我可以使用什么系统调用/方法来获取默认的网络网关

Question

Using Go what package, native function, syscall could be used to obtain the default gateway on a *nix system

I would like to avoid creating a wrapper arround netstat, route, ip, etc commands, or read, parse an existing file, the idea is to obtain the values the most os/platform agnostic way posible.

For example this is the output of the route command:

$ route -n get default
   route to: default
destination: default
       mask: default
    gateway: 192.168.1.1
  interface: en1
      flags: <UP,GATEWAY,DONE,STATIC,PRCLONING>
 recvpipe  sendpipe  ssthresh  rtt,msec    rttvar  hopcount      mtu     expire
       0         0         0         0         0         0      1500         0

I would like to do something simliar in order to just print/obtain the gateeway address/interface.

Answer 1

Play with the RoutedInterface() code at https://github.com/golang/net/blob/master/internal/nettest/interface.go

Sample code snip:

rifs := nettest.RoutedInterface("ip", net.FlagUp | net.FlagBroadcast)
if rifs != nil {
    fmt.Println("Routed interface is ",rifs.HardwareAddr.String())
    fmt.Println("Flags are", rifs.Flags.String())
}

Note: You will need to copy the golang code into a local library, since /internal calls are not allowed directly.