[linux-2.6-block.git] / crypto / crypto_user_base.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Crypto user configuration API.
 *
 * Copyright (C) 2011 secunet Security Networks AG
 * Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com>
 */

#include <linux/module.h>
#include <linux/crypto.h>
#include <linux/cryptouser.h>
#include <linux/sched.h>
#include <linux/security.h>
#include <net/netlink.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <crypto/internal/skcipher.h>
#include <crypto/internal/rng.h>
#include <crypto/akcipher.h>
#include <crypto/kpp.h>
#include <crypto/internal/cryptouser.h>

#include "internal.h"

#define null_terminated(x)	(strnlen(x, sizeof(x)) < sizeof(x))

static DEFINE_MUTEX(crypto_cfg_mutex);

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

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 (crypto_is_larval(q))
			continue;

		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)
			continue;

		if (unlikely(!crypto_mod_get(q)))
			continue;

		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;

	memset(&rcipher, 0, sizeof(rcipher));

	strscpy(rcipher.type, "cipher", sizeof(rcipher.type));

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

	return nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
		       sizeof(rcipher), &rcipher);
}

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

	memset(&rcomp, 0, sizeof(rcomp));

	strscpy(rcomp.type, "compression", sizeof(rcomp.type));

	return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(rcomp), &rcomp);
}

static int crypto_report_one(struct crypto_alg *alg,
			     struct crypto_user_alg *ualg, struct sk_buff *skb)
{
	memset(ualg, 0, sizeof(*ualg));

	strscpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
	strscpy(ualg->cru_driver_name, alg->cra_driver_name,
		sizeof(ualg->cru_driver_name));
	strscpy(ualg->cru_module_name, module_name(alg->cra_module),
		sizeof(ualg->cru_module_name));

	ualg->cru_type = 0;
	ualg->cru_mask = 0;
	ualg->cru_flags = alg->cra_flags;
	ualg->cru_refcnt = refcount_read(&alg->cra_refcnt);

	if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
		goto nla_put_failure;
	if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
		struct crypto_report_larval rl;

		memset(&rl, 0, sizeof(rl));
		strscpy(rl.type, "larval", sizeof(rl.type));
		if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(rl), &rl))
			goto nla_put_failure;
		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).portid, 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 net *net = sock_net(in_skb->sk);
	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 (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
		return -EINVAL;

	alg = crypto_alg_match(p, 0);
	if (!alg)
		return -ENOENT;

	err = -ENOMEM;
	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	if (!skb)
		goto drop_alg;

	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);

drop_alg:
	crypto_mod_put(alg);

	if (err)
		return err;

	return nlmsg_unicast(net->crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
}

static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
{
	const size_t start_pos = cb->args[0];
	size_t pos = 0;
	struct crypto_dump_info info;
	struct crypto_alg *alg;
	int res;

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

	down_read(&crypto_alg_sem);
	list_for_each_entry(alg, &crypto_alg_list, cra_list) {
		if (pos >= start_pos) {
			res = crypto_report_alg(alg, &info);
			if (res == -EMSGSIZE)
				break;
			if (res)
				goto out;
		}
		pos++;
	}
	cb->args[0] = pos;
	res = skb->len;
out:
	up_read(&crypto_alg_sem);
	return res;
}

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 (!netlink_capable(skb, CAP_NET_ADMIN))
		return -EPERM;

	if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
		return -EINVAL;

	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_mod_put(alg);
	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);
	int err;

	if (!netlink_capable(skb, CAP_NET_ADMIN))
		return -EPERM;

	if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
		return -EINVAL;

	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. */
	err = -EINVAL;
	if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
		goto drop_alg;

	err = -EBUSY;
	if (refcount_read(&alg->cra_refcnt) > 2)
		goto drop_alg;

	err = crypto_unregister_instance((struct crypto_instance *)alg);

drop_alg:
	crypto_mod_put(alg);
	return err;
}

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 (!netlink_capable(skb, CAP_NET_ADMIN))
		return -EPERM;

	if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
		return -EINVAL;

