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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 */
12
13#include <linux/if_ether.h>
14#include <linux/etherdevice.h>
15#include <linux/slab.h>
16#include <linux/rculist.h>
17#include "hsr_main.h"
18#include "hsr_framereg.h"
19#include "hsr_netlink.h"
20
21/* TODO: use hash lists for mac addresses (linux/jhash.h)? */
22
23/* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
24 * false otherwise.
25 */
26static bool seq_nr_after(u16 a, u16 b)
27{
28 /* Remove inconsistency where
29 * seq_nr_after(a, b) == seq_nr_before(a, b)
30 */
31 if ((int)b - a == 32768)
32 return false;
33
34 return (((s16)(b - a)) < 0);
35}
36
37#define seq_nr_before(a, b) seq_nr_after((b), (a))
38#define seq_nr_after_or_eq(a, b) (!seq_nr_before((a), (b)))
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 list_head *self_node_db,
79 unsigned char addr_a[ETH_ALEN],
80 unsigned char addr_b[ETH_ALEN])
81{
82 struct hsr_node *node, *oldnode;
83
84 node = kmalloc(sizeof(*node), GFP_KERNEL);
85 if (!node)
86 return -ENOMEM;
87
88 ether_addr_copy(node->macaddress_A, addr_a);
89 ether_addr_copy(node->macaddress_B, addr_b);
90
91 rcu_read_lock();
92 oldnode = list_first_or_null_rcu(self_node_db,
93 struct hsr_node, mac_list);
94 if (oldnode) {
95 list_replace_rcu(&oldnode->mac_list, &node->mac_list);
96 rcu_read_unlock();
97 synchronize_rcu();
98 kfree(oldnode);
99 } else {
100 rcu_read_unlock();
101 list_add_tail_rcu(&node->mac_list, self_node_db);
102 }
103
104 return 0;
105}
106
107void hsr_del_self_node(struct list_head *self_node_db)
108{
109 struct hsr_node *node;
110
111 rcu_read_lock();
112 node = list_first_or_null_rcu(self_node_db, struct hsr_node, mac_list);
113 rcu_read_unlock();
114 if (node) {
115 list_del_rcu(&node->mac_list);
116 kfree(node);
117 }
118}
119
120void hsr_del_nodes(struct list_head *node_db)
121{
122 struct hsr_node *node;
123 struct hsr_node *tmp;
124
125 list_for_each_entry_safe(node, tmp, node_db, mac_list)
126 kfree(node);
127}
128
129/* Allocate an hsr_node and add it to node_db. 'addr' is the node's address_A;
130 * seq_out is used to initialize filtering of outgoing duplicate frames
131 * originating from the newly added node.
132 */
133struct hsr_node *hsr_add_node(struct list_head *node_db, unsigned char addr[],
134 u16 seq_out)
135{
136 struct hsr_node *node;
137 unsigned long now;
138 int i;
139
140 node = kzalloc(sizeof(*node), GFP_ATOMIC);
141 if (!node)
142 return NULL;
143
144 ether_addr_copy(node->macaddress_A, addr);
145
146 /* We are only interested in time diffs here, so use current jiffies
147 * as initialization. (0 could trigger an spurious ring error warning).
148 */
149 now = jiffies;
150 for (i = 0; i < HSR_PT_PORTS; i++)
151 node->time_in[i] = now;
152 for (i = 0; i < HSR_PT_PORTS; i++)
153 node->seq_out[i] = seq_out;
154
155 list_add_tail_rcu(&node->mac_list, node_db);
156
157 return node;
158}
159
160/* Get the hsr_node from which 'skb' was sent.
