hsr_forward.c

  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	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
120static 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
149static 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
178struct 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
196struct 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			if (!frame->skb_std)
209				return NULL;
210		} else {
211			/* Unexpected */
212			WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n",
213				  __FILE__, __LINE__, port->dev->name);
214			return NULL;
215		}
216	}
217
218	return skb_clone(frame->skb_std, GFP_ATOMIC);
219}
220
221static void prp_set_lan_id(struct prp_rct *trailer,
222			   struct hsr_port *port)
223{
224	int lane_id;
225
226	if (port->type == HSR_PT_SLAVE_A)
227		lane_id = 0;
228	else
229		lane_id = 1;
230
231	/* Add net_id in the upper 3 bits of lane_id */
232	lane_id |= port->hsr->net_id;
233	set_prp_lan_id(trailer, lane_id);
234}
235
236/* Tailroom for PRP rct should have been created before calling this */
237static struct sk_buff *prp_fill_rct(struct sk_buff *skb,
238				    struct hsr_frame_info *frame,
239				    struct hsr_port *port)
240{
241	struct prp_rct *trailer;
242	int min_size = ETH_ZLEN;
243	int lsdu_size;
244
245	if (!skb)
246		return skb;
247
248	if (frame->is_vlan)
249		min_size = VLAN_ETH_ZLEN;
250
251	if (skb_put_padto(skb, min_size))
252		return NULL;
253
254	trailer = (struct prp_rct *)skb_put(skb, HSR_HLEN);
255	lsdu_size = skb->len - 14;
256	if (frame->is_vlan)
257		lsdu_size -= 4;
258	prp_set_lan_id(trailer, port);
259	set_prp_LSDU_size(trailer, lsdu_size);
260	trailer->sequence_nr = htons(frame->sequence_nr);
261	trailer->PRP_suffix = htons(ETH_P_PRP);
262	skb->protocol = eth_hdr(skb)->h_proto;
263
264	return skb;
265}
266
267static void hsr_set_path_id(struct hsr_frame_info *frame,
268			    struct hsr_ethhdr *hsr_ethhdr,
269			    struct hsr_port *port)
270{
271	int path_id;
272
273	if (port->hsr->prot_version) {
274		if (port->type == HSR_PT_SLAVE_A)
275			path_id = 0;
276		else
277			path_id = 1;
278	} else {
279		if (frame->is_supervision)
280			path_id = 0xf;
281		else
282			path_id = 1;
283	}
284
285	set_hsr_tag_path(&hsr_ethhdr->hsr_tag, path_id);
286}
287
288static struct sk_buff *hsr_fill_tag(struct sk_buff *skb,
289				    struct hsr_frame_info *frame,
290				    struct hsr_port *port, u8 proto_version)
291{
292	struct hsr_ethhdr *hsr_ethhdr;
293	unsigned char *pc;
294	int lsdu_size;
295
296	/* pad to minimum packet size which is 60 + 6 (HSR tag) */
297	if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
298		return NULL;
299
300	lsdu_size = skb->len - 14;
301	if (frame->is_vlan)
302		lsdu_size -= 4;
303
304	pc = skb_mac_header(skb);
305	if (frame->is_vlan)
306		/* This 4-byte shift (size of a vlan tag) does not
307		 * mean that the ethhdr starts there. But rather it
308		 * provides the proper environment for accessing
309		 * the fields, such as hsr_tag etc., just like
310		 * when the vlan tag is not there. This is because
311		 * the hsr tag is after the vlan tag.
312		 */
313		hsr_ethhdr = (struct hsr_ethhdr *)(pc + VLAN_HLEN);
314	else
315		hsr_ethhdr = (struct hsr_ethhdr *)pc;
316
317	hsr_set_path_id(frame, hsr_ethhdr, port);
318	set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size);
319	hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr);
320	hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
321	hsr_ethhdr->ethhdr.h_proto = htons(proto_version ?
