xref: /linux/net/hsr/hsr_device.c (revision 37744feebc086908fd89760650f458ab19071750)
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 
61 	ASSERT_RTNL();
62 
63 	hsr_for_each_port(master->hsr, port) {
64 		if (port->type != HSR_PT_MASTER && is_slave_up(port->dev)) {
65 			netif_carrier_on(master->dev);
66 			return true;
67 		}
68 	}
69 
70 	netif_carrier_off(master->dev);
71 
72 	return false;
73 }
74 
75 static void hsr_check_announce(struct net_device *hsr_dev,
76 			       unsigned char old_operstate)
77 {
78 	struct hsr_priv *hsr;
79 
80 	hsr = netdev_priv(hsr_dev);
81 
82 	if (hsr_dev->operstate == IF_OPER_UP && old_operstate != IF_OPER_UP) {
83 		/* Went up */
84 		hsr->announce_count = 0;
85 		mod_timer(&hsr->announce_timer,
86 			  jiffies + msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL));
87 	}
88 
89 	if (hsr_dev->operstate != IF_OPER_UP && old_operstate == IF_OPER_UP)
90 		/* Went down */
91 		del_timer(&hsr->announce_timer);
92 }
93 
94 void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
95 {
96 	struct hsr_port *master;
97 	unsigned char old_operstate;
98 	bool has_carrier;
99 
100 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
101 	/* netif_stacked_transfer_operstate() cannot be used here since
102 	 * it doesn't set IF_OPER_LOWERLAYERDOWN (?)
103 	 */
104 	old_operstate = master->dev->operstate;
105 	has_carrier = hsr_check_carrier(master);
106 	hsr_set_operstate(master, has_carrier);
107 	hsr_check_announce(master->dev, old_operstate);
108 }
109 
110 int hsr_get_max_mtu(struct hsr_priv *hsr)
111 {
112 	unsigned int mtu_max;
113 	struct hsr_port *port;
114 
115 	mtu_max = ETH_DATA_LEN;
116 	hsr_for_each_port(hsr, port)
117 		if (port->type != HSR_PT_MASTER)
118 			mtu_max = min(port->dev->mtu, mtu_max);
119 
120 	if (mtu_max < HSR_HLEN)
121 		return 0;
122 	return mtu_max - HSR_HLEN;
123 }
124 
125 static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
126 {
127 	struct hsr_priv *hsr;
128 	struct hsr_port *master;
129 
130 	hsr = netdev_priv(dev);
131 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
132 
133 	if (new_mtu > hsr_get_max_mtu(hsr)) {
134 		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",
135 			    HSR_HLEN);
136 		return -EINVAL;
137 	}
138 
139 	dev->mtu = new_mtu;
140 
141 	return 0;
142 }
143 
144 static int hsr_dev_open(struct net_device *dev)
145 {
146 	struct hsr_priv *hsr;
147 	struct hsr_port *port;
148 	char designation;
149 
150 	hsr = netdev_priv(dev);
151 	designation = '\0';
152 
153 	hsr_for_each_port(hsr, port) {
154 		if (port->type == HSR_PT_MASTER)
155 			continue;
156 		switch (port->type) {
157 		case HSR_PT_SLAVE_A:
158 			designation = 'A';
159 			break;
160 		case HSR_PT_SLAVE_B:
161 			designation = 'B';
162 			break;
163 		default:
164 			designation = '?';
165 		}
166 		if (!is_slave_up(port->dev))
167 			netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",
168 				    designation, port->dev->name);
169 	}
170 
171 	if (designation == '\0')
172 		netdev_warn(dev, "No slave devices configured\n");
173 
174 	return 0;
175 }
176 
177 static int hsr_dev_close(struct net_device *dev)
178 {
179 	/* Nothing to do here. */
180 	return 0;
181 }
182 
183 static netdev_features_t hsr_features_recompute(struct hsr_priv *hsr,
184 						netdev_features_t features)
185 {
186 	netdev_features_t mask;
187 	struct hsr_port *port;
188 
189 	mask = features;
190 
191 	/* Mask out all features that, if supported by one device, should be
192 	 * enabled for all devices (see NETIF_F_ONE_FOR_ALL).
193 	 *
194 	 * Anything that's off in mask will not be enabled - so only things
195 	 * that were in features originally, and also is in NETIF_F_ONE_FOR_ALL,
196 	 * may become enabled.
