Linux 5.7.7
[linux/fpc-iii.git] / net / batman-adv / tvlv.c
blob0963a43ad996fbbf9455b028fb1afdae4905c82d
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2007-2020 B.A.T.M.A.N. contributors:
4 * Marek Lindner, Simon Wunderlich
5 */
7 #include "main.h"
9 #include <linux/byteorder/generic.h>
10 #include <linux/etherdevice.h>
11 #include <linux/gfp.h>
12 #include <linux/if_ether.h>
13 #include <linux/kernel.h>
14 #include <linux/kref.h>
15 #include <linux/list.h>
16 #include <linux/lockdep.h>
17 #include <linux/netdevice.h>
18 #include <linux/pkt_sched.h>
19 #include <linux/rculist.h>
20 #include <linux/rcupdate.h>
21 #include <linux/skbuff.h>
22 #include <linux/slab.h>
23 #include <linux/spinlock.h>
24 #include <linux/stddef.h>
25 #include <linux/string.h>
26 #include <linux/types.h>
27 #include <uapi/linux/batadv_packet.h>
29 #include "originator.h"
30 #include "send.h"
31 #include "tvlv.h"
33 /**
34 * batadv_tvlv_handler_release() - release tvlv handler from lists and queue for
35 * free after rcu grace period
36 * @ref: kref pointer of the tvlv
38 static void batadv_tvlv_handler_release(struct kref *ref)
40 struct batadv_tvlv_handler *tvlv_handler;
42 tvlv_handler = container_of(ref, struct batadv_tvlv_handler, refcount);
43 kfree_rcu(tvlv_handler, rcu);
46 /**
47 * batadv_tvlv_handler_put() - decrement the tvlv container refcounter and
48 * possibly release it
49 * @tvlv_handler: the tvlv handler to free
51 static void batadv_tvlv_handler_put(struct batadv_tvlv_handler *tvlv_handler)
53 kref_put(&tvlv_handler->refcount, batadv_tvlv_handler_release);
56 /**
57 * batadv_tvlv_handler_get() - retrieve tvlv handler from the tvlv handler list
58 * based on the provided type and version (both need to match)
59 * @bat_priv: the bat priv with all the soft interface information
60 * @type: tvlv handler type to look for
61 * @version: tvlv handler version to look for
63 * Return: tvlv handler if found or NULL otherwise.
65 static struct batadv_tvlv_handler *
66 batadv_tvlv_handler_get(struct batadv_priv *bat_priv, u8 type, u8 version)
68 struct batadv_tvlv_handler *tvlv_handler_tmp, *tvlv_handler = NULL;
70 rcu_read_lock();
71 hlist_for_each_entry_rcu(tvlv_handler_tmp,
72 &bat_priv->tvlv.handler_list, list) {
73 if (tvlv_handler_tmp->type != type)
74 continue;
76 if (tvlv_handler_tmp->version != version)
77 continue;
79 if (!kref_get_unless_zero(&tvlv_handler_tmp->refcount))
80 continue;
82 tvlv_handler = tvlv_handler_tmp;
83 break;
85 rcu_read_unlock();
87 return tvlv_handler;
90 /**
91 * batadv_tvlv_container_release() - release tvlv from lists and free
92 * @ref: kref pointer of the tvlv
94 static void batadv_tvlv_container_release(struct kref *ref)
96 struct batadv_tvlv_container *tvlv;
98 tvlv = container_of(ref, struct batadv_tvlv_container, refcount);
99 kfree(tvlv);
103 * batadv_tvlv_container_put() - decrement the tvlv container refcounter and
104 * possibly release it
105 * @tvlv: the tvlv container to free
107 static void batadv_tvlv_container_put(struct batadv_tvlv_container *tvlv)
109 kref_put(&tvlv->refcount, batadv_tvlv_container_release);
113 * batadv_tvlv_container_get() - retrieve tvlv container from the tvlv container
114 * list based on the provided type and version (both need to match)
115 * @bat_priv: the bat priv with all the soft interface information
116 * @type: tvlv container type to look for
117 * @version: tvlv container version to look for
119 * Has to be called with the appropriate locks being acquired
120 * (tvlv.container_list_lock).
