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f266a683 AB |
1 | /* 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 | ||
21 | struct hsr_node; | |
22 | ||
23 | struct 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 | */ | |
51 | static 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 | ||
74 | static 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 | ||
103 | static 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 | ||
112 | static 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 | ||
137 | static 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 | */ | |
171 | static 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 | ||
186 | static 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 | ||
206 | static 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 | */ | |
232 | static 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 | ||
280 | static 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 | ||
304 | static 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) */ | |
344 | void 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 | ||
365 | out_drop: | |
366 | port->dev->stats.tx_dropped++; | |
367 | kfree_skb(skb); | |
368 | } |