PUNT socket: External control plane processes connected via UNIX domain sockets.

An external (to VPP) process can register (over the VPP binary API) to
receive control plane packets over a UNIX domain socket. The packets are
prepended with a packet descriptor containing meta-data (if_index of
interface, etc).

Currently only UDP is supported.

The socket supports sending of packets/frames as well.
The sent packet is prepended with a descriptor, telling VPP to
route the packet (via ip4-lookup, ip6-lookup) or as an pre-formed
Ethernet frame that is sent directly to interface-output.

The intended use case for this is for an external DHCP client or
a RIP implementation.

New configuration option:

punt { socket <socket path> }

To register use the punt_socket API message.

TODO:
  - Add support for pre-routing. I.e send L3 packet to given
    TX interface, but do ARP/ND (ip[46]-rewrite)
  - Add test scripts
  - Support for abstract names (starting with \0)
  - Add rate limiting (COP)
  - Support for other protocols, e.g. IPv6 ND

Change-Id: I4a0afc8020deebb3d9d74686dde694ee5bcb8d0f
Signed-off-by: Ole Troan <ot@cisco.com>

1 files changed, 64 insertions, 0 deletions

diff --git a/src/vpp/api/api.c b/src/vpp/api/api.c
index 4e892431376..e8bc22ae563 100644
--- a/src/vpp/api/api.c
+++ b/src/vpp/api/api.c
@@ -144,6 +144,8 @@ _(IP_SOURCE_AND_PORT_RANGE_CHECK_INTERFACE_ADD_DEL,                     \
   ip_source_and_port_range_check_interface_add_del)                     \
 _(DELETE_SUBIF, delete_subif)                                           \
 _(PUNT, punt)                                                           \
+_(PUNT_SOCKET_REGISTER, punt_socket_register)                           \
+_(PUNT_SOCKET_DEREGISTER, punt_socket_deregister)                       \
 _(FEATURE_ENABLE_DISABLE, feature_enable_disable)
 
 #define QUOTE_(x) #x
@@ -1941,6 +1943,68 @@ vl_api_punt_t_handler (vl_api_punt_t * mp)
 }
 
 static void
+vl_api_punt_socket_register_t_handler (vl_api_punt_socket_register_t * mp)
+{
+  vl_api_punt_socket_register_reply_t *rmp;
+  vlib_main_t *vm = vlib_get_main ();
+  int rv = 0;
+  clib_error_t *error;
+  unix_shared_memory_queue_t *q;
+  u32 handle;
+
+  error = vnet_punt_socket_add (vm, ntohl (mp->header_version),
+				mp->is_ip4, mp->l4_protocol,
+				ntohs (mp->l4_port), (char *) mp->pathname);
+  if (error)
+    {
+      rv = -1;
+      clib_error_report (error);
+    }
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (!q)
+    return;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  rmp->_vl_msg_id = htons (VL_API_PUNT_SOCKET_REGISTER_REPLY);
+  rmp->context = mp->context;
+  rmp->retval = htonl (rv);
+  char *p = vnet_punt_get_server_pathname ();
+  /* Abstract pathnames start with \0 */
+  memcpy ((char *) rmp->pathname, p, sizeof (rmp->pathname));
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
+vl_api_punt_socket_deregister_t_handler (vl_api_punt_socket_deregister_t * mp)
+{
+  vl_api_punt_socket_deregister_reply_t *rmp;
+  vlib_main_t *vm = vlib_get_main ();
+  int rv = 0;
+  clib_error_t *error;
+  unix_shared_memory_queue_t *q;
+  u32 handle;
+
+  error = vnet_punt_socket_del (vm, mp->is_ip4, mp->l4_protocol,
+				ntohs (mp->l4_port));
+  if (error)
+    {
+      rv = -1;
+      clib_error_report (error);
+    }
+
+  q = vl_api_client_index_to_input_queue (mp->client_index);
+  if (!q)
+    return;
+
+  rmp = vl_msg_api_alloc (sizeof (*rmp));
+  rmp->_vl_msg_id = htons (VL_API_PUNT_SOCKET_DEREGISTER_REPLY);
+  rmp->context = mp->context;
+  rmp->retval = htonl (rv);
+  vl_msg_api_send_shmem (q, (u8 *) & rmp);
+}
+
+static void
 vl_api_feature_enable_disable_t_handler (vl_api_feature_enable_disable_t * mp)
 {
   vl_api_feature_enable_disable_reply_t *rmp;