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

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

	alg = crypto_alg_match(p, exact);
	if (alg) {
		crypto_mod_put(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;
}

static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
			  struct nlattr **attrs)
{
	if (!netlink_capable(skb, CAP_NET_ADMIN))
		return -EPERM;
	return crypto_del_default_rng();
}

#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),
	[CRYPTO_MSG_DELRNG	- CRYPTO_MSG_BASE] = 0,
	[CRYPTO_MSG_GETSTAT	- 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 const 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},
	[CRYPTO_MSG_DELRNG	- CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
	[CRYPTO_MSG_GETSTAT	- CRYPTO_MSG_BASE] = { .doit = crypto_reportstat},
};

static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
			       struct netlink_ext_ack *extack)
{
	struct net *net = sock_net(skb->sk);
	struct nlattr *attrs[CRYPTOCFGA_MAX+1];
	const 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 ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
	    (nlh->nlmsg_flags & NLM_F_DUMP))) {
		struct crypto_alg *alg;
		unsigned long dump_alloc = 0;

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

		down_read(&crypto_alg_sem);
		list_for_each_entry(alg, &crypto_alg_list, cra_list)
			dump_alloc += CRYPTO_REPORT_MAXSIZE;
		up_read(&crypto_alg_sem);

		{
			struct netlink_dump_control c = {
				.dump = link->dump,
				.done = link->done,
				.min_dump_alloc = min(dump_alloc, 65535UL),
			};
			err = netlink_dump_start(net->crypto_nlsk, skb, nlh, &c);
		}

		return err;
	}

	err = nlmsg_parse_deprecated(nlh, crypto_msg_min[type], attrs,
				     CRYPTOCFGA_MAX, crypto_policy, extack);
	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 __net_init crypto_netlink_init(struct net *net)
{
	struct netlink_kernel_cfg cfg = {
		.input	= crypto_netlink_rcv,
	};

	net->crypto_nlsk = netlink_kernel_create(net, NETLINK_CRYPTO, &cfg);
	return net->crypto_nlsk == NULL ? -ENOMEM : 0;
}

static void __net_exit crypto_netlink_exit(struct net *net)
{
	netlink_kernel_release(net->crypto_nlsk);
	net->crypto_nlsk = NULL;
}

static struct pernet_operations crypto_netlink_net_ops = {
	.init = crypto_netlink_init,
	.exit = crypto_netlink_exit,
};

static int __init crypto_user_init(void)
{
	return register_pernet_subsys(&crypto_netlink_net_ops);
}

static void __exit crypto_user_exit(void)
{
	unregister_pernet_subsys(&crypto_netlink_net_ops);
}

