Log, source, client communication, structure

README.md

@@ -44,7 +44,7 @@ Le protocole utilisé entre clients et serveur est très simple.
 	VERSION/LANG/LENGTH\nDATA
 
 **VERSION** étant la version du protocole utilisée pour le paquet, **LANG** le langage utilisé pour coder les données, **LENGTH** la taille des données, **DATA** les données.  
-Pour le moment, seul le JSON est utilisé.
+Les champs de l'entête sont séparés par un slash, l'entête est suivie d'une nouvelle ligne puis des données. Pour le moment, seul le JSON est utilisé.
 
 Les données JSON comprennent un champ "error".
 
@@ -53,20 +53,27 @@ Les données JSON comprennent un champ "error".
 	17: Communication error: unsupported protocol version
 	18: Communication error: unknown language
 	19: Communication error: decoding JSON
-	48: Game management error: that game name is already used
-	49: Game management error: miss new game name
-	50: Game management error: miss game name
-	51: Game management error: there is no game with this name
-	52: Game management error: miss admin password
-	53: Game management error: wrong admin password
-	54: Game management error: that player does not exist
-	55: Game management error: wrong player password
-	56: Game management error: miss player password
+	48: Game error: that game name is already used
+	49: Game error: miss new game name
+	50: Game error: miss game name
+	51: Game error: there is no game with this name
+	52: Game error: miss admin password
+	53: Game error: wrong admin password
+	54: Game error: that player does not exist
+	55: Game error: wrong player password
+	56: Game error: miss player password
+	57: Game error: miss exchange data
+	128: Server error: source not available
 
 Exemple de paquet valide :
 	geco42/json/109
 	{"error": 0, "server_info": {"version": "1.2.3", "protocol_versions": ["geco40","geco41","geco42","geco43"]}}
 
+#### Échanges
+
+**(Non implémenté)** Un échange de valeurs et/ou d'argent entre joueurs nécessite l'accord de tous les joueurs devant fournir de la richesse.  
+Pour proposer un échange, les joueurs négocient entre eux (en P2P) les conditions. Quand ils sont en accord, ils envoient chacun au serveur les données de l'échange, contenant la liste des transactions. Le serveur valide les transactions dès qu'il a reçu la confirmation de tous les joueurs impliqués (devant donner quelque chose).
+
 ## Sources
 
 http://www.trm.creationmonetaire.info/TheorieRelativedelaMonnaie.pdf  

server.py

@@ -17,33 +17,9 @@
 	along with Pygeconomicus-server.  If not, see <https://www.gnu.org/licenses/>.
 """
 
-from sys import argv
-from time import time
-import configparser, socket, json, os
-from random import randint, choice
 import money_free, money_debt
 from utils import *
 
-# Default game constants
-CONSTS = {
-	"N_VALUES": 4, # number of values types
-	"N_WVALUES": 1, # number of waiting values types
-	"TURN_DURATION": 300, # in seconds
-	"N_TURNS": 10, # number of turns in a game
-	"TURN_YEARS": 8, # number of years by turn
-	"LIFESPAN": 10, # max age
-	"N_DIGITS": 0, # number of decimals
-	"START_VALUES": 4 # number of random values for beginning
-}
-
-# Default server constants
-PATH_CONF = "server.ini" # config file relative path
-RECBUF = 1024 # reception buffer length
-PROTOCOL_VERSIONS = ["geco0"]# supported protocol versions
-VERSION = "0.0.0"
-HOST = socket.gethostname() # server host name
-PORT = 8651 # server port
-
 games = []
 games_index = {}
 
@@ -66,7 +42,7 @@ class Game():
 	def __init__(self, name, public, admin_name, admin_address, admin_psw, consts):
 		# Consts
 		self.name = name
-		self.creation_time = int(time())
+		self.creation_time = int(time.time())
 		self.public = public
 		self.admin_name = admin_name
 		self.admin_address = admin_address
@@ -81,6 +57,7 @@ class Game():
 		self.turn = None # current turn number
 		self.endturn = None # end turn timestamp
 		self.values = [None] * self.C["N_VALUES"] # values order (the last is the waiting value)
+		self.exchanges = [] # pending exchanges
 	
