lib: BFD integration clean up function

Implement clean up function to be called on shutdown to make daemon exit
clean for valgrind and other memory sanitizers.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

diff --git a/lib/bfd.c b/lib/bfd.c
index 1bd31920f0d38a0b7725e08e2ba1d6656a42dab6..ae402ec5cb8f6a3b119c8ab2a2689ae0da8cbf74 100644 (file)
--- a/lib/bfd.c
+++ b/lib/bfd.c
@@ -29,6 +29,7 @@
 #include "stream.h"
 #include "vrf.h"
 #include "zclient.h"
+#include "libfrr.h"
 #include "table.h"
 #include "vty.h"
 #include "bfd.h"
@@ -1045,6 +1046,40 @@ int zclient_bfd_session_update(ZAPI_CALLBACK_ARGS)
        return 0;
 }
 
+/**
+ * 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");
+
+       zclient_stop(bsglobal.nht_zclient);
+       zclient_free(bsglobal.nht_zclient);
+
+       return 0;
+}
+
 static zclient_handler *const bfd_nht_handlers[] = {
        [ZEBRA_NEXTHOP_UPDATE] = bfd_nht_update,
 };
@@ -1076,6 +1111,8 @@ void bfd_protocol_integration_init(struct zclient *zc, struct thread_master *tm)
        bsglobal.nht_zclient->zebra_connected = bfd_nht_zclient_connected;
        thread_add_timer(tm, bfd_nht_zclient_connect, bsglobal.nht_zclient, 1,
                         &bsglobal.nht_zclient->t_connect);
+
+       hook_register(frr_fini, bfd_protocol_integration_finish);
 }
 
 void bfd_protocol_integration_set_debug(bool enable)