module_init(crypto_user_init);
module_exit(crypto_user_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
MODULE_DESCRIPTION("Crypto userspace configuration API");
MODULE_ALIAS("net-pf-16-proto-21");
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* Crypto user configuration API.
	4	*
	5	* Copyright (C) 2011 secunet Security Networks AG
	6	* Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com>
	7	*/
	8
	9	#include <linux/module.h>
	10	#include <linux/crypto.h>
	11	#include <linux/cryptouser.h>
	12	#include <linux/sched.h>
	13	#include <linux/security.h>
	14	#include <net/netlink.h>
	15	#include <net/net_namespace.h>
	16	#include <net/sock.h>
	17	#include <crypto/internal/skcipher.h>
	18	#include <crypto/internal/rng.h>
	19	#include <crypto/akcipher.h>
	20	#include <crypto/kpp.h>
	21	#include <crypto/internal/cryptouser.h>
	22
	23	#include "internal.h"
	24
	25	#define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x))
	26
	27	static DEFINE_MUTEX(crypto_cfg_mutex);
	28
	29	struct crypto_dump_info {
	30	struct sk_buff *in_skb;
	31	struct sk_buff *out_skb;
	32	u32 nlmsg_seq;
	33	u16 nlmsg_flags;
	34	};
	35
	36	struct crypto_alg crypto_alg_match(struct crypto_user_alg p, int exact)
	37	{
	38	struct crypto_alg q, alg = NULL;
	39
	40	down_read(&crypto_alg_sem);
	41
	42	list_for_each_entry(q, &crypto_alg_list, cra_list) {
	43	int match = 0;
	44
	45	if (crypto_is_larval(q))
	46	continue;
	47
	48	if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
	49	continue;
	50
	51	if (strlen(p->cru_driver_name))
	52	match = !strcmp(q->cra_driver_name,
	53	p->cru_driver_name);
	54	else if (!exact)
	55	match = !strcmp(q->cra_name, p->cru_name);
	56
	57	if (!match)
	58	continue;
	59
	60	if (unlikely(!crypto_mod_get(q)))
	61	continue;
	62
	63	alg = q;
	64	break;
	65	}
	66
	67	up_read(&crypto_alg_sem);
	68
	69	return alg;
	70	}
	71
	72	static int crypto_report_cipher(struct sk_buff skb, struct crypto_alg alg)
	73	{
	74	struct crypto_report_cipher rcipher;
	75
	76	memset(&rcipher, 0, sizeof(rcipher));
	77
	78	strscpy(rcipher.type, "cipher", sizeof(rcipher.type));
	79
	80	rcipher.blocksize = alg->cra_blocksize;
	81	rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
	82	rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
	83
	84	return nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
	85	sizeof(rcipher), &rcipher);
	86	}
	87
	88	static int crypto_report_comp(struct sk_buff skb, struct crypto_alg alg)
	89	{
	90	struct crypto_report_comp rcomp;
	91
	92	memset(&rcomp, 0, sizeof(rcomp));
	93
	94	strscpy(rcomp.type, "compression", sizeof(rcomp.type));
	95
	96	return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(rcomp), &rcomp);
	97	}
	98
	99	static int crypto_report_one(struct crypto_alg *alg,
	100	struct crypto_user_alg ualg, struct sk_buff skb)
	101	{
	102	memset(ualg, 0, sizeof(*ualg));
	103
	104	strscpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
	105	strscpy(ualg->cru_driver_name, alg->cra_driver_name,
	106	sizeof(ualg->cru_driver_name));
	107	strscpy(ualg->cru_module_name, module_name(alg->cra_module),
	108	sizeof(ualg->cru_module_name));
	109
	110	ualg->cru_type = 0;
	111	ualg->cru_mask = 0;
	112	ualg->cru_flags = alg->cra_flags;
	113	ualg->cru_refcnt = refcount_read(&alg->cra_refcnt);
	114
	115	if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
	116	goto nla_put_failure;
	117	if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
	118	struct crypto_report_larval rl;
	119
	120	memset(&rl, 0, sizeof(rl));
	121	strscpy(rl.type, "larval", sizeof(rl.type));
