"""Simple XML-RPC Server.

This module can be used to create simple XML-RPC servers

by creating a server and either installing functions, a

class instance, or by extending the SimpleXMLRPCServer

class.

It can also be used to handle XML-RPC requests in a CGI

environment using CGIXMLRPCRequestHandler.

A list of possible usage patterns follows:

1. Install functions:

server = SimpleXMLRPCServer(("localhost", 8000))

server.register_function(pow)

server.register_function(lambda x,y: x+y, 'add')

server.serve_forever()

2. Install an instance:

class MyFuncs:

    def __init__(self):

        # make all of the string functions available through

        # string.func_name

        import string

        self.string = string

    def _listMethods(self):

        # implement this method so that system.listMethods

        # knows to advertise the strings methods

        return list_public_methods(self) + \

                ['string.' + method for method in list_public_methods(self.string)]

    def pow(self, x, y): return pow(x, y)

    def add(self, x, y) : return x + y

server = SimpleXMLRPCServer(("localhost", 8000))

server.register_introspection_functions()

server.register_instance(MyFuncs())

server.serve_forever()

3. Install an instance with custom dispatch method:

class Math:

    def _listMethods(self):

        # this method must be present for system.listMethods

        # to work

        return ['add', 'pow']

    def _methodHelp(self, method):

        # this method must be present for system.methodHelp

        # to work

        if method == 'add':

            return "add(2,3) => 5"

        elif method == 'pow':

            return "pow(x, y[, z]) => number"

        else:

            # By convention, return empty

            # string if no help is available

            return ""

    def _dispatch(self, method, params):

        if method == 'pow':

            return pow(*params)

        elif method == 'add':

            return params[0] + params[1]

        else:

            raise 'bad method'

server = SimpleXMLRPCServer(("localhost", 8000))

server.register_introspection_functions()

server.register_instance(Math())

server.serve_forever()

4. Subclass SimpleXMLRPCServer:

class MathServer(SimpleXMLRPCServer):

    def _dispatch(self, method, params):

        try:

            # We are forcing the 'export_' prefix on methods that are

            # callable through XML-RPC to prevent potential security

            # problems

            func = getattr(self, 'export_' + method)

        except AttributeError:

            raise Exception('method "%s" is not supported' % method)

        else:

            return func(*params)

    def export_add(self, x, y):

        return x + y

server = MathServer(("localhost", 8000))

server.serve_forever()

5. CGI script:

server = CGIXMLRPCRequestHandler()

server.register_function(pow)

server.handle_request()

"""

# Written by Brian Quinlan (brian@sweetapp.com).

# Based on code written by Fredrik Lundh.

import xmlrpclib

from xmlrpclib import Fault

import SocketServer

import BaseHTTPServer

import sys

import os

import traceback

try:

    import fcntl

except ImportError:

    fcntl = None

def resolve_dotted_attribute(obj, attr, allow_dotted_names=True):

    """resolve_dotted_attribute(a, 'b.c.d') => a.b.c.d

    Resolves a dotted attribute name to an object.  Raises

    an AttributeError if any attribute in the chain starts with a '_'.

    If the optional allow_dotted_names argument is false, dots are not

    supported and this function operates similar to getattr(obj, attr).

    """

    if allow_dotted_names:

        attrs = attr.split('.')

    else:

        attrs = [attr]

    for i in attrs:

        if i.startswith('_'):

            raise AttributeError(

                'attempt to access private attribute "%s"' % i

                )

        else:

            obj = getattr(obj,i)

    return obj

def list_public_methods(obj):

    """Returns a list of attribute strings, found in the specified

    object, which represent callable attributes"""

    return [member for member in dir(obj)

                if not member.startswith('_') and

                    hasattr(getattr(obj, member), '__call__')]

def remove_duplicates(lst):

    """remove_duplicates([2,2,2,1,3,3]) => [3,1,2]

    Returns a copy of a list without duplicates. Every list

    item must be hashable and the order of the items in the

    resulting list is not defined.

    """

    u = {}

    for x in lst:

        u[x] = 1

    return u.keys()

class SimpleXMLRPCDispatcher:

    """Mix-in class that dispatches XML-RPC requests.

    This class is used to register XML-RPC method handlers

    and then to dispatch them. There should never be any

    reason to instantiate this class directly.

    """

    def __init__(self, allow_none, encoding):

        self.funcs = {}

        self.instance = None

        self.allow_none = allow_none

        self.encoding = encoding

    def register_instance(self, instance, allow_dotted_names=False):

        """Registers an instance to respond to XML-RPC requests.

        Only one instance can be installed at a time.

        If the registered instance has a _dispatch method then that

        method will be called with the name of the XML-RPC method and

        its parameters as a tuple

        e.g. instance._dispatch('add',(2,3))

        If the registered instance does not have a _dispatch method

        then the instance will be searched to find a matching method

        and, if found, will be called. Methods beginning with an '_'

        are considered private and will not be called by

        SimpleXMLRPCServer.

        If a registered function matches a XML-RPC request, then it

        will be called instead of the registered instance.

