diff options
Diffstat (limited to 'sys/contrib/altq/altq/altq_red.c')
-rw-r--r-- | sys/contrib/altq/altq/altq_red.c | 1505 |
1 files changed, 1505 insertions, 0 deletions
diff --git a/sys/contrib/altq/altq/altq_red.c b/sys/contrib/altq/altq/altq_red.c new file mode 100644 index 0000000..6010033 --- /dev/null +++ b/sys/contrib/altq/altq/altq_red.c @@ -0,0 +1,1505 @@ +/* $FreeBSD$ */ +/* $KAME: altq_red.c,v 1.18 2003/09/05 22:40:36 itojun 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. + */ + +#if defined(__FreeBSD__) || defined(__NetBSD__) +#include "opt_altq.h" +#if (__FreeBSD__ != 2) +#include "opt_inet.h" +#ifdef __FreeBSD__ +#include "opt_inet6.h" +#endif +#endif +#endif /* __FreeBSD__ || __NetBSD__ */ +#ifdef ALTQ_RED /* red is enabled by ALTQ_RED option in opt_altq.h */ + +#include <sys/param.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/socket.h> +#include <sys/systm.h> +#include <sys/errno.h> +#if 1 /* ALTQ3_COMPAT */ +#include <sys/sockio.h> +#include <sys/proc.h> +#include <sys/kernel.h> +#ifdef ALTQ_FLOWVALVE +#include <sys/queue.h> +#include <sys/time.h> +#endif +#endif /* ALTQ3_COMPAT */ + +#include <net/if.h> + +#include <netinet/in.h> +#include <netinet/in_systm.h> +#include <netinet/ip.h> +#ifdef INET6 +#include <netinet/ip6.h> +#endif + +#include <net/pfvar.h> +#include <altq/altq.h> +#include <altq/altq_red.h> +#ifdef ALTQ3_COMPAT +#include <altq/altq_conf.h> +#ifdef ALTQ_FLOWVALVE +#include <altq/altq_flowvalve.h> +#endif +#endif + +/* + * 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_STATS /* collect statistics */ + +/* + * 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". + */ + +#ifdef ALTQ3_COMPAT +#ifdef ALTQ_FLOWVALVE +/* + * flow-valve is an extention to protect red from unresponsive flows + * and to promote end-to-end congestion control. + * flow-valve observes the average drop rates of the flows that have + * experienced packet drops in the recent past. + * when the average drop rate exceeds the threshold, the flow is + * blocked by the flow-valve. the trapped flow should back off + * exponentially to escape from the flow-valve. + */ +#ifdef RED_RANDOM_DROP +#error "random-drop can't be used with flow-valve!" +#endif +#endif /* ALTQ_FLOWVALVE */ + +/* red_list keeps all red_queue_t's allocated. */ +static red_queue_t *red_list = NULL; + +#endif /* ALTQ3_COMPAT */ + +/* 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; + +#ifdef ALTQ3_COMPAT +/* internal function prototypes */ +static int red_enqueue(struct ifaltq *, struct mbuf *, struct altq_pktattr *); +static struct mbuf *red_dequeue(struct ifaltq *, int); +static int red_request(struct ifaltq *, int, void *); +static void red_purgeq(red_queue_t *); +static int red_detach(red_queue_t *); +#ifdef ALTQ_FLOWVALVE +static __inline struct fve *flowlist_lookup(struct flowvalve *, + struct altq_pktattr *, struct timeval *); +static __inline struct fve *flowlist_reclaim(struct flowvalve *, + struct altq_pktattr *); +static __inline void flowlist_move_to_head(struct flowvalve *, struct fve *); +static __inline int fv_p2f(struct flowvalve *, int); +#if 0 /* XXX: make the compiler happy (fv_alloc unused) */ +static struct flowvalve *fv_alloc(struct red *); +#endif +static void fv_destroy(struct flowvalve *); +static int