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c6c8fea2 | 1 | /* |
64afe353 | 2 | * Copyright (C) 2009-2011 B.A.T.M.A.N. contributors: |
c6c8fea2 SE |
3 | * |
4 | * Marek Lindner | |
5 | * | |
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. | |
9 | * | |
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. | |
14 | * | |
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 | |
18 | * 02110-1301, USA | |
19 | * | |
20 | */ | |
21 | ||
22 | #include "main.h" | |
23 | #include "gateway_client.h" | |
24 | #include "gateway_common.h" | |
25 | #include "hard-interface.h" | |
57f0c07c | 26 | #include "originator.h" |
c6c8fea2 SE |
27 | #include <linux/ip.h> |
28 | #include <linux/ipv6.h> | |
29 | #include <linux/udp.h> | |
30 | #include <linux/if_vlan.h> | |
31 | ||
25b6d3c1 | 32 | static void gw_node_free_rcu(struct rcu_head *rcu) |
c6c8fea2 SE |
33 | { |
34 | struct gw_node *gw_node; | |
35 | ||
25b6d3c1 | 36 | gw_node = container_of(rcu, struct gw_node, rcu); |
c6c8fea2 SE |
37 | kfree(gw_node); |
38 | } | |
39 | ||
25b6d3c1 | 40 | static void gw_node_free_ref(struct gw_node *gw_node) |
c6c8fea2 | 41 | { |
25b6d3c1 ML |
42 | if (atomic_dec_and_test(&gw_node->refcount)) |
43 | call_rcu(&gw_node->rcu, gw_node_free_rcu); | |
c6c8fea2 SE |
44 | } |
45 | ||
4c804850 | 46 | struct orig_node *gw_get_selected(struct bat_priv *bat_priv) |
c6c8fea2 | 47 | { |
5d02b3cd LL |
48 | struct gw_node *curr_gateway_tmp; |
49 | struct orig_node *orig_node = NULL; | |
c6c8fea2 | 50 | |
5d02b3cd LL |
51 | rcu_read_lock(); |
52 | curr_gateway_tmp = rcu_dereference(bat_priv->curr_gw); | |
c6c8fea2 | 53 | if (!curr_gateway_tmp) |
5d02b3cd LL |
54 | goto out; |
55 | ||
56 | orig_node = curr_gateway_tmp->orig_node; | |
7b36e8ee ML |
57 | if (!orig_node) |
58 | goto out; | |
c6c8fea2 | 59 | |
7b36e8ee ML |
60 | if (!atomic_inc_not_zero(&orig_node->refcount)) |
61 | orig_node = NULL; | |
43c70ad5 | 62 | |
5d02b3cd LL |
63 | out: |
64 | rcu_read_unlock(); | |
65 | return orig_node; | |
c6c8fea2 SE |
66 | } |
67 | ||
68 | void gw_deselect(struct bat_priv *bat_priv) | |
69 | { | |
5d02b3cd | 70 | struct gw_node *gw_node; |
c6c8fea2 | 71 | |
5d02b3cd LL |
72 | spin_lock_bh(&bat_priv->gw_list_lock); |
73 | gw_node = rcu_dereference(bat_priv->curr_gw); | |
74 | rcu_assign_pointer(bat_priv->curr_gw, NULL); | |
75 | spin_unlock_bh(&bat_priv->gw_list_lock); | |
c6c8fea2 SE |
76 | |
77 | if (gw_node) | |
25b6d3c1 | 78 | gw_node_free_ref(gw_node); |
c6c8fea2 SE |
79 | } |
80 | ||
25b6d3c1 | 81 | static void gw_select(struct bat_priv *bat_priv, struct gw_node *new_gw_node) |
c6c8fea2 | 82 | { |
5d02b3cd | 83 | struct gw_node *curr_gw_node; |
c6c8fea2 | 84 | |
25b6d3c1 ML |
85 | if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount)) |
86 | new_gw_node = NULL; | |
c6c8fea2 | 87 | |
5d02b3cd LL |
88 | spin_lock_bh(&bat_priv->gw_list_lock); |
89 | curr_gw_node = rcu_dereference(bat_priv->curr_gw); | |
90 | rcu_assign_pointer(bat_priv->curr_gw, new_gw_node); | |
91 | spin_unlock_bh(&bat_priv->gw_list_lock); | |