        If the optional allow_dotted_names argument is true and the

        instance does not have a _dispatch method, method names

        containing dots are supported and resolved, as long as none of

        the name segments start with an '_'.

            *** SECURITY WARNING: ***

            Enabling the allow_dotted_names options allows intruders

            to access your module's global variables and may allow

            intruders to execute arbitrary code on your machine.  Only

            use this option on a secure, closed network.

        """

        self.instance = instance

        self.allow_dotted_names = allow_dotted_names

    def register_function(self, function, name = None):

        """Registers a function to respond to XML-RPC requests.

        The optional name argument can be used to set a Unicode name

        for the function.

        """

        if name is None:

            name = function.__name__

        self.funcs[name] = function

    def register_introspection_functions(self):

        """Registers the XML-RPC introspection methods in the system

        namespace.

        see http://xmlrpc.usefulinc.com/doc/reserved.html

        """

        self.funcs.update({'system.listMethods' : self.system_listMethods,

                      'system.methodSignature' : self.system_methodSignature,

                      'system.methodHelp' : self.system_methodHelp})

    def register_multicall_functions(self):

        """Registers the XML-RPC multicall method in the system

        namespace.

        see http://www.xmlrpc.com/discuss/msgReader$1208"""

        self.funcs.update({'system.multicall' : self.system_multicall})

    def _marshaled_dispatch(self, data, dispatch_method = None):

        """Dispatches an XML-RPC method from marshalled (XML) data.

        XML-RPC methods are dispatched from the marshalled (XML) data

        using the _dispatch method and the result is returned as

        marshalled data. For backwards compatibility, a dispatch

        function can be provided as an argument (see comment in

        SimpleXMLRPCRequestHandler.do_POST) but overriding the

        existing method through subclassing is the prefered means

        of changing method dispatch behavior.

        """

        try:

            params, method = xmlrpclib.loads(data)

            # generate response

            if dispatch_method is not None:

                response = dispatch_method(method, params)

            else:

                response = self._dispatch(method, params)

            # wrap response in a singleton tuple

            response = (response,)

            response = xmlrpclib.dumps(response, methodresponse=1,

                                       allow_none=self.allow_none, encoding=self.encoding)

        except Fault, fault:

            response = xmlrpclib.dumps(fault, allow_none=self.allow_none,

                                       encoding=self.encoding)

        except:

            # report exception back to server

            exc_type, exc_value, exc_tb = sys.exc_info()

            response = xmlrpclib.dumps(

                xmlrpclib.Fault(1, "%s:%s" % (exc_type, exc_value)),

                encoding=self.encoding, allow_none=self.allow_none,

                )

        return response

    def system_listMethods(self):

        """system.listMethods() => ['add', 'subtract', 'multiple']

        Returns a list of the methods supported by the server."""

        methods = self.funcs.keys()

        if self.instance is not None:

            # Instance can implement _listMethod to return a list of

            # methods

            if hasattr(self.instance, '_listMethods'):

                methods = remove_duplicates(

                        methods + self.instance._listMethods()

                    )

            # if the instance has a _dispatch method then we

            # don't have enough information to provide a list

            # of methods

            elif not hasattr(self.instance, '_dispatch'):

                methods = remove_duplicates(

                        methods + list_public_methods(self.instance)

                    )

        methods.sort()

        return methods

    def system_methodSignature(self, method_name):

        """system.methodSignature('add') => [double, int, int]

        Returns a list describing the signature of the method. In the

        above example, the add method takes two integers as arguments

        and returns a double result.

        This server does NOT support system.methodSignature."""

        # See http://xmlrpc.usefulinc.com/doc/sysmethodsig.html

        return 'signatures not supported'

    def system_methodHelp(self, method_name):

        """system.methodHelp('add') => "Adds two integers together"

        Returns a string containing documentation for the specified method."""

        method = None

        if method_name in self.funcs:

            method = self.funcs[method_name]

        elif self.instance is not None:

            # Instance can implement _methodHelp to return help for a method

            if hasattr(self.instance, '_methodHelp'):

                return self.instance._methodHelp(method_name)

            # if the instance has a _dispatch method then we

            # don't have enough information to provide help

            elif not hasattr(self.instance, '_dispatch'):

                try:

                    method = resolve_dotted_attribute(

                                self.instance,

                                method_name,

                                self.allow_dotted_names

                                )

                except AttributeError:

                    pass

        # Note that we aren't checking that the method actually

        # be a callable object of some kind

        if method is None:

            return ""

        else:

            import pydoc

            return pydoc.getdoc(method)

    def system_multicall(self, call_list):

        """system.multicall([{'methodName': 'add', 'params': [2, 2]}, ...]) => \

[[4], ...]

        Allows the caller to package multiple XML-RPC calls into a single

        request.

