xnu-7195.81.3.tar.gz

[apple/xnu.git] / bsd / netinet / ip_dummynet.c

/*
 * Copyright (c) 2000-2019 Apple Inc. All rights reserved.
 *
 * @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
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1998-2002 Luigi Rizzo, Universita` di Pisa
 * Portions Copyright (c) 2000 Akamba Corp.
 * All rights reserved
 *
 * 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.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 * $FreeBSD: src/sys/netinet/ip_dummynet.c,v 1.84 2004/08/25 09:31:30 pjd Exp $
 */

#define DUMMYNET_DEBUG

/*
 * This module implements IP dummynet, a bandwidth limiter/delay emulator
 * Description of the data structures used is in ip_dummynet.h
 * Here you mainly find the following blocks of code:
 *  + variable declarations;
 *  + heap management functions;
 *  + scheduler and dummynet functions;
 *  + configuration and initialization.
 *
 * NOTA BENE: critical sections are protected by the "dummynet lock".
 *
 * Most important Changes:
 *
 * 010124: Fixed WF2Q behaviour
 * 010122: Fixed spl protection.
 * 000601: WF2Q support
 * 000106: large rewrite, use heaps to handle very many pipes.
 * 980513:      initial release
 *
 * include files marked with XXX are probably not needed
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/queue.h>                  /* XXX */
#include <sys/kernel.h>
#include <sys/random.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/route.h>
#include <net/kpi_protocol.h>
#if DUMMYNET
#include <net/kpi_protocol.h>
#endif /* DUMMYNET */
#include <net/nwk_wq.h>
#include <net/pfvar.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_dummynet.h>
#include <netinet/ip_var.h>

#include <netinet/ip6.h>       /* for ip6_input, ip6_output prototypes */
#include <netinet6/ip6_var.h>

/*
 * We keep a private variable for the simulation time, but we could
 * probably use an existing one ("softticks" in sys/kern/kern_timer.c)
 */
static dn_key curr_time = 0;  /* current simulation time */

/* this is for the timer that fires to call dummynet() - we only enable the timer when
 *       there are packets to process, otherwise it's disabled */
static int timer_enabled = 0;

static int dn_hash_size = 64;   /* default hash size */

/* statistics on number of queue searches and search steps */
static int searches, search_steps;
static int pipe_expire = 1;    /* expire queue if empty */
static int dn_max_ratio = 16;  /* max queues/buckets ratio */

static int red_lookup_depth = 256;      /* RED - default lookup table depth */
static int red_avg_pkt_size = 512;      /* RED - default medium packet size */
static int red_max_pkt_size = 1500;     /* RED - default max packet size */

static int serialize = 0;

/*
 * Three heaps contain queues and pipes that the scheduler handles:
 *
 * ready_heap contains all dn_flow_queue related to fixed-rate pipes.
 *
 * wfq_ready_heap contains the pipes associated with WF2Q flows
 *
 * extract_heap contains pipes associated with delay lines.
 *
 */
static struct dn_heap ready_heap, extract_heap, wfq_ready_heap;

static int heap_init(struct dn_heap *h, int size);
static int heap_insert(struct dn_heap *h, dn_key key1, void *p);
static void heap_extract(struct dn_heap *h, void *obj);


static void     transmit_event(struct dn_pipe *pipe, struct mbuf **head,
    struct mbuf **tail);
static void     ready_event(struct dn_flow_queue *q, struct mbuf **head,
    struct mbuf **tail);
static void     ready_event_wfq(struct dn_pipe *p, struct mbuf **head,
    struct mbuf **tail);

/*
 * Packets are retrieved from queues in Dummynet in chains instead of
 * packet-by-packet.  The entire list of packets is first dequeued and
 * sent out by the following function.
 */
static void dummynet_send(struct mbuf *m);

#define HASHSIZE        16
#define HASH(num)       ((((num) >> 8) ^ ((num) >> 4) ^ (num)) & 0x0f)
static struct dn_pipe_head      pipehash[HASHSIZE];     /* all pipes */
static struct dn_flow_set_head  flowsethash[HASHSIZE];  /* all flowsets */

#ifdef SYSCTL_NODE
SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet,
    CTLFLAG_RW | CTLFLAG_LOCKED, 0, "Dummynet");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, hash_size,
    CTLFLAG_RW | CTLFLAG_LOCKED, &dn_hash_size, 0, "Default hash table size");
SYSCTL_QUAD(_net_inet_ip_dummynet, OID_AUTO, curr_time,
    CTLFLAG_RD | CTLFLAG_LOCKED, &curr_time, "Current tick");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, ready_heap,
    CTLFLAG_RD | CTLFLAG_LOCKED, &ready_heap.size, 0, "Size of ready heap");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, extract_heap,
    CTLFLAG_RD | CTLFLAG_LOCKED, &extract_heap.size, 0, "Size of extract heap");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, searches,
    CTLFLAG_RD | CTLFLAG_LOCKED, &searches, 0, "Number of queue searches");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, search_steps,
    CTLFLAG_RD | CTLFLAG_LOCKED, &search_steps, 0, "Number of queue search steps");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, expire,
    CTLFLAG_RW | CTLFLAG_LOCKED, &pipe_expire, 0, "Expire queue if empty");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, max_chain_len,
    CTLFLAG_RW | CTLFLAG_LOCKED, &dn_max_ratio, 0,
    "Max ratio between dynamic queues and buckets");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_lookup_depth,
    CTLFLAG_RD | CTLFLAG_LOCKED, &red_lookup_depth, 0, "Depth of RED lookup table");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_avg_pkt_size,
    CTLFLAG_RD | CTLFLAG_LOCKED, &red_avg_pkt_size, 0, "RED Medium packet size");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_max_pkt_size,
    CTLFLAG_RD | CTLFLAG_LOCKED, &red_max_pkt_size, 0, "RED Max packet size");
#endif

#ifdef DUMMYNET_DEBUG
int     dummynet_debug = 0;
#ifdef SYSCTL_NODE
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, debug, CTLFLAG_RW | CTLFLAG_LOCKED, &dummynet_debug,
    0, "control debugging printfs");
#endif
#define DPRINTF(X)      if (dummynet_debug) printf X
#else
#define DPRINTF(X)
#endif

/* dummynet lock */
static lck_grp_t         *dn_mutex_grp;
static lck_grp_attr_t    *dn_mutex_grp_attr;
static lck_attr_t        *dn_mutex_attr;
decl_lck_mtx_data(static, dn_mutex_data);
static lck_mtx_t         *dn_mutex = &dn_mutex_data;

static int config_pipe(struct dn_pipe *p);
static int ip_dn_ctl(struct sockopt *sopt);

static void dummynet(void *);
static void dummynet_flush(void);
void dummynet_drain(void);
static ip_dn_io_t dummynet_io;

static void cp_flow_set_to_64_user(struct dn_flow_set *set, struct dn_flow_set_64 *fs_bp);
static void cp_queue_to_64_user( struct dn_flow_queue *q, struct dn_flow_queue_64 *qp);
static char *cp_pipe_to_64_user(struct dn_pipe *p, struct dn_pipe_64 *pipe_bp);
static char* dn_copy_set_64(struct dn_flow_set *set, char *bp);
static int cp_pipe_from_user_64( struct sockopt *sopt, struct dn_pipe *p );

static void cp_flow_set_to_32_user(struct dn_flow_set *set, struct dn_flow_set_32 *fs_bp);
static void cp_queue_to_32_user( struct dn_flow_queue *q, struct dn_flow_queue_32 *qp);
static char *cp_pipe_to_32_user(struct dn_pipe *p, struct dn_pipe_32 *pipe_bp);
static char* dn_copy_set_32(struct dn_flow_set *set, char *bp);
static int cp_pipe_from_user_32( struct sockopt *sopt, struct dn_pipe *p );

struct eventhandler_lists_ctxt dummynet_evhdlr_ctxt;

uint32_t
my_random(void)
{
        uint32_t val;
        read_frandom(&val, sizeof(val));
        val &= 0x7FFFFFFF;

        return val;
}

/*
 * Heap management functions.
 *
 * In the heap, first node is element 0. Children of i are 2i+1 and 2i+2.
 * Some macros help finding parent/children so we can optimize them.
 *
 * heap_init() is called to expand the heap when needed.
 * Increment size in blocks of 16 entries.
 * XXX failure to allocate a new element is a pretty bad failure
 * as we basically stall a whole queue forever!!
 * Returns 1 on error, 0 on success
 */
#define HEAP_FATHER(x) ( ( (x) - 1 ) / 2 )
#define HEAP_LEFT(x) ( 2*(x) + 1 )
#define HEAP_IS_LEFT(x) ( (x) & 1 )
#define HEAP_RIGHT(x) ( 2*(x) + 2 )
#define HEAP_SWAP(a, b, buffer) { buffer = a ; a = b ; b = buffer ; }
#define HEAP_INCREMENT  15


int
cp_pipe_from_user_32( struct sockopt *sopt, struct dn_pipe *p )
{
        struct dn_pipe_32 user_pipe_32;
        int error = 0;

        error = sooptcopyin(sopt, &user_pipe_32, sizeof(struct dn_pipe_32), sizeof(struct dn_pipe_32));
        if (!error) {
                p->pipe_nr = user_pipe_32.pipe_nr;
                p->bandwidth = user_pipe_32.bandwidth;
                p->delay = user_pipe_32.delay;
                p->V = user_pipe_32.V;
                p->sum = user_pipe_32.sum;
                p->numbytes = user_pipe_32.numbytes;
                p->sched_time = user_pipe_32.sched_time;
                bcopy( user_pipe_32.if_name, p->if_name, IFNAMSIZ);
                p->ready = user_pipe_32.ready;

                p->fs.fs_nr = user_pipe_32.fs.fs_nr;
                p->fs.flags_fs = user_pipe_32.fs.flags_fs;
                p->fs.parent_nr = user_pipe_32.fs.parent_nr;
                p->fs.weight = user_pipe_32.fs.weight;
                p->fs.qsize = user_pipe_32.fs.qsize;
                p->fs.plr = user_pipe_32.fs.plr;
                p->fs.flow_mask = user_pipe_32.fs.flow_mask;
                p->fs.rq_size = user_pipe_32.fs.rq_size;
                p->fs.rq_elements = user_pipe_32.fs.rq_elements;
                p->fs.last_expired = user_pipe_32.fs.last_expired;
                p->fs.backlogged = user_pipe_32.fs.backlogged;
                p->fs.w_q = user_pipe_32.fs.w_q;
                p->fs.max_th = user_pipe_32.fs.max_th;
                p->fs.min_th = user_pipe_32.fs.min_th;
                p->fs.max_p = user_pipe_32.fs.max_p;
                p->fs.c_1 = user_pipe_32.fs.c_1;
                p->fs.c_2 = user_pipe_32.fs.c_2;
                p->fs.c_3 = user_pipe_32.fs.c_3;
                p->fs.c_4 = user_pipe_32.fs.c_4;
                p->fs.lookup_depth = user_pipe_32.fs.lookup_depth;
                p->fs.lookup_step = user_pipe_32.fs.lookup_step;
                p->fs.lookup_weight = user_pipe_32.fs.lookup_weight;
                p->fs.avg_pkt_size = user_pipe_32.fs.avg_pkt_size;
                p->fs.max_pkt_size = user_pipe_32.fs.max_pkt_size;
        }
        return error;
}


int
cp_pipe_from_user_64( struct sockopt *sopt, struct dn_pipe *p )
{
        struct dn_pipe_64 user_pipe_64;
        int error = 0;

        error = sooptcopyin(sopt, &user_pipe_64, sizeof(struct dn_pipe_64), sizeof(struct dn_pipe_64));
        if (!error) {
                p->pipe_nr = user_pipe_64.pipe_nr;
                p->bandwidth = user_pipe_64.bandwidth;
                p->delay = user_pipe_64.delay;
                p->V = user_pipe_64.V;
                p->sum = user_pipe_64.sum;
                p->numbytes = user_pipe_64.numbytes;
                p->sched_time = user_pipe_64.sched_time;
                bcopy( user_pipe_64.if_name, p->if_name, IFNAMSIZ);
                p->ready = user_pipe_64.ready;

