Merge branch 'batman-adv/next' of git://git.open-mesh.org/ecsv/linux-merge
[linux-3.10.git] / net / batman-adv / gateway_client.c
1 /*
2  * Copyright (C) 2009-2011 B.A.T.M.A.N. contributors:
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"
26 #include <linux/ip.h>
27 #include <linux/ipv6.h>
28 #include <linux/udp.h>
29 #include <linux/if_vlan.h>
30
31 static void gw_node_free_rcu(struct rcu_head *rcu)
32 {
33         struct gw_node *gw_node;
34
35         gw_node = container_of(rcu, struct gw_node, rcu);
36         kfree(gw_node);
37 }
38
39 static void gw_node_free_ref(struct gw_node *gw_node)
40 {
41         if (atomic_dec_and_test(&gw_node->refcount))
42                 call_rcu(&gw_node->rcu, gw_node_free_rcu);
43 }
44
45 void *gw_get_selected(struct bat_priv *bat_priv)
46 {
47         struct gw_node *curr_gateway_tmp;
48         struct orig_node *orig_node = NULL;
49
50         rcu_read_lock();
51         curr_gateway_tmp = rcu_dereference(bat_priv->curr_gw);
52         if (!curr_gateway_tmp)
53                 goto out;
54
55         orig_node = curr_gateway_tmp->orig_node;
56         if (!orig_node)
57                 goto out;
58
59         if (!atomic_inc_not_zero(&orig_node->refcount))
60                 orig_node = NULL;
61
62 out:
63         rcu_read_unlock();
64         return orig_node;
65 }
66
67 void gw_deselect(struct bat_priv *bat_priv)
68 {
69         struct gw_node *gw_node;
70
71         spin_lock_bh(&bat_priv->gw_list_lock);
72         gw_node = rcu_dereference(bat_priv->curr_gw);
73         rcu_assign_pointer(bat_priv->curr_gw, NULL);
74         spin_unlock_bh(&bat_priv->gw_list_lock);
75
76         if (gw_node)
77                 gw_node_free_ref(gw_node);
78 }
79
80 static void gw_select(struct bat_priv *bat_priv, struct gw_node *new_gw_node)
81 {
82         struct gw_node *curr_gw_node;
83
84         if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
85                 new_gw_node = NULL;
86
87         spin_lock_bh(&bat_priv->gw_list_lock);
88         curr_gw_node = rcu_dereference(bat_priv->curr_gw);
89         rcu_assign_pointer(bat_priv->curr_gw, new_gw_node);
90         spin_unlock_bh(&bat_priv->gw_list_lock);
91
92         if (curr_gw_node)
93                 gw_node_free_ref(curr_gw_node);
94 }
95
96 void gw_election(struct bat_priv *bat_priv)
97 {
98         struct hlist_node *node;
99         struct gw_node *gw_node, *curr_gw, *curr_gw_tmp = NULL;
100         uint8_t max_tq = 0;
101         uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
102         int down, up;
103
104         /**
105          * The batman daemon checks here if we already passed a full originator
106          * cycle in order to make sure we don't choose the first gateway we
107          * hear about. This check is based on the daemon's uptime which we
108          * don't have.
