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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_self(struct hsr_priv *hsr, unsigned char *addr)
40{
41 struct hsr_self_node *sn;
42 bool ret = false;
43
44 rcu_read_lock();
45 sn = rcu_dereference(hsr->self_node);
46 if (!sn) {
47 WARN_ONCE(1, "HSR: No self node\n");
48 goto out;
49 }
50
51 if (ether_addr_equal(addr, sn->macaddress_A) ||
52 ether_addr_equal(addr, sn->macaddress_B))
53 ret = true;
54out:
55 rcu_read_unlock();
56 return ret;
57}
58
59/* Search for mac entry. Caller must hold rcu read lock.
60 */
61static struct hsr_node *find_node_by_addr_A(struct list_head *node_db,
62 const unsigned char addr[ETH_ALEN])
63{
64 struct hsr_node *node;
65
66 list_for_each_entry_rcu(node, node_db, mac_list) {
67 if (ether_addr_equal(node->macaddress_A, addr))
68 return node;
69 }
70
71 return NULL;
72}
73
74/* Helper for device init; the self_node is used in hsr_rcv() to recognize
75 * frames from self that's been looped over the HSR ring.
76 */
77int hsr_create_self_node(struct hsr_priv *hsr,
78 const unsigned char addr_a[ETH_ALEN],
79 const unsigned char addr_b[ETH_ALEN])
80{
81 struct hsr_self_node *sn, *old;
82
83 sn = kmalloc(sizeof(*sn), GFP_KERNEL);
84 if (!sn)
85 return -ENOMEM;
86
87 ether_addr_copy(sn->macaddress_A, addr_a);
88 ether_addr_copy(sn->macaddress_B, addr_b);
89
90 spin_lock_bh(&hsr->list_lock);
91 old = rcu_replace_pointer(hsr->self_node, sn,
92 lockdep_is_held(&hsr->list_lock));
93 spin_unlock_bh(&hsr->list_lock);
94
95 if (old)
96 kfree_rcu(old, rcu_head);
97 return 0;
98}
99
100void hsr_del_self_node(struct hsr_priv *hsr)
101{
102 struct hsr_self_node *old;
103
104 spin_lock_bh(&hsr->list_lock);
105 old = rcu_replace_pointer(hsr->self_node, NULL,
106 lockdep_is_held(&hsr->list_lock));
107 spin_unlock_bh(&hsr->list_lock);
108 if (old)
109 kfree_rcu(old, rcu_head);
110}
111
112void hsr_del_nodes(struct list_head *node_db)
113{
114 struct hsr_node *node;
115 struct hsr_node *tmp;
116
117 list_for_each_entry_safe(node, tmp, node_db, mac_list)
118 kfree(node);
119}
120
121void prp_handle_san_frame(bool san, enum hsr_port_type port,
122 struct hsr_node *node)
123{
124 /* Mark if the SAN node is over LAN_A or LAN_B */
125 if (port == HSR_PT_SLAVE_A) {
126 node->san_a = true;
127 return;
128 }
129
130 if (port == HSR_PT_SLAVE_B)
131 node->san_b = true;
132}
133
134/* Allocate an hsr_node and add it to node_db. 'addr' is the node's address_A;
135 * seq_out is used to initialize filtering of outgoing duplicate frames
136 * originating from the newly added node.
137 */
138static struct hsr_node *hsr_add_node(struct hsr_priv *hsr,
139 struct list_head *node_db,
140 unsigned char addr[],
141 u16 seq_out, bool san,
142 enum hsr_port_type rx_port)
143{
144 struct hsr_node *new_node, *node;
145 unsigned long now;
146 int i;
147
148 new_node = kzalloc(sizeof(*new_node), GFP_ATOMIC);
149 if (!new_node)
150 return NULL;
151
152 ether_addr_copy(new_node->macaddress_A, addr);
153 spin_lock_init(&new_node->seq_out_lock);
154
155 /* We are only interested in time diffs here, so use current jiffies
156 * as initialization. (0 could trigger an spurious ring error warning).
157 */
158 now = jiffies;
159 for (i = 0; i < HSR_PT_PORTS; i++) {
160 new_node->time_in[i] = now;
161 new_node->time_out[i] = now;
162 }
163 for (i = 0; i < HSR_PT_PORTS; i++)
164 new_node->seq_out[i] = seq_out;
165
166 if (san && hsr->proto_ops->handle_san_frame)
167 hsr->proto_ops->handle_san_frame(san, rx_port, new_node);
168
169 spin_lock_bh(&hsr->list_lock);
170 list_for_each_entry_rcu(node, node_db, mac_list,
171 lockdep_is_held(&hsr->list_lock)) {
172 if (ether_addr_equal(node->macaddress_A, addr))
173 goto out;
174 if (ether_addr_equal(node->macaddress_B, addr))
175 goto out;
176 }
177 list_add_tail_rcu(&new_node->mac_list, node_db);
178 spin_unlock_bh(&hsr->list_lock);
179 return new_node;
180out:
181 spin_unlock_bh(&hsr->list_lock);
182 kfree(new_node);
183 return node;
184}
185
186void prp_update_san_info(struct hsr_node *node, bool is_sup)
187{
188 if (!is_sup)
189 return;
190
191 node->san_a = false;
192 node->san_b = false;
193}
194
195/* Get the hsr_node from which 'skb' was sent.