	122	if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(rl), &rl))
	123	goto nla_put_failure;
	124	goto out;
	125	}
	126
	127	if (alg->cra_type && alg->cra_type->report) {
	128	if (alg->cra_type->report(skb, alg))
	129	goto nla_put_failure;
	130
	131	goto out;
	132	}
	133
	134	switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK \| CRYPTO_ALG_LARVAL)) {
	135	case CRYPTO_ALG_TYPE_CIPHER:
	136	if (crypto_report_cipher(skb, alg))
	137	goto nla_put_failure;
	138
	139	break;
	140	case CRYPTO_ALG_TYPE_COMPRESS:
	141	if (crypto_report_comp(skb, alg))
	142	goto nla_put_failure;
	143
	144	break;
	145	}
	146
	147	out:
	148	return 0;
	149
	150	nla_put_failure:
	151	return -EMSGSIZE;
	152	}
	153
	154	static int crypto_report_alg(struct crypto_alg *alg,
	155	struct crypto_dump_info *info)
	156	{
	157	struct sk_buff *in_skb = info->in_skb;
	158	struct sk_buff *skb = info->out_skb;
	159	struct nlmsghdr *nlh;
	160	struct crypto_user_alg *ualg;
	161	int err = 0;
	162
	163	nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
	164	CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
	165	if (!nlh) {
	166	err = -EMSGSIZE;
	167	goto out;
	168	}
	169
	170	ualg = nlmsg_data(nlh);
	171
	172	err = crypto_report_one(alg, ualg, skb);
	173	if (err) {
	174	nlmsg_cancel(skb, nlh);
	175	goto out;
	176	}
	177
	178	nlmsg_end(skb, nlh);
	179
	180	out:
	181	return err;
	182	}
	183
	184	static int crypto_report(struct sk_buff in_skb, struct nlmsghdr in_nlh,
	185	struct nlattr **attrs)
	186	{
	187	struct net *net = sock_net(in_skb->sk);
	188	struct crypto_user_alg *p = nlmsg_data(in_nlh);
	189	struct crypto_alg *alg;
	190	struct sk_buff *skb;
	191	struct crypto_dump_info info;
	192	int err;
	193
	194	if (!null_terminated(p->cru_name) \|\| !null_terminated(p->cru_driver_name))
	195	return -EINVAL;
	196
	197	alg = crypto_alg_match(p, 0);
	198	if (!alg)
	199	return -ENOENT;
	200
	201	err = -ENOMEM;
	202	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	203	if (!skb)
	204	goto drop_alg;
	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
	213	drop_alg:
	214	crypto_mod_put(alg);
	215
	216	if (err)
	217	return err;
	218
	219	return nlmsg_unicast(net->crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
	220	}
	221
	222	static int crypto_dump_report(struct sk_buff skb, struct netlink_callback cb)
	223	{
	224	const size_t start_pos = cb->args[0];
	225	size_t pos = 0;
	226	struct crypto_dump_info info;
	227	struct crypto_alg *alg;
	228	int res;
	229
	230	info.in_skb = cb->skb;
	231	info.out_skb = skb;
	232	info.nlmsg_seq = cb->nlh->nlmsg_seq;
	233	info.nlmsg_flags = NLM_F_MULTI;
	234
	235	down_read(&crypto_alg_sem);
	236	list_for_each_entry(alg, &crypto_alg_list, cra_list) {
	237	if (pos >= start_pos) {
	238	res = crypto_report_alg(alg, &info);
	239	if (res == -EMSGSIZE)
	240	break;
	241	if (res)
	242	goto out;
	243	}
	244	pos++;
	245	}
	246	cb->args[0] = pos;
	247	res = skb->len;
	248	out:
	249	up_read(&crypto_alg_sem);
	250	return res;
	251	}
	252
	253	static int crypto_dump_report_done(struct netlink_callback *cb)
	254	{
	255	return 0;
	256	}
	257
	258	static int crypto_update_alg(struct sk_buff skb, struct nlmsghdr nlh,
	259	struct nlattr **attrs)
	260	{
	261	struct crypto_alg *alg;
	262	struct crypto_user_alg *p = nlmsg_data(nlh);
	263	struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
	264	LIST_HEAD(list);
	265
	266	if (!netlink_capable(skb, CAP_NET_ADMIN))
	267	return -EPERM;
	268
	269	if (!null_terminated(p->cru_name) \|\| !null_terminated(p->cru_driver_name))