                p->fs.fs_nr = user_pipe_64.fs.fs_nr;
                p->fs.flags_fs = user_pipe_64.fs.flags_fs;
                p->fs.parent_nr = user_pipe_64.fs.parent_nr;
                p->fs.weight = user_pipe_64.fs.weight;
                p->fs.qsize = user_pipe_64.fs.qsize;
                p->fs.plr = user_pipe_64.fs.plr;
                p->fs.flow_mask = user_pipe_64.fs.flow_mask;
                p->fs.rq_size = user_pipe_64.fs.rq_size;
                p->fs.rq_elements = user_pipe_64.fs.rq_elements;
                p->fs.last_expired = user_pipe_64.fs.last_expired;
                p->fs.backlogged = user_pipe_64.fs.backlogged;
                p->fs.w_q = user_pipe_64.fs.w_q;
                p->fs.max_th = user_pipe_64.fs.max_th;
                p->fs.min_th = user_pipe_64.fs.min_th;
                p->fs.max_p = user_pipe_64.fs.max_p;
                p->fs.c_1 = user_pipe_64.fs.c_1;
                p->fs.c_2 = user_pipe_64.fs.c_2;
                p->fs.c_3 = user_pipe_64.fs.c_3;
                p->fs.c_4 = user_pipe_64.fs.c_4;
                p->fs.lookup_depth = user_pipe_64.fs.lookup_depth;
                p->fs.lookup_step = user_pipe_64.fs.lookup_step;
                p->fs.lookup_weight = user_pipe_64.fs.lookup_weight;
                p->fs.avg_pkt_size = user_pipe_64.fs.avg_pkt_size;
                p->fs.max_pkt_size = user_pipe_64.fs.max_pkt_size;
        }
        return error;
}

static void
cp_flow_set_to_32_user(struct dn_flow_set *set, struct dn_flow_set_32 *fs_bp)
{
        fs_bp->fs_nr = set->fs_nr;
        fs_bp->flags_fs = set->flags_fs;
        fs_bp->parent_nr = set->parent_nr;
        fs_bp->weight = set->weight;
        fs_bp->qsize = set->qsize;
        fs_bp->plr = set->plr;
        fs_bp->flow_mask = set->flow_mask;
        fs_bp->rq_size = set->rq_size;
        fs_bp->rq_elements = set->rq_elements;
        fs_bp->last_expired = set->last_expired;
        fs_bp->backlogged = set->backlogged;
        fs_bp->w_q = set->w_q;
        fs_bp->max_th = set->max_th;
        fs_bp->min_th = set->min_th;
        fs_bp->max_p = set->max_p;
        fs_bp->c_1 = set->c_1;
        fs_bp->c_2 = set->c_2;
        fs_bp->c_3 = set->c_3;
        fs_bp->c_4 = set->c_4;
        fs_bp->w_q_lookup = CAST_DOWN_EXPLICIT(user32_addr_t, set->w_q_lookup);
        fs_bp->lookup_depth = set->lookup_depth;
        fs_bp->lookup_step = set->lookup_step;
        fs_bp->lookup_weight = set->lookup_weight;
        fs_bp->avg_pkt_size = set->avg_pkt_size;
        fs_bp->max_pkt_size = set->max_pkt_size;
}

static void
cp_flow_set_to_64_user(struct dn_flow_set *set, struct dn_flow_set_64 *fs_bp)
{
        fs_bp->fs_nr = set->fs_nr;
        fs_bp->flags_fs = set->flags_fs;
        fs_bp->parent_nr = set->parent_nr;
        fs_bp->weight = set->weight;
        fs_bp->qsize = set->qsize;
        fs_bp->plr = set->plr;
        fs_bp->flow_mask = set->flow_mask;
        fs_bp->rq_size = set->rq_size;
        fs_bp->rq_elements = set->rq_elements;
        fs_bp->last_expired = set->last_expired;
        fs_bp->backlogged = set->backlogged;
        fs_bp->w_q = set->w_q;
        fs_bp->max_th = set->max_th;
        fs_bp->min_th = set->min_th;
        fs_bp->max_p = set->max_p;
        fs_bp->c_1 = set->c_1;
        fs_bp->c_2 = set->c_2;
        fs_bp->c_3 = set->c_3;
        fs_bp->c_4 = set->c_4;
        fs_bp->w_q_lookup = CAST_DOWN(user64_addr_t, set->w_q_lookup);
        fs_bp->lookup_depth = set->lookup_depth;
        fs_bp->lookup_step = set->lookup_step;
        fs_bp->lookup_weight = set->lookup_weight;
        fs_bp->avg_pkt_size = set->avg_pkt_size;
        fs_bp->max_pkt_size = set->max_pkt_size;
}

static
void
cp_queue_to_32_user( struct dn_flow_queue *q, struct dn_flow_queue_32 *qp)
{
        qp->id = q->id;
        qp->len = q->len;
        qp->len_bytes = q->len_bytes;
        qp->numbytes = q->numbytes;
        qp->tot_pkts = q->tot_pkts;
        qp->tot_bytes = q->tot_bytes;
        qp->drops = q->drops;
        qp->hash_slot = q->hash_slot;
        qp->avg = q->avg;
        qp->count = q->count;
        qp->random = q->random;
        qp->q_time = q->q_time;
        qp->heap_pos = q->heap_pos;
        qp->sched_time = q->sched_time;
        qp->S = q->S;
        qp->F = q->F;
}

static
void
cp_queue_to_64_user( struct dn_flow_queue *q, struct dn_flow_queue_64 *qp)
{
        qp->id = q->id;
        qp->len = q->len;
        qp->len_bytes = q->len_bytes;
        qp->numbytes = q->numbytes;
        qp->tot_pkts = q->tot_pkts;
        qp->tot_bytes = q->tot_bytes;
        qp->drops = q->drops;
        qp->hash_slot = q->hash_slot;
        qp->avg = q->avg;
        qp->count = q->count;
        qp->random = q->random;
        qp->q_time = q->q_time;
        qp->heap_pos = q->heap_pos;
        qp->sched_time = q->sched_time;
        qp->S = q->S;
        qp->F = q->F;
}

static
char *
cp_pipe_to_32_user(struct dn_pipe *p, struct dn_pipe_32 *pipe_bp)
{
        char    *bp;

        pipe_bp->pipe_nr = p->pipe_nr;
        pipe_bp->bandwidth = p->bandwidth;
        pipe_bp->delay = p->delay;
        bcopy( &(p->scheduler_heap), &(pipe_bp->scheduler_heap), sizeof(struct dn_heap_32));
        pipe_bp->scheduler_heap.p = CAST_DOWN_EXPLICIT(user32_addr_t, pipe_bp->scheduler_heap.p);
        bcopy( &(p->not_eligible_heap), &(pipe_bp->not_eligible_heap), sizeof(struct dn_heap_32));
        pipe_bp->not_eligible_heap.p = CAST_DOWN_EXPLICIT(user32_addr_t, pipe_bp->not_eligible_heap.p);
        bcopy( &(p->idle_heap), &(pipe_bp->idle_heap), sizeof(struct dn_heap_32));
        pipe_bp->idle_heap.p = CAST_DOWN_EXPLICIT(user32_addr_t, pipe_bp->idle_heap.p);
        pipe_bp->V = p->V;
        pipe_bp->sum = p->sum;
        pipe_bp->numbytes = p->numbytes;
        pipe_bp->sched_time = p->sched_time;
        bcopy( p->if_name, pipe_bp->if_name, IFNAMSIZ);
        pipe_bp->ifp = CAST_DOWN_EXPLICIT(user32_addr_t, p->ifp);
        pipe_bp->ready = p->ready;

        cp_flow_set_to_32_user( &(p->fs), &(pipe_bp->fs));

        pipe_bp->delay = (pipe_bp->delay * 1000) / (hz * 10);
        /*
         * XXX the following is a hack based on ->next being the
         * first field in dn_pipe and dn_flow_set. The correct
         * solution would be to move the dn_flow_set to the beginning
         * of struct dn_pipe.
         */
        pipe_bp->next = CAST_DOWN_EXPLICIT( user32_addr_t, DN_IS_PIPE );
        /* clean pointers */
        pipe_bp->head = pipe_bp->tail = (user32_addr_t) 0;
        pipe_bp->fs.next = (user32_addr_t)0;
        pipe_bp->fs.pipe = (user32_addr_t)0;
        pipe_bp->fs.rq = (user32_addr_t)0;
        bp = ((char *)pipe_bp) + sizeof(struct dn_pipe_32);
        return dn_copy_set_32( &(p->fs), bp);
}

static
char *
cp_pipe_to_64_user(struct dn_pipe *p, struct dn_pipe_64 *pipe_bp)
{
        char    *bp;

        pipe_bp->pipe_nr = p->pipe_nr;
        pipe_bp->bandwidth = p->bandwidth;
        pipe_bp->delay = p->delay;
        bcopy( &(p->scheduler_heap), &(pipe_bp->scheduler_heap), sizeof(struct dn_heap_64));
        pipe_bp->scheduler_heap.p = CAST_DOWN(user64_addr_t, pipe_bp->scheduler_heap.p);
        bcopy( &(p->not_eligible_heap), &(pipe_bp->not_eligible_heap), sizeof(struct dn_heap_64));
        pipe_bp->not_eligible_heap.p = CAST_DOWN(user64_addr_t, pipe_bp->not_eligible_heap.p);
        bcopy( &(p->idle_heap), &(pipe_bp->idle_heap), sizeof(struct dn_heap_64));
        pipe_bp->idle_heap.p = CAST_DOWN(user64_addr_t, pipe_bp->idle_heap.p);
        pipe_bp->V = p->V;
        pipe_bp->sum = p->sum;
        pipe_bp->numbytes = p->numbytes;
        pipe_bp->sched_time = p->sched_time;
        bcopy( p->if_name, pipe_bp->if_name, IFNAMSIZ);
        pipe_bp->ifp = CAST_DOWN(user64_addr_t, p->ifp);
        pipe_bp->ready = p->ready;

        cp_flow_set_to_64_user( &(p->fs), &(pipe_bp->fs));

        pipe_bp->delay = (pipe_bp->delay * 1000) / (hz * 10);
        /*
         * XXX the following is a hack based on ->next being the
         * first field in dn_pipe and dn_flow_set. The correct
         * solution would be to move the dn_flow_set to the beginning
         * of struct dn_pipe.
         */
        pipe_bp->next = CAST_DOWN( user64_addr_t, DN_IS_PIPE );
        /* clean pointers */
        pipe_bp->head = pipe_bp->tail = USER_ADDR_NULL;
        pipe_bp->fs.next = USER_ADDR_NULL;
        pipe_bp->fs.pipe = USER_ADDR_NULL;
        pipe_bp->fs.rq = USER_ADDR_NULL;
        bp = ((char *)pipe_bp) + sizeof(struct dn_pipe_64);
        return dn_copy_set_64( &(p->fs), bp);
}

static int
heap_init(struct dn_heap *h, int new_size)
{
        struct dn_heap_entry *p;

        if (h->size >= new_size) {
                printf("dummynet: heap_init, Bogus call, have %d want %d\n",
                    h->size, new_size);
                return 0;
        }
        new_size = (new_size + HEAP_INCREMENT) & ~HEAP_INCREMENT;
        p = _MALLOC(new_size * sizeof(*p), M_DUMMYNET, M_DONTWAIT );
        if (p == NULL) {
                printf("dummynet: heap_init, resize %d failed\n", new_size );
                return 1; /* error */
        }
        if (h->size > 0) {
                bcopy(h->p, p, h->size * sizeof(*p));
                FREE(h->p, M_DUMMYNET);
        }
        h->p = p;
        h->size = new_size;
        return 0;
}

