hsr_framereg.c

  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 * The HSR spec says never to forward the same frame twice on the same
  8 * interface. A frame is identified by its source MAC address and its HSR
  9 * sequence number. This code keeps track of senders and their sequence numbers
 10 * to allow filtering of duplicate frames, and to detect HSR ring errors.
 11 * Same code handles filtering of duplicates for PRP as well.
 12 */
 13
 14#include <linux/if_ether.h>
 15#include <linux/etherdevice.h>
 16#include <linux/slab.h>
 17#include <linux/rculist.h>
 18#include "hsr_main.h"
 19#include "hsr_framereg.h"
 20#include "hsr_netlink.h"
 21
 22/* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
 23 * false otherwise.
 24 */
 25static bool seq_nr_after(u16 a, u16 b)
 26{
 27	/* Remove inconsistency where
 28	 * seq_nr_after(a, b) == seq_nr_before(a, b)
 29	 */
 30	if ((int)b - a == 32768)
 31		return false;
 32
 33	return (((s16)(b - a)) < 0);
 34}
 35
 36#define seq_nr_before(a, b)		seq_nr_after((b), (a))
 37#define seq_nr_before_or_eq(a, b)	(!seq_nr_after((a), (b)))
 38#define PRP_DROP_WINDOW_LEN 32768
 39
 40bool hsr_addr_is_redbox(struct hsr_priv *hsr, unsigned char *addr)
 41{
 42	if (!hsr->redbox || !is_valid_ether_addr(hsr->macaddress_redbox))
 43		return false;
 44
 45	return ether_addr_equal(addr, hsr->macaddress_redbox);
 46}
 47
 48bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr)
 49{
 50	struct hsr_self_node *sn;
 51	bool ret = false;
 52
 53	rcu_read_lock();
 54	sn = rcu_dereference(hsr->self_node);
 55	if (!sn) {
 56		WARN_ONCE(1, "HSR: No self node\n");
 57		goto out;
 58	}
 59
 60	if (ether_addr_equal(addr, sn->macaddress_A) ||
 61	    ether_addr_equal(addr, sn->macaddress_B))
 62		ret = true;
 63out:
 64	rcu_read_unlock();
 65	return ret;
 66}
 67
 68/* Search for mac entry. Caller must hold rcu read lock.
 69 */
 70static struct hsr_node *find_node_by_addr_A(struct list_head *node_db,
 71					    const unsigned char addr[ETH_ALEN])
 72{
 73	struct hsr_node *node;
 74
 75	list_for_each_entry_rcu(node, node_db, mac_list) {
 76		if (ether_addr_equal(node->macaddress_A, addr))
 77			return node;
 78	}
 79
 80	return NULL;
 81}
 82
 83/* Check if node for a given MAC address is already present in data base
 84 */
 85bool hsr_is_node_in_db(struct list_head *node_db,
 86		       const unsigned char addr[ETH_ALEN])
 87{
 88	return !!find_node_by_addr_A(node_db, addr);
 89}
 90
 91/* Helper for device init; the self_node is used in hsr_rcv() to recognize
 92 * frames from self that's been looped over the HSR ring.
 93 */
 94int hsr_create_self_node(struct hsr_priv *hsr,
 95			 const unsigned char addr_a[ETH_ALEN],
 96			 const unsigned char addr_b[ETH_ALEN])
 97{
 98	struct hsr_self_node *sn, *old;
 99
100	sn = kmalloc(sizeof(*sn), GFP_KERNEL);
101	if (!sn)
102		return -ENOMEM;
103
104	ether_addr_copy(sn->macaddress_A, addr_a);
105	ether_addr_copy(sn->macaddress_B, addr_b);
106
107	spin_lock_bh(&hsr->list_lock);
108	old = rcu_replace_pointer(hsr->self_node, sn,
109				  lockdep_is_held(&hsr->list_lock));
110	spin_unlock_bh(&hsr->list_lock);
111
112	if (old)
113		kfree_rcu(old, rcu_head);
114	return 0;
115}
116
117void hsr_del_self_node(struct hsr_priv *hsr)
118{
119	struct hsr_self_node *old;
120
121	spin_lock_bh(&hsr->list_lock);
122	old = rcu_replace_pointer(hsr->self_node, NULL,
123				  lockdep_is_held(&hsr->list_lock));
124	spin_unlock_bh(&hsr->list_lock);
125	if (old)
126		kfree_rcu(old, rcu_head);
127}
128
129void hsr_del_nodes(struct list_head *node_db)
130{
131	struct hsr_node *node;
132	struct hsr_node *tmp;
133
134	list_for_each_entry_safe(node, tmp, node_db, mac_list)
135		kfree(node);
136}
137
138void prp_handle_san_frame(bool san, enum hsr_port_type port,
139			  struct hsr_node *node)
140{
141	/* Mark if the SAN node is over LAN_A or LAN_B */
142	if (port == HSR_PT_SLAVE_A) {
143		node->san_a = true;
144		return;
145	}
146
147	if (port == HSR_PT_SLAVE_B)
148		node->san_b = true;
149}
150
151/* Allocate an hsr_node and add it to node_db. 'addr' is the node's address_A;
152 * seq_out is used to initialize filtering of outgoing duplicate frames
153 * originating from the newly added node.
