summaryrefslogtreecommitdiffstats
path: root/net/hsr/hsr_device.c
blob: 1fc4ea20752e035436f0e042a527c9a2a89a94e8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
/* Copyright 2011-2014 Autronica Fire and Security AS
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * Author(s):
 *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
 *
 * This file contains device methods for creating, using and destroying
 * virtual HSR devices.
 */

#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <linux/pkt_sched.h>
#include "hsr_device.h"
#include "hsr_slave.h"
#include "hsr_framereg.h"
#include "hsr_main.h"


static bool is_admin_up(struct net_device *dev)
{
	return dev && (dev->flags & IFF_UP);
}

static bool is_slave_up(struct net_device *dev)
{
	return dev && is_admin_up(dev) && netif_oper_up(dev);
}

static void __hsr_set_operstate(struct net_device *dev, int transition)
{
	write_lock_bh(&dev_base_lock);
	if (dev->operstate != transition) {
		dev->operstate = transition;
		write_unlock_bh(&dev_base_lock);
		netdev_state_change(dev);
	} else {
		write_unlock_bh(&dev_base_lock);
	}
}

static void hsr_set_operstate(struct hsr_port *master, bool has_carrier)
{
	if (!is_admin_up(master->dev)) {
		__hsr_set_operstate(master->dev, IF_OPER_DOWN);
		return;
	}

	if (has_carrier)
		__hsr_set_operstate(master->dev, IF_OPER_UP);
	else
		__hsr_set_operstate(master->dev, IF_OPER_LOWERLAYERDOWN);
}

static bool hsr_check_carrier(struct hsr_port *master)
{
	struct hsr_port *port;
	bool has_carrier;

	has_carrier = false;

	rcu_read_lock();
	hsr_for_each_port(master->hsr, port)
		if ((port->type != HSR_PT_MASTER) && is_slave_up(port->dev)) {
			has_carrier = true;
			break;
		}
	rcu_read_unlock();

	if (has_carrier)
		netif_carrier_on(master->dev);
	else
		netif_carrier_off(master->dev);

	return has_carrier;
}


static void hsr_check_announce(struct net_device *hsr_dev,
			       unsigned char old_operstate)
{
	struct hsr_priv *hsr;

	hsr = netdev_priv(hsr_dev);

	if ((hsr_dev->operstate == IF_OPER_UP) && (old_operstate != IF_OPER_UP)) {
		/* Went up */
		hsr->announce_count = 0;
		hsr->announce_timer.expires = jiffies +
				msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
		add_timer(&hsr->announce_timer);
	}

	if ((hsr_dev->operstate != IF_OPER_UP) && (old_operstate == IF_OPER_UP))
		/* Went down */
		del_timer(&hsr->announce_timer);
}

void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
{
	struct hsr_port *master;
	unsigned char old_operstate;
	bool has_carrier;

	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
	/* netif_stacked_transfer_operstate() cannot be used here since
	 * it doesn't set IF_OPER_LOWERLAYERDOWN (?)
	 */
	old_operstate = master->dev->operstate;
	has_carrier = hsr_check_carrier(master);
	hsr_set_operstate(master, has_carrier);
	hsr_check_announce(master->dev, old_operstate);
}

int hsr_get_max_mtu(struct hsr_priv *hsr)
{
	unsigned int mtu_max;
	struct hsr_port *port;

	mtu_max = ETH_DATA_LEN;
	rcu_read_lock();
	hsr_for_each_port(hsr, port)
		if (port->type != HSR_PT_MASTER)
			mtu_max = min(port->dev->mtu, mtu_max);
	rcu_read_unlock();

	if (mtu_max < HSR_HLEN)
		return 0;
	return mtu_max - HSR_HLEN;
}


static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
{
	struct hsr_priv *hsr;
	struct hsr_port *master;

	hsr = netdev_priv(dev);
	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);

	if (new_mtu > hsr_get_max_mtu(hsr)) {
		netdev_info(master->dev, "A HSR master's MTU cannot be greater than the smallest MTU of its slaves minus the HSR Tag length (%d octets).\n",
			    HSR_HLEN);
		return -EINVAL;
	}

	dev->mtu = new_mtu;

	return 0;
}

static int hsr_dev_open(struct net_device *dev)
{
	struct hsr_priv *hsr;
	struct hsr_port *port;
	char designation;