 	# Add one player
 	# address is ("address", port)
@@ -110,7 +87,7 @@ class Game():
 		# Start with random values
 		player.values = [0] * self.C["N_VALUES"]
 		for i in range(self.C["START_VALUES"]):
-			player.values[randint(0, self.C["N_VALUES"]-self.C["N_WVALUES"])-1] += 1
+			player.values[random.randint(0, self.C["N_VALUES"]-self.C["N_WVALUES"])-1] += 1
 		
 		# Init in MoneySystem
 		player.wallet = 0
@@ -134,7 +111,7 @@ class Game():
 			age = (age+1) % self.C["LIFESPAN"]
 		
 		for player in self.players:
-			age_p = choice(ages)
+			age_p = random.choice(ages)
 			player.age = age_p
 			ages.remove(age_p)
 			self.initPlayer(player, False)
@@ -157,33 +134,11 @@ class Game():
 				player.age = 0
 				self.initPlayer(player, True)
 
-# Read config
-def readConfig():
-	conf = configparser.ConfigParser()
-	conf.read(PATH_CONF)
-	if "Server" in conf:
-		if "Host" in conf["Server"]:
-			host = conf["Server"]["Host"]
-		if "Port" in conf["Server"]:
-			port = int(conf["Server"]["Port"])
-	if "Game" in conf:
-		for key, value in conf["Game"].items():
-			CONSTS[key] = value
-
-def sendErrorToClient(client, errcode, resp_lng="json"):
-	if resp_lng == "json":
-		resp_raw = json.dumps({"error":errcode}).encode()
-	client.sendall(resp_raw)
-	client.close()
-
-"""
-	Partie serveur en dessous, pas encore complètement fonctionnelle.
-"""
 if __name__ == "__main__":
 	# Config
 	
 	readConfig()
-	if "--help" in argv:
+	if "--help" in sys.argv:
 		print("pygeconomicus-server "+VERSION+"\n\
 Copyright 2018 Pascal Engélibert (GNU AGPL v3+)\n\
 \n\
@@ -195,27 +150,14 @@ Options:\n\
 ")
 		exit()
 	
-	if "--source" in argv:
-		import tarfile
-		def tarReset(tarinfo):
-			tarinfo.uid = tarinfo.gid = 0
-			tarinfo.uname = tarinfo.gname = "root"
-			return tarinfo
-		tar = tarfile.open("sourcecode.tar.gz", "w:gz")
-		tar.add("server.py", filter=tarReset)
-		tar.add("money_free.py", filter=tarReset)
-		tar.add("money_debt.py", filter=tarReset)
-		tar.add("utils.py", filter=tarReset)
-		tar.add("README.md", filter=tarReset)
-		tar.add("LICENSE", filter=tarReset)
-		tar.close()
-		print("Archive successfully created!")
+	if "--source" in sys.argv:
+		tarSource()
 		exit()
 	
-	HOST = getargv(argv, "-h", HOST)
+	HOST = getargv(sys.argv, "-h", HOST)
 	
 	try:
-		PORT = int(getargv(argv, "-p", PORT))
+		PORT = int(getargv(sys.argv, "-p", PORT))
 	except ValueError:
 		print("Error: port must be an integer")
 		exit(1)
@@ -227,7 +169,7 @@ Options:\n\
 	sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 	sock.bind(server_address)
 	sock.listen(1)
-	print("Server started at "+str(server_address))
+	logPrint("Server started at "+str(server_address), LOG_INFO)
 	while loop:
 		client, addr = sock.accept()
 		client.settimeout(5)
@@ -289,10 +231,29 @@ Options:\n\
 					sendErrorToClient(client, ERROR_COM_JSON, resp_lng)# Communication error: decoding JSON
 					continue
 				