        See http://www.xmlrpc.com/discuss/msgReader$1208

        """

        results = []

        for call in call_list:

            method_name = call['methodName']

            params = call['params']

            try:

                # XXX A marshalling error in any response will fail the entire

                # multicall. If someone cares they should fix this.

                results.append([self._dispatch(method_name, params)])

            except Fault, fault:

                results.append(

                    {'faultCode' : fault.faultCode,

                     'faultString' : fault.faultString}

                    )

            except:

                exc_type, exc_value, exc_tb = sys.exc_info()

                results.append(

                    {'faultCode' : 1,

                     'faultString' : "%s:%s" % (exc_type, exc_value)}

                    )

        return results

    def _dispatch(self, method, params):

        """Dispatches the XML-RPC method.

        XML-RPC calls are forwarded to a registered function that

        matches the called XML-RPC method name. If no such function

        exists then the call is forwarded to the registered instance,

        if available.

        If the registered instance has a _dispatch method then that

        method will be called with the name of the XML-RPC method and

        its parameters as a tuple

        e.g. instance._dispatch('add',(2,3))

        If the registered instance does not have a _dispatch method

        then the instance will be searched to find a matching method

        and, if found, will be called.

        Methods beginning with an '_' are considered private and will

        not be called.

        """

        func = None

        try:

            # check to see if a matching function has been registered

            func = self.funcs[method]

        except KeyError:

            if self.instance is not None:

                # check for a _dispatch method

                if hasattr(self.instance, '_dispatch'):

                    return self.instance._dispatch(method, params)

                else:

                    # call instance method directly

                    try:

                        func = resolve_dotted_attribute(

                            self.instance,

                            method,

                            self.allow_dotted_names

                            )

                    except AttributeError:

                        pass

        if func is not None:

            return func(*params)

        else:

            raise Exception('method "%s" is not supported' % method)

class SimpleXMLRPCRequestHandler(BaseHTTPServer.BaseHTTPRequestHandler):

    """Simple XML-RPC request handler class.

    Handles all HTTP POST requests and attempts to decode them as

    XML-RPC requests.

    """

    # Class attribute listing the accessible path components;

    # paths not on this list will result in a 404 error.

    rpc_paths = ('/', '/RPC2')

    def is_rpc_path_valid(self):

        if self.rpc_paths:

            return self.path in self.rpc_paths

        else:

            # If .rpc_paths is empty, just assume all paths are legal

            return True

    def do_POST(self):

        """Handles the HTTP POST request.

        Attempts to interpret all HTTP POST requests as XML-RPC calls,

        which are forwarded to the server's _dispatch method for handling.

        """

        # Check that the path is legal

        if not self.is_rpc_path_valid():

            self.report_404()

            return

        try:

            # Get arguments by reading body of request.

            # We read this in chunks to avoid straining

            # socket.read(); around the 10 or 15Mb mark, some platforms

            # begin to have problems (bug #792570).

            max_chunk_size = 10*1024*1024

            size_remaining = int(self.headers["content-length"])

            L = []

            while size_remaining:

                chunk_size = min(size_remaining, max_chunk_size)

                L.append(self.rfile.read(chunk_size))

                size_remaining -= len(L[-1])

            data = ''.join(L)

            # In previous versions of SimpleXMLRPCServer, _dispatch

            # could be overridden in this class, instead of in

            # SimpleXMLRPCDispatcher. To maintain backwards compatibility,

            # check to see if a subclass implements _dispatch and dispatch

            # using that method if present.

            response = self.server._marshaled_dispatch(

                    data, getattr(self, '_dispatch', None)

                )

        except Exception, e: # This should only happen if the module is buggy

            # internal error, report as HTTP server error

            self.send_response(500)

            # Send information about the exception if requested

            if hasattr(self.server, '_send_traceback_header') and \

                    self.server._send_traceback_header:

                self.send_header("X-exception", str(e))

                self.send_header("X-traceback", traceback.format_exc())

            self.end_headers()

        else:

            # got a valid XML RPC response

            self.send_response(200)

            self.send_header("Content-type", "text/xml")

            self.send_header("Content-length", str(len(response)))

            self.end_headers()

            self.wfile.write(response)

            # shut down the connection

            self.wfile.flush()

            self.connection.shutdown(1)

    def report_404 (self):

            # Report a 404 error

        self.send_response(404)

        response = 'No such page'

        self.send_header("Content-type", "text/plain")

        self.send_header("Content-length", str(len(response)))

        self.end_headers()

        self.wfile.write(response)

        # shut down the connection

        self.wfile.flush()

        self.connection.shutdown(1)

    def log_request(self, code='-', size='-'):

        """Selectively log an accepted request."""

        if self.server.logRequests:

            BaseHTTPServer.BaseHTTPRequestHandler.log_request(self, code, size)

class SimpleXMLRPCServer(SocketServer.TCPServer,

                         SimpleXMLRPCDispatcher):

    """Simple XML-RPC server.

    Simple XML-RPC server that allows functions and a single instance

    to be installed to handle requests. The default implementation

    attempts to dispatch XML-RPC calls to the functions or instance

    installed in the server. Override the _dispatch method inhereted

    from SimpleXMLRPCDispatcher to change this behavior.

    """

    allow_reuse_address = True

    # Warning: this is for debugging purposes only! Never set this to True in