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 hlist_del_init_rcu(&gw_node->list);
531 spin_unlock_bh(&bat_priv->gw.list_lock);
533 batadv_gw_node_free_ref(gw_node);
535 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
536 if (gw_node == curr_gw)
537 batadv_gw_reselect(bat_priv);
540 batadv_gw_node_free_ref(curr_gw);
545 batadv_gw_node_free_ref(gw_node);
548 void batadv_gw_node_delete(struct batadv_priv *bat_priv,
549 struct batadv_orig_node *orig_node)
551 struct batadv_tvlv_gateway_data gateway;
553 gateway.bandwidth_down = 0;
554 gateway.bandwidth_up = 0;
556 batadv_gw_node_update(bat_priv, orig_node, &gateway);
559 void batadv_gw_node_free(struct batadv_priv *bat_priv)
561 struct batadv_gw_node *gw_node;
562 struct hlist_node *node_tmp;
564 spin_lock_bh(&bat_priv->gw.list_lock);
565 hlist_for_each_entry_safe(gw_node, node_tmp,
566 &bat_priv->gw.list, list) {
567 hlist_del_init_rcu(&gw_node->list);
568 batadv_gw_node_free_ref(gw_node);
570 spin_unlock_bh(&bat_priv->gw.list_lock);
573 /* fails if orig_node has no router */
574 static int batadv_write_buffer_text(struct batadv_priv *bat_priv,
575 struct seq_file *seq,
576 const struct batadv_gw_node *gw_node)
578 struct batadv_gw_node *curr_gw;
579 struct batadv_neigh_node *router;
580 struct batadv_neigh_ifinfo *router_ifinfo = NULL;
583 router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
587 router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
591 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
593 seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %u.%u/%u.%u MBit\n",
594 (curr_gw == gw_node ? "=>" : " "),
595 gw_node->orig_node->orig,
596 router_ifinfo->bat_iv.tq_avg, router->addr,
597 router->if_incoming->net_dev->name,
598 gw_node->bandwidth_down / 10,
599 gw_node->bandwidth_down % 10,
600 gw_node->bandwidth_up / 10,
601 gw_node->bandwidth_up % 10);
602 ret = seq_has_overflowed(seq) ? -1 : 0;
605 batadv_gw_node_free_ref(curr_gw);
608 batadv_neigh_ifinfo_free_ref(router_ifinfo);
610 batadv_neigh_node_free_ref(router);
614 int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset)
616 struct net_device *net_dev = (struct net_device *)seq->private;
617 struct batadv_priv *bat_priv = netdev_priv(net_dev);
618 struct batadv_hard_iface *primary_if;
619 struct batadv_gw_node *gw_node;
622 primary_if = batadv_seq_print_text_primary_if_get(seq);
627 " %-12s (%s/%i) %17s [%10s]: advertised uplink bandwidth ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
628 "Gateway", "#", BATADV_TQ_MAX_VALUE, "Nexthop", "outgoingIF",
629 BATADV_SOURCE_VERSION, primary_if->net_dev->name,
630 primary_if->net_dev->dev_addr, net_dev->name);
633 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
634 /* fails if orig_node has no router */
635 if (batadv_write_buffer_text(bat_priv, seq, gw_node) < 0)
643 seq_puts(seq, "No gateways in range ...\n");
647 batadv_hardif_free_ref(primary_if);
652 * batadv_gw_dhcp_recipient_get - check if a packet is a DHCP message
653 * @skb: the packet to check
654 * @header_len: a pointer to the batman-adv header size
655 * @chaddr: buffer where the client address will be stored. Valid
656 * only if the function returns BATADV_DHCP_TO_CLIENT
659 * - BATADV_DHCP_NO if the packet is not a dhcp message or if there was an error
661 * - BATADV_DHCP_TO_SERVER if this is a message going to the DHCP server
662 * - BATADV_DHCP_TO_CLIENT if this is a message going to a DHCP client
664 * This function may re-allocate the data buffer of the skb passed as argument.
