922 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
923 struct cache_detail *cd = nn->svc_export_cache;
924
925 err = -EPERM;
926 /* NB: we probably ought to check that it's NUL-terminated */
927 if (kern_path(name, 0, &path)) {
928 printk("nfsd: exp_rootfh path not found %s", name);
929 return err;
930 }
931 inode = d_inode(path.dentry);
932
933 dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
934 name, path.dentry, clp->name,
935 inode->i_sb->s_id, inode->i_ino);
936 exp = exp_parent(cd, clp, &path);
937 if (IS_ERR(exp)) {
938 err = PTR_ERR(exp);
939 goto out;
940 }
941
942 /*
943 * fh must be initialized before calling fh_compose
944 */
945 fh_init(&fh, maxsize);
946 if (fh_compose(&fh, exp, path.dentry, NULL))
947 err = -EINVAL;
948 else
949 err = 0;
950 memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
951 fh_put(&fh);
952 exp_put(exp);
953 out:
954 path_put(&path);
955 return err;
956 }
957
958 static struct svc_export *exp_find(struct cache_detail *cd,
959 struct auth_domain *clp, int fsid_type,
960 u32 *fsidv, struct cache_req *reqp)
961 {
962 struct svc_export *exp;
963 struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
964 struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
965 if (IS_ERR(ek))
966 return ERR_CAST(ek);
967
968 exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
969 cache_put(&ek->h, nn->svc_expkey_cache);
970
971 if (IS_ERR(exp))
972 return ERR_CAST(exp);
973 return exp;
974 }
975
976 __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
977 {
978 struct exp_flavor_info *f;
979 struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
980
981 /* legacy gss-only clients are always OK: */
982 if (exp->ex_client == rqstp->rq_gssclient)
983 return 0;
984 /* ip-address based client; check sec= export option: */
985 for (f = exp->ex_flavors; f < end; f++) {
986 if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
987 return 0;
988 }
989 /* defaults in absence of sec= options: */
990 if (exp->ex_nflavors == 0) {
991 if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
992 rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
993 return 0;
994 }
995
996 /* If the compound op contains a spo_must_allowed op,
997 * it will be sent with integrity/protection which
998 * will have to be expressly allowed on mounts that
999 * don't support it
1000 */
1001
1002 if (nfsd4_spo_must_allow(rqstp))
1003 return 0;
1004
1005 return nfserr_wrongsec;
1006 }
1007
1008 /*
1009 * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
1010 * auth_unix client) if it's available and has secinfo information;
1011 * otherwise, will try to use rq_gssclient.
1012 *
1013 * Called from functions that handle requests; functions that do work on
1014 * behalf of mountd are passed a single client name to use, and should
1015 * use exp_get_by_name() or exp_find().
1016 */
1017 struct svc_export *
1018 rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path)
1019 {
1020 struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1021 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1022 struct cache_detail *cd = nn->svc_export_cache;
1023
1024 if (rqstp->rq_client == NULL)
1025 goto gss;
1026
1027 /* First try the auth_unix client: */
1028 exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle);
1029 if (PTR_ERR(exp) == -ENOENT)
1030 goto gss;
1031 if (IS_ERR(exp))
1032 return exp;
1033 /* If it has secinfo, assume there are no gss/... clients */
1034 if (exp->ex_nflavors > 0)
1035 return exp;
1036 gss:
1037 /* Otherwise, try falling back on gss client */
1038 if (rqstp->rq_gssclient == NULL)
1039 return exp;
1040 gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle);
1041 if (PTR_ERR(gssexp) == -ENOENT)
1042 return exp;
1043 if (!IS_ERR(exp))
1044 exp_put(exp);
1045 return gssexp;
1046 }
1047
1048 struct svc_export *
1049 rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
1050 {
1051 struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
1052 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1053 struct cache_detail *cd = nn->svc_export_cache;
1054
1055 if (rqstp->rq_client == NULL)
