bgpd: put BGP keepalives in a pthread

[mirror_frr.git] / bgpd / bgp_keepalives.h

diff --git a/bgpd/bgp_keepalives.h b/bgpd/bgp_keepalives.h
new file mode 100644 (file)
index 0000000..281c32f
--- /dev/null
+++ b/bgpd/bgp_keepalives.h
@@ -0,0 +1,83 @@
+/* BGP Keepalives.
+ *
+ * Implemented server-style in a pthread.
+ * --------------------------------------
+ * Copyright (C) 2017 Cumulus Networks, Inc.
+ *
+ * This file is part of Free Range Routing.
+ *
+ * Free Range Routing 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.
+ *
+ * Free Range Routing 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 GN5U General Public License along
+ * with Free Range Routing; see the file COPYING.  If not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+#ifndef _BGP_KEEPALIVES_H_
+#define _BGP_KEEPALIVES_H_
+
+#include "bgpd.h"
+
+/* Thread control flag.
+ *
+ * Setting this flag to 'false' while the thread is running will result in
+ * thread termination.
+ */
+extern bool bgp_keepalives_thread_run;
+
+/* Turns on keepalives for a peer.
+ *
+ * This function adds the peer to an internal list of peers to generate
+ * keepalives for.
+ *
+ * At set intervals, a BGP KEEPALIVE packet is generated and placed on
+ * peer->obuf. This operation is thread-safe with respect to peer->obuf.
+ *
+ * peer->v_keepalive determines the interval. Changing this value before
+ * unregistering this peer with peer_keepalives_off() results in undefined
+ * behavior.
+ *
+ * If the peer is already registered for keepalives via this function, nothing
+ * happens.
+ */
+extern void peer_keepalives_on(struct peer *);
+
+/* Turns off keepalives for a peer.
+ *
+ * Removes the peer from the internal list of peers to generate keepalives for.
+ *
+ * If the peer is already unregistered for keepalives, nothing happens.
+ */
+extern void peer_keepalives_off(struct peer *);
+
+/* Entry function for keepalives pthread.
+ *
+ * This function loops over an internal list of peers, generating keepalives at
+ * regular intervals as determined by each peer's keepalive timer.
+ *
+ * See peer_keepalives_on() for additional details.
+ *
+ * @param arg pthread arg, not used
+ */
+extern void *peer_keepalives_start(void *arg);
+
+/* Poking function for keepalives pthread.
+ *
+ * Under normal circumstances the pthread will automatically wake itself
+ * whenever it is necessary to do work. This function may be used to force the
+ * thread to wake up and see if there is any work to do, or if it is time to
+ * die.
+ *
+ * It is not necessary to call this after peer_keepalives_on().
+ */
+extern void peer_keepalives_wake(void);
+
+#endif /* _BGP_KEEPALIVES_H */