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authorHerbert Xu <herbert@gondor.apana.org.au>2006-08-06 21:23:26 +1000
committerHerbert Xu <herbert@gondor.apana.org.au>2006-09-21 11:17:13 +1000
commit2825982d9d66ebba4b532a07391dfbb357f71c5f (patch)
tree3789b26b593d081ff8eedc7e528c2b9b49a94dc2 /crypto/api.c
parent4cc7720cd165273b08a72b4193146dffee58e34b (diff)
downloadlinux-linaro-stable-2825982d9d66ebba4b532a07391dfbb357f71c5f.tar.gz
[CRYPTO] api: Added event notification
This patch adds a notifier chain for algorithm/template registration events. This will be used to register compound algorithms such as cbc(aes). In future this will also be passed onto user-space through netlink. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'crypto/api.c')
-rw-r--r--crypto/api.c122
1 files changed, 110 insertions, 12 deletions
diff --git a/crypto/api.c b/crypto/api.c
index c922090b4842..5a0d6a17cfd7 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -18,6 +18,7 @@
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/kmod.h>
+#include <linux/param.h>
#include <linux/slab.h>
#include <linux/string.h>
#include "internal.h"
@@ -27,6 +28,9 @@ EXPORT_SYMBOL_GPL(crypto_alg_list);
DECLARE_RWSEM(crypto_alg_sem);
EXPORT_SYMBOL_GPL(crypto_alg_sem);
+BLOCKING_NOTIFIER_HEAD(crypto_chain);
+EXPORT_SYMBOL_GPL(crypto_chain);
+
static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg)
{
atomic_inc(&alg->cra_refcnt);
@@ -39,27 +43,24 @@ static inline void crypto_alg_put(struct crypto_alg *alg)
alg->cra_destroy(alg);
}
-static struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
+struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
{
return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
}
+EXPORT_SYMBOL_GPL(crypto_mod_get);
-static void crypto_mod_put(struct crypto_alg *alg)
+void crypto_mod_put(struct crypto_alg *alg)
{
crypto_alg_put(alg);
module_put(alg->cra_module);
}
+EXPORT_SYMBOL_GPL(crypto_mod_put);
-static struct crypto_alg *crypto_alg_lookup(const char *name)
+struct crypto_alg *__crypto_alg_lookup(const char *name)
{
struct crypto_alg *q, *alg = NULL;
- int best = -1;
+ int best = -2;
- if (!name)
- return NULL;
-
- down_read(&crypto_alg_sem);
-
list_for_each_entry(q, &crypto_alg_list, cra_list) {
int exact, fuzzy;
@@ -79,16 +80,113 @@ static struct crypto_alg *crypto_alg_lookup(const char *name)
if (exact)
break;
}
-
+
+ return alg;
+}
+EXPORT_SYMBOL_GPL(__crypto_alg_lookup);
+
+static void crypto_larval_destroy(struct crypto_alg *alg)
+{
+ struct crypto_larval *larval = (void *)alg;
+
+ BUG_ON(!crypto_is_larval(alg));
+ if (larval->adult)
+ crypto_mod_put(larval->adult);
+ kfree(larval);
+}
+
+static struct crypto_alg *crypto_larval_alloc(const char *name)
+{
+ struct crypto_alg *alg;
+ struct crypto_larval *larval;
+
+ larval = kzalloc(sizeof(*larval), GFP_KERNEL);
+ if (!larval)
+ return NULL;
+
+ larval->alg.cra_flags = CRYPTO_ALG_LARVAL;
+ larval->alg.cra_priority = -1;
+ larval->alg.cra_destroy = crypto_larval_destroy;
+
+ atomic_set(&larval->alg.cra_refcnt, 2);
+ strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
+ init_completion(&larval->completion);
+
+ down_write(&crypto_alg_sem);
+ alg = __crypto_alg_lookup(name);
+ if (!alg) {
+ alg = &larval->alg;
+ list_add(&alg->cra_list, &crypto_alg_list);
+ }
+ up_write(&crypto_alg_sem);
+
+ if (alg != &larval->alg)
+ kfree(larval);
+
+ return alg;
+}
+
+static void crypto_larval_kill(struct crypto_alg *alg)
+{
+ struct crypto_larval *larval = (void *)alg;
+
+ down_write(&crypto_alg_sem);
+ list_del(&alg->cra_list);
+ up_write(&crypto_alg_sem);
+ complete(&larval->completion);
+ crypto_alg_put(alg);
+}
+
+static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
+{
+ struct crypto_larval *larval = (void *)alg;
+
+ wait_for_completion_interruptible_timeout(&larval->completion, 60 * HZ);
+ alg = larval->adult;
+ if (alg && !crypto_mod_get(alg))
+ alg = NULL;
+ crypto_mod_put(&larval->alg);
+
+ return alg;
+}
+
+static struct crypto_alg *crypto_alg_lookup(const char *name)
+{
+ struct crypto_alg *alg;
+
+ if (!name)
+ return NULL;
+
+ down_read(&crypto_alg_sem);
+ alg = __crypto_alg_lookup(name);
up_read(&crypto_alg_sem);
+
return alg;
}
/* A far more intelligent version of this is planned. For now, just
* try an exact match on the name of the algorithm. */
-static inline struct crypto_alg *crypto_alg_mod_lookup(const char *name)
+static struct crypto_alg *crypto_alg_mod_lookup(const char *name)
{
- return try_then_request_module(crypto_alg_lookup(name), name);
+ struct crypto_alg *alg;
+ struct crypto_alg *larval;
+
+ alg = try_then_request_module(crypto_alg_lookup(name), name);
+ if (alg)
+ return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
+
+ larval = crypto_larval_alloc(name);
+ if (!larval || !crypto_is_larval(larval))
+ return larval;
+
+ if (crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval) == NOTIFY_STOP)
+ alg = crypto_larval_wait(larval);
+ else {
+ crypto_mod_put(larval);
+ alg = NULL;
+ }
+ crypto_larval_kill(larval);
+ return alg;
}
static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags)