Commit 6bfd4809 authored by Herbert Xu's avatar Herbert Xu
Browse files

[CRYPTO] api: Added spawns 



Spawns lock a specific crypto algorithm in place.  They can then be used
with crypto_spawn_tfm to allocate a tfm for that algorithm.  When the base
algorithm of a spawn is deregistered, all its spawns will be automatically
removed.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 492e2b63

crypto/algapi.c

+169 −16
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
 *

 */



#include <linux/err.h>

#include <linux/errno.h>

#include <linux/init.h>

#include <linux/kernel.h>
@@ -73,27 +74,96 @@ static int crypto_check_alg(struct crypto_alg *alg) 
	return crypto_set_driver_name(alg);

}



static int __crypto_register_alg(struct crypto_alg *alg)

static void crypto_destroy_instance(struct crypto_alg *alg)

{

	struct crypto_instance *inst = (void *)alg;

	struct crypto_template *tmpl = inst->tmpl;



	tmpl->free(inst);

	crypto_tmpl_put(tmpl);

}



static void crypto_remove_spawns(struct list_head *spawns,

				 struct list_head *list)

{

	struct crypto_spawn *spawn, *n;



	list_for_each_entry_safe(spawn, n, spawns, list) {

		struct crypto_instance *inst = spawn->inst;

		struct crypto_template *tmpl = inst->tmpl;



		list_del_init(&spawn->list);

		spawn->alg = NULL;



		if (crypto_is_dead(&inst->alg))

			continue;



		inst->alg.cra_flags |= CRYPTO_ALG_DEAD;

		if (!tmpl || !crypto_tmpl_get(tmpl))

			continue;



		crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);

		list_move(&inst->alg.cra_list, list);

		hlist_del(&inst->list);

		inst->alg.cra_destroy = crypto_destroy_instance;



		if (!list_empty(&inst->alg.cra_users)) {

			if (&n->list == spawns)

				n = list_entry(inst->alg.cra_users.next,

					       typeof(*n), list);

			__list_splice(&inst->alg.cra_users, spawns->prev);

		}

	}

}



static int __crypto_register_alg(struct crypto_alg *alg,

				 struct list_head *list)

{

	struct crypto_alg *q;

	int ret = -EEXIST;

	int ret = -EAGAIN;



	if (crypto_is_dead(alg))

		goto out;



	INIT_LIST_HEAD(&alg->cra_users);



	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))) {



		if (crypto_is_moribund(q))

			continue;



		if (crypto_is_larval(q)) {

			struct crypto_larval *larval = (void *)q;



			if (strcmp(alg->cra_name, q->cra_name) &&

			    strcmp(alg->cra_driver_name, q->cra_name))

				continue;



			if (larval->adult)

				continue;

			if ((q->cra_flags ^ alg->cra_flags) & larval->mask)

				continue;

			if (!crypto_mod_get(alg))

				continue;



			larval->adult = alg;

			complete(&larval->completion);

			continue;

		}



		if (strcmp(alg->cra_name, q->cra_name))

			continue;



		if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&

		    q->cra_priority > alg->cra_priority)

			continue;



		crypto_remove_spawns(&q->cra_users, list);

	}

	

	list_add(&alg->cra_list, &crypto_alg_list);
@@ -105,8 +175,20 @@ out: 
	return ret;

}



static void crypto_remove_final(struct list_head *list)

{

	struct crypto_alg *alg;

	struct crypto_alg *n;



	list_for_each_entry_safe(alg, n, list, cra_list) {

		list_del_init(&alg->cra_list);

		crypto_alg_put(alg);

	}

}



int crypto_register_alg(struct crypto_alg *alg)

{

	LIST_HEAD(list);

	int err;



	err = crypto_check_alg(alg);
@@ -114,23 +196,35 @@ int crypto_register_alg(struct crypto_alg *alg) 
		return err;



	down_write(&crypto_alg_sem);

	err = __crypto_register_alg(alg);

	err = __crypto_register_alg(alg, &list);

	up_write(&crypto_alg_sem);



	crypto_remove_final(&list);

	return err;

}

EXPORT_SYMBOL_GPL(crypto_register_alg);



int crypto_unregister_alg(struct crypto_alg *alg)

static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)

