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#
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#
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4 db4e138b Manuel Franceschini
# Copyright (C) 2007, 2008, 2010 Google Inc.
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful, but
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# WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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# General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301, USA.
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"""HTTP server module.
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"""
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import BaseHTTPServer
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import cgi
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import logging
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import os
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import socket
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import time
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import signal
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import asyncore
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from ganeti import http
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from ganeti import utils
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from ganeti import netutils
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WEEKDAYNAME = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
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MONTHNAME = [None,
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             "Jan", "Feb", "Mar", "Apr", "May", "Jun",
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             "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
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# Default error message
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DEFAULT_ERROR_CONTENT_TYPE = "text/html"
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DEFAULT_ERROR_MESSAGE = """\
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<html>
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<head>
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<title>Error response</title>
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</head>
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<body>
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<h1>Error response</h1>
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<p>Error code %(code)d.
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<p>Message: %(message)s.
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<p>Error code explanation: %(code)s = %(explain)s.
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</body>
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</html>
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"""
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def _DateTimeHeader(gmnow=None):
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  """Return the current date and time formatted for a message header.
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  The time MUST be in the GMT timezone.
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  """
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  if gmnow is None:
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    gmnow = time.gmtime()
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  (year, month, day, hh, mm, ss, wd, _, _) = gmnow
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  return ("%s, %02d %3s %4d %02d:%02d:%02d GMT" %
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          (WEEKDAYNAME[wd], day, MONTHNAME[month], year, hh, mm, ss))
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class _HttpServerRequest(object):
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  """Data structure for HTTP request on server side.
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  """
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  def __init__(self, method, path, headers, body):
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    # Request attributes
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    self.request_method = method
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    self.request_path = path
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    self.request_headers = headers
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    self.request_body = body
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    # Response attributes
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    self.resp_headers = {}
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    # Private data for request handler (useful in combination with
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    # authentication)
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    self.private = None
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  def __repr__(self):
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    status = ["%s.%s" % (self.__class__.__module__, self.__class__.__name__),
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              self.request_method, self.request_path,
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              "headers=%r" % str(self.request_headers),
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              "body=%r" % (self.request_body, )]
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    return "<%s at %#x>" % (" ".join(status), id(self))
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class _HttpServerToClientMessageWriter(http.HttpMessageWriter):
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  """Writes an HTTP response to client.
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  """
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  def __init__(self, sock, request_msg, response_msg, write_timeout):
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    """Writes the response to the client.
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    @type sock: socket
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    @param sock: Target socket
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    @type request_msg: http.HttpMessage
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    @param request_msg: Request message, required to determine whether
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        response may have a message body
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    @type response_msg: http.HttpMessage
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    @param response_msg: Response message
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    @type write_timeout: float
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    @param write_timeout: Write timeout for socket
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    """
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    self._request_msg = request_msg
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    self._response_msg = response_msg
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    http.HttpMessageWriter.__init__(self, sock, response_msg, write_timeout)
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  def HasMessageBody(self):
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    """Logic to detect whether response should contain a message body.
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    """
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    if self._request_msg.start_line:
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      request_method = self._request_msg.start_line.method
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    else:
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      request_method = None
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    response_code = self._response_msg.start_line.code
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    # RFC2616, section 4.3: "A message-body MUST NOT be included in a request
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    # if the specification of the request method (section 5.1.1) does not allow
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    # sending an entity-body in requests"
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    #
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    # RFC2616, section 9.4: "The HEAD method is identical to GET except that
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    # the server MUST NOT return a message-body in the response."
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    #
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    # RFC2616, section 10.2.5: "The 204 response MUST NOT include a
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    # message-body [...]"
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    #
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    # RFC2616, section 10.3.5: "The 304 response MUST NOT contain a
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    # message-body, [...]"
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    return (http.HttpMessageWriter.HasMessageBody(self) and
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            (request_method is not None and
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             request_method != http.HTTP_HEAD) and
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            response_code >= http.HTTP_OK and
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            response_code not in (http.HTTP_NO_CONTENT,
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                                  http.HTTP_NOT_MODIFIED))
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class _HttpClientToServerMessageReader(http.HttpMessageReader):
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  """Reads an HTTP request sent by client.
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  """
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  # Length limits
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  START_LINE_LENGTH_MAX = 4096
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  HEADER_LENGTH_MAX = 4096
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  def ParseStartLine(self, start_line):
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    """Parses the start line sent by client.
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    Example: "GET /index.html HTTP/1.1"
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    @type start_line: string
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    @param start_line: Start line
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    """
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    # Empty lines are skipped when reading
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    assert start_line
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    logging.debug("HTTP request: %s", start_line)
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    words = start_line.split()
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    if len(words) == 3:
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      [method, path, version] = words
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      if version[:5] != "HTTP/":
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        raise http.HttpBadRequest("Bad request version (%r)" % version)
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      try:
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        base_version_number = version.split("/", 1)[1]
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        version_number = base_version_number.split(".")
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        # RFC 2145 section 3.1 says there can be only one "." and
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        #   - major and minor numbers MUST be treated as
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        #      separate integers;
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        #   - HTTP/2.4 is a lower version than HTTP/2.13, which in
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        #      turn is lower than HTTP/12.3;
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        #   - Leading zeros MUST be ignored by recipients.
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        if len(version_number) != 2:
