Add initial support for the AnkerMake M5C

This change allows to monitor MQTT messages of the AnkerMake M5C on the
command line as well as observe the printer status via the Web GUI.
It is also possible to send print jobs from your slicer to the printer
without using AnkerMake Slicer or Studio (see README.md).
The M5's additional hardware is still expected to exist, therefore the
Web GUI will still pretend to wait for a camera connection, for example.
This will have to be fixed in the future.

libflagship/mqtt.py

@@ -103,9 +103,19 @@ def parse(cls, p):
  m7, p = u8.parse(p)
  packet_type, p = MqttPktType.parse(p)
  packet_num, p = u16le.parse(p)
- time, p = u32le.parse(p)
- device_guid, p = String.parse(p, 37)
- padding, p = Bytes.parse(p, 11)
+ if m5 == 2:
+ # AnkerMake M5
+ time, p = u32le.parse(p)
+ device_guid, p = String.parse(p, 37)
+ padding, p = Bytes.parse(p, 11)
+ elif m5 == 1:
+ # AnkerMake M5C
+ time = 0 # does not seem to be sent for M5C
+ device_guid = "none" # still present for M5C???
+ padding, p = Bytes.parse(p, 12) # first 6 bytes seem to change with each packet, rest is all zeros
+ else:
+ raise ValueError(f"Unsupported mqtt message format (expected 1 or 2, but found {m5})")
+
  data, p = Tail.parse(p)
  return cls(signature=signature, size=size, m3=m3, m4=m4, m5=m5, m6=m6, m7=m7, packet_type=packet_type, packet_num=packet_num, time=time, device_guid=device_guid, padding=padding, data=data), p
 
@@ -119,9 +129,12 @@ def pack(self):
  p += u8.pack(self.m7)
  p += MqttPktType.pack(self.packet_type)
  p += u16le.pack(self.packet_num)
- p += u32le.pack(self.time)
- p += String.pack(self.device_guid, 37)
- p += Bytes.pack(self.padding, 11)
+ if self.m5 == 2:
+ p += u32le.pack(self.time)
+ p += String.pack(self.device_guid, 37)
+ p += Bytes.pack(self.padding, 11)
+ elif self.m5 == 1:
+ p += Bytes.pack(self.padding, 12)
  p += Tail.pack(self.data)
  return p
 
@@ -131,17 +144,23 @@ class MqttMsg(_MqttMsg):
  @classmethod
  def parse(cls, p, key):
  p = mqtt_checksum_remove(p)
- if p[6] != 2:
- raise ValueError(f"Unsupported mqtt message format (expected 2, but found {p[6]})")
- body, data = p[:64], mqtt_aes_decrypt(p[64:], key)
+ try:
+ body_len = {1:24, 2:64}[p[6]]
+ except KeyError:
+ raise ValueError(f"Unsupported mqtt message format (expected 1 or 2, but found {p[6]})")
+ body, data = p[:body_len], mqtt_aes_decrypt(p[body_len:], key)
  res = super().parse(body + data)
  assert res[0].size == (len(p) + 1)
  return res
 
  def pack(self, key):
  data = mqtt_aes_encrypt(self.data, key)
- self.size = 64 + len(data) + 1
- body = super().pack()[:64]
+ try:
+ body_len = {1:24, 2:64}[self.m5]
+ except KeyError:
+ raise ValueError(f"Unsupported mqtt message format (expected 1 or 2, but found {self.m5})")
+ self.size = body_len + len(data) + 1
+ body = super().pack()[:body_len]
  final = mqtt_checksum_add(body + data)
  return final