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1/* Copyright 2011-2013 Autronica Fire and Security AS
2 *
3 * This program is free software; you can redistribute it and/or modify it
4 * under the terms of the GNU General Public License as published by the Free
5 * Software Foundation; either version 2 of the License, or (at your option)
6 * any later version.
7 *
8 * Author(s):
9 * 2011-2013 Arvid Brodin, arvid.brodin@xdin.com
10 *
11 * This file contains device methods for creating, using and destroying
12 * virtual HSR devices.
13 */
14
15#include <linux/netdevice.h>
16#include <linux/skbuff.h>
17#include <linux/etherdevice.h>
18#include <linux/if_arp.h>
19#include <linux/rtnetlink.h>
20#include <linux/pkt_sched.h>
21#include "hsr_device.h"
22#include "hsr_framereg.h"
23#include "hsr_main.h"
24
25
26static bool is_admin_up(struct net_device *dev)
27{
28 return dev && (dev->flags & IFF_UP);
29}
30
31static bool is_slave_up(struct net_device *dev)
32{
33 return dev && is_admin_up(dev) && netif_oper_up(dev);
34}
35
36static void __hsr_set_operstate(struct net_device *dev, int transition)
37{
38 write_lock_bh(&dev_base_lock);
39 if (dev->operstate != transition) {
40 dev->operstate = transition;
41 write_unlock_bh(&dev_base_lock);
42 netdev_state_change(dev);
43 } else {
44 write_unlock_bh(&dev_base_lock);
45 }
46}
47
48void hsr_set_operstate(struct net_device *hsr_dev, struct net_device *slave1,
49 struct net_device *slave2)
50{
51 if (!is_admin_up(hsr_dev)) {
52 __hsr_set_operstate(hsr_dev, IF_OPER_DOWN);
53 return;
54 }
55
56 if (is_slave_up(slave1) || is_slave_up(slave2))
57 __hsr_set_operstate(hsr_dev, IF_OPER_UP);
58 else
59 __hsr_set_operstate(hsr_dev, IF_OPER_LOWERLAYERDOWN);
60}
61
62void hsr_set_carrier(struct net_device *hsr_dev, struct net_device *slave1,
63 struct net_device *slave2)
64{
65 if (is_slave_up(slave1) || is_slave_up(slave2))
66 netif_carrier_on(hsr_dev);
67 else
68 netif_carrier_off(hsr_dev);
69}
70
71
72void hsr_check_announce(struct net_device *hsr_dev, int old_operstate)
73{
74 struct hsr_priv *hsr_priv;
75
76 hsr_priv = netdev_priv(hsr_dev);
77
78 if ((hsr_dev->operstate == IF_OPER_UP) && (old_operstate != IF_OPER_UP)) {
79 /* Went up */
80 hsr_priv->announce_count = 0;
81 hsr_priv->announce_timer.expires = jiffies +
82 msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
83 add_timer(&hsr_priv->announce_timer);
84 }
85
86 if ((hsr_dev->operstate != IF_OPER_UP) && (old_operstate == IF_OPER_UP))
87 /* Went down */
88 del_timer(&hsr_priv->announce_timer);
89}
90
91
92int hsr_get_max_mtu(struct hsr_priv *hsr_priv)
93{
94 int mtu_max;
95
96 if (hsr_priv->slave[0] && hsr_priv->slave[1])
97 mtu_max = min(hsr_priv->slave[0]->mtu, hsr_priv->slave[1]->mtu);
98 else if (hsr_priv->slave[0])
99 mtu_max = hsr_priv->slave[0]->mtu;
100 else if (hsr_priv->slave[1])
101 mtu_max = hsr_priv->slave[1]->mtu;
102 else
103 mtu_max = HSR_TAGLEN;
104
105 return mtu_max - HSR_TAGLEN;
106}
107
108static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
109{
110 struct hsr_priv *hsr_priv;
111
112 hsr_priv = netdev_priv(dev);
113
114 if (new_mtu > hsr_get_max_mtu(hsr_priv)) {
115 netdev_info(hsr_priv->dev, "A HSR master's MTU cannot be greater than the smallest MTU of its slaves minus the HSR Tag length (%d octets).\n",
116 HSR_TAGLEN);
117 return -EINVAL;
118 }
119
120 dev->mtu = new_mtu;
121
122 return 0;
123}
124
125static int hsr_dev_open(struct net_device *dev)
126{
127 struct hsr_priv *hsr_priv;
128 int i;
129 char *slave_name;
130
131 hsr_priv = netdev_priv(dev);
132
133 for (i = 0; i < HSR_MAX_SLAVE; i++) {
134 if (hsr_priv->slave[i])
135 slave_name = hsr_priv->slave[i]->name;
136 else
137 slave_name = "null";
138
139 if (!is_slave_up(hsr_priv->slave[i]))
140 netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a working HSR network\n",
141 'A' + i, slave_name);
142 }
143
144 return 0;
145}
146
147static int hsr_dev_close(struct net_device *dev)
148{
149 /* Nothing to do here. We could try to restore the state of the slaves
150 * to what they were before being changed by the hsr master dev's state,
151 * but they might have been changed manually in the mean time too, so
152 * taking them up or down here might be confusing and is probably not a
153 * good idea.
