KRT: Improve syncer code to avoid using temporary data in rtable

The old code stored route verdicts and temporary routes directly in
rtable. The new code do not store received routes (it immediately
compares them with exported routes and resolves conflicts) and uses
internal bitmap to keep track of which routes were received and which
needs to be reinstalled.

By not putting 'invalid' temporary routes to rtable, we keep rtable
in consistent state, therefore scan no longer needs to be atomic
operation and could be splitted to multiple events.

diff --git a/nest/route.h b/nest/route.h
index eaaa5c3f643ce8dfba5ed25f1c6fa36e72ac7cd3..d2a07f09741bf0e1714e8c02f49df6ffbbf03135 100644 (file)
--- a/nest/route.h
+++ b/nest/route.h
@@ -37,7 +37,6 @@ struct cli;
 struct fib_node {
   struct fib_node *next;               /* Next in hash chain */
   struct fib_iterator *readers;                /* List of readers of this node */
-  byte flags;                          /* User-defined, will be removed */
   net_addr addr[0];
 };
 

diff --git a/nest/rt-fib.c b/nest/rt-fib.c
index a8800b654dbae94f3138dc2fd8e97c65bd18c08c..76a86e6eefa65b809c49efae0fc2689cbd507297 100644 (file)
--- a/nest/rt-fib.c
+++ b/nest/rt-fib.c
@@ -327,7 +327,6 @@ fib_get(struct fib *f, const net_addr *a)
 
   struct fib_node *e = fib_user_to_node(f, b);
   e->readers = NULL;
-  e->flags = 0;
   fib_insert(f, a, e);
 
   memset(b, 0, f->node_offset);

diff --git a/nest/rt-table.c b/nest/rt-table.c
index 4adc278ec787ea5f0f76089b6fc909b7ade4a628..f95afccd71fce2b0ab179ceab7f70eea91bc2d6a 100644 (file)
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -1687,7 +1687,7 @@ rte_dump(rte *e)
 {
   net *n = e->net;
   debug("%-1N ", n->n.addr);
-  debug("KF=%02x PF=%02x pref=%d ", n->n.flags, e->pflags, e->pref);
+  debug("PF=%02x pref=%d ", e->pflags, e->pref);
   rta_dump(e->attrs);
   if (e->attrs->src->proto->proto->dump_attrs)
     e->attrs->src->proto->proto->dump_attrs(e);

diff --git a/sysdep/unix/krt.c b/sysdep/unix/krt.c
index 842072517d3107870c5811a85c839eeaca426bb0..42dd12f6e22f250835f4a9ac14b54ebde5ca0d58 100644 (file)
--- a/sysdep/unix/krt.c
+++ b/sysdep/unix/krt.c
@@ -625,19 +625,17 @@ krt_same_dest(rte *k, rte *e)
 void
 krt_got_route(struct krt_proto *p, rte *e)
 {
-  net *net = e->net;
-  int verdict;
+  rte *new = NULL, *rt_free = NULL;
+  net *n = e->net;
 
 #ifdef KRT_ALLOW_LEARN
   switch (e->u.krt.src)
     {
     case KRT_SRC_KERNEL:
-      verdict = KRF_IGNORE;
-      goto sentenced;
+      goto ignore;
 
     case KRT_SRC_REDIRECT:
-      verdict = KRF_DELETE;
-      goto sentenced;
+      goto delete;
 
     case  KRT_SRC_ALIEN:
       if (KRT_CF->learn)
@@ -652,58 +650,68 @@ krt_got_route(struct krt_proto *p, rte *e)
 #endif
   /* The rest is for KRT_SRC_BIRD (or KRT_SRC_UNKNOWN) */
 
-  if (net->n.flags & KRF_VERDICT_MASK)
-    {
-      /* Route to this destination was already seen. Strange, but it happens... */
-      krt_trace_in(p, e, "already seen");
-      rte_free(e);
-      return;
-    }
 
+  /* We wait for the initial feed to have correct installed state */
   if (!p->ready)
-    {
-      /* We wait for the initial feed to have correct installed state */
-      verdict = KRF_IGNORE;
-      goto sentenced;
-    }
+    goto ignore;
 
