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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 struct Qdisc *q;
100
101 skb = __skb_dequeue(&dat->q);
102 dat_queue = netdev_get_tx_queue(dat->m->dev, 0);
103 q = rcu_dereference_bh(dat_queue->qdisc);
104
105 if (skb == NULL) {
106 struct net_device *m = qdisc_dev(q);
107 if (m) {
108 dat->m->slaves = sch;
109 netif_wake_queue(m);
110 }
111 } else {
112 qdisc_bstats_update(sch, skb);
113 }
114 sch->q.qlen = dat->q.qlen + q->q.qlen;
115 return skb;
116}
117
118static struct sk_buff *
119teql_peek(struct Qdisc *sch)
120{
121 /* teql is meant to be used as root qdisc */
122 return NULL;
123}
124
125static void
126teql_reset(struct Qdisc *sch)
127{
128 struct teql_sched_data *dat = qdisc_priv(sch);
129
130 skb_queue_purge(&dat->q);
131 sch->q.qlen = 0;
132}
133
134static void
135teql_destroy(struct Qdisc *sch)
136{
137 struct Qdisc *q, *prev;
138 struct teql_sched_data *dat = qdisc_priv(sch);
139 struct teql_master *master = dat->m;
140
141 prev = master->slaves;
142 if (prev) {
143 do {
144 q = NEXT_SLAVE(prev);
145 if (q == sch) {
146 NEXT_SLAVE(prev) = NEXT_SLAVE(q);
147 if (q == master->slaves) {
148 master->slaves = NEXT_SLAVE(q);
149 if (q == master->slaves) {
150 struct netdev_queue *txq;
151 spinlock_t *root_lock;
152
153 txq = netdev_get_tx_queue(master->dev, 0);
154 master->slaves = NULL;
155
156 root_lock = qdisc_root_sleeping_lock(rtnl_dereference(txq->qdisc));
157 spin_lock_bh(root_lock);
158 qdisc_reset(rtnl_dereference(txq->qdisc));
159 spin_unlock_bh(root_lock);
160 }
161 }
162 skb_queue_purge(&dat->q);
163 break;
164 }
165
166 } while ((prev = q) != master->slaves);
167 }
168}
169
170static int teql_qdisc_init(struct Qdisc *sch, struct nlattr *opt)
171{
172 struct net_device *dev = qdisc_dev(sch);
173 struct teql_master *m = (struct teql_master *)sch->ops;
174 struct teql_sched_data *q = qdisc_priv(sch);
175
176 if (dev->hard_header_len > m->dev->hard_header_len)
177 return -EINVAL;
178
179 if (m->dev == dev)
180 return -ELOOP;
181
182 q->m = m;
183
184 skb_queue_head_init(&q->q);
185
186 if (m->slaves) {
187 if (m->dev->flags & IFF_UP) {
188 if ((m->dev->flags & IFF_POINTOPOINT &&
189 !(dev->flags & IFF_POINTOPOINT)) ||
190 (m->dev->flags & IFF_BROADCAST &&
191 !(dev->flags & IFF_BROADCAST)) ||
192 (m->dev->flags & IFF_MULTICAST &&
193 !(dev->flags & IFF_MULTICAST)) ||
194 dev->mtu < m->dev->mtu)
195 return -EINVAL;
196 } else {
197 if (!(dev->flags&IFF_POINTOPOINT))
198 m->dev->flags &= ~IFF_POINTOPOINT;
199 if (!(dev->flags&IFF_BROADCAST))
200 m->dev->flags &= ~IFF_BROADCAST;
201 if (!(dev->flags&IFF_MULTICAST))
202 m->dev->flags &= ~IFF_MULTICAST;
203 if (dev->mtu < m->dev->mtu)
204 m->dev->mtu = dev->mtu;
205 }
206 q->next = NEXT_SLAVE(m->slaves);
207 NEXT_SLAVE(m->slaves) = sch;
208 } else {
209 q->next = sch;
210 m->slaves = sch;
211 m->dev->mtu = dev->mtu;
212 m->dev->flags = (m->dev->flags&~FMASK)|(dev->flags&FMASK);
213 }
214 return 0;
215}
216
217
218static int
219__teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res,
220 struct net_device *dev, struct netdev_queue *txq,
221 struct dst_entry *dst)
222{
223 struct neighbour *n;
224 int err = 0;
225
226 n = dst_neigh_lookup_skb(dst, skb);
227 if (!n)
228 return -ENOENT;
229
230 if (dst->dev != dev) {
231 struct neighbour *mn;
