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) && (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
106void 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
122int 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
140static 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
159static 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
195static int hsr_dev_close(struct net_device *dev)
196{
197	/* Nothing to do here. */
198	return 0;
199}
200
201
202static 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
226static 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
235static 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
248static 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 */
257static 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
266static 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
314out:
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 */
322static 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 */
356static 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
375static 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
383static struct device_type hsr_type = {
384	.name = "hsr",
385};
386
387void 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 */
420inline 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 */
426static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
427	0x01, 0x15, 0x4e, 0x00, 0x01, 0x00
428};
429
430int 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
498fail:
499	hsr_for_each_port(hsr, port)
500		hsr_del_port(port);
501
502	return res;
503}
504