1 /*
2 * Mapping of UID/GIDs to name and vice versa.
3 *
4 * Copyright (c) 2002, 2003 The Regents of the University of
5 * Michigan. All rights reserved.
6 *
7 * Marius Aamodt Eriksen <marius@umich.edu>
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
29 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35 #include <linux/module.h>
36 #include <linux/seq_file.h>
37 #include <linux/sched.h>
38 #include <linux/slab.h>
39 #include <linux/sunrpc/svc_xprt.h>
40 #include <net/net_namespace.h>
41 #include "idmap.h"
42 #include "nfsd.h"
43 #include "netns.h"
44 #include "vfs.h"
45
46 /*
47 * Turn off idmapping when using AUTH_SYS.
48 */
49 static bool nfs4_disable_idmapping = true;
50 module_param(nfs4_disable_idmapping, bool, 0644);
51 MODULE_PARM_DESC(nfs4_disable_idmapping,
52 "Turn off server's NFSv4 idmapping when using 'sec=sys'");
53
54 /*
55 * Cache entry
56 */
57
58 /*
59 * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
60 * that.
61 */
62
63 struct ent {
64 struct cache_head h;
65 int type; /* User / Group */
66 u32 id;
67 char name[IDMAP_NAMESZ];
68 char authname[IDMAP_NAMESZ];
69 struct rcu_head rcu_head;
70 };
71
72 /* Common entry handling */
73
74 #define ENT_HASHBITS 8
75 #define ENT_HASHMAX (1 << ENT_HASHBITS)
76
77 static void
78 ent_init(struct cache_head *cnew, struct cache_head *citm)
79 {
80 struct ent *new = container_of(cnew, struct ent, h);
81 struct ent *itm = container_of(citm, struct ent, h);
82
83 new->id = itm->id;
84 new->type = itm->type;
85
86 strscpy(new->name, itm->name, sizeof(new->name));
87 strscpy(new->authname, itm->authname, sizeof(new->authname));
88 }
89
90 static void
91 ent_put(struct kref *ref)
92 {
93 struct ent *map = container_of(ref, struct ent, h.ref);
94 kfree_rcu(map, rcu_head);
95 }
96
97 static struct cache_head *
98 ent_alloc(void)
99 {
100 struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
101 if (e)
102 return &e->h;
103 else
104 return NULL;
105 }
106
107 /*
108 * ID -> Name cache
109 */
110
111 static uint32_t
112 idtoname_hash(struct ent *ent)
113 {
114 uint32_t hash;
115
116 hash = hash_str(ent->authname, ENT_HASHBITS);
117 hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
118
119 /* Flip LSB for user/group */
120 if (ent->type == IDMAP_TYPE_GROUP)
121 hash ^= 1;
122
123 return hash;
124 }
125
126 static int
127 idtoname_upcall(struct cache_detail *cd, struct cache_head *h)
128 {
129 return sunrpc_cache_pipe_upcall_timeout(cd, h);
130 }
131
132 static void
133 idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
134 int *blen)
135 {
136 struct ent *ent = container_of(ch, struct ent, h);
137 char idstr[11];
138
139 qword_add(bpp, blen, ent->authname);
140 snprintf(idstr, sizeof(idstr), "%u", ent->id);
141 qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
142 qword_add(bpp, blen, idstr);
143
144 (*bpp)[-1] = '\n';
145 }
146
147 static int
148 idtoname_match(struct cache_head *ca, struct cache_head *cb)
149 {
150 struct ent *a = container_of(ca, struct ent, h);
151 struct ent *b = container_of(cb, struct ent, h);
152
153 return (a->id == b->id && a->type == b->type &&
154 strcmp(a->authname, b->authname) == 0);
155 }
156
157 static int
