summaryrefslogtreecommitdiff
path: root/net/batman-adv/send.c
blob: 413758065323767a3258a68ee00d8c1ef24bd4a5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
/*
 * Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
 *
 * Marek Lindner, Simon Wunderlich
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 *
 */

#include "main.h"
#include "send.h"
#include "routing.h"
#include "translation-table.h"
#include "soft-interface.h"
#include "hard-interface.h"
#include "vis.h"
#include "gateway_common.h"
#include "originator.h"

static void send_outstanding_bcast_packet(struct work_struct *work);

/* send out an already prepared packet to the given address via the
 * specified batman interface */
int send_skb_packet(struct sk_buff *skb, struct hard_iface *hard_iface,
		    const uint8_t *dst_addr)
{
	struct ethhdr *ethhdr;

	if (hard_iface->if_status != IF_ACTIVE)
		goto send_skb_err;

	if (unlikely(!hard_iface->net_dev))
		goto send_skb_err;

	if (!(hard_iface->net_dev->flags & IFF_UP)) {
		pr_warning("Interface %s is not up - can't send packet via "
			   "that interface!\n", hard_iface->net_dev->name);
		goto send_skb_err;
	}

	/* push to the ethernet header. */
	if (my_skb_head_push(skb, sizeof(*ethhdr)) < 0)
		goto send_skb_err;

	skb_reset_mac_header(skb);

	ethhdr = (struct ethhdr *) skb_mac_header(skb);
	memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
	memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
	ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);

	skb_set_network_header(skb, ETH_HLEN);
	skb->priority = TC_PRIO_CONTROL;
	skb->protocol = __constant_htons(ETH_P_BATMAN);

	skb->dev = hard_iface->net_dev;

	/* dev_queue_xmit() returns a negative result on error.	 However on
	 * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
	 * (which is > 0). This will not be treated as an error. */

	return dev_queue_xmit(skb);
send_skb_err:
	kfree_skb(skb);
	return NET_XMIT_DROP;
}

static void realloc_packet_buffer(struct hard_iface *hard_iface,
				  int new_len)
{
	unsigned char *new_buff;

	new_buff = kmalloc(new_len, GFP_ATOMIC);

	/* keep old buffer if kmalloc should fail */
	if (new_buff) {
		memcpy(new_buff, hard_iface->packet_buff,
		       BATMAN_OGM_LEN);

		kfree(hard_iface->packet_buff);
		hard_iface->packet_buff = new_buff;
		hard_iface->packet_len = new_len;
	}
}

/* when calling this function (hard_iface == primary_if) has to be true */
static int prepare_packet_buffer(struct bat_priv *bat_priv,
				  struct hard_iface *hard_iface)
{
	int new_len;

	new_len = BATMAN_OGM_LEN +
		  tt_len((uint8_t)atomic_read(&bat_priv->tt_local_changes));

	/* if we have too many changes for one packet don't send any
	 * and wait for the tt table request which will be fragmented */
	if (new_len > hard_iface->soft_iface->mtu)
		new_len = BATMAN_OGM_LEN;

	realloc_packet_buffer(hard_iface, new_len);

	atomic_set(&bat_priv->tt_crc, tt_local_crc(bat_priv));

	/* reset the sending counter */
	atomic_set(&bat_priv->tt_ogm_append_cnt, TT_OGM_APPEND_MAX);

	return tt_changes_fill_buffer(bat_priv,
				      hard_iface->packet_buff + BATMAN_OGM_LEN,
				      hard_iface->packet_len - BATMAN_OGM_LEN);
}

static int reset_packet_buffer(struct bat_priv *bat_priv,
				struct hard_iface *hard_iface)
{
	realloc_packet_buffer(hard_iface, BATMAN_OGM_LEN);
	return 0;
}

void schedule_bat_ogm(struct hard_iface *hard_iface)
{
	struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
	struct hard_iface *primary_if;
	int tt_num_changes = -1;

	if ((hard_iface->if_status == IF_NOT_IN_USE) ||
	    (hard_iface->if_status == IF_TO_BE_REMOVED))
		return;

	/**
	 * the interface gets activated here to avoid race conditions between
	 * the moment of activating the interface in
	 * hardif_activate_interface() where the originator mac is set and
	 * outdated packets (especially uninitialized mac addresses) in the
	 * packet queue
	 */
	if (hard_iface->if_status == IF_TO_BE_ACTIVATED)
		hard_iface->if_status = IF_ACTIVE;

	primary_if = primary_if_get_selected(bat_priv);

	if (hard_iface == primary_if) {
		/* if at least one change happened */
		if (atomic_read(&bat_priv->tt_local_changes) > 0) {
			tt_commit_changes(bat_priv);
			tt_num_changes = prepare_packet_buffer(bat_priv,
							       hard_iface);
		}

		/* if the changes have been sent often enough */
		if (!atomic_dec_not_zero(&bat_priv->tt_ogm_append_cnt))
			tt_num_changes = reset_packet_buffer(bat_priv,
							     hard_iface);
	}

	if (primary_if)
		hardif_free_ref(primary_if);

	bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface, tt_num_changes);
}

static void forw_packet_free(struct forw_packet *forw_packet)
{
	if (forw_packet->skb)
		kfree_skb(forw_packet->skb);
	if (forw_packet->if_incoming)
		hardif_free_ref(forw_packet->if_incoming);
	kfree(forw_packet);
}

static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
				      struct forw_packet *forw_packet,
				      unsigned long send_time)
{
	INIT_HLIST_NODE(&forw_packet->list);

	/* add new packet to packet list */
	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
	hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

	/* start timer for this packet */
	INIT_DELAYED_WORK(&forw_packet->delayed_work,
			  send_outstanding_bcast_packet);
	queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
			   send_time);
}

/* add a broadcast packet to the queue and setup timers. broadcast packets
 * are sent multiple times to increase probability for being received.
 *
 * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
 * errors.
 *
 * The skb is not consumed, so the caller should make sure that the
 * skb is freed. */
int add_bcast_packet_to_list(struct bat_priv *bat_priv,
			     const struct sk_buff *skb, unsigned long delay)
{
	struct hard_iface *primary_if = NULL;
	struct forw_packet *forw_packet;
	struct bcast_packet *bcast_packet;
	struct sk_buff *newskb;

	if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
		bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
		goto out;
	}

	primary_if = primary_if_get_selected(bat_priv);
	if (!primary_if)
		goto out_and_inc;

	forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);

	if (!forw_packet)
		goto out_and_inc;

	newskb = skb_copy(skb, GFP_ATOMIC);
	if (!newskb)
		goto packet_free;

	/* as we have a copy now, it is safe to decrease the TTL */
	bcast_packet = (struct bcast_packet *)newskb->data;
	bcast_packet->header.ttl--;

	skb_reset_mac_header(newskb);

	forw_packet->skb = newskb;
	forw_packet->if_incoming = primary_if;

	/* how often did we send the bcast packet ? */
	forw_packet->num_packets = 0;

	_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
	return NETDEV_TX_OK;

packet_free:
	kfree(forw_packet);
out_and_inc:
	atomic_inc(&bat_priv->bcast_queue_left);
out:
	if (primary_if)
		hardif_free_ref(primary_if);
	return NETDEV_TX_BUSY;
}

static void send_outstanding_bcast_packet(struct work_struct *work)
{
	struct hard_iface *hard_iface;
	struct delayed_work *delayed_work =
		container_of(work, struct delayed_work, work);
	struct forw_packet *forw_packet =
		container_of(delayed_work, struct forw_packet, delayed_work);
	struct sk_buff *skb1;
	struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
	struct bat_priv *bat_priv = netdev_priv(soft_iface);

	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
	hlist_del(&forw_packet->list);
	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

	if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
		goto out;

	/* rebroadcast packet */
	rcu_read_lock();
	list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
		if (hard_iface->soft_iface != soft_iface)
			continue;

		/* send a copy of the saved skb */
		skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
		if (skb1)
			send_skb_packet(skb1, hard_iface, broadcast_addr);
	}
	rcu_read_unlock();

	forw_packet->num_packets++;

	/* if we still have some more bcasts to send */
	if (forw_packet->num_packets < 3) {
		_add_bcast_packet_to_list(bat_priv, forw_packet,
					  ((5 * HZ) / 1000));
		return;
	}

out:
	forw_packet_free(forw_packet);
	atomic_inc(&bat_priv->bcast_queue_left);
}

void send_outstanding_bat_ogm_packet(struct work_struct *work)
{
	struct delayed_work *delayed_work =
		container_of(work, struct delayed_work, work);
	struct forw_packet *forw_packet =
		container_of(delayed_work, struct forw_packet, delayed_work);
	struct bat_priv *bat_priv;

	bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
	spin_lock_bh(&bat_priv->forw_bat_list_lock);
	hlist_del(&forw_packet->list);
	spin_unlock_bh(&bat_priv->forw_bat_list_lock);

	if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
		goto out;

	bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);

	/**
	 * we have to have at least one packet in the queue
	 * to determine the queues wake up time unless we are
	 * shutting down
	 */
	if (forw_packet->own)
		schedule_bat_ogm(forw_packet->if_incoming);

out:
	/* don't count own packet */
	if (!forw_packet->own)
		atomic_inc(&bat_priv->batman_queue_left);

	forw_packet_free(forw_packet);
}

void purge_outstanding_packets(struct bat_priv *bat_priv,
			       const struct hard_iface *hard_iface)
{
	struct forw_packet *forw_packet;
	struct hlist_node *tmp_node, *safe_tmp_node;
	bool pending;

	if (hard_iface)
		bat_dbg(DBG_BATMAN, bat_priv,
			"purge_outstanding_packets(): %s\n",
			hard_iface->net_dev->name);
	else
		bat_dbg(DBG_BATMAN, bat_priv,
			"purge_outstanding_packets()\n");

	/* free bcast list */
	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
	hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
				  &bat_priv->forw_bcast_list, list) {

		/**
		 * if purge_outstanding_packets() was called with an argument
		 * we delete only packets belonging to the given interface
		 */
		if ((hard_iface) &&
		    (forw_packet->if_incoming != hard_iface))
			continue;

		spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

		/**
		 * send_outstanding_bcast_packet() will lock the list to
		 * delete the item from the list
		 */
		pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
		spin_lock_bh(&bat_priv->forw_bcast_list_lock);

		if (pending) {
			hlist_del(&forw_packet->list);
			forw_packet_free(forw_packet);
		}
	}
	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);

	/* free batman packet list */
	spin_lock_bh(&bat_priv->forw_bat_list_lock);
	hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
				  &bat_priv->forw_bat_list, list) {

		/**
		 * if purge_outstanding_packets() was called with an argument
		 * we delete only packets belonging to the given interface
		 */
		if ((hard_iface) &&
		    (forw_packet->if_incoming != hard_iface))
			continue;

		spin_unlock_bh(&bat_priv->forw_bat_list_lock);

		/**
		 * send_outstanding_bat_packet() will lock the list to
		 * delete the item from the list
		 */
		pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
		spin_lock_bh(&bat_priv->forw_bat_list_lock);

		if (pending) {
			hlist_del(&forw_packet->list);
			forw_packet_free(forw_packet);
		}
	}
	spin_unlock_bh(&bat_priv->forw_bat_list_lock);
}