Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* net/sched/sch_teql.c "True" (or "trivial") link equalizer. |
2 | * | |
3 | * This program is free software; you can redistribute it and/or | |
4 | * modify it under the terms of the GNU General Public License | |
5 | * as published by the Free Software Foundation; either version | |
6 | * 2 of the License, or (at your option) any later version. | |
7 | * | |
8 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> | |
9 | */ | |
10 | ||
11 | #include <linux/module.h> | |
12 | #include <asm/uaccess.h> | |
13 | #include <asm/system.h> | |
14 | #include <linux/bitops.h> | |
15 | #include <linux/types.h> | |
16 | #include <linux/kernel.h> | |
1da177e4 LT |
17 | #include <linux/string.h> |
18 | #include <linux/mm.h> | |
19 | #include <linux/socket.h> | |
20 | #include <linux/sockios.h> | |
21 | #include <linux/in.h> | |
22 | #include <linux/errno.h> | |
23 | #include <linux/interrupt.h> | |
14c85021 | 24 | #include <linux/if_arp.h> |
1da177e4 LT |
25 | #include <linux/if_ether.h> |
26 | #include <linux/inet.h> | |
27 | #include <linux/netdevice.h> | |
28 | #include <linux/etherdevice.h> | |
29 | #include <linux/notifier.h> | |
30 | #include <linux/init.h> | |
31 | #include <net/ip.h> | |
32 | #include <net/route.h> | |
33 | #include <linux/skbuff.h> | |
34 | #include <linux/moduleparam.h> | |
35 | #include <net/sock.h> | |
36 | #include <net/pkt_sched.h> | |
37 | ||
38 | /* | |
39 | How to setup it. | |
40 | ---------------- | |
41 | ||
42 | After loading this module you will find a new device teqlN | |
43 | and new qdisc with the same name. To join a slave to the equalizer | |
44 | you should just set this qdisc on a device f.e. | |
45 | ||
46 | # tc qdisc add dev eth0 root teql0 | |
47 | # tc qdisc add dev eth1 root teql0 | |
48 | ||
49 | That's all. Full PnP 8) | |
50 | ||
51 | Applicability. | |
52 | -------------- | |
53 | ||
54 | 1. Slave devices MUST be active devices, i.e., they must raise the tbusy | |
55 | signal and generate EOI events. If you want to equalize virtual devices | |
56 | like tunnels, use a normal eql device. | |
57 | 2. This device puts no limitations on physical slave characteristics | |
58 | f.e. it will equalize 9600baud line and 100Mb ethernet perfectly :-) | |
59 | Certainly, large difference in link speeds will make the resulting | |
60 | eqalized link unusable, because of huge packet reordering. | |
61 | I estimate an upper useful difference as ~10 times. | |
62 | 3. If the slave requires address resolution, only protocols using | |
63 | neighbour cache (IPv4/IPv6) will work over the equalized link. | |
64 | Other protocols are still allowed to use the slave device directly, | |
65 | which will not break load balancing, though native slave | |
66 | traffic will have the highest priority. */ | |
67 | ||
68 | struct teql_master | |
69 | { | |
70 | struct Qdisc_ops qops; | |
71 | struct net_device *dev; | |
72 | struct Qdisc *slaves; | |
73 | struct list_head master_list; | |
74 | struct net_device_stats stats; | |
75 | }; | |
76 | ||
77 | struct teql_sched_data | |
78 | { | |
79 | struct Qdisc *next; | |
80 | struct teql_master *m; | |
81 | struct neighbour *ncache; | |
82 | struct sk_buff_head q; | |
83 | }; | |
84 | ||
