+// SPDX-License-Identifier: GPL-2.0-or-later
/**
* bfd.c: BFD handling routines
*
* @copyright Copyright (C) 2015 Cumulus Networks, Inc.
- *
- * This file is part of GNU Zebra.
- *
- * GNU Zebra is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2, or (at your option) any
- * later version.
- *
- * GNU Zebra is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; see the file COPYING; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <zebra.h>
#include "command.h"
#include "memory.h"
#include "prefix.h"
-#include "thread.h"
+#include "frrevent.h"
#include "stream.h"
#include "vrf.h"
#include "zclient.h"
+#include "libfrr.h"
#include "table.h"
#include "vty.h"
#include "bfd.h"
DEFINE_MTYPE_STATIC(LIB, BFD_INFO, "BFD info");
+DEFINE_MTYPE_STATIC(LIB, BFD_SOURCE, "BFD source cache");
/**
* BFD protocol integration configuration.
BSE_INSTALL,
};
+/**
+ * BFD source selection result cache.
+ *
+ * This structure will keep track of the result based on the destination
+ * prefix. When the result changes all related BFD sessions with automatic
+ * source will be updated.
+ */
+struct bfd_source_cache {
+ /** Address VRF belongs. */
+ vrf_id_t vrf_id;
+ /** Destination network address. */
+ struct prefix address;
+ /** Source selected. */
+ struct prefix source;
+ /** Is the source address valid? */
+ bool valid;
+ /** BFD sessions using this. */
+ size_t refcount;
+
+ SLIST_ENTRY(bfd_source_cache) entry;
+};
+SLIST_HEAD(bfd_source_list, bfd_source_cache);
+
/**
* Data structure to do the necessary tricks to hide the BFD protocol
* integration internals.
* Next event.
*
* This variable controls what action to execute when the command batch
- * finishes. Normally we'd use `thread_add_event` value, however since
+ * finishes. Normally we'd use `event_add_event` value, however since
* that function is going to be called multiple times and the value
* might be different we'll use this variable to keep track of it.
*/
* configuration load or northbound batch), so we'll use this to
* install/uninstall the BFD session parameters only once.
*/
- struct thread *installev;
+ struct event *installev;
/** BFD session installation state. */
bool installed;
+ /** Automatic source selection. */
+ bool auto_source;
+ /** Currently selected source. */
+ struct bfd_source_cache *source_cache;
+
/** Global BFD paramaters list. */
TAILQ_ENTRY(bfd_session_params) entry;
};
* without code duplication among daemons.
*/
TAILQ_HEAD(bsplist, bfd_session_params) bsplist;
+ /** BFD automatic source selection cache. */
+ struct bfd_source_list source_list;
/** Pointer to FRR's event manager. */
- struct thread_master *tm;
+ struct event_loop *tm;
/** Pointer to zebra client data structure. */
struct zclient *zc;
/** Global empty address for IPv4/IPv6. */
static const struct in6_addr i6a_zero;
+/*
+ * Prototypes
+ */
+
+static void bfd_source_cache_get(struct bfd_session_params *session);
+static void bfd_source_cache_put(struct bfd_session_params *session);
+
/*
* bfd_get_peer_info - Extract the Peer information for which the BFD session
* went down from the message sent from Zebra to clients.
