# HG changeset patch
# User Medo <smaxein@googlemail.com>
# Date 1338679458 -7200
# Node ID 906e72caea7b27291c723471cf2afe38b7573975
# Parent  b66eef8c8092d121a07321ab44f4c1f8c0c03030
frontlib refactoring

socket.h now completely wraps all the lowlevel neworking, so it would be easy
to switch away from SDL_net if needed. Also reduced global state by making an
IPC connection an object-like thing.

diff -r b66eef8c8092 -r 906e72caea7b project_files/frontlib/events.c
--- a/project_files/frontlib/events.c	Sat Jun 02 22:54:09 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,2 +0,0 @@
-#include "events.h"
-
diff -r b66eef8c8092 -r 906e72caea7b project_files/frontlib/events.h
--- a/project_files/frontlib/events.h	Sat Jun 02 22:54:09 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,14 +0,0 @@
-/*
- * events.h
- *
- *  Created on: 01.06.2012
- *      Author: simmax
- */
-
-#ifndef EVENTS_H_
-#define EVENTS_H_
-
-
-
-
-#endif /* EVENTS_H_ */
diff -r b66eef8c8092 -r 906e72caea7b project_files/frontlib/frontlib.c
--- a/project_files/frontlib/frontlib.c	Sat Jun 02 22:54:09 2012 +0200
+++ b/project_files/frontlib/frontlib.c	Sun Jun 03 01:24:18 2012 +0200
@@ -1,6 +1,6 @@
 #include "frontlib.h"
 #include "logging.h"
-#include "nonblocksockets.h"
+#include "socket.h"
 #include "ipcconn.h"
 
 #include <SDL.h>
@@ -29,13 +29,10 @@
 		return -1;
 	}
 
-	flib_ipcconn_init();
 	return 0;
 }
 
 void flib_quit() {
-	flib_ipcconn_quit();
-
 	SDLNet_Quit();
 	if(!(flib_initflags | FRONTLIB_SDL_ALREADY_INITIALIZED)) {
 		SDL_Quit();
@@ -43,34 +40,34 @@
 }
 
 int main(int argc, char *argv[]) {
-	flib_init(FRONTLIB_SDL_ALREADY_INITIALIZED);
-	flib_ipcconn_start(true);
+	flib_init(0);
+
+	flib_ipcconn ipc = flib_ipcconn_create(true, "Medo42");
 	char data[256];
-	while(flib_ipcconn_state() != IPC_NOT_CONNECTED) {
-		flib_ipcconn_tick();
-		int size = flib_ipcconn_recv_message(data);
+	while(flib_ipcconn_state(ipc) != IPC_NOT_CONNECTED) {
+		flib_ipcconn_tick(ipc);
+		int size = flib_ipcconn_recv_message(ipc, data);
 		if(size>0) {
 			data[size]=0;
-			flib_log_i("IPC IN: %s", data);
 			switch(data[0]) {
 			case 'C':
 				flib_log_i("Sending config...");
-				flib_ipcconn_send_messagestr("TL");
-				flib_ipcconn_send_messagestr("eseed loremipsum");
-				flib_ipcconn_send_messagestr("escript Missions/Training/Basic_Training_-_Bazooka.lua");
+				flib_ipcconn_send_messagestr(ipc, "TL");
+				flib_ipcconn_send_messagestr(ipc, "eseed loremipsum");
+				flib_ipcconn_send_messagestr(ipc, "escript Missions/Training/Basic_Training_-_Bazooka.lua");
 				break;
 			case '?':
 				flib_log_i("Sending pong...");
-				flib_ipcconn_send_messagestr("!");
+				flib_ipcconn_send_messagestr(ipc, "!");
 				break;
 			case 'Q':
 				flib_log_i("Game interrupted.");
 				break;
 			case 'q':
 				flib_log_i("Game finished.");
-				flib_constbuffer demobuf = flib_ipcconn_getdemo();
+				flib_constbuffer demobuf = flib_ipcconn_getdemo(ipc);
 				flib_log_i("Writing demo (%u bytes)...", demobuf.size);
-				FILE *file = fopen("testdemo.dem", "w");
+				FILE *file = fopen("testdemo.dem", "wb");
 				fwrite(demobuf.data, 1, demobuf.size, file);
 				fclose(file);
 				file = NULL;
@@ -82,6 +79,7 @@
 		}
 	}
 	flib_log_i("IPC connection lost.");
+	flib_ipcconn_destroy(&ipc);
 	flib_quit();
 	return 0;
 }
diff -r b66eef8c8092 -r 906e72caea7b project_files/frontlib/ipcconn.c
--- a/project_files/frontlib/ipcconn.c	Sat Jun 02 22:54:09 2012 +0200
+++ b/project_files/frontlib/ipcconn.c	Sun Jun 03 01:24:18 2012 +0200
@@ -1,97 +1,91 @@
 #include "ipcconn.h"
 #include "logging.h"
-#include "nonblocksockets.h"
+#include "socket.h"
 
