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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
39bool hsr_addr_is_redbox(struct hsr_priv *hsr, unsigned char *addr)
40{
41 if (!hsr->redbox || !is_valid_ether_addr(hsr->macaddress_redbox))
42 return false;
43
44 return ether_addr_equal(addr, hsr->macaddress_redbox);
45}
46
47bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr)
48{
49 struct hsr_self_node *sn;
50 bool ret = false;
51
52 rcu_read_lock();
53 sn = rcu_dereference(hsr->self_node);
54 if (!sn) {
55 WARN_ONCE(1, "HSR: No self node\n");
56 goto out;
57 }
58
59 if (ether_addr_equal(addr, sn->macaddress_A) ||
60 ether_addr_equal(addr, sn->macaddress_B))
61 ret = true;
62out:
63 rcu_read_unlock();
64 return ret;
65}
66
67/* Search for mac entry. Caller must hold rcu read lock.
68 */
69static struct hsr_node *find_node_by_addr_A(struct list_head *node_db,
70 const unsigned char addr[ETH_ALEN])
71{
72 struct hsr_node *node;
73
74 list_for_each_entry_rcu(node, node_db, mac_list) {
75 if (ether_addr_equal(node->macaddress_A, addr))
76 return node;
77 }
78
79 return NULL;
80}
81
82/* Check if node for a given MAC address is already present in data base
83 */
84bool hsr_is_node_in_db(struct list_head *node_db,
85 const unsigned char addr[ETH_ALEN])
86{
87 return !!find_node_by_addr_A(node_db, addr);
88}
89
90/* Helper for device init; the self_node is used in hsr_rcv() to recognize
91 * frames from self that's been looped over the HSR ring.
92 */
93int hsr_create_self_node(struct hsr_priv *hsr,
94 const unsigned char addr_a[ETH_ALEN],
95 const unsigned char addr_b[ETH_ALEN])
96{
97 struct hsr_self_node *sn, *old;
98
99 sn = kmalloc(sizeof(*sn), GFP_KERNEL);
100 if (!sn)
101 return -ENOMEM;
102
103 ether_addr_copy(sn->macaddress_A, addr_a);
104 ether_addr_copy(sn->macaddress_B, addr_b);
105
106 spin_lock_bh(&hsr->list_lock);
107 old = rcu_replace_pointer(hsr->self_node, sn,
108 lockdep_is_held(&hsr->list_lock));
109 spin_unlock_bh(&hsr->list_lock);
110
111 if (old)
112 kfree_rcu(old, rcu_head);
113 return 0;
114}
115
116void hsr_del_self_node(struct hsr_priv *hsr)
117{
118 struct hsr_self_node *old;
119
120 spin_lock_bh(&hsr->list_lock);
121 old = rcu_replace_pointer(hsr->self_node, NULL,
122 lockdep_is_held(&hsr->list_lock));
123 spin_unlock_bh(&hsr->list_lock);
124 if (old)
125 kfree_rcu(old, rcu_head);
126}
127
128void hsr_del_nodes(struct list_head *node_db)
129{
130 struct hsr_node *node;
131 struct hsr_node *tmp;
132
133 list_for_each_entry_safe(node, tmp, node_db, mac_list)
134 kfree(node);
135}
136
137void prp_handle_san_frame(bool san, enum hsr_port_type port,
138 struct hsr_node *node)
139{
140 /* Mark if the SAN node is over LAN_A or LAN_B */
141 if (port == HSR_PT_SLAVE_A) {
142 node->san_a = true;
143 return;
144 }
145
146 if (port == HSR_PT_SLAVE_B)
147 node->san_b = true;
148}
149
150/* Allocate an hsr_node and add it to node_db. 'addr' is the node's address_A;
151 * seq_out is used to initialize filtering of outgoing duplicate frames
152 * originating from the newly added node.
153 */
154static struct hsr_node *hsr_add_node(struct hsr_priv *hsr,
155 struct list_head *node_db,
156 unsigned char addr[],
157 u16 seq_out, bool san,
158 enum hsr_port_type rx_port)
159{
160 struct hsr_node *new_node, *node;
161 unsigned long now;
162 int i;
163
164 new_node = kzalloc(sizeof(*new_node), GFP_ATOMIC);
165 if (!new_node)
166 return NULL;
167
168 ether_addr_copy(new_node->macaddress_A, addr);
169 spin_lock_init(&new_node->seq_out_lock);
170
171 /* We are only interested in time diffs here, so use current jiffies
172 * as initialization. (0 could trigger an spurious ring error warning).
173 */
174 now = jiffies;
175 for (i = 0; i < HSR_PT_PORTS; i++) {
176 new_node->time_in[i] = now;
177 new_node->time_out[i] = now;
178 }
179 for (i = 0; i < HSR_PT_PORTS; i++)
180 new_node->seq_out[i] = seq_out;
181
182 if (san && hsr->proto_ops->handle_san_frame)
183 hsr->proto_ops->handle_san_frame(san, rx_port, new_node);
184
185 spin_lock_bh(&hsr->list_lock);
186 list_for_each_entry_rcu(node, node_db, mac_list,
187 lockdep_is_held(&hsr->list_lock)) {
188 if (ether_addr_equal(node->macaddress_A, addr))
189 goto out;
190 if (ether_addr_equal(node->macaddress_B, addr))
191 goto out;
192 }
193 list_add_tail_rcu(&new_node->mac_list, node_db);
194 spin_unlock_bh(&hsr->list_lock);
195 return new_node;
196out:
197 spin_unlock_bh(&hsr->list_lock);
198 kfree(new_node);
199 return node;
200}
201
202void prp_update_san_info(struct hsr_node *node, bool is_sup)
203{
204 if (!is_sup)
205 return;
206
207 node->san_a = false;
208 node->san_b = false;
209}
210
211/* Get the hsr_node from which 'skb' was sent.
