net/hsr/hsr_framereg.c

   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 <linux/jhash.h>
  19 #include "hsr_main.h"
  20 #include "hsr_framereg.h"
  21 #include "hsr_netlink.h"
  22
  23 #ifdef CONFIG_LOCKDEP
  24 int lockdep_hsr_is_held(spinlock_t *lock)
  25 {
  26         return lockdep_is_held(lock);
  27 }
  28 #endif
  29
  30 u32 hsr_mac_hash(struct hsr_priv *hsr, const unsigned char *addr)
  31 {
  32         u32 hash = jhash(addr, ETH_ALEN, hsr->hash_seed);
  33
  34         return reciprocal_scale(hash, hsr->hash_buckets);
  35 }
  36
  37 struct hsr_node *hsr_node_get_first(struct hlist_head *head, spinlock_t *lock)
  38 {
  39         struct hlist_node *first;
  40
  41         first = rcu_dereference_bh_check(hlist_first_rcu(head),
  42                                          lockdep_hsr_is_held(lock));
  43         if (first)
  44                 return hlist_entry(first, struct hsr_node, mac_list);
  45
  46         return NULL;
  47 }
  48
  49 /* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b,
  50  * false otherwise.
  51  */
  52 static bool seq_nr_after(u16 a, u16 b)
  53 {
  54         /* Remove inconsistency where
  55          * seq_nr_after(a, b) == seq_nr_before(a, b)
  56          */
  57         if ((int)b - a == 32768)
  58                 return false;
  59
  60         return (((s16)(b - a)) < 0);
  61 }
  62
  63 #define seq_nr_before(a, b)             seq_nr_after((b), (a))
  64 #define seq_nr_before_or_eq(a, b)       (!seq_nr_after((a), (b)))
  65
  66 bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr)
  67 {
  68         struct hsr_node *node;
  69
  70         node = hsr_node_get_first(&hsr->self_node_db, &hsr->list_lock);
  71         if (!node) {
  72                 WARN_ONCE(1, "HSR: No self node\n");
  73                 return false;
  74         }
  75
  76         if (ether_addr_equal(addr, node->macaddress_A))
  77                 return true;
  78         if (ether_addr_equal(addr, node->macaddress_B))
  79                 return true;
  80
  81         return false;
  82 }
  83
  84 /* Search for mac entry. Caller must hold rcu read lock.
  85  */
  86 static struct hsr_node *find_node_by_addr_A(struct hlist_head *node_db,
  87                                             const unsigned char addr[ETH_ALEN])
  88 {
  89         struct hsr_node *node;
  90
  91         hlist_for_each_entry_rcu(node, node_db, mac_list) {
  92                 if (ether_addr_equal(node->macaddress_A, addr))
  93                         return node;
  94         }
  95
  96         return NULL;
  97 }
  98
  99 /* Helper for device init; the self_node_db is used in hsr_rcv() to recognize
 100  * frames from self that's been looped over the HSR ring.
 101  */
 102 int hsr_create_self_node(struct hsr_priv *hsr,
 103                          const unsigned char addr_a[ETH_ALEN],
 104                          const unsigned char addr_b[ETH_ALEN])
 105 {
 106         struct hlist_head *self_node_db = &hsr->self_node_db;
 107         struct hsr_node *node, *oldnode;
 108
 109         node = kmalloc(sizeof(*node), GFP_KERNEL);
 110         if (!node)
 111                 return -ENOMEM;
 112
 113         ether_addr_copy(node->macaddress_A, addr_a);
 114         ether_addr_copy(node->macaddress_B, addr_b);
 115
 116         spin_lock_bh(&hsr->list_lock);
 117         oldnode = hsr_node_get_first(self_node_db, &hsr->list_lock);
 118         if (oldnode) {
 119                 hlist_replace_rcu(&oldnode->mac_list, &node->mac_list);
 120                 spin_unlock_bh(&hsr->list_lock);
 121                 kfree_rcu(oldnode, rcu_head);
 122         } else {
 123                 hlist_add_tail_rcu(&node->mac_list, self_node_db);
 124                 spin_unlock_bh(&hsr->list_lock);
 125         }
 126
 127         return 0;
 128 }
 129
 130 void hsr_del_self_node(struct hsr_priv *hsr)
 131 {
 132         struct hlist_head *self_node_db = &hsr->self_node_db;
 133         struct hsr_node *node;
 134
 135         spin_lock_bh(&hsr->list_lock);
 136         node = hsr_node_get_first(self_node_db, &hsr->list_lock);
 137         if (node) {
 138                 hlist_del_rcu(&node->mac_list);
 139                 kfree_rcu(node, rcu_head);
 140         }
 141         spin_unlock_bh(&hsr->list_lock);
 142 }
 143
 144 void hsr_del_nodes(struct hlist_head *node_db)
 145 {
 146         struct hsr_node *node;
