1 /* Copyright (C) 2009-2016 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, see <http://www.gnu.org/licenses/>.
18 #include "gateway_client.h"
21 #include <linux/atomic.h>
22 #include <linux/byteorder/generic.h>
23 #include <linux/etherdevice.h>
25 #include <linux/if_ether.h>
26 #include <linux/if_vlan.h>
29 #include <linux/ipv6.h>
30 #include <linux/kernel.h>
31 #include <linux/kref.h>
32 #include <linux/list.h>
33 #include <linux/netdevice.h>
34 #include <linux/rculist.h>
35 #include <linux/rcupdate.h>
36 #include <linux/seq_file.h>
37 #include <linux/skbuff.h>
38 #include <linux/slab.h>
39 #include <linux/spinlock.h>
40 #include <linux/stddef.h>
41 #include <linux/udp.h>
43 #include "gateway_common.h"
44 #include "hard-interface.h"
45 #include "originator.h"
49 #include "translation-table.h"
51 /* These are the offsets of the "hw type" and "hw address length" in the dhcp
52 * packet starting at the beginning of the dhcp header
54 #define BATADV_DHCP_HTYPE_OFFSET 1
55 #define BATADV_DHCP_HLEN_OFFSET 2
56 /* Value of htype representing Ethernet */
57 #define BATADV_DHCP_HTYPE_ETHERNET 0x01
58 /* This is the offset of the "chaddr" field in the dhcp packet starting at the
59 * beginning of the dhcp header
61 #define BATADV_DHCP_CHADDR_OFFSET 28
64 * batadv_gw_node_release - release gw_node from lists and queue for free after
66 * @ref: kref pointer of the gw_node
68 static void batadv_gw_node_release(struct kref
*ref
)
70 struct batadv_gw_node
*gw_node
;
72 gw_node
= container_of(ref
, struct batadv_gw_node
, refcount
);
74 batadv_orig_node_put(gw_node
->orig_node
);
75 kfree_rcu(gw_node
, rcu
);
79 * batadv_gw_node_free_ref - decrement the gw_node refcounter and possibly
81 * @gw_node: gateway node to free
83 static void batadv_gw_node_free_ref(struct batadv_gw_node
*gw_node
)
85 kref_put(&gw_node
->refcount
, batadv_gw_node_release
);
88 static struct batadv_gw_node
*
89 batadv_gw_get_selected_gw_node(struct batadv_priv
*bat_priv
)
91 struct batadv_gw_node
*gw_node
;
94 gw_node
= rcu_dereference(bat_priv
->gw
.curr_gw
);
98 if (!kref_get_unless_zero(&gw_node
->refcount
))
106 struct batadv_orig_node
*
107 batadv_gw_get_selected_orig(struct batadv_priv
*bat_priv
)
109 struct batadv_gw_node
*gw_node
;
110 struct batadv_orig_node
*orig_node
= NULL
;
112 gw_node
= batadv_gw_get_selected_gw_node(bat_priv
);
117 orig_node
= gw_node
->orig_node
;
121 if (!kref_get_unless_zero(&orig_node
->refcount
))
128 batadv_gw_node_free_ref(gw_node
);
132 static void batadv_gw_select(struct batadv_priv
*bat_priv
,
133 struct batadv_gw_node
*new_gw_node
)
135 struct batadv_gw_node
*curr_gw_node
;
137 spin_lock_bh(&bat_priv
->gw
.list_lock
);
139 if (new_gw_node
&& !kref_get_unless_zero(&new_gw_node
->refcount
))
142 curr_gw_node
= rcu_dereference_protected(bat_priv
->gw
.curr_gw
, 1);
143 rcu_assign_pointer(bat_priv
->gw
.curr_gw
, new_gw_node
);
146 batadv_gw_node_free_ref(curr_gw_node
);
148 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
152 * batadv_gw_reselect - force a gateway reselection
153 * @bat_priv: the bat priv with all the soft interface information
155 * Set a flag to remind the GW component to perform a new gateway reselection.
156 * However this function does not ensure that the current gateway is going to be
157 * deselected. The reselection mechanism may elect the same gateway once again.
