include/ifaddrs.h: add prototypes for get/freeifaddrs

include/ifaddrs.h

@@ -23,6 +23,9 @@ struct ifaddrs {
 #define ifa_broadaddr ifa_ifu.ifu_broadaddr
 #define ifa_dstaddr ifa_ifu.ifu_dstaddr
 
+void freeifaddrs(struct ifaddrs *ifp);
+int getifaddrs(struct ifaddrs **ifap);
+
 #ifdef __cplusplus
 }
 #endif