154 */
155static struct hsr_node *hsr_add_node(struct hsr_priv *hsr,
156				     struct list_head *node_db,
157				     unsigned char addr[],
158				     u16 seq_out, bool san,
159				     enum hsr_port_type rx_port)
160{
161	struct hsr_node *new_node, *node;
162	unsigned long now;
163	int i;
164
165	new_node = kzalloc(sizeof(*new_node), GFP_ATOMIC);
166	if (!new_node)
167		return NULL;
168
169	ether_addr_copy(new_node->macaddress_A, addr);
170	spin_lock_init(&new_node->seq_out_lock);
171
172	/* We are only interested in time diffs here, so use current jiffies
173	 * as initialization. (0 could trigger an spurious ring error warning).
174	 */
175	now = jiffies;
176	for (i = 0; i < HSR_PT_PORTS; i++) {
177		new_node->time_in[i] = now;
178		new_node->time_out[i] = now;
179	}
180	for (i = 0; i < HSR_PT_PORTS; i++) {
181		new_node->seq_out[i] = seq_out;
182		new_node->seq_expected[i] = seq_out + 1;
183		new_node->seq_start[i] = seq_out + 1;
184	}
185
186	if (san && hsr->proto_ops->handle_san_frame)
187		hsr->proto_ops->handle_san_frame(san, rx_port, new_node);
188
189	spin_lock_bh(&hsr->list_lock);
190	list_for_each_entry_rcu(node, node_db, mac_list,
191				lockdep_is_held(&hsr->list_lock)) {
192		if (ether_addr_equal(node->macaddress_A, addr))
193			goto out;
194		if (ether_addr_equal(node->macaddress_B, addr))
195			goto out;
196	}
197	list_add_tail_rcu(&new_node->mac_list, node_db);
198	spin_unlock_bh(&hsr->list_lock);
199	return new_node;
200out:
201	spin_unlock_bh(&hsr->list_lock);
202	kfree(new_node);
203	return node;
204}
205
206void prp_update_san_info(struct hsr_node *node, bool is_sup)
207{
208	if (!is_sup)
209		return;
210
211	node->san_a = false;
212	node->san_b = false;
213}
214
215/* Get the hsr_node from which 'skb' was sent.
216 */
217struct hsr_node *hsr_get_node(struct hsr_port *port, struct list_head *node_db,
218			      struct sk_buff *skb, bool is_sup,
219			      enum hsr_port_type rx_port)
220{
221	struct hsr_priv *hsr = port->hsr;
222	struct hsr_node *node;
223	struct ethhdr *ethhdr;
224	struct prp_rct *rct;
225	bool san = false;
226	u16 seq_out;
227
228	if (!skb_mac_header_was_set(skb))
229		return NULL;
230
231	ethhdr = (struct ethhdr *)skb_mac_header(skb);
232
233	list_for_each_entry_rcu(node, node_db, mac_list) {
234		if (ether_addr_equal(node->macaddress_A, ethhdr->h_source)) {
235			if (hsr->proto_ops->update_san_info)
236				hsr->proto_ops->update_san_info(node, is_sup);
237			return node;
238		}
239		if (ether_addr_equal(node->macaddress_B, ethhdr->h_source)) {
240			if (hsr->proto_ops->update_san_info)
241				hsr->proto_ops->update_san_info(node, is_sup);
242			return node;
243		}
244	}
245
246	/* Check if required node is not in proxy nodes table */
247	list_for_each_entry_rcu(node, &hsr->proxy_node_db, mac_list) {
248		if (ether_addr_equal(node->macaddress_A, ethhdr->h_source)) {
249			if (hsr->proto_ops->update_san_info)
250				hsr->proto_ops->update_san_info(node, is_sup);
251			return node;
252		}
253	}
254
255	/* Everyone may create a node entry, connected node to a HSR/PRP
256	 * device.
