Better support for multitable protocols.

The nest-protocol interaction is changed to better handle multitable
protocols. Multitable protocols now declare that by 'multitable' field,
which tells nest that a protocol handles things related to proto-rtable
interaction (table locking, announce hook adding, reconfiguration of
filters) itself.

Filters and stats are moved to announce hooks, a protocol could have
different filters and stats to different tables.

The patch is based on one from Alexander V. Chernikov, thanks.

1 files changed, 122 insertions, 88 deletions

diff --git a/nest/proto.c b/nest/proto.c
index 0fc72ce1..9a7f123e 100644
--- a/nest/proto.c
+++ b/nest/proto.c
@@ -112,8 +112,6 @@ proto_new(struct proto_config *c, unsigned size)
   p->disabled = c->disabled;
   p->proto = pr;
   p->table = c->table->table;
-  p->in_filter = c->in_filter;
-  p->out_filter = c->out_filter;
   p->hash_key = random_u32();
   c->proto = p;
   return p;
@@ -126,49 +124,102 @@ proto_init_instance(struct proto *p)
   p->pool = rp_new(proto_pool, p->proto->name);
   p->attn = ev_new(p->pool);
   p->attn->data = p;
-  rt_lock_table(p->table);
+
+  if (! p->proto->multitable)
+    rt_lock_table(p->table);
 }
 
+extern pool *rt_table_pool;
 /**
  * proto_add_announce_hook - connect protocol to a routing table
  * @p: protocol instance
  * @t: routing table to connect to
+ * @in: input filter
+ * @out: output filter
+ * @stats: per-table protocol statistics
  *
  * This function creates a connection between the protocol instance @p
  * and the routing table @t, making the protocol hear all changes in
  * the table.
  *
+ * The announce hook is linked in the protocol ahook list and, if the
+ * protocol accepts routes, also in the table ahook list. Announce
+ * hooks are allocated from the routing table resource pool, they are
+ * unlinked from the table ahook list after the protocol went down,
+ * (in proto_schedule_flush()) and they are automatically freed after the
+ * protocol is flushed (in proto_fell_down()).
+ *
  * Unless you want to listen to multiple routing tables (as the Pipe
  * protocol does), you needn't to worry about this function since the
  * connection to the protocol's primary routing table is initialized
  * automatically by the core code.
  */
 struct announce_hook *
-proto_add_announce_hook(struct proto *p, struct rtable *t)
+proto_add_announce_hook(struct proto *p, struct rtable *t, struct filter *in,
+			struct filter *out, struct proto_stats *stats)
 {
   struct announce_hook *h;
 
-  if (!p->rt_notify)
-    return NULL;
   DBG("Connecting protocol %s to table %s\n", p->name, t->name);
   PD(p, "Connected to table %s", t->name);
-  h = mb_alloc(p->pool, sizeof(struct announce_hook));
+
+  h = mb_allocz(rt_table_pool, sizeof(struct announce_hook));
   h->table = t;
   h->proto = p;
+  h->in_filter = in;
+  h->out_filter = out;
+  h->stats = stats;
+
   h->next = p->ahooks;
   p->ahooks = h;
-  add_tail(&t->hooks, &h->n);
+
+  if (p->rt_notify)
+    add_tail(&t->hooks, &h->n);
   return h;
 }
 
+/**
+ * proto_find_announce_hook - find announce hooks
+ * @p: protocol instance
+ * @t: routing table
+ *
+ * Returns pointer to announce hook or NULL
+ */
+struct announce_hook *
+proto_find_announce_hook(struct proto *p, struct rtable *t)
+{
+  struct announce_hook *a;
+
+  for (a = p->ahooks; a; a = a->next)
+    if (a->table == t)
+      return a;
+
+  return NULL;
+}
+
 static void
-proto_flush_hooks(struct proto *p)
+proto_unlink_ahooks(struct proto *p)
 {
   struct announce_hook *h;
 
-  for(h=p->ahooks; h; h=h->next)
-    rem_node(&h->n);
+  if (p->rt_notify)
+    for(h=p->ahooks; h; h=h->next)
+      rem_node(&h->n);
+}
+
+static void
+proto_free_ahooks(struct proto *p)
+{
+  struct announce_hook *h, *hn;
+
+  for(h = p->ahooks; h; h = hn)
+  {
+    hn = h->next;
+    mb_free(h);
+  }
+
   p->ahooks = NULL;
+  p->main_ahook = NULL;
 }
 
 /**
@@ -322,6 +373,8 @@ proto_init(struct proto_config *c)
   return q;
 }
 
+int proto_reconfig_type;  /* Hack to propagate type info to pipe reconfigure hook */
+
 static int
 proto_reconfigure(struct proto *p, struct proto_config *oc, struct proto_config *nc, int type)
 {
@@ -336,23 +389,10 @@ proto_reconfigure(struct proto *p, struct proto_config *oc, struct proto_config
       (proto_get_router_id(nc) != proto_get_router_id(oc)))
     return 0;
 
