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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /net/sched/sch_red.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/sched/sch_red.c')
-rw-r--r--net/sched/sch_red.c565
1 files changed, 565 insertions, 0 deletions
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
new file mode 100644
index 000000000..16277b6a0
--- /dev/null
+++ b/net/sched/sch_red.c
@@ -0,0 +1,565 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * net/sched/sch_red.c Random Early Detection queue.
+ *
+ * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ * Changes:
+ * J Hadi Salim 980914: computation fixes
+ * Alexey Makarenko <makar@phoenix.kharkov.ua> 990814: qave on idle link was calculated incorrectly.
+ * J Hadi Salim 980816: ECN support
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+#include <net/inet_ecn.h>
+#include <net/red.h>
+
+
+/* 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;
+ /* Non-flags in tc_red_qopt.flags. */
+ unsigned char userbits;
+
+ struct timer_list adapt_timer;
+ struct Qdisc *sch;
+ struct red_parms parms;
+ struct red_vars vars;
+ struct red_stats stats;
+ struct Qdisc *qdisc;
+ struct tcf_qevent qe_early_drop;
+ struct tcf_qevent qe_mark;
+};
+
+#define TC_RED_SUPPORTED_FLAGS (TC_RED_HISTORIC_FLAGS | TC_RED_NODROP)
+
+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_use_nodrop(struct red_sched_data *q)
+{
+ return q->flags & TC_RED_NODROP;
+}
+
+static int red_enqueue(struct sk_buff *skb, struct Qdisc *sch,
+ struct sk_buff **to_free)
+{
+ struct red_sched_data *q = qdisc_priv(sch);
+ struct Qdisc *child = q->qdisc;
+ unsigned int len;
+ 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)) {
+ q->stats.prob_drop++;
+ goto congestion_drop;
+ }
+
+ if (INET_ECN_set_ce(skb)) {
+ q->stats.prob_mark++;
+ skb = tcf_qevent_handle(&q->qe_mark, sch, skb, to_free, &ret);
+ if (!skb)
+ return NET_XMIT_CN | ret;
+ } else if (!red_use_nodrop(q)) {
+ q->stats.prob_drop++;
+ goto congestion_drop;
+ }
+
+ /* Non-ECT packet in ECN nodrop mode: queue it. */
+ break;
+
+ case RED_HARD_MARK:
+ qdisc_qstats_overlimit(sch);
+ if (red_use_harddrop(q) || !red_use_ecn(q)) {
+ q->stats.forced_drop++;
+ goto congestion_drop;
+ }
+
+ if (INET_ECN_set_ce(skb)) {
+ q->stats.forced_mark++;
+ skb = tcf_qevent_handle(&q->qe_mark, sch, skb, to_free, &ret);
+ if (!skb)
+ return NET_XMIT_CN | ret;
+ } else if (!red_use_nodrop(q)) {
+ q->stats.forced_drop++;
+ goto congestion_drop;
+ }
+
+ /* Non-ECT packet in ECN nodrop mode: queue it. */
+ break;
+ }
+
+ len = qdisc_pkt_len(skb);
+ ret = qdisc_enqueue(skb, child, to_free);
+ if (likely(ret == NET_XMIT_SUCCESS)) {
+ sch->qstats.backlog += len;
+ sch->q.qlen++;
+ } else if (net_xmit_drop_count(ret)) {
+ q->stats.pdrop++;
+ qdisc_qstats_drop(sch);
+ }
+ return ret;
+
+congestion_drop:
+ skb = tcf_qevent_handle(&q->qe_early_drop, sch, skb, to_free, &ret);
+ if (!skb)
+ return NET_XMIT_CN | ret;
+
+ qdisc_drop(skb, sch, to_free);
+ 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);
+ qdisc_qstats_backlog_dec(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 void red_reset(struct Qdisc *sch)
+{
+ struct red_sched_data *q = qdisc_priv(sch);
+
+ qdisc_reset(q->qdisc);
+ red_restart(&q->vars);
+}
+
+static int red_offload(struct Qdisc *sch, bool enable)
+{
+ struct red_sched_data *q = qdisc_priv(sch);
+ struct net_device *dev = qdisc_dev(sch);
+ struct tc_red_qopt_offload opt = {
+ .handle = sch->handle,
+ .parent = sch->parent,
+ };
+
+ if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc)
