python-talk/server.py

635 lines
28 KiB
Python
Executable file

#!/usr/bin/python3
import os, sys, asyncio, re, signal
from platform import uname
from traceback import format_exc
from logs import log
class LinkDownError(Exception): ...
class FailedLinkError(Exception): ...
class Globals: ...
TimeoutErrors = (TimeoutError, asyncio.exceptions.TimeoutError)
DisconnectErrors = (ConnectionResetError, BrokenPipeError, IndexError, *TimeoutErrors)
G = Globals()
G.uniqueClients = 0
G.servers = {}
G.clientsConnected = {}
port = 65048
G.msgs = []
G.remoteID = uname().node
G.event = asyncio.Event()
G.loop = asyncio.get_event_loop()
G.interruptCount = 0
G.killList = {}
G.outboundLinks = []
G.S2SLogs = []
G.cwlgd = False
saveLogs = True
address = "0.0.0.0"
# Try to load a message log, if one exists
try:
G.msgs = __import__("cache").msgs
log(f"Got {len(G.msgs)} lines from message cache")
except ImportError:
log("No server message cache.", level="WARN")
except Exception:
log(
"Abnormal state! Failed to load cache even though the file exists!",
level="WARN",
)
try:
filename = sys.argv.pop(0) # Ignore the filename
for arg in sys.argv:
if arg.startswith("--port") or arg.startswith("-p"):
port = int(arg.lstrip("-port="))
elif arg in ["-c", "--no-cache"]:
log("Explicitly erasing cached messages")
G.msgs = []
elif arg in ["-?", "-h", "--help"]:
filename = filename if filename.startswith("./") else "python3 " + filename
print(
f"""{filename} <args>
All arguments are optional!
All areguments are *expected* to only be specified once, if it appears mutliple times, the last one takes priority.
The exception to the above rule is `--link`, since you could want to link to multiple other servers.
Accepted arguments:
-?, -h, --help - Triggers this help dialog
-l, --no-logs - Disables the saving of logs when the server shuts down
-c, --no-cache - Disables the loading of cached messages when the server boots
-p<number>, --port=<number> - Sets the port for the server to use, defaults to `65048`
--link=<host>:<port> - Establishes an S2S link with remote server <host> on port <port> when the server starts up
--hostname=<string> - Sets the hostname for this server to use when talking to other servers. Defaults to the current system's hostname (limit of 16 chars)
--address=<IP> - Sets the IP to listen on, defaults to all addresses (0.0.0.0)
--cwlgd - Crashes the server when outbound links go down
Examples:
{filename} --hostname=Fun-chat --link=chat.example.com:65048 --port=92628
{filename} --no-logs --no-cache
{filename} --address=127.0.0.1 -l -p=7288"""
)
exit(0)
elif arg in ["-l", "--no-logs"]:
log("Explicitly disabling saving of logs!")
saveLogs = False
elif arg.startswith("--link"):
G.outboundLinks.append((arg[7:].split(":")[0], int(arg.split(":")[1])))
elif arg.startswith("--hostname"):
G.remoteID = arg[11:]
if not G.remoteID or len(G.remoteID) > 16:
raise ValueError
elif arg.startswith("--address"):
address = arg[9:]
elif arg.startswith("--cwlgd"):
G.cwlgd = True
log("Server will crasg when outbound links go down!", "WARN")
else:
log(f"Unrecognized argument {arg}!", "WARN")
except Exception:
sys.tracebacklimit = 0
raise ValueError("Invalid arguments. Please refer to --help for usage.") from None
if not saveLogs:
G.msgs.append(
b"[00-00-0000 00:00:00] Notice: Logging is disabled on this server instance!\n"
)
if len(G.remoteID) > 16:
G.remoteID = G.remoteID[:15]
def raw(string: str) -> str:
s = string.strip()
s = f"{s!r}"[1:-1].replace("\\\\", "\\")
if '"' in s:
return s.replace("\\'", "'")
else:
return s
def fmt(msg: str, name: str = "", action: bool = False) -> str:
if action:
return f"* {name}{' '*(20-len(name))} {msg}"
else:
return f" {name}{' '*(20-len(name))}: {msg}"
async def handleClient(reader, writer):
try:
name = ""
global G
writer.write(b"Please identify yourself. Nick limit is 20 chars.\n")
await writer.drain()
name = raw((await reader.read(20)).decode("utf8"))
if len(name) > 20:
name = name[
:19
] # Really this is only possible if someone passes raw unicode as a nick, but let's clean it up anyways.
