xref: /openbmc/linux/net/hsr/hsr_forward.c (revision 6db6b729)
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 += sizeof(struct hsr_sup_tlv) + 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 struct sk_buff *create_stripped_skb_hsr(struct sk_buff *skb_in,
121 					       struct hsr_frame_info *frame)
122 {
123 	struct sk_buff *skb;
124 	int copylen;
125 	unsigned char *dst, *src;
126 
127 	skb_pull(skb_in, HSR_HLEN);
128 	skb = __pskb_copy(skb_in, skb_headroom(skb_in) - HSR_HLEN, GFP_ATOMIC);
129 	skb_push(skb_in, HSR_HLEN);
130 	if (!skb)
131 		return NULL;
132 
133 	skb_reset_mac_header(skb);
134 
135 	if (skb->ip_summed == CHECKSUM_PARTIAL)
136 		skb->csum_start -= HSR_HLEN;
137 
138 	copylen = 2 * ETH_ALEN;
139 	if (frame->is_vlan)
140 		copylen += VLAN_HLEN;
141 	src = skb_mac_header(skb_in);
142 	dst = skb_mac_header(skb);
143 	memcpy(dst, src, copylen);
144 
145 	skb->protocol = eth_hdr(skb)->h_proto;
146 	return skb;
147 }
148 
149 struct sk_buff *hsr_get_untagged_frame(struct hsr_frame_info *frame,
150 				       struct hsr_port *port)
151 {
152 	if (!frame->skb_std) {
153 		if (frame->skb_hsr)
154 			frame->skb_std =
155 				create_stripped_skb_hsr(frame->skb_hsr, frame);
156 		else
157 			netdev_warn_once(port->dev,
158 					 "Unexpected frame received in hsr_get_untagged_frame()\n");
159 
160 		if (!frame->skb_std)
161 			return NULL;
162 	}
163 
164 	return skb_clone(frame->skb_std, GFP_ATOMIC);
165 }
166 
167 struct sk_buff *prp_get_untagged_frame(struct hsr_frame_info *frame,
168 				       struct hsr_port *port)
169 {
170 	if (!frame->skb_std) {
171 		if (frame->skb_prp) {
172 			/* trim the skb by len - HSR_HLEN to exclude RCT */
173 			skb_trim(frame->skb_prp,
174 				 frame->skb_prp->len - HSR_HLEN);
175 			frame->skb_std =
176 				__pskb_copy(frame->skb_prp,
177 					    skb_headroom(frame->skb_prp),
178 					    GFP_ATOMIC);
179 		} else {
180 			/* Unexpected */
181 			WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n",
182 				  __FILE__, __LINE__, port->dev->name);
183 			return NULL;
184 		}
185 	}
186 
187 	return skb_clone(frame->skb_std, GFP_ATOMIC);
188 }
189 
190 static void prp_set_lan_id(struct prp_rct *trailer,
191 			   struct hsr_port *port)
192 {
193 	int lane_id;
194 
195 	if (port->type == HSR_PT_SLAVE_A)
196 		lane_id = 0;
197 	else
198 		lane_id = 1;
199 
200 	/* Add net_id in the upper 3 bits of lane_id */
201 	lane_id |= port->hsr->net_id;
202 	set_prp_lan_id(trailer, lane_id);
203 }
204 
205 /* Tailroom for PRP rct should have been created before calling this */
206 static struct sk_buff *prp_fill_rct(struct sk_buff *skb,
207 				    struct hsr_frame_info *frame,
208 				    struct hsr_port *port)
209 {
210 	struct prp_rct *trailer;
211 	int min_size = ETH_ZLEN;
212 	int lsdu_size;
213 
214 	if (!skb)
215 		return skb;
216 
217 	if (frame->is_vlan)
218 		min_size = VLAN_ETH_ZLEN;
219 
220 	if (skb_put_padto(skb, min_size))
221 		return NULL;
222 
223 	trailer = (struct prp_rct *)skb_put(skb, HSR_HLEN);
224 	lsdu_size = skb->len - 14;
225 	if (frame->is_vlan)
226 		lsdu_size -= 4;
227 	prp_set_lan_id(trailer, port);
228 	set_prp_LSDU_size(trailer, lsdu_size);
229 	trailer->sequence_nr = htons(frame->sequence_nr);
