Working on that server again, Now it does more stuff, er, more address getting. ~Cherish

packages/multicaster/src/multicaster-server.c

@@ -3,13 +3,15 @@
  * found at http://cboard.cprogramming.com/showthread.php?t=67469
  */
 
-#include <stdio.h>      /* for fprintf() */
-#include <sys/types.h>
-#include <sys/socket.h>
 #include <netdb.h>
-#include <stdlib.h>     /* for atoi() and exit() */
+#include <stdio.h>
-#include <unistd.h>
+#include <stdlib.h>
 #include <string.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <unistd.h>
 
 static void DieWithError(const char* errorMessage)
 {
@@ -19,15 +21,15 @@ static void DieWithError(const char* errorMessage)
 
 int main(int argc, char *argv[])
 {
-    int    sock;                   /* Socket */
+	int       sender, listener;	        /* Sockets */
 	char*     multicastIP;                  /* Arg: IP Multicast address */
 	char*     multicastPort;                /* Arg: Server port */
-    char*     sendString;             /* Arg: String to multicast */
+	char*     token;
-    size_t    sendStringLen;          /* Length of string to multicast */
+	size_t    tokenlen;
 	struct    addrinfo * multicastAddr;     /* Multicast address */
 	struct    addrinfo   hints = { 0 };	/* Hints for name lookup */
 
-    if ( argc != 4 )
+	if (argc != 4)
 	{
 		fprintf(stderr, "Usage:  %s <Multicast Address> <Port> <Send String>\n", argv[0]);
 		exit(10);
@@ -35,37 +37,133 @@ int main(int argc, char *argv[])
 
 	multicastIP   = argv[1];             /* First arg:   multicast IP address */
 	multicastPort = argv[2];             /* Second arg:  multicast port */
-    sendString    = argv[3];             /* Third arg:   String to multicast */
+	token	      = argv[3];
-    sendStringLen = strlen(sendString);  /* Find length of sendString */
+	tokenlen      = strlen(token);
 
 	/* Resolve destination address for multicast datagrams */
 	hints.ai_family   = PF_INET6;
 	hints.ai_socktype = SOCK_DGRAM;
 	hints.ai_flags    = AI_NUMERICHOST;
-    if (getaddrinfo(multicastIP, multicastPort, &hints, &multicastAddr) != 0) DieWithError("getaddrinfo() failed");
+
+	if (getaddrinfo(multicastIP, multicastPort, &hints, &multicastAddr) != 0)
+	{
+		DieWithError("getaddrinfo() failed");
+	}
 
 	/* Create socket for sending multicast datagrams */
-    if ((sock = socket(multicastAddr->ai_family, multicastAddr->ai_socktype, 0)) == -1) DieWithError("socket() failed");
+	if ((sender = socket(multicastAddr->ai_family, multicastAddr->ai_socktype, 0)) == -1) 
+	{
+		DieWithError("socket() failed");
+	}
 
+	/* Create socket for recieving multicast datagrams */
+	if ((listener = socket(multicastAddr->ai_family, multicastAddr->ai_socktype, 0)) == -1) 
+	{
+		DieWithError("socket() failed");
+	}
+
+	{
 		int hops = 5;
-    if (setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &hops, sizeof(hops)) != 0) DieWithError("setsockopt(MULTICAST_HOPS) failed");
+		if (setsockopt(sender, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &hops, sizeof(hops)) != 0) 
+		{
+			DieWithError("setsockopt(MULTICAST_HOPS) failed");
+		}
+	}
+
+	/* Join the multicast group.  */
+	if ((multicastAddr->ai_family == PF_INET6)&&(multicastAddr->ai_addrlen == sizeof(struct sockaddr_in6)))
+	{
+		struct sockaddr_in6 *addr = (struct sockaddr_in6 *)(multicastAddr->ai_addr);
+		struct ipv6_mreq multicastRequest;  /* Multicast address join structure */
+
+		/* Specify the multicast group */
+		memcpy(&multicastRequest.ipv6mr_multiaddr, &(addr)->sin6_addr, sizeof(multicastRequest.ipv6mr_multiaddr));
+
+		/* Accept multicast from any interface */
+		multicastRequest.ipv6mr_interface = addr->sin6_scope_id;
+
+		/* Join the multicast address */
+		if (setsockopt(listener, IPPROTO_IPV6, IPV6_JOIN_GROUP, (char*) &multicastRequest, sizeof(multicastRequest)) != 0) 
+		{
+			DieWithError("setsockopt(IPV6_JOIN_GROUP) failed");
+		} 
+	} else {
+		DieWithError("Not IPv6");
+	}
 
 	for (;;) /* Run forever */
 	{
-        int sendLen = sendto(sock, sendString, sendStringLen, 0, multicastAddr->ai_addr, multicastAddr->ai_addrlen);
+		int       n;
-        if (sendLen == sendStringLen )
+		int       max_fd;
+		struct    timeval timeout;
+		fd_set    input;
+		
+		char      recvString[500];      /* Buffer for received string */
+		int       recvStringLen;        /* Length of received string */
+
+		char      sendString[] = "Say Hello\n";
+		size_t    sendStringLen = sizeof(sendString)-1;
+		char      errorString[] = "That is not correct! Try again!\n";
+
+		struct    sockaddr_in6  from;
+		socklen_t fromlen = sizeof(from);
+		
+		FD_ZERO(&input);
+		FD_SET(listener, &input);
+
+		max_fd = listener + 1;
+
+		timeout.tv_sec = 1;
+		timeout.tv_usec = 0;
+
+		n = select(max_fd, &input, NULL, NULL, &timeout);
+
+		/* See if there was an error */
+		if (n < 0)
 		{
-            printf("Sent [%s] (%i bytes) to %s, port %s\n", sendString, sendLen, multicastIP, multicastPort);
+			perror("select failed");
+		} else if (n == 0) {
+			puts("TIMEOUT");
+		} else {
+			if (FD_ISSET(listener, &input))
+			{
+				recvStringLen = recvfrom(listener, recvString, sizeof(recvString) - 1, 0, 
+									(struct sockaddr *)&from, &fromlen);
+				/* Receive a single datagram from the server */
+				if (recvStringLen < 0)
+				{
+					DieWithError("recvfrom() failed");
 				}
-        else
+
+				recvString[recvStringLen] = '\0';
+				if (strcmp(recvString, "hello")==0) 
 				{
+					printf("Correct!!\n");
+					sendto(listener, token, sizeof(sendString), 0, (struct sockaddr *)&from, 														fromlen);
+				} else {
+					sendto(listener, errorString, sizeof(errorString), 0, 								(struct sockaddr *)&from, fromlen);
+				}
+
+				/* Print the received string */
+				printf("Received string [%s]\n", recvString);
+			}
+		}
+
+		int sendLen = sendto(sender, sendString, sendStringLen, 0, multicastAddr->ai_addr, 
+									multicastAddr->ai_addrlen);
+		if (sendLen == sendStringLen)
+		{
+		    printf("Sent [%s] (%i bytes) to %s, port %s\n", sendString, sendLen, 
+								multicastIP, multicastPort);
+		} else {
 		    DieWithError("sendto() sent a different number of bytes than expected");
 		}
-        sleep(1); /* Multicast sendString in datagram to clients every second */
 	}
 
 	/* NOT REACHED */
 	freeaddrinfo(multicastAddr);
-    close(sock);
+	close(sender);
+	close(listener);
+
 	return 0;
 }