Working with UDP on localhost

.gitignore

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+# Python artifacts
+__pycache__/
+*.pyc
+*.pyo
+*.pyd
+
+# Virtual environment
+.venv/
+env/
+venv/
+
+# OS junk
+.DS_Store
+Thumbs.db
+
+# Testing and coverage
+.coverage
+pytest_cache/
+htmlcov/
+
+# IDE/editor stuff
+.vscode/
+.idea/
+*.swp
+
+# Logs (if you decide to generate any)
+*.log
+logs/
+
+# Radio mock dumps (if you log traffic to files later)
+*.cap
+*.pcap

base_station/server.py

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+import socket
+import time
+import threading
+
+BROADCAST_IP = "127.0.0.1"
+PORT = 4444
+
+BEACON_INTERVAL = 10  # seconds
+BASE_CALLSIGN = "KI5QKX-10"
+NETWORK_NAME = "HAMNET-HOUSTON"
+
+# Fake IP pool
+IP_POOL = [
+    "44.127.254.12",
+    "44.127.254.13",
+    "44.127.254.14",
+    "44.127.254.15"
+]
+LEASE_TIME = 3600  # seconds
+NETMASK = "24"
+GATEWAY = "44.127.254.1"
+DNS_SERVER = "44.127.254.1"
+
+active_leases = {}
+
+def build_beacon():
+    return f"0.1|CRAP_BEACON|{BASE_CALLSIGN}|{NETWORK_NAME}"
+
+def build_accept(client_callsign, ip_address):
+    return f"0.1|CRAP_ACCEPT|{client_callsign}|{NETWORK_NAME}|{ip_address}/{NETMASK}|{GATEWAY}|{DNS_SERVER}|{LEASE_TIME}"
+
+def handle_request(data, addr, sock):
+    parts = data.split('|')
+
+    if parts[1] == "CRAP_BEACON":
+        return
+
+    if len(parts) < 4:
+        print(f"Received malformed message from {addr}: {data}")
+        return
+    if parts[1] != "CRAP_REQUEST":
+        print(f"Ignoring non-request message: {data}")
+        return
+    
+    client_callsign = parts[2]
+    network_requested = parts[3]
+
+    if network_requested != NETWORK_NAME:
+        print(f"Client {client_callsign} requested wrong network ({network_requested}). Ignored.")
+        return
+
+    print(f"Received join request from {client_callsign} ({addr}).")
+
+    # Assign IP
+    if client_callsign in active_leases:
+        assigned_ip = active_leases[client_callsign]
+        print(f"Client {client_callsign} already has IP {assigned_ip}.")
+    elif IP_POOL:
+        assigned_ip = IP_POOL.pop(0)
+        active_leases[client_callsign] = assigned_ip
+        print(f"Assigned IP {assigned_ip} to {client_callsign}.")
+    else:
+        print(f"No available IPs for {client_callsign}!")
+        return
+
+    # Send ACCEPT
+    accept_message = build_accept(client_callsign, assigned_ip)
+    sock.sendto(accept_message.encode('utf-8'), addr)
+    print(f"Sent CRAP_ACCEPT to {client_callsign}.")
+
+def beacon_loop(sock):
+    while True:
+        beacon = build_beacon().encode('utf-8')
+        sock.sendto(beacon, (BROADCAST_IP, PORT))
+        print(f"Sent beacon: {beacon.decode('utf-8')}")
+        time.sleep(BEACON_INTERVAL)
+
+def main():
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    # sock.bind((BROADCAST_IP, PORT))
+    
+    print(f"Base Station {BASE_CALLSIGN} starting up on {NETWORK_NAME}...")
+
+    # Start beaconing in a separate thread
+    threading.Thread(target=beacon_loop, args=(sock,), daemon=True).start()
+
+    while True:
+        data, addr = sock.recvfrom(1024)
+        decoded = data.decode('utf-8')
+        handle_request(decoded, addr, sock)
+
+if __name__ == "__main__":
+    main()

client_node/client.py

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+import socket
+import time
+
+LISTEN_IP = "0.0.0.0"
+PORT = 4444
+
+CLIENT_CALLSIGN = "N0CALL-7"
+
+configured = False
+lease_expiration = None
+
+def parse_message(data):
+    parts = data.split('|')
+    return parts
+
+def build_request(network_name):
+    return f"0.1|CRAP_REQUEST|{CLIENT_CALLSIGN}|{network_name}"
+
+def apply_network_config(assigned_ip, gateway, dns, lease_time):
+    global configured, lease_expiration
+    print("\n[Network Configuration]")
+    print(f" Bringing up interface: ax0")
+    print(f" Assigned IP address: {assigned_ip}")
+    print(f" Default Gateway: {gateway}")
+    print(f" DNS Server: {dns}")
+    print(f" Lease Time: {lease_time} seconds")
+    print(" Interface ax0 configured successfully! 🚀")
+    print("----------------------------------------")
+
+    configured = True
+    lease_expiration = time.time() + int(lease_time)
+
+def main():
+    global configured, lease_expiration
+
+    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    sock.bind((LISTEN_IP, PORT))
+    
+    print(f"Client {CLIENT_CALLSIGN} listening for CRAPRNIAC beacons...")
+
+    while True:
+        # Check lease expiration
+        if configured and lease_expiration and time.time() >= lease_expiration:
+            print("\n[Lease Expired]")
+            print(" Tearing down interface ax0...")
+            print(" Ready to rejoin network.")
+            print("----------------------------------------")
+            configured = False
+            lease_expiration = None
+
+        data, addr = sock.recvfrom(1024)
+        decoded = data.decode('utf-8')
+        parts = parse_message(decoded)
+
+        if len(parts) < 2:
+            continue
+        
+        if parts[1] == "CRAP_BEACON":
+            if not configured:
+                base_callsign = parts[2]
+                network_name = parts[3]
+                print(f"\nHeard beacon from {base_callsign} ({addr}):")
+                print(f"  Network: {network_name}")
+                print("Sending join request...")
+                request = build_request(network_name).encode('utf-8')
+                sock.sendto(request, addr)
+        
+        elif parts[1] == "CRAP_ACCEPT":
+            client_callsign = parts[2]
+            network_name = parts[3]
+            assigned_ip = parts[4]
+            gateway = parts[5]
+            dns = parts[6]
+            lease_time = parts[7]
+            print(f"\nReceived CRAP_ACCEPT:")
+            print(f"  Assigned IP: {assigned_ip}")
+            print(f"  Gateway: {gateway}")
+            print(f"  DNS Server: {dns}")
+            print(f"  Lease Time: {lease_time} seconds")
+
+            apply_network_config(assigned_ip, gateway, dns, lease_time)
+
+if __name__ == "__main__":
+    main()

pyproject.toml

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+[build-system]
+requires = ["setuptools>=61.0"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "craprniac"
+version = "0.1.0"
+description = "Completely Ridiculous Amateur Protocol for Radio Node IP Auto-Configuration"
+authors = [
+  { name="John Burwell", email="your.email@example.com" }
+]
+license = { text = "MIT" }
+readme = "README.md"
+requires-python = ">=3.10"
+dependencies = [
+    # put runtime dependencies here if needed later
+]
+
+[project.optional-dependencies]
+dev = [
+    "pytest",
+]
+
+[tool.pytest.ini_options]
+minversion = "6.0"
+addopts = "-ra -q"
+testpaths = [
+    "tests",
+]