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 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 78 static 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 } 106 107 struct 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 /* Unexpected */ 116 WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n", 117 __FILE__, __LINE__, port->dev->name); 118 return NULL; 119 } 120 } 121 122 return skb_clone(frame->skb_std, GFP_ATOMIC); 123 } 124 125 struct 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 } 147 148 static 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 */ 164 static 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 } 193 194 static 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 } 206 207 static 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 */ 238 struct 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 } else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) { 253 return skb_clone(frame->skb_std, GFP_ATOMIC); 254 } 255 256 /* Create the new skb with enough headroom to fit the HSR tag */ 257 skb = __pskb_copy(frame->skb_std, 258 skb_headroom(frame->skb_std) + HSR_HLEN, GFP_ATOMIC); 259 if (!skb) 260 return NULL; 261 skb_reset_mac_header(skb); 262 263 if (skb->ip_summed == CHECKSUM_PARTIAL) 264 skb->csum_start += HSR_HLEN; 265 266 movelen = ETH_HLEN; 267 if (frame->is_vlan) 268 movelen += VLAN_HLEN; 269 270 src = skb_mac_header(skb); 271 dst = skb_push(skb, HSR_HLEN); 272 memmove(dst, src, movelen); 273 skb_reset_mac_header(skb); 274 275 /* skb_put_padto free skb on error and hsr_fill_tag returns NULL in 276 * that case 277 */ 278 return hsr_fill_tag(skb, frame, port, port->hsr->prot_version); 279 } 280 281 struct sk_buff *prp_create_tagged_frame(struct hsr_frame_info *frame, 282 struct hsr_port *port) 283 { 284 struct sk_buff *skb; 285 286 if (frame->skb_prp) { 287 struct prp_rct *trailer = skb_get_PRP_rct(frame->skb_prp); 288 289 if (trailer) { 290 prp_set_lan_id(trailer, port); 291 } else { 292 WARN_ONCE(!trailer, "errored PRP skb"); 293 return NULL; 294 } 295 return skb_clone(frame->skb_prp, GFP_ATOMIC); 296 } else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) { 297 return skb_clone(frame->skb_std, GFP_ATOMIC); 298 } 299 300 skb = skb_copy_expand(frame->skb_std, 0, 301 skb_tailroom(frame->skb_std) + HSR_HLEN, 302 GFP_ATOMIC); 303 prp_fill_rct(skb, frame, port); 304 305 return skb; 306 } 307 308 static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev, 309 struct hsr_node *node_src) 310 { 311 bool was_multicast_frame; 312 int res; 313 314 was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST); 315 hsr_addr_subst_source(node_src, skb); 316 skb_pull(skb, ETH_HLEN); 317 res = netif_rx(skb); 318 if (res == NET_RX_DROP) { 319 dev->stats.rx_dropped++; 320 } else { 321 dev->stats.rx_packets++; 322 dev->stats.rx_bytes += skb->len; 323 if (was_multicast_frame) 324 dev->stats.multicast++; 325 } 326 } 327 328 static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port, 329 struct hsr_frame_info *frame) 330 { 331 if (frame->port_rcv->type == HSR_PT_MASTER) { 332 hsr_addr_subst_dest(frame->node_src, skb, port); 333 334 /* Address substitution (IEC62439-3 pp 26, 50): replace mac 335 * address of outgoing frame with that of the outgoing slave's. 336 */ 337 ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr); 338 } 339 return dev_queue_xmit(skb); 340 } 341 342 bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port) 343 { 344 return ((frame->port_rcv->type == HSR_PT_SLAVE_A && 345 port->type == HSR_PT_SLAVE_B) || 346 (frame->port_rcv->type == HSR_PT_SLAVE_B && 347 port->type == HSR_PT_SLAVE_A)); 348 } 349 350 bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port) 351 { 352 if (port->dev->features & NETIF_F_HW_HSR_FWD) 353 return prp_drop_frame(frame, port); 354 355 return false; 356 } 357 358 /* Forward the frame through all devices except: 359 * - Back through the receiving device 360 * - If it's a HSR frame: through a device where it has passed before 361 * - if it's a PRP frame: through another PRP slave device (no bridge) 362 * - To the local HSR master only if the frame is directly addressed to it, or 363 * a non-supervision multicast or broadcast frame. 364 * 365 * HSR slave devices should insert a HSR tag into the frame, or forward the 366 * frame unchanged if it's already tagged. Interlink devices should strip HSR 367 * tags if they're of the non-HSR type (but only after duplicate discard). The 368 * master device always strips HSR tags. 369 */ 370 static void hsr_forward_do(struct hsr_frame_info *frame) 371 { 372 struct hsr_port *port; 373 struct sk_buff *skb; 374 bool sent = false; 375 376 hsr_for_each_port(frame->port_rcv->hsr, port) { 377 struct hsr_priv *hsr = port->hsr; 378 /* Don't send frame back the way it came */ 379 if (port == frame->port_rcv) 380 continue; 381 382 /* Don't deliver locally unless we should */ 383 if (port->type == HSR_PT_MASTER && !frame->is_local_dest) 384 continue; 385 386 /* Deliver frames directly addressed to us to master only */ 387 if (port->type != HSR_PT_MASTER && frame->is_local_exclusive) 388 continue; 389 390 /* If hardware duplicate generation is enabled, only send out 391 * one port. 392 */ 393 if ((port->dev->features & NETIF_F_HW_HSR_DUP) && sent) 394 continue; 395 396 /* Don't send frame over port where it has been sent before. 397 * Also fro SAN, this shouldn't be done. 398 */ 399 if (!frame->is_from_san && 400 hsr_register_frame_out(port, frame->node_src, 401 frame->sequence_nr)) 402 continue; 403 404 if (frame->is_supervision && port->type == HSR_PT_MASTER) { 405 hsr_handle_sup_frame(frame); 406 continue; 407 } 408 409 /* Check if frame is to be dropped. Eg. for PRP no forward 410 * between ports. 411 */ 412 if (hsr->proto_ops->drop_frame && 413 hsr->proto_ops->drop_frame(frame, port)) 414 continue; 415 416 if (port->type != HSR_PT_MASTER) 417 skb = hsr->proto_ops->create_tagged_frame(frame, port); 418 else 419 skb = hsr->proto_ops->get_untagged_frame(frame, port); 420 421 if (!skb) { 422 frame->port_rcv->dev->stats.rx_dropped++; 423 continue; 424 } 425 426 skb->dev = port->dev; 427 if (port->type == HSR_PT_MASTER) { 428 hsr_deliver_master(skb, port->dev, frame->node_src); 429 } else { 430 if (!hsr_xmit(skb, port, frame)) 431 sent = true; 432 } 433 } 434 } 435 436 static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb, 437 struct hsr_frame_info *frame) 438 { 439 if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) { 440 frame->is_local_exclusive = true; 441 skb->pkt_type = PACKET_HOST; 442 } else { 443 frame->is_local_exclusive = false; 444 } 445 446 if (skb->pkt_type == PACKET_HOST || 447 skb->pkt_type == PACKET_MULTICAST || 448 skb->pkt_type == PACKET_BROADCAST) { 449 frame->is_local_dest = true; 450 } else { 451 frame->is_local_dest = false; 452 } 453 } 454 455 static void handle_std_frame(struct sk_buff *skb, 456 struct hsr_frame_info *frame) 457 { 458 struct hsr_port *port = frame->port_rcv; 459 struct hsr_priv *hsr = port->hsr; 460 unsigned long irqflags; 461 462 frame->skb_hsr = NULL; 463 frame->skb_prp = NULL; 464 frame->skb_std = skb; 