196 */
197struct hsr_node *hsr_get_node(struct hsr_port *port, struct list_head *node_db,
198 struct sk_buff *skb, bool is_sup,
199 enum hsr_port_type rx_port)
200{
201 struct hsr_priv *hsr = port->hsr;
202 struct hsr_node *node;
203 struct ethhdr *ethhdr;
204 struct prp_rct *rct;
205 bool san = false;
206 u16 seq_out;
207
208 if (!skb_mac_header_was_set(skb))
209 return NULL;
210
211 ethhdr = (struct ethhdr *)skb_mac_header(skb);
212
213 list_for_each_entry_rcu(node, node_db, mac_list) {
214 if (ether_addr_equal(node->macaddress_A, ethhdr->h_source)) {
215 if (hsr->proto_ops->update_san_info)
216 hsr->proto_ops->update_san_info(node, is_sup);
217 return node;
218 }
219 if (ether_addr_equal(node->macaddress_B, ethhdr->h_source)) {
220 if (hsr->proto_ops->update_san_info)
221 hsr->proto_ops->update_san_info(node, is_sup);
222 return node;
223 }
224 }
225
226 /* Everyone may create a node entry, connected node to a HSR/PRP
227 * device.
228 */
229 if (ethhdr->h_proto == htons(ETH_P_PRP) ||
230 ethhdr->h_proto == htons(ETH_P_HSR)) {
231 /* Use the existing sequence_nr from the tag as starting point
232 * for filtering duplicate frames.
233 */
234 seq_out = hsr_get_skb_sequence_nr(skb) - 1;
235 } else {
236 rct = skb_get_PRP_rct(skb);
237 if (rct && prp_check_lsdu_size(skb, rct, is_sup)) {
238 seq_out = prp_get_skb_sequence_nr(rct);
239 } else {
240 if (rx_port != HSR_PT_MASTER)
241 san = true;
242 seq_out = HSR_SEQNR_START;
243 }
244 }
245
246 return hsr_add_node(hsr, node_db, ethhdr->h_source, seq_out,
247 san, rx_port);
248}
249
250/* Use the Supervision frame's info about an eventual macaddress_B for merging
251 * nodes that has previously had their macaddress_B registered as a separate
252 * node.
253 */
254void hsr_handle_sup_frame(struct hsr_frame_info *frame)
255{
256 struct hsr_node *node_curr = frame->node_src;
257 struct hsr_port *port_rcv = frame->port_rcv;
258 struct hsr_priv *hsr = port_rcv->hsr;
259 struct hsr_sup_payload *hsr_sp;
260 struct hsr_sup_tlv *hsr_sup_tlv;
261 struct hsr_node *node_real;
262 struct sk_buff *skb = NULL;
263 struct list_head *node_db;
264 struct ethhdr *ethhdr;
265 int i;
266 unsigned int pull_size = 0;
267 unsigned int total_pull_size = 0;
268
269 /* Here either frame->skb_hsr or frame->skb_prp should be
270 * valid as supervision frame always will have protocol
271 * header info.
272 */
273 if (frame->skb_hsr)
274 skb = frame->skb_hsr;
275 else if (frame->skb_prp)
276 skb = frame->skb_prp;
277 else if (frame->skb_std)
278 skb = frame->skb_std;
279 if (!skb)
280 return;
281
282 /* Leave the ethernet header. */
283 pull_size = sizeof(struct ethhdr);
284 skb_pull(skb, pull_size);
285 total_pull_size += pull_size;
286
287 ethhdr = (struct ethhdr *)skb_mac_header(skb);
288
289 /* And leave the HSR tag. */
290 if (ethhdr->h_proto == htons(ETH_P_HSR)) {
291 pull_size = sizeof(struct ethhdr);
292 skb_pull(skb, pull_size);
293 total_pull_size += pull_size;
294 }
295
296 /* And leave the HSR sup tag. */
297 pull_size = sizeof(struct hsr_tag);
298 skb_pull(skb, pull_size);
299 total_pull_size += pull_size;
300
301 /* get HSR sup payload */
302 hsr_sp = (struct hsr_sup_payload *)skb->data;
303
304 /* Merge node_curr (registered on macaddress_B) into node_real */
305 node_db = &port_rcv->hsr->node_db;
306 node_real = find_node_by_addr_A(node_db, hsr_sp->macaddress_A);
307 if (!node_real)
308 /* No frame received from AddrA of this node yet */
309 node_real = hsr_add_node(hsr, node_db, hsr_sp->macaddress_A,
310 HSR_SEQNR_START - 1, true,
311 port_rcv->type);
312 if (!node_real)
313 goto done; /* No mem */
314 if (node_real == node_curr)
315 /* Node has already been merged */
316 goto done;
317
318 /* Leave the first HSR sup payload. */
319 pull_size = sizeof(struct hsr_sup_payload);
320 skb_pull(skb, pull_size);
321 total_pull_size += pull_size;
322
323 /* Get second supervision tlv */
324 hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
325 /* And check if it is a redbox mac TLV */
326 if (hsr_sup_tlv->HSR_TLV_type == PRP_TLV_REDBOX_MAC) {
327 /* We could stop here after pushing hsr_sup_payload,
328 * or proceed and allow macaddress_B and for redboxes.