fv_checkflow(struct flowvalve *, struct altq_pktattr *, + struct fve **); +static void fv_dropbyred(struct flowvalve *fv, struct altq_pktattr *, + struct fve *); +#endif +#endif /* ALTQ3_COMPAT */ + +/* + * red support routines + */ +red_t * +red_alloc(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; + + MALLOC(rp, red_t *, sizeof(red_t), M_DEVBUF, M_WAITOK); + if (rp == NULL) + return (NULL); + bzero(rp, sizeof(red_t)); + + 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_flags = flags; + + 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); + + microtime(&rp->red_last); + return (rp); +} + +void +red_destroy(red_t *rp) +{ +#ifdef ALTQ3_COMPAT +#ifdef ALTQ_FLOWVALVE + if (rp->red_flowvalve != NULL) + fv_destroy(rp->red_flowvalve); +#endif +#endif /* ALTQ3_COMPAT */ + wtab_destroy(rp->red_wtab); + FREE(rp, M_DEVBUF); +} + +void +red_getstats(red_t *rp, struct redstats *sp) +{ + sp->q_avg = rp->red_avg >> rp->red_wshift; + sp->xmit_cnt = rp->red_stats.xmit_cnt; + sp->drop_cnt = rp->red_stats.drop_cnt; + 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 altq_pktattr *pktattr) +{ + int avg, droptype; + int n; +#ifdef ALTQ3_COMPAT +#ifdef ALTQ_FLOWVALVE + struct fve *fve = NULL; + + if (rp->red_flowvalve != NULL && rp->red_flowvalve->fv_flows > 0) + if (fv_checkflow(rp->red_flowvalve, pktattr, &fve)) { + m_freem(m); + return (-1); + } +#endif +#endif /* ALTQ3_COMPAT */ + + 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; + microtime(&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 ((rp->red_flags & REDF_ECN) && + mark_ecn(m, pktattr, rp->red_flags)) { + /* successfully marked. do not drop. */ + rp->red_count = 0; +#ifdef RED_STATS + rp->red_stats.marked_packets++; +#endif + } else { + /* 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 */ +#ifdef RED_STATS + rp->red_stats.drop_unforced++; +#endif + } else { + /* forced drop, select a victim packet in the queue. */ +#ifdef RED_RANDOM_DROP + m = _getq_random(q); +#endif +#ifdef RED_STATS + rp->red_stats.drop_forced++; +#endif + } +#ifdef RED_STATS + PKTCNTR_ADD(&rp->red_stats.drop_cnt, m_pktlen(m)); +#endif + rp->red_count = 0; +#ifdef ALTQ3_COMPAT +#ifdef ALTQ_FLOWVALVE + if (rp->red_flowvalve != NULL) + fv_dropbyred(rp->red_flowvalve, pktattr, fve); +#endif +#endif /* ALTQ3_COMPAT */ + m_freem(m); + return (-1); + } + /* successfully queued */ +#ifdef RED_STATS + PKTCNTR_ADD(&rp->red_stats.xmit_cnt, m_pktlen(m)); +#endif + return (0); +} + +/* + * 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 ((arc4random() % d) < fp_len) { + /* drop or mark */ + return (1); + } + /* no drop/mark */ + return (0); +} + +/* + * try to mark CE bit to the packet. + * returns 1 if successfully marked, 0 otherwise. + */ +int +mark_ecn(struct mbuf *m, struct altq_pktattr *pktattr, int flags) +{ + struct mbuf *m0; + struct m_tag *t; + struct altq_tag *at; + void *hdr; + int af; + + t = m_tag_find(m, PACKET_TAG_PF_QID, NULL); + if (t != NULL) { + at = (struct altq_tag *)(t + 1); + if (at == NULL) + return (0); + af = at->af; + hdr = at->hdr; +#ifdef ALTQ3_COMPAT + } else if (pktattr != NULL) { + af = pktattr->pattr_af; + hdr = pktattr->pattr_hdr; +#endif /* ALTQ3_COMPAT */ + } else + return (0); + + if (af != AF_INET && af != AF_INET6) + return (0); + + /* verify that