xref: /linux/net/hsr/hsr_device.c (revision f79e4d5f92a129a1159c973735007d4ddc8541f3)
1 /* Copyright 2011-2014 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  *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
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/rtnetlink.h>
19 #include <linux/pkt_sched.h>
20 #include "hsr_device.h"
21 #include "hsr_slave.h"
22 #include "hsr_framereg.h"
23 #include "hsr_main.h"
24 #include "hsr_forward.h"
25 
26 
27 static bool is_admin_up(struct net_device *dev)
28 {
29 	return dev && (dev->flags & IFF_UP);
30 }
31 
32 static bool is_slave_up(struct net_device *dev)
33 {
34 	return dev && is_admin_up(dev) && netif_oper_up(dev);
35 }
36 
37 static void __hsr_set_operstate(struct net_device *dev, int transition)
38 {
39 	write_lock_bh(&dev_base_lock);
40 	if (dev->operstate != transition) {
41 		dev->operstate = transition;
42 		write_unlock_bh(&dev_base_lock);
43 		netdev_state_change(dev);
44 	} else {
45 		write_unlock_bh(&dev_base_lock);
46 	}
47 }
48 
49 static void hsr_set_operstate(struct hsr_port *master, bool has_carrier)
50 {
51 	if (!is_admin_up(master->dev)) {
52 		__hsr_set_operstate(master->dev, IF_OPER_DOWN);
53 		return;
54 	}
55 
56 	if (has_carrier)
57 		__hsr_set_operstate(master->dev, IF_OPER_UP);
58 	else
59 		__hsr_set_operstate(master->dev, IF_OPER_LOWERLAYERDOWN);
60 }
61 
62 static bool hsr_check_carrier(struct hsr_port *master)
63 {
64 	struct hsr_port *port;
65 	bool has_carrier;
66 
67 	has_carrier = false;
68 
69 	rcu_read_lock();
70 	hsr_for_each_port(master->hsr, port)
71 		if ((port->type != HSR_PT_MASTER) && is_slave_up(port->dev)) {
72 			has_carrier = true;
73 			break;
74 		}
75 	rcu_read_unlock();
76 
77 	if (has_carrier)
78 		netif_carrier_on(master->dev);
79 	else
80 		netif_carrier_off(master->dev);
81 
82 	return has_carrier;
83 }
84 
85 
86 static void hsr_check_announce(struct net_device *hsr_dev,
87 			       unsigned char old_operstate)
88 {
89 	struct hsr_priv *hsr;
90 
91 	hsr = netdev_priv(hsr_dev);
92 
93 	if ((hsr_dev->operstate == IF_OPER_UP)
94 			&& (old_operstate != IF_OPER_UP)) {
95 		/* Went up */
96 		hsr->announce_count = 0;
97 		hsr->announce_timer.expires = jiffies +
98 				msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
99 		add_timer(&hsr->announce_timer);
100 	}
101 
102 	if ((hsr_dev->operstate != IF_OPER_UP) && (old_operstate == IF_OPER_UP))
103 		/* Went down */
104 		del_timer(&hsr->announce_timer);
105 }
106 
107 void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
108 {
109 	struct hsr_port *master;
110 	unsigned char old_operstate;
111 	bool has_carrier;
112 
113 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
114 	/* netif_stacked_transfer_operstate() cannot be used here since
115 	 * it doesn't set IF_OPER_LOWERLAYERDOWN (?)
