summaryrefslogtreecommitdiff
path: root/net/hsr/hsr_forward.c
blob: 2afe28712a7afabe1f5b4e15c3e64ea8f6fd10bd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
// SPDX-License-Identifier: GPL-2.0
/* Copyright 2011-2014 Autronica Fire and Security AS
 *
 * Author(s):
 *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
 *
 * Frame router for HSR and PRP.
 */

#include "hsr_forward.h"
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/if_vlan.h>
#include "hsr_main.h"
#include "hsr_framereg.h"

struct hsr_node;

/* The uses I can see for these HSR supervision frames are:
 * 1) Use the frames that are sent after node initialization ("HSR_TLV.Type =
 *    22") to reset any sequence_nr counters belonging to that node. Useful if
 *    the other node's counter has been reset for some reason.
 *    --
 *    Or not - resetting the counter and bridging the frame would create a
 *    loop, unfortunately.
 *
 * 2) Use the LifeCheck frames to detect ring breaks. I.e. if no LifeCheck
 *    frame is received from a particular node, we know something is wrong.
 *    We just register these (as with normal frames) and throw them away.
 *
 * 3) Allow different MAC addresses for the two slave interfaces, using the
 *    MacAddressA field.
 */
static bool is_supervision_frame(struct hsr_priv *hsr, struct sk_buff *skb)
{
	struct ethhdr *eth_hdr;
	struct hsr_sup_tag *hsr_sup_tag;
	struct hsrv1_ethhdr_sp *hsr_V1_hdr;
	struct hsr_sup_tlv *hsr_sup_tlv;
	u16 total_length = 0;

	WARN_ON_ONCE(!skb_mac_header_was_set(skb));
	eth_hdr = (struct ethhdr *)skb_mac_header(skb);

	/* Correct addr? */
	if (!ether_addr_equal(eth_hdr->h_dest,
			      hsr->sup_multicast_addr))
		return false;

	/* Correct ether type?. */
	if (!(eth_hdr->h_proto == htons(ETH_P_PRP) ||
	      eth_hdr->h_proto == htons(ETH_P_HSR)))
		return false;

	/* Get the supervision header from correct location. */
	if (eth_hdr->h_proto == htons(ETH_P_HSR)) { /* Okay HSRv1. */
		total_length = sizeof(struct hsrv1_ethhdr_sp);
		if (!pskb_may_pull(skb, total_length))
			return false;

		hsr_V1_hdr = (struct hsrv1_ethhdr_sp *)skb_mac_header(skb);
		if (hsr_V1_hdr->hsr.encap_proto != htons(ETH_P_PRP))
			return false;

		hsr_sup_tag = &hsr_V1_hdr->hsr_sup;
	} else {
		total_length = sizeof(struct hsrv0_ethhdr_sp);
		if (!pskb_may_pull(skb, total_length))
			return false;

		hsr_sup_tag =
		     &((struct hsrv0_ethhdr_sp *)skb_mac_header(skb))->hsr_sup;
	}

	if (hsr_sup_tag->tlv.HSR_TLV_type != HSR_TLV_ANNOUNCE &&
	    hsr_sup_tag->tlv.HSR_TLV_type != HSR_TLV_LIFE_CHECK &&
	    hsr_sup_tag->tlv.HSR_TLV_type != PRP_TLV_LIFE_CHECK_DD &&
	    hsr_sup_tag->tlv.HSR_TLV_type != PRP_TLV_LIFE_CHECK_DA)
		return false;
	if (hsr_sup_tag->tlv.HSR_TLV_length != 12 &&
	    hsr_sup_tag->tlv.HSR_TLV_length != sizeof(struct hsr_sup_payload))
		return false;

	/* Get next tlv */
	total_length += sizeof(struct hsr_sup_tlv) + hsr_sup_tag->tlv.HSR_TLV_length;
	if (!pskb_may_pull(skb, total_length))
		return false;
	skb_pull(skb, total_length);
	hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
	skb_push(skb, total_length);

	/* if this is a redbox supervision frame we need to verify
	 * that more data is available
	 */
	if (hsr_sup_tlv->HSR_TLV_type == PRP_TLV_REDBOX_MAC) {
		/* tlv length must be a length of a mac address */
		if (hsr_sup_tlv->HSR_TLV_length != sizeof(struct hsr_sup_payload))
			return false;

