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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
41 WARN_ON_ONCE(!skb_mac_header_was_set(skb));
42 eth_hdr = (struct ethhdr *)skb_mac_header(skb);
43
44 /* Correct addr? */
45 if (!ether_addr_equal(eth_hdr->h_dest,
46 hsr->sup_multicast_addr))
47 return false;
48
49 /* Correct ether type?. */
50 if (!(eth_hdr->h_proto == htons(ETH_P_PRP) ||
51 eth_hdr->h_proto == htons(ETH_P_HSR)))
52 return false;
53
54 /* Get the supervision header from correct location. */
55 if (eth_hdr->h_proto == htons(ETH_P_HSR)) { /* Okay HSRv1. */
56 hsr_V1_hdr = (struct hsrv1_ethhdr_sp *)skb_mac_header(skb);
57 if (hsr_V1_hdr->hsr.encap_proto != htons(ETH_P_PRP))
58 return false;
59
60 hsr_sup_tag = &hsr_V1_hdr->hsr_sup;
61 } else {
62 hsr_sup_tag =
63 &((struct hsrv0_ethhdr_sp *)skb_mac_header(skb))->hsr_sup;
64 }
65
66 if (hsr_sup_tag->HSR_TLV_type != HSR_TLV_ANNOUNCE &&
67 hsr_sup_tag->HSR_TLV_type != HSR_TLV_LIFE_CHECK &&
68 hsr_sup_tag->HSR_TLV_type != PRP_TLV_LIFE_CHECK_DD &&
69 hsr_sup_tag->HSR_TLV_type != PRP_TLV_LIFE_CHECK_DA)
70 return false;
71 if (hsr_sup_tag->HSR_TLV_length != 12 &&
72 hsr_sup_tag->HSR_TLV_length != sizeof(struct hsr_sup_payload))
73 return false;
74
75 return true;
76}
77
78static struct sk_buff *create_stripped_skb_hsr(struct sk_buff *skb_in,
79 struct hsr_frame_info *frame)
80{
81 struct sk_buff *skb;
82 int copylen;
83 unsigned char *dst, *src;
84
85 skb_pull(skb_in, HSR_HLEN);
86 skb = __pskb_copy(skb_in, skb_headroom(skb_in) - HSR_HLEN, GFP_ATOMIC);
87 skb_push(skb_in, HSR_HLEN);
88 if (!skb)
89 return NULL;
90
91 skb_reset_mac_header(skb);
92
93 if (skb->ip_summed == CHECKSUM_PARTIAL)
94 skb->csum_start -= HSR_HLEN;
95
96 copylen = 2 * ETH_ALEN;
97 if (frame->is_vlan)
98 copylen += VLAN_HLEN;
99 src = skb_mac_header(skb_in);
100 dst = skb_mac_header(skb);
101 memcpy(dst, src, copylen);
102
103 skb->protocol = eth_hdr(skb)->h_proto;
104 return skb;
105}
106
107struct sk_buff *hsr_get_untagged_frame(struct hsr_frame_info *frame,
108 struct hsr_port *port)
109{
110 if (!frame->skb_std) {
111 if (frame->skb_hsr) {
112 frame->skb_std =
113 create_stripped_skb_hsr(frame->skb_hsr, frame);
114 } else {
115 /* Unexpected */
116 WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n",
117 __FILE__, __LINE__, port->dev->name);
118 return NULL;
119 }
120 }
121
122 return skb_clone(frame->skb_std, GFP_ATOMIC);
123}
124
125struct sk_buff *prp_get_untagged_frame(struct hsr_frame_info *frame,
126 struct hsr_port *port)
127{
128 if (!frame->skb_std) {
129 if (frame->skb_prp) {
130 /* trim the skb by len - HSR_HLEN to exclude RCT */
131 skb_trim(frame->skb_prp,
132 frame->skb_prp->len - HSR_HLEN);
133 frame->skb_std =
134 __pskb_copy(frame->skb_prp,
135 skb_headroom(frame->skb_prp),
136 GFP_ATOMIC);
137 } else {
138 /* Unexpected */
139 WARN_ONCE(1, "%s:%d: Unexpected frame received (port_src %s)\n",
140 __FILE__, __LINE__, port->dev->name);
141 return NULL;
142 }
143 }
144
145 return skb_clone(frame->skb_std, GFP_ATOMIC);
146}
147
148static void prp_set_lan_id(struct prp_rct *trailer,
149 struct hsr_port *port)
150{
151 int lane_id;
152
153 if (port->type == HSR_PT_SLAVE_A)
154 lane_id = 0;
155 else
156 lane_id = 1;
157
158 /* Add net_id in the upper 3 bits of lane_id */
159 lane_id |= port->hsr->net_id;
160 set_prp_lan_id(trailer, lane_id);
161}
162
163/* Tailroom for PRP rct should have been created before calling this */
164static struct sk_buff *prp_fill_rct(struct sk_buff *skb,
165 struct hsr_frame_info *frame,
166 struct hsr_port *port)
167{
168 struct prp_rct *trailer;
169 int min_size = ETH_ZLEN;
170 int lsdu_size;
171
172 if (!skb)
173 return skb;
174
175 if (frame->is_vlan)
176 min_size = VLAN_ETH_ZLEN;
177
178 if (skb_put_padto(skb, min_size))
179 return NULL;
180
181 trailer = (struct prp_rct *)skb_put(skb, HSR_HLEN);
182 lsdu_size = skb->len - 14;
183 if (frame->is_vlan)
184 lsdu_size -= 4;
185 prp_set_lan_id(trailer, port);
186 set_prp_LSDU_size(trailer, lsdu_size);
