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 * Frame router for HSR and PRP. 8 */ 9 10 #include "hsr_forward.h" 11 #include <linux/types.h> 12 #include <linux/skbuff.h> 13 #include <linux/etherdevice.h> 14 #include <linux/if_vlan.h> 15 #include "hsr_main.h" 16 #include "hsr_framereg.h" 17 18 struct hsr_node; 19 20 /* The uses I can see for these HSR supervision frames are: 21 * 1) Use the frames that are sent after node initialization ("HSR_TLV.Type = 22 * 22") to reset any sequence_nr counters belonging to that node. Useful if 23 * the other node's counter has been reset for some reason. 24 * -- 25 * Or not - resetting the counter and bridging the frame would create a 26 * loop, unfortunately. 27 * 28 * 2) Use the LifeCheck frames to detect ring breaks. I.e. if no LifeCheck 29 * frame is received from a particular node, we know something is wrong. 30 * We just register these (as with normal frames) and throw them away. 31 * 32 * 3) Allow different MAC addresses for the two slave interfaces, using the 33 * MacAddressA field. 34 */ 35 static bool is_supervision_frame(struct hsr_priv *hsr, struct sk_buff *skb) 36 { 37 struct ethhdr *eth_hdr; 38 struct hsr_sup_tag *hsr_sup_tag; 39 struct hsrv1_ethhdr_sp *hsr_V1_hdr; 40 struct hsr_sup_tlv *hsr_sup_tlv; 41 u16 total_length = 0; 42 43 WARN_ON_ONCE(!skb_mac_header_was_set(skb)); 44 eth_hdr = (struct ethhdr *)skb_mac_header(skb); 45 46 /* Correct addr? */ 47 if (!ether_addr_equal(eth_hdr->h_dest, 48 hsr->sup_multicast_addr)) 49 return false; 50 51 /* Correct ether type?. */ 52 if (!(eth_hdr->h_proto == htons(ETH_P_PRP) || 53 eth_hdr->h_proto == htons(ETH_P_HSR))) 54 return false; 55 56 /* Get the supervision header from correct location. */ 57 if (eth_hdr->h_proto == htons(ETH_P_HSR)) { /* Okay HSRv1. */ 58 total_length = sizeof(struct hsrv1_ethhdr_sp); 59 if (!pskb_may_pull(skb, total_length)) 60 return false; 61 62 hsr_V1_hdr = (struct hsrv1_ethhdr_sp *)skb_mac_header(skb); 63 if (hsr_V1_hdr->hsr.encap_proto != htons(ETH_P_PRP)) 64 return false; 65 66 hsr_sup_tag = &hsr_V1_hdr->hsr_sup; 67 } else { 68 total_length = sizeof(struct hsrv0_ethhdr_sp); 69 if (!pskb_may_pull(skb, total_length)) 70 return false; 71 72 hsr_sup_tag = 73 &((struct hsrv0_ethhdr_sp *)skb_mac_header(skb))->hsr_sup; 74 } 75 76 if (hsr_sup_tag->tlv.HSR_TLV_type != HSR_TLV_ANNOUNCE && 77 hsr_sup_tag->tlv.HSR_TLV_type != HSR_TLV_LIFE_CHECK && 78 hsr_sup_tag->tlv.HSR_TLV_type != PRP_TLV_LIFE_CHECK_DD && 79 hsr_sup_tag->tlv.HSR_TLV_type != PRP_TLV_LIFE_CHECK_DA) 80 return false; 81 if (hsr_sup_tag->tlv.HSR_TLV_length != 12 && 82 hsr_sup_tag->tlv.HSR_TLV_length != sizeof(struct hsr_sup_payload)) 83 return false; 84 85 /* Get next tlv */ 86 total_length += sizeof(struct hsr_sup_tlv) + hsr_sup_tag->tlv.HSR_TLV_length; 87 if (!pskb_may_pull(skb, total_length)) 88 return false; 89 skb_pull(skb, total_length); 90 hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data; 91 skb_push(skb, total_length); 92 93 /* if this is a redbox supervision frame we need to verify 94 * that more data is available 95 */ 96 