-  int import_changed = (type != RECONFIG_SOFT) && ! filter_same(nc->in_filter, oc->in_filter);
-  int export_changed = (type != RECONFIG_SOFT) && ! filter_same(nc->out_filter, oc->out_filter);
-
-  /* We treat a change in preferences by reimporting routes */
-  if (nc->preference != oc->preference)
-    import_changed = 1;
-
-  /* If the protocol in not UP, it has no routes and we can ignore such changes */
-  if (p->proto_state != PS_UP)
-    import_changed = export_changed = 0;
-
-  /* Without this hook we cannot reload routes and have to restart the protocol */
-  if (import_changed && ! p->reload_routes)
-    return 0;
 
   p->debug = nc->debug;
   p->mrtdump = nc->mrtdump;
+  proto_reconfig_type = type;
 
   /* Execute protocol specific reconfigure hook */
   if (! (p->proto->reconfigure && p->proto->reconfigure(p, nc)))
@@ -362,14 +402,37 @@ proto_reconfigure(struct proto *p, struct proto_config *oc, struct proto_config
   PD(p, "Reconfigured");
   p->cf = nc;
   p->name = nc->name;
-  p->in_filter = nc->in_filter;
-  p->out_filter = nc->out_filter;
   p->preference = nc->preference;
 
+
+  /* Multitable protocols handle rest in their reconfigure hooks */
+  if (p->proto->multitable)
+    return 1;
+
+  /* Update filters in the main announce hook */
+  if (p->main_ahook)
+    {
+      p->main_ahook->in_filter = nc->in_filter;
+      p->main_ahook->out_filter = nc->out_filter;
+    }
+
+  /* Update routes when filters changed. If the protocol in not UP,
+     it has no routes and we can ignore such changes */
+  if ((p->proto_state != PS_UP) || (type == RECONFIG_SOFT))
+    return 1;
+
+  int import_changed = ! filter_same(nc->in_filter, oc->in_filter);
+  int export_changed = ! filter_same(nc->out_filter, oc->out_filter);
+
+  /* We treat a change in preferences by reimporting routes */
+  if (nc->preference != oc->preference)
+    import_changed = 1;
+
   if (import_changed || export_changed)
     log(L_INFO "Reloading protocol %s", p->name);
 
-  if (import_changed && ! p->reload_routes(p))
+  /* If import filter changed, call reload hook */
+  if (import_changed && ! (p->reload_routes && p->reload_routes(p)))
     {
       /* Now, the protocol is reconfigured. But route reload failed
 	 and we have to do regular protocol restart. */
@@ -553,6 +616,7 @@ void
 protos_dump_all(void)
 {
   struct proto *p;
+  struct announce_hook *a;
 
   debug("Protocols:\n");
 
@@ -560,10 +624,14 @@ protos_dump_all(void)
     {
       debug("  protocol %s state %s/%s\n", p->name,
 	    p_states[p->proto_state], c_states[p->core_state]);
-      if (p->in_filter)
-	debug("\tInput filter: %s\n", filter_name(p->in_filter));
-      if (p->out_filter != FILTER_REJECT)
-	debug("\tOutput filter: %s\n", filter_name(p->out_filter));
+      for (a = p->ahooks; a; a = a->next)
+	{
+	  debug("\tTABLE %s\n", a->table->name);
+	  if (a->in_filter)
+	    debug("\tInput filter: %s\n", filter_name(a->in_filter));
+	  if (a->out_filter != FILTER_REJECT)
+	    debug("\tOutput filter: %s\n", filter_name(a->out_filter));
+	}
       if (p->disabled)
 	debug("\tDISABLED\n");
       else if (p->proto->dump)
@@ -647,7 +715,10 @@ proto_fell_down(struct proto *p)
     log(L_ERR "Protocol %s is down but still has %d routes", p->name, p->stats.imp_routes);
 
   bzero(&p->stats, sizeof(struct proto_stats));
-  rt_unlock_table(p->table);
+  proto_free_ahooks(p);
+
+  if (! p->proto->multitable)
+    rt_unlock_table(p->table);
 
   if (p->proto->cleanup)
     p->proto->cleanup(p);
@@ -686,7 +757,7 @@ proto_feed_initial(void *P)
     return;
 
   DBG("Feeding protocol %s\n", p->name);
-  proto_add_announce_hook(p, p->table);
+
   if_feed_baby(p);
   proto_feed_more(P);
 }
@@ -701,7 +772,7 @@ proto_schedule_flush(struct proto *p)
   DBG("%s: Scheduling flush\n", p->name);
   p->core_state = FS_FLUSHING;
   proto_relink(p);
-  proto_flush_hooks(p);
+  proto_unlink_ahooks(p);
   ev_schedule(proto_flush_event);
 }
 
@@ -716,6 +787,11 @@ proto_schedule_feed(struct proto *p, int initial)
   if (!initial)
     p->stats.exp_routes = 0;
 
