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/algapi.c | 50 +++++++++++++++++++- crypto/api.c | 122 ++++++++++++++++++++++++++++++++++++++++++++----- crypto/internal.h | 37 +++++++++++++++ include/linux/crypto.h | 4 +- 4 files changed, 199 insertions(+), 14 deletions(-) diff --git a/crypto/algapi.c b/crypto/algapi.c index 232b37d81613..f0df85fc1f50 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 @@ static int __crypto_register_alg(struct crypto_alg *alg) 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 @@ int crypto_unregister_alg(struct crypto_alg *alg) 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 @@ int crypto_register_template(struct crypto_template *tmpl) } 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 @@ void crypto_unregister_template(struct crypto_template *tmpl) 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 @@ err: } 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 c922090b4842..5a0d6a17cfd7 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) diff --git a/crypto/internal.h b/crypto/internal.h index c3ab4a950f30..3a08d25fba45 100644 --- a/crypto/internal.h +++ b/crypto/internal.h @@ -14,6 +14,7 @@ #define _CRYPTO_INTERNAL_H #include +#include #include #include #include @@ -21,15 +22,32 @@ #include #include #include +#include #include #include #include +/* 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 @@ static inline unsigned int crypto_compress_ctxsize(struct crypto_alg *alg, 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_digest_ops(struct crypto_tfm *tfm); 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 @@ static inline void crypto_tmpl_put(struct crypto_template *tmpl) 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 7f57ff8ec975..3e3e95aff133 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). */ -- cgit v1.2.3-59-g8ed1b