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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* net/sched/sch_teql.c "True" (or "trivial") link equalizer.
3 *
4 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
5 */
6
7#include <linux/module.h>
8#include <linux/types.h>
9#include <linux/kernel.h>
10#include <linux/slab.h>
11#include <linux/string.h>
12#include <linux/errno.h>
13#include <linux/if_arp.h>
14#include <linux/netdevice.h>
15#include <linux/init.h>
16#include <linux/skbuff.h>
17#include <linux/moduleparam.h>
18#include <net/dst.h>
19#include <net/neighbour.h>
20#include <net/pkt_sched.h>
21
22/*
23 How to setup it.
24 ----------------
25
26 After loading this module you will find a new device teqlN
27 and new qdisc with the same name. To join a slave to the equalizer
28 you should just set this qdisc on a device f.e.
29
30 # tc qdisc add dev eth0 root teql0
31 # tc qdisc add dev eth1 root teql0
32
33 That's all. Full PnP 8)
34
35 Applicability.
36 --------------
37
38 1. Slave devices MUST be active devices, i.e., they must raise the tbusy
39 signal and generate EOI events. If you want to equalize virtual devices
40 like tunnels, use a normal eql device.
41 2. This device puts no limitations on physical slave characteristics
42 f.e. it will equalize 9600baud line and 100Mb ethernet perfectly :-)
43 Certainly, large difference in link speeds will make the resulting
44 eqalized link unusable, because of huge packet reordering.
45 I estimate an upper useful difference as ~10 times.
46 3. If the slave requires address resolution, only protocols using
47 neighbour cache (IPv4/IPv6) will work over the equalized link.
48 Other protocols are still allowed to use the slave device directly,
49 which will not break load balancing, though native slave
50 traffic will have the highest priority. */
51
52struct teql_master {
53 struct Qdisc_ops qops;
54 struct net_device *dev;
55 struct Qdisc *slaves;
56 struct list_head master_list;
57 unsigned long tx_bytes;
58 unsigned long tx_packets;
59 unsigned long tx_errors;
60 unsigned long tx_dropped;
61};
62
63struct teql_sched_data {
64 struct Qdisc *next;
65 struct teql_master *m;
66 struct sk_buff_head q;
67};
68
69#define NEXT_SLAVE(q) (((struct teql_sched_data *)qdisc_priv(q))->next)
70
71#define FMASK (IFF_BROADCAST | IFF_POINTOPOINT)
72
73/* "teql*" qdisc routines */
74
75static int
76teql_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
77{
78 struct net_device *dev = qdisc_dev(sch);
79 struct teql_sched_data *q = qdisc_priv(sch);
80
81 if (q->q.qlen < dev->tx_queue_len) {
82 __skb_queue_tail(&q->q, skb);
83 return NET_XMIT_SUCCESS;
84 }
85
86 return qdisc_drop(skb, sch, to_free);
87}
88
89static struct sk_buff *
90teql_dequeue(struct Qdisc *sch)
91{
92 struct teql_sched_data *dat = qdisc_priv(sch);
93 struct netdev_queue *dat_queue;
94 struct sk_buff *skb;
95 struct Qdisc *q;
96
97 skb = __skb_dequeue(&dat->q);
98 dat_queue = netdev_get_tx_queue(dat->m->dev, 0);
99 q = rcu_dereference_bh(dat_queue->qdisc);
100
101 if (skb == NULL) {
102 struct net_device *m = qdisc_dev(q);
103 if (m) {
104 dat->m->slaves = sch;
105 netif_wake_queue(m);