1056 goto gss;
1057
1058 /* First try the auth_unix client: */
1059 exp = exp_find(cd, rqstp->rq_client, fsid_type,
1060 fsidv, &rqstp->rq_chandle);
1061 if (PTR_ERR(exp) == -ENOENT)
1062 goto gss;
1063 if (IS_ERR(exp))
1064 return exp;
1065 /* If it has secinfo, assume there are no gss/... clients */
1066 if (exp->ex_nflavors > 0)
1067 return exp;
1068 gss:
1069 /* Otherwise, try falling back on gss client */
1070 if (rqstp->rq_gssclient == NULL)
1071 return exp;
1072 gssexp = exp_find(cd, rqstp->rq_gssclient, fsid_type, fsidv,
1073 &rqstp->rq_chandle);
1074 if (PTR_ERR(gssexp) == -ENOENT)
1075 return exp;
1076 if (!IS_ERR(exp))
1077 exp_put(exp);
1078 return gssexp;
1079 }
1080
1081 struct svc_export *
1082 rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
1083 {
1084 struct dentry *saved = dget(path->dentry);
1085 struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
1086
1087 while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
1088 struct dentry *parent = dget_parent(path->dentry);
1089 dput(path->dentry);
1090 path->dentry = parent;
1091 exp = rqst_exp_get_by_name(rqstp, path);
1092 }
1093 dput(path->dentry);
1094 path->dentry = saved;
1095 return exp;
1096 }
1097
1098 struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
1099 {
1100 u32 fsidv[2];
1101
1102 mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
1103
1104 return rqst_exp_find(rqstp, FSID_NUM, fsidv);
1105 }
1106
1107 /*
1108 * Called when we need the filehandle for the root of the pseudofs,
1109 * for a given NFSv4 client. The root is defined to be the
1110 * export point with fsid==0
1111 */
1112 __be32
1113 exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
1114 {
1115 struct svc_export *exp;
1116 __be32 rv;
1117
1118 exp = rqst_find_fsidzero_export(rqstp);
1119 if (IS_ERR(exp))
1120 return nfserrno(PTR_ERR(exp));
1121 rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
1122 exp_put(exp);
1123 return rv;
1124 }
1125
1126 static struct flags {
1127 int flag;
1128 char *name[2];
1129 } expflags[] = {
1130 { NFSEXP_READONLY, {"ro", "rw"}},
1131 { NFSEXP_INSECURE_PORT, {"insecure", ""}},
1132 { NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
1133 { NFSEXP_ALLSQUASH, {"all_squash", ""}},
1134 { NFSEXP_ASYNC, {"async", "sync"}},
1135 { NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
1136 { NFSEXP_NOREADDIRPLUS, {"nordirplus", ""}},
1137 { NFSEXP_NOHIDE, {"nohide", ""}},
1138 { NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
1139 { NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
1140 { NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
1141 { NFSEXP_V4ROOT, {"v4root", ""}},
1142 { NFSEXP_PNFS, {"pnfs", ""}},
1143 { NFSEXP_SECURITY_LABEL, {"security_label", ""}},
1144 { 0, {"", ""}}
1145 };
1146
1147 static void show_expflags(struct seq_file *m, int flags, int mask)
1148 {
1149 struct flags *flg;
1150 int state, first = 0;
1151
1152 for (flg = expflags; flg->flag; flg++) {
1153 if (flg->flag & ~mask)
1154 continue;
1155 state = (flg->flag & flags) ? 0 : 1;
1156 if (*flg->name[state])
1157 seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
1158 }
1159 }
1160
1161 static void show_secinfo_flags(struct seq_file *m, int flags)
1162 {
1163 seq_printf(m, ",");
1164 show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
1165 }
1166
1167 static bool secinfo_flags_equal(int f, int g)
1168 {
1169 f &= NFSEXP_SECINFO_FLAGS;
1170 g &= NFSEXP_SECINFO_FLAGS;
1171 return f == g;
1172 }
1173
1174 static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
1175 {
1176 int flags;
1177
1178 flags = (*fp)->flags;
1179 seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
1180 (*fp)++;
1181 while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
1182 seq_printf(m, ":%d", (*fp)->pseudoflavor);
1183 (*fp)++;
1184 }
1185 return flags;
1186 }
1187
1188 static void show_secinfo(struct seq_file *m, struct svc_export *exp)
1189 {
1190 struct exp_flavor_info *f;
1191 struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
1192 int flags;
1193
1194 if (exp->ex_nflavors == 0)
1195 return;
1196 f = exp->ex_flavors;
1197 flags = show_secinfo_run(m, &f, end);