		/* make sure another tlv follows */
		total_length += sizeof(struct hsr_sup_tlv) + hsr_sup_tlv->HSR_TLV_length;
		if (!pskb_may_pull(skb, total_length))
			return false;

		/* get next tlv */
		skb_pull(skb, total_length);
		hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
		skb_push(skb, total_length);
	}

	/* end of tlvs must follow at the end */
	if (hsr_sup_tlv->HSR_TLV_type == HSR_TLV_EOT &&
	    hsr_sup_tlv->HSR_TLV_length != 0)
		return false;

	return true;
}

static struct sk_buff *create_stripped_skb_hsr(struct sk_buff *skb_in,
					       struct hsr_frame_info *frame)
{
	struct sk_buff *skb;
	int copylen;
	unsigned char *dst, *src;

	skb_pull(skb_in, HSR_HLEN);
	skb = __pskb_copy(skb_in, skb_headroom(skb_in) - HSR_HLEN, GFP_ATOMIC);
	skb_push(skb_in, HSR_HLEN);
	if (!skb)
		return NULL;

	skb_reset_mac_header(skb);

	if (skb->ip_summed == CHECKSUM_PARTIAL)
		skb->csum_start -= HSR_HLEN;

	copylen = 2 * ETH_ALEN;
	if (frame->is_vlan)
		copylen += VLAN_HLEN;
	src = skb_mac_header(skb_in);
	dst = skb_mac_header(skb);
	memcpy(dst, src, copylen);

	skb->protocol = eth_hdr(skb)->h_proto;
	return skb;
}

struct sk_buff *hsr_get_untagged_frame(struct hsr_frame_info *frame,
				       struct hsr_port *port)
{
	if (!frame->skb_std) {
		if (frame->skb_hsr)
			frame->skb_std =
				create_stripped_skb_hsr(frame->skb_hsr, frame);
		else
			netdev_warn_once(port->dev,
					 "Unexpected frame received in hsr_get_untagged_frame()\n");

		if (!frame->skb_std)
			return NULL;
	}

	return skb_clone(frame->skb_std, GFP_ATOMIC);
}

struct sk_buff *prp_get_untagged_frame(struct hsr_frame_info *frame,
				       struct hsr_port *port)
{
	if (!frame->skb_std) {
		if (frame->skb_prp) {
			/* trim the skb by len - HSR_HLEN to exclude RCT */
			skb_trim(frame->skb_prp,
				 frame->skb_prp->len - HSR_HLEN);
			frame->skb_std =
				__pskb_copy(frame->skb_prp,
					    skb_headroom(frame->skb_prp),
					    GFP_ATOMIC);
		} else {
			/* Unexpected */
			WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n",
				  __FILE__, __LINE__, port->dev->name);
			return NULL;
		}
	}

	return skb_clone(frame->skb_std, GFP_ATOMIC);
}

static void prp_set_lan_id(struct prp_rct *trailer,
			   struct hsr_port *port)
{
	int lane_id;

	if (port->type == HSR_PT_SLAVE_A)
		lane_id = 0;
	else
		lane_id = 1;

	/* Add net_id in the upper 3 bits of lane_id */
	lane_id |= port->hsr->net_id;
	set_prp_lan_id(trailer, lane_id);
}

/* Tailroom for PRP rct should have been created before calling this */
static struct sk_buff *prp_fill_rct(struct sk_buff *skb,
				    struct hsr_frame_info *frame,
				    struct hsr_port *port)
{
	struct prp_rct *trailer;
	int min_size = ETH_ZLEN;
	int lsdu_size;

	if (!skb)
		return skb;

	if (frame->is_vlan)
		min_size = VLAN_ETH_ZLEN;

	if (skb_put_padto(skb, min_size))
		return NULL;

	trailer = (struct prp_rct *)skb_put(skb, HSR_HLEN);
	lsdu_size = skb->len - 14;
	if (frame->is_vlan)
		lsdu_size -= 4;
	prp_set_lan_id(trailer, port);
	set_prp_LSDU_size(trailer, lsdu_size);
	trailer->sequence_nr = htons(frame->sequence_nr);
	trailer->PRP_suffix = htons(ETH_P_PRP);
	skb->protocol = eth_hdr(skb)->h_proto;

	return skb;
}

static void hsr_set_path_id(struct hsr_ethhdr *hsr_ethhdr,
			    struct hsr_port *port)
{
	int path_id;

	if (port->type == HSR_PT_SLAVE_A)
		path_id = 0;
	else
		path_id = 1;

	set_hsr_tag_path(&hsr_ethhdr->hsr_tag, path_id);
}

static struct sk_buff *hsr_fill_tag(struct sk_buff *skb,
				    struct hsr_frame_info *frame,
				    struct hsr_port *port, u8 proto_version)
{
	struct hsr_ethhdr *hsr_ethhdr;
	int lsdu_size;

