""" TCP server that communicates with terminals """
+from configparser import ConfigParser
+from importlib import import_module
from logging import getLogger
-from socket import socket, AF_INET6, SOCK_STREAM, SOL_SOCKET, SO_REUSEADDR
-from time import time
+from os import umask
+from socket import (
+ socket,
+ AF_INET6,
+ SOCK_STREAM,
+ SOL_SOCKET,
+ SO_KEEPALIVE,
+ SO_REUSEADDR,
+)
from struct import pack
+from time import time
+from typing import Any, cast, Dict, List, Optional, Tuple, Union
import zmq
from . import common
-from .gps303proto import (
- HIBERNATION,
- LOGIN,
- inline_response,
- parse_message,
- proto_of_message,
-)
from .zmsg import Bcast, Resp
log = getLogger("gps303/collector")
+MAXBUFFER: int = 4096
+
+
+class ProtoModule:
+ class Stream:
+ @staticmethod
+ def enframe(buffer: bytes) -> bytes:
+ ...
+
+ def recv(self, segment: bytes) -> List[Union[bytes, str]]:
+ ...
+
+ def close(self) -> bytes:
+ ...
+
+ @staticmethod
+ def probe_buffer(buffer: bytes) -> bool:
+ ...
+
+ @staticmethod
+ def parse_message(packet: bytes, is_incoming: bool = True) -> Any:
+ ...
+
+ @staticmethod
+ def inline_response(packet: bytes) -> Optional[bytes]:
+ ...
+
+ @staticmethod
+ def is_goodbye_packet(packet: bytes) -> bool:
+ ...
+
+ @staticmethod
+ def imei_from_packet(packet: bytes) -> Optional[str]:
+ ...
+
+ @staticmethod
+ def proto_of_message(packet: bytes) -> str:
+ ...
+
+ @staticmethod
+ def proto_by_name(name: str) -> int:
+ ...
+
+
+pmods: List[ProtoModule] = []
+
class Client:
"""Connected socket to the terminal plus buffer and metadata"""
- def __init__(self, sock, addr):
+ def __init__(self, sock: socket, addr: Tuple[str, int]) -> None:
self.sock = sock
self.addr = addr
- self.buffer = b""
- self.imei = None
+ self.pmod: Optional[ProtoModule] = None
+ self.stream: Optional[ProtoModule.Stream] = None
+ self.imei: Optional[str] = None
- def close(self):
+ def close(self) -> None:
log.debug("Closing fd %d (IMEI %s)", self.sock.fileno(), self.imei)
self.sock.close()
- self.buffer = b""
- self.imei = None
+ if self.stream:
+ rest = self.stream.close()
+ else:
+ rest = b""
+ if rest:
+ log.warning(
+ "%d bytes in buffer on close: %s", len(rest), rest[:64].hex()
+ )
- def recv(self):
+ def recv(self) -> Optional[List[Tuple[float, Tuple[str, int], bytes]]]:
"""Read from the socket and parse complete messages"""
try:
- segment = self.sock.recv(4096)
- except OSError:
+ segment = self.sock.recv(MAXBUFFER)
+ except OSError as e:
log.warning(
"Reading from fd %d (IMEI %s): %s",
self.sock.fileno(),
self.imei,
)
return None
+ if self.stream is None:
+ for pmod in pmods:
+ if pmod.probe_buffer(segment):
+ self.pmod = pmod
+ self.stream = pmod.Stream()
+ break
+ if self.stream is None:
+ log.info(
+ "unrecognizable %d bytes of data %s from fd %d",
+ len(segment),
+ segment[:32].hex(),
+ self.sock.fileno(),
+ )
+ return []
when = time()
- self.buffer += segment
msgs = []
- while True:
- framestart = self.buffer.find(b"xx")
- if framestart == -1: # No frames, return whatever we have
- break
- if framestart > 0: # Should not happen, report
+ for elem in self.stream.recv(segment):
+ if isinstance(elem, bytes):
+ msgs.append((when, self.addr, elem))
+ else:
log.warning(
- 'Undecodable data "%s" from fd %d (IMEI %s)',
- self.buffer[:framestart].hex(),
