freebsd-dev/sys/net/route/route_ctl.c
Alexander V. Chernikov a287a973e3 Switch rtsock code to using newly-create rib_action() KPI call.
This simplifies the code and allows to further split rtentry and nexthop,
 removing one of the blockers for multipath code introduction, described in
 D24141.

Reviewed by:	ae
Differential Revision:	https://reviews.freebsd.org/D25192
2020-06-10 07:46:22 +00:00

850 lines
19 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 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>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_mpath.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/vnet.h>
#include <net/route.h>
#include <net/route/route_ctl.h>
#include <net/route/route_var.h>
#include <net/route/nhop_utils.h>
#include <net/route/nhop.h>
#include <net/route/nhop_var.h>
#include <net/route/shared.h>
#include <netinet/in.h>
#ifdef RADIX_MPATH
#include <net/radix_mpath.h>
#endif
#include <vm/uma.h>
/*
* This file contains control plane routing tables functions.
*
* All functions assumes they are called in net epoch.
*/
struct rib_subscription {
CK_STAILQ_ENTRY(rib_subscription) next;
rib_subscription_cb_t *func;
void *arg;
enum rib_subscription_type type;
struct epoch_context epoch_ctx;
};
static void rib_notify(struct rib_head *rnh, enum rib_subscription_type type,
struct rib_cmd_info *rc);
static void rt_notifydelete(struct rtentry *rt, struct rt_addrinfo *info);
static void destroy_subscription_epoch(epoch_context_t ctx);
static struct rib_head *
get_rnh(uint32_t fibnum, const struct rt_addrinfo *info)
{
struct rib_head *rnh;
struct sockaddr *dst;
KASSERT((fibnum < rt_numfibs), ("rib_add_route: bad fibnum"));
dst = info->rti_info[RTAX_DST];
rnh = rt_tables_get_rnh(fibnum, dst->sa_family);
return (rnh);
}
/*
* Adds route defined by @info into the kernel table specified by @fibnum and
* sa_family in @info->rti_info[RTAX_DST].
*
* Returns 0 on success and fills in operation metadata into @rc.
*/
int
rib_add_route(uint32_t fibnum, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
struct rib_head *rnh;
NET_EPOCH_ASSERT();
rnh = get_rnh(fibnum, info);
if (rnh == NULL)
return (EAFNOSUPPORT);
/*
* Check consistency between RTF_HOST flag and netmask
* existence.
*/
if (info->rti_flags & RTF_HOST)
info->rti_info[RTAX_NETMASK] = NULL;
else if (info->rti_info[RTAX_NETMASK] == NULL)
return (EINVAL);
bzero(rc, sizeof(struct rib_cmd_info));
rc->rc_cmd = RTM_ADD;
return (add_route(rnh, info, rc));
}
int
add_route(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
struct sockaddr *dst, *ndst, *gateway, *netmask;
struct rtentry *rt, *rt_old;
struct nhop_object *nh;
struct radix_node *rn;
struct ifaddr *ifa;
int error, flags;
struct epoch_tracker et;
dst = info->rti_info[RTAX_DST];
gateway = info->rti_info[RTAX_GATEWAY];
netmask = info->rti_info[RTAX_NETMASK];
flags = info->rti_flags;
if ((flags & RTF_GATEWAY) && !gateway)
return (EINVAL);
if (dst && gateway && (dst->sa_family != gateway->sa_family) &&
(gateway->sa_family != AF_UNSPEC) && (gateway->sa_family != AF_LINK))
return (EINVAL);
if (dst->sa_len > sizeof(((struct rtentry *)NULL)->rt_dstb))
return (EINVAL);
if (info->rti_ifa == NULL) {
error = rt_getifa_fib(info, rnh->rib_fibnum);
if (error)
return (error);
} else {
ifa_ref(info->rti_ifa);
}
NET_EPOCH_ENTER(et);
error = nhop_create_from_info(rnh, info, &nh);
NET_EPOCH_EXIT(et);
if (error != 0) {
ifa_free(info->rti_ifa);
return (error);
}
rt = uma_zalloc(V_rtzone, M_NOWAIT);
if (rt == NULL) {
ifa_free(info->rti_ifa);
nhop_free(nh);
return (ENOBUFS);
}
rt->rt_flags = RTF_UP | flags;
rt->rt_nhop = nh;
/* Fill in dst */
memcpy(&rt->rt_dst, dst, dst->sa_len);
rt_key(rt) = &rt->rt_dst;
/*
* point to the (possibly newly malloc'd) dest address.
