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authorHerbert Xu <herbert@gondor.apana.org.au>2006-09-21 11:39:29 +1000
committerHerbert Xu <herbert@gondor.apana.org.au>2006-09-21 11:39:29 +1000
commit6bfd48096ff8ecabf955958b51ddfa7988eb0a14 (patch)
tree813799f00d8402348ba6817953b1c631541be66c /crypto/algapi.c
parent492e2b63eb10c28f4f0b694264d74a8755cd1be0 (diff)
downloadlinux-6bfd48096ff8ecabf955958b51ddfa7988eb0a14.tar.gz
[CRYPTO] api: Added spawns
Spawns lock a specific crypto algorithm in place. They can then be used with crypto_spawn_tfm to allocate a tfm for that algorithm. When the base algorithm of a spawn is deregistered, all its spawns will be automatically removed. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'crypto/algapi.c')
-rw-r--r--crypto/algapi.c185
1 files changed, 169 insertions, 16 deletions
diff --git a/crypto/algapi.c b/crypto/algapi.c
index acea250677c..36c4f1bdb52 100644
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -10,6 +10,7 @@
*
*/
+#include <linux/err.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -73,27 +74,96 @@ static int crypto_check_alg(struct crypto_alg *alg)
return crypto_set_driver_name(alg);
}
-static int __crypto_register_alg(struct crypto_alg *alg)
+static void crypto_destroy_instance(struct crypto_alg *alg)
+{
+ struct crypto_instance *inst = (void *)alg;
+ struct crypto_template *tmpl = inst->tmpl;
+
+ tmpl->free(inst);
+ crypto_tmpl_put(tmpl);
+}
+
+static void crypto_remove_spawns(struct list_head *spawns,
+ struct list_head *list)
+{
+ struct crypto_spawn *spawn, *n;
+
+ list_for_each_entry_safe(spawn, n, spawns, list) {
+ struct crypto_instance *inst = spawn->inst;
+ struct crypto_template *tmpl = inst->tmpl;
+
+ list_del_init(&spawn->list);
+ spawn->alg = NULL;
+
+ if (crypto_is_dead(&inst->alg))
+ continue;
+
+ inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
+ if (!tmpl || !crypto_tmpl_get(tmpl))
+ continue;
+
+ crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
+ list_move(&inst->alg.cra_list, list);
+ hlist_del(&inst->list);
+ inst->alg.cra_destroy = crypto_destroy_instance;
+
+ if (!list_empty(&inst->alg.cra_users)) {
+ if (&n->list == spawns)
+ n = list_entry(inst->alg.cra_users.next,
+ typeof(*n), list);
+ __list_splice(&inst->alg.cra_users, spawns->prev);
+ }
+ }
+}
+
+static int __crypto_register_alg(struct crypto_alg *alg,
+ struct list_head *list)
{
struct crypto_alg *q;
- int ret = -EEXIST;
+ int ret = -EAGAIN;
+
+ if (crypto_is_dead(alg))
+ goto out;
+
+ INIT_LIST_HEAD(&alg->cra_users);
+
+ ret = -EEXIST;
atomic_set(&alg->cra_refcnt, 1);
list_for_each_entry(q, &crypto_alg_list, cra_list) {
if (q == alg)
goto out;
- if (crypto_is_larval(q) &&
- (!strcmp(alg->cra_name, q->cra_name) ||
- !strcmp(alg->cra_driver_name, q->cra_name))) {
+
+ if (crypto_is_moribund(q))
+ continue;
+
+ if (crypto_is_larval(q)) {
struct crypto_larval *larval = (void *)q;
+ if (strcmp(alg->cra_name, q->cra_name) &&
+ strcmp(alg->cra_driver_name, q->cra_name))
+ continue;
+
+ if (larval->adult)
+ continue;
if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
continue;
if (!crypto_mod_get(alg))
continue;
+
larval->adult = alg;
complete(&larval->completion);
+ continue;
}
+
+ if (strcmp(alg->cra_name, q->cra_name))
+ continue;
+
+ if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
+ q->cra_priority > alg->cra_priority)
+ continue;
+
+ crypto_remove_spawns(&q->cra_users, list);
}
list_add(&alg->cra_list, &crypto_alg_list);
@@ -105,8 +175,20 @@ out:
return ret;
}
+static void crypto_remove_final(struct list_head *list)
+{
+ struct crypto_alg *alg;
+ struct crypto_alg *n;
+
+ list_for_each_entry_safe(alg, n, list, cra_list) {
+ list_del_init(&alg->cra_list);
+ crypto_alg_put(alg);
+ }
+}
+
int crypto_register_alg(struct crypto_alg *alg)
{
+ LIST_HEAD(list);
int err;
err = crypto_check_alg(alg);
