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);
193 void batadv_gw_election(struct batadv_priv *bat_priv)
195 struct batadv_gw_node *curr_gw = NULL, *next_gw = NULL;
196 struct batadv_neigh_node *router = NULL;
197 char gw_addr[18] = { '\0' };
199 /* The batman daemon checks here if we already passed a full originator
200 * cycle in order to make sure we don't choose the first gateway we
201 * hear about. This check is based on the daemon's uptime which we
204 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
207 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
209 if (!batadv_atomic_dec_not_zero(&bat_priv->gw.reselect) && curr_gw)
212 next_gw = batadv_gw_get_best_gw_node(bat_priv);
214 if (curr_gw == next_gw)
218 sprintf(gw_addr, "%pM", next_gw->orig_node->orig);
220 router = batadv_orig_node_get_router(next_gw->orig_node);
222 batadv_gw_deselect(bat_priv);
227 if ((curr_gw) && (!next_gw)) {
228 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
229 "Removing selected gateway - no gateway in range\n");
230 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_DEL,
232 } else if ((!curr_gw) && (next_gw)) {
233 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
234 "Adding route to gateway %pM (gw_flags: %i, tq: %i)\n",
235 next_gw->orig_node->orig,
236 next_gw->orig_node->gw_flags, router->tq_avg);
237 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_ADD,
240 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
241 "Changing route to gateway %pM (gw_flags: %i, tq: %i)\n",
242 next_gw->orig_node->orig,
243 next_gw->orig_node->gw_flags, router->tq_avg);
244 batadv_throw_uevent(bat_priv, BATADV_UEV_GW, BATADV_UEV_CHANGE,
248 batadv_gw_select(bat_priv, next_gw);
252 batadv_gw_node_free_ref(curr_gw);
254 batadv_gw_node_free_ref(next_gw);
256 batadv_neigh_node_free_ref(router);
259 void batadv_gw_check_election(struct batadv_priv *bat_priv,
260 struct batadv_orig_node *orig_node)
262 struct batadv_orig_node *curr_gw_orig;
263 struct batadv_neigh_node *router_gw = NULL, *router_orig = NULL;
264 uint8_t gw_tq_avg, orig_tq_avg;
266 curr_gw_orig = batadv_gw_get_selected_orig(bat_priv);
270 router_gw = batadv_orig_node_get_router(curr_gw_orig);
274 /* this node already is the gateway */
275 if (curr_gw_orig == orig_node)
278 router_orig = batadv_orig_node_get_router(orig_node);
282 gw_tq_avg = router_gw->tq_avg;
283 orig_tq_avg = router_orig->tq_avg;
285 /* the TQ value has to be better */
286 if (orig_tq_avg < gw_tq_avg)
289 /* if the routing class is greater than 3 the value tells us how much
290 * greater the TQ value of the new gateway must be
292 if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
293 (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
296 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
297 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
298 gw_tq_avg, orig_tq_avg);
301 batadv_gw_deselect(bat_priv);
304 batadv_orig_node_free_ref(curr_gw_orig);
306 batadv_neigh_node_free_ref(router_gw);
308 batadv_neigh_node_free_ref(router_orig);
313 static void batadv_gw_node_add(struct batadv_priv *bat_priv,
314 struct batadv_orig_node *orig_node,
317 struct batadv_gw_node *gw_node;
320 gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
324 INIT_HLIST_NODE(&gw_node->list);
325 gw_node->orig_node = orig_node;
326 atomic_set(&gw_node->refcount, 1);
328 spin_lock_bh(&bat_priv->gw.list_lock);
329 hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.list);
330 spin_unlock_bh(&bat_priv->gw.list_lock);
332 batadv_gw_bandwidth_to_kbit(new_gwflags, &down, &up);
333 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
334 "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
335 orig_node->orig, new_gwflags,
336 (down > 2048 ? down / 1024 : down),
337 (down > 2048 ? "MBit" : "KBit"),
338 (up > 2048 ? up / 1024 : up),
339 (up > 2048 ? "MBit" : "KBit"));
342 void batadv_gw_node_update(struct batadv_priv *bat_priv,
343 struct batadv_orig_node *orig_node,
346 struct batadv_gw_node *gw_node, *curr_gw;
348 /* Note: We don't need a NULL check here, since curr_gw never gets
349 * dereferenced. If curr_gw is NULL we also should not exit as we may
350 * have this gateway in our list (duplication check!) even though we
351 * have no currently selected gateway.