try:
await asyncio.wait_for(
reader.read(), 0.01
) # Silently consume the excess username data
except TimeoutErrors:
pass
if not name:
writer.write(b"Nice try. Actually set a nick.\n")
await writer.drain()
writer.close()
await writer.wait_closed()
return
if name.lower() in G.clientsConnected:
writer.write(f"Nick ({name}) in use\n".encode("utf8"))
await writer.drain()
writer.close()
await writer.wait_closed()
return
if not name.startswith("S2S-"):
G.clientsConnected[name.lower()] = G.remoteID
msgIndex = 0
G.uniqueClients += 1
G.msgs.extend([log(f"{name} has connected to the server.")])
G.S2SLogs.append(("+", name, G.remoteID))
while 1:
try:
buffer = await asyncio.wait_for(reader.read(967), 0.1)
request = raw(buffer.decode("utf8"))
response = None
if request.startswith("/mes "):
response = log(f"* {name}'s {request[5:]}")
G.S2SLogs.append(("A", (name + "'s", request[5:]), G.remoteID))
elif request.startswith("/me "):
response = log(f"* {name} {request[4:]}")
G.S2SLogs.append(("A", (name, request[4:]), G.remoteID))
elif request.startswith("/h"):
writer.write(
b"""Command List:
/me <action> - Sends a special message so it looks like you did <action>
/mes <action> - Same as /me, but adds a 's onto your nick
/afk [reason] - Optional reason, short hand for `/me is afk [to [reason]]`
/h, /help - Triggers this command listing
/back - Shorthand for `/me is back`
/stats - Sends you some server stats
/quit - Disconnects you from the server\n"""
)
await writer.drain()
elif request.startswith("/stats"):
writer.write(
f"""Server stats:
Linked servers: {len(G.servers)}
Connected clients: {G.uniqueClients}
Total Clients: {len(G.clientsConnected)}
Messages sent: {len(G.msgs)}
Please note that this is not network level statistics.\n""".encode(
"utf8"
)
)
await writer.drain()
elif request.startswith("/quit"):
break
elif request.startswith("/afk"):
if len(request) > 5:
response = log(f"* {name} is afk to {request[5:]}")
G.S2SLogs.append(
("A", (name, f"is afk to {request[5:]}"), G.remoteID)
)
else:
response = log(f"* {name} is afk")
G.S2SLogs.append(("A", (name, "is afk"), G.remoteID))
elif request.startswith("/back"):
response = log(f"* {name} is back")
G.S2SLogs.append(("A", (name, "is back"), G.remoteID))
elif request:
response = log(f" {name}: {request}")
G.S2SLogs.append(("M", (name, request), G.remoteID))
if response:
G.msgs.append(response)
except TimeoutErrors:
pass
if msgIndex < len(G.msgs):
writer.writelines(G.msgs[msgIndex:])
await writer.drain()
msgIndex = len(G.msgs)
if name.lower() in G.killList and G.killList[name.lower()]:
writer.write(b"Your client has been killed by the server\n")
G.killList[name.lower()] = False
break
await writer.drain()
writer.close()
await writer.wait_closed()
G.uniqueClients -= 1
G.msgs.append(log(f"{name} has disconnected from the server."))
del G.clientsConnected[name.lower()]
G.S2SLogs.append(("-", name, G.remoteID))
else: # This is... probably a server?
sName = name[4:] # Trim off the S2S label
if (
G.servers.get(sName, False) != False
): # Have to explicitly check, empty list is False, but does not == False
writer.close()
await writer.wait_closed()
return # Server is already "linked", drop the connection
if G.remoteID == sName: # Hey! you can't *also* be ***me***!
