net: fix potential neighbour race in dst_ifdown()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / batman-adv / send.c
blob58d14472068cf305b2280426613217008e6480fe
1 /*
2 * Copyright (C) 2007-2011 B.A.T.M.A.N. contributors:
4 * Marek Lindner, Simon Wunderlich
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of version 2 of the GNU General Public
8 * License as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18 * 02110-1301, USA
22 #include "main.h"
23 #include "send.h"
24 #include "routing.h"
25 #include "translation-table.h"
26 #include "soft-interface.h"
27 #include "hard-interface.h"
28 #include "vis.h"
29 #include "aggregation.h"
30 #include "gateway_common.h"
31 #include "originator.h"
33 static void send_outstanding_bcast_packet(struct work_struct *work);
35 /* apply hop penalty for a normal link */
36 static uint8_t hop_penalty(uint8_t tq, const struct bat_priv *bat_priv)
38 int hop_penalty = atomic_read(&bat_priv->hop_penalty);
39 return (tq * (TQ_MAX_VALUE - hop_penalty)) / (TQ_MAX_VALUE);
42 /* when do we schedule our own packet to be sent */
43 static unsigned long own_send_time(const struct bat_priv *bat_priv)
45 return jiffies + msecs_to_jiffies(
46 atomic_read(&bat_priv->orig_interval) -
47 JITTER + (random32() % 2*JITTER));
50 /* when do we schedule a forwarded packet to be sent */
51 static unsigned long forward_send_time(void)
53 return jiffies + msecs_to_jiffies(random32() % (JITTER/2));
56 /* send out an already prepared packet to the given address via the
57 * specified batman interface */
58 int send_skb_packet(struct sk_buff *skb, struct hard_iface *hard_iface,
59 const uint8_t *dst_addr)
61 struct ethhdr *ethhdr;
63 if (hard_iface->if_status != IF_ACTIVE)
64 goto send_skb_err;
66 if (unlikely(!hard_iface->net_dev))
67 goto send_skb_err;
69 if (!(hard_iface->net_dev->flags & IFF_UP)) {
70 pr_warning("Interface %s is not up - can't send packet via "
71 "that interface!\n", hard_iface->net_dev->name);
72 goto send_skb_err;
75 /* push to the ethernet header. */
76 if (my_skb_head_push(skb, sizeof(*ethhdr)) < 0)
77 goto send_skb_err;
79 skb_reset_mac_header(skb);
81 ethhdr = (struct ethhdr *) skb_mac_header(skb);
82 memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
83 memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
84 ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
86 skb_set_network_header(skb, ETH_HLEN);
87 skb->priority = TC_PRIO_CONTROL;
88 skb->protocol = __constant_htons(ETH_P_BATMAN);
90 skb->dev = hard_iface->net_dev;
92 /* dev_queue_xmit() returns a negative result on error. However on
93 * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
94 * (which is > 0). This will not be treated as an error. */
96 return dev_queue_xmit(skb);
97 send_skb_err:
98 kfree_skb(skb);
99 return NET_XMIT_DROP;
102 /* Send a packet to a given interface */
103 static void send_packet_to_if(struct forw_packet *forw_packet,
104 struct hard_iface *hard_iface)
106 struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
107 char *fwd_str;
108 uint8_t packet_num;
109 int16_t buff_pos;
110 struct batman_packet *batman_packet;
111 struct sk_buff *skb;
113 if (hard_iface->if_status != IF_ACTIVE)
114 return;
116 packet_num = 0;
117 buff_pos = 0;
118 batman_packet = (struct batman_packet *)forw_packet->skb->data;
120 /* adjust all flags and log packets */
121 while (aggregated_packet(buff_pos,
122 forw_packet->packet_len,
123 batman_packet->tt_num_changes)) {
125 /* we might have aggregated direct link packets with an
126 * ordinary base packet */
127 if ((forw_packet->direct_link_flags & (1 << packet_num)) &&
128 (forw_packet->if_incoming == hard_iface))
129 batman_packet->flags |= DIRECTLINK;
130 else
131 batman_packet->flags &= ~DIRECTLINK;
133 fwd_str = (packet_num > 0 ? "Forwarding" : (forw_packet->own ?