*/
ndst = (struct sockaddr *)rt_key(rt);
/*
* make sure it contains the value we want (masked if needed).
*/
if (netmask) {
rt_maskedcopy(dst, ndst, netmask);
} else
bcopy(dst, ndst, dst->sa_len);
/*
* We use the ifa reference returned by rt_getifa_fib().
* This moved from below so that rnh->rnh_addaddr() can
* examine the ifa and ifa->ifa_ifp if it so desires.
*/
ifa = info->rti_ifa;
rt->rt_weight = 1;
rt_setmetrics(info, rt);
rt_old = NULL;
RIB_WLOCK(rnh);
RT_LOCK(rt);
#ifdef RADIX_MPATH
/* do not permit exactly the same dst/mask/gw pair */
if (rt_mpath_capable(rnh) &&
rt_mpath_conflict(rnh, rt, netmask)) {
RIB_WUNLOCK(rnh);
nhop_free(nh);
uma_zfree(V_rtzone, rt);
return (EEXIST);
}
#endif
rn = rnh->rnh_addaddr(ndst, netmask, &rnh->head, rt->rt_nodes);
if (rn != NULL) {
/* Most common usecase */
if (rt->rt_expire > 0)
tmproutes_update(rnh, rt);
/* Finalize notification */
rnh->rnh_gen++;
rc->rc_rt = RNTORT(rn);
rc->rc_nh_new = nh;
rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc);
} else if ((info->rti_flags & RTF_PINNED) != 0) {
/*
* Force removal and re-try addition
* TODO: better multipath&pinned support
*/
struct sockaddr *info_dst = info->rti_info[RTAX_DST];
info->rti_info[RTAX_DST] = ndst;
/* Do not delete existing PINNED(interface) routes */
info->rti_flags &= ~RTF_PINNED;
rt_old = rt_unlinkrte(rnh, info, &error);
info->rti_flags |= RTF_PINNED;
info->rti_info[RTAX_DST] = info_dst;
if (rt_old != NULL) {
rn = rnh->rnh_addaddr(ndst, netmask, &rnh->head,
rt->rt_nodes);
/* Finalize notification */
rnh->rnh_gen++;
if (rn != NULL) {
rc->rc_cmd = RTM_CHANGE;
rc->rc_rt = RNTORT(rn);
rc->rc_nh_old = rt_old->rt_nhop;
rc->rc_nh_new = nh;
} else {
rc->rc_cmd = RTM_DELETE;
rc->rc_rt = RNTORT(rn);
rc->rc_nh_old = rt_old->rt_nhop;
rc->rc_nh_new = nh;
}
rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc);
}
}
RIB_WUNLOCK(rnh);
if ((rn != NULL) || (rt_old != NULL))
rib_notify(rnh, RIB_NOTIFY_DELAYED, rc);
if (rt_old != NULL) {
rt_notifydelete(rt_old, info);
rtfree(rt_old);
}
/*
* If it still failed to go into the tree,
* then un-make it (this should be a function)
*/
if (rn == NULL) {
nhop_free(nh);
uma_zfree(V_rtzone, rt);
return (EEXIST);
}
/*
* If this protocol has something to add to this then
* allow it to do that as well.
*/
if (ifa->ifa_rtrequest)
ifa->ifa_rtrequest(RTM_ADD, rt, rt->rt_nhop, info);
RT_UNLOCK(rt);
return (0);
}
/*
* Removes route defined by @info from the kernel table specified by @fibnum and
* sa_family in @info->rti_info[RTAX_DST].
*
* Returns 0 on success and fills in operation metadata into @rc.
*/
int
rib_del_route(uint32_t fibnum, struct rt_addrinfo *info, struct rib_cmd_info *rc)
{
struct rib_head *rnh;
NET_EPOCH_ASSERT();
rnh = get_rnh(fibnum, info);
if (rnh == NULL)
return (EAFNOSUPPORT);
bzero(rc, sizeof(struct rib_cmd_info));
rc->rc_cmd = RTM_DELETE;
return (del_route(rnh, info, rc));
}
/*
* Conditionally unlinks rtentry matching data inside @info from @rnh.
* Returns unlinked, locked and referenced @rtentry on success,
* Returns NULL and sets @perror to:
* ESRCH - if prefix was not found,
* EADDRINUSE - if trying to delete PINNED route without appropriate flag.
* ENOENT - if supplied filter function returned 0 (not matched).