161 */
162struct hsr_node *hsr_get_node(struct hsr_port *port, struct sk_buff *skb,
163 bool is_sup)
164{
165 struct list_head *node_db = &port->hsr->node_db;
166 struct hsr_node *node;
167 struct ethhdr *ethhdr;
168 u16 seq_out;
169
170 if (!skb_mac_header_was_set(skb))
171 return NULL;
172
173 ethhdr = (struct ethhdr *)skb_mac_header(skb);
174
175 list_for_each_entry_rcu(node, node_db, mac_list) {
176 if (ether_addr_equal(node->macaddress_A, ethhdr->h_source))
177 return node;
178 if (ether_addr_equal(node->macaddress_B, ethhdr->h_source))
179 return node;
180 }
181
182 /* Everyone may create a node entry, connected node to a HSR device. */
183
184 if (ethhdr->h_proto == htons(ETH_P_PRP) ||
185 ethhdr->h_proto == htons(ETH_P_HSR)) {
186 /* Use the existing sequence_nr from the tag as starting point
187 * for filtering duplicate frames.
188 */
189 seq_out = hsr_get_skb_sequence_nr(skb) - 1;
190 } else {
191 /* this is called also for frames from master port and
192 * so warn only for non master ports
193 */
194 if (port->type != HSR_PT_MASTER)
195 WARN_ONCE(1, "%s: Non-HSR frame\n", __func__);
196 seq_out = HSR_SEQNR_START;
197 }
198
199 return hsr_add_node(node_db, ethhdr->h_source, seq_out);
200}
201
202/* Use the Supervision frame's info about an eventual macaddress_B for merging
203 * nodes that has previously had their macaddress_B registered as a separate
204 * node.
205 */
206void hsr_handle_sup_frame(struct sk_buff *skb, struct hsr_node *node_curr,
207 struct hsr_port *port_rcv)
208{
209 struct ethhdr *ethhdr;
210 struct hsr_node *node_real;
211 struct hsr_sup_payload *hsr_sp;
212 struct list_head *node_db;
213 int i;
214
215 ethhdr = (struct ethhdr *)skb_mac_header(skb);
216
217 /* Leave the ethernet header. */
218 skb_pull(skb, sizeof(struct ethhdr));
219
220 /* And leave the HSR tag. */
221 if (ethhdr->h_proto == htons(ETH_P_HSR))
222 skb_pull(skb, sizeof(struct hsr_tag));
223
224 /* And leave the HSR sup tag. */
225 skb_pull(skb, sizeof(struct hsr_sup_tag));
226
227 hsr_sp = (struct hsr_sup_payload *)skb->data;
228
229 /* Merge node_curr (registered on macaddress_B) into node_real */
230 node_db = &port_rcv->hsr->node_db;
231 node_real = find_node_by_addr_A(node_db, hsr_sp->macaddress_A);
232 if (!node_real)
233 /* No frame received from AddrA of this node yet */
234 node_real = hsr_add_node(node_db, hsr_sp->macaddress_A,
235 HSR_SEQNR_START - 1);
236 if (!node_real)
237 goto done; /* No mem */
238 if (node_real == node_curr)
239 /* Node has already been merged */
240 goto done;
241
242 ether_addr_copy(node_real->macaddress_B, ethhdr->h_source);
243 for (i = 0; i < HSR_PT_PORTS; i++) {
244 if (!node_curr->time_in_stale[i] &&
245 time_after(node_curr->time_in[i], node_real->time_in[i])) {
246 node_real->time_in[i] = node_curr->time_in[i];
247 node_real->time_in_stale[i] =
248 node_curr->time_in_stale[i];
249 }
250 if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
251 node_real->seq_out[i] = node_curr->seq_out[i];
252 }
253 node_real->addr_B_port = port_rcv->type;
254
255 list_del_rcu(&node_curr->mac_list);
256 kfree_rcu(node_curr, rcu_head);
257
258done:
259 skb_push(skb, sizeof(struct hsrv1_ethhdr_sp));
260}
261
262/* 'skb' is a frame meant for this host, that is to be passed to upper layers.
263 *
264 * If the frame was sent by a node's B interface, replace the source
265 * address with that node's "official" address (macaddress_A) so that upper
266 * layers recognize where it came from.
267 */
268void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb)
269{
270 if (!skb_mac_header_was_set(skb)) {
271 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
272 return;
273 }
274
275 memcpy(ð_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN);
276}
277
278/* 'skb' is a frame meant for another host.
