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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 #define IDMAP_TYPE_USER 0
63 #define IDMAP_TYPE_GROUP 1
64
65 struct ent {
66 struct cache_head h;
67 int type; /* User / Group */
68 u32 id;
69 char name[IDMAP_NAMESZ];
70 char authname[IDMAP_NAMESZ];
71 };
72
73 /* Common entry handling */
74
75 #define ENT_HASHBITS 8
76 #define ENT_HASHMAX (1 << ENT_HASHBITS)
77
78 static void
79 ent_init(struct cache_head *cnew, struct cache_head *citm)
80 {
81 struct ent *new = container_of(cnew, struct ent, h);
82 struct ent *itm = container_of(citm, struct ent, h);
83
84 new->id = itm->id;
85 new->type = itm->type;
86
87 strlcpy(new->name, itm->name, sizeof(new->name));
88 strlcpy(new->authname, itm->authname, sizeof(new->name));
89 }
90
91 static void
92 ent_put(struct kref *ref)
93 {
94 struct ent *map = container_of(ref, struct ent, h.ref);
95 kfree(map);
96 }
97
98 static struct cache_head *
99 ent_alloc(void)
100 {
101 struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
102 if (e)
103 return &e->h;
104 else
105 return NULL;
106 }
107
108 /*
109 * ID -> Name cache
110 */
111
112 static uint32_t
113 idtoname_hash(struct ent *ent)
114 {
115 uint32_t hash;
116
117 hash = hash_str(ent->authname, ENT_HASHBITS);
118 hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
119
120 /* Flip LSB for user/group */
121 if (ent->type == IDMAP_TYPE_GROUP)
122 hash ^= 1;
123
124 return hash;
125 }
126
127 static void
128 idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
129 int *blen)
130 {
131 struct ent *ent = container_of(ch, struct ent, h);
132 char idstr[11];
133
134 qword_add(bpp, blen, ent->authname);
135 snprintf(idstr, sizeof(idstr), "%u", ent->id);
136 qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
137 qword_add(bpp, blen, idstr);
138
139 (*bpp)[-1] = '\n';
140 }
141
142 static int
143 idtoname_match(struct cache_head *ca, struct cache_head *cb)
144 {
145 struct ent *a = container_of(ca, struct ent, h);
146 struct ent *b = container_of(cb, struct ent, h);
147
148 return (a->id == b->id && a->type == b->type &&
149 strcmp(a->authname, b->authname) == 0);
150 }
151
152 static int
153 idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
154 {
155 struct ent *ent;
156
157 if (h == NULL) {
158 seq_puts(m, "#domain type id [name]\n");
159 return 0;
160 }
161 ent = container_of(h, struct ent, h);
162 seq_printf(m, "%s %s %u", ent->authname,
163 ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
164 ent->id);
165 if (test_bit(CACHE_VALID, &h->flags))
166 seq_printf(m, " %s", ent->name);
167 seq_printf(m, "\n");
168 return 0;
169 }
170
171 static void
172 warn_no_idmapd(struct cache_detail *detail, int has_died)
173 {
174 printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
175 has_died ? "died" : "not been started");
176 }
177
178
179 static int idtoname_parse(struct cache_detail *, char *, int);
180 static struct ent *idtoname_lookup(struct cache_detail *, struct ent *);
181 static struct ent *idtoname_update(struct cache_detail *, struct ent *,
182 struct ent *);
183
184 static struct cache_detail idtoname_cache_template = {
185 .owner = THIS_MODULE,
186 .hash_size = ENT_HASHMAX,
187 .name = "nfs4.idtoname",
188 .cache_put = ent_put,
189 .cache_request = idtoname_request,
190 .cache_parse = idtoname_parse,
191 .cache_show = idtoname_show,
192 .warn_no_listener = warn_no_idmapd,
193 .match = idtoname_match,
194 .init = ent_init,
195 .update = ent_init,
196 .alloc = ent_alloc,
197 };
198
199 static int
200 idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
201 {
202 struct ent ent, *res;
203 char *buf1, *bp;
204 int len;
205 int error = -EINVAL;
206
207 if (buf[buflen - 1] != '\n')
208 return (-EINVAL);
209 buf[buflen - 1]= '\0';
210
211 buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
212 if (buf1 == NULL)
213 return (-ENOMEM);
214
215 memset(&ent, 0, sizeof(ent));
216
217 /* Authentication name */
218 len = qword_get(&buf, buf1, PAGE_SIZE);
219 if (len <= 0 || len >= IDMAP_NAMESZ)
220 goto out;
221 memcpy(ent.authname, buf1, sizeof(ent.authname));
222
223 /* Type */
224 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
225 goto out;
226 ent.type = strcmp(buf1, "user") == 0 ?