230 	trailer->PRP_suffix = htons(ETH_P_PRP);
231 	skb->protocol = eth_hdr(skb)->h_proto;
232 
233 	return skb;
234 }
235 
236 static void hsr_set_path_id(struct hsr_ethhdr *hsr_ethhdr,
237 			    struct hsr_port *port)
238 {
239 	int path_id;
240 
241 	if (port->type == HSR_PT_SLAVE_A)
242 		path_id = 0;
243 	else
244 		path_id = 1;
245 
246 	set_hsr_tag_path(&hsr_ethhdr->hsr_tag, path_id);
247 }
248 
249 static struct sk_buff *hsr_fill_tag(struct sk_buff *skb,
250 				    struct hsr_frame_info *frame,
251 				    struct hsr_port *port, u8 proto_version)
252 {
253 	struct hsr_ethhdr *hsr_ethhdr;
254 	int lsdu_size;
255 
256 	/* pad to minimum packet size which is 60 + 6 (HSR tag) */
257 	if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
258 		return NULL;
259 
260 	lsdu_size = skb->len - 14;
261 	if (frame->is_vlan)
262 		lsdu_size -= 4;
263 
264 	hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(skb);
265 
266 	hsr_set_path_id(hsr_ethhdr, port);
267 	set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size);
268 	hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr);
269 	hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
270 	hsr_ethhdr->ethhdr.h_proto = htons(proto_version ?
271 			ETH_P_HSR : ETH_P_PRP);
272 	skb->protocol = hsr_ethhdr->ethhdr.h_proto;
273 
274 	return skb;
275 }
276 
277 /* If the original frame was an HSR tagged frame, just clone it to be sent
278  * unchanged. Otherwise, create a private frame especially tagged for 'port'.
279  */
280 struct sk_buff *hsr_create_tagged_frame(struct hsr_frame_info *frame,
281 					struct hsr_port *port)
282 {
283 	unsigned char *dst, *src;
284 	struct sk_buff *skb;
285 	int movelen;
286 
287 	if (frame->skb_hsr) {
288 		struct hsr_ethhdr *hsr_ethhdr =
289 			(struct hsr_ethhdr *)skb_mac_header(frame->skb_hsr);
290 
291 		/* set the lane id properly */
292 		hsr_set_path_id(hsr_ethhdr, port);
293 		return skb_clone(frame->skb_hsr, GFP_ATOMIC);
294 	} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
295 		return skb_clone(frame->skb_std, GFP_ATOMIC);
296 	}
297 
298 	/* Create the new skb with enough headroom to fit the HSR tag */
299 	skb = __pskb_copy(frame->skb_std,
300 			  skb_headroom(frame->skb_std) + HSR_HLEN, GFP_ATOMIC);
301 	if (!skb)
302 		return NULL;
303 	skb_reset_mac_header(skb);
304 
305 	if (skb->ip_summed == CHECKSUM_PARTIAL)
306 		skb->csum_start += HSR_HLEN;
307 
308 	movelen = ETH_HLEN;
309 	if (frame->is_vlan)
310 		movelen += VLAN_HLEN;
311 
312 	src = skb_mac_header(skb);
313 	dst = skb_push(skb, HSR_HLEN);
314 	memmove(dst, src, movelen);
315 	skb_reset_mac_header(skb);
316 
317 	/* skb_put_padto free skb on error and hsr_fill_tag returns NULL in
318 	 * that case
319 	 */
320 	return hsr_fill_tag(skb, frame, port, port->hsr->prot_version);
321 }
322 
323 struct sk_buff *prp_create_tagged_frame(struct hsr_frame_info *frame,
324 					struct hsr_port *port)
325 {
326 	struct sk_buff *skb;
327 
328 	if (frame->skb_prp) {
329 		struct prp_rct *trailer = skb_get_PRP_rct(frame->skb_prp);
330 
331 		if (trailer) {
332 			prp_set_lan_id(trailer, port);
333 		} else {
334 			WARN_ONCE(!trailer, "errored PRP skb");
335 			return NULL;
336 		}
337 		return skb_clone(frame->skb_prp, GFP_ATOMIC);
