include/net/codel_qdisc.h

   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 /* Qdiscs using codel plugin must use codel_skb_cb in their own cb[] */
  53 struct codel_skb_cb {
  54         codel_time_t enqueue_time;
  55         unsigned int mem_usage;
  56 };
  57
  58 static struct codel_skb_cb *get_codel_cb(const struct sk_buff *skb)
  59 {
  60         qdisc_cb_private_validate(skb, sizeof(struct codel_skb_cb));
  61         return (struct codel_skb_cb *)qdisc_skb_cb(skb)->data;
  62 }
  63
  64 static codel_time_t codel_get_enqueue_time(const struct sk_buff *skb)
  65 {
  66         return get_codel_cb(skb)->enqueue_time;
  67 }
  68
  69 static void codel_set_enqueue_time(struct sk_buff *skb)
  70 {
  71         get_codel_cb(skb)->enqueue_time = codel_get_time();
  72 }
  73
  74 #endif