writer.close()
await writer.wait_closed()
return # drop "us"
G.msgs.append(log(f"{sName} has linked to the network"))
G.servers[sName] = {}
msgIndex = 0
writer.write(b"I am awaiting your client listing.\n")
while 1:
client = raw((await reader.read(1024)).decode("utf8"))
if client == f"END OF CLIENT LISTING FROM {sName}":
break
if (
client.lower() in G.servers[sName]
or client.lower() in G.clientsConnected
):
writer.write(b"K Client rejected: Already exists\n")
await writer.drain()
continue
writer.write(b"I added that client.\n")
await writer.drain()
G.msgs.append(log(f"{client} has connected from {sName}"))
G.servers[sName][client.lower()] = False
G.S2SLogs.append(("+", client, sName))
writer.write(f"{G.remoteID}\n".encode("utf8"))
await writer.drain()
await reader.read(1024)
for client in G.clientsConnected:
writer.write(f"{client}\n".encode("utf8"))
await writer.drain()
resp = raw((await reader.read(1024)).decode("utf8"))
if resp.startswith("K"):
if G.clientsConnected[client] == G.remoteID:
G.killList[client] = True
else:
G.servers[G.clientsConnected[client]][client] = True
writer.write(f"END OF CLIENT LISTING FROM {G.remoteID}\n".encode("utf8"))
await writer.drain()
for client in G.servers[sName]:
G.clientsConnected[client] = sName
msgInd = len(G.S2SLogs)
while 1:
try:
rawMsg = await asyncio.wait_for(reader.read(967), 0.1)
buffer = raw(rawMsg.decode("utf8"))
match buffer[0]:
case "S": # Server notice
G.msgs.extend([log(buffer[2:])])
writer.write(b"I Mmm... Blueberries\n")
case "I":
pass
case "+":
cName = buffer[2:]
if cName.lower() not in G.clientsConnected:
G.msgs.append(
log(f"{cName} has connected from {sName}")
)
G.servers[sName][cName.lower()] = False
G.clientsConnected[cName.lower()] = sName
G.S2SLogs.append(("+", cName, sName))
writer.write(b"I Mmm... Pineapples\n")
else:
writer.write(f"K {cName}\n".encode("utf8"))
case "-":
cName = buffer[2:]
if G.clientsConnected.get(cName.lower(), None) == sName:
G.msgs.append(
log(f"{cName} has disconnected from {sName}")
)
del G.servers[sName][cName.lower()]
del G.clientsConnected[cName.lower()]
G.S2SLogs.append(("-", cName, sName))
writer.write(b"I Mmm... Bananas\n")
else:
writer.write(
f"S Your server is LYING about who is connected to it. - {G.remoteID}, a fellow server\n".encode(
"utf8"
)
)
case "M":
cName = buffer[2:].split("|", 1)[0]
message = buffer[2:].split("|", 1)[1]
G.msgs.append(log(f" {cName}: {message}"))
G.S2SLogs.append(("M", (cName, message), sName))
writer.write(
b"I Get these damn heretic ghost clients out of my store so i can buy my cult candles in peace.\n"
)
case "A":
cName = buffer[2:].split("|", 1)[0]
message = buffer[2:].split("|", 1)[1]
G.msgs.append(log(f"* {cName} {message}"))
G.S2SLogs.append(("A", (cName, message), sName))
writer.write(b"I Mmm... Strawberries\n")
case "Q":
break
case "K":
cName = buffer[2:]
if G.clientsConnected[cName.lower()] == G.remoteID:
G.killList[cName.lower()] = True
else:
G.servers[G.clientsConnected[cName.lower()]][
cName.lower()
] = True
writer.write(b"I Mmm... Blood\n")
case _:
writer.write(
f"S Your server is doing drugs over here, sending me bullshit messages man - {G.remoteID}, A fellow server\n".encode(
"utf8"
)
)
log(
f"Recieved invalid message ({buffer}) from {sName}",
"WARN",
)
await writer.drain()
except TimeoutErrors:
pass
if any(G.servers[sName].values()):
for name in G.servers[sName]:
if G.servers[sName][name]:
writer.write(f"K {name}\n".encode("utf8"))
await writer.drain()
G.servers[sName][name] = False
while msgInd < len(G.S2SLogs):
type, data, server = G.S2SLogs[msgInd]
# match-case on type
if server != sName:
match type:
case "A":
nick, msg = data
writer.write(f"A {nick}|{msg}\n".encode("utf8"))
case "M":
nick, msg = data
writer.write(f"M {nick}|{msg}\n".encode("utf8"))
case "+":
writer.write(f"+ {data}\n".encode("utf8"))
case "-":
writer.write(f"- {data}\n".encode("utf8"))
case _:
pass
await writer.drain()
msgInd += 1
await writer.drain()
writer.close()
await writer.wait_closed()
for cName in G.servers[sName]:
G.msgs.append(log(f"{cName}'s server is going down"))
G.S2SLogs.append(("-", cName, sName))
del G.clientsConnected[cName.lower()]
del G.servers[sName]
G.msgs.append(log(f"{sName} has de-linked from the network"))
except DisconnectErrors:
if not name:
return
if not name.startswith("S2S-"):
G.uniqueClients -= 1
G.msgs.append(log(f"{name} has disconnected from the server."))
