blob: 4ebe2aa3e7d3e944295e9d53890e3cb9b7a90139 [file] [log] [blame]
Arvid Brodinf266a682014-07-04 23:41:03 +02001/* Copyright 2011-2014 Autronica Fire and Security AS
2 *
3 * This program is free software; you can redistribute it and/or modify it
4 * under the terms of the GNU General Public License as published by the Free
5 * Software Foundation; either version 2 of the License, or (at your option)
6 * any later version.
7 *
8 * Author(s):
9 * 2011-2014 Arvid Brodin, arvid.brodin@alten.se
10 */
11
12#include "hsr_forward.h"
13#include <linux/types.h>
14#include <linux/skbuff.h>
15#include <linux/etherdevice.h>
16#include <linux/if_vlan.h>
17#include "hsr_main.h"
18#include "hsr_framereg.h"
19
20
21struct hsr_node;
22
23struct hsr_frame_info {
24 struct sk_buff *skb_std;
25 struct sk_buff *skb_hsr;
26 struct hsr_port *port_rcv;
27 struct hsr_node *node_src;
28 u16 sequence_nr;
29 bool is_supervision;
30 bool is_vlan;
31 bool is_local_dest;
32 bool is_local_exclusive;
33};
34
35
36/* The uses I can see for these HSR supervision frames are:
37 * 1) Use the frames that are sent after node initialization ("HSR_TLV.Type =
38 * 22") to reset any sequence_nr counters belonging to that node. Useful if
39 * the other node's counter has been reset for some reason.
40 * --
41 * Or not - resetting the counter and bridging the frame would create a
42 * loop, unfortunately.
43 *
44 * 2) Use the LifeCheck frames to detect ring breaks. I.e. if no LifeCheck
45 * frame is received from a particular node, we know something is wrong.
46 * We just register these (as with normal frames) and throw them away.
47 *
48 * 3) Allow different MAC addresses for the two slave interfaces, using the
49 * MacAddressA field.
50 */
51static bool is_supervision_frame(struct hsr_priv *hsr, struct sk_buff *skb)
52{
Peter Heiseee1c2792016-04-13 13:52:22 +020053 struct ethhdr *ethHdr;
54 struct hsr_sup_tag *hsrSupTag;
55 struct hsrv1_ethhdr_sp *hsrV1Hdr;
Arvid Brodinf266a682014-07-04 23:41:03 +020056
57 WARN_ON_ONCE(!skb_mac_header_was_set(skb));
Peter Heiseee1c2792016-04-13 13:52:22 +020058 ethHdr = (struct ethhdr *) skb_mac_header(skb);
Arvid Brodinf266a682014-07-04 23:41:03 +020059
Peter Heiseee1c2792016-04-13 13:52:22 +020060 /* Correct addr? */
61 if (!ether_addr_equal(ethHdr->h_dest,
Arvid Brodinf266a682014-07-04 23:41:03 +020062 hsr->sup_multicast_addr))
63 return false;
64
Peter Heiseee1c2792016-04-13 13:52:22 +020065 /* Correct ether type?. */
66 if (!(ethHdr->h_proto == htons(ETH_P_PRP)
67 || ethHdr->h_proto == htons(ETH_P_HSR)))
Arvid Brodinf266a682014-07-04 23:41:03 +020068 return false;
Peter Heiseee1c2792016-04-13 13:52:22 +020069
70 /* Get the supervision header from correct location. */
71 if (ethHdr->h_proto == htons(ETH_P_HSR)) { /* Okay HSRv1. */
72 hsrV1Hdr = (struct hsrv1_ethhdr_sp *) skb_mac_header(skb);
73 if (hsrV1Hdr->hsr.encap_proto != htons(ETH_P_PRP))
74 return false;
75
76 hsrSupTag = &hsrV1Hdr->hsr_sup;
77 } else {
78 hsrSupTag = &((struct hsrv0_ethhdr_sp *) skb_mac_header(skb))->hsr_sup;
79 }
80
81 if ((hsrSupTag->HSR_TLV_Type != HSR_TLV_ANNOUNCE) &&
82 (hsrSupTag->HSR_TLV_Type != HSR_TLV_LIFE_CHECK))
Arvid Brodinf266a682014-07-04 23:41:03 +020083 return false;
