# -*- test-case-name: twisted.web2.test.test_server -*-
# Copyright (c) 2001-2004 Twisted Matrix Laboratories.
# See LICENSE for details.
"""This is a web-sever which integrates with the twisted.internet
infrastructure.
"""
# System Imports
import cStringIO as StringIO
import cgi, time, urlparse
from urllib import quote, unquote
from urlparse import urlsplit
import weakref
from zope.interface import implements
# Twisted Imports
from twisted.internet import defer
from twisted.python import log, failure
# Sibling Imports
from twisted.web2 import http, iweb, fileupload, responsecode
from twisted.web2 import http_headers
from twisted.web2.filter.range import rangefilter
from twisted.web2 import error
from twisted.web2 import version as web2_version
from twisted import __version__ as twisted_version
VERSION = "Twisted/%s TwistedWeb/%s" % (twisted_version, web2_version)
_errorMarker = object()
def defaultHeadersFilter(request, response):
if not response.headers.hasHeader('server'):
response.headers.setHeader('server', VERSION)
if not response.headers.hasHeader('date'):
response.headers.setHeader('date', time.time())
return response
defaultHeadersFilter.handleErrors = True
def preconditionfilter(request, response):
if request.method in ("GET", "HEAD"):
http.checkPreconditions(request, response)
return response
def doTrace(request):
request = iweb.IRequest(request)
txt = "%s %s HTTP/%d.%d\r\n" % (request.method, request.uri,
request.clientproto[0], request.clientproto[1])
l=[]
for name, valuelist in request.headers.getAllRawHeaders():
for value in valuelist:
l.append("%s: %s\r\n" % (name, value))
txt += ''.join(l)
return http.Response(
responsecode.OK,
{'content-type': http_headers.MimeType('message', 'http')},
txt)
def parsePOSTData(request):
if request.stream.length == 0:
return defer.succeed(None)
parser = None
ctype = request.headers.getHeader('content-type')
if ctype is None:
return defer.succeed(None)
def updateArgs(data):
args = data
request.args.update(args)
def updateArgsAndFiles(data):
args, files = data
request.args.update(args)
request.files.update(files)
def error(f):
f.trap(fileupload.MimeFormatError)
raise http.HTTPError(responsecode.BAD_REQUEST)
if ctype.mediaType == 'application' and ctype.mediaSubtype == 'x-www-form-urlencoded':
d = fileupload.parse_urlencoded(request.stream)
d.addCallbacks(updateArgs, error)
return d
elif ctype.mediaType == 'multipart' and ctype.mediaSubtype == 'form-data':
boundary = ctype.params.get('boundary')
if boundary is None:
return failure.Failure(fileupload.MimeFormatError("Boundary not specified in Content-Type."))
d = fileupload.parseMultipartFormData(request.stream, boundary)
d.addCallbacks(updateArgsAndFiles, error)
return d
else:
raise http.HTTPError(responsecode.BAD_REQUEST)
class StopTraversal(object):
"""
Indicates to Request._handleSegment that it should stop handling
path segments.
"""
pass
class Request(http.Request):
"""
vars:
site
remoteAddr
scheme
host
port
path
params
querystring
args
files
prepath
postpath
@ivar path: The path only (arguments not included).
@ivar args: All of the arguments, including URL and POST arguments.
@type args: A mapping of strings (the argument names) to lists of values.
i.e., ?foo=bar&foo=baz&quux=spam results in
{'foo': ['bar', 'baz'], 'quux': ['spam']}.