{

	int ret = -ENOENT;

	if (unlikely(list_empty(&alg->cra_list)))

		return -ENOENT;



	down_write(&crypto_alg_sem);

	if (likely(!list_empty(&alg->cra_list))) {

	alg->cra_flags |= CRYPTO_ALG_DEAD;



	crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);

	list_del_init(&alg->cra_list);

		ret = 0;

	crypto_remove_spawns(&alg->cra_users, list);



	return 0;

}

	crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);



int crypto_unregister_alg(struct crypto_alg *alg)

{

	int ret;

	LIST_HEAD(list);

	

	down_write(&crypto_alg_sem);

	ret = crypto_remove_alg(alg, &list);

	up_write(&crypto_alg_sem);



	if (ret)
@@ -140,6 +234,7 @@ int crypto_unregister_alg(struct crypto_alg *alg) 
	if (alg->cra_destroy)

		alg->cra_destroy(alg);



	crypto_remove_final(&list);

	return 0;

}

EXPORT_SYMBOL_GPL(crypto_unregister_alg);
@@ -170,6 +265,7 @@ void crypto_unregister_template(struct crypto_template *tmpl) 
	struct crypto_instance *inst;

	struct hlist_node *p, *n;

	struct hlist_head *list;

	LIST_HEAD(users);



	down_write(&crypto_alg_sem);
@@ -178,9 +274,8 @@ void crypto_unregister_template(struct crypto_template *tmpl) 


	list = &tmpl->instances;

	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);

		int err = crypto_remove_alg(&inst->alg, &users);

		BUG_ON(err);

	}



	crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
@@ -191,6 +286,7 @@ void crypto_unregister_template(struct crypto_template *tmpl) 
		BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);

		tmpl->free(inst);

	}

	crypto_remove_final(&users);

}

EXPORT_SYMBOL_GPL(crypto_unregister_template);
@@ -222,6 +318,7 @@ EXPORT_SYMBOL_GPL(crypto_lookup_template); 
int crypto_register_instance(struct crypto_template *tmpl,

			     struct crypto_instance *inst)

{

	LIST_HEAD(list);

	int err = -EINVAL;



	if (inst->alg.cra_destroy)
@@ -235,7 +332,7 @@ int crypto_register_instance(struct crypto_template *tmpl, 


	down_write(&crypto_alg_sem);



	err = __crypto_register_alg(&inst->alg);

	err = __crypto_register_alg(&inst->alg, &list);

	if (err)

		goto unlock;
@@ -245,11 +342,67 @@ int crypto_register_instance(struct crypto_template *tmpl, 
unlock:

	up_write(&crypto_alg_sem);



	crypto_remove_final(&list);



err:

	return err;

}

EXPORT_SYMBOL_GPL(crypto_register_instance);



int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,

		      struct crypto_instance *inst)

{

	int err = -EAGAIN;



	spawn->inst = inst;



	down_write(&crypto_alg_sem);

	if (!crypto_is_moribund(alg)) {

		list_add(&spawn->list, &alg->cra_users);

		spawn->alg = alg;

		err = 0;

	}

	up_write(&crypto_alg_sem);



	return err;

}

EXPORT_SYMBOL_GPL(crypto_init_spawn);



void crypto_drop_spawn(struct crypto_spawn *spawn)

{

	down_write(&crypto_alg_sem);

	list_del(&spawn->list);

	up_write(&crypto_alg_sem);

}

EXPORT_SYMBOL_GPL(crypto_drop_spawn);



struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn)

{

	struct crypto_alg *alg;

	struct crypto_alg *alg2;

	struct crypto_tfm *tfm;



	down_read(&crypto_alg_sem);

	alg = spawn->alg;

	alg2 = alg;

	if (alg2)

		alg2 = crypto_mod_get(alg2);

	up_read(&crypto_alg_sem);



	if (!alg2) {

		if (alg)

			crypto_shoot_alg(alg);

		return ERR_PTR(-EAGAIN);

	}



	tfm = __crypto_alloc_tfm(alg, 0);

	if (IS_ERR(tfm))

		crypto_mod_put(alg);



	return tfm;

}

EXPORT_SYMBOL_GPL(crypto_spawn_tfm);



int crypto_register_notifier(struct notifier_block *nb)