257	 */
258	if (ethhdr->h_proto == htons(ETH_P_PRP) ||
259	    ethhdr->h_proto == htons(ETH_P_HSR)) {
260		/* Check if skb contains hsr_ethhdr */
261		if (skb->mac_len < sizeof(struct hsr_ethhdr))
262			return NULL;
263
264		/* Use the existing sequence_nr from the tag as starting point
265		 * for filtering duplicate frames.
266		 */
267		seq_out = hsr_get_skb_sequence_nr(skb) - 1;
268	} else {
269		rct = skb_get_PRP_rct(skb);
270		if (rct && prp_check_lsdu_size(skb, rct, is_sup)) {
271			seq_out = prp_get_skb_sequence_nr(rct);
272		} else {
273			if (rx_port != HSR_PT_MASTER)
274				san = true;
275			seq_out = HSR_SEQNR_START;
276		}
277	}
278
279	return hsr_add_node(hsr, node_db, ethhdr->h_source, seq_out,
280			    san, rx_port);
281}
282
283/* Use the Supervision frame's info about an eventual macaddress_B for merging
284 * nodes that has previously had their macaddress_B registered as a separate
285 * node.
286 */
287void hsr_handle_sup_frame(struct hsr_frame_info *frame)
288{
289	struct hsr_node *node_curr = frame->node_src;
290	struct hsr_port *port_rcv = frame->port_rcv;
291	struct hsr_priv *hsr = port_rcv->hsr;
292	struct hsr_sup_payload *hsr_sp;
293	struct hsr_sup_tlv *hsr_sup_tlv;
294	struct hsr_node *node_real;
295	struct sk_buff *skb = NULL;
296	struct list_head *node_db;
297	struct ethhdr *ethhdr;
298	int i;
299	unsigned int pull_size = 0;
300	unsigned int total_pull_size = 0;
301
302	/* Here either frame->skb_hsr or frame->skb_prp should be
303	 * valid as supervision frame always will have protocol
304	 * header info.
305	 */
306	if (frame->skb_hsr)
307		skb = frame->skb_hsr;
308	else if (frame->skb_prp)
309		skb = frame->skb_prp;
310	else if (frame->skb_std)
311		skb = frame->skb_std;
312	if (!skb)
313		return;
314
315	/* Leave the ethernet header. */
316	pull_size = sizeof(struct ethhdr);
317	skb_pull(skb, pull_size);
318	total_pull_size += pull_size;
319
320	ethhdr = (struct ethhdr *)skb_mac_header(skb);
321
322	/* And leave the HSR tag. */
323	if (ethhdr->h_proto == htons(ETH_P_HSR)) {
324		pull_size = sizeof(struct hsr_tag);
325		skb_pull(skb, pull_size);
326		total_pull_size += pull_size;
327	}
328
329	/* And leave the HSR sup tag. */
330	pull_size = sizeof(struct hsr_sup_tag);
331	skb_pull(skb, pull_size);
332	total_pull_size += pull_size;
333
334	/* get HSR sup payload */
335	hsr_sp = (struct hsr_sup_payload *)skb->data;
336
337	/* Merge node_curr (registered on macaddress_B) into node_real */
338	node_db = &port_rcv->hsr->node_db;
339	node_real = find_node_by_addr_A(node_db, hsr_sp->macaddress_A);
340	if (!node_real)
341		/* No frame received from AddrA of this node yet */
342		node_real = hsr_add_node(hsr, node_db, hsr_sp->macaddress_A,
343					 HSR_SEQNR_START - 1, true,
344					 port_rcv->type);
345	if (!node_real)
346		goto done; /* No mem */
347	if (node_real == node_curr)
348		/* Node has already been merged */
349		goto done;
350
351	/* Leave the first HSR sup payload. */
352	pull_size = sizeof(struct hsr_sup_payload);
353	skb_pull(skb, pull_size);
354	total_pull_size += pull_size;
355
356	/* Get second supervision tlv */
357	hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
358	/* And check if it is a redbox mac TLV */
359	if (hsr_sup_tlv->HSR_TLV_type == PRP_TLV_REDBOX_MAC) {
360		/* We could stop here after pushing hsr_sup_payload,
361		 * or proceed and allow macaddress_B and for redboxes.
362		 */
363		/* Sanity check length */
364		if (hsr_sup_tlv->HSR_TLV_length != 6)
365			goto done;
366
367		/* Leave the second HSR sup tlv. */
368		pull_size = sizeof(struct hsr_sup_tlv);
369		skb_pull(skb, pull_size);
370		total_pull_size += pull_size;
371
372		/* Get redbox mac address. */
373		hsr_sp = (struct hsr_sup_payload *)skb->data;
374
375		/* Check if redbox mac and node mac are equal. */
376		if (!ether_addr_equal(node_real->macaddress_A, hsr_sp->macaddress_A)) {
377			/* This is a redbox supervision frame for a VDAN! */
378			goto done;
379		}
380	}
381
382	ether_addr_copy(node_real->macaddress_B, ethhdr->h_source);
383	spin_lock_bh(&node_real->seq_out_lock);
384	for (i = 0; i < HSR_PT_PORTS; i++) {
385		if (!node_curr->time_in_stale[i] &&
386		    time_after(node_curr->time_in[i], node_real->time_in[i])) {
387			node_real->time_in[i] = node_curr->time_in[i];
388			node_real->time_in_stale[i] =
389						node_curr->time_in_stale[i];
390		}
391		if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
392			node_real->seq_out[i] = node_curr->seq_out[i];
393	}
394	spin_unlock_bh(&node_real->seq_out_lock);
395	node_real->addr_B_port = port_rcv->type;
396
397	spin_lock_bh(&hsr->list_lock);
398	if (!node_curr->removed) {
399		list_del_rcu(&node_curr->mac_list);
400		node_curr->removed = true;
401		kfree_rcu(node_curr, rcu_head);
402	}
403	spin_unlock_bh(&hsr->list_lock);
404
405done:
406	/* Push back here */
407	skb_push(skb, total_pull_size);
408}
409
410/* 'skb' is a frame meant for this host, that is to be passed to upper layers.
411 *
412 * If the frame was sent by a node's B interface, replace the source
413 * address with that node's "official" address (macaddress_A) so that upper
414 * layers recognize where it came from.
415 */
416void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb)
417{
418	if (!skb_mac_header_was_set(skb)) {
419		WARN_ONCE(1, "%s: Mac header not set\n", __func__);
420		return;
421	}
422
423	memcpy(&eth_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN);
424}
425
426/* 'skb' is a frame meant for another host.
427 * 'port' is the outgoing interface
428 *
429 * Substitute the target (dest) MAC address if necessary, so the it matches the
430 * recipient interface MAC address, regardless of whether that is the
431 * recipient's A or B interface.
432 * This is needed to keep the packets flowing through switches that learn on
433 * which "side" the different interfaces are.
434 */
435void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
436			 struct hsr_port *port)
437{
438	struct hsr_node *node_dst;
439
440	if (!skb_mac_header_was_set(skb)) {
441		WARN_ONCE(1, "%s: Mac header not set\n", __func__);
442		return;
443	}
444
445	if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
446		return;
447
448	node_dst = find_node_by_addr_A(&port->hsr->node_db,
449				       eth_hdr(skb)->h_dest);
450	if (!node_dst && port->hsr->redbox)
451		node_dst = find_node_by_addr_A(&port->hsr->proxy_node_db,
452					       eth_hdr(skb)->h_dest);
453
454	if (!node_dst) {
455		if (port->hsr->prot_version != PRP_V1 && net_ratelimit())
456			netdev_err(skb->dev, "%s: Unknown node\n", __func__);
457		return;
458	}
459	if (port->type != node_dst->addr_B_port)
460		return;
461
462	if (is_valid_ether_addr(node_dst->macaddress_B))
463		ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B);
464}
465
466void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
467			   u16 sequence_nr)
468{
469	/* Don't register incoming frames without a valid sequence number. This
470	 * ensures entries of restarted nodes gets pruned so that they can
471	 * re-register and resume communications.
