/* * FQ_PIE - The FlowQueue-PIE scheduler/AQM * * 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 * * 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. */ /* Important note: * As there is no an office document for FQ-PIE specification, we used * FQ-CoDel algorithm with some modifications to implement FQ-PIE. * This FQ-PIE implementation is a beta version and have not been tested * extensively. Our FQ-PIE uses stand-alone PIE AQM per sub-queue. By * default, timestamp is used to calculate queue delay instead of departure * rate estimation method. Although departure rate estimation is available * as testing option, the results could be incorrect. Moreover, turning PIE on * and off option is available but it does not work properly in this version. */ #ifdef _KERNEL #include #include #include #include #include #include #include #include /* IFNAMSIZ */ #include #include /* ipfw_rule_ref */ #include /* flow_id */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #else #include #endif #define DN_SCHED_FQ_PIE 7 /* list of queues */ STAILQ_HEAD(fq_pie_list, fq_pie_flow); /* FQ_PIE parameters including PIE */ struct dn_sch_fq_pie_parms { struct dn_aqm_pie_parms pcfg; /* PIE configuration Parameters */ /* FQ_PIE Parameters */ uint32_t flows_cnt; /* number of flows */ uint32_t limit; /* hard limit of FQ_PIE queue size*/ uint32_t quantum; }; /* flow (sub-queue) stats */ struct flow_stats { uint64_t tot_pkts; /* statistics counters */ uint64_t tot_bytes; uint32_t length; /* Queue length, in packets */ uint32_t len_bytes; /* Queue length, in bytes */ uint32_t drops; }; /* A flow of packets (sub-queue)*/ struct fq_pie_flow { struct mq mq; /* list of packets */ struct flow_stats stats; /* statistics */ int deficit; int active; /* 1: flow is active (in a list) */ struct pie_status pst; /* pie status variables */ struct fq_pie_si_extra *psi_extra; STAILQ_ENTRY(fq_pie_flow) flowchain; }; /* extra fq_pie scheduler configurations */ struct fq_pie_schk { struct dn_sch_fq_pie_parms cfg; }; /* fq_pie scheduler instance extra state vars. * The purpose of separation this structure is to preserve number of active * sub-queues and the flows array pointer even after the scheduler instance * is destroyed. * Preserving these varaiables allows freeing the allocated memory by * fqpie_callout_cleanup() independently from fq_pie_free_sched(). */ struct fq_pie_si_extra { uint32_t nr_active_q; /* number of active queues */ struct fq_pie_flow *flows; /* array of flows (queues) */ }; /* fq_pie scheduler instance */ struct fq_pie_si { struct dn_sch_inst _si; /* standard scheduler instance. SHOULD BE FIRST */ struct dn_queue main_q; /* main queue is after si directly */ uint32_t perturbation; /* random value */ struct fq_pie_list newflows; /* list of new queues */ struct fq_pie_list oldflows; /* list of old queues */ struct fq_pie_si_extra *si_extra; /* extra state vars*/ }; static struct dn_alg fq_pie_desc; /* Default FQ-PIE parameters including PIE */ /* PIE defaults * target=15ms, max_burst=150ms, max_ecnth=0.1, * alpha=0.125, beta=1.25, tupdate=15ms * FQ- * flows=1024, limit=10240, quantum =1514 */ struct dn_sch_fq_pie_parms fq_pie_sysctl = {{15000 * AQM_TIME_1US, 15000 * AQM_TIME_1US, 150000 * AQM_TIME_1US, PIE_SCALE * 0.1, PIE_SCALE * 0.125, PIE_SCALE * 1.25, PIE_CAPDROP_ENABLED | PIE_DERAND_ENABLED}, 1024, 10240, 1514}; static int fqpie_sysctl_alpha_beta_handler(SYSCTL_HANDLER_ARGS) { int error; long value; if (!strcmp(oidp->oid_name,"alpha")) value = fq_pie_sysctl.pcfg.alpha; else value = fq_pie_sysctl.pcfg.beta; value = value * 1000 / PIE_SCALE; error = sysctl_handle_long(oidp, &value, 0, req); if (error != 0 || req->newptr == NULL) return (error); if (value < 1 || value > 7 * PIE_SCALE) return (EINVAL); value = (value * PIE_SCALE) / 1000; if (!strcmp(oidp->oid_name,"alpha")) fq_pie_sysctl.pcfg.alpha = value; else fq_pie_sysctl.pcfg.beta = value; return (0); } static int fqpie_sysctl_target_tupdate_maxb_handler(SYSCTL_HANDLER_ARGS) { int error; long value; if (!strcmp(oidp->oid_name,"target")) value = fq_pie_sysctl.pcfg.qdelay_ref; else if (!strcmp(oidp->oid_name,"tupdate")) value = fq_pie_sysctl.pcfg.tupdate; else value = fq_pie_sysctl.pcfg.max_burst; value = value / AQM_TIME_1US; error = sysctl_handle_long(oidp, &value, 0, req); if (error != 0 || req->newptr == NULL) return (error); if (value < 1 || value > 10 * AQM_TIME_1S) return (EINVAL); value = value * AQM_TIME_1US; if (!strcmp(oidp->oid_name,"target")) fq_pie_sysctl.pcfg.qdelay_ref = value; else if (!strcmp(oidp->oid_name,"tupdate")) fq_pie_sysctl.pcfg.tupdate = value; else fq_pie_sysctl.pcfg.max_burst = value; return (0); } static int fqpie_sysctl_max_ecnth_handler(SYSCTL_HANDLER_ARGS) { int error; long value; value = fq_pie_sysctl.pcfg.max_ecnth; value = value * 1000 / PIE_SCALE; error = sysctl_handle_long(oidp, &value, 0, req); if (error != 0 || req->newptr == NULL) return (error); if (value < 1 || value > PIE_SCALE) return (EINVAL); value = (value * PIE_SCALE) / 1000; fq_pie_sysctl.pcfg.max_ecnth = value; return (0); } /* define FQ- PIE sysctl variables */ SYSBEGIN(f4) SYSCTL_DECL(_net_inet); SYSCTL_DECL(_net_inet_ip); SYSCTL_DECL(_net_inet_ip_dummynet); static SYSCTL_NODE(_net_inet_ip_dummynet, OID_AUTO, fqpie, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, "FQ_PIE"); #ifdef SYSCTL_NODE SYSCTL_PROC(_net_inet_ip_dummynet_fqpie, OID_AUTO, target, CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0, fqpie_sysctl_target_tupdate_maxb_handler, "L", "queue target in microsecond"); SYSCTL_PROC(_net_inet_ip_dummynet_fqpie, OID_AUTO, tupdate, CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0, fqpie_sysctl_target_tupdate_maxb_handler, "L", "the frequency of drop probability calculation in microsecond"); SYSCTL_PROC(_net_inet_ip_dummynet_fqpie, OID_AUTO, max_burst, CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0, fqpie_sysctl_target_tupdate_maxb_handler, "L", "Burst allowance interval in microsecond"); SYSCTL_PROC(_net_inet_ip_dummynet_fqpie, OID_AUTO, max_ecnth, CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0, fqpie_sysctl_max_ecnth_handler, "L", "ECN safeguard threshold scaled by 1000"); SYSCTL_PROC(_net_inet_ip_dummynet_fqpie, OID_AUTO, alpha, CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0, fqpie_sysctl_alpha_beta_handler, "L", "PIE alpha scaled by 1000"); SYSCTL_PROC(_net_inet_ip_dummynet_fqpie, OID_AUTO, beta, CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0, fqpie_sysctl_alpha_beta_handler, "L", "beta scaled by 1000"); SYSCTL_UINT(_net_inet_ip_dummynet_fqpie, OID_AUTO, quantum, CTLFLAG_RW, &fq_pie_sysctl.quantum, 1514, "quantum for FQ_PIE"); SYSCTL_UINT(_net_inet_ip_dummynet_fqpie, OID_AUTO, flows, CTLFLAG_RW, &fq_pie_sysctl.flows_cnt, 1024, "Number of queues for FQ_PIE"); SYSCTL_UINT(_net_inet_ip_dummynet_fqpie, OID_AUTO, limit, CTLFLAG_RW, &fq_pie_sysctl.limit, 10240, "limit for FQ_PIE"); #endif /* Helper function to update queue&main-queue and scheduler statistics. * negative len & drop -> drop * negative len -> dequeue * positive len -> enqueue * positive len + drop -> drop during enqueue */ __inline static void fq_update_stats(struct fq_pie_flow *q, struct fq_pie_si *si, int len, int drop) { int inc = 0; if (len < 0) inc = -1; else if (len > 0) inc = 1; if (drop) { si->main_q.ni.drops ++; q->stats.drops ++; si->_si.ni.drops ++; V_dn_cfg.io_pkt_drop ++; } if (!drop || (drop && len < 0)) { /* Update stats for the main queue */ si->main_q.ni.length += inc; si->main_q.ni.len_bytes += len; /*update sub-queue stats */ q->stats.length += inc; q->stats.len_bytes += len; /*update scheduler instance stats */ si->_si.ni.length += inc; si->_si.ni.len_bytes += len; } if (inc > 0) { si->main_q.ni.tot_bytes += len; si->main_q.ni.tot_pkts ++; q->stats.tot_bytes +=len; q->stats.tot_pkts++; si->_si.ni.tot_bytes +=len; si->_si.ni.tot_pkts ++; } } /* * Extract a packet from the head of sub-queue 'q' * Return a packet or NULL if the queue is empty. * If getts is set, also extract packet's timestamp from mtag. */ __inline static struct mbuf * fq_pie_extract_head(struct fq_pie_flow *q, aqm_time_t *pkt_ts, struct fq_pie_si *si, int getts) { struct mbuf *m; next: m = q->mq.head; if (m == NULL) return m; q->mq.head = m->m_nextpkt; fq_update_stats(q, si, -m->m_pkthdr.len, 0); if (si->main_q.ni.length == 0) /* queue is now idle */ si->main_q.q_time = V_dn_cfg.curr_time; if (getts) { /* extract packet timestamp*/ struct m_tag *mtag; mtag = m_tag_locate(m, MTAG_ABI_COMPAT, DN_AQM_MTAG_TS, NULL); if (mtag == NULL){ D("PIE timestamp mtag not found!"); *pkt_ts = 0; } else { *pkt_ts = *(aqm_time_t *)(mtag + 1); m_tag_delete(m,mtag); } } if (m->m_pkthdr.rcvif != NULL && __predict_false(m_rcvif_restore(m) == NULL)) { m_freem(m); goto next; } return m; } /* * Callout function for drop probability calculation * This function is called over tupdate ms and takes pointer of FQ-PIE * flow as an argument */ static void fq_calculate_drop_prob(void *x) { struct fq_pie_flow *q = (struct fq_pie_flow *) x; struct pie_status *pst = &q->pst; struct dn_aqm_pie_parms *pprms; int64_t p, prob, oldprob; int p_isneg; pprms = pst->parms; prob = pst->drop_prob; /* calculate current qdelay using DRE method. * If TS is used and no data in the queue, reset current_qdelay * as it stays at last value during dequeue process. */ if (pprms->flags & PIE_DEPRATEEST_ENABLED) pst->current_qdelay = ((uint64_t)q->stats.len_bytes * pst->avg_dq_time) >> PIE_DQ_THRESHOLD_BITS; else if (!q->stats.len_bytes) pst->current_qdelay = 0; /* calculate drop probability */ p = (int64_t)pprms->alpha * ((int64_t)pst->current_qdelay - (int64_t)pprms->qdelay_ref); p +=(int64_t) pprms->beta * ((int64_t)pst->current_qdelay - (int64_t)pst->qdelay_old); /* take absolute value so right shift result is well defined */ p_isneg = p < 0; if (p_isneg) { p = -p; } /* We PIE_MAX_PROB shift by 12-bits to increase the division precision */ p *= (PIE_MAX_PROB << 12) / AQM_TIME_1S; /* auto-tune drop probability */ if (prob < (PIE_MAX_PROB / 1000000)) /* 0.000001 */ p >>= 11 + PIE_FIX_POINT_BITS + 12; else if (prob < (PIE_MAX_PROB / 100000)) /* 0.00001 */ p >>= 9 + PIE_FIX_POINT_BITS + 12; else if (prob < (PIE_MAX_PROB / 10000)) /* 0.0001 */ p >>= 7 + PIE_FIX_POINT_BITS + 12; else if (prob < (PIE_MAX_PROB / 1000)) /* 0.001 */ p >>= 5 + PIE_FIX_POINT_BITS + 12; else if (prob < (PIE_MAX_PROB / 100)) /* 0.01 */ p >>= 3 + PIE_FIX_POINT_BITS + 12; else if (prob < (PIE_MAX_PROB / 10)) /* 0.1 */ p >>= 1 + PIE_FIX_POINT_BITS + 12; else p >>= PIE_FIX_POINT_BITS + 12; oldprob = prob; if (p_isneg) { prob = prob - p; /* check for multiplication underflow */ if (prob > oldprob) { prob= 0; D("underflow"); } } else { /* Cap Drop adjustment */ if ((pprms->flags & PIE_CAPDROP_ENABLED) && prob >= PIE_MAX_PROB / 10 && p > PIE_MAX_PROB / 50 ) { p = PIE_MAX_PROB / 50; } prob = prob + p; /* check for multiplication overflow */ if (probcurrent_qdelay == 0 && pst->qdelay_old == 0) { /* 0.98 ~= 1- 1/64 */ prob = prob - (prob >> 6); } if (prob > PIE_MAX_PROB) { prob = PIE_MAX_PROB; } } pst->drop_prob = prob; /* store current delay value */ pst->qdelay_old = pst->current_qdelay; /* update burst allowance */ if ((pst->sflags & PIE_ACTIVE) && pst->burst_allowance) { if (pst->burst_allowance > pprms->tupdate) pst->burst_allowance -= pprms->tupdate; else pst->burst_allowance = 0; } if (pst->sflags & PIE_ACTIVE) callout_reset_sbt(&pst->aqm_pie_callout, (uint64_t)pprms->tupdate * SBT_1US, 0, fq_calculate_drop_prob, q, 0); mtx_unlock(&pst->lock_mtx); } /* * Reset PIE variables & activate the queue */ __inline static void fq_activate_pie(struct fq_pie_flow *q) { struct pie_status *pst = &q->pst; struct dn_aqm_pie_parms *pprms; mtx_lock(&pst->lock_mtx); pprms = pst->parms; pprms = pst->parms; pst->drop_prob = 0; pst->qdelay_old = 0; pst->burst_allowance = pprms->max_burst; pst->accu_prob = 0; pst->dq_count = 0; pst->avg_dq_time = 0; pst->sflags = PIE_INMEASUREMENT | PIE_ACTIVE; pst->measurement_start = AQM_UNOW; callout_reset_sbt(&pst->aqm_pie_callout, (uint64_t)pprms->tupdate * SBT_1US, 0, fq_calculate_drop_prob, q, 0); mtx_unlock(&pst->lock_mtx); } /* * Deactivate PIE and stop probe update callout */ __inline static void fq_deactivate_pie(struct pie_status *pst) { mtx_lock(&pst->lock_mtx); pst->sflags &= ~(PIE_ACTIVE | PIE_INMEASUREMENT); callout_stop(&pst->aqm_pie_callout); //D("PIE Deactivated"); mtx_unlock(&pst->lock_mtx); } /* * Initialize PIE for sub-queue 'q' */ static int pie_init(struct fq_pie_flow *q, struct fq_pie_schk *fqpie_schk) { struct pie_status *pst=&q->pst; struct dn_aqm_pie_parms *pprms = pst->parms; int err = 0; if (!pprms){ D("AQM_PIE is not configured"); err = EINVAL; } else { q->psi_extra->nr_active_q++; /* For speed optimization, we caculate 1/3 queue size once here */ // XXX limit divided by number of queues divided by 3 ??? pst->one_third_q_size = (fqpie_schk->cfg.limit / fqpie_schk->cfg.flows_cnt) / 3; mtx_init(&pst->lock_mtx, "mtx_pie", NULL, MTX_DEF); callout_init_mtx(&pst->aqm_pie_callout, &pst->lock_mtx, CALLOUT_RETURNUNLOCKED); } return err; } /* * callout function to destroy PIE lock, and free fq_pie flows and fq_pie si * extra memory when number of active sub-queues reaches zero. * 'x' is a fq_pie_flow to be destroyed */ static void fqpie_callout_cleanup(void *x) { struct fq_pie_flow *q = x; struct pie_status *pst = &q->pst; struct fq_pie_si_extra *psi_extra; mtx_unlock(&pst->lock_mtx); mtx_destroy(&pst->lock_mtx); psi_extra = q->psi_extra; dummynet_sched_lock(); psi_extra->nr_active_q--; /* when all sub-queues are destroyed, free flows fq_pie extra vars memory */ if (!psi_extra->nr_active_q) { free(psi_extra->flows, M_DUMMYNET); free(psi_extra, M_DUMMYNET); fq_pie_desc.ref_count--; } dummynet_sched_unlock(); } /* * Clean up PIE status for sub-queue 'q' * Stop callout timer and destroy mtx using fqpie_callout_cleanup() callout. */ static int pie_cleanup(struct fq_pie_flow *q) { struct pie_status *pst = &q->pst; mtx_lock(&pst->lock_mtx); callout_reset_sbt(&pst->aqm_pie_callout, SBT_1US, 0, fqpie_callout_cleanup, q, 0); mtx_unlock(&pst->lock_mtx); return 0; } /* * Dequeue and return a pcaket from sub-queue 'q' or NULL if 'q' is empty. * Also, caculate depature time or queue delay using timestamp */ static struct mbuf * pie_dequeue(struct fq_pie_flow *q, struct fq_pie_si *si) { struct mbuf *m; struct dn_aqm_pie_parms *pprms; struct pie_status *pst; aqm_time_t now; aqm_time_t pkt_ts, dq_time; int32_t w; pst = &q->pst; pprms = q->pst.parms; /*we extarct packet ts only when Departure Rate Estimation dis not used*/ m = fq_pie_extract_head(q, &pkt_ts, si, !(pprms->flags & PIE_DEPRATEEST_ENABLED)); if (!m || !