*/
struct rtentry *
rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo *info, int *perror)
{
struct sockaddr *dst, *netmask;
struct rtentry *rt;
struct radix_node *rn;
dst = info->rti_info[RTAX_DST];
netmask = info->rti_info[RTAX_NETMASK];
rt = (struct rtentry *)rnh->rnh_lookup(dst, netmask, &rnh->head);
if (rt == NULL) {
*perror = ESRCH;
return (NULL);
}
if ((info->rti_flags & RTF_PINNED) == 0) {
/* Check if target route can be deleted */
if (rt->rt_flags & RTF_PINNED) {
*perror = EADDRINUSE;
return (NULL);
}
}
if (info->rti_filter != NULL) {
if (info->rti_filter(rt, rt->rt_nhop, info->rti_filterdata)==0){
/* Not matched */
*perror = ENOENT;
return (NULL);
}
/*
* Filter function requested rte deletion.
* Ease the caller work by filling in remaining info
* from that particular entry.
*/
info->rti_info[RTAX_GATEWAY] = &rt->rt_nhop->gw_sa;
}
/*
* Remove the item from the tree and return it.
* Complain if it is not there and do no more processing.
*/
*perror = ESRCH;
#ifdef RADIX_MPATH
if (rt_mpath_capable(rnh))
rn = rt_mpath_unlink(rnh, info, rt, perror);
else
#endif
rn = rnh->rnh_deladdr(dst, netmask, &rnh->head);
if (rn == NULL)
return (NULL);
if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT))
panic ("rtrequest delete");
rt = RNTORT(rn);
RT_LOCK(rt);
rt->rt_flags &= ~RTF_UP;
*perror = 0;
return (rt);
}
int
del_route(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
struct sockaddr *dst, *netmask;
struct sockaddr_storage mdst;
struct rtentry *rt;
int error;
dst = info->rti_info[RTAX_DST];
netmask = info->rti_info[RTAX_NETMASK];
if (netmask) {
if (dst->sa_len > sizeof(mdst))
return (EINVAL);
rt_maskedcopy(dst, (struct sockaddr *)&mdst, netmask);
dst = (struct sockaddr *)&mdst;
}
RIB_WLOCK(rnh);
rt = rt_unlinkrte(rnh, info, &error);
if (rt != NULL) {
/* Finalize notification */
rnh->rnh_gen++;
rc->rc_rt = rt;
rc->rc_nh_old = rt->rt_nhop;
rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc);
}
RIB_WUNLOCK(rnh);
if (error != 0)
return (error);
rib_notify(rnh, RIB_NOTIFY_DELAYED, rc);
rt_notifydelete(rt, info);
/*
* If the caller wants it, then it can have it,
* the entry will be deleted after the end of the current epoch.
*/
rtfree(rt);
return (0);
}
int
rib_change_route(uint32_t fibnum, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
struct rib_head *rnh;
NET_EPOCH_ASSERT();
rnh = get_rnh(fibnum, info);
if (rnh == NULL)
return (EAFNOSUPPORT);
bzero(rc, sizeof(struct rib_cmd_info));
rc->rc_cmd = RTM_CHANGE;
return (change_route(rnh, info, rc));
}
static int
change_route_one(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
RIB_RLOCK_TRACKER;
struct rtentry *rt = NULL;
int error = 0;
int free_ifa = 0;
struct nhop_object *nh, *nh_orig;
RIB_RLOCK(rnh);
rt = (struct rtentry *)rnh->rnh_lookup(info->rti_info[RTAX_DST],
info->rti_info[RTAX_NETMASK], &rnh->head);
if (rt == NULL) {
RIB_RUNLOCK(rnh);
return (ESRCH);
}
#ifdef RADIX_MPATH
/*
* If we got multipath routes,
* we require users to specify a matching RTAX_GATEWAY.
