Fix for issue bordaigorl#146

The issue arises due to the reMarkable software version no longer being
accurately reflected in `/etc/version`. This causes rmview to think it
is connecting to an older version.

I've fixed this by switching rmview's SW version logic over to the
semantic versioning scheme used by recent releases. The SW version is
taken from the `REMARKABLE_RELEASE_VERSION` value in
`/usr/share/remarkable/update.conf`, as suggested by @Eeems. Support for
older versions is to be maintained by mapping the older timestamp
version numbers back to the corresponding semantic versions.

src/rmview/connection.py

@@ -2,6 +2,8 @@
 from PyQt5.QtCore import *
 from PyQt5.QtWidgets import *
 
+from .rmparams import timestamp_to_version
+
 
 import paramiko
 import struct
@@ -161,7 +163,20 @@ def _getVersion(self):
 
   def _getSwVersion(self):
     _, out, _ = self.client.exec_command("cat /etc/version")
-    return int(out.read().decode("utf-8"))
+    version_ts = int(out.read().decode("utf-8"))
+    version = timestamp_to_version(version_ts)
+
+    try:
+      _, out, err = self.client.exec_command(r"grep 'REMARKABLE_RELEASE_VERSION=' /usr/share/remarkable/update.conf "
+                                             r"| sed -r 's/(REMARKABLE_RELEASE_VERSION=)([0-9a-zA-Z.]+)/\2/'")
+      config_version = tuple(int(v) for v in out.read().decode("utf-8").strip().split('.'))
+      if (len(config_version) < 4): config_version += (0,)*(len(config_version) - 4);
+      version = config_version
+      log.debug("Using update.conf as SW version authority")
+    except Exception as e:
+      log.debug("Using /etc/version as SW version authority")
+
+    return version
 
 
   @pyqtSlot()
@@ -179,6 +194,7 @@ def run(self):
       self.client.hostname = self.address
       self.client.deviceVersion, self.client.fullDeviceVersion = self._getVersion()
       self.client.softwareVersion = self._getSwVersion()
+      log.info("Detected SW version: {}".format('.'.join(str(v) for v in self.client.softwareVersion)))
       self.signals.onConnect.emit(self.client)
     except Exception as e:
       log.error("Could not connect to %s: %s", self.address, e)

src/rmview/rmparams.py

@@ -9,6 +9,18 @@
   '2.9.1.236': 20210820111232
 }
 
+# This mapping was adapted from the above `SW_VER_TIMESTAMPS` dictionary. 
+# Newer versions do not use timestamp based versioning, and are likewise not represented here.
+def timestamp_to_version(ts):
+  if ts < SW_VER_TIMESTAMPS["2.7"]:
+    return (2, 6, 0, 0)
+  elif ts < SW_VER_TIMESTAMPS["2.9"]:
+    return (2, 7, 0, 0)
+  elif ts < SW_VER_TIMESTAMPS["2.9.1.236"]:
+    return (2, 9, 0, 0)
+  else:
+    return (2, 9, 1, 236)
+
 
 # evtype_sync = 0
 e_type_key = 1

src/rmview/rmview.py

@@ -302,7 +302,7 @@ def connected(self, ssh):
     self.ssh = ssh
     self.viewer.setWindowTitle("rMview - " + ssh.hostname)
 
-    log.info("Detected %s", ssh.fullDeviceVersion)
+    log.info("Detected device: %s", ssh.fullDeviceVersion)
     version = ssh.deviceVersion
     if version not in [1, 2]:
       log.error("Device is unsupported: '%s' [%s]", ssh.fullDeviceVersion, version or "unknown device")
@@ -312,11 +312,11 @@ def connected(self, ssh):
 
     backend = self.config.get('backend', 'auto')
     if backend == 'auto':
-      if ssh.softwareVersion >= SW_VER_TIMESTAMPS['2.9']:
+      if ssh.softwareVersion >= (2, 9, 0, 0):
         backend = 'screenshare'
       else:
         backend = 'vncserver'
-        if ssh.softwareVersion >= SW_VER_TIMESTAMPS['2.7']:
+        if ssh.softwareVersion >= (2, 7, 0, 0):
           log.warning("Detected version 2.7 or 2.8. The server might not work with these versions.")
 
     log.info("Using backend '%s'", backend)

src/rmview/screenstream/screenshare.py

@@ -134,7 +134,7 @@ def startVncClient(self, challenge=None):
   def run(self):
       log.info("Connecting to ScreenShare, make sure you enable it")
       try:
-        if self.ssh.softwareVersion > SW_VER_TIMESTAMPS['2.9.1.236']:
+        if self.ssh.softwareVersion > (2, 9, 1, 236):
           log.warning("Authenticating, please wait...")
           challengeReader = ChallengeReaderProtocol(self.runVnc)
           reactor.listenUDP(5901, challengeReader)