xref: /linux/net/hsr/hsr_forward.c (revision 55d0969c451159cff86949b38c39171cab962069)
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 += 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 bool is_proxy_supervision_frame(struct hsr_priv *hsr,
121 				       struct sk_buff *skb)
122 {
123 	struct hsr_sup_payload *payload;
124 	struct ethhdr *eth_hdr;
125 	u16 total_length = 0;
126 
127 	eth_hdr = (struct ethhdr *)skb_mac_header(skb);
128 
129 	/* Get the HSR protocol revision. */
130 	if (eth_hdr->h_proto == htons(ETH_P_HSR))
131 		total_length = sizeof(struct hsrv1_ethhdr_sp);
132 	else
133 		total_length = sizeof(struct hsrv0_ethhdr_sp);
134 
135 	if (!pskb_may_pull(skb, total_length + sizeof(struct hsr_sup_payload)))
136 		return false;
137 
138 	skb_pull(skb, total_length);
139 	payload = (struct hsr_sup_payload *)skb->data;
140 	skb_push(skb, total_length);
141 
142 	/* For RedBox (HSR-SAN) check if we have received the supervision
143 	 * frame with MAC addresses from own ProxyNodeTable.
144 	 */
145 	return hsr_is_node_in_db(&hsr->proxy_node_db,
146 				 payload->macaddress_A);
147 }
148 
149 static struct sk_buff *create_stripped_skb_hsr(struct sk_buff *skb_in,
150 					       struct hsr_frame_info *frame)
151 {
152 	struct sk_buff *skb;
153 	int copylen;
154 	unsigned char *dst, *src;
155 
156 	skb_pull(skb_in, HSR_HLEN);
157 	skb = __pskb_copy(skb_in, skb_headroom(skb_in) - HSR_HLEN, GFP_ATOMIC);
158 	skb_push(skb_in, HSR_HLEN);
159 	if (!skb)
160 		return NULL;
161 
162 	skb_reset_mac_header(skb);
163 
164 	if (skb->ip_summed == CHECKSUM_PARTIAL)
165 		skb->csum_start -= HSR_HLEN;
166 
167 	copylen = 2 * ETH_ALEN;
168 	if (frame->is_vlan)
169 		copylen += VLAN_HLEN;
170 	src = skb_mac_header(skb_in);
171 	dst = skb_mac_header(skb);
172 	memcpy(dst, src, copylen);
173 
174 	skb->protocol = eth_hdr(skb)->h_proto;
175 	return skb;
176 }
177 
178 struct sk_buff *hsr_get_untagged_frame(struct hsr_frame_info *frame,
179 				       struct hsr_port *port)
180 {
181 	if (!frame->skb_std) {
182 		if (frame->skb_hsr)
183 			frame->skb_std =
184 				create_stripped_skb_hsr(frame->skb_hsr, frame);
185 		else
186 			netdev_warn_once(port->dev,
187 					 "Unexpected frame received in hsr_get_untagged_frame()\n");
188 
189 		if (!frame->skb_std)
190 			return NULL;
191 	}
192 
193 	return skb_clone(frame->skb_std, GFP_ATOMIC);
194 }
195 
196 struct sk_buff *prp_get_untagged_frame(struct hsr_frame_info *frame,
197 				       struct hsr_port *port)
198 {
199 	if (!frame->skb_std) {
200 		if (frame->skb_prp) {
201 			/* trim the skb by len - HSR_HLEN to exclude RCT */
202 			skb_trim(frame->skb_prp,
203 				 frame->skb_prp->len - HSR_HLEN);
204 			frame->skb_std =
205 				__pskb_copy(frame->skb_prp,
206 					    skb_headroom(frame->skb_prp),
207 					    GFP_ATOMIC);
208 		} else {
