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

[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: 's avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
parent 492e2b63
......@@ -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 @@ static int __crypto_register_alg(struct crypto_alg *alg)
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);
static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
{
if (unlikely(list_empty(&alg->cra_list)))
return -ENOENT;
alg->cra_flags |= CRYPTO_ALG_DEAD;
crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
list_del_init(&alg->cra_list);
crypto_remove_spawns(&alg->cra_users, list);
return 0;
}
int crypto_unregister_alg(struct crypto_alg *alg)
{
int ret = -ENOENT;
int ret;
LIST_HEAD(list);
down_write(&crypto_alg_sem);
if (likely(!list_empty(&alg->cra_list))) {
list_del_init(&alg->cra_list);
ret = 0;
}
crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
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);
......
......@@ -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 @@ struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
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;
}
......
......@@ -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;
inst = tmpl->alloc(&param->alg, sizeof(param->alg));
if (IS_ERR(inst))
goto err;
else if ((err = crypto_register_instance(tmpl, inst))) {
tmpl->free(inst);
goto err;
}
do {
inst = tmpl->alloc(&param->alg, sizeof(param->alg));
if (IS_ERR(inst))
err = PTR_ERR(inst);
else if ((err = crypto_register_instance(tmpl, inst)))
tmpl->free(inst);
} while (err == -EAGAIN && !signal_pending(current));
crypto_tmpl_put(tmpl);
if (err)
goto err;
out:
kfree(param);
return;
......
......@@ -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);
......
......@@ -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;
......
......@@ -35,6 +35,8 @@
#define CRYPTO_ALG_TYPE_COMPRESS 0x00000004
#define CRYPTO_ALG_LARVAL 0x00000010
#define CRYPTO_ALG_DEAD 0x00000020
#define CRYPTO_ALG_DYING 0x00000040
/*
* Transform masks and values (for crt_flags).
......@@ -145,6 +147,8 @@ struct compress_alg {
struct crypto_alg {
struct list_head cra_list;
struct list_head cra_users;
u32 cra_flags;
unsigned int cra_blocksize;
unsigned int cra_ctxsize;
......
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