1 files changed, 33 insertions, 1 deletions
diff --git a/fw/src/rules.h b/fw/src/rules.h
index 6aad0ae..f2c38d4 100644
--- a/fw/src/rules.h
+++ b/fw/src/rules.h
@@ -49,7 +49,39 @@ long	fmtrules(char*, long);		/* current set, back in ndb form */
 long	fmthits(char*, long);		/* the same, with hit counts */
 void	dumprules(void);
 void	checklogging(void);
-char*	matchrule(int verb, char *proto, uchar *ip, int anyip, int port, int lport, Rule**);
+/*
+ * One question for the rule list, and its answer, in the caller's
+ * frame.
+ *
+ * matchrule used to hand back a Rule* and a pointer into a static
+ * buffer, and callers read both after it had let go of the lock.  A
+ * rule set installed in between freed the Rule under them, and two
+ * procs deciding at once overwrote each other's reason - in a program
+ * whose entire output is the reason.  Nothing here outlives the Match,
+ * and the Match belongs to whoever asked.
+ *
+ * count says to charge the decision to the rule's tally.  Re-checking
+ * live flows after a rule change is not traffic and must not be
+ * counted, or "how often has this rule decided something" answers a
+ * different question every time the rules are edited.
+ */
+typedef struct Match Match;
+struct Match
+{
+	int	verb;			/* in */
+	char	*proto;			/* nil: any */
+	uchar	*ip;			/* the peer; unread if anyip */
+	int	anyip;
+	int	port;			/* peer port, -1: any */
+	int	lport;			/* local port, -1: any */
+	int	count;			/* charge this to the rule */
+
+	int	nr;			/* out: the rule that decided, 0 if none */
+	int	log;			/* it asked to be logged */
+	char	err[128];		/* why not, if it said no */
+};
+
+int	matchrule(Match*);		/* 1 to permit, 0 to refuse */
 int	protoname2num(char*);
 char*	protonum2name(int);