197 	 */
198 	features &= ~NETIF_F_ONE_FOR_ALL;
199 	hsr_for_each_port(hsr, port)
200 		features = netdev_increment_features(features,
201 						     port->dev->features,
202 						     mask);
203 
204 	return features;
205 }
206 
207 static netdev_features_t hsr_fix_features(struct net_device *dev,
208 					  netdev_features_t features)
209 {
210 	struct hsr_priv *hsr = netdev_priv(dev);
211 
212 	return hsr_features_recompute(hsr, features);
213 }
214 
215 static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
216 {
217 	struct hsr_priv *hsr = netdev_priv(dev);
218 	struct hsr_port *master;
219 
220 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
221 	if (master) {
222 		skb->dev = master->dev;
223 		hsr_forward_skb(skb, master);
224 	} else {
225 		atomic_long_inc(&dev->tx_dropped);
226 		dev_kfree_skb_any(skb);
227 	}
228 	return NETDEV_TX_OK;
229 }
230 
231 static const struct header_ops hsr_header_ops = {
232 	.create	 = eth_header,
233 	.parse	 = eth_header_parse,
234 };
235 
236 static void send_hsr_supervision_frame(struct hsr_port *master,
237 				       u8 type, u8 hsr_ver)
238 {
239 	struct sk_buff *skb;
240 	int hlen, tlen;
241 	struct hsr_tag *hsr_tag;
242 	struct hsr_sup_tag *hsr_stag;
243 	struct hsr_sup_payload *hsr_sp;
244 	unsigned long irqflags;
245 
246 	hlen = LL_RESERVED_SPACE(master->dev);
247 	tlen = master->dev->needed_tailroom;
248 	skb = dev_alloc_skb(sizeof(struct hsr_tag) +
249 			    sizeof(struct hsr_sup_tag) +
250 			    sizeof(struct hsr_sup_payload) + hlen + tlen);
251 
252 	if (!skb)
253 		return;
254 
255 	skb_reserve(skb, hlen);
256 
257 	skb->dev = master->dev;
258 	skb->protocol = htons(hsr_ver ? ETH_P_HSR : ETH_P_PRP);
259 	skb->priority = TC_PRIO_CONTROL;
260 
261 	if (dev_hard_header(skb, skb->dev, (hsr_ver ? ETH_P_HSR : ETH_P_PRP),
262 			    master->hsr->sup_multicast_addr,
263 			    skb->dev->dev_addr, skb->len) <= 0)
264 		goto out;
265 	skb_reset_mac_header(skb);
266 	skb_reset_network_header(skb);
267 	skb_reset_transport_header(skb);
268 
269 	if (hsr_ver > 0) {
270 		hsr_tag = skb_put(skb, sizeof(struct hsr_tag));
271 		hsr_tag->encap_proto = htons(ETH_P_PRP);
272 		set_hsr_tag_LSDU_size(hsr_tag, HSR_V1_SUP_LSDUSIZE);
273 	}
274 
275 	hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
276 	set_hsr_stag_path(hsr_stag, (hsr_ver ? 0x0 : 0xf));
277 	set_hsr_stag_HSR_ver(hsr_stag, hsr_ver);
278 
279 	/* From HSRv1 on we have separate supervision sequence numbers. */
280 	spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
281 	if (hsr_ver > 0) {
282 		hsr_stag->sequence_nr = htons(master->hsr->sup_sequence_nr);
283 		hsr_tag->sequence_nr = htons(master->hsr->sequence_nr);
284 		master->hsr->sup_sequence_nr++;
285 		master->hsr->sequence_nr++;
286 	} else {
287 		hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
288 		master->hsr->sequence_nr++;
289 	}
290 	spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
291 
292 	hsr_stag->HSR_TLV_type = type;
293 	/* TODO: Why 12 in HSRv0? */
294 	hsr_stag->HSR_TLV_length =
295 				hsr_ver ? sizeof(struct hsr_sup_payload) : 12;
296 
297 	/* Payload: MacAddressA */
298 	hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
299 	ether_addr_copy(hsr_sp->macaddress_A, master->dev->dev_addr);
300 
301 	if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
302 		return;
303 
304 	hsr_forward_skb(skb, master);
305 	return;
306 
307 out:
308 	WARN_ONCE(1, "HSR: Could not send supervision frame\n");
309 	kfree_skb(skb);
310 }
311 
312 /* Announce (supervision frame) timer function
313  */
314 static void hsr_announce(struct timer_list *t)
315 {
316 	struct hsr_priv *hsr;
317 	struct hsr_port *master;
318 	unsigned long interval;
319 
320 	hsr = from_timer(hsr, t, announce_timer);
321 
322 	rcu_read_lock();
323 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
324 
325 	if (hsr->announce_count < 3 && hsr->prot_version == 0) {
326 		send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE,
327 					   hsr->prot_version);
328 		hsr->announce_count++;
329 
330 		interval = msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
331 	} else {
332 		send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK,
333 					   hsr->prot_version);
334 
335 		interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
336 	}
337 
338 	if (is_admin_up(master->dev))
339 		mod_timer(&hsr->announce_timer, jiffies + interval);
340 
341 	rcu_read_unlock();
342 }
343 
344 static void hsr_del_ports(struct hsr_priv *hsr)
345 {
346 	struct hsr_port *port;
347 
348 	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
349 	if (port)
350 		hsr_del_port(port);
351 
352 	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
353 	if (port)
354 		hsr_del_port(port);
355 
356 	port = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
357 	if (port)
358 		hsr_del_port(port);
359 }
360 
361 /* This has to be called after all the readers are gone.
362  * Otherwise we would have to check the return value of
363  * hsr_port_get_hsr().
