net: Add batman-adv meshing protocol

B.A.T.M.A.N. (better approach to mobile ad-hoc networking) is a routing
protocol for multi-hop ad-hoc mesh networks. The networks may be wired or
wireless. See http://www.open-mesh.org/ for more information and user space
tools.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 477 insertions, 0 deletions

diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
new file mode 100644
index 0000000..0065ffb
--- /dev/null
+++ b/net/batman-adv/gateway_client.c
@@ -0,0 +1,477 @@
+/*
+ * Copyright (C) 2009-2010 B.A.T.M.A.N. contributors:
+ *
+ * Marek Lindner
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ *
+ */
+
+#include "main.h"
+#include "gateway_client.h"
+#include "gateway_common.h"
+#include "hard-interface.h"
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/udp.h>
+#include <linux/if_vlan.h>
+
+static void gw_node_free_ref(struct kref *refcount)
+{
+	struct gw_node *gw_node;
+
+	gw_node = container_of(refcount, struct gw_node, refcount);
+	kfree(gw_node);
+}
+
+static void gw_node_free_rcu(struct rcu_head *rcu)
+{
+	struct gw_node *gw_node;
+
+	gw_node = container_of(rcu, struct gw_node, rcu);
+	kref_put(&gw_node->refcount, gw_node_free_ref);
+}
+
+void *gw_get_selected(struct bat_priv *bat_priv)
+{
+	struct gw_node *curr_gateway_tmp = bat_priv->curr_gw;
+
+	if (!curr_gateway_tmp)
+		return NULL;
+
+	return curr_gateway_tmp->orig_node;
+}
+
+void gw_deselect(struct bat_priv *bat_priv)
+{
+	struct gw_node *gw_node = bat_priv->curr_gw;
+
+	bat_priv->curr_gw = NULL;
+
+	if (gw_node)
+		kref_put(&gw_node->refcount, gw_node_free_ref);
+}
+
+static struct gw_node *gw_select(struct bat_priv *bat_priv,
+			  struct gw_node *new_gw_node)
+{
+	struct gw_node *curr_gw_node = bat_priv->curr_gw;
+
+	if (new_gw_node)
+		kref_get(&new_gw_node->refcount);
+
+	bat_priv->curr_gw = new_gw_node;
+	return curr_gw_node;
+}
+
+void gw_election(struct bat_priv *bat_priv)
+{
+	struct hlist_node *node;
+	struct gw_node *gw_node, *curr_gw_tmp = NULL, *old_gw_node = NULL;
+	uint8_t max_tq = 0;
+	uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
+	int down, up;
+
+	/**
+	 * The batman daemon checks here if we already passed a full originator
+	 * cycle in order to make sure we don't choose the first gateway we
+	 * hear about. This check is based on the daemon's uptime which we
+	 * don't have.
+	 **/
+	if (atomic_read(&bat_priv->gw_mode) != GW_MODE_CLIENT)
+		return;
+
+	if (bat_priv->curr_gw)
+		return;
+
+	rcu_read_lock();
+	if (hlist_empty(&bat_priv->gw_list)) {
+		rcu_read_unlock();
+
+		if (bat_priv->curr_gw) {
+			bat_dbg(DBG_BATMAN, bat_priv,
+				"Removing selected gateway - "
+				"no gateway in range\n");
+			gw_deselect(bat_priv);
+		}
+
+		return;
+	}
+
+	hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
+		if (!gw_node->orig_node->router)
+			continue;
+
+		if (gw_node->deleted)
+			continue;
+
+		switch (atomic_read(&bat_priv->gw_sel_class)) {
+		case 1: /* fast connection */
+			gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags,
+					     &down, &up);
+
+			tmp_gw_factor = (gw_node->orig_node->router->tq_avg *
