Root/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 "idmap.h"
40#include "nfsd.h"
41
42/*
43 * Cache entry
44 */
45
46/*
47 * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
48 * that.
49 */
50
51#define IDMAP_TYPE_USER 0
52#define IDMAP_TYPE_GROUP 1
53
54struct ent {
55    struct cache_head h;
56    int type; /* User / Group */
57    uid_t id;
58    char name[IDMAP_NAMESZ];
59    char authname[IDMAP_NAMESZ];
60};
61
62/* Common entry handling */
63
64#define ENT_HASHBITS 8
65#define ENT_HASHMAX (1 << ENT_HASHBITS)
66
67static void
68ent_init(struct cache_head *cnew, struct cache_head *citm)
69{
70    struct ent *new = container_of(cnew, struct ent, h);
71    struct ent *itm = container_of(citm, struct ent, h);
72
73    new->id = itm->id;
74    new->type = itm->type;
75
76    strlcpy(new->name, itm->name, sizeof(new->name));
77    strlcpy(new->authname, itm->authname, sizeof(new->name));
78}
79
80static void
81ent_put(struct kref *ref)
82{
83    struct ent *map = container_of(ref, struct ent, h.ref);
84    kfree(map);
85}
86
87static struct cache_head *
88ent_alloc(void)
89{
90    struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
91    if (e)
92        return &e->h;
93    else
94        return NULL;
95}
96
97/*
98 * ID -> Name cache
99 */
100
101static struct cache_head *idtoname_table[ENT_HASHMAX];
102
103static uint32_t
104idtoname_hash(struct ent *ent)
105{
106    uint32_t hash;
107
108    hash = hash_str(ent->authname, ENT_HASHBITS);
109    hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
110
111    /* Flip LSB for user/group */
112    if (ent->type == IDMAP_TYPE_GROUP)
113        hash ^= 1;
114
115    return hash;
116}
117
118static void
119idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
120    int *blen)
121{
122     struct ent *ent = container_of(ch, struct ent, h);
123    char idstr[11];
124
125    qword_add(bpp, blen, ent->authname);
126    snprintf(idstr, sizeof(idstr), "%u", ent->id);
127    qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
128    qword_add(bpp, blen, idstr);
129
130    (*bpp)[-1] = '\n';
131}
132
133static int
134idtoname_upcall(struct cache_detail *cd, struct cache_head *ch)
135{
136    return sunrpc_cache_pipe_upcall(cd, ch, idtoname_request);
137}
138
139static int
140idtoname_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
149static int
150idtoname_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
168static void
169warn_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
176static int idtoname_parse(struct cache_detail *, char *, int);
177static struct ent *idtoname_lookup(struct ent *);
178static struct ent *idtoname_update(struct ent *, struct ent *);
179
180static struct cache_detail idtoname_cache = {
181    .owner = THIS_MODULE,
182    .hash_size = ENT_HASHMAX,
183    .hash_table = idtoname_table,
184    .name = "nfs4.idtoname",
185    .cache_put = ent_put,
186    .cache_upcall = idtoname_upcall,
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
196static int
197idtoname_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    if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
216        goto out;
217    memcpy(ent.authname, buf1, sizeof(ent.authname));
218
219    /* Type */
220    if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
221        goto out;
222    ent.type = strcmp(buf1, "user") == 0 ?