158 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
159 {
160 struct ent *ent;
161
162 if (h == NULL) {
163 seq_puts(m, "#domain type id [name]\n");
164 return 0;
165 }
166 ent = container_of(h, struct ent, h);
167 seq_printf(m, "%s %s %u", ent->authname,
168 ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
169 ent->id);
170 if (test_bit(CACHE_VALID, &h->flags))
171 seq_printf(m, " %s", ent->name);
172 seq_putc(m, '\n');
173 return 0;
174 }
175
176 static void
177 warn_no_idmapd(struct cache_detail *detail, int has_died)
178 {
179 printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
180 has_died ? "died" : "not been started");
181 }
182
183
184 static int idtoname_parse(struct cache_detail *, char *, int);
185 static struct ent *idtoname_lookup(struct cache_detail *, struct ent *);
186 static struct ent *idtoname_update(struct cache_detail *, struct ent *,
187 struct ent *);
188
189 static const struct cache_detail idtoname_cache_template = {
190 .owner = THIS_MODULE,
191 .hash_size = ENT_HASHMAX,
192 .name = "nfs4.idtoname",
193 .cache_put = ent_put,
194 .cache_upcall = idtoname_upcall,
195 .cache_request = idtoname_request,
196 .cache_parse = idtoname_parse,
197 .cache_show = idtoname_show,
198 .warn_no_listener = warn_no_idmapd,
199 .match = idtoname_match,
200 .init = ent_init,
201 .update = ent_init,
202 .alloc = ent_alloc,
203 };
204
205 static int
206 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
207 {
208 struct ent ent, *res;
209 char *buf1, *bp;
210 int len;
211 int error = -EINVAL;
212
213 if (buf[buflen - 1] != '\n')
214 return (-EINVAL);
215 buf[buflen - 1]= '\0';
216
217 buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
218 if (buf1 == NULL)
219 return (-ENOMEM);
220
221 memset(&ent, 0, sizeof(ent));
222
223 /* Authentication name */
224 len = qword_get(&buf, buf1, PAGE_SIZE);
225 if (len <= 0 || len >= IDMAP_NAMESZ)
226 goto out;
227 memcpy(ent.authname, buf1, sizeof(ent.authname));
228
229 /* Type */
230 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
231 goto out;
232 ent.type = strcmp(buf1, "user") == 0 ?
233 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
234
235 /* ID */
236 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
237 goto out;
238 ent.id = simple_strtoul(buf1, &bp, 10);
239 if (bp == buf1)
240 goto out;
241
242 /* expiry */
243 error = get_expiry(&buf, &ent.h.expiry_time);
244 if (error)
245 goto out;
246
247 error = -ENOMEM;
248 res = idtoname_lookup(cd, &ent);
249 if (!res)
250 goto out;
251
252 /* Name */
253 error = -EINVAL;
254 len = qword_get(&buf, buf1, PAGE_SIZE);
255 if (len < 0 || len >= IDMAP_NAMESZ)
256 goto out;
257 if (len == 0)
258 set_bit(CACHE_NEGATIVE, &ent.h.flags);
259 else
260 memcpy(ent.name, buf1, sizeof(ent.name));
261 error = -ENOMEM;
262 res = idtoname_update(cd, &ent, res);
263 if (res == NULL)
264 goto out;
265
266 cache_put(&res->h, cd);
267 error = 0;
268 out:
269 kfree(buf1);
270 return error;
271 }
272
273 static struct ent *
274 idtoname_lookup(struct cache_detail *cd, struct ent *item)
275 {
276 struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
277 idtoname_hash(item));
278 if (ch)
279 return container_of(ch, struct ent, h);
