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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// 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 (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 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");