Files
intercept/routes/pager.py
James Smith 1398a5dedd Major security and code quality improvements
Security:
- Add input validation for all API endpoints (frequency, lat/lon, device, gain, ppm)
- Add HTML escaping utility to prevent XSS attacks
- Add path traversal protection for log file configuration
- Add proper HTTP status codes for error responses (400, 409, 503)

Performance:
- Reduce SSE keepalive overhead (30s interval instead of 1s)
- Add centralized SSE stream utility with optimized keepalive
- Add DataStore class for thread-safe data with automatic cleanup

New Features:
- Add data export endpoints (/export/aircraft, /export/wifi, /export/bluetooth)
- Support for both JSON and CSV export formats
- Add process cleanup on application exit (atexit handlers)
- Label Iridium module as demo mode with clear warnings

Code Quality:
- Create utils/validation.py for centralized input validation
- Create utils/sse.py for SSE stream utilities
- Create utils/cleanup.py for memory management
- Add safe_terminate() and register_process() for process management
- Improve error handling with proper logging throughout routes

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2025-12-30 19:24:40 +00:00

384 lines
14 KiB
Python

"""Pager decoding routes (POCSAG/FLEX)."""
from __future__ import annotations
import os
import pathlib
import re
import pty
import queue
import select
import subprocess
import threading
import time
from datetime import datetime
from typing import Any, Generator
from flask import Blueprint, jsonify, request, Response
import app as app_module
from utils.logging import pager_logger as logger
from utils.validation import validate_frequency, validate_device_index, validate_gain, validate_ppm
from utils.sse import format_sse
from utils.process import safe_terminate, register_process
pager_bp = Blueprint('pager', __name__)
def parse_multimon_output(line: str) -> dict[str, str] | None:
"""Parse multimon-ng output line."""
line = line.strip()
# POCSAG parsing - with message content
pocsag_match = re.match(
r'(POCSAG\d+):\s*Address:\s*(\d+)\s+Function:\s*(\d+)\s+(Alpha|Numeric):\s*(.*)',
line
)
if pocsag_match:
return {
'protocol': pocsag_match.group(1),
'address': pocsag_match.group(2),
'function': pocsag_match.group(3),
'msg_type': pocsag_match.group(4),
'message': pocsag_match.group(5).strip() or '[No Message]'
}
# POCSAG parsing - address only (no message content)
pocsag_addr_match = re.match(
r'(POCSAG\d+):\s*Address:\s*(\d+)\s+Function:\s*(\d+)\s*$',
line
)
if pocsag_addr_match:
return {
'protocol': pocsag_addr_match.group(1),
'address': pocsag_addr_match.group(2),
'function': pocsag_addr_match.group(3),
'msg_type': 'Tone',
'message': '[Tone Only]'
}
# FLEX parsing (standard format)
flex_match = re.match(
r'FLEX[:\|]\s*[\d\-]+[\s\|]+[\d:]+[\s\|]+([\d/A-Z]+)[\s\|]+([\d.]+)[\s\|]+\[?(\d+)\]?[\s\|]+(\w+)[\s\|]+(.*)',
line
)
if flex_match:
return {
'protocol': 'FLEX',
'address': flex_match.group(3),
'function': flex_match.group(1),
'msg_type': flex_match.group(4),
'message': flex_match.group(5).strip() or '[No Message]'
}
# Simple FLEX format
flex_simple = re.match(r'FLEX:\s*(.+)', line)
if flex_simple:
return {
'protocol': 'FLEX',
'address': 'Unknown',
'function': '',
'msg_type': 'Unknown',
'message': flex_simple.group(1).strip()
}
return None
def log_message(msg: dict[str, Any]) -> None:
"""Log a message to file if logging is enabled."""
if not app_module.logging_enabled:
return
try:
with open(app_module.log_file_path, 'a') as f:
timestamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
f.write(f"{timestamp} | {msg.get('protocol', 'UNKNOWN')} | {msg.get('address', '')} | {msg.get('message', '')}\n")
except Exception as e:
logger.error(f"Failed to log message: {e}")
def stream_decoder(master_fd: int, process: subprocess.Popen[bytes]) -> None:
"""Stream decoder output to queue using PTY for unbuffered output."""
