LXR linux/include/net/codel

   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[] */
  53struct codel_skb_cb {
  54        codel_time_t enqueue_time;
  55        unsigned int mem_usage;
  56};
  57
  58static 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
  64static codel_time_t codel_get_enqueue_time(const struct sk_buff *skb)
  65{
  66        return get_codel_cb(skb)->enqueue_time;
  67}
  68
  69static void codel_set_enqueue_time(struct sk_buff *skb)
  70{
  71        get_codel_cb(skb)->enqueue_time = codel_get_time();
  72}
  73
  74#endif
  75