*/
if (rt_mpath_capable(rnh)) {
rt = rt_mpath_matchgate(rt, info->rti_info[RTAX_GATEWAY]);
if (rt == NULL) {
RIB_RUNLOCK(rnh);
return (ESRCH);
}
}
#endif
nh_orig = rt->rt_nhop;
RIB_RUNLOCK(rnh);
rt = NULL;
nh = NULL;
/*
* New gateway could require new ifaddr, ifp;
* flags may also be different; ifp may be specified
* by ll sockaddr when protocol address is ambiguous
*/
if (((nh_orig->nh_flags & NHF_GATEWAY) &&
info->rti_info[RTAX_GATEWAY] != NULL) ||
info->rti_info[RTAX_IFP] != NULL ||
(info->rti_info[RTAX_IFA] != NULL &&
!sa_equal(info->rti_info[RTAX_IFA], nh_orig->nh_ifa->ifa_addr))) {
error = rt_getifa_fib(info, rnh->rib_fibnum);
if (info->rti_ifa != NULL)
free_ifa = 1;
if (error != 0) {
if (free_ifa) {
ifa_free(info->rti_ifa);
info->rti_ifa = NULL;
}
return (error);
}
}
error = nhop_create_from_nhop(rnh, nh_orig, info, &nh);
if (free_ifa) {
ifa_free(info->rti_ifa);
info->rti_ifa = NULL;
}
if (error != 0)
return (error);
RIB_WLOCK(rnh);
/* Lookup rtentry once again and check if nexthop is still the same */
rt = (struct rtentry *)rnh->rnh_lookup(info->rti_info[RTAX_DST],
info->rti_info[RTAX_NETMASK], &rnh->head);
if (rt == NULL) {
RIB_WUNLOCK(rnh);
nhop_free(nh);
return (ESRCH);
}
if (rt->rt_nhop != nh_orig) {
RIB_WUNLOCK(rnh);
nhop_free(nh);
return (EAGAIN);
}
/* Proceed with the update */
RT_LOCK(rt);
/* Provide notification to the protocols.*/
if ((nh_orig->nh_ifa != nh->nh_ifa) && nh_orig->nh_ifa->ifa_rtrequest)
nh_orig->nh_ifa->ifa_rtrequest(RTM_DELETE, rt, nh_orig, info);
rt->rt_nhop = nh;
rt_setmetrics(info, rt);
if ((nh_orig->nh_ifa != nh->nh_ifa) && nh_orig->nh_ifa->ifa_rtrequest)
nh_orig->nh_ifa->ifa_rtrequest(RTM_DELETE, rt, nh_orig, info);
/* Finalize notification */
rc->rc_rt = rt;
rc->rc_nh_old = nh_orig;
rc->rc_nh_new = rt->rt_nhop;
RT_UNLOCK(rt);
/* Update generation id to reflect rtable change */
rnh->rnh_gen++;
rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc);
RIB_WUNLOCK(rnh);
rib_notify(rnh, RIB_NOTIFY_DELAYED, rc);
nhop_free(nh_orig);
return (0);
}
int
change_route(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
int error;
/* Check if updated gateway exists */
if ((info->rti_flags & RTF_GATEWAY) &&
(info->rti_info[RTAX_GATEWAY] == NULL))
return (EINVAL);
/*
* route change is done in multiple steps, with dropping and
* reacquiring lock. In the situations with multiple processes
* changes the same route in can lead to the case when route
* is changed between the steps. Address it by retrying the operation
* multiple times before failing.
*/
for (int i = 0; i < RIB_MAX_RETRIES; i++) {
error = change_route_one(rnh, info, rc);
if (error != EAGAIN)
break;
}
return (error);
}
/*
* Performs modification of routing table specificed by @action.
* Table is specified by @fibnum and sa_family in @info->rti_info[RTAX_DST].
* Needs to be run in network epoch.
*
* Returns 0 on success and fills in @rc with action result.
*/
int
rib_action(uint32_t fibnum, int action, struct rt_addrinfo *info,
struct rib_cmd_info *rc)
{
int error;
switch (action) {
case RTM_ADD:
error = rib_add_route(fibnum, info, rc);
break;
case RTM_DELETE:
error = rib_del_route(fibnum, info, rc);
break;
case RTM_CHANGE:
error = rib_change_route(fibnum, info, rc);
break;
default:
error = ENOTSUP;
}
return (error);
}
static void
rt_notifydelete(struct rtentry *rt, struct rt_addrinfo *info)
{
struct ifaddr *ifa;
/*
* give the protocol a chance to keep things in sync.
*/
ifa = rt->rt_nhop->nh_ifa;
if (ifa != NULL && ifa->ifa_rtrequest != NULL)
ifa->ifa_rtrequest(RTM_DELETE, rt, rt->rt_nhop, info);
}
struct rt_delinfo
{
struct rt_addrinfo info;
struct rib_head *rnh;
struct rtentry *head;
struct rib_cmd_info rc;
};
/*
* Conditionally unlinks @rn from radix tree based
* on info data passed in @arg.