159 * This means that invoking batadv_gw_reselect() does not guarantee a gateway
160 * change and therefore a uevent is not necessarily expected.
162 void batadv_gw_reselect(struct batadv_priv
*bat_priv
)
164 atomic_set(&bat_priv
->gw
.reselect
, 1);
167 static struct batadv_gw_node
*
168 batadv_gw_get_best_gw_node(struct batadv_priv
*bat_priv
)
170 struct batadv_neigh_node
*router
;
171 struct batadv_neigh_ifinfo
*router_ifinfo
;
172 struct batadv_gw_node
*gw_node
, *curr_gw
= NULL
;
173 u64 max_gw_factor
= 0;
174 u64 tmp_gw_factor
= 0;
177 struct batadv_orig_node
*orig_node
;
180 hlist_for_each_entry_rcu(gw_node
, &bat_priv
->gw
.list
, list
) {
181 orig_node
= gw_node
->orig_node
;
182 router
= batadv_orig_router_get(orig_node
, BATADV_IF_DEFAULT
);
186 router_ifinfo
= batadv_neigh_ifinfo_get(router
,
191 if (!kref_get_unless_zero(&gw_node
->refcount
))
194 tq_avg
= router_ifinfo
->bat_iv
.tq_avg
;
196 switch (atomic_read(&bat_priv
->gw_sel_class
)) {
197 case 1: /* fast connection */
198 tmp_gw_factor
= tq_avg
* tq_avg
;
199 tmp_gw_factor
*= gw_node
->bandwidth_down
;
200 tmp_gw_factor
*= 100 * 100;
201 tmp_gw_factor
>>= 18;
203 if ((tmp_gw_factor
> max_gw_factor
) ||
204 ((tmp_gw_factor
== max_gw_factor
) &&
205 (tq_avg
> max_tq
))) {
207 batadv_gw_node_free_ref(curr_gw
);
209 kref_get(&curr_gw
->refcount
);
213 default: /* 2: stable connection (use best statistic)
214 * 3: fast-switch (use best statistic but change as
215 * soon as a better gateway appears)
216 * XX: late-switch (use best statistic but change as
217 * soon as a better gateway appears which has
218 * $routing_class more tq points)
220 if (tq_avg
> max_tq
) {
222 batadv_gw_node_free_ref(curr_gw
);
224 kref_get(&curr_gw
->refcount
);
232 if (tmp_gw_factor
> max_gw_factor
)
233 max_gw_factor
= tmp_gw_factor
;
235 batadv_gw_node_free_ref(gw_node
);
238 batadv_neigh_node_free_ref(router
);
240 batadv_neigh_ifinfo_free_ref(router_ifinfo
);
248 * batadv_gw_check_client_stop - check if client mode has been switched off
249 * @bat_priv: the bat priv with all the soft interface information
251 * This function assumes the caller has checked that the gw state *is actually
252 * changing*. This function is not supposed to be called when there is no state
255 void batadv_gw_check_client_stop(struct batadv_priv
*bat_priv
)
257 struct batadv_gw_node
*curr_gw
;
259 if (atomic_read(&bat_priv
->gw_mode
) != BATADV_GW_MODE_CLIENT
)
262 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
266 /* deselect the current gateway so that next time that client mode is
267 * enabled a proper GW_ADD event can be sent
269 batadv_gw_select(bat_priv
, NULL
);
271 /* if batman-adv is switching the gw client mode off and a gateway was
272 * already selected, send a DEL uevent
274 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_DEL
, NULL
);
276 batadv_gw_node_free_ref(curr_gw
);
279 void batadv_gw_election(struct batadv_priv
*bat_priv
)
281 struct batadv_gw_node
*curr_gw
= NULL
;
282 struct batadv_gw_node
*next_gw
= NULL
;
283 struct batadv_neigh_node
*router
= NULL
;
284 struct batadv_neigh_ifinfo
*router_ifinfo
= NULL
;
285 char gw_addr
[18] = { '\0' };
287 if (atomic_read(&bat_priv
->gw_mode
) != BATADV_GW_MODE_CLIENT
)
290 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
292 if (!batadv_atomic_dec_not_zero(&bat_priv
->gw
.reselect
) && curr_gw
)
295 next_gw
= batadv_gw_get_best_gw_node(bat_priv
);
297 if (curr_gw
== next_gw
)
301 sprintf(gw_addr
, "%pM", next_gw
->orig_node
->orig
);
303 router
= batadv_orig_router_get(next_gw
->orig_node
,
306 batadv_gw_reselect(bat_priv
);
310 router_ifinfo
= batadv_neigh_ifinfo_get(router
,
312 if (!router_ifinfo
) {
313 batadv_gw_reselect(bat_priv
);
318 if ((curr_gw
) && (!next_gw
)) {
319 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
320 "Removing selected gateway - no gateway in range\n");
321 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_DEL
,
323 } else if ((!curr_gw
) && (next_gw
)) {
324 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
325 "Adding route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
326 next_gw
->orig_node
->orig
,
327 next_gw
->bandwidth_down
/ 10,
328 next_gw
->bandwidth_down
% 10,
329 next_gw
->bandwidth_up
/ 10,
330 next_gw
->bandwidth_up
% 10,
331 router_ifinfo
->bat_iv
.tq_avg
);
332 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_ADD
,
335 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
336 "Changing route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
337 next_gw
->orig_node
->orig
,
338 next_gw
->bandwidth_down
/ 10,
339 next_gw
->bandwidth_down
% 10,
340 next_gw
->bandwidth_up
/ 10,
341 next_gw
->bandwidth_up
% 10,
342 router_ifinfo
->bat_iv
.tq_avg
);
343 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_CHANGE
,
347 batadv_gw_select(bat_priv
, next_gw
);
351 batadv_gw_node_free_ref(curr_gw
);
353 batadv_gw_node_free_ref(next_gw
);
355 batadv_neigh_node_free_ref(router
);
357 batadv_neigh_ifinfo_free_ref(router_ifinfo
);
360 void batadv_gw_check_election(struct batadv_priv
*bat_priv
,
361 struct batadv_orig_node
*orig_node
)
363 struct batadv_neigh_ifinfo
*router_orig_tq
= NULL
;
364 struct batadv_neigh_ifinfo
*router_gw_tq
= NULL
;
365 struct batadv_orig_node
*curr_gw_orig
;
366 struct batadv_neigh_node
*router_gw
= NULL
;
367 struct batadv_neigh_node
*router_orig
= NULL
;
368 u8 gw_tq_avg
, orig_tq_avg
;
370 curr_gw_orig
= batadv_gw_get_selected_orig(bat_priv
);
374 router_gw
= batadv_orig_router_get(curr_gw_orig
, BATADV_IF_DEFAULT
);
378 router_gw_tq
= batadv_neigh_ifinfo_get(router_gw
,
383 /* this node already is the gateway */
384 if (curr_gw_orig
== orig_node
)
387 router_orig
= batadv_orig_router_get(orig_node
, BATADV_IF_DEFAULT
);
391 router_orig_tq
= batadv_neigh_ifinfo_get(router_orig
,
396 gw_tq_avg
= router_gw_tq
->bat_iv
.tq_avg
;
397 orig_tq_avg
= router_orig_tq
->bat_iv
.tq_avg
;
399 /* the TQ value has to be better */
400 if (orig_tq_avg
< gw_tq_avg
)
403 /* if the routing class is greater than 3 the value tells us how much
404 * greater the TQ value of the new gateway must be
406 if ((atomic_read(&bat_priv
->gw_sel_class
) > 3) &&
407 (orig_tq_avg
- gw_tq_avg
< atomic_read(&bat_priv
->gw_sel_class
)))
410 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
411 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
412 gw_tq_avg
, orig_tq_avg
);
415 batadv_gw_reselect(bat_priv
);
418 batadv_orig_node_put(curr_gw_orig
);
420 batadv_neigh_node_free_ref(router_gw
);
422 batadv_neigh_node_free_ref(router_orig
);
424 batadv_neigh_ifinfo_free_ref(router_gw_tq
);
426 batadv_neigh_ifinfo_free_ref(router_orig_tq
);
430 * batadv_gw_node_add - add gateway node to list of available gateways
431 * @bat_priv: the bat priv with all the soft interface information
432 * @orig_node: originator announcing gateway capabilities