187 trailer->sequence_nr = htons(frame->sequence_nr);
188 trailer->PRP_suffix = htons(ETH_P_PRP);
189
190 return skb;
191}
192
193static void hsr_set_path_id(struct hsr_ethhdr *hsr_ethhdr,
194 struct hsr_port *port)
195{
196 int path_id;
197
198 if (port->type == HSR_PT_SLAVE_A)
199 path_id = 0;
200 else
201 path_id = 1;
202
203 set_hsr_tag_path(&hsr_ethhdr->hsr_tag, path_id);
204}
205
206static struct sk_buff *hsr_fill_tag(struct sk_buff *skb,
207 struct hsr_frame_info *frame,
208 struct hsr_port *port, u8 proto_version)
209{
210 struct hsr_ethhdr *hsr_ethhdr;
211 int lsdu_size;
212
213 /* pad to minimum packet size which is 60 + 6 (HSR tag) */
214 if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
215 return NULL;
216
217 lsdu_size = skb->len - 14;
218 if (frame->is_vlan)
219 lsdu_size -= 4;
220
221 hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(skb);
222
223 hsr_set_path_id(hsr_ethhdr, port);
224 set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size);
225 hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr);
226 hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
227 hsr_ethhdr->ethhdr.h_proto = htons(proto_version ?
228 ETH_P_HSR : ETH_P_PRP);
229
230 return skb;
231}
232
233/* If the original frame was an HSR tagged frame, just clone it to be sent
234 * unchanged. Otherwise, create a private frame especially tagged for 'port'.
235 */
236struct sk_buff *hsr_create_tagged_frame(struct hsr_frame_info *frame,
237 struct hsr_port *port)
238{
239 unsigned char *dst, *src;
240 struct sk_buff *skb;
241 int movelen;
242
243 if (frame->skb_hsr) {
244 struct hsr_ethhdr *hsr_ethhdr =
245 (struct hsr_ethhdr *)skb_mac_header(frame->skb_hsr);
246
247 /* set the lane id properly */
248 hsr_set_path_id(hsr_ethhdr, port);
249 return skb_clone(frame->skb_hsr, GFP_ATOMIC);
250 }
251
252 /* Create the new skb with enough headroom to fit the HSR tag */
253 skb = __pskb_copy(frame->skb_std,
254 skb_headroom(frame->skb_std) + HSR_HLEN, GFP_ATOMIC);
255 if (!skb)
256 return NULL;
257 skb_reset_mac_header(skb);
258
259 if (skb->ip_summed == CHECKSUM_PARTIAL)
260 skb->csum_start += HSR_HLEN;
261
262 movelen = ETH_HLEN;
263 if (frame->is_vlan)
264 movelen += VLAN_HLEN;
265
266 src = skb_mac_header(skb);
267 dst = skb_push(skb, HSR_HLEN);
268 memmove(dst, src, movelen);
269 skb_reset_mac_header(skb);
270
271 /* skb_put_padto free skb on error and hsr_fill_tag returns NULL in
272 * that case
273 */
274 return hsr_fill_tag(skb, frame, port, port->hsr->prot_version);
275}
276
277struct sk_buff *prp_create_tagged_frame(struct hsr_frame_info *frame,
278 struct hsr_port *port)
279{
280 struct sk_buff *skb;
281
282 if (frame->skb_prp) {
283 struct prp_rct *trailer = skb_get_PRP_rct(frame->skb_prp);
284
285 if (trailer) {
286 prp_set_lan_id(trailer, port);
287 } else {
288 WARN_ONCE(!trailer, "errored PRP skb");
289 return NULL;
290 }
291 return skb_clone(frame->skb_prp, GFP_ATOMIC);
292 }
293
294 skb = skb_copy_expand(frame->skb_std, 0,
295 skb_tailroom(frame->skb_std) + HSR_HLEN,
296 GFP_ATOMIC);
297 prp_fill_rct(skb, frame, port);
298
299 return skb;
300}
301
302static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev,
303 struct hsr_node *node_src)
304{
305 bool was_multicast_frame;
306 int res;
307
308 was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST);
309 hsr_addr_subst_source(node_src, skb);
310 skb_pull(skb, ETH_HLEN);
311 res = netif_rx(skb);
312 if (res == NET_RX_DROP) {
313 dev->stats.rx_dropped++;
314 } else {
315 dev->stats.rx_packets++;
316 dev->stats.rx_bytes += skb->len;
317 if (was_multicast_frame)
318 dev->stats.multicast++;
319 }
320}
321
322static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port,
323 struct hsr_frame_info *frame)
324{
325 if (frame->port_rcv->type == HSR_PT_MASTER) {
326 hsr_addr_subst_dest(frame->node_src, skb, port);
327
328 /* Address substitution (IEC62439-3 pp 26, 50): replace mac
329 * address of outgoing frame with that of the outgoing slave's.
