bgpd/bgp_keepalives.h

   1 /* BGP Keepalives.
   2  *
   3  * Implemented server-style in a pthread.
   4  * --------------------------------------
   5  * Copyright (C) 2017 Cumulus Networks, Inc.
   6  *
   7  * This file is part of Free Range Routing.
   8  *
   9  * Free Range Routing is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by the
  11  * Free Software Foundation; either version 2, or (at your option) any later
  12  * version.
  13  *
  14  * Free Range Routing is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  16  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  17  * more details.
  18  *
  19  * You should have received a copy of the GN5U General Public License along
  20  * with Free Range Routing; see the file COPYING.  If not, write to the Free
  21  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  22  * 02111-1307, USA.
  23  */
  24 #ifndef _BGP_KEEPALIVES_H_
  25 #define _BGP_KEEPALIVES_H_
  26
  27 #include "bgpd.h"
  28
  29 /* Thread control flag.
  30  *
  31  * Setting this flag to 'false' while the thread is running will result in
  32  * thread termination.
  33  */
  34 extern bool bgp_keepalives_thread_run;
  35
  36 /* Turns on keepalives for a peer.
  37  *
  38  * This function adds the peer to an internal list of peers to generate
  39  * keepalives for.
  40  *
  41  * At set intervals, a BGP KEEPALIVE packet is generated and placed on
  42  * peer->obuf. This operation is thread-safe with respect to peer->obuf.
  43  *
  44  * peer->v_keepalive determines the interval. Changing this value before
  45  * unregistering this peer with peer_keepalives_off() results in undefined
  46  * behavior.
  47  *
  48  * If the peer is already registered for keepalives via this function, nothing
  49  * happens.
  50  */
  51 extern void peer_keepalives_on(struct peer *);
  52
  53 /* Turns off keepalives for a peer.
  54  *
  55  * Removes the peer from the internal list of peers to generate keepalives for.
  56  *
  57  * If the peer is already unregistered for keepalives, nothing happens.
  58  */
  59 extern void peer_keepalives_off(struct peer *);
  60
  61 /* Pre-run initialization function for keepalives pthread.
  62  *
  63  * Initializes synchronization primitives. This should be called before
  64  * anything else to avoid race conditions.
  65  */
  66 extern void peer_keepalives_init(void);
  67
  68 /* Entry function for keepalives pthread.
  69  *
  70  * This function loops over an internal list of peers, generating keepalives at
  71  * regular intervals as determined by each peer's keepalive timer.
  72  *
  73  * See peer_keepalives_on() for additional details.
  74  *
  75  * @param arg pthread arg, not used
  76  */
  77 extern void *peer_keepalives_start(void *arg);
  78
  79 /* Poking function for keepalives pthread.
  80  *
  81  * Under normal circumstances the pthread will automatically wake itself
  82  * whenever it is necessary to do work. This function may be used to force the
  83  * thread to wake up and see if there is any work to do, or if it is time to
  84  * die.
  85  *
  86  * It is not necessary to call this after peer_keepalives_on().
  87  */
  88 extern void peer_keepalives_wake(void);
  89
  90 /* stop function */
  91 int peer_keepalives_stop(void **result);
  92
  93 #endif /* _BGP_KEEPALIVES_H */