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* OpenVPN -- An application to securely tunnel IP networks
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* over a single UDP port, with support for SSL/TLS-based
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* session authentication and key exchange,
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* packet encryption, packet authentication, and
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* Copyright (C) 2002-2004 James Yonan <jim@yonan.net>
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program (see the file COPYING included with this
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* distribution); if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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#define SHAPER_DEBUG 0
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#ifdef HAVE_GETTIMEOFDAY
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* A simple traffic shaper for
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* the output direction.
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#define SHAPER_MIN 100 /* bytes per second */
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#define SHAPER_MAX 100000000
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#define SHAPER_MAX_TIMEOUT 10 /* seconds */
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struct timeval wakeup;
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void shaper_msg (struct shaper *s);
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shaper_reset (struct shaper *s, int bytes_per_second)
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s->bytes_per_second = bytes_per_second ? constrain_int (bytes_per_second, SHAPER_MIN, SHAPER_MAX) : 0;
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shaper_reset_wakeup (struct shaper *s)
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shaper_init (struct shaper *s, int bytes_per_second)
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shaper_reset (s, bytes_per_second);
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shaper_reset_wakeup (s);
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shaper_current_bandwidth (struct shaper *s)
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return s->bytes_per_second;
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* Returns traffic shaping delay in microseconds relative to current
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* time, or 0 if no delay.
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shaper_delay (struct shaper* s)
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if (tv_defined (&s->wakeup))
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ASSERT (!gettimeofday (&tv, NULL));
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delay = tv_subtract (&s->wakeup, &tv, SHAPER_MAX_TIMEOUT);
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msg (D_SHAPER_DEBUG, "SHAPER shaper_delay delay=%d", delay);
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return delay > 0 ? delay : 0;
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* We want to wake up in delay microseconds. If timeval is 0 (undefined) or larger
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* than delay, set timeval to delay.
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shaper_soonest_event (struct timeval *tv, int delay)
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if (!tv->tv_usec && delay < 1000000)
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const int sec = delay / 1000000;
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const int usec = delay % 1000000;
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if ((!tv->tv_sec && !tv->tv_usec) || (sec < tv->tv_sec))
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else if (sec == tv->tv_sec)
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if (usec < tv->tv_usec)
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msg (D_SHAPER_DEBUG, "SHAPER shaper_soonest_event sec=%d usec=%d",
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(int)tv->tv_sec, (int)tv->tv_usec);
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* We are about to send a datagram of nbytes bytes.
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* Compute when we can send another datagram,
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* based on target throughput (s->bytes_per_second).
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shaper_wrote_bytes (struct shaper* s, int nbytes)
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/* delay in microseconds */
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const int delay = s->bytes_per_second
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? min_int (((1000000 / s->bytes_per_second) * max_int (nbytes, 200)), (SHAPER_MAX_TIMEOUT*1000000))
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ASSERT (!gettimeofday (&s->wakeup, NULL));
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s->wakeup.tv_usec += delay;
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while (s->wakeup.tv_usec >= 1000000)
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s->wakeup.tv_usec -= 1000000;
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msg (D_SHAPER_DEBUG, "SHAPER shaper_wrote_bytes bytes=%d delay=%d sec=%d usec=%d",
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nbytes, delay, (int)s->wakeup.tv_sec, (int)s->wakeup.tv_usec);
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* Increase/Decrease bandwidth by a percentage.
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* Return true if bandwidth changed.
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shaper_change_pct (struct shaper *s, int pct)
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const int orig_bandwidth = s->bytes_per_second;
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const int new_bandwidth = orig_bandwidth + (orig_bandwidth * pct / 100);
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ASSERT (s->bytes_per_second);
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shaper_reset (s, new_bandwidth);
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return s->bytes_per_second != orig_bandwidth;
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#endif /* HAVE_GETTIMEOFDAY */
added
removed
shaper.h
