xref: /linux/net/batman-adv/main.c (revision c75c5ab575af7db707689cdbb5a5c458e9a034bb)
1 /* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
2  *
3  * Marek Lindner, Simon Wunderlich
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of version 2 of the GNU General Public
7  * License as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17  * 02110-1301, USA
18  */
19 
20 #include <linux/crc32c.h>
21 #include <linux/highmem.h>
22 #include "main.h"
23 #include "sysfs.h"
24 #include "debugfs.h"
25 #include "routing.h"
26 #include "send.h"
27 #include "originator.h"
28 #include "soft-interface.h"
29 #include "icmp_socket.h"
30 #include "translation-table.h"
31 #include "hard-interface.h"
32 #include "gateway_client.h"
33 #include "bridge_loop_avoidance.h"
34 #include "distributed-arp-table.h"
35 #include "vis.h"
36 #include "hash.h"
37 #include "bat_algo.h"
38 
39 
40 /* List manipulations on hardif_list have to be rtnl_lock()'ed,
41  * list traversals just rcu-locked
42  */
43 struct list_head batadv_hardif_list;
44 static int (*batadv_rx_handler[256])(struct sk_buff *,
45 				     struct batadv_hard_iface *);
46 char batadv_routing_algo[20] = "BATMAN_IV";
47 static struct hlist_head batadv_algo_list;
48 
49 unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
50 
51 struct workqueue_struct *batadv_event_workqueue;
52 
53 static void batadv_recv_handler_init(void);
54 
55 static int __init batadv_init(void)
56 {
57 	INIT_LIST_HEAD(&batadv_hardif_list);
58 	INIT_HLIST_HEAD(&batadv_algo_list);
59 
60 	batadv_recv_handler_init();
61 
62 	batadv_iv_init();
63 
64 	batadv_event_workqueue = create_singlethread_workqueue("bat_events");
65 
66 	if (!batadv_event_workqueue)
67 		return -ENOMEM;
68 
69 	batadv_socket_init();
70 	batadv_debugfs_init();
71 
72 	register_netdevice_notifier(&batadv_hard_if_notifier);
73 
74 	pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
75 		BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
76 
77 	return 0;
78 }
79 
80 static void __exit batadv_exit(void)
81 {
82 	batadv_debugfs_destroy();
83 	unregister_netdevice_notifier(&batadv_hard_if_notifier);
84 	batadv_hardif_remove_interfaces();
85 
86 	flush_workqueue(batadv_event_workqueue);
87 	destroy_workqueue(batadv_event_workqueue);
88 	batadv_event_workqueue = NULL;
89 
90 	rcu_barrier();
91 }
92 
93 int batadv_mesh_init(struct net_device *soft_iface)
94 {
95 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
96 	int ret;
97 
98 	spin_lock_init(&bat_priv->forw_bat_list_lock);
99 	spin_lock_init(&bat_priv->forw_bcast_list_lock);
100 	spin_lock_init(&bat_priv->tt.changes_list_lock);
101 	spin_lock_init(&bat_priv->tt.req_list_lock);
102 	spin_lock_init(&bat_priv->tt.roam_list_lock);
103 	spin_lock_init(&bat_priv->tt.last_changeset_lock);
104 	spin_lock_init(&bat_priv->gw.list_lock);
105 	spin_lock_init(&bat_priv->vis.hash_lock);
106 	spin_lock_init(&bat_priv->vis.list_lock);
107 
108 	INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
109 	INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
110 	INIT_HLIST_HEAD(&bat_priv->gw.list);
111 	INIT_LIST_HEAD(&bat_priv->tt.changes_list);
112 	INIT_LIST_HEAD(&bat_priv->tt.req_list);
113 	INIT_LIST_HEAD(&bat_priv->tt.roam_list);
114 
115 	ret = batadv_originator_init(bat_priv);
116 	if (ret < 0)
117 		goto err;
118 
119 	ret = batadv_tt_init(bat_priv);
120 	if (ret < 0)
121 		goto err;
122 
123 	batadv_tt_local_add(soft_iface, soft_iface->dev_addr,
124 			    BATADV_NULL_IFINDEX);
125 
126 	ret = batadv_vis_init(bat_priv);
127 	if (ret < 0)
128 		goto err;
129 
130 	ret = batadv_bla_init(bat_priv);
131 	if (ret < 0)
132 		goto err;
133 
134 	ret = batadv_dat_init(bat_priv);
135 	if (ret < 0)
136 		goto err;
137 
138 	atomic_set(&bat_priv->gw.reselect, 0);
139 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
140 
141 	return 0;
142 
143 err:
144 	batadv_mesh_free(soft_iface);
145 	return ret;
146 }
147 
148 void batadv_mesh_free(struct net_device *soft_iface)
149 {
150 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
151 
152 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
153 
154 	batadv_purge_outstanding_packets(bat_priv, NULL);
155 
156 	batadv_vis_quit(bat_priv);
157 
158 	batadv_gw_node_purge(bat_priv);
159 	batadv_originator_free(bat_priv);
160 
161 	batadv_tt_free(bat_priv);
162 
163 	batadv_bla_free(bat_priv);
164 
165 	batadv_dat_free(bat_priv);
166 
167 	free_percpu(bat_priv->bat_counters);
168 
169 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
170 }
171 
172 int batadv_is_my_mac(struct batadv_priv *bat_priv, const uint8_t *addr)
173 {
174 	const struct batadv_hard_iface *hard_iface;
175 
176 	rcu_read_lock();
177 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
178 		if (hard_iface->if_status != BATADV_IF_ACTIVE)
179 			continue;
180 
181 		if (hard_iface->soft_iface != bat_priv->soft_iface)
182 			continue;
183 
184 		if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
185 			rcu_read_unlock();
186 			return 1;
187 		}
188 	}
189 	rcu_read_unlock();
190 	return 0;
191 }
192 
193 /**
194  * batadv_seq_print_text_primary_if_get - called from debugfs table printing
195  *  function that requires the primary interface
196  * @seq: debugfs table seq_file struct
197  *
198  * Returns primary interface if found or NULL otherwise.
