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 /* Unexpected */ 158 WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n", 159 __FILE__, __LINE__, port->dev->name); 160 return NULL; 161 } 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; 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 res = netif_rx(skb); 360 if (res == NET_RX_DROP) { 361 dev->stats.rx_dropped++; 362 } else { 363 dev->stats.rx_packets++; 364 dev->stats.rx_bytes += skb->len; 365 if (was_multicast_frame) 366 dev->stats.multicast++; 367 } 368 } 369 370 static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port, 371 struct hsr_frame_info *frame) 372 { 373 if (frame->port_rcv->type == HSR_PT_MASTER) { 374 hsr_addr_subst_dest(frame->node_src, skb, port); 375 376 /* Address substitution (IEC62439-3 pp 26, 50): replace mac 377 * address of outgoing frame with that of the outgoing slave's. 378 */ 379 ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr); 380 } 381 return dev_queue_xmit(skb); 382 } 383 384 bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port) 385 { 386 return ((frame->port_rcv->type == HSR_PT_SLAVE_A && 387 port->type == HSR_PT_SLAVE_B) || 388 (frame->port_rcv->type == HSR_PT_SLAVE_B && 389 port->type == HSR_PT_SLAVE_A)); 390 } 391 392 bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port) 393 { 394 if (port->dev->features & NETIF_F_HW_HSR_FWD) 395 return prp_drop_frame(frame, port); 396 397 return false; 398 } 399 400 /* Forward the frame through all devices except: 401 * - Back through the receiving device 402 * - If it's a HSR frame: through a device where it has passed before 403 * - if it's a PRP frame: through another PRP slave device (no bridge) 404 * - To the local HSR master only if the frame is directly addressed to it, or 405 * a non-supervision multicast or broadcast frame. 406 * 407 * HSR slave devices should insert a HSR tag into the frame, or forward the 408 * frame unchanged if it's already tagged. Interlink devices should strip HSR 409 * tags if they're of the non-HSR type (but only after duplicate discard). The 410 * master device always strips HSR tags. 411 */ 412 static void hsr_forward_do(struct hsr_frame_info *frame) 413 { 414 struct hsr_port *port; 415 struct sk_buff *skb; 416 bool sent = false; 417 418 hsr_for_each_port(frame->port_rcv->hsr, port) { 419 struct hsr_priv *hsr = port->hsr; 420 /* Don't send frame back the way it came */ 421 if (port == frame->port_rcv) 422 continue; 423 424 /* Don't deliver locally unless we should */ 425 if (port->type == HSR_PT_MASTER && !frame->is_local_dest) 426 continue; 427 428 /* Deliver frames directly addressed to us to master only */ 429 if (port->type != HSR_PT_MASTER && frame->is_local_exclusive) 430 continue; 431 432 /* If hardware duplicate generation is enabled, only send out 433 * one port. 434 */ 435 if ((port->dev->features & NETIF_F_HW_HSR_DUP) && sent) 436 continue; 437 438 /* Don't send frame over port where it has been sent before. 439 * Also fro SAN, this shouldn't be done. 440 */ 441 if (!frame->is_from_san && 442 hsr_register_frame_out(port, frame->node_src, 443 frame->sequence_nr)) 444 continue; 445 446 if (frame->is_supervision && port->type == HSR_PT_MASTER) { 447 hsr_handle_sup_frame(frame); 448 continue; 449 } 450 451 /* Check if frame is to be dropped. Eg. for PRP no forward 452 * between ports. 453 */ 454 if (hsr->proto_ops->drop_frame && 455 hsr->proto_ops->drop_frame(frame, port)) 456 continue; 457 458 if (port->type != HSR_PT_MASTER) 459 skb = hsr->proto_ops->create_tagged_frame(frame, port); 460 else 461 skb = hsr->proto_ops->get_untagged_frame(frame, port); 462 463 if (!skb) { 464 frame->port_rcv->dev->stats.rx_dropped++; 465 continue; 466 } 467 468 skb->dev = port->dev; 469 if (port->type == HSR_PT_MASTER) { 470 hsr_deliver_master(skb, port->dev, frame->node_src); 471 } else { 472 if (!hsr_xmit(skb, port, frame)) 473 sent = true; 474 } 475 } 476 } 477 478 static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb, 479 struct hsr_frame_info *frame) 480 { 481 if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) { 