Root/
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 <linux/types.h> |
13 | #include <linux/kernel.h> |
14 | #include <linux/string.h> |
15 | #include <linux/errno.h> |
16 | #include <linux/if_arp.h> |
17 | #include <linux/netdevice.h> |
18 | #include <linux/init.h> |
19 | #include <linux/skbuff.h> |
20 | #include <linux/moduleparam.h> |
21 | #include <net/dst.h> |
22 | #include <net/neighbour.h> |
23 | #include <net/pkt_sched.h> |
24 | |
25 | /* |
26 | How to setup it. |
27 | ---------------- |
28 | |
29 | After loading this module you will find a new device teqlN |
30 | and new qdisc with the same name. To join a slave to the equalizer |
31 | you should just set this qdisc on a device f.e. |
32 | |
33 | # tc qdisc add dev eth0 root teql0 |
34 | # tc qdisc add dev eth1 root teql0 |
35 | |
36 | That's all. Full PnP 8) |
37 | |
38 | Applicability. |
39 | -------------- |
40 | |
41 | 1. Slave devices MUST be active devices, i.e., they must raise the tbusy |
42 | signal and generate EOI events. If you want to equalize virtual devices |
43 | like tunnels, use a normal eql device. |
44 | 2. This device puts no limitations on physical slave characteristics |
45 | f.e. it will equalize 9600baud line and 100Mb ethernet perfectly :-) |
46 | Certainly, large difference in link speeds will make the resulting |
47 | eqalized link unusable, because of huge packet reordering. |
48 | I estimate an upper useful difference as ~10 times. |
49 | 3. If the slave requires address resolution, only protocols using |
50 | neighbour cache (IPv4/IPv6) will work over the equalized link. |
51 | Other protocols are still allowed to use the slave device directly, |
52 | which will not break load balancing, though native slave |
53 | traffic will have the highest priority. */ |
54 | |
55 | struct teql_master |
56 | { |
57 | struct Qdisc_ops qops; |
58 | struct net_device *dev; |
59 | struct Qdisc *slaves; |
60 | struct list_head master_list; |
61 | }; |
62 | |
63 | struct teql_sched_data |
64 | { |
65 | struct Qdisc *next; |
66 | struct teql_master *m; |
67 | struct neighbour *ncache; |
68 | struct sk_buff_head q; |
69 | }; |
70 | |
71 | #define NEXT_SLAVE(q) (((struct teql_sched_data*)qdisc_priv(q))->next) |
72 | |
73 | #define FMASK (IFF_BROADCAST|IFF_POINTOPOINT) |
74 | |
75 | /* "teql*" qdisc routines */ |
76 | |
77 | static int |
78 | teql_enqueue(struct sk_buff *skb, struct Qdisc* sch) |
79 | { |
80 | struct net_device *dev = qdisc_dev(sch); |
81 | struct teql_sched_data *q = qdisc_priv(sch); |
82 | |
83 | if (q->q.qlen < dev->tx_queue_len) { |
84 | __skb_queue_tail(&q->q, skb); |
85 | sch->bstats.bytes += qdisc_pkt_len(skb); |
86 | sch->bstats.packets++; |
87 | return 0; |
88 | } |
89 | |
90 | kfree_skb(skb); |
91 | sch->qstats.drops++; |
92 | return NET_XMIT_DROP; |
93 | } |
94 | |
95 | static struct sk_buff * |
96 | teql_dequeue(struct Qdisc* sch) |
97 | { |
98 | struct teql_sched_data *dat = qdisc_priv(sch); |
99 | struct netdev_queue *dat_queue; |
100 | struct sk_buff *skb; |
101 | |
102 | skb = __skb_dequeue(&dat->q); |
103 | dat_queue = netdev_get_tx_queue(dat->m->dev, 0); |
104 | if (skb == NULL) { |
105 | struct net_device *m = qdisc_dev(dat_queue->qdisc); |
106 | if (m) { |
107 | dat->m->slaves = sch; |
108 | netif_wake_queue(m); |
109 | } |
110 | } |
111 | sch->q.qlen = dat->q.qlen + dat_queue->qdisc->q.qlen; |
112 | return skb; |
113 | } |
114 | |
115 | static struct sk_buff * |
116 | teql_peek(struct Qdisc* sch) |
117 | { |
118 | /* teql is meant to be used as root qdisc */ |
119 | return NULL; |
120 | } |
121 | |
122 | static __inline__ void |
123 | teql_neigh_release(struct neighbour *n) |
124 | { |
