xref: /openbmc/linux/net/hsr/hsr_device.c (revision be709d48)
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 		mod_timer(&hsr->announce_timer,
98 			  jiffies + msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL));
99 	}
100 
101 	if ((hsr_dev->operstate != IF_OPER_UP) && (old_operstate == IF_OPER_UP))
102 		/* Went down */
103 		del_timer(&hsr->announce_timer);
104 }
105 
106 void hsr_check_carrier_and_operstate(struct hsr_priv *hsr)
107 {
108 	struct hsr_port *master;
109 	unsigned char old_operstate;
110 	bool has_carrier;
111 
112 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
113 	/* netif_stacked_transfer_operstate() cannot be used here since
114 	 * it doesn't set IF_OPER_LOWERLAYERDOWN (?)
115 	 */
116 	old_operstate = master->dev->operstate;
117 	has_carrier = hsr_check_carrier(master);
118 	hsr_set_operstate(master, has_carrier);
119 	hsr_check_announce(master->dev, old_operstate);
120 }
121 
122 int hsr_get_max_mtu(struct hsr_priv *hsr)
123 {
124 	unsigned int mtu_max;
125 	struct hsr_port *port;
126 
127 	mtu_max = ETH_DATA_LEN;
128 	rcu_read_lock();
129 	hsr_for_each_port(hsr, port)
130 		if (port->type != HSR_PT_MASTER)
131 			mtu_max = min(port->dev->mtu, mtu_max);
132 	rcu_read_unlock();
133 
134 	if (mtu_max < HSR_HLEN)
135 		return 0;
136 	return mtu_max - HSR_HLEN;
137 }
138 
139 
140 static int hsr_dev_change_mtu(struct net_device *dev, int new_mtu)
141 {
142 	struct hsr_priv *hsr;
143 	struct hsr_port *master;
144 
145 	hsr = netdev_priv(dev);
146 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
147 
148 	if (new_mtu > hsr_get_max_mtu(hsr)) {
149 		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",
150 			    HSR_HLEN);
151 		return -EINVAL;
152 	}
153 
154 	dev->mtu = new_mtu;
155 
156 	return 0;
157 }
158 
159 static int hsr_dev_open(struct net_device *dev)
160 {
161 	struct hsr_priv *hsr;
162 	struct hsr_port *port;
163 	char designation;
164 
165 	hsr = netdev_priv(dev);
166 	designation = '\0';
167 
168 	rcu_read_lock();
169 	hsr_for_each_port(hsr, port) {
170 		if (port->type == HSR_PT_MASTER)
171 			continue;
172 		switch (port->type) {
173 		case HSR_PT_SLAVE_A:
174 			designation = 'A';
175 			break;
176 		case HSR_PT_SLAVE_B:
177 			designation = 'B';
178 			break;
179 		default:
180 			designation = '?';
181 		}
182 		if (!is_slave_up(port->dev))
183 			netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",
184 				    designation, port->dev->name);
185 	}
186 	rcu_read_unlock();
187 
188 	if (designation == '\0')
189 		netdev_warn(dev, "No slave devices configured\n");
190 
191 	return 0;
192 }
193 
194 
195 static int hsr_dev_close(struct net_device *dev)
196 {
197 	/* Nothing to do here. */
198 	return 0;
199 }
200 
201 
202 static netdev_features_t hsr_features_recompute(struct hsr_priv *hsr,
203 						netdev_features_t features)
204 {
205 	netdev_features_t mask;
206 	struct hsr_port *port;
207 
208 	mask = features;
209 
210 	/* Mask out all features that, if supported by one device, should be
211 	 * enabled for all devices (see NETIF_F_ONE_FOR_ALL).
212 	 *
213 	 * Anything that's off in mask will not be enabled - so only things
214 	 * that were in features originally, and also is in NETIF_F_ONE_FOR_ALL,
215 	 * may become enabled.
