?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
MIPS: ath79: Fix ar933x watchdog clock
[linux-2.6.git] / net / batman-adv / gateway_client.c
blob7614af31daff3678eb2bb75447810c0e27850f88
1 /* Copyright (C) 2009-2013 B.A.T.M.A.N. contributors:
2 *
3 * Marek Lindner
4 *
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.
8 *
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.
13 *
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
17 * 02110-1301, USA
18 */
19
20 #include "main.h"
21 #include "sysfs.h"
22 #include "gateway_client.h"
23 #include "gateway_common.h"
24 #include "hard-interface.h"
25 #include "originator.h"
26 #include "translation-table.h"
27 #include "routing.h"
28 #include <linux/ip.h>
29 #include <linux/ipv6.h>
30 #include <linux/udp.h>
31 #include <linux/if_vlan.h>
32
33 /* This is the offset of the options field in a dhcp packet starting at
34 * the beginning of the dhcp header
35 */
36 #define BATADV_DHCP_OPTIONS_OFFSET 240
37 #define BATADV_DHCP_REQUEST 3
38
39 static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node)
40 {
41 if (atomic_dec_and_test(&gw_node->refcount))
42 kfree_rcu(gw_node, rcu);
43 }
44
45 static struct batadv_gw_node *
46 batadv_gw_get_selected_gw_node(struct batadv_priv *bat_priv)
47 {
48 struct batadv_gw_node *gw_node;
49
50 rcu_read_lock();
51 gw_node = rcu_dereference(bat_priv->gw.curr_gw);
52 if (!gw_node)
53 goto out;
54
55 if (!atomic_inc_not_zero(&gw_node->refcount))
56 gw_node = NULL;
57
58 out:
59 rcu_read_unlock();
60 return gw_node;
61 }
62
63 struct batadv_orig_node *
64 batadv_gw_get_selected_orig(struct batadv_priv *bat_priv)
65 {
66 struct batadv_gw_node *gw_node;
67 struct batadv_orig_node *orig_node = NULL;
68
69 gw_node = batadv_gw_get_selected_gw_node(bat_priv);
70 if (!gw_node)
71 goto out;
72
73 rcu_read_lock();
74 orig_node = gw_node->orig_node;
75 if (!orig_node)
76 goto unlock;
77
78 if (!atomic_inc_not_zero(&orig_node->refcount))
79 orig_node = NULL;
80
81 unlock:
82 rcu_read_unlock();
83 out:
84 if (gw_node)
85 batadv_gw_node_free_ref(gw_node);
86 return orig_node;
87 }
88
89 static void batadv_gw_select(struct batadv_priv *bat_priv,
90 struct batadv_gw_node *new_gw_node)
91 {
92 struct batadv_gw_node *curr_gw_node;
93
94 spin_lock_bh(&bat_priv->gw.list_lock);
95
96 if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
97 new_gw_node = NULL;
98
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);
101
102 if (curr_gw_node)
103 batadv_gw_node_free_ref(curr_gw_node);
104
105 spin_unlock_bh(&bat_priv->gw.list_lock);
106 }
107
108 void batadv_gw_deselect(struct batadv_priv *bat_priv)
109 {
110 atomic_set(&bat_priv->gw.reselect, 1);
111 }
112
113 static struct batadv_gw_node *
114 batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
115 {
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;
119 uint32_t gw_divisor;
120 uint8_t max_tq = 0;
121 int down, up;
122 uint8_t tq_avg;
123 struct batadv_orig_node *orig_node;
124
125 gw_divisor = BATADV_TQ_LOCAL_WINDOW_SIZE * BATADV_TQ_LOCAL_WINDOW_SIZE;
126 gw_divisor *= 64;
127
128 rcu_read_lock();
129 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
130 if (gw_node->deleted)
131 continue;
132
133 orig_node = gw_node->orig_node;
134 router = batadv_orig_node_get_router(orig_node);
135 if (!router)
136 continue;
137
138 if (!atomic_inc_not_zero(&gw_node->refcount))
139 goto next;
140
141 tq_avg = router->tq_avg;
142
143 switch (atomic_read(&bat_priv->gw_sel_class)) {
144 case 1: /* fast connection */
145 batadv_gw_bandwidth_to_kbit(orig_node->gw_flags,
146 &down, &up);
147
148 tmp_gw_factor = tq_avg * tq_avg * down * 100 * 100;
149 tmp_gw_factor /= gw_divisor;
150
151 if ((tmp_gw_factor > max_gw_factor) ||
152 ((tmp_gw_factor == max_gw_factor) &&
153 (tq_avg > max_tq))) {
154 if (curr_gw)
155 batadv_gw_node_free_ref(curr_gw);
156 curr_gw = gw_node;
157 atomic_inc(&curr_gw->refcount);
158 }
159 break;
160
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)
167 */
168 if (tq_avg > max_tq) {
169 if (curr_gw)
170 batadv_gw_node_free_ref(curr_gw);
171 curr_gw = gw_node;
172 atomic_inc(&curr_gw->refcount);
173 }
174 break;
175 }
176
177 if (tq_avg > max_tq)
178 max_tq = tq_avg;
179
180 if (tmp_gw_factor > max_gw_factor)
181 max_gw_factor = tmp_gw_factor;
182
183 batadv_gw_node_free_ref(gw_node);
184
185 next:
186 batadv_neigh_node_free_ref(router);
187 }
188 rcu_read_unlock();
189
190 return curr_gw;
191 }
192
193 void batadv_gw_election(struct batadv_priv *bat_priv)
194 {
195 struct batadv_gw_node *curr_gw = NULL, *next_gw = NULL;
196 struct batadv_neigh_node *router = NULL;
197 char gw_addr[18] = { '\0' };
198
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
202 * don't have.
