"""XML-RPC Servers.
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.
The Doc* classes can be used to create XML-RPC servers that
serve pydoc-style documentation in response to HTTP
GET requests. This documentation is dynamically generated
based on the functions and methods registered with the
server.
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 sys functions available through sys.func_name
import sys
self.sys = sys
def _listMethods(self):
# implement this method so that system.listMethods
# knows to advertise the sys methods
return list_public_methods(self) + \
['sys.' + method for method in list_public_methods(self.sys)]
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 ValueError('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.
from xmlrpc.client import Fault, dumps, loads
from http.server import BaseHTTPRequestHandler
import http.server
import socketserver
import sys
import os
import re
import pydoc
import inspect
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__')]
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=False, encoding=None):
self.funcs = {}
self.instance = None
self.allow_none = allow_none
self.encoding = encoding or 'utf-8'
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 = 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 = dumps(response, methodresponse=1,
allow_none=self.allow_none, encoding=self.encoding)
except Fault as fault:
response = 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 = dumps(
Fault(1, "%s:%s" % (exc_type, exc_value)),
encoding=self.encoding, allow_none=self.allow_none,
)
return response.encode(self.encoding)
def system_listMethods(self):
"""system.listMethods() => ['add', 'subtract', 'multiple']
Returns a list of the methods supported by the server."""
methods = set(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 |= set(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 |= set(list_public_methods(self.instance))
return sorted(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 as 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(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 = b''.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 as 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))
trace = traceback.format_exc()
trace = str(trace.encode('ASCII', 'backslashreplace'), 'ASCII')
self.send_header("X-traceback", trace)
self.end_headers()
else:
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 = b'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:
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
# production code, as will be sending out sensitive information (exception
# and stack trace details) when exceptions are raised inside
# SimpleXMLRPCRequestHandler.do_POST
_send_traceback_header = False
def __init__(self, addr, requestHandler=SimpleXMLRPCRequestHandler,
logRequests=True, allow_none=False, encoding=None, bind_and_activate=True):
self.logRequests = logRequests
SimpleXMLRPCDispatcher.__init__(self, allow_none, encoding)
socketserver.TCPServer.__init__(self, addr, requestHandler, bind_and_activate)
# [Bug #1222790] If possible, set close-on-exec flag; if a
# method spawns a subprocess, the subprocess shouldn't have
# the listening socket open.
if fcntl is not None and hasattr(fcntl, 'FD_CLOEXEC'):
flags = fcntl.fcntl(self.fileno(), fcntl.F_GETFD)
flags |= fcntl.FD_CLOEXEC
fcntl.fcntl(self.fileno(), fcntl.F_SETFD, flags)
class CGIXMLRPCRequestHandler(SimpleXMLRPCDispatcher):
"""Simple handler for XML-RPC data passed through CGI."""
def __init__(self, allow_none=False, encoding=None):
SimpleXMLRPCDispatcher.__init__(self, allow_none, encoding)
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.flush()
sys.stdout.buffer.write(response)
sys.stdout.buffer.flush()
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 = BaseHTTPRequestHandler.responses[code]
response = http.server.DEFAULT_ERROR_MESSAGE % \
{
'code' : code,
'message' : message,
'explain' : explain
}
response = response.encode('utf-8')
print('Status: %d %s' % (code, message))
print('Content-Type: %s' % http.server.DEFAULT_ERROR_CONTENT_TYPE)
print('Content-Length: %d' % len(response))
print()
sys.stdout.flush()
sys.stdout.buffer.write(response)
sys.stdout.buffer.flush()
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
try:
length = int(os.environ.get('CONTENT_LENGTH', None))
except (ValueError, TypeError):
length = -1
if request_text is None:
request_text = sys.stdin.read(length)
self.handle_xmlrpc(request_text)
# -----------------------------------------------------------------------------
# Self documenting XML-RPC Server.
class ServerHTMLDoc(pydoc.HTMLDoc):
"""Class used to generate pydoc HTML document for a server"""
def markup(self, text, escape=None, funcs={}, classes={}, methods={}):
"""Mark up some plain text, given a context of symbols to look for.
