Added UNIX domain socket configuration settings. (#313)

# New Features
- Added UNIX domain socket configuration settings

python/fusion_engine_client/messages/configuration.py

@@ -54,6 +54,8 @@ class InterfaceConfigType(IntEnum):
   REMOTE_ADDRESS = 3
   PORT = 4
   ENABLED = 5
+  DIRECTION = 6
+  SOCKET_TYPE = 7
 
 
 class Direction(IntEnum):
@@ -159,12 +161,26 @@ class TransportType(IntEnum):
     UDP_CLIENT = 5
     UDP_SERVER = 6
     WEBSOCKET_SERVER = 7
+    UNIX = 8
     ## Set/get the configuration for the interface on which the command was received.
     CURRENT = 254
     ## Set/get the configuration for the all I/O interfaces.
     ALL = 255
 
 
+class TransportDirection(IntEnum):
+    INVALID = 0
+    SERVER = 1
+    CLIENT = 2
+
+
+class SocketType(IntEnum):
+    INVALID = 0
+    STREAM = 1
+    DATAGRAM = 2
+    SEQPACKET = 3
+
+
 class UpdateAction(IntEnum):
     REPLACE = 0
 
@@ -414,6 +430,17 @@ class BoolVal(NamedTuple):
         "value" / Flag,
     )
 
+    # Enum helpers.
+    @staticmethod
+    def _define_enum_classes(enum_type, construct_type=Int8ul):
+        class EnumVal(NamedTuple):
+            value: enum_type = list(enum_type)[0]
+        construct = AutoEnum(construct_type, enum_type)
+        return EnumVal, construct
+
+    TransportDirectionVal, TransportDirectionConstruct = _define_enum_classes(TransportDirection, Int8ul)
+    SocketTypeVal, SocketTypeConstruct = _define_enum_classes(SocketType, Int8ul)
+
     class StringVal(NamedTuple):
         """!
         @brief String value specifier.
@@ -907,34 +934,55 @@ class HeadingBias(_conf_gen.HeadingBias):
     """
     pass
 
+
 @_conf_gen.create_interface_config_class(InterfaceConfigType.BAUD_RATE, _conf_gen.UInt32Construct)
 class InterfaceBaudRateConfig(_conf_gen.IntegerVal):
     """!
     @brief Interface baud configuration settings.
     """
     pass
 
+
 @_conf_gen.create_interface_config_class(InterfaceConfigType.PORT, _conf_gen.UInt16Construct)
 class InterfacePortConfig(_conf_gen.IntegerVal):
     """!
     @brief Interface network port configuration settings.
     """
     pass
 
+
 @_conf_gen.create_interface_config_class(InterfaceConfigType.REMOTE_ADDRESS, _conf_gen.StringConstruct(64))
 class InterfaceRemoteAddressConfig(_conf_gen.StringVal):
     """!
     @brief Configure the network address for a client to connect to.
     """
     pass
 
+
 @_conf_gen.create_interface_config_class(InterfaceConfigType.ENABLED, _conf_gen.BoolConstruct)
 class InterfaceEnabledConfig(_conf_gen.BoolVal):
     """!
     @brief Interface enabled/disabled configuration settings.
     """
     pass
 
+
+@_conf_gen.create_interface_config_class(InterfaceConfigType.DIRECTION, _conf_gen.TransportDirectionConstruct)
+class InterfaceDirectionConfig(_conf_gen.TransportDirectionVal):
+    """!
+    @brief Interface transport direction (client/server) configuration settings.
+    """
+    pass
+
+
+@_conf_gen.create_interface_config_class(InterfaceConfigType.SOCKET_TYPE, _conf_gen.SocketTypeConstruct)
+class InterfaceSocketTypeConfig(_conf_gen.SocketTypeVal):
+    """!
+    @brief UNIX domain socket type configuration (stream, datagram, sequence).
+    """
+    pass
+
+
 @_conf_gen.create_interface_config_class(InterfaceConfigType.OUTPUT_DIAGNOSTICS_MESSAGES, _conf_gen.BoolConstruct)
 class InterfaceDiagnosticMessagesEnabled(_conf_gen.BoolVal):
     """!

src/point_one/fusion_engine/messages/configuration.h

@@ -373,9 +373,13 @@ enum class InterfaceConfigType : uint8_t {
   /**
    * Configure the network address for a client to connect to.
    *
+   * For UNIX domain sockets, this string represents the path to the local
+   * socket file.
+   *
    * Valid for:
    * - @ref TransportType::TCP_CLIENT
    * - @ref TransportType::UDP_CLIENT
+   * - @ref TransportType::UNIX
    *
    * Payload format: `char[64]` containing a NULL terminated string.
    */
@@ -398,13 +402,31 @@ enum class InterfaceConfigType : uint8_t {
   /**
    * Enable/disable the interface.
    *
-   * Valid for:
-   * - @ref TransportType::TCP_CLIENT
-   * - @ref TransportType::UDP_CLIENT
+   * Valid for all @ref TransportType values.
    *
    * Payload format: `bool`
    */
   ENABLED = 5,
+
+  /**
+   * Set the interface direction (client/server).
+   *
+   * Valid for:
+   * - @ref TransportType::UNIX
+   *
+   * Payload format: @ref TransportDirection
+   */
+  DIRECTION = 6,
+
+  /**
+   * Set the UNIX domain socket type (streaming/datagram/sequenced).
+   *
+   * Valid for:
+   * - @ref TransportType::UNIX
+   *
+   * Payload format: @ref SocketType
+   */
+  SOCKET_TYPE = 7,
 };
 
