2 * Copyright (C) 2009-2011 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"
30 #include <linux/ipv6.h>
31 #include <linux/udp.h>
32 #include <linux/if_vlan.h>
34 /* This is the offset of the options field in a dhcp packet starting at
35 * the beginning of the dhcp header */
36 #define DHCP_OPTIONS_OFFSET 240
37 #define DHCP_REQUEST 3
39 static void gw_node_free_ref(struct gw_node *gw_node)
41 if (atomic_dec_and_test(&gw_node->refcount))
42 kfree_rcu(gw_node, rcu);
45 static struct gw_node *gw_get_selected_gw_node(struct bat_priv *bat_priv)
47 struct gw_node *gw_node;
50 gw_node = rcu_dereference(bat_priv->curr_gw);
54 if (!atomic_inc_not_zero(&gw_node->refcount))
62 struct orig_node *gw_get_selected_orig(struct bat_priv *bat_priv)
64 struct gw_node *gw_node;
65 struct orig_node *orig_node = NULL;
67 gw_node = gw_get_selected_gw_node(bat_priv);
72 orig_node = gw_node->orig_node;
76 if (!atomic_inc_not_zero(&orig_node->refcount))
83 gw_node_free_ref(gw_node);
87 static void gw_select(struct bat_priv *bat_priv, struct gw_node *new_gw_node)
89 struct gw_node *curr_gw_node;
91 spin_lock_bh(&bat_priv->gw_list_lock);
93 if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
96 curr_gw_node = rcu_dereference_protected(bat_priv->curr_gw, 1);
97 rcu_assign_pointer(bat_priv->curr_gw, new_gw_node);
100 gw_node_free_ref(curr_gw_node);
102 spin_unlock_bh(&bat_priv->gw_list_lock);
105 void gw_deselect(struct bat_priv *bat_priv)
107 atomic_set(&bat_priv->gw_reselect, 1);
110 static struct gw_node *gw_get_best_gw_node(struct bat_priv *bat_priv)
112 struct neigh_node *router;
113 struct hlist_node *node;
114 struct gw_node *gw_node, *curr_gw = NULL;
115 uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
120 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
121 if (gw_node->deleted)
124 router = orig_node_get_router(gw_node->orig_node);
128 if (!atomic_inc_not_zero(&gw_node->refcount))
131 switch (atomic_read(&bat_priv->gw_sel_class)) {
132 case 1: /* fast connection */
133 gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags,
136 tmp_gw_factor = (router->tq_avg * router->tq_avg *
138 (TQ_LOCAL_WINDOW_SIZE *
139 TQ_LOCAL_WINDOW_SIZE * 64);
141 if ((tmp_gw_factor > max_gw_factor) ||
142 ((tmp_gw_factor == max_gw_factor) &&
143 (router->tq_avg > max_tq))) {
145 gw_node_free_ref(curr_gw);
147 atomic_inc(&curr_gw->refcount);
152 * 2: stable connection (use best statistic)
153 * 3: fast-switch (use best statistic but change as
154 * soon as a better gateway appears)
155 * XX: late-switch (use best statistic but change as
156 * soon as a better gateway appears which has
157 * $routing_class more tq points)
159 if (router->tq_avg > max_tq) {
161 gw_node_free_ref(curr_gw);
163 atomic_inc(&curr_gw->refcount);
168 if (router->tq_avg > max_tq)
169 max_tq = router->tq_avg;
171 if (tmp_gw_factor > max_gw_factor)
172 max_gw_factor = tmp_gw_factor;
174 gw_node_free_ref(gw_node);
177 neigh_node_free_ref(router);
184 void gw_election(struct bat_priv *bat_priv)
186 struct gw_node *curr_gw = NULL, *next_gw = NULL;
187 struct neigh_node *router = NULL;
188 char gw_addr[18] = { '\0' };
191 * The batman daemon checks here if we already passed a full originator
192 * cycle in order to make sure we don't choose the first gateway we
193 * hear about. This check is based on the daemon's uptime which we
