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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 
batadv_init(void)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 	rtnl_link_register(&batadv_link_ops);
75 
76 	pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
77 		BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
78 
79 	return 0;
80 }
81 
batadv_exit(void)82 static void __exit batadv_exit(void)
83 {
84 	batadv_debugfs_destroy();
85 	rtnl_link_unregister(&batadv_link_ops);
86 	unregister_netdevice_notifier(&batadv_hard_if_notifier);
87 	batadv_hardif_remove_interfaces();
88 
89 	flush_workqueue(batadv_event_workqueue);
90 	destroy_workqueue(batadv_event_workqueue);
91 	batadv_event_workqueue = NULL;
92 
93 	rcu_barrier();
94 }
95 
batadv_mesh_init(struct net_device * soft_iface)96 int batadv_mesh_init(struct net_device *soft_iface)
97 {
98 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
99 	int ret;
100 
101 	spin_lock_init(&bat_priv->forw_bat_list_lock);
102 	spin_lock_init(&bat_priv->forw_bcast_list_lock);
103 	spin_lock_init(&bat_priv->tt.changes_list_lock);
104 	spin_lock_init(&bat_priv->tt.req_list_lock);
105 	spin_lock_init(&bat_priv->tt.roam_list_lock);
106 	spin_lock_init(&bat_priv->tt.last_changeset_lock);
107 	spin_lock_init(&bat_priv->gw.list_lock);
108 	spin_lock_init(&bat_priv->vis.hash_lock);
109 	spin_lock_init(&bat_priv->vis.list_lock);
110 
111 	INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
112 	INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
113 	INIT_HLIST_HEAD(&bat_priv->gw.list);
114 	INIT_LIST_HEAD(&bat_priv->tt.changes_list);
115 	INIT_LIST_HEAD(&bat_priv->tt.req_list);
116 	INIT_LIST_HEAD(&bat_priv->tt.roam_list);
117 
118 	ret = batadv_originator_init(bat_priv);
119 	if (ret < 0)
120 		goto err;
121 
122 	ret = batadv_tt_init(bat_priv);
123 	if (ret < 0)
124 		goto err;
125 
126 	batadv_tt_local_add(soft_iface, soft_iface->dev_addr,
127 			    BATADV_NULL_IFINDEX);
128 
129 	ret = batadv_vis_init(bat_priv);
130 	if (ret < 0)
131 		goto err;
132 
133 	ret = batadv_bla_init(bat_priv);
134 	if (ret < 0)
135 		goto err;
136 
137 	ret = batadv_dat_init(bat_priv);
138 	if (ret < 0)
139 		goto err;
140 
141 	ret = batadv_nc_init(bat_priv);
142 	if (ret < 0)
143 		goto err;
144 
145 	atomic_set(&bat_priv->gw.reselect, 0);
146 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);
147 
148 	return 0;
149 
150 err:
151 	batadv_mesh_free(soft_iface);
152 	return ret;
153 }
154 
batadv_mesh_free(struct net_device * soft_iface)155 void batadv_mesh_free(struct net_device *soft_iface)
156 {
157 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
158 
159 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);
160 
161 	batadv_purge_outstanding_packets(bat_priv, NULL);
162 
163 	batadv_vis_quit(bat_priv);
164 
165 	batadv_gw_node_purge(bat_priv);
166 	batadv_nc_free(bat_priv);
167 	batadv_dat_free(bat_priv);
168 	batadv_bla_free(bat_priv);
169 
170 	/* Free the TT and the originator tables only after having terminated
171 	 * all the other depending components which may use these structures for
172 	 * their purposes.
173 	 */
174 	batadv_tt_free(bat_priv);
175 
176 	/* Since the originator table clean up routine is accessing the TT
177 	 * tables as well, it has to be invoked after the TT tables have been
178 	 * freed and marked as empty. This ensures that no cleanup RCU callbacks
179 	 * accessing the TT data are scheduled for later execution.
180 	 */
181 	batadv_originator_free(bat_priv);
182 
183 	free_percpu(bat_priv->bat_counters);
184 	bat_priv->bat_counters = NULL;
185 
186 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
187 }
188 
189 /**
190  * batadv_is_my_mac - check if the given mac address belongs to any of the real
191  * interfaces in the current mesh
192  * @bat_priv: the bat priv with all the soft interface information
193  * @addr: the address to check
194  */
batadv_is_my_mac(struct batadv_priv * bat_priv,const uint8_t * addr)195 int batadv_is_my_mac(struct batadv_priv *bat_priv, const uint8_t *addr)
196 {
197 	const struct batadv_hard_iface *hard_iface;
198 
199 	rcu_read_lock();
200 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
201 		if (hard_iface->if_status != BATADV_IF_ACTIVE)
202 			continue;
203 
204 		if (hard_iface->soft_iface != bat_priv->soft_iface)
205 			continue;
206 
207 		if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
208 			rcu_read_unlock();
209 			return 1;
210 		}
211 	}
212 	rcu_read_unlock();
213 	return 0;
214 }
215 
216 /**
217  * batadv_seq_print_text_primary_if_get - called from debugfs table printing
218  *  function that requires the primary interface
219  * @seq: debugfs table seq_file struct
220  *
221  * Returns primary interface if found or NULL otherwise.