Each context dictionary maps object names to anchor names."""
escape = escape or self.escape
results = []
here = 0
# XXX Note that this regular expression does not allow for the
# hyperlinking of arbitrary strings being used as method
# names. Only methods with names consisting of word characters
# and '.'s are hyperlinked.
pattern = re.compile(r'\b((http|ftp)://\S+[\w/]|'
r'RFC[- ]?(\d+)|'
r'PEP[- ]?(\d+)|'
r'(self\.)?((?:\w|\.)+))\b')
while 1:
match = pattern.search(text, here)
if not match: break
start, end = match.span()
results.append(escape(text[here:start]))
all, scheme, rfc, pep, selfdot, name = match.groups()
if scheme:
url = escape(all).replace('"', '"')
results.append('%s' % (url, url))
elif rfc:
url = 'http://www.rfc-editor.org/rfc/rfc%d.txt' % int(rfc)
results.append('%s' % (url, escape(all)))
elif pep:
url = 'http://www.python.org/dev/peps/pep-%04d/' % int(pep)
results.append('%s' % (url, escape(all)))
elif text[end:end+1] == '(':
results.append(self.namelink(name, methods, funcs, classes))
elif selfdot:
results.append('self.%s' % name)
else:
results.append(self.namelink(name, classes))
here = end
results.append(escape(text[here:]))
return ''.join(results)
def docroutine(self, object, name, mod=None,
funcs={}, classes={}, methods={}, cl=None):
"""Produce HTML documentation for a function or method object."""
anchor = (cl and cl.__name__ or '') + '-' + name
note = ''
title = '%s' % (
self.escape(anchor), self.escape(name))
if inspect.ismethod(object):
args, varargs, varkw, defaults = inspect.getargspec(object)
# exclude the argument bound to the instance, it will be
# confusing to the non-Python user
argspec = inspect.formatargspec (
args[1:],
varargs,
varkw,
defaults,
formatvalue=self.formatvalue
)
elif inspect.isfunction(object):
args, varargs, varkw, defaults = inspect.getargspec(object)
argspec = inspect.formatargspec(
args, varargs, varkw, defaults, formatvalue=self.formatvalue)
else:
argspec = '(...)'
if isinstance(object, tuple):
argspec = object[0] or argspec
docstring = object[1] or ""
else:
docstring = pydoc.getdoc(object)
decl = title + argspec + (note and self.grey(
'%s' % note))
doc = self.markup(
docstring, self.preformat, funcs, classes, methods)
doc = doc and '%s' % doc
return '- %s
%s
\n' % (decl, doc)
def docserver(self, server_name, package_documentation, methods):
"""Produce HTML documentation for an XML-RPC server."""
fdict = {}
for key, value in methods.items():
fdict[key] = '#-' + key
fdict[value] = fdict[key]
server_name = self.escape(server_name)
head = '%s' % server_name
result = self.heading(head, '#ffffff', '#7799ee')
doc = self.markup(package_documentation, self.preformat, fdict)
doc = doc and '%s' % doc
result = result + '%s
\n' % doc
contents = []
method_items = sorted(methods.items())
for key, value in method_items:
contents.append(self.docroutine(value, key, funcs=fdict))
result = result + self.bigsection(
'Methods', '#ffffff', '#eeaa77', ''.join(contents))
return result
class XMLRPCDocGenerator:
"""Generates documentation for an XML-RPC server.
This class is designed as mix-in and should not
be constructed directly.