25b6d3c1 ML |
92 | |
93 | if (curr_gw_node) | |
94 | gw_node_free_ref(curr_gw_node); | |
c6c8fea2 SE |
95 | } |
96 | ||
97 | void gw_election(struct bat_priv *bat_priv) | |
98 | { | |
99 | struct hlist_node *node; | |
5d02b3cd | 100 | struct gw_node *gw_node, *curr_gw, *curr_gw_tmp = NULL; |
e1a5382f | 101 | struct neigh_node *router; |
c6c8fea2 SE |
102 | uint8_t max_tq = 0; |
103 | uint32_t max_gw_factor = 0, tmp_gw_factor = 0; | |
104 | int down, up; | |
105 | ||
106 | /** | |
107 | * The batman daemon checks here if we already passed a full originator | |
108 | * cycle in order to make sure we don't choose the first gateway we | |
109 | * hear about. This check is based on the daemon's uptime which we | |
110 | * don't have. | |
111 | **/ | |
112 | if (atomic_read(&bat_priv->gw_mode) != GW_MODE_CLIENT) | |
113 | return; | |
114 | ||
5d02b3cd LL |
115 | rcu_read_lock(); |
116 | curr_gw = rcu_dereference(bat_priv->curr_gw); | |
117 | if (curr_gw) { | |
118 | rcu_read_unlock(); | |
c6c8fea2 | 119 | return; |
5d02b3cd | 120 | } |
c6c8fea2 | 121 | |
c6c8fea2 | 122 | if (hlist_empty(&bat_priv->gw_list)) { |
c6c8fea2 | 123 | |
5d02b3cd LL |
124 | if (curr_gw) { |
125 | rcu_read_unlock(); | |
c6c8fea2 SE |
126 | bat_dbg(DBG_BATMAN, bat_priv, |
127 | "Removing selected gateway - " | |
128 | "no gateway in range\n"); | |
129 | gw_deselect(bat_priv); | |
5d02b3cd LL |
130 | } else |
131 | rcu_read_unlock(); | |
c6c8fea2 SE |
132 | |
133 | return; | |
134 | } | |
135 | ||
136 | hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) { | |
e1a5382f | 137 | if (gw_node->deleted) |
c6c8fea2 SE |
138 | continue; |
139 | ||
e1a5382f LL |
140 | router = orig_node_get_router(gw_node->orig_node); |
141 | if (!router) | |
c6c8fea2 SE |
142 | continue; |
143 | ||
144 | switch (atomic_read(&bat_priv->gw_sel_class)) { | |
145 | case 1: /* fast connection */ | |
146 | gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, | |
147 | &down, &up); | |
148 | ||
e1a5382f | 149 | tmp_gw_factor = (router->tq_avg * router->tq_avg * |
c6c8fea2 SE |
150 | down * 100 * 100) / |
151 | (TQ_LOCAL_WINDOW_SIZE * | |
152 | TQ_LOCAL_WINDOW_SIZE * 64); | |
153 | ||
154 | if ((tmp_gw_factor > max_gw_factor) || | |
155 | ((tmp_gw_factor == max_gw_factor) && | |
e1a5382f | 156 | (router->tq_avg > max_tq))) |
c6c8fea2 SE |
157 | curr_gw_tmp = gw_node; |
158 | break; | |
159 | ||
160 | default: /** | |
161 | * 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 | **/ | |
e1a5382f | 168 | if (router->tq_avg > max_tq) |
c6c8fea2 SE |
169 | curr_gw_tmp = gw_node; |
170 | break; | |
171 | } | |
172 | ||
e1a5382f LL |
173 | if (router->tq_avg > max_tq) |
174 | max_tq = router->tq_avg; | |
c6c8fea2 SE |
175 | |
176 | if (tmp_gw_factor > max_gw_factor) | |
177 | max_gw_factor = tmp_gw_factor; | |
e1a5382f LL |
178 | |
179 | neigh_node_free_ref(router); | |
c6c8fea2 SE |
180 | } |
181 | ||
5d02b3cd | 182 | if (curr_gw != curr_gw_tmp) { |
e1a5382f LL |
183 | router = orig_node_get_router(curr_gw_tmp->orig_node); |