+					 gw_node->orig_node->router->tq_avg *
+					 down * 100 * 100) /
+					 (TQ_LOCAL_WINDOW_SIZE *
+					 TQ_LOCAL_WINDOW_SIZE * 64);
+
+			if ((tmp_gw_factor > max_gw_factor) ||
+			    ((tmp_gw_factor == max_gw_factor) &&
+			     (gw_node->orig_node->router->tq_avg > max_tq)))
+				curr_gw_tmp = gw_node;
+			break;
+
+		default: /**
+			  * 2:  stable connection (use best statistic)
+			  * 3:  fast-switch (use best statistic but change as
+			  *     soon as a better gateway appears)
+			  * XX: late-switch (use best statistic but change as
+			  *     soon as a better gateway appears which has
+			  *     $routing_class more tq points)
+			  **/
+			if (gw_node->orig_node->router->tq_avg > max_tq)
+				curr_gw_tmp = gw_node;
+			break;
+		}
+
+		if (gw_node->orig_node->router->tq_avg > max_tq)
+			max_tq = gw_node->orig_node->router->tq_avg;
+
+		if (tmp_gw_factor > max_gw_factor)
+			max_gw_factor = tmp_gw_factor;
+	}
+
+	if (bat_priv->curr_gw != curr_gw_tmp) {
+		if ((bat_priv->curr_gw) && (!curr_gw_tmp))
+			bat_dbg(DBG_BATMAN, bat_priv,
+				"Removing selected gateway - "
+				"no gateway in range\n");
+		else if ((!bat_priv->curr_gw) && (curr_gw_tmp))
+			bat_dbg(DBG_BATMAN, bat_priv,
+				"Adding route to gateway %pM "
+				"(gw_flags: %i, tq: %i)\n",
+				curr_gw_tmp->orig_node->orig,
+				curr_gw_tmp->orig_node->gw_flags,
+				curr_gw_tmp->orig_node->router->tq_avg);
+		else
+			bat_dbg(DBG_BATMAN, bat_priv,
+				"Changing route to gateway %pM "
+				"(gw_flags: %i, tq: %i)\n",
+				curr_gw_tmp->orig_node->orig,
+				curr_gw_tmp->orig_node->gw_flags,
+				curr_gw_tmp->orig_node->router->tq_avg);
+
+		old_gw_node = gw_select(bat_priv, curr_gw_tmp);
+	}
+
+	rcu_read_unlock();
+
+	/* the kfree() has to be outside of the rcu lock */
+	if (old_gw_node)
+		kref_put(&old_gw_node->refcount, gw_node_free_ref);
+}
+
+void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node)
+{
+	struct gw_node *curr_gateway_tmp = bat_priv->curr_gw;
+	uint8_t gw_tq_avg, orig_tq_avg;
+
+	if (!curr_gateway_tmp)
+		return;
+
+	if (!curr_gateway_tmp->orig_node)
+		goto deselect;
+
+	if (!curr_gateway_tmp->orig_node->router)
+		goto deselect;
+
+	/* this node already is the gateway */
+	if (curr_gateway_tmp->orig_node == orig_node)
+		return;
+
+	if (!orig_node->router)
+		return;
+
+	gw_tq_avg = curr_gateway_tmp->orig_node->router->tq_avg;
+	orig_tq_avg = orig_node->router->tq_avg;
+
+	/* the TQ value has to be better */
+	if (orig_tq_avg < gw_tq_avg)
+		return;
+
+	/**
+	 * if the routing class is greater than 3 the value tells us how much
+	 * greater the TQ value of the new gateway must be
+	 **/
+	if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
+	    (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
+		return;
+
+	bat_dbg(DBG_BATMAN, bat_priv,
+		"Restarting gateway selection: better gateway found (tq curr: "
+		"%i, tq new: %i)\n",
+		gw_tq_avg, orig_tq_avg);
+
+deselect:
+	gw_deselect(bat_priv);
+}
+
+static void gw_node_add(struct bat_priv *bat_priv,
+			struct orig_node *orig_node, uint8_t new_gwflags)
+{
+	struct gw_node *gw_node;
+	int down, up;
+
+	gw_node = kmalloc(sizeof(struct gw_node), GFP_ATOMIC);
