[linux.git] / crypto / crypto_user.c

/*
 * Crypto user configuration API.
 *
 * Copyright (C) 2011 secunet Security Networks AG
 * Copyright (C) 2011 Steffen Klassert <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <linux/module.h>
#include <linux/crypto.h>
#include <linux/cryptouser.h>
#include <net/netlink.h>
#include <linux/security.h>
#include <net/net_namespace.h>
#include "internal.h"

DEFINE_MUTEX(crypto_cfg_mutex);

/* The crypto netlink socket */
static struct sock *crypto_nlsk;

struct crypto_dump_info {
	struct sk_buff *in_skb;
	struct sk_buff *out_skb;
	u32 nlmsg_seq;
	u16 nlmsg_flags;
};

static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)
{
	struct crypto_alg *q, *alg = NULL;

	down_read(&crypto_alg_sem);

	list_for_each_entry(q, &crypto_alg_list, cra_list) {
		int match = 0;

		if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
			continue;

		if (strlen(p->cru_driver_name))
			match = !strcmp(q->cra_driver_name,
					p->cru_driver_name);
		else if (!exact)
			match = !strcmp(q->cra_name, p->cru_name);

		if (match) {
			alg = q;
			break;
		}
	}

	up_read(&crypto_alg_sem);

	return alg;
}

static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
{
	struct crypto_report_cipher rcipher;

	snprintf(rcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "cipher");

	rcipher.blocksize = alg->cra_blocksize;
	rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
	rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;

	NLA_PUT(skb, CRYPTOCFGA_REPORT_CIPHER,
		sizeof(struct crypto_report_cipher), &rcipher);

	return 0;

nla_put_failure:
	return -EMSGSIZE;
}

static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
{
	struct crypto_report_comp rcomp;

	snprintf(rcomp.type, CRYPTO_MAX_ALG_NAME, "%s", "compression");

	NLA_PUT(skb, CRYPTOCFGA_REPORT_COMPRESS,
		sizeof(struct crypto_report_comp), &rcomp);

	return 0;

nla_put_failure:
	return -EMSGSIZE;
}

static int crypto_report_one(struct crypto_alg *alg,
			     struct crypto_user_alg *ualg, struct sk_buff *skb)
{
	memcpy(&ualg->cru_name, &alg->cra_name, sizeof(ualg->cru_name));
	memcpy(&ualg->cru_driver_name, &alg->cra_driver_name,
	       sizeof(ualg->cru_driver_name));
	memcpy(&ualg->cru_module_name, module_name(alg->cra_module),
	       CRYPTO_MAX_ALG_NAME);

	ualg->cru_flags = alg->cra_flags;
	ualg->cru_refcnt = atomic_read(&alg->cra_refcnt);

	NLA_PUT_U32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority);

	if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
		struct crypto_report_larval rl;

		snprintf(rl.type, CRYPTO_MAX_ALG_NAME, "%s", "larval");

		NLA_PUT(skb, CRYPTOCFGA_REPORT_LARVAL,
			sizeof(struct crypto_report_larval), &rl);

		goto out;
	}

	if (alg->cra_type && alg->cra_type->report) {
		if (alg->cra_type->report(skb, alg))
			goto nla_put_failure;

		goto out;
	}

	switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
	case CRYPTO_ALG_TYPE_CIPHER:
		if (crypto_report_cipher(skb, alg))
			goto nla_put_failure;

		break;
	case CRYPTO_ALG_TYPE_COMPRESS:
		if (crypto_report_comp(skb, alg))
			goto nla_put_failure;

		break;
	}

out:
	return 0;

nla_put_failure:
	return -EMSGSIZE;
}

static int crypto_report_alg(struct crypto_alg *alg,
			     struct crypto_dump_info *info)
{
	struct sk_buff *in_skb = info->in_skb;
	struct sk_buff *skb = info->out_skb;
	struct nlmsghdr *nlh;
	struct crypto_user_alg *ualg;
	int err = 0;

	nlh = nlmsg_put(skb, NETLINK_CB(in_skb).pid, info->nlmsg_seq,
			CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
	if (!nlh) {
		err = -EMSGSIZE;
		goto out;
	}

