bgpd/bgp_keepalives.h

   1 /* BGP Keepalives.
   2  * Implements a producer thread to generate BGP keepalives for peers.
   3  * Copyright (C) 2017 Cumulus Networks, Inc.
   4  * Quentin Young
   5  *
   6  * This file is part of FRRouting.
   7  *
   8  * FRRouting is free software; you can redistribute it and/or modify it under
   9  * the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2, or (at your option) any later
  11  * version.
  12  *
  13  * FRRouting is distributed in the hope that it will be useful, but WITHOUT ANY
  14  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  15  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; see the file COPYING; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #ifndef _BGP_KEEPALIVES_H_
  24 #define _BGP_KEEPALIVES_H_
  25
  26 #include "frr_pthread.h"
  27 #include "bgpd.h"
  28
  29 /* Turns on keepalives for a peer.
  30  *
  31  * This function adds the peer to an internal list of peers to generate
  32  * keepalives for.
  33  *
  34  * At set intervals, a BGP KEEPALIVE packet is generated and placed on
  35  * peer->obuf. This operation is thread-safe with respect to peer->obuf.
  36  *
  37  * peer->v_keepalive determines the interval. Changing this value before
  38  * unregistering this peer with bgp_keepalives_off() results in undefined
  39  * behavior.
  40  *
  41  * If the peer is already registered for keepalives via this function, nothing
  42  * happens.
  43  */
  44 extern void bgp_keepalives_on(struct peer *);
  45
  46 /* Turns off keepalives for a peer.
  47  *
  48  * Removes the peer from the internal list of peers to generate keepalives for.
  49  *
  50  * If the peer is already unregistered for keepalives, nothing happens.
  51  */
  52 extern void bgp_keepalives_off(struct peer *);
  53
  54 /* Pre-run initialization function for keepalives pthread.
  55  *
  56  * Initializes synchronization primitives. This should be called before
  57  * anything else to avoid race conditions.
  58  */
  59 extern void bgp_keepalives_init(void);
  60
  61 /* Entry function for keepalives pthread.
  62  *
  63  * This function loops over an internal list of peers, generating keepalives at
  64  * regular intervals as determined by each peer's keepalive timer.
  65  *
  66  * See bgp_keepalives_on() for additional details.
  67  *
  68  * @param arg pthread arg, not used
  69  */
  70 extern void *bgp_keepalives_start(void *arg);
  71
  72 /* Poking function for keepalives pthread.
  73  *
  74  * Under normal circumstances the pthread will automatically wake itself
  75  * whenever it is necessary to do work. This function may be used to force the
  76  * thread to wake up and see if there is any work to do, or if it is time to
  77  * die.
  78  *
  79  * It is not necessary to call this after bgp_keepalives_on().
  80  */
  81 extern void bgp_keepalives_wake(void);
  82
  83 /**
  84  * Stops the thread and blocks until it terminates.
  85  */
  86 int bgp_keepalives_stop(void **result, struct frr_pthread *fpt);
  87
  88 #endif /* _BGP_KEEPALIVES_H */