/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2021-2022 Alexander V. Chernikov
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 THE AUTHOR 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 <sys/cdefs.h>
#include "opt_route.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
#include <net/route.h>
#include <net/route/route_ctl.h>
#include <net/route/route_var.h>
#include <net/route/nhop.h>
struct rib_subscription {
CK_STAILQ_ENTRY(rib_subscription) next;
rib_subscription_cb_t *func;
void *arg;
struct rib_head *rnh;
enum rib_subscription_type type;
struct epoch_context epoch_ctx;
};
static void destroy_subscription_epoch(epoch_context_t ctx);
void
rib_notify(struct rib_head *rnh, enum rib_subscription_type type,
struct rib_cmd_info *rc)
{
struct rib_subscription *rs;
CK_STAILQ_FOREACH(rs, &rnh->rnh_subscribers, next) {
if (rs->type == type)
rs->func(rnh, rc, rs->arg);
}
}
static struct rib_subscription *
allocate_subscription(rib_subscription_cb_t *f, void *arg,
enum rib_subscription_type type, bool waitok)
{
struct rib_subscription *rs;
int flags = M_ZERO | (waitok ? M_WAITOK : M_NOWAIT);
rs = malloc(sizeof(struct rib_subscription), M_RTABLE, flags);
if (rs == NULL)
return (NULL);
rs->func = f;
rs->arg = arg;
rs->type = type;
return (rs);
}
/*
* Subscribe for the changes in the routing table specified by @fibnum and
* @family.
*
* Returns pointer to the subscription structure on success.
*/
struct rib_subscription *
rib_subscribe(uint32_t fibnum, int family, rib_subscription_cb_t *f, void *arg,
enum rib_subscription_type type, bool waitok)
{
struct rib_head *rnh;
struct epoch_tracker et;
NET_EPOCH_ENTER(et);
KASSERT((fibnum < rt_numfibs), ("%s: bad fibnum", __func__));
rnh = rt_tables_get_rnh(fibnum, family);
NET_EPOCH_EXIT(et);
return (rib_subscribe_internal(rnh, f, arg, type, waitok));
}
struct rib_subscription *
rib_subscribe_internal(struct rib_head *rnh, rib_subscription_cb_t *f, void *arg,
enum rib_subscription_type type, bool waitok)
{
struct rib_subscription *rs;
struct epoch_tracker et;
if ((rs = allocate_subscription(f, arg, type, waitok)) == NULL)
return (NULL);
rs->rnh = rnh;
NET_EPOCH_ENTER(et);
RIB_WLOCK(rnh);
CK_STAILQ_INSERT_HEAD(&rnh->rnh_subscribers, rs, next);
RIB_WUNLOCK(rnh);
NET_EPOCH_EXIT(et);
return (rs);
}
struct rib_subscription *
rib_subscribe_locked(struct rib_head *rnh, rib_subscription_cb_t *f, void *arg,
enum rib_subscription_type type)
{
struct rib_subscription *rs;
NET_EPOCH_ASSERT();
RIB_WLOCK_ASSERT(rnh);
if ((rs = allocate_subscription(f, arg, type, false)) == NULL)
return (NULL);
rs->rnh = rnh;
CK_STAILQ_INSERT_HEAD(&rnh->rnh_subscribers, rs, next);
return (rs);
}
/*
* Remove rtable subscription @rs from the routing table.
* Needs to be run in network epoch.
*/
void
rib_unsubscribe(struct rib_subscription *rs)
{
struct rib_head *rnh = rs->rnh;
NET_EPOCH_ASSERT();
RIB_WLOCK(rnh);
CK_STAILQ_REMOVE(&rnh->rnh_subscribers, rs, rib_subscription, next);
RIB_WUNLOCK(rnh);
NET_EPOCH_CALL(destroy_subscription_epoch, &rs->epoch_ctx);
}
void
rib_unsubscribe_locked(struct rib_subscription *rs)
{
struct rib_head *rnh = rs->rnh;
NET_EPOCH_ASSERT();
RIB_WLOCK_ASSERT(rnh);
CK_STAILQ_REMOVE(&rnh->rnh_subscribers, rs, rib_subscription, next);
NET_EPOCH_CALL(destroy_subscription_epoch, &rs->epoch_ctx);
}
/*
* Epoch callback indicating subscription is safe to destroy
*/
static void
destroy_subscription_epoch(epoch_context_t ctx)
{
struct rib_subscription *rs;
rs = __containerof(ctx, struct rib_subscription, epoch_ctx);
free(rs, M_RTABLE);
}
void
rib_init_subscriptions(struct rib_head *rnh)
{
CK_STAILQ_INIT(&rnh->rnh_subscribers);
}
void
rib_destroy_subscriptions(struct rib_head *rnh)
{
struct rib_subscription *rs;
struct epoch_tracker et;
NET_EPOCH_ENTER(et);
RIB_WLOCK(rnh);
while ((rs = CK_STAILQ_FIRST(&rnh->rnh_subscribers)) != NULL) {
CK_STAILQ_REMOVE_HEAD(&rnh->rnh_subscribers, next);
NET_EPOCH_CALL(destroy_subscription_epoch, &rs->epoch_ctx);
}
RIB_WUNLOCK(rnh);
NET_EPOCH_EXIT(et);
}
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