arping: add arping command

Add linux similar arping command to VPP.
syntax: arping [gratuitous] <address> <interface> [repeat <count>] [interval <secs>]

Type: feature

Signed-off-by: Steven Luong <sluong@cisco.com>
Change-Id: I9267c054235207b8fae8e3f159246777eb0340dd

1 files changed, 797 insertions, 0 deletions

diff --git a/src/plugins/arping/arping.c b/src/plugins/arping/arping.c
new file mode 100644
index 00000000000..6c5836b9b9b
--- /dev/null
+++ b/src/plugins/arping/arping.c
@@ -0,0 +1,797 @@
+/*
+ * Copyright (c) 2021 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.
+ */
+
+#include <stddef.h>
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <vnet/plugin/plugin.h>
+#include <vpp/app/version.h>
+#include <vnet/ip-neighbor/ip4_neighbor.h>
+#include <vnet/ip-neighbor/ip6_neighbor.h>
+#include <arping/arping.h>
+
+arping_main_t arping_main;
+
+#define foreach_arping_error _ (NONE, "no error")
+
+typedef enum
+{
+#define _(f, s) ARPING_ERROR_##f,
+  foreach_arping_error
+#undef _
+    ARPING_N_ERROR,
+} arping__error_t;
+
+static char *arping_error_strings[] = {
+#define _(n, s) s,
+  foreach_arping_error
+#undef _
+};
+
+#define foreach_arping                                                        \
+  _ (DROP, "error-drop")                                                      \
+  _ (IO, "interface-output")
+
+typedef enum
+{
+#define _(sym, str) ARPING_NEXT_##sym,
+  foreach_arping
+#undef _
+    ARPING_N_NEXT,
+} arping_next_t;
+
+typedef struct arping_trace_t_
+{
+  u32 sw_if_index;
+  u16 arp_opcode;
+  ethernet_arp_ip4_over_ethernet_address_t reply;
+} arping_trace_t;
+
+typedef enum
+{
+#define _(sym, str) ARPING6_NEXT_##sym,
+  foreach_arping
+#undef _
+    ARPING6_N_NEXT,
+} arping6_next_t;
+
+typedef CLIB_PACKED (struct {
+  mac_address_t mac;
+  ip6_address_t ip6;
+}) ethernet_arp_ip6_over_ethernet_address_t;
+
+typedef struct arping6_trace_t_
+{
+  u32 sw_if_index;
+  u8 type;
+  ethernet_arp_ip6_over_ethernet_address_t reply;
+} arping6_trace_t;
+
+/* packet trace format function */
+static u8 *
+format_arping_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 *);
+  arping_trace_t *t = va_arg (*args, arping_trace_t *);
+
+  s = format (s, "sw-if-index: %u, opcode: %U, from %U (%U)", t->sw_if_index,
+	      format_ethernet_arp_opcode, t->arp_opcode, format_mac_address,
+	      &t->reply.mac, format_ip4_address, &t->reply.ip4);
+
+  return s;
+}
+
+static u8 *
+format_arping6_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 *);
+  arping6_trace_t *t = va_arg (*args, arping6_trace_t *);
+
+  s = format (s, "sw-if-index: %u, type: %u, from %U (%U)", t->sw_if_index,
+	      t->type, format_mac_address, &t->reply.mac, format_ip6_address,
+	      &t->reply.ip6);
+
+  return s;
+}
+
+VLIB_NODE_FN (arping_input_node)
+(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
+{
+  u32 n_left_from, *from, *to_next, n_left_to_next;
+  arping_next_t next_index;
+  arping_main_t *am = &arping_main;
+
+  next_index = node->cached_next_index;
+  n_left_from = frame->n_vectors;
+  from = vlib_frame_vector_args (frame);
+
+  while (n_left_from > 0)
+    {
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from >= 2 && n_left_to_next >= 2)
+	{
