1 /* Copyright (C) 2009-2014 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/>.
20 #include "gateway_client.h"
21 #include "gateway_common.h"
22 #include "hard-interface.h"
23 #include "originator.h"
24 #include "translation-table.h"
27 #include <linux/ipv6.h>
28 #include <linux/udp.h>
29 #include <linux/if_vlan.h>
31 /* These are the offsets of the "hw type" and "hw address length" in the dhcp
32 * packet starting at the beginning of the dhcp header
34 #define BATADV_DHCP_HTYPE_OFFSET 1
35 #define BATADV_DHCP_HLEN_OFFSET 2
36 /* Value of htype representing Ethernet */
37 #define BATADV_DHCP_HTYPE_ETHERNET 0x01
38 /* This is the offset of the "chaddr" field in the dhcp packet starting at the
39 * beginning of the dhcp header
41 #define BATADV_DHCP_CHADDR_OFFSET 28
43 static void batadv_gw_node_free_ref(struct batadv_gw_node
*gw_node
)
45 if (atomic_dec_and_test(&gw_node
->refcount
))
46 kfree_rcu(gw_node
, rcu
);
49 static struct batadv_gw_node
*
50 batadv_gw_get_selected_gw_node(struct batadv_priv
*bat_priv
)
52 struct batadv_gw_node
*gw_node
;
55 gw_node
= rcu_dereference(bat_priv
->gw
.curr_gw
);
59 if (!atomic_inc_not_zero(&gw_node
->refcount
))
67 struct batadv_orig_node
*
68 batadv_gw_get_selected_orig(struct batadv_priv
*bat_priv
)
70 struct batadv_gw_node
*gw_node
;
71 struct batadv_orig_node
*orig_node
= NULL
;
73 gw_node
= batadv_gw_get_selected_gw_node(bat_priv
);
78 orig_node
= gw_node
->orig_node
;
82 if (!atomic_inc_not_zero(&orig_node
->refcount
))
89 batadv_gw_node_free_ref(gw_node
);
93 static void batadv_gw_select(struct batadv_priv
*bat_priv
,
94 struct batadv_gw_node
*new_gw_node
)
96 struct batadv_gw_node
*curr_gw_node
;
98 spin_lock_bh(&bat_priv
->gw
.list_lock
);
100 if (new_gw_node
&& !atomic_inc_not_zero(&new_gw_node
->refcount
))
103 curr_gw_node
= rcu_dereference_protected(bat_priv
->gw
.curr_gw
, 1);
104 rcu_assign_pointer(bat_priv
->gw
.curr_gw
, new_gw_node
);
107 batadv_gw_node_free_ref(curr_gw_node
);
109 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
113 * batadv_gw_reselect - force a gateway reselection
114 * @bat_priv: the bat priv with all the soft interface information
116 * Set a flag to remind the GW component to perform a new gateway reselection.
117 * However this function does not ensure that the current gateway is going to be
118 * deselected. The reselection mechanism may elect the same gateway once again.
120 * This means that invoking batadv_gw_reselect() does not guarantee a gateway
121 * change and therefore a uevent is not necessarily expected.
