we have ppsratecheck().

sys/net/net_osdep.h

@@ -304,6 +304,7 @@ extern const char *if_name(struct ifnet *);
 #define if_addrlist	if_addrhead
 #define if_list		if_link
 
+#define HAVE_PPSRATECHECK
 #define WITH_CONVERT_AND_STRIP_IP_LEN
 
 #if 1				/* at this moment, all OSes do this */

sys/netinet6/icmp6.c

@@ -129,10 +129,6 @@ static int icmp6_rip6_input __P((struct mbuf **, int));
 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int));
 static const char *icmp6_redirect_diag __P((struct in6_addr *,
 	struct in6_addr *, struct in6_addr *));
-#define	HAVE_PPSRATECHECK
-#ifndef HAVE_PPSRATECHECK
-static int ppsratecheck __P((struct timeval *, int *, int));
-#endif
 static struct mbuf *ni6_input __P((struct mbuf *, int));
 static struct mbuf *ni6_nametodns __P((const char *, int, int));
 static int ni6_dnsmatch __P((const char *, int, const char *, int));
@@ -2738,76 +2734,6 @@ icmp6_ctloutput(so, sopt)
 	return (error);
 }
 
-#ifndef HAVE_PPSRATECHECK
-#ifndef timersub
-#define	timersub(tvp, uvp, vvp)						\
-	do {								\
-		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
-		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
-		if ((vvp)->tv_usec < 0) {				\
-			(vvp)->tv_sec--;				\
-			(vvp)->tv_usec += 1000000;			\
-		}							\
-	} while (0)
-#endif
-
-/*
- * ppsratecheck(): packets (or events) per second limitation.
- */
-static int
-ppsratecheck(lasttime, curpps, maxpps)
-	struct timeval *lasttime;
-	int *curpps;
-	int maxpps;	/* maximum pps allowed */
-{
-	struct timeval tv, delta;
-	int s, rv;
-
-	s = splclock(); 
-	microtime(&tv);
-	splx(s);
-
-	timersub(&tv, lasttime, &delta);
-
-	/*
-	 * Check for 0,0 so that the message will be seen at least once.
-	 * If more than one second has passed since the last update of
-	 * lasttime, reset the counter.
-	 *
-	 * We do increment *curpps even in *curpps < maxpps case, as some may
-	 * try to use *curpps for stat purposes as well.
-	 */
-	if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
-	    delta.tv_sec >= 1) {
-		*lasttime = tv;
-		*curpps = 0;
-		rv = 1;
-	} else if (maxpps < 0)
-		rv = 1;
-	else if (*curpps < maxpps)
-		rv = 1;
-	else
-		rv = 0;
-
-#if 1 /* DIAGNOSTIC? */
-	/* be careful about wrap-around */
-	if (*curpps + 1 > *curpps)
-		*curpps = *curpps + 1;
-#else
-	/*
-	 * assume that there's not too many calls to this function.
-	 * not sure if the assumption holds, as it depends on *caller's*
-	 * behavior, not the behavior of this function.
-	 * IMHO it is wrong to make assumption on the caller's behavior,
-	 * so the above #if is #if 1, not #ifdef DIAGNOSTIC.
-	 */
-	*curpps = *curpps + 1;
-#endif
-
-	return (rv);
-}
-#endif
-
 /*
  * Perform rate limit check.
  * Returns 0 if it is okay to send the icmp6 packet.