From: Arran Cudbard-Bell <a.cudbardb@freeradius.org>
Date: Thu, 1 Oct 2020 18:26:04 +0000 (-0500)
Subject: inet: Add function for checking multicast addresses
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7bf527b2a7030cd276972b16ce3eae71ed7dce73;p=thirdparty%2Ffreeradius-server.git

inet: Add function for checking multicast addresses
---

diff --git a/src/lib/util/inet.c b/src/lib/util/inet.c
index 62ecf309cf6..d4a98404145 100644
--- a/src/lib/util/inet.c
+++ b/src/lib/util/inet.c
@@ -82,6 +82,36 @@ int fr_ipaddr_is_inaddr_any(fr_ipaddr_t const *ipaddr)
 	return 0;
 }
 
+/** Determine if an address is a multicast address
+ *
+ * @param ipaddr to check.
+ * @return
+ *	- 0 if it's not.
+ *	- 1 if it is.
+ *	- -1 on error.
+ */
+int fr_ipaddr_is_multicast(fr_ipaddr_t const *ipaddr)
+{
+	if (ipaddr->af == AF_INET) {
+		/*
+		 *	224.0.0.0 (3758096384) - 239.255.255.255 (4026531839)
+		 */
+		if ((ipaddr->addr.v4.s_addr >= 3758096384) && (ipaddr->addr.v4.s_addr <= 4026531839)) return 1;
+#ifdef HAVE_STRUCT_SOCKADDR_IN6
+	} else if (ipaddr->af == AF_INET6) {
+		if (IN6_IS_ADDR_MULTICAST(&(ipaddr->addr.v6))) {
+			return 1;
+		}
+#endif
+
+	} else {
+		fr_strerror_printf("Unknown address family");
+		return -1;
+	}
+
+	return 0;
+}
+
 /** Determine if an address is a prefix
  *
  * @param ipaddr to check.
diff --git a/src/lib/util/inet.h b/src/lib/util/inet.h
index 3a1e6da80a0..7701c578b1d 100644
--- a/src/lib/util/inet.h
+++ b/src/lib/util/inet.h
@@ -113,6 +113,7 @@ extern bool	fr_hostname_lookups; /* do hostname -> IP lookups? */
  *	Utility functions
  */
 int	fr_ipaddr_is_inaddr_any(fr_ipaddr_t const *ipaddr);
+int	fr_ipaddr_is_multicast(fr_ipaddr_t const *ipaddr);
 int	fr_ipaddr_is_prefix(fr_ipaddr_t const *ipaddr);
 
 /*
diff --git a/src/modules/proto_dhcpv6/proto_dhcpv6_udp.c b/src/modules/proto_dhcpv6/proto_dhcpv6_udp.c
index 86fc09d0ca3..777a23ec18d 100644
--- a/src/modules/proto_dhcpv6/proto_dhcpv6_udp.c
+++ b/src/modules/proto_dhcpv6/proto_dhcpv6_udp.c
@@ -285,7 +285,7 @@ static void mod_network_get(void *instance, int *ipproto, bool *dynamic_clients,
 }
 
 
-/** Open a UDP listener for DHCPV4
+/** Open a UDP listener for DHCPv6
  *
  */
 static int mod_open(fr_listen_t *li)
@@ -479,7 +479,7 @@ static int mod_bootstrap(void *instance, CONF_SECTION *cs)
 	/*
 	 *	Remember if we're a multicast socket.
 	 */
-	inst->multicast = (inst->ipaddr.addr.v6.s6_addr[0] == 0xff);
+	inst->multicast = (fr_ipaddr_is_multicast(&inst->ipaddr) == 1);
 
 	/*
 	 *	Set src_ipaddr to ipaddr if not otherwise specified
@@ -507,7 +507,7 @@ static int mod_bootstrap(void *instance, CONF_SECTION *cs)
 
 		} else {
 			/*
-			 *	Multicase addresses MUST specify an interface.
+			 *	Multicast addresses MUST specify an interface.
 			 */
 			if (!inst->interface) goto interface_fail;