net: update consumers of MSG_MORE to recognize MSG_SENDPAGE_NOTLAST
[linux-3.10.git] / crypto / crypto_user.c
1 /*
2  * Crypto user configuration API.
3  *
4  * Copyright (C) 2011 secunet Security Networks AG
5  * Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19  */
20
21 #include <linux/module.h>
22 #include <linux/crypto.h>
23 #include <linux/cryptouser.h>
24 #include <linux/sched.h>
25 #include <net/netlink.h>
26 #include <linux/security.h>
27 #include <net/net_namespace.h>
28 #include <crypto/internal/aead.h>
29 #include <crypto/internal/skcipher.h>
30
31 #include "internal.h"
32
33 #define null_terminated(x)      (strnlen(x, sizeof(x)) < sizeof(x))
34
35 static DEFINE_MUTEX(crypto_cfg_mutex);
36
37 /* The crypto netlink socket */
38 static struct sock *crypto_nlsk;
39
40 struct crypto_dump_info {
41         struct sk_buff *in_skb;
42         struct sk_buff *out_skb;
43         u32 nlmsg_seq;
44         u16 nlmsg_flags;
45 };
46
47 static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)
48 {
49         struct crypto_alg *q, *alg = NULL;
50
51         down_read(&crypto_alg_sem);
52
53         list_for_each_entry(q, &crypto_alg_list, cra_list) {
54                 int match = 0;
55
56                 if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
57                         continue;
58
59                 if (strlen(p->cru_driver_name))
60                         match = !strcmp(q->cra_driver_name,
61                                         p->cru_driver_name);
62                 else if (!exact)
63                         match = !strcmp(q->cra_name, p->cru_name);
64
65                 if (match) {
66                         alg = q;
67                         break;
68                 }
69         }
70
71         up_read(&crypto_alg_sem);
72
73         return alg;
74 }
75
76 static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
77 {
78         struct crypto_report_cipher rcipher;
79
80         strncpy(rcipher.type, "cipher", sizeof(rcipher.type));
81
82         rcipher.blocksize = alg->cra_blocksize;
83         rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
84         rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
85
86         if (nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
87                     sizeof(struct crypto_report_cipher), &rcipher))
88                 goto nla_put_failure;
89         return 0;
90
91 nla_put_failure:
92         return -EMSGSIZE;
93 }
94
95 static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
96 {
97         struct crypto_report_comp rcomp;
98
99         strncpy(rcomp.type, "compression", sizeof(rcomp.type));
100         if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
101                     sizeof(struct crypto_report_comp), &rcomp))
102                 goto nla_put_failure;
103         return 0;
104
105 nla_put_failure:
106         return -EMSGSIZE;
107 }
108
109 static int crypto_report_one(struct crypto_alg *alg,
110                              struct crypto_user_alg *ualg, struct sk_buff *skb)
111 {
112         strncpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
113         strncpy(ualg->cru_driver_name, alg->cra_driver_name,
114                 sizeof(ualg->cru_driver_name));
115         strncpy(ualg->cru_module_name, module_name(alg->cra_module),
116                 sizeof(ualg->cru_module_name));
117
118         ualg->cru_type = 0;
119         ualg->cru_mask = 0;
120         ualg->cru_flags = alg->cra_flags;
121         ualg->cru_refcnt = atomic_read(&alg->cra_refcnt);
122
123         if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
124                 goto nla_put_failure;
125         if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
126                 struct crypto_report_larval rl;
127
128                 strncpy(rl.type, "larval", sizeof(rl.type));
129                 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL,
130                             sizeof(struct crypto_report_larval), &rl))
131                         goto nla_put_failure;
132                 goto out;
133         }
134
135         if (alg->cra_type && alg->cra_type->report) {
136                 if (alg->cra_type->report(skb, alg))
137                         goto nla_put_failure;
138
139                 goto out;
140         }
141
142         switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
143         case CRYPTO_ALG_TYPE_CIPHER:
144                 if (crypto_report_cipher(skb, alg))
145                         goto nla_put_failure;
146
147                 break;
148         case CRYPTO_ALG_TYPE_COMPRESS:
149                 if (crypto_report_comp(skb, alg))
150                         goto nla_put_failure;
151
152                 break;
153         }
154
155 out:
156         return 0;
157
158 nla_put_failure:
159         return -EMSGSIZE;
160 }
161
162 static int crypto_report_alg(struct crypto_alg *alg,
163                              struct crypto_dump_info *info)
164 {
165         struct sk_buff *in_skb = info->in_skb;
166         struct sk_buff *skb = info->out_skb;
167         struct nlmsghdr *nlh;
168         struct crypto_user_alg *ualg;
169         int err = 0;
170
171         nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
172                         CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
173         if (!nlh) {
174                 err = -EMSGSIZE;
175                 goto out;
176         }
177
178         ualg = nlmsg_data(nlh);
179
180         err = crypto_report_one(alg, ualg, skb);
181         if (err) {
182                 nlmsg_cancel(skb, nlh);
183                 goto out;
184         }
185
186         nlmsg_end(skb, nlh);
187
188 out:
189         return err;