-#include <SDL_net.h>
-#include <time.h>
 #include <string.h>
 #include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
 
-static TCPsocket ipcListenSocket;
-static NonBlockSocket ipcConnSocket;
+typedef struct _flib_ipcconn {
+	char playerName[256];
+
+	uint8_t readBuffer[256];
+	int readBufferSize;
 
-static uint8_t ipcReadBuffer[256];
-static int ipcReadBufferSize;
+	flib_acceptor acceptor;
+	uint16_t port;
 
-static flib_vector demoBuffer;
-static char localPlayerName[255];
+	flib_tcpsocket sock;
+	flib_vector demoBuffer;
+} _flib_ipcconn;
+
+flib_ipcconn flib_ipcconn_create(bool recordDemo, const char *localPlayerName) {
+	flib_ipcconn result = malloc(sizeof(_flib_ipcconn));
+	flib_acceptor acceptor = flib_acceptor_create(0);
 
-void flib_ipcconn_init() {
-	ipcListenSocket = NULL;
-	ipcConnSocket = NULL;
-	ipcReadBufferSize = 0;
-	demoBuffer=NULL;
-	strncpy(localPlayerName, "Local Player", 255);
-}
+	if(!result || !acceptor) {
+		free(result);
+		flib_acceptor_close(&acceptor);
+		return NULL;
+	}
+
+	result->acceptor = acceptor;
+	result->sock = NULL;
+	result->readBufferSize = 0;
+	result->port = flib_acceptor_listenport(acceptor);
 
-void flib_ipcconn_quit() {
-	flib_vector_destroy(&demoBuffer);
-	flib_ipcconn_close();
+	if(localPlayerName) {
+		strncpy(result->playerName, localPlayerName, 255);
+	} else {
+		strncpy(result->playerName, "Player", 255);
+	}
+
+	if(recordDemo) {
+		result->demoBuffer = flib_vector_create();
+	}
+
+	flib_log_i("Started listening for IPC connections on port %u", result->port);
+	return result;
 }
 
-int flib_ipcconn_start(bool recordDemo) {
-	if(ipcListenSocket || ipcConnSocket) {
-		flib_log_e("flib_ipcconn_listen: Already listening or connected.");
-		return -1;
-	}
-	IPaddress addr;
-	addr.host = INADDR_ANY;
-
-	/* SDL_net does not seem to have a way to listen on a random unused port
-	   and find out which port that is, so let's try to find one ourselves. */
-	// TODO: Is socket binding fail-fast on all platforms?
-	srand(time(NULL));
-	rand();
-	for(int i=0; i<1000; i++) {
-		// IANA suggests using ports in the range 49152-65535 for things like this
-		int ipcPort = 49152+(rand()%(65535-49152));
-		SDLNet_Write16(ipcPort, &addr.port);
-		ipcListenSocket = SDLNet_TCP_Open(&addr);
-		if(!ipcListenSocket) {
-			flib_log_w("Failed to start an IPC listening socket on port %i: %s", ipcPort, SDLNet_GetError());
-		} else {
-			flib_log_i("Listening for IPC connections on port %i.", ipcPort);
-			if(recordDemo) {
-				flib_vector_destroy(&demoBuffer);
-				demoBuffer = flib_vector_create();
-			}
-			return ipcPort;
-		}
-	}
-	flib_log_e("Unable to find a free port for IPC.");
-	return -1;
+uint16_t flib_ipcconn_port(flib_ipcconn ipc) {
+	return ipc->port;
 }
 
-void flib_ipcconn_close() {
-	if(ipcListenSocket) {
-		SDLNet_TCP_Close(ipcListenSocket);
-		ipcListenSocket = NULL;
+void flib_ipcconn_destroy(flib_ipcconn *ipcptr) {
+	if(!ipcptr || !*ipcptr) {
+		return;
 	}
-	flib_nbsocket_close(&ipcConnSocket);
-	ipcReadBufferSize = 0;
+	flib_ipcconn ipc = *ipcptr;
+	flib_acceptor_close(&ipc->acceptor);
+	flib_socket_close(&ipc->sock);
+	flib_vector_destroy(&ipc->demoBuffer);
+	free(ipc);
+	*ipcptr = NULL;
 }
 
