Added Pipe Interface

README.md

@@ -91,14 +91,16 @@ Currently, the following interfaces are supported:
 - Any device with a serial port
 - TCP over IP networks
 - UDP over IP networks
+- External programs via stdio or pipes
+- Custom hardware via stdio or pipes
 
 ## Development Roadmap
 - Version 0.3.6
   - Improving [the manual](https://markqvist.github.io/Reticulum/manual/) with sections specifically for beginners
+- Version 0.3.7
   - Support for radio and modem interfaces on Android
   - GUI interface configuration tool
   - Easy way to share interface configurations, see [#19](https://github.com/markqvist/Reticulum/discussions/19)
-- Version 0.3.7
   - More interface types for even broader compatibility
     - Plain ESP32 devices (ESP-Now, WiFi, Bluetooth, etc.)
     - More LoRa transceivers

RNS/Interfaces/PipeInterface.py

@@ -0,0 +1,187 @@
+# MIT License
+#
+# Copyright (c) 2016-2022 Mark Qvist / unsigned.io
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+from .Interface import Interface
+from time import sleep
+import sys
+import threading
+import time
+import RNS
+
+import subprocess
+import shlex
+
+class HDLC():
+    # The Pipe Interface packetizes data using
+    # simplified HDLC framing, similar to PPP
+    FLAG              = 0x7E
+    ESC               = 0x7D
+    ESC_MASK          = 0x20
+
+    @staticmethod
+    def escape(data):
+        data = data.replace(bytes([HDLC.ESC]), bytes([HDLC.ESC, HDLC.ESC^HDLC.ESC_MASK]))
+        data = data.replace(bytes([HDLC.FLAG]), bytes([HDLC.ESC, HDLC.FLAG^HDLC.ESC_MASK]))
+        return data
+
+class PipeInterface(Interface):
+    MAX_CHUNK = 32768
+    BITRATE_GUESS = 1*1000*1000
+
+    owner    = None
+    command  = None
+    
+    def __init__(self, owner, name, command, respawn_delay):
+        if respawn_delay == None:
+            respawn_delay = 5
+
+        self.rxb = 0
+        self.txb = 0
+        
+        self.owner    = owner
+        self.name     = name
+        self.command  = command
+        self.process  = None
+        self.timeout  = 100
+        self.online   = False
+        self.pipe_is_open = False
+        self.bitrate  = PipeInterface.BITRATE_GUESS
+        self.respawn_delay = respawn_delay
+
+        try:
+            self.open_pipe()
+
+        except Exception as e:
+            RNS.log("Could connect pipe for interface "+str(self), RNS.LOG_ERROR)
+            raise e
+
+        if self.pipe_is_open:
+            self.configure_pipe()
+        else:
+            raise IOError("Could not connect pipe")
+
+
+    def open_pipe(self):
+        RNS.log("Connecting subprocess pipe for "+str(self)+"...", RNS.LOG_VERBOSE)
+        
+        try:
+            self.process = subprocess.Popen(shlex.split(self.command), stdin=subprocess.PIPE, stdout=subprocess.PIPE)
+            self.pipe_is_open = True
+        except Exception as e:
+            raise e
+            self.pipe_is_open = False
+
+
+    def configure_pipe(self):
+        sleep(0.01)
+        thread = threading.Thread(target=self.readLoop)
+        thread.setDaemon(True)
+        thread.start()
+        self.online = True
+        RNS.log("Subprocess pipe for "+str(self)+" is now connected", RNS.LOG_VERBOSE)
+
+
+    def processIncoming(self, data):
+        self.rxb += len(data)            
+        self.owner.inbound(data, self)
+
+
+    def processOutgoing(self,data):
+        if self.online:
+            data = bytes([HDLC.FLAG])+HDLC.escape(data)+bytes([HDLC.FLAG])
+            written = self.process.stdin.write(data)
+            self.process.stdin.flush()
+            self.txb += len(data)            
+            if written != len(data):
+                raise IOError("Pipe interface only wrote "+str(written)+" bytes of "+str(len(data)))
+
+
+    def readLoop(self):
+        try:
+            in_frame = False
+            escape = False
+            data_buffer = b""
+            last_read_ms = int(time.time()*1000)
+
+            while True:
+                process_output = self.process.stdout.read(1)
+                if len(process_output) == 0 and self.process.poll() is not None:
+                    break
+
+                else:
+                    byte = ord(process_output)
+                    last_read_ms = int(time.time()*1000)
+
+                    if (in_frame and byte == HDLC.FLAG):
+                        in_frame = False
+                        self.processIncoming(data_buffer)
+                    elif (byte == HDLC.FLAG):
+                        in_frame = True
+                        data_buffer = b""
+                    elif (in_frame and len(data_buffer) < RNS.Reticulum.MTU):
+                        if (byte == HDLC.ESC):
+                            escape = True
+                        else:
+                            if (escape):
+                                if (byte == HDLC.FLAG ^ HDLC.ESC_MASK):
+                                    byte = HDLC.FLAG
+                                if (byte == HDLC.ESC  ^ HDLC.ESC_MASK):
+                                    byte = HDLC.ESC
+                                escape = False
+                            data_buffer = data_buffer+bytes([byte])
+
+            RNS.log("Subprocess terminated on "+str(self))
+            self.process.kill()
+                    
+        except Exception as e:
+            self.online = False
+            try:
+                self.process.kill()
+            except Exception as e:
+                pass
+
+            RNS.log("A pipe error occurred, the contained exception was: "+str(e), RNS.LOG_ERROR)
+            RNS.log("The interface "+str(self)+" experienced an unrecoverable error and is now offline.", RNS.LOG_ERROR)
+            
+            if RNS.Reticulum.panic_on_interface_error:
+                RNS.panic()
+
+            RNS.log("Reticulum will attempt to reconnect the interface periodically.", RNS.LOG_ERROR)
+
+        self.online = False
+        self.reconnect_pipe()
+
+    def reconnect_pipe(self):
+        while not self.online:
+            try:
+                time.sleep(self.respawn_delay)
+                RNS.log("Attempting to respawn subprocess for "+str(self)+"...", RNS.LOG_VERBOSE)
+                self.open_pipe()
+                if self.pipe_is_open:
+                    self.configure_pipe()
+            except Exception as e:
+                RNS.log("Error while spawning subprocess, the contained exception was: "+str(e), RNS.LOG_ERROR)
+
+        RNS.log("Reconnected pipe for "+str(self))
+
+    def __str__(self):
+        return "PipeInterface["+self.name+"]"

