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 "hsr_main.h" 19#include "hsr_framereg.h" 20#include "hsr_netlink.h" 21 22/* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b, 23 * false otherwise. 24 */ 25static bool seq_nr_after(u16 a, u16 b) 26{ 27 /* Remove inconsistency where 28 * seq_nr_after(a, b) == seq_nr_before(a, b) 29 */ 30 if ((int)b - a == 32768) 31 return false; 32 33 return (((s16)(b - a)) < 0); 34} 35 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))) 38 39bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr) 40{ 41 struct hsr_self_node *sn; 42 bool ret = false; 43 44 rcu_read_lock(); 45 sn = rcu_dereference(hsr->self_node); 46 if (!sn) { 47 WARN_ONCE(1, "HSR: No self node\n"); 48 goto out; 49 } 50 51 if (ether_addr_equal(addr, sn->macaddress_A) || 52 ether_addr_equal(addr, sn->macaddress_B)) 53 ret = true; 54out: 55 rcu_read_unlock(); 56 return ret; 57} 58 59/* Search for mac entry. Caller must hold rcu read lock. 60 */ 61static struct hsr_node *find_node_by_addr_A(struct list_head *node_db, 62 const unsigned char addr[ETH_ALEN]) 63{ 64 struct hsr_node *node; 65 66 list_for_each_entry_rcu(node, node_db, mac_list) { 67 if (ether_addr_equal(node->macaddress_A, addr)) 68 return node; 69 } 70 71 return NULL; 72} 73 74/* Helper for device init; the self_node is used in hsr_rcv() to recognize 75 * frames from self that's been looped over the HSR ring. 76 */ 77int hsr_create_self_node(struct hsr_priv *hsr, 78 const unsigned char addr_a[ETH_ALEN], 79 const unsigned char addr_b[ETH_ALEN]) 80{ 81 struct hsr_self_node *sn, *old; 82 83 sn = kmalloc(sizeof(*sn), GFP_KERNEL); 84 if (!sn) 85 return -ENOMEM; 86 87 ether_addr_copy(sn->macaddress_A, addr_a); 88 ether_addr_copy(sn->macaddress_B, addr_b); 89 90 spin_lock_bh(&hsr->list_lock); 91 old = rcu_replace_pointer(hsr->self_node, sn, 92 lockdep_is_held(&hsr->list_lock)); 93 spin_unlock_bh(&hsr->list_lock); 94 95 if (old) 96 kfree_rcu(old, rcu_head); 97 return 0; 98} 99 100void hsr_del_self_node(struct hsr_priv *hsr) 101{ 102 struct hsr_self_node *old; 103 104 spin_lock_bh(&hsr->list_lock); 105 old = rcu_replace_pointer(hsr->self_node, NULL, 106 lockdep_is_held(&hsr->list_lock)); 107 spin_unlock_bh(&hsr->list_lock); 108 if (old) 109 kfree_rcu(old, rcu_head); 110} 111 112void hsr_del_nodes(struct list_head *node_db) 113{ 114 struct hsr_node *node; 115 struct hsr_node *tmp; 116 117 list_for_each_entry_safe(node, tmp, node_db, mac_list) 118 kfree(node); 119} 120 121void prp_handle_san_frame(bool san, enum hsr_port_type port, 122 struct hsr_node *node) 123{ 124 /* Mark if the SAN node is over LAN_A or LAN_B */ 125 if (port == HSR_PT_SLAVE_A) { 126 node->san_a = true; 127 return; 128 } 129 130 if (port == HSR_PT_SLAVE_B) 131 node->san_b = true; 132} 133 134/* Allocate an hsr_node and add it to node_db. 'addr' is the node's address_A; 135 * seq_out is used to initialize filtering of outgoing duplicate frames 136 * originating from the newly added node. 137 */ 138static struct hsr_node *hsr_add_node(struct hsr_priv *hsr, 139 struct list_head *node_db, 140 unsigned char addr[], 141 u16 seq_out, bool san, 142 enum hsr_port_type rx_port) 143{ 144 struct hsr_node *new_node, *node; 145 unsigned long now; 146 int i; 147 148 new_node = kzalloc(sizeof(*new_node), GFP_ATOMIC); 149 if (!new_node) 150 return NULL; 151 152 ether_addr_copy(new_node->macaddress_A, addr); 153 spin_lock_init(&new_node->seq_out_lock); 154 155 /* We are only interested in time diffs here, so use current jiffies 156 * as initialization. (0 could trigger an spurious ring error warning). 