329 */
330 /* Sanity check length */
331 if (hsr_sup_tlv->HSR_TLV_length != 6)
332 goto done;
333
334 /* Leave the second HSR sup tlv. */
335 pull_size = sizeof(struct hsr_sup_tlv);
336 skb_pull(skb, pull_size);
337 total_pull_size += pull_size;
338
339 /* Get redbox mac address. */
340 hsr_sp = (struct hsr_sup_payload *)skb->data;
341
342 /* Check if redbox mac and node mac are equal. */
343 if (!ether_addr_equal(node_real->macaddress_A, hsr_sp->macaddress_A)) {
344 /* This is a redbox supervision frame for a VDAN! */
345 goto done;
346 }
347 }
348
349 ether_addr_copy(node_real->macaddress_B, ethhdr->h_source);
350 spin_lock_bh(&node_real->seq_out_lock);
351 for (i = 0; i < HSR_PT_PORTS; i++) {
352 if (!node_curr->time_in_stale[i] &&
353 time_after(node_curr->time_in[i], node_real->time_in[i])) {
354 node_real->time_in[i] = node_curr->time_in[i];
355 node_real->time_in_stale[i] =
356 node_curr->time_in_stale[i];
357 }
358 if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
359 node_real->seq_out[i] = node_curr->seq_out[i];
360 }
361 spin_unlock_bh(&node_real->seq_out_lock);
362 node_real->addr_B_port = port_rcv->type;
363
364 spin_lock_bh(&hsr->list_lock);
365 if (!node_curr->removed) {
366 list_del_rcu(&node_curr->mac_list);
367 node_curr->removed = true;
368 kfree_rcu(node_curr, rcu_head);
369 }
370 spin_unlock_bh(&hsr->list_lock);
371
372done:
373 /* Push back here */
374 skb_push(skb, total_pull_size);
375}
376
377/* 'skb' is a frame meant for this host, that is to be passed to upper layers.
378 *
379 * If the frame was sent by a node's B interface, replace the source
380 * address with that node's "official" address (macaddress_A) so that upper
381 * layers recognize where it came from.
382 */
383void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb)
384{
385 if (!skb_mac_header_was_set(skb)) {
386 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
387 return;
388 }
389
390 memcpy(ð_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN);
391}
392
393/* 'skb' is a frame meant for another host.
394 * 'port' is the outgoing interface
395 *
396 * Substitute the target (dest) MAC address if necessary, so the it matches the
397 * recipient interface MAC address, regardless of whether that is the
398 * recipient's A or B interface.
399 * This is needed to keep the packets flowing through switches that learn on
400 * which "side" the different interfaces are.
401 */
402void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
403 struct hsr_port *port)
404{
405 struct hsr_node *node_dst;
406
407 if (!skb_mac_header_was_set(skb)) {
408 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
409 return;
410 }
411
412 if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
413 return;
414
415 node_dst = find_node_by_addr_A(&port->hsr->node_db,
416 eth_hdr(skb)->h_dest);
417 if (!node_dst) {
418 if (net_ratelimit())
419 netdev_err(skb->dev, "%s: Unknown node\n", __func__);
420 return;
421 }
422 if (port->type != node_dst->addr_B_port)
423 return;
424
425 if (is_valid_ether_addr(node_dst->macaddress_B))
426 ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B);
427}
428
429void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
430 u16 sequence_nr)
431{
432 /* Don't register incoming frames without a valid sequence number. This
433 * ensures entries of restarted nodes gets pruned so that they can
434 * re-register and resume communications.
435 */
436 if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
437 seq_nr_before(sequence_nr, node->seq_out[port->type]))
438 return;
439
440 node->time_in[port->type] = jiffies;
441 node->time_in_stale[port->type] = false;
442}
443
444/* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
445 * ethhdr->h_source address and skb->mac_header set.