196 if (atomic_read(&bat_priv->gw_mode) != GW_MODE_CLIENT)
199 if (!atomic_dec_not_zero(&bat_priv->gw_reselect))
202 curr_gw = gw_get_selected_gw_node(bat_priv);
204 next_gw = gw_get_best_gw_node(bat_priv);
206 if (curr_gw == next_gw)
210 sprintf(gw_addr, "%pM", next_gw->orig_node->orig);
212 router = orig_node_get_router(next_gw->orig_node);
214 gw_deselect(bat_priv);
219 if ((curr_gw) && (!next_gw)) {
220 bat_dbg(DBG_BATMAN, bat_priv,
221 "Removing selected gateway - no gateway in range\n");
222 throw_uevent(bat_priv, UEV_GW, UEV_DEL, NULL);
223 } else if ((!curr_gw) && (next_gw)) {
224 bat_dbg(DBG_BATMAN, bat_priv,
225 "Adding route to gateway %pM (gw_flags: %i, tq: %i)\n",
226 next_gw->orig_node->orig,
227 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 "
233 "(gw_flags: %i, tq: %i)\n",
234 next_gw->orig_node->orig,
235 next_gw->orig_node->gw_flags,
237 throw_uevent(bat_priv, UEV_GW, UEV_CHANGE, gw_addr);
240 gw_select(bat_priv, next_gw);
244 gw_node_free_ref(curr_gw);
246 gw_node_free_ref(next_gw);
248 neigh_node_free_ref(router);
251 void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node)
253 struct orig_node *curr_gw_orig;
254 struct neigh_node *router_gw = NULL, *router_orig = NULL;
255 uint8_t gw_tq_avg, orig_tq_avg;
257 curr_gw_orig = gw_get_selected_orig(bat_priv);
261 router_gw = orig_node_get_router(curr_gw_orig);
265 /* this node already is the gateway */
266 if (curr_gw_orig == orig_node)
269 router_orig = orig_node_get_router(orig_node);
273 gw_tq_avg = router_gw->tq_avg;
274 orig_tq_avg = router_orig->tq_avg;
276 /* the TQ value has to be better */
277 if (orig_tq_avg < gw_tq_avg)
281 * if the routing class is greater than 3 the value tells us how much
282 * greater the TQ value of the new gateway must be
284 if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
285 (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
288 bat_dbg(DBG_BATMAN, bat_priv,
289 "Restarting gateway selection: better gateway found (tq curr: "
291 gw_tq_avg, orig_tq_avg);
294 gw_deselect(bat_priv);
297 orig_node_free_ref(curr_gw_orig);
299 neigh_node_free_ref(router_gw);
301 neigh_node_free_ref(router_orig);
306 static void gw_node_add(struct bat_priv *bat_priv,
307 struct orig_node *orig_node, uint8_t new_gwflags)
309 struct gw_node *gw_node;
312 gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
316 INIT_HLIST_NODE(&gw_node->list);
317 gw_node->orig_node = orig_node;
318 atomic_set(&gw_node->refcount, 1);
320 spin_lock_bh(&bat_priv->gw_list_lock);
321 hlist_add_head_rcu(&gw_node->list, &bat_priv->gw_list);
322 spin_unlock_bh(&bat_priv->gw_list_lock);
324 gw_bandwidth_to_kbit(new_gwflags, &down, &up);
325 bat_dbg(DBG_BATMAN, bat_priv,
326 "Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
327 orig_node->orig, new_gwflags,
328 (down > 2048 ? down / 1024 : down),
329 (down > 2048 ? "MBit" : "KBit"),
330 (up > 2048 ? up / 1024 : up),
331 (up > 2048 ? "MBit" : "KBit"));
334 void gw_node_update(struct bat_priv *bat_priv,
335 struct orig_node *orig_node, uint8_t new_gwflags)
337 struct hlist_node *node;
338 struct gw_node *gw_node, *curr_gw;
341 * Note: We don't need a NULL check here, since curr_gw never gets
342 * dereferenced. If curr_gw is NULL we also should not exit as we may
343 * have this gateway in our list (duplication check!) even though we
344 * have no currently selected gateway.
