1. Add version 4 structure (`statsvar`) in `rstat.x`.
2. Use "netpath" with RPC function in rup and add version 4 RPC call.
### Copmile
1. `cd /usr/src/include/rpcsvc && make all install` // Header file
2. `cd /usr/src/libexec/rpc.rstatd && make all install` // RPC server
3. `cd /usr/src/usr.bin/rup && make all install` // RPC client