ipv4: Remove flowi from struct rtable.
[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_ref(struct kref *refcount)
32 {
33         struct gw_node *gw_node;
34
35         gw_node = container_of(refcount, struct gw_node, refcount);
36         kfree(gw_node);
37 }
38
39 static void gw_node_free_rcu(struct rcu_head *rcu)
40 {
41         struct gw_node *gw_node;
42
43         gw_node = container_of(rcu, struct gw_node, rcu);
44         kref_put(&gw_node->refcount, gw_node_free_ref);
45 }
46
47 void *gw_get_selected(struct bat_priv *bat_priv)
48 {
49         struct gw_node *curr_gateway_tmp = bat_priv->curr_gw;
50
51         if (!curr_gateway_tmp)
52                 return NULL;
53
54         return curr_gateway_tmp->orig_node;
55 }
56
57 void gw_deselect(struct bat_priv *bat_priv)
58 {
59         struct gw_node *gw_node = bat_priv->curr_gw;
60
61         bat_priv->curr_gw = NULL;
62
63         if (gw_node)
64                 kref_put(&gw_node->refcount, gw_node_free_ref);
65 }
66
67 static struct gw_node *gw_select(struct bat_priv *bat_priv,
68                           struct gw_node *new_gw_node)
69 {
70         struct gw_node *curr_gw_node = bat_priv->curr_gw;
71
72         if (new_gw_node)
73                 kref_get(&new_gw_node->refcount);
74
75         bat_priv->curr_gw = new_gw_node;
76         return curr_gw_node;
77 }
78
79 void gw_election(struct bat_priv *bat_priv)
80 {
81         struct hlist_node *node;
82         struct gw_node *gw_node, *curr_gw_tmp = NULL, *old_gw_node = NULL;
83         uint8_t max_tq = 0;
84         uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
85         int down, up;
86
87         /**
88          * The batman daemon checks here if we already passed a full originator
89          * cycle in order to make sure we don't choose the first gateway we
90          * hear about. This check is based on the daemon's uptime which we
91          * don't have.
92          **/
93         if (atomic_read(&bat_priv->gw_mode) != GW_MODE_CLIENT)
94                 return;
95
96         if (bat_priv->curr_gw)
97                 return;
98
99         rcu_read_lock();
100         if (hlist_empty(&bat_priv->gw_list)) {
101                 rcu_read_unlock();
102
103                 if (bat_priv->curr_gw) {
104                         bat_dbg(DBG_BATMAN, bat_priv,
105                                 "Removing selected gateway - "
106                                 "no gateway in range\n");
107                         gw_deselect(bat_priv);
108                 }
109
110                 return;
111         }
112
113         hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
114                 if (!gw_node->orig_node->router)
115                         continue;
116
117                 if (gw_node->deleted)
118                         continue;
119
120                 switch (atomic_read(&bat_priv->gw_sel_class)) {
121                 case 1: /* fast connection */
122                         gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags,
123                                              &down, &up);
124
125                         tmp_gw_factor = (gw_node->orig_node->router->tq_avg *
126                                          gw_node->orig_node->router->tq_avg *
127                                          down * 100 * 100) /
128                                          (TQ_LOCAL_WINDOW_SIZE *
129                                          TQ_LOCAL_WINDOW_SIZE * 64);
130
131                         if ((tmp_gw_factor > max_gw_factor) ||
132                             ((tmp_gw_factor == max_gw_factor) &&
133                              (gw_node->orig_node->router->tq_avg > max_tq)))
134                                 curr_gw_tmp = gw_node;
135                         break;
136
137                 default: /**
138                           * 2:  stable connection (use best statistic)
139                           * 3:  fast-switch (use best statistic but change as
140                           *     soon as a better gateway appears)
141                           * XX: late-switch (use best statistic but change as
142                           *     soon as a better gateway appears which has
143                           *     $routing_class more tq points)
144                           **/