446 *
447 * Return:
448 * 1 if frame can be shown to have been sent recently on this interface,
449 * 0 otherwise, or
450 * negative error code on error
451 */
452int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
453 u16 sequence_nr)
454{
455 spin_lock_bh(&node->seq_out_lock);
456 if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]) &&
457 time_is_after_jiffies(node->time_out[port->type] +
458 msecs_to_jiffies(HSR_ENTRY_FORGET_TIME))) {
459 spin_unlock_bh(&node->seq_out_lock);
460 return 1;
461 }
462
463 node->time_out[port->type] = jiffies;
464 node->seq_out[port->type] = sequence_nr;
465 spin_unlock_bh(&node->seq_out_lock);
466 return 0;
467}
468
469static struct hsr_port *get_late_port(struct hsr_priv *hsr,
470 struct hsr_node *node)
471{
472 if (node->time_in_stale[HSR_PT_SLAVE_A])
473 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
474 if (node->time_in_stale[HSR_PT_SLAVE_B])
475 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
476
477 if (time_after(node->time_in[HSR_PT_SLAVE_B],
478 node->time_in[HSR_PT_SLAVE_A] +
479 msecs_to_jiffies(MAX_SLAVE_DIFF)))
480 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
481 if (time_after(node->time_in[HSR_PT_SLAVE_A],
482 node->time_in[HSR_PT_SLAVE_B] +
483 msecs_to_jiffies(MAX_SLAVE_DIFF)))
484 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
485
486 return NULL;
487}
488
489/* Remove stale sequence_nr records. Called by timer every
490 * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
491 */
492void hsr_prune_nodes(struct timer_list *t)
493{
494 struct hsr_priv *hsr = from_timer(hsr, t, prune_timer);
495 struct hsr_node *node;
496 struct hsr_node *tmp;
497 struct hsr_port *port;
498 unsigned long timestamp;
499 unsigned long time_a, time_b;
500
501 spin_lock_bh(&hsr->list_lock);
502 list_for_each_entry_safe(node, tmp, &hsr->node_db, mac_list) {
503 /* Don't prune own node. Neither time_in[HSR_PT_SLAVE_A]
504 * nor time_in[HSR_PT_SLAVE_B], will ever be updated for
505 * the master port. Thus the master node will be repeatedly
506 * pruned leading to packet loss.
507 */
508 if (hsr_addr_is_self(hsr, node->macaddress_A))
509 continue;
510
511 /* Shorthand */
512 time_a = node->time_in[HSR_PT_SLAVE_A];
513 time_b = node->time_in[HSR_PT_SLAVE_B];
514
515 /* Check for timestamps old enough to risk wrap-around */
516 if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET / 2))
517 node->time_in_stale[HSR_PT_SLAVE_A] = true;
518 if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET / 2))
519 node->time_in_stale[HSR_PT_SLAVE_B] = true;
520
521 /* Get age of newest frame from node.
522 * At least one time_in is OK here; nodes get pruned long
523 * before both time_ins can get stale
524 */
525 timestamp = time_a;
526 if (node->time_in_stale[HSR_PT_SLAVE_A] ||
527 (!node->time_in_stale[HSR_PT_SLAVE_B] &&
528 time_after(time_b, time_a)))
529 timestamp = time_b;
530
531 /* Warn of ring error only as long as we get frames at all */
532 if (time_is_after_jiffies(timestamp +
533 msecs_to_jiffies(1.5 * MAX_SLAVE_DIFF))) {
534 rcu_read_lock();
535 port = get_late_port(hsr, node);
536 if (port)
537 hsr_nl_ringerror(hsr, node->macaddress_A, port);
538 rcu_read_unlock();
539 }
540
541 /* Prune old entries */
542 if (time_is_before_jiffies(timestamp +
543 msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
544 hsr_nl_nodedown(hsr, node->macaddress_A);
545 if (!node->removed) {
546 list_del_rcu(&node->mac_list);
547 node->removed = true;
548 /* Note that we need to free this entry later: */
549 kfree_rcu(node, rcu_head);
550 }
551 }
552 }
553 spin_unlock_bh(&hsr->list_lock);
554
555 /* Restart timer */
556 mod_timer(&hsr->prune_timer,
557 jiffies + msecs_to_jiffies(PRUNE_PERIOD));
558}
559
560void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
561 unsigned char addr[ETH_ALEN])
562{
563 struct hsr_node *node;
564
565 if (!_pos) {
566 node = list_first_or_null_rcu(&hsr->node_db,
567 struct hsr_node, mac_list);
568 if (node)
569 ether_addr_copy(addr, node->macaddress_A);
570 return node;
571 }
572
573 node = _pos;
574 list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
575 ether_addr_copy(addr, node->macaddress_A);
576 return node;
577 }
578
579 return NULL;
580}
581
582int hsr_get_node_data(struct hsr_priv *hsr,
583 const unsigned char *addr,
584 unsigned char addr_b[ETH_ALEN],
585 unsigned int *addr_b_ifindex,
586 int *if1_age,
587 u16 *if1_seq,
588 int *if2_age,
589 u16 *if2_seq)
590{
591 struct hsr_node *node;
592 struct hsr_port *port;
593 unsigned long tdiff;
594
595 node = find_node_by_addr_A(&hsr->node_db, addr);
596 if (!node)
597 return -ENOENT;
598
599 ether_addr_copy(addr_b, node->macaddress_B);
600
601 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
602 if (node->time_in_stale[HSR_PT_SLAVE_A])
603 *if1_age = INT_MAX;
604#if HZ <= MSEC_PER_SEC
605 else if (tdiff > msecs_to_jiffies(INT_MAX))
606 *if1_age = INT_MAX;
607#endif
608 else
609 *if1_age = jiffies_to_msecs(tdiff);
610
611 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
612 if (node->time_in_stale[HSR_PT_SLAVE_B])
613 *if2_age = INT_MAX;
614#if HZ <= MSEC_PER_SEC
615 else if (tdiff > msecs_to_jiffies(INT_MAX))
616 *if2_age = INT_MAX;
617#endif
618 else
619 *if2_age = jiffies_to_msecs(tdiff);
620
621 /* Present sequence numbers as if they were incoming on interface */
622 *if1_seq = node->seq_out[HSR_PT_SLAVE_B];
623 *if2_seq = node->seq_out[HSR_PT_SLAVE_A];
624
625 if (node->addr_B_port != HSR_PT_NONE) {
626 port = hsr_port_get_hsr(hsr, node->addr_B_port);
627 *addr_b_ifindex = port->dev->ifindex;
628 } else {
629 *addr_b_ifindex = -1;
630 }
631
632 return 0;
633}
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/* TODO: use hash lists for mac addresses (linux/jhash.h)? */
23
24/* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
25 * false otherwise.
