[CalendarServer-changes] [8983] CalendarServer/trunk/calendarserver/tap/caldav.py

[source_changes at macosforge.org]

Revision: 8983
          http://trac.macosforge.org/projects/calendarserver/changeset/8983
Author:   glyph at apple.com
Date:     2012-04-04 15:57:26 -0700 (Wed, 04 Apr 2012)
Log Message:
-----------
Account for the possbility of platform shenanigans when binding IPv6 addresses.

Modified Paths:
--------------
    CalendarServer/trunk/calendarserver/tap/caldav.py

Modified: CalendarServer/trunk/calendarserver/tap/caldav.py
===================================================================
--- CalendarServer/trunk/calendarserver/tap/caldav.py	2012-04-04 22:37:43 UTC (rev 8982)
+++ CalendarServer/trunk/calendarserver/tap/caldav.py	2012-04-04 22:57:26 UTC (rev 8983)
@@ -124,6 +124,36 @@
 
 
 
+def conflictBetweenIPv4AndIPv6():
+    """
+    Is there a conflict between binding an IPv6 and an IPv4 port?  Return True
+    if there is, False if there isn't.
+
+    This is a temporary workaround until maybe Twisted starts setting
+    C{IPPROTO_IPV6 / IPV6_V6ONLY} on IPv6 sockets.
+
+    @return: C{True} if listening on IPv4 conflicts with listening on IPv6.
+    """
+    s4 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    s6 = socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
+    try:
+        s4.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        s6.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        s4.bind(("", 0))
+        s4.listen(1)
+        usedport = s4.getsockname()[1]
+        try:
+            s6.bind(("::", usedport))
+        except socket.error:
+            return True
+        else:
+            return False
+    finally:
+        s4.close()
+        s6.close()
+
+
+
 def _computeEnvVars(parent):
     """
     Compute environment variables to be propagated to child processes.
@@ -867,7 +897,16 @@
         and IPv6".
         """
         if not config.BindAddresses:
-            config.BindAddresses = ["", "::"]
+            if getattr(socket, "has_ipv6", False):
+                if conflictBetweenIPv4AndIPv6():
+                    # If there's a conflict between v4 and v6, then almost by
+                    # definition, v4 is mapped into the v6 space, so we will
+                    # listen "only" on v6.
+                    config.BindAddresses = ["::"]
+                else:
+                    config.BindAddresses = ["", "::"]
+            else:
+                config.BindAddresses = [""]
         return config.BindAddresses
 
 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.macosforge.org/pipermail/calendarserver-changes/attachments/20120404/d3367e0e/attachment.html>