Separate import and receive limits.

They have different behavior w.r.t. filtered routes that are kept.

4 files changed, 73 insertions, 15 deletions

diff --git a/nest/config.Y b/nest/config.Y
index dbd72055..e46b5fb5 100644
--- a/nest/config.Y
+++ b/nest/config.Y
@@ -44,7 +44,7 @@ CF_DECLS
 
 CF_KEYWORDS(ROUTER, ID, PROTOCOL, TEMPLATE, PREFERENCE, DISABLED, DEBUG, ALL, OFF, DIRECT)
 CF_KEYWORDS(INTERFACE, IMPORT, EXPORT, FILTER, NONE, TABLE, STATES, ROUTES, FILTERS)
-CF_KEYWORDS(LIMIT, ACTION, WARN, BLOCK, RESTART, DISABLE, KEEP, FILTERED)
+CF_KEYWORDS(RECEIVE, LIMIT, ACTION, WARN, BLOCK, RESTART, DISABLE, KEEP, FILTERED)
 CF_KEYWORDS(PASSWORD, FROM, PASSIVE, TO, ID, EVENTS, PACKETS, PROTOCOLS, INTERFACES)
 CF_KEYWORDS(PRIMARY, STATS, COUNT, FOR, COMMANDS, PREEXPORT, GENERATE, ROA, MAX, FLUSH)
 CF_KEYWORDS(LISTEN, BGP, V6ONLY, DUAL, ADDRESS, PORT, PASSWORDS, DESCRIPTION, SORTED)
@@ -185,6 +185,7 @@ proto_item:
  | MRTDUMP mrtdump_mask { this_proto->mrtdump = $2; }
  | IMPORT imexport { this_proto->in_filter = $2; }
  | EXPORT imexport { this_proto->out_filter = $2; }
+ | RECEIVE LIMIT limit_spec { this_proto->rx_limit = $3; }
  | IMPORT LIMIT limit_spec { this_proto->in_limit = $3; }
  | EXPORT LIMIT limit_spec { this_proto->out_limit = $3; }
  | IMPORT KEEP FILTERED bool { this_proto->in_keep_filtered = $4; }
diff --git a/nest/proto.c b/nest/proto.c
index b976a6cb..7e7fb7fa 100644
--- a/nest/proto.c
+++ b/nest/proto.c
@@ -344,6 +344,7 @@ protos_postconfig(struct config *c)
   WALK_LIST(x, c->protos)
     {
       DBG(" %s", x->name);
+
       p = x->protocol;
       if (p->postconfig)
 	p->postconfig(x);
@@ -410,6 +411,7 @@ proto_reconfigure(struct proto *p, struct proto_config *oc, struct proto_config
     {
       p->main_ahook->in_filter = nc->in_filter;
       p->main_ahook->out_filter = nc->out_filter;
+      p->main_ahook->rx_limit = nc->rx_limit;
       p->main_ahook->in_limit = nc->in_limit;
       p->main_ahook->out_limit = nc->out_limit;
       p->main_ahook->in_keep_filtered = nc->in_keep_filtered;
@@ -804,9 +806,11 @@ proto_schedule_feed(struct proto *p, int initial)
       p->main_ahook = proto_add_announce_hook(p, p->table, &p->stats);
       p->main_ahook->in_filter = p->cf->in_filter;
       p->main_ahook->out_filter = p->cf->out_filter;
+      p->main_ahook->rx_limit = p->cf->rx_limit;
       p->main_ahook->in_limit = p->cf->in_limit;
       p->main_ahook->out_limit = p->cf->out_limit;
       p->main_ahook->in_keep_filtered = p->cf->in_keep_filtered;
+      proto_reset_limit(p->main_ahook->rx_limit);
       proto_reset_limit(p->main_ahook->in_limit);
       proto_reset_limit(p->main_ahook->out_limit);
     }
@@ -978,6 +982,7 @@ proto_limit_name(struct proto_limit *l)
  * proto_notify_limit: notify about limit hit and take appropriate action
  * @ah: announce hook
  * @l: limit being hit
+ * @dir: limit direction (PLD_*)
  * @rt_count: the number of routes 
  *
  * The function is called by the route processing core when limit @l
@@ -985,10 +990,11 @@ proto_limit_name(struct proto_limit *l)
  * according to @l->action.
  */
 void
-proto_notify_limit(struct announce_hook *ah, struct proto_limit *l, u32 rt_count)
+proto_notify_limit(struct announce_hook *ah, struct proto_limit *l, int dir, u32 rt_count)
 {
+  const char *dir_name[PLD_MAX] = { "receive", "import" , "export" };
+  const byte dir_down[PLD_MAX] = { PDC_RX_LIMIT_HIT, PDC_IN_LIMIT_HIT, PDC_OUT_LIMIT_HIT };
   struct proto *p = ah->proto;
-  int dir = (ah->in_limit == l);
 