330 */
331 ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr);
332 }
333 return dev_queue_xmit(skb);
334}
335
336bool prp_drop_frame(struct hsr_frame_info *frame, struct hsr_port *port)
337{
338 return ((frame->port_rcv->type == HSR_PT_SLAVE_A &&
339 port->type == HSR_PT_SLAVE_B) ||
340 (frame->port_rcv->type == HSR_PT_SLAVE_B &&
341 port->type == HSR_PT_SLAVE_A));
342}
343
344/* Forward the frame through all devices except:
345 * - Back through the receiving device
346 * - If it's a HSR frame: through a device where it has passed before
347 * - if it's a PRP frame: through another PRP slave device (no bridge)
348 * - To the local HSR master only if the frame is directly addressed to it, or
349 * a non-supervision multicast or broadcast frame.
350 *
351 * HSR slave devices should insert a HSR tag into the frame, or forward the
352 * frame unchanged if it's already tagged. Interlink devices should strip HSR
353 * tags if they're of the non-HSR type (but only after duplicate discard). The
354 * master device always strips HSR tags.
355 */
356static void hsr_forward_do(struct hsr_frame_info *frame)
357{
358 struct hsr_port *port;
359 struct sk_buff *skb;
360
361 hsr_for_each_port(frame->port_rcv->hsr, port) {
362 struct hsr_priv *hsr = port->hsr;
363 /* Don't send frame back the way it came */
364 if (port == frame->port_rcv)
365 continue;
366
367 /* Don't deliver locally unless we should */
368 if (port->type == HSR_PT_MASTER && !frame->is_local_dest)
369 continue;
370
371 /* Deliver frames directly addressed to us to master only */
372 if (port->type != HSR_PT_MASTER && frame->is_local_exclusive)
373 continue;
374
375 /* Don't send frame over port where it has been sent before.
376 * Also fro SAN, this shouldn't be done.
377 */
378 if (!frame->is_from_san &&
379 hsr_register_frame_out(port, frame->node_src,
380 frame->sequence_nr))
381 continue;
382
383 if (frame->is_supervision && port->type == HSR_PT_MASTER) {
384 hsr_handle_sup_frame(frame);
385 continue;
386 }
387
388 /* Check if frame is to be dropped. Eg. for PRP no forward
389 * between ports.
