/*
* Crypto user configuration API.
*
* Copyright (C) 2011 secunet Security Networks AG
* Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com>
*
* 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)
{
int match;
struct crypto_alg *q, *alg = NULL;
down_read(&crypto_alg_sem);
if (list_empty(&crypto_alg_list))
return NULL;
list_for_each_entry(q, &crypto_alg_list, cra_list) {
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_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);
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_alg(alg);
}
static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
struct nlattr **attrs)
{
int exact;
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 (security_netlink_recv(skb, 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;
return netlink_dump_start(crypto_nlsk, skb, nlh,
link->dump, link->done, 0);
}
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 <steffen.klassert@secunet.com>");
MODULE_DESCRIPTION("Crypto userspace configuration API");