+	if (!gw_node)
+		return;
+
+	memset(gw_node, 0, sizeof(struct gw_node));
+	INIT_HLIST_NODE(&gw_node->list);
+	gw_node->orig_node = orig_node;
+	kref_init(&gw_node->refcount);
+
+	spin_lock_bh(&bat_priv->gw_list_lock);
+	hlist_add_head_rcu(&gw_node->list, &bat_priv->gw_list);
+	spin_unlock_bh(&bat_priv->gw_list_lock);
+
+	gw_bandwidth_to_kbit(new_gwflags, &down, &up);
+	bat_dbg(DBG_BATMAN, bat_priv,
+		"Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
+		orig_node->orig, new_gwflags,
+		(down > 2048 ? down / 1024 : down),
+		(down > 2048 ? "MBit" : "KBit"),
+		(up > 2048 ? up / 1024 : up),
+		(up > 2048 ? "MBit" : "KBit"));
+}
+
+void gw_node_update(struct bat_priv *bat_priv,
+		    struct orig_node *orig_node, uint8_t new_gwflags)
+{
+	struct hlist_node *node;
+	struct gw_node *gw_node;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
+		if (gw_node->orig_node != orig_node)
+			continue;
+
+		bat_dbg(DBG_BATMAN, bat_priv,
+			"Gateway class of originator %pM changed from "
+			"%i to %i\n",
+			orig_node->orig, gw_node->orig_node->gw_flags,
+			new_gwflags);
+
+		gw_node->deleted = 0;
+
+		if (new_gwflags == 0) {
+			gw_node->deleted = jiffies;
+			bat_dbg(DBG_BATMAN, bat_priv,
+				"Gateway %pM removed from gateway list\n",
+				orig_node->orig);
+
+			if (gw_node == bat_priv->curr_gw) {
+				rcu_read_unlock();
+				gw_deselect(bat_priv);
+				return;
+			}
+		}
+
+		rcu_read_unlock();
+		return;
+	}
+	rcu_read_unlock();
+
+	if (new_gwflags == 0)
+		return;
+
+	gw_node_add(bat_priv, orig_node, new_gwflags);
+}
+
+void gw_node_delete(struct bat_priv *bat_priv, struct orig_node *orig_node)
+{
+	return gw_node_update(bat_priv, orig_node, 0);
+}
+
+void gw_node_purge(struct bat_priv *bat_priv)
+{
+	struct gw_node *gw_node;
+	struct hlist_node *node, *node_tmp;
+	unsigned long timeout = 2 * PURGE_TIMEOUT * HZ;
+
+	spin_lock_bh(&bat_priv->gw_list_lock);
+
+	hlist_for_each_entry_safe(gw_node, node, node_tmp,
+				  &bat_priv->gw_list, list) {
+		if (((!gw_node->deleted) ||
+		     (time_before(jiffies, gw_node->deleted + timeout))) &&
+		    atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE)
+			continue;
+
+		if (bat_priv->curr_gw == gw_node)
+			gw_deselect(bat_priv);
+
+		hlist_del_rcu(&gw_node->list);
+		call_rcu(&gw_node->rcu, gw_node_free_rcu);
+	}
+
+
+	spin_unlock_bh(&bat_priv->gw_list_lock);
+}
+
+static int _write_buffer_text(struct bat_priv *bat_priv,
+			      struct seq_file *seq, struct gw_node *gw_node)
+{
+	int down, up;
+
+	gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
+
+	return seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
+		       (bat_priv->curr_gw == gw_node ? "=>" : "  "),
+		       gw_node->orig_node->orig,
+		       gw_node->orig_node->router->tq_avg,
+		       gw_node->orig_node->router->addr,
+		       gw_node->orig_node->router->if_incoming->net_dev->name,
+		       gw_node->orig_node->gw_flags,
+		       (down > 2048 ? down / 1024 : down),
+		       (down > 2048 ? "MBit" : "KBit"),
+		       (up > 2048 ? up / 1024 : up),
+		       (up > 2048 ? "MBit" : "KBit"));
+}
+
+int gw_client_seq_print_text(struct seq_file *seq, void *offset)
+{
+	struct net_device *net_dev = (struct net_device *)seq->private;
+	struct bat_priv *bat_priv = netdev_priv(net_dev);
+	struct gw_node *gw_node;
+	struct hlist_node *node;
+	int gw_count = 0;
+
+	if (!bat_priv->primary_if) {
+
+		return seq_printf(seq, "BATMAN mesh %s disabled - please "
+				  "specify interfaces to enable it\n",
+				  net_dev->name);
+	}
+
+	if (bat_priv->primary_if->if_status != IF_ACTIVE) {
+
+		return seq_printf(seq, "BATMAN mesh %s disabled - "
+				       "primary interface not active\n",
+				       net_dev->name);
+	}
+
+	seq_printf(seq, "      %-12s (%s/%i) %17s [%10s]: gw_class ... "
+		   "[B.A.T.M.A.N. adv %s%s, MainIF/MAC: %s/%pM (%s)]\n",
+		   "Gateway", "#", TQ_MAX_VALUE, "Nexthop",
+		   "outgoingIF", SOURCE_VERSION, REVISION_VERSION_STR,
+		   bat_priv->primary_if->net_dev->name,
+		   bat_priv->primary_if->net_dev->dev_addr, net_dev->name);
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
+		if (gw_node->deleted)
+			continue;
+
+		if (!gw_node->orig_node->router)
+			continue;
+
+		_write_buffer_text(bat_priv, seq, gw_node);
+		gw_count++;
+	}
+	rcu_read_unlock();
+
+	if (gw_count == 0)
+		seq_printf(seq, "No gateways in range ...\n");
+
+	return 0;
+}
+
+int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb)
+{
+	struct ethhdr *ethhdr;
+	struct iphdr *iphdr;
+	struct ipv6hdr *ipv6hdr;
+	struct udphdr *udphdr;
+	unsigned int header_len = 0;
+
+	if (atomic_read(&bat_priv->gw_mode) == GW_MODE_OFF)
+		return 0;
+
+	/* check for ethernet header */
+	if (!pskb_may_pull(skb, header_len + ETH_HLEN))
+		return 0;
+	ethhdr = (struct ethhdr *)skb->data;
+	header_len += ETH_HLEN;
+
+	/* check for initial vlan header */
+	if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
+		if (!pskb_may_pull(skb, header_len + VLAN_HLEN))
+			return 0;
+		ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
+		header_len += VLAN_HLEN;
+	}
+
+	/* check for ip header */
+	switch (ntohs(ethhdr->h_proto)) {
+	case ETH_P_IP:
+		if (!pskb_may_pull(skb, header_len + sizeof(struct iphdr)))
+			return 0;
+		iphdr = (struct iphdr *)(skb->data + header_len);
+		header_len += iphdr->ihl * 4;
+
+		/* check for udp header */
+		if (iphdr->protocol != IPPROTO_UDP)
+			return 0;
+
+		break;
+	case ETH_P_IPV6:
+		if (!pskb_may_pull(skb, header_len + sizeof(struct ipv6hdr)))
+			return 0;
+		ipv6hdr = (struct ipv6hdr *)(skb->data + header_len);
+		header_len += sizeof(struct ipv6hdr);
+
+		/* check for udp header */
+		if (ipv6hdr->nexthdr != IPPROTO_UDP)
+			return 0;
+
+		break;
+	default:
+		return 0;
+	}
+
+	if (!pskb_may_pull(skb, header_len + sizeof(struct udphdr)))
+		return 0;
+	udphdr = (struct udphdr *)(skb->data + header_len);
+	header_len += sizeof(struct udphdr);
+
+	/* check for bootp port */
+	if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
+	     (ntohs(udphdr->dest) != 67))
+		return 0;
+
+	if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
+	    (ntohs(udphdr->dest) != 547))
+		return 0;
+
+	if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER)
+		return -1;
+
+	if (!bat_priv->curr_gw)
+		return 0;
+
+	return 1;
+}