	hsr = netdev_priv(dev);
	designation = '\0';

	rcu_read_lock();
	hsr_for_each_port(hsr, port) {
		if (port->type == HSR_PT_MASTER)
			continue;
		switch (port->type) {
		case HSR_PT_SLAVE_A:
			designation = 'A';
			break;
		case HSR_PT_SLAVE_B:
			designation = 'B';
			break;
		default:
			designation = '?';
		}
		if (!is_slave_up(port->dev))
			netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",
				    designation, port->dev->name);
	}
	rcu_read_unlock();

	if (designation == '\0')
		netdev_warn(dev, "No slave devices configured\n");

	return 0;
}


static int hsr_dev_close(struct net_device *dev)
{
	/* Nothing to do here. */
	return 0;
}


static void hsr_fill_tag(struct hsr_ethhdr *hsr_ethhdr, struct hsr_priv *hsr)
{
	unsigned long irqflags;

	/* IEC 62439-1:2010, p 48, says the 4-bit "path" field can take values
	 * between 0001-1001 ("ring identifier", for regular HSR frames),
	 * or 1111 ("HSR management", supervision frames). Unfortunately, the
	 * spec writers forgot to explain what a "ring identifier" is, or
	 * how it is used. So we just set this to 0001 for regular frames,
	 * and 1111 for supervision frames.
	 */
	set_hsr_tag_path(&hsr_ethhdr->hsr_tag, 0x1);

	/* IEC 62439-1:2010, p 12: "The link service data unit in an Ethernet
	 * frame is the content of the frame located between the Length/Type
	 * field and the Frame Check Sequence."
	 *
	 * IEC 62439-3, p 48, specifies the "original LPDU" to include the
	 * original "LT" field (what "LT" means is not explained anywhere as
	 * far as I can see - perhaps "Length/Type"?). So LSDU_size might
	 * equal original length + 2.
	 *   Also, the fact that this field is not used anywhere (might be used
	 * by a RedBox connecting HSR and PRP nets?) means I cannot test its
	 * correctness. Instead of guessing, I set this to 0 here, to make any
	 * problems immediately apparent. Anyone using this driver with PRP/HSR
	 * RedBoxes might need to fix this...
	 */
	set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, 0);

	spin_lock_irqsave(&hsr->seqnr_lock, irqflags);
	hsr_ethhdr->hsr_tag.sequence_nr = htons(hsr->sequence_nr);
	hsr->sequence_nr++;
	spin_unlock_irqrestore(&hsr->seqnr_lock, irqflags);

	hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;

	hsr_ethhdr->ethhdr.h_proto = htons(ETH_P_PRP);
}

static int slave_xmit(struct hsr_priv *hsr, struct sk_buff *skb,
		      enum hsr_port_type type)
{
	struct hsr_port *port;
	struct hsr_ethhdr *hsr_ethhdr;

	hsr_ethhdr = (struct hsr_ethhdr *) skb->data;

	rcu_read_lock();
	port = hsr_port_get_hsr(hsr, type);
	if (!port) {
		rcu_read_unlock();
		return NET_XMIT_DROP;
	}
	skb->dev = port->dev;

	hsr_addr_subst_dest(port->hsr, &hsr_ethhdr->ethhdr, port);
	rcu_read_unlock();

	/* Address substitution (IEC62439-3 pp 26, 50): replace mac
	 * address of outgoing frame with that of the outgoing slave's.
	 */
	ether_addr_copy(hsr_ethhdr->ethhdr.h_source, skb->dev->dev_addr);

	return dev_queue_xmit(skb);
}

static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct hsr_priv *hsr;
	struct hsr_port *master;
	struct hsr_ethhdr *hsr_ethhdr;
	struct sk_buff *skb2;
	int res1, res2;

	hsr = netdev_priv(dev);
	hsr_ethhdr = (struct hsr_ethhdr *) skb->data;

	if ((skb->protocol != htons(ETH_P_PRP)) ||
	    (hsr_ethhdr->ethhdr.h_proto != htons(ETH_P_PRP))) {
		hsr_fill_tag(hsr_ethhdr, hsr);
		skb->protocol = htons(ETH_P_PRP);
	}

	skb2 = pskb_copy(skb, GFP_ATOMIC);

	res1 = slave_xmit(hsr, skb, HSR_PT_SLAVE_A);
	if (skb2)
		res2 = slave_xmit(hsr, skb2, HSR_PT_SLAVE_B);
	else
		res2 = NET_XMIT_DROP;