1198 if (!secinfo_flags_equal(flags, exp->ex_flags))
1199 show_secinfo_flags(m, flags);
1200 while (f != end) {
1201 flags = show_secinfo_run(m, &f, end);
1202 show_secinfo_flags(m, flags);
1203 }
1204 }
1205
1206 static void exp_flags(struct seq_file *m, int flag, int fsid,
1207 kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
1208 {
1209 struct user_namespace *userns = m->file->f_cred->user_ns;
1210
1211 show_expflags(m, flag, NFSEXP_ALLFLAGS);
1212 if (flag & NFSEXP_FSID)
1213 seq_printf(m, ",fsid=%d", fsid);
1214 if (!uid_eq(anonu, make_kuid(userns, (uid_t)-2)) &&
1215 !uid_eq(anonu, make_kuid(userns, 0x10000-2)))
1216 seq_printf(m, ",anonuid=%u", from_kuid_munged(userns, anonu));
1217 if (!gid_eq(anong, make_kgid(userns, (gid_t)-2)) &&
1218 !gid_eq(anong, make_kgid(userns, 0x10000-2)))
1219 seq_printf(m, ",anongid=%u", from_kgid_munged(userns, anong));
1220 if (fsloc && fsloc->locations_count > 0) {
1221 char *loctype = (fsloc->migrated) ? "refer" : "replicas";
1222 int i;
1223
1224 seq_printf(m, ",%s=", loctype);
1225 seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
1226 seq_putc(m, '@');
1227 seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
1228 for (i = 1; i < fsloc->locations_count; i++) {
1229 seq_putc(m, ';');
1230 seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
1231 seq_putc(m, '@');
1232 seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
1233 }
1234 }
1235 }
1236
1237 static int e_show(struct seq_file *m, void *p)
1238 {
1239 struct cache_head *cp = p;
1240 struct svc_export *exp = container_of(cp, struct svc_export, h);
1241 struct cache_detail *cd = m->private;
1242
1243 if (p == SEQ_START_TOKEN) {
1244 seq_puts(m, "# Version 1.1\n");
1245 seq_puts(m, "# Path Client(Flags) # IPs\n");
1246 return 0;
1247 }
1248
1249 exp_get(exp);
1250 if (cache_check(cd, &exp->h, NULL))
1251 return 0;
1252 exp_put(exp);
1253 return svc_export_show(m, cd, cp);
1254 }
1255
1256 const struct seq_operations nfs_exports_op = {
1257 .start = cache_seq_start_rcu,
1258 .next = cache_seq_next_rcu,
1259 .stop = cache_seq_stop_rcu,
1260 .show = e_show,
1261 };
1262
1263 /*
1264 * Initialize the exports module.
1265 */
1266 int
1267 nfsd_export_init(struct net *net)
1268 {
1269 int rv;
1270 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1271
1272 dprintk("nfsd: initializing export module (net: %x).\n", net->ns.inum);
1273
1274 nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
1275 if (IS_ERR(nn->svc_export_cache))
1276 return PTR_ERR(nn->svc_export_cache);
1277 rv = cache_register_net(nn->svc_export_cache, net);
1278 if (rv)
1279 goto destroy_export_cache;
1280
1281 nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
1282 if (IS_ERR(nn->svc_expkey_cache)) {
1283 rv = PTR_ERR(nn->svc_expkey_cache);
1284 goto unregister_export_cache;
1285 }
1286 rv = cache_register_net(nn->svc_expkey_cache, net);
1287 if (rv)
1288 goto destroy_expkey_cache;
1289 return 0;
1290
1291 destroy_expkey_cache:
1292 cache_destroy_net(nn->svc_expkey_cache, net);
1293 unregister_export_cache:
1294 cache_unregister_net(nn->svc_export_cache, net);
1295 destroy_export_cache:
1296 cache_destroy_net(nn->svc_export_cache, net);
1297 return rv;
1298 }
1299
1300 /*
1301 * Flush exports table - called when last nfsd thread is killed
1302 */
1303 void
1304 nfsd_export_flush(struct net *net)
1305 {
1306 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1307
1308 cache_purge(nn->svc_expkey_cache);
1309 cache_purge(nn->svc_export_cache);
1310 }
1311
1312 /*
1313 * Shutdown the exports module.
1314 */
1315 void
1316 nfsd_export_shutdown(struct net *net)
1317 {
1318 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
1319
1320 dprintk("nfsd: shutting down export module (net: %x).\n", net->ns.inum);
1321
1322 cache_unregister_net(nn->svc_expkey_cache, net);
1323 cache_unregister_net(nn->svc_export_cache, net);
1324 cache_destroy_net(nn->svc_expkey_cache, net);
1325 cache_destroy_net(nn->svc_export_cache, net);
1326 svcauth_unix_purge(net);
1327
1328 dprintk("nfsd: export shutdown complete (net: %x).\n", net->ns.inum);
1329 }