216 	 */
217 	features &= ~NETIF_F_ONE_FOR_ALL;
218 	hsr_for_each_port(hsr, port)
219 		features = netdev_increment_features(features,
220 						     port->dev->features,
221 						     mask);
222 
223 	return features;
224 }
225 
226 static netdev_features_t hsr_fix_features(struct net_device *dev,
227 					  netdev_features_t features)
228 {
229 	struct hsr_priv *hsr = netdev_priv(dev);
230 
231 	return hsr_features_recompute(hsr, features);
232 }
233 
234 
235 static int hsr_dev_xmit(struct sk_buff *skb, struct net_device *dev)
236 {
237 	struct hsr_priv *hsr = netdev_priv(dev);
238 	struct hsr_port *master;
239 
240 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
241 	skb->dev = master->dev;
242 	hsr_forward_skb(skb, master);
243 
244 	return NETDEV_TX_OK;
245 }
246 
247 
248 static const struct header_ops hsr_header_ops = {
249 	.create	 = eth_header,
250 	.parse	 = eth_header_parse,
251 };
252 
253 static void send_hsr_supervision_frame(struct hsr_port *master,
254 		u8 type, u8 hsrVer)
255 {
256 	struct sk_buff *skb;
257 	int hlen, tlen;
258 	struct hsr_tag *hsr_tag;
259 	struct hsr_sup_tag *hsr_stag;
260 	struct hsr_sup_payload *hsr_sp;
261 	unsigned long irqflags;
262 
263 	hlen = LL_RESERVED_SPACE(master->dev);
264 	tlen = master->dev->needed_tailroom;
265 	skb = dev_alloc_skb(
266 			sizeof(struct hsr_tag) +
267 			sizeof(struct hsr_sup_tag) +
268 			sizeof(struct hsr_sup_payload) + hlen + tlen);
269 
270 	if (skb == NULL)
271 		return;
272 
273 	skb_reserve(skb, hlen);
274 
275 	skb->dev = master->dev;
276 	skb->protocol = htons(hsrVer ? ETH_P_HSR : ETH_P_PRP);
277 	skb->priority = TC_PRIO_CONTROL;
278 
279 	if (dev_hard_header(skb, skb->dev, (hsrVer ? ETH_P_HSR : ETH_P_PRP),
280 			    master->hsr->sup_multicast_addr,
281 			    skb->dev->dev_addr, skb->len) <= 0)
282 		goto out;
283 	skb_reset_mac_header(skb);
284 
285 	if (hsrVer > 0) {
286 		hsr_tag = skb_put(skb, sizeof(struct hsr_tag));
287 		hsr_tag->encap_proto = htons(ETH_P_PRP);
288 		set_hsr_tag_LSDU_size(hsr_tag, HSR_V1_SUP_LSDUSIZE);
289 	}
290 
291 	hsr_stag = skb_put(skb, sizeof(struct hsr_sup_tag));
292 	set_hsr_stag_path(hsr_stag, (hsrVer ? 0x0 : 0xf));
293 	set_hsr_stag_HSR_Ver(hsr_stag, hsrVer);
294 
295 	/* From HSRv1 on we have separate supervision sequence numbers. */
296 	spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
297 	if (hsrVer > 0) {
298 		hsr_stag->sequence_nr = htons(master->hsr->sup_sequence_nr);
299 		hsr_tag->sequence_nr = htons(master->hsr->sequence_nr);
300 		master->hsr->sup_sequence_nr++;
301 		master->hsr->sequence_nr++;
302 	} else {
303 		hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
304 		master->hsr->sequence_nr++;
305 	}
306 	spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
307 
308 	hsr_stag->HSR_TLV_Type = type;
309 	/* TODO: Why 12 in HSRv0? */
310 	hsr_stag->HSR_TLV_Length = hsrVer ? sizeof(struct hsr_sup_payload) : 12;
311 
312 	/* Payload: MacAddressA */
313 	hsr_sp = skb_put(skb, sizeof(struct hsr_sup_payload));
314 	ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);
315 
316 	if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
317 		return;
318 
319 	hsr_forward_skb(skb, master);
320 	return;
321 
322 out:
323 	WARN_ONCE(1, "HSR: Could not send supervision frame\n");
324 	kfree_skb(skb);
325 }
326 
327 
328 /* Announce (supervision frame) timer function
329  */
330 static void hsr_announce(struct timer_list *t)
331 {
332 	struct hsr_priv *hsr;
333 	struct hsr_port *master;
334 	unsigned long interval;
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 		interval = msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
347 	} else {
348 		send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK,
349 				hsr->protVersion);
350 
351 		interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
352 	}
353 
354 	if (is_admin_up(master->dev))
355 		mod_timer(&hsr->announce_timer, jiffies + interval);
356 
357 	rcu_read_unlock();
358 }
359 
360 
361 /* According to comments in the declaration of struct net_device, this function
362  * is "Called from unregister, can be used to call free_netdev". Ok then...
