networkctl: first draft

.gitignore

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+bin/
+shard.lock
+src/.*
+src/.*swp
+lib/

shard.yml

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+name: networkctl
+version: 0.1.0
+
+# authors:
+#   - name <email@example.com>
+
+description: |
+    networkctl is a command-line software to manage the network.
+
+# dependencies:
+#   pg:
+#     github: will/crystal-pg
+#     version: "~> 0.5"
+
+targets:
+    networkctl:
+        main: src/main.cr
+
+dependencies:
+    ipaddress:
+        github: sija/ipaddress.cr
+
+# development_dependencies:
+#   webmock:
+#     github: manastech/webmock.cr
+
+license: ISC

src/colors.cr

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+CRED      = "\033[31m"
+CBLUE     = "\033[36m"
+CGREEN    = "\033[32m"
+CRESET    = "\033[00m"
+CORANGE   = "\033[33m"

src/main.cr

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+
+require "option_parser"
+require "ipaddress"
+require "./colors"
+
+simulation = false
+file = nil
+
+OptionParser.parse! do |parser|
+	parser.on "-s", "--simulation", "Export the network configuration." do
+		simulation = true
+	end
+
+	parser.on "-f file", "--file file", "Parse a configuration file." do |optsn|
+		file = optsn
+	end
+
+	# 0: nothing is printed, 1: only events, 2: events and messages
+	parser.on "-v verbosity", "--verbosity verbosity", "Verbosity (0-2). Default: 1" do |optsn|
+		verbosity = optsn.to_i
+	end
+
+	parser.on "-h", "--help", "Show this help" do
+		puts parser
+		exit 0
+	end
+end
+
+class Do < Process
+	class_property simulation = false
+
+	def self.run(cmd : String, params : Array(String) = nil)
+		if @@simulation
+			puts "simulation, do: #{cmd} #{params.join(" ")}"
+			Process::Status.new 0
+		else
+			Process.run cmd, params
+		end
+	end
+end
+
+
+class NetworkCommands
+	class DHCPCommands
+		def self.dhcp(ifname : String)
+			# TODO: verify which dhcp client is installed on the system
+			cmd = "udhcpc"
+			unless Do.run(cmd, [ name ]).success?
+				raise "(#{cmd}) dhcp failed on #{ifname}"
+			end
+		end
+	end
+
+	def self.which(cmd : String)
+		Do.run("which", [ cmd ]).success?
+	end
+
+	class IfconfigCommand
+		def self.interface_exists?(name : String)
+			Do.run("ifconfig", [ name ]).success?
+		end
+		def self.up_or_down(name : String, updown : String)
+			unless Do.run("ifconfig", [ name, updown ]).success?
+				raise "(ifconfig) Cannot set #{updown} link name #{name}"
+			end
+		end
+		def self.up(name : String)
+			self.up_or_down name, "up"
+		end
+		def self.down(name : String)
+			self.up_or_down name, "down"
+		end
+
+		def self.set_ip(name : String, ip : IPAddress)
+			puts "(ip) setup static IP address"
+		end
+	end
+
+	class IPCommand
+		def self.interface_exists?(name : String)
+			Do.run("ip", [ "link", "show", "dev", name ]).success?
+		end
+		def self.up_or_down(name : String, updown : String)
+			unless Do.run("ip", [ "link", "set", updown, "dev", name ]).success?
+				raise "(ip) Cannot set #{updown} link name #{name}"
+			end
+		end
+		def self.up(name : String)
+			self.up_or_down name, "up"
+		end
+		def self.down(name : String)
+			self.up_or_down name, "down"
+		end
+
+		def self.set_ip(name : String, ip : IPAddress)
+			puts "(ip) setup static IP address"
+		end
+	end
+
+
+	def self.choose_command : IfconfigCommand.class | IPCommand.class
+		if self.which("ifconfig")
+			IfconfigCommand
+		elsif self.which("ip")
+			IPCommand
+		else
+			raise "Neither ifconfig or ip commands exists on this system"
+		end
+	end
+
+	def self.interface_exists?(name : String)
+		cmd = self.choose_command
+		cmd.interface_exists?(name)
+	end
+
+	def self.up(ifname : String)
+		cmd = self.choose_command
+		cmd.up(ifname)
+	end
+
+	def self.down(ifname : String)
+		cmd = self.choose_command
+		cmd.up(ifname)
+	end
+
+	def self.set_ip(name : String, ip : IPAddress)
+		puts "(ip) setup static IP address"
+	end
+
+	def self.dhcp(name : String)
+		puts "(ip) setup dynamic IP address"
+		DHCPCommands.dhcp name
+	end
+end
+
+
+#
+# interface configuration
+#
+
+class InterfaceConfiguration
+	class NotSetup
+		def to_s(io : IO)
+			io << "not setup"
+		end
+	end
