# This is a sample ISAPI extension written in Python.
#
# Please see README.txt in this directory, and specifically the
# information about the "loader" DLL - installing this sample will create
# "_redirector.dll" in the current directory. The readme explains this.
# Executing this script (or any server config script) will install the extension
# into your web server. As the server executes, the PyISAPI framework will load
# this module and create your Extension and Filter objects.
# This is the simplest possible redirector (or proxy) we can write. The
# extension installs with a mask of '*' in the root of the site.
# As an added bonus though, we optionally show how, on IIS6 and later, we
# can use HSE_ERQ_EXEC_URL to ignore certain requests - in IIS5 and earlier
# we can only do this with an ISAPI filter - see redirector_with_filter for
# an example. If this sample is run on IIS5 or earlier it simply ignores
# any excludes.
from isapi import isapicon,threaded_extension
import sys
import traceback
try:
from urllib import urlopen
except ImportError:
# py3k spelling...
from urllib.request import urlopen
import win32api
# sys.isapidllhandle will exist when we are loaded by the IIS framework.
# In this case we redirect our output to the win32traceutil collector.
if hasattr(sys, "isapidllhandle"):
import win32traceutil
# The site we are proxying.
proxy = "http://www.python.org"
# Urls we exclude (ie, allow IIS to handle itself) - all are lowered,
# and these entries exist by default on Vista...
excludes = ["/iisstart.htm", "/welcome.png"]
# An "io completion" function, called when ecb.ExecURL completes...
def io_callback(ecb, url, cbIO, errcode):
# Get the status of our ExecURL
httpstatus, substatus, win32 = ecb.GetExecURLStatus()
print "ExecURL of %r finished with http status %d.%d, win32 status %d (%s)" % (
url, httpstatus, substatus, win32, win32api.FormatMessage(win32).strip())
# nothing more to do!
ecb.DoneWithSession()
# The ISAPI extension - handles all requests in the site.
class Extension(threaded_extension.ThreadPoolExtension):
"Python sample Extension"
def Dispatch(self, ecb):
# Note that our ThreadPoolExtension base class will catch exceptions
# in our Dispatch method, and write the traceback to the client.
# That is perfect for this sample, so we don't catch our own.
#print 'IIS dispatching "%s"' % (ecb.GetServerVariable("URL"),)
url = ecb.GetServerVariable("URL").decode("ascii")
for exclude in excludes:
if url.lower().startswith(exclude):
print "excluding %s" % url
if ecb.Version < 0x60000:
print "(but this is IIS5 or earlier - can't do 'excludes')"
else:
ecb.IOCompletion(io_callback, url)
ecb.ExecURL(None, None, None, None, None, isapicon.HSE_EXEC_URL_IGNORE_CURRENT_INTERCEPTOR)
return isapicon.HSE_STATUS_PENDING
new_url = proxy + url
print "Opening %s" % new_url
fp = urlopen(new_url)
headers = fp.info()
# subtle py3k breakage: in py3k, str(headers) has normalized \r\n
# back to \n and also stuck an extra \n term. py2k leaves the
# \r\n from the server in tact and finishes with a single term.
if sys.version_info < (3,0):
header_text = str(headers) + "\r\n"
else:
# take *all* trailing \n off, replace remaining with
# \r\n, then add the 2 trailing \r\n.
header_text = str(headers).rstrip('\n').replace('\n', '\r\n') + '\r\n\r\n'
ecb.SendResponseHeaders("200 OK", header_text, False)
ecb.WriteClient(fp.read())
ecb.DoneWithSession()
print "Returned data from '%s'" % (new_url,)
return isapicon.HSE_STATUS_SUCCESS
# The entry points for the ISAPI extension.
def __ExtensionFactory__():
return Extension()
if __name__=='__main__':
# If run from the command-line, install ourselves.
from isapi.install import *
params = ISAPIParameters()
# Setup the virtual directories - this is a list of directories our
# extension uses - in this case only 1.
# Each extension has a "script map" - this is the mapping of ISAPI
# extensions.
sm = [
ScriptMapParams(Extension="*", Flags=0)
]
vd = VirtualDirParameters(Name="/",
Description = Extension.__doc__,
ScriptMaps = sm,
ScriptMapUpdate = "replace"
)
params.VirtualDirs = [vd]
HandleCommandLine(params)
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