+	  u32 next0, next1, bi0, bi1;
+	  vlib_buffer_t *b0, *b1;
+	  ethernet_arp_header_t *arp0, *arp1;
+	  u32 sw_if_index0, sw_if_index1;
+	  arping_intf_t *aif0, *aif1;
+
+	  bi0 = to_next[0] = from[0];
+	  bi1 = to_next[1] = from[1];
+
+	  from += 2;
+	  n_left_from -= 2;
+	  to_next += 2;
+	  n_left_to_next -= 2;
+
+	  next0 = next1 = ARPING_NEXT_DROP;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+	  arp0 = vlib_buffer_get_current (b0);
+	  arp1 = vlib_buffer_get_current (b1);
+
+	  vnet_feature_next (&next0, b0);
+	  vnet_feature_next (&next1, b1);
+
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	  sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
+
+	  if (PREDICT_TRUE (arp0->opcode ==
+			    clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply)))
+	    {
+	      aif0 = am->interfaces[sw_if_index0];
+	      if (PREDICT_TRUE (aif0->address.ip.ip4.as_u32 ==
+				arp0->ip4_over_ethernet[0].ip4.as_u32))
+		{
+		  aif0->recv.from4.ip4.as_u32 =
+		    arp0->ip4_over_ethernet[0].ip4.as_u32;
+		  clib_memcpy_fast (&aif0->recv.from4.mac,
+				    &arp0->ip4_over_ethernet[0].mac, 6);
+		  aif0->reply_count++;
+		}
+	    }
+	  if (PREDICT_TRUE (arp1->opcode ==
+			    clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply)))
+	    {
+	      aif1 = am->interfaces[sw_if_index1];
+	      if (PREDICT_TRUE (aif1->address.ip.ip4.as_u32 ==
+				arp1->ip4_over_ethernet[0].ip4.as_u32))
+		{
+		  aif1->recv.from4.ip4.as_u32 =
+		    arp1->ip4_over_ethernet[0].ip4.as_u32;
+		  clib_memcpy_fast (&aif1->recv.from4.mac,
+				    &arp0->ip4_over_ethernet[0].mac, 6);
+		  aif1->reply_count++;
+		}
+	    }
+
+	  if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      arping_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	      t->arp_opcode = clib_host_to_net_u16 (arp0->opcode);
+	      t->reply.ip4.as_u32 = arp0->ip4_over_ethernet[0].ip4.as_u32;
+	      clib_memcpy_fast (&t->reply.mac, &arp0->ip4_over_ethernet[0].mac,
+				6);
+	    }
+	  if (PREDICT_FALSE ((b1->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      arping_trace_t *t = vlib_add_trace (vm, node, b1, sizeof (*t));
+	      t->sw_if_index = vnet_buffer (b1)->sw_if_index[VLIB_RX];
+	      t->arp_opcode = clib_host_to_net_u16 (arp1->opcode);
+	      t->reply.ip4.as_u32 = arp1->ip4_over_ethernet[0].ip4.as_u32;
+	      clib_memcpy_fast (&t->reply.mac, &arp1->ip4_over_ethernet[0].mac,
+				6);
+	    }
+
+	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index, to_next,
+					   n_left_to_next, bi0, bi1, next0,
+					   next1);
+	}
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 next0, bi0;
+	  vlib_buffer_t *b0;
+	  ethernet_arp_header_t *arp0;
+	  arping_intf_t *aif0;
+	  u32 sw_if_index0;
+
+	  bi0 = to_next[0] = from[0];
+
+	  from += 1;
+	  n_left_from -= 1;
+	  to_next += 1;
+	  n_left_to_next -= 1;
+	  next0 = ARPING_NEXT_DROP;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  arp0 = vlib_buffer_get_current (b0);
+
+	  vnet_feature_next (&next0, b0);
+
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+
+	  if (PREDICT_TRUE (arp0->opcode ==
+			    clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply)))
+	    {
+	      aif0 = am->interfaces[sw_if_index0];
