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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Simple traffic shaper for Linux NET3.
3 *
4 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
5 * http://www.redhat.com
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
13 * warranty for any of this software. This material is provided
14 * "AS-IS" and at no charge.
15 *
16 *
17 * Algorithm:
18 *
19 * Queue Frame:
20 * Compute time length of frame at regulated speed
21 * Add frame to queue at appropriate point
22 * Adjust time length computation for followup frames
23 * Any frame that falls outside of its boundaries is freed
24 *
25 * We work to the following constants
26 *
27 * SHAPER_QLEN Maximum queued frames
28 * SHAPER_LATENCY Bounding latency on a frame. Leaving this latency
29 * window drops the frame. This stops us queueing
30 * frames for a long time and confusing a remote
31 * host.
32 * SHAPER_MAXSLIP Maximum time a priority frame may jump forward.
33 * That bounds the penalty we will inflict on low
34 * priority traffic.
35 * SHAPER_BURST Time range we call "now" in order to reduce
36 * system load. The more we make this the burstier
37 * the behaviour, the better local performance you
38 * get through packet clustering on routers and the
39 * worse the remote end gets to judge rtts.
40 *
41 * This is designed to handle lower speed links ( < 200K/second or so). We
42 * run off a 100-150Hz base clock typically. This gives us a resolution at
43 * 200Kbit/second of about 2Kbit or 256 bytes. Above that our timer
44 * resolution may start to cause much more burstiness in the traffic. We
45 * could avoid a lot of that by calling kick_shaper() at the end of the
46 * tied device transmissions. If you run above about 100K second you
47 * may need to tune the supposed speed rate for the right values.
48 *
49 * BUGS:
50 * Downing the interface under the shaper before the shaper
51 * will render your machine defunct. Don't for now shape over
52 * PPP or SLIP therefore!
53 * This will be fixed in BETA4
54 *
55 * Update History :
56 *
57 * bh_atomic() SMP races fixes and rewritten the locking code to
58 * be SMP safe and irq-mask friendly.
59 * NOTE: we can't use start_bh_atomic() in kick_shaper()
60 * because it's going to be recalled from an irq handler,
61 * and synchronize_bh() is a nono if called from irq context.
62 * 1999 Andrea Arcangeli
63 *
64 * Device statistics (tx_pakets, tx_bytes,
65 * tx_drops: queue_over_time and collisions: max_queue_exceded)
66 * 1999/06/18 Jordi Murgo <savage@apostols.org>
67 *
68 * Use skb->cb for private data.
69 * 2000/03 Andi Kleen
70 */
71
72#include <linux/config.h>
73#include <linux/module.h>
74#include <linux/kernel.h>
75#include <linux/fcntl.h>
76#include <linux/mm.h>
77#include <linux/slab.h>
78#include <linux/string.h>
79#include <linux/errno.h>
80#include <linux/netdevice.h>
81#include <linux/etherdevice.h>
82#include <linux/skbuff.h>
83#include <linux/if_arp.h>
84#include <linux/init.h>
85#include <linux/if_shaper.h>
86
87#include <net/dst.h>
88#include <net/arp.h>
89
90struct shaper_cb {
91 unsigned long shapeclock; /* Time it should go out */
92 unsigned long shapestamp; /* Stamp for shaper */
93 __u32 shapelatency; /* Latency on frame */
94 __u32 shapelen; /* Frame length in clocks */
95 __u16 shapepend; /* Pending */
96};
97#define SHAPERCB(skb) ((struct shaper_cb *) ((skb)->cb))
98
99static int sh_debug; /* Debug flag */
100
101#define SHAPER_BANNER "CymruNet Traffic Shaper BETA 0.04 for Linux 2.1\n"
102
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103static void shaper_kick(struct shaper *sh);
104
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105/*
106 * Compute clocks on a buffer
107 */
108
109static int shaper_clocks(struct shaper *shaper, struct sk_buff *skb)
110{
111 int t=skb->len/shaper->bytespertick;
112 return t;
113}
114
115/*
116 * Set the speed of a shaper. We compute this in bytes per tick since
117 * thats how the machine wants to run. Quoted input is in bits per second
118 * as is traditional (note not BAUD). We assume 8 bit bytes.