280 else
281 return NULL;
282 }
283
284 static struct ent *
285 idtoname_update(struct cache_detail *cd, struct ent *new, struct ent *old)
286 {
287 struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
288 idtoname_hash(new));
289 if (ch)
290 return container_of(ch, struct ent, h);
291 else
292 return NULL;
293 }
294
295
296 /*
297 * Name -> ID cache
298 */
299
300 static inline int
301 nametoid_hash(struct ent *ent)
302 {
303 return hash_str(ent->name, ENT_HASHBITS);
304 }
305
306 static int
307 nametoid_upcall(struct cache_detail *cd, struct cache_head *h)
308 {
309 return sunrpc_cache_pipe_upcall_timeout(cd, h);
310 }
311
312 static void
313 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
314 int *blen)
315 {
316 struct ent *ent = container_of(ch, struct ent, h);
317
318 qword_add(bpp, blen, ent->authname);
319 qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
320 qword_add(bpp, blen, ent->name);
321
322 (*bpp)[-1] = '\n';
323 }
324
325 static int
326 nametoid_match(struct cache_head *ca, struct cache_head *cb)
327 {
328 struct ent *a = container_of(ca, struct ent, h);
329 struct ent *b = container_of(cb, struct ent, h);
330
331 return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
332 strcmp(a->authname, b->authname) == 0);
333 }
334
335 static int
336 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
337 {
338 struct ent *ent;
339
340 if (h == NULL) {
341 seq_puts(m, "#domain type name [id]\n");
342 return 0;
343 }
344 ent = container_of(h, struct ent, h);
345 seq_printf(m, "%s %s %s", ent->authname,
346 ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
347 ent->name);
348 if (test_bit(CACHE_VALID, &h->flags))
349 seq_printf(m, " %u", ent->id);
350 seq_putc(m, '\n');
351 return 0;
352 }
353
354 static struct ent *nametoid_lookup(struct cache_detail *, struct ent *);
355 static struct ent *nametoid_update(struct cache_detail *, struct ent *,
356 struct ent *);
357 static int nametoid_parse(struct cache_detail *, char *, int);
358
359 static const struct cache_detail nametoid_cache_template = {
360 .owner = THIS_MODULE,
361 .hash_size = ENT_HASHMAX,
362 .name = "nfs4.nametoid",
363 .cache_put = ent_put,
364 .cache_upcall = nametoid_upcall,
365 .cache_request = nametoid_request,
366 .cache_parse = nametoid_parse,
367 .cache_show = nametoid_show,
368 .warn_no_listener = warn_no_idmapd,
369 .match = nametoid_match,
370 .init = ent_init,
371 .update = ent_init,
372 .alloc = ent_alloc,
373 };
374
375 static int
376 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
377 {
378 struct ent ent, *res;
379 char *buf1;
380 int len, error = -EINVAL;
381
382 if (buf[buflen - 1] != '\n')
383 return (-EINVAL);
384 buf[buflen - 1]= '\0';
385
386 buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
387 if (buf1 == NULL)
388 return (-ENOMEM);
389
390 memset(&ent, 0, sizeof(ent));
391
392 /* Authentication name */
393 len = qword_get(&buf, buf1, PAGE_SIZE);
394 if (len <= 0 || len >= IDMAP_NAMESZ)
395 goto out;
396 memcpy(ent.authname, buf1, sizeof(ent.authname));
397
398 /* Type */
399 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
400 goto out;
401 ent.type = strcmp(buf1, "user") == 0 ?