/*
 * Insert element in heap. Normally, p != NULL, we insert p in
 * a new position and bubble up. If p == NULL, then the element is
 * already in place, and key is the position where to start the
 * bubble-up.
 * Returns 1 on failure (cannot allocate new heap entry)
 *
 * If offset > 0 the position (index, int) of the element in the heap is
 * also stored in the element itself at the given offset in bytes.
 */
#define SET_OFFSET(heap, node) \
    if (heap->offset > 0) \
            *((int *)((char *)(heap->p[node].object) + heap->offset)) = node ;
/*
 * RESET_OFFSET is used for sanity checks. It sets offset to an invalid value.
 */
#define RESET_OFFSET(heap, node) \
    if (heap->offset > 0) \
            *((int *)((char *)(heap->p[node].object) + heap->offset)) = -1 ;
static int
heap_insert(struct dn_heap *h, dn_key key1, void *p)
{
        int son = h->elements;

        if (p == NULL) { /* data already there, set starting point */
                son = key1;
        } else {        /* insert new element at the end, possibly resize */
                son = h->elements;
                if (son == h->size) { /* need resize... */
                        if (heap_init(h, h->elements + 1)) {
                                return 1; /* failure... */
                        }
                }
                h->p[son].object = p;
                h->p[son].key = key1;
                h->elements++;
        }
        while (son > 0) {                       /* bubble up */
                int father = HEAP_FATHER(son);
                struct dn_heap_entry tmp;

                if (DN_KEY_LT( h->p[father].key, h->p[son].key )) {
                        break; /* found right position */
                }
                /* son smaller than father, swap and repeat */
                HEAP_SWAP(h->p[son], h->p[father], tmp);
                SET_OFFSET(h, son);
                son = father;
        }
        SET_OFFSET(h, son);
        return 0;
}

/*
 * remove top element from heap, or obj if obj != NULL
 */
static void
heap_extract(struct dn_heap *h, void *obj)
{
        int child, father, maxelt = h->elements - 1;

        if (maxelt < 0) {
                printf("dummynet: warning, extract from empty heap 0x%llx\n",
                    (uint64_t)VM_KERNEL_ADDRPERM(h));
                return;
        }
        father = 0; /* default: move up smallest child */
        if (obj != NULL) { /* extract specific element, index is at offset */
                if (h->offset <= 0) {
                        panic("dummynet: heap_extract from middle not supported on this heap!!!\n");
                }
                father = *((int *)((char *)obj + h->offset));
                if (father < 0 || father >= h->elements) {
                        printf("dummynet: heap_extract, father %d out of bound 0..%d\n",
                            father, h->elements);
                        panic("dummynet: heap_extract");
                }
        }
        RESET_OFFSET(h, father);
        child = HEAP_LEFT(father);      /* left child */
        while (child <= maxelt) {       /* valid entry */
                if (child != maxelt && DN_KEY_LT(h->p[child + 1].key, h->p[child].key)) {
                        child = child + 1; /* take right child, otherwise left */
                }
                h->p[father] = h->p[child];
                SET_OFFSET(h, father);
                father = child;
                child = HEAP_LEFT(child); /* left child for next loop */
        }
        h->elements--;
        if (father != maxelt) {
                /*
                 * Fill hole with last entry and bubble up, reusing the insert code
                 */
                h->p[father] = h->p[maxelt];
                heap_insert(h, father, NULL); /* this one cannot fail */
        }
}

/*
 * heapify() will reorganize data inside an array to maintain the
 * heap property. It is needed when we delete a bunch of entries.
 */
static void
heapify(struct dn_heap *h)
{
        int i;

        for (i = 0; i < h->elements; i++) {
                heap_insert(h, i, NULL);
        }
}

/*
 * cleanup the heap and free data structure
 */
static void
heap_free(struct dn_heap *h)
{
        if (h->size > 0) {
                FREE(h->p, M_DUMMYNET);
        }
        bzero(h, sizeof(*h));
}

/*
 * --- end of heap management functions ---
 */

/*
 * Return the mbuf tag holding the dummynet state.  As an optimization
 * this is assumed to be the first tag on the list.  If this turns out
 * wrong we'll need to search the list.
 */
static struct dn_pkt_tag *
dn_tag_get(struct mbuf *m)
{
        struct m_tag *mtag = m_tag_first(m);

        if (!(mtag != NULL &&
            mtag->m_tag_id == KERNEL_MODULE_TAG_ID &&
            mtag->m_tag_type == KERNEL_TAG_TYPE_DUMMYNET)) {
                panic("packet on dummynet queue w/o dummynet tag: 0x%llx",
                    (uint64_t)VM_KERNEL_ADDRPERM(m));
        }

        return (struct dn_pkt_tag *)(mtag + 1);
}

/*
 * Scheduler functions:
 *
 * transmit_event() is called when the delay-line needs to enter
 * the scheduler, either because of existing pkts getting ready,
 * or new packets entering the queue. The event handled is the delivery
 * time of the packet.
 *
 * ready_event() does something similar with fixed-rate queues, and the
 * event handled is the finish time of the head pkt.
 *
 * wfq_ready_event() does something similar with WF2Q queues, and the
 * event handled is the start time of the head pkt.
 *
 * In all cases, we make sure that the data structures are consistent
 * before passing pkts out, because this might trigger recursive
 * invocations of the procedures.
 */
static void
transmit_event(struct dn_pipe *pipe, struct mbuf **head, struct mbuf **tail)
{
        struct mbuf *m;
        struct dn_pkt_tag *pkt = NULL;
        u_int64_t schedule_time;

        LCK_MTX_ASSERT(dn_mutex, LCK_MTX_ASSERT_OWNED);
        ASSERT(serialize >= 0);
        if (serialize == 0) {
                while ((m = pipe->head) != NULL) {
                        pkt = dn_tag_get(m);
                        if (!DN_KEY_LEQ(pkt->dn_output_time, curr_time)) {
                                break;
                        }

                        pipe->head = m->m_nextpkt;
                        if (*tail != NULL) {
                                (*tail)->m_nextpkt = m;
                        } else {
                                *head = m;
                        }
                        *tail = m;
                }

                if (*tail != NULL) {
                        (*tail)->m_nextpkt = NULL;
                }
        }

        schedule_time = pkt == NULL || DN_KEY_LEQ(pkt->dn_output_time, curr_time) ?
            curr_time + 1 : pkt->dn_output_time;

        /* if there are leftover packets, put the pipe into the heap for next ready event */
        if ((m = pipe->head) != NULL) {
                pkt = dn_tag_get(m);
                /* XXX should check errors on heap_insert, by draining the
                 * whole pipe p and hoping in the future we are more successful
                 */
                heap_insert(&extract_heap, schedule_time, pipe);
        }
}

/*
 * the following macro computes how many ticks we have to wait
 * before being able to transmit a packet. The credit is taken from
 * either a pipe (WF2Q) or a flow_queue (per-flow queueing)
 */

/* hz is 100, which gives a granularity of 10ms in the old timer.
 * The timer has been changed to fire every 1ms, so the use of
 * hz has been modified here. All instances of hz have been left
 * in place but adjusted by a factor of 10 so that hz is functionally
 * equal to 1000.
 */
#define SET_TICKS(_m, q, p)     \
    ((_m)->m_pkthdr.len*8*(hz*10) - (q)->numbytes + p->bandwidth - 1 ) / \
            p->bandwidth ;

/*
 * extract pkt from queue, compute output time (could be now)
 * and put into delay line (p_queue)
 */
static void
move_pkt(struct mbuf *pkt, struct dn_flow_queue *q,
    struct dn_pipe *p, int len)
{
        struct dn_pkt_tag *dt = dn_tag_get(pkt);

        q->head = pkt->m_nextpkt;
        q->len--;
        q->len_bytes -= len;

        dt->dn_output_time = curr_time + p->delay;

        if (p->head == NULL) {
                p->head = pkt;
        } else {
                p->tail->m_nextpkt = pkt;
        }
        p->tail = pkt;
        p->tail->m_nextpkt = NULL;
}

/*
 * ready_event() is invoked every time the queue must enter the
 * scheduler, either because the first packet arrives, or because
 * a previously scheduled event fired.
 * On invokation, drain as many pkts as possible (could be 0) and then
 * if there are leftover packets reinsert the pkt in the scheduler.
 */
static void
ready_event(struct dn_flow_queue *q, struct mbuf **head, struct mbuf **tail)
{
        struct mbuf *pkt;
        struct dn_pipe *p = q->fs->pipe;
        int p_was_empty;

        LCK_MTX_ASSERT(dn_mutex, LCK_MTX_ASSERT_OWNED);

        if (p == NULL) {
                printf("dummynet: ready_event pipe is gone\n");
                return;
        }
        p_was_empty = (p->head == NULL);

        /*
         * schedule fixed-rate queues linked to this pipe:
         * Account for the bw accumulated since last scheduling, then
         * drain as many pkts as allowed by q->numbytes and move to
         * the delay line (in p) computing output time.
         * bandwidth==0 (no limit) means we can drain the whole queue,
         * setting len_scaled = 0 does the job.
         */
        q->numbytes += (curr_time - q->sched_time) * p->bandwidth;
        while ((pkt = q->head) != NULL) {
                int len = pkt->m_pkthdr.len;
                int len_scaled = p->bandwidth ? len * 8 * (hz * 10) : 0;
                if (len_scaled > q->numbytes) {
                        break;
                }
                q->numbytes -= len_scaled;
                move_pkt(pkt, q, p, len);
        }
        /*
         * If we have more packets queued, schedule next ready event
         * (can only occur when bandwidth != 0, otherwise we would have
         * flushed the whole queue in the previous loop).
         * To this purpose we record the current time and compute how many
         * ticks to go for the finish time of the packet.
         */
        if ((pkt = q->head) != NULL) { /* this implies bandwidth != 0 */
                dn_key t = SET_TICKS(pkt, q, p); /* ticks i have to wait */
                q->sched_time = curr_time;
                heap_insert(&ready_heap, curr_time + t, (void *)q );
                /* XXX should check errors on heap_insert, and drain the whole
                 * queue on error hoping next time we are luckier.
                 */
        } else { /* RED needs to know when the queue becomes empty */
                q->q_time = curr_time;
                q->numbytes = 0;
        }
        /*
         * If the delay line was empty call transmit_event(p) now.
         * Otherwise, the scheduler will take care of it.
         */
        if (p_was_empty) {
                transmit_event(p, head, tail);
        }
}

/*
 * Called when we can transmit packets on WF2Q queues. Take pkts out of
 * the queues at their start time, and enqueue into the delay line.
 * Packets are drained until p->numbytes < 0. As long as
 * len_scaled >= p->numbytes, the packet goes into the delay line
 * with a deadline p->delay. For the last packet, if p->numbytes<0,
 * there is an additional delay.
 */
static void
ready_event_wfq(struct dn_pipe *p, struct mbuf **head, struct mbuf **tail)
{
        int p_was_empty = (p->head == NULL);
        struct dn_heap *sch = &(p->scheduler_heap);
        struct dn_heap *neh = &(p->not_eligible_heap);
        int64_t p_numbytes = p->numbytes;

        LCK_MTX_ASSERT(dn_mutex, LCK_MTX_ASSERT_OWNED);

        if (p->if_name[0] == 0) { /* tx clock is simulated */
                p_numbytes += (curr_time - p->sched_time) * p->bandwidth;
        } else { /* tx clock is for real, the ifq must be empty or this is a NOP */
                if (p->ifp && !IFCQ_IS_EMPTY(&p->ifp->if_snd)) {
                        return;
                } else {
                        DPRINTF(("dummynet: pipe %d ready from %s --\n",
                            p->pipe_nr, p->if_name));
                }
        }

        /*
         * While we have backlogged traffic AND credit, we need to do
         * something on the queue.
         */
        while (p_numbytes >= 0 && (sch->elements > 0 || neh->elements > 0)) {
                if (sch->elements > 0) { /* have some eligible pkts to send out */
                        struct dn_flow_queue *q = sch->p[0].object;
                        struct mbuf *pkt = q->head;
                        struct dn_flow_set *fs = q->fs;
                        u_int64_t len = pkt->m_pkthdr.len;
                        int len_scaled = p->bandwidth ? len * 8 * (hz * 10) : 0;

                        heap_extract(sch, NULL); /* remove queue from heap */
                        p_numbytes -= len_scaled;
                        move_pkt(pkt, q, p, len);

                        p->V += (len << MY_M) / p->sum; /* update V */
                        q->S = q->F; /* update start time */
                        if (q->len == 0) { /* Flow not backlogged any more */
                                fs->backlogged--;
                                heap_insert(&(p->idle_heap), q->F, q);
                        } else { /* still backlogged */
                                /*
                                 * update F and position in backlogged queue, then
                                 * put flow in not_eligible_heap (we will fix this later).
                                 */
                                len = (q->head)->m_pkthdr.len;
                                q->F += (len << MY_M) / (u_int64_t) fs->weight;
                                if (DN_KEY_LEQ(q->S, p->V)) {
                                        heap_insert(neh, q->S, q);
                                } else {
                                        heap_insert(sch, q->F, q);
                                }
                        }
                }
                /*
                 * now compute V = max(V, min(S_i)). Remember that all elements in sch
                 * have by definition S_i <= V so if sch is not empty, V is surely
                 * the max and we must not update it. Conversely, if sch is empty
                 * we only need to look at neh.
                 */
                if (sch->elements == 0 && neh->elements > 0) {
                        p->V = MAX64( p->V, neh->p[0].key );
                }
                /* move from neh to sch any packets that have become eligible */
                while (neh->elements > 0 && DN_KEY_LEQ(neh->p[0].key, p->V)) {
                        struct dn_flow_queue *q = neh->p[0].object;
                        heap_extract(neh, NULL);
                        heap_insert(sch, q->F, q);
                }

                if (p->if_name[0] != '\0') {/* tx clock is from a real thing */
                        p_numbytes = -1; /* mark not ready for I/O */
                        break;
                }
        }
        if (sch->elements == 0 && neh->elements == 0 && p_numbytes >= 0
            && p->idle_heap.elements > 0) {
                /*
                 * no traffic and no events scheduled. We can get rid of idle-heap.
                 */
                int i;

                for (i = 0; i < p->idle_heap.elements; i++) {
                        struct dn_flow_queue *q = p->idle_heap.p[i].object;

                        q->F = 0;
                        q->S = q->F + 1;
                }
                p->sum = 0;
                p->V = 0;
                p->idle_heap.elements = 0;
        }
        /*
         * If we are getting clocks from dummynet (not a real interface) and
         * If we are under credit, schedule the next ready event.
         * Also fix the delivery time of the last packet.
         */
        if (p->if_name[0] == 0 && p_numbytes < 0) { /* this implies bandwidth >0 */
                dn_key t = 0; /* number of ticks i have to wait */

                if (p->bandwidth > 0) {
                        t = (p->bandwidth - 1 - p_numbytes) / p->bandwidth;
                }
                dn_tag_get(p->tail)->dn_output_time += t;
                p->sched_time = curr_time;
                heap_insert(&wfq_ready_heap, curr_time + t, (void *)p);
                /* XXX should check errors on heap_insert, and drain the whole
                 * queue on error hoping next time we are luckier.
                 */
        }

        /* Fit (adjust if necessary) 64bit result into 32bit variable. */
        if (p_numbytes > INT_MAX) {
                p->numbytes = INT_MAX;
        } else if (p_numbytes < INT_MIN) {
                p->numbytes = INT_MIN;
        } else {
                p->numbytes = p_numbytes;
        }

        /*
         * If the delay line was empty call transmit_event(p) now.
         * Otherwise, the scheduler will take care of it.
         */
        if (p_was_empty) {
                transmit_event(p, head, tail);
        }
}

/*
 * This is called every 1ms. It is used to
 * increment the current tick counter and schedule expired events.
 */
static void
dummynet(__unused void * unused)
{
        void *p; /* generic parameter to handler */
        struct dn_heap *h;
        struct dn_heap *heaps[3];
        struct mbuf *head = NULL, *tail = NULL;
        int i;
        struct dn_pipe *pe;
        struct timespec ts;
        struct timeval      tv;

        heaps[0] = &ready_heap;         /* fixed-rate queues */
        heaps[1] = &wfq_ready_heap;     /* wfq queues */
        heaps[2] = &extract_heap;       /* delay line */

        lck_mtx_lock(dn_mutex);

        /* make all time measurements in milliseconds (ms) -
         * here we convert secs and usecs to msecs (just divide the
         * usecs and take the closest whole number).
         */
        microuptime(&tv);
        curr_time = (tv.tv_sec * 1000) + (tv.tv_usec / 1000);

        for (i = 0; i < 3; i++) {
                h = heaps[i];
                while (h->elements > 0 && DN_KEY_LEQ(h->p[0].key, curr_time)) {
                        if (h->p[0].key > curr_time) {
                                printf("dummynet: warning, heap %d is %d ticks late\n",
                                    i, (int)(curr_time - h->p[0].key));
                        }
                        p = h->p[0].object; /* store a copy before heap_extract */
                        heap_extract(h, NULL); /* need to extract before processing */
                        if (i == 0) {
                                ready_event(p, &head, &tail);
                        } else if (i == 1) {
                                struct dn_pipe *pipe = p;
                                if (pipe->if_name[0] != '\0') {
                                        printf("dummynet: bad ready_event_wfq for pipe %s\n",
                                            pipe->if_name);
                                } else {
                                        ready_event_wfq(p, &head, &tail);
                                }
                        } else {
                                transmit_event(p, &head, &tail);
                        }
                }
        }
        /* sweep pipes trying to expire idle flow_queues */
        for (i = 0; i < HASHSIZE; i++) {
                SLIST_FOREACH(pe, &pipehash[i], next) {
                        if (pe->idle_heap.elements > 0 &&
                            DN_KEY_LT(pe->idle_heap.p[0].key, pe->V)) {
                                struct dn_flow_queue *q = pe->idle_heap.p[0].object;

                                heap_extract(&(pe->idle_heap), NULL);
                                q->S = q->F + 1; /* mark timestamp as invalid */
                                pe->sum -= q->fs->weight;
                        }
                }
        }

        /* check the heaps to see if there's still stuff in there, and
         * only set the timer if there are packets to process
         */
        timer_enabled = 0;
        for (i = 0; i < 3; i++) {
                h = heaps[i];
                if (h->elements > 0) { // set the timer
                        ts.tv_sec = 0;
                        ts.tv_nsec = 1 * 1000000;       // 1ms
                        timer_enabled = 1;
                        bsd_timeout(dummynet, NULL, &ts);
                        break;
                }
        }

        if (head != NULL) {
                serialize++;
        }

        lck_mtx_unlock(dn_mutex);

        /* Send out the de-queued list of ready-to-send packets */
        if (head != NULL) {
                dummynet_send(head);
                lck_mtx_lock(dn_mutex);
                serialize--;
                lck_mtx_unlock(dn_mutex);
        }
}


static void
dummynet_send(struct mbuf *m)
{
        struct dn_pkt_tag *pkt;
        struct mbuf *n;

        for (; m != NULL; m = n) {
                n = m->m_nextpkt;
                m->m_nextpkt = NULL;
                pkt = dn_tag_get(m);

                DPRINTF(("dummynet_send m: 0x%llx dn_dir: %d dn_flags: 0x%x\n",
                    (uint64_t)VM_KERNEL_ADDRPERM(m), pkt->dn_dir,
                    pkt->dn_flags));

                switch (pkt->dn_dir) {
                case DN_TO_IP_OUT: {
                        struct route tmp_rt;

                        /* route is already in the packet's dn_ro */
                        bzero(&tmp_rt, sizeof(tmp_rt));

                        /* Force IP_RAWOUTPUT as the IP header is fully formed */
                        pkt->dn_flags |= IP_RAWOUTPUT | IP_FORWARDING;
                        (void)ip_output(m, NULL, &tmp_rt, pkt->dn_flags, NULL, NULL);
                        ROUTE_RELEASE(&tmp_rt);
                        break;
                }
                case DN_TO_IP_IN:
                        proto_inject(PF_INET, m);
                        break;
                case DN_TO_IP6_OUT: {
                        /* routes already in the packet's dn_{ro6,pmtu} */
                        ip6_output(m, NULL, NULL, IPV6_FORWARDING, NULL, NULL, NULL);
                        break;
                }
                case DN_TO_IP6_IN:
                        proto_inject(PF_INET6, m);
                        break;
                default:
                        printf("dummynet: bad switch %d!\n", pkt->dn_dir);
                        m_freem(m);
                        break;
                }
        }
}

/*
 * Unconditionally expire empty queues in case of shortage.
 * Returns the number of queues freed.
 */
static int
expire_queues(struct dn_flow_set *fs)
{
        struct dn_flow_queue *q, *prev;
        int i, initial_elements = fs->rq_elements;
        struct timeval timenow;

        /* reviewed for getmicrotime usage */
        getmicrotime(&timenow);

        if (fs->last_expired == timenow.tv_sec) {
                return 0;
        }
        fs->last_expired = timenow.tv_sec;
        for (i = 0; i <= fs->rq_size; i++) { /* last one is overflow */
                for (prev = NULL, q = fs->rq[i]; q != NULL;) {
                        if (q->head != NULL || q->S != q->F + 1) {
                                prev = q;
                                q = q->next;
                        } else { /* entry is idle, expire it */
                                struct dn_flow_queue *old_q = q;

                                if (prev != NULL) {
                                        prev->next = q = q->next;
                                } else {
                                        fs->rq[i] = q = q->next;
                                }
                                fs->rq_elements--;
                                FREE(old_q, M_DUMMYNET);
                        }
                }
        }
        return initial_elements - fs->rq_elements;
}

/*
 * If room, create a new queue and put at head of slot i;
 * otherwise, create or use the default queue.
 */
static struct dn_flow_queue *
create_queue(struct dn_flow_set *fs, int i)
{
        struct dn_flow_queue *q;

        if (fs->rq_elements > fs->rq_size * dn_max_ratio &&
            expire_queues(fs) == 0) {
                /*
                 * No way to get room, use or create overflow queue.
                 */
                i = fs->rq_size;
                if (fs->rq[i] != NULL) {
                        return fs->rq[i];
                }
        }
        q = _MALLOC(sizeof(*q), M_DUMMYNET, M_DONTWAIT | M_ZERO);
        if (q == NULL) {
                printf("dummynet: sorry, cannot allocate queue for new flow\n");
                return NULL;
        }
        q->fs = fs;
        q->hash_slot = i;
        q->next = fs->rq[i];
        q->S = q->F + 1; /* hack - mark timestamp as invalid */
        fs->rq[i] = q;
        fs->rq_elements++;
        return q;
}

/*
 * Given a flow_set and a pkt in last_pkt, find a matching queue
 * after appropriate masking. The queue is moved to front
 * so that further searches take less time.
 */
static struct dn_flow_queue *
find_queue(struct dn_flow_set *fs, struct ip_flow_id *id)
{
        int i = 0; /* we need i and q for new allocations */
        struct dn_flow_queue *q, *prev;
        int is_v6 = IS_IP6_FLOW_ID(id);

        if (!(fs->flags_fs & DN_HAVE_FLOW_MASK)) {
                q = fs->rq[0];
        } else {
                /* first, do the masking, then hash */
                id->dst_port &= fs->flow_mask.dst_port;
                id->src_port &= fs->flow_mask.src_port;
                id->proto &= fs->flow_mask.proto;
                id->flags = 0; /* we don't care about this one */
                if (is_v6) {
                        APPLY_MASK(&id->dst_ip6, &fs->flow_mask.dst_ip6);
                        APPLY_MASK(&id->src_ip6, &fs->flow_mask.src_ip6);
                        id->flow_id6 &= fs->flow_mask.flow_id6;

                        i = ((id->dst_ip6.__u6_addr.__u6_addr32[0]) & 0xffff) ^
                            ((id->dst_ip6.__u6_addr.__u6_addr32[1]) & 0xffff) ^
                            ((id->dst_ip6.__u6_addr.__u6_addr32[2]) & 0xffff) ^
                            ((id->dst_ip6.__u6_addr.__u6_addr32[3]) & 0xffff) ^

                            ((id->dst_ip6.__u6_addr.__u6_addr32[0] >> 15) & 0xffff) ^
                            ((id->dst_ip6.__u6_addr.__u6_addr32[1] >> 15) & 0xffff) ^
                            ((id->dst_ip6.__u6_addr.__u6_addr32[2] >> 15) & 0xffff) ^
                            ((id->dst_ip6.__u6_addr.__u6_addr32[3] >> 15) & 0xffff) ^

                            ((id->src_ip6.__u6_addr.__u6_addr32[0] << 1) & 0xfffff) ^
                            ((id->src_ip6.__u6_addr.__u6_addr32[1] << 1) & 0xfffff) ^
                            ((id->src_ip6.__u6_addr.__u6_addr32[2] << 1) & 0xfffff) ^
                            ((id->src_ip6.__u6_addr.__u6_addr32[3] << 1) & 0xfffff) ^

                            ((id->src_ip6.__u6_addr.__u6_addr32[0] >> 16) & 0xffff) ^
                            ((id->src_ip6.__u6_addr.__u6_addr32[1] >> 16) & 0xffff) ^
                            ((id->src_ip6.__u6_addr.__u6_addr32[2] >> 16) & 0xffff) ^
                            ((id->src_ip6.__u6_addr.__u6_addr32[3] >> 16) & 0xffff) ^

                            (id->dst_port << 1) ^ (id->src_port) ^
                            (id->proto) ^
                            (id->flow_id6);
                } else {
                        id->dst_ip &= fs->flow_mask.dst_ip;
                        id->src_ip &= fs->flow_mask.src_ip;

                        i = ((id->dst_ip) & 0xffff) ^
                            ((id->dst_ip >> 15) & 0xffff) ^
                            ((id->src_ip << 1) & 0xffff) ^
                            ((id->src_ip >> 16) & 0xffff) ^
                            (id->dst_port << 1) ^ (id->src_port) ^
                            (id->proto);
                }
                i = i % fs->rq_size;
                /* finally, scan the current list for a match */
                searches++;
                for (prev = NULL, q = fs->rq[i]; q;) {
                        search_steps++;
                        if (is_v6 &&
                            IN6_ARE_ADDR_EQUAL(&id->dst_ip6, &q->id.dst_ip6) &&
                            IN6_ARE_ADDR_EQUAL(&id->src_ip6, &q->id.src_ip6) &&
                            id->dst_port == q->id.dst_port &&
                            id->src_port == q->id.src_port &&
                            id->proto == q->id.proto &&
                            id->flags == q->id.flags &&
                            id->flow_id6 == q->id.flow_id6) {
                                break; /* found */
                        }
                        if (!is_v6 && id->dst_ip == q->id.dst_ip &&
                            id->src_ip == q->id.src_ip &&
                            id->dst_port == q->id.dst_port &&
                            id->src_port == q->id.src_port &&
                            id->proto == q->id.proto &&
                            id->flags == q->id.flags) {
                                break; /* found */
                        }
                        /* No match. Check if we can expire the entry */
                        if (pipe_expire && q->head == NULL && q->S == q->F + 1) {
                                /* entry is idle and not in any heap, expire it */
                                struct dn_flow_queue *old_q = q;

                                if (prev != NULL) {
                                        prev->next = q = q->next;
                                } else {
                                        fs->rq[i] = q = q->next;
                                }
                                fs->rq_elements--;
                                FREE(old_q, M_DUMMYNET);
                                continue;
                        }
                        prev = q;
                        q = q->next;
                }
                if (q && prev != NULL) { /* found and not in front */
                        prev->next = q->next;
                        q->next = fs->rq[i];
                        fs->rq[i] = q;
                }
        }
        if (q == NULL) { /* no match, need to allocate a new entry */
                q = create_queue(fs, i);
                if (q != NULL) {
                        q->id = *id;
                }
        }
        return q;
}

static int
red_drops(struct dn_flow_set *fs, struct dn_flow_queue *q, int len)
{
        /*
         * RED algorithm
         *
         * RED calculates the average queue size (avg) using a low-pass filter
         * with an exponential weighted (w_q) moving average:
         *      avg  <-  (1-w_q) * avg + w_q * q_size
         * where q_size is the queue length (measured in bytes or * packets).
         *
         * If q_size == 0, we compute the idle time for the link, and set
         *      avg = (1 - w_q)^(idle/s)
         * where s is the time needed for transmitting a medium-sized packet.
         *
         * Now, if avg < min_th the packet is enqueued.
         * If avg > max_th the packet is dropped. Otherwise, the packet is
         * dropped with probability P function of avg.
         *
         */

        int64_t p_b = 0;
        /* queue in bytes or packets ? */
        u_int q_size = (fs->flags_fs & DN_QSIZE_IS_BYTES) ? q->len_bytes : q->len;

        DPRINTF(("\ndummynet: %d q: %2u ", (int) curr_time, q_size));

        /* average queue size estimation */
        if (q_size != 0) {
                /*
                 * queue is not empty, avg <- avg + (q_size - avg) * w_q
                 */
                int diff = SCALE(q_size) - q->avg;
                int64_t v = SCALE_MUL((int64_t) diff, (int64_t) fs->w_q);

                q->avg += (int) v;
        } else {
                /*
                 * queue is empty, find for how long the queue has been
                 * empty and use a lookup table for computing
                 * (1 - * w_q)^(idle_time/s) where s is the time to send a
                 * (small) packet.
                 * XXX check wraps...
                 */
                if (q->avg) {
                        u_int t = (curr_time - q->q_time) / fs->lookup_step;

                        q->avg = (t < fs->lookup_depth) ?
                            SCALE_MUL(q->avg, fs->w_q_lookup[t]) : 0;
                }
        }
        DPRINTF(("dummynet: avg: %u ", SCALE_VAL(q->avg)));

        /* should i drop ? */

        if (q->avg < fs->min_th) {
                q->count = -1;
                return 0; /* accept packet ; */
        }
        if (q->avg >= fs->max_th) { /* average queue >=  max threshold */
                if (fs->flags_fs & DN_IS_GENTLE_RED) {
                        /*
                         * According to Gentle-RED, if avg is greater than max_th the
                         * packet is dropped with a probability
                         *      p_b = c_3 * avg - c_4
                         * where c_3 = (1 - max_p) / max_th, and c_4 = 1 - 2 * max_p
                         */
                        p_b = SCALE_MUL((int64_t) fs->c_3, (int64_t) q->avg) - fs->c_4;
                } else {
                        q->count = -1;
                        DPRINTF(("dummynet: - drop"));
                        return 1;
                }
        } else if (q->avg > fs->min_th) {
                /*
                 * we compute p_b using the linear dropping function p_b = c_1 *
                 * avg - c_2, where c_1 = max_p / (max_th - min_th), and c_2 =
                 * max_p * min_th / (max_th - min_th)
                 */
                p_b = SCALE_MUL((int64_t) fs->c_1, (int64_t) q->avg) - fs->c_2;
        }
        if (fs->flags_fs & DN_QSIZE_IS_BYTES) {
                p_b = (p_b * len) / fs->max_pkt_size;
        }
        if (++q->count == 0) {
                q->random = (my_random() & 0xffff);
        } else {
                /*
                 * q->count counts packets arrived since last drop, so a greater
                 * value of q->count means a greater packet drop probability.
                 */
                if (SCALE_MUL(p_b, SCALE((int64_t) q->count)) > q->random) {
                        q->count = 0;
                        DPRINTF(("dummynet: - red drop"));
                        /* after a drop we calculate a new random value */
                        q->random = (my_random() & 0xffff);
                        return 1; /* drop */
                }
        }
        /* end of RED algorithm */
        return 0; /* accept */
}

static __inline
struct dn_flow_set *
locate_flowset(int fs_nr)
{
        struct dn_flow_set *fs;
        SLIST_FOREACH(fs, &flowsethash[HASH(fs_nr)], next) {
                if (fs->fs_nr == fs_nr) {
                        return fs;
                }
        }

        return NULL;
}

static __inline struct dn_pipe *
locate_pipe(int pipe_nr)
{
        struct dn_pipe *pipe;

        SLIST_FOREACH(pipe, &pipehash[HASH(pipe_nr)], next) {
                if (pipe->pipe_nr == pipe_nr) {
                        return pipe;
                }
        }

        return NULL;
}



/*
 * dummynet hook for packets. Below 'pipe' is a pipe or a queue
 * depending on whether WF2Q or fixed bw is used.
 *
 * pipe_nr      pipe or queue the packet is destined for.
 * dir          where shall we send the packet after dummynet.
 * m            the mbuf with the packet
 * ifp          the 'ifp' parameter from the caller.
 *              NULL in ip_input, destination interface in ip_output,
 *              real_dst in bdg_forward
 * ro           route parameter (only used in ip_output, NULL otherwise)
 * dst          destination address, only used by ip_output
 * rule         matching rule, in case of multiple passes
 * flags        flags from the caller, only used in ip_output
 *
 */
static int
dummynet_io(struct mbuf *m, int pipe_nr, int dir, struct ip_fw_args *fwa)
{
        struct mbuf *head = NULL, *tail = NULL;
        struct dn_pkt_tag *pkt;
        struct m_tag *mtag;
        struct dn_flow_set *fs = NULL;
        struct dn_pipe *pipe;
        u_int64_t len = m->m_pkthdr.len;
        struct dn_flow_queue *q = NULL;
        int is_pipe = 0;
        struct timespec ts;
        struct timeval      tv;

        DPRINTF(("dummynet_io m: 0x%llx pipe: %d dir: %d\n",
            (uint64_t)VM_KERNEL_ADDRPERM(m), pipe_nr, dir));


#if DUMMYNET
        is_pipe = fwa->fwa_flags == DN_IS_PIPE ? 1 : 0;
#endif /* DUMMYNET */

        pipe_nr &= 0xffff;

        lck_mtx_lock(dn_mutex);

        /* make all time measurements in milliseconds (ms) -
         * here we convert secs and usecs to msecs (just divide the
         * usecs and take the closest whole number).
         */
        microuptime(&tv);
        curr_time = (tv.tv_sec * 1000) + (tv.tv_usec / 1000);

        /*
         * This is a dummynet rule, so we expect an O_PIPE or O_QUEUE rule.
         */
        if (is_pipe) {
                pipe = locate_pipe(pipe_nr);
                if (pipe != NULL) {
                        fs = &(pipe->fs);
                }
        } else {
                fs = locate_flowset(pipe_nr);
        }


        if (fs == NULL) {
                goto dropit; /* this queue/pipe does not exist! */
        }
        pipe = fs->pipe;
        if (pipe == NULL) { /* must be a queue, try find a matching pipe */
                pipe = locate_pipe(fs->parent_nr);

                if (pipe != NULL) {
                        fs->pipe = pipe;
                } else {
                        printf("dummynet: no pipe %d for queue %d, drop pkt\n",
                            fs->parent_nr, fs->fs_nr);
                        goto dropit;
                }
        }
        q = find_queue(fs, &(fwa->fwa_id));
        if (q == NULL) {
                goto dropit;    /* cannot allocate queue                */
        }
        /*
         * update statistics, then check reasons to drop pkt
         */
        q->tot_bytes += len;
        q->tot_pkts++;
        if (fs->plr && (my_random() < fs->plr)) {
                goto dropit;    /* random pkt drop                      */
        }
        if (fs->flags_fs & DN_QSIZE_IS_BYTES) {
                if (q->len_bytes > fs->qsize) {
                        goto dropit; /* queue size overflow                     */
                }
        } else {
                if (q->len >= fs->qsize) {
                        goto dropit; /* queue count overflow                    */
                }
        }
        if (fs->flags_fs & DN_IS_RED && red_drops(fs, q, len)) {
                goto dropit;
        }

        /* XXX expensive to zero, see if we can remove it*/
        mtag = m_tag_create(KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_DUMMYNET,
            sizeof(struct dn_pkt_tag), M_NOWAIT, m);
        if (mtag == NULL) {
                goto dropit;            /* cannot allocate packet header        */
        }
        m_tag_prepend(m, mtag); /* attach to mbuf chain */

        pkt = (struct dn_pkt_tag *)(mtag + 1);
        bzero(pkt, sizeof(struct dn_pkt_tag));
        /* ok, i can handle the pkt now... */
        /* build and enqueue packet + parameters */
        pkt->dn_pf_rule = fwa->fwa_pf_rule;
        pkt->dn_dir = dir;

        pkt->dn_ifp = fwa->fwa_oif;
        if (dir == DN_TO_IP_OUT) {
                /*
                 * We need to copy *ro because for ICMP pkts (and maybe others)
                 * the caller passed a pointer into the stack; dst might also be
                 * a pointer into *ro so it needs to be updated.
                 */
                if (fwa->fwa_ro) {
                        route_copyout(&pkt->dn_ro, fwa->fwa_ro, sizeof(pkt->dn_ro));
                }
                if (fwa->fwa_dst) {
                        if (fwa->fwa_dst == (struct sockaddr_in *)&fwa->fwa_ro->ro_dst) { /* dst points into ro */
                                fwa->fwa_dst = (struct sockaddr_in *)&(pkt->dn_ro.ro_dst);
                        }

                        bcopy(fwa->fwa_dst, &pkt->dn_dst, sizeof(pkt->dn_dst));
                }
        } else if (dir == DN_TO_IP6_OUT) {
                if (fwa->fwa_ro6) {
                        route_copyout((struct route *)&pkt->dn_ro6,
                            (struct route *)fwa->fwa_ro6, sizeof(pkt->dn_ro6));
                }
                if (fwa->fwa_ro6_pmtu) {
                        route_copyout((struct route *)&pkt->dn_ro6_pmtu,
                            (struct route *)fwa->fwa_ro6_pmtu, sizeof(pkt->dn_ro6_pmtu));
                }
                if (fwa->fwa_dst6) {
                        if (fwa->fwa_dst6 == (struct sockaddr_in6 *)&fwa->fwa_ro6->ro_dst) { /* dst points into ro */
                                fwa->fwa_dst6 = (struct sockaddr_in6 *)&(pkt->dn_ro6.ro_dst);
                        }

                        bcopy(fwa->fwa_dst6, &pkt->dn_dst6, sizeof(pkt->dn_dst6));
                }
                pkt->dn_origifp = fwa->fwa_origifp;
                pkt->dn_mtu = fwa->fwa_mtu;
                pkt->dn_unfragpartlen = fwa->fwa_unfragpartlen;
                if (fwa->fwa_exthdrs) {
                        bcopy(fwa->fwa_exthdrs, &pkt->dn_exthdrs, sizeof(pkt->dn_exthdrs));
                        /*
                         * Need to zero out the source structure so the mbufs
                         * won't be freed by ip6_output()
                         */
                        bzero(fwa->fwa_exthdrs, sizeof(struct ip6_exthdrs));
                }
        }
        if (dir == DN_TO_IP_OUT || dir == DN_TO_IP6_OUT) {
                pkt->dn_flags = fwa->fwa_oflags;
                if (fwa->fwa_ipoa != NULL) {
                        pkt->dn_ipoa = *(fwa->fwa_ipoa);
                }
        }
        if (q->head == NULL) {
                q->head = m;
        } else {
                q->tail->m_nextpkt = m;
        }
        q->tail = m;
        q->len++;
        q->len_bytes += len;

        if (q->head != m) {     /* flow was not idle, we are done */
                goto done;
        }
        /*
         * If we reach this point the flow was previously idle, so we need
         * to schedule it. This involves different actions for fixed-rate or
         * WF2Q queues.
         */
        if (is_pipe) {
                /*
                 * Fixed-rate queue: just insert into the ready_heap.
                 */
                dn_key t = 0;
                if (pipe->bandwidth) {
                        t = SET_TICKS(m, q, pipe);
                }
                q->sched_time = curr_time;
                if (t == 0) { /* must process it now */
                        ready_event( q, &head, &tail );
                } else {
                        heap_insert(&ready_heap, curr_time + t, q );
                }
        } else {
                /*
                 * WF2Q. First, compute start time S: if the flow was idle (S=F+1)
                 * set S to the virtual time V for the controlling pipe, and update
                 * the sum of weights for the pipe; otherwise, remove flow from
                 * idle_heap and set S to max(F,V).
                 * Second, compute finish time F = S + len/weight.
                 * Third, if pipe was idle, update V=max(S, V).
                 * Fourth, count one more backlogged flow.
                 */
                if (DN_KEY_GT(q->S, q->F)) { /* means timestamps are invalid */
                        q->S = pipe->V;
                        pipe->sum += fs->weight; /* add weight of new queue */
                } else {
                        heap_extract(&(pipe->idle_heap), q);
                        q->S = MAX64(q->F, pipe->V );
                }
                q->F = q->S + (len << MY_M) / (u_int64_t) fs->weight;

                if (pipe->not_eligible_heap.elements == 0 &&
                    pipe->scheduler_heap.elements == 0) {
                        pipe->V = MAX64( q->S, pipe->V );
                }
                fs->backlogged++;
                /*
                 * Look at eligibility. A flow is not eligibile if S>V (when
                 * this happens, it means that there is some other flow already
                 * scheduled for the same pipe, so the scheduler_heap cannot be
                 * empty). If the flow is not eligible we just store it in the
                 * not_eligible_heap. Otherwise, we store in the scheduler_heap
                 * and possibly invoke ready_event_wfq() right now if there is
                 * leftover credit.
                 * Note that for all flows in scheduler_heap (SCH), S_i <= V,
                 * and for all flows in not_eligible_heap (NEH), S_i > V .
                 * So when we need to compute max( V, min(S_i) ) forall i in SCH+NEH,
                 * we only need to look into NEH.
                 */
                if (DN_KEY_GT(q->S, pipe->V)) { /* not eligible */
                        if (pipe->scheduler_heap.elements == 0) {
                                printf("dummynet: ++ ouch! not eligible but empty scheduler!\n");
                        }
                        heap_insert(&(pipe->not_eligible_heap), q->S, q);
                } else {
                        heap_insert(&(pipe->scheduler_heap), q->F, q);
                        if (pipe->numbytes >= 0) { /* pipe is idle */
                                if (pipe->scheduler_heap.elements != 1) {
                                        printf("dummynet: OUCH! pipe should have been idle!\n");
                                }
                                DPRINTF(("dummynet: waking up pipe %d at %d\n",
                                    pipe->pipe_nr, (int)(q->F >> MY_M)));
                                pipe->sched_time = curr_time;
                                ready_event_wfq(pipe, &head, &tail);
                        }
                }
        }
done:
        /* start the timer and set global if not already set */
        if (!timer_enabled) {
                ts.tv_sec = 0;
                ts.tv_nsec = 1 * 1000000;       // 1ms
                timer_enabled = 1;
                bsd_timeout(dummynet, NULL, &ts);
        }

        lck_mtx_unlock(dn_mutex);

        if (head != NULL) {
                dummynet_send(head);
        }

        return 0;

dropit:
        if (q) {
                q->drops++;
        }
        lck_mtx_unlock(dn_mutex);
        m_freem(m);
        return (fs && (fs->flags_fs & DN_NOERROR)) ? 0 : ENOBUFS;
}

/*
 * Below, the ROUTE_RELEASE is only needed when (pkt->dn_dir == DN_TO_IP_OUT)
 * Doing this would probably save us the initial bzero of dn_pkt
 */
#define DN_FREE_PKT(_m) do {                                    \
        struct m_tag *tag = m_tag_locate(m, KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_DUMMYNET, NULL); \
        if (tag) {                                              \
                struct dn_pkt_tag *n = (struct dn_pkt_tag *)(tag+1);    \
                ROUTE_RELEASE(&n->dn_ro);                       \
        }                                                       \
        m_tag_delete(_m, tag);                                  \
        m_freem(_m);                                            \
} while (0)

/*
 * Dispose all packets and flow_queues on a flow_set.
 * If all=1, also remove red lookup table and other storage,
 * including the descriptor itself.
 * For the one in dn_pipe MUST also cleanup ready_heap...
 */
static void
purge_flow_set(struct dn_flow_set *fs, int all)
{
        struct dn_flow_queue *q, *qn;
        int i;

        LCK_MTX_ASSERT(dn_mutex, LCK_MTX_ASSERT_OWNED);

        for (i = 0; i <= fs->rq_size; i++) {
                for (q = fs->rq[i]; q; q = qn) {
                        struct mbuf *m, *mnext;

                        mnext = q->head;
                        while ((m = mnext) != NULL) {
                                mnext = m->m_nextpkt;
                                DN_FREE_PKT(m);
                        }
                        qn = q->next;
                        FREE(q, M_DUMMYNET);
                }
                fs->rq[i] = NULL;
        }
        fs->rq_elements = 0;
        if (all) {
                /* RED - free lookup table */
                if (fs->w_q_lookup) {
                        FREE(fs->w_q_lookup, M_DUMMYNET);
                }
                if (fs->rq) {
                        FREE(fs->rq, M_DUMMYNET);
                }
                /* if this fs is not part of a pipe, free it */
                if (fs->pipe && fs != &(fs->pipe->fs)) {
                        FREE(fs, M_DUMMYNET);
                }
        }
}

/*
 * Dispose all packets queued on a pipe (not a flow_set).
 * Also free all resources associated to a pipe, which is about
 * to be deleted.
 */
static void
purge_pipe(struct dn_pipe *pipe)
{
        struct mbuf *m, *mnext;

        purge_flow_set( &(pipe->fs), 1 );

        mnext = pipe->head;
        while ((m = mnext) != NULL) {
                mnext = m->m_nextpkt;
                DN_FREE_PKT(m);
        }

        heap_free( &(pipe->scheduler_heap));
        heap_free( &(pipe->not_eligible_heap));
        heap_free( &(pipe->idle_heap));
}

/*
 * Delete all pipes and heaps returning memory.
 */
static void
dummynet_flush(void)
{
        struct dn_pipe *pipe, *pipe1;
        struct dn_flow_set *fs, *fs1;
        int i;

        lck_mtx_lock(dn_mutex);


        /* Free heaps so we don't have unwanted events. */
        heap_free(&ready_heap);
        heap_free(&wfq_ready_heap);
        heap_free(&extract_heap);

        /*
         * Now purge all queued pkts and delete all pipes.
         *
         * XXXGL: can we merge the for(;;) cycles into one or not?
         */
        for (i = 0; i < HASHSIZE; i++) {
                SLIST_FOREACH_SAFE(fs, &flowsethash[i], next, fs1) {
                        SLIST_REMOVE(&flowsethash[i], fs, dn_flow_set, next);
                        purge_flow_set(fs, 1);
                }
        }
        for (i = 0; i < HASHSIZE; i++) {
                SLIST_FOREACH_SAFE(pipe, &pipehash[i], next, pipe1) {
                        SLIST_REMOVE(&pipehash[i], pipe, dn_pipe, next);
                        purge_pipe(pipe);
                        FREE(pipe, M_DUMMYNET);
                }
        }
        lck_mtx_unlock(dn_mutex);
}

/*
 * setup RED parameters
 */
static int
config_red(struct dn_flow_set *p, struct dn_flow_set * x)
{
        int i;

        x->w_q = p->w_q;
        x->min_th = SCALE(p->min_th);
        x->max_th = SCALE(p->max_th);
        x->max_p = p->max_p;

        x->c_1 = p->max_p / (p->max_th - p->min_th);
        x->c_2 = SCALE_MUL(x->c_1, SCALE(p->min_th));
        if (x->flags_fs & DN_IS_GENTLE_RED) {
                x->c_3 = (SCALE(1) - p->max_p) / p->max_th;
                x->c_4 = (SCALE(1) - 2 * p->max_p);
        }

        /* if the lookup table already exist, free and create it again */
        if (x->w_q_lookup) {
                FREE(x->w_q_lookup, M_DUMMYNET);
                x->w_q_lookup = NULL;
        }
        if (red_lookup_depth == 0) {
                printf("\ndummynet: net.inet.ip.dummynet.red_lookup_depth must be > 0\n");
                FREE(x, M_DUMMYNET);
                return EINVAL;
        }
        x->lookup_depth = red_lookup_depth;
        x->w_q_lookup = (u_int *) _MALLOC(x->lookup_depth * sizeof(int),
            M_DUMMYNET, M_DONTWAIT);
        if (x->w_q_lookup == NULL) {
                printf("dummynet: sorry, cannot allocate red lookup table\n");
                FREE(x, M_DUMMYNET);
                return ENOSPC;
        }

        /* fill the lookup table with (1 - w_q)^x */
        x->lookup_step = p->lookup_step;
        x->lookup_weight = p->lookup_weight;
        x->w_q_lookup[0] = SCALE(1) - x->w_q;
        for (i = 1; i < x->lookup_depth; i++) {
                x->w_q_lookup[i] = SCALE_MUL(x->w_q_lookup[i - 1], x->lookup_weight);
        }
        if (red_avg_pkt_size < 1) {
                red_avg_pkt_size = 512;
        }
        x->avg_pkt_size = red_avg_pkt_size;
        if (red_max_pkt_size < 1) {
                red_max_pkt_size = 1500;
        }
        x->max_pkt_size = red_max_pkt_size;
        return 0;
}

static int
alloc_hash(struct dn_flow_set *x, struct dn_flow_set *pfs)
{
        if (x->flags_fs & DN_HAVE_FLOW_MASK) { /* allocate some slots */
                int l = pfs->rq_size;

                if (l == 0) {
                        l = dn_hash_size;
                }
                if (l < 4) {
                        l = 4;
                } else if (l > DN_MAX_HASH_SIZE) {
                        l = DN_MAX_HASH_SIZE;
                }
                x->rq_size = l;
        } else {            /* one is enough for null mask */
                x->rq_size = 1;
        }
        x->rq = _MALLOC((1 + x->rq_size) * sizeof(struct dn_flow_queue *),
            M_DUMMYNET, M_DONTWAIT | M_ZERO);
        if (x->rq == NULL) {
                printf("dummynet: sorry, cannot allocate queue\n");
                return ENOSPC;
        }
        x->rq_elements = 0;
        return 0;
}

static void
set_fs_parms(struct dn_flow_set *x, struct dn_flow_set *src)
{
        x->flags_fs = src->flags_fs;
        x->qsize = src->qsize;
        x->plr = src->plr;
        x->flow_mask = src->flow_mask;
        if (x->flags_fs & DN_QSIZE_IS_BYTES) {
                if (x->qsize > 1024 * 1024) {
                        x->qsize = 1024 * 1024;
                }
        } else {
                if (x->qsize == 0) {
                        x->qsize = 50;
                }
                if (x->qsize > 100) {
                        x->qsize = 50;
                }
        }
        /* configuring RED */
        if (x->flags_fs & DN_IS_RED) {
                config_red(src, x); /* XXX should check errors */
        }
}

/*
 * setup pipe or queue parameters.
 */
static int
config_pipe(struct dn_pipe *p)
{
        int i, r;
        struct dn_flow_set *pfs = &(p->fs);
        struct dn_flow_queue *q;

        /*
         * The config program passes parameters as follows:
         * bw = bits/second (0 means no limits),
         * delay = ms, must be translated into ticks.
         * qsize = slots/bytes
         */
        p->delay = (p->delay * (hz * 10)) / 1000;
        /* We need either a pipe number or a flow_set number */
        if (p->pipe_nr == 0 && pfs->fs_nr == 0) {
                return EINVAL;
        }
        if (p->pipe_nr != 0 && pfs->fs_nr != 0) {
                return EINVAL;
        }
        if (p->pipe_nr != 0) { /* this is a pipe */
                struct dn_pipe *x, *b;
                struct dummynet_event dn_event;
                lck_mtx_lock(dn_mutex);

                /* locate pipe */
                b = locate_pipe(p->pipe_nr);

                if (b == NULL || b->pipe_nr != p->pipe_nr) { /* new pipe */
                        x = _MALLOC(sizeof(struct dn_pipe), M_DUMMYNET, M_DONTWAIT | M_ZERO);
                        if (x == NULL) {
                                lck_mtx_unlock(dn_mutex);
                                printf("dummynet: no memory for new pipe\n");
                                return ENOSPC;
                        }
                        x->pipe_nr = p->pipe_nr;
                        x->fs.pipe = x;
                        /* idle_heap is the only one from which we extract from the middle.
                         */
                        x->idle_heap.size = x->idle_heap.elements = 0;
                        x->idle_heap.offset = offsetof(struct dn_flow_queue, heap_pos);
                } else {
                        x = b;
                        /* Flush accumulated credit for all queues */
                        for (i = 0; i <= x->fs.rq_size; i++) {
                                for (q = x->fs.rq[i]; q; q = q->next) {
                                        q->numbytes = 0;
                                }
                        }
                }

                x->bandwidth = p->bandwidth;
                x->numbytes = 0; /* just in case... */
                bcopy(p->if_name, x->if_name, sizeof(p->if_name));
                x->ifp = NULL; /* reset interface ptr */
                x->delay = p->delay;
                set_fs_parms(&(x->fs), pfs);


                if (x->fs.rq == NULL) { /* a new pipe */
                        r = alloc_hash(&(x->fs), pfs);
                        if (r) {
                                lck_mtx_unlock(dn_mutex);
                                FREE(x, M_DUMMYNET);
                                return r;
                        }
                        SLIST_INSERT_HEAD(&pipehash[HASH(x->pipe_nr)],
                            x, next);
                }
                lck_mtx_unlock(dn_mutex);

                bzero(&dn_event, sizeof(dn_event));
                dn_event.dn_event_code = DUMMYNET_PIPE_CONFIG;
                dn_event.dn_event_pipe_config.bandwidth = p->bandwidth;
                dn_event.dn_event_pipe_config.delay = p->delay;
                dn_event.dn_event_pipe_config.plr = pfs->plr;

                dummynet_event_enqueue_nwk_wq_entry(&dn_event);
        } else { /* config queue */
                struct dn_flow_set *x, *b;

                lck_mtx_lock(dn_mutex);
                /* locate flow_set */
                b = locate_flowset(pfs->fs_nr);

                if (b == NULL || b->fs_nr != pfs->fs_nr) { /* new  */
                        if (pfs->parent_nr == 0) { /* need link to a pipe */
                                lck_mtx_unlock(dn_mutex);
                                return EINVAL;
                        }
                        x = _MALLOC(sizeof(struct dn_flow_set), M_DUMMYNET, M_DONTWAIT | M_ZERO);
                        if (x == NULL) {
                                lck_mtx_unlock(dn_mutex);
                                printf("dummynet: no memory for new flow_set\n");
                                return ENOSPC;
                        }
                        x->fs_nr = pfs->fs_nr;
                        x->parent_nr = pfs->parent_nr;
                        x->weight = pfs->weight;
                        if (x->weight == 0) {
                                x->weight = 1;
                        } else if (x->weight > 100) {
                                x->weight = 100;
                        }
                } else {
                        /* Change parent pipe not allowed; must delete and recreate */
                        if (pfs->parent_nr != 0 && b->parent_nr != pfs->parent_nr) {
                                lck_mtx_unlock(dn_mutex);
                                return EINVAL;
                        }
                        x = b;
                }
                set_fs_parms(x, pfs);

                if (x->rq == NULL) { /* a new flow_set */
                        r = alloc_hash(x, pfs);
                        if (r) {
                                lck_mtx_unlock(dn_mutex);
                                FREE(x, M_DUMMYNET);
                                return r;
                        }
                        SLIST_INSERT_HEAD(&flowsethash[HASH(x->fs_nr)],
                            x, next);
                }
                lck_mtx_unlock(dn_mutex);
        }
        return 0;
}

/*
 * Helper function to remove from a heap queues which are linked to
 * a flow_set about to be deleted.
 */
static void
fs_remove_from_heap(struct dn_heap *h, struct dn_flow_set *fs)
{
        int i = 0, found = 0;
        for (; i < h->elements;) {
                if (((struct dn_flow_queue *)h->p[i].object)->fs == fs) {
                        h->elements--;
                        h->p[i] = h->p[h->elements];
                        found++;
                } else {
                        i++;
                }
        }
        if (found) {
                heapify(h);
        }
}

/*
 * helper function to remove a pipe from a heap (can be there at most once)
 */
static void
pipe_remove_from_heap(struct dn_heap *h, struct dn_pipe *p)
{
        if (h->elements > 0) {
                int i = 0;
                for (i = 0; i < h->elements; i++) {
                        if (h->p[i].object == p) { /* found it */
                                h->elements--;
                                h->p[i] = h->p[h->elements];
                                heapify(h);
                                break;
                        }
                }
        }
}

/*
 * drain all queues. Called in case of severe mbuf shortage.
 */
void
dummynet_drain(void)
{
        struct dn_flow_set *fs;
        struct dn_pipe *p;
        struct mbuf *m, *mnext;
        int i;

        LCK_MTX_ASSERT(dn_mutex, LCK_MTX_ASSERT_OWNED);

        heap_free(&ready_heap);
        heap_free(&wfq_ready_heap);
        heap_free(&extract_heap);
        /* remove all references to this pipe from flow_sets */
        for (i = 0; i < HASHSIZE; i++) {
                SLIST_FOREACH(fs, &flowsethash[i], next) {
                        purge_flow_set(fs, 0);
                }
        }

        for (i = 0; i < HASHSIZE; i++) {
                SLIST_FOREACH(p, &pipehash[i], next) {
                        purge_flow_set(&(p->fs), 0);

                        mnext = p->head;
                        while ((m = mnext) != NULL) {
                                mnext = m->m_nextpkt;
                                DN_FREE_PKT(m);
                        }
                        p->head = p->tail = NULL;
                }
        }
}

/*
 * Fully delete a pipe or a queue, cleaning up associated info.
 */
static int
delete_pipe(struct dn_pipe *p)
{
        if (p->pipe_nr == 0 && p->fs.fs_nr == 0) {
                return EINVAL;
        }
        if (p->pipe_nr != 0 && p->fs.fs_nr != 0) {
                return EINVAL;
        }
        if (p->pipe_nr != 0) { /* this is an old-style pipe */
                struct dn_pipe *b;
                struct dn_flow_set *fs;
                int i;

                lck_mtx_lock(dn_mutex);
                /* locate pipe */
                b = locate_pipe(p->pipe_nr);
                if (b == NULL) {
                        lck_mtx_unlock(dn_mutex);
                        return EINVAL; /* not found */
                }

                /* Unlink from list of pipes. */
                SLIST_REMOVE(&pipehash[HASH(b->pipe_nr)], b, dn_pipe, next);


                /* Remove all references to this pipe from flow_sets. */
                for (i = 0; i < HASHSIZE; i++) {
                        SLIST_FOREACH(fs, &flowsethash[i], next) {
                                if (fs->pipe == b) {
                                        printf("dummynet: ++ ref to pipe %d from fs %d\n",
                                            p->pipe_nr, fs->fs_nr);
                                        fs->pipe = NULL;
                                        purge_flow_set(fs, 0);
                                }
                        }
                }
                fs_remove_from_heap(&ready_heap, &(b->fs));

                purge_pipe(b); /* remove all data associated to this pipe */
                /* remove reference to here from extract_heap and wfq_ready_heap */
                pipe_remove_from_heap(&extract_heap, b);
                pipe_remove_from_heap(&wfq_ready_heap, b);
                lck_mtx_unlock(dn_mutex);

                FREE(b, M_DUMMYNET);
        } else { /* this is a WF2Q queue (dn_flow_set) */
                struct dn_flow_set *b;

                lck_mtx_lock(dn_mutex);
                /* locate set */
                b = locate_flowset(p->fs.fs_nr);
                if (b == NULL) {
                        lck_mtx_unlock(dn_mutex);
                        return EINVAL; /* not found */
                }


                /* Unlink from list of flowsets. */
                SLIST_REMOVE( &flowsethash[HASH(b->fs_nr)], b, dn_flow_set, next);

                if (b->pipe != NULL) {
                        /* Update total weight on parent pipe and cleanup parent heaps */
                        b->pipe->sum -= b->weight * b->backlogged;
                        fs_remove_from_heap(&(b->pipe->not_eligible_heap), b);
                        fs_remove_from_heap(&(b->pipe->scheduler_heap), b);
#if 1   /* XXX should i remove from idle_heap as well ? */
                        fs_remove_from_heap(&(b->pipe->idle_heap), b);
#endif
                }
                purge_flow_set(b, 1);
                lck_mtx_unlock(dn_mutex);
        }
        return 0;
}

/*
 * helper function used to copy data from kernel in DUMMYNET_GET
 */
static
char*
dn_copy_set_32(struct dn_flow_set *set, char *bp)
{
        int i, copied = 0;
        struct dn_flow_queue *q;
        struct dn_flow_queue_32 *qp = (struct dn_flow_queue_32 *)bp;

        LCK_MTX_ASSERT(dn_mutex, LCK_MTX_ASSERT_OWNED);

        for (i = 0; i <= set->rq_size; i++) {
                for (q = set->rq[i]; q; q = q->next, qp++) {
                        if (q->hash_slot != i) {
                                printf("dummynet: ++ at %d: wrong slot (have %d, "
                                    "should be %d)\n", copied, q->hash_slot, i);
                        }
                        if (q->fs != set) {
                                printf("dummynet: ++ at %d: wrong fs ptr "
                                    "(have 0x%llx, should be 0x%llx)\n", i,
                                    (uint64_t)VM_KERNEL_ADDRPERM(q->fs),
                                    (uint64_t)VM_KERNEL_ADDRPERM(set));
                        }
                        copied++;
                        cp_queue_to_32_user( q, qp );
                        /* cleanup pointers */
                        qp->next = (user32_addr_t)0;
                        qp->head = qp->tail = (user32_addr_t)0;
                        qp->fs = (user32_addr_t)0;
                }
        }
        if (copied != set->rq_elements) {
                printf("dummynet: ++ wrong count, have %d should be %d\n",
                    copied, set->rq_elements);
        }
        return (char *)qp;
}

static
char*
dn_copy_set_64(struct dn_flow_set *set, char *bp)
{
        int i, copied = 0;
        struct dn_flow_queue *q;
        struct dn_flow_queue_64 *qp = (struct dn_flow_queue_64 *)bp;

        LCK_MTX_ASSERT(dn_mutex, LCK_MTX_ASSERT_OWNED);

        for (i = 0; i <= set->rq_size; i++) {
                for (q = set->rq[i]; q; q = q->next, qp++) {
                        if (q->hash_slot != i) {
                                printf("dummynet: ++ at %d: wrong slot (have %d, "
                                    "should be %d)\n", copied, q->hash_slot, i);
                        }
                        if (q->fs != set) {
                                printf("dummynet: ++ at %d: wrong fs ptr "
                                    "(have 0x%llx, should be 0x%llx)\n", i,
                                    (uint64_t)VM_KERNEL_ADDRPERM(q->fs),
                                    (uint64_t)VM_KERNEL_ADDRPERM(set));
                        }
                        copied++;
                        //bcopy(q, qp, sizeof(*q));
                        cp_queue_to_64_user( q, qp );
                        /* cleanup pointers */
                        qp->next = USER_ADDR_NULL;
                        qp->head = qp->tail = USER_ADDR_NULL;
                        qp->fs = USER_ADDR_NULL;
                }
        }
        if (copied != set->rq_elements) {
                printf("dummynet: ++ wrong count, have %d should be %d\n",
                    copied, set->rq_elements);
        }
        return (char *)qp;
}

static size_t
dn_calc_size(int is64user)
{
        struct dn_flow_set *set;
        struct dn_pipe *p;
        size_t size = 0;
        size_t pipesize;
        size_t queuesize;
        size_t setsize;
        int i;

        LCK_MTX_ASSERT(dn_mutex, LCK_MTX_ASSERT_OWNED);
        if (is64user) {
                pipesize = sizeof(struct dn_pipe_64);
                queuesize = sizeof(struct dn_flow_queue_64);
                setsize = sizeof(struct dn_flow_set_64);
        } else {
                pipesize = sizeof(struct dn_pipe_32);
                queuesize = sizeof(struct dn_flow_queue_32);
                setsize = sizeof(struct dn_flow_set_32);
        }
        /*
         * compute size of data structures: list of pipes and flow_sets.
         */
        for (i = 0; i < HASHSIZE; i++) {
                SLIST_FOREACH(p, &pipehash[i], next) {
                        size += sizeof(*p) +
                            p->fs.rq_elements * sizeof(struct dn_flow_queue);
                }
                SLIST_FOREACH(set, &flowsethash[i], next) {
                        size += sizeof(*set) +
                            set->rq_elements * sizeof(struct dn_flow_queue);
                }
        }
        return size;
}

static int
dummynet_get(struct sockopt *sopt)
{
        char *buf = NULL, *bp = NULL; /* bp is the "copy-pointer" */
        size_t size = 0;
        struct dn_flow_set *set;
        struct dn_pipe *p;
        int error = 0, i;
        int is64user = 0;

        /* XXX lock held too long */
        lck_mtx_lock(dn_mutex);
        /*
         * XXX: Ugly, but we need to allocate memory with M_WAITOK flag
         * and we cannot use this flag while holding a mutex.
         */
        if (proc_is64bit(sopt->sopt_p)) {
                is64user = 1;
        }
        for (i = 0; i < 10; i++) {
                size = dn_calc_size(is64user);
                lck_mtx_unlock(dn_mutex);
                buf = _MALLOC(size, M_TEMP, M_WAITOK | M_ZERO);
                if (buf == NULL) {
                        return ENOBUFS;
                }
                lck_mtx_lock(dn_mutex);
                if (size == dn_calc_size(is64user)) {
                        break;
                }
                FREE(buf, M_TEMP);
                buf = NULL;
        }
        if (buf == NULL) {
                lck_mtx_unlock(dn_mutex);
                return ENOBUFS;
        }

        bp = buf;
        for (i = 0; i < HASHSIZE; i++) {
                SLIST_FOREACH(p, &pipehash[i], next) {
                        /*
                         * copy pipe descriptor into *bp, convert delay
                         * back to ms, then copy the flow_set descriptor(s)
                         * one at a time. After each flow_set, copy the
                         * queue descriptor it owns.
                         */
                        if (is64user) {
                                bp = cp_pipe_to_64_user(p,
                                    (struct dn_pipe_64 *)bp);
                        } else {
                                bp = cp_pipe_to_32_user(p,
                                    (struct dn_pipe_32 *)bp);
                        }
                }
        }
        for (i = 0; i < HASHSIZE; i++) {
                SLIST_FOREACH(set, &flowsethash[i], next) {
                        struct dn_flow_set_64 *fs_bp =
                            (struct dn_flow_set_64 *)bp;
                        cp_flow_set_to_64_user(set, fs_bp);
                        /* XXX same hack as above */
                        fs_bp->next = CAST_DOWN(user64_addr_t,
                            DN_IS_QUEUE);
                        fs_bp->pipe = USER_ADDR_NULL;
                        fs_bp->rq = USER_ADDR_NULL;
                        bp += sizeof(struct dn_flow_set_64);
                        bp = dn_copy_set_64( set, bp );
                }
        }
        lck_mtx_unlock(dn_mutex);
        error = sooptcopyout(sopt, buf, size);
        FREE(buf, M_TEMP);
        return error;
}

/*
 * Handler for the various dummynet socket options (get, flush, config, del)
 */
static int
ip_dn_ctl(struct sockopt *sopt)
{
        int error = 0;
        struct dn_pipe *p, tmp_pipe;

        /* Disallow sets in really-really secure mode. */
        if (sopt->sopt_dir == SOPT_SET && securelevel >= 3) {
                return EPERM;
        }

        switch (sopt->sopt_name) {
        default:
                printf("dummynet: -- unknown option %d", sopt->sopt_name);
                return EINVAL;

        case IP_DUMMYNET_GET:
                error = dummynet_get(sopt);
                break;

        case IP_DUMMYNET_FLUSH:
                dummynet_flush();
                break;

        case IP_DUMMYNET_CONFIGURE:
                p = &tmp_pipe;
                if (proc_is64bit(sopt->sopt_p)) {
                        error = cp_pipe_from_user_64( sopt, p );
                } else {
                        error = cp_pipe_from_user_32( sopt, p );
                }

                if (error) {
                        break;
                }
                error = config_pipe(p);
                break;

        case IP_DUMMYNET_DEL:   /* remove a pipe or queue */
                p = &tmp_pipe;
                if (proc_is64bit(sopt->sopt_p)) {
                        error = cp_pipe_from_user_64( sopt, p );
                } else {
                        error = cp_pipe_from_user_32( sopt, p );
                }
                if (error) {
                        break;
                }

                error = delete_pipe(p);
                break;
        }
        return error;
}

void
dummynet_init(void)
{
        eventhandler_lists_ctxt_init(&dummynet_evhdlr_ctxt);
}

void
ip_dn_init(void)
{
        /* setup locks */
        dn_mutex_grp_attr = lck_grp_attr_alloc_init();
        dn_mutex_grp = lck_grp_alloc_init("dn", dn_mutex_grp_attr);
        dn_mutex_attr = lck_attr_alloc_init();
        lck_mtx_init(dn_mutex, dn_mutex_grp, dn_mutex_attr);

        ready_heap.size = ready_heap.elements = 0;
        ready_heap.offset = 0;

        wfq_ready_heap.size = wfq_ready_heap.elements = 0;
        wfq_ready_heap.offset = 0;

        extract_heap.size = extract_heap.elements = 0;
        extract_heap.offset = 0;
        ip_dn_ctl_ptr = ip_dn_ctl;
        ip_dn_io_ptr = dummynet_io;
}

struct dn_event_nwk_wq_entry {
        struct nwk_wq_entry nwk_wqe;
        struct dummynet_event dn_ev_arg;
};

static void
dummynet_event_callback(void *arg)
{
        struct dummynet_event *p_dn_ev = (struct dummynet_event *)arg;

        EVENTHANDLER_INVOKE(&dummynet_evhdlr_ctxt, dummynet_event, p_dn_ev);
        return;
}

void
dummynet_event_enqueue_nwk_wq_entry(struct dummynet_event *p_dn_event)
{
        struct dn_event_nwk_wq_entry *p_dn_ev = NULL;

        MALLOC(p_dn_ev, struct dn_event_nwk_wq_entry *,
            sizeof(struct dn_event_nwk_wq_entry),
            M_NWKWQ, M_WAITOK | M_ZERO);

        p_dn_ev->nwk_wqe.func = dummynet_event_callback;
        p_dn_ev->nwk_wqe.is_arg_managed = TRUE;
        p_dn_ev->nwk_wqe.arg = &p_dn_ev->dn_ev_arg;

        bcopy(p_dn_event, &(p_dn_ev->dn_ev_arg),
            sizeof(struct dummynet_event));
        nwk_wq_enqueue((struct nwk_wq_entry*)p_dn_ev);
}