390 */
391 if (hsr->proto_ops->drop_frame &&
392 hsr->proto_ops->drop_frame(frame, port))
393 continue;
394
395 if (port->type != HSR_PT_MASTER)
396 skb = hsr->proto_ops->create_tagged_frame(frame, port);
397 else
398 skb = hsr->proto_ops->get_untagged_frame(frame, port);
399
400 if (!skb) {
401 frame->port_rcv->dev->stats.rx_dropped++;
402 continue;
403 }
404
405 skb->dev = port->dev;
406 if (port->type == HSR_PT_MASTER)
407 hsr_deliver_master(skb, port->dev, frame->node_src);
408 else
409 hsr_xmit(skb, port, frame);
410 }
411}
412
413static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb,
414 struct hsr_frame_info *frame)
415{
416 if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) {
417 frame->is_local_exclusive = true;
418 skb->pkt_type = PACKET_HOST;
419 } else {
420 frame->is_local_exclusive = false;
421 }
422
423 if (skb->pkt_type == PACKET_HOST ||
424 skb->pkt_type == PACKET_MULTICAST ||
425 skb->pkt_type == PACKET_BROADCAST) {
426 frame->is_local_dest = true;
427 } else {
428 frame->is_local_dest = false;
429 }
430}
431
432static void handle_std_frame(struct sk_buff *skb,
433 struct hsr_frame_info *frame)
434{
435 struct hsr_port *port = frame->port_rcv;
436 struct hsr_priv *hsr = port->hsr;
437 unsigned long irqflags;
438
439 frame->skb_hsr = NULL;
440 frame->skb_prp = NULL;
441 frame->skb_std = skb;
442
443 if (port->type != HSR_PT_MASTER) {
444 frame->is_from_san = true;
445 } else {
446 /* Sequence nr for the master node */
447 spin_lock_irqsave(&hsr->seqnr_lock, irqflags);
448 frame->sequence_nr = hsr->sequence_nr;
449 hsr->sequence_nr++;
450 spin_unlock_irqrestore(&hsr->seqnr_lock, irqflags);
451 }
452}
453
454void hsr_fill_frame_info(__be16 proto, struct sk_buff *skb,
455 struct hsr_frame_info *frame)
456{
457 if (proto == htons(ETH_P_PRP) ||
458 proto == htons(ETH_P_HSR)) {
459 /* HSR tagged frame :- Data or Supervision */
460 frame->skb_std = NULL;
461 frame->skb_prp = NULL;
462 frame->skb_hsr = skb;
463 frame->sequence_nr = hsr_get_skb_sequence_nr(skb);
464 return;
465 }
466
467 /* Standard frame or PRP from master port */
468 handle_std_frame(skb, frame);
469}
470
471void prp_fill_frame_info(__be16 proto, struct sk_buff *skb,
472 struct hsr_frame_info *frame)
473{
474 /* Supervision frame */
475 struct prp_rct *rct = skb_get_PRP_rct(skb);
476
477 if (rct &&
478 prp_check_lsdu_size(skb, rct, frame->is_supervision)) {
479 frame->skb_hsr = NULL;
480 frame->skb_std = NULL;
481 frame->skb_prp = skb;
482 frame->sequence_nr = prp_get_skb_sequence_nr(rct);
483 return;
484 }
485 handle_std_frame(skb, frame);
486}
487
488static int fill_frame_info(struct hsr_frame_info *frame,
489 struct sk_buff *skb, struct hsr_port *port)
490{
491 struct hsr_priv *hsr = port->hsr;
492 struct hsr_vlan_ethhdr *vlan_hdr;
493 struct ethhdr *ethhdr;
494 __be16 proto;
495
496 memset(frame, 0, sizeof(*frame));
497 frame->is_supervision = is_supervision_frame(port->hsr, skb);
498 frame->node_src = hsr_get_node(port, &hsr->node_db, skb,
499 frame->is_supervision,
500 port->type);
501 if (!frame->node_src)
502 return -1; /* Unknown node and !is_supervision, or no mem */
503
504 ethhdr = (struct ethhdr *)skb_mac_header(skb);
505 frame->is_vlan = false;
506 proto = ethhdr->h_proto;
507
508 if (proto == htons(ETH_P_8021Q))
509 frame->is_vlan = true;
510
511 if (frame->is_vlan) {
512 vlan_hdr = (struct hsr_vlan_ethhdr *)ethhdr;
513 proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto;
514 /* FIXME: */
515 netdev_warn_once(skb->dev, "VLAN not yet supported");
516 }
517
518 frame->is_from_san = false;
519 frame->port_rcv = port;
520 hsr->proto_ops->fill_frame_info(proto, skb, frame);
521 check_local_dest(port->hsr, skb, frame);
522
523 return 0;
524}
525
526/* Must be called holding rcu read lock (because of the port parameter) */
527void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
528{
529 struct hsr_frame_info frame;
530
531 if (skb_mac_header(skb) != skb->data) {
532 WARN_ONCE(1, "%s:%d: Malformed frame (port_src %s)\n",
533 __FILE__, __LINE__, port->dev->name);
534 goto out_drop;
535 }
536
537 if (fill_frame_info(&frame, skb, port) < 0)
538 goto out_drop;
539
540 hsr_register_frame_in(frame.node_src, port, frame.sequence_nr);
541 hsr_forward_do(&frame);
542 /* Gets called for ingress frames as well as egress from master port.
543 * So check and increment stats for master port only here.
544 */
545 if (port->type == HSR_PT_MASTER) {
546 port->dev->stats.tx_packets++;
547 port->dev->stats.tx_bytes += skb->len;
548 }
549
550 kfree_skb(frame.skb_hsr);
551 kfree_skb(frame.skb_prp);
552 kfree_skb(frame.skb_std);
553 return;
554
555out_drop:
556 port->dev->stats.tx_dropped++;
557 kfree_skb(skb);
558}