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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 */
48static bool nfs4_disable_idmapping = true;
49module_param(nfs4_disable_idmapping, bool, 0644);
50MODULE_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
65struct ent {
66 struct cache_head h;
67 int type; /* User / Group */
68 uid_t 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
78static void
79ent_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
91static void
92ent_put(struct kref *ref)
93{
94 struct ent *map = container_of(ref, struct ent, h.ref);
95 kfree(map);
96}
97
98static struct cache_head *
99ent_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
112static uint32_t
113idtoname_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
127static void
128idtoname_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
142static int
143idtoname_upcall(struct cache_detail *cd, struct cache_head *ch)
144{
145 return sunrpc_cache_pipe_upcall(cd, ch, idtoname_request);
146}
147
148static int
149idtoname_match(struct cache_head *ca, struct cache_head *cb)
150{
151 struct ent *a = container_of(ca, struct ent, h);
152 struct ent *b = container_of(cb, struct ent, h);
153
154 return (a->id == b->id && a->type == b->type &&
155 strcmp(a->authname, b->authname) == 0);
156}
157
158static int
159idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
160{
161 struct ent *ent;
162
163 if (h == NULL) {
164 seq_puts(m, "#domain type id [name]\n");
165 return 0;
166 }
167 ent = container_of(h, struct ent, h);
168 seq_printf(m, "%s %s %u", ent->authname,
169 ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
170 ent->id);
171 if (test_bit(CACHE_VALID, &h->flags))
172 seq_printf(m, " %s", ent->name);
173 seq_printf(m, "\n");
174 return 0;
175}
176
177static void
178warn_no_idmapd(struct cache_detail *detail, int has_died)
179{
180 printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
181 has_died ? "died" : "not been started");
182}
183
184
185static int idtoname_parse(struct cache_detail *, char *, int);
186static struct ent *idtoname_lookup(struct cache_detail *, struct ent *);
187static struct ent *idtoname_update(struct cache_detail *, struct ent *,
188 struct ent *);
189
190static struct cache_detail idtoname_cache_template = {
191 .owner = THIS_MODULE,
192 .hash_size = ENT_HASHMAX,
193 .name = "nfs4.idtoname",
194 .cache_put = ent_put,
195 .cache_upcall = idtoname_upcall,
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
205static int
206idtoname_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 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
225 goto out;
226 memcpy(ent.authname, buf1, sizeof(ent.authname));
227
228 /* Type */
229 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
230 goto out;
231 ent.type = strcmp(buf1, "user") == 0 ?
232 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
233
234 /* ID */
235 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
236 goto out;
237 ent.id = simple_strtoul(buf1, &bp, 10);
238 if (bp == buf1)
239 goto out;
240
241 /* expiry */
242 ent.h.expiry_time = get_expiry(&buf);
243 if (ent.h.expiry_time == 0)
244 goto out;
245
246 error = -ENOMEM;
247 res = idtoname_lookup(cd, &ent);
248 if (!res)
249 goto out;
250
251 /* Name */
252 error = -EINVAL;
253 len = qword_get(&buf, buf1, PAGE_SIZE);
254 if (len < 0)
255 goto out;
256 if (len == 0)
257 set_bit(CACHE_NEGATIVE, &ent.h.flags);
258 else if (len >= IDMAP_NAMESZ)
259 goto out;
260 else
261 memcpy(ent.name, buf1, sizeof(ent.name));
262 error = -ENOMEM;
263 res = idtoname_update(cd, &ent, res);
264 if (res == NULL)
265 goto out;
266
267 cache_put(&res->h, cd);
268
269 error = 0;
270out:
271 kfree(buf1);
272
273 return error;
274}
275
276
277static struct ent *
278idtoname_lookup(struct cache_detail *cd, struct ent *item)
279{
280 struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
281 idtoname_hash(item));
282 if (ch)
283 return container_of(ch, struct ent, h);
284 else
285 return NULL;
286}
287
288static struct ent *
289idtoname_update(struct cache_detail *cd, struct ent *new, struct ent *old)
290{
291 struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
292 idtoname_hash(new));
293 if (ch)
294 return container_of(ch, struct ent, h);
295 else
296 return NULL;
297}
298
299
300/*
301 * Name -> ID cache
302 */
303
304static inline int
305nametoid_hash(struct ent *ent)
306{
307 return hash_str(ent->name, ENT_HASHBITS);
308}
309
310static void
311nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
312 int *blen)
313{
314 struct ent *ent = container_of(ch, struct ent, h);
315
316 qword_add(bpp, blen, ent->authname);
317 qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
318 qword_add(bpp, blen, ent->name);
319
320 (*bpp)[-1] = '\n';
321}
322
323static int
324nametoid_upcall(struct cache_detail *cd, struct cache_head *ch)
325{
326 return sunrpc_cache_pipe_upcall(cd, ch, nametoid_request);
327}
328
329static int
330nametoid_match(struct cache_head *ca, struct cache_head *cb)
331{
332 struct ent *a = container_of(ca, struct ent, h);
333 struct ent *b = container_of(cb, struct ent, h);
334
335 return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
336 strcmp(a->authname, b->authname) == 0);
337}
338
339static int
340nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
341{
342 struct ent *ent;
343
344 if (h == NULL) {
345 seq_puts(m, "#domain type name [id]\n");
346 return 0;
347 }
348 ent = container_of(h, struct ent, h);
349 seq_printf(m, "%s %s %s", ent->authname,
350 ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
351 ent->name);
352 if (test_bit(CACHE_VALID, &h->flags))
353 seq_printf(m, " %u", ent->id);
354 seq_printf(m, "\n");
355 return 0;
356}
357
358static struct ent *nametoid_lookup(struct cache_detail *, struct ent *);
359static struct ent *nametoid_update(struct cache_detail *, struct ent *,
360 struct ent *);
361static int nametoid_parse(struct cache_detail *, char *, int);
362
363static struct cache_detail nametoid_cache_template = {
364 .owner = THIS_MODULE,
365 .hash_size = ENT_HASHMAX,
366 .name = "nfs4.nametoid",
367 .cache_put = ent_put,
368 .cache_upcall = nametoid_upcall,
369 .cache_parse = nametoid_parse,
370 .cache_show = nametoid_show,
371 .warn_no_listener = warn_no_idmapd,
372 .match = nametoid_match,
373 .init = ent_init,
374 .update = ent_init,
375 .alloc = ent_alloc,
376};
377
378static int
379nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
380{
381 struct ent ent, *res;
382 char *buf1;
383 int error = -EINVAL;
384
385 if (buf[buflen - 1] != '\n')
386 return (-EINVAL);
387 buf[buflen - 1]= '\0';
388
389 buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
390 if (buf1 == NULL)
391 return (-ENOMEM);
392
393 memset(&ent, 0, sizeof(ent));
394
395 /* Authentication name */
396 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
397 goto out;
398 memcpy(ent.authname, buf1, sizeof(ent.authname));
399
400 /* Type */
401 if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
402 goto out;
403 ent.type = strcmp(buf1, "user") == 0 ?
404 IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
405
406 /* Name */
407 error = qword_get(&buf, buf1, PAGE_SIZE);
408 if (error <= 0 || error >= IDMAP_NAMESZ)
409 goto out;
410 memcpy(ent.name, buf1, sizeof(ent.name));
411
412 /* expiry */
413 ent.h.expiry_time = get_expiry(&buf);
414 if (ent.h.expiry_time == 0)
415 goto out;
416
417 /* ID */
418 error = get_int(&buf, &ent.id);
419 if (error == -EINVAL)
420 goto out;
421 if (error == -ENOENT)
422 set_bit(CACHE_NEGATIVE, &ent.h.flags);
423
424 error = -ENOMEM;
425 res = nametoid_lookup(cd, &ent);
426 if (res == NULL)
427 goto out;
428 res = nametoid_update(cd, &ent, res);
429 if (res == NULL)
430 goto out;
431
432 cache_put(&res->h, cd);
433 error = 0;
434out:
435 kfree(buf1);
436
437 return (error);
438}
439
440
441static struct ent *
442nametoid_lookup(struct cache_detail *cd, struct ent *item)
443{
444 struct cache_head *ch = sunrpc_cache_lookup(cd, &item->h,
445 nametoid_hash(item));
446 if (ch)
447 return container_of(ch, struct ent, h);
448 else
449 return NULL;
450}
451
452static struct ent *
453nametoid_update(struct cache_detail *cd, struct ent *new, struct ent *old)
454{
455 struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
456 nametoid_hash(new));
457 if (ch)
458 return container_of(ch, struct ent, h);
459 else
460 return NULL;
461}
462
463/*
464 * Exported API
465 */
466
467int
468nfsd_idmap_init(struct net *net)
469{
470 int rv;
471 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
472
473 nn->idtoname_cache = cache_create_net(&idtoname_cache_template, net);
474 if (IS_ERR(nn->idtoname_cache))
475 return PTR_ERR(nn->idtoname_cache);
476 rv = cache_register_net(nn->idtoname_cache, net);
477 if (rv)
478 goto destroy_idtoname_cache;
479 nn->nametoid_cache = cache_create_net(&nametoid_cache_template, net);
480 if (IS_ERR(nn->nametoid_cache)) {
481 rv = PTR_ERR(nn->idtoname_cache);
