From f15f2fcee7eeb5a100bd204a0e67018e25953420 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Thu, 5 May 2022 18:08:37 +0200
Subject: [PATCH] Moved nexthop from struct rta to extended attribute.

This doesn't do anything more than to put the whole structure inside
adata. The overall performance is certainly going downhill; we'll
optimize this later.

Anyway, this is one of the latest items inside rta and in several
commits we may drop rta completely and move to eattrs-only routes.
---
 filter/f-inst.c        | 139 +++++++++++++------
 lib/attrs.h            |   2 +
 lib/route.h            |  65 ++++++---
 lib/type.h             |   1 +
 nest/rt-attr.c         | 304 +++++++++++++++--------------------------
 nest/rt-dev.c          |   7 +-
 nest/rt-show.c         |   9 +-
 nest/rt-table.c        | 156 ++++++++++++---------
 proto/babel/babel.c    |  51 ++++---
 proto/bgp/packets.c    |  68 ++++++---
 proto/ospf/rt.c        | 164 +++++++++++-----------
 proto/ospf/rt.h        |   4 +-
 proto/ospf/topology.c  |  16 ++-
 proto/ospf/topology.h  |   4 +-
 proto/perf/perf.c      |  10 +-
 proto/rip/rip.c        |  54 ++++++--
 proto/static/static.c  |  34 +++--
 sysdep/linux/netlink.c | 183 +++++++++++++++----------
 sysdep/unix/krt.c      |  10 +-
 19 files changed, 722 insertions(+), 559 deletions(-)

diff --git a/filter/f-inst.c b/filter/f-inst.c
index 23271ce7..8ce78a99 100644
--- a/filter/f-inst.c
+++ b/filter/f-inst.c
@@ -529,27 +529,47 @@
     {
       STATIC_ATTR;
       ACCESS_RTE;
+      ACCESS_EATTRS;
       struct rta *rta = (*fs->rte)->attrs;
 
       switch (sa.sa_code)
       {
-      case SA_GW:	RESULT(sa.type, ip, rta->nh.gw); break;
       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;
-      case SA_IFNAME:	RESULT(sa.type, s, rta->nh.iface ? rta->nh.iface->name : ""); break;
-      case SA_IFINDEX:	RESULT(sa.type, i, rta->nh.iface ? rta->nh.iface->index : 0); break;
-      case SA_WEIGHT:	RESULT(sa.type, i, rta->nh.weight + 1); break;
-      case SA_GW_MPLS:	RESULT(sa.type, i, rta->nh.labels ? rta->nh.label[0] : MPLS_NULL); break;
-
       default:
-	bug("Invalid static attribute access (%u/%u)", sa.type, sa.sa_code);
+	{
+	  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;
+
+	  switch (sa.sa_code)
+	  {
+	    case SA_GW:
+	      RESULT(sa.type, ip, nh ? nh->gw : IPA_NONE);
+	      break;
+	    case SA_IFNAME:
+	      RESULT(sa.type, s, (nh && nh->iface) ? nh->iface->name : "");
+	      break;
+	    case SA_IFINDEX:
+	      RESULT(sa.type, i, (nh && nh->iface) ? nh->iface->index : 0);
+	      break;
+	    case SA_WEIGHT:
+	      RESULT(sa.type, i, (nh ? nh->weight : 0) + 1);
+	      break;
+	    case SA_GW_MPLS:
+	      RESULT(sa.type, i, (nh && nh->labels) ? nh->label[0] : MPLS_NULL);
+	      break;
+	    default:
+	      bug("Invalid static attribute access (%u/%u)", sa.type, sa.sa_code);
+	  }
+	}
       }
     }
   }
 
   INST(FI_RTA_SET, 1, 0) {
     ACCESS_RTE;
+    ACCESS_EATTRS;
     ARG_ANY(1);
     STATIC_ATTR;
     ARG_TYPE(1, sa.type);
@@ -558,37 +578,51 @@
     {
       struct rta *rta = (*fs->rte)->attrs;
 
-      switch (sa.sa_code)
-      {
-      case SA_GW:
-	{
-	  ip_addr ip = v1.val.ip;
-	  struct iface *ifa = ipa_is_link_local(ip) ? rta->nh.iface : NULL;
-	  neighbor *n = neigh_find((*fs->rte)->src->proto, ip, ifa, 0);
-	  if (!n || (n->scope == SCOPE_HOST))
-	    runtime( "Invalid gw address" );
-
-	  rta->dest = RTD_UNICAST;
-	  rta->nh.gw = ip;
-	  rta->nh.iface = n->iface;
-	  rta->nh.next = NULL;
-	  rta->hostentry = NULL;
-	  rta->nh.labels = 0;
-	}
-	break;
-
-      case SA_DEST:
+      if (sa.sa_code == 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;
-	  rta->nh.gw = IPA_NONE;
-	  rta->nh.iface = NULL;
-	  rta->nh.next = NULL;
-	  rta->hostentry = NULL;
-	  rta->nh.labels = 0;
+	  ea_unset_attr(fs->eattrs, 1, &ea_gen_nexthop);
+	}
+      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);
+
+	  ip_addr ip = v1.val.ip;
+	  struct iface *ifa = (ipa_is_link_local(ip) && nh_ea) ?
+	    ((struct nexthop_adata *) nh_ea->u.ptr)->nh.iface : NULL;
+	  
+	  neighbor *n = neigh_find((*fs->rte)->src->proto, ip, ifa, 0);
+	  if (!n || (n->scope == SCOPE_HOST))
+	    runtime( "Invalid gw address" );
+
+	  rta->dest = RTD_UNICAST;
+	  nha.nh = (struct nexthop) {
+	    .gw = ip,
+	    .iface = n->iface,
+	  };
 	}
 	break;
 
@@ -599,11 +633,9 @@
 	    runtime( "Invalid iface name" );
 
 	  rta->dest = RTD_UNICAST;
-	  rta->nh.gw = IPA_NONE;
-	  rta->nh.iface = ifa;
-	  rta->nh.next = NULL;
-	  rta->hostentry = NULL;
-	  rta->nh.labels = 0;
+	  nha.nh = (struct nexthop) {
+	    .iface = ifa,
+	  };
 	}
 	break;
 
@@ -612,13 +644,20 @@
 	  if (v1.val.i >= 0x100000)
 	    runtime( "Invalid MPLS label" );
 
+	  struct eattr *nh_ea = ea_find(*fs->eattrs, &ea_gen_nexthop);
+	  if (!nh_ea)
+	    runtime( "No nexthop to add a MPLS label to" );
+
+	  nha.nh = ((struct nexthop_adata *) nh_ea->u.ptr)->nh;
+	  
 	  if (v1.val.i != MPLS_NULL)
 	  {
-	    rta->nh.label[0] = v1.val.i;
-	    rta->nh.labels = 1;
+	    nha.nh.label[0] = v1.val.i;
+	    nha.nh.labels = 1;
+	    nha.ad.length = sizeof nha - sizeof (struct adata);
 	  }
 	  else
-	    rta->nh.labels = 0;
+	    nha.nh.labels = 0;
 	}
 	break;
 
@@ -630,14 +669,32 @@
 	  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);
+
 	  /* Set weight on all next hops */
-	  for (struct nexthop *nh = &rta->nh; nh; nh = nh->next)
+	  NEXTHOP_WALK(nh, nhax)
 	    nh->weight = i - 1;
+
+	  a = ea_set_attr(fs->eattrs,
+	      EA_LITERAL_DIRECT_ADATA(&ea_gen_nexthop, 0, &nhax->ad));
         }
 	break;
 
       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)));
+
+	a->originated = 1;
+	a->fresh = 1;
       }
     }
   }
diff --git a/lib/attrs.h b/lib/attrs.h
index d2638f3f..79b7b14a 100644
--- a/lib/attrs.h
+++ b/lib/attrs.h
@@ -37,7 +37,9 @@ lp_store_adata(struct linpool *pool, const void *buf, uint len)
   return ad;
 }
 
+#define tmp_alloc_adata(len)	  lp_alloc_adata(tmp_linpool, len)
 #define tmp_store_adata(buf, len) lp_store_adata(tmp_linpool, buf, len)
+#define tmp_copy_adata(ad)	  tmp_store_adata((ad)->data, (ad)->length)
 
 static inline int adata_same(const struct adata *a, const struct adata *b)
 { return (a->length == b->length && !memcmp(a->data, b->data, a->length)); }
diff --git a/lib/route.h b/lib/route.h
index 5423ada3..29a78e90 100644
--- a/lib/route.h
+++ b/lib/route.h
@@ -67,13 +67,18 @@ void rt_prune_sources(void);
 struct nexthop {
   ip_addr gw;				/* Next hop */
   struct iface *iface;			/* Outgoing interface */
-  struct nexthop *next;
   byte flags;
   byte weight;
   byte labels;				/* Number of all labels */
   u32 label[0];
 };
 
+/* For packing one into eattrs */
+struct nexthop_adata {
+  struct adata ad;
+  struct nexthop nh;
+};
+
 #define RNF_ONLINK		0x1	/* Gateway is onlink regardless of IP ranges */
 
 
@@ -85,7 +90,6 @@ typedef struct rta {
   struct hostentry *hostentry;		/* Hostentry for recursive next-hops */
   u16 cached:1;				/* Are attributes cached? */
   u16 dest:4;				/* Route destination type (RTD_...) */
-  struct nexthop nh;			/* Next hop */
 } rta;
 
 #define RTS_STATIC 1			/* Normal static route */
@@ -286,9 +290,22 @@ ea_set_attr_u32(ea_list **to, const struct ea_class *def, uint flags, u64 data)
 { ea_set_attr(to, EA_LITERAL_EMBEDDED(def, flags, data)); }
 
 static inline void
-ea_set_attr_data(ea_list **to, const struct ea_class *def, uint flags, void *data, uint len)
+ea_set_attr_data(ea_list **to, const struct ea_class *def, uint flags, const void *data, uint len)
 { ea_set_attr(to, EA_LITERAL_STORE_ADATA(def, flags, data, len)); }
 
+static inline void
+ea_copy_attr(ea_list **to, ea_list *from, const struct ea_class *def)
+{
+  eattr *e = ea_find_by_class(from, def);
+  if (e)
+    if (e->type & EAF_EMBEDDED)
+      ea_set_attr_u32(to, def, e->flags, e->u.data);
+    else
+      ea_set_attr_data(to, def, e->flags, e->u.ptr->data, e->u.ptr->length);
+  else
+    ea_unset_attr(to, 0, def);
+}
+
 /*
  *	Common route attributes
  */
@@ -317,25 +334,39 @@ static inline u32 rt_get_source_attr(rte *rt)
  * to add additional labels to the resolved nexthop */
 extern struct ea_class ea_mpls_labels;
 
+/* Next hop: For now, stored as adata */
+extern struct ea_class ea_gen_nexthop;
+
 /* Next hop structures */
 
-#define NEXTHOP_MAX_SIZE (sizeof(struct nexthop) + sizeof(u32)*MPLS_MAX_LABEL_STACK)
+#define NEXTHOP_ALIGNMENT	(_Alignof(struct nexthop))
+#define NEXTHOP_MAX_SIZE	(sizeof(struct nexthop) + sizeof(u32)*MPLS_MAX_LABEL_STACK)
+#define NEXTHOP_SIZE(_nh)	NEXTHOP_SIZE_CNT(((_nh)->labels))
+#define NEXTHOP_SIZE_CNT(cnt)	BIRD_ALIGN((sizeof(struct nexthop) + sizeof(u32) * (cnt)), NEXTHOP_ALIGNMENT)
+#define nexthop_size(nh)	NEXTHOP_SIZE((nh))
+
+#define NEXTHOP_NEXT(_nh)	((void *) (_nh) + NEXTHOP_SIZE(_nh))
+#define NEXTHOP_END(_nhad)	((_nhad)->ad.data + (_nhad)->ad.length)
+#define NEXTHOP_VALID(_nh, _nhad) ((void *) (_nh) < (void *) NEXTHOP_END(_nhad))
+#define NEXTHOP_ONE(_nhad)	(NEXTHOP_NEXT(&(_nhad)->nh) == NEXTHOP_END(_nhad))
+
+#define NEXTHOP_WALK(_iter, _nhad) for ( \
+    struct nexthop *_iter = &(_nhad)->nh; \
+    (void *) _iter < (void *) NEXTHOP_END(_nhad); \
+    _iter = NEXTHOP_NEXT(_iter))
+
+
+static inline int nexthop_same(struct nexthop_adata *x, struct nexthop_adata *y)
+{ return adata_same(&x->ad, &y->ad); }
+struct nexthop_adata *nexthop_merge(struct nexthop_adata *x, struct nexthop_adata *y, int max, linpool *lp);
+struct nexthop_adata *nexthop_sort(struct nexthop_adata *x, linpool *lp);
+int nexthop_is_sorted(struct nexthop_adata *x);
+
 
