ftpd.lol

OBTW
	MIT License
	
	Copyright (c) 2019 Donato Rimenti
	
	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is
	furnished to do so, subject to the following conditions:
	
	The above copyright notice and this permission notice shall be included in all
	copies or substantial portions of the Software.
	
	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	SOFTWARE.
TLDR

HAI 1.4
	CAN HAS STDIO?
	CAN HAS SOCKS?
	CAN HAS STRING?
	
	
	BTW global variables
	
	I HAS A command_socket
	I HAS A command_connection
	I HAS A data_ip ITZ ""
	I HAS A data_port
	I HAS A connection_open ITZ FAIL
	
	
	BTW libraries
	
	O HAI IM dec_hex_converter

		HOW IZ I dec_to_hex YR number
			I HAS A remainder
			I HAS A curr_digit
			I HAS A result ITZ ""
			IM IN YR loop NERFIN YR mom WILE DIFFRINT number AN SMALLR OF number AN 0
				remainder R MOD OF number AN 16
				remainder, WTF?
					OMG 10, curr_digit R "A", GTFO
					OMG 11, curr_digit R "B", GTFO
					OMG 12, curr_digit R "C", GTFO
					OMG 13, curr_digit R "D", GTFO
					OMG 14, curr_digit R "E", GTFO
					OMG 15, curr_digit R "F", GTFO
					OMGWTF, curr_digit R remainder, GTFO
				OIC
				result R SMOOSH curr_digit AN result MKAY
				number R QUOSHUNT OF number AN 16
			IM OUTTA YR loop
			FOUND YR result
		IF U SAY SO
		
		HOW IZ I hex_to_dec YR number
			I HAS A num_length ITZ I IZ STRING'Z LEN YR number MKAY
			I HAS A curr_digit_value
			I HAS A curr_char
			I HAS A result ITZ 0
			IM IN YR loop UPPIN YR i WILE DIFFRINT i AN BIGGR OF i AN num_length
				curr_char R I IZ STRING'Z AT YR number AN YR i MKAY
				curr_char, WTF?
					OMG "A", curr_digit_value R 10, GTFO
					OMG "B", curr_digit_value R 11, GTFO
					OMG "C", curr_digit_value R 12, GTFO
					OMG "D", curr_digit_value R 13, GTFO
					OMG "E", curr_digit_value R 14, GTFO
					OMG "F", curr_digit_value R 15, GTFO
					OMGWTF, curr_digit_value R curr_char, GTFO
				OIC
				result R SUM OF PRODUKT OF 16 AN result AN curr_digit_value
			IM OUTTA YR loop
			FOUND YR result
		IF U SAY SO
	
	KTHX
	
	O HAI IM strings_utilz
	
		BTW last index not inclusive
		HOW IZ I substring YR string AN YR start AN YR end
			I HAS A cursor ITZ start
			I HAS A result ITZ ""
			I HAS A curr_char ITZ ""
			
			BTW assuming parameters are correct
			IM IN YR loop UPPIN YR cursor TIL BOTH SAEM cursor AN end
				DIFFRINT cursor AN BIGGR OF cursor AN start
				O RLY?
					YA RLY
					NO WAI,
						curr_char R I IZ STRING'Z AT YR string AN YR cursor MKAY
						result R SMOOSH result AN curr_char MKAY
				OIC
			IM OUTTA YR loop
			FOUND YR result
		IF U SAY SO

		BTW acts as a generator of tokens by returning the token at the given position on the given string using the given separator. There's a known bug: 2 consecutive separator in the string will return FAIL. Works only if string ends with ":)", ":(D)" or separator
		HOW IZ I tokenizer_generator YR string AN YR separator AN YR position
			I HAS A tokens_counter ITZ 0
			I HAS A curr_char ITZ ""
			I HAS A last_token_start_index ITZ 0
			I HAS A last_token_end_index ITZ 0
			I HAS A str_length ITZ I IZ STRING'Z LEN YR string MKAY
			
			BTW position to the current token 
			IM IN YR loop UPPIN YR i TIL BOTH SAEM i AN str_length
				curr_char R I IZ STRING'Z AT YR string AN YR i MKAY
				ANY OF BOTH SAEM curr_char AN ":)" AN BOTH SAEM curr_char AN ":(D)" AN BOTH SAEM curr_char AN separator MKAY
				O RLY?
					YA RLY
						BTW last token is the separator since it's not inclusive
						last_token_end_index R i
						BOTH SAEM tokens_counter AN position
						O RLY?
							YA RLY
								I HAS A result ITZ strings_utilz IZ substring YR string AN YR last_token_start_index AN YR last_token_end_index MKAY
								FOUND YR result
							NO WAI
						OIC
						tokens_counter R SUM OF tokens_counter AN 1
						last_token_start_index R SUM OF last_token_end_index AN 1
					NO WAI
				OIC
			IM OUTTA YR loop
			FOUND YR FAIL
		IF U SAY SO
	
