Fix SR multicast post mfib commit

 1 - use the SR policy to construct the replicate DPO. Each bucket therein is a SR tunnel.
 2 - install a special mfib entry that links via this replicate
 3 - forwarding is now mfib-lookup -> replicate -> sr_rewrite (per-tunnel)
        no need for a separate sr_replicate node.
 4 - Stack the sr tunnel on the forwarding DPO of the first-hop FIB entry.
        no need for a second lookup post SR encap.
 5 - fix some path-list lock leaks in the MFIB entry.

Change-Id: I20de96ea4c4be4fae252625bde159d9c435c8315
Signed-off-by: Neale Ranns <nranns@cisco.com>

4 files changed, 235 insertions, 618 deletions

diff --git a/src/vnet/sr/sr.c b/src/vnet/sr/sr.c
index f30c0da940e..012d45428ec 100644
--- a/src/vnet/sr/sr.c
+++ b/src/vnet/sr/sr.c
@@ -23,7 +23,9 @@
 #include <vnet/vnet.h>
 #include <vnet/sr/sr.h>
 #include <vnet/fib/ip6_fib.h>
+#include <vnet/mfib/mfib_table.h>
 #include <vnet/dpo/dpo.h>
+#include <vnet/dpo/replicate_dpo.h>
 
 #include <openssl/hmac.h>
 
@@ -36,6 +38,11 @@ static vlib_node_registration_t sr_local_node;
 static dpo_type_t sr_dpo_type;
 
 /**
+ * @brief Dynamically added SR FIB Node type
+ */
+static fib_node_type_t sr_fib_node_type;
+
+/**
  * @brief Use passed HMAC key in ip6_sr_header_t in OpenSSL HMAC routines
  *
  * @param sm ip6_sr_main_t *
@@ -258,20 +265,10 @@ format_ip6_sr_header_with_length (u8 * s, va_list * args)
 
 /**
  * @brief Defined valid next nodes
- * @note Cannot call replicate yet without DPDK
 */
-#if DPDK > 0
-#define foreach_sr_rewrite_next                 \
-_(ERROR, "error-drop")                          \
-_(IP6_LOOKUP, "ip6-lookup")                     \
-_(SR_LOCAL, "sr-local")                         \
-_(SR_REPLICATE,"sr-replicate")
-#else
 #define foreach_sr_rewrite_next                 \
 _(ERROR, "error-drop")                          \
-_(IP6_LOOKUP, "ip6-lookup")                     \
 _(SR_LOCAL, "sr-local")
-#endif /* DPDK */
 
 /**
  * @brief Struct for defined valid next nodes
@@ -384,8 +381,8 @@ sr_rewrite (vlib_main_t * vm,
 	  ip6_header_t *ip0, *ip1;
 	  ip6_sr_header_t *sr0, *sr1;
 	  ip6_sr_tunnel_t *t0, *t1;
-	  u32 next0 = SR_REWRITE_NEXT_IP6_LOOKUP;
-	  u32 next1 = SR_REWRITE_NEXT_IP6_LOOKUP;
+	  u32 next0;
+	  u32 next1;
 	  u16 new_l0 = 0;
 	  u16 new_l1 = 0;
 
@@ -433,16 +430,6 @@ sr_rewrite (vlib_main_t * vm,
 
 	  ip0 = vlib_buffer_get_current (b0);
 	  ip1 = vlib_buffer_get_current (b1);
-#if DPDK > 0			/* Cannot call replication node yet without DPDK */
-	  /* add a replication node */
-	  if (PREDICT_FALSE (t0->policy_index != ~0))
-	    {
-	      vnet_buffer (b0)->ip.save_protocol = t0->policy_index;
-	      next0 = SR_REWRITE_NEXT_SR_REPLICATE;
-	      sr0 = (ip6_sr_header_t *) (t0->rewrite);
-	      goto processnext;
-	    }
-#endif /* DPDK */
 
 	  /*
 	   * SR-unaware service chaining case: pkt coming back from
@@ -506,8 +493,11 @@ sr_rewrite (vlib_main_t * vm,
 
 	      sr_fix_hmac (sm, ip0, sr0);
 
-	      next0 = sr_local_cb ? sr_local_cb (vm, node, b0, ip0, sr0) :
-		next0;
+	      vnet_buffer (b0)->ip.adj_index[VLIB_TX] =
+		t0->first_hop_dpo.dpoi_index;
+	      next0 = t0->first_hop_dpo.dpoi_next_node;
+	      next0 = (sr_local_cb ?
+		       sr_local_cb (vm, node, b0, ip0, sr0) : next0);
 
 	      /*
 	       * Ignore "do not rewrite" shtik in this path
@@ -519,17 +509,7 @@ sr_rewrite (vlib_main_t * vm,
 		    b0->error = node->errors[SR_REWRITE_ERROR_APP_CALLBACK];
 		}
 	    }
-#if DPDK > 0			/* Cannot call replication node yet without DPDK */
-	processnext:
-	  /* add a replication node */
-	  if (PREDICT_FALSE (t1->policy_index != ~0))
-	    {
-	      vnet_buffer (b1)->ip.save_protocol = t1->policy_index;
-	      next1 = SR_REWRITE_NEXT_SR_REPLICATE;
-	      sr1 = (ip6_sr_header_t *) (t1->rewrite);
-	      goto trace00;
-	    }
-#endif /* DPDK */
+
 	  if (PREDICT_FALSE (ip1->protocol == IPPROTO_IPV6_ROUTE))
 	    {
 	      vlib_buffer_advance (b1, sizeof (ip1));
@@ -584,8 +564,11 @@ sr_rewrite (vlib_main_t * vm,
 
 	      sr_fix_hmac (sm, ip1, sr1);
 
