Golang - get promiscuous mode status of network interfaces

I use the following Go code to get some info about the network interfaces. Any suggestions on how I would be able to get the status of promiscuous mode for each interface?

type Iface struct {
  Name      string `json:"name"`
  Status    string `json:"status"`
  Multicast bool   `json:"multicast"`
  Broadcast bool   `json:"broadcast"`
}

func (c *InterfacesController) GetInterfaces() {
  interfaces, err := net.Interfaces()

  if err != nil {
    fmt.Println(err)
    return
  }

  var ifaceset []Iface
  var ifc Iface

  for _, i := range interfaces {
    ifc.Name = i.Name
    if strings.Contains(i.Flags.String(), "up") {
        ifc.Status = "UP"
    } else {
        ifc.Status = "DOWN"
    }
    if strings.Contains(i.Flags.String(), "multicast") {
        ifc.Multicast = true
    } else {
        ifc.Multicast = false
    }
    if strings.Contains(i.Flags.String(), "broadcast") {
        ifc.Broadcast = true
    } else {
        ifc.Broadcast = false
    }
    ifaceset = append(ifaceset, ifc)
  }
}

The working environment is Ubuntu, I used the ifconfig command and checked each interface details to see if it contains the word PROMISC. Something like this:

//
// get the interfaces
//
interfaces, err := net.Interfaces()

//
// run the ifconfig command
//
out, err := exec.Command("/bin/sh", "-c", "ifconfig").Output()

var ifc Iface
var ifaceset []Iface

//
// split the output to handle each interface separately
//
var ifaceDetails = strings.Split(string(out), "\n\n")

//
// iterate interfaces
//
for _, i := range interfaces {
    ifc.Name = i.Name
    if strings.Contains(i.Flags.String(), "up") {
    ifc.Status = "UP"
    } else {
        ifc.Status = "DOWN"
    }
    if strings.Contains(i.Flags.String(), "multicast") {
        ifc.Multicast = true
    } else {
        ifc.Multicast = false
    }
    if strings.Contains(i.Flags.String(), "broadcast") {
        ifc.Broadcast = true
    } else {
        ifc.Broadcast = false
    }

    //
    // try to find the word PROMISC to check if it is UP
    //
    for _, ifdetails := range ifaceDetails {
        if strings.Contains(ifdetails, i.Name) {
            if strings.Contains(ifdetails, "PROMISC") {
                ifc.Promisc = true
            } else {
                ifc.Promisc = false
            }

        }
    }
    ifaceset = append(ifaceset, ifc)
}

}