Add isc_netaddr_ismulticast() and isc_sockaddr_ismulticast()

lib/isc/include/isc/ipv6.h

@@ -123,4 +123,10 @@ struct sockaddr_in6 {
          ((a)->s6_addr32[1] == 0) &&          \
          ((a)->s6_addr32[2] == htonl(0x0000ffff)))
 
+/*
+ * Multicast
+ */
+#define IN6_IS_ADDR_MULTICAST(a)	\
+	((a)->s6_addr8[0] == 0xffU)
+
 #endif /* ISC_IPV6_H */

lib/isc/include/isc/netaddr.h

@@ -92,6 +92,12 @@ isc_netaddr_fromin(isc_netaddr_t *netaddr, const struct in_addr *ina);
 void
 isc_netaddr_fromin6(isc_netaddr_t *netaddr, const struct in6_addr *ina6);
 
+isc_boolean_t
+isc_netaddr_ismulticast(isc_netaddr_t *na);
+/*
+ * Returns ISC_TRUE if the address is a multicast address
+ */
+
 ISC_LANG_ENDDECLS
 
 #endif /* ISC_NETADDR_H */

lib/isc/include/isc/sockaddr.h

@@ -119,6 +119,12 @@ isc_sockaddr_format(isc_sockaddr_t *sa, char *array, unsigned int size);
  * The resulting string is guaranteed to be null-terminated.
  */
 
+isc_boolean_t
+isc_sockaddr_ismulticast(isc_sockaddr_t *sa);
+/*
+ * Returns ISC_TRUE if the address is a multicast address
+ */
+
 #define ISC_SOCKADDR_FORMATSIZE \
 	sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:XXX.XXX.XXX.XXX#YYYYY")
 /*

lib/isc/netaddr.c

@@ -212,8 +212,7 @@ isc_netaddr_fromin6(isc_netaddr_t *netaddr, const struct in6_addr *ina6) {
 }
 
 void
-isc_netaddr_fromsockaddr(isc_netaddr_t *t, const isc_sockaddr_t *s)
-{
+isc_netaddr_fromsockaddr(isc_netaddr_t *t, const isc_sockaddr_t *s) {
 	int family = s->type.sa.sa_family;
 	t->family = family;
 	switch (family) {
@@ -228,3 +227,16 @@ isc_netaddr_fromsockaddr(isc_netaddr_t *t, const isc_sockaddr_t *s)
         }
 }
 
+isc_boolean_t
+isc_netaddr_ismulticast(isc_netaddr_t *na) {
+	switch (na->family) {
+	case AF_INET:
+		return (ISC_TF(ISC_IPADDR_ISMULTICAST(na->type.in.s_addr)));
+		break;
+	case AF_INET6:
+		return (ISC_TF(IN6_IS_ADDR_MULTICAST(&na->type.in6)));
+		break;
+	default:
+		return (ISC_FALSE);  /* XXXMLG ? */
+	}
+}

lib/isc/sockaddr.c

@@ -378,3 +378,11 @@ isc_sockaddr_getport(isc_sockaddr_t *sockaddr) {
 
 	return (port);
 }
+
+isc_boolean_t
+isc_sockaddr_ismulticast(isc_sockaddr_t *sockaddr) {
+	isc_netaddr_t netaddr;
+
+	isc_netaddr_fromsockaddr(&netaddr, sockaddr);
+	return (isc_netaddr_ismulticast(&netaddr));
+}

lib/isc/unix/include/isc/net.h

@@ -45,6 +45,9 @@
  * It ensures that INADDR_ANY, IN6ADDR_ANY_INIT, in6addr_any, and
  * in6addr_loopback are available.
  *
+ * It ensures that IN_MULTICAST() is available to check for multicast
+ * addresses.
+ *
  * MP:
  *	No impact.
  *
@@ -125,6 +128,16 @@ typedef isc_uint16_t in_port_t;
 #define ISC_PLATFORM_RECVOVERFLOW
 #endif
 
+#define ISC__IPADDR(x)	((isc_uint32_t)htonl((isc_uint32_t)(x)))
+
+#ifdef IN_MULTICAST
+#define ISC_IPADDR_ISMULTICAST(i)	IN_MULTICAST(i)
+#else
+#define ISC_IPADDR_ISMULTICAST(i) \
+		(((isc_uint32_t)(i) & ISC__IPADDR(0xf0000000)) \
+		 == ISC__IPADDR(0xe0000000))
+#endif
+
 /***
  *** Functions.
  ***/