-	      next1 = sr_local_cb ? sr_local_cb (vm, node, b1, ip1, sr1) :
-		next1;
+	      vnet_buffer (b1)->ip.adj_index[VLIB_TX] =
+		t1->first_hop_dpo.dpoi_index;
+	      next1 = t1->first_hop_dpo.dpoi_next_node;
+	      next1 = (sr_local_cb ?
+		       sr_local_cb (vm, node, b1, ip1, sr1) : next1);
 
 	      /*
 	       * Ignore "do not rewrite" shtik in this path
@@ -597,9 +580,6 @@ sr_rewrite (vlib_main_t * vm,
 		    b1->error = node->errors[SR_REWRITE_ERROR_APP_CALLBACK];
 		}
 	    }
-#if DPDK > 0			/* Cannot run replicate without DPDK and only replicate uses this label */
-	trace00:
-#endif /* DPDK */
 
 	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 	    {
@@ -641,7 +621,7 @@ sr_rewrite (vlib_main_t * vm,
 	  ip6_header_t *ip0 = 0;
 	  ip6_sr_header_t *sr0 = 0;
 	  ip6_sr_tunnel_t *t0;
-	  u32 next0 = SR_REWRITE_NEXT_IP6_LOOKUP;
+	  u32 next0;
 	  u16 new_l0 = 0;
 
 	  bi0 = from[0];
@@ -661,16 +641,6 @@ sr_rewrite (vlib_main_t * vm,
 	  t0 =
 	    pool_elt_at_index (sm->tunnels,
 			       vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
-#if DPDK > 0			/* Cannot call replication node yet without DPDK */
-	  /* add a replication node */
-	  if (PREDICT_FALSE (t0->policy_index != ~0))
-	    {
-	      vnet_buffer (b0)->ip.save_protocol = t0->policy_index;
-	      next0 = SR_REWRITE_NEXT_SR_REPLICATE;
-	      sr0 = (ip6_sr_header_t *) (t0->rewrite);
-	      goto trace0;
-	    }
-#endif /* DPDK */
 
 	  ASSERT (VLIB_BUFFER_PRE_DATA_SIZE
 		  >= ((word) vec_len (t0->rewrite)) + b0->current_data);
@@ -740,8 +710,11 @@ sr_rewrite (vlib_main_t * vm,
 
 	      sr_fix_hmac (sm, ip0, sr0);
 
-	      next0 = sr_local_cb ? sr_local_cb (vm, node, b0, ip0, sr0) :
-		next0;
+	      vnet_buffer (b0)->ip.adj_index[VLIB_TX] =
+		t0->first_hop_dpo.dpoi_index;
+	      next0 = t0->first_hop_dpo.dpoi_next_node;
+	      next0 = (sr_local_cb ?
+		       sr_local_cb (vm, node, b0, ip0, sr0) : next0);
 
 	      /*
 	       * Ignore "do not rewrite" shtik in this path
@@ -753,9 +726,6 @@ sr_rewrite (vlib_main_t * vm,
 		    b0->error = node->errors[SR_REWRITE_ERROR_APP_CALLBACK];
 		}
 	    }
-#if DPDK > 0			/* Cannot run replicate without DPDK and only replicate uses this label */
-	trace0:
-#endif /* DPDK */
 
 	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
 	    {
@@ -809,20 +779,69 @@ VLIB_NODE_FUNCTION_MULTIARCH (sr_rewrite_node, sr_rewrite)
 /* *INDENT-ON* */
 
 static int
-ip6_delete_route_no_next_hop (ip6_address_t * dst_address_arg,
-			      u32 dst_address_length, u32 rx_table_id)
+ip6_routes_add_del (ip6_sr_tunnel_t * t, int is_del)
 {
+  ip6_sr_main_t *sm = &sr_main;
+
+  /*
+   * the prefix for the tunnel's destination
+   */
+  /* *INDENT-OFF* */
   fib_prefix_t pfx = {
-    .fp_len = dst_address_length,
     .fp_proto = FIB_PROTOCOL_IP6,
+    .fp_len = t->dst_mask_width,
     .fp_addr = {
-		.ip6 = *dst_address_arg,
-		}
+      .ip6 = t->key.dst,
+    }
   };
+  /* *INDENT-ON* */
 
-  fib_table_entry_delete (fib_table_id_find_fib_index (FIB_PROTOCOL_IP6,
-						       rx_table_id),
-			  &pfx, FIB_SOURCE_SR);
+  if (is_del)
+    {
+      fib_table_entry_delete (t->rx_fib_index, &pfx, FIB_SOURCE_SR);
+    }
+  else
+    {
+      dpo_id_t dpo = DPO_INVALID;
+
+      dpo_set (&dpo, sr_dpo_type, DPO_PROTO_IP6, t - sm->tunnels);
+      fib_table_entry_special_dpo_add (t->rx_fib_index,
+				       &pfx,
+				       FIB_SOURCE_SR,
+				       FIB_ENTRY_FLAG_EXCLUSIVE, &dpo);
+      dpo_reset (&dpo);
+    }
+
+  /*
+   * Track the first hop address so we don't need to perform an extra
+   * lookup in the data-path
+   */
+  /* *INDENT-OFF* */
+  const fib_prefix_t first_hop_pfx = {
+    .fp_len = 128,
+    .fp_proto = FIB_PROTOCOL_IP6,
+    .fp_addr = {
+      .ip6 = t->first_hop,
+    }
+  };
+  /* *INDENT-ON* */
+
+  if (is_del)
+    {
+      fib_entry_child_remove (t->fib_entry_index, t->sibling_index);
+      fib_table_entry_delete_index (t->fib_entry_index, FIB_SOURCE_RR);
+    }
+  else
+    {
+      t->fib_entry_index =
+	fib_table_entry_special_add (t->rx_fib_index,
+				     &first_hop_pfx,
+				     FIB_SOURCE_RR,
+				     FIB_ENTRY_FLAG_NONE, ADJ_INDEX_INVALID);
+      t->sibling_index =
+	fib_entry_child_add (t->fib_entry_index,
+			     sr_fib_node_type, t - sm->tunnels);
+    }
 
   return 0;
 }
@@ -886,6 +905,18 @@ find_or_add_shared_secret (ip6_sr_main_t * sm, u8 * secret, u32 * indexp)
 }
 
