xref: /linux/net/batman-adv/main.c (revision e5c5d22e8dcf7c2d430336cbf8e180bd38e8daf1)
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 #include "network-coding.h"
39 
40 
41 /* List manipulations on hardif_list have to be rtnl_lock()'ed,
42  * list traversals just rcu-locked
43  */
44 struct list_head batadv_hardif_list;
45 static int (*batadv_rx_handler[256])(struct sk_buff *,
46 				     struct batadv_hard_iface *);
47 char batadv_routing_algo[20] = "BATMAN_IV";
48 static struct hlist_head batadv_algo_list;
49 
50 unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
51 
52 struct workqueue_struct *batadv_event_workqueue;
53 
54 static void batadv_recv_handler_init(void);
55 
56 static int __init batadv_init(void)
57 {
58 	INIT_LIST_HEAD(&batadv_hardif_list);
59 	INIT_HLIST_HEAD(&batadv_algo_list);
60 
61 	batadv_recv_handler_init();
62 
63 	batadv_iv_init();
64 
65 	batadv_event_workqueue = create_singlethread_workqueue("bat_events");
66 
67 	if (!batadv_event_workqueue)
68 		return -ENOMEM;
69 
70 	batadv_socket_init();
71 	batadv_debugfs_init();
72 
73 	register_netdevice_notifier(&batadv_hard_if_notifier);
74 
75 	pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
76 		BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
77 
78 	return 0;
79 }
80 
81 static void __exit batadv_exit(void)
82 {
83 	batadv_debugfs_destroy();
84 	unregister_netdevice_notifier(&batadv_hard_if_notifier);
85 	batadv_hardif_remove_interfaces();
86 
87 	flush_workqueue(batadv_event_workqueue);
88 	destroy_workqueue(batadv_event_workqueue);
89 	batadv_event_workqueue = NULL;
90 
91 	rcu_barrier();
92 }
93 
94 int batadv_mesh_init(struct net_device *soft_iface)
95 {
96 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
97 	int ret;
98 
99 	spin_lock_init(&bat_priv->forw_bat_list_lock);
100 	spin_lock_init(&bat_priv->forw_bcast_list_lock);
101 	spin_lock_init(&bat_priv->tt.changes_list_lock);
102 	spin_lock_init(&bat_priv->tt.req_list_lock);
103 	spin_lock_init(&bat_priv->tt.roam_list_lock);
104 	spin_lock_init(&bat_priv->tt.last_changeset_lock);
105 	spin_lock_init(&bat_priv->gw.list_lock);
106 	spin_lock_init(&bat_priv->vis.hash_lock);
107 	spin_lock_init(&bat_priv->vis.list_lock);
108 
109 	INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
110 	INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
111 	INIT_HLIST_HEAD(&bat_priv->gw.list);
112 	INIT_LIST_HEAD(&bat_priv->tt.changes_list);
113 	INIT_LIST_HEAD(&bat_priv->tt.req_list);
114 	INIT_LIST_HEAD(&bat_priv->tt.roam_list);
115 
116 	ret = batadv_originator_init(bat_priv);
117 	if (ret < 0)
118 		goto err;
119 
120 	ret = batadv_tt_init(bat_priv);
121 	if (ret < 0)
122 		goto err;
123 
124 	batadv_tt_local_add(soft_iface, soft_iface->dev_addr,
125 			    BATADV_NULL_IFINDEX);
126 
127 	ret = batadv_vis_init(bat_priv);
128 	if (ret < 0)
129 		goto err;
130 
131 	ret = batadv_bla_init(bat_priv);
132 	if (ret < 0)
133 		goto err;
134 
135 	ret = batadv_dat_init(bat_priv);
136 	if (ret < 0)
137 		goto err;
138 
139 	ret = batadv_nc_init(bat_priv);
140 	if (ret < 0)
141 		goto err;
142 
143 	atomic_set(&bat_priv->gw.reselect, 0);
144 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
145 
146 	return 0;
147 
148 err:
149 	batadv_mesh_free(soft_iface);
150 	return ret;
151 }
152 
153 void batadv_mesh_free(struct net_device *soft_iface)
154 {
155 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
156 
157 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
158 
159 	batadv_purge_outstanding_packets(bat_priv, NULL);
160 
161 	batadv_vis_quit(bat_priv);
162 
163 	batadv_gw_node_purge(bat_priv);
164 	batadv_originator_free(bat_priv);
165 	batadv_nc_free(bat_priv);
166 
167 	batadv_tt_free(bat_priv);
168 
169 	batadv_bla_free(bat_priv);
170 
171 	batadv_dat_free(bat_priv);
172 
173 	free_percpu(bat_priv->bat_counters);
174 
175 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
176 }
177 
178 int batadv_is_my_mac(const uint8_t *addr)
179 {
180 	const struct batadv_hard_iface *hard_iface;
181 
182 	rcu_read_lock();
183 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
184 		if (hard_iface->if_status != BATADV_IF_ACTIVE)
185 			continue;
186 
187 		if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
188 			rcu_read_unlock();
189 			return 1;
190 		}
191 	}
192 	rcu_read_unlock();
193 	return 0;
194 }
195 
196 /**
197  * batadv_seq_print_text_primary_if_get - called from debugfs table printing
198  *  function that requires the primary interface
199  * @seq: debugfs table seq_file struct
200  *
201  * Returns primary interface if found or NULL otherwise.
