xref: /openbmc/linux/net/batman-adv/send.c (revision 95e9fd10)
1 /* Copyright (C) 2007-2012 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 "main.h"
21 #include "send.h"
22 #include "routing.h"
23 #include "translation-table.h"
24 #include "soft-interface.h"
25 #include "hard-interface.h"
26 #include "vis.h"
27 #include "gateway_common.h"
28 #include "originator.h"
29 
30 static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
31 
32 /* send out an already prepared packet to the given address via the
33  * specified batman interface
34  */
35 int batadv_send_skb_packet(struct sk_buff *skb,
36 			   struct batadv_hard_iface *hard_iface,
37 			   const uint8_t *dst_addr)
38 {
39 	struct ethhdr *ethhdr;
40 
41 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
42 		goto send_skb_err;
43 
44 	if (unlikely(!hard_iface->net_dev))
45 		goto send_skb_err;
46 
47 	if (!(hard_iface->net_dev->flags & IFF_UP)) {
48 		pr_warn("Interface %s is not up - can't send packet via that interface!\n",
49 			hard_iface->net_dev->name);
50 		goto send_skb_err;
51 	}
52 
53 	/* push to the ethernet header. */
54 	if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
55 		goto send_skb_err;
56 
57 	skb_reset_mac_header(skb);
58 
59 	ethhdr = (struct ethhdr *)skb_mac_header(skb);
60 	memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
61 	memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
62 	ethhdr->h_proto = __constant_htons(BATADV_ETH_P_BATMAN);
63 
64 	skb_set_network_header(skb, ETH_HLEN);
65 	skb->priority = TC_PRIO_CONTROL;
66 	skb->protocol = __constant_htons(BATADV_ETH_P_BATMAN);
67 
68 	skb->dev = hard_iface->net_dev;
69 
70 	/* dev_queue_xmit() returns a negative result on error.	 However on
71 	 * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
72 	 * (which is > 0). This will not be treated as an error.
73 	 */
74 	return dev_queue_xmit(skb);
75 send_skb_err:
76 	kfree_skb(skb);
77 	return NET_XMIT_DROP;
78 }
79 
80 void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
81 {
82 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
83 
84 	if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
85 	    (hard_iface->if_status == BATADV_IF_TO_BE_REMOVED))
86 		return;
87 
88 	/* the interface gets activated here to avoid race conditions between
89 	 * the moment of activating the interface in
90 	 * hardif_activate_interface() where the originator mac is set and
91 	 * outdated packets (especially uninitialized mac addresses) in the
92 	 * packet queue
93 	 */
94 	if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
95 		hard_iface->if_status = BATADV_IF_ACTIVE;
96 
97 	bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
98 }
99 
100 static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
101 {
102 	if (forw_packet->skb)
103 		kfree_skb(forw_packet->skb);
104 	if (forw_packet->if_incoming)
105 		batadv_hardif_free_ref(forw_packet->if_incoming);
106 	kfree(forw_packet);
107 }
108 
109 static void
110 _batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
111 				 struct batadv_forw_packet *forw_packet,
112 				 unsigned long send_time)
113 {
114 	INIT_HLIST_NODE(&forw_packet->list);
115 
116 	/* add new packet to packet list */
117 	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
118 	hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
119 	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
120 
121 	/* start timer for this packet */
122 	INIT_DELAYED_WORK(&forw_packet->delayed_work,
123 			  batadv_send_outstanding_bcast_packet);
124 	queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
125 			   send_time);
126 }
127 
128 /* add a broadcast packet to the queue and setup timers. broadcast packets
129  * are sent multiple times to increase probability for being received.
130  *
131  * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
132  * errors.
133  *
134  * The skb is not consumed, so the caller should make sure that the
135  * skb is freed.
136  */
137 int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
138 				    const struct sk_buff *skb,
139 				    unsigned long delay)
140 {
141 	struct batadv_hard_iface *primary_if = NULL;
142 	struct batadv_forw_packet *forw_packet;
143 	struct batadv_bcast_packet *bcast_packet;
144 	struct sk_buff *newskb;
145 
146 	if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
147 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
148 			   "bcast packet queue full\n");
149 		goto out;
150 	}
151 
152 	primary_if = batadv_primary_if_get_selected(bat_priv);
153 	if (!primary_if)
154 		goto out_and_inc;
155 
156 	forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
157 
158 	if (!forw_packet)
159 		goto out_and_inc;
160 
161 	newskb = skb_copy(skb, GFP_ATOMIC);
162 	if (!newskb)
163 		goto packet_free;
164 
165 	/* as we have a copy now, it is safe to decrease the TTL */
166 	bcast_packet = (struct batadv_bcast_packet *)newskb->data;
167 	bcast_packet->header.ttl--;
168 
169 	skb_reset_mac_header(newskb);
170 
171 	forw_packet->skb = newskb;
172 	forw_packet->if_incoming = primary_if;
173 
174 	/* how often did we send the bcast packet ? */
175 	forw_packet->num_packets = 0;
176 
177 	_batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
178 	return NETDEV_TX_OK;
179 
180 packet_free:
181 	kfree(forw_packet);
182 out_and_inc:
183 	atomic_inc(&bat_priv->bcast_queue_left);
184 out:
185 	if (primary_if)
186 		batadv_hardif_free_ref(primary_if);
187 	return NETDEV_TX_BUSY;
188 }
189 
190 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
191 {
192 	struct batadv_hard_iface *hard_iface;
193 	struct delayed_work *delayed_work =
194 		container_of(work, struct delayed_work, work);
195 	struct batadv_forw_packet *forw_packet;
196 	struct sk_buff *skb1;
197 	struct net_device *soft_iface;
198 	struct batadv_priv *bat_priv;
199 
200 	forw_packet = container_of(delayed_work, struct batadv_forw_packet,
201 				   delayed_work);
202 	soft_iface = forw_packet->if_incoming->soft_iface;
203 	bat_priv = netdev_priv(soft_iface);
204 
205 	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
206 	hlist_del(&forw_packet->list);
207 	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
208 
209 	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
210 		goto out;
211 
212 	/* rebroadcast packet */
213 	rcu_read_lock();
214 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
215 		if (hard_iface->soft_iface != soft_iface)
216 			continue;
217 
218 		/* send a copy of the saved skb */
219 		skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
220 		if (skb1)
221 			batadv_send_skb_packet(skb1, hard_iface,
222 					       batadv_broadcast_addr);
223 	}
224 	rcu_read_unlock();
225 
226 	forw_packet->num_packets++;
227 
228 	/* if we still have some more bcasts to send */
229 	if (forw_packet->num_packets < 3) {
230 		_batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
231 						 msecs_to_jiffies(5));
232 		return;
233 	}
234 
235 out:
236 	batadv_forw_packet_free(forw_packet);
237 	atomic_inc(&bat_priv->bcast_queue_left);
238 }
239 
240 void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
241 {
242 	struct delayed_work *delayed_work =
243 		container_of(work, struct delayed_work, work);
244 	struct batadv_forw_packet *forw_packet;
245 	struct batadv_priv *bat_priv;
246 
247 	forw_packet = container_of(delayed_work, struct batadv_forw_packet,
248 				   delayed_work);
249 	bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
250 	spin_lock_bh(&bat_priv->forw_bat_list_lock);
251 	hlist_del(&forw_packet->list);
252 	spin_unlock_bh(&bat_priv->forw_bat_list_lock);
253 
254 	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
255 		goto out;
256 
257 	bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
258 
259 	/* we have to have at least one packet in the queue
260 	 * to determine the queues wake up time unless we are
261 	 * shutting down
262 	 */
263 	if (forw_packet->own)
264 		batadv_schedule_bat_ogm(forw_packet->if_incoming);
265 
266 out:
267 	/* don't count own packet */
268 	if (!forw_packet->own)
269 		atomic_inc(&bat_priv->batman_queue_left);
270 
271 	batadv_forw_packet_free(forw_packet);
272 }
273 
274 void
275 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
276 				 const struct batadv_hard_iface *hard_iface)
277 {
278 	struct batadv_forw_packet *forw_packet;
279 	struct hlist_node *tmp_node, *safe_tmp_node;
280 	bool pending;
281 
282 	if (hard_iface)
283 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
284 			   "purge_outstanding_packets(): %s\n",
285 			   hard_iface->net_dev->name);
286 	else
287 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
288 			   "purge_outstanding_packets()\n");
289 
290 	/* free bcast list */
291 	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
292 	hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
293 				  &bat_priv->forw_bcast_list, list) {
294 
295 		/* if purge_outstanding_packets() was called with an argument
296 		 * we delete only packets belonging to the given interface
297 		 */
298 		if ((hard_iface) &&
299 		    (forw_packet->if_incoming != hard_iface))
300 			continue;
301 
302 		spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
303 
304 		/* batadv_send_outstanding_bcast_packet() will lock the list to
305 		 * delete the item from the list
306 		 */
307 		pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
308 		spin_lock_bh(&bat_priv->forw_bcast_list_lock);
309 
310 		if (pending) {
311 			hlist_del(&forw_packet->list);
312 			batadv_forw_packet_free(forw_packet);
313 		}
314 	}
315 	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
316 
317 	/* free batman packet list */
318 	spin_lock_bh(&bat_priv->forw_bat_list_lock);
319 	hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
320 				  &bat_priv->forw_bat_list, list) {
321 
322 		/* if purge_outstanding_packets() was called with an argument
323 		 * we delete only packets belonging to the given interface
324 		 */
325 		if ((hard_iface) &&
326 		    (forw_packet->if_incoming != hard_iface))
327 			continue;
328 
329 		spin_unlock_bh(&bat_priv->forw_bat_list_lock);
330 
331 		/* send_outstanding_bat_packet() will lock the list to
332 		 * delete the item from the list
333 		 */
334 		pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
335 		spin_lock_bh(&bat_priv->forw_bat_list_lock);
336 
337 		if (pending) {
338 			hlist_del(&forw_packet->list);
339 			batadv_forw_packet_free(forw_packet);
340 		}
341 	}
342 	spin_unlock_bh(&bat_priv->forw_bat_list_lock);
343 }
344