125 | if (n) |
126 | neigh_release(n); |
127 | } |
128 | |
129 | static void |
130 | teql_reset(struct Qdisc* sch) |
131 | { |
132 | struct teql_sched_data *dat = qdisc_priv(sch); |
133 | |
134 | skb_queue_purge(&dat->q); |
135 | sch->q.qlen = 0; |
136 | teql_neigh_release(xchg(&dat->ncache, NULL)); |
137 | } |
138 | |
139 | static void |
140 | teql_destroy(struct Qdisc* sch) |
141 | { |
142 | struct Qdisc *q, *prev; |
143 | struct teql_sched_data *dat = qdisc_priv(sch); |
144 | struct teql_master *master = dat->m; |
145 | |
146 | if ((prev = master->slaves) != NULL) { |
147 | do { |
148 | q = NEXT_SLAVE(prev); |
149 | if (q == sch) { |
150 | NEXT_SLAVE(prev) = NEXT_SLAVE(q); |
151 | if (q == master->slaves) { |
152 | master->slaves = NEXT_SLAVE(q); |
153 | if (q == master->slaves) { |
154 | struct netdev_queue *txq; |
155 | spinlock_t *root_lock; |
156 | |
157 | txq = netdev_get_tx_queue(master->dev, 0); |
158 | master->slaves = NULL; |
159 | |
160 | root_lock = qdisc_root_sleeping_lock(txq->qdisc); |
161 | spin_lock_bh(root_lock); |
162 | qdisc_reset(txq->qdisc); |
163 | spin_unlock_bh(root_lock); |
164 | } |
165 | } |
166 | skb_queue_purge(&dat->q); |
167 | teql_neigh_release(xchg(&dat->ncache, NULL)); |
168 | break; |
169 | } |
170 | |
171 | } while ((prev = q) != master->slaves); |
172 | } |
173 | } |
174 | |
175 | static int teql_qdisc_init(struct Qdisc *sch, struct nlattr *opt) |
176 | { |
177 | struct net_device *dev = qdisc_dev(sch); |
178 | struct teql_master *m = (struct teql_master*)sch->ops; |
179 | struct teql_sched_data *q = qdisc_priv(sch); |
180 | |
181 | if (dev->hard_header_len > m->dev->hard_header_len) |
182 | return -EINVAL; |
183 | |
184 | if (m->dev == dev) |
185 | return -ELOOP; |
186 | |
187 | q->m = m; |
188 | |
189 | skb_queue_head_init(&q->q); |
190 | |
191 | if (m->slaves) { |
192 | if (m->dev->flags & IFF_UP) { |
193 | if ((m->dev->flags&IFF_POINTOPOINT && !(dev->flags&IFF_POINTOPOINT)) |
194 | || (m->dev->flags&IFF_BROADCAST && !(dev->flags&IFF_BROADCAST)) |
195 | || (m->dev->flags&IFF_MULTICAST && !(dev->flags&IFF_MULTICAST)) |
196 | || dev->mtu < m->dev->mtu) |
197 | return -EINVAL; |
198 | } else { |
199 | if (!(dev->flags&IFF_POINTOPOINT)) |
200 | m->dev->flags &= ~IFF_POINTOPOINT; |
201 | if (!(dev->flags&IFF_BROADCAST)) |
202 | m->dev->flags &= ~IFF_BROADCAST; |
203 | if (!(dev->flags&IFF_MULTICAST)) |
204 | m->dev->flags &= ~IFF_MULTICAST; |
205 | if (dev->mtu < m->dev->mtu) |
206 | m->dev->mtu = dev->mtu; |
207 | } |
208 | q->next = NEXT_SLAVE(m->slaves); |
209 | NEXT_SLAVE(m->slaves) = sch; |
210 | } else { |
211 | q->next = sch; |
212 | m->slaves = sch; |
213 | m->dev->mtu = dev->mtu; |
214 | m->dev->flags = (m->dev->flags&~FMASK)|(dev->flags&FMASK); |
215 | } |
216 | return 0; |
217 | } |
218 | |
219 | |
220 | static int |
221 | __teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res, struct net_device *dev) |
222 | { |
223 | struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0); |
224 | struct teql_sched_data *q = qdisc_priv(dev_queue->qdisc); |
225 | struct neighbour *mn = skb_dst(skb)->neighbour; |
226 | struct neighbour *n = q->ncache; |
227 | |
228 | if (mn->tbl == NULL) |
229 | return -EINVAL; |
230 | if (n && n->tbl == mn->tbl && |
231 | memcmp(n->primary_key, mn->primary_key, mn->tbl->key_len) == 0) { |
232 | atomic_inc(&n->refcnt); |
233 | } else { |
234 | n = __neigh_lookup_errno(mn->tbl, mn->primary_key, dev); |
235 | if (IS_ERR(n)) |
236 | return PTR_ERR(n); |
237 | } |
238 | if (neigh_event_send(n, skb_res) == 0) { |
239 | int err; |
240 | |
241 | read_lock(&n->lock); |
242 | err = dev_hard_header(skb, dev, ntohs(skb->protocol), |