145                         if (gw_node->orig_node->router->tq_avg > max_tq)
146                                 curr_gw_tmp = gw_node;
147                         break;
148                 }
149
150                 if (gw_node->orig_node->router->tq_avg > max_tq)
151                         max_tq = gw_node->orig_node->router->tq_avg;
152
153                 if (tmp_gw_factor > max_gw_factor)
154                         max_gw_factor = tmp_gw_factor;
155         }
156
157         if (bat_priv->curr_gw != curr_gw_tmp) {
158                 if ((bat_priv->curr_gw) && (!curr_gw_tmp))
159                         bat_dbg(DBG_BATMAN, bat_priv,
160                                 "Removing selected gateway - "
161                                 "no gateway in range\n");
162                 else if ((!bat_priv->curr_gw) && (curr_gw_tmp))
163                         bat_dbg(DBG_BATMAN, bat_priv,
164                                 "Adding route to gateway %pM "
165                                 "(gw_flags: %i, tq: %i)\n",
166                                 curr_gw_tmp->orig_node->orig,
167                                 curr_gw_tmp->orig_node->gw_flags,
168                                 curr_gw_tmp->orig_node->router->tq_avg);
169                 else
170                         bat_dbg(DBG_BATMAN, bat_priv,
171                                 "Changing route to gateway %pM "
172                                 "(gw_flags: %i, tq: %i)\n",
173                                 curr_gw_tmp->orig_node->orig,
174                                 curr_gw_tmp->orig_node->gw_flags,
175                                 curr_gw_tmp->orig_node->router->tq_avg);
176
177                 old_gw_node = gw_select(bat_priv, curr_gw_tmp);
178         }
179
180         rcu_read_unlock();
181
182         /* the kfree() has to be outside of the rcu lock */
183         if (old_gw_node)
184                 kref_put(&old_gw_node->refcount, gw_node_free_ref);
185 }
186
187 void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node)
188 {
189         struct gw_node *curr_gateway_tmp = bat_priv->curr_gw;
190         uint8_t gw_tq_avg, orig_tq_avg;
191
192         if (!curr_gateway_tmp)
193                 return;
194
195         if (!curr_gateway_tmp->orig_node)
196                 goto deselect;
197
198         if (!curr_gateway_tmp->orig_node->router)
199                 goto deselect;
200
201         /* this node already is the gateway */
202         if (curr_gateway_tmp->orig_node == orig_node)
203                 return;
204
205         if (!orig_node->router)
206                 return;
207
208         gw_tq_avg = curr_gateway_tmp->orig_node->router->tq_avg;
209         orig_tq_avg = orig_node->router->tq_avg;
210
211         /* the TQ value has to be better */
212         if (orig_tq_avg < gw_tq_avg)
213                 return;
214
215         /**
216          * if the routing class is greater than 3 the value tells us how much
217          * greater the TQ value of the new gateway must be
218          **/
219         if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
220             (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
221                 return;
222
223         bat_dbg(DBG_BATMAN, bat_priv,
224                 "Restarting gateway selection: better gateway found (tq curr: "
225                 "%i, tq new: %i)\n",
226                 gw_tq_avg, orig_tq_avg);
227
228 deselect:
229         gw_deselect(bat_priv);
230 }
231
232 static void gw_node_add(struct bat_priv *bat_priv,
233                         struct orig_node *orig_node, uint8_t new_gwflags)
234 {
235         struct gw_node *gw_node;
236         int down, up;
237
238         gw_node = kmalloc(sizeof(struct gw_node), GFP_ATOMIC);
239         if (!gw_node)
240                 return;
241
242         memset(gw_node, 0, sizeof(struct gw_node));
243         INIT_HLIST_NODE(&gw_node->list);
244         gw_node->orig_node = orig_node;
245         kref_init(&gw_node->refcount);
246
247         spin_lock_bh(&bat_priv->gw_list_lock);
248         hlist_add_head_rcu(&gw_node->list, &bat_priv->gw_list);
249         spin_unlock_bh(&bat_priv->gw_list_lock);
250
251         gw_bandwidth_to_kbit(new_gwflags, &down, &up);
252         bat_dbg(DBG_BATMAN, bat_priv,