	rcu_read_lock();
	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
	if (likely(res1 == NET_XMIT_SUCCESS || res1 == NET_XMIT_CN ||
		   res2 == NET_XMIT_SUCCESS || res2 == NET_XMIT_CN)) {
		master->dev->stats.tx_packets++;
		master->dev->stats.tx_bytes += skb->len;
	} else {
		master->dev->stats.tx_dropped++;
	}
	rcu_read_unlock();

	return NETDEV_TX_OK;
}


static int hsr_header_create(struct sk_buff *skb, struct net_device *dev,
			     unsigned short type, const void *daddr,
			     const void *saddr, unsigned int len)
{
	int res;

	/* Make room for the HSR tag now. We will fill it in later (in
	 * hsr_dev_xmit)
	 */
	if (skb_headroom(skb) < HSR_HLEN + ETH_HLEN)
		return -ENOBUFS;
	skb_push(skb, HSR_HLEN);

	/* To allow VLAN/HSR combos we should probably use
	 * res = dev_hard_header(skb, dev, type, daddr, saddr, len + HSR_HLEN);
	 * here instead. It would require other changes too, though - e.g.
	 * separate headers for each slave etc...
	 */
	res = eth_header(skb, dev, type, daddr, saddr, len + HSR_HLEN);
	if (res <= 0)
		return res;
	skb_reset_mac_header(skb);

	return res + HSR_HLEN;
}


static const struct header_ops hsr_header_ops = {
	.create	 = hsr_header_create,
	.parse	 = eth_header_parse,
};


/* HSR:2010 supervision frames should be padded so that the whole frame,
 * including headers and FCS, is 64 bytes (without VLAN).
 */
static int hsr_pad(int size)
{
	const int min_size = ETH_ZLEN - HSR_HLEN - ETH_HLEN;

	if (size >= min_size)
		return size;
	return min_size;
}

static void send_hsr_supervision_frame(struct net_device *hsr_dev, u8 type)
{
	struct hsr_priv *hsr;
	struct hsr_port *master;
	struct sk_buff *skb;
	int hlen, tlen;
	struct hsr_sup_tag *hsr_stag;
	struct hsr_sup_payload *hsr_sp;
	unsigned long irqflags;
	int res;

	hsr = netdev_priv(hsr_dev);
	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);

	hlen = LL_RESERVED_SPACE(master->dev);
	tlen = master->dev->needed_tailroom;
	skb = alloc_skb(hsr_pad(sizeof(struct hsr_sup_payload)) + hlen + tlen,
			GFP_ATOMIC);

	if (skb == NULL)
		return;

	skb_reserve(skb, hlen);

	skb->dev = master->dev;
	skb->protocol = htons(ETH_P_PRP);
	skb->priority = TC_PRIO_CONTROL;

	res = dev_hard_header(skb, skb->dev, ETH_P_PRP,
			      hsr->sup_multicast_addr,
			      skb->dev->dev_addr, skb->len);
	if (res <= 0)
		goto out;

	skb_pull(skb, sizeof(struct ethhdr));
	hsr_stag = (typeof(hsr_stag)) skb->data;

	set_hsr_stag_path(hsr_stag, 0xf);
	set_hsr_stag_HSR_Ver(hsr_stag, 0);

	spin_lock_irqsave(&hsr->seqnr_lock, irqflags);
	hsr_stag->sequence_nr = htons(hsr->sequence_nr);
	hsr->sequence_nr++;
	spin_unlock_irqrestore(&hsr->seqnr_lock, irqflags);

	hsr_stag->HSR_TLV_Type = type;
	hsr_stag->HSR_TLV_Length = 12;

	skb_push(skb, sizeof(struct ethhdr));

	/* Payload: MacAddressA */
	hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(*hsr_sp));
	ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);

	dev_queue_xmit(skb);
	return;

out:
	WARN_ON_ONCE("HSR: Could not send supervision frame\n");
	kfree_skb(skb);
}


/* Announce (supervision frame) timer function
 */
static void hsr_announce(unsigned long data)
{
	struct hsr_priv *hsr;
	struct hsr_port *master;

	hsr = (struct hsr_priv *) data;
	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);

	if (hsr->announce_count < 3) {
		send_hsr_supervision_frame(master->dev, HSR_TLV_ANNOUNCE);
		hsr->announce_count++;
	} else {
		send_hsr_supervision_frame(master->dev, HSR_TLV_LIFE_CHECK);
	}

	if (hsr->announce_count < 3)
		hsr->announce_timer.expires = jiffies +
				msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
	else
		hsr->announce_timer.expires = jiffies +
				msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);

	if (is_admin_up(master->dev))
		add_timer(&hsr->announce_timer);
}


/* According to comments in the declaration of struct net_device, this function
 * is "Called from unregister, can be used to call free_netdev". Ok then...
 */
static void hsr_dev_destroy(struct net_device *hsr_dev)
{
	struct hsr_priv *hsr;
	struct hsr_port *port;

	hsr = netdev_priv(hsr_dev);
	hsr_for_each_port(hsr, port)
		hsr_del_port(port);

	del_timer_sync(&hsr->prune_timer);
	del_timer_sync(&hsr->announce_timer);

	synchronize_rcu();
	free_netdev(hsr_dev);
}

static const struct net_device_ops hsr_device_ops = {
	.ndo_change_mtu = hsr_dev_change_mtu,
	.ndo_open = hsr_dev_open,
	.ndo_stop = hsr_dev_close,
	.ndo_start_xmit = hsr_dev_xmit,
};


void hsr_dev_setup(struct net_device *dev)
{
	random_ether_addr(dev->dev_addr);

	ether_setup(dev);
	dev->header_ops		 = &hsr_header_ops;
	dev->netdev_ops		 = &hsr_device_ops;
	dev->tx_queue_len	 = 0;

	dev->destructor = hsr_dev_destroy;
}


/* Return true if dev is a HSR master; return false otherwise.
 */
inline bool is_hsr_master(struct net_device *dev)
{
	return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
}

/* Default multicast address for HSR Supervision frames */
static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
	0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
};

int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
		     unsigned char multicast_spec)
{
	struct hsr_priv *hsr;
	struct hsr_port *port;
	int res;

	hsr = netdev_priv(hsr_dev);
	INIT_LIST_HEAD(&hsr->ports);
	INIT_LIST_HEAD(&hsr->node_db);
	INIT_LIST_HEAD(&hsr->self_node_db);

	ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);

	/* Make sure we recognize frames from ourselves in hsr_rcv() */
	res = hsr_create_self_node(&hsr->self_node_db, hsr_dev->dev_addr,
				   slave[1]->dev_addr);
	if (res < 0)
		return res;

	hsr_dev->features = slave[0]->features & slave[1]->features;
	/* Prevent recursive tx locking */
	hsr_dev->features |= NETIF_F_LLTX;
	/* VLAN on top of HSR needs testing and probably some work on
	 * hsr_header_create() etc.
	 */
	hsr_dev->features |= NETIF_F_VLAN_CHALLENGED;

	spin_lock_init(&hsr->seqnr_lock);
	/* Overflow soon to find bugs easier: */
	hsr->sequence_nr = USHRT_MAX - 1024;

	init_timer(&hsr->announce_timer);
	hsr->announce_timer.function = hsr_announce;
	hsr->announce_timer.data = (unsigned long) hsr;

	init_timer(&hsr->prune_timer);
	hsr->prune_timer.function = hsr_prune_nodes;
	hsr->prune_timer.data = (unsigned long) hsr;

	ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
	hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;

	/* FIXME: should I modify the value of these?
	 *
	 * - hsr_dev->flags - i.e.
	 *			IFF_MASTER/SLAVE?
	 * - hsr_dev->priv_flags - i.e.
	 *			IFF_EBRIDGE?
	 *			IFF_TX_SKB_SHARING?
	 *			IFF_HSR_MASTER/SLAVE?
	 */

	/* Make sure the 1st call to netif_carrier_on() gets through */
	netif_carrier_off(hsr_dev);

	res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER);
	if (res)
		return res;

	res = register_netdevice(hsr_dev);
	if (res)
		goto fail;

	res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
	if (res)
		goto fail;
	res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
	if (res)
		goto fail;

	hsr->prune_timer.expires = jiffies + msecs_to_jiffies(PRUNE_PERIOD);
	add_timer(&hsr->prune_timer);

	return 0;

fail:
	hsr_for_each_port(hsr, port)
		hsr_del_port(port);

	return res;
}