return true;
}
-static int _bfd_sess_send(struct thread *t)
+static void _bfd_sess_send(struct event *t)
{
- struct bfd_session_params *bsp = THREAD_ARG(t);
+ struct bfd_session_params *bsp = EVENT_ARG(t);
int rv;
/* Validate configuration before trying to send bogus data. */
if (!_bfd_sess_valid(bsp))
- return 0;
+ return;
if (bsp->lastev == BSE_INSTALL) {
bsp->args.command = bsp->installed ? ZEBRA_BFD_DEST_UPDATE
/* If not installed and asked for uninstall, do nothing. */
if (!bsp->installed && bsp->args.command == ZEBRA_BFD_DEST_DEREGISTER)
- return 0;
+ return;
rv = zclient_bfd_command(bsglobal.zc, &bsp->args);
/* Command was sent successfully. */
bsp->lastev == BSE_INSTALL ? "installed"
: "uninstalled");
}
-
- return 0;
}
static void _bfd_sess_remove(struct bfd_session_params *bsp)
{
+ /* Cancel any pending installation request. */
+ EVENT_OFF(bsp->installev);
+
/* Not installed, nothing to do. */
if (!bsp->installed)
return;
- /* Cancel any pending installation request. */
- THREAD_OFF(bsp->installev);
-
/* Send request to remove any session. */
bsp->lastev = BSE_UNINSTALL;
- thread_execute(bsglobal.tm, _bfd_sess_send, bsp, 0);
+ event_execute(bsglobal.tm, _bfd_sess_send, bsp, 0);
}
void bfd_sess_free(struct bfd_session_params **bsp)
/* Remove from global list. */
TAILQ_REMOVE(&bsglobal.bsplist, (*bsp), entry);
+ bfd_source_cache_put(*bsp);
+
/* Free the memory and point to NULL. */
XFREE(MTYPE_BFD_INFO, (*bsp));
}
/* If already installed, remove the old setting. */
_bfd_sess_remove(bsp);
+ /* Address changed so we must reapply auto source. */
+ bfd_source_cache_put(bsp);
bsp->args.family = AF_INET;
assert(dst);
memcpy(&bsp->args.dst, dst, sizeof(struct in_addr));
+
+ if (bsp->auto_source)
+ bfd_source_cache_get(bsp);
}
void bfd_sess_set_ipv6_addrs(struct bfd_session_params *bsp,
/* If already installed, remove the old setting. */
_bfd_sess_remove(bsp);
+ /* Address changed so we must reapply auto source. */
+ bfd_source_cache_put(bsp);
bsp->args.family = AF_INET6;
assert(dst);
bsp->args.dst = *dst;
+
+ if (bsp->auto_source)
+ bfd_source_cache_get(bsp);
}
void bfd_sess_set_interface(struct bfd_session_params *bsp, const char *ifname)
/* If already installed, remove the old setting. */
_bfd_sess_remove(bsp);
+ /* Address changed so we must reapply auto source. */
+ bfd_source_cache_put(bsp);
bsp->args.vrf_id = vrf_id;
+
+ if (bsp->auto_source)
+ bfd_source_cache_get(bsp);
}
void bfd_sess_set_hop_count(struct bfd_session_params *bsp, uint8_t hops)
bsp->args.min_tx = min_tx;
}
+void bfd_sess_set_auto_source(struct bfd_session_params *bsp, bool enable)
+{
+ if (bsp->auto_source == enable)
+ return;
+
+ bsp->auto_source = enable;
+ if (enable)
+ bfd_source_cache_get(bsp);
+ else
+ bfd_source_cache_put(bsp);
+}
+
void bfd_sess_install(struct bfd_session_params *bsp)
{
bsp->lastev = BSE_INSTALL;
- thread_add_event(bsglobal.tm, _bfd_sess_send, bsp, 0, &bsp->installev);
+ event_add_event(bsglobal.tm, _bfd_sess_send, bsp, 0, &bsp->installev);
}
void bfd_sess_uninstall(struct bfd_session_params *bsp)
{
bsp->lastev = BSE_UNINSTALL;
- thread_add_event(bsglobal.tm, _bfd_sess_send, bsp, 0, &bsp->installev);
+ event_add_event(bsglobal.tm, _bfd_sess_send, bsp, 0, &bsp->installev);
}
enum bfd_session_state bfd_sess_status(const struct bfd_session_params *bsp)
*min_tx = bsp->args.min_tx;
}
+bool bfd_sess_auto_source(const struct bfd_session_params *bsp)
+{
+ return bsp->auto_source;
+}
+
void bfd_sess_show(struct vty *vty, struct json_object *json,
struct bfd_session_params *bsp)
{
bsp->installed = false;
/* Cancel any pending installation request. */
- THREAD_OFF(bsp->installev);
+ EVENT_OFF(bsp->installev);
/* Ask for installation. */
bsp->lastev = BSE_INSTALL;
- thread_execute(bsglobal.tm, _bfd_sess_send, bsp, 0);
+ event_execute(bsglobal.tm, _bfd_sess_send, bsp, 0);
}
return 0;
return 0;
}
-void bfd_protocol_integration_init(struct zclient *zc, struct thread_master *tm)
+/**
+ * Frees all allocated resources and stops any activity.
+ *
+ * Must be called after every BFD session has been successfully
+ * unconfigured otherwise this function will `free()` any available
+ * session causing existing pointers to dangle.
+ *
+ * This is just a comment, in practice it will be called by the FRR
+ * library late finish hook. \see `bfd_protocol_integration_init`.