402 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
403
404 /* Name */
405 len = qword_get(&buf, buf1, PAGE_SIZE);
406 if (len <= 0 || len >= IDMAP_NAMESZ)
407 goto out;
408 memcpy(ent.name, buf1, sizeof(ent.name));
409
410 /* expiry */
411 error = get_expiry(&buf, &ent.h.expiry_time);
412 if (error)
413 goto out;
414
415 /* ID */
416 error = get_int(&buf, &ent.id);
417 if (error == -EINVAL)
418 goto out;
419 if (error == -ENOENT)
420 set_bit(CACHE_NEGATIVE, &ent.h.flags);
421
422 error = -ENOMEM;
423 res = nametoid_lookup(cd, &ent);
424 if (res == NULL)
425 goto out;
426 res = nametoid_update(cd, &ent, res);
427 if (res == NULL)
428 goto out;
429
430 cache_put(&res->h, cd);
431 error = 0;
432 out:
433 kfree(buf1);
434 return (error);
435 }
436
437
438 static struct ent *
439 nametoid_lookup(struct cache_detail *cd, struct ent *item)
440 {
441 struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
442 nametoid_hash(item));
443 if (ch)
444 return container_of(ch, struct ent, h);
445 else
446 return NULL;
447 }
448
449 static struct ent *
450 nametoid_update(struct cache_detail *cd, struct ent *new, struct ent *old)
451 {
452 struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
453 nametoid_hash(new));
454 if (ch)
455 return container_of(ch, struct ent, h);
456 else
457 return NULL;
458 }
459
460 /*
461 * Exported API
462 */
463
464 int
465 nfsd_idmap_init(struct net *net)
466 {
467 int rv;
468 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
469
470 nn->idtoname_cache = cache_create_net(&idtoname_cache_template, net);
471 if (IS_ERR(nn->idtoname_cache))
472 return PTR_ERR(nn->idtoname_cache);
473 rv = cache_register_net(nn->idtoname_cache, net);
474 if (rv)
475 goto destroy_idtoname_cache;
476 nn->nametoid_cache = cache_create_net(&nametoid_cache_template, net);
477 if (IS_ERR(nn->nametoid_cache)) {
478 rv = PTR_ERR(nn->nametoid_cache);
479 goto unregister_idtoname_cache;
480 }
481 rv = cache_register_net(nn->nametoid_cache, net);
482 if (rv)
483 goto destroy_nametoid_cache;
484 return 0;
485
486 destroy_nametoid_cache:
487 cache_destroy_net(nn->nametoid_cache, net);
488 unregister_idtoname_cache:
489 cache_unregister_net(nn->idtoname_cache, net);
490 destroy_idtoname_cache:
491 cache_destroy_net(nn->idtoname_cache, net);
492 return rv;
493 }
494
495 void
496 nfsd_idmap_shutdown(struct net *net)
497 {
498 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
499
500 cache_unregister_net(nn->idtoname_cache, net);
501 cache_unregister_net(nn->nametoid_cache, net);
502 cache_destroy_net(nn->idtoname_cache, net);
503 cache_destroy_net(nn->nametoid_cache, net);
504 }
505
506 static int
507 idmap_lookup(struct svc_rqst *rqstp,
508 struct ent *(*lookup_fn)(struct cache_detail *, struct ent *),
509 struct ent *key, struct cache_detail *detail, struct ent **item)
510 {
511 int ret;
512
513 *item = lookup_fn(detail, key);
514 if (!*item)
515 return -ENOMEM;
516 retry:
517 ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
518
519 if (ret == -ETIMEDOUT) {
520 struct ent *prev_item = *item;
521 *item = lookup_fn(detail, key);
522 if (*item != prev_item)
523 goto retry;
524 cache_put(&(*item)->h, detail);
525 }
526 return ret;
527 }
528
529 static char *
530 rqst_authname(struct svc_rqst *rqstp)
531 {
532 struct auth_domain *clp;
533
534 clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
535 return clp->name;
536 }
537
538 static __be32
539 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
540 u32 *id)
541 {
542 struct ent *item, key = {
543 .type = type,
544 };
545 int ret;
546 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
547
548 if (namelen + 1 > sizeof(key.name))
549 return nfserr_badowner;
550 memcpy(key.name, name, namelen);
551 key.name[namelen] = '\0';
552 strscpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