-IpcConnState flib_ipcconn_state() {
-	if(ipcConnSocket) {
+IpcConnState flib_ipcconn_state(flib_ipcconn ipc) {
+	if(ipc && ipc->sock) {
 		return IPC_CONNECTED;
-	} else if(ipcListenSocket) {
+	} else if(ipc && ipc->acceptor) {
 		return IPC_LISTENING;
 	} else {
 		return IPC_NOT_CONNECTED;
 	}
 }
 
-static void demo_record(const void *data, size_t len) {
-	if(demoBuffer) {
-		if(flib_vector_append(demoBuffer, data, len) < len) {
+static void demo_record(flib_ipcconn ipc, const void *data, size_t len) {
+	if(ipc->demoBuffer) {
+		if(flib_vector_append(ipc->demoBuffer, data, len) < len) {
 			// Out of memory, fail demo recording
-			flib_vector_destroy(&demoBuffer);
+			flib_vector_destroy(&ipc->demoBuffer);
 		}
 	}
 }
 
-static void demo_record_from_engine(const uint8_t *message) {
-	if(!demoBuffer || message[0]==0) {
+static void demo_record_from_engine(flib_ipcconn ipc, const uint8_t *message) {
+	if(!ipc->demoBuffer || message[0]==0) {
 		return;
 	}
 	if(strchr("?CEiQqHb", message[1])) {
@@ -110,12 +104,12 @@
 			char converted[257];
 			bool memessage = message[0] >= 7 && !memcmp(message+2, "/me ", 4);
 			const char *template = memessage ? "s\x02* %s %s  " : "s\x01%s: %s  ";
-			int size = snprintf(converted+1, 256, template, localPlayerName, chatMsg);
+			int size = snprintf(converted+1, 256, template, ipc->playerName, chatMsg);
 			converted[0] = size>255 ? 255 : size;
-			demo_record(converted, converted[0]+1);
+			demo_record(ipc, converted, converted[0]+1);
 		}
 	} else {
-		demo_record(message, message[0]+1);
+		demo_record(ipc, message, message[0]+1);
 	}
 }
 
@@ -123,41 +117,53 @@
  * Receive a single message and copy it into the data buffer.
  * Returns the length of the received message, -1 when nothing is received.
  */
-int flib_ipcconn_recv_message(void *data) {
-	flib_ipcconn_tick();
+int flib_ipcconn_recv_message(flib_ipcconn ipc, void *data) {
+	flib_ipcconn_tick(ipc);
 
-	if(ipcConnSocket) {
-		int size = flib_nbsocket_recv(ipcConnSocket, ipcReadBuffer+ipcReadBufferSize, sizeof(ipcReadBuffer)-ipcReadBufferSize);
+	if(ipc->sock) {
+		int size = flib_socket_nbrecv(ipc->sock, ipc->readBuffer+ipc->readBufferSize, sizeof(ipc->readBuffer)-ipc->readBufferSize);
 		if(size>=0) {
-			ipcReadBufferSize += size;
+			ipc->readBufferSize += size;
 		} else {
-			flib_nbsocket_close(&ipcConnSocket);
+			flib_socket_close(&ipc->sock);
 		}
 	}
 
-	int msgsize = ipcReadBuffer[0];
-	if(ipcReadBufferSize > msgsize) {
-		demo_record_from_engine(ipcReadBuffer);
-		memcpy(data, ipcReadBuffer+1, msgsize);
-		memmove(ipcReadBuffer, ipcReadBuffer+msgsize+1, ipcReadBufferSize-(msgsize+1));
-		ipcReadBufferSize -= (msgsize+1);
+	int msgsize = ipc->readBuffer[0];
+	if(ipc->readBufferSize > msgsize) {
+		demo_record_from_engine(ipc, ipc->readBuffer);
+		memcpy(data, ipc->readBuffer+1, msgsize);
+		memmove(ipc->readBuffer, ipc->readBuffer+msgsize+1, ipc->readBufferSize-(msgsize+1));
+		ipc->readBufferSize -= (msgsize+1);
 		return msgsize;
-	} else if(!ipcConnSocket && ipcReadBufferSize>0) {
-		flib_log_w("Last message from engine data stream is incomplete (received %u of %u bytes)", ipcReadBufferSize-1, msgsize);
-		ipcReadBufferSize = 0;
+	} else if(!ipc->sock && ipc->readBufferSize>0) {
+		flib_log_w("Last message from engine data stream is incomplete (received %u of %u bytes)", ipc->readBufferSize-1, msgsize);
+		ipc->readBufferSize = 0;
 		return -1;
 	} else {
 		return -1;
 	}
 }
 