-static inline size_t nexthop_size(const struct nexthop *nh)
-{ return sizeof(struct nexthop) + sizeof(u32)*nh->labels; }
-int nexthop__same(struct nexthop *x, struct nexthop *y); /* Compare multipath nexthops */
-static inline int nexthop_same(struct nexthop *x, struct nexthop *y)
-{ return (x == y) || nexthop__same(x, y); }
-struct nexthop *nexthop_merge(struct nexthop *x, struct nexthop *y, int rx, int ry, int max, linpool *lp);
-struct nexthop *nexthop_sort(struct nexthop *x);
-static inline void nexthop_link(struct rta *a, struct nexthop *from)
-{ memcpy(&a->nh, from, nexthop_size(from)); }
-void nexthop_insert(struct nexthop **n, struct nexthop *y);
-int nexthop_is_sorted(struct nexthop *x);
 
 void rta_init(void);
-static inline size_t rta_size(const rta *a) { return sizeof(rta) + sizeof(u32)*a->nh.labels; }
-#define RTA_MAX_SIZE (sizeof(rta) + sizeof(u32)*MPLS_MAX_LABEL_STACK)
+#define rta_size(...) (sizeof(rta))
+#define RTA_MAX_SIZE (sizeof(rta))
 rta *rta_lookup(rta *);			/* Get rta equivalent to this one, uc++ */
 static inline int rta_is_cached(rta *r) { return r->cached; }
 static inline rta *rta_clone(rta *r) { r->uc++; return r; }
diff --git a/lib/type.h b/lib/type.h
index abce1a1f..6da86c77 100644
--- a/lib/type.h
+++ b/lib/type.h
@@ -52,6 +52,7 @@ enum btype {
 /* Something but inaccessible. */
   T_OPAQUE = 0x02,		/* Opaque byte string (not filterable) */
   T_IFACE = 0x0c,		/* Pointer to an interface (inside adata) */
+  T_NEXTHOP_LIST = 0x2c,	/* The whole nexthop block */
 
 /* Types shared with eattrs */
   T_INT = 0x01,			/* 32-bit unsigned integer number */
diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index dc4fe785..bd7ca425 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -57,6 +57,7 @@
 #include "lib/string.h"
 
 #include <stddef.h>
+#include <stdlib.h>
 
 const adata null_adata;		/* adata of length 0 */
 
@@ -108,6 +109,11 @@ struct ea_class ea_gen_source = {
   .format = ea_gen_source_format,
 };
 
+struct ea_class ea_gen_nexthop = {
+  .name = "nexthop",
+  .type = T_NEXTHOP_LIST,
+};
+
 struct ea_class ea_mpls_labels = {
   .name = "mpls_labels",
   .type = T_CLIST,
@@ -124,8 +130,7 @@ const char * rta_dest_names[RTD_MAX] = {
 
 pool *rta_pool;
 
-static slab *rta_slab_[4];
-static slab *nexthop_slab_[4];
+static slab *rta_slab;
 static slab *rte_src_slab;
 
 static struct idm src_ids;
@@ -204,50 +209,10 @@ rt_prune_sources(void)
  *	Multipath Next Hop
  */
 
-static inline u32
-nexthop_hash(struct nexthop *x)
-{
-  u32 h = 0;
-  for (; x; x = x->next)
-  {
-    h ^= ipa_hash(x->gw) ^ (h << 5) ^ (h >> 9);
-
-    for (int i = 0; i < x->labels; i++)
-      h ^= x->label[i] ^ (h << 6) ^ (h >> 7);
-  }
-
-  return h;
-}
-
-int
-nexthop__same(struct nexthop *x, struct nexthop *y)
-{
-  for (; x && y; x = x->next, y = y->next)
-  {
-    if (!ipa_equal(x->gw, y->gw) || (x->iface != y->iface) ||
-	(x->flags != y->flags) || (x->weight != y->weight) ||
-	(x->labels != y->labels))
-      return 0;
-
-    for (int i = 0; i < x->labels; i++)
-      if (x->label[i] != y->label[i])
-	return 0;
-  }
-
-  return x == y;
-}
-
 static int
 nexthop_compare_node(const struct nexthop *x, const struct nexthop *y)
 {
   int r;
-
-  if (!x)
-    return 1;
-
-  if (!y)
-    return -1;
-
   /* Should we also compare flags ? */
 
   r = ((int) y->weight) - ((int) x->weight);
@@ -272,23 +237,16 @@ nexthop_compare_node(const struct nexthop *x, const struct nexthop *y)
   return ((int) x->iface->index) - ((int) y->iface->index);
 }
 
-static inline struct nexthop *
-nexthop_copy_node(const struct nexthop *src, linpool *lp)
+static int
+nexthop_compare_qsort(const void *x, const void *y)
 {
-  struct nexthop *n = lp_alloc(lp, nexthop_size(src));
-
-  memcpy(n, src, nexthop_size(src));
-  n->next = NULL;
-
-  return n;
+  return nexthop_compare_node( *(const struct nexthop **) x, *(const struct nexthop **) y );
 }
 
 /**
  * nexthop_merge - merge nexthop lists
  * @x: list 1
  * @y: list 2
- * @rx: reusability of list @x
- * @ry: reusability of list @y
  * @max: max number of nexthops
  * @lp: linpool for allocating nexthops
  *
@@ -305,134 +263,111 @@ nexthop_copy_node(const struct nexthop *src, linpool *lp)
  * resulting list is no longer needed. When reusability is not set, the
  * corresponding lists are not modified nor linked from the resulting list.
  */
-struct nexthop *
-nexthop_merge(struct nexthop *x, struct nexthop *y, int rx, int ry, int max, linpool *lp)
+struct nexthop_adata *
+nexthop_merge(struct nexthop_adata *xin, struct nexthop_adata *yin, int max, linpool *lp)
 {
-  struct nexthop *root = NULL;
-  struct nexthop **n = &root;
+  uint outlen = ADATA_SIZE(xin->ad.length) + ADATA_SIZE(yin->ad.length);
+  struct nexthop_adata *out = lp_alloc(lp, outlen);
+  out->ad.length = outlen - sizeof (struct adata);
 
-  while ((x || y) && max--)
+  struct nexthop *x = &xin->nh, *y = &yin->nh, *cur = &out->nh;
+  int xvalid, yvalid;
+
+  while (max--)
   {
-    int cmp = nexthop_compare_node(x, y);
+    xvalid = NEXTHOP_VALID(x, xin);
+    yvalid = NEXTHOP_VALID(y, yin);
 
-    if (cmp < 0)
-    {
-      ASSUME(x);
-      *n = rx ? x : nexthop_copy_node(x, lp);
-      x = x->next;
-    }
-    else if (cmp > 0)
-    {
-      ASSUME(y);
-      *n = ry ? y : nexthop_copy_node(y, lp);
-      y = y->next;
-    }
-    else
-    {
-      ASSUME(x && y);
-      *n = rx ? x : (ry ? y : nexthop_copy_node(x, lp));
-      x = x->next;
-      y = y->next;
-    }
-    n = &((*n)->next);
-  }
-  *n = NULL;
-
-  return root;
-}
-
-void
-nexthop_insert(struct nexthop **n, struct nexthop *x)
-{
-  for (; *n; n = &((*n)->next))
-  {
-    int cmp = nexthop_compare_node(*n, x);
-
-    if (cmp < 0)
-      continue;
-    else if (cmp > 0)
+    if (!xvalid && !yvalid)
       break;
+
+    ASSUME(NEXTHOP_VALID(cur, out));
+
+    int cmp = !xvalid ? 1 : !yvalid ? -1 : nexthop_compare_node(x, y);
+
+    if (cmp < 0)
+    {
+      ASSUME(NEXTHOP_VALID(x, xin));
+      memcpy(cur, x, nexthop_size(x));
+      x = NEXTHOP_NEXT(x);
+    }
+    else if (cmp > 0)
+    {
+      ASSUME(NEXTHOP_VALID(y, yin));
+      memcpy(cur, y, nexthop_size(y));
+      y = NEXTHOP_NEXT(y);
+    }
     else
-      return;
+    {
+      ASSUME(NEXTHOP_VALID(x, xin));
+      memcpy(cur, x, nexthop_size(x));
+      x = NEXTHOP_NEXT(x);
+
+      ASSUME(NEXTHOP_VALID(y, yin));
+      y = NEXTHOP_NEXT(y);
+    }
+    cur = NEXTHOP_NEXT(cur);
   }
 
-  x->next = *n;
-  *n = x;
+  out->ad.length = (void *) cur - (void *) out->ad.data;
+
+  return out;
 }
 
-struct nexthop *
-nexthop_sort(struct nexthop *x)
+struct nexthop_adata *
+nexthop_sort(struct nexthop_adata *nhad, linpool *lp)
 {
-  struct nexthop *s = NULL;
+  /* Count the nexthops */
+  uint cnt = 0;
+  NEXTHOP_WALK(nh, nhad)
+    cnt++;
 
-  /* Simple insert-sort */
-  while (x)
+  if (cnt <= 1)
+    return nhad;
+
+  /* Get pointers to them */
+  struct nexthop **sptr = tmp_alloc(cnt * sizeof(struct nexthop *));
+
+  uint i = 0;
+  NEXTHOP_WALK(nh, nhad)
+    sptr[i++] = nh;
+
+  /* Sort the pointers */
+  qsort(sptr, cnt, sizeof(struct nexthop *), nexthop_compare_qsort);
+
+  /* Allocate the output */
+  struct nexthop_adata *out = (struct nexthop_adata *) lp_alloc_adata(lp, nhad->ad.length);
+  struct nexthop *dest = &out->nh;
+
+  /* Deduplicate nexthops while storing them */
+  for (uint i = 0; i < cnt; i++)
   {
-    struct nexthop *n = x;
-    x = n->next;
-    n->next = NULL;
+    if (i && !nexthop_compare_node(sptr[i], sptr[i-1]))
+      continue;
 
-    nexthop_insert(&s, n);
+    memcpy(dest, sptr[i], NEXTHOP_SIZE(sptr[i]));
+    dest = NEXTHOP_NEXT(dest);
   }
 
-  return s;
+  out->ad.length = (void *) dest - (void *) out->ad.data;
+  return out;
 }
 
 int
-nexthop_is_sorted(struct nexthop *x)
+nexthop_is_sorted(struct nexthop_adata *nhad)
 {
-  for (; x && x->next; x = x->next)
-    if (nexthop_compare_node(x, x->next) >= 0)
+  struct nexthop *prev = NULL;
+  NEXTHOP_WALK(nh, nhad)
+  {
+    if (prev && (nexthop_compare_node(prev, nh) >= 0))
       return 0;
 
