+++ /dev/null
-/*
- * Copyright (c) 2007-2012 Apple Inc. All rights reserved.
- *
- * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. The rights granted to you under the License
- * may not be used to create, or enable the creation or redistribution of,
- * unlawful or unlicensed copies of an Apple operating system, or to
- * circumvent, violate, or enable the circumvention or violation of, any
- * terms of an Apple operating system software license agreement.
- *
- * Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
- */
-
-/* $OpenBSD: altq_red.c,v 1.14 2007/09/13 20:40:02 chl Exp $ */
-/* $KAME: altq_red.c,v 1.10 2002/04/03 05:38:51 kjc Exp $ */
-
-/*
- * Copyright (C) 1997-2003
- * Sony Computer Science Laboratories Inc. All rights reserved.
- *
- * 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 SONY CSL 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 SONY CSL 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.
- *
- */
-/*
- * Copyright (c) 1990-1994 Regents of the University of California.
- * All rights reserved.
- *
- * 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.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the Computer Systems
- * Engineering Group at Lawrence Berkeley Laboratory.
- * 4. Neither the name of the University nor of the Laboratory may be used
- * to endorse or promote products derived from this software without
- * specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
- */
-
-#include <sys/cdefs.h>
-
-#if CLASSQ_RED
-
-#include <sys/param.h>
-#include <sys/malloc.h>
-#include <sys/mbuf.h>
-#include <sys/socket.h>
-#include <sys/systm.h>
-#include <sys/syslog.h>
-#include <sys/errno.h>
-#include <sys/kauth.h>
-#include <dev/random/randomdev.h>
-#include <kern/zalloc.h>
-
-#include <net/if.h>
-
-#include <netinet/in.h>
-#include <netinet/in_systm.h>
-#include <netinet/ip.h>
-#if INET6
-#include <netinet/ip6.h>
-#endif
-
-#include <net/classq/classq_red.h>
-#include <net/net_osdep.h>
-
-/*
- * ALTQ/RED (Random Early Detection) implementation using 32-bit
- * fixed-point calculation.
- *
- * written by kjc using the ns code as a reference.
- * you can learn more about red and ns from Sally's home page at
- * http://www-nrg.ee.lbl.gov/floyd/
- *
- * most of the red parameter values are fixed in this implementation
- * to prevent fixed-point overflow/underflow.
- * if you change the parameters, watch out for overflow/underflow!
- *
- * the parameters used are recommended values by Sally.
- * the corresponding ns config looks:
- * q_weight=0.00195
- * minthresh=5 maxthresh=15 queue-size=60
- * linterm=30
- * dropmech=drop-tail
- * bytes=false (can't be handled by 32-bit fixed-point)
- * doubleq=false dqthresh=false
- * wait=true
- */
-/*
- * alternative red parameters for a slow link.
- *
- * assume the queue length becomes from zero to L and keeps L, it takes
- * N packets for q_avg to reach 63% of L.
- * when q_weight is 0.002, N is about 500 packets.
- * for a slow link like dial-up, 500 packets takes more than 1 minute!
- * when q_weight is 0.008, N is about 127 packets.
- * when q_weight is 0.016, N is about 63 packets.
- * bursts of 50 packets are allowed for 0.002, bursts of 25 packets
- * are allowed for 0.016.
- * see Sally's paper for more details.
- */
-/* normal red parameters */
-#define W_WEIGHT 512 /* inverse of weight of EWMA (511/512) */
- /* q_weight = 0.00195 */
-
-/* red parameters for a slow link */
-#define W_WEIGHT_1 128 /* inverse of weight of EWMA (127/128) */
- /* q_weight = 0.0078125 */
-
-/* red parameters for a very slow link (e.g., dialup) */
-#define W_WEIGHT_2 64 /* inverse of weight of EWMA (63/64) */
- /* q_weight = 0.015625 */
-
-/* fixed-point uses 12-bit decimal places */
-#define FP_SHIFT 12 /* fixed-point shift */
-
-/* red parameters for drop probability */
-#define INV_P_MAX 10 /* inverse of max drop probability */
-#define TH_MIN 5 /* min threshold */
-#define TH_MAX 15 /* max threshold */
-
-#define RED_LIMIT 60 /* default max queue lenght */
-
-#define RED_ZONE_MAX 32 /* maximum elements in zone */
-#define RED_ZONE_NAME "classq_red" /* zone name */
-
-static unsigned int red_size; /* size of zone element */
-static struct zone *red_zone; /* zone for red */
-
-/*
- * our default policy for forced-drop is drop-tail.
- * (in altq-1.1.2 or earlier, the default was random-drop.
- * but it makes more sense to punish the cause of the surge.)