	ualg = nlmsg_data(nlh);

	err = crypto_report_one(alg, ualg, skb);
	if (err) {
		nlmsg_cancel(skb, nlh);
		goto out;
	}

	nlmsg_end(skb, nlh);

out:
	return err;
}

static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
			 struct nlattr **attrs)
{
	struct crypto_user_alg *p = nlmsg_data(in_nlh);
	struct crypto_alg *alg;
	struct sk_buff *skb;
	struct crypto_dump_info info;
	int err;

	if (!p->cru_driver_name)
		return -EINVAL;

	alg = crypto_alg_match(p, 1);
	if (!alg)
		return -ENOENT;

	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
	if (!skb)
		return -ENOMEM;

	info.in_skb = in_skb;
	info.out_skb = skb;
	info.nlmsg_seq = in_nlh->nlmsg_seq;
	info.nlmsg_flags = 0;

	err = crypto_report_alg(alg, &info);
	if (err)
		return err;

	return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).pid);
}

static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct crypto_alg *alg;
	struct crypto_dump_info info;
	int err;

	if (cb->args[0])
		goto out;

	cb->args[0] = 1;

	info.in_skb = cb->skb;
	info.out_skb = skb;
	info.nlmsg_seq = cb->nlh->nlmsg_seq;
	info.nlmsg_flags = NLM_F_MULTI;

	list_for_each_entry(alg, &crypto_alg_list, cra_list) {
		err = crypto_report_alg(alg, &info);
		if (err)
			goto out_err;
	}

out:
	return skb->len;
out_err:
	return err;
}

static int crypto_dump_report_done(struct netlink_callback *cb)
{
	return 0;
}

static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
			     struct nlattr **attrs)
{
	struct crypto_alg *alg;
	struct crypto_user_alg *p = nlmsg_data(nlh);
	struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
	LIST_HEAD(list);

	if (priority && !strlen(p->cru_driver_name))
		return -EINVAL;

	alg = crypto_alg_match(p, 1);
	if (!alg)
		return -ENOENT;

	down_write(&crypto_alg_sem);

	crypto_remove_spawns(alg, &list, NULL);

	if (priority)
		alg->cra_priority = nla_get_u32(priority);

	up_write(&crypto_alg_sem);

	crypto_remove_final(&list);

	return 0;
}

static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
			  struct nlattr **attrs)
{
	struct crypto_alg *alg;
	struct crypto_user_alg *p = nlmsg_data(nlh);

	alg = crypto_alg_match(p, 1);
	if (!alg)
		return -ENOENT;

	/* We can not unregister core algorithms such as aes-generic.
	 * We would loose the reference in the crypto_alg_list to this algorithm
	 * if we try to unregister. Unregistering such an algorithm without
	 * removing the module is not possible, so we restrict to crypto
	 * instances that are build from templates. */
	if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
		return -EINVAL;

	if (atomic_read(&alg->cra_refcnt) != 1)
		return -EBUSY;

	return crypto_unregister_instance(alg);
}

static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
			  struct nlattr **attrs)
{
	int exact = 0;
	const char *name;
	struct crypto_alg *alg;
	struct crypto_user_alg *p = nlmsg_data(nlh);
	struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];

	if (strlen(p->cru_driver_name))
		exact = 1;

	if (priority && !exact)
		return -EINVAL;

	alg = crypto_alg_match(p, exact);
	if (alg)
		return -EEXIST;

	if (strlen(p->cru_driver_name))
		name = p->cru_driver_name;
	else
		name = p->cru_name;

	alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
	if (IS_ERR(alg))
		return PTR_ERR(alg);

	down_write(&crypto_alg_sem);

	if (priority)
		alg->cra_priority = nla_get_u32(priority);

	up_write(&crypto_alg_sem);

	crypto_mod_put(alg);

	return 0;
}

#define MSGSIZE(type) sizeof(struct type)

static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
	[CRYPTO_MSG_NEWALG	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	[CRYPTO_MSG_DELALG	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	[CRYPTO_MSG_UPDATEALG	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	[CRYPTO_MSG_GETALG	- CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
};

static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
	[CRYPTOCFGA_PRIORITY_VAL]   = { .type = NLA_U32},
};