212 */
213struct hsr_node *hsr_get_node(struct hsr_port *port, struct list_head *node_db,
214 struct sk_buff *skb, bool is_sup,
215 enum hsr_port_type rx_port)
216{
217 struct hsr_priv *hsr = port->hsr;
218 struct hsr_node *node;
219 struct ethhdr *ethhdr;
220 struct prp_rct *rct;
221 bool san = false;
222 u16 seq_out;
223
224 if (!skb_mac_header_was_set(skb))
225 return NULL;
226
227 ethhdr = (struct ethhdr *)skb_mac_header(skb);
228
229 list_for_each_entry_rcu(node, node_db, mac_list) {
230 if (ether_addr_equal(node->macaddress_A, ethhdr->h_source)) {
231 if (hsr->proto_ops->update_san_info)
232 hsr->proto_ops->update_san_info(node, is_sup);
233 return node;
234 }
235 if (ether_addr_equal(node->macaddress_B, ethhdr->h_source)) {
236 if (hsr->proto_ops->update_san_info)
237 hsr->proto_ops->update_san_info(node, is_sup);
238 return node;
239 }
240 }
241
242 /* Check if required node is not in proxy nodes table */
243 list_for_each_entry_rcu(node, &hsr->proxy_node_db, mac_list) {
244 if (ether_addr_equal(node->macaddress_A, ethhdr->h_source)) {
245 if (hsr->proto_ops->update_san_info)
246 hsr->proto_ops->update_san_info(node, is_sup);
247 return node;
248 }
249 }
250
251 /* Everyone may create a node entry, connected node to a HSR/PRP
252 * device.
253 */
254 if (ethhdr->h_proto == htons(ETH_P_PRP) ||
255 ethhdr->h_proto == htons(ETH_P_HSR)) {
256 /* Check if skb contains hsr_ethhdr */
257 if (skb->mac_len < sizeof(struct hsr_ethhdr))
258 return NULL;
259
260 /* Use the existing sequence_nr from the tag as starting point
261 * for filtering duplicate frames.
262 */
263 seq_out = hsr_get_skb_sequence_nr(skb) - 1;
264 } else {
265 rct = skb_get_PRP_rct(skb);
266 if (rct && prp_check_lsdu_size(skb, rct, is_sup)) {
267 seq_out = prp_get_skb_sequence_nr(rct);
268 } else {
269 if (rx_port != HSR_PT_MASTER)
270 san = true;
271 seq_out = HSR_SEQNR_START;
272 }
273 }
274
275 return hsr_add_node(hsr, node_db, ethhdr->h_source, seq_out,
276 san, rx_port);
277}
278
279/* Use the Supervision frame's info about an eventual macaddress_B for merging
280 * nodes that has previously had their macaddress_B registered as a separate
281 * node.
282 */
283void hsr_handle_sup_frame(struct hsr_frame_info *frame)
284{
285 struct hsr_node *node_curr = frame->node_src;
286 struct hsr_port *port_rcv = frame->port_rcv;
287 struct hsr_priv *hsr = port_rcv->hsr;
288 struct hsr_sup_payload *hsr_sp;
289 struct hsr_sup_tlv *hsr_sup_tlv;
290 struct hsr_node *node_real;
291 struct sk_buff *skb = NULL;
292 struct list_head *node_db;
293 struct ethhdr *ethhdr;
294 int i;
295 unsigned int pull_size = 0;
296 unsigned int total_pull_size = 0;
297
298 /* Here either frame->skb_hsr or frame->skb_prp should be
299 * valid as supervision frame always will have protocol
300 * header info.
301 */
302 if (frame->skb_hsr)
303 skb = frame->skb_hsr;
304 else if (frame->skb_prp)
305 skb = frame->skb_prp;
306 else if (frame->skb_std)
307 skb = frame->skb_std;
308 if (!skb)
309 return;
310
311 /* Leave the ethernet header. */
312 pull_size = sizeof(struct ethhdr);
313 skb_pull(skb, pull_size);
314 total_pull_size += pull_size;
315
316 ethhdr = (struct ethhdr *)skb_mac_header(skb);
317
318 /* And leave the HSR tag. */
319 if (ethhdr->h_proto == htons(ETH_P_HSR)) {
320 pull_size = sizeof(struct hsr_tag);
321 skb_pull(skb, pull_size);
322 total_pull_size += pull_size;
323 }
324
325 /* And leave the HSR sup tag. */
326 pull_size = sizeof(struct hsr_sup_tag);
327 skb_pull(skb, pull_size);
328 total_pull_size += pull_size;
329
330 /* get HSR sup payload */
331 hsr_sp = (struct hsr_sup_payload *)skb->data;
332
333 /* Merge node_curr (registered on macaddress_B) into node_real */
334 node_db = &port_rcv->hsr->node_db;
335 node_real = find_node_by_addr_A(node_db, hsr_sp->macaddress_A);
336 if (!node_real)
337 /* No frame received from AddrA of this node yet */
338 node_real = hsr_add_node(hsr, node_db, hsr_sp->macaddress_A,
339 HSR_SEQNR_START - 1, true,
340 port_rcv->type);
341 if (!node_real)
342 goto done; /* No mem */
343 if (node_real == node_curr)
344 /* Node has already been merged */
345 goto done;
346
347 /* Leave the first HSR sup payload. */
348 pull_size = sizeof(struct hsr_sup_payload);
349 skb_pull(skb, pull_size);
350 total_pull_size += pull_size;
351
352 /* Get second supervision tlv */
353 hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
354 /* And check if it is a redbox mac TLV */
355 if (hsr_sup_tlv->HSR_TLV_type == PRP_TLV_REDBOX_MAC) {
356 /* We could stop here after pushing hsr_sup_payload,
357 * or proceed and allow macaddress_B and for redboxes.
