1 /* Copyright (C) 2009-2015 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/list.h>
32 #include <linux/netdevice.h>
33 #include <linux/rculist.h>
34 #include <linux/rcupdate.h>
35 #include <linux/seq_file.h>
36 #include <linux/skbuff.h>
37 #include <linux/slab.h>
38 #include <linux/spinlock.h>
39 #include <linux/stddef.h>
40 #include <linux/udp.h>
42 #include "gateway_common.h"
43 #include "hard-interface.h"
44 #include "originator.h"
48 #include "translation-table.h"
50 /* These are the offsets of the "hw type" and "hw address length" in the dhcp
51 * packet starting at the beginning of the dhcp header
53 #define BATADV_DHCP_HTYPE_OFFSET 1
54 #define BATADV_DHCP_HLEN_OFFSET 2
55 /* Value of htype representing Ethernet */
56 #define BATADV_DHCP_HTYPE_ETHERNET 0x01
57 /* This is the offset of the "chaddr" field in the dhcp packet starting at the
58 * beginning of the dhcp header
60 #define BATADV_DHCP_CHADDR_OFFSET 28
62 static void batadv_gw_node_free_ref(struct batadv_gw_node
*gw_node
)
64 if (atomic_dec_and_test(&gw_node
->refcount
)) {
65 batadv_orig_node_free_ref(gw_node
->orig_node
);
66 kfree_rcu(gw_node
, rcu
);
70 static struct batadv_gw_node
*
71 batadv_gw_get_selected_gw_node(struct batadv_priv
*bat_priv
)
73 struct batadv_gw_node
*gw_node
;
76 gw_node
= rcu_dereference(bat_priv
->gw
.curr_gw
);
80 if (!atomic_inc_not_zero(&gw_node
->refcount
))
88 struct batadv_orig_node
*
89 batadv_gw_get_selected_orig(struct batadv_priv
*bat_priv
)
91 struct batadv_gw_node
*gw_node
;
92 struct batadv_orig_node
*orig_node
= NULL
;
94 gw_node
= batadv_gw_get_selected_gw_node(bat_priv
);
99 orig_node
= gw_node
->orig_node
;
103 if (!atomic_inc_not_zero(&orig_node
->refcount
))
110 batadv_gw_node_free_ref(gw_node
);
114 static void batadv_gw_select(struct batadv_priv
*bat_priv
,
115 struct batadv_gw_node
*new_gw_node
)
117 struct batadv_gw_node
*curr_gw_node
;
119 spin_lock_bh(&bat_priv
->gw
.list_lock
);
121 if (new_gw_node
&& !atomic_inc_not_zero(&new_gw_node
->refcount
))
124 curr_gw_node
= rcu_dereference_protected(bat_priv
->gw
.curr_gw
, 1);
125 rcu_assign_pointer(bat_priv
->gw
.curr_gw
, new_gw_node
);
128 batadv_gw_node_free_ref(curr_gw_node
);
130 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
134 * batadv_gw_reselect - force a gateway reselection
135 * @bat_priv: the bat priv with all the soft interface information
137 * Set a flag to remind the GW component to perform a new gateway reselection.
138 * However this function does not ensure that the current gateway is going to be
139 * deselected. The reselection mechanism may elect the same gateway once again.
141 * This means that invoking batadv_gw_reselect() does not guarantee a gateway
142 * change and therefore a uevent is not necessarily expected.
