1 /* Copyright (C) 2009-2013 B.A.T.M.A.N. contributors:
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.
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.
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
22 #include "gateway_client.h"
23 #include "gateway_common.h"
24 #include "hard-interface.h"
25 #include "originator.h"
26 #include "translation-table.h"
29 #include <linux/ipv6.h>
30 #include <linux/udp.h>
31 #include <linux/if_vlan.h>
33 /* This is the offset of the options field in a dhcp packet starting at
34 * the beginning of the dhcp header
36 #define BATADV_DHCP_OPTIONS_OFFSET 240
37 #define BATADV_DHCP_REQUEST 3
39 static void batadv_gw_node_free_ref(struct batadv_gw_node
*gw_node
)
41 if (atomic_dec_and_test(&gw_node
->refcount
))
42 kfree_rcu(gw_node
, rcu
);
45 static struct batadv_gw_node
*
46 batadv_gw_get_selected_gw_node(struct batadv_priv
*bat_priv
)
48 struct batadv_gw_node
*gw_node
;
51 gw_node
= rcu_dereference(bat_priv
->gw
.curr_gw
);
55 if (!atomic_inc_not_zero(&gw_node
->refcount
))
63 struct batadv_orig_node
*
64 batadv_gw_get_selected_orig(struct batadv_priv
*bat_priv
)
66 struct batadv_gw_node
*gw_node
;
67 struct batadv_orig_node
*orig_node
= NULL
;
69 gw_node
= batadv_gw_get_selected_gw_node(bat_priv
);
74 orig_node
= gw_node
->orig_node
;
78 if (!atomic_inc_not_zero(&orig_node
->refcount
))
85 batadv_gw_node_free_ref(gw_node
);
89 static void batadv_gw_select(struct batadv_priv
*bat_priv
,
90 struct batadv_gw_node
*new_gw_node
)
92 struct batadv_gw_node
*curr_gw_node
;
94 spin_lock_bh(&bat_priv
->gw
.list_lock
);
96 if (new_gw_node
&& !atomic_inc_not_zero(&new_gw_node
->refcount
))
99 curr_gw_node
= rcu_dereference_protected(bat_priv
->gw
.curr_gw
, 1);
100 rcu_assign_pointer(bat_priv
->gw
.curr_gw
, new_gw_node
);
103 batadv_gw_node_free_ref(curr_gw_node
);
105 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
108 void batadv_gw_deselect(struct batadv_priv
*bat_priv
)
110 atomic_set(&bat_priv
->gw
.reselect
, 1);
113 static struct batadv_gw_node
*
114 batadv_gw_get_best_gw_node(struct batadv_priv
*bat_priv
)
116 struct batadv_neigh_node
*router
;
117 struct batadv_gw_node
*gw_node
, *curr_gw
= NULL
;
118 uint32_t max_gw_factor
= 0, tmp_gw_factor
= 0;
123 struct batadv_orig_node
*orig_node
;
125 gw_divisor
= BATADV_TQ_LOCAL_WINDOW_SIZE
* BATADV_TQ_LOCAL_WINDOW_SIZE
;
129 hlist_for_each_entry_rcu(gw_node
, &bat_priv
->gw
.list
, list
) {
130 if (gw_node
->deleted
)
133 orig_node
= gw_node
->orig_node
;
134 router
= batadv_orig_node_get_router(orig_node
);
138 if (!atomic_inc_not_zero(&gw_node
->refcount
))
141 tq_avg
= router
->tq_avg
;
143 switch (atomic_read(&bat_priv
->gw_sel_class
)) {
144 case 1: /* fast connection */
145 batadv_gw_bandwidth_to_kbit(orig_node
->gw_flags
,
148 tmp_gw_factor
= tq_avg
* tq_avg
* down
* 100 * 100;
149 tmp_gw_factor
/= gw_divisor
;
151 if ((tmp_gw_factor
> max_gw_factor
) ||
152 ((tmp_gw_factor
== max_gw_factor
) &&
153 (tq_avg
> max_tq
))) {
155 batadv_gw_node_free_ref(curr_gw
);
157 atomic_inc(&curr_gw
->refcount
);
161 default: /* 2: stable connection (use best statistic)
162 * 3: fast-switch (use best statistic but change as
163 * soon as a better gateway appears)
164 * XX: late-switch (use best statistic but change as
165 * soon as a better gateway appears which has
166 * $routing_class more tq points)
168 if (tq_avg
> max_tq
) {
170 batadv_gw_node_free_ref(curr_gw
);
172 atomic_inc(&curr_gw
->refcount
);
180 if (tmp_gw_factor
> max_gw_factor
)
181 max_gw_factor
= tmp_gw_factor
;
183 batadv_gw_node_free_ref(gw_node
);
186 batadv_neigh_node_free_ref(router
);
194 * batadv_gw_check_client_stop - check if client mode has been switched off
195 * @bat_priv: the bat priv with all the soft interface information
197 * This function assumes the caller has checked that the gw state *is actually
198 * changing*. This function is not supposed to be called when there is no state
201 void batadv_gw_check_client_stop(struct batadv_priv
*bat_priv
)
203 struct batadv_gw_node
*curr_gw
;
205 if (atomic_read(&bat_priv
->gw_mode
) != BATADV_GW_MODE_CLIENT
)
208 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
212 /* if batman-adv is switching the gw client mode off and a gateway was
213 * already selected, send a DEL uevent
215 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_DEL
, NULL
);
217 batadv_gw_node_free_ref(curr_gw
);
220 void batadv_gw_election(struct batadv_priv
*bat_priv
)
222 struct batadv_gw_node
*curr_gw
= NULL
, *next_gw
= NULL
;
223 struct batadv_neigh_node
*router
= NULL
;
224 char gw_addr
[18] = { '\0' };
226 /* The batman daemon checks here if we already passed a full originator
227 * cycle in order to make sure we don't choose the first gateway we
228 * hear about. This check is based on the daemon's uptime which we
231 if (atomic_read(&bat_priv
->gw_mode
) != BATADV_GW_MODE_CLIENT
)
234 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
236 if (!batadv_atomic_dec_not_zero(&bat_priv
->gw
.reselect
) && curr_gw
)
239 next_gw
= batadv_gw_get_best_gw_node(bat_priv
);
241 if (curr_gw
== next_gw
)
245 sprintf(gw_addr
, "%pM", next_gw
->orig_node
->orig
);
247 router
= batadv_orig_node_get_router(next_gw
->orig_node
);
249 batadv_gw_deselect(bat_priv
);
254 if ((curr_gw
) && (!next_gw
)) {
255 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
256 "Removing selected gateway - no gateway in range\n");
257 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_DEL
,
259 } else if ((!curr_gw
) && (next_gw
)) {
260 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
261 "Adding route to gateway %pM (gw_flags: %i, tq: %i)\n",
262 next_gw
->orig_node
->orig
,
263 next_gw
->orig_node
->gw_flags
, router
->tq_avg
);
264 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_ADD
,
267 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
268 "Changing route to gateway %pM (gw_flags: %i, tq: %i)\n",
269 next_gw
->orig_node
->orig
,
270 next_gw
->orig_node
->gw_flags
, router
->tq_avg
);
271 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_CHANGE
,
275 batadv_gw_select(bat_priv
, next_gw
);
279 batadv_gw_node_free_ref(curr_gw
);
281 batadv_gw_node_free_ref(next_gw
);
283 batadv_neigh_node_free_ref(router
);
286 void batadv_gw_check_election(struct batadv_priv
*bat_priv
,
287 struct batadv_orig_node
*orig_node
)
289 struct batadv_orig_node
*curr_gw_orig
;
290 struct batadv_neigh_node
*router_gw
= NULL
, *router_orig
= NULL
;
291 uint8_t gw_tq_avg
, orig_tq_avg
;
293 curr_gw_orig
= batadv_gw_get_selected_orig(bat_priv
);
297 router_gw
= batadv_orig_node_get_router(curr_gw_orig
);
301 /* this node already is the gateway */
302 if (curr_gw_orig
== orig_node
)
305 router_orig
= batadv_orig_node_get_router(orig_node
);
309 gw_tq_avg
= router_gw
->tq_avg
;
310 orig_tq_avg
= router_orig
->tq_avg
;
312 /* the TQ value has to be better */
313 if (orig_tq_avg
< gw_tq_avg
)
316 /* if the routing class is greater than 3 the value tells us how much
317 * greater the TQ value of the new gateway must be
319 if ((atomic_read(&bat_priv
->gw_sel_class
) > 3) &&
320 (orig_tq_avg
- gw_tq_avg
< atomic_read(&bat_priv
->gw_sel_class
)))
323 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
324 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
325 gw_tq_avg
, orig_tq_avg
);
328 batadv_gw_deselect(bat_priv
);
331 batadv_orig_node_free_ref(curr_gw_orig
);
333 batadv_neigh_node_free_ref(router_gw
);
335 batadv_neigh_node_free_ref(router_orig
);
340 static void batadv_gw_node_add(struct batadv_priv
*bat_priv
,
341 struct batadv_orig_node
*orig_node
,
344 struct batadv_gw_node
*gw_node
;
347 gw_node
= kzalloc(sizeof(*gw_node
), GFP_ATOMIC
);
351 INIT_HLIST_NODE(&gw_node
->list
);
352 gw_node
->orig_node
= orig_node
;
353 atomic_set(&gw_node
->refcount
, 1);
355 spin_lock_bh(&bat_priv
->gw
.list_lock
);
356 hlist_add_head_rcu(&gw_node
->list
, &bat_priv
->gw
.list
);
357 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
359 batadv_gw_bandwidth_to_kbit(new_gwflags
, &down
, &up
);
360 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
361 "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
362 orig_node
->orig
, new_gwflags
,
363 (down
> 2048 ? down
/ 1024 : down
),
364 (down
> 2048 ? "MBit" : "KBit"),
365 (up
> 2048 ? up
/ 1024 : up
),
366 (up
> 2048 ? "MBit" : "KBit"));
369 void batadv_gw_node_update(struct batadv_priv
*bat_priv
,
370 struct batadv_orig_node
*orig_node
,
373 struct batadv_gw_node
*gw_node
, *curr_gw
;
375 /* Note: We don't need a NULL check here, since curr_gw never gets
376 * dereferenced. If curr_gw is NULL we also should not exit as we may
377 * have this gateway in our list (duplication check!) even though we
378 * have no currently selected gateway.
380 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
383 hlist_for_each_entry_rcu(gw_node
, &bat_priv
->gw
.list
, list
) {
384 if (gw_node
->orig_node
!= orig_node
)
387 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
388 "Gateway class of originator %pM changed from %i to %i\n",
389 orig_node
->orig
, gw_node
->orig_node
->gw_flags
,
392 gw_node
->deleted
= 0;
394 if (new_gwflags
== BATADV_NO_FLAGS
) {
395 gw_node
->deleted
= jiffies
;
396 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
397 "Gateway %pM removed from gateway list\n",
400 if (gw_node
== curr_gw
)
407 if (new_gwflags
== BATADV_NO_FLAGS
)
410 batadv_gw_node_add(bat_priv
, orig_node
, new_gwflags
);
414 batadv_gw_deselect(bat_priv
);
419 batadv_gw_node_free_ref(curr_gw
);
422 void batadv_gw_node_delete(struct batadv_priv
*bat_priv
,
423 struct batadv_orig_node
*orig_node
)
425 batadv_gw_node_update(bat_priv
, orig_node
, 0);
428 void batadv_gw_node_purge(struct batadv_priv
*bat_priv
)
430 struct batadv_gw_node
*gw_node
, *curr_gw
;
431 struct hlist_node
*node_tmp
;
432 unsigned long timeout
= msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT
);
435 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
437 spin_lock_bh(&bat_priv
->gw
.list_lock
);
439 hlist_for_each_entry_safe(gw_node
, node_tmp
,
440 &bat_priv
->gw
.list
, list
) {
441 if (((!gw_node
->deleted
) ||
442 (time_before(jiffies
, gw_node
->deleted
+ timeout
))) &&
443 atomic_read(&bat_priv
->mesh_state
) == BATADV_MESH_ACTIVE
)
446 if (curr_gw
== gw_node
)
449 hlist_del_rcu(&gw_node
->list
);
450 batadv_gw_node_free_ref(gw_node
);
453 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
455 /* gw_deselect() needs to acquire the gw_list_lock */
457 batadv_gw_deselect(bat_priv
);
460 batadv_gw_node_free_ref(curr_gw
);
463 /* fails if orig_node has no router */
464 static int batadv_write_buffer_text(struct batadv_priv
*bat_priv
,
465 struct seq_file
*seq
,
466 const struct batadv_gw_node
*gw_node
)
468 struct batadv_gw_node
*curr_gw
;
469 struct batadv_neigh_node
*router
;
470 int down
, up
, ret
= -1;
472 batadv_gw_bandwidth_to_kbit(gw_node
->orig_node
->gw_flags
, &down
, &up
);
474 router
= batadv_orig_node_get_router(gw_node
->orig_node
);
478 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
480 ret
= seq_printf(seq
, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
481 (curr_gw
== gw_node
? "=>" : " "),
482 gw_node
->orig_node
->orig
,
483 router
->tq_avg
, router
->addr
,
484 router
->if_incoming
->net_dev
->name
,
485 gw_node
->orig_node
->gw_flags
,
486 (down
> 2048 ? down
/ 1024 : down
),
487 (down
> 2048 ? "MBit" : "KBit"),
488 (up
> 2048 ? up
/ 1024 : up
),
489 (up
> 2048 ? "MBit" : "KBit"));
491 batadv_neigh_node_free_ref(router
);
493 batadv_gw_node_free_ref(curr_gw
);
498 int batadv_gw_client_seq_print_text(struct seq_file
*seq
, void *offset
)
500 struct net_device
*net_dev
= (struct net_device
*)seq
->private;
501 struct batadv_priv
*bat_priv
= netdev_priv(net_dev
);
502 struct batadv_hard_iface
*primary_if
;
503 struct batadv_gw_node
*gw_node
;
506 primary_if
= batadv_seq_print_text_primary_if_get(seq
);
511 " %-12s (%s/%i) %17s [%10s]: gw_class ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
512 "Gateway", "#", BATADV_TQ_MAX_VALUE
, "Nexthop", "outgoingIF",
513 BATADV_SOURCE_VERSION
, primary_if
->net_dev
->name
,
514 primary_if
->net_dev
->dev_addr
, net_dev
->name
);
517 hlist_for_each_entry_rcu(gw_node
, &bat_priv
->gw
.list
, list
) {
518 if (gw_node
->deleted
)
521 /* fails if orig_node has no router */
522 if (batadv_write_buffer_text(bat_priv
, seq
, gw_node
) < 0)
530 seq_puts(seq
, "No gateways in range ...\n");
534 batadv_hardif_free_ref(primary_if
);
538 /* this call might reallocate skb data */
539 static bool batadv_is_type_dhcprequest(struct sk_buff
*skb
, int header_len
)
545 if (skb_linearize(skb
) < 0)
548 pkt_len
= skb_headlen(skb
);
550 if (pkt_len
< header_len
+ BATADV_DHCP_OPTIONS_OFFSET
+ 1)
553 p
= skb
->data
+ header_len
+ BATADV_DHCP_OPTIONS_OFFSET
;
554 pkt_len
-= header_len
+ BATADV_DHCP_OPTIONS_OFFSET
+ 1;
556 /* Access the dhcp option lists. Each entry is made up by:
557 * - octet 1: option type
558 * - octet 2: option data len (only if type != 255 and 0)
559 * - octet 3: option data
561 while (*p
!= 255 && !ret
) {
562 /* p now points to the first octet: option type */
564 /* type 53 is the message type option.
565 * Jump the len octet and go to the data octet
571 /* check if the message type is what we need */
572 if (*p
== BATADV_DHCP_REQUEST
)
575 } else if (*p
== 0) {
576 /* option type 0 (padding), just go forward */
582 /* This is any other option. So we get the length... */
588 /* ...and then we jump over the data */
589 if (pkt_len
< 1 + (*p
))
599 /* this call might reallocate skb data */
600 bool batadv_gw_is_dhcp_target(struct sk_buff
*skb
, unsigned int *header_len
)
602 struct ethhdr
*ethhdr
;
604 struct ipv6hdr
*ipv6hdr
;
605 struct udphdr
*udphdr
;
607 /* check for ethernet header */
608 if (!pskb_may_pull(skb
, *header_len
+ ETH_HLEN
))
610 ethhdr
= (struct ethhdr
*)skb
->data
;
611 *header_len
+= ETH_HLEN
;
613 /* check for initial vlan header */
614 if (ntohs(ethhdr
->h_proto
) == ETH_P_8021Q
) {
615 if (!pskb_may_pull(skb
, *header_len
+ VLAN_HLEN
))
617 ethhdr
= (struct ethhdr
*)(skb
->data
+ VLAN_HLEN
);
618 *header_len
+= VLAN_HLEN
;
621 /* check for ip header */
622 switch (ntohs(ethhdr
->h_proto
)) {
624 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*iphdr
)))
626 iphdr
= (struct iphdr
*)(skb
->data
+ *header_len
);
627 *header_len
+= iphdr
->ihl
* 4;
629 /* check for udp header */
630 if (iphdr
->protocol
!= IPPROTO_UDP
)
635 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*ipv6hdr
)))
637 ipv6hdr
= (struct ipv6hdr
*)(skb
->data
+ *header_len
);
638 *header_len
+= sizeof(*ipv6hdr
);
640 /* check for udp header */
641 if (ipv6hdr
->nexthdr
!= IPPROTO_UDP
)
649 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*udphdr
)))
652 /* skb->data might have been reallocated by pskb_may_pull() */
653 ethhdr
= (struct ethhdr
*)skb
->data
;
654 if (ntohs(ethhdr
->h_proto
) == ETH_P_8021Q
)
655 ethhdr
= (struct ethhdr
*)(skb
->data
+ VLAN_HLEN
);
657 udphdr
= (struct udphdr
*)(skb
->data
+ *header_len
);
658 *header_len
+= sizeof(*udphdr
);
660 /* check for bootp port */
661 if ((ntohs(ethhdr
->h_proto
) == ETH_P_IP
) &&
662 (ntohs(udphdr
->dest
) != 67))
665 if ((ntohs(ethhdr
->h_proto
) == ETH_P_IPV6
) &&
666 (ntohs(udphdr
->dest
) != 547))
672 /* this call might reallocate skb data */
673 bool batadv_gw_out_of_range(struct batadv_priv
*bat_priv
,
676 struct batadv_neigh_node
*neigh_curr
= NULL
, *neigh_old
= NULL
;
677 struct batadv_orig_node
*orig_dst_node
= NULL
;
678 struct batadv_gw_node
*curr_gw
= NULL
;
679 struct ethhdr
*ethhdr
;
680 bool ret
, out_of_range
= false;
681 unsigned int header_len
= 0;
684 ret
= batadv_gw_is_dhcp_target(skb
, &header_len
);
688 ethhdr
= (struct ethhdr
*)skb
->data
;
689 orig_dst_node
= batadv_transtable_search(bat_priv
, ethhdr
->h_source
,
694 if (!orig_dst_node
->gw_flags
)
697 ret
= batadv_is_type_dhcprequest(skb
, header_len
);
701 switch (atomic_read(&bat_priv
->gw_mode
)) {
702 case BATADV_GW_MODE_SERVER
:
703 /* If we are a GW then we are our best GW. We can artificially
704 * set the tq towards ourself as the maximum value
706 curr_tq_avg
= BATADV_TQ_MAX_VALUE
;
708 case BATADV_GW_MODE_CLIENT
:
709 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
713 /* packet is going to our gateway */
714 if (curr_gw
->orig_node
== orig_dst_node
)
717 /* If the dhcp packet has been sent to a different gw,
718 * we have to evaluate whether the old gw is still
721 neigh_curr
= batadv_find_router(bat_priv
, curr_gw
->orig_node
,
726 curr_tq_avg
= neigh_curr
->tq_avg
;
728 case BATADV_GW_MODE_OFF
:
733 neigh_old
= batadv_find_router(bat_priv
, orig_dst_node
, NULL
);
737 if (curr_tq_avg
- neigh_old
->tq_avg
> BATADV_GW_THRESHOLD
)
742 batadv_orig_node_free_ref(orig_dst_node
);
744 batadv_gw_node_free_ref(curr_gw
);
746 batadv_neigh_node_free_ref(neigh_old
);
748 batadv_neigh_node_free_ref(neigh_curr
);