bgpd/bgp_io.h

   1 /* BGP I/O.
   2  * Implements packet I/O in a pthread.
   3  * Copyright (C) 2017  Cumulus Networks
   4  * Quentin Young
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; see the file COPYING; if not, write to the
  18  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  19  * MA 02110-1301 USA
  20  */
  21
  22 #ifndef _FRR_BGP_IO_H
  23 #define _FRR_BGP_IO_H
  24
  25 #define BGP_WRITE_PACKET_MAX 10U
  26 #define BGP_READ_PACKET_MAX  10U
  27
  28 #include "bgpd/bgpd.h"
  29 #include "frr_pthread.h"
  30
  31 /**
  32  * Control variable for write thread.
  33  *
  34  * Setting this variable to false will eventually result in thread termination.
  35  */
  36 extern bool bgp_packet_writes_thread_run;
  37
  38 /**
  39  * Initializes data structures and flags for the write thread.
  40  *
  41  * This function should be called from the main thread before
  42  * bgp_writes_start() is invoked.
  43  */
  44 extern void bgp_io_init(void);
  45
  46 /**
  47  * Start function for write thread.
  48  *
  49  * @param arg - unused
  50  */
  51 extern void *bgp_io_start(void *arg);
  52
  53 /**
  54  * Start function for write thread.
  55  *
  56  * Uninitializes all resources and stops the thread.
  57  *
  58  * @param result - where to store data result, unused
  59  */
  60 extern int bgp_io_stop(void **result, struct frr_pthread *fpt);
  61
  62 /**
  63  * Turns on packet writing for a peer.
  64  *
  65  * After this function is called, any packets placed on peer->obuf will be
  66  * written to peer->fd until no more packets remain.
  67  *
  68  * Additionally, it becomes unsafe to perform socket actions on peer->fd.
  69  *
  70  * @param peer - peer to register
  71  */
  72 extern void bgp_writes_on(struct peer *peer);
  73
  74 /**
  75  * Turns off packet writing for a peer.
  76  *
  77  * After this function returns, packets placed on peer->obuf will not be
  78  * written to peer->fd by the I/O thread.
  79  *
  80  * After this function returns it becomes safe to perform socket actions on
  81  * peer->fd.
  82  *
  83  * @param peer - peer to deregister
  84  * @param flush - as described
  85  */
  86 extern void bgp_writes_off(struct peer *peer);
  87
  88 /**
  89  * Turns on packet reading for a peer.
  90  *
  91  * After this function is called, any packets received on peer->fd will be read
  92  * and copied into the FIFO queue peer->ibuf.
  93  *
  94  * Additionally, it becomes unsafe to perform socket actions on peer->fd.
  95  *
  96  * Whenever one or more packets are placed onto peer->ibuf, a task of type
  97  * THREAD_EVENT will be placed on the main thread whose handler is
  98  *
  99  *   bgp_packet.c:bgp_process_packet()
 100  *
 101  * @param peer - peer to register
 102  */
 103 extern void bgp_reads_on(struct peer *peer);
 104
 105 /**
 106  * Turns off packet reading for a peer.
 107  *
 108  * After this function is called, any packets received on peer->fd will not be
 109  * read by the I/O thread.
 110  *
 111  * After this function returns it becomes safe to perform socket actions on
 112  * peer->fd.
 113  *
 114  * @param peer - peer to deregister
 115  */
 116 extern void bgp_reads_off(struct peer *peer);
 117
 118 #endif /* _FRR_BGP_IO_H */