123 void batadv_gw_reselect(struct batadv_priv
*bat_priv
)
125 atomic_set(&bat_priv
->gw
.reselect
, 1);
128 static struct batadv_gw_node
*
129 batadv_gw_get_best_gw_node(struct batadv_priv
*bat_priv
)
131 struct batadv_neigh_node
*router
;
132 struct batadv_neigh_ifinfo
*router_ifinfo
;
133 struct batadv_gw_node
*gw_node
, *curr_gw
= NULL
;
134 uint32_t max_gw_factor
= 0, tmp_gw_factor
= 0;
138 struct batadv_orig_node
*orig_node
;
140 gw_divisor
= BATADV_TQ_LOCAL_WINDOW_SIZE
* BATADV_TQ_LOCAL_WINDOW_SIZE
;
144 hlist_for_each_entry_rcu(gw_node
, &bat_priv
->gw
.list
, list
) {
145 if (gw_node
->deleted
)
148 orig_node
= gw_node
->orig_node
;
149 router
= batadv_orig_router_get(orig_node
, BATADV_IF_DEFAULT
);
153 router_ifinfo
= batadv_neigh_ifinfo_get(router
,
158 if (!atomic_inc_not_zero(&gw_node
->refcount
))
161 tq_avg
= router_ifinfo
->bat_iv
.tq_avg
;
163 switch (atomic_read(&bat_priv
->gw_sel_class
)) {
164 case 1: /* fast connection */
165 tmp_gw_factor
= tq_avg
* tq_avg
;
166 tmp_gw_factor
*= gw_node
->bandwidth_down
;
167 tmp_gw_factor
*= 100 * 100;
168 tmp_gw_factor
/= gw_divisor
;
170 if ((tmp_gw_factor
> max_gw_factor
) ||
171 ((tmp_gw_factor
== max_gw_factor
) &&
172 (tq_avg
> max_tq
))) {
174 batadv_gw_node_free_ref(curr_gw
);
176 atomic_inc(&curr_gw
->refcount
);
180 default: /* 2: stable connection (use best statistic)
181 * 3: fast-switch (use best statistic but change as
182 * soon as a better gateway appears)
183 * XX: late-switch (use best statistic but change as
184 * soon as a better gateway appears which has
185 * $routing_class more tq points)
187 if (tq_avg
> max_tq
) {
189 batadv_gw_node_free_ref(curr_gw
);
191 atomic_inc(&curr_gw
->refcount
);
199 if (tmp_gw_factor
> max_gw_factor
)
200 max_gw_factor
= tmp_gw_factor
;
202 batadv_gw_node_free_ref(gw_node
);
205 batadv_neigh_node_free_ref(router
);
207 batadv_neigh_ifinfo_free_ref(router_ifinfo
);
215 * batadv_gw_check_client_stop - check if client mode has been switched off
216 * @bat_priv: the bat priv with all the soft interface information
218 * This function assumes the caller has checked that the gw state *is actually
219 * changing*. This function is not supposed to be called when there is no state
222 void batadv_gw_check_client_stop(struct batadv_priv
*bat_priv
)
224 struct batadv_gw_node
*curr_gw
;
226 if (atomic_read(&bat_priv
->gw_mode
) != BATADV_GW_MODE_CLIENT
)
229 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
233 /* deselect the current gateway so that next time that client mode is
234 * enabled a proper GW_ADD event can be sent
236 batadv_gw_select(bat_priv
, NULL
);
238 /* if batman-adv is switching the gw client mode off and a gateway was
239 * already selected, send a DEL uevent
241 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_DEL
, NULL
);
243 batadv_gw_node_free_ref(curr_gw
);
246 void batadv_gw_election(struct batadv_priv
*bat_priv
)
248 struct batadv_gw_node
*curr_gw
= NULL
, *next_gw
= NULL
;
249 struct batadv_neigh_node
*router
= NULL
;
250 struct batadv_neigh_ifinfo
*router_ifinfo
= NULL
;
251 char gw_addr
[18] = { '\0' };
253 if (atomic_read(&bat_priv
->gw_mode
) != BATADV_GW_MODE_CLIENT
)
256 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
258 if (!batadv_atomic_dec_not_zero(&bat_priv
->gw
.reselect
) && curr_gw
)
261 next_gw
= batadv_gw_get_best_gw_node(bat_priv
);
263 if (curr_gw
== next_gw
)
267 sprintf(gw_addr
, "%pM", next_gw
->orig_node
->orig
);
269 router
= batadv_orig_router_get(next_gw
->orig_node
,
272 batadv_gw_reselect(bat_priv
);
276 router_ifinfo
= batadv_neigh_ifinfo_get(router
,
278 if (!router_ifinfo
) {
279 batadv_gw_reselect(bat_priv
);
284 if ((curr_gw
) && (!next_gw
)) {
285 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
286 "Removing selected gateway - no gateway in range\n");
287 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_DEL
,
289 } else if ((!curr_gw
) && (next_gw
)) {
290 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
