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/*
* vrrp_periodic.c - vrrp plug-in periodic function
*
* Copyright 2019-2020 Rubicon Communications, LLC (Netgate)
*
* SPDX-License-Identifier: Apache-2.0
*
*/
#include <vlib/vlib.h>
#include <vppinfra/error.h>
#include <vrrp/vrrp.h>
#include <vrrp/vrrp_packet.h>
static int
vrrp_vr_timer_compare (const void *v1, const void *v2)
{
vrrp_main_t *vmp = &vrrp_main;
const u32 *idx1, *idx2;
vrrp_vr_timer_t *timer1, *timer2;
idx1 = v1;
idx2 = v2;
timer1 = pool_elt_at_index (vmp->vr_timers, *idx1);
timer2 = pool_elt_at_index (vmp->vr_timers, *idx2);
/* don't check equality, they are unlikely to be exactly equal and
* if it occurs, it won't matter what order they were in.
* sort the list in reverse so we can pick the next timer off the end */
if (timer1->expire_time > timer2->expire_time)
return -1;
else
return 1;
}
static u32
vrrp_vr_timer_get_next (void)
{
vrrp_main_t *vmp = &vrrp_main;
int n_timers;
n_timers = vec_len (vmp->pending_timers);
if (!n_timers)
return ~0;
return vec_elt (vmp->pending_timers, n_timers - 1);
}
/* cancel an existing timer. This could happen because:
* - adv timer expired on master. another adv should be scheduled.
* - a shutdown event is received
* - a master is preempted by a higher priority master
* - adv received on backup. master down timer should be rescheduled.
*/
void
vrrp_vr_timer_cancel (vrrp_vr_t * vr)
{
vrrp_main_t *vmp = &vrrp_main;
u32 *t;
/* don't search for a timer that was already canceled or never set */
if (vr->runtime.timer_index == ~0)
return;
/* timers stored in descending order, start at the end of the list */
/* vec_foreach_backwards does not deal with 0 pointers, check first */
if (vmp->pending_timers)
vec_foreach_backwards (t, vmp->pending_timers)
{
if (*t == vr->runtime.timer_index)
{
vec_delete (vmp->pending_timers, 1, t - vmp->pending_timers);
break;
}
}
if (!pool_is_free_index (vmp->vr_timers, vr->runtime.timer_index))
pool_put_index (vmp->vr_timers, vr->runtime.timer_index);
vr->runtime.timer_index = ~0;
vlib_process_signal_event (vmp->vlib_main, vrrp_periodic_node.index,
VRRP_EVENT_VR_TIMER_UPDATE, 0);
}
void
vrrp_vr_timer_set (vrrp_vr_t * vr, vrrp_vr_timer_type_t type)
{
vrrp_main_t *vmp = &vrrp_main;
vlib_main_t *vm = vlib_get_main ();
vrrp_vr_timer_t *timer;
f64 now;
/* Each VR should be waiting on at most 1 timer at any given time.
* If there is already a timer set for this VR, cancel it.
*/
if (vr->runtime.timer_index != ~0)
vrrp_vr_timer_cancel (vr);
pool_get (vmp->vr_timers, timer);
vr->runtime.timer_index = timer - vmp->vr_timers;
timer->vr_index = vr - vmp->vrs;
timer->type = type;
now = vlib_time_now (vm);
/* RFC 5798 specifies that timers are in centiseconds, so x / 100.0 */
switch (type)
{
case VRRP_VR_TIMER_ADV:
timer->expire_time = now + (vr->config.adv_interval / 100.0);
break;
case VRRP_VR_TIMER_MASTER_DOWN:
timer->expire_time = now + (vr->runtime.master_down_int / 100.0);
break;
default:
/* should never reach here */
clib_warning ("Unrecognized VRRP timer type (%d)", type);
return;
}
vec_add1 (vmp->pending_timers, vr->runtime.timer_index);
vec_sort_with_function (vmp->pending_timers, vrrp_vr_timer_compare);
vlib_process_signal_event (vmp->vlib_main, vrrp_periodic_node.index,
VRRP_EVENT_VR_TIMER_UPDATE, 0);
}
void
vrrp_vr_timer_timeout (u32 timer_index)
{
vrrp_main_t *vmp = &vrrp_main;
vrrp_vr_timer_t *timer;
vrrp_vr_t *vr;
if (pool_is_free_index (vmp->vr_timers, timer_index))
{
clib_warning ("Timeout on free timer index %u", timer_index);
return;
}
timer = pool_elt_at_index (vmp->vr_timers, timer_index);
vr = pool_elt_at_index (vmp->vrs, timer->vr_index);
switch (timer->type)
{
case VRRP_VR_TIMER_ADV:
vrrp_adv_send (vr, 0);
vrrp_vr_timer_set (vr, VRRP_VR_TIMER_ADV);
break;
case VRRP_VR_TIMER_MASTER_DOWN:
vrrp_vr_transition (vr, VRRP_VR_STATE_MASTER, NULL);
break;
default:
clib_warning ("Unrecognized timer type %d", timer->type);
return;
}
}
static uword
vrrp_periodic_process (vlib_main_t * vm,
vlib_node_runtime_t * rt, vlib_frame_t * f)
{
vrrp_main_t *pm = &vrrp_main;
f64 now;
f64 timeout = 10.0;
uword *event_data = 0;
uword event_type;
u32 next_timer = ~0;
vrrp_vr_timer_t *timer;
while (1)
{
now = vlib_time_now (vm);
if (next_timer == ~0)
{
vlib_process_wait_for_event (vm);
}
else
{
timer = pool_elt_at_index (pm->vr_timers, next_timer);
timeout = timer->expire_time - now;
/*
* Adding a virtual MAC to some NICs can take a significant amount
* of time (~1s). If a lot of VRs enter the master state around the
* same time, the process node can stay active for a very long time
* processing all of the transitions.
*
* Try to force a 10us sleep between processing events to ensure
* that the process node does not prevent API messages and RPCs
* from being handled for an extended period. This prevents
* vlib_process_wait_for_event_or_clock() from returning
* immediately.
*/
vlib_process_wait_for_event_or_clock (vm, clib_max (timeout, 10e-6));
}
event_type = vlib_process_get_events (vm, (uword **) & event_data);
switch (event_type)
{
/* Handle VRRP_EVENT_VR_TIMER_UPDATE */
case VRRP_EVENT_VR_TIMER_UPDATE:
next_timer = vrrp_vr_timer_get_next ();
break;
/* Handle periodic timeouts */
case ~0:
vrrp_vr_timer_timeout (next_timer);
next_timer = vrrp_vr_timer_get_next ();
break;
}
vec_reset_length (event_data);
}
return 0;
}
VLIB_REGISTER_NODE (vrrp_periodic_node) = {
.function = vrrp_periodic_process,
.type = VLIB_NODE_TYPE_PROCESS,
.name = "vrrp-periodic-process",
.process_log2_n_stack_bytes = 17,
};
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
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