122 * Return: tvlv container if found or NULL otherwise.
124 static struct batadv_tvlv_container *
125 batadv_tvlv_container_get(struct batadv_priv *bat_priv, u8 type, u8 version)
127 struct batadv_tvlv_container *tvlv_tmp, *tvlv = NULL;
129 lockdep_assert_held(&bat_priv->tvlv.container_list_lock);
131 hlist_for_each_entry(tvlv_tmp, &bat_priv->tvlv.container_list, list) {
132 if (tvlv_tmp->tvlv_hdr.type != type)
133 continue;
135 if (tvlv_tmp->tvlv_hdr.version != version)
136 continue;
138 kref_get(&tvlv_tmp->refcount);
139 tvlv = tvlv_tmp;
140 break;
143 return tvlv;
147 * batadv_tvlv_container_list_size() - calculate the size of the tvlv container
148 * list entries
149 * @bat_priv: the bat priv with all the soft interface information
151 * Has to be called with the appropriate locks being acquired
152 * (tvlv.container_list_lock).
154 * Return: size of all currently registered tvlv containers in bytes.
156 static u16 batadv_tvlv_container_list_size(struct batadv_priv *bat_priv)
158 struct batadv_tvlv_container *tvlv;
159 u16 tvlv_len = 0;
161 lockdep_assert_held(&bat_priv->tvlv.container_list_lock);
163 hlist_for_each_entry(tvlv, &bat_priv->tvlv.container_list, list) {
164 tvlv_len += sizeof(struct batadv_tvlv_hdr);
165 tvlv_len += ntohs(tvlv->tvlv_hdr.len);
168 return tvlv_len;
172 * batadv_tvlv_container_remove() - remove tvlv container from the tvlv
173 * container list
174 * @bat_priv: the bat priv with all the soft interface information
175 * @tvlv: the to be removed tvlv container
177 * Has to be called with the appropriate locks being acquired
178 * (tvlv.container_list_lock).
180 static void batadv_tvlv_container_remove(struct batadv_priv *bat_priv,
181 struct batadv_tvlv_container *tvlv)
183 lockdep_assert_held(&bat_priv->tvlv.container_list_lock);
185 if (!tvlv)
186 return;
188 hlist_del(&tvlv->list);
190 /* first call to decrement the counter, second call to free */
191 batadv_tvlv_container_put(tvlv);
192 batadv_tvlv_container_put(tvlv);
196 * batadv_tvlv_container_unregister() - unregister tvlv container based on the
197 * provided type and version (both need to match)
198 * @bat_priv: the bat priv with all the soft interface information
199 * @type: tvlv container type to unregister
200 * @version: tvlv container type to unregister
202 void batadv_tvlv_container_unregister(struct batadv_priv *bat_priv,
203 u8 type, u8 version)
205 struct batadv_tvlv_container *tvlv;
207 spin_lock_bh(&bat_priv->tvlv.container_list_lock);
208 tvlv = batadv_tvlv_container_get(bat_priv, type, version);
209 batadv_tvlv_container_remove(bat_priv, tvlv);
210 spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
214 * batadv_tvlv_container_register() - register tvlv type, version and content
215 * to be propagated with each (primary interface) OGM
216 * @bat_priv: the bat priv with all the soft interface information
217 * @type: tvlv container type
218 * @version: tvlv container version
219 * @tvlv_value: tvlv container content
220 * @tvlv_value_len: tvlv container content length
222 * If a container of the same type and version was already registered the new
223 * content is going to replace the old one.