553 ret = idmap_lookup(rqstp, nametoid_lookup, &key, nn->nametoid_cache, &item);
554 if (ret == -ENOENT)
555 return nfserr_badowner;
556 if (ret)
557 return nfserrno(ret);
558 *id = item->id;
559 cache_put(&item->h, nn->nametoid_cache);
560 return 0;
561 }
562
563 static __be32 encode_ascii_id(struct xdr_stream *xdr, u32 id)
564 {
565 char buf[11];
566 int len;
567 __be32 *p;
568
569 len = sprintf(buf, "%u", id);
570 p = xdr_reserve_space(xdr, len + 4);
571 if (!p)
572 return nfserr_resource;
573 p = xdr_encode_opaque(p, buf, len);
574 return 0;
575 }
576
577 static __be32 idmap_id_to_name(struct xdr_stream *xdr,
578 struct svc_rqst *rqstp, int type, u32 id)
579 {
580 struct ent *item, key = {
581 .id = id,
582 .type = type,
583 };
584 __be32 status = nfs_ok;
585 __be32 *p;
586 int ret;
587 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
588
589 strscpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
590 ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item);
591 if (ret == -ENOENT)
592 return encode_ascii_id(xdr, id);
593 if (ret)
594 return nfserrno(ret);
595 ret = strlen(item->name);
596 WARN_ON_ONCE(ret > IDMAP_NAMESZ);
597
598 p = xdr_reserve_space(xdr, ret + 4);
599 if (unlikely(!p)) {
600 status = nfserr_resource;
601 goto out_put;
602 }
603 xdr_encode_opaque(p, item->name, ret);
604 out_put:
605 cache_put(&item->h, nn->idtoname_cache);
606 return status;
607 }
608
609 static bool
610 numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
611 {
612 int ret;
613 char buf[11];
614
615 if (namelen + 1 > sizeof(buf))
616 /* too long to represent a 32-bit id: */
617 return false;
618 /* Just to make sure it's null-terminated: */
619 memcpy(buf, name, namelen);
620 buf[namelen] = '\0';
621 ret = kstrtouint(buf, 10, id);
622 return ret == 0;
623 }
624
625 static __be32
626 do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
627 {
628 if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
629 if (numeric_name_to_id(rqstp, type, name, namelen, id))
630 return 0;
631 /*
632 * otherwise, fall through and try idmapping, for
633 * backwards compatibility with clients sending names:
634 */
635 return idmap_name_to_id(rqstp, type, name, namelen, id);
636 }
637
638 static __be32 encode_name_from_id(struct xdr_stream *xdr,
639 struct svc_rqst *rqstp, int type, u32 id)
640 {
641 if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
642 return encode_ascii_id(xdr, id);
643 return idmap_id_to_name(xdr, rqstp, type, id);
644 }
645
646 __be32
647 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
648 kuid_t *uid)
649 {
650 __be32 status;
651 u32 id = -1;
652
653 if (name == NULL || namelen == 0)
654 return nfserr_inval;
655
656 status = do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, &id);
657 *uid = make_kuid(nfsd_user_namespace(rqstp), id);
658 if (!uid_valid(*uid))
659 status = nfserr_badowner;
660 return status;
661 }
662
663 __be32
664 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
665 kgid_t *gid)
666 {
667 __be32 status;
668 u32 id = -1;
669
670 if (name == NULL || namelen == 0)
671 return nfserr_inval;
672
673 status = do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, &id);
674 *gid = make_kgid(nfsd_user_namespace(rqstp), id);
675 if (!gid_valid(*gid))
676 status = nfserr_badowner;
677 return status;
678 }
679
680 __be32 nfsd4_encode_user(struct xdr_stream *xdr, struct svc_rqst *rqstp,
681 kuid_t uid)
682 {
683 u32 id = from_kuid_munged(nfsd_user_namespace(rqstp), uid);
684 return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_USER, id);
685 }
686
687 __be32 nfsd4_encode_group(struct xdr_stream *xdr, struct svc_rqst *rqstp,
688 kgid_t gid)
689 {
690 u32 id = from_kgid_munged(nfsd_user_namespace(rqstp), gid);
691 return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_GROUP, id);
692 }
693
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