144 void batadv_gw_reselect(struct batadv_priv
*bat_priv
)
146 atomic_set(&bat_priv
->gw
.reselect
, 1);
149 static struct batadv_gw_node
*
150 batadv_gw_get_best_gw_node(struct batadv_priv
*bat_priv
)
152 struct batadv_neigh_node
*router
;
153 struct batadv_neigh_ifinfo
*router_ifinfo
;
154 struct batadv_gw_node
*gw_node
, *curr_gw
= NULL
;
155 u64 max_gw_factor
= 0;
156 u64 tmp_gw_factor
= 0;
159 struct batadv_orig_node
*orig_node
;
162 hlist_for_each_entry_rcu(gw_node
, &bat_priv
->gw
.list
, list
) {
163 orig_node
= gw_node
->orig_node
;
164 router
= batadv_orig_router_get(orig_node
, BATADV_IF_DEFAULT
);
168 router_ifinfo
= batadv_neigh_ifinfo_get(router
,
173 if (!atomic_inc_not_zero(&gw_node
->refcount
))
176 tq_avg
= router_ifinfo
->bat_iv
.tq_avg
;
178 switch (atomic_read(&bat_priv
->gw_sel_class
)) {
179 case 1: /* fast connection */
180 tmp_gw_factor
= tq_avg
* tq_avg
;
181 tmp_gw_factor
*= gw_node
->bandwidth_down
;
182 tmp_gw_factor
*= 100 * 100;
183 tmp_gw_factor
>>= 18;
185 if ((tmp_gw_factor
> max_gw_factor
) ||
186 ((tmp_gw_factor
== max_gw_factor
) &&
187 (tq_avg
> max_tq
))) {
189 batadv_gw_node_free_ref(curr_gw
);
191 atomic_inc(&curr_gw
->refcount
);
195 default: /* 2: stable connection (use best statistic)
196 * 3: fast-switch (use best statistic but change as
197 * soon as a better gateway appears)
198 * XX: late-switch (use best statistic but change as
199 * soon as a better gateway appears which has
200 * $routing_class more tq points)
202 if (tq_avg
> max_tq
) {
204 batadv_gw_node_free_ref(curr_gw
);
206 atomic_inc(&curr_gw
->refcount
);
214 if (tmp_gw_factor
> max_gw_factor
)
215 max_gw_factor
= tmp_gw_factor
;
217 batadv_gw_node_free_ref(gw_node
);
220 batadv_neigh_node_free_ref(router
);
222 batadv_neigh_ifinfo_free_ref(router_ifinfo
);
230 * batadv_gw_check_client_stop - check if client mode has been switched off
231 * @bat_priv: the bat priv with all the soft interface information
233 * This function assumes the caller has checked that the gw state *is actually
234 * changing*. This function is not supposed to be called when there is no state
237 void batadv_gw_check_client_stop(struct batadv_priv
*bat_priv
)
239 struct batadv_gw_node
*curr_gw
;
241 if (atomic_read(&bat_priv
->gw_mode
) != BATADV_GW_MODE_CLIENT
)
244 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
248 /* deselect the current gateway so that next time that client mode is
249 * enabled a proper GW_ADD event can be sent
251 batadv_gw_select(bat_priv
, NULL
);
253 /* if batman-adv is switching the gw client mode off and a gateway was
254 * already selected, send a DEL uevent
256 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_DEL
, NULL
);
258 batadv_gw_node_free_ref(curr_gw
);
261 void batadv_gw_election(struct batadv_priv
*bat_priv
)
263 struct batadv_gw_node
*curr_gw
= NULL
;
264 struct batadv_gw_node
*next_gw
= NULL
;
265 struct batadv_neigh_node
*router
= NULL
;
266 struct batadv_neigh_ifinfo
*router_ifinfo
= NULL
;
267 char gw_addr
[18] = { '\0' };
269 if (atomic_read(&bat_priv
