#
# Author:: Bryan McLellan (btm@loftninjas.org), Jesse Nelson (spheromak@gmail.com)
# Copyright:: Copyright (c) 2009 Bryan McLellan
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require 'chef/log'
require 'chef/mixin/command'
require 'chef/provider'
require 'ipaddr'

class Chef::Provider::Route < Chef::Provider
    include Chef::Mixin::Command

    attr_accessor :is_running

    MASK = {'0.0.0.0'          => '0',
            '128.0.0.0'        => '1',
            '192.0.0.0'        => '2',
            '224.0.0.0'        => '3',
            '240.0.0.0'        => '4',
            '248.0.0.0'        => '5',
            '252.0.0.0'        => '6',
            '254.0.0.0'        => '7',
            '255.0.0.0'        => '8',
            '255.128.0.0'      => '9',
            '255.192.0.0'      => '10',
            '255.224.0.0'      => '11',
            '255.240.0.0'      => '12',
            '255.248.0.0'      => '13',
            '255.252.0.0'      => '14',
            '255.254.0.0'      => '15',
            '255.255.0.0'      => '16',
            '255.255.128.0'    => '17',
            '255.255.192.0'    => '18',
            '255.255.224.0'    => '19',
            '255.255.240.0'    => '20',
            '255.255.248.0'    => '21',
            '255.255.252.0'    => '22',
            '255.255.254.0'    => '23',
            '255.255.255.0'    => '24',
            '255.255.255.128'  => '25',
            '255.255.255.192'  => '26',
            '255.255.255.224'  => '27',
            '255.255.255.240'  => '28',
            '255.255.255.248'  => '29',
            '255.255.255.252'  => '30',
            '255.255.255.254'  => '31',
            '255.255.255.255'  => '32' }

    def hex2ip(hex_data)
      # Cleanup hex data
      hex_ip = hex_data.to_s.downcase.gsub(/[^0-9a-f]/, '')

      # Check hex data format (IP is a 32bit integer, so should be 8 chars long)
      return nil if hex_ip.length != hex_data.length || hex_ip.length != 8

      # Extract octets from hex data
      octets = hex_ip.scan(/../).reverse.collect { |octet| [octet].pack('H2').unpack("C").first }

      # Validate IP
      ip = octets.join('.')
      begin
        IPAddr.new(ip, Socket::AF_INET).to_s
      rescue ArgumentError
        Chef::Log.debug("Invalid IP address data: hex=#{hex_ip}, ip=#{ip}")
        return nil
      end
    end

    def whyrun_supported?
      true
    end

    def load_current_resource
      self.is_running = false

      # cidr or quad dot mask
      if @new_resource.netmask
        new_ip = IPAddr.new("#{@new_resource.target}/#{@new_resource.netmask}")
      else
        new_ip = IPAddr.new(@new_resource.target)
      end

      # For linux, we use /proc/net/route file to read proc table info
      if node[:os] == "linux"
        route_file = ::File.open("/proc/net/route", "r")

        # Read all routes
        while (line = route_file.gets)
          # Get all the fields for a route
          iface,destination,gateway,flags,refcnt,use,metric,mask,mtu,window,irtt = line.split

          # Convert hex-encoded values to quad-dotted notation (e.g. 0064A8C0 => 192.168.100.0)
          destination = hex2ip(destination)
          gateway = hex2ip(gateway)
          mask = hex2ip(mask)

          # Skip formatting lines (header, etc)
          next unless destination && gateway && mask
          Chef::Log.debug("#{@new_resource} system has route: dest=#{destination} mask=#{mask} gw=#{gateway}")

          # check if what were trying to configure is already there
          # use an ipaddr object with ip/mask this way we can have
          # a new resource be in cidr format (i don't feel like
          # expanding bitmask by hand.
          #
          running_ip = IPAddr.new("#{destination}/#{mask}")
          Chef::Log.debug("#{@new_resource} new ip: #{new_ip.inspect} running ip: #{running_ip.inspect}")
          self.is_running = true if running_ip == new_ip && gateway == @new_resource.gateway
        end

        route_file.close
      end
    end

    def action_add
      # check to see if load_current_resource found the route
      if is_running
        Chef::Log.debug("#{@new_resource} route already active - nothing to do")
      else
        command = generate_command(:add)
        converge_by ("run #{ command } to add route") do
          run_command( :command => command )
          Chef::Log.info("#{@new_resource} added")
        end
      end

      #for now we always write the file (ugly but its what it is)
      generate_config
    end

    def action_delete
      if is_running
        command = generate_command(:delete)
        converge_by ("run #{ command } to delete route ") do
          run_command( :command => command )
          Chef::Log.info("#{@new_resource} removed")
        end
      else
        Chef::Log.debug("#{@new_resource} route does not exist - nothing to do")
      end

      #for now we always write the file (ugly but its what it is)
      generate_config
    end

    def generate_config
      conf = Hash.new
      case node[:platform]
      when "centos", "redhat", "fedora"
        # walk the collection
        run_context.resource_collection.each do |resource|
          if resource.is_a? Chef::Resource::Route
            # default to eth0
            if resource.device
              dev = resource.device
            else
              dev = "eth0"
            end

            conf[dev] = String.new if conf[dev].nil?
            case @action
            when :add
              conf[dev] << config_file_contents(:add, :target => resource.target, :netmask => resource.netmask, :gateway => resource.gateway)
            when :delete
              # need to do this for the case when the last route on an int
              # is removed
              conf[dev] << config_file_contents(:delete)
            end
          end
        end
        conf.each do |k, v|
          network_file_name = "/etc/sysconfig/network-scripts/route-#{k}"
          converge_by ("write route route.#{k}\n#{conf[k]} to #{ network_file_name }") do
            network_file = ::File.new(network_file_name, "w")
            network_file.puts(conf[k])
            Chef::Log.debug("#{@new_resource} writing route.#{k}\n#{conf[k]}")
            network_file.close
          end
        end
      end
    end

    def generate_command(action)
      common_route_items = ''
      common_route_items << "/#{MASK[@new_resource.netmask.to_s]}" if @new_resource.netmask
      common_route_items << " via #{@new_resource.gateway} " if @new_resource.gateway

      case action
      when :add
        command = "ip route replace #{@new_resource.target}"
        command << common_route_items
        command << " dev #{@new_resource.device} " if @new_resource.device
      when :delete
        command = "ip route delete #{@new_resource.target}"
        command << common_route_items
      end

      return command
    end

    def config_file_contents(action, options={})
      content = ''
      case action
      when :add
        content << "#{options[:target]}"
        content << "/#{options[:netmask]}" if options[:netmask]
        content << " via #{options[:gateway]}" if options[:gateway]
        content << "\n"
      end

      return content
    end
end