1 /* Copyright (C) 2009-2013 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, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
22 #include "gateway_client.h"
23 #include "gateway_common.h"
24 #include "hard-interface.h"
25 #include "originator.h"
26 #include "translation-table.h"
29 #include <linux/ipv6.h>
30 #include <linux/udp.h>
31 #include <linux/if_vlan.h>
33 /* This is the offset of the options field in a dhcp packet starting at
34 * the beginning of the dhcp header
36 #define BATADV_DHCP_OPTIONS_OFFSET 240
37 #define BATADV_DHCP_REQUEST 3
39 static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node)
41 if (atomic_dec_and_test(&gw_node->refcount))
42 kfree_rcu(gw_node, rcu);
45 static struct batadv_gw_node *
46 batadv_gw_get_selected_gw_node(struct batadv_priv *bat_priv)
48 struct batadv_gw_node *gw_node;
51 gw_node = rcu_dereference(bat_priv->gw.curr_gw);
55 if (!atomic_inc_not_zero(&gw_node->refcount))
63 struct batadv_orig_node *
64 batadv_gw_get_selected_orig(struct batadv_priv *bat_priv)
66 struct batadv_gw_node *gw_node;
67 struct batadv_orig_node *orig_node = NULL;
69 gw_node = batadv_gw_get_selected_gw_node(bat_priv);
74 orig_node = gw_node->orig_node;
78 if (!atomic_inc_not_zero(&orig_node->refcount))
85 batadv_gw_node_free_ref(gw_node);
89 static void batadv_gw_select(struct batadv_priv *bat_priv,
90 struct batadv_gw_node *new_gw_node)
92 struct batadv_gw_node *curr_gw_node;
94 spin_lock_bh(&bat_priv->gw.list_lock);
96 if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
99 curr_gw_node = rcu_dereference_protected(bat_priv->gw.curr_gw, 1);
100 rcu_assign_pointer(bat_priv->gw.curr_gw, new_gw_node);
103 batadv_gw_node_free_ref(curr_gw_node);
105 spin_unlock_bh(&bat_priv->gw.list_lock);
108 void batadv_gw_deselect(struct batadv_priv *bat_priv)
110 atomic_set(&bat_priv->gw.reselect, 1);
113 static struct batadv_gw_node *
114 batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
116 struct batadv_neigh_node *router;
117 struct batadv_gw_node *gw_node, *curr_gw = NULL;
118 uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
123 struct batadv_orig_node *orig_node;
125 gw_divisor = BATADV_TQ_LOCAL_WINDOW_SIZE * BATADV_TQ_LOCAL_WINDOW_SIZE;
129 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
130 if (gw_node->deleted)
133 orig_node = gw_node->orig_node;
134 router = batadv_orig_node_get_router(orig_node);
138 if (!atomic_inc_not_zero(&gw_node->refcount))
141 tq_avg = router->tq_avg;
143 switch (atomic_read(&bat_priv->gw_sel_class)) {
144 case 1: /* fast connection */
145 batadv_gw_bandwidth_to_kbit(orig_node->gw_flags,
148 tmp_gw_factor = tq_avg * tq_avg * down * 100 * 100;
149 tmp_gw_factor /= gw_divisor;
151 if ((tmp_gw_factor > max_gw_factor) ||
152 ((tmp_gw_factor == max_gw_factor) &&
153 (tq_avg > max_tq))) {
155 batadv_gw_node_free_ref(curr_gw);
157 atomic_inc(&curr_gw->refcount);
161 default: /* 2: stable connection (use best statistic)
162 * 3: fast-switch (use best statistic but change as
163 * soon as a better gateway appears)
164 * XX: late-switch (use best statistic but change as
165 * soon as a better gateway appears which has
166 * $routing_class more tq points)
168 if (tq_avg > max_tq) {
170 batadv_gw_node_free_ref(curr_gw);
172 atomic_inc(&curr_gw->refcount);
180 if (tmp_gw_factor > max_gw_factor)
181 max_gw_factor = tmp_gw_factor;
183 batadv_gw_node_free_ref(gw_node);
186 batadv_neigh_node_free_ref(router);
194 * batadv_gw_check_client_stop - check if client mode has been switched off
195 * @bat_priv: the bat priv with all the soft interface information
197 * This function assumes the caller has checked that the gw state *is actually
198 * changing*. This function is not supposed to be called when there is no state
201 void batadv_gw_check_client_stop(struct batadv_priv *bat_priv)
203 struct batadv_gw_node *curr_gw;
205 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
208 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
212 /* if batman-adv is switching the gw client mode off and a gateway was
213 * already selected, send a DEL uevent
215 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL, NULL);
217 batadv_gw_node_free_ref(curr_gw);
