1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright 2011-2014 Autronica Fire and Security AS
5 * 2011-2014 Arvid Brodin, arvid.brodin@alten.se
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.
14 #include <linux/if_ether.h>
15 #include <linux/etherdevice.h>
16 #include <linux/slab.h>
17 #include <linux/rculist.h>
19 #include "hsr_framereg.h"
20 #include "hsr_netlink.h"
22 /* TODO: use hash lists for mac addresses (linux/jhash.h)? */
24 /* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
27 static bool seq_nr_after(u16 a, u16 b)
29 /* Remove inconsistency where
30 * seq_nr_after(a, b) == seq_nr_before(a, b)
32 if ((int)b - a == 32768)
35 return (((s16)(b - a)) < 0);
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)))
41 bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr)
43 struct hsr_node *node;
45 node = list_first_or_null_rcu(&hsr->self_node_db, struct hsr_node,
48 WARN_ONCE(1, "HSR: No self node\n");
52 if (ether_addr_equal(addr, node->macaddress_A))
54 if (ether_addr_equal(addr, node->macaddress_B))
60 /* Search for mac entry. Caller must hold rcu read lock.
62 static struct hsr_node *find_node_by_addr_A(struct list_head *node_db,
63 const unsigned char addr[ETH_ALEN])
65 struct hsr_node *node;
67 list_for_each_entry_rcu(node, node_db, mac_list) {
68 if (ether_addr_equal(node->macaddress_A, addr))
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.
78 int hsr_create_self_node(struct hsr_priv *hsr,
79 unsigned char addr_a[ETH_ALEN],
80 unsigned char addr_b[ETH_ALEN])
82 struct list_head *self_node_db = &hsr->self_node_db;
83 struct hsr_node *node, *oldnode;
85 node = kmalloc(sizeof(*node), GFP_KERNEL);
89 ether_addr_copy(node->macaddress_A, addr_a);
90 ether_addr_copy(node->macaddress_B, addr_b);
92 spin_lock_bh(&hsr->list_lock);
93 oldnode = list_first_or_null_rcu(self_node_db,
94 struct hsr_node, mac_list);
96 list_replace_rcu(&oldnode->mac_list, &node->mac_list);
97 spin_unlock_bh(&hsr->list_lock);
98 kfree_rcu(oldnode, rcu_head);
100 list_add_tail_rcu(&node->mac_list, self_node_db);
101 spin_unlock_bh(&hsr->list_lock);
107 void hsr_del_self_node(struct hsr_priv *hsr)
109 struct list_head *self_node_db = &hsr->self_node_db;
110 struct hsr_node *node;
112 spin_lock_bh(&hsr->list_lock);
113 node = list_first_or_null_rcu(self_node_db, struct hsr_node, mac_list);
115 list_del_rcu(&node->mac_list);
116 kfree_rcu(node, rcu_head);
118 spin_unlock_bh(&hsr->list_lock);
121 void hsr_del_nodes(struct list_head *node_db)
123 struct hsr_node *node;
124 struct hsr_node *tmp;
126 list_for_each_entry_safe(node, tmp, node_db, mac_list)
130 void prp_handle_san_frame(bool san, enum hsr_port_type port,
131 struct hsr_node *node)
133 /* Mark if the SAN node is over LAN_A or LAN_B */
134 if (port == HSR_PT_SLAVE_A) {
139 if (port == HSR_PT_SLAVE_B)
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.
147 static 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)
153 struct hsr_node *new_node, *node;
157 new_node = kzalloc(sizeof(*new_node), GFP_ATOMIC);
161 ether_addr_copy(new_node->macaddress_A, addr);
163 /* We are only interested in time diffs here, so use current jiffies
164 * as initialization. (0 could trigger an spurious ring error warning).
167 for (i = 0; i < HSR_PT_PORTS; i++) {
168 new_node->time_in[i] = now;
169 new_node->time_out[i] = now;
171 for (i = 0; i < HSR_PT_PORTS; i++)
172 new_node->seq_out[i] = seq_out;
174 if (san && hsr->proto_ops->handle_san_frame)
175 hsr->proto_ops->handle_san_frame(san, rx_port, new_node);
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))
182 if (ether_addr_equal(node->macaddress_B, addr))
185 list_add_tail_rcu(&new_node->mac_list, node_db);
186 spin_unlock_bh(&hsr->list_lock);
189 spin_unlock_bh(&hsr->list_lock);
194 void prp_update_san_info(struct hsr_node *node, bool is_sup)
203 /* Get the hsr_node from which 'skb' was sent.
205 struct 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)
209 struct hsr_priv *hsr = port->hsr;
210 struct hsr_node *node;
211 struct ethhdr *ethhdr;
216 if (!skb_mac_header_was_set(skb))
219 ethhdr = (struct ethhdr *)skb_mac_header(skb);
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);
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);
234 /* Everyone may create a node entry, connected node to a HSR/PRP
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.