184 | if (!router) | |
185 | goto out; | |
186 | ||
5d02b3cd | 187 | if ((curr_gw) && (!curr_gw_tmp)) |
c6c8fea2 SE |
188 | bat_dbg(DBG_BATMAN, bat_priv, |
189 | "Removing selected gateway - " | |
190 | "no gateway in range\n"); | |
5d02b3cd | 191 | else if ((!curr_gw) && (curr_gw_tmp)) |
c6c8fea2 SE |
192 | bat_dbg(DBG_BATMAN, bat_priv, |
193 | "Adding route to gateway %pM " | |
194 | "(gw_flags: %i, tq: %i)\n", | |
195 | curr_gw_tmp->orig_node->orig, | |
196 | curr_gw_tmp->orig_node->gw_flags, | |
e1a5382f | 197 | router->tq_avg); |
c6c8fea2 SE |
198 | else |
199 | bat_dbg(DBG_BATMAN, bat_priv, | |
200 | "Changing route to gateway %pM " | |
201 | "(gw_flags: %i, tq: %i)\n", | |
202 | curr_gw_tmp->orig_node->orig, | |
203 | curr_gw_tmp->orig_node->gw_flags, | |
e1a5382f | 204 | router->tq_avg); |
c6c8fea2 | 205 | |
e1a5382f | 206 | neigh_node_free_ref(router); |
25b6d3c1 | 207 | gw_select(bat_priv, curr_gw_tmp); |
c6c8fea2 SE |
208 | } |
209 | ||
e1a5382f | 210 | out: |
c6c8fea2 | 211 | rcu_read_unlock(); |
c6c8fea2 SE |
212 | } |
213 | ||
214 | void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node) | |
215 | { | |
57f0c07c | 216 | struct orig_node *curr_gw_orig; |
e1a5382f | 217 | struct neigh_node *router_gw = NULL, *router_orig = NULL; |
c6c8fea2 SE |
218 | uint8_t gw_tq_avg, orig_tq_avg; |
219 | ||
57f0c07c LL |
220 | curr_gw_orig = gw_get_selected(bat_priv); |
221 | if (!curr_gw_orig) | |
222 | goto deselect; | |
c6c8fea2 | 223 | |
e1a5382f LL |
224 | router_gw = orig_node_get_router(curr_gw_orig); |
225 | if (!router_gw) | |
226 | goto deselect; | |
c6c8fea2 SE |
227 | |
228 | /* this node already is the gateway */ | |
57f0c07c | 229 | if (curr_gw_orig == orig_node) |
e1a5382f | 230 | goto out; |
c6c8fea2 | 231 | |
e1a5382f LL |
232 | router_orig = orig_node_get_router(orig_node); |
233 | if (!router_orig) | |
234 | goto out; | |
5d02b3cd | 235 | |
e1a5382f LL |
236 | gw_tq_avg = router_gw->tq_avg; |
237 | orig_tq_avg = router_orig->tq_avg; | |
c6c8fea2 SE |
238 | |
239 | /* the TQ value has to be better */ | |
240 | if (orig_tq_avg < gw_tq_avg) | |
5d02b3cd | 241 | goto out; |
c6c8fea2 SE |
242 | |
243 | /** | |
244 | * if the routing class is greater than 3 the value tells us how much | |
245 | * greater the TQ value of the new gateway must be | |
246 | **/ | |
247 | if ((atomic_read(&bat_priv->gw_sel_class) > 3) && | |
248 | (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class))) | |
5d02b3cd | 249 | goto out; |
c6c8fea2 SE |
250 | |
251 | bat_dbg(DBG_BATMAN, bat_priv, | |
252 | "Restarting gateway selection: better gateway found (tq curr: " | |
253 | "%i, tq new: %i)\n", | |
254 | gw_tq_avg, orig_tq_avg); | |
255 | ||
256 | deselect: | |
257 | gw_deselect(bat_priv); | |
5d02b3cd | 258 | out: |
57f0c07c LL |
259 | if (curr_gw_orig) |
260 | orig_node_free_ref(curr_gw_orig); | |
e1a5382f LL |
261 | if (router_gw) |
262 | neigh_node_free_ref(router_gw); | |
263 | if (router_orig) | |
264 | neigh_node_free_ref(router_orig); | |
57f0c07c | 265 | |
5d02b3cd | 266 | return; |