199  */
200 struct batadv_hard_iface *
201 batadv_seq_print_text_primary_if_get(struct seq_file *seq)
202 {
203 	struct net_device *net_dev = (struct net_device *)seq->private;
204 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
205 	struct batadv_hard_iface *primary_if;
206 
207 	primary_if = batadv_primary_if_get_selected(bat_priv);
208 
209 	if (!primary_if) {
210 		seq_printf(seq,
211 			   "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
212 			   net_dev->name);
213 		goto out;
214 	}
215 
216 	if (primary_if->if_status == BATADV_IF_ACTIVE)
217 		goto out;
218 
219 	seq_printf(seq,
220 		   "BATMAN mesh %s disabled - primary interface not active\n",
221 		   net_dev->name);
222 	batadv_hardif_free_ref(primary_if);
223 	primary_if = NULL;
224 
225 out:
226 	return primary_if;
227 }
228 
229 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
230 					struct batadv_hard_iface *recv_if)
231 {
232 	return NET_RX_DROP;
233 }
234 
235 /* incoming packets with the batman ethertype received on any active hard
236  * interface
237  */
238 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
239 			   struct packet_type *ptype,
240 			   struct net_device *orig_dev)
241 {
242 	struct batadv_priv *bat_priv;
243 	struct batadv_ogm_packet *batadv_ogm_packet;
244 	struct batadv_hard_iface *hard_iface;
245 	uint8_t idx;
246 	int ret;
247 
248 	hard_iface = container_of(ptype, struct batadv_hard_iface,
249 				  batman_adv_ptype);
250 	skb = skb_share_check(skb, GFP_ATOMIC);
251 
252 	/* skb was released by skb_share_check() */
253 	if (!skb)
254 		goto err_out;
255 
256 	/* packet should hold at least type and version */
257 	if (unlikely(!pskb_may_pull(skb, 2)))
258 		goto err_free;
259 
260 	/* expect a valid ethernet header here. */
261 	if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
262 		goto err_free;
263 
264 	if (!hard_iface->soft_iface)
265 		goto err_free;
266 
267 	bat_priv = netdev_priv(hard_iface->soft_iface);
268 
269 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
270 		goto err_free;
271 
272 	/* discard frames on not active interfaces */
273 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
274 		goto err_free;
275 
276 	batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
277 
278 	if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
279 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
280 			   "Drop packet: incompatible batman version (%i)\n",
281 			   batadv_ogm_packet->header.version);
282 		goto err_free;
283 	}
284 
285 	/* all receive handlers return whether they received or reused
286 	 * the supplied skb. if not, we have to free the skb.
287 	 */
288 	idx = batadv_ogm_packet->header.packet_type;
289 	ret = (*batadv_rx_handler[idx])(skb, hard_iface);
290 
291 	if (ret == NET_RX_DROP)
292 		kfree_skb(skb);
293 
294 	/* return NET_RX_SUCCESS in any case as we
295 	 * most probably dropped the packet for
296 	 * routing-logical reasons.