190 }
191
192 static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
193                          struct nlattr **attrs)
194 {
195         struct crypto_user_alg *p = nlmsg_data(in_nlh);
196         struct crypto_alg *alg;
197         struct sk_buff *skb;
198         struct crypto_dump_info info;
199         int err;
200
201         if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
202                 return -EINVAL;
203
204         if (!p->cru_driver_name[0])
205                 return -EINVAL;
206
207         alg = crypto_alg_match(p, 1);
208         if (!alg)
209                 return -ENOENT;
210
211         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
212         if (!skb)
213                 return -ENOMEM;
214
215         info.in_skb = in_skb;
216         info.out_skb = skb;
217         info.nlmsg_seq = in_nlh->nlmsg_seq;
218         info.nlmsg_flags = 0;
219
220         err = crypto_report_alg(alg, &info);
221         if (err)
222                 return err;
223
224         return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
225 }
226
227 static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
228 {
229         struct crypto_alg *alg;
230         struct crypto_dump_info info;
231         int err;
232
233         if (cb->args[0])
234                 goto out;
235
236         cb->args[0] = 1;
237
238         info.in_skb = cb->skb;
239         info.out_skb = skb;
240         info.nlmsg_seq = cb->nlh->nlmsg_seq;
241         info.nlmsg_flags = NLM_F_MULTI;
242
243         list_for_each_entry(alg, &crypto_alg_list, cra_list) {
244                 err = crypto_report_alg(alg, &info);
245                 if (err)
246                         goto out_err;
247         }
248
249 out:
250         return skb->len;
251 out_err:
252         return err;
253 }
254
255 static int crypto_dump_report_done(struct netlink_callback *cb)
256 {
257         return 0;
258 }
259
260 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
261                              struct nlattr **attrs)
262 {
263         struct crypto_alg *alg;
264         struct crypto_user_alg *p = nlmsg_data(nlh);
265         struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
266         LIST_HEAD(list);
267
268         if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
269                 return -EINVAL;
270
271         if (priority && !strlen(p->cru_driver_name))
272                 return -EINVAL;
273
274         alg = crypto_alg_match(p, 1);
275         if (!alg)
276                 return -ENOENT;
277
278         down_write(&crypto_alg_sem);
279
280         crypto_remove_spawns(alg, &list, NULL);
281
282         if (priority)
283                 alg->cra_priority = nla_get_u32(priority);
284
285         up_write(&crypto_alg_sem);
286
287         crypto_remove_final(&list);
288
289         return 0;
290 }
291
292 static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
293                           struct nlattr **attrs)
294 {
295         struct crypto_alg *alg;
296         struct crypto_user_alg *p = nlmsg_data(nlh);
297
298         if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
299                 return -EINVAL;
300
301         alg = crypto_alg_match(p, 1);
302         if (!alg)
303                 return -ENOENT;
304
305         /* We can not unregister core algorithms such as aes-generic.
306          * We would loose the reference in the crypto_alg_list to this algorithm
307          * if we try to unregister. Unregistering such an algorithm without
308          * removing the module is not possible, so we restrict to crypto
309          * instances that are build from templates. */
310         if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
311                 return -EINVAL;
312
313         if (atomic_read(&alg->cra_refcnt) != 1)
314                 return -EBUSY;
315
316         return crypto_unregister_instance(alg);
317 }
318
319 static struct crypto_alg *crypto_user_skcipher_alg(const char *name, u32 type,
320                                                    u32 mask)
321 {
322         int err;
323         struct crypto_alg *alg;
324
325         type = crypto_skcipher_type(type);
326         mask = crypto_skcipher_mask(mask);
327
328         for (;;) {
329                 alg = crypto_lookup_skcipher(name,  type, mask);
330                 if (!IS_ERR(alg))
331                         return alg;
332
333                 err = PTR_ERR(alg);
334                 if (err != -EAGAIN)
335                         break;
336                 if (signal_pending(current)) {
337                         err = -EINTR;
338                         break;
339                 }
340         }
341
342         return ERR_PTR(err);
343 }
344
345 static struct crypto_alg *crypto_user_aead_alg(const char *name, u32 type,
346                                                u32 mask)
347 {
348         int err;
349         struct crypto_alg *alg;
350
351         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
352         type |= CRYPTO_ALG_TYPE_AEAD;
353         mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
354         mask |= CRYPTO_ALG_TYPE_MASK;
355
356         for (;;) {
357                 alg = crypto_lookup_aead(name,  type, mask);
358                 if (!IS_ERR(alg))
359                         return alg;
360
361                 err = PTR_ERR(alg);
362                 if (err != -EAGAIN)
363                         break;
364                 if (signal_pending(current)) {
365                         err = -EINTR;
366                         break;
367                 }
368         }
369
370         return ERR_PTR(err);
371 }
372
373 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