+    prev = nh;
+  }
+
   return 1;
 }
 
-static inline slab *
-nexthop_slab(struct nexthop *nh)
-{
-  return nexthop_slab_[MIN(nh->labels, 3)];
-}
-
-static struct nexthop *
-nexthop_copy(struct nexthop *o)
-{
-  struct nexthop *first = NULL;
-  struct nexthop **last = &first;
-
-  for (; o; o = o->next)
-    {
-      struct nexthop *n = sl_allocz(nexthop_slab(o));
-      n->gw = o->gw;
-      n->iface = o->iface;
-      n->next = NULL;
-      n->flags = o->flags;
-      n->weight = o->weight;
-      n->labels = o->labels;
-      for (int i=0; i<o->labels; i++)
-	n->label[i] = o->label[i];
-
-      *last = n;
-      last = &(n->next);
-    }
-
-  return first;
-}
-
-static void
-nexthop_free(struct nexthop *o)
-{
-  struct nexthop *n;
-
-  while (o)
-    {
-      n = o->next;
-      sl_free(o);
-      o = n;
-    }
-}
-
-
 /*
  *	Extended Attributes
  */
@@ -1122,6 +1057,23 @@ ea_show(struct cli *c, const eattr *e)
   cli_printf(c, -1012, "\t%s", buf);
 }
 
+static void
+nexthop_dump(const struct adata *ad)
+{
+  struct nexthop_adata *nhad = (struct nexthop_adata *) ad;
+
+  debug(":");
+
+  NEXTHOP_WALK(nh, nhad)
+    {
+      if (ipa_nonzero(nh->gw)) debug(" ->%I", nh->gw);
+      if (nh->labels) debug(" L %d", nh->label[0]);
+      for (int i=1; i<nh->labels; i++)
+	debug("/%d", nh->label[i]);
+      debug(" [%s]", nh->iface ? nh->iface->name : "???");
+    }
+}
+
 /**
  * ea_dump - dump an extended attribute
  * @e: attribute to be dumped
@@ -1157,6 +1109,8 @@ ea_dump(ea_list *e)
 	    debug("o");
 	  if (a->type & EAF_EMBEDDED)
 	    debug(":%08x", a->u.data);
+	  else if (a->id == ea_gen_nexthop.id)
+	    nexthop_dump(a->u.ptr);
 	  else
 	    {
 	      int j, len = a->u.ptr->length;
@@ -1258,7 +1212,7 @@ rta_hash(rta *a)
   BMIX(dest);
 #undef MIX
 
-  return mem_hash_value(&h) ^ nexthop_hash(&(a->nh)) ^ ea_hash(a->eattrs);
+  return mem_hash_value(&h) ^ ea_hash(a->eattrs);
 }
 
 static inline int
@@ -1266,24 +1220,16 @@ rta_same(rta *x, rta *y)
 {
   return (x->dest == y->dest &&
 	  x->hostentry == y->hostentry &&
-	  nexthop_same(&(x->nh), &(y->nh)) &&
 	  ea_same(x->eattrs, y->eattrs));
 }
 
-static inline slab *
-rta_slab(rta *a)
-{
-  return rta_slab_[a->nh.labels > 2 ? 3 : a->nh.labels];
-}
-
 static rta *
 rta_copy(rta *o)
 {
-  rta *r = sl_alloc(rta_slab(o));
+  rta *r = sl_alloc(rta_slab);
 
   memcpy(r, o, rta_size(o));
   r->uc = 1;
-  r->nh.next = nexthop_copy(o->nh.next);
   if (!r->eattrs)
     return r;
 
@@ -1375,8 +1321,6 @@ rta__free(rta *a)
   if (a->next)
     a->next->pprev = a->pprev;
   rt_unlock_hostentry(a->hostentry);
-  if (a->nh.next)
-    nexthop_free(a->nh.next);
   ea_free(a->eattrs);
   a->cached = 0;
   sl_free(a);
@@ -1387,12 +1331,6 @@ rta_do_cow(rta *o, linpool *lp)
 {
   rta *r = lp_alloc(lp, rta_size(o));
   memcpy(r, o, rta_size(o));
-  for (struct nexthop **nhn = &(r->nh.next), *nho = o->nh.next; nho; nho = nho->next)
-    {
-      *nhn = lp_alloc(lp, nexthop_size(nho));
-      memcpy(*nhn, nho, nexthop_size(nho));
-      nhn = &((*nhn)->next);
-    }
   r->cached = 0;
   r->uc = 0;
   return r;
@@ -1413,15 +1351,6 @@ rta_dump(rta *a)
 	a->uc, rtd[a->dest], a->hash_key);
   if (!a->cached)
     debug(" !CACHED");
-  if (a->dest == RTD_UNICAST)
-    for (struct nexthop *nh = &(a->nh); nh; nh = nh->next)
-      {
-	if (ipa_nonzero(nh->gw)) debug(" ->%I", nh->gw);
-	if (nh->labels) debug(" L %d", nh->label[0]);
-	for (int i=1; i<nh->labels; i++)
-	  debug("/%d", nh->label[i]);
-	debug(" [%s]", nh->iface ? nh->iface->name : "???");
-      }
   if (a->eattrs)
     {
       debug(" EA: ");
@@ -1471,15 +1400,7 @@ rta_init(void)
 {
   rta_pool = rp_new(&root_pool, "Attributes");
 
-  rta_slab_[0] = sl_new(rta_pool, sizeof(rta));
-  rta_slab_[1] = sl_new(rta_pool, sizeof(rta) + sizeof(u32));
-  rta_slab_[2] = sl_new(rta_pool, sizeof(rta) + sizeof(u32)*2);
-  rta_slab_[3] = sl_new(rta_pool, sizeof(rta) + sizeof(u32)*MPLS_MAX_LABEL_STACK);
-
-  nexthop_slab_[0] = sl_new(rta_pool, sizeof(struct nexthop));
-  nexthop_slab_[1] = sl_new(rta_pool, sizeof(struct nexthop) + sizeof(u32));
-  nexthop_slab_[2] = sl_new(rta_pool, sizeof(struct nexthop) + sizeof(u32)*2);
-  nexthop_slab_[3] = sl_new(rta_pool, sizeof(struct nexthop) + sizeof(u32)*MPLS_MAX_LABEL_STACK);
+  rta_slab = sl_new(rta_pool, sizeof(rta));
 
   rta_alloc_hash();
   rte_src_init();
@@ -1489,6 +1410,7 @@ rta_init(void)
   ea_register_init(&ea_gen_igp_metric);
   ea_register_init(&ea_gen_from);
   ea_register_init(&ea_gen_source);
+  ea_register_init(&ea_gen_nexthop);
 
   ea_register_init(&ea_mpls_labels);
 }
diff --git a/nest/rt-dev.c b/nest/rt-dev.c
index af6506f6..9953e270 100644
--- a/nest/rt-dev.c
+++ b/nest/rt-dev.c
@@ -84,11 +84,16 @@ dev_ifa_notify(struct proto *P, uint flags, struct ifa *ad)
 
       rta a0 = {
 	.dest = RTD_UNICAST,
-	.nh.iface = ad->iface,
+      };
+
+      struct nexthop_adata nhad = {
+	.nh = { .iface = ad->iface, },
+	.ad = { .length = (void *) NEXTHOP_NEXT(&nhad.nh) - (void *) nhad.ad.data, },
       };
 
       ea_set_attr_u32(&a0.eattrs, &ea_gen_preference, 0, c->preference);
       ea_set_attr_u32(&a0.eattrs, &ea_gen_source, 0, RTS_DEVICE);
+      ea_set_attr_data(&a0.eattrs, &ea_gen_nexthop, 0, nhad.ad.data, nhad.ad.length);
 
       a = rta_lookup(&a0);
       e = rte_get_temp(a, src);
diff --git a/nest/rt-show.c b/nest/rt-show.c
index be4c0186..32f7aa2d 100644
--- a/nest/rt-show.c
+++ b/nest/rt-show.c
@@ -45,11 +45,12 @@ rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary
   rta *a = e->attrs;
   int sync_error = d->kernel ? krt_get_sync_error(d->kernel, e) : 0;
   void (*get_route_info)(struct rte *, byte *buf);
-  struct nexthop *nh;
+  eattr *nhea = ea_find(a->eattrs, &ea_gen_nexthop);
+  struct nexthop_adata *nhad = nhea ? (struct nexthop_adata *) nhea->u.ptr : NULL;
 
   tm_format_time(tm, &config->tf_route, e->lastmod);
   ip_addr a_from = ea_get_ip(a->eattrs, &ea_gen_from, IPA_NONE);
-  if (ipa_nonzero(a_from) && !ipa_equal(a_from, a->nh.gw))
+  if (ipa_nonzero(a_from) && (!nhad || !ipa_equal(a_from, nhad->nh.gw)))
     bsprintf(from, " from %I", a_from);
   else
     from[0] = 0;
@@ -71,7 +72,7 @@ rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary
 	     e->src->proto->name, tm, from, primary ? (sync_error ? " !" : " *") : "", info);
 
   if (a->dest == RTD_UNICAST)
-    for (nh = &(a->nh); nh; nh = nh->next)
+    NEXTHOP_WALK(nh, nhad)
     {
       char mpls[MPLS_MAX_LABEL_STACK*12 + 5], *lsp = mpls;
       char *onlink = (nh->flags & RNF_ONLINK) ? " onlink" : "";
@@ -85,7 +86,7 @@ rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary
 	}
       *lsp = '\0';
 
-      if (a->nh.next)
+      if (!NEXTHOP_ONE(nhad))
 	bsprintf(weight, " weight %d", nh->weight + 1);
 
       if (ipa_nonzero(nh->gw))
diff --git a/nest/rt-table.c b/nest/rt-table.c
index 37f17bbc..6f948ada 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -940,18 +940,11 @@ rt_notify_accepted(struct channel *c, net *net, rte *new_changed, rte *old_chang
     rte_free(new_free);
 }
 
-
-static struct nexthop *
-nexthop_merge_rta(struct nexthop *nhs, rta *a, linpool *pool, int max)
-{
-  return nexthop_merge(nhs, &(a->nh), 1, 0, max, pool);
-}
-
 rte *
 rt_export_merged(struct channel *c, net *net, rte **rt_free, linpool *pool, int silent)
 {
   // struct proto *p = c->proto;
-  struct nexthop *nhs = NULL;
+  struct nexthop_adata *nhs = NULL;
   rte *best0, *best, *rt0, *rt, *tmp;
 
   best0 = net->routes;
@@ -976,21 +969,31 @@ rt_export_merged(struct channel *c, net *net, rte **rt_free, linpool *pool, int
       continue;
 
     if (rte_is_reachable(rt))
-      nhs = nexthop_merge_rta(nhs, rt->attrs, pool, c->merge_limit);
+    {
+      eattr *nhea = ea_find(rt->attrs->eattrs, &ea_gen_nexthop);
+      ASSERT_DIE(nhea);
+
+      if (nhs)
+	nhs = nexthop_merge(nhs, (struct nexthop_adata *) nhea->u.ptr, c->merge_limit, pool);
+      else
+	nhs = (struct nexthop_adata *) nhea->u.ptr;
+    }
 
     if (tmp)
       rte_free(tmp);
   }
 
+
   if (nhs)
   {
-    nhs = nexthop_merge_rta(nhs, best->attrs, pool, c->merge_limit);
+    eattr *nhea = ea_find(best->attrs->eattrs, &ea_gen_nexthop);
+    ASSERT_DIE(nhea);
 
-    if (nhs->next)
-    {
-      best = rte_cow_rta(best, pool);
-      nexthop_link(best->attrs, nhs);
-    }
+    nhs = nexthop_merge(nhs, (struct nexthop_adata *) nhea->u.ptr, c->merge_limit, pool);
+
+    best = rte_cow_rta(best, pool);
+    ea_set_attr(&best->attrs->eattrs,
+	EA_LITERAL_DIRECT_ADATA(&ea_gen_nexthop, 0, &nhs->ad));
   }
 
   if (best != best0)
@@ -1184,7 +1187,16 @@ rte_validate(rte *e)
     return 0;
   }
 
