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 /* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
25 static bool seq_nr_after(u16 a, u16 b)
27 /* Remove inconsistency where
28 * seq_nr_after(a, b) == seq_nr_before(a, b)
30 if ((int)b - a == 32768)
33 return (((s16)(b - a)) < 0);
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)))
39 bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr)
41 struct hsr_node *node;
43 node = list_first_or_null_rcu(&hsr->self_node_db, struct hsr_node,
46 WARN_ONCE(1, "HSR: No self node\n");
50 if (ether_addr_equal(addr, node->macaddress_A))
52 if (ether_addr_equal(addr, node->macaddress_B))
58 /* Search for mac entry. Caller must hold rcu read lock.
60 static struct hsr_node *find_node_by_addr_A(struct list_head *node_db,
61 const unsigned char addr[ETH_ALEN])
63 struct hsr_node *node;
65 list_for_each_entry_rcu(node, node_db, mac_list) {
66 if (ether_addr_equal(node->macaddress_A, addr))
73 /* Helper for device init; the self_node_db is used in hsr_rcv() to recognize
74 * frames from self that's been looped over the HSR ring.
76 int hsr_create_self_node(struct hsr_priv *hsr,
77 const unsigned char addr_a[ETH_ALEN],
78 const unsigned char addr_b[ETH_ALEN])
80 struct list_head *self_node_db = &hsr->self_node_db;
81 struct hsr_node *node, *oldnode;
83 node = kmalloc(sizeof(*node), GFP_KERNEL);
87 ether_addr_copy(node->macaddress_A, addr_a);
88 ether_addr_copy(node->macaddress_B, addr_b);
90 spin_lock_bh(&hsr->list_lock);
91 oldnode = list_first_or_null_rcu(self_node_db,
92 struct hsr_node, mac_list);
94 list_replace_rcu(&oldnode->mac_list, &node->mac_list);
95 spin_unlock_bh(&hsr->list_lock);
96 kfree_rcu(oldnode, rcu_head);
98 list_add_tail_rcu(&node->mac_list, self_node_db);
99 spin_unlock_bh(&hsr->list_lock);
105 void hsr_del_self_node(struct hsr_priv *hsr)
107 struct list_head *self_node_db = &hsr->self_node_db;
108 struct hsr_node *node;
110 spin_lock_bh(&hsr->list_lock);
111 node = list_first_or_null_rcu(self_node_db, struct hsr_node, mac_list);
113 list_del_rcu(&node->mac_list);
114 kfree_rcu(node, rcu_head);
116 spin_unlock_bh(&hsr->list_lock);
119 void hsr_del_nodes(struct list_head *node_db)
121 struct hsr_node *node;
122 struct hsr_node *tmp;
124 list_for_each_entry_safe(node, tmp, node_db, mac_list)
128 void prp_handle_san_frame(bool san, enum hsr_port_type port,
129 struct hsr_node *node)
131 /* Mark if the SAN node is over LAN_A or LAN_B */
132 if (port == HSR_PT_SLAVE_A) {
137 if (port == HSR_PT_SLAVE_B)
141 /* Allocate an hsr_node and add it to node_db. 'addr' is the node's address_A;
142 * seq_out is used to initialize filtering of outgoing duplicate frames
143 * originating from the newly added node.
145 static struct hsr_node *hsr_add_node(struct hsr_priv *hsr,
146 struct list_head *node_db,
147 unsigned char addr[],
148 u16 seq_out, bool san,
149 enum hsr_port_type rx_port)
151 struct hsr_node *new_node, *node;
155 new_node = kzalloc(sizeof(*new_node), GFP_ATOMIC);
159 ether_addr_copy(new_node->macaddress_A, addr);
161 /* We are only interested in time diffs here, so use current jiffies
162 * as initialization. (0 could trigger an spurious ring error warning).
165 for (i = 0; i < HSR_PT_PORTS; i++) {
166 new_node->time_in[i] = now;
167 new_node->time_out[i] = now;
169 for (i = 0; i < HSR_PT_PORTS; i++)
170 new_node->seq_out[i] = seq_out;
172 if (san && hsr->proto_ops->handle_san_frame)
173 hsr->proto_ops->handle_san_frame(san, rx_port, new_node);
175 spin_lock_bh(&hsr->list_lock);
176 list_for_each_entry_rcu(node, node_db, mac_list,
177 lockdep_is_held(&hsr->list_lock)) {
178 if (ether_addr_equal(node->macaddress_A, addr))
180 if (ether_addr_equal(node->macaddress_B, addr))
183 list_add_tail_rcu(&new_node->mac_list, node_db);
184 spin_unlock_bh(&hsr->list_lock);
187 spin_unlock_bh(&hsr->list_lock);
192 void prp_update_san_info(struct hsr_node *node, bool is_sup)
201 /* Get the hsr_node from which 'skb' was sent.
