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70ebe4a4 | 1 | /* Copyright 2011-2014 Autronica Fire and Security AS |
f421436a AB |
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): | |
70ebe4a4 | 9 | * 2011-2014 Arvid Brodin, arvid.brodin@alten.se |
f421436a AB |
10 | * |
11 | * The HSR spec says never to forward the same frame twice on the same | |
12 | * interface. A frame is identified by its source MAC address and its HSR | |
13 | * sequence number. This code keeps track of senders and their sequence numbers | |
14 | * to allow filtering of duplicate frames, and to detect HSR ring errors. | |
15 | */ | |
16 | ||
17 | #include <linux/if_ether.h> | |
18 | #include <linux/etherdevice.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/rculist.h> | |
21 | #include "hsr_main.h" | |
22 | #include "hsr_framereg.h" | |
23 | #include "hsr_netlink.h" | |
24 | ||
25 | ||
70ebe4a4 AB |
26 | struct hsr_node { |
27 | struct list_head mac_list; | |
28 | unsigned char MacAddressA[ETH_ALEN]; | |
29 | unsigned char MacAddressB[ETH_ALEN]; | |
c5a75911 AB |
30 | /* Local slave through which AddrB frames are received from this node */ |
31 | enum hsr_port_type AddrB_port; | |
32 | unsigned long time_in[HSR_PT_PORTS]; | |
33 | bool time_in_stale[HSR_PT_PORTS]; | |
34 | u16 seq_out[HSR_PT_PORTS]; | |
70ebe4a4 | 35 | struct rcu_head rcu_head; |
f421436a AB |
36 | }; |
37 | ||
f421436a | 38 | |
f266a683 | 39 | /* TODO: use hash lists for mac addresses (linux/jhash.h)? */ |
f421436a AB |
40 | |
41 | ||
f266a683 AB |
42 | /* seq_nr_after(a, b) - return true if a is after (higher in sequence than) b, |
43 | * false otherwise. | |
f421436a | 44 | */ |
f266a683 | 45 | static bool seq_nr_after(u16 a, u16 b) |
f421436a | 46 | { |
f266a683 AB |
47 | /* Remove inconsistency where |
48 | * seq_nr_after(a, b) == seq_nr_before(a, b) | |
49 | */ | |
50 | if ((int) b - a == 32768) | |
51 | return false; | |
f421436a | 52 | |
f266a683 | 53 | return (((s16) (b - a)) < 0); |
f421436a | 54 | } |
f266a683 AB |
55 | #define seq_nr_before(a, b) seq_nr_after((b), (a)) |
56 | #define seq_nr_after_or_eq(a, b) (!seq_nr_before((a), (b))) | |
57 | #define seq_nr_before_or_eq(a, b) (!seq_nr_after((a), (b))) | |
f421436a AB |
58 | |
59 | ||
f266a683 | 60 | bool hsr_addr_is_self(struct hsr_priv *hsr, unsigned char *addr) |
f421436a | 61 | { |
70ebe4a4 | 62 | struct hsr_node *node; |
f421436a | 63 | |
f266a683 AB |
64 | node = list_first_or_null_rcu(&hsr->self_node_db, struct hsr_node, |
65 | mac_list); | |
66 | if (!node) { | |
67 | WARN_ONCE(1, "HSR: No self node\n"); | |
68 | return false; | |
f421436a AB |
69 | } |
70 | ||
f266a683 AB |
71 | if (ether_addr_equal(addr, node->MacAddressA)) |
72 | return true; | |
73 | if (ether_addr_equal(addr, node->MacAddressB)) | |
74 | return true; | |
f421436a | 75 | |
f266a683 AB |
76 | return false; |
77 | } | |
f421436a AB |
78 | |
79 | /* Search for mac entry. Caller must hold rcu read lock. | |
80 | */ | |
f266a683 AB |
81 | static struct hsr_node *find_node_by_AddrA(struct list_head *node_db, |
82 | const unsigned char addr[ETH_ALEN]) | |
f421436a | 83 | { |
