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
 27static bool is_admin_up(struct net_device *dev)
 28{
 29	return dev && (dev->flags & IFF_UP);
 30}
 31
 32static bool is_slave_up(struct net_device *dev)
 33{
 34	return dev && is_admin_up(dev) && netif_oper_up(dev);
 35}
 36
 37static 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
 49static 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
 62static 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
 86static 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
107void 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
123int 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
141static 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
160static 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
196static int hsr_dev_close(struct net_device *dev)
197{
198	/* Nothing to do here. */
199	return 0;
200}
201
202
203static 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
227static 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
236static 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
249static const struct header_ops hsr_header_ops = {
250	.create	 = eth_header,
251	.parse	 = eth_header_parse,
252};
253
254static 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 = (typeof(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 = (typeof(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 = (typeof(hsr_sp)) skb_put(skb, sizeof(struct hsr_sup_payload));
315	ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);
316
317	skb_put_padto(skb, ETH_ZLEN + HSR_HLEN);
318
319	hsr_forward_skb(skb, master);
320	return;
321
322out:
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 */
330static void hsr_announce(unsigned long data)
331{
332	struct hsr_priv *hsr;
333	struct hsr_port *master;
334
335	hsr = (struct hsr_priv *) data;
336
337	rcu_read_lock();
338	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
339
340	if (hsr->announce_count < 3 && hsr->protVersion == 0) {
341		send_hsr_supervision_frame(master, HSR_TLV_ANNOUNCE,
342				hsr->protVersion);
343		hsr->announce_count++;
344
345		hsr->announce_timer.expires = jiffies +
346				msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL);
347	} else {
348		send_hsr_supervision_frame(master, HSR_TLV_LIFE_CHECK,
349				hsr->protVersion);
350
351		hsr->announce_timer.expires = jiffies +
352				msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL);
353	}
354
355	if (is_admin_up(master->dev))
356		add_timer(&hsr->announce_timer);
357
358	rcu_read_unlock();
359}
360
361
362/* According to comments in the declaration of struct net_device, this function
363 * is "Called from unregister, can be used to call free_netdev". Ok then...
364 */
365static void hsr_dev_destroy(struct net_device *hsr_dev)
366{
367	struct hsr_priv *hsr;
368	struct hsr_port *port;
369
370	hsr = netdev_priv(hsr_dev);
371
372	rtnl_lock();
373	hsr_for_each_port(hsr, port)
374		hsr_del_port(port);
375	rtnl_unlock();
376
377	del_timer_sync(&hsr->prune_timer);
378	del_timer_sync(&hsr->announce_timer);
379
380	synchronize_rcu();
381	free_netdev(hsr_dev);
382}
383
384static 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
392static struct device_type hsr_type = {
393	.name = "hsr",
394};
395
396void hsr_dev_setup(struct net_device *dev)
397{
398	random_ether_addr(dev->dev_addr);
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->destructor = hsr_dev_destroy;
408
409	dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
410			   NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
411			   NETIF_F_HW_VLAN_CTAG_TX;
412
413	dev->features = dev->hw_features;
414
415	/* Prevent recursive tx locking */
416	dev->features |= NETIF_F_LLTX;
417	/* VLAN on top of HSR needs testing and probably some work on
418	 * hsr_header_create() etc.
419	 */
420	dev->features |= NETIF_F_VLAN_CHALLENGED;
421	/* Not sure about this. Taken from bridge code. netdev_features.h says
422	 * it means "Does not change network namespaces".
423	 */
424	dev->features |= NETIF_F_NETNS_LOCAL;
425}
426
427
428/* Return true if dev is a HSR master; return false otherwise.
429 */
430inline bool is_hsr_master(struct net_device *dev)
431{
432	return (dev->netdev_ops->ndo_start_xmit == hsr_dev_xmit);
433}
434
435/* Default multicast address for HSR Supervision frames */
436static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
437	0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
438};
439
440int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
441		     unsigned char multicast_spec, u8 protocol_version)
442{
443	struct hsr_priv *hsr;
444	struct hsr_port *port;
445	int res;
446
447	hsr = netdev_priv(hsr_dev);
448	INIT_LIST_HEAD(&hsr->ports);
449	INIT_LIST_HEAD(&hsr->node_db);
450	INIT_LIST_HEAD(&hsr->self_node_db);
451
452	ether_addr_copy(hsr_dev->dev_addr, slave[0]->dev_addr);
453
454	/* Make sure we recognize frames from ourselves in hsr_rcv() */
455	res = hsr_create_self_node(&hsr->self_node_db, hsr_dev->dev_addr,
456				   slave[1]->dev_addr);
457	if (res < 0)
458		return res;
459
460	spin_lock_init(&hsr->seqnr_lock);
461	/* Overflow soon to find bugs easier: */
462	hsr->sequence_nr = HSR_SEQNR_START;
463	hsr->sup_sequence_nr = HSR_SUP_SEQNR_START;
464
465	setup_timer(&hsr->announce_timer, hsr_announce, (unsigned long)hsr);
466
467	setup_timer(&hsr->prune_timer, hsr_prune_nodes, (unsigned long)hsr);
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
506fail:
507	hsr_for_each_port(hsr, port)
508		hsr_del_port(port);
509
510	return res;
511}