109          **/
110         if (atomic_read(&bat_priv->gw_mode) != GW_MODE_CLIENT)
111                 return;
112
113         rcu_read_lock();
114         curr_gw = rcu_dereference(bat_priv->curr_gw);
115         if (curr_gw) {
116                 rcu_read_unlock();
117                 return;
118         }
119
120         if (hlist_empty(&bat_priv->gw_list)) {
121
122                 if (curr_gw) {
123                         rcu_read_unlock();
124                         bat_dbg(DBG_BATMAN, bat_priv,
125                                 "Removing selected gateway - "
126                                 "no gateway in range\n");
127                         gw_deselect(bat_priv);
128                 } else
129                         rcu_read_unlock();
130
131                 return;
132         }
133
134         hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
135                 if (!gw_node->orig_node->router)
136                         continue;
137
138                 if (gw_node->deleted)
139                         continue;
140
141                 switch (atomic_read(&bat_priv->gw_sel_class)) {
142                 case 1: /* fast connection */
143                         gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags,
144                                              &down, &up);
145
146                         tmp_gw_factor = (gw_node->orig_node->router->tq_avg *
147                                          gw_node->orig_node->router->tq_avg *
148                                          down * 100 * 100) /
149                                          (TQ_LOCAL_WINDOW_SIZE *
150                                          TQ_LOCAL_WINDOW_SIZE * 64);
151
152                         if ((tmp_gw_factor > max_gw_factor) ||
153                             ((tmp_gw_factor == max_gw_factor) &&
154                              (gw_node->orig_node->router->tq_avg > max_tq)))
155                                 curr_gw_tmp = gw_node;
156                         break;
157
158                 default: /**
159                           * 2:  stable connection (use best statistic)
160                           * 3:  fast-switch (use best statistic but change as
161                           *     soon as a better gateway appears)
162                           * XX: late-switch (use best statistic but change as
163                           *     soon as a better gateway appears which has
164                           *     $routing_class more tq points)
165                           **/
166                         if (gw_node->orig_node->router->tq_avg > max_tq)
167                                 curr_gw_tmp = gw_node;
168                         break;
169                 }
170
171                 if (gw_node->orig_node->router->tq_avg > max_tq)
172                         max_tq = gw_node->orig_node->router->tq_avg;
173
174                 if (tmp_gw_factor > max_gw_factor)
175                         max_gw_factor = tmp_gw_factor;
176         }
177
178         if (curr_gw != curr_gw_tmp) {
179                 if ((curr_gw) && (!curr_gw_tmp))
180                         bat_dbg(DBG_BATMAN, bat_priv,
181                                 "Removing selected gateway - "
182                                 "no gateway in range\n");
183                 else if ((!curr_gw) && (curr_gw_tmp))
184                         bat_dbg(DBG_BATMAN, bat_priv,
185                                 "Adding route to gateway %pM "
186                                 "(gw_flags: %i, tq: %i)\n",
187                                 curr_gw_tmp->orig_node->orig,
188                                 curr_gw_tmp->orig_node->gw_flags,
189                                 curr_gw_tmp->orig_node->router->tq_avg);
190                 else
191                         bat_dbg(DBG_BATMAN, bat_priv,
192                                 "Changing route to gateway %pM "
193                                 "(gw_flags: %i, tq: %i)\n",
194                                 curr_gw_tmp->orig_node->orig,
195                                 curr_gw_tmp->orig_node->gw_flags,
196                                 curr_gw_tmp->orig_node->router->tq_avg);
197
198                 gw_select(bat_priv, curr_gw_tmp);
199         }
200
201         rcu_read_unlock();
202 }
203
204 void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node)
205 {
206         struct gw_node *curr_gateway_tmp;
207         uint8_t gw_tq_avg, orig_tq_avg;
208
209         rcu_read_lock();
210         curr_gateway_tmp = rcu_dereference(bat_priv->curr_gw);
211         if (!curr_gateway_tmp)
212                 goto out_rcu;
213
214         if (!curr_gateway_tmp->orig_node)
215                 goto deselect_rcu;
216
217         if (!curr_gateway_tmp->orig_node->router)
218                 goto deselect_rcu;
219
220         /* this node already is the gateway */
221         if (curr_gateway_tmp->orig_node == orig_node)
222                 goto out_rcu;
223
224         if (!orig_node->router)
225                 goto out_rcu;
226
227         gw_tq_avg = curr_gateway_tmp->orig_node->router->tq_avg;
228         rcu_read_unlock();
229
230         orig_tq_avg = orig_node->router->tq_avg;
231
232         /* the TQ value has to be better */
233         if (orig_tq_avg < gw_tq_avg)
234                 goto out;
235
236         /**
237          * if the routing class is greater than 3 the value tells us how much
238          * greater the TQ value of the new gateway must be
239          **/
240         if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
241             (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
242                 goto out;
243
244         bat_dbg(DBG_BATMAN, bat_priv,
245                 "Restarting gateway selection: better gateway found (tq curr: "
246                 "%i, tq new: %i)\n",
247                 gw_tq_avg, orig_tq_avg);
248         goto deselect;
249
250 out_rcu:
251         rcu_read_unlock();
252         goto out;
253 deselect_rcu:
254         rcu_read_unlock();
255 deselect:
256         gw_deselect(bat_priv);
257 out:
258         return;
259 }
260
261 static void gw_node_add(struct bat_priv *bat_priv,
262                         struct orig_node *orig_node, uint8_t new_gwflags)
263 {
264         struct gw_node *gw_node;
265         int down, up;
266
267         gw_node = kmalloc(sizeof(struct gw_node), GFP_ATOMIC);
268         if (!gw_node)
269                 return;
270
271         memset(gw_node, 0, sizeof(struct gw_node));
272         INIT_HLIST_NODE(&gw_node->list);
273         gw_node->orig_node = orig_node;
274         atomic_set(&gw_node->refcount, 1);
275
276         spin_lock_bh(&bat_priv->gw_list_lock);
277         hlist_add_head_rcu(&gw_node->list, &bat_priv->gw_list);
278         spin_unlock_bh(&bat_priv->gw_list_lock);
279
280         gw_bandwidth_to_kbit(new_gwflags, &down, &up);
281         bat_dbg(DBG_BATMAN, bat_priv,
282                 "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
283                 orig_node->orig, new_gwflags,
284                 (down > 2048 ? down / 1024 : down),
285                 (down > 2048 ? "MBit" : "KBit"),
286                 (up > 2048 ? up / 1024 : up),
287                 (up > 2048 ? "MBit" : "KBit"));
288 }
289
290 void gw_node_update(struct bat_priv *bat_priv,
291                     struct orig_node *orig_node, uint8_t new_gwflags)
292 {
293         struct hlist_node *node;
294         struct gw_node *gw_node;
295
296         rcu_read_lock();
297         hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
298                 if (gw_node->orig_node != orig_node)
299                         continue;
300
301                 bat_dbg(DBG_BATMAN, bat_priv,
302                         "Gateway class of originator %pM changed from "
303                         "%i to %i\n",
304                         orig_node->orig, gw_node->orig_node->gw_flags,
305                         new_gwflags);
306
307                 gw_node->deleted = 0;
308
309                 if (new_gwflags == 0) {
310                         gw_node->deleted = jiffies;
311                         bat_dbg(DBG_BATMAN, bat_priv,
312                                 "Gateway %pM removed from gateway list\n",
313                                 orig_node->orig);
314
315                         if (gw_node == rcu_dereference(bat_priv->curr_gw)) {
316                                 rcu_read_unlock();
317                                 gw_deselect(bat_priv);
318                                 return;
319                         }
320                 }
321
322                 rcu_read_unlock();
323                 return;
324         }
325         rcu_read_unlock();
326
327         if (new_gwflags == 0)
328                 return;
329
330         gw_node_add(bat_priv, orig_node, new_gwflags);
331 }
332
333 void gw_node_delete(struct bat_priv *bat_priv, struct orig_node *orig_node)
334 {
335         return gw_node_update(bat_priv, orig_node, 0);
336 }
337
338 void gw_node_purge(struct bat_priv *bat_priv)
339 {
340         struct gw_node *gw_node;
341         struct hlist_node *node, *node_tmp;
342         unsigned long timeout = 2 * PURGE_TIMEOUT * HZ;
343
344         spin_lock_bh(&bat_priv->gw_list_lock);
345
346         hlist_for_each_entry_safe(gw_node, node, node_tmp,
347                                   &bat_priv->gw_list, list) {
348                 if (((!gw_node->deleted) ||
349                      (time_before(jiffies, gw_node->deleted + timeout))) &&
350                     atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE)
351                         continue;
352
353                 if (rcu_dereference(bat_priv->curr_gw) == gw_node)
354                         gw_deselect(bat_priv);
355
356                 hlist_del_rcu(&gw_node->list);
357                 gw_node_free_ref(gw_node);
358         }
359
360
361         spin_unlock_bh(&bat_priv->gw_list_lock);
362 }
363
364 static int _write_buffer_text(struct bat_priv *bat_priv,
365                               struct seq_file *seq, struct gw_node *gw_node)
366 {
367         struct gw_node *curr_gw;
368         int down, up, ret;
369
370         gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
371
372         rcu_read_lock();
373         curr_gw = rcu_dereference(bat_priv->curr_gw);
374
375         ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
376                        (curr_gw == gw_node ? "=>" : "  "),
377                        gw_node->orig_node->orig,
378                        gw_node->orig_node->router->tq_avg,