c6c8fea2 SE |
267 | } |
268 | ||
269 | static void gw_node_add(struct bat_priv *bat_priv, | |
270 | struct orig_node *orig_node, uint8_t new_gwflags) | |
271 | { | |
272 | struct gw_node *gw_node; | |
273 | int down, up; | |
274 | ||
275 | gw_node = kmalloc(sizeof(struct gw_node), GFP_ATOMIC); | |
276 | if (!gw_node) | |
277 | return; | |
278 | ||
279 | memset(gw_node, 0, sizeof(struct gw_node)); | |
280 | INIT_HLIST_NODE(&gw_node->list); | |
281 | gw_node->orig_node = orig_node; | |
25b6d3c1 | 282 | atomic_set(&gw_node->refcount, 1); |
c6c8fea2 SE |
283 | |
284 | spin_lock_bh(&bat_priv->gw_list_lock); | |
285 | hlist_add_head_rcu(&gw_node->list, &bat_priv->gw_list); | |
286 | spin_unlock_bh(&bat_priv->gw_list_lock); | |
287 | ||
288 | gw_bandwidth_to_kbit(new_gwflags, &down, &up); | |
289 | bat_dbg(DBG_BATMAN, bat_priv, | |
290 | "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n", | |
291 | orig_node->orig, new_gwflags, | |
292 | (down > 2048 ? down / 1024 : down), | |
293 | (down > 2048 ? "MBit" : "KBit"), | |
294 | (up > 2048 ? up / 1024 : up), | |
295 | (up > 2048 ? "MBit" : "KBit")); | |
296 | } | |
297 | ||
298 | void gw_node_update(struct bat_priv *bat_priv, | |
299 | struct orig_node *orig_node, uint8_t new_gwflags) | |
300 | { | |
301 | struct hlist_node *node; | |
302 | struct gw_node *gw_node; | |
303 | ||
304 | rcu_read_lock(); | |
305 | hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) { | |
306 | if (gw_node->orig_node != orig_node) | |
307 | continue; | |
308 | ||
309 | bat_dbg(DBG_BATMAN, bat_priv, | |
310 | "Gateway class of originator %pM changed from " | |
311 | "%i to %i\n", | |
312 | orig_node->orig, gw_node->orig_node->gw_flags, | |
313 | new_gwflags); | |
314 | ||
315 | gw_node->deleted = 0; | |
316 | ||
317 | if (new_gwflags == 0) { | |
318 | gw_node->deleted = jiffies; | |
319 | bat_dbg(DBG_BATMAN, bat_priv, | |
320 | "Gateway %pM removed from gateway list\n", | |
321 | orig_node->orig); | |
322 | ||
5d02b3cd | 323 | if (gw_node == rcu_dereference(bat_priv->curr_gw)) { |
c6c8fea2 SE |
324 | rcu_read_unlock(); |
325 | gw_deselect(bat_priv); | |
326 | return; | |
327 | } | |
328 | } | |
329 | ||
330 | rcu_read_unlock(); | |
331 | return; | |
332 | } | |
333 | rcu_read_unlock(); | |
334 | ||
335 | if (new_gwflags == 0) | |
336 | return; | |
337 | ||
338 | gw_node_add(bat_priv, orig_node, new_gwflags); | |
339 | } | |
340 | ||
341 | void gw_node_delete(struct bat_priv *bat_priv, struct orig_node *orig_node) | |
342 | { | |
343 | return gw_node_update(bat_priv, orig_node, 0); | |
344 | } | |
345 | ||
346 | void gw_node_purge(struct bat_priv *bat_priv) | |
347 | { | |
348 | struct gw_node *gw_node; | |
349 | struct hlist_node *node, *node_tmp; | |
350 | unsigned long timeout = 2 * PURGE_TIMEOUT * HZ; | |
351 | ||
352 | spin_lock_bh(&bat_priv->gw_list_lock); | |
353 | ||
354 | hlist_for_each_entry_safe(gw_node, node, node_tmp, | |
355 | &bat_priv->gw_list, list) { | |
356 | if (((!gw_node->deleted) || | |
357 | (time_before(jiffies, gw_node->deleted + timeout))) && | |