209 			/* Unexpected */
210 			WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n",
211 				  __FILE__, __LINE__, port->dev->name);
212 			return NULL;
213 		}
214 	}
215 
216 	return skb_clone(frame->skb_std, GFP_ATOMIC);
217 }
218 
219 static void prp_set_lan_id(struct prp_rct *trailer,
220 			   struct hsr_port *port)
221 {
222 	int lane_id;
223 
224 	if (port->type == HSR_PT_SLAVE_A)
225 		lane_id = 0;
226 	else
227 		lane_id = 1;
228 
229 	/* Add net_id in the upper 3 bits of lane_id */
230 	lane_id |= port->hsr->net_id;
231 	set_prp_lan_id(trailer, lane_id);
232 }
233 
234 /* Tailroom for PRP rct should have been created before calling this */
235 static struct sk_buff *prp_fill_rct(struct sk_buff *skb,
236 				    struct hsr_frame_info *frame,
237 				    struct hsr_port *port)
238 {
239 	struct prp_rct *trailer;
240 	int min_size = ETH_ZLEN;
241 	int lsdu_size;
242 
243 	if (!skb)
244 		return skb;
245 
246 	if (frame->is_vlan)
247 		min_size = VLAN_ETH_ZLEN;
248 
249 	if (skb_put_padto(skb, min_size))
250 		return NULL;
251 
252 	trailer = (struct prp_rct *)skb_put(skb, HSR_HLEN);
253 	lsdu_size = skb->len - 14;
254 	if (frame->is_vlan)
255 		lsdu_size -= 4;
256 	prp_set_lan_id(trailer, port);
257 	set_prp_LSDU_size(trailer, lsdu_size);
258 	trailer->sequence_nr = htons(frame->sequence_nr);
259 	trailer->PRP_suffix = htons(ETH_P_PRP);
260 	skb->protocol = eth_hdr(skb)->h_proto;
261 
262 	return skb;
263 }
264 
265 static void hsr_set_path_id(struct hsr_ethhdr *hsr_ethhdr,
266 			    struct hsr_port *port)
267 {
268 	int path_id;
269 
270 	if (port->type == HSR_PT_SLAVE_A)
271 		path_id = 0;
272 	else
273 		path_id = 1;
274 
275 	set_hsr_tag_path(&hsr_ethhdr->hsr_tag, path_id);
276 }
277 
278 static struct sk_buff *hsr_fill_tag(struct sk_buff *skb,
279 				    struct hsr_frame_info *frame,
280 				    struct hsr_port *port, u8 proto_version)
281 {
282 	struct hsr_ethhdr *hsr_ethhdr;
283 	int lsdu_size;
284 
285 	/* pad to minimum packet size which is 60 + 6 (HSR tag) */
286 	if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
287 		return NULL;
288 
289 	lsdu_size = skb->len - 14;
290 	if (frame->is_vlan)
291 		lsdu_size -= 4;
292 
293 	hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(skb);
294 
295 	hsr_set_path_id(hsr_ethhdr, port);
296 	set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size);
297 	hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr);
298 	hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
299 	hsr_ethhdr->ethhdr.h_proto = htons(proto_version ?
300 			ETH_P_HSR : ETH_P_PRP);
301 	skb->protocol = hsr_ethhdr->ethhdr.h_proto;
302 
303 	return skb;
304 }
305 
306 /* If the original frame was an HSR tagged frame, just clone it to be sent
307  * unchanged. Otherwise, create a private frame especially tagged for 'port'.
308  */
309 struct sk_buff *hsr_create_tagged_frame(struct hsr_frame_info *frame,
310 					struct hsr_port *port)
311 {
312 	unsigned char *dst, *src;
313 	struct sk_buff *skb;
314 	int movelen;
315 
316 	if (frame->skb_hsr) {
317 		struct hsr_ethhdr *hsr_ethhdr =
318 			(struct hsr_ethhdr *)skb_mac_header(frame->skb_hsr);
319 
320 		/* set the lane id properly */
321 		hsr_set_path_id(hsr_ethhdr, port);
322 		return skb_clone(frame->skb_hsr, GFP_ATOMIC);
323 	} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
324 		return skb_clone(frame->skb_std, GFP_ATOMIC);
325 	}
326 
327 	/* Create the new skb with enough headroom to fit the HSR tag */
328 	skb = __pskb_copy(frame->skb_std,
329 			  skb_headroom(frame->skb_std) + HSR_HLEN, GFP_ATOMIC);
330 	if (!skb)
331 		return NULL;
332 	skb_reset_mac_header(skb);
333 
334 	if (skb->ip_summed == CHECKSUM_PARTIAL)
335 		skb->csum_start += HSR_HLEN;
336 
337 	movelen = ETH_HLEN;
338 	if (frame->is_vlan)
339 		movelen += VLAN_HLEN;
340 
341 	src = skb_mac_header(skb);
342 	dst = skb_push(skb, HSR_HLEN);
343 	memmove(dst, src, movelen);
344 	skb_reset_mac_header(skb);
345 
346 	/* skb_put_padto free skb on error and hsr_fill_tag returns NULL in
347 	 * that case
348 	 */
349 	return hsr_fill_tag(skb, frame, port, port->hsr->prot_version);
350 }
351 
352 struct sk_buff *prp_create_tagged_frame(struct hsr_frame_info *frame,
353 					struct hsr_port *port)
354 {
355 	struct sk_buff *skb;
356 
357 	if (frame->skb_prp) {
358 		struct prp_rct *trailer = skb_get_PRP_rct(frame->skb_prp);
359 
360 		if (trailer) {
361 			prp_set_lan_id(trailer, port);
362 		} else {
363 			WARN_ONCE(!trailer, "errored PRP skb");
364 			return NULL;
365 		}
366 		return skb_clone(frame->skb_prp, GFP_ATOMIC);
367 	} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
368 		return skb_clone(frame->skb_std, GFP_ATOMIC);
369 	}
370 
371 	skb = skb_copy_expand(frame->skb_std, 0,
372 			      skb_tailroom(frame->skb_std) + HSR_HLEN,
373 			      GFP_ATOMIC);
374 	return prp_fill_rct(skb, frame, port);
375 }
376 
377 static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev,
378 			       struct hsr_node *node_src)
379 {
380 	bool was_multicast_frame;
381 	int res, recv_len;
382 
383 	was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST);
384 	hsr_addr_subst_source(node_src, skb);
385 	skb_pull(skb, ETH_HLEN);
386 	recv_len = skb->len;
387 	res = netif_rx(skb);
388 	if (res == NET_RX_DROP) {
389 		dev->stats.rx_dropped++;
390 	} else {
391 		dev->stats.rx_packets++;
392 		dev->stats.rx_bytes += recv_len;
393 		if (was_multicast_frame)
394 			dev->stats.multicast++;
395 	}
396 }
397 
398 static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port,
399 		    struct hsr_frame_info *frame)
400 {
401 	if (frame->port_rcv->type == HSR_PT_MASTER) {
402 		hsr_addr_subst_dest(frame->node_src, skb, port);
403 
404 		/* Address substitution (IEC62439-3 pp 26, 50): replace mac
405 		 * address of outgoing frame with that of the outgoing slave's.
406 		 */
407 		ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr);
408 	}
409 
410 	/* When HSR node is used as RedBox - the frame received from HSR ring
411 	 * requires source MAC address (SA) replacement to one which can be
412 	 * recognized by SAN devices (otherwise, frames are dropped by switch)
413 	 */
414 	if (port->type == HSR_PT_INTERLINK)
415 		ether_addr_copy(eth_hdr(skb)->h_source,
416 				port->hsr->macaddress_redbox);
417 
418 	return dev_queue_xmit(skb);
419 }
420 
421 bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
422 {
423 	return ((frame->port_rcv->type == HSR_PT_SLAVE_A &&
424 		 port->type == HSR_PT_SLAVE_B) ||
425 		(frame->port_rcv->type == HSR_PT_SLAVE_B &&
426 		 port->type == HSR_PT_SLAVE_A));
427 }
428 
429 bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
430 {
431 	struct sk_buff *skb;
432 
433 	if (port->dev->features & NETIF_F_HW_HSR_FWD)
434 		return prp_drop_frame(frame, port);
435 
436 	/* RedBox specific frames dropping policies
437 	 *
438 	 * Do not send HSR supervisory frames to SAN devices
439 	 */
440 	if (frame->is_supervision && port->type == HSR_PT_INTERLINK)
441 		return true;
442 
443 	/* Do not forward to other HSR port (A or B) unicast frames which
444 	 * are addressed to interlink port (and are in the ProxyNodeTable).