->gw_mode
) != BATADV_GW_MODE_CLIENT
)
272 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
274 if (!batadv_atomic_dec_not_zero(&bat_priv
->gw
.reselect
) && curr_gw
)
277 next_gw
= batadv_gw_get_best_gw_node(bat_priv
);
279 if (curr_gw
== next_gw
)
283 sprintf(gw_addr
, "%pM", next_gw
->orig_node
->orig
);
285 router
= batadv_orig_router_get(next_gw
->orig_node
,
288 batadv_gw_reselect(bat_priv
);
292 router_ifinfo
= batadv_neigh_ifinfo_get(router
,
294 if (!router_ifinfo
) {
295 batadv_gw_reselect(bat_priv
);
300 if ((curr_gw
) && (!next_gw
)) {
301 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
302 "Removing selected gateway - no gateway in range\n");
303 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_DEL
,
305 } else if ((!curr_gw
) && (next_gw
)) {
306 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
307 "Adding route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
308 next_gw
->orig_node
->orig
,
309 next_gw
->bandwidth_down
/ 10,
310 next_gw
->bandwidth_down
% 10,
311 next_gw
->bandwidth_up
/ 10,
312 next_gw
->bandwidth_up
% 10,
313 router_ifinfo
->bat_iv
.tq_avg
);
314 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_ADD
,
317 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
318 "Changing route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
319 next_gw
->orig_node
->orig
,
320 next_gw
->bandwidth_down
/ 10,
321 next_gw
->bandwidth_down
% 10,
322 next_gw
->bandwidth_up
/ 10,
323 next_gw
->bandwidth_up
% 10,
324 router_ifinfo
->bat_iv
.tq_avg
);
325 batadv_throw_uevent(bat_priv
, BATADV_UEV_GW
, BATADV_UEV_CHANGE
,
329 batadv_gw_select(bat_priv
, next_gw
);
333 batadv_gw_node_free_ref(curr_gw
);
335 batadv_gw_node_free_ref(next_gw
);
337 batadv_neigh_node_free_ref(router
);
339 batadv_neigh_ifinfo_free_ref(router_ifinfo
);
342 void batadv_gw_check_election(struct batadv_priv
*bat_priv
,
343 struct batadv_orig_node
*orig_node
)
345 struct batadv_neigh_ifinfo
*router_orig_tq
= NULL
;
346 struct batadv_neigh_ifinfo
*router_gw_tq
= NULL
;
347 struct batadv_orig_node
*curr_gw_orig
;
348 struct batadv_neigh_node
*router_gw
= NULL
;
349 struct batadv_neigh_node
*router_orig
= NULL
;
350 u8 gw_tq_avg
, orig_tq_avg
;
352 curr_gw_orig
= batadv_gw_get_selected_orig(bat_priv
);
356 router_gw
= batadv_orig_router_get(curr_gw_orig
, BATADV_IF_DEFAULT
);
360 router_gw_tq
= batadv_neigh_ifinfo_get(router_gw
,
365 /* this node already is the gateway */
366 if (curr_gw_orig
== orig_node
)
369 router_orig
= batadv_orig_router_get(orig_node
, BATADV_IF_DEFAULT
);
373 router_orig_tq
= batadv_neigh_ifinfo_get(router_orig
,
378 gw_tq_avg
= router_gw_tq
->bat_iv
.tq_avg
;
379 orig_tq_avg
= router_orig_tq
->bat_iv
.tq_avg
;
381 /* the TQ value has to be better */
382 if (orig_tq_avg
< gw_tq_avg
)
385 /* if the routing class is greater than 3 the value tells us how much
386 * greater the TQ value of the new gateway must be
388 if ((atomic_read(&bat_priv
->gw_sel_class
) > 3) &&
389 (orig_tq_avg
- gw_tq_avg
< atomic_read(&bat_priv
->gw_sel_class
)))
392 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
393 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
394 gw_tq_avg
, orig_tq_avg
);
397 batadv_gw_reselect(bat_priv
);
400 batadv_orig_node_free_ref(curr_gw_orig
);
402 batadv_neigh_node_free_ref(router_gw
);
404 batadv_neigh_node_free_ref(router_orig
);
406 batadv_neigh_ifinfo_free_ref(router_gw_tq
);
408 batadv_neigh_ifinfo_free_ref(router_orig_tq
);
412 * batadv_gw_node_add - add gateway node to list of available gateways
413 * @bat_priv: the bat priv with all the soft interface information
414 * @orig_node: originator announcing gateway capabilities
415 * @gateway: announced bandwidth information
417 static void batadv_gw_node_add(struct batadv_priv
*bat_priv
,
418 struct batadv_orig_node
*orig_node
,
419 struct batadv_tvlv_gateway_data
*gateway
)
421 struct batadv_gw_node
*gw_node
;
423 if (gateway
->bandwidth_down
== 0)
426 if (!atomic_inc_not_zero(&orig_node
->refcount
))
429 gw_node
= kzalloc(sizeof(*gw_node
), GFP_ATOMIC
);
431 batadv_orig_node_free_ref(orig_node
);
435 INIT_HLIST_NODE(&gw_node
->list
);
436 gw_node
->orig_node
= orig_node
;
437 gw_node
->bandwidth_down
= ntohl(gateway
->bandwidth_down
);
438 gw_node
->bandwidth_up
= ntohl(gateway
->bandwidth_up
);
439 atomic_set(&gw_node
->refcount
, 1);
441 spin_lock_bh(&bat_priv
->gw
.list_lock
);
442 hlist_add_head_rcu(&gw_node
->list
, &bat_priv
->gw
.list
);
443 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
445 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
446 "Found new gateway %pM -> gw bandwidth: %u.%u/%u.%u MBit\n",
448 ntohl(gateway
->bandwidth_down
) / 10,
449 ntohl(gateway
->bandwidth_down
) % 10,
450 ntohl(gateway
->bandwidth_up
) / 10,
451 ntohl(gateway
->bandwidth_up
) % 10);
455 * batadv_gw_node_get - retrieve gateway node from list of available gateways
456 * @bat_priv: the bat priv with all the soft interface information
457 * @orig_node: originator announcing gateway capabilities
459 * Returns gateway node if found or NULL otherwise.
461 static struct batadv_gw_node
*
462 batadv_gw_node_get(struct batadv_priv
*bat_priv
,
463 struct batadv_orig_node
*orig_node
)
465 struct batadv_gw_node
*gw_node_tmp
, *gw_node
= NULL
;
468 hlist_for_each_entry_rcu(gw_node_tmp
, &bat_priv
->gw
.list
, list
) {
469 if (gw_node_tmp
->orig_node
!= orig_node
)
472 if (!atomic_inc_not_zero(&gw_node_tmp
->refcount
))
475 gw_node
= gw_node_tmp
;
484 * batadv_gw_node_update - update list of available gateways with changed
485 * bandwidth information
486 * @bat_priv: the bat priv with all the soft interface information
487 * @orig_node: originator announcing gateway capabilities
488 * @gateway: announced bandwidth information
490 void batadv_gw_node_update(struct batadv_priv
*bat_priv
,
491 struct batadv_orig_node
*orig_node
,
492 struct batadv_tvlv_gateway_data
*gateway
)
494 struct batadv_gw_node
*gw_node
, *curr_gw
= NULL
;
496 gw_node
= batadv_gw_node_get(bat_priv
, orig_node
);
498 batadv_gw_node_add(bat_priv
, orig_node
, gateway
);
