Implemented smarter-than-REMOTE_ADDR proposal. IP-based access controls now work through a proxy.

doc/CHANGES.txt

@@ -12,6 +12,13 @@ Zope Changes
        objects to allow gathering of permission names for products like
        DocFinder and VerboseSecurity.
 
+     - Added a new REQUEST method, getClientAddr(), to determine a clients
+       IP address. Address restrictions in the user folder have been changed
+       to use this method. By default the value returned by this method is the
+       same as the initial value of REQUEST['REMOTE_ADDR']. Zope also has
+       support for obtaining a more useful value from other headers if a
+       front-end proxy is in use. See doc/ENVIRONMENT.txt for details.
+
     Bugs Fixed
 
      - The ZEO unit tests and wo_pcgi.py didn't run on Windows if the path 

doc/ENVIRONMENT.txt

@@ -78,6 +78,15 @@ SiteAccess
         If set, all site access rules are suppressed (used by SiteAccess
         products).
 
+ZPublisher
+
+    ZOPE_TRUSTED_PROXIES
+
+	A colon seperated list of IP addresses which run trusted
+        proxy servers. If a connection comes from an address listed
+        here, Zope will trust any X-Forwarded-For header to contain
+        the users real IP address for the purposes of address-based
+        authentication limits.
 
 ZEO
 

lib/python/AccessControl/User.py

@@ -12,7 +12,7 @@
 ##############################################################################
 """Access control package"""
 
-__version__='$Revision: 1.174 $'[11:-2]
+__version__='$Revision: 1.175 $'[11:-2]
 
 import Globals, socket, SpecialUsers,re
 import os
@@ -1113,8 +1113,7 @@ def domainSpecMatch(spec, request):
     if request.has_key('REMOTE_HOST'):
         host=request['REMOTE_HOST']
 
-    if request.has_key('REMOTE_ADDR'):
-        addr=request['REMOTE_ADDR']
+    addr=request.getClientAddr()
 
     if not host and not addr:
         return 0

lib/python/ZPublisher/HTTPRequest.py

@@ -11,7 +11,7 @@
 #
 ##############################################################################
 
-__version__='$Revision: 1.86 $'[11:-2]
+__version__='$Revision: 1.87 $'[11:-2]
 
 import re, sys, os,  urllib, time, random, cgi, codecs
 from types import StringType, UnicodeType
@@ -223,6 +223,11 @@ class HTTPRequest(BaseRequest):
             del self.other[x]
         self._urls = ()
 
+    def getClientAddr(self):
+        """ The IP address of the client.
+        """
+        return self._client_addr
+
     def __init__(self, stdin, environ, response, clean=0):
         self._orig_env=environ
         # Avoid the overhead of scrubbing the environment in the
@@ -248,6 +253,16 @@ class HTTPRequest(BaseRequest):
         self._steps=[]
         self._lazies={}
 
+
+        if environ.has_key('REMOTE_ADDR'):
+            self._client_addr = environ['REMOTE_ADDR']
+            if environ.has_key('HTTP_X_FORWARDED_FOR') and self._client_addr in trusted_proxies:
+                # REMOTE_ADDR is one of our trusted local proxies. Not really very remote at all.
+                # The proxy can tell us the IP of the real remote client in the forwarded-for header
+                self._client_addr = environ['HTTP_X_FORWARDED_FOR'].split(',')[-1].strip()
+        else:
+            self._client_addr = ''
+
         ################################################################
         # Get base info first. This isn't likely to cause
         # errors and might be useful to error handlers.
@@ -1489,3 +1504,20 @@ RECORDS=8
 REC=RECORD|RECORDS
 EMPTY=16
 CONVERTED=32
+
+
+# The ZOPE_TRUSTED_PROXIES environment variable contains a colon separated 
+# list of front-end proxies that are trusted to supply an accurate
+# X_FORWARDED_FOR header. If REMOTE_ADDR is one of the values in this list
+# and it has set an X_FORWARDED_FOR header, ZPublisher copies REMOTE_ADDR
+# into X_FORWARDED_BY, and the last element of the X_FORWARDED_FOR list
+# into REMOTE_ADDR. X_FORWARDED_FOR is left unchanged.
+# This function parses the environment variable into a module variable
+# 
+def trusted_proxies():
+    proxies = os.environ.get('ZOPE_TRUSTED_PROXIES','')
+    proxies = proxies.split(':')
+    proxies = [p.strip() for p in proxies]
+    return tuple(proxies)
+trusted_proxies = trusted_proxies()
+