1 """ TCP server that communicates with terminals """
3 from configparser import ConfigParser
4 from logging import getLogger
6 from socket import socket, AF_INET6, SOCK_STREAM, SOL_SOCKET, SO_REUSEADDR
7 from struct import pack
9 from typing import Dict, List, Optional, Tuple
13 from .gps303proto import (
20 from .zmsg import Bcast, Resp
22 log = getLogger("gps303/collector")
26 """Connected socket to the terminal plus buffer and metadata"""
28 def __init__(self, sock: socket, addr: Tuple[str, int]) -> None:
32 self.imei: Optional[str] = None
34 def close(self) -> None:
35 log.debug("Closing fd %d (IMEI %s)", self.sock.fileno(), self.imei)
39 def recv(self) -> Optional[List[Tuple[float, Tuple[str, int], bytes]]]:
40 """Read from the socket and parse complete messages"""
42 segment = self.sock.recv(4096)
45 "Reading from fd %d (IMEI %s): %s",
51 if not segment: # Terminal has closed connection
53 "EOF reading from fd %d (IMEI %s)",
59 self.buffer += segment
62 framestart = self.buffer.find(b"xx")
63 if framestart == -1: # No frames, return whatever we have
65 if framestart > 0: # Should not happen, report
67 'Undecodable data "%s" from fd %d (IMEI %s)',
68 self.buffer[:framestart].hex(),
72 self.buffer = self.buffer[framestart:]
73 # At this point, buffer starts with a packet
74 if len(self.buffer) < 6: # no len and proto - cannot proceed
76 exp_end = self.buffer[2] + 3 # Expect '\r\n' here
78 # Length field can legitimeely be much less than the
79 # length of the packet (e.g. WiFi positioning), but
80 # it _should not_ be greater. Still sometimes it is.
81 # Luckily, not by too much: by maybe two or three bytes?
82 # Do this embarrassing hack to avoid accidental match
83 # of some binary data in the packet against '\r\n'.
85 frameend = self.buffer.find(b"\r\n", frameend)
86 if frameend >= (exp_end - 3): # Found realistic match
88 if frameend == -1: # Incomplete frame, return what we have
90 packet = self.buffer[2:frameend]
91 self.buffer = self.buffer[frameend + 2 :]
92 if proto_of_message(packet) == LOGIN.PROTO:
93 self.imei = parse_message(packet).imei
95 "LOGIN from fd %d (IMEI %s)", self.sock.fileno(), self.imei
97 msgs.append((when, self.addr, packet))
100 def send(self, buffer: bytes) -> None:
102 self.sock.send(b"xx" + buffer + b"\r\n")
105 "Sending to fd %d (IMEI %s): %s",
113 def __init__(self) -> None:
114 self.by_fd: Dict[int, Client] = {}
115 self.by_imei: Dict[str, Client] = {}
117 def add(self, clntsock: socket, clntaddr: Tuple[str, int]) -> int:
118 fd = clntsock.fileno()
119 log.info("Start serving fd %d from %s", fd, clntaddr)
120 self.by_fd[fd] = Client(clntsock, clntaddr)
123 def stop(self, fd: int) -> None:
124 clnt = self.by_fd[fd]
125 log.info("Stop serving fd %d (IMEI %s)", clnt.sock.fileno(), clnt.imei)
128 del self.by_imei[clnt.imei]
133 ) -> Optional[List[Tuple[Optional[str], float, Tuple[str, int], bytes]]]:
134 clnt = self.by_fd[fd]
139 for when, peeraddr, packet in msgs:
140 if proto_of_message(packet) == LOGIN.PROTO: # Could do blindly...
142 self.by_imei[clnt.imei] = clnt
145 "Login message from %s: %s, but client imei unfilled",
149 result.append((clnt.imei, when, peeraddr, packet))
151 "Received from %s (IMEI %s): %s",
158 def response(self, resp: Resp) -> None:
159 if resp.imei in self.by_imei:
160 self.by_imei[resp.imei].send(resp.packet)
162 log.info("Not connected (IMEI %s)", resp.imei)
165 def runserver(conf: ConfigParser) -> None:
166 # Is this https://github.com/zeromq/pyzmq/issues/1627 still not fixed?!
167 zctx = zmq.Context() # type: ignore
168 zpub = zctx.socket(zmq.PUB) # type: ignore
169 zpull = zctx.socket(zmq.PULL) # type: ignore
170 oldmask = umask(0o117)
171 zpub.bind(conf.get("collector", "publishurl"))
172 zpull.bind(conf.get("collector", "listenurl"))
174 tcpl = socket(AF_INET6, SOCK_STREAM)
175 tcpl.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
176 tcpl.bind(("", conf.getint("collector", "port")))
178 tcpfd = tcpl.fileno()
179 poller = zmq.Poller() # type: ignore
180 poller.register(zpull, flags=zmq.POLLIN)
181 poller.register(tcpfd, flags=zmq.POLLIN)
188 events = poller.poll(1000)
189 for sk, fl in events:
193 msg = zpull.recv(zmq.NOBLOCK)
199 clntsock, clntaddr = tcpl.accept()
200 topoll.append((clntsock, clntaddr))
201 elif fl & zmq.POLLIN:
202 received = clients.recv(sk)
204 log.debug("Terminal gone from fd %d", sk)
207 for imei, when, peeraddr, packet in received:
208 proto = proto_of_message(packet)
218 if proto == HIBERNATION.PROTO:
220 "HIBERNATION from fd %d (IMEI %s)",
225 respmsg = inline_response(packet)
226 if respmsg is not None:
228 Resp(imei=imei, when=when, packet=respmsg)
231 log.debug("Stray event: %s on socket %s", fl, sk)
232 # poll queue consumed, make changes now
234 poller.unregister(fd) # type: ignore
240 proto=proto_of_message(zmsg.packet),
246 log.debug("Sending to the client: %s", zmsg)
247 clients.response(zmsg)
248 for clntsock, clntaddr in topoll:
249 fd = clients.add(clntsock, clntaddr)
250 poller.register(fd, flags=zmq.POLLIN)
251 except KeyboardInterrupt:
255 if __name__.endswith("__main__"):
256 runserver(common.init(log))