338 	} else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
339 		return skb_clone(frame->skb_std, GFP_ATOMIC);
340 	}
341 
342 	skb = skb_copy_expand(frame->skb_std, 0,
343 			      skb_tailroom(frame->skb_std) + HSR_HLEN,
344 			      GFP_ATOMIC);
345 	prp_fill_rct(skb, frame, port);
346 
347 	return skb;
348 }
349 
350 static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev,
351 			       struct hsr_node *node_src)
352 {
353 	bool was_multicast_frame;
354 	int res, recv_len;
355 
356 	was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST);
357 	hsr_addr_subst_source(node_src, skb);
358 	skb_pull(skb, ETH_HLEN);
359 	recv_len = skb->len;
360 	res = netif_rx(skb);
361 	if (res == NET_RX_DROP) {
362 		dev->stats.rx_dropped++;
363 	} else {
364 		dev->stats.rx_packets++;
365 		dev->stats.rx_bytes += recv_len;
366 		if (was_multicast_frame)
367 			dev->stats.multicast++;
368 	}
369 }
370 
371 static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port,
372 		    struct hsr_frame_info *frame)
373 {
374 	if (frame->port_rcv->type == HSR_PT_MASTER) {
375 		hsr_addr_subst_dest(frame->node_src, skb, port);
376 
377 		/* Address substitution (IEC62439-3 pp 26, 50): replace mac
378 		 * address of outgoing frame with that of the outgoing slave's.
379 		 */
380 		ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr);
381 	}
382 	return dev_queue_xmit(skb);
383 }
384 
385 bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
386 {
387 	return ((frame->port_rcv->type == HSR_PT_SLAVE_A &&
388 		 port->type ==  HSR_PT_SLAVE_B) ||
389 		(frame->port_rcv->type == HSR_PT_SLAVE_B &&
390 		 port->type ==  HSR_PT_SLAVE_A));
391 }
392 
393 bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
394 {
395 	if (port->dev->features & NETIF_F_HW_HSR_FWD)
396 		return prp_drop_frame(frame, port);
397 
398 	return false;
399 }
400 
401 /* Forward the frame through all devices except:
402  * - Back through the receiving device
403  * - If it's a HSR frame: through a device where it has passed before
404  * - if it's a PRP frame: through another PRP slave device (no bridge)
405  * - To the local HSR master only if the frame is directly addressed to it, or
406  *   a non-supervision multicast or broadcast frame.
407  *
408  * HSR slave devices should insert a HSR tag into the frame, or forward the
409  * frame unchanged if it's already tagged. Interlink devices should strip HSR
410  * tags if they're of the non-HSR type (but only after duplicate discard). The
411  * master device always strips HSR tags.
412  */
413 static void hsr_forward_do(struct hsr_frame_info *frame)
414 {
415 	struct hsr_port *port;
416 	struct sk_buff *skb;
417 	bool sent = false;
418 
419 	hsr_for_each_port(frame->port_rcv->hsr, port) {
420 		struct hsr_priv *hsr = port->hsr;
421 		/* Don't send frame back the way it came */
422 		if (port == frame->port_rcv)
423 			continue;
424 
425 		/* Don't deliver locally unless we should */
426 		if (port->type == HSR_PT_MASTER && !frame->is_local_dest)
427 			continue;
428 
429 		/* Deliver frames directly addressed to us to master only */
430 		if (port->type != HSR_PT_MASTER && frame->is_local_exclusive)
431 			continue;
432 
433 		/* If hardware duplicate generation is enabled, only send out
434 		 * one port.
435 		 */
436 		if ((port->dev->features & NETIF_F_HW_HSR_DUP) && sent)
437 			continue;
438 
439 		/* Don't send frame over port where it has been sent before.
440 		 * Also fro SAN, this shouldn't be done.
441 		 */
442 		if (!frame->is_from_san &&
443 		    hsr_register_frame_out(port, frame->node_src,
444 					   frame->sequence_nr))
445 			continue;
446 
447 		if (frame->is_supervision && port->type == HSR_PT_MASTER) {
448 			hsr_handle_sup_frame(frame);
449 			continue;
450 		}
451 
452 		/* Check if frame is to be dropped. Eg. for PRP no forward
453 		 * between ports.
454 		 */
455 		if (hsr->proto_ops->drop_frame &&
456 		    hsr->proto_ops->drop_frame(frame, port))
457 			continue;
458 
459 		if (port->type != HSR_PT_MASTER)
460 			skb = hsr->proto_ops->create_tagged_frame(frame, port);
461 		else
462 			skb = hsr->proto_ops->get_untagged_frame(frame, port);
463 
464 		if (!skb) {
465 			frame->port_rcv->dev->stats.rx_dropped++;
466 			continue;
467 		}
468 
469 		skb->dev = port->dev;
470 		if (port->type == HSR_PT_MASTER) {
471 			hsr_deliver_master(skb, port->dev, frame->node_src);
472 		} else {
473 			if (!hsr_xmit(skb, port, frame))
474 				sent = true;
475 		}
476 	}
477 }
478 
479 static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb,
480 			     struct hsr_frame_info *frame)
481 {
482 	if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) {
483 		frame->is_local_exclusive = true;
484 		skb->pkt_type = PACKET_HOST;
485 	} else {
486 		frame->is_local_exclusive = false;
487 	}
488 
489 	if (skb->pkt_type == PACKET_HOST ||
490 	    skb->pkt_type == PACKET_MULTICAST ||
491 	    skb->pkt_type == PACKET_BROADCAST) {
492 		frame->is_local_dest = true;
493 	} else {
494 		frame->is_local_dest = false;
495 	}
496 }
497 
498 static void handle_std_frame(struct sk_buff *skb,
499 			     struct hsr_frame_info *frame)
500 {
501 	struct hsr_port *port = frame->port_rcv;
502 	struct hsr_priv *hsr = port->hsr;
503 
504 	frame->skb_hsr = NULL;
505 	frame->skb_prp = NULL;
506 	frame->skb_std = skb;
507 
508 	if (port->type != HSR_PT_MASTER) {
509 		frame->is_from_san = true;
510 	} else {
511 		/* Sequence nr for the master node */
512 		lockdep_assert_held(&hsr->seqnr_lock);
513 		frame->sequence_nr = hsr->sequence_nr;
514 		hsr->sequence_nr++;
515 	}
516 }
517 
518 int hsr_fill_frame_info(__be16 proto, struct sk_buff *skb,
519 			struct hsr_frame_info *frame)
520 {
521 	struct hsr_port *port = frame->port_rcv;
522 	struct hsr_priv *hsr = port->hsr;
523 
524 	/* HSRv0 supervisory frames double as a tag so treat them as tagged. */
525 	if ((!hsr->prot_version && proto == htons(ETH_P_PRP)) ||
526 	    proto == htons(ETH_P_HSR)) {
527 		/* Check if skb contains hsr_ethhdr */
528 		if (skb->mac_len < sizeof(struct hsr_ethhdr))
529 			return -EINVAL;
530 
531 		/* HSR tagged frame :- Data or Supervision */
532 		frame->skb_std = NULL;
533 		frame->skb_prp = NULL;
534 		frame->skb_hsr = skb;
