Reorder new multicast options to conform to BSD. (struct ip_mreq): Ne…

…w type.

inet/netinet/in.h

@@ -166,11 +166,11 @@ struct sockaddr_in
 #define	IP_RECVRETOPTS	6	/* bool; Receive IP options for response.  */
 #define	IP_RECVDSTADDR	7	/* bool; Receive IP dst addr w/datagram.  */
 #define	IP_RETOPTS	8	/* ip_opts; Set/get IP per-packet options.  */
-#define IP_MULTICAST_TTL 9	/* int; TTL for multicast packets */
-#define IP_MULTICAST_LOOP 10	/* bool; Use loopback for multicast */
-#define IP_MULTICAST_IF 11	/* not used; intended to specify interface */
-#define IP_ADD_MEMBERSHIP 12	/* int; join multicast group */
-#define IP_DROP_MEMBERSHIP 13	/* int; leave multicast group */
+#define IP_MULTICAST_IF 9	/* in_addr; set/get IP multicast i/f */
+#define IP_MULTICAST_TTL 10	/* u_char; set/get IP multicast ttl */
+#define IP_MULTICAST_LOOP 11	/* i_char; set/get IP multicast loopback */
+#define IP_ADD_MEMBERSHIP 12	/* ip_mreq; add an IP group membership */
+#define IP_DROP_MEMBERSHIP 13	/* ip_mreq; drop an IP group membership */
 
 /* Structure used to describe IP options for IP_OPTIONS and IP_RETOPTS.
    The `ip_dst' field is used for the first-hop gateway when using a
@@ -181,6 +181,12 @@ struct ip_opts
     char ip_opts[40];		/* Actually variable in size.  */
   };
 
+/* Structure used for IP_ADD_MEMBERSHIP and IP_DROP_MEMBERSHIP. */
+struct ip_mreq
+{
+  struct in_addr imr_multiaddr;	/* IP multicast address of group */
+  struct in_addr imr_interface;	/* local IP address of interface */
+};
 
 /* Functions to convert between host and network byte order.  */