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
);