116 	 */
117 	old_operstate = master->dev->operstate;
118 	has_carrier = hsr_check_carrier(master);
119 	hsr_set_operstate(master, has_carrier);
120 	hsr_check_announce(master->dev, old_operstate);
121 }
122 
123 int hsr_get_max_mtu(struct hsr_priv *hsr)
124 {
125 	unsigned int mtu_max;
126 	struct hsr_port *port;
127 
128 	mtu_max = ETH_DATA_LEN;
129 	rcu_read_lock();
130 	hsr_for_each_port(hsr, port)
131 		if (port->type != HSR_PT_MASTER)
132 			mtu_max = min(port->dev->mtu, mtu_max);
133 	rcu_read_unlock();
134 
135 	if (mtu_max < HSR_HLEN)
136 		return 0;
137 	return mtu_max - HSR_HLEN;
138 }
139 
140 
141 static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
142 {
143 	struct hsr_priv *hsr;
144 	struct hsr_port *master;
145 
146 	hsr = netdev_priv(dev);
147 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
148 
149 	if (new_mtu > hsr_get_max_mtu(hsr)) {
150 		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",
151 			    HSR_HLEN);
152 		return -EINVAL;
153 	}
154 
155 	dev->mtu = new_mtu;
156 
157 	return 0;
158 }
159 
160 static int hsr_dev_open(struct net_device *dev)
161 {
162 	struct hsr_priv *hsr;
163 	struct hsr_port *port;
164 	char designation;
165 
166 	hsr = netdev_priv(dev);
167 	designation = '\0';
168 
169 	rcu_read_lock();
170 	hsr_for_each_port(hsr, port) {
171 		if (port->type == HSR_PT_MASTER)
172 			continue;
173 		switch (port->type) {
174 		case HSR_PT_SLAVE_A:
175 			designation = 'A';
176 			break;
177 		case HSR_PT_SLAVE_B:
178 			designation = 'B';
179 			break;
180 		default:
181 			designation = '?';
182 		}
183 		if (!is_slave_up(port->dev))
184 			netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",
185 				    designation, port->dev->name);
186 	}
187 	rcu_read_unlock();
188 
189 	if (designation == '\0')
190 		netdev_warn(dev, "No slave devices configured\n");
191 
192 	return 0;
193 }
194 
195 
196 static int hsr_dev_close(struct net_device *dev)
197 {
198 	/* Nothing to do here. */
199 	return 0;
200 }
201 
202 
203 static netdev_features_t hsr_features_recompute(struct hsr_priv *hsr,
204 						netdev_features_t features)
205 {
206 	netdev_features_t mask;
207 	struct hsr_port *port;
208 
209 	mask = features;
210 
211 	/* Mask out all features that, if supported by one device, should be
212 	 * enabled for all devices (see NETIF_F_ONE_FOR_ALL).
213 	 *
214 	 * Anything that's off in mask will not be enabled - so only things
215 	 * that were in features originally, and also is in NETIF_F_ONE_FOR_ALL,
216 	 * may become enabled.
217 	 */
218 	features &= ~NETIF_F_ONE_FOR_ALL;
219 	hsr_for_each_port(hsr, port)
220 		features = netdev_increment_features(features,
221 						     port->dev->features,
222 						     mask);
223 
224 	return features;
225 }
226 
227 static netdev_features_t hsr_fix_features(struct net_device *dev,
228 					  netdev_features_t features)
229 {
230 	struct hsr_priv *hsr = netdev_priv(dev);
231 
232 	return hsr_features_recompute(hsr, features);
233 }
234 
235 
236 static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
237 {
238 	struct hsr_priv *hsr = netdev_priv(dev);
239 	struct hsr_port *master;
240 
241 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
242 	skb->dev = master->dev;
243 	hsr_forward_skb(skb, master);
244 
245 	return NETDEV_TX_OK;
246 }
247 
248 
249 static const struct header_ops hsr_header_ops = {
250 	.create	 = eth_header,
251 	.parse	 = eth_header_parse,
252 };
253 
254 static void send_hsr_supervision_frame(struct hsr_port *master,