154 */
155 return 0;
156}
157
158
159static void hsr_fill_tag(struct hsr_ethhdr *hsr_ethhdr, struct hsr_priv *hsr_priv)
160{
161 unsigned long irqflags;
162
163 /* IEC 62439-1:2010, p 48, says the 4-bit "path" field can take values
164 * between 0001-1001 ("ring identifier", for regular HSR frames),
165 * or 1111 ("HSR management", supervision frames). Unfortunately, the
166 * spec writers forgot to explain what a "ring identifier" is, or
167 * how it is used. So we just set this to 0001 for regular frames,
168 * and 1111 for supervision frames.
169 */
170 set_hsr_tag_path(&hsr_ethhdr->hsr_tag, 0x1);
171
172 /* IEC 62439-1:2010, p 12: "The link service data unit in an Ethernet
173 * frame is the content of the frame located between the Length/Type
174 * field and the Frame Check Sequence."
175 *
176 * IEC 62439-3, p 48, specifies the "original LPDU" to include the
177 * original "LT" field (what "LT" means is not explained anywhere as
178 * far as I can see - perhaps "Length/Type"?). So LSDU_size might
179 * equal original length + 2.
180 * Also, the fact that this field is not used anywhere (might be used
181 * by a RedBox connecting HSR and PRP nets?) means I cannot test its
182 * correctness. Instead of guessing, I set this to 0 here, to make any
183 * problems immediately apparent. Anyone using this driver with PRP/HSR
184 * RedBoxes might need to fix this...
185 */
186 set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, 0);
187
188 spin_lock_irqsave(&hsr_priv->seqnr_lock, irqflags);
189 hsr_ethhdr->hsr_tag.sequence_nr = htons(hsr_priv->sequence_nr);
190 hsr_priv->sequence_nr++;
191 spin_unlock_irqrestore(&hsr_priv->seqnr_lock, irqflags);
192
193 hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
194
195 hsr_ethhdr->ethhdr.h_proto = htons(ETH_P_PRP);
196}
197
198static int slave_xmit(struct sk_buff *skb, struct hsr_priv *hsr_priv,
199 enum hsr_dev_idx dev_idx)
200{
201 struct hsr_ethhdr *hsr_ethhdr;
202
203 hsr_ethhdr = (struct hsr_ethhdr *) skb->data;
204
205 skb->dev = hsr_priv->slave[dev_idx];
206
207 hsr_addr_subst_dest(hsr_priv, &hsr_ethhdr->ethhdr, dev_idx);
208
209 /* Address substitution (IEC62439-3 pp 26, 50): replace mac
210 * address of outgoing frame with that of the outgoing slave's.