358 */
359 /* Sanity check length */
360 if (hsr_sup_tlv->HSR_TLV_length != 6)
361 goto done;
362
363 /* Leave the second HSR sup tlv. */
364 pull_size = sizeof(struct hsr_sup_tlv);
365 skb_pull(skb, pull_size);
366 total_pull_size += pull_size;
367
368 /* Get redbox mac address. */
369 hsr_sp = (struct hsr_sup_payload *)skb->data;
370
371 /* Check if redbox mac and node mac are equal. */
372 if (!ether_addr_equal(node_real->macaddress_A, hsr_sp->macaddress_A)) {
373 /* This is a redbox supervision frame for a VDAN! */
374 goto done;
375 }
376 }
377
378 ether_addr_copy(node_real->macaddress_B, ethhdr->h_source);
379 spin_lock_bh(&node_real->seq_out_lock);
380 for (i = 0; i < HSR_PT_PORTS; i++) {
381 if (!node_curr->time_in_stale[i] &&
382 time_after(node_curr->time_in[i], node_real->time_in[i])) {
383 node_real->time_in[i] = node_curr->time_in[i];
384 node_real->time_in_stale[i] =
385 node_curr->time_in_stale[i];
386 }
387 if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
388 node_real->seq_out[i] = node_curr->seq_out[i];
389 }
390 spin_unlock_bh(&node_real->seq_out_lock);
391 node_real->addr_B_port = port_rcv->type;
392
393 spin_lock_bh(&hsr->list_lock);
394 if (!node_curr->removed) {
395 list_del_rcu(&node_curr->mac_list);
396 node_curr->removed = true;
397 kfree_rcu(node_curr, rcu_head);
398 }
399 spin_unlock_bh(&hsr->list_lock);
400
401done:
402 /* Push back here */
403 skb_push(skb, total_pull_size);
404}
405
406/* 'skb' is a frame meant for this host, that is to be passed to upper layers.
407 *
408 * If the frame was sent by a node's B interface, replace the source
409 * address with that node's "official" address (macaddress_A) so that upper
410 * layers recognize where it came from.
411 */
412void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb)
413{
414 if (!skb_mac_header_was_set(skb)) {
415 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
416 return;
417 }
418
419 memcpy(ð_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN);
420}
421
422/* 'skb' is a frame meant for another host.
423 * 'port' is the outgoing interface
424 *
425 * Substitute the target (dest) MAC address if necessary, so the it matches the
426 * recipient interface MAC address, regardless of whether that is the
427 * recipient's A or B interface.
428 * This is needed to keep the packets flowing through switches that learn on
429 * which "side" the different interfaces are.
430 */
431void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
432 struct hsr_port *port)
433{
434 struct hsr_node *node_dst;
435
436 if (!skb_mac_header_was_set(skb)) {
437 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
438 return;
439 }
440
441 if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
442 return;
443
444 node_dst = find_node_by_addr_A(&port->hsr->node_db,
445 eth_hdr(skb)->h_dest);
446 if (!node_dst && port->hsr->redbox)
447 node_dst = find_node_by_addr_A(&port->hsr->proxy_node_db,
448 eth_hdr(skb)->h_dest);
449
450 if (!node_dst) {
451 if (port->hsr->prot_version != PRP_V1 && net_ratelimit())
452 netdev_err(skb->dev, "%s: Unknown node\n", __func__);
453 return;
454 }
455 if (port->type != node_dst->addr_B_port)
456 return;
457
458 if (is_valid_ether_addr(node_dst->macaddress_B))
459 ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B);
460}
461
462void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
463 u16 sequence_nr)
464{
465 /* Don't register incoming frames without a valid sequence number. This
466 * ensures entries of restarted nodes gets pruned so that they can
467 * re-register and resume communications.
468 */
469 if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
470 seq_nr_before(sequence_nr, node->seq_out[port->type]))
471 return;
472
473 node->time_in[port->type] = jiffies;
474 node->time_in_stale[port->type] = false;
475}
476
477/* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
478 * ethhdr->h_source address and skb->mac_header set.
