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/jiffies.h>
31 #include <linux/kernel.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
63 static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node)
65 if (atomic_dec_and_test(&gw_node->refcount)) {
66 batadv_orig_node_free_ref(gw_node->orig_node);
67 kfree_rcu(gw_node, rcu);
71 static struct batadv_gw_node *
72 batadv_gw_get_selected_gw_node(struct batadv_priv *bat_priv)
74 struct batadv_gw_node *gw_node;
77 gw_node = rcu_dereference(bat_priv->gw.curr_gw);
81 if (!atomic_inc_not_zero(&gw_node->refcount))
89 struct batadv_orig_node *
90 batadv_gw_get_selected_orig(struct batadv_priv *bat_priv)
92 struct batadv_gw_node *gw_node;
93 struct batadv_orig_node *orig_node = NULL;
95 gw_node = batadv_gw_get_selected_gw_node(bat_priv);
100 orig_node = gw_node->orig_node;
104 if (!atomic_inc_not_zero(&orig_node->refcount))
111 batadv_gw_node_free_ref(gw_node);
115 static void batadv_gw_select(struct batadv_priv *bat_priv,
116 struct batadv_gw_node *new_gw_node)
118 struct batadv_gw_node *curr_gw_node;
120 spin_lock_bh(&bat_priv->gw.list_lock);
122 if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
125 curr_gw_node = rcu_dereference_protected(bat_priv->gw.curr_gw, 1);
126 rcu_assign_pointer(bat_priv->gw.curr_gw, new_gw_node);
129 batadv_gw_node_free_ref(curr_gw_node);
131 spin_unlock_bh(&bat_priv->gw.list_lock);
135 * batadv_gw_reselect - force a gateway reselection
136 * @bat_priv: the bat priv with all the soft interface information
138 * Set a flag to remind the GW component to perform a new gateway reselection.
139 * However this function does not ensure that the current gateway is going to be
140 * deselected. The reselection mechanism may elect the same gateway once again.
142 * This means that invoking batadv_gw_reselect() does not guarantee a gateway
143 * change and therefore a uevent is not necessarily expected.
145 void batadv_gw_reselect(struct batadv_priv *bat_priv)
147 atomic_set(&bat_priv->gw.reselect, 1);
150 static struct batadv_gw_node *
151 batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
153 struct batadv_neigh_node *router;
154 struct batadv_neigh_ifinfo *router_ifinfo;
155 struct batadv_gw_node *gw_node, *curr_gw = NULL;
156 uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
160 struct batadv_orig_node *orig_node;
162 gw_divisor = BATADV_TQ_LOCAL_WINDOW_SIZE * BATADV_TQ_LOCAL_WINDOW_SIZE;
166 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
167 if (gw_node->deleted)
170 orig_node = gw_node->orig_node;
171 router = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
175 router_ifinfo = batadv_neigh_ifinfo_get(router,
180 if (!atomic_inc_not_zero(&gw_node->refcount))
183 tq_avg = router_ifinfo->bat_iv.tq_avg;
185 switch (atomic_read(&bat_priv->gw_sel_class)) {
186 case 1: /* fast connection */
187 tmp_gw_factor = tq_avg * tq_avg;
188 tmp_gw_factor *= gw_node->bandwidth_down;
189 tmp_gw_factor *= 100 * 100;
190 tmp_gw_factor /= gw_divisor;
192 if ((tmp_gw_factor > max_gw_factor) ||
193 ((tmp_gw_factor == max_gw_factor) &&
194 (tq_avg > max_tq))) {
196 batadv_gw_node_free_ref(curr_gw);
198 atomic_inc(&curr_gw->refcount);
202 default: /* 2: stable connection (use best statistic)
203 * 3: fast-switch (use best statistic but change as
204 * soon as a better gateway appears)
205 * XX: late-switch (use best statistic but change as
206 * soon as a better gateway appears which has
207 * $routing_class more tq points)
209 if (tq_avg > max_tq) {
211 batadv_gw_node_free_ref(curr_gw);
213 atomic_inc(&curr_gw->refcount);
221 if (tmp_gw_factor > max_gw_factor)
222 max_gw_factor = tmp_gw_factor;
224 batadv_gw_node_free_ref(gw_node);
227 batadv_neigh_node_free_ref(router);
229 batadv_neigh_ifinfo_free_ref(router_ifinfo);
237 * batadv_gw_check_client_stop - check if client mode has been switched off
238 * @bat_priv: the bat priv with all the soft interface information
240 * This function assumes the caller has checked that the gw state *is actually
241 * changing*. This function is not supposed to be called when there is no state