291 "Adding route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
292 next_gw
->orig_node
->orig
,
293 next_gw
->bandwidth_down
/ 10,
294 next_gw
->bandwidth_down
% 10,
295 next_gw
->bandwidth_up
/ 10,
296 next_gw
->bandwidth_up
% 10,
297 router_ifinfo
->bat_iv
.tq_avg
);
298 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_ADD
,
301 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
302 "Changing route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
303 next_gw
->orig_node
->orig
,
304 next_gw
->bandwidth_down
/ 10,
305 next_gw
->bandwidth_down
% 10,
306 next_gw
->bandwidth_up
/ 10,
307 next_gw
->bandwidth_up
% 10,
308 router_ifinfo
->bat_iv
.tq_avg
);
309 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_CHANGE
,
313 batadv_gw_select(bat_priv
, next_gw
);
317 batadv_gw_node_free_ref(curr_gw
);
319 batadv_gw_node_free_ref(next_gw
);
321 batadv_neigh_node_free_ref(router
);
323 batadv_neigh_ifinfo_free_ref(router_ifinfo
);
326 void batadv_gw_check_election(struct batadv_priv
*bat_priv
,
327 struct batadv_orig_node
*orig_node
)
329 struct batadv_neigh_ifinfo
*router_orig_tq
= NULL
;
330 struct batadv_neigh_ifinfo
*router_gw_tq
= NULL
;
331 struct batadv_orig_node
*curr_gw_orig
;
332 struct batadv_neigh_node
*router_gw
= NULL
, *router_orig
= NULL
;
333 uint8_t gw_tq_avg
, orig_tq_avg
;
335 curr_gw_orig
= batadv_gw_get_selected_orig(bat_priv
);
339 router_gw
= batadv_orig_router_get(curr_gw_orig
, BATADV_IF_DEFAULT
);
343 router_gw_tq
= batadv_neigh_ifinfo_get(router_gw
,
348 /* this node already is the gateway */
349 if (curr_gw_orig
== orig_node
)
352 router_orig
= batadv_orig_router_get(orig_node
, BATADV_IF_DEFAULT
);
356 router_orig_tq
= batadv_neigh_ifinfo_get(router_orig
,
361 gw_tq_avg
= router_gw_tq
->bat_iv
.tq_avg
;
362 orig_tq_avg
= router_orig_tq
->bat_iv
.tq_avg
;
364 /* the TQ value has to be better */
365 if (orig_tq_avg
< gw_tq_avg
)
368 /* if the routing class is greater than 3 the value tells us how much
369 * greater the TQ value of the new gateway must be
371 if ((atomic_read(&bat_priv
->gw_sel_class
) > 3) &&
372 (orig_tq_avg
- gw_tq_avg
< atomic_read(&bat_priv
->gw_sel_class
)))
375 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
376 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
377 gw_tq_avg
, orig_tq_avg
);
380 batadv_gw_reselect(bat_priv
);
383 batadv_orig_node_free_ref(curr_gw_orig
);
385 batadv_neigh_node_free_ref(router_gw
);
387 batadv_neigh_node_free_ref(router_orig
);
389 batadv_neigh_ifinfo_free_ref(router_gw_tq
);
391 batadv_neigh_ifinfo_free_ref(router_orig_tq
);
395 * batadv_gw_node_add - add gateway node to list of available gateways
396 * @bat_priv: the bat priv with all the soft interface information
397 * @orig_node: originator announcing gateway capabilities
398 * @gateway: announced bandwidth information
400 static void batadv_gw_node_add(struct batadv_priv
*bat_priv
,
401 struct batadv_orig_node
*orig_node
,
402 struct batadv_tvlv_gateway_data
*gateway
)
404 struct batadv_gw_node
*gw_node
;
406 if (gateway
->bandwidth_down
== 0)
409 gw_node
= kzalloc(sizeof(*gw_node
), GFP_ATOMIC
);
413 INIT_HLIST_NODE(&gw_node
->list
);
414 gw_node
->orig_node
= orig_node
;
415 atomic_set(&gw_node
->refcount
, 1);
417 spin_lock_bh(&bat_priv
->gw
.list_lock
);
418 hlist_add_head_rcu(&gw_node
->list
, &bat_priv
->gw
.list
);
419 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
421 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
422 "Found new gateway %pM -> gw bandwidth: %u.%u/%u.%u MBit\n",
424 ntohl(gateway
->bandwidth_down
) / 10,
425 ntohl(gateway
->bandwidth_down
) % 10,
426 ntohl(gateway
->bandwidth_up
) / 10,
427 ntohl(gateway
->bandwidth_up
) % 10);
431 * batadv_gw_node_get - retrieve gateway node from list of available gateways
432 * @bat_priv: the bat priv with all the soft interface information
433 * @orig_node: originator announcing gateway capabilities
435 * Returns gateway node if found or NULL otherwise.
437 static struct batadv_gw_node
*
438 batadv_gw_node_get(struct batadv_priv
*bat_priv
,
439 struct batadv_orig_node
*orig_node
)
441 struct batadv_gw_node
*gw_node_tmp
, *gw_node
= NULL
;
444 hlist_for_each_entry_rcu(gw_node_tmp
, &bat_priv
->gw
.list
, list
) {
445 if (gw_node_tmp
->orig_node
!= orig_node
)
448 if (gw_node_tmp
->deleted
)
451 if (!atomic_inc_not_zero(&gw_node_tmp
->refcount
))
454 gw_node
= gw_node_tmp
;
463 * batadv_gw_node_update - update list of available gateways with changed
464 * bandwidth information
465 * @bat_priv: the bat priv with all the soft interface information
466 * @orig_node: originator announcing gateway capabilities
467 * @gateway: announced bandwidth information
469 void batadv_gw_node_update(struct batadv_priv
*bat_priv
,
470 struct batadv_orig_node
*orig_node
,
471 struct batadv_tvlv_gateway_data
*gateway
)
473 struct batadv_gw_node
*gw_node
, *curr_gw
= NULL
;
475 gw_node
= batadv_gw_node_get(bat_priv
, orig_node
);
477 batadv_gw_node_add(bat_priv
, orig_node
, gateway
);
481 if ((gw_node
->bandwidth_down
== ntohl(gateway
->bandwidth_down
)) &&
482 (gw_node
->bandwidth_up
== ntohl(gateway
->bandwidth_up
)))
485 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
486 "Gateway bandwidth of originator %pM changed from %u.%u/%u.%u MBit to %u.%u/%u.%u MBit\n",
488 gw_node
->bandwidth_down
/ 10,
489 gw_node
->bandwidth_down
% 10,
490 gw_node
->bandwidth_up
/ 10,
491 gw_node
->bandwidth_up
% 10,
492 ntohl(gateway
->bandwidth_down
) / 10,
493 ntohl(gateway
->bandwidth_down
) % 10,
494 ntohl(gateway
->bandwidth_up
) / 10,
495 ntohl(gateway
->bandwidth_up
) % 10);
497 gw_node
->bandwidth_down
= ntohl(gateway
->bandwidth_down
);
498 gw_node
->bandwidth_up
= ntohl(gateway
->bandwidth_up
);
500 gw_node
->deleted
= 0;
501 if (ntohl(gateway
->bandwidth_down
) == 0) {
502 gw_node
->deleted
= jiffies
;
503 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
504 "Gateway %pM removed from gateway list\n",
507 /* Note: We don't need a NULL check here, since curr_gw never
510 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
511 if (gw_node
== curr_gw
)
512 batadv_gw_reselect(bat_priv
);
517 batadv_gw_node_free_ref(curr_gw
);
519 batadv_gw_node_free_ref(gw_node
);
522 void batadv_gw_node_delete(struct batadv_priv
*bat_priv
,
523 struct batadv_orig_node
*orig_node
)
525 struct batadv_tvlv_gateway_data gateway
;
527 gateway
.bandwidth_down
= 0;
528 gateway
.bandwidth_up
= 0;
530 batadv_gw_node_update(bat_priv
, orig_node
, &gateway
);
533 void batadv_gw_node_purge(struct batadv_priv
*bat_priv
)
535 struct batadv_gw_node
*gw_node
, *curr_gw
;
536 struct hlist_node
*node_tmp
;
537 unsigned long timeout
= msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT
);
540 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
542 spin_lock_bh(&bat_priv
->gw
.list_lock
);
544 hlist_for_each_entry_safe(gw_node
, node_tmp
,
545 &bat_priv
->gw
.list
, list
) {
546 if (((!gw_node
->deleted
) ||
547 (time_before(jiffies