70ebe4a4 | 84 | struct hsr_node *node; |
f421436a AB |
85 | |
86 | list_for_each_entry_rcu(node, node_db, mac_list) { | |
f266a683 | 87 | if (ether_addr_equal(node->MacAddressA, addr)) |
f421436a AB |
88 | return node; |
89 | } | |
90 | ||
91 | return NULL; | |
92 | } | |
93 | ||
94 | ||
95 | /* Helper for device init; the self_node_db is used in hsr_rcv() to recognize | |
96 | * frames from self that's been looped over the HSR ring. | |
97 | */ | |
98 | int hsr_create_self_node(struct list_head *self_node_db, | |
99 | unsigned char addr_a[ETH_ALEN], | |
100 | unsigned char addr_b[ETH_ALEN]) | |
101 | { | |
70ebe4a4 | 102 | struct hsr_node *node, *oldnode; |
f421436a AB |
103 | |
104 | node = kmalloc(sizeof(*node), GFP_KERNEL); | |
105 | if (!node) | |
106 | return -ENOMEM; | |
107 | ||
e83abe37 JP |
108 | ether_addr_copy(node->MacAddressA, addr_a); |
109 | ether_addr_copy(node->MacAddressB, addr_b); | |
f421436a AB |
110 | |
111 | rcu_read_lock(); | |
112 | oldnode = list_first_or_null_rcu(self_node_db, | |
70ebe4a4 | 113 | struct hsr_node, mac_list); |
f421436a AB |
114 | if (oldnode) { |
115 | list_replace_rcu(&oldnode->mac_list, &node->mac_list); | |
116 | rcu_read_unlock(); | |
117 | synchronize_rcu(); | |
118 | kfree(oldnode); | |
119 | } else { | |
120 | rcu_read_unlock(); | |
121 | list_add_tail_rcu(&node->mac_list, self_node_db); | |
122 | } | |
123 | ||
124 | return 0; | |
125 | } | |
126 | ||
f421436a | 127 | |
f266a683 AB |
128 | /* Allocate an hsr_node and add it to node_db. 'addr' is the node's AddressA; |
129 | * seq_out is used to initialize filtering of outgoing duplicate frames | |
130 | * originating from the newly added node. | |
f421436a | 131 | */ |
f266a683 AB |
132 | struct hsr_node *hsr_add_node(struct list_head *node_db, unsigned char addr[], |
133 | u16 seq_out) | |
f421436a | 134 | { |
f266a683 | 135 | struct hsr_node *node; |
f421436a | 136 | unsigned long now; |
f266a683 | 137 | int i; |
f421436a AB |
138 | |
139 | node = kzalloc(sizeof(*node), GFP_ATOMIC); | |
140 | if (!node) | |
141 | return NULL; | |
142 | ||
f266a683 | 143 | ether_addr_copy(node->MacAddressA, addr); |
f421436a AB |
144 | |
145 | /* We are only interested in time diffs here, so use current jiffies | |
146 | * as initialization. (0 could trigger an spurious ring error warning). | |
147 | */ | |
148 | now = jiffies; | |
c5a75911 | 149 | for (i = 0; i < HSR_PT_PORTS; i++) |
f421436a | 150 | node->time_in[i] = now; |
c5a75911 | 151 | for (i = 0; i < HSR_PT_PORTS; i++) |
f266a683 | 152 | node->seq_out[i] = seq_out; |
f421436a | 153 | |
f266a683 | 154 | list_add_tail_rcu(&node->mac_list, node_db); |
f421436a AB |
155 | |
156 | return node; | |
157 | } | |
158 | ||
f266a683 AB |
159 | /* Get the hsr_node from which 'skb' was sent. |
160 | */ | |
161 | struct hsr_node *hsr_get_node(struct list_head *node_db, struct sk_buff *skb, | |
162 | bool is_sup) | |
163 | { | |
164 | struct hsr_node *node; | |
165 | struct ethhdr *ethhdr; | |
166 | u16 seq_out; | |
167 | ||
168 | if (!skb_mac_header_was_set(skb)) | |
169 | return NULL; | |
170 | ||
171 | ethhdr = (struct ethhdr *) skb_mac_header(skb); | |
172 | ||
173 | list_for_each_entry_rcu(node, node_db, mac_list) { | |
174 | if (ether_addr_equal(node->MacAddressA, ethhdr->h_source)) | |
175 | return node; | |
176 | if (ether_addr_equal(node->MacAddressB, ethhdr->h_source)) | |
177 | return node; | |
178 | } | |
179 | ||
180 | if (!is_sup) | |
181 | return NULL; /* Only supervision frame may create node entry */ | |
182 | ||
183 | if (ethhdr->h_proto == htons(ETH_P_PRP)) { | |
184 | /* Use the existing sequence_nr from the tag as starting point | |
185 | * for filtering duplicate frames. | |
186 | */ | |
187 | seq_out = hsr_get_skb_sequence_nr(skb) - 1; | |
188 | } else { | |
189 | WARN_ONCE(1, "%s: Non-HSR frame\n", __func__); | |
190 | seq_out = 0; | |
191 | } | |
192 | ||
193 | return hsr_add_node(node_db, ethhdr->h_source, seq_out); | |
194 | } | |
195 | ||
196 | /* Use the Supervision frame's info about an eventual MacAddressB for merging | |
197 | * nodes that has previously had their MacAddressB registered as a separate | |
198 | * node. | |
199 | */ | |
200 | void hsr_handle_sup_frame(struct sk_buff *skb, struct hsr_node *node_curr, | |
201 | struct hsr_port *port_rcv) | |
202 | { | |
203 | struct hsr_node *node_real; | |
204 | struct hsr_sup_payload *hsr_sp; | |
205 | struct list_head *node_db; | |
206 | int i; | |
207 | ||
208 | skb_pull(skb, sizeof(struct hsr_ethhdr_sp)); | |
209 | hsr_sp = (struct hsr_sup_payload *) skb->data; | |
210 | ||
211 | if (ether_addr_equal(eth_hdr(skb)->h_source, hsr_sp->MacAddressA)) | |
212 | /* Not sent from MacAddressB of a PICS_SUBS capable node */ | |
213 | goto done; | |
214 | ||
215 | /* Merge node_curr (registered on MacAddressB) into node_real */ | |
216 | node_db = &port_rcv->hsr->node_db; | |
217 | node_real = find_node_by_AddrA(node_db, hsr_sp->MacAddressA); | |
218 | if (!node_real) | |
219 | /* No frame received from AddrA of this node yet */ | |
220 | node_real = hsr_add_node(node_db, hsr_sp->MacAddressA, | |
221 | HSR_SEQNR_START - 1); | |
222 | if (!node_real) | |
223 | goto done; /* No mem */ | |
224 | if (node_real == node_curr) | |
225 | /* Node has already been merged */ | |
226 | goto done; | |
227 | ||
228 | ether_addr_copy(node_real->MacAddressB, eth_hdr(skb)->h_source); | |
229 | for (i = 0; i < HSR_PT_PORTS; i++) { | |
230 | if (!node_curr->time_in_stale[i] && | |
231 | time_after(node_curr->time_in[i], node_real->time_in[i])) { | |
232 | node_real->time_in[i] = node_curr->time_in[i]; | |
233 | node_real->time_in_stale[i] = node_curr->time_in_stale[i]; | |
234 | } | |
235 | if (seq_nr_after(node_curr->seq_out[i], node_real->seq_out[i])) | |
236 | node_real->seq_out[i] = node_curr->seq_out[i]; | |
237 | } | |
238 | node_real->AddrB_port = port_rcv->type; | |
239 | ||
240 | list_del_rcu(&node_curr->mac_list); | |
241 | kfree_rcu(node_curr, rcu_head); | |
242 | ||
243 | done: | |
244 | skb_push(skb, sizeof(struct hsr_ethhdr_sp)); | |
245 | } | |
246 | ||
f421436a AB |
247 | |
248 | /* 'skb' is a frame meant for this host, that is to be passed to upper layers. | |
249 | * | |
f266a683 | 250 | * If the frame was sent by a node's B interface, replace the source |
f421436a AB |
