diff -r 6f9166cf333a -r b3a835aa617c tun/tun.patch
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tun/tun.patch	Mon Jan 12 19:09:19 2009 +0100
@@ -0,0 +1,53 @@
+Index: linux/2.2/tun.c
+--- linux/2.2/tun.c.orig	2006-10-10 14:45:00.338589000 +0200
++++ linux/2.2/tun.c	2006-10-10 14:44:05.695404000 +0200
+@@ -178,10 +178,22 @@
+ 
+    DBG( KERN_INFO "%s: tun_chr_poll\n", tun->name);
+ 
++   /* Data written to the /dev/tunX device is immediately placed into a socket buffer, making it
++    * available to networking code at the tunX interface.  Writes never block.
++    * Likewise, data flows from the network stack, through the tunX interface and into the /dev/tun* device,
++    * where it is queued, making it available for read().
++    * Thus the character device /dev/tunX is:
++    *   - readable if data was "transmitted" to the tunX interface and is now queued at the /dev/tunX device.
++    *   - always writable.
++    * Everything written here is equally true of taps.
++    * The author made a mistake when implementing this routine; he forgot that the device is always writable.
++    * -jeff stearns 22-Dec-2005
++    */
++
+    poll_wait(file, &tun->read_wait, wait);
+  
+    if( skb_queue_len(&tun->txq) )
+-      return POLLIN | POLLRDNORM;
++      return POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM;
+ 
+    return POLLOUT | POLLWRNORM;
+ }
+Index: linux/2.4/tun.c
+--- linux/2.4/tun.c.orig	2006-10-10 14:41:57.910408000 +0200
++++ linux/2.4/tun.c	2006-10-10 14:43:40.067700000 +0200
+@@ -176,9 +176,21 @@
+ 	DBG(KERN_INFO "%s: tun_chr_poll\n", tun->name);
+ 
+ 	poll_wait(file, &tun->read_wait, wait);
++
++	/* Data written to the /dev/tunX device is immediately placed into a socket buffer, making it
++	 * available to networking code at the tunX interface.  Writes never block.
++	 * Likewise, data flows from the network stack, through the tunX interface and into the /dev/tun* device,
++	 * where it is queued, making it available for read().
++	 * Thus the character device /dev/tunX is:
++	 *   - readable if data was "transmitted" to the tunX interface and is now queued at the /dev/tunX device.
++	 *   - always writable.
++	 * Everything written here is equally true of taps.
++	 * The author made a mistake when implementing this routine; he forgot that the device is always writable.
++	 * -jeff stearns 22-Dec-2005
++	 */
+  
+ 	if (skb_queue_len(&tun->txq))
+-		return POLLIN | POLLRDNORM;
++		return POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM;
+ 
+ 	return POLLOUT | POLLWRNORM;
+ }