vrrpd/vrrp.h

   1 /*
   2  * VRRPD global definitions and state machine
   3  * Copyright (C) 2018 Cumulus Networks, Inc.
   4  *               Quentin Young
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20 #ifndef _VRRP_H
  21 #define _VRRP_H
  22
  23 #include <zebra.h>
  24
  25 #include "lib/hash.h"
  26 #include "lib/hook.h"
  27 #include "lib/if.h"
  28 #include "lib/linklist.h"
  29 #include "lib/privs.h"
  30 #include "lib/thread.h"
  31
  32 /* Global definitions */
  33 #define VRRP_DEFAULT_ADVINT 100
  34 #define VRRP_DEFAULT_PRIORITY 100
  35 #define VRRP_PRIO_MASTER 255
  36 #define VRRP_MCAST_GROUP "224.0.0.18"
  37 #define VRRP_MCAST_GROUP_HEX 0xe0000012
  38 #define IPPROTO_VRRP 112
  39
  40 /* threadmaster */
  41 extern struct thread_master *master;
  42
  43 /* privileges */
  44 extern struct zebra_privs_t vrrp_privs;
  45
  46 /* Global hash of all Virtual Routers */
  47 struct hash *vrrp_vrouters_hash;
  48
  49 /*
  50  * VRRP Virtual Router
  51  */
  52 struct vrrp_vrouter {
  53         /* Socket */
  54         int sock;
  55
  56         /* Interface */
  57         struct interface *ifp;
  58
  59         /* Virtual Router Identifier */
  60         uint32_t vrid;
  61
  62         /* One or more IPv4 addresses associated with this Virtual Router. */
  63         struct list *v4;
  64
  65         /*
  66          * One ore more IPv6 addresses associated with this Virtual Router. The
  67          * first address must be the Link-Local address associated with the
  68          * virtual router.
  69          */
  70         struct list *v6;
  71
  72         /* Whether this VRRP Router is currently the master */
  73         bool is_master;
  74
  75         /* Priority */
  76         uint8_t priority;
  77
  78         /*
  79          * Time interval between ADVERTISEMENTS (centiseconds). Default is 100
  80          * centiseconds (1 second).
  81          */
  82         uint16_t advertisement_interval;
  83         /*
  84          * Advertisement interval contained in ADVERTISEMENTS received from the
  85          * Master (centiseconds)
  86          */
  87         uint16_t master_adver_interval;
  88
  89         /*
  90          * Time to skew Master_Down_Interval in centiseconds. Calculated as:
  91          * (((256 - priority) * Master_Adver_Interval) / 256)
  92          */
  93         uint16_t skew_time;
  94
  95         /*
  96          * Time interval for Backup to declare Master down (centiseconds).
  97          * Calculated as:
  98          * (3 * Master_Adver_Interval) + Skew_time
  99          */
 100         uint16_t master_down_interval;
 101
 102         /*
 103          * Controls whether a (starting or restarting) higher-priority Backup
 104          * router preempts a lower-priority Master router. Values are True to
 105          * allow preemption and False to prohibit preemption. Default is True.
 106          */
 107         bool preempt_mode;
 108
 109         /*
 110          * Controls whether a virtual router in Master state will accept
 111          * packets addressed to the address owner's IPvX address as its own if
 112          * it is not the IPvX address owner. The default is False.
 113          */
 114         bool accept_mode;
 115
 116         /*
 117          * The MAC address used for the source MAC address in VRRP
 118          * advertisements and advertised in ARP responses as the MAC address to
 119          * use for IP_Addresses.
 120          */
 121         struct ethaddr vr_mac_v4;
 122         struct ethaddr vr_mac_v6;
 123
 124         struct thread *t_master_down_timer;
 125         struct thread *t_adver_timer;
 126
 127         struct {
 128                 int state;
 129         } fsm;
 130 };
 131
 132 /*
 133  * Initialize VRRP global datastructures.
 134  */
 135 void vrrp_init(void);
 136
 137
 138 /* Creation and destruction ------------------------------------------------ */
 139
 140 /*
 141  * Create and register a new VRRP Virtual Router.
 142  *
 143  * ifp
 144  *    Base interface to configure VRRP on
 145  *
 146  * vrid
 147  *    Virtual Router Identifier
 148  */
 149 struct vrrp_vrouter *vrrp_vrouter_create(struct interface *ifp, uint8_t vrid);
 150
 151 /*
 152  * Destroy a VRRP Virtual Router.
 153  */
 154 void vrrp_vrouter_destroy(struct vrrp_vrouter *vr);
 155
 156
 157 /* Configuration controllers ----------------------------------------------- */
 158
 159 /*
 160  * Change the priority of a VRRP Virtual Router.
 161  *
 162  * Also recalculates timers using new priority.
 163  *
 164  * vr
 165  *    Virtual Router to change priority of
 166  *
 167  * priority
 168  *    New priority
 169  */
 170 void vrrp_set_priority(struct vrrp_vrouter *vr, uint8_t priority);
 171
 172 /*
 173  * Set Advertisement Interval on this Virtual Router.
 174  *
 175  * vr
 176  *    Virtual Router to change priority of
 177  *
 178  * advertisement_interval
 179  *    New advertisement interval
 180  */
 181 void vrrp_set_advertisement_interval(struct vrrp_vrouter *vr,
 182                                      uint16_t advertisement_interval);
 183
 184 /*
 185  * Add IPv4 address to a VRRP Virtual Router.
 186  *
 187  * vr
 188  *    Virtual Router to add IPv4 address to
 189  *
 190  * v4
 191  *    Address to add
 192  */
 193 void vrrp_add_ip(struct vrrp_vrouter *vr, struct in_addr v4);
 194
 195
 196 /* State machine ----------------------------------------------------------- */
 197
 198 #define VRRP_STATE_INITIALIZE 1
 199 #define VRRP_STATE_MASTER 2
 200 #define VRRP_STATE_BACKUP 3
 201 #define VRRP_EVENT_STARTUP 1
 202 #define VRRP_EVENT_SHUTDOWN 2
 203
 204 /*
 205  * This hook called whenever the state of a Virtual Router changes, after the
 206  * specific internal state handlers have run.
 207  *
 208  * Use this if you need to react to state changes to perform non-critical
 209  * tasks. Critical tasks should go in the internal state change handlers.
 210  */
 211 DECLARE_HOOK(vrrp_change_state_hook, (struct vrrp_vrouter *vr, int to), (vr, to));
 212
 213 /*
 214  * Trigger a VRRP event on a given Virtual Router..
 215  *
 216  * vr
 217  *    Virtual Router to operate on
 218  *
 219  * event
 220  *    Event to kick off. All event related processing will have completed upon
 221  *    return of this function.
 222  *
 223  * Returns:
 224  *    < 0 if the event created an error
 225  *      0 otherwise
 226  */
 227 int vrrp_event(struct vrrp_vrouter *vr, int event);
 228
 229
 230 /* Other ------------------------------------------------------------------- */
 231
 232 /*
 233  * Find VRRP Virtual Router by Virtual Router ID
 234  */
 235 struct vrrp_vrouter *vrrp_lookup(uint8_t vrid);
 236
 237 #endif /* _VRRP_H */