279 * 'port' is the outgoing interface
280 *
281 * Substitute the target (dest) MAC address if necessary, so the it matches the
282 * recipient interface MAC address, regardless of whether that is the
283 * recipient's A or B interface.
284 * This is needed to keep the packets flowing through switches that learn on
285 * which "side" the different interfaces are.
286 */
287void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
288 struct hsr_port *port)
289{
290 struct hsr_node *node_dst;
291
292 if (!skb_mac_header_was_set(skb)) {
293 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
294 return;
295 }
296
297 if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
298 return;
299
300 node_dst = find_node_by_addr_A(&port->hsr->node_db,
301 eth_hdr(skb)->h_dest);
302 if (!node_dst) {
303 WARN_ONCE(1, "%s: Unknown node\n", __func__);
304 return;
305 }
306 if (port->type != node_dst->addr_B_port)
307 return;
308
309 ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B);
310}
311
312void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
313 u16 sequence_nr)
314{
315 /* Don't register incoming frames without a valid sequence number. This
316 * ensures entries of restarted nodes gets pruned so that they can
317 * re-register and resume communications.
318 */
319 if (seq_nr_before(sequence_nr, node->seq_out[port->type]))
320 return;
321
322 node->time_in[port->type] = jiffies;
323 node->time_in_stale[port->type] = false;
324}
325
326/* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
327 * ethhdr->h_source address and skb->mac_header set.
328 *
329 * Return:
330 * 1 if frame can be shown to have been sent recently on this interface,
331 * 0 otherwise, or
332 * negative error code on error
333 */
334int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
335 u16 sequence_nr)
336{
337 if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]))
338 return 1;
339
340 node->seq_out[port->type] = sequence_nr;
341 return 0;
342}
343
344static struct hsr_port *get_late_port(struct hsr_priv *hsr,
345 struct hsr_node *node)
346{
347 if (node->time_in_stale[HSR_PT_SLAVE_A])
348 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
349 if (node->time_in_stale[HSR_PT_SLAVE_B])
350 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
351
352 if (time_after(node->time_in[HSR_PT_SLAVE_B],
353 node->time_in[HSR_PT_SLAVE_A] +
354 msecs_to_jiffies(MAX_SLAVE_DIFF)))
355 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
356 if (time_after(node->time_in[HSR_PT_SLAVE_A],
357 node->time_in[HSR_PT_SLAVE_B] +
358 msecs_to_jiffies(MAX_SLAVE_DIFF)))
359 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
360
361 return NULL;
362}
363
364/* Remove stale sequence_nr records. Called by timer every
365 * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
366 */
367void hsr_prune_nodes(struct timer_list *t)
368{
369 struct hsr_priv *hsr = from_timer(hsr, t, prune_timer);
370 struct hsr_node *node;
371 struct hsr_port *port;
372 unsigned long timestamp;
373 unsigned long time_a, time_b;
374
375 rcu_read_lock();
376 list_for_each_entry_rcu(node, &hsr->node_db, mac_list) {
377 /* Don't prune own node. Neither time_in[HSR_PT_SLAVE_A]
378 * nor time_in[HSR_PT_SLAVE_B], will ever be updated for
379 * the master port. Thus the master node will be repeatedly
380 * pruned leading to packet loss.
381 */
382 if (hsr_addr_is_self(hsr, node->macaddress_A))
383 continue;
384
385 /* Shorthand */
386 time_a = node->time_in[HSR_PT_SLAVE_A];
387 time_b = node->time_in[HSR_PT_SLAVE_B];
388
389 /* Check for timestamps old enough to risk wrap-around */
390 if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET / 2))
391 node->time_in_stale[HSR_PT_SLAVE_A] = true;
392 if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET / 2))
393 node->time_in_stale[HSR_PT_SLAVE_B] = true;
394
395 /* Get age of newest frame from node.
396 * At least one time_in is OK here; nodes get pruned long
397 * before both time_ins can get stale
398 */
399 timestamp = time_a;
400 if (node->time_in_stale[HSR_PT_SLAVE_A] ||
401 (!node->time_in_stale[HSR_PT_SLAVE_B] &&
402 time_after(time_b, time_a)))
403 timestamp = time_b;
404
405 /* Warn of ring error only as long as we get frames at all */
406 if (time_is_after_jiffies(timestamp +
407 msecs_to_jiffies(1.5 * MAX_SLAVE_DIFF))) {
408 rcu_read_lock();
409 port = get_late_port(hsr, node);
410 if (port)
411 hsr_nl_ringerror(hsr, node->macaddress_A, port);
412 rcu_read_unlock();
413 }
414
415 /* Prune old entries */
416 if (time_is_before_jiffies(timestamp +
417 msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
418 hsr_nl_nodedown(hsr, node->macaddress_A);
419 list_del_rcu(&node->mac_list);
420 /* Note that we need to free this entry later: */
421 kfree_rcu(node, rcu_head);
422 }
423 }
424 rcu_read_unlock();
425
426 /* Restart timer */
427 mod_timer(&hsr->prune_timer,
428 jiffies + msecs_to_jiffies(PRUNE_PERIOD));
429}
430
431void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
432 unsigned char addr[ETH_ALEN])
433{
434 struct hsr_node *node;
435
436 if (!_pos) {
437 node = list_first_or_null_rcu(&hsr->node_db,
438 struct hsr_node, mac_list);
439 if (node)
440 ether_addr_copy(addr, node->macaddress_A);
441 return node;
442 }
443
444 node = _pos;
445 list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
446 ether_addr_copy(addr, node->macaddress_A);
447 return node;
448 }
449
450 return NULL;
451}
452
453int hsr_get_node_data(struct hsr_priv *hsr,
454 const unsigned char *addr,
455 unsigned char addr_b[ETH_ALEN],
456 unsigned int *addr_b_ifindex,
457 int *if1_age,
458 u16 *if1_seq,
459 int *if2_age,
460 u16 *if2_seq)
461{
462 struct hsr_node *node;
463 struct hsr_port *port;
464 unsigned long tdiff;
465
466 rcu_read_lock();
467 node = find_node_by_addr_A(&hsr->node_db, addr);
468 if (!node) {
469 rcu_read_unlock();
470 return -ENOENT; /* No such entry */
471 }
472
473 ether_addr_copy(addr_b, node->macaddress_B);
474
475 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
476 if (node->time_in_stale[HSR_PT_SLAVE_A])
477 *if1_age = INT_MAX;
478#if HZ <= MSEC_PER_SEC
479 else if (tdiff > msecs_to_jiffies(INT_MAX))
480 *if1_age = INT_MAX;
481#endif
482 else
483 *if1_age = jiffies_to_msecs(tdiff);
484
485 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
486 if (node->time_in_stale[HSR_PT_SLAVE_B])
487 *if2_age = INT_MAX;
488#if HZ <= MSEC_PER_SEC
489 else if (tdiff > msecs_to_jiffies(INT_MAX))
490 *if2_age = INT_MAX;
491#endif
492 else
493 *if2_age = jiffies_to_msecs(tdiff);
494
495 /* Present sequence numbers as if they were incoming on interface */
496 *if1_seq = node->seq_out[HSR_PT_SLAVE_B];
497 *if2_seq = node->seq_out[HSR_PT_SLAVE_A];
498
499 if (node->addr_B_port != HSR_PT_NONE) {
500 port = hsr_port_get_hsr(hsr, node->addr_B_port);
501 *addr_b_ifindex = port->dev->ifindex;
502 } else {
503 *addr_b_ifindex = -1;
504 }
505
506 rcu_read_unlock();
507
508 return 0;
509}
1/* Copyright 2011-2014 Autronica Fire and Security AS
2 *
3 * This program is free software; you can redistribute it and/or modify it
4 * under the terms of the GNU General Public License as published by the Free
5 * Software Foundation; either version 2 of the License, or (at your option)
6 * any later version.
