Add a session callback pointer to struct sess.

git-svn-id: http://www.varnish-cache.org/svn/trunk@107 d4fa192b-c00b-0410-8231-f00ffab90ce4

include/vcl_lang.h

@@ -8,6 +8,9 @@
 /* XXX: This include is bad.  The VCL compiler shouldn't know about it. */
 #include <sys/queue.h>
 
+struct sess;
+typedef void sesscb_f(struct sess *sp);
+
 struct vcl_ref {
 	unsigned	line;
 	unsigned	pos;
@@ -59,6 +62,8 @@ struct sess {
 
 	TAILQ_ENTRY(sess)	list;
 
+	sesscb_f		*sesscb;
+
 	struct backend		*backend;
 	struct VCL_conf		*vcl;