479 *
480 * Return:
481 * 1 if frame can be shown to have been sent recently on this interface,
482 * 0 otherwise, or
483 * negative error code on error
484 */
485int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
486 u16 sequence_nr)
487{
488 spin_lock_bh(&node->seq_out_lock);
489 if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]) &&
490 time_is_after_jiffies(node->time_out[port->type] +
491 msecs_to_jiffies(HSR_ENTRY_FORGET_TIME))) {
492 spin_unlock_bh(&node->seq_out_lock);
493 return 1;
494 }
495
496 node->time_out[port->type] = jiffies;
497 node->seq_out[port->type] = sequence_nr;
498 spin_unlock_bh(&node->seq_out_lock);
499 return 0;
500}
501
502static struct hsr_port *get_late_port(struct hsr_priv *hsr,
503 struct hsr_node *node)
504{
505 if (node->time_in_stale[HSR_PT_SLAVE_A])
506 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
507 if (node->time_in_stale[HSR_PT_SLAVE_B])
508 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
509
510 if (time_after(node->time_in[HSR_PT_SLAVE_B],
511 node->time_in[HSR_PT_SLAVE_A] +
512 msecs_to_jiffies(MAX_SLAVE_DIFF)))
513 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
514 if (time_after(node->time_in[HSR_PT_SLAVE_A],
515 node->time_in[HSR_PT_SLAVE_B] +
516 msecs_to_jiffies(MAX_SLAVE_DIFF)))
517 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
518
519 return NULL;
520}
521
522/* Remove stale sequence_nr records. Called by timer every
523 * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
524 */
525void hsr_prune_nodes(struct timer_list *t)
526{
527 struct hsr_priv *hsr = from_timer(hsr, t, prune_timer);
528 struct hsr_node *node;
529 struct hsr_node *tmp;
530 struct hsr_port *port;
531 unsigned long timestamp;
532 unsigned long time_a, time_b;
533
534 spin_lock_bh(&hsr->list_lock);
535 list_for_each_entry_safe(node, tmp, &hsr->node_db, mac_list) {
536 /* Don't prune own node. Neither time_in[HSR_PT_SLAVE_A]
537 * nor time_in[HSR_PT_SLAVE_B], will ever be updated for
538 * the master port. Thus the master node will be repeatedly
539 * pruned leading to packet loss.
540 */
541 if (hsr_addr_is_self(hsr, node->macaddress_A))
542 continue;
543
544 /* Shorthand */
545 time_a = node->time_in[HSR_PT_SLAVE_A];
546 time_b = node->time_in[HSR_PT_SLAVE_B];
547
548 /* Check for timestamps old enough to risk wrap-around */
549 if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET / 2))
550 node->time_in_stale[HSR_PT_SLAVE_A] = true;
551 if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET / 2))
552 node->time_in_stale[HSR_PT_SLAVE_B] = true;
553
554 /* Get age of newest frame from node.
555 * At least one time_in is OK here; nodes get pruned long
556 * before both time_ins can get stale
557 */
558 timestamp = time_a;
559 if (node->time_in_stale[HSR_PT_SLAVE_A] ||
560 (!node->time_in_stale[HSR_PT_SLAVE_B] &&
561 time_after(time_b, time_a)))
562 timestamp = time_b;
563
564 /* Warn of ring error only as long as we get frames at all */
565 if (time_is_after_jiffies(timestamp +
566 msecs_to_jiffies(1.5 * MAX_SLAVE_DIFF))) {
567 rcu_read_lock();
568 port = get_late_port(hsr, node);
569 if (port)
570 hsr_nl_ringerror(hsr, node->macaddress_A, port);
571 rcu_read_unlock();
572 }
573
574 /* Prune old entries */
575 if (time_is_before_jiffies(timestamp +
576 msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
577 hsr_nl_nodedown(hsr, node->macaddress_A);
578 if (!node->removed) {
579 list_del_rcu(&node->mac_list);
580 node->removed = true;
581 /* Note that we need to free this entry later: */
582 kfree_rcu(node, rcu_head);
583 }
584 }
585 }
586 spin_unlock_bh(&hsr->list_lock);
587
588 /* Restart timer */
589 mod_timer(&hsr->prune_timer,
590 jiffies + msecs_to_jiffies(PRUNE_PERIOD));
591}
592
593void hsr_prune_proxy_nodes(struct timer_list *t)
594{
595 struct hsr_priv *hsr = from_timer(hsr, t, prune_proxy_timer);
596 unsigned long timestamp;
597 struct hsr_node *node;
598 struct hsr_node *tmp;
599
600 spin_lock_bh(&hsr->list_lock);
601 list_for_each_entry_safe(node, tmp, &hsr->proxy_node_db, mac_list) {
602 /* Don't prune RedBox node. */
603 if (hsr_addr_is_redbox(hsr, node->macaddress_A))
604 continue;
605
606 timestamp = node->time_in[HSR_PT_INTERLINK];
607
608 /* Prune old entries */
609 if (time_is_before_jiffies(timestamp +