@@ -114,23 +196,35 @@ int crypto_register_alg(struct crypto_alg *alg)
return err;
down_write(&crypto_alg_sem);
- err = __crypto_register_alg(alg);
+ err = __crypto_register_alg(alg, &list);
up_write(&crypto_alg_sem);
+ crypto_remove_final(&list);
return err;
}
EXPORT_SYMBOL_GPL(crypto_register_alg);
+static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
+{
+ if (unlikely(list_empty(&alg->cra_list)))
+ return -ENOENT;
+
+ alg->cra_flags |= CRYPTO_ALG_DEAD;
+
+ crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
+ list_del_init(&alg->cra_list);
+ crypto_remove_spawns(&alg->cra_users, list);
+
+ return 0;
+}
+
int crypto_unregister_alg(struct crypto_alg *alg)
{
- int ret = -ENOENT;
+ int ret;
+ LIST_HEAD(list);
down_write(&crypto_alg_sem);
- if (likely(!list_empty(&alg->cra_list))) {
- list_del_init(&alg->cra_list);
- ret = 0;
- }
- crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
+ ret = crypto_remove_alg(alg, &list);
up_write(&crypto_alg_sem);
if (ret)
@@ -140,6 +234,7 @@ int crypto_unregister_alg(struct crypto_alg *alg)
if (alg->cra_destroy)
alg->cra_destroy(alg);
+ crypto_remove_final(&list);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_unregister_alg);
@@ -170,6 +265,7 @@ void crypto_unregister_template(struct crypto_template *tmpl)
struct crypto_instance *inst;
struct hlist_node *p, *n;
struct hlist_head *list;
+ LIST_HEAD(users);
down_write(&crypto_alg_sem);
@@ -178,9 +274,8 @@ void crypto_unregister_template(struct crypto_template *tmpl)
list = &tmpl->instances;
hlist_for_each_entry(inst, p, list, list) {
- BUG_ON(list_empty(&inst->alg.cra_list));
- list_del_init(&inst->alg.cra_list);
- crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
+ int err = crypto_remove_alg(&inst->alg, &users);
+ BUG_ON(err);
}
crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
@@ -191,6 +286,7 @@ void crypto_unregister_template(struct crypto_template *tmpl)
BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
tmpl->free(inst);
}
+ crypto_remove_final(&users);
}
EXPORT_SYMBOL_GPL(crypto_unregister_template);
@@ -222,6 +318,7 @@ EXPORT_SYMBOL_GPL(crypto_lookup_template);
int crypto_register_instance(struct crypto_template *tmpl,
struct crypto_instance *inst)
{
+ LIST_HEAD(list);
int err = -EINVAL;
if (inst->alg.cra_destroy)
@@ -235,7 +332,7 @@ int crypto_register_instance(struct crypto_template *tmpl,
down_write(&crypto_alg_sem);
- err = __crypto_register_alg(&inst->alg);
+ err = __crypto_register_alg(&inst->alg, &list);
if (err)
goto unlock;
@@ -245,11 +342,67 @@ int crypto_register_instance(struct crypto_template *tmpl,
unlock:
up_write(&crypto_alg_sem);
+ crypto_remove_final(&list);
+
err:
return err;
}
EXPORT_SYMBOL_GPL(crypto_register_instance);
+int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
+ struct crypto_instance *inst)
+{
+ int err = -EAGAIN;
+
+ spawn->inst = inst;
+
+ down_write(&crypto_alg_sem);
+ if (!crypto_is_moribund(alg)) {
+ list_add(&spawn->list, &alg->cra_users);
+ spawn->alg = alg;
+ err = 0;
+ }
+ up_write(&crypto_alg_sem);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(crypto_init_spawn);
+
+void crypto_drop_spawn(struct crypto_spawn *spawn)
+{
+ down_write(&crypto_alg_sem);
+ list_del(&spawn->list);
+ up_write(&crypto_alg_sem);
+}
+EXPORT_SYMBOL_GPL(crypto_drop_spawn);
+
+struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn)
+{
+ struct crypto_alg *alg;
+ struct crypto_alg *alg2;
+ struct crypto_tfm *tfm;
+
+ down_read(&crypto_alg_sem);
+ alg = spawn->alg;
+ alg2 = alg;
+ if (alg2)
+ alg2 = crypto_mod_get(alg2);
+ up_read(&crypto_alg_sem);
+
+ if (!alg2) {
+ if (alg)
+ crypto_shoot_alg(alg);
+ return ERR_PTR(-EAGAIN);
+ }
+
+ tfm = __crypto_alloc_tfm(alg, 0);
+ if (IS_ERR(tfm))
+ crypto_mod_put(alg);
+
+ return tfm;
+}
+EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
+
int crypto_register_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&crypto_chain, nb);