	KTHX
	
	O HAI IM socks_utilz
	
		BTW binds sockets
		command_socket R I IZ SOCKS'Z BIND YR "0.0.0.0" AN YR 21 MKAY
		
		BTW sends a reply on the command socket
		HOW IZ I send_command YR reply
			socks_utilz IZ send YR reply AN YR command_socket AN YR command_connection MKAY
			VISIBLE "REPLY IZ " AN reply
		IF U SAY SO
		
		BTW sends a reply on the data socket
		HOW IZ I send_data YR reply
			I HAS A data_socket ITZ I IZ SOCKS'Z BIND YR "0.0.0.0" AN YR 0 MKAY
			I HAS A data_connection ITZ I IZ SOCKS'Z KONN YR data_socket AN YR data_ip AN YR data_port MKAY
			socks_utilz IZ send YR reply AN YR data_socket AN YR data_connection MKAY
			I IZ SOCKS'Z CLOSE YR data_connection MKAY
			I IZ SOCKS'Z CLOSE YR data_socket MKAY
		IF U SAY SO
	
		BTW reads a reply on the data socket
		HOW IZ I read_data
			I HAS A data_socket ITZ I IZ SOCKS'Z BIND YR "0.0.0.0" AN YR 0 MKAY
			I HAS A data_connection ITZ I IZ SOCKS'Z KONN YR data_socket AN YR data_ip AN YR data_port MKAY
			I HAS A incoming_data ITZ I IZ SOCKS'Z GET YR data_socket AND YR data_connection AN YR 102400 MKAY
			I IZ SOCKS'Z CLOSE YR data_connection MKAY
			I IZ SOCKS'Z CLOSE YR data_socket MKAY
			FOUND YR incoming_data
		IF U SAY SO
		
		BTW send a reply on a socket
		HOW IZ I send YR reply AN YR socket AN YR connection
			I IZ SOCKS'Z PUT YR socket AND YR connection AN YR SMOOSH reply AN ":)" MKAY MKAY
		IF U SAY SO
	
	KTHX

	O HAI IM file_utilz

		BTW reads a file and returns its content
		HOW IZ I read YR file
			I HAS A content ITZ ""
			I HAS A open_file ITZ I IZ STDIO'Z OPEN YR file AN YR "r" MKAY
			I IZ STDIO'Z DIAF YR open_file MKAY
			O RLY?
				YA RLY
					BTW error
					VISIBLE "FIEL " AN file AN " FOUNDNT"
				NO WAI
					BTW read file content and close it
					content R I IZ STDIO'Z LUK YR open_file AN YR 102400 MKAY
					I IZ STDIO'Z CLOSE YR open_file MKAY
			OIC
			FOUND YR content
		IF U SAY SO
		
		BTW writes on a file with the given permissions
		HOW IZ I write_file YR file_name AN YR file_content AN YR permission
			I HAS A file ITZ I IZ STDIO'Z OPEN YR file_name AN YR permission MKAY
			I IZ STDIO'Z SCRIBBEL YR file AN YR file_content MKAY
			I IZ STDIO'Z CLOSE YR file MKAY
		IF U SAY SO

	KTHX
	
	O HAI IM ftp_utilz
	
		BTW decodes an FTP PORT command
		HOW IZ I decode_hex_port YR first_port_number AN YR second_port_number
			I HAS A first_hex ITZ dec_hex_converter IZ dec_to_hex YR first_port_number MKAY
			I HAS A second_hex ITZ dec_hex_converter IZ dec_to_hex YR second_port_number MKAY
			I HAS A hex_port ITZ SMOOSH first_hex AN second_hex MKAY
			dec_hex_converter IZ hex_to_dec YR hex_port MKAY
		IF U SAY SO
		
		BTW stores an FTP file
		HOW IZ I store_file YR incoming_command AN YR permission
			
			BTW gets the file name
			I HAS A file_name ITZ strings_utilz IZ tokenizer_generator YR incoming_command AN YR " " AN YR 1 MKAY
			I HAS A current_token
			IM IN YR loop UPPIN YR i
			
				BTW skips the first tokens
				DIFFRINT i AN BIGGR OF i AN 2
				O RLY?
					YA RLY
					NO WAI,
						BTW adds the next token to the string if present or stops
						current_token R strings_utilz IZ tokenizer_generator YR incoming_command AN YR " " AN YR i MKAY
						
						current_token, O RLY?
							YA RLY,
								file_name R SMOOSH file_name AN " " AN current_token MKAY
							NO WAI,
								GTFO
						OIC
					OIC	
			IM OUTTA YR loop
			