251 | * address with that node's "official" address (MacAddressA) so that upper |
252 | * layers recognize where it came from. | |
253 | */ | |
f266a683 | 254 | void hsr_addr_subst_source(struct hsr_node *node, struct sk_buff *skb) |
f421436a | 255 | { |
f421436a AB |
256 | if (!skb_mac_header_was_set(skb)) { |
257 | WARN_ONCE(1, "%s: Mac header not set\n", __func__); | |
258 | return; | |
259 | } | |
f421436a | 260 | |
f266a683 | 261 | memcpy(ð_hdr(skb)->h_source, node->MacAddressA, ETH_ALEN); |
f421436a AB |
262 | } |
263 | ||
f421436a | 264 | /* 'skb' is a frame meant for another host. |
f266a683 | 265 | * 'port' is the outgoing interface |
f421436a AB |
266 | * |
267 | * Substitute the target (dest) MAC address if necessary, so the it matches the | |
268 | * recipient interface MAC address, regardless of whether that is the | |
269 | * recipient's A or B interface. | |
270 | * This is needed to keep the packets flowing through switches that learn on | |
271 | * which "side" the different interfaces are. | |
272 | */ | |
f266a683 | 273 | void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb, |
c5a75911 | 274 | struct hsr_port *port) |
f421436a | 275 | { |
f266a683 | 276 | struct hsr_node *node_dst; |
f421436a | 277 | |
f266a683 AB |
278 | if (!skb_mac_header_was_set(skb)) { |
279 | WARN_ONCE(1, "%s: Mac header not set\n", __func__); | |
280 | return; | |
281 | } | |
f421436a | 282 | |
f266a683 AB |
283 | if (!is_unicast_ether_addr(eth_hdr(skb)->h_dest)) |
284 | return; | |
f421436a | 285 | |
f266a683 AB |
286 | node_dst = find_node_by_AddrA(&port->hsr->node_db, eth_hdr(skb)->h_dest); |
287 | if (!node_dst) { | |
288 | WARN_ONCE(1, "%s: Unknown node\n", __func__); | |
289 | return; | |
290 | } | |
291 | if (port->type != node_dst->AddrB_port) | |
292 | return; | |
f421436a | 293 | |
f266a683 | 294 | ether_addr_copy(eth_hdr(skb)->h_dest, node_dst->MacAddressB); |
f421436a | 295 | } |
f421436a AB |
296 | |
297 | ||
f266a683 AB |
298 | void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port, |
299 | u16 sequence_nr) | |
f421436a | 300 | { |
f266a683 AB |
301 | /* Don't register incoming frames without a valid sequence number. This |
302 | * ensures entries of restarted nodes gets pruned so that they can | |
303 | * re-register and resume communications. | |
304 | */ | |
305 | if (seq_nr_before(sequence_nr, node->seq_out[port->type])) | |
306 | return; | |
307 | ||
c5a75911 AB |
308 | node->time_in[port->type] = jiffies; |
309 | node->time_in_stale[port->type] = false; | |
f421436a AB |
310 | } |
311 | ||
f421436a AB |
312 | /* 'skb' is a HSR Ethernet frame (with a HSR tag inserted), with a valid |
313 | * ethhdr->h_source address and skb->mac_header set. | |
314 | * | |
315 | * Return: | |
316 | * 1 if frame can be shown to have been sent recently on this interface, | |
317 | * 0 otherwise, or | |
318 | * negative error code on error | |
319 | */ | |
f266a683 AB |
320 | int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node, |
321 | u16 sequence_nr) | |
f421436a | 322 | { |
c5a75911 | 323 | if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type])) |
f421436a AB |