85 | #define NEXT_SLAVE(q) (((struct teql_sched_data*)qdisc_priv(q))->next) | |
86 | ||
87 | #define FMASK (IFF_BROADCAST|IFF_POINTOPOINT|IFF_BROADCAST) | |
88 | ||
89 | /* "teql*" qdisc routines */ | |
90 | ||
91 | static int | |
92 | teql_enqueue(struct sk_buff *skb, struct Qdisc* sch) | |
93 | { | |
94 | struct net_device *dev = sch->dev; | |
95 | struct teql_sched_data *q = qdisc_priv(sch); | |
96 | ||
4cd8c9e8 KK |
97 | if (q->q.qlen < dev->tx_queue_len) { |
98 | __skb_queue_tail(&q->q, skb); | |
1da177e4 LT |
99 | sch->bstats.bytes += skb->len; |
100 | sch->bstats.packets++; | |
101 | return 0; | |
102 | } | |
103 | ||
1da177e4 LT |
104 | kfree_skb(skb); |
105 | sch->qstats.drops++; | |
106 | return NET_XMIT_DROP; | |
107 | } | |
108 | ||
109 | static int | |
110 | teql_requeue(struct sk_buff *skb, struct Qdisc* sch) | |
111 | { | |
112 | struct teql_sched_data *q = qdisc_priv(sch); | |
113 | ||
114 | __skb_queue_head(&q->q, skb); | |
115 | sch->qstats.requeues++; | |
116 | return 0; | |
117 | } | |
118 | ||
119 | static struct sk_buff * | |
120 | teql_dequeue(struct Qdisc* sch) | |
121 | { | |
122 | struct teql_sched_data *dat = qdisc_priv(sch); | |
123 | struct sk_buff *skb; | |
124 | ||
125 | skb = __skb_dequeue(&dat->q); | |
126 | if (skb == NULL) { | |
127 | struct net_device *m = dat->m->dev->qdisc->dev; | |
128 | if (m) { | |
129 | dat->m->slaves = sch; | |
130 | netif_wake_queue(m); | |
131 | } | |
132 | } | |
133 | sch->q.qlen = dat->q.qlen + dat->m->dev->qdisc->q.qlen; | |
134 | return skb; | |
135 | } | |
136 | ||
137 | static __inline__ void | |
138 | teql_neigh_release(struct neighbour *n) | |
139 | { | |
140 | if (n) | |
141 | neigh_release(n); | |
142 | } | |
143 | ||
144 | static void | |
145 | teql_reset(struct Qdisc* sch) | |
146 | { | |
147 | struct teql_sched_data *dat = qdisc_priv(sch); | |
148 | ||
149 | skb_queue_purge(&dat->q); | |
150 | sch->q.qlen = 0; | |
151 | teql_neigh_release(xchg(&dat->ncache, NULL)); | |
152 | } | |
153 | ||
154 | static void | |
155 | teql_destroy(struct Qdisc* sch) | |
156 | { | |
157 | struct Qdisc *q, *prev; | |
158 | struct teql_sched_data *dat = qdisc_priv(sch); | |
159 | struct teql_master *master = dat->m; | |
160 | ||
161 | if ((prev = master->slaves) != NULL) { | |
162 | do { | |
163 | q = NEXT_SLAVE(prev); | |
164 | if (q == sch) { | |
165 | NEXT_SLAVE(prev) = NEXT_SLAVE(q); | |
166 | if (q == master->slaves) { | |
167 | master->slaves = NEXT_SLAVE(q); | |
168 | if (q == master->slaves) { | |
169 | master->slaves = NULL; | |
170 | spin_lock_bh(&master->dev->queue_lock); | |
171 | qdisc_reset(master->dev->qdisc); | |
172 | spin_unlock_bh(&master->dev->queue_lock); | |
173 | } | |
174 | } | |
175 | skb_queue_purge(&dat->q); | |
176 | teql_neigh_release(xchg(&dat->ncache, NULL)); | |
177 | break; | |
178 | } | |
10297b99 | 179 | |
1da177e4 LT |
180 | } while ((prev = q) != master->slaves); |
181 | } | |
182 | } | |
183 | ||
184 | static int teql_qdisc_init(struct Qdisc *sch, struct rtattr *opt) | |
185 | { | |
186 | struct net_device *dev = sch->dev; | |
187 | struct teql_master *m = (struct teql_master*)sch->ops; | |
188 | struct teql_sched_data *q = qdisc_priv(sch); | |
189 | ||
190 | if (dev->hard_header_len > m->dev->hard_header_len) | |