-				if "query" in p_data:
+				if "source" in p_data:
+					logPrint("Received source code request", LOG_TRACE)
+					p_resp = True
+					source_time = os.path.getmtime(SOURCE_ARCHIVE)
+					for source_file in SOURCE_FILES:
+						if os.path.getmtime(source_file) > source_time:
+							tarSource()
+							break
+					if os.path.isfile(SOURCE_ARCHIVE):
+						resp_lng = "raw"
+						f = open(SOURCE_ARCHIVE, "rb")
+						resp_raw = f.read()
+						f.close()
+					else:
+						logPrint("Source archived but file does not exist: '"+SOURCE_ARCHIVE+"'", LOG_ERROR)
+						sendErrorToClient(client, ERROR_SRV_NOSOURCE, resp_lng)# Server error: source not available
+						continue
+				
+				elif "query" in p_data:
 					p_resp = True
 					
 					if "games" in p_data["query"]:
+						logPrint("Received games list query", LOG_TRACE)
 						resp["games"] = []
 						for game in games:
 							if game.public:
@@ -302,13 +263,14 @@ Options:\n\
 								resp["games"].append(gp)
 					
 					if "game_info" in p_data["query"]:
+						logPrint("Received game list query", LOG_TRACE)
 						if not "game_name" in p_data:
-							sendErrorToClient(client, ERROR_MGAME_MISSGAMENAME, resp_lng)# Game management error: miss game name
+							sendErrorToClient(client, ERROR_GAME_MISSGAMENAME, resp_lng)# Game error: miss game name
 							continue
 						g_name = p_data["game_name"]
 					
 						if not g_name in games_index:
-							sendErrorToClient(client, ERROR_MGAME_NONAMED, resp_lng)# Game management error: there is no game with this name
+							sendErrorToClient(client, ERROR_GAME_NONAMED, resp_lng)# Game error: there is no game with this name
 							continue
 						game = games_index[g_name]
 						
@@ -319,9 +281,11 @@ Options:\n\
 							resp["game_info"]["players"].append({"player_name":player.name, "player_uid":player.uid, "player_address":player.address[0], "player_port":player.address[1]})
 					
 					if "server_info" in p_data["query"]:
+						logPrint("Received server info query", LOG_TRACE)
 						resp["server_info"] = {"version":VERSION, "protocol_versions":PROTOCOL_VERSIONS}
 				
 				if "new_game" in p_data:
+					logPrint("Received new game command", LOG_TRACE)
 					p_resp = True
 					g = p_data["new_game"]
 					
@@ -336,7 +300,7 @@ Options:\n\
 						g_admin_name = g["admin_name"]
 					
 					if not "admin_psw" in g:
-						sendErrorToClient(client, ERROR_MGAME_MISSADMINPSW, resp_lng)# Game management error: miss admin password
+						sendErrorToClient(client, ERROR_GAME_MISSADMINPSW, resp_lng)# Game error: miss admin password
 						continue
 					g_admin_psw = g["admin_psw"]
 					
@@ -349,10 +313,10 @@ Options:\n\
 						g_public = g["public"]
 					
 					if not "name" in g:
-						sendErrorToClient(client, ERROR_MGAME_MISSNEWGAMENAME, resp_lng)# Game management error: miss new game name
+						sendErrorToClient(client, ERROR_GAME_MISSNEWGAMENAME, resp_lng)# Game error: miss new game name
 						continue
 					if g["name"] in games_index:
-						sendErrorToClient(client, ERROR_MGAME_USEDGAMENAME, resp_lng)# Game management error: that game name is already used
+						sendErrorToClient(client, ERROR_GAME_USEDGAMENAME, resp_lng)# Game error: that game name is already used
 						continue
 					game = Game(g["name"], g_public, g_admin_name, g_admin_address, g_admin_psw, g_consts)
 					games.append(game)
@@ -360,14 +324,15 @@ Options:\n\
 					resp["new_game_info"] = {"name":game.name, "public":game.public, "creation_time":game.creation_time, "admin_name":game.admin_name, "admin_address":game.admin_address, "consts":game.C}
 				