253                 "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
254                 orig_node->orig, new_gwflags,
255                 (down > 2048 ? down / 1024 : down),
256                 (down > 2048 ? "MBit" : "KBit"),
257                 (up > 2048 ? up / 1024 : up),
258                 (up > 2048 ? "MBit" : "KBit"));
259 }
260
261 void gw_node_update(struct bat_priv *bat_priv,
262                     struct orig_node *orig_node, uint8_t new_gwflags)
263 {
264         struct hlist_node *node;
265         struct gw_node *gw_node;
266
267         rcu_read_lock();
268         hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
269                 if (gw_node->orig_node != orig_node)
270                         continue;
271
272                 bat_dbg(DBG_BATMAN, bat_priv,
273                         "Gateway class of originator %pM changed from "
274                         "%i to %i\n",
275                         orig_node->orig, gw_node->orig_node->gw_flags,
276                         new_gwflags);
277
278                 gw_node->deleted = 0;
279
280                 if (new_gwflags == 0) {
281                         gw_node->deleted = jiffies;
282                         bat_dbg(DBG_BATMAN, bat_priv,
283                                 "Gateway %pM removed from gateway list\n",
284                                 orig_node->orig);
285
286                         if (gw_node == bat_priv->curr_gw) {
287                                 rcu_read_unlock();
288                                 gw_deselect(bat_priv);
289                                 return;
290                         }
291                 }
292
293                 rcu_read_unlock();
294                 return;
295         }
296         rcu_read_unlock();
297
298         if (new_gwflags == 0)
299                 return;
300
301         gw_node_add(bat_priv, orig_node, new_gwflags);
302 }
303
304 void gw_node_delete(struct bat_priv *bat_priv, struct orig_node *orig_node)
305 {
306         return gw_node_update(bat_priv, orig_node, 0);
307 }
308
309 void gw_node_purge(struct bat_priv *bat_priv)
310 {
311         struct gw_node *gw_node;
312         struct hlist_node *node, *node_tmp;
313         unsigned long timeout = 2 * PURGE_TIMEOUT * HZ;
314
315         spin_lock_bh(&bat_priv->gw_list_lock);
316
317         hlist_for_each_entry_safe(gw_node, node, node_tmp,
318                                   &bat_priv->gw_list, list) {
319                 if (((!gw_node->deleted) ||
320                      (time_before(jiffies, gw_node->deleted + timeout))) &&
321                     atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE)
322                         continue;
323
324                 if (bat_priv->curr_gw == gw_node)
325                         gw_deselect(bat_priv);
326
327                 hlist_del_rcu(&gw_node->list);
328                 call_rcu(&gw_node->rcu, gw_node_free_rcu);
329         }
330
331
332         spin_unlock_bh(&bat_priv->gw_list_lock);
333 }
334
335 static int _write_buffer_text(struct bat_priv *bat_priv,
336                               struct seq_file *seq, struct gw_node *gw_node)
337 {
338         int down, up;
339
340         gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
341
342         return seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
343                        (bat_priv->curr_gw == gw_node ? "=>" : "  "),
344                        gw_node->orig_node->orig,
345                        gw_node->orig_node->router->tq_avg,
346                        gw_node->orig_node->router->addr,
347                        gw_node->orig_node->router->if_incoming->net_dev->name,
348                        gw_node->orig_node->gw_flags,
349                        (down > 2048 ? down / 1024 : down),
350                        (down > 2048 ? "MBit" : "KBit"),
351                        (up > 2048 ? up / 1024 : up),
352                        (up > 2048 ? "MBit" : "KBit"));
353 }
354
355 int gw_client_seq_print_text(struct seq_file *seq, void *offset)
356 {
357         struct net_device *net_dev = (struct net_device *)seq->private;
358         struct bat_priv *bat_priv = netdev_priv(net_dev);
359         struct gw_node *gw_node;
360         struct hlist_node *node;
361         int gw_count = 0;
362
