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[mirror_ubuntu-bionic-kernel.git] / fs / nfsd / nfs4idmap.c
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
45 /*
46 * Turn off idmapping when using AUTH_SYS.
47 */
48 static bool nfs4_disable_idmapping = true;
49 module_param(nfs4_disable_idmapping, bool, 0644);
50 MODULE_PARM_DESC(nfs4_disable_idmapping,
51 "Turn off server's NFSv4 idmapping when using 'sec=sys'");
52
53 /*
54 * Cache entry
55 */
56
57 /*
58 * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
59 * that.
60 */
61
62 struct ent {
63 struct cache_head h;
64 int type; /* User / Group */
65 u32 id;
66 char name[IDMAP_NAMESZ];
67 char authname[IDMAP_NAMESZ];
68 };
69
70 /* Common entry handling */
71
72 #define ENT_HASHBITS 8
73 #define ENT_HASHMAX (1 << ENT_HASHBITS)
74
75 static void
76 ent_init(struct cache_head *cnew, struct cache_head *citm)
77 {
78 struct ent *new = container_of(cnew, struct ent, h);
79 struct ent *itm = container_of(citm, struct ent, h);
80
81 new->id = itm->id;
82 new->type = itm->type;
83
84 strlcpy(new->name, itm->name, sizeof(new->name));
85 strlcpy(new->authname, itm->authname, sizeof(new->name));
86 }
87
88 static void
89 ent_put(struct kref *ref)
90 {
91 struct ent *map = container_of(ref, struct ent, h.ref);
92 kfree(map);
93 }
94
95 static struct cache_head *
96 ent_alloc(void)
97 {
98 struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
99 if (e)
100 return &e->h;
101 else
102 return NULL;
103 }
104
105 /*
106 * ID -> Name cache
107 */
108
109 static uint32_t
110 idtoname_hash(struct ent *ent)
111 {
112 uint32_t hash;
113
114 hash = hash_str(ent->authname, ENT_HASHBITS);
115 hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
116
117 /* Flip LSB for user/group */
118 if (ent->type == IDMAP_TYPE_GROUP)
119 hash ^= 1;
120
121 return hash;
122 }
123
124 static void
125 idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
126 int *blen)
127 {
128 struct ent *ent = container_of(ch, struct ent, h);
129 char idstr[11];
130
131 qword_add(bpp, blen, ent->authname);
132 snprintf(idstr, sizeof(idstr), "%u", ent->id);
133 qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
134 qword_add(bpp, blen, idstr);
135
136 (*bpp)[-1] = '\n';
137 }
138
139 static int
140 idtoname_match(struct cache_head *ca, struct cache_head *cb)
141 {
142 struct ent *a = container_of(ca, struct ent, h);
143 struct ent *b = container_of(cb, struct ent, h);
144
145 return (a->id == b->id && a->type == b->type &&
146 strcmp(a->authname, b->authname) == 0);
147 }
148
149 static int
150 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
151 {
152 struct ent *ent;
153
154 if (h == NULL) {
155 seq_puts(m, "#domain type id [name]\n");
156 return 0;
157 }
158 ent = container_of(h, struct ent, h);
159 seq_printf(m, "%s %s %u", ent->authname,
160 ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
161 ent->id);
162 if (test_bit(CACHE_VALID, &h->flags))
163 seq_printf(m, " %s", ent->name);
164 seq_printf(m, "\n");
165 return 0;
166 }
167
168 static void
169 warn_no_idmapd(struct cache_detail *detail, int has_died)
170 {
171 printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
172 has_died ? "died" : "not been started");
173 }
174
175
176 static int idtoname_parse(struct cache_detail *, char *, int);
177 static struct ent *idtoname_lookup(struct cache_detail *, struct ent *);
178 static struct ent *idtoname_update(struct cache_detail *, struct ent *,
179 struct ent *);
180
181 static struct cache_detail idtoname_cache_template = {
182 .owner = THIS_MODULE,
183 .hash_size = ENT_HASHMAX,
184 .name = "nfs4.idtoname",
185 .cache_put = ent_put,
186 .cache_request = idtoname_request,
187 .cache_parse = idtoname_parse,
188 .cache_show = idtoname_show,
189 .warn_no_listener = warn_no_idmapd,
190 .match = idtoname_match,
191 .init = ent_init,
192 .update = ent_init,
193 .alloc = ent_alloc,
194 };
195
196 static int
197 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
198 {
199 struct ent ent, *res;
200 char *buf1, *bp;
201 int len;
202 int error = -EINVAL;
203
204 if (buf[buflen - 1] != '\n')
205 return (-EINVAL);
206 buf[buflen - 1]= '\0';
207
208 buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
209 if (buf1 == NULL)
210 return (-ENOMEM);
211
212 memset(&ent, 0, sizeof(ent));
213
214 /* Authentication name */
215 len = qword_get(&buf, buf1, PAGE_SIZE);
216 if (len <= 0 || len >= IDMAP_NAMESZ)
217 goto out;
218 memcpy(ent.authname, buf1, sizeof(ent.authname));
219
220 /* Type */
221 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
222 goto out;
223 ent.type = strcmp(buf1, "user") == 0 ?
