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.

2 files changed, 148 insertions, 50 deletions

diff --git a/proto/pipe/pipe.c b/proto/pipe/pipe.c
index fe8618b6..36b06d43 100644
--- a/proto/pipe/pipe.c
+++ b/proto/pipe/pipe.c
@@ -16,6 +16,17 @@
  *
  * To avoid pipe loops, Pipe keeps a `being updated' flag in each routing
  * table.
+ *
+ * A pipe has two announce hooks, the first connected to the main
+ * table, the second connected to the peer table. When a new route is
+ * announced on the main table, it gets checked by an export filter in
+ * ahook 1, and, after that, it is announced to the peer table via
+ * rte_update(), an import filter in ahook 2 is called. When a new
+ * route is announced in the peer table, an export filter in ahook2
+ * and an import filter in ahook 1 are used. Oviously, there is no
+ * need in filtering the same route twice, so both import filters
+ * are set to accept, while user configured 'import' and 'export'
+ * filters are used as export filters in ahooks 2 and 1.
  */
 
 #undef LOCAL_DEBUG
@@ -24,6 +35,7 @@
 #include "nest/iface.h"
 #include "nest/protocol.h"
 #include "nest/route.h"
+#include "nest/cli.h"
 #include "conf/conf.h"
 #include "filter/filter.h"
 #include "lib/string.h"
@@ -34,7 +46,8 @@ static void
 pipe_rt_notify(struct proto *P, rtable *src_table, net *n, rte *new, rte *old, ea_list *attrs)
 {
   struct pipe_proto *p = (struct pipe_proto *) P;
-  rtable *dest = (src_table == P->table) ? p->peer : P->table; /* The other side of the pipe */
+  struct announce_hook *ah = (src_table == P->table) ? p->peer_ahook : P->main_ahook;
+  rtable *dst_table = ah->table;
   struct proto *src;
 
   net *nn;
@@ -44,13 +57,14 @@ pipe_rt_notify(struct proto *P, rtable *src_table, net *n, rte *new, rte *old, e
   if (!new && !old)
     return;
 
-  if (dest->pipe_busy)
+  if (dst_table->pipe_busy)
     {
       log(L_ERR "Pipe loop detected when sending %I/%d to table %s",
-	  n->n.prefix, n->n.pxlen, dest->name);
+	  n->n.prefix, n->n.pxlen, dst_table->name);
       return;
     }
-  nn = net_get(dest, n->n.prefix, n->n.pxlen);
+
+  nn = net_get(dst_table, n->n.prefix, n->n.pxlen);
   if (new)
     {
       memcpy(&a, new->attrs, sizeof(rta));
@@ -85,14 +99,14 @@ pipe_rt_notify(struct proto *P, rtable *src_table, net *n, rte *new, rte *old, e
     }
 
   src_table->pipe_busy = 1;
-  rte_update(dest, nn, &p->p, (p->mode == PIPE_OPAQUE) ? &p->p : src, e);
+  rte_update2(ah, nn, e, (p->mode == PIPE_OPAQUE) ? &p->p : src);
   src_table->pipe_busy = 0;
 }
 
 static int
 pipe_import_control(struct proto *P, rte **ee, ea_list **ea UNUSED, struct linpool *p UNUSED)
 {
-  struct proto *pp = (*ee)->sender;
+  struct proto *pp = (*ee)->sender->proto;
 
   if (pp == P)
     return -1;	/* Avoid local loops automatically */
@@ -112,20 +126,39 @@ pipe_reload_routes(struct proto *P)
   return 1;
 }
 
+static struct proto *
+pipe_init(struct proto_config *C)
+{
+  struct pipe_config *c = (struct pipe_config *) C;
+  struct proto *P = proto_new(C, sizeof(struct pipe_proto));
+  struct pipe_proto *p = (struct pipe_proto *) P;
+
+  p->mode = c->mode;
+  p->peer_table = c->peer->table;
+  P->accept_ra_types = (p->mode == PIPE_OPAQUE) ? RA_OPTIMAL : RA_ANY;
+  P->rt_notify = pipe_rt_notify;
+  P->import_control = pipe_import_control;
+  P->reload_routes = pipe_reload_routes;
+
+  return P;
+}
+
 static int
 pipe_start(struct proto *P)
 {
   struct pipe_proto *p = (struct pipe_proto *) P;
-  struct announce_hook *a;
 