 /**
+ * @brief Stack a tunnel on the forwarding chain of the first-hop
+ */
+static void
+sr_tunnel_stack (ip6_sr_tunnel_t * st)
+{
+  dpo_stack (sr_dpo_type,
+	     DPO_PROTO_IP6,
+	     &st->first_hop_dpo,
+	     fib_entry_contribute_ip_forwarding (st->fib_entry_index));
+}
+
+/**
  * @brief Add or Delete a Segment Routing tunnel.
  *
  * @param a ip6_sr_add_del_tunnel_args_t *
@@ -909,7 +940,6 @@ ip6_sr_add_del_tunnel (ip6_sr_add_del_tunnel_args_t * a)
   u8 hmac_key_index = 0;
   ip6_sr_policy_t *pt;
   int i;
-  dpo_id_t dpo = DPO_INVALID;
 
   /* Make sure that the rx FIB exists */
   p = hash_get (im->fib_index_by_table_id, a->rx_table_id);
@@ -981,8 +1011,8 @@ ip6_sr_add_del_tunnel (ip6_sr_add_del_tunnel_args_t * a)
       /* Delete existing tunnel */
       t = pool_elt_at_index (sm->tunnels, p[0]);
 
-      ip6_delete_route_no_next_hop (&t->key.dst, t->dst_mask_width,
-				    a->rx_table_id);
+      ip6_routes_add_del (t, 1);
+
       vec_free (t->rewrite);
       /* Remove tunnel from any policy if associated */
       if (t->policy_index != ~0)
@@ -1014,6 +1044,7 @@ ip6_sr_add_del_tunnel (ip6_sr_add_del_tunnel_args_t * a)
 	  hash_unset_mem (sm->tunnel_index_by_name, t->name);
 	  vec_free (t->name);
 	}
+      dpo_reset (&t->first_hop_dpo);
       pool_put (sm->tunnels, t);
       hp = hash_get_pair (sm->tunnel_index_by_key, &key);
       key_copy = (void *) (hp->key);
@@ -1026,6 +1057,7 @@ ip6_sr_add_del_tunnel (ip6_sr_add_del_tunnel_args_t * a)
   pool_get (sm->tunnels, t);
   memset (t, 0, sizeof (*t));
   t->policy_index = ~0;
+  fib_node_init (&t->node, sr_fib_node_type);
 
   clib_memcpy (&t->key, &key, sizeof (t->key));
   t->dst_mask_width = a->dst_mask_width;
@@ -1124,20 +1156,13 @@ ip6_sr_add_del_tunnel (ip6_sr_add_del_tunnel_args_t * a)
    * We don't handle ugly RFC-related cases yet, but I'm sure PL will complain
    * at some point...
    */
-  dpo_set (&dpo, sr_dpo_type, DPO_PROTO_IP6, t - sm->tunnels);
 
-  fib_prefix_t pfx = {
-    .fp_proto = FIB_PROTOCOL_IP6,
-    .fp_len = a->dst_mask_width,
-    .fp_addr = {
-		.ip6 = *a->dst_address,
-		}
-  };
-  fib_table_entry_special_dpo_add (rx_fib_index,
-				   &pfx,
-				   FIB_SOURCE_SR,
-				   FIB_ENTRY_FLAG_EXCLUSIVE, &dpo);
-  dpo_reset (&dpo);
+  /*
+   * Add the routes for the tunnel destination and first-hop, then stack
+   * the tunnel on the appropriate forwarding DPOs.
+   */
+  ip6_routes_add_del (t, 0);
+  sr_tunnel_stack (t);
 
   if (a->policy_name)
     {
@@ -1197,7 +1222,7 @@ format_sr_dpo (u8 * s, va_list * args)
   return (format (s, "SR: tunnel:[%d]", index));
 }
 
-const static dpo_vft_t sr_vft = {
+const static dpo_vft_t sr_dpo_vft = {
   .dv_lock = sr_dpo_lock,
   .dv_unlock = sr_dpo_unlock,
   .dv_format = format_sr_dpo,
@@ -1212,6 +1237,65 @@ const static char *const *const sr_nodes[DPO_PROTO_NUM] = {
   [DPO_PROTO_IP6] = sr_ip6_nodes,
 };
 
+static ip6_sr_tunnel_t *
+sr_tunnel_from_fib_node (fib_node_t * node)
+{
+#if (CLIB_DEBUG > 0)
+  ASSERT (sr_fib_node_type == node->fn_type);
+#endif
+  return ((ip6_sr_tunnel_t *) (((char *) node) -
+			       STRUCT_OFFSET_OF (ip6_sr_tunnel_t, node)));
+}
+
+/**
+ * Function definition to backwalk a FIB node
+ */
+static fib_node_back_walk_rc_t
+sr_tunnel_back_walk (fib_node_t * node, fib_node_back_walk_ctx_t * ctx)
+{
+  sr_tunnel_stack (sr_tunnel_from_fib_node (node));
+
+  return (FIB_NODE_BACK_WALK_CONTINUE);
+}
+
+/**
+ * Function definition to get a FIB node from its index
+ */
+static fib_node_t *
+sr_tunnel_fib_node_get (fib_node_index_t index)
+{
+  ip6_sr_tunnel_t *st;
+  ip6_sr_main_t *sm;
+
+  sm = &sr_main;
+  st = pool_elt_at_index (sm->tunnels, index);
+
+  return (&st->node);
+}
+
+/**
+ * Function definition to inform the FIB node that its last lock has gone.
+ */
+static void
+sr_tunnel_last_lock_gone (fib_node_t * node)
+{
+  /*
+   * The SR tunnel is a root of the graph. As such
+   * it never has children and thus is never locked.
+   */
+  ASSERT (0);
+}
+
+/*
+ * Virtual function table registered by SR tunnels
+ * for participation in the FIB object graph.
+ */
+const static fib_node_vft_t sr_fib_vft = {
+  .fnv_get = sr_tunnel_fib_node_get,
+  .fnv_last_lock = sr_tunnel_last_lock_gone,
+  .fnv_back_walk = sr_tunnel_back_walk,
+};
+
 /**
  * @brief CLI parser for Add or Delete a Segment Routing tunnel.
  *
@@ -1764,6 +1848,8 @@ ip6_sr_add_del_multicastmap (ip6_sr_add_del_multicastmap_args_t * a)
   ip6_sr_tunnel_t *t;
   ip6_sr_main_t *sm = &sr_main;
   ip6_sr_policy_t *pt;
+  index_t rep;
+  u32 ii;
 
   if (a->is_del)
     {
@@ -1803,23 +1889,49 @@ ip6_sr_add_del_multicastmap (ip6_sr_add_del_multicastmap_args_t * a)
    * We don't handle ugly RFC-related cases yet, but I'm sure PL will complain
    * at some point...
    */
-  dpo_id_t dpo = DPO_INVALID;
-
-  dpo_set (&dpo, sr_dpo_type, DPO_PROTO_IP6, t - sm->tunnels);
 
-  /* Construct a FIB entry for multicast using the rx/tx fib from the first tunnel */
-  fib_prefix_t pfx = {
+  /*
+   * Construct an mFIB entry for the multicast address,
+   * using the rx/tx fib from the first tunnel.
+   * There is no RPF information for this address (I need to discuss this with
+   * Pablo), so for now accept from anywhere...
+   */
+  /* *INDENT-OFF* */
+  mfib_prefix_t pfx = {
     .fp_proto = FIB_PROTOCOL_IP6,
     .fp_len = 128,
-    .fp_addr = {
-		.ip6 = *a->multicast_address,
-		}
+    .fp_grp_addr = {
+      .ip6 = *a->multicast_address,
+    }
   };
-  fib_table_entry_special_dpo_add (t->rx_fib_index,
-				   &pfx,
-				   FIB_SOURCE_SR,
-				   FIB_ENTRY_FLAG_EXCLUSIVE, &dpo);
-  dpo_reset (&dpo);
+  /* *INDENT-ON* */
+
+  if (a->is_del)
+    mfib_table_entry_delete (t->rx_fib_index, &pfx, MFIB_SOURCE_SRv6);
+  else
+    {
+      /*
+       * Construct a replicate DPO that will replicate received packets over
+       * each tunnel in the policy
+       */
+      dpo_id_t dpo = DPO_INVALID;
+
+      rep = replicate_create (vec_len (pt->tunnel_indices), DPO_PROTO_IP6);
+
+      vec_foreach_index (ii, pt->tunnel_indices)
+      {
+	dpo_set (&dpo, sr_dpo_type, DPO_PROTO_IP6, pt->tunnel_indices[ii]);
+
+	replicate_set_bucket (rep, ii, &dpo);
+      }
+
+      mfib_table_entry_special_add (t->rx_fib_index,
+				    &pfx,
+				    MFIB_SOURCE_SRv6,
+				    MFIB_ENTRY_FLAG_ACCEPT_ALL_ITF, rep);
+
+      dpo_reset (&dpo);
+    }
 
   u8 *mcast_copy = 0;
   mcast_copy = vec_new (ip6_address_t, 1);
@@ -1829,13 +1941,12 @@ ip6_sr_add_del_multicastmap (ip6_sr_add_del_multicastmap_args_t * a)
     {
       hash_unset_mem (sm->policy_index_by_multicast_address, mcast_copy);
       vec_free (mcast_copy);
-      return 0;
     }
-  /* else */
-
-  hash_set_mem (sm->policy_index_by_multicast_address, mcast_copy,
-		pt - sm->policies);
-
+  else
+    {
+      hash_set_mem (sm->policy_index_by_multicast_address, mcast_copy,
+		    pt - sm->policies);
+    }
 
   return 0;
 }
@@ -1888,12 +1999,7 @@ sr_add_del_multicast_map_command_fn (vlib_main_t * vm,
   a->multicast_address = &multicast_address;
   a->policy_name = policy_name;
 
-#if DPDK > 0			/*Cannot call replicate or configure multicast map yet without DPDK */
   rv = ip6_sr_add_del_multicastmap (a);
-#else
-  return clib_error_return (0,
-			    "cannot use multicast replicate spray case without DPDK installed");
-#endif /* DPDK */
 
   switch (rv)
     {
@@ -2295,12 +2401,6 @@ sr_init (vlib_main_t * vm)
   ip6_rewrite_node = vlib_get_node_by_name (vm, (u8 *) "ip6-rewrite");
   ASSERT (ip6_rewrite_node);
 
