bird/lib/tbf.c

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/*
* BIRD Library -- Token Bucket Filter
*
* (c) 2014 Ondrej Zajicek <santiago@crfreenet.org>
* (c) 2014 CZ.NIC z.s.p.o.
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include "nest/bird.h"
#include "lib/timer.h"
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int
tbf_limit(struct tbf *f)
{
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btime delta = current_time() - f->timestamp;
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if (delta > 0)
{
u64 next = f->count + delta * f->rate;
u64 burst = (u64) f->burst << 20;
f->count = MIN(next, burst);
f->timestamp += delta;
}
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if (f->count < 1000000)
{
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f->drop++;
return 1;
}
else
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{
f->count -= 1000000;
f->drop = 0;
return 0;
}
}