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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/* 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}
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}