Simplify handling of multicast addresses.

During the initialization of the eigrpe process, use inet_pton() to
store the EIGRP multicast addresses in two global variables:
* global.mcast_addr_v4 (in_addr);
* global.mcast_addr_v6 (in6_addr).

This way we don't need to create temporary in_addr/in6_addr variables
everytime we need to use these multicast addresses for something.

"I like this" claudio@ ok benno@

eigrp.h

@@ -26,12 +26,9 @@
 #define IPPROTO_EIGRP		88
 #define EIGRP_IP_TTL		2
 
-/* 224.0.0.10 */
-#define AllEIGRPRouters_v4	0xa0000e0 /* network byte order */
-/* ff02::a */
-#define AllEIGRPRouters_v6 \
-	{{{ 0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
-	    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0a }}}
+/* EIGRP multicast group addresses */
+#define AllEIGRPRouters_v4		"224.0.0.10"
+#define AllEIGRPRouters_v6		"ff02::a"
 
 #define EIGRP_INFINITE_METRIC	((uint32_t )(~0))
 

eigrpd.h

@@ -325,6 +325,8 @@ struct eigrpd_global {
 	time_t			 uptime;
 	int			 eigrp_socket_v4;
 	int			 eigrp_socket_v6;
+	struct in_addr		 mcast_addr_v4;
+	struct in6_addr		 mcast_addr_v6;
 	char			*csock;
 };
 

eigrpe.c

@@ -83,6 +83,11 @@ eigrpe(int debug, int verbose, char *sockname)
 	if (control_init(global.csock) == -1)
 		fatalx("control socket setup failed");
 
+	if (inet_pton(AF_INET, AllEIGRPRouters_v4, &global.mcast_addr_v4) != 1)
+		fatal("inet_pton");
+	if (inet_pton(AF_INET6, AllEIGRPRouters_v6, &global.mcast_addr_v6) != 1)
+		fatal("inet_pton");
+
 	/* create the raw ipv4 socket */
 	if ((global.eigrp_socket_v4 = socket(AF_INET,
 	    SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK, IPPROTO_EIGRP)) == -1)

interface.c

@@ -376,8 +376,6 @@ eigrp_if_start(struct eigrp_iface *ei)
 	struct timeval		 now;
 	struct if_addr		*if_addr;
 	union eigrpd_addr	 addr;
-	struct in_addr		 addr4;
-	struct in6_addr		 addr6 = AllEIGRPRouters_v6;
 
 	log_debug("%s: %s as %u family %s", __func__, ei->iface->name,
 	    eigrp->as, af_name(eigrp->af));
@@ -402,12 +400,11 @@ eigrp_if_start(struct eigrp_iface *ei)
 
 	switch (eigrp->af) {
 	case AF_INET:
-		addr4.s_addr = AllEIGRPRouters_v4;
-		if (if_join_ipv4_group(ei->iface, &addr4))
+		if (if_join_ipv4_group(ei->iface, &global.mcast_addr_v4))
 			return;
 		break;
 	case AF_INET6:
-		if (if_join_ipv6_group(ei->iface, &addr6))
+		if (if_join_ipv6_group(ei->iface, &global.mcast_addr_v6))
 			return;
 		break;
 	default:
@@ -422,8 +419,6 @@ void
 eigrp_if_reset(struct eigrp_iface *ei)
 {
 	struct eigrp		*eigrp = ei->eigrp;
-	struct in_addr		 addr4;
-	struct in6_addr		 addr6 = AllEIGRPRouters_v6;
 	struct nbr		*nbr;
 
 	log_debug("%s: %s as %u family %s", __func__, ei->iface->name,
@@ -440,11 +435,10 @@ eigrp_if_reset(struct eigrp_iface *ei)
 	/* try to cleanup */
 	switch (eigrp->af) {
 	case AF_INET:
-		addr4.s_addr = AllEIGRPRouters_v4;
-		if_leave_ipv4_group(ei->iface, &addr4);
+		if_leave_ipv4_group(ei->iface, &global.mcast_addr_v4);
 		break;
 	case AF_INET6:
-		if_leave_ipv6_group(ei->iface, &addr6);
+		if_leave_ipv6_group(ei->iface, &global.mcast_addr_v6);
 		break;
 	default:
 		fatalx("eigrp_if_reset: unknown af");

packet.c

@@ -73,7 +73,7 @@ send_packet_v4(struct iface *iface, struct nbr *nbr, struct ibuf *buf)
 	if (nbr)
 		dst.sin_addr = nbr->addr.v4;
 	else
-		dst.sin_addr.s_addr = AllEIGRPRouters_v4;
+		dst.sin_addr = global.mcast_addr_v4;
 
 	/* setup IP hdr */
 	memset(&ip_hdr, 0, sizeof(ip_hdr));
@@ -121,7 +121,6 @@ static int
 send_packet_v6(struct iface *iface, struct nbr *nbr, struct ibuf *buf)
 {
 	struct sockaddr_in6	 sa6;
-	struct in6_addr		 maddr = AllEIGRPRouters_v6;
 
 	/* setup sockaddr */
 	memset(&sa6, 0, sizeof(sa6));
@@ -131,7 +130,7 @@ send_packet_v6(struct iface *iface, struct nbr *nbr, struct ibuf *buf)
 		sa6.sin6_addr = nbr->addr.v6;
 		addscope(&sa6, iface->ifindex);
 	} else
-		sa6.sin6_addr = maddr;
+		sa6.sin6_addr = global.mcast_addr_v6;
 
 	/* set outgoing interface for multicast traffic */
 	if (IN6_IS_ADDR_MULTICAST(&sa6.sin6_addr))
@@ -532,7 +531,7 @@ recv_packet_v4(int fd, short event, void *bula)
 	 * Packet needs to be sent to AllEIGRPRouters_v4 or to one
 	 * of the interface addresses.
 	 */
-	if (ip_hdr.ip_dst.s_addr != AllEIGRPRouters_v4) {
+	if (ip_hdr.ip_dst.s_addr != global.mcast_addr_v4.s_addr) {
 		struct if_addr	*if_addr;
 		int		 found = 0;
 
@@ -577,7 +576,6 @@ recv_packet_v6(int fd, short event, void *bula)
 	uint16_t		 len;
 	unsigned int		 ifindex = 0;
 	union eigrpd_addr	 src, dest;
-	struct in6_addr		 maddr = AllEIGRPRouters_v6;
 
 	if (event != EV_READ)
 		return;
@@ -627,7 +625,7 @@ recv_packet_v6(int fd, short event, void *bula)
 	 * Packet needs to be sent to AllEIGRPRouters_v6 or to the
 	 * link local address of the interface.
 	 */
-	if (!IN6_ARE_ADDR_EQUAL(&dest.v6, &maddr) &&
+	if (!IN6_ARE_ADDR_EQUAL(&dest.v6, &global.mcast_addr_v6) &&
 	    !IN6_ARE_ADDR_EQUAL(&dest.v6, &iface->linklocal)) {
 		log_debug("%s: packet sent to wrong address %s, interface %s",
 		    __func__, log_in6addr(&dest.v6), iface->name);