445 	 */
446 	skb = frame->skb_hsr;
447 	if (skb && prp_drop_frame(frame, port) &&
448 	    is_unicast_ether_addr(eth_hdr(skb)->h_dest) &&
449 	    hsr_is_node_in_db(&port->hsr->proxy_node_db,
450 			      eth_hdr(skb)->h_dest)) {
451 		return true;
452 	}
453 
454 	/* Do not forward to port C (Interlink) frames from nodes A and B
455 	 * if DA is in NodeTable.
456 	 */
457 	if ((frame->port_rcv->type == HSR_PT_SLAVE_A ||
458 	     frame->port_rcv->type == HSR_PT_SLAVE_B) &&
459 	    port->type == HSR_PT_INTERLINK) {
460 		skb = frame->skb_hsr;
461 		if (skb && is_unicast_ether_addr(eth_hdr(skb)->h_dest) &&
462 		    hsr_is_node_in_db(&port->hsr->node_db,
463 				      eth_hdr(skb)->h_dest)) {
464 			return true;
465 		}
466 	}
467 
468 	/* Do not forward to port A and B unicast frames received on the
469 	 * interlink port if it is addressed to one of nodes registered in
470 	 * the ProxyNodeTable.
471 	 */
472 	if ((port->type == HSR_PT_SLAVE_A || port->type == HSR_PT_SLAVE_B) &&
473 	    frame->port_rcv->type == HSR_PT_INTERLINK) {
474 		skb = frame->skb_std;
475 		if (skb && is_unicast_ether_addr(eth_hdr(skb)->h_dest) &&
476 		    hsr_is_node_in_db(&port->hsr->proxy_node_db,
477 				      eth_hdr(skb)->h_dest)) {
478 			return true;
479 		}
480 	}
481 
482 	return false;
483 }
484 
485 /* Forward the frame through all devices except:
486  * - Back through the receiving device
487  * - If it's a HSR frame: through a device where it has passed before
488  * - if it's a PRP frame: through another PRP slave device (no bridge)
489  * - To the local HSR master only if the frame is directly addressed to it, or
490  *   a non-supervision multicast or broadcast frame.
491  *
492  * HSR slave devices should insert a HSR tag into the frame, or forward the
493  * frame unchanged if it's already tagged. Interlink devices should strip HSR
494  * tags if they're of the non-HSR type (but only after duplicate discard). The
495  * master device always strips HSR tags.
496  */
497 static void hsr_forward_do(struct hsr_frame_info *frame)
498 {
499 	struct hsr_port *port;
500 	struct sk_buff *skb;
501 	bool sent = false;
502 
503 	hsr_for_each_port(frame->port_rcv->hsr, port) {
504 		struct hsr_priv *hsr = port->hsr;
505 		/* Don't send frame back the way it came */
506 		if (port == frame->port_rcv)
507 			continue;
508 
509 		/* Don't deliver locally unless we should */
510 		if (port->type == HSR_PT_MASTER && !frame->is_local_dest)
511 			continue;
512 
513 		/* Deliver frames directly addressed to us to master only */
514 		if (port->type != HSR_PT_MASTER && frame->is_local_exclusive)
515 			continue;
516 
517 		/* If hardware duplicate generation is enabled, only send out
518 		 * one port.
519 		 */
520 		if ((port->dev->features & NETIF_F_HW_HSR_DUP) && sent)
521 			continue;
522 
523 		/* Don't send frame over port where it has been sent before.
524 		 * Also for SAN, this shouldn't be done.
