[CRYPTO] api: Added spawns
[linux-2.6.git] / crypto / algapi.c
index acea250..36c4f1b 100644 (file)
@@ -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);
 
+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);