pattr_hdr is within the mbuf data */ + for (m0 = m; m0 != NULL; m0 = m0->m_next) + if (((caddr_t)hdr >= m0->m_data) && + ((caddr_t)hdr < m0->m_data + m0->m_len)) + break; + if (m0 == NULL) { + /* ick, tag info is stale */ + return (0); + } + + switch (af) { + case AF_INET: + if (flags & REDF_ECN4) { + struct ip *ip = hdr; + u_int8_t otos; + int sum; + + if (ip->ip_v != 4) + return (0); /* version mismatch! */ + + if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_NOTECT) + return (0); /* not-ECT */ + if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_CE) + return (1); /* already marked */ + + /* + * ecn-capable but not marked, + * mark CE and update checksum + */ + otos = ip->ip_tos; + ip->ip_tos |= IPTOS_ECN_CE; + /* + * update checksum (from RFC1624) + * HC' = ~(~HC + ~m + m') + */ + sum = ~ntohs(ip->ip_sum) & 0xffff; + sum += (~otos & 0xffff) + ip->ip_tos; + sum = (sum >> 16) + (sum & 0xffff); + sum += (sum >> 16); /* add carry */ + ip->ip_sum = htons(~sum & 0xffff); + return (1); + } + break; +#ifdef INET6 + case AF_INET6: + if (flags & REDF_ECN6) { + struct ip6_hdr *ip6 = hdr; + u_int32_t flowlabel; + + flowlabel = ntohl(ip6->ip6_flow); + if ((flowlabel >> 28) != 6) + return (0); /* version mismatch! */ + if ((flowlabel & (IPTOS_ECN_MASK << 20)) == + (IPTOS_ECN_NOTECT << 20)) + return (0); /* not-ECT */ + if ((flowlabel & (IPTOS_ECN_MASK << 20)) == + (IPTOS_ECN_CE << 20)) + return (1); /* already marked */ + /* + * ecn-capable but not marked, mark CE + */ + flowlabel |= (IPTOS_ECN_CE << 20); + ip6->ip6_flow = htonl(flowlabel); + return (1); + } + break; +#endif /* INET6 */ + } + + /* not marked */ + return (0); +} + +struct mbuf * +red_getq(rp, q) + red_t *rp; + class_queue_t *q; +{ + struct mbuf *m; + + if ((m = _getq(q)) == NULL) { + if (rp->red_idle == 0) { + rp->red_idle = 1; + microtime(&rp->red_last); + } + return NULL; + } + + rp->red_idle = 0; + return (m); +} + +/* + * 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); + } + + MALLOC(w, struct wtab *, sizeof(struct wtab), M_DEVBUF, M_WAITOK); + if (w == NULL) + panic("wtab_alloc: malloc failed!"); + bzero(w, sizeof(struct wtab)); + 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); +} + +int +wtab_destroy(struct wtab *w) +{ + struct wtab *prev; + + if (--w->w_refcount > 0) + return (0); + + 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); + return (0); +} + +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); +} + +#ifdef ALTQ3_COMPAT +/* + * red device interface + */ +altqdev_decl(red); + +int +redopen(dev, flag, fmt, p) + dev_t dev; + int flag, fmt; +#if (__FreeBSD_version > 500000) + struct thread *p; +#else + struct proc *p; +#endif +{ + /* everything will be done when the queueing scheme is attached. */ + return 0; +} + +int +redclose(dev, flag, fmt, p) + dev_t dev; + int flag, fmt; +#if (__FreeBSD_version > 500000) + struct thread *p; +#else + struct proc *p; +#endif +{ + red_queue_t *rqp; + int err, error = 0; + + while ((rqp = red_list) != NULL) { + /* destroy all */ + err = red_detach(rqp); + if (err != 0 && error == 0) + error = err; + } + + return error; +} + +int +redioctl(dev, cmd, addr, flag, p) + dev_t dev; + ioctlcmd_t cmd; + caddr_t addr; + int flag; +#if (__FreeBSD_version > 500000) + struct thread *p; +#else + struct