322			ETH_P_HSR : ETH_P_PRP);
323	skb->protocol = hsr_ethhdr->ethhdr.h_proto;
324
325	return skb;
326}
327
328/* If the original frame was an HSR tagged frame, just clone it to be sent
329 * unchanged. Otherwise, create a private frame especially tagged for 'port'.
330 */
331struct sk_buff *hsr_create_tagged_frame(struct hsr_frame_info *frame,
332					struct hsr_port *port)
333{
334	unsigned char *dst, *src;
335	struct sk_buff *skb;
336	int movelen;
337
338	if (frame->skb_hsr) {
339		struct hsr_ethhdr *hsr_ethhdr =
340			(struct hsr_ethhdr *)skb_mac_header(frame->skb_hsr);
341
342		/* set the lane id properly */
343		hsr_set_path_id(frame, hsr_ethhdr, port);
344		return skb_clone(frame->skb_hsr, GFP_ATOMIC);
345	} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
346		return skb_clone(frame->skb_std, GFP_ATOMIC);
347	}
348
349	/* Create the new skb with enough headroom to fit the HSR tag */
350	skb = __pskb_copy(frame->skb_std,
351			  skb_headroom(frame->skb_std) + HSR_HLEN, GFP_ATOMIC);
352	if (!skb)
353		return NULL;
354	skb_reset_mac_header(skb);
355
356	if (skb->ip_summed == CHECKSUM_PARTIAL)
357		skb->csum_start += HSR_HLEN;
358
359	movelen = ETH_HLEN;
360	if (frame->is_vlan)
361		movelen += VLAN_HLEN;
362
363	src = skb_mac_header(skb);
364	dst = skb_push(skb, HSR_HLEN);
365	memmove(dst, src, movelen);
366	skb_reset_mac_header(skb);
367
368	/* skb_put_padto free skb on error and hsr_fill_tag returns NULL in
369	 * that case
370	 */
371	return hsr_fill_tag(skb, frame, port, port->hsr->prot_version);
372}
373
374struct sk_buff *prp_create_tagged_frame(struct hsr_frame_info *frame,
375					struct hsr_port *port)
376{
377	struct sk_buff *skb;
378
379	if (frame->skb_prp) {
380		struct prp_rct *trailer = skb_get_PRP_rct(frame->skb_prp);
381
382		if (trailer) {
383			prp_set_lan_id(trailer, port);
384		} else {
385			WARN_ONCE(!trailer, "errored PRP skb");
386			return NULL;
387		}
388		return skb_clone(frame->skb_prp, GFP_ATOMIC);
389	} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
390		return skb_clone(frame->skb_std, GFP_ATOMIC);
391	}
392
393	skb = skb_copy_expand(frame->skb_std, skb_headroom(frame->skb_std),
394			      skb_tailroom(frame->skb_std) + HSR_HLEN,
395			      GFP_ATOMIC);
396	return prp_fill_rct(skb, frame, port);
397}
398
399static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev,
400			       struct hsr_node *node_src)
401{
402	bool was_multicast_frame;
403	int res, recv_len;
404
405	was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST);
406	hsr_addr_subst_source(node_src, skb);
407	skb_pull(skb, ETH_HLEN);
408	recv_len = skb->len;
409	res = netif_rx(skb);
410	if (res == NET_RX_DROP) {
411		dev->stats.rx_dropped++;
412	} else {
413		dev->stats.rx_packets++;
414		dev->stats.rx_bytes += recv_len;
415		if (was_multicast_frame)
416			dev->stats.multicast++;
417	}
418}
419
420static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port,
421		    struct hsr_frame_info *frame)
422{
423	if (frame->port_rcv->type == HSR_PT_MASTER) {
424		hsr_addr_subst_dest(frame->node_src, skb, port);
425
426		/* Address substitution (IEC62439-3 pp 26, 50): replace mac
427		 * address of outgoing frame with that of the outgoing slave's.
428		 */
429		ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr);
430	}
431
432	/* When HSR node is used as RedBox - the frame received from HSR ring
433	 * requires source MAC address (SA) replacement to one which can be
434	 * recognized by SAN devices (otherwise, frames are dropped by switch)
435	 */
436	if (port->type == HSR_PT_INTERLINK)
437		ether_addr_copy(eth_hdr(skb)->h_source,
438				port->hsr->macaddress_redbox);
439
440	return dev_queue_xmit(skb);
441}
442
443bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
444{
445	return ((frame->port_rcv->type == HSR_PT_SLAVE_A &&
446		 port->type == HSR_PT_SLAVE_B) ||
447		(frame->port_rcv->type == HSR_PT_SLAVE_B &&
448		 port->type == HSR_PT_SLAVE_A));
449}
450
451bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
452{
453	struct sk_buff *skb;
454
455	if (port->dev->features & NETIF_F_HW_HSR_FWD)
456		return prp_drop_frame(frame, port);
457
458	/* RedBox specific frames dropping policies
459	 *
460	 * Do not send HSR supervisory frames to SAN devices
461	 */
462	if (frame->is_supervision && port->type == HSR_PT_INTERLINK)
463		return true;
464
465	/* Do not forward to other HSR port (A or B) unicast frames which
466	 * are addressed to interlink port (and are in the ProxyNodeTable).
467	 */
468	skb = frame->skb_hsr;
469	if (skb && prp_drop_frame(frame, port) &&
470	    is_unicast_ether_addr(eth_hdr(skb)->h_dest) &&
471	    hsr_is_node_in_db(&port->hsr->proxy_node_db,
472			      eth_hdr(skb)->h_dest)) {
473		return true;
474	}
475
476	/* Do not forward to port C (Interlink) frames from nodes A and B
477	 * if DA is in NodeTable.
478	 */
479	if ((frame->port_rcv->type == HSR_PT_SLAVE_A ||
480	     frame->port_rcv->type == HSR_PT_SLAVE_B) &&
481	    port->type == HSR_PT_INTERLINK) {
482		skb = frame->skb_hsr;
483		if (skb && is_unicast_ether_addr(eth_hdr(skb)->h_dest) &&
484		    hsr_is_node_in_db(&port->hsr->node_db,
485				      eth_hdr(skb)->h_dest)) {
486			return true;
487		}
488	}
489
490	/* Do not forward to port A and B unicast frames received on the
491	 * interlink port if it is addressed to one of nodes registered in
492	 * the ProxyNodeTable.
493	 */
494	if ((port->type == HSR_PT_SLAVE_A || port->type == HSR_PT_SLAVE_B) &&
495	    frame->port_rcv->type == HSR_PT_INTERLINK) {
496		skb = frame->skb_std;
497		if (skb && is_unicast_ether_addr(eth_hdr(skb)->h_dest) &&
498		    hsr_is_node_in_db(&port->hsr->proxy_node_db,
499				      eth_hdr(skb)->h_dest)) {
500			return true;
501		}
502	}
503
504	return false;
505}
506
507/* Forward the frame through all devices except:
508 * - Back through the receiving device
509 * - If it's a HSR frame: through a device where it has passed before
510 * - if it's a PRP frame: through another PRP slave device (no bridge)
511 * - To the local HSR master only if the frame is directly addressed to it, or
512 *   a non-supervision multicast or broadcast frame.
513 *
514 * HSR slave devices should insert a HSR tag into the frame, or forward the
515 * frame unchanged if it's already tagged. Interlink devices should strip HSR
516 * tags if they're of the non-HSR type (but only after duplicate discard). The
517 * master device always strips HSR tags.
518 */
519static void hsr_forward_do(struct hsr_frame_info *frame)
520{
521	struct hsr_port *port;
522	struct sk_buff *skb;
523	bool sent = false;
524
525	hsr_for_each_port(frame->port_rcv->hsr, port) {
526		struct hsr_priv *hsr = port->hsr;
527		/* Don't send frame back the way it came */
528		if (port == frame->port_rcv)
529			continue;
530
531		/* Don't deliver locally unless we should */
532		if (port->type == HSR_PT_MASTER && !frame->is_local_dest)
533			continue;
534
535		/* Deliver frames directly addressed to us to master only */
536		if (port->type != HSR_PT_MASTER && frame->is_local_exclusive)
537			continue;
538
539		/* If hardware duplicate generation is enabled, only send out
540		 * one port.
