added verify_source setting to socket node-type

include/villas/nodes/socket.h

@@ -32,6 +32,7 @@
 #pragma once
 
 #include <sys/socket.h>
+#include <sys/un.h>
 #include <linux/if_packet.h>
 
 #include "node.h"
@@ -53,27 +54,27 @@ union sockaddr_union {
 	struct sockaddr_in sin;
 	struct sockaddr_in6 sin6;
 	struct sockaddr_ll sll;
+	struct sockaddr_un sun;
 };
 
 struct socket {
-	int sd;				/**> The socket descriptor */
-	int mark;			/**> Socket mark for netem, routing and filtering */
+	int sd;				/**< The socket descriptor */
+	int mark;			/**< Socket mark for netem, routing and filtering */
+	int verify_source;		/**< Verify the source address of incoming packets against socket::remote. */
 
 	enum {
 		SOCKET_ENDIAN_LITTLE,
 		SOCKET_ENDIAN_BIG
-	} endian;			/** Endianness of the data sent/received by the node */
+	} endian;			/**< Endianness of the data sent/received by the node */
 
-	enum socket_layer layer;	/**> The OSI / IP layer which should be used for this socket */
-	enum socket_header header;	/**> Payload header type */
+	enum socket_layer layer;	/**< The OSI / IP layer which should be used for this socket */
+	enum socket_header header;	/**< Payload header type */
 
-	union sockaddr_union local;	/**> Local address of the socket */
-	union sockaddr_union remote;	/**> Remote address of the socket */
+	union sockaddr_union local;	/**< Local address of the socket */
+	union sockaddr_union remote;	/**< Remote address of the socket */
 
-	struct rtnl_qdisc *tc_qdisc;	/**> libnl3: Network emulator queuing discipline */
-	struct rtnl_cls *tc_classifier;	/**> libnl3: Firewall mark classifier */
-
-	struct socket *next;		/* Linked list _per_interface_ */
+	struct rtnl_qdisc *tc_qdisc;	/**< libnl3: Network emulator queuing discipline */
+	struct rtnl_cls *tc_classifier;	/**< libnl3: Firewall mark classifier */
 };
 
 
@@ -127,4 +128,6 @@ char * socket_print_addr(struct sockaddr *saddr);
  */
 int socket_parse_addr(const char *str, struct sockaddr *sa, enum socket_layer layer, int flags);
 
-/** @} */
+int socket_compare_addr(struct sockaddr *x, struct sockaddr *y);
+
+/** @} */

lib/nodes/socket.c

@@ -330,8 +330,11 @@ static int socket_read_villas(struct node *n, struct sample *smps[], unsigned cn
 	char data[MSG_MAX_PACKET_LEN];
 	ssize_t bytes;
 
+	struct sockaddr_storage src;
+	socklen_t srclen = sizeof(src);
+
 	/* Receive message from socket */
-	bytes = recv(s->sd, data, sizeof(data), 0);
+	bytes = recvfrom(s->sd, data, sizeof(data), 0, (struct sockaddr *) &src, &srclen);
 	if (bytes == 0)
 		error("Remote node %s closed the connection", node_name(n));
 	else if (bytes < 0)
@@ -340,11 +343,19 @@ static int socket_read_villas(struct node *n, struct sample *smps[], unsigned cn
 		warn("Received invalid packet for node %s", node_name(n));
 		return 0;
 	}
-	
+
+	if (s->verify_source && socket_compare_addr((struct sockaddr *) &src, (struct sockaddr *) &s->remote) != 0) {
+		char *buf = socket_print_addr((struct sockaddr *) &src);
+
+		warn("Received packet from unauthorized source: %s", buf);
+
+		free(buf);
+	}
+
 	ret = msg_buffer_to_samples(smps, cnt, data, bytes);
 	if (ret < 0)
 		warn("Received invalid packet from node: %s", node_name(n));
-	
+
 	return ret;
 }
 
@@ -490,6 +501,9 @@ int socket_parse(struct node *n, config_setting_t *cfg)
 	if (!config_setting_lookup_string(cfg, "local", &local))
 		cerror(cfg, "Missing local address for node %s", node_name(n));
 
+	if (!config_setting_lookup_bool(cfg, "verify_source", &s->verify_source))
+		s->verify_source = 0;
+
 	ret = socket_parse_addr(local, (struct sockaddr *) &s->local, s->layer, AI_PASSIVE);
 	if (ret) {
 		cerror(cfg, "Failed to resolve local address '%s' of node %s: %s",
@@ -649,6 +663,47 @@ int socket_parse_addr(const char *addr, struct sockaddr *saddr, enum socket_laye
 	return ret;
 }
 
+int socket_compare_addr(struct sockaddr *x, struct sockaddr *y)
+{
+#define CMP(a, b) if (a != b) return a < b ? -1 : 1
+
+	union sockaddr_union *xu = (void *) x, *yu = (void *) y;
+
+	CMP(x->sa_family, y->sa_family);
+
+	switch (x->sa_family) {
+		case AF_UNIX:
+			return strcmp(xu->sun.sun_path, yu->sun.sun_path);
+
+		case AF_INET:
+			CMP(ntohl(xu->sin.sin_addr.s_addr), ntohl(yu->sin.sin_addr.s_addr));
+			CMP(ntohs(xu->sin.sin_port), ntohs(yu->sin.sin_port));
+
+			return 0;
+
+		case AF_INET6:
+			CMP(ntohs(xu->sin6.sin6_port), ntohs(yu->sin6.sin6_port));
+//			CMP(xu->sin6.sin6_flowinfo, yu->sin6.sin6_flowinfo);
+//			CMP(xu->sin6.sin6_scope_id, yu->sin6.sin6_scope_id);
+
+			return memcmp(xu->sin6.sin6_addr.s6_addr, yu->sin6.sin6_addr.s6_addr, sizeof(xu->sin6.sin6_addr.s6_addr));
+
+		case AF_PACKET:
+			CMP(xu->sll.sll_protocol, yu->sll.sll_protocol);
+			CMP(xu->sll.sll_ifindex, yu->sll.sll_ifindex);
+//			CMP(xu->sll.sll_pkttype, yu->sll.sll_pkttype);
+//			CMP(xu->sll.sll_hatype, yu->sll.sll_hatype);
+//			CMP(xu->sll.sll_halen, yu->sll.sll_halen);
+
+			return memcmp(xu->sll.sll_addr, yu->sll.sll_addr, sizeof(xu->sll.sll_addr));
+
+		default:
+			return -1;
+	}
+
+#undef CMP
+}
+
 static struct plugin p = {
 	.name		= "socket",
 	.description	= "BSD network sockets",