Peter Heiseee1c2792016-04-13 13:52:22 +020084 if ((hsrSupTag->HSR_TLV_Length != 12) &&
85 (hsrSupTag->HSR_TLV_Length !=
86 sizeof(struct hsr_sup_payload)))
Arvid Brodinf266a682014-07-04 23:41:03 +020087 return false;
88
89 return true;
90}
91
92
93static struct sk_buff *create_stripped_skb(struct sk_buff *skb_in,
94 struct hsr_frame_info *frame)
95{
96 struct sk_buff *skb;
97 int copylen;
98 unsigned char *dst, *src;
99
100 skb_pull(skb_in, HSR_HLEN);
101 skb = __pskb_copy(skb_in, skb_headroom(skb_in) - HSR_HLEN, GFP_ATOMIC);
102 skb_push(skb_in, HSR_HLEN);
103 if (skb == NULL)
104 return NULL;
105
106 skb_reset_mac_header(skb);
107
108 if (skb->ip_summed == CHECKSUM_PARTIAL)
109 skb->csum_start -= HSR_HLEN;
110
111 copylen = 2*ETH_ALEN;
112 if (frame->is_vlan)
113 copylen += VLAN_HLEN;
114 src = skb_mac_header(skb_in);
115 dst = skb_mac_header(skb);
116 memcpy(dst, src, copylen);
117
118 skb->protocol = eth_hdr(skb)->h_proto;
119 return skb;
120}
121
122static struct sk_buff *frame_get_stripped_skb(struct hsr_frame_info *frame,
123 struct hsr_port *port)
124{
125 if (!frame->skb_std)
126 frame->skb_std = create_stripped_skb(frame->skb_hsr, frame);
127 return skb_clone(frame->skb_std, GFP_ATOMIC);
128}
129
130
131static void hsr_fill_tag(struct sk_buff *skb, struct hsr_frame_info *frame,
Peter Heiseee1c2792016-04-13 13:52:22 +0200132 struct hsr_port *port, u8 protoVersion)
Arvid Brodinf266a682014-07-04 23:41:03 +0200133{
134 struct hsr_ethhdr *hsr_ethhdr;
135 int lane_id;
136 int lsdu_size;
137
138 if (port->type == HSR_PT_SLAVE_A)
139 lane_id = 0;
140 else
141 lane_id = 1;
142
143 lsdu_size = skb->len - 14;
144 if (frame->is_vlan)
145 lsdu_size -= 4;
146
147 hsr_ethhdr = (struct hsr_ethhdr *) skb_mac_header(skb);
148
149 set_hsr_tag_path(&hsr_ethhdr->hsr_tag, lane_id);
150 set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size);
151 hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr);
152 hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
Peter Heiseee1c2792016-04-13 13:52:22 +0200153 hsr_ethhdr->ethhdr.h_proto = htons(protoVersion ?
154 ETH_P_HSR : ETH_P_PRP);
Arvid Brodinf266a682014-07-04 23:41:03 +0200155}
156
157static struct sk_buff *create_tagged_skb(struct sk_buff *skb_o,
158 struct hsr_frame_info *frame,
159 struct hsr_port *port)
160{
161 int movelen;
162 unsigned char *dst, *src;
163 struct sk_buff *skb;
164
165 /* Create the new skb with enough headroom to fit the HSR tag */
166 skb = __pskb_copy(skb_o, skb_headroom(skb_o) + HSR_HLEN, GFP_ATOMIC);
167 if (skb == NULL)
168 return NULL;
169 skb_reset_mac_header(skb);
170
171 if (skb->ip_summed == CHECKSUM_PARTIAL)
172 skb->csum_start += HSR_HLEN;
173
174 movelen = ETH_HLEN;
175 if (frame->is_vlan)
176 movelen += VLAN_HLEN;
177
178 src = skb_mac_header(skb);
179 dst = skb_push(skb, HSR_HLEN);
180 memmove(dst, src, movelen);
181 skb_reset_mac_header(skb);
182
Peter Heiseee1c2792016-04-13 13:52:22 +0200183 hsr_fill_tag(skb, frame, port, port->hsr->protVersion);
Arvid Brodinf266a682014-07-04 23:41:03 +0200184
185 return skb;
186}
187
188/* If the original frame was an HSR tagged frame, just clone it to be sent
189 * unchanged. Otherwise, create a private frame especially tagged for 'port'.
