/lib/http.py - snf-ganeti - Greek Research and Technology Network's projects

| Branch: | Tag: | Revision:

root / lib / http.py @ 686d7433

History | View | Annotate | Download (21.7 kB)

+      #
+      #
       # This program is free software; you can redistribute it and/or modify
       # it under the terms of the GNU General Public License as published by
       # the Free Software Foundation; either version 2 of the License, or
       # (at your option) any later version.
+      #
       # This program is distributed in the hope that it will be useful, but
       # WITHOUT ANY WARRANTY; without even the implied warranty of
       # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
       # General Public License for more details.
+      #
       # You should have received a copy of the GNU General Public License
       # along with this program; if not, write to the Free Software
       # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
       # 02110-1301, USA.
       """HTTP server module.
       """
       import BaseHTTPServer
       import cgi
       import logging
       import mimetools
       import OpenSSL
       import os
       import select
       import socket
       import sys
       import time
       import signal
       from ganeti import constants
       from ganeti import logger
       from ganeti import serializer
       WEEKDAYNAME = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
       MONTHNAME = [None,
                    'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
                    'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
       # Default error message
       DEFAULT_ERROR_CONTENT_TYPE = "text/html"
       DEFAULT_ERROR_MESSAGE = """\
       <head>
       <title>Error response</title>
       </head>
       <body>
       <h1>Error response</h1>
       <p>Error code %(code)d.
       <p>Message: %(message)s.
       <p>Error code explanation: %(code)s = %(explain)s.
       </body>
       """
       HTTP_OK = 200
       HTTP_NO_CONTENT = 204
       HTTP_NOT_MODIFIED = 304
       HTTP_0_9 = "HTTP/0.9"
       HTTP_1_0 = "HTTP/1.0"
       HTTP_1_1 = "HTTP/1.1"
       HTTP_GET = "GET"
       HTTP_HEAD = "HEAD"
       class SocketClosed(socket.error):
         pass
       class HTTPException(Exception):
         code = None
         message = None
         def __init__(self, message=None):
           Exception.__init__(self)
           if message is not None:
             self.message = message
       class HTTPBadRequest(HTTPException):
         code = 400
       class HTTPForbidden(HTTPException):
         code = 403
       class HTTPNotFound(HTTPException):
         code = 404
       class HTTPGone(HTTPException):
         code = 410
       class HTTPLengthRequired(HTTPException):
         code = 411
       class HTTPInternalError(HTTPException):
         code = 500
       class HTTPNotImplemented(HTTPException):
         code = 501
       class HTTPServiceUnavailable(HTTPException):
         code = 503
       class HTTPVersionNotSupported(HTTPException):
         code = 505
       class ApacheLogfile:
         """Utility class to write HTTP server log files.
         The written format is the "Common Log Format" as defined by Apache:
         http://httpd.apache.org/docs/2.2/mod/mod_log_config.html#examples
         """
         def __init__(self, fd):
           """Constructor for ApacheLogfile class.
           Args:
           - fd: Open file object
           """
           self._fd = fd
         def LogRequest(self, request, format, *args):
           self._fd.write("%s %s %s [%s] %s\n" % (
             # Remote host address
             request.address_string(),
             # RFC1413 identity (identd)
             "-",
             # Remote user
             "-",
             # Request time
             self._FormatCurrentTime(),
             # Message
             format % args,
             ))
           self._fd.flush()
         def _FormatCurrentTime(self):
           """Formats current time in Common Log Format.
           """
           return self._FormatLogTime(time.time())
         def _FormatLogTime(self, seconds):
           """Formats time for Common Log Format.
           All timestamps are logged in the UTC timezone.
           Args:
           - seconds: Time in seconds since the epoch
           """
           (_, month, _, _, _, _, _, _, _) = tm = time.gmtime(seconds)
           format = "%d/" + MONTHNAME[month] + "/%Y:%H:%M:%S +0000"
           return time.strftime(format, tm)
       class HTTPServer(BaseHTTPServer.HTTPServer, object):
         """Class to provide an HTTP/HTTPS server.
         """
         allow_reuse_address = True
         def __init__(self, server_address, HandlerClass, httplog=None,
                      enable_ssl=False, ssl_key=None, ssl_cert=None):
           """Server constructor.
           Args:
             server_address: a touple containing:
               ip: a string with IP address, localhost if empty string
               port: port number, integer
             HandlerClass: HTTPRequestHandler object
             httplog: Access log object
             enable_ssl: Whether to enable SSL
             ssl_key: SSL key file
             ssl_cert: SSL certificate key
           """
           BaseHTTPServer.HTTPServer.__init__(self, server_address, HandlerClass)
           self.httplog = httplog
           if enable_ssl:
             # Set up SSL
             context = OpenSSL.SSL.Context(OpenSSL.SSL.SSLv23_METHOD)
             context.use_privatekey_file(ssl_key)
             context.use_certificate_file(ssl_cert)
             self.socket = OpenSSL.SSL.Connection(context,
                                                  socket.socket(self.address_family,
                                                  self.socket_type))
           else:
             self.socket = socket.socket(self.address_family, self.socket_type)
           self.server_bind()
           self.server_activate()
       class HTTPJsonConverter:
         CONTENT_TYPE = "application/json"
         def Encode(self, data):
           return serializer.DumpJson(data)
         def Decode(self, data):
           return serializer.LoadJson(data)
       class HTTPRequestHandler(BaseHTTPServer.BaseHTTPRequestHandler, object):
         """Request handler class.
         """
         def setup(self):
           """Setup secure read and write file objects.
           """
           self.connection = self.request
           self.rfile = socket._fileobject(self.request, "rb", self.rbufsize)
           self.wfile = socket._fileobject(self.request, "wb", self.wbufsize)
         def handle_one_request(self):
           """Parses a request and calls the handler function.
           """
           self.raw_requestline = None
           try:
             self.raw_requestline = self.rfile.readline()
           except OpenSSL.SSL.Error, ex:
             logger.Error("Error in SSL: %s" % str(ex))
           if not self.raw_requestline:
             self.close_connection = 1
             return
           if not self.parse_request(): # An error code has been sent, just exit
             return
           logging.debug("HTTP request: %s", self.raw_requestline.rstrip("\r\n"))
           try:
             self._ReadPostData()
             result = self.HandleRequest()
             # TODO: Content-type
             encoder = HTTPJsonConverter()
             encoded_result = encoder.Encode(result)
             self.send_response(200)
             self.send_header("Content-Type", encoder.CONTENT_TYPE)
             self.send_header("Content-Length", str(len(encoded_result)))
             self.end_headers()
             self.wfile.write(encoded_result)
           except HTTPException, err:
             self.send_error(err.code, message=err.message)
           except Exception, err:
             self.send_error(HTTPInternalError.code, message=str(err))
           except:
             self.send_error(HTTPInternalError.code, message="Unknown error")
         def _ReadPostData(self):
           if self.command.upper() not in ("POST", "PUT"):
             self.post_data = None
             return
           # TODO: Decide what to do when Content-Length header was not sent
           try:
             content_length = int(self.headers.get('Content-Length', 0))
           except ValueError:
             raise HTTPBadRequest("No Content-Length header or invalid format")
           try:
             data = self.rfile.read(content_length)
           except socket.error, err:
             logger.Error("Socket error while reading: %s" % str(err))
             return
           # TODO: Content-type, error handling
           self.post_data = HTTPJsonConverter().Decode(data)
           logging.debug("HTTP POST data: %s", self.post_data)
         def HandleRequest(self):
           """Handles a request.
           """
           raise NotImplementedError()
         def log_message(self, format, *args):
           """Log an arbitrary message.
           This is used by all other logging functions.
           The first argument, FORMAT, is a format string for the
           message to be logged.  If the format string contains
           any % escapes requiring parameters, they should be
           specified as subsequent arguments (it's just like
           printf!).
           """
           logging.debug("Handled request: %s", format % args)
           if self.server.httplog:
             self.server.httplog.LogRequest(self, format, *args)
       class _HttpConnectionHandler(object):
         """Implements server side of HTTP
         This class implements the server side of HTTP. It's based on code of Python's
         BaseHTTPServer, from both version 2.4 and 3k. It does not support non-ASCII
         character encodings. Keep-alive connections are not supported.
         """
         # String for "Server" header
         server_version = "Ganeti %s" % constants.RELEASE_VERSION
         # The default request version.  This only affects responses up until
         # the point where the request line is parsed, so it mainly decides what
         # the client gets back when sending a malformed request line.
         # Most web servers default to HTTP 0.9, i.e. don't send a status line.
         default_request_version = HTTP_0_9
         # Error message settings
         error_message_format = DEFAULT_ERROR_MESSAGE
         error_content_type = DEFAULT_ERROR_CONTENT_TYPE
         responses = BaseHTTPServer.BaseHTTPRequestHandler.responses
         def __init__(self, server, conn, client_addr, fileio_class):
           """Initializes this class.
           Part of the initialization is reading the request and eventual POST/PUT
           data sent by the client.
           """
           self._server = server
           # We default rfile to buffered because otherwise it could be
           # really slow for large data (a getc() call per byte); we make
           # wfile unbuffered because (a) often after a write() we want to
           # read and we need to flush the line; (b) big writes to unbuffered
           # files are typically optimized by stdio even when big reads
           # aren't.
           self.rfile = fileio_class(conn, mode="rb", bufsize=-1)
           self.wfile = fileio_class(conn, mode="wb", bufsize=0)
           self.client_addr = client_addr
           self.request_headers = None
           self.request_method = None
           self.request_path = None
           self.request_requestline = None
           self.request_version = self.default_request_version
           self.response_body = None
           self.response_code = HTTP_OK
           self.response_content_type = None
           self.should_fork = False
           try:
             self._ReadRequest()
             self._ReadPostData()
             self.should_fork = self._server.ForkForRequest(self)
           except HTTPException, err:
             self._SetErrorStatus(err)
         def Close(self):
           if not self.wfile.closed:
             self.wfile.flush()
           self.wfile.close()
           self.rfile.close()
         def _DateTimeHeader(self):
           """Return the current date and time formatted for a message header.
           """
           (year, month, day, hh, mm, ss, wd, _, _) = time.gmtime()
           return ("%s, %02d %3s %4d %02d:%02d:%02d GMT" %
                   (WEEKDAYNAME[wd], day, MONTHNAME[month], year, hh, mm, ss))
         def _SetErrorStatus(self, err):
           """Sets the response code and body from a HTTPException.
           @type err: HTTPException
           @param err: Exception instance
           """
           try:
             (shortmsg, longmsg) = self.responses[err.code]
           except KeyError:
             shortmsg = longmsg = "Unknown"
           if err.message:
             message = err.message
           else:
             message = shortmsg
           values = {
             "code": err.code,
             "message": cgi.escape(message),
             "explain": longmsg,
+            }
           self.response_code = err.code
           self.response_content_type = self.error_content_type
           self.response_body = self.error_message_format % values
         def HandleRequest(self):
           """Handle the actual request.
           Calls the actual handler function and converts exceptions into HTTP errors.
           """
           # Don't do anything if there's already been a problem
           if self.response_code != HTTP_OK:
             return
           assert self.request_method, "Status code %s requires a method" % HTTP_OK
           # Check whether client is still there
           self.rfile.read(0)
           try:
             try:
               result = self._server.HandleRequest(self)
               # TODO: Content-type
               encoder = HTTPJsonConverter()
               body = encoder.Encode(result)
               self.response_content_type = encoder.CONTENT_TYPE
               self.response_body = body
             except (HTTPException, KeyboardInterrupt, SystemExit):
               raise
             except Exception, err:
               logging.exception("Caught exception")
               raise HTTPInternalError(message=str(err))
             except:
               logging.exception("Unknown exception")
               raise HTTPInternalError(message="Unknown error")
           except HTTPException, err:
             self._SetErrorStatus(err)
         def SendResponse(self):
           """Sends response to the client.
           """
           # Check whether client is still there
           self.rfile.read(0)
           logging.info("%s:%s %s %s", self.client_addr[0], self.client_addr[1],
                        self.request_requestline, self.response_code)
           if self.response_code in self.responses:
             response_message = self.responses[self.response_code][0]
           else:
             response_message = ""
           if self.request_version != HTTP_0_9:
             self.wfile.write("%s %d %s\r\n" %
                              (self.request_version, self.response_code,
                               response_message))
             self._SendHeader("Server", self.server_version)
             self._SendHeader("Date", self._DateTimeHeader())
             self._SendHeader("Content-Type", self.response_content_type)
             self._SendHeader("Content-Length", str(len(self.response_body)))
             # We don't support keep-alive at this time
             self._SendHeader("Connection", "close")
             self.wfile.write("\r\n")
           if (self.request_method != HTTP_HEAD and
               self.response_code >= HTTP_OK and
               self.response_code not in (HTTP_NO_CONTENT, HTTP_NOT_MODIFIED)):
             self.wfile.write(self.response_body)
         def _SendHeader(self, name, value):
           if self.request_version != HTTP_0_9:
             self.wfile.write("%s: %s\r\n" % (name, value))
         def _ReadRequest(self):
           """Reads and parses request line
           """
           raw_requestline = self.rfile.readline()
           requestline = raw_requestline
           if requestline[-2:] == '\r\n':
             requestline = requestline[:-2]
           elif requestline[-1:] == '\n':
             requestline = requestline[:-1]
           if not requestline:
             raise HTTPBadRequest("Empty request line")
           self.request_requestline = requestline
           logging.debug("HTTP request: %s", raw_requestline.rstrip("\r\n"))
           words = requestline.split()
           if len(words) == 3:
             [method, path, version] = words
             if version[:5] != 'HTTP/':
               raise HTTPBadRequest("Bad request version (%r)" % version)
             try:
               base_version_number = version.split('/', 1)[1]
               version_number = base_version_number.split(".")
