Root/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
127static int eql_open(struct net_device *dev);
128static int eql_close(struct net_device *dev);
129static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
130static 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
135static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);
136
137static 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
162static const char version[] __initconst =
163    "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n";
164
165static 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
172static 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    dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
198}
199
200static int eql_open(struct net_device *dev)
201{
202    equalizer_t *eql = netdev_priv(dev);
203
204    /* XXX We should force this off automatically for the user. */
205    printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on "
206           "your slave devices.\n", dev->name);
207
208    BUG_ON(!list_empty(&eql->queue.all_slaves));
209
210    eql->min_slaves = 1;
211    eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
212
213    add_timer(&eql->timer);
214
215    return 0;
216}
217
218static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
219{
220    list_del(&slave->list);
221    queue->num_slaves--;
222    slave->dev->flags &= ~IFF_SLAVE;
223    dev_put(slave->dev);
224    kfree(slave);
225}
226
227static void eql_kill_slave_queue(slave_queue_t *queue)
228{
229    struct list_head *head, *tmp, *this;
230
231    spin_lock_bh(&queue->lock);
232
233    head = &queue->all_slaves;
234    list_for_each_safe(this, tmp, head) {
235        slave_t *s = list_entry(this, slave_t, list);
236
237        eql_kill_one_slave(queue, s);
238    }
239
240    spin_unlock_bh(&queue->lock);
241}
242
243static int eql_close(struct net_device *dev)
244{
245    equalizer_t *eql = netdev_priv(dev);
246
247    /*
248     * The timer has to be stopped first before we start hacking away
249     * at the data structure it scans every so often...
250     */
251
252    del_timer_sync(&eql->timer);
253
254    eql_kill_slave_queue(&eql->queue);
255
256    return 0;
257}
258
259static int eql_enslave(struct net_device *dev, slaving_request_t __user *srq);
260static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
261
262static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
263static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
264
265static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
266static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
267
268static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
269{
270    if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
271        !capable(CAP_NET_ADMIN))
272          return -EPERM;
273
274    switch (cmd) {
275        case EQL_ENSLAVE:
276            return eql_enslave(dev, ifr->ifr_data);
277        case EQL_EMANCIPATE:
278            return eql_emancipate(dev, ifr->ifr_data);
279        case EQL_GETSLAVECFG:
280            return eql_g_slave_cfg(dev, ifr->ifr_data);
281        case EQL_SETSLAVECFG:
282            return eql_s_slave_cfg(dev, ifr->ifr_data);
283        case EQL_GETMASTRCFG:
284            return eql_g_master_cfg(dev, ifr->ifr_data);
285        case EQL_SETMASTRCFG:
286            return eql_s_master_cfg(dev, ifr->ifr_data);
287        default:
288            return -EOPNOTSUPP;
289    };
290}
291
292/* queue->lock must be held */
293static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
294{
295    unsigned long best_load = ~0UL;
296    struct list_head *this, *tmp, *head;
297    slave_t *best_slave;
298
299    best_slave = NULL;
300
301    /* Make a pass to set the best slave. */
302    head = &queue->all_slaves;
303    list_for_each_safe(this, tmp, head) {
304        slave_t *slave = list_entry(this, slave_t, list);
305        unsigned long slave_load, bytes_queued, priority_Bps;
306
307        /* Go through the slave list once, updating best_slave
308         * whenever a new best_load is found.
309         */
310        bytes_queued = slave->bytes_queued;
311        priority_Bps = slave->priority_Bps;
312        if ((slave->dev->flags & IFF_UP) == IFF_UP) {
313            slave_load = (~0UL - (~0UL / 2)) -
314                (priority_Bps) + bytes_queued * 8;
315
316            if (slave_load < best_load) {
317                best_load = slave_load;
318                best_slave = slave;
319            }
320        } else {
321            /* We found a dead slave, kill it. */
322            eql_kill_one_slave(queue, slave);
323        }
324    }
325    return best_slave;
326}
327
328static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
329{
330    equalizer_t *eql = netdev_priv(dev);
331    slave_t *slave;
332
333    spin_lock(&eql->queue.lock);
334
335    slave = __eql_schedule_slaves(&eql->queue);
336    if (slave) {
337        struct net_device *slave_dev = slave->dev;
338
339        skb->dev = slave_dev;
340        skb->priority = 1;
341        slave->bytes_queued += skb->len;
342        dev_queue_xmit(skb);
343        dev->stats.tx_packets++;
344    } else {
345        dev->stats.tx_dropped++;
346        dev_kfree_skb(skb);
347    }
348
349    spin_unlock(&eql->queue.lock);
350
351    return 0;
352}
353
354/*
355 * Private ioctl functions
356 */
357
358/* queue->lock must be held */
359static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
360{
361    struct list_head *this, *head;
362
363    head = &queue->all_slaves;
364    list_for_each(this, head) {
365        slave_t *slave = list_entry(this, slave_t, list);
366
367        if (slave->dev == dev)
368            return slave;
369    }
370
371    return NULL;
372}
373
374static inline int eql_is_full(slave_queue_t *queue)
375{
376    equalizer_t *eql = netdev_priv(queue->master_dev);
377
378    if (queue->num_slaves >= eql->max_slaves)
379        return 1;
380    return 0;
381}
382
383/* queue->lock must be held */
384static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
385{
386    if (!eql_is_full(queue)) {
387        slave_t *duplicate_slave = NULL;
388
389        duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
390        if (duplicate_slave)
391            eql_kill_one_slave(queue, duplicate_slave);
392
393        list_add(&slave->list, &queue->all_slaves);
394        queue->num_slaves++;
395        slave->dev->flags |= IFF_SLAVE;
396
397        return 0;
398    }
399
400    return -ENOSPC;
401}
402
403static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
404{
405    struct net_device *slave_dev;
406    slaving_request_t srq;
407
408    if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
409        return -EFAULT;
410
411    slave_dev = dev_get_by_name(&init_net, srq.slave_name);
412    if (slave_dev) {
413        if ((master_dev->flags & IFF_UP) == IFF_UP) {
414            /* slave is not a master & not already a slave: */
415            if (!eql_is_master(slave_dev) &&
416                !eql_is_slave(slave_dev)) {
417                slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
418                equalizer_t *eql = netdev_priv(master_dev);
419                int ret;
420
421                if (!s) {
422                    dev_put(slave_dev);
423                    return -ENOMEM;
424                }
425
426                memset(s, 0, sizeof(*s));
427                s->dev = slave_dev;
428                s->priority = srq.priority;
429                s->priority_bps = srq.priority;
430                s->priority_Bps = srq.priority / 8;
431
432                spin_lock_bh(&eql->queue.lock);
433                ret = __eql_insert_slave(&eql->queue, s);
434                if (ret) {
435                    dev_put(slave_dev);
436                    kfree(s);
437                }
438                spin_unlock_bh(&eql->queue.lock);
439
440                return ret;
441            }
442        }
443        dev_put(slave_dev);
444    }
445
446    return -EINVAL;
447}
448
449static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
450{
451    equalizer_t *eql = netdev_priv(master_dev);
452    struct net_device *slave_dev;
453    slaving_request_t srq;
454    int ret;
455
456    if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
457        return -EFAULT;
458
459    slave_dev = dev_get_by_name(&init_net, srq.slave_name);
460    ret = -EINVAL;
461    if (slave_dev) {
462        spin_lock_bh(&eql->queue.lock);
463
464        if (eql_is_slave(slave_dev)) {
465            slave_t *slave = __eql_find_slave_dev(&eql->queue,
466                                  slave_dev);
467
468            if (slave) {
469                eql_kill_one_slave(&eql->queue, slave);
470                ret = 0;
471            }
472        }
473        dev_put(slave_dev);
474
475        spin_unlock_bh(&eql->queue.lock);
476    }
477
478    return ret;
479}
480
481static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
482{
483    equalizer_t *eql = netdev_priv(dev);
484    slave_t *slave;
485    struct net_device *slave_dev;
486    slave_config_t sc;
487    int ret;
488
489    if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
490        return -EFAULT;
491
492    slave_dev = dev_get_by_name(&init_net, sc.slave_name);
493    if (!slave_dev)
494        return -ENODEV;
495
496    ret = -EINVAL;
497
498    spin_lock_bh(&eql->queue.lock);
499    if (eql_is_slave(slave_dev)) {
500        slave = __eql_find_slave_dev(&eql->queue, slave_dev);
501        if (slave) {
502            sc.priority = slave->priority;
503            ret = 0;
504        }
505    }
506    spin_unlock_bh(&eql->queue.lock);
507
508    dev_put(slave_dev);
509
510    if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
511        ret = -EFAULT;
512
513    return ret;
514}
515
516static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
517{
518    slave_t *slave;
519    equalizer_t *eql;
520    struct net_device *slave_dev;
521    slave_config_t sc;
522    int ret;
523
524    if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
525        return -EFAULT;
526
527    slave_dev = dev_get_by_name(&init_net, sc.slave_name);
528    if (!slave_dev)
529        return -ENODEV;
530
531    ret = -EINVAL;
532
533    eql = netdev_priv(dev);
534    spin_lock_bh(&eql->queue.lock);
535    if (eql_is_slave(slave_dev)) {
536        slave = __eql_find_slave_dev(&eql->queue, slave_dev);
537        if (slave) {
538            slave->priority = sc.priority;
539            slave->priority_bps = sc.priority;
540            slave->priority_Bps = sc.priority / 8;
541            ret = 0;
542        }
543    }
544    spin_unlock_bh(&eql->queue.lock);
545
546    dev_put(slave_dev);
547
548    return ret;
549}
550
551static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
552{
553    equalizer_t *eql;
554    master_config_t mc;
555
556    if (eql_is_master(dev)) {
557        eql = netdev_priv(dev);
558        mc.max_slaves = eql->max_slaves;
559        mc.min_slaves = eql->min_slaves;
560        if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
561            return -EFAULT;
562        return 0;
563    }
564    return -EINVAL;
565}
566
567static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
568{
569    equalizer_t *eql;
570    master_config_t mc;
571
572    if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
573        return -EFAULT;
574
575    if (eql_is_master(dev)) {
576        eql = netdev_priv(dev);
577        eql->max_slaves = mc.max_slaves;
578        eql->min_slaves = mc.min_slaves;
579        return 0;
580    }
581    return -EINVAL;
582}
583
584static struct net_device *dev_eql;
585
586static int __init eql_init_module(void)
587{
588    int err;
589
590    printk(version);
591
592    dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
593    if (!dev_eql)
594        return -ENOMEM;
595
596    err = register_netdev(dev_eql);
597    if (err)
598        free_netdev(dev_eql);
599    return err;
600}
601
602static void __exit eql_cleanup_module(void)
603{
604    unregister_netdev(dev_eql);
605    free_netdev(dev_eql);
606}
607
608module_init(eql_init_module);
609module_exit(eql_cleanup_module);
610MODULE_LICENSE("GPL");
611

Archive Download this file

Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.2
jz-3.3
jz-3.4
jz47xx
jz47xx-2.6.38
master
xiangfu/openwrt/v3.0.0
xiangfu/openwrt/v3.2.1

Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7



interactive