535 		frame->sequence_nr = hsr_get_skb_sequence_nr(skb);
536 		return 0;
537 	}
538 
539 	/* Standard frame or PRP from master port */
540 	handle_std_frame(skb, frame);
541 
542 	return 0;
543 }
544 
545 int prp_fill_frame_info(__be16 proto, struct sk_buff *skb,
546 			struct hsr_frame_info *frame)
547 {
548 	/* Supervision frame */
549 	struct prp_rct *rct = skb_get_PRP_rct(skb);
550 
551 	if (rct &&
552 	    prp_check_lsdu_size(skb, rct, frame->is_supervision)) {
553 		frame->skb_hsr = NULL;
554 		frame->skb_std = NULL;
555 		frame->skb_prp = skb;
556 		frame->sequence_nr = prp_get_skb_sequence_nr(rct);
557 		return 0;
558 	}
559 	handle_std_frame(skb, frame);
560 
561 	return 0;
562 }
563 
564 static int fill_frame_info(struct hsr_frame_info *frame,
565 			   struct sk_buff *skb, struct hsr_port *port)
566 {
567 	struct hsr_priv *hsr = port->hsr;
568 	struct hsr_vlan_ethhdr *vlan_hdr;
569 	struct ethhdr *ethhdr;
570 	__be16 proto;
571 	int ret;
572 
573 	/* Check if skb contains ethhdr */
574 	if (skb->mac_len < sizeof(struct ethhdr))
575 		return -EINVAL;
576 
577 	memset(frame, 0, sizeof(*frame));
578 	frame->is_supervision = is_supervision_frame(port->hsr, skb);
579 	frame->node_src = hsr_get_node(port, &hsr->node_db, skb,
580 				       frame->is_supervision,
581 				       port->type);
582 	if (!frame->node_src)
583 		return -1; /* Unknown node and !is_supervision, or no mem */
584 
585 	ethhdr = (struct ethhdr *)skb_mac_header(skb);
586 	frame->is_vlan = false;
587 	proto = ethhdr->h_proto;
588 
589 	if (proto == htons(ETH_P_8021Q))
590 		frame->is_vlan = true;
591 
592 	if (frame->is_vlan) {
593 		vlan_hdr = (struct hsr_vlan_ethhdr *)ethhdr;
594 		proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto;
595 		/* FIXME: */
596 		netdev_warn_once(skb->dev, "VLAN not yet supported");
597 		return -EINVAL;
598 	}
599 
600 	frame->is_from_san = false;
601 	frame->port_rcv = port;
602 	ret = hsr->proto_ops->fill_frame_info(proto, skb, frame);
603 	if (ret)
604 		return ret;
605 
606 	check_local_dest(port->hsr, skb, frame);
607 
608 	return 0;
609 }
610 
611 /* Must be called holding rcu read lock (because of the port parameter) */
612 void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
613 {
614 	struct hsr_frame_info frame;
615 
616 	rcu_read_lock();
617 	if (fill_frame_info(&frame, skb, port) < 0)
618 		goto out_drop;
619 
620 	hsr_register_frame_in(frame.node_src, port, frame.sequence_nr);
621 	hsr_forward_do(&frame);
622 	rcu_read_unlock();
623 	/* Gets called for ingress frames as well as egress from master port.
624 	 * So check and increment stats for master port only here.
625 	 */
626 	if (port->type == HSR_PT_MASTER) {
627 		port->dev->stats.tx_packets++;
628 		port->dev->stats.tx_bytes += skb->len;
629 	}
630 
631 	kfree_skb(frame.skb_hsr);
632 	kfree_skb(frame.skb_prp);
633 	kfree_skb(frame.skb_std);
634 	return;
635 
636 out_drop:
637 	rcu_read_unlock();
638 	port->dev->stats.tx_dropped++;
639 	kfree_skb(skb);
640 }
641