225 void batadv_tvlv_container_register(struct batadv_priv *bat_priv,
226 u8 type, u8 version,
227 void *tvlv_value, u16 tvlv_value_len)
229 struct batadv_tvlv_container *tvlv_old, *tvlv_new;
231 if (!tvlv_value)
232 tvlv_value_len = 0;
234 tvlv_new = kzalloc(sizeof(*tvlv_new) + tvlv_value_len, GFP_ATOMIC);
235 if (!tvlv_new)
236 return;
238 tvlv_new->tvlv_hdr.version = version;
239 tvlv_new->tvlv_hdr.type = type;
240 tvlv_new->tvlv_hdr.len = htons(tvlv_value_len);
242 memcpy(tvlv_new + 1, tvlv_value, ntohs(tvlv_new->tvlv_hdr.len));
243 INIT_HLIST_NODE(&tvlv_new->list);
244 kref_init(&tvlv_new->refcount);
246 spin_lock_bh(&bat_priv->tvlv.container_list_lock);
247 tvlv_old = batadv_tvlv_container_get(bat_priv, type, version);
248 batadv_tvlv_container_remove(bat_priv, tvlv_old);
250 kref_get(&tvlv_new->refcount);
251 hlist_add_head(&tvlv_new->list, &bat_priv->tvlv.container_list);
252 spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
254 /* don't return reference to new tvlv_container */
255 batadv_tvlv_container_put(tvlv_new);
259 * batadv_tvlv_realloc_packet_buff() - reallocate packet buffer to accommodate
260 * requested packet size
261 * @packet_buff: packet buffer
262 * @packet_buff_len: packet buffer size
263 * @min_packet_len: requested packet minimum size
264 * @additional_packet_len: requested additional packet size on top of minimum
265 * size
267 * Return: true of the packet buffer could be changed to the requested size,
268 * false otherwise.
270 static bool batadv_tvlv_realloc_packet_buff(unsigned char **packet_buff,
271 int *packet_buff_len,
272 int min_packet_len,
273 int additional_packet_len)
275 unsigned char *new_buff;
277 new_buff = kmalloc(min_packet_len + additional_packet_len, GFP_ATOMIC);
279 /* keep old buffer if kmalloc should fail */
280 if (!new_buff)
281 return false;
283 memcpy(new_buff, *packet_buff, min_packet_len);
284 kfree(*packet_buff);
285 *packet_buff = new_buff;
286 *packet_buff_len = min_packet_len + additional_packet_len;
288 return true;
292 * batadv_tvlv_container_ogm_append() - append tvlv container content to given
293 * OGM packet buffer
294 * @bat_priv: the bat priv with all the soft interface information
295 * @packet_buff: ogm packet buffer
296 * @packet_buff_len: ogm packet buffer size including ogm header and tvlv
297 * content
298 * @packet_min_len: ogm header size to be preserved for the OGM itself
300 * The ogm packet might be enlarged or shrunk depending on the current size
301 * and the size of the to-be-appended tvlv containers.
303 * Return: size of all appended tvlv containers in bytes.
305 u16 batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv,
306 unsigned char **packet_buff,
307 int *packet_buff_len, int packet_min_len)
309 struct batadv_tvlv_container *tvlv;
310 struct batadv_tvlv_hdr *tvlv_hdr;
311 u16 tvlv_value_len;
312 void *tvlv_value;
313 bool ret;
315 spin_lock_bh(&bat_priv->tvlv.container_list_lock);
316 tvlv_value_len = batadv_tvlv_container_list_size(bat_priv);
318 ret = batadv_tvlv_realloc_packet_buff(packet_buff, packet_buff_len,
319 packet_min_len, tvlv_value_len);
321 if (!ret)
322 goto end;
324 if (!tvlv_value_len)
325 goto end;
327 tvlv_value = (*packet_buff) + packet_min_len;
329 hlist_for_each_entry(tvlv, &bat_priv->tvlv.container_list, list) {
330 tvlv_hdr = tvlv_value;
331 tvlv_hdr->type = tvlv->tvlv_hdr.type;
332 tvlv_hdr->version = tvlv->tvlv_hdr.version;
333 tvlv_hdr->len = tvlv->tvlv_hdr.len;
334 tvlv_value = tvlv_hdr + 1;
335 memcpy(tvlv_value, tvlv + 1, ntohs(tvlv->tvlv_hdr.len));
336 tvlv_value = (u8 *)tvlv_value + ntohs(tvlv->tvlv_hdr.len);
339 end:
340 spin_unlock_bh(&bat_priv->tvlv.container_list_lock);
341 return tvlv_value_len;
345 * batadv_tvlv_call_handler() - parse the given tvlv buffer to call the
346 * appropriate handlers
347 * @bat_priv: the bat priv with all the soft interface information
348 * @tvlv_handler: tvlv callback function handling the tvlv content
349 * @ogm_source: flag indicating whether the tvlv is an ogm or a unicast packet
350 * @orig_node: orig node emitting the ogm packet
351 * @src: source mac address of the unicast packet
352 * @dst: destination mac address of the unicast packet
353 * @tvlv_value: tvlv content
354 * @tvlv_value_len: tvlv content length
356 * Return: success if handler was not found or the return value of the handler
357 * callback.