if (hsr_sup_tlv->HSR_TLV_type == PRP_TLV_REDBOX_MAC) { 97 /* tlv length must be a length of a mac address */ 98 if (hsr_sup_tlv->HSR_TLV_length != sizeof(struct hsr_sup_payload)) 99 return false; 100 101 /* make sure another tlv follows */ 102 total_length += sizeof(struct hsr_sup_tlv) + hsr_sup_tlv->HSR_TLV_length; 103 if (!pskb_may_pull(skb, total_length)) 104 return false; 105 106 /* get next tlv */ 107 skb_pull(skb, total_length); 108 hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data; 109 skb_push(skb, total_length); 110 } 111 112 /* end of tlvs must follow at the end */ 113 if (hsr_sup_tlv->HSR_TLV_type == HSR_TLV_EOT && 114 hsr_sup_tlv->HSR_TLV_length != 0) 115 return false; 116 117 return true; 118 } 119 120 static struct sk_buff *create_stripped_skb_hsr(struct sk_buff *skb_in, 121 struct hsr_frame_info *frame) 122 { 123 struct sk_buff *skb; 124 int copylen; 125 unsigned char *dst, *src; 126 127 skb_pull(skb_in, HSR_HLEN); 128 skb = __pskb_copy(skb_in, skb_headroom(skb_in) - HSR_HLEN, GFP_ATOMIC); 129 skb_push(skb_in, HSR_HLEN); 130 if (!skb) 131 return NULL; 132 133 skb_reset_mac_header(skb); 134 135 if (skb->ip_summed == CHECKSUM_PARTIAL) 136 skb->csum_start -= HSR_HLEN; 137 138 copylen = 2 * ETH_ALEN; 139 if (frame->is_vlan) 140 copylen += VLAN_HLEN; 141 src = skb_mac_header(skb_in); 142 dst = skb_mac_header(skb); 143 memcpy(dst, src, copylen); 144 145 skb->protocol = eth_hdr(skb)->h_proto; 146 return skb; 147 } 148 149 struct sk_buff *hsr_get_untagged_frame(struct hsr_frame_info *frame, 150 struct hsr_port *port) 151 { 152 if (!frame->skb_std) { 153 if (frame->skb_hsr) 154 frame->skb_std = 155 create_stripped_skb_hsr(frame->skb_hsr, frame); 156 else 157 netdev_warn_once(port->dev, 158 "Unexpected frame received in hsr_get_untagged_frame()\n"); 159 160 if (!frame->skb_std) 161 return NULL; 162 } 163 164 return skb_clone(frame->skb_std, GFP_ATOMIC); 165 } 166 167 struct sk_buff *prp_get_untagged_frame(struct hsr_frame_info *frame, 168 struct hsr_port *port) 169 { 170 if (!frame->skb_std) { 171 if (frame->skb_prp) { 172 /* trim the skb by len - HSR_HLEN to exclude RCT */ 173 skb_trim(frame->skb_prp, 174 frame->skb_prp->len - HSR_HLEN); 175 frame->skb_std = 176 __pskb_copy(frame->skb_prp, 177 skb_headroom(frame->skb_prp), 178 GFP_ATOMIC); 179 } else { 180 /* Unexpected */ 181 WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n", 182 __FILE__, __LINE__, port->dev->name); 183 return NULL; 184 } 185 } 186 187 return skb_clone(frame->skb_std, GFP_ATOMIC); 188 } 189 190 static void prp_set_lan_id(struct prp_rct *trailer, 191 struct hsr_port *port) 192 { 193 int lane_id; 194 195 if (port->type == HSR_PT_SLAVE_A) 196 lane_id = 0; 197 else 198 lane_id = 1; 199 200 /* Add net_id in the upper 3 bits of lane_id */ 201 lane_id |= port->hsr->net_id; 202 set_prp_lan_id(trailer, lane_id); 203 } 204 205 /* Tailroom for PRP rct should have been created before calling this */ 206 static struct sk_buff *prp_fill_rct(struct sk_buff *skb, 207 struct hsr_frame_info *frame, 208 struct hsr_port *port) 209 { 210 struct prp_rct *trailer; 211 int min_size = ETH_ZLEN; 212 int lsdu_size; 213 214 if (!skb) 215 return skb; 216 217 if (frame->is_vlan) 218 min_size = VLAN_ETH_ZLEN; 219 220 if (skb_put_padto(skb, min_size)) 221 return NULL; 222 223 trailer = (struct prp_rct *)skb_put(skb, HSR_HLEN); 224 lsdu_size = skb->len - 14; 225 if (frame->is_vlan) 226 lsdu_size -= 4; 227 prp_set_lan_id(trailer, port); 228 set_prp_LSDU_size(trailer, lsdu_size); 229 trailer->sequence_nr = htons(frame->sequence_nr); 230 trailer->PRP_suffix = htons(ETH_P_PRP); 231 skb->protocol = eth_hdr(skb)->h_proto; 232 233 return skb; 234 } 235 236 static void hsr_set_path_id(struct hsr_ethhdr *hsr_ethhdr, 237 struct hsr_port *port) 238 { 239 int path_id; 240 241 if (port->type == HSR_PT_SLAVE_A) 242 path_id = 0; 243 else 244 path_id = 1; 245 246 set_hsr_tag_path(&hsr_ethhdr->hsr_tag, path_id); 247 } 248 249 static struct sk_buff *hsr_fill_tag(struct sk_buff *skb, 250 struct hsr_frame_info *frame, 251 struct hsr_port *port, u8 proto_version) 252 { 253 struct hsr_ethhdr *hsr_ethhdr; 254 int lsdu_size; 255 256 /* pad to minimum packet size which is 60 + 6 (HSR tag) */ 257 if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN)) 258 return NULL; 259 260 lsdu_size = skb->len - 14; 261 if (frame->is_vlan) 262 lsdu_size -= 4; 263 264 hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(skb); 265 266 hsr_set_path_id(hsr_ethhdr, port); 267 set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size); 268 hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr); 269 hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto; 270 hsr_ethhdr->ethhdr.h_proto = htons(proto_version ? 271 ETH_P_HSR : ETH_P_PRP); 272 skb->protocol = hsr_ethhdr->ethhdr.h_proto; 273 274 return skb; 275 } 276 277 /* If the original frame was an HSR tagged frame, just clone it to be sent 278 * unchanged. Otherwise, create a private frame especially tagged for 'port'. 279 */ 280 struct sk_buff *hsr_create_tagged_frame(struct hsr_frame_info *frame, 281 struct hsr_port *port) 282 { 283 unsigned char *dst, *src; 284 struct sk_buff *skb; 285 int movelen; 286 287 if (frame->skb_hsr) { 288 struct hsr_ethhdr *hsr_ethhdr = 289 (struct hsr_ethhdr *)skb_mac_header(frame->skb_hsr); 290 291 /* set the lane id properly */ 292 hsr_set_path_id(hsr_ethhdr, port); 293 return skb_clone(frame->skb_hsr, GFP_ATOMIC); 294 } else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) { 295 return skb_clone(frame->skb_std, GFP_ATOMIC); 296 } 297 298 /* Create the new skb with enough headroom to fit the HSR tag */ 299 skb = __pskb_copy(frame->skb_std, 300 skb_headroom(frame->skb_std) + HSR_HLEN, GFP_ATOMIC); 301 if (!skb) 302 return NULL; 303 skb_reset_mac_header(skb); 304 305 if (skb->ip_summed == CHECKSUM_PARTIAL) 306 skb->csum_start += HSR_HLEN; 307 308 movelen = ETH_HLEN; 309 if (frame->is_vlan) 310 movelen += VLAN_HLEN; 311 312 src = skb_mac_header(skb); 313 dst = skb_push(skb, HSR_HLEN); 314 memmove(dst, src, movelen); 315 skb_reset_mac_header(skb); 316 317 /* skb_put_padto free skb on error and hsr_fill_tag returns NULL in 318 * that