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 * Copyright (c) 2011-2020 Apple Inc. All rights reserved.
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 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
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#ifndef _NET_CLASSQ_CLASSQ_SFB_H_
#define _NET_CLASSQ_CLASSQ_SFB_H_

#ifdef PRIVATE
#ifdef BSD_KERNEL_PRIVATE
#include <stdbool.h>
#include <sys/time.h>
#include <net/flowadv.h>
#include <net/classq/if_classq.h>
#endif /* BSD_KERNEL_PRIVATE */

#ifdef __cplusplus
extern "C" {
#endif

#define SFB_FP_SHIFT    14                      /* fixed-point shift (Q14) */
#define SFB_LEVELS      2                       /* L */
#define SFB_BINS_SHIFT  5
#define SFB_BINS        (1 << SFB_BINS_SHIFT)   /* N */

struct sfbstats {
	u_int64_t               drop_early;
	u_int64_t               drop_pbox;
	u_int64_t               drop_queue;
	u_int64_t               marked_packets;
	u_int64_t               pbox_packets;
	u_int64_t               pbox_time;
	u_int64_t               hold_time;
	u_int64_t               dequeue_avg;
	u_int64_t               rehash_intval;
	u_int64_t               num_rehash;
	u_int64_t               null_flowid;
	u_int64_t               flow_controlled;
	u_int64_t               flow_feedback;
	u_int64_t               dequeue_stall;
};

struct sfbbinstats {
	int16_t         pmark;          /* marking probability in Q format */
	u_int16_t       pkts;           /* number of packets */
	u_int32_t       bytes;          /* number of bytes */
};

struct sfb_stats {
	u_int32_t               allocation;
	u_int32_t               dropthresh;
	u_int32_t               clearpkts;
	u_int32_t               current;
	u_int64_t               target_qdelay;
	u_int64_t               update_interval;
	u_int64_t               min_estdelay;
	u_int32_t               delay_fcthreshold;
	u_int32_t               flags;
	struct sfbstats         sfbstats;
	struct sfbbins {
		struct sfbbinstats stats[SFB_LEVELS][SFB_BINS];
	} binstats[2] __attribute__((aligned(8)));
};

#ifdef BSD_KERNEL_PRIVATE
struct sfb_bins {
	u_int32_t               fudge;
	struct sfbbinstats      stats[SFB_LEVELS][SFB_BINS];
	struct timespec         freezetime[SFB_LEVELS][SFB_BINS];
};

struct sfb_fcl {
	u_int32_t               cnt;
	struct flowadv_fclist   fclist;
};

/* SFB flags */
#define SFBF_ECN4       0x01    /* use packet marking for IPv4 packets */
#define SFBF_ECN6       0x02    /* use packet marking for IPv6 packets */
#define SFBF_ECN        (SFBF_ECN4 | SFBF_ECN6)
#define SFBF_FLOWCTL    0x04    /* enable flow control advisories */
#define SFBF_DELAYBASED 0x08    /* queueing is delay based */
#define SFBF_DELAYHIGH  0x10    /* Estimated delay is greater than target */
#define SFBF_LAST_PKT_DROPPED   0x20    /* Last packet dropped */
#define SFBF_SUSPENDED  0x1000  /* queue is suspended */

#define SFBF_USERFLAGS                                                  \
	(SFBF_ECN4 | SFBF_ECN6 | SFBF_FLOWCTL | SFBF_DELAYBASED)

typedef struct sfb {
	/* variables for internal use */
	u_int32_t       sfb_flags;      /* SFB flags */
	u_int32_t       sfb_qlim;
	u_int32_t       sfb_qid;
	u_int16_t       sfb_allocation;
	u_int16_t       sfb_drop_thresh;
	u_int32_t       sfb_clearpkts;
	u_int64_t       sfb_eff_rate;   /* last known effective rate */
	struct timespec sfb_getqtime;   /* last dequeue timestamp */
	struct timespec sfb_holdtime;   /* random holdtime in nsec */
	struct ifnet    *sfb_ifp;       /* back pointer to ifnet */

	/* target queue delay and interval for queue sizing */
	u_int64_t       sfb_target_qdelay;
	struct timespec sfb_update_interval;
	u_int64_t       sfb_fc_threshold; /* for flow control feedback */

	/* variables for computing estimated delay of the queue */
	u_int64_t       sfb_min_qdelay;
	struct timespec sfb_update_time;

	/* moving hash function */
	struct timespec sfb_hinterval;  /* random reset interval in sec */
	struct timespec sfb_nextreset;  /* reset deadline */

	/* penalty box */
	struct timespec sfb_pboxtime;   /* random pboxtime in nsec */
	struct timespec sfb_pboxfreeze;

	/* B[L][N] bins (2 sets: current and warm-up) */
	u_int32_t       sfb_current;    /* current set (0 or 1) */
	struct sfb_bins (*sfb_bins)[ 2];

	/* Flow control lists for current set */
	struct sfb_fcl  (*sfb_fc_lists)[ SFB_BINS];

	/* statistics */
	struct sfbstats sfb_stats __attribute__((aligned(8)));
} sfb_t;

extern struct sfb *sfb_alloc(struct ifnet *, u_int32_t, u_int32_t, u_int32_t);
extern void sfb_destroy(struct sfb *);
extern int sfb_addq(struct sfb *, class_queue_t *, pktsched_pkt_t *,
    struct pf_mtag *);
extern void sfb_getq(struct sfb *, class_queue_t *, pktsched_pkt_t *);
extern void sfb_purgeq(struct sfb *, class_queue_t *, u_int32_t,
    u_int32_t *, u_int32_t *);
extern void sfb_getstats(struct sfb *, struct sfb_stats *);
extern void sfb_updateq(struct sfb *, cqev_t);
extern int sfb_suspendq(struct sfb *, class_queue_t *, boolean_t);
#endif /* BSD_KERNEL_PRIVATE */

#ifdef __cplusplus
}
#endif
#endif /* PRIVATE */
#endif /* _NET_CLASSQ_CLASSQ_SFB_H_ */