157 */ 158 now = jiffies; 159 for (i = 0; i < HSR_PT_PORTS; i++) { 160 new_node->time_in[i] = now; 161 new_node->time_out[i] = now; 162 } 163 for (i = 0; i < HSR_PT_PORTS; i++) 164 new_node->seq_out[i] = seq_out; 165 166 if (san && hsr->proto_ops->handle_san_frame) 167 hsr->proto_ops->handle_san_frame(san, rx_port, new_node); 168 169 spin_lock_bh(&hsr->list_lock); 170 list_for_each_entry_rcu(node, node_db, mac_list, 171 lockdep_is_held(&hsr->list_lock)) { 172 if (ether_addr_equal(node->macaddress_A, addr)) 173 goto out; 174 if (ether_addr_equal(node->macaddress_B, addr)) 175 goto out; 176 } 177 list_add_tail_rcu(&new_node->mac_list, node_db); 178 spin_unlock_bh(&hsr->list_lock); 179 return new_node; 180out: 181 spin_unlock_bh(&hsr->list_lock); 182 kfree(new_node); 183 return node; 184} 185 186void prp_update_san_info(struct hsr_node *node, bool is_sup) 187{ 188 if (!is_sup) 189 return; 190 191 node->san_a = false; 192 node->san_b = false; 193} 194 195/* Get the hsr_node from which 'skb' was sent. 196 */ 197struct hsr_node *hsr_get_node(struct hsr_port *port, struct list_head *node_db, 198 struct sk_buff *skb, bool is_sup, 199 enum hsr_port_type rx_port) 200{ 201 struct hsr_priv *hsr = port->hsr; 202 struct hsr_node *node; 203 struct ethhdr *ethhdr; 204 struct prp_rct *rct; 205 bool san = false; 206 u16 seq_out; 207 208 if (!skb_mac_header_was_set(skb)) 209 return NULL; 210 211 ethhdr = (struct ethhdr *)skb_mac_header(skb); 212 213 list_for_each_entry_rcu(node, node_db, mac_list) { 214 if (ether_addr_equal(node->macaddress_A, ethhdr->h_source)) { 215 if (hsr->proto_ops->update_san_info) 216 hsr->proto_ops->update_san_info(node, is_sup); 217 return node; 218 } 219 if (ether_addr_equal(node->macaddress_B, ethhdr->h_source)) { 220 if (hsr->proto_ops->update_san_info) 221 hsr->proto_ops->update_san_info(node, is_sup); 222 return node; 223 } 224 } 225 226 /* Everyone may create a node entry, connected node to a HSR/PRP 227 * device. 228 */ 229 if (ethhdr->h_proto == htons(ETH_P_PRP) || 230 ethhdr->h_proto == htons(ETH_P_HSR)) { 231 /* Check if skb contains hsr_ethhdr */ 232 if (skb->mac_len < sizeof(struct hsr_ethhdr)) 233 return NULL; 234 235 /* Use the existing sequence_nr from the tag as starting point 236 * for filtering duplicate frames. 237 */ 238 seq_out = hsr_get_skb_sequence_nr(skb) - 1; 239 } else { 240 rct = skb_get_PRP_rct(skb); 241 if (rct && prp_check_lsdu_size(skb, rct, is_sup)) { 242 seq_out = prp_get_skb_sequence_nr(rct); 243 } else { 244 if (rx_port != HSR_PT_MASTER) 245 san = true; 246 seq_out = HSR_SEQNR_START; 247 } 248 } 249 250 return hsr_add_node(hsr, node_db, ethhdr->h_source, seq_out, 251 san, rx_port); 252} 253 254/* Use the Supervision frame's info about an eventual macaddress_B for merging 255 * nodes that has previously had their macaddress_B registered as a separate 256 * node. 257 */ 258void hsr_handle_sup_frame(struct hsr_frame_info *frame) 259{ 260 struct hsr_node *node_curr = frame->node_src; 261 struct hsr_port *port_rcv = frame->port_rcv; 262 struct hsr_priv *hsr = port_rcv->hsr; 263 struct hsr_sup_payload *hsr_sp; 264 struct hsr_sup_tlv *hsr_sup_tlv; 265 struct hsr_node *node_real; 266 struct sk_buff *skb = NULL; 267 struct list_head *node_db; 268 struct ethhdr *ethhdr; 269 int i; 270 unsigned int pull_size = 0; 271 unsigned int total_pull_size = 0; 272 273 /* Here either frame->skb_hsr or frame->skb_prp should be 274 * valid as supervision frame always will have protocol 275 * header info. 276 */ 277 if (frame->skb_hsr) 278 skb = frame->skb_hsr; 279 else if (frame->skb_prp) 280 skb = frame->skb_prp; 281 else if (frame->skb_std) 282 skb = frame->skb_std; 283 if (!skb) 284 return; 285 286 /* Leave the ethernet header. */ 287 pull_size = sizeof(struct ethhdr); 288 skb_pull(skb, pull_size); 289 total_pull_size += pull_size; 290 291 ethhdr = (struct ethhdr *)skb_mac_header(skb); 292 293 /* And leave the HSR tag. */ 294 if (ethhdr->h_proto == htons(ETH_P_HSR)) { 295 pull_size = sizeof(struct hsr_tag); 296 skb_pull(skb, pull_size); 297 total_pull_size += pull_size; 298 } 299 300 /* And leave the HSR sup tag. */ 301 pull_size = sizeof(struct hsr_sup_tag); 302 skb_pull(skb, pull_size); 303 total_pull_size += pull_size; 304 305 /* get HSR sup payload */ 306 hsr_sp = (struct hsr_sup_payload *)skb->data; 307 308 /* Merge node_curr (registered on macaddress_B) into node_real */ 309 node_db = &port_rcv->hsr->node_db; 310 node_real = find_node_by_addr_A(node_db, hsr_sp->macaddress_A); 311 if (!node_real) 312 /* No frame received from AddrA of this node yet */ 313 node_real = hsr_add_node(hsr, node_db, hsr_sp->macaddress_A, 314 HSR_SEQNR_START - 1, true, 315 port_rcv->type); 316 if (!node_real) 317 goto done; /* No mem */ 318 if (node_real == node_curr) 319 /* Node has already been merged */ 320 goto done; 321 322 /* Leave the first HSR sup payload. */ 323 pull_size = sizeof(struct hsr_sup_payload); 324 skb_pull(skb, pull_size); 325 total_pull_size += pull_size; 326 327 /* Get second supervision tlv */ 328 hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data; 329 /* And check if it is a redbox mac TLV */ 330 if (hsr_sup_tlv->HSR_TLV_type == PRP_TLV_REDBOX_MAC) { 331 /* We could stop here after pushing hsr_sup_payload, 332 * or proceed and allow macaddress_B and for redboxes. 333 */ 334 /* Sanity check length */ 335 if (hsr_sup_tlv->HSR_TLV_length != 6) 336 goto done; 337 338 /* Leave the second HSR sup tlv. */ 339 pull_size = sizeof(struct hsr_sup_tlv); 340 skb_pull(skb, pull_size); 341 total_pull_size += pull_size; 342 343 /* Get redbox mac address. */ 344 hsr_sp = (struct hsr_sup_payload *)skb->data; 345 346 /* Check if redbox mac and node mac are equal. */ 347 if (!ether_addr_equal(node_real->macaddress_A, hsr_sp->macaddress_A)) { 348 /* This is a redbox supervision frame for a VDAN! */ 349 goto done; 350 } 351 } 352 353 ether_addr_copy(node_real->macaddress_B, ethhdr->h_source); 354 spin_lock_bh(&node_real->seq_out_lock); 355 for (i = 0; i < HSR_PT_PORTS; i++) { 356 if (!node_curr->time_in_stale[i] && 357 time_after(node_curr->time_in[i], node_real->time_in[i])) { 358 node_real->time_in[i] = node_curr->time_in[i]; 359 node_real->time_in_stale[i] = 360 node_curr->time_in_stale[i]; 361 } 362 if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i])) 363 node_real->seq_out[i] = node_curr->seq_out[i]; 364 } 365 spin_unlock_bh(&node_real->seq_out_lock); 366 node_real->addr_B_port = port_rcv->type; 367 368 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); 373 } 374 spin_unlock_bh(&hsr->list_lock); 375 376done: 377 /* Push back here */ 378 skb_push(skb, total_pull_size); 379} 380 381/* 'skb' is a frame meant for this host, that is to be passed to upper layers. 382 * 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. 386 */ 387void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb) 388{ 389 if (!skb_mac_header_was_set(skb)) { 390 WARN_ONCE(1, "%s: Mac header not set\n", __func__); 391 return; 392 } 393 394 memcpy(ð_hdr(skb)->h_source, node->macaddress_A, ETH_ALEN); 395} 396 397/* 'skb' is a frame meant for another host. 398 * 'port' is the outgoing interface 399 * 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. 405 */ 406void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb, 407 struct hsr_port *port) 408{ 409 struct hsr_node *node_dst; 410 411 if (!skb_mac_header_was_set(skb)) { 412 WARN_ONCE(1, "%s: Mac header not set\n", __func__); 413 return; 414 } 415 416 if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest)) 417 return; 418 419 node_dst = find_node_by_addr_A(&port->hsr->node_db, 420 eth_hdr(skb)->h_dest); 421 if (!node_dst) { 422 if (port->hsr->prot_version != PRP_V1 && net_ratelimit()) 423 netdev_err(skb->dev, "%s: Unknown node\n", __func__); 424 return; 425 } 426 if (port->type != node_dst->addr_B_port) 427 return; 428 429 if (is_valid_ether_addr(node_dst->macaddress_B)) 430 ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->macaddress_B); 431} 432 433void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port, 434 u16 sequence_nr) 435{ 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. 439 */ 440 if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) && 441 seq_nr_before(sequence_nr, node->seq_out[port->type])) 442 return; 443 444 node->time_in[port->type] = jiffies; 445 node->time_in_stale[port->type] = false; 446} 447 448/* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid 449 * ethhdr->h_source address and skb->mac_header set. 450 * 451 * Return: 452 * 1 if frame can be shown to have been sent recently on this interface, 453 * 0 otherwise, or 454 * negative error code on error 455 */ 456int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node, 457 u16 sequence_nr) 458{ 459 spin_lock_bh(&node->seq_out_lock); 460 if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]) && 461 time_is_after_jiffies(node->time_out[port->type] + 462 msecs_to_jiffies(HSR_ENTRY_FORGET_TIME))) { 463 spin_unlock_bh(&node->seq_out_lock); 464 return 1; 465 } 466 467 node->time_out[port->type] = jiffies; 468 node->seq_out[port->type] = sequence_nr; 469 spin_unlock_bh(&node->seq_out_lock); 470 return 0; 471} 472 473static struct hsr_port *get_late_port(struct hsr_priv *hsr, 474 struct hsr_node *node) 475{ 476 if (node->time_in_stale[HSR_PT_SLAVE_A]) 477 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A); 478 if (node->time_in_stale[HSR_PT_SLAVE_B]) 479 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B); 480 481 if (time_after(node->time_in[HSR_PT_SLAVE_B], 482 node->time_in[HSR_PT_SLAVE_A] + 483 msecs_to_jiffies(MAX_SLAVE_DIFF))) 484 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A); 485 if (time_after(node->time_in[HSR_PT_SLAVE_A], 486 node->time_in[HSR_PT_SLAVE_B] + 487 msecs_to_jiffies(MAX_SLAVE_DIFF))) 488 return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B); 489 490 return NULL; 491} 492 493/* Remove stale sequence_nr records. Called by timer every 494 * HSR_LIFE_CHECK_INTERVAL (two seconds or so). 495 */ 496void hsr_prune_nodes(struct timer_list *t) 497{ 498 struct hsr_priv *hsr = from_timer(hsr, t, prune_timer); 499 struct hsr_node *node; 500 struct hsr_node *tmp; 501 struct hsr_port *port; 502 unsigned long timestamp; 503 unsigned long time_a, time_b; 504 505 spin_lock_bh(&hsr->list_lock); 506 list_for_each_entry_safe(node, tmp, &hsr->node_db, mac_list) { 507 /* Don't prune own node. Neither time_in[HSR_PT_SLAVE_A] 508 * nor time_in[HSR_PT_SLAVE_B], will ever be updated for 509 * the master port. Thus the master node will be repeatedly 510 * pruned leading to packet loss. 511 */ 512 if (hsr_addr_is_self(hsr, node->macaddress_A)) 513 continue; 514 515 /* Shorthand */ 516 time_a = node->time_in[HSR_PT_SLAVE_A]; 517 time_b = node->time_in[HSR_PT_SLAVE_B]; 518 519 /* Check for timestamps old enough to risk wrap-around */ 520 if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET / 2)) 521 node->time_in_stale[HSR_PT_SLAVE_A] = true; 522 if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET / 2)) 523 node->time_in_stale[HSR_PT_SLAVE_B] = true; 524 525 /* Get age of newest frame from node. 526 * At least one time_in is OK here; nodes get pruned long 527 * before both time_ins can get stale 528 */ 529 timestamp = time_a; 530 if (node->time_in_stale[HSR_PT_SLAVE_A] || 531 (!node->time_in_stale[HSR_PT_SLAVE_B] && 532 time_after(time_b, time_a))) 533 timestamp = time_b; 534 535 /* Warn of ring error only as long as we get frames at all */ 536 if (time_is_after_jiffies(timestamp + 537 msecs_to_jiffies(1.5 * MAX_SLAVE_DIFF))) { 538 rcu_read_lock(); 539 port = get_late_port(hsr, node); 540 if (port) 541 hsr_nl_ringerror(hsr, node->macaddress_A, port); 542 rcu_read_unlock(); 543 } 544 545 /* Prune old entries */ 546 if (time_is_before_jiffies(timestamp + 547 msecs_to_jiffies(HSR_NODE_FORGET_TIME))) { 548 hsr_nl_nodedown(hsr, node->macaddress_A); 549 if (!node->removed) { 550 list_del_rcu(&node->mac_list); 551 node->removed = true; 552 /* Note that we need to free this entry later: */ 553 kfree_rcu(node, rcu_head); 554 } 555 } 556 } 557 spin_unlock_bh(&hsr->list_lock); 558 559 /* Restart timer */ 560 mod_timer(&hsr->prune_timer, 561 jiffies + msecs_to_jiffies(PRUNE_PERIOD)); 562} 563 564void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos, 565 unsigned char addr[ETH_ALEN]) 566{ 567 struct hsr_node *node; 568 569 if (!_pos) { 570 node = list_first_or_null_rcu(&hsr->node_db, 571 struct hsr_node, mac_list); 572 if (node) 573 ether_addr_copy(addr, node->macaddress_A); 574 return node; 575 } 576 577 node = _pos; 578 list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) { 579 ether_addr_copy(addr, node->macaddress_A); 580 return node; 581 } 582 583 return NULL; 584} 585 586int hsr_get_node_data(struct hsr_priv *hsr, 587 const unsigned char *addr, 588 unsigned char addr_b[ETH_ALEN], 589 unsigned int *addr_b_ifindex, 590 int *if1_age, 591 u16 *if1_seq, 592 int *if2_age, 593 u16 *if2_seq) 594{ 595 struct hsr_node *node; 596 struct hsr_port *port; 597 unsigned long tdiff; 598 599 node = find_node_by_addr_A(&hsr->node_db, addr); 600 if (!node) 601 return -ENOENT; 602 603 ether_addr_copy(addr_b, node->macaddress_B); 604 605 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A]; 606 if (node->time_in_stale[HSR_PT_SLAVE_A]) 607 *if1_age = INT_MAX; 608#if HZ <= MSEC_PER_SEC 609 else if (tdiff > msecs_to_jiffies(INT_MAX)) 610 *if1_age = INT_MAX; 611#endif 612 else 613 *if1_age = jiffies_to_msecs(tdiff); 614 615 tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B]; 616 if (node->time_in_stale[HSR_PT_SLAVE_B]) 617 *if2_age = INT_MAX; 618#if HZ <= MSEC_PER_SEC 619 else if (tdiff > msecs_to_jiffies(INT_MAX)) 620 *if2_age = INT_MAX; 621#endif 622 else 623 *if2_age = jiffies_to_msecs(tdiff); 624 625 /* Present sequence numbers as if they were incoming on interface */ 626 *if1_seq = node->seq_out[HSR_PT_SLAVE_B]; 627 *if2_seq = node->seq_out[HSR_PT_SLAVE_A]; 628 629 if (node->addr_B_port != HSR_PT_NONE) { 630 port = hsr_port_get_hsr(hsr, node->addr_B_port); 631 *addr_b_ifindex = port->dev->ifindex; 632 } else { 633 *addr_b_ifindex = -1; 634 } 635 636 return 0; 637} 638