-  if ((e->attrs->dest == RTD_UNICAST) && !nexthop_is_sorted(&(e->attrs->nh)))
+  eattr *nhea = ea_find(e->attrs->eattrs, &ea_gen_nexthop);
+  if ((!nhea) != (e->attrs->dest != RTD_UNICAST))
+  {
+    log(L_WARN "Ignoring route %N with destination %d and %snexthop received via %s",
+	n->n.addr, e->attrs->dest, (nhea ? "" : "no "), e->sender->proto->name);
+    return 0;
+  }
+
+  if ((e->attrs->dest == RTD_UNICAST) &&
+      !nexthop_is_sorted((struct nexthop_adata *) nhea->u.ptr))
   {
     log(L_WARN "Ignoring unsorted multipath route %N received via %s",
 	n->n.addr, e->sender->proto->name);
@@ -2395,8 +2407,7 @@ rta_apply_hostentry(rta *a, struct hostentry *he)
   if (a->dest != RTD_UNICAST)
   {
     /* No nexthop */
-no_nexthop:
-    a->nh = (struct nexthop) {};
+    ea_unset_attr(&a->eattrs, 0, &ea_gen_nexthop);
     return;
   }
 
@@ -2404,74 +2415,71 @@ no_nexthop:
 
   if (!mls_ea && he->nexthop_linkable)
   { /* Just link the nexthop chain, no label append happens. */
-    memcpy(&(a->nh), &(he->src->nh), nexthop_size(&(he->src->nh)));
+    ea_copy_attr(&a->eattrs, he->src->eattrs, &ea_gen_nexthop);
     return;
   }
 
-  struct nexthop *nhp = NULL, *nhr = NULL;
-  int skip_nexthop = 0;
-
   const struct adata *mls = mls_ea ? mls_ea->u.ptr : NULL;
   uint mls_cnt = mls ? mls->length / sizeof(u32) : 0;
 
-  for (struct nexthop *nh = &(he->src->nh); nh; nh = nh->next)
+  eattr *he_nh_ea = ea_find(he->src->eattrs, &ea_gen_nexthop);
+  struct nexthop_adata *nhad = (struct nexthop_adata *) he_nh_ea->u.ptr;
+
+  uint total_size = OFFSETOF(struct nexthop_adata, nh);
+
+  NEXTHOP_WALK(nh, nhad)
   {
-    if (skip_nexthop)
-      skip_nexthop--;
-    else
+    if (nh->labels + mls_cnt > MPLS_MAX_LABEL_STACK)
     {
-      nhr = nhp;
-      nhp = (nhp ? (nhp->next = lp_alloc(rte_update_pool, NEXTHOP_MAX_SIZE)) : &(a->nh));
+      log(L_WARN "Sum of label stack sizes %d + %d = %d exceedes allowed maximum (%d)",
+	    nh->labels, mls_cnt, nh->labels + mls_cnt, MPLS_MAX_LABEL_STACK);
+      continue;
     }
 
-    memset(nhp, 0, NEXTHOP_MAX_SIZE);
-    nhp->iface = nh->iface;
-    nhp->weight = nh->weight;
+    total_size += NEXTHOP_SIZE_CNT(nh->labels + mls_cnt);
+  }
 
-    if (mls)
+  if (total_size == OFFSETOF(struct nexthop_adata, nh))
+  {
+    a->dest = RTD_UNREACHABLE;
+    log(L_WARN "No valid nexthop remaining, setting route unreachable");
+
+    ea_unset_attr(&a->eattrs, 0, &ea_gen_nexthop);
+    return;
+  }
+
+  struct nexthop_adata *new = (struct nexthop_adata *) tmp_alloc_adata(total_size);
+  struct nexthop *dest = &new->nh;
+
+  NEXTHOP_WALK(nh, nhad)
+  {
+    if (nh->labels + mls_cnt > MPLS_MAX_LABEL_STACK)
+      continue;
+
+    memcpy(dest, nh, NEXTHOP_SIZE(nh));
+    if (mls_cnt)
     {
-      nhp->labels = nh->labels + mls_cnt;
-      if (nhp->labels <= MPLS_MAX_LABEL_STACK)
-      {
-	memcpy(nhp->label, nh->label, nh->labels * sizeof(u32)); /* First the hostentry labels */
-	memcpy(&(nhp->label[nh->labels]), mls->data, mls->length); /* Then the bottom labels */
-      }
-      else
-      {
-	log(L_WARN "Sum of label stack sizes %d + %d = %d exceedes allowed maximum (%d)",
-	    nh->labels, mls_cnt, nhp->labels, MPLS_MAX_LABEL_STACK);
-	skip_nexthop++;
-	continue;
-      }
-    }
-    else if (nh->labels)
-    {
-      nhp->labels = nh->labels;
-      memcpy(nhp->label, nh->label, nh->labels * sizeof(u32));
+      memcpy(&(dest->label[dest->labels]), mls->data, mls->length);
+      dest->labels += mls_cnt;
     }
 
     if (ipa_nonzero(nh->gw))
-    {
-      nhp->gw = nh->gw;			/* Router nexthop */
-      nhp->flags |= (nh->flags & RNF_ONLINK);
-    }
+      /* Router nexthop */
+      dest->flags = (dest->flags & RNF_ONLINK);
     else if (!(nh->iface->flags & IF_MULTIACCESS) || (nh->iface->flags & IF_LOOPBACK))
-      nhp->gw = IPA_NONE;		/* PtP link - no need for nexthop */
+      dest->gw = IPA_NONE;		/* PtP link - no need for nexthop */
     else if (ipa_nonzero(he->link))
-      nhp->gw = he->link;		/* Device nexthop with link-local address known */
+      dest->gw = he->link;		/* Device nexthop with link-local address known */
     else
-      nhp->gw = he->addr;		/* Device nexthop with link-local address unknown */
+      dest->gw = he->addr;		/* Device nexthop with link-local address unknown */
+
+    dest = NEXTHOP_NEXT(dest);
   }
 
-  if (skip_nexthop)
-    if (nhr)
-      nhr->next = NULL;
-    else
-    {
-      a->dest = RTD_UNREACHABLE;
-      log(L_WARN "No valid nexthop remaining, setting route unreachable");
-      goto no_nexthop;
-    }
+  /* Fix final length */
+  new->ad.length = (void *) dest - (void *) new->ad.data;
+  ea_set_attr(&a->eattrs, EA_LITERAL_DIRECT_ADATA(
+	&ea_gen_nexthop, 0, &new->ad));
 }
 
 static inline int
@@ -2485,9 +2493,14 @@ rta_next_hop_outdated(rta *a)
   if (!he->src)
     return a->dest != RTD_UNREACHABLE;
 
+  eattr *he_nh_ea = ea_find(he->src->eattrs, &ea_gen_nexthop);
+  eattr *a_nh_ea = ea_find(a->eattrs, &ea_gen_nexthop);
+
   return (a->dest != he->dest) ||
     (ea_get_int(a->eattrs, &ea_gen_igp_metric, IGP_METRIC_UNKNOWN) != he->igp_metric) ||
-    (!he->nexthop_linkable) || !nexthop_same(&(a->nh), &(he->src->nh));
+    (!he->nexthop_linkable) ||
+    (!he_nh_ea != !a_nh_ea) ||
+    (he_nh_ea && a_nh_ea && !adata_same(he_nh_ea->u.ptr, a_nh_ea->u.ptr));
 }
 
 static inline rte *
@@ -3507,7 +3520,14 @@ rt_update_hostentry(rtable *tab, struct hostentry *he)
 
       if (a->dest == RTD_UNICAST)
 	{
-	  for (struct nexthop *nh = &(a->nh); nh; nh = nh->next)
+	  eattr *ea = ea_find(a->eattrs, &ea_gen_nexthop);
+	  if (!ea)
+	    {
+	      log(L_WARN "No nexthop in unicast route");
+	      goto done;
+	    }
+	    
+	  NEXTHOP_WALK(nh, (struct nexthop_adata *) ea->u.ptr)
 	    if (ipa_zero(nh->gw))
 	      {
 		if (if_local_addr(he->addr, nh->iface))
diff --git a/proto/babel/babel.c b/proto/babel/babel.c
index a7dcee09..9a43f484 100644
--- a/proto/babel/babel.c
+++ b/proto/babel/babel.c
@@ -643,26 +643,14 @@ babel_announce_rte(struct babel_proto *p, struct babel_entry *e)
 
   if (r)
   {
-    struct {
-      ea_list l;
-      eattr a[6];
-    } eattrs = {
-      .l.count = ARRAY_SIZE(eattrs.a),
-      .a = {
-	EA_LITERAL_EMBEDDED(&ea_gen_preference, 0, c->preference),
-	EA_LITERAL_STORE_ADATA(&ea_gen_from, 0, &r->neigh->addr, sizeof(r->neigh->addr)),
-	EA_LITERAL_EMBEDDED(&ea_gen_source, 0, RTS_BABEL),
-	EA_LITERAL_EMBEDDED(&ea_babel_metric, 0, r->metric),
-	EA_LITERAL_STORE_ADATA(&ea_babel_router_id, 0, &r->router_id, sizeof(r->router_id)),
-	EA_LITERAL_EMBEDDED(&ea_babel_seqno, 0, r->seqno),
-      }
-    };
-
-    rta a0 = {
-      .dest = RTD_UNICAST,
-      .nh.gw = r->next_hop,
-      .nh.iface = r->neigh->ifa->iface,
-      .eattrs = &eattrs.l,
+    struct nexthop_adata nhad = {
+      .nh = {
+	.gw = r->next_hop,
+	.iface = r->neigh->ifa->iface,
+      },
+      .ad = {
+	.length = sizeof nhad - sizeof nhad.ad,
+      },
     };
 
     /*
@@ -671,7 +659,28 @@ babel_announce_rte(struct babel_proto *p, struct babel_entry *e)
      * have routing work.
      */
     if (!neigh_find(&p->p, r->next_hop, r->neigh->ifa->iface, 0))
-      a0.nh.flags = RNF_ONLINK;
+      nhad.nh.flags = RNF_ONLINK;
+    
+    struct {
+      ea_list l;
+      eattr a[7];
+    } eattrs = {
+      .l.count = ARRAY_SIZE(eattrs.a),
+      .a = {
+	EA_LITERAL_EMBEDDED(&ea_gen_preference, 0, c->preference),
+	EA_LITERAL_STORE_ADATA(&ea_gen_from, 0, &r->neigh->addr, sizeof(r->neigh->addr)),
+	EA_LITERAL_EMBEDDED(&ea_gen_source, 0, RTS_BABEL),
+	EA_LITERAL_STORE_ADATA(&ea_gen_nexthop, 0, nhad.ad.data, nhad.ad.length),
+	EA_LITERAL_EMBEDDED(&ea_babel_metric, 0, r->metric),
+	EA_LITERAL_STORE_ADATA(&ea_babel_router_id, 0, &r->router_id, sizeof(r->router_id)),
+	EA_LITERAL_EMBEDDED(&ea_babel_seqno, 0, r->seqno),
+      }
+    };
+
+    rta a0 = {
+      .dest = RTD_UNICAST,
+      .eattrs = &eattrs.l,
+    };
 
     rta *a = rta_lookup(&a0);
     rte *rte = rte_get_temp(a, p->p.main_source);
diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c
index f8228313..fd0a1be4 100644
--- a/proto/bgp/packets.c
+++ b/proto/bgp/packets.c
@@ -966,10 +966,19 @@ bgp_apply_next_hop(struct bgp_parse_state *s, rta *a, ip_addr gw, ip_addr ll)
     if (nbr->scope == SCOPE_HOST)
       WITHDRAW(BAD_NEXT_HOP " - address %I is local", nbr->addr);
 
-    a->dest = RTD_UNICAST;
-    a->nh.gw = nbr->addr;
-    a->nh.iface = nbr->iface;
     ea_set_attr_u32(&a->eattrs, &ea_gen_igp_metric, 0, c->cf->cost);
+
+    a->dest = RTD_UNICAST;
+    struct nexthop_adata nhad = {
+      .nh = {
+	.gw = nbr->addr,
+	.iface = nbr->iface,
+      },
+      .ad = {
+	.length = sizeof nhad - sizeof nhad.ad,
+      },
+    };
+    ea_set_attr_data(&a->eattrs, &ea_gen_nexthop, 0, nhad.ad.data, nhad.ad.length);
   }
   else /* GW_RECURSIVE */
   {
@@ -998,7 +1007,7 @@ bgp_apply_mpls_labels(struct bgp_parse_state *s, rta *a)
 
     a->dest = RTD_UNREACHABLE;
     a->hostentry = NULL;
-    a->nh = (struct nexthop) { };
+    ea_unset_attr(&a->eattrs, 0, &ea_gen_nexthop);
     return;
   }
 
