linux/net/sched/sch_skbprio.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * net/sched/sch_skbprio.c  SKB Priority Queue.
 *
 * Authors:	Nishanth Devarajan, <[email protected]>
 *		Cody Doucette, <[email protected]>
 *	        original idea by Michel Machado, Cody Doucette, and Qiaobin Fu
 */

#include <linux/string.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <net/pkt_sched.h>
#include <net/sch_generic.h>
#include <net/inet_ecn.h>

/*		SKB Priority Queue
 *	=================================
 *
 * Skbprio (SKB Priority Queue) is a queueing discipline that prioritizes
 * packets according to their skb->priority field. Under congestion,
 * Skbprio drops already-enqueued lower priority packets to make space
 * available for higher priority packets; it was conceived as a solution
 * for denial-of-service defenses that need to route packets with different
 * priorities as a mean to overcome DoS attacks.
 */

struct skbprio_sched_data { … };

static u16 calc_new_high_prio(const struct skbprio_sched_data *q)
{ … }

static u16 calc_new_low_prio(const struct skbprio_sched_data *q)
{ … }

static int skbprio_enqueue(struct sk_buff *skb, struct Qdisc *sch,
			  struct sk_buff **to_free)
{ … }

static struct sk_buff *skbprio_dequeue(struct Qdisc *sch)
{ … }

static int skbprio_change(struct Qdisc *sch, struct nlattr *opt,
			struct netlink_ext_ack *extack)
{ … }

static int skbprio_init(struct Qdisc *sch, struct nlattr *opt,
			struct netlink_ext_ack *extack)
{ … }

static int skbprio_dump(struct Qdisc *sch, struct sk_buff *skb)
{ … }

static void skbprio_reset(struct Qdisc *sch)
{ … }

static void skbprio_destroy(struct Qdisc *sch)
{ … }

static struct Qdisc *skbprio_leaf(struct Qdisc *sch, unsigned long arg)
{ … }

static unsigned long skbprio_find(struct Qdisc *sch, u32 classid)
{ … }

static int skbprio_dump_class(struct Qdisc *sch, unsigned long cl,
			     struct sk_buff *skb, struct tcmsg *tcm)
{ … }

static int skbprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
				   struct gnet_dump *d)
{ … }

static void skbprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{ … }

static const struct Qdisc_class_ops skbprio_class_ops = …;

static struct Qdisc_ops skbprio_qdisc_ops __read_mostly = …;
MODULE_ALIAS_NET_SCH(…) …;

static int __init skbprio_module_init(void)
{ … }

static void __exit skbprio_module_exit(void)
{ … }

module_init(…) …
module_exit(…)

MODULE_LICENSE(…) …;
MODULE_DESCRIPTION(…) …;