			BTW stores the actual file
			socks_utilz IZ send_command YR "150 CAN HAS FIEL?" MKAY
			I HAS A content ITZ socks_utilz IZ read_data MKAY
			file_utilz IZ write_file YR file_name AN YR content AN YR permission MKAY
			socks_utilz IZ send_command YR "226 AWSOME THX" MKAY
		IF U SAY SO
		
		BTW returns the first message if the first parameter is the same allowed, otherwise returns the second one
		HOW IZ I allow_only YR valid_parameter AN YR incoming_command AN YR message_ok AN YR message_ko
			I HAS A actual_parameter ITZ strings_utilz IZ tokenizer_generator YR incoming_command AN YR " " AN YR 1 MKAY
				BOTH SAEM actual_parameter AN valid_parameter
				O RLY?
					YA RLY,
						socks_utilz IZ send_command YR message_ok MKAY
						GTFO
					NO WAI,
						socks_utilz IZ send_command YR message_ko MKAY
						GTFO
				OIC
		IF U SAY SO
		
		BTW lists files in the main directory
		HOW IZ I list_files
			I HAS A list ITZ file_utilz IZ read YR "whitelist.lul" MKAY
			list, O RLY?
				YA RLY,
					socks_utilz IZ send_command YR "150 PUTTIN MA LIST INTO YR DOOR" MKAY
					socks_utilz IZ send_data YR list MKAY
					socks_utilz IZ send_command YR "226 LIST PUTTED MKAY" MKAY
				NO WAI,
					socks_utilz IZ send_command YR "421 O NOES MA LIST" MKAY
				OIC
		IF U SAY SO
		
	KTHX
	

	BTW command handler
	
	HOW IZ I handle_command YR incoming_command
		strings_utilz IZ tokenizer_generator YR incoming_command AN YR " " AN YR 0 MKAY
		WTF?
			OMG "QUIT"
				connection_open R FAIL
				socks_utilz IZ send_command YR "221 BUH-BYE" MKAY
				GTFO
			OMG "RETR"
				I HAS A file_name ITZ strings_utilz IZ tokenizer_generator YR incoming_command AN YR " " AN YR 1 MKAY
				I HAS A file ITZ file_utilz IZ read YR file_name MKAY
				file, O RLY?
					YA RLY,
						socks_utilz IZ send_command YR "150 CAN HAS FIEL?" MKAY
						socks_utilz IZ send_data YR file MKAY
						socks_utilz IZ send_command YR "226 AWSOME THX" MKAY
					NO WAI,
						socks_utilz IZ send_command YR "421 O NOES" MKAY
				OIC
				GTFO
			OMG "PORT"
				BTW builds the given IP (smoosh to fix stripped last :) )
				I HAS A port_argument ITZ SMOOSH strings_utilz IZ tokenizer_generator YR incoming_command AN YR " " AN YR 1 MKAY AN ":)" MKAY
				
				data_ip R ""
				IM IN YR loop UPPIN YR i TIL BOTH SAEM i AN 4
					data_ip R SMOOSH data_ip AN strings_utilz IZ tokenizer_generator YR port_argument AN YR "," AN YR i MKAY MKAY
					BOTH SAEM i AN 3
					O RLY?
						YA RLY
						NO WAI, data_ip R SMOOSH data_ip AN "." MKAY
					OIC
				IM OUTTA YR loop
				
				BTW builds the given port from hexadecimal
				I HAS A first_port_number ITZ strings_utilz IZ tokenizer_generator YR port_argument AN YR "," AN YR 4 MKAY
				I HAS A second_port_number ITZ strings_utilz IZ tokenizer_generator YR port_argument AN YR "," AN YR 5 MKAY
				
				data_port R ftp_utilz IZ decode_hex_port YR first_port_number AN YR second_port_number MKAY
							