+ "%s from fd %d (IMEI %s)",
+ elem,
self.sock.fileno(),
self.imei,
)
- self.buffer = self.buffer[framestart:]
- # At this point, buffer starts with a packet
- frameend = self.buffer.find(b"\r\n", 4)
- if frameend == -1: # Incomplete frame, return what we have
- break
- packet = self.buffer[2:frameend]
- self.buffer = self.buffer[frameend + 2 :]
- if proto_of_message(packet) == LOGIN.PROTO:
- self.imei = parse_message(packet).imei
- log.info(
- "LOGIN from fd %d (IMEI %s)", self.sock.fileno(), self.imei
- )
- msgs.append((when, self.addr, packet))
return msgs
- def send(self, buffer):
+ def send(self, buffer: bytes) -> None:
+ assert self.stream is not None
try:
- self.sock.send(b"xx" + buffer + b"\r\n")
+ self.sock.send(self.stream.enframe(buffer))
except OSError as e:
log.error(
"Sending to fd %d (IMEI %s): %s",
- self.sock.fileno,
+ self.sock.fileno(),
self.imei,
e,
)
class Clients:
- def __init__(self):
- self.by_fd = {}
- self.by_imei = {}
+ def __init__(self) -> None:
+ self.by_fd: Dict[int, Client] = {}
+ self.by_imei: Dict[str, Client] = {}
- def add(self, clntsock, clntaddr):
+ def add(self, clntsock: socket, clntaddr: Tuple[str, int]) -> int:
fd = clntsock.fileno()
+ log.info("Start serving fd %d from %s", fd, clntaddr)
self.by_fd[fd] = Client(clntsock, clntaddr)
return fd
- def stop(self, fd):
+ def stop(self, fd: int) -> None:
clnt = self.by_fd[fd]
log.info("Stop serving fd %d (IMEI %s)", clnt.sock.fileno(), clnt.imei)
clnt.close()
del self.by_imei[clnt.imei]
del self.by_fd[fd]
- def recv(self, fd):
+ def recv(
+ self, fd: int
+ ) -> Optional[
+ List[Tuple[ProtoModule, Optional[str], float, Tuple[str, int], bytes]]
+ ]:
clnt = self.by_fd[fd]
msgs = clnt.recv()
if msgs is None:
return None
result = []
for when, peeraddr, packet in msgs:
- if proto_of_message(packet) == LOGIN.PROTO: # Could do blindly...
- self.by_imei[clnt.imei] = clnt
- result.append((clnt.imei, when, peeraddr, packet))
+ assert clnt.pmod is not None
+ if clnt.imei is None:
+ imei = clnt.pmod.imei_from_packet(packet)
+ if imei is not None:
+ log.info("LOGIN from fd %d (IMEI %s)", fd, imei)
+ clnt.imei = imei
+ oldclnt = self.by_imei.get(clnt.imei)
+ if oldclnt is not None:
+ log.info(
+ "Orphaning fd %d with the same IMEI",
+ oldclnt.sock.fileno(),
+ )
+ oldclnt.imei = None
+ self.by_imei[clnt.imei] = clnt
+ else:
+ log.warning(
+ "Login message from %s: %s, but client imei unfilled",
+ peeraddr,
+ packet,
+ )
+ result.append((clnt.pmod, clnt.imei, when, peeraddr, packet))
+ log.debug(
+ "Received from %s (IMEI %s): %s",
+ peeraddr,
+ clnt.imei,
+ packet.hex(),
+ )
return result
- def response(self, resp):
+ def response(self, resp: Resp) -> Optional[ProtoModule]:
if resp.imei in self.by_imei:
- self.by_imei[resp.imei].send(resp.packet)
+ clnt = self.by_imei[resp.imei]
+ clnt.send(resp.packet)
+ return clnt.pmod
+ else:
+ log.info("Not connected (IMEI %s)", resp.imei)
+ return None
-def runserver(conf):
- zctx = zmq.Context()
- zpub = zctx.socket(zmq.PUB)
+def runserver(conf: ConfigParser, handle_hibernate: bool = True) -> None:
+ global pmods
+ pmods = [
+ cast(ProtoModule, import_module("." + modnm, __package__))
+ for modnm in conf.get("collector", "protocols").split(",")
+ ]
+ # Is this https://github.com/zeromq/pyzmq/issues/1627 still not fixed?!
