diff options
Diffstat (limited to 'freebsd/sys/netpfil/ipfw/dn_sched_fq_codel_helper.h')
| -rw-r--r-- | freebsd/sys/netpfil/ipfw/dn_sched_fq_codel_helper.h | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/freebsd/sys/netpfil/ipfw/dn_sched_fq_codel_helper.h b/freebsd/sys/netpfil/ipfw/dn_sched_fq_codel_helper.h new file mode 100644 index 00000000..da663dc8 --- /dev/null +++ b/freebsd/sys/netpfil/ipfw/dn_sched_fq_codel_helper.h @@ -0,0 +1,187 @@ +/* + * Codel - The Controlled-Delay Active Queue Management 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> + * + * Copyright (C) 2011-2014 Kathleen Nichols <nichols@pollere.com>. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * o Redistributions of source code must retain the above copyright + * notice, this list of conditions, and the following disclaimer, + * without modification. + * + * o 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. + * + * o The names of the authors may not be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * Alternatively, provided that this notice is retained in full, this + * software may be distributed under the terms of the GNU General Public + * License ("GPL") version 2, in which case the provisions of the GPL + * apply INSTEAD OF those given above. + + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT + * OWNER 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_SCHED_FQ_CODEL_HELPER_H +#define _IP_DN_SCHED_FQ_CODEL_HELPER_H + +__inline static struct mbuf * +fqc_dodequeue(struct fq_codel_flow *q, aqm_time_t now, uint16_t *ok_to_drop, + struct fq_codel_si *si) +{ + struct mbuf * m; + struct fq_codel_schk *schk = (struct fq_codel_schk *)(si->_si.sched+1); + aqm_time_t pkt_ts, sojourn_time; + + *ok_to_drop = 0; + m = fq_codel_extract_head(q, &pkt_ts, si); + + if (m == NULL) { + /*queue is empty - we can't be above target*/ + q->cst.first_above_time= 0; + return m; + } + + /* To span a large range of bandwidths, CoDel runs two + * different AQMs in parallel. One is sojourn-time-based + * and takes effect when the time to send an MTU-sized + * packet is less than target. The 1st term of the "if" + * below does this. The other is backlog-based and takes + * effect when the time to send an MTU-sized packet is >= + * target. The goal here is to keep the output link + * utilization high by never allowing the queue to get + * smaller than the amount that arrives in a typical + * interarrival time (MTU-sized packets arriving spaced + * by the amount of time it takes to send such a packet on + * the bottleneck). The 2nd term of the "if" does this. + */ + sojourn_time = now - pkt_ts; + if (sojourn_time < schk->cfg.ccfg.target || q->stats.len_bytes <= q->cst.maxpkt_size) { + /* went below - stay below for at least interval */ + q->cst.first_above_time = 0; + } else { + if (q->cst.first_above_time == 0) { + /* just went above from below. if still above at + * first_above_time, will say it's ok to drop. */ + q->cst.first_above_time = now + schk->cfg.ccfg.interval; + } else if (now >= q->cst.first_above_time) { + *ok_to_drop = 1; + } + } + return m; +} + +/* Codel dequeue function */ +__inline static struct mbuf * +fqc_codel_dequeue(struct fq_codel_flow *q, struct fq_codel_si *si) +{ + struct mbuf *m; + struct dn_aqm_codel_parms *cprms; + struct codel_status *cst; + aqm_time_t now; + uint16_t ok_to_drop; + struct fq_codel_schk *schk = (struct fq_codel_schk *)(si->_si.sched+1); + + cst = &q->cst; + cprms = &schk->cfg.ccfg; + + now = AQM_UNOW; + m = fqc_dodequeue(q, now, &ok_to_drop, si); + + if (cst->dropping) { + if (!ok_to_drop) { + /* sojourn time below target - leave dropping state */ + cst->dropping = false; + } + + /* Time for the next drop. Drop current packet and dequeue + * next. If the dequeue doesn't take us out of dropping + * state, schedule the next drop. A large backlog might + * result in drop rates so high that the next drop should + * happen now, hence the 'while' loop. + */ + while (now >= cst->drop_next_time && cst->dropping) { + + /* mark the packet */ + if (cprms->flags & CODEL_ECN_ENABLED && ecn_mark(m)) { + cst->count++; + /* schedule the next mark. */ + cst->drop_next_time = control_law(cst, cprms, cst->drop_next_time); + return m; + } + + /* drop the packet */ + fq_update_stats(q, si, 0, 1); + m_freem(m); + m = fqc_dodequeue(q, now, &ok_to_drop, si); + + if (!ok_to_drop) { + /* leave dropping state */ + cst->dropping = false; + } else { + cst->count++; + /* schedule the next drop. */ + cst->drop_next_time = control_law(cst, cprms, cst->drop_next_time); + } + } + /* If we get here we're not in dropping state. The 'ok_to_drop' + * return from dodequeue means that the sojourn time has been + * above 'target' for 'interval' so enter dropping state. + */ + } else if (ok_to_drop) { + + /* if ECN option is disabled or the packet cannot be marked, + * drop the packet and extract another. + */ + if (!(cprms->flags & CODEL_ECN_ENABLED) || !ecn_mark(m)) { + fq_update_stats(q, si, 0, 1); + m_freem(m); + m = fqc_dodequeue(q, now, &ok_to_drop,si); + } + + cst->dropping = true; + + /* If min went above target close to when it last went + * below, assume that the drop rate that controlled the + * queue on the last cycle is a good starting point to + * control it now. ('drop_next' will be at most 'interval' + * later than the time of the last drop so 'now - drop_next' + * is a good approximation of the time from the last drop + * until now.) + */ + cst->count = (cst->count > 2 && ((aqm_stime_t)now - + (aqm_stime_t)cst->drop_next_time) < 8* cprms->interval)? cst->count - 2 : 1; + + /* we don't have to set initial guess for Newton's method isqrt as + * we initilaize isqrt in control_law function when count == 1 */ + cst->drop_next_time = control_law(cst, cprms, now); + } + + return m; +} + +#endif |