652 lines
15 KiB
C
652 lines
15 KiB
C
/*
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* Simple traffic shaper for Linux NET3.
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*
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* (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
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* http://www.redhat.com
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
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* warranty for any of this software. This material is provided
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* "AS-IS" and at no charge.
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*
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*
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* Algorithm:
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*
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* Queue Frame:
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* Compute time length of frame at regulated speed
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* Add frame to queue at appropriate point
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* Adjust time length computation for followup frames
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* Any frame that falls outside of its boundaries is freed
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*
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* We work to the following constants
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*
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* SHAPER_QLEN Maximum queued frames
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* SHAPER_LATENCY Bounding latency on a frame. Leaving this latency
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* window drops the frame. This stops us queueing
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* frames for a long time and confusing a remote
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* host.
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* SHAPER_MAXSLIP Maximum time a priority frame may jump forward.
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* That bounds the penalty we will inflict on low
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* priority traffic.
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* SHAPER_BURST Time range we call "now" in order to reduce
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* system load. The more we make this the burstier
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* the behaviour, the better local performance you
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* get through packet clustering on routers and the
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* worse the remote end gets to judge rtts.
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*
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* This is designed to handle lower speed links ( < 200K/second or so). We
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* run off a 100-150Hz base clock typically. This gives us a resolution at
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* 200Kbit/second of about 2Kbit or 256 bytes. Above that our timer
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* resolution may start to cause much more burstiness in the traffic. We
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* could avoid a lot of that by calling kick_shaper() at the end of the
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* tied device transmissions. If you run above about 100K second you
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* may need to tune the supposed speed rate for the right values.
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*
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* BUGS:
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* Downing the interface under the shaper before the shaper
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* will render your machine defunct. Don't for now shape over
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* PPP or SLIP therefore!
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* This will be fixed in BETA4
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*
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* Update History :
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*
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* bh_atomic() SMP races fixes and rewritten the locking code to
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* be SMP safe and irq-mask friendly.
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* NOTE: we can't use start_bh_atomic() in kick_shaper()
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* because it's going to be recalled from an irq handler,
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* and synchronize_bh() is a nono if called from irq context.
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* 1999 Andrea Arcangeli
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*
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* Device statistics (tx_pakets, tx_bytes,
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* tx_drops: queue_over_time and collisions: max_queue_exceded)
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* 1999/06/18 Jordi Murgo <savage@apostols.org>
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*
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* Use skb->cb for private data.
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* 2000/03 Andi Kleen
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/fcntl.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/netdevice.h>
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#include <linux/etherdevice.h>
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#include <linux/skbuff.h>
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#include <linux/if_arp.h>
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#include <linux/init.h>
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#include <linux/if_shaper.h>
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#include <net/dst.h>
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#include <net/arp.h>
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struct shaper_cb {
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unsigned long shapeclock; /* Time it should go out */
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unsigned long shapestamp; /* Stamp for shaper */
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__u32 shapelatency; /* Latency on frame */
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__u32 shapelen; /* Frame length in clocks */
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__u16 shapepend; /* Pending */
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};
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#define SHAPERCB(skb) ((struct shaper_cb *) ((skb)->cb))
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static int sh_debug; /* Debug flag */
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#define SHAPER_BANNER "CymruNet Traffic Shaper BETA 0.04 for Linux 2.1\n"
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static void shaper_kick(struct shaper *sh);
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/*
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* Compute clocks on a buffer
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*/
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static int shaper_clocks(struct shaper *shaper, struct sk_buff *skb)
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{
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int t=skb->len/shaper->bytespertick;
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return t;
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}
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/*
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* Set the speed of a shaper. We compute this in bytes per tick since
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* thats how the machine wants to run. Quoted input is in bits per second
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* as is traditional (note not BAUD). We assume 8 bit bytes.
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*/
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static void shaper_setspeed(struct shaper *shaper, int bitspersec)
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{
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shaper->bitspersec=bitspersec;
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shaper->bytespertick=(bitspersec/HZ)/8;
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if(!shaper->bytespertick)
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shaper->bytespertick++;
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}
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/*
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* Throw a frame at a shaper.
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*/
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static int shaper_start_xmit(struct sk_buff *skb, struct net_device *dev)
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{
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struct shaper *shaper = dev->priv;
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struct sk_buff *ptr;
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spin_lock(&shaper->lock);
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ptr=shaper->sendq.prev;
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/*
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* Set up our packet details
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*/
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SHAPERCB(skb)->shapelatency=0;
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SHAPERCB(skb)->shapeclock=shaper->recovery;
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if(time_before(SHAPERCB(skb)->shapeclock, jiffies))
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SHAPERCB(skb)->shapeclock=jiffies;
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skb->priority=0; /* short term bug fix */
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SHAPERCB(skb)->shapestamp=jiffies;
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/*
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* Time slots for this packet.
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*/
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SHAPERCB(skb)->shapelen= shaper_clocks(shaper,skb);
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{
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struct sk_buff *tmp;
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/*
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* Up our shape clock by the time pending on the queue
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* (Should keep this in the shaper as a variable..)
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*/
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for(tmp=skb_peek(&shaper->sendq); tmp!=NULL &&
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tmp!=(struct sk_buff *)&shaper->sendq; tmp=tmp->next)
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SHAPERCB(skb)->shapeclock+=SHAPERCB(tmp)->shapelen;
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/*
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* Queue over time. Spill packet.
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*/
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if(SHAPERCB(skb)->shapeclock-jiffies > SHAPER_LATENCY) {
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dev_kfree_skb(skb);
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shaper->stats.tx_dropped++;
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} else
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skb_queue_tail(&shaper->sendq, skb);
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}
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if(sh_debug)
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printk("Frame queued.\n");
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if(skb_queue_len(&shaper->sendq)>SHAPER_QLEN)
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{
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ptr=skb_dequeue(&shaper->sendq);
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dev_kfree_skb(ptr);
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shaper->stats.collisions++;
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}
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shaper_kick(shaper);
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spin_unlock(&shaper->lock);
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return 0;
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}
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/*
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* Transmit from a shaper
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*/
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static void shaper_queue_xmit(struct shaper *shaper, struct sk_buff *skb)
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{
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struct sk_buff *newskb=skb_clone(skb, GFP_ATOMIC);
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if(sh_debug)
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printk("Kick frame on %p\n",newskb);
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if(newskb)
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{
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newskb->dev=shaper->dev;
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newskb->priority=2;
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if(sh_debug)
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printk("Kick new frame to %s, %d\n",
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shaper->dev->name,newskb->priority);
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dev_queue_xmit(newskb);
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shaper->stats.tx_bytes += skb->len;
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shaper->stats.tx_packets++;
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if(sh_debug)
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printk("Kicked new frame out.\n");
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dev_kfree_skb(skb);
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}
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}
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/*
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* Timer handler for shaping clock
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*/
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static void shaper_timer(unsigned long data)
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{
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struct shaper *shaper = (struct shaper *)data;
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spin_lock(&shaper->lock);
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shaper_kick(shaper);
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spin_unlock(&shaper->lock);
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}
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/*
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* Kick a shaper queue and try and do something sensible with the
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* queue.
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*/
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static void shaper_kick(struct shaper *shaper)
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{
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struct sk_buff *skb;
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/*
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* Walk the list (may be empty)
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*/
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while((skb=skb_peek(&shaper->sendq))!=NULL)
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{
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/*
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* Each packet due to go out by now (within an error
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* of SHAPER_BURST) gets kicked onto the link
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*/
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if(sh_debug)
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printk("Clock = %ld, jiffies = %ld\n", SHAPERCB(skb)->shapeclock, jiffies);
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if(time_before_eq(SHAPERCB(skb)->shapeclock, jiffies + SHAPER_BURST))
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{
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/*
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* Pull the frame and get interrupts back on.
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*/
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skb_unlink(skb, &shaper->sendq);
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if (shaper->recovery <
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SHAPERCB(skb)->shapeclock + SHAPERCB(skb)->shapelen)
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shaper->recovery = SHAPERCB(skb)->shapeclock + SHAPERCB(skb)->shapelen;
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/*
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* Pass on to the physical target device via
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* our low level packet thrower.
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*/
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SHAPERCB(skb)->shapepend=0;
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shaper_queue_xmit(shaper, skb); /* Fire */
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}
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else
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break;
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}
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/*
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* Next kick.
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*/
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if(skb!=NULL)
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mod_timer(&shaper->timer, SHAPERCB(skb)->shapeclock);
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}
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/*
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* Bring the interface up. We just disallow this until a
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* bind.
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*/
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static int shaper_open(struct net_device *dev)
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{
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struct shaper *shaper=dev->priv;
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/*
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* Can't open until attached.
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* Also can't open until speed is set, or we'll get
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* a division by zero.
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*/
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if(shaper->dev==NULL)
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return -ENODEV;
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if(shaper->bitspersec==0)
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return -EINVAL;
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return 0;
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}
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/*
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* Closing a shaper flushes the queues.
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*/
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static int shaper_close(struct net_device *dev)
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{
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struct shaper *shaper=dev->priv;
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struct sk_buff *skb;
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while ((skb = skb_dequeue(&shaper->sendq)) != NULL)
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dev_kfree_skb(skb);
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spin_lock_bh(&shaper->lock);
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shaper_kick(shaper);
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spin_unlock_bh(&shaper->lock);
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del_timer_sync(&shaper->timer);
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return 0;
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}
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/*
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* Revectored calls. We alter the parameters and call the functions
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* for our attached device. This enables us to bandwidth allocate after
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* ARP and other resolutions and not before.
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*/
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static struct net_device_stats *shaper_get_stats(struct net_device *dev)
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{
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struct shaper *sh=dev->priv;
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return &sh->stats;
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}
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static int shaper_header(struct sk_buff *skb, struct net_device *dev,
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unsigned short type, void *daddr, void *saddr, unsigned len)
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{
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struct shaper *sh=dev->priv;
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int v;
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if(sh_debug)
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printk("Shaper header\n");
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skb->dev=sh->dev;
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v=sh->hard_header(skb,sh->dev,type,daddr,saddr,len);
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skb->dev=dev;
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return v;
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}
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static int shaper_rebuild_header(struct sk_buff *skb)
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{
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struct shaper *sh=skb->dev->priv;
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struct net_device *dev=skb->dev;
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int v;
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if(sh_debug)
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printk("Shaper rebuild header\n");
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skb->dev=sh->dev;
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v=sh->rebuild_header(skb);
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skb->dev=dev;
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return v;
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}
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#if 0
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static int shaper_cache(struct neighbour *neigh, struct hh_cache *hh)
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{
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struct shaper *sh=neigh->dev->priv;
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struct net_device *tmp;
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int ret;
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if(sh_debug)
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printk("Shaper header cache bind\n");
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tmp=neigh->dev;
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neigh->dev=sh->dev;
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ret=sh->hard_header_cache(neigh,hh);
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neigh->dev=tmp;
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return ret;
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}
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static void shaper_cache_update(struct hh_cache *hh, struct net_device *dev,
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unsigned char *haddr)
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{
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struct shaper *sh=dev->priv;
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if(sh_debug)
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printk("Shaper cache update\n");
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sh->header_cache_update(hh, sh->dev, haddr);
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}
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#endif
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#ifdef CONFIG_INET
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static int shaper_neigh_setup(struct neighbour *n)
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{
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#ifdef CONFIG_INET
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if (n->nud_state == NUD_NONE) {
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n->ops = &arp_broken_ops;
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n->output = n->ops->output;
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}
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#endif
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return 0;
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}
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static int shaper_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
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{
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#ifdef CONFIG_INET
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if (p->tbl->family == AF_INET) {
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p->neigh_setup = shaper_neigh_setup;
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p->ucast_probes = 0;
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p->mcast_probes = 0;
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}
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#endif
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return 0;
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}
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#else /* !(CONFIG_INET) */
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static int shaper_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
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{
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return 0;
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}
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#endif
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static int shaper_attach(struct net_device *shdev, struct shaper *sh, struct net_device *dev)
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{
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sh->dev = dev;
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sh->hard_start_xmit=dev->hard_start_xmit;
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sh->get_stats=dev->get_stats;
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if(dev->hard_header)
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{
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sh->hard_header=dev->hard_header;
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shdev->hard_header = shaper_header;
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}
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else
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shdev->hard_header = NULL;
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if(dev->rebuild_header)
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{
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sh->rebuild_header = dev->rebuild_header;
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shdev->rebuild_header = shaper_rebuild_header;
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}
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else
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shdev->rebuild_header = NULL;
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#if 0
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if(dev->hard_header_cache)
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{
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sh->hard_header_cache = dev->hard_header_cache;
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shdev->hard_header_cache= shaper_cache;
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}
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else
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{
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shdev->hard_header_cache= NULL;
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}
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if(dev->header_cache_update)
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{
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sh->header_cache_update = dev->header_cache_update;
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shdev->header_cache_update = shaper_cache_update;
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}
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else
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shdev->header_cache_update= NULL;
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#else
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shdev->header_cache_update = NULL;
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shdev->hard_header_cache = NULL;
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#endif
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shdev->neigh_setup = shaper_neigh_setup_dev;
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shdev->hard_header_len=dev->hard_header_len;
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shdev->type=dev->type;
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shdev->addr_len=dev->addr_len;
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shdev->mtu=dev->mtu;
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sh->bitspersec=0;
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return 0;
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}
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static int shaper_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
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{
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struct shaperconf *ss= (struct shaperconf *)&ifr->ifr_ifru;
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struct shaper *sh=dev->priv;
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if(ss->ss_cmd == SHAPER_SET_DEV || ss->ss_cmd == SHAPER_SET_SPEED)
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{
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if(!capable(CAP_NET_ADMIN))
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return -EPERM;
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}
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switch(ss->ss_cmd)
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{
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case SHAPER_SET_DEV:
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{
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struct net_device *them=__dev_get_by_name(ss->ss_name);
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if(them==NULL)
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return -ENODEV;
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if(sh->dev)
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return -EBUSY;
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return shaper_attach(dev,dev->priv, them);
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}
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case SHAPER_GET_DEV:
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if(sh->dev==NULL)
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return -ENODEV;
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strcpy(ss->ss_name, sh->dev->name);
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return 0;
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case SHAPER_SET_SPEED:
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shaper_setspeed(sh,ss->ss_speed);
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return 0;
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case SHAPER_GET_SPEED:
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ss->ss_speed=sh->bitspersec;
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return 0;
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default:
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return -EINVAL;
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}
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}
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static void shaper_init_priv(struct net_device *dev)
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{
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struct shaper *sh = dev->priv;
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skb_queue_head_init(&sh->sendq);
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init_timer(&sh->timer);
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sh->timer.function=shaper_timer;
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sh->timer.data=(unsigned long)sh;
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spin_lock_init(&sh->lock);
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}
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/*
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* Add a shaper device to the system
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*/
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static void __init shaper_setup(struct net_device *dev)
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{
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/*
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* Set up the shaper.
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*/
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SET_MODULE_OWNER(dev);
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shaper_init_priv(dev);
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dev->open = shaper_open;
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dev->stop = shaper_close;
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dev->hard_start_xmit = shaper_start_xmit;
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dev->get_stats = shaper_get_stats;
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dev->set_multicast_list = NULL;
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/*
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* Intialise the packet queues
|
|
*/
|
|
|
|
/*
|
|
* Handlers for when we attach to a device.
|
|
*/
|
|
|
|
dev->hard_header = shaper_header;
|
|
dev->rebuild_header = shaper_rebuild_header;
|
|
#if 0
|
|
dev->hard_header_cache = shaper_cache;
|
|
dev->header_cache_update= shaper_cache_update;
|
|
#endif
|
|
dev->neigh_setup = shaper_neigh_setup_dev;
|
|
dev->do_ioctl = shaper_ioctl;
|
|
dev->hard_header_len = 0;
|
|
dev->type = ARPHRD_ETHER; /* initially */
|
|
dev->set_mac_address = NULL;
|
|
dev->mtu = 1500;
|
|
dev->addr_len = 0;
|
|
dev->tx_queue_len = 10;
|
|
dev->flags = 0;
|
|
}
|
|
|
|
static int shapers = 1;
|
|
#ifdef MODULE
|
|
|
|
module_param(shapers, int, 0);
|
|
MODULE_PARM_DESC(shapers, "Traffic shaper: maximum number of shapers");
|
|
|
|
#else /* MODULE */
|
|
|
|
static int __init set_num_shapers(char *str)
|
|
{
|
|
shapers = simple_strtol(str, NULL, 0);
|
|
return 1;
|
|
}
|
|
|
|
__setup("shapers=", set_num_shapers);
|
|
|
|
#endif /* MODULE */
|
|
|
|
static struct net_device **devs;
|
|
|
|
static unsigned int shapers_registered = 0;
|
|
|
|
static int __init shaper_init(void)
|
|
{
|
|
int i;
|
|
size_t alloc_size;
|
|
struct net_device *dev;
|
|
char name[IFNAMSIZ];
|
|
|
|
if (shapers < 1)
|
|
return -ENODEV;
|
|
|
|
alloc_size = sizeof(*dev) * shapers;
|
|
devs = kmalloc(alloc_size, GFP_KERNEL);
|
|
if (!devs)
|
|
return -ENOMEM;
|
|
memset(devs, 0, alloc_size);
|
|
|
|
for (i = 0; i < shapers; i++) {
|
|
|
|
snprintf(name, IFNAMSIZ, "shaper%d", i);
|
|
dev = alloc_netdev(sizeof(struct shaper), name,
|
|
shaper_setup);
|
|
if (!dev)
|
|
break;
|
|
|
|
if (register_netdev(dev)) {
|
|
free_netdev(dev);
|
|
break;
|
|
}
|
|
|
|
devs[i] = dev;
|
|
shapers_registered++;
|
|
}
|
|
|
|
if (!shapers_registered) {
|
|
kfree(devs);
|
|
devs = NULL;
|
|
}
|
|
|
|
return (shapers_registered ? 0 : -ENODEV);
|
|
}
|
|
|
|
static void __exit shaper_exit (void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < shapers_registered; i++) {
|
|
if (devs[i]) {
|
|
unregister_netdev(devs[i]);
|
|
free_netdev(devs[i]);
|
|
}
|
|
}
|
|
|
|
kfree(devs);
|
|
devs = NULL;
|
|
}
|
|
|
|
module_init(shaper_init);
|
|
module_exit(shaper_exit);
|
|
MODULE_LICENSE("GPL");
|
|
|