session: add unix socket api for app attachment

This is an af_unix socket alternative to the binary api. To enable it,
add use-app-socket-api under session stanza in startup.conf. When the
socket api is enabled, attachments through the binary api are disabled.

The socket api only works with memfd fifo segments, i.e., shm segments
are not supported.

Type: feature

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I55ffcee201d004846daeeec85c700c7e7a578d43

1 files changed, 76 insertions, 0 deletions

diff --git a/src/vnet/session/application_namespace.h b/src/vnet/session/application_namespace.h
index 3a24fe1e6fa..14bea610fc3 100644
--- a/src/vnet/session/application_namespace.h
+++ b/src/vnet/session/application_namespace.h
@@ -13,6 +13,7 @@
  * limitations under the License.
  */
 
+#include <vppinfra/socket.h>
 #include <vnet/vnet.h>
 #include <vnet/session/session_table.h>
 
@@ -48,6 +49,16 @@ typedef struct _app_namespace
    * Application namespace id
    */
   u8 *ns_id;
+
+  /**
+   * Name of socket applications can use to attach to session layer
+   */
+  u8 *sock_name;
+
+  /**
+   * Pool of active application sockets
+   */
+  clib_socket_t *app_sockets;
 } app_namespace_t;
 
 typedef struct _vnet_app_namespace_add_del_args
@@ -80,6 +91,71 @@ app_namespace_get_default (void)
   return app_namespace_get (0);
 }
 
+typedef struct app_ns_api_handle_
+{
+  union
+  {
+    struct
+    {
+      /** app_ns index for files and app_index for sockets */
+      u32 l_index;
+      /** socket index for files and clib file index for sockets */
+      u32 u_index;
+    };
+    uword as_uword;
+  };
+#define aah_app_ns_index l_index
+#define aah_app_wrk_index l_index
+#define aah_sock_index u_index
+#define aah_file_index u_index
+} __attribute__ ((aligned (sizeof (uword)))) app_ns_api_handle_t;
+
+STATIC_ASSERT (sizeof (app_ns_api_handle_t) == sizeof (uword), "not uword");
+
+static inline clib_socket_t *
+appns_sapi_alloc_socket (app_namespace_t * app_ns)
+{
+  clib_socket_t *cs;
+  pool_get_zero (app_ns->app_sockets, cs);
+  return cs;
+}
+
+static inline clib_socket_t *
+appns_sapi_get_socket (app_namespace_t * app_ns, u32 sock_index)
+{
+  if (pool_is_free_index (app_ns->app_sockets, sock_index))
+    return 0;
+  return pool_elt_at_index (app_ns->app_sockets, sock_index);
+}
+
+static inline void
+appns_sapi_free_socket (app_namespace_t * app_ns, clib_socket_t * cs)
+{
+  pool_put (app_ns->app_sockets, cs);
+}
+
+static inline u32
+appns_sapi_socket_index (app_namespace_t * app_ns, clib_socket_t * cs)
+{
+  return (cs - app_ns->app_sockets);
+}
+
+static inline u32
+appns_sapi_socket_handle (app_namespace_t * app_ns, clib_socket_t * cs)
+{
+  return app_namespace_index (app_ns) << 16 | (cs - app_ns->app_sockets);
+}
+
+static inline u32
+appns_sapi_handle_sock_index (u32 sapi_sock_handle)
+{
+  return sapi_sock_handle & 0xffff;
+}
+
+int appns_sapi_add_ns_socket (app_namespace_t * app_ns);
+u8 appns_sapi_enabled (void);
+void appns_sapi_enable (void);
+
 #endif /* SRC_VNET_SESSION_APPLICATION_NAMESPACE_H_ */
 
 /*