@@ -1008,8 +1017,16 @@ bgp_apply_mpls_labels(struct bgp_parse_state *s, rta *a)
 
   if (s->channel->cf->gw_mode == GW_DIRECT)
   {
-    a->nh.labels = lnum;
-    memcpy(a->nh.label, labels, 4*lnum);
+    eattr *e = ea_find(a->eattrs, &ea_gen_nexthop);
+    struct {
+      struct nexthop_adata nhad;
+      u32 labels[MPLS_MAX_LABEL_STACK];
+    } nh;
+    
+    memcpy(&nh.nhad, e->u.ptr, sizeof(struct adata) + e->u.ptr->length);
+    nh.nhad.nh.labels = lnum;
+    memcpy(nh.labels, labels, lnum * sizeof(u32));
+    nh.nhad.ad.length = sizeof nh.nhad + lnum * sizeof(u32);
   }
   else /* GW_RECURSIVE */
     rta_apply_hostentry(a, s->hostentry);
@@ -1076,7 +1093,7 @@ bgp_use_next_hop(struct bgp_export_state *s, eattr *a)
   return p->neigh && (p->neigh->iface == ifa);
 }
 
-static inline int
+static inline struct nexthop *
 bgp_use_gateway(struct bgp_export_state *s)
 {
   struct bgp_proto *p = s->proto;
@@ -1085,22 +1102,35 @@ bgp_use_gateway(struct bgp_export_state *s)
 
   /* Handle next hop self option - also applies to gateway */
   if (c->cf->next_hop_self && bgp_match_src(s, c->cf->next_hop_self))
-    return 0;
+    return NULL;
+
+  /* Unreachable */
+  if (ra->dest != RTD_UNICAST)
+    return NULL;
+
+  eattr *nhea = ea_find(ra->eattrs, &ea_gen_nexthop);
+  if (!nhea)
+    return NULL;
 
   /* We need one valid global gateway */
-  if ((ra->dest != RTD_UNICAST) || ra->nh.next || ipa_zero(ra->nh.gw) || ipa_is_link_local(ra->nh.gw))
-    return 0;
+  struct nexthop_adata *nhad = (struct nexthop_adata *) nhea->u.ptr;
+  if (!NEXTHOP_ONE(nhad) || ipa_zero(nhad->nh.gw) ||
+      ipa_is_link_local(nhad->nh.gw))
+    return NULL;
 
   /* Check for non-matching AF */
-  if ((ipa_is_ip4(ra->nh.gw) != bgp_channel_is_ipv4(c)) && !c->ext_next_hop)
-    return 0;
+  if ((ipa_is_ip4(nhad->nh.gw) != bgp_channel_is_ipv4(c)) && !c->ext_next_hop)
+    return NULL;
 
   /* Use it when exported to internal peers */
   if (p->is_interior)
-    return 1;
+    return &nhad->nh;
 
   /* Use it when forwarded to single-hop BGP peer on on the same iface */
-  return p->neigh && (p->neigh->iface == ra->nh.iface);
+  if (p->neigh && (p->neigh->iface == nhad->nh.iface))
+    return &nhad->nh;
+
+  return NULL;
 }
 
 static void
@@ -1108,17 +1138,17 @@ bgp_update_next_hop_ip(struct bgp_export_state *s, eattr *a, ea_list **to)
 {
   if (!a || !bgp_use_next_hop(s, a))
   {
-    if (bgp_use_gateway(s))
+    struct nexthop *nhloc;
+    if (nhloc = bgp_use_gateway(s))
     {
-      rta *ra = s->route->attrs;
-      ip_addr nh[1] = { ra->nh.gw };
+      ip_addr nh[1] = { nhloc->gw };
       bgp_set_attr_data(to, BA_NEXT_HOP, 0, nh, 16);
 
       if (s->mpls)
       {
 	u32 implicit_null = BGP_MPLS_NULL;
-	u32 *labels = ra->nh.labels ? ra->nh.label : &implicit_null;
-	uint lnum = ra->nh.labels ? ra->nh.labels : 1;
+	u32 *labels = nhloc->labels ? nhloc->label : &implicit_null;
+	uint lnum = nhloc->labels ? nhloc->labels : 1;
 	bgp_set_attr_data(to, BA_MPLS_LABEL_STACK, 0, labels, lnum * 4);
       }
     }
diff --git a/proto/ospf/rt.c b/proto/ospf/rt.c
index 91739056..6070fd34 100644
--- a/proto/ospf/rt.c
+++ b/proto/ospf/rt.c
@@ -28,24 +28,30 @@ nh_is_vlink(struct nexthop *nhs)
 static inline int
 unresolved_vlink(ort *ort)
 {
-  return ort->n.nhs && nh_is_vlink(ort->n.nhs);
+  return ort->n.nhs && nh_is_vlink(&ort->n.nhs->nh);
 }
 
-static inline struct nexthop *
+static inline struct nexthop_adata *
 new_nexthop(struct ospf_proto *p, ip_addr gw, struct iface *iface, byte weight)
 {
-  struct nexthop *nh = lp_allocz(p->nhpool, sizeof(struct nexthop));
-  nh->gw = gw;
-  nh->iface = iface;
-  nh->weight = weight;
-  return nh;
+  struct nexthop_adata *nhad = lp_alloc(p->nhpool, sizeof(struct nexthop_adata));
+  *nhad = (struct nexthop_adata) {
+    .ad = { .length = sizeof *nhad - sizeof nhad->ad, },
+    .nh = {
+      .gw = gw,
+      .iface = iface,
+      .weight = weight,
+    },
+  };
+
+  return nhad;
 }
 
 /* Returns true if there are device nexthops in n */
 static inline int
-has_device_nexthops(const struct nexthop *n)
+has_device_nexthops(struct nexthop_adata *nhad)
 {
-  for (; n; n = n->next)
+  NEXTHOP_WALK(n, nhad)
     if (ipa_zero(n->gw))
       return 1;
 
@@ -53,38 +59,22 @@ has_device_nexthops(const struct nexthop *n)
 }
 
 /* Replace device nexthops with nexthops to gw */
-static struct nexthop *
-fix_device_nexthops(struct ospf_proto *p, const struct nexthop *n, ip_addr gw)
+static struct nexthop_adata *
+fix_device_nexthops(struct ospf_proto *p, struct nexthop_adata *old, ip_addr gw)
 {
-  struct nexthop *root1 = NULL;
-  struct nexthop *root2 = NULL;
-  struct nexthop **nn1 = &root1;
-  struct nexthop **nn2 = &root2;
-
   if (!p->ecmp)
-    return new_nexthop(p, gw, n->iface, n->weight);
-
-  /* This is a bit tricky. We cannot just copy the list and update n->gw,
-     because the list should stay sorted, so we create two lists, one with new
-     gateways and one with old ones, and then merge them. */
-
-  for (; n; n = n->next)
   {
-    struct nexthop *nn = new_nexthop(p, ipa_zero(n->gw) ? gw : n->gw, n->iface, n->weight);
-
-    if (ipa_zero(n->gw))
-    {
-      *nn1 = nn;
-      nn1 = &(nn->next);
-    }
-    else
-    {
-      *nn2 = nn;
-      nn2 = &(nn->next);
-    }
+    struct nexthop_adata *new = (struct nexthop_adata *) lp_store_adata(p->nhpool, old->ad.data, old->ad.length);
+    new->nh.gw = gw;
+    return new;
   }
 
-  return nexthop_merge(root1, root2, 1, 1, p->ecmp, p->nhpool);
+  struct nexthop_adata *tmp = (struct nexthop_adata *) tmp_copy_adata(&old->ad);
+  NEXTHOP_WALK(n, tmp)
+    if (ipa_zero(n->gw))
+      n->gw = gw;
+
+  return nexthop_sort(tmp, p->nhpool);
 }
 
 
@@ -169,9 +159,9 @@ orta_compare(const struct ospf_proto *p, const orta *new, const orta *old)
     return -1;
   if (!new->nhs)
     return 1;
-  if (nh_is_vlink(new->nhs))
+  if (nh_is_vlink(&new->nhs->nh))
     return -1;
-  if (nh_is_vlink(old->nhs))
+  if (nh_is_vlink(&old->nhs->nh))
     return 1;
 
 
@@ -279,11 +269,7 @@ ort_merge(struct ospf_proto *p, ort *o, const orta *new)
   orta *old = &o->n;
 
   if (old->nhs != new->nhs)
-  {
-    old->nhs = nexthop_merge(old->nhs, new->nhs, old->nhs_reuse, new->nhs_reuse,
-			  p->ecmp, p->nhpool);
-    old->nhs_reuse = 1;
-  }
+    old->nhs = nexthop_merge(old->nhs, new->nhs, p->ecmp, p->nhpool);
 
   if (old->rid < new->rid)
     old->rid = new->rid;
@@ -295,11 +281,7 @@ ort_merge_ext(struct ospf_proto *p, ort *o, const orta *new)
   orta *old = &o->n;
 
   if (old->nhs != new->nhs)
-  {
-    old->nhs = nexthop_merge(old->nhs, new->nhs, old->nhs_reuse, new->nhs_reuse,
-			  p->ecmp, p->nhpool);
-    old->nhs_reuse = 1;
-  }
+    old->nhs = nexthop_merge(old->nhs, new->nhs, p->ecmp, p->nhpool);
 
   if (old->tag != new->tag)
     old->tag = 0;
@@ -1165,7 +1147,7 @@ ospf_check_vlinks(struct ospf_proto *p)
 
       if (tmp && (tmp->color == INSPF) && ipa_nonzero(tmp->lb) && tmp->nhs)
       {
-	struct ospf_iface *nhi = ospf_iface_find(p, tmp->nhs->iface);
+	struct ospf_iface *nhi = ospf_iface_find(p, tmp->nhs->nh.iface);
 
 	if ((ifa->state != OSPF_IS_PTP)
 	    || (ifa->vifa != nhi)
@@ -1579,10 +1561,7 @@ ospf_ext_spf(struct ospf_proto *p)
 
       /* Replace device nexthops with nexthops to forwarding address from LSA */
       if (has_device_nexthops(nfa.nhs))
-      {
 	nfa.nhs = fix_device_nexthops(p, nfa.nhs, rt.fwaddr);
-	nfa.nhs_reuse = 1;
-      }
     }
 
     if (rt.ebit)
@@ -1726,10 +1705,10 @@ ospf_rt_spf(struct ospf_proto *p)
 
 
 static inline int
-inherit_nexthops(struct nexthop *pn)
+inherit_nexthops(struct nexthop_adata *pn)
 {
   /* Proper nexthops (with defined GW) or dummy vlink nexthops (without iface) */
-  return pn && (ipa_nonzero(pn->gw) || !pn->iface);
+  return pn && (ipa_nonzero(pn->nh.gw) || !pn->nh.iface);
 }
 
 static inline ip_addr
@@ -1744,12 +1723,12 @@ link_lsa_lladdr(struct ospf_proto *p, struct top_hash_entry *en)
   return ospf_is_ip4(p) ? ipa_from_ip4(ospf3_6to4(ll)) : ipa_from_ip6(ll);
 }
 
-static struct nexthop *
+static struct nexthop_adata *
 calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en,
 	      struct top_hash_entry *par, int pos, uint data, uint lif, uint nif)
 {
   struct ospf_proto *p = oa->po;
-  struct nexthop *pn = par->nhs;
+  struct nexthop_adata *pn = par->nhs;
   struct top_hash_entry *link = NULL;
   struct ospf_iface *ifa = NULL;
   ip_addr nh = IPA_NONE;
@@ -1827,10 +1806,10 @@ calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en,
 	return NULL;
     }
 
-    struct nexthop *nhs = new_nexthop(p, nh, ifa->iface, ifa->ecmp_weight);
+    struct nexthop_adata *nhs = new_nexthop(p, nh, ifa->iface, ifa->ecmp_weight);
 
     if (ifa->addr->flags & IA_HOST)
-      nhs->flags = RNF_ONLINK;
+      nhs->nh.flags = RNF_ONLINK;
 
     return nhs;
   }
@@ -1851,7 +1830,7 @@ calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en,
       if (ipa_zero(en->lb))
 	goto bad;
 
-      return new_nexthop(p, en->lb, pn->iface, pn->weight);
+      return new_nexthop(p, en->lb, pn->nh.iface, pn->nh.weight);
     }
     else /* OSPFv3 */
     {
@@ -1859,7 +1838,7 @@ calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en,
        * Next-hop is taken from lladdr field of Link-LSA, en->lb_id
        * is computed in link_back().
        */
-      link = ospf_hash_find(p->gr, pn->iface->index, en->lb_id, rid, LSA_T_LINK);
+      link = ospf_hash_find(p->gr, pn->nh.iface->index, en->lb_id, rid, LSA_T_LINK);
       if (!link)
 	return NULL;
 
@@ -1867,7 +1846,7 @@ calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en,
       if (ipa_zero(nh))
 	return NULL;
 
-      return new_nexthop(p, nh, pn->iface, pn->weight);
+      return new_nexthop(p, nh, pn->nh.iface, pn->nh.weight);
     }
   }
 
@@ -1914,7 +1893,7 @@ add_cand(struct ospf_area *oa, struct top_hash_entry *en, struct top_hash_entry
   if (!link_back(oa, en, par, lif, nif))
     return;
 
-  struct nexthop *nhs = calc_next_hop(oa, en, par, pos, data, lif, nif);
+  struct nexthop_adata *nhs = calc_next_hop(oa, en, par, pos, data, lif, nif);
   if (!nhs)
   {
     log(L_WARN "%s: Cannot find next hop for LSA (Type: %04x, Id: %R, Rt: %R)",
@@ -1923,7 +1902,7 @@ add_cand(struct ospf_area *oa, struct top_hash_entry *en, struct top_hash_entry
   }
 
   /* If en->dist > 0, we know that en->color == CANDIDATE and en->nhs is defined. */
-  if ((dist == en->dist) && !nh_is_vlink(en->nhs))
+  if ((dist == en->dist) && !nh_is_vlink(&en->nhs->nh))
   {
     /*
      * For multipath, we should merge nexthops. We merge regular nexthops only.
@@ -1947,13 +1926,11 @@ add_cand(struct ospf_area *oa, struct top_hash_entry *en, struct top_hash_entry
      */
 
     /* Keep old ones */
-    if (!p->ecmp || nh_is_vlink(nhs) || (nhs == en->nhs))
+    if (!p->ecmp || nh_is_vlink(&nhs->nh) || (nhs == en->nhs))
       return;
 
     /* Merge old and new */
-    int new_reuse = (par->nhs != nhs);
-    en->nhs = nexthop_merge(en->nhs, nhs, en->nhs_reuse, new_reuse, p->ecmp, p->nhpool);
-    en->nhs_reuse = 1;
+    en->nhs = nexthop_merge(en->nhs, nhs, p->ecmp, p->nhpool);
     return;
   }
 
@@ -1967,7 +1944,6 @@ add_cand(struct ospf_area *oa, struct top_hash_entry *en, struct top_hash_entry
   en->nhs = nhs;
   en->dist = dist;
   en->color = CANDIDATE;
-  en->nhs_reuse = (par->nhs != nhs);
 
   prev = NULL;
 
@@ -2008,10 +1984,23 @@ ort_changed(ort *nf, rta *nr)
   if (!or ||
     (nf->n.metric1 != nf->old_metric1) || (nf->n.metric2 != nf->old_metric2) ||
     (nf->n.tag != nf->old_tag) || (nf->n.rid != nf->old_rid) ||
-    (nr->dest != or->dest) ||
-    !nexthop_same(&(nr->nh), &(or->nh)))
+    (nr->dest != or->dest))
     return 1;
 
+  eattr *nhea_n = ea_find(nr->eattrs, &ea_gen_nexthop);
+  eattr *nhea_o = ea_find(or->eattrs, &ea_gen_nexthop);
+  if (!nhea_n != !nhea_o)
+    return 1;
+
+  if (nhea_n && nhea_o)
+  {
+    struct nexthop_adata *nhad_n = (struct nexthop_adata *) nhea_n->u.ptr;
+    struct nexthop_adata *nhad_o = (struct nexthop_adata *) nhea_o->u.ptr;
+
+    if (!nexthop_same(nhad_n, nhad_o))
+      return 1;
+  }
+
   if (	ea_get_int(nr->eattrs, &ea_gen_source, 0)
      != ea_get_int(or->eattrs, &ea_gen_source, 0))
     return 1;
@@ -2038,10 +2027,9 @@ again1:
   FIB_ITERATE_START(fib, &fit, ort, nf)
   {
     /* Sanity check of next-hop addresses, failure should not happen */
-    if (nf->n.type)
+    if (nf->n.type && nf->n.nhs)
     {
-      struct nexthop *nh;
-      for (nh = nf->n.nhs; nh; nh = nh->next)
+      NEXTHOP_WALK(nh, nf->n.nhs)
 	if (ipa_nonzero(nh->gw))
 	{
 	  neighbor *nbr = neigh_find(&p->p, nh->gw, nh->iface,
@@ -2062,9 +2050,24 @@ again1:
     {
       rta a0 = {
 	.dest = RTD_UNICAST,
-	.nh = *(nf->n.nhs),
       };
 
+      struct {
+	ea_list l;
+	eattr a[7];
+      } eattrs;
+
+      eattrs.l = (ea_list) {};
+
+      eattrs.a[eattrs.l.count++] =
+	EA_LITERAL_EMBEDDED(&ea_gen_preference, 0, p->p.main_channel->preference);
+
+      eattrs.a[eattrs.l.count++] = 
+	EA_LITERAL_EMBEDDED(&ea_gen_source, 0, nf->n.type);
+
+      eattrs.a[eattrs.l.count++] =
+	EA_LITERAL_DIRECT_ADATA(&ea_gen_nexthop, 0, &nf->n.nhs->ad);
+
       if (reload || ort_changed(nf, &a0))
       {
 	nf->old_metric1 = nf->n.metric1;
@@ -2072,19 +2075,6 @@ again1:
 	nf->old_tag = nf->n.tag;
 	nf->old_rid = nf->n.rid;
 
-	struct {
-	  ea_list l;
-	  eattr a[6];
-	} eattrs;
-
-	eattrs.l = (ea_list) {};
-
-	eattrs.a[eattrs.l.count++] =
-	  EA_LITERAL_EMBEDDED(&ea_gen_preference, 0, p->p.main_channel->preference);
-
-	eattrs.a[eattrs.l.count++] = 
-	  EA_LITERAL_EMBEDDED(&ea_gen_source, 0, nf->n.type);
-
 	eattrs.a[eattrs.l.count++] =
 	  EA_LITERAL_EMBEDDED(&ea_ospf_metric1, 0, nf->n.metric1);
 
diff --git a/proto/ospf/rt.h b/proto/ospf/rt.h
index 094e125b..180216b7 100644
--- a/proto/ospf/rt.h
+++ b/proto/ospf/rt.h
@@ -18,8 +18,6 @@
 typedef struct orta
 {
   u8 type;			/* RTS_OSPF_* */
-  u8 nhs_reuse;			/* Whether nhs nodes can be reused during merging.
-				   See a note in rt.c:add_cand() */
   u32 options;
   /*
    * For ORT_ROUTER routes, options field are router-LSA style
@@ -53,7 +51,7 @@ typedef struct orta
   struct ospf_area *oa;
   struct ospf_area *voa;	/* Used when route is replaced in ospf_rt_sum_tr(),
 				   NULL otherwise */
-  struct nexthop *nhs;		/* Next hops computed during SPF */
+  struct nexthop_adata *nhs;	/* Next hops computed during SPF */
   struct top_hash_entry *en;	/* LSA responsible for this orta */
 }
 orta;
diff --git a/proto/ospf/topology.c b/proto/ospf/topology.c
index db423dc8..ca4620cc 100644
--- a/proto/ospf/topology.c
+++ b/proto/ospf/topology.c
@@ -1366,8 +1366,20 @@ ospf_rt_notify(struct proto *P, struct channel *ch UNUSED, net *n, rte *new, rte
   uint tag = ea_get_int(a->eattrs, &ea_ospf_tag, 0);
 
   ip_addr fwd = IPA_NONE;
-  if ((a->dest == RTD_UNICAST) && use_gw_for_fwaddr(p, a->nh.gw, a->nh.iface))
-    fwd = a->nh.gw;
+  if (a->dest == RTD_UNICAST)
+  {
+    eattr *nhea = ea_find(a->eattrs, &ea_gen_nexthop);
+    if (!nhea)
+    {
+      log(L_ERR "%s: Unicast route without nexthop for %N",
+	  p->p.name, n->n.addr);
+      return;
+    }
+
+    struct nexthop_adata *nhad = (struct nexthop_adata *) nhea->u.ptr;
+    if (use_gw_for_fwaddr(p, nhad->nh.gw, nhad->nh.iface))
+      fwd = nhad->nh.gw;
+  }
 
   /* NSSA-LSA with P-bit set must have non-zero forwarding address */
   if (oa && ipa_zero(fwd))
diff --git a/proto/ospf/topology.h b/proto/ospf/topology.h
index 535d1f1b..fe102f77 100644
--- a/proto/ospf/topology.h
+++ b/proto/ospf/topology.h
@@ -28,7 +28,7 @@ struct top_hash_entry
   u16 next_lsa_opts;		/* For postponed LSA origination */
   btime inst_time;		/* Time of installation into DB */
   struct ort *nf;		/* Reference fibnode for sum and ext LSAs, NULL for otherwise */
-  struct nexthop *nhs;		/* Computed nexthops - valid only in ospf_rt_spf() */
+  struct nexthop_adata *nhs;	/* Computed nexthops - valid only in ospf_rt_spf() */
   ip_addr lb;			/* In OSPFv2, link back address. In OSPFv3, any global address in the area useful for vlinks */
   u32 lb_id;			/* Interface ID of link back iface (for bcast or NBMA networks) */
   u32 dist;			/* Distance from the root */
@@ -39,8 +39,6 @@ struct top_hash_entry
 #define CANDIDATE 1
 #define INSPF 2
   u8 mode;			/* LSA generated during RT calculation (LSA_RTCALC or LSA_STALE)*/
-  u8 nhs_reuse;			/* Whether nhs nodes can be reused during merging.
-				   See a note in rt.c:add_cand() */
 };
 
 
diff --git a/proto/perf/perf.c b/proto/perf/perf.c
index 4329556c..8642e0a1 100644
--- a/proto/perf/perf.c
+++ b/proto/perf/perf.c
@@ -144,13 +144,19 @@ perf_loop(void *data)
     if (!p->attrs_per_rte || !(i % p->attrs_per_rte)) {
       struct rta a0 = {
 	.dest = RTD_UNICAST,
+      };
+
+      ea_set_attr_u32(&a0.eattrs, &ea_gen_preference, 0, p->p.main_channel->preference);
+      ea_set_attr_u32(&a0.eattrs, &ea_gen_source, 0, RTS_PERF);
+
+      struct nexthop_adata nhad = {
 	.nh.iface = p->ifa->iface,
 	.nh.gw = gw,
 	.nh.weight = 1,
       };
 