232
233 mn = __neigh_lookup_errno(n->tbl, n->primary_key, dev);
234 neigh_release(n);
235 if (IS_ERR(mn))
236 return PTR_ERR(mn);
237 n = mn;
238 }
239
240 if (neigh_event_send(n, skb_res) == 0) {
241 int err;
242 char haddr[MAX_ADDR_LEN];
243
244 neigh_ha_snapshot(haddr, n, dev);
245 err = dev_hard_header(skb, dev, ntohs(tc_skb_protocol(skb)),
246 haddr, NULL, skb->len);
247
248 if (err < 0)
249 err = -EINVAL;
250 } else {
251 err = (skb_res == NULL) ? -EAGAIN : 1;
252 }
253 neigh_release(n);
254 return err;
255}
256
257static inline int teql_resolve(struct sk_buff *skb,
258 struct sk_buff *skb_res,
259 struct net_device *dev,
260 struct netdev_queue *txq)
261{
262 struct dst_entry *dst = skb_dst(skb);
263 int res;
264
265 if (rcu_access_pointer(txq->qdisc) == &noop_qdisc)
266 return -ENODEV;
267
268 if (!dev->header_ops || !dst)
269 return 0;
270
271 rcu_read_lock();
272 res = __teql_resolve(skb, skb_res, dev, txq, dst);
273 rcu_read_unlock();
274
275 return res;
276}
277
278static netdev_tx_t teql_master_xmit(struct sk_buff *skb, struct net_device *dev)
279{
280 struct teql_master *master = netdev_priv(dev);
281 struct Qdisc *start, *q;
282 int busy;
283 int nores;
284 int subq = skb_get_queue_mapping(skb);
285 struct sk_buff *skb_res = NULL;
286
287 start = master->slaves;
288
289restart:
290 nores = 0;
291 busy = 0;
292
293 q = start;
294 if (!q)
295 goto drop;
296
297 do {
298 struct net_device *slave = qdisc_dev(q);
299 struct netdev_queue *slave_txq = netdev_get_tx_queue(slave, 0);
300
301 if (slave_txq->qdisc_sleeping != q)
302 continue;
303 if (netif_xmit_stopped(netdev_get_tx_queue(slave, subq)) ||
304 !netif_running(slave)) {
305 busy = 1;
306 continue;
307 }
308
309 switch (teql_resolve(skb, skb_res, slave, slave_txq)) {
310 case 0:
311 if (__netif_tx_trylock(slave_txq)) {
312 unsigned int length = qdisc_pkt_len(skb);
313
314 if (!netif_xmit_frozen_or_stopped(slave_txq) &&
315 netdev_start_xmit(skb, slave, slave_txq, false) ==
316 NETDEV_TX_OK) {
317 __netif_tx_unlock(slave_txq);
318 master->slaves = NEXT_SLAVE(q);
319 netif_wake_queue(dev);
320 master->tx_packets++;
321 master->tx_bytes += length;
322 return NETDEV_TX_OK;
323 }
324 __netif_tx_unlock(slave_txq);
325 }
326 if (netif_xmit_stopped(netdev_get_tx_queue(dev, 0)))
327 busy = 1;
328 break;
329 case 1:
330 master->slaves = NEXT_SLAVE(q);
331 return NETDEV_TX_OK;
332 default:
333 nores = 1;
334 break;
335 }
336 __skb_pull(skb, skb_network_offset(skb));
337 } while ((q = NEXT_SLAVE(q)) != start);
338
339 if (nores && skb_res == NULL) {
340 skb_res = skb;
341 goto restart;
342 }
343
344 if (busy) {
345 netif_stop_queue(dev);
346 return NETDEV_TX_BUSY;
347 }
348 master->tx_errors++;
349
350drop:
351 master->tx_dropped++;
352 dev_kfree_skb(skb);
353 return NETDEV_TX_OK;
354}
355
356static int teql_master_open(struct net_device *dev)
357{
358 struct Qdisc *q;
359 struct teql_master *m = netdev_priv(dev);
360 int mtu = 0xFFFE;
361 unsigned int flags = IFF_NOARP | IFF_MULTICAST;
362
363 if (m->slaves == NULL)
364 return -EUNATCH;
365
366 flags = FMASK;
367
368 q = m->slaves;
369 do {
370 struct net_device *slave = qdisc_dev(q);
371
372 if (slave == NULL)
373 return -EUNATCH;
374
375 if (slave->mtu < mtu)
376 mtu = slave->mtu;
377 if (slave->hard_header_len > LL_MAX_HEADER)
378 return -EINVAL;