	/* pad to minimum packet size which is 60 + 6 (HSR tag) */
	if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
		return NULL;

	lsdu_size = skb->len - 14;
	if (frame->is_vlan)
		lsdu_size -= 4;

	hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(skb);

	hsr_set_path_id(hsr_ethhdr, port);
	set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size);
	hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr);
	hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
	hsr_ethhdr->ethhdr.h_proto = htons(proto_version ?
			ETH_P_HSR : ETH_P_PRP);
	skb->protocol = hsr_ethhdr->ethhdr.h_proto;

	return skb;
}

/* If the original frame was an HSR tagged frame, just clone it to be sent
 * unchanged. Otherwise, create a private frame especially tagged for 'port'.
 */
struct sk_buff *hsr_create_tagged_frame(struct hsr_frame_info *frame,
					struct hsr_port *port)
{
	unsigned char *dst, *src;
	struct sk_buff *skb;
	int movelen;

	if (frame->skb_hsr) {
		struct hsr_ethhdr *hsr_ethhdr =
			(struct hsr_ethhdr *)skb_mac_header(frame->skb_hsr);

		/* set the lane id properly */
		hsr_set_path_id(hsr_ethhdr, port);
		return skb_clone(frame->skb_hsr, GFP_ATOMIC);
	} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
		return skb_clone(frame->skb_std, GFP_ATOMIC);
	}

	/* Create the new skb with enough headroom to fit the HSR tag */
	skb = __pskb_copy(frame->skb_std,
			  skb_headroom(frame->skb_std) + HSR_HLEN, GFP_ATOMIC);
	if (!skb)
		return NULL;
	skb_reset_mac_header(skb);

	if (skb->ip_summed == CHECKSUM_PARTIAL)
		skb->csum_start += HSR_HLEN;

	movelen = ETH_HLEN;
	if (frame->is_vlan)
		movelen += VLAN_HLEN;

	src = skb_mac_header(skb);
	dst = skb_push(skb, HSR_HLEN);
	memmove(dst, src, movelen);
	skb_reset_mac_header(skb);

	/* skb_put_padto free skb on error and hsr_fill_tag returns NULL in
	 * that case
	 */
	return hsr_fill_tag(skb, frame, port, port->hsr->prot_version);
}

struct sk_buff *prp_create_tagged_frame(struct hsr_frame_info *frame,
					struct hsr_port *port)
{
	struct sk_buff *skb;

	if (frame->skb_prp) {
		struct prp_rct *trailer = skb_get_PRP_rct(frame->skb_prp);

		if (trailer) {
			prp_set_lan_id(trailer, port);
		} else {
			WARN_ONCE(!trailer, "errored PRP skb");
			return NULL;
		}
		return skb_clone(frame->skb_prp, GFP_ATOMIC);
	} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
		return skb_clone(frame->skb_std, GFP_ATOMIC);
	}

	skb = skb_copy_expand(frame->skb_std, 0,
			      skb_tailroom(frame->skb_std) + HSR_HLEN,
			      GFP_ATOMIC);
	return prp_fill_rct(skb, frame, port);
}

static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev,
			       struct hsr_node *node_src)
{
	bool was_multicast_frame;
	int res, recv_len;

	was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST);
	hsr_addr_subst_source(node_src, skb);
	skb_pull(skb, ETH_HLEN);
	recv_len = skb->len;
	res = netif_rx(skb);
	if (res == NET_RX_DROP) {
		dev->stats.rx_dropped++;
	} else {
		dev->stats.rx_packets++;
		dev->stats.rx_bytes += recv_len;
		if (was_multicast_frame)
			dev->stats.multicast++;
	}
}

static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port,
		    struct hsr_frame_info *frame)
{
	if (frame->port_rcv->type == HSR_PT_MASTER) {
		hsr_addr_subst_dest(frame->node_src, skb, port);