433 * @gateway: announced bandwidth information
435 static void batadv_gw_node_add(struct batadv_priv
*bat_priv
,
436 struct batadv_orig_node
*orig_node
,
437 struct batadv_tvlv_gateway_data
*gateway
)
439 struct batadv_gw_node
*gw_node
;
441 if (gateway
->bandwidth_down
== 0)
444 if (!kref_get_unless_zero(&orig_node
->refcount
))
447 gw_node
= kzalloc(sizeof(*gw_node
), GFP_ATOMIC
);
449 batadv_orig_node_put(orig_node
);
453 INIT_HLIST_NODE(&gw_node
->list
);
454 gw_node
->orig_node
= orig_node
;
455 gw_node
->bandwidth_down
= ntohl(gateway
->bandwidth_down
);
456 gw_node
->bandwidth_up
= ntohl(gateway
->bandwidth_up
);
457 kref_init(&gw_node
->refcount
);
459 spin_lock_bh(&bat_priv
->gw
.list_lock
);
460 hlist_add_head_rcu(&gw_node
->list
, &bat_priv
->gw
.list
);
461 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
463 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
464 "Found new gateway %pM -> gw bandwidth: %u.%u/%u.%u MBit\n",
466 ntohl(gateway
->bandwidth_down
) / 10,
467 ntohl(gateway
->bandwidth_down
) % 10,
468 ntohl(gateway
->bandwidth_up
) / 10,
469 ntohl(gateway
->bandwidth_up
) % 10);
473 * batadv_gw_node_get - retrieve gateway node from list of available gateways
474 * @bat_priv: the bat priv with all the soft interface information
475 * @orig_node: originator announcing gateway capabilities
477 * Return: gateway node if found or NULL otherwise.
479 static struct batadv_gw_node
*
480 batadv_gw_node_get(struct batadv_priv
*bat_priv
,
481 struct batadv_orig_node
*orig_node
)
483 struct batadv_gw_node
*gw_node_tmp
, *gw_node
= NULL
;
486 hlist_for_each_entry_rcu(gw_node_tmp
, &bat_priv
->gw
.list
, list
) {
487 if (gw_node_tmp
->orig_node
!= orig_node
)
490 if (!kref_get_unless_zero(&gw_node_tmp
->refcount
))
493 gw_node
= gw_node_tmp
;
502 * batadv_gw_node_update - update list of available gateways with changed
503 * bandwidth information
504 * @bat_priv: the bat priv with all the soft interface information
505 * @orig_node: originator announcing gateway capabilities
506 * @gateway: announced bandwidth information
508 void batadv_gw_node_update(struct batadv_priv
*bat_priv
,
509 struct batadv_orig_node
*orig_node
,
510 struct batadv_tvlv_gateway_data
*gateway
)
512 struct batadv_gw_node
*gw_node
, *curr_gw
= NULL
;
514 gw_node
= batadv_gw_node_get(bat_priv
, orig_node
);
516 batadv_gw_node_add(bat_priv
, orig_node
, gateway
);
520 if ((gw_node
->bandwidth_down
== ntohl(gateway
->bandwidth_down
)) &&
521 (gw_node
->bandwidth_up
== ntohl(gateway
->bandwidth_up
)))
524 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
525 "Gateway bandwidth of originator %pM changed from %u.%u/%u.%u MBit to %u.%u/%u.%u MBit\n",
527 gw_node
->bandwidth_down
/ 10,
528 gw_node
->bandwidth_down
% 10,
529 gw_node
->bandwidth_up
/ 10,
530 gw_node
->bandwidth_up
% 10,
531 ntohl(gateway
->bandwidth_down
) / 10,
532 ntohl(gateway
->bandwidth_down
) % 10,
533 ntohl(gateway
->bandwidth_up
) / 10,
534 ntohl(gateway
->bandwidth_up
) % 10);
536 gw_node
->bandwidth_down
= ntohl(gateway
->bandwidth_down
);
537 gw_node
->bandwidth_up
= ntohl(gateway
->bandwidth_up
);
539 if (ntohl(gateway
->bandwidth_down
) == 0) {
540 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
541 "Gateway %pM removed from gateway list\n",
544 /* Note: We don't need a NULL check here, since curr_gw never
547 spin_lock_bh(&bat_priv
->gw
.list_lock
);