374                           struct nlattr **attrs)
375 {
376         int exact = 0;
377         const char *name;
378         struct crypto_alg *alg;
379         struct crypto_user_alg *p = nlmsg_data(nlh);
380         struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
381
382         if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
383                 return -EINVAL;
384
385         if (strlen(p->cru_driver_name))
386                 exact = 1;
387
388         if (priority && !exact)
389                 return -EINVAL;
390
391         alg = crypto_alg_match(p, exact);
392         if (alg)
393                 return -EEXIST;
394
395         if (strlen(p->cru_driver_name))
396                 name = p->cru_driver_name;
397         else
398                 name = p->cru_name;
399
400         switch (p->cru_type & p->cru_mask & CRYPTO_ALG_TYPE_MASK) {
401         case CRYPTO_ALG_TYPE_AEAD:
402                 alg = crypto_user_aead_alg(name, p->cru_type, p->cru_mask);
403                 break;
404         case CRYPTO_ALG_TYPE_GIVCIPHER:
405         case CRYPTO_ALG_TYPE_BLKCIPHER:
406         case CRYPTO_ALG_TYPE_ABLKCIPHER:
407                 alg = crypto_user_skcipher_alg(name, p->cru_type, p->cru_mask);
408                 break;
409         default:
410                 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
411         }
412
413         if (IS_ERR(alg))
414                 return PTR_ERR(alg);
415
416         down_write(&crypto_alg_sem);
417
418         if (priority)
419                 alg->cra_priority = nla_get_u32(priority);
420
421         up_write(&crypto_alg_sem);
422
423         crypto_mod_put(alg);
424
425         return 0;
426 }
427
428 #define MSGSIZE(type) sizeof(struct type)
429
430 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
431         [CRYPTO_MSG_NEWALG      - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
432         [CRYPTO_MSG_DELALG      - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
433         [CRYPTO_MSG_UPDATEALG   - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
434         [CRYPTO_MSG_GETALG      - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
435 };
436
437 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
438         [CRYPTOCFGA_PRIORITY_VAL]   = { .type = NLA_U32},
439 };
440
441 #undef MSGSIZE
442
443 static const struct crypto_link {
444         int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
445         int (*dump)(struct sk_buff *, struct netlink_callback *);
446         int (*done)(struct netlink_callback *);
447 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
448         [CRYPTO_MSG_NEWALG      - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
449         [CRYPTO_MSG_DELALG      - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
450         [CRYPTO_MSG_UPDATEALG   - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
451         [CRYPTO_MSG_GETALG      - CRYPTO_MSG_BASE] = { .doit = crypto_report,
452                                                        .dump = crypto_dump_report,
453                                                        .done = crypto_dump_report_done},
454 };
455
456 static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
457 {
458         struct nlattr *attrs[CRYPTOCFGA_MAX+1];
459         const struct crypto_link *link;
460         int type, err;
461
462         type = nlh->nlmsg_type;
463         if (type > CRYPTO_MSG_MAX)
464                 return -EINVAL;
465
466         type -= CRYPTO_MSG_BASE;
467         link = &crypto_dispatch[type];
468
469         if (!capable(CAP_NET_ADMIN))
470                 return -EPERM;
471
472         if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
473             (nlh->nlmsg_flags & NLM_F_DUMP))) {
474                 struct crypto_alg *alg;
475                 u16 dump_alloc = 0;
476
477                 if (link->dump == NULL)
478                         return -EINVAL;
479
480                 list_for_each_entry(alg, &crypto_alg_list, cra_list)
481                         dump_alloc += CRYPTO_REPORT_MAXSIZE;
482
483                 {
484                         struct netlink_dump_control c = {
485                                 .dump = link->dump,
486                                 .done = link->done,
487                                 .min_dump_alloc = dump_alloc,
488                         };
489                         return netlink_dump_start(crypto_nlsk, skb, nlh, &c);
490                 }
491         }
492
493         err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX,
494                           crypto_policy);
495         if (err < 0)
496                 return err;
497
498         if (link->doit == NULL)
499                 return -EINVAL;
500
501         return link->doit(skb, nlh, attrs);
502 }
503
504 static void crypto_netlink_rcv(struct sk_buff *skb)
505 {
506         mutex_lock(&crypto_cfg_mutex);
507         netlink_rcv_skb(skb, &crypto_user_rcv_msg);
508         mutex_unlock(&crypto_cfg_mutex);
509 }
510
511 static int __init crypto_user_init(void)
512 {
513         struct netlink_kernel_cfg cfg = {
514                 .input  = crypto_netlink_rcv,
515         };
516
517         crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg);
518         if (!crypto_nlsk)
519                 return -ENOMEM;
520
521         return 0;
522 }
523
524 static void __exit crypto_user_exit(void)
525 {
526         netlink_kernel_release(crypto_nlsk);
527 }
528
529 module_init(crypto_user_init);
530 module_exit(crypto_user_exit);
531 MODULE_LICENSE("GPL");
532 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
533 MODULE_DESCRIPTION("Crypto userspace configuration API");