xref: /linux/net/hsr/hsr_device.c (revision f8e17c17b81070f38062dce79ca7f4541851dadd)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright 2011-2014 Autronica Fire and Security AS
3  *
4  * Author(s):
5  *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
6  *
7  * This file contains device methods for creating, using and destroying
8  * virtual HSR devices.
9  */
10 
11 #include <linux/netdevice.h>
12 #include <linux/skbuff.h>
13 #include <linux/etherdevice.h>
14 #include <linux/rtnetlink.h>
15 #include <linux/pkt_sched.h>
16 #include "hsr_device.h"
17 #include "hsr_slave.h"
18 #include "hsr_framereg.h"
19 #include "hsr_main.h"
20 #include "hsr_forward.h"
21 
22 static bool is_admin_up(struct net_device *dev)
23 {
24 	return dev && (dev->flags & IFF_UP);
25 }
26 
27 static bool is_slave_up(struct net_device *dev)
28 {
29 	return dev && is_admin_up(dev) && netif_oper_up(dev);
30 }
31 
32 static void __hsr_set_operstate(struct net_device *dev, int transition)
33 {
34 	write_lock_bh(&dev_base_lock);
35 	if (dev->operstate != transition) {
36 		dev->operstate = transition;
37 		write_unlock_bh(&dev_base_lock);
38 		netdev_state_change(dev);
39 	} else {
40 		write_unlock_bh(&dev_base_lock);
41 	}
42 }
43 
44 static void hsr_set_operstate(struct hsr_port *master, bool has_carrier)
45 {
46 	if (!is_admin_up(master->dev)) {
47 		__hsr_set_operstate(master->dev, IF_OPER_DOWN);
48 		return;
49 	}
50 
51 	if (has_carrier)
52 		__hsr_set_operstate(master->dev, IF_OPER_UP);
53 	else
54 		__hsr_set_operstate(master->dev, IF_OPER_LOWERLAYERDOWN);
55 }
56 
57 static bool hsr_check_carrier(struct hsr_port *master)
58 {
59 	struct hsr_port *port;
60 	bool has_carrier;
61 
62 	has_carrier = false;
63 
64 	rcu_read_lock();
65 	hsr_for_each_port(master->hsr, port)
66 		if (port->type != HSR_PT_MASTER && is_slave_up(port->dev)) {
67 			has_carrier = true;
68 			break;
69 		}
70 	rcu_read_unlock();
71 
72 	if (has_carrier)
73 		netif_carrier_on(master->dev);
74 	else
75 		netif_carrier_off(master->dev);
76 
77 	return has_carrier;
78 }
79 
80 static void hsr_check_announce(struct net_device *hsr_dev,
81 			       unsigned char old_operstate)
82 {
83 	struct hsr_priv *hsr;
84 
85 	hsr = netdev_priv(hsr_dev);
86 
87 	if (hsr_dev->operstate == IF_OPER_UP && old_operstate != IF_OPER_UP) {
88 		/* Went up */
89 		hsr->announce_count = 0;
90 		mod_timer(&hsr->announce_timer,
91 			  jiffies + msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL));
92 	}
93 
94 	if (hsr_dev->operstate != IF_OPER_UP && old_operstate == IF_OPER_UP)
95 		/* Went down */
96 		del_timer(&hsr->announce_timer);
97 }
98 
99 void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
100 {
101 	struct hsr_port *master;
102 	unsigned char old_operstate;
103 	bool has_carrier;
104 
105 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
106 	/* netif_stacked_transfer_operstate() cannot be used here since
107 	 * it doesn't set IF_OPER_LOWERLAYERDOWN (?)
