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