	270	return -EINVAL;
	271
	272	if (priority && !strlen(p->cru_driver_name))
	273	return -EINVAL;
	274
	275	alg = crypto_alg_match(p, 1);
	276	if (!alg)
	277	return -ENOENT;
	278
	279	down_write(&crypto_alg_sem);
	280
	281	crypto_remove_spawns(alg, &list, NULL);
	282
	283	if (priority)
	284	alg->cra_priority = nla_get_u32(priority);
	285
	286	up_write(&crypto_alg_sem);
	287
	288	crypto_mod_put(alg);
	289	crypto_remove_final(&list);
	290
	291	return 0;
	292	}
	293
	294	static int crypto_del_alg(struct sk_buff skb, struct nlmsghdr nlh,
	295	struct nlattr **attrs)
	296	{
	297	struct crypto_alg *alg;
	298	struct crypto_user_alg *p = nlmsg_data(nlh);
	299	int err;
	300
	301	if (!netlink_capable(skb, CAP_NET_ADMIN))
	302	return -EPERM;
	303
	304	if (!null_terminated(p->cru_name) \|\| !null_terminated(p->cru_driver_name))
	305	return -EINVAL;
	306
	307	alg = crypto_alg_match(p, 1);
	308	if (!alg)
	309	return -ENOENT;
	310
	311	/* We can not unregister core algorithms such as aes-generic.
	312	* We would loose the reference in the crypto_alg_list to this algorithm
	313	* if we try to unregister. Unregistering such an algorithm without
	314	* removing the module is not possible, so we restrict to crypto
	315	* instances that are build from templates. */
	316	err = -EINVAL;
	317	if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
	318	goto drop_alg;
	319
	320	err = -EBUSY;
	321	if (refcount_read(&alg->cra_refcnt) > 2)
	322	goto drop_alg;
	323
	324	err = crypto_unregister_instance((struct crypto_instance *)alg);
	325
	326	drop_alg:
	327	crypto_mod_put(alg);
	328	return err;
	329	}
	330
	331	static int crypto_add_alg(struct sk_buff skb, struct nlmsghdr nlh,
	332	struct nlattr **attrs)
	333	{
	334	int exact = 0;
	335	const char *name;
	336	struct crypto_alg *alg;
	337	struct crypto_user_alg *p = nlmsg_data(nlh);
	338	struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
	339
	340	if (!netlink_capable(skb, CAP_NET_ADMIN))
	341	return -EPERM;
	342
	343	if (!null_terminated(p->cru_name) \|\| !null_terminated(p->cru_driver_name))
	344	return -EINVAL;
	345
	346	if (strlen(p->cru_driver_name))
	347	exact = 1;
	348
	349	if (priority && !exact)
	350	return -EINVAL;
	351
	352	alg = crypto_alg_match(p, exact);
	353	if (alg) {
	354	crypto_mod_put(alg);
	355	return -EEXIST;
	356	}
	357
	358	if (strlen(p->cru_driver_name))
	359	name = p->cru_driver_name;
	360	else
	361	name = p->cru_name;
	362
	363	alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
	364	if (IS_ERR(alg))
	365	return PTR_ERR(alg);
	366
	367	down_write(&crypto_alg_sem);
	368
	369	if (priority)
	370	alg->cra_priority = nla_get_u32(priority);
	371
	372	up_write(&crypto_alg_sem);
	373
	374	crypto_mod_put(alg);
	375
	376	return 0;
	377	}
	378
	379	static int crypto_del_rng(struct sk_buff skb, struct nlmsghdr nlh,
	380	struct nlattr **attrs)
	381	{
	382	if (!netlink_capable(skb, CAP_NET_ADMIN))
	383	return -EPERM;
	384	return crypto_del_default_rng();
	385	}
	386
	387	#define MSGSIZE(type) sizeof(struct type)
	388
	389	static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
	390	[CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	391	[CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	392	[CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	393	[CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	394	[CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
	395	[CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
	396	};
	397
	398	static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
