From 2825982d9d66ebba4b532a07391dfbb357f71c5f Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sun, 6 Aug 2006 21:23:26 +1000 Subject: [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 Signed-off-by: David S. Miller --- crypto/api.c | 122 +++++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 110 insertions(+), 12 deletions(-) (limited to 'crypto/api.c') diff --git a/crypto/api.c b/crypto/api.c index c922090b484..5a0d6a17cfd 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #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) -- cgit v1.2.3