(pst->sflags & PIE_ACTIVE)) return m; now = AQM_UNOW; if (pprms->flags & PIE_DEPRATEEST_ENABLED) { /* calculate average depature time */ if(pst->sflags & PIE_INMEASUREMENT) { pst->dq_count += m->m_pkthdr.len; if (pst->dq_count >= PIE_DQ_THRESHOLD) { dq_time = now - pst->measurement_start; /* * if we don't have old avg dq_time i.e PIE is (re)initialized, * don't use weight to calculate new avg_dq_time */ if(pst->avg_dq_time == 0) pst->avg_dq_time = dq_time; else { /* * weight = PIE_DQ_THRESHOLD/2^6, but we scaled * weight by 2^8. Thus, scaled * weight = PIE_DQ_THRESHOLD /2^8 * */ w = PIE_DQ_THRESHOLD >> 8; pst->avg_dq_time = (dq_time* w + (pst->avg_dq_time * ((1L << 8) - w))) >> 8; pst->sflags &= ~PIE_INMEASUREMENT; } } } /* * Start new measurement cycle when the queue has * PIE_DQ_THRESHOLD worth of bytes. */ if(!(pst->sflags & PIE_INMEASUREMENT) && q->stats.len_bytes >= PIE_DQ_THRESHOLD) { pst->sflags |= PIE_INMEASUREMENT; pst->measurement_start = now; pst->dq_count = 0; } } /* Optionally, use packet timestamp to estimate queue delay */ else pst->current_qdelay = now - pkt_ts; return m; } /* * Enqueue a packet in q, subject to space and FQ-PIE queue management policy * (whose parameters are in q->fs). * Update stats for the queue and the scheduler. * Return 0 on success, 1 on drop. The packet is consumed anyways. */ static int pie_enqueue(struct fq_pie_flow *q, struct mbuf* m, struct fq_pie_si *si) { uint64_t len; struct pie_status *pst; struct dn_aqm_pie_parms *pprms; int t; len = m->m_pkthdr.len; pst = &q->pst; pprms = pst->parms; t = ENQUE; /* drop/mark the packet when PIE is active and burst time elapsed */ if (pst->sflags & PIE_ACTIVE && pst->burst_allowance == 0 && drop_early(pst, q->stats.len_bytes) == DROP) { /* * if drop_prob over ECN threshold, drop the packet * otherwise mark and enqueue it. */ if (pprms->flags & PIE_ECN_ENABLED && pst->drop_prob < (pprms->max_ecnth << (PIE_PROB_BITS - PIE_FIX_POINT_BITS)) && ecn_mark(m)) t = ENQUE; else t = DROP; } /* Turn PIE on when 1/3 of the queue is full */ if (!(pst->sflags & PIE_ACTIVE) && q->stats.len_bytes >= pst->one_third_q_size) { fq_activate_pie(q); } /* reset burst tolerance and optinally turn PIE off*/ if (pst->drop_prob == 0 && pst->current_qdelay < (pprms->qdelay_ref >> 1) && pst->qdelay_old < (pprms->qdelay_ref >> 1)) { pst->burst_allowance = pprms->max_burst; if (pprms->flags & PIE_ON_OFF_MODE_ENABLED && q->stats.len_bytes<=0) fq_deactivate_pie(pst); } /* Use timestamp if Departure Rate Estimation mode is disabled */ if (t != DROP && !(pprms->flags & PIE_DEPRATEEST_ENABLED)) { /* Add TS to mbuf as a TAG */ struct m_tag *mtag; mtag = m_tag_locate(m, MTAG_ABI_COMPAT, DN_AQM_MTAG_TS, NULL); if (mtag == NULL) mtag = m_tag_alloc(MTAG_ABI_COMPAT, DN_AQM_MTAG_TS, sizeof(aqm_time_t), M_NOWAIT); if (mtag == NULL) { t = DROP; } else { *(aqm_time_t *)(mtag + 1) = AQM_UNOW; m_tag_prepend(m, mtag); } } if (t != DROP) { if (m->m_pkthdr.rcvif != NULL) m_rcvif_serialize(m); mq_append(&q->mq, m); fq_update_stats(q, si, len, 0); return 0; } else { fq_update_stats(q, si, len, 1); pst->accu_prob = 0; FREE_PKT(m); return 1; } return 0; } /* Drop a packet form the head of FQ-PIE sub-queue */ static void pie_drop_head(struct fq_pie_flow *q, struct fq_pie_si *si) { struct mbuf *m = q->mq.head; if (m == NULL) return; q->mq.head = m->m_nextpkt; fq_update_stats(q, si, -m->m_pkthdr.len, 1); if (si->main_q.ni.length == 0) /* queue is now idle */ si->main_q.q_time = V_dn_cfg.curr_time; /* reset accu_prob after packet drop */ q->pst.accu_prob = 0; FREE_PKT(m); } /* * Classify a packet to queue number using Jenkins hash function. * Return: queue number * the input of the hash are protocol no, perturbation, src IP, dst IP, * src port, dst port, */ static inline int fq_pie_classify_flow(struct