-#if DPDK > 0			/* Cannot run replicate without DPDK */
-  /* Add a disposition to sr_replicate for the sr multicast replicate node */
-  sm->ip6_lookup_sr_replicate_index =
-    vlib_node_add_next (vm, ip6_lookup_node->index, sr_replicate_node.index);
-#endif /* DPDK */
-
   /* Add a disposition to ip6_rewrite for the sr dst address hack node */
   sm->ip6_rewrite_sr_next_index =
     vlib_node_add_next (vm, ip6_rewrite_node->index,
@@ -2311,7 +2411,8 @@ sr_init (vlib_main_t * vm)
   sm->md = (void *) EVP_get_digestbyname ("sha1");
   sm->hmac_ctx = clib_mem_alloc (sizeof (HMAC_CTX));
 
-  sr_dpo_type = dpo_register_new_type (&sr_vft, sr_nodes);
+  sr_dpo_type = dpo_register_new_type (&sr_dpo_vft, sr_nodes);
+  sr_fib_node_type = fib_node_register_new_type (&sr_fib_vft);
 
   return error;
 }
@@ -3087,7 +3188,7 @@ set_ip6_sr_rewrite_fn (vlib_main_t * vm,
   hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
   adj->rewrite_header.node_index = sr_fix_dst_addr_node.index;
 
-  /* $$$$$ hack... steal the mcast group index */
+  /* $$$$$ hack... steal the interface address index */
   adj->if_address_index =
     vlib_node_add_next (vm, sr_fix_dst_addr_node.index,
 			hi->output_node_index);
diff --git a/src/vnet/sr/sr.h b/src/vnet/sr/sr.h
index 610b36996f3..3c50b7358a1 100644
--- a/src/vnet/sr/sr.h
+++ b/src/vnet/sr/sr.h
@@ -15,8 +15,6 @@
 /**
  * @file
  * @brief Segment Routing header
- *
- * @note sr_replicate only works using DPDK today
  */
 #ifndef included_vnet_sr_h
 #define included_vnet_sr_h
@@ -71,6 +69,27 @@ typedef struct
   /** Indicates that this tunnel is part of a policy comprising
      of multiple tunnels. If == ~0 tunnel is not part of a policy */
   u32 policy_index;
+
+  /**
+   * The FIB node graph linkage
+   */
+  fib_node_t node;
+
+  /**
+   * The FIB entry index for the first hop. We track this so we
+   * don't need an extra lookup for it in the data plane
+   */
+  fib_node_index_t fib_entry_index;
+
+  /**
+   * This tunnel's sibling index in the children of the FIB entry
+   */
+  u32 sibling_index;
+
+  /**
+   * The DPO contributed by the first-hop FIB entry.
+   */
+  dpo_id_t first_hop_dpo;
 } ip6_sr_tunnel_t;
 
 /**
@@ -205,9 +224,6 @@ typedef struct
   /** ip6-rewrite next index for reinstalling the original dst address */
   u32 ip6_rewrite_sr_next_index;
 
-  /** ip6-replicate next index for multicast tunnel */
-  u32 ip6_lookup_sr_replicate_index;
-
   /** application API callback */
   void *sr_local_cb;
 
@@ -238,10 +254,6 @@ format_function_t format_ip6_sr_header_with_length;
 
 vlib_node_registration_t ip6_sr_input_node;
 
-#if DPDK > 0
-extern vlib_node_registration_t sr_replicate_node;
-#endif /* DPDK */
-
 int ip6_sr_add_del_tunnel (ip6_sr_add_del_tunnel_args_t * a);
 int ip6_sr_add_del_policy (ip6_sr_add_del_policy_args_t * a);
 int ip6_sr_add_del_multicastmap (ip6_sr_add_del_multicastmap_args_t * a);
diff --git a/src/vnet/sr/sr_api.c b/src/vnet/sr/sr_api.c
index 6c6eb9b6449..bab0fc84aba 100644
--- a/src/vnet/sr/sr_api.c
+++ b/src/vnet/sr/sr_api.c
@@ -190,12 +190,7 @@ static void vl_api_sr_multicast_map_add_del_t_handler
       goto out;
     }
 
-#if DPDK > 0			/* Cannot call replicate without DPDK */
   rv = ip6_sr_add_del_multicastmap (a);
-#else
-  clib_warning ("multicast replication without DPDK not implemented");
-  rv = VNET_API_ERROR_UNIMPLEMENTED;
-#endif /* DPDK */
 
 out:
 