+
+	class DHCP
+		def to_s(io : IO)
+			io << "dhcp"
+		end
+	end
+
+	property name : String
+	property up : Bool
+	property main_ip_v4 : IPAddress | DHCP | NotSetup
+	property main_ip_v6 : IPAddress | DHCP | NotSetup
+	property aliasses_v4 : Array(IPAddress)
+	property aliasses_v6 : Array(IPAddress)
+
+	def initialize (@name, @up, @main_ip_v4, @main_ip_v6, aliasses)
+		@aliasses_v4 = Array(IPAddress).new
+		@aliasses_v6 = Array(IPAddress).new
+
+		aliasses.each do |ip|
+			if ip.ipv4?
+				@aliasses_v4 << ip
+			else
+				@aliasses_v6 << ip
+			end
+		end
+	end
+
+	def to_s(io : IO)
+		io << to_string
+	end
+
+	def to_string
+		String.build do |str|
+			if NetworkCommands.interface_exists?(@name)
+				str << "#{CGREEN}#{@name}#{CRESET}\n"
+			else
+				str << "#{CRED}#{@name}#{CRESET}\n"
+			end
+
+			str << "\t#{@up? "up" : "down"}\n"
+			str << "\tinet #{@main_ip_v4}\n"
+
+			unless @aliasses_v4.empty?
+				@aliasses_v4.each do |a|
+					str << "\talias #{a}\n"
+				end
+			end
+
+			str << "\tinet6 #{@main_ip_v6}\n"
+
+			unless @aliasses_v6.empty?
+				@aliasses_v6.each do |a|
+					str << "\talias6 #{a}\n"
+				end
+			end
+		end
+	end
+
+	# configure the interface
+	def execute
+		unless NetworkCommands.interface_exists?(@name)
+			raise "The interface #{@name} doesn't exists, yet."
+		end
+
+		puts "OK on va configurer ça"
+		puts "#{self}"
+
+		if @up
+			NetworkCommands.up @name
+		else
+			puts "not marked as 'up' -- ending here"
+			return
+		end
+
+
+		case main_ip_v4 = @main_ip_v4
+		when IPAddress
+			NetworkCommands.set_ip @name, main_ip_v4
+		when DHCP
+			NetworkCommands.dhcp @name
+		when NotSetup
+			puts "no ipv4"
+		else
+			raise "ipv4 configuration: neither static nor dynamic"
+		end
+
+		case main_ip_v6 = @main_ip_v6
+		when IPAddress
+			NetworkCommands.set_ip @name, main_ip_v6
+		# TODO
+		#when Autoconfiguration
+		#	NetworkCommands.autoconfiguration @name
+		#when DHCP
+		#	NetworkCommands.dhcp6 @name
+		when NotSetup
+			puts "no ipv4"
+		else
+			raise "ipv4 configuration: neither static nor dynamic"
+		end
+
+
+		# 	str << "\tinet #{@main_ip_v4}\n"
+
+		# 	str << "\t#{@up? "up" : "down"}\n"
+		# 	str << "\tinet #{@main_ip_v4}\n"
+
+		# 	unless @aliasses_v4.empty?
+		# 		@aliasses_v4.each do |a|
+		# 			str << "\talias #{a}\n"
+		# 		end
+		# 	end
+
+		# 	str << "\tinet6 #{@main_ip_v6}\n"
+
+		# 		@aliasses_v6.each do |a|
+		# 			str << "\talias6 #{a}\n"
+		#		end
+		# alias execution: only when the main ip address is setup
+	end
+end
+
+class NetworkConfigurationParser
+	def self.parse_file(file_name : String) : InterfaceConfiguration
+		content = File.read(file_name)
+		content = content.rchop
+		ifname = /.([a-zA-Z0-9]+)$/.match(file_name).try &.[1]
+		self.parse(ifname.not_nil!, content)
+	end
+
+	def self.parse (ifname : String, data : String) : InterfaceConfiguration
+		up = false
+		main_ip_v4 = InterfaceConfiguration::NotSetup.new
+		main_ip_v6 = InterfaceConfiguration::NotSetup.new
+
+		aliasses = [] of IPAddress
+
+		data.split("\n").each do |line|
+			case line
+			when /^up/
+				up = true
+			when /^inet6? alias .*/
+				ipstr = /^inet6? alias ([a-f0-9:.\/]+)/.match(line).try &.[1]
+				if ipstr.nil?
+					puts "wrong IP address alias, line #{line}"
+					next
+				end
+				aliasses.push IPAddress.parse(ipstr)
+			when /^inet6? dhcp/
+				# IPaddress is DHCP
+				if /^inet /.match(line)
+					main_ip_v4 = InterfaceConfiguration::DHCP.new
+				else
+					main_ip_v6 = InterfaceConfiguration::DHCP.new
+				end
+			when /^inet6? .*/
+				ipstr = /^inet6? ([a-f0-9:.\/]+)/.match(line).try &.[1]
+				if ipstr.nil?
+					puts "wrong IP address, line #{line}"
+					next
+				end
+				if /^inet /.match(line)
+					main_ip_v4 = IPAddress.parse ipstr
+				else
+					main_ip_v6 = IPAddress.parse ipstr
+				end
+			else
+				raise "Cannot parse: #{line}"
+			end
+		end
+
+		InterfaceConfiguration.new(ifname, up, main_ip_v4, main_ip_v6, aliasses)
+	end
+end
+
+Do.simulation = simulation
+
+if file.nil?
+	raise "Cannot choose files yet"
+else
+	# TODO: why having to force "not_nil!" ? Seems like a compiler bug
+	NetworkConfigurationParser.parse_file(file.not_nil!).execute
+end