xref: /openbmc/linux/include/net/codel_qdisc.h (revision 949d6b40)
1 #ifndef __NET_SCHED_CODEL_QDISC_H
2 #define __NET_SCHED_CODEL_QDISC_H
3 
4 /*
5  * Codel - The Controlled-Delay Active Queue Management algorithm
6  *
7  *  Copyright (C) 2011-2012 Kathleen Nichols <nichols@pollere.com>
8  *  Copyright (C) 2011-2012 Van Jacobson <van@pollere.net>
9  *  Copyright (C) 2012 Michael D. Taht <dave.taht@bufferbloat.net>
10  *  Copyright (C) 2012,2015 Eric Dumazet <edumazet@google.com>
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions, and the following disclaimer,
17  *    without modification.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. The names of the authors may not be used to endorse or promote products
22  *    derived from this software without specific prior written permission.
23  *
24  * Alternatively, provided that this notice is retained in full, this
25  * software may be distributed under the terms of the GNU General
26  * Public License ("GPL") version 2, in which case the provisions of the
27  * GPL apply INSTEAD OF those given above.
28  *
29  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
30  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
31  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
32  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
33  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
34  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
35  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
39  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
40  * DAMAGE.
41  *
42  */
43 
44 /* Controlling Queue Delay (CoDel) algorithm
45  * =========================================
46  * Source : Kathleen Nichols and Van Jacobson
47  * http://queue.acm.org/detail.cfm?id=2209336
48  *
49  * Implemented on linux by Dave Taht and Eric Dumazet
50  */
51 
52 #include <net/codel.h>
53 #include <net/pkt_sched.h>
54 
55 /* Qdiscs using codel plugin must use codel_skb_cb in their own cb[] */
56 struct codel_skb_cb {
57 	codel_time_t enqueue_time;
58 	unsigned int mem_usage;
59 };
60 
get_codel_cb(const struct sk_buff * skb)61 static struct codel_skb_cb *get_codel_cb(const struct sk_buff *skb)
62 {
63 	qdisc_cb_private_validate(skb, sizeof(struct codel_skb_cb));
64 	return (struct codel_skb_cb *)qdisc_skb_cb(skb)->data;
65 }
66 
codel_get_enqueue_time(const struct sk_buff * skb)67 static codel_time_t codel_get_enqueue_time(const struct sk_buff *skb)
68 {
69 	return get_codel_cb(skb)->enqueue_time;
70 }
71 
codel_set_enqueue_time(struct sk_buff * skb)72 static void codel_set_enqueue_time(struct sk_buff *skb)
73 {
74 	get_codel_cb(skb)->enqueue_time = codel_get_time();
75 }
76 
77 #endif
78