diff --git a/src/vnet/sr/sr_replicate.c b/src/vnet/sr/sr_replicate.c
deleted file mode 100644
index fa5a68c31c2..00000000000
--- a/src/vnet/sr/sr_replicate.c
+++ /dev/null
@@ -1,491 +0,0 @@
-/*
- * sr_replicate.c: ipv6 segment routing replicator for multicast
- *
- * Copyright (c) 2016 Cisco and/or its affiliates.
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-/**
- *  @file
- *  @brief Functions for replicating packets across SR tunnels.
- *
- *  Leverages rte_pktmbuf_clone() so there is no memcpy for
- *  invariant parts of the packet.
- *
- *  @note Currently requires DPDK
-*/
-
-#if DPDK > 0			/* Cannot run replicate without DPDK */
-#include <vlib/vlib.h>
-#include <vnet/vnet.h>
-#include <vnet/pg/pg.h>
-#include <vnet/sr/sr.h>
-#include <vnet/devices/dpdk/dpdk.h>
-#include <vnet/devices/dpdk/dpdk_priv.h>
-#include <vnet/ip/ip.h>
-#include <vnet/fib/ip6_fib.h>
-
-#include <vppinfra/hash.h>
-#include <vppinfra/error.h>
-#include <vppinfra/elog.h>
-
-/**
- *   @brief sr_replicate state.
- *
-*/
-typedef struct
-{
-  /* convenience */
-  vlib_main_t *vlib_main;
-  vnet_main_t *vnet_main;
-} sr_replicate_main_t;
-
-sr_replicate_main_t sr_replicate_main;
-
-/**
- *    @brief Information to display in packet trace.
- *
-*/
-typedef struct
-{
-  ip6_address_t src, dst;
-  u16 length;
-  u32 next_index;
-  u32 tunnel_index;
-  u8 sr[256];
-} sr_replicate_trace_t;
-
-/**
- *  @brief packet trace format function.
- *
- *  @param *s u8 used for string output
- *  @param *args va_list  structured input to va_arg to output @ref sr_replicate_trace_t
- *  @return *s u8 - formatted trace output
-*/
-static u8 *
-format_sr_replicate_trace (u8 * s, va_list * args)
-{
-  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
-  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
-  sr_replicate_trace_t *t = va_arg (*args, sr_replicate_trace_t *);
-  ip6_sr_main_t *sm = &sr_main;
-  ip6_sr_tunnel_t *tun = pool_elt_at_index (sm->tunnels, t->tunnel_index);
-  ip6_fib_t *rx_fib, *tx_fib;
-
-  rx_fib = ip6_fib_get (tun->rx_fib_index);
-  tx_fib = ip6_fib_get (tun->tx_fib_index);
-
-  s = format
-    (s, "SR-REPLICATE: next %s ip6 src %U dst %U len %u\n"
-     "           rx-fib-id %d tx-fib-id %d\n%U",
-     "ip6-lookup",
-     format_ip6_address, &t->src,
-     format_ip6_address, &t->dst, t->length,
-     rx_fib->table_id, tx_fib->table_id,
-     format_ip6_sr_header, t->sr, 0 /* print_hmac */ );
-  return s;
-
-}
-
-#define foreach_sr_replicate_error \
-_(REPLICATED, "sr packets replicated") \
-_(NO_BUFFERS, "error allocating buffers for replicas") \
-_(NO_REPLICAS, "no replicas were needed") \
-_(NO_BUFFER_DROPS, "sr no buffer drops")
-
-/**
- * @brief Struct for SR replicate errors
- */
-typedef enum
-{
-#define _(sym,str) SR_REPLICATE_ERROR_##sym,
-  foreach_sr_replicate_error
-#undef _
-    SR_REPLICATE_N_ERROR,
-} sr_replicate_error_t;
-
-/**
- * @brief Error strings for SR replicate
- */
-static char *sr_replicate_error_strings[] = {
-#define _(sym,string) string,
-  foreach_sr_replicate_error
-#undef _
-};
-
-/**
- * @brief Defines next-nodes for packet processing.
- *
-*/
-typedef enum
-{
-  SR_REPLICATE_NEXT_IP6_LOOKUP,
-  SR_REPLICATE_N_NEXT,
-} sr_replicate_next_t;
-
-/**
- *   @brief Single loop packet replicator.
- *
- *   @node sr-replicate
- *   @param vm vlib_main_t
- *   @return frame->n_vectors uword
-*/
-static uword
-sr_replicate_node_fn (vlib_main_t * vm,
-		      vlib_node_runtime_t * node, vlib_frame_t * frame)
-{
-  dpdk_main_t *dm = &dpdk_main;
-  u32 n_left_from, *from, *to_next;
-  sr_replicate_next_t next_index;
-  int pkts_replicated = 0;
-  ip6_sr_main_t *sm = &sr_main;
-  int no_buffer_drops = 0;
-  vlib_buffer_free_list_t *fl;
-  unsigned socket_id = rte_socket_id ();
-
-  from = vlib_frame_vector_args (frame);
-  n_left_from = frame->n_vectors;
-  next_index = node->cached_next_index;
-
-  fl = vlib_buffer_get_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
-
-  while (n_left_from > 0)
-    {
-      u32 n_left_to_next;
-
-      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
-
-      while (n_left_from > 0 && n_left_to_next > 0)
-	{
-	  u32 bi0, hdr_bi0;
-	  vlib_buffer_t *b0, *orig_b0;
-	  struct rte_mbuf *orig_mb0 = 0, *hdr_mb0 = 0, *clone0 = 0;
-	  struct rte_mbuf **hdr_vec = 0, **rte_mbuf_vec = 0;
-	  ip6_sr_policy_t *pol0 = 0;
-	  ip6_sr_tunnel_t *t0 = 0;
-	  ip6_sr_header_t *hdr_sr0 = 0;
-	  ip6_header_t *ip0 = 0, *hdr_ip0 = 0;
-	  int num_replicas = 0;
-	  int i;
-	  u32 len_bytes = sizeof (ip6_header_t);