255 		u8 type, u8 hsrVer)
256 {
257 	struct sk_buff *skb;
258 	int hlen, tlen;
259 	struct hsr_tag *hsr_tag;
260 	struct hsr_sup_tag *hsr_stag;
261 	struct hsr_sup_payload *hsr_sp;
262 	unsigned long irqflags;
263 
264 	hlen = LL_RESERVED_SPACE(master->dev);
265 	tlen = master->dev->needed_tailroom;
266 	skb = dev_alloc_skb(
267 			sizeof(struct hsr_tag) +
268 			sizeof(struct hsr_sup_tag) +
269 			sizeof(struct hsr_sup_payload) + hlen + tlen);
270 
271 	if (skb == NULL)
272 		return;
273 
274 	skb_reserve(skb, hlen);
275 
276 	skb->dev = master->dev;
277 	skb->protocol = htons(hsrVer ? ETH_P_HSR : ETH_P_PRP);
278 	skb->priority = TC_PRIO_CONTROL;
279 
280 	if (dev_hard_header(skb, skb->dev, (hsrVer ? ETH_P_HSR : ETH_P_PRP),
281 			    master->hsr->sup_multicast_addr,
282 			    skb->dev->dev_addr, skb->len) <= 0)
283 		goto out;
284 	skb_reset_mac_header(skb);
285 
286 	if (hsrVer > 0) {
287 		hsr_tag = skb_put(skb, sizeof(struct hsr_tag));
288 		hsr_tag->encap_proto = htons(ETH_P_PRP);
289 		set_hsr_tag_LSDU_size(hsr_tag, HSR_V1_SUP_LSDUSIZE);
290 	}
291 
292 	hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
293 	set_hsr_stag_path(hsr_stag, (hsrVer ? 0x0 : 0xf));
294 	set_hsr_stag_HSR_Ver(hsr_stag, hsrVer);
295 
296 	/* From HSRv1 on we have separate supervision sequence numbers. */
297 	spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
298 	if (hsrVer > 0) {
299 		hsr_stag->sequence_nr = htons(master->hsr->sup_sequence_nr);
300 		hsr_tag->sequence_nr = htons(master->hsr->sequence_nr);
301 		master->hsr->sup_sequence_nr++;
302 		master->hsr->sequence_nr++;
303 	} else {
304 		hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
305 		master->hsr->sequence_nr++;
306 	}
307 	spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
308 
309 	hsr_stag->HSR_TLV_Type = type;
310 	/* TODO: Why 12 in HSRv0? */
311 	hsr_stag->HSR_TLV_Length = hsrVer ? sizeof(struct hsr_sup_payload) : 12;
312 
313 	/* Payload: MacAddressA */
314 	hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
315 	ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);
316 
317 	if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
318 		return;
319 
320 	hsr_forward_skb(skb, master);
321 	return;
322 
323 out:
324 	WARN_ONCE(1, "HSR: Could not send supervision frame\n");
325 	kfree_skb(skb);
326 }
327 
328 
329 /* Announce (supervision frame) timer function
330  */
331 static void hsr_announce(struct timer_list *t)
332 {
333 	struct hsr_priv *hsr;
334 	struct hsr_port *master;
335 
336 	hsr = from_timer(hsr, t, announce_timer);
337 
338 	rcu_read_lock();
339 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
340 
341 	if (hsr->announce_count < 3 && hsr->protVersion == 0) {
342 		send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE,
343 				hsr->protVersion);
344 		hsr->announce_count++;
345 
346 		hsr->announce_timer.expires = jiffies +
347 				msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
348 	} else {
349 		send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK,
350 				hsr->protVersion);
351 
352 		hsr->announce_timer.expires = jiffies +
353 				msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
354 	}
355 
356 	if (is_admin_up(master->dev))
357 		add_timer(&hsr->announce_timer);
358 
359 	rcu_read_unlock();
360 }
361 
362 
363 /* According to comments in the declaration of struct net_device, this function
364  * is "Called from unregister, can be used to call free_netdev". Ok then...