#undef MSGSIZE

static struct crypto_link {
	int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
	int (*dump)(struct sk_buff *, struct netlink_callback *);
	int (*done)(struct netlink_callback *);
} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
	[CRYPTO_MSG_NEWALG	- CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
	[CRYPTO_MSG_DELALG	- CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
	[CRYPTO_MSG_UPDATEALG	- CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
	[CRYPTO_MSG_GETALG	- CRYPTO_MSG_BASE] = { .doit = crypto_report,
						       .dump = crypto_dump_report,
						       .done = crypto_dump_report_done},
};

static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
	struct nlattr *attrs[CRYPTOCFGA_MAX+1];
	struct crypto_link *link;
	int type, err;

	type = nlh->nlmsg_type;
	if (type > CRYPTO_MSG_MAX)
		return -EINVAL;

	type -= CRYPTO_MSG_BASE;
	link = &crypto_dispatch[type];

	if (!capable(CAP_NET_ADMIN))
		return -EPERM;

	if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
	    (nlh->nlmsg_flags & NLM_F_DUMP))) {
		if (link->dump == NULL)
			return -EINVAL;
		{
			struct netlink_dump_control c = {
				.dump = link->dump,
				.done = link->done,
			};
			return netlink_dump_start(crypto_nlsk, skb, nlh, &c);
		}
	}

	err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX,
			  crypto_policy);
	if (err < 0)
		return err;

	if (link->doit == NULL)
		return -EINVAL;

	return link->doit(skb, nlh, attrs);
}

static void crypto_netlink_rcv(struct sk_buff *skb)
{
	mutex_lock(&crypto_cfg_mutex);
	netlink_rcv_skb(skb, &crypto_user_rcv_msg);
	mutex_unlock(&crypto_cfg_mutex);
}

static int __init crypto_user_init(void)
{
	crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO,
					    0, crypto_netlink_rcv,
					    NULL, THIS_MODULE);
	if (!crypto_nlsk)
		return -ENOMEM;

	return 0;
}

static void __exit crypto_user_exit(void)
{
	netlink_kernel_release(crypto_nlsk);
}

