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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 += 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
120static 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
149struct 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
167struct 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
190static 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 */
206static 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
236static 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
249static 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 */
280struct 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
323struct 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
350static 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
371static 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
385bool 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
393bool 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 */
413static 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
479static 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
498static 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
518int 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
545int 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
564static 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 }
598
599 frame->is_from_san = false;
600 frame->port_rcv = port;
601 ret = hsr->proto_ops->fill_frame_info(proto, skb, frame);
602 if (ret)
603 return ret;
604
605 check_local_dest(port->hsr, skb, frame);
606
607 return 0;
608}
609
610/* Must be called holding rcu read lock (because of the port parameter) */
611void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
612{
613 struct hsr_frame_info frame;
614
615 rcu_read_lock();
616 if (fill_frame_info(&frame, skb, port) < 0)
617 goto out_drop;
618
619 hsr_register_frame_in(frame.node_src, port, frame.sequence_nr);
620 hsr_forward_do(&frame);
621 rcu_read_unlock();
622 /* Gets called for ingress frames as well as egress from master port.
623 * So check and increment stats for master port only here.
624 */
625 if (port->type == HSR_PT_MASTER) {
626 port->dev->stats.tx_packets++;
627 port->dev->stats.tx_bytes += skb->len;
628 }
629
630 kfree_skb(frame.skb_hsr);
631 kfree_skb(frame.skb_prp);
632 kfree_skb(frame.skb_std);
633 return;
634
635out_drop:
636 rcu_read_unlock();
637 port->dev->stats.tx_dropped++;
638 kfree_skb(skb);
639}
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
8#include "hsr_forward.h"
9#include <linux/types.h>
10#include <linux/skbuff.h>
11#include <linux/etherdevice.h>
12#include <linux/if_vlan.h>
13#include "hsr_main.h"
14#include "hsr_framereg.h"
15
16struct hsr_node;
17
18struct hsr_frame_info {
19 struct sk_buff *skb_std;
20 struct sk_buff *skb_hsr;
21 struct hsr_port *port_rcv;
22 struct hsr_node *node_src;
23 u16 sequence_nr;
24 bool is_supervision;
25 bool is_vlan;
26 bool is_local_dest;
27 bool is_local_exclusive;
28};
29
30/* The uses I can see for these HSR supervision frames are:
31 * 1) Use the frames that are sent after node initialization ("HSR_TLV.Type =
32 * 22") to reset any sequence_nr counters belonging to that node. Useful if
33 * the other node's counter has been reset for some reason.
34 * --
35 * Or not - resetting the counter and bridging the frame would create a
36 * loop, unfortunately.
37 *
38 * 2) Use the LifeCheck frames to detect ring breaks. I.e. if no LifeCheck
39 * frame is received from a particular node, we know something is wrong.
40 * We just register these (as with normal frames) and throw them away.
41 *
42 * 3) Allow different MAC addresses for the two slave interfaces, using the
43 * MacAddressA field.
