SIOCSIFNAME in Go instead of C

changeifname.go

package netlink

// #include <net/if.h>
import "C"

import (
	"syscall"
	"unsafe"
)

func getIfSocket() (int, error) {
	fd, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, 0)
	if err == nil {
		return fd, err
	}
	sErr := err

	fd, err = syscall.Socket(syscall.AF_PACKET, syscall.SOCK_DGRAM, 0)
	if err == nil {
		return fd, err
	}

	fd, err = syscall.Socket(syscall.AF_INET6, syscall.SOCK_DGRAM, 0)
	if err == nil {
		return fd, err
	}

	return -1, sErr
}

func NetworkChangeName(oldName, newName string) error {
	fd, err := getIfSocket()
	if err != nil {
		return err
	}
	defer syscall.Close(fd)

	data := [C.IFNAMSIZ * 2]byte{}
	copy(data[:C.IFNAMSIZ-1], oldName)
	copy(data[C.IFNAMSIZ:C.IFNAMSIZ*2-1], newName)

	_, _, errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(fd), syscall.SIOCSIFNAME, uintptr(unsafe.Pointer(&data[0])))
	if errno != 0 {
		return errno
	}

	return nil
}