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>

2 files changed, 55 insertions, 0 deletions

diff --git a/src/vnet/ip/ip6.h b/src/vnet/ip/ip6.h
index d623c95f52f..cf52994e720 100644
--- a/src/vnet/ip/ip6.h
+++ b/src/vnet/ip/ip6.h
@@ -375,6 +375,8 @@ int vnet_ip6_nd_term (vlib_main_t * vm,
 		      ethernet_header_t * eth,
 		      ip6_header_t * ip, u32 sw_if_index, u16 bd_index);
 
+void send_ip6_na (vlib_main_t * vm, vnet_hw_interface_t * hi);
+
 u8 *format_ip6_forward_next_trace (u8 * s, va_list * args);
 
 u32 ip6_tcp_udp_icmp_validate_checksum (vlib_main_t * vm, vlib_buffer_t * p0);
diff --git a/src/vnet/ip/ip6_neighbor.c b/src/vnet/ip/ip6_neighbor.c
index ba7ea143318..b8f6f9b10e7 100644
--- a/src/vnet/ip/ip6_neighbor.c
+++ b/src/vnet/ip/ip6_neighbor.c
@@ -4192,6 +4192,59 @@ ethernet_ndp_change_mac (u32 sw_if_index)
   /* *INDENT-ON* */
 }
 
+void
+send_ip6_na (vlib_main_t * vm, vnet_hw_interface_t * hi)
+{
+  ip6_main_t *i6m = &ip6_main;
+  u32 sw_if_index = hi->sw_if_index;
+  ip6_address_t *ip6_addr = ip6_interface_first_address (i6m, sw_if_index);
+  if (ip6_addr)
+    {
+      clib_warning
+	("Sending unsolicitated NA IP6 address %U on sw_if_idex %d",
+	 format_ip6_address, ip6_addr, sw_if_index);
+
+      /* Form unsolicited neighbor advertisement packet from NS pkt template */
+      int bogus_length;
+      u32 bi = 0;
+      icmp6_neighbor_solicitation_header_t *h =
+	vlib_packet_template_get_packet (vm,
+					 &i6m->discover_neighbor_packet_template,
+					 &bi);
+      ip6_set_reserved_multicast_address (&h->ip.dst_address,
+					  IP6_MULTICAST_SCOPE_link_local,
+					  IP6_MULTICAST_GROUP_ID_all_hosts);
+      h->ip.src_address = ip6_addr[0];
+      h->neighbor.icmp.type = ICMP6_neighbor_advertisement;
+      h->neighbor.target_address = ip6_addr[0];
+      h->neighbor.advertisement_flags = clib_host_to_net_u32
+	(ICMP6_NEIGHBOR_ADVERTISEMENT_FLAG_OVERRIDE);
+      clib_memcpy (h->link_layer_option.ethernet_address,
+		   hi->hw_address, vec_len (hi->hw_address));
+      h->neighbor.icmp.checksum =
+	ip6_tcp_udp_icmp_compute_checksum (vm, 0, &h->ip, &bogus_length);
+      ASSERT (bogus_length == 0);
+
+      /* Setup MAC header with IP6 Etype and mcast 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_IP6);
+      clib_memcpy (e->src_address, hi->hw_address, sizeof (e->src_address));
+      ip6_multicast_ethernet_address (e->dst_address,
+				      IP6_MULTICAST_GROUP_ID_all_hosts);
+
+      /* Send unsolicited ND advertisement 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);
+    }
+}
+
 /*
  * fd.io coding-style-patch-verification: ON
  *