191 | return -EINVAL; | |
192 | ||
193 | if (m->dev == dev) | |
194 | return -ELOOP; | |
195 | ||
196 | q->m = m; | |
197 | ||
198 | skb_queue_head_init(&q->q); | |
199 | ||
200 | if (m->slaves) { | |
201 | if (m->dev->flags & IFF_UP) { | |
202 | if ((m->dev->flags&IFF_POINTOPOINT && !(dev->flags&IFF_POINTOPOINT)) | |
203 | || (m->dev->flags&IFF_BROADCAST && !(dev->flags&IFF_BROADCAST)) | |
204 | || (m->dev->flags&IFF_MULTICAST && !(dev->flags&IFF_MULTICAST)) | |
205 | || dev->mtu < m->dev->mtu) | |
206 | return -EINVAL; | |
207 | } else { | |
208 | if (!(dev->flags&IFF_POINTOPOINT)) | |
209 | m->dev->flags &= ~IFF_POINTOPOINT; | |
210 | if (!(dev->flags&IFF_BROADCAST)) | |
211 | m->dev->flags &= ~IFF_BROADCAST; | |
212 | if (!(dev->flags&IFF_MULTICAST)) | |
213 | m->dev->flags &= ~IFF_MULTICAST; | |
214 | if (dev->mtu < m->dev->mtu) | |
215 | m->dev->mtu = dev->mtu; | |
216 | } | |
217 | q->next = NEXT_SLAVE(m->slaves); | |
218 | NEXT_SLAVE(m->slaves) = sch; | |
219 | } else { | |
220 | q->next = sch; | |
221 | m->slaves = sch; | |
222 | m->dev->mtu = dev->mtu; | |
223 | m->dev->flags = (m->dev->flags&~FMASK)|(dev->flags&FMASK); | |
224 | } | |
225 | return 0; | |
226 | } | |
227 | ||
228 | /* "teql*" netdevice routines */ | |
229 | ||
230 | static int | |
231 | __teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res, struct net_device *dev) | |
232 | { | |
233 | struct teql_sched_data *q = qdisc_priv(dev->qdisc); | |
234 | struct neighbour *mn = skb->dst->neighbour; | |
235 | struct neighbour *n = q->ncache; | |
236 | ||
237 | if (mn->tbl == NULL) | |
238 | return -EINVAL; | |
239 | if (n && n->tbl == mn->tbl && | |
240 | memcmp(n->primary_key, mn->primary_key, mn->tbl->key_len) == 0) { | |
241 | atomic_inc(&n->refcnt); | |
242 | } else { | |
243 | n = __neigh_lookup_errno(mn->tbl, mn->primary_key, dev); | |
244 | if (IS_ERR(n)) | |
245 | return PTR_ERR(n); | |
246 | } | |
247 | if (neigh_event_send(n, skb_res) == 0) { | |
248 | int err; | |
249 | read_lock(&n->lock); | |
250 | err = dev->hard_header(skb, dev, ntohs(skb->protocol), n->ha, NULL, skb->len); | |
251 | read_unlock(&n->lock); | |
252 | if (err < 0) { | |
253 | neigh_release(n); | |
254 | return -EINVAL; | |
255 | } | |
256 | teql_neigh_release(xchg(&q->ncache, n)); | |
257 | return 0; | |
258 | } | |
259 | neigh_release(n); | |
260 | return (skb_res == NULL) ? -EAGAIN : 1; | |
261 | } | |
262 | ||
263 | static __inline__ int | |
264 | teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res, struct net_device *dev) | |
265 | { | |
266 | if (dev->hard_header == NULL || | |
267 | skb->dst == NULL || | |
268 | skb->dst->neighbour == NULL) | |
269 | return 0; | |
270 | return __teql_resolve(skb, skb_res, dev); | |
271 | } | |
272 | ||
273 | static int teql_master_xmit(struct sk_buff *skb, struct net_device *dev) | |
274 | { | |
2941a486 | 275 | struct teql_master *master = netdev_priv(dev); |
1da177e4 LT |
276 | struct Qdisc *start, *q; |
277 | int busy; | |
278 | int nores; | |
279 | int len = skb->len; | |
280 | struct sk_buff *skb_res = NULL; | |
281 | ||
282 | start = master->slaves; | |
283 | ||
284 | restart: | |
285 | nores = 0; | |
286 | busy = 0; | |
287 | ||
288 | if ((q = start) == NULL) | |
289 | goto drop; | |
290 | ||