module_init(crypto_user_init);
module_exit(crypto_user_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Steffen Klassert <[email protected]>");
MODULE_DESCRIPTION("Crypto userspace configuration API");
Commit	Line	Data
a38f7907 SK	1	/*
	2	* Crypto user configuration API.
	3	*
	4	* Copyright (C) 2011 secunet Security Networks AG
	5	* Copyright (C) 2011 Steffen Klassert <[email protected]>
	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 <net/netlink.h>
	25	#include <linux/security.h>
	26	#include <net/net_namespace.h>
	27	#include "internal.h"
	28
	29	DEFINE_MUTEX(crypto_cfg_mutex);
	30
	31	/* The crypto netlink socket */
	32	static struct sock *crypto_nlsk;
	33
	34	struct crypto_dump_info {
	35	struct sk_buff *in_skb;
	36	struct sk_buff *out_skb;
	37	u32 nlmsg_seq;
	38	u16 nlmsg_flags;
	39	};
	40
	41	static struct crypto_alg crypto_alg_match(struct crypto_user_alg p, int exact)
	42	{
a38f7907 SK	43	struct crypto_alg q, alg = NULL;
	44
	45	down_read(&crypto_alg_sem);
	46
a38f7907	47	list_for_each_entry(q, &crypto_alg_list, cra_list) {
e6ea64ec	48	int match = 0;
a38f7907 SK	49
	50	if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
	51	continue;
	52
	53	if (strlen(p->cru_driver_name))
	54	match = !strcmp(q->cra_driver_name,
	55	p->cru_driver_name);
	56	else if (!exact)
	57	match = !strcmp(q->cra_name, p->cru_name);
	58
	59	if (match) {
	60	alg = q;
	61	break;
	62	}
	63	}
	64
	65	up_read(&crypto_alg_sem);
	66
	67	return alg;
	68	}
	69
07a5fa4a SK	70	static int crypto_report_cipher(struct sk_buff skb, struct crypto_alg alg)
	71	{
	72	struct crypto_report_cipher rcipher;
	73
	74	snprintf(rcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "cipher");
	75
	76	rcipher.blocksize = alg->cra_blocksize;
	77	rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
	78	rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
	79
	80	NLA_PUT(skb, CRYPTOCFGA_REPORT_CIPHER,
	81	sizeof(struct crypto_report_cipher), &rcipher);
	82
	83	return 0;
	84
	85	nla_put_failure:
	86	return -EMSGSIZE;
	87	}
	88
540b97c1 SK	89	static int crypto_report_comp(struct sk_buff skb, struct crypto_alg alg)
	90	{
	91	struct crypto_report_comp rcomp;
	92
	93	snprintf(rcomp.type, CRYPTO_MAX_ALG_NAME, "%s", "compression");
	94
	95	NLA_PUT(skb, CRYPTOCFGA_REPORT_COMPRESS,
	96	sizeof(struct crypto_report_comp), &rcomp);
	97
	98	return 0;
	99
	100	nla_put_failure:
	101	return -EMSGSIZE;
	102	}
	103
a38f7907 SK	104	static int crypto_report_one(struct crypto_alg *alg,
	105	struct crypto_user_alg ualg, struct sk_buff skb)
	106	{
	107	memcpy(&ualg->cru_name, &alg->cra_name, sizeof(ualg->cru_name));
	108	memcpy(&ualg->cru_driver_name, &alg->cra_driver_name,
	109	sizeof(ualg->cru_driver_name));
	110	memcpy(&ualg->cru_module_name, module_name(alg->cra_module),
	111	CRYPTO_MAX_ALG_NAME);
	112
	113	ualg->cru_flags = alg->cra_flags;
	114	ualg->cru_refcnt = atomic_read(&alg->cra_refcnt);
	115
	116	NLA_PUT_U32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority);
	117
6c5a86f5 SK	118	if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
	119	struct crypto_report_larval rl;
	120
	121	snprintf(rl.type, CRYPTO_MAX_ALG_NAME, "%s", "larval");
	122
	123	NLA_PUT(skb, CRYPTOCFGA_REPORT_LARVAL,
	124	sizeof(struct crypto_report_larval), &rl);
	125
	126	goto out;
	127	}
	128
b6aa63c0 SK	129	if (alg->cra_type && alg->cra_type->report) {
	130	if (alg->cra_type->report(skb, alg))
	131	goto nla_put_failure;
07a5fa4a SK	132
	133	goto out;
	134	}
	135
	136	switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK \| CRYPTO_ALG_LARVAL)) {
	137	case CRYPTO_ALG_TYPE_CIPHER:
	138	if (crypto_report_cipher(skb, alg))
	139	goto nla_put_failure;
	140
540b97c1 SK	141	break;
	142	case CRYPTO_ALG_TYPE_COMPRESS:
	143	if (crypto_report_comp(skb, alg))
	144	goto nla_put_failure;
	145
07a5fa4a	146	break;