353 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
356 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
357 if (gw_node->orig_node != orig_node)
360 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
361 "Gateway class of originator %pM changed from %i to %i\n",
362 orig_node->orig, gw_node->orig_node->gw_flags,
365 gw_node->deleted = 0;
367 if (new_gwflags == BATADV_NO_FLAGS) {
368 gw_node->deleted = jiffies;
369 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
370 "Gateway %pM removed from gateway list\n",
373 if (gw_node == curr_gw)
380 if (new_gwflags == BATADV_NO_FLAGS)
383 batadv_gw_node_add(bat_priv, orig_node, new_gwflags);
387 batadv_gw_deselect(bat_priv);
392 batadv_gw_node_free_ref(curr_gw);
395 void batadv_gw_node_delete(struct batadv_priv *bat_priv,
396 struct batadv_orig_node *orig_node)
398 batadv_gw_node_update(bat_priv, orig_node, 0);
401 void batadv_gw_node_purge(struct batadv_priv *bat_priv)
403 struct batadv_gw_node *gw_node, *curr_gw;
404 struct hlist_node *node_tmp;
405 unsigned long timeout = msecs_to_jiffies(2 * BATADV_PURGE_TIMEOUT);
408 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
410 spin_lock_bh(&bat_priv->gw.list_lock);
412 hlist_for_each_entry_safe(gw_node, node_tmp,
413 &bat_priv->gw.list, list) {
414 if (((!gw_node->deleted) ||
415 (time_before(jiffies, gw_node->deleted + timeout))) &&
416 atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE)
419 if (curr_gw == gw_node)
422 hlist_del_rcu(&gw_node->list);
423 batadv_gw_node_free_ref(gw_node);
426 spin_unlock_bh(&bat_priv->gw.list_lock);
428 /* gw_deselect() needs to acquire the gw_list_lock */
430 batadv_gw_deselect(bat_priv);
433 batadv_gw_node_free_ref(curr_gw);
436 /* fails if orig_node has no router */
437 static int batadv_write_buffer_text(struct batadv_priv *bat_priv,
438 struct seq_file *seq,
439 const struct batadv_gw_node *gw_node)
441 struct batadv_gw_node *curr_gw;
442 struct batadv_neigh_node *router;
443 int down, up, ret = -1;
445 batadv_gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
447 router = batadv_orig_node_get_router(gw_node->orig_node);
451 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
453 ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
454 (curr_gw == gw_node ? "=>" : " "),
455 gw_node->orig_node->orig,
456 router->tq_avg, router->addr,
457 router->if_incoming->net_dev->name,
458 gw_node->orig_node->gw_flags,
459 (down > 2048 ? down / 1024 : down),
460 (down > 2048 ? "MBit" : "KBit"),
461 (up > 2048 ? up / 1024 : up),
462 (up > 2048 ? "MBit" : "KBit"));
464 batadv_neigh_node_free_ref(router);
466 batadv_gw_node_free_ref(curr_gw);
471 int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset)
473 struct net_device *net_dev = (struct net_device *)seq->private;
474 struct batadv_priv *bat_priv = netdev_priv(net_dev);
475 struct batadv_hard_iface *primary_if;
476 struct batadv_gw_node *gw_node;
479 primary_if = batadv_seq_print_text_primary_if_get(seq);
484 " %-12s (%s/%i) %17s [%10s]: gw_class ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
485 "Gateway", "#", BATADV_TQ_MAX_VALUE, "Nexthop", "outgoingIF",
486 BATADV_SOURCE_VERSION, primary_if->net_dev->name,
487 primary_if->net_dev->dev_addr, net_dev->name);
490 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
491 if (gw_node->deleted)
494 /* fails if orig_node has no router */
495 if (batadv_write_buffer_text(bat_priv, seq, gw_node) < 0)
503 seq_printf(seq, "No gateways in range ...\n");
507 batadv_hardif_free_ref(primary_if);
511 static bool batadv_is_type_dhcprequest(struct sk_buff *skb, int header_len)
517 if (skb_linearize(skb) < 0)
520 pkt_len = skb_headlen(skb);
522 if (pkt_len < header_len + BATADV_DHCP_OPTIONS_OFFSET + 1)
525 p = skb->data + header_len + BATADV_DHCP_OPTIONS_OFFSET;
526 pkt_len -= header_len + BATADV_DHCP_OPTIONS_OFFSET + 1;
528 /* Access the dhcp option lists. Each entry is made up by:
529 * - octet 1: option type
530 * - octet 2: option data len (only if type != 255 and 0)
531 * - octet 3: option data
533 while (*p != 255 && !ret) {
534 /* p now points to the first octet: option type */
536 /* type 53 is the message type option.