291 | do { | |
292 | struct net_device *slave = q->dev; | |
10297b99 | 293 | |
1da177e4 LT |
294 | if (slave->qdisc_sleeping != q) |
295 | continue; | |
296 | if (netif_queue_stopped(slave) || ! netif_running(slave)) { | |
297 | busy = 1; | |
298 | continue; | |
299 | } | |
300 | ||
301 | switch (teql_resolve(skb, skb_res, slave)) { | |
302 | case 0: | |
932ff279 | 303 | if (netif_tx_trylock(slave)) { |
1da177e4 LT |
304 | if (!netif_queue_stopped(slave) && |
305 | slave->hard_start_xmit(skb, slave) == 0) { | |
932ff279 | 306 | netif_tx_unlock(slave); |
1da177e4 LT |
307 | master->slaves = NEXT_SLAVE(q); |
308 | netif_wake_queue(dev); | |
309 | master->stats.tx_packets++; | |
310 | master->stats.tx_bytes += len; | |
311 | return 0; | |
312 | } | |
932ff279 | 313 | netif_tx_unlock(slave); |
1da177e4 LT |
314 | } |
315 | if (netif_queue_stopped(dev)) | |
316 | busy = 1; | |
317 | break; | |
318 | case 1: | |
319 | master->slaves = NEXT_SLAVE(q); | |
320 | return 0; | |
321 | default: | |
322 | nores = 1; | |
323 | break; | |
324 | } | |
bbe735e4 | 325 | __skb_pull(skb, skb_network_offset(skb)); |
1da177e4 LT |
326 | } while ((q = NEXT_SLAVE(q)) != start); |
327 | ||
328 | if (nores && skb_res == NULL) { | |
329 | skb_res = skb; | |
330 | goto restart; | |
331 | } | |
332 | ||
333 | if (busy) { | |
334 | netif_stop_queue(dev); | |
335 | return 1; | |
336 | } | |
337 | master->stats.tx_errors++; | |
338 | ||
339 | drop: | |
340 | master->stats.tx_dropped++; | |
341 | dev_kfree_skb(skb); | |
342 | return 0; | |
343 | } | |
344 | ||
345 | static int teql_master_open(struct net_device *dev) | |
346 | { | |
347 | struct Qdisc * q; | |
2941a486 | 348 | struct teql_master *m = netdev_priv(dev); |
1da177e4 LT |
349 | int mtu = 0xFFFE; |
350 | unsigned flags = IFF_NOARP|IFF_MULTICAST; | |
351 | ||
352 | if (m->slaves == NULL) | |
353 | return -EUNATCH; | |
354 | ||
355 | flags = FMASK; | |
356 | ||
357 | q = m->slaves; | |
358 | do { | |
359 | struct net_device *slave = q->dev; | |
360 | ||
361 | if (slave == NULL) | |
362 | return -EUNATCH; | |
363 | ||
364 | if (slave->mtu < mtu) | |
365 | mtu = slave->mtu; | |
366 | if (slave->hard_header_len > LL_MAX_HEADER) | |
367 | return -EINVAL; | |
368 | ||
369 | /* If all the slaves are BROADCAST, master is BROADCAST | |
370 | If all the slaves are PtP, master is PtP | |
371 | Otherwise, master is NBMA. | |
372 | */ | |
373 | if (!(slave->flags&IFF_POINTOPOINT)) | |
374 | flags &= ~IFF_POINTOPOINT; | |
375 | if (!(slave->flags&IFF_BROADCAST)) | |
376 | flags &= ~IFF_BROADCAST; | |
377 | if (!(slave->flags&IFF_MULTICAST)) | |
378 | flags &= ~IFF_MULTICAST; | |
379 | } while ((q = NEXT_SLAVE(q)) != m->slaves); | |
380 | ||
381 | m->dev->mtu = mtu; | |
382 | m->dev->flags = (m->dev->flags&~FMASK) | flags; | |
383 | netif_start_queue(m->dev); | |
384 | return 0; | |
385 | } | |
386 | ||
387 | static int teql_master_close(struct net_device *dev) | |
388 | { | |
389 | netif_stop_queue(dev); | |
390 | return 0; | |
391 | } | |
392 | ||
393 | static struct net_device_stats *teql_master_stats(struct net_device *dev) | |
394 | { | |
2941a486 | 395 | struct teql_master *m = netdev_priv(dev); |
1da177e4 LT |
396 | return &m->stats; |
397 | } | |
398 | ||