106 }
107 } else {
108 qdisc_bstats_update(sch, skb);
109 }
110 sch->q.qlen = dat->q.qlen + q->q.qlen;
111 return skb;
112}
113
114static struct sk_buff *
115teql_peek(struct Qdisc *sch)
116{
117 /* teql is meant to be used as root qdisc */
118 return NULL;
119}
120
121static void
122teql_reset(struct Qdisc *sch)
123{
124 struct teql_sched_data *dat = qdisc_priv(sch);
125
126 skb_queue_purge(&dat->q);
127}
128
129static void
130teql_destroy(struct Qdisc *sch)
131{
132 struct Qdisc *q, *prev;
133 struct teql_sched_data *dat = qdisc_priv(sch);
134 struct teql_master *master = dat->m;
135
136 if (!master)
137 return;
138
139 prev = master->slaves;
140 if (prev) {
141 do {
142 q = NEXT_SLAVE(prev);
143 if (q == sch) {
144 NEXT_SLAVE(prev) = NEXT_SLAVE(q);
145 if (q == master->slaves) {
146 master->slaves = NEXT_SLAVE(q);
147 if (q == master->slaves) {
148 struct netdev_queue *txq;
149 spinlock_t *root_lock;
150
151 txq = netdev_get_tx_queue(master->dev, 0);
152 master->slaves = NULL;
153
154 root_lock = qdisc_root_sleeping_lock(rtnl_dereference(txq->qdisc));
155 spin_lock_bh(root_lock);
156 qdisc_reset(rtnl_dereference(txq->qdisc));
157 spin_unlock_bh(root_lock);
158 }
159 }
160 skb_queue_purge(&dat->q);
161 break;
162 }
163
164 } while ((prev = q) != master->slaves);
165 }
166}
167
168static int teql_qdisc_init(struct Qdisc *sch, struct nlattr *opt,
169 struct netlink_ext_ack *extack)
170{
171 struct net_device *dev = qdisc_dev(sch);
172 struct teql_master *m = (struct teql_master *)sch->ops;
173 struct teql_sched_data *q = qdisc_priv(sch);
174
175 if (dev->hard_header_len > m->dev->hard_header_len)
176 return -EINVAL;
177
178 if (m->dev == dev)
179 return -ELOOP;
180
181 q->m = m;
182
183 skb_queue_head_init(&q->q);
184
185 if (m->slaves) {
186 if (m->dev->flags & IFF_UP) {
187 if ((m->dev->flags & IFF_POINTOPOINT &&
188 !(dev->flags & IFF_POINTOPOINT)) ||
189 (m->dev->flags & IFF_BROADCAST &&
190 !(dev->flags & IFF_BROADCAST)) ||
191 (m->dev->flags & IFF_MULTICAST &&
192 !(dev->flags & IFF_MULTICAST)) ||
193 dev->mtu < m->dev->mtu)
194 return -EINVAL;
195 } else {
196 if (!(dev->flags&IFF_POINTOPOINT))
197 m->dev->flags &= ~IFF_POINTOPOINT;
198 if (!(dev->flags&IFF_BROADCAST))
199 m->dev->flags &= ~IFF_BROADCAST;
200 if (!(dev->flags&IFF_MULTICAST))
201 m->dev->flags &= ~IFF_MULTICAST;
202 if (dev->mtu < m->dev->mtu)
203 m->dev->mtu = dev->mtu;
204 }
205 q->next = NEXT_SLAVE(m->slaves);
206 NEXT_SLAVE(m->slaves) = sch;
207 } else {
208 q->next = sch;
209 m->slaves = sch;
210 m->dev->mtu = dev->mtu;
211 m->dev->flags = (m->dev->flags&~FMASK)|(dev->flags&FMASK);
212 }
213 return 0;
214}
215
216
217static int
218__teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res,
219 struct net_device *dev, struct netdev_queue *txq,
220 struct dst_entry *dst)
221{
222 struct neighbour *n;
223 int err = 0;
224
225 n = dst_neigh_lookup_skb(dst, skb);
226 if (!n)
227 return -ENOENT;
228
229 if (dst->dev != dev) {
230 struct neighbour *mn;
231
232 mn = __neigh_lookup_errno(n->tbl, n->primary_key, dev);
233 neigh_release(n);
234 if (IS_ERR(mn))
235 return PTR_ERR(mn);
236 n = mn;
237 }
238