7 *
8 * Author(s):
9 * 2011-2014 Arvid Brodin, arvid.brodin@alten.se
10 *
11 * 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 hsr_node {
27 struct list_head mac_list;
28 unsigned char MacAddressA[ETH_ALEN];
29 unsigned char MacAddressB[ETH_ALEN];
30 /* Local slave through which AddrB frames are received from this node */
31 enum hsr_port_type AddrB_port;
32 unsigned long time_in[HSR_PT_PORTS];
33 bool time_in_stale[HSR_PT_PORTS];
34 u16 seq_out[HSR_PT_PORTS];
35 struct rcu_head rcu_head;
36};
37
38
39/* TODO: use hash lists for mac addresses (linux/jhash.h)? */
40
41
42/* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
43 * false otherwise.
44 */
45static bool seq_nr_after(u16 a, u16 b)
46{
47 /* Remove inconsistency where
48 * seq_nr_after(a, b) == seq_nr_before(a, b)
49 */
50 if ((int) b - a == 32768)
51 return false;
52
53 return (((s16) (b - a)) < 0);
54}
55#define seq_nr_before(a, b) seq_nr_after((b), (a))
56#define seq_nr_after_or_eq(a, b) (!seq_nr_before((a), (b)))
57#define seq_nr_before_or_eq(a, b) (!seq_nr_after((a), (b)))
58
59
60bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr)
61{
62 struct hsr_node *node;
63
64 node = list_first_or_null_rcu(&hsr->self_node_db, struct hsr_node,
65 mac_list);
66 if (!node) {
67 WARN_ONCE(1, "HSR: No self node\n");
68 return false;
69 }
70
71 if (ether_addr_equal(addr, node->MacAddressA))
72 return true;
73 if (ether_addr_equal(addr, node->MacAddressB))
74 return true;
75
76 return false;
77}
78
79/* Search for mac entry. Caller must hold rcu read lock.
80 */
81static struct hsr_node *find_node_by_AddrA(struct list_head *node_db,
82 const unsigned char addr[ETH_ALEN])
83{
84 struct hsr_node *node;
85
86 list_for_each_entry_rcu(node, node_db, mac_list) {
87 if (ether_addr_equal(node->MacAddressA, addr))
88 return node;
89 }
90
91 return NULL;
92}
93
94
95/* Helper for device init; the self_node_db is used in hsr_rcv() to recognize
96 * frames from self that's been looped over the HSR ring.
97 */
98int hsr_create_self_node(struct list_head *self_node_db,
99 unsigned char addr_a[ETH_ALEN],
100 unsigned char addr_b[ETH_ALEN])
101{
102 struct hsr_node *node, *oldnode;
103
104 node = kmalloc(sizeof(*node), GFP_KERNEL);
105 if (!node)
106 return -ENOMEM;
107
108 ether_addr_copy(node->MacAddressA, addr_a);
109 ether_addr_copy(node->MacAddressB, addr_b);
110
111 rcu_read_lock();
112 oldnode = list_first_or_null_rcu(self_node_db,
113 struct hsr_node, mac_list);
114 if (oldnode) {
115 list_replace_rcu(&oldnode->mac_list, &node->mac_list);
116 rcu_read_unlock();
117 synchronize_rcu();
118 kfree(oldnode);
119 } else {
120 rcu_read_unlock();
121 list_add_tail_rcu(&node->mac_list, self_node_db);
122 }
123
124 return 0;
125}
126
127
128/* Allocate an hsr_node and add it to node_db. 'addr' is the node's AddressA;
129 * seq_out is used to initialize filtering of outgoing duplicate frames
130 * originating from the newly added node.
131 */
132struct hsr_node *hsr_add_node(struct list_head *node_db, unsigned char addr[],
133 u16 seq_out)
134{
135 struct hsr_node *node;
136 unsigned long now;
137 int i;
138
139 node = kzalloc(sizeof(*node), GFP_ATOMIC);
140 if (!node)
141 return NULL;
142
143 ether_addr_copy(node->MacAddressA, addr);
144
145 /* We are only interested in time diffs here, so use current jiffies
146 * as initialization. (0 could trigger an spurious ring error warning).
