/* * PIE - Proportional Integral controller Enhanced AQM algorithm. * * $FreeBSD$ * * Copyright (C) 2016 Centre for Advanced Internet Architectures, * Swinburne University of Technology, Melbourne, Australia. * Portions of this code were made possible in part by a gift from * The Comcast Innovation Fund. * Implemented by Rasool Al-Saadi <ralsaadi@swin.edu.au> * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef _IP_DN_AQM_PIE_H #define _IP_DN_AQM_PIE_H #define DN_AQM_PIE 2 #define PIE_DQ_THRESHOLD_BITS 14 /* 2^14 =16KB */ #define PIE_DQ_THRESHOLD (1UL << PIE_DQ_THRESHOLD_BITS) #define MEAN_PKTSIZE 800 /* 31-bits because random() generates range from 0->(2**31)-1 */ #define PIE_PROB_BITS 31 #define PIE_MAX_PROB ((1ULL<<PIE_PROB_BITS) -1) /* for 16-bits, we have 3-bits for integer part and 13-bits for fraction */ #define PIE_FIX_POINT_BITS 13 #define PIE_SCALE (1UL<<PIE_FIX_POINT_BITS) /* PIE options */ enum { PIE_ECN_ENABLED =1, PIE_CAPDROP_ENABLED = 2, PIE_ON_OFF_MODE_ENABLED = 4, PIE_DEPRATEEST_ENABLED = 8, PIE_DERAND_ENABLED = 16 }; /* PIE parameters */ struct dn_aqm_pie_parms { aqm_time_t qdelay_ref; /* AQM Latency Target (default: 15ms) */ aqm_time_t tupdate; /* a period to calculate drop probability (default:15ms) */ aqm_time_t max_burst; /* AQM Max Burst Allowance (default: 150ms) */ uint16_t max_ecnth; /*AQM Max ECN Marking Threshold (default: 10%) */ uint16_t alpha; /* (default: 1/8) */ uint16_t beta; /* (default: 1+1/4) */ uint32_t flags; /* PIE options */ }; /* PIE status variables */ struct pie_status{ struct callout aqm_pie_callout; aqm_time_t burst_allowance; uint32_t drop_prob; aqm_time_t current_qdelay; aqm_time_t qdelay_old; uint64_t accu_prob; aqm_time_t measurement_start; aqm_time_t avg_dq_time; uint32_t dq_count; uint32_t sflags; struct dn_aqm_pie_parms *parms; /* pointer to PIE configurations */ /* pointer to parent queue of FQ-PIE sub-queues, or queue of owner fs. */ struct dn_queue *pq; struct mtx lock_mtx; uint32_t one_third_q_size; /* 1/3 of queue size, for speed optization */ }; enum { ENQUE = 1, DROP, MARKECN }; /* PIE current state */ enum { PIE_ACTIVE = 1, PIE_INMEASUREMENT = 2 }; /* * Check if eneque should drop packet to control delay or not based on * PIe algorithm. * return DROP if it is time to drop or ENQUE otherwise. * This function is used by PIE and FQ-PIE. */ __inline static int drop_early(struct pie_status *pst, uint32_t qlen) { struct dn_aqm_pie_parms *pprms; pprms = pst->parms; /* queue is not congested */ if ((pst->qdelay_old < (pprms->qdelay_ref >> 1) && pst->drop_prob < PIE_MAX_PROB / 5 ) || qlen <= 2 * MEAN_PKTSIZE) return ENQUE; if (pst->drop_prob == 0) pst->accu_prob = 0; /* increment accu_prob */ if (pprms->flags & PIE_DERAND_ENABLED) pst->accu_prob += pst->drop_prob; /* De-randomize option * if accu_prob < 0.85 -> enqueue * if accu_prob>8.5 ->drop * between 0.85 and 8.5 || !De-randomize --> drop on prob * * (0.85 = 17/20 ,8.5 = 17/2) */ if (pprms->flags & PIE_DERAND_ENABLED) { if(pst->accu_prob < (uint64_t) (PIE_MAX_PROB * 17 / 20)) return ENQUE; if( pst->accu_prob >= (uint64_t) (PIE_MAX_PROB * 17 / 2)) return DROP; } if (random() < pst->drop_prob) { pst->accu_prob = 0; return DROP; } return ENQUE; } #endif