134 "Sending own" :
135 "Forwarding"));
136 bat_dbg(DBG_BATMAN, bat_priv,
137 "%s %spacket (originator %pM, seqno %d, TQ %d, TTL %d,"
138 " IDF %s, hvn %d) on interface %s [%pM]\n",
139 fwd_str, (packet_num > 0 ? "aggregated " : ""),
140 batman_packet->orig, ntohl(batman_packet->seqno),
141 batman_packet->tq, batman_packet->ttl,
142 (batman_packet->flags & DIRECTLINK ?
143 "on" : "off"),
144 batman_packet->ttvn, hard_iface->net_dev->name,
145 hard_iface->net_dev->dev_addr);
147 buff_pos += sizeof(*batman_packet) +
148 tt_len(batman_packet->tt_num_changes);
149 packet_num++;
150 batman_packet = (struct batman_packet *)
151 (forw_packet->skb->data + buff_pos);
154 /* create clone because function is called more than once */
155 skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
156 if (skb)
157 send_skb_packet(skb, hard_iface, broadcast_addr);
160 /* send a batman packet */
161 static void send_packet(struct forw_packet *forw_packet)
163 struct hard_iface *hard_iface;
164 struct net_device *soft_iface;
165 struct bat_priv *bat_priv;
166 struct hard_iface *primary_if = NULL;
167 struct batman_packet *batman_packet =
168 (struct batman_packet *)(forw_packet->skb->data);
169 int directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
171 if (!forw_packet->if_incoming) {
172 pr_err("Error - can't forward packet: incoming iface not "
173 "specified\n");
174 goto out;
177 soft_iface = forw_packet->if_incoming->soft_iface;
178 bat_priv = netdev_priv(soft_iface);
180 if (forw_packet->if_incoming->if_status != IF_ACTIVE)
181 goto out;
183 primary_if = primary_if_get_selected(bat_priv);
184 if (!primary_if)
185 goto out;
187 /* multihomed peer assumed */
188 /* non-primary OGMs are only broadcasted on their interface */
189 if ((directlink && (batman_packet->ttl == 1)) ||
190 (forw_packet->own && (forw_packet->if_incoming != primary_if))) {
192 /* FIXME: what about aggregated packets ? */
193 bat_dbg(DBG_BATMAN, bat_priv,
194 "%s packet (originator %pM, seqno %d, TTL %d) "
195 "on interface %s [%pM]\n",
196 (forw_packet->own ? "Sending own" : "Forwarding"),
197 batman_packet->orig, ntohl(batman_packet->seqno),
198 batman_packet->ttl,
199 forw_packet->if_incoming->net_dev->name,
200 forw_packet->if_incoming->net_dev->dev_addr);
202 /* skb is only used once and than forw_packet is free'd */
203 send_skb_packet(forw_packet->skb, forw_packet->if_incoming,
204 broadcast_addr);
205 forw_packet->skb = NULL;
207 goto out;
210 /* broadcast on every interface */
211 rcu_read_lock();
212 list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
213 if (hard_iface->soft_iface != soft_iface)
214 continue;
216 send_packet_to_if(forw_packet, hard_iface);
218 rcu_read_unlock();
220 out:
221 if (primary_if)
222 hardif_free_ref(primary_if);
225 static void realloc_packet_buffer(struct hard_iface *hard_iface,
226 int new_len)
228 unsigned char *new_buff;
229 struct batman_packet *batman_packet;
231 new_buff = kmalloc(new_len, GFP_ATOMIC);
233 /* keep old buffer if kmalloc should fail */
234 if (new_buff) {
235 memcpy(new_buff, hard_iface->packet_buff,
236 sizeof(*batman_packet));
238 kfree(hard_iface->packet_buff);
239 hard_iface->packet_buff = new_buff;
240 hard_iface->packet_len = new_len;
244 /* when calling this function (hard_iface == primary_if) has to be true */
245 static void prepare_packet_buffer(struct bat_priv *bat_priv,
246 struct hard_iface *hard_iface)
248 int new_len;
249 struct batman_packet *batman_packet;
251 new_len = BAT_PACKET_LEN +
252 tt_len((uint8_t)atomic_read(&bat_priv->tt_local_changes));
254 /* if we have too many changes for one packet don't send any
255 * and wait for the tt table request which will be fragmented */
256 if (new_len > hard_iface->soft_iface->mtu)
257 new_len = BAT_PACKET_LEN;
259 realloc_packet_buffer(hard_iface, new_len);
260 batman_packet = (struct batman_packet *)hard_iface->packet_buff;