108 	 */
109 	old_operstate = master->dev->operstate;
110 	has_carrier = hsr_check_carrier(master);
111 	hsr_set_operstate(master, has_carrier);
112 	hsr_check_announce(master->dev, old_operstate);
113 }
114 
115 int hsr_get_max_mtu(struct hsr_priv *hsr)
116 {
117 	unsigned int mtu_max;
118 	struct hsr_port *port;
119 
120 	mtu_max = ETH_DATA_LEN;
121 	rcu_read_lock();
122 	hsr_for_each_port(hsr, port)
123 		if (port->type != HSR_PT_MASTER)
124 			mtu_max = min(port->dev->mtu, mtu_max);
125 	rcu_read_unlock();
126 
127 	if (mtu_max < HSR_HLEN)
128 		return 0;
129 	return mtu_max - HSR_HLEN;
130 }
131 
132 static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
133 {
134 	struct hsr_priv *hsr;
135 	struct hsr_port *master;
136 
137 	hsr = netdev_priv(dev);
138 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
139 
140 	if (new_mtu > hsr_get_max_mtu(hsr)) {
141 		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",
142 			    HSR_HLEN);
143 		return -EINVAL;
144 	}
145 
146 	dev->mtu = new_mtu;
147 
148 	return 0;
149 }
150 
151 static int hsr_dev_open(struct net_device *dev)
152 {
153 	struct hsr_priv *hsr;
154 	struct hsr_port *port;
155 	char designation;
156 
157 	hsr = netdev_priv(dev);
158 	designation = '\0';
159 
160 	rcu_read_lock();
161 	hsr_for_each_port(hsr, port) {
162 		if (port->type == HSR_PT_MASTER)
163 			continue;
164 		switch (port->type) {
165 		case HSR_PT_SLAVE_A:
166 			designation = 'A';
167 			break;
168 		case HSR_PT_SLAVE_B:
169 			designation = 'B';
170 			break;
171 		default:
172 			designation = '?';
173 		}
174 		if (!is_slave_up(port->dev))
175 			netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",
176 				    designation, port->dev->name);
177 	}
178 	rcu_read_unlock();
179 
180 	if (designation == '\0')
181 		netdev_warn(dev, "No slave devices configured\n");
182 
183 	return 0;
184 }
185 
186 static int hsr_dev_close(struct net_device *dev)
187 {
188 	/* Nothing to do here. */
189 	return 0;
190 }
191 
192 static netdev_features_t hsr_features_recompute(struct hsr_priv *hsr,
193 						netdev_features_t features)
194 {
195 	netdev_features_t mask;
196 	struct hsr_port *port;
197 
198 	mask = features;
199 
200 	/* Mask out all features that, if supported by one device, should be
201 	 * enabled for all devices (see NETIF_F_ONE_FOR_ALL).
202 	 *
203 	 * Anything that's off in mask will not be enabled - so only things
204 	 * that were in features originally, and also is in NETIF_F_ONE_FOR_ALL,
205 	 * may become enabled.
206 	 */
207 	features &= ~NETIF_F_ONE_FOR_ALL;
208 	hsr_for_each_port(hsr, port)
209 		features = netdev_increment_features(features,
210 						     port->dev->features,
211 						     mask);
212 
213 	return features;
214 }
215 
216 static netdev_features_t hsr_fix_features(struct net_device *dev,
217 					  netdev_features_t features)
218 {
219 	struct hsr_priv *hsr = netdev_priv(dev);
220 
221 	return hsr_features_recompute(hsr, features);
222 }
223 
224 static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
225 {
226 	struct hsr_priv *hsr = netdev_priv(dev);
227 	struct hsr_port *master;
228 
229 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
230 	if (master) {
231 		skb->dev = master->dev;
232 		hsr_forward_skb(skb, master);
233 	} else {
234 		atomic_long_inc(&dev->tx_dropped);
235 		dev_kfree_skb_any(skb);
236 	}
237 	return NETDEV_TX_OK;
238 }
239 
240 static const struct header_ops hsr_header_ops = {
241 	.create	 = eth_header,
242 	.parse	 = eth_header_parse,
243 };
244 
245 static void send_hsr_supervision_frame(struct hsr_port *master,
246 				       u8 type, u8 hsr_ver)
247 {
248 	struct sk_buff *skb;
249 	int hlen, tlen;
250 	struct hsr_tag *hsr_tag;
251 	struct hsr_sup_tag *hsr_stag;
252 	struct hsr_sup_payload *hsr_sp;
253 	unsigned long irqflags;
254 
255 	hlen = LL_RESERVED_SPACE(master->dev);
256 	tlen = master->dev->needed_tailroom;
257 	skb = dev_alloc_skb(sizeof(struct hsr_tag) +
258 			    sizeof(struct hsr_sup_tag) +
259 			    sizeof(struct hsr_sup_payload) + hlen + tlen);
260 
261 	if (!skb)
262 		return;
263 
264 	skb_reserve(skb, hlen);
265 
266 	skb->dev = master->dev;
267 	skb->protocol = htons(hsr_ver ? ETH_P_HSR : ETH_P_PRP);
268 	skb->priority = TC_PRIO_CONTROL;
269 
270 	if (dev_hard_header(skb, skb->dev, (hsr_ver ? ETH_P_HSR : ETH_P_PRP),
