/* * net/sched/sch_fifo.c The simplest FIFO 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, <kuznet@ms2.inr.ac.ru> */ #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/netdevice.h> #include <linux/skbuff.h> #include <net/pkt_sched.h> /* 1 band FIFO pseudo-"scheduler" */ struct fifo_sched_data { u32 limit; }; static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch) { struct fifo_sched_data *q = qdisc_priv(sch); if (likely(sch->qstats.backlog + skb->len <= q->limit)) return qdisc_enqueue_tail(skb, sch); return qdisc_reshape_fail(skb, sch); } static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch) { struct fifo_sched_data *q = qdisc_priv(sch); if (likely(skb_queue_len(&sch->q) < q->limit)) return qdisc_enqueue_tail(skb, sch); return qdisc_reshape_fail(skb, sch); } static int fifo_init(struct Qdisc *sch, struct rtattr *opt) { struct fifo_sched_data *q = qdisc_priv(sch); if (opt == NULL) { u32 limit = sch->dev->tx_queue_len ? : 1; if (sch->ops == &bfifo_qdisc_ops) limit *= sch->dev->mtu; q->limit = limit; } else { struct tc_fifo_qopt *ctl = RTA_DATA(opt); if (RTA_PAYLOAD(opt) < sizeof(*ctl)) return -EINVAL; q->limit = ctl->limit; } return 0; } static int fifo_dump(struct Qdisc *sch, struct sk_buff *skb) { struct fifo_sched_data *q = qdisc_priv(sch); struct tc_fifo_qopt opt = { .limit = q->limit }; RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); return skb->len; rtattr_failure: return -1; } struct Qdisc_ops pfifo_qdisc_ops = { .id = "pfifo", .priv_size = sizeof(struct fifo_sched_data), .enqueue = pfifo_enqueue, .dequeue = qdisc_dequeue_head, .requeue = qdisc_requeue, .drop = qdisc_queue_drop, .init = fifo_init, .reset = qdisc_reset_queue, .change = fifo_init, .dump = fifo_dump, .owner = THIS_MODULE, }; struct Qdisc_ops bfifo_qdisc_ops = { .id = "bfifo", .priv_size = sizeof(struct fifo_sched_data), .enqueue = bfifo_enqueue, .dequeue = qdisc_dequeue_head, .requeue = qdisc_requeue, .drop = qdisc_queue_drop, .init = fifo_init, .reset = qdisc_reset_queue, .change = fifo_init, .dump = fifo_dump, .owner = THIS_MODULE, }; EXPORT_SYMBOL(bfifo_qdisc_ops); EXPORT_SYMBOL(pfifo_qdisc_ops);