211 */
212 ether_addr_copy(hsr_ethhdr->ethhdr.h_source, skb->dev->dev_addr);
213
214 return dev_queue_xmit(skb);
215}
216
217
218static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
219{
220 struct hsr_priv *hsr_priv;
221 struct hsr_ethhdr *hsr_ethhdr;
222 struct sk_buff *skb2;
223 int res1, res2;
224
225 hsr_priv = netdev_priv(dev);
226 hsr_ethhdr = (struct hsr_ethhdr *) skb->data;
227
228 if ((skb->protocol != htons(ETH_P_PRP)) ||
229 (hsr_ethhdr->ethhdr.h_proto != htons(ETH_P_PRP))) {
230 hsr_fill_tag(hsr_ethhdr, hsr_priv);
231 skb->protocol = htons(ETH_P_PRP);
232 }
233
234 skb2 = pskb_copy(skb, GFP_ATOMIC);
235
236 res1 = NET_XMIT_DROP;
237 if (likely(hsr_priv->slave[HSR_DEV_SLAVE_A]))
238 res1 = slave_xmit(skb, hsr_priv, HSR_DEV_SLAVE_A);
239
240 res2 = NET_XMIT_DROP;
241 if (likely(skb2 && hsr_priv->slave[HSR_DEV_SLAVE_B]))
242 res2 = slave_xmit(skb2, hsr_priv, HSR_DEV_SLAVE_B);
243
244 if (likely(res1 == NET_XMIT_SUCCESS || res1 == NET_XMIT_CN ||
245 res2 == NET_XMIT_SUCCESS || res2 == NET_XMIT_CN)) {
246 hsr_priv->dev->stats.tx_packets++;
247 hsr_priv->dev->stats.tx_bytes += skb->len;
248 } else {
249 hsr_priv->dev->stats.tx_dropped++;
250 }
251
252 return NETDEV_TX_OK;
253}
254
255
256static int hsr_header_create(struct sk_buff *skb, struct net_device *dev,
257 unsigned short type, const void *daddr,
258 const void *saddr, unsigned int len)
259{
260 int res;
261
262 /* Make room for the HSR tag now. We will fill it in later (in
263 * hsr_dev_xmit)
264 */
265 if (skb_headroom(skb) < HSR_TAGLEN + ETH_HLEN)
266 return -ENOBUFS;
267 skb_push(skb, HSR_TAGLEN);
268
269 /* To allow VLAN/HSR combos we should probably use
270 * res = dev_hard_header(skb, dev, type, daddr, saddr, len + HSR_TAGLEN);
271 * here instead. It would require other changes too, though - e.g.
272 * separate headers for each slave etc...
273 */
274 res = eth_header(skb, dev, type, daddr, saddr, len + HSR_TAGLEN);
275 if (res <= 0)
276 return res;
277 skb_reset_mac_header(skb);
278
279 return res + HSR_TAGLEN;
280}
281
282
283static const struct header_ops hsr_header_ops = {
284 .create = hsr_header_create,
285 .parse = eth_header_parse,
286};
287
288
289/* HSR:2010 supervision frames should be padded so that the whole frame,
290 * including headers and FCS, is 64 bytes (without VLAN).
291 */
292static int hsr_pad(int size)
293{
294 const int min_size = ETH_ZLEN - HSR_TAGLEN - ETH_HLEN;
295
296 if (size >= min_size)
297 return size;
298 return min_size;
299}
300
301static void send_hsr_supervision_frame(struct net_device *hsr_dev, u8 type)
302{
303 struct hsr_priv *hsr_priv;
304 struct sk_buff *skb;
305 int hlen, tlen;
306 struct hsr_sup_tag *hsr_stag;
307 struct hsr_sup_payload *hsr_sp;
308 unsigned long irqflags;
309
310 hlen = LL_RESERVED_SPACE(hsr_dev);
311 tlen = hsr_dev->needed_tailroom;
312 skb = alloc_skb(hsr_pad(sizeof(struct hsr_sup_payload)) + hlen + tlen,
313 GFP_ATOMIC);
314
315 if (skb == NULL)
316 return;
317
318 hsr_priv = netdev_priv(hsr_dev);
319
320 skb_reserve(skb, hlen);
321
322 skb->dev = hsr_dev;
323 skb->protocol = htons(ETH_P_PRP);
324 skb->priority = TC_PRIO_CONTROL;
325
326 if (dev_hard_header(skb, skb->dev, ETH_P_PRP,
327 hsr_priv->sup_multicast_addr,
328 skb->dev->dev_addr, skb->len) < 0)
329 goto out;
330
331 skb_pull(skb, sizeof(struct ethhdr));
332 hsr_stag = (typeof(hsr_stag)) skb->data;
333
334 set_hsr_stag_path(hsr_stag, 0xf);
335 set_hsr_stag_HSR_Ver(hsr_stag, 0);
336
337 spin_lock_irqsave(&hsr_priv->seqnr_lock, irqflags);
338 hsr_stag->sequence_nr = htons(hsr_priv->sequence_nr);
339 hsr_priv->sequence_nr++;
340 spin_unlock_irqrestore(&hsr_priv->seqnr_lock, irqflags);
341
342 hsr_stag->HSR_TLV_Type = type;
343 hsr_stag->HSR_TLV_Length = 12;
344
345 skb_push(skb, sizeof(struct ethhdr));
346