+  /* Connect protocol to routing table */
+  if (initial && !p->proto->multitable)
+    p->main_ahook = proto_add_announce_hook(p, p->table,
+      p->cf->in_filter, p->cf->out_filter, &p->stats);
+
   proto_relink(p);
   p->attn->hook = initial ? proto_feed_initial : proto_feed_more;
   ev_schedule(p->attn);
@@ -855,9 +931,8 @@ proto_state_name(struct proto *p)
 }
 
 static void
-proto_do_show_stats(struct proto *p)
+proto_show_stats(struct proto_stats *s)
 {
-  struct proto_stats *s = &p->stats;
   cli_msg(-1006, "  Routes:         %u imported, %u exported, %u preferred", 
 	  s->imp_routes, s->exp_routes, s->pref_routes);
   cli_msg(-1006, "  Route change stats:     received   rejected   filtered    ignored   accepted");
@@ -875,47 +950,17 @@ proto_do_show_stats(struct proto *p)
 	  s->exp_withdraws_received, s->exp_withdraws_accepted);
 }
 
-#ifdef CONFIG_PIPE
-static void
-proto_do_show_pipe_stats(struct proto *p)
+void
+proto_show_basic_info(struct proto *p)
 {
-  struct proto_stats *s1 = &p->stats;
-  struct proto_stats *s2 = pipe_get_peer_stats(p);
-
-  /*
-   * Pipe stats (as anything related to pipes) are a bit tricky. There
-   * are two sets of stats - s1 for routes going from the primary
-   * routing table to the secondary routing table ('exported' from the
-   * user point of view) and s2 for routes going in the other
-   * direction ('imported' from the user point of view).
-   *
-   * Each route going through a pipe is, technically, first exported
-   * to the pipe and then imported from that pipe and such operations
-   * are counted in one set of stats according to the direction of the
-   * route propagation. Filtering is done just in the first part
-   * (export). Therefore, we compose stats for one directon for one
-   * user direction from both import and export stats, skipping
-   * immediate and irrelevant steps (exp_updates_accepted,
-   * imp_updates_received, imp_updates_filtered, ...)
-   */
+  // cli_msg(-1006, "  Table:          %s", p->table->name);
+  cli_msg(-1006, "  Preference:     %d", p->preference);
+  cli_msg(-1006, "  Input filter:   %s", filter_name(p->cf->in_filter));
+  cli_msg(-1006, "  Output filter:  %s", filter_name(p->cf->out_filter));
 
-  cli_msg(-1006, "  Routes:         %u imported, %u exported", 
-	  s2->imp_routes, s1->imp_routes);
-  cli_msg(-1006, "  Route change stats:     received   rejected   filtered    ignored   accepted");
-  cli_msg(-1006, "    Import updates:     %10u %10u %10u %10u %10u",
-	  s2->exp_updates_received, s2->exp_updates_rejected + s2->imp_updates_invalid,
-	  s2->exp_updates_filtered, s2->imp_updates_ignored, s2->imp_updates_accepted);
-  cli_msg(-1006, "    Import withdraws:   %10u %10u        --- %10u %10u",
-	  s2->exp_withdraws_received, s2->imp_withdraws_invalid,
-	  s2->imp_withdraws_ignored, s2->imp_withdraws_accepted);
-  cli_msg(-1006, "    Export updates:     %10u %10u %10u %10u %10u",
-	  s1->exp_updates_received, s1->exp_updates_rejected + s1->imp_updates_invalid,
-	  s1->exp_updates_filtered, s1->imp_updates_ignored, s1->imp_updates_accepted);
-  cli_msg(-1006, "    Export withdraws:   %10u %10u        --- %10u %10u",
-	  s1->exp_withdraws_received, s1->imp_withdraws_invalid,
-	  s1->imp_withdraws_ignored, s1->imp_withdraws_accepted);
+  if (p->proto_state != PS_DOWN)
+    proto_show_stats(&p->stats);
 }
-#endif
 
 void
 proto_cmd_show(struct proto *p, unsigned int verbose, int cnt)
@@ -943,22 +988,11 @@ proto_cmd_show(struct proto *p, unsigned int verbose, int cnt)
 	cli_msg(-1006, "  Description:    %s", p->cf->dsc);
       if (p->cf->router_id)
 	cli_msg(-1006, "  Router ID:      %R", p->cf->router_id);
-      cli_msg(-1006, "  Preference:     %d", p->preference);
-      cli_msg(-1006, "  Input filter:   %s", filter_name(p->in_filter));
-      cli_msg(-1006, "  Output filter:  %s", filter_name(p->out_filter));
-
-      if (p->proto_state != PS_DOWN)
-	{
-#ifdef CONFIG_PIPE
-	  if (proto_is_pipe(p))
-	    proto_do_show_pipe_stats(p);
-	  else
-#endif
-	    proto_do_show_stats(p);
-	}
 
       if (p->proto->show_proto_info)
 	p->proto->show_proto_info(p);
+      else
+	proto_show_basic_info(p);
 
       cli_msg(-1006, "");
     }