363         if (!bat_priv->primary_if) {
364
365                 return seq_printf(seq, "BATMAN mesh %s disabled - please "
366                                   "specify interfaces to enable it\n",
367                                   net_dev->name);
368         }
369
370         if (bat_priv->primary_if->if_status != IF_ACTIVE) {
371
372                 return seq_printf(seq, "BATMAN mesh %s disabled - "
373                                        "primary interface not active\n",
374                                        net_dev->name);
375         }
376
377         seq_printf(seq, "      %-12s (%s/%i) %17s [%10s]: gw_class ... "
378                    "[B.A.T.M.A.N. adv %s%s, MainIF/MAC: %s/%pM (%s)]\n",
379                    "Gateway", "#", TQ_MAX_VALUE, "Nexthop",
380                    "outgoingIF", SOURCE_VERSION, REVISION_VERSION_STR,
381                    bat_priv->primary_if->net_dev->name,
382                    bat_priv->primary_if->net_dev->dev_addr, net_dev->name);
383
384         rcu_read_lock();
385         hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
386                 if (gw_node->deleted)
387                         continue;
388
389                 if (!gw_node->orig_node->router)
390                         continue;
391
392                 _write_buffer_text(bat_priv, seq, gw_node);
393                 gw_count++;
394         }
395         rcu_read_unlock();
396
397         if (gw_count == 0)
398                 seq_printf(seq, "No gateways in range ...\n");
399
400         return 0;
401 }
402
403 int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb)
404 {
405         struct ethhdr *ethhdr;
406         struct iphdr *iphdr;
407         struct ipv6hdr *ipv6hdr;
408         struct udphdr *udphdr;
409         unsigned int header_len = 0;
410
411         if (atomic_read(&bat_priv->gw_mode) == GW_MODE_OFF)
412                 return 0;
413
414         /* check for ethernet header */
415         if (!pskb_may_pull(skb, header_len + ETH_HLEN))
416                 return 0;
417         ethhdr = (struct ethhdr *)skb->data;
418         header_len += ETH_HLEN;
419
420         /* check for initial vlan header */
421         if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
422                 if (!pskb_may_pull(skb, header_len + VLAN_HLEN))
423                         return 0;
424                 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
425                 header_len += VLAN_HLEN;
426         }
427
428         /* check for ip header */
429         switch (ntohs(ethhdr->h_proto)) {
430         case ETH_P_IP:
431                 if (!pskb_may_pull(skb, header_len + sizeof(struct iphdr)))
432                         return 0;
433                 iphdr = (struct iphdr *)(skb->data + header_len);
434                 header_len += iphdr->ihl * 4;
435
436                 /* check for udp header */
437                 if (iphdr->protocol != IPPROTO_UDP)
438                         return 0;
439
440                 break;
441         case ETH_P_IPV6:
442                 if (!pskb_may_pull(skb, header_len + sizeof(struct ipv6hdr)))
443                         return 0;
444                 ipv6hdr = (struct ipv6hdr *)(skb->data + header_len);
445                 header_len += sizeof(struct ipv6hdr);
446
447                 /* check for udp header */
448                 if (ipv6hdr->nexthdr != IPPROTO_UDP)
449                         return 0;
450
451                 break;
452         default:
453                 return 0;
454         }
455
456         if (!pskb_may_pull(skb, header_len + sizeof(struct udphdr)))
457                 return 0;
458         udphdr = (struct udphdr *)(skb->data + header_len);
459         header_len += sizeof(struct udphdr);
460
461         /* check for bootp port */
462         if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
463              (ntohs(udphdr->dest) != 67))
464                 return 0;
465
466         if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
467             (ntohs(udphdr->dest) != 547))
468                 return 0;
469
470         if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER)
471                 return -1;
472
473         if (!bat_priv->curr_gw)
474                 return 0;
475
476         return 1;
477 }