147 */
148 now = jiffies;
149 for (i = 0; i < HSR_PT_PORTS; i++)
150 node->time_in[i] = now;
151 for (i = 0; i < HSR_PT_PORTS; i++)
152 node->seq_out[i] = seq_out;
153
154 list_add_tail_rcu(&node->mac_list, node_db);
155
156 return node;
157}
158
159/* Get the hsr_node from which 'skb' was sent.
160 */
161struct hsr_node *hsr_get_node(struct list_head *node_db, struct sk_buff *skb,
162 bool is_sup)
163{
164 struct hsr_node *node;
165 struct ethhdr *ethhdr;
166 u16 seq_out;
167
168 if (!skb_mac_header_was_set(skb))
169 return NULL;
170
171 ethhdr = (struct ethhdr *) skb_mac_header(skb);
172
173 list_for_each_entry_rcu(node, node_db, mac_list) {
174 if (ether_addr_equal(node->MacAddressA, ethhdr->h_source))
175 return node;
176 if (ether_addr_equal(node->MacAddressB, ethhdr->h_source))
177 return node;
178 }
179
180 /* Everyone may create a node entry, connected node to a HSR device. */
181
182 if (ethhdr->h_proto == htons(ETH_P_PRP)
183 || ethhdr->h_proto == htons(ETH_P_HSR)) {
184 /* Use the existing sequence_nr from the tag as starting point
185 * for filtering duplicate frames.
186 */
187 seq_out = hsr_get_skb_sequence_nr(skb) - 1;
188 } else {
189 WARN_ONCE(1, "%s: Non-HSR frame\n", __func__);
190 seq_out = HSR_SEQNR_START;
191 }
192
193 return hsr_add_node(node_db, ethhdr->h_source, seq_out);
194}
195
196/* Use the Supervision frame's info about an eventual MacAddressB for merging
197 * nodes that has previously had their MacAddressB registered as a separate
198 * node.
199 */
200void hsr_handle_sup_frame(struct sk_buff *skb, struct hsr_node *node_curr,
201 struct hsr_port *port_rcv)
202{
203 struct ethhdr *ethhdr;
204 struct hsr_node *node_real;
205 struct hsr_sup_payload *hsr_sp;
206 struct list_head *node_db;
207 int i;
208
209 ethhdr = (struct ethhdr *) skb_mac_header(skb);
210
211 /* Leave the ethernet header. */
212 skb_pull(skb, sizeof(struct ethhdr));
213
214 /* And leave the HSR tag. */
215 if (ethhdr->h_proto == htons(ETH_P_HSR))
216 skb_pull(skb, sizeof(struct hsr_tag));
217
218 /* And leave the HSR sup tag. */
219 skb_pull(skb, sizeof(struct hsr_sup_tag));
220
221 hsr_sp = (struct hsr_sup_payload *) skb->data;
222
223 /* Merge node_curr (registered on MacAddressB) into node_real */
224 node_db = &port_rcv->hsr->node_db;
225 node_real = find_node_by_AddrA(node_db, hsr_sp->MacAddressA);
226 if (!node_real)
227 /* No frame received from AddrA of this node yet */
228 node_real = hsr_add_node(node_db, hsr_sp->MacAddressA,
229 HSR_SEQNR_START - 1);
230 if (!node_real)
231 goto done; /* No mem */
232 if (node_real == node_curr)
233 /* Node has already been merged */
234 goto done;
235
236 ether_addr_copy(node_real->MacAddressB, ethhdr->h_source);
237 for (i = 0; i < HSR_PT_PORTS; i++) {
238 if (!node_curr->time_in_stale[i] &&
239 time_after(node_curr->time_in[i], node_real->time_in[i])) {
240 node_real->time_in[i] = node_curr->time_in[i];
241 node_real->time_in_stale[i] = node_curr->time_in_stale[i];
242 }
243 if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
244 node_real->seq_out[i] = node_curr->seq_out[i];
245 }
246 node_real->AddrB_port = port_rcv->type;
247
248 list_del_rcu(&node_curr->mac_list);
249 kfree_rcu(node_curr, rcu_head);
250
251done:
252 skb_push(skb, sizeof(struct hsrv1_ethhdr_sp));
253}
254
255
256/* 'skb' is a frame meant for this host, that is to be passed to upper layers.