324 | return 1; |
325 | ||
c5a75911 | 326 | node->seq_out[port->type] = sequence_nr; |
f421436a AB |
327 | return 0; |
328 | } | |
329 | ||
330 | ||
c5a75911 AB |
331 | static struct hsr_port *get_late_port(struct hsr_priv *hsr, |
332 | struct hsr_node *node) | |
f421436a | 333 | { |
c5a75911 AB |
334 | if (node->time_in_stale[HSR_PT_SLAVE_A]) |
335 | return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A); | |
336 | if (node->time_in_stale[HSR_PT_SLAVE_B]) | |
337 | return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B); | |
338 | ||
339 | if (time_after(node->time_in[HSR_PT_SLAVE_B], | |
340 | node->time_in[HSR_PT_SLAVE_A] + | |
341 | msecs_to_jiffies(MAX_SLAVE_DIFF))) | |
342 | return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A); | |
343 | if (time_after(node->time_in[HSR_PT_SLAVE_A], | |
344 | node->time_in[HSR_PT_SLAVE_B] + | |
345 | msecs_to_jiffies(MAX_SLAVE_DIFF))) | |
346 | return hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B); | |
f421436a | 347 | |
c5a75911 | 348 | return NULL; |
f421436a AB |
349 | } |
350 | ||
351 | ||
352 | /* Remove stale sequence_nr records. Called by timer every | |
353 | * HSR_LIFE_CHECK_INTERVAL (two seconds or so). | |
354 | */ | |
abff7162 | 355 | void hsr_prune_nodes(unsigned long data) |
f421436a | 356 | { |
abff7162 | 357 | struct hsr_priv *hsr; |
70ebe4a4 | 358 | struct hsr_node *node; |
c5a75911 | 359 | struct hsr_port *port; |
f421436a AB |
360 | unsigned long timestamp; |
361 | unsigned long time_a, time_b; | |
362 | ||
abff7162 AB |
363 | hsr = (struct hsr_priv *) data; |
364 | ||
f421436a | 365 | rcu_read_lock(); |
70ebe4a4 | 366 | list_for_each_entry_rcu(node, &hsr->node_db, mac_list) { |
f421436a | 367 | /* Shorthand */ |
c5a75911 AB |
368 | time_a = node->time_in[HSR_PT_SLAVE_A]; |
369 | time_b = node->time_in[HSR_PT_SLAVE_B]; | |
f421436a AB |
370 | |
371 | /* Check for timestamps old enough to risk wrap-around */ | |
372 | if (time_after(jiffies, time_a + MAX_JIFFY_OFFSET/2)) | |
c5a75911 | 373 | node->time_in_stale[HSR_PT_SLAVE_A] = true; |
f421436a | 374 | if (time_after(jiffies, time_b + MAX_JIFFY_OFFSET/2)) |
c5a75911 | 375 | node->time_in_stale[HSR_PT_SLAVE_B] = true; |
f421436a AB |
376 | |
377 | /* Get age of newest frame from node. | |
378 | * At least one time_in is OK here; nodes get pruned long | |
379 | * before both time_ins can get stale | |
380 | */ | |
381 | timestamp = time_a; | |
c5a75911 AB |
382 | if (node->time_in_stale[HSR_PT_SLAVE_A] || |
383 | (!node->time_in_stale[HSR_PT_SLAVE_B] && | |
f421436a AB |
384 | time_after(time_b, time_a))) |
385 | timestamp = time_b; | |
386 | ||
387 | /* Warn of ring error only as long as we get frames at all */ | |
388 | if (time_is_after_jiffies(timestamp + | |
389 | msecs_to_jiffies(1.5*MAX_SLAVE_DIFF))) { | |
c5a75911 AB |
390 | rcu_read_lock(); |
391 | port = get_late_port(hsr, node); | |
392 | if (port != NULL) | |
393 | hsr_nl_ringerror(hsr, node->MacAddressA, port); | |
394 | rcu_read_unlock(); | |
f421436a AB |
395 | } |
396 | ||
397 | /* Prune old entries */ | |
398 | if (time_is_before_jiffies(timestamp + | |
