xref: /linux/net/hsr/hsr_forward.c (revision db6b35cffe59c619ea3772b21d7c7c8a7b885dc1)
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 			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 
221 static 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 */
237 static 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 
267 static 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 
288 static 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  */
331 struct 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 
374 struct 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 
399 static 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 
420 static 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 
443 bool 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 
451 bool 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  */
519 static 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 
589 static 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 
608 static 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 
630 int 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 
657 int 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 
676 static 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) */
734 void 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 
758 out_drop:
759 	rcu_read_unlock();
760 	port->dev->stats.tx_dropped++;
761 	kfree_skb(skb);
762 }
763