 				if "edit_game" in p_data:
+					logPrint("Received edit game command", LOG_TRACE)
 					p_resp = True
 					if not "game_name" in p_data:
-						sendErrorToClient(client, ERROR_MGAME_MISSGAMENAME, resp_lng)# Game management error: miss game name
+						sendErrorToClient(client, ERROR_GAME_MISSGAMENAME, resp_lng)# Game error: miss game name
 						continue
 					g_name = p_data["game_name"]
 					
 					if not g_name in games_index:
-						sendErrorToClient(client, ERROR_MGAME_NONAMED, resp_lng)# Game management error: there is no game with this name
+						sendErrorToClient(client, ERROR_GAME_NONAMED, resp_lng)# Game error: there is no game with this name
 						continue
 					game = games_index[g_name]
 					
@@ -375,7 +340,7 @@ Options:\n\
 					if "admin_psw" in p_data:
 						g_admin_psw = p_data["admin_psw"]
 					if g_admin_psw != game.admin_psw:
-						sendErrorToClient(client, ERROR_MGAME_WRONGADMINPSW, resp_lng)# Game management error: wrong admin password
+						sendErrorToClient(client, ERROR_GAME_WRONGADMINPSW, resp_lng)# Game error: wrong admin password
 						continue
 					
 					g = p_data["edit_game"]
@@ -396,15 +361,16 @@ Options:\n\
 					resp["edited_game_info"] = {"name":game.name, "public":game.public, "creation_time":game.creation_time, "admin_name":game.admin_name, "admin_address":game.admin_address, "consts":game.C}
 				
 				if "rm_game" in p_data:
+					logPrint("Received remove game command", LOG_TRACE)
 					p_resp = True
 					
 					if not "game_name" in p_data:
-						sendErrorToClient(client, ERROR_MGAME_MISSGAMENAME, resp_lng)# Game management error: miss game name
+						sendErrorToClient(client, ERROR_GAME_MISSGAMENAME, resp_lng)# Game error: miss game name
 						continue
 					g_name = p_data["game_name"]
 					
 					if not g_name in games_index:
-						sendErrorToClient(client, ERROR_MGAME_NONAMED, resp_lng)# Game management error: there is no game with this name
+						sendErrorToClient(client, ERROR_GAME_NONAMED, resp_lng)# Game error: there is no game with this name
 						continue
 					game = games_index[g_name]
 					
@@ -412,7 +378,7 @@ Options:\n\
 					if "admin_psw" in p_data:
 						g_admin_psw = p_data["admin_psw"]
 					if g_admin_psw != game.admin_psw:
-						sendErrorToClient(client, ERROR_MGAME_WRONGADMINPSW, resp_lng)# Game management error: wrong admin password
+						sendErrorToClient(client, ERROR_GAME_WRONGADMINPSW, resp_lng)# Game error: wrong admin password
 						continue
 					
 					games_index.pop(game.name)
@@ -422,15 +388,16 @@ Options:\n\
 					resp["rm_game_done"] = True
 				
 				if "new_player" in p_data:
+					logPrint("Received new player command", LOG_TRACE)
 					p_resp = True
 					
 					if not "game_name" in p_data:
-						sendErrorToClient(client, ERROR_MGAME_MISSGAMENAME, resp_lng)# Game management error: miss game name
+						sendErrorToClient(client, ERROR_GAME_MISSGAMENAME, resp_lng)# Game error: miss game name
 						continue
 					g_name = p_data["game_name"]
 					
 					if not g_name in games_index:
-						sendErrorToClient(client, ERROR_MGAME_NONAMED, resp_lng)# Game management error: there is no game with this name
+						sendErrorToClient(client, ERROR_GAME_NONAMED, resp_lng)# Game error: there is no game with this name
 						continue
 					game = games_index[g_name]
 					
