class Inspec::Resources::AixPorts

def info
  ports_via_netstat || ports_via_lsof
end

def parse_net_address(net_addr, protocol)
  # local/foreign addresses on AIX use a '.' to separate the addresss
  # from the port
  address, _sep, port = net_addr.rpartition('.')
  if protocol.eql?('tcp6') || protocol.eql?('udp6')
    ip6addr = address
    # AIX uses the wildcard character for ipv6 addresses listening on
    # all interfaces.
    ip6addr = '::' if ip6addr =~ /^\*$/
    # v6 addresses need to end in a double-colon when using
    # shorthand notation. netstat ends with a single colon.
    # IPAddr will fail to properly parse an address unless it
    # uses a double-colon for short-hand notation.
    ip6addr += ':' if ip6addr =~ /\w:$/
    begin
      ip_parser = IPAddr.new(ip6addr)
    rescue IPAddr::InvalidAddressError
      # This IP is not parsable. There appears to be a bug in netstat
      # output that truncates link-local IP addresses:
      # example: udp6 0 0 fe80::42:acff:fe11::123 :::* 0 54550 3335/ntpd
      # actual link address: inet6 fe80::42:acff:fe11:5/64 scope link
      #
      # in this example, the "5" is truncated making the netstat output
      # an invalid IP address.
      return [nil, nil]
    end
    # Check to see if this is a IPv4 address in a tcp6/udp6 line.
    # If so, don't put brackets around the IP or URI won't know how
    # to properly handle it.
    # example: f000000000000000 tcp6       0      0 127.0.0.1.8005          *.*                    LISTEN
    if ip_parser.ipv4?
      ip_addr = URI("addr://#{ip6addr}:#{port}")
      host = ip_addr.host
    else
      ip_addr = URI("addr://[#{ip6addr}]:#{port}")
      host = ip_addr.host[1..ip_addr.host.size-2]
    end
  else
    ip4addr = address
    # In AIX the wildcard character is used to match all interfaces
    ip4addr = '0.0.0.0' if ip4addr =~ /^\*$/
    ip_addr = URI("addr://#{ip4addr}:#{port}")
    host = ip_addr.host
  end
  [host, port.to_i]
end

def parse_netstat_line(line)
  # parse each line
  # 1 - Socket, 2 - Proto, 3 - Receive-Q, 4 - Send-Q, 5 - Local address, 6 - Foreign Address, 7 - State
  parsed = /^(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)?\s+(\S+)/.match(line)
  return {} if parsed.nil?
  # parse ip4 and ip6 addresses
  protocol = parsed[2].downcase
  # detect protocol if not provided
  protocol += '6' if parsed[5].count(':') > 1 && %w{tcp udp}.include?(protocol)
  protocol.chop! if %w{tcp4 upd4}.include?(protocol)
  # extract host and port information
  host, port = parse_net_address(parsed[5], protocol)
  return {} if host.nil?
  # extract PID
  cmd = inspec.command("rmsock #{parsed[1]} tcpcb")
  parsed_pid = /^The socket (\S+) is being held by proccess (\d+) \((\S+)\)/.match(cmd.stdout)
  return {} if parsed_pid.nil?
  process = parsed_pid[3]
  pid = parsed_pid[2]
  pid = pid.to_i if pid =~ /^\d+$/
  {
    'port'     => port,
    'address'  => host,
    'protocol' => protocol,
    'process'  => process,
    'pid'      => pid,
  }
end

def ports_via_lsof
  return nil unless inspec.command('lsof').exist?
  LsofPorts.new(inspec).info
end

def ports_via_netstat
  return nil unless inspec.command('netstat').exist?
  cmd = inspec.command('netstat -Aan | grep LISTEN')
  return nil unless cmd.exit_status.to_i.zero?
  ports = []
  # parse all lines
  cmd.stdout.each_line do |line|
    port_info = parse_netstat_line(line)
    # only push protocols we are interested in
    next unless %w{tcp tcp6 udp udp6}.include?(port_info['protocol'])
    ports.push(port_info)
  end
  ports
end