+ */
+static int bfd_protocol_integration_finish(void)
+{
+ if (bsglobal.zc == NULL)
+ return 0;
+
+ while (!TAILQ_EMPTY(&bsglobal.bsplist)) {
+ struct bfd_session_params *session =
+ TAILQ_FIRST(&bsglobal.bsplist);
+ bfd_sess_free(&session);
+ }
+
+ /*
+ * BFD source cache is linked to sessions, if all sessions are gone
+ * then the source cache must be empty.
+ */
+ if (!SLIST_EMPTY(&bsglobal.source_list))
+ zlog_warn("BFD integration source cache not empty");
+
+ return 0;
+}
+
+void bfd_protocol_integration_init(struct zclient *zc, struct event_loop *tm)
{
/* Initialize data structure. */
TAILQ_INIT(&bsglobal.bsplist);
+ SLIST_INIT(&bsglobal.source_list);
/* Copy pointers. */
bsglobal.zc = zc;
/* Send the client registration */
bfd_client_sendmsg(zc, ZEBRA_BFD_CLIENT_REGISTER, VRF_DEFAULT);
+
+ hook_register(frr_fini, bfd_protocol_integration_finish);
}
void bfd_protocol_integration_set_debug(bool enable)
{
return bsglobal.shutting_down;
}
+
+/*
+ * BFD automatic source selection
+ *
+ * This feature will use the next hop tracking (NHT) provided by zebra
+ * to find out the source address by looking at the output interface.
+ *
+ * When the interface address / routing table change we'll be notified
+ * and be able to update the source address accordingly.
+ *
+ * <daemon> zebra
+ * |
+ * +-----------------+
+ * | BFD session set |
+ * | to auto source |
+ * +-----------------+
+ * |
+ * \ +-----------------+
+ * --------------> | Resolves |
+ * | destination |
+ * | address |
+ * +-----------------+
+ * |
+ * +-----------------+ /
+ * | Sets resolved | <----------
+ * | source address |
+ * +-----------------+
+ */
+static bool
+bfd_source_cache_session_match(const struct bfd_source_cache *source,
+ const struct bfd_session_params *session)
+{
+ const struct in_addr *address;
+ const struct in6_addr *address_v6;
+
+ if (session->args.vrf_id != source->vrf_id)
+ return false;
+ if (session->args.family != source->address.family)
+ return false;
+
+ switch (session->args.family) {
+ case AF_INET:
+ address = (const struct in_addr *)&session->args.dst;
+ if (address->s_addr != source->address.u.prefix4.s_addr)
+ return false;
+ break;
+ case AF_INET6:
+ address_v6 = &session->args.dst;
+ if (memcmp(address_v6, &source->address.u.prefix6,
+ sizeof(struct in6_addr)))
+ return false;
+ break;
+ default:
+ return false;
+ }
+
+ return true;
+}
+
+static struct bfd_source_cache *
+bfd_source_cache_find(vrf_id_t vrf_id, const struct prefix *prefix)
+{
+ struct bfd_source_cache *source;
+
+ SLIST_FOREACH (source, &bsglobal.source_list, entry) {
+ if (source->vrf_id != vrf_id)
+ continue;
+ if (!prefix_same(&source->address, prefix))
+ continue;
+
+ return source;
+ }
+
+ return NULL;
+}
+
+static void bfd_source_cache_get(struct bfd_session_params *session)
+{
+ struct bfd_source_cache *source;
+ struct prefix target = {};
+
+ switch (session->args.family) {
+ case AF_INET:
+ target.family = AF_INET;
+ target.prefixlen = IPV4_MAX_BITLEN;
+ memcpy(&target.u.prefix4, &session->args.dst,
+ sizeof(struct in_addr));
+ break;
+ case AF_INET6:
+ target.family = AF_INET6;
+ target.prefixlen = IPV6_MAX_BITLEN;
+ memcpy(&target.u.prefix6, &session->args.dst,
+ sizeof(struct in6_addr));
+ break;
+ default:
+ return;
+ }
+
+ source = bfd_source_cache_find(session->args.vrf_id, &target);
+ if (source) {
+ if (session->source_cache == source)
+ return;
+
+ bfd_source_cache_put(session);
+ session->source_cache = source;
+ source->refcount++;
+ return;
+ }
+
+ source = XCALLOC(MTYPE_BFD_SOURCE, sizeof(*source));
+ prefix_copy(&source->address, &target);
+ source->vrf_id = session->args.vrf_id;
+ SLIST_INSERT_HEAD(&bsglobal.source_list, source, entry);