-      ea_set_attr_u32(&a0.eattrs, &ea_gen_preference, 0, p->p.main_channel->preference);
-      ea_set_attr_u32(&a0.eattrs, &ea_gen_source, 0, RTS_PERF);
+      ea_set_attr_data(&a0.eattrs, &ea_gen_nexthop, 0,
+	  &nhad.ad.data, sizeof nhad - sizeof nhad.ad);
 
       p->data[i].a = rta_lookup(&a0);
     }
diff --git a/proto/rip/rip.c b/proto/rip/rip.c
index f7f34c27..425a411c 100644
--- a/proto/rip/rip.c
+++ b/proto/rip/rip.c
@@ -169,38 +169,58 @@ rip_announce_rte(struct rip_proto *p, struct rip_entry *en)
     a0.eattrs = &ea_block.l;
 
     u16 rt_tag = rt->tag;
+    struct iface *rt_from = NULL;
 
     if (p->ecmp)
     {
       /* ECMP route */
-      struct nexthop *nhs = NULL;
       int num = 0;
 
+      for (rt = en->routes; rt && (num < p->ecmp); rt = rt->next)
+	if (rip_valid_rte(rt))
+	  num++;
+
+      struct nexthop_adata *nhad = (struct nexthop_adata *) tmp_alloc_adata((num+1) * sizeof(struct nexthop));
+      struct nexthop *nh = &nhad->nh;
+
       for (rt = en->routes; rt && (num < p->ecmp); rt = rt->next)
       {
 	if (!rip_valid_rte(rt))
-	    continue;
+	  continue;
 
-	struct nexthop *nh = allocz(sizeof(struct nexthop));
+	*nh = (struct nexthop) {
+	  .gw = rt->next_hop,
+	  .iface = rt->from->ifa->iface,
+	  .weight = rt->from->ifa->cf->ecmp_weight,
+	};
 
-	nh->gw = rt->next_hop;
-	nh->iface = rt->from->ifa->iface;
-	nh->weight = rt->from->ifa->cf->ecmp_weight;
+	if (!rt_from)
+	  rt_from = rt->from->ifa->iface;
 
-	nexthop_insert(&nhs, nh);
-	num++;
+	nh = NEXTHOP_NEXT(nh);
 
 	if (rt->tag != rt_tag)
 	  rt_tag = 0;
       }
 
-      a0.nh = *nhs;
+      nhad->ad.length = ((void *) nh - (void *) nhad->ad.data);
+
+      ea_set_attr(&a0.eattrs,
+	  EA_LITERAL_DIRECT_ADATA(&ea_gen_nexthop, 0,
+	    &(nexthop_sort(nhad, tmp_linpool)->ad)));
     }
     else
     {
       /* Unipath route */
-      a0.nh.gw = rt->next_hop;
-      a0.nh.iface = rt->from->ifa->iface;
+      rt_from = rt->from->ifa->iface;
+
+      struct nexthop_adata nhad = {
+	.nh.gw = rt->next_hop,
+	.nh.iface = rt->from->ifa->iface,
+      };
+
+      ea_set_attr_data(&a0.eattrs, &ea_gen_nexthop, 0,
+	  &nhad.ad.data, sizeof nhad - sizeof nhad.ad);
       ea_set_attr_data(&a0.eattrs, &ea_gen_from, 0, &rt->from->nbr->addr, sizeof(ip_addr));
     }
 
@@ -208,7 +228,7 @@ rip_announce_rte(struct rip_proto *p, struct rip_entry *en)
 
     struct rip_iface_adata riad = {
       .ad = { .length = sizeof(struct rip_iface_adata) - sizeof(struct adata) },
-      .iface = a0.nh.iface,
+      .iface = rt_from,
     };
     ea_set_attr(&a0.eattrs,
 	EA_LITERAL_DIRECT_ADATA(&ea_rip_from, 0, &riad.ad));
@@ -362,8 +382,14 @@ rip_rt_notify(struct proto *P, struct channel *ch UNUSED, struct network *net, s
     en->metric = rt_metric;
     en->tag = rt_tag;
     en->from = (new->src->proto == P) ? rt_from : NULL;
-    en->iface = new->attrs->nh.iface;
-    en->next_hop = new->attrs->nh.gw;
+
+    eattr *nhea = ea_find(new->attrs->eattrs, &ea_gen_nexthop);
+    if (nhea)
+    {
+      struct nexthop_adata *nhad = (struct nexthop_adata *) nhea->u.ptr;
+      en->iface = nhad->nh.iface;
+      en->next_hop = nhad->nh.gw;
+    }
   }
   else
   {
diff --git a/proto/static/static.c b/proto/static/static.c
index e792a148..2e4a46a6 100644
--- a/proto/static/static.c
+++ b/proto/static/static.c
@@ -61,32 +61,40 @@ static_announce_rte(struct static_proto *p, struct static_route *r)
 
   if (r->dest == RTD_UNICAST)
   {
-    struct static_route *r2;
-    struct nexthop *nhs = NULL;
+    uint sz = 0;
+    for (struct static_route *r2 = r; r2; r2 = r2->mp_next)
+      if (r2->active)
+	sz += NEXTHOP_SIZE_CNT(r2->mls ? r2->mls->length / sizeof(u32) : 0);
 
-    for (r2 = r; r2; r2 = r2->mp_next)
+    if (!sz)
+      goto withdraw;
+
+    struct nexthop_adata *nhad = allocz(sz + sizeof *nhad);
+    struct nexthop *nh = &nhad->nh;
+
+    for (struct static_route *r2 = r; r2; r2 = r2->mp_next)
     {
       if (!r2->active)
 	continue;
 
-      struct nexthop *nh = allocz(NEXTHOP_MAX_SIZE);
-      nh->gw = r2->via;
-      nh->iface = r2->neigh->iface;
-      nh->flags = r2->onlink ? RNF_ONLINK : 0;
-      nh->weight = r2->weight;
+      *nh = (struct nexthop) {
+	.gw = r2->via,
+	.iface = r2->neigh->iface,
+	.flags = r2->onlink ? RNF_ONLINK : 0,
+	.weight = r2->weight,
+      };
+
       if (r2->mls)
       {
 	nh->labels = r2->mls->length / sizeof(u32);
 	memcpy(nh->label, r2->mls->data, r2->mls->length);
       }
 
-      nexthop_insert(&nhs, nh);
+      nh = NEXTHOP_NEXT(nh);
     }
 
-    if (!nhs)
-      goto withdraw;
-
-    nexthop_link(a, nhs);
+    ea_set_attr_data(&a->eattrs, &ea_gen_nexthop, 0,
+	nhad->ad.data, (void *) nh - (void *) nhad->ad.data);
   }
 
   if (r->dest == RTDX_RECURSIVE)
diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index e0219ce0..fdfd4885 100644
--- a/sysdep/linux/netlink.c
+++ b/sysdep/linux/netlink.c
@@ -827,12 +827,12 @@ nl_add_nexthop(struct nlmsghdr *h, uint bufsize, struct nexthop *nh, int af UNUS
 }
 
 static void
-nl_add_multipath(struct nlmsghdr *h, uint bufsize, struct nexthop *nh, int af, ea_list *eattrs)
+nl_add_multipath(struct nlmsghdr *h, uint bufsize, struct nexthop_adata *nhad, int af, ea_list *eattrs)
 {
   struct rtattr *a = nl_open_attr(h, bufsize, RTA_MULTIPATH);
   eattr *flow = ea_find(eattrs, &ea_krt_realm);
 
-  for (; nh; nh = nh->next)
+  NEXTHOP_WALK(nh, nhad)
   {
     struct rtnexthop *rtnh = nl_open_nexthop(h, bufsize);
 
@@ -856,31 +856,44 @@ nl_add_multipath(struct nlmsghdr *h, uint bufsize, struct nexthop *nh, int af, e
   nl_close_attr(h, a);
 }
 
-static struct nexthop *
+static struct nexthop_adata *
 nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, const net_addr *n, struct rtattr *ra, int af, int krt_src)
 {
   struct rtattr *a[BIRD_RTA_MAX];
-  struct rtnexthop *nh = RTA_DATA(ra);
-  struct nexthop *rv, *first, **last;
-  unsigned len = RTA_PAYLOAD(ra);
+  struct rtnexthop *nh, *orig_nh = RTA_DATA(ra);
+  unsigned len, orig_len = RTA_PAYLOAD(ra);
+  uint cnt = 0;
 
-  first = NULL;
-  last = &first;
-
-  while (len)
+  /* First count the nexthops */
+  for (len = orig_len, nh = orig_nh; len; len -= NLMSG_ALIGN(nh->rtnh_len), nh = RTNH_NEXT(nh))
     {
       /* Use RTNH_OK(nh,len) ?? */
       if ((len < sizeof(*nh)) || (len < nh->rtnh_len))
 	goto err;
 
       if ((nh->rtnh_flags & RTNH_F_DEAD) && (krt_src != KRT_SRC_BIRD))
-	goto next;
+	;
+      else
+	cnt++;
+    }
 
-      *last = rv = lp_allocz(s->pool, NEXTHOP_MAX_SIZE);
-      last = &(rv->next);
+  struct nexthop_adata *nhad = lp_allocz(s->pool, cnt * NEXTHOP_MAX_SIZE + sizeof *nhad);
+  struct nexthop *rv = &nhad->nh;
+
+  for (len = orig_len, nh = orig_nh; len; len -= NLMSG_ALIGN(nh->rtnh_len), nh = RTNH_NEXT(nh))
+    {
+      /* Use RTNH_OK(nh,len) ?? */
+      if ((len < sizeof(*nh)) || (len < nh->rtnh_len))
+	goto err;
+
+      if ((nh->rtnh_flags & RTNH_F_DEAD) && (krt_src != KRT_SRC_BIRD))
+	continue;
+
+      *rv = (struct nexthop) {
+	.weight = nh->rtnh_hops,
+	.iface = if_find_by_index(nh->rtnh_ifindex),
+      };
 
-      rv->weight = nh->rtnh_hops;
-      rv->iface = if_find_by_index(nh->rtnh_ifindex);
       if (!rv->iface)
 	{
 	  log(L_ERR "KRT: Received route %N with unknown ifindex %u", n, nh->rtnh_ifindex);
@@ -959,16 +972,14 @@ nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, const net_addr
       }
 #endif
 
-    next:
-      len -= NLMSG_ALIGN(nh->rtnh_len);
-      nh = RTNH_NEXT(nh);
+      rv = NEXTHOP_NEXT(rv);
     }
 
-  /* Ensure nexthops are sorted to satisfy nest invariant */
-  if (!nexthop_is_sorted(first))
-    first = nexthop_sort(first);
+  /* Store final length */
+  nhad->ad.length = (void *) rv - (void *) nhad->ad.data;
 
-  return first;
+  /* Ensure nexthops are sorted to satisfy nest invariant */
+  return nexthop_is_sorted(nhad) ? nhad : nexthop_sort(nhad, s->pool);
 
 err:
   log(L_ERR "KRT: Received strange multipath route %N", n);
@@ -1412,22 +1423,23 @@ krt_capable(rte *e)
 }
 
 static inline int
-nh_bufsize(struct nexthop *nh)
+nh_bufsize(struct nexthop_adata *nhad)
 {
   int rv = 0;
-  for (; nh != NULL; nh = nh->next)
+  NEXTHOP_WALK(nh, nhad)
     rv += RTNH_LENGTH(RTA_LENGTH(sizeof(ip_addr)));
   return rv;
 }
 
 static int
-nl_send_route(struct krt_proto *p, rte *e, int op, int dest, struct nexthop *nh)
+nl_send_route(struct krt_proto *p, rte *e, int op, int dest, struct nexthop_adata *nh)
 {
   eattr *ea;
   net *net = e->net;
   rta *a = e->attrs;
   ea_list *eattrs = a->eattrs;
-  int bufsize = 128 + KRT_METRICS_MAX*8 + nh_bufsize(&(a->nh));
+
+  int bufsize = 128 + KRT_METRICS_MAX*8 + (nh ? nh_bufsize(nh) : 0);
   u32 priority = 0;
 
   struct {
@@ -1511,7 +1523,7 @@ nl_send_route(struct krt_proto *p, rte *e, int op, int dest, struct nexthop *nh)
   else if (ea = ea_find(eattrs, &ea_krt_scope))
     r->r.rtm_scope = ea->u.data;
   else
-    r->r.rtm_scope = (dest == RTD_UNICAST && ipa_zero(nh->gw)) ? RT_SCOPE_LINK : RT_SCOPE_UNIVERSE;
+    r->r.rtm_scope = (dest == RTD_UNICAST && ipa_zero(nh->nh.gw)) ? RT_SCOPE_LINK : RT_SCOPE_UNIVERSE;
 
   if (ea = ea_find(eattrs, &ea_krt_prefsrc))
     nl_add_attr_ipa(&r->h, rsize, RTA_PREFSRC, *(ip_addr *)ea->u.ptr->data);
@@ -1540,14 +1552,14 @@ dest:
     {
     case RTD_UNICAST:
       r->r.rtm_type = RTN_UNICAST;
-      if (nh->next && !krt_ecmp6(p))
+      if (!NEXTHOP_ONE(nh) && !krt_ecmp6(p))
 	nl_add_multipath(&r->h, rsize, nh, p->af, eattrs);
       else
       {
-	nl_add_attr_u32(&r->h, rsize, RTA_OIF, nh->iface->index);
-	nl_add_nexthop(&r->h, rsize, nh, p->af);
+	nl_add_attr_u32(&r->h, rsize, RTA_OIF, nh->nh.iface->index);
+	nl_add_nexthop(&r->h, rsize, &nh->nh, p->af);
 
