2 * Equalizer Load-balancer for serial network interfaces.
4 * (c) Copyright 1995 Simon "Guru Aleph-Null" Janes
5 * NCM: Network and Communications Management, Inc.
7 * (c) Copyright 2002 David S. Miller (davem@redhat.com)
9 * This software may be used and distributed according to the terms
10 * of the GNU General Public License, incorporated herein by reference.
12 * The author may be reached as simon@ncm.com, or C/O
17 * Phone: 1-703-847-0040 ext 103
22 * skeleton.c by Donald Becker.
24 * The Harried and Overworked Alan Cox
26 * The Alan Cox and Mike McLagan plot to get someone else to do the code,
27 * which turned out to be me.
32 * Revision 1.2 1996/04/11 17:51:52 guru
33 * Added one-line eql_remove_slave patch.
35 * Revision 1.1 1996/04/11 17:44:17 guru
38 * Revision 3.13 1996/01/21 15:17:18 alan
39 * tx_queue_len changes.
42 * Revision 3.12 1995/03/22 21:07:51 anarchy
43 * Added capable() checks on configuration.
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;
50 * Revision 3.10 1995/01/19 23:07:53 guru
52 * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
53 * (priority_Bps) + bytes_queued;
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;
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;
63 * Revision 3.7 1995/01/19 21:52:35 guru
64 * printk's trimmed out.
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.
70 * Revision 3.5 1995/01/18 22:29:59 guru
71 * still crashes the kernel when the lock_wait thing is woken up.
73 * Revision 3.4 1995/01/18 21:59:47 guru
74 * Broken set-bit locking snapshot
76 * Revision 3.3 1995/01/17 22:09:18 guru
77 * infinite sleep in a lock somewhere..
79 * Revision 3.2 1995/01/15 16:46:06 guru
80 * Log trimmed of non-pertinent 1.x branch messages
82 * Revision 3.1 1995/01/15 14:41:45 guru
83 * New Scheduler and timer stuff...
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
89 * Revision 1.14 1995/01/15 02:37:08 guru
90 * shock.. the kept-new-versions could have zonked working
93 * Revision 1.13 1995/01/15 02:36:31 guru
96 * scheduler was torn out and replaced with something smarter
98 * global names not prefixed with eql_ were renamed to protect
99 * against namespace collisions
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
106 * this compiles fine with no warnings.
108 * the locking mechanism and timer stuff must be written however,
109 * this version will not work otherwise
111 * Sorry, I had to rewrite most of this for 2.5.x -DaveM
114 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
116 #include <linux/compat.h>
117 #include <linux/capability.h>
118 #include <linux/module.h>
119 #include <linux/kernel.h>
120 #include <linux/init.h>
121 #include <linux/slab.h>
122 #include <linux/timer.h>
123 #include <linux/netdevice.h>
124 #include <net/net_namespace.h>
126 #include <linux/if.h>
127 #include <linux/if_arp.h>
128 #include <linux/if_eql.h>
129 #include <linux/pkt_sched.h>
131 #include <linux/uaccess.h>
133 static int eql_open(struct net_device *dev);
134 static int eql_close(struct net_device *dev);
135 static int eql_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
136 void __user *data, int cmd);
137 static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);
139 #define eql_is_slave(dev) ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
140 #define eql_is_master(dev) ((dev->flags & IFF_MASTER) == IFF_MASTER)
142 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);
144 static void eql_timer(struct timer_list *t)
146 equalizer_t *eql = from_timer(eql, t, timer);
147 struct list_head *this, *tmp, *head;
149 spin_lock(&eql->queue.lock);
150 head = &eql->queue.all_slaves;
151 list_for_each_safe(this, tmp, head) {
152 slave_t *slave = list_entry(this, slave_t, list);
154 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
155 slave->bytes_queued -= slave->priority_Bps;
156 if (slave->bytes_queued < 0)
157 slave->bytes_queued = 0;
159 eql_kill_one_slave(&eql->queue, slave);
163 spin_unlock(&eql->queue.lock);
165 eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
166 add_timer(&eql->timer);
169 static const char version[] __initconst =
170 "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)";
172 static const struct net_device_ops eql_netdev_ops = {
173 .ndo_open = eql_open,
174 .ndo_stop = eql_close,
175 .ndo_siocdevprivate = eql_siocdevprivate,
176 .ndo_start_xmit = eql_slave_xmit,
179 static void __init eql_setup(struct net_device *dev)
181 equalizer_t *eql = netdev_priv(dev);
183 timer_setup(&eql->timer, eql_timer, 0);
184 eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
186 spin_lock_init(&eql->queue.lock);
187 INIT_LIST_HEAD(&eql->queue.all_slaves);
188 eql->queue.master_dev = dev;
190 dev->netdev_ops = &eql_netdev_ops;
193 * Now we undo some of the things that eth_setup does
197 dev->mtu = EQL_DEFAULT_MTU; /* set to 576 in if_eql.h */
198 dev->flags = IFF_MASTER;
200 dev->type = ARPHRD_SLIP;
201 dev->tx_queue_len = 5; /* Hands them off fast */
205 static int eql_open(struct net_device *dev)
207 equalizer_t *eql = netdev_priv(dev);
209 /* XXX We should force this off automatically for the user. */
211 "remember to turn off Van-Jacobson compression on your slave devices\n");
213 BUG_ON(!list_empty(&eql->queue.all_slaves));
216 eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
218 add_timer(&eql->timer);
223 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
225 list_del(&slave->list);
227 slave->dev->flags &= ~IFF_SLAVE;
228 netdev_put(slave->dev, &slave->dev_tracker);
232 static void eql_kill_slave_queue(slave_queue_t *queue)
234 struct list_head *head, *tmp, *this;
236 spin_lock_bh(&queue->lock);
238 head = &queue->all_slaves;
239 list_for_each_safe(this, tmp, head) {
240 slave_t *s = list_entry(this, slave_t, list);
242 eql_kill_one_slave(queue, s);
245 spin_unlock_bh(&queue->lock);
248 static int eql_close(struct net_device *dev)
250 equalizer_t *eql = netdev_priv(dev);
253 * The timer has to be stopped first before we start hacking away
254 * at the data structure it scans every so often...
257 del_timer_sync(&eql->timer);
259 eql_kill_slave_queue(&eql->queue);
264 static int eql_enslave(struct net_device *dev, slaving_request_t __user *srq);
265 static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
267 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
268 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
270 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
271 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
273 static int eql_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
274 void __user *data, int cmd)
276 if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
277 !capable(CAP_NET_ADMIN))
280 if (in_compat_syscall()) /* to be implemented */
285 return eql_enslave(dev, data);
287 return eql_emancipate(dev, data);
288 case EQL_GETSLAVECFG:
289 return eql_g_slave_cfg(dev, data);
290 case EQL_SETSLAVECFG:
291 return eql_s_slave_cfg(dev, data);
292 case EQL_GETMASTRCFG:
293 return eql_g_master_cfg(dev, data);
294 case EQL_SETMASTRCFG:
295 return eql_s_master_cfg(dev, data);
301 /* queue->lock must be held */
302 static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
304 unsigned long best_load = ~0UL;
305 struct list_head *this, *tmp, *head;
310 /* Make a pass to set the best slave. */
311 head = &queue->all_slaves;
312 list_for_each_safe(this, tmp, head) {
313 slave_t *slave = list_entry(this, slave_t, list);
314 unsigned long slave_load, bytes_queued, priority_Bps;
316 /* Go through the slave list once, updating best_slave
317 * whenever a new best_load is found.
319 bytes_queued = slave->bytes_queued;
320 priority_Bps = slave->priority_Bps;
321 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
322 slave_load = (~0UL - (~0UL / 2)) -
323 (priority_Bps) + bytes_queued * 8;
325 if (slave_load < best_load) {
326 best_load = slave_load;
330 /* We found a dead slave, kill it. */
331 eql_kill_one_slave(queue, slave);
337 static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
339 equalizer_t *eql = netdev_priv(dev);
342 spin_lock(&eql->queue.lock);
344 slave = __eql_schedule_slaves(&eql->queue);
346 struct net_device *slave_dev = slave->dev;
348 skb->dev = slave_dev;
349 skb->priority = TC_PRIO_FILLER;
350 slave->bytes_queued += skb->len;
352 dev->stats.tx_packets++;
354 dev->stats.tx_dropped++;
358 spin_unlock(&eql->queue.lock);
364 * Private ioctl functions
367 /* queue->lock must be held */
368 static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
370 struct list_head *this, *head;
372 head = &queue->all_slaves;
373 list_for_each(this, head) {
374 slave_t *slave = list_entry(this, slave_t, list);
376 if (slave->dev == dev)
383 static inline int eql_is_full(slave_queue_t *queue)
385 equalizer_t *eql = netdev_priv(queue->master_dev);
387 if (queue->num_slaves >= eql->max_slaves)
392 /* queue->lock must be held */
393 static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
395 if (!eql_is_full(queue)) {
396 slave_t *duplicate_slave = NULL;
398 duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
400 eql_kill_one_slave(queue, duplicate_slave);
402 netdev_hold(slave->dev, &slave->dev_tracker, GFP_ATOMIC);
403 list_add(&slave->list, &queue->all_slaves);
405 slave->dev->flags |= IFF_SLAVE;
413 static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
415 struct net_device *slave_dev;
416 slaving_request_t srq;
418 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
421 slave_dev = __dev_get_by_name(&init_net, srq.slave_name);
425 if ((master_dev->flags & IFF_UP) == IFF_UP) {
426 /* slave is not a master & not already a slave: */
427 if (!eql_is_master(slave_dev) && !eql_is_slave(slave_dev)) {
428 slave_t *s = kzalloc(sizeof(*s), GFP_KERNEL);
429 equalizer_t *eql = netdev_priv(master_dev);
436 s->priority = srq.priority;
437 s->priority_bps = srq.priority;
438 s->priority_Bps = srq.priority / 8;
440 spin_lock_bh(&eql->queue.lock);
441 ret = __eql_insert_slave(&eql->queue, s);
445 spin_unlock_bh(&eql->queue.lock);
454 static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
456 equalizer_t *eql = netdev_priv(master_dev);
457 struct net_device *slave_dev;
458 slaving_request_t srq;
461 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
464 slave_dev = __dev_get_by_name(&init_net, srq.slave_name);
469 spin_lock_bh(&eql->queue.lock);
470 if (eql_is_slave(slave_dev)) {
471 slave_t *slave = __eql_find_slave_dev(&eql->queue, slave_dev);
473 eql_kill_one_slave(&eql->queue, slave);
477 spin_unlock_bh(&eql->queue.lock);
482 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
484 equalizer_t *eql = netdev_priv(dev);
486 struct net_device *slave_dev;
490 if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
493 slave_dev = __dev_get_by_name(&init_net, sc.slave_name);
499 spin_lock_bh(&eql->queue.lock);
500 if (eql_is_slave(slave_dev)) {
501 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
503 sc.priority = slave->priority;
507 spin_unlock_bh(&eql->queue.lock);
509 if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
515 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
519 struct net_device *slave_dev;
523 if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
526 slave_dev = __dev_get_by_name(&init_net, sc.slave_name);
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);
537 slave->priority = sc.priority;
538 slave->priority_bps = sc.priority;
539 slave->priority_Bps = sc.priority / 8;
543 spin_unlock_bh(&eql->queue.lock);
548 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
553 memset(&mc, 0, sizeof(master_config_t));
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)))
566 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
571 if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
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;
583 static struct net_device *dev_eql;
585 static int __init eql_init_module(void)
589 pr_info("%s\n", version);
591 dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", NET_NAME_UNKNOWN,
596 err = register_netdev(dev_eql);
598 free_netdev(dev_eql);
602 static void __exit eql_cleanup_module(void)
604 unregister_netdev(dev_eql);
605 free_netdev(dev_eql);
608 module_init(eql_init_module);
609 module_exit(eql_cleanup_module);
610 MODULE_LICENSE("GPL");