	399	[CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
	400	};
	401
	402	#undef MSGSIZE
	403
	404	static const struct crypto_link {
	405	int (doit)(struct sk_buff , struct nlmsghdr , struct nlattr *);
	406	int (dump)(struct sk_buff , struct netlink_callback *);
	407	int (done)(struct netlink_callback );
	408	} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
	409	[CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
	410	[CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
	411	[CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
	412	[CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
	413	.dump = crypto_dump_report,
	414	.done = crypto_dump_report_done},
	415	[CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
	416	[CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = { .doit = crypto_reportstat},
	417	};
	418
	419	static int crypto_user_rcv_msg(struct sk_buff skb, struct nlmsghdr nlh,
	420	struct netlink_ext_ack *extack)
	421	{
	422	struct net *net = sock_net(skb->sk);
	423	struct nlattr *attrs[CRYPTOCFGA_MAX+1];
	424	const struct crypto_link *link;
	425	int type, err;
	426
	427	type = nlh->nlmsg_type;
	428	if (type > CRYPTO_MSG_MAX)
	429	return -EINVAL;
	430
	431	type -= CRYPTO_MSG_BASE;
	432	link = &crypto_dispatch[type];
	433
	434	if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
	435	(nlh->nlmsg_flags & NLM_F_DUMP))) {
	436	struct crypto_alg *alg;
	437	unsigned long dump_alloc = 0;
	438
	439	if (link->dump == NULL)
	440	return -EINVAL;
	441
	442	down_read(&crypto_alg_sem);
	443	list_for_each_entry(alg, &crypto_alg_list, cra_list)
	444	dump_alloc += CRYPTO_REPORT_MAXSIZE;
	445	up_read(&crypto_alg_sem);
	446
	447	{
	448	struct netlink_dump_control c = {
	449	.dump = link->dump,
	450	.done = link->done,
	451	.min_dump_alloc = min(dump_alloc, 65535UL),
	452	};
	453	err = netlink_dump_start(net->crypto_nlsk, skb, nlh, &c);
	454	}
	455
	456	return err;
	457	}
	458
	459	err = nlmsg_parse_deprecated(nlh, crypto_msg_min[type], attrs,
	460	CRYPTOCFGA_MAX, crypto_policy, extack);
	461	if (err < 0)
	462	return err;
	463
	464	if (link->doit == NULL)
	465	return -EINVAL;
	466
	467	return link->doit(skb, nlh, attrs);
	468	}
	469
	470	static void crypto_netlink_rcv(struct sk_buff *skb)
	471	{
	472	mutex_lock(&crypto_cfg_mutex);
	473	netlink_rcv_skb(skb, &crypto_user_rcv_msg);
	474	mutex_unlock(&crypto_cfg_mutex);
	475	}
	476
	477	static int __net_init crypto_netlink_init(struct net *net)
	478	{
	479	struct netlink_kernel_cfg cfg = {
	480	.input = crypto_netlink_rcv,
	481	};
	482
	483	net->crypto_nlsk = netlink_kernel_create(net, NETLINK_CRYPTO, &cfg);
	484	return net->crypto_nlsk == NULL ? -ENOMEM : 0;
	485	}
	486
	487	static void __net_exit crypto_netlink_exit(struct net *net)
	488	{
	489	netlink_kernel_release(net->crypto_nlsk);
	490	net->crypto_nlsk = NULL;
	491	}
	492
	493	static struct pernet_operations crypto_netlink_net_ops = {
	494	.init = crypto_netlink_init,
	495	.exit = crypto_netlink_exit,
	496	};
	497
	498	static int __init crypto_user_init(void)
	499	{
	500	return register_pernet_subsys(&crypto_netlink_net_ops);
	501	}
	502
	503	static void __exit crypto_user_exit(void)
	504	{
	505	unregister_pernet_subsys(&crypto_netlink_net_ops);
	506	}
	507
	508	module_init(crypto_user_init);
	509	module_exit(crypto_user_exit);
	510	MODULE_LICENSE("GPL");
	511	MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
	512	MODULE_DESCRIPTION("Crypto userspace configuration API");
	513	MODULE_ALIAS("net-pf-16-proto-21");