666 enum batadv_dhcp_recipient
667 batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len,
670 enum batadv_dhcp_recipient ret = BATADV_DHCP_NO;
671 struct ethhdr *ethhdr;
673 struct ipv6hdr *ipv6hdr;
674 struct udphdr *udphdr;
675 struct vlan_ethhdr *vhdr;
680 /* check for ethernet header */
681 if (!pskb_may_pull(skb, *header_len + ETH_HLEN))
682 return BATADV_DHCP_NO;
684 ethhdr = eth_hdr(skb);
685 proto = ethhdr->h_proto;
686 *header_len += ETH_HLEN;
688 /* check for initial vlan header */
689 if (proto == htons(ETH_P_8021Q)) {
690 if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))
691 return BATADV_DHCP_NO;
693 vhdr = vlan_eth_hdr(skb);
694 proto = vhdr->h_vlan_encapsulated_proto;
695 *header_len += VLAN_HLEN;
698 /* check for ip header */
700 case htons(ETH_P_IP):
701 if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr)))
702 return BATADV_DHCP_NO;
704 iphdr = (struct iphdr *)(skb->data + *header_len);
705 *header_len += iphdr->ihl * 4;
707 /* check for udp header */
708 if (iphdr->protocol != IPPROTO_UDP)
709 return BATADV_DHCP_NO;
712 case htons(ETH_P_IPV6):
713 if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr)))
714 return BATADV_DHCP_NO;
716 ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len);
717 *header_len += sizeof(*ipv6hdr);
719 /* check for udp header */
720 if (ipv6hdr->nexthdr != IPPROTO_UDP)
721 return BATADV_DHCP_NO;
725 return BATADV_DHCP_NO;
728 if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr)))
729 return BATADV_DHCP_NO;
731 udphdr = (struct udphdr *)(skb->data + *header_len);
732 *header_len += sizeof(*udphdr);
734 /* check for bootp port */
736 case htons(ETH_P_IP):
737 if (udphdr->dest == htons(67))
738 ret = BATADV_DHCP_TO_SERVER;
739 else if (udphdr->source == htons(67))
740 ret = BATADV_DHCP_TO_CLIENT;
742 case htons(ETH_P_IPV6):
743 if (udphdr->dest == htons(547))
744 ret = BATADV_DHCP_TO_SERVER;
745 else if (udphdr->source == htons(547))
746 ret = BATADV_DHCP_TO_CLIENT;
750 chaddr_offset = *header_len + BATADV_DHCP_CHADDR_OFFSET;
751 /* store the client address if the message is going to a client */
752 if (ret == BATADV_DHCP_TO_CLIENT &&
753 pskb_may_pull(skb, chaddr_offset + ETH_ALEN)) {
754 /* check if the DHCP packet carries an Ethernet DHCP */
755 p = skb->data + *header_len + BATADV_DHCP_HTYPE_OFFSET;
756 if (*p != BATADV_DHCP_HTYPE_ETHERNET)
757 return BATADV_DHCP_NO;
759 /* check if the DHCP packet carries a valid Ethernet address */
760 p = skb->data + *header_len + BATADV_DHCP_HLEN_OFFSET;
762 return BATADV_DHCP_NO;
764 ether_addr_copy(chaddr, skb->data + chaddr_offset);
771 * batadv_gw_out_of_range - check if the dhcp request destination is the best gw
772 * @bat_priv: the bat priv with all the soft interface information
773 * @skb: the outgoing packet
775 * Check if the skb is a DHCP request and if it is sent to the current best GW
776 * server. Due to topology changes it may be the case that the GW server
777 * previously selected is not the best one anymore.
779 * Returns true if the packet destination is unicast and it is not the best gw,
782 * This call might reallocate skb data.
783 * Must be invoked only when the DHCP packet is going TO a DHCP SERVER.
785 bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
788 struct batadv_neigh_node *neigh_curr = NULL;
789 struct batadv_neigh_node *neigh_old = NULL;
790 struct batadv_orig_node *orig_dst_node = NULL;
791 struct batadv_gw_node *gw_node = NULL;
792 struct batadv_gw_node *curr_gw = NULL;
793 struct batadv_neigh_ifinfo *curr_ifinfo, *old_ifinfo;
794 struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
795 bool out_of_range = false;
799 vid = batadv_get_vid(skb, 0);
801 orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
802 ethhdr->h_dest, vid);
806 gw_node = batadv_gw_node_get(bat_priv, orig_dst_node);
810 switch (atomic_read(&bat_priv->gw_mode)) {
811 case BATADV_GW_MODE_SERVER:
812 /* If we are a GW then we are our best GW. We can artificially
813 * set the tq towards ourself as the maximum value
815 curr_tq_avg = BATADV_TQ_MAX_VALUE;
817 case BATADV_GW_MODE_CLIENT:
818 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
822 /* packet is going to our gateway */
823 if (curr_gw->orig_node == orig_dst_node)
826 /* If the dhcp packet has been sent to a different gw,
827 * we have to evaluate whether the old gw is still
830 neigh_curr = batadv_find_router(bat_priv, curr_gw->orig_node,
835 curr_ifinfo = batadv_neigh_ifinfo_get(neigh_curr,
840 curr_tq_avg = curr_ifinfo->bat_iv.tq_avg;
841 batadv_neigh_ifinfo_free_ref(curr_ifinfo);
844 case BATADV_GW_MODE_OFF:
849 neigh_old = batadv_find_router(bat_priv, orig_dst_node, NULL);
853 old_ifinfo = batadv_neigh_ifinfo_get(neigh_old, BATADV_IF_DEFAULT);
857 if ((curr_tq_avg - old_ifinfo->bat_iv.tq_avg) > BATADV_GW_THRESHOLD)
859 batadv_neigh_ifinfo_free_ref(old_ifinfo);
863 batadv_orig_node_free_ref(orig_dst_node);
865 batadv_gw_node_free_ref(curr_gw);
867 batadv_gw_node_free_ref(gw_node);
869 batadv_neigh_node_free_ref(neigh_old);
871 batadv_neigh_node_free_ref(neigh_curr);