		/* Address substitution (IEC62439-3 pp 26, 50): replace mac
		 * address of outgoing frame with that of the outgoing slave's.
		 */
		ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr);
	}
	return dev_queue_xmit(skb);
}

bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
{
	return ((frame->port_rcv->type == HSR_PT_SLAVE_A &&
		 port->type ==  HSR_PT_SLAVE_B) ||
		(frame->port_rcv->type == HSR_PT_SLAVE_B &&
		 port->type ==  HSR_PT_SLAVE_A));
}

bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
{
	if (port->dev->features & NETIF_F_HW_HSR_FWD)
		return prp_drop_frame(frame, port);

	return false;
}

/* Forward the frame through all devices except:
 * - Back through the receiving device
 * - If it's a HSR frame: through a device where it has passed before
 * - if it's a PRP frame: through another PRP slave device (no bridge)
 * - To the local HSR master only if the frame is directly addressed to it, or
 *   a non-supervision multicast or broadcast frame.
 *
 * HSR slave devices should insert a HSR tag into the frame, or forward the
 * frame unchanged if it's already tagged. Interlink devices should strip HSR
 * tags if they're of the non-HSR type (but only after duplicate discard). The
 * master device always strips HSR tags.
 */
static void hsr_forward_do(struct hsr_frame_info *frame)
{
	struct hsr_port *port;
	struct sk_buff *skb;
	bool sent = false;

	hsr_for_each_port(frame->port_rcv->hsr, port) {
		struct hsr_priv *hsr = port->hsr;
		/* Don't send frame back the way it came */
		if (port == frame->port_rcv)
			continue;

		/* Don't deliver locally unless we should */
		if (port->type == HSR_PT_MASTER && !frame->is_local_dest)
			continue;

		/* Deliver frames directly addressed to us to master only */
		if (port->type != HSR_PT_MASTER && frame->is_local_exclusive)
			continue;

		/* If hardware duplicate generation is enabled, only send out
		 * one port.
		 */
		if ((port->dev->features & NETIF_F_HW_HSR_DUP) && sent)
			continue;

		/* Don't send frame over port where it has been sent before.
		 * Also for SAN, this shouldn't be done.
		 */
		if (!frame->is_from_san &&
		    hsr_register_frame_out(port, frame->node_src,
					   frame->sequence_nr))
			continue;

		if (frame->is_supervision && port->type == HSR_PT_MASTER) {
			hsr_handle_sup_frame(frame);
			continue;
		}

		/* Check if frame is to be dropped. Eg. for PRP no forward
		 * between ports.
		 */
		if (hsr->proto_ops->drop_frame &&
		    hsr->proto_ops->drop_frame(frame, port))
			continue;

		if (port->type != HSR_PT_MASTER)
			skb = hsr->proto_ops->create_tagged_frame(frame, port);
		else
			skb = hsr->proto_ops->get_untagged_frame(frame, port);

		if (!skb) {
			frame->port_rcv->dev->stats.rx_dropped++;
			continue;
		}

		skb->dev = port->dev;
		if (port->type == HSR_PT_MASTER) {
			hsr_deliver_master(skb, port->dev, frame->node_src);
		} else {
			if (!hsr_xmit(skb, port, frame))
				sent = true;
		}
	}
}

static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb,
			     struct hsr_frame_info *frame)
{
	if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) {
		frame->is_local_exclusive = true;
		skb->pkt_type = PACKET_HOST;
	} else {
		frame->is_local_exclusive = false;
	}

	if (skb->pkt_type == PACKET_HOST ||
	    skb->pkt_type == PACKET_MULTICAST ||
	    skb->pkt_type == PACKET_BROADCAST) {
		frame->is_local_dest = true;
	} else {
		frame->is_local_dest = false;
	}
}

static void handle_std_frame(struct sk_buff *skb,
			     struct hsr_frame_info *frame)
{
	struct hsr_port *port = frame->port_rcv;
	struct hsr_priv *hsr = port->hsr;

	frame->skb_hsr = NULL;
	frame->skb_prp = NULL;
	frame->skb_std = skb;

	if (port->type != HSR_PT_MASTER) {
		frame->is_from_san = true;
	} else {
		/* Sequence nr for the master node */
		lockdep_assert_held(&hsr->seqnr_lock);
		frame->sequence_nr = hsr->sequence_nr;
		hsr->sequence_nr++;
	}
}

int hsr_fill_frame_info(__be16 proto, struct sk_buff *skb,
			struct hsr_frame_info *frame)
{
	struct hsr_port *port = frame->port_rcv;
	struct hsr_priv *hsr = port->hsr;