243 | n->ha, NULL, skb->len); |
244 | read_unlock(&n->lock); |
245 | |
246 | if (err < 0) { |
247 | neigh_release(n); |
248 | return -EINVAL; |
249 | } |
250 | teql_neigh_release(xchg(&q->ncache, n)); |
251 | return 0; |
252 | } |
253 | neigh_release(n); |
254 | return (skb_res == NULL) ? -EAGAIN : 1; |
255 | } |
256 | |
257 | static inline int teql_resolve(struct sk_buff *skb, |
258 | struct sk_buff *skb_res, struct net_device *dev) |
259 | { |
260 | struct netdev_queue *txq = netdev_get_tx_queue(dev, 0); |
261 | if (txq->qdisc == &noop_qdisc) |
262 | return -ENODEV; |
263 | |
264 | if (dev->header_ops == NULL || |
265 | skb_dst(skb) == NULL || |
266 | skb_dst(skb)->neighbour == NULL) |
267 | return 0; |
268 | return __teql_resolve(skb, skb_res, dev); |
269 | } |
270 | |
271 | static netdev_tx_t teql_master_xmit(struct sk_buff *skb, struct net_device *dev) |
272 | { |
273 | struct teql_master *master = netdev_priv(dev); |
274 | struct netdev_queue *txq = netdev_get_tx_queue(dev, 0); |
275 | struct Qdisc *start, *q; |
276 | int busy; |
277 | int nores; |
278 | int subq = skb_get_queue_mapping(skb); |
279 | struct sk_buff *skb_res = NULL; |
280 | |
281 | start = master->slaves; |
282 | |
283 | restart: |
284 | nores = 0; |
285 | busy = 0; |
286 | |
287 | if ((q = start) == NULL) |
288 | goto drop; |
289 | |
290 | do { |
291 | struct net_device *slave = qdisc_dev(q); |
292 | struct netdev_queue *slave_txq = netdev_get_tx_queue(slave, 0); |
293 | const struct net_device_ops *slave_ops = slave->netdev_ops; |
294 | |
295 | if (slave_txq->qdisc_sleeping != q) |
296 | continue; |
297 | if (__netif_subqueue_stopped(slave, subq) || |
298 | !netif_running(slave)) { |
299 | busy = 1; |
300 | continue; |
301 | } |
302 | |
303 | switch (teql_resolve(skb, skb_res, slave)) { |
304 | case 0: |
305 | if (__netif_tx_trylock(slave_txq)) { |
306 | unsigned int length = qdisc_pkt_len(skb); |
307 | |
308 | if (!netif_tx_queue_stopped(slave_txq) && |
309 | !netif_tx_queue_frozen(slave_txq) && |
310 | slave_ops->ndo_start_xmit(skb, slave) == NETDEV_TX_OK) { |
311 | txq_trans_update(slave_txq); |
312 | __netif_tx_unlock(slave_txq); |
313 | master->slaves = NEXT_SLAVE(q); |
314 | netif_wake_queue(dev); |
315 | txq->tx_packets++; |
316 | txq->tx_bytes += length; |
317 | return NETDEV_TX_OK; |
318 | } |
319 | __netif_tx_unlock(slave_txq); |
320 | } |
321 | if (netif_queue_stopped(dev)) |
322 | busy = 1; |
323 | break; |
324 | case 1: |
325 | master->slaves = NEXT_SLAVE(q); |
326 | return NETDEV_TX_OK; |
327 | default: |
328 | nores = 1; |
329 | break; |
330 | } |
331 | __skb_pull(skb, skb_network_offset(skb)); |
332 | } while ((q = NEXT_SLAVE(q)) != start); |
333 | |
334 | if (nores && skb_res == NULL) { |
335 | skb_res = skb; |
336 | goto restart; |
337 | } |
338 | |
339 | if (busy) { |
340 | netif_stop_queue(dev); |
341 | return NETDEV_TX_BUSY; |
342 | } |
343 | dev->stats.tx_errors++; |
344 | |
345 | drop: |
346 | txq->tx_dropped++; |
347 | dev_kfree_skb(skb); |
348 | return NETDEV_TX_OK; |
349 | } |
350 | |
351 | static int teql_master_open(struct net_device *dev) |
352 | { |
353 | struct Qdisc * q; |
354 | struct teql_master *m = netdev_priv(dev); |
355 | int mtu = 0xFFFE; |
356 | unsigned flags = IFF_NOARP|IFF_MULTICAST; |
357 | |
358 | if (m->slaves == NULL) |
359 | return -EUNATCH; |
360 | |
361 | flags = FMASK; |
362 | |
363 | q = m->slaves; |
364 | do { |
365 | struct net_device *slave = qdisc_dev(q); |
366 | |
367 | if (slave == NULL) |
368 | return -EUNATCH; |
369 | |
370 | if (slave->mtu < mtu) |
371 | mtu = slave->mtu; |
372 | if (slave->hard_header_len > LL_MAX_HEADER) |
373 | return -EINVAL; |
374 | |