190 */
191static struct sk_buff *frame_get_tagged_skb(struct hsr_frame_info *frame,
192 struct hsr_port *port)
193{
194 if (frame->skb_hsr)
195 return skb_clone(frame->skb_hsr, GFP_ATOMIC);
196
197 if ((port->type != HSR_PT_SLAVE_A) && (port->type != HSR_PT_SLAVE_B)) {
198 WARN_ONCE(1, "HSR: Bug: trying to create a tagged frame for a non-ring port");
199 return NULL;
200 }
201
202 return create_tagged_skb(frame->skb_std, frame, port);
203}
204
205
206static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev,
207 struct hsr_node *node_src)
208{
209 bool was_multicast_frame;
210 int res;
211
212 was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST);
213 hsr_addr_subst_source(node_src, skb);
214 skb_pull(skb, ETH_HLEN);
215 res = netif_rx(skb);
216 if (res == NET_RX_DROP) {
217 dev->stats.rx_dropped++;
218 } else {
219 dev->stats.rx_packets++;
220 dev->stats.rx_bytes += skb->len;
221 if (was_multicast_frame)
222 dev->stats.multicast++;
223 }
224}
225
226static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port,
227 struct hsr_frame_info *frame)
228{
229 if (frame->port_rcv->type == HSR_PT_MASTER) {
230 hsr_addr_subst_dest(frame->node_src, skb, port);
231
232 /* Address substitution (IEC62439-3 pp 26, 50): replace mac
233 * address of outgoing frame with that of the outgoing slave's.
234 */
235 ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr);
236 }
237 return dev_queue_xmit(skb);
238}
239
240
241/* Forward the frame through all devices except:
242 * - Back through the receiving device
243 * - If it's a HSR frame: through a device where it has passed before
244 * - To the local HSR master only if the frame is directly addressed to it, or
245 * a non-supervision multicast or broadcast frame.
246 *
247 * HSR slave devices should insert a HSR tag into the frame, or forward the
248 * frame unchanged if it's already tagged. Interlink devices should strip HSR
249 * tags if they're of the non-HSR type (but only after duplicate discard). The
250 * master device always strips HSR tags.
