from enum import Enum
from inspect import isclass
from struct import error, pack, unpack
+from time import time
from typing import (
Any,
Callable,
)
__all__ = (
+ "Stream",
"class_by_prefix",
"inline_response",
"parse_message",
+ "probe_buffer",
"proto_by_name",
+ "proto_name",
"DecodeError",
"Respond",
"GPS303Pkt",
"UNKNOWN_B3",
)
+PROTO_PREFIX = "ZX"
+
+### Deframer ###
+
+MAXBUFFER: int = 4096
+
+
+class Stream:
+ def __init__(self) -> None:
+ self.buffer = b""
+
+ @staticmethod
+ def enframe(buffer: bytes) -> bytes:
+ return b"xx" + buffer + b"\r\n"
+
+ def recv(self, segment: bytes) -> List[Union[bytes, str]]:
+ """
+ Process next segment of the stream. Return successfully deframed
+ packets as `bytes` and error messages as `str`.
+ """
+ when = time()
+ self.buffer += segment
+ if len(self.buffer) > MAXBUFFER:
+ # We are receiving junk. Let's drop it or we run out of memory.
+ self.buffer = b""
+ return [f"More than {MAXBUFFER} unparseable data, dropping"]
+ msgs: List[Union[bytes, str]] = []
+ 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
+ msgs.append(
+ f'Undecodable data ({framestart}) "{self.buffer[:framestart][:64].hex()}"'
+ )
+ self.buffer = self.buffer[framestart:]
+ # At this point, buffer starts with a packet
+ if len(self.buffer) < 6: # no len and proto - cannot proceed
+ break
+ exp_end = self.buffer[2] + 3 # Expect '\r\n' here
+ frameend = 0
+ # Length field can legitimeely be much less than the
+ # length of the packet (e.g. WiFi positioning), but
+ # it _should not_ be greater. Still sometimes it is.
+ # Luckily, not by too much: by maybe two or three bytes?
+ # Do this embarrassing hack to avoid accidental match
+ # of some binary data in the packet against '\r\n'.
+ while True:
+ frameend = self.buffer.find(b"\r\n", frameend + 1)
+ if frameend == -1 or frameend >= (
+ exp_end - 3
+ ): # Found realistic match or none
+ break
+ if frameend == -1: # Incomplete frame, return what we have
+ break
+ packet = self.buffer[2:frameend]
+ self.buffer = self.buffer[frameend + 2 :]
+ if len(packet) < 2: # frameend comes too early
+ msgs.append(f"Packet too short: {packet.hex()}")
+ else:
+ msgs.append(packet)
+ return msgs
+
+ def close(self) -> bytes:
+ ret = self.buffer
+ self.buffer = b""
+ return ret
+
+
+### Parser/Constructor ###
+
class DecodeError(Exception):
def __init__(self, e: Exception, **kwargs: Any) -> None:
setattr(self, k, v)
+def maybe(typ: type) -> Callable[[Any], Any]:
+ return lambda x: None if x is None else typ(x)
+
+
def intx(x: Union[str, int]) -> int:
if isinstance(x, str):
x = int(x, 0)
return x
+def boolx(x: Union[str, bool]) -> bool:
+ if isinstance(x, str):
+ if x.upper() in ("ON", "TRUE", "1"):
+ return True
+ if x.upper() in ("OFF", "FALSE", "0"):
+ return False
+ raise ValueError(str(x) + " could not be parsed as a Boolean")
+ return x
+
+
def hhmm(x: str) -> str:
"""Check for the string that represents hours and minutes"""
if not isinstance(x, str) or len(x) != 4:
return x
+def hhmmhhmm(x: str) -> str:
+ """Check for the string that represents hours and minutes twice"""
+ if not isinstance(x, str) or len(x) != 8:
+ raise ValueError(str(x) + " is not an eight-character string")
+ return hhmm(x[:4]) + hhmm(x[4:])
+
+
def l3str(x: Union[str, List[str]]) -> List[str]:
if isinstance(x, str):
lx = x.split(",")
return lx
+def l3alarms(x: Union[str, List[Tuple[int, str]]]) -> List[Tuple[int, str]]:
+ def alrmspec(sub: str) -> Tuple[int, str]:
+ if len(sub) != 7:
+ raise ValueError(sub + " does not represent day and time")
+ return (
+ {
+ "MON": 1,
+ "TUE": 2,
+ "WED": 3,
+ "THU": 4,
+ "FRI": 5,
+ "SAT": 6,
+ "SUN": 7,
+ }[sub[:3].upper()],
+ sub[3:],
+ )
+
+ if isinstance(x, str):
+ lx = [alrmspec(sub) for sub in x.split(",")]
+ else:
+ lx = x
+ lx.extend([(0, "0000") for _ in range(3 - len(lx))])
+ if len(lx) != 3 or any(d < 0 or d > 7 for d, tm in lx):
+ raise ValueError(str(lx) + " is a wrong alarms specification")
+ return [(d, hhmm(tm)) for d, tm in lx]
+
+
def l3int(x: Union[str, List[int]]) -> List[int]:
if isinstance(x, str):
lx = [int(el) for el in x.split(",")]
@property
def packed(self) -> bytes:
payload = self.encode()
- length = len(payload) + 1
+ length = getattr(self, "length", len(payload) + 1)
return pack("BB", length, self.PROTO) + payload
PROTO = 0x01
RESPOND = Respond.INL
# Default response for ACK, can also respond with STOP_UPLOAD
+ IN_KWARGS = (("imei", str, "0000000000000000"), ("ver", int, 0))
def in_decode(self, length: int, payload: bytes) -> None:
- self.imei = payload[:-1].hex()
- self.ver = unpack("B", payload[-1:])[0]
+ self.imei = payload[:8].ljust(8, b"\0").hex()
+ self.ver = payload[8]
+
+ def in_encode(self) -> bytes:
+ return bytes.fromhex(self.imei).ljust(8, b"\0")[:8] + pack(
+ "B", self.ver
+ )
class SUPERVISION(GPS303Pkt):
class STATUS(GPS303Pkt):
PROTO = 0x13
RESPOND = Respond.EXT
+ IN_KWARGS = (
+ ("batt", int, 100),
+ ("ver", int, 0),
+ ("timezone", int, 0),
+ ("intvl", int, 0),
+ ("signal", maybe(int), None),
+ )
OUT_KWARGS = (("upload_interval", int, 25),)
def in_decode(self, length: int, payload: bytes) -> None:
else:
self.signal = None
+ def in_encode(self) -> bytes:
+ return pack("BBBB", self.batt, self.ver, self.timezone, self.intvl) + (
+ b"" if self.signal is None else pack("B", self.signal)
+ )
+
def out_encode(self) -> bytes: # Set interval in minutes
return pack("B", self.upload_interval)
class HIBERNATION(GPS303Pkt): # Server can send to send devicee to sleep
PROTO = 0x14
+ def in_encode(self) -> bytes:
+ return b""
+
class RESET(GPS303Pkt):
# Device sends when it got reset SMS
class _WIFI_POSITIONING(GPS303Pkt):
+ IN_KWARGS: Tuple[Tuple[str, Callable[[Any], Any], Any], ...] = (
+ # IN_KWARGS = (
+ ("dtime", bytes, b"\0\0\0\0\0\0"),
+ ("wifi_aps", list, []),
+ ("mcc", int, 0),
+ ("mnc", int, 0),
+ ("gsm_cells", list, []),
+ )
+
def in_decode(self, length: int, payload: bytes) -> None:
self.dtime = payload[:6]
if self.dtime == b"\0\0\0\0\0\0":
)
self.gsm_cells.append((locac, cellid, -sigstr))
+ def in_encode(self) -> bytes:
+ self.length = len(self.wifi_aps)
+ return b"".join(
+ [
+ self.dtime,
+ b"".join(
+ [
+ bytes.fromhex(mac.replace(":", "")).ljust(6, b"\0")[:6]
+ + pack("B", -sigstr)
+ for mac, sigstr in self.wifi_aps
+ ]
+ ),
+ pack("!BHB", len(self.gsm_cells), self.mcc, self.mnc),
+ b"".join(
+ [
+ pack("!HHB", locac, cellid, -sigstr)
+ for locac, cellid, sigstr in self.gsm_cells
+ ]
+ ),
+ ]
+ )
+
class WIFI_OFFLINE_POSITIONING(_WIFI_POSITIONING):
PROTO = 0x17
class GPS_LBS_SWITCH_TIMES(GPS303Pkt):
PROTO = 0x34
- # Data is in packed decimal
- # 00/01 - GPS on/off
- # 00/01 - Don't set / Set upload period
- # HHMMHHMM - Upload period
- # 00/01 - LBS on/off
- # 00/01 - Don't set / Set time of boot
- # HHMM - Time of boot
- # 00/01 - Don't set / Set time of shutdown
- # HHMM - Time of shutdown
+ OUT_KWARGS = (
+ ("gps_off", boolx, False), # Clarify the meaning of 0/1
+ ("gps_interval_set", boolx, False),
+ ("gps_interval", hhmmhhmm, "00000000"),
+ ("lbs_off", boolx, False), # Clarify the meaning of 0/1
+ ("boot_time_set", boolx, False),
+ ("boot_time", hhmm, "0000"),
+ ("shut_time_set", boolx, False),
+ ("shut_time", hhmm, "0000"),
+ )
+
def out_encode(self) -> bytes:
- return b"" # TODO
+ return (
+ pack("B", self.gps_off)
+ + pack("B", self.gps_interval_set)
+ + bytes.fromhex(self.gps_interval)
+ + pack("B", self.lbs_off)
+ + pack("B", self.boot_time_set)
+ + bytes.fromhex(self.boot_time)
+ + pack("B", self.shut_time_set)
+ + bytes.fromhex(self.shut_time)
+ )
class _SET_PHONE(GPS303Pkt):
class ALARM_CLOCK(GPS303Pkt):
PROTO = 0x50
+ OUT_KWARGS: Tuple[
+ Tuple[str, Callable[[Any], Any], List[Tuple[int, str]]], ...
+ ] = (
+ ("alarms", l3alarms, []),
+ )
def out_encode(self) -> bytes:
- # TODO implement parsing kwargs
- alarms = ((0, "0000"), (0, "0000"), (0, "0000"))
return b"".join(
- pack("B", day) + bytes.fromhex(tm) for day, tm in alarms
+ pack("B", day) + bytes.fromhex(tm) for day, tm in self.alarms
)
+ [b";".join([el.encode() for el in self.phonenumbers])]
)
+ def in_encode(self) -> bytes:
+ return b""
+
class SYNCHRONOUS_WHITELIST(GPS303Pkt):
PROTO = 0x58
return CLASSES[proto]
+def proto_name(obj: Union[MetaPkt, GPS303Pkt]) -> str:
+ return (
+ PROTO_PREFIX
+ + ":"
+ + (
+ obj.__class__.__name__
+ if isinstance(obj, GPS303Pkt)
+ else obj.__name__
+ )
+ ).ljust(16, "\0")[:16]
+
+
def proto_by_name(name: str) -> int:
return PROTOS.get(name, -1)
-def proto_of_message(packet: bytes) -> int:
- return packet[1]
+def proto_of_message(packet: bytes) -> str:
+ return proto_name(CLASSES.get(packet[1], UNKNOWN))
+
+
+def imei_from_packet(packet: bytes) -> Optional[str]:
+ if packet[1] == LOGIN.PROTO:
+ msg = parse_message(packet)
+ if isinstance(msg, LOGIN):
+ return msg.imei
+ return None
+
+
+def is_goodbye_packet(packet: bytes) -> bool:
+ return packet[1] == HIBERNATION.PROTO
def inline_response(packet: bytes) -> Optional[bytes]:
- proto = proto_of_message(packet)
+ proto = packet[1]
if proto in CLASSES:
cls = CLASSES[proto]
if cls.RESPOND is Respond.INL:
return None
+def probe_buffer(buffer: bytes) -> bool:
+ framestart = buffer.find(b"xx")
+ if framestart < 0:
+ return False
+ if len(buffer) - framestart < 6:
+ return False
+ return True
+
+
def parse_message(packet: bytes, is_incoming: bool = True) -> GPS303Pkt:
"""From a packet (without framing bytes) derive the XXX.In object"""
length, proto = unpack("BB", packet[:2])
payload = packet[2:]
if proto not in CLASSES:
- cause: Union[DecodeError, ValueError] = ValueError(
+ cause: Union[DecodeError, ValueError, IndexError] = ValueError(
f"Proto {proto} is unknown"
)
else:
return CLASSES[proto].In(length, payload)
else:
return CLASSES[proto].Out(length, payload)
- except DecodeError as e:
+ except (DecodeError, ValueError, IndexError) as e:
cause = e
if is_incoming:
retobj = UNKNOWN.In(length, payload)
projects / loctrkd.git / blobdiff