blob: 7871ed6d38256c3cdaed0733744af58750372dd5 [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{
53 struct hsr_ethhdr_sp *hdr;
54
55 WARN_ON_ONCE(!skb_mac_header_was_set(skb));
56 hdr = (struct hsr_ethhdr_sp *) skb_mac_header(skb);
57
58 if (!ether_addr_equal(hdr->ethhdr.h_dest,
59 hsr->sup_multicast_addr))
60 return false;
61
62 if (get_hsr_stag_path(&hdr->hsr_sup) != 0x0f)
63 return false;
64 if ((hdr->hsr_sup.HSR_TLV_Type != HSR_TLV_ANNOUNCE) &&
65 (hdr->hsr_sup.HSR_TLV_Type != HSR_TLV_LIFE_CHECK))
66 return false;
67 if (hdr->hsr_sup.HSR_TLV_Length != 12)
68 return false;
69
70 return true;
71}
72
73
74static struct sk_buff *create_stripped_skb(struct sk_buff *skb_in,
75 struct hsr_frame_info *frame)
76{
77 struct sk_buff *skb;
78 int copylen;
79 unsigned char *dst, *src;
80
81 skb_pull(skb_in, HSR_HLEN);
82 skb = __pskb_copy(skb_in, skb_headroom(skb_in) - HSR_HLEN, GFP_ATOMIC);
83 skb_push(skb_in, HSR_HLEN);
84 if (skb == NULL)
85 return NULL;
86
87 skb_reset_mac_header(skb);
88
89 if (skb->ip_summed == CHECKSUM_PARTIAL)
90 skb->csum_start -= HSR_HLEN;
91
92 copylen = 2*ETH_ALEN;
93 if (frame->is_vlan)
94 copylen += VLAN_HLEN;
95 src = skb_mac_header(skb_in);
96 dst = skb_mac_header(skb);
97 memcpy(dst, src, copylen);
98
99 skb->protocol = eth_hdr(skb)->h_proto;
100 return skb;
101}
102
103static struct sk_buff *frame_get_stripped_skb(struct hsr_frame_info *frame,
104 struct hsr_port *port)
105{
106 if (!frame->skb_std)
107 frame->skb_std = create_stripped_skb(frame->skb_hsr, frame);
108 return skb_clone(frame->skb_std, GFP_ATOMIC);
109}
110
111
112static void hsr_fill_tag(struct sk_buff *skb, struct hsr_frame_info *frame,
113 struct hsr_port *port)
114{
115 struct hsr_ethhdr *hsr_ethhdr;
116 int lane_id;
117 int lsdu_size;
118
119 if (port->type == HSR_PT_SLAVE_A)
120 lane_id = 0;
121 else
122 lane_id = 1;
123
124 lsdu_size = skb->len - 14;
125 if (frame->is_vlan)
126 lsdu_size -= 4;
127
128 hsr_ethhdr = (struct hsr_ethhdr *) skb_mac_header(skb);
129
130 set_hsr_tag_path(&hsr_ethhdr->hsr_tag, lane_id);
131 set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size);
132 hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr);
133 hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto;
134 hsr_ethhdr->ethhdr.h_proto = htons(ETH_P_PRP);
135}
136
137static struct sk_buff *create_tagged_skb(struct sk_buff *skb_o,
138 struct hsr_frame_info *frame,
139 struct hsr_port *port)
140{
141 int movelen;
142 unsigned char *dst, *src;
143 struct sk_buff *skb;
144
145 /* Create the new skb with enough headroom to fit the HSR tag */
146 skb = __pskb_copy(skb_o, skb_headroom(skb_o) + HSR_HLEN, GFP_ATOMIC);
147 if (skb == NULL)
148 return NULL;
149 skb_reset_mac_header(skb);
150
151 if (skb->ip_summed == CHECKSUM_PARTIAL)
152 skb->csum_start += HSR_HLEN;
153
154 movelen = ETH_HLEN;
155 if (frame->is_vlan)
156 movelen += VLAN_HLEN;
157
158 src = skb_mac_header(skb);
159 dst = skb_push(skb, HSR_HLEN);
160 memmove(dst, src, movelen);
161 skb_reset_mac_header(skb);
162
163 hsr_fill_tag(skb, frame, port);
164
165 return skb;
166}
167
168/* If the original frame was an HSR tagged frame, just clone it to be sent
169 * unchanged. Otherwise, create a private frame especially tagged for 'port'.
170 */
171static struct sk_buff *frame_get_tagged_skb(struct hsr_frame_info *frame,
172 struct hsr_port *port)
173{
174 if (frame->skb_hsr)
175 return skb_clone(frame->skb_hsr, GFP_ATOMIC);
176
177 if ((port->type != HSR_PT_SLAVE_A) && (port->type != HSR_PT_SLAVE_B)) {
178 WARN_ONCE(1, "HSR: Bug: trying to create a tagged frame for a non-ring port");
179 return NULL;
180 }
181
182 return create_tagged_skb(frame->skb_std, frame, port);
183}
184
185
186static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev,
187 struct hsr_node *node_src)
188{
189 bool was_multicast_frame;
190 int res;
191
192 was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST);
193 hsr_addr_subst_source(node_src, skb);
194 skb_pull(skb, ETH_HLEN);
195 res = netif_rx(skb);
196 if (res == NET_RX_DROP) {
197 dev->stats.rx_dropped++;
198 } else {
199 dev->stats.rx_packets++;
200 dev->stats.rx_bytes += skb->len;
201 if (was_multicast_frame)
202 dev->stats.multicast++;
203 }
204}
205
206static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port,
207 struct hsr_frame_info *frame)
208{
209 if (frame->port_rcv->type == HSR_PT_MASTER) {
210 hsr_addr_subst_dest(frame->node_src, skb, port);
211
212 /* Address substitution (IEC62439-3 pp 26, 50): replace mac
213 * address of outgoing frame with that of the outgoing slave's.
214 */
215 ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr);
216 }
217 return dev_queue_xmit(skb);
218}
219
220
221/* Forward the frame through all devices except:
222 * - Back through the receiving device
223 * - If it's a HSR frame: through a device where it has passed before
224 * - To the local HSR master only if the frame is directly addressed to it, or
225 * a non-supervision multicast or broadcast frame.
226 *
227 * HSR slave devices should insert a HSR tag into the frame, or forward the
228 * frame unchanged if it's already tagged. Interlink devices should strip HSR
229 * tags if they're of the non-HSR type (but only after duplicate discard). The
230 * master device always strips HSR tags.
231 */
232static void hsr_forward_do(struct hsr_frame_info *frame)
233{
234 struct hsr_port *port;
235 struct sk_buff *skb;
236
237 hsr_for_each_port(frame->port_rcv->hsr, port) {
238 /* Don't send frame back the way it came */
239 if (port == frame->port_rcv)
240 continue;
241
242 /* Don't deliver locally unless we should */
243 if ((port->type == HSR_PT_MASTER) && !frame->is_local_dest)
244 continue;
245
246 /* Deliver frames directly addressed to us to master only */
247 if ((port->type != HSR_PT_MASTER) && frame->is_local_exclusive)
248 continue;
249
250 /* Don't send frame over port where it has been sent before */
251 if (hsr_register_frame_out(port, frame->node_src,
252 frame->sequence_nr))
253 continue;
254
255 if (frame->is_supervision && (port->type == HSR_PT_MASTER)) {
256 hsr_handle_sup_frame(frame->skb_hsr,
257 frame->node_src,
258 frame->port_rcv);
259 continue;
260 }
261
262 if (port->type != HSR_PT_MASTER)
263 skb = frame_get_tagged_skb(frame, port);
264 else
265 skb = frame_get_stripped_skb(frame, port);
266 if (skb == NULL) {
267 /* FIXME: Record the dropped frame? */
268 continue;
269 }
270
271 skb->dev = port->dev;
272 if (port->type == HSR_PT_MASTER)
273 hsr_deliver_master(skb, port->dev, frame->node_src);
274 else
275 hsr_xmit(skb, port, frame);
276 }
277}
278
279
280static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb,
281 struct hsr_frame_info *frame)
282{
283 struct net_device *master_dev;
284
285 master_dev = hsr_port_get_hsr(hsr, HSR_PT_MASTER)->dev;
286
287 if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) {
288 frame->is_local_exclusive = true;
289 skb->pkt_type = PACKET_HOST;
290 } else {
291 frame->is_local_exclusive = false;
292 }
293
294 if ((skb->pkt_type == PACKET_HOST) ||
295 (skb->pkt_type == PACKET_MULTICAST) ||
296 (skb->pkt_type == PACKET_BROADCAST)) {
297 frame->is_local_dest = true;
298 } else {
299 frame->is_local_dest = false;
300 }
301}
302
303
304static int hsr_fill_frame_info(struct hsr_frame_info *frame,
305 struct sk_buff *skb, struct hsr_port *port)
306{
307 struct ethhdr *ethhdr;
308 unsigned long irqflags;
309
310 frame->is_supervision = is_supervision_frame(port->hsr, skb);
311 frame->node_src = hsr_get_node(&port->hsr->node_db, skb,
312 frame->is_supervision);
313 if (frame->node_src == NULL)
314 return -1; /* Unknown node and !is_supervision, or no mem */
315
316 ethhdr = (struct ethhdr *) skb_mac_header(skb);
317 frame->is_vlan = false;
318 if (ethhdr->h_proto == htons(ETH_P_8021Q)) {
319 frame->is_vlan = true;
320 /* FIXME: */
321 WARN_ONCE(1, "HSR: VLAN not yet supported");
322 }
323 if (ethhdr->h_proto == htons(ETH_P_PRP)) {
324 frame->skb_std = NULL;
325 frame->skb_hsr = skb;
326 frame->sequence_nr = hsr_get_skb_sequence_nr(skb);
327 } else {
328 frame->skb_std = skb;
329 frame->skb_hsr = NULL;
330 /* Sequence nr for the master node */
331 spin_lock_irqsave(&port->hsr->seqnr_lock, irqflags);
332 frame->sequence_nr = port->hsr->sequence_nr;
333 port->hsr->sequence_nr++;
334 spin_unlock_irqrestore(&port->hsr->seqnr_lock, irqflags);
335 }
336
337 frame->port_rcv = port;
338 check_local_dest(port->hsr, skb, frame);
339
340 return 0;
341}
342
343/* Must be called holding rcu read lock (because of the port parameter) */
344void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port)
345{
346 struct hsr_frame_info frame;
347
348 if (skb_mac_header(skb) != skb->data) {
349 WARN_ONCE(1, "%s:%d: Malformed frame (port_src %s)\n",
350 __FILE__, __LINE__, port->dev->name);
351 goto out_drop;
352 }
353
354 if (hsr_fill_frame_info(&frame, skb, port) < 0)
355 goto out_drop;
356 hsr_register_frame_in(frame.node_src, port, frame.sequence_nr);
357 hsr_forward_do(&frame);
358
359 if (frame.skb_hsr != NULL)
360 kfree_skb(frame.skb_hsr);
361 if (frame.skb_std != NULL)
362 kfree_skb(frame.skb_std);
363 return;
364
365out_drop:
366 port->dev->stats.tx_dropped++;
367 kfree_skb(skb);
368}