239 if (neigh_event_send(n, skb_res) == 0) {
240 int err;
241 char haddr[MAX_ADDR_LEN];
242
243 neigh_ha_snapshot(haddr, n, dev);
244 err = dev_hard_header(skb, dev, ntohs(skb_protocol(skb, false)),
245 haddr, NULL, skb->len);
246
247 if (err < 0)
248 err = -EINVAL;
249 } else {
250 err = (skb_res == NULL) ? -EAGAIN : 1;
251 }
252 neigh_release(n);
253 return err;
254}
255
256static inline int teql_resolve(struct sk_buff *skb,
257 struct sk_buff *skb_res,
258 struct net_device *dev,
259 struct netdev_queue *txq)
260{
261 struct dst_entry *dst = skb_dst(skb);
262 int res;
263
264 if (rcu_access_pointer(txq->qdisc) == &noop_qdisc)
265 return -ENODEV;
266
267 if (!dev->header_ops || !dst)
268 return 0;
269
270 rcu_read_lock();
271 res = __teql_resolve(skb, skb_res, dev, txq, dst);
272 rcu_read_unlock();
273
274 return res;
275}
276
277static netdev_tx_t teql_master_xmit(struct sk_buff *skb, struct net_device *dev)
278{
279 struct teql_master *master = netdev_priv(dev);
280 struct Qdisc *start, *q;
281 int busy;
282 int nores;
283 int subq = skb_get_queue_mapping(skb);
284 struct sk_buff *skb_res = NULL;
285
286 start = master->slaves;
287
288restart:
289 nores = 0;
290 busy = 0;
291
292 q = start;
293 if (!q)
294 goto drop;
295
296 do {
297 struct net_device *slave = qdisc_dev(q);
298 struct netdev_queue *slave_txq = netdev_get_tx_queue(slave, 0);
299
300 if (slave_txq->qdisc_sleeping != q)
301 continue;
302 if (netif_xmit_stopped(netdev_get_tx_queue(slave, subq)) ||
303 !netif_running(slave)) {
304 busy = 1;
305 continue;
306 }
307
308 switch (teql_resolve(skb, skb_res, slave, slave_txq)) {
309 case 0:
310 if (__netif_tx_trylock(slave_txq)) {
311 unsigned int length = qdisc_pkt_len(skb);
312
313 if (!netif_xmit_frozen_or_stopped(slave_txq) &&
314 netdev_start_xmit(skb, slave, slave_txq, false) ==
315 NETDEV_TX_OK) {
316 __netif_tx_unlock(slave_txq);
317 master->slaves = NEXT_SLAVE(q);
318 netif_wake_queue(dev);
319 master->tx_packets++;
320 master->tx_bytes += length;
321 return NETDEV_TX_OK;
322 }
323 __netif_tx_unlock(slave_txq);
324 }
325 if (netif_xmit_stopped(netdev_get_tx_queue(dev, 0)))
326 busy = 1;
327 break;
328 case 1:
329 master->slaves = NEXT_SLAVE(q);
330 return NETDEV_TX_OK;
331 default:
332 nores = 1;
333 break;
334 }
335 __skb_pull(skb, skb_network_offset(skb));
336 } while ((q = NEXT_SLAVE(q)) != start);
337
338 if (nores && skb_res == NULL) {
339 skb_res = skb;
340 goto restart;
341 }
342
343 if (busy) {
344 netif_stop_queue(dev);
345 return NETDEV_TX_BUSY;
346 }
347 master->tx_errors++;
348
349drop:
350 master->tx_dropped++;
351 dev_kfree_skb(skb);
352 return NETDEV_TX_OK;
353}
354
355static int teql_master_open(struct net_device *dev)
356{
357 struct Qdisc *q;
358 struct teql_master *m = netdev_priv(dev);
359 int mtu = 0xFFFE;
360 unsigned int flags = IFF_NOARP | IFF_MULTICAST;
361
362 if (m->slaves == NULL)
363 return -EUNATCH;
364
365 flags = FMASK;
366
367 q = m->slaves;
368 do {
369 struct net_device *slave = qdisc_dev(q);
370
371 if (slave == NULL)
372 return -EUNATCH;
373
374 if (slave->mtu < mtu)
375 mtu = slave->mtu;
376 if (slave->hard_header_len > LL_MAX_HEADER)
377 return -EINVAL;
378
379 /* If all the slaves are BROADCAST, master is BROADCAST
380 If all the slaves are PtP, master is PtP
381 Otherwise, master is NBMA.
382 */
383 if (!(slave->flags&IFF_POINTOPOINT))
384 flags &= ~IFF_POINTOPOINT;
385 if (!(slave->flags&IFF_BROADCAST))
386 flags &= ~IFF_BROADCAST;
387 if (!(slave->flags&IFF_MULTICAST))
388 flags &= ~IFF_MULTICAST;
389 } while ((q = NEXT_SLAVE(q)) != m->slaves);
390
391 m->dev->mtu = mtu;
392 m->dev->flags = (m->dev->flags&~FMASK) | flags;
393 netif_start_queue(m->dev);
394 return 0;
395}
396
397static int teql_master_close(struct net_device *dev)
398{
399 netif_stop_queue(dev);
400 return 0;
401}
402
403static void teql_master_stats64(struct net_device *dev,
404 struct rtnl_link_stats64 *stats)
405{
406 struct teql_master *m = netdev_priv(dev);
407
408 stats->tx_packets = m->tx_packets;
409 stats->tx_bytes = m->tx_bytes;
410 stats->tx_errors = m->tx_errors;
411 stats->tx_dropped = m->tx_dropped;
412}
413
414static int teql_master_mtu(struct net_device *dev, int new_mtu)
415{
416 struct teql_master *m = netdev_priv(dev);
417 struct Qdisc *q;
418
419 q = m->slaves;
420 if (q) {
421 do {
422 if (new_mtu > qdisc_dev(q)->mtu)
423 return -EINVAL;
424 } while ((q = NEXT_SLAVE(q)) != m->slaves);
425 }
426
427 dev->mtu = new_mtu;
428 return 0;
429}
430
431static const struct net_device_ops teql_netdev_ops = {
432 .ndo_open = teql_master_open,
433 .ndo_stop = teql_master_close,
434 .ndo_start_xmit = teql_master_xmit,
435 .ndo_get_stats64 = teql_master_stats64,
436 .ndo_change_mtu = teql_master_mtu,
437};
438
439static __init void teql_master_setup(struct net_device *dev)
440{
441 struct teql_master *master = netdev_priv(dev);
442 struct Qdisc_ops *ops = &master->qops;
443
444 master->dev = dev;
445 ops->priv_size = sizeof(struct teql_sched_data);
446
447 ops->enqueue = teql_enqueue;
448 ops->dequeue = teql_dequeue;
449 ops->peek = teql_peek;
450 ops->init = teql_qdisc_init;
451 ops->reset = teql_reset;
452 ops->destroy = teql_destroy;
453 ops->owner = THIS_MODULE;
454
455 dev->netdev_ops = &teql_netdev_ops;
456 dev->type = ARPHRD_VOID;
457 dev->mtu = 1500;
458 dev->min_mtu = 68;
459 dev->max_mtu = 65535;
460 dev->tx_queue_len = 100;
461 dev->flags = IFF_NOARP;
462 dev->hard_header_len = LL_MAX_HEADER;
463 netif_keep_dst(dev);
464}
465
466static LIST_HEAD(master_dev_list);
467static int max_equalizers = 1;
468module_param(max_equalizers, int, 0);
469MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers");
470
471static int __init teql_init(void)
472{
473 int i;
474 int err = -ENODEV;
475
476 for (i = 0; i < max_equalizers; i++) {
477 struct net_device *dev;
478 struct teql_master *master;
479
480 dev = alloc_netdev(sizeof(struct teql_master), "teql%d",
481 NET_NAME_UNKNOWN, teql_master_setup);
482 if (!dev) {
483 err = -ENOMEM;
484 break;
485 }
486
487 if ((err = register_netdev(dev))) {
488 free_netdev(dev);
489 break;
490 }
491
492 master = netdev_priv(dev);
493
494 strscpy(master->qops.id, dev->name, IFNAMSIZ);
495 err = register_qdisc(&master->qops);
496
497 if (err) {
498 unregister_netdev(dev);
499 free_netdev(dev);
500 break;
501 }
502
503 list_add_tail(&master->master_list, &master_dev_list);
504 }
505 return i ? 0 : err;
506}
507
508static void __exit teql_exit(void)
509{
510 struct teql_master *master, *nxt;
511
512 list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) {
513
514 list_del(&master->master_list);
515
516 unregister_qdisc(&master->qops);
517 unregister_netdev(master->dev);
518 free_netdev(master->dev);
519 }
520}
521
522module_init(teql_init);
523module_exit(teql_exit);
524
525MODULE_LICENSE("GPL");