, gw_node
->deleted
+ timeout
))) &&
548 atomic_read(&bat_priv
->mesh_state
) == BATADV_MESH_ACTIVE
)
551 if (curr_gw
== gw_node
)
554 hlist_del_rcu(&gw_node
->list
);
555 batadv_gw_node_free_ref(gw_node
);
558 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
560 /* gw_reselect() needs to acquire the gw_list_lock */
562 batadv_gw_reselect(bat_priv
);
565 batadv_gw_node_free_ref(curr_gw
);
568 /* fails if orig_node has no router */
569 static int batadv_write_buffer_text(struct batadv_priv
*bat_priv
,
570 struct seq_file
*seq
,
571 const struct batadv_gw_node
*gw_node
)
573 struct batadv_gw_node
*curr_gw
;
574 struct batadv_neigh_node
*router
;
575 struct batadv_neigh_ifinfo
*router_ifinfo
= NULL
;
578 router
= batadv_orig_router_get(gw_node
->orig_node
, BATADV_IF_DEFAULT
);
582 router_ifinfo
= batadv_neigh_ifinfo_get(router
, BATADV_IF_DEFAULT
);
586 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
588 ret
= seq_printf(seq
, "%s %pM (%3i) %pM [%10s]: %u.%u/%u.%u MBit\n",
589 (curr_gw
== gw_node
? "=>" : " "),
590 gw_node
->orig_node
->orig
,
591 router_ifinfo
->bat_iv
.tq_avg
, router
->addr
,
592 router
->if_incoming
->net_dev
->name
,
593 gw_node
->bandwidth_down
/ 10,
594 gw_node
->bandwidth_down
% 10,
595 gw_node
->bandwidth_up
/ 10,
596 gw_node
->bandwidth_up
% 10);
599 batadv_gw_node_free_ref(curr_gw
);
602 batadv_neigh_ifinfo_free_ref(router_ifinfo
);
604 batadv_neigh_node_free_ref(router
);
608 int batadv_gw_client_seq_print_text(struct seq_file
*seq
, void *offset
)
610 struct net_device
*net_dev
= (struct net_device
*)seq
->private;
611 struct batadv_priv
*bat_priv
= netdev_priv(net_dev
);
612 struct batadv_hard_iface
*primary_if
;
613 struct batadv_gw_node
*gw_node
;
616 primary_if
= batadv_seq_print_text_primary_if_get(seq
);
621 " %-12s (%s/%i) %17s [%10s]: advertised uplink bandwidth ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
622 "Gateway", "#", BATADV_TQ_MAX_VALUE
, "Nexthop", "outgoingIF",
623 BATADV_SOURCE_VERSION
, primary_if
->net_dev
->name
,
624 primary_if
->net_dev
->dev_addr
, net_dev
->name
);
627 hlist_for_each_entry_rcu(gw_node
, &bat_priv
->gw
.list
, list
) {
628 if (gw_node
->deleted
)
631 /* fails if orig_node has no router */
632 if (batadv_write_buffer_text(bat_priv
, seq
, gw_node
) < 0)
640 seq_puts(seq
, "No gateways in range ...\n");
644 batadv_hardif_free_ref(primary_if
);
649 * batadv_gw_dhcp_recipient_get - check if a packet is a DHCP message
650 * @skb: the packet to check
651 * @header_len: a pointer to the batman-adv header size
652 * @chaddr: buffer where the client address will be stored. Valid
653 * only if the function returns BATADV_DHCP_TO_CLIENT
656 * - BATADV_DHCP_NO if the packet is not a dhcp message or if there was an error
658 * - BATADV_DHCP_TO_SERVER if this is a message going to the DHCP server
659 * - BATADV_DHCP_TO_CLIENT if this is a message going to a DHCP client
661 * This function may re-allocate the data buffer of the skb passed as argument.
663 enum batadv_dhcp_recipient
664 batadv_gw_dhcp_recipient_get(struct sk_buff
*skb
, unsigned int *header_len
,
667 enum batadv_dhcp_recipient ret
= BATADV_DHCP_NO
;
668 struct ethhdr
*ethhdr
;
670 struct ipv6hdr
*ipv6hdr
;
671 struct udphdr
*udphdr
;
672 struct vlan_ethhdr
*vhdr
;
677 /* check for ethernet header */
678 if (!pskb_may_pull(skb
, *header_len
+ ETH_HLEN
))
679 return BATADV_DHCP_NO
;
681 ethhdr
= eth_hdr(skb
);
682 proto
= ethhdr
->h_proto
;
683 *header_len
+= ETH_HLEN
;
685 /* check for initial vlan header */
686 if (proto
== htons(ETH_P_8021Q
)) {
687 if (!pskb_may_pull(skb
, *header_len
+ VLAN_HLEN
))
688 return BATADV_DHCP_NO
;
690 vhdr
= vlan_eth_hdr(skb
);
691 proto
= vhdr
->h_vlan_encapsulated_proto
;
692 *header_len
+= VLAN_HLEN
;
695 /* check for ip header */
697 case htons(ETH_P_IP
):
698 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*iphdr
)))
699 return BATADV_DHCP_NO
;
701 iphdr
= (struct iphdr
*)(skb
->data
+ *header_len
);
702 *header_len
+= iphdr
->ihl
* 4;
704 /* check for udp header */
705 if (iphdr
->protocol
!= IPPROTO_UDP
)
706 return BATADV_DHCP_NO
;
709 case htons(ETH_P_IPV6
):
710 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*ipv6hdr
)))
711 return BATADV_DHCP_NO
;
713 ipv6hdr
= (struct ipv6hdr
*)(skb
->data
+ *header_len
);
714 *header_len
+= sizeof(*ipv6hdr
);
716 /* check for udp header */
717 if (ipv6hdr
->nexthdr
!= IPPROTO_UDP
)
718 return BATADV_DHCP_NO
;
722 return BATADV_DHCP_NO
;
725 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*udphdr
)))
726 return BATADV_DHCP_NO
;
728 /* skb->data might have been reallocated by pskb_may_pull() */
729 ethhdr
= eth_hdr(skb
);
730 if (ntohs(ethhdr
->h_proto
) == ETH_P_8021Q
)
731 ethhdr
= (struct ethhdr
*)(skb
->data
+ VLAN_HLEN
);
733 udphdr
= (struct udphdr
*)(skb
->data
+ *header_len
);
734 *header_len
+= sizeof(*udphdr
);
736 /* check for bootp port */
738 case htons(ETH_P_IP
):
739 if (udphdr
->dest
== htons(67))
740 ret
= BATADV_DHCP_TO_SERVER
;
741 else if (udphdr
->source
== htons(67))
742 ret
= BATADV_DHCP_TO_CLIENT
;
744 case htons(ETH_P_IPV6
):
745 if (udphdr
->dest
== htons(547))
746 ret
= BATADV_DHCP_TO_SERVER
;
747 else if (udphdr
->source
== htons(547))
748 ret
= BATADV_DHCP_TO_CLIENT
;
752 chaddr_offset
= *header_len
+ BATADV_DHCP_CHADDR_OFFSET
;
753 /* store the client address if the message is going to a client */
754 if (ret
== BATADV_DHCP_TO_CLIENT
&&
755 pskb_may_pull(skb
, chaddr_offset
+ ETH_ALEN
)) {
756 /* check if the DHCP packet carries an Ethernet DHCP */
757 p
= skb
->data
+ *header_len
+ BATADV_DHCP_HTYPE_OFFSET
;
758 if (*p
!= BATADV_DHCP_HTYPE_ETHERNET
)
759 return BATADV_DHCP_NO
;
761 /* check if the DHCP packet carries a valid Ethernet address */
762 p
= skb
->data
+ *header_len
+ BATADV_DHCP_HLEN_OFFSET
;
764 return BATADV_DHCP_NO
;
766 ether_addr_copy(chaddr
, skb
->data
+ chaddr_offset
);
772 * batadv_gw_out_of_range - check if the dhcp request destination is the best gw
773 * @bat_priv: the bat priv with all the soft interface information
774 * @skb: the outgoing packet
776 * Check if the skb is a DHCP request and if it is sent to the current best GW
777 * server. Due to topology changes it may be the case that the GW server
778 * previously selected is not the best one anymore.
780 * Returns true if the packet destination is unicast and it is not the best gw,
783 * This call might reallocate skb data.
784 * Must be invoked only when the DHCP packet is going TO a DHCP SERVER.
786 bool batadv_gw_out_of_range(struct batadv_priv
*bat_priv
,
789 struct batadv_neigh_node
*neigh_curr
= NULL
, *neigh_old
= NULL
;
790 struct batadv_orig_node
*orig_dst_node
= NULL
;
791 struct batadv_gw_node
*gw_node
= NULL
, *curr_gw
= NULL
;
792 struct batadv_neigh_ifinfo
*curr_ifinfo
, *old_ifinfo
;
793 struct ethhdr
*ethhdr
= (struct ethhdr
*)skb
->data
;
794 bool out_of_range
= false;
798 vid
= batadv_get_vid(skb
, 0);
800 orig_dst_node
= batadv_transtable_search(bat_priv
, ethhdr
->h_source
,
801 ethhdr
->h_dest
, vid
);
805 gw_node
= batadv_gw_node_get(bat_priv
, orig_dst_node
);
806 if (!gw_node
->bandwidth_down
== 0)
809 switch (atomic_read(&bat_priv
->gw_mode
)) {
810 case BATADV_GW_MODE_SERVER
:
811 /* If we are a GW then we are our best GW. We can artificially
812 * set the tq towards ourself as the maximum value
814 curr_tq_avg
= BATADV_TQ_MAX_VALUE
;
816 case BATADV_GW_MODE_CLIENT
:
817 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
821 /* packet is going to our gateway */
822 if (curr_gw
->orig_node
== orig_dst_node
)
825 /* If the dhcp packet has been sent to a different gw,
826 * we have to evaluate whether the old gw is still
829 neigh_curr
= batadv_find_router(bat_priv
, curr_gw
->orig_node
,
834 curr_ifinfo
= batadv_neigh_ifinfo_get(neigh_curr
,
839 curr_tq_avg
= curr_ifinfo
->bat_iv
.tq_avg
;
840 batadv_neigh_ifinfo_free_ref(curr_ifinfo
);
843 case BATADV_GW_MODE_OFF
:
848 neigh_old
= batadv_find_router(bat_priv
, orig_dst_node
, NULL
);
852 old_ifinfo
= batadv_neigh_ifinfo_get(neigh_old
, BATADV_IF_DEFAULT
);
856 if ((curr_tq_avg
- old_ifinfo
->bat_iv
.tq_avg
) > BATADV_GW_THRESHOLD
)
858 batadv_neigh_ifinfo_free_ref(old_ifinfo
);
862 batadv_orig_node_free_ref(orig_dst_node
);
864 batadv_gw_node_free_ref(curr_gw
);
866 batadv_gw_node_free_ref(gw_node
);
868 batadv_neigh_node_free_ref(neigh_old
);
870 batadv_neigh_node_free_ref(neigh_curr
);