1 files changed, 303 insertions, 0 deletions
diff --git a/draft/mcastseed/src/sockets.c b/draft/mcastseed/src/sockets.c
new file mode 100644
index 0000000..6aea016
--- /dev/null
+++ b/draft/mcastseed/src/sockets.c
@@ -0,0 +1,303 @@
+/*
+ * Copyright 2016 by Ludovic Pouzenc <ludovic@pouzenc.fr>
+ *
+ * Greatly inspired from msock.h written by Christian Beier <dontmind@sdf.org>
+ */
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include "sockets.h"
+
+int mcast_recv_socket(char *mcast_ip, char *port, int wanted_so_rcvbuf) {
+
+	int sock;
+	struct addrinfo hints  = { 0 };    /* Hints for name lookup */
+	struct addrinfo *ai_local = NULL;         /* Local address to bind to */
+	struct addrinfo *mcast_ai = NULL;     /* Multicast Address */
+	int yes=1;
+	int status, optval;
+	socklen_t optval_len;
+	int dfltrcvbuf;
+
+	/* Resolve the multicast group address */
+	hints.ai_family = PF_UNSPEC;
+	hints.ai_flags  = AI_NUMERICHOST;
+	if ((status = getaddrinfo(mcast_ip, NULL, &hints, &mcast_ai)) != 0) {
+		fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));
+		goto error;
+	}
+
+	/*
+	 * Get a local address with the same family (IPv4 or IPv6) as our multicast group
+	 * This is for receiving on a certain port.
+	 */
+	hints.ai_family   = mcast_ai->ai_family;
+	hints.ai_socktype = SOCK_DGRAM;
+	hints.ai_flags    = AI_PASSIVE; /* Return an address we can bind to */
+	if ( getaddrinfo(NULL, port, &hints, &ai_local) != 0 ) {
+		fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));
+		goto error;
+	}
+
+	/* Create socket for receiving datagrams */
+	if ( (sock = socket(ai_local->ai_family, ai_local->ai_socktype, 0)) < 0 ) {
+		perror("socket() failed");
+		goto error;
+	}
+
+	/*
+	 * Enable SO_REUSEADDR to allow multiple instances of this
+	 * application to receive copies of the multicast datagrams.
+	 */
+	if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(char*)&yes,sizeof(int)) == -1) {
+		perror("setsockopt");
+		goto error;
+	}
+
+	/* Bind the local address to the multicast port */
+	if ( bind(sock, ai_local->ai_addr, ai_local->ai_addrlen) != 0 ) {
+		perror("bind() failed");
+		goto error;
+	}
+
+	/* get/set socket receive buffer */
+	optval=0;
+	optval_len = sizeof(optval);
+	if(getsockopt(sock, SOL_SOCKET, SO_RCVBUF,(char*)&optval, &optval_len) !=0) {
+		perror("getsockopt");
+		goto error;
+	}
+	dfltrcvbuf = optval;
+	optval = wanted_so_rcvbuf;
+	if(setsockopt(sock,SOL_SOCKET,SO_RCVBUF,(char*)&optval,sizeof(optval)) != 0) {
+		perror("setsockopt");
+		goto error;
+	}
+	if(getsockopt(sock, SOL_SOCKET, SO_RCVBUF,(char*)&optval, &optval_len) != 0) {
+		perror("getsockopt");
+		goto error;
+	}
+	fprintf(stderr, "tried to set socket receive buffer from %d to %d, got %d\n",
+			dfltrcvbuf, wanted_so_rcvbuf, optval);
+
+
+	/* Join the multicast group. We do this seperately depending on whether we
+	 * are using IPv4 or IPv6.
+	 */
+	if ( mcast_ai->ai_family  == PF_INET &&
+			mcast_ai->ai_addrlen == sizeof(struct sockaddr_in) ) /* IPv4 */
+	{
+		struct ip_mreq multicastRequest;  /* Multicast address join structure */
+
+		/* Specify the multicast group */
+		memcpy(&multicastRequest.imr_multiaddr,
+				&((struct sockaddr_in*)(mcast_ai->ai_addr))->sin_addr,
+				sizeof(multicastRequest.imr_multiaddr));
+
+		/* Accept multicast from any interface */
+		multicastRequest.imr_interface.s_addr = htonl(INADDR_ANY);
+
+		/* Join the multicast address */
+		if ( setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char*) &multicastRequest, sizeof(multicastRequest)) != 0 ) {
+			perror("setsockopt() failed");
+			goto error;
+		}
+	}
+	else if ( mcast_ai->ai_family  == PF_INET6 &&
+			mcast_ai->ai_addrlen == sizeof(struct sockaddr_in6) ) /* IPv6 */
+	{
+		struct ipv6_mreq multicastRequest;  /* Multicast address join structure */
+
+		/* Specify the multicast group */
+		memcpy(&multicastRequest.ipv6mr_multiaddr,
+				&((struct sockaddr_in6*)(mcast_ai->ai_addr))->sin6_addr,
+				sizeof(multicastRequest.ipv6mr_multiaddr));
+
+		/* Accept multicast from any interface */
+		multicastRequest.ipv6mr_interface = 0;
+
+		/* Join the multicast address */
+		if ( setsockopt(sock, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, (char*) &multicastRequest, sizeof(multicastRequest)) != 0 ) {
+			perror("setsockopt() failed");
+			goto error;
+		}
+	}
+	else {
+		perror("Neither IPv4 or IPv6");
+		goto error;