610 msecs_to_jiffies(HSR_PROXY_NODE_FORGET_TIME))) {
611 hsr_nl_nodedown(hsr, node->macaddress_A);
612 if (!node->removed) {
613 list_del_rcu(&node->mac_list);
614 node->removed = true;
615 /* Note that we need to free this entry later: */
616 kfree_rcu(node, rcu_head);
617 }
618 }
619 }
620
621 spin_unlock_bh(&hsr->list_lock);
622
623 /* Restart timer */
624 mod_timer(&hsr->prune_proxy_timer,
625 jiffies + msecs_to_jiffies(PRUNE_PROXY_PERIOD));
626}
627
628void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
629 unsigned char addr[ETH_ALEN])
630{
631 struct hsr_node *node;
632
633 if (!_pos) {
634 node = list_first_or_null_rcu(&hsr->node_db,
635 struct hsr_node, mac_list);
636 if (node)
637 ether_addr_copy(addr, node->macaddress_A);
638 return node;
639 }
640
641 node = _pos;
642 list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
643 ether_addr_copy(addr, node->macaddress_A);
644 return node;
645 }
646
647 return NULL;
648}
649
650int hsr_get_node_data(struct hsr_priv *hsr,
651 const unsigned char *addr,
652 unsigned char addr_b[ETH_ALEN],
653 unsigned int *addr_b_ifindex,
654 int *if1_age,
655 u16 *if1_seq,
656 int *if2_age,
657 u16 *if2_seq)
658{
659 struct hsr_node *node;
660 struct hsr_port *port;
661 unsigned long tdiff;
662
663 node = find_node_by_addr_A(&hsr->node_db, addr);
664 if (!node)
665 return -ENOENT;
666
667 ether_addr_copy(addr_b, node->macaddress_B);
668
669 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
670 if (node->time_in_stale[HSR_PT_SLAVE_A])
671 *if1_age = INT_MAX;
672#if HZ <= MSEC_PER_SEC
673 else if (tdiff > msecs_to_jiffies(INT_MAX))
674 *if1_age = INT_MAX;
675#endif
676 else
677 *if1_age = jiffies_to_msecs(tdiff);
678
679 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
680 if (node->time_in_stale[HSR_PT_SLAVE_B])
681 *if2_age = INT_MAX;
682#if HZ <= MSEC_PER_SEC
683 else if (tdiff > msecs_to_jiffies(INT_MAX))
684 *if2_age = INT_MAX;
685#endif
686 else
687 *if2_age = jiffies_to_msecs(tdiff);
688
689 /* Present sequence numbers as if they were incoming on interface */
690 *if1_seq = node->seq_out[HSR_PT_SLAVE_B];
691 *if2_seq = node->seq_out[HSR_PT_SLAVE_A];
692
693 if (node->addr_B_port != HSR_PT_NONE) {
694 port = hsr_port_get_hsr(hsr, node->addr_B_port);
695 *addr_b_ifindex = port->dev->ifindex;
696 } else {
697 *addr_b_ifindex = -1;
698 }
699
700 return 0;
701}
1/* Copyright 2011-2013 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 * 2011-2013 Arvid Brodin, arvid.brodin@xdin.com
10 *
11 * The HSR spec says never to forward the same frame twice on the same
12 * interface. A frame is identified by its source MAC address and its HSR
13 * sequence number. This code keeps track of senders and their sequence numbers
14 * to allow filtering of duplicate frames, and to detect HSR ring errors.
15 */
16
17#include <linux/if_ether.h>
18#include <linux/etherdevice.h>
19#include <linux/slab.h>
20#include <linux/rculist.h>
21#include "hsr_main.h"
22#include "hsr_framereg.h"
23#include "hsr_netlink.h"
24
25
26struct node_entry {
27 struct list_head mac_list;
28 unsigned char MacAddressA[ETH_ALEN];
29 unsigned char MacAddressB[ETH_ALEN];
30 enum hsr_dev_idx AddrB_if; /* The local slave through which AddrB
31 * frames are received from this node
32 */
33 unsigned long time_in[HSR_MAX_SLAVE];
34 bool time_in_stale[HSR_MAX_SLAVE];
35 u16 seq_out[HSR_MAX_DEV];
36 struct rcu_head rcu_head;
37};
38
39/* TODO: use hash lists for mac addresses (linux/jhash.h)? */
40
41
42
43/* Search for mac entry. Caller must hold rcu read lock.
44 */
45static struct node_entry *find_node_by_AddrA(struct list_head *node_db,
46 const unsigned char addr[ETH_ALEN])
47{
48 struct node_entry *node;
49
50 list_for_each_entry_rcu(node, node_db, mac_list) {
51 if (ether_addr_equal(node->MacAddressA, addr))
52 return node;
53 }
54
55 return NULL;
56}
57
58
59/* Search for mac entry. Caller must hold rcu read lock.
60 */
61static struct node_entry *find_node_by_AddrB(struct list_head *node_db,
62 const unsigned char addr[ETH_ALEN])
63{
64 struct node_entry *node;
65
66 list_for_each_entry_rcu(node, node_db, mac_list) {
67 if (ether_addr_equal(node->MacAddressB, addr))
68 return node;
69 }
70
71 return NULL;
72}
73
74
75/* Search for mac entry. Caller must hold rcu read lock.