-int flib_ipcconn_send_message(void *data, size_t len) {
-	flib_ipcconn_tick();
+int flib_ipcconn_send_raw(flib_ipcconn ipc, void *data, size_t len) {
+	flib_ipcconn_tick(ipc);
 
-	if(!ipcConnSocket) {
+	if(!ipc->sock) {
 		flib_log_w("flib_ipcconn_send_message: Not connected.");
 		return -1;
 	}
+
+	if(flib_socket_send(ipc->sock, data, len) == len) {
+		demo_record(ipc, data, len);
+		return 0;
+	} else {
+		flib_log_w("Failed or incomplete ICP write: engine connection lost.");
+		flib_socket_close(&ipc->sock);
+		return -1;
+	}
+}
+
+int flib_ipcconn_send_message(flib_ipcconn ipc, void *data, size_t len) {
 	if(len>255) {
 		flib_log_e("Attempt to send too much data to the engine in a single message.");
 		return -1;
@@ -166,26 +172,19 @@
 	uint8_t sendbuf[256];
 	sendbuf[0] = len;
 	memcpy(sendbuf+1, data, len);
-	if(flib_nbsocket_blocksend(ipcConnSocket, sendbuf, len+1) == len+1) {
-		demo_record(sendbuf, len+1);
-		return 0;
-	} else {
-		flib_log_w("Failed or incomplete ICP write: engine connection lost.");
-		flib_nbsocket_close(&ipcConnSocket);
-		return -1;
-	}
+
+	return flib_ipcconn_send_raw(ipc, sendbuf, len+1);
 }
 
-int flib_ipcconn_send_messagestr(char *data) {
-	return flib_ipcconn_send_message(data, strlen(data));
+int flib_ipcconn_send_messagestr(flib_ipcconn ipc, char *data) {
+	return flib_ipcconn_send_message(ipc, data, strlen(data));
 }
 
-void flib_ipcconn_tick() {
-	if(!ipcConnSocket && ipcListenSocket) {
-		ipcConnSocket = flib_nbsocket_accept(ipcListenSocket, true);
-		if(ipcConnSocket) {
-			SDLNet_TCP_Close(ipcListenSocket);
-			ipcListenSocket = NULL;
+void flib_ipcconn_tick(flib_ipcconn ipc) {
+	if(!ipc->sock && ipc->acceptor) {
+		ipc->sock = flib_socket_accept(ipc->acceptor, true);
+		if(ipc->sock) {
+			flib_acceptor_close(&ipc->acceptor);
 		}
 	}
 }
@@ -201,20 +200,20 @@
 	}
 }
 
-flib_constbuffer flib_ipcconn_getdemo() {
-	if(!demoBuffer) {
+flib_constbuffer flib_ipcconn_getdemo(flib_ipcconn ipc) {
+	if(!ipc->demoBuffer) {
 		flib_constbuffer result = {NULL, 0};
 		return result;
 	}
-	replace_gamemode(flib_vector_as_buffer(demoBuffer), 'D');
-	return flib_vector_as_constbuffer(demoBuffer);
+	replace_gamemode(flib_vector_as_buffer(ipc->demoBuffer), 'D');
+	return flib_vector_as_constbuffer(ipc->demoBuffer);
 }
 
-flib_constbuffer flib_ipcconn_getsave() {
-	if(!demoBuffer) {
+flib_constbuffer flib_ipcconn_getsave(flib_ipcconn ipc) {
+	if(!ipc->demoBuffer) {
 		flib_constbuffer result = {NULL, 0};
 		return result;
 	}
-	replace_gamemode(flib_vector_as_buffer(demoBuffer), 'S');
-	return flib_vector_as_constbuffer(demoBuffer);
+	replace_gamemode(flib_vector_as_buffer(ipc->demoBuffer), 'S');
+	return flib_vector_as_constbuffer(ipc->demoBuffer);
 }
diff -r b66eef8c8092 -r 906e72caea7b project_files/frontlib/ipcconn.h
--- a/project_files/frontlib/ipcconn.h	Sat Jun 02 22:54:09 2012 +0200
+++ b/project_files/frontlib/ipcconn.h	Sun Jun 03 01:24:18 2012 +0200
@@ -12,42 +12,35 @@
 
 typedef enum {IPC_NOT_CONNECTED, IPC_LISTENING, IPC_CONNECTED} IpcConnState;
 
-/**
- * Called by flib_init(). Initialize everything related to ipc.
- */
-void flib_ipcconn_init();
+struct _flib_ipcconn;
+typedef struct _flib_ipcconn *flib_ipcconn;
 
