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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 sch->q.qlen = 0;
128}
129
130static void
131teql_destroy(struct Qdisc *sch)
132{
133 struct Qdisc *q, *prev;
134 struct teql_sched_data *dat = qdisc_priv(sch);
135 struct teql_master *master = dat->m;
136
137 prev = master->slaves;
138 if (prev) {
139 do {
140 q = NEXT_SLAVE(prev);
141 if (q == sch) {
142 NEXT_SLAVE(prev) = NEXT_SLAVE(q);
143 if (q == master->slaves) {
144 master->slaves = NEXT_SLAVE(q);
145 if (q == master->slaves) {
146 struct netdev_queue *txq;
147 spinlock_t *root_lock;
148
149 txq = netdev_get_tx_queue(master->dev, 0);
150 master->slaves = NULL;
151
152 root_lock = qdisc_root_sleeping_lock(rtnl_dereference(txq->qdisc));
153 spin_lock_bh(root_lock);
154 qdisc_reset(rtnl_dereference(txq->qdisc));
155 spin_unlock_bh(root_lock);
156 }
157 }
158 skb_queue_purge(&dat->q);
159 break;
160 }
161
162 } while ((prev = q) != master->slaves);
163 }
164}
165
166static int teql_qdisc_init(struct Qdisc *sch, struct nlattr *opt,
167 struct netlink_ext_ack *extack)
168{
169 struct net_device *dev = qdisc_dev(sch);
170 struct teql_master *m = (struct teql_master *)sch->ops;
171 struct teql_sched_data *q = qdisc_priv(sch);
172
173 if (dev->hard_header_len > m->dev->hard_header_len)
174 return -EINVAL;
175
176 if (m->dev == dev)
177 return -ELOOP;
178
179 q->m = m;
180
181 skb_queue_head_init(&q->q);
182
183 if (m->slaves) {
184 if (m->dev->flags & IFF_UP) {
185 if ((m->dev->flags & IFF_POINTOPOINT &&
186 !(dev->flags & IFF_POINTOPOINT)) ||
187 (m->dev->flags & IFF_BROADCAST &&
188 !(dev->flags & IFF_BROADCAST)) ||
189 (m->dev->flags & IFF_MULTICAST &&
190 !(dev->flags & IFF_MULTICAST)) ||
191 dev->mtu < m->dev->mtu)
192 return -EINVAL;
193 } else {
194 if (!(dev->flags&IFF_POINTOPOINT))
195 m->dev->flags &= ~IFF_POINTOPOINT;
196 if (!(dev->flags&IFF_BROADCAST))
197 m->dev->flags &= ~IFF_BROADCAST;
198 if (!(dev->flags&IFF_MULTICAST))
199 m->dev->flags &= ~IFF_MULTICAST;
200 if (dev->mtu < m->dev->mtu)
201 m->dev->mtu = dev->mtu;
202 }
203 q->next = NEXT_SLAVE(m->slaves);
204 NEXT_SLAVE(m->slaves) = sch;
205 } else {
206 q->next = sch;
207 m->slaves = sch;
208 m->dev->mtu = dev->mtu;
209 m->dev->flags = (m->dev->flags&~FMASK)|(dev->flags&FMASK);
210 }
211 return 0;
212}
213
214
215static int
216__teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res,
217 struct net_device *dev, struct netdev_queue *txq,
218 struct dst_entry *dst)
219{
220 struct neighbour *n;
221 int err = 0;
222
223 n = dst_neigh_lookup_skb(dst, skb);
224 if (!n)
225 return -ENOENT;
226
227 if (dst->dev != dev) {
228 struct neighbour *mn;
229
230 mn = __neigh_lookup_errno(n->tbl, n->primary_key, dev);
231 neigh_release(n);
232 if (IS_ERR(mn))
233 return PTR_ERR(mn);
234 n = mn;
235 }
236
237 if (neigh_event_send(n, skb_res) == 0) {
238 int err;
239 char haddr[MAX_ADDR_LEN];
240
241 neigh_ha_snapshot(haddr, n, dev);
242 err = dev_hard_header(skb, dev, ntohs(tc_skb_protocol(skb)),
