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Diffstat (limited to 'util/ec3po/interpreter.py')
| -rw-r--r-- | util/ec3po/interpreter.py | 467 |
1 files changed, 0 insertions, 467 deletions
diff --git a/util/ec3po/interpreter.py b/util/ec3po/interpreter.py deleted file mode 100644 index 4e151083bd..0000000000 --- a/util/ec3po/interpreter.py +++ /dev/null @@ -1,467 +0,0 @@ -# Copyright 2015 The Chromium OS Authors. All rights reserved. -# Use of this source code is governed by a BSD-style license that can be -# found in the LICENSE file. - -"""EC-3PO EC Interpreter - -interpreter provides the interpretation layer between the EC UART and the user. -It receives commands through its command pipe, formats the commands for the EC, -and sends the command to the EC. It also presents data from the EC to either be -displayed via the interactive console interface, or some other consumer. It -additionally supports automatic command retrying if the EC drops a character in -a command. -""" - -# Note: This is a py2/3 compatible file. - -from __future__ import print_function - -import binascii -import copy -import logging -import os -import select -import traceback - -import six - - -COMMAND_RETRIES = 3 # Number of attempts to retry a command. -EC_MAX_READ = 1024 # Max bytes to read at a time from the EC. -EC_SYN = b'\xec' # Byte indicating EC interrogation. -EC_ACK = b'\xc0' # Byte representing correct EC response to interrogation. - - -class LoggerAdapter(logging.LoggerAdapter): - """Class which provides a small adapter for the logger.""" - - def process(self, msg, kwargs): - """Prepends the served PTY to the beginning of the log message.""" - return '%s - %s' % (self.extra['pty'], msg), kwargs - - -class Interpreter(object): - """Class which provides the interpretation layer between the EC and user. - - This class essentially performs all of the intepretation for the EC and the - user. It handles all of the automatic command retrying as well as the - formation of commands for EC images which support that. - - Attributes: - logger: A logger for this module. - ec_uart_pty: An opened file object to the raw EC UART PTY. - ec_uart_pty_name: A string containing the name of the raw EC UART PTY. - cmd_pipe: A socket.socket or multiprocessing.Connection object which - represents the Interpreter side of the command pipe. This must be a - bidirectional pipe. Commands and responses will utilize this pipe. - dbg_pipe: A socket.socket or multiprocessing.Connection object which - represents the Interpreter side of the debug pipe. This must be a - unidirectional pipe with write capabilities. EC debug output will utilize - this pipe. - cmd_retries: An integer representing the number of attempts the console - should retry commands if it receives an error. - log_level: An integer representing the numeric value of the log level. - inputs: A list of objects that the intpreter selects for reading. - Initially, these are the EC UART and the command pipe. - outputs: A list of objects that the interpreter selects for writing. - ec_cmd_queue: A FIFO queue used for sending commands down to the EC UART. - last_cmd: A string that represents the last command sent to the EC. If an - error is encountered, the interpreter will attempt to retry this command - up to COMMAND_RETRIES. - enhanced_ec: A boolean indicating if the EC image that we are currently - communicating with is enhanced or not. Enhanced EC images will support - packed commands and host commands over the UART. This defaults to False - and is changed depending on the result of an interrogation. - interrogating: A boolean indicating if we are in the middle of interrogating - the EC. - connected: A boolean indicating if the interpreter is actually connected to - the UART and listening. - """ - def __init__(self, ec_uart_pty, cmd_pipe, dbg_pipe, log_level=logging.INFO, - name=None): - """Intializes an Interpreter object with the provided args. - - Args: - ec_uart_pty: A string representing the EC UART to connect to. - cmd_pipe: A socket.socket or multiprocessing.Connection object which - represents the Interpreter side of the command pipe. This must be a - bidirectional pipe. Commands and responses will utilize this pipe. - dbg_pipe: A socket.socket or multiprocessing.Connection object which - represents the Interpreter side