257 *
258 * If the frame was sent by a node's B interface, replace the source
259 * address with that node's "official" address (MacAddressA) so that upper
260 * layers recognize where it came from.
261 */
262void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb)
263{
264 if (!skb_mac_header_was_set(skb)) {
265 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
266 return;
267 }
268
269 memcpy(ð_hdr(skb)->h_source, node->MacAddressA, ETH_ALEN);
270}
271
272/* 'skb' is a frame meant for another host.
273 * 'port' is the outgoing interface
274 *
275 * Substitute the target (dest) MAC address if necessary, so the it matches the
276 * recipient interface MAC address, regardless of whether that is the
277 * recipient's A or B interface.
278 * This is needed to keep the packets flowing through switches that learn on
279 * which "side" the different interfaces are.
280 */
281void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
282 struct hsr_port *port)
283{
284 struct hsr_node *node_dst;
285
286 if (!skb_mac_header_was_set(skb)) {
287 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
288 return;
289 }
290
291 if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
292 return;
293
294 node_dst = find_node_by_AddrA(&port->hsr->node_db, eth_hdr(skb)->h_dest);
295 if (!node_dst) {
296 WARN_ONCE(1, "%s: Unknown node\n", __func__);
297 return;
298 }
299 if (port->type != node_dst->AddrB_port)
300 return;
301
302 ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->MacAddressB);
303}
304
305
306void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
307 u16 sequence_nr)
308{
309 /* Don't register incoming frames without a valid sequence number. This
310 * ensures entries of restarted nodes gets pruned so that they can
311 * re-register and resume communications.
312 */
313 if (seq_nr_before(sequence_nr, node->seq_out[port->type]))
314 return;
315
316 node->time_in[port->type] = jiffies;
317 node->time_in_stale[port->type] = false;
318}
319
320/* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
321 * ethhdr->h_source address and skb->mac_header set.
322 *
323 * Return:
324 * 1 if frame can be shown to have been sent recently on this interface,
325 * 0 otherwise, or
326 * negative error code on error
327 */
328int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
329 u16 sequence_nr)
330{
331 if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]))
332 return 1;
333
334 node->seq_out[port->type] = sequence_nr;
335 return 0;
336}
337
338
339static struct hsr_port *get_late_port(struct hsr_priv *hsr,
340 struct hsr_node *node)
341{
342 if (node->time_in_stale[HSR_PT_SLAVE_A])
343 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
344 if (node->time_in_stale[HSR_PT_SLAVE_B])
345 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
346
347 if (time_after(node->time_in[HSR_PT_SLAVE_B],
348 node->time_in[HSR_PT_SLAVE_A] +
349 msecs_to_jiffies(MAX_SLAVE_DIFF)))
350 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
351 if (time_after(node->time_in[HSR_PT_SLAVE_A],
352 node->time_in[HSR_PT_SLAVE_B] +
353 msecs_to_jiffies(MAX_SLAVE_DIFF)))
354 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
355
356 return NULL;
357}
358
359
360/* Remove stale sequence_nr records. Called by timer every
361 * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
362 */
363void hsr_prune_nodes(unsigned long data)
364{
365 struct hsr_priv *hsr;
366 struct hsr_node *node;
367 struct hsr_port *port;
368 unsigned long timestamp;
369 unsigned long time_a, time_b;
370
371 hsr = (struct hsr_priv *) data;
372
373 rcu_read_lock();
374 list_for_each_entry_rcu(node, &hsr->node_db, mac_list) {
375 /* Shorthand */
376 time_a = node->time_in[HSR_PT_SLAVE_A];
377 time_b = node->time_in[HSR_PT_SLAVE_B];
378
379 /* Check for timestamps old enough to risk wrap-around */
380 if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET/2))
381 node->time_in_stale[HSR_PT_SLAVE_A] = true;
382 if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET/2))
383 node->time_in_stale[HSR_PT_SLAVE_B] = true;
384
385 /* Get age of newest frame from node.
