From d80da258e377f02f0dcd703b89a1044cc58e949f Mon Sep 17 00:00:00 2001
From: Michael Graff <mgraff@isc.org>
Date: Thu, 15 Jun 2000 18:23:54 +0000
Subject: [PATCH] Add isc_netaddr_ismulticast() and isc_sockaddr_ismulticast()

---
 lib/isc/include/isc/ipv6.h     |  6 ++++++
 lib/isc/include/isc/netaddr.h  |  6 ++++++
 lib/isc/include/isc/sockaddr.h |  6 ++++++
 lib/isc/netaddr.c              | 16 ++++++++++++++--
 lib/isc/sockaddr.c             |  8 ++++++++
 lib/isc/unix/include/isc/net.h | 13 +++++++++++++
 6 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/lib/isc/include/isc/ipv6.h b/lib/isc/include/isc/ipv6.h
index 3b3e5fe588..e2f73ca5d1 100644
--- a/lib/isc/include/isc/ipv6.h
+++ b/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 */
diff --git a/lib/isc/include/isc/netaddr.h b/lib/isc/include/isc/netaddr.h
index f6e569e34b..f01b56d5e7 100644
--- a/lib/isc/include/isc/netaddr.h
+++ b/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 */
diff --git a/lib/isc/include/isc/sockaddr.h b/lib/isc/include/isc/sockaddr.h
index 781259ae3b..20608dbfbe 100644
--- a/lib/isc/include/isc/sockaddr.h
+++ b/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")
 /*
diff --git a/lib/isc/netaddr.c b/lib/isc/netaddr.c
index 0029f72608..49a37653f9 100644
--- a/lib/isc/netaddr.c
+++ b/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 ? */
+	}
+}
diff --git a/lib/isc/sockaddr.c b/lib/isc/sockaddr.c
index 31bd4399d8..05b5903519 100644
--- a/lib/isc/sockaddr.c
+++ b/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));
+}
diff --git a/lib/isc/unix/include/isc/net.h b/lib/isc/unix/include/isc/net.h
index 710e3ea132..8d4c25f9f1 100644
--- a/lib/isc/unix/include/isc/net.h
+++ b/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.
  ***/