541		 */
542		if ((port->dev->features & NETIF_F_HW_HSR_DUP) && sent)
543			continue;
544
545		/* Don't send frame over port where it has been sent before.
546		 * Also for SAN, this shouldn't be done.
547		 */
548		if (!frame->is_from_san &&
549		    hsr->proto_ops->register_frame_out &&
550		    hsr->proto_ops->register_frame_out(port, frame))
551			continue;
552
553		if (frame->is_supervision && port->type == HSR_PT_MASTER &&
554		    !frame->is_proxy_supervision) {
555			hsr_handle_sup_frame(frame);
556			continue;
557		}
558
559		/* Check if frame is to be dropped. Eg. for PRP no forward
560		 * between ports, or sending HSR supervision to RedBox.
561		 */
562		if (hsr->proto_ops->drop_frame &&
563		    hsr->proto_ops->drop_frame(frame, port))
564			continue;
565
566		if (port->type == HSR_PT_SLAVE_A ||
567		    port->type == HSR_PT_SLAVE_B)
568			skb = hsr->proto_ops->create_tagged_frame(frame, port);
569		else
570			skb = hsr->proto_ops->get_untagged_frame(frame, port);
571
572		if (!skb) {
573			frame->port_rcv->dev->stats.rx_dropped++;
574			continue;
575		}
576
577		skb->dev = port->dev;
578		if (port->type == HSR_PT_MASTER) {
579			hsr_deliver_master(skb, port->dev, frame->node_src);
580		} else {
581			if (!hsr_xmit(skb, port, frame))
582				if (port->type == HSR_PT_SLAVE_A ||
583				    port->type == HSR_PT_SLAVE_B)
584					sent = true;
585		}
586	}
587}
588
589static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb,
590			     struct hsr_frame_info *frame)
591{
592	if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) {
593		frame->is_local_exclusive = true;
594		skb->pkt_type = PACKET_HOST;
595	} else {
596		frame->is_local_exclusive = false;
597	}
598
599	if (skb->pkt_type == PACKET_HOST ||
600	    skb->pkt_type == PACKET_MULTICAST ||
601	    skb->pkt_type == PACKET_BROADCAST) {
602		frame->is_local_dest = true;
603	} else {
604		frame->is_local_dest = false;
605	}
606}
607
608static void handle_std_frame(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	frame->skb_hsr = NULL;
615	frame->skb_prp = NULL;
616	frame->skb_std = skb;
617
618	if (port->type != HSR_PT_MASTER)
619		frame->is_from_san = true;
620
621	if (port->type == HSR_PT_MASTER ||
622	    port->type == HSR_PT_INTERLINK) {
623		/* Sequence nr for the master/interlink node */
624		lockdep_assert_held(&hsr->seqnr_lock);
625		frame->sequence_nr = hsr->sequence_nr;
626		hsr->sequence_nr++;
627	}
628}
629
630int hsr_fill_frame_info(__be16 proto, struct sk_buff *skb,
631			struct hsr_frame_info *frame)
632{
633	struct hsr_port *port = frame->port_rcv;
634	struct hsr_priv *hsr = port->hsr;
635
636	/* HSRv0 supervisory frames double as a tag so treat them as tagged. */
637	if ((!hsr->prot_version && proto == htons(ETH_P_PRP)) ||
638	    proto == htons(ETH_P_HSR)) {
639		/* Check if skb contains hsr_ethhdr */
640		if (skb->mac_len < sizeof(struct hsr_ethhdr))
641			return -EINVAL;
642
643		/* HSR tagged frame :- Data or Supervision */
644		frame->skb_std = NULL;
645		frame->skb_prp = NULL;
646		frame->skb_hsr = skb;
647		frame->sequence_nr = hsr_get_skb_sequence_nr(skb);
648		return 0;
649	}
650
651	/* Standard frame or PRP from master port */