"""
implements(iweb.IRequest)
site = None
_initialprepath = None
responseFilters = [rangefilter, preconditionfilter,
error.defaultErrorHandler, defaultHeadersFilter]
def __init__(self, *args, **kw):
if kw.has_key('site'):
self.site = kw['site']
del kw['site']
if kw.has_key('prepathuri'):
self._initialprepath = kw['prepathuri']
del kw['prepathuri']
# Copy response filters from the class
self.responseFilters = self.responseFilters[:]
self.files = {}
self.resources = []
http.Request.__init__(self, *args, **kw)
def addResponseFilter(self, f, atEnd=False):
if atEnd:
self.responseFilters.append(f)
else:
self.responseFilters.insert(0, f)
def unparseURL(self, scheme=None, host=None, port=None,
path=None, params=None, querystring=None, fragment=None):
"""Turn the request path into a url string. For any pieces of
the url that are not specified, use the value from the
request. The arguments have the same meaning as the same named
attributes of Request."""
if scheme is None: scheme = self.scheme
if host is None: host = self.host
if port is None: port = self.port
if path is None: path = self.path
if params is None: params = self.params
if querystring is None: query = self.querystring
if fragment is None: fragment = ''
if port == http.defaultPortForScheme.get(scheme, 0):
hostport = host
else:
hostport = host + ':' + str(port)
return urlparse.urlunparse((
scheme, hostport, path,
params, querystring, fragment))
def _parseURL(self):
if self.uri[0] == '/':
# Can't use urlparse for request_uri because urlparse
# wants to be given an absolute or relative URI, not just
# an abs_path, and thus gets '//foo' wrong.
self.scheme = self.host = self.path = self.params = self.querystring = ''
if '?' in self.uri:
self.path, self.querystring = self.uri.split('?', 1)
else:
self.path = self.uri
if ';' in self.path:
self.path, self.params = self.path.split(';', 1)
else:
# It is an absolute uri, use standard urlparse
(self.scheme, self.host, self.path,
self.params, self.querystring, fragment) = urlparse.urlparse(self.uri)
if self.querystring:
self.args = cgi.parse_qs(self.querystring, True)
else:
self.args = {}
path = map(unquote, self.path[1:].split('/'))
if self._initialprepath:
# We were given an initial prepath -- this is for supporting
# CGI-ish applications where part of the path has already
# been processed
prepath = map(unquote, self._initialprepath[1:].split('/'))
if path[:len(prepath)] == prepath:
self.prepath = prepath
self.postpath = path[len(prepath):]
else:
self.prepath = []
self.postpath = path
else:
self.prepath = []
self.postpath = path
#print "_parseURL", self.uri, (self.uri, self.scheme, self.host, self.path, self.params, self.querystring)
def _fixupURLParts(self):
hostaddr, secure = self.chanRequest.getHostInfo()
if not self.scheme:
self.scheme = ('http', 'https')[secure]
if self.host:
self.host, self.port = http.splitHostPort(self.scheme, self.host)
else:
# If GET line wasn't an absolute URL
host = self.headers.getHeader('host')
if host:
self.host, self.port = http.splitHostPort(self.scheme, host)
else:
# When no hostname specified anywhere, either raise an
# error, or use the interface hostname, depending on
# protocol version
if self.clientproto >= (1,1):
raise http.HTTPError(responsecode.BAD_REQUEST)
self.host = hostaddr.host
self.port = hostaddr.port
def process(self):
"Process a request."
try:
self.checkExpect()
resp = self.preprocessRequest()
if resp is not None:
self._cbFinishRender(resp).addErrback(self._processingFailed)
return
self._parseURL()
self._fixupURLParts()
self.remoteAddr = self.chanRequest.getRemoteHost()
except:
failedDeferred = self._processingFailed(failure.Failure())
return
d = defer.Deferred()
d.addCallback(self._getChild, self.site.resource, self.postpath)
d.addCallback(lambda res, req: res.renderHTTP(req), self)
d.addCallback(self._cbFinishRender)
d.addErrback(self._processingFailed)
d.callback(None)
def preprocessRequest(self):
"""Do any request processing that doesn't follow the normal
resource lookup procedure. "OPTIONS *" is handled here, for
example. This would also be the place to do any CONNECT
processing."""
if self.method == "OPTIONS" and self.uri == "*":
response = http.Response(responsecode.OK)
response.headers.setHeader('allow', ('GET', 'HEAD', 'OPTIONS', 'TRACE'))
return response
# This is where CONNECT would go if we wanted it
return None
def _getChild(self, _, res, path, updatepaths=True):
"""Call res.locateChild, and pass the result on to _handleSegment."""
