Module: LanScanner

Defined in:
lib/lan_scanner.rb,
lib/lan_scanner/device.rb,
lib/lan_scanner/version.rb

Defined Under Namespace

Classes: Device

Constant Summary collapse

VERSION = 
'0.0.5'.freeze

Class Method Summary collapse

Class Method Details

.my_ip_addresses ⇒ Object 



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# File 'lib/lan_scanner.rb', line 83

def self.my_ip_addresses
  Socket.ip_address_list.select { |ai| ai.ipv4? && !ai.ipv4_loopback? }.map(&:ip_address).uniq
end

.my_networks ⇒ Object 



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# File 'lib/lan_scanner.rb', line 73

def self.my_networks
  my_ip_addresses.map do |a|
    if a.include?('.')
      a.split('.')[0..2].join('.') + '.0/24'
    else
      raise "No support for IPv6 devices"
    end
  end
end

.scan_device_states(addresses, expensive: false) ⇒ Object

get states of given addresses

Parameters:

  • expensive (Boolean) (defaults to: false) —

    make expensive check for devices which were not found by fast check already



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# File 'lib/lan_scanner.rb', line 53

def self.scan_device_states addresses, expensive: false
  addresses = [addresses] unless addresses.is_a? Array
  tmp_file = "#{Dir.tmpdir}/nmap_scan_#{Random.random_number}.xml"
  nmap_scan_option = if expensive
                 '-Pn'
               else
                 '-sn'
               end
  `nmap -sn #{addresses.join(' ')} -oX "#{tmp_file}"`
  online_hosts = _parse_nmap_xml [File.read(tmp_file)]
  offline_addresses = addresses.reject { |a| online_hosts.map(&:remote_address).include?(a) }
  # check offline addresses again with expensive check
  if expensive
    `nmap -sP #{offline_addresses.join(' ')} -oX "#{tmp_file}"`
    online_hosts += _parse_nmap_xml [File.read(tmp_file)]
    offline_addresses = addresses.reject { |a| online_hosts.map(&:remote_address).include?(a) }
  end
  online_hosts + offline_addresses.map { |a| OpenStruct.new(remote_address: a, host_name: nil, state: 'down') }
end

.scan_devices(network: nil) ⇒ Array<LanScanner::Device>

Returns list of devices.

Returns:



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# File 'lib/lan_scanner.rb', line 15

def self.scan_devices(network: nil)
  _ensure_nmap_available
  if network.nil?
    network = my_networks
  end
  network = [network] unless network.is_a? Array
  sn_xml_results = []
  tmp_file = "#{Dir.tmpdir}/nmap_scan_#{Random.random_number}.xml"
  # first we do an -sL scan, which also receives addresses from router/network cache,
  # that are not found by -sn scan when scanning for the complete network, but are found
  # with -sn scan, when scanning for this addresses explicitly
  #
  # so after this scan we scan for this addresses beneath the networks with -sn
  sl_xml_results = []
  network.each do |n|
    ['-sL'].each do |nmap_type|
      `nmap #{nmap_type} #{n} -oX "#{tmp_file}"`
      sl_xml_results.push File.read tmp_file
      File.delete tmp_file
    end
  end
  # here we scan for the received ip addresses from network cache
  sl_ips = _parse_nmap_xml sl_xml_results
  `nmap -sn #{sl_ips.map(&:remote_address).join(' ')} -oX "#{tmp_file}"`
  sn_xml_results.push File.read tmp_file
  # here we ping the networks (fast ping which does not detect all)
  network.each do |n|
    ['-sn'].each do |nmap_type|
      `nmap #{nmap_type} #{n} -oX "#{tmp_file}"`
      sn_xml_results.push File.read tmp_file
      File.delete tmp_file
    end
  end
  _parse_nmap_xml sn_xml_results
end