   if (l->state == PLS_BLOCKED)
     return;
@@ -996,7 +1002,7 @@ proto_notify_limit(struct announce_hook *ah, struct proto_limit *l, u32 rt_count
   /* For warning action, we want the log message every time we hit the limit */
   if (!l->state || ((l->action == PLA_WARN) && (rt_count == l->limit)))
     log(L_WARN "Protocol %s hits route %s limit (%d), action: %s",
-	p->name, dir ? "import" : "export", l->limit, proto_limit_name(l));
+	p->name, dir_name[dir], l->limit, proto_limit_name(l));
 
   switch (l->action)
     {
@@ -1011,8 +1017,7 @@ proto_notify_limit(struct announce_hook *ah, struct proto_limit *l, u32 rt_count
     case PLA_RESTART:
     case PLA_DISABLE:
       l->state = PLS_BLOCKED;
-      proto_schedule_down(p, l->action == PLA_RESTART,
-			  dir ? PDC_IN_LIMIT_HIT : PDC_OUT_LIMIT_HIT);
+      proto_schedule_down(p, l->action == PLA_RESTART, dir_down[dir]);
       break;
     }
 }
@@ -1146,6 +1151,7 @@ proto_show_basic_info(struct proto *p)
   cli_msg(-1006, "  Input filter:   %s", filter_name(p->cf->in_filter));
   cli_msg(-1006, "  Output filter:  %s", filter_name(p->cf->out_filter));
 
+  proto_show_limit(p->cf->rx_limit, "Receive limit:");
   proto_show_limit(p->cf->in_limit, "Import limit:");
   proto_show_limit(p->cf->out_limit, "Export limit:");
 
@@ -1267,7 +1273,10 @@ proto_cmd_reload(struct proto *p, unsigned int dir, int cnt UNUSED)
        * Perhaps, but these hooks work asynchronously.
        */
       if (!p->proto->multitable)
-	proto_reset_limit(p->main_ahook->in_limit);
+	{
+	  proto_reset_limit(p->main_ahook->rx_limit);
+	  proto_reset_limit(p->main_ahook->in_limit);
+	}
     }
 
   /* re-exporting routes */
diff --git a/nest/protocol.h b/nest/protocol.h
index cf2ca0a4..033a0ede 100644
--- a/nest/protocol.h
+++ b/nest/protocol.h
@@ -95,6 +95,8 @@ struct proto_config {
   u32 router_id;			/* Protocol specific router ID */
   struct rtable_config *table;		/* Table we're attached to */
   struct filter *in_filter, *out_filter; /* Attached filters */
+  struct proto_limit *rx_limit;		/* Limit for receiving routes from protocol
+					   (relevant when in_keep_filtered is active) */
   struct proto_limit *in_limit;		/* Limit for importing routes from protocol */
   struct proto_limit *out_limit;	/* Limit for exporting routes to protocol */
 
@@ -225,8 +227,9 @@ struct proto_spec {
 #define PDC_CMD_DISABLE		0x11	/* Result of disable command */
 #define PDC_CMD_RESTART		0x12	/* Result of restart command */
 #define PDC_CMD_SHUTDOWN	0x13	/* Result of global shutdown */
-#define PDC_IN_LIMIT_HIT	0x21	/* Route import limit reached */
-#define PDC_OUT_LIMIT_HIT	0x22	/* Route export limit reached */
+#define PDC_RX_LIMIT_HIT	0x21	/* Route receive limit reached */
+#define PDC_IN_LIMIT_HIT	0x22	/* Route import limit reached */
+#define PDC_OUT_LIMIT_HIT	0x23	/* Route export limit reached */
 
 
 void *proto_new(struct proto_config *, unsigned size);
@@ -373,6 +376,11 @@ extern struct proto_config *cf_dev_proto;
  * Protocol limits
  */
 