+	}
+
+
+	if(ai_local)
+		freeaddrinfo(ai_local);
+	if(mcast_ai)
+		freeaddrinfo(mcast_ai);
+
+	return sock;
+
+error:
+	if(ai_local)
+		freeaddrinfo(ai_local);
+	if(mcast_ai)
+		freeaddrinfo(mcast_ai);
+
+	return -1;
+}
+
+
+int mcast_send_socket(char* mcast_ip, char* port,  int multicastTTL, struct addrinfo **mcast_ai) {
+
+	int sock;
+	struct addrinfo hints = { 0 };    /* Hints for name lookup */
+	int status;
+
+
+	/* Resolve destination address for multicast datagrams */
+	hints.ai_family   = PF_UNSPEC;
+	hints.ai_socktype = SOCK_DGRAM;
+	hints.ai_flags    = AI_NUMERICHOST;
+	if ((status = getaddrinfo(mcast_ip, port, &hints, mcast_ai)) != 0 )
+	{
+		fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));
+		return -1;
+	}
+
+	/* Create socket for sending multicast datagrams */
+	if ( (sock = socket((*mcast_ai)->ai_family, (*mcast_ai)->ai_socktype, 0)) < 0 ) {
+		perror("socket() failed");
+		freeaddrinfo(*mcast_ai);
+		return -1;
+	}
+
+	/* Set TTL of multicast packet */
+	if ( setsockopt(sock,
+				(*mcast_ai)->ai_family == PF_INET6 ? IPPROTO_IPV6        : IPPROTO_IP,
+				(*mcast_ai)->ai_family == PF_INET6 ? IPV6_MULTICAST_HOPS : IP_MULTICAST_TTL,
+				(char*) &multicastTTL, sizeof(multicastTTL)) != 0 ) {
+		perror("setsockopt() failed");
+		freeaddrinfo(*mcast_ai);
+		return -1;
+	}
+
+	/* set the sending interface */
+	if((*mcast_ai)->ai_family == PF_INET) {
+		in_addr_t iface = INADDR_ANY; /* well, yeah, any */
+		if(setsockopt (sock,
+					IPPROTO_IP,
+					IP_MULTICAST_IF,
+					(char*)&iface, sizeof(iface)) != 0) {
+			perror("interface setsockopt() sending interface");
+			freeaddrinfo(*mcast_ai);
+			return -1;
+		}
+
+	}
+	if((*mcast_ai)->ai_family == PF_INET6) {
+		unsigned int ifindex = 0; /* 0 means 'default interface'*/
+		if(setsockopt (sock,
+					IPPROTO_IPV6,
+					IPV6_MULTICAST_IF,
+					(char*)&ifindex, sizeof(ifindex)) != 0) {
+			perror("interface setsockopt() sending interface");
+			freeaddrinfo(*mcast_ai);
+			return -1;
+		}
+
+	}
+
+	return sock;
+}
+
+
+int ucast_server_socket(char* port, int max_pending_conn) {
+
+	int sock;
+	struct addrinfo *serverAddr;
+	struct addrinfo hints = { 0 };    /* Hints for name lookup */
+	int status;
+
+
+	/* Prepare an addrinfo struct for a local socket */
+	hints.ai_family   = PF_INET6;
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags    = AI_PASSIVE;
+	if ((status = getaddrinfo(NULL, port, &hints, &serverAddr)) != 0 )
+	{
+		fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));
+		return -1;
+	}
+	/* Create socket */
+	if ( (sock = socket(serverAddr->ai_family, serverAddr->ai_socktype, serverAddr->ai_protocol)) < 0 ) {
+		perror("socket() failed");
+		freeaddrinfo(serverAddr);
+		return -1;
+	}
+
+	/* Accepts also IPv4 traffic if the socket is INET6 */
+	if(serverAddr->ai_family == PF_INET6) {
+		unsigned int no = 0;
+		if(setsockopt (sock,
+					IPPROTO_IPV6,
+					IPV6_V6ONLY,
+					(char*)&no, sizeof(no)) != 0) {
+			perror("setsockopt() !IPV6_V6ONLY failed");
+			freeaddrinfo(serverAddr);
+			return -1;
+		}
+	}
+
+	/* Bind socket to local address/port */
+	if ( bind(sock, serverAddr->ai_addr, serverAddr->ai_addrlen) < 0 ) {
+		perror("bind() failed");
+		close(sock);
+		freeaddrinfo(serverAddr);
+		return -1;
+	}
+
+	freeaddrinfo(serverAddr);
+
+	/* Start listening incoming connections */
+	if ( listen(sock, max_pending_conn) < 0 ) {
+		perror("listen() failed");
+		close(sock);
+	}
+
+	return sock;
+}
+
+int ucast_client_socket(char* server_ip, char* port) {
+
+	int sock;
+	struct addrinfo *serverAddr;
+	struct addrinfo hints = { 0 };    /* Hints for name lookup */
+	int status;
+
+	/* Resolve destination address */
+	hints.ai_family   = PF_UNSPEC;
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags    = AI_NUMERICHOST;
+	if ((status = getaddrinfo(server_ip, port, &hints, &serverAddr)) != 0 )
+	{
+		fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));
+		return -1;
+	}
+
+	/* Create socket */
+	if ( (sock = socket(serverAddr->ai_family, serverAddr->ai_socktype, 0)) < 0 ) {
+		perror("socket() failed");
+		freeaddrinfo(serverAddr);
+		return -1;
+	}
+
+	/* Connect it to the remote server */
+	if ( connect(sock, serverAddr->ai_addr, serverAddr->ai_addrlen) < 0 ) {
+		perror("connect() failed");
+		close(sock);
+		freeaddrinfo(serverAddr);
+		return -1;
+	}
+
+	freeaddrinfo(serverAddr);
+	return sock;
+}
+