548 if (!hlist_unhashed(&gw_node
->list
)) {
549 hlist_del_init_rcu(&gw_node
->list
);
550 batadv_gw_node_free_ref(gw_node
);
552 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
554 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
555 if (gw_node
== curr_gw
)
556 batadv_gw_reselect(bat_priv
);
559 batadv_gw_node_free_ref(curr_gw
);
564 batadv_gw_node_free_ref(gw_node
);
567 void batadv_gw_node_delete(struct batadv_priv
*bat_priv
,
568 struct batadv_orig_node
*orig_node
)
570 struct batadv_tvlv_gateway_data gateway
;
572 gateway
.bandwidth_down
= 0;
573 gateway
.bandwidth_up
= 0;
575 batadv_gw_node_update(bat_priv
, orig_node
, &gateway
);
578 void batadv_gw_node_free(struct batadv_priv
*bat_priv
)
580 struct batadv_gw_node
*gw_node
;
581 struct hlist_node
*node_tmp
;
583 spin_lock_bh(&bat_priv
->gw
.list_lock
);
584 hlist_for_each_entry_safe(gw_node
, node_tmp
,
585 &bat_priv
->gw
.list
, list
) {
586 hlist_del_init_rcu(&gw_node
->list
);
587 batadv_gw_node_free_ref(gw_node
);
589 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
592 /* fails if orig_node has no router */
593 static int batadv_write_buffer_text(struct batadv_priv
*bat_priv
,
594 struct seq_file
*seq
,
595 const struct batadv_gw_node
*gw_node
)
597 struct batadv_gw_node
*curr_gw
;
598 struct batadv_neigh_node
*router
;
599 struct batadv_neigh_ifinfo
*router_ifinfo
= NULL
;
602 router
= batadv_orig_router_get(gw_node
->orig_node
, BATADV_IF_DEFAULT
);
606 router_ifinfo
= batadv_neigh_ifinfo_get(router
, BATADV_IF_DEFAULT
);
610 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
612 seq_printf(seq
, "%s %pM (%3i) %pM [%10s]: %u.%u/%u.%u MBit\n",
613 (curr_gw
== gw_node
? "=>" : " "),
614 gw_node
->orig_node
->orig
,
615 router_ifinfo
->bat_iv
.tq_avg
, router
->addr
,
616 router
->if_incoming
->net_dev
->name
,
617 gw_node
->bandwidth_down
/ 10,
618 gw_node
->bandwidth_down
% 10,
619 gw_node
->bandwidth_up
/ 10,
620 gw_node
->bandwidth_up
% 10);
621 ret
= seq_has_overflowed(seq
) ? -1 : 0;
624 batadv_gw_node_free_ref(curr_gw
);
627 batadv_neigh_ifinfo_free_ref(router_ifinfo
);
629 batadv_neigh_node_free_ref(router
);
633 int batadv_gw_client_seq_print_text(struct seq_file
*seq
, void *offset
)
635 struct net_device
*net_dev
= (struct net_device
*)seq
->private;
636 struct batadv_priv
*bat_priv
= netdev_priv(net_dev
);
637 struct batadv_hard_iface
*primary_if
;
638 struct batadv_gw_node
*gw_node
;
641 primary_if
= batadv_seq_print_text_primary_if_get(seq
);
646 " %-12s (%s/%i) %17s [%10s]: advertised uplink bandwidth ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
647 "Gateway", "#", BATADV_TQ_MAX_VALUE
, "Nexthop", "outgoingIF",
648 BATADV_SOURCE_VERSION
, primary_if
->net_dev
->name
,
649 primary_if
->net_dev
->dev_addr
, net_dev
->name
);
652 hlist_for_each_entry_rcu(gw_node
, &bat_priv
->gw
.list
, list
) {
653 /* fails if orig_node has no router */
654 if (batadv_write_buffer_text(bat_priv
, seq
, gw_node
) < 0)
662 seq_puts(seq
, "No gateways in range ...\n");
666 batadv_hardif_put(primary_if
);
671 * batadv_gw_dhcp_recipient_get - check if a packet is a DHCP message
672 * @skb: the packet to check
673 * @header_len: a pointer to the batman-adv header size
674 * @chaddr: buffer where the client address will be stored. Valid
675 * only if the function returns BATADV_DHCP_TO_CLIENT
677 * This function may re-allocate the data buffer of the skb passed as argument.
680 * - BATADV_DHCP_NO if the packet is not a dhcp message or if there was an error
682 * - BATADV_DHCP_TO_SERVER if this is a message going to the DHCP server
683 * - BATADV_DHCP_TO_CLIENT if this is a message going to a DHCP client
685 enum batadv_dhcp_recipient
686 batadv_gw_dhcp_recipient_get(struct sk_buff
*skb
, unsigned int *header_len
,
689 enum batadv_dhcp_recipient ret
= BATADV_DHCP_NO
;
690 struct ethhdr
*ethhdr
;
692 struct ipv6hdr
*ipv6hdr
;
693 struct udphdr
*udphdr
;
694 struct vlan_ethhdr
*vhdr
;
699 /* check for ethernet header */
700 if (!pskb_may_pull(skb
, *header_len
+ ETH_HLEN
))
701 return BATADV_DHCP_NO
;
703 ethhdr
= eth_hdr(skb
);
704 proto
= ethhdr
->h_proto
;
705 *header_len
+= ETH_HLEN
;
707 /* check for initial vlan header */
708 if (proto
== htons(ETH_P_8021Q
)) {
709 if (!pskb_may_pull(skb
, *header_len
+ VLAN_HLEN
))
710 return BATADV_DHCP_NO
;
712 vhdr
= vlan_eth_hdr(skb
);
713 proto
= vhdr
->h_vlan_encapsulated_proto
;
714 *header_len
+= VLAN_HLEN
;
717 /* check for ip header */
719 case htons(ETH_P_IP
):
720 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*iphdr
)))
721 return BATADV_DHCP_NO
;
723 iphdr
= (struct iphdr
*)(skb
->data
+ *header_len
);
724 *header_len
+= iphdr
->ihl
* 4;
726 /* check for udp header */
727 if (iphdr
->protocol
!= IPPROTO_UDP
)
728 return BATADV_DHCP_NO
;
731 case htons(ETH_P_IPV6
):
732 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*ipv6hdr
)))
733 return BATADV_DHCP_NO
;
735 ipv6hdr
= (struct ipv6hdr
*)(skb
->data
+ *header_len
);
736 *header_len
+= sizeof(*ipv6hdr
);
738 /* check for udp header */
739 if (ipv6hdr
->nexthdr
!= IPPROTO_UDP
)
740 return BATADV_DHCP_NO
;
744 return BATADV_DHCP_NO
;
747 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*udphdr
)))
748 return BATADV_DHCP_NO
;
750 udphdr
= (struct udphdr
*)(skb
->data
+ *header_len
);
751 *header_len
+= sizeof(*udphdr
);
753 /* check for bootp port */
755 case htons(ETH_P_IP
):
756 if (udphdr
->dest
== htons(67))
757 ret
= BATADV_DHCP_TO_SERVER
;
758 else if (udphdr
->source
== htons(67))
759 ret
= BATADV_DHCP_TO_CLIENT
;
761 case htons(ETH_P_IPV6
):
762 if (udphdr
->dest
== htons(547))
763 ret
= BATADV_DHCP_TO_SERVER
;
764 else if (udphdr
->source
== htons(547))
765 ret
= BATADV_DHCP_TO_CLIENT
;
769 chaddr_offset
= *header_len
+ BATADV_DHCP_CHADDR_OFFSET
;
770 /* store the client address if the message is going to a client */
771 if (ret
== BATADV_DHCP_TO_CLIENT
&&
772 pskb_may_pull(skb
, chaddr_offset
+ ETH_ALEN
)) {
773 /* check if the DHCP packet carries an Ethernet DHCP */
774 p
= skb
->data
+ *header_len
+ BATADV_DHCP_HTYPE_OFFSET
;
775 if (*p
!= BATADV_DHCP_HTYPE_ETHERNET
)
776 return BATADV_DHCP_NO
;
778 /* check if the DHCP packet carries a valid Ethernet address */
779 p
= skb
->data
+ *header_len
+ BATADV_DHCP_HLEN_OFFSET
;
781 return BATADV_DHCP_NO
;
783 ether_addr_copy(chaddr
, skb
->data
+ chaddr_offset
);
790 * batadv_gw_out_of_range - check if the dhcp request destination is the best gw
791 * @bat_priv: the bat priv with all the soft interface information
792 * @skb: the outgoing packet
794 * Check if the skb is a DHCP request and if it is sent to the current best GW
795 * server. Due to topology changes it may be the case that the GW server
796 * previously selected is not the best one anymore.
798 * This call might reallocate skb data.
799 * Must be invoked only when the DHCP packet is going TO a DHCP SERVER.
801 * Return: true if the packet destination is unicast and it is not the best gw,
804 bool batadv_gw_out_of_range(struct batadv_priv
*bat_priv
,
807 struct batadv_neigh_node
*neigh_curr
= NULL
;
808 struct batadv_neigh_node
*neigh_old
= NULL
;
809 struct batadv_orig_node
*orig_dst_node
= NULL
;
810 struct batadv_gw_node
*gw_node
= NULL
;
811 struct batadv_gw_node
*curr_gw
= NULL
;
812 struct batadv_neigh_ifinfo
*curr_ifinfo
, *old_ifinfo
;
813 struct ethhdr
*ethhdr
= (struct ethhdr
*)skb
->data
;
814 bool out_of_range
= false;
818 vid
= batadv_get_vid(skb
, 0);
820 orig_dst_node
= batadv_transtable_search(bat_priv
, ethhdr
->h_source
,
821 ethhdr
->h_dest
, vid
);
825 gw_node
= batadv_gw_node_get(bat_priv
, orig_dst_node
);
829 switch (atomic_read(&bat_priv
->gw_mode
)) {
830 case BATADV_GW_MODE_SERVER
:
831 /* If we are a GW then we are our best GW. We can artificially
832 * set the tq towards ourself as the maximum value
834 curr_tq_avg
= BATADV_TQ_MAX_VALUE
;
836 case BATADV_GW_MODE_CLIENT
:
837 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
841 /* packet is going to our gateway */
842 if (curr_gw
->orig_node
== orig_dst_node
)
845 /* If the dhcp packet has been sent to a different gw,
846 * we have to evaluate whether the old gw is still
849 neigh_curr
= batadv_find_router(bat_priv
, curr_gw
->orig_node
,
854 curr_ifinfo
= batadv_neigh_ifinfo_get(neigh_curr
,
859 curr_tq_avg
= curr_ifinfo
->bat_iv
.tq_avg
;
860 batadv_neigh_ifinfo_free_ref(curr_ifinfo
);
863 case BATADV_GW_MODE_OFF
:
868 neigh_old
= batadv_find_router(bat_priv
, orig_dst_node
, NULL
);
872 old_ifinfo
= batadv_neigh_ifinfo_get(neigh_old
, BATADV_IF_DEFAULT
);
876 if ((curr_tq_avg
- old_ifinfo
->bat_iv
.tq_avg
) > BATADV_GW_THRESHOLD
)
878 batadv_neigh_ifinfo_free_ref(old_ifinfo
);
882 batadv_orig_node_put(orig_dst_node
);
884 batadv_gw_node_free_ref(curr_gw
);
886 batadv_gw_node_free_ref(gw_node
);
888 batadv_neigh_node_free_ref(neigh_old
);
890 batadv_neigh_node_free_ref(neigh_curr
);