44 */
45static bool is_supervision_frame(struct hsr_priv *hsr, struct sk_buff *skb)
46{
47 struct ethhdr *eth_hdr;
48 struct hsr_sup_tag *hsr_sup_tag;
49 struct hsrv1_ethhdr_sp *hsr_V1_hdr;
50
51 WARN_ON_ONCE(!skb_mac_header_was_set(skb));
52 eth_hdr = (struct ethhdr *)skb_mac_header(skb);
53
54 /* Correct addr? */
55 if (!ether_addr_equal(eth_hdr->h_dest,
56 hsr->sup_multicast_addr))
57 return false;
58
59 /* Correct ether type?. */
60 if (!(eth_hdr->h_proto == htons(ETH_P_PRP) ||
61 eth_hdr->h_proto == htons(ETH_P_HSR)))
62 return false;
63
64 /* Get the supervision header from correct location. */
65 if (eth_hdr->h_proto == htons(ETH_P_HSR)) { /* Okay HSRv1. */
66 hsr_V1_hdr = (struct hsrv1_ethhdr_sp *)skb_mac_header(skb);
67 if (hsr_V1_hdr->hsr.encap_proto != htons(ETH_P_PRP))
68 return false;
69
70 hsr_sup_tag = &hsr_V1_hdr->hsr_sup;
71 } else {
72 hsr_sup_tag =
73 &((struct hsrv0_ethhdr_sp *)skb_mac_header(skb))->hsr_sup;
74 }
75
76 if (hsr_sup_tag->HSR_TLV_type != HSR_TLV_ANNOUNCE &&
77 hsr_sup_tag->HSR_TLV_type != HSR_TLV_LIFE_CHECK)
78 return false;
79 if (hsr_sup_tag->HSR_TLV_length != 12 &&
80 hsr_sup_tag->HSR_TLV_length != sizeof(struct hsr_sup_payload))
81 return false;
82
83 return true;
84}
85
86static struct sk_buff *create_stripped_skb(struct sk_buff *skb_in,
87 struct hsr_frame_info *frame)
88{
89 struct sk_buff *skb;
90 int copylen;
91 unsigned char *dst, *src;
92
93 skb_pull(skb_in, HSR_HLEN);
94 skb = __pskb_copy(skb_in, skb_headroom(skb_in) - HSR_HLEN, GFP_ATOMIC);
95 skb_push(skb_in, HSR_HLEN);
96 if (!skb)
97 return NULL;
98
99 skb_reset_mac_header(skb);
100
101 if (skb->ip_summed == CHECKSUM_PARTIAL)
102 skb->csum_start -= HSR_HLEN;
103
104 copylen = 2 * ETH_ALEN;
105 if (frame->is_vlan)
106 copylen += VLAN_HLEN;
107 src = skb_mac_header(skb_in);
108 dst = skb_mac_header(skb);
109 memcpy(dst, src, copylen);
110
111 skb->protocol = eth_hdr(skb)->h_proto;
112 return skb;
113}
114
115static struct sk_buff *frame_get_stripped_skb(struct hsr_frame_info *frame,
116 struct hsr_port *port)
117{
118 if (!frame->skb_std)
119 frame->skb_std = create_stripped_skb(frame->skb_hsr, frame);
120 return skb_clone(frame->skb_std, GFP_ATOMIC);
121}
122
123static void hsr_fill_tag(struct sk_buff *skb, struct hsr_frame_info *frame,
124 struct hsr_port *port, u8 proto_version)
125{
126 struct hsr_ethhdr *hsr_ethhdr;
127 int lane_id;
128 int lsdu_size;
129
130 if (port->type == HSR_PT_SLAVE_A)
131 lane_id = 0;
132 else
133 lane_id = 1;
134
135 lsdu_size = skb->len - 14;
136 if (frame->is_vlan)
137 lsdu_size -= 4;
138
139 hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(skb);
140
141 set_hsr_tag_path(&hsr_ethhdr->hsr_tag, lane_id);
142 set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size);
143 hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr);
144 hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
145 hsr_ethhdr->ethhdr.h_proto = htons(proto_version ?
146 ETH_P_HSR : ETH_P_PRP);
147}
148
149static struct sk_buff *create_tagged_skb(struct sk_buff *skb_o,
150 struct hsr_frame_info *frame,
151 struct hsr_port *port)
152{
153 int movelen;
154 unsigned char *dst, *src;
155 struct sk_buff *skb;
156
157 /* Create the new skb with enough headroom to fit the HSR tag */
158 skb = __pskb_copy(skb_o, skb_headroom(skb_o) + HSR_HLEN, GFP_ATOMIC);
159 if (!skb)
160 return NULL;
161 skb_reset_mac_header(skb);
162
163 if (skb->ip_summed == CHECKSUM_PARTIAL)
164 skb->csum_start += HSR_HLEN;
165
166 movelen = ETH_HLEN;
167 if (frame->is_vlan)
168 movelen += VLAN_HLEN;
169
170 src = skb_mac_header(skb);
171 dst = skb_push(skb, HSR_HLEN);
172 memmove(dst, src, movelen);
173 skb_reset_mac_header(skb);
174
175 hsr_fill_tag(skb, frame, port, port->hsr->prot_version);
176
177 return skb;
178}
179
180/* If the original frame was an HSR tagged frame, just clone it to be sent
181 * unchanged. Otherwise, create a private frame especially tagged for 'port'.
