--- /dev/null
+/*
+ * net/sched/sch_prio.c Simple 3-band priority "scheduler".
+ *
+ * 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, <kuznet@ms2.inr.ac.ru>
+ * Fixes: 19990609: J Hadi Salim <hadi@nortelnetworks.com>:
+ * Init -- EINVAL when opt undefined
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+
+
+struct prio_sched_data {
+ int bands;
+ struct tcf_proto __rcu *filter_list;
+ u8 prio2band[TC_PRIO_MAX+1];
+ struct Qdisc *queues[TCQ_PRIO_BANDS];
+};
+
+
+static struct Qdisc *
+prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+ u32 band = skb->priority;
+ struct tcf_result res;
+ struct tcf_proto *fl;
+ int err;
+
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
+ if (TC_H_MAJ(skb->priority) != sch->handle) {
+ fl = rcu_dereference_bh(q->filter_list);
+ err = tc_classify(skb, fl, &res);
+#ifdef CONFIG_NET_CLS_ACT
+ switch (err) {
+ case TC_ACT_STOLEN:
+ case TC_ACT_QUEUED:
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
+ case TC_ACT_SHOT:
+ return NULL;
+ }
+#endif
+ if (!fl || err < 0) {
+ if (TC_H_MAJ(band))
+ band = 0;
+ return q->queues[q->prio2band[band & TC_PRIO_MAX]];
+ }
+ band = res.classid;
+ }
+ band = TC_H_MIN(band) - 1;
+ if (band >= q->bands)
+ return q->queues[q->prio2band[0]];
+
+ return q->queues[band];
+}
+
+static int
+prio_enqueue(struct sk_buff *skb, struct Qdisc *sch)
+{
+ struct Qdisc *qdisc;
+ int ret;
+
+ qdisc = prio_classify(skb, sch, &ret);
+#ifdef CONFIG_NET_CLS_ACT
+ if (qdisc == NULL) {
+
+ if (ret & __NET_XMIT_BYPASS)
+ qdisc_qstats_drop(sch);
+ kfree_skb(skb);
+ return ret;
+ }
+#endif
+
+ ret = qdisc_enqueue(skb, qdisc);
+ if (ret == NET_XMIT_SUCCESS) {
+ sch->q.qlen++;
+ return NET_XMIT_SUCCESS;
+ }
+ if (net_xmit_drop_count(ret))
+ qdisc_qstats_drop(sch);
+ return ret;
+}
+
+static struct sk_buff *prio_peek(struct Qdisc *sch)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+ int prio;
+
+ for (prio = 0; prio < q->bands; prio++) {
+ struct Qdisc *qdisc = q->queues[prio];
+ struct sk_buff *skb = qdisc->ops->peek(qdisc);
+ if (skb)
+ return skb;
+ }
+ return NULL;
+}
+
+static struct sk_buff *prio_dequeue(struct Qdisc *sch)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+ int prio;
+
+ for (prio = 0; prio < q->bands; prio++) {
+ struct Qdisc *qdisc = q->queues[prio];
+ struct sk_buff *skb = qdisc_dequeue_peeked(qdisc);
+ if (skb) {
+ qdisc_bstats_update(sch, skb);
+ sch->q.qlen--;
+ return skb;
+ }
+ }
+ return NULL;
+
+}
+
+static unsigned int prio_drop(struct Qdisc *sch)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+ int prio;
+ unsigned int len;
+ struct Qdisc *qdisc;
+
+ for (prio = q->bands-1; prio >= 0; prio--) {
+ qdisc = q->queues[prio];
+ if (qdisc->ops->drop && (len = qdisc->ops->drop(qdisc)) != 0) {
+ sch->q.qlen--;
+ return len;
+ }
+ }
+ return 0;
+}
+
+
+static void
+prio_reset(struct Qdisc *sch)
+{
+ int prio;
+ struct prio_sched_data *q = qdisc_priv(sch);
+
+ for (prio = 0; prio < q->bands; prio++)
+ qdisc_reset(q->queues[prio]);
+ sch->q.qlen = 0;
+}
+
+static void
+prio_destroy(struct Qdisc *sch)
+{
+ int prio;
+ struct prio_sched_data *q = qdisc_priv(sch);
+
+ tcf_destroy_chain(&q->filter_list);
+ for (prio = 0; prio < q->bands; prio++)
+ qdisc_destroy(q->queues[prio]);
+}
+
+static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+ struct tc_prio_qopt *qopt;
+ int i;
+
+ if (nla_len(opt) < sizeof(*qopt))
+ return -EINVAL;
+ qopt = nla_data(opt);
+
+ if (qopt->bands > TCQ_PRIO_BANDS || qopt->bands < 2)
+ return -EINVAL;
+
+ for (i = 0; i <= TC_PRIO_MAX; i++) {
+ if (qopt->priomap[i] >= qopt->bands)
+ return -EINVAL;
+ }
+
+ sch_tree_lock(sch);
+ q->bands = qopt->bands;
+ memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
+
+ for (i = q->bands; i < TCQ_PRIO_BANDS; i++) {
+ struct Qdisc *child = q->queues[i];
+ q->queues[i] = &noop_qdisc;
+ if (child != &noop_qdisc) {
+ qdisc_tree_decrease_qlen(child, child->q.qlen);
+ qdisc_destroy(child);
+ }
+ }
+ sch_tree_unlock(sch);
+
+ for (i = 0; i < q->bands; i++) {
+ if (q->queues[i] == &noop_qdisc) {
+ struct Qdisc *child, *old;
+
+ child = qdisc_create_dflt(sch->dev_queue,