@@ -455,15 +422,16 @@ Options:\n\
 					resp["new_player_done"] = {"player_name":player.name, "player_uid":player.uid, "player_address":player.address[0], "player_port":player.address[1]}
 				
 				if "rm_player" in p_data:
+					logPrint("Received remove player command", LOG_TRACE)
 					p_resp = True
 					
 					if not "game_name" in p_data:
-						sendErrorToClient(client, ERROR_MGAME_MISSGAMENAME, resp_lng)# Game management error: miss game name
+						sendErrorToClient(client, ERROR_GAME_MISSGAMENAME, resp_lng)# Game error: miss game name
 						continue
 					g_name = p_data["game_name"]
 					
 					if not g_name in games_index:
-						sendErrorToClient(client, ERROR_MGAME_NONAMED, resp_lng)# Game management error: there is no game with this name
+						sendErrorToClient(client, ERROR_GAME_NONAMED, resp_lng)# Game error: there is no game with this name
 						continue
 					game = games_index[g_name]
 					
@@ -474,21 +442,21 @@ Options:\n\
 						g_player_uid = g["player_uid"]
 					
 					if not g_player_uid in game.players_index:
-						sendErrorToClient(client, ERROR_MGAME_PLAYERNOEXIST, resp_lng)# Game management error: that player does not exist
+						sendErrorToClient(client, ERROR_GAME_PLAYERNOEXIST, resp_lng)# Game error: that player does not exist
 						continue
 					
 					if "admin_psw" in g:
 						g_admin_psw = g["admin_psw"]
 						if g_admin_psw != game.admin_psw:
-							sendErrorToClient(client, ERROR_MGAME_WRONGADMINPSW, resp_lng)# Game management error: wrong admin password
+							sendErrorToClient(client, ERROR_GAME_WRONGADMINPSW, resp_lng)# Game error: wrong admin password
 							continue
 					elif "player_psw" in g:
 						g_player_psw = g["player_psw"]
 						if g_player_psw != game.players_index[g_player_uid].psw:
-							sendErrorToClient(client, ERROR_MGAME_WRONGPLAYERPSW, resp_lng)# Game management error: wrong player password
+							sendErrorToClient(client, ERROR_GAME_WRONGPLAYERPSW, resp_lng)# Game error: wrong player password
 							continue
 					else:
-						sendErrorToClient(client, ERROR_MGAME_MISSPLAYERPSW, resp_lng)# Game management error: miss player password
+						sendErrorToClient(client, ERROR_GAME_MISSPLAYERPSW, resp_lng)# Game error: miss player password
 						continue
 					
 					player = game.removePlayer(g_player_uid)
@@ -496,6 +464,45 @@ Options:\n\
 					resp["rm_player_done"] = {"player_name":player.name, "player_uid":player.uid, "player_address":player.address[0], "player_port":player.address[1]}
 					
 					player = None
+				
+				if "exchange" in p_data:
+					logPrint("Received exchange command", LOG_TRACE)
+					p_resp = True
+					
+					if not "game_name" in p_data:
+						sendErrorToClient(client, ERROR_GAME_MISSGAMENAME, resp_lng)# Game error: miss game name
+						continue
+					g_name = p_data["game_name"]
+					
+					if not g_name in games_index:
+						sendErrorToClient(client, ERROR_GAME_NONAMED, resp_lng)# Game error: there is no game with this name
+						continue
+					game = games_index[g_name]
+					
+					g = p_data["exchange"]
+					
+					g_player_uid = None
+					if "player_uid" in g:
+						g_player_uid = g["player_uid"]
+					
+					if not g_player_uid in game.players_index:
+						sendErrorToClient(client, ERROR_GAME_PLAYERNOEXIST, resp_lng)# Game error: that player does not exist
+						continue
+					
+					if "player_psw" in g:
+						g_player_psw = g["player_psw"]
+						if g_player_psw != game.players_index[g_player_uid].psw:
+							sendErrorToClient(client, ERROR_GAME_WRONGPLAYERPSW, resp_lng)# Game error: wrong player password
+							continue
+					else:
+						sendErrorToClient(client, ERROR_GAME_MISSPLAYERPSW, resp_lng)# Game error: miss player password
+						continue
+					
+					if not "exchange_data" in g:
+						sendErrorToClient(client, ERROR_GAME_MISSEXCHDATA, resp_lng)# Game error: miss exchange data
+						continue
+					
+					# TODO: check data, add to exchanges list, confirm, apply
 			