 /**
@@ -435,6 +457,12 @@ P1_CONSTEXPR_FUNC const char* to_string(InterfaceConfigType type) {
     case InterfaceConfigType::ENABLED:
       return "Interface Enabled";
 
+    case InterfaceConfigType::DIRECTION:
+      return "Transport Direction";
+
+    case InterfaceConfigType::SOCKET_TYPE:
+      return "Socket Type";
+
     default:
       return "Unrecognized Configuration";
   }
@@ -1577,6 +1605,27 @@ enum class TransportType : uint8_t {
   UDP_SERVER = 6,
   /** An interface that will communicate with connected clients. */
   WEBSOCKET_SERVER = 7,
+  /**
+   * A UNIX domain socket client or server.
+   *
+   * UNIX domain socket connections may be configured as either client that
+   * connects to an existing server, or a server that listens for one or more
+   * incoming client connections. UNIX domain sockets may operate in one of
+   * three possible modes:
+   * - A connection-oriented streaming mode where packet boundaries are not
+   *   preserved (similar to TCP)
+   * - Datagram mode where packet boundaries are preserved but connections
+   *   between the client and server are not maintained, and the interface sends
+   *   output to an optional configured file (similar to UDP)
+   * - Sequenced packet mode, which is connection-oriented (like TCP) but also
+   *   preserves message boundaries (like UDP) and guarantees in-order delivery
+   *
+   * For a UNIX domain socket, you must specify:
+   * - The @ref TransportDirection (client or server)
+   * - The @ref SocketType (streaming, datagram, or sequenced)
+   * - The path to a socket file to connect to (client) or create (server)
+   */
+  UNIX = 8,
   /**
    * Set/get the configuration for the interface on which the command was
    * received.
@@ -1613,6 +1662,8 @@ P1_CONSTEXPR_FUNC const char* to_string(TransportType val) {
       return "UDP Server";
     case TransportType::WEBSOCKET_SERVER:
       return "Websocket Server";
+    case TransportType::UNIX:
+      return "UNIX";
     case TransportType::CURRENT:
       return "Current";
     case TransportType::ALL:
@@ -1630,6 +1681,101 @@ inline p1_ostream& operator<<(p1_ostream& stream, TransportType val) {
   return stream;
 }
 
+/**
+ * @brief The direction (client/server) for an individual interface.
+ */
+enum class TransportDirection : uint8_t {
+  INVALID = 0,
+  /** A server listening for one or more incoming remote connections. */
+  SERVER = 1,
+  /** A client connecting to a specified remote server. */
+  CLIENT = 2,
+};
+
+/**
+ * @brief Get a human-friendly string name for the specified @ref
+ *        TransportDirection.
+ * @ingroup config_and_ctrl_messages
+ *
+ * @param val The enum to get the string name for.
+ *
+ * @return The corresponding string name.
+ */
+P1_CONSTEXPR_FUNC const char* to_string(TransportDirection val) {
+  switch (val) {
+    case TransportDirection::INVALID:
+      return "INVALID";
+    case TransportDirection::SERVER:
+      return "SERVER";
+    case TransportDirection::CLIENT:
+      return "CLIENT";
+  }
+  return "Unrecognized";
+}
+
+/**
+ * @brief @ref TransportDirection stream operator.
+ * @ingroup config_and_ctrl_messages
+ */
+inline p1_ostream& operator<<(p1_ostream& stream, TransportDirection val) {
+  stream << to_string(val) << " (" << (int)val << ")";
+  return stream;
+}
+
+/**
+ * @brief The socket type specifying how data is transmitted for UNIX domain
+ *        sockets.
+ */
+enum class SocketType : uint8_t {
+  INVALID = 0,
+  /**
+   * Operate in connection-oriented streaming mode and do not preserve message
+   * boundaries (similar to TCP).
+   */
+  STREAM = 1,
+  /**
+   * Operate in datagram mode, preserving message boundaries but not maintaining
+   * client connections (similar to UDP).
+   */
+  DATAGRAM = 2,
+  /**
+   * Operate in sequenced packet mode, which is both connection-oriented and
+   * preserves message boundaries.
+   */
+  SEQPACKET = 3,
+};
+
+/**
+ * @brief Get a human-friendly string name for the specified @ref SocketType.
+ * @ingroup config_and_ctrl_messages
+ *
+ * @param val The enum to get the string name for.
+ *
+ * @return The corresponding string name.
+ */
+P1_CONSTEXPR_FUNC const char* to_string(SocketType val) {
+  switch (val) {
+    case SocketType::INVALID:
+      return "INVALID";
+    case SocketType::STREAM:
+      return "STREAM";
+    case SocketType::DATAGRAM:
+      return "DATAGRAM";
+    case SocketType::SEQPACKET:
+      return "SEQPACKET";
+  }
+  return "Unrecognized";
+}
+
+/**
+ * @brief @ref SocketType stream operator.
+ * @ingroup config_and_ctrl_messages
+ */
+inline p1_ostream& operator<<(p1_ostream& stream, SocketType val) {
+  stream << to_string(val) << " (" << (int)val << ")";
+  return stream;
+}
+
 /**
  * @brief Identifies an I/O interface.
  *