From 950775f6fa3d569a9d7cd05e33538d35e895d688 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Sun, 15 May 2022 18:09:30 +0200
Subject: Route destination field merged with nexthop attribute; splitting
 flowspec validation result out.

As there is either a nexthop or another destination specification
(or othing in case of ROAs and Flowspec), it may be merged together.
This code is somehow quirky and should be replaced in future by better
implementation of nexthop.

Also flowspec validation result has its own attribute now as it doesn't
have anything to do with route nexthop.
---
 filter/f-inst.c | 79 ++++++++++++++++++++++++++++-----------------------------
 1 file changed, 39 insertions(+), 40 deletions(-)

(limited to 'filter')

diff --git a/filter/f-inst.c b/filter/f-inst.c
index 8ce78a99..c2abd5aa 100644
--- a/filter/f-inst.c
+++ b/filter/f-inst.c
@@ -530,20 +530,24 @@
       STATIC_ATTR;
       ACCESS_RTE;
       ACCESS_EATTRS;
-      struct rta *rta = (*fs->rte)->attrs;
 
       switch (sa.sa_code)
       {
       case SA_NET:	RESULT(sa.type, net, (*fs->rte)->net->n.addr); break;
       case SA_PROTO:	RESULT(sa.type, s, (*fs->rte)->src->proto->name); break;
-      case SA_DEST:	RESULT(sa.type, i, rta->dest); break;
       default:
 	{
-	  struct eattr *nh_ea = ea_find(*fs->eattrs, &ea_gen_nexthop);
-	  struct nexthop *nh = nh_ea ? &((struct nexthop_adata *) nh_ea->u.ptr)->nh : NULL;
+	  struct eattr *nhea = ea_find(*fs->eattrs, &ea_gen_nexthop);
+	  struct nexthop_adata *nhad = nhea ? (struct nexthop_adata *) nhea->u.ptr : NULL;
+	  struct nexthop *nh = nhad ? &nhad->nh : NULL;
 
 	  switch (sa.sa_code)
 	  {
+	    case SA_DEST:
+	      RESULT(sa.type, i, nhad ?
+		  (NEXTHOP_IS_REACHABLE(nhad) ? RTD_UNICAST : nhad->dest)
+		  : RTD_NONE);
+	      break;
 	    case SA_GW:
 	      RESULT(sa.type, ip, nh ? nh->gw : IPA_NONE);
 	      break;
@@ -576,36 +580,33 @@
 
     f_rta_cow(fs);
     {
-      struct rta *rta = (*fs->rte)->attrs;
+      union {
+	struct nexthop_adata nha;
+	struct {
+	  struct adata ad;
+	  struct nexthop nh;
+	  u32 label;
+	};
+      } nha;
+
+      nha.ad = (struct adata) {
+	.length = sizeof (struct nexthop_adata) - sizeof (struct adata),
+      };
 
-      if (sa.sa_code == SA_DEST)
+      eattr *a = NULL;
+
+      switch (sa.sa_code)
+      {
+      case SA_DEST:
 	{
 	  int i = v1.val.i;
 	  if ((i != RTD_BLACKHOLE) && (i != RTD_UNREACHABLE) && (i != RTD_PROHIBIT))
 	    runtime( "Destination can be changed only to blackhole, unreachable or prohibit" );
 
-	  rta->dest = i;
-	  ea_unset_attr(fs->eattrs, 1, &ea_gen_nexthop);
+	  nha.nha.dest = i;
+	  nha.ad.length = NEXTHOP_DEST_SIZE;
+	  break;
 	}
-      else
-      {
-	union {
-	  struct nexthop_adata nha;
-	  struct {
-	    struct adata ad;
-	    struct nexthop nh;
-	    u32 label;
-	  };
-	} nha;
-
-	nha.ad = (struct adata) {
-	  .length = sizeof (struct nexthop_adata) - sizeof (struct adata),
-	};
-
-	eattr *a = NULL;
-
-	switch (sa.sa_code)
-	  {
       case SA_GW:
 	{
 	  struct eattr *nh_ea = ea_find(*fs->eattrs, &ea_gen_nexthop);
@@ -618,7 +619,6 @@
 	  if (!n || (n->scope == SCOPE_HOST))
 	    runtime( "Invalid gw address" );
 
-	  rta->dest = RTD_UNICAST;
 	  nha.nh = (struct nexthop) {
 	    .gw = ip,
 	    .iface = n->iface,
@@ -632,7 +632,6 @@
 	  if (!ifa)
 	    runtime( "Invalid iface name" );
 
-	  rta->dest = RTD_UNICAST;
 	  nha.nh = (struct nexthop) {
 	    .iface = ifa,
 	  };
@@ -666,15 +665,16 @@
 	  int i = v1.val.i;
 	  if (i < 1 || i > 256)
 	    runtime( "Setting weight value out of bounds" );
-	  if (rta->dest != RTD_UNICAST)
-	    runtime( "Setting weight needs regular nexthop " );
 
 	  struct eattr *nh_ea = ea_find(*fs->eattrs, &ea_gen_nexthop);
 	  if (!nh_ea)
 	    runtime( "No nexthop to set weight on" );
 
-	  struct nexthop_adata *nhax = (struct nexthop_adata *)
-	    tmp_copy_adata(&((struct nexthop_adata *) nh_ea->u.ptr)->ad);
+	  struct nexthop_adata *nhad = (struct nexthop_adata *) nh_ea->u.ptr;
+	  if (!NEXTHOP_IS_REACHABLE(nhad))
+	    runtime( "Setting weight needs regular nexthop " );
+
+	  struct nexthop_adata *nhax = (struct nexthop_adata *) tmp_copy_adata(&nhad->ad);
 
 	  /* Set weight on all next hops */
 	  NEXTHOP_WALK(nh, nhax)
@@ -687,15 +687,14 @@
 
       default:
 	bug("Invalid static attribute access (%u/%u)", sa.type, sa.sa_code);
-	  }
+      }
 
-	if (!a)
-	  a = ea_set_attr(fs->eattrs,
-	      EA_LITERAL_DIRECT_ADATA(&ea_gen_nexthop, 0, tmp_copy_adata(&nha.ad)));
+      if (!a)
+	a = ea_set_attr(fs->eattrs,
+	    EA_LITERAL_DIRECT_ADATA(&ea_gen_nexthop, 0, tmp_copy_adata(&nha.ad)));
 
-	a->originated = 1;
-	a->fresh = 1;
-      }
+      a->originated = 1;
+      a->fresh = 1;
     }
   }
 
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