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.
13 #include <linux/if_ether.h>
14 #include <linux/etherdevice.h>
15 #include <linux/slab.h>
16 #include <linux/rculist.h>
18 #include "hsr_framereg.h"
19 #include "hsr_netlink.h"
21 /* TODO: use hash lists for mac addresses (linux/jhash.h)? */
23 /* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
26 static bool seq_nr_after(u16 a, u16 b)
28 /* Remove inconsistency where
29 * seq_nr_after(a, b) == seq_nr_before(a, b)
31 if ((int)b - a == 32768)
34 return (((s16)(b - a)) < 0);
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)))
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 /* Allocate an hsr_node and add it to node_db. 'addr' is the node's address_A;
131 * seq_out is used to initialize filtering of outgoing duplicate frames
132 * originating from the newly added node.
134 static struct hsr_node *hsr_add_node(struct hsr_priv *hsr,
135 struct list_head *node_db,
136 unsigned char addr[],
139 struct hsr_node *new_node, *node;
143 new_node = kzalloc(sizeof(*new_node), GFP_ATOMIC);
147 ether_addr_copy(new_node->macaddress_A, addr);
149 /* We are only interested in time diffs here, so use current jiffies
150 * as initialization. (0 could trigger an spurious ring error warning).
153 for (i = 0; i < HSR_PT_PORTS; i++)
154 new_node->time_in[i] = now;
155 for (i = 0; i < HSR_PT_PORTS; i++)
156 new_node->seq_out[i] = seq_out;
158 spin_lock_bh(&hsr->list_lock);
159 list_for_each_entry_rcu(node, node_db, mac_list) {
160 if (ether_addr_equal(node->macaddress_A, addr))
162 if (ether_addr_equal(node->macaddress_B, addr))
165 list_add_tail_rcu(&new_node->mac_list, node_db);
166 spin_unlock_bh(&hsr->list_lock);
169 spin_unlock_bh(&hsr->list_lock);
174 /* Get the hsr_node from which 'skb' was sent.
176 struct hsr_node *hsr_get_node(struct hsr_port *port, struct sk_buff *skb,
179 struct list_head *node_db = &port->hsr->node_db;
180 struct hsr_priv *hsr = port->hsr;
181 struct hsr_node *node;
182 struct ethhdr *ethhdr;
185 if (!skb_mac_header_was_set(skb))
188 ethhdr = (struct ethhdr *)skb_mac_header(skb);
190 list_for_each_entry_rcu(node, node_db, mac_list) {
191 if (ether_addr_equal(node->macaddress_A, ethhdr->h_source))
193 if (ether_addr_equal(node->macaddress_B, ethhdr->h_source))
197 /* Everyone may create a node entry, connected node to a HSR device. */
199 if (ethhdr->h_proto == htons(ETH_P_PRP) ||
200 ethhdr->h_proto == htons(ETH_P_HSR)) {
201 /* Use the existing sequence_nr from the tag as starting point
202 * for filtering duplicate frames.
