Viewing file:  SimpleXMLRPCServer.py (18.11 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
"""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
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
callable(getattr(obj, member))]
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):
self.funcs = {}
self.instance = None
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.
"""
params, method = xmlrpclib.loads(data)
# generate response
try:
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)
except Fault, fault:
response = xmlrpclib.dumps(fault)
except:
# report exception back to server
response = xmlrpclib.dumps(
xmlrpclib.Fault(1, "%s:%s" % (sys.exc_type, sys.exc_value))
)
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 self.funcs.has_key(method_name):
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:
results.append(
{'faultCode' : 1,
'faultString' : "%s:%s" % (sys.exc_type, sys.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.
"""
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.
"""
try:
# get arguments
data = self.rfile.read(int(self.headers["content-length"]))
# 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: # This should only happen if the module is buggy
# internal error, report as HTTP server error
self.send_response(500)
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 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.
"""
def __init__(self, addr, requestHandler=SimpleXMLRPCRequestHandler,
logRequests=1):
self.logRequests = logRequests
SimpleXMLRPCDispatcher.__init__(self)
SocketServer.TCPServer.__init__(self, addr, requestHandler)
class CGIXMLRPCRequestHandler(SimpleXMLRPCDispatcher):
"""Simple handler for XML-RPC data passed through CGI."""
def __init__(self):
SimpleXMLRPCDispatcher.__init__(self)
def handle_xmlrpc(self, request_text):
"""Handle a single XML-RPC request"""
response = self._marshaled_dispatch(request_text)
print 'Content-Type: text/xml'
print 'Content-Length: %d' % len(response)
print
sys.stdout.write(response)
def handle_get(self):
"""Handle a single HTTP GET request.
Default implementation indicates an error because
XML-RPC uses the POST method.
"""
code = 400
message, explain = \
BaseHTTPServer.BaseHTTPRequestHandler.responses[code]
response = BaseHTTPServer.DEFAULT_ERROR_MESSAGE % \
{
'code' : code,
'message' : message,
'explain' : explain
}
print 'Status: %d %s' % (code, message)
print 'Content-Type: text/html'
print 'Content-Length: %d' % len(response)
print
sys.stdout.write(response)
def handle_request(self, request_text = None):
"""Handle a single XML-RPC request passed through a CGI post method.
If no XML data is given then it is read from stdin. The resulting
XML-RPC response is printed to stdout along with the correct HTTP
headers.
"""
if request_text is None and \
os.environ.get('REQUEST_METHOD', None) == 'GET':
self.handle_get()
else:
# POST data is normally available through stdin
if request_text is None:
request_text = sys.stdin.read()
self.handle_xmlrpc(request_text)
if __name__ == '__main__':
server = SimpleXMLRPCServer(("localhost", 8000))
server.register_function(pow)
server.register_function(lambda x,y: x+y, 'add')
server.serve_forever()
|