1 /* Copyright (C) 2009-2012 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 hlist_node *node;
118 struct batadv_gw_node *gw_node, *curr_gw = NULL;
119 uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
124 struct batadv_orig_node *orig_node;
126 gw_divisor = BATADV_TQ_LOCAL_WINDOW_SIZE * BATADV_TQ_LOCAL_WINDOW_SIZE;
130 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw.list, list) {
131 if (gw_node->deleted)
134 orig_node = gw_node->orig_node;
135 router = batadv_orig_node_get_router(orig_node);
139 if (!atomic_inc_not_zero(&gw_node->refcount))
142 tq_avg = router->tq_avg;
144 switch (atomic_read(&bat_priv->gw_sel_class)) {
145 case 1: /* fast connection */
146 batadv_gw_bandwidth_to_kbit(orig_node->gw_flags,
149 tmp_gw_factor = tq_avg * tq_avg * down * 100 * 100;
150 tmp_gw_factor /= gw_divisor;
152 if ((tmp_gw_factor > max_gw_factor) ||
153 ((tmp_gw_factor == max_gw_factor) &&
154 (tq_avg > max_tq))) {
156 batadv_gw_node_free_ref(curr_gw);
158 atomic_inc(&curr_gw->refcount);
162 default: /* 2: stable connection (use best statistic)
163 * 3: fast-switch (use best statistic but change as
164 * soon as a better gateway appears)
165 * XX: late-switch (use best statistic but change as
166 * soon as a better gateway appears which has
167 * $routing_class more tq points)
169 if (tq_avg > max_tq) {
171 batadv_gw_node_free_ref(curr_gw);
173 atomic_inc(&curr_gw->refcount);
181 if (tmp_gw_factor > max_gw_factor)
182 max_gw_factor = tmp_gw_factor;
184 batadv_gw_node_free_ref(gw_node);
187 batadv_neigh_node_free_ref(router);
194 void batadv_gw_election(struct batadv_priv *bat_priv)
196 struct batadv_gw_node *curr_gw = NULL, *next_gw = NULL;
197 struct batadv_neigh_node *router = NULL;
198 char gw_addr[18] = { '\0' };
200 /* The batman daemon checks here if we already passed a full originator
201 * cycle in order to make sure we don't choose the first gateway we
202 * hear about. This check is based on the daemon's uptime which we
205 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
208 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
210 if (!batadv_atomic_dec_not_zero(&bat_priv->gw.reselect) && curr_gw)
213 next_gw = batadv_gw_get_best_gw_node(bat_priv);
215 if (curr_gw == next_gw)
219 sprintf(gw_addr, "%pM", next_gw->orig_node->orig);
221 router = batadv_orig_node_get_router(next_gw->orig_node);
223 batadv_gw_deselect(bat_priv);
228 if ((curr_gw) && (!next_gw)) {
229 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
230 "Removing selected gateway - no gateway in range\n");
231 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL,
233 } else if ((!curr_gw) && (next_gw)) {
234 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
235 "Adding route to gateway %pM (gw_flags: %i, tq: %i)\n",
236 next_gw->orig_node->orig,
237 next_gw->orig_node->gw_flags, router->tq_avg);
238 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_ADD,
241 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
242 "Changing route to gateway %pM (gw_flags: %i, tq: %i)\n",
243 next_gw->orig_node->orig,
244 next_gw->orig_node->gw_flags, router->tq_avg);
245 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_CHANGE,
249 batadv_gw_select(bat_priv, next_gw);
253 batadv_gw_node_free_ref(curr_gw);
255 batadv_gw_node_free_ref(next_gw);
257 batadv_neigh_node_free_ref(router);
260 void batadv_gw_check_election(struct batadv_priv *bat_priv,
261 struct batadv_orig_node *orig_node)
263 struct batadv_orig_node *curr_gw_orig;
264 struct batadv_neigh_node *router_gw = NULL, *router_orig = NULL;
265 uint8_t gw_tq_avg, orig_tq_avg;
267 curr_gw_orig = batadv_gw_get_selected_orig(bat_priv);
271 router_gw = batadv_orig_node_get_router(curr_gw_orig);
275 /* this node already is the gateway */
276 if (curr_gw_orig == orig_node)
279 router_orig = batadv_orig_node_get_router(orig_node);
283 gw_tq_avg = router_gw->tq_avg;
284 orig_tq_avg = router_orig->tq_avg;
286 /* the TQ value has to be better */
287 if (orig_tq_avg < gw_tq_avg)
290 /* if the routing class is greater than 3 the value tells us how much
291 * greater the TQ value of the new gateway must be
293 if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
294 (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
297 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
298 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
299 gw_tq_avg, orig_tq_avg);
302 batadv_gw_deselect(bat_priv);
305 batadv_orig_node_free_ref(curr_gw_orig);
307 batadv_neigh_node_free_ref(router_gw);
309 batadv_neigh_node_free_ref(router_orig);
314 static void batadv_gw_node_add(struct batadv_priv *bat_priv,
315 struct batadv_orig_node *orig_node,
318 struct batadv_gw_node *gw_node;
321 gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
325 INIT_HLIST_NODE(&gw_node->list);
326 gw_node->orig_node = orig_node;
327 atomic_set(&gw_node->refcount, 1);
329 spin_lock_bh(&bat_priv->gw.list_lock);
330 hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.list);
331 spin_unlock_bh(&bat_priv->gw.list_lock);
333 batadv_gw_bandwidth_to_kbit(new_gwflags, &down, &up);
334 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
335 "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
336 orig_node->orig, new_gwflags,
337 (down > 2048 ? down / 1024 : down),
338 (down > 2048 ? "MBit" : "KBit"),
339 (up > 2048 ? up / 1024 : up),
340 (up > 2048 ? "MBit" : "KBit"));
343 void batadv_gw_node_update(struct batadv_priv *bat_priv,
344 struct batadv_orig_node *orig_node,
347 struct hlist_node *node;
348 struct batadv_gw_node *gw_node, *curr_gw;
350 /* Note: We don't need a NULL check here, since curr_gw never gets
351 * dereferenced. If curr_gw is NULL we also should not exit as we may
352 * have this gateway in our list (duplication check!) even though we
353 * have no currently selected gateway.
355 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
358 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw.list, list) {
359 if (gw_node->orig_node != orig_node)
362 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
363 "Gateway class of originator %pM changed from %i to %i\n",
364 orig_node->orig, gw_node->orig_node->gw_flags,
367 gw_node->deleted = 0;
369 if (new_gwflags == BATADV_NO_FLAGS) {
370 gw_node->deleted = jiffies;
371 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
372 "Gateway %pM removed from gateway list\n",
375 if (gw_node == curr_gw)
382 if (new_gwflags == BATADV_NO_FLAGS)
385 batadv_gw_node_add(bat_priv, orig_node, new_gwflags);
389 batadv_gw_deselect(bat_priv);
394 batadv_gw_node_free_ref(curr_gw);
397 void batadv_gw_node_delete(struct batadv_priv *bat_priv,
398 struct batadv_orig_node *orig_node)
400 batadv_gw_node_update(bat_priv, orig_node, 0);
403 void batadv_gw_node_purge(struct batadv_priv *bat_priv)
405 struct batadv_gw_node *gw_node, *curr_gw;
406 struct hlist_node *node, *node_tmp;
407 unsigned long timeout = msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT);
410 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
412 spin_lock_bh(&bat_priv->gw.list_lock);
414 hlist_for_each_entry_safe(gw_node, node, node_tmp,
415 &bat_priv->gw.list, list) {
416 if (((!gw_node->deleted) ||
417 (time_before(jiffies, gw_node->deleted + timeout))) &&
418 atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE)
421 if (curr_gw == gw_node)
424 hlist_del_rcu(&gw_node->list);
425 batadv_gw_node_free_ref(gw_node);
428 spin_unlock_bh(&bat_priv->gw.list_lock);
430 /* gw_deselect() needs to acquire the gw_list_lock */
432 batadv_gw_deselect(bat_priv);
435 batadv_gw_node_free_ref(curr_gw);
438 /* fails if orig_node has no router */
439 static int batadv_write_buffer_text(struct batadv_priv *bat_priv,
440 struct seq_file *seq,
441 const struct batadv_gw_node *gw_node)
443 struct batadv_gw_node *curr_gw;
444 struct batadv_neigh_node *router;
445 int down, up, ret = -1;
447 batadv_gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
449 router = batadv_orig_node_get_router(gw_node->orig_node);
453 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
455 ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
456 (curr_gw == gw_node ? "=>" : " "),
457 gw_node->orig_node->orig,
458 router->tq_avg, router->addr,
459 router->if_incoming->net_dev->name,
460 gw_node->orig_node->gw_flags,
461 (down > 2048 ? down / 1024 : down),
462 (down > 2048 ? "MBit" : "KBit"),
463 (up > 2048 ? up / 1024 : up),
464 (up > 2048 ? "MBit" : "KBit"));
466 batadv_neigh_node_free_ref(router);
468 batadv_gw_node_free_ref(curr_gw);
473 int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset)
475 struct net_device *net_dev = (struct net_device *)seq->private;
476 struct batadv_priv *bat_priv = netdev_priv(net_dev);
477 struct batadv_hard_iface *primary_if;
478 struct batadv_gw_node *gw_node;
479 struct hlist_node *node;
482 primary_if = batadv_seq_print_text_primary_if_get(seq);
487 " %-12s (%s/%i) %17s [%10s]: gw_class ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
488 "Gateway", "#", BATADV_TQ_MAX_VALUE, "Nexthop", "outgoingIF",
489 BATADV_SOURCE_VERSION, primary_if->net_dev->name,
490 primary_if->net_dev->dev_addr, net_dev->name);
493 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw.list, list) {
494 if (gw_node->deleted)
497 /* fails if orig_node has no router */
498 if (batadv_write_buffer_text(bat_priv, seq, gw_node) < 0)
506 seq_printf(seq, "No gateways in range ...\n");
510 batadv_hardif_free_ref(primary_if);
514 static bool batadv_is_type_dhcprequest(struct sk_buff *skb, int header_len)
520 if (skb_linearize(skb) < 0)
523 pkt_len = skb_headlen(skb);
525 if (pkt_len < header_len + BATADV_DHCP_OPTIONS_OFFSET + 1)
528 p = skb->data + header_len + BATADV_DHCP_OPTIONS_OFFSET;
529 pkt_len -= header_len + BATADV_DHCP_OPTIONS_OFFSET + 1;
531 /* Access the dhcp option lists. Each entry is made up by:
532 * - octet 1: option type
533 * - octet 2: option data len (only if type != 255 and 0)
534 * - octet 3: option data
536 while (*p != 255 && !ret) {
537 /* p now points to the first octet: option type */
539 /* type 53 is the message type option.
540 * Jump the len octet and go to the data octet
546 /* check if the message type is what we need */
547 if (*p == BATADV_DHCP_REQUEST)
550 } else if (*p == 0) {
551 /* option type 0 (padding), just go forward */
557 /* This is any other option. So we get the length... */
563 /* ...and then we jump over the data */
564 if (pkt_len < 1 + (*p))
574 bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len)
576 struct ethhdr *ethhdr;
578 struct ipv6hdr *ipv6hdr;
579 struct udphdr *udphdr;
581 /* check for ethernet header */
582 if (!pskb_may_pull(skb, *header_len + ETH_HLEN))
584 ethhdr = (struct ethhdr *)skb->data;
585 *header_len += ETH_HLEN;
587 /* check for initial vlan header */
588 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
589 if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))
591 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
592 *header_len += VLAN_HLEN;
595 /* check for ip header */
596 switch (ntohs(ethhdr->h_proto)) {
598 if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr)))
600 iphdr = (struct iphdr *)(skb->data + *header_len);
601 *header_len += iphdr->ihl * 4;
603 /* check for udp header */
604 if (iphdr->protocol != IPPROTO_UDP)
609 if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr)))
611 ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len);
612 *header_len += sizeof(*ipv6hdr);
614 /* check for udp header */
615 if (ipv6hdr->nexthdr != IPPROTO_UDP)
623 if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr)))
625 udphdr = (struct udphdr *)(skb->data + *header_len);
626 *header_len += sizeof(*udphdr);
628 /* check for bootp port */
629 if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
630 (ntohs(udphdr->dest) != 67))
633 if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
634 (ntohs(udphdr->dest) != 547))
640 bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
641 struct sk_buff *skb, struct ethhdr *ethhdr)
643 struct batadv_neigh_node *neigh_curr = NULL, *neigh_old = NULL;
644 struct batadv_orig_node *orig_dst_node = NULL;
645 struct batadv_gw_node *curr_gw = NULL;
646 bool ret, out_of_range = false;
647 unsigned int header_len = 0;
650 ret = batadv_gw_is_dhcp_target(skb, &header_len);
654 orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
659 if (!orig_dst_node->gw_flags)
662 ret = batadv_is_type_dhcprequest(skb, header_len);
666 switch (atomic_read(&bat_priv->gw_mode)) {
667 case BATADV_GW_MODE_SERVER:
668 /* If we are a GW then we are our best GW. We can artificially
669 * set the tq towards ourself as the maximum value
671 curr_tq_avg = BATADV_TQ_MAX_VALUE;
673 case BATADV_GW_MODE_CLIENT:
674 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
678 /* packet is going to our gateway */
679 if (curr_gw->orig_node == orig_dst_node)
682 /* If the dhcp packet has been sent to a different gw,
683 * we have to evaluate whether the old gw is still
686 neigh_curr = batadv_find_router(bat_priv, curr_gw->orig_node,
691 curr_tq_avg = neigh_curr->tq_avg;
693 case BATADV_GW_MODE_OFF:
698 neigh_old = batadv_find_router(bat_priv, orig_dst_node, NULL);
702 if (curr_tq_avg - neigh_old->tq_avg > BATADV_GW_THRESHOLD)
707 batadv_orig_node_free_ref(orig_dst_node);
709 batadv_gw_node_free_ref(curr_gw);
711 batadv_neigh_node_free_ref(neigh_old);
713 batadv_neigh_node_free_ref(neigh_curr);