{

	return blocking_notifier_chain_register(&crypto_chain, nb);

crypto/api.c

+65 −30
Original line number Diff line number Diff line
@@ -15,11 +15,13 @@ 
 *

 */



#include <linux/err.h>

#include <linux/errno.h>

#include <linux/kernel.h>

#include <linux/kmod.h>

#include <linux/module.h>

#include <linux/param.h>

#include <linux/sched.h>

#include <linux/slab.h>

#include <linux/string.h>

#include "internal.h"
@@ -38,12 +40,6 @@ static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg) 
	return alg;

}



static inline void crypto_alg_put(struct crypto_alg *alg)

{

	if (atomic_dec_and_test(&alg->cra_refcnt) && alg->cra_destroy)

		alg->cra_destroy(alg);

}



struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)

{

	return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
@@ -65,6 +61,9 @@ struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type, u32 mask) 
	list_for_each_entry(q, &crypto_alg_list, cra_list) {

		int exact, fuzzy;



		if (crypto_is_moribund(q))

			continue;



		if ((q->cra_flags ^ type) & mask)

			continue;
@@ -111,7 +110,7 @@ static struct crypto_alg *crypto_larval_alloc(const char *name, u32 type, 


	larval = kzalloc(sizeof(*larval), GFP_KERNEL);

	if (!larval)

		return NULL;

		return ERR_PTR(-ENOMEM);



	larval->mask = mask;

	larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
@@ -153,8 +152,11 @@ static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg) 


	wait_for_completion_interruptible_timeout(&larval->completion, 60 * HZ);

	alg = larval->adult;

	if (alg && !crypto_mod_get(alg))

		alg = NULL;

	if (alg) {

		if (!crypto_mod_get(alg))

			alg = ERR_PTR(-EAGAIN);

	} else

		alg = ERR_PTR(-ENOENT);

	crypto_mod_put(&larval->alg);



	return alg;
@@ -165,9 +167,6 @@ static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, 
{

	struct crypto_alg *alg;



	if (!name)

		return NULL;



	down_read(&crypto_alg_sem);

	alg = __crypto_alg_lookup(name, type, mask);

	up_read(&crypto_alg_sem);
@@ -181,7 +180,10 @@ struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask) 
	struct crypto_alg *larval;

	int ok;



	mask &= ~CRYPTO_ALG_LARVAL;

	if (!name)

		return ERR_PTR(-ENOENT);



	mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);

	type &= mask;



	alg = try_then_request_module(crypto_alg_lookup(name, type, mask),
@@ -190,7 +192,7 @@ struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask) 
		return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;



	larval = crypto_larval_alloc(name, type, mask);

	if (!larval || !crypto_is_larval(larval))

	if (IS_ERR(larval) || !crypto_is_larval(larval))

		return larval;



	ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
@@ -203,7 +205,7 @@ struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask) 
		alg = crypto_larval_wait(larval);

	else {

		crypto_mod_put(larval);

		alg = NULL;

		alg = ERR_PTR(-ENOENT);

	}

	crypto_larval_kill(larval);

	return alg;
@@ -298,31 +300,40 @@ static unsigned int crypto_ctxsize(struct crypto_alg *alg, int flags) 
	return len + (alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1));

}



struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)

void crypto_shoot_alg(struct crypto_alg *alg)

{

	down_write(&crypto_alg_sem);

	alg->cra_flags |= CRYPTO_ALG_DYING;

	up_write(&crypto_alg_sem);

}

EXPORT_SYMBOL_GPL(crypto_shoot_alg);



struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 flags)

{

	struct crypto_tfm *tfm = NULL;

	struct crypto_alg *alg;

	unsigned int tfm_size;



	alg = crypto_alg_mod_lookup(name, 0, 0);

	if (alg == NULL)

		goto out;

	int err = -ENOMEM;



	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, flags);

	tfm = kzalloc(tfm_size, GFP_KERNEL);

	if (tfm == NULL)

		goto out_put;

		goto out;



	tfm->__crt_alg = alg;



	if (crypto_init_flags(tfm, flags))

	err = crypto_init_flags(tfm, flags);

	if (err)

		goto out_free_tfm;

		

	if (crypto_init_ops(tfm))

	err = crypto_init_ops(tfm);

	if (err)

		goto out_free_tfm;



	if (alg->cra_init && alg->cra_init(tfm))

	if (alg->cra_init && (err = alg->cra_init(tfm))) {

		if (err == -EAGAIN)

			crypto_shoot_alg(alg);

		goto cra_init_failed;