119 */
120
121static void shaper_setspeed(struct shaper *shaper, int bitspersec)
122{
123 shaper->bitspersec=bitspersec;
124 shaper->bytespertick=(bitspersec/HZ)/8;
125 if(!shaper->bytespertick)
126 shaper->bytespertick++;
127}
128
129/*
130 * Throw a frame at a shaper.
131 */
132
Christoph Hellwigb597ef42005-06-02 16:36:00 -0700133
134static int shaper_start_xmit(struct sk_buff *skb, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135{
Christoph Hellwigb597ef42005-06-02 16:36:00 -0700136 struct shaper *shaper = dev->priv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 struct sk_buff *ptr;
Christoph Hellwigbc971de2005-07-05 15:03:46 -0700138
139 spin_lock(&shaper->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 ptr=shaper->sendq.prev;
141
142 /*
143 * Set up our packet details
144 */
145
146 SHAPERCB(skb)->shapelatency=0;
147 SHAPERCB(skb)->shapeclock=shaper->recovery;
148 if(time_before(SHAPERCB(skb)->shapeclock, jiffies))
149 SHAPERCB(skb)->shapeclock=jiffies;
150 skb->priority=0; /* short term bug fix */
151 SHAPERCB(skb)->shapestamp=jiffies;
152
153 /*
154 * Time slots for this packet.
155 */
156
157 SHAPERCB(skb)->shapelen= shaper_clocks(shaper,skb);
158
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 {
160 struct sk_buff *tmp;
161 /*
162 * Up our shape clock by the time pending on the queue
163 * (Should keep this in the shaper as a variable..)
164 */
165 for(tmp=skb_peek(&shaper->sendq); tmp!=NULL &&
166 tmp!=(struct sk_buff *)&shaper->sendq; tmp=tmp->next)
167 SHAPERCB(skb)->shapeclock+=SHAPERCB(tmp)->shapelen;
168 /*
169 * Queue over time. Spill packet.
170 */
171 if(SHAPERCB(skb)->shapeclock-jiffies > SHAPER_LATENCY) {
172 dev_kfree_skb(skb);
173 shaper->stats.tx_dropped++;
174 } else
175 skb_queue_tail(&shaper->sendq, skb);
176 }
David S. Miller8728b832005-08-09 19:25:21 -0700177
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 if(sh_debug)
179 printk("Frame queued.\n");
180 if(skb_queue_len(&shaper->sendq)>SHAPER_QLEN)
181 {
182 ptr=skb_dequeue(&shaper->sendq);
183 dev_kfree_skb(ptr);
184 shaper->stats.collisions++;
185 }
Christoph Hellwigb597ef42005-06-02 16:36:00 -0700186 shaper_kick(shaper);
Christoph Hellwigbc971de2005-07-05 15:03:46 -0700187 spin_unlock(&shaper->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 return 0;
189}
190
191/*
192 * Transmit from a shaper
193 */
194
195static void shaper_queue_xmit(struct shaper *shaper, struct sk_buff *skb)
196{
197 struct sk_buff *newskb=skb_clone(skb, GFP_ATOMIC);
198 if(sh_debug)
199 printk("Kick frame on %p\n",newskb);
200 if(newskb)
201 {
202 newskb->dev=shaper->dev;
203 newskb->priority=2;
204 if(sh_debug)
205 printk("Kick new frame to %s, %d\n",
206 shaper->dev->name,newskb->priority);
207 dev_queue_xmit(newskb);
208
209 shaper->stats.tx_bytes += skb->len;
210 shaper->stats.tx_packets++;
211
212 if(sh_debug)
213 printk("Kicked new frame out.\n");
214 dev_kfree_skb(skb);
215 }
216}
217
218/*
219 * Timer handler for shaping clock
220 */
221
222static void shaper_timer(unsigned long data)
223{
Christoph Hellwigb597ef42005-06-02 16:36:00 -0700224 struct shaper *shaper = (struct shaper *)data;
225
Christoph Hellwigbc971de2005-07-05 15:03:46 -0700226 spin_lock(&shaper->lock);
227 shaper_kick(shaper);
228 spin_unlock(&shaper->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229}
230
231/*
232 * Kick a shaper queue and try and do something sensible with the
233 * queue.
234 */
235
236static void shaper_kick(struct shaper *shaper)
237{
238 struct sk_buff *skb;
239
240 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 * Walk the list (may be empty)
242 */
243
244 while((skb=skb_peek(&shaper->sendq))!=NULL)
245 {
246 /*
247 * Each packet due to go out by now (within an error
248 * of SHAPER_BURST) gets kicked onto the link
249 */
250
251 if(sh_debug)
252 printk("Clock = %ld, jiffies = %ld\n", SHAPERCB(skb)->shapeclock, jiffies);
253 if(time_before_eq(SHAPERCB(skb)->shapeclock, jiffies + SHAPER_BURST))
254 {
255 /*
256 * Pull the frame and get interrupts back on.
257 */
258
David S. Miller8728b832005-08-09 19:25:21 -0700259 skb_unlink(skb, &shaper->sendq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 if (shaper->recovery <
261 SHAPERCB(skb)->shapeclock + SHAPERCB(skb)->shapelen)
262 shaper->recovery = SHAPERCB(skb)->shapeclock + SHAPERCB(skb)->shapelen;
263 /*
264 * Pass on to the physical target device via
265 * our low level packet thrower.
266 */
267
268 SHAPERCB(skb)->shapepend=0;
269 shaper_queue_xmit(shaper, skb); /* Fire */
270 }
271 else
272 break;
273 }
274
275 /*
276 * Next kick.
277 */
278
279 if(skb!=NULL)
280 mod_timer(&shaper->timer, SHAPERCB(skb)->shapeclock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281}
282
283
284/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 * Bring the interface up. We just disallow this until a
286 * bind.
287 */
288
289static int shaper_open(struct net_device *dev)
290{
291 struct shaper *shaper=dev->priv;
292
293 /*
294 * Can't open until attached.
295 * Also can't open until speed is set, or we'll get
296 * a division by zero.
297 */
298
299 if(shaper->dev==NULL)
300 return -ENODEV;
301 if(shaper->bitspersec==0)
302 return -EINVAL;
303 return 0;
304}
305
306/*
307 * Closing a shaper flushes the queues.
308 */
309
310static int shaper_close(struct net_device *dev)
311{
312 struct shaper *shaper=dev->priv;
Christoph Hellwigbc971de2005-07-05 15:03:46 -0700313 struct sk_buff *skb;
314
315 while ((skb = skb_dequeue(&shaper->sendq)) != NULL)
316 dev_kfree_skb(skb);
317
318 spin_lock_bh(&shaper->lock);
319 shaper_kick(shaper);
320 spin_unlock_bh(&shaper->lock);
321
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 del_timer_sync(&shaper->timer);
323 return 0;
324}
325
326/*
327 * Revectored calls. We alter the parameters and call the functions
328 * for our attached device. This enables us to bandwidth allocate after
329 * ARP and other resolutions and not before.
330 */
331
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332static struct net_device_stats *shaper_get_stats(struct net_device *dev)
333{
334 struct shaper *sh=dev->priv;
335 return &sh->stats;
336}
337
338static int shaper_header(struct sk_buff *skb, struct net_device *dev,
339 unsigned short type, void *daddr, void *saddr, unsigned len)
340{
341 struct shaper *sh=dev->priv;
342 int v;
343 if(sh_debug)
344 printk("Shaper header\n");
345 skb->dev=sh->dev;
346 v=sh->hard_header(skb,sh->dev,type,daddr,saddr,len);
347 skb->dev=dev;
348 return v;
349}
350
351static int shaper_rebuild_header(struct sk_buff *skb)
352{
353 struct shaper *sh=skb->dev->priv;
354 struct net_device *dev=skb->dev;
355 int v;
356 if(sh_debug)
357 printk("Shaper rebuild header\n");
358 skb->dev=sh->dev;
359 v=sh->rebuild_header(skb);
360 skb->dev=dev;
361 return v;
362}
363
364#if 0
365static int shaper_cache(struct neighbour *neigh, struct hh_cache *hh)
366{
367 struct shaper *sh=neigh->dev->priv;
368 struct net_device *tmp;
369 int ret;
370 if(sh_debug)
371 printk("Shaper header cache bind\n");
372 tmp=neigh->dev;
373 neigh->dev=sh->dev;
374 ret=sh->hard_header_cache(neigh,hh);
375 neigh->dev=tmp;
376 return ret;
377}
378
379static void shaper_cache_update(struct hh_cache *hh, struct net_device *dev,
380 unsigned char *haddr)
381{
382 struct shaper *sh=dev->priv;
383 if(sh_debug)
384 printk("Shaper cache update\n");
385 sh->header_cache_update(hh, sh->dev, haddr);
386}
387#endif
388
389#ifdef CONFIG_INET
390
391static int shaper_neigh_setup(struct neighbour *n)
392{
393#ifdef CONFIG_INET
394 if (n->nud_state == NUD_NONE) {
395 n->ops = &arp_broken_ops;
396 n->output = n->ops->output;
397 }
398#endif
399 return 0;
400}
401
402static int shaper_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
403{
404#ifdef CONFIG_INET
405 if (p->tbl->family == AF_INET) {
406 p->neigh_setup = shaper_neigh_setup;
407 p->ucast_probes = 0;
408 p->mcast_probes = 0;
409 }
410#endif
411 return 0;
412}
413
414#else /* !(CONFIG_INET) */
415
416static int shaper_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
417{
418 return 0;
419}
420
421#endif
422
423static int shaper_attach(struct net_device *shdev, struct shaper *sh, struct net_device *dev)
424{
425 sh->dev = dev;
426 sh->hard_start_xmit=dev->hard_start_xmit;
427 sh->get_stats=dev->get_stats;
428 if(dev->hard_header)
429 {
430 sh->hard_header=dev->hard_header;
431 shdev->hard_header = shaper_header;
432 }
433 else
434 shdev->hard_header = NULL;
435
436 if(dev->rebuild_header)
437 {
438 sh->rebuild_header = dev->rebuild_header;
439 shdev->rebuild_header = shaper_rebuild_header;
440 }
441 else
442 shdev->rebuild_header = NULL;
443
444#if 0
445 if(dev->hard_header_cache)
446 {
447 sh->hard_header_cache = dev->hard_header_cache;
448 shdev->hard_header_cache= shaper_cache;
449 }
450 else
451 {
452 shdev->hard_header_cache= NULL;
453 }
454
455 if(dev->header_cache_update)
456 {
457 sh->header_cache_update = dev->header_cache_update;
458 shdev->header_cache_update = shaper_cache_update;
459 }
460 else
461 shdev->header_cache_update= NULL;
462#else
463 shdev->header_cache_update = NULL;
464 shdev->hard_header_cache = NULL;
465#endif
466 shdev->neigh_setup = shaper_neigh_setup_dev;
467
468 shdev->hard_header_len=dev->hard_header_len;
469 shdev->type=dev->type;
470 shdev->addr_len=dev->addr_len;
471 shdev->mtu=dev->mtu;
472 sh->bitspersec=0;
473 return 0;
474}
475
476static int shaper_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
477{
478 struct shaperconf *ss= (struct shaperconf *)&ifr->ifr_ifru;
479 struct shaper *sh=dev->priv;
480
481 if(ss->ss_cmd == SHAPER_SET_DEV || ss->ss_cmd == SHAPER_SET_SPEED)
482 {
483 if(!capable(CAP_NET_ADMIN))
484 return -EPERM;
485 }
486
487 switch(ss->ss_cmd)
488 {
489 case SHAPER_SET_DEV:
490 {
491 struct net_device *them=__dev_get_by_name(ss->ss_name);
492 if(them==NULL)
493 return -ENODEV;
494 if(sh->dev)
495 return -EBUSY;
496 return shaper_attach(dev,dev->priv, them);
497 }
498 case SHAPER_GET_DEV:
499 if(sh->dev==NULL)
500 return -ENODEV;
501 strcpy(ss->ss_name, sh->dev->name);
502 return 0;
503 case SHAPER_SET_SPEED:
504 shaper_setspeed(sh,ss->ss_speed);
505 return 0;
506 case SHAPER_GET_SPEED:
507 ss->ss_speed=sh->bitspersec;
508 return 0;
509 default:
510 return -EINVAL;
511 }
512}
513
514static void shaper_init_priv(struct net_device *dev)
515{
516 struct shaper *sh = dev->priv;
517
518 skb_queue_head_init(&sh->sendq);
519 init_timer(&sh->timer);
520 sh->timer.function=shaper_timer;
521 sh->timer.data=(unsigned long)sh;
Christoph Hellwigbc971de2005-07-05 15:03:46 -0700522 spin_lock_init(&sh->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523}
524
525/*
526 * Add a shaper device to the system
527 */
528
529static void __init shaper_setup(struct net_device *dev)
530{
531 /*
532 * Set up the shaper.
533 */
534
535 SET_MODULE_OWNER(dev);
536
537 shaper_init_priv(dev);
538
539 dev->open = shaper_open;
540 dev->stop = shaper_close;
541 dev->hard_start_xmit = shaper_start_xmit;
542 dev->get_stats = shaper_get_stats;
543 dev->set_multicast_list = NULL;
544
545 /*
546 * Intialise the packet queues
547 */
548
549 /*
550 * Handlers for when we attach to a device.
551 */
552
553 dev->hard_header = shaper_header;
554 dev->rebuild_header = shaper_rebuild_header;
555#if 0
556 dev->hard_header_cache = shaper_cache;
557 dev->header_cache_update= shaper_cache_update;
558#endif
559 dev->neigh_setup = shaper_neigh_setup_dev;
560 dev->do_ioctl = shaper_ioctl;
561 dev->hard_header_len = 0;
562 dev->type = ARPHRD_ETHER; /* initially */
563 dev->set_mac_address = NULL;
564 dev->mtu = 1500;
565 dev->addr_len = 0;
566 dev->tx_queue_len = 10;
567 dev->flags = 0;
568}
569
570static int shapers = 1;
571#ifdef MODULE
572
573module_param(shapers, int, 0);
574MODULE_PARM_DESC(shapers, "Traffic shaper: maximum number of shapers");
575
576#else /* MODULE */
577
578static int __init set_num_shapers(char *str)
579{
580 shapers = simple_strtol(str, NULL, 0);
581 return 1;
582}
583
584__setup("shapers=", set_num_shapers);
585
586#endif /* MODULE */
587
588static struct net_device **devs;
589
590static unsigned int shapers_registered = 0;
591
592static int __init shaper_init(void)
593{
594 int i;
595 size_t alloc_size;
596 struct net_device *dev;
597 char name[IFNAMSIZ];
598
599 if (shapers < 1)
600 return -ENODEV;
601
602 alloc_size = sizeof(*dev) * shapers;
603 devs = kmalloc(alloc_size, GFP_KERNEL);
604 if (!devs)
605 return -ENOMEM;
606 memset(devs, 0, alloc_size);
607
608 for (i = 0; i < shapers; i++) {
609
610 snprintf(name, IFNAMSIZ, "shaper%d", i);
611 dev = alloc_netdev(sizeof(struct shaper), name,
612 shaper_setup);
613 if (!dev)
614 break;
615
616 if (register_netdev(dev)) {
617 free_netdev(dev);
618 break;
619 }
620
621 devs[i] = dev;
622 shapers_registered++;
623 }
624
625 if (!shapers_registered) {
626 kfree(devs);
627 devs = NULL;
628 }
629
630 return (shapers_registered ? 0 : -ENODEV);
631}
632
633static void __exit shaper_exit (void)
634{
635 int i;
636
637 for (i = 0; i < shapers_registered; i++) {
638 if (devs[i]) {
639 unregister_netdev(devs[i]);
640 free_netdev(devs[i]);
641 }
642 }
643
644 kfree(devs);
645 devs = NULL;
646}
647
648module_init(shaper_init);
649module_exit(shaper_exit);
650MODULE_LICENSE("GPL");
651