399 | static int teql_master_mtu(struct net_device *dev, int new_mtu) | |
400 | { | |
2941a486 | 401 | struct teql_master *m = netdev_priv(dev); |
1da177e4 LT |
402 | struct Qdisc *q; |
403 | ||
404 | if (new_mtu < 68) | |
405 | return -EINVAL; | |
406 | ||
407 | q = m->slaves; | |
408 | if (q) { | |
409 | do { | |
410 | if (new_mtu > q->dev->mtu) | |
411 | return -EINVAL; | |
412 | } while ((q=NEXT_SLAVE(q)) != m->slaves); | |
413 | } | |
414 | ||
415 | dev->mtu = new_mtu; | |
416 | return 0; | |
417 | } | |
418 | ||
419 | static __init void teql_master_setup(struct net_device *dev) | |
420 | { | |
2941a486 | 421 | struct teql_master *master = netdev_priv(dev); |
1da177e4 LT |
422 | struct Qdisc_ops *ops = &master->qops; |
423 | ||
424 | master->dev = dev; | |
425 | ops->priv_size = sizeof(struct teql_sched_data); | |
10297b99 | 426 | |
1da177e4 LT |
427 | ops->enqueue = teql_enqueue; |
428 | ops->dequeue = teql_dequeue; | |
429 | ops->requeue = teql_requeue; | |
430 | ops->init = teql_qdisc_init; | |
431 | ops->reset = teql_reset; | |
432 | ops->destroy = teql_destroy; | |
433 | ops->owner = THIS_MODULE; | |
434 | ||
435 | dev->open = teql_master_open; | |
436 | dev->hard_start_xmit = teql_master_xmit; | |
437 | dev->stop = teql_master_close; | |
438 | dev->get_stats = teql_master_stats; | |
439 | dev->change_mtu = teql_master_mtu; | |
440 | dev->type = ARPHRD_VOID; | |
441 | dev->mtu = 1500; | |
442 | dev->tx_queue_len = 100; | |
443 | dev->flags = IFF_NOARP; | |
444 | dev->hard_header_len = LL_MAX_HEADER; | |
445 | SET_MODULE_OWNER(dev); | |
446 | } | |
447 | ||
448 | static LIST_HEAD(master_dev_list); | |
449 | static int max_equalizers = 1; | |
450 | module_param(max_equalizers, int, 0); | |
451 | MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers"); | |
452 | ||
453 | static int __init teql_init(void) | |
454 | { | |
455 | int i; | |
456 | int err = -ENODEV; | |
457 | ||
458 | for (i = 0; i < max_equalizers; i++) { | |
459 | struct net_device *dev; | |
460 | struct teql_master *master; | |
461 | ||
462 | dev = alloc_netdev(sizeof(struct teql_master), | |
463 | "teql%d", teql_master_setup); | |
464 | if (!dev) { | |
465 | err = -ENOMEM; | |
466 | break; | |
467 | } | |
468 | ||
469 | if ((err = register_netdev(dev))) { | |
470 | free_netdev(dev); | |
471 | break; | |
472 | } | |
473 | ||
2941a486 | 474 | master = netdev_priv(dev); |
1da177e4 LT |
475 | |
476 | strlcpy(master->qops.id, dev->name, IFNAMSIZ); | |
477 | err = register_qdisc(&master->qops); | |
478 | ||
479 | if (err) { | |
480 | unregister_netdev(dev); | |
481 | free_netdev(dev); | |
482 | break; | |
483 | } | |
484 | ||
485 | list_add_tail(&master->master_list, &master_dev_list); | |
486 | } | |
487 | return i ? 0 : err; | |
488 | } | |
489 | ||
10297b99 | 490 | static void __exit teql_exit(void) |
1da177e4 LT |
491 | { |
492 | struct teql_master *master, *nxt; | |
493 | ||
494 | list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) { | |
495 | ||
496 | list_del(&master->master_list); | |
497 | ||
498 | unregister_qdisc(&master->qops); | |
499 | unregister_netdev(master->dev); | |
500 | free_netdev(master->dev); | |
501 | } | |
502 | } | |
503 | ||
504 | module_init(teql_init); | |
505 | module_exit(teql_exit); | |
506 | ||
507 | MODULE_LICENSE("GPL"); |