Since size of struct in_aliasreq has just been changed in r228571,

and thus ifconfig(8) needs recompile, it is a good chance to make
parameter checks on SIOCAIFADDR arguments more strict.

sbin/ifconfig/af_inet.c

@@ -126,6 +126,7 @@ in_getaddr(const char *s, int which)
 				*p = '/';
 				errx(1, "%s: bad value (width %s)", s, errstr);
 			}
+			min->sin_family = AF_INET;
 			min->sin_len = sizeof(*min);
 			min->sin_addr.s_addr = htonl(~((1LL << (32 - masklen)) - 1) & 
 				              0xffffffff);

sys/netinet/in.c

@@ -253,16 +253,10 @@ in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
 		    sizeof(struct sockaddr_in) ||
 		    ifra->ifra_broadaddr.sin_family != AF_INET))
 			return (EINVAL);
-#if 0
-		/*
-		 * ifconfig(8) historically doesn't set af_family for mask
-		 * for unknown reason.
-		 */
 		if (ifra->ifra_mask.sin_len != 0 &&
 		    (ifra->ifra_mask.sin_len != sizeof(struct sockaddr_in) ||
 		    ifra->ifra_mask.sin_family != AF_INET))
 			return (EINVAL);
-#endif
 		break;
 	case SIOCSIFADDR:
 	case SIOCSIFBRDADDR: