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  * Initializes data structures and flags for the write thread.
  33  *
  34  * This function must be called from the main thread before
  35  * bgp_writes_start() is invoked.
  36  */
  37 extern void bgp_io_init(void);
  38
  39 /**
  40  * Start function for write thread.
  41  *
  42  * @param arg - unused
  43  */
  44 extern void *bgp_io_start(void *arg);
  45
  46 /**
  47  * Wait until the IO thread is ready to accept jobs.
  48  *
  49  * This function must be called immediately after the thread has been created
  50  * for running. Use of other functions before calling this one will result in
  51  * undefined behavior.
  52  */
  53 extern void bgp_io_wait_running(void);
  54
  55 /**
  56  * Start function for write thread.
  57  *
  58  * Uninitializes all resources and stops the thread.
  59  *
  60  * @param result - where to store data result, unused
  61  */
  62 extern int bgp_io_stop(void **result, struct frr_pthread *fpt);
  63
  64 /**
  65  * Turns on packet writing for a peer.
  66  *
  67  * After this function is called, any packets placed on peer->obuf will be
  68  * written to peer->fd until no more packets remain.
  69  *
  70  * Additionally, it becomes unsafe to perform socket actions on peer->fd.
  71  *
  72  * @param peer - peer to register
  73  */
  74 extern void bgp_writes_on(struct peer *peer);
  75
  76 /**
  77  * Turns off packet writing for a peer.
  78  *
  79  * After this function returns, packets placed on peer->obuf will not be
  80  * written to peer->fd by the I/O thread.
  81  *
  82  * After this function returns it becomes safe to perform socket actions on
  83  * peer->fd.
  84  *
  85  * @param peer - peer to deregister
  86  * @param flush - as described
  87  */
  88 extern void bgp_writes_off(struct peer *peer);
  89
  90 /**
  91  * Turns on packet reading for a peer.
  92  *
  93  * After this function is called, any packets received on peer->fd will be read
  94  * and copied into the FIFO queue peer->ibuf.
  95  *
  96  * Additionally, it becomes unsafe to perform socket actions on peer->fd.
  97  *
  98  * Whenever one or more packets are placed onto peer->ibuf, a task of type
  99  * THREAD_EVENT will be placed on the main thread whose handler is
 100  *
 101  *   bgp_packet.c:bgp_process_packet()
 102  *
 103  * @param peer - peer to register
 104  */
 105 extern void bgp_reads_on(struct peer *peer);
 106
 107 /**
 108  * Turns off packet reading for a peer.
 109  *
 110  * After this function is called, any packets received on peer->fd will not be
 111  * read by the I/O thread.
 112  *
 113  * After this function returns it becomes safe to perform socket actions on
 114  * peer->fd.
 115  *
 116  * @param peer - peer to deregister
 117  */
 118 extern void bgp_reads_off(struct peer *peer);
 119
 120 #endif /* _FRR_BGP_IO_H */