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, 50 insertions, 2 deletions

diff --git a/src/vnet/ip/punt.h b/src/vnet/ip/punt.h
index 09a9d4c55bf..0103249cca0 100644
--- a/src/vnet/ip/punt.h
+++ b/src/vnet/ip/punt.h
@@ -20,6 +20,7 @@
 #ifndef included_punt_h
 #define included_punt_h
 
+#include <sys/un.h>
 typedef enum
 {
 #define punt_error(n,s) PUNT_ERROR_##n,
@@ -30,9 +31,56 @@ typedef enum
 
 
 clib_error_t *vnet_punt_add_del (vlib_main_t * vm, u8 ipv,
-				 u8 protocol, u16 port, int is_add);
+				 u8 protocol, u16 port, bool is_add);
+clib_error_t *vnet_punt_socket_add (vlib_main_t * vm, u32 header_version,
+				    bool is_ip4, u8 protocol, u16 port,
+				    char *client_pathname);
+clib_error_t *vnet_punt_socket_del (vlib_main_t * vm, bool is_ip4,
+				    u8 l4_protocol, u16 port);
+char *vnet_punt_get_server_pathname (void);
 
-#endif /* included_punt_h */
+enum punt_action_e
+{
+  PUNT_L2 = 0,
+  PUNT_IP4_ROUTED,
+  PUNT_IP6_ROUTED,
+};
+
+/*
+ * Packet descriptor header. Version 1
+ * If this header changes, the version must also change to notify clients.
+ */
+#define PUNT_PACKETDESC_VERSION 1
+typedef struct __attribute__ ((packed))
+{
+  u32 sw_if_index;		/* RX or TX interface */
+  enum punt_action_e action;
+} punt_packetdesc_t;
+
+/*
+ * Client registration
+ */
+typedef struct
+{
+  u16 port;
+  struct sockaddr_un caddr;
+} punt_client_t;
+
+typedef struct
+{
+  int socket_fd;
+  char sun_path[sizeof (struct sockaddr_un)];
+  punt_client_t *clients_by_dst_port4;
+  punt_client_t *clients_by_dst_port6;
+  u32 unix_file_index;
+  bool is_configured;
+  vlib_node_t *interface_output_node;
+  u32 *ready_fds;
+  u32 *rx_buffers;
+} punt_main_t;
+extern punt_main_t punt_main;
+
+#endif
 
 /*
  * fd.io coding-style-patch-verification: ON