🧹

.gitignore

@@ -6,3 +6,4 @@
 /pkg/
 /spec/reports/
 /tmp/
+Gemfile.lock

Gemfile

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
-source "https://rubygems.org"
+source 'https://rubygems.org'
 
-gem "rake", "~> 13.0"
+gem 'rake', '~> 13.0'

Rakefile

@@ -1,4 +1,4 @@
 # frozen_string_literal: true
 
-require "bundler/gem_tasks"
+require 'bundler/gem_tasks'
 task default: %i[]

exe/redhound

@@ -1,7 +1,7 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
 
-$LOAD_PATH << File.join(__dir__, "../lib")
-require "redhound"
+$LOAD_PATH << File.join(__dir__, '../lib')
+require 'redhound'
 
 Redhound::Command.new.run(ARGV.dup)

lib/redhound.rb

@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
-require_relative "redhound/analyzer"
-require_relative "redhound/command"
-require_relative "redhound/header"
-require_relative "redhound/packet_mreq"
-require_relative "redhound/receiver"
-require_relative "redhound/socket_builder"
-require_relative "redhound/version"
+require_relative 'redhound/analyzer'
+require_relative 'redhound/command'
+require_relative 'redhound/header'
+require_relative 'redhound/packet_mreq'
+require_relative 'redhound/receiver'
+require_relative 'redhound/socket_builder'
+require_relative 'redhound/version'

lib/redhound/analyzer.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Redhound
   class Analyzer
     def self.analyze(msg:)
@@ -9,20 +11,19 @@ def initialize(msg:)
     end
 
     def analyze
-      puts "Analyzing..."
+      puts 'Analyzing...'
       ether = Header::Ether.generate(bytes: @msg.bytes[0..13])
-      pp ether
       ether.dump
-      if ether.ipv4?
-        ip = Header::Ipv4.generate(bytes: @msg.bytes[14..33])
-        ip.dump
-        if ip.udp?
-          udp = Header::Udp.generate(bytes: @msg.bytes[34..41])
-          udp.dump
-        elsif ip.icmp?
-          icmp = Header::Icmp.generate(bytes: @msg.bytes[34..41])
-          icmp.dump
-        end
+      return unless ether.ipv4?
+
+      ip = Header::Ipv4.generate(bytes: @msg.bytes[14..33])
+      ip.dump
+      if ip.udp?
+        udp = Header::Udp.generate(bytes: @msg.bytes[34..41])
+        udp.dump
+      elsif ip.icmp?
+        icmp = Header::Icmp.generate(bytes: @msg.bytes[34..41])
+        icmp.dump
       end
     end
   end

lib/redhound/command.rb

@@ -1,5 +1,7 @@
-require "optparse"
-require "socket"
+# frozen_string_literal: true
+
+require 'optparse'
+require 'socket'
 
 module Redhound
   class Command
@@ -10,7 +12,7 @@ def initialize
     def run(argv)
       parse(argv)
       if @options[:ifname].nil?
-        warn "Error: interface is required"
+        warn 'Error: interface is required'
         exit 1
       end
       Receiver.run(ifname: @options[:ifname])
@@ -30,12 +32,21 @@ def parse(argv)
 
           Usage: redhound [options] ...
         BANNER2
-        o.separator ""
-        o.separator "Options:"
-        o.on("-i", "--interface INTERFACE", "name or idx of interface") { |v| @options[:ifname] = v }
-        o.on("-D", "--list-interfaces", "print list of interfaces and exit") { list_interfaces; exit }
-        o.on("-h", "--help", "display this help and exit") { puts o; exit }
-        o.on("-v", "--version", "display version information and exit") { puts "Redhound #{Redhound::VERSION}"; exit }
+        o.separator ''
+        o.separator 'Options:'
+        o.on('-i', '--interface INTERFACE', 'name or idx of interface') { |v| @options[:ifname] = v }
+        o.on('-D', '--list-interfaces', 'print list of interfaces and exit') do
+          list_interfaces
+          exit
+        end
+        o.on('-h', '--help', 'display this help and exit') do
+          puts o
+          exit
+        end
+        o.on('-v', '--version', 'display version information and exit') do
+          puts "Redhound #{Redhound::VERSION}"
+          exit
+        end
         o.on_tail
         o.parse!(argv)
       end

lib/redhound/header.rb

@@ -1,4 +1,6 @@
-require_relative "header/ether"
-require_relative "header/icmp"
-require_relative "header/ipv4"
-require_relative "header/udp"
+# frozen_string_literal: true
+
+require_relative 'header/ether'
+require_relative 'header/icmp'
+require_relative 'header/ipv4'
+require_relative 'header/udp'

lib/redhound/header/ether.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Redhound
   class Header
     class Ether
@@ -11,6 +13,7 @@ def generate(bytes:)
 
       def initialize(bytes:)
         raise ArgumentError, 'bytes must be 14 bytes' unless bytes.size == 14
+
         @bytes = bytes
       end
 
@@ -27,7 +30,7 @@ def ipv4?
       end
 
       def dump
-        puts "ETHERNET HEADER----------------"
+        puts 'ETHERNET HEADER----------------'
         puts self
       end
 