+
+ bfd_source_cache_put(session);
+ session->source_cache = source;
+ source->refcount = 1;
+
+ return;
+}
+
+static void bfd_source_cache_put(struct bfd_session_params *session)
+{
+ if (session->source_cache == NULL)
+ return;
+
+ session->source_cache->refcount--;
+ if (session->source_cache->refcount > 0) {
+ session->source_cache = NULL;
+ return;
+ }
+
+ SLIST_REMOVE(&bsglobal.source_list, session->source_cache,
+ bfd_source_cache, entry);
+ XFREE(MTYPE_BFD_SOURCE, session->source_cache);
+}
+
+/** Updates BFD running session if source address has changed. */
+static void
+bfd_source_cache_update_session(const struct bfd_source_cache *source,
+ struct bfd_session_params *session)
+{
+ const struct in_addr *address;
+ const struct in6_addr *address_v6;
+
+ switch (session->args.family) {
+ case AF_INET:
+ address = (const struct in_addr *)&session->args.src;
+ if (memcmp(address, &source->source.u.prefix4,
+ sizeof(struct in_addr)) == 0)
+ return;
+
+ _bfd_sess_remove(session);
+ memcpy(&session->args.src, &source->source.u.prefix4,
+ sizeof(struct in_addr));
+ break;
+ case AF_INET6:
+ address_v6 = &session->args.src;
+ if (memcmp(address_v6, &source->source.u.prefix6,
+ sizeof(struct in6_addr)) == 0)
+ return;
+
+ _bfd_sess_remove(session);
+ memcpy(&session->args.src, &source->source.u.prefix6,
+ sizeof(struct in6_addr));
+ break;
+ default:
+ return;
+ }
+
+ bfd_sess_install(session);
+}
+
+static void
+bfd_source_cache_update_sessions(const struct bfd_source_cache *source)
+{
+ struct bfd_session_params *session;
+
+ if (!source->valid)
+ return;
+
+ TAILQ_FOREACH (session, &bsglobal.bsplist, entry) {
+ if (!session->auto_source)
+ continue;
+ if (!bfd_source_cache_session_match(source, session))
+ continue;
+
+ bfd_source_cache_update_session(source, session);
+ }
+}
+
+/**
+ * Try to translate next hop information into source address.
+ *
+ * \returns `true` if source changed otherwise `false`.
+ */
+static bool bfd_source_cache_update(struct bfd_source_cache *source,
+ const struct zapi_route *route)
+{
+ size_t nh_index;
+
+ for (nh_index = 0; nh_index < route->nexthop_num; nh_index++) {
+ const struct zapi_nexthop *nh = &route->nexthops[nh_index];
+ const struct interface *interface;
+ const struct connected *connected;
+ const struct listnode *node;
+
+ interface = if_lookup_by_index(nh->ifindex, nh->vrf_id);
+ if (interface == NULL) {
+ zlog_err("next hop interface not found (index %d)",
+ nh->ifindex);
+ continue;
+ }
+
+ for (ALL_LIST_ELEMENTS_RO(interface->connected, node,
+ connected)) {
+ if (source->address.family !=
+ connected->address->family)
+ continue;
+ if (prefix_same(connected->address, &source->source))
+ return false;
+ /*
+ * Skip link-local as it is only useful for single hop
+ * and in that case no source is specified usually.
+ */
+ if (source->address.family == AF_INET6 &&
+ IN6_IS_ADDR_LINKLOCAL(
+ &connected->address->u.prefix6))
+ continue;
+
+ prefix_copy(&source->source, connected->address);
+ source->valid = true;
+ return true;
+ }
+ }
+
+ memset(&source->source, 0, sizeof(source->source));
+ source->valid = false;
+ return false;
+}
+
+int bfd_nht_update(const struct prefix *match, const struct zapi_route *route)
+{
+ struct bfd_source_cache *source;
+
+ if (bsglobal.debugging)
+ zlog_debug("BFD NHT update for %pFX", &route->prefix);
+
+ SLIST_FOREACH (source, &bsglobal.source_list, entry) {
+ if (source->vrf_id != route->vrf_id)
+ continue;
+ if (!prefix_same(match, &source->address))
+ continue;
+ if (bfd_source_cache_update(source, route))
+ bfd_source_cache_update_sessions(source);
+ }
+
+ return 0;
+}
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