202  */
203 struct batadv_hard_iface *
204 batadv_seq_print_text_primary_if_get(struct seq_file *seq)
205 {
206 	struct net_device *net_dev = (struct net_device *)seq->private;
207 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
208 	struct batadv_hard_iface *primary_if;
209 
210 	primary_if = batadv_primary_if_get_selected(bat_priv);
211 
212 	if (!primary_if) {
213 		seq_printf(seq,
214 			   "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
215 			   net_dev->name);
216 		goto out;
217 	}
218 
219 	if (primary_if->if_status == BATADV_IF_ACTIVE)
220 		goto out;
221 
222 	seq_printf(seq,
223 		   "BATMAN mesh %s disabled - primary interface not active\n",
224 		   net_dev->name);
225 	batadv_hardif_free_ref(primary_if);
226 	primary_if = NULL;
227 
228 out:
229 	return primary_if;
230 }
231 
232 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
233 					struct batadv_hard_iface *recv_if)
234 {
235 	return NET_RX_DROP;
236 }
237 
238 /* incoming packets with the batman ethertype received on any active hard
239  * interface
240  */
241 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
242 			   struct packet_type *ptype,
243 			   struct net_device *orig_dev)
244 {
245 	struct batadv_priv *bat_priv;
246 	struct batadv_ogm_packet *batadv_ogm_packet;
247 	struct batadv_hard_iface *hard_iface;
248 	uint8_t idx;
249 	int ret;
250 
251 	hard_iface = container_of(ptype, struct batadv_hard_iface,
252 				  batman_adv_ptype);
253 	skb = skb_share_check(skb, GFP_ATOMIC);
254 
255 	/* skb was released by skb_share_check() */
256 	if (!skb)
257 		goto err_out;
258 
259 	/* packet should hold at least type and version */
260 	if (unlikely(!pskb_may_pull(skb, 2)))
261 		goto err_free;
262 
263 	/* expect a valid ethernet header here. */
264 	if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
265 		goto err_free;
266 
267 	if (!hard_iface->soft_iface)
268 		goto err_free;
269 
270 	bat_priv = netdev_priv(hard_iface->soft_iface);
271 
272 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
273 		goto err_free;
274 
275 	/* discard frames on not active interfaces */
276 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
277 		goto err_free;
278 
279 	batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
280 
281 	if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
282 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
283 			   "Drop packet: incompatible batman version (%i)\n",
284 			   batadv_ogm_packet->header.version);
285 		goto err_free;
286 	}
287 
288 	/* all receive handlers return whether they received or reused
289 	 * the supplied skb. if not, we have to free the skb.
290 	 */
291 	idx = batadv_ogm_packet->header.packet_type;
292 	ret = (*batadv_rx_handler[idx])(skb, hard_iface);
293 
294 	if (ret == NET_RX_DROP)
295 		kfree_skb(skb);
296 
297 	/* return NET_RX_SUCCESS in any case as we
298 	 * most probably dropped the packet for
299 	 * routing-logical reasons.