76 */
77struct node_entry *hsr_find_node(struct list_head *node_db, struct sk_buff *skb)
78{
79 struct node_entry *node;
80 struct ethhdr *ethhdr;
81
82 if (!skb_mac_header_was_set(skb))
83 return NULL;
84
85 ethhdr = (struct ethhdr *) skb_mac_header(skb);
86
87 list_for_each_entry_rcu(node, node_db, mac_list) {
88 if (ether_addr_equal(node->MacAddressA, ethhdr->h_source))
89 return node;
90 if (ether_addr_equal(node->MacAddressB, ethhdr->h_source))
91 return node;
92 }
93
94 return NULL;
95}
96
97
98/* Helper for device init; the self_node_db is used in hsr_rcv() to recognize
99 * frames from self that's been looped over the HSR ring.
100 */
101int hsr_create_self_node(struct list_head *self_node_db,
102 unsigned char addr_a[ETH_ALEN],
103 unsigned char addr_b[ETH_ALEN])
104{
105 struct node_entry *node, *oldnode;
106
107 node = kmalloc(sizeof(*node), GFP_KERNEL);
108 if (!node)
109 return -ENOMEM;
110
111 ether_addr_copy(node->MacAddressA, addr_a);
112 ether_addr_copy(node->MacAddressB, addr_b);
113
114 rcu_read_lock();
115 oldnode = list_first_or_null_rcu(self_node_db,
116 struct node_entry, mac_list);
117 if (oldnode) {
118 list_replace_rcu(&oldnode->mac_list, &node->mac_list);
119 rcu_read_unlock();
120 synchronize_rcu();
121 kfree(oldnode);
122 } else {
123 rcu_read_unlock();
124 list_add_tail_rcu(&node->mac_list, self_node_db);
125 }
126
127 return 0;
128}
129
130
131/* Add/merge node to the database of nodes. 'skb' must contain an HSR
132 * supervision frame.
133 * - If the supervision header's MacAddressA field is not yet in the database,
134 * this frame is from an hitherto unknown node - add it to the database.
135 * - If the sender's MAC address is not the same as its MacAddressA address,
136 * the node is using PICS_SUBS (address substitution). Record the sender's
137 * address as the node's MacAddressB.
138 *
139 * This function needs to work even if the sender node has changed one of its
140 * slaves' MAC addresses. In this case, there are four different cases described
141 * by (Addr-changed, received-from) pairs as follows. Note that changing the
142 * SlaveA address is equal to changing the node's own address:
143 *
144 * - (AddrB, SlaveB): The new AddrB will be recorded by PICS_SUBS code since
145 * node == NULL.
146 * - (AddrB, SlaveA): Will work as usual (the AddrB change won't be detected
147 * from this frame).
148 *
149 * - (AddrA, SlaveB): The old node will be found. We need to detect this and
150 * remove the node.
151 * - (AddrA, SlaveA): A new node will be registered (non-PICS_SUBS at first).
152 * The old one will be pruned after HSR_NODE_FORGET_TIME.
153 *
154 * We also need to detect if the sender's SlaveA and SlaveB cables have been
155 * swapped.
156 */
157struct node_entry *hsr_merge_node(struct hsr_priv *hsr_priv,
158 struct node_entry *node,
159 struct sk_buff *skb,
160 enum hsr_dev_idx dev_idx)
161{
162 struct hsr_sup_payload *hsr_sp;
163 struct hsr_ethhdr_sp *hsr_ethsup;
164 int i;
165 unsigned long now;
166
167 hsr_ethsup = (struct hsr_ethhdr_sp *) skb_mac_header(skb);
168 hsr_sp = (struct hsr_sup_payload *) skb->data;
169
170 if (node && !ether_addr_equal(node->MacAddressA, hsr_sp->MacAddressA)) {
171 /* Node has changed its AddrA, frame was received from SlaveB */
172 list_del_rcu(&node->mac_list);
173 kfree_rcu(node, rcu_head);
174 node = NULL;
175 }
176
177 if (node && (dev_idx == node->AddrB_if) &&
178 !ether_addr_equal(node->MacAddressB, hsr_ethsup->ethhdr.h_source)) {
179 /* Cables have been swapped */
180 list_del_rcu(&node->mac_list);
181 kfree_rcu(node, rcu_head);
182 node = NULL;
183 }
184
185 if (node && (dev_idx != node->AddrB_if) &&
186 (node->AddrB_if != HSR_DEV_NONE) &&
187 !ether_addr_equal(node->MacAddressA, hsr_ethsup->ethhdr.h_source)) {
188 /* Cables have been swapped */
189 list_del_rcu(&node->mac_list);
190 kfree_rcu(node, rcu_head);
191 node = NULL;
192 }
193
194 if (node)
195 return node;
196
197 node = find_node_by_AddrA(&hsr_priv->node_db, hsr_sp->MacAddressA);
198 if (node) {
199 /* Node is known, but frame was received from an unknown
200 * address. Node is PICS_SUBS capable; merge its AddrB.
201 */
202 ether_addr_copy(node->MacAddressB, hsr_ethsup->ethhdr.h_source);
203 node->AddrB_if = dev_idx;
204 return node;
205 }
206
207 node = kzalloc(sizeof(*node), GFP_ATOMIC);
208 if (!node)
209 return NULL;
210
211 ether_addr_copy(node->MacAddressA, hsr_sp->MacAddressA);
212 ether_addr_copy(node->MacAddressB, hsr_ethsup->ethhdr.h_source);
213 if (!ether_addr_equal(hsr_sp->MacAddressA, hsr_ethsup->ethhdr.h_source))
214 node->AddrB_if = dev_idx;
215 else
216 node->AddrB_if = HSR_DEV_NONE;
217
218 /* We are only interested in time diffs here, so use current jiffies
219 * as initialization. (0 could trigger an spurious ring error warning).