of the debug pipe. This must be a - unidirectional pipe with write capabilities. EC debug output will - utilize this pipe. - cmd_retries: An integer representing the number of attempts the console - should retry commands if it receives an error. - log_level: An optional integer representing the numeric value of the log - level. By default, the log level will be logging.INFO (20). - name: the console source name - """ - # Create a unique logger based on the interpreter name - interpreter_prefix = ('%s - ' % name) if name else '' - logger = logging.getLogger('%sEC3PO.Interpreter' % interpreter_prefix) - self.logger = LoggerAdapter(logger, {'pty': ec_uart_pty}) - # TODO(https://crbug.com/1162189): revist the 2 TODOs below - # TODO(https://bugs.python.org/issue27805, python3.7+): revert to ab+ - # TODO(https://bugs.python.org/issue20074): removing buffering=0 if/when - # that gets fixed, or keep two pty: one for reading and one for writing - self.ec_uart_pty = open(ec_uart_pty, 'r+b', buffering=0) - self.ec_uart_pty_name = ec_uart_pty - self.cmd_pipe = cmd_pipe - self.dbg_pipe = dbg_pipe - self.cmd_retries = COMMAND_RETRIES - self.log_level = log_level - self.inputs = [self.ec_uart_pty, self.cmd_pipe] - self.outputs = [] - self.ec_cmd_queue = six.moves.queue.Queue() - self.last_cmd = b'' - self.enhanced_ec = False - self.interrogating = False - self.connected = True - - def __str__(self): - """Show internal state of the Interpreter object. - - Returns: - A string that shows the values of the attributes. - """ - string = [] - string.append('%r' % self) - string.append('ec_uart_pty: %s' % self.ec_uart_pty) - string.append('cmd_pipe: %r' % self.cmd_pipe) - string.append('dbg_pipe: %r' % self.dbg_pipe) - string.append('cmd_retries: %d' % self.cmd_retries) - string.append('log_level: %d' % self.log_level) - string.append('inputs: %r' % self.inputs) - string.append('outputs: %r' % self.outputs) - string.append('ec_cmd_queue: %r' % self.ec_cmd_queue) - string.append('last_cmd: \'%s\'' % self.last_cmd) - string.append('enhanced_ec: %r' % self.enhanced_ec) - string.append('interrogating: %r' % self.interrogating) - return '\n'.join(string) - - def EnqueueCmd(self, command): - """Enqueue a command to be sent to the EC UART. - - Args: - command: A string which contains the command to be sent. - """ - self.ec_cmd_queue.put(command) - self.logger.log(1, 'Commands now in queue: %d', self.ec_cmd_queue.qsize()) - - # Add the EC UART as an output to be serviced. - if self.connected and self.ec_uart_pty not in self.outputs: - self.outputs.append(self.ec_uart_pty) - - def PackCommand(self, raw_cmd): - r"""Packs a command for use with error checking. - - For error checking, we pack console commands in a particular format. The - format is as follows: - - &&[x][x][x][x]&{cmd}\n\n - ^ ^ ^^ ^^ ^ ^-- 2 newlines. - | | || || |-- the raw console command. - | | || ||-- 1 ampersand. - | | ||____|--- 2 hex digits representing the CRC8 of cmd. - | |____|-- 2 hex digits reprsenting the length of cmd. - |-- 2 ampersands - - Args: - raw_cmd: A pre-packed string which contains the raw command. - - Returns: - A string which contains the packed command. - """ - # Don't pack a single carriage return. - if raw_cmd != b'\r': - # The command format is as follows. - # &&[x][x][x][x]&{cmd}\n\n - packed_cmd = [] - packed_cmd.append(b'&&') - # The first pair of hex digits are the length of the command. - packed_cmd.append(b'%02x' % len(raw_cmd)) - # Then the CRC8 of cmd. - packed_cmd.append(b'%02x' % Crc8(raw_cmd)) - packed_cmd.append(b'&') - # Now, the raw command followed by 2 newlines. - packed_cmd.append(raw_cmd) - packed_cmd.append(b'\n\n') - return b''.join(packed_cmd) - else: - return raw_cmd - - def ProcessCommand(self, command): - """Captures the input determines what actions to take. - - Args: - command: A string representing the command sent by the user. - """ - if command == b'disconnect': - if self.connected: - self.logger.debug('UART disconnect request.') - # Drop all pending commands if any. - while not self.ec_cmd_queue.empty(): - c = self.ec_cmd_queue.get() - self.logger.debug('dropped: \'%s\'', c) - if self.enhanced_ec: - # Reset retry state. - self.cmd_retries = COMMAND_RETRIES - self.last_cmd = b'' - # Get the UART that the interpreter is attached to. - fileobj = self.ec_uart_pty - self.logger.debug('fileobj: %r', fileobj) - # Remove the descriptor from the inputs and outputs. - self.inputs.remove(fileobj) - if fileobj in self.outputs: - self.outputs.remove(fileobj) - self.logger.debug('Removed fileobj. Remaining inputs: %r', self.inputs) - # Close the file. - fileobj.close() - # Mark the interpreter as disconnected now. - self.connected = False - self.logger.debug('Disconnected from %s.', self.ec_uart_pty_name) - return - - elif command == b'reconnect': - if not self.connected: - self.logger.debug('UART reconnect request.') - # Reopen the PTY. - # TODO(https://bugs.python.org/issue27805, python3.7+): revert to ab+ - # TODO(https://bugs.python.org/issue20074): removing buffering=0 if/when - # that gets fixed, or keep two pty: one for reading and one for writing - fileobj = open(self.ec_uart_pty_name, 'r+b', buffering=0) - self.logger.debug('fileobj: %r', fileobj) - self.ec_uart_pty = fileobj - # Add the descriptor to the inputs. - self.inputs.append(fileobj) - self.logger.debug('fileobj added. curr inputs: %r', self.inputs) - # Mark the interpreter as connected now. - self.connected = True - self.logger.debug('Connected to %s.', self.ec_uart_pty_name) - return - - elif command.startswith(b'enhanced'): - self.enhanced_ec = command.split(b' ')[1] == b'True' - return - - # Ignore any other commands while in the disconnected state. - self.logger.log(1, 'command: \'%s\'', command) - if not self.connected: - self.logger.debug('Ignoring command because currently disconnected.') - return - - # Remove leading and trailing spaces only if this is an enhanced EC image. - # For non-enhanced EC images, commands will be single characters at a time - # and can be spaces. - if self.enhanced_ec: - command = command.strip(b' ') - - # There's nothing to do if the command is empty. - if len(command) == 0: - return - - # Handle log level change requests. - if command.startswith(b'loglevel'): - self.logger.debug('Log level change request.') - new_log_level = int(command.split(b' ')[1]) - self.logger.logger.setLevel(new_log_level) - self.logger.info('Log level changed to %d.', new_log_level) - return - - # Check for interrogation command. - if command == EC_SYN: - # User is requesting interrogation. Send SYN as is. - self.logger.debug('User requesting interrogation.') - self.interrogating = True - # Assume the EC isn't enhanced until we get a response. - self.enhanced_ec = False - elif self.enhanced_ec: - # Enhanced EC images require the plaintext commands to be packed. - command = self.PackCommand(command) - # TODO(aaboagye): Make a dict of commands and keys and eventually, - # handle partial matching based on unique prefixes. - - self.EnqueueCmd(command) - - def HandleCmdRetries(self): - """Attempts to retry commands if possible.""" - if self.cmd_retries > 0: - # The EC encountered an error. We'll have to retry again. - self.logger.warning('Retrying command...') - self.cmd_retries -= 1 - self.logger.warning('Retries remaining: %d', self.cmd_retries) - # Retry the command and add the EC UART to the writers again. - self.EnqueueCmd(self.last_cmd) - self.outputs.append(self.ec_uart_pty) - else: - # We're out of retries, so just give up. - self.logger.error('Command failed. No retries left.') - # Clear the command in progress. - self.last_cmd = b'' - # Reset the retry count. - self.cmd_retries = COMMAND_RETRIES - - def SendCmdToEC(self): - """Sends a command to the EC.""" - # If we're retrying a command, just try to send it again. - if self.cmd_retries < COMMAND_RETRIES: - cmd = self.last_cmd - else: - # If we're not retrying, we should not be writing to the EC if we have no - # items in our command queue. - assert not self.ec_cmd_queue.empty() - # Get the command to send. - cmd = self.ec_cmd_queue.get() - - # Send the command. - self.ec_uart_pty.write(cmd) - self.ec_uart_pty.flush() - self.logger.log(1, 'Sent command to EC.') - - if self.enhanced_ec and cmd != EC_SYN: - # Now, that we've sent the command, store the current command as the last - # command sent. If we encounter an error string, we will attempt to retry - # this command. - if cmd != self.last_cmd: - self.last_cmd = cmd - # Reset the retry count. - self.cmd_retries = COMMAND_RETRIES - - # If no command is pending to be sent, then we can remove the EC UART from - # writers. Might need