drivers/net/eql.c: Fix a dev leakage.
[linux-2.6.git] / drivers / net / eql.c
1 /*
2  * Equalizer Load-balancer for serial network interfaces.
3  *
4  * (c) Copyright 1995 Simon "Guru Aleph-Null" Janes
5  * NCM: Network and Communications Management, Inc.
6  *
7  * (c) Copyright 2002 David S. Miller (davem@redhat.com)
8  *
9  *      This software may be used and distributed according to the terms
10  *      of the GNU General Public License, incorporated herein by reference.
11  *
12  * The author may be reached as simon@ncm.com, or C/O
13  *    NCM
14  *    Attn: Simon Janes
15  *    6803 Whittier Ave
16  *    McLean VA 22101
17  *    Phone: 1-703-847-0040 ext 103
18  */
19
20 /*
21  * Sources:
22  *   skeleton.c by Donald Becker.
23  * Inspirations:
24  *   The Harried and Overworked Alan Cox
25  * Conspiracies:
26  *   The Alan Cox and Mike McLagan plot to get someone else to do the code,
27  *   which turned out to be me.
28  */
29
30 /*
31  * $Log: eql.c,v $
32  * Revision 1.2  1996/04/11 17:51:52  guru
33  * Added one-line eql_remove_slave patch.
34  *
35  * Revision 1.1  1996/04/11 17:44:17  guru
36  * Initial revision
37  *
38  * Revision 3.13  1996/01/21  15:17:18  alan
39  * tx_queue_len changes.
40  * reformatted.
41  *
42  * Revision 3.12  1995/03/22  21:07:51  anarchy
43  * Added capable() checks on configuration.
44  * Moved header file.
45  *
46  * Revision 3.11  1995/01/19  23:14:31  guru
47  *                    slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
48  *                      (priority_Bps) + bytes_queued * 8;
49  *
50  * Revision 3.10  1995/01/19  23:07:53  guru
51  * back to
52  *                    slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
53  *                      (priority_Bps) + bytes_queued;
54  *
55  * Revision 3.9  1995/01/19  22:38:20  guru
56  *                    slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
57  *                      (priority_Bps) + bytes_queued * 4;
58  *
59  * Revision 3.8  1995/01/19  22:30:55  guru
60  *       slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
61  *                      (priority_Bps) + bytes_queued * 2;
62  *
63  * Revision 3.7  1995/01/19  21:52:35  guru
64  * printk's trimmed out.
65  *
66  * Revision 3.6  1995/01/19  21:49:56  guru
67  * This is working pretty well. I gained 1 K/s in speed.. now it's just
68  * robustness and printk's to be diked out.
69  *
70  * Revision 3.5  1995/01/18  22:29:59  guru
71  * still crashes the kernel when the lock_wait thing is woken up.
72  *
73  * Revision 3.4  1995/01/18  21:59:47  guru
74  * Broken set-bit locking snapshot
75  *
76  * Revision 3.3  1995/01/17  22:09:18  guru
77  * infinite sleep in a lock somewhere..
78  *
79  * Revision 3.2  1995/01/15  16:46:06  guru
80  * Log trimmed of non-pertinent 1.x branch messages
81  *
82  * Revision 3.1  1995/01/15  14:41:45  guru
83  * New Scheduler and timer stuff...
84  *
85  * Revision 1.15  1995/01/15  14:29:02  guru
86  * Will make 1.14 (now 1.15) the 3.0 branch, and the 1.12 the 2.0 branch, the one
87  * with the dumber scheduler
88  *
89  * Revision 1.14  1995/01/15  02:37:08  guru
90  * shock.. the kept-new-versions could have zonked working
91  * stuff.. shudder
92  *
93  * Revision 1.13  1995/01/15  02:36:31  guru
94  * big changes
95  *
96  *      scheduler was torn out and replaced with something smarter
97  *
98  *      global names not prefixed with eql_ were renamed to protect
99  *      against namespace collisions
100  *
101  *      a few more abstract interfaces were added to facilitate any
102  *      potential change of datastructure.  the driver is still using
103  *      a linked list of slaves.  going to a heap would be a bit of
104  *      an overkill.
105  *
106  *      this compiles fine with no warnings.