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/slab.h>
15#include <linux/string.h>
16#include <linux/errno.h>
17#include <linux/if_arp.h>
18#include <linux/netdevice.h>
19#include <linux/init.h>
20#include <linux/skbuff.h>
21#include <linux/moduleparam.h>
22#include <net/dst.h>
23#include <net/neighbour.h>
24#include <net/pkt_sched.h>
25
26/*
27 How to setup it.
28 ----------------
29
30 After loading this module you will find a new device teqlN
31 and new qdisc with the same name. To join a slave to the equalizer
32 you should just set this qdisc on a device f.e.
33
34 # tc qdisc add dev eth0 root teql0
35 # tc qdisc add dev eth1 root teql0
36
37 That's all. Full PnP 8)
38
39 Applicability.
40 --------------
41
42 1. Slave devices MUST be active devices, i.e., they must raise the tbusy
43 signal and generate EOI events. If you want to equalize virtual devices
44 like tunnels, use a normal eql device.
45 2. This device puts no limitations on physical slave characteristics
46 f.e. it will equalize 9600baud line and 100Mb ethernet perfectly :-)
47 Certainly, large difference in link speeds will make the resulting
48 eqalized link unusable, because of huge packet reordering.
49 I estimate an upper useful difference as ~10 times.
50 3. If the slave requires address resolution, only protocols using
51 neighbour cache (IPv4/IPv6) will work over the equalized link.
52 Other protocols are still allowed to use the slave device directly,
53 which will not break load balancing, though native slave
54 traffic will have the highest priority. */
55
56struct teql_master {
57 struct Qdisc_ops qops;
58 struct net_device *dev;
59 struct Qdisc *slaves;
60 struct list_head master_list;
61 unsigned long tx_bytes;
62 unsigned long tx_packets;
63 unsigned long tx_errors;
64 unsigned long tx_dropped;
65};
66
67struct teql_sched_data {
68 struct Qdisc *next;
69 struct teql_master *m;
70 struct sk_buff_head q;
71};
72
73#define NEXT_SLAVE(q) (((struct teql_sched_data *)qdisc_priv(q))->next)
74
75#define FMASK (IFF_BROADCAST | IFF_POINTOPOINT)
76
77/* "teql*" qdisc routines */
78
79static int
80teql_enqueue(struct sk_buff *skb, struct Qdisc *sch)
81{
82 struct net_device *dev = qdisc_dev(sch);
83 struct teql_sched_data *q = qdisc_priv(sch);
84
85 if (q->q.qlen < dev->tx_queue_len) {
86 __skb_queue_tail(&q->q, skb);
87 return NET_XMIT_SUCCESS;
88 }
89
90 return qdisc_drop(skb, sch);
91}
92
93static struct sk_buff *
94teql_dequeue(struct Qdisc *sch)
95{
96 struct teql_sched_data *dat = qdisc_priv(sch);
97 struct netdev_queue *dat_queue;
98 struct sk_buff *skb;
99
100 skb = __skb_dequeue(&dat->q);
101 dat_queue = netdev_get_tx_queue(dat->m->dev, 0);
102 if (skb == NULL) {
103 struct net_device *m = qdisc_dev(dat_queue->qdisc);
104 if (m) {
105 dat->m->slaves = sch;
106 netif_wake_queue(m);
107 }
108 } else {
109 qdisc_bstats_update(sch, skb);
110 }
