GOON Network 1.5: Ported Datagram Protocol

code/__DEFINES/computer4_defines.dm

@@ -26,3 +26,8 @@
 #define WIRELESS_FILTER_ID_TAGS 2 //! id_tag based filtering, for non-GPRS Control.
 
 #define WIRELESS_FILTER_MODEMAX 2 //! Max of WIRELESS_FILTER_* Defines.
+
+// PDP BindPort return values
+
+#define PDP_BIND_FAILED_CATASTROPHIC 1 //! What the fuck did you do???
+#define PDP_BIND_FAILED_CONFLICT 2 //! Port already bound?

code/__DEFINES/packetnet.dm

@@ -40,6 +40,9 @@
 /// Network Class of a device, used as part of ping replies.
 #define PACKET_NETCLASS "netclass"
 
+#define PACKET_ARG_PROTOCOL "proto"
+	#define PACKET_ARG_PROTOCOL_PDP "pdp"
+
 // Pagers
 /// Packet arg for pager types
 #define PACKET_ARG_PAGER_CLASS "pager_class"
@@ -103,3 +106,23 @@
 #define MAGIC_DATA_INVIOLABLE ALL
 
 #define PACKET_STRING_FILE "packetnet.json"
+
+// -----
+// PDP Protocol Fields
+// These are partially duplicates of above but Deal With It.
+
+#define PDP_SOURCE_ADDRESS PACKET_SOURCE_ADDRESS
+#define PDP_DESTINATION_ADDRESS PACKET_DESTINATION_ADDRESS
+
+#define PDP_SOURCE_PORT "s_port"
+#define PDP_DESTINATION_PORT "d_port"
+
+/// PDP Payload Data. Is a list.
+#define PDP_PAYLOAD_DATA "payload"
+
+
+// -----
+// PDP Port Allocations
+
+#define PDP_MAX_PORT 65535 //! Maximum PDP Port number
+#define PDP_EPHEMERAL_START 64000 //! Start of PDP Ephemeral Range, used for outgoing client connections.

code/modules/computer4/data/socket.dm

@@ -0,0 +1,81 @@
+/*
+ * Ported Datagram Protocol Socket
+ */
+
+#define PDP_SOCKET_QUEUE_DEPTH 50
+/// 'Real' insert position, subject to BYOND Listism.
+#define PDP_S_HEAD_REAL (head_pointer+1)
+/// 'Real' read position, subject to BYOND Listism.
+#define PDP_S_TAIL_REAL (tail_pointer+1)
+
+#if PDP_SOCKET_QUEUE_DEPTH < 3
+#error PDP_SOCKET_QUEUE_DEPTH is too short. If you trigger this, good fucking job:tm:
+#endif
+
+/datum/pdp_socket
+	/// Next Hop datum we send our packets to, Usually an operating system, but may be a physical network device.
+	var/datum/outgoing_datum
+	/// 'Owner' that registered for this socket. Used to assure ownership.
+	var/datum/owner
+	/// PDP Port the socket is bound to, Packets being sent out of this socket will have their source port set to this.
+	var/bound_port
+
+
+	/// Packet ring buffer
+	VAR_PRIVATE/list/packet_buffer
+	/// Insertion point, Incremented on packet receive. Will drop instead if =tail_pointer-1
+	/// Do not use directly, Must add 1 to account for list jank
+	VAR_PRIVATE/head_pointer
+	/// Read pointer, Incremented on packet read, Will not increment if there is no packet to read.
+	VAR_PRIVATE/tail_pointer
+
+/datum/pdp_socket/New(bound_port, outgoing_datum, owner)
+	if(!bound_port)
+		stack_trace("Created a PDP socket without a port number?")
+
+	src.bound_port = bound_port
+	src.outgoing_datum = outgoing_datum
+	src.owner = owner
+	packet_buffer = new /list(PDP_SOCKET_QUEUE_DEPTH)
+	head_pointer = 0
+	tail_pointer = 0
+
+/// Place received packet into ringqueue. Returns TRUE if inserted, FALSE if dropped due to full queue.
+// No lohi I am not implimenting DSCP. Right now, at least. Maybe later.
+/datum/pdp_socket/proc/enqueue(datum/signal/packet)
+	if(((head_pointer + 1) % PDP_SOCKET_QUEUE_DEPTH) == tail_pointer)
+		return FALSE //Ring full, Drop the packet.
+	packet_buffer[PDP_S_HEAD_REAL] = packet
+	head_pointer = (head_pointer+1) % PDP_SOCKET_QUEUE_DEPTH
+	return TRUE
+
+/// Get next signal in queue, or null if queue is dry.
+/datum/pdp_socket/proc/pop()
+	. = packet_buffer[PDP_S_TAIL_REAL]
+	if(!.)
+		return null
+	tail_pointer = (tail_pointer+1) % PDP_SOCKET_QUEUE_DEPTH
+	//return .
+
+#undef PDP_SOCKET_QUEUE_DEPTH
+#undef PDP_S_HEAD_REAL
+#undef PDP_S_TAIL_REAL
+
+/// Send a PDP payload packet to the destionation port and address.
+/datum/pdp_socket/proc/send_data(d_address, d_port, list/payload)
+	// Packets come out of this preeetty skeletonized, Higher layers above this are expected to fill out some remaining details
+	// Such as source address.
+
+	var/list/packet_data = list(
+		PACKET_ARG_PROTOCOL = PACKET_ARG_PROTOCOL_PDP,
+
+		PDP_DESTINATION_ADDRESS = d_address,
+		PDP_DESTINATION_PORT = d_port,
+
+		//Source address set at NIC
+		PDP_SOURCE_PORT = bound_port,
+
+		PDP_PAYLOAD_DATA = payload
+	)
+
+	var/datum/signal/packet = new(null, packet_data)

code/modules/computer4/data/terminal/medtrak/medtrak.dm

@@ -68,7 +68,10 @@
 /// Getter for the log file. This isn't kept as a ref because I don't want to manage the ref. :)
 /datum/c4_file/terminal_program/medtrak/proc/get_log_file()
 	RETURN_TYPE(/datum/c4_file/text)
-	var/datum/c4_file/folder/log_dir = get_os().get_log_folder()
+
+	// Sue me. Come up with a better way to do this that doesn't demand dead procs on the OS basetype.
+	// (Suggestion: Move medtrak and such to a thinkdos-specific subtype of terminal_program) (t_prog/dos/medtrak)
+	var/datum/c4_file/folder/log_dir = get_os():get_log_folder()
 	if(!log_dir)
 		return null