203 struct hsr_node *hsr_get_node(struct hsr_port *port, struct list_head *node_db,
204 struct sk_buff *skb, bool is_sup,
205 enum hsr_port_type rx_port)
207 struct hsr_priv *hsr = port->hsr;
208 struct hsr_node *node;
209 struct ethhdr *ethhdr;
214 if (!skb_mac_header_was_set(skb))
217 ethhdr = (struct ethhdr *)skb_mac_header(skb);
219 list_for_each_entry_rcu(node, node_db, mac_list) {
220 if (ether_addr_equal(node->macaddress_A, ethhdr->h_source)) {
221 if (hsr->proto_ops->update_san_info)
222 hsr->proto_ops->update_san_info(node, is_sup);
225 if (ether_addr_equal(node->macaddress_B, ethhdr->h_source)) {
226 if (hsr->proto_ops->update_san_info)
227 hsr->proto_ops->update_san_info(node, is_sup);
232 /* Everyone may create a node entry, connected node to a HSR/PRP
235 if (ethhdr->h_proto == htons(ETH_P_PRP) ||
236 ethhdr->h_proto == htons(ETH_P_HSR)) {
237 /* Use the existing sequence_nr from the tag as starting point
238 * for filtering duplicate frames.
240 seq_out = hsr_get_skb_sequence_nr(skb) - 1;
242 rct = skb_get_PRP_rct(skb);
243 if (rct && prp_check_lsdu_size(skb, rct, is_sup)) {
244 seq_out = prp_get_skb_sequence_nr(rct);
246 if (rx_port != HSR_PT_MASTER)
248 seq_out = HSR_SEQNR_START;
252 return hsr_add_node(hsr, node_db, ethhdr->h_source, seq_out,
256 /* Use the Supervision frame's info about an eventual macaddress_B for merging
257 * nodes that has previously had their macaddress_B registered as a separate
260 void hsr_handle_sup_frame(struct hsr_frame_info *frame)
262 struct hsr_node *node_curr = frame->node_src;
263 struct hsr_port *port_rcv = frame->port_rcv;
264 struct hsr_priv *hsr = port_rcv->hsr;
265 struct hsr_sup_payload *hsr_sp;
266 struct hsr_sup_tlv *hsr_sup_tlv;
267 struct hsr_node *node_real;
268 struct sk_buff *skb = NULL;
269 struct list_head *node_db;
270 struct ethhdr *ethhdr;
272 unsigned int pull_size = 0;
273 unsigned int total_pull_size = 0;
275 /* Here either frame->skb_hsr or frame->skb_prp should be
276 * valid as supervision frame always will have protocol
280 skb = frame->skb_hsr;
281 else if (frame->skb_prp)
282 skb = frame->skb_prp;
283 else if (frame->skb_std)
284 skb = frame->skb_std;
288 /* Leave the ethernet header. */
289 pull_size = sizeof(struct ethhdr);
290 skb_pull(skb, pull_size);
291 total_pull_size += pull_size;
293 ethhdr = (struct ethhdr *)skb_mac_header(skb);
295 /* And leave the HSR tag. */
296 if (ethhdr->h_proto == htons(ETH_P_HSR)) {
297 pull_size = sizeof(struct ethhdr);
298 skb_pull(skb, pull_size);
299 total_pull_size += pull_size;
302 /* And leave the HSR sup tag. */
303 pull_size = sizeof(struct hsr_tag);
304 skb_pull(skb, pull_size);
305 total_pull_size += pull_size;
307 /* get HSR sup payload */
308 hsr_sp = (struct hsr_sup_payload *)skb->data;
310 /* Merge node_curr (registered on macaddress_B) into node_real */
311 node_db = &port_rcv->hsr->node_db;
312 node_real = find_node_by_addr_A(node_db, hsr_sp->macaddress_A);
314 /* No frame received from AddrA of this node yet */
315 node_real = hsr_add_node(hsr, node_db, hsr_sp->macaddress_A,
316 HSR_SEQNR_START - 1, true,
319 goto done; /* No mem */
320 if (node_real == node_curr)
321 /* Node has already been merged */
324 /* Leave the first HSR sup payload. */
325 pull_size = sizeof(struct hsr_sup_payload);
326 skb_pull(skb, pull_size);
327 total_pull_size += pull_size;
329 /* Get second supervision tlv */
330 hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
331 /* And check if it is a redbox mac TLV */
332 if (hsr_sup_tlv->HSR_TLV_type == PRP_TLV_REDBOX_MAC) {
333 /* We could stop here after pushing hsr_sup_payload,
334 * or proceed and allow macaddress_B and for redboxes.