482 goto unregister_idtoname_cache;
483 }
484 rv = cache_register_net(nn->nametoid_cache, net);
485 if (rv)
486 goto destroy_nametoid_cache;
487 return 0;
488
489destroy_nametoid_cache:
490 cache_destroy_net(nn->nametoid_cache, net);
491unregister_idtoname_cache:
492 cache_unregister_net(nn->idtoname_cache, net);
493destroy_idtoname_cache:
494 cache_destroy_net(nn->idtoname_cache, net);
495 return rv;
496}
497
498void
499nfsd_idmap_shutdown(struct net *net)
500{
501 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
502
503 cache_unregister_net(nn->idtoname_cache, net);
504 cache_unregister_net(nn->nametoid_cache, net);
505 cache_destroy_net(nn->idtoname_cache, net);
506 cache_destroy_net(nn->nametoid_cache, net);
507}
508
509static int
510idmap_lookup(struct svc_rqst *rqstp,
511 struct ent *(*lookup_fn)(struct cache_detail *, struct ent *),
512 struct ent *key, struct cache_detail *detail, struct ent **item)
513{
514 int ret;
515
516 *item = lookup_fn(detail, key);
517 if (!*item)
518 return -ENOMEM;
519 retry:
520 ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
521
522 if (ret == -ETIMEDOUT) {
523 struct ent *prev_item = *item;
524 *item = lookup_fn(detail, key);
525 if (*item != prev_item)
526 goto retry;
527 cache_put(&(*item)->h, detail);
528 }
529 return ret;
530}
531
532static char *
533rqst_authname(struct svc_rqst *rqstp)
534{
535 struct auth_domain *clp;
536
537 clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
538 return clp->name;
539}
540
541static __be32
542idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
543 uid_t *id)
544{
545 struct ent *item, key = {
546 .type = type,
547 };
548 int ret;
549 struct nfsd_net *nn = net_generic(rqstp->rq_xprt->xpt_net, nfsd_net_id);
550
551 if (namelen + 1 > sizeof(key.name))
552 return nfserr_badowner;
553 memcpy(key.name, name, namelen);
554 key.name[namelen] = '\0';
555 strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
556 ret = idmap_lookup(rqstp, nametoid_lookup, &key, nn->nametoid_cache, &item);
557 if (ret == -ENOENT)
558 return nfserr_badowner;
559 if (ret)
560 return nfserrno(ret);
561 *id = item->id;
562 cache_put(&item->h, nn->nametoid_cache);
563 return 0;
564}
565
566static int
567idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
568{
569 struct ent *item, key = {
570 .id = id,
571 .type = type,
572 };
573 int ret;
574 struct nfsd_net *nn = net_generic(rqstp->rq_xprt->xpt_net, nfsd_net_id);
575
576 strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
577 ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item);
578 if (ret == -ENOENT)
579 return sprintf(name, "%u", id);
580 if (ret)
581 return ret;
582 ret = strlen(item->name);
583 BUG_ON(ret > IDMAP_NAMESZ);
584 memcpy(name, item->name, ret);
585 cache_put(&item->h, nn->idtoname_cache);
586 return ret;
587}
588
589static bool
590numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, uid_t *id)
591{
592 int ret;
593 char buf[11];
594
595 if (namelen + 1 > sizeof(buf))
596 /* too long to represent a 32-bit id: */
597 return false;
598 /* Just to make sure it's null-terminated: */
599 memcpy(buf, name, namelen);
600 buf[namelen] = '\0';
601 ret = kstrtouint(name, 10, id);
602 return ret == 0;
603}
604
605static __be32
606do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, uid_t *id)
607{
608 if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
609 if (numeric_name_to_id(rqstp, type, name, namelen, id))
610 return 0;
611 /*
612 * otherwise, fall through and try idmapping, for
613 * backwards compatibility with clients sending names:
614 */
615 return idmap_name_to_id(rqstp, type, name, namelen, id);
616}
617
618static int
619do_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
620{
621 if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
622 return sprintf(name, "%u", id);
623 return idmap_id_to_name(rqstp, type, id, name);
624}
625
626__be32
627nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
628 __u32 *id)
629{
630 return do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
631}
632
633__be32
634nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
635 __u32 *id)
636{
637 return do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
638}
639
640int
641nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
642{
643 return do_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
644}
645
646int
647nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
648{
649 return do_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
650}