1/* 2 * OpenVPN -- An application to securely tunnel IP networks 3 * over a single UDP port, with support for SSL/TLS-based 4 * session authentication and key exchange, 5 * packet encryption, packet authentication, and 6 * packet compression. 7 * 8 * Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 12 * as published by the Free Software Foundation. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program (see the file COPYING included with this 21 * distribution); if not, write to the Free Software Foundation, Inc., 22 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 23 */ 24 25#ifndef SHAPER_H 26#define SHAPER_H 27 28/*#define SHAPER_DEBUG*/ 29 30#ifdef ENABLE_FEATURE_SHAPER 31 32#include "basic.h" 33#include "integer.h" 34#include "misc.h" 35#include "error.h" 36#include "interval.h" 37 38/* 39 * A simple traffic shaper for 40 * the output direction. 41 */ 42 43#define SHAPER_MIN 100 /* bytes per second */ 44#define SHAPER_MAX 100000000 45 46#define SHAPER_MAX_TIMEOUT 10 /* seconds */ 47 48#define SHAPER_USE_FP 49 50struct shaper 51{ 52 int bytes_per_second; 53 struct timeval wakeup; 54 55#ifdef SHAPER_USE_FP 56 double factor; 57#else 58 int factor; 59#endif 60}; 61 62void shaper_msg (struct shaper *s); 63void shaper_reset_wakeup (struct shaper *s); 64 65/* 66 * We want to wake up in delay microseconds. If timeval is larger 67 * than delay, set timeval to delay. 68 */ 69bool shaper_soonest_event (struct timeval *tv, int delay); 70 71/* 72 * inline functions 73 */ 74 75static inline void 76shaper_reset (struct shaper *s, int bytes_per_second) 77{ 78 s->bytes_per_second = bytes_per_second ? constrain_int (bytes_per_second, SHAPER_MIN, SHAPER_MAX) : 0; 79 80#ifdef SHAPER_USE_FP 81 s->factor = 1000000.0 / (double)s->bytes_per_second; 82#else 83 s->factor = 1000000 / s->bytes_per_second; 84#endif 85} 86 87static inline void 88shaper_init (struct shaper *s, int bytes_per_second) 89{ 90 shaper_reset (s, bytes_per_second); 91 shaper_reset_wakeup (s); 92} 93 94static inline int 95shaper_current_bandwidth (struct shaper *s) 96{ 97 return s->bytes_per_second; 98} 99 100/* 101 * Returns traffic shaping delay in microseconds relative to current 102 * time, or 0 if no delay. 103 */ 104static inline int 105shaper_delay (struct shaper* s) 106{ 107 struct timeval tv; 108 int delay = 0; 109 110 if (tv_defined (&s->wakeup)) 111 { 112 ASSERT (!openvpn_gettimeofday (&tv, NULL)); 113 delay = tv_subtract (&s->wakeup, &tv, SHAPER_MAX_TIMEOUT); 114#ifdef SHAPER_DEBUG 115 dmsg (D_SHAPER_DEBUG, "SHAPER shaper_delay delay=%d", delay); 116#endif 117 } 118 119 return delay > 0 ? delay : 0; 120} 121 122 123/* 124 * We are about to send a datagram of nbytes bytes. 125 * 126 * Compute when we can send another datagram, 127 * based on target throughput (s->bytes_per_second). 128 */ 129static inline void 130shaper_wrote_bytes (struct shaper* s, int nbytes) 131{ 132 struct timeval tv; 133 134 /* compute delay in microseconds */ 135 tv.tv_sec = 0; 136#ifdef SHAPER_USE_FP 137 tv.tv_usec = min_int ((int)((double)max_int (nbytes, 100) * s->factor), (SHAPER_MAX_TIMEOUT*1000000)); 138#else 139 tv.tv_usec = s->bytes_per_second 140 ? min_int (max_int (nbytes, 100) * s->factor, (SHAPER_MAX_TIMEOUT*1000000)) 141 : 0; 142#endif 143 144 if (tv.tv_usec) 145 { 146 ASSERT (!openvpn_gettimeofday (&s->wakeup, NULL)); 147 tv_add (&s->wakeup, &tv); 148 149#ifdef SHAPER_DEBUG 150 dmsg (D_SHAPER_DEBUG, "SHAPER shaper_wrote_bytes bytes=%d delay=%d sec=%d usec=%d", 151 nbytes, 152 (int)tv.tv_usec, 153 (int)s->wakeup.tv_sec, 154 (int)s->wakeup.tv_usec); 155#endif 156 } 157} 158 159#if 0 160/* 161 * Increase/Decrease bandwidth by a percentage. 162 * 163 * Return true if bandwidth changed. 164 */ 165static inline bool 166shaper_change_pct (struct shaper *s, int pct) 167{ 168 const int orig_bandwidth = s->bytes_per_second; 169 const int new_bandwidth = orig_bandwidth + (orig_bandwidth * pct / 100); 170 ASSERT (s->bytes_per_second); 171 shaper_reset (s, new_bandwidth); 172 return s->bytes_per_second != orig_bandwidth; 173} 174#endif 175 176#endif /* ENABLE_FEATURE_SHAPER */ 177 178#endif 179