[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>
diff --git a/crypto/algapi.c b/crypto/algapi.c
index 232b37d..f0df85f 100644
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -21,6 +21,24 @@
static LIST_HEAD(crypto_template_list);
+void crypto_larval_error(const char *name)
+{
+ struct crypto_alg *alg;
+
+ down_read(&crypto_alg_sem);
+ alg = __crypto_alg_lookup(name);
+ up_read(&crypto_alg_sem);
+
+ if (alg) {
+ if (crypto_is_larval(alg)) {
+ struct crypto_larval *larval = (void *)alg;
+ complete(&larval->completion);
+ }
+ crypto_mod_put(alg);
+ }
+}
+EXPORT_SYMBOL_GPL(crypto_larval_error);
+
static inline int crypto_set_driver_name(struct crypto_alg *alg)
{
static const char suffix[] = "-generic";
@@ -60,14 +78,27 @@
struct crypto_alg *q;
int 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))) {
+ struct crypto_larval *larval = (void *)q;
+
+ if (!crypto_mod_get(alg))
+ continue;
+ larval->adult = alg;
+ complete(&larval->completion);
+ }
}
list_add(&alg->cra_list, &crypto_alg_list);
- atomic_set(&alg->cra_refcnt, 1);
+
+ crypto_notify(CRYPTO_MSG_ALG_REGISTER, alg);
ret = 0;
+
out:
return ret;
}
@@ -97,6 +128,7 @@
list_del_init(&alg->cra_list);
ret = 0;
}
+ crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
up_write(&crypto_alg_sem);
if (ret)
@@ -123,6 +155,7 @@
}
list_add(&tmpl->list, &crypto_template_list);
+ crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
err = 0;
out:
up_write(&crypto_alg_sem);
@@ -145,8 +178,11 @@
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);
}
+ crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
+
up_write(&crypto_alg_sem);
hlist_for_each_entry_safe(inst, p, n, list, list) {
@@ -212,6 +248,18 @@
}
EXPORT_SYMBOL_GPL(crypto_register_instance);
+int crypto_register_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&crypto_chain, nb);
+}
+EXPORT_SYMBOL_GPL(crypto_register_notifier);
+
+int crypto_unregister_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&crypto_chain, nb);
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
+
static int __init crypto_algapi_init(void)
{
crypto_init_proc();
diff --git a/crypto/api.c b/crypto/api.c
index c922090..5a0d6a1 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 @@
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 @@
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 @@
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)
diff --git a/crypto/internal.h b/crypto/internal.h
index c3ab4a9..3a08d25 100644
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -14,6 +14,7 @@
#define _CRYPTO_INTERNAL_H
#include <crypto/algapi.h>
+#include <linux/completion.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/interrupt.h>
@@ -21,15 +22,32 @@
#include <linux/list.h>
#include <linux/module.h>
#include <linux/kernel.h>
+#include <linux/notifier.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <asm/kmap_types.h>
+/* Crypto notification events. */
+enum {
+ CRYPTO_MSG_ALG_REQUEST,
+ CRYPTO_MSG_ALG_REGISTER,
+ CRYPTO_MSG_ALG_UNREGISTER,
+ CRYPTO_MSG_TMPL_REGISTER,
+ CRYPTO_MSG_TMPL_UNREGISTER,
+};
+
struct crypto_instance;
struct crypto_template;
+struct crypto_larval {
+ struct crypto_alg alg;
+ struct crypto_alg *adult;
+ struct completion completion;
+};
+
extern struct list_head crypto_alg_list;
extern struct rw_semaphore crypto_alg_sem;
+extern struct blocking_notifier_head crypto_chain;
extern enum km_type crypto_km_types[];
@@ -104,6 +122,10 @@
return alg->cra_ctxsize;
}
+struct crypto_alg *crypto_mod_get(struct crypto_alg *alg);
+void crypto_mod_put(struct crypto_alg *alg);
+struct crypto_alg *__crypto_alg_lookup(const char *name);
+
int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags);
int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags);
int crypto_init_compress_flags(struct crypto_tfm *tfm, u32 flags);
@@ -116,9 +138,14 @@
void crypto_exit_cipher_ops(struct crypto_tfm *tfm);
void crypto_exit_compress_ops(struct crypto_tfm *tfm);
+void crypto_larval_error(const char *name);
+
int crypto_register_instance(struct crypto_template *tmpl,
struct crypto_instance *inst);
+int crypto_register_notifier(struct notifier_block *nb);
+int crypto_unregister_notifier(struct notifier_block *nb);
+
static inline int crypto_tmpl_get(struct crypto_template *tmpl)
{
return try_module_get(tmpl->module);
@@ -129,5 +156,15 @@
module_put(tmpl->module);
}
+static inline int crypto_is_larval(struct crypto_alg *alg)
+{
+ return alg->cra_flags & CRYPTO_ALG_LARVAL;
+}
+
+static inline int crypto_notify(unsigned long val, void *v)
+{
+ return blocking_notifier_call_chain(&crypto_chain, val, v);
+}
+
#endif /* _CRYPTO_INTERNAL_H */
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 7f57ff8..3e3e95a 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -29,11 +29,13 @@
/*
* Algorithm masks and types.
*/
-#define CRYPTO_ALG_TYPE_MASK 0x000000ff
+#define CRYPTO_ALG_TYPE_MASK 0x0000000f
#define CRYPTO_ALG_TYPE_CIPHER 0x00000001
#define CRYPTO_ALG_TYPE_DIGEST 0x00000002
#define CRYPTO_ALG_TYPE_COMPRESS 0x00000004
+#define CRYPTO_ALG_LARVAL 0x00000010
+
/*
* Transform masks and values (for crt_flags).
*/