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);
+}