try:
app_module.output_queue.put({'type': 'status', 'text': 'started'})
buffer = ""
while True:
try:
ready, _, _ = select.select([master_fd], [], [], 1.0)
except Exception:
break
if ready:
try:
data = os.read(master_fd, 1024)
if not data:
break
buffer += data.decode('utf-8', errors='replace')
while '\n' in buffer:
line, buffer = buffer.split('\n', 1)
line = line.strip()
if not line:
continue
parsed = parse_multimon_output(line)
if parsed:
parsed['timestamp'] = datetime.now().strftime('%H:%M:%S')
app_module.output_queue.put({'type': 'message', **parsed})
log_message(parsed)
else:
app_module.output_queue.put({'type': 'raw', 'text': line})
except OSError:
break
if process.poll() is not None:
break
except Exception as e:
app_module.output_queue.put({'type': 'error', 'text': str(e)})
finally:
try:
os.close(master_fd)
except OSError:
pass
process.wait()
app_module.output_queue.put({'type': 'status', 'text': 'stopped'})
with app_module.process_lock:
app_module.current_process = None
@pager_bp.route('/start', methods=['POST'])
def start_decoding() -> Response:
with app_module.process_lock:
if app_module.current_process:
return jsonify({'status': 'error', 'message': 'Already running'}), 409
data = request.json or {}
# Validate inputs
try:
freq = validate_frequency(data.get('frequency', '929.6125'))
gain = validate_gain(data.get('gain', '0'))
ppm = validate_ppm(data.get('ppm', '0'))
device = validate_device_index(data.get('device', '0'))
except ValueError as e:
return jsonify({'status': 'error', 'message': str(e)}), 400
squelch = data.get('squelch', '0')
try:
squelch = int(squelch)
if not 0 <= squelch <= 1000:
raise ValueError("Squelch must be between 0 and 1000")
except (ValueError, TypeError):
return jsonify({'status': 'error', 'message': 'Invalid squelch value'}), 400
# Validate protocols
valid_protocols = ['POCSAG512', 'POCSAG1200', 'POCSAG2400', 'FLEX']
protocols = data.get('protocols', valid_protocols)
if not isinstance(protocols, list):
return jsonify({'status': 'error', 'message': 'Protocols must be a list'}), 400
protocols = [p for p in protocols if p in valid_protocols]
if not protocols:
protocols = valid_protocols
# Clear queue
while not app_module.output_queue.empty():
try:
app_module.output_queue.get_nowait()
except queue.Empty:
break
# Build multimon-ng decoder arguments
decoders = []
for proto in protocols:
if proto == 'POCSAG512':
decoders.extend(['-a', 'POCSAG512'])
elif proto == 'POCSAG1200':
decoders.extend(['-a', 'POCSAG1200'])
elif proto == 'POCSAG2400':
decoders.extend(['-a', 'POCSAG2400'])
elif proto == 'FLEX':
decoders.extend(['-a', 'FLEX'])
# Build rtl_fm command
rtl_cmd = [
'rtl_fm',
'-d', str(device),
'-f', f'{freq}M',
'-M', 'fm',
'-s', '22050',
]
if gain and gain != '0':
rtl_cmd.extend(['-g', str(gain)])
if ppm and ppm != '0':
rtl_cmd.extend(['-p', str(ppm)])
if squelch and squelch != '0':
rtl_cmd.extend(['-l', str(squelch)])
rtl_cmd.append('-')
multimon_cmd = ['multimon-ng', '-t', 'raw'] + decoders + ['-f', 'alpha', '-']
full_cmd = ' '.join(rtl_cmd) + ' | ' + ' '.join(multimon_cmd)
logger.info(f"Running: {full_cmd}")
try:
# Create pipe: rtl_fm | multimon-ng
rtl_process = subprocess.Popen(
rtl_cmd,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE
)
# Start a thread to monitor rtl_fm stderr for errors
def monitor_rtl_stderr():
for line in rtl_process.stderr:
err_text = line.decode('utf-8', errors='replace').strip()
if err_text:
logger.debug(f"[RTL_FM] {err_text}")
app_module.output_queue.put({'type': 'raw', 'text': f'[rtl_fm] {err_text}'})
rtl_stderr_thread = threading.Thread(target=monitor_rtl_stderr)
rtl_stderr_thread.daemon = True
rtl_stderr_thread.start()
# Create a pseudo-terminal for multimon-ng output
master_fd, slave_fd = pty.openpty()
multimon_process = subprocess.Popen(
multimon_cmd,
stdin=rtl_process.stdout,
stdout=slave_fd,
stderr=slave_fd,
close_fds=True
)
os.close(slave_fd)