358 | atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE) | |
359 | continue; | |
360 | ||
5d02b3cd | 361 | if (rcu_dereference(bat_priv->curr_gw) == gw_node) |
c6c8fea2 SE |
362 | gw_deselect(bat_priv); |
363 | ||
364 | hlist_del_rcu(&gw_node->list); | |
25b6d3c1 | 365 | gw_node_free_ref(gw_node); |
c6c8fea2 SE |
366 | } |
367 | ||
368 | ||
369 | spin_unlock_bh(&bat_priv->gw_list_lock); | |
370 | } | |
371 | ||
e1a5382f LL |
372 | /** |
373 | * fails if orig_node has no router | |
374 | */ | |
c6c8fea2 SE |
375 | static int _write_buffer_text(struct bat_priv *bat_priv, |
376 | struct seq_file *seq, struct gw_node *gw_node) | |
377 | { | |
5d02b3cd | 378 | struct gw_node *curr_gw; |
e1a5382f LL |
379 | struct neigh_node *router; |
380 | int down, up, ret = -1; | |
c6c8fea2 SE |
381 | |
382 | gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up); | |
383 | ||
e1a5382f LL |
384 | router = orig_node_get_router(gw_node->orig_node); |
385 | if (!router) | |
386 | goto out; | |
387 | ||
5d02b3cd LL |
388 | rcu_read_lock(); |
389 | curr_gw = rcu_dereference(bat_priv->curr_gw); | |
390 | ||
391 | ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n", | |
392 | (curr_gw == gw_node ? "=>" : " "), | |
c6c8fea2 | 393 | gw_node->orig_node->orig, |
e1a5382f LL |
394 | router->tq_avg, router->addr, |
395 | router->if_incoming->net_dev->name, | |
c6c8fea2 SE |
396 | gw_node->orig_node->gw_flags, |
397 | (down > 2048 ? down / 1024 : down), | |
398 | (down > 2048 ? "MBit" : "KBit"), | |
399 | (up > 2048 ? up / 1024 : up), | |
400 | (up > 2048 ? "MBit" : "KBit")); | |
5d02b3cd LL |
401 | |
402 | rcu_read_unlock(); | |
e1a5382f LL |
403 | neigh_node_free_ref(router); |
404 | out: | |
5d02b3cd | 405 | return ret; |
c6c8fea2 SE |
406 | } |
407 | ||
408 | int gw_client_seq_print_text(struct seq_file *seq, void *offset) | |
409 | { | |
410 | struct net_device *net_dev = (struct net_device *)seq->private; | |
411 | struct bat_priv *bat_priv = netdev_priv(net_dev); | |
412 | struct gw_node *gw_node; | |
413 | struct hlist_node *node; | |
414 | int gw_count = 0; | |
415 | ||
416 | if (!bat_priv->primary_if) { | |
417 | ||
418 | return seq_printf(seq, "BATMAN mesh %s disabled - please " | |
419 | "specify interfaces to enable it\n", | |
420 | net_dev->name); | |
421 | } | |
422 | ||
423 | if (bat_priv->primary_if->if_status != IF_ACTIVE) { | |
424 | ||
425 | return seq_printf(seq, "BATMAN mesh %s disabled - " | |
426 | "primary interface not active\n", | |
427 | net_dev->name); | |
428 | } | |
429 | ||
430 | seq_printf(seq, " %-12s (%s/%i) %17s [%10s]: gw_class ... " | |
431 | "[B.A.T.M.A.N. adv %s%s, MainIF/MAC: %s/%pM (%s)]\n", | |
432 | "Gateway", "#", TQ_MAX_VALUE, "Nexthop", | |
433 | "outgoingIF", SOURCE_VERSION, REVISION_VERSION_STR, | |
434 | bat_priv->primary_if->net_dev->name, | |
435 | bat_priv->primary_if->net_dev->dev_addr, net_dev->name); | |
436 | ||
437 | rcu_read_lock(); | |
438 | hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) { | |
