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, 585 insertions, 0 deletions

diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
new file mode 100644
index 000000000000..b89b9f7709ae
--- /dev/null
+++ b/net/batman-adv/send.c
@@ -0,0 +1,585 @@
+/*
+ * Copyright (C) 2007-2010 B.A.T.M.A.N. contributors:
+ *
+ * Marek Lindner, Simon Wunderlich
+ *
+ * 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 "send.h"
+#include "routing.h"
+#include "translation-table.h"
+#include "soft-interface.h"
+#include "hard-interface.h"
+#include "types.h"
+#include "vis.h"
+#include "aggregation.h"
+#include "gateway_common.h"
+#include "originator.h"
+
+static void send_outstanding_bcast_packet(struct work_struct *work);
+
+/* apply hop penalty for a normal link */
+static uint8_t hop_penalty(const uint8_t tq, struct bat_priv *bat_priv)
+{
+	int hop_penalty = atomic_read(&bat_priv->hop_penalty);
+	return (tq * (TQ_MAX_VALUE - hop_penalty)) / (TQ_MAX_VALUE);
+}
+
+/* when do we schedule our own packet to be sent */
+static unsigned long own_send_time(struct bat_priv *bat_priv)
+{
+	return jiffies + msecs_to_jiffies(
+		   atomic_read(&bat_priv->orig_interval) -
+		   JITTER + (random32() % 2*JITTER));
+}
+
+/* when do we schedule a forwarded packet to be sent */
+static unsigned long forward_send_time(struct bat_priv *bat_priv)
+{
+	return jiffies + msecs_to_jiffies(random32() % (JITTER/2));
+}
+
+/* send out an already prepared packet to the given address via the
+ * specified batman interface */
+int send_skb_packet(struct sk_buff *skb,
+				struct batman_if *batman_if,
+				uint8_t *dst_addr)
+{
+	struct ethhdr *ethhdr;
+
+	if (batman_if->if_status != IF_ACTIVE)
+		goto send_skb_err;
+
+	if (unlikely(!batman_if->net_dev))
+		goto send_skb_err;
+
+	if (!(batman_if->net_dev->flags & IFF_UP)) {
+		pr_warning("Interface %s is not up - can't send packet via "
+			   "that interface!\n", batman_if->net_dev->name);
+		goto send_skb_err;
+	}
+
+	/* push to the ethernet header. */
+	if (my_skb_head_push(skb, sizeof(struct ethhdr)) < 0)
+		goto send_skb_err;
+
+	skb_reset_mac_header(skb);
+
+	ethhdr = (struct ethhdr *) skb_mac_header(skb);
+	memcpy(ethhdr->h_source, batman_if->net_dev->dev_addr, ETH_ALEN);
+	memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
+	ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
+
+	skb_set_network_header(skb, ETH_HLEN);
+	skb->priority = TC_PRIO_CONTROL;
+	skb->protocol = __constant_htons(ETH_P_BATMAN);
+
+	skb->dev = batman_if->net_dev;
+
+	/* dev_queue_xmit() returns a negative result on error.	 However on
+	 * congestion and traffic shaping, it drops and returns NET_XMIT_DROP
+	 * (which is > 0). This will not be treated as an error. */
+
+	return dev_queue_xmit(skb);
+send_skb_err:
+	kfree_skb(skb);
+	return NET_XMIT_DROP;
+}
+
+/* Send a packet to a given interface */
+static void send_packet_to_if(struct forw_packet *forw_packet,
+			      struct batman_if *batman_if)
+{
+	struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
+	char *fwd_str;
+	uint8_t packet_num;
+	int16_t buff_pos;
+	struct batman_packet *batman_packet;
+	struct sk_buff *skb;
+
+	if (batman_if->if_status != IF_ACTIVE)
+		return;
+
+	packet_num = 0;
+	buff_pos = 0;
+	batman_packet = (struct batman_packet *)forw_packet->skb->data;
+
+	/* adjust all flags and log packets */
+	while (aggregated_packet(buff_pos,
+				 forw_packet->packet_len,
+				 batman_packet->num_hna)) {
+
+		/* we might have aggregated direct link packets with an
+		 * ordinary base packet */
+		if ((forw_packet->direct_link_flags & (1 << packet_num)) &&
+		    (forw_packet->if_incoming == batman_if))
+			batman_packet->flags |= DIRECTLINK;
+		else
+			batman_packet->flags &= ~DIRECTLINK;
+
+		fwd_str = (packet_num > 0 ? "Forwarding" : (forw_packet->own ?
+							    "Sending own" :
+							    "Forwarding"));
+		bat_dbg(DBG_BATMAN, bat_priv,
+			"%s %spacket (originator %pM, seqno %d, TQ %d, TTL %d,"
+			" IDF %s) on interface %s [%pM]\n",
+			fwd_str, (packet_num > 0 ? "aggregated " : ""),
+			batman_packet->orig, ntohl(batman_packet->seqno),
+			batman_packet->tq, batman_packet->ttl,
+			(batman_packet->flags & DIRECTLINK ?
+			 "on" : "off"),
+			batman_if->net_dev->name, batman_if->net_dev->dev_addr);
+
+		buff_pos += sizeof(struct batman_packet) +
+			(batman_packet->num_hna * ETH_ALEN);
+		packet_num++;
+		batman_packet = (struct batman_packet *)
+			(forw_packet->skb->data + buff_pos);
+	}
+
+	/* create clone because function is called more than once */
+	skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
+	if (skb)
+		send_skb_packet(skb, batman_if, broadcast_addr);
+}
+
+/* send a batman packet */
+static void send_packet(struct forw_packet *forw_packet)
+{
+	struct batman_if *batman_if;
+	struct net_device *soft_iface;
+	struct bat_priv *bat_priv;
+	struct batman_packet *batman_packet =
+		(struct batman_packet *)(forw_packet->skb->data);
+	unsigned char directlink = (batman_packet->flags & DIRECTLINK ? 1 : 0);
+
+	if (!forw_packet->if_incoming) {
+		pr_err("Error - can't forward packet: incoming iface not "
+		       "specified\n");
+		return;
+	}
+
+	soft_iface = forw_packet->if_incoming->soft_iface;
+	bat_priv = netdev_priv(soft_iface);
+
+	if (forw_packet->if_incoming->if_status != IF_ACTIVE)
+		return;
+
+	/* multihomed peer assumed */
+	/* non-primary OGMs are only broadcasted on their interface */
+	if ((directlink && (batman_packet->ttl == 1)) ||
+	    (forw_packet->own && (forw_packet->if_incoming->if_num > 0))) {
+
+		/* FIXME: what about aggregated packets ? */
+		bat_dbg(DBG_BATMAN, bat_priv,
+			"%s packet (originator %pM, seqno %d, TTL %d) "
+			"on interface %s [%pM]\n",
+			(forw_packet->own ? "Sending own" : "Forwarding"),
+			batman_packet->orig, ntohl(batman_packet->seqno),
+			batman_packet->ttl,
+			forw_packet->if_incoming->net_dev->name,
+			forw_packet->if_incoming->net_dev->dev_addr);
+
+		/* skb is only used once and than forw_packet is free'd */
+		send_skb_packet(forw_packet->skb, forw_packet->if_incoming,
+				broadcast_addr);
+		forw_packet->skb = NULL;
+
+		return;
+	}
+
+	/* broadcast on every interface */
+	rcu_read_lock();
+	list_for_each_entry_rcu(batman_if, &if_list, list) {
+		if (batman_if->soft_iface != soft_iface)
+			continue;
+
+		send_packet_to_if(forw_packet, batman_if);
+	}
+	rcu_read_unlock();
+}
+
+static void rebuild_batman_packet(struct bat_priv *bat_priv,
+				  struct batman_if *batman_if)
+{
+	int new_len;
+	unsigned char *new_buff;
+	struct batman_packet *batman_packet;
+
+	new_len = sizeof(struct batman_packet) +
+			(bat_priv->num_local_hna * ETH_ALEN);
+	new_buff = kmalloc(new_len, GFP_ATOMIC);
+
+	/* keep old buffer if kmalloc should fail */
+	if (new_buff) {
+		memcpy(new_buff, batman_if->packet_buff,
+		       sizeof(struct batman_packet));
+		batman_packet = (struct batman_packet *)new_buff;
+
+		batman_packet->num_hna = hna_local_fill_buffer(bat_priv,
+				new_buff + sizeof(struct batman_packet),
+				new_len - sizeof(struct batman_packet));
+
+		kfree(batman_if->packet_buff);
+		batman_if->packet_buff = new_buff;
+		batman_if->packet_len = new_len;
+	}
+}
+
+void schedule_own_packet(struct batman_if *batman_if)
+{
+	struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
+	unsigned long send_time;
+	struct batman_packet *batman_packet;
+	int vis_server;
+
+	if ((batman_if->if_status == IF_NOT_IN_USE) ||
+	    (batman_if->if_status == IF_TO_BE_REMOVED))
+		return;
+
+	vis_server = atomic_read(&bat_priv->vis_mode);
+
+	/**
+	 * the interface gets activated here to avoid race conditions between
+	 * the moment of activating the interface in
+	 * hardif_activate_interface() where the originator mac is set and
+	 * outdated packets (especially uninitialized mac addresses) in the
+	 * packet queue
+	 */
+	if (batman_if->if_status == IF_TO_BE_ACTIVATED)
+		batman_if->if_status = IF_ACTIVE;
+
+	/* if local hna has changed and interface is a primary interface */
+	if ((atomic_read(&bat_priv->hna_local_changed)) &&
+	    (batman_if == bat_priv->primary_if))
+		rebuild_batman_packet(bat_priv, batman_if);
+
+	/**
+	 * NOTE: packet_buff might just have been re-allocated in
+	 * rebuild_batman_packet()
+	 */
+	batman_packet = (struct batman_packet *)batman_if->packet_buff;
+
+	/* change sequence number to network order */
+	batman_packet->seqno =
+		htonl((uint32_t)atomic_read(&batman_if->seqno));
+
+	if (vis_server == VIS_TYPE_SERVER_SYNC)
+		batman_packet->flags |= VIS_SERVER;
+	else
+		batman_packet->flags &= ~VIS_SERVER;
+
+	if ((batman_if == bat_priv->primary_if) &&
+	    (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER))
+		batman_packet->gw_flags =
+				(uint8_t)atomic_read(&bat_priv->gw_bandwidth);
+	else
+		batman_packet->gw_flags = 0;
+
+	atomic_inc(&batman_if->seqno);
+
+	slide_own_bcast_window(batman_if);
+	send_time = own_send_time(bat_priv);
+	add_bat_packet_to_list(bat_priv,
+			       batman_if->packet_buff,
+			       batman_if->packet_len,
+			       batman_if, 1, send_time);
+}
+
+void schedule_forward_packet(struct orig_node *orig_node,
+			     struct ethhdr *ethhdr,
+			     struct batman_packet *batman_packet,
+			     uint8_t directlink, int hna_buff_len,
+			     struct batman_if *if_incoming)
+{
+	struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
+	unsigned char in_tq, in_ttl, tq_avg = 0;
+	unsigned long send_time;
+
+	if (batman_packet->ttl <= 1) {
+		bat_dbg(DBG_BATMAN, bat_priv, "ttl exceeded\n");
+		return;
+	}
+
+	in_tq = batman_packet->tq;
+	in_ttl = batman_packet->ttl;
+
+	batman_packet->ttl--;
+	memcpy(batman_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
+
+	/* rebroadcast tq of our best ranking neighbor to ensure the rebroadcast
+	 * of our best tq value */
+	if ((orig_node->router) && (orig_node->router->tq_avg != 0)) {
+
+		/* rebroadcast ogm of best ranking neighbor as is */
+		if (!compare_orig(orig_node->router->addr, ethhdr->h_source)) {
+			batman_packet->tq = orig_node->router->tq_avg;
+
+			if (orig_node->router->last_ttl)
+				batman_packet->ttl = orig_node->router->last_ttl
+							- 1;
+		}
+
+		tq_avg = orig_node->router->tq_avg;
+	}
+
+	/* apply hop penalty */
+	batman_packet->tq = hop_penalty(batman_packet->tq, bat_priv);
+
+	bat_dbg(DBG_BATMAN, bat_priv,
+		"Forwarding packet: tq_orig: %i, tq_avg: %i, "
+		"tq_forw: %i, ttl_orig: %i, ttl_forw: %i\n",
+		in_tq, tq_avg, batman_packet->tq, in_ttl - 1,
+		batman_packet->ttl);
+
+	batman_packet->seqno = htonl(batman_packet->seqno);
+
