zfs-builds-mm/zfs-0.8.5/module/icp/api/kcf_miscapi.c

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2020-10-22 13:48:46 +02:00
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#include <sys/zfs_context.h>
#include <sys/crypto/common.h>
#include <sys/crypto/api.h>
#include <sys/crypto/impl.h>
#include <sys/crypto/sched_impl.h>
/*
* All event subscribers are put on a list. kcf_notify_list_lock
* protects changes to this list.
*
* The following locking order is maintained in the code - The
* global kcf_notify_list_lock followed by the individual lock
* in a kcf_ntfy_elem structure (kn_lock).
*/
kmutex_t ntfy_list_lock;
kcondvar_t ntfy_list_cv; /* cv the service thread waits on */
static kcf_ntfy_elem_t *ntfy_list_head;
/*
* crypto_mech2id()
*
* Arguments:
* . mechname: A null-terminated string identifying the mechanism name.
*
* Description:
* Walks the mechanisms tables, looking for an entry that matches the
* mechname. Once it find it, it builds the 64-bit mech_type and returns
* it. If there are no hardware or software providers for the mechanism,
* but there is an unloaded software provider, this routine will attempt
* to load it.
*
* Context:
* Process and interruption.
*
* Returns:
* The unique mechanism identified by 'mechname', if found.
* CRYPTO_MECH_INVALID otherwise.
*/
crypto_mech_type_t
crypto_mech2id(char *mechname)
{
return (crypto_mech2id_common(mechname, B_TRUE));
}
/*
* We walk the notification list and do the callbacks.
*/
void
kcf_walk_ntfylist(uint32_t event, void *event_arg)
{
kcf_ntfy_elem_t *nep;
int nelem = 0;
mutex_enter(&ntfy_list_lock);
/*
* Count how many clients are on the notification list. We need
* this count to ensure that clients which joined the list after we
* have started this walk, are not wrongly notified.
*/
for (nep = ntfy_list_head; nep != NULL; nep = nep->kn_next)
nelem++;
for (nep = ntfy_list_head; (nep != NULL && nelem); nep = nep->kn_next) {
nelem--;
/*
* Check if this client is interested in the
* event.
*/
if (!(nep->kn_event_mask & event))
continue;
mutex_enter(&nep->kn_lock);
nep->kn_state = NTFY_RUNNING;
mutex_exit(&nep->kn_lock);
mutex_exit(&ntfy_list_lock);
/*
* We invoke the callback routine with no locks held. Another
* client could have joined the list meanwhile. This is fine
* as we maintain nelem as stated above. The NULL check in the
* for loop guards against shrinkage. Also, any callers of
* crypto_unnotify_events() at this point cv_wait till kn_state
* changes to NTFY_WAITING. Hence, nep is assured to be valid.
*/
(*nep->kn_func)(event, event_arg);
mutex_enter(&nep->kn_lock);
nep->kn_state = NTFY_WAITING;
cv_broadcast(&nep->kn_cv);
mutex_exit(&nep->kn_lock);
mutex_enter(&ntfy_list_lock);
}
mutex_exit(&ntfy_list_lock);
}
#if defined(_KERNEL)
EXPORT_SYMBOL(crypto_mech2id);
#endif