proc *p; +#endif +{ + red_queue_t *rqp; + struct red_interface *ifacep; + struct ifnet *ifp; + int error = 0; + + /* check super-user privilege */ + switch (cmd) { + case RED_GETSTATS: + break; + default: +#if (__FreeBSD_version > 700000) + if ((error = priv_check(p, PRIV_ALTQ_MANAGE)) != 0) +#elsif (__FreeBSD_version > 400000) + if ((error = suser(p)) != 0) +#else + if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) +#endif + return (error); + break; + } + + switch (cmd) { + + case RED_ENABLE: + ifacep = (struct red_interface *)addr; + if ((rqp = altq_lookup(ifacep->red_ifname, ALTQT_RED)) == NULL) { + error = EBADF; + break; + } + error = altq_enable(rqp->rq_ifq); + break; + + case RED_DISABLE: + ifacep = (struct red_interface *)addr; + if ((rqp = altq_lookup(ifacep->red_ifname, ALTQT_RED)) == NULL) { + error = EBADF; + break; + } + error = altq_disable(rqp->rq_ifq); + break; + + case RED_IF_ATTACH: + ifp = ifunit(((struct red_interface *)addr)->red_ifname); + if (ifp == NULL) { + error = ENXIO; + break; + } + + /* allocate and initialize red_queue_t */ + MALLOC(rqp, red_queue_t *, sizeof(red_queue_t), M_DEVBUF, M_WAITOK); + if (rqp == NULL) { + error = ENOMEM; + break; + } + bzero(rqp, sizeof(red_queue_t)); + + MALLOC(rqp->rq_q, class_queue_t *, sizeof(class_queue_t), + M_DEVBUF, M_WAITOK); + if (rqp->rq_q == NULL) { + FREE(rqp, M_DEVBUF); + error = ENOMEM; + break; + } + bzero(rqp->rq_q, sizeof(class_queue_t)); + + rqp->rq_red = red_alloc(0, 0, 0, 0, 0, 0); + if (rqp->rq_red == NULL) { + FREE(rqp->rq_q, M_DEVBUF); + FREE(rqp, M_DEVBUF); + error = ENOMEM; + break; + } + + rqp->rq_ifq = &ifp->if_snd; + qtail(rqp->rq_q) = NULL; + qlen(rqp->rq_q) = 0; + qlimit(rqp->rq_q) = RED_LIMIT; + qtype(rqp->rq_q) = Q_RED; + + /* + * set RED to this ifnet structure. + */ + error = altq_attach(rqp->rq_ifq, ALTQT_RED, rqp, + red_enqueue, red_dequeue, red_request, + NULL, NULL); + if (error) { + red_destroy(rqp->rq_red); + FREE(rqp->rq_q, M_DEVBUF); + FREE(rqp, M_DEVBUF); + break; + } + + /* add this state to the red list */ + rqp->rq_next = red_list; + red_list = rqp; + break; + + case RED_IF_DETACH: + ifacep = (struct red_interface *)addr; + if ((rqp = altq_lookup(ifacep->red_ifname, ALTQT_RED)) == NULL) { + error = EBADF; + break; + } + error = red_detach(rqp); + break; + + case RED_GETSTATS: + do { + struct red_stats *q_stats; + red_t *rp; + + q_stats = (struct red_stats *)addr; + if ((rqp = altq_lookup(q_stats->iface.red_ifname, + ALTQT_RED)) == NULL) { + error = EBADF; + break; + } + + q_stats->q_len = qlen(rqp->rq_q); + q_stats->q_limit = qlimit(rqp->rq_q); + + rp = rqp->rq_red; + q_stats->q_avg = rp->red_avg >> rp->red_wshift; + q_stats->xmit_cnt = rp->red_stats.xmit_cnt; + q_stats->drop_cnt = rp->red_stats.drop_cnt; + q_stats->drop_forced = rp->red_stats.drop_forced; + q_stats->drop_unforced = rp->red_stats.drop_unforced; + q_stats->marked_packets = rp->red_stats.marked_packets; + + q_stats->weight = rp->red_weight; + q_stats->inv_pmax = rp->red_inv_pmax; + q_stats->th_min = rp->red_thmin; + q_stats->th_max = rp->red_thmax; + +#ifdef ALTQ_FLOWVALVE + if (rp->red_flowvalve != NULL) { + struct flowvalve *fv = rp->red_flowvalve; + q_stats->fv_flows = fv->fv_flows; + q_stats->fv_pass = fv->fv_stats.pass; + q_stats->fv_predrop = fv->fv_stats.predrop; + q_stats->fv_alloc = fv->fv_stats.alloc; + q_stats->fv_escape = fv->fv_stats.escape; + } else { +#endif /* ALTQ_FLOWVALVE */ + q_stats->fv_flows = 0; + q_stats->fv_pass = 0; + q_stats->fv_predrop = 0; + q_stats->fv_alloc = 0; + q_stats->fv_escape = 0; +#ifdef ALTQ_FLOWVALVE + } +#endif /* ALTQ_FLOWVALVE */ + } while (/*CONSTCOND*/ 0); + break; + + case RED_CONFIG: + do { + struct red_conf *fc; + red_t *new; + int s, limit; + + fc = (struct red_conf *)addr; + if ((rqp = altq_lookup(fc->iface.red_ifname, + ALTQT_RED)) == NULL) { + error = EBADF; + break; + } + new = red_alloc(fc->red_weight, + fc->red_inv_pmax, + fc->red_thmin, + fc->red_thmax, + fc->red_flags, + fc->red_pkttime); + if (new == NULL) { + error = ENOMEM; + break; + } + +#ifdef __NetBSD__ + s = splnet(); +#else + s = splimp(); +#endif + red_purgeq(rqp); + limit = fc->red_limit; + if (limit < fc->red_thmax) + limit = fc->red_thmax; + qlimit(rqp->rq_q) = limit; + fc->red_limit = limit; /* write back the new value */ + + red_destroy(rqp->rq_red); + rqp->rq_red = new; + + splx(s); + + /* write back new values */ + fc->red_limit = limit; + fc->red_inv_pmax = rqp->rq_red->red_inv_pmax; + fc->red_thmin = rqp->rq_red->red_thmin; + fc->red_thmax = rqp->rq_red->red_thmax; + + } while (/*CONSTCOND*/ 0); + break; + + case RED_SETDEFAULTS: + do { + struct redparams *rp; + + rp = (struct redparams *)addr; + + default_th_min = rp->th_min; + default_th_max = rp->th_max; + default_inv_pmax = rp->inv_pmax; + } while (/*CONSTCOND*/ 0); + break; + + default: + error = EINVAL; + break; + } + return error; +} + +static int +red_detach(rqp) + red_queue_t *rqp; +{ + red_queue_t *tmp; + int error = 0; + + if (ALTQ_IS_ENABLED(rqp->rq_ifq)) + altq_disable(rqp->rq_ifq); + + if ((error = altq_detach(rqp->rq_ifq))) + return (error); + + if (red_list == rqp) + red_list = rqp->rq_next; + else { + for (tmp = red_list; tmp != NULL; tmp = tmp->rq_next) + if (tmp->rq_next == rqp) { + tmp->rq_next = rqp->rq_next; + break; + } + if (tmp == NULL) + printf("red_detach: no state found in red_list!\n"); + } + + red_destroy(rqp->rq_red); + FREE(rqp->rq_q, M_DEVBUF); + FREE(rqp, M_DEVBUF); + return (error); +} + +/* + * enqueue routine: + * + * returns: 0 when successfully queued. + * ENOBUFS when drop occurs. + */ +static int +red_enqueue(ifq, m, pktattr) + struct ifaltq *ifq; + struct mbuf *m; + struct altq_pktattr *pktattr; +{ + red_queue_t *rqp = (red_queue_t *)ifq->altq_disc; + + IFQ_LOCK_ASSERT(ifq); + + if (red_addq(rqp->rq_red, rqp->rq_q, m, pktattr) < 0) + return ENOBUFS; + ifq->ifq_len++; + return 0; +} + +/* + * dequeue routine: + * must be called in splimp. + * + * returns: mbuf dequeued. + * NULL when no packet is available in the queue. + */ + +static struct mbuf * +red_dequeue(ifq, op) + struct ifaltq *ifq; + int op; +{ + red_queue_t *rqp = (red_queue_t *)ifq->altq_disc; + struct mbuf *m; + + IFQ_LOCK_ASSERT(ifq); + + if (op == ALTDQ_POLL) + return qhead(rqp->rq_q); + + /* op == ALTDQ_REMOVE */ + m = red_getq(rqp->rq_red, rqp->rq_q); + if (m != NULL) + ifq->ifq_len--; + return (m); +} + +static int +red_request(ifq, req, arg) + struct ifaltq *ifq; + int req; + void *arg; +{ + red_queue_t *rqp = (red_queue_t *)ifq->altq_disc; + + IFQ_LOCK_ASSERT(ifq); + + switch (req) { + case