 147         struct hlist_node *tmp;
 148
 149         hlist_for_each_entry_safe(node, tmp, node_db, mac_list)
 150                 kfree_rcu(node, rcu_head);
 151 }
 152
 153 void prp_handle_san_frame(bool san, enum hsr_port_type port,
 154                           struct hsr_node *node)
 155 {
 156         /* Mark if the SAN node is over LAN_A or LAN_B */
 157         if (port == HSR_PT_SLAVE_A) {
 158                 node->san_a = true;
 159                 return;
 160         }
 161
 162         if (port == HSR_PT_SLAVE_B)
 163                 node->san_b = true;
 164 }
 165
 166 /* Allocate an hsr_node and add it to node_db. 'addr' is the node's address_A;
 167  * seq_out is used to initialize filtering of outgoing duplicate frames
 168  * originating from the newly added node.
 169  */
 170 static struct hsr_node *hsr_add_node(struct hsr_priv *hsr,
 171                                      struct hlist_head *node_db,
 172                                      unsigned char addr[],
 173                                      u16 seq_out, bool san,
 174                                      enum hsr_port_type rx_port)
 175 {
 176         struct hsr_node *new_node, *node;
 177         unsigned long now;
 178         int i;
 179
 180         new_node = kzalloc(sizeof(*new_node), GFP_ATOMIC);
 181         if (!new_node)
 182                 return NULL;
 183
 184         ether_addr_copy(new_node->macaddress_A, addr);
 185
 186         /* We are only interested in time diffs here, so use current jiffies
 187          * as initialization. (0 could trigger an spurious ring error warning).
 188          */
 189         now = jiffies;
 190         for (i = 0; i < HSR_PT_PORTS; i++) {
 191                 new_node->time_in[i] = now;
 192                 new_node->time_out[i] = now;
 193         }
 194         for (i = 0; i < HSR_PT_PORTS; i++)
 195                 new_node->seq_out[i] = seq_out;
 196
 197         if (san && hsr->proto_ops->handle_san_frame)
 198                 hsr->proto_ops->handle_san_frame(san, rx_port, new_node);
 199
 200         spin_lock_bh(&hsr->list_lock);
 201         hlist_for_each_entry_rcu(node, node_db, mac_list,
 202                                  lockdep_hsr_is_held(&hsr->list_lock)) {
 203                 if (ether_addr_equal(node->macaddress_A, addr))
 204                         goto out;
 205                 if (ether_addr_equal(node->macaddress_B, addr))
 206                         goto out;
 207         }
 208         hlist_add_tail_rcu(&new_node->mac_list, node_db);
 209         spin_unlock_bh(&hsr->list_lock);
 210         return new_node;
 211 out:
 212         spin_unlock_bh(&hsr->list_lock);
 213         kfree(new_node);
 214         return node;
 215 }
 216
 217 void prp_update_san_info(struct hsr_node *node, bool is_sup)
 218 {
 219         if (!is_sup)
 220                 return;
 221
 222         node->san_a = false;
 223         node->san_b = false;
 224 }
 225
 226 /* Get the hsr_node from which 'skb' was sent.
 227  */
 228 struct hsr_node *hsr_get_node(struct hsr_port *port, struct hlist_head *node_db,
 229                               struct sk_buff *skb, bool is_sup,
 230                               enum hsr_port_type rx_port)
 231 {
 232         struct hsr_priv *hsr = port->hsr;
 233         struct hsr_node *node;
 234         struct ethhdr *ethhdr;
 235         struct prp_rct *rct;
 236         bool san = false;
 237         u16 seq_out;
 238
 239         if (!skb_mac_header_was_set(skb))
 240                 return NULL;
 241
 242         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 243
 244         hlist_for_each_entry_rcu(node, node_db, mac_list) {
 245                 if (ether_addr_equal(node->macaddress_A, ethhdr->h_source)) {
 246                         if (hsr->proto_ops->update_san_info)
 247                                 hsr->proto_ops->update_san_info(node, is_sup);
 248                         return node;
 249                 }
 250                 if (ether_addr_equal(node->macaddress_B, ethhdr->h_source)) {
 251                         if (hsr->proto_ops->update_san_info)
 252                                 hsr->proto_ops->update_san_info(node, is_sup);
 253                         return node;
 254                 }
 255         }
 256
 257         /* Everyone may create a node entry, connected node to a HSR/PRP
 258          * device.
