xref: /linux/net/hsr/hsr_device.c (revision 8c749ce93ee69e789e46b3be98de9e0cbfcf8ed8)
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) && (old_operstate != IF_OPER_UP)) {
94 		/* Went up */
95 		hsr->announce_count = 0;
96 		hsr->announce_timer.expires = jiffies +
97 				msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
98 		add_timer(&hsr->announce_timer);
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 
254 /* HSR:2010 supervision frames should be padded so that the whole frame,
255  * including headers and FCS, is 64 bytes (without VLAN).
256  */
257 static int hsr_pad(int size)
258 {
259 	const int min_size = ETH_ZLEN - HSR_HLEN - ETH_HLEN;
260 
261 	if (size >= min_size)
262 		return size;
263 	return min_size;
264 }
265 
266 static void send_hsr_supervision_frame(struct hsr_port *master, u8 type)
267 {
268 	struct sk_buff *skb;
269 	int hlen, tlen;
270 	struct hsr_sup_tag *hsr_stag;
271 	struct hsr_sup_payload *hsr_sp;
272 	unsigned long irqflags;
273 
274 	hlen = LL_RESERVED_SPACE(master->dev);
275 	tlen = master->dev->needed_tailroom;
276 	skb = alloc_skb(hsr_pad(sizeof(struct hsr_sup_payload)) + hlen + tlen,
277 			GFP_ATOMIC);
278 
279 	if (skb == NULL)
280 		return;
281 
282 	skb_reserve(skb, hlen);
283 
284 	skb->dev = master->dev;
285 	skb->protocol = htons(ETH_P_PRP);
286 	skb->priority = TC_PRIO_CONTROL;
287 
288 	if (dev_hard_header(skb, skb->dev, ETH_P_PRP,
289 			    master->hsr->sup_multicast_addr,
290 			    skb->dev->dev_addr, skb->len) <= 0)
291 		goto out;
292 	skb_reset_mac_header(skb);
293 
294 	hsr_stag = (typeof(hsr_stag)) skb_put(skb, sizeof(*hsr_stag));
295 
296 	set_hsr_stag_path(hsr_stag, 0xf);
297 	set_hsr_stag_HSR_Ver(hsr_stag, 0);
298 
299 	spin_lock_irqsave(&master->hsr->seqnr_lock, irqflags);
300 	hsr_stag->sequence_nr = htons(master->hsr->sequence_nr);
301 	master->hsr->sequence_nr++;
302 	spin_unlock_irqrestore(&master->hsr->seqnr_lock, irqflags);
303 
304 	hsr_stag->HSR_TLV_Type = type;
305 	hsr_stag->HSR_TLV_Length = 12;
306 
307 	/* Payload: MacAddressA */
308 	hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(*hsr_sp));
309 	ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);
310 
311 	hsr_forward_skb(skb, master);
312 	return;
313 
314 out:
315 	WARN_ONCE(1, "HSR: Could not send supervision frame\n");
316 	kfree_skb(skb);
317 }
318 
319 
320 /* Announce (supervision frame) timer function
321  */
322 static void hsr_announce(unsigned long data)
323 {
324 	struct hsr_priv *hsr;
325 	struct hsr_port *master;
326 
327 	hsr = (struct hsr_priv *) data;
328 
329 	rcu_read_lock();
330 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
331 
332 	if (hsr->announce_count < 3) {
333 		send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE);
334 		hsr->announce_count++;
335 	} else {
336 		send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK);
337 	}
338 
339 	if (hsr->announce_count < 3)
340 		hsr->announce_timer.expires = jiffies +
341 				msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
342 	else
343 		hsr->announce_timer.expires = jiffies +
344 				msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
345 
346 	if (is_admin_up(master->dev))
347 		add_timer(&hsr->announce_timer);
348 
349 	rcu_read_unlock();
350 }
351 
352 
353 /* According to comments in the declaration of struct net_device, this function
354  * is "Called from unregister, can be used to call free_netdev". Ok then...