472	 */
473	if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
474	    seq_nr_before(sequence_nr, node->seq_out[port->type]))
475		return;
476
477	node->time_in[port->type] = jiffies;
478	node->time_in_stale[port->type] = false;
479}
480
481/* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
482 * ethhdr->h_source address and skb->mac_header set.
483 *
484 * Return:
485 *	 1 if frame can be shown to have been sent recently on this interface,
486 *	 0 otherwise, or
487 *	 negative error code on error
488 */
489int hsr_register_frame_out(struct hsr_port *port, struct hsr_frame_info *frame)
490{
491	struct hsr_node *node = frame->node_src;
492	u16 sequence_nr = frame->sequence_nr;
493
494	spin_lock_bh(&node->seq_out_lock);
495	if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]) &&
496	    time_is_after_jiffies(node->time_out[port->type] +
497	    msecs_to_jiffies(HSR_ENTRY_FORGET_TIME))) {
498		spin_unlock_bh(&node->seq_out_lock);
499		return 1;
500	}
501
502	node->time_out[port->type] = jiffies;
503	node->seq_out[port->type] = sequence_nr;
504	spin_unlock_bh(&node->seq_out_lock);
505	return 0;
506}
507
508/* Adaptation of the PRP duplicate discard algorithm described in wireshark
509 * wiki (https://wiki.wireshark.org/PRP)
510 *
511 * A drop window is maintained for both LANs with start sequence set to the
512 * first sequence accepted on the LAN that has not been seen on the other LAN,
513 * and expected sequence set to the latest received sequence number plus one.
514 *
515 * When a frame is received on either LAN it is compared against the received
516 * frames on the other LAN. If it is outside the drop window of the other LAN
517 * the frame is accepted and the drop window is updated.
518 * The drop window for the other LAN is reset.
519 *
520 * 'port' is the outgoing interface
521 * 'frame' is the frame to be sent
522 *
523 * Return:
524 *	 1 if frame can be shown to have been sent recently on this interface,
525 *	 0 otherwise
526 */
527int prp_register_frame_out(struct hsr_port *port, struct hsr_frame_info *frame)
528{
529	enum hsr_port_type other_port;
530	enum hsr_port_type rcv_port;
531	struct hsr_node *node;
532	u16 sequence_diff;
533	u16 sequence_exp;
534	u16 sequence_nr;
535
536	/* out-going frames are always in order
537	 * and can be checked the same way as for HSR
538	 */
539	if (frame->port_rcv->type == HSR_PT_MASTER)
540		return hsr_register_frame_out(port, frame);
541
542	/* for PRP we should only forward frames from the slave ports
543	 * to the master port
544	 */
545	if (port->type != HSR_PT_MASTER)
546		return 1;
547
548	node = frame->node_src;
549	sequence_nr = frame->sequence_nr;
550	sequence_exp = sequence_nr + 1;
551	rcv_port = frame->port_rcv->type;
552	other_port = rcv_port == HSR_PT_SLAVE_A ? HSR_PT_SLAVE_B :
553				 HSR_PT_SLAVE_A;
554
555	spin_lock_bh(&node->seq_out_lock);
556	if (time_is_before_jiffies(node->time_out[port->type] +
557	    msecs_to_jiffies(HSR_ENTRY_FORGET_TIME)) ||
558	    (node->seq_start[rcv_port] == node->seq_expected[rcv_port] &&
559	     node->seq_start[other_port] == node->seq_expected[other_port])) {
560		/* the node hasn't been sending for a while
561		 * or both drop windows are empty, forward the frame
562		 */