223        IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
224
225    /* ID */
226    if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
227        goto out;
228    ent.id = simple_strtoul(buf1, &bp, 10);
229    if (bp == buf1)
230        goto out;
231
232    /* expiry */
233    ent.h.expiry_time = get_expiry(&buf);
234    if (ent.h.expiry_time == 0)
235        goto out;
236
237    error = -ENOMEM;
238    res = idtoname_lookup(&ent);
239    if (!res)
240        goto out;
241
242    /* Name */
243    error = -EINVAL;
244    len = qword_get(&buf, buf1, PAGE_SIZE);
245    if (len < 0)
246        goto out;
247    if (len == 0)
248        set_bit(CACHE_NEGATIVE, &ent.h.flags);
249    else if (len >= IDMAP_NAMESZ)
250        goto out;
251    else
252        memcpy(ent.name, buf1, sizeof(ent.name));
253    error = -ENOMEM;
254    res = idtoname_update(&ent, res);
255    if (res == NULL)
256        goto out;
257
258    cache_put(&res->h, &idtoname_cache);
259
260    error = 0;
261out:
262    kfree(buf1);
263
264    return error;
265}
266
267
268static struct ent *
269idtoname_lookup(struct ent *item)
270{
271    struct cache_head *ch = sunrpc_cache_lookup(&idtoname_cache,
272                            &item->h,
273                            idtoname_hash(item));
274    if (ch)
275        return container_of(ch, struct ent, h);
276    else
277        return NULL;
278}
279
280static struct ent *
281idtoname_update(struct ent *new, struct ent *old)
282{
283    struct cache_head *ch = sunrpc_cache_update(&idtoname_cache,
284                            &new->h, &old->h,
285                            idtoname_hash(new));
286    if (ch)
287        return container_of(ch, struct ent, h);
288    else
289        return NULL;
290}
291
292
293/*
294 * Name -> ID cache
295 */
296
297static struct cache_head *nametoid_table[ENT_HASHMAX];
298
299static inline int
300nametoid_hash(struct ent *ent)
301{
302    return hash_str(ent->name, ENT_HASHBITS);
303}
304
305static void
306nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
307    int *blen)
308{
309     struct ent *ent = container_of(ch, struct ent, h);
310
311    qword_add(bpp, blen, ent->authname);
312    qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
313    qword_add(bpp, blen, ent->name);
314
315    (*bpp)[-1] = '\n';
316}
317
318static int
319nametoid_upcall(struct cache_detail *cd, struct cache_head *ch)
320{
321    return sunrpc_cache_pipe_upcall(cd, ch, nametoid_request);
322}
323
324static int
325nametoid_match(struct cache_head *ca, struct cache_head *cb)
326{
327    struct ent *a = container_of(ca, struct ent, h);
328    struct ent *b = container_of(cb, struct ent, h);
329
330    return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
331        strcmp(a->authname, b->authname) == 0);
332}
333
334static int
335nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
336{
337    struct ent *ent;
338
339    if (h == NULL) {
340        seq_puts(m, "#domain type name [id]\n");
341        return 0;
342    }
343    ent = container_of(h, struct ent, h);
344    seq_printf(m, "%s %s %s", ent->authname,
345            ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
346            ent->name);
347    if (test_bit(CACHE_VALID, &h->flags))
348        seq_printf(m, " %u", ent->id);
349    seq_printf(m, "\n");
350    return 0;
351}
352
353static struct ent *nametoid_lookup(struct ent *);
354static struct ent *nametoid_update(struct ent *, struct ent *);
355static int nametoid_parse(struct cache_detail *, char *, int);
356
357static struct cache_detail nametoid_cache = {
358    .owner = THIS_MODULE,
359    .hash_size = ENT_HASHMAX,
360    .hash_table = nametoid_table,
361    .name = "nfs4.nametoid",
362    .cache_put = ent_put,
363    .cache_upcall = nametoid_upcall,
364    .cache_parse = nametoid_parse,
365    .cache_show = nametoid_show,
366    .warn_no_listener = warn_no_idmapd,
367    .match = nametoid_match,
368    .init = ent_init,
369    .update = ent_init,
370    .alloc = ent_alloc,
371};
372
373static int
374nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
375{
376    struct ent ent, *res;
377    char *buf1;
378    int error = -EINVAL;
379
380    if (buf[buflen - 1] != '\n')
381        return (-EINVAL);
382    buf[buflen - 1]= '\0';
383
384    buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
385    if (buf1 == NULL)
386        return (-ENOMEM);
387
388    memset(&ent, 0, sizeof(ent));
389
390    /* Authentication name */
391    if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
392        goto out;
393    memcpy(ent.authname, buf1, sizeof(ent.authname));
394
395    /* Type */
396    if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
397        goto out;
398    ent.type = strcmp(buf1, "user") == 0 ?
