1 """ TCP server that communicates with terminals """
3 from configparser import ConfigParser
4 from logging import getLogger
14 from struct import pack
16 from typing import Dict, List, Optional, Tuple
20 from .gps303proto import (
27 from .zmsg import Bcast, Resp
29 log = getLogger("gps303/collector")
35 """Connected socket to the terminal plus buffer and metadata"""
37 def __init__(self, sock: socket, addr: Tuple[str, int]) -> None:
41 self.imei: Optional[str] = None
43 def close(self) -> None:
44 log.debug("Closing fd %d (IMEI %s)", self.sock.fileno(), self.imei)
48 def recv(self) -> Optional[List[Tuple[float, Tuple[str, int], bytes]]]:
49 """Read from the socket and parse complete messages"""
51 segment = self.sock.recv(MAXBUFFER)
54 "Reading from fd %d (IMEI %s): %s",
60 if not segment: # Terminal has closed connection
62 "EOF reading from fd %d (IMEI %s)",
68 self.buffer += segment
69 if len(self.buffer) > MAXBUFFER:
70 # We are receiving junk. Let's drop it or we run out of memory.
71 log.warning("More than %d unparseable data, dropping", MAXBUFFER)
75 framestart = self.buffer.find(b"xx")
76 if framestart == -1: # No frames, return whatever we have
78 if framestart > 0: # Should not happen, report
80 'Undecodable data (%d) "%s" from fd %d (IMEI %s)',
82 self.buffer[:framestart][:64].hex(),
86 self.buffer = self.buffer[framestart:]
87 # At this point, buffer starts with a packet
88 if len(self.buffer) < 6: # no len and proto - cannot proceed
90 exp_end = self.buffer[2] + 3 # Expect '\r\n' here
92 # Length field can legitimeely be much less than the
93 # length of the packet (e.g. WiFi positioning), but
94 # it _should not_ be greater. Still sometimes it is.
95 # Luckily, not by too much: by maybe two or three bytes?
96 # Do this embarrassing hack to avoid accidental match
97 # of some binary data in the packet against '\r\n'.
99 frameend = self.buffer.find(b"\r\n", frameend + 1)
100 if frameend == -1 or frameend >= (
102 ): # Found realistic match or none
104 if frameend == -1: # Incomplete frame, return what we have
106 packet = self.buffer[2:frameend]
107 self.buffer = self.buffer[frameend + 2 :]
108 if len(packet) < 2: # frameend comes too early
109 log.warning("Packet too short: %s", packet)
111 if proto_of_message(packet) == LOGIN.PROTO:
112 msg = parse_message(packet)
113 if isinstance(msg, LOGIN): # Can be unparseable
116 "LOGIN from fd %d (IMEI %s)",
120 msgs.append((when, self.addr, packet))
123 def send(self, buffer: bytes) -> None:
125 self.sock.send(b"xx" + buffer + b"\r\n")
128 "Sending to fd %d (IMEI %s): %s",
136 def __init__(self) -> None:
137 self.by_fd: Dict[int, Client] = {}
138 self.by_imei: Dict[str, Client] = {}
140 def add(self, clntsock: socket, clntaddr: Tuple[str, int]) -> int:
141 fd = clntsock.fileno()
142 log.info("Start serving fd %d from %s", fd, clntaddr)
143 self.by_fd[fd] = Client(clntsock, clntaddr)
146 def stop(self, fd: int) -> None:
147 clnt = self.by_fd[fd]
148 log.info("Stop serving fd %d (IMEI %s)", clnt.sock.fileno(), clnt.imei)
151 del self.by_imei[clnt.imei]
156 ) -> Optional[List[Tuple[Optional[str], float, Tuple[str, int], bytes]]]:
157 clnt = self.by_fd[fd]
162 for when, peeraddr, packet in msgs:
163 if proto_of_message(packet) == LOGIN.PROTO: # Could do blindly...
165 self.by_imei[clnt.imei] = clnt
168 "Login message from %s: %s, but client imei unfilled",
172 result.append((clnt.imei, when, peeraddr, packet))
174 "Received from %s (IMEI %s): %s",
181 def response(self, resp: Resp) -> None:
182 if resp.imei in self.by_imei:
183 self.by_imei[resp.imei].send(resp.packet)
185 log.info("Not connected (IMEI %s)", resp.imei)
188 def runserver(conf: ConfigParser, handle_hibernate: bool = True) -> None:
189 # Is this https://github.com/zeromq/pyzmq/issues/1627 still not fixed?!
190 zctx = zmq.Context() # type: ignore
191 zpub = zctx.socket(zmq.PUB) # type: ignore
192 zpull = zctx.socket(zmq.PULL) # type: ignore
193 oldmask = umask(0o117)
194 zpub.bind(conf.get("collector", "publishurl"))
195 zpull.bind(conf.get("collector", "listenurl"))
197 tcpl = socket(AF_INET6, SOCK_STREAM)
198 tcpl.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
199 tcpl.bind(("", conf.getint("collector", "port")))
201 tcpfd = tcpl.fileno()
202 poller = zmq.Poller() # type: ignore
203 poller.register(zpull, flags=zmq.POLLIN)
204 poller.register(tcpfd, flags=zmq.POLLIN)
211 events = poller.poll(1000)
212 for sk, fl in events:
216 msg = zpull.recv(zmq.NOBLOCK)
222 clntsock, clntaddr = tcpl.accept()
223 clntsock.setsockopt(SOL_SOCKET, SO_KEEPALIVE, 1)
224 topoll.append((clntsock, clntaddr))
225 elif fl & zmq.POLLIN:
226 received = clients.recv(sk)
228 log.debug("Terminal gone from fd %d", sk)
231 for imei, when, peeraddr, packet in received:
232 proto = proto_of_message(packet)
242 if proto == HIBERNATION.PROTO and handle_hibernate:
244 "HIBERNATION from fd %d (IMEI %s)",
249 respmsg = inline_response(packet)
250 if respmsg is not None:
252 Resp(imei=imei, when=when, packet=respmsg)
255 log.debug("Stray event: %s on socket %s", fl, sk)
256 # poll queue consumed, make changes now
261 proto=proto_of_message(zmsg.packet),
267 log.debug("Sending to the client: %s", zmsg)
268 clients.response(zmsg)
270 poller.unregister(fd) # type: ignore
272 for clntsock, clntaddr in topoll:
273 fd = clients.add(clntsock, clntaddr)
274 poller.register(fd, flags=zmq.POLLIN)
275 except KeyboardInterrupt:
278 zctx.destroy() # type: ignore
282 if __name__.endswith("__main__"):
283 runserver(common.init(log))