rtl_process.stdout.close()
app_module.current_process = multimon_process
app_module.current_process._rtl_process = rtl_process
app_module.current_process._master_fd = master_fd
# Start output thread with PTY master fd
thread = threading.Thread(target=stream_decoder, args=(master_fd, multimon_process))
thread.daemon = True
thread.start()
app_module.output_queue.put({'type': 'info', 'text': f'Command: {full_cmd}'})
return jsonify({'status': 'started', 'command': full_cmd})
except FileNotFoundError as e:
return jsonify({'status': 'error', 'message': f'Tool not found: {e.filename}'})
except Exception as e:
return jsonify({'status': 'error', 'message': str(e)})
@pager_bp.route('/stop', methods=['POST'])
def stop_decoding() -> Response:
with app_module.process_lock:
if app_module.current_process:
# Kill rtl_fm process first
if hasattr(app_module.current_process, '_rtl_process'):
try:
app_module.current_process._rtl_process.terminate()
app_module.current_process._rtl_process.wait(timeout=2)
except (subprocess.TimeoutExpired, OSError):
try:
app_module.current_process._rtl_process.kill()
except OSError:
pass
# Close PTY master fd
if hasattr(app_module.current_process, '_master_fd'):
try:
os.close(app_module.current_process._master_fd)
except OSError:
pass
# Kill multimon-ng
app_module.current_process.terminate()
try:
app_module.current_process.wait(timeout=2)
except subprocess.TimeoutExpired:
app_module.current_process.kill()
app_module.current_process = None
return jsonify({'status': 'stopped'})
return jsonify({'status': 'not_running'})
@pager_bp.route('/status')
def get_status() -> Response:
"""Check if decoder is currently running."""
with app_module.process_lock:
if app_module.current_process and app_module.current_process.poll() is None:
return jsonify({'running': True, 'logging': app_module.logging_enabled, 'log_file': app_module.log_file_path})
return jsonify({'running': False, 'logging': app_module.logging_enabled, 'log_file': app_module.log_file_path})
@pager_bp.route('/logging', methods=['POST'])
def toggle_logging() -> Response:
"""Toggle message logging."""
data = request.json or {}
if 'enabled' in data:
app_module.logging_enabled = bool(data['enabled'])
if 'log_file' in data and data['log_file']:
# Validate path to prevent directory traversal
try:
requested_path = pathlib.Path(data['log_file']).resolve()
# Only allow files in the current directory or logs subdirectory
cwd = pathlib.Path('.').resolve()
logs_dir = (cwd / 'logs').resolve()
# Check if path is within allowed directories
is_in_cwd = str(requested_path).startswith(str(cwd))
is_in_logs = str(requested_path).startswith(str(logs_dir))
if not (is_in_cwd or is_in_logs):
return jsonify({'status': 'error', 'message': 'Invalid log file path'}), 400
# Ensure it's not a directory
if requested_path.is_dir():
return jsonify({'status': 'error', 'message': 'Log file path must be a file, not a directory'}), 400
app_module.log_file_path = str(requested_path)
except (ValueError, OSError) as e:
logger.warning(f"Invalid log file path: {e}")
return jsonify({'status': 'error', 'message': 'Invalid log file path'}), 400
return jsonify({'logging': app_module.logging_enabled, 'log_file': app_module.log_file_path})
@pager_bp.route('/stream')
def stream() -> Response:
import json
def generate() -> Generator[str, None, None]:
last_keepalive = time.time()
keepalive_interval = 30.0 # Send keepalive every 30 seconds instead of 1 second
while True:
try:
msg = app_module.output_queue.get(timeout=1)
last_keepalive = time.time()
yield format_sse(msg)
except queue.Empty:
now = time.time()
if now - last_keepalive >= keepalive_interval:
yield format_sse({'type': 'keepalive'})
last_keepalive = now
response = Response(generate(), mimetype='text/event-stream')
response.headers['Cache-Control'] = 'no-cache'
response.headers['X-Accel-Buffering'] = 'no'
response.headers['Connection'] = 'keep-alive'
return response