1/*
  2 * CoDel - The Controlled-Delay Active Queue Management algorithm
  3 *
  4 *  Copyright (C) 2013 Ermal Luçi <eri@FreeBSD.org>
  5 *  Copyright (C) 2011-2012 Kathleen Nichols <nichols@pollere.com>
  6 *  Copyright (C) 2011-2012 Van Jacobson <van@pollere.net>
  7 *  Copyright (C) 2012 Michael D. Taht <dave.taht@bufferbloat.net>
  8 *  Copyright (C) 2012 Eric Dumazet <edumazet@google.com>
  9 *
 10 * Redistribution and use in source and binary forms, with or without
 11 * modification, are permitted provided that the following conditions
 12 * are met:
 13 * 1. Redistributions of source code must retain the above copyright
 14 *    notice, this list of conditions, and the following disclaimer,
 15 *    without modification.
 16 * 2. Redistributions in binary form must reproduce the above copyright
 17 *    notice, this list of conditions and the following disclaimer in the
 18 *    documentation and/or other materials provided with the distribution.
 19 * 3. The names of the authors may not be used to endorse or promote products
 20 *    derived from this software without specific prior written permission.
 21 *
 22 * Alternatively, provided that this notice is retained in full, this
 23 * software may be distributed under the terms of the GNU General
 24 * Public License ("GPL") version 2, in which case the provisions of the
 25 * GPL apply INSTEAD OF those given above.
 26 *
 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 38 * DAMAGE.
 39 */
 40
 41#ifndef _ALTQ_ALTQ_CODEL_H_
 42#define	_ALTQ_ALTQ_CODEL_H_
 43
 44struct codel_stats {
 45	u_int32_t	maxpacket;
 46	struct pktcntr	drop_cnt;
 47	u_int		marked_packets;
 48};
 49
 50struct codel_ifstats {
 51	u_int			qlength;
 52	u_int			qlimit;
 53	struct codel_stats	stats;
 54	struct pktcntr	cl_xmitcnt;	/* transmitted packet counter */
 55	struct pktcntr	cl_dropcnt;	/* dropped packet counter */
 56};
 57
 58/*
 59 * CBQ_STATS_VERSION is defined in altq.h to work around issues stemming
 60 * from mixing of public-API and internal bits in each scheduler-specific
 61 * header.
 62 */
 63
 64#ifdef _KERNEL
 65#include <net/altq/altq_classq.h>
 66
 67/**
 68 * struct codel_params - contains codel parameters
 69 *  <at> target:	target queue size (in time units)
 70 *  <at> interval:	width of moving time window
 71 *  <at> ecn:	is Explicit Congestion Notification enabled
 72 */
 73struct codel_params {
 74	u_int64_t	target;
 75	u_int64_t	interval;
 76	int		ecn;
 77};
 78
 79/**
 80 * struct codel_vars - contains codel variables
 81 *  <at> count:		how many drops we've done since the last time we
 82 *			entered dropping state
 83 *  <at> lastcount:	count at entry to dropping state
 84 *  <at> dropping:	set to true if in dropping state
 85 *  <at> rec_inv_sqrt:	reciprocal value of sqrt(count) >> 1
 86 *  <at> first_above_time:	when we went (or will go) continuously above
 87 *				target for interval
 88 *  <at> drop_next:	time to drop next packet, or when we dropped last
 89 *  <at> ldelay:	sojourn time of last dequeued packet
 90 */
 91struct codel_vars {
 92	u_int32_t	count;
 93	u_int32_t	lastcount;
 94	int		dropping;
 95	u_int16_t	rec_inv_sqrt;
 96	u_int64_t	first_above_time;
 97	u_int64_t	drop_next;
 98	u_int64_t	ldelay;
 99};
100        
101struct codel {
102	int			last_pps;
103	struct codel_params	params;
104	struct codel_vars	vars;
105	struct codel_stats	stats;
106	struct timeval		last_log;
107	u_int32_t		drop_overlimit;
108};
109
110/*
111 * codel interface state
112 */
113struct codel_if {
114	struct codel_if		*cif_next;	/* interface state list */
115	struct ifaltq		*cif_ifq;	/* backpointer to ifaltq */
116	u_int			cif_bandwidth;	/* link bandwidth in bps */
117
118	class_queue_t	*cl_q;		/* class queue structure */
119	struct codel	codel;
120
121	/* statistics */
122	struct codel_ifstats cl_stats;
123};
124
125struct codel	*codel_alloc(int, int, int);
126void		 codel_destroy(struct codel *);
127int		 codel_addq(struct codel *, class_queue_t *, struct mbuf *);
128struct mbuf	*codel_getq(struct codel *, class_queue_t *);
129void		 codel_getstats(struct codel *, struct codel_stats *);
130
131#endif /* _KERNEL */
132
133#endif /* _ALTQ_ALTQ_CODEL_H_ */