111 sch->q.qlen = dat->q.qlen + dat_queue->qdisc->q.qlen;
112 return skb;
113}
114
115static struct sk_buff *
116teql_peek(struct Qdisc *sch)
117{
118 /* teql is meant to be used as root qdisc */
119 return NULL;
120}
121
122static inline void
123teql_neigh_release(struct neighbour *n)
124{
125 if (n)
126 neigh_release(n);
127}
128
129static void
130teql_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}
137
138static void
139teql_destroy(struct Qdisc *sch)
140{
141 struct Qdisc *q, *prev;
142 struct teql_sched_data *dat = qdisc_priv(sch);
143 struct teql_master *master = dat->m;
144
145 prev = master->slaves;
146 if (prev) {
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 break;
168 }
169
170 } while ((prev = q) != master->slaves);
171 }
172}
173
174static int teql_qdisc_init(struct Qdisc *sch, struct nlattr *opt)
175{
176 struct net_device *dev = qdisc_dev(sch);
177 struct teql_master *m = (struct teql_master *)sch->ops;
178 struct teql_sched_data *q = qdisc_priv(sch);
179
180 if (dev->hard_header_len > m->dev->hard_header_len)
181 return -EINVAL;
182
183 if (m->dev == dev)
184 return -ELOOP;
185
186 q->m = m;
187
188 skb_queue_head_init(&q->q);
189
190 if (m->slaves) {
191 if (m->dev->flags & IFF_UP) {
192 if ((m->dev->flags & IFF_POINTOPOINT &&
193 !(dev->flags & IFF_POINTOPOINT)) ||
194 (m->dev->flags & IFF_BROADCAST &&
195 !(dev->flags & IFF_BROADCAST)) ||
196 (m->dev->flags & IFF_MULTICAST &&
197 !(dev->flags & IFF_MULTICAST)) ||
198 dev->mtu < m->dev->mtu)
199 return -EINVAL;
200 } else {
201 if (!(dev->flags&IFF_POINTOPOINT))
202 m->dev->flags &= ~IFF_POINTOPOINT;
203 if (!(dev->flags&IFF_BROADCAST))
204 m->dev->flags &= ~IFF_BROADCAST;
205 if (!(dev->flags&IFF_MULTICAST))
206 m->dev->flags &= ~IFF_MULTICAST;
207 if (dev->mtu < m->dev->mtu)
208 m->dev->mtu = dev->mtu;
209 }
210 q->next = NEXT_SLAVE(m->slaves);
211 NEXT_SLAVE(m->slaves) = sch;
212 } else {
213 q->next = sch;
214 m->slaves = sch;
215 m->dev->mtu = dev->mtu;
216 m->dev->flags = (m->dev->flags&~FMASK)|(dev->flags&FMASK);
217 }
218 return 0;
219}
220
221
222static int
223__teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res,
224 struct net_device *dev, struct netdev_queue *txq,
225 struct dst_entry *dst)
226{
227 struct neighbour *n;
228 int err = 0;
229
230 n = dst_neigh_lookup_skb(dst, skb);
231 if (!n)
232 return -ENOENT;
233
234 if (dst->dev != dev) {
235 struct neighbour *mn;
236
237 mn = __neigh_lookup_errno(n->tbl, n->primary_key, dev);
238 neigh_release(n);
239 if (IS_ERR(mn))
240 return PTR_ERR(mn);
241 n = mn;
242 }
243
244 if (neigh_event_send(n, skb_res) == 0) {
245 int err;
246 char haddr[MAX_ADDR_LEN];
247
248 neigh_ha_snapshot(haddr, n, dev);
249 err = dev_hard_header(skb, dev, ntohs(skb->protocol), haddr,
250 NULL, skb->len);
251
252 if (err < 0)
253 err = -EINVAL;
254 } else {
255 err = (skb_res == NULL) ? -EAGAIN : 1;
256 }
257 neigh_release(n);