RNS/Interfaces/SerialInterface.py

@@ -117,7 +117,7 @@ class SerialInterface(Interface):
         thread.setDaemon(True)
         thread.start()
         self.online = True
-        RNS.log("Serial port "+self.port+" is now open")
+        RNS.log("Serial port "+self.port+" is now open", RNS.LOG_VERBOSE)
 
 
     def processIncoming(self, data):

RNS/Reticulum.py

@@ -328,7 +328,7 @@ class Reticulum:
         self.__start_local_interface()
 
         if self.is_shared_instance or self.is_standalone_instance:
-            RNS.log("Bringing up system interfaces...", RNS.LOG_DEBUG)
+            RNS.log("Bringing up system interfaces...", RNS.LOG_VERBOSE)
             interface_names = []
             for name in self.config["interfaces"]:
                 if not name in interface_names:
@@ -642,6 +642,35 @@ class Reticulum:
                                 else:
                                     interface.ifac_size = 8
 
+                            if c["type"] == "PipeInterface":
+                                command = c["command"] if "command" in c else None
+                                respawn_delay = c.as_float("respawn_delay") if "respawn_delay" in c else None
+
+                                if command == None:
+                                    raise ValueError("No command specified for PipeInterface")
+
+                                interface = PipeInterface.PipeInterface(
+                                    RNS.Transport,
+                                    name,
+                                    command,
+                                    respawn_delay,
+                                )
+
+                                if "outgoing" in c and c.as_bool("outgoing") == False:
+                                    interface.OUT = False
+                                else:
+                                    interface.OUT = True
+
+                                interface.mode = interface_mode
+
+                                interface.announce_cap = announce_cap
+                                if configured_bitrate:
+                                    interface.bitrate = configured_bitrate
+                                if ifac_size != None:
+                                    interface.ifac_size = ifac_size
+                                else:
+                                    interface.ifac_size = 8
+
                             if c["type"] == "KISSInterface":
                                 preamble = int(c["preamble"]) if "preamble" in c else None
                                 txtail = int(c["txtail"]) if "txtail" in c else None
@@ -827,7 +856,7 @@ class Reticulum:
                     RNS.log("The interface name \""+name+"\" was already used. Check your configuration file for errors!", RNS.LOG_ERROR)
                     RNS.panic()
 
-            RNS.log("System interfaces are ready", RNS.LOG_DEBUG)
+            RNS.log("System interfaces are ready", RNS.LOG_VERBOSE)