"""
def __init__(self):
# setup variables used for HTML documentation
self.server_name = 'XML-RPC Server Documentation'
self.server_documentation = \
"This server exports the following methods through the XML-RPC "\
"protocol."
self.server_title = 'XML-RPC Server Documentation'
def set_server_title(self, server_title):
"""Set the HTML title of the generated server documentation"""
self.server_title = server_title
def set_server_name(self, server_name):
"""Set the name of the generated HTML server documentation"""
self.server_name = server_name
def set_server_documentation(self, server_documentation):
"""Set the documentation string for the entire server."""
self.server_documentation = server_documentation
def generate_html_documentation(self):
"""generate_html_documentation() => html documentation for the server
Generates HTML documentation for the server using introspection for
installed functions and instances that do not implement the
_dispatch method. Alternatively, instances can choose to implement
the _get_method_argstring(method_name) method to provide the
argument string used in the documentation and the
_methodHelp(method_name) method to provide the help text used
in the documentation."""
methods = {}
for method_name in self.system_listMethods():
if method_name in self.funcs:
method = self.funcs[method_name]
elif self.instance is not None:
method_info = [None, None] # argspec, documentation
if hasattr(self.instance, '_get_method_argstring'):
method_info[0] = self.instance._get_method_argstring(method_name)
if hasattr(self.instance, '_methodHelp'):
method_info[1] = self.instance._methodHelp(method_name)
method_info = tuple(method_info)
if method_info != (None, None):
method = method_info
elif not hasattr(self.instance, '_dispatch'):
try:
method = resolve_dotted_attribute(
self.instance,
method_name
)
except AttributeError:
method = method_info
else:
method = method_info
else:
assert 0, "Could not find method in self.functions and no "\
"instance installed"
methods[method_name] = method
documenter = ServerHTMLDoc()
documentation = documenter.docserver(
self.server_name,
self.server_documentation,
methods
)
return documenter.page(self.server_title, documentation)
class DocXMLRPCRequestHandler(SimpleXMLRPCRequestHandler):
"""XML-RPC and documentation request handler class.
Handles all HTTP POST requests and attempts to decode them as
XML-RPC requests.
Handles all HTTP GET requests and interprets them as requests
for documentation.
"""
def do_GET(self):
"""Handles the HTTP GET request.
Interpret all HTTP GET requests as requests for server
documentation.
"""
# Check that the path is legal
if not self.is_rpc_path_valid():
self.report_404()
return
response = self.server.generate_html_documentation().encode('utf-8')
self.send_response(200)
self.send_header("Content-type", "text/html")
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)
class DocXMLRPCServer( SimpleXMLRPCServer,
XMLRPCDocGenerator):
"""XML-RPC and HTML documentation server.
Adds the ability to serve server documentation to the capabilities
of SimpleXMLRPCServer.
"""
def __init__(self, addr, requestHandler=DocXMLRPCRequestHandler,
logRequests=True, allow_none=False, encoding=None,
bind_and_activate=True):
SimpleXMLRPCServer.__init__(self, addr, requestHandler, logRequests,
allow_none, encoding, bind_and_activate)
XMLRPCDocGenerator.__init__(self)
class DocCGIXMLRPCRequestHandler( CGIXMLRPCRequestHandler,
XMLRPCDocGenerator):
"""Handler for XML-RPC data and documentation requests passed through
CGI"""
def handle_get(self):
"""Handles the HTTP GET request.
Interpret all HTTP GET requests as requests for server
documentation.
"""
response = self.generate_html_documentation().encode('utf-8')
print('Content-Type: text/html')
print('Content-Length: %d' % len(response))
print()
sys.stdout.flush()
sys.stdout.buffer.write(response)
sys.stdout.buffer.flush()
def __init__(self):
CGIXMLRPCRequestHandler.__init__(self)
XMLRPCDocGenerator.__init__(self)
if __name__ == '__main__':
print('Running XML-RPC server on port 8000')
server = SimpleXMLRPCServer(("localhost", 8000))
server.register_function(pow)
server.register_function(lambda x,y: x+y, 'add')
server.serve_forever()