-	  u8 next_hdr, ip_next_hdr = IPPROTO_IPV6_ROUTE;
-
-	  bi0 = from[0];
-
-	  b0 = vlib_get_buffer (vm, bi0);
-	  orig_b0 = b0;
-
-	  pol0 = pool_elt_at_index (sm->policies,
-				    vnet_buffer (b0)->ip.save_protocol);
-
-	  ip0 = vlib_buffer_get_current (b0);
-	  /* Skip forward to the punch-in point */
-	  vlib_buffer_advance (b0, sizeof (*ip0));
-	  next_hdr = ip0->protocol;
-
-	  /* HBH must immediately follow ipv6 header */
-	  if (PREDICT_FALSE
-	      (ip0->protocol == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS))
-	    {
-	      ip6_hop_by_hop_ext_t *ext_hdr =
-		(ip6_hop_by_hop_ext_t *) ip6_next_header (ip0);
-	      u32 ext_hdr_len = 0;
-	      ext_hdr_len = ip6_ext_header_len ((ip6_ext_header_t *) ext_hdr);
-	      len_bytes += ext_hdr_len;
-	      next_hdr = ext_hdr->next_hdr;
-	      ext_hdr->next_hdr = IPPROTO_IPV6_ROUTE;
-	      ip_next_hdr = IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS;
-	      /* Skip forward to the punch-in point */
-	      vlib_buffer_advance (b0, ext_hdr_len);
-
-	    }
-
-	  orig_mb0 = rte_mbuf_from_vlib_buffer (b0);
-
-	  i16 delta0 = vlib_buffer_length_in_chain (vm, orig_b0)
-	    - (i16) orig_mb0->pkt_len;
-
-	  u16 new_data_len0 = (u16) ((i16) orig_mb0->data_len + delta0);
-	  u16 new_pkt_len0 = (u16) ((i16) orig_mb0->pkt_len + delta0);
-
-	  orig_mb0->data_len = new_data_len0;
-	  orig_mb0->pkt_len = new_pkt_len0;
-	  orig_mb0->data_off += (u16) (b0->current_data);
-
-	  /*
-	     Before entering loop determine if we can allocate:
-	     - all the new HEADER RTE_MBUFs and assign them to a vector
-	     - all the clones
-
-	     if successful, then iterate over vectors of resources
-
-	   */
-	  num_replicas = vec_len (pol0->tunnel_indices);
-
-	  if (PREDICT_FALSE (num_replicas == 0))
-	    {
-	      b0->error = node->errors[SR_REPLICATE_ERROR_NO_REPLICAS];
-	      goto do_trace0;
-	    }
-
-	  vec_reset_length (hdr_vec);
-	  vec_reset_length (rte_mbuf_vec);
-
-	  for (i = 0; i < num_replicas; i++)
-	    {
-	      uint8_t nb_seg;
-	      struct rte_mbuf *clone0i;
-	      vlib_buffer_t *clone0_c, *clone_b0;
-
-	      t0 = vec_elt_at_index (sm->tunnels, pol0->tunnel_indices[i]);
-	      hdr_mb0 = rte_pktmbuf_alloc (dm->pktmbuf_pools[socket_id]);
-
-	      if (i < (num_replicas - 1))
-		{
-		  /* Not the last tunnel to process */
-		  clone0 = rte_pktmbuf_clone
-		    (orig_mb0, dm->pktmbuf_pools[socket_id]);
-		  if (clone0 == 0)
-		    goto clone_fail;
-		  nb_seg = 0;
-		  clone0i = clone0;
-		  clone0_c = NULL;
-		  while ((clone0->nb_segs >= 1) && (nb_seg < clone0->nb_segs))
-		    {
-
-		      clone_b0 = vlib_buffer_from_rte_mbuf (clone0i);
-		      vlib_buffer_init_for_free_list (clone_b0, fl);
-
-		      ASSERT ((clone_b0->flags & VLIB_BUFFER_NEXT_PRESENT) ==
-			      0);
-		      ASSERT (clone_b0->current_data == 0);
-
-		      clone_b0->current_data =
-			(clone0i->buf_addr + clone0i->data_off) -
-			(void *) clone_b0->data;
-
-		      clone_b0->current_length = clone0i->data_len;
-		      if (PREDICT_FALSE (clone0_c != NULL))
-			{
-			  clone0_c->flags |= VLIB_BUFFER_NEXT_PRESENT;
-			  clone0_c->next_buffer =
-			    vlib_get_buffer_index (vm, clone_b0);
-			}
-		      clone0_c = clone_b0;
-		      clone0i = clone0i->next;
-		      nb_seg++;
-		    }
-		}
-	      else
-		/* First tunnel to process, use original MB */
-		clone0 = orig_mb0;
-
-
-	      if (PREDICT_FALSE (!clone0 || !hdr_mb0))
-		{
-		clone_fail:
-		  b0->error = node->errors[SR_REPLICATE_ERROR_NO_BUFFERS];
-
-		  vec_foreach_index (i, rte_mbuf_vec)
-		  {
-		    rte_pktmbuf_free (rte_mbuf_vec[i]);
-		  }
-		  vec_free (rte_mbuf_vec);
-
-		  vec_foreach_index (i, hdr_vec)
-		  {
-		    rte_pktmbuf_free (hdr_vec[i]);
-		  }
-		  vec_free (hdr_vec);
-
-		  goto do_trace0;
-		}
-
-	      vec_add1 (hdr_vec, hdr_mb0);
-	      vec_add1 (rte_mbuf_vec, clone0);
-
-	    }
-
-	  for (i = 0; i < num_replicas; i++)
-	    {
-	      vlib_buffer_t *hdr_b0;
-	      u16 new_l0 = 0;
-
-	      t0 = vec_elt_at_index (sm->tunnels, pol0->tunnel_indices[i]);
-	      /* Our replicas */
-	      hdr_mb0 = hdr_vec[i];
-	      clone0 = rte_mbuf_vec[i];
-
-	      hdr_mb0->data_len = len_bytes + vec_len (t0->rewrite);
-	      hdr_mb0->pkt_len = hdr_mb0->data_len +
-		vlib_buffer_length_in_chain (vm, orig_b0);
-
-	      hdr_b0 = vlib_buffer_from_rte_mbuf (hdr_mb0);
-
-	      vlib_buffer_init_for_free_list (hdr_b0, fl);
-
-	      memcpy (hdr_b0->data, ip0, len_bytes);
-	      memcpy (hdr_b0->data + len_bytes, t0->rewrite,