               # RFC 2145 section 3.1 says there can be only one "." and
               #   - major and minor numbers MUST be treated as
               #      separate integers;
               #   - HTTP/2.4 is a lower version than HTTP/2.13, which in
               #      turn is lower than HTTP/12.3;
               #   - Leading zeros MUST be ignored by recipients.
               if len(version_number) != 2:
                 raise HTTPBadRequest("Bad request version (%r)" % version)
               version_number = int(version_number[0]), int(version_number[1])
             except (ValueError, IndexError):
               raise HTTPBadRequest("Bad request version (%r)" % version)
             if version_number >= (2, 0):
               raise HTTPVersionNotSupported("Invalid HTTP Version (%s)" %
                                             base_version_number)
           elif len(words) == 2:
             version = HTTP_0_9
             [method, path] = words
             if method != HTTP_GET:
               raise HTTPBadRequest("Bad HTTP/0.9 request type (%r)" % method)
           else:
             raise HTTPBadRequest("Bad request syntax (%r)" % requestline)
           # Examine the headers and look for a Connection directive
           headers = mimetools.Message(self.rfile, 0)
           self.request_method = method
           self.request_path = path
           self.request_version = version
           self.request_headers = headers
         def _ReadPostData(self):
           """Reads POST/PUT data
           """
           if not self.request_method or self.request_method.upper() not in ("POST", "PUT"):
             self.request_post_data = None
             return
           # TODO: Decide what to do when Content-Length header was not sent
           try:
             content_length = int(self.request_headers.get('Content-Length', 0))
           except ValueError:
             raise HTTPBadRequest("No Content-Length header or invalid format")
           data = self.rfile.read(content_length)
           # TODO: Content-type, error handling
           self.request_post_data = HTTPJsonConverter().Decode(data)
           logging.debug("HTTP POST data: %s", self.request_post_data)
       class HttpServer(object):
         """Generic HTTP server class
         Users of this class must subclass it and override the HandleRequest function.
         Optionally, the ForkForRequest function can be overriden.
         """
         MAX_CHILDREN = 20
         def __init__(self, mainloop, server_address):
           self.mainloop = mainloop
           self.server_address = server_address
           # TODO: SSL support
           self.ssl_cert = None
           self.ssl_key = self.ssl_cert
           sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
           if self.ssl_cert and self.ssl_key:
             ctx = OpenSSL.SSL.Context(OpenSSL.SSL.SSLv23_METHOD)
             ctx.set_options(OpenSSL.SSL.OP_NO_SSLv2)
             ctx.use_certificate_file(self.ssl_cert)
             ctx.use_privatekey_file(self.ssl_key)
             self.socket = OpenSSL.SSL.Connection(ctx, sock)
             self._fileio_class = _SSLFileObject
           else:
             self.socket = sock
             self._fileio_class = socket._fileobject
           # Allow port to be reused
           self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
           self._children = []
           mainloop.RegisterIO(self, self.socket.fileno(), select.POLLIN)
           mainloop.RegisterSignal(self)
         def Start(self):
           self.socket.bind(self.server_address)
           self.socket.listen(5)
         def Stop(self):
           self.socket.close()
         def OnIO(self, fd, condition):
           if condition & select.POLLIN:
             self._IncomingConnection()
         def OnSignal(self, signum):
           if signum == signal.SIGCHLD:
             self._CollectChildren(True)
         def _CollectChildren(self, quick):
           """Checks whether any child processes are done
           @type quick: bool
           @param quick: Whether to only use non-blocking functions
           """
           if not quick:
             # Don't wait for other processes if it should be a quick check
             while len(self._children) > self.MAX_CHILDREN:
               try:
                 pid, status = os.waitpid(0, 0)
               except os.error:
                 pid = None
               if pid and pid in self._children:
                 self._children.remove(pid)
           for child in self._children:
             try:
               pid, status = os.waitpid(child, os.WNOHANG)
             except os.error:
               pid = None
             if pid and pid in self._children:
               self._children.remove(pid)
         def _IncomingConnection(self):
           connection, client_addr = self.socket.accept()
           logging.info("Connection from %s:%s", client_addr[0], client_addr[1])
           try:
             handler = _HttpConnectionHandler(self, connection, client_addr, self._fileio_class)
           except (socket.error, SocketClosed):
             return
           def FinishRequest():
             try:
               try:
                 try:
                   handler.HandleRequest()
                 finally:
                   # Try to send a response
                   handler.SendResponse()
                   handler.Close()
               except SocketClosed:
                 pass
             finally:
               logging.info("Disconnected %s:%s", client_addr[0], client_addr[1])
           # Check whether we should fork or not
           if not handler.should_fork:
             FinishRequest()
             return
           self._CollectChildren(False)
           pid = os.fork()
           if pid == 0:
             # Child process
             try:
               FinishRequest()
             except:
               logging.exception("Error while handling request from %s:%s",
                                 client_addr[0], client_addr[1])
               os._exit(1)
             os._exit(0)
           else:
             self._children.append(pid)
         def HandleRequest(self, req):
           raise NotImplementedError()
         def ForkForRequest(self, req):
           return True
       class _SSLFileObject(object):
         """Wrapper around socket._fileobject
         This wrapper is required to handle OpenSSL exceptions.
         """
         def _RequireOpenSocket(fn):
           def wrapper(self, *args, **kwargs):
             if self.closed:
               raise SocketClosed("Socket is closed")
             return fn(self, *args, **kwargs)
           return wrapper
         def __init__(self, sock, mode='rb', bufsize=-1):
           self._base = socket._fileobject(sock, mode=mode, bufsize=bufsize)
         def _ConnectionLost(self):
           self._base = None
         def _getclosed(self):
           return self._base is None or self._base.closed
         closed = property(_getclosed, doc="True if the file is closed")
         @_RequireOpenSocket
         def close(self):
           return self._base.close()
         @_RequireOpenSocket
         def flush(self):
           return self._base.flush()
         @_RequireOpenSocket
         def fileno(self):
           return self._base.fileno()
         @_RequireOpenSocket
         def read(self, size=-1):
           return self._ReadWrapper(self._base.read, size=size)
         @_RequireOpenSocket
         def readline(self, size=-1):
           return self._ReadWrapper(self._base.readline, size=size)
         def _ReadWrapper(self, fn, *args, **kwargs):
           while True:
             try:
               return fn(*args, **kwargs)
             except OpenSSL.SSL.ZeroReturnError, err:
               self._ConnectionLost()
               return ""
             except OpenSSL.SSL.WantReadError:
               continue
             #except OpenSSL.SSL.WantWriteError:
             # TODO
             except OpenSSL.SSL.SysCallError, (retval, desc):
               if ((retval == -1 and desc == "Unexpected EOF")
                   or retval > 0):
                 self._ConnectionLost()
                 return ""
               logging.exception("Error in OpenSSL")
               self._ConnectionLost()
               raise socket.error(err.args)
             except OpenSSL.SSL.Error, err:
               self._ConnectionLost()
               raise socket.error(err.args)
         @_RequireOpenSocket
         def write(self, data):
           return self._WriteWrapper(self._base.write, data)
         def _WriteWrapper(self, fn, *args, **kwargs):
           while True:
             try:
               return fn(*args, **kwargs)
             except OpenSSL.SSL.ZeroReturnError, err:
               self._ConnectionLost()
               return 0
             except OpenSSL.SSL.WantWriteError:
               continue
             #except OpenSSL.SSL.WantReadError:
             # TODO
             except OpenSSL.SSL.SysCallError, err:
               if err.args[0] == -1 and data == "":
                 # errors when writing empty strings are expected
                 # and can be ignored
                 return 0
               self._ConnectionLost()
               raise socket.error(err.args)
             except OpenSSL.SSL.Error, err:
               self._ConnectionLost()
               raise socket.error(err.args)

Synnefo » snf-ganeti

root / lib / http.py @ 686d7433