26 */
27static bool seq_nr_after(u16 a, u16 b)
28{
29 /* Remove inconsistency where
30 * seq_nr_after(a, b) == seq_nr_before(a, b)
31 */
32 if ((int)b - a == 32768)
33 return false;
34
35 return (((s16)(b - a)) < 0);
36}
37
38#define seq_nr_before(a, b) seq_nr_after((b), (a))
39#define seq_nr_before_or_eq(a, b) (!seq_nr_after((a), (b)))
40
41bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr)
42{
43 struct hsr_node *node;
44
45 node = list_first_or_null_rcu(&hsr->self_node_db, struct hsr_node,
46 mac_list);
47 if (!node) {
48 WARN_ONCE(1, "HSR: No self node\n");
49 return false;
50 }
51
52 if (ether_addr_equal(addr, node->macaddress_A))
53 return true;
54 if (ether_addr_equal(addr, node->macaddress_B))
55 return true;
56
57 return false;
58}
59
60/* Search for mac entry. Caller must hold rcu read lock.
61 */
62static struct hsr_node *find_node_by_addr_A(struct list_head *node_db,
63 const unsigned char addr[ETH_ALEN])
64{
65 struct hsr_node *node;
66
67 list_for_each_entry_rcu(node, node_db, mac_list) {
68 if (ether_addr_equal(node->macaddress_A, addr))
69 return node;
70 }
71
72 return NULL;
73}
74
75/* Helper for device init; the self_node_db is used in hsr_rcv() to recognize
76 * frames from self that's been looped over the HSR ring.
77 */
78int hsr_create_self_node(struct hsr_priv *hsr,
79 unsigned char addr_a[ETH_ALEN],
80 unsigned char addr_b[ETH_ALEN])
81{
82 struct list_head *self_node_db = &hsr->self_node_db;
83 struct hsr_node *node, *oldnode;
84
85 node = kmalloc(sizeof(*node), GFP_KERNEL);
86 if (!node)
87 return -ENOMEM;
88
89 ether_addr_copy(node->macaddress_A, addr_a);
90 ether_addr_copy(node->macaddress_B, addr_b);
91
92 spin_lock_bh(&hsr->list_lock);
93 oldnode = list_first_or_null_rcu(self_node_db,
94 struct hsr_node, mac_list);
95 if (oldnode) {
96 list_replace_rcu(&oldnode->mac_list, &node->mac_list);
97 spin_unlock_bh(&hsr->list_lock);
98 kfree_rcu(oldnode, rcu_head);
99 } else {
100 list_add_tail_rcu(&node->mac_list, self_node_db);
101 spin_unlock_bh(&hsr->list_lock);
102 }
103
104 return 0;
105}
106
107void hsr_del_self_node(struct hsr_priv *hsr)
108{
109 struct list_head *self_node_db = &hsr->self_node_db;
110 struct hsr_node *node;
111
112 spin_lock_bh(&hsr->list_lock);
113 node = list_first_or_null_rcu(self_node_db, struct hsr_node, mac_list);
114 if (node) {
115 list_del_rcu(&node->mac_list);
116 kfree_rcu(node, rcu_head);
117 }
118 spin_unlock_bh(&hsr->list_lock);
119}
120
121void hsr_del_nodes(struct list_head *node_db)
122{
123 struct hsr_node *node;
124 struct hsr_node *tmp;
125
126 list_for_each_entry_safe(node, tmp, node_db, mac_list)
127 kfree(node);
128}
129
130void prp_handle_san_frame(bool san, enum hsr_port_type port,
131 struct hsr_node *node)
132{
133 /* Mark if the SAN node is over LAN_A or LAN_B */
134 if (port == HSR_PT_SLAVE_A) {
135 node->san_a = true;
136 return;
137 }
138
139 if (port == HSR_PT_SLAVE_B)
140 node->san_b = true;
141}
142
143/* Allocate an hsr_node and add it to node_db. 'addr' is the node's address_A;
144 * seq_out is used to initialize filtering of outgoing duplicate frames
145 * originating from the newly added node.
146 */
147static struct hsr_node *hsr_add_node(struct hsr_priv *hsr,
148 struct list_head *node_db,
149 unsigned char addr[],
150 u16 seq_out, bool san,
151 enum hsr_port_type rx_port)
152{
153 struct hsr_node *new_node, *node;
154 unsigned long now;
155 int i;
156
157 new_node = kzalloc(sizeof(*new_node), GFP_ATOMIC);
158 if (!new_node)
159 return NULL;
160
161 ether_addr_copy(new_node->macaddress_A, addr);
162
163 /* We are only interested in time diffs here, so use current jiffies
164 * as initialization. (0 could trigger an spurious ring error warning).