 /**
- * Called by flib_quit(). Free resources and shut down.
- */
-void flib_ipcconn_quit();
-
-/**
- * Start listening for a connection from the engine. The system has to be in state
- * IPC_NOT_CONNECTED when calling this function, and will be in state IPC_LISTENING
- * if the function returns successfully.
+ * Start an engine connection by listening on a random port. The selected port can
+ * be queried with flib_ipcconn_port and has to be passed to the engine.
  *
  * The parameter "recordDemo" can be used to control whether demo recording should
- * be enabled for this connection.
+ * be enabled for this connection. The localPlayerName is needed for demo
+ * recording purposes.
  *
- * Returns the port we started listening on, or a negative value if there is an error.
+ * Returns NULL on error. Destroy the created object with flib_ipcconn_destroy.
  *
- * We stop listening once a connection has been established, so if you want to start
- * the engine again and talk to it you need to call this function again after the old
- * connection is closed.
+ * We stop accepting new connections once a connection has been established, so you
+ * need to create a new ipcconn in order to start a new connection.
  */
-int flib_ipcconn_start(bool recordDemo);
+flib_ipcconn flib_ipcconn_create(bool recordDemo, const char *localPlayerName);
+
+uint16_t flib_ipcconn_port(flib_ipcconn ipc);
 
 /**
- * Close the current IPC connection and/or stop listening for an incoming one.
- * This also discards all unread messages.
+ * Free resources, close sockets, and set the pointer to NULL.
  */
-void flib_ipcconn_close();
+void flib_ipcconn_destroy(flib_ipcconn *ipcptr);
 
 /**
  * Determine the current connection state
  */
-IpcConnState flib_ipcconn_state();
+IpcConnState flib_ipcconn_state(flib_ipcconn ipc);
 
 /**
  * Receive a single message (up to 255 bytes) and copy it into the data buffer.
@@ -58,7 +51,9 @@
  * no further message is returned, to ensure you see all messages that were sent
  * before the connection closed.
  */
-int flib_ipcconn_recv_message(void *data);
+int flib_ipcconn_recv_message(flib_ipcconn ipc, void *data);
+
+int flib_ipcconn_send_raw(flib_ipcconn ipc, void *data, size_t len);
 
 /**
  * Write a single message (up to 255 bytes) to the engine. This call blocks until the
@@ -67,43 +62,43 @@
  * Calling this function in a state other than IPC_CONNECTED will fail immediately.
  * Returns a negative value on failure.
  */
-int flib_ipcconn_send_message(void *data, size_t len);
+int flib_ipcconn_send_message(flib_ipcconn ipc, void *data, size_t len);
 
 /**
  * Convenience function for sending a 0-delimited string.
  */
-int flib_ipcconn_send_messagestr(char *data);
+int flib_ipcconn_send_messagestr(flib_ipcconn ipc, char *data);
 
 /**
  * Call regularly to allow background work to proceed
  */
-void flib_ipcconn_tick();
+void flib_ipcconn_tick(flib_ipcconn ipc);
 
 /**
- * Get a demo record of the last connection. This should be called after
+ * Get a demo record of the connection. This should be called after
  * the connection is closed and all messages have been received.
  *
- * If demo recording was not enabled in the last call to flib_ipcconn_start(),
- * or if the recording failed for some reason, the buffer will be empty.
+ * If demo recording was not enabled, or if the recording failed for some reason,
+ * the buffer will be empty.
  *
- * The buffer is only valid until the next call to flib_ipcconn_start() or
- * a call to flib_ipcconn_getsave() (save and demo records have some minor
- * differences, and those are performed directly on the buffer before returning it).
+ * The buffer is only valid until a call to flib_ipcconn_getsave(), since save
+ * and demo records have some minor differences, and those are performed directly
+ * on the buffer before returning it).
  */
-flib_constbuffer flib_ipcconn_getdemo();
+flib_constbuffer flib_ipcconn_getdemo(flib_ipcconn ipc);
 
 /**
- * Get a savegame record of the last connection. This should be called after
+ * Get a savegame record of the connection. This should be called after
  * the connection is closed and all messages have been received.
  *
- * If demo recording was not enabled in the last call to flib_ipcconn_start(),
- * or if the recording failed for some reason, the buffer will be empty.
+ * If demo recording was not enabled, or if the recording failed for some reason,
+ * the buffer will be empty.
  *
- * The buffer is only valid until the next call to flib_ipcconn_start() or
- * a call to flib_ipcconn_getdemo() (save and demo records have some minor
- * differences, and those are performed directly on the buffer before returning it).
+ * The buffer is only valid until a call to flib_ipcconn_getdemo(), since save
+ * and demo records have some minor differences, and those are performed directly
+ * on the buffer before returning it).
  */
-flib_constbuffer flib_ipcconn_getsave();
+flib_constbuffer flib_ipcconn_getsave(flib_ipcconn ipc);
 