+	      if (PREDICT_TRUE (aif0->address.ip.ip4.as_u32 ==
+				arp0->ip4_over_ethernet[0].ip4.as_u32))
+		{
+		  aif0->recv.from4.ip4.as_u32 =
+		    arp0->ip4_over_ethernet[0].ip4.as_u32;
+		  clib_memcpy_fast (&aif0->recv.from4.mac,
+				    &arp0->ip4_over_ethernet[0].mac, 6);
+		  aif0->reply_count++;
+		}
+	    }
+
+	  if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      arping_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	      t->arp_opcode = clib_host_to_net_u16 (arp0->opcode);
+	      t->reply.ip4.as_u32 = arp0->ip4_over_ethernet[0].ip4.as_u32;
+	      clib_memcpy_fast (&t->reply.mac, &arp0->ip4_over_ethernet[0].mac,
+				6);
+	    }
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  return frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (arping_input_node) =
+{
+  .name = "arping-input",.vector_size = sizeof (u32),.format_trace =
+    format_arping_trace,.type = VLIB_NODE_TYPE_INTERNAL,.n_errors =
+    ARPING_N_ERROR,.error_strings = arping_error_strings,.n_next_nodes =
+    ARPING_N_NEXT,.next_nodes =
+  {
+  [ARPING_NEXT_DROP] = "error-drop",[ARPING_NEXT_IO] = "interface-output",}
+,};
+
+VNET_FEATURE_INIT (arping_feat_node, static) = {
+  .arc_name = "arp",
+  .node_name = "arping-input",
+  .runs_before = VNET_FEATURES ("arp-reply"),
+};
+
+VLIB_NODE_FN (arping6_input_node)
+(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
+{
+  u32 n_left_from, *from, *to_next, n_left_to_next;
+  arping_next_t next_index;
+  arping_main_t *am = &arping_main;
+
+  next_index = node->cached_next_index;
+  n_left_from = frame->n_vectors;
+  from = vlib_frame_vector_args (frame);
+
+  while (n_left_from > 0)
+    {
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from >= 2 && n_left_to_next >= 2)
+	{
+	  u32 next0, next1, bi0, bi1;
+	  vlib_buffer_t *b0, *b1;
+	  ip6_header_t *ip60, *ip61;
+	  u32 sw_if_index0, sw_if_index1;
+	  arping_intf_t *aif0, *aif1;
+	  icmp6_neighbor_solicitation_or_advertisement_header_t *sol_adv0,
+	    *sol_adv1;
+	  icmp6_neighbor_discovery_ethernet_link_layer_address_option_t
+	    *lladdr0,
+	    *lladdr1;
+
+	  bi0 = to_next[0] = from[0];
+	  bi1 = to_next[1] = from[1];
+
+	  from += 2;
+	  n_left_from -= 2;
+	  to_next += 2;
+	  n_left_to_next -= 2;
+
+	  next0 = next1 = ARPING6_NEXT_DROP;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+	  ip60 = vlib_buffer_get_current (b0);
+	  ip61 = vlib_buffer_get_current (b1);
+
+	  vnet_feature_next (&next0, b0);
+	  vnet_feature_next (&next1, b1);
+
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	  sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
+
+	  sol_adv0 = ip6_next_header (ip60);
+	  lladdr0 =
+	    (icmp6_neighbor_discovery_ethernet_link_layer_address_option_t
+	       *) (sol_adv0 + 1);
+
+	  if (PREDICT_TRUE (sol_adv0->icmp.type ==
+			    ICMP6_neighbor_advertisement))
+	    {
+	      aif0 = am->interfaces[sw_if_index0];
+	      if (PREDICT_TRUE (clib_memcmp (&aif0->address.ip.ip6,
+					     &sol_adv0->target_address,
+					     sizeof (aif0->address.ip.ip6)) ==
+				0))
+		{
+		  clib_memcpy_fast (&aif0->recv.from6.ip6,
+				    &sol_adv0->target_address,
+				    sizeof (aif0->recv.from6.ip6));
+		  clib_memcpy_fast (&aif0->recv.from6.mac,
+				    lladdr0->ethernet_address, 6);