359 static int batadv_tvlv_call_handler(struct batadv_priv *bat_priv,
360 struct batadv_tvlv_handler *tvlv_handler,
361 bool ogm_source,
362 struct batadv_orig_node *orig_node,
363 u8 *src, u8 *dst,
364 void *tvlv_value, u16 tvlv_value_len)
366 if (!tvlv_handler)
367 return NET_RX_SUCCESS;
369 if (ogm_source) {
370 if (!tvlv_handler->ogm_handler)
371 return NET_RX_SUCCESS;
373 if (!orig_node)
374 return NET_RX_SUCCESS;
376 tvlv_handler->ogm_handler(bat_priv, orig_node,
377 BATADV_NO_FLAGS,
378 tvlv_value, tvlv_value_len);
379 tvlv_handler->flags |= BATADV_TVLV_HANDLER_OGM_CALLED;
380 } else {
381 if (!src)
382 return NET_RX_SUCCESS;
384 if (!dst)
385 return NET_RX_SUCCESS;
387 if (!tvlv_handler->unicast_handler)
388 return NET_RX_SUCCESS;
390 return tvlv_handler->unicast_handler(bat_priv, src,
391 dst, tvlv_value,
392 tvlv_value_len);
395 return NET_RX_SUCCESS;
399 * batadv_tvlv_containers_process() - parse the given tvlv buffer to call the
400 * appropriate handlers
401 * @bat_priv: the bat priv with all the soft interface information
402 * @ogm_source: flag indicating whether the tvlv is an ogm or a unicast packet
403 * @orig_node: orig node emitting the ogm packet
404 * @src: source mac address of the unicast packet
405 * @dst: destination mac address of the unicast packet
406 * @tvlv_value: tvlv content
407 * @tvlv_value_len: tvlv content length
409 * Return: success when processing an OGM or the return value of all called
410 * handler callbacks.