224 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
225
226 /* ID */
227 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
228 goto out;
229 ent.id = simple_strtoul(buf1, &bp, 10);
230 if (bp == buf1)
231 goto out;
232
233 /* expiry */
234 ent.h.expiry_time = get_expiry(&buf);
235 if (ent.h.expiry_time == 0)
236 goto out;
237
238 error = -ENOMEM;
239 res = idtoname_lookup(cd, &ent);
240 if (!res)
241 goto out;
242
243 /* Name */
244 error = -EINVAL;
245 len = qword_get(&buf, buf1, PAGE_SIZE);
246 if (len < 0 || len >= IDMAP_NAMESZ)
247 goto out;
248 if (len == 0)
249 set_bit(CACHE_NEGATIVE, &ent.h.flags);
250 else
251 memcpy(ent.name, buf1, sizeof(ent.name));
252 error = -ENOMEM;
253 res = idtoname_update(cd, &ent, res);
254 if (res == NULL)
255 goto out;
256
257 cache_put(&res->h, cd);
258 error = 0;
259 out:
260 kfree(buf1);
261 return error;
262 }
263
264 static struct ent *
265 idtoname_lookup(struct cache_detail *cd, struct ent *item)
266 {
267 struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
268 idtoname_hash(item));
269 if (ch)
270 return container_of(ch, struct ent, h);
271 else
272 return NULL;
273 }
274
275 static struct ent *
276 idtoname_update(struct cache_detail *cd, struct ent *new, struct ent *old)
277 {
278 struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
279 idtoname_hash(new));
280 if (ch)
281 return container_of(ch, struct ent, h);
282 else
283 return NULL;
284 }
285
286
287 /*
288 * Name -> ID cache
289 */
290
291 static inline int
292 nametoid_hash(struct ent *ent)
293 {
294 return hash_str(ent->name, ENT_HASHBITS);
295 }
296
297 static void
298 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
299 int *blen)
300 {
301 struct ent *ent = container_of(ch, struct ent, h);
302
303 qword_add(bpp, blen, ent->authname);
304 qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
305 qword_add(bpp, blen, ent->name);
306
307 (*bpp)[-1] = '\n';
308 }
309
310 static int
311 nametoid_match(struct cache_head *ca, struct cache_head *cb)
312 {
313 struct ent *a = container_of(ca, struct ent, h);
314 struct ent *b = container_of(cb, struct ent, h);
315
316 return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
317 strcmp(a->authname, b->authname) == 0);
318 }
319
320 static int
321 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
322 {
323 struct ent *ent;
324
325 if (h == NULL) {
326 seq_puts(m, "#domain type name [id]\n");
327 return 0;
328 }
329 ent = container_of(h, struct ent, h);
330 seq_printf(m, "%s %s %s", ent->authname,
331 ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
332 ent->name);
333 if (test_bit(CACHE_VALID, &h->flags))
334 seq_printf(m, " %u", ent->id);
335 seq_printf(m, "\n");
336 return 0;
337 }
338
339 static struct ent *nametoid_lookup(struct cache_detail *, struct ent *);
340 static struct ent *nametoid_update(struct cache_detail *, struct ent *,
341 struct ent *);
342 static int nametoid_parse(struct cache_detail *, char *, int);
343
344 static struct cache_detail nametoid_cache_template = {
345 .owner = THIS_MODULE,
346 .hash_size = ENT_HASHMAX,
347 .name = "nfs4.nametoid",
348 .cache_put = ent_put,
349 .cache_request = nametoid_request,
350 .cache_parse = nametoid_parse,
351 .cache_show = nametoid_show,
352 .warn_no_listener = warn_no_idmapd,
353 .match = nametoid_match,
354 .init = ent_init,
355 .update = ent_init,
356 .alloc = ent_alloc,
357 };
358
359 static int
360 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
361 {
362 struct ent ent, *res;
363 char *buf1;
364 int len, error = -EINVAL;
365
366 if (buf[buflen - 1] != '\n')
367 return (-EINVAL);
368 buf[buflen - 1]= '\0';
369
370 buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
371 if (buf1 == NULL)
372 return (-ENOMEM);
373
374 memset(&ent, 0, sizeof(ent));
375
376 /* Authentication name */
377 len = qword_get(&buf, buf1, PAGE_SIZE);
378 if (len <= 0 || len >= IDMAP_NAMESZ)
379 goto out;
380 memcpy(ent.authname, buf1, sizeof(ent.authname));
381
382 /* Type */
383 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
384 goto out;
385 ent.type = strcmp(buf1, "user") == 0 ?