364  */
365 static void hsr_dev_destroy(struct net_device *hsr_dev)
366 {
367 	struct hsr_priv *hsr = netdev_priv(hsr_dev);
368 
369 	hsr_debugfs_term(hsr);
370 	hsr_del_ports(hsr);
371 
372 	del_timer_sync(&hsr->prune_timer);
373 	del_timer_sync(&hsr->announce_timer);
374 
375 	hsr_del_self_node(hsr);
376 	hsr_del_nodes(&hsr->node_db);
377 }
378 
379 static const struct net_device_ops hsr_device_ops = {
380 	.ndo_change_mtu = hsr_dev_change_mtu,
381 	.ndo_open = hsr_dev_open,
382 	.ndo_stop = hsr_dev_close,
383 	.ndo_start_xmit = hsr_dev_xmit,
384 	.ndo_fix_features = hsr_fix_features,
385 	.ndo_uninit = hsr_dev_destroy,
386 };
387 
388 static struct device_type hsr_type = {
389 	.name = "hsr",
390 };
391 
392 void hsr_dev_setup(struct net_device *dev)
393 {
394 	eth_hw_addr_random(dev);
395 
396 	ether_setup(dev);
397 	dev->min_mtu = 0;
398 	dev->header_ops = &hsr_header_ops;
399 	dev->netdev_ops = &hsr_device_ops;
400 	SET_NETDEV_DEVTYPE(dev, &hsr_type);
401 	dev->priv_flags |= IFF_NO_QUEUE;
402 
403 	dev->needs_free_netdev = true;
404 
405 	dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
406 			   NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
407 			   NETIF_F_HW_VLAN_CTAG_TX;
408 
409 	dev->features = dev->hw_features;
410 
411 	/* Prevent recursive tx locking */
412 	dev->features |= NETIF_F_LLTX;
413 	/* VLAN on top of HSR needs testing and probably some work on
414 	 * hsr_header_create() etc.
415 	 */
416 	dev->features |= NETIF_F_VLAN_CHALLENGED;
417 	/* Not sure about this. Taken from bridge code. netdev_features.h says
418 	 * it means "Does not change network namespaces".
419 	 */
420 	dev->features |= NETIF_F_NETNS_LOCAL;
421 }
422 
423 /* Return true if dev is a HSR master; return false otherwise.
424  */
425 inline bool is_hsr_master(struct net_device *dev)
426 {
427 	return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
428 }
429 
430 /* Default multicast address for HSR Supervision frames */
431 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
432 	0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
433 };
434 
435 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
436 		     unsigned char multicast_spec, u8 protocol_version,
437 		     struct netlink_ext_ack *extack)
438 {
439 	struct hsr_priv *hsr;
440 	int res;
441 
442 	hsr = netdev_priv(hsr_dev);
443 	INIT_LIST_HEAD(&hsr->ports);
444 	INIT_LIST_HEAD(&hsr->node_db);
445 	INIT_LIST_HEAD(&hsr->self_node_db);
446 	spin_lock_init(&hsr->list_lock);
447 
448 	ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
449 
450 	/* Make sure we recognize frames from ourselves in hsr_rcv() */
451 	res = hsr_create_self_node(hsr, hsr_dev->dev_addr,
452 				   slave[1]->dev_addr);
453 	if (res < 0)
454 		return res;
455 
456 	spin_lock_init(&hsr->seqnr_lock);
457 	/* Overflow soon to find bugs easier: */
458 	hsr->sequence_nr = HSR_SEQNR_START;
459 	hsr->sup_sequence_nr = HSR_SUP_SEQNR_START;
460 
461 	timer_setup(&hsr->announce_timer, hsr_announce, 0);
462 	timer_setup(&hsr->prune_timer, hsr_prune_nodes, 0);
463 
464 	ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
465 	hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
466 
467 	hsr->prot_version = protocol_version;
468 
469 	/* FIXME: should I modify the value of these?
470 	 *
471 	 * - hsr_dev->flags - i.e.
472 	 *			IFF_MASTER/SLAVE?
473 	 * - hsr_dev->priv_flags - i.e.
474 	 *			IFF_EBRIDGE?
475 	 *			IFF_TX_SKB_SHARING?
476 	 *			IFF_HSR_MASTER/SLAVE?
477 	 */
478 
479 	/* Make sure the 1st call to netif_carrier_on() gets through */
480 	netif_carrier_off(hsr_dev);
481 
482 	res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER, extack);
483 	if (res)
484 		goto err_add_master;
485 
486 	res = register_netdevice(hsr_dev);
487 	if (res)
488 		goto err_unregister;
489 
490 	res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A, extack);
491 	if (res)
492 		goto err_add_slaves;
493 
494 	res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B, extack);
495 	if (res)
496 		goto err_add_slaves;
497 
498 	hsr_debugfs_init(hsr, hsr_dev);
499 	mod_timer(&hsr->prune_timer, jiffies + msecs_to_jiffies(PRUNE_PERIOD));
500 
501 	return 0;
502 
503 err_add_slaves:
504 	unregister_netdevice(hsr_dev);
505 err_unregister:
506 	hsr_del_ports(hsr);
507 err_add_master:
508 	hsr_del_self_node(hsr);
509 
510 	return res;
511 }
512