ALTRQ_PURGE: + red_purgeq(rqp); + break; + } + return (0); +} + +static void +red_purgeq(rqp) + red_queue_t *rqp; +{ + _flushq(rqp->rq_q); + if (ALTQ_IS_ENABLED(rqp->rq_ifq)) + rqp->rq_ifq->ifq_len = 0; +} + +#ifdef ALTQ_FLOWVALVE + +#define FV_PSHIFT 7 /* weight of average drop rate -- 1/128 */ +#define FV_PSCALE(x) ((x) << FV_PSHIFT) +#define FV_PUNSCALE(x) ((x) >> FV_PSHIFT) +#define FV_FSHIFT 5 /* weight of average fraction -- 1/32 */ +#define FV_FSCALE(x) ((x) << FV_FSHIFT) +#define FV_FUNSCALE(x) ((x) >> FV_FSHIFT) + +#define FV_TIMER (3 * hz) /* timer value for garbage collector */ +#define FV_FLOWLISTSIZE 64 /* how many flows in flowlist */ + +#define FV_N 10 /* update fve_f every FV_N packets */ + +#define FV_BACKOFFTHRESH 1 /* backoff threshold interval in second */ +#define FV_TTHRESH 3 /* time threshold to delete fve */ +#define FV_ALPHA 5 /* extra packet count */ + +#define FV_STATS + +#if (__FreeBSD_version > 300000) +#define FV_TIMESTAMP(tp) getmicrotime(tp) +#else +#define FV_TIMESTAMP(tp) { (*(tp)) = time; } +#endif + +/* + * Brtt table: 127 entry table to convert drop rate (p) to + * the corresponding bandwidth fraction (f) + * the following equation is implemented to use scaled values, + * fve_p and fve_f, in the fixed point format. + * + * Brtt(p) = 1 /(sqrt(4*p/3) + min(1,3*sqrt(p*6/8)) * p * (1+32 * p*p)) + * f = Brtt(p) / (max_th + alpha) + */ +#define BRTT_SIZE 128 +#define BRTT_SHIFT 12 +#define BRTT_MASK 0x0007f000 +#define BRTT_PMAX (1 << (FV_PSHIFT + FP_SHIFT)) + +const int brtt_tab[BRTT_SIZE] = { + 0, 1262010, 877019, 703694, 598706, 525854, 471107, 427728, + 392026, 361788, 335598, 312506, 291850, 273158, 256081, 240361, + 225800, 212247, 199585, 187788, 178388, 169544, 161207, 153333, + 145888, 138841, 132165, 125836, 119834, 114141, 108739, 103612, + 98747, 94129, 89746, 85585, 81637, 77889, 74333, 70957, + 67752, 64711, 61824, 59084, 56482, 54013, 51667, 49440, + 47325, 45315, 43406, 41591, 39866, 38227, 36667, 35184, + 33773, 32430, 31151, 29933, 28774, 27668, 26615, 25611, + 24653, 23740, 22868, 22035, 21240, 20481, 19755, 19062, + 18399, 17764, 17157, 16576, 16020, 15487, 14976, 14487, + 14017, 13567, 13136, 12721, 12323, 11941, 11574, 11222, + 10883, 10557, 10243, 9942, 9652, 9372, 9103, 8844, + 8594, 8354, 8122, 7898, 7682, 7474, 7273, 7079, + 6892, 6711, 6536, 6367, 6204, 6046, 5893, 5746, + 5603, 5464, 5330, 5201, 5075, 4954, 4836, 4722, + 4611, 4504, 4400, 4299, 4201, 4106, 4014, 3924 +}; + +static __inline struct fve * +flowlist_lookup(fv, pktattr, now) + struct flowvalve *fv; + struct altq_pktattr *pktattr; + struct timeval *now; +{ + struct fve *fve; + int flows; + struct ip *ip; +#ifdef INET6 + struct ip6_hdr *ip6; +#endif + struct timeval tthresh; + + if (pktattr == NULL) + return (NULL); + + tthresh.tv_sec = now->tv_sec - FV_TTHRESH; + flows = 0; + /* + * search the flow list + */ + switch (pktattr->pattr_af) { + case AF_INET: + ip = (struct ip *)pktattr->pattr_hdr; + TAILQ_FOREACH(fve, &fv->fv_flowlist, fve_lru){ + if (fve->fve_lastdrop.tv_sec == 0) + break; + if (fve->fve_lastdrop.tv_sec < tthresh.tv_sec) { + fve->fve_lastdrop.tv_sec = 0; + break; + } + if (fve->fve_flow.flow_af == AF_INET && + fve->fve_flow.flow_ip.ip_src.s_addr == + ip->ip_src.s_addr && + fve->fve_flow.flow_ip.ip_dst.s_addr == + ip->ip_dst.s_addr) + return (fve); + flows++; + } + break; +#ifdef INET6 + case AF_INET6: + ip6 = (struct ip6_hdr *)pktattr->pattr_hdr; + TAILQ_FOREACH(fve, &fv->fv_flowlist, fve_lru){ + if (fve->fve_lastdrop.tv_sec == 0) + break; + if (fve->fve_lastdrop.tv_sec < tthresh.tv_sec) { + fve->fve_lastdrop.tv_sec = 0; + break; + } + if (fve->fve_flow.flow_af == AF_INET6 && + IN6_ARE_ADDR_EQUAL(&fve->fve_flow.flow_ip6.ip6_src, + &ip6->ip6_src) && + IN6_ARE_ADDR_EQUAL(&fve->fve_flow.flow_ip6.ip6_dst, + &ip6->ip6_dst)) + return (fve); + flows++; + } + break; +#endif /* INET6 */ + + default: + /* unknown protocol. no drop. */ + return (NULL); + } + fv->fv_flows = flows; /* save the number of active fve's */ + return (NULL); +} + +static __inline struct fve * +flowlist_reclaim(fv, pktattr) + struct flowvalve *fv; + struct altq_pktattr *pktattr; +{ + struct fve *fve; + struct ip *ip; +#ifdef INET6 + struct ip6_hdr *ip6; +#endif + + /* + * get an entry from the tail of the LRU list. + */ + fve = TAILQ_LAST(&fv->fv_flowlist, fv_flowhead); + + switch (pktattr->pattr_af) { + case AF_INET: + ip = (struct ip *)pktattr->pattr_hdr; + fve->fve_flow.flow_af = AF_INET; + fve->fve_flow.flow_ip.ip_src = ip->ip_src; + fve->fve_flow.flow_ip.ip_dst = ip->ip_dst; + break; +#ifdef INET6 + case AF_INET6: + ip6 = (struct ip6_hdr *)pktattr->pattr_hdr; + fve->fve_flow.flow_af = AF_INET6; + fve->fve_flow.flow_ip6.ip6_src = ip6->ip6_src; + fve->fve_flow.flow_ip6.ip6_dst = ip6->ip6_dst; + break; +#endif + } + + fve->fve_state = Green; + fve->fve_p = 0.0; + fve->fve_f = 0.0; + fve->fve_ifseq = fv->fv_ifseq - 1; + fve->fve_count = 0; + + fv->fv_flows++; +#ifdef FV_STATS + fv->fv_stats.alloc++; +#endif + return (fve); +} + +static __inline void +flowlist_move_to_head(fv, fve) + struct flowvalve *fv; + struct fve *fve; +{ + if (TAILQ_FIRST(&fv->fv_flowlist) != fve) { + TAILQ_REMOVE(&fv->fv_flowlist, fve, fve_lru); + TAILQ_INSERT_HEAD(&fv->fv_flowlist, fve, fve_lru); + } +} + +#if 0 /* XXX: make the compiler happy (fv_alloc unused) */ +/* + * allocate flowvalve structure + */ +static struct flowvalve * +fv_alloc(rp) + struct red *rp; +{ + struct flowvalve *fv; + struct fve *fve; + int i, num; + + num = FV_FLOWLISTSIZE; + MALLOC(fv, struct flowvalve *, sizeof(struct flowvalve), + M_DEVBUF, M_WAITOK); + if (fv == NULL) + return (NULL); + bzero(fv, sizeof(struct flowvalve)); + + MALLOC(fv->fv_fves, struct fve *, sizeof(struct fve) * num, + M_DEVBUF, M_WAITOK); + if (fv->fv_fves == NULL) { + FREE(fv, M_DEVBUF); + return (NULL); + } + bzero(fv->fv_fves, sizeof(struct fve) * num); + + fv->fv_flows = 0; + TAILQ_INIT(&fv->fv_flowlist); + for (i = 0; i < num; i++) { + fve = &fv->fv_fves[i]; + fve->fve_lastdrop.tv_sec = 0; + TAILQ_INSERT_TAIL(&fv->fv_flowlist, fve, fve_lru); + } + + /* initialize drop rate threshold in scaled fixed-point */ + fv->fv_pthresh = (FV_PSCALE(1) << FP_SHIFT) / rp->red_inv_pmax; + + /* initialize drop rate to fraction table */ + MALLOC(fv->fv_p2ftab, int *, sizeof(int) * BRTT_SIZE, + M_DEVBUF, M_WAITOK); + if (fv->fv_p2ftab == NULL) { + FREE(fv->fv_fves, M_DEVBUF); + FREE(fv, M_DEVBUF); + return (NULL); + } + /* + * create the p2f table. + * (shift is used to keep the precision) + */ + for (i = 1; i < BRTT_SIZE; i++) { + int f; + + f = brtt_tab[i] << 8; + fv->fv_p2ftab[i] = (f / (rp->red_thmax + FV_ALPHA)) >> 8; + } + + return (fv); +} +#endif + +static void fv_destroy(fv) + struct flowvalve *fv; +{ + FREE(fv->fv_p2ftab, M_DEVBUF); + FREE(fv->fv_fves, M_DEVBUF); + FREE(fv, M_DEVBUF); +} + +static __inline int +fv_p2f(fv, p) + struct flowvalve *fv; + int p; +{ + int val, f; + + if (p >= BRTT_PMAX) + f = fv->fv_p2ftab[BRTT_SIZE-1]; + else if ((val = (p & BRTT_MASK))) + f = fv->fv_p2ftab[(val >> BRTT_SHIFT)]; + else + f = fv->fv_p2ftab[1]; + return (f); +} + +/* + * check if an arriving packet should be pre-dropped. + * called from red_addq() when a packet arrives. + * returns 1 when the packet should be pre-dropped. + * should be called in splimp. + */ +static int +fv_checkflow(fv, pktattr, fcache) + struct flowvalve *fv; + struct altq_pktattr *pktattr; + struct fve **fcache; +{ + struct fve *fve; + struct timeval now; + + fv->fv_ifseq++; + FV_TIMESTAMP(&now); + + if ((fve = flowlist_lookup(fv, pktattr, &now)) == NULL) + /* no matching entry in the flowlist */ + return (0); + + *fcache = fve; + + /* update fraction f for every FV_N packets */ + if (++fve->fve_count == FV_N) { + /* + * f = Wf * N / (fv_ifseq - fve_ifseq) + (1 - Wf) * f + */ + fve->fve_f = + (FV_N << FP_SHIFT) / (fv->fv_ifseq - fve->fve_ifseq) + + fve->fve_f - FV_FUNSCALE(fve->fve_f); + fve->fve_ifseq = fv->fv_ifseq; + fve->fve_count = 0; + } + + /* + * overpumping test + */ + if (fve->fve_state == Green && fve->fve_p > fv->fv_pthresh) { + int fthresh; + + /* calculate a threshold */ + fthresh = fv_p2f(fv, fve->fve_p); + if (fve->fve_f > fthresh) + fve->fve_state = Red; + } + + if (fve->fve_state == Red) { + /* + * backoff test + */ + if (now.tv_sec - fve->fve_lastdrop.tv_sec > FV_BACKOFFTHRESH) { + /* no drop for at least FV_BACKOFFTHRESH sec */ + fve->fve_p = 0; + fve->fve_state = Green; +#ifdef FV_STATS + fv->fv_stats.escape++; +#endif + } else { + /* block this flow */ + flowlist_move_to_head(fv, fve); + fve->fve_lastdrop = now; +#ifdef FV_STATS + fv->fv_stats.predrop++; +#endif + return (1); + } + } + + /* + * p = (1 - Wp) * p + */ + fve->fve_p -= FV_PUNSCALE(fve->fve_p); + if (fve->fve_p < 0) + fve->fve_p = 0; +#ifdef FV_STATS + fv->fv_stats.pass++; +#endif + return (0); +} + +/* + * called from red_addq when a packet is dropped by red. + * should be called in splimp. + */ +static void fv_dropbyred(fv, pktattr, fcache) + struct flowvalve *fv; + struct altq_pktattr *pktattr; + struct fve *fcache; +{ + struct fve *fve; + struct timeval now; + + if (pktattr == NULL) + return; + FV_TIMESTAMP(&now); + + if (fcache != NULL) + /* the fve of this packet is already cached */ + fve = fcache; + else if ((fve = flowlist_lookup(fv, pktattr, &now)) == NULL) + fve = flowlist_reclaim(fv, pktattr); + + flowlist_move_to_head(fv, fve); + + /* + * update p: the following line cancels the update + * in fv_checkflow() and calculate + * p = Wp + (1 - Wp) * p + */ + fve->fve_p = (1 << FP_SHIFT) + fve->fve_p; + + fve->fve_lastdrop = now; +} + +#endif /* ALTQ_FLOWVALVE */ + +#ifdef KLD_MODULE + +static struct altqsw red_sw = + {"red", redopen, redclose, redioctl}; + +ALTQ_MODULE(altq_red, ALTQT_RED, &red_sw); +MODULE_VERSION(altq_red, 1); + +#endif /* KLD_MODULE */ +#endif /* ALTQ3_COMPAT */ + +#endif /* ALTQ_RED */ |