203 */
204 if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_CLIENT)
205 goto out;
206
207 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
208
209 if (!batadv_atomic_dec_not_zero(&bat_priv->gw.reselect) && curr_gw)
210 goto out;
211
212 next_gw = batadv_gw_get_best_gw_node(bat_priv);
213
214 if (curr_gw == next_gw)
215 goto out;
216
217 if (next_gw) {
218 sprintf(gw_addr, "%pM", next_gw->orig_node->orig);
219
220 router = batadv_orig_node_get_router(next_gw->orig_node);
221 if (!router) {
222 batadv_gw_deselect(bat_priv);
223 goto out;
224 }
225 }
226
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,
231 NULL);
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,
238 gw_addr);
239 } else {
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,
245 gw_addr);
246 }
247
248 batadv_gw_select(bat_priv, next_gw);
249
250 out:
251 if (curr_gw)
252 batadv_gw_node_free_ref(curr_gw);
253 if (next_gw)
254 batadv_gw_node_free_ref(next_gw);
255 if (router)
256 batadv_neigh_node_free_ref(router);
257 }
258
259 void batadv_gw_check_election(struct batadv_priv *bat_priv,
260 struct batadv_orig_node *orig_node)
261 {
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;
265
266 curr_gw_orig = batadv_gw_get_selected_orig(bat_priv);
267 if (!curr_gw_orig)
268 goto deselect;
269
270 router_gw = batadv_orig_node_get_router(curr_gw_orig);
271 if (!router_gw)
272 goto deselect;
273
274 /* this node already is the gateway */
275 if (curr_gw_orig == orig_node)
276 goto out;
277
278 router_orig = batadv_orig_node_get_router(orig_node);
279 if (!router_orig)
280 goto out;
281
282 gw_tq_avg = router_gw->tq_avg;
283 orig_tq_avg = router_orig->tq_avg;
284
285 /* the TQ value has to be better */
286 if (orig_tq_avg < gw_tq_avg)
287 goto out;
288
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
291 */
292 if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
293 (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
294 goto out;
295
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);
299
300 deselect:
301 batadv_gw_deselect(bat_priv);
302 out:
303 if (curr_gw_orig)
304 batadv_orig_node_free_ref(curr_gw_orig);
305 if (router_gw)
306 batadv_neigh_node_free_ref(router_gw);
307 if (router_orig)
308 batadv_neigh_node_free_ref(router_orig);
309
310 return;
311 }
312
313 static void batadv_gw_node_add(struct batadv_priv *bat_priv,
314 struct batadv_orig_node *orig_node,
315 uint8_t new_gwflags)
316 {
317 struct batadv_gw_node *gw_node;
318 int down, up;
319
320 gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
321 if (!gw_node)
322 return;
323
324 INIT_HLIST_NODE(&gw_node->list);
325 gw_node->orig_node = orig_node;
326 atomic_set(&gw_node->refcount, 1);
327
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);
331
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"));
340 }
341
342 void batadv_gw_node_update(struct batadv_priv *bat_priv,
343 struct batadv_orig_node *orig_node,
344 uint8_t new_gwflags)
345 {
346 struct batadv_gw_node *gw_node, *curr_gw;
347
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.
