diff core/client.cpp @ 24:ad5cd8dd99b3 bbb_network

UDP communication in place, pre-alpha

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/client.cpp	Fri May 08 11:12:13 2015 +0100
@@ -0,0 +1,129 @@
+///* UDP client in the internet domain */
+
+#include <ctype.h>
+#include <sys/time.h>
+#include <fcntl.h>
+#include "../include/client.h"
+#include <unistd.h>
+#include <rtdk.h>
+
+#define BUFF_LEN 1024
+#define MAX_VAR_STRING 10
+
+struct sockaddr_in outServer, inServer;
+int outSock, inSock, n, length;
+socklen_t fromlen;
+struct sockaddr_in from;
+char inBuffer[1024];
+char variableString[MAX_VAR_STRING];
+
+int setupSockets(int receivePort, int transmitPort, char const*serverName){
+	//setup transmitter
+	printf("receivePort: %d; transmitPort: %d; serverName: %s\n",receivePort, transmitPort, serverName);
+	outSock= socket(AF_INET, SOCK_DGRAM, 0);
+	outServer.sin_port = htons(transmitPort);
+	if (outSock < 0){
+		error("Opening out socket");
+		return -1;
+	}
+	outServer.sin_family = AF_INET;
+	inet_pton(AF_INET,serverName,&outServer.sin_addr);
+
+	//setup receiver
+	inSock=socket(AF_INET, SOCK_DGRAM, 0);
+	if (inSock < 0){
+		return -1;
+		error("Opening in socket");
+	}
+	length = sizeof(inServer);
+	inServer.sin_family=AF_INET;
+	inServer.sin_addr.s_addr=INADDR_ANY;
+	inServer.sin_port=htons(receivePort);
+	if (bind(inSock,(struct sockaddr *)&inServer,length)<0)
+	   error("binding");
+	fromlen = sizeof(struct sockaddr_in);
+	return 0;
+}
+int sendMessage(networkData message)
+{
+   unsigned int length;
+   char buffer[BUFF_LEN];
+   length=sizeof(struct sockaddr_in);
+   int k=0;
+   k=sprintf(buffer+k, "%8d;",*message.counter);
+   for(int j=0; j<message.numVariables; j++){
+	   k+=sprintf(buffer+k, "%.3f;",*message.variables[j]);
+	   if(k>BUFF_LEN - 20) //safety margin
+		   continue;
+   }
+   sprintf(buffer+k,"\n");
+  // printf(buffer);
+   n=sendto(outSock,buffer,
+            strlen(buffer),0,(const struct sockaddr *)&outServer,length);
+   if (n < 0) error("Sendto");
+   return 0;
+}
+/*
+int receiveMessage()
+{
+   int n = recvfrom(inSock,inBuffer,1024,0,(struct sockaddr *)&from,&fromlen);
+   if (n < 0) error("recvfrom");
+   printf("Received a datagram: ");
+   printf(inBuffer);
+ }
+*/
+
+
+int receiveMessage(networkData message){
+	struct timeval stTimeOut;
+	fd_set stReadFDS;
+	FD_ZERO(&stReadFDS);
+	// Timeout of one second
+	stTimeOut.tv_sec = 0;
+	stTimeOut.tv_usec = 1000;
+	FD_SET(inSock, &stReadFDS);
+
+	int t = select(inSock+1, &stReadFDS, NULL, NULL, &stTimeOut);
+	if (t == -1) {
+		rt_fprintf(stderr, "Call to select() failed");
+		return -1;
+	}
+	else if (t != 0) {
+		if (FD_ISSET(inSock, &stReadFDS)) {
+//			printf("There is data pending to be read..."); // Read data with recv()
+			int n = recvfrom(inSock,inBuffer,1024,0,(struct sockaddr *)&from,&fromlen);
+			if (n < 0){
+				rt_fprintf(stderr,"Error while receiving");
+				return -1;
+			}
+			printf("Received a datagram: ");
+			printf(inBuffer);
+			//the worst parser ever
+			int previousN=0;
+			int currentVariable=0;
+			for(int n=0; inBuffer[n]!=0 && currentVariable<message.numVariables && n-previousN<MAX_VAR_STRING;n++){ //scan the string
+				if(inBuffer[n]==';'||n==0){ // if you find a separator or you are at the end of the string, parse the variable
+					int j=0;
+					inBuffer[n]=0;	 //set the semicolon to 0 ...
+					while( (variableString[j++]=inBuffer[previousN++]) ); // ... so that this will stop when it gets there
+					rt_printf("variable %d: %s\n", currentVariable, variableString);
+					*(message.variables[currentVariable])=atof(variableString);
+					n++; //increment to step after the semicolon
+					previousN=n;
+					currentVariable++;
+				}
+			}
+		}
+	}
+	return 0;
+}
+
+void closeSockets(){
+   close(outSock);
+   close(inSock);
+}
+void error(const char *msg)
+{
+    perror(msg);
+    exit(0);
+}