				socks_utilz IZ send_command YR "200 IS TAT A DOOR" MKAY
				GTFO
			OMG "TYPE"
				BTW only ASCII allowed
				ftp_utilz IZ allow_only YR "A" AN YR incoming_command AN YR "200 OH YA SENDIN LETTERZ, COOL" AN YR "504 PLZ SEND LETTERZ" MKAY
				GTFO
			OMG "MODE"
				BTW only STREAM allowed
				ftp_utilz IZ allow_only YR "S" AN YR incoming_command AN YR "200 OIC ITZ LIEK WATER" AN YR "504 TAT A BRICK?" MKAY
				GTFO
			OMG "LIST"
				ftp_utilz IZ list_files MKAY
				GTFO
			OMG "NLST"
				ftp_utilz IZ list_files MKAY
				GTFO
			OMG "STOR"
				ftp_utilz IZ store_file YR incoming_command AN YR "w+" MKAY
				GTFO
			OMG "APPE"
				ftp_utilz IZ store_file YR incoming_command AN YR "a+" MKAY
				GTFO
			OMG "STRU"
				socks_utilz IZ send_command YR "200 U BUILT TIS?" MKAY
				GTFO
			OMG "USER"
				socks_utilz IZ send_command YR "202 OH HAI ANON" MKAY
				GTFO
			OMG "PASS"
				socks_utilz IZ send_command YR "202 ITZ OKAI" MKAY
				GTFO
			OMG "PASV"
				socks_utilz IZ send_command YR "202 NO U" MKAY
				GTFO
			OMG "PWD"
				socks_utilz IZ send_command YR "257 :"/LUL:" GOTCHA YR FOLDR" MKAY
				GTFO
			OMG "NOOP"
				socks_utilz IZ send_command YR "200 U DED?" MKAY
				GTFO
			OMG "ACCT"
				socks_utilz IZ send_command YR "202 ANON ONLY" MKAY
				GTFO
			OMG "CDUP"
				socks_utilz IZ send_command YR "202 NOTHIN UP" MKAY
				GTFO
			OMG "SMNT"
				socks_utilz IZ send_command YR "202 SOUNDZ LIEK MUCH WORK" MKAY
				GTFO
			OMG "REIN"
				socks_utilz IZ send_command YR "200 BIP BOP BUP MKAY" MKAY
				GTFO
			OMG "STOU"
				socks_utilz IZ send_command YR "202 DUPES OK" MKAY
				GTFO
			OMG "FEAT"
				socks_utilz IZ send_command YR "211 I" MKAY
				GTFO
			OMG "SYST"
				socks_utilz IZ send_command YR "215 LOL ITZ I" MKAY
				GTFO
			OMG "CWD"
				socks_utilz IZ send_command YR "502 WERE U GOIN" MKAY
				GTFO
			OMG "REST"
				socks_utilz IZ send_command YR "350 WATCHA WAITIN FOR" MKAY
				GTFO
			OMG "ALLO"
				socks_utilz IZ send_command YR "202 CANT MATH" MKAY
				GTFO
			OMG "RNFR"
				socks_utilz IZ send_command YR "502 U NO LIEK?" MKAY
				GTFO
			OMG "RNTO"
				socks_utilz IZ send_command YR "502 U NO LIEK?" MKAY
				GTFO
			OMG "ABOR"
				socks_utilz IZ send_command YR "226 STAHPPD" MKAY
				GTFO
			OMG "DELE"
				socks_utilz IZ send_command YR "502 CANT DELET" MKAY
				GTFO
			OMG "RMD"
				socks_utilz IZ send_command YR "502 CANT DELET" MKAY
				GTFO
			OMG "MKD"
				socks_utilz IZ send_command YR "502 CANT MAEK" MKAY
				GTFO
			OMG "SITE"
				socks_utilz IZ send_command YR "200 https://www.youtube.com/watch?v=wZZ7oFKsKzY" MKAY
				GTFO
			OMG "STAT"
				socks_utilz IZ send_command YR "211 GOOD THX" MKAY
				GTFO
			OMG "HELP"
				socks_utilz IZ send_command YR "211 PLZ" MKAY
				GTFO
			OMGWTF
				socks_utilz IZ send_command YR "502 WAT" MKAY
				GTFO
		OIC
	IF U SAY SO
	
	
	BTW main loop
	
	IM IN YR connection_loop
	
		BTW listens for a connection
		command_connection R I IZ SOCKS'Z LISTN YR command_socket MKAY
		
		BTW welcome message
		socks_utilz IZ send_command YR "220 TIS WORKIN? U LISTENIN?:)" MKAY
		connection_open R WIN
		
		IM IN YR session_loop NERFIN YR mom TIL NOT connection_open

			BTW reads the next command and reply
			I HAS A incoming_command ITZ I IZ SOCKS'Z GET YR command_socket AN YR command_connection AN YR 1024 MKAY
			
			BTW checks if the incoming command is empty
			BOTH SAEM incoming_command AN ""
			O RLY?
				YA RLY,
					GTFO
				NO WAI,
					VISIBLE "CMD IZ " AN incoming_command
					I IZ handle_command YR incoming_command MKAY
			OIC
	
		IM OUTTA YR session_loop
		
		BTW closes the connection
		I IZ SOCKS'Z CLOSE YR command_connection MKAY
		
	IM OUTTA YR connection_loop
	
KTHXBYE