300 	 */
301 	return NET_RX_SUCCESS;
302 
303 err_free:
304 	kfree_skb(skb);
305 err_out:
306 	return NET_RX_DROP;
307 }
308 
309 static void batadv_recv_handler_init(void)
310 {
311 	int i;
312 
313 	for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
314 		batadv_rx_handler[i] = batadv_recv_unhandled_packet;
315 
316 	/* batman icmp packet */
317 	batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
318 	/* unicast with 4 addresses packet */
319 	batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
320 	/* unicast packet */
321 	batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
322 	/* fragmented unicast packet */
323 	batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
324 	/* broadcast packet */
325 	batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
326 	/* vis packet */
327 	batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
328 	/* Translation table query (request or response) */
329 	batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
330 	/* Roaming advertisement */
331 	batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
332 }
333 
334 int
335 batadv_recv_handler_register(uint8_t packet_type,
336 			     int (*recv_handler)(struct sk_buff *,
337 						 struct batadv_hard_iface *))
338 {
339 	if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
340 		return -EBUSY;
341 
342 	batadv_rx_handler[packet_type] = recv_handler;
343 	return 0;
344 }
345 
346 void batadv_recv_handler_unregister(uint8_t packet_type)
347 {
348 	batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
349 }
350 
351 static struct batadv_algo_ops *batadv_algo_get(char *name)
352 {
353 	struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
354 
355 	hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
356 		if (strcmp(bat_algo_ops_tmp->name, name) != 0)
357 			continue;
358 
359 		bat_algo_ops = bat_algo_ops_tmp;
360 		break;
361 	}
362 
363 	return bat_algo_ops;
364 }
365 
366 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
367 {
368 	struct batadv_algo_ops *bat_algo_ops_tmp;
369 	int ret;
370 
371 	bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
372 	if (bat_algo_ops_tmp) {
373 		pr_info("Trying to register already registered routing algorithm: %s\n",
374 			bat_algo_ops->name);
375 		ret = -EEXIST;
376 		goto out;
377 	}
378 
379 	/* all algorithms must implement all ops (for now) */
380 	if (!bat_algo_ops->bat_iface_enable ||
381 	    !bat_algo_ops->bat_iface_disable ||
382 	    !bat_algo_ops->bat_iface_update_mac ||
383 	    !bat_algo_ops->bat_primary_iface_set ||
384 	    !bat_algo_ops->bat_ogm_schedule ||
385 	    !bat_algo_ops->bat_ogm_emit) {
386 		pr_info("Routing algo '%s' does not implement required ops\n",
387 			bat_algo_ops->name);
388 		ret = -EINVAL;
389 		goto out;
390 	}
391 
392 	INIT_HLIST_NODE(&bat_algo_ops->list);
393 	hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
394 	ret = 0;
395 
396 out:
397 	return ret;
398 }
399 
400 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
401 {
402 	struct batadv_algo_ops *bat_algo_ops;
403 	int ret = -EINVAL;
404 
405 	bat_algo_ops = batadv_algo_get(name);
406 	if (!bat_algo_ops)
407 		goto out;
408 
409 	bat_priv->bat_algo_ops = bat_algo_ops;
410 	ret = 0;
411 
412 out:
413 	return ret;
414 }
415 
416 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
417 {
418 	struct batadv_algo_ops *bat_algo_ops;
419 
420 	seq_printf(seq, "Available routing algorithms:\n");
421 
422 	hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
423 		seq_printf(seq, "%s\n", bat_algo_ops->name);
424 	}
425 
426 	return 0;
427 }
428 
429 /**
430  * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
431  *  the header
432  * @skb: skb pointing to fragmented socket buffers
433  * @payload_ptr: Pointer to position inside the head buffer of the skb
434  *  marking the start of the data to be CRC'ed
435  *
436  * payload_ptr must always point to an address in the skb head buffer and not to
437  * a fragment.
438  */
439 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
440 {
441 	u32 crc = 0;
442 	unsigned int from;
443 	unsigned int to = skb->len;
444 	struct skb_seq_state st;
445 	const u8 *data;
446 	unsigned int len;
447 	unsigned int consumed = 0;
448 
449 	from = (unsigned int)(payload_ptr - skb->data);
450 
451 	skb_prepare_seq_read(skb, from, to, &st);
452 	while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
453 		crc = crc32c(crc, data, len);
454 		consumed += len;
455 	}
456 	skb_abort_seq_read(&st);
457 
458 	return htonl(crc);
459 }
460 
461 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
462 {
463 	struct batadv_algo_ops *bat_algo_ops;
464 	char *algo_name = (char *)val;
465 	size_t name_len = strlen(algo_name);
466 
467 	if (algo_name[name_len - 1] == '\n')
468 		algo_name[name_len - 1] = '\0';
469 
470 	bat_algo_ops = batadv_algo_get(algo_name);
471 	if (!bat_algo_ops) {
472 		pr_err("Routing algorithm '%s' is not supported\n", algo_name);
473 		return -EINVAL;
474 	}
475 
476 	return param_set_copystring(algo_name, kp);
477 }
478 
479 static const struct kernel_param_ops batadv_param_ops_ra = {
480 	.set = batadv_param_set_ra,
481 	.get = param_get_string,
482 };
483 
484 static struct kparam_string batadv_param_string_ra = {
485 	.maxlen = sizeof(batadv_routing_algo),
486 	.string = batadv_routing_algo,
487 };
488 
489 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
490 		0644);
491 module_init(batadv_init);
492 module_exit(batadv_exit);
493 
494 MODULE_LICENSE("GPL");
495 
496 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
497 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
498 MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
499 MODULE_VERSION(BATADV_SOURCE_VERSION);
500