271 			    master->hsr->sup_multicast_addr,
272 			    skb->dev->dev_addr, skb->len) <= 0)
273 		goto out;
274 	skb_reset_mac_header(skb);
275 	skb_reset_network_header(skb);
276 	skb_reset_transport_header(skb);
277 
278 	if (hsr_ver > 0) {
279 		hsr_tag = skb_put(skb, sizeof(struct hsr_tag));
280 		hsr_tag->encap_proto = htons(ETH_P_PRP);
281 		set_hsr_tag_LSDU_size(hsr_tag, HSR_V1_SUP_LSDUSIZE);
282 	}
283 
284 	hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
285 	set_hsr_stag_path(hsr_stag, (hsr_ver ? 0x0 : 0xf));
286 	set_hsr_stag_HSR_ver(hsr_stag, hsr_ver);
287 
288 	/* From HSRv1 on we have separate supervision sequence numbers. */
289 	spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
290 	if (hsr_ver > 0) {
291 		hsr_stag->sequence_nr = htons(master->hsr->sup_sequence_nr);
292 		hsr_tag->sequence_nr = htons(master->hsr->sequence_nr);
293 		master->hsr->sup_sequence_nr++;
294 		master->hsr->sequence_nr++;
295 	} else {
296 		hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
297 		master->hsr->sequence_nr++;
298 	}
299 	spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
300 
301 	hsr_stag->HSR_TLV_type = type;
302 	/* TODO: Why 12 in HSRv0? */
303 	hsr_stag->HSR_TLV_length =
304 				hsr_ver ? sizeof(struct hsr_sup_payload) : 12;
305 
306 	/* Payload: MacAddressA */
307 	hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
308 	ether_addr_copy(hsr_sp->macaddress_A, master->dev->dev_addr);
309 
310 	if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
311 		return;
312 
313 	hsr_forward_skb(skb, master);
314 	return;
315 
316 out:
317 	WARN_ONCE(1, "HSR: Could not send supervision frame\n");
318 	kfree_skb(skb);
319 }
320 
321 /* Announce (supervision frame) timer function
322  */
323 static void hsr_announce(struct timer_list *t)
324 {
325 	struct hsr_priv *hsr;
326 	struct hsr_port *master;
327 	unsigned long interval;
328 
329 	hsr = from_timer(hsr, t, announce_timer);
330 
331 	rcu_read_lock();
332 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
333 
334 	if (hsr->announce_count < 3 && hsr->prot_version == 0) {
335 		send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE,
336 					   hsr->prot_version);
337 		hsr->announce_count++;
338 
339 		interval = msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
340 	} else {
341 		send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK,
342 					   hsr->prot_version);
343 
344 		interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
345 	}
346 
347 	if (is_admin_up(master->dev))
348 		mod_timer(&hsr->announce_timer, jiffies + interval);
349 
350 	rcu_read_unlock();
351 }
352 
353 /* This has to be called after all the readers are gone.
354  * Otherwise we would have to check the return value of
355  * hsr_port_get_hsr().
356  */
357 static void hsr_dev_destroy(struct net_device *hsr_dev)
358 {
359 	struct hsr_priv *hsr;
360 	struct hsr_port *port;
361 	struct hsr_port *tmp;
362 
363 	hsr = netdev_priv(hsr_dev);
364 
365 	hsr_debugfs_term(hsr);
366 
367 	list_for_each_entry_safe(port, tmp, &hsr->ports, port_list)
368 		hsr_del_port(port);
369 
370 	del_timer_sync(&hsr->prune_timer);
371 	del_timer_sync(&hsr->announce_timer);
372 
373 	hsr_del_self_node(hsr);
374 	hsr_del_nodes(&hsr->node_db);
375 }
376 
377 static const struct net_device_ops hsr_device_ops = {
378 	.ndo_change_mtu = hsr_dev_change_mtu,
379 	.ndo_open = hsr_dev_open,
380 	.ndo_stop = hsr_dev_close,
381 	.ndo_start_xmit = hsr_dev_xmit,
382 	.ndo_fix_features = hsr_fix_features,
383 	.ndo_uninit = hsr_dev_destroy,
384 };
385 
386 static struct device_type hsr_type = {
387 	.name = "hsr",
388 };
389 
390 void hsr_dev_setup(struct net_device *dev)
391 {
392 	eth_hw_addr_random(dev);
393 
394 	ether_setup(dev);
395 	dev->min_mtu = 0;
396 	dev->header_ops = &hsr_header_ops;
397 	dev->netdev_ops = &hsr_device_ops;
398 	SET_NETDEV_DEVTYPE(dev, &hsr_type);
399 	dev->priv_flags |= IFF_NO_QUEUE;
400 
401 	dev->needs_free_netdev = true;
402 
403 	dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
404 			   NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
405 			   NETIF_F_HW_VLAN_CTAG_TX;
406 
407 	dev->features = dev->hw_features;
408 
409 	/* Prevent recursive tx locking */
410 	dev->features |= NETIF_F_LLTX;
411 	/* VLAN on top of HSR needs testing and probably some work on
412 	 * hsr_header_create() etc.