386 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
387
388 /* Name */
389 len = qword_get(&buf, buf1, PAGE_SIZE);
390 if (len <= 0 || len >= IDMAP_NAMESZ)
391 goto out;
392 memcpy(ent.name, buf1, sizeof(ent.name));
393
394 /* expiry */
395 ent.h.expiry_time = get_expiry(&buf);
396 if (ent.h.expiry_time == 0)
397 goto out;
398
399 /* ID */
400 error = get_int(&buf, &ent.id);
401 if (error == -EINVAL)
402 goto out;
403 if (error == -ENOENT)
404 set_bit(CACHE_NEGATIVE, &ent.h.flags);
405
406 error = -ENOMEM;
407 res = nametoid_lookup(cd, &ent);
408 if (res == NULL)
409 goto out;
410 res = nametoid_update(cd, &ent, res);
411 if (res == NULL)
412 goto out;
413
414 cache_put(&res->h, cd);
415 error = 0;
416 out:
417 kfree(buf1);
418 return (error);
419 }
420
421
422 static struct ent *
423 nametoid_lookup(struct cache_detail *cd, struct ent *item)
424 {
425 struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
426 nametoid_hash(item));
427 if (ch)
428 return container_of(ch, struct ent, h);
429 else
430 return NULL;
431 }
432
433 static struct ent *
434 nametoid_update(struct cache_detail *cd, struct ent *new, struct ent *old)
435 {
436 struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
437 nametoid_hash(new));
438 if (ch)
439 return container_of(ch, struct ent, h);
440 else
441 return NULL;
442 }
443
444 /*
445 * Exported API
446 */
447
448 int
449 nfsd_idmap_init(struct net *net)
450 {
451 int rv;
452 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
453
454 nn->idtoname_cache = cache_create_net(&idtoname_cache_template, net);
455 if (IS_ERR(nn->idtoname_cache))
456 return PTR_ERR(nn->idtoname_cache);
457 rv = cache_register_net(nn->idtoname_cache, net);
458 if (rv)
459 goto destroy_idtoname_cache;
460 nn->nametoid_cache = cache_create_net(&nametoid_cache_template, net);
461 if (IS_ERR(nn->nametoid_cache)) {
462 rv = PTR_ERR(nn->nametoid_cache);
463 goto unregister_idtoname_cache;
464 }
465 rv = cache_register_net(nn->nametoid_cache, net);
466 if (rv)
467 goto destroy_nametoid_cache;
468 return 0;
469
470 destroy_nametoid_cache:
471 cache_destroy_net(nn->nametoid_cache, net);
472 unregister_idtoname_cache:
473 cache_unregister_net(nn->idtoname_cache, net);
474 destroy_idtoname_cache:
475 cache_destroy_net(nn->idtoname_cache, net);
476 return rv;
477 }
478
479 void
480 nfsd_idmap_shutdown(struct net *net)
481 {
482 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
483
484 cache_unregister_net(nn->idtoname_cache, net);
485 cache_unregister_net(nn->nametoid_cache, net);
486 cache_destroy_net(nn->idtoname_cache, net);
487 cache_destroy_net(nn->nametoid_cache, net);
488 }
489
490 static int
491 idmap_lookup(struct svc_rqst *rqstp,
492 struct ent *(*lookup_fn)(struct cache_detail *, struct ent *),
493 struct ent *key, struct cache_detail *detail, struct ent **item)
494 {
495 int ret;
496
497 *item = lookup_fn(detail, key);
498 if (!*item)
499 return -ENOMEM;
500 retry:
501 ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
502
503 if (ret == -ETIMEDOUT) {
504 struct ent *prev_item = *item;
505 *item = lookup_fn(detail, key);
506 if (*item != prev_item)
507 goto retry;
508 cache_put(&(*item)->h, detail);
509 }
510 return ret;
511 }
512
513 static char *
514 rqst_authname(struct svc_rqst *rqstp)
515 {
516 struct auth_domain *clp;
517
518 clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
519 return clp->name;
520 }
521
522 static __be32
523 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
524 u32 *id)
525 {
526 struct ent *item, key = {
527 .type = type,
528 };
529 int ret;
530 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
531
532 if (namelen + 1 > sizeof(key.name))