365  */
366 static void hsr_dev_destroy(struct net_device *hsr_dev)
367 {
368 	struct hsr_priv *hsr;
369 	struct hsr_port *port;
370 
371 	hsr = netdev_priv(hsr_dev);
372 
373 	rtnl_lock();
374 	hsr_for_each_port(hsr, port)
375 		hsr_del_port(port);
376 	rtnl_unlock();
377 
378 	del_timer_sync(&hsr->prune_timer);
379 	del_timer_sync(&hsr->announce_timer);
380 
381 	synchronize_rcu();
382 }
383 
384 static const struct net_device_ops hsr_device_ops = {
385 	.ndo_change_mtu = hsr_dev_change_mtu,
386 	.ndo_open = hsr_dev_open,
387 	.ndo_stop = hsr_dev_close,
388 	.ndo_start_xmit = hsr_dev_xmit,
389 	.ndo_fix_features = hsr_fix_features,
390 };
391 
392 static struct device_type hsr_type = {
393 	.name = "hsr",
394 };
395 
396 void hsr_dev_setup(struct net_device *dev)
397 {
398 	eth_hw_addr_random(dev);
399 
400 	ether_setup(dev);
401 	dev->min_mtu = 0;
402 	dev->header_ops = &hsr_header_ops;
403 	dev->netdev_ops = &hsr_device_ops;
404 	SET_NETDEV_DEVTYPE(dev, &hsr_type);
405 	dev->priv_flags |= IFF_NO_QUEUE;
406 
407 	dev->needs_free_netdev = true;
408 	dev->priv_destructor = hsr_dev_destroy;
409 
410 	dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
411 			   NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
412 			   NETIF_F_HW_VLAN_CTAG_TX;
413 
414 	dev->features = dev->hw_features;
415 
416 	/* Prevent recursive tx locking */
417 	dev->features |= NETIF_F_LLTX;
418 	/* VLAN on top of HSR needs testing and probably some work on
419 	 * hsr_header_create() etc.
420 	 */
421 	dev->features |= NETIF_F_VLAN_CHALLENGED;
422 	/* Not sure about this. Taken from bridge code. netdev_features.h says
423 	 * it means "Does not change network namespaces".
424 	 */
425 	dev->features |= NETIF_F_NETNS_LOCAL;
426 }
427 
428 
429 /* Return true if dev is a HSR master; return false otherwise.
430  */
431 inline bool is_hsr_master(struct net_device *dev)
432 {
433 	return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
434 }
435 
436 /* Default multicast address for HSR Supervision frames */
437 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
438 	0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
439 };
440 
441 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
442 		     unsigned char multicast_spec, u8 protocol_version)
443 {
444 	struct hsr_priv *hsr;
445 	struct hsr_port *port;
446 	int res;
447 
448 	hsr = netdev_priv(hsr_dev);
449 	INIT_LIST_HEAD(&hsr->ports);
450 	INIT_LIST_HEAD(&hsr->node_db);
451 	INIT_LIST_HEAD(&hsr->self_node_db);
452 
453 	ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
454 
455 	/* Make sure we recognize frames from ourselves in hsr_rcv() */
456 	res = hsr_create_self_node(&hsr->self_node_db, hsr_dev->dev_addr,
457 				   slave[1]->dev_addr);
458 	if (res < 0)
459 		return res;
460 
461 	spin_lock_init(&hsr->seqnr_lock);
462 	/* Overflow soon to find bugs easier: */
463 	hsr->sequence_nr = HSR_SEQNR_START;
464 	hsr->sup_sequence_nr = HSR_SUP_SEQNR_START;
465 
466 	timer_setup(&hsr->announce_timer, hsr_announce, 0);
467 	timer_setup(&hsr->prune_timer, hsr_prune_nodes, 0);
468 
469 	ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
470 	hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
471 
472 	hsr->protVersion = protocol_version;
473 
474 	/* FIXME: should I modify the value of these?
475 	 *
476 	 * - hsr_dev->flags - i.e.
477 	 *			IFF_MASTER/SLAVE?
478 	 * - hsr_dev->priv_flags - i.e.
479 	 *			IFF_EBRIDGE?
480 	 *			IFF_TX_SKB_SHARING?
481 	 *			IFF_HSR_MASTER/SLAVE?
482 	 */
483 
484 	/* Make sure the 1st call to netif_carrier_on() gets through */
485 	netif_carrier_off(hsr_dev);
486 
487 	res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER);
488 	if (res)
489 		return res;
490 
491 	res = register_netdevice(hsr_dev);
492 	if (res)
493 		goto fail;
494 
495 	res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
496 	if (res)
497 		goto fail;
498 	res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
499 	if (res)
500 		goto fail;
501 
502 	mod_timer(&hsr->prune_timer, jiffies + msecs_to_jiffies(PRUNE_PERIOD));
503 
504 	return 0;
505 
506 fail:
507 	hsr_for_each_port(hsr, port)
508 		hsr_del_port(port);
509 
510 	return res;
511 }
512