2 * Copyright (C) 2009-2012 B.A.T.M.A.N. contributors:
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of version 2 of the GNU General Public
8 * License as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
23 #include "bat_sysfs.h"
24 #include "gateway_client.h"
25 #include "gateway_common.h"
26 #include "hard-interface.h"
27 #include "originator.h"
28 #include "translation-table.h"
31 #include <linux/ipv6.h>
32 #include <linux/udp.h>
33 #include <linux/if_vlan.h>
35 /* This is the offset of the options field in a dhcp packet starting at
36 * the beginning of the dhcp header */
37 #define DHCP_OPTIONS_OFFSET 240
38 #define DHCP_REQUEST 3
40 static void gw_node_free_ref(struct gw_node
*gw_node
)
42 if (atomic_dec_and_test(&gw_node
->refcount
))
43 kfree_rcu(gw_node
, rcu
);
46 static struct gw_node
*gw_get_selected_gw_node(struct bat_priv
*bat_priv
)
48 struct gw_node
*gw_node
;
51 gw_node
= rcu_dereference(bat_priv
->curr_gw
);
55 if (!atomic_inc_not_zero(&gw_node
->refcount
))
63 struct orig_node
*gw_get_selected_orig(struct bat_priv
*bat_priv
)
65 struct gw_node
*gw_node
;
66 struct orig_node
*orig_node
= NULL
;
68 gw_node
= gw_get_selected_gw_node(bat_priv
);
73 orig_node
= gw_node
->orig_node
;
77 if (!atomic_inc_not_zero(&orig_node
->refcount
))
84 gw_node_free_ref(gw_node
);
88 static void gw_select(struct bat_priv
*bat_priv
, struct gw_node
*new_gw_node
)
90 struct gw_node
*curr_gw_node
;
92 spin_lock_bh(&bat_priv
->gw_list_lock
);
94 if (new_gw_node
&& !atomic_inc_not_zero(&new_gw_node
->refcount
))
97 curr_gw_node
= rcu_dereference_protected(bat_priv
->curr_gw
, 1);
98 rcu_assign_pointer(bat_priv
->curr_gw
, new_gw_node
);
101 gw_node_free_ref(curr_gw_node
);
103 spin_unlock_bh(&bat_priv
->gw_list_lock
);
106 void gw_deselect(struct bat_priv
*bat_priv
)
108 atomic_set(&bat_priv
->gw_reselect
, 1);
111 static struct gw_node
*gw_get_best_gw_node(struct bat_priv
*bat_priv
)
113 struct neigh_node
*router
;
114 struct hlist_node
*node
;
115 struct gw_node
*gw_node
, *curr_gw
= NULL
;
116 uint32_t max_gw_factor
= 0, tmp_gw_factor
= 0;
121 hlist_for_each_entry_rcu(gw_node
, node
, &bat_priv
->gw_list
, list
) {
122 if (gw_node
->deleted
)
125 router
= orig_node_get_router(gw_node
->orig_node
);
129 if (!atomic_inc_not_zero(&gw_node
->refcount
))
132 switch (atomic_read(&bat_priv
->gw_sel_class
)) {
133 case 1: /* fast connection */
134 gw_bandwidth_to_kbit(gw_node
->orig_node
->gw_flags
,
137 tmp_gw_factor
= (router
->tq_avg
* router
->tq_avg
*
139 (TQ_LOCAL_WINDOW_SIZE
*
140 TQ_LOCAL_WINDOW_SIZE
* 64);
142 if ((tmp_gw_factor
> max_gw_factor
) ||
143 ((tmp_gw_factor
== max_gw_factor
) &&
144 (router
->tq_avg
> max_tq
))) {
146 gw_node_free_ref(curr_gw
);
148 atomic_inc(&curr_gw
->refcount
);
153 * 2: stable connection (use best statistic)
154 * 3: fast-switch (use best statistic but change as
155 * soon as a better gateway appears)
156 * XX: late-switch (use best statistic but change as
157 * soon as a better gateway appears which has
158 * $routing_class more tq points)
160 if (router
->tq_avg
> max_tq
) {
162 gw_node_free_ref(curr_gw
);
164 atomic_inc(&curr_gw
->refcount
);
169 if (router
->tq_avg
> max_tq
)
170 max_tq
= router
->tq_avg
;
172 if (tmp_gw_factor
> max_gw_factor
)
173 max_gw_factor
= tmp_gw_factor
;
175 gw_node_free_ref(gw_node
);
178 neigh_node_free_ref(router
);
185 void gw_election(struct bat_priv
*bat_priv
)
187 struct gw_node
*curr_gw
= NULL
, *next_gw
= NULL
;
188 struct neigh_node
*router
= NULL
;
189 char gw_addr
[18] = { '\0' };
192 * The batman daemon checks here if we already passed a full originator
193 * cycle in order to make sure we don't choose the first gateway we