525 		 */
526 		if (!frame->is_from_san &&
527 		    hsr_register_frame_out(port, frame->node_src,
528 					   frame->sequence_nr))
529 			continue;
530 
531 		if (frame->is_supervision && port->type == HSR_PT_MASTER &&
532 		    !frame->is_proxy_supervision) {
533 			hsr_handle_sup_frame(frame);
534 			continue;
535 		}
536 
537 		/* Check if frame is to be dropped. Eg. for PRP no forward
538 		 * between ports, or sending HSR supervision to RedBox.
539 		 */
540 		if (hsr->proto_ops->drop_frame &&
541 		    hsr->proto_ops->drop_frame(frame, port))
542 			continue;
543 
544 		if (port->type == HSR_PT_SLAVE_A ||
545 		    port->type == HSR_PT_SLAVE_B)
546 			skb = hsr->proto_ops->create_tagged_frame(frame, port);
547 		else
548 			skb = hsr->proto_ops->get_untagged_frame(frame, port);
549 
550 		if (!skb) {
551 			frame->port_rcv->dev->stats.rx_dropped++;
552 			continue;
553 		}
554 
555 		skb->dev = port->dev;
556 		if (port->type == HSR_PT_MASTER) {
557 			hsr_deliver_master(skb, port->dev, frame->node_src);
558 		} else {
559 			if (!hsr_xmit(skb, port, frame))
560 				if (port->type == HSR_PT_SLAVE_A ||
561 				    port->type == HSR_PT_SLAVE_B)
562 					sent = true;
563 		}
564 	}
565 }
566 
567 static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb,
568 			     struct hsr_frame_info *frame)
569 {
570 	if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) {
571 		frame->is_local_exclusive = true;
572 		skb->pkt_type = PACKET_HOST;
573 	} else {
574 		frame->is_local_exclusive = false;
575 	}
576 
577 	if (skb->pkt_type == PACKET_HOST ||
578 	    skb->pkt_type == PACKET_MULTICAST ||
579 	    skb->pkt_type == PACKET_BROADCAST) {
580 		frame->is_local_dest = true;
581 	} else {
582 		frame->is_local_dest = false;
583 	}
584 }
585 
586 static void handle_std_frame(struct sk_buff *skb,
587 			     struct hsr_frame_info *frame)
588 {
589 	struct hsr_port *port = frame->port_rcv;
590 	struct hsr_priv *hsr = port->hsr;
591 
592 	frame->skb_hsr = NULL;
593 	frame->skb_prp = NULL;
594 	frame->skb_std = skb;
595 
596 	if (port->type != HSR_PT_MASTER)
597 		frame->is_from_san = true;
598 
599 	if (port->type == HSR_PT_MASTER ||
600 	    port->type == HSR_PT_INTERLINK) {
601 		/* Sequence nr for the master/interlink node */
602 		lockdep_assert_held(&hsr->seqnr_lock);
603 		frame->sequence_nr = hsr->sequence_nr;
604 		hsr->sequence_nr++;
605 	}
606 }
607 
608 int hsr_fill_frame_info(__be16 proto, struct sk_buff *skb,
609 			struct hsr_frame_info *frame)
610 {
611 	struct hsr_port *port = frame->port_rcv;
612 	struct hsr_priv *hsr = port->hsr;
613 
614 	/* HSRv0 supervisory frames double as a tag so treat them as tagged. */
615 	if ((!hsr->prot_version && proto == htons(ETH_P_PRP)) ||
616 	    proto == htons(ETH_P_HSR)) {
617 		/* Check if skb contains hsr_ethhdr */
618 		if (skb->mac_len < sizeof(struct hsr_ethhdr))
619 			return -EINVAL;
620 
621 		/* HSR tagged frame :- Data or Supervision */
622 		frame->skb_std = NULL;
623 		frame->skb_prp = NULL;
624 		frame->skb_hsr = skb;
625 		frame->sequence_nr = hsr_get_skb_sequence_nr(skb);
626 		return 0;
627 	}
628 
629 	/* Standard frame or PRP from master port */
