ethermess/ethermess.py

#!/usr/bin/env python3
libexec_dir = __LIBEXECDIR__

import select
import subprocess
import sys

def writeall(f, b):
	written = 0
	while written < len(b):
		written += f.write(b[written:])

def readall(f, length):
	read = bytearray()
	while len(read) < length:
		data = f.read(length - len(read))
		if data == b'':
			raise ConnectionError('Could not satisfy read of %i bytes' % length)
		read.extend(data)
	return bytes(read)

def parse_mac(text):
	parts = text.split(':')
	if len(parts) != 6:
		raise ValueError('Invalid MAC format: %s' % text)

	try:
		parsed = bytes(int(field, 16) for field in parts)
	except ValueError:
		raise ValueError('Invalid MAC format %s' % text)

	return parsed

def format_mac(mac):
	return ':'.join(mac[i:i+1].hex() for i in range(len(mac)))

def format_status(status):
	if status == 0:
		return 'available'
	elif status == 1:
		return 'unavailable'
	elif status == 2:
		return 'offline'
	else:
		raise ValueError('Unknown status %i' % status)

def handle_user_command(backend, command):
	if command == 's':
		mac = parse_mac(input('mac> '))
		writeall(backend, b's' + mac)

	elif command == 'i':
		mac = parse_mac(input('mac> '))
		writeall(backend, b'i' + mac)

	elif command == 'm':
		mac = parse_mac(input('mac> '))
		message = input('message> ').encode('utf-8')
		writeall(backend, b'm' + mac + bytes([len(message) >> 8, len(message) & 0xff]) + message)

	else:
		print('s - request status, i - request msgid, m - send message, ^D - quit')

# Create unbuffered version of stdin
unbuf_stdin = open(sys.stdin.buffer.fileno(), 'rb', buffering = 0)
	
_, interface, nick = sys.argv

proc = subprocess.Popen(['sudo', libexec_dir + '/ethermess-backend', interface], stdin = subprocess.PIPE, stdout = subprocess.PIPE, stderr = sys.stderr, bufsize = 0)

# Tell the backend the status and nick
status = 0
nick = nick.encode('utf-8')
writeall(proc.stdin, bytes([status, len(nick)]) + nick)

# Read our MAC
mac = readall(proc.stdout, 6)

print('Own mac: %s' % format_mac(mac))

print('s - request status, i - request msgid, m - send message, ^D - quit')

poll = select.poll()
poll.register(proc.stdout, select.POLLIN)
poll.register(unbuf_stdin, select.POLLIN)

input_buffer = bytearray()

running = True
while running:
	for fd, event in poll.poll():
		if fd == proc.stdout.fileno() and event & select.POLLIN:
			event_type = readall(proc.stdout, 1)
			if event_type == b's':
				# Status
				source_mac = readall(proc.stdout, 6)
				status, = readall(proc.stdout, 1)
				nick_length, = readall(proc.stdout, 1)
				nick = readall(proc.stdout, nick_length,)

				print('%s (%s) ~%s' % (format_mac(source_mac), format_status(status), nick.decode('utf-8')))

			else:
				# Not sth we handle yet
				data = proc.stdout.read(1023)
				if data == b'':
					data = b'[!] ' + event_type
				else:
					data = b'[!] ' + event_type + data
				sys.stdout.buffer.write(data)
				sys.stdout.buffer.flush()

		elif fd == proc.stdout.fileno() and event & select.POLLHUP:
			print('Backend exited')
			running = False

		elif fd == unbuf_stdin.fileno() and event & select.POLLIN:
			data = unbuf_stdin.read(1024)
			input_buffer.extend(data)

			while True:
				newline_location = input_buffer.find(b'\n')
				if newline_location == -1:
					break

				line, _, input_buffer = input_buffer.partition(b'\n')
				handle_user_command(proc.stdin, line.decode('utf-8'))

			if data == b'':
				# ^D
				writeall(proc.stdin, b'q')
				running = False

		else:
			raise Exception('Unreachable')

proc.wait()