165 */
166 now = jiffies;
167 for (i = 0; i < HSR_PT_PORTS; i++) {
168 new_node->time_in[i] = now;
169 new_node->time_out[i] = now;
170 }
171 for (i = 0; i < HSR_PT_PORTS; i++)
172 new_node->seq_out[i] = seq_out;
173
174 if (san && hsr->proto_ops->handle_san_frame)
175 hsr->proto_ops->handle_san_frame(san, rx_port, new_node);
176
177 spin_lock_bh(&hsr->list_lock);
178 list_for_each_entry_rcu(node, node_db, mac_list,
179 lockdep_is_held(&hsr->list_lock)) {
180 if (ether_addr_equal(node->macaddress_A, addr))
181 goto out;
182 if (ether_addr_equal(node->macaddress_B, addr))
183 goto out;
184 }
185 list_add_tail_rcu(&new_node->mac_list, node_db);
186 spin_unlock_bh(&hsr->list_lock);
187 return new_node;
188out:
189 spin_unlock_bh(&hsr->list_lock);
190 kfree(new_node);
191 return node;
192}
193
194void prp_update_san_info(struct hsr_node *node, bool is_sup)
195{
196 if (!is_sup)
197 return;
198
199 node->san_a = false;
200 node->san_b = false;
201}
202
203/* Get the hsr_node from which 'skb' was sent.
204 */
205struct hsr_node *hsr_get_node(struct hsr_port *port, struct list_head *node_db,
206 struct sk_buff *skb, bool is_sup,
207 enum hsr_port_type rx_port)
208{
209 struct hsr_priv *hsr = port->hsr;
210 struct hsr_node *node;
211 struct ethhdr *ethhdr;
212 struct prp_rct *rct;
213 bool san = false;
214 u16 seq_out;
215
216 if (!skb_mac_header_was_set(skb))
217 return NULL;
218
219 ethhdr = (struct ethhdr *)skb_mac_header(skb);
220
221 list_for_each_entry_rcu(node, node_db, mac_list) {
222 if (ether_addr_equal(node->macaddress_A, ethhdr->h_source)) {
223 if (hsr->proto_ops->update_san_info)
224 hsr->proto_ops->update_san_info(node, is_sup);
225 return node;
226 }
227 if (ether_addr_equal(node->macaddress_B, ethhdr->h_source)) {
228 if (hsr->proto_ops->update_san_info)
229 hsr->proto_ops->update_san_info(node, is_sup);
230 return node;
231 }
232 }
233
234 /* Everyone may create a node entry, connected node to a HSR/PRP
235 * device.
236 */
237 if (ethhdr->h_proto == htons(ETH_P_PRP) ||
238 ethhdr->h_proto == htons(ETH_P_HSR)) {
239 /* Use the existing sequence_nr from the tag as starting point
240 * for filtering duplicate frames.
241 */
242 seq_out = hsr_get_skb_sequence_nr(skb) - 1;
243 } else {
244 rct = skb_get_PRP_rct(skb);
245 if (rct && prp_check_lsdu_size(skb, rct, is_sup)) {
246 seq_out = prp_get_skb_sequence_nr(rct);
247 } else {
248 if (rx_port != HSR_PT_MASTER)
249 san = true;
250 seq_out = HSR_SEQNR_START;
251 }
252 }
253
254 return hsr_add_node(hsr, node_db, ethhdr->h_source, seq_out,
255 san, rx_port);
256}
257
258/* Use the Supervision frame's info about an eventual macaddress_B for merging
259 * nodes that has previously had their macaddress_B registered as a separate
260 * node.
261 */
262void hsr_handle_sup_frame(struct hsr_frame_info *frame)
263{
264 struct hsr_node *node_curr = frame->node_src;
265 struct hsr_port *port_rcv = frame->port_rcv;
266 struct hsr_priv *hsr = port_rcv->hsr;
267 struct hsr_sup_payload *hsr_sp;
268 struct hsr_node *node_real;
269 struct sk_buff *skb = NULL;
270 struct list_head *node_db;
271 struct ethhdr *ethhdr;
272 int i;
273
274 /* Here either frame->skb_hsr or frame->skb_prp should be
275 * valid as supervision frame always will have protocol
276 * header info.