+		  aif0->reply_count++;
+		}
+	    }
+
+	  sol_adv1 = ip6_next_header (ip61);
+	  lladdr1 =
+	    (icmp6_neighbor_discovery_ethernet_link_layer_address_option_t
+	       *) (sol_adv1 + 1);
+
+	  if (PREDICT_TRUE (sol_adv1->icmp.type ==
+			    ICMP6_neighbor_advertisement))
+	    {
+	      aif1 = am->interfaces[sw_if_index1];
+	      if (PREDICT_TRUE (clib_memcmp (&aif1->address.ip.ip6,
+					     &sol_adv1->target_address,
+					     sizeof (aif1->address.ip.ip6)) ==
+				0))
+		{
+		  clib_memcpy_fast (&aif1->recv.from6.ip6,
+				    &sol_adv1->target_address,
+				    sizeof (aif1->recv.from6.ip6));
+		  clib_memcpy_fast (&aif1->recv.from6.mac,
+				    lladdr1->ethernet_address, 6);
+		  aif1->reply_count++;
+		}
+	    }
+
+	  if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      arping6_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	      t->type = sol_adv0->icmp.type;
+	      clib_memcpy_fast (&t->reply.ip6, &sol_adv0->target_address,
+				sizeof (t->reply.ip6));
+	      clib_memcpy_fast (&t->reply.mac, lladdr0->ethernet_address, 6);
+	    }
+	  if (PREDICT_FALSE ((b1->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      arping6_trace_t *t = vlib_add_trace (vm, node, b1, sizeof (*t));
+	      t->sw_if_index = vnet_buffer (b1)->sw_if_index[VLIB_RX];
+	      t->type = sol_adv1->icmp.type;
+	      clib_memcpy_fast (&t->reply.ip6, &sol_adv1->target_address,
+				sizeof (t->reply.ip6));
+	      clib_memcpy_fast (&t->reply.mac, lladdr1->ethernet_address, 6);
+	    }
+
+	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index, to_next,
+					   n_left_to_next, bi0, bi1, next0,
+					   next1);
+	}
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 next0, bi0;
+	  vlib_buffer_t *b0;
+	  arping_intf_t *aif0;
+	  u32 sw_if_index0;
+	  ip6_header_t *ip60;
+	  icmp6_neighbor_solicitation_or_advertisement_header_t *sol_adv0;
+	  icmp6_neighbor_discovery_ethernet_link_layer_address_option_t
+	    *lladdr0;
+
+	  bi0 = to_next[0] = from[0];
+
+	  from += 1;
+	  n_left_from -= 1;
+	  to_next += 1;
+	  n_left_to_next -= 1;
+	  next0 = ARPING_NEXT_DROP;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  ip60 = vlib_buffer_get_current (b0);
+
+	  vnet_feature_next (&next0, b0);
+
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+
+	  sol_adv0 = ip6_next_header (ip60);
+	  lladdr0 =
+	    (icmp6_neighbor_discovery_ethernet_link_layer_address_option_t
+	       *) (sol_adv0 + 1);
+	  if (PREDICT_TRUE (sol_adv0->icmp.type ==
+			    ICMP6_neighbor_advertisement))
+	    {
+	      aif0 = am->interfaces[sw_if_index0];
+	      if (PREDICT_TRUE (clib_memcmp (&aif0->address.ip.ip6,
+					     &sol_adv0->target_address,
+					     sizeof (aif0->address.ip.ip6)) ==
+				0))
+		{
+		  clib_memcpy_fast (&aif0->recv.from6.ip6,
+				    &sol_adv0->target_address,
+				    sizeof (aif0->recv.from6.ip6));
+		  clib_memcpy_fast (&aif0->recv.from6.mac,
+				    lladdr0->ethernet_address, 6);
+		  aif0->reply_count++;
+		}
+	    }
+
+	  if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      arping6_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
+	      t->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	      t->type = sol_adv0->icmp.type;
