From 425f0153d09a2b15e62037b9d6ce0d8fa98fe48b Mon Sep 17 00:00:00 2001
From: Mark Qvist <mark@unsigned.io>
Date: Fri, 3 Sep 2021 10:56:49 +0200
Subject: [PATCH] Added flow control timeouts to AX.25 interface and optimised
 timeouts.

---
 RNS/Interfaces/AX25KISSInterface.py | 17 ++++++++++-------
 RNS/Interfaces/KISSInterface.py     |  6 +++---
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/RNS/Interfaces/AX25KISSInterface.py b/RNS/Interfaces/AX25KISSInterface.py
index 2566eea..addd285 100644
--- a/RNS/Interfaces/AX25KISSInterface.py
+++ b/RNS/Interfaces/AX25KISSInterface.py
@@ -62,13 +62,12 @@ class AX25KISSInterface(Interface):
         self.stopbits = stopbits
         self.timeout  = 100
         self.online   = False
-        # TODO: Sane default and make this configurable
-        # TODO: Changed to 25ms instead of 100ms, check it
-        self.txdelay  = 0.025
 
         self.packet_queue    = []
         self.flow_control    = flow_control
         self.interface_ready = False
+        self.flow_control_timeout = 5
+        self.flow_control_locked  = time.time()
 
         if (len(self.src_call) < 3 or len(self.src_call) > 6):
             raise ValueError("Invalid callsign for "+str(self))
@@ -197,6 +196,7 @@ class AX25KISSInterface(Interface):
             if self.interface_ready:
                 if self.flow_control:
                     self.interface_ready = False
+                    self.flow_control_locked = time.time()
 
                 encoded_dst_ssid = bytes([0x60 | (self.dst_ssid << 1)])
                 encoded_src_ssid = bytes([0x60 | (self.src_ssid << 1) | 0x01])
@@ -223,9 +223,6 @@ class AX25KISSInterface(Interface):
                 data = data.replace(bytes([0xc0]), bytes([0xdb])+bytes([0xdc]))
                 kiss_frame = bytes([KISS.FEND])+bytes([0x00])+data+bytes([KISS.FEND])
 
-                if (self.txdelay > 0):
-                    sleep(self.txdelay)
-
                 written = self.serial.write(kiss_frame)
                 if written != len(kiss_frame):
                     if self.flow_control:
@@ -293,7 +290,13 @@ class AX25KISSInterface(Interface):
                         in_frame = False
                         command = KISS.CMD_UNKNOWN
                         escape = False
-                    sleep(0.08)
+                    sleep(0.05)
+
+                    if self.flow_control:
+                        if not self.interface_ready:
+                            if time.time() > self.flow_control_locked + self.flow_control_timeout:
+                                RNS.log("Interface "+str(self)+" is unlocking flow control due to time-out. This should not happen. Your hardware might have missed a flow-control READY command, or maybe it does not support flow-control.", RNS.LOG_WARNING)
+                                self.process_queue()
 
         except Exception as e:
             self.online = False
diff --git a/RNS/Interfaces/KISSInterface.py b/RNS/Interfaces/KISSInterface.py
index eb414d9..a4c508c 100644
--- a/RNS/Interfaces/KISSInterface.py
+++ b/RNS/Interfaces/KISSInterface.py
@@ -60,7 +60,7 @@ class KISSInterface(Interface):
         self.packet_queue    = []
         self.flow_control    = flow_control
         self.interface_ready = False
-        self.flow_control_timeout = 10
+        self.flow_control_timeout = 5
         self.flow_control_locked  = time.time()
 
         self.preamble    = preamble if preamble != None else 350;
@@ -259,12 +259,12 @@ class KISSInterface(Interface):
                         in_frame = False
                         command = KISS.CMD_UNKNOWN
                         escape = False
-                    sleep(0.08)
+                    sleep(0.05)
 
                     if self.flow_control:
                         if not self.interface_ready:
                             if time.time() > self.flow_control_locked + self.flow_control_timeout:
-                                RNS.log("Interface "+str(self)+" is unlocking flow control due to time-out. This should not happen. Your hardware might have missed a flow-control READY command.", RNS.LOG_WARNING)
+                                RNS.log("Interface "+str(self)+" is unlocking flow control due to time-out. This should not happen. Your hardware might have missed a flow-control READY command, or maybe it does not support flow-control.", RNS.LOG_WARNING)
                                 self.process_queue()
 
                     if self.beacon_i != None and self.beacon_d != None: