1 /* Copyright (C) 2009-2012 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 hlist_node
*node
;
118 struct batadv_gw_node
*gw_node
, *curr_gw
= NULL
;
119 uint32_t max_gw_factor
= 0, tmp_gw_factor
= 0;
124 struct batadv_orig_node
*orig_node
;
126 gw_divisor
= BATADV_TQ_LOCAL_WINDOW_SIZE
* BATADV_TQ_LOCAL_WINDOW_SIZE
;
130 hlist_for_each_entry_rcu(gw_node
, node
, &bat_priv
->gw
.list
, list
) {
131 if (gw_node
->deleted
)
134 orig_node
= gw_node
->orig_node
;
135 router
= batadv_orig_node_get_router(orig_node
);
139 if (!atomic_inc_not_zero(&gw_node
->refcount
))
142 tq_avg
= router
->tq_avg
;
144 switch (atomic_read(&bat_priv
->gw_sel_class
)) {
145 case 1: /* fast connection */
146 batadv_gw_bandwidth_to_kbit(orig_node
->gw_flags
,
149 tmp_gw_factor
= tq_avg
* tq_avg
* down
* 100 * 100;
150 tmp_gw_factor
/= gw_divisor
;
152 if ((tmp_gw_factor
> max_gw_factor
) ||
153 ((tmp_gw_factor
== max_gw_factor
) &&
154 (tq_avg
> max_tq
))) {
156 batadv_gw_node_free_ref(curr_gw
);
158 atomic_inc(&curr_gw
->refcount
);
162 default: /* 2: stable connection (use best statistic)
163 * 3: fast-switch (use best statistic but change as
164 * soon as a better gateway appears)
165 * XX: late-switch (use best statistic but change as
166 * soon as a better gateway appears which has
167 * $routing_class more tq points)
169 if (tq_avg
> max_tq
) {
171 batadv_gw_node_free_ref(curr_gw
);
173 atomic_inc(&curr_gw
->refcount
);
181 if (tmp_gw_factor
> max_gw_factor
)
182 max_gw_factor
= tmp_gw_factor
;
184 batadv_gw_node_free_ref(gw_node
);
187 batadv_neigh_node_free_ref(router
);
194 void batadv_gw_election(struct batadv_priv
*bat_priv
)
196 struct batadv_gw_node
*curr_gw
= NULL
, *next_gw
= NULL
;
197 struct batadv_neigh_node
*router
= NULL
;
198 char gw_addr
[18] = { '\0' };
200 /* The batman daemon checks here if we already passed a full originator
201 * cycle in order to make sure we don't choose the first gateway we
202 * hear about. This check is based on the daemon's uptime which we
205 if (atomic_read(&bat_priv
->gw_mode
) != BATADV_GW_MODE_CLIENT
)
208 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
210 if (!batadv_atomic_dec_not_zero(&bat_priv
->gw
.reselect
) && curr_gw
)
213 next_gw
= batadv_gw_get_best_gw_node(bat_priv
);
215 if (curr_gw
== next_gw
)
219 sprintf(gw_addr
, "%pM", next_gw
->orig_node
->orig
);
221 router
= batadv_orig_node_get_router(next_gw
->orig_node
);
223 batadv_gw_deselect(bat_priv
);
228 if ((curr_gw
) && (!next_gw
)) {
229 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
230 "Removing selected gateway - no gateway in range\n");
231 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_DEL
,
233 } else if ((!curr_gw
) && (next_gw
)) {
234 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
235 "Adding route to gateway %pM (gw_flags: %i, tq: %i)\n",
236 next_gw
->orig_node
->orig
,
237 next_gw
->orig_node
->gw_flags
, router
->tq_avg
);
238 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_ADD
,
241 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
242 "Changing route to gateway %pM (gw_flags: %i, tq: %i)\n",
243 next_gw
->orig_node
->orig
,
244 next_gw
->orig_node
->gw_flags
, router
->tq_avg
);
245 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_CHANGE
,
249 batadv_gw_select(bat_priv
, next_gw
);
253 batadv_gw_node_free_ref(curr_gw
);
255 batadv_gw_node_free_ref(next_gw
);
257 batadv_neigh_node_free_ref(router
);
260 void batadv_gw_check_election(struct batadv_priv
*bat_priv
,
261 struct batadv_orig_node
*orig_node
)
263 struct batadv_orig_node
*curr_gw_orig
;
264 struct batadv_neigh_node
*router_gw
= NULL
, *router_orig
= NULL
;
265 uint8_t gw_tq_avg
, orig_tq_avg
;
267 curr_gw_orig
= batadv_gw_get_selected_orig(bat_priv
);
271 router_gw
= batadv_orig_node_get_router(curr_gw_orig
);
275 /* this node already is the gateway */
276 if (curr_gw_orig
== orig_node
)
279 router_orig
= batadv_orig_node_get_router(orig_node
);
283 gw_tq_avg
= router_gw
->tq_avg
;
284 orig_tq_avg
= router_orig
->tq_avg
;
286 /* the TQ value has to be better */
287 if (orig_tq_avg
< gw_tq_avg
)
290 /* if the routing class is greater than 3 the value tells us how much
291 * greater the TQ value of the new gateway must be
293 if ((atomic_read(&bat_priv
->gw_sel_class
) > 3) &&
294 (orig_tq_avg
- gw_tq_avg
< atomic_read(&bat_priv
->gw_sel_class
)))
297 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
298 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
299 gw_tq_avg
, orig_tq_avg
);
302 batadv_gw_deselect(bat_priv
);
305 batadv_orig_node_free_ref(curr_gw_orig
);
307 batadv_neigh_node_free_ref(router_gw
);
309 batadv_neigh_node_free_ref(router_orig
);
314 static void batadv_gw_node_add(struct batadv_priv
*bat_priv
,
315 struct batadv_orig_node
*orig_node
,
318 struct batadv_gw_node
*gw_node
;
321 gw_node
= kzalloc(sizeof(*gw_node
), GFP_ATOMIC
);
325 INIT_HLIST_NODE(&gw_node
->list
);
326 gw_node
->orig_node
= orig_node
;
327 atomic_set(&gw_node
->refcount
, 1);
329 spin_lock_bh(&bat_priv
->gw
.list_lock
);
330 hlist_add_head_rcu(&gw_node
->list
, &bat_priv
->gw
.list
);
331 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
333 batadv_gw_bandwidth_to_kbit(new_gwflags
, &down
, &up
);
334 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
335 "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
336 orig_node
->orig
, new_gwflags
,
337 (down
> 2048 ? down
/ 1024 : down
),
338 (down
> 2048 ? "MBit" : "KBit"),
339 (up
> 2048 ? up
/ 1024 : up
),
340 (up
> 2048 ? "MBit" : "KBit"));
343 void batadv_gw_node_update(struct batadv_priv
*bat_priv
,
344 struct batadv_orig_node
*orig_node
,
347 struct hlist_node
*node
;
348 struct batadv_gw_node
*gw_node
, *curr_gw
;
350 /* Note: We don't need a NULL check here, since curr_gw never gets
351 * dereferenced. If curr_gw is NULL we also should not exit as we may
352 * have this gateway in our list (duplication check!) even though we
353 * have no currently selected gateway.
355 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
358 hlist_for_each_entry_rcu(gw_node
, node
, &bat_priv
->gw
.list
, list
) {
359 if (gw_node
->orig_node
!= orig_node
)
362 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
363 "Gateway class of originator %pM changed from %i to %i\n",
364 orig_node
->orig
, gw_node
->orig_node
->gw_flags
,
367 gw_node
->deleted
= 0;
369 if (new_gwflags
== BATADV_NO_FLAGS
) {
370 gw_node
->deleted
= jiffies
;
371 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
372 "Gateway %pM removed from gateway list\n",
375 if (gw_node
== curr_gw
)
382 if (new_gwflags
== BATADV_NO_FLAGS
)
385 batadv_gw_node_add(bat_priv
, orig_node
, new_gwflags
);
389 batadv_gw_deselect(bat_priv
);
394 batadv_gw_node_free_ref(curr_gw
);
397 void batadv_gw_node_delete(struct batadv_priv
*bat_priv
,
398 struct batadv_orig_node
*orig_node
)
400 batadv_gw_node_update(bat_priv
, orig_node
, 0);
403 void batadv_gw_node_purge(struct batadv_priv
*bat_priv
)
405 struct batadv_gw_node
*gw_node
, *curr_gw
;
406 struct hlist_node
*node
, *node_tmp
;
407 unsigned long timeout
= msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT
);
410 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
412 spin_lock_bh(&bat_priv
->gw
.list_lock
);
414 hlist_for_each_entry_safe(gw_node
, node
, node_tmp
,
415 &bat_priv
->gw
.list
, list
) {
416 if (((!gw_node
->deleted
) ||
417 (time_before(jiffies
, gw_node
->deleted
+ timeout
))) &&
418 atomic_read(&bat_priv
->mesh_state
) == BATADV_MESH_ACTIVE
)
421 if (curr_gw
== gw_node
)
424 hlist_del_rcu(&gw_node
->list
);
425 batadv_gw_node_free_ref(gw_node
);
428 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
430 /* gw_deselect() needs to acquire the gw_list_lock */
432 batadv_gw_deselect(bat_priv
);
435 batadv_gw_node_free_ref(curr_gw
);
438 /* fails if orig_node has no router */
439 static int batadv_write_buffer_text(struct batadv_priv
*bat_priv
,
440 struct seq_file
*seq
,
441 const struct batadv_gw_node
*gw_node
)
443 struct batadv_gw_node
*curr_gw
;
444 struct batadv_neigh_node
*router
;
445 int down
, up
, ret
= -1;
447 batadv_gw_bandwidth_to_kbit(gw_node
->orig_node
->gw_flags
, &down
, &up
);
449 router
= batadv_orig_node_get_router(gw_node
->orig_node
);
453 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
455 ret
= seq_printf(seq
, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
456 (curr_gw
== gw_node
? "=>" : " "),
457 gw_node
->orig_node
->orig
,
458 router
->tq_avg
, router
->addr
,
459 router
->if_incoming
->net_dev
->name
,
460 gw_node
->orig_node
->gw_flags
,
461 (down
> 2048 ? down
/ 1024 : down
),
462 (down
> 2048 ? "MBit" : "KBit"),
463 (up
> 2048 ? up
/ 1024 : up
),
464 (up
> 2048 ? "MBit" : "KBit"));
466 batadv_neigh_node_free_ref(router
);
468 batadv_gw_node_free_ref(curr_gw
);
473 int batadv_gw_client_seq_print_text(struct seq_file
*seq
, void *offset
)
475 struct net_device
*net_dev
= (struct net_device
*)seq
->private;
476 struct batadv_priv
*bat_priv
= netdev_priv(net_dev
);
477 struct batadv_hard_iface
*primary_if
;
478 struct batadv_gw_node
*gw_node
;
479 struct hlist_node
*node
;
482 primary_if
= batadv_seq_print_text_primary_if_get(seq
);
487 " %-12s (%s/%i) %17s [%10s]: gw_class ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
488 "Gateway", "#", BATADV_TQ_MAX_VALUE
, "Nexthop", "outgoingIF",
489 BATADV_SOURCE_VERSION
, primary_if
->net_dev
->name
,
490 primary_if
->net_dev
->dev_addr
, net_dev
->name
);
493 hlist_for_each_entry_rcu(gw_node
, node
, &bat_priv
->gw
.list
, list
) {
494 if (gw_node
->deleted
)
497 /* fails if orig_node has no router */
498 if (batadv_write_buffer_text(bat_priv
, seq
, gw_node
) < 0)
506 seq_printf(seq
, "No gateways in range ...\n");
510 batadv_hardif_free_ref(primary_if
);
514 static bool batadv_is_type_dhcprequest(struct sk_buff
*skb
, int header_len
)
520 if (skb_linearize(skb
) < 0)
523 pkt_len
= skb_headlen(skb
);
525 if (pkt_len
< header_len
+ BATADV_DHCP_OPTIONS_OFFSET
+ 1)
528 p
= skb
->data
+ header_len
+ BATADV_DHCP_OPTIONS_OFFSET
;
529 pkt_len
-= header_len
+ BATADV_DHCP_OPTIONS_OFFSET
+ 1;
531 /* Access the dhcp option lists. Each entry is made up by:
532 * - octet 1: option type
533 * - octet 2: option data len (only if type != 255 and 0)
534 * - octet 3: option data
536 while (*p
!= 255 && !ret
) {
537 /* p now points to the first octet: option type */
539 /* type 53 is the message type option.
540 * Jump the len octet and go to the data octet
546 /* check if the message type is what we need */
547 if (*p
== BATADV_DHCP_REQUEST
)
550 } else if (*p
== 0) {
551 /* option type 0 (padding), just go forward */
557 /* This is any other option. So we get the length... */
563 /* ...and then we jump over the data */
564 if (pkt_len
< 1 + (*p
))
574 bool batadv_gw_is_dhcp_target(struct sk_buff
*skb
, unsigned int *header_len
)
576 struct ethhdr
*ethhdr
;
578 struct ipv6hdr
*ipv6hdr
;
579 struct udphdr
*udphdr
;
581 /* check for ethernet header */
582 if (!pskb_may_pull(skb
, *header_len
+ ETH_HLEN
))
584 ethhdr
= (struct ethhdr
*)skb
->data
;
585 *header_len
+= ETH_HLEN
;
587 /* check for initial vlan header */
588 if (ntohs(ethhdr
->h_proto
) == ETH_P_8021Q
) {
589 if (!pskb_may_pull(skb
, *header_len
+ VLAN_HLEN
))
591 ethhdr
= (struct ethhdr
*)(skb
->data
+ VLAN_HLEN
);
592 *header_len
+= VLAN_HLEN
;
595 /* check for ip header */
596 switch (ntohs(ethhdr
->h_proto
)) {
598 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*iphdr
)))
600 iphdr
= (struct iphdr
*)(skb
->data
+ *header_len
);
601 *header_len
+= iphdr
->ihl
* 4;
603 /* check for udp header */
604 if (iphdr
->protocol
!= IPPROTO_UDP
)
609 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*ipv6hdr
)))
611 ipv6hdr
= (struct ipv6hdr
*)(skb
->data
+ *header_len
);
612 *header_len
+= sizeof(*ipv6hdr
);
614 /* check for udp header */
615 if (ipv6hdr
->nexthdr
!= IPPROTO_UDP
)
623 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*udphdr
)))
625 udphdr
= (struct udphdr
*)(skb
->data
+ *header_len
);
626 *header_len
+= sizeof(*udphdr
);
628 /* check for bootp port */
629 if ((ntohs(ethhdr
->h_proto
) == ETH_P_IP
) &&
630 (ntohs(udphdr
->dest
) != 67))
633 if ((ntohs(ethhdr
->h_proto
) == ETH_P_IPV6
) &&
634 (ntohs(udphdr
->dest
) != 547))
640 bool batadv_gw_out_of_range(struct batadv_priv
*bat_priv
,
641 struct sk_buff
*skb
, struct ethhdr
*ethhdr
)
643 struct batadv_neigh_node
*neigh_curr
= NULL
, *neigh_old
= NULL
;
644 struct batadv_orig_node
*orig_dst_node
= NULL
;
645 struct batadv_gw_node
*curr_gw
= NULL
;
646 bool ret
, out_of_range
= false;
647 unsigned int header_len
= 0;
650 ret
= batadv_gw_is_dhcp_target(skb
, &header_len
);
654 orig_dst_node
= batadv_transtable_search(bat_priv
, ethhdr
->h_source
,
659 if (!orig_dst_node
->gw_flags
)
662 ret
= batadv_is_type_dhcprequest(skb
, header_len
);
666 switch (atomic_read(&bat_priv
->gw_mode
)) {
667 case BATADV_GW_MODE_SERVER
:
668 /* If we are a GW then we are our best GW. We can artificially
669 * set the tq towards ourself as the maximum value
671 curr_tq_avg
= BATADV_TQ_MAX_VALUE
;
673 case BATADV_GW_MODE_CLIENT
:
674 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
678 /* packet is going to our gateway */
679 if (curr_gw
->orig_node
== orig_dst_node
)
682 /* If the dhcp packet has been sent to a different gw,
683 * we have to evaluate whether the old gw is still
686 neigh_curr
= batadv_find_router(bat_priv
, curr_gw
->orig_node
,
691 curr_tq_avg
= neigh_curr
->tq_avg
;
693 case BATADV_GW_MODE_OFF
:
698 neigh_old
= batadv_find_router(bat_priv
, orig_dst_node
, NULL
);
702 if (curr_tq_avg
- neigh_old
->tq_avg
> BATADV_GW_THRESHOLD
)
707 batadv_orig_node_free_ref(orig_dst_node
);
709 batadv_gw_node_free_ref(curr_gw
);
711 batadv_neigh_node_free_ref(neigh_old
);
713 batadv_neigh_node_free_ref(neigh_curr
);