Implement ip_probe_neighbor API

Add API support similar to VPP CLI "ip probe-neighbor" except API
call is asynch and will not wait, as the CLI does, for address
resolution of probed neighbor. The API client can use the APIs
want_ip4_arp_events or want_ip6_nd_events to get notified of the
desired address resolution event.

Change-Id: Ieab58abe75b5cc7f5185b3b91418b6362f8992d3
Signed-off-by: John Lo <loj@cisco.com>

2 files changed, 63 insertions, 9 deletions

diff --git a/src/vnet/ip/ip.api b/src/vnet/ip/ip.api
index 2ca2f56c58b..38024926ab7 100644
--- a/src/vnet/ip/ip.api
+++ b/src/vnet/ip/ip.api
@@ -19,7 +19,7 @@
     called through a shared memory interface. 
 */
 
-option version = "1.2.0";
+option version = "1.2.2";
 import "vnet/fib/fib_types.api";
 
 /** \brief Add / del table request
@@ -650,12 +650,31 @@ autoreply define ip_source_and_port_range_check_interface_add_del
   u32 udp_out_vrf_id;
 };
 
-/** \brief Register for ip4 arp resolution events
+/** \brief IP probe neighbor address on an interface by sending an
+           ARP request (for IP4) or ICMP6 Neighbor Solicitation (for IP6)
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param sw_if_index - interface index
+    @param dst_address - target IP address to send IP addr resolution request
+    @param is_ipv6 - [1|0] to indicate if address family is IPv[6|4]
+*/
+autoreply define ip_probe_neighbor
+{
+  u32 client_index;
+  u32 context;
+  u32 sw_if_index;
+  u8 dst_address[16];
+  u8 is_ipv6;
+};
+
+/** \brief Register for IP4 ARP resolution event on receing ARP reply or
+           MAC/IP info from ARP requests in L2 BDs
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
     @param enable_disable - 1 => register for events, 0 => cancel registration
     @param pid - sender's pid
-    @param address - the exact ip4 address of interest
+    @param address - exact IP4 address of interested arp resolution event, or
+                     0 to get MAC/IP info from ARP requests in BDs
 */
 autoreply define want_ip4_arp_events
 {
@@ -666,13 +685,14 @@ autoreply define want_ip4_arp_events
   u32 address;
 };
 
-/** \brief Tell client about an ip4 arp resolution event
+/** \brief Tell client about an IP4 ARP resolution event or
+           MAC/IP info from ARP requests in L2 BDs
     @param client_index - opaque cookie to identify the sender
     @param address - the exact ip4 address of interest
     @param pid - client pid registered to receive notification
     @param sw_if_index - interface which received ARP packet
     @param new_mac - the new mac address 
-    @param mac_ip - 0: resolution event, 1: mac/ip binding in bd
+    @param mac_ip - 0: ARP resolution event, 1: MAC/IP info from L2 BDs
 */
 define ip4_arp_event
 {
@@ -689,12 +709,14 @@ service {
     events ip4_arp_event;
 };
 
-/** \brief Register for ip6 nd resolution events
+/** \brief Register for IP6 ND resolution event on recieving NA reply
+           MAC/IP info from ICMP6 Neighbor Solicitation in L2 BDs
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
     @param enable_disable - 1 => register for events, 0 => cancel registration
     @param pid - sender's pid
-    @param address - the exact ip6 address of interest
+    @param address - the exact IP6 address of interested ND resolution event, or
+                     0 to get MAC/IP info from ICMP6 NS in L2 BDs.
 */
 autoreply define want_ip6_nd_events
 {
@@ -705,13 +727,14 @@ autoreply define want_ip6_nd_events
   u8 address[16];
 };
 
-/** \brief Tell client about an ip6 nd resolution or mac/ip event
+/** \brief Tell client about an IP6 ND resolution or
+           MAC/IP info from ICMP6 Neighbor Solicitation in L2 BDs.
     @param client_index - opaque cookie to identify the sender
     @param pid - client pid registered to receive notification
     @param sw_if_index - interface which received ARP packet
     @param address - the exact ip6 address of interest
     @param new_mac - the new mac address 
-    @param mac_ip - 0: resolution event, 1: mac/ip binding in bd
+    @param mac_ip - 0: ND resolution event, 1: MAC/IP info from L2 BDs
 */
 define ip6_nd_event
 {
diff --git a/src/vnet/ip/ip_api.c b/src/vnet/ip/ip_api.c
index 0b0a7a949e0..69ff719f3b9 100644
--- a/src/vnet/ip/ip_api.c
+++ b/src/vnet/ip/ip_api.c
@@ -76,6 +76,7 @@ _(IP_ADDRESS_DUMP, ip_address_dump)                                     \
 _(IP_DUMP, ip_dump)                                                     \
 _(IP_NEIGHBOR_ADD_DEL, ip_neighbor_add_del)                             \
 _(SET_ARP_NEIGHBOR_LIMIT, set_arp_neighbor_limit)			\
+_(IP_PROBE_NEIGHBOR, ip_probe_neighbor)      			        \
 _(WANT_IP4_ARP_EVENTS, want_ip4_arp_events)                             \
 _(WANT_IP6_ND_EVENTS, want_ip6_nd_events)                               \
 _(WANT_IP6_RA_EVENTS, want_ip6_ra_events)                               \
@@ -2684,6 +2685,36 @@ static void
   REPLY_MACRO (VL_API_PROXY_ARP_INTFC_ENABLE_DISABLE_REPLY);
 }
 
+static void
+vl_api_ip_probe_neighbor_t_handler (vl_api_ip_probe_neighbor_t * mp)
+{
+  int rv = 0;
+  vlib_main_t *vm = vlib_get_main ();
+  vl_api_ip_probe_neighbor_reply_t *rmp;
+  clib_error_t *error;
+
+  VALIDATE_SW_IF_INDEX (mp);
+
+  u32 sw_if_index = ntohl (mp->sw_if_index);
+
+  if (mp->is_ipv6)
+    error = ip6_probe_neighbor (vm, (ip6_address_t *) mp->dst_address,
+				sw_if_index);
+  else
+    error = ip4_probe_neighbor (vm, (ip4_address_t *) mp->dst_address,
+				sw_if_index);
+
+  if (error)
+    {
+      clib_error_report (error);
+      rv = clib_error_get_code (error);
+    }
+
+  BAD_SW_IF_INDEX_LABEL;
+
+  REPLY_MACRO (VL_API_PROXY_ARP_INTFC_ENABLE_DISABLE_REPLY);
+}
+
 static int
 ip4_reset_fib_t_handler (vl_api_reset_fib_t * mp)
 {