242 seq_out = hsr_get_skb_sequence_nr(skb) - 1;
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);
248 if (rx_port != HSR_PT_MASTER)
250 seq_out = HSR_SEQNR_START;
254 return hsr_add_node(hsr, node_db, ethhdr->h_source, seq_out,
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
262 void hsr_handle_sup_frame(struct hsr_frame_info *frame)
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;
274 /* Here either frame->skb_hsr or frame->skb_prp should be
275 * valid as supervision frame always will have protocol
279 skb = frame->skb_hsr;
280 else if (frame->skb_prp)
281 skb = frame->skb_prp;
285 ethhdr = (struct ethhdr *)skb_mac_header(skb);
287 /* Leave the ethernet header. */
288 skb_pull(skb, sizeof(struct ethhdr));
290 /* And leave the HSR tag. */
291 if (ethhdr->h_proto == htons(ETH_P_HSR))
292 skb_pull(skb, sizeof(struct hsr_tag));
294 /* And leave the HSR sup tag. */
295 skb_pull(skb, sizeof(struct hsr_sup_tag));
297 hsr_sp = (struct hsr_sup_payload *)skb->data;
299 /* Merge node_curr (registered on macaddress_B) into node_real */
300 node_db = &port_rcv->hsr->node_db;
301 node_real = find_node_by_addr_A(node_db, hsr_sp->macaddress_A);
303 /* No frame received from AddrA of this node yet */
304 node_real = hsr_add_node(hsr, node_db, hsr_sp->macaddress_A,
305 HSR_SEQNR_START - 1, true,
308 goto done; /* No mem */
309 if (node_real == node_curr)
310 /* Node has already been merged */
313 ether_addr_copy(node_real->macaddress_B, ethhdr->h_source);
314 for (i = 0; i < HSR_PT_PORTS; i++) {
315 if (!node_curr->time_in_stale[i] &&
316 time_after(node_curr->time_in[i], node_real->time_in[i])) {
317 node_real->time_in[i] = node_curr->time_in[i];
318 node_real->time_in_stale[i] =
319 node_curr->time_in_stale[i];
321 if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
322 node_real->seq_out[i] = node_curr->seq_out[i];
324 node_real->addr_B_port = port_rcv->type;
326 spin_lock_bh(&hsr->list_lock);
327 list_del_rcu(&node_curr->mac_list);
328 spin_unlock_bh(&hsr->list_lock);
329 kfree_rcu(node_curr, rcu_head);
332 /* PRP uses v0 header */
333 if (ethhdr->h_proto == htons(ETH_P_HSR))
334 skb_push(skb, sizeof(struct hsrv1_ethhdr_sp));
336 skb_push(skb, sizeof(struct hsrv0_ethhdr_sp));
339 /* 'skb' is a frame meant for this host, that is to be passed to upper layers.
341 * If the frame was sent by a node's B interface, replace the source
342 * address with that node's "official" address (macaddress_A) so that upper
343 * layers recognize where it came from.
345 void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb)
347 if (!skb_mac_header_was_set(skb)) {
348 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
352 memcpy(ð_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN);
355 /* 'skb' is a frame meant for another host.
356 * 'port' is the outgoing interface
358 * Substitute the target (dest) MAC address if necessary, so the it matches the
359 * recipient interface MAC address, regardless of whether that is the
360 * recipient's A or B interface.
361 * This is needed to keep the packets flowing through switches that learn on
362 * which "side" the different interfaces are.
364 void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
365 struct hsr_port *port)
367 struct hsr_node *node_dst;
369 if (!skb_mac_header_was_set(skb)) {
370 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
374 if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
377 node_dst = find_node_by_addr_A(&port->hsr->node_db,
378 eth_hdr(skb)->h_dest);
381 netdev_err(skb->dev, "%s: Unknown node\n", __func__);
384 if (port->type != node_dst->addr_B_port)
387 if (is_valid_ether_addr(node_dst->macaddress_B))
388 ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B);
391 void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
394 /* Don't register incoming frames without a valid sequence number. This
395 * ensures entries of restarted nodes gets pruned so that they can
396 * re-register and resume communications.
398 if (seq_nr_before(sequence_nr, node->seq_out[port->type]))
401 node->time_in[port->type] = jiffies;
402 node->time_in_stale[port->type] = false;
405 /* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
406 * ethhdr->h_source address and skb->mac_header set.