502 if ((gw_node
->bandwidth_down
== ntohl(gateway
->bandwidth_down
)) &&
503 (gw_node
->bandwidth_up
== ntohl(gateway
->bandwidth_up
)))
506 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
507 "Gateway bandwidth of originator %pM changed from %u.%u/%u.%u MBit to %u.%u/%u.%u MBit\n",
509 gw_node
->bandwidth_down
/ 10,
510 gw_node
->bandwidth_down
% 10,
511 gw_node
->bandwidth_up
/ 10,
512 gw_node
->bandwidth_up
% 10,
513 ntohl(gateway
->bandwidth_down
) / 10,
514 ntohl(gateway
->bandwidth_down
) % 10,
515 ntohl(gateway
->bandwidth_up
) / 10,
516 ntohl(gateway
->bandwidth_up
) % 10);
518 gw_node
->bandwidth_down
= ntohl(gateway
->bandwidth_down
);
519 gw_node
->bandwidth_up
= ntohl(gateway
->bandwidth_up
);
521 if (ntohl(gateway
->bandwidth_down
) == 0) {
522 batadv_dbg(BATADV_DBG_BATMAN
, bat_priv
,
523 "Gateway %pM removed from gateway list\n",
526 /* Note: We don't need a NULL check here, since curr_gw never
529 spin_lock_bh(&bat_priv
->gw
.list_lock
);
530 if (!hlist_unhashed(&gw_node
->list
)) {
531 hlist_del_init_rcu(&gw_node
->list
);
532 batadv_gw_node_free_ref(gw_node
);
534 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
536 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
537 if (gw_node
== curr_gw
)
538 batadv_gw_reselect(bat_priv
);
541 batadv_gw_node_free_ref(curr_gw
);
546 batadv_gw_node_free_ref(gw_node
);
549 void batadv_gw_node_delete(struct batadv_priv
*bat_priv
,
550 struct batadv_orig_node
*orig_node
)
552 struct batadv_tvlv_gateway_data gateway
;
554 gateway
.bandwidth_down
= 0;
555 gateway
.bandwidth_up
= 0;
557 batadv_gw_node_update(bat_priv
, orig_node
, &gateway
);
560 void batadv_gw_node_free(struct batadv_priv
*bat_priv
)
562 struct batadv_gw_node
*gw_node
;
563 struct hlist_node
*node_tmp
;
565 spin_lock_bh(&bat_priv
->gw
.list_lock
);
566 hlist_for_each_entry_safe(gw_node
, node_tmp
,
567 &bat_priv
->gw
.list
, list
) {
568 hlist_del_init_rcu(&gw_node
->list
);
569 batadv_gw_node_free_ref(gw_node
);
571 spin_unlock_bh(&bat_priv
->gw
.list_lock
);
574 /* fails if orig_node has no router */
575 static int batadv_write_buffer_text(struct batadv_priv
*bat_priv
,
576 struct seq_file
*seq
,
577 const struct batadv_gw_node
*gw_node
)
579 struct batadv_gw_node
*curr_gw
;
580 struct batadv_neigh_node
*router
;
581 struct batadv_neigh_ifinfo
*router_ifinfo
= NULL
;
584 router
= batadv_orig_router_get(gw_node
->orig_node
, BATADV_IF_DEFAULT
);
588 router_ifinfo
= batadv_neigh_ifinfo_get(router
, BATADV_IF_DEFAULT
);
592 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
594 seq_printf(seq
, "%s %pM (%3i) %pM [%10s]: %u.%u/%u.%u MBit\n",
595 (curr_gw
== gw_node
? "=>" : " "),
596 gw_node
->orig_node
->orig
,
597 router_ifinfo
->bat_iv
.tq_avg
, router
->addr
,
598 router
->if_incoming
->net_dev
->name
,
599 gw_node
->bandwidth_down
/ 10,
600 gw_node
->bandwidth_down
% 10,
601 gw_node
->bandwidth_up
/ 10,
602 gw_node
->bandwidth_up
% 10);
603 ret
= seq_has_overflowed(seq
) ? -1 : 0;
606 batadv_gw_node_free_ref(curr_gw
);
609 batadv_neigh_ifinfo_free_ref(router_ifinfo
);
611 batadv_neigh_node_free_ref(router
);
615 int batadv_gw_client_seq_print_text(struct seq_file
*seq
, void *offset
)
617 struct net_device
*net_dev
= (struct net_device
*)seq
->private;
618 struct batadv_priv
*bat_priv
= netdev_priv(net_dev
);
619 struct batadv_hard_iface
*primary_if
;
620 struct batadv_gw_node
*gw_node
;
623 primary_if
= batadv_seq_print_text_primary_if_get(seq
);
628 " %-12s (%s/%i) %17s [%10s]: advertised uplink bandwidth ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
629 "Gateway", "#", BATADV_TQ_MAX_VALUE
, "Nexthop", "outgoingIF",
630 BATADV_SOURCE_VERSION
, primary_if
->net_dev
->name
,
631 primary_if
->net_dev
->dev_addr
, net_dev
->name
);
634 hlist_for_each_entry_rcu(gw_node
, &bat_priv
->gw
.list
, list
) {
635 /* fails if orig_node has no router */
636 if (batadv_write_buffer_text(bat_priv
, seq
, gw_node
) < 0)
644 seq_puts(seq
, "No gateways in range ...\n");
648 batadv_hardif_free_ref(primary_if
);
653 * batadv_gw_dhcp_recipient_get - check if a packet is a DHCP message
654 * @skb: the packet to check
655 * @header_len: a pointer to the batman-adv header size
656 * @chaddr: buffer where the client address will be stored. Valid
657 * only if the function returns BATADV_DHCP_TO_CLIENT
660 * - BATADV_DHCP_NO if the packet is not a dhcp message or if there was an error
662 * - BATADV_DHCP_TO_SERVER if this is a message going to the DHCP server
663 * - BATADV_DHCP_TO_CLIENT if this is a message going to a DHCP client
665 * This function may re-allocate the data buffer of the skb passed as argument.
667 enum batadv_dhcp_recipient
668 batadv_gw_dhcp_recipient_get(struct sk_buff
*skb
, unsigned int *header_len
,
671 enum batadv_dhcp_recipient ret
= BATADV_DHCP_NO
;
672 struct ethhdr
*ethhdr
;
674 struct ipv6hdr
*ipv6hdr
;
675 struct udphdr
*udphdr
;
676 struct vlan_ethhdr
*vhdr
;
681 /* check for ethernet header */
682 if (!pskb_may_pull(skb
, *header_len
+ ETH_HLEN
))
683 return BATADV_DHCP_NO
;
685 ethhdr
= eth_hdr(skb
);
686 proto
= ethhdr
->h_proto
;
687 *header_len
+= ETH_HLEN
;
689 /* check for initial vlan header */
690 if (proto
== htons(ETH_P_8021Q
)) {
691 if (!pskb_may_pull(skb
, *header_len
+ VLAN_HLEN
))
692 return BATADV_DHCP_NO
;
694 vhdr
= vlan_eth_hdr(skb
);
695 proto
= vhdr
->h_vlan_encapsulated_proto
;
696 *header_len
+= VLAN_HLEN
;
699 /* check for ip header */
701 case htons(ETH_P_IP
):
702 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*iphdr
)))
703 return BATADV_DHCP_NO
;
705 iphdr
= (struct iphdr
*)(skb
->data
+ *header_len
);
706 *header_len
+= iphdr
->ihl
* 4;
708 /* check for udp header */
709 if (iphdr
->protocol
!= IPPROTO_UDP
)
710 return BATADV_DHCP_NO
;
713 case htons(ETH_P_IPV6
):
714 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*ipv6hdr
)))
715 return BATADV_DHCP_NO
;
717 ipv6hdr
= (struct ipv6hdr
*)(skb
->data
+ *header_len
);
718 *header_len
+= sizeof(*ipv6hdr
);
720 /* check for udp header */
721 if (ipv6hdr
->nexthdr
!= IPPROTO_UDP
)
722 return BATADV_DHCP_NO
;
726 return BATADV_DHCP_NO
;
729 if (!pskb_may_pull(skb
, *header_len
+ sizeof(*udphdr
)))
730 return BATADV_DHCP_NO
;
732 udphdr
= (struct udphdr
*)(skb
->data
+ *header_len
);
733 *header_len
+= sizeof(*udphdr
);
735 /* check for bootp port */
737 case htons(ETH_P_IP
):
738 if (udphdr
->dest
== htons(67))
739 ret
= BATADV_DHCP_TO_SERVER
;
740 else if (udphdr
->source
== htons(67))
741 ret
= BATADV_DHCP_TO_CLIENT
;
743 case htons(ETH_P_IPV6
):
744 if (udphdr
->dest
== htons(547))
745 ret
= BATADV_DHCP_TO_SERVER
;
746 else if (udphdr
->source
== htons(547))
747 ret
= BATADV_DHCP_TO_CLIENT
;
751 chaddr_offset
= *header_len
+ BATADV_DHCP_CHADDR_OFFSET
;
752 /* store the client address if the message is going to a client */
753 if (ret
== BATADV_DHCP_TO_CLIENT
&&
754 pskb_may_pull(skb
, chaddr_offset
+ ETH_ALEN
)) {
755 /* check if the DHCP packet carries an Ethernet DHCP */
756 p
= skb
->data
+ *header_len
+ BATADV_DHCP_HTYPE_OFFSET
;
757 if (*p
!= BATADV_DHCP_HTYPE_ETHERNET
)
758 return BATADV_DHCP_NO
;
760 /* check if the DHCP packet carries a valid Ethernet address */
761 p
= skb
->data
+ *header_len
+ BATADV_DHCP_HLEN_OFFSET
;
763 return BATADV_DHCP_NO
;
765 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
;
790 struct batadv_neigh_node
*neigh_old
= NULL
;
791 struct batadv_orig_node
*orig_dst_node
= NULL
;
792 struct batadv_gw_node
*gw_node
= NULL
;
793 struct batadv_gw_node
*curr_gw
= NULL
;
794 struct batadv_neigh_ifinfo
*curr_ifinfo
, *old_ifinfo
;
795 struct ethhdr
*ethhdr
= (struct ethhdr
*)skb
->data
;
796 bool out_of_range
= false;
800 vid
= batadv_get_vid(skb
, 0);
802 orig_dst_node
= batadv_transtable_search(bat_priv
, ethhdr
->h_source
,
803 ethhdr
->h_dest
, vid
);
807 gw_node
= batadv_gw_node_get(bat_priv
, orig_dst_node
);
811 switch (atomic_read(&bat_priv
->gw_mode
)) {
812 case BATADV_GW_MODE_SERVER
:
813 /* If we are a GW then we are our best GW. We can artificially
814 * set the tq towards ourself as the maximum value
816 curr_tq_avg
= BATADV_TQ_MAX_VALUE
;
818 case BATADV_GW_MODE_CLIENT
:
819 curr_gw
= batadv_gw_get_selected_gw_node(bat_priv
);
823 /* packet is going to our gateway */
824 if (curr_gw
->orig_node
== orig_dst_node
)
827 /* If the dhcp packet has been sent to a different gw,
828 * we have to evaluate whether the old gw is still
831 neigh_curr
= batadv_find_router(bat_priv
, curr_gw
->orig_node
,
836 curr_ifinfo
= batadv_neigh_ifinfo_get(neigh_curr
,
841 curr_tq_avg
= curr_ifinfo
->bat_iv
.tq_avg
;
842 batadv_neigh_ifinfo_free_ref(curr_ifinfo
);
845 case BATADV_GW_MODE_OFF
:
850 neigh_old
= batadv_find_router(bat_priv
, orig_dst_node
, NULL
);
854 old_ifinfo
= batadv_neigh_ifinfo_get(neigh_old
, BATADV_IF_DEFAULT
);
858 if ((curr_tq_avg
- old_ifinfo
->bat_iv
.tq_avg
) > BATADV_GW_THRESHOLD
)
860 batadv_neigh_ifinfo_free_ref(old_ifinfo
);
864 batadv_orig_node_free_ref(orig_dst_node
);
866 batadv_gw_node_free_ref(curr_gw
);
868 batadv_gw_node_free_ref(gw_node
);
870 batadv_neigh_node_free_ref(neigh_old
);
872 batadv_neigh_node_free_ref(neigh_curr
);