336 /* Sanity check length */
337 if (hsr_sup_tlv->HSR_TLV_length != 6)
340 /* Leave the second HSR sup tlv. */
341 pull_size = sizeof(struct hsr_sup_tlv);
342 skb_pull(skb, pull_size);
343 total_pull_size += pull_size;
345 /* Get redbox mac address. */
346 hsr_sp = (struct hsr_sup_payload *)skb->data;
348 /* Check if redbox mac and node mac are equal. */
349 if (!ether_addr_equal(node_real->macaddress_A, hsr_sp->macaddress_A)) {
350 /* This is a redbox supervision frame for a VDAN! */
355 ether_addr_copy(node_real->macaddress_B, ethhdr->h_source);
356 for (i = 0; i < HSR_PT_PORTS; i++) {
357 if (!node_curr->time_in_stale[i] &&
358 time_after(node_curr->time_in[i], node_real->time_in[i])) {
359 node_real->time_in[i] = node_curr->time_in[i];
360 node_real->time_in_stale[i] =
361 node_curr->time_in_stale[i];
363 if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
364 node_real->seq_out[i] = node_curr->seq_out[i];
366 node_real->addr_B_port = port_rcv->type;
368 spin_lock_bh(&hsr->list_lock);
369 if (!node_curr->removed) {
370 list_del_rcu(&node_curr->mac_list);
371 node_curr->removed = true;
372 kfree_rcu(node_curr, rcu_head);
374 spin_unlock_bh(&hsr->list_lock);
378 skb_push(skb, total_pull_size);
381 /* 'skb' is a frame meant for this host, that is to be passed to upper layers.
383 * If the frame was sent by a node's B interface, replace the source
384 * address with that node's "official" address (macaddress_A) so that upper
385 * layers recognize where it came from.
387 void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb)
389 if (!skb_mac_header_was_set(skb)) {
390 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
394 memcpy(ð_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN);
397 /* 'skb' is a frame meant for another host.
398 * 'port' is the outgoing interface
400 * Substitute the target (dest) MAC address if necessary, so the it matches the
401 * recipient interface MAC address, regardless of whether that is the
402 * recipient's A or B interface.
403 * This is needed to keep the packets flowing through switches that learn on
404 * which "side" the different interfaces are.
406 void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
407 struct hsr_port *port)
409 struct hsr_node *node_dst;
411 if (!skb_mac_header_was_set(skb)) {
412 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
416 if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
419 node_dst = find_node_by_addr_A(&port->hsr->node_db,
420 eth_hdr(skb)->h_dest);
423 netdev_err(skb->dev, "%s: Unknown node\n", __func__);
426 if (port->type != node_dst->addr_B_port)
429 if (is_valid_ether_addr(node_dst->macaddress_B))
430 ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B);
433 void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
436 /* Don't register incoming frames without a valid sequence number. This
437 * ensures entries of restarted nodes gets pruned so that they can
438 * re-register and resume communications.
440 if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
441 seq_nr_before(sequence_nr, node->seq_out[port->type]))
444 node->time_in[port->type] = jiffies;
445 node->time_in_stale[port->type] = false;
448 /* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
449 * ethhdr->h_source address and skb->mac_header set.
452 * 1 if frame can be shown to have been sent recently on this interface,
454 * negative error code on error
456 int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
459 if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]) &&
460 time_is_after_jiffies(node->time_out[port->type] +
461 msecs_to_jiffies(HSR_ENTRY_FORGET_TIME)))
464 node->time_out[port->type] = jiffies;
465 node->seq_out[port->type] = sequence_nr;
469 static struct hsr_port *get_late_port(struct hsr_priv *hsr,
470 struct hsr_node *node)
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);
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);
489 /* Remove stale sequence_nr records. Called by timer every
490 * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
492 void hsr_prune_nodes(struct timer_list *t)
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;
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.
508 if (hsr_addr_is_self(hsr, node->macaddress_A))
512 time_a = node->time_in[HSR_PT_SLAVE_A];
513 time_b = node->time_in[HSR_PT_SLAVE_B];
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;
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
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)))
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))) {
535 port = get_late_port(hsr, node);
537 hsr_nl_ringerror(hsr, node->macaddress_A, port);
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);
553 spin_unlock_bh(&hsr->list_lock);
556 mod_timer(&hsr->prune_timer,
557 jiffies + msecs_to_jiffies(PRUNE_PERIOD));
560 void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
561 unsigned char addr[ETH_ALEN])
563 struct hsr_node *node;
566 node = list_first_or_null_rcu(&hsr->node_db,
567 struct hsr_node, mac_list);
569 ether_addr_copy(addr, node->macaddress_A);
574 list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
575 ether_addr_copy(addr, node->macaddress_A);
582 int 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,
591 struct hsr_node *node;
592 struct hsr_port *port;
595 node = find_node_by_addr_A(&hsr->node_db, addr);
599 ether_addr_copy(addr_b, node->macaddress_B);
601 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
602 if (node->time_in_stale[HSR_PT_SLAVE_A])
604 #if HZ <= MSEC_PER_SEC
605 else if (tdiff > msecs_to_jiffies(INT_MAX))
609 *if1_age = jiffies_to_msecs(tdiff);
611 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
612 if (node->time_in_stale[HSR_PT_SLAVE_B])
614 #if HZ <= MSEC_PER_SEC
615 else if (tdiff > msecs_to_jiffies(INT_MAX))
619 *if2_age = jiffies_to_msecs(tdiff);
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];
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;
629 *addr_b_ifindex = -1;