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->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->curr_gw, 1);
100 rcu_assign_pointer(bat_priv->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;
122 struct batadv_orig_node *orig_node;
125 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
126 if (gw_node->deleted)
129 orig_node = gw_node->orig_node;
130 router = batadv_orig_node_get_router(orig_node);
134 if (!atomic_inc_not_zero(&gw_node->refcount))
137 switch (atomic_read(&bat_priv->gw_sel_class)) {
138 case 1: /* fast connection */
139 batadv_gw_bandwidth_to_kbit(orig_node->gw_flags,
142 tmp_gw_factor = (router->tq_avg * router->tq_avg *
144 (BATADV_TQ_LOCAL_WINDOW_SIZE *
145 BATADV_TQ_LOCAL_WINDOW_SIZE * 64);
147 if ((tmp_gw_factor > max_gw_factor) ||
148 ((tmp_gw_factor == max_gw_factor) &&
149 (router->tq_avg > max_tq))) {
151 batadv_gw_node_free_ref(curr_gw);
153 atomic_inc(&curr_gw->refcount);
157 default: /* 2: stable connection (use best statistic)
158 * 3: fast-switch (use best statistic but change as
159 * soon as a better gateway appears)
160 * XX: late-switch (use best statistic but change as
161 * soon as a better gateway appears which has
162 * $routing_class more tq points)
164 if (router->tq_avg > max_tq) {
166 batadv_gw_node_free_ref(curr_gw);
168 atomic_inc(&curr_gw->refcount);
173 if (router->tq_avg > max_tq)
174 max_tq = router->tq_avg;
176 if (tmp_gw_factor > max_gw_factor)
177 max_gw_factor = tmp_gw_factor;
179 batadv_gw_node_free_ref(gw_node);
182 batadv_neigh_node_free_ref(router);
189 void batadv_gw_election(struct batadv_priv *bat_priv)
191 struct batadv_gw_node *curr_gw = NULL, *next_gw = NULL;
192 struct batadv_neigh_node *router = NULL;
193 char gw_addr[18] = { '\0' };
195 /* The batman daemon checks here if we already passed a full originator
196 * cycle in order to make sure we don't choose the first gateway we
197 * hear about. This check is based on the daemon's uptime which we
200 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
203 if (!batadv_atomic_dec_not_zero(&bat_priv->gw_reselect))
206 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
208 next_gw = batadv_gw_get_best_gw_node(bat_priv);
210 if (curr_gw == next_gw)
214 sprintf(gw_addr, "%pM", next_gw->orig_node->orig);
216 router = batadv_orig_node_get_router(next_gw->orig_node);
218 batadv_gw_deselect(bat_priv);
223 if ((curr_gw) && (!next_gw)) {
224 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
225 "Removing selected gateway - no gateway in range\n");
226 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL,
228 } else if ((!curr_gw) && (next_gw)) {
229 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
230 "Adding route to gateway %pM (gw_flags: %i, tq: %i)\n",
231 next_gw->orig_node->orig,
232 next_gw->orig_node->gw_flags, router->tq_avg);
233 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_ADD,
236 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
237 "Changing route to gateway %pM (gw_flags: %i, tq: %i)\n",
238 next_gw->orig_node->orig,
239 next_gw->orig_node->gw_flags, router->tq_avg);
240 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_CHANGE,
244 batadv_gw_select(bat_priv, next_gw);
248 batadv_gw_node_free_ref(curr_gw);
250 batadv_gw_node_free_ref(next_gw);
252 batadv_neigh_node_free_ref(router);
255 void batadv_gw_check_election(struct batadv_priv *bat_priv,
256 struct batadv_orig_node *orig_node)
258 struct batadv_orig_node *curr_gw_orig;
259 struct batadv_neigh_node *router_gw = NULL, *router_orig = NULL;
260 uint8_t gw_tq_avg, orig_tq_avg;
262 curr_gw_orig = batadv_gw_get_selected_orig(bat_priv);
266 router_gw = batadv_orig_node_get_router(curr_gw_orig);
270 /* this node already is the gateway */
271 if (curr_gw_orig == orig_node)
274 router_orig = batadv_orig_node_get_router(orig_node);
278 gw_tq_avg = router_gw->tq_avg;
279 orig_tq_avg = router_orig->tq_avg;
281 /* the TQ value has to be better */
282 if (orig_tq_avg < gw_tq_avg)
285 /* if the routing class is greater than 3 the value tells us how much
286 * greater the TQ value of the new gateway must be
288 if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
289 (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
292 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
293 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
294 gw_tq_avg, orig_tq_avg);
297 batadv_gw_deselect(bat_priv);
300 batadv_orig_node_free_ref(curr_gw_orig);
302 batadv_neigh_node_free_ref(router_gw);
304 batadv_neigh_node_free_ref(router_orig);
309 static void batadv_gw_node_add(struct batadv_priv *bat_priv,
310 struct batadv_orig_node *orig_node,
313 struct batadv_gw_node *gw_node;
316 gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
320 INIT_HLIST_NODE(&gw_node->list);
321 gw_node->orig_node = orig_node;
322 atomic_set(&gw_node->refcount, 1);
324 spin_lock_bh(&bat_priv->gw_list_lock);
325 hlist_add_head_rcu(&gw_node->list, &bat_priv->gw_list);
326 spin_unlock_bh(&bat_priv->gw_list_lock);
328 batadv_gw_bandwidth_to_kbit(new_gwflags, &down, &up);
329 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
330 "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
331 orig_node->orig, new_gwflags,
332 (down > 2048 ? down / 1024 : down),
333 (down > 2048 ? "MBit" : "KBit"),
334 (up > 2048 ? up / 1024 : up),
335 (up > 2048 ? "MBit" : "KBit"));
338 void batadv_gw_node_update(struct batadv_priv *bat_priv,
339 struct batadv_orig_node *orig_node,
342 struct hlist_node *node;
343 struct batadv_gw_node *gw_node, *curr_gw;
345 /* Note: We don't need a NULL check here, since curr_gw never gets
346 * dereferenced. If curr_gw is NULL we also should not exit as we may
347 * have this gateway in our list (duplication check!) even though we
348 * have no currently selected gateway.
350 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
353 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
354 if (gw_node->orig_node != orig_node)
357 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
358 "Gateway class of originator %pM changed from %i to %i\n",
359 orig_node->orig, gw_node->orig_node->gw_flags,
362 gw_node->deleted = 0;
364 if (new_gwflags == BATADV_NO_FLAGS) {
365 gw_node->deleted = jiffies;
366 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
367 "Gateway %pM removed from gateway list\n",
370 if (gw_node == curr_gw)
377 if (new_gwflags == BATADV_NO_FLAGS)
380 batadv_gw_node_add(bat_priv, orig_node, new_gwflags);
384 batadv_gw_deselect(bat_priv);
389 batadv_gw_node_free_ref(curr_gw);
392 void batadv_gw_node_delete(struct batadv_priv *bat_priv,
393 struct batadv_orig_node *orig_node)
395 batadv_gw_node_update(bat_priv, orig_node, 0);
398 void batadv_gw_node_purge(struct batadv_priv *bat_priv)
400 struct batadv_gw_node *gw_node, *curr_gw;
401 struct hlist_node *node, *node_tmp;
402 unsigned long timeout = msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT);
405 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
407 spin_lock_bh(&bat_priv->gw_list_lock);
409 hlist_for_each_entry_safe(gw_node, node, node_tmp,
410 &bat_priv->gw_list, list) {
411 if (((!gw_node->deleted) ||
412 (time_before(jiffies, gw_node->deleted + timeout))) &&
413 atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE)
416 if (curr_gw == gw_node)
419 hlist_del_rcu(&gw_node->list);
420 batadv_gw_node_free_ref(gw_node);
423 spin_unlock_bh(&bat_priv->gw_list_lock);
425 /* gw_deselect() needs to acquire the gw_list_lock */
427 batadv_gw_deselect(bat_priv);
430 batadv_gw_node_free_ref(curr_gw);
433 /* fails if orig_node has no router */
434 static int batadv_write_buffer_text(struct batadv_priv *bat_priv,
435 struct seq_file *seq,
436 const struct batadv_gw_node *gw_node)
438 struct batadv_gw_node *curr_gw;
439 struct batadv_neigh_node *router;
440 int down, up, ret = -1;
442 batadv_gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
444 router = batadv_orig_node_get_router(gw_node->orig_node);
448 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
450 ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
451 (curr_gw == gw_node ? "=>" : " "),
452 gw_node->orig_node->orig,
453 router->tq_avg, router->addr,
454 router->if_incoming->net_dev->name,
455 gw_node->orig_node->gw_flags,
456 (down > 2048 ? down / 1024 : down),
457 (down > 2048 ? "MBit" : "KBit"),
458 (up > 2048 ? up / 1024 : up),
459 (up > 2048 ? "MBit" : "KBit"));
461 batadv_neigh_node_free_ref(router);
463 batadv_gw_node_free_ref(curr_gw);
468 int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset)
470 struct net_device *net_dev = (struct net_device *)seq->private;
471 struct batadv_priv *bat_priv = netdev_priv(net_dev);
472 struct batadv_hard_iface *primary_if;
473 struct batadv_gw_node *gw_node;
474 struct hlist_node *node;
475 int gw_count = 0, ret = 0;
477 primary_if = batadv_primary_if_get_selected(bat_priv);
479 ret = seq_printf(seq,
480 "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
485 if (primary_if->if_status != BATADV_IF_ACTIVE) {
486 ret = seq_printf(seq,
487 "BATMAN mesh %s disabled - primary interface not active\n",
493 " %-12s (%s/%i) %17s [%10s]: gw_class ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
494 "Gateway", "#", BATADV_TQ_MAX_VALUE, "Nexthop", "outgoingIF",
495 BATADV_SOURCE_VERSION, primary_if->net_dev->name,
496 primary_if->net_dev->dev_addr, net_dev->name);
499 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
500 if (gw_node->deleted)
503 /* fails if orig_node has no router */
504 if (batadv_write_buffer_text(bat_priv, seq, gw_node) < 0)
512 seq_printf(seq, "No gateways in range ...\n");
516 batadv_hardif_free_ref(primary_if);
520 static bool batadv_is_type_dhcprequest(struct sk_buff *skb, int header_len)
526 if (skb_linearize(skb) < 0)
529 pkt_len = skb_headlen(skb);
531 if (pkt_len < header_len + BATADV_DHCP_OPTIONS_OFFSET + 1)
534 p = skb->data + header_len + BATADV_DHCP_OPTIONS_OFFSET;
535 pkt_len -= header_len + BATADV_DHCP_OPTIONS_OFFSET + 1;
537 /* Access the dhcp option lists. Each entry is made up by:
538 * - octet 1: option type
539 * - octet 2: option data len (only if type != 255 and 0)
540 * - octet 3: option data
542 while (*p != 255 && !ret) {
543 /* p now points to the first octet: option type */
545 /* type 53 is the message type option.