182 */
183static struct sk_buff *frame_get_tagged_skb(struct hsr_frame_info *frame,
184 struct hsr_port *port)
185{
186 if (frame->skb_hsr)
187 return skb_clone(frame->skb_hsr, GFP_ATOMIC);
188
189 if (port->type != HSR_PT_SLAVE_A && port->type != HSR_PT_SLAVE_B) {
190 WARN_ONCE(1, "HSR: Bug: trying to create a tagged frame for a non-ring port");
191 return NULL;
192 }
193
194 return create_tagged_skb(frame->skb_std, frame, port);
195}
196
197static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev,
198 struct hsr_node *node_src)
199{
200 bool was_multicast_frame;
201 int res;
202
203 was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST);
204 hsr_addr_subst_source(node_src, skb);
205 skb_pull(skb, ETH_HLEN);
206 res = netif_rx(skb);
207 if (res == NET_RX_DROP) {
208 dev->stats.rx_dropped++;
209 } else {
210 dev->stats.rx_packets++;
211 dev->stats.rx_bytes += skb->len;
212 if (was_multicast_frame)
213 dev->stats.multicast++;
214 }
215}
216
217static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port,
218 struct hsr_frame_info *frame)
219{
220 if (frame->port_rcv->type == HSR_PT_MASTER) {
221 hsr_addr_subst_dest(frame->node_src, skb, port);
222
223 /* Address substitution (IEC62439-3 pp 26, 50): replace mac
224 * address of outgoing frame with that of the outgoing slave's.
225 */
226 ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr);
227 }
228 return dev_queue_xmit(skb);
229}
230
231/* Forward the frame through all devices except:
232 * - Back through the receiving device
233 * - If it's a HSR frame: through a device where it has passed before
234 * - To the local HSR master only if the frame is directly addressed to it, or
235 * a non-supervision multicast or broadcast frame.
236 *
237 * HSR slave devices should insert a HSR tag into the frame, or forward the
238 * frame unchanged if it's already tagged. Interlink devices should strip HSR
239 * tags if they're of the non-HSR type (but only after duplicate discard). The
240 * master device always strips HSR tags.
241 */
242static void hsr_forward_do(struct hsr_frame_info *frame)
243{
244 struct hsr_port *port;
245 struct sk_buff *skb;
246
247 hsr_for_each_port(frame->port_rcv->hsr, port) {
248 /* Don't send frame back the way it came */
249 if (port == frame->port_rcv)
250 continue;
251
252 /* Don't deliver locally unless we should */
253 if (port->type == HSR_PT_MASTER && !frame->is_local_dest)
254 continue;
255
256 /* Deliver frames directly addressed to us to master only */
257 if (port->type != HSR_PT_MASTER && frame->is_local_exclusive)
258 continue;
259
260 /* Don't send frame over port where it has been sent before */
261 if (hsr_register_frame_out(port, frame->node_src,
262 frame->sequence_nr))
263 continue;
264
265 if (frame->is_supervision && port->type == HSR_PT_MASTER) {
266 hsr_handle_sup_frame(frame->skb_hsr,
267 frame->node_src,
268 frame->port_rcv);
269 continue;
270 }
271
272 if (port->type != HSR_PT_MASTER)
273 skb = frame_get_tagged_skb(frame, port);
274 else
275 skb = frame_get_stripped_skb(frame, port);
276 if (!skb) {
277 /* FIXME: Record the dropped frame? */
278 continue;
279 }
280
281 skb->dev = port->dev;
282 if (port->type == HSR_PT_MASTER)
283 hsr_deliver_master(skb, port->dev, frame->node_src);
284 else
285 hsr_xmit(skb, port, frame);
286 }
287}
288
289static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb,
290 struct hsr_frame_info *frame)
291{
292 if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) {
293 frame->is_local_exclusive = true;
294 skb->pkt_type = PACKET_HOST;
295 } else {
296 frame->is_local_exclusive = false;
297 }
298
299 if (skb->pkt_type == PACKET_HOST ||
300 skb->pkt_type == PACKET_MULTICAST ||
301 skb->pkt_type == PACKET_BROADCAST) {
302 frame->is_local_dest = true;
303 } else {
304 frame->is_local_dest = false;
305 }
306}
307
308static int hsr_fill_frame_info(struct hsr_frame_info *frame,
309 struct sk_buff *skb, struct hsr_port *port)
310{
311 struct ethhdr *ethhdr;
312 unsigned long irqflags;
313
314 frame->is_supervision = is_supervision_frame(port->hsr, skb);
315 frame->node_src = hsr_get_node(port, skb, frame->is_supervision);
316 if (!frame->node_src)
317 return -1; /* Unknown node and !is_supervision, or no mem */
318
319 ethhdr = (struct ethhdr *)skb_mac_header(skb);
320 frame->is_vlan = false;
321 if (ethhdr->h_proto == htons(ETH_P_8021Q)) {
322 frame->is_vlan = true;
323 /* FIXME: */
324 WARN_ONCE(1, "HSR: VLAN not yet supported");
325 }
326 if (ethhdr->h_proto == htons(ETH_P_PRP) ||
327 ethhdr->h_proto == htons(ETH_P_HSR)) {
328 frame->skb_std = NULL;
329 frame->skb_hsr = skb;
330 frame->sequence_nr = hsr_get_skb_sequence_nr(skb);
331 } else {
332 frame->skb_std = skb;
333 frame->skb_hsr = NULL;
334 /* Sequence nr for the master node */
335 spin_lock_irqsave(&port->hsr->seqnr_lock, irqflags);
336 frame->sequence_nr = port->hsr->sequence_nr;
337 port->hsr->sequence_nr++;
338 spin_unlock_irqrestore(&port->hsr->seqnr_lock, irqflags);
339 }
340
341 frame->port_rcv = port;
342 check_local_dest(port->hsr, skb, frame);
343
344 return 0;
345}
346
347/* Must be called holding rcu read lock (because of the port parameter) */
348void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
349{
350 struct hsr_frame_info frame;
351
352 if (skb_mac_header(skb) != skb->data) {
353 WARN_ONCE(1, "%s:%d: Malformed frame (port_src %s)\n",
354 __FILE__, __LINE__, port->dev->name);
355 goto out_drop;
356 }
357
358 if (hsr_fill_frame_info(&frame, skb, port) < 0)
359 goto out_drop;
360 hsr_register_frame_in(frame.node_src, port, frame.sequence_nr);
361 hsr_forward_do(&frame);
362 /* Gets called for ingress frames as well as egress from master port.
363 * So check and increment stats for master port only here.
364 */
365 if (port->type == HSR_PT_MASTER) {
366 port->dev->stats.tx_packets++;
367 port->dev->stats.tx_bytes += skb->len;
368 }
369
370 if (frame.skb_hsr)
371 kfree_skb(frame.skb_hsr);
372 if (frame.skb_std)
373 kfree_skb(frame.skb_std);
374 return;
375
376out_drop:
377 port->dev->stats.tx_dropped++;
378 kfree_skb(skb);
379}