	}



	goto out;
@@ -330,12 +341,36 @@ cra_init_failed: 
	crypto_exit_ops(tfm);

out_free_tfm:

	kfree(tfm);

	tfm = NULL;

out_put:

	crypto_mod_put(alg);

	tfm = ERR_PTR(err);

out:

	return tfm;

}

EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);



struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)

{

	struct crypto_tfm *tfm = NULL;

	int err;



	do {

		struct crypto_alg *alg;



		alg = crypto_alg_mod_lookup(name, 0, 0);

		err = PTR_ERR(alg);

		if (IS_ERR(alg))

			continue;



		tfm = __crypto_alloc_tfm(alg, flags);

		err = 0;

		if (IS_ERR(tfm)) {

			crypto_mod_put(alg);

			err = PTR_ERR(tfm);

			tfm = NULL;

		}

	} while (err == -EAGAIN && !signal_pending(current));



	return tfm;

}



void crypto_free_tfm(struct crypto_tfm *tfm)

{
@@ -361,7 +396,7 @@ int crypto_alg_available(const char *name, u32 flags) 
	int ret = 0;

	struct crypto_alg *alg = crypto_alg_mod_lookup(name, 0, 0);

	

	if (alg) {

	if (!IS_ERR(alg)) {

		crypto_mod_put(alg);

		ret = 1;

	}

crypto/cryptomgr.c

+12 −7
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <linux/module.h>

#include <linux/notifier.h>

#include <linux/rtnetlink.h>

#include <linux/sched.h>

#include <linux/string.h>

#include <linux/workqueue.h>
@@ -44,21 +45,25 @@ static void cryptomgr_probe(void *data) 
	struct cryptomgr_param *param = data;

	struct crypto_template *tmpl;

	struct crypto_instance *inst;

	int err;



	tmpl = crypto_lookup_template(param->template);

	if (!tmpl)

		goto err;



	do {

		inst = tmpl->alloc(&param->alg, sizeof(param->alg));

		if (IS_ERR(inst))

		goto err;

	else if ((err = crypto_register_instance(tmpl, inst))) {

			err = PTR_ERR(inst);

		else if ((err = crypto_register_instance(tmpl, inst)))

			tmpl->free(inst);

		goto err;

	}

	} while (err == -EAGAIN && !signal_pending(current));



	crypto_tmpl_put(tmpl);



	if (err)

		goto err;



out:

	kfree(param);

	return;

crypto/internal.h

+19 −0
Original line number Diff line number Diff line
@@ -142,12 +142,21 @@ void crypto_exit_compress_ops(struct crypto_tfm *tfm); 


void crypto_larval_error(const char *name, u32 type, u32 mask);



void crypto_shoot_alg(struct crypto_alg *alg);

struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 flags);



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_alg_put(struct crypto_alg *alg)

{

	if (atomic_dec_and_test(&alg->cra_refcnt) && alg->cra_destroy)

		alg->cra_destroy(alg);

}



static inline int crypto_tmpl_get(struct crypto_template *tmpl)

{

	return try_module_get(tmpl->module);
@@ -163,6 +172,16 @@ static inline int crypto_is_larval(struct crypto_alg *alg) 
	return alg->cra_flags & CRYPTO_ALG_LARVAL;

}



static inline int crypto_is_dead(struct crypto_alg *alg)

{

	return alg->cra_flags & CRYPTO_ALG_DEAD;

}



static inline int crypto_is_moribund(struct crypto_alg *alg)

{

	return alg->cra_flags & (CRYPTO_ALG_DEAD | CRYPTO_ALG_DYING);

}



static inline int crypto_notify(unsigned long val, void *v)

{

	return blocking_notifier_call_chain(&crypto_chain, val, v);

include/crypto/algapi.h

+11 −0
Original line number Diff line number Diff line
@@ -36,10 +36,21 @@ struct crypto_template { 
	char name[CRYPTO_MAX_ALG_NAME];

};



struct crypto_spawn {

	struct list_head list;

	struct crypto_alg *alg;

	struct crypto_instance *inst;

};



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_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,

		      struct crypto_instance *inst);

void crypto_drop_spawn(struct crypto_spawn *spawn);

struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn);



static inline void *crypto_instance_ctx(struct crypto_instance *inst)

{

	return inst->__ctx;

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