465 466 if (port->type != HSR_PT_MASTER) { 467 frame->is_from_san = true; 468 } else { 469 /* Sequence nr for the master node */ 470 spin_lock_irqsave(&hsr->seqnr_lock, irqflags); 471 frame->sequence_nr = hsr->sequence_nr; 472 hsr->sequence_nr++; 473 spin_unlock_irqrestore(&hsr->seqnr_lock, irqflags); 474 } 475 } 476 477 void hsr_fill_frame_info(__be16 proto, struct sk_buff *skb, 478 struct hsr_frame_info *frame) 479 { 480 struct hsr_port *port = frame->port_rcv; 481 struct hsr_priv *hsr = port->hsr; 482 483 /* HSRv0 supervisory frames double as a tag so treat them as tagged. */ 484 if ((!hsr->prot_version && proto == htons(ETH_P_PRP)) || 485 proto == htons(ETH_P_HSR)) { 486 /* HSR tagged frame :- Data or Supervision */ 487 frame->skb_std = NULL; 488 frame->skb_prp = NULL; 489 frame->skb_hsr = skb; 490 frame->sequence_nr = hsr_get_skb_sequence_nr(skb); 491 return; 492 } 493 494 /* Standard frame or PRP from master port */ 495 handle_std_frame(skb, frame); 496 } 497 498 void prp_fill_frame_info(__be16 proto, struct sk_buff *skb, 499 struct hsr_frame_info *frame) 500 { 501 /* Supervision frame */ 502 struct prp_rct *rct = skb_get_PRP_rct(skb); 503 504 if (rct && 505 prp_check_lsdu_size(skb, rct, frame->is_supervision)) { 506 frame->skb_hsr = NULL; 507 frame->skb_std = NULL; 508 frame->skb_prp = skb; 509 frame->sequence_nr = prp_get_skb_sequence_nr(rct); 510 return; 511 } 512 handle_std_frame(skb, frame); 513 } 514 515 static int fill_frame_info(struct hsr_frame_info *frame, 516 struct sk_buff *skb, struct hsr_port *port) 517 { 518 struct hsr_priv *hsr = port->hsr; 519 struct hsr_vlan_ethhdr *vlan_hdr; 520 struct ethhdr *ethhdr; 521 __be16 proto; 522 523 memset(frame, 0, sizeof(*frame)); 524 frame->is_supervision = is_supervision_frame(port->hsr, skb); 525 frame->node_src = hsr_get_node(port, &hsr->node_db, skb, 526 frame->is_supervision, 527 port->type); 528 if (!frame->node_src) 529 return -1; /* Unknown node and !is_supervision, or no mem */ 530 531 ethhdr = (struct ethhdr *)skb_mac_header(skb); 532 frame->is_vlan = false; 533 proto = ethhdr->h_proto; 534 535 if (proto == htons(ETH_P_8021Q)) 536 frame->is_vlan = true; 537 538 if (frame->is_vlan) { 539 vlan_hdr = (struct hsr_vlan_ethhdr *)ethhdr; 540 proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto; 541 /* FIXME: */ 542 netdev_warn_once(skb->dev, "VLAN not yet supported"); 543 } 544 545 frame->is_from_san = false; 546 frame->port_rcv = port; 547 hsr->proto_ops->fill_frame_info(proto, skb, frame); 548 check_local_dest(port->hsr, skb, frame); 549 550 return 0; 551 } 552 553 /* Must be called holding rcu read lock (because of the port parameter) */ 554 void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port) 555 { 556 struct hsr_frame_info frame; 557 558 if (skb_mac_header(skb) != skb->data) { 559 WARN_ONCE(1, "%s:%d: Malformed frame (port_src %s)\n", 560 __FILE__, __LINE__, port->dev->name); 561 goto out_drop; 562 } 563 564 if (fill_frame_info(&frame, skb, port) < 0) 565 goto out_drop; 566 567 hsr_register_frame_in(frame.node_src, port, frame.sequence_nr); 568 hsr_forward_do(&frame); 569 /* Gets called for ingress frames as well as egress from master port. 570 * So check and increment stats for master port only here. 571 */ 572 if (port->type == HSR_PT_MASTER) { 573 port->dev->stats.tx_packets++; 574 port->dev->stats.tx_bytes += skb->len; 575 } 576 577 kfree_skb(frame.skb_hsr); 578 kfree_skb(frame.skb_prp); 579 kfree_skb(frame.skb_std); 580 return; 581 582 out_drop: 583 port->dev->stats.tx_dropped++; 584 kfree_skb(skb); 585 } 586