 			else:
 				sendErrorToClient(client, ERROR_COM_LANGUAGE, resp_lng)# Communication error: unknown language
@@ -504,6 +511,6 @@ Options:\n\
 		if p_resp:
 			if resp_lng == "json":
 				resp_raw = json.dumps(resp).encode()
-			client.sendall(resp_raw)
+			client.sendall(encodeData(resp_raw, resp_lng))
 		
 		client.close()

testclient.py

@@ -4,7 +4,7 @@ from utils import *
 
 PROTOCOL_VERSION = b"geco0"
 PROTOCOL_LANG = b"json"
-BUFFER = 1024
+RECBUF = 1024
 ADDR = socket.gethostname()
 
 # Default game constants
@@ -70,8 +70,66 @@ def sdata(data, response_intended, lng="json"):
 	sock.sendall(msg)
 	resp = None
 	if response_intended:
-		resp = sock.recv(BUFFER)
-	sock.close()
+		paquet = b""
+		p_len_tmp = ""
+		p_len = None
+		p_data_index = None
+		i = 0
+		while True:
+			try:
+				raw = sock.recv(RECBUF)
+			except socket.timeout:
+				break
+			if raw:
+				for c in raw:
+					if p_len == None:
+						if c == 10:# LF
+							p_len = int(p_len_tmp, 16)
+							p_data_index = len(paquet)+1
+						elif (c >= 48 and c <= 57) or (c >= 97 and c <= 102) or (c >= 65 and c <= 70):# [0-9a-fA-F]
+							p_len_tmp += chr(c)
+						else:
+							p_len_tmp = ""
+					else:
+						i += 1
+					paquet += bytes([c])
+				if p_len != None and i >= p_len:
+					break
+			else:
+				break
+		sock.close()
+		
+		# Parse paquet
+		try:
+			seps = [paquet.index(b"/")]
+			p_ver = paquet[:seps[0]]# protocol version
+			if p_ver != PROTOCOL_VERSION:
+				print("Communication error: unsupported protocol version");
+				return None
+			seps.append(paquet.index(b"/", seps[0]+1))
+			seps.append(paquet.index(b"\n", seps[1]+1))
+		except ValueError:
+			print("Communication error: decoding header");
+			return None
+		
+		p_lng = paquet[seps[0]+1:seps[1]]# data language
+		
+		if p_len > 0:
+			p_raw = paquet[p_data_index:]
+			
+			if p_lng == b"json":
+				try:
+					p_data = json.loads(p_raw)
+				except json.JSONDecodeError:
+					print("Communication error: decoding JSON");
+					return None
+				resp = str(p_data)
+			
+			elif p_lng == b"raw":
+				resp = p_raw
+	
+	else:
+		sock.close()
 	return resp
 
 def info():
@@ -113,6 +171,13 @@ def removeplayer(name="Test game", player_uid=1, player_psw="", admin_psw=None):
 	else:
 		return sdata({"game_name":name, "rm_player":{"player_uid":player_uid, "player_psw":player_psw}}, True)
 
+def getsource(outfile="serversourcecode.tar.gz"):
+	"""Request for source code"""
+	f = open(outfile, "wb")
+	f.write(sdata({"source":True}, True))
+	f.close()
+	return outfile
+
 def h():
 	"""Show help"""
 	help("__main__")

utils.py

@@ -17,20 +17,53 @@
 	along with Pygeconomicus-server.  If not, see <https://www.gnu.org/licenses/>.
 """
 