399 | msecs_to_jiffies(HSR_NODE_FORGET_TIME))) { | |
70ebe4a4 | 400 | hsr_nl_nodedown(hsr, node->MacAddressA); |
f421436a AB |
401 | list_del_rcu(&node->mac_list); |
402 | /* Note that we need to free this entry later: */ | |
1aee6cc2 | 403 | kfree_rcu(node, rcu_head); |
f421436a AB |
404 | } |
405 | } | |
406 | rcu_read_unlock(); | |
407 | } | |
408 | ||
409 | ||
70ebe4a4 | 410 | void *hsr_get_next_node(struct hsr_priv *hsr, void *_pos, |
f421436a AB |
411 | unsigned char addr[ETH_ALEN]) |
412 | { | |
70ebe4a4 | 413 | struct hsr_node *node; |
f421436a AB |
414 | |
415 | if (!_pos) { | |
70ebe4a4 AB |
416 | node = list_first_or_null_rcu(&hsr->node_db, |
417 | struct hsr_node, mac_list); | |
f421436a | 418 | if (node) |
e83abe37 | 419 | ether_addr_copy(addr, node->MacAddressA); |
f421436a AB |
420 | return node; |
421 | } | |
422 | ||
423 | node = _pos; | |
70ebe4a4 | 424 | list_for_each_entry_continue_rcu(node, &hsr->node_db, mac_list) { |
e83abe37 | 425 | ether_addr_copy(addr, node->MacAddressA); |
f421436a AB |
426 | return node; |
427 | } | |
428 | ||
429 | return NULL; | |
430 | } | |
431 | ||
432 | ||
70ebe4a4 | 433 | int hsr_get_node_data(struct hsr_priv *hsr, |
f421436a AB |
434 | const unsigned char *addr, |
435 | unsigned char addr_b[ETH_ALEN], | |
436 | unsigned int *addr_b_ifindex, | |
437 | int *if1_age, | |
438 | u16 *if1_seq, | |
439 | int *if2_age, | |
440 | u16 *if2_seq) | |
441 | { | |
70ebe4a4 | 442 | struct hsr_node *node; |
c5a75911 | 443 | struct hsr_port *port; |
f421436a AB |
444 | unsigned long tdiff; |
445 | ||
446 | ||
447 | rcu_read_lock(); | |
70ebe4a4 | 448 | node = find_node_by_AddrA(&hsr->node_db, addr); |
f421436a AB |
449 | if (!node) { |
450 | rcu_read_unlock(); | |
451 | return -ENOENT; /* No such entry */ | |
452 | } | |
453 | ||
e83abe37 | 454 | ether_addr_copy(addr_b, node->MacAddressB); |
f421436a | 455 | |
c5a75911 AB |
456 | tdiff = jiffies - node->time_in[HSR_PT_SLAVE_A]; |
457 | if (node->time_in_stale[HSR_PT_SLAVE_A]) | |
f421436a AB |
458 | *if1_age = INT_MAX; |
459 | #if HZ <= MSEC_PER_SEC | |
460 | else if (tdiff > msecs_to_jiffies(INT_MAX)) | |
461 | *if1_age = INT_MAX; | |
462 | #endif | |
463 | else | |
464 | *if1_age = jiffies_to_msecs(tdiff); | |
465 | ||
c5a75911 AB |
466 | tdiff = jiffies - node->time_in[HSR_PT_SLAVE_B]; |
467 | if (node->time_in_stale[HSR_PT_SLAVE_B]) | |
f421436a AB |
468 | *if2_age = INT_MAX; |
469 | #if HZ <= MSEC_PER_SEC | |
470 | else if (tdiff > msecs_to_jiffies(INT_MAX)) | |
471 | *if2_age = INT_MAX; | |
472 | #endif | |
473 | else | |
474 | *if2_age = jiffies_to_msecs(tdiff); | |
475 | ||
476 | /* Present sequence numbers as if they were incoming on interface */ | |
c5a75911 AB |
477 | *if1_seq = node->seq_out[HSR_PT_SLAVE_B]; |
478 | *if2_seq = node->seq_out[HSR_PT_SLAVE_A]; | |
f421436a | 479 | |
c5a75911 AB |
480 | if (node->AddrB_port != HSR_PT_NONE) { |
481 | port = hsr_port_get_hsr(hsr, node->AddrB_port); | |
482 | *addr_b_ifindex = port->dev->ifindex; | |
483 | } else { | |
f421436a | 484 | *addr_b_ifindex = -1; |
c5a75911 | 485 | } |
f421436a AB |
486 | |
487 | rcu_read_unlock(); | |
488 | ||
489 | return 0; | |
490 | } |