module Ethernet::Provisioning

Setup issues such as assigning permissions for Ethernet-level transmission.

Constants

OS

The kernel that the VM is running on (e.g. “darwin”, “linux”)

POINTER_SIZE

Number of bytes taken by a pointer on the Machine.

Public Class Methods

usermode_sockets() click to toggle source

Allow non-root users to create low-level Ethernet sockets.

This is a security risk, because Ethernet sockets can be used to spy on all traffic on the machine’s network. This should not be called on production machines.

Returns true for success, false otherwise. If the call fails, it is most likely because it is not run by root / Administrator.

# File lib/ethernet/provisioning.rb, line 22
def self.usermode_sockets
  case OS
  when /darwin/
    return false unless Kernel.system("sudo chmod o+rw /dev/bpf*")
  when /linux/
    ruby = File.join Config::CONFIG['bindir'],
                     Config::CONFIG['ruby_install_name']
    unless Kernel.system("sudo setcap 'CAP_NET_RAW+eip CAP_NET_ADMIN+eip' #{ruby}")
      return false
    end
    
    # Try to enable Wireshark packet capture for debugging.
    # No big deal if this fails.
    dumpcap = '/usr/bin/dumpcap'
    if File.exist? dumpcap
      Kernel.system("sudo setcap 'CAP_NET_RAW+eip CAP_NET_ADMIN+eip' #{dumpcap}")
    end
  when /win/
    # NOTE: this might not work
    return false unless Kernel.system("sc config npf start= auto")
  else
    raise "Unsupported os #{Ethernet::Provisioning.platform}"
  end
  true
end