277 */
278 if (frame->skb_hsr)
279 skb = frame->skb_hsr;
280 else if (frame->skb_prp)
281 skb = frame->skb_prp;
282 else if (frame->skb_std)
283 skb = frame->skb_std;
284 if (!skb)
285 return;
286
287 ethhdr = (struct ethhdr *)skb_mac_header(skb);
288
289 /* Leave the ethernet header. */
290 skb_pull(skb, sizeof(struct ethhdr));
291
292 /* And leave the HSR tag. */
293 if (ethhdr->h_proto == htons(ETH_P_HSR))
294 skb_pull(skb, sizeof(struct hsr_tag));
295
296 /* And leave the HSR sup tag. */
297 skb_pull(skb, sizeof(struct hsr_sup_tag));
298
299 hsr_sp = (struct hsr_sup_payload *)skb->data;
300
301 /* Merge node_curr (registered on macaddress_B) into node_real */
302 node_db = &port_rcv->hsr->node_db;
303 node_real = find_node_by_addr_A(node_db, hsr_sp->macaddress_A);
304 if (!node_real)
305 /* No frame received from AddrA of this node yet */
306 node_real = hsr_add_node(hsr, node_db, hsr_sp->macaddress_A,
307 HSR_SEQNR_START - 1, true,
308 port_rcv->type);
309 if (!node_real)
310 goto done; /* No mem */
311 if (node_real == node_curr)
312 /* Node has already been merged */
313 goto done;
314
315 ether_addr_copy(node_real->macaddress_B, ethhdr->h_source);
316 for (i = 0; i < HSR_PT_PORTS; i++) {
317 if (!node_curr->time_in_stale[i] &&
318 time_after(node_curr->time_in[i], node_real->time_in[i])) {
319 node_real->time_in[i] = node_curr->time_in[i];
320 node_real->time_in_stale[i] =
321 node_curr->time_in_stale[i];
322 }
323 if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
324 node_real->seq_out[i] = node_curr->seq_out[i];
325 }
326 node_real->addr_B_port = port_rcv->type;
327
328 spin_lock_bh(&hsr->list_lock);
329 list_del_rcu(&node_curr->mac_list);
330 spin_unlock_bh(&hsr->list_lock);
331 kfree_rcu(node_curr, rcu_head);
332
333done:
334 /* PRP uses v0 header */
335 if (ethhdr->h_proto == htons(ETH_P_HSR))
336 skb_push(skb, sizeof(struct hsrv1_ethhdr_sp));
337 else
338 skb_push(skb, sizeof(struct hsrv0_ethhdr_sp));
339}
340
341/* 'skb' is a frame meant for this host, that is to be passed to upper layers.
342 *
343 * If the frame was sent by a node's B interface, replace the source
344 * address with that node's "official" address (macaddress_A) so that upper
345 * layers recognize where it came from.
346 */
347void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb)
348{
349 if (!skb_mac_header_was_set(skb)) {
350 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
351 return;
352 }
353
354 memcpy(ð_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN);
355}
356
357/* 'skb' is a frame meant for another host.
358 * 'port' is the outgoing interface
359 *
360 * Substitute the target (dest) MAC address if necessary, so the it matches the
361 * recipient interface MAC address, regardless of whether that is the
362 * recipient's A or B interface.
363 * This is needed to keep the packets flowing through switches that learn on
364 * which "side" the different interfaces are.
365 */
366void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
367 struct hsr_port *port)
368{
369 struct hsr_node *node_dst;
370
371 if (!skb_mac_header_was_set(skb)) {
372 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
373 return;
374 }
375
376 if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
377 return;
378
379 node_dst = find_node_by_addr_A(&port->hsr->node_db,
380 eth_hdr(skb)->h_dest);
381 if (!node_dst) {
382 if (net_ratelimit())
383 netdev_err(skb->dev, "%s: Unknown node\n", __func__);
384 return;
385 }
386 if (port->type != node_dst->addr_B_port)
387 return;
388
389 if (is_valid_ether_addr(node_dst->macaddress_B))
390 ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B);
391}
392
393void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
394 u16 sequence_nr)
395{
396 /* Don't register incoming frames without a valid sequence number. This
397 * ensures entries of restarted nodes gets pruned so that they can
398 * re-register and resume communications.
399 */
400 if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
401 seq_nr_before(sequence_nr, node->seq_out[port->type]))
402 return;
403
404 node->time_in[port->type] = jiffies;
405 node->time_in_stale[port->type] = false;
406}
407
408/* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
409 * ethhdr->h_source address and skb->mac_header set.
410 *
411 * Return:
412 * 1 if frame can be shown to have been sent recently on this interface,
413 * 0 otherwise, or
414 * negative error code on error
415 */
416int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
417 u16 sequence_nr)
418{
419 if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]) &&
420 time_is_after_jiffies(node->time_out[port->type] +
421 msecs_to_jiffies(HSR_ENTRY_FORGET_TIME)))
422 return 1;
423
424 node->time_out[port->type] = jiffies;
425 node->seq_out[port->type] = sequence_nr;
426 return 0;
427}
428
429static struct hsr_port *get_late_port(struct hsr_priv *hsr,
430 struct hsr_node *node)
431{
432 if (node->time_in_stale[HSR_PT_SLAVE_A])
433 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
434 if (node->time_in_stale[HSR_PT_SLAVE_B])
435 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
436
437 if (time_after(node->time_in[HSR_PT_SLAVE_B],
438 node->time_in[HSR_PT_SLAVE_A] +
439 msecs_to_jiffies(MAX_SLAVE_DIFF)))
440 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
441 if (time_after(node->time_in[HSR_PT_SLAVE_A],
442 node->time_in[HSR_PT_SLAVE_B] +
443 msecs_to_jiffies(MAX_SLAVE_DIFF)))
444 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
445
446 return NULL;
447}
448
449/* Remove stale sequence_nr records. Called by timer every
450 * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
451 */
452void hsr_prune_nodes(struct timer_list *t)
453{
454 struct hsr_priv *hsr = from_timer(hsr, t, prune_timer);
455 struct hsr_node *node;
456 struct hsr_node *tmp;
457 struct hsr_port *port;
458 unsigned long timestamp;
459 unsigned long time_a, time_b;
460
461 spin_lock_bh(&hsr->list_lock);
462 list_for_each_entry_safe(node, tmp, &hsr->node_db, mac_list) {
463 /* Don't prune own node. Neither time_in[HSR_PT_SLAVE_A]
464 * nor time_in[HSR_PT_SLAVE_B], will ever be updated for
465 * the master port. Thus the master node will be repeatedly
466 * pruned leading to packet loss.