194 * hear about. This check is based on the daemon's uptime which we
197 if (atomic_read(&bat_priv
->gw_mode
) != GW_MODE_CLIENT
)
200 if (!atomic_dec_not_zero(&bat_priv
->gw_reselect
))
203 curr_gw
= gw_get_selected_gw_node(bat_priv
);
205 next_gw
= gw_get_best_gw_node(bat_priv
);
207 if (curr_gw
== next_gw
)
211 sprintf(gw_addr
, "%pM", next_gw
->orig_node
->orig
);
213 router
= orig_node_get_router(next_gw
->orig_node
);
215 gw_deselect(bat_priv
);
220 if ((curr_gw
) && (!next_gw
)) {
221 bat_dbg(DBG_BATMAN
, bat_priv
,
222 "Removing selected gateway - no gateway in range\n");
223 throw_uevent(bat_priv
, UEV_GW
, UEV_DEL
, NULL
);
224 } else if ((!curr_gw
) && (next_gw
)) {
225 bat_dbg(DBG_BATMAN
, bat_priv
,
226 "Adding route to gateway %pM (gw_flags: %i, tq: %i)\n",
227 next_gw
->orig_node
->orig
, next_gw
->orig_node
->gw_flags
,
229 throw_uevent(bat_priv
, UEV_GW
, UEV_ADD
, gw_addr
);
231 bat_dbg(DBG_BATMAN
, bat_priv
,
232 "Changing route to gateway %pM (gw_flags: %i, tq: %i)\n",
233 next_gw
->orig_node
->orig
, next_gw
->orig_node
->gw_flags
,
235 throw_uevent(bat_priv
, UEV_GW
, UEV_CHANGE
, gw_addr
);
238 gw_select(bat_priv
, next_gw
);
242 gw_node_free_ref(curr_gw
);
244 gw_node_free_ref(next_gw
);
246 neigh_node_free_ref(router
);
249 void gw_check_election(struct bat_priv
*bat_priv
, struct orig_node
*orig_node
)
251 struct orig_node
*curr_gw_orig
;
252 struct neigh_node
*router_gw
= NULL
, *router_orig
= NULL
;
253 uint8_t gw_tq_avg
, orig_tq_avg
;
255 curr_gw_orig
= gw_get_selected_orig(bat_priv
);
259 router_gw
= orig_node_get_router(curr_gw_orig
);
263 /* this node already is the gateway */
264 if (curr_gw_orig
== orig_node
)
267 router_orig
= orig_node_get_router(orig_node
);
271 gw_tq_avg
= router_gw
->tq_avg
;
272 orig_tq_avg
= router_orig
->tq_avg
;
274 /* the TQ value has to be better */
275 if (orig_tq_avg
< gw_tq_avg
)
279 * if the routing class is greater than 3 the value tells us how much
280 * greater the TQ value of the new gateway must be
282 if ((atomic_read(&bat_priv
->gw_sel_class
) > 3) &&
283 (orig_tq_avg
- gw_tq_avg
< atomic_read(&bat_priv
->gw_sel_class
)))
286 bat_dbg(DBG_BATMAN
, bat_priv
,
287 "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
288 gw_tq_avg
, orig_tq_avg
);
291 gw_deselect(bat_priv
);
294 orig_node_free_ref(curr_gw_orig
);
296 neigh_node_free_ref(router_gw
);
298 neigh_node_free_ref(router_orig
);
303 static void gw_node_add(struct bat_priv
*bat_priv
,
304 struct orig_node
*orig_node
, uint8_t new_gwflags
)
306 struct gw_node
*gw_node
;
309 gw_node
= kzalloc(sizeof(*gw_node
), GFP_ATOMIC
);
313 INIT_HLIST_NODE(&gw_node
->list
);
314 gw_node
->orig_node
= orig_node
;
315 atomic_set(&gw_node
->refcount
, 1);
317 spin_lock_bh(&bat_priv
->gw_list_lock
);
318 hlist_add_head_rcu(&gw_node
->list
, &bat_priv
->gw_list
);
319 spin_unlock_bh(&bat_priv
->gw_list_lock
);
321 gw_bandwidth_to_kbit(new_gwflags
, &down
, &up
);
322 bat_dbg(DBG_BATMAN
, bat_priv
,
323 "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
324 orig_node
->orig
, new_gwflags
,
325 (down
> 2048 ? down
/ 1024 : down
),
326 (down
> 2048 ? "MBit" : "KBit"),
327 (up
> 2048 ? up
/ 1024 : up
),
328 (up
> 2048 ? "MBit" : "KBit"));
331 void gw_node_update(struct bat_priv
*bat_priv
,
332 struct orig_node
*orig_node
, uint8_t new_gwflags
)
334 struct hlist_node
*node
;
335 struct gw_node
*gw_node
, *curr_gw
;
338 * Note: We don't need a NULL check here, since curr_gw never gets
339 * dereferenced. If curr_gw is NULL we also should not exit as we may
340 * have this gateway in our list (duplication check!) even though we
341 * have no currently selected gateway.