204 seq_out = hsr_get_skb_sequence_nr(skb) - 1;
206 /* this is called also for frames from master port and
207 * so warn only for non master ports
209 if (port->type != HSR_PT_MASTER)
210 WARN_ONCE(1, "%s: Non-HSR frame\n", __func__);
211 seq_out = HSR_SEQNR_START;
214 return hsr_add_node(hsr, node_db, ethhdr->h_source, seq_out);
217 /* Use the Supervision frame's info about an eventual macaddress_B for merging
218 * nodes that has previously had their macaddress_B registered as a separate
221 void hsr_handle_sup_frame(struct sk_buff *skb, struct hsr_node *node_curr,
222 struct hsr_port *port_rcv)
224 struct hsr_priv *hsr = port_rcv->hsr;
225 struct hsr_sup_payload *hsr_sp;
226 struct hsr_node *node_real;
227 struct list_head *node_db;
228 struct ethhdr *ethhdr;
231 ethhdr = (struct ethhdr *)skb_mac_header(skb);
233 /* Leave the ethernet header. */
234 skb_pull(skb, sizeof(struct ethhdr));
236 /* And leave the HSR tag. */
237 if (ethhdr->h_proto == htons(ETH_P_HSR))
238 skb_pull(skb, sizeof(struct hsr_tag));
240 /* And leave the HSR sup tag. */
241 skb_pull(skb, sizeof(struct hsr_sup_tag));
243 hsr_sp = (struct hsr_sup_payload *)skb->data;
245 /* Merge node_curr (registered on macaddress_B) into node_real */
246 node_db = &port_rcv->hsr->node_db;
247 node_real = find_node_by_addr_A(node_db, hsr_sp->macaddress_A);
249 /* No frame received from AddrA of this node yet */
250 node_real = hsr_add_node(hsr, node_db, hsr_sp->macaddress_A,
251 HSR_SEQNR_START - 1);
253 goto done; /* No mem */
254 if (node_real == node_curr)
255 /* Node has already been merged */
258 ether_addr_copy(node_real->macaddress_B, ethhdr->h_source);
259 for (i = 0; i < HSR_PT_PORTS; i++) {
260 if (!node_curr->time_in_stale[i] &&
261 time_after(node_curr->time_in[i], node_real->time_in[i])) {
262 node_real->time_in[i] = node_curr->time_in[i];
263 node_real->time_in_stale[i] =
264 node_curr->time_in_stale[i];
266 if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
267 node_real->seq_out[i] = node_curr->seq_out[i];
269 node_real->addr_B_port = port_rcv->type;
271 spin_lock_bh(&hsr->list_lock);
272 if (!node_curr->removed) {
273 list_del_rcu(&node_curr->mac_list);
274 node_curr->removed = true;
275 kfree_rcu(node_curr, rcu_head);
277 spin_unlock_bh(&hsr->list_lock);
280 skb_push(skb, sizeof(struct hsrv1_ethhdr_sp));
283 /* 'skb' is a frame meant for this host, that is to be passed to upper layers.
285 * If the frame was sent by a node's B interface, replace the source
286 * address with that node's "official" address (macaddress_A) so that upper
287 * layers recognize where it came from.
289 void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb)
291 if (!skb_mac_header_was_set(skb)) {
292 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
296 memcpy(ð_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN);
299 /* 'skb' is a frame meant for another host.
300 * 'port' is the outgoing interface
302 * Substitute the target (dest) MAC address if necessary, so the it matches the
303 * recipient interface MAC address, regardless of whether that is the
304 * recipient's A or B interface.
305 * This is needed to keep the packets flowing through switches that learn on
306 * which "side" the different interfaces are.
308 void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
309 struct hsr_port *port)
311 struct hsr_node *node_dst;
313 if (!skb_mac_header_was_set(skb)) {
314 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
318 if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
321 node_dst = find_node_by_addr_A(&port->hsr->node_db,
322 eth_hdr(skb)->h_dest);
325 netdev_err(skb->dev, "%s: Unknown node\n", __func__);
328 if (port->type != node_dst->addr_B_port)
331 ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B);
334 void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
337 /* Don't register incoming frames without a valid sequence number. This
338 * ensures entries of restarted nodes gets pruned so that they can
339 * re-register and resume communications.
341 if (seq_nr_before(sequence_nr, node->seq_out[port->type]))
344 node->time_in[port->type] = jiffies;
345 node->time_in_stale[port->type] = false;
348 /* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
349 * ethhdr->h_source address and skb->mac_header set.
352 * 1 if frame can be shown to have been sent recently on this interface,
354 * negative error code on error
356 int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
359 if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]))
362 node->seq_out[port->type] = sequence_nr;
366 static struct hsr_port *get_late_port(struct hsr_priv *hsr,
367 struct hsr_node *node)
369 if (node->time_in_stale[HSR_PT_SLAVE_A])
370 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
371 if (node->time_in_stale[HSR_PT_SLAVE_B])
372 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
374 if (time_after(node->time_in[HSR_PT_SLAVE_B],
375 node->time_in[HSR_PT_SLAVE_A] +
376 msecs_to_jiffies(MAX_SLAVE_DIFF)))
377 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
378 if (time_after(node->time_in[HSR_PT_SLAVE_A],
379 node->time_in[HSR_PT_SLAVE_B] +
380 msecs_to_jiffies(MAX_SLAVE_DIFF)))
381 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
386 /* Remove stale sequence_nr records. Called by timer every
387 * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
389 void hsr_prune_nodes(struct timer_list *t)
391 struct hsr_priv *hsr = from_timer(hsr, t, prune_timer);
392 struct hsr_node *node;
393 struct hsr_node *tmp;
394 struct hsr_port *port;
395 unsigned long timestamp;
396 unsigned long time_a, time_b;
398 spin_lock_bh(&hsr->list_lock);
399 list_for_each_entry_safe(node, tmp, &hsr->node_db, mac_list) {
400 /* Don't prune own node. Neither time_in[HSR_PT_SLAVE_A]
401 * nor time_in[HSR_PT_SLAVE_B], will ever be updated for
402 * the master port. Thus the master node will be repeatedly
403 * pruned leading to packet loss.