563		node->seq_start[rcv_port] = sequence_nr;
564	} else if (seq_nr_before(sequence_nr, node->seq_expected[other_port]) &&
565		   seq_nr_before_or_eq(node->seq_start[other_port], sequence_nr)) {
566		/* drop the frame, update the drop window for the other port
567		 * and reset our drop window
568		 */
569		node->seq_start[other_port] = sequence_exp;
570		node->seq_expected[rcv_port] = sequence_exp;
571		node->seq_start[rcv_port] = node->seq_expected[rcv_port];
572		spin_unlock_bh(&node->seq_out_lock);
573		return 1;
574	}
575
576	/* update the drop window for the port where this frame was received
577	 * and clear the drop window for the other port
578	 */
579	node->seq_start[other_port] = node->seq_expected[other_port];
580	node->seq_expected[rcv_port] = sequence_exp;
581	sequence_diff = sequence_exp - node->seq_start[rcv_port];
582	if (sequence_diff > PRP_DROP_WINDOW_LEN)
583		node->seq_start[rcv_port] = sequence_exp - PRP_DROP_WINDOW_LEN;
584
585	node->time_out[port->type] = jiffies;
586	node->seq_out[port->type] = sequence_nr;
587	spin_unlock_bh(&node->seq_out_lock);
588	return 0;
589}
590
591#if IS_MODULE(CONFIG_PRP_DUP_DISCARD_KUNIT_TEST)
592EXPORT_SYMBOL(prp_register_frame_out);
593#endif
594
595static struct hsr_port *get_late_port(struct hsr_priv *hsr,
596				      struct hsr_node *node)
597{
598	if (node->time_in_stale[HSR_PT_SLAVE_A])
599		return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
600	if (node->time_in_stale[HSR_PT_SLAVE_B])
601		return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
602
603	if (time_after(node->time_in[HSR_PT_SLAVE_B],
604		       node->time_in[HSR_PT_SLAVE_A] +
605					msecs_to_jiffies(MAX_SLAVE_DIFF)))
606		return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
607	if (time_after(node->time_in[HSR_PT_SLAVE_A],
608		       node->time_in[HSR_PT_SLAVE_B] +
609					msecs_to_jiffies(MAX_SLAVE_DIFF)))
610		return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
611
612	return NULL;
613}
614
615/* Remove stale sequence_nr records. Called by timer every
616 * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
617 */
618void hsr_prune_nodes(struct timer_list *t)
619{
620	struct hsr_priv *hsr = timer_container_of(hsr, t, prune_timer);
621	struct hsr_node *node;
622	struct hsr_node *tmp;
623	struct hsr_port *port;
624	unsigned long timestamp;
625	unsigned long time_a, time_b;
626
627	spin_lock_bh(&hsr->list_lock);
628	list_for_each_entry_safe(node, tmp, &hsr->node_db, mac_list) {
629		/* Don't prune own node. Neither time_in[HSR_PT_SLAVE_A]
630		 * nor time_in[HSR_PT_SLAVE_B], will ever be updated for
631		 * the master port. Thus the master node will be repeatedly
632		 * pruned leading to packet loss.
633		 */
634		if (hsr_addr_is_self(hsr, node->macaddress_A))
635			continue;
636
637		/* Shorthand */
638		time_a = node->time_in[HSR_PT_SLAVE_A];
639		time_b = node->time_in[HSR_PT_SLAVE_B];
640
641		/* Check for timestamps old enough to risk wrap-around */
642		if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET / 2))
643			node->time_in_stale[HSR_PT_SLAVE_A] = true;
644		if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET / 2))
645			node->time_in_stale[HSR_PT_SLAVE_B] = true;
646
647		/* Get age of newest frame from node.