+ &pfifo_qdisc_ops,
+ TC_H_MAKE(sch->handle, i + 1));
+ if (child) {
+ sch_tree_lock(sch);
+ old = q->queues[i];
+ q->queues[i] = child;
+
+ if (old != &noop_qdisc) {
+ qdisc_tree_decrease_qlen(old,
+ old->q.qlen);
+ qdisc_destroy(old);
+ }
+ sch_tree_unlock(sch);
+ }
+ }
+ }
+ return 0;
+}
+
+static int prio_init(struct Qdisc *sch, struct nlattr *opt)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+ int i;
+
+ for (i = 0; i < TCQ_PRIO_BANDS; i++)
+ q->queues[i] = &noop_qdisc;
+
+ if (opt == NULL) {
+ return -EINVAL;
+ } else {
+ int err;
+
+ if ((err = prio_tune(sch, opt)) != 0)
+ return err;
+ }
+ return 0;
+}
+
+static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+ unsigned char *b = skb_tail_pointer(skb);
+ struct tc_prio_qopt opt;
+
+ opt.bands = q->bands;
+ memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX + 1);
+
+ if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
+ goto nla_put_failure;
+
+ return skb->len;
+
+nla_put_failure:
+ nlmsg_trim(skb, b);
+ return -1;
+}
+
+static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
+ struct Qdisc **old)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+ unsigned long band = arg - 1;
+
+ if (new == NULL)
+ new = &noop_qdisc;
+
+ sch_tree_lock(sch);
+ *old = q->queues[band];
+ q->queues[band] = new;
+ qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
+ qdisc_reset(*old);
+ sch_tree_unlock(sch);
+
+ return 0;
+}
+
+static struct Qdisc *
+prio_leaf(struct Qdisc *sch, unsigned long arg)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+ unsigned long band = arg - 1;
+
+ return q->queues[band];
+}
+
+static unsigned long prio_get(struct Qdisc *sch, u32 classid)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+ unsigned long band = TC_H_MIN(classid);
+
+ if (band - 1 >= q->bands)
+ return 0;
+ return band;
+}
+
+static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
+{
+ return prio_get(sch, classid);
+}
+
+
+static void prio_put(struct Qdisc *q, unsigned long cl)
+{
+}
+
+static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb,
+ struct tcmsg *tcm)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+
+ tcm->tcm_handle |= TC_H_MIN(cl);
+ tcm->tcm_info = q->queues[cl-1]->handle;
+ return 0;
+}
+
+static int prio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
+ struct gnet_dump *d)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+ struct Qdisc *cl_q;
+
+ cl_q = q->queues[cl - 1];
+ if (gnet_stats_copy_basic(d, NULL, &cl_q->bstats) < 0 ||
+ gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0)
+ return -1;
+
+ return 0;
+}
+
+static void prio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+ int prio;
+
+ if (arg->stop)
+ return;
+
+ for (prio = 0; prio < q->bands; prio++) {
+ if (arg->count < arg->skip) {
+ arg->count++;
+ continue;
+ }
+ if (arg->fn(sch, prio + 1, arg) < 0) {
+ arg->stop = 1;
+ break;
+ }
+ arg->count++;
+ }
+}
+
+static struct tcf_proto __rcu **prio_find_tcf(struct Qdisc *sch,
+ unsigned long cl)
+{
+ struct prio_sched_data *q = qdisc_priv(sch);
+
+ if (cl)
+ return NULL;
+ return &q->filter_list;
+}
+
+static const struct Qdisc_class_ops prio_class_ops = {
+ .graft = prio_graft,
+ .leaf = prio_leaf,
+ .get = prio_get,
+ .put = prio_put,
+ .walk = prio_walk,
+ .tcf_chain = prio_find_tcf,
+ .bind_tcf = prio_bind,
+ .unbind_tcf = prio_put,
+ .dump = prio_dump_class,
+ .dump_stats = prio_dump_class_stats,
+};
+
+static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
+ .next = NULL,
+ .cl_ops = &prio_class_ops,
+ .id = "prio",
+ .priv_size = sizeof(struct prio_sched_data),
+ .enqueue = prio_enqueue,
+ .dequeue = prio_dequeue,
+ .peek = prio_peek,
+ .drop = prio_drop,
+ .init = prio_init,
+ .reset = prio_reset,
+ .destroy = prio_destroy,
+ .change = prio_tune,
+ .dump = prio_dump,
+ .owner = THIS_MODULE,
+};
+
+static int __init prio_module_init(void)
+{
+ return register_qdisc(&prio_qdisc_ops);
+}
+
+static void __exit prio_module_exit(void)
+{
+ unregister_qdisc(&prio_qdisc_ops);
+}
+
+module_init(prio_module_init)
+module_exit(prio_module_exit)
+
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff