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freebsd/sys/netinet/ip_dummynet.c
2007-06-17 00:33:34 +00:00

2207 lines
60 KiB
C

/*-
* 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.
*
* $FreeBSD$
*/
#define DUMMYNET_DEBUG
#include "opt_inet6.h"
/*
* This module implements IP dummynet, a bandwidth limiter/delay emulator
* used in conjunction with the ipfw package.
* 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:
*
* 011004: KLDable
* 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/kernel.h>
#include <sys/module.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <sys/taskqueue.h>
#include <net/if.h>
#include <net/netisr.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_fw.h>
#include <netinet/ip_dummynet.h>
#include <netinet/ip_var.h>
#include <netinet/if_ether.h> /* for struct arpcom */
#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_timeout.c)
*/
static dn_key curr_time = 0 ; /* current simulation time */
static int dn_hash_size = 64 ; /* default hash size */
/* statistics on number of queue searches and search steps */
static long 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 struct timeval prev_t, t;
static long tick_last; /* Last tick duration (usec). */
static long tick_delta; /* Last vs standard tick diff (usec). */
static long tick_delta_sum; /* Accumulated tick difference (usec).*/
static long tick_adjustment; /* Tick adjustments done. */
static long tick_lost; /* Lost(coalesced) ticks number. */
/* Adjusted vs non-adjusted curr_time difference (ticks). */
static long tick_diff;
/*
* 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.
*
*/
MALLOC_DEFINE(M_DUMMYNET, "dummynet", "dummynet heap");
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);
#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 */
static struct callout dn_timeout;
extern void (*bridge_dn_p)(struct mbuf *, struct ifnet *);
#ifdef SYSCTL_NODE
SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet, CTLFLAG_RW, 0, "Dummynet");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, hash_size,
CTLFLAG_RW, &dn_hash_size, 0, "Default hash table size");
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, curr_time,
CTLFLAG_RD, &curr_time, 0, "Current tick");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, ready_heap,
CTLFLAG_RD, &ready_heap.size, 0, "Size of ready heap");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, extract_heap,
CTLFLAG_RD, &extract_heap.size, 0, "Size of extract heap");
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, searches,
CTLFLAG_RD, &searches, 0, "Number of queue searches");
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, search_steps,
CTLFLAG_RD, &search_steps, 0, "Number of queue search steps");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, expire,
CTLFLAG_RW, &pipe_expire, 0, "Expire queue if empty");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, max_chain_len,
CTLFLAG_RW, &dn_max_ratio, 0,
"Max ratio between dynamic queues and buckets");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_lookup_depth,
CTLFLAG_RD, &red_lookup_depth, 0, "Depth of RED lookup table");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_avg_pkt_size,
CTLFLAG_RD, &red_avg_pkt_size, 0, "RED Medium packet size");
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_max_pkt_size,
CTLFLAG_RD, &red_max_pkt_size, 0, "RED Max packet size");
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_delta,
CTLFLAG_RD, &tick_delta, 0, "Last vs standard tick difference (usec).");
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_delta_sum,
CTLFLAG_RD, &tick_delta_sum, 0, "Accumulated tick difference (usec).");
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_adjustment,
CTLFLAG_RD, &tick_adjustment, 0, "Tick adjustments done.");
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_diff,
CTLFLAG_RD, &tick_diff, 0,
"Adjusted vs non-adjusted curr_time difference (ticks).");
SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_lost,
CTLFLAG_RD, &tick_lost, 0,
"Number of ticks coalesced by dummynet taskqueue.");
#endif
#ifdef DUMMYNET_DEBUG
int dummynet_debug = 0;
#ifdef SYSCTL_NODE
SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, debug, CTLFLAG_RW, &dummynet_debug,
0, "control debugging printfs");
#endif
#define DPRINTF(X) if (dummynet_debug) printf X
#else
#define DPRINTF(X)
#endif
static struct task dn_task;
static struct taskqueue *dn_tq = NULL;
static void dummynet_task(void *, int);
static struct mtx dummynet_mtx;
#define DUMMYNET_LOCK_INIT() \
mtx_init(&dummynet_mtx, "dummynet", NULL, MTX_DEF)
#define DUMMYNET_LOCK_DESTROY() mtx_destroy(&dummynet_mtx)
#define DUMMYNET_LOCK() mtx_lock(&dummynet_mtx)
#define DUMMYNET_UNLOCK() mtx_unlock(&dummynet_mtx)
#define DUMMYNET_LOCK_ASSERT() do { \
mtx_assert(&dummynet_mtx, MA_OWNED); \
NET_ASSERT_GIANT(); \
} while (0)
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);
static void dummynet_send(struct mbuf *);
void dummynet_drain(void);
static ip_dn_io_t dummynet_io;
static void dn_rule_delete(void *);
/*
* 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
static int
heap_init(struct dn_heap *h, int new_size)
{
struct dn_heap_entry *p;
if (h->size >= new_size ) {
printf("dummynet: %s, Bogus call, have %d want %d\n", __func__,
h->size, new_size);
return 0 ;
}
new_size = (new_size + HEAP_INCREMENT ) & ~HEAP_INCREMENT ;
p = malloc(new_size * sizeof(*p), M_DUMMYNET, M_NOWAIT);
if (p == NULL) {
printf("dummynet: %s, resize %d failed\n", __func__, 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, max = h->elements - 1 ;
if (max < 0) {
printf("dummynet: warning, extract from empty heap 0x%p\n", 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 <= max) { /* valid entry */
if (child != max && 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 != max) {
/*
* Fill hole with last entry and bubble up, reusing the insert code
*/
h->p[father] = h->p[max] ;
heap_insert(h, father, NULL); /* this one cannot fail */
}
}
#if 0
/*
* change object position and update references
* XXX this one is never used!
*/
static void
heap_move(struct dn_heap *h, dn_key new_key, void *object)
{
int temp;
int i ;
int max = h->elements-1 ;
struct dn_heap_entry buf ;
if (h->offset <= 0)
panic("cannot move items on this heap");
i = *((int *)((char *)object + h->offset));
if (DN_KEY_LT(new_key, h->p[i].key) ) { /* must move up */
h->p[i].key = new_key ;
for (; i>0 && DN_KEY_LT(new_key, h->p[(temp = HEAP_FATHER(i))].key) ;
i = temp ) { /* bubble up */
HEAP_SWAP(h->p[i], h->p[temp], buf) ;
SET_OFFSET(h, i);
}
} else { /* must move down */
h->p[i].key = new_key ;
while ( (temp = HEAP_LEFT(i)) <= max ) { /* found left child */
if ((temp != max) && DN_KEY_GT(h->p[temp].key, h->p[temp+1].key))
temp++ ; /* select child with min key */
if (DN_KEY_GT(new_key, h->p[temp].key)) { /* go down */
HEAP_SWAP(h->p[i], h->p[temp], buf) ;
SET_OFFSET(h, i);
} else
break ;
i = temp ;
}
}
SET_OFFSET(h, i);
}
#endif /* heap_move, unused */
/*
* 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);
KASSERT(mtag != NULL &&
mtag->m_tag_cookie == MTAG_ABI_COMPAT &&
mtag->m_tag_id == PACKET_TAG_DUMMYNET,
("packet on dummynet queue w/o dummynet tag!"));
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;
DUMMYNET_LOCK_ASSERT();
while ((m = pipe->head) != NULL) {
pkt = dn_tag_get(m);
if (!DN_KEY_LEQ(pkt->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;
/* If there are leftover packets, put into the heap for next 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, pkt->output_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)
*/
#define SET_TICKS(_m, q, p) \
((_m)->m_pkthdr.len*8*hz - (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->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 ;
DUMMYNET_LOCK_ASSERT();
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 : 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() 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) ;
DUMMYNET_LOCK_ASSERT();
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 && p->ifp->if_snd.ifq_head != NULL)
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 : 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)->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.
*/
}
/*
* If the delay line was empty call transmit_event() now.
* Otherwise, the scheduler will take care of it.
*/
if (p_was_empty)
transmit_event(p, head, tail);
}
/*
* This is called one tick, after previous run. It is used to
* schedule next run.
*/
static void
dummynet(void * __unused unused)
{
taskqueue_enqueue(dn_tq, &dn_task);
}
/*
* The main dummynet processing function.
*/
static void
dummynet_task(void *context, int pending)
{
struct mbuf *head = NULL, *tail = NULL;
struct dn_pipe *pipe;
struct dn_heap *heaps[3];
struct dn_heap *h;
void *p; /* generic parameter to handler */
int i;
NET_LOCK_GIANT();
DUMMYNET_LOCK();
heaps[0] = &ready_heap; /* fixed-rate queues */
heaps[1] = &wfq_ready_heap; /* wfq queues */
heaps[2] = &extract_heap; /* delay line */
/* Update number of lost(coalesced) ticks. */
tick_lost += pending - 1;
getmicrouptime(&t);
/* Last tick duration (usec). */
tick_last = (t.tv_sec - prev_t.tv_sec) * 1000000 +
(t.tv_usec - prev_t.tv_usec);
/* Last tick vs standard tick difference (usec). */
tick_delta = (tick_last * hz - 1000000) / hz;
/* Accumulated tick difference (usec). */
tick_delta_sum += tick_delta;
prev_t = t;
/*
* Adjust curr_time if accumulated tick difference greater than
* 'standard' tick. Since curr_time should be monotonically increasing,
* we do positive adjustment as required and throttle curr_time in
* case of negative adjustment.
*/
curr_time++;
if (tick_delta_sum - tick >= 0) {
int diff = tick_delta_sum / tick;
curr_time += diff;
tick_diff += diff;
tick_delta_sum %= tick;
tick_adjustment++;
} else if (tick_delta_sum + tick <= 0) {
curr_time--;
tick_diff--;
tick_delta_sum += tick;
tick_adjustment++;
}
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));
/* store a copy before heap_extract */
p = h->p[0].object;
/* need to extract before processing */
heap_extract(h, NULL);
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(pipe, &pipehash[i], next)
if (pipe->idle_heap.elements > 0 &&
DN_KEY_LT(pipe->idle_heap.p[0].key, pipe->V)) {
struct dn_flow_queue *q =
pipe->idle_heap.p[0].object;
heap_extract(&(pipe->idle_heap), NULL);
/* Mark timestamp as invalid. */
q->S = q->F + 1;
pipe->sum -= q->fs->weight;
}
DUMMYNET_UNLOCK();
if (head != NULL)
dummynet_send(head);
callout_reset(&dn_timeout, 1, dummynet, NULL);
NET_UNLOCK_GIANT();
}
static void
dummynet_send(struct mbuf *m)
{
struct dn_pkt_tag *pkt;
struct mbuf *n;
struct ip *ip;
for (; m != NULL; m = n) {
n = m->m_nextpkt;
m->m_nextpkt = NULL;
pkt = dn_tag_get(m);
switch (pkt->dn_dir) {
case DN_TO_IP_OUT:
ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL);
break ;
case DN_TO_IP_IN :
ip = mtod(m, struct ip *);
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
netisr_dispatch(NETISR_IP, m);
break;
#ifdef INET6
case DN_TO_IP6_IN:
netisr_dispatch(NETISR_IPV6, m);
break;
case DN_TO_IP6_OUT:
ip6_output(m, NULL, NULL, IPV6_FORWARDING, NULL, NULL, NULL);
break;
#endif
case DN_TO_IFB_FWD:
if (bridge_dn_p != NULL)
((*bridge_dn_p)(m, pkt->ifp));
else
printf("dummynet: if_bridge not loaded\n");
break;
case DN_TO_ETH_DEMUX:
/*
* The Ethernet code assumes the Ethernet header is
* contiguous in the first mbuf header.
* Insure this is true.
*/
if (m->m_len < ETHER_HDR_LEN &&
(m = m_pullup(m, ETHER_HDR_LEN)) == NULL) {
printf("dummynet/ether: pullup failed, "
"dropping packet\n");
break;
}
ether_demux(m->m_pkthdr.rcvif, m);
break;
case DN_TO_ETH_OUT:
ether_output_frame(pkt->ifp, 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 ;
if (fs->last_expired == time_uptime)
return 0 ;
fs->last_expired = time_uptime ;
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_NOWAIT | 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 ipfw_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
* 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)
* 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 = 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 = 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,
* rule matching rule, in case of multiple passes
*
*/
static int
dummynet_io(struct mbuf *m, 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;
ipfw_insn *cmd = ACTION_PTR(fwa->rule);
KASSERT(m->m_nextpkt == NULL,
("dummynet_io: mbuf queue passed to dummynet"));
if (cmd->opcode == O_LOG)
cmd += F_LEN(cmd);
if (cmd->opcode == O_ALTQ)
cmd += F_LEN(cmd);
if (cmd->opcode == O_TAG)
cmd += F_LEN(cmd);
is_pipe = (cmd->opcode == O_PIPE);
DUMMYNET_LOCK();
/*
* This is a dummynet rule, so we expect an O_PIPE or O_QUEUE rule.
*
* XXXGL: probably the pipe->fs and fs->pipe logic here
* below can be simplified.
*/
if (is_pipe) {
pipe = locate_pipe(fwa->cookie);
if (pipe != NULL)
fs = &(pipe->fs);
} else
fs = locate_flowset(fwa->cookie);
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->f_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 && 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_get(PACKET_TAG_DUMMYNET,
sizeof(struct dn_pkt_tag), M_NOWAIT|M_ZERO);
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);
/* ok, i can handle the pkt now... */
/* build and enqueue packet + parameters */
pkt->rule = fwa->rule ;
pkt->dn_dir = dir ;
pkt->ifp = fwa->oif;
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:
DUMMYNET_UNLOCK();
if (head != NULL)
dummynet_send(head);
return 0;
dropit:
if (q)
q->drops++ ;
DUMMYNET_UNLOCK();
m_freem(m);
return ( (fs && (fs->flags_fs & DN_NOERROR)) ? 0 : ENOBUFS);
}
/*
* Below, the rt_unref 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 { \
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;
DUMMYNET_LOCK_ASSERT();
for (i = 0; i <= fs->rq_size; i++) {
for (q = fs->rq[i]; q != NULL; 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 != NULL)
free(fs->w_q_lookup, M_DUMMYNET);
if (fs->rq != NULL)
free(fs->rq, M_DUMMYNET);
/* If this fs is not part of a pipe, free it. */
if (fs->pipe == NULL || 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. Must also
* remove references from all ipfw rules to all pipes.
*/
static void
dummynet_flush(void)
{
struct dn_pipe *pipe, *pipe1;
struct dn_flow_set *fs, *fs1;
int i;
DUMMYNET_LOCK();
/* 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);
}
DUMMYNET_UNLOCK();
}
extern struct ip_fw *ip_fw_default_rule ;
static void
dn_rule_delete_fs(struct dn_flow_set *fs, void *r)
{
int i ;
struct dn_flow_queue *q ;
struct mbuf *m ;
for (i = 0 ; i <= fs->rq_size ; i++) /* last one is ovflow */
for (q = fs->rq[i] ; q ; q = q->next )
for (m = q->head ; m ; m = m->m_nextpkt ) {
struct dn_pkt_tag *pkt = dn_tag_get(m) ;
if (pkt->rule == r)
pkt->rule = ip_fw_default_rule ;
}
}
/*
* when a firewall rule is deleted, scan all queues and remove the flow-id
* from packets matching this rule.
*/
void
dn_rule_delete(void *r)
{
struct dn_pipe *pipe;
struct dn_flow_set *fs;
struct dn_pkt_tag *pkt;
struct mbuf *m;
int i;
DUMMYNET_LOCK();
/*
* If the rule references a queue (dn_flow_set), then scan
* the flow set, otherwise scan pipes. Should do either, but doing
* both does not harm.
*/
for (i = 0; i < HASHSIZE; i++)
SLIST_FOREACH(fs, &flowsethash[i], next)
dn_rule_delete_fs(fs, r);
for (i = 0; i < HASHSIZE; i++)
SLIST_FOREACH(pipe, &pipehash[i], next) {
fs = &(pipe->fs);
dn_rule_delete_fs(fs, r);
for (m = pipe->head ; m ; m = m->m_nextpkt ) {
pkt = dn_tag_get(m);
if (pkt->rule == r)
pkt->rule = ip_fw_default_rule;
}
}
DUMMYNET_UNLOCK();
}
/*
* 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_NOWAIT);
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_NOWAIT | M_ZERO);
if (x->rq == NULL) {
printf("dummynet: sorry, cannot allocate queue\n");
return (ENOMEM);
}
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)
{
struct dn_flow_set *pfs = &(p->fs);
struct dn_flow_queue *q;
int i, error;
/*
* 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) / 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 *pipe;
DUMMYNET_LOCK();
pipe = locate_pipe(p->pipe_nr); /* locate pipe */
if (pipe == NULL) { /* new pipe */
pipe = malloc(sizeof(struct dn_pipe), M_DUMMYNET,
M_NOWAIT | M_ZERO);
if (pipe == NULL) {
DUMMYNET_UNLOCK();
printf("dummynet: no memory for new pipe\n");
return (ENOMEM);
}
pipe->pipe_nr = p->pipe_nr;
pipe->fs.pipe = pipe;
/*
* idle_heap is the only one from which
* we extract from the middle.
*/
pipe->idle_heap.size = pipe->idle_heap.elements = 0;
pipe->idle_heap.offset =
offsetof(struct dn_flow_queue, heap_pos);
} else
/* Flush accumulated credit for all queues. */
for (i = 0; i <= pipe->fs.rq_size; i++)
for (q = pipe->fs.rq[i]; q; q = q->next)
q->numbytes = 0;
pipe->bandwidth = p->bandwidth;
pipe->numbytes = 0; /* just in case... */
bcopy(p->if_name, pipe->if_name, sizeof(p->if_name));
pipe->ifp = NULL; /* reset interface ptr */
pipe->delay = p->delay;
set_fs_parms(&(pipe->fs), pfs);
if (pipe->fs.rq == NULL) { /* a new pipe */
error = alloc_hash(&(pipe->fs), pfs);
if (error) {
DUMMYNET_UNLOCK();
free(pipe, M_DUMMYNET);
return (error);
}
SLIST_INSERT_HEAD(&pipehash[HASH(pipe->pipe_nr)],
pipe, next);
}
DUMMYNET_UNLOCK();
} else { /* config queue */
struct dn_flow_set *fs;
DUMMYNET_LOCK();
fs = locate_flowset(pfs->fs_nr); /* locate flow_set */
if (fs == NULL) { /* new */
if (pfs->parent_nr == 0) { /* need link to a pipe */
DUMMYNET_UNLOCK();
return (EINVAL);
}
fs = malloc(sizeof(struct dn_flow_set), M_DUMMYNET,
M_NOWAIT | M_ZERO);
if (fs == NULL) {
DUMMYNET_UNLOCK();
printf(
"dummynet: no memory for new flow_set\n");
return (ENOMEM);
}
fs->fs_nr = pfs->fs_nr;
fs->parent_nr = pfs->parent_nr;
fs->weight = pfs->weight;
if (fs->weight == 0)
fs->weight = 1;
else if (fs->weight > 100)
fs->weight = 100;
} else {
/*
* Change parent pipe not allowed;
* must delete and recreate.
*/
if (pfs->parent_nr != 0 &&
fs->parent_nr != pfs->parent_nr) {
DUMMYNET_UNLOCK();
return (EINVAL);
}
}
set_fs_parms(fs, pfs);
if (fs->rq == NULL) { /* a new flow_set */
error = alloc_hash(fs, pfs);
if (error) {
DUMMYNET_UNLOCK();
free(fs, M_DUMMYNET);
return (error);
}
SLIST_INSERT_HEAD(&flowsethash[HASH(fs->fs_nr)],
fs, next);
}
DUMMYNET_UNLOCK();
}
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 *pipe;
struct mbuf *m, *mnext;
int i;
DUMMYNET_LOCK_ASSERT();
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(pipe, &pipehash[i], next) {
purge_flow_set(&(pipe->fs), 0);
mnext = pipe->head;
while ((m = mnext) != NULL) {
mnext = m->m_nextpkt;
DN_FREE_PKT(m);
}
pipe->head = pipe->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 *pipe;
struct dn_flow_set *fs;
int i;
DUMMYNET_LOCK();
pipe = locate_pipe(p->pipe_nr); /* locate pipe */
if (pipe == NULL) {
DUMMYNET_UNLOCK();
return (ENOENT); /* not found */
}
/* Unlink from list of pipes. */
SLIST_REMOVE(&pipehash[HASH(pipe->pipe_nr)], pipe, 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 == pipe) {
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, &(pipe->fs));
purge_pipe(pipe); /* remove all data associated to this pipe */
/* remove reference to here from extract_heap and wfq_ready_heap */
pipe_remove_from_heap(&extract_heap, pipe);
pipe_remove_from_heap(&wfq_ready_heap, pipe);
DUMMYNET_UNLOCK();
free(pipe, M_DUMMYNET);
} else { /* this is a WF2Q queue (dn_flow_set) */
struct dn_flow_set *fs;
DUMMYNET_LOCK();
fs = locate_flowset(p->fs.fs_nr); /* locate set */
if (fs == NULL) {
DUMMYNET_UNLOCK();
return (ENOENT); /* not found */
}
/* Unlink from list of flowsets. */
SLIST_REMOVE( &flowsethash[HASH(fs->fs_nr)], fs, dn_flow_set, next);
if (fs->pipe != NULL) {
/* Update total weight on parent pipe and cleanup parent heaps. */
fs->pipe->sum -= fs->weight * fs->backlogged ;
fs_remove_from_heap(&(fs->pipe->not_eligible_heap), fs);
fs_remove_from_heap(&(fs->pipe->scheduler_heap), fs);
#if 1 /* XXX should i remove from idle_heap as well ? */
fs_remove_from_heap(&(fs->pipe->idle_heap), fs);
#endif
}
purge_flow_set(fs, 1);
DUMMYNET_UNLOCK();
}
return 0 ;
}
/*
* helper function used to copy data from kernel in DUMMYNET_GET
*/
static char *
dn_copy_set(struct dn_flow_set *set, char *bp)
{
int i, copied = 0 ;
struct dn_flow_queue *q, *qp = (struct dn_flow_queue *)bp;
DUMMYNET_LOCK_ASSERT();
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 %p, should be %p)\n",
i, q->fs, set);
copied++ ;
bcopy(q, qp, sizeof( *q ) );
/* cleanup pointers */
qp->next = NULL ;
qp->head = qp->tail = NULL ;
qp->fs = 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(void)
{
struct dn_flow_set *fs;
struct dn_pipe *pipe;
size_t size = 0;
int i;
DUMMYNET_LOCK_ASSERT();
/*
* Compute size of data structures: list of pipes and flow_sets.
*/
for (i = 0; i < HASHSIZE; i++) {
SLIST_FOREACH(pipe, &pipehash[i], next)
size += sizeof(*pipe) +
pipe->fs.rq_elements * sizeof(struct dn_flow_queue);
SLIST_FOREACH(fs, &flowsethash[i], next)
size += sizeof (*fs) +
fs->rq_elements * sizeof(struct dn_flow_queue);
}
return size;
}
static int
dummynet_get(struct sockopt *sopt)
{
char *buf, *bp ; /* bp is the "copy-pointer" */
size_t size ;
struct dn_flow_set *fs;
struct dn_pipe *pipe;
int error=0, i ;
/* XXX lock held too long */
DUMMYNET_LOCK();
/*
* XXX: Ugly, but we need to allocate memory with M_WAITOK flag and we
* cannot use this flag while holding a mutex.
*/
for (i = 0; i < 10; i++) {
size = dn_calc_size();
DUMMYNET_UNLOCK();
buf = malloc(size, M_TEMP, M_WAITOK);
DUMMYNET_LOCK();
if (size == dn_calc_size())
break;
free(buf, M_TEMP);
buf = NULL;
}
if (buf == NULL) {
DUMMYNET_UNLOCK();
return ENOBUFS ;
}
bp = buf;
for (i = 0; i < HASHSIZE; i++)
SLIST_FOREACH(pipe, &pipehash[i], next) {
struct dn_pipe *pipe_bp = (struct dn_pipe *)bp;
/*
* 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.
*/
bcopy(pipe, bp, sizeof(*pipe));
pipe_bp->delay = (pipe_bp->delay * 1000) / hz;
/*
* 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.sle_next = (struct dn_pipe *)DN_IS_PIPE;
/* Clean pointers. */
pipe_bp->head = pipe_bp->tail = NULL;
pipe_bp->fs.next.sle_next = NULL;
pipe_bp->fs.pipe = NULL;
pipe_bp->fs.rq = NULL;
bp += sizeof(*pipe) ;
bp = dn_copy_set(&(pipe->fs), bp);
}
for (i = 0; i < HASHSIZE; i++)
SLIST_FOREACH(fs, &flowsethash[i], next) {
struct dn_flow_set *fs_bp = (struct dn_flow_set *)bp;
bcopy(fs, bp, sizeof(*fs));
/* XXX same hack as above */
fs_bp->next.sle_next = (struct dn_flow_set *)DN_IS_QUEUE;
fs_bp->pipe = NULL;
fs_bp->rq = NULL;
bp += sizeof(*fs);
bp = dn_copy_set(fs, bp);
}
DUMMYNET_UNLOCK();
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) {
#if __FreeBSD_version >= 500034
error = securelevel_ge(sopt->sopt_td->td_ucred, 3);
if (error)
return (error);
#else
if (securelevel >= 3)
return (EPERM);
#endif
}
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 ;
error = sooptcopyin(sopt, p, sizeof *p, sizeof *p);
if (error)
break ;
error = config_pipe(p);
break ;
case IP_DUMMYNET_DEL : /* remove a pipe or queue */
p = &tmp_pipe ;
error = sooptcopyin(sopt, p, sizeof *p, sizeof *p);
if (error)
break ;
error = delete_pipe(p);
break ;
}
return error ;
}
static void
ip_dn_init(void)
{
int i;
if (bootverbose)
printf("DUMMYNET with IPv6 initialized (040826)\n");
DUMMYNET_LOCK_INIT();
for (i = 0; i < HASHSIZE; i++) {
SLIST_INIT(&pipehash[i]);
SLIST_INIT(&flowsethash[i]);
}
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;
ip_dn_ruledel_ptr = dn_rule_delete;
TASK_INIT(&dn_task, 0, dummynet_task, NULL);
dn_tq = taskqueue_create_fast("dummynet", M_NOWAIT,
taskqueue_thread_enqueue, &dn_tq);
taskqueue_start_threads(&dn_tq, 1, PI_NET, "dummynet");
callout_init(&dn_timeout, NET_CALLOUT_MPSAFE);
callout_reset(&dn_timeout, 1, dummynet, NULL);
/* Initialize curr_time adjustment mechanics. */
getmicrouptime(&prev_t);
}
#ifdef KLD_MODULE
static void
ip_dn_destroy(void)
{
ip_dn_ctl_ptr = NULL;
ip_dn_io_ptr = NULL;
ip_dn_ruledel_ptr = NULL;
DUMMYNET_LOCK();
callout_stop(&dn_timeout);
DUMMYNET_UNLOCK();
taskqueue_drain(dn_tq, &dn_task);
taskqueue_free(dn_tq);
dummynet_flush();
DUMMYNET_LOCK_DESTROY();
}
#endif /* KLD_MODULE */
static int
dummynet_modevent(module_t mod, int type, void *data)
{
switch (type) {
case MOD_LOAD:
if (DUMMYNET_LOADED) {
printf("DUMMYNET already loaded\n");
return EEXIST ;
}
ip_dn_init();
break;
case MOD_UNLOAD:
#if !defined(KLD_MODULE)
printf("dummynet statically compiled, cannot unload\n");
return EINVAL ;
#else
ip_dn_destroy();
#endif
break ;
default:
return EOPNOTSUPP;
break ;
}
return 0 ;
}
static moduledata_t dummynet_mod = {
"dummynet",
dummynet_modevent,
NULL
};
DECLARE_MODULE(dummynet, dummynet_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY);
MODULE_DEPEND(dummynet, ipfw, 2, 2, 2);
MODULE_VERSION(dummynet, 1);