+import configparser, socket, json, os, time, random, sys
+
 ERROR_OK = 0
 ERROR_COM_HEADER = 16
 ERROR_COM_PROTOCOL = 17
 ERROR_COM_LANGUAGE = 18
 ERROR_COM_JSON = 19
-ERROR_MGAME_USEDGAMENAME = 48
-ERROR_MGAME_MISSNEWGAMENAME = 49
-ERROR_MGAME_MISSGAMENAME = 50
-ERROR_MGAME_NONAMED = 51
-ERROR_MGAME_MISSADMINPSW = 52
-ERROR_MGAME_WRONGADMINPSW = 53
-ERROR_MGAME_PLAYERNOEXIST = 54
-ERROR_MGAME_WRONGPLAYERPSW = 55
-ERROR_MGAME_MISSPLAYERPSW = 56
+ERROR_GAME_USEDGAMENAME = 48
+ERROR_GAME_MISSNEWGAMENAME = 49
+ERROR_GAME_MISSGAMENAME = 50
+ERROR_GAME_NONAMED = 51
+ERROR_GAME_MISSADMINPSW = 52
+ERROR_GAME_WRONGADMINPSW = 53
+ERROR_GAME_PLAYERNOEXIST = 54
+ERROR_GAME_WRONGPLAYERPSW = 55
+ERROR_GAME_MISSPLAYERPSW = 56
+ERROR_GAME_MISSEXCHDATA = 57
+ERROR_SRV_NOSOURCE = 128
+
+LOG_INFO = 1
+LOG_TRACE = 2
+LOG_WARN = 3
+LOG_ERROR = 4
+LOGMSG_TYPES = {LOG_INFO:"\033[96minfo\033[0m", LOG_TRACE:"\033[39mtrace\033[0m", LOG_WARN:"\033[93mwarn\033[0m", LOG_ERROR:"\033[91merror\033[0m"}
+
+# Default game constants
+CONSTS = {
+	"N_VALUES": 4, # number of values types
+	"N_WVALUES": 1, # number of waiting values types
+	"TURN_DURATION": 300, # in seconds
+	"N_TURNS": 10, # number of turns in a game
+	"TURN_YEARS": 8, # number of years by turn
+	"LIFESPAN": 10, # max age
+	"N_DIGITS": 0, # number of decimals
+	"START_VALUES": 4 # number of random values for beginning
+}
+
+# Default server constants
+PATH_CONF = "server.ini" # config file relative path
+RECBUF = 1024 # reception buffer length
+PROTOCOL_VERSIONS = ["geco0"]# supported protocol versions
+DEFAULT_PROTOCOL = "geco0"
+VERSION = "0.0.0"
+HOST = socket.gethostname() # server host name
+PORT = 8651 # server port
+SOURCE_FILES = ["server.py", "money_free.py", "money_debt.py", "utils.py", "README.md", "LICENSE"]
+SOURCE_ARCHIVE = "sourcecode.tar.gz"
 
 # Server functions
 
@@ -40,6 +73,41 @@ def getargv(argv, arg, default=""):
 	else:
 		return default
 
+def readConfig():
+	conf = configparser.ConfigParser()
+	conf.read(PATH_CONF)
+	if "Server" in conf:
+		if "Host" in conf["Server"]:
+			host = conf["Server"]["Host"]
+		if "Port" in conf["Server"]:
+			port = int(conf["Server"]["Port"])
+	if "Game" in conf:
+		for key, value in conf["Game"].items():
+			CONSTS[key] = value
+
+def encodeData(raw, lng="json", protocol=DEFAULT_PROTOCOL):
+	return protocol.encode()+b"/"+lng.encode()+b"/"+hex(len(raw))[2:].encode()+b"\n"+raw
+
+def sendErrorToClient(client, errcode, resp_lng="json"):
+	resp_raw = b""
+	if resp_lng == "json":
+		resp_raw = json.dumps({"error":errcode}).encode()
+	client.sendall(encodeData(resp_raw))
+	client.close()
+	logPrint("Sent error "+str(errcode)+" to client", LOG_TRACE)
+
+def tarSource():
+	import tarfile
+	def tarReset(tarinfo):
+		tarinfo.uid = tarinfo.gid = 0
+		tarinfo.uname = tarinfo.gname = "root"
+		return tarinfo
+	tar = tarfile.open(SOURCE_ARCHIVE, "w:gz")
+	for source_file in SOURCE_FILES:
+		tar.add(source_file, filter=tarReset)
+	tar.close()
+	logPrint("Source archive created at '"+SOURCE_ARCHIVE+"'", LOG_INFO)
+
 # Money functions