+	/* switch of primaries first hop flag when forwarding */
+	batman_packet->flags &= ~PRIMARIES_FIRST_HOP;
+	if (directlink)
+		batman_packet->flags |= DIRECTLINK;
+	else
+		batman_packet->flags &= ~DIRECTLINK;
+
+	send_time = forward_send_time(bat_priv);
+	add_bat_packet_to_list(bat_priv,
+			       (unsigned char *)batman_packet,
+			       sizeof(struct batman_packet) + hna_buff_len,
+			       if_incoming, 0, send_time);
+}
+
+static void forw_packet_free(struct forw_packet *forw_packet)
+{
+	if (forw_packet->skb)
+		kfree_skb(forw_packet->skb);
+	kfree(forw_packet);
+}
+
+static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
+				      struct forw_packet *forw_packet,
+				      unsigned long send_time)
+{
+	INIT_HLIST_NODE(&forw_packet->list);
+
+	/* add new packet to packet list */
+	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
+	hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
+	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
+
+	/* start timer for this packet */
+	INIT_DELAYED_WORK(&forw_packet->delayed_work,
+			  send_outstanding_bcast_packet);
+	queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
+			   send_time);
+}
+
+#define atomic_dec_not_zero(v)          atomic_add_unless((v), -1, 0)
+/* add a broadcast packet to the queue and setup timers. broadcast packets
+ * are sent multiple times to increase probability for beeing received.
+ *
+ * This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
+ * errors.
+ *
+ * The skb is not consumed, so the caller should make sure that the
+ * skb is freed. */
+int add_bcast_packet_to_list(struct bat_priv *bat_priv, struct sk_buff *skb)
+{
+	struct forw_packet *forw_packet;
+	struct bcast_packet *bcast_packet;
+
+	if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
+		bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
+		goto out;
+	}
+
+	if (!bat_priv->primary_if)
+		goto out;
+
+	forw_packet = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC);
+
+	if (!forw_packet)
+		goto out_and_inc;
+
+	skb = skb_copy(skb, GFP_ATOMIC);
+	if (!skb)
+		goto packet_free;
+
+	/* as we have a copy now, it is safe to decrease the TTL */
+	bcast_packet = (struct bcast_packet *)skb->data;
+	bcast_packet->ttl--;
+
+	skb_reset_mac_header(skb);
+
+	forw_packet->skb = skb;
+	forw_packet->if_incoming = bat_priv->primary_if;
+
+	/* how often did we send the bcast packet ? */
+	forw_packet->num_packets = 0;
+
+	_add_bcast_packet_to_list(bat_priv, forw_packet, 1);
+	return NETDEV_TX_OK;
+
+packet_free:
+	kfree(forw_packet);
+out_and_inc:
+	atomic_inc(&bat_priv->bcast_queue_left);
+out:
+	return NETDEV_TX_BUSY;
+}
+
+static void send_outstanding_bcast_packet(struct work_struct *work)
+{
+	struct batman_if *batman_if;
+	struct delayed_work *delayed_work =
+		container_of(work, struct delayed_work, work);
+	struct forw_packet *forw_packet =
+		container_of(delayed_work, struct forw_packet, delayed_work);
+	struct sk_buff *skb1;
+	struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
+	struct bat_priv *bat_priv = netdev_priv(soft_iface);
+
+	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
+	hlist_del(&forw_packet->list);
+	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
+
+	if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
+		goto out;
+
+	/* rebroadcast packet */
+	rcu_read_lock();
+	list_for_each_entry_rcu(batman_if, &if_list, list) {