case 319 */ 320 return hsr_fill_tag(skb, frame, port, port->hsr->prot_version); 321 } 322 323 struct sk_buff *prp_create_tagged_frame(struct hsr_frame_info *frame, 324 struct hsr_port *port) 325 { 326 struct sk_buff *skb; 327 328 if (frame->skb_prp) { 329 struct prp_rct *trailer = skb_get_PRP_rct(frame->skb_prp); 330 331 if (trailer) { 332 prp_set_lan_id(trailer, port); 333 } else { 334 WARN_ONCE(!trailer, "errored PRP skb"); 335 return NULL; 336 } 337 return skb_clone(frame->skb_prp, GFP_ATOMIC); 338 } else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) { 339 return skb_clone(frame->skb_std, GFP_ATOMIC); 340 } 341 342 skb = skb_copy_expand(frame->skb_std, 0, 343 skb_tailroom(frame->skb_std) + HSR_HLEN, 344 GFP_ATOMIC); 345 prp_fill_rct(skb, frame, port); 346 347 return skb; 348 } 349 350 static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev, 351 struct hsr_node *node_src) 352 { 353 bool was_multicast_frame; 354 int res, recv_len; 355 356 was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST); 357 hsr_addr_subst_source(node_src, skb); 358 skb_pull(skb, ETH_HLEN); 359 recv_len = skb->len; 360 res = netif_rx(skb); 361 if (res == NET_RX_DROP) { 362 dev->stats.rx_dropped++; 363 } else { 364 dev->stats.rx_packets++; 365 dev->stats.rx_bytes += recv_len; 366 if (was_multicast_frame) 367 dev->stats.multicast++; 368 } 369 } 370 371 static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port, 372 struct hsr_frame_info *frame) 373 { 374 if (frame->port_rcv->type == HSR_PT_MASTER) { 375 hsr_addr_subst_dest(frame->node_src, skb, port); 376 377 /* Address substitution (IEC62439-3 pp 26, 50): replace mac 378 * address of outgoing frame with that of the outgoing slave's. 379 */ 380 ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr); 381 } 382 return dev_queue_xmit(skb); 383 } 384 385 bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port) 386 { 387 return ((frame->port_rcv->type == HSR_PT_SLAVE_A && 388 port->type == HSR_PT_SLAVE_B) || 389 (frame->port_rcv->type == HSR_PT_SLAVE_B && 390 port->type == HSR_PT_SLAVE_A)); 391 } 392 393 bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port) 394 { 395 if (port->dev->features & NETIF_F_HW_HSR_FWD) 396 return prp_drop_frame(frame, port); 397 398 return false; 399 } 400 401 /* Forward the frame through all devices except: 402 * - Back through the receiving device 403 * - If it's a HSR frame: through a device where it has passed before 404 * - if it's a PRP frame: through another PRP slave device (no bridge) 405 * - To the local HSR master only if the frame is directly addressed to it, or 406 * a non-supervision multicast or broadcast frame. 407 * 408 * HSR slave devices should insert a HSR tag into the frame, or forward the 409 * frame unchanged if it's already tagged. Interlink devices should strip HSR 410 * tags if they're of the non-HSR type (but only after duplicate discard). The 411 * master device always strips HSR tags. 412 */ 413 static void hsr_forward_do(struct hsr_frame_info *frame) 414 { 415 struct hsr_port *port; 416 struct sk_buff *skb; 417 bool sent = false; 418 419 hsr_for_each_port(frame->port_rcv->hsr, port) { 420 struct hsr_priv *hsr = port->hsr; 421 /* Don't send frame back the way it came */ 422 if (port == frame->port_rcv) 423 continue; 424 425 /* Don't deliver locally unless we should */ 426 if (port->type == HSR_PT_MASTER && !frame->is_local_dest) 427 continue; 428 429 /* Deliver frames directly addressed to us to master only */ 430 if (port->type != HSR_PT_MASTER && frame->is_local_exclusive) 431 continue; 432 433 /* If hardware duplicate generation is enabled, only send out 434 * one port. 435 */ 436 if ((port->dev->features & NETIF_F_HW_HSR_DUP) && sent) 437 continue; 438 439 /* Don't send frame over port where it has been sent before. 440 * Also fro SAN, this shouldn't be done. 441 */ 442 if (!frame->is_from_san && 443 hsr_register_frame_out(port, frame->node_src, 444 frame->sequence_nr)) 445 continue; 446 447 if (frame->is_supervision && port->type == HSR_PT_MASTER) { 448 hsr_handle_sup_frame(frame); 449 continue; 450 } 451 452 /* Check if frame is to be dropped. Eg. for PRP no forward 453 * between ports. 454 */ 455 if (hsr->proto_ops->drop_frame && 456 hsr->proto_ops->drop_frame(frame, port)) 457 continue; 458 459 if (port->type != HSR_PT_MASTER) 460 skb = hsr->proto_ops->create_tagged_frame(frame, port); 461 else 462 skb = hsr->proto_ops->get_untagged_frame(frame, port); 463 464 if (!skb) { 465 frame->port_rcv->dev->stats.rx_dropped++; 466 continue; 467 } 468 469 skb->dev = port->dev; 470 if (port->type == HSR_PT_MASTER) { 471 hsr_deliver_master(skb, port->dev, frame->node_src); 472 } else { 473 if (!hsr_xmit(skb, port, frame)) 474 sent = true; 475 } 476 } 477 } 478 479 static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb, 480 struct hsr_frame_info *frame) 481 { 482 if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) { 483 frame->is_local_exclusive = true; 484 skb->pkt_type = PACKET_HOST; 485 } else { 486 frame->is_local_exclusive = false; 487 } 488 489 if (skb->pkt_type == PACKET_HOST || 490 skb->pkt_type == PACKET_MULTICAST || 491 skb->pkt_type == PACKET_BROADCAST) { 492 frame->is_local_dest = true; 493 } else { 494 frame->is_local_dest = false; 495 } 496 } 497 498 static void handle_std_frame(struct sk_buff *skb, 499 struct hsr_frame_info *frame) 500 { 501 struct hsr_port *port = frame->port_rcv; 502 struct hsr_priv *hsr = port->hsr; 503 504 frame->skb_hsr = NULL; 505 frame->skb_prp = NULL; 506 frame->skb_std = skb; 507 508 if (port->type != HSR_PT_MASTER) { 509 frame->is_from_san = true; 510 } else { 511 /* Sequence nr for the master node */ 512 lockdep_assert_held(&hsr->seqnr_lock); 513 frame->sequence_nr = hsr->sequence_nr; 514 hsr->sequence_nr++; 515 } 516 } 517 518 int hsr_fill_frame_info(__be16 proto, struct sk_buff *skb, 519 struct hsr_frame_info *frame) 520 { 521 struct hsr_port *port = frame->port_rcv; 522 struct hsr_priv *hsr = port->hsr; 523 524 /* HSRv0 supervisory frames double as a tag so treat them as tagged. */ 525 if ((!hsr->prot_version && proto == htons(ETH_P_PRP)) || 526 proto == htons(ETH_P_HSR)) { 527 /* Check if skb contains hsr_ethhdr */ 528 if (skb->mac_len < sizeof(struct hsr_ethhdr)) 529 return -EINVAL; 530 531 /* HSR tagged frame :- Data or Supervision */ 532 frame->skb_std = NULL; 533 frame->skb_prp = NULL; 534 frame->skb_hsr = skb; 535 frame->sequence_nr = hsr_get_skb_sequence_nr(skb); 536 return 0; 537 } 538 539 /* Standard frame or PRP from master port */ 540 handle_std_frame(skb, frame); 541 542 return 0; 543 } 544 545 int prp_fill_frame_info(__be16 proto, struct sk_buff *skb, 546 struct hsr_frame_info *frame) 547 { 548 /* Supervision frame */ 549 struct prp_rct *rct = skb_get_PRP_rct(skb); 550 551 if (rct && 552 prp_check_lsdu_size(skb, rct, frame->is_supervision)) { 553 frame->skb_hsr = NULL; 554 frame->skb_std = NULL; 555 frame->skb_prp = skb; 556 frame->sequence_nr = prp_get_skb_sequence_nr(rct); 557 return 0; 558 } 559 handle_std_frame(skb, frame); 560 561 return 0; 562 } 563 564 static int fill_frame_info(struct hsr_frame_info *frame, 565 struct sk_buff *skb, struct hsr_port *port) 566 { 567 struct hsr_priv *hsr = port->hsr; 568 struct hsr_vlan_ethhdr *vlan_hdr; 569 struct ethhdr *ethhdr; 570 __be16 proto; 571 int ret; 572 573 /* Check if skb contains ethhdr */ 574 if (skb->mac_len < sizeof(struct ethhdr)) 575 return -EINVAL; 576 577 memset(frame, 0, sizeof(*frame)); 578 frame->is_supervision = is_supervision_frame(port->hsr, skb); 579 frame->node_src = hsr_get_node(port, &hsr->node_db, skb, 580 frame->is_supervision, 581 port->type); 582 if (!frame->node_src) 583 return -1; /* Unknown node and !is_supervision, or no mem */ 584 585 ethhdr = (struct ethhdr *)skb_mac_header(skb); 586 frame->is_vlan = false; 587 proto = ethhdr->h_proto; 588 589 if (proto == htons(ETH_P_8021Q)) 590 frame->is_vlan = true; 591 592 if (frame->is_vlan) { 593 vlan_hdr = (struct hsr_vlan_ethhdr *)ethhdr; 594 proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto; 595 /* FIXME: */ 596 netdev_warn_once(skb->dev, "VLAN not yet supported"); 597 } 598 599 frame->is_from_san = false; 600 frame->port_rcv = port; 601 ret = hsr->proto_ops->fill_frame_info(proto, skb, frame); 602 if (ret) 603 return ret; 604 605 check_local_dest(port->hsr, skb, frame); 606 607 return 0; 608 } 609 610 /* Must be called holding rcu read lock (because of the port parameter) */ 611 void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port) 612 { 613 struct hsr_frame_info frame; 614 615 rcu_read_lock(); 616 if (fill_frame_info(&frame, skb, port) < 0) 617 goto out_drop; 618 619 hsr_register_frame_in(frame.node_src, port, frame.sequence_nr); 620 hsr_forward_do(&frame); 621 rcu_read_unlock(); 622 /* Gets called for ingress frames as well as egress from master port. 623 * So check and increment stats for master port only here. 624 */ 625 if (port->type == HSR_PT_MASTER) { 626 port->dev->stats.tx_packets++; 627 port->dev->stats.tx_bytes += skb->len; 628 } 629 630 kfree_skb(frame.skb_hsr); 631 kfree_skb(frame.skb_prp); 632 kfree_skb(frame.skb_std); 633 return; 634 635 out_drop: 636 rcu_read_unlock(); 637 port->dev->stats.tx_dropped++; 638 kfree_skb(skb); 639 } 640