244 void batadv_gw_check_client_stop(struct batadv_priv *bat_priv)
246 struct batadv_gw_node *curr_gw;
248 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
251 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
255 /* deselect the current gateway so that next time that client mode is
256 * enabled a proper GW_ADD event can be sent
258 batadv_gw_select(bat_priv, NULL);
260 /* if batman-adv is switching the gw client mode off and a gateway was
261 * already selected, send a DEL uevent
263 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL, NULL);
265 batadv_gw_node_free_ref(curr_gw);
268 void batadv_gw_election(struct batadv_priv *bat_priv)
270 struct batadv_gw_node *curr_gw = NULL, *next_gw = NULL;
271 struct batadv_neigh_node *router = NULL;
272 struct batadv_neigh_ifinfo *router_ifinfo = NULL;
273 char gw_addr[18] = { '\0' };
275 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
278 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
280 if (!batadv_atomic_dec_not_zero(&bat_priv->gw.reselect) && curr_gw)
283 next_gw = batadv_gw_get_best_gw_node(bat_priv);
285 if (curr_gw == next_gw)
289 sprintf(gw_addr, "%pM", next_gw->orig_node->orig);
291 router = batadv_orig_router_get(next_gw->orig_node,
294 batadv_gw_reselect(bat_priv);
298 router_ifinfo = batadv_neigh_ifinfo_get(router,
300 if (!router_ifinfo) {
301 batadv_gw_reselect(bat_priv);
306 if ((curr_gw) && (!next_gw)) {
307 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
308 "Removing selected gateway - no gateway in range\n");
309 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL,
311 } else if ((!curr_gw) && (next_gw)) {
312 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
313 "Adding route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
314 next_gw->orig_node->orig,
315 next_gw->bandwidth_down / 10,
316 next_gw->bandwidth_down % 10,
317 next_gw->bandwidth_up / 10,
318 next_gw->bandwidth_up % 10,
319 router_ifinfo->bat_iv.tq_avg);
320 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_ADD,
323 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
324 "Changing route to gateway %pM (bandwidth: %u.%u/%u.%u MBit, tq: %i)\n",
325 next_gw->orig_node->orig,
326 next_gw->bandwidth_down / 10,
327 next_gw->bandwidth_down % 10,
328 next_gw->bandwidth_up / 10,
329 next_gw->bandwidth_up % 10,
330 router_ifinfo->bat_iv.tq_avg);
331 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_CHANGE,
335 batadv_gw_select(bat_priv, next_gw);
339 batadv_gw_node_free_ref(curr_gw);
341 batadv_gw_node_free_ref(next_gw);
343 batadv_neigh_node_free_ref(router);
345 batadv_neigh_ifinfo_free_ref(router_ifinfo);
348 void batadv_gw_check_election(struct batadv_priv *bat_priv,
349 struct batadv_orig_node *orig_node)
351 struct batadv_neigh_ifinfo *router_orig_tq = NULL;
352 struct batadv_neigh_ifinfo *router_gw_tq = NULL;
353 struct batadv_orig_node *curr_gw_orig;
354 struct batadv_neigh_node *router_gw = NULL, *router_orig = NULL;
355 uint8_t gw_tq_avg, orig_tq_avg;
357 curr_gw_orig = batadv_gw_get_selected_orig(bat_priv);
361 router_gw = batadv_orig_router_get(curr_gw_orig, BATADV_IF_DEFAULT);
365 router_gw_tq = batadv_neigh_ifinfo_get(router_gw,
370 /* this node already is the gateway */
371 if (curr_gw_orig == orig_node)
374 router_orig = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
378 router_orig_tq = batadv_neigh_ifinfo_get(router_orig,
383 gw_tq_avg = router_gw_tq->bat_iv.tq_avg;
384 orig_tq_avg = router_orig_tq->bat_iv.tq_avg;
386 /* the TQ value has to be better */
387 if (orig_tq_avg < gw_tq_avg)
390 /* if the routing class is greater than 3 the value tells us how much
391 * greater the TQ value of the new gateway must be
393 if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
394 (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
397 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
398 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
399 gw_tq_avg, orig_tq_avg);
402 batadv_gw_reselect(bat_priv);
405 batadv_orig_node_free_ref(curr_gw_orig);
407 batadv_neigh_node_free_ref(router_gw);
409 batadv_neigh_node_free_ref(router_orig);
411 batadv_neigh_ifinfo_free_ref(router_gw_tq);
413 batadv_neigh_ifinfo_free_ref(router_orig_tq);
417 * batadv_gw_node_add - add gateway node to list of available gateways
418 * @bat_priv: the bat priv with all the soft interface information
419 * @orig_node: originator announcing gateway capabilities
420 * @gateway: announced bandwidth information
422 static void batadv_gw_node_add(struct batadv_priv *bat_priv,
423 struct batadv_orig_node *orig_node,
424 struct batadv_tvlv_gateway_data *gateway)
426 struct batadv_gw_node *gw_node;
428 if (gateway->bandwidth_down == 0)
431 if (!atomic_inc_not_zero(&orig_node->refcount))
434 gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
436 batadv_orig_node_free_ref(orig_node);
440 INIT_HLIST_NODE(&gw_node->list);
441 gw_node->orig_node = orig_node;
442 atomic_set(&gw_node->refcount, 1);
444 spin_lock_bh(&bat_priv->gw.list_lock);
445 hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.list);
446 spin_unlock_bh(&bat_priv->gw.list_lock);
448 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
449 "Found new gateway %pM -> gw bandwidth: %u.%u/%u.%u MBit\n",
451 ntohl(gateway->bandwidth_down) / 10,
452 ntohl(gateway->bandwidth_down) % 10,
453 ntohl(gateway->bandwidth_up) / 10,
454 ntohl(gateway->bandwidth_up) % 10);
458 * batadv_gw_node_get - retrieve gateway node from list of available gateways
459 * @bat_priv: the bat priv with all the soft interface information
460 * @orig_node: originator announcing gateway capabilities
462 * Returns gateway node if found or NULL otherwise.
464 static struct batadv_gw_node *
465 batadv_gw_node_get(struct batadv_priv *bat_priv,
466 struct batadv_orig_node *orig_node)
468 struct batadv_gw_node *gw_node_tmp, *gw_node = NULL;
471 hlist_for_each_entry_rcu(gw_node_tmp, &bat_priv->gw.list, list) {
472 if (gw_node_tmp->orig_node != orig_node)
475 if (gw_node_tmp->deleted)
478 if (!atomic_inc_not_zero(&gw_node_tmp->refcount))
481 gw_node = gw_node_tmp;
490 * batadv_gw_node_update - update list of available gateways with changed
491 * bandwidth information
492 * @bat_priv: the bat priv with all the soft interface information
493 * @orig_node: originator announcing gateway capabilities
494 * @gateway: announced bandwidth information
496 void batadv_gw_node_update(struct batadv_priv *bat_priv,
497 struct batadv_orig_node *orig_node,
498 struct batadv_tvlv_gateway_data *gateway)
500 struct batadv_gw_node *gw_node, *curr_gw = NULL;
502 gw_node = batadv_gw_node_get(bat_priv, orig_node);
504 batadv_gw_node_add(bat_priv, orig_node, gateway);
508 if ((gw_node->bandwidth_down == ntohl(gateway->bandwidth_down)) &&
509 (gw_node->bandwidth_up == ntohl(gateway->bandwidth_up)))
512 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
513 "Gateway bandwidth of originator %pM changed from %u.%u/%u.%u MBit to %u.%u/%u.%u MBit\n",
515 gw_node->bandwidth_down / 10,
516 gw_node->bandwidth_down % 10,
517 gw_node->bandwidth_up / 10,
518 gw_node->bandwidth_up % 10,
519 ntohl(gateway->bandwidth_down) / 10,
520 ntohl(gateway->bandwidth_down) % 10,
521 ntohl(gateway->bandwidth_up) / 10,
522 ntohl(gateway->bandwidth_up) % 10);
524 gw_node->bandwidth_down = ntohl(gateway->bandwidth_down);
525 gw_node->bandwidth_up = ntohl(gateway->bandwidth_up);
527 gw_node->deleted = 0;
528 if (ntohl(gateway->bandwidth_down) == 0) {
529 gw_node->deleted = jiffies;
530 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
531 "Gateway %pM removed from gateway list\n",
534 /* Note: We don't need a NULL check here, since curr_gw never
537 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
538 if (gw_node == curr_gw)
539 batadv_gw_reselect(bat_priv);
544 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_purge(struct batadv_priv *bat_priv)
562 struct batadv_gw_node *gw_node, *curr_gw;
563 struct hlist_node *node_tmp;
564 unsigned long timeout = msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT);
567 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
