Nest: Automatic channel reloads based on RPKI changes

If there are roa_check() calls in channel filters, then the channel
subscribes to ROA table notifications, which are sent when ROA tables
are updated (subject to settle time) and trigger channel reload or
refeed.

1 files changed, 158 insertions, 0 deletions

diff --git a/nest/proto.c b/nest/proto.c
index 7b359152..6bd2427b 100644
--- a/nest/proto.c
+++ b/nest/proto.c
@@ -48,6 +48,7 @@ static char *e_states[] = { "DOWN", "FEEDING", "READY" };
 
 extern struct protocol proto_unix_iface;
 
+static void channel_request_reload(struct channel *c);
 static void proto_shutdown_loop(timer *);
 static void proto_rethink_goal(struct proto *p);
 static char *proto_state_name(struct proto *p);
@@ -180,6 +181,8 @@ proto_add_channel(struct proto *p, struct channel_config *cf)
   c->last_state_change = current_time();
   c->reloadable = 1;
 
+  init_list(&c->roa_subscriptions);
+
   CALL(c->channel->init, c, cf);
 
   add_tail(&p->channels, &c->n);
@@ -256,10 +259,15 @@ channel_feed_loop(void *ptr)
   if (c->export_state != ES_FEEDING)
     return;
 
+  /* Start feeding */
   if (!c->feed_active)
+  {
     if (c->proto->feed_begin)
       c->proto->feed_begin(c, !c->refeeding);
 
+    c->refeed_pending = 0;
+  }
+
   // DBG("Feeding protocol %s continued\n", p->name);
   if (!rt_feed_channel(c))
   {
@@ -289,10 +297,133 @@ channel_feed_loop(void *ptr)
 
   if (c->proto->feed_end)
     c->proto->feed_end(c);
+
+  /* Restart feeding */
+  if (c->refeed_pending)
+    channel_request_feeding(c);
+}
+
+
+static void
+channel_roa_in_changed(struct rt_subscription *s)
+{
+  struct channel *c = s->data;
+  int active = c->reload_event && ev_active(c->reload_event);
+
+  CD(c, "Reload triggered by RPKI change%s", active ? " - already active" : "");
+
+  if (!active)
+    channel_request_reload(c);
+  else
+    c->reload_pending = 1;
+}
+
+static void
+channel_roa_out_changed(struct rt_subscription *s)
+{
+  struct channel *c = s->data;
+  int active = (c->export_state == ES_FEEDING);
+
+  CD(c, "Feeding triggered by RPKI change%s", active ? " - already active" : "");
+
+  if (!active)
+    channel_request_feeding(c);
+  else
+    c->refeed_pending = 1;
+}
+
+/* Temporary code, subscriptions should be changed to resources */
+struct roa_subscription {
+  struct rt_subscription s;
+  node roa_node;
+};
+
+static int
+channel_roa_is_subscribed(struct channel *c, rtable *tab, int dir)
+{
+  void (*hook)(struct rt_subscription *) =
+    dir ? channel_roa_in_changed : channel_roa_out_changed;
+
+  struct roa_subscription *s;
+  node *n;
+
+  WALK_LIST2(s, n, c->roa_subscriptions, roa_node)
+    if ((s->s.tab == tab) && (s->s.hook == hook))
+      return 1;
+
+  return 0;
 }
 
 
 static void
+channel_roa_subscribe(struct channel *c, rtable *tab, int dir)
+{
+  if (channel_roa_is_subscribed(c, tab, dir))
+    return;
+
+  struct roa_subscription *s = mb_allocz(c->proto->pool, sizeof(struct roa_subscription));
+
+  s->s.hook = dir ? channel_roa_in_changed : channel_roa_out_changed;
+  s->s.data = c;
+  rt_subscribe(tab, &s->s);
+
+  add_tail(&c->roa_subscriptions, &s->roa_node);
+}
+
+static void
+channel_roa_unsubscribe(struct roa_subscription *s)
+{
+  rt_unsubscribe(&s->s);
+  rem_node(&s->roa_node);
+  mb_free(s);
+}
+
+static void
+channel_roa_subscribe_filter(struct channel *c, int dir)
+{
+  const struct filter *f = dir ? c->in_filter : c->out_filter;
+  struct rtable *tab;
+
+  if ((f == FILTER_ACCEPT) || (f == FILTER_REJECT))
+    return;
+
+  struct filter_iterator fit;
+  FILTER_ITERATE_INIT(&fit, f, c->proto->pool);
+
+  FILTER_ITERATE(&fit, fi)
+  {
+    switch (fi->fi_code)
+    {
+    case FI_ROA_CHECK_IMPLICIT:
+      tab = fi->i_FI_ROA_CHECK_IMPLICIT.rtc->table;
+      channel_roa_subscribe(c, tab, dir);
+      break;
+
+    case FI_ROA_CHECK_EXPLICIT:
+      tab = fi->i_FI_ROA_CHECK_EXPLICIT.rtc->table;
+      channel_roa_subscribe(c, tab, dir);
+      break;
+
+    default:
+      break;
+    }
+  }
+  FILTER_ITERATE_END;
+
+  FILTER_ITERATE_CLEANUP(&fit);
+}
+
+static void
+channel_roa_unsubscribe_all(struct channel *c)
+{
+  struct roa_subscription *s;
+  node *n, *x;
+
+  WALK_LIST2_DELSAFE(s, n, x, c->roa_subscriptions, roa_node)
+    channel_roa_unsubscribe(s);
+}
+
+static void
 channel_start_export(struct channel *c)
 {
   ASSERT(c->channel_state == CS_UP);
@@ -329,11 +460,19 @@ channel_reload_loop(void *ptr)
 {
   struct channel *c = ptr;
 
+  /* Start reload */
+  if (!c->reload_active)
+    c->reload_pending = 0;
+
   if (!rt_reload_channel(c))
   {
     ev_schedule(c->reload_event);
     return;
   }
+
+  /* Restart reload */
+  if (c->reload_pending)
+    channel_request_reload(c);
 }
 
 static void
@@ -400,6 +539,14 @@ channel_do_start(struct channel *c)
 }
 
 static void
+channel_do_up(struct channel *c)
+{
+  /* Register RPKI/ROA subscriptions */
+  channel_roa_subscribe_filter(c, 1);
+  channel_roa_subscribe_filter(c, 0);
+}
+
+static void
 channel_do_flush(struct channel *c)
 {
   rt_schedule_prune(c->table);
@@ -415,6 +562,8 @@ channel_do_flush(struct channel *c)
   c->in_table = NULL;
   c->reload_event = NULL;
   c->out_table = NULL;
+
+  channel_roa_unsubscribe_all(c);
 }
 
 static void
@@ -484,6 +633,7 @@ channel_set_state(struct channel *c, uint state)
     if (!c->gr_wait && c->proto->rt_notify)
       channel_start_export(c);
 
+    channel_do_up(c);
     break;
 
   case CS_FLUSHING:
@@ -694,6 +844,14 @@ channel_reconfigure(struct channel *c, struct channel_config *cf)
   if (c->channel_state != CS_UP)
     goto done;
 
+  /* Update RPKI/ROA subscriptions */
+  if (import_changed || export_changed)
+  {
+    channel_roa_unsubscribe_all(c);
+    channel_roa_subscribe_filter(c, 1);
+    channel_roa_subscribe_filter(c, 0);
+  }
+
   if (reconfigure_type == RECONFIG_SOFT)
   {
     if (import_changed)