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          raise http.HttpBadRequest("Bad request version (%r)" % version)
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        version_number = (int(version_number[0]), int(version_number[1]))
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      except (ValueError, IndexError):
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        raise http.HttpBadRequest("Bad request version (%r)" % version)
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      if version_number >= (2, 0):
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        raise http.HttpVersionNotSupported("Invalid HTTP Version (%s)" %
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                                      base_version_number)
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    elif len(words) == 2:
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      version = http.HTTP_0_9
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      [method, path] = words
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      if method != http.HTTP_GET:
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        raise http.HttpBadRequest("Bad HTTP/0.9 request type (%r)" % method)
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    else:
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      raise http.HttpBadRequest("Bad request syntax (%r)" % start_line)
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    return http.HttpClientToServerStartLine(method, path, version)
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def HandleServerRequest(handler, req_msg):
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  """Calls the handler function for the current request.
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  """
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  handler_context = _HttpServerRequest(req_msg.start_line.method,
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                                       req_msg.start_line.path,
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                                       req_msg.headers,
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                                       req_msg.body)
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  logging.debug("Handling request %r", handler_context)
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  try:
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    try:
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      # Authentication, etc.
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      handler.PreHandleRequest(handler_context)
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      # Call actual request handler
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      result = handler.HandleRequest(handler_context)
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    except (http.HttpException, KeyboardInterrupt, SystemExit):
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      raise
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    except Exception, err:
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      logging.exception("Caught exception")
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      raise http.HttpInternalServerError(message=str(err))
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    except:
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      logging.exception("Unknown exception")
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      raise http.HttpInternalServerError(message="Unknown error")
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    if not isinstance(result, basestring):
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      raise http.HttpError("Handler function didn't return string type")
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    return (http.HTTP_OK, handler_context.resp_headers, result)
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  finally:
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    # No reason to keep this any longer, even for exceptions
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    handler_context.private = None
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class HttpServerRequestExecutor(object):
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  """Implements server side of HTTP.
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  This class implements the server side of HTTP. It's based on code of
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  Python's BaseHTTPServer, from both version 2.4 and 3k. It does not
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  support non-ASCII character encodings. Keep-alive connections are
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  not supported.
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  """
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  # The default request version.  This only affects responses up until
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  # the point where the request line is parsed, so it mainly decides what
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  # the client gets back when sending a malformed request line.
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  # Most web servers default to HTTP 0.9, i.e. don't send a status line.
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  default_request_version = http.HTTP_0_9
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  # Error message settings
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  error_message_format = DEFAULT_ERROR_MESSAGE
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  error_content_type = DEFAULT_ERROR_CONTENT_TYPE
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  responses = BaseHTTPServer.BaseHTTPRequestHandler.responses
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  # Timeouts in seconds for socket layer
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  WRITE_TIMEOUT = 10
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  READ_TIMEOUT = 10
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  CLOSE_TIMEOUT = 1
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  def __init__(self, server, sock, client_addr):
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    """Initializes this class.
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    """
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    self.server = server
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    self.sock = sock
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    self.client_addr = client_addr
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    self.request_msg = http.HttpMessage()
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    self.response_msg = http.HttpMessage()
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    self.response_msg.start_line = \
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      http.HttpServerToClientStartLine(version=self.default_request_version,
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                                       code=None, reason=None)
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    # Disable Python's timeout
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    self.sock.settimeout(None)
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    # Operate in non-blocking mode
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    self.sock.setblocking(0)
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    logging.debug("Connection from %s:%s", client_addr[0], client_addr[1])
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    try:
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      request_msg_reader = None
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      force_close = True
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      try:
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        # Do the secret SSL handshake
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        if self.server.using_ssl:
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          self.sock.set_accept_state()
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          try:
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            http.Handshake(self.sock, self.WRITE_TIMEOUT)
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          except http.HttpSessionHandshakeUnexpectedEOF:
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            # Ignore rest
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            return
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        try:
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          try:
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            request_msg_reader = self._ReadRequest()
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            # RFC2616, 14.23: All Internet-based HTTP/1.1 servers MUST respond
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            # with a 400 (Bad Request) status code to any HTTP/1.1 request
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            # message which lacks a Host header field.
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            if (self.request_msg.start_line.version == http.HTTP_1_1 and
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                http.HTTP_HOST not in self.request_msg.headers):
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              raise http.HttpBadRequest(message="Missing Host header")
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            (self.response_msg.start_line.code, self.response_msg.headers,
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             self.response_msg.body) = \
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              HandleServerRequest(self.server, self.request_msg)
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            # Only wait for client to close if we didn't have any exception.
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            force_close = False
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          except http.HttpException, err:
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            self._SetErrorStatus(err)
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        finally:
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          # Try to send a response
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          self._SendResponse()
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      finally:
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        http.ShutdownConnection(sock, self.CLOSE_TIMEOUT, self.WRITE_TIMEOUT,
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                                request_msg_reader, force_close)
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      self.sock.close()
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      self.sock = None
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    finally:
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      logging.debug("Disconnected %s:%s", client_addr[0], client_addr[1])
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  def _ReadRequest(self):
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    """Reads a request sent by client.
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    """
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    try:
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      request_msg_reader = \
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        _HttpClientToServerMessageReader(self.sock, self.request_msg,
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                                         self.READ_TIMEOUT)
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    except http.HttpSocketTimeout:
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      raise http.HttpError("Timeout while reading request")
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    except socket.error, err:
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      raise http.HttpError("Error reading request: %s" % err)
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    self.response_msg.start_line.version = self.request_msg.start_line.version
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    return request_msg_reader
361 02cab3e7 Michael Hanselmann
362 02cab3e7 Michael Hanselmann
  def _SendResponse(self):
363 02cab3e7 Michael Hanselmann
    """Sends the response to the client.
364 02cab3e7 Michael Hanselmann