G.S2SLogs.append(("-", name, G.remoteID))
del G.clientsConnected[name.lower()]
else:
for cName in G.servers[name[4:]]:
G.msgs.append(log(f"{cName}'s server is going down"))
try:
del G.clientsConnected[cName.lower()]
G.S2SLogs.append(("-", cName, name[4:]))
except Exception: # Crash during connection sequence?
pass
del G.servers[name[4:]]
G.msgs.append(log(f"{name[4:]} has de-linked from the network"))
async def connectServer(hostname: str, port: int):
global G
try:
reader, writer = await asyncio.open_connection(hostname, port)
await reader.read(1024)
writer.write(f"S2S-{G.remoteID}\n".encode("utf8"))
await writer.drain()
await reader.read(1024)
for client in G.clientsConnected:
writer.write(f"{client}\n".encode("utf8"))
await writer.drain()
resp = raw((await reader.read(1024)).decode("utf8"))
if resp.startswith("K"):
if G.clientsConnected[client] == G.remoteID:
G.killList[client] = True
else:
G.servers[G.clientsConnected[client]][client] = True
writer.write(f"END OF CLIENT LISTING FROM {G.remoteID}\n".encode("utf8"))
await writer.drain()
rID = raw((await reader.read(16)).decode("utf8"))
try:
await asyncio.wait_for(reader.read(1024), 0.1)
except TimeoutErrors:
pass
if G.servers.get(rID, False) != False:
writer.close()
await writer.wait_closed()
return
if G.remoteID == rID:
writer.close()
await writer.wait_closed()
return
G.msgs.append(log(f"{rID} has linked to the network"))
G.servers[rID] = {}
writer.write(b"I recieved your remote ID, now awaiting client listing\n")
await writer.drain()
# recieve client list from the other server
while 1:
client = raw((await reader.read(1024)).decode("utf8"))
if client == f"END OF CLIENT LISTING FROM {rID}":
break
if client.lower() in G.servers[rID] or client.lower() in G.clientsConnected:
writer.write(b"K Client rejected: Already exists\n")
await writer.drain()
continue
writer.write(b"I added that client.\n")
await writer.drain()
G.msgs.append(log(f"{client} has connected from {rID}"))
G.servers[rID][client.lower()] = False
for client in G.servers[rID]:
G.clientsConnected[client] = rID
msgInd = len(G.S2SLogs)
try:
while 1:
try:
rawMsg = await asyncio.wait_for(reader.read(967), 0.1)
buffer = raw(rawMsg.decode("utf8"))
match buffer[0]:
case "S":
G.msgs.extend([log(buffer[2:])])
writer.write(b"I Mmm... Blueberries\n")
case "I":
pass
case "+":
cName = buffer[2:]
if cName.lower() not in G.clientsConnected:
G.msgs.append(log(f"{cName} has connected from {rID}"))
G.S2SLogs.append(("+", cName, rID))
G.servers[rID][cName.lower()] = False
G.clientsConnected[cName.lower()] = rID
writer.write(b"I Mmm... Pineapples\n")
else:
writer.write(f"K {cName}\n".encode("utf8"))
case "-":
cName = buffer[2:]
if G.clientsConnected.get(cName.lower(), None) == rID:
G.msgs.append(
log(f"{cName} has disconnected from {rID}")
)
del G.servers[rID][cName.lower()]
del G.clientsConnected[cName.lower()]
G.S2SLogs.append(("-", cName, rID))
else:
writer.write(
f"S Your server is LYING about who is connected to it. - {G.remoteID}, a fellow server\n".encode(
"utf8"
)
)
case "M":
cName = buffer[2:].split("|", 1)[0]
message = buffer[2:].split("|", 1)[1]
G.msgs.append(log(f" {cName}: {message}"))
G.S2SLogs.append(("M", (cName, message), rID))
writer.write(
b"I Get these damn heretic ghost clients out of my store so i can buy my cult candles in peace.\n"
)
case "A":
