main.c

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/* Copyright (C) 2007-2012 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 "sysfs.h"
#include "debugfs.h"
#include "routing.h"
#include "send.h"
#include "originator.h"
#include "soft-interface.h"
#include "icmp_socket.h"
#include "translation-table.h"
#include "hard-interface.h"
#include "gateway_client.h"
#include "bridge_loop_avoidance.h"
#include "vis.h"
#include "hash.h"
#include "bat_algo.h"


/* List manipulations on hardif_list have to be rtnl_lock()'ed,
 * list traversals just rcu-locked
 */
struct list_head batadv_hardif_list;
static int (*batadv_rx_handler[256])(struct sk_buff *,
                     struct batadv_hard_iface *);
char batadv_routing_algo[20] = "BATMAN_IV";
static struct hlist_head batadv_algo_list;

unsigned char batadv_broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

struct workqueue_struct *batadv_event_workqueue;

static void batadv_recv_handler_init(void);

static int __init batadv_init(void)
{
    INIT_LIST_HEAD(&batadv_hardif_list);
    INIT_HLIST_HEAD(&batadv_algo_list);

    batadv_recv_handler_init();

    batadv_iv_init();

    batadv_event_workqueue = create_singlethread_workqueue("bat_events");

    if (!batadv_event_workqueue)
        return -ENOMEM;

    batadv_socket_init();
    batadv_debugfs_init();

    register_netdevice_notifier(&batadv_hard_if_notifier);

    pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
        BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);

    return 0;
}

static void __exit batadv_exit(void)
{
    batadv_debugfs_destroy();
    unregister_netdevice_notifier(&batadv_hard_if_notifier);
    batadv_hardif_remove_interfaces();

    flush_workqueue(batadv_event_workqueue);
    destroy_workqueue(batadv_event_workqueue);
    batadv_event_workqueue = NULL;

    rcu_barrier();
}

int batadv_mesh_init(struct net_device *soft_iface)
{
    struct batadv_priv *bat_priv = netdev_priv(soft_iface);
    int ret;

    spin_lock_init(&bat_priv->forw_bat_list_lock);
    spin_lock_init(&bat_priv->forw_bcast_list_lock);
    spin_lock_init(&bat_priv->tt.changes_list_lock);
    spin_lock_init(&bat_priv->tt.req_list_lock);
    spin_lock_init(&bat_priv->tt.roam_list_lock);
    spin_lock_init(&bat_priv->tt.last_changeset_lock);
    spin_lock_init(&bat_priv->gw.list_lock);
    spin_lock_init(&bat_priv->vis.hash_lock);
    spin_lock_init(&bat_priv->vis.list_lock);

    INIT_HLIST_HEAD(&bat_priv->forw_bat_list);
    INIT_HLIST_HEAD(&bat_priv->forw_bcast_list);
    INIT_HLIST_HEAD(&bat_priv->gw.list);
    INIT_LIST_HEAD(&bat_priv->tt.changes_list);
    INIT_LIST_HEAD(&bat_priv->tt.req_list);
    INIT_LIST_HEAD(&bat_priv->tt.roam_list);

    ret = batadv_originator_init(bat_priv);
    if (ret < 0)
        goto err;

    ret = batadv_tt_init(bat_priv);
    if (ret < 0)
        goto err;

    batadv_tt_local_add(soft_iface, soft_iface->dev_addr,
                BATADV_NULL_IFINDEX);

    ret = batadv_vis_init(bat_priv);
    if (ret < 0)
        goto err;

    ret = batadv_bla_init(bat_priv);
    if (ret < 0)
        goto err;

    atomic_set(&bat_priv->gw.reselect, 0);
    atomic_set(&bat_priv->mesh_state, BATADV_MESH_ACTIVE);

    return 0;

err:
    batadv_mesh_free(soft_iface);
    return ret;
}

void batadv_mesh_free(struct net_device *soft_iface)
{
    struct batadv_priv *bat_priv = netdev_priv(soft_iface);

    atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING);

    batadv_purge_outstanding_packets(bat_priv, NULL);

    batadv_vis_quit(