482 frame->is_local_exclusive = true; 483 skb->pkt_type = PACKET_HOST; 484 } else { 485 frame->is_local_exclusive = false; 486 } 487 488 if (skb->pkt_type == PACKET_HOST || 489 skb->pkt_type == PACKET_MULTICAST || 490 skb->pkt_type == PACKET_BROADCAST) { 491 frame->is_local_dest = true; 492 } else { 493 frame->is_local_dest = false; 494 } 495 } 496 497 static void handle_std_frame(struct sk_buff *skb, 498 struct hsr_frame_info *frame) 499 { 500 struct hsr_port *port = frame->port_rcv; 501 struct hsr_priv *hsr = port->hsr; 502 unsigned long irqflags; 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 spin_lock_irqsave(&hsr->seqnr_lock, irqflags); 513 frame->sequence_nr = hsr->sequence_nr; 514 hsr->sequence_nr++; 515 spin_unlock_irqrestore(&hsr->seqnr_lock, irqflags); 516 } 517 } 518 519 int hsr_fill_frame_info(__be16 proto, struct sk_buff *skb, 520 struct hsr_frame_info *frame) 521 { 522 struct hsr_port *port = frame->port_rcv; 523 struct hsr_priv *hsr = port->hsr; 524 525 /* HSRv0 supervisory frames double as a tag so treat them as tagged. */ 526 if ((!hsr->prot_version && proto == htons(ETH_P_PRP)) || 527 proto == htons(ETH_P_HSR)) { 528 /* Check if skb contains hsr_ethhdr */ 529 if (skb->mac_len < sizeof(struct hsr_ethhdr)) 530 return -EINVAL; 531 532 /* HSR tagged frame :- Data or Supervision */ 533 frame->skb_std = NULL; 534 frame->skb_prp = NULL; 535 frame->skb_hsr = skb; 536 frame->sequence_nr = hsr_get_skb_sequence_nr(skb); 537 return 0; 538 } 539 540 /* Standard frame or PRP from master port */ 541 handle_std_frame(skb, frame); 542 543 return 0; 544 } 545 546 int prp_fill_frame_info(__be16 proto, struct sk_buff *skb, 547 struct hsr_frame_info *frame) 548 { 549 /* Supervision frame */ 550 struct prp_rct *rct = skb_get_PRP_rct(skb); 551 552 if (rct && 553 prp_check_lsdu_size(skb, rct, frame->is_supervision)) { 554 frame->skb_hsr = NULL; 555 frame->skb_std = NULL; 556 frame->skb_prp = skb; 557 frame->sequence_nr = prp_get_skb_sequence_nr(rct); 558 return 0; 559 } 560 handle_std_frame(skb, frame); 561 562 return 0; 563 } 564 565 static int fill_frame_info(struct hsr_frame_info *frame, 566 struct sk_buff *skb, struct hsr_port *port) 567 { 568 struct hsr_priv *hsr = port->hsr; 569 struct hsr_vlan_ethhdr *vlan_hdr; 570 struct ethhdr *ethhdr; 571 __be16 proto; 572 int ret; 573 574 /* Check if skb contains ethhdr */ 575 if (skb->mac_len < sizeof(struct ethhdr)) 576 return -EINVAL; 577 578 memset(frame, 0, sizeof(*frame)); 579 frame->is_supervision = is_supervision_frame(port->hsr, skb); 580 frame->node_src = hsr_get_node(port, &hsr->node_db, skb, 581 frame->is_supervision, 582 port->type); 583 if (!frame->node_src) 584 return -1; /* Unknown node and !is_supervision, or no mem */ 585 586 ethhdr = (struct ethhdr *)skb_mac_header(skb); 587 frame->is_vlan = false; 588 proto = ethhdr->h_proto; 589 590 if (proto == htons(ETH_P_8021Q)) 591 frame->is_vlan = true; 592 593 if (frame->is_vlan) { 594 vlan_hdr = (struct hsr_vlan_ethhdr *)ethhdr; 595 proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto; 596 /* FIXME: */ 597 netdev_warn_once(skb->dev, "VLAN not yet supported"); 598 } 599 600 frame->is_from_san = false; 601 frame->port_rcv = port; 602 ret = hsr->proto_ops->fill_frame_info(proto, skb, frame); 603 if (ret) 604 return ret; 605 606 check_local_dest(port->hsr, skb, frame); 607 608 return 0; 609 } 610 611 /* Must be called holding rcu read lock (because of the port parameter) */ 612 void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port) 613 { 614 struct hsr_frame_info frame; 615 616 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 /* Gets called for ingress frames as well as egress from master port. 622 * So check and increment stats for master port only here. 623 */ 624 if (port->type == HSR_PT_MASTER) { 625 port->dev->stats.tx_packets++; 626 port->dev->stats.tx_bytes += skb->len; 627 } 628 629 kfree_skb(frame.skb_hsr); 630 kfree_skb(frame.skb_prp); 631 kfree_skb(frame.skb_std); 632 return; 633 634 out_drop: 635 port->dev->stats.tx_dropped++; 636 kfree_skb(skb); 637 } 638