[BNX2]: Move rx indexes into bnx2_napi struct.
[linux-2.6.git] / drivers / net / shaper.c
1 /*
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/module.h>
73 #include <linux/kernel.h>
74 #include <linux/fcntl.h>
75 #include <linux/mm.h>
76 #include <linux/slab.h>
77 #include <linux/string.h>
78 #include <linux/errno.h>
79 #include <linux/netdevice.h>
80 #include <linux/etherdevice.h>
81 #include <linux/skbuff.h>
82 #include <linux/if_arp.h>
83 #include <linux/init.h>
84 #include <linux/if_shaper.h>
85 #include <linux/jiffies.h>
86
87 #include <net/dst.h>
88 #include <net/arp.h>
89 #include <net/net_namespace.h>
90
91 struct shaper_cb {
92         unsigned long   shapeclock;             /* Time it should go out */
93         unsigned long   shapestamp;             /* Stamp for shaper    */
94         __u32           shapelatency;           /* Latency on frame */
95         __u32           shapelen;               /* Frame length in clocks */
96         __u16           shapepend;              /* Pending */
97 };
98 #define SHAPERCB(skb) ((struct shaper_cb *) ((skb)->cb))
99
100 static int sh_debug;            /* Debug flag */
101
102 #define SHAPER_BANNER   "CymruNet Traffic Shaper BETA 0.04 for Linux 2.1\n"
103
104 static void shaper_kick(struct shaper *sh);
105
106 /*
107  *      Compute clocks on a buffer
108  */
109
110 static int shaper_clocks(struct shaper *shaper, struct sk_buff *skb)
111 {
112         int t=skb->len/shaper->bytespertick;
113         return t;
114 }
115
116 /*
117  *      Set the speed of a shaper. We compute this in bytes per tick since
118  *      thats how the machine wants to run. Quoted input is in bits per second
119  *      as is traditional (note not BAUD). We assume 8 bit bytes.
120  */
121
122 static void shaper_setspeed(struct shaper *shaper, int bitspersec)
123 {
124         shaper->bitspersec=bitspersec;
125         shaper->bytespertick=(bitspersec/HZ)/8;
126         if(!shaper->bytespertick)
127                 shaper->bytespertick++;
128 }
129
130 /*
131  *      Throw a frame at a shaper.
132  */
133
134
135 static int shaper_start_xmit(struct sk_buff *skb, struct net_device *dev)
136 {
137         struct shaper *shaper = dev->priv;
138         struct sk_buff *ptr;
139
140         spin_lock(&shaper->lock);
141         ptr=shaper->sendq.prev;
142
143         /*
144          *      Set up our packet details
145          */
146
147         SHAPERCB(skb)->shapelatency=0;
148         SHAPERCB(skb)->shapeclock=shaper->recovery;
149         if(time_before(SHAPERCB(skb)->shapeclock, jiffies))
150                 SHAPERCB(skb)->shapeclock=jiffies;
151         skb->priority=0;        /* short term bug fix */
152         SHAPERCB(skb)->shapestamp=jiffies;
153
154         /*
155          *      Time slots for this packet.
156          */
157
158         SHAPERCB(skb)->shapelen= shaper_clocks(shaper,skb);
159
160         {
161                 struct sk_buff *tmp;
162                 /*
163                  *      Up our shape clock by the time pending on the queue
164                  *      (Should keep this in the shaper as a variable..)
165                  */
166                 for(tmp=skb_peek(&shaper->sendq); tmp!=NULL &&
167                         tmp!=(struct sk_buff *)&shaper->sendq; tmp=tmp->next)
168                         SHAPERCB(skb)->shapeclock+=SHAPERCB(tmp)->shapelen;
169                 /*
170                  *      Queue over time. Spill packet.
171                  */
172                 if(time_after(SHAPERCB(skb)->shapeclock,jiffies + SHAPER_LATENCY)) {
173                         dev_kfree_skb(skb);
174                         dev->stats.tx_dropped++;
175                 } else
176                         skb_queue_tail(&shaper->sendq, skb);
177         }
178
179         if(sh_debug)
180                 printk("Frame queued.\n");
181         if(skb_queue_len(&shaper->sendq)>SHAPER_QLEN)
182         {
183                 ptr=skb_dequeue(&shaper->sendq);
184                 dev_kfree_skb(ptr);
185                 dev->stats.collisions++;
186         }
187         shaper_kick(shaper);
188         spin_unlock(&shaper->lock);
189         return 0;
190 }
191
192 /*
193  *      Transmit from a shaper
194  */
195
196 static void shaper_queue_xmit(struct shaper *shaper, struct sk_buff *skb)
197 {
198         struct sk_buff *newskb=skb_clone(skb, GFP_ATOMIC);
199         if(sh_debug)
200                 printk("Kick frame on %p\n",newskb);
201         if(newskb)
202         {
203                 newskb->dev=shaper->dev;
204                 newskb->priority=2;
205                 if(sh_debug)
206                         printk("Kick new frame to %s, %d\n",
207                                 shaper->dev->name,newskb->priority);
208                 dev_queue_xmit(newskb);
209
210                 shaper->dev->stats.tx_bytes += skb->len;
211                 shaper->dev->stats.tx_packets++;
212
213                 if(sh_debug)
214                         printk("Kicked new frame out.\n");
215                 dev_kfree_skb(skb);
216         }
217 }
218
219 /*
220  *      Timer handler for shaping clock
221  */
222
223 static void shaper_timer(unsigned long data)
224 {
225         struct shaper *shaper = (struct shaper *)data;
226
227         spin_lock(&shaper->lock);
228         shaper_kick(shaper);
229         spin_unlock(&shaper->lock);
230 }
231
232 /*
233  *      Kick a shaper queue and try and do something sensible with the
234  *      queue.
235  */
236
237 static void shaper_kick(struct shaper *shaper)
238 {
239         struct sk_buff *skb;
240
241         /*
242          *      Walk the list (may be empty)
243          */
244
245         while((skb=skb_peek(&shaper->sendq))!=NULL)
246         {
247                 /*
248                  *      Each packet due to go out by now (within an error
249                  *      of SHAPER_BURST) gets kicked onto the link
250                  */
251
252                 if(sh_debug)
253                         printk("Clock = %ld, jiffies = %ld\n", SHAPERCB(skb)->shapeclock, jiffies);
254                 if(time_before_eq(SHAPERCB(skb)->shapeclock, jiffies + SHAPER_BURST))
255                 {
256                         /*
257                          *      Pull the frame and get interrupts back on.
258                          */
259
260                         skb_unlink(skb, &shaper->sendq);
261                         if (shaper->recovery <
262                             SHAPERCB(skb)->shapeclock + SHAPERCB(skb)->shapelen)
263                                 shaper->recovery = SHAPERCB(skb)->shapeclock + SHAPERCB(skb)->shapelen;
264                         /*
265                          *      Pass on to the physical target device via
266                          *      our low level packet thrower.
267                          */
268
269                         SHAPERCB(skb)->shapepend=0;
270                         shaper_queue_xmit(shaper, skb); /* Fire */
271                 }
272                 else
273                         break;
274         }
275
276         /*
277          *      Next kick.
278          */
279
280         if(skb!=NULL)
281                 mod_timer(&shaper->timer, SHAPERCB(skb)->shapeclock);
282 }
283
284
285 /*
286  *      Bring the interface up. We just disallow this until a
287  *      bind.
288  */
289
290 static int shaper_open(struct net_device *dev)
291 {
292         struct shaper *shaper=dev->priv;
293
294         /*
295          *      Can't open until attached.
296          *      Also can't open until speed is set, or we'll get
297          *      a division by zero.
298          */
299
300         if(shaper->dev==NULL)
301                 return -ENODEV;
302         if(shaper->bitspersec==0)
303                 return -EINVAL;
304         return 0;
305 }
306
307 /*
308  *      Closing a shaper flushes the queues.
309  */
310
311 static int shaper_close(struct net_device *dev)
312 {
313         struct shaper *shaper=dev->priv;
314         struct sk_buff *skb;
315
316         while ((skb = skb_dequeue(&shaper->sendq)) != NULL)
317                 dev_kfree_skb(skb);
318
319         spin_lock_bh(&shaper->lock);
320         shaper_kick(shaper);
321         spin_unlock_bh(&shaper->lock);
322
323         del_timer_sync(&shaper->timer);
324         return 0;
325 }
326
327 /*
328  *      Revectored calls. We alter the parameters and call the functions
329  *      for our attached device. This enables us to bandwidth allocate after
330  *      ARP and other resolutions and not before.
331  */
332
333 static int shaper_header(struct sk_buff *skb, struct net_device *dev,
334                          unsigned short type,
335                          const void *daddr, const void *saddr, unsigned len)
336 {
337         struct shaper *sh=dev->priv;
338         int v;
339         if(sh_debug)
340                 printk("Shaper header\n");
341         skb->dev = sh->dev;
342         v = dev_hard_header(skb, sh->dev, type, daddr, saddr, len);
343         skb->dev = dev;
344         return v;
345 }
346
347 static int shaper_rebuild_header(struct sk_buff *skb)
348 {
349         struct shaper *sh=skb->dev->priv;
350         struct net_device *dev=skb->dev;
351         int v;
352         if(sh_debug)
353                 printk("Shaper rebuild header\n");
354         skb->dev=sh->dev;
355         v = sh->dev->header_ops->rebuild(skb);
356         skb->dev=dev;
357         return v;
358 }
359
360 #if 0
361 static int shaper_cache(struct neighbour *neigh, struct hh_cache *hh)
362 {
363         struct shaper *sh=neigh->dev->priv;
364         struct net_device *tmp;
365         int ret;
366         if(sh_debug)
367                 printk("Shaper header cache bind\n");
368         tmp=neigh->dev;
369         neigh->dev=sh->dev;
370         ret=sh->hard_header_cache(neigh,hh);
371         neigh->dev=tmp;
372         return ret;
373 }
374
375 static void shaper_cache_update(struct hh_cache *hh, struct net_device *dev,
376         unsigned char *haddr)
377 {
378         struct shaper *sh=dev->priv;
379         if(sh_debug)
380                 printk("Shaper cache update\n");
381         sh->header_cache_update(hh, sh->dev, haddr);
382 }
383 #endif
384
385 #ifdef CONFIG_INET
386
387 static int shaper_neigh_setup(struct neighbour *n)
388 {
389 #ifdef CONFIG_INET
390         if (n->nud_state == NUD_NONE) {
391                 n->ops = &arp_broken_ops;
392                 n->output = n->ops->output;
393         }
394 #endif
395         return 0;
396 }
397
398 static int shaper_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
399 {
400 #ifdef CONFIG_INET
401         if (p->tbl->family == AF_INET) {
402                 p->neigh_setup = shaper_neigh_setup;
403                 p->ucast_probes = 0;
404                 p->mcast_probes = 0;
405         }
406 #endif
407         return 0;
408 }
409
410 #else /* !(CONFIG_INET) */
411
412 static int shaper_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
413 {
414         return 0;
415 }
416
417 #endif
418
419 static const struct header_ops shaper_ops = {
420         .create  = shaper_header,
421         .rebuild = shaper_rebuild_header,
422 };
423
424 static int shaper_attach(struct net_device *shdev, struct shaper *sh, struct net_device *dev)
425 {
426         sh->dev = dev;
427         sh->get_stats=dev->get_stats;
428
429         shdev->neigh_setup = shaper_neigh_setup_dev;
430         shdev->hard_header_len=dev->hard_header_len;
431         shdev->type=dev->type;
432         shdev->addr_len=dev->addr_len;
433         shdev->mtu=dev->mtu;
434         sh->bitspersec=0;
435         return 0;
436 }
437
438 static int shaper_ioctl(struct net_device *dev,  struct ifreq *ifr, int cmd)
439 {
440         struct shaperconf *ss= (struct shaperconf *)&ifr->ifr_ifru;
441         struct shaper *sh=dev->priv;
442
443         if(ss->ss_cmd == SHAPER_SET_DEV || ss->ss_cmd == SHAPER_SET_SPEED)
444         {
445                 if(!capable(CAP_NET_ADMIN))
446                         return -EPERM;
447         }
448
449         switch(ss->ss_cmd)
450         {
451                 case SHAPER_SET_DEV:
452                 {
453                         struct net_device *them=__dev_get_by_name(&init_net, ss->ss_name);
454                         if(them==NULL)
455                                 return -ENODEV;
456                         if(sh->dev)
457                                 return -EBUSY;
458                         return shaper_attach(dev,dev->priv, them);
459                 }
460                 case SHAPER_GET_DEV:
461                         if(sh->dev==NULL)
462                                 return -ENODEV;
463                         strcpy(ss->ss_name, sh->dev->name);
464                         return 0;
465                 case SHAPER_SET_SPEED:
466                         shaper_setspeed(sh,ss->ss_speed);
467                         return 0;
468                 case SHAPER_GET_SPEED:
469                         ss->ss_speed=sh->bitspersec;
470                         return 0;
471                 default:
472                         return -EINVAL;
473         }
474 }
475
476 static void shaper_init_priv(struct net_device *dev)
477 {
478         struct shaper *sh = dev->priv;
479
480         skb_queue_head_init(&sh->sendq);
481         init_timer(&sh->timer);
482         sh->timer.function=shaper_timer;
483         sh->timer.data=(unsigned long)sh;
484         spin_lock_init(&sh->lock);
485 }
486
487 /*
488  *      Add a shaper device to the system
489  */
490
491 static void __init shaper_setup(struct net_device *dev)
492 {
493         /*
494          *      Set up the shaper.
495          */
496
497         shaper_init_priv(dev);
498
499         dev->open               = shaper_open;
500         dev->stop               = shaper_close;
501         dev->hard_start_xmit    = shaper_start_xmit;
502         dev->set_multicast_list = NULL;
503
504         /*
505          *      Intialise the packet queues
506          */
507
508         /*
509          *      Handlers for when we attach to a device.
510          */
511
512         dev->neigh_setup        = shaper_neigh_setup_dev;
513         dev->do_ioctl           = shaper_ioctl;
514         dev->hard_header_len    = 0;
515         dev->type               = ARPHRD_ETHER; /* initially */
516         dev->set_mac_address    = NULL;
517         dev->mtu                = 1500;
518         dev->addr_len           = 0;
519         dev->tx_queue_len       = 10;
520         dev->flags              = 0;
521 }
522
523 static int shapers = 1;
524 #ifdef MODULE
525
526 module_param(shapers, int, 0);
527 MODULE_PARM_DESC(shapers, "Traffic shaper: maximum number of shapers");
528
529 #else /* MODULE */
530
531 static int __init set_num_shapers(char *str)
532 {
533         shapers = simple_strtol(str, NULL, 0);
534         return 1;
535 }
536
537 __setup("shapers=", set_num_shapers);
538
539 #endif /* MODULE */
540
541 static struct net_device **devs;
542
543 static unsigned int shapers_registered = 0;
544
545 static int __init shaper_init(void)
546 {
547         int i;
548         size_t alloc_size;
549         struct net_device *dev;
550         char name[IFNAMSIZ];
551
552         if (shapers < 1)
553                 return -ENODEV;
554
555         alloc_size = sizeof(*dev) * shapers;
556         devs = kzalloc(alloc_size, GFP_KERNEL);
557         if (!devs)
558                 return -ENOMEM;
559
560         for (i = 0; i < shapers; i++) {
561
562                 snprintf(name, IFNAMSIZ, "shaper%d", i);
563                 dev = alloc_netdev(sizeof(struct shaper), name,
564                                    shaper_setup);
565                 if (!dev)
566                         break;
567
568                 if (register_netdev(dev)) {
569                         free_netdev(dev);
570                         break;
571                 }
572
573                 devs[i] = dev;
574                 shapers_registered++;
575         }
576
577         if (!shapers_registered) {
578                 kfree(devs);
579                 devs = NULL;
580         }
581
582         return (shapers_registered ? 0 : -ENODEV);
583 }
584
585 static void __exit shaper_exit (void)
586 {
587         int i;
588
589         for (i = 0; i < shapers_registered; i++) {
590                 if (devs[i]) {
591                         unregister_netdev(devs[i]);
592                         free_netdev(devs[i]);
593                 }
594         }
595
596         kfree(devs);
597         devs = NULL;
598 }
599
600 module_init(shaper_init);
601 module_exit(shaper_exit);
602 MODULE_LICENSE("GPL");
603