/* $NetBSD: events.c,v 1.2 2017/01/28 21:31:44 christos Exp $ */
/*
* Copyright (c) 2005, PADL Software Pty Ltd.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of PADL Software nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY PADL SOFTWARE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL PADL SOFTWARE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "kcm_locl.h"
__RCSID("$NetBSD: events.c,v 1.2 2017/01/28 21:31:44 christos Exp $");
/* thread-safe in case we multi-thread later */
static HEIMDAL_MUTEX events_mutex = HEIMDAL_MUTEX_INITIALIZER;
static kcm_event *events_head = NULL;
static time_t last_run = 0;
static char *action_strings[] = {
"NONE", "ACQUIRE_CREDS", "RENEW_CREDS",
"DESTROY_CREDS", "DESTROY_EMPTY_CACHE" };
krb5_error_code
kcm_enqueue_event(krb5_context context,
kcm_event *event)
{
krb5_error_code ret;
if (event->action == KCM_EVENT_NONE) {
return 0;
}
HEIMDAL_MUTEX_lock(&events_mutex);
ret = kcm_enqueue_event_internal(context, event);
HEIMDAL_MUTEX_unlock(&events_mutex);
return ret;
}
static void
print_times(time_t t, char buf[64])
{
if (t)
strftime(buf, 64, "%m-%dT%H:%M", gmtime(&t));
else
strlcpy(buf, "never", 64);
}
static void
log_event(kcm_event *event, char *msg)
{
char fire_time[64], expire_time[64];
print_times(event->fire_time, fire_time);
print_times(event->expire_time, expire_time);
kcm_log(7, "%s event %08x: fire_time %s fire_count %d expire_time %s "
"backoff_time %d action %s cache %s",
msg, event, fire_time, event->fire_count, expire_time,
event->backoff_time, action_strings[event->action],
event->ccache->name);
}
krb5_error_code
kcm_enqueue_event_internal(krb5_context context,
kcm_event *event)
{
kcm_event **e;
if (event->action == KCM_EVENT_NONE)
return 0;
for (e = &events_head; *e != NULL; e = &(*e)->next)
;
*e = (kcm_event *)malloc(sizeof(kcm_event));
if (*e == NULL) {
return KRB5_CC_NOMEM;
}
(*e)->valid = 1;
(*e)->fire_time = event->fire_time;
(*e)->fire_count = 0;
(*e)->expire_time = event->expire_time;
(*e)->backoff_time = event->backoff_time;
(*e)->action = event->action;
kcm_retain_ccache(context, event->ccache);
(*e)->ccache = event->ccache;
(*e)->next = NULL;
log_event(*e, "enqueuing");
return 0;
}
/*
* Dump events list on SIGUSR2
*/
krb5_error_code
kcm_debug_events(krb5_context context)
{
kcm_event *e;
for (e = events_head; e != NULL; e = e->next)
log_event(e, "debug");
return 0;
}
krb5_error_code
kcm_enqueue_event_relative(krb5_context context,
kcm_event *event)
{
krb5_error_code ret;
kcm_event e;
e = *event;
e.backoff_time = e.fire_time;
e.fire_time += time(NULL);
ret = kcm_enqueue_event(context, &e);
return ret;
}
static krb5_error_code
kcm_remove_event_internal(krb5_context context,
kcm_event **e)
{
kcm_event *next;
next = (*e)->next;
(*e)->valid = 0;
(*e)->fire_time = 0;
(*e)->fire_count = 0;
(*e)->expire_time = 0;
(*e)->backoff_time = 0;
kcm_release_ccache(context, (*e)->ccache);
(*e)->next = NULL;
free(*e);
*e = next;
return 0;
}
static int
is_primary_credential_p(krb5_context context,
kcm_ccache ccache,
krb5_creds *newcred)
{
krb5_flags whichfields;
if (ccache->client == NULL)
return 0;
if (newcred->client == NULL ||
!krb5_principal_compare(context, ccache->client, newcred->client))
return 0;
/* XXX just checks whether it's the first credential in the cache */
if (ccache->creds == NULL)
return 0;
whichfields = KRB5_TC_MATCH_KEYTYPE | KRB5_TC_MATCH_FLAGS_EXACT |
KRB5_TC_MATCH_TIMES_EXACT | KRB5_TC_MATCH_AUTHDATA |
KRB5_TC_MATCH_2ND_TKT | KRB5_TC_MATCH_IS_SKEY;
return krb5_compare_creds(context, whichfields, newcred, &ccache->creds->cred);
}
/*
* Setup default events for a new credential
*/
static krb5_error_code
kcm_ccache_make_default_event(krb5_context context,
kcm_event *event,
krb5_creds *newcred)
{
krb5_error_code ret = 0;
kcm_ccache ccache = event->ccache;
event->fire_time = 0;
event->expire_time = 0;
event->backoff_time = KCM_EVENT_DEFAULT_BACKOFF_TIME;
if (newcred == NULL) {
/* no creds, must be acquire creds request */
if ((ccache->flags & KCM_MASK_KEY_PRESENT) == 0) {
kcm_log(0, "Cannot acquire credentials without a key");
return KRB5_FCC_INTERNAL;
}
event->fire_time = time(NULL); /* right away */
event->action = KCM_EVENT_ACQUIRE_CREDS;
} else if (is_primary_credential_p(context, ccache, newcred)) {
if (newcred->flags.b.renewable) {
event->action = KCM_EVENT_RENEW_CREDS;