better checking for command retry logic in here. - if self.ec_cmd_queue.empty(): - # Remove the EC UART from the writers while we wait for a response. - self.logger.debug('Removing EC UART from writers.') - self.outputs.remove(self.ec_uart_pty) - - def HandleECData(self): - """Handle any debug prints from the EC.""" - self.logger.log(1, 'EC has data') - # Read what the EC sent us. - data = os.read(self.ec_uart_pty.fileno(), EC_MAX_READ) - self.logger.log(1, 'got: \'%s\'', binascii.hexlify(data)) - if b'&E' in data and self.enhanced_ec: - # We received an error, so we should retry it if possible. - self.logger.warning('Error string found in data.') - self.HandleCmdRetries() - return - - # If we were interrogating, check the response and update our knowledge - # of the current EC image. - if self.interrogating: - self.enhanced_ec = data == EC_ACK - if self.enhanced_ec: - self.logger.debug('The current EC image seems enhanced.') - else: - self.logger.debug('The current EC image does NOT seem enhanced.') - # Done interrogating. - self.interrogating = False - # For now, just forward everything the EC sends us. - self.logger.log(1, 'Forwarding to user...') - self.dbg_pipe.send(data) - - def HandleUserData(self): - """Handle any incoming commands from the user. - - Raises: - EOFError: Allowed to propagate through from self.cmd_pipe.recv(). - """ - self.logger.log(1, 'Command data available. Begin processing.') - data = self.cmd_pipe.recv() - # Process the command. - self.ProcessCommand(data) - - -def Crc8(data): - """Calculates the CRC8 of data. - - The generator polynomial used is: x^8 + x^2 + x + 1. - This is the same implementation that is used in the EC. - - Args: - data: A string of data that we wish to calculate the CRC8 on. - - Returns: - crc >> 8: An integer representing the CRC8 value. - """ - crc = 0 - for byte in six.iterbytes(data): - crc ^= (byte << 8) - for _ in range(8): - if crc & 0x8000: - crc ^= (0x1070 << 3) - crc <<= 1 - return crc >> 8 - - -def StartLoop(interp, shutdown_pipe=None): - """Starts an infinite loop of servicing the user and the EC. - - StartLoop checks to see if there are any commands to process, processing them - if any, and forwards EC output to the user. - - When sending a command to the EC, we send the command once and check the - response to see if the EC encountered an error when receiving the command. An - error condition is reported to the interpreter by a string with at least one - '&' and 'E'. The full string is actually '&&EE', however it's possible that - the leading ampersand or trailing 'E' could be dropped. If an error is - encountered, the interpreter will retry up to the amount configured. - - Args: - interp: An Interpreter object that has been properly initialised. - shutdown_pipe: A file object for a pipe or equivalent that becomes readable - (not blocked) to indicate that the loop should exit. Can be None to never - exit the loop. - """ - try: - # This is used instead of "break" to avoid exiting the loop in the middle of - # an iteration. - continue_looping = True - - while continue_looping: - # The inputs list is created anew in each loop iteration because the - # Interpreter class sometimes modifies the interp.inputs list. - if shutdown_pipe is None: - inputs = interp.inputs - else: - inputs = list(interp.inputs) - inputs.append(shutdown_pipe) - - readable, writeable, _ = select.select(inputs, interp.outputs, []) - - for obj in readable: - # Handle any debug prints from the EC. - if obj is interp.ec_uart_pty: - interp.HandleECData() - - # Handle any commands from the user. - elif obj is interp.cmd_pipe: - try: - interp.HandleUserData() - except EOFError: - interp.logger.debug( - 'ec3po interpreter received EOF from cmd_pipe in ' - 'HandleUserData()') - continue_looping = False - - elif obj is shutdown_pipe: - interp.logger.debug( - 'ec3po interpreter received shutdown pipe unblocked notification') - continue_looping = False - - for obj in writeable: - # Send a command to the EC. - if obj is interp.ec_uart_pty: - interp.SendCmdToEC() - - except KeyboardInterrupt: - pass - - finally: - interp.cmd_pipe.close() - interp.dbg_pipe.close() - interp.ec_uart_pty.close() - if shutdown_pipe is not None: - shutdown_pipe.close() - interp.logger.debug('Exit ec3po interpreter loop for %s', - interp.ec_uart_pty_name) |