220 void batadv_gw_election(struct batadv_priv *bat_priv)
222 struct batadv_gw_node *curr_gw = NULL, *next_gw = NULL;
223 struct batadv_neigh_node *router = NULL;
224 char gw_addr[18] = { '\0' };
226 /* The batman daemon checks here if we already passed a full originator
227 * cycle in order to make sure we don't choose the first gateway we
228 * hear about. This check is based on the daemon's uptime which we
231 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
234 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
236 if (!batadv_atomic_dec_not_zero(&bat_priv->gw.reselect) && curr_gw)
239 next_gw = batadv_gw_get_best_gw_node(bat_priv);
241 if (curr_gw == next_gw)
245 sprintf(gw_addr, "%pM", next_gw->orig_node->orig);
247 router = batadv_orig_node_get_router(next_gw->orig_node);
249 batadv_gw_deselect(bat_priv);
254 if ((curr_gw) && (!next_gw)) {
255 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
256 "Removing selected gateway - no gateway in range\n");
257 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL,
259 } else if ((!curr_gw) && (next_gw)) {
260 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
261 "Adding route to gateway %pM (gw_flags: %i, tq: %i)\n",
262 next_gw->orig_node->orig,
263 next_gw->orig_node->gw_flags, router->tq_avg);
264 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_ADD,
267 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
268 "Changing route to gateway %pM (gw_flags: %i, tq: %i)\n",
269 next_gw->orig_node->orig,
270 next_gw->orig_node->gw_flags, router->tq_avg);
271 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_CHANGE,
275 batadv_gw_select(bat_priv, next_gw);
279 batadv_gw_node_free_ref(curr_gw);
281 batadv_gw_node_free_ref(next_gw);
283 batadv_neigh_node_free_ref(router);
286 void batadv_gw_check_election(struct batadv_priv *bat_priv,
287 struct batadv_orig_node *orig_node)
289 struct batadv_orig_node *curr_gw_orig;
290 struct batadv_neigh_node *router_gw = NULL, *router_orig = NULL;
291 uint8_t gw_tq_avg, orig_tq_avg;
293 curr_gw_orig = batadv_gw_get_selected_orig(bat_priv);
297 router_gw = batadv_orig_node_get_router(curr_gw_orig);
301 /* this node already is the gateway */
302 if (curr_gw_orig == orig_node)
305 router_orig = batadv_orig_node_get_router(orig_node);
309 gw_tq_avg = router_gw->tq_avg;
310 orig_tq_avg = router_orig->tq_avg;
312 /* the TQ value has to be better */
313 if (orig_tq_avg < gw_tq_avg)
316 /* if the routing class is greater than 3 the value tells us how much
317 * greater the TQ value of the new gateway must be
319 if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
320 (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
323 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
324 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
325 gw_tq_avg, orig_tq_avg);
328 batadv_gw_deselect(bat_priv);
331 batadv_orig_node_free_ref(curr_gw_orig);
333 batadv_neigh_node_free_ref(router_gw);
335 batadv_neigh_node_free_ref(router_orig);
340 static void batadv_gw_node_add(struct batadv_priv *bat_priv,
341 struct batadv_orig_node *orig_node,
344 struct batadv_gw_node *gw_node;
347 gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
351 INIT_HLIST_NODE(&gw_node->list);
352 gw_node->orig_node = orig_node;
353 atomic_set(&gw_node->refcount, 1);
355 spin_lock_bh(&bat_priv->gw.list_lock);
356 hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.list);
357 spin_unlock_bh(&bat_priv->gw.list_lock);
359 batadv_gw_bandwidth_to_kbit(new_gwflags, &down, &up);
360 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
361 "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
362 orig_node->orig, new_gwflags,
363 (down > 2048 ? down / 1024 : down),
364 (down > 2048 ? "MBit" : "KBit"),
365 (up > 2048 ? up / 1024 : up),
366 (up > 2048 ? "MBit" : "KBit"));
369 void batadv_gw_node_update(struct batadv_priv *bat_priv,
370 struct batadv_orig_node *orig_node,
373 struct batadv_gw_node *gw_node, *curr_gw;
375 /* Note: We don't need a NULL check here, since curr_gw never gets
376 * dereferenced. If curr_gw is NULL we also should not exit as we may
377 * have this gateway in our list (duplication check!) even though we
378 * have no currently selected gateway.
380 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
383 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
384 if (gw_node->orig_node != orig_node)
387 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
388 "Gateway class of originator %pM changed from %i to %i\n",
389 orig_node->orig, gw_node->orig_node->gw_flags,
392 gw_node->deleted = 0;
394 if (new_gwflags == BATADV_NO_FLAGS) {
395 gw_node->deleted = jiffies;
396 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
397 "Gateway %pM removed from gateway list\n",
400 if (gw_node == curr_gw)
407 if (new_gwflags == BATADV_NO_FLAGS)
410 batadv_gw_node_add(bat_priv, orig_node, new_gwflags);
414 batadv_gw_deselect(bat_priv);
419 batadv_gw_node_free_ref(curr_gw);
422 void batadv_gw_node_delete(struct batadv_priv *bat_priv,
423 struct batadv_orig_node *orig_node)
425 batadv_gw_node_update(bat_priv, orig_node, 0);
428 void batadv_gw_node_purge(struct batadv_priv *bat_priv)
430 struct batadv_gw_node *gw_node, *curr_gw;
431 struct hlist_node *node_tmp;
432 unsigned long timeout = msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT);
435 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
437 spin_lock_bh(&bat_priv->gw.list_lock);
439 hlist_for_each_entry_safe(gw_node, node_tmp,
440 &bat_priv->gw.list, list) {
441 if (((!gw_node->deleted) ||
442 (time_before(jiffies, gw_node->deleted + timeout))) &&
443 atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE)
446 if (curr_gw == gw_node)
449 hlist_del_rcu(&gw_node->list);
450 batadv_gw_node_free_ref(gw_node);
453 spin_unlock_bh(&bat_priv->gw.list_lock);
455 /* gw_deselect() needs to acquire the gw_list_lock */
457 batadv_gw_deselect(bat_priv);
460 batadv_gw_node_free_ref(curr_gw);
463 /* fails if orig_node has no router */
464 static int batadv_write_buffer_text(struct batadv_priv *bat_priv,
465 struct seq_file *seq,
466 const struct batadv_gw_node *gw_node)
468 struct batadv_gw_node *curr_gw;
469 struct batadv_neigh_node *router;
470 int down, up, ret = -1;
472 batadv_gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
474 router = batadv_orig_node_get_router(gw_node->orig_node);
478 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
480 ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
481 (curr_gw == gw_node ? "=>" : " "),
482 gw_node->orig_node->orig,
483 router->tq_avg, router->addr,
484 router->if_incoming->net_dev->name,
485 gw_node->orig_node->gw_flags,
486 (down > 2048 ? down / 1024 : down),
487 (down > 2048 ? "MBit" : "KBit"),
488 (up > 2048 ? up / 1024 : up),
489 (up > 2048 ? "MBit" : "KBit"));
491 batadv_neigh_node_free_ref(router);
493 batadv_gw_node_free_ref(curr_gw);
498 int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset)
500 struct net_device *net_dev = (struct net_device *)seq->private;
501 struct batadv_priv *bat_priv = netdev_priv(net_dev);
502 struct batadv_hard_iface *primary_if;
503 struct batadv_gw_node *gw_node;
506 primary_if = batadv_seq_print_text_primary_if_get(seq);
511 " %-12s (%s/%i) %17s [%10s]: gw_class ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
512 "Gateway", "#", BATADV_TQ_MAX_VALUE, "Nexthop", "outgoingIF",
513 BATADV_SOURCE_VERSION, primary_if->net_dev->name,
514 primary_if->net_dev->dev_addr, net_dev->name);
517 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
518 if (gw_node->deleted)
521 /* fails if orig_node has no router */
522 if (batadv_write_buffer_text(bat_priv, seq, gw_node) < 0)
530 seq_puts(seq, "No gateways in range ...\n");
534 batadv_hardif_free_ref(primary_if);
538 /* this call might reallocate skb data */
539 static bool batadv_is_type_dhcprequest(struct sk_buff *skb, int header_len)
545 if (skb_linearize(skb) < 0)
548 pkt_len = skb_headlen(skb);
550 if (pkt_len < header_len + BATADV_DHCP_OPTIONS_OFFSET + 1)
553 p = skb->data + header_len + BATADV_DHCP_OPTIONS_OFFSET;
554 pkt_len -= header_len + BATADV_DHCP_OPTIONS_OFFSET + 1;
556 /* Access the dhcp option lists. Each entry is made up by:
557 * - octet 1: option type
558 * - octet 2: option data len (only if type != 255 and 0)
559 * - octet 3: option data
561 while (*p != 255 && !ret) {
562 /* p now points to the first octet: option type */
564 /* type 53 is the message type option.
565 * Jump the len octet and go to the data octet
571 /* check if the message type is what we need */
572 if (*p == BATADV_DHCP_REQUEST)
575 } else if (*p == 0) {
576 /* option type 0 (padding), just go forward */
582 /* This is any other option. So we get the length... */
588 /* ...and then we jump over the data */
589 if (pkt_len < 1 + (*p))
599 /* this call might reallocate skb data */
600 bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len)
602 struct ethhdr *ethhdr;
604 struct ipv6hdr *ipv6hdr;
605 struct udphdr *udphdr;
607 /* check for ethernet header */
608 if (!pskb_may_pull(skb, *header_len + ETH_HLEN))
610 ethhdr = (struct ethhdr *)skb->data;
611 *header_len += ETH_HLEN;
613 /* check for initial vlan header */
614 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
615 if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))
617 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
618 *header_len += VLAN_HLEN;
621 /* check for ip header */
622 switch (ntohs(ethhdr->h_proto)) {
624 if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr)))
626 iphdr = (struct iphdr *)(skb->data + *header_len);
627 *header_len += iphdr->ihl * 4;
629 /* check for udp header */
630 if (iphdr->protocol != IPPROTO_UDP)
635 if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr)))
637 ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len);
638 *header_len += sizeof(*ipv6hdr);
640 /* check for udp header */
641 if (ipv6hdr->nexthdr != IPPROTO_UDP)
649 if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr)))
652 /* skb->data might have been reallocated by pskb_may_pull() */
653 ethhdr = (struct ethhdr *)skb->data;
654 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q)
655 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
657 udphdr = (struct udphdr *)(skb->data + *header_len);
658 *header_len += sizeof(*udphdr);
660 /* check for bootp port */
661 if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
662 (ntohs(udphdr->dest) != 67))
665 if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
666 (ntohs(udphdr->dest) != 547))
672 /* this call might reallocate skb data */
673 bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
676 struct batadv_neigh_node *neigh_curr = NULL, *neigh_old = NULL;
677 struct batadv_orig_node *orig_dst_node = NULL;
678 struct batadv_gw_node *curr_gw = NULL;
679 struct ethhdr *ethhdr;
680 bool ret, out_of_range = false;
681 unsigned int header_len = 0;
684 ret = batadv_gw_is_dhcp_target(skb, &header_len);
688 ethhdr = (struct ethhdr *)skb->data;
689 orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
694 if (!orig_dst_node->gw_flags)
697 ret = batadv_is_type_dhcprequest(skb, header_len);
701 switch (atomic_read(&bat_priv->gw_mode)) {
702 case BATADV_GW_MODE_SERVER:
703 /* If we are a GW then we are our best GW. We can artificially
704 * set the tq towards ourself as the maximum value
706 curr_tq_avg = BATADV_TQ_MAX_VALUE;
708 case BATADV_GW_MODE_CLIENT:
709 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
713 /* packet is going to our gateway */
714 if (curr_gw->orig_node == orig_dst_node)
717 /* If the dhcp packet has been sent to a different gw,
718 * we have to evaluate whether the old gw is still
721 neigh_curr = batadv_find_router(bat_priv, curr_gw->orig_node,
726 curr_tq_avg = neigh_curr->tq_avg;
728 case BATADV_GW_MODE_OFF:
733 neigh_old = batadv_find_router(bat_priv, orig_dst_node, NULL);
737 if (curr_tq_avg - neigh_old->tq_avg > BATADV_GW_THRESHOLD)
742 batadv_orig_node_free_ref(orig_dst_node);
744 batadv_gw_node_free_ref(curr_gw);
746 batadv_neigh_node_free_ref(neigh_old);
748 batadv_neigh_node_free_ref(neigh_curr);