 259          */
 260         if (ethhdr->h_proto == htons(ETH_P_PRP) ||
 261             ethhdr->h_proto == htons(ETH_P_HSR)) {
 262                 /* Use the existing sequence_nr from the tag as starting point
 263                  * for filtering duplicate frames.
 264                  */
 265                 seq_out = hsr_get_skb_sequence_nr(skb) - 1;
 266         } else {
 267                 rct = skb_get_PRP_rct(skb);
 268                 if (rct && prp_check_lsdu_size(skb, rct, is_sup)) {
 269                         seq_out = prp_get_skb_sequence_nr(rct);
 270                 } else {
 271                         if (rx_port != HSR_PT_MASTER)
 272                                 san = true;
 273                         seq_out = HSR_SEQNR_START;
 274                 }
 275         }
 276
 277         return hsr_add_node(hsr, node_db, ethhdr->h_source, seq_out,
 278                             san, rx_port);
 279 }
 280
 281 /* Use the Supervision frame's info about an eventual macaddress_B for merging
 282  * nodes that has previously had their macaddress_B registered as a separate
 283  * node.
 284  */
 285 void hsr_handle_sup_frame(struct hsr_frame_info *frame)
 286 {
 287         struct hsr_node *node_curr = frame->node_src;
 288         struct hsr_port *port_rcv = frame->port_rcv;
 289         struct hsr_priv *hsr = port_rcv->hsr;
 290         struct hsr_sup_payload *hsr_sp;
 291         struct hsr_sup_tlv *hsr_sup_tlv;
 292         struct hsr_node *node_real;
 293         struct sk_buff *skb = NULL;
 294         struct hlist_head *node_db;
 295         struct ethhdr *ethhdr;
 296         int i;
 297         unsigned int pull_size = 0;
 298         unsigned int total_pull_size = 0;
 299         u32 hash;
 300
 301         /* Here either frame->skb_hsr or frame->skb_prp should be
 302          * valid as supervision frame always will have protocol
 303          * header info.
 304          */
 305         if (frame->skb_hsr)
 306                 skb = frame->skb_hsr;
 307         else if (frame->skb_prp)
 308                 skb = frame->skb_prp;
 309         else if (frame->skb_std)
 310                 skb = frame->skb_std;
 311         if (!skb)
 312                 return;
 313
 314         /* Leave the ethernet header. */
 315         pull_size = sizeof(struct ethhdr);
 316         skb_pull(skb, pull_size);
 317         total_pull_size += pull_size;
 318
 319         ethhdr = (struct ethhdr *)skb_mac_header(skb);
 320
 321         /* And leave the HSR tag. */
 322         if (ethhdr->h_proto == htons(ETH_P_HSR)) {
 323                 pull_size = sizeof(struct ethhdr);
 324                 skb_pull(skb, pull_size);
 325                 total_pull_size += pull_size;
 326         }
 327
 328         /* And leave the HSR sup tag. */
 329         pull_size = sizeof(struct hsr_tag);
 330         skb_pull(skb, pull_size);
 331         total_pull_size += pull_size;
 332
 333         /* get HSR sup payload */
 334         hsr_sp = (struct hsr_sup_payload *)skb->data;
 335
 336         /* Merge node_curr (registered on macaddress_B) into node_real */
 337         node_db = port_rcv->hsr->node_db;
 338         hash = hsr_mac_hash(hsr, hsr_sp->macaddress_A);
 339         node_real = find_node_by_addr_A(&node_db[hash], hsr_sp->macaddress_A);
 340         if (!node_real)
 341                 /* No frame received from AddrA of this node yet */
 342                 node_real = hsr_add_node(hsr, &node_db[hash],
 343                                          hsr_sp->macaddress_A,
 344                                          HSR_SEQNR_START - 1, true,
 345                                          port_rcv->type);
 346         if (!node_real)
 347                 goto done; /* No mem */
 348         if (node_real == node_curr)
 349                 /* Node has already been merged */
 350                 goto done;
 351
 352         /* Leave the first HSR sup payload. */
 353         pull_size = sizeof(struct hsr_sup_payload);
 354         skb_pull(skb, pull_size);
 355         total_pull_size += pull_size;
 356
 357         /* Get second supervision tlv */
 358         hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
 359         /* And check if it is a redbox mac TLV */
 360         if (hsr_sup_tlv->HSR_TLV_type == PRP_TLV_REDBOX_MAC) {
 361                 /* We could stop here after pushing hsr_sup_payload,
 362                  * or proceed and allow macaddress_B and for redboxes.