220 */
221 now = jiffies;
222 for (i = 0; i < HSR_MAX_SLAVE; i++)
223 node->time_in[i] = now;
224 for (i = 0; i < HSR_MAX_DEV; i++)
225 node->seq_out[i] = ntohs(hsr_ethsup->hsr_sup.sequence_nr) - 1;
226
227 list_add_tail_rcu(&node->mac_list, &hsr_priv->node_db);
228
229 return node;
230}
231
232
233/* 'skb' is a frame meant for this host, that is to be passed to upper layers.
234 *
235 * If the frame was sent by a node's B interface, replace the sender
236 * address with that node's "official" address (MacAddressA) so that upper
237 * layers recognize where it came from.
238 */
239void hsr_addr_subst_source(struct hsr_priv *hsr_priv, struct sk_buff *skb)
240{
241 struct ethhdr *ethhdr;
242 struct node_entry *node;
243
244 if (!skb_mac_header_was_set(skb)) {
245 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
246 return;
247 }
248 ethhdr = (struct ethhdr *) skb_mac_header(skb);
249
250 rcu_read_lock();
251 node = find_node_by_AddrB(&hsr_priv->node_db, ethhdr->h_source);
252 if (node)
253 ether_addr_copy(ethhdr->h_source, node->MacAddressA);
254 rcu_read_unlock();
255}
256
257
258/* 'skb' is a frame meant for another host.
259 * 'hsr_dev_idx' is the HSR index of the outgoing device
260 *
261 * Substitute the target (dest) MAC address if necessary, so the it matches the
262 * recipient interface MAC address, regardless of whether that is the
263 * recipient's A or B interface.
264 * This is needed to keep the packets flowing through switches that learn on
265 * which "side" the different interfaces are.
266 */
267void hsr_addr_subst_dest(struct hsr_priv *hsr_priv, struct ethhdr *ethhdr,
268 enum hsr_dev_idx dev_idx)
269{
270 struct node_entry *node;
271
272 rcu_read_lock();
273 node = find_node_by_AddrA(&hsr_priv->node_db, ethhdr->h_dest);
274 if (node && (node->AddrB_if == dev_idx))
275 ether_addr_copy(ethhdr->h_dest, node->MacAddressB);
276 rcu_read_unlock();
277}
278
279
280/* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
281 * false otherwise.
282 */
283static bool seq_nr_after(u16 a, u16 b)
284{
285 /* Remove inconsistency where
286 * seq_nr_after(a, b) == seq_nr_before(a, b)
287 */
288 if ((int) b - a == 32768)
289 return false;
290
291 return (((s16) (b - a)) < 0);
292}
293#define seq_nr_before(a, b) seq_nr_after((b), (a))
294#define seq_nr_after_or_eq(a, b) (!seq_nr_before((a), (b)))
295#define seq_nr_before_or_eq(a, b) (!seq_nr_after((a), (b)))
296
297
298void hsr_register_frame_in(struct node_entry *node, enum hsr_dev_idx dev_idx)
299{
300 if ((dev_idx < 0) || (dev_idx >= HSR_MAX_SLAVE)) {
301 WARN_ONCE(1, "%s: Invalid dev_idx (%d)\n", __func__, dev_idx);
302 return;
303 }
304 node->time_in[dev_idx] = jiffies;
305 node->time_in_stale[dev_idx] = false;
306}
307
308
309/* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
310 * ethhdr->h_source address and skb->mac_header set.
311 *
312 * Return:
313 * 1 if frame can be shown to have been sent recently on this interface,
314 * 0 otherwise, or
315 * negative error code on error
316 */
317int hsr_register_frame_out(struct node_entry *node, enum hsr_dev_idx dev_idx,
318 struct sk_buff *skb)
319{
320 struct hsr_ethhdr *hsr_ethhdr;
321 u16 sequence_nr;
322
323 if ((dev_idx < 0) || (dev_idx >= HSR_MAX_DEV)) {
324 WARN_ONCE(1, "%s: Invalid dev_idx (%d)\n", __func__, dev_idx);
325 return -EINVAL;
326 }
327 if (!skb_mac_header_was_set(skb)) {
328 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
329 return -EINVAL;
330 }
331 hsr_ethhdr = (struct hsr_ethhdr *) skb_mac_header(skb);
332
333 sequence_nr = ntohs(hsr_ethhdr->hsr_tag.sequence_nr);
334 if (seq_nr_before_or_eq(sequence_nr, node->seq_out[dev_idx]))
335 return 1;
336
337 node->seq_out[dev_idx] = sequence_nr;
338 return 0;
339}
340
341
342
343static bool is_late(struct node_entry *node, enum hsr_dev_idx dev_idx)
344{
345 enum hsr_dev_idx other;
346
347 if (node->time_in_stale[dev_idx])
348 return true;
349
350 if (dev_idx == HSR_DEV_SLAVE_A)
351 other = HSR_DEV_SLAVE_B;
352 else
353 other = HSR_DEV_SLAVE_A;
354
355 if (node->time_in_stale[other])
356 return false;
357
358 if (time_after(node->time_in[other], node->time_in[dev_idx] +
359 msecs_to_jiffies(MAX_SLAVE_DIFF)))
360 return true;
361
362 return false;
363}
364
365
366/* Remove stale sequence_nr records. Called by timer every
367 * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
368 */
369void hsr_prune_nodes(struct hsr_priv *hsr_priv)
370{
371 struct node_entry *node;
372 unsigned long timestamp;
373 unsigned long time_a, time_b;
374
375 rcu_read_lock();
376 list_for_each_entry_rcu(node, &hsr_priv->node_db, mac_list) {
377 /* Shorthand */
378 time_a = node->time_in[HSR_DEV_SLAVE_A];
379 time_b = node->time_in[HSR_DEV_SLAVE_B];
380
381 /* Check for timestamps old enough to risk wrap-around */
382 if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET/2))
383 node->time_in_stale[HSR_DEV_SLAVE_A] = true;
384 if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET/2))
385 node->time_in_stale[HSR_DEV_SLAVE_B] = true;
386
387 /* Get age of newest frame from node.