352 */
353 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
354
355 rcu_read_lock();
356 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
357 if (gw_node->orig_node != orig_node)
358 continue;
359
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,
363 new_gwflags);
364
365 gw_node->deleted = 0;
366
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",
371 orig_node->orig);
372
373 if (gw_node == curr_gw)
374 goto deselect;
375 }
376
377 goto unlock;
378 }
379
380 if (new_gwflags == BATADV_NO_FLAGS)
381 goto unlock;
382
383 batadv_gw_node_add(bat_priv, orig_node, new_gwflags);
384 goto unlock;
385
386 deselect:
387 batadv_gw_deselect(bat_priv);
388 unlock:
389 rcu_read_unlock();
390
391 if (curr_gw)
392 batadv_gw_node_free_ref(curr_gw);
393 }
394
395 void batadv_gw_node_delete(struct batadv_priv *bat_priv,
396 struct batadv_orig_node *orig_node)
397 {
398 batadv_gw_node_update(bat_priv, orig_node, 0);
399 }
400
401 void batadv_gw_node_purge(struct batadv_priv *bat_priv)
402 {
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);
406 int do_deselect = 0;
407
408 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
409
410 spin_lock_bh(&bat_priv->gw.list_lock);
411
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)
417 continue;
418
419 if (curr_gw == gw_node)
420 do_deselect = 1;
421
422 hlist_del_rcu(&gw_node->list);
423 batadv_gw_node_free_ref(gw_node);
424 }
425
426 spin_unlock_bh(&bat_priv->gw.list_lock);
427
428 /* gw_deselect() needs to acquire the gw_list_lock */
429 if (do_deselect)
430 batadv_gw_deselect(bat_priv);
431
432 if (curr_gw)
433 batadv_gw_node_free_ref(curr_gw);
434 }
435
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)
440 {
441 struct batadv_gw_node *curr_gw;
442 struct batadv_neigh_node *router;
443 int down, up, ret = -1;
444
445 batadv_gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
446
447 router = batadv_orig_node_get_router(gw_node->orig_node);
448 if (!router)
449 goto out;
450
451 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
452
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"));
463
464 batadv_neigh_node_free_ref(router);
465 if (curr_gw)
466 batadv_gw_node_free_ref(curr_gw);
467 out:
468 return ret;
469 }
470
471 int batadv_gw_client_seq_print_text(struct seq_file *seq, void *offset)
472 {
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;
477 int gw_count = 0;
478
479 primary_if = batadv_seq_print_text_primary_if_get(seq);
480 if (!primary_if)
481 goto out;
482
483 seq_printf(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);
488
489 rcu_read_lock();
490 hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
491 if (gw_node->deleted)
492 continue;
493
494 /* fails if orig_node has no router */
495 if (batadv_write_buffer_text(bat_priv, seq, gw_node) < 0)
496 continue;
497
498 gw_count++;
499 }
500 rcu_read_unlock();
501
502 if (gw_count == 0)
503 seq_puts(seq, "No gateways in range ...\n");
504
505 out:
506 if (primary_if)
507 batadv_hardif_free_ref(primary_if);
508 return 0;
509 }
510
511 /* this call might reallocate skb data */
512 static bool batadv_is_type_dhcprequest(struct sk_buff *skb, int header_len)
513 {
514 int ret = false;
515 unsigned char *p;
516 int pkt_len;
517
518 if (skb_linearize(skb) < 0)
519 goto out;
520
521 pkt_len = skb_headlen(skb);
522
523 if (pkt_len < header_len + BATADV_DHCP_OPTIONS_OFFSET + 1)
524 goto out;
525
526 p = skb->data + header_len + BATADV_DHCP_OPTIONS_OFFSET;
527 pkt_len -= header_len + BATADV_DHCP_OPTIONS_OFFSET + 1;
528
529 /* Access the dhcp option lists. Each entry is made up by:
530 * - octet 1: option type
531 * - octet 2: option data len (only if type != 255 and 0)
532 * - octet 3: option data
533 */
534 while (*p != 255 && !ret) {
535 /* p now points to the first octet: option type */
536 if (*p == 53) {
537 /* type 53 is the message type option.