439 | if (gw_node->deleted) | |
440 | continue; | |
441 | ||
e1a5382f LL |
442 | /* fails if orig_node has no router */ |
443 | if (_write_buffer_text(bat_priv, seq, gw_node) < 0) | |
c6c8fea2 SE |
444 | continue; |
445 | ||
c6c8fea2 SE |
446 | gw_count++; |
447 | } | |
448 | rcu_read_unlock(); | |
449 | ||
450 | if (gw_count == 0) | |
451 | seq_printf(seq, "No gateways in range ...\n"); | |
452 | ||
453 | return 0; | |
454 | } | |
455 | ||
456 | int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb) | |
457 | { | |
458 | struct ethhdr *ethhdr; | |
459 | struct iphdr *iphdr; | |
460 | struct ipv6hdr *ipv6hdr; | |
461 | struct udphdr *udphdr; | |
462 | unsigned int header_len = 0; | |
463 | ||
464 | if (atomic_read(&bat_priv->gw_mode) == GW_MODE_OFF) | |
465 | return 0; | |
466 | ||
467 | /* check for ethernet header */ | |
468 | if (!pskb_may_pull(skb, header_len + ETH_HLEN)) | |
469 | return 0; | |
470 | ethhdr = (struct ethhdr *)skb->data; | |
471 | header_len += ETH_HLEN; | |
472 | ||
473 | /* check for initial vlan header */ | |
474 | if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) { | |
475 | if (!pskb_may_pull(skb, header_len + VLAN_HLEN)) | |
476 | return 0; | |
477 | ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN); | |
478 | header_len += VLAN_HLEN; | |
479 | } | |
480 | ||
481 | /* check for ip header */ | |
482 | switch (ntohs(ethhdr->h_proto)) { | |
483 | case ETH_P_IP: | |
484 | if (!pskb_may_pull(skb, header_len + sizeof(struct iphdr))) | |
485 | return 0; | |
486 | iphdr = (struct iphdr *)(skb->data + header_len); | |
487 | header_len += iphdr->ihl * 4; | |
488 | ||
489 | /* check for udp header */ | |
490 | if (iphdr->protocol != IPPROTO_UDP) | |
491 | return 0; | |
492 | ||
493 | break; | |
494 | case ETH_P_IPV6: | |
495 | if (!pskb_may_pull(skb, header_len + sizeof(struct ipv6hdr))) | |
496 | return 0; | |
497 | ipv6hdr = (struct ipv6hdr *)(skb->data + header_len); | |
498 | header_len += sizeof(struct ipv6hdr); | |
499 | ||
500 | /* check for udp header */ | |
501 | if (ipv6hdr->nexthdr != IPPROTO_UDP) | |
502 | return 0; | |
503 | ||
504 | break; | |
505 | default: | |
506 | return 0; | |
507 | } | |
508 | ||
509 | if (!pskb_may_pull(skb, header_len + sizeof(struct udphdr))) | |
510 | return 0; | |
511 | udphdr = (struct udphdr *)(skb->data + header_len); | |
512 | header_len += sizeof(struct udphdr); | |
513 | ||
514 | /* check for bootp port */ | |
515 | if ((ntohs(ethhdr->h_proto) == ETH_P_IP) && | |
516 | (ntohs(udphdr->dest) != 67)) | |
517 | return 0; | |
518 | ||
519 | if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) && | |
520 | (ntohs(udphdr->dest) != 547)) | |
521 | return 0; | |
522 | ||
523 | if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER) | |
524 | return -1; | |
525 | ||
5d02b3cd LL |
526 | rcu_read_lock(); |
527 | if (!rcu_dereference(bat_priv->curr_gw)) { | |
528 | rcu_read_unlock(); | |
c6c8fea2 | 529 | return 0; |
5d02b3cd LL |
530 | } |
531 | rcu_read_unlock(); | |
c6c8fea2 SE |
532 | |
533 | return 1; | |
534 | } |