+	      clib_memcpy_fast (&t->reply.ip6, &sol_adv0->target_address,
+				sizeof (t->reply.ip6));
+	      clib_memcpy_fast (&t->reply.mac, lladdr0->ethernet_address, 6);
+	    }
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  return frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (arping6_input_node) =
+{
+  .name = "arping6-input",.vector_size = sizeof (u32),.format_trace =
+    format_arping6_trace,.type = VLIB_NODE_TYPE_INTERNAL,.n_errors =
+    ARPING_N_ERROR,.error_strings = arping_error_strings,.n_next_nodes =
+    ARPING_N_NEXT,.next_nodes =
+  {
+  [ARPING6_NEXT_DROP] = "error-drop",[ARPING6_NEXT_IO] = "interface-output",}
+,};
+
+VNET_FEATURE_INIT (arping6_feat_node, static) = {
+  .arc_name = "ip6-local",
+  .node_name = "arping6-input",
+  .runs_before = VNET_FEATURES ("ip6-local-end-of-arc"),
+};
+
+static clib_error_t *
+arping_neighbor_advertisement (vlib_main_t *vm, arping_args_t *args)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+  u32 send_count = 0;
+
+  while (args->repeat > 0)
+    {
+      send_count++;
+      if (args->address.version == AF_IP4)
+	{
+	  if (args->silence == 0)
+	    vlib_cli_output (vm, "Sending %u GARP to %U", send_count,
+			     format_ip4_address, &args->address.ip.ip4);
+	  ip4_neighbor_advertise (vm, vnm, args->sw_if_index,
+				  &args->address.ip.ip4);
+	}
+      else
+	{
+	  if (args->silence == 0)
+	    vlib_cli_output (vm, "Sending %u Neighbor Advertisement to %U",
+			     send_count, format_ip6_address,
+			     &args->address.ip.ip6);
+	  ip6_neighbor_advertise (vm, vnm, args->sw_if_index,
+				  &args->address.ip.ip6);
+	}
+      args->repeat--;
+      if ((args->interval > 0.0) && (args->repeat > 0))
+	vlib_process_suspend (vm, args->interval);
+    }
+
+  return 0;
+}
+
+static void
+arping_vnet_feature_enable_disable (vlib_main_t *vm, const char *arc_name,
+				    const char *node_name, u32 sw_if_index,
+				    int enable_disable, void *feature_config,
+				    u32 n_feature_config_bytes)
+{
+  vlib_worker_thread_barrier_sync (vm);
+  vnet_feature_enable_disable (arc_name, node_name, sw_if_index,
+			       enable_disable, feature_config,
+			       n_feature_config_bytes);
+  vlib_worker_thread_barrier_release (vm);
+}
+
+static void
+arping_vec_validate (vlib_main_t *vm, u32 sw_if_index)
+{
+  arping_main_t *am = &arping_main;
+
+  if (sw_if_index >= vec_len (am->interfaces))
+    {
+      vlib_worker_thread_barrier_sync (vm);
+      vec_validate (am->interfaces, sw_if_index);
+      vlib_worker_thread_barrier_release (vm);
+    }
+}
+
+static clib_error_t *
+arping_neighbor_probe_dst (vlib_main_t *vm, arping_args_t *args)
+{
+  arping_main_t *am = &arping_main;
+  u32 send_count = 0;
+  clib_error_t *error;
+  arping_intf_t aif;
+
+  /* Disallow multiple sends on the same interface for now. Who needs it? */
+  if (am->interfaces && (am->interfaces[args->sw_if_index] != 0))
+    {
+      error = clib_error_return (
+	0, "arping command is in progress for the same interface. "
+	   "Please try again later.");
+      args->rv = VNET_API_ERROR_INVALID_VALUE;
+      return error;
+    }
+
+  arping_vec_validate (vm, args->sw_if_index);
+  clib_memset (&aif, 0, sizeof (aif));
+  aif.interval = args->interval;