+		if (batman_if->soft_iface != soft_iface)
+			continue;
+
+		/* send a copy of the saved skb */
+		skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
+		if (skb1)
+			send_skb_packet(skb1, batman_if, broadcast_addr);
+	}
+	rcu_read_unlock();
+
+	forw_packet->num_packets++;
+
+	/* if we still have some more bcasts to send */
+	if (forw_packet->num_packets < 3) {
+		_add_bcast_packet_to_list(bat_priv, forw_packet,
+					  ((5 * HZ) / 1000));
+		return;
+	}
+
+out:
+	forw_packet_free(forw_packet);
+	atomic_inc(&bat_priv->bcast_queue_left);
+}
+
+void send_outstanding_bat_packet(struct work_struct *work)
+{
+	struct delayed_work *delayed_work =
+		container_of(work, struct delayed_work, work);
+	struct forw_packet *forw_packet =
+		container_of(delayed_work, struct forw_packet, delayed_work);
+	struct bat_priv *bat_priv;
+
+	bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
+	spin_lock_bh(&bat_priv->forw_bat_list_lock);
+	hlist_del(&forw_packet->list);
+	spin_unlock_bh(&bat_priv->forw_bat_list_lock);
+
+	if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
+		goto out;
+
+	send_packet(forw_packet);
+
+	/**
+	 * we have to have at least one packet in the queue
+	 * to determine the queues wake up time unless we are
+	 * shutting down
+	 */
+	if (forw_packet->own)
+		schedule_own_packet(forw_packet->if_incoming);
+
+out:
+	/* don't count own packet */
+	if (!forw_packet->own)
+		atomic_inc(&bat_priv->batman_queue_left);
+
+	forw_packet_free(forw_packet);
+}
+
+void purge_outstanding_packets(struct bat_priv *bat_priv,
+			       struct batman_if *batman_if)
+{
+	struct forw_packet *forw_packet;
+	struct hlist_node *tmp_node, *safe_tmp_node;
+
+	if (batman_if)
+		bat_dbg(DBG_BATMAN, bat_priv,
+			"purge_outstanding_packets(): %s\n",
+			batman_if->net_dev->name);
+	else
+		bat_dbg(DBG_BATMAN, bat_priv,
+			"purge_outstanding_packets()\n");
+
+	/* free bcast list */
+	spin_lock_bh(&bat_priv->forw_bcast_list_lock);
+	hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
+				  &bat_priv->forw_bcast_list, list) {
+
+		/**
+		 * if purge_outstanding_packets() was called with an argmument
+		 * we delete only packets belonging to the given interface
+		 */
+		if ((batman_if) &&
+		    (forw_packet->if_incoming != batman_if))
+			continue;
+
+		spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
+
+		/**
+		 * send_outstanding_bcast_packet() will lock the list to
+		 * delete the item from the list
+		 */
+		cancel_delayed_work_sync(&forw_packet->delayed_work);
+		spin_lock_bh(&bat_priv->forw_bcast_list_lock);
+	}
+	spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
+
+	/* free batman packet list */
+	spin_lock_bh(&bat_priv->forw_bat_list_lock);
+	hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
+				  &bat_priv->forw_bat_list, list) {
+
+		/**
+		 * if purge_outstanding_packets() was called with an argmument
+		 * we delete only packets belonging to the given interface
+		 */
+		if ((batman_if) &&
+		    (forw_packet->if_incoming != batman_if))
+			continue;
+
+		spin_unlock_bh(&bat_priv->forw_bat_list_lock);
+
+		/**
+		 * send_outstanding_bat_packet() will lock the list to
+		 * delete the item from the list
+		 */
+		cancel_delayed_work_sync(&forw_packet->delayed_work);
+		spin_lock_bh(&bat_priv->forw_bat_list_lock);
+	}
+	spin_unlock_bh(&bat_priv->forw_bat_list_lock);
+}