vrrp: add plugin providing vrrp support

Type: feature

Add a new plugin to support HA using VRRPv3 (RFC 5798).

Change-Id: Iaa2c37e6172f8f41e9165f178f44d481f6e247b9
Signed-off-by: Matthew Smith <mgsmith@netgate.com>

1 files changed, 228 insertions, 0 deletions

diff --git a/src/plugins/vrrp/vrrp_periodic.c b/src/plugins/vrrp/vrrp_periodic.c
new file mode 100644
index 00000000000..d37347701fe
--- /dev/null
+++ b/src/plugins/vrrp/vrrp_periodic.c
@@ -0,0 +1,228 @@
+/*
+ * 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;
+
+	  vlib_process_wait_for_event_or_clock (vm, timeout);
+	}
+
+      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;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (vrrp_periodic_node) =
+{
+  .function = vrrp_periodic_process,
+  .type = VLIB_NODE_TYPE_PROCESS,
+  .name = "vrrp-periodic-process",
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */