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_DESCRIPTION("Equalizer Load-balancer for serial network interfaces");
611 MODULE_LICENSE("GPL");