 #endif /* IPCCONN_H_ */
 
diff -r b66eef8c8092 -r 906e72caea7b project_files/frontlib/nonblocksockets.c
--- a/project_files/frontlib/nonblocksockets.c	Sat Jun 02 22:54:09 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,76 +0,0 @@
-#include "nonblocksockets.h"
-#include "logging.h"
-#include <stdlib.h>
-
-static uint32_t get_peer_ip(TCPsocket sock) {
-	IPaddress *addr = SDLNet_TCP_GetPeerAddress(sock);
-	return SDLNet_Read32(&addr->host);
-}
-
-static bool connection_is_local(TCPsocket sock) {
-	return get_peer_ip(sock) == (uint32_t)((127UL<<24)+1); // 127.0.0.1
-}
-
-void flib_nbsocket_close(NonBlockSocket *nbsockptr) {
-	NonBlockSocket nbsock = *nbsockptr;
-	if(nbsock!=NULL) {
-		SDLNet_DelSocket(nbsock->sockset, (SDLNet_GenericSocket)nbsock->sock);
-		SDLNet_TCP_Close(nbsock->sock);
-		SDLNet_FreeSocketSet(nbsock->sockset);
-	}
-	free(nbsock);
-	*nbsockptr = NULL;
-}
-
-NonBlockSocket flib_nbsocket_accept(TCPsocket listensocket, bool localOnly) {
-	NonBlockSocket result = NULL;
-	if(!listensocket) {
-		flib_log_e("Attempt to accept a connection on a NULL socket.");
-		return NULL;
-	}
-	while(result==NULL) {
-		TCPsocket sock = SDLNet_TCP_Accept(listensocket);
-		if(!sock) {
-			// No incoming connections
-			return NULL;
-		}
-		if(localOnly && !connection_is_local(sock)) {
-			flib_log_i("Rejected nonlocal connection attempt from %s", flib_format_ip(get_peer_ip(sock)));
-			SDLNet_TCP_Close(sock);
-		} else {
-			result = malloc(sizeof(_NonBlockSocket));
-			if(result==NULL) {
-				flib_log_e("Out of memory!");
-				SDLNet_TCP_Close(sock);
-				return NULL;
-			}
-			result->sock = sock;
-			result->sockset = SDLNet_AllocSocketSet(1);
-			if(result->sockset==NULL) {
-				flib_log_e("Out of memory!");
-				SDLNet_TCP_Close(sock);
-				free(result);
-				return NULL;
-			}
-			SDLNet_AddSocket(result->sockset, (SDLNet_GenericSocket)result->sock);
-		}
-	}
-	return result;
-}
-
-int flib_nbsocket_recv(NonBlockSocket sock, void *data, int maxlen) {
-	if(!sock) {
-		flib_log_e("Attempt to receive on a NULL socket.");
-		return -1;
-	}
-	int readySockets = SDLNet_CheckSockets(sock->sockset, 0);
-	if(readySockets>0) {
-		int size = SDLNet_TCP_Recv(sock->sock, data, maxlen);
-		return size>0 ? size : -1;
-	} else if(readySockets==0) {
-		return 0;
-	} else {
-		flib_log_e("Error in select system call: %s", SDLNet_GetError());
-		return -1;
-	}
-}
diff -r b66eef8c8092 -r 906e72caea7b project_files/frontlib/nonblocksockets.h
--- a/project_files/frontlib/nonblocksockets.h	Sat Jun 02 22:54:09 2012 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,51 +0,0 @@
-/*
- * nonblocksockets.h
- *
- *  Created on: 31.05.2012
- *      Author: simmax
- */
-
-#ifndef NONBLOCKSOCKETS_H_
-#define NONBLOCKSOCKETS_H_
-
-#include <SDL_net.h>
-#include <stdbool.h>
-
-typedef struct {
-	TCPsocket sock;
-	SDLNet_SocketSet sockset;
-} _NonBlockSocket;
-
-typedef _NonBlockSocket *NonBlockSocket;
-
-/**
- * Close the indicated socket, free its memory and set it to NULL.
- * If the socket is already NULL, nothing happens.
- */
-void flib_nbsocket_close(NonBlockSocket *socket);
-
-/**
- * Try to accept a connection from a listening socket.
- * if localOnly is true, this will only accept connections which came from 127.0.0.1
- * Returns NULL if nothing can be accepted.
- */
-NonBlockSocket flib_nbsocket_accept(TCPsocket listensocket, bool localOnly);
-
-/**
- * Attempt to receive up to maxlen bytes from the socket, but does not
- * block if nothing is available.
- * Returns the ammount of data received, 0 if there was nothing to receive,
- * or a negative number if the connection was closed or an error occurred.
- */