346 curr_gw = gw_get_selected_gw_node(bat_priv);
349 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
350 if (gw_node->orig_node != orig_node)
353 bat_dbg(DBG_BATMAN, bat_priv,
354 "Gateway class of originator %pM changed from "
356 orig_node->orig, gw_node->orig_node->gw_flags,
359 gw_node->deleted = 0;
361 if (new_gwflags == NO_FLAGS) {
362 gw_node->deleted = jiffies;
363 bat_dbg(DBG_BATMAN, bat_priv,
364 "Gateway %pM removed from gateway list\n",
367 if (gw_node == curr_gw)
374 if (new_gwflags == NO_FLAGS)
377 gw_node_add(bat_priv, orig_node, new_gwflags);
381 gw_deselect(bat_priv);
386 gw_node_free_ref(curr_gw);
389 void gw_node_delete(struct bat_priv *bat_priv, struct orig_node *orig_node)
391 gw_node_update(bat_priv, orig_node, 0);
394 void gw_node_purge(struct bat_priv *bat_priv)
396 struct gw_node *gw_node, *curr_gw;
397 struct hlist_node *node, *node_tmp;
398 unsigned long timeout = 2 * PURGE_TIMEOUT * HZ;
401 curr_gw = gw_get_selected_gw_node(bat_priv);
403 spin_lock_bh(&bat_priv->gw_list_lock);
405 hlist_for_each_entry_safe(gw_node, node, node_tmp,
406 &bat_priv->gw_list, list) {
407 if (((!gw_node->deleted) ||
408 (time_before(jiffies, gw_node->deleted + timeout))) &&
409 atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE)
412 if (curr_gw == gw_node)
415 hlist_del_rcu(&gw_node->list);
416 gw_node_free_ref(gw_node);
419 spin_unlock_bh(&bat_priv->gw_list_lock);
421 /* gw_deselect() needs to acquire the gw_list_lock */
423 gw_deselect(bat_priv);
426 gw_node_free_ref(curr_gw);
430 * fails if orig_node has no router
432 static int _write_buffer_text(struct bat_priv *bat_priv, struct seq_file *seq,
433 const struct gw_node *gw_node)
435 struct gw_node *curr_gw;
436 struct neigh_node *router;
437 int down, up, ret = -1;
439 gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
441 router = orig_node_get_router(gw_node->orig_node);
445 curr_gw = gw_get_selected_gw_node(bat_priv);
447 ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
448 (curr_gw == gw_node ? "=>" : " "),
449 gw_node->orig_node->orig,
450 router->tq_avg, router->addr,
451 router->if_incoming->net_dev->name,
452 gw_node->orig_node->gw_flags,
453 (down > 2048 ? down / 1024 : down),
454 (down > 2048 ? "MBit" : "KBit"),
455 (up > 2048 ? up / 1024 : up),
456 (up > 2048 ? "MBit" : "KBit"));
458 neigh_node_free_ref(router);
460 gw_node_free_ref(curr_gw);
465 int gw_client_seq_print_text(struct seq_file *seq, void *offset)
467 struct net_device *net_dev = (struct net_device *)seq->private;
468 struct bat_priv *bat_priv = netdev_priv(net_dev);
469 struct hard_iface *primary_if;
470 struct gw_node *gw_node;
471 struct hlist_node *node;
472 int gw_count = 0, ret = 0;
474 primary_if = primary_if_get_selected(bat_priv);
476 ret = seq_printf(seq, "BATMAN mesh %s disabled - please "
477 "specify interfaces to enable it\n",
482 if (primary_if->if_status != IF_ACTIVE) {
483 ret = seq_printf(seq, "BATMAN mesh %s disabled - "
484 "primary interface not active\n",
489 seq_printf(seq, " %-12s (%s/%i) %17s [%10s]: gw_class ... "
490 "[B.A.T.M.A.N. adv %s, MainIF/MAC: %s/%pM (%s)]\n",
491 "Gateway", "#", TQ_MAX_VALUE, "Nexthop",
492 "outgoingIF", SOURCE_VERSION, primary_if->net_dev->name,
493 primary_if->net_dev->dev_addr, net_dev->name);
496 hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
497 if (gw_node->deleted)
500 /* fails if orig_node has no router */
501 if (_write_buffer_text(bat_priv, seq, gw_node) < 0)
509 seq_printf(seq, "No gateways in range ...\n");
513 hardif_free_ref(primary_if);
517 static bool is_type_dhcprequest(struct sk_buff *skb, int header_len)
523 if (skb_linearize(skb) < 0)
526 pkt_len = skb_headlen(skb);
528 if (pkt_len < header_len + DHCP_OPTIONS_OFFSET + 1)
531 p = skb->data + header_len + DHCP_OPTIONS_OFFSET;
532 pkt_len -= header_len + DHCP_OPTIONS_OFFSET + 1;
534 /* Access the dhcp option lists. Each entry is made up by:
535 * - octet 1: option type
536 * - octet 2: option data len (only if type != 255 and 0)
537 * - octet 3: option data */
538 while (*p != 255 && !ret) {
539 /* p now points to the first octet: option type */
541 /* type 53 is the message type option.