- * to switch to the random-drop policy, define "RED_RANDOM_DROP".
- */
-
-/* default red parameter values */
-static int default_th_min = TH_MIN;
-static int default_th_max = TH_MAX;
-static int default_inv_pmax = INV_P_MAX;
-
-static struct mbuf *red_getq_flow(struct red *, class_queue_t *,
- u_int32_t, boolean_t);
-
-void
-red_init(void)
-{
- _CASSERT(REDF_ECN4 == CLASSQF_ECN4);
- _CASSERT(REDF_ECN6 == CLASSQF_ECN6);
-
- red_size = sizeof (red_t);
- red_zone = zinit(red_size, RED_ZONE_MAX * red_size,
- 0, RED_ZONE_NAME);
- if (red_zone == NULL) {
- panic("%s: failed allocating %s", __func__, RED_ZONE_NAME);
- /* NOTREACHED */
- }
- zone_change(red_zone, Z_EXPAND, TRUE);
- zone_change(red_zone, Z_CALLERACCT, TRUE);
-}
-
-/*
- * red support routines
- */
-red_t *
-red_alloc(struct ifnet *ifp, int weight, int inv_pmax, int th_min,
- int th_max, int flags, int pkttime)
-{
- red_t *rp;
- int w, i;
- int npkts_per_sec;
-
- VERIFY(ifp != NULL);
-
- rp = zalloc(red_zone);
- if (rp == NULL)
- return (NULL);
-
- bzero(rp, red_size);
- rp->red_avg = 0;
- rp->red_idle = 1;
-
- if (weight == 0)
- rp->red_weight = W_WEIGHT;
- else
- rp->red_weight = weight;
- if (inv_pmax == 0)
- rp->red_inv_pmax = default_inv_pmax;
- else
- rp->red_inv_pmax = inv_pmax;
- if (th_min == 0)
- rp->red_thmin = default_th_min;
- else
- rp->red_thmin = th_min;
- if (th_max == 0)
- rp->red_thmax = default_th_max;
- else
- rp->red_thmax = th_max;
-
- rp->red_ifp = ifp;
- rp->red_flags = (flags & REDF_USERFLAGS);
-#if !PF_ECN
- if (rp->red_flags & REDF_ECN) {
- rp->red_flags &= ~REDF_ECN;
- log(LOG_ERR, "%s: RED ECN not available; ignoring "
- "REDF_ECN flag!\n", if_name(ifp));
- }
-#endif /* !PF_ECN */
-
- if (pkttime == 0)
- /* default packet time: 1000 bytes / 10Mbps * 8 * 1000000 */
- rp->red_pkttime = 800;
- else
- rp->red_pkttime = pkttime;
-
- if (weight == 0) {
- /* when the link is very slow, adjust red parameters */
- npkts_per_sec = 1000000 / rp->red_pkttime;
- if (npkts_per_sec < 50) {
- /* up to about 400Kbps */
- rp->red_weight = W_WEIGHT_2;
- } else if (npkts_per_sec < 300) {
- /* up to about 2.4Mbps */
- rp->red_weight = W_WEIGHT_1;
- }
- }
-
- /* calculate wshift. weight must be power of 2 */
- w = rp->red_weight;
- for (i = 0; w > 1; i++)
- w = w >> 1;
- rp->red_wshift = i;
- w = 1 << rp->red_wshift;
- if (w != rp->red_weight) {
- printf("invalid weight value %d for red! use %d\n",
- rp->red_weight, w);
- rp->red_weight = w;
- }
-
- /*
- * thmin_s and thmax_s are scaled versions of th_min and th_max
- * to be compared with avg.
- */
- rp->red_thmin_s = rp->red_thmin << (rp->red_wshift + FP_SHIFT);
- rp->red_thmax_s = rp->red_thmax << (rp->red_wshift + FP_SHIFT);
-
- /*
- * precompute probability denominator
- * probd = (2 * (TH_MAX-TH_MIN) / pmax) in fixed-point
- */
- rp->red_probd = (2 * (rp->red_thmax - rp->red_thmin) *
- rp->red_inv_pmax) << FP_SHIFT;
-
- /* allocate weight table */
- rp->red_wtab = wtab_alloc(rp->red_weight);
- if (rp->red_wtab == NULL) {
- red_destroy(rp);
- return (NULL);
- }
-
- microuptime(&rp->red_last);
- return (rp);
-}
-
-void
-red_destroy(red_t *rp)
-{
- if (rp->red_wtab != NULL) {
- wtab_destroy(rp->red_wtab);
- rp->red_wtab = NULL;
- }
- zfree(red_zone, rp);
-}
-
-void
-red_getstats(red_t *rp, struct red_stats *sp)
-{
- sp->q_avg = rp->red_avg >> rp->red_wshift;
- sp->drop_forced = rp->red_stats.drop_forced;
- sp->drop_unforced = rp->red_stats.drop_unforced;
- sp->marked_packets = rp->red_stats.marked_packets;
-}
-
-int
-red_addq(red_t *rp, class_queue_t *q, struct mbuf *m, struct pf_mtag *tag)
-{
-#if !PF_ECN
-#pragma unused(tag)
-#endif /* !PF_ECN */
- int avg, droptype;
- int n;
-
- avg = rp->red_avg;
-
- /*
- * if we were idle, we pretend that n packets arrived during
- * the idle period.