@@ -40,25 +43,25 @@ def to_s
       end
 
       def dhost
-        @dhost.map { |b| b.to_s(16).rjust(2, "0") }.join(":")
+        @dhost.map { |b| b.to_s(16).rjust(2, '0') }.join(':')
       end
 
       def shost
-        @shost.map { |b| b.to_s(16).rjust(2, "0") }.join(":")
+        @shost.map { |b| b.to_s(16).rjust(2, '0') }.join(':')
       end
 
       def type
         if ipv4?
-          "IPv4"
+          'IPv4'
         else
-          "Unknown"
+          'Unknown'
         end
       end
 
       private
 
       def hex_type
-        @hex_type ||= @type.map { |b| b.to_s(16).rjust(2, "0") }.join.to_i(16)
+        @hex_type ||= @type.map { |b| b.to_s(16).rjust(2, '0') }.join.to_i(16)
       end
     end
   end

lib/redhound/header/icmp.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Redhound
   class Header
     class Icmp
@@ -9,6 +11,7 @@ def generate(bytes:)
 
       def initialize(bytes:)
         raise ArgumentError, 'bytes must be bigger than 8 bytes' unless bytes.size >= 8
+
         @bytes = bytes
       end
 
@@ -17,23 +20,23 @@ def generate
         @code = @bytes[1]
         @check = @bytes[2..3]
         # refs: https://www.iana.org/assignments/icmp-parameters/icmp-parameters.xhtml#icmp-parameters-types
-        if @type == 0 || @type == 8
+        if @type.zero? || @type == 8
           @id = @bytes[4..5]
           @seq = @bytes[6..7]
-          @data = @bytes[8..-1]
+          @data = @bytes[8..]
         else
-          @data = @bytes[4..-1]
+          @data = @bytes[4..]
         end
         self
       end
 
       def dump
-        puts "ICMP HEADER----------------"
+        puts 'ICMP HEADER----------------'
         puts self
       end
 
       def to_s
-        if @type == 0 || @type == 8
+        if @type.zero? || @type == 8
           <<~ICMP
             Type: #{@type}
             Code: #{@code}
@@ -55,19 +58,19 @@ def to_s
       private
 
       def check
-        @check.map { |b| b.to_s(16).rjust(2, "0") }.join
+        @check.map { |b| b.to_s(16).rjust(2, '0') }.join
       end
 
       def id
-        @id.map { |b| b.to_s(16).rjust(2, "0") }.join.to_i(16)
+        @id.map { |b| b.to_s(16).rjust(2, '0') }.join.to_i(16)
       end
 
       def seq
-        @seq.map { |b| b.to_s(16).rjust(2, "0") }.join.to_i(16)
+        @seq.map { |b| b.to_s(16).rjust(2, '0') }.join.to_i(16)
       end
 
       def data
-        @data.map { |b| b.chr }.join
+        @data.map(&:chr).join
       end
     end
   end

lib/redhound/header/ipv4.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Redhound
   class Header
     class Ipv4
@@ -13,6 +15,7 @@ def generate(bytes:)
 
       def initialize(bytes:)
         raise ArgumentError, 'bytes must be 20 bytes' unless bytes.size == 20
+
         @bytes = bytes
       end
 
@@ -40,7 +43,7 @@ def udp?
       end
 
       def dump
-        puts "IPv4 HEADER----------------"
+        puts 'IPv4 HEADER----------------'
         puts self
       end
 
@@ -71,38 +74,38 @@ def ihl
       end
 
       def tot_len
-        @tot_len.map { |b| b.to_s(16).rjust(2, "0") }.join.to_i(16)
+        @tot_len.map { |b| b.to_s(16).rjust(2, '0') }.join.to_i(16)
       end
 
       def id
-        @id.map { |b| b.to_s(16).rjust(2, "0") }.join.to_i(16)
+        @id.map { |b| b.to_s(16).rjust(2, '0') }.join.to_i(16)
       end
 
       def frag_off
-        @frag_off.map { |b| b.to_s(16).rjust(2, "0") }.join.to_i(16) & 0x1FFF
+        @frag_off.map { |b| b.to_s(16).rjust(2, '0') }.join.to_i(16) & 0x1FFF
       end
 
       def protocol
         case @protocol
         when ICMP
-          "ICMP"
+          'ICMP'
         when UDP
-          "UDP"
+          'UDP'
         else
-          "Unknown"
+          'Unknown'
         end
       end
 
       def check
-        @check.map { |b| b.to_s(16).rjust(2, "0") }.join.to_i(16)
+        @check.map { |b| b.to_s(16).rjust(2, '0') }.join.to_i(16)
       end
 
       def saddr
-        @saddr.map { |b| b.to_s(16).rjust(2, "0") }.join(".")
+        @saddr.map { |b| b.to_s(16).rjust(2, '0') }.join('.')
       end
 
       def daddr
-        @daddr.map { |b| b.to_s(16).rjust(2, "0") }.join(".")
+        @daddr.map { |b| b.to_s(16).rjust(2, '0') }.join('.')
       end
     end
   end