2 * net/sched/sch_fifo.c The simplest FIFO queue.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
12 #include <linux/config.h>
13 #include <linux/module.h>
14 #include <asm/uaccess.h>
15 #include <asm/system.h>
16 #include <asm/bitops.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/sched.h>
20 #include <linux/string.h>
22 #include <linux/socket.h>
23 #include <linux/sockios.h>
25 #include <linux/errno.h>
26 #include <linux/interrupt.h>
27 #include <linux/if_ether.h>
28 #include <linux/inet.h>
29 #include <linux/netdevice.h>
30 #include <linux/etherdevice.h>
31 #include <linux/notifier.h>
33 #include <net/route.h>
34 #include <linux/skbuff.h>
36 #include <net/pkt_sched.h>
38 /* 1 band FIFO pseudo-"scheduler" */
40 struct fifo_sched_data
46 bfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
48 struct fifo_sched_data *q = qdisc_priv(sch);
50 if (sch->stats.backlog + skb->len <= q->limit) {
51 __skb_queue_tail(&sch->q, skb);
52 sch->stats.backlog += skb->len;
53 sch->stats.bytes += skb->len;
58 #ifdef CONFIG_NET_CLS_POLICE
59 if (sch->reshape_fail==NULL || sch->reshape_fail(skb, sch))
66 bfifo_requeue(struct sk_buff *skb, struct Qdisc* sch)
68 __skb_queue_head(&sch->q, skb);
69 sch->stats.backlog += skb->len;
73 static struct sk_buff *
74 bfifo_dequeue(struct Qdisc* sch)
78 skb = __skb_dequeue(&sch->q);
80 sch->stats.backlog -= skb->len;
85 fifo_drop(struct Qdisc* sch)
89 skb = __skb_dequeue_tail(&sch->q);
91 unsigned int len = skb->len;
92 sch->stats.backlog -= len;
100 fifo_reset(struct Qdisc* sch)
102 skb_queue_purge(&sch->q);
103 sch->stats.backlog = 0;
107 pfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
109 struct fifo_sched_data *q = qdisc_priv(sch);
111 if (sch->q.qlen < q->limit) {
112 __skb_queue_tail(&sch->q, skb);
113 sch->stats.bytes += skb->len;
114 sch->stats.packets++;
118 #ifdef CONFIG_NET_CLS_POLICE
119 if (sch->reshape_fail==NULL || sch->reshape_fail(skb, sch))
122 return NET_XMIT_DROP;
126 pfifo_requeue(struct sk_buff *skb, struct Qdisc* sch)
128 __skb_queue_head(&sch->q, skb);
133 static struct sk_buff *
134 pfifo_dequeue(struct Qdisc* sch)
136 return __skb_dequeue(&sch->q);
139 static int fifo_init(struct Qdisc *sch, struct rtattr *opt)
141 struct fifo_sched_data *q = qdisc_priv(sch);
144 unsigned int limit = sch->dev->tx_queue_len ? : 1;
146 if (sch->ops == &bfifo_qdisc_ops)
147 q->limit = limit*sch->dev->mtu;
151 struct tc_fifo_qopt *ctl = RTA_DATA(opt);
152 if (opt->rta_len < RTA_LENGTH(sizeof(*ctl)))
154 q->limit = ctl->limit;
159 static int fifo_dump(struct Qdisc *sch, struct sk_buff *skb)
161 struct fifo_sched_data *q = qdisc_priv(sch);
162 unsigned char *b = skb->tail;
163 struct tc_fifo_qopt opt;
165 opt.limit = q->limit;
166 RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
171 skb_trim(skb, b - skb->data);
175 struct Qdisc_ops pfifo_qdisc_ops = {
179 .priv_size = sizeof(struct fifo_sched_data),
180 .enqueue = pfifo_enqueue,
181 .dequeue = pfifo_dequeue,
182 .requeue = pfifo_requeue,
189 .owner = THIS_MODULE,
192 struct Qdisc_ops bfifo_qdisc_ops = {
196 .priv_size = sizeof(struct fifo_sched_data),
197 .enqueue = bfifo_enqueue,
198 .dequeue = bfifo_dequeue,
199 .requeue = bfifo_requeue,
206 .owner = THIS_MODULE,
209 EXPORT_SYMBOL(bfifo_qdisc_ops);
210 EXPORT_SYMBOL(pfifo_qdisc_ops);