365 02cab3e7 Michael Hanselmann
    """
366 02cab3e7 Michael Hanselmann
    if self.response_msg.start_line.code is None:
367 02cab3e7 Michael Hanselmann
      return
368 02cab3e7 Michael Hanselmann
369 02cab3e7 Michael Hanselmann
    if not self.response_msg.headers:
370 02cab3e7 Michael Hanselmann
      self.response_msg.headers = {}
371 02cab3e7 Michael Hanselmann
372 02cab3e7 Michael Hanselmann
    self.response_msg.headers.update({
373 02cab3e7 Michael Hanselmann
      # TODO: Keep-alive is not supported
374 02cab3e7 Michael Hanselmann
      http.HTTP_CONNECTION: "close",
375 02cab3e7 Michael Hanselmann
      http.HTTP_DATE: _DateTimeHeader(),
376 02cab3e7 Michael Hanselmann
      http.HTTP_SERVER: http.HTTP_GANETI_VERSION,
377 02cab3e7 Michael Hanselmann
      })
378 02cab3e7 Michael Hanselmann
379 02cab3e7 Michael Hanselmann
    # Get response reason based on code
380 02cab3e7 Michael Hanselmann
    response_code = self.response_msg.start_line.code
381 02cab3e7 Michael Hanselmann
    if response_code in self.responses:
382 02cab3e7 Michael Hanselmann
      response_reason = self.responses[response_code][0]
383 02cab3e7 Michael Hanselmann
    else:
384 02cab3e7 Michael Hanselmann
      response_reason = ""
385 02cab3e7 Michael Hanselmann
    self.response_msg.start_line.reason = response_reason
386 02cab3e7 Michael Hanselmann
387 02cab3e7 Michael Hanselmann
    logging.info("%s:%s %s %s", self.client_addr[0], self.client_addr[1],
388 02cab3e7 Michael Hanselmann
                 self.request_msg.start_line, response_code)
389 02cab3e7 Michael Hanselmann
390 02cab3e7 Michael Hanselmann
    try:
391 02cab3e7 Michael Hanselmann
      _HttpServerToClientMessageWriter(self.sock, self.request_msg,
392 02cab3e7 Michael Hanselmann
                                       self.response_msg, self.WRITE_TIMEOUT)
393 02cab3e7 Michael Hanselmann
    except http.HttpSocketTimeout:
394 02cab3e7 Michael Hanselmann
      raise http.HttpError("Timeout while sending response")
395 02cab3e7 Michael Hanselmann
    except socket.error, err:
396 02cab3e7 Michael Hanselmann
      raise http.HttpError("Error sending response: %s" % err)
397 02cab3e7 Michael Hanselmann
398 02cab3e7 Michael Hanselmann
  def _SetErrorStatus(self, err):
399 02cab3e7 Michael Hanselmann
    """Sets the response code and body from a HttpException.
400 02cab3e7 Michael Hanselmann