546 * Jump the len octet and go to the data octet
552 /* check if the message type is what we need */
553 if (*p == BATADV_DHCP_REQUEST)
556 } else if (*p == 0) {
557 /* option type 0 (padding), just go forward */
563 /* This is any other option. So we get the length... */
569 /* ...and then we jump over the data */
570 if (pkt_len < 1 + (*p))
580 bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len)
582 struct ethhdr *ethhdr;
584 struct ipv6hdr *ipv6hdr;
585 struct udphdr *udphdr;
587 /* check for ethernet header */
588 if (!pskb_may_pull(skb, *header_len + ETH_HLEN))
590 ethhdr = (struct ethhdr *)skb->data;
591 *header_len += ETH_HLEN;
593 /* check for initial vlan header */
594 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
595 if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))
597 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
598 *header_len += VLAN_HLEN;
601 /* check for ip header */
602 switch (ntohs(ethhdr->h_proto)) {
604 if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr)))
606 iphdr = (struct iphdr *)(skb->data + *header_len);
607 *header_len += iphdr->ihl * 4;
609 /* check for udp header */
610 if (iphdr->protocol != IPPROTO_UDP)
615 if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr)))
617 ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len);
618 *header_len += sizeof(*ipv6hdr);
620 /* check for udp header */
621 if (ipv6hdr->nexthdr != IPPROTO_UDP)
629 if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr)))
631 udphdr = (struct udphdr *)(skb->data + *header_len);
632 *header_len += sizeof(*udphdr);
634 /* check for bootp port */
635 if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
636 (ntohs(udphdr->dest) != 67))
639 if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
640 (ntohs(udphdr->dest) != 547))
646 bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
647 struct sk_buff *skb, struct ethhdr *ethhdr)
649 struct batadv_neigh_node *neigh_curr = NULL, *neigh_old = NULL;
650 struct batadv_orig_node *orig_dst_node = NULL;
651 struct batadv_gw_node *curr_gw = NULL;
652 bool ret, out_of_range = false;
653 unsigned int header_len = 0;
656 ret = batadv_gw_is_dhcp_target(skb, &header_len);
660 orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
665 if (!orig_dst_node->gw_flags)
668 ret = batadv_is_type_dhcprequest(skb, header_len);
672 switch (atomic_read(&bat_priv->gw_mode)) {
673 case BATADV_GW_MODE_SERVER:
674 /* If we are a GW then we are our best GW. We can artificially
675 * set the tq towards ourself as the maximum value
677 curr_tq_avg = BATADV_TQ_MAX_VALUE;
679 case BATADV_GW_MODE_CLIENT:
680 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
684 /* packet is going to our gateway */
685 if (curr_gw->orig_node == orig_dst_node)
688 /* If the dhcp packet has been sent to a different gw,
689 * we have to evaluate whether the old gw is still
692 neigh_curr = batadv_find_router(bat_priv, curr_gw->orig_node,
697 curr_tq_avg = neigh_curr->tq_avg;
699 case BATADV_GW_MODE_OFF:
704 neigh_old = batadv_find_router(bat_priv, orig_dst_node, NULL);
708 if (curr_tq_avg - neigh_old->tq_avg > BATADV_GW_THRESHOLD)
713 batadv_orig_node_free_ref(orig_dst_node);
715 batadv_gw_node_free_ref(curr_gw);
717 batadv_neigh_node_free_ref(neigh_old);
719 batadv_neigh_node_free_ref(neigh_curr);