+#define PLD_RX		0	/* Receive limit */
+#define PLD_IN		1	/* Import limit */
+#define PLD_OUT		2	/* Export limit */
+#define PLD_MAX		3
+
 #define PLA_WARN	1	/* Issue log warning */
 #define PLA_BLOCK	2	/* Block new routes */
 #define PLA_RESTART	4	/* Force protocol restart */
@@ -388,7 +396,7 @@ struct proto_limit {
   byte state;			/* State of limit (PLS_*) */
 };
 
-void proto_notify_limit(struct announce_hook *ah, struct proto_limit *l, u32 rt_count);
+void proto_notify_limit(struct announce_hook *ah, struct proto_limit *l, int dir, u32 rt_count);
 
 static inline void
 proto_reset_limit(struct proto_limit *l)
@@ -408,6 +416,7 @@ struct announce_hook {
   struct proto *proto;
   struct filter *in_filter;		/* Input filter */
   struct filter *out_filter;		/* Output filter */
+  struct proto_limit *rx_limit;		/* Receive limit (for in_keep_filtered) */
   struct proto_limit *in_limit;		/* Input limit */
   struct proto_limit *out_limit;	/* Output limit */
   struct proto_stats *stats;		/* Per-table protocol statistics */
diff --git a/nest/rt-table.c b/nest/rt-table.c
index 2f0840f0..99175448 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -285,7 +285,7 @@ do_rt_notify(struct announce_hook *ah, net *net, rte *new, rte *old, ea_list *tm
   if (l && new)
     {
       if ((!old || refeed) && (stats->exp_routes >= l->limit))
-	proto_notify_limit(ah, l, stats->exp_routes);
+	proto_notify_limit(ah, l, PLD_OUT, stats->exp_routes);
 
       if (l->state == PLS_BLOCKED)
 	{
@@ -700,16 +700,22 @@ rte_recalculate(struct announce_hook *ah, net *net, rte *new, ea_list *tmpa, str
       return;
     }
 
-  struct proto_limit *l = ah->in_limit;
+  int new_ok = rte_is_ok(new);
+  int old_ok = rte_is_ok(old);
+
+  struct proto_limit *l = ah->rx_limit;
   if (l && !old && new)
     {
       u32 all_routes = stats->imp_routes + stats->filt_routes;
 
       if (all_routes >= l->limit)
-	proto_notify_limit(ah, l, all_routes);
+	proto_notify_limit(ah, l, PLD_RX, all_routes);
 
       if (l->state == PLS_BLOCKED)
 	{
+	  /* In receive limit the situation is simple, old is NULL so
+	     we just free new and exit like nothing happened */
+
 	  stats->imp_updates_ignored++;
 	  rte_trace_in(D_FILTERS, p, new, "ignored [limit]");
 	  rte_free_quick(new);
@@ -717,8 +723,39 @@ rte_recalculate(struct announce_hook *ah, net *net, rte *new, ea_list *tmpa, str
 	}
     }
 
-  int new_ok = rte_is_ok(new);
-  int old_ok = rte_is_ok(old);
+  l = ah->in_limit;
+  if (l && !old_ok && new_ok)
+    {
+      if (stats->imp_routes >= l->limit)
+	proto_notify_limit(ah, l, PLD_IN, stats->imp_routes);
+
+      if (l->state == PLS_BLOCKED)
+	{
+	  /* In import limit the situation is more complicated. We
+	     shouldn't just drop the route, we should handle it like
+	     it was filtered. We also have to continue the route
+	     processing if old or new is non-NULL, but we should exit
+	     if both are NULL as this case is probably assumed to be
+	     already handled. */
+
+	  stats->imp_updates_ignored++;
+	  rte_trace_in(D_FILTERS, p, new, "ignored [limit]");
+
+	  if (ah->in_keep_filtered)
+	    new->flags |= REF_FILTERED;
+	  else
+	    { rte_free_quick(new); new = NULL; }
+
+	  /* Note that old && !new could be possible when
+	     ah->in_keep_filtered changed in the recent past. */
+
+	  if (!old && !new)
+	    return;
+
+	  new_ok = 0;
+	  goto skip_stats1;
+	}
+    }
 
   if (new_ok)
     stats->imp_updates_accepted++;
@@ -727,6 +764,8 @@ rte_recalculate(struct announce_hook *ah, net *net, rte *new, ea_list *tmpa, str
   else
     stats->imp_withdraws_ignored++;
 
+ skip_stats1:
+
   if (new)
     rte_is_filtered(new) ? stats->filt_routes++ : stats->imp_routes++;
   if (old)