From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- net/sched/sch_red.c | 391 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 391 insertions(+) create mode 100644 net/sched/sch_red.c (limited to 'net/sched/sch_red.c') diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c new file mode 100644 index 000000000..6c0534cc7 --- /dev/null +++ b/net/sched/sch_red.c @@ -0,0 +1,391 @@ +/* + * net/sched/sch_red.c Random Early Detection queue. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Authors: Alexey Kuznetsov, + * + * Changes: + * J Hadi Salim 980914: computation fixes + * Alexey Makarenko 990814: qave on idle link was calculated incorrectly. + * J Hadi Salim 980816: ECN support + */ + +#include +#include +#include +#include +#include +#include +#include + + +/* Parameters, settable by user: + ----------------------------- + + limit - bytes (must be > qth_max + burst) + + Hard limit on queue length, should be chosen >qth_max + to allow packet bursts. This parameter does not + affect the algorithms behaviour and can be chosen + arbitrarily high (well, less than ram size) + Really, this limit will never be reached + if RED works correctly. + */ + +struct red_sched_data { + u32 limit; /* HARD maximal queue length */ + unsigned char flags; + struct timer_list adapt_timer; + struct red_parms parms; + struct red_vars vars; + struct red_stats stats; + struct Qdisc *qdisc; +}; + +static inline int red_use_ecn(struct red_sched_data *q) +{ + return q->flags & TC_RED_ECN; +} + +static inline int red_use_harddrop(struct red_sched_data *q) +{ + return q->flags & TC_RED_HARDDROP; +} + +static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch) +{ + struct red_sched_data *q = qdisc_priv(sch); + struct Qdisc *child = q->qdisc; + int ret; + + q->vars.qavg = red_calc_qavg(&q->parms, + &q->vars, + child->qstats.backlog); + + if (red_is_idling(&q->vars)) + red_end_of_idle_period(&q->vars); + + switch (red_action(&q->parms, &q->vars, q->vars.qavg)) { + case RED_DONT_MARK: + break; + + case RED_PROB_MARK: + qdisc_qstats_overlimit(sch); + if (!red_use_ecn(q) || !INET_ECN_set_ce(skb)) { + q->stats.prob_drop++; + goto congestion_drop; + } + + q->stats.prob_mark++; + break; + + case RED_HARD_MARK: + qdisc_qstats_overlimit(sch); + if (red_use_harddrop(q) || !red_use_ecn(q) || + !INET_ECN_set_ce(skb)) { + q->stats.forced_drop++; + goto congestion_drop; + } + + q->stats.forced_mark++; + break; + } + + ret = qdisc_enqueue(skb, child); + if (likely(ret == NET_XMIT_SUCCESS)) { + sch->q.qlen++; + } else if (net_xmit_drop_count(ret)) { + q->stats.pdrop++; + qdisc_qstats_drop(sch); + } + return ret; + +congestion_drop: + qdisc_drop(skb, sch); + return NET_XMIT_CN; +} + +static struct sk_buff *red_dequeue(struct Qdisc *sch) +{ + struct sk_buff *skb; + struct red_sched_data *q = qdisc_priv(sch); + struct Qdisc *child = q->qdisc; + + skb = child->dequeue(child); + if (skb) { + qdisc_bstats_update(sch, skb); + sch->q.qlen--; + } else { + if (!red_is_idling(&q->vars)) + red_start_of_idle_period(&q->vars); + } + return skb; +} + +static struct sk_buff *red_peek(struct Qdisc *sch) +{ + struct red_sched_data *q = qdisc_priv(sch); + struct Qdisc *child = q->qdisc; + + return child->ops->peek(child); +} + +static unsigned int red_drop(struct Qdisc *sch) +{ + struct red_sched_data *q = qdisc_priv(sch); + struct Qdisc *child = q->qdisc; + unsigned int len; + + if (child->ops->drop && (len = child->ops->drop(child)) > 0) { + q->stats.other++; + qdisc_qstats_drop(sch); + sch->q.qlen--; + return len; + } + + if (!red_is_idling(&q->vars)) + red_start_of_idle_period(&q->vars); + + return 0; +} + +static void red_reset(struct Qdisc *sch) +{ + struct red_sched_data *q = qdisc_priv(sch); + + qdisc_reset(q->qdisc); + sch->q.qlen = 0; + red_restart(&q->vars); +} + +static void red_destroy(struct Qdisc *sch) +{ + struct red_sched_data *q = qdisc_priv(sch); + + del_timer_sync(&q->adapt_timer); + qdisc_destroy(q->qdisc); +} + +static const struct nla_policy red_policy[TCA_RED_MAX + 1] = { + [TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) }, + [TCA_RED_STAB] = { .len = RED_STAB_SIZE }, + [TCA_RED_MAX_P] = { .type = NLA_U32 }, +}; + +static int red_change(struct Qdisc *sch, struct nlattr *opt) +{ + struct red_sched_data *q = qdisc_priv(sch); + struct nlattr *tb[TCA_RED_MAX + 1]; + struct tc_red_qopt *ctl; + struct Qdisc *child = NULL; + int err; + u32 max_P; + + if (opt == NULL) + return -EINVAL; + + err = nla_parse_nested(tb, TCA_RED_MAX, opt, red_policy); + if (err < 0) + return err; + + if (tb[TCA_RED_PARMS] == NULL || + tb[TCA_RED_STAB] == NULL) + return -EINVAL; + + max_P = tb[TCA_RED_MAX_P] ? nla_get_u32(tb[TCA_RED_MAX_P]) : 0; + + ctl = nla_data(tb[TCA_RED_PARMS]); + + if (ctl->limit > 0) { + child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit); + if (IS_ERR(child)) + return PTR_ERR(child); + } + + sch_tree_lock(sch); + q->flags = ctl->flags; + q->limit = ctl->limit; + if (child) { + qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen); + qdisc_destroy(q->qdisc); + q->qdisc = child; + } + + red_set_parms(&q->parms, + ctl->qth_min, ctl->qth_max, ctl->Wlog, + ctl->Plog, ctl->Scell_log, + nla_data(tb[TCA_RED_STAB]), + max_P); + red_set_vars(&q->vars); + + del_timer(&q->adapt_timer); + if (ctl->flags & TC_RED_ADAPTATIVE) + mod_timer(&q->adapt_timer, jiffies + HZ/2); + + if (!q->qdisc->q.qlen) + red_start_of_idle_period(&q->vars); + + sch_tree_unlock(sch); + return 0; +} + +static inline void red_adaptative_timer(unsigned long arg) +{ + struct Qdisc *sch = (struct Qdisc *)arg; + struct red_sched_data *q = qdisc_priv(sch); + spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch)); + + spin_lock(root_lock); + red_adaptative_algo(&q->parms, &q->vars); + mod_timer(&q->adapt_timer, jiffies + HZ/2); + spin_unlock(root_lock); +} + +static int red_init(struct Qdisc *sch, struct nlattr *opt) +{ + struct red_sched_data *q = qdisc_priv(sch); + + q->qdisc = &noop_qdisc; + setup_timer(&q->adapt_timer, red_adaptative_timer, (unsigned long)sch); + return red_change(sch, opt); +} + +static int red_dump(struct Qdisc *sch, struct sk_buff *skb) +{ + struct red_sched_data *q = qdisc_priv(sch); + struct nlattr *opts = NULL; + struct tc_red_qopt opt = { + .limit = q->limit, + .flags = q->flags, + .qth_min = q->parms.qth_min >> q->parms.Wlog, + .qth_max = q->parms.qth_max >> q->parms.Wlog, + .Wlog = q->parms.Wlog, + .Plog = q->parms.Plog, + .Scell_log = q->parms.Scell_log, + }; + + sch->qstats.backlog = q->qdisc->qstats.backlog; + opts = nla_nest_start(skb, TCA_OPTIONS); + if (opts == NULL) + goto nla_put_failure; + if (nla_put(skb, TCA_RED_PARMS, sizeof(opt), &opt) || + nla_put_u32(skb, TCA_RED_MAX_P, q->parms.max_P)) + goto nla_put_failure; + return nla_nest_end(skb, opts); + +nla_put_failure: + nla_nest_cancel(skb, opts); + return -EMSGSIZE; +} + +static int red_dump_stats(struct Qdisc *sch, struct gnet_dump *d) +{ + struct red_sched_data *q = qdisc_priv(sch); + struct tc_red_xstats st = { + .early = q->stats.prob_drop + q->stats.forced_drop, + .pdrop = q->stats.pdrop, + .other = q->stats.other, + .marked = q->stats.prob_mark + q->stats.forced_mark, + }; + + return gnet_stats_copy_app(d, &st, sizeof(st)); +} + +static int red_dump_class(struct Qdisc *sch, unsigned long cl, + struct sk_buff *skb, struct tcmsg *tcm) +{ + struct red_sched_data *q = qdisc_priv(sch); + + tcm->tcm_handle |= TC_H_MIN(1); + tcm->tcm_info = q->qdisc->handle; + return 0; +} + +static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, + struct Qdisc **old) +{ + struct red_sched_data *q = qdisc_priv(sch); + + if (new == NULL) + new = &noop_qdisc; + + sch_tree_lock(sch); + *old = q->qdisc; + q->qdisc = new; + qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); + qdisc_reset(*old); + sch_tree_unlock(sch); + return 0; +} + +static struct Qdisc *red_leaf(struct Qdisc *sch, unsigned long arg) +{ + struct red_sched_data *q = qdisc_priv(sch); + return q->qdisc; +} + +static unsigned long red_get(struct Qdisc *sch, u32 classid) +{ + return 1; +} + +static void red_put(struct Qdisc *sch, unsigned long arg) +{ +} + +static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker) +{ + if (!walker->stop) { + if (walker->count >= walker->skip) + if (walker->fn(sch, 1, walker) < 0) { + walker->stop = 1; + return; + } + walker->count++; + } +} + +static const struct Qdisc_class_ops red_class_ops = { + .graft = red_graft, + .leaf = red_leaf, + .get = red_get, + .put = red_put, + .walk = red_walk, + .dump = red_dump_class, +}; + +static struct Qdisc_ops red_qdisc_ops __read_mostly = { + .id = "red", + .priv_size = sizeof(struct red_sched_data), + .cl_ops = &red_class_ops, + .enqueue = red_enqueue, + .dequeue = red_dequeue, + .peek = red_peek, + .drop = red_drop, + .init = red_init, + .reset = red_reset, + .destroy = red_destroy, + .change = red_change, + .dump = red_dump, + .dump_stats = red_dump_stats, + .owner = THIS_MODULE, +}; + +static int __init red_module_init(void) +{ + return register_qdisc(&red_qdisc_ops); +} + +static void __exit red_module_exit(void) +{ + unregister_qdisc(&red_qdisc_ops); +} + +module_init(red_module_init) +module_exit(red_module_exit) + +MODULE_LICENSE("GPL"); -- cgit v1.2.3-54-g00ecf