569 spin_lock_bh(&bat_priv->gw.list_lock);
571 hlist_for_each_entry_safe(gw_node, node_tmp,
572 &bat_priv->gw.list, list) {
573 if (((!gw_node->deleted) ||
574 (time_before(jiffies, gw_node->deleted + timeout))) &&
575 atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE)
578 if (curr_gw == gw_node)
581 hlist_del_rcu(&gw_node->list);
582 batadv_gw_node_free_ref(gw_node);
585 spin_unlock_bh(&bat_priv->gw.list_lock);
587 /* gw_reselect() needs to acquire the gw_list_lock */
589 batadv_gw_reselect(bat_priv);
592 batadv_gw_node_free_ref(curr_gw);
595 /* fails if orig_node has no router */
596 static int batadv_write_buffer_text(struct batadv_priv *bat_priv,
597 struct seq_file *seq,
598 const struct batadv_gw_node *gw_node)
600 struct batadv_gw_node *curr_gw;
601 struct batadv_neigh_node *router;
602 struct batadv_neigh_ifinfo *router_ifinfo = NULL;
605 router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
609 router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
613 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
615 seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %u.%u/%u.%u MBit\n",
616 (curr_gw == gw_node ? "=>" : " "),
617 gw_node->orig_node->orig,
618 router_ifinfo->bat_iv.tq_avg, router->addr,
619 router->if_incoming->net_dev->name,
620 gw_node->bandwidth_down / 10,
621 gw_node->bandwidth_down % 10,
622 gw_node->bandwidth_up / 10,
623 gw_node->bandwidth_up % 10);
624 ret = seq_has_overflowed(seq) ? -1 : 0;
627 batadv_gw_node_free_ref(curr_gw);
630 batadv_neigh_ifinfo_free_ref(router_ifinfo);
632 batadv_neigh_node_free_ref(router);
636 int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset)
638 struct net_device *net_dev = (struct net_device *)seq->private;
639 struct batadv_priv *bat_priv = netdev_priv(net_dev);
640 struct batadv_hard_iface *primary_if;
641 struct batadv_gw_node *gw_node;
644 primary_if = batadv_seq_print_text_primary_if_get(seq);
649 " %-12s (%s/%i) %17s [%10s]: advertised uplink bandwidth ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
650 "Gateway", "#", BATADV_TQ_MAX_VALUE, "Nexthop", "outgoingIF",
651 BATADV_SOURCE_VERSION, primary_if->net_dev->name,
652 primary_if->net_dev->dev_addr, net_dev->name);
655 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
656 if (gw_node->deleted)
659 /* fails if orig_node has no router */
660 if (batadv_write_buffer_text(bat_priv, seq, gw_node) < 0)
668 seq_puts(seq, "No gateways in range ...\n");
672 batadv_hardif_free_ref(primary_if);
677 * batadv_gw_dhcp_recipient_get - check if a packet is a DHCP message
678 * @skb: the packet to check
679 * @header_len: a pointer to the batman-adv header size
680 * @chaddr: buffer where the client address will be stored. Valid
681 * only if the function returns BATADV_DHCP_TO_CLIENT
684 * - BATADV_DHCP_NO if the packet is not a dhcp message or if there was an error
686 * - BATADV_DHCP_TO_SERVER if this is a message going to the DHCP server
687 * - BATADV_DHCP_TO_CLIENT if this is a message going to a DHCP client
689 * This function may re-allocate the data buffer of the skb passed as argument.
691 enum batadv_dhcp_recipient
692 batadv_gw_dhcp_recipient_get(struct sk_buff *skb, unsigned int *header_len,
695 enum batadv_dhcp_recipient ret = BATADV_DHCP_NO;
696 struct ethhdr *ethhdr;
698 struct ipv6hdr *ipv6hdr;
699 struct udphdr *udphdr;
700 struct vlan_ethhdr *vhdr;
705 /* check for ethernet header */
706 if (!pskb_may_pull(skb, *header_len + ETH_HLEN))
707 return BATADV_DHCP_NO;
709 ethhdr = eth_hdr(skb);
710 proto = ethhdr->h_proto;
711 *header_len += ETH_HLEN;
713 /* check for initial vlan header */
714 if (proto == htons(ETH_P_8021Q)) {
715 if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))
716 return BATADV_DHCP_NO;
718 vhdr = vlan_eth_hdr(skb);
719 proto = vhdr->h_vlan_encapsulated_proto;
720 *header_len += VLAN_HLEN;
723 /* check for ip header */
725 case htons(ETH_P_IP):
726 if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr)))
727 return BATADV_DHCP_NO;
729 iphdr = (struct iphdr *)(skb->data + *header_len);
730 *header_len += iphdr->ihl * 4;
732 /* check for udp header */
733 if (iphdr->protocol != IPPROTO_UDP)
734 return BATADV_DHCP_NO;
737 case htons(ETH_P_IPV6):
738 if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr)))
739 return BATADV_DHCP_NO;
741 ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len);
742 *header_len += sizeof(*ipv6hdr);
744 /* check for udp header */
745 if (ipv6hdr->nexthdr != IPPROTO_UDP)
746 return BATADV_DHCP_NO;
750 return BATADV_DHCP_NO;
753 if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr)))
754 return BATADV_DHCP_NO;
756 udphdr = (struct udphdr *)(skb->data + *header_len);
757 *header_len += sizeof(*udphdr);
759 /* check for bootp port */
761 case htons(ETH_P_IP):
762 if (udphdr->dest == htons(67))
763 ret = BATADV_DHCP_TO_SERVER;
764 else if (udphdr->source == htons(67))
765 ret = BATADV_DHCP_TO_CLIENT;
767 case htons(ETH_P_IPV6):
768 if (udphdr->dest == htons(547))
769 ret = BATADV_DHCP_TO_SERVER;
770 else if (udphdr->source == htons(547))
771 ret = BATADV_DHCP_TO_CLIENT;
775 chaddr_offset = *header_len + BATADV_DHCP_CHADDR_OFFSET;
776 /* store the client address if the message is going to a client */
777 if (ret == BATADV_DHCP_TO_CLIENT &&
778 pskb_may_pull(skb, chaddr_offset + ETH_ALEN)) {
779 /* check if the DHCP packet carries an Ethernet DHCP */
780 p = skb->data + *header_len + BATADV_DHCP_HTYPE_OFFSET;
781 if (*p != BATADV_DHCP_HTYPE_ETHERNET)
782 return BATADV_DHCP_NO;
784 /* check if the DHCP packet carries a valid Ethernet address */
785 p = skb->data + *header_len + BATADV_DHCP_HLEN_OFFSET;
787 return BATADV_DHCP_NO;
789 ether_addr_copy(chaddr, skb->data + chaddr_offset);
796 * batadv_gw_out_of_range - check if the dhcp request destination is the best gw
797 * @bat_priv: the bat priv with all the soft interface information
798 * @skb: the outgoing packet
800 * Check if the skb is a DHCP request and if it is sent to the current best GW
801 * server. Due to topology changes it may be the case that the GW server
802 * previously selected is not the best one anymore.
804 * Returns true if the packet destination is unicast and it is not the best gw,
807 * This call might reallocate skb data.
808 * Must be invoked only when the DHCP packet is going TO a DHCP SERVER.
810 bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
813 struct batadv_neigh_node *neigh_curr = NULL, *neigh_old = NULL;
814 struct batadv_orig_node *orig_dst_node = NULL;
815 struct batadv_gw_node *gw_node = NULL, *curr_gw = NULL;
816 struct batadv_neigh_ifinfo *curr_ifinfo, *old_ifinfo;
817 struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
818 bool out_of_range = false;
822 vid = batadv_get_vid(skb, 0);
824 orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
825 ethhdr->h_dest, vid);
829 gw_node = batadv_gw_node_get(bat_priv, orig_dst_node);
833 switch (atomic_read(&bat_priv->gw_mode)) {
834 case BATADV_GW_MODE_SERVER:
835 /* If we are a GW then we are our best GW. We can artificially
836 * set the tq towards ourself as the maximum value
838 curr_tq_avg = BATADV_TQ_MAX_VALUE;
840 case BATADV_GW_MODE_CLIENT:
841 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
845 /* packet is going to our gateway */
846 if (curr_gw->orig_node == orig_dst_node)
849 /* If the dhcp packet has been sent to a different gw,
850 * we have to evaluate whether the old gw is still
853 neigh_curr = batadv_find_router(bat_priv, curr_gw->orig_node,
858 curr_ifinfo = batadv_neigh_ifinfo_get(neigh_curr,
863 curr_tq_avg = curr_ifinfo->bat_iv.tq_avg;
864 batadv_neigh_ifinfo_free_ref(curr_ifinfo);
867 case BATADV_GW_MODE_OFF:
872 neigh_old = batadv_find_router(bat_priv, orig_dst_node, NULL);
876 old_ifinfo = batadv_neigh_ifinfo_get(neigh_old, BATADV_IF_DEFAULT);
880 if ((curr_tq_avg - old_ifinfo->bat_iv.tq_avg) > BATADV_GW_THRESHOLD)
882 batadv_neigh_ifinfo_free_ref(old_ifinfo);
886 batadv_orig_node_free_ref(orig_dst_node);
888 batadv_gw_node_free_ref(curr_gw);
890 batadv_gw_node_free_ref(gw_node);
892 batadv_neigh_node_free_ref(neigh_old);
894 batadv_neigh_node_free_ref(neigh_curr);