-  if (krt_is_installed(p, net))
-    {
-      rte *new, *rt_free;
+  if (!krt_is_installed(p, n))
+    goto delete;
 
-      new = krt_export_net(p, net, &rt_free);
+  new = krt_export_net(p, n, &rt_free);
 
-      /* TODO: There also may be changes in route eattrs, we ignore that for now. */
+  /* Rejected by filters */
+  if (!new)
+    goto delete;
 
-      if (!new)
-       verdict = KRF_DELETE;
-      else if (!bmap_test(&p->sync_map, new->id) || !krt_same_dest(e, new))
-       verdict = KRF_UPDATE;
-      else
-       verdict = KRF_SEEN;
+  /* Route to this destination was already seen. Strange, but it happens... */
+  if (bmap_test(&p->seen_map, new->id))
+    goto aseen;
 
-      if (rt_free)
-       rte_free(rt_free);
+  /* Mark route as seen */
+  bmap_set(&p->seen_map, new->id);
 
-      lp_flush(krt_filter_lp);
-    }
-  else
-    verdict = KRF_DELETE;
+  /* TODO: There also may be changes in route eattrs, we ignore that for now. */
+  if (!bmap_test(&p->sync_map, new->id) || !krt_same_dest(e, new))
+    goto update;
 
- sentenced:
-  krt_trace_in(p, e, ((char *[]) { "?", "seen", "will be updated", "will be removed", "ignored" }) [verdict]);
-  net->n.flags = (net->n.flags & ~KRF_VERDICT_MASK) | verdict;
-  if (verdict == KRF_UPDATE || verdict == KRF_DELETE)
-    {
-      /* Get a cached copy of attributes and temporarily link the route */
-      rta *a = e->attrs;
-      a->source = RTS_DUMMY;
-      e->attrs = rta_lookup(a);
-      e->next = net->routes;
-      net->routes = e;
-    }
-  else
-    rte_free(e);
+  goto seen;
+
+seen:
+  krt_trace_in(p, e, "seen");
+  goto done;
+
+aseen:
+  krt_trace_in(p, e, "already seen");
+  goto done;
+
+ignore:
+  krt_trace_in(p, e, "ignored");
+  goto done;
+
+update:
+  krt_trace_in(p, new, "updating");
+  krt_replace_rte(p, n, new, e);
+  goto done;
+
+delete:
+  krt_trace_in(p, e, "deleting");
+  krt_replace_rte(p, n, NULL, e);
+  goto done;
+
+done:
+  rte_free(e);
+
+  if (rt_free)
+    rte_free(rt_free);
+
+  lp_flush(krt_filter_lp);
+}
+
+static void
+krt_init_scan(struct krt_proto *p)
+{
+  bmap_reset(&p->seen_map, 1024);
 }
 
 static void
@@ -713,59 +721,24 @@ krt_prune(struct krt_proto *p)
 
   KRT_TRACE(p, D_EVENTS, "Pruning table %s", t->name);
   FIB_WALK(&t->fib, net, n)
+  {
+    if (p->ready && krt_is_installed(p, n) && !bmap_test(&p->seen_map, n->routes->id))
     {
-      int verdict = n->n.flags & KRF_VERDICT_MASK;
-      rte *new, *old, *rt_free = NULL;
+      rte *rt_free = NULL;
+      rte *new = krt_export_net(p, n, &rt_free);
 