652	handle_std_frame(skb, frame);
653
654	return 0;
655}
656
657int prp_fill_frame_info(__be16 proto, struct sk_buff *skb,
658			struct hsr_frame_info *frame)
659{
660	/* Supervision frame */
661	struct prp_rct *rct = skb_get_PRP_rct(skb);
662
663	if (rct &&
664	    prp_check_lsdu_size(skb, rct, frame->is_supervision)) {
665		frame->skb_hsr = NULL;
666		frame->skb_std = NULL;
667		frame->skb_prp = skb;
668		frame->sequence_nr = prp_get_skb_sequence_nr(rct);
669		return 0;
670	}
671	handle_std_frame(skb, frame);
672
673	return 0;
674}
675
676static int fill_frame_info(struct hsr_frame_info *frame,
677			   struct sk_buff *skb, struct hsr_port *port)
678{
679	struct hsr_priv *hsr = port->hsr;
680	struct hsr_vlan_ethhdr *vlan_hdr;
681	struct list_head *n_db;
682	struct ethhdr *ethhdr;
683	__be16 proto;
684	int ret;
685
686	/* Check if skb contains ethhdr */
687	if (skb->mac_len < sizeof(struct ethhdr))
688		return -EINVAL;
689
690	memset(frame, 0, sizeof(*frame));
691	frame->is_supervision = is_supervision_frame(port->hsr, skb);
692	if (frame->is_supervision && hsr->redbox)
693		frame->is_proxy_supervision =
694			is_proxy_supervision_frame(port->hsr, skb);
695
696	n_db = &hsr->node_db;
697	if (port->type == HSR_PT_INTERLINK)
698		n_db = &hsr->proxy_node_db;
699
700	frame->node_src = hsr_get_node(port, n_db, skb,
701				       frame->is_supervision, port->type);
702	if (!frame->node_src)
703		return -1; /* Unknown node and !is_supervision, or no mem */
704
705	ethhdr = (struct ethhdr *)skb_mac_header(skb);
706	frame->is_vlan = false;
707	proto = ethhdr->h_proto;
708
709	if (proto == htons(ETH_P_8021Q))
710		frame->is_vlan = true;
711
712	if (frame->is_vlan) {
713		/* Note: skb->mac_len might be wrong here. */
714		if (!pskb_may_pull(skb,
715				   skb_mac_offset(skb) +
716				   offsetofend(struct hsr_vlan_ethhdr, vlanhdr)))
717			return -EINVAL;
718		vlan_hdr = (struct hsr_vlan_ethhdr *)skb_mac_header(skb);
719		proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto;
720	}
721
722	frame->is_from_san = false;
723	frame->port_rcv = port;
724	ret = hsr->proto_ops->fill_frame_info(proto, skb, frame);
725	if (ret)
726		return ret;
727
728	check_local_dest(port->hsr, skb, frame);
729
730	return 0;
731}
732
733/* Must be called holding rcu read lock (because of the port parameter) */
734void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
735{
736	struct hsr_frame_info frame;
737
738	rcu_read_lock();
739	if (fill_frame_info(&frame, skb, port) < 0)
740		goto out_drop;
741
742	hsr_register_frame_in(frame.node_src, port, frame.sequence_nr);
743	hsr_forward_do(&frame);
744	rcu_read_unlock();
745	/* Gets called for ingress frames as well as egress from master port.
746	 * So check and increment stats for master port only here.
747	 */
748	if (port->type == HSR_PT_MASTER || port->type == HSR_PT_INTERLINK) {
749		port->dev->stats.tx_packets++;
750		port->dev->stats.tx_bytes += skb->len;
751	}
752
753	kfree_skb(frame.skb_hsr);
754	kfree_skb(frame.skb_prp);
755	kfree_skb(frame.skb_std);
756	return;
757
758out_drop:
759	rcu_read_unlock();
760	port->dev->stats.tx_dropped++;
761	kfree_skb(skb);
762}