*/
static int
rt_checkdelroute(struct radix_node *rn, void *arg)
{
struct rt_delinfo *di;
struct rt_addrinfo *info;
struct rtentry *rt;
int error;
di = (struct rt_delinfo *)arg;
rt = (struct rtentry *)rn;
info = &di->info;
error = 0;
info->rti_info[RTAX_DST] = rt_key(rt);
info->rti_info[RTAX_NETMASK] = rt_mask(rt);
info->rti_info[RTAX_GATEWAY] = &rt->rt_nhop->gw_sa;
rt = rt_unlinkrte(di->rnh, info, &error);
if (rt == NULL) {
/* Either not allowed or not matched. Skip entry */
return (0);
}
/* Entry was unlinked. Notify subscribers */
di->rnh->rnh_gen++;
di->rc.rc_rt = rt;
di->rc.rc_nh_old = rt->rt_nhop;
rib_notify(di->rnh, RIB_NOTIFY_IMMEDIATE, &di->rc);
/* Add to the list and return */
rt->rt_chain = di->head;
di->head = rt;
return (0);
}
/*
* Iterates over a routing table specified by @fibnum and @family and
* deletes elements marked by @filter_f.
* @fibnum: rtable id
* @family: AF_ address family
* @filter_f: function returning non-zero value for items to delete
* @arg: data to pass to the @filter_f function
* @report: true if rtsock notification is needed.
*/
void
rib_walk_del(u_int fibnum, int family, rt_filter_f_t *filter_f, void *arg, bool report)
{
struct rib_head *rnh;
struct rt_delinfo di;
struct rtentry *rt;
struct epoch_tracker et;
rnh = rt_tables_get_rnh(fibnum, family);
if (rnh == NULL)
return;
bzero(&di, sizeof(di));
di.info.rti_filter = filter_f;
di.info.rti_filterdata = arg;
di.rnh = rnh;
di.rc.rc_cmd = RTM_DELETE;
NET_EPOCH_ENTER(et);
RIB_WLOCK(rnh);
rnh->rnh_walktree(&rnh->head, rt_checkdelroute, &di);
RIB_WUNLOCK(rnh);
/* We might have something to reclaim. */
while (di.head != NULL) {
rt = di.head;
di.head = rt->rt_chain;
rt->rt_chain = NULL;
di.rc.rc_rt = rt;
di.rc.rc_nh_old = rt->rt_nhop;
rib_notify(rnh, RIB_NOTIFY_DELAYED, &di.rc);
/* TODO std rt -> rt_addrinfo export */
di.info.rti_info[RTAX_DST] = rt_key(rt);
di.info.rti_info[RTAX_NETMASK] = rt_mask(rt);
rt_notifydelete(rt, &di.info);
if (report)
rt_routemsg(RTM_DELETE, rt, rt->rt_nhop->nh_ifp, 0,
fibnum);
rtfree(rt);
}
NET_EPOCH_EXIT(et);
}
static 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);
}
}
/*
* Subscribe for the changes in the routing table specified by @fibnum and
* @family.
* Needs to be run in network epoch.
*
* 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, int waitok)
{
struct rib_head *rnh;
struct rib_subscription *rs;
int flags = M_ZERO | (waitok ? M_WAITOK : 0);
NET_EPOCH_ASSERT();
KASSERT((fibnum < rt_numfibs), ("%s: bad fibnum", __func__));
rnh = rt_tables_get_rnh(fibnum, family);
rs = malloc(sizeof(struct rib_subscription), M_RTABLE, flags);
if (rs == NULL)
return (NULL);
rs->func = f;
rs->arg = arg;
rs->type = type;
RIB_WLOCK(rnh);
CK_STAILQ_INSERT_TAIL(&rnh->rnh_subscribers, rs, next);
RIB_WUNLOCK(rnh);
return (rs);
}
/*
* Remove rtable subscription @rs from the table specified by @fibnum
* and @family.
* Needs to be run in network epoch.
*
* Returns 0 on success.
*/
int
rib_unsibscribe(uint32_t fibnum, int family, struct rib_subscription *rs)
{
struct rib_head *rnh;
NET_EPOCH_ASSERT();
KASSERT((fibnum < rt_numfibs), ("%s: bad fibnum", __func__));
rnh = rt_tables_get_rnh(fibnum, family);
if (rnh == NULL)
return (ENOENT);
RIB_WLOCK(rnh);
CK_STAILQ_REMOVE(&rnh->rnh_subscribers, rs, rib_subscription, next);
RIB_WUNLOCK(rnh);
epoch_call(net_epoch_preempt, destroy_subscription_epoch,
&rs->epoch_ctx);
return (0);
}
/*
* 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);
}