ccache->flags |= KCM_FLAGS_RENEWABLE;
} else {
if (ccache->flags & KCM_MASK_KEY_PRESENT)
event->action = KCM_EVENT_ACQUIRE_CREDS;
else
event->action = KCM_EVENT_NONE;
ccache->flags &= ~(KCM_FLAGS_RENEWABLE);
}
/* requeue with some slop factor */
event->fire_time = newcred->times.endtime - KCM_EVENT_QUEUE_INTERVAL;
} else {
event->action = KCM_EVENT_NONE;
}
return ret;
}
krb5_error_code
kcm_ccache_enqueue_default(krb5_context context,
kcm_ccache ccache,
krb5_creds *newcred)
{
kcm_event event;
krb5_error_code ret;
memset(&event, 0, sizeof(event));
event.ccache = ccache;
ret = kcm_ccache_make_default_event(context, &event, newcred);
if (ret)
return ret;
ret = kcm_enqueue_event_internal(context, &event);
if (ret)
return ret;
return 0;
}
krb5_error_code
kcm_remove_event(krb5_context context,
kcm_event *event)
{
krb5_error_code ret;
kcm_event **e;
int found = 0;
log_event(event, "removing");
HEIMDAL_MUTEX_lock(&events_mutex);
for (e = &events_head; *e != NULL; e = &(*e)->next) {
if (event == *e) {
*e = event->next;
found++;
break;
}
}
if (!found) {
ret = KRB5_CC_NOTFOUND;
goto out;
}
ret = kcm_remove_event_internal(context, &event);
out:
HEIMDAL_MUTEX_unlock(&events_mutex);
return ret;
}
krb5_error_code
kcm_cleanup_events(krb5_context context,
kcm_ccache ccache)
{
kcm_event **e;
KCM_ASSERT_VALID(ccache);
HEIMDAL_MUTEX_lock(&events_mutex);
for (e = &events_head; *e != NULL; e = &(*e)->next) {
if ((*e)->valid && (*e)->ccache == ccache) {
kcm_remove_event_internal(context, e);
}
if (*e == NULL)
break;
}
HEIMDAL_MUTEX_unlock(&events_mutex);
return 0;
}
static krb5_error_code
kcm_fire_event(krb5_context context,
kcm_event **e)
{
kcm_event *event;
krb5_error_code ret;
krb5_creds *credp = NULL;
int oneshot = 1;
event = *e;
switch (event->action) {
case KCM_EVENT_ACQUIRE_CREDS:
ret = kcm_ccache_acquire(context, event->ccache, &credp);
oneshot = 0;
break;
case KCM_EVENT_RENEW_CREDS:
ret = kcm_ccache_refresh(context, event->ccache, &credp);
if (ret == KRB5KRB_AP_ERR_TKT_EXPIRED) {
ret = kcm_ccache_acquire(context, event->ccache, &credp);
}
oneshot = 0;
break;
case KCM_EVENT_DESTROY_CREDS:
ret = kcm_ccache_destroy(context, event->ccache->name);
break;
case KCM_EVENT_DESTROY_EMPTY_CACHE:
ret = kcm_ccache_destroy_if_empty(context, event->ccache);
break;
default:
ret = KRB5_FCC_INTERNAL;
break;
}
event->fire_count++;
if (ret) {
/* Reschedule failed event for another time */
event->fire_time += event->backoff_time;
if (event->backoff_time < KCM_EVENT_MAX_BACKOFF_TIME)
event->backoff_time *= 2;
/* Remove it if it would never get executed */
if (event->expire_time &&
event->fire_time > event->expire_time)
kcm_remove_event_internal(context, e);
} else {
if (!oneshot) {
char *cpn;
if (krb5_unparse_name(context, event->ccache->client,
&cpn))
cpn = NULL;
kcm_log(0, "%s credentials in cache %s for principal %s",
(event->action == KCM_EVENT_ACQUIRE_CREDS) ?
"Acquired" : "Renewed",
event->ccache->name,
(cpn != NULL) ? cpn : "<none>");
if (cpn != NULL)
free(cpn);
/* Succeeded, but possibly replaced with another event */
ret = kcm_ccache_make_default_event(context, event, credp);
if (ret || event->action == KCM_EVENT_NONE)
oneshot = 1;
else
log_event(event, "requeuing");
}
if (oneshot)
kcm_remove_event_internal(context, e);
}
return ret;
}
krb5_error_code
kcm_run_events(krb5_context context, time_t now)
{
krb5_error_code ret;
kcm_event **e;
const char *estr;
HEIMDAL_MUTEX_lock(&events_mutex);
/* Only run event queue every N seconds */
if (now < last_run + KCM_EVENT_QUEUE_INTERVAL) {
HEIMDAL_MUTEX_unlock(&events_mutex);
return 0;
}
/* go through events list, fire and expire */
for (e = &events_head; *e != NULL; e = &(*e)->next) {
if ((*e)->valid == 0)
continue;
if (now >= (*e)->fire_time) {
ret = kcm_fire_event(context, e);
if (ret) {
estr = krb5_get_error_message(context, ret);
kcm_log(1, "Could not fire event for cache %s: %s",
(*e)->ccache->name, estr);
krb5_free_error_message(context, estr);
}
} else if ((*e)->expire_time && now >= (*e)->expire_time) {
ret = kcm_remove_event_internal(context, e);
if (ret) {
estr = krb5_get_error_message(context, ret);
kcm_log(1, "Could not expire event for cache %s: %s",
(*e)->ccache->name, estr);
krb5_free_error_message(context, estr);
}
}
if (*e == NULL)
break;
}
last_run = now;
HEIMDAL_MUTEX_unlock(&events_mutex);
return 0;
}