347 /* Payload: MacAddressA */
348 hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(*hsr_sp));
349 ether_addr_copy(hsr_sp->MacAddressA, hsr_dev->dev_addr);
350
351 dev_queue_xmit(skb);
352 return;
353
354out:
355 kfree_skb(skb);
356}
357
358
359/* Announce (supervision frame) timer function
360 */
361static void hsr_announce(unsigned long data)
362{
363 struct hsr_priv *hsr_priv;
364
365 hsr_priv = (struct hsr_priv *) data;
366
367 if (hsr_priv->announce_count < 3) {
368 send_hsr_supervision_frame(hsr_priv->dev, HSR_TLV_ANNOUNCE);
369 hsr_priv->announce_count++;
370 } else {
371 send_hsr_supervision_frame(hsr_priv->dev, HSR_TLV_LIFE_CHECK);
372 }
373
374 if (hsr_priv->announce_count < 3)
375 hsr_priv->announce_timer.expires = jiffies +
376 msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
377 else
378 hsr_priv->announce_timer.expires = jiffies +
379 msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
380
381 if (is_admin_up(hsr_priv->dev))
382 add_timer(&hsr_priv->announce_timer);
383}
384
385
386static void restore_slaves(struct net_device *hsr_dev)
387{
388 struct hsr_priv *hsr_priv;
389 int i;
390 int res;
391
392 hsr_priv = netdev_priv(hsr_dev);
393
394 rtnl_lock();
395
396 /* Restore promiscuity */
397 for (i = 0; i < HSR_MAX_SLAVE; i++) {
398 if (!hsr_priv->slave[i])
399 continue;
400 res = dev_set_promiscuity(hsr_priv->slave[i], -1);
401 if (res)
402 netdev_info(hsr_dev,
403 "Cannot restore slave promiscuity (%s, %d)\n",
404 hsr_priv->slave[i]->name, res);
405 }
406
407 rtnl_unlock();
408}
409
410static void reclaim_hsr_dev(struct rcu_head *rh)
411{
412 struct hsr_priv *hsr_priv;
413
414 hsr_priv = container_of(rh, struct hsr_priv, rcu_head);
415 free_netdev(hsr_priv->dev);
416}
417
418
419/* According to comments in the declaration of struct net_device, this function
420 * is "Called from unregister, can be used to call free_netdev". Ok then...
421 */
422static void hsr_dev_destroy(struct net_device *hsr_dev)
423{
424 struct hsr_priv *hsr_priv;
425
426 hsr_priv = netdev_priv(hsr_dev);
427
428 del_timer(&hsr_priv->announce_timer);
429 unregister_hsr_master(hsr_priv); /* calls list_del_rcu on hsr_priv */
430 restore_slaves(hsr_dev);
431 call_rcu(&hsr_priv->rcu_head, reclaim_hsr_dev); /* reclaim hsr_priv */
432}
433
434static const struct net_device_ops hsr_device_ops = {
435 .ndo_change_mtu = hsr_dev_change_mtu,
436 .ndo_open = hsr_dev_open,
437 .ndo_stop = hsr_dev_close,
438 .ndo_start_xmit = hsr_dev_xmit,
439};
440
441
442void hsr_dev_setup(struct net_device *dev)
443{
444 random_ether_addr(dev->dev_addr);
445
446 ether_setup(dev);
447 dev->header_ops = &hsr_header_ops;
448 dev->netdev_ops = &hsr_device_ops;
449 dev->tx_queue_len = 0;
450
451 dev->destructor = hsr_dev_destroy;
452}
453
454
455/* Return true if dev is a HSR master; return false otherwise.
456 */
457bool is_hsr_master(struct net_device *dev)
458{
459 return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
460}
461
462static int check_slave_ok(struct net_device *dev)
463{
464 /* Don't allow HSR on non-ethernet like devices */
465 if ((dev->flags & IFF_LOOPBACK) || (dev->type != ARPHRD_ETHER) ||
466 (dev->addr_len != ETH_ALEN)) {
467 netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
468 return -EINVAL;
469 }
470
471 /* Don't allow enslaving hsr devices */
472 if (is_hsr_master(dev)) {
473 netdev_info(dev, "Cannot create trees of HSR devices.\n");
474 return -EINVAL;
475 }
476
477 if (is_hsr_slave(dev)) {
478 netdev_info(dev, "This device is already a HSR slave.\n");
479 return -EINVAL;
480 }
481
482 if (dev->priv_flags & IFF_802_1Q_VLAN) {
483 netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
484 return -EINVAL;
485 }
486
487 /* HSR over bonded devices has not been tested, but I'm not sure it
488 * won't work...