-	if (nh->flags & RNF_ONLINK)
+	if (nh->nh.flags & RNF_ONLINK)
 	  r->r.rtm_flags |= RTNH_F_ONLINK;
       }
       break;
@@ -1576,21 +1588,35 @@ nl_add_rte(struct krt_proto *p, rte *e)
   rta *a = e->attrs;
   int err = 0;
 
-  if (krt_ecmp6(p) && a->nh.next)
+  eattr *nhea = ea_find(a->eattrs, &ea_gen_nexthop);
+  struct nexthop_adata *nhad = nhea ? (struct nexthop_adata *) nhea->u.ptr : NULL;
+
+  if (krt_ecmp6(p) && nhad && !NEXTHOP_ONE(nhad))
   {
-    struct nexthop *nh = &(a->nh);
+    uint cnt = 0;
+    NEXTHOP_WALK(nh, nhad)
+    {
+      struct {
+	struct nexthop_adata nhad;
+	u32 labels[MPLS_MAX_LABEL_STACK];
+      } nhx;
+      memcpy(&nhx.nhad.nh, nh, NEXTHOP_SIZE(nh));
+      nhx.nhad.ad.length = (void *) NEXTHOP_NEXT(&nhx.nhad.nh) - (void *) nhx.nhad.ad.data;
 
-    err = nl_send_route(p, e, NL_OP_ADD, RTD_UNICAST, nh);
-    if (err < 0)
-      return err;
-
-    for (nh = nh->next; nh; nh = nh->next)
-      err += nl_send_route(p, e, NL_OP_APPEND, RTD_UNICAST, nh);
+      if (!cnt++)
+      {
+	err = nl_send_route(p, e, NL_OP_ADD, RTD_UNICAST, &nhx.nhad);
+	if (err < 0)
+	  return err;
+      }
+      else
+	err += nl_send_route(p, e, NL_OP_APPEND, RTD_UNICAST, &nhx.nhad);
+    }
 
     return err;
   }
 
-  return nl_send_route(p, e, NL_OP_ADD, a->dest, &(a->nh));
+  return nl_send_route(p, e, NL_OP_ADD, a->dest, nhad);
 }
 
 static inline int
@@ -1610,7 +1636,9 @@ static inline int
 nl_replace_rte(struct krt_proto *p, rte *e)
 {
   rta *a = e->attrs;
-  return nl_send_route(p, e, NL_OP_REPLACE, a->dest, &(a->nh));
+  eattr *nhea = ea_find(a->eattrs, &ea_gen_nexthop);
+  struct nexthop_adata *nhad = nhea ? (struct nexthop_adata *) nhea->u.ptr : NULL;
+  return nl_send_route(p, e, NL_OP_REPLACE, a->dest, nhad);
 }
 
 
@@ -1861,6 +1889,15 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
   else
     s->rta_flow = 0;
 
+  union {
+    struct {
+      struct adata ad;
+      struct nexthop nh;
+      u32 labels[MPLS_MAX_LABEL_STACK];
+    };
+    struct nexthop_adata nhad;
+  } nhad = {};
+
   switch (i->rtm_type)
     {
     case RTN_UNICAST:
@@ -1868,49 +1905,50 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
 
       if (a[RTA_MULTIPATH])
         {
-	  struct nexthop *nh = nl_parse_multipath(s, p, n, a[RTA_MULTIPATH], i->rtm_family, krt_src);
+	  struct nexthop_adata *nh = nl_parse_multipath(s, p, n, a[RTA_MULTIPATH], i->rtm_family, krt_src);
 	  if (!nh)
 	    SKIP("strange RTA_MULTIPATH\n");
 
-	  nexthop_link(ra, nh);
+	  ea_set_attr(&ra->eattrs, EA_LITERAL_DIRECT_ADATA(
+		&ea_gen_nexthop, 0, &nh->ad));
 	  break;
 	}
 
       if ((i->rtm_flags & RTNH_F_DEAD) && (krt_src != KRT_SRC_BIRD))
 	SKIP("ignore RTNH_F_DEAD\n");
 
-      ra->nh.iface = if_find_by_index(oif);
-      if (!ra->nh.iface)
+      nhad.nh.iface = if_find_by_index(oif);
+      if (!nhad.nh.iface)
 	{
 	  log(L_ERR "KRT: Received route %N with unknown ifindex %u", net->n.addr, oif);
 	  return;
 	}
 
       if (a[RTA_GATEWAY])
-	ra->nh.gw = rta_get_ipa(a[RTA_GATEWAY]);
+	nhad.nh.gw = rta_get_ipa(a[RTA_GATEWAY]);
 
 #ifdef HAVE_MPLS_KERNEL
       if (a[RTA_VIA])
-	ra->nh.gw = rta_get_via(a[RTA_VIA]);
+	nhad.nh.gw = rta_get_via(a[RTA_VIA]);
 #endif
 
-      if (ipa_nonzero(ra->nh.gw))
+      if (ipa_nonzero(nhad.nh.gw))
 	{
 	  /* Silently skip strange 6to4 routes */
 	  const net_addr_ip6 sit = NET_ADDR_IP6(IP6_NONE, 96);
-	  if ((i->rtm_family == AF_INET6) && ipa_in_netX(ra->nh.gw, (net_addr *) &sit))
+	  if ((i->rtm_family == AF_INET6) && ipa_in_netX(nhad.nh.gw, (net_addr *) &sit))
 	    return;
 
 	  if (i->rtm_flags & RTNH_F_ONLINK)
-	    ra->nh.flags |= RNF_ONLINK;
+	    nhad.nh.flags |= RNF_ONLINK;
 
 	  neighbor *nbr;
-	  nbr = neigh_find(&p->p, ra->nh.gw, ra->nh.iface,
-			   (ra->nh.flags & RNF_ONLINK) ? NEF_ONLINK : 0);
+	  nbr = neigh_find(&p->p, nhad.nh.gw, nhad.nh.iface,
+			   (nhad.nh.flags & RNF_ONLINK) ? NEF_ONLINK : 0);
 	  if (!nbr || (nbr->scope == SCOPE_HOST))
 	    {
 	      log(L_ERR "KRT: Received route %N with strange next-hop %I", net->n.addr,
-                  ra->nh.gw);
+                  nhad.nh.gw);
 	      return;
 	    }
 	}
@@ -1932,10 +1970,10 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
     }
 
 #ifdef HAVE_MPLS_KERNEL
-  if ((i->rtm_family == AF_MPLS) && a[RTA_NEWDST] && !ra->nh.next)
-    ra->nh.labels = rta_get_mpls(a[RTA_NEWDST], ra->nh.label);
+  if ((i->rtm_family == AF_MPLS) && a[RTA_NEWDST] && !a[RTA_MULTIPATH])
+    nhad.nh.labels = rta_get_mpls(a[RTA_NEWDST], nhad.nh.label);
 
-  if (a[RTA_ENCAP] && a[RTA_ENCAP_TYPE] && !ra->nh.next)
+  if (a[RTA_ENCAP] && a[RTA_ENCAP_TYPE] && !a[RTA_MULTIPATH])
     {
       switch (rta_get_u16(a[RTA_ENCAP_TYPE]))
 	{
@@ -1944,7 +1982,7 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
 	      struct rtattr *enca[BIRD_RTA_MAX];
 	      nl_attr_len = RTA_PAYLOAD(a[RTA_ENCAP]);
 	      nl_parse_attrs(RTA_DATA(a[RTA_ENCAP]), encap_mpls_want, enca, sizeof(enca));
-	      ra->nh.labels = rta_get_mpls(enca[RTA_DST], ra->nh.label);
+	      nhad.nh.labels = rta_get_mpls(enca[RTA_DST], nhad.nh.label);
 	      break;
 	    }
 	  default:
@@ -1954,6 +1992,9 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
     }
 #endif
 
+  /* Finalize the nexthop */
+  nhad.ad.length = (void *) NEXTHOP_NEXT(&nhad.nh) - (void *) nhad.ad.data;
+
   if (i->rtm_scope != def_scope)
     ea_set_attr(&ra->eattrs,
 	EA_LITERAL_EMBEDDED(&ea_krt_scope, 0, i->rtm_scope));
@@ -1999,6 +2040,10 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
     /* Store the new route */
     s->net = net;
     s->attrs = ra;
+
+    ea_set_attr_data(&ra->eattrs, &ea_gen_nexthop, 0,
+	nhad.ad.data, nhad.ad.length);
+
     s->proto = p;
     s->new = new;
     s->krt_src = krt_src;
@@ -2009,20 +2054,18 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
   else
   {
     /* Merge next hops with the stored route */
-    rta *oa = s->attrs;
+    eattr *nhea = ea_find(s->attrs->eattrs, &ea_gen_nexthop);
+    struct nexthop_adata *nhad_old = nhea ? (struct nexthop_adata *) nhea->u.ptr : NULL;
 
-    struct nexthop *nhs = &oa->nh;
-    nexthop_insert(&nhs, &ra->nh);
-
-    /* Perhaps new nexthop is inserted at the first position */
-    if (nhs == &ra->nh)
-    {
-      /* Swap rtas */
-      s->attrs = ra;
-
-      /* Keep old eattrs */
-      ra->eattrs = oa->eattrs;
-    }
+    if (nhad_old)
+      ea_set_attr(&s->attrs->eattrs,
+	  EA_LITERAL_DIRECT_ADATA(&ea_gen_nexthop, 0, 
+	    &(nexthop_merge(nhad_old, &nhad.nhad,
+		KRT_CF->merge_paths, s->pool)->ad)
+	  ));
+    else
+      ea_set_attr_data(&s->attrs->eattrs, &ea_gen_nexthop, 0,
+	  nhad.ad.data, nhad.ad.length);
   }
 }
 
diff --git a/sysdep/unix/krt.c b/sysdep/unix/krt.c
index b8e7670e..89e9e97e 100644
--- a/sysdep/unix/krt.c
+++ b/sysdep/unix/krt.c
@@ -611,10 +611,14 @@ krt_same_dest(rte *k, rte *e)
   if (ka->dest != ea->dest)
     return 0;
 
-  if (ka->dest == RTD_UNICAST)
-    return nexthop_same(&(ka->nh), &(ea->nh));
+  if (ka->dest != RTD_UNICAST)
+    return 1;
 
-  return 1;
+  eattr *nhea_k = ea_find(ka->eattrs, &ea_gen_nexthop);
+  eattr *nhea_e = ea_find(ea->eattrs, &ea_gen_nexthop);
+
+  ASSUME(nhea_k && nhea_e);
+  return adata_same(nhea_k->u.ptr, nhea_e->u.ptr);
 }
 
 /*