b6aa63c0 SK	147	}
b6aa63c0 SK	148
6c5a86f5	149	out:
a38f7907 SK	150	return 0;
	151
	152	nla_put_failure:
	153	return -EMSGSIZE;
	154	}
	155
	156	static int crypto_report_alg(struct crypto_alg *alg,
	157	struct crypto_dump_info *info)
	158	{
	159	struct sk_buff *in_skb = info->in_skb;
	160	struct sk_buff *skb = info->out_skb;
	161	struct nlmsghdr *nlh;
	162	struct crypto_user_alg *ualg;
	163	int err = 0;
	164
	165	nlh = nlmsg_put(skb, NETLINK_CB(in_skb).pid, info->nlmsg_seq,
	166	CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
	167	if (!nlh) {
	168	err = -EMSGSIZE;
	169	goto out;
	170	}
	171
	172	ualg = nlmsg_data(nlh);
	173
	174	err = crypto_report_one(alg, ualg, skb);
	175	if (err) {
	176	nlmsg_cancel(skb, nlh);
	177	goto out;
	178	}
	179
	180	nlmsg_end(skb, nlh);
	181
	182	out:
	183	return err;
	184	}
	185
	186	static int crypto_report(struct sk_buff in_skb, struct nlmsghdr in_nlh,
	187	struct nlattr **attrs)
	188	{
	189	struct crypto_user_alg *p = nlmsg_data(in_nlh);
	190	struct crypto_alg *alg;
	191	struct sk_buff *skb;
	192	struct crypto_dump_info info;
	193	int err;
	194
	195	if (!p->cru_driver_name)
	196	return -EINVAL;
	197
	198	alg = crypto_alg_match(p, 1);
	199	if (!alg)
	200	return -ENOENT;
	201
	202	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
	203	if (!skb)
	204	return -ENOMEM;
	205
	206	info.in_skb = in_skb;
	207	info.out_skb = skb;
	208	info.nlmsg_seq = in_nlh->nlmsg_seq;
	209	info.nlmsg_flags = 0;
	210
	211	err = crypto_report_alg(alg, &info);
	212	if (err)
	213	return err;
214
215	return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).pid);
216	}
217
218	static int crypto_dump_report(struct sk_buff skb, struct netlink_callback cb)
219	{
220	struct crypto_alg *alg;
221	struct crypto_dump_info info;
222	int err;
223
224	if (cb->args[0])
225	goto out;
226
227	cb->args[0] = 1;
228
229	info.in_skb = cb->skb;
230	info.out_skb = skb;
231	info.nlmsg_seq = cb->nlh->nlmsg_seq;
232	info.nlmsg_flags = NLM_F_MULTI;
233
234	list_for_each_entry(alg, &crypto_alg_list, cra_list) {
235	err = crypto_report_alg(alg, &info);
236	if (err)
237	goto out_err;
238	}
239
240	out:
241	return skb->len;
242	out_err:
243	return err;
244	}
245
246	static int crypto_dump_report_done(struct netlink_callback *cb)
247	{
248	return 0;
249	}
250
251	static int crypto_update_alg(struct sk_buff skb, struct nlmsghdr nlh,
252	struct nlattr **attrs)
253	{
254	struct crypto_alg *alg;
255	struct crypto_user_alg *p = nlmsg_data(nlh);
256	struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
257	LIST_HEAD(list);
258
259	if (priority && !strlen(p->cru_driver_name))
260	return -EINVAL;
261
262	alg = crypto_alg_match(p, 1);
263	if (!alg)
264	return -ENOENT;
265
266	down_write(&crypto_alg_sem);
267
268	crypto_remove_spawns(alg, &list, NULL);
269
270	if (priority)
271	alg->cra_priority = nla_get_u32(priority);
272
273	up_write(&crypto_alg_sem);
274
275	crypto_remove_final(&list);
276
277	return 0;
278	}
279
280	static int crypto_del_alg(struct sk_buff skb, struct nlmsghdr nlh,
281	struct nlattr **attrs)
282	{
283	struct crypto_alg *alg;
284	struct crypto_user_alg *p = nlmsg_data(nlh);
285
286	alg = crypto_alg_match(p, 1);
287	if (!alg)
288	return -ENOENT;
289
290	/* We can not unregister core algorithms such as aes-generic.
291	* We would loose the reference in the crypto_alg_list to this algorithm
292	* if we try to unregister. Unregistering such an algorithm without
293	* removing the module is not possible, so we restrict to crypto
294	* instances that are build from templates. */
295	if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
296	return -EINVAL;
297
298	if (atomic_read(&alg->cra_refcnt) != 1)
299	return -EBUSY;
300
ce3fd840	301	return crypto_unregister_instance(alg);
a38f7907 SK	302	}
	303