227 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
228
229 /* ID */
230 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
231 goto out;
232 ent.id = simple_strtoul(buf1, &bp, 10);
233 if (bp == buf1)
234 goto out;
235
236 /* expiry */
237 ent.h.expiry_time = get_expiry(&buf);
238 if (ent.h.expiry_time == 0)
239 goto out;
240
241 error = -ENOMEM;
242 res = idtoname_lookup(cd, &ent);
243 if (!res)
244 goto out;
245
246 /* Name */
247 error = -EINVAL;
248 len = qword_get(&buf, buf1, PAGE_SIZE);
249 if (len < 0 || len >= IDMAP_NAMESZ)
250 goto out;
251 if (len == 0)
252 set_bit(CACHE_NEGATIVE, &ent.h.flags);
253 else
254 memcpy(ent.name, buf1, sizeof(ent.name));
255 error = -ENOMEM;
256 res = idtoname_update(cd, &ent, res);
257 if (res == NULL)
258 goto out;
259
260 cache_put(&res->h, cd);
261 error = 0;
262 out:
263 kfree(buf1);
264 return error;
265 }
266
267 static struct ent *
268 idtoname_lookup(struct cache_detail *cd, struct ent *item)
269 {
270 struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
271 idtoname_hash(item));
272 if (ch)
273 return container_of(ch, struct ent, h);
274 else
275 return NULL;
276 }
277
278 static struct ent *
279 idtoname_update(struct cache_detail *cd, struct ent *new, struct ent *old)
280 {
281 struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
282 idtoname_hash(new));
283 if (ch)
284 return container_of(ch, struct ent, h);
285 else
286 return NULL;
287 }
288
289
290 /*
291 * Name -> ID cache
292 */
293
294 static inline int
295 nametoid_hash(struct ent *ent)
296 {
297 return hash_str(ent->name, ENT_HASHBITS);
298 }
299
300 static void
301 nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
302 int *blen)
303 {
304 struct ent *ent = container_of(ch, struct ent, h);
305
306 qword_add(bpp, blen, ent->authname);
307 qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
308 qword_add(bpp, blen, ent->name);
309
310 (*bpp)[-1] = '\n';
311 }
312
313 static int
314 nametoid_match(struct cache_head *ca, struct cache_head *cb)
315 {
316 struct ent *a = container_of(ca, struct ent, h);
317 struct ent *b = container_of(cb, struct ent, h);
318
319 return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
320 strcmp(a->authname, b->authname) == 0);
321 }
322
323 static int
324 nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
325 {
326 struct ent *ent;
327
328 if (h == NULL) {
329 seq_puts(m, "#domain type name [id]\n");
330 return 0;
331 }
332 ent = container_of(h, struct ent, h);
333 seq_printf(m, "%s %s %s", ent->authname,
334 ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
335 ent->name);
336 if (test_bit(CACHE_VALID, &h->flags))
337 seq_printf(m, " %u", ent->id);
338 seq_printf(m, "\n");
339 return 0;
340 }
341
342 static struct ent *nametoid_lookup(struct cache_detail *, struct ent *);
343 static struct ent *nametoid_update(struct cache_detail *, struct ent *,
344 struct ent *);
345 static int nametoid_parse(struct cache_detail *, char *, int);
346
347 static struct cache_detail nametoid_cache_template = {
348 .owner = THIS_MODULE,
349 .hash_size = ENT_HASHMAX,
350 .name = "nfs4.nametoid",
351 .cache_put = ent_put,
352 .cache_request = nametoid_request,
353 .cache_parse = nametoid_parse,
354 .cache_show = nametoid_show,
355 .warn_no_listener = warn_no_idmapd,
356 .match = nametoid_match,
357 .init = ent_init,
358 .update = ent_init,
359 .alloc = ent_alloc,
360 };
361
362 static int
363 nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
364 {
365 struct ent ent, *res;
366 char *buf1;
367 int len, error = -EINVAL;
368
369 if (buf[buflen - 1] != '\n')
370 return (-EINVAL);
371 buf[buflen - 1]= '\0';
372
373 buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
374 if (buf1 == NULL)
375 return (-ENOMEM);
376
377 memset(&ent, 0, sizeof(ent));
378
379 /* Authentication name */
380 len = qword_get(&buf, buf1, PAGE_SIZE);
381 if (len <= 0 || len >= IDMAP_NAMESZ)
382 goto out;
383 memcpy(ent.authname, buf1, sizeof(ent.authname));
384
385 /* Type */
386 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
387 goto out;
388 ent.type = strcmp(buf1, "user") == 0 ?
389 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
390
391 /* Name */
392 len = qword_get(&buf, buf1, PAGE_SIZE);
393 if (len <= 0 || len >= IDMAP_NAMESZ)
394 goto out;
395 memcpy(ent.name, buf1, sizeof(ent.name));
396
397 /* expiry */
398 ent.h.expiry_time = get_expiry(&buf);
399 if (ent.h.expiry_time == 0)
400 goto out;
401
402 /* ID */
403 error = get_int(&buf, &ent.id);
404 if (error == -EINVAL)
405 goto out;
406 if (error == -ENOENT)
407 set_bit(CACHE_NEGATIVE, &ent.h.flags);
408
409 error = -ENOMEM;
410 res = nametoid_lookup(cd, &ent);
411 if (res == NULL)
412 goto out;
413 res = nametoid_update(cd, &ent, res);
414 if (res == NULL)
415 goto out;
416
417 cache_put(&res->h, cd);
418 error = 0;
419 out:
420 kfree(buf1);
421 return (error);
422 }
423
424
425 static struct ent *
426 nametoid_lookup(struct cache_detail *cd, struct ent *item)
427 {
428 struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
429 nametoid_hash(item));
430 if (ch)
431 return container_of(ch, struct ent, h);
432 else
433 return NULL;
434 }
435
436 static struct ent *
437 nametoid_update(struct cache_detail *cd, struct ent *new, struct ent *old)
438 {
439 struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
440 nametoid_hash(new));
441 if (ch)
442 return container_of(ch, struct ent, h);
443 else
444 return NULL;
445 }
446
447 /*
448 * Exported API
449 */
450
451 int
452 nfsd_idmap_init(struct net *net)
453 {
454 int rv;
455 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
456
457 nn->idtoname_cache = cache_create_net(&idtoname_cache_template, net);
458 if (IS_ERR(nn->idtoname_cache))
459 return PTR_ERR(nn->idtoname_cache);
460 rv = cache_register_net(nn->idtoname_cache, net);
461 if (rv)
462 goto destroy_idtoname_cache;
463 nn->nametoid_cache = cache_create_net(&nametoid_cache_template, net);
464 if (IS_ERR(nn->nametoid_cache)) {
465 rv = PTR_ERR(nn->nametoid_cache);
466 goto unregister_idtoname_cache;
467 }
468 rv = cache_register_net(nn->nametoid_cache, net);
469 if (rv)
470 goto destroy_nametoid_cache;
471 return 0;
472
473 destroy_nametoid_cache:
474 cache_destroy_net(nn->nametoid_cache, net);
475 unregister_idtoname_cache:
476 cache_unregister_net(nn->idtoname_cache, net);
477 destroy_idtoname_cache:
478 cache_destroy_net(nn->idtoname_cache, net);
479 return rv;
480 }
481
482 void
483 nfsd_idmap_shutdown(struct net *net)
484 {
485 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
486
487 cache_unregister_net(nn->idtoname_cache, net);
488 cache_unregister_net(nn->nametoid_cache, net);
489 cache_destroy_net(nn->idtoname_cache, net);
490 cache_destroy_net(nn->nametoid_cache, net);
491 }
492
493 static int
494 idmap_lookup(struct svc_rqst *rqstp,
495 struct ent *(*lookup_fn)(struct cache_detail *, struct ent *),
496 struct ent *key, struct cache_detail *detail, struct ent **item)
497 {
498 int ret;
499
500 *item = lookup_fn(detail, key);
501 if (!*item)
502 return -ENOMEM;
503 retry:
504 ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
505
506 if (ret == -ETIMEDOUT) {
507 struct ent *prev_item = *item;
508 *item = lookup_fn(detail, key);
509 if (*item != prev_item)
510 goto retry;
511 cache_put(&(*item)->h, detail);
512 }
513 return ret;
514 }
515
516 static char *
517 rqst_authname(struct svc_rqst *rqstp)
518 {
519 struct auth_domain *clp;
520
521 clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
522 return clp->name;
523 }
524
525 static __be32
526 idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
527 u32 *id)
528 {
529 struct ent *item, key = {
530 .type = type,
531 };
532 int ret;
533 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
534
535 if (namelen + 1 > sizeof(key.name))