412 int batadv_tvlv_containers_process(struct batadv_priv *bat_priv,
413 bool ogm_source,
414 struct batadv_orig_node *orig_node,
415 u8 *src, u8 *dst,
416 void *tvlv_value, u16 tvlv_value_len)
418 struct batadv_tvlv_handler *tvlv_handler;
419 struct batadv_tvlv_hdr *tvlv_hdr;
420 u16 tvlv_value_cont_len;
421 u8 cifnotfound = BATADV_TVLV_HANDLER_OGM_CIFNOTFND;
422 int ret = NET_RX_SUCCESS;
424 while (tvlv_value_len >= sizeof(*tvlv_hdr)) {
425 tvlv_hdr = tvlv_value;
426 tvlv_value_cont_len = ntohs(tvlv_hdr->len);
427 tvlv_value = tvlv_hdr + 1;
428 tvlv_value_len -= sizeof(*tvlv_hdr);
430 if (tvlv_value_cont_len > tvlv_value_len)
431 break;
433 tvlv_handler = batadv_tvlv_handler_get(bat_priv,
434 tvlv_hdr->type,
435 tvlv_hdr->version);
437 ret |= batadv_tvlv_call_handler(bat_priv, tvlv_handler,
438 ogm_source, orig_node,
439 src, dst, tvlv_value,
440 tvlv_value_cont_len);
441 if (tvlv_handler)
442 batadv_tvlv_handler_put(tvlv_handler);
443 tvlv_value = (u8 *)tvlv_value + tvlv_value_cont_len;
444 tvlv_value_len -= tvlv_value_cont_len;
447 if (!ogm_source)
448 return ret;
450 rcu_read_lock();
451 hlist_for_each_entry_rcu(tvlv_handler,
452 &bat_priv->tvlv.handler_list, list) {
453 if ((tvlv_handler->flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) &&
454 !(tvlv_handler->flags & BATADV_TVLV_HANDLER_OGM_CALLED))
455 tvlv_handler->ogm_handler(bat_priv, orig_node,
456 cifnotfound, NULL, 0);
458 tvlv_handler->flags &= ~BATADV_TVLV_HANDLER_OGM_CALLED;
460 rcu_read_unlock();
462 return NET_RX_SUCCESS;
466 * batadv_tvlv_ogm_receive() - process an incoming ogm and call the appropriate
467 * handlers
468 * @bat_priv: the bat priv with all the soft interface information
469 * @batadv_ogm_packet: ogm packet containing the tvlv containers
470 * @orig_node: orig node emitting the ogm packet
472 void batadv_tvlv_ogm_receive(struct batadv_priv *bat_priv,
473 struct batadv_ogm_packet *batadv_ogm_packet,
474 struct batadv_orig_node *orig_node)
476 void *tvlv_value;
477 u16 tvlv_value_len;
479 if (!batadv_ogm_packet)
480 return;
482 tvlv_value_len = ntohs(batadv_ogm_packet->tvlv_len);
483 if (!tvlv_value_len)
484 return;
486 tvlv_value = batadv_ogm_packet + 1;
488 batadv_tvlv_containers_process(bat_priv, true, orig_node, NULL, NULL,
489 tvlv_value, tvlv_value_len);
493 * batadv_tvlv_handler_register() - register tvlv handler based on the provided
494 * type and version (both need to match) for ogm tvlv payload and/or unicast
495 * payload
496 * @bat_priv: the bat priv with all the soft interface information
497 * @optr: ogm tvlv handler callback function. This function receives the orig
498 * node, flags and the tvlv content as argument to process.
499 * @uptr: unicast tvlv handler callback function. This function receives the
500 * source & destination of the unicast packet as well as the tvlv content
501 * to process.
502 * @type: tvlv handler type to be registered
503 * @version: tvlv handler version to be registered
504 * @flags: flags to enable or disable TVLV API behavior
506 void batadv_tvlv_handler_register(struct batadv_priv *bat_priv,
507 void (*optr)(struct batadv_priv *bat_priv,
508 struct batadv_orig_node *orig,
509 u8 flags,
510 void *tvlv_value,
511 u16 tvlv_value_len),
512 int (*uptr)(struct batadv_priv *bat_priv,
513 u8 *src, u8 *dst,
514 void *tvlv_value,
515 u16 tvlv_value_len),
516 u8 type, u8 version, u8 flags)
518 struct batadv_tvlv_handler *tvlv_handler;
520 spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
522 tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
523 if (tvlv_handler) {
524 spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