297 	 */
298 	return NET_RX_SUCCESS;
299 
300 err_free:
301 	kfree_skb(skb);
302 err_out:
303 	return NET_RX_DROP;
304 }
305 
306 static void batadv_recv_handler_init(void)
307 {
308 	int i;
309 
310 	for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
311 		batadv_rx_handler[i] = batadv_recv_unhandled_packet;
312 
313 	/* batman icmp packet */
314 	batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
315 	/* unicast with 4 addresses packet */
316 	batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
317 	/* unicast packet */
318 	batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
319 	/* fragmented unicast packet */
320 	batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
321 	/* broadcast packet */
322 	batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
323 	/* vis packet */
324 	batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
325 	/* Translation table query (request or response) */
326 	batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
327 	/* Roaming advertisement */
328 	batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
329 }
330 
331 int
332 batadv_recv_handler_register(uint8_t packet_type,
333 			     int (*recv_handler)(struct sk_buff *,
334 						 struct batadv_hard_iface *))
335 {
336 	if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
337 		return -EBUSY;
338 
339 	batadv_rx_handler[packet_type] = recv_handler;
340 	return 0;
341 }
342 
343 void batadv_recv_handler_unregister(uint8_t packet_type)
344 {
345 	batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
346 }
347 
348 static struct batadv_algo_ops *batadv_algo_get(char *name)
349 {
350 	struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
351 
352 	hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
353 		if (strcmp(bat_algo_ops_tmp->name, name) != 0)
354 			continue;
355 
356 		bat_algo_ops = bat_algo_ops_tmp;
357 		break;
358 	}
359 
360 	return bat_algo_ops;
361 }
362 
363 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
364 {
365 	struct batadv_algo_ops *bat_algo_ops_tmp;
366 	int ret;
367 
368 	bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
369 	if (bat_algo_ops_tmp) {
370 		pr_info("Trying to register already registered routing algorithm: %s\n",
371 			bat_algo_ops->name);
372 		ret = -EEXIST;
373 		goto out;
374 	}
375 
376 	/* all algorithms must implement all ops (for now) */
377 	if (!bat_algo_ops->bat_iface_enable ||
378 	    !bat_algo_ops->bat_iface_disable ||
379 	    !bat_algo_ops->bat_iface_update_mac ||
380 	    !bat_algo_ops->bat_primary_iface_set ||
381 	    !bat_algo_ops->bat_ogm_schedule ||
382 	    !bat_algo_ops->bat_ogm_emit) {
383 		pr_info("Routing algo '%s' does not implement required ops\n",
384 			bat_algo_ops->name);
385 		ret = -EINVAL;
386 		goto out;
387 	}
388 
389 	INIT_HLIST_NODE(&bat_algo_ops->list);
390 	hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
391 	ret = 0;
392 
393 out:
394 	return ret;
395 }
396 
397 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
398 {
399 	struct batadv_algo_ops *bat_algo_ops;
400 	int ret = -EINVAL;
401 
402 	bat_algo_ops = batadv_algo_get(name);
403 	if (!bat_algo_ops)
404 		goto out;
405 
406 	bat_priv->bat_algo_ops = bat_algo_ops;
407 	ret = 0;
408 
409 out:
410 	return ret;
411 }
412 
413 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
414 {
415 	struct batadv_algo_ops *bat_algo_ops;
416 
417 	seq_printf(seq, "Available routing algorithms:\n");
418 
419 	hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
420 		seq_printf(seq, "%s\n", bat_algo_ops->name);
421 	}
422 
423 	return 0;
424 }
425 
426 /**
427  * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
428  *  the header
429  * @skb: skb pointing to fragmented socket buffers
430  * @payload_ptr: Pointer to position inside the head buffer of the skb
431  *  marking the start of the data to be CRC'ed
432  *
433  * payload_ptr must always point to an address in the skb head buffer and not to
434  * a fragment.
435  */
436 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
437 {
438 	u32 crc = 0;
439 	unsigned int from;
440 	unsigned int to = skb->len;
441 	struct skb_seq_state st;
442 	const u8 *data;
443 	unsigned int len;
444 	unsigned int consumed = 0;
445 
446 	from = (unsigned int)(payload_ptr - skb->data);
447 
448 	skb_prepare_seq_read(skb, from, to, &st);
449 	while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
450 		crc = crc32c(crc, data, len);
451 		consumed += len;
452 	}
453 	skb_abort_seq_read(&st);
454 
455 	return htonl(crc);
456 }
457 
458 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
459 {
460 	struct batadv_algo_ops *bat_algo_ops;
461 	char *algo_name = (char *)val;
462 	size_t name_len = strlen(algo_name);
463 
464 	if (algo_name[name_len - 1] == '\n')
465 		algo_name[name_len - 1] = '\0';
466 
467 	bat_algo_ops = batadv_algo_get(algo_name);
468 	if (!bat_algo_ops) {
469 		pr_err("Routing algorithm '%s' is not supported\n", algo_name);
470 		return -EINVAL;
471 	}
472 
473 	return param_set_copystring(algo_name, kp);
474 }
475 
476 static const struct kernel_param_ops batadv_param_ops_ra = {
477 	.set = batadv_param_set_ra,
478 	.get = param_get_string,
479 };
480 
481 static struct kparam_string batadv_param_string_ra = {
482 	.maxlen = sizeof(batadv_routing_algo),
483 	.string = batadv_routing_algo,
484 };
485 
486 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
487 		0644);
488 module_init(batadv_init);
489 module_exit(batadv_exit);
490 
491 MODULE_LICENSE("GPL");
492 
493 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
494 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
495 MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
496 MODULE_VERSION(BATADV_SOURCE_VERSION);
497