243 haddr, NULL, skb->len);
244
245 if (err < 0)
246 err = -EINVAL;
247 } else {
248 err = (skb_res == NULL) ? -EAGAIN : 1;
249 }
250 neigh_release(n);
251 return err;
252}
253
254static inline int teql_resolve(struct sk_buff *skb,
255 struct sk_buff *skb_res,
256 struct net_device *dev,
257 struct netdev_queue *txq)
258{
259 struct dst_entry *dst = skb_dst(skb);
260 int res;
261
262 if (rcu_access_pointer(txq->qdisc) == &noop_qdisc)
263 return -ENODEV;
264
265 if (!dev->header_ops || !dst)
266 return 0;
267
268 rcu_read_lock();
269 res = __teql_resolve(skb, skb_res, dev, txq, dst);
270 rcu_read_unlock();
271
272 return res;
273}
274
275static netdev_tx_t teql_master_xmit(struct sk_buff *skb, struct net_device *dev)
276{
277 struct teql_master *master = netdev_priv(dev);
278 struct Qdisc *start, *q;
279 int busy;
280 int nores;
281 int subq = skb_get_queue_mapping(skb);
282 struct sk_buff *skb_res = NULL;
283
284 start = master->slaves;
285
286restart:
287 nores = 0;
288 busy = 0;
289
290 q = start;
291 if (!q)
292 goto drop;
293
294 do {
295 struct net_device *slave = qdisc_dev(q);
296 struct netdev_queue *slave_txq = netdev_get_tx_queue(slave, 0);
297
298 if (slave_txq->qdisc_sleeping != q)
299 continue;
300 if (netif_xmit_stopped(netdev_get_tx_queue(slave, subq)) ||
301 !netif_running(slave)) {
302 busy = 1;
303 continue;
304 }
305
306 switch (teql_resolve(skb, skb_res, slave, slave_txq)) {
307 case 0:
308 if (__netif_tx_trylock(slave_txq)) {
309 unsigned int length = qdisc_pkt_len(skb);
310
311 if (!netif_xmit_frozen_or_stopped(slave_txq) &&
312 netdev_start_xmit(skb, slave, slave_txq, false) ==
313 NETDEV_TX_OK) {
314 __netif_tx_unlock(slave_txq);
315 master->slaves = NEXT_SLAVE(q);
316 netif_wake_queue(dev);
317 master->tx_packets++;
318 master->tx_bytes += length;
319 return NETDEV_TX_OK;
320 }
321 __netif_tx_unlock(slave_txq);
322 }
323 if (netif_xmit_stopped(netdev_get_tx_queue(dev, 0)))
324 busy = 1;
325 break;
326 case 1:
327 master->slaves = NEXT_SLAVE(q);
328 return NETDEV_TX_OK;
329 default:
330 nores = 1;
331 break;
332 }
333 __skb_pull(skb, skb_network_offset(skb));
334 } while ((q = NEXT_SLAVE(q)) != start);
335
336 if (nores && skb_res == NULL) {
337 skb_res = skb;
338 goto restart;
339 }
340
341 if (busy) {
342 netif_stop_queue(dev);
343 return NETDEV_TX_BUSY;
344 }
345 master->tx_errors++;
346
347drop:
348 master->tx_dropped++;
349 dev_kfree_skb(skb);
350 return NETDEV_TX_OK;
351}
352
353static int teql_master_open(struct net_device *dev)
354{
355 struct Qdisc *q;
356 struct teql_master *m = netdev_priv(dev);
357 int mtu = 0xFFFE;
358 unsigned int flags = IFF_NOARP | IFF_MULTICAST;
359
360 if (m->slaves == NULL)
361 return -EUNATCH;
362
363 flags = FMASK;
364
365 q = m->slaves;
366 do {
367 struct net_device *slave = qdisc_dev(q);
368
369 if (slave == NULL)
370 return -EUNATCH;
371
372 if (slave->mtu < mtu)
373 mtu = slave->mtu;
374 if (slave->hard_header_len > LL_MAX_HEADER)
375 return -EINVAL;