mbuf *m, uint16_t fcount, struct fq_pie_si *si) { struct ip *ip; struct tcphdr *th; struct udphdr *uh; uint8_t tuple[41]; uint16_t hash=0; ip = (struct ip *)mtodo(m, dn_tag_get(m)->iphdr_off); //#ifdef INET6 struct ip6_hdr *ip6; int isip6; isip6 = (ip->ip_v == 6); if(isip6) { ip6 = (struct ip6_hdr *)ip; *((uint8_t *) &tuple[0]) = ip6->ip6_nxt; *((uint32_t *) &tuple[1]) = si->perturbation; memcpy(&tuple[5], ip6->ip6_src.s6_addr, 16); memcpy(&tuple[21], ip6->ip6_dst.s6_addr, 16); switch (ip6->ip6_nxt) { case IPPROTO_TCP: th = (struct tcphdr *)(ip6 + 1); *((uint16_t *) &tuple[37]) = th->th_dport; *((uint16_t *) &tuple[39]) = th->th_sport; break; case IPPROTO_UDP: uh = (struct udphdr *)(ip6 + 1); *((uint16_t *) &tuple[37]) = uh->uh_dport; *((uint16_t *) &tuple[39]) = uh->uh_sport; break; default: memset(&tuple[37], 0, 4); } hash = jenkins_hash(tuple, 41, HASHINIT) % fcount; return hash; } //#endif /* IPv4 */ *((uint8_t *) &tuple[0]) = ip->ip_p; *((uint32_t *) &tuple[1]) = si->perturbation; *((uint32_t *) &tuple[5]) = ip->ip_src.s_addr; *((uint32_t *) &tuple[9]) = ip->ip_dst.s_addr; switch (ip->ip_p) { case IPPROTO_TCP: th = (struct tcphdr *)(ip + 1); *((uint16_t *) &tuple[13]) = th->th_dport; *((uint16_t *) &tuple[15]) = th->th_sport; break; case IPPROTO_UDP: uh = (struct udphdr *)(ip + 1); *((uint16_t *) &tuple[13]) = uh->uh_dport; *((uint16_t *) &tuple[15]) = uh->uh_sport; break; default: memset(&tuple[13], 0, 4); } hash = jenkins_hash(tuple, 17, HASHINIT) % fcount; return hash; } /* * Enqueue a packet into an appropriate queue according to * FQ-CoDe; algorithm. */ static int fq_pie_enqueue(struct dn_sch_inst *_si, struct dn_queue *_q, struct mbuf *m) { struct fq_pie_si *si; struct fq_pie_schk *schk; struct dn_sch_fq_pie_parms *param; struct dn_queue *mainq; struct fq_pie_flow *flows; int idx, drop, i, maxidx; mainq = (struct dn_queue *)(_si + 1); si = (struct fq_pie_si *)_si; flows = si->si_extra->flows; schk = (struct fq_pie_schk *)(si->_si.sched+1); param = &schk->cfg; /* classify a packet to queue number*/ idx = fq_pie_classify_flow(m, param->flows_cnt, si); /* enqueue packet into appropriate queue using PIE AQM. * Note: 'pie_enqueue' function returns 1 only when it unable to * add timestamp to packet (no limit check)*/ drop = pie_enqueue(&flows[idx], m, si); /* pie unable to timestamp a packet */ if (drop) return 1; /* If the flow (sub-queue) is not active ,then add it to tail of * new flows list, initialize and activate it. */ if (!flows[idx].active) { STAILQ_INSERT_TAIL(&si->newflows, &flows[idx], flowchain); flows[idx].deficit = param->quantum; fq_activate_pie(&flows[idx]); flows[idx].active = 1; } /* check the limit for all queues and remove a packet from the * largest one */ if (mainq->ni.length > schk->cfg.limit) { /* find first active flow */ for (maxidx = 0; maxidx < schk->cfg.flows_cnt; maxidx++) if (flows[maxidx].active) break; if (maxidx < schk->cfg.flows_cnt) { /* find the largest sub- queue */ for (i = maxidx + 1; i < schk->cfg.flows_cnt; i++) if (flows[i].active && flows[i].stats.length > flows[maxidx].stats.length) maxidx = i; pie_drop_head(&flows[maxidx], si); drop = 1; } } return drop; } /* * Dequeue a packet from an appropriate queue according to * FQ-CoDel algorithm. */ static struct mbuf * fq_pie_dequeue(struct dn_sch_inst *_si) { struct fq_pie_si *si; struct fq_pie_schk *schk; struct dn_sch_fq_pie_parms *param; struct fq_pie_flow *f; struct mbuf *mbuf; struct fq_pie_list *fq_pie_flowlist; si = (struct fq_pie_si *)_si; schk = (struct fq_pie_schk *)(si->_si.sched+1); param = &schk->cfg; do { /* select a list to start with */ if (STAILQ_EMPTY(&si->newflows)) fq_pie_flowlist = &si->oldflows; else