-  /* Clean up the secondary stats */
-  bzero(&p->peer_stats, sizeof(struct proto_stats));
+  /* Lock both tables, unlock is handled in pipe_cleanup() */
+  rt_lock_table(P->table);
+  rt_lock_table(p->peer_table);
 
-  /* Lock the peer table, unlock is handled in pipe_cleanup() */
-  rt_lock_table(p->peer);
+  /* Going directly to PS_UP - prepare for feeding,
+     connect the protocol to both routing tables */
 
-  /* Connect the protocol also to the peer routing table. */
-  a = proto_add_announce_hook(P, p->peer);
+  P->main_ahook = proto_add_announce_hook(P, P->table,
+    FILTER_ACCEPT, P->cf->out_filter, &P->stats);
+  p->peer_ahook = proto_add_announce_hook(P, p->peer_table,
+    FILTER_ACCEPT, P->cf->in_filter,  &p->peer_stats);
 
   return PS_UP;
 }
@@ -134,24 +167,15 @@ static void
 pipe_cleanup(struct proto *P)
 {
   struct pipe_proto *p = (struct pipe_proto *) P;
-  rt_unlock_table(p->peer);
-}
 
-static struct proto *
-pipe_init(struct proto_config *C)
-{
-  struct pipe_config *c = (struct pipe_config *) C;
-  struct proto *P = proto_new(C, sizeof(struct pipe_proto));
-  struct pipe_proto *p = (struct pipe_proto *) P;
+  bzero(&P->stats, sizeof(struct proto_stats));
+  bzero(&p->peer_stats, sizeof(struct proto_stats));
 
-  p->peer = c->peer->table;
-  p->mode = c->mode;
-  P->accept_ra_types = (p->mode == PIPE_OPAQUE) ? RA_OPTIMAL : RA_ANY;
-  P->rt_notify = pipe_rt_notify;
-  P->import_control = pipe_import_control;
-  P->reload_routes = pipe_reload_routes;
+  P->main_ahook = NULL;
+  p->peer_ahook = NULL;
 
-  return P;
+  rt_unlock_table(P->table);
+  rt_unlock_table(p->peer_table);
 }
 
 static void
@@ -165,16 +189,34 @@ pipe_postconfig(struct proto_config *C)
     cf_error("Primary table and peer table must be different");
 }
 
+extern int proto_reconfig_type;
+
 static int
 pipe_reconfigure(struct proto *P, struct proto_config *new)
 {
-  // struct pipe_proto *p = (struct pipe_proto *) P;
-  struct pipe_config *o = (struct pipe_config *) P->cf;
-  struct pipe_config *n = (struct pipe_config *) new;
+  struct pipe_proto *p = (struct pipe_proto *)P;
+  struct proto_config *old = P->cf;
+  struct pipe_config *oc = (struct pipe_config *) old;
+  struct pipe_config *nc = (struct pipe_config *) new;
 
-  if ((o->peer->table != n->peer->table) || (o->mode != n->mode))
+  if ((oc->peer->table != nc->peer->table) || (oc->mode != nc->mode))
     return 0;
 
+  /* Update output filters in ahooks */
+  if (P->main_ahook)
+    P->main_ahook->out_filter = new->out_filter;
+
+  if (p->peer_ahook)
+    p->peer_ahook->out_filter = new->in_filter;
+
+  if ((P->proto_state != PS_UP) || (proto_reconfig_type == RECONFIG_SOFT))
+    return 1;
+  
+  if ((new->preference != old->preference)
+      || ! filter_same(new->in_filter, old->in_filter)
+      || ! filter_same(new->out_filter, old->out_filter))
+    proto_request_feeding(P);
+
   return 1;
 }
 
@@ -190,19 +232,80 @@ pipe_get_status(struct proto *P, byte *buf)
 {
   struct pipe_proto *p = (struct pipe_proto *) P;
 
