--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/frontlib/frontlib.c Thu May 31 00:35:06 2012 +0200
@@ -0,0 +1,219 @@
+#include "frontlib.h"
+#include "logging.h"
+
+#include <SDL.h>
+#include <SDL_net.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <time.h>
+
+static int flib_initflags;
+static TCPsocket ipcListenSocket;
+static int ipcPort;
+static uint8_t ipcReadBuffer[256];
+static int ipcReadBufferSize;
+
+static TCPsocket ipcConnSocket;
+static SDLNet_SocketSet ipcConnSocketSet;
+
+static TCPsocket serverConnSocket;
+static SDLNet_SocketSet serverConnSocketSet;
+
+
+#include <time.h>
+void flib_logtime() {
+ time_t timer;
+ char buffer[25];
+ struct tm* tm_info;
+
+ time(&timer);
+ tm_info = localtime(&timer);
+
+ strftime(buffer, 25, "%H:%M:%S", tm_info);
+ printf("%s", buffer);
+}
+
+int flib_init(int flags) {
+ flib_initflags = flags;
+ ipcListenSocket = NULL;
+ ipcConnSocket = NULL;
+ serverConnSocket = NULL;
+ ipcReadBufferSize = 0;
+
+ if(!(flib_initflags | FRONTLIB_SDL_ALREADY_INITIALIZED)) {
+ if(SDL_Init(0)==-1) {
+ flib_log_e("Error in SDL_Init: %s\n", SDL_GetError());
+ return -1;
+ }
+ }
+
+ if(SDLNet_Init()==-1) {
+ flib_log_e("Error in SDLNet_Init: %s\n", SDLNet_GetError());
+ if(!(flib_initflags | FRONTLIB_SDL_ALREADY_INITIALIZED)) {
+ SDL_Quit();
+ }
+ return -1;
+ }
+
+ ipcConnSocketSet = SDLNet_AllocSocketSet(1);
+ serverConnSocketSet = SDLNet_AllocSocketSet(1);
+ return 0;
+}
+
+/**
+ * Free resources associated with the library. Call this function once
+ * the library is no longer needed. You can re-initialize the library by calling
+ * flib_init again.
+ */
+void flib_quit() {
+ // TODO: Send a "quit" message first?
+ SDLNet_FreeSocketSet(ipcConnSocketSet);
+ SDLNet_FreeSocketSet(serverConnSocketSet);
+
+ if(ipcListenSocket) {
+ SDLNet_TCP_Close(ipcListenSocket);
+ ipcListenSocket = NULL;
+ }
+ if(ipcConnSocket) {
+ SDLNet_TCP_Close(ipcConnSocket);
+ ipcConnSocket = NULL;
+ }
+ if(serverConnSocket) {
+ SDLNet_TCP_Close(serverConnSocket);
+ serverConnSocket = NULL;
+ }
+
+ SDLNet_Quit();
+ if(!(flib_initflags | FRONTLIB_SDL_ALREADY_INITIALIZED)) {
+ SDL_Quit();
+ }
+}
+
+/**
+ * Start listening for a connection from the engine, if we are not listening already.
+ * Returns the port we are listening on, which needs to be passed to the engine,
+ * or -1 if there is an error.
+ *
+ * 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.
+ */
+int flib_ipc_listen() {
+ if(ipcListenSocket) {
+ return ipcPort;
+ }
+ 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
+ ipcPort = 49152+(rand()%(65535-49152));
+ SDLNet_Write16(ipcPort, &addr.port);
+ flib_log_i("Attempting to listen on port %i...\n", ipcPort);
+ ipcListenSocket = SDLNet_TCP_Open(&addr);
+ if(!ipcListenSocket) {
+ flib_log_w("Unable to listen on port %i: %s\n", ipcPort, SDLNet_GetError());
+ } else {
+ flib_log_i("ok.\n");
+ return ipcPort;
+ }
+ }
+ flib_log_e("Unable to find a usable IPC port.");
+ return -1;
+}
+
+void flib_accept_ipc() {
+ if(!ipcListenSocket) {
+ flib_log_e("Attempt to accept IPC connection while not listening.");
+ return;
+ }
+ do {
+ TCPsocket sock = SDLNet_TCP_Accept(ipcListenSocket);
+ if(!sock) {
+ // No incoming connections
+ return;
+ }
+ // Check if it is a local connection
+ IPaddress *addr = SDLNet_TCP_GetPeerAddress(sock);
+ uint32_t numip = SDLNet_Read32(&addr->host);
+ if(numip != (uint32_t)((127UL<<24)+1)) { // 127.0.0.1
+ flib_log_w("Rejected IPC connection attempt from %s\n", flib_format_ip(numip));
+ } else {
+ ipcConnSocket = sock;
+ SDLNet_AddSocket(ipcConnSocketSet, (SDLNet_GenericSocket)ipcConnSocket);
+ SDLNet_TCP_Close(ipcListenSocket);
+ ipcListenSocket = NULL;
+ }
+ } while(!ipcConnSocket);
+ return;
+}
+
+/**
+ * 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_engine_read_message(void *data) {
+ if(!ipcConnSocket && ipcListenSocket) {
+ flib_accept_ipc();
+ }
+
+ if(ipcConnSocket && SDLNet_CheckSockets(ipcConnSocketSet, 0)>0) {
+ int size = SDLNet_TCP_Recv(ipcConnSocket, ipcReadBuffer+ipcReadBufferSize, sizeof(ipcReadBuffer)-ipcReadBufferSize);
+ if(size>0) {
+ ipcReadBufferSize += size;
+ } else {
+ SDLNet_DelSocket(ipcConnSocketSet, (SDLNet_GenericSocket)ipcConnSocket);
+ SDLNet_TCP_Close(ipcConnSocket);
+ ipcConnSocket = NULL;
+ // TODO trigger "IPC disconnect" event, possibly delayed until after the messages are processed
+ }
+ }
+
+ int msgsize = ipcReadBuffer[0];
+ if(ipcReadBufferSize > msgsize) {
+ memcpy(data, ipcReadBuffer+1, msgsize);
+ memmove(ipcReadBuffer, ipcReadBuffer+msgsize+1, ipcReadBufferSize-(msgsize+1));
+ ipcReadBufferSize -= (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;
+ return -1;
+ } else {
+ return -1;
+ }
+}
+
+void flib_engine_write_message(void *data, size_t len) {
+ uint8_t sendbuf[256];
+ if(len>255) {
+ flib_log_e("Attempt to send too much data to the engine in a single message.");
+ return;
+ }
+ sendbuf[0] = len;
+ memcpy(sendbuf+1, data, len);
+ SDLNet_TCP_Send(ipcConnSocket, sendbuf, len+1);
+}
+
+int main(int argc, char *argv[]) {
+ flib_init(0);
+ int port = flib_ipc_listen();
+ printf("%i", port);
+ fflush(stdout);
+ char data[256];
+ while(ipcListenSocket||ipcConnSocket) {
+ int size = flib_engine_read_message(data);
+ if(size>0) {
+ if(data[0]=='?') {
+ flib_engine_write_message("!", 1);
+ }
+ }
+ }
+ return 0;
+}