262 atomic_set(&bat_priv->tt_crc, tt_local_crc(bat_priv));
264 /* reset the sending counter */
265 atomic_set(&bat_priv->tt_ogm_append_cnt, TT_OGM_APPEND_MAX);
267 batman_packet->tt_num_changes = tt_changes_fill_buffer(bat_priv,
268 hard_iface->packet_buff + BAT_PACKET_LEN,
269 hard_iface->packet_len - BAT_PACKET_LEN);
273 static void reset_packet_buffer(struct bat_priv *bat_priv,
274 struct hard_iface *hard_iface)
276 struct batman_packet *batman_packet;
278 realloc_packet_buffer(hard_iface, BAT_PACKET_LEN);
280 batman_packet = (struct batman_packet *)hard_iface->packet_buff;
281 batman_packet->tt_num_changes = 0;
284 void schedule_own_packet(struct hard_iface *hard_iface)
286 struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
287 struct hard_iface *primary_if;
288 unsigned long send_time;
289 struct batman_packet *batman_packet;
290 int vis_server;
292 if ((hard_iface->if_status == IF_NOT_IN_USE) ||
293 (hard_iface->if_status == IF_TO_BE_REMOVED))
294 return;
296 vis_server = atomic_read(&bat_priv->vis_mode);
297 primary_if = primary_if_get_selected(bat_priv);
300 * the interface gets activated here to avoid race conditions between
301 * the moment of activating the interface in
302 * hardif_activate_interface() where the originator mac is set and
303 * outdated packets (especially uninitialized mac addresses) in the
304 * packet queue
306 if (hard_iface->if_status == IF_TO_BE_ACTIVATED)
307 hard_iface->if_status = IF_ACTIVE;
309 if (hard_iface == primary_if) {
310 /* if at least one change happened */
311 if (atomic_read(&bat_priv->tt_local_changes) > 0) {
312 tt_commit_changes(bat_priv);
313 prepare_packet_buffer(bat_priv, hard_iface);
316 /* if the changes have been sent enough times */
317 if (!atomic_dec_not_zero(&bat_priv->tt_ogm_append_cnt))
318 reset_packet_buffer(bat_priv, hard_iface);
322 * NOTE: packet_buff might just have been re-allocated in
323 * prepare_packet_buffer() or in reset_packet_buffer()
325 batman_packet = (struct batman_packet *)hard_iface->packet_buff;
327 /* change sequence number to network order */
328 batman_packet->seqno =
329 htonl((uint32_t)atomic_read(&hard_iface->seqno));
331 batman_packet->ttvn = atomic_read(&bat_priv->ttvn);
332 batman_packet->tt_crc = htons((uint16_t)atomic_read(&bat_priv->tt_crc));
334 if (vis_server == VIS_TYPE_SERVER_SYNC)
335 batman_packet->flags |= VIS_SERVER;
336 else
337 batman_packet->flags &= ~VIS_SERVER;
339 if ((hard_iface == primary_if) &&
340 (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER))
341 batman_packet->gw_flags =
342 (uint8_t)atomic_read(&bat_priv->gw_bandwidth);
343 else
344 batman_packet->gw_flags = NO_FLAGS;
346 atomic_inc(&hard_iface->seqno);
348 slide_own_bcast_window(hard_iface);
349 send_time = own_send_time(bat_priv);
350 add_bat_packet_to_list(bat_priv,
351 hard_iface->packet_buff,
352 hard_iface->packet_len,
353 hard_iface, 1, send_time);
355 if (primary_if)
356 hardif_free_ref(primary_if);
359 void schedule_forward_packet(struct orig_node *orig_node,
360 const struct ethhdr *ethhdr,
361 struct batman_packet *batman_packet,
362 int directlink,
363 struct hard_iface *if_incoming)
365 struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
366 struct neigh_node *router;
367 uint8_t in_tq, in_ttl, tq_avg = 0;
368 unsigned long send_time;
369 uint8_t tt_num_changes;
371 if (batman_packet->ttl <= 1) {
372 bat_dbg(DBG_BATMAN, bat_priv, "ttl exceeded\n");
373 return;
376 router = orig_node_get_router(orig_node);
378 in_tq = batman_packet->tq;
379 in_ttl = batman_packet->ttl;
380 tt_num_changes = batman_packet->tt_num_changes;
382 batman_packet->ttl--;
383 memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
385 /* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
386 * of our best tq value */
387 if (router && router->tq_avg != 0) {
389 /* rebroadcast ogm of best ranking neighbor as is */
390 if (!compare_eth(router->addr, ethhdr->h_source)) {
391 batman_packet->tq = router->tq_avg;
393 if (router->last_ttl)
394 batman_packet->ttl = router->last_ttl - 1;
397 tq_avg = router->tq_avg;
400 if (router)
401 neigh_node_free_ref(router);
403 /* apply hop penalty */
404 batman_packet->tq = hop_penalty(batman_packet->tq, bat_priv);
406 bat_dbg(DBG_BATMAN, bat_priv,
407 "Forwarding packet: tq_orig: %i, tq_avg: %i, "
408 "tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
409 in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
410 batman_packet->ttl);
412 batman_packet->seqno = htonl(batman_packet->seqno);
413 batman_packet->tt_crc = htons(batman_packet->tt_crc);
415 /* switch of primaries first hop flag when forwarding */
416 batman_packet->flags &= ~PRIMARIES_FIRST_HOP;
417 if (directlink)
418 batman_packet->flags |= DIRECTLINK;
419 else
420 batman_packet->flags &= ~DIRECTLINK;
422 send_time = forward_send_time();
423 add_bat_packet_to_list(bat_priv,
424 (unsigned char *)batman_packet,
425 sizeof(*batman_packet) + tt_len(tt_num_changes),
426 if_incoming, 0, send_time);
429 static void forw_packet_free(struct forw_packet *forw_packet)
431 if (forw_packet->skb)
432 kfree_skb(forw_packet->skb);
433 if (forw_packet->if_incoming)
434 hardif_free_ref(forw_packet->if_incoming);
435 kfree(forw_packet);
438 static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
439 struct forw_packet *forw_packet,
440 unsigned long send_time)
442 INIT_HLIST_NODE(&forw_packet->list);
444 /* add new packet to packet list */
445 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
446 hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
447 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
449 /* start timer for this packet */
450 INIT_DELAYED_WORK(&forw_packet->delayed_work,
451 send_outstanding_bcast_packet);
452 queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
453 send_time);
456 /* add a broadcast packet to the queue and setup timers. broadcast packets
457 * are sent multiple times to increase probability for beeing received.
459 * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
460 * errors.
462 * The skb is not consumed, so the caller should make sure that the
463 * skb is freed. */
464 int add_bcast_packet_to_list(struct bat_priv *bat_priv,
465 const struct sk_buff *skb, unsigned long delay)
467 struct hard_iface *primary_if = NULL;
468 struct forw_packet *forw_packet;
469 struct bcast_packet *bcast_packet;
470 struct sk_buff *newskb;
472 if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
473 bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
474 goto out;
477 primary_if = primary_if_get_selected(bat_priv);
478 if (!primary_if)
479 goto out_and_inc;
481 forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
483 if (!forw_packet)
484 goto out_and_inc;
486 newskb = skb_copy(skb, GFP_ATOMIC);
487 if (!newskb)
488 goto packet_free;
490 /* as we have a copy now, it is safe to decrease the TTL */
491 bcast_packet = (struct bcast_packet *)newskb->data;
492 bcast_packet->ttl--;
494 skb_reset_mac_header(newskb);
496 forw_packet->skb = newskb;
497 forw_packet->if_incoming = primary_if;
499 /* how often did we send the bcast packet ? */
500 forw_packet->num_packets = 0;
502 _add_bcast_packet_to_list(bat_priv, forw_packet, delay);
503 return NETDEV_TX_OK;
505 packet_free:
506 kfree(forw_packet);
507 out_and_inc:
508 atomic_inc(&bat_priv->bcast_queue_left);
509 out:
510 if (primary_if)
511 hardif_free_ref(primary_if);
512 return NETDEV_TX_BUSY;
515 static void send_outstanding_bcast_packet(struct work_struct *work)
517 struct hard_iface *hard_iface;
518 struct delayed_work *delayed_work =
519 container_of(work, struct delayed_work, work);
520 struct forw_packet *forw_packet =
521 container_of(delayed_work, struct forw_packet, delayed_work);
522 struct sk_buff *skb1;
523 struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