630 	handle_std_frame(skb, frame);
631 
632 	return 0;
633 }
634 
635 int prp_fill_frame_info(__be16 proto, struct sk_buff *skb,
636 			struct hsr_frame_info *frame)
637 {
638 	/* Supervision frame */
639 	struct prp_rct *rct = skb_get_PRP_rct(skb);
640 
641 	if (rct &&
642 	    prp_check_lsdu_size(skb, rct, frame->is_supervision)) {
643 		frame->skb_hsr = NULL;
644 		frame->skb_std = NULL;
645 		frame->skb_prp = skb;
646 		frame->sequence_nr = prp_get_skb_sequence_nr(rct);
647 		return 0;
648 	}
649 	handle_std_frame(skb, frame);
650 
651 	return 0;
652 }
653 
654 static int fill_frame_info(struct hsr_frame_info *frame,
655 			   struct sk_buff *skb, struct hsr_port *port)
656 {
657 	struct hsr_priv *hsr = port->hsr;
658 	struct hsr_vlan_ethhdr *vlan_hdr;
659 	struct list_head *n_db;
660 	struct ethhdr *ethhdr;
661 	__be16 proto;
662 	int ret;
663 
664 	/* Check if skb contains ethhdr */
665 	if (skb->mac_len < sizeof(struct ethhdr))
666 		return -EINVAL;
667 
668 	memset(frame, 0, sizeof(*frame));
669 	frame->is_supervision = is_supervision_frame(port->hsr, skb);
670 	if (frame->is_supervision && hsr->redbox)
671 		frame->is_proxy_supervision =
672 			is_proxy_supervision_frame(port->hsr, skb);
673 
674 	n_db = &hsr->node_db;
675 	if (port->type == HSR_PT_INTERLINK)
676 		n_db = &hsr->proxy_node_db;
677 
678 	frame->node_src = hsr_get_node(port, n_db, skb,
679 				       frame->is_supervision, port->type);
680 	if (!frame->node_src)
681 		return -1; /* Unknown node and !is_supervision, or no mem */
682 
683 	ethhdr = (struct ethhdr *)skb_mac_header(skb);
684 	frame->is_vlan = false;
685 	proto = ethhdr->h_proto;
686 
687 	if (proto == htons(ETH_P_8021Q))
688 		frame->is_vlan = true;
689 
690 	if (frame->is_vlan) {
691 		vlan_hdr = (struct hsr_vlan_ethhdr *)ethhdr;
692 		proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto;
693 		/* FIXME: */
694 		netdev_warn_once(skb->dev, "VLAN not yet supported");
695 		return -EINVAL;
696 	}
697 
698 	frame->is_from_san = false;
699 	frame->port_rcv = port;
700 	ret = hsr->proto_ops->fill_frame_info(proto, skb, frame);
701 	if (ret)
702 		return ret;
703 
704 	check_local_dest(port->hsr, skb, frame);
705 
706 	return 0;
707 }
708 
709 /* Must be called holding rcu read lock (because of the port parameter) */
710 void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
711 {
712 	struct hsr_frame_info frame;
713 
714 	rcu_read_lock();
715 	if (fill_frame_info(&frame, skb, port) < 0)
716 		goto out_drop;
717 
718 	hsr_register_frame_in(frame.node_src, port, frame.sequence_nr);
719 	hsr_forward_do(&frame);
720 	rcu_read_unlock();
721 	/* Gets called for ingress frames as well as egress from master port.
722 	 * So check and increment stats for master port only here.
723 	 */
724 	if (port->type == HSR_PT_MASTER || port->type == HSR_PT_INTERLINK) {
725 		port->dev->stats.tx_packets++;
726 		port->dev->stats.tx_bytes += skb->len;
727 	}
728 
729 	kfree_skb(frame.skb_hsr);
730 	kfree_skb(frame.skb_prp);
731 	kfree_skb(frame.skb_std);
732 	return;
733 
734 out_drop:
735 	rcu_read_unlock();
736 	port->dev->stats.tx_dropped++;
737 	kfree_skb(skb);
738 }
739