bond: send gratuitous arp when the active slave went down in active-backup mode

- Modify the API send_ip6_na and send_ip4_garp to take sw_if_index instead
of vnet_hw_interface_t and add call to build_ethernet_rewrite to support
subinterface/vlan
- Add code to bonding driver to send an event to bond_process when the first
interface becomes active or when the active interface is down
- Create a bond_process to walk the interface and the corresponding
subinterfaces to send garp/ip6_na when an event is received.
- Minor cleanup in bonding/node.c

Note: dpdk bonding driver does not send garp/ip6_na for subinterfaces. There is
no attempt to fix it here. But the infra is now done and should be easy to
add the support.

Change-Id: If3ecc4cd0fb3051330f7fa11ca0dab3e18557ce1
Signed-off-by: Steven <sluong@cisco.com>

2 files changed, 16 insertions, 14 deletions

diff --git a/src/vnet/ethernet/arp.c b/src/vnet/ethernet/arp.c
index 249e3b6e8cf..682bc2a2c92 100644
--- a/src/vnet/ethernet/arp.c
+++ b/src/vnet/ethernet/arp.c
@@ -2526,22 +2526,22 @@ ethernet_arp_change_mac (u32 sw_if_index)
 }
 
 void
-send_ip4_garp (vlib_main_t * vm, const vnet_hw_interface_t * hi)
+send_ip4_garp (vlib_main_t * vm, u32 sw_if_index)
 {
   ip4_main_t *i4m = &ip4_main;
-  ip4_address_t *ip4_addr =
-    ip4_interface_first_address (i4m, hi->sw_if_index, 0);
+  ip4_address_t *ip4_addr = ip4_interface_first_address (i4m, sw_if_index, 0);
 
-  send_ip4_garp_w_addr (vm, ip4_addr, hi);
+  send_ip4_garp_w_addr (vm, ip4_addr, sw_if_index);
 }
 
 void
 send_ip4_garp_w_addr (vlib_main_t * vm,
-		      const ip4_address_t * ip4_addr,
-		      const vnet_hw_interface_t * hi)
+		      const ip4_address_t * ip4_addr, u32 sw_if_index)
 {
   ip4_main_t *i4m = &ip4_main;
-  u32 sw_if_index = hi->sw_if_index;
+  vnet_main_t *vnm = vnet_get_main ();
+  u8 *rewrite, rewrite_len;
+  vnet_hw_interface_t *hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
 
   if (ip4_addr)
     {
@@ -2563,11 +2563,14 @@ send_ip4_garp_w_addr (vlib_main_t * vm,
 
       /* 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));
+      rewrite =
+	ethernet_build_rewrite (vnm, sw_if_index, VNET_LINK_ARP,
+				VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST);
+      rewrite_len = vec_len (rewrite);
+      vlib_buffer_advance (b, -rewrite_len);
       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));
+      clib_memcpy (e->dst_address, rewrite, rewrite_len);
+      vec_free (rewrite);
 
       /* Send GARP packet out the specified interface */
       vnet_buffer (b)->sw_if_index[VLIB_RX] =
diff --git a/src/vnet/ethernet/arp_packet.h b/src/vnet/ethernet/arp_packet.h
index d2a23a5949f..e5f424d7879 100644
--- a/src/vnet/ethernet/arp_packet.h
+++ b/src/vnet/ethernet/arp_packet.h
@@ -168,10 +168,9 @@ ethernet_arp_ip4_entry_t *ip4_neighbors_pool (void);
 ethernet_arp_ip4_entry_t *ip4_neighbor_entries (u32 sw_if_index);
 u8 *format_ethernet_arp_ip4_entry (u8 * s, va_list * va);
 
-void send_ip4_garp (vlib_main_t * vm, const vnet_hw_interface_t * hi);
+void send_ip4_garp (vlib_main_t * vm, u32 sw_if_index);
 void send_ip4_garp_w_addr (vlib_main_t * vm,
-			   const ip4_address_t * ip4_addr,
-			   const vnet_hw_interface_t * hi);
+			   const ip4_address_t * ip4_addr, u32 sw_if_index);
 
 #endif /* included_ethernet_arp_packet_h */