- */
- if (rp->red_idle) {
- struct timeval now;
- int t;
-
- rp->red_idle = 0;
- microuptime(&now);
- t = (now.tv_sec - rp->red_last.tv_sec);
- if (t > 60) {
- /*
- * being idle for more than 1 minute, set avg to zero.
- * this prevents t from overflow.
- */
- avg = 0;
- } else {
- t = t * 1000000 + (now.tv_usec - rp->red_last.tv_usec);
- n = t / rp->red_pkttime - 1;
-
- /* the following line does (avg = (1 - Wq)^n * avg) */
- if (n > 0)
- avg = (avg >> FP_SHIFT) *
- pow_w(rp->red_wtab, n);
- }
- }
-
- /* run estimator. (note: avg is scaled by WEIGHT in fixed-point) */
- avg += (qlen(q) << FP_SHIFT) - (avg >> rp->red_wshift);
- rp->red_avg = avg; /* save the new value */
-
- /*
- * red_count keeps a tally of arriving traffic that has not
- * been dropped.
- */
- rp->red_count++;
-
- /* see if we drop early */
- droptype = DTYPE_NODROP;
- if (avg >= rp->red_thmin_s && qlen(q) > 1) {
- if (avg >= rp->red_thmax_s) {
- /* avg >= th_max: forced drop */
- droptype = DTYPE_FORCED;
- } else if (rp->red_old == 0) {
- /* first exceeds th_min */
- rp->red_count = 1;
- rp->red_old = 1;
- } else if (drop_early((avg - rp->red_thmin_s) >> rp->red_wshift,
- rp->red_probd, rp->red_count)) {
- /* mark or drop by red */
-#if PF_ECN
- if ((rp->red_flags & REDF_ECN) &&
- (tag->pftag_proto == IPPROTO_TCP) && /* only TCP */
- mark_ecn(m, tag, rp->red_flags)) {
- /* successfully marked. do not drop. */
- rp->red_count = 0;
- rp->red_stats.marked_packets++;
- } else
-#endif /* PF_ECN */
- {
- /* unforced drop by red */
- droptype = DTYPE_EARLY;
- }
- }
- } else {
- /* avg < th_min */
- rp->red_old = 0;
- }
-
- /*
- * if the queue length hits the hard limit, it's a forced drop.
- */
- if (droptype == DTYPE_NODROP && qlen(q) >= qlimit(q))
- droptype = DTYPE_FORCED;
-
-#ifdef RED_RANDOM_DROP
- /* if successful or forced drop, enqueue this packet. */
- if (droptype != DTYPE_EARLY)
- _addq(q, m);
-#else
- /* if successful, enqueue this packet. */
- if (droptype == DTYPE_NODROP)
- _addq(q, m);
-#endif
- if (droptype != DTYPE_NODROP) {
- if (droptype == DTYPE_EARLY) {
- /* drop the incoming packet */
- rp->red_stats.drop_unforced++;
- } else {
- /* forced drop, select a victim packet in the queue. */
-#ifdef RED_RANDOM_DROP
- m = _getq_random(q);
-#endif
- rp->red_stats.drop_forced++;
- }
- rp->red_count = 0;
- IFCQ_CONVERT_LOCK(&rp->red_ifp->if_snd);
- m_freem(m);
- return (CLASSQEQ_DROPPED);
- }
- /* successfully queued */
- return (CLASSQEQ_SUCCESS);
-}
-
-/*
- * early-drop probability is calculated as follows:
- * prob = p_max * (avg - th_min) / (th_max - th_min)
- * prob_a = prob / (2 - count*prob)
- * = (avg-th_min) / (2*(th_max-th_min)*inv_p_max - count*(avg-th_min))
- * here prob_a increases as successive undrop count increases.
- * (prob_a starts from prob/2, becomes prob when (count == (1 / prob)),
- * becomes 1 when (count >= (2 / prob))).