self.resources.append(res)
if not path:
return res
result = res.locateChild(self, path)
if isinstance(result, defer.Deferred):
return result.addCallback(self._handleSegment, res, path, updatepaths)
else:
return self._handleSegment(result, res, path, updatepaths)
def _handleSegment(self, result, res, path, updatepaths):
"""Handle the result of a locateChild call done in _getChild."""
newres, newpath = result
# If the child resource is None then display a error page
if newres is None:
raise http.HTTPError(responsecode.NOT_FOUND)
# If we got a deferred then we need to call back later, once the
# child is actually available.
if isinstance(newres, defer.Deferred):
return newres.addCallback(
lambda actualRes: self._handleSegment(
(actualRes, newpath), res, path, updatepaths)
)
if path:
url = quote("/" + "/".join(path))
else:
url = "/"
if newpath is StopTraversal:
# We need to rethink how to do this.
#if newres is res:
self._rememberResource(res, url)
return res
#else:
# raise ValueError("locateChild must not return StopTraversal with a resource other than self.")
newres = iweb.IResource(newres)
if newres is res:
assert not newpath is path, "URL traversal cycle detected when attempting to locateChild %r from resource %r." % (path, res)
assert len(newpath) < len(path), "Infinite loop impending..."
if updatepaths:
# We found a Resource... update the request.prepath and postpath
for x in xrange(len(path) - len(newpath)):
self.prepath.append(self.postpath.pop(0))
child = self._getChild(None, newres, newpath, updatepaths=updatepaths)
self._rememberResource(child, url)
return child
_urlsByResource = weakref.WeakKeyDictionary()
def _rememberResource(self, resource, url):
"""
Remember the URL of a visited resource.
"""
self._urlsByResource[resource] = url
return resource
def urlForResource(self, resource):
"""
Looks up the URL of the given resource if this resource was found while
processing this request. Specifically, this includes the requested
resource, and resources looked up via L{locateResource}.
Note that a resource may be found at multiple URIs; if the same resource
is visited at more than one location while processing this request,
this method will return one of those URLs, but which one is not defined,
nor whether the same URL is returned in subsequent calls.
@param resource: the resource to find a URI for. This resource must
have been obtained from the request (ie. via its C{uri} attribute, or
through its C{locateResource} or C{locateChildResource} methods).
@return: a valid URL for C{resource} in this request.
@raise NoURLForResourceError: if C{resource} has no URL in this request
(because it was not obtained from the request).
"""
resource = self._urlsByResource.get(resource, None)
if resource is None:
raise NoURLForResourceError(resource)
return resource
def locateResource(self, url):
"""
Looks up the resource with the given URL.
@param uri: The URL of the desired resource.
@return: a L{Deferred} resulting in the L{IResource} at the
given URL or C{None} if no such resource can be located.
@raise HTTPError: If C{url} is not a URL on the site that this
request is being applied to. The contained response will
have a status code of L{responsecode.BAD_GATEWAY}.
@raise HTTPError: If C{url} contains a query or fragment.
The contained response will have a status code of
L{responsecode.BAD_REQUEST}.
"""
if url is None: return None
#
# Parse the URL
#
(scheme, host, path, query, fragment) = urlsplit(url)
if query or fragment:
raise http.HTTPError(http.StatusResponse(
responsecode.BAD_REQUEST,
"URL may not contain a query or fragment: %s" % (url,)
))
# The caller shouldn't be asking a request on one server to lookup a
# resource on some other server.
if (scheme and scheme != self.scheme) or (host and host != self.headers.getHeader("host")):
raise http.HTTPError(http.StatusResponse(
responsecode.BAD_GATEWAY,
"URL is not on this site (%s://%s/): %s" % (scheme, self.headers.getHeader("host"), url)
))
segments = path.split("/")
assert segments[0] == "", "URL path didn't begin with '/': %s" % (path,)
segments = map(unquote, segments[1:])
def notFound(f):
f.trap(http.HTTPError)
if f.value.response.code != responsecode.NOT_FOUND:
return f
return None
d = defer.maybeDeferred(self._getChild, None, self.site.resource, segments, updatepaths=False)
d.addCallback(self._rememberResource, path)
d.addErrback(notFound)
return d
def locateChildResource(self, parent, childName):
"""
Looks up the child resource with the given name given the parent
resource. This is similar to locateResource(), but doesn't have to
start the lookup from the root resource, so it is potentially faster.
@param parent: the parent of the resource being looked up. This resource
must have been obtained from the request (ie. via its C{uri} attribute,
or through its C{locateResource} or C{locateChildResource} methods).
@param childName: the name of the child of C{parent} to looked up.
to C{parent}.
@return: a L{Deferred} resulting in the L{IResource} at the
given URL or C{None} if no such resource can be located.
@raise NoURLForResourceError: if C{resource} was not obtained from the
request.
"""
if parent is None or childName is None:
return None
assert "/" not in childName, "Child name may not contain '/': %s" % (childName,)
parentURL = self.urlForResource(parent)
if not parentURL.endswith("/"):
parentURL += "/"
url = parentURL + quote(childName)
segment = childName
def notFound(f):
f.trap(http.HTTPError)
if f.value.response.code != responsecode.NOT_FOUND:
return f
return None
d = defer.maybeDeferred(self._getChild, None, parent, [segment], updatepaths=False)
d.addCallback(self._rememberResource, url)
d.addErrback(notFound)
return d
def _processingFailed(self, reason):
if reason.check(http.HTTPError) is not None:
# If the exception was an HTTPError, leave it alone
d = defer.succeed(reason.value.response)
else:
# Otherwise, it was a random exception, so give a
# ICanHandleException implementer a chance to render the page.
def _processingFailed_inner(reason):
handler = iweb.ICanHandleException(self, self)
return handler.renderHTTP_exception(self, reason)
d = defer.maybeDeferred(_processingFailed_inner, reason)
d.addCallback(self._cbFinishRender)
d.addErrback(self._processingReallyFailed, reason)
return d
def _processingReallyFailed(self, reason, origReason):
log.msg("Exception rendering error page:", isErr=1)
log.err(reason)
log.msg("Original exception:", isErr=1)
log.err(origReason)
body = ("Internal Server Error"
"Internal Server Error
An error occurred rendering the requested page. Additionally, an error occured rendering the error page.")
response = http.Response(
responsecode.INTERNAL_SERVER_ERROR,
{'content-type': http_headers.MimeType('text','html')},
body)
self.writeResponse(response)
def _cbFinishRender(self, result):
def filterit(response, f):
if (hasattr(f, 'handleErrors') or
(response.code >= 200 and response.code < 300 and response.code != 204)):
return f(self, response)
else:
return response
response = iweb.IResponse(result, None)
if response:
d = defer.Deferred()
for f in self.responseFilters:
d.addCallback(filterit, f)
d.addCallback(self.writeResponse)
d.callback(response)
return d
resource = iweb.IResource(result, None)
if resource:
self.resources.append(resource)
d = defer.maybeDeferred(resource.renderHTTP, self)
d.addCallback(self._cbFinishRender)
return d
raise TypeError("html is not a resource or a response")
def renderHTTP_exception(self, req, reason):
log.msg("Exception rendering:", isErr=1)
log.err(reason)
body = ("Internal Server Error"
"Internal Server Error
An error occurred rendering the requested page. More information is available in the server log.")
return http.Response(
responsecode.INTERNAL_SERVER_ERROR,
{'content-type': http_headers.MimeType('text','html')},
body)
class Site(object):
def __init__(self, resource):
"""Initialize.
"""
self.resource = iweb.IResource(resource)
def __call__(self, *args, **kwargs):
return Request(site=self, *args, **kwargs)
class NoURLForResourceError(RuntimeError):
def __init__(self, resource):
RuntimeError.__init__(self, "Resource %r has no URL in this request." % (resource,))
self.resource = resource
__all__ = ['Request', 'Site', 'StopTraversal', 'VERSION', 'defaultHeadersFilter', 'doTrace', 'parsePOSTData', 'preconditionfilter', 'NoURLForResourceError']