-      if (verdict == KRF_UPDATE || verdict == KRF_DELETE)
-       {
-         /* Get a dummy route from krt_got_route() */
-         old = n->routes;
-         n->routes = old->next;
-       }
-      else
-       old = NULL;
-
-      if (verdict == KRF_CREATE || verdict == KRF_UPDATE)
-       {
-         /* We have to run export filter to get proper 'new' route */
-         new = krt_export_net(p, n, &rt_free);
-
-         if (!new)
-           verdict = (verdict == KRF_CREATE) ? KRF_IGNORE : KRF_DELETE;
-       }
-      else
-       new = NULL;
-
-      switch (verdict)
-       {
-       case KRF_CREATE:
-         krt_trace_in(p, new, "reinstalling");
-         krt_replace_rte(p, n, new, NULL);
-         break;
-       case KRF_SEEN:
-       case KRF_IGNORE:
-         /* Nothing happens */
-         break;
-       case KRF_UPDATE:
-         krt_trace_in(p, new, "updating");
-         krt_replace_rte(p, n, new, old);
-         break;
-       case KRF_DELETE:
-         krt_trace_in(p, old, "deleting");
-         krt_replace_rte(p, n, NULL, old);
-         break;
-       default:
-         bug("krt_prune: invalid route status");
-       }
+      if (new)
+      {
+       krt_trace_in(p, new, "installing");
+       krt_replace_rte(p, n, new, NULL);
+      }
 
-      if (old)
-       rte_free(old);
       if (rt_free)
        rte_free(rt_free);
+
       lp_flush(krt_filter_lp);
-      n->n.flags &= ~KRF_VERDICT_MASK;
     }
+  }
   FIB_WALK_END;
 
 #ifdef KRT_ALLOW_LEARN
@@ -823,6 +796,7 @@ static void
 krt_scan(timer *t UNUSED)
 {
   struct krt_proto *p;
+  node *n;
 
   kif_force_scan();
 
@@ -830,14 +804,13 @@ krt_scan(timer *t UNUSED)
   p = SKIP_BACK(struct krt_proto, krt_node, HEAD(krt_proto_list));
   KRT_TRACE(p, D_EVENTS, "Scanning routing table");
 
+  WALK_LIST2(p, n, krt_proto_list, krt_node)
+    krt_init_scan(p);
+
   krt_do_scan(NULL);
 
-  void *q;
-  WALK_LIST(q, krt_proto_list)
-  {
-    p = SKIP_BACK(struct krt_proto, krt_node, q);
+  WALK_LIST2(p, n, krt_proto_list, krt_node)
     krt_prune(p);
-  }
 }
 
 static void
@@ -879,6 +852,7 @@ krt_scan(timer *t)
   kif_force_scan();
 
   KRT_TRACE(p, D_EVENTS, "Scanning routing table");
+  krt_init_scan(p);
   krt_do_scan(p);
   krt_prune(p);
 }
@@ -1095,6 +1069,7 @@ krt_start(struct proto *P)
   }
 
   bmap_init(&p->sync_map, p->p.pool, 1024);
+  bmap_init(&p->seen_map, p->p.pool, 1024);
   add_tail(&krt_proto_list, &p->krt_node);
 
 #ifdef KRT_ALLOW_LEARN

diff --git a/sysdep/unix/krt.h b/sysdep/unix/krt.h
index c5b565f5ced3f9e47eaef4ccf0ec17fbdfbc2879..6066f2f1680b7d84e91916c9561565ebaecd1f4b 100644 (file)
--- a/sysdep/unix/krt.h
+++ b/sysdep/unix/krt.h
@@ -19,15 +19,6 @@ struct kif_proto;
 #include "sysdep/config.h"
 #include CONFIG_INCLUDE_KRTSYS_H
 
-/* Flags stored in net->n.flags, rest are in nest/route.h */
-
-#define KRF_VERDICT_MASK 0x0f
-#define KRF_CREATE 0                   /* Not seen in kernel table */
-#define KRF_SEEN 1                     /* Seen in kernel table during last scan */
-#define KRF_UPDATE 2                   /* Need to update this entry */
-#define KRF_DELETE 3                   /* Should be deleted */
-#define KRF_IGNORE 4                   /* To be ignored */
-
 #define KRT_DEFAULT_ECMP_LIMIT 16
 
 #define EA_KRT_SOURCE  EA_CODE(PROTOCOL_KERNEL, 0)
@@ -66,6 +57,7 @@ struct krt_proto {
 #endif
 
   struct bmap sync_map;                /* Keeps track which exported routes were successfully written to kernel */
+  struct bmap seen_map;                /* Routes seen during last periodic scan */
   node krt_node;               /* Node in krt_proto_list */
   byte af;                     /* Kernel address family (AF_*) */
   byte ready;                  /* Initial feed has been finished */