+ return -EOPNOTSUPP;
+
+ if (enable) {
+ opt.command = TC_RED_REPLACE;
+ opt.set.min = q->parms.qth_min >> q->parms.Wlog;
+ opt.set.max = q->parms.qth_max >> q->parms.Wlog;
+ opt.set.probability = q->parms.max_P;
+ opt.set.limit = q->limit;
+ opt.set.is_ecn = red_use_ecn(q);
+ opt.set.is_harddrop = red_use_harddrop(q);
+ opt.set.is_nodrop = red_use_nodrop(q);
+ opt.set.qstats = &sch->qstats;
+ } else {
+ opt.command = TC_RED_DESTROY;
+ }
+
+ return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED, &opt);
+}
+
+static void red_destroy(struct Qdisc *sch)
+{
+ struct red_sched_data *q = qdisc_priv(sch);
+
+ tcf_qevent_destroy(&q->qe_mark, sch);
+ tcf_qevent_destroy(&q->qe_early_drop, sch);
+ del_timer_sync(&q->adapt_timer);
+ red_offload(sch, false);
+ qdisc_put(q->qdisc);
+}
+
+static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
+ [TCA_RED_UNSPEC] = { .strict_start_type = TCA_RED_FLAGS },
+ [TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) },
+ [TCA_RED_STAB] = { .len = RED_STAB_SIZE },
+ [TCA_RED_MAX_P] = { .type = NLA_U32 },
+ [TCA_RED_FLAGS] = NLA_POLICY_BITFIELD32(TC_RED_SUPPORTED_FLAGS),
+ [TCA_RED_EARLY_DROP_BLOCK] = { .type = NLA_U32 },
+ [TCA_RED_MARK_BLOCK] = { .type = NLA_U32 },
+};
+
+static int __red_change(struct Qdisc *sch, struct nlattr **tb,
+ struct netlink_ext_ack *extack)
+{
+ struct Qdisc *old_child = NULL, *child = NULL;
+ struct red_sched_data *q = qdisc_priv(sch);
+ struct nla_bitfield32 flags_bf;
+ struct tc_red_qopt *ctl;
+ unsigned char userbits;
+ unsigned char flags;
+ int err;
+ u32 max_P;
+ u8 *stab;
+
+ 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]);
+ stab = nla_data(tb[TCA_RED_STAB]);
+ if (!red_check_params(ctl->qth_min, ctl->qth_max, ctl->Wlog,
+ ctl->Scell_log, stab))
+ return -EINVAL;
+
+ err = red_get_flags(ctl->flags, TC_RED_HISTORIC_FLAGS,
+ tb[TCA_RED_FLAGS], TC_RED_SUPPORTED_FLAGS,
+ &flags_bf, &userbits, extack);
+ if (err)
+ return err;
+
+ if (ctl->limit > 0) {
+ child = fifo_create_dflt(sch, &bfifo_qdisc_ops, ctl->limit,
+ extack);
+ if (IS_ERR(child))
+ return PTR_ERR(child);
+
+ /* child is fifo, no need to check for noop_qdisc */
+ qdisc_hash_add(child, true);
+ }
+
+ sch_tree_lock(sch);
+
+ flags = (q->flags & ~flags_bf.selector) | flags_bf.value;
+ err = red_validate_flags(flags, extack);
+ if (err)
+ goto unlock_out;
+
+ q->flags = flags;
+ q->userbits = userbits;
+ q->limit = ctl->limit;
+ if (child) {
+ qdisc_tree_flush_backlog(q->qdisc);
+ old_child = q->qdisc;
+ q->qdisc = child;
+ }
+
+ red_set_parms(&q->parms,
+ ctl->qth_min, ctl->qth_max, ctl->Wlog,
+ ctl->Plog, ctl->Scell_log,
+ 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);
+
+ red_offload(sch, true);
+
+ if (old_child)
+ qdisc_put(old_child);
+ return 0;
+
+unlock_out:
+ sch_tree_unlock(sch);
+ if (child)
+ qdisc_put(child);
+ return err;
+}
+
+static inline void red_adaptative_timer(struct timer_list *t)
+{
+ struct red_sched_data *q = from_timer(q, t, adapt_timer);
+ struct Qdisc *sch = q->sch;
+ spinlock_t *root_lock;
+
+ rcu_read_lock();
+ 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);
+ rcu_read_unlock();
+}
+
+static int red_init(struct Qdisc *sch, struct nlattr *opt,
+ struct netlink_ext_ack *extack)
+{
+ struct red_sched_data *q = qdisc_priv(sch);
+ struct nlattr *tb[TCA_RED_MAX + 1];
+ int err;
+
+ q->qdisc = &noop_qdisc;
+ q->sch = sch;
+ timer_setup(&q->adapt_timer, red_adaptative_timer, 0);
+
+ if (!opt)
+ return -EINVAL;
+
+ err = nla_parse_nested_deprecated(tb, TCA_RED_MAX, opt, red_policy,
+ extack);
+ if (err < 0)