413 	 */
414 	dev->features |= NETIF_F_VLAN_CHALLENGED;
415 	/* Not sure about this. Taken from bridge code. netdev_features.h says
416 	 * it means "Does not change network namespaces".
417 	 */
418 	dev->features |= NETIF_F_NETNS_LOCAL;
419 }
420 
421 /* Return true if dev is a HSR master; return false otherwise.
422  */
423 inline bool is_hsr_master(struct net_device *dev)
424 {
425 	return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
426 }
427 
428 /* Default multicast address for HSR Supervision frames */
429 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
430 	0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
431 };
432 
433 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
434 		     unsigned char multicast_spec, u8 protocol_version)
435 {
436 	struct hsr_priv *hsr;
437 	struct hsr_port *port;
438 	struct hsr_port *tmp;
439 	int res;
440 
441 	hsr = netdev_priv(hsr_dev);
442 	INIT_LIST_HEAD(&hsr->ports);
443 	INIT_LIST_HEAD(&hsr->node_db);
444 	INIT_LIST_HEAD(&hsr->self_node_db);
445 	spin_lock_init(&hsr->list_lock);
446 
447 	ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
448 
449 	/* Make sure we recognize frames from ourselves in hsr_rcv() */
450 	res = hsr_create_self_node(hsr, hsr_dev->dev_addr,
451 				   slave[1]->dev_addr);
452 	if (res < 0)
453 		return res;
454 
455 	spin_lock_init(&hsr->seqnr_lock);
456 	/* Overflow soon to find bugs easier: */
457 	hsr->sequence_nr = HSR_SEQNR_START;
458 	hsr->sup_sequence_nr = HSR_SUP_SEQNR_START;
459 
460 	timer_setup(&hsr->announce_timer, hsr_announce, 0);
461 	timer_setup(&hsr->prune_timer, hsr_prune_nodes, 0);
462 
463 	ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
464 	hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
465 
466 	hsr->prot_version = protocol_version;
467 
468 	/* FIXME: should I modify the value of these?
469 	 *
470 	 * - hsr_dev->flags - i.e.
471 	 *			IFF_MASTER/SLAVE?
472 	 * - hsr_dev->priv_flags - i.e.
473 	 *			IFF_EBRIDGE?
474 	 *			IFF_TX_SKB_SHARING?
475 	 *			IFF_HSR_MASTER/SLAVE?
476 	 */
477 
478 	/* Make sure the 1st call to netif_carrier_on() gets through */
479 	netif_carrier_off(hsr_dev);
480 
481 	res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER);
482 	if (res)
483 		goto err_add_master;
484 
485 	res = register_netdevice(hsr_dev);
486 	if (res)
487 		goto err_unregister;
488 
489 	res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
490 	if (res)
491 		goto err_add_slaves;
492 
493 	res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
494 	if (res)
495 		goto err_add_slaves;
496 
497 	hsr_debugfs_init(hsr, hsr_dev);
498 	mod_timer(&hsr->prune_timer, jiffies + msecs_to_jiffies(PRUNE_PERIOD));
499 
500 	return 0;
501 
502 err_add_slaves:
503 	unregister_netdevice(hsr_dev);
504 err_unregister:
505 	list_for_each_entry_safe(port, tmp, &hsr->ports, port_list)
506 		hsr_del_port(port);
507 err_add_master:
508 	hsr_del_self_node(hsr);
509 
510 	return res;
511 }
512