376
377 /* If all the slaves are BROADCAST, master is BROADCAST
378 If all the slaves are PtP, master is PtP
379 Otherwise, master is NBMA.
380 */
381 if (!(slave->flags&IFF_POINTOPOINT))
382 flags &= ~IFF_POINTOPOINT;
383 if (!(slave->flags&IFF_BROADCAST))
384 flags &= ~IFF_BROADCAST;
385 if (!(slave->flags&IFF_MULTICAST))
386 flags &= ~IFF_MULTICAST;
387 } while ((q = NEXT_SLAVE(q)) != m->slaves);
388
389 m->dev->mtu = mtu;
390 m->dev->flags = (m->dev->flags&~FMASK) | flags;
391 netif_start_queue(m->dev);
392 return 0;
393}
394
395static int teql_master_close(struct net_device *dev)
396{
397 netif_stop_queue(dev);
398 return 0;
399}
400
401static void teql_master_stats64(struct net_device *dev,
402 struct rtnl_link_stats64 *stats)
403{
404 struct teql_master *m = netdev_priv(dev);
405
406 stats->tx_packets = m->tx_packets;
407 stats->tx_bytes = m->tx_bytes;
408 stats->tx_errors = m->tx_errors;
409 stats->tx_dropped = m->tx_dropped;
410}
411
412static int teql_master_mtu(struct net_device *dev, int new_mtu)
413{
414 struct teql_master *m = netdev_priv(dev);
415 struct Qdisc *q;
416
417 q = m->slaves;
418 if (q) {
419 do {
420 if (new_mtu > qdisc_dev(q)->mtu)
421 return -EINVAL;
422 } while ((q = NEXT_SLAVE(q)) != m->slaves);
423 }
424
425 dev->mtu = new_mtu;
426 return 0;
427}
428
429static const struct net_device_ops teql_netdev_ops = {
430 .ndo_open = teql_master_open,
431 .ndo_stop = teql_master_close,
432 .ndo_start_xmit = teql_master_xmit,
433 .ndo_get_stats64 = teql_master_stats64,
434 .ndo_change_mtu = teql_master_mtu,
435};
436
437static __init void teql_master_setup(struct net_device *dev)
438{
439 struct teql_master *master = netdev_priv(dev);
440 struct Qdisc_ops *ops = &master->qops;
441
442 master->dev = dev;
443 ops->priv_size = sizeof(struct teql_sched_data);
444
445 ops->enqueue = teql_enqueue;
446 ops->dequeue = teql_dequeue;
447 ops->peek = teql_peek;
448 ops->init = teql_qdisc_init;
449 ops->reset = teql_reset;
450 ops->destroy = teql_destroy;
451 ops->owner = THIS_MODULE;
452
453 dev->netdev_ops = &teql_netdev_ops;
454 dev->type = ARPHRD_VOID;
455 dev->mtu = 1500;
456 dev->min_mtu = 68;
457 dev->max_mtu = 65535;
458 dev->tx_queue_len = 100;
459 dev->flags = IFF_NOARP;
460 dev->hard_header_len = LL_MAX_HEADER;
461 netif_keep_dst(dev);
462}
463
464static LIST_HEAD(master_dev_list);
465static int max_equalizers = 1;
466module_param(max_equalizers, int, 0);
467MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers");
468
469static int __init teql_init(void)
470{
471 int i;
472 int err = -ENODEV;
473
474 for (i = 0; i < max_equalizers; i++) {
475 struct net_device *dev;
476 struct teql_master *master;
477
478 dev = alloc_netdev(sizeof(struct teql_master), "teql%d",
479 NET_NAME_UNKNOWN, teql_master_setup);
480 if (!dev) {
481 err = -ENOMEM;
482 break;
483 }
484
485 if ((err = register_netdev(dev))) {
486 free_netdev(dev);
487 break;
488 }
489
490 master = netdev_priv(dev);
491
492 strlcpy(master->qops.id, dev->name, IFNAMSIZ);
493 err = register_qdisc(&master->qops);
494
495 if (err) {
496 unregister_netdev(dev);
497 free_netdev(dev);
498 break;
499 }
500
501 list_add_tail(&master->master_list, &master_dev_list);
502 }
503 return i ? 0 : err;
504}
505
506static void __exit teql_exit(void)
507{
508 struct teql_master *master, *nxt;
509
510 list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) {
511
512 list_del(&master->master_list);
513
514 unregister_qdisc(&master->qops);
515 unregister_netdev(master->dev);
516 free_netdev(master->dev);
517 }
518}
519
520module_init(teql_init);
521module_exit(teql_exit);
522
523MODULE_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");