-int flib_nbsocket_recv(NonBlockSocket sock, void *data, int maxlen);
-
-/**
- * We can't do a nonblocking send over SDL_net, so this function just forwards
- * to SDLNet_TCP_Send for convenience, which blocks until all data is sent or an
- * error occurs. The ammount of data actually sent is returned, negative value on error.
- */
-static inline int flib_nbsocket_blocksend(NonBlockSocket sock, void *data, int len) {
-	return SDLNet_TCP_Send(sock->sock, data, len);
-}
-
-#endif /* NONBLOCKSOCKETS_H_ */
diff -r b66eef8c8092 -r 906e72caea7b project_files/frontlib/socket.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/project_files/frontlib/socket.c	Sun Jun 03 01:24:18 2012 +0200
@@ -0,0 +1,149 @@
+#include "socket.h"
+#include "logging.h"
+#include <stdlib.h>
+#include <SDL_net.h>
+#include <time.h>
+
+typedef struct _flib_tcpsocket {
+	TCPsocket sock;
+	SDLNet_SocketSet sockset;
+} _flib_tcpsocket;
+
+typedef struct _flib_acceptor {
+	TCPsocket sock;
+	uint16_t port;
+} _flib_acceptor;
+
+static uint32_t get_peer_ip(TCPsocket sock) {
+	IPaddress *addr = SDLNet_TCP_GetPeerAddress(sock);
+	return SDLNet_Read32(&addr->host);
+}
+
+static bool connection_is_local(TCPsocket sock) {
+	return get_peer_ip(sock) == (uint32_t)((127UL<<24)+1); // 127.0.0.1
+}
+
+flib_acceptor flib_acceptor_create(uint16_t port) {
+	flib_acceptor result = malloc(sizeof(_flib_acceptor));
+	if(!result) {
+		flib_log_e("Out of memory!");
+		return NULL;
+	}
+
+	IPaddress addr;
+	addr.host = INADDR_ANY;
+
+	if(port > 0) {
+		result->port = port;
+		SDLNet_Write16(port, &addr.port);
+		result->sock = SDLNet_TCP_Open(&addr);
+		if(result->sock) {
+			return result;
+		} else {
+			flib_log_e("Unable to listen on port %u: %s", port, SDLNet_GetError());
+			free(result);
+			return NULL;
+		}
+	} else {
+		/* SDL_net does not seem to have a way to listen on a random unused port
+		   and find out which port that is, so let's try to find one ourselves. */
+		// TODO: Is socket binding fail-fast on all platforms?
+		srand(time(NULL));
+		rand();
+		for(int i=0; i<1000; i++) {
+			// IANA suggests using ports in the range 49152-65535 for things like this
+			result->port = 49152+(rand()%(65535-49152));
+			SDLNet_Write16(result->port, &addr.port);
+			result->sock = SDLNet_TCP_Open(&addr);
+			if(result->sock) {
+				return result;
+			} else {
+				flib_log_i("Unable to listen on port %u: %s", result->port, SDLNet_GetError());
+			}
+		}
+		flib_log_e("Unable to listen on a random unused port.");
+		free(result);
+		return NULL;
+	}
+}
+
+uint16_t flib_acceptor_listenport(flib_acceptor acceptor) {
+	return acceptor->port;
+}
+
+void flib_acceptor_close(flib_acceptor *acceptorptr) {
+	if(acceptorptr == NULL || *acceptorptr == NULL) {
+		return;
+	}
+	SDLNet_TCP_Close((*acceptorptr)->sock);
+	free(*acceptorptr);
+	*acceptorptr = NULL;
+}
+
+flib_tcpsocket flib_socket_accept(flib_acceptor acceptor, bool localOnly) {
+	flib_tcpsocket result = NULL;
+	if(!acceptor) {
+		return NULL;
+	}
+	while(result==NULL) {
+		TCPsocket sock = SDLNet_TCP_Accept(acceptor->sock);
+		if(!sock) {
+			// No incoming connections
+			return NULL;
+		}
+		if(localOnly && !connection_is_local(sock)) {
+			flib_log_i("Rejected nonlocal connection attempt from %s", flib_format_ip(get_peer_ip(sock)));
+			SDLNet_TCP_Close(sock);
+		} else {
+			result = malloc(sizeof(_flib_tcpsocket));
+			if(result==NULL) {
+				flib_log_e("Out of memory!");
+				SDLNet_TCP_Close(sock);
+				return NULL;
+			}
+			result->sock = sock;
+			result->sockset = SDLNet_AllocSocketSet(1);
+			if(result->sockset==NULL) {
+				flib_log_e("Out of memory!");
+				SDLNet_TCP_Close(sock);
+				free(result);
+				return NULL;
+			}