107  *
108  *      the locking mechanism and timer stuff must be written however,
109  *      this version will not work otherwise
110  *
111  * Sorry, I had to rewrite most of this for 2.5.x -DaveM
112  */
113
114 #include <linux/module.h>
115 #include <linux/kernel.h>
116 #include <linux/init.h>
117 #include <linux/timer.h>
118 #include <linux/netdevice.h>
119 #include <net/net_namespace.h>
120
121 #include <linux/if.h>
122 #include <linux/if_arp.h>
123 #include <linux/if_eql.h>
124
125 #include <asm/uaccess.h>
126
127 static int eql_open(struct net_device *dev);
128 static int eql_close(struct net_device *dev);
129 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
130 static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);
131
132 #define eql_is_slave(dev)       ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
133 #define eql_is_master(dev)      ((dev->flags & IFF_MASTER) == IFF_MASTER)
134
135 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);
136
137 static void eql_timer(unsigned long param)
138 {
139         equalizer_t *eql = (equalizer_t *) param;
140         struct list_head *this, *tmp, *head;
141
142         spin_lock_bh(&eql->queue.lock);
143         head = &eql->queue.all_slaves;
144         list_for_each_safe(this, tmp, head) {
145                 slave_t *slave = list_entry(this, slave_t, list);
146
147                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
148                         slave->bytes_queued -= slave->priority_Bps;
149                         if (slave->bytes_queued < 0)
150                                 slave->bytes_queued = 0;
151                 } else {
152                         eql_kill_one_slave(&eql->queue, slave);
153                 }
154
155         }
156         spin_unlock_bh(&eql->queue.lock);
157
158         eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
159         add_timer(&eql->timer);
160 }
161
162 static const char version[] __initconst =
163         "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n";
164
165 static const struct net_device_ops eql_netdev_ops = {
166         .ndo_open       = eql_open,
167         .ndo_stop       = eql_close,
168         .ndo_do_ioctl   = eql_ioctl,
169         .ndo_start_xmit = eql_slave_xmit,
170 };
171
172 static void __init eql_setup(struct net_device *dev)
173 {
174         equalizer_t *eql = netdev_priv(dev);
175
176         init_timer(&eql->timer);
177         eql->timer.data         = (unsigned long) eql;
178         eql->timer.expires      = jiffies + EQL_DEFAULT_RESCHED_IVAL;
179         eql->timer.function     = eql_timer;
180
181         spin_lock_init(&eql->queue.lock);
182         INIT_LIST_HEAD(&eql->queue.all_slaves);
183         eql->queue.master_dev   = dev;
184
185         dev->netdev_ops         = &eql_netdev_ops;
186
187         /*
188          *      Now we undo some of the things that eth_setup does
189          *      that we don't like
190          */
191
192         dev->mtu                = EQL_DEFAULT_MTU;      /* set to 576 in if_eql.h */
193         dev->flags              = IFF_MASTER;
194
195         dev->type               = ARPHRD_SLIP;
196         dev->tx_queue_len       = 5;            /* Hands them off fast */
197 }
198
199 static int eql_open(struct net_device *dev)
200 {
201         equalizer_t *eql = netdev_priv(dev);
202
203         /* XXX We should force this off automatically for the user. */
204         printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on "
205                "your slave devices.\n", dev->name);
206
207         BUG_ON(!list_empty(&eql->queue.all_slaves));
208
209         eql->min_slaves = 1;
210         eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
211
212         add_timer(&eql->timer);
213
214         return 0;
215 }
216
217 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
218 {
219         list_del(&slave->list);
220         queue->num_slaves--;
221         slave->dev->flags &= ~IFF_SLAVE;
222         dev_put(slave->dev);
223         kfree(slave);
224 }
225
226 static void eql_kill_slave_queue(slave_queue_t *queue)
227 {
228         struct list_head *head, *tmp, *this;
229
230         spin_lock_bh(&queue->lock);
231
232         head = &queue->all_slaves;
233         list_for_each_safe(this, tmp, head) {
234                 slave_t *s = list_entry(this, slave_t, list);
235
236                 eql_kill_one_slave(queue, s);
237         }
238
239         spin_unlock_bh(&queue->lock);
240 }
241
242 static int eql_close(struct net_device *dev)
243 {
244         equalizer_t *eql = netdev_priv(dev);
245
246         /*
247          *      The timer has to be stopped first before we start hacking away
248          *      at the data structure it scans every so often...
249          */
250
251         del_timer_sync(&eql->timer);
252
253         eql_kill_slave_queue(&eql->queue);
254
255         return 0;
256 }
257
258 static int eql_enslave(struct net_device *dev,  slaving_request_t __user *srq);
259 static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
260
261 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
262 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
263
264 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
265 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
266
267 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
268 {
269         if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
270             !capable(CAP_NET_ADMIN))
271                 return -EPERM;
272
273         switch (cmd) {
274                 case EQL_ENSLAVE:
275                         return eql_enslave(dev, ifr->ifr_data);
276                 case EQL_EMANCIPATE:
277                         return eql_emancipate(dev, ifr->ifr_data);
278                 case EQL_GETSLAVECFG:
279                         return eql_g_slave_cfg(dev, ifr->ifr_data);
280                 case EQL_SETSLAVECFG:
281                         return eql_s_slave_cfg(dev, ifr->ifr_data);
282                 case EQL_GETMASTRCFG:
283                         return eql_g_master_cfg(dev, ifr->ifr_data);
284                 case EQL_SETMASTRCFG:
285                         return eql_s_master_cfg(dev, ifr->ifr_data);
286                 default:
287                         return -EOPNOTSUPP;
288         };
289 }
290
291 /* queue->lock must be held */
292 static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
293 {
294         unsigned long best_load = ~0UL;
295         struct list_head *this, *tmp, *head;
296         slave_t *best_slave;
297
298         best_slave = NULL;
299
300         /* Make a pass to set the best slave. */
301         head = &queue->all_slaves;
302         list_for_each_safe(this, tmp, head) {
303                 slave_t *slave = list_entry(this, slave_t, list);
304                 unsigned long slave_load, bytes_queued, priority_Bps;
305
306                 /* Go through the slave list once, updating best_slave
307                  * whenever a new best_load is found.
308                  */
309                 bytes_queued = slave->bytes_queued;
310                 priority_Bps = slave->priority_Bps;
311                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
312                         slave_load = (~0UL - (~0UL / 2)) -
313                                 (priority_Bps) + bytes_queued * 8;
314
315                         if (slave_load < best_load) {
316                                 best_load = slave_load;
317                                 best_slave = slave;
318                         }
319                 } else {
320                         /* We found a dead slave, kill it. */
321                         eql_kill_one_slave(queue, slave);
322                 }
323         }
324         return best_slave;
325 }
326
327 static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
328 {
329         equalizer_t *eql = netdev_priv(dev);
330         slave_t *slave;
331
332         spin_lock(&eql->queue.lock);
333
334         slave = __eql_schedule_slaves(&eql->queue);
335         if (slave) {
336                 struct net_device *slave_dev = slave->dev;
337
338                 skb->dev = slave_dev;
339                 skb->priority = 1;
340                 slave->bytes_queued += skb->len;
341                 dev_queue_xmit(skb);
342                 dev->stats.tx_packets++;
343         } else {
344                 dev->stats.tx_dropped++;
345                 dev_kfree_skb(skb);
346         }
347
348         spin_unlock(&eql->queue.lock);
349
350         return 0;
351 }
352
353 /*
354  *      Private ioctl functions
355  */
356
357 /* queue->lock must be held */
358 static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
359 {
360         struct list_head *this, *head;
361
362         head = &queue->all_slaves;
363         list_for_each(this, head) {
364                 slave_t *slave = list_entry(this, slave_t, list);
365
366                 if (slave->dev == dev)
367                         return slave;
368         }
369
370         return NULL;
371 }
372
373 static inline int eql_is_full(slave_queue_t *queue)
374 {
375         equalizer_t *eql = netdev_priv(queue->master_dev);
376
377         if (queue->num_slaves >= eql->max_slaves)
378                 return 1;
379         return 0;
380 }
381
382 /* queue->lock must be held */
383 static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
384 {
385         if (!eql_is_full(queue)) {
386                 slave_t *duplicate_slave = NULL;
387
388                 duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
389                 if (duplicate_slave)
390                         eql_kill_one_slave(queue, duplicate_slave);
391
392                 list_add(&slave->list, &queue->all_slaves);
393                 queue->num_slaves++;
394                 slave->dev->flags |= IFF_SLAVE;
395
396                 return 0;
397         }
398
399         return -ENOSPC;
400 }
401
402 static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
403 {
404         struct net_device *slave_dev;
405         slaving_request_t srq;
406
407         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
408                 return -EFAULT;
409
410         slave_dev  = dev_get_by_name(&init_net, srq.slave_name);
411         if (slave_dev) {
412                 if ((master_dev->flags & IFF_UP) == IFF_UP) {
413                         /* slave is not a master & not already a slave: */
414                         if (!eql_is_master(slave_dev) &&
415                             !eql_is_slave(slave_dev)) {
416                                 slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
417                                 equalizer_t *eql = netdev_priv(master_dev);
418                                 int ret;
419
420                                 if (!s) {
421                                         dev_put(slave_dev);
422                                         return -ENOMEM;
423                                 }
424
425                                 memset(s, 0, sizeof(*s));
426                                 s->dev = slave_dev;
427                                 s->priority = srq.priority;
428                                 s->priority_bps = srq.priority;
429                                 s->priority_Bps = srq.priority / 8;
430
431                                 spin_lock_bh(&eql->queue.lock);
432                                 ret = __eql_insert_slave(&eql->queue, s);
433                                 if (ret) {
434                                         dev_put(slave_dev);
435                                         kfree(s);
436                                 }
437                                 spin_unlock_bh(&eql->queue.lock);
438
439                                 return ret;
440                         }
441                 }
442                 dev_put(slave_dev);
443         }
444
445         return -EINVAL;
446 }
447
448 static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
449 {
450         equalizer_t *eql = netdev_priv(master_dev);
451         struct net_device *slave_dev;
452         slaving_request_t srq;
453         int ret;
454
455         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
456                 return -EFAULT;
457
458         slave_dev = dev_get_by_name(&init_net, srq.slave_name);
459         ret = -EINVAL;
460         if (slave_dev) {
461                 spin_lock_bh(&eql->queue.lock);
462
463                 if (eql_is_slave(slave_dev)) {
464                         slave_t *slave = __eql_find_slave_dev(&eql->queue,
465                                                               slave_dev);
466
467                         if (slave) {
468                                 eql_kill_one_slave(&eql->queue, slave);
469                                 ret = 0;
470                         }
471                 }
472                 dev_put(slave_dev);
473
474                 spin_unlock_bh(&eql->queue.lock);
475         }
476
477         return ret;
478 }
479
480 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
481 {
482         equalizer_t *eql = netdev_priv(dev);
483         slave_t *slave;
484         struct net_device *slave_dev;
485         slave_config_t sc;
486         int ret;
487
488         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
489                 return -EFAULT;
490
491         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
492         if (!slave_dev)
493                 return -ENODEV;
494
495         ret = -EINVAL;
496
497         spin_lock_bh(&eql->queue.lock);
498         if (eql_is_slave(slave_dev)) {
499                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
500                 if (slave) {
501                         sc.priority = slave->priority;
502                         ret = 0;
503                 }
504         }
505         spin_unlock_bh(&eql->queue.lock);
506
507         dev_put(slave_dev);
508
509         if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
510                 ret = -EFAULT;
511
512         return ret;
513 }
514
515 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
516 {
517         slave_t *slave;
518         equalizer_t *eql;
519         struct net_device *slave_dev;
520         slave_config_t sc;
521         int ret;
522
523         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
524                 return -EFAULT;
525
526         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
527         if (!slave_dev)
528                 return -ENODEV;
529
530         ret = -EINVAL;
531
532         eql = netdev_priv(dev);
533         spin_lock_bh(&eql->queue.lock);
534         if (eql_is_slave(slave_dev)) {
535                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
536                 if (slave) {
537                         slave->priority = sc.priority;
538                         slave->priority_bps = sc.priority;
539                         slave->priority_Bps = sc.priority / 8;
540                         ret = 0;
541                 }
542         }
543         spin_unlock_bh(&eql->queue.lock);
544
545         dev_put(slave_dev);
546
547         return ret;
548 }
549
550 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
551 {
552         equalizer_t *eql;
553         master_config_t mc;
554
555         if (eql_is_master(dev)) {
556                 eql = netdev_priv(dev);
557                 mc.max_slaves = eql->max_slaves;
558                 mc.min_slaves = eql->min_slaves;
559                 if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
560                         return -EFAULT;
561                 return 0;
562         }
563         return -EINVAL;
564 }
565
566 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
567 {
568         equalizer_t *eql;
569         master_config_t mc;
570
571         if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
572                 return -EFAULT;
573
574         if (eql_is_master(dev)) {
575                 eql = netdev_priv(dev);
576                 eql->max_slaves = mc.max_slaves;
577                 eql->min_slaves = mc.min_slaves;
578                 return 0;
579         }
580         return -EINVAL;
581 }
582
583 static struct net_device *dev_eql;
584
585 static int __init eql_init_module(void)
586 {
587         int err;
588
589         printk(version);
590
591         dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
592         if (!dev_eql)
593                 return -ENOMEM;
594
595         err = register_netdev(dev_eql);
596         if (err)
597                 free_netdev(dev_eql);
598         return err;
599 }
600
601 static void __exit eql_cleanup_module(void)
602 {
603         unregister_netdev(dev_eql);
604         free_netdev(dev_eql);
605 }
606
607 module_init(eql_init_module);
608 module_exit(eql_cleanup_module);
609 MODULE_LICENSE("GPL");