401 02cab3e7 Michael Hanselmann
    @type err: HttpException
402 02cab3e7 Michael Hanselmann
    @param err: Exception instance
403 02cab3e7 Michael Hanselmann

404 02cab3e7 Michael Hanselmann
    """
405 02cab3e7 Michael Hanselmann
    try:
406 02cab3e7 Michael Hanselmann
      (shortmsg, longmsg) = self.responses[err.code]
407 02cab3e7 Michael Hanselmann
    except KeyError:
408 02cab3e7 Michael Hanselmann
      shortmsg = longmsg = "Unknown"
409 02cab3e7 Michael Hanselmann
410 02cab3e7 Michael Hanselmann
    if err.message:
411 02cab3e7 Michael Hanselmann
      message = err.message
412 02cab3e7 Michael Hanselmann
    else:
413 02cab3e7 Michael Hanselmann
      message = shortmsg
414 02cab3e7 Michael Hanselmann
415 02cab3e7 Michael Hanselmann
    values = {
416 02cab3e7 Michael Hanselmann
      "code": err.code,
417 02cab3e7 Michael Hanselmann
      "message": cgi.escape(message),
418 02cab3e7 Michael Hanselmann
      "explain": longmsg,
419 02cab3e7 Michael Hanselmann
      }
420 02cab3e7 Michael Hanselmann
421 02cab3e7 Michael Hanselmann
    self.response_msg.start_line.code = err.code
422 a8e01e9f Michael Hanselmann
423 a8e01e9f Michael Hanselmann
    headers = {}
424 a8e01e9f Michael Hanselmann
    if err.headers:
425 a8e01e9f Michael Hanselmann
      headers.update(err.headers)
426 a8e01e9f Michael Hanselmann
    headers[http.HTTP_CONTENT_TYPE] = self.error_content_type
427 a8e01e9f Michael Hanselmann
    self.response_msg.headers = headers
428 a8e01e9f Michael Hanselmann
429 1f8588f6 Iustin Pop
    self.response_msg.body = self._FormatErrorMessage(values)
430 02cab3e7 Michael Hanselmann
431 1f8588f6 Iustin Pop
  def _FormatErrorMessage(self, values):
432 1f8588f6 Iustin Pop
    """Formats the body of an error message.
433 1f8588f6 Iustin Pop