489 */
490
491 return 0;
492}
493
494
495/* Default multicast address for HSR Supervision frames */
496static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
497 0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
498};
499
500int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
501 unsigned char multicast_spec)
502{
503 struct hsr_priv *hsr_priv;
504 int i;
505 int res;
506
507 hsr_priv = netdev_priv(hsr_dev);
508 hsr_priv->dev = hsr_dev;
509 INIT_LIST_HEAD(&hsr_priv->node_db);
510 INIT_LIST_HEAD(&hsr_priv->self_node_db);
511 for (i = 0; i < HSR_MAX_SLAVE; i++)
512 hsr_priv->slave[i] = slave[i];
513
514 spin_lock_init(&hsr_priv->seqnr_lock);
515 /* Overflow soon to find bugs easier: */
516 hsr_priv->sequence_nr = USHRT_MAX - 1024;
517
518 init_timer(&hsr_priv->announce_timer);
519 hsr_priv->announce_timer.function = hsr_announce;
520 hsr_priv->announce_timer.data = (unsigned long) hsr_priv;
521
522 ether_addr_copy(hsr_priv->sup_multicast_addr, def_multicast_addr);
523 hsr_priv->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
524
525/* FIXME: should I modify the value of these?
526 *
527 * - hsr_dev->flags - i.e.
528 * IFF_MASTER/SLAVE?
529 * - hsr_dev->priv_flags - i.e.
530 * IFF_EBRIDGE?
531 * IFF_TX_SKB_SHARING?
532 * IFF_HSR_MASTER/SLAVE?
533 */
534
535 for (i = 0; i < HSR_MAX_SLAVE; i++) {
536 res = check_slave_ok(slave[i]);
537 if (res)
538 return res;
539 }
540
541 hsr_dev->features = slave[0]->features & slave[1]->features;
542 /* Prevent recursive tx locking */
543 hsr_dev->features |= NETIF_F_LLTX;
544 /* VLAN on top of HSR needs testing and probably some work on
545 * hsr_header_create() etc.
546 */
547 hsr_dev->features |= NETIF_F_VLAN_CHALLENGED;
548
549 /* Set hsr_dev's MAC address to that of mac_slave1 */
550 ether_addr_copy(hsr_dev->dev_addr, hsr_priv->slave[0]->dev_addr);
551
552 /* Set required header length */
553 for (i = 0; i < HSR_MAX_SLAVE; i++) {
554 if (slave[i]->hard_header_len + HSR_TAGLEN >
555 hsr_dev->hard_header_len)
556 hsr_dev->hard_header_len =
557 slave[i]->hard_header_len + HSR_TAGLEN;
558 }
559
560 /* MTU */
561 for (i = 0; i < HSR_MAX_SLAVE; i++)
562 if (slave[i]->mtu - HSR_TAGLEN < hsr_dev->mtu)
563 hsr_dev->mtu = slave[i]->mtu - HSR_TAGLEN;
564
565 /* Make sure the 1st call to netif_carrier_on() gets through */
566 netif_carrier_off(hsr_dev);
567
568 /* Promiscuity */
569 for (i = 0; i < HSR_MAX_SLAVE; i++) {
570 res = dev_set_promiscuity(slave[i], 1);
571 if (res) {
572 netdev_info(hsr_dev, "Cannot set slave promiscuity (%s, %d)\n",
573 slave[i]->name, res);
574 goto fail;
575 }
576 }
577
578 /* Make sure we recognize frames from ourselves in hsr_rcv() */
579 res = hsr_create_self_node(&hsr_priv->self_node_db,
580 hsr_dev->dev_addr,
581 hsr_priv->slave[1]->dev_addr);
582 if (res < 0)
583 goto fail;
584
585 res = register_netdevice(hsr_dev);
586 if (res)
587 goto fail;
588
589 register_hsr_master(hsr_priv);
590
591 return 0;
592
593fail:
594 restore_slaves(hsr_dev);
595 return res;
596}