-  bsprintf(buf, "%c> %s", (p->mode == PIPE_OPAQUE) ? '-' : '=', p->peer->name);
+  bsprintf(buf, "%c> %s", (p->mode == PIPE_OPAQUE) ? '-' : '=', p->peer_table->name);
+}
+
+static void
+pipe_show_stats(struct pipe_proto *p)
+{
+  struct proto_stats *s1 = &p->p.stats;
+  struct proto_stats *s2 = &p->peer_stats;
+
+  /*
+   * Pipe stats (as anything related to pipes) are a bit tricky. There
+   * are two sets of stats - s1 for ahook to the primary routing and
+   * s2 for the ahook to the secondary routing table. The user point
+   * of view is that routes going from the primary routing table to
+   * the secondary routing table are 'exported', while routes going in
+   * the other direction are 'imported'.
+   *
+   * 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, ...).
+   *
+   * Rule of thumb is that stats s1 have the correct 'polarity'
+   * (imp/exp), while stats s2 have switched 'polarity'.
+   */
+
+  cli_msg(-1006, "  Routes:         %u imported, %u exported", 
+	  s1->imp_routes, s2->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 + s1->imp_updates_invalid,
+	  s2->exp_updates_filtered, s1->imp_updates_ignored, s1->imp_updates_accepted);
+  cli_msg(-1006, "    Import withdraws:   %10u %10u        --- %10u %10u",
+	  s2->exp_withdraws_received, s1->imp_withdraws_invalid,
+	  s1->imp_withdraws_ignored, s1->imp_withdraws_accepted);
+  cli_msg(-1006, "    Export updates:     %10u %10u %10u %10u %10u",
+	  s1->exp_updates_received, s1->exp_updates_rejected + s2->imp_updates_invalid,
+	  s1->exp_updates_filtered, s2->imp_updates_ignored, s2->imp_updates_accepted);
+  cli_msg(-1006, "    Export withdraws:   %10u %10u        --- %10u %10u",
+	  s1->exp_withdraws_received, s2->imp_withdraws_invalid,
+	  s2->imp_withdraws_ignored, s2->imp_withdraws_accepted);
+}
+
+static void
+pipe_show_proto_info(struct proto *P)
+{
+  struct pipe_proto *p = (struct pipe_proto *) P;
+
+  // cli_msg(-1006, "  Table:          %s", P->table->name);
+  // cli_msg(-1006, "  Peer table:     %s", p->peer_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));
+
+  if (P->proto_state != PS_DOWN)
+    pipe_show_stats(p);
 }
 
 
 struct protocol proto_pipe = {
-  name:		"Pipe",
-  template:	"pipe%d",
-  preference:	DEF_PREF_PIPE,
-  postconfig:	pipe_postconfig,
-  init:		pipe_init,
-  start:	pipe_start,
-  cleanup:	pipe_cleanup,
-  reconfigure:	pipe_reconfigure,
-  copy_config:  pipe_copy_config,
-  get_status:	pipe_get_status,
+  name:			"Pipe",
+  template:		"pipe%d",
+  multitable:		1,
+  preference:		DEF_PREF_PIPE,
+  postconfig:		pipe_postconfig,
+  init:			pipe_init,
+  start:		pipe_start,
+  cleanup:		pipe_cleanup,
+  reconfigure:		pipe_reconfigure,
+  copy_config:  	pipe_copy_config,
+  get_status:		pipe_get_status,
+  show_proto_info:	pipe_show_proto_info
 };
diff --git a/proto/pipe/pipe.h b/proto/pipe/pipe.h
index fbd21291..50b31698 100644
--- a/proto/pipe/pipe.h
+++ b/proto/pipe/pipe.h
@@ -20,7 +20,8 @@ struct pipe_config {
 
 struct pipe_proto {
   struct proto p;
-  struct rtable *peer;
+  struct rtable *peer_table;
+  struct announce_hook *peer_ahook;	/* Announce hook for direction peer->primary */
   struct proto_stats peer_stats;	/* Statistics for the direction peer->primary */
   int mode;				/* PIPE_OPAQUE or PIPE_TRANSPARENT */
 };
@@ -31,10 +32,4 @@ extern struct protocol proto_pipe;
 static inline int proto_is_pipe(struct proto *p)
 { return p->proto == &proto_pipe; }
 
-static inline struct rtable * pipe_get_peer_table(struct proto *P)
-{ return ((struct pipe_proto *) P)->peer; }
-
-static inline struct proto_stats * pipe_get_peer_stats(struct proto *P)
-{ return &((struct pipe_proto *) P)->peer_stats; }
-
 #endif