 363                  */
 364                 /* Sanity check length */
 365                 if (hsr_sup_tlv->HSR_TLV_length != 6)
 366                         goto done;
 367
 368                 /* Leave the second HSR sup tlv. */
 369                 pull_size = sizeof(struct hsr_sup_tlv);
 370                 skb_pull(skb, pull_size);
 371                 total_pull_size += pull_size;
 372
 373                 /* Get redbox mac address. */
 374                 hsr_sp = (struct hsr_sup_payload *)skb->data;
 375
 376                 /* Check if redbox mac and node mac are equal. */
 377                 if (!ether_addr_equal(node_real->macaddress_A,
 378                                       hsr_sp->macaddress_A)) {
 379                         /* This is a redbox supervision frame for a VDAN! */
 380                         goto done;
 381                 }
 382         }
 383
 384         ether_addr_copy(node_real->macaddress_B, ethhdr->h_source);
 385         for (i = 0; i < HSR_PT_PORTS; i++) {
 386                 if (!node_curr->time_in_stale[i] &&
 387                     time_after(node_curr->time_in[i], node_real->time_in[i])) {
 388                         node_real->time_in[i] = node_curr->time_in[i];
 389                         node_real->time_in_stale[i] =
 390                                                 node_curr->time_in_stale[i];
 391                 }
 392                 if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i]))
 393                         node_real->seq_out[i] = node_curr->seq_out[i];
 394         }
 395         node_real->addr_B_port = port_rcv->type;
 396
 397         spin_lock_bh(&hsr->list_lock);
 398         hlist_del_rcu(&node_curr->mac_list);
 399         spin_unlock_bh(&hsr->list_lock);
 400         kfree_rcu(node_curr, rcu_head);
 401
 402 done:
 403         /* Push back here */
 404         skb_push(skb, total_pull_size);
 405 }
 406
 407 /* 'skb' is a frame meant for this host, that is to be passed to upper layers.
 408  *
 409  * If the frame was sent by a node's B interface, replace the source
 410  * address with that node's "official" address (macaddress_A) so that upper
 411  * layers recognize where it came from.
 412  */
 413 void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb)
 414 {
 415         if (!skb_mac_header_was_set(skb)) {
 416                 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
 417                 return;
 418         }
 419
 420         memcpy(&eth_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN);
 421 }
 422
 423 /* 'skb' is a frame meant for another host.
 424  * 'port' is the outgoing interface
 425  *
 426  * Substitute the target (dest) MAC address if necessary, so the it matches the
 427  * recipient interface MAC address, regardless of whether that is the
 428  * recipient's A or B interface.
 429  * This is needed to keep the packets flowing through switches that learn on
 430  * which "side" the different interfaces are.
 431  */
 432 void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
 433                          struct hsr_port *port)
 434 {
 435         struct hsr_node *node_dst;
 436         u32 hash;
 437
 438         if (!skb_mac_header_was_set(skb)) {
 439                 WARN_ONCE(1, "%s: Mac header not set\n", __func__);
 440                 return;
 441         }
 442
 443         if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest))
 444                 return;
 445
 446         hash = hsr_mac_hash(port->hsr, eth_hdr(skb)->h_dest);
 447         node_dst = find_node_by_addr_A(&port->hsr->node_db[hash],
 448                                        eth_hdr(skb)->h_dest);
 449         if (!node_dst) {
 450                 if (net_ratelimit())
 451                         netdev_err(skb->dev, "%s: Unknown node\n", __func__);
 452                 return;
 453         }
 454         if (port->type != node_dst->addr_B_port)
 455                 return;
 456
 457         if (is_valid_ether_addr(node_dst->macaddress_B))
 458                 ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B);
 459 }
 460
 461 void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
 462                            u16 sequence_nr)
 463 {
 464         /* Don't register incoming frames without a valid sequence number. This
 465          * ensures entries of restarted nodes gets pruned so that they can
 466          * re-register and resume communications.