-		      vec_len (t0->rewrite));
-
-	      hdr_b0->current_data = 0;
-	      hdr_b0->current_length = len_bytes + vec_len (t0->rewrite);
-	      hdr_b0->flags = orig_b0->flags | VLIB_BUFFER_NEXT_PRESENT;
-	      hdr_b0->trace_index = orig_b0->trace_index;
-	      vnet_buffer (hdr_b0)->l2_classify.opaque_index = 0;
-
-	      hdr_b0->total_length_not_including_first_buffer =
-		hdr_mb0->pkt_len - hdr_b0->current_length;
-	      vnet_buffer (hdr_b0)->sw_if_index[VLIB_TX] = t0->tx_fib_index;
-
-	      hdr_ip0 = (ip6_header_t *) hdr_b0->data;
-	      new_l0 = clib_net_to_host_u16 (ip0->payload_length) +
-		vec_len (t0->rewrite);
-	      hdr_ip0->payload_length = clib_host_to_net_u16 (new_l0);
-	      hdr_sr0 = (ip6_sr_header_t *) ((u8 *) hdr_ip0 + len_bytes);
-	      /* $$$ tune */
-	      clib_memcpy (hdr_sr0, t0->rewrite, vec_len (t0->rewrite));
-	      hdr_sr0->protocol = next_hdr;
-	      hdr_ip0->protocol = ip_next_hdr;
-
-	      /* Copy dst address into the DA slot in the segment list */
-	      clib_memcpy (hdr_sr0->segments, ip0->dst_address.as_u64,
-			   sizeof (ip6_address_t));
-
-	      /* Rewrite the ip6 dst address */
-	      hdr_ip0->dst_address.as_u64[0] = t0->first_hop.as_u64[0];
-	      hdr_ip0->dst_address.as_u64[1] = t0->first_hop.as_u64[1];
-
-	      sr_fix_hmac (sm, hdr_ip0, hdr_sr0);
-
-	      /* prepend new header to invariant piece */
-	      hdr_mb0->next = clone0;
-	      hdr_b0->next_buffer =
-		vlib_get_buffer_index (vm,
-				       vlib_buffer_from_rte_mbuf (clone0));
-
-	      /* update header's fields */
-	      hdr_mb0->pkt_len =
-		(uint16_t) (hdr_mb0->data_len + clone0->pkt_len);
-	      hdr_mb0->nb_segs = (uint8_t) (clone0->nb_segs + 1);
-
-	      /* copy metadata from source packet */
-	      hdr_mb0->port = clone0->port;
-	      hdr_mb0->vlan_tci = clone0->vlan_tci;
-	      hdr_mb0->vlan_tci_outer = clone0->vlan_tci_outer;
-	      hdr_mb0->tx_offload = clone0->tx_offload;
-	      hdr_mb0->hash = clone0->hash;
-
-	      hdr_mb0->ol_flags = clone0->ol_flags & ~(IND_ATTACHED_MBUF);
-
-	      __rte_mbuf_sanity_check (hdr_mb0, 1);
-
-	      hdr_bi0 = vlib_get_buffer_index (vm, hdr_b0);
-
-	      to_next[0] = hdr_bi0;
-	      to_next += 1;
-	      n_left_to_next -= 1;
-
-	      if (n_left_to_next == 0)
-		{
-		  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
-		  vlib_get_next_frame (vm, node, next_index,
-				       to_next, n_left_to_next);
-
-		}
-	      pkts_replicated++;
-	    }
-
-	  from += 1;
-	  n_left_from -= 1;
-
-	do_trace0:
-	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
-	    {
-	      sr_replicate_trace_t *tr = vlib_add_trace (vm, node,
-							 b0, sizeof (*tr));
-	      tr->tunnel_index = t0 - sm->tunnels;
-	      tr->length = 0;
-	      if (hdr_ip0)
-		{
-		  memcpy (tr->src.as_u8, hdr_ip0->src_address.as_u8,
-			  sizeof (tr->src.as_u8));
-		  memcpy (tr->dst.as_u8, hdr_ip0->dst_address.as_u8,
-			  sizeof (tr->dst.as_u8));
-		  if (hdr_ip0->payload_length)
-		    tr->length = clib_net_to_host_u16
-		      (hdr_ip0->payload_length);
-		}
-	      tr->next_index = next_index;
-	      if (hdr_sr0)
-		memcpy (tr->sr, hdr_sr0, sizeof (tr->sr));
-	    }
-
-	}
-
-      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
-    }
-
-  vlib_node_increment_counter (vm, sr_replicate_node.index,
-			       SR_REPLICATE_ERROR_REPLICATED,
-			       pkts_replicated);
-
-  vlib_node_increment_counter (vm, sr_replicate_node.index,
-			       SR_REPLICATE_ERROR_NO_BUFFER_DROPS,
-			       no_buffer_drops);
-
-  return frame->n_vectors;
-}
-
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (sr_replicate_node) = {
-  .function = sr_replicate_node_fn,
-  .name = "sr-replicate",
-  .vector_size = sizeof (u32),
-  .format_trace = format_sr_replicate_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
-
-  .n_errors = ARRAY_LEN(sr_replicate_error_strings),
-  .error_strings = sr_replicate_error_strings,
-
-  .n_next_nodes = SR_REPLICATE_N_NEXT,
-
-  .next_nodes = {
-        [SR_REPLICATE_NEXT_IP6_LOOKUP] = "ip6-lookup",
-  },
-};
-
-VLIB_NODE_FUNCTION_MULTIARCH (sr_replicate_node, sr_replicate_node_fn)
-/* *INDENT-ON* */
-
-clib_error_t *
-sr_replicate_init (vlib_main_t * vm)
-{
-  sr_replicate_main_t *msm = &sr_replicate_main;
-
-  msm->vlib_main = vm;
-  msm->vnet_main = vnet_get_main ();
-
-  return 0;
-}
-
-VLIB_INIT_FUNCTION (sr_replicate_init);
-
-#endif /* DPDK */
-
-/*
- * fd.io coding-style-patch-verification: ON
- *
- * Local Variables:
- * eval: (c-set-style "gnu")
- * End:
- */