386 * At least one time_in is OK here; nodes get pruned long
387 * before both time_ins can get stale
388 */
389 timestamp = time_a;
390 if (node->time_in_stale[HSR_PT_SLAVE_A] ||
391 (!node->time_in_stale[HSR_PT_SLAVE_B] &&
392 time_after(time_b, time_a)))
393 timestamp = time_b;
394
395 /* Warn of ring error only as long as we get frames at all */
396 if (time_is_after_jiffies(timestamp +
397 msecs_to_jiffies(1.5*MAX_SLAVE_DIFF))) {
398 rcu_read_lock();
399 port = get_late_port(hsr, node);
400 if (port != NULL)
401 hsr_nl_ringerror(hsr, node->MacAddressA, port);
402 rcu_read_unlock();
403 }
404
405 /* Prune old entries */
406 if (time_is_before_jiffies(timestamp +
407 msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
408 hsr_nl_nodedown(hsr, node->MacAddressA);
409 list_del_rcu(&node->mac_list);
410 /* Note that we need to free this entry later: */
411 kfree_rcu(node, rcu_head);
412 }
413 }
414 rcu_read_unlock();
415}
416
417
418void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
419 unsigned char addr[ETH_ALEN])
420{
421 struct hsr_node *node;
422
423 if (!_pos) {
424 node = list_first_or_null_rcu(&hsr->node_db,
425 struct hsr_node, mac_list);
426 if (node)
427 ether_addr_copy(addr, node->MacAddressA);
428 return node;
429 }
430
431 node = _pos;
432 list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
433 ether_addr_copy(addr, node->MacAddressA);
434 return node;
435 }
436
437 return NULL;
438}
439
440
441int hsr_get_node_data(struct hsr_priv *hsr,
442 const unsigned char *addr,
443 unsigned char addr_b[ETH_ALEN],
444 unsigned int *addr_b_ifindex,
445 int *if1_age,
446 u16 *if1_seq,
447 int *if2_age,
448 u16 *if2_seq)
449{
450 struct hsr_node *node;
451 struct hsr_port *port;
452 unsigned long tdiff;
453
454
455 rcu_read_lock();
456 node = find_node_by_AddrA(&hsr->node_db, addr);
457 if (!node) {
458 rcu_read_unlock();
459 return -ENOENT; /* No such entry */
460 }
461
462 ether_addr_copy(addr_b, node->MacAddressB);
463
464 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
465 if (node->time_in_stale[HSR_PT_SLAVE_A])
466 *if1_age = INT_MAX;
467#if HZ <= MSEC_PER_SEC
468 else if (tdiff > msecs_to_jiffies(INT_MAX))
469 *if1_age = INT_MAX;
470#endif
471 else
472 *if1_age = jiffies_to_msecs(tdiff);
473
474 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
475 if (node->time_in_stale[HSR_PT_SLAVE_B])
476 *if2_age = INT_MAX;
477#if HZ <= MSEC_PER_SEC
478 else if (tdiff > msecs_to_jiffies(INT_MAX))
479 *if2_age = INT_MAX;
480#endif
481 else
482 *if2_age = jiffies_to_msecs(tdiff);
483
484 /* Present sequence numbers as if they were incoming on interface */
485 *if1_seq = node->seq_out[HSR_PT_SLAVE_B];
486 *if2_seq = node->seq_out[HSR_PT_SLAVE_A];
487
488 if (node->AddrB_port != HSR_PT_NONE) {
489 port = hsr_port_get_hsr(hsr, node->AddrB_port);
490 *addr_b_ifindex = port->dev->ifindex;
491 } else {
492 *addr_b_ifindex = -1;
493 }
494
495 rcu_read_unlock();
496
497 return 0;
498}