/* * 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/config.h> #include <linux/module.h> #include <asm/uaccess.h> #include <asm/system.h> #include <linux/bitops.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/socket.h> #include <linux/sockios.h> #include <linux/in.h> #include <linux/errno.h> #include <linux/interrupt.h> #include <linux/if_ether.h> #include <linux/inet.h> #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/notifier.h> #include <net/ip.h> #include <net/route.h> #include <linux/skbuff.h> #include <net/sock.h> #include <net/pkt_sched.h> struct prio_sched_data { int bands; struct tcf_proto *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; *qerr = NET_XMIT_DROP; if (TC_H_MAJ(skb->priority) != sch->handle) { #ifdef CONFIG_NET_CLS_ACT switch (tc_classify(skb, q->filter_list, &res)) { case TC_ACT_STOLEN: case TC_ACT_QUEUED: *qerr = NET_XMIT_SUCCESS; case TC_ACT_SHOT: return NULL; }; if (!q->filter_list ) { #else if (!q->filter_list || tc_classify(skb, q->filter_list, &res)) { #endif 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_DROP) sch->qstats.drops++; kfree_skb(skb); return ret; } #endif if ((ret = qdisc->enqueue(skb, qdisc)) == NET_XMIT_SUCCESS) { sch->bstats.bytes += skb->len; sch->bstats.packets++; sch->q.qlen++; return NET_XMIT_SUCCESS; } sch->qstats.drops++; return ret; } static int prio_requeue(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_DROP) sch->qstats.drops++; kfree_skb(skb); return ret; } #endif if ((ret = qdisc->ops->requeue(skb, qdisc)) == NET_XMIT_SUCCESS) { sch->q.qlen++; sch->qstats.requeues++; return 0; } sch->qstats.drops++; return NET_XMIT_DROP; } static struct sk_buff * prio_dequeue(struct Qdisc* sch) { struct sk_buff *skb; struct prio_sched_data *q = qdisc_priv(sch); int prio; struct Qdisc *qdisc; for (prio = 0; prio < q->bands; prio++) { qdisc = q->queues[prio]; skb = qdisc->dequeue(qdisc); if (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 ((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); struct tcf_proto *tp; while ((tp = q->filter_list) != NULL) { q->filter_list = tp->next; tcf_destroy(tp); } for (prio=0; prio<q->bands; prio++) qdisc_destroy(q->queues[prio]); } static int prio_tune(struct Qdisc *sch, struct rtattr *opt) { struct prio_sched_data *q = qdisc_priv(sch); struct tc_prio_qopt *qopt = RTA_DATA(opt); int i; if (opt->rta_len < RTA_LENGTH(sizeof(*qopt))) return -EINVAL; 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 = xchg(&q->queues[i], &noop_qdisc); if (child != &noop_qdisc) qdisc_destroy(child); } sch_tree_unlock(sch); for (i=0; i<=TC_PRIO_MAX; i++) { int band = q->prio2band[i]; if (q->queues[band] == &noop_qdisc) { struct Qdisc *child; child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops); if (child) { sch_tree_lock(sch); child = xchg(&q->queues[band], child); if (child != &noop_qdisc) qdisc_destroy(child); sch_tree_unlock(sch); } } } return 0; } static int prio_init(struct Qdisc *sch, struct rtattr *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; struct tc_prio_qopt opt; opt.bands = q->bands; memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX+1); RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); return skb->len; rtattr_failure: skb_trim(skb, b - skb->data); 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 (band >= q->bands) return -EINVAL; if (new == NULL) new = &noop_qdisc; sch_tree_lock(sch); *old = q->queues[band]; q->queues[band] = new; sch->q.qlen -= (*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; if (band >= q->bands) return NULL; 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) { return; } static int prio_change(struct Qdisc *sch, u32 handle, u32 parent, struct rtattr **tca, unsigned long *arg) { unsigned long cl = *arg; struct prio_sched_data *q = qdisc_priv(sch); if (cl - 1 > q->bands) return -ENOENT; return 0; } static int prio_delete(struct Qdisc *sch, unsigned long cl) { struct prio_sched_data *q = qdisc_priv(sch); if (cl - 1 > q->bands) return -ENOENT; return 0; } 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); if (cl - 1 > q->bands) return -ENOENT; tcm->tcm_handle |= TC_H_MIN(cl); if (q->queues[cl-1]) tcm->tcm_info = q->queues[cl-1]->handle; 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 ** 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 struct Qdisc_class_ops prio_class_ops = { .graft = prio_graft, .leaf = prio_leaf, .get = prio_get, .put = prio_put, .change = prio_change, .delete = prio_delete, .walk = prio_walk, .tcf_chain = prio_find_tcf, .bind_tcf = prio_bind, .unbind_tcf = prio_put, .dump = prio_dump_class, }; static struct Qdisc_ops prio_qdisc_ops = { .next = NULL, .cl_ops = &prio_class_ops, .id = "prio", .priv_size = sizeof(struct prio_sched_data), .enqueue = prio_enqueue, .dequeue = prio_dequeue, .requeue = prio_requeue, .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");