Send GARP/NA on bonded intf slave up/down if in active-backup mode

If a bonded interface is in active-backup mode and configured with
IPv4 and/or IPv6 addresses, on slave interface link up/down, send
a GARP packet if configured with an IPv4 address and an unsolcited
NA if configured with an IPv6 address. These packets can help with
faster route convergence in the next hop router/switch.

Change-Id: I68ccb11a4a40cda414704fa08ee0171c952befa2
Signed-off-by: John Lo <loj@cisco.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/src/vnet/ethernet/arp.c b/src/vnet/ethernet/arp.c
index d5dc9cceb39..df68175055e 100644
--- a/src/vnet/ethernet/arp.c
+++ b/src/vnet/ethernet/arp.c
@@ -110,6 +110,9 @@ typedef struct
 
 static const u8 vrrp_prefix[] = { 0x00, 0x00, 0x5E, 0x00, 0x01 };
 
+/* Node index for send_garp_na_process */
+u32 send_garp_na_process_node_index;
+
 static void
 set_ip4_over_ethernet_rpc_callback (vnet_arp_set_ip4_over_ethernet_rpc_args_t
 				    * a);
@@ -2378,6 +2381,86 @@ ethernet_arp_change_mac (u32 sw_if_index)
   /* *INDENT-ON* */
 }
 
+void static
+send_ip4_garp (vlib_main_t * vm, vnet_hw_interface_t * hi)
+{
+  ip4_main_t *i4m = &ip4_main;
+  u32 sw_if_index = hi->sw_if_index;
+  ip4_address_t *ip4_addr = ip4_interface_first_address (i4m, sw_if_index, 0);
+
+  if (ip4_addr)
+    {
+      clib_warning ("Sending GARP for IP4 address %U on sw_if_idex %d",
+		    format_ip4_address, ip4_addr, sw_if_index);
+
+      /* Form GARP packet for output - Gratuitous ARP is an ARP request packet
+         where the interface IP/MAC pair is used for both source and request
+         MAC/IP pairs in the request */
+      u32 bi = 0;
+      ethernet_arp_header_t *h = vlib_packet_template_get_packet
+	(vm, &i4m->ip4_arp_request_packet_template, &bi);
+      clib_memcpy (h->ip4_over_ethernet[0].ethernet, hi->hw_address,
+		   sizeof (h->ip4_over_ethernet[0].ethernet));
+      clib_memcpy (h->ip4_over_ethernet[1].ethernet, hi->hw_address,
+		   sizeof (h->ip4_over_ethernet[1].ethernet));
+      h->ip4_over_ethernet[0].ip4 = ip4_addr[0];
+      h->ip4_over_ethernet[1].ip4 = ip4_addr[0];
+
+      /* Setup MAC header with ARP Etype and broadcast DMAC */
+      vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+      vlib_buffer_advance (b, -sizeof (ethernet_header_t));
+      ethernet_header_t *e = vlib_buffer_get_current (b);
+      e->type = clib_host_to_net_u16 (ETHERNET_TYPE_ARP);
+      clib_memcpy (e->src_address, hi->hw_address, sizeof (e->src_address));
+      memset (e->dst_address, 0xff, sizeof (e->dst_address));
+
+      /* Send GARP packet out the specified interface */
+      vnet_buffer (b)->sw_if_index[VLIB_RX] =
+	vnet_buffer (b)->sw_if_index[VLIB_TX] = sw_if_index;
+      vlib_frame_t *f = vlib_get_frame_to_node (vm, hi->output_node_index);
+      u32 *to_next = vlib_frame_vector_args (f);
+      to_next[0] = bi;
+      f->n_vectors = 1;
+      vlib_put_frame_to_node (vm, hi->output_node_index, f);
+    }
+}
+
+static vlib_node_registration_t send_garp_na_proc_node;
+
+static uword
+send_garp_na_process (vlib_main_t * vm,
+		      vlib_node_runtime_t * rt, vlib_frame_t * f)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+  uword event_type, *event_data = 0;
+
+  send_garp_na_process_node_index = send_garp_na_proc_node.index;
+
+  while (1)
+    {
+      vlib_process_wait_for_event (vm);
+      event_type = vlib_process_get_events (vm, &event_data);
+      if ((event_type == SEND_GARP_NA) && (vec_len (event_data) >= 1))
+	{
+	  u32 hw_if_index = event_data[0];
+	  vnet_hw_interface_t *hi = vnet_get_hw_interface (vnm, hw_if_index);
+	  send_ip4_garp (vm, hi);
+	  send_ip6_na (vm, hi);
+	}
+      vec_reset_length (event_data);
+    }
+  return 0;
+}
+
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (send_garp_na_proc_node, static) = {
+    .function = send_garp_na_process,
+    .type = VLIB_NODE_TYPE_PROCESS,
+    .name = "send-garp-na-process",
+};
+/* *INDENT-ON* */
+
 /*
  * fd.io coding-style-patch-verification: ON
  *