222  */
223 struct batadv_hard_iface *
batadv_seq_print_text_primary_if_get(struct seq_file * seq)224 batadv_seq_print_text_primary_if_get(struct seq_file *seq)
225 {
226 	struct net_device *net_dev = (struct net_device *)seq->private;
227 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
228 	struct batadv_hard_iface *primary_if;
229 
230 	primary_if = batadv_primary_if_get_selected(bat_priv);
231 
232 	if (!primary_if) {
233 		seq_printf(seq,
234 			   "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
235 			   net_dev->name);
236 		goto out;
237 	}
238 
239 	if (primary_if->if_status == BATADV_IF_ACTIVE)
240 		goto out;
241 
242 	seq_printf(seq,
243 		   "BATMAN mesh %s disabled - primary interface not active\n",
244 		   net_dev->name);
245 	batadv_hardif_free_ref(primary_if);
246 	primary_if = NULL;
247 
248 out:
249 	return primary_if;
250 }
251 
batadv_recv_unhandled_packet(struct sk_buff * skb,struct batadv_hard_iface * recv_if)252 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
253 					struct batadv_hard_iface *recv_if)
254 {
255 	return NET_RX_DROP;
256 }
257 
258 /* incoming packets with the batman ethertype received on any active hard
259  * interface
260  */
batadv_batman_skb_recv(struct sk_buff * skb,struct net_device * dev,struct packet_type * ptype,struct net_device * orig_dev)261 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
262 			   struct packet_type *ptype,
263 			   struct net_device *orig_dev)
264 {
265 	struct batadv_priv *bat_priv;
266 	struct batadv_ogm_packet *batadv_ogm_packet;
267 	struct batadv_hard_iface *hard_iface;
268 	uint8_t idx;
269 	int ret;
270 
271 	hard_iface = container_of(ptype, struct batadv_hard_iface,
272 				  batman_adv_ptype);
273 	skb = skb_share_check(skb, GFP_ATOMIC);
274 
275 	/* skb was released by skb_share_check() */
276 	if (!skb)
277 		goto err_out;
278 
279 	/* packet should hold at least type and version */
280 	if (unlikely(!pskb_may_pull(skb, 2)))
281 		goto err_free;
282 
283 	/* expect a valid ethernet header here. */
284 	if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
285 		goto err_free;
286 
287 	if (!hard_iface->soft_iface)
288 		goto err_free;
289 
290 	bat_priv = netdev_priv(hard_iface->soft_iface);
291 
292 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
293 		goto err_free;
294 
295 	/* discard frames on not active interfaces */
296 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
297 		goto err_free;
298 
299 	batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;
300 
301 	if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
302 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
303 			   "Drop packet: incompatible batman version (%i)\n",
304 			   batadv_ogm_packet->header.version);
305 		goto err_free;
306 	}
307 
308 	/* all receive handlers return whether they received or reused
309 	 * the supplied skb. if not, we have to free the skb.
310 	 */
311 	idx = batadv_ogm_packet->header.packet_type;
312 	ret = (*batadv_rx_handler[idx])(skb, hard_iface);
313 
314 	if (ret == NET_RX_DROP)
315 		kfree_skb(skb);
316 
317 	/* return NET_RX_SUCCESS in any case as we
318 	 * most probably dropped the packet for
319 	 * routing-logical reasons.
320 	 */
321 	return NET_RX_SUCCESS;
322 
323 err_free:
324 	kfree_skb(skb);
325 err_out:
326 	return NET_RX_DROP;
327 }
328 
batadv_recv_handler_init(void)329 static void batadv_recv_handler_init(void)
330 {
331 	int i;
332 
333 	for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
334 		batadv_rx_handler[i] = batadv_recv_unhandled_packet;
335 
336 	/* batman icmp packet */
337 	batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
338 	/* unicast with 4 addresses packet */
339 	batadv_rx_handler[BATADV_UNICAST_4ADDR] = batadv_recv_unicast_packet;
340 	/* unicast packet */
341 	batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
342 	/* fragmented unicast packet */
343 	batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
344 	/* broadcast packet */
345 	batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
346 	/* vis packet */
347 	batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
348 	/* Translation table query (request or response) */
349 	batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
350 	/* Roaming advertisement */
351 	batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
352 }
353 
354 int
batadv_recv_handler_register(uint8_t packet_type,int (* recv_handler)(struct sk_buff *,struct batadv_hard_iface *))355 batadv_recv_handler_register(uint8_t packet_type,
356 			     int (*recv_handler)(struct sk_buff *,
357 						 struct batadv_hard_iface *))
358 {
359 	if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
360 		return -EBUSY;
361 
362 	batadv_rx_handler[packet_type] = recv_handler;