fq_pie_flowlist = &si->newflows; /* Both new and old queue lists are empty, return NULL */ if (STAILQ_EMPTY(fq_pie_flowlist)) return NULL; f = STAILQ_FIRST(fq_pie_flowlist); while (f != NULL) { /* if there is no flow(sub-queue) deficit, increase deficit * by quantum, move the flow to the tail of old flows list * and try another flow. * Otherwise, the flow will be used for dequeue. */ if (f->deficit < 0) { f->deficit += param->quantum; STAILQ_REMOVE_HEAD(fq_pie_flowlist, flowchain); STAILQ_INSERT_TAIL(&si->oldflows, f, flowchain); } else break; f = STAILQ_FIRST(fq_pie_flowlist); } /* the new flows list is empty, try old flows list */ if (STAILQ_EMPTY(fq_pie_flowlist)) continue; /* Dequeue a packet from the selected flow */ mbuf = pie_dequeue(f, si); /* pie did not return a packet */ if (!mbuf) { /* If the selected flow belongs to new flows list, then move * it to the tail of old flows list. Otherwise, deactivate it and * remove it from the old list and */ if (fq_pie_flowlist == &si->newflows) { STAILQ_REMOVE_HEAD(fq_pie_flowlist, flowchain); STAILQ_INSERT_TAIL(&si->oldflows, f, flowchain); } else { f->active = 0; fq_deactivate_pie(&f->pst); STAILQ_REMOVE_HEAD(fq_pie_flowlist, flowchain); } /* start again */ continue; } /* we have a packet to return, * update flow deficit and return the packet*/ f->deficit -= mbuf->m_pkthdr.len; return mbuf; } while (1); /* unreachable point */ return NULL; } /* * Initialize fq_pie scheduler instance. * also, allocate memory for flows array. */ static int fq_pie_new_sched(struct dn_sch_inst *_si) { struct fq_pie_si *si; struct dn_queue *q; struct fq_pie_schk *schk; struct fq_pie_flow *flows; int i; si = (struct fq_pie_si *)_si; schk = (struct fq_pie_schk *)(_si->sched+1); if(si->si_extra) { D("si already configured!"); return 0; } /* init the main queue */ q = &si->main_q; set_oid(&q->ni.oid, DN_QUEUE, sizeof(*q)); q->_si = _si; q->fs = _si->sched->fs; /* allocate memory for scheduler instance extra vars */ si->si_extra = malloc(sizeof(struct fq_pie_si_extra), M_DUMMYNET, M_NOWAIT | M_ZERO); if (si->si_extra == NULL) { D("cannot allocate memory for fq_pie si extra vars"); return ENOMEM ; } /* allocate memory for flows array */ si->si_extra->flows = mallocarray(schk->cfg.flows_cnt, sizeof(struct fq_pie_flow), M_DUMMYNET, M_NOWAIT | M_ZERO); flows = si->si_extra->flows; if (flows == NULL) { free(si->si_extra, M_DUMMYNET); si->si_extra = NULL; D("cannot allocate memory for fq_pie flows"); return ENOMEM ; } /* init perturbation for this si */ si->perturbation = random(); si->si_extra->nr_active_q = 0; /* init the old and new flows lists */ STAILQ_INIT(&si->newflows); STAILQ_INIT(&si->oldflows); /* init the flows (sub-queues) */ for (i = 0; i < schk->cfg.flows_cnt; i++) { flows[i].pst.parms = &schk->cfg.pcfg; flows[i].psi_extra = si->si_extra; pie_init(&flows[i], schk); } dummynet_sched_lock(); fq_pie_desc.ref_count++; dummynet_sched_unlock(); return 0; } /* * Free fq_pie scheduler instance. */ static int fq_pie_free_sched(struct dn_sch_inst *_si) { struct fq_pie_si *si; struct fq_pie_schk *schk; struct fq_pie_flow *flows; int i; si = (struct fq_pie_si *)_si; schk = (struct fq_pie_schk *)(_si->sched+1); flows = si->si_extra->flows; for (i = 0; i < schk->cfg.flows_cnt; i++) { pie_cleanup(&flows[i]); } si->si_extra = NULL; return 0; } /* * Configure FQ-PIE scheduler. * the configurations for the scheduler is passed fromipfw userland. */ static int fq_pie_config(struct dn_schk *_schk) { struct fq_pie_schk *schk; struct dn_extra_parms *ep; struct dn_sch_fq_pie_parms *fqp_cfg; schk = (struct fq_pie_schk *)(_schk+1); ep = (struct dn_extra_parms *) _schk->cfg; /* par array contains fq_pie configuration as