379                        gw_node->orig_node->router->addr,
380                        gw_node->orig_node->router->if_incoming->net_dev->name,
381                        gw_node->orig_node->gw_flags,
382                        (down > 2048 ? down / 1024 : down),
383                        (down > 2048 ? "MBit" : "KBit"),
384                        (up > 2048 ? up / 1024 : up),
385                        (up > 2048 ? "MBit" : "KBit"));
386
387         rcu_read_unlock();
388         return ret;
389 }
390
391 int gw_client_seq_print_text(struct seq_file *seq, void *offset)
392 {
393         struct net_device *net_dev = (struct net_device *)seq->private;
394         struct bat_priv *bat_priv = netdev_priv(net_dev);
395         struct gw_node *gw_node;
396         struct hlist_node *node;
397         int gw_count = 0;
398
399         if (!bat_priv->primary_if) {
400
401                 return seq_printf(seq, "BATMAN mesh %s disabled - please "
402                                   "specify interfaces to enable it\n",
403                                   net_dev->name);
404         }
405
406         if (bat_priv->primary_if->if_status != IF_ACTIVE) {
407
408                 return seq_printf(seq, "BATMAN mesh %s disabled - "
409                                        "primary interface not active\n",
410                                        net_dev->name);
411         }
412
413         seq_printf(seq, "      %-12s (%s/%i) %17s [%10s]: gw_class ... "
414                    "[B.A.T.M.A.N. adv %s%s, MainIF/MAC: %s/%pM (%s)]\n",
415                    "Gateway", "#", TQ_MAX_VALUE, "Nexthop",
416                    "outgoingIF", SOURCE_VERSION, REVISION_VERSION_STR,
417                    bat_priv->primary_if->net_dev->name,
418                    bat_priv->primary_if->net_dev->dev_addr, net_dev->name);
419
420         rcu_read_lock();
421         hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
422                 if (gw_node->deleted)
423                         continue;
424
425                 if (!gw_node->orig_node->router)
426                         continue;
427
428                 _write_buffer_text(bat_priv, seq, gw_node);
429                 gw_count++;
430         }
431         rcu_read_unlock();
432
433         if (gw_count == 0)
434                 seq_printf(seq, "No gateways in range ...\n");
435
436         return 0;
437 }
438
439 int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb)
440 {
441         struct ethhdr *ethhdr;
442         struct iphdr *iphdr;
443         struct ipv6hdr *ipv6hdr;
444         struct udphdr *udphdr;
445         unsigned int header_len = 0;
446
447         if (atomic_read(&bat_priv->gw_mode) == GW_MODE_OFF)
448                 return 0;
449
450         /* check for ethernet header */
451         if (!pskb_may_pull(skb, header_len + ETH_HLEN))
452                 return 0;
453         ethhdr = (struct ethhdr *)skb->data;
454         header_len += ETH_HLEN;
455
456         /* check for initial vlan header */
457         if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
458                 if (!pskb_may_pull(skb, header_len + VLAN_HLEN))
459                         return 0;
460                 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
461                 header_len += VLAN_HLEN;
462         }
463
464         /* check for ip header */
465         switch (ntohs(ethhdr->h_proto)) {
466         case ETH_P_IP:
467                 if (!pskb_may_pull(skb, header_len + sizeof(struct iphdr)))
468                         return 0;
469                 iphdr = (struct iphdr *)(skb->data + header_len);
470                 header_len += iphdr->ihl * 4;
471
472                 /* check for udp header */
473                 if (iphdr->protocol != IPPROTO_UDP)
474                         return 0;
475
476                 break;
477         case ETH_P_IPV6:
478                 if (!pskb_may_pull(skb, header_len + sizeof(struct ipv6hdr)))
479                         return 0;
480                 ipv6hdr = (struct ipv6hdr *)(skb->data + header_len);
481                 header_len += sizeof(struct ipv6hdr);
482
483                 /* check for udp header */
484                 if (ipv6hdr->nexthdr != IPPROTO_UDP)
485                         return 0;
486
487                 break;
488         default:
489                 return 0;
490         }
491
492         if (!pskb_may_pull(skb, header_len + sizeof(struct udphdr)))
493                 return 0;
494         udphdr = (struct udphdr *)(skb->data + header_len);
495         header_len += sizeof(struct udphdr);
496
497         /* check for bootp port */
498         if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
499              (ntohs(udphdr->dest) != 67))
500                 return 0;
501
502         if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
503             (ntohs(udphdr->dest) != 547))
504                 return 0;
505
506         if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER)
507                 return -1;
508
509         rcu_read_lock();
510         if (!rcu_dereference(bat_priv->curr_gw)) {
511                 rcu_read_unlock();
512                 return 0;
513         }
514         rcu_read_unlock();
515
516         return 1;
517 }