Direct syscalls using unix.Syscall(unix.SYS_*, ...) are discouraged on macOS and might not be supported in future versions. Instead, use the existing unix.GetsockoptString wrapper to get the interface name. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>