536 return nfserr_badowner;
537 memcpy(key.name, name, namelen);
538 key.name[namelen] = '\0';
539 strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
540 ret = idmap_lookup(rqstp, nametoid_lookup, &key, nn->nametoid_cache, &item);
541 if (ret == -ENOENT)
542 return nfserr_badowner;
543 if (ret)
544 return nfserrno(ret);
545 *id = item->id;
546 cache_put(&item->h, nn->nametoid_cache);
547 return 0;
548 }
549
550 static __be32 encode_ascii_id(struct xdr_stream *xdr, u32 id)
551 {
552 char buf[11];
553 int len;
554 __be32 *p;
555
556 len = sprintf(buf, "%u", id);
557 p = xdr_reserve_space(xdr, len + 4);
558 if (!p)
559 return nfserr_resource;
560 p = xdr_encode_opaque(p, buf, len);
561 return 0;
562 }
563
564 static __be32 idmap_id_to_name(struct xdr_stream *xdr,
565 struct svc_rqst *rqstp, int type, u32 id)
566 {
567 struct ent *item, key = {
568 .id = id,
569 .type = type,
570 };
571 __be32 *p;
572 int ret;
573 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
574
575 strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
576 ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item);
577 if (ret == -ENOENT)
578 return encode_ascii_id(xdr, id);
579 if (ret)
580 return nfserrno(ret);
581 ret = strlen(item->name);
582 WARN_ON_ONCE(ret > IDMAP_NAMESZ);
583 p = xdr_reserve_space(xdr, ret + 4);
584 if (!p)
585 return nfserr_resource;
586 p = xdr_encode_opaque(p, item->name, ret);
587 cache_put(&item->h, nn->idtoname_cache);
588 return 0;
589 }
590
591 static bool
592 numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
593 {
594 int ret;
595 char buf[11];
596
597 if (namelen + 1 > sizeof(buf))
598 /* too long to represent a 32-bit id: */
599 return false;
600 /* Just to make sure it's null-terminated: */
601 memcpy(buf, name, namelen);
602 buf[namelen] = '\0';
603 ret = kstrtouint(buf, 10, id);
604 return ret == 0;
605 }
606
607 static __be32
608 do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
609 {
610 if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
611 if (numeric_name_to_id(rqstp, type, name, namelen, id))
612 return 0;
613 /*
614 * otherwise, fall through and try idmapping, for
615 * backwards compatibility with clients sending names:
616 */
617 return idmap_name_to_id(rqstp, type, name, namelen, id);
618 }
619
620 static __be32 encode_name_from_id(struct xdr_stream *xdr,
621 struct svc_rqst *rqstp, int type, u32 id)
622 {
623 if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
624 return encode_ascii_id(xdr, id);
625 return idmap_id_to_name(xdr, rqstp, type, id);
626 }
627
628 __be32
629 nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
630 kuid_t *uid)
631 {
632 __be32 status;
633 u32 id = -1;
634 status = do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, &id);
635 *uid = make_kuid(&init_user_ns, id);
636 if (!uid_valid(*uid))
637 status = nfserr_badowner;
638 return status;
639 }
640
641 __be32
642 nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
643 kgid_t *gid)
644 {
645 __be32 status;
646 u32 id = -1;
647 status = do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, &id);
648 *gid = make_kgid(&init_user_ns, id);
649 if (!gid_valid(*gid))
650 status = nfserr_badowner;
651 return status;
652 }
653
654 __be32 nfsd4_encode_user(struct xdr_stream *xdr, struct svc_rqst *rqstp,
655 kuid_t uid)
656 {
657 u32 id = from_kuid(&init_user_ns, uid);
658 return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_USER, id);
659 }
660
661 __be32 nfsd4_encode_group(struct xdr_stream *xdr, struct svc_rqst *rqstp,
662 kgid_t gid)
663 {
664 u32 id = from_kgid(&init_user_ns, gid);
665 return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_GROUP, id);
666 }