+  aif.repeat = args->repeat;
+  aif.reply_count = 0;
+  am->interfaces[args->sw_if_index] = &aif;
+
+  clib_memcpy (&aif.address, &args->address, sizeof (aif.address));
+  if (args->address.version == AF_IP4)
+    arping_vnet_feature_enable_disable (vm, "arp", "arping-input",
+					args->sw_if_index, 1, 0, 0);
+  else
+    arping_vnet_feature_enable_disable (vm, "ip6-local", "arping6-input",
+					args->sw_if_index, 1, 0, 0);
+
+  while (args->repeat > 0)
+    {
+      send_count++;
+      if (args->address.version == AF_IP4)
+	{
+	  if (args->silence == 0)
+	    vlib_cli_output (vm, "Sending %u ARP Request to %U", send_count,
+			     format_ip4_address, &args->address.ip.ip4);
+	  ip4_neighbor_probe_dst (args->sw_if_index, &args->address.ip.ip4);
+	}
+      else
+	{
+	  if (args->silence == 0)
+	    vlib_cli_output (vm, "Sending %u Neighbor Solicitation  to %U",
+			     send_count, format_ip6_address,
+			     &args->address.ip.ip6);
+	  ip6_neighbor_probe_dst (args->sw_if_index, &args->address.ip.ip6);
+	}
+      args->repeat--;
+      if ((args->interval > 0.0) && (args->repeat > 0))
+	vlib_process_suspend (vm, args->interval);
+    }
+
+  /* wait for a second on the reply */
+  u32 wait_count = 0;
+  while ((aif.reply_count < send_count) && (wait_count < 10))
+    {
+      vlib_process_suspend (vm, 0.1);
+      wait_count++;
+    }
+
+  if (args->address.version == AF_IP4)
+    {
+      clib_memcpy (&args->recv.from4, &aif.recv.from4,
+		   sizeof (args->recv.from4));
+      arping_vnet_feature_enable_disable (vm, "arp", "arping-input",
+					  args->sw_if_index, 0, 0, 0);
+    }
+  else
+    {
+      clib_memcpy (&args->recv.from6, &aif.recv.from6,
+		   sizeof (args->recv.from6));
+      arping_vnet_feature_enable_disable (vm, "ip6-local", "arping6-input",
+					  args->sw_if_index, 0, 0, 0);
+    }
+  args->reply_count = aif.reply_count;
+
+  am->interfaces[args->sw_if_index] = 0;
+
+  return 0;
+}
+
+void
+arping_run_command (vlib_main_t *vm, arping_args_t *args)
+{
+  if (args->is_garp)
+    args->error = arping_neighbor_advertisement (vm, args);
+  else
+    args->error = arping_neighbor_probe_dst (vm, args);
+}
+
+static clib_error_t *
+arping_ip_address (vlib_main_t *vm, unformat_input_t *input,
+		   vlib_cli_command_t *cmd)
+{
+  clib_error_t *error = 0;
+  vnet_main_t *vnm = vnet_get_main ();
+  arping_args_t args = { 0 };
+  f64 interval = ARPING_DEFAULT_INTERVAL;
+
+  args.repeat = ARPING_DEFAULT_REPEAT;
+  args.interval = ARPING_DEFAULT_INTERVAL;
+  args.sw_if_index = ~0;
+  args.silence = 0;
+
+  if (unformat (input, "gratuitous"))
+    args.is_garp = 1;
+
+  if (unformat (input, "%U", unformat_ip4_address, &args.address.ip.ip4))
+    args.address.version = AF_IP4;
+  else if (unformat (input, "%U", unformat_ip6_address, &args.address.ip.ip6))
+    args.address.version = AF_IP6;
+  else
+    {
+      error = clib_error_return (
+	0,
+	"expecting IP4/IP6 address `%U'. Usage: arping [gratuitous] <addr> "
+	"<intf> [repeat <count>] [interval <secs>]",
+	format_unformat_error, input);
+      goto done;
+    }
+
+  if (!unformat_user (input, unformat_vnet_sw_interface, vnm,
+		      &args.sw_if_index))
+    {
+      error = clib_error_return (0, "unknown interface `%U'",