	/* HSRv0 supervisory frames double as a tag so treat them as tagged. */
	if ((!hsr->prot_version && proto == htons(ETH_P_PRP)) ||
	    proto == htons(ETH_P_HSR)) {
		/* Check if skb contains hsr_ethhdr */
		if (skb->mac_len < sizeof(struct hsr_ethhdr))
			return -EINVAL;

		/* HSR tagged frame :- Data or Supervision */
		frame->skb_std = NULL;
		frame->skb_prp = NULL;
		frame->skb_hsr = skb;
		frame->sequence_nr = hsr_get_skb_sequence_nr(skb);
		return 0;
	}

	/* Standard frame or PRP from master port */
	handle_std_frame(skb, frame);

	return 0;
}

int prp_fill_frame_info(__be16 proto, struct sk_buff *skb,
			struct hsr_frame_info *frame)
{
	/* Supervision frame */
	struct prp_rct *rct = skb_get_PRP_rct(skb);

	if (rct &&
	    prp_check_lsdu_size(skb, rct, frame->is_supervision)) {
		frame->skb_hsr = NULL;
		frame->skb_std = NULL;
		frame->skb_prp = skb;
		frame->sequence_nr = prp_get_skb_sequence_nr(rct);
		return 0;
	}
	handle_std_frame(skb, frame);

	return 0;
}

static int fill_frame_info(struct hsr_frame_info *frame,
			   struct sk_buff *skb, struct hsr_port *port)
{
	struct hsr_priv *hsr = port->hsr;
	struct hsr_vlan_ethhdr *vlan_hdr;
	struct ethhdr *ethhdr;
	__be16 proto;
	int ret;

	/* Check if skb contains ethhdr */
	if (skb->mac_len < sizeof(struct ethhdr))
		return -EINVAL;

	memset(frame, 0, sizeof(*frame));
	frame->is_supervision = is_supervision_frame(port->hsr, skb);
	frame->node_src = hsr_get_node(port, &hsr->node_db, skb,
				       frame->is_supervision,
				       port->type);
	if (!frame->node_src)
		return -1; /* Unknown node and !is_supervision, or no mem */

	ethhdr = (struct ethhdr *)skb_mac_header(skb);
	frame->is_vlan = false;
	proto = ethhdr->h_proto;

	if (proto == htons(ETH_P_8021Q))
		frame->is_vlan = true;

	if (frame->is_vlan) {
		vlan_hdr = (struct hsr_vlan_ethhdr *)ethhdr;
		proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto;
		/* FIXME: */
		netdev_warn_once(skb->dev, "VLAN not yet supported");
		return -EINVAL;
	}

	frame->is_from_san = false;
	frame->port_rcv = port;
	ret = hsr->proto_ops->fill_frame_info(proto, skb, frame);
	if (ret)
		return ret;

	check_local_dest(port->hsr, skb, frame);

	return 0;
}

/* Must be called holding rcu read lock (because of the port parameter) */
void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
{
	struct hsr_frame_info frame;

	rcu_read_lock();
	if (fill_frame_info(&frame, skb, port) < 0)
		goto out_drop;

	hsr_register_frame_in(frame.node_src, port, frame.sequence_nr);
	hsr_forward_do(&frame);
	rcu_read_unlock();
	/* Gets called for ingress frames as well as egress from master port.
	 * So check and increment stats for master port only here.
	 */
	if (port->type == HSR_PT_MASTER) {
		port->dev->stats.tx_packets++;
		port->dev->stats.tx_bytes += skb->len;
	}

	kfree_skb(frame.skb_hsr);
	kfree_skb(frame.skb_prp);
	kfree_skb(frame.skb_std);
	return;

out_drop:
	rcu_read_unlock();
	port->dev->stats.tx_dropped++;
	kfree_skb(skb);
}