533 return nfserr_badowner;
534 memcpy(key.name, name, namelen);
535 key.name[namelen] = '\0';
536 strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
537 ret = idmap_lookup(rqstp, nametoid_lookup, &key, nn->nametoid_cache, &item);
538 if (ret == -ENOENT)
539 return nfserr_badowner;
540 if (ret)
541 return nfserrno(ret);
542 *id = item->id;
543 cache_put(&item->h, nn->nametoid_cache);
544 return 0;
545 }
546
547 static __be32 encode_ascii_id(struct xdr_stream *xdr, u32 id)
548 {
549 char buf[11];
550 int len;
551 __be32 *p;
552
553 len = sprintf(buf, "%u", id);
554 p = xdr_reserve_space(xdr, len + 4);
555 if (!p)
556 return nfserr_resource;
557 p = xdr_encode_opaque(p, buf, len);
558 return 0;
559 }
560
561 static __be32 idmap_id_to_name(struct xdr_stream *xdr,
562 struct svc_rqst *rqstp, int type, u32 id)
563 {
564 struct ent *item, key = {
565 .id = id,
566 .type = type,
567 };
568 __be32 *p;
569 int ret;
570 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
571
572 strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
573 ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item);
574 if (ret == -ENOENT)
575 return encode_ascii_id(xdr, id);
576 if (ret)
577 return nfserrno(ret);
578 ret = strlen(item->name);
579 WARN_ON_ONCE(ret > IDMAP_NAMESZ);
580 p = xdr_reserve_space(xdr, ret + 4);
581 if (!p)
582 return nfserr_resource;
583 p = xdr_encode_opaque(p, item->name, ret);
584 cache_put(&item->h, nn->idtoname_cache);
585 return 0;
586 }
587
588 static bool
589 numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
590 {
591 int ret;
592 char buf[11];
593
594 if (namelen + 1 > sizeof(buf))
595 /* too long to represent a 32-bit id: */
596 return false;
597 /* Just to make sure it's null-terminated: */
598 memcpy(buf, name, namelen);
599 buf[namelen] = '\0';
600 ret = kstrtouint(buf, 10, id);
601 return ret == 0;
602 }
603
604 static __be32
605 do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
606 {
607 if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
608 if (numeric_name_to_id(rqstp, type, name, namelen, id))
609 return 0;
610 /*
611 * otherwise, fall through and try idmapping, for
612 * backwards compatibility with clients sending names:
613 */
614 return idmap_name_to_id(rqstp, type, name, namelen, id);
615 }
616
617 static __be32 encode_name_from_id(struct xdr_stream *xdr,
618 struct svc_rqst *rqstp, int type, u32 id)
619 {
620 if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
621 return encode_ascii_id(xdr, id);
622 return idmap_id_to_name(xdr, rqstp, type, id);
623 }
624
625 __be32
626 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
627 kuid_t *uid)
628 {
629 __be32 status;
630 u32 id = -1;
631 status = do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, &id);
632 *uid = make_kuid(&init_user_ns, id);
633 if (!uid_valid(*uid))
634 status = nfserr_badowner;
635 return status;
636 }
637
638 __be32
639 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
640 kgid_t *gid)
641 {
642 __be32 status;
643 u32 id = -1;
644 status = do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, &id);
645 *gid = make_kgid(&init_user_ns, id);
646 if (!gid_valid(*gid))
647 status = nfserr_badowner;
648 return status;
649 }
650
651 __be32 nfsd4_encode_user(struct xdr_stream *xdr, struct svc_rqst *rqstp,
652 kuid_t uid)
653 {
654 u32 id = from_kuid(&init_user_ns, uid);
655 return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_USER, id);
656 }
657
658 __be32 nfsd4_encode_group(struct xdr_stream *xdr, struct svc_rqst *rqstp,
659 kgid_t gid)
660 {
661 u32 id = from_kgid(&init_user_ns, gid);
662 return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_GROUP, id);
663 }