251 */
252static void hsr_forward_do(struct hsr_frame_info *frame)
253{
254 struct hsr_port *port;
255 struct sk_buff *skb;
256
257 hsr_for_each_port(frame->port_rcv->hsr, port) {
258 /* Don't send frame back the way it came */
259 if (port == frame->port_rcv)
260 continue;
261
262 /* Don't deliver locally unless we should */
263 if ((port->type == HSR_PT_MASTER) && !frame->is_local_dest)
264 continue;
265
266 /* Deliver frames directly addressed to us to master only */
267 if ((port->type != HSR_PT_MASTER) && frame->is_local_exclusive)
268 continue;
269
270 /* Don't send frame over port where it has been sent before */
271 if (hsr_register_frame_out(port, frame->node_src,
272 frame->sequence_nr))
273 continue;
274
275 if (frame->is_supervision && (port->type == HSR_PT_MASTER)) {
276 hsr_handle_sup_frame(frame->skb_hsr,
277 frame->node_src,
278 frame->port_rcv);
279 continue;
280 }
281
282 if (port->type != HSR_PT_MASTER)
283 skb = frame_get_tagged_skb(frame, port);
284 else
285 skb = frame_get_stripped_skb(frame, port);
286 if (skb == NULL) {
287 /* FIXME: Record the dropped frame? */
288 continue;
289 }
290
291 skb->dev = port->dev;
292 if (port->type == HSR_PT_MASTER)
293 hsr_deliver_master(skb, port->dev, frame->node_src);
294 else
295 hsr_xmit(skb, port, frame);
296 }
297}
298
299
300static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb,
301 struct hsr_frame_info *frame)
302{
Arvid Brodinf266a682014-07-04 23:41:03 +0200303 if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) {
304 frame->is_local_exclusive = true;
305 skb->pkt_type = PACKET_HOST;
306 } else {
307 frame->is_local_exclusive = false;
308 }
309
310 if ((skb->pkt_type == PACKET_HOST) ||
311 (skb->pkt_type == PACKET_MULTICAST) ||
312 (skb->pkt_type == PACKET_BROADCAST)) {
313 frame->is_local_dest = true;
314 } else {
315 frame->is_local_dest = false;
316 }
317}
318
319
320static int hsr_fill_frame_info(struct hsr_frame_info *frame,
321 struct sk_buff *skb, struct hsr_port *port)
322{
323 struct ethhdr *ethhdr;
324 unsigned long irqflags;
325
326 frame->is_supervision = is_supervision_frame(port->hsr, skb);
327 frame->node_src = hsr_get_node(&port->hsr->node_db, skb,
328 frame->is_supervision);
329 if (frame->node_src == NULL)
330 return -1; /* Unknown node and !is_supervision, or no mem */
331
332 ethhdr = (struct ethhdr *) skb_mac_header(skb);
333 frame->is_vlan = false;
334 if (ethhdr->h_proto == htons(ETH_P_8021Q)) {
335 frame->is_vlan = true;
336 /* FIXME: */
337 WARN_ONCE(1, "HSR: VLAN not yet supported");
338 }
Peter Heiseee1c2792016-04-13 13:52:22 +0200339 if (ethhdr->h_proto == htons(ETH_P_PRP)
340 || ethhdr->h_proto == htons(ETH_P_HSR)) {
Arvid Brodinf266a682014-07-04 23:41:03 +0200341 frame->skb_std = NULL;
342 frame->skb_hsr = skb;
343 frame->sequence_nr = hsr_get_skb_sequence_nr(skb);
344 } else {
345 frame->skb_std = skb;
346 frame->skb_hsr = NULL;
347 /* Sequence nr for the master node */
348 spin_lock_irqsave(&port->hsr->seqnr_lock, irqflags);
349 frame->sequence_nr = port->hsr->sequence_nr;
350 port->hsr->sequence_nr++;
351 spin_unlock_irqrestore(&port->hsr->seqnr_lock, irqflags);
352 }
353
354 frame->port_rcv = port;
355 check_local_dest(port->hsr, skb, frame);
356
357 return 0;
358}
359
360/* Must be called holding rcu read lock (because of the port parameter) */
361void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
362{
363 struct hsr_frame_info frame;
364
365 if (skb_mac_header(skb) != skb->data) {
366 WARN_ONCE(1, "%s:%d: Malformed frame (port_src %s)\n",
367 __FILE__, __LINE__, port->dev->name);
368 goto out_drop;
369 }
370
371 if (hsr_fill_frame_info(&frame, skb, port) < 0)
372 goto out_drop;
373 hsr_register_frame_in(frame.node_src, port, frame.sequence_nr);
374 hsr_forward_do(&frame);
375
376 if (frame.skb_hsr != NULL)
377 kfree_skb(frame.skb_hsr);
378 if (frame.skb_std != NULL)
379 kfree_skb(frame.skb_std);
380 return;
381
382out_drop:
383 port->dev->stats.tx_dropped++;
384 kfree_skb(skb);
385}