405 if (hsr_addr_is_self(hsr, node->macaddress_A))
409 time_a = node->time_in[HSR_PT_SLAVE_A];
410 time_b = node->time_in[HSR_PT_SLAVE_B];
412 /* Check for timestamps old enough to risk wrap-around */
413 if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET / 2))
414 node->time_in_stale[HSR_PT_SLAVE_A] = true;
415 if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET / 2))
416 node->time_in_stale[HSR_PT_SLAVE_B] = true;
418 /* Get age of newest frame from node.
419 * At least one time_in is OK here; nodes get pruned long
420 * before both time_ins can get stale
423 if (node->time_in_stale[HSR_PT_SLAVE_A] ||
424 (!node->time_in_stale[HSR_PT_SLAVE_B] &&
425 time_after(time_b, time_a)))
428 /* Warn of ring error only as long as we get frames at all */
429 if (time_is_after_jiffies(timestamp +
430 msecs_to_jiffies(1.5 * MAX_SLAVE_DIFF))) {
432 port = get_late_port(hsr, node);
434 hsr_nl_ringerror(hsr, node->macaddress_A, port);
438 /* Prune old entries */
439 if (time_is_before_jiffies(timestamp +
440 msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
441 hsr_nl_nodedown(hsr, node->macaddress_A);
442 if (!node->removed) {
443 list_del_rcu(&node->mac_list);
444 node->removed = true;
445 /* Note that we need to free this entry later: */
446 kfree_rcu(node, rcu_head);
450 spin_unlock_bh(&hsr->list_lock);
453 mod_timer(&hsr->prune_timer,
454 jiffies + msecs_to_jiffies(PRUNE_PERIOD));
457 void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
458 unsigned char addr[ETH_ALEN])
460 struct hsr_node *node;
463 node = list_first_or_null_rcu(&hsr->node_db,
464 struct hsr_node, mac_list);
466 ether_addr_copy(addr, node->macaddress_A);
471 list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) {
472 ether_addr_copy(addr, node->macaddress_A);
479 int hsr_get_node_data(struct hsr_priv *hsr,
480 const unsigned char *addr,
481 unsigned char addr_b[ETH_ALEN],
482 unsigned int *addr_b_ifindex,
488 struct hsr_node *node;
489 struct hsr_port *port;
492 node = find_node_by_addr_A(&hsr->node_db, addr);
496 ether_addr_copy(addr_b, node->macaddress_B);
498 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
499 if (node->time_in_stale[HSR_PT_SLAVE_A])
501 #if HZ <= MSEC_PER_SEC
502 else if (tdiff > msecs_to_jiffies(INT_MAX))
506 *if1_age = jiffies_to_msecs(tdiff);
508 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
509 if (node->time_in_stale[HSR_PT_SLAVE_B])
511 #if HZ <= MSEC_PER_SEC
512 else if (tdiff > msecs_to_jiffies(INT_MAX))
516 *if2_age = jiffies_to_msecs(tdiff);
518 /* Present sequence numbers as if they were incoming on interface */
519 *if1_seq = node->seq_out[HSR_PT_SLAVE_B];
520 *if2_seq = node->seq_out[HSR_PT_SLAVE_A];
522 if (node->addr_B_port != HSR_PT_NONE) {
523 port = hsr_port_get_hsr(hsr, node->addr_B_port);
524 *addr_b_ifindex = port->dev->ifindex;
526 *addr_b_ifindex = -1;