388 * At least one time_in is OK here; nodes get pruned long
389 * before both time_ins can get stale
390 */
391 timestamp = time_a;
392 if (node->time_in_stale[HSR_DEV_SLAVE_A] ||
393 (!node->time_in_stale[HSR_DEV_SLAVE_B] &&
394 time_after(time_b, time_a)))
395 timestamp = time_b;
396
397 /* Warn of ring error only as long as we get frames at all */
398 if (time_is_after_jiffies(timestamp +
399 msecs_to_jiffies(1.5*MAX_SLAVE_DIFF))) {
400
401 if (is_late(node, HSR_DEV_SLAVE_A))
402 hsr_nl_ringerror(hsr_priv, node->MacAddressA,
403 HSR_DEV_SLAVE_A);
404 else if (is_late(node, HSR_DEV_SLAVE_B))
405 hsr_nl_ringerror(hsr_priv, node->MacAddressA,
406 HSR_DEV_SLAVE_B);
407 }
408
409 /* Prune old entries */
410 if (time_is_before_jiffies(timestamp +
411 msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
412 hsr_nl_nodedown(hsr_priv, node->MacAddressA);
413 list_del_rcu(&node->mac_list);
414 /* Note that we need to free this entry later: */
415 kfree_rcu(node, rcu_head);
416 }
417 }
418 rcu_read_unlock();
419}
420
421
422void *hsr_get_next_node(struct hsr_priv *hsr_priv, void *_pos,
423 unsigned char addr[ETH_ALEN])
424{
425 struct node_entry *node;
426
427 if (!_pos) {
428 node = list_first_or_null_rcu(&hsr_priv->node_db,
429 struct node_entry, mac_list);
430 if (node)
431 ether_addr_copy(addr, node->MacAddressA);
432 return node;
433 }
434
435 node = _pos;
436 list_for_each_entry_continue_rcu(node, &hsr_priv->node_db, mac_list) {
437 ether_addr_copy(addr, node->MacAddressA);
438 return node;
439 }
440
441 return NULL;
442}
443
444
445int hsr_get_node_data(struct hsr_priv *hsr_priv,
446 const unsigned char *addr,
447 unsigned char addr_b[ETH_ALEN],
448 unsigned int *addr_b_ifindex,
449 int *if1_age,
450 u16 *if1_seq,
451 int *if2_age,
452 u16 *if2_seq)
453{
454 struct node_entry *node;
455 unsigned long tdiff;
456
457
458 rcu_read_lock();
459 node = find_node_by_AddrA(&hsr_priv->node_db, addr);
460 if (!node) {
461 rcu_read_unlock();
462 return -ENOENT; /* No such entry */
463 }
464
465 ether_addr_copy(addr_b, node->MacAddressB);
466
467 tdiff = jiffies - node->time_in[HSR_DEV_SLAVE_A];
468 if (node->time_in_stale[HSR_DEV_SLAVE_A])
469 *if1_age = INT_MAX;
470#if HZ <= MSEC_PER_SEC
471 else if (tdiff > msecs_to_jiffies(INT_MAX))
472 *if1_age = INT_MAX;
473#endif
474 else
475 *if1_age = jiffies_to_msecs(tdiff);
476
477 tdiff = jiffies - node->time_in[HSR_DEV_SLAVE_B];
478 if (node->time_in_stale[HSR_DEV_SLAVE_B])
479 *if2_age = INT_MAX;
480#if HZ <= MSEC_PER_SEC
481 else if (tdiff > msecs_to_jiffies(INT_MAX))
482 *if2_age = INT_MAX;
483#endif
484 else
485 *if2_age = jiffies_to_msecs(tdiff);
486
487 /* Present sequence numbers as if they were incoming on interface */
488 *if1_seq = node->seq_out[HSR_DEV_SLAVE_B];
489 *if2_seq = node->seq_out[HSR_DEV_SLAVE_A];
490
491 if ((node->AddrB_if != HSR_DEV_NONE) && hsr_priv->slave[node->AddrB_if])
492 *addr_b_ifindex = hsr_priv->slave[node->AddrB_if]->ifindex;
493 else
494 *addr_b_ifindex = -1;
495
496 rcu_read_unlock();
497
498 return 0;
499}