follow * PIE: 0- qdelay_ref,1- tupdate, 2- max_burst * 3- max_ecnth, 4- alpha, 5- beta, 6- flags * FQ_PIE: 7- quantum, 8- limit, 9- flows */ if (ep && ep->oid.len ==sizeof(*ep) && ep->oid.subtype == DN_SCH_PARAMS) { fqp_cfg = &schk->cfg; if (ep->par[0] < 0) fqp_cfg->pcfg.qdelay_ref = fq_pie_sysctl.pcfg.qdelay_ref; else fqp_cfg->pcfg.qdelay_ref = ep->par[0]; if (ep->par[1] < 0) fqp_cfg->pcfg.tupdate = fq_pie_sysctl.pcfg.tupdate; else fqp_cfg->pcfg.tupdate = ep->par[1]; if (ep->par[2] < 0) fqp_cfg->pcfg.max_burst = fq_pie_sysctl.pcfg.max_burst; else fqp_cfg->pcfg.max_burst = ep->par[2]; if (ep->par[3] < 0) fqp_cfg->pcfg.max_ecnth = fq_pie_sysctl.pcfg.max_ecnth; else fqp_cfg->pcfg.max_ecnth = ep->par[3]; if (ep->par[4] < 0) fqp_cfg->pcfg.alpha = fq_pie_sysctl.pcfg.alpha; else fqp_cfg->pcfg.alpha = ep->par[4]; if (ep->par[5] < 0) fqp_cfg->pcfg.beta = fq_pie_sysctl.pcfg.beta; else fqp_cfg->pcfg.beta = ep->par[5]; if (ep->par[6] < 0) fqp_cfg->pcfg.flags = 0; else fqp_cfg->pcfg.flags = ep->par[6]; /* FQ configurations */ if (ep->par[7] < 0) fqp_cfg->quantum = fq_pie_sysctl.quantum; else fqp_cfg->quantum = ep->par[7]; if (ep->par[8] < 0) fqp_cfg->limit = fq_pie_sysctl.limit; else fqp_cfg->limit = ep->par[8]; if (ep->par[9] < 0) fqp_cfg->flows_cnt = fq_pie_sysctl.flows_cnt; else fqp_cfg->flows_cnt = ep->par[9]; /* Bound the configurations */ fqp_cfg->pcfg.qdelay_ref = BOUND_VAR(fqp_cfg->pcfg.qdelay_ref, 1, 5 * AQM_TIME_1S); fqp_cfg->pcfg.tupdate = BOUND_VAR(fqp_cfg->pcfg.tupdate, 1, 5 * AQM_TIME_1S); fqp_cfg->pcfg.max_burst = BOUND_VAR(fqp_cfg->pcfg.max_burst, 0, 5 * AQM_TIME_1S); fqp_cfg->pcfg.max_ecnth = BOUND_VAR(fqp_cfg->pcfg.max_ecnth, 0, PIE_SCALE); fqp_cfg->pcfg.alpha = BOUND_VAR(fqp_cfg->pcfg.alpha, 0, 7 * PIE_SCALE); fqp_cfg->pcfg.beta = BOUND_VAR(fqp_cfg->pcfg.beta, 0, 7 * PIE_SCALE); fqp_cfg->quantum = BOUND_VAR(fqp_cfg->quantum,1,9000); fqp_cfg->limit= BOUND_VAR(fqp_cfg->limit,1,20480); fqp_cfg->flows_cnt= BOUND_VAR(fqp_cfg->flows_cnt,1,65536); } else { D("Wrong parameters for fq_pie scheduler"); return 1; } return 0; } /* * Return FQ-PIE scheduler configurations * the configurations for the scheduler is passed to userland. */ static int fq_pie_getconfig (struct dn_schk *_schk, struct dn_extra_parms *ep) { struct fq_pie_schk *schk = (struct fq_pie_schk *)(_schk+1); struct dn_sch_fq_pie_parms *fqp_cfg; fqp_cfg = &schk->cfg; strcpy(ep->name, fq_pie_desc.name); ep->par[0] = fqp_cfg->pcfg.qdelay_ref; ep->par[1] = fqp_cfg->pcfg.tupdate; ep->par[2] = fqp_cfg->pcfg.max_burst; ep->par[3] = fqp_cfg->pcfg.max_ecnth; ep->par[4] = fqp_cfg->pcfg.alpha; ep->par[5] = fqp_cfg->pcfg.beta; ep->par[6] = fqp_cfg->pcfg.flags; ep->par[7] = fqp_cfg->quantum; ep->par[8] = fqp_cfg->limit; ep->par[9] = fqp_cfg->flows_cnt; return 0; } /* * FQ-PIE scheduler descriptor * contains the type of the scheduler, the name, the size of extra * data structures, and function pointers. */ static struct dn_alg fq_pie_desc = { _SI( .type = ) DN_SCHED_FQ_PIE, _SI( .name = ) "FQ_PIE", _SI( .flags = ) 0, _SI( .schk_datalen = ) sizeof(struct fq_pie_schk), _SI( .si_datalen = ) sizeof(struct fq_pie_si) - sizeof(struct dn_sch_inst), _SI( .q_datalen = ) 0, _SI( .enqueue = ) fq_pie_enqueue, _SI( .dequeue = ) fq_pie_dequeue, _SI( .config = ) fq_pie_config, /* new sched i.e. sched X config ...*/ _SI( .destroy = ) NULL, /*sched x delete */ _SI( .new_sched = ) fq_pie_new_sched, /* new schd instance */ _SI( .free_sched = ) fq_pie_free_sched, /* delete schd instance */ _SI( .new_fsk = ) NULL, _SI( .free_fsk = ) NULL, _SI( .new_queue = ) NULL, _SI( .free_queue = ) NULL, _SI( .getconfig = ) fq_pie_getconfig, _SI( .ref_count = ) 0 }; DECLARE_DNSCHED_MODULE(dn_fq_pie, &fq_pie_desc);