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-rw-r--r--drivers/net/shaper.c755
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diff --git a/drivers/net/shaper.c b/drivers/net/shaper.c
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+/*
+ * Simple traffic shaper for Linux NET3.
+ *
+ * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
+ * http://www.redhat.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
+ * warranty for any of this software. This material is provided
+ * "AS-IS" and at no charge.
+ *
+ *
+ * Algorithm:
+ *
+ * Queue Frame:
+ * Compute time length of frame at regulated speed
+ * Add frame to queue at appropriate point
+ * Adjust time length computation for followup frames
+ * Any frame that falls outside of its boundaries is freed
+ *
+ * We work to the following constants
+ *
+ * SHAPER_QLEN Maximum queued frames
+ * SHAPER_LATENCY Bounding latency on a frame. Leaving this latency
+ * window drops the frame. This stops us queueing
+ * frames for a long time and confusing a remote
+ * host.
+ * SHAPER_MAXSLIP Maximum time a priority frame may jump forward.
+ * That bounds the penalty we will inflict on low
+ * priority traffic.
+ * SHAPER_BURST Time range we call "now" in order to reduce
+ * system load. The more we make this the burstier
+ * the behaviour, the better local performance you
+ * get through packet clustering on routers and the
+ * worse the remote end gets to judge rtts.
+ *
+ * This is designed to handle lower speed links ( < 200K/second or so). We
+ * run off a 100-150Hz base clock typically. This gives us a resolution at
+ * 200Kbit/second of about 2Kbit or 256 bytes. Above that our timer
+ * resolution may start to cause much more burstiness in the traffic. We
+ * could avoid a lot of that by calling kick_shaper() at the end of the
+ * tied device transmissions. If you run above about 100K second you
+ * may need to tune the supposed speed rate for the right values.
+ *
+ * BUGS:
+ * Downing the interface under the shaper before the shaper
+ * will render your machine defunct. Don't for now shape over
+ * PPP or SLIP therefore!
+ * This will be fixed in BETA4
+ *
+ * Update History :
+ *
+ * bh_atomic() SMP races fixes and rewritten the locking code to
+ * be SMP safe and irq-mask friendly.
+ * NOTE: we can't use start_bh_atomic() in kick_shaper()
+ * because it's going to be recalled from an irq handler,
+ * and synchronize_bh() is a nono if called from irq context.
+ * 1999 Andrea Arcangeli
+ *
+ * Device statistics (tx_pakets, tx_bytes,
+ * tx_drops: queue_over_time and collisions: max_queue_exceded)
+ * 1999/06/18 Jordi Murgo <savage@apostols.org>
+ *
+ * Use skb->cb for private data.
+ * 2000/03 Andi Kleen
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/if_arp.h>
+#include <linux/init.h>
+#include <linux/if_shaper.h>
+
+#include <net/dst.h>
+#include <net/arp.h>
+
+struct shaper_cb {
+ unsigned long shapeclock; /* Time it should go out */
+ unsigned long shapestamp; /* Stamp for shaper */
+ __u32 shapelatency; /* Latency on frame */
+ __u32 shapelen; /* Frame length in clocks */
+ __u16 shapepend; /* Pending */
+};
+#define SHAPERCB(skb) ((struct shaper_cb *) ((skb)->cb))
+
+static int sh_debug; /* Debug flag */
+
+#define SHAPER_BANNER "CymruNet Traffic Shaper BETA 0.04 for Linux 2.1\n"
+
+/*
+ * Locking
+ */
+
+static int shaper_lock(struct shaper *sh)
+{
+ /*
+ * Lock in an interrupt must fail
+ */
+ while (test_and_set_bit(0, &sh->locked))
+ {
+ if (!in_interrupt())
+ sleep_on(&sh->wait_queue);
+ else
+ return 0;
+
+ }
+ return 1;
+}
+
+static void shaper_kick(struct shaper *sh);
+
+static void shaper_unlock(struct shaper *sh)
+{
+ clear_bit(0, &sh->locked);
+ wake_up(&sh->wait_queue);
+ shaper_kick(sh);
+}
+
+/*
+ * Compute clocks on a buffer
+ */
+
+static int shaper_clocks(struct shaper *shaper, struct sk_buff *skb)
+{
+ int t=skb->len/shaper->bytespertick;
+ return t;
+}
+
+/*
+ * Set the speed of a shaper. We compute this in bytes per tick since
+ * thats how the machine wants to run. Quoted input is in bits per second
+ * as is traditional (note not BAUD). We assume 8 bit bytes.
+ */
+
+static void shaper_setspeed(struct shaper *shaper, int bitspersec)
+{
+ shaper->bitspersec=bitspersec;
+ shaper->bytespertick=(bitspersec/HZ)/8;
+ if(!shaper->bytespertick)
+ shaper->bytespertick++;
+}
+
+/*
+ * Throw a frame at a shaper.
+ */
+
+static int shaper_qframe(struct shaper *shaper, struct sk_buff *skb)
+{
+ struct sk_buff *ptr;
+
+ /*
+ * Get ready to work on this shaper. Lock may fail if its
+ * an interrupt and locked.
+ */
+
+ if(!shaper_lock(shaper))
+ return -1;
+ ptr=shaper->sendq.prev;
+
+ /*
+ * Set up our packet details
+ */
+
+ SHAPERCB(skb)->shapelatency=0;
+ SHAPERCB(skb)->shapeclock=shaper->recovery;
+ if(time_before(SHAPERCB(skb)->shapeclock, jiffies))
+ SHAPERCB(skb)->shapeclock=jiffies;
+ skb->priority=0; /* short term bug fix */
+ SHAPERCB(skb)->shapestamp=jiffies;
+
+ /*
+ * Time slots for this packet.
+ */
+
+ SHAPERCB(skb)->shapelen= shaper_clocks(shaper,skb);
+
+#ifdef SHAPER_COMPLEX /* and broken.. */
+
+ while(ptr && ptr!=(struct sk_buff *)&shaper->sendq)
+ {
+ if(ptr->pri<skb->pri
+ && jiffies - SHAPERCB(ptr)->shapeclock < SHAPER_MAXSLIP)
+ {
+ struct sk_buff *tmp=ptr->prev;
+
+ /*
+ * It goes before us therefore we slip the length
+ * of the new frame.
+ */
+
+ SHAPERCB(ptr)->shapeclock+=SHAPERCB(skb)->shapelen;
+ SHAPERCB(ptr)->shapelatency+=SHAPERCB(skb)->shapelen;
+
+ /*
+ * The packet may have slipped so far back it
+ * fell off.
+ */
+ if(SHAPERCB(ptr)->shapelatency > SHAPER_LATENCY)
+ {
+ skb_unlink(ptr);
+ dev_kfree_skb(ptr);
+ }
+ ptr=tmp;
+ }
+ else
+ break;
+ }
+ if(ptr==NULL || ptr==(struct sk_buff *)&shaper->sendq)
+ skb_queue_head(&shaper->sendq,skb);
+ else
+ {
+ struct sk_buff *tmp;
+ /*
+ * Set the packet clock out time according to the
+ * frames ahead. Im sure a bit of thought could drop
+ * this loop.
+ */
+ for(tmp=skb_peek(&shaper->sendq); tmp!=NULL && tmp!=ptr; tmp=tmp->next)
+ SHAPERCB(skb)->shapeclock+=tmp->shapelen;
+ skb_append(ptr,skb);
+ }
+#else
+ {
+ struct sk_buff *tmp;
+ /*
+ * Up our shape clock by the time pending on the queue
+ * (Should keep this in the shaper as a variable..)
+ */
+ for(tmp=skb_peek(&shaper->sendq); tmp!=NULL &&
+ tmp!=(struct sk_buff *)&shaper->sendq; tmp=tmp->next)
+ SHAPERCB(skb)->shapeclock+=SHAPERCB(tmp)->shapelen;
+ /*
+ * Queue over time. Spill packet.
+ */
+ if(SHAPERCB(skb)->shapeclock-jiffies > SHAPER_LATENCY) {
+ dev_kfree_skb(skb);
+ shaper->stats.tx_dropped++;
+ } else
+ skb_queue_tail(&shaper->sendq, skb);
+ }
+#endif
+ if(sh_debug)
+ printk("Frame queued.\n");
+ if(skb_queue_len(&shaper->sendq)>SHAPER_QLEN)
+ {
+ ptr=skb_dequeue(&shaper->sendq);
+ dev_kfree_skb(ptr);
+ shaper->stats.collisions++;
+ }
+ shaper_unlock(shaper);
+ return 0;
+}
+
+/*
+ * Transmit from a shaper
+ */
+
+static void shaper_queue_xmit(struct shaper *shaper, struct sk_buff *skb)
+{
+ struct sk_buff *newskb=skb_clone(skb, GFP_ATOMIC);
+ if(sh_debug)
+ printk("Kick frame on %p\n",newskb);
+ if(newskb)
+ {
+ newskb->dev=shaper->dev;
+ newskb->priority=2;
+ if(sh_debug)
+ printk("Kick new frame to %s, %d\n",
+ shaper->dev->name,newskb->priority);
+ dev_queue_xmit(newskb);
+
+ shaper->stats.tx_bytes += skb->len;
+ shaper->stats.tx_packets++;
+
+ if(sh_debug)
+ printk("Kicked new frame out.\n");
+ dev_kfree_skb(skb);
+ }
+}
+
+/*
+ * Timer handler for shaping clock
+ */
+
+static void shaper_timer(unsigned long data)
+{
+ struct shaper *sh=(struct shaper *)data;
+ shaper_kick(sh);
+}
+
+/*
+ * Kick a shaper queue and try and do something sensible with the
+ * queue.
+ */
+
+static void shaper_kick(struct shaper *shaper)
+{
+ struct sk_buff *skb;
+
+ /*
+ * Shaper unlock will kick
+ */
+
+ if (test_and_set_bit(0, &shaper->locked))
+ {
+ if(sh_debug)
+ printk("Shaper locked.\n");
+ mod_timer(&shaper->timer, jiffies);
+ return;
+ }
+
+
+ /*
+ * Walk the list (may be empty)
+ */
+
+ while((skb=skb_peek(&shaper->sendq))!=NULL)
+ {
+ /*
+ * Each packet due to go out by now (within an error
+ * of SHAPER_BURST) gets kicked onto the link
+ */
+
+ if(sh_debug)
+ printk("Clock = %ld, jiffies = %ld\n", SHAPERCB(skb)->shapeclock, jiffies);
+ if(time_before_eq(SHAPERCB(skb)->shapeclock, jiffies + SHAPER_BURST))
+ {
+ /*
+ * Pull the frame and get interrupts back on.
+ */
+
+ skb_unlink(skb);
+ if (shaper->recovery <
+ SHAPERCB(skb)->shapeclock + SHAPERCB(skb)->shapelen)
+ shaper->recovery = SHAPERCB(skb)->shapeclock + SHAPERCB(skb)->shapelen;
+ /*
+ * Pass on to the physical target device via
+ * our low level packet thrower.
+ */
+
+ SHAPERCB(skb)->shapepend=0;
+ shaper_queue_xmit(shaper, skb); /* Fire */
+ }
+ else
+ break;
+ }
+
+ /*
+ * Next kick.
+ */
+
+ if(skb!=NULL)
+ mod_timer(&shaper->timer, SHAPERCB(skb)->shapeclock);
+
+ clear_bit(0, &shaper->locked);
+}
+
+
+/*
+ * Flush the shaper queues on a closedown
+ */
+
+static void shaper_flush(struct shaper *shaper)
+{
+ struct sk_buff *skb;
+ if(!shaper_lock(shaper))
+ {
+ printk(KERN_ERR "shaper: shaper_flush() called by an irq!\n");
+ return;
+ }
+ while((skb=skb_dequeue(&shaper->sendq))!=NULL)
+ dev_kfree_skb(skb);
+ shaper_unlock(shaper);
+}
+
+/*
+ * Bring the interface up. We just disallow this until a
+ * bind.
+ */
+
+static int shaper_open(struct net_device *dev)
+{
+ struct shaper *shaper=dev->priv;
+
+ /*
+ * Can't open until attached.
+ * Also can't open until speed is set, or we'll get
+ * a division by zero.
+ */
+
+ if(shaper->dev==NULL)
+ return -ENODEV;
+ if(shaper->bitspersec==0)
+ return -EINVAL;
+ return 0;
+}
+
+/*
+ * Closing a shaper flushes the queues.
+ */
+
+static int shaper_close(struct net_device *dev)
+{
+ struct shaper *shaper=dev->priv;
+ shaper_flush(shaper);
+ del_timer_sync(&shaper->timer);
+ return 0;
+}
+
+/*
+ * Revectored calls. We alter the parameters and call the functions
+ * for our attached device. This enables us to bandwidth allocate after
+ * ARP and other resolutions and not before.
+ */
+
+
+static int shaper_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct shaper *sh=dev->priv;
+ return shaper_qframe(sh, skb);
+}
+
+static struct net_device_stats *shaper_get_stats(struct net_device *dev)
+{
+ struct shaper *sh=dev->priv;
+ return &sh->stats;
+}
+
+static int shaper_header(struct sk_buff *skb, struct net_device *dev,
+ unsigned short type, void *daddr, void *saddr, unsigned len)
+{
+ struct shaper *sh=dev->priv;
+ int v;
+ if(sh_debug)
+ printk("Shaper header\n");
+ skb->dev=sh->dev;
+ v=sh->hard_header(skb,sh->dev,type,daddr,saddr,len);
+ skb->dev=dev;
+ return v;
+}
+
+static int shaper_rebuild_header(struct sk_buff *skb)
+{
+ struct shaper *sh=skb->dev->priv;
+ struct net_device *dev=skb->dev;
+ int v;
+ if(sh_debug)
+ printk("Shaper rebuild header\n");
+ skb->dev=sh->dev;
+ v=sh->rebuild_header(skb);
+ skb->dev=dev;
+ return v;
+}
+
+#if 0
+static int shaper_cache(struct neighbour *neigh, struct hh_cache *hh)
+{
+ struct shaper *sh=neigh->dev->priv;
+ struct net_device *tmp;
+ int ret;
+ if(sh_debug)
+ printk("Shaper header cache bind\n");
+ tmp=neigh->dev;
+ neigh->dev=sh->dev;
+ ret=sh->hard_header_cache(neigh,hh);
+ neigh->dev=tmp;
+ return ret;
+}
+
+static void shaper_cache_update(struct hh_cache *hh, struct net_device *dev,
+ unsigned char *haddr)
+{
+ struct shaper *sh=dev->priv;
+ if(sh_debug)
+ printk("Shaper cache update\n");
+ sh->header_cache_update(hh, sh->dev, haddr);
+}
+#endif
+
+#ifdef CONFIG_INET
+
+static int shaper_neigh_setup(struct neighbour *n)
+{
+#ifdef CONFIG_INET
+ if (n->nud_state == NUD_NONE) {
+ n->ops = &arp_broken_ops;
+ n->output = n->ops->output;
+ }
+#endif
+ return 0;
+}
+
+static int shaper_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
+{
+#ifdef CONFIG_INET
+ if (p->tbl->family == AF_INET) {
+ p->neigh_setup = shaper_neigh_setup;
+ p->ucast_probes = 0;
+ p->mcast_probes = 0;
+ }
+#endif
+ return 0;
+}
+
+#else /* !(CONFIG_INET) */
+
+static int shaper_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
+{
+ return 0;
+}
+
+#endif
+
+static int shaper_attach(struct net_device *shdev, struct shaper *sh, struct net_device *dev)
+{
+ sh->dev = dev;
+ sh->hard_start_xmit=dev->hard_start_xmit;
+ sh->get_stats=dev->get_stats;
+ if(dev->hard_header)
+ {
+ sh->hard_header=dev->hard_header;
+ shdev->hard_header = shaper_header;
+ }
+ else
+ shdev->hard_header = NULL;
+
+ if(dev->rebuild_header)
+ {
+ sh->rebuild_header = dev->rebuild_header;
+ shdev->rebuild_header = shaper_rebuild_header;
+ }
+ else
+ shdev->rebuild_header = NULL;
+
+#if 0
+ if(dev->hard_header_cache)
+ {
+ sh->hard_header_cache = dev->hard_header_cache;
+ shdev->hard_header_cache= shaper_cache;
+ }
+ else
+ {
+ shdev->hard_header_cache= NULL;
+ }
+
+ if(dev->header_cache_update)
+ {
+ sh->header_cache_update = dev->header_cache_update;
+ shdev->header_cache_update = shaper_cache_update;
+ }
+ else
+ shdev->header_cache_update= NULL;
+#else
+ shdev->header_cache_update = NULL;
+ shdev->hard_header_cache = NULL;
+#endif
+ shdev->neigh_setup = shaper_neigh_setup_dev;
+
+ shdev->hard_header_len=dev->hard_header_len;
+ shdev->type=dev->type;
+ shdev->addr_len=dev->addr_len;
+ shdev->mtu=dev->mtu;
+ sh->bitspersec=0;
+ return 0;
+}
+
+static int shaper_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+ struct shaperconf *ss= (struct shaperconf *)&ifr->ifr_ifru;
+ struct shaper *sh=dev->priv;
+
+ if(ss->ss_cmd == SHAPER_SET_DEV || ss->ss_cmd == SHAPER_SET_SPEED)
+ {
+ if(!capable(CAP_NET_ADMIN))
+ return -EPERM;
+ }
+
+ switch(ss->ss_cmd)
+ {
+ case SHAPER_SET_DEV:
+ {
+ struct net_device *them=__dev_get_by_name(ss->ss_name);
+ if(them==NULL)
+ return -ENODEV;
+ if(sh->dev)
+ return -EBUSY;
+ return shaper_attach(dev,dev->priv, them);
+ }
+ case SHAPER_GET_DEV:
+ if(sh->dev==NULL)
+ return -ENODEV;
+ strcpy(ss->ss_name, sh->dev->name);
+ return 0;
+ case SHAPER_SET_SPEED:
+ shaper_setspeed(sh,ss->ss_speed);
+ return 0;
+ case SHAPER_GET_SPEED:
+ ss->ss_speed=sh->bitspersec;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static void shaper_init_priv(struct net_device *dev)
+{
+ struct shaper *sh = dev->priv;
+
+ skb_queue_head_init(&sh->sendq);
+ init_timer(&sh->timer);
+ sh->timer.function=shaper_timer;
+ sh->timer.data=(unsigned long)sh;
+ init_waitqueue_head(&sh->wait_queue);
+}
+
+/*
+ * Add a shaper device to the system
+ */
+
+static void __init shaper_setup(struct net_device *dev)
+{
+ /*
+ * Set up the shaper.
+ */
+
+ SET_MODULE_OWNER(dev);
+
+ shaper_init_priv(dev);
+
+ dev->open = shaper_open;
+ dev->stop = shaper_close;
+ dev->hard_start_xmit = shaper_start_xmit;
+ dev->get_stats = shaper_get_stats;
+ dev->set_multicast_list = NULL;
+
+ /*
+ * 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");
+