375 | /* If all the slaves are BROADCAST, master is BROADCAST |
376 | If all the slaves are PtP, master is PtP |
377 | Otherwise, master is NBMA. |
378 | */ |
379 | if (!(slave->flags&IFF_POINTOPOINT)) |
380 | flags &= ~IFF_POINTOPOINT; |
381 | if (!(slave->flags&IFF_BROADCAST)) |
382 | flags &= ~IFF_BROADCAST; |
383 | if (!(slave->flags&IFF_MULTICAST)) |
384 | flags &= ~IFF_MULTICAST; |
385 | } while ((q = NEXT_SLAVE(q)) != m->slaves); |
386 | |
387 | m->dev->mtu = mtu; |
388 | m->dev->flags = (m->dev->flags&~FMASK) | flags; |
389 | netif_start_queue(m->dev); |
390 | return 0; |
391 | } |
392 | |
393 | static int teql_master_close(struct net_device *dev) |
394 | { |
395 | netif_stop_queue(dev); |
396 | return 0; |
397 | } |
398 | |
399 | static int teql_master_mtu(struct net_device *dev, int new_mtu) |
400 | { |
401 | struct teql_master *m = netdev_priv(dev); |
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 > qdisc_dev(q)->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 const struct net_device_ops teql_netdev_ops = { |
420 | .ndo_open = teql_master_open, |
421 | .ndo_stop = teql_master_close, |
422 | .ndo_start_xmit = teql_master_xmit, |
423 | .ndo_change_mtu = teql_master_mtu, |
424 | }; |
425 | |
426 | static __init void teql_master_setup(struct net_device *dev) |
427 | { |
428 | struct teql_master *master = netdev_priv(dev); |
429 | struct Qdisc_ops *ops = &master->qops; |
430 | |
431 | master->dev = dev; |
432 | ops->priv_size = sizeof(struct teql_sched_data); |
433 | |
434 | ops->enqueue = teql_enqueue; |
435 | ops->dequeue = teql_dequeue; |
436 | ops->peek = teql_peek; |
437 | ops->init = teql_qdisc_init; |
438 | ops->reset = teql_reset; |
439 | ops->destroy = teql_destroy; |
440 | ops->owner = THIS_MODULE; |
441 | |
442 | dev->netdev_ops = &teql_netdev_ops; |
443 | dev->type = ARPHRD_VOID; |
444 | dev->mtu = 1500; |
445 | dev->tx_queue_len = 100; |
446 | dev->flags = IFF_NOARP; |
447 | dev->hard_header_len = LL_MAX_HEADER; |
448 | } |
449 | |
450 | static LIST_HEAD(master_dev_list); |
451 | static int max_equalizers = 1; |
452 | module_param(max_equalizers, int, 0); |
453 | MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers"); |
454 | |
455 | static int __init teql_init(void) |
456 | { |
457 | int i; |
458 | int err = -ENODEV; |
459 | |
460 | for (i = 0; i < max_equalizers; i++) { |
461 | struct net_device *dev; |
462 | struct teql_master *master; |
463 | |
464 | dev = alloc_netdev(sizeof(struct teql_master), |
465 | "teql%d", teql_master_setup); |
466 | if (!dev) { |
467 | err = -ENOMEM; |
468 | break; |
469 | } |
470 | |
471 | if ((err = register_netdev(dev))) { |
472 | free_netdev(dev); |
473 | break; |
474 | } |
475 | |
476 | master = netdev_priv(dev); |
477 | |
478 | strlcpy(master->qops.id, dev->name, IFNAMSIZ); |
479 | err = register_qdisc(&master->qops); |
480 | |
481 | if (err) { |
482 | unregister_netdev(dev); |
483 | free_netdev(dev); |
484 | break; |
485 | } |
486 | |
487 | list_add_tail(&master->master_list, &master_dev_list); |
488 | } |
489 | return i ? 0 : err; |
490 | } |
491 | |
492 | static void __exit teql_exit(void) |
493 | { |
494 | struct teql_master *master, *nxt; |
495 | |
496 | list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) { |
497 | |
498 | list_del(&master->master_list); |
499 | |
500 | unregister_qdisc(&master->qops); |
501 | unregister_netdev(master->dev); |
502 | free_netdev(master->dev); |
503 | } |
504 | } |
505 | |
506 | module_init(teql_init); |
507 | module_exit(teql_exit); |
508 | |
509 | MODULE_LICENSE("GPL"); |
510 |
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-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9