648		 * At least one time_in is OK here; nodes get pruned long
649		 * before both time_ins can get stale
650		 */
651		timestamp = time_a;
652		if (node->time_in_stale[HSR_PT_SLAVE_A] ||
653		    (!node->time_in_stale[HSR_PT_SLAVE_B] &&
654		    time_after(time_b, time_a)))
655			timestamp = time_b;
656
657		/* Warn of ring error only as long as we get frames at all */
658		if (time_is_after_jiffies(timestamp +
659				msecs_to_jiffies(1.5 * MAX_SLAVE_DIFF))) {
660			rcu_read_lock();
661			port = get_late_port(hsr, node);
662			if (port)
663				hsr_nl_ringerror(hsr, node->macaddress_A, port);
664			rcu_read_unlock();
665		}
666
667		/* Prune old entries */
668		if (time_is_before_jiffies(timestamp +
669				msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
670			hsr_nl_nodedown(hsr, node->macaddress_A);
671			if (!node->removed) {
672				list_del_rcu(&node->mac_list);
673				node->removed = true;
674				/* Note that we need to free this entry later: */
675				kfree_rcu(node, rcu_head);
676			}
677		}
678	}
679	spin_unlock_bh(&hsr->list_lock);
680
681	/* Restart timer */
682	mod_timer(&hsr->prune_timer,
683		  jiffies + msecs_to_jiffies(PRUNE_PERIOD));
684}
685
686void hsr_prune_proxy_nodes(struct timer_list *t)
687{
688	struct hsr_priv *hsr = timer_container_of(hsr, t, prune_proxy_timer);
689	unsigned long timestamp;
690	struct hsr_node *node;
691	struct hsr_node *tmp;
692
693	spin_lock_bh(&hsr->list_lock);
694	list_for_each_entry_safe(node, tmp, &hsr->proxy_node_db, mac_list) {
695		/* Don't prune RedBox node. */
696		if (hsr_addr_is_redbox(hsr, node->macaddress_A))
697			continue;
698
699		timestamp = node->time_in[HSR_PT_INTERLINK];
700
701		/* Prune old entries */
702		if (time_is_before_jiffies(timestamp +
703				msecs_to_jiffies(HSR_PROXY_NODE_FORGET_TIME))) {
704			hsr_nl_nodedown(hsr, node->macaddress_A);
705			if (!node->removed) {
706				list_del_rcu(&node->mac_list);
707				node->removed = true;
708				/* Note that we need to free this entry later: */
709				kfree_rcu(node, rcu_head);
710			}
711		}
712	}
713
714	spin_unlock_bh(&hsr->list_lock);
715
716	/* Restart timer */
717	mod_timer(&hsr->prune_proxy_timer,
718		  jiffies + msecs_to_jiffies(PRUNE_PROXY_PERIOD));
719}
720
721void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
722			unsigned char addr[ETH_ALEN])
723{
724	struct hsr_node *node;
725
726	if (!_pos) {
727		node = list_first_or_null_rcu(&hsr->node_db,
728					      struct hsr_node, mac_list);
729		if (node)
730			ether_addr_copy(addr, node->macaddress_A);
731		return node;
732	}
733
734	node = _pos;
735	list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
736		ether_addr_copy(addr, node->macaddress_A);
737		return node;
738	}
739
740	return NULL;
741}
742
743int hsr_get_node_data(struct hsr_priv *hsr,
744		      const unsigned char *addr,
745		      unsigned char addr_b[ETH_ALEN],
746		      unsigned int *addr_b_ifindex,
747		      int *if1_age,
748		      u16 *if1_seq,
749		      int *if2_age,
750		      u16 *if2_seq)
751{
752	struct hsr_node *node;
753	struct hsr_port *port;
754	unsigned long tdiff;
755
756	node = find_node_by_addr_A(&hsr->node_db, addr);
757	if (!node)
758		return -ENOENT;
759
760	ether_addr_copy(addr_b, node->macaddress_B);
761
762	tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
763	if (node->time_in_stale[HSR_PT_SLAVE_A])
764		*if1_age = INT_MAX;
765#if HZ <= MSEC_PER_SEC
766	else if (tdiff > msecs_to_jiffies(INT_MAX))
767		*if1_age = INT_MAX;
768#endif
769	else
770		*if1_age = jiffies_to_msecs(tdiff);
771
772	tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
773	if (node->time_in_stale[HSR_PT_SLAVE_B])
774		*if2_age = INT_MAX;
775#if HZ <= MSEC_PER_SEC
776	else if (tdiff > msecs_to_jiffies(INT_MAX))
777		*if2_age = INT_MAX;
778#endif
779	else
780		*if2_age = jiffies_to_msecs(tdiff);
781
782	/* Present sequence numbers as if they were incoming on interface */
783	*if1_seq = node->seq_out[HSR_PT_SLAVE_B];
784	*if2_seq = node->seq_out[HSR_PT_SLAVE_A];
785
786	if (node->addr_B_port != HSR_PT_NONE) {
787		port = hsr_port_get_hsr(hsr, node->addr_B_port);
788		*addr_b_ifindex = port->dev->ifindex;
789	} else {
790		*addr_b_ifindex = -1;
791	}
792
793	return 0;
794}