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 _FRR_BGP_KEEPALIVES_H
  24 #define _FRR_BGP_KEEPALIVES_H
  25
  26 #include "frr_pthread.h"
  27 #include "bgpd.h"
  28
  29 /**
  30  * Turns on keepalives for a peer.
  31  *
  32  * This function adds the peer to an internal list of peers to generate
  33  * keepalives for.
  34  *
  35  * At set intervals, a BGP KEEPALIVE packet is generated and placed on
  36  * peer->obuf. This operation is thread-safe with respect to peer->obuf.
  37  *
  38  * peer->v_keepalive determines the interval. Changing this value before
  39  * unregistering this peer with bgp_keepalives_off() results in undefined
  40  * behavior.
  41  *
  42  * If the peer is already registered for keepalives via this function, nothing
  43  * happens.
  44  */
  45 extern void bgp_keepalives_on(struct peer *);
  46
  47 /**
  48  * Turns off keepalives for a peer.
  49  *
  50  * Removes the peer from the internal list of peers to generate keepalives for.
  51  *
  52  * If the peer is already unregistered for keepalives, nothing happens.
  53  */
  54 extern void bgp_keepalives_off(struct peer *);
  55
  56 /**
  57  * Pre-run initialization function for keepalives pthread.
  58  *
  59  * Initializes synchronization primitives. This should be called before
  60  * anything else to avoid race conditions.
  61  */
  62 extern void bgp_keepalives_init(void);
  63
  64 /**
  65  * Entry function for keepalives pthread.
  66  *
  67  * This function loops over an internal list of peers, generating keepalives at
  68  * regular intervals as determined by each peer's keepalive timer.
  69  *
  70  * See bgp_keepalives_on() for additional details.
  71  *
  72  * @param arg pthread arg, not used
  73  */
  74 extern void *bgp_keepalives_start(void *arg);
  75
  76 /**
  77  * Poking function for keepalives pthread.
  78  *
  79  * Under normal circumstances the pthread will automatically wake itself
  80  * whenever it is necessary to do work. This function may be used to force the
  81  * thread to wake up and see if there is any work to do, or if it is time to
  82  * die.
  83  *
  84  * It is not necessary to call this after bgp_keepalives_on().
  85  */
  86 extern void bgp_keepalives_wake(void);
  87
  88 /**
  89  * Stops the thread and blocks until it terminates.
  90  */
  91 int bgp_keepalives_stop(struct frr_pthread *fpt, void **result);
  92
  93 #endif /* _FRR_BGP_KEEPALIVES_H */