	304	static int crypto_add_alg(struct sk_buff skb, struct nlmsghdr nlh,
	305	struct nlattr **attrs)
	306	{
0cfdec7a	307	int exact = 0;
a38f7907 SK	308	const char *name;
	309	struct crypto_alg *alg;
	310	struct crypto_user_alg *p = nlmsg_data(nlh);
	311	struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
	312
	313	if (strlen(p->cru_driver_name))
	314	exact = 1;
	315
	316	if (priority && !exact)
	317	return -EINVAL;
	318
	319	alg = crypto_alg_match(p, exact);
	320	if (alg)
	321	return -EEXIST;
	322
	323	if (strlen(p->cru_driver_name))
	324	name = p->cru_driver_name;
	325	else
	326	name = p->cru_name;
	327
	328	alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
	329	if (IS_ERR(alg))
	330	return PTR_ERR(alg);
	331
	332	down_write(&crypto_alg_sem);
	333
	334	if (priority)
	335	alg->cra_priority = nla_get_u32(priority);
	336
	337	up_write(&crypto_alg_sem);
	338
	339	crypto_mod_put(alg);
	340
	341	return 0;
	342	}
	343
	344	#define MSGSIZE(type) sizeof(struct type)
	345
	346	static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
	347	[CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	348	[CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	349	[CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	350	[CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	351	};
	352
	353	static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
	354	[CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
	355	};
	356
	357	#undef MSGSIZE
	358
	359	static struct crypto_link {
	360	int (doit)(struct sk_buff , struct nlmsghdr , struct nlattr *);
	361	int (dump)(struct sk_buff , struct netlink_callback *);
	362	int (done)(struct netlink_callback );
	363	} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
	364	[CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
	365	[CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
	366	[CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
	367	[CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
	368	.dump = crypto_dump_report,
	369	.done = crypto_dump_report_done},
	370	};
	371
372	static int crypto_user_rcv_msg(struct sk_buff skb, struct nlmsghdr nlh)
373	{
374	struct nlattr *attrs[CRYPTOCFGA_MAX+1];
375	struct crypto_link *link;
376	int type, err;
377
378	type = nlh->nlmsg_type;
379	if (type > CRYPTO_MSG_MAX)
380	return -EINVAL;
381
382	type -= CRYPTO_MSG_BASE;
383	link = &crypto_dispatch[type];
384
c49c41a4	385	if (!capable(CAP_NET_ADMIN))
a38f7907 SK	386	return -EPERM;
	387
	388	if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
	389	(nlh->nlmsg_flags & NLM_F_DUMP))) {
	390	if (link->dump == NULL)
	391	return -EINVAL;
80d326fa PNA	392	{
	393	struct netlink_dump_control c = {
	394	.dump = link->dump,
	395	.done = link->done,
	396	};
	397	return netlink_dump_start(crypto_nlsk, skb, nlh, &c);
	398	}
a38f7907 SK	399	}
	400
	401	err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX,
	402	crypto_policy);
	403	if (err < 0)
	404	return err;
	405
	406	if (link->doit == NULL)
	407	return -EINVAL;
	408
	409	return link->doit(skb, nlh, attrs);
	410	}
	411
	412	static void crypto_netlink_rcv(struct sk_buff *skb)
	413	{
	414	mutex_lock(&crypto_cfg_mutex);
	415	netlink_rcv_skb(skb, &crypto_user_rcv_msg);
	416	mutex_unlock(&crypto_cfg_mutex);
	417	}
	418
	419	static int __init crypto_user_init(void)
	420	{
	421	crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO,
	422	0, crypto_netlink_rcv,
	423	NULL, THIS_MODULE);
	424	if (!crypto_nlsk)
	425	return -ENOMEM;
	426
	427	return 0;
	428	}
	429
	430	static void __exit crypto_user_exit(void)
	431	{
	432	netlink_kernel_release(crypto_nlsk);
	433	}
	434
	435	module_init(crypto_user_init);
	436	module_exit(crypto_user_exit);
	437	MODULE_LICENSE("GPL");
	438	MODULE_AUTHOR("Steffen Klassert <[email protected]>");
	439	MODULE_DESCRIPTION("Crypto userspace configuration API");