+ return err;
+
+ err = __red_change(sch, tb, extack);
+ if (err)
+ return err;
+
+ err = tcf_qevent_init(&q->qe_early_drop, sch,
+ FLOW_BLOCK_BINDER_TYPE_RED_EARLY_DROP,
+ tb[TCA_RED_EARLY_DROP_BLOCK], extack);
+ if (err)
+ return err;
+
+ return tcf_qevent_init(&q->qe_mark, sch,
+ FLOW_BLOCK_BINDER_TYPE_RED_MARK,
+ tb[TCA_RED_MARK_BLOCK], extack);
+}
+
+static int red_change(struct Qdisc *sch, struct nlattr *opt,
+ struct netlink_ext_ack *extack)
+{
+ struct red_sched_data *q = qdisc_priv(sch);
+ struct nlattr *tb[TCA_RED_MAX + 1];
+ int err;
+
+ err = nla_parse_nested_deprecated(tb, TCA_RED_MAX, opt, red_policy,
+ extack);
+ if (err < 0)
+ return err;
+
+ err = tcf_qevent_validate_change(&q->qe_early_drop,
+ tb[TCA_RED_EARLY_DROP_BLOCK], extack);
+ if (err)
+ return err;
+
+ err = tcf_qevent_validate_change(&q->qe_mark,
+ tb[TCA_RED_MARK_BLOCK], extack);
+ if (err)
+ return err;
+
+ return __red_change(sch, tb, extack);
+}
+
+static int red_dump_offload_stats(struct Qdisc *sch)
+{
+ struct tc_red_qopt_offload hw_stats = {
+ .command = TC_RED_STATS,
+ .handle = sch->handle,
+ .parent = sch->parent,
+ {
+ .stats.bstats = &sch->bstats,
+ .stats.qstats = &sch->qstats,
+ },
+ };
+
+ return qdisc_offload_dump_helper(sch, TC_SETUP_QDISC_RED, &hw_stats);
+}
+
+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 & TC_RED_HISTORIC_FLAGS) |
+ q->userbits,
+ .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,
+ };
+ int err;
+
+ err = red_dump_offload_stats(sch);
+ if (err)
+ goto nla_put_failure;
+
+ opts = nla_nest_start_noflag(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) ||
+ nla_put_bitfield32(skb, TCA_RED_FLAGS,
+ q->flags, TC_RED_SUPPORTED_FLAGS) ||
+ tcf_qevent_dump(skb, TCA_RED_MARK_BLOCK, &q->qe_mark) ||
+ tcf_qevent_dump(skb, TCA_RED_EARLY_DROP_BLOCK, &q->qe_early_drop))
+ 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 net_device *dev = qdisc_dev(sch);
+ struct tc_red_xstats st = {0};
+
+ if (sch->flags & TCQ_F_OFFLOADED) {
+ struct tc_red_qopt_offload hw_stats_request = {
+ .command = TC_RED_XSTATS,
+ .handle = sch->handle,
+ .parent = sch->parent,
+ {
+ .xstats = &q->stats,
+ },
+ };
+ dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_RED,
+ &hw_stats_request);
+ }
+ st.early = q->stats.prob_drop + q->stats.forced_drop;
+ st.pdrop = q->stats.pdrop;
+ st.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 void red_graft_offload(struct Qdisc *sch,
+ struct Qdisc *new, struct Qdisc *old,
+ struct netlink_ext_ack *extack)
+{
+ struct tc_red_qopt_offload graft_offload = {
+ .handle = sch->handle,
+ .parent = sch->parent,
+ .child_handle = new->handle,
+ .command = TC_RED_GRAFT,
+ };
+
+ qdisc_offload_graft_helper(qdisc_dev(sch), sch, new, old,
+ TC_SETUP_QDISC_RED, &graft_offload, extack);
+}
+
+static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
+ struct Qdisc **old, struct netlink_ext_ack *extack)
+{
+ struct red_sched_data *q = qdisc_priv(sch);
+
+ if (new == NULL)
+ new = &noop_qdisc;
+
+ *old = qdisc_replace(sch, new, &q->qdisc);
+
+ red_graft_offload(sch, new, *old, extack);
+ 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_find(struct Qdisc *sch, u32 classid)
+{
+ return 1;
+}
+
+static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker)
+{
+ if (!walker->stop) {
+ tc_qdisc_stats_dump(sch, 1, walker);
+ }
+}
+
+static const struct Qdisc_class_ops red_class_ops = {
+ .graft = red_graft,
+ .leaf = red_leaf,
+ .find = red_find,
+ .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,
+ .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");