diff options
| -rw-r--r-- | sys/kern/kern_time.c | 79 |
1 files changed, 24 insertions, 55 deletions
diff --git a/sys/kern/kern_time.c b/sys/kern/kern_time.c index 169d5e0..2d53d3f 100644 --- a/sys/kern/kern_time.c +++ b/sys/kern/kern_time.c @@ -664,21 +664,8 @@ timevalfix(struct timeval *t1) } } -#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 - /* - * ratecheck(): simple time-based rate-limit checking. see ratecheck(9) - * for usage and rationale. + * ratecheck(): simple time-based rate-limit checking. */ int ratecheck(struct timeval *lasttime, const struct timeval *mininterval) @@ -686,8 +673,9 @@ ratecheck(struct timeval *lasttime, const struct timeval *mininterval) struct timeval tv, delta; int rv = 0; - getmicrouptime(&tv); - timersub(&tv, lasttime, &delta); + getmicrouptime(&tv); /* NB: 10ms precision */ + delta = tv; + timevalsub(&delta, lasttime); /* * check for 0,0 is so that the message will be seen at least once, @@ -704,50 +692,31 @@ ratecheck(struct timeval *lasttime, const struct timeval *mininterval) /* * ppsratecheck(): packets (or events) per second limitation. + * + * Return 0 if the limit is to be enforced (e.g. the caller + * should drop a packet because of the rate limitation). + * + * Note that we maintain the struct timeval for compatibility + * with other bsd systems. We reuse the storage and just monitor + * clock ticks for minimal overhead. */ int ppsratecheck(struct timeval *lasttime, int *curpps, int maxpps) { - struct timeval tv, delta; - int rv; - - getmicrouptime(&tv); - timersub(&tv, lasttime, &delta); + int now; /* - * check for 0,0 is so that the message will be seen at least once. - * if more than one second have 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. + * Reset the last time and counter if this is the first call + * or more than a second has passed since the last update of + * lasttime. */ - 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); + now = ticks; + if (lasttime->tv_sec == 0 || (u_int)(now - lasttime->tv_sec) >= hz) { + lasttime->tv_sec = now; + *curpps = 1; + return (1); + } else { + (*curpps)++; /* NB: ignore potential overflow */ + return (maxpps < 0 || *curpps < maxpps); + } } |