355  */
356 static void hsr_dev_destroy(struct net_device *hsr_dev)
357 {
358 	struct hsr_priv *hsr;
359 	struct hsr_port *port;
360 
361 	hsr = netdev_priv(hsr_dev);
362 
363 	rtnl_lock();
364 	hsr_for_each_port(hsr, port)
365 		hsr_del_port(port);
366 	rtnl_unlock();
367 
368 	del_timer_sync(&hsr->prune_timer);
369 	del_timer_sync(&hsr->announce_timer);
370 
371 	synchronize_rcu();
372 	free_netdev(hsr_dev);
373 }
374 
375 static const struct net_device_ops hsr_device_ops = {
376 	.ndo_change_mtu = hsr_dev_change_mtu,
377 	.ndo_open = hsr_dev_open,
378 	.ndo_stop = hsr_dev_close,
379 	.ndo_start_xmit = hsr_dev_xmit,
380 	.ndo_fix_features = hsr_fix_features,
381 };
382 
383 static struct device_type hsr_type = {
384 	.name = "hsr",
385 };
386 
387 void hsr_dev_setup(struct net_device *dev)
388 {
389 	random_ether_addr(dev->dev_addr);
390 
391 	ether_setup(dev);
392 	dev->header_ops = &hsr_header_ops;
393 	dev->netdev_ops = &hsr_device_ops;
394 	SET_NETDEV_DEVTYPE(dev, &hsr_type);
395 	dev->priv_flags |= IFF_NO_QUEUE;
396 
397 	dev->destructor = hsr_dev_destroy;
398 
399 	dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
400 			   NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
401 			   NETIF_F_HW_VLAN_CTAG_TX;
402 
403 	dev->features = dev->hw_features;
404 
405 	/* Prevent recursive tx locking */
406 	dev->features |= NETIF_F_LLTX;
407 	/* VLAN on top of HSR needs testing and probably some work on
408 	 * hsr_header_create() etc.
409 	 */
410 	dev->features |= NETIF_F_VLAN_CHALLENGED;
411 	/* Not sure about this. Taken from bridge code. netdev_features.h says
412 	 * it means "Does not change network namespaces".
413 	 */
414 	dev->features |= NETIF_F_NETNS_LOCAL;
415 }
416 
417 
418 /* Return true if dev is a HSR master; return false otherwise.
419  */
420 inline bool is_hsr_master(struct net_device *dev)
421 {
422 	return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
423 }
424 
425 /* Default multicast address for HSR Supervision frames */
426 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
427 	0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
428 };
429 
430 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
431 		     unsigned char multicast_spec)
432 {
433 	struct hsr_priv *hsr;
434 	struct hsr_port *port;
435 	int res;
436 
437 	hsr = netdev_priv(hsr_dev);
438 	INIT_LIST_HEAD(&hsr->ports);
439 	INIT_LIST_HEAD(&hsr->node_db);
440 	INIT_LIST_HEAD(&hsr->self_node_db);
441 
442 	ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
443 
444 	/* Make sure we recognize frames from ourselves in hsr_rcv() */
445 	res = hsr_create_self_node(&hsr->self_node_db, hsr_dev->dev_addr,
446 				   slave[1]->dev_addr);
447 	if (res < 0)
448 		return res;
449 
450 	spin_lock_init(&hsr->seqnr_lock);
451 	/* Overflow soon to find bugs easier: */
452 	hsr->sequence_nr = HSR_SEQNR_START;
453 
454 	init_timer(&hsr->announce_timer);
455 	hsr->announce_timer.function = hsr_announce;
456 	hsr->announce_timer.data = (unsigned long) hsr;
457 
458 	init_timer(&hsr->prune_timer);
459 	hsr->prune_timer.function = hsr_prune_nodes;
460 	hsr->prune_timer.data = (unsigned long) hsr;
461 
462 	ether_addr_copy(hsr->sup_multicast_addr, def_multicast_addr);
463 	hsr->sup_multicast_addr[ETH_ALEN - 1] = multicast_spec;
464 
465 	/* FIXME: should I modify the value of these?
466 	 *
467 	 * - hsr_dev->flags - i.e.
468 	 *			IFF_MASTER/SLAVE?
469 	 * - hsr_dev->priv_flags - i.e.
470 	 *			IFF_EBRIDGE?
471 	 *			IFF_TX_SKB_SHARING?
472 	 *			IFF_HSR_MASTER/SLAVE?
473 	 */
474 
475 	/* Make sure the 1st call to netif_carrier_on() gets through */
476 	netif_carrier_off(hsr_dev);
477 
478 	res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER);
479 	if (res)
480 		return res;
481 
482 	res = register_netdevice(hsr_dev);
483 	if (res)
484 		goto fail;
485 
486 	res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
487 	if (res)
488 		goto fail;
489 	res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
490 	if (res)
491 		goto fail;
492 
493 	hsr->prune_timer.expires = jiffies + msecs_to_jiffies(PRUNE_PERIOD);
494 	add_timer(&hsr->prune_timer);
495 
496 	return 0;
497 
498 fail:
499 	hsr_for_each_port(hsr, port)
500 		hsr_del_port(port);
501 
502 	return res;
503 }
504