363  */
364 static void hsr_dev_destroy(struct net_device *hsr_dev)
365 {
366 	struct hsr_priv *hsr;
367 	struct hsr_port *port;
368 
369 	hsr = netdev_priv(hsr_dev);
370 
371 	rtnl_lock();
372 	hsr_for_each_port(hsr, port)
373 		hsr_del_port(port);
374 	rtnl_unlock();
375 
376 	del_timer_sync(&hsr->prune_timer);
377 	del_timer_sync(&hsr->announce_timer);
378 
379 	synchronize_rcu();
380 }
381 
382 static const struct net_device_ops hsr_device_ops = {
383 	.ndo_change_mtu = hsr_dev_change_mtu,
384 	.ndo_open = hsr_dev_open,
385 	.ndo_stop = hsr_dev_close,
386 	.ndo_start_xmit = hsr_dev_xmit,
387 	.ndo_fix_features = hsr_fix_features,
388 };
389 
390 static struct device_type hsr_type = {
391 	.name = "hsr",
392 };
393 
394 void hsr_dev_setup(struct net_device *dev)
395 {
396 	eth_hw_addr_random(dev);
397 
398 	ether_setup(dev);
399 	dev->min_mtu = 0;
400 	dev->header_ops = &hsr_header_ops;
401 	dev->netdev_ops = &hsr_device_ops;
402 	SET_NETDEV_DEVTYPE(dev, &hsr_type);
403 	dev->priv_flags |= IFF_NO_QUEUE;
404 
405 	dev->needs_free_netdev = true;
406 	dev->priv_destructor = hsr_dev_destroy;
407 
408 	dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
409 			   NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
410 			   NETIF_F_HW_VLAN_CTAG_TX;
411 
412 	dev->features = dev->hw_features;
413 
414 	/* Prevent recursive tx locking */
415 	dev->features |= NETIF_F_LLTX;
416 	/* VLAN on top of HSR needs testing and probably some work on
417 	 * hsr_header_create() etc.
418 	 */
419 	dev->features |= NETIF_F_VLAN_CHALLENGED;
420 	/* Not sure about this. Taken from bridge code. netdev_features.h says
421 	 * it means "Does not change network namespaces".
422 	 */
423 	dev->features |= NETIF_F_NETNS_LOCAL;
424 }
425 
426 
427 /* Return true if dev is a HSR master; return false otherwise.
428  */
429 inline bool is_hsr_master(struct net_device *dev)
430 {
431 	return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
432 }
433 
434 /* Default multicast address for HSR Supervision frames */
435 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
436 	0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
437 };
438 
439 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
440 		     unsigned char multicast_spec, u8 protocol_version)
441 {
442 	struct hsr_priv *hsr;
443 	struct hsr_port *port;
444 	int res;
445 
446 	hsr = netdev_priv(hsr_dev);
447 	INIT_LIST_HEAD(&hsr->ports);
448 	INIT_LIST_HEAD(&hsr->node_db);
449 	INIT_LIST_HEAD(&hsr->self_node_db);
450 
451 	ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
452 
453 	/* Make sure we recognize frames from ourselves in hsr_rcv() */
454 	res = hsr_create_self_node(&hsr->self_node_db, hsr_dev->dev_addr,
455 				   slave[1]->dev_addr);
456 	if (res < 0)
457 		return res;
458 
459 	spin_lock_init(&hsr->seqnr_lock);
460 	/* Overflow soon to find bugs easier: */
461 	hsr->sequence_nr = HSR_SEQNR_START;
462 	hsr->sup_sequence_nr = HSR_SUP_SEQNR_START;
463 
464 	timer_setup(&hsr->announce_timer, hsr_announce, 0);
465 	timer_setup(&hsr->prune_timer, hsr_prune_nodes, 0);
466 
467 	ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
468 	hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
469 
470 	hsr->protVersion = protocol_version;
471 
472 	/* FIXME: should I modify the value of these?
473 	 *
474 	 * - hsr_dev->flags - i.e.
475 	 *			IFF_MASTER/SLAVE?
476 	 * - hsr_dev->priv_flags - i.e.
477 	 *			IFF_EBRIDGE?
478 	 *			IFF_TX_SKB_SHARING?
479 	 *			IFF_HSR_MASTER/SLAVE?
480 	 */
481 
482 	/* Make sure the 1st call to netif_carrier_on() gets through */
483 	netif_carrier_off(hsr_dev);
484 
485 	res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER);
486 	if (res)
487 		goto err_add_port;
488 
489 	res = register_netdevice(hsr_dev);
490 	if (res)
491 		goto fail;
492 
493 	res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
494 	if (res)
495 		goto fail;
496 	res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
497 	if (res)
498 		goto fail;
499 
500 	mod_timer(&hsr->prune_timer, jiffies + msecs_to_jiffies(PRUNE_PERIOD));
501 
502 	return 0;
503 
504 fail:
505 	hsr_for_each_port(hsr, port)
506 		hsr_del_port(port);
507 err_add_port:
508 	hsr_del_node(&hsr->self_node_db);
509 
510 	return res;
511 }
512