343 curr_gw
= gw_get_selected_gw_node(bat_priv
);
346 hlist_for_each_entry_rcu(gw_node
, node
, &bat_priv
->gw_list
, list
) {
347 if (gw_node
->orig_node
!= orig_node
)
350 bat_dbg(DBG_BATMAN
, bat_priv
,
351 "Gateway class of originator %pM changed from %i to %i\n",
352 orig_node
->orig
, gw_node
->orig_node
->gw_flags
,
355 gw_node
->deleted
= 0;
357 if (new_gwflags
== NO_FLAGS
) {
358 gw_node
->deleted
= jiffies
;
359 bat_dbg(DBG_BATMAN
, bat_priv
,
360 "Gateway %pM removed from gateway list\n",
363 if (gw_node
== curr_gw
)
370 if (new_gwflags
== NO_FLAGS
)
373 gw_node_add(bat_priv
, orig_node
, new_gwflags
);
377 gw_deselect(bat_priv
);
382 gw_node_free_ref(curr_gw
);
385 void gw_node_delete(struct bat_priv
*bat_priv
, struct orig_node
*orig_node
)
387 gw_node_update(bat_priv
, orig_node
, 0);
390 void gw_node_purge(struct bat_priv
*bat_priv
)
392 struct gw_node
*gw_node
, *curr_gw
;
393 struct hlist_node
*node
, *node_tmp
;
394 unsigned long timeout
= msecs_to_jiffies(2 * PURGE_TIMEOUT
);
397 curr_gw
= gw_get_selected_gw_node(bat_priv
);
399 spin_lock_bh(&bat_priv
->gw_list_lock
);
401 hlist_for_each_entry_safe(gw_node
, node
, node_tmp
,
402 &bat_priv
->gw_list
, list
) {
403 if (((!gw_node
->deleted
) ||
404 (time_before(jiffies
, gw_node
->deleted
+ timeout
))) &&
405 atomic_read(&bat_priv
->mesh_state
) == MESH_ACTIVE
)
408 if (curr_gw
== gw_node
)
411 hlist_del_rcu(&gw_node
->list
);
412 gw_node_free_ref(gw_node
);
415 spin_unlock_bh(&bat_priv
->gw_list_lock
);
417 /* gw_deselect() needs to acquire the gw_list_lock */
419 gw_deselect(bat_priv
);
422 gw_node_free_ref(curr_gw
);
426 * fails if orig_node has no router
428 static int _write_buffer_text(struct bat_priv
*bat_priv
, struct seq_file
*seq
,
429 const struct gw_node
*gw_node
)
431 struct gw_node
*curr_gw
;
432 struct neigh_node
*router
;
433 int down
, up
, ret
= -1;
435 gw_bandwidth_to_kbit(gw_node
->orig_node
->gw_flags
, &down
, &up
);
437 router
= orig_node_get_router(gw_node
->orig_node
);
441 curr_gw
= gw_get_selected_gw_node(bat_priv
);
443 ret
= seq_printf(seq
, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
444 (curr_gw
== gw_node
? "=>" : " "),
445 gw_node
->orig_node
->orig
,
446 router
->tq_avg
, router
->addr
,
447 router
->if_incoming
->net_dev
->name
,
448 gw_node
->orig_node
->gw_flags
,
449 (down
> 2048 ? down
/ 1024 : down
),
450 (down
> 2048 ? "MBit" : "KBit"),
451 (up
> 2048 ? up
/ 1024 : up
),
452 (up
> 2048 ? "MBit" : "KBit"));
454 neigh_node_free_ref(router
);
456 gw_node_free_ref(curr_gw
);
461 int gw_client_seq_print_text(struct seq_file
*seq
, void *offset
)
463 struct net_device
*net_dev
= (struct net_device
*)seq
->private;
464 struct bat_priv
*bat_priv
= netdev_priv(net_dev
);
465 struct hard_iface
*primary_if
;
466 struct gw_node
*gw_node
;
467 struct hlist_node
*node
;
468 int gw_count
= 0, ret
= 0;
470 primary_if
= primary_if_get_selected(bat_priv
);
472 ret
= seq_printf(seq