537 * Jump the len octet and go to the data octet
543 /* check if the message type is what we need */
544 if (*p == BATADV_DHCP_REQUEST)
547 } else if (*p == 0) {
548 /* option type 0 (padding), just go forward */
554 /* This is any other option. So we get the length... */
560 /* ...and then we jump over the data */
561 if (pkt_len < 1 + (*p))
571 bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len)
573 struct ethhdr *ethhdr;
575 struct ipv6hdr *ipv6hdr;
576 struct udphdr *udphdr;
578 /* check for ethernet header */
579 if (!pskb_may_pull(skb, *header_len + ETH_HLEN))
581 ethhdr = (struct ethhdr *)skb->data;
582 *header_len += ETH_HLEN;
584 /* check for initial vlan header */
585 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
586 if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))
588 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
589 *header_len += VLAN_HLEN;
592 /* check for ip header */
593 switch (ntohs(ethhdr->h_proto)) {
595 if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr)))
597 iphdr = (struct iphdr *)(skb->data + *header_len);
598 *header_len += iphdr->ihl * 4;
600 /* check for udp header */
601 if (iphdr->protocol != IPPROTO_UDP)
606 if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr)))
608 ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len);
609 *header_len += sizeof(*ipv6hdr);
611 /* check for udp header */
612 if (ipv6hdr->nexthdr != IPPROTO_UDP)
620 if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr)))
622 udphdr = (struct udphdr *)(skb->data + *header_len);
623 *header_len += sizeof(*udphdr);
625 /* check for bootp port */
626 if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
627 (ntohs(udphdr->dest) != 67))
630 if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
631 (ntohs(udphdr->dest) != 547))
637 bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
638 struct sk_buff *skb, struct ethhdr *ethhdr)
640 struct batadv_neigh_node *neigh_curr = NULL, *neigh_old = NULL;
641 struct batadv_orig_node *orig_dst_node = NULL;
642 struct batadv_gw_node *curr_gw = NULL;
643 bool ret, out_of_range = false;
644 unsigned int header_len = 0;
647 ret = batadv_gw_is_dhcp_target(skb, &header_len);
651 orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
656 if (!orig_dst_node->gw_flags)
659 ret = batadv_is_type_dhcprequest(skb, header_len);
663 switch (atomic_read(&bat_priv->gw_mode)) {
664 case BATADV_GW_MODE_SERVER:
665 /* If we are a GW then we are our best GW. We can artificially
666 * set the tq towards ourself as the maximum value
668 curr_tq_avg = BATADV_TQ_MAX_VALUE;
670 case BATADV_GW_MODE_CLIENT:
671 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
675 /* packet is going to our gateway */
676 if (curr_gw->orig_node == orig_dst_node)
679 /* If the dhcp packet has been sent to a different gw,
680 * we have to evaluate whether the old gw is still
683 neigh_curr = batadv_find_router(bat_priv, curr_gw->orig_node,
688 curr_tq_avg = neigh_curr->tq_avg;
690 case BATADV_GW_MODE_OFF:
695 neigh_old = batadv_find_router(bat_priv, orig_dst_node, NULL);
699 if (curr_tq_avg - neigh_old->tq_avg > BATADV_GW_THRESHOLD)
704 batadv_orig_node_free_ref(orig_dst_node);
706 batadv_gw_node_free_ref(curr_gw);
708 batadv_neigh_node_free_ref(neigh_old);
710 batadv_neigh_node_free_ref(neigh_curr);