399        IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
400
401    /* Name */
402    error = qword_get(&buf, buf1, PAGE_SIZE);
403    if (error <= 0 || error >= IDMAP_NAMESZ)
404        goto out;
405    memcpy(ent.name, buf1, sizeof(ent.name));
406
407    /* expiry */
408    ent.h.expiry_time = get_expiry(&buf);
409    if (ent.h.expiry_time == 0)
410        goto out;
411
412    /* ID */
413    error = get_int(&buf, &ent.id);
414    if (error == -EINVAL)
415        goto out;
416    if (error == -ENOENT)
417        set_bit(CACHE_NEGATIVE, &ent.h.flags);
418
419    error = -ENOMEM;
420    res = nametoid_lookup(&ent);
421    if (res == NULL)
422        goto out;
423    res = nametoid_update(&ent, res);
424    if (res == NULL)
425        goto out;
426
427    cache_put(&res->h, &nametoid_cache);
428    error = 0;
429out:
430    kfree(buf1);
431
432    return (error);
433}
434
435
436static struct ent *
437nametoid_lookup(struct ent *item)
438{
439    struct cache_head *ch = sunrpc_cache_lookup(&nametoid_cache,
440                            &item->h,
441                            nametoid_hash(item));
442    if (ch)
443        return container_of(ch, struct ent, h);
444    else
445        return NULL;
446}
447
448static struct ent *
449nametoid_update(struct ent *new, struct ent *old)
450{
451    struct cache_head *ch = sunrpc_cache_update(&nametoid_cache,
452                            &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
464int
465nfsd_idmap_init(void)
466{
467    int rv;
468
469    rv = cache_register(&idtoname_cache);
470    if (rv)
471        return rv;
472    rv = cache_register(&nametoid_cache);
473    if (rv)
474        cache_unregister(&idtoname_cache);
475    return rv;
476}
477
478void
479nfsd_idmap_shutdown(void)
480{
481    cache_unregister(&idtoname_cache);
482    cache_unregister(&nametoid_cache);
483}
484
485static int
486idmap_lookup(struct svc_rqst *rqstp,
487        struct ent *(*lookup_fn)(struct ent *), struct ent *key,
488        struct cache_detail *detail, struct ent **item)
489{
490    int ret;
491
492    *item = lookup_fn(key);
493    if (!*item)
494        return -ENOMEM;
495 retry:
496    ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
497
498    if (ret == -ETIMEDOUT) {
499        struct ent *prev_item = *item;
500        *item = lookup_fn(key);
501        if (*item != prev_item)
502            goto retry;
503        cache_put(&(*item)->h, detail);
504    }
505    return ret;
506}
507
508static char *
509rqst_authname(struct svc_rqst *rqstp)
510{
511    struct auth_domain *clp;
512
513    clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
514    return clp->name;
515}
516
517static __be32
518idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
519        uid_t *id)
520{
521    struct ent *item, key = {
522        .type = type,
523    };
524    int ret;
525
526    if (namelen + 1 > sizeof(key.name))
527        return nfserr_badowner;
528    memcpy(key.name, name, namelen);
529    key.name[namelen] = '\0';
530    strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
531    ret = idmap_lookup(rqstp, nametoid_lookup, &key, &nametoid_cache, &item);
532    if (ret == -ENOENT)
533        return nfserr_badowner;
534    if (ret)
535        return nfserrno(ret);
536    *id = item->id;
537    cache_put(&item->h, &nametoid_cache);
538    return 0;
539}
540
541static int
542idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
543{
544    struct ent *item, key = {
545        .id = id,
546        .type = type,
547    };
548    int ret;
549
550    strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
551    ret = idmap_lookup(rqstp, idtoname_lookup, &key, &idtoname_cache, &item);
552    if (ret == -ENOENT)
553        return sprintf(name, "%u", id);
554    if (ret)
555        return ret;
556    ret = strlen(item->name);
557    BUG_ON(ret > IDMAP_NAMESZ);
558    memcpy(name, item->name, ret);
559    cache_put(&item->h, &idtoname_cache);
560    return ret;
561}
562
563__be32
564nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
565        __u32 *id)
566{
567    return idmap_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
568}
569
570__be32
571nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
572        __u32 *id)
573{
574    return idmap_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
575}
576
577int
578nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
579{
580    return idmap_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
581}
582
583int
584nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
585{
586    return idmap_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
587}
588

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