,
473 "BATMAN mesh %s disabled - please specify interfaces to enable it\n",
478 if (primary_if
->if_status
!= IF_ACTIVE
) {
479 ret
= seq_printf(seq
,
480 "BATMAN mesh %s disabled - primary interface not active\n",
486 " %-12s (%s/%i) %17s [%10s]: gw_class ... [B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
487 "Gateway", "#", TQ_MAX_VALUE
, "Nexthop", "outgoingIF",
488 SOURCE_VERSION
, primary_if
->net_dev
->name
,
489 primary_if
->net_dev
->dev_addr
, net_dev
->name
);
492 hlist_for_each_entry_rcu(gw_node
, node
, &bat_priv
->gw_list
, list
) {
493 if (gw_node
->deleted
)
496 /* fails if orig_node has no router */
497 if (_write_buffer_text(bat_priv
, seq
, gw_node
) < 0)
505 seq_printf(seq
, "No gateways in range ...\n");
509 hardif_free_ref(primary_if
);
513 static bool is_type_dhcprequest(struct sk_buff
*skb
, int header_len
)
519 if (skb_linearize(skb
) < 0)
522 pkt_len
= skb_headlen(skb
);
524 if (pkt_len
< header_len
+ DHCP_OPTIONS_OFFSET
+ 1)
527 p
= skb
->data
+ header_len
+ DHCP_OPTIONS_OFFSET
;
528 pkt_len
-= header_len
+ DHCP_OPTIONS_OFFSET
+ 1;
530 /* Access the dhcp option lists. Each entry is made up by:
531 * - octet 1: option type
532 * - octet 2: option data len (only if type != 255 and 0)
533 * - octet 3: option data */
534 while (*p
!= 255 && !ret
) {
535 /* p now points to the first octet: option type */
537 /* type 53 is the message type option.
538 * Jump the len octet and go to the data octet */
543 /* check if the message type is what we need */
544 if (*p
== 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 */
571 bool 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 gw_out_of_range(struct bat_priv
*bat_priv
,
638 struct sk_buff
*skb
, struct ethhdr
*ethhdr
)
640 struct neigh_node
*neigh_curr
= NULL
, *neigh_old
= NULL
;
641 struct orig_node
*orig_dst_node
= NULL
;
642 struct gw_node
*curr_gw
= NULL
;
643 bool ret
, out_of_range
= false;
644 unsigned int header_len
= 0;
647 ret
= gw_is_dhcp_target(skb
, &header_len
);
651 orig_dst_node
= transtable_search(bat_priv
, ethhdr
->h_source
,
656 if (!orig_dst_node
->gw_flags
)
659 ret
= is_type_dhcprequest(skb
, header_len
);
663 switch (atomic_read(&bat_priv
->gw_mode
)) {
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 */
667 curr_tq_avg
= TQ_MAX_VALUE
;
670 curr_gw
= gw_get_selected_gw_node(bat_priv
);
674 /* packet is going to our gateway */
675 if (curr_gw
->orig_node
== orig_dst_node
)
678 /* If the dhcp packet has been sent to a different gw,
679 * we have to evaluate whether the old gw is still
681 neigh_curr
= find_router(bat_priv
, curr_gw
->orig_node
, NULL
);
685 curr_tq_avg
= neigh_curr
->tq_avg
;
692 neigh_old
= find_router(bat_priv
, orig_dst_node
, NULL
);
696 if (curr_tq_avg
- neigh_old
->tq_avg
> GW_THRESHOLD
)
701 orig_node_free_ref(orig_dst_node
);
703 gw_node_free_ref(curr_gw
);
705 neigh_node_free_ref(neigh_old
);
707 neigh_node_free_ref(neigh_curr
);