258 return err;
259}
260
261static inline int teql_resolve(struct sk_buff *skb,
262 struct sk_buff *skb_res,
263 struct net_device *dev,
264 struct netdev_queue *txq)
265{
266 struct dst_entry *dst = skb_dst(skb);
267 int res;
268
269 if (txq->qdisc == &noop_qdisc)
270 return -ENODEV;
271
272 if (!dev->header_ops || !dst)
273 return 0;
274
275 rcu_read_lock();
276 res = __teql_resolve(skb, skb_res, dev, txq, dst);
277 rcu_read_unlock();
278
279 return res;
280}
281
282static netdev_tx_t teql_master_xmit(struct sk_buff *skb, struct net_device *dev)
283{
284 struct teql_master *master = netdev_priv(dev);
285 struct Qdisc *start, *q;
286 int busy;
287 int nores;
288 int subq = skb_get_queue_mapping(skb);
289 struct sk_buff *skb_res = NULL;
290
291 start = master->slaves;
292
293restart:
294 nores = 0;
295 busy = 0;
296
297 q = start;
298 if (!q)
299 goto drop;
300
301 do {
302 struct net_device *slave = qdisc_dev(q);
303 struct netdev_queue *slave_txq = netdev_get_tx_queue(slave, 0);
304 const struct net_device_ops *slave_ops = slave->netdev_ops;
305
306 if (slave_txq->qdisc_sleeping != q)
307 continue;
308 if (netif_xmit_stopped(netdev_get_tx_queue(slave, subq)) ||
309 !netif_running(slave)) {
310 busy = 1;
311 continue;
312 }
313
314 switch (teql_resolve(skb, skb_res, slave, slave_txq)) {
315 case 0:
316 if (__netif_tx_trylock(slave_txq)) {
317 unsigned int length = qdisc_pkt_len(skb);
318
319 if (!netif_xmit_frozen_or_stopped(slave_txq) &&
320 slave_ops->ndo_start_xmit(skb, slave) == NETDEV_TX_OK) {
321 txq_trans_update(slave_txq);
322 __netif_tx_unlock(slave_txq);
323 master->slaves = NEXT_SLAVE(q);
324 netif_wake_queue(dev);
325 master->tx_packets++;
326 master->tx_bytes += length;
327 return NETDEV_TX_OK;
328 }
329 __netif_tx_unlock(slave_txq);
330 }
331 if (netif_xmit_stopped(netdev_get_tx_queue(dev, 0)))
332 busy = 1;
333 break;
334 case 1:
335 master->slaves = NEXT_SLAVE(q);
336 return NETDEV_TX_OK;
337 default:
338 nores = 1;
339 break;
340 }
341 __skb_pull(skb, skb_network_offset(skb));
342 } while ((q = NEXT_SLAVE(q)) != start);
343
344 if (nores && skb_res == NULL) {
345 skb_res = skb;
346 goto restart;
347 }
348
349 if (busy) {
350 netif_stop_queue(dev);
351 return NETDEV_TX_BUSY;
352 }
353 master->tx_errors++;
354
355drop:
356 master->tx_dropped++;
357 dev_kfree_skb(skb);
358 return NETDEV_TX_OK;
359}
360
361static int teql_master_open(struct net_device *dev)
362{
363 struct Qdisc *q;
364 struct teql_master *m = netdev_priv(dev);
365 int mtu = 0xFFFE;
366 unsigned int flags = IFF_NOARP | IFF_MULTICAST;
367
368 if (m->slaves == NULL)
369 return -EUNATCH;
370
371 flags = FMASK;
372
373 q = m->slaves;
374 do {
375 struct net_device *slave = qdisc_dev(q);
376
377 if (slave == NULL)
378 return -EUNATCH;
379
380 if (slave->mtu < mtu)
381 mtu = slave->mtu;
382 if (slave->hard_header_len > LL_MAX_HEADER)
383 return -EINVAL;