+			SDLNet_AddSocket(result->sockset, (SDLNet_GenericSocket)result->sock);
+		}
+	}
+	return result;
+}
+
+void flib_socket_close(flib_tcpsocket *sockptr) {
+	if(sockptr==NULL || *sockptr == NULL) {
+		return;
+	}
+	flib_tcpsocket sock = *sockptr;
+	SDLNet_DelSocket(sock->sockset, (SDLNet_GenericSocket)sock->sock);
+	SDLNet_TCP_Close(sock->sock);
+	SDLNet_FreeSocketSet(sock->sockset);
+	free(sock);
+	*sockptr = NULL;
+}
+
+int flib_socket_nbrecv(flib_tcpsocket sock, void *data, int maxlen) {
+	if(!sock) {
+		flib_log_e("Attempt to receive on a NULL socket.");
+		return -1;
+	}
+	int readySockets = SDLNet_CheckSockets(sock->sockset, 0);
+	if(readySockets>0) {
+		int size = SDLNet_TCP_Recv(sock->sock, data, maxlen);
+		return size>0 ? size : -1;
+	} else if(readySockets==0) {
+		return 0;
+	} else {
+		flib_log_e("Error in select system call: %s", SDLNet_GetError());
+		return -1;
+	}
+}
+
+int flib_socket_send(flib_tcpsocket sock, void *data, int len) {
+	return SDLNet_TCP_Send(sock->sock, data, len);
+}
diff -r b66eef8c8092 -r 906e72caea7b project_files/frontlib/socket.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/project_files/frontlib/socket.h	Sun Jun 03 01:24:18 2012 +0200
@@ -0,0 +1,72 @@
+/*
+ * Sockets for TCP networking.
+ *
+ * This layer offers some functionality over what SDL_net offers directly: listening
+ * sockets (called acceptors here) can be bound to port 0, which will make them listen
+ * on a random unused port, if one can be found. To support this feature, you can also
+ * query the local port that an acceptor is listening on.
+ *
+ * Further, we support nonblocking reads and writes here. The writes are buffered (TODO),
+ * so that all data will be accepted, and you can configure a maximum buffer size
+ * where the connection will be terminated.
+ *
+ * In order to ensure buffered data is actually sent out, you should regularly call
+ * the tick function on your sockets.
+ */
+
+#ifndef SOCKET_H_
+#define SOCKET_H_
+
+#include <stdbool.h>
+#include <stdint.h>
+
+struct _flib_tcpsocket;
+typedef struct _flib_tcpsocket *flib_tcpsocket;
+
+struct _flib_acceptor;
+typedef struct _flib_acceptor *flib_acceptor;
+
+/**
+ * Create a new acceptor which will listen for incoming TCP connections
+ * on the given port. If port is 0, this will listen on a random
+ * unused port which can then be queried with flib_acceptor_listenport.
+ *
+ * Can return NULL on error.
+ */
+flib_acceptor flib_acceptor_create(uint16_t port);
+
+/**
+ * Return the port on which the acceptor is listening.
+ */
+uint16_t flib_acceptor_listenport(flib_acceptor acceptor);
+
+/**
+ * Close the acceptor, free its memory and set it to NULL.
+ * If the acceptor is already NULL, nothing happens.
+ */
+void flib_acceptor_close(flib_acceptor *acceptorptr);
+
+/**
+ * Try to accept a connection from an acceptor (listening socket).
+ * if localOnly is true, this will only accept connections which came from 127.0.0.1
+ * Returns NULL if nothing can be accepted.
+ */
+flib_tcpsocket flib_socket_accept(flib_acceptor acceptor, bool localOnly);
+
+/**
+ * Close the socket, free its memory and set it to NULL.
+ * If the socket is already NULL, nothing happens.
+ */
+void flib_socket_close(flib_tcpsocket *socket);
+
+/**
+ * Attempt to receive up to maxlen bytes from the socket, but does not
+ * block if nothing is available.
+ * Returns the ammount of data received, 0 if there was nothing to receive,
+ * or a negative number if the connection was closed or an error occurred.
+ */
+int flib_socket_nbrecv(flib_tcpsocket sock, void *data, int maxlen);
+
+int flib_socket_send(flib_tcpsocket sock, void *data, int len);
+
+#endif /* SOCKET_H_ */