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author | Steffen Klassert <steffen.klassert@secunet.com> | 2011-09-27 07:23:50 +0200 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2011-10-21 14:24:03 +0200 |
commit | a38f7907b926e4c6c7d389ad96cc38cec2e5a9e9 (patch) | |
tree | b8b5735b794a5ba98b8dd05ba0c87d3c09971a67 /crypto/crypto_user.c | |
parent | 22e5b20be72e2e166c3ba915b01a59a8eb2dc71f (diff) | |
download | linux-a38f7907b926e4c6c7d389ad96cc38cec2e5a9e9.tar.gz linux-a38f7907b926e4c6c7d389ad96cc38cec2e5a9e9.tar.xz |
crypto: Add userspace configuration API
This patch adds a basic userspace configuration API for the crypto layer.
With this it is possible to instantiate, remove and to show crypto
algorithms from userspace.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/crypto_user.c')
-rw-r--r-- | crypto/crypto_user.c | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c new file mode 100644 index 000000000000..513cfe7bc3ba --- /dev/null +++ b/crypto/crypto_user.c @@ -0,0 +1,372 @@ +/* + * 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"); |