524 struct bat_priv *bat_priv = netdev_priv(soft_iface);
526 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
527 hlist_del(&forw_packet->list);
528 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
530 if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
531 goto out;
533 /* rebroadcast packet */
534 rcu_read_lock();
535 list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
536 if (hard_iface->soft_iface != soft_iface)
537 continue;
539 /* send a copy of the saved skb */
540 skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
541 if (skb1)
542 send_skb_packet(skb1, hard_iface, broadcast_addr);
544 rcu_read_unlock();
546 forw_packet->num_packets++;
548 /* if we still have some more bcasts to send */
549 if (forw_packet->num_packets < 3) {
550 _add_bcast_packet_to_list(bat_priv, forw_packet,
551 ((5 * HZ) / 1000));
552 return;
555 out:
556 forw_packet_free(forw_packet);
557 atomic_inc(&bat_priv->bcast_queue_left);
560 void send_outstanding_bat_packet(struct work_struct *work)
562 struct delayed_work *delayed_work =
563 container_of(work, struct delayed_work, work);
564 struct forw_packet *forw_packet =
565 container_of(delayed_work, struct forw_packet, delayed_work);
566 struct bat_priv *bat_priv;
568 bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
569 spin_lock_bh(&bat_priv->forw_bat_list_lock);
570 hlist_del(&forw_packet->list);
571 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
573 if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
574 goto out;
576 send_packet(forw_packet);
579 * we have to have at least one packet in the queue
580 * to determine the queues wake up time unless we are
581 * shutting down
583 if (forw_packet->own)
584 schedule_own_packet(forw_packet->if_incoming);
586 out:
587 /* don't count own packet */
588 if (!forw_packet->own)
589 atomic_inc(&bat_priv->batman_queue_left);
591 forw_packet_free(forw_packet);
594 void purge_outstanding_packets(struct bat_priv *bat_priv,
595 const struct hard_iface *hard_iface)
597 struct forw_packet *forw_packet;
598 struct hlist_node *tmp_node, *safe_tmp_node;
599 bool pending;
601 if (hard_iface)
602 bat_dbg(DBG_BATMAN, bat_priv,
603 "purge_outstanding_packets(): %s\n",
604 hard_iface->net_dev->name);
605 else
606 bat_dbg(DBG_BATMAN, bat_priv,
607 "purge_outstanding_packets()\n");
609 /* free bcast list */
610 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
611 hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
612 &bat_priv->forw_bcast_list, list) {
615 * if purge_outstanding_packets() was called with an argmument
616 * we delete only packets belonging to the given interface
618 if ((hard_iface) &&
619 (forw_packet->if_incoming != hard_iface))
620 continue;
622 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
625 * send_outstanding_bcast_packet() will lock the list to
626 * delete the item from the list
628 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
629 spin_lock_bh(&bat_priv->forw_bcast_list_lock);
631 if (pending) {
632 hlist_del(&forw_packet->list);
633 forw_packet_free(forw_packet);
636 spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
638 /* free batman packet list */
639 spin_lock_bh(&bat_priv->forw_bat_list_lock);
640 hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
641 &bat_priv->forw_bat_list, list) {
644 * if purge_outstanding_packets() was called with an argmument
645 * we delete only packets belonging to the given interface
647 if ((hard_iface) &&
648 (forw_packet->if_incoming != hard_iface))
649 continue;
651 spin_unlock_bh(&bat_priv->forw_bat_list_lock);
654 * send_outstanding_bat_packet() will lock the list to
655 * delete the item from the list
657 pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
658 spin_lock_bh(&bat_priv->forw_bat_list_lock);
660 if (pending) {
661 hlist_del(&forw_packet->list);
662 forw_packet_free(forw_packet);
665 spin_unlock_bh(&bat_priv->forw_bat_list_lock);