 467          */
 468         if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
 469             seq_nr_before(sequence_nr, node->seq_out[port->type]))
 470                 return;
 471
 472         node->time_in[port->type] = jiffies;
 473         node->time_in_stale[port->type] = false;
 474 }
 475
 476 /* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid
 477  * ethhdr->h_source address and skb->mac_header set.
 478  *
 479  * Return:
 480  *       1 if frame can be shown to have been sent recently on this interface,
 481  *       0 otherwise, or
 482  *       negative error code on error
 483  */
 484 int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
 485                            u16 sequence_nr)
 486 {
 487         if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]) &&
 488             time_is_after_jiffies(node->time_out[port->type] +
 489             msecs_to_jiffies(HSR_ENTRY_FORGET_TIME)))
 490                 return 1;
 491
 492         node->time_out[port->type] = jiffies;
 493         node->seq_out[port->type] = sequence_nr;
 494         return 0;
 495 }
 496
 497 static struct hsr_port *get_late_port(struct hsr_priv *hsr,
 498                                       struct hsr_node *node)
 499 {
 500         if (node->time_in_stale[HSR_PT_SLAVE_A])
 501                 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
 502         if (node->time_in_stale[HSR_PT_SLAVE_B])
 503                 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
 504
 505         if (time_after(node->time_in[HSR_PT_SLAVE_B],
 506                        node->time_in[HSR_PT_SLAVE_A] +
 507                                         msecs_to_jiffies(MAX_SLAVE_DIFF)))
 508                 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
 509         if (time_after(node->time_in[HSR_PT_SLAVE_A],
 510                        node->time_in[HSR_PT_SLAVE_B] +
 511                                         msecs_to_jiffies(MAX_SLAVE_DIFF)))
 512                 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
 513
 514         return NULL;
 515 }
 516
 517 /* Remove stale sequence_nr records. Called by timer every
 518  * HSR_LIFE_CHECK_INTERVAL (two seconds or so).
 519  */
 520 void hsr_prune_nodes(struct timer_list *t)
 521 {
 522         struct hsr_priv *hsr = from_timer(hsr, t, prune_timer);
 523         struct hlist_node *tmp;
 524         struct hsr_node *node;
 525         struct hsr_port *port;
 526         unsigned long timestamp;
 527         unsigned long time_a, time_b;
 528         int i;
 529
 530         spin_lock_bh(&hsr->list_lock);
 531
 532         for (i = 0; i < hsr->hash_buckets; i++) {
 533                 hlist_for_each_entry_safe(node, tmp, &hsr->node_db[i],
 534                                           mac_list) {
 535                         /* Don't prune own node.
 536                          * Neither time_in[HSR_PT_SLAVE_A]
 537                          * nor time_in[HSR_PT_SLAVE_B], will ever be updated
 538                          * for the master port. Thus the master node will be
 539                          * repeatedly pruned leading to packet loss.
 540                          */
 541                         if (hsr_addr_is_self(hsr, node->macaddress_A))
 542                                 continue;
 543
 544                         /* Shorthand */
 545                         time_a = node->time_in[HSR_PT_SLAVE_A];
 546                         time_b = node->time_in[HSR_PT_SLAVE_B];
 547
 548                         /* Check for timestamps old enough to
 549                          * risk wrap-around
 550                          */
 551                         if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET / 2))
 552                                 node->time_in_stale[HSR_PT_SLAVE_A] = true;
 553                         if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET / 2))
 554                                 node->time_in_stale[HSR_PT_SLAVE_B] = true;
 555
 556                         /* Get age of newest frame from node.
 557                          * At least one time_in is OK here; nodes get pruned
 558                          * long before both time_ins can get stale
 559                          */
 560                         timestamp = time_a;
 561                         if (node->time_in_stale[HSR_PT_SLAVE_A] ||
 562                             (!node->time_in_stale[HSR_PT_SLAVE_B] &&
 563                              time_after(time_b, time_a)))
 564                                 timestamp = time_b;
 565
 566                         /* Warn of ring error only as long as we get
 567                          * frames at all
 568                          */
 569                         if (time_is_after_jiffies(timestamp +
 570                                                   msecs_to_jiffies(1.5 * MAX_SLAVE_DIFF))) {
 571                                 rcu_read_lock();
 572                                 port = get_late_port(hsr, node);
 573                                 if (port)
 574                                         hsr_nl_ringerror(hsr,
 575                                                          node->macaddress_A,
 576                                                          port);
 577                                 rcu_read_unlock();
 578                         }
 579
 580                         /* Prune old entries */
 581                         if (time_is_before_jiffies(timestamp +
 582                                                    msecs_to_jiffies(HSR_NODE_FORGET_TIME))) {
 583                                 hsr_nl_nodedown(hsr, node->macaddress_A);
 584                                 hlist_del_rcu(&node->mac_list);
 585                                 /* Note that we need to free this
 586                                  * entry later:
 587                                  */
 588                                 kfree_rcu(node, rcu_head);
 589                         }
 590                 }
 591         }
 592         spin_unlock_bh(&hsr->list_lock);
 593
 594         /* Restart timer */
 595         mod_timer(&hsr->prune_timer,
 596                   jiffies + msecs_to_jiffies(PRUNE_PERIOD));
 597 }
 598
 599 void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos,
 600                         unsigned char addr[ETH_ALEN])
 601 {
 602         struct hsr_node *node;
 603         u32 hash;
 604
 605         hash = hsr_mac_hash(hsr, addr);
 606
 607         if (!_pos) {
 608                 node = hsr_node_get_first(&hsr->node_db[hash],
 609                                           &hsr->list_lock);
 610                 if (node)
 611                         ether_addr_copy(addr, node->macaddress_A);
 612                 return node;
 613         }
 614
 615         node = _pos;
 616         hlist_for_each_entry_continue_rcu(node, mac_list) {
 617                 ether_addr_copy(addr, node->macaddress_A);
 618                 return node;
 619         }
 620
 621         return NULL;
 622 }
 623
 624 int hsr_get_node_data(struct hsr_priv *hsr,
 625                       const unsigned char *addr,
 626                       unsigned char addr_b[ETH_ALEN],
 627                       unsigned int *addr_b_ifindex,
 628                       int *if1_age,
 629                       u16 *if1_seq,
 630                       int *if2_age,
 631                       u16 *if2_seq)
 632 {
 633         struct hsr_node *node;
 634         struct hsr_port *port;
 635         unsigned long tdiff;
 636         u32 hash;
 637
 638         hash = hsr_mac_hash(hsr, addr);
 639
 640         node = find_node_by_addr_A(&hsr->node_db[hash], addr);
 641         if (!node)
 642                 return -ENOENT;
 643
 644         ether_addr_copy(addr_b, node->macaddress_B);
 645
 646         tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A];
 647         if (node->time_in_stale[HSR_PT_SLAVE_A])
 648                 *if1_age = INT_MAX;
 649 #if HZ <= MSEC_PER_SEC
 650         else if (tdiff > msecs_to_jiffies(INT_MAX))
 651                 *if1_age = INT_MAX;
 652 #endif
 653         else
 654                 *if1_age = jiffies_to_msecs(tdiff);
 655
 656         tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B];
 657         if (node->time_in_stale[HSR_PT_SLAVE_B])
 658                 *if2_age = INT_MAX;
 659 #if HZ <= MSEC_PER_SEC
 660         else if (tdiff > msecs_to_jiffies(INT_MAX))
 661                 *if2_age = INT_MAX;
 662 #endif
 663         else
 664                 *if2_age = jiffies_to_msecs(tdiff);
 665
 666         /* Present sequence numbers as if they were incoming on interface */
 667         *if1_seq = node->seq_out[HSR_PT_SLAVE_B];
 668         *if2_seq = node->seq_out[HSR_PT_SLAVE_A];
 669
 670         if (node->addr_B_port != HSR_PT_NONE) {
 671                 port = hsr_port_get_hsr(hsr, node->addr_B_port);
 672                 *addr_b_ifindex = port->dev->ifindex;
 673         } else {
 674                 *addr_b_ifindex = -1;
 675         }
 676
 677         return 0;
 678 }