362 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			362 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * Copyright (c) 1998-2002 Luigi Rizzo, Universita` di Pisa
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|  * Portions Copyright (c) 2000 Akamba Corp.
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|  * All rights reserved
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  * 1. Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  * 2. Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in the
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|  *    documentation and/or other materials provided with the distribution.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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|  * SUCH DAMAGE.
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|  *
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|  * $FreeBSD: src/sys/netinet/ip_dummynet.h,v 1.18 2002/05/05 21:27:47 luigi Exp $
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|  */
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| 
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| #ifndef _IP_DUMMYNET_H
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| #define _IP_DUMMYNET_H
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| 
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| /*
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|  * Definition of dummynet data structures. In the structures, I decided
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|  * not to use the macros in <sys/queue.h> in the hope of making the code
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|  * easier to port to other architectures. The type of lists and queue we
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|  * use here is pretty simple anyways.
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|  */
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| 
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| /*
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|  * We start with a heap, which is used in the scheduler to decide when
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|  * to transmit packets etc.
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|  *
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|  * The key for the heap is used for two different values:
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|  *
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|  * 1. timer ticks- max 10K/second, so 32 bits are enough;
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|  *
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|  * 2. virtual times. These increase in steps of len/x, where len is the
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|  *    packet length, and x is either the weight of the flow, or the
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|  *    sum of all weights.
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|  *    If we limit to max 1000 flows and a max weight of 100, then
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|  *    x needs 17 bits. The packet size is 16 bits, so we can easily
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|  *    overflow if we do not allow errors.
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|  * So we use a key "dn_key" which is 64 bits. Some macros are used to
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|  * compare key values and handle wraparounds.
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|  * MAX64 returns the largest of two key values.
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|  * MY_M is used as a shift count when doing fixed point arithmetic
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|  * (a better name would be useful...).
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|  */
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| typedef u_int64_t dn_key ;      /* sorting key */
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| #define DN_KEY_LT(a,b)     ((int64_t)((a)-(b)) < 0)
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| #define DN_KEY_LEQ(a,b)    ((int64_t)((a)-(b)) <= 0)
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| #define DN_KEY_GT(a,b)     ((int64_t)((a)-(b)) > 0)
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| #define DN_KEY_GEQ(a,b)    ((int64_t)((a)-(b)) >= 0)
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| #define MAX64(x,y)  (( (int64_t) ( (y)-(x) )) > 0 ) ? (y) : (x)
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| #define MY_M	16 /* number of left shift to obtain a larger precision */
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| 
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| /*
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|  * XXX With this scaling, max 1000 flows, max weight 100, 1Gbit/s, the
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|  * virtual time wraps every 15 days.
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|  */
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| 
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| /*
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|  * The OFFSET_OF macro is used to return the offset of a field within
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|  * a structure. It is used by the heap management routines.
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|  */
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| #define OFFSET_OF(type, field) ((int)&( ((type *)0)->field) )
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| 
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| /*
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|  * A heap entry is made of a key and a pointer to the actual
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|  * object stored in the heap.
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|  * The heap is an array of dn_heap_entry entries, dynamically allocated.
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|  * Current size is "size", with "elements" actually in use.
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|  * The heap normally supports only ordered insert and extract from the top.
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|  * If we want to extract an object from the middle of the heap, we
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|  * have to know where the object itself is located in the heap (or we
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|  * need to scan the whole array). To this purpose, an object has a
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|  * field (int) which contains the index of the object itself into the
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|  * heap. When the object is moved, the field must also be updated.
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|  * The offset of the index in the object is stored in the 'offset'
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|  * field in the heap descriptor. The assumption is that this offset
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|  * is non-zero if we want to support extract from the middle.
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|  */
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| struct dn_heap_entry {
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|     dn_key key ;	/* sorting key. Topmost element is smallest one */
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|     void *object ;	/* object pointer */
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| } ;
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| 
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| struct dn_heap {
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|     int size ;
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|     int elements ;
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|     int offset ; /* XXX if > 0 this is the offset of direct ptr to obj */
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|     struct dn_heap_entry *p ;	/* really an array of "size" entries */
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| } ;
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| 
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| /*
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|  * MT_DUMMYNET is a new (fake) mbuf type that is prepended to the
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|  * packet when it comes out of a pipe. The definition
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|  * ought to go in /sys/sys/mbuf.h but here it is less intrusive.
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|  */
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| 
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| #define MT_DUMMYNET MT_CONTROL
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| 
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| /*
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|  * struct dn_pkt identifies a packet in the dummynet queue. The
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|  * first part is really an m_hdr for implementation purposes, and some
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|  * fields are saved there. When passing the packet back to the ip_input/
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|  * ip_output()/bdg_forward, the struct is prepended to the mbuf chain with type
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|  * MT_DUMMYNET, and contains the pointer to the matching rule.
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|  *
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|  * Note: there is no real need to make this structure contain an m_hdr,
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|  * in the future this should be changed to a normal data structure.
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|  */
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| struct dn_pkt {
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|     struct m_hdr hdr ;
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| #define dn_next	hdr.mh_nextpkt	/* next element in queue */
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| #define DN_NEXT(x)	(struct dn_pkt *)(x)->dn_next
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| #define dn_m	hdr.mh_next	/* packet to be forwarded */
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| #define dn_dir	hdr.mh_flags	/* action when pkt extracted from a queue */
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| #define DN_TO_IP_OUT	1
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| #define DN_TO_IP_IN	2
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| #define DN_TO_BDG_FWD	3
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| 
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|     dn_key  output_time;	/* when the pkt is due for delivery	*/
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|     struct ifnet *ifp;		/* interface, for ip_output		*/
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|     struct sockaddr_in *dn_dst ;
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|     struct route ro;		/* route, for ip_output. MUST COPY	*/
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|     int flags ;			/* flags, for ip_output (IPv6 ?)	*/
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| };
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| 
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| /*
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|  * Overall structure of dummynet (with WF2Q+):
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| 
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| In dummynet, packets are selected with the firewall rules, and passed
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| to two different objects: PIPE or QUEUE.
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| 
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| A QUEUE is just a queue with configurable size and queue management
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| policy. It is also associated with a mask (to discriminate among
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| different flows), a weight (used to give different shares of the
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| bandwidth to different flows) and a "pipe", which essentially
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| supplies the transmit clock for all queues associated with that
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| pipe.
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| 
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| A PIPE emulates a fixed-bandwidth link, whose bandwidth is
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| configurable.  The "clock" for a pipe can come from either an
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| internal timer, or from the transmit interrupt of an interface.
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| A pipe is also associated with one (or more, if masks are used)
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| queue, where all packets for that pipe are stored.
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| 
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| The bandwidth available on the pipe is shared by the queues
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| associated with that pipe (only one in case the packet is sent
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| to a PIPE) according to the WF2Q+ scheduling algorithm and the
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| configured weights.
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| 
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| In general, incoming packets are stored in the appropriate queue,
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| which is then placed into one of a few heaps managed by a scheduler
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| to decide when the packet should be extracted.
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| The scheduler (a function called dummynet()) is run at every timer
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| tick, and grabs queues from the head of the heaps when they are
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| ready for processing.
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| 
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| There are three data structures definining a pipe and associated queues:
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| 
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|  + dn_pipe, which contains the main configuration parameters related
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|    to delay and bandwidth;
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|  + dn_flow_set, which contains WF2Q+ configuration, flow
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|    masks, plr and RED configuration;
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|  + dn_flow_queue, which is the per-flow queue (containing the packets)
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| 
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| Multiple dn_flow_set can be linked to the same pipe, and multiple
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| dn_flow_queue can be linked to the same dn_flow_set.
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| All data structures are linked in a linear list which is used for
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| housekeeping purposes.
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| 
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| During configuration, we create and initialize the dn_flow_set
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| and dn_pipe structures (a dn_pipe also contains a dn_flow_set).
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| 
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| At runtime: packets are sent to the appropriate dn_flow_set (either
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| WFQ ones, or the one embedded in the dn_pipe for fixed-rate flows),
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| which in turn dispatches them to the appropriate dn_flow_queue
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| (created dynamically according to the masks).
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| 
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| The transmit clock for fixed rate flows (ready_event()) selects the
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| dn_flow_queue to be used to transmit the next packet. For WF2Q,
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| wfq_ready_event() extract a pipe which in turn selects the right
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| flow using a number of heaps defined into the pipe itself.
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| 
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|  *
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|  */
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| 
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| /*
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|  * per flow queue. This contains the flow identifier, the queue
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|  * of packets, counters, and parameters used to support both RED and
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|  * WF2Q+.
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|  *
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|  * A dn_flow_queue is created and initialized whenever a packet for
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|  * a new flow arrives.
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|  */
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| struct dn_flow_queue {
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|     struct dn_flow_queue *next ;
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|     struct ipfw_flow_id id ;
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| 
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|     struct dn_pkt *head, *tail ;	/* queue of packets */
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|     u_int len ;
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|     u_int len_bytes ;
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|     long numbytes ;		/* credit for transmission (dynamic queues) */
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| 
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|     u_int64_t tot_pkts ;	/* statistics counters	*/
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|     u_int64_t tot_bytes ;
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|     u_int32_t drops ;
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| 
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|     int hash_slot ;		/* debugging/diagnostic */
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| 
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|     /* RED parameters */
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|     int avg ;                   /* average queue length est. (scaled) */
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|     int count ;                 /* arrivals since last RED drop */
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|     int random ;                /* random value (scaled) */
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|     u_int32_t q_time ;          /* start of queue idle time */
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| 
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|     /* WF2Q+ support */
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|     struct dn_flow_set *fs ;	/* parent flow set */
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|     int heap_pos ;		/* position (index) of struct in heap */
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|     dn_key sched_time ;		/* current time when queue enters ready_heap */
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| 
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|     dn_key S,F ;		/* start time, finish time */
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|     /*
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|      * Setting F < S means the timestamp is invalid. We only need
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|      * to test this when the queue is empty.
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|      */
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| } ;
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| 
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| /*
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|  * flow_set descriptor. Contains the "template" parameters for the
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|  * queue configuration, and pointers to the hash table of dn_flow_queue's.
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|  *
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|  * The hash table is an array of lists -- we identify the slot by
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|  * hashing the flow-id, then scan the list looking for a match.
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|  * The size of the hash table (buckets) is configurable on a per-queue
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|  * basis.
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|  *
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|  * A dn_flow_set is created whenever a new queue or pipe is created (in the
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|  * latter case, the structure is located inside the struct dn_pipe).
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|  */
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| struct dn_flow_set {
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|     struct dn_flow_set *next; /* next flow set in all_flow_sets list */
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| 
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|     u_short fs_nr ;             /* flow_set number       */
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|     u_short flags_fs;
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| #define DN_HAVE_FLOW_MASK	0x0001
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| #define DN_IS_RED		0x0002
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| #define DN_IS_GENTLE_RED	0x0004
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| #define DN_QSIZE_IS_BYTES	0x0008	/* queue size is measured in bytes */
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| #define DN_IS_PIPE		0x4000
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| #define DN_IS_QUEUE		0x8000
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| 
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|     struct dn_pipe *pipe ;	/* pointer to parent pipe */
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|     u_short parent_nr ;		/* parent pipe#, 0 if local to a pipe */
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| 
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|     int weight ;		/* WFQ queue weight */
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|     int qsize ;			/* queue size in slots or bytes */
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|     int plr ;			/* pkt loss rate (2^31-1 means 100%) */
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| 
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|     struct ipfw_flow_id flow_mask ;
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| 
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|     /* hash table of queues onto this flow_set */
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|     int rq_size ;		/* number of slots */
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|     int rq_elements ;		/* active elements */
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|     struct dn_flow_queue **rq;	/* array of rq_size entries */
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| 
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|     u_int32_t last_expired ;	/* do not expire too frequently */
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|     int backlogged ;		/* #active queues for this flowset */
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| 
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|         /* RED parameters */
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| #define SCALE_RED               16
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| #define SCALE(x)                ( (x) << SCALE_RED )
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| #define SCALE_VAL(x)            ( (x) >> SCALE_RED )
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| #define SCALE_MUL(x,y)          ( ( (x) * (y) ) >> SCALE_RED )
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|     int w_q ;			/* queue weight (scaled) */
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|     int max_th ;		/* maximum threshold for queue (scaled) */
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|     int min_th ;		/* minimum threshold for queue (scaled) */
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|     int max_p ;			/* maximum value for p_b (scaled) */
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|     u_int c_1 ;			/* max_p/(max_th-min_th) (scaled) */
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|     u_int c_2 ;			/* max_p*min_th/(max_th-min_th) (scaled) */
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|     u_int c_3 ;			/* for GRED, (1-max_p)/max_th (scaled) */
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|     u_int c_4 ;			/* for GRED, 1 - 2*max_p (scaled) */
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|     u_int * w_q_lookup ;	/* lookup table for computing (1-w_q)^t */
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|     u_int lookup_depth ;	/* depth of lookup table */
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|     int lookup_step ;		/* granularity inside the lookup table */
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|     int lookup_weight ;		/* equal to (1-w_q)^t / (1-w_q)^(t+1) */
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|     int avg_pkt_size ;		/* medium packet size */
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|     int max_pkt_size ;		/* max packet size */
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| } ;
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| 
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| /*
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|  * Pipe descriptor. Contains global parameters, delay-line queue,
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|  * and the flow_set used for fixed-rate queues.
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|  * 
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|  * For WF2Q+ support it also has 3 heaps holding dn_flow_queue:
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|  *   not_eligible_heap, for queues whose start time is higher
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|  *	than the virtual time. Sorted by start time.
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|  *   scheduler_heap, for queues eligible for scheduling. Sorted by
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|  *	finish time.
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|  *   idle_heap, all flows that are idle and can be removed. We
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|  *	do that on each tick so we do not slow down too much
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|  *	operations during forwarding.
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|  * 
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|  */
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| struct dn_pipe {		/* a pipe */
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|     struct dn_pipe *next ;
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| 
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|     int	pipe_nr ;		/* number	*/
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|     int bandwidth;		/* really, bytes/tick.	*/
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|     int	delay ;			/* really, ticks	*/
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| 
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|     struct	dn_pkt *head, *tail ;	/* packets in delay line */
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| 
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|     /* WF2Q+ */
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|     struct dn_heap scheduler_heap ; /* top extract - key Finish time*/
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|     struct dn_heap not_eligible_heap; /* top extract- key Start time */
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|     struct dn_heap idle_heap ; /* random extract - key Start=Finish time */
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| 
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|     dn_key V ;			/* virtual time */
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|     int sum;			/* sum of weights of all active sessions */
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|     int numbytes;		/* bits I can transmit (more or less). */
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| 
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|     dn_key sched_time ;		/* time pipe was scheduled in ready_heap */
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| 
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|     /*
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|      * When the tx clock come from an interface (if_name[0] != '\0'), its name
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|      * is stored below, whereas the ifp is filled when the rule is configured.
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|      */
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|     char if_name[16];
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|     struct ifnet *ifp ;
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|     int ready ; /* set if ifp != NULL and we got a signal from it */
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| 
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|     struct dn_flow_set fs ; /* used with fixed-rate flows */
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| };
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| 
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| #ifdef _KERNEL
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| typedef	int ip_dn_ctl_t(struct sockopt *); /* raw_ip.c */
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| typedef	void ip_dn_ruledel_t(void *); /* ip_fw.c */
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| typedef	int ip_dn_io_t(int pipe, int dir, struct mbuf *m,
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| 	struct ifnet *ifp, struct route *ro, struct sockaddr_in * dst,
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| 	struct ip_fw *rule, int flags); /* ip_{in,out}put.c, bridge.c */
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| extern	ip_dn_ctl_t *ip_dn_ctl_ptr;
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| extern	ip_dn_ruledel_t *ip_dn_ruledel_ptr;
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| extern	ip_dn_io_t *ip_dn_io_ptr;
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| #define	DUMMYNET_LOADED	(ip_dn_io_ptr != NULL)
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| #endif
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| 
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| #endif /* _IP_DUMMYNET_H */
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