Hi: [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 <[EMAIL PROTECTED]> Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} <[EMAIL PROTECTED]> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- diff --git a/crypto/api.c b/crypto/api.c --- a/crypto/api.c +++ b/crypto/api.c @@ -22,6 +22,8 @@ #include <linux/errno.h> #include <linux/kernel.h> #include <linux/kmod.h> +#include <linux/notifier.h> +#include <linux/param.h> #include <linux/rwsem.h> #include <linux/slab.h> #include <linux/string.h> @@ -31,6 +33,8 @@ LIST_HEAD(crypto_alg_list); static LIST_HEAD(crypto_template_list); DECLARE_RWSEM(crypto_alg_sem); +static BLOCKING_NOTIFIER_HEAD(crypto_chain); + static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg) { atomic_inc(&alg->cra_refcnt); @@ -54,16 +58,21 @@ static void crypto_mod_put(struct crypto module_put(alg->cra_module); } -static struct crypto_alg *crypto_alg_lookup(const char *name) +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); +} + +static 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; @@ -83,16 +92,130 @@ static struct crypto_alg *crypto_alg_loo if (exact) break; } - + + return alg; +} + +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; +} + +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 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) @@ -280,14 +403,27 @@ static int __crypto_register_alg(struct 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; } @@ -316,6 +452,7 @@ int crypto_unregister_alg(struct crypto_ list_del_init(&alg->cra_list); ret = 0; } + crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg); up_write(&crypto_alg_sem); if (ret) @@ -341,6 +478,7 @@ int crypto_register_template(struct cryp } list_add(&tmpl->list, &crypto_template_list); + crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl); err = 0; out: up_write(&crypto_alg_sem); @@ -363,8 +501,11 @@ void crypto_unregister_template(struct c 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) { @@ -443,6 +584,18 @@ int crypto_alg_available(const char *nam return ret; } +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 init_crypto(void) { printk(KERN_INFO "Initializing Cryptographic API\n"); diff --git a/crypto/internal.h b/crypto/internal.h --- a/crypto/internal.h +++ b/crypto/internal.h @@ -12,6 +12,8 @@ */ #ifndef _CRYPTO_INTERNAL_H #define _CRYPTO_INTERNAL_H + +#include <linux/completion.h> #include <linux/crypto.h> #include <linux/mm.h> #include <linux/highmem.h> @@ -24,6 +26,17 @@ #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 notifier_block; + struct crypto_instance { struct crypto_alg alg; @@ -44,6 +57,12 @@ struct crypto_template { char name[CRYPTO_MAX_ALG_NAME]; }; +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; @@ -129,12 +148,17 @@ void crypto_exit_digest_ops(struct crypt 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_template(struct crypto_template *tmpl); void crypto_unregister_template(struct crypto_template *tmpl); struct crypto_template *crypto_lookup_template(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 void *crypto_instance_ctx(struct crypto_instance *inst) { return inst->__ctx; diff --git a/include/linux/crypto.h b/include/linux/crypto.h --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -28,11 +28,13 @@ /* * 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). */ - To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