+				 format_unformat_error, input);
+      goto done;
+    }
+
+  /* parse the rest of the parameters  in a cycle */
+  while (!unformat_eof (input, NULL))
+    {
+      if (unformat (input, "interval"))
+	{
+	  if (!unformat (input, "%f", &interval))
+	    {
+	      error = clib_error_return (
+		0, "expecting interval (floating point number) got `%U'",
+		format_unformat_error, input);
+	      goto done;
+	    }
+	  args.interval = interval;
+	}
+      else if (unformat (input, "repeat"))
+	{
+	  if (!unformat (input, "%u", &args.repeat))
+	    {
+	      error =
+		clib_error_return (0, "expecting repeat count but got `%U'",
+				   format_unformat_error, input);
+	      goto done;
+	    }
+	}
+      else
+	{
+	  error = clib_error_return (0, "unknown input `%U'",
+				     format_unformat_error, input);
+	  goto done;
+	}
+    }
+
+  arping_run_command (vm, &args);
+
+  if (args.reply_count)
+    {
+      if (args.address.version == AF_IP4)
+	vlib_cli_output (vm, "Received %u ARP Replies from %U (%U)",
+			 args.reply_count, format_mac_address,
+			 &args.recv.from4.mac, format_ip4_address,
+			 &args.recv.from4.ip4);
+      else
+	vlib_cli_output (
+	  vm, "Received %u ICMP6 neighbor advertisements from %U (%U)",
+	  args.reply_count, format_mac_address, &args.recv.from6.mac,
+	  format_ip6_address, &args.recv.from6.ip6);
+    }
+  else if (args.is_garp == 0)
+    vlib_cli_output (vm, "Received 0 Reply");
+
+  error = args.error;
+done:
+  return error;
+}
+// clang-format off
+/*?
+ * This command sends an ARP REQUEST or gratuitous ARP to network hosts. The
+ * address can be an IPv4 or IPv6 address.
+ *
+ * @cliexpar
+ * @parblock
+ * Example of how to send an IPv4 ARP REQUEST
+ * @cliexstart{arping 100.1.1.10 VirtualEthernet0/0/0 repeat 3 interval 1}
+ * Sending 1 ARP Request to 100.1.1.10
+ * Sending 2 ARP Request to 100.1.1.10
+ * Sending 3 ARP Request to 100.1.1.10
+ * Received 3 ARP Replies from 52:53:00:00:04:01 (100.1.1.10)
+ * @cliexend
+ *
+ * Example of how to send an IPv6 Neighbor Solicitation
+ * @cliexstart{arping 2001:192::2 VirtualEthernet0/0/0 repeat 3 interval 1}
+ * Sending 1 Neighbor Solicitation to 2001:192::2
+ * Sending 2 Neighbor Solicitation to 2001:192::2
+ * Sending 3 Neighbor Solicitation to 2001:192::2
+ * Received 3 ICMP6 neighbor advertisements from 52:53:00:00:04:01 (2001:192::2)
+ * @cliexend
+ *
+ * Example of how to send an IPv4 gratuitous ARP
+ * @cliexstart{arping gratuitous 100.1.1.100 VirtualEthernet0/0/0 repeat 2}
+ * Sending 1 GARP to 100.1.1.100
+ * Sending 2 GARP to 100.1.1.100
+ * @cliexend
+ * @endparblock
+ *
+?*/
+// clang-format on
+VLIB_CLI_COMMAND (arping_command, static) = {
+  .path = "arping",
+  .function = arping_ip_address,
+  .short_help = "arping [gratuitous] {addr} {interface}"
+		" [interval {sec}] [repeat {cnt}]",
+  .is_mp_safe = 1,
+};
+
+static clib_error_t *
+arping_cli_init (vlib_main_t *vm)
+{
+  /* initialize binary API */
+  arping_plugin_api_hookup (vm);
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (arping_cli_init);
+
+VLIB_PLUGIN_REGISTER () = {
+  .version = VPP_BUILD_VER,
+  .description = "Arping (arping)",
+};
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */