diff options
Diffstat (limited to 'drivers/net/shaper.c')
| -rw-r--r-- | drivers/net/shaper.c | 755 |
1 files changed, 755 insertions, 0 deletions
diff --git a/drivers/net/shaper.c b/drivers/net/shaper.c new file mode 100644 index 000000000000..e68cf5fb4920 --- /dev/null +++ b/drivers/net/shaper.c @@ -0,0 +1,755 @@ +/* + * 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"); + |