forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
164 lines
5.6 KiB
164 lines
5.6 KiB
#ifndef __NET_SCHED_CODEL_H |
|
#define __NET_SCHED_CODEL_H |
|
|
|
/* |
|
* Codel - The Controlled-Delay Active Queue Management algorithm |
|
* |
|
* Copyright (C) 2011-2012 Kathleen Nichols <[email protected]> |
|
* Copyright (C) 2011-2012 Van Jacobson <[email protected]> |
|
* Copyright (C) 2012 Michael D. Taht <[email protected]> |
|
* Copyright (C) 2012,2015 Eric Dumazet <[email protected]> |
|
* |
|
* Redistribution and use in source and binary forms, with or without |
|
* modification, are permitted provided that the following conditions |
|
* are met: |
|
* 1. Redistributions of source code must retain the above copyright |
|
* notice, this list of conditions, and the following disclaimer, |
|
* without modification. |
|
* 2. Redistributions in binary form must reproduce the above copyright |
|
* notice, this list of conditions and the following disclaimer in the |
|
* documentation and/or other materials provided with the distribution. |
|
* 3. The names of the authors may not be used to endorse or promote products |
|
* derived from this software without specific prior written permission. |
|
* |
|
* Alternatively, provided that this notice is retained in full, this |
|
* software may be distributed under the terms of the GNU General |
|
* Public License ("GPL") version 2, in which case the provisions of the |
|
* GPL apply INSTEAD OF those given above. |
|
* |
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
|
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
|
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
|
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
|
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH |
|
* DAMAGE. |
|
* |
|
*/ |
|
|
|
#include <linux/types.h> |
|
#include <linux/ktime.h> |
|
#include <linux/skbuff.h> |
|
#include <net/pkt_sched.h> |
|
#include <net/inet_ecn.h> |
|
|
|
/* Controlling Queue Delay (CoDel) algorithm |
|
* ========================================= |
|
* Source : Kathleen Nichols and Van Jacobson |
|
* http://queue.acm.org/detail.cfm?id=2209336 |
|
* |
|
* Implemented on linux by Dave Taht and Eric Dumazet |
|
*/ |
|
|
|
|
|
/* CoDel uses a 1024 nsec clock, encoded in u32 |
|
* This gives a range of 2199 seconds, because of signed compares |
|
*/ |
|
typedef u32 codel_time_t; |
|
typedef s32 codel_tdiff_t; |
|
#define CODEL_SHIFT 10 |
|
#define MS2TIME(a) ((a * NSEC_PER_MSEC) >> CODEL_SHIFT) |
|
|
|
static inline codel_time_t codel_get_time(void) |
|
{ |
|
u64 ns = ktime_get_ns(); |
|
|
|
return ns >> CODEL_SHIFT; |
|
} |
|
|
|
/* Dealing with timer wrapping, according to RFC 1982, as desc in wikipedia: |
|
* https://en.wikipedia.org/wiki/Serial_number_arithmetic#General_Solution |
|
* codel_time_after(a,b) returns true if the time a is after time b. |
|
*/ |
|
#define codel_time_after(a, b) \ |
|
(typecheck(codel_time_t, a) && \ |
|
typecheck(codel_time_t, b) && \ |
|
((s32)((a) - (b)) > 0)) |
|
#define codel_time_before(a, b) codel_time_after(b, a) |
|
|
|
#define codel_time_after_eq(a, b) \ |
|
(typecheck(codel_time_t, a) && \ |
|
typecheck(codel_time_t, b) && \ |
|
((s32)((a) - (b)) >= 0)) |
|
#define codel_time_before_eq(a, b) codel_time_after_eq(b, a) |
|
|
|
static inline u32 codel_time_to_us(codel_time_t val) |
|
{ |
|
u64 valns = ((u64)val << CODEL_SHIFT); |
|
|
|
do_div(valns, NSEC_PER_USEC); |
|
return (u32)valns; |
|
} |
|
|
|
/** |
|
* struct codel_params - contains codel parameters |
|
* @target: target queue size (in time units) |
|
* @ce_threshold: threshold for marking packets with ECN CE |
|
* @interval: width of moving time window |
|
* @mtu: device mtu, or minimal queue backlog in bytes. |
|
* @ecn: is Explicit Congestion Notification enabled |
|
*/ |
|
struct codel_params { |
|
codel_time_t target; |
|
codel_time_t ce_threshold; |
|
codel_time_t interval; |
|
u32 mtu; |
|
bool ecn; |
|
}; |
|
|
|
/** |
|
* struct codel_vars - contains codel variables |
|
* @count: how many drops we've done since the last time we |
|
* entered dropping state |
|
* @lastcount: count at entry to dropping state |
|
* @dropping: set to true if in dropping state |
|
* @rec_inv_sqrt: reciprocal value of sqrt(count) >> 1 |
|
* @first_above_time: when we went (or will go) continuously above target |
|
* for interval |
|
* @drop_next: time to drop next packet, or when we dropped last |
|
* @ldelay: sojourn time of last dequeued packet |
|
*/ |
|
struct codel_vars { |
|
u32 count; |
|
u32 lastcount; |
|
bool dropping; |
|
u16 rec_inv_sqrt; |
|
codel_time_t first_above_time; |
|
codel_time_t drop_next; |
|
codel_time_t ldelay; |
|
}; |
|
|
|
#define REC_INV_SQRT_BITS (8 * sizeof(u16)) /* or sizeof_in_bits(rec_inv_sqrt) */ |
|
/* needed shift to get a Q0.32 number from rec_inv_sqrt */ |
|
#define REC_INV_SQRT_SHIFT (32 - REC_INV_SQRT_BITS) |
|
|
|
/** |
|
* struct codel_stats - contains codel shared variables and stats |
|
* @maxpacket: largest packet we've seen so far |
|
* @drop_count: temp count of dropped packets in dequeue() |
|
* @drop_len: bytes of dropped packets in dequeue() |
|
* ecn_mark: number of packets we ECN marked instead of dropping |
|
* ce_mark: number of packets CE marked because sojourn time was above ce_threshold |
|
*/ |
|
struct codel_stats { |
|
u32 maxpacket; |
|
u32 drop_count; |
|
u32 drop_len; |
|
u32 ecn_mark; |
|
u32 ce_mark; |
|
}; |
|
|
|
#define CODEL_DISABLED_THRESHOLD INT_MAX |
|
|
|
typedef u32 (*codel_skb_len_t)(const struct sk_buff *skb); |
|
typedef codel_time_t (*codel_skb_time_t)(const struct sk_buff *skb); |
|
typedef void (*codel_skb_drop_t)(struct sk_buff *skb, void *ctx); |
|
typedef struct sk_buff * (*codel_skb_dequeue_t)(struct codel_vars *vars, |
|
void *ctx); |
|
|
|
#endif
|
|
|