cName = buffer[2:].split("|", 1)[0]
message = buffer[2:].split("|", 1)[1]
G.S2SLogs.append(("A", (cName, message), rID))
G.msgs.append(log(f"* {cName} {message}"))
writer.write(b"I Mmm... Strawberries\n")
case "Q":
break
case "K":
cName = buffer[2:]
if G.clientsConnected[cName.lower()] == G.remoteID:
G.killList[cName.lower()] = True
else:
G.servers[G.clientsConnected[cName.lower()]][
cName.lower()
] = True
writer.write(b"I Mmm... Blood\n")
case _:
writer.write(
f"S Your server is doing drugs over here, sending me bullshit messages man - {G.remoteID}, A fellow server\n".encode(
"utf8"
)
)
log(
f"Recieved invalid message ({buffer}) from {sName}",
"WARN",
)
await writer.drain()
except TimeoutErrors:
pass
if any(G.servers[rID].values()):
for name in G.servers[rID]:
if G.servers[rID][name]:
writer.write(f"K {name}\n".encode("utf8"))
await writer.drain()
G.servers[rID][name] = False
while msgInd < len(G.S2SLogs):
type, data, server = G.S2SLogs[msgInd]
if server != rID:
match type:
case "A":
nick, msg = data
writer.write(f"A {nick}|{msg}\n".encode("utf8"))
case "M":
nick, msg = data
writer.write(f"M {nick}|{msg}\n".encode("utf8"))
case "+":
writer.write(f"+ {data}\n".encode("utf8"))
case "-":
writer.write(f"- {data}\n".encode("utf8"))
case _:
pass
await writer.drain()
msgInd += 1
if G.cwlgd:
raise LinkDownError
await writer.drain()
writer.close()
await writer.wait_closed()
for cName in G.servers[rID]:
G.msgs.append(log(f"{cName}'s server is going down"))
del G.clientsConnected[cName.lower()]
del G.servers[rID]
G.msgs.append(log(f"{rID} has de-linked from the network"))
except DisconnectErrors:
if G.cwlgd:
raise LinkDownError
for cName in G.servers[rID]:
G.msgs.append(log(f"{cName}'s server is going down"))
try:
del G.clientsConnected[cName.lower()]
except Exception:
pass
del G.servers[rID]
G.msgs.append(log(f"{rID} has de-linked from the network"))
except OSError as E:
log("OSError: " + str(E), "ERROR")
if G.cwlgd:
raise FailedLinkError
async def runServer(address: str, port: int):
global G
server = await asyncio.start_server(handleClient, address, port)
log(f"Listening on port {port}...")
G.msgs.append(log("Server startup"))
links = []
for hostname, portNum in G.outboundLinks:
links.append(connectServer(hostname, portNum))
crash = False
try:
links.append(G.event.wait())
await asyncio.gather(*links)
except LinkDownError:
G.msgs.append(log("Lost a server link, going down", "FATAL")[1:])
crash = True
except FailedLinkError:
G.msgs.append(log("Failed to establish a server link, going down", "FATAL")[1:])
except Exception:
crash = True
G.msgs.append(log("Server crash", "FATAL")[1:])
log("Shutting down from Exception", "FATAL")
Err = format_exc()
for line in Err.split("\n"):
log(line, "ERROR")
finally:
if not crash:
G.msgs.append(log("Server shutdown"))
log("Kicking all clients as we go down")
server.close()
# server.abort_clients()
if saveLogs:
with open("cache.py", "w") as cache:
cache.write(f"msgs = {G.msgs}\n")
log("Saved logs, exiting now.")
else:
log("Not saving logs, exiting now.")
class ServerInterruptException(KeyboardInterrupt): ...
def interruptCatch(s, f):
global G
print()
G.loop.call_soon_threadsafe(G.event.set)
G.interruptCount += 1
sys.tracebacklimit = 0
raise ServerInterruptException from None
signal.signal(signal.SIGINT, interruptCatch)
asyncio.run(runServer(address, port))