add support for creating admin channels

.vscode/launch.json

@@ -13,12 +13,12 @@
       "args": ["--debug", "--ble", "--device", "24:62:AB:DD:DF:3A"]
     },
     {
-      "name": "meshtastic info",
+      "name": "meshtastic admin",
       "type": "python",
       "request": "launch",
       "module": "meshtastic",
       "justMyCode": true,
-      "args": ["--info", "--debug"]
+      "args": ["--debug", "--setch-longslow", "--port", "/dev/ttyUSB1"]
     },
     {
       "name": "meshtastic tunnel",

meshtastic/__init__.py

@@ -180,6 +180,28 @@ class Node:
         self._sendAdmin(p)
         logging.debug("Wrote channel {channelIndex}")
 
+    def getChannelByName(self, name):
+        """Try to find the named channel or return None"""
+        for c in (self.channels or []):
+            if c.settings and c.settings.name == name:
+                return c
+        return None
+
+    def getDisabledChannel(self):
+        """Return the first channel that is disabled (i.e. available for some new use)"""
+        for c in self.channels:
+            if c.role == channel_pb2.Channel.Role.DISABLED:
+                return c
+        return None
+
+    def _getAdminChannelIndex(self):
+        """Return the channel number of the admin channel, or 0 if no reserved channel"""
+        c = self.getChannelByName("admin")
+        if c:
+            return c.index
+        else:
+            return 0
+
     def setOwner(self, long_name, short_name=None):
         """Set device owner name"""
         nChars = 3
@@ -295,6 +317,16 @@ class Node:
 
             if quitEarly or index >= self.iface.myInfo.max_channels - 1:
                 logging.debug("Finished downloading channels")
+
+                # Fill the rest of array with DISABLED channels
+                index += 1
+                while index < self.iface.myInfo.max_channels:
+                    ch = channel_pb2.Channel()
+                    ch.role = channel_pb2.Channel.Role.DISABLED
+                    ch.index = index
+                    self.partialChannels.append(ch)
+                    index += 1
+
                 self.channels = self.partialChannels
                 # FIXME, the following should only be called after we have settings and channels
                 self.iface._connected()  # Tell everone else we are ready to go
@@ -313,7 +345,8 @@ class Node:
                                    portNum=portnums_pb2.PortNum.ADMIN_APP,
                                    wantAck=True,
                                    wantResponse=wantResponse,
-                                   onResponse=onResponse)
+                                   onResponse=onResponse,
+                                   channelIndex=self.iface.localNode._getAdminChannelIndex())
 
 
 class MeshInterface:
@@ -404,7 +437,8 @@ class MeshInterface:
                  portNum=portnums_pb2.PortNum.PRIVATE_APP, wantAck=False,
                  wantResponse=False,
                  hopLimit=defaultHopLimit,
-                 onResponse=None):
+                 onResponse=None,
+                 channelIndex=0):
         """Send a data packet to some other node
 
         Keyword Arguments:
@@ -428,6 +462,7 @@ class MeshInterface:
             raise Exception("A non-zero port number must be specified")
 
         meshPacket = mesh_pb2.MeshPacket()
+        meshPacket.channel = channelIndex
         meshPacket.decoded.payload = data
         meshPacket.decoded.portnum = portNum
         meshPacket.decoded.want_response = wantResponse

meshtastic/__main__.py

@@ -2,10 +2,7 @@
 
 import argparse
 import platform
-import logging
-import sys
-import codecs
-import base64
+import logging, sys, codecs, base64, os
 from . import SerialInterface, TCPInterface, BLEInterface, test, remote_hardware
 from pubsub import pub
 from . import mesh_pb2, portnums_pb2, channel_pb2
@@ -64,6 +61,19 @@ def onConnection(interface, topic=pub.AUTO_TOPIC):
 trueTerms = {"t", "true", "yes"}
 falseTerms = {"f", "false", "no"}
 
+def genPSKS256():
+    return os.urandom(32)
+
+def fromPSK(valstr):
+    """A special version of fromStr that assumes the user is trying to set a PSK.  
+    In that case we also allow "none" or "random" (to have python generate one)
+    """
+    if valstr == "random":
+        return genPSK256()
+    elif valstr == "none":
+        return bytes()
+    else:
+        return fromStr(valstr)
 
 def fromStr(valstr):
     """try to parse as int, float or bool (and fallback to a string as last resort)
@@ -269,35 +279,71 @@ def onConnected(interface):
             getNode().setURL(args.seturl)
 
         # handle changing channels
+
+        if args.ch_enable_admin:
+            closeNow = True
+            n = getNode()
+            ch = n.getChannelByName("admin")
+            if ch:
+                logging.error("This node already is configured for remote admin access - no changes.")
+            else:
+                ch = n.getDisabledChannel()
+                if not ch:
+                    raise Exception("No free channels were found")
+                chs = channel_pb2.ChannelSettings()
+                chs.psk = genPSKS256()
+                chs.name = "admin"
+                ch.settings.CopyFrom(chs)
+                ch.role = channel_pb2.Channel.Role.SECONDARY 
+                print(f"Writing modified channels to device")
+                n.writeChannel(ch.index)
+
         if args.setchan or args.setch_longslow or args.setch_shortfast:
             closeNow = True
 
             ch = getNode().channels[channelIndex]
 
-            def setSimpleChannel(modem_config):
-                """Set one of the simple modem_config only based channels"""
+            enable = args.ch_enable # should we enable this channel?
 
-                # Completely new channel settings
-                chs = channel_pb2.ChannelSettings()
-                chs.modem_config = modem_config
-                chs.psk = bytes([1])  # Use default channel psk 1
+            if args.setch_longslow or args.setch_shortfast:
+                if channelIndex != 0:
+                    raise Exception("standard channel settings can only be applied to the PRIMARY channel")
 
-                ch.settings.CopyFrom(chs)
+                enable = True # force enable
 
-            # handle the simple channel set commands
-            if args.setch_longslow:
-                setSimpleChannel(
-                    channel_pb2.ChannelSettings.ModemConfig.Bw125Cr48Sf4096)
+                def setSimpleChannel(modem_config):
+                    """Set one of the simple modem_config only based channels"""
 
-            if args.setch_shortfast:
-                setSimpleChannel(
-                    channel_pb2.ChannelSettings.ModemConfig.Bw500Cr45Sf128)
+                    # Completely new channel settings
+                    chs = channel_pb2.ChannelSettings()
+                    chs.modem_config = modem_config
+                    chs.psk = bytes([1])  # Use default channel psk 1
+
+                    ch.settings.CopyFrom(chs)
+
+                # handle the simple channel set commands
+                if args.setch_longslow:
+                    setSimpleChannel(
+                        channel_pb2.ChannelSettings.ModemConfig.Bw125Cr48Sf4096)
+
+                if args.setch_shortfast:
+                    setSimpleChannel(
+                        channel_pb2.ChannelSettings.ModemConfig.Bw500Cr45Sf128)
 
             # Handle the channel settings
             for pref in (args.setchan or []):
-                setPref(ch.settings, pref[0], pref[1])
+                if pref[0] == "psk":
+                    setattr(ch.settings, pref[0], fromPSK(pref[1]))
+                else:
+                    setPref(ch.settings, pref[0], pref[1])
+                enable = True # If we set any pref, assume the user wants to enable the channel
 
-            print("Writing modified channels to device")
+            if enable:
+                ch.role = channel_pb2.Channel.Role.PRIMARY if (channelIndex == 0) else channel_pb2.Channel.Role.SECONDARY 
+            else:
+                ch.role = channel_pb2.Channel.Role.DISABLED
+
+            print(f"Writing modified channels to device")
             getNode().writeChannel(channelIndex)
 
         if args.info:
@@ -354,6 +400,10 @@ def common():
         parser.print_help(sys.stderr)
         sys.exit(1)
     else:
+        if args.ch_index is not None:
+            global channelIndex
+            channelIndex = int(args.ch_index)
+
         # Some commands require dest to be set, so we now use destOrAll/destOrLocal for more lenient commands
         if not args.dest:
             args.destOrAll = "^all"
@@ -366,7 +416,7 @@ def common():
             if args.info or args.nodes or args.set or args.seturl or args.setowner or args.setlat or args.setlon or \
                     args.settime or \
                     args.setch_longslow or args.setch_shortfast or args.setchan or args.sendtext or \
-                    args.qr:
+                    args.qr or args.ch_enable_admin:
                 args.seriallog = "none"  # assume no debug output in this case
             else:
                 args.seriallog = "stdout"  # default to stdout
@@ -443,6 +493,18 @@ def initParser():
     parser.add_argument(
         "--seturl", help="Set a channel URL", action="store")
 
+    parser.add_argument(
+        "--ch-index", help="Set the specified channel index", action="store")
+
+    parser.add_argument(
+        "--ch-enable", help="Enable the specified channel", action="store_true", dest="ch_enable")
+
+    parser.add_argument(
+        "--ch-disable", help="Disable the specified channel", action="store_false", dest="ch_enable")
+
+    parser.add_argument(
+        "--ch-enable-admin", help="Assign a PSK to the admin channel, to allow remote adminstration", action="store_true")
+
     parser.add_argument(
         "--setowner", help="Set device owner name", action="store")