379
380 /* If all the slaves are BROADCAST, master is BROADCAST
381 If all the slaves are PtP, master is PtP
382 Otherwise, master is NBMA.
383 */
384 if (!(slave->flags&IFF_POINTOPOINT))
385 flags &= ~IFF_POINTOPOINT;
386 if (!(slave->flags&IFF_BROADCAST))
387 flags &= ~IFF_BROADCAST;
388 if (!(slave->flags&IFF_MULTICAST))
389 flags &= ~IFF_MULTICAST;
390 } while ((q = NEXT_SLAVE(q)) != m->slaves);
391
392 m->dev->mtu = mtu;
393 m->dev->flags = (m->dev->flags&~FMASK) | flags;
394 netif_start_queue(m->dev);
395 return 0;
396}
397
398static int teql_master_close(struct net_device *dev)
399{
400 netif_stop_queue(dev);
401 return 0;
402}
403
404static struct rtnl_link_stats64 *teql_master_stats64(struct net_device *dev,
405 struct rtnl_link_stats64 *stats)
406{
407 struct teql_master *m = netdev_priv(dev);
408
409 stats->tx_packets = m->tx_packets;
410 stats->tx_bytes = m->tx_bytes;
411 stats->tx_errors = m->tx_errors;
412 stats->tx_dropped = m->tx_dropped;
413 return stats;
414}
415
416static int teql_master_mtu(struct net_device *dev, int new_mtu)
417{
418 struct teql_master *m = netdev_priv(dev);
419 struct Qdisc *q;
420
421 if (new_mtu < 68)
422 return -EINVAL;
423
424 q = m->slaves;
425 if (q) {
426 do {
427 if (new_mtu > qdisc_dev(q)->mtu)
428 return -EINVAL;
429 } while ((q = NEXT_SLAVE(q)) != m->slaves);
430 }
431
432 dev->mtu = new_mtu;
433 return 0;
434}
435
436static const struct net_device_ops teql_netdev_ops = {
437 .ndo_open = teql_master_open,
438 .ndo_stop = teql_master_close,
439 .ndo_start_xmit = teql_master_xmit,
440 .ndo_get_stats64 = teql_master_stats64,
441 .ndo_change_mtu = teql_master_mtu,
442};
443
444static __init void teql_master_setup(struct net_device *dev)
445{
446 struct teql_master *master = netdev_priv(dev);
447 struct Qdisc_ops *ops = &master->qops;
448
449 master->dev = dev;
450 ops->priv_size = sizeof(struct teql_sched_data);
451
452 ops->enqueue = teql_enqueue;
453 ops->dequeue = teql_dequeue;
454 ops->peek = teql_peek;
455 ops->init = teql_qdisc_init;
456 ops->reset = teql_reset;
457 ops->destroy = teql_destroy;
458 ops->owner = THIS_MODULE;
459
460 dev->netdev_ops = &teql_netdev_ops;
461 dev->type = ARPHRD_VOID;
462 dev->mtu = 1500;
463 dev->tx_queue_len = 100;
464 dev->flags = IFF_NOARP;
465 dev->hard_header_len = LL_MAX_HEADER;
466 netif_keep_dst(dev);
467}
468
469static LIST_HEAD(master_dev_list);
470static int max_equalizers = 1;
471module_param(max_equalizers, int, 0);
472MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers");
473
474static int __init teql_init(void)
475{
476 int i;
477 int err = -ENODEV;
478
479 for (i = 0; i < max_equalizers; i++) {
480 struct net_device *dev;
481 struct teql_master *master;
482
483 dev = alloc_netdev(sizeof(struct teql_master), "teql%d",
484 NET_NAME_UNKNOWN, teql_master_setup);
485 if (!dev) {
486 err = -ENOMEM;
487 break;
488 }
489
490 if ((err = register_netdev(dev))) {
491 free_netdev(dev);
492 break;
493 }
494
495 master = netdev_priv(dev);
496
497 strlcpy(master->qops.id, dev->name, IFNAMSIZ);
498 err = register_qdisc(&master->qops);
499
500 if (err) {
501 unregister_netdev(dev);
502 free_netdev(dev);
503 break;
504 }
505
506 list_add_tail(&master->master_list, &master_dev_list);
507 }
508 return i ? 0 : err;
509}
510
511static void __exit teql_exit(void)
512{
513 struct teql_master *master, *nxt;
514
515 list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) {
516
517 list_del(&master->master_list);
518
519 unregister_qdisc(&master->qops);
520 unregister_netdev(master->dev);
521 free_netdev(master->dev);
522 }
523}
524
525module_init(teql_init);
526module_exit(teql_exit);
527
528MODULE_LICENSE("GPL");
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 < READ_ONCE(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 (rcu_access_pointer(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 WRITE_ONCE(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");
526MODULE_DESCRIPTION("True (or trivial) link equalizer qdisc");