434 1f8588f6 Iustin Pop
    @type values: dict
435 1f8588f6 Iustin Pop
    @param values: dictionary with keys code, message and explain.
436 1f8588f6 Iustin Pop
    @rtype: string
437 1f8588f6 Iustin Pop
    @return: the body of the message
438 1f8588f6 Iustin Pop

439 1f8588f6 Iustin Pop
    """
440 1f8588f6 Iustin Pop
    return self.error_message_format % values
441 02cab3e7 Michael Hanselmann
442 57fd6d0b Michael Hanselmann
443 112d240d Guido Trotter
class HttpServer(http.HttpBase, asyncore.dispatcher):
444 02cab3e7 Michael Hanselmann
  """Generic HTTP server class
445 02cab3e7 Michael Hanselmann

446 02cab3e7 Michael Hanselmann
  Users of this class must subclass it and override the HandleRequest function.
447 02cab3e7 Michael Hanselmann

448 02cab3e7 Michael Hanselmann
  """
449 02cab3e7 Michael Hanselmann
  MAX_CHILDREN = 20
450 02cab3e7 Michael Hanselmann
451 02cab3e7 Michael Hanselmann
  def __init__(self, mainloop, local_address, port,
452 1f8588f6 Iustin Pop
               ssl_params=None, ssl_verify_peer=False,
453 1f8588f6 Iustin Pop
               request_executor_class=None):
454 02cab3e7 Michael Hanselmann
    """Initializes the HTTP server
455 02cab3e7 Michael Hanselmann

456 02cab3e7 Michael Hanselmann
    @type mainloop: ganeti.daemon.Mainloop
457 02cab3e7 Michael Hanselmann
    @param mainloop: Mainloop used to poll for I/O events
458 c41eea6e Iustin Pop
    @type local_address: string
459 02cab3e7 Michael Hanselmann
    @param local_address: Local IP address to bind to
460 02cab3e7 Michael Hanselmann
    @type port: int
461 02cab3e7 Michael Hanselmann
    @param port: TCP port to listen on
462 02cab3e7 Michael Hanselmann
    @type ssl_params: HttpSslParams
463 02cab3e7 Michael Hanselmann
    @param ssl_params: SSL key and certificate
464 02cab3e7 Michael Hanselmann
    @type ssl_verify_peer: bool
465 25e7b43f Iustin Pop
    @param ssl_verify_peer: Whether to require client certificate
466 25e7b43f Iustin Pop
        and compare it with our certificate
467 1f8588f6 Iustin Pop
    @type request_executor_class: class
468 1f8588f6 Iustin Pop
    @param request_executor_class: an class derived from the
469 1f8588f6 Iustin Pop
        HttpServerRequestExecutor class
470 02cab3e7 Michael Hanselmann

471 02cab3e7 Michael Hanselmann
    """
472 f4322a1e Michael Hanselmann
    http.HttpBase.__init__(self)
473 112d240d Guido Trotter
    asyncore.dispatcher.__init__(self)
474 02cab3e7 Michael Hanselmann
475 1f8588f6 Iustin Pop
    if request_executor_class is None:
476 1f8588f6 Iustin Pop
      self.request_executor = HttpServerRequestExecutor
477 1f8588f6 Iustin Pop
    else:
478 1f8588f6 Iustin Pop
      self.request_executor = request_executor_class
479 1f8588f6 Iustin Pop
480 02cab3e7 Michael Hanselmann
    self.mainloop = mainloop
481 02cab3e7 Michael Hanselmann
    self.local_address = local_address
482 02cab3e7 Michael Hanselmann
    self.port = port
483 db4e138b Manuel Franceschini
    family = netutils.IPAddress.GetAddressFamily(local_address)
484 db4e138b Manuel Franceschini
    self.socket = self._CreateSocket(ssl_params, ssl_verify_peer, family)
485 02cab3e7 Michael Hanselmann
486 02cab3e7 Michael Hanselmann
    # Allow port to be reused
487 02cab3e7 Michael Hanselmann
    self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
488 02cab3e7 Michael Hanselmann
489 02cab3e7 Michael Hanselmann
    self._children = []
490 112d240d Guido Trotter
    self.set_socket(self.socket)
491 112d240d Guido Trotter
    self.accepting = True
492 02cab3e7 Michael Hanselmann
    mainloop.RegisterSignal(self)
493 02cab3e7 Michael Hanselmann
494 02cab3e7 Michael Hanselmann
  def Start(self):
495 02cab3e7 Michael Hanselmann
    self.socket.bind((self.local_address, self.port))
496 59305197 Michael Hanselmann
    self.socket.listen(1024)
497 02cab3e7 Michael Hanselmann
498 02cab3e7 Michael Hanselmann
  def Stop(self):
499 02cab3e7 Michael Hanselmann
    self.socket.close()
500 02cab3e7 Michael Hanselmann
501 112d240d Guido Trotter
  def handle_accept(self):
502 112d240d Guido Trotter
    self._IncomingConnection()
503 02cab3e7 Michael Hanselmann
504 02cab3e7 Michael Hanselmann
  def OnSignal(self, signum):
505 02cab3e7 Michael Hanselmann
    if signum == signal.SIGCHLD:
506 02cab3e7 Michael Hanselmann
      self._CollectChildren(True)
507 02cab3e7 Michael Hanselmann
508 02cab3e7 Michael Hanselmann
  def _CollectChildren(self, quick):
509 02cab3e7 Michael Hanselmann
    """Checks whether any child processes are done
510 02cab3e7 Michael Hanselmann

511 02cab3e7 Michael Hanselmann
    @type quick: bool
512 02cab3e7 Michael Hanselmann
    @param quick: Whether to only use non-blocking functions
513 02cab3e7 Michael Hanselmann

514 02cab3e7 Michael Hanselmann
    """
515 02cab3e7 Michael Hanselmann
    if not quick:
516 02cab3e7 Michael Hanselmann
      # Don't wait for other processes if it should be a quick check
517 02cab3e7 Michael Hanselmann
      while len(self._children) > self.MAX_CHILDREN:
518 02cab3e7 Michael Hanselmann
        try:
519 02cab3e7 Michael Hanselmann
          # Waiting without a timeout brings us into a potential DoS situation.
520 02cab3e7 Michael Hanselmann
          # As soon as too many children run, we'll not respond to new
521 02cab3e7 Michael Hanselmann
          # requests. The real solution would be to add a timeout for children
522 02cab3e7 Michael Hanselmann
          # and killing them after some time.
523 7c4d6c7b Michael Hanselmann
          pid, _ = os.waitpid(0, 0)
524 02cab3e7 Michael Hanselmann
        except os.error:
525 02cab3e7 Michael Hanselmann
          pid = None
526 02cab3e7 Michael Hanselmann
        if pid and pid in self._children:
527 02cab3e7 Michael Hanselmann
          self._children.remove(pid)
528 02cab3e7 Michael Hanselmann
529 02cab3e7 Michael Hanselmann
    for child in self._children:
530 02cab3e7 Michael Hanselmann
      try:
531 1122eb25 Iustin Pop
        pid, _ = os.waitpid(child, os.WNOHANG)
532 02cab3e7 Michael Hanselmann
      except os.error:
533 02cab3e7 Michael Hanselmann
        pid = None
534 02cab3e7 Michael Hanselmann
      if pid and pid in self._children:
535 02cab3e7 Michael Hanselmann
        self._children.remove(pid)
536 02cab3e7 Michael Hanselmann
537 02cab3e7 Michael Hanselmann
  def _IncomingConnection(self):
538 02cab3e7 Michael Hanselmann
    """Called for each incoming connection
539 02cab3e7 Michael Hanselmann

540 02cab3e7 Michael Hanselmann
    """
541 b459a848 Andrea Spadaccini
    # pylint: disable=W0212
542 02cab3e7 Michael Hanselmann
    (connection, client_addr) = self.socket.accept()
543 02cab3e7 Michael Hanselmann
544 02cab3e7 Michael Hanselmann
    self._CollectChildren(False)
545 02cab3e7 Michael Hanselmann
546 02cab3e7 Michael Hanselmann
    pid = os.fork()
547 02cab3e7 Michael Hanselmann
    if pid == 0:
548 02cab3e7 Michael Hanselmann
      # Child process
549 02cab3e7 Michael Hanselmann
      try:
550 bcb1a39e Michael Hanselmann
        # The client shouldn't keep the listening socket open. If the parent
551 bcb1a39e Michael Hanselmann
        # process is restarted, it would fail when there's already something
552 bcb1a39e Michael Hanselmann
        # listening (in this case its own child from a previous run) on the
553 bcb1a39e Michael Hanselmann
        # same port.
554 bcb1a39e Michael Hanselmann
        try:
555 bcb1a39e Michael Hanselmann
          self.socket.close()
556 bcb1a39e Michael Hanselmann
        except socket.error:
557 bcb1a39e Michael Hanselmann
          pass
558 bcb1a39e Michael Hanselmann
        self.socket = None
559 bcb1a39e Michael Hanselmann
560 82869978 Michael Hanselmann
        # In case the handler code uses temporary files
561 82869978 Michael Hanselmann
        utils.ResetTempfileModule()
562 82869978 Michael Hanselmann
563 1f8588f6 Iustin Pop
        self.request_executor(self, connection, client_addr)
564 b459a848 Andrea Spadaccini
      except Exception: # pylint: disable=W0703
565 02cab3e7 Michael Hanselmann
        logging.exception("Error while handling request from %s:%s",
566 02cab3e7 Michael Hanselmann
                          client_addr[0], client_addr[1])
567 02cab3e7 Michael Hanselmann
        os._exit(1)
568 02cab3e7 Michael Hanselmann
      os._exit(0)
569 02cab3e7 Michael Hanselmann
    else:
570 02cab3e7 Michael Hanselmann
      self._children.append(pid)
571 02cab3e7 Michael Hanselmann
572 f8bd7df3 Michael Hanselmann
  def PreHandleRequest(self, req):
573 f8bd7df3 Michael Hanselmann
    """Called before handling a request.
574 f8bd7df3 Michael Hanselmann

575 5bbd3f7f Michael Hanselmann
    Can be overridden by a subclass.
576 f8bd7df3 Michael Hanselmann

577 f8bd7df3 Michael Hanselmann
    """
578 f8bd7df3 Michael Hanselmann
579 02cab3e7 Michael Hanselmann
  def HandleRequest(self, req):
580 02cab3e7 Michael Hanselmann
    """Handles a request.
581 02cab3e7 Michael Hanselmann

582 5bbd3f7f Michael Hanselmann
    Must be overridden by subclass.
583 02cab3e7 Michael Hanselmann

584 02cab3e7 Michael Hanselmann
    """
585 02cab3e7 Michael Hanselmann
    raise NotImplementedError()