384
385 /* If all the slaves are BROADCAST, master is BROADCAST
386 If all the slaves are PtP, master is PtP
387 Otherwise, master is NBMA.
388 */
389 if (!(slave->flags&IFF_POINTOPOINT))
390 flags &= ~IFF_POINTOPOINT;
391 if (!(slave->flags&IFF_BROADCAST))
392 flags &= ~IFF_BROADCAST;
393 if (!(slave->flags&IFF_MULTICAST))
394 flags &= ~IFF_MULTICAST;
395 } while ((q = NEXT_SLAVE(q)) != m->slaves);
396
397 m->dev->mtu = mtu;
398 m->dev->flags = (m->dev->flags&~FMASK) | flags;
399 netif_start_queue(m->dev);
400 return 0;
401}
402
403static int teql_master_close(struct net_device *dev)
404{
405 netif_stop_queue(dev);
406 return 0;
407}
408
409static struct rtnl_link_stats64 *teql_master_stats64(struct net_device *dev,
410 struct rtnl_link_stats64 *stats)
411{
412 struct teql_master *m = netdev_priv(dev);
413
414 stats->tx_packets = m->tx_packets;
415 stats->tx_bytes = m->tx_bytes;
416 stats->tx_errors = m->tx_errors;
417 stats->tx_dropped = m->tx_dropped;
418 return stats;
419}
420
421static int teql_master_mtu(struct net_device *dev, int new_mtu)
422{
423 struct teql_master *m = netdev_priv(dev);
424 struct Qdisc *q;
425
426 if (new_mtu < 68)
427 return -EINVAL;
428
429 q = m->slaves;
430 if (q) {
431 do {
432 if (new_mtu > qdisc_dev(q)->mtu)
433 return -EINVAL;
434 } while ((q = NEXT_SLAVE(q)) != m->slaves);
435 }
436
437 dev->mtu = new_mtu;
438 return 0;
439}
440
441static const struct net_device_ops teql_netdev_ops = {
442 .ndo_open = teql_master_open,
443 .ndo_stop = teql_master_close,
444 .ndo_start_xmit = teql_master_xmit,
445 .ndo_get_stats64 = teql_master_stats64,
446 .ndo_change_mtu = teql_master_mtu,
447};
448
449static __init void teql_master_setup(struct net_device *dev)
450{
451 struct teql_master *master = netdev_priv(dev);
452 struct Qdisc_ops *ops = &master->qops;
453
454 master->dev = dev;
455 ops->priv_size = sizeof(struct teql_sched_data);
456
457 ops->enqueue = teql_enqueue;
458 ops->dequeue = teql_dequeue;
459 ops->peek = teql_peek;
460 ops->init = teql_qdisc_init;
461 ops->reset = teql_reset;
462 ops->destroy = teql_destroy;
463 ops->owner = THIS_MODULE;
464
465 dev->netdev_ops = &teql_netdev_ops;
466 dev->type = ARPHRD_VOID;
467 dev->mtu = 1500;
468 dev->tx_queue_len = 100;
469 dev->flags = IFF_NOARP;
470 dev->hard_header_len = LL_MAX_HEADER;
471 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
472}
473
474static LIST_HEAD(master_dev_list);
475static int max_equalizers = 1;
476module_param(max_equalizers, int, 0);
477MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers");
478
479static int __init teql_init(void)
480{
481 int i;
482 int err = -ENODEV;
483
484 for (i = 0; i < max_equalizers; i++) {
485 struct net_device *dev;
486 struct teql_master *master;
487
488 dev = alloc_netdev(sizeof(struct teql_master),
489 "teql%d", teql_master_setup);
490 if (!dev) {
491 err = -ENOMEM;
492 break;
493 }
494
495 if ((err = register_netdev(dev))) {
496 free_netdev(dev);
497 break;
498 }
499
500 master = netdev_priv(dev);
501
502 strlcpy(master->qops.id, dev->name, IFNAMSIZ);
503 err = register_qdisc(&master->qops);
504
505 if (err) {
506 unregister_netdev(dev);
507 free_netdev(dev);
508 break;
509 }
510
511 list_add_tail(&master->master_list, &master_dev_list);
512 }
513 return i ? 0 : err;
514}
515
516static void __exit teql_exit(void)
517{
518 struct teql_master *master, *nxt;
519
520 list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) {
521
522 list_del(&master->master_list);
523
524 unregister_qdisc(&master->qops);
525 unregister_netdev(master->dev);
526 free_netdev(master->dev);
527 }
528}
529
530module_init(teql_init);
531module_exit(teql_exit);
532
533MODULE_LICENSE("GPL");