538 * Jump the len octet and go to the data octet
539 */
540 if (pkt_len < 2)
541 goto out;
542 p += 2;
543
544 /* check if the message type is what we need */
545 if (*p == BATADV_DHCP_REQUEST)
546 ret = true;
547 break;
548 } else if (*p == 0) {
549 /* option type 0 (padding), just go forward */
550 if (pkt_len < 1)
551 goto out;
552 pkt_len--;
553 p++;
554 } else {
555 /* This is any other option. So we get the length... */
556 if (pkt_len < 1)
557 goto out;
558 pkt_len--;
559 p++;
560
561 /* ...and then we jump over the data */
562 if (pkt_len < 1 + (*p))
563 goto out;
564 pkt_len -= 1 + (*p);
565 p += 1 + (*p);
566 }
567 }
568 out:
569 return ret;
570 }
571
572 /* this call might reallocate skb data */
573 bool batadv_gw_is_dhcp_target(struct sk_buff *skb, unsigned int *header_len)
574 {
575 struct ethhdr *ethhdr;
576 struct iphdr *iphdr;
577 struct ipv6hdr *ipv6hdr;
578 struct udphdr *udphdr;
579
580 /* check for ethernet header */
581 if (!pskb_may_pull(skb, *header_len + ETH_HLEN))
582 return false;
583 ethhdr = (struct ethhdr *)skb->data;
584 *header_len += ETH_HLEN;
585
586 /* check for initial vlan header */
587 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
588 if (!pskb_may_pull(skb, *header_len + VLAN_HLEN))
589 return false;
590 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
591 *header_len += VLAN_HLEN;
592 }
593
594 /* check for ip header */
595 switch (ntohs(ethhdr->h_proto)) {
596 case ETH_P_IP:
597 if (!pskb_may_pull(skb, *header_len + sizeof(*iphdr)))
598 return false;
599 iphdr = (struct iphdr *)(skb->data + *header_len);
600 *header_len += iphdr->ihl * 4;
601
602 /* check for udp header */
603 if (iphdr->protocol != IPPROTO_UDP)
604 return false;
605
606 break;
607 case ETH_P_IPV6:
608 if (!pskb_may_pull(skb, *header_len + sizeof(*ipv6hdr)))
609 return false;
610 ipv6hdr = (struct ipv6hdr *)(skb->data + *header_len);
611 *header_len += sizeof(*ipv6hdr);
612
613 /* check for udp header */
614 if (ipv6hdr->nexthdr != IPPROTO_UDP)
615 return false;
616
617 break;
618 default:
619 return false;
620 }
621
622 if (!pskb_may_pull(skb, *header_len + sizeof(*udphdr)))
623 return false;
624
625 /* skb->data might have been reallocated by pskb_may_pull() */
626 ethhdr = (struct ethhdr *)skb->data;
627 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q)
628 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
629
630 udphdr = (struct udphdr *)(skb->data + *header_len);
631 *header_len += sizeof(*udphdr);
632
633 /* check for bootp port */
634 if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
635 (ntohs(udphdr->dest) != 67))
636 return false;
637
638 if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
639 (ntohs(udphdr->dest) != 547))
640 return false;
641
642 return true;
643 }
644
645 /* this call might reallocate skb data */
646 bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
647 struct sk_buff *skb)
648 {
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 struct ethhdr *ethhdr;
653 bool ret, out_of_range = false;
654 unsigned int header_len = 0;
655 uint8_t curr_tq_avg;
656
657 ret = batadv_gw_is_dhcp_target(skb, &header_len);
658 if (!ret)
659 goto out;
660
661 ethhdr = (struct ethhdr *)skb->data;
662 orig_dst_node = batadv_transtable_search(bat_priv, ethhdr->h_source,
663 ethhdr->h_dest);
664 if (!orig_dst_node)
665 goto out;
666
667 if (!orig_dst_node->gw_flags)
668 goto out;
669
670 ret = batadv_is_type_dhcprequest(skb, header_len);
671 if (!ret)
672 goto out;
673
674 switch (atomic_read(&bat_priv->gw_mode)) {
675 case BATADV_GW_MODE_SERVER:
676 /* If we are a GW then we are our best GW. We can artificially
677 * set the tq towards ourself as the maximum value
678 */
679 curr_tq_avg = BATADV_TQ_MAX_VALUE;
680 break;
681 case BATADV_GW_MODE_CLIENT:
682 curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
683 if (!curr_gw)
684 goto out;
685
686 /* packet is going to our gateway */
687 if (curr_gw->orig_node == orig_dst_node)
688 goto out;
689
690 /* If the dhcp packet has been sent to a different gw,
691 * we have to evaluate whether the old gw is still
692 * reliable enough
693 */
694 neigh_curr = batadv_find_router(bat_priv, curr_gw->orig_node,
695 NULL);
696 if (!neigh_curr)
697 goto out;
698
699 curr_tq_avg = neigh_curr->tq_avg;
700 break;
701 case BATADV_GW_MODE_OFF:
702 default:
703 goto out;
704 }
705
706 neigh_old = batadv_find_router(bat_priv, orig_dst_node, NULL);
707 if (!neigh_old)
708 goto out;
709
710 if (curr_tq_avg - neigh_old->tq_avg > BATADV_GW_THRESHOLD)
711 out_of_range = true;
712
713 out:
714 if (orig_dst_node)
715 batadv_orig_node_free_ref(orig_dst_node);
716 if (curr_gw)
717 batadv_gw_node_free_ref(curr_gw);
718 if (neigh_old)
719 batadv_neigh_node_free_ref(neigh_old);
720 if (neigh_curr)
721 batadv_neigh_node_free_ref(neigh_curr);
722 return out_of_range;
723 }
Linus' kernel tree