542 * Jump the len octet and go to the data octet */
547 /* check if the message type is what we need */
548 if (*p == DHCP_REQUEST)
551 } else if (*p == 0) {
552 /* option type 0 (padding), just go forward */
558 /* This is any other option. So we get the length... */
564 /* ...and then we jump over the data */
575 int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb,
576 struct orig_node *old_gw)
578 struct ethhdr *ethhdr;
580 struct ipv6hdr *ipv6hdr;
581 struct udphdr *udphdr;
582 struct gw_node *curr_gw;
583 struct neigh_node *neigh_curr = NULL, *neigh_old = NULL;
584 unsigned int header_len = 0;
587 if (atomic_read(&bat_priv->gw_mode) == GW_MODE_OFF)
590 /* check for ethernet header */
591 if (!pskb_may_pull(skb, header_len + ETH_HLEN))
593 ethhdr = (struct ethhdr *)skb->data;
594 header_len += ETH_HLEN;
596 /* check for initial vlan header */
597 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
598 if (!pskb_may_pull(skb, header_len + VLAN_HLEN))
600 ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
601 header_len += VLAN_HLEN;
604 /* check for ip header */
605 switch (ntohs(ethhdr->h_proto)) {
607 if (!pskb_may_pull(skb, header_len + sizeof(*iphdr)))
609 iphdr = (struct iphdr *)(skb->data + header_len);
610 header_len += iphdr->ihl * 4;
612 /* check for udp header */
613 if (iphdr->protocol != IPPROTO_UDP)
618 if (!pskb_may_pull(skb, header_len + sizeof(*ipv6hdr)))
620 ipv6hdr = (struct ipv6hdr *)(skb->data + header_len);
621 header_len += sizeof(*ipv6hdr);
623 /* check for udp header */
624 if (ipv6hdr->nexthdr != IPPROTO_UDP)
632 if (!pskb_may_pull(skb, header_len + sizeof(*udphdr)))
634 udphdr = (struct udphdr *)(skb->data + header_len);
635 header_len += sizeof(*udphdr);
637 /* check for bootp port */
638 if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
639 (ntohs(udphdr->dest) != 67))
642 if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
643 (ntohs(udphdr->dest) != 547))
646 if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER)
649 curr_gw = gw_get_selected_gw_node(bat_priv);
653 /* If old_gw != NULL then this packet is unicast.
654 * So, at this point we have to check the message type: if it is a
655 * DHCPREQUEST we have to decide whether to drop it or not */
656 if (old_gw && curr_gw->orig_node != old_gw) {
657 if (is_type_dhcprequest(skb, header_len)) {
658 /* If the dhcp packet has been sent to a different gw,
659 * we have to evaluate whether the old gw is still
661 neigh_curr = find_router(bat_priv, curr_gw->orig_node,
663 neigh_old = find_router(bat_priv, old_gw, NULL);
664 if (!neigh_curr || !neigh_old)
666 if (neigh_curr->tq_avg - neigh_old->tq_avg <
673 neigh_node_free_ref(neigh_old);
675 neigh_node_free_ref(neigh_curr);
677 gw_node_free_ref(curr_gw);