363 	return 0;
364 }
365 
batadv_recv_handler_unregister(uint8_t packet_type)366 void batadv_recv_handler_unregister(uint8_t packet_type)
367 {
368 	batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
369 }
370 
batadv_algo_get(char * name)371 static struct batadv_algo_ops *batadv_algo_get(char *name)
372 {
373 	struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
374 
375 	hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
376 		if (strcmp(bat_algo_ops_tmp->name, name) != 0)
377 			continue;
378 
379 		bat_algo_ops = bat_algo_ops_tmp;
380 		break;
381 	}
382 
383 	return bat_algo_ops;
384 }
385 
batadv_algo_register(struct batadv_algo_ops * bat_algo_ops)386 int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
387 {
388 	struct batadv_algo_ops *bat_algo_ops_tmp;
389 	int ret;
390 
391 	bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
392 	if (bat_algo_ops_tmp) {
393 		pr_info("Trying to register already registered routing algorithm: %s\n",
394 			bat_algo_ops->name);
395 		ret = -EEXIST;
396 		goto out;
397 	}
398 
399 	/* all algorithms must implement all ops (for now) */
400 	if (!bat_algo_ops->bat_iface_enable ||
401 	    !bat_algo_ops->bat_iface_disable ||
402 	    !bat_algo_ops->bat_iface_update_mac ||
403 	    !bat_algo_ops->bat_primary_iface_set ||
404 	    !bat_algo_ops->bat_ogm_schedule ||
405 	    !bat_algo_ops->bat_ogm_emit) {
406 		pr_info("Routing algo '%s' does not implement required ops\n",
407 			bat_algo_ops->name);
408 		ret = -EINVAL;
409 		goto out;
410 	}
411 
412 	INIT_HLIST_NODE(&bat_algo_ops->list);
413 	hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
414 	ret = 0;
415 
416 out:
417 	return ret;
418 }
419 
batadv_algo_select(struct batadv_priv * bat_priv,char * name)420 int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
421 {
422 	struct batadv_algo_ops *bat_algo_ops;
423 	int ret = -EINVAL;
424 
425 	bat_algo_ops = batadv_algo_get(name);
426 	if (!bat_algo_ops)
427 		goto out;
428 
429 	bat_priv->bat_algo_ops = bat_algo_ops;
430 	ret = 0;
431 
432 out:
433 	return ret;
434 }
435 
batadv_algo_seq_print_text(struct seq_file * seq,void * offset)436 int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
437 {
438 	struct batadv_algo_ops *bat_algo_ops;
439 
440 	seq_puts(seq, "Available routing algorithms:\n");
441 
442 	hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
443 		seq_printf(seq, "%s\n", bat_algo_ops->name);
444 	}
445 
446 	return 0;
447 }
448 
449 /**
450  * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in
451  *  the header
452  * @skb: skb pointing to fragmented socket buffers
453  * @payload_ptr: Pointer to position inside the head buffer of the skb
454  *  marking the start of the data to be CRC'ed
455  *
456  * payload_ptr must always point to an address in the skb head buffer and not to
457  * a fragment.
458  */
batadv_skb_crc32(struct sk_buff * skb,u8 * payload_ptr)459 __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
460 {
461 	u32 crc = 0;
462 	unsigned int from;
463 	unsigned int to = skb->len;
464 	struct skb_seq_state st;
465 	const u8 *data;
466 	unsigned int len;
467 	unsigned int consumed = 0;
468 
469 	from = (unsigned int)(payload_ptr - skb->data);
470 
471 	skb_prepare_seq_read(skb, from, to, &st);
472 	while ((len = skb_seq_read(consumed, &data, &st)) != 0) {
473 		crc = crc32c(crc, data, len);
474 		consumed += len;
475 	}
476 	skb_abort_seq_read(&st);
477 
478 	return htonl(crc);
479 }
480 
batadv_param_set_ra(const char * val,const struct kernel_param * kp)481 static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
482 {
483 	struct batadv_algo_ops *bat_algo_ops;
484 	char *algo_name = (char *)val;
485 	size_t name_len = strlen(algo_name);
486 
487 	if (name_len > 0 && algo_name[name_len - 1] == '\n')
488 		algo_name[name_len - 1] = '\0';
489 
490 	bat_algo_ops = batadv_algo_get(algo_name);
491 	if (!bat_algo_ops) {
492 		pr_err("Routing algorithm '%s' is not supported\n", algo_name);
493 		return -EINVAL;
494 	}
495 
496 	return param_set_copystring(algo_name, kp);
497 }
498 
499 static const struct kernel_param_ops batadv_param_ops_ra = {
500 	.set = batadv_param_set_ra,
501 	.get = param_get_string,
502 };
503 
504 static struct kparam_string batadv_param_string_ra = {
505 	.maxlen = sizeof(batadv_routing_algo),
506 	.string = batadv_routing_algo,
507 };
508 
509 module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
510 		0644);
511 module_init(batadv_init);
512 module_exit(batadv_exit);
513 
514 MODULE_LICENSE("GPL");
515 
516 MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
517 MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
518 MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
519 MODULE_VERSION(BATADV_SOURCE_VERSION);
520