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(addr1: eth_hdr->h_dest,
48 addr2: 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, len: 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, len: 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, len: total_length))
88 return false;
89 skb_pull(skb, len: total_length);
90 hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
91 skb_push(skb, len: 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, len: total_length))
104 return false;
105
106 /* get next tlv */
107 skb_pull(skb, len: total_length);
108 hsr_sup_tlv = (struct hsr_sup_tlv *)skb->data;
109 skb_push(skb, len: 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: skb_in, HSR_HLEN);
128 skb = __pskb_copy(skb: skb_in, headroom: skb_headroom(skb: skb_in) - HSR_HLEN, GFP_ATOMIC);
129 skb_push(skb: 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: 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(skb_in: 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(skb: 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(skb: frame->skb_prp,
174 len: frame->skb_prp->len - HSR_HLEN);
175 frame->skb_std =
176 __pskb_copy(skb: frame->skb_prp,
177 headroom: skb_headroom(skb: 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(skb: 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(rct: trailer, lan_id: 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, len: 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(rct: trailer, LSDU_size: 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(ht: &hsr_ethhdr->hsr_tag, path: 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(ht: &hsr_ethhdr->hsr_tag, LSDU_size: 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(skb: frame->skb_hsr);
290
291 /* set the lane id properly */
292 hsr_set_path_id(hsr_ethhdr, port);
293 return skb_clone(skb: frame->skb_hsr, GFP_ATOMIC);
294 } else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
295 return skb_clone(skb: frame->skb_std, GFP_ATOMIC);
296 }
297
298 /* Create the new skb with enough headroom to fit the HSR tag */
299 skb = __pskb_copy(skb: frame->skb_std,
300 headroom: skb_headroom(skb: 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, proto_version: 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(skb: 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(skb: frame->skb_prp, GFP_ATOMIC);
338 } else if (port->dev->features & NETIF_F_HW_HSR_TAG_INS) {
339 return skb_clone(skb: frame->skb_std, GFP_ATOMIC);
340 }
341
342 skb = skb_copy_expand(skb: frame->skb_std, newheadroom: 0,
343 newtailroom: skb_tailroom(skb: frame->skb_std) + HSR_HLEN,
344 GFP_ATOMIC);
345 return prp_fill_rct(skb, frame, port);
346}
347
348static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev,
349 struct hsr_node *node_src)
350{
351 bool was_multicast_frame;
352 int res, recv_len;
353
354 was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST);
355 hsr_addr_subst_source(node: node_src, skb);
356 skb_pull(skb, ETH_HLEN);
357 recv_len = skb->len;
358 res = netif_rx(skb);
359 if (res == NET_RX_DROP) {
360 dev->stats.rx_dropped++;
361 } else {
362 dev->stats.rx_packets++;
363 dev->stats.rx_bytes += recv_len;
364 if (was_multicast_frame)
365 dev->stats.multicast++;
366 }
367}
368
369static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port,
370 struct hsr_frame_info *frame)
371{
372 if (frame->port_rcv->type == HSR_PT_MASTER) {
373 hsr_addr_subst_dest(node_src: frame->node_src, skb, port);
374
375 /* Address substitution (IEC62439-3 pp 26, 50): replace mac
376 * address of outgoing frame with that of the outgoing slave's.
377 */
378 ether_addr_copy(dst: eth_hdr(skb)->h_source, src: port->dev->dev_addr);
379 }
380 return dev_queue_xmit(skb);
381}
382
383bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
384{
385 return ((frame->port_rcv->type == HSR_PT_SLAVE_A &&
386 port->type == HSR_PT_SLAVE_B) ||
387 (frame->port_rcv->type == HSR_PT_SLAVE_B &&
388 port->type == HSR_PT_SLAVE_A));
389}
390
391bool hsr_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
392{
393 if (port->dev->features & NETIF_F_HW_HSR_FWD)
394 return prp_drop_frame(frame, port);
395
396 return false;
397}
398
399/* Forward the frame through all devices except:
400 * - Back through the receiving device
401 * - If it's a HSR frame: through a device where it has passed before
402 * - if it's a PRP frame: through another PRP slave device (no bridge)
403 * - To the local HSR master only if the frame is directly addressed to it, or
404 * a non-supervision multicast or broadcast frame.
405 *
406 * HSR slave devices should insert a HSR tag into the frame, or forward the
407 * frame unchanged if it's already tagged. Interlink devices should strip HSR
408 * tags if they're of the non-HSR type (but only after duplicate discard). The
409 * master device always strips HSR tags.
410 */
411static void hsr_forward_do(struct hsr_frame_info *frame)
412{
413 struct hsr_port *port;
414 struct sk_buff *skb;
415 bool sent = false;
416
417 hsr_for_each_port(frame->port_rcv->hsr, port) {
418 struct hsr_priv *hsr = port->hsr;
419 /* Don't send frame back the way it came */
420 if (port == frame->port_rcv)
421 continue;
422
423 /* Don't deliver locally unless we should */
424 if (port->type == HSR_PT_MASTER && !frame->is_local_dest)
425 continue;
426
427 /* Deliver frames directly addressed to us to master only */
428 if (port->type != HSR_PT_MASTER && frame->is_local_exclusive)
429 continue;
430
431 /* If hardware duplicate generation is enabled, only send out
432 * one port.
433 */
434 if ((port->dev->features & NETIF_F_HW_HSR_DUP) && sent)
435 continue;
436
437 /* Don't send frame over port where it has been sent before.
438 * Also for SAN, this shouldn't be done.
439 */
440 if (!frame->is_from_san &&
441 hsr_register_frame_out(port, node: frame->node_src,
442 sequence_nr: frame->sequence_nr))
443 continue;
444
445 if (frame->is_supervision && port->type == HSR_PT_MASTER) {
446 hsr_handle_sup_frame(frame);
447 continue;
448 }
449
450 /* Check if frame is to be dropped. Eg. for PRP no forward
451 * between ports.
452 */
453 if (hsr->proto_ops->drop_frame &&
454 hsr->proto_ops->drop_frame(frame, port))
455 continue;
456
457 if (port->type != HSR_PT_MASTER)
458 skb = hsr->proto_ops->create_tagged_frame(frame, port);
459 else
460 skb = hsr->proto_ops->get_untagged_frame(frame, port);
461
462 if (!skb) {
463 frame->port_rcv->dev->stats.rx_dropped++;
464 continue;
465 }
466
467 skb->dev = port->dev;
468 if (port->type == HSR_PT_MASTER) {
469 hsr_deliver_master(skb, dev: port->dev, node_src: frame->node_src);
470 } else {
471 if (!hsr_xmit(skb, port, frame))
472 sent = true;
473 }
474 }
475}
476
477static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb,
478 struct hsr_frame_info *frame)
479{
480 if (hsr_addr_is_self(hsr, addr: eth_hdr(skb)->h_dest)) {
481 frame->is_local_exclusive = true;
482 skb->pkt_type = PACKET_HOST;
483 } else {
484 frame->is_local_exclusive = false;
485 }
486
487 if (skb->pkt_type == PACKET_HOST ||
488 skb->pkt_type == PACKET_MULTICAST ||
489 skb->pkt_type == PACKET_BROADCAST) {
490 frame->is_local_dest = true;
491 } else {
492 frame->is_local_dest = false;
493 }
494}
495
496static void handle_std_frame(struct sk_buff *skb,
497 struct hsr_frame_info *frame)
498{
499 struct hsr_port *port = frame->port_rcv;
500 struct hsr_priv *hsr = port->hsr;
501
502 frame->skb_hsr = NULL;
503 frame->skb_prp = NULL;
504 frame->skb_std = skb;
505
506 if (port->type != HSR_PT_MASTER) {
507 frame->is_from_san = true;
508 } else {
509 /* Sequence nr for the master node */
510 lockdep_assert_held(&hsr->seqnr_lock);
511 frame->sequence_nr = hsr->sequence_nr;
512 hsr->sequence_nr++;
513 }
514}
515
516int hsr_fill_frame_info(__be16 proto, struct sk_buff *skb,
517 struct hsr_frame_info *frame)
518{
519 struct hsr_port *port = frame->port_rcv;
520 struct hsr_priv *hsr = port->hsr;
521
522 /* HSRv0 supervisory frames double as a tag so treat them as tagged. */
523 if ((!hsr->prot_version && proto == htons(ETH_P_PRP)) ||
524 proto == htons(ETH_P_HSR)) {
525 /* Check if skb contains hsr_ethhdr */
526 if (skb->mac_len < sizeof(struct hsr_ethhdr))
527 return -EINVAL;
528
529 /* HSR tagged frame :- Data or Supervision */
530 frame->skb_std = NULL;
531 frame->skb_prp = NULL;
532 frame->skb_hsr = skb;
533 frame->sequence_nr = hsr_get_skb_sequence_nr(skb);
534 return 0;
535 }
536
537 /* Standard frame or PRP from master port */
538 handle_std_frame(skb, frame);
539
540 return 0;
541}
542
543int prp_fill_frame_info(__be16 proto, struct sk_buff *skb,
544 struct hsr_frame_info *frame)
545{
546 /* Supervision frame */
547 struct prp_rct *rct = skb_get_PRP_rct(skb);
548
549 if (rct &&
550 prp_check_lsdu_size(skb, rct, is_sup: frame->is_supervision)) {
551 frame->skb_hsr = NULL;
552 frame->skb_std = NULL;
553 frame->skb_prp = skb;
554 frame->sequence_nr = prp_get_skb_sequence_nr(rct);
555 return 0;
556 }
557 handle_std_frame(skb, frame);
558
559 return 0;
560}
561
562static int fill_frame_info(struct hsr_frame_info *frame,
563 struct sk_buff *skb, struct hsr_port *port)
564{
565 struct hsr_priv *hsr = port->hsr;
566 struct hsr_vlan_ethhdr *vlan_hdr;
567 struct ethhdr *ethhdr;
568 __be16 proto;
569 int ret;
570
571 /* Check if skb contains ethhdr */
572 if (skb->mac_len < sizeof(struct ethhdr))
573 return -EINVAL;
574
575 memset(frame, 0, sizeof(*frame));
576 frame->is_supervision = is_supervision_frame(hsr: port->hsr, skb);
577 frame->node_src = hsr_get_node(port, node_db: &hsr->node_db, skb,
578 is_sup: frame->is_supervision,
579 rx_port: port->type);
580 if (!frame->node_src)
581 return -1; /* Unknown node and !is_supervision, or no mem */
582
583 ethhdr = (struct ethhdr *)skb_mac_header(skb);
584 frame->is_vlan = false;
585 proto = ethhdr->h_proto;
586
587 if (proto == htons(ETH_P_8021Q))
588 frame->is_vlan = true;
589
590 if (frame->is_vlan) {
591 vlan_hdr = (struct hsr_vlan_ethhdr *)ethhdr;
592 proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto;
593 /* FIXME: */
594 netdev_warn_once(skb->dev, "VLAN not yet supported");
595 return -EINVAL;
596 }
597
598 frame->is_from_san = false;
599 frame->port_rcv = port;
600 ret = hsr->proto_ops->fill_frame_info(proto, skb, frame);
601 if (ret)
602 return ret;
603
604 check_local_dest(hsr: port->hsr, skb, frame);
605
606 return 0;
607}
608
609/* Must be called holding rcu read lock (because of the port parameter) */
610void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
611{
612 struct hsr_frame_info frame;
613
614 rcu_read_lock();
615 if (fill_frame_info(frame: &frame, skb, port) < 0)
616 goto out_drop;
617
618 hsr_register_frame_in(node: frame.node_src, port, sequence_nr: frame.sequence_nr);
619 hsr_forward_do(frame: &frame);
620 rcu_read_unlock();
621 /* Gets called for ingress frames as well as egress from master port.
622 * So check and increment stats for master port only here.
623 */
624 if (port->type == HSR_PT_MASTER) {
625 port->dev->stats.tx_packets++;
626 port->dev->stats.tx_bytes += skb->len;
627 }
628
629 kfree_skb(skb: frame.skb_hsr);
630 kfree_skb(skb: frame.skb_prp);
631 kfree_skb(skb: frame.skb_std);
632 return;
633
634out_drop:
635 rcu_read_unlock();
636 port->dev->stats.tx_dropped++;
637 kfree_skb(skb);
638}
639

source code of linux/net/hsr/hsr_forward.c