We add the ConsoleSocket object, which has a socket interface and which will consume all arriving characters on the socket, placing them into an in memory buffer. This will also provide those chars via recv() as would a regular socket. ConsoleSocket also has the option of dumping the console bytes to a log file. We also give QEMUMachine the option of using ConsoleSocket to drain and to use for logging console to a file. By default QEMUMachine does not use ConsoleSocket. This is added in preparation for use by basevm.py in a later commit. This is a workaround we found was needed for basevm.py since there is a known issue where QEMU will hang waiting for console characters to be consumed. Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Cleber Rosa <crosa@redhat.com> Signed-off-by: Robert Foley <robert.foley@linaro.org> Reviewed-by: Peter Puhov <peter.puhov@linaro.org> Acked-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20200601211421.1277-9-robert.foley@linaro.org> Message-Id: <20200701135652.1366-13-alex.bennee@linaro.org>
		
			
				
	
	
		
			111 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			111 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
#!/usr/bin/env python3
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#
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# This python module implements a ConsoleSocket object which is
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# designed always drain the socket itself, and place
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# the bytes into a in memory buffer for later processing.
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#
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# Optionally a file path can be passed in and we will also
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# dump the characters to this file for debug.
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#
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# Copyright 2020 Linaro
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#
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# Authors:
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#  Robert Foley <robert.foley@linaro.org>
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#
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# This code is licensed under the GPL version 2 or later.  See
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# the COPYING file in the top-level directory.
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#
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import asyncore
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import socket
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import threading
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import io
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import os
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import sys
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from collections import deque
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import time
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import traceback
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class ConsoleSocket(asyncore.dispatcher):
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    def __init__(self, address, file=None):
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        self._recv_timeout_sec = 300
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        self._buffer = deque()
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        self._asyncore_thread = None
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        self._sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
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        self._sock.connect(address)
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        self._logfile = None
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        if file:
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            self._logfile = open(file, "w")
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        asyncore.dispatcher.__init__(self, sock=self._sock)
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        self._open = True
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        self._thread_start()
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    def _thread_start(self):
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        """Kick off a thread to wait on the asyncore.loop"""
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        if self._asyncore_thread is not None:
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            return
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        self._asyncore_thread = threading.Thread(target=asyncore.loop,
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                                                 kwargs={'timeout':1})
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        self._asyncore_thread.daemon = True
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        self._asyncore_thread.start()
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    def handle_close(self):
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        """redirect close to base class"""
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        # Call the base class close, but not self.close() since
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        # handle_close() occurs in the context of the thread which
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        # self.close() attempts to join.
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        asyncore.dispatcher.close(self)
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    def close(self):
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        """Close the base object and wait for the thread to terminate"""
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        if self._open:
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            self._open = False
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            asyncore.dispatcher.close(self)
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            if self._asyncore_thread is not None:
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                thread, self._asyncore_thread = self._asyncore_thread, None
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                thread.join()
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            if self._logfile:
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                self._logfile.close()
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                self._logfile = None
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    def handle_read(self):
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        """process arriving characters into in memory _buffer"""
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        try:
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            data = asyncore.dispatcher.recv(self, 1)
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            # latin1 is needed since there are some chars
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            # we are receiving that cannot be encoded to utf-8
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            # such as 0xe2, 0x80, 0xA6.
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            string = data.decode("latin1")
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        except:
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            print("Exception seen.")
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            traceback.print_exc()
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            return
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        if self._logfile:
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            self._logfile.write("{}".format(string))
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            self._logfile.flush()
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        for c in string:
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            self._buffer.extend(c)
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    def recv(self, n=1, sleep_delay_s=0.1):
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        """Return chars from in memory buffer"""
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        start_time = time.time()
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        while len(self._buffer) < n:
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            time.sleep(sleep_delay_s)
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            elapsed_sec = time.time() - start_time
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            if elapsed_sec > self._recv_timeout_sec:
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                raise socket.timeout
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        chars = ''.join([self._buffer.popleft() for i in range(n)])
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        # We choose to use latin1 to remain consistent with
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        # handle_read() and give back the same data as the user would
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        # receive if they were reading directly from the
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        # socket w/o our intervention.
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        return chars.encode("latin1")
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    def set_blocking(self):
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        """Maintain compatibility with socket API"""
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        pass
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    def settimeout(self, seconds):
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        """Set current timeout on recv"""
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        self._recv_timeout_sec = seconds
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