467 */
468 if (hsr_addr_is_self(hsr, node->macaddress_A))
469 continue;
470
471 /* Shorthand */
472 time_a = node->time_in[HSR_PT_SLAVE_A];
473 time_b = node->time_in[HSR_PT_SLAVE_B];
474
475 /* Check for timestamps old enough to risk wrap-around */
476 if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET / 2))
477 node->time_in_stale[HSR_PT_SLAVE_A] = true;
478 if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET / 2))
479 node->time_in_stale[HSR_PT_SLAVE_B] = true;
480
481 /* Get age of newest frame from node.
482 * At least one time_in is OK here; nodes get pruned long
483 * before both time_ins can get stale
484 */
485 timestamp = time_a;
486 if (node->time_in_stale[HSR_PT_SLAVE_A] ||
487 (!node->time_in_stale[HSR_PT_SLAVE_B] &&
488 time_after(time_b, time_a)))
489 timestamp = time_b;
490
491 /* Warn of ring error only as long as we get frames at all */
492 if (time_is_after_jiffies(timestamp +
493 msecs_to_jiffies(1.5 * MAX_SLAVE_DIFF))) {
494 rcu_read_lock();
495 port = get_late_port(hsr, node);
496 if (port)
497 hsr_nl_ringerror(hsr, node->macaddress_A, port);
498 rcu_read_unlock();
499 }
500
501 /* Prune old entries */
502 if (time_is_before_jiffies(timestamp +
503 msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
504 hsr_nl_nodedown(hsr, node->macaddress_A);
505 list_del_rcu(&node->mac_list);
506 /* Note that we need to free this entry later: */
507 kfree_rcu(node, rcu_head);
508 }
509 }
510 spin_unlock_bh(&hsr->list_lock);
511
512 /* Restart timer */
513 mod_timer(&hsr->prune_timer,
514 jiffies + msecs_to_jiffies(PRUNE_PERIOD));
515}
516
517void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
518 unsigned char addr[ETH_ALEN])
519{
520 struct hsr_node *node;
521
522 if (!_pos) {
523 node = list_first_or_null_rcu(&hsr->node_db,
524 struct hsr_node, mac_list);
525 if (node)
526 ether_addr_copy(addr, node->macaddress_A);
527 return node;
528 }
529
530 node = _pos;
531 list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
532 ether_addr_copy(addr, node->macaddress_A);
533 return node;
534 }
535
536 return NULL;
537}
538
539int hsr_get_node_data(struct hsr_priv *hsr,
540 const unsigned char *addr,
541 unsigned char addr_b[ETH_ALEN],
542 unsigned int *addr_b_ifindex,
543 int *if1_age,
544 u16 *if1_seq,
545 int *if2_age,
546 u16 *if2_seq)
547{
548 struct hsr_node *node;
549 struct hsr_port *port;
550 unsigned long tdiff;
551
552 node = find_node_by_addr_A(&hsr->node_db, addr);
553 if (!node)
554 return -ENOENT;
555
556 ether_addr_copy(addr_b, node->macaddress_B);
557
558 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
559 if (node->time_in_stale[HSR_PT_SLAVE_A])
560 *if1_age = INT_MAX;
561#if HZ <= MSEC_PER_SEC
562 else if (tdiff > msecs_to_jiffies(INT_MAX))
563 *if1_age = INT_MAX;
564#endif
565 else
566 *if1_age = jiffies_to_msecs(tdiff);
567
568 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
569 if (node->time_in_stale[HSR_PT_SLAVE_B])
570 *if2_age = INT_MAX;
571#if HZ <= MSEC_PER_SEC
572 else if (tdiff > msecs_to_jiffies(INT_MAX))
573 *if2_age = INT_MAX;
574#endif
575 else
576 *if2_age = jiffies_to_msecs(tdiff);
577
578 /* Present sequence numbers as if they were incoming on interface */
579 *if1_seq = node->seq_out[HSR_PT_SLAVE_B];
580 *if2_seq = node->seq_out[HSR_PT_SLAVE_A];
581
582 if (node->addr_B_port != HSR_PT_NONE) {
583 port = hsr_port_get_hsr(hsr, node->addr_B_port);
584 *addr_b_ifindex = port->dev->ifindex;
585 } else {
586 *addr_b_ifindex = -1;
587 }
588
589 return 0;
590}