- */
-int
-drop_early(int fp_len, int fp_probd, int count)
-{
- int d; /* denominator of drop-probability */
-
- d = fp_probd - count * fp_len;
- if (d <= 0)
- /* count exceeds the hard limit: drop or mark */
- return (1);
-
- /*
- * now the range of d is [1..600] in fixed-point. (when
- * th_max-th_min=10 and p_max=1/30)
- * drop probability = (avg - TH_MIN) / d
- */
-
- if ((RandomULong() % d) < (unsigned)fp_len) {
- /* drop or mark */
- return (1);
- }
- /* no drop/mark */
- return (0);
-}
-
-static struct mbuf *
-red_getq_flow(struct red *rp, class_queue_t *q, u_int32_t flow, boolean_t purge)
-{
-#pragma unused(purge)
- struct mbuf *m;
-
- /* flow of 0 means head of queue */
- if ((m = ((flow == 0) ? _getq(q) : _getq_flow(q, flow))) == NULL) {
- if (rp->red_idle == 0) {
- rp->red_idle = 1;
- microuptime(&rp->red_last);
- }
- return (NULL);
- }
-
- rp->red_idle = 0;
- return (m);
-}
-
-struct mbuf *
-red_getq(red_t *rp, class_queue_t *q)
-{
- return (red_getq_flow(rp, q, 0, FALSE));
-}
-
-void
-red_purgeq(struct red *rp, class_queue_t *q, u_int32_t flow, u_int32_t *packets,
- u_int32_t *bytes)
-{
- u_int32_t cnt = 0, len = 0;
- struct mbuf *m;
-
- IFCQ_CONVERT_LOCK(&rp->red_ifp->if_snd);
-
- while ((m = red_getq_flow(rp, q, flow, TRUE)) != NULL) {
- cnt++;
- len += m_pktlen(m);
- m_freem(m);
- }
-
- if (packets != NULL)
- *packets = cnt;
- if (bytes != NULL)
- *bytes = len;
-}
-
-void
-red_updateq(red_t *rp, cqev_t ev)
-{
-#pragma unused(rp, ev)
- /* nothing for now */
-}
-
-int
-red_suspendq(red_t *rp, class_queue_t *q, boolean_t on)
-{
-#pragma unused(rp, q, on)
- return (ENOTSUP);
-}
-
-/*
- * helper routine to calibrate avg during idle.
- * pow_w(wtab, n) returns (1 - Wq)^n in fixed-point
- * here Wq = 1/weight and the code assumes Wq is close to zero.
- *
- * w_tab[n] holds ((1 - Wq)^(2^n)) in fixed-point.
- */
-static struct wtab *wtab_list = NULL; /* pointer to wtab list */
-
-struct wtab *
-wtab_alloc(int weight)
-{
- struct wtab *w;
- int i;
-
- for (w = wtab_list; w != NULL; w = w->w_next)
- if (w->w_weight == weight) {
- w->w_refcount++;
- return (w);
- }
-
- w = _MALLOC(sizeof (struct wtab), M_DEVBUF, M_WAITOK|M_ZERO);
- if (w == NULL)
- return (NULL);
-
- w->w_weight = weight;
- w->w_refcount = 1;
- w->w_next = wtab_list;
- wtab_list = w;
-
- /* initialize the weight table */
- w->w_tab[0] = ((weight - 1) << FP_SHIFT) / weight;
- for (i = 1; i < 32; i++) {
- w->w_tab[i] = (w->w_tab[i-1] * w->w_tab[i-1]) >> FP_SHIFT;
- if (w->w_tab[i] == 0 && w->w_param_max == 0)
- w->w_param_max = 1 << i;
- }
-
- return (w);
-}
-
-void
-wtab_destroy(struct wtab *w)
-{
- struct wtab *prev;
-
- if (--w->w_refcount > 0)
- return;
-
- if (wtab_list == w)
- wtab_list = w->w_next;
- else for (prev = wtab_list; prev->w_next != NULL; prev = prev->w_next)
- if (prev->w_next == w) {
- prev->w_next = w->w_next;
- break;
- }
-
- _FREE(w, M_DEVBUF);
-}
-
-int32_t
-pow_w(struct wtab *w, int n)
-{
- int i, bit;
- int32_t val;
-
- if (n >= w->w_param_max)
- return (0);
-
- val = 1 << FP_SHIFT;
- if (n <= 0)
- return (val);
-
- bit = 1;
- i = 0;
- while (n) {
- if (n & bit) {
- val = (val * w->w_tab[i]) >> FP_SHIFT;
- n &= ~bit;
- }
- i++;
- bit <<= 1;
- }
- return (val);
-}
-
-#endif /* CLASSQ_RED */
projects / apple / xnu.git / blobdiff