+ zctx = zmq.Context() # type: ignore
+ zpub = zctx.socket(zmq.PUB) # type: ignore
+ zpull = zctx.socket(zmq.PULL) # type: ignore
+ oldmask = umask(0o117)
zpub.bind(conf.get("collector", "publishurl"))
- zsub = zctx.socket(zmq.SUB)
- zsub.connect(conf.get("collector", "listenurl"))
+ zpull.bind(conf.get("collector", "listenurl"))
+ umask(oldmask)
tcpl = socket(AF_INET6, SOCK_STREAM)
tcpl.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
tcpl.bind(("", conf.getint("collector", "port")))
tcpl.listen(5)
tcpfd = tcpl.fileno()
- poller = zmq.Poller()
- poller.register(zsub, flags=zmq.POLLIN)
+ poller = zmq.Poller() # type: ignore
+ poller.register(zpull, flags=zmq.POLLIN)
poller.register(tcpfd, flags=zmq.POLLIN)
clients = Clients()
try:
tosend = []
topoll = []
tostop = []
- events = poller.poll(10)
+ events = poller.poll(1000)
for sk, fl in events:
- if sk is zsub:
+ if sk is zpull:
while True:
try:
- msg = zsub.recv(zmq.NOBLOCK)
- tosend.append(Resp(msg))
+ msg = zpull.recv(zmq.NOBLOCK)
+ zmsg = Resp(msg)
+ tosend.append(zmsg)
except zmq.Again:
break
elif sk == tcpfd:
clntsock, clntaddr = tcpl.accept()
+ clntsock.setsockopt(SOL_SOCKET, SO_KEEPALIVE, 1)
topoll.append((clntsock, clntaddr))
- else:
+ elif fl & zmq.POLLIN:
received = clients.recv(sk)
if received is None:
- log.debug(
- "Terminal gone from fd %d (IMEI %s)", sk, imei
- )
+ log.debug("Terminal gone from fd %d", sk)
tostop.append(sk)
else:
- for imei, when, peeraddr, packet in received:
- proto = proto_of_message(packet)
+ for pmod, imei, when, peeraddr, packet in received:
+ proto = pmod.proto_of_message(packet)
zpub.send(
Bcast(
proto=proto,
packet=packet,
).packed
)
- if proto == HIBERNATION.PROTO:
+ if (
+ pmod.is_goodbye_packet(packet)
+ and handle_hibernate
+ ):
log.debug(
- "HIBERNATION from fd %d (IMEI %s)",
+ "Goodbye from fd %d (IMEI %s)",
sk,
imei,
)
tostop.append(sk)
- respmsg = inline_response(packet)
+ respmsg = pmod.inline_response(packet)
if respmsg is not None:
- clients.response(
- Resp(imei=imei, packet=respmsg)
+ tosend.append(
+ Resp(imei=imei, when=when, packet=respmsg)
)
+ else:
+ log.debug("Stray event: %s on socket %s", fl, sk)
# poll queue consumed, make changes now
+ for zmsg in tosend:
+ log.debug("Sending to the client: %s", zmsg)
+ rpmod = clients.response(zmsg)
+ if rpmod is not None:
+ zpub.send(
+ Bcast(
+ is_incoming=False,
+ proto=rpmod.proto_of_message(zmsg.packet),
+ when=zmsg.when,
+ imei=zmsg.imei,
+ packet=zmsg.packet,
+ ).packed
+ )
for fd in tostop:
- poller.unregister(fd)
+ poller.unregister(fd) # type: ignore
clients.stop(fd)
- for zmsg in tosend:
- clients.response(zmsg)
for clntsock, clntaddr in topoll:
fd = clients.add(clntsock, clntaddr)
- poller.register(fd)
+ poller.register(fd, flags=zmq.POLLIN)
except KeyboardInterrupt:
- pass
+ zpub.close()
+ zpull.close()
+ zctx.destroy() # type: ignore
+ tcpl.close()
if __name__.endswith("__main__"):