409 * 1 if frame can be shown to have been sent recently on this interface,
411 * negative error code on error
413 int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
416 if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]) &&
417 time_is_after_jiffies(node->time_out[port->type] +
418 msecs_to_jiffies(HSR_ENTRY_FORGET_TIME)))
421 node->time_out[port->type] = jiffies;
422 node->seq_out[port->type] = sequence_nr;
426 static struct hsr_port *get_late_port(struct hsr_priv *hsr,
427 struct hsr_node *node)
429 if (node->time_in_stale[HSR_PT_SLAVE_A])
430 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
431 if (node->time_in_stale[HSR_PT_SLAVE_B])
432 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
434 if (time_after(node->time_in[HSR_PT_SLAVE_B],
435 node->time_in[HSR_PT_SLAVE_A] +
436 msecs_to_jiffies(MAX_SLAVE_DIFF)))
437 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
438 if (time_after(node->time_in[HSR_PT_SLAVE_A],
439 node->time_in[HSR_PT_SLAVE_B] +
440 msecs_to_jiffies(MAX_SLAVE_DIFF)))
441 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
446 /* Remove stale sequence_nr records. Called by timer every
447 * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
449 void hsr_prune_nodes(struct timer_list *t)
451 struct hsr_priv *hsr = from_timer(hsr, t, prune_timer);
452 struct hsr_node *node;
453 struct hsr_node *tmp;
454 struct hsr_port *port;
455 unsigned long timestamp;
456 unsigned long time_a, time_b;
458 spin_lock_bh(&hsr->list_lock);
459 list_for_each_entry_safe(node, tmp, &hsr->node_db, mac_list) {
460 /* Don't prune own node. Neither time_in[HSR_PT_SLAVE_A]
461 * nor time_in[HSR_PT_SLAVE_B], will ever be updated for
462 * the master port. Thus the master node will be repeatedly
463 * pruned leading to packet loss.
465 if (hsr_addr_is_self(hsr, node->macaddress_A))
469 time_a = node->time_in[HSR_PT_SLAVE_A];
470 time_b = node->time_in[HSR_PT_SLAVE_B];
472 /* Check for timestamps old enough to risk wrap-around */
473 if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET / 2))
474 node->time_in_stale[HSR_PT_SLAVE_A] = true;
475 if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET / 2))
476 node->time_in_stale[HSR_PT_SLAVE_B] = true;
478 /* Get age of newest frame from node.
479 * At least one time_in is OK here; nodes get pruned long
480 * before both time_ins can get stale
483 if (node->time_in_stale[HSR_PT_SLAVE_A] ||
484 (!node->time_in_stale[HSR_PT_SLAVE_B] &&
485 time_after(time_b, time_a)))
488 /* Warn of ring error only as long as we get frames at all */
489 if (time_is_after_jiffies(timestamp +
490 msecs_to_jiffies(1.5 * MAX_SLAVE_DIFF))) {
492 port = get_late_port(hsr, node);
494 hsr_nl_ringerror(hsr, node->macaddress_A, port);
498 /* Prune old entries */
499 if (time_is_before_jiffies(timestamp +
500 msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
501 hsr_nl_nodedown(hsr, node->macaddress_A);
502 list_del_rcu(&node->mac_list);
503 /* Note that we need to free this entry later: */
504 kfree_rcu(node, rcu_head);
507 spin_unlock_bh(&hsr->list_lock);
510 mod_timer(&hsr->prune_timer,
511 jiffies + msecs_to_jiffies(PRUNE_PERIOD));
514 void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
515 unsigned char addr[ETH_ALEN])
517 struct hsr_node *node;
520 node = list_first_or_null_rcu(&hsr->node_db,
521 struct hsr_node, mac_list);
523 ether_addr_copy(addr, node->macaddress_A);
528 list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
529 ether_addr_copy(addr, node->macaddress_A);
536 int hsr_get_node_data(struct hsr_priv *hsr,
537 const unsigned char *addr,
538 unsigned char addr_b[ETH_ALEN],
539 unsigned int *addr_b_ifindex,
545 struct hsr_node *node;
546 struct hsr_port *port;
549 node = find_node_by_addr_A(&hsr->node_db, addr);
553 ether_addr_copy(addr_b, node->macaddress_B);
555 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
556 if (node->time_in_stale[HSR_PT_SLAVE_A])
558 #if HZ <= MSEC_PER_SEC
559 else if (tdiff > msecs_to_jiffies(INT_MAX))
563 *if1_age = jiffies_to_msecs(tdiff);
565 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
566 if (node->time_in_stale[HSR_PT_SLAVE_B])
568 #if HZ <= MSEC_PER_SEC
569 else if (tdiff > msecs_to_jiffies(INT_MAX))
573 *if2_age = jiffies_to_msecs(tdiff);
575 /* Present sequence numbers as if they were incoming on interface */
576 *if1_seq = node->seq_out[HSR_PT_SLAVE_B];
577 *if2_seq = node->seq_out[HSR_PT_SLAVE_A];
579 if (node->addr_B_port != HSR_PT_NONE) {
580 port = hsr_port_get_hsr(hsr, node->addr_B_port);
581 *addr_b_ifindex = port->dev->ifindex;
583 *addr_b_ifindex = -1;