525 batadv_tvlv_handler_put(tvlv_handler);
526 return;
529 tvlv_handler = kzalloc(sizeof(*tvlv_handler), GFP_ATOMIC);
530 if (!tvlv_handler) {
531 spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
532 return;
535 tvlv_handler->ogm_handler = optr;
536 tvlv_handler->unicast_handler = uptr;
537 tvlv_handler->type = type;
538 tvlv_handler->version = version;
539 tvlv_handler->flags = flags;
540 kref_init(&tvlv_handler->refcount);
541 INIT_HLIST_NODE(&tvlv_handler->list);
543 kref_get(&tvlv_handler->refcount);
544 hlist_add_head_rcu(&tvlv_handler->list, &bat_priv->tvlv.handler_list);
545 spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
547 /* don't return reference to new tvlv_handler */
548 batadv_tvlv_handler_put(tvlv_handler);
552 * batadv_tvlv_handler_unregister() - unregister tvlv handler based on the
553 * provided type and version (both need to match)
554 * @bat_priv: the bat priv with all the soft interface information
555 * @type: tvlv handler type to be unregistered
556 * @version: tvlv handler version to be unregistered
558 void batadv_tvlv_handler_unregister(struct batadv_priv *bat_priv,
559 u8 type, u8 version)
561 struct batadv_tvlv_handler *tvlv_handler;
563 tvlv_handler = batadv_tvlv_handler_get(bat_priv, type, version);
564 if (!tvlv_handler)
565 return;
567 batadv_tvlv_handler_put(tvlv_handler);
568 spin_lock_bh(&bat_priv->tvlv.handler_list_lock);
569 hlist_del_rcu(&tvlv_handler->list);
570 spin_unlock_bh(&bat_priv->tvlv.handler_list_lock);
571 batadv_tvlv_handler_put(tvlv_handler);
575 * batadv_tvlv_unicast_send() - send a unicast packet with tvlv payload to the
576 * specified host
577 * @bat_priv: the bat priv with all the soft interface information
578 * @src: source mac address of the unicast packet
579 * @dst: destination mac address of the unicast packet
580 * @type: tvlv type
581 * @version: tvlv version
582 * @tvlv_value: tvlv content
583 * @tvlv_value_len: tvlv content length
585 void batadv_tvlv_unicast_send(struct batadv_priv *bat_priv, u8 *src,
586 u8 *dst, u8 type, u8 version,
587 void *tvlv_value, u16 tvlv_value_len)
589 struct batadv_unicast_tvlv_packet *unicast_tvlv_packet;
590 struct batadv_tvlv_hdr *tvlv_hdr;
591 struct batadv_orig_node *orig_node;
592 struct sk_buff *skb;
593 unsigned char *tvlv_buff;
594 unsigned int tvlv_len;
595 ssize_t hdr_len = sizeof(*unicast_tvlv_packet);
597 orig_node = batadv_orig_hash_find(bat_priv, dst);
598 if (!orig_node)
599 return;
601 tvlv_len = sizeof(*tvlv_hdr) + tvlv_value_len;
603 skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + hdr_len + tvlv_len);
604 if (!skb)
605 goto out;
607 skb->priority = TC_PRIO_CONTROL;
608 skb_reserve(skb, ETH_HLEN);
609 tvlv_buff = skb_put(skb, sizeof(*unicast_tvlv_packet) + tvlv_len);
610 unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)tvlv_buff;
611 unicast_tvlv_packet->packet_type = BATADV_UNICAST_TVLV;
612 unicast_tvlv_packet->version = BATADV_COMPAT_VERSION;
613 unicast_tvlv_packet->ttl = BATADV_TTL;
614 unicast_tvlv_packet->reserved = 0;
615 unicast_tvlv_packet->tvlv_len = htons(tvlv_len);
616 unicast_tvlv_packet->align = 0;
617 ether_addr_copy(unicast_tvlv_packet->src, src);
618 ether_addr_copy(unicast_tvlv_packet->dst, dst);
620 tvlv_buff = (unsigned char *)(unicast_tvlv_packet + 1);
621 tvlv_hdr = (struct batadv_tvlv_hdr *)tvlv_buff;
622 tvlv_hdr->version = version;
623 tvlv_hdr->type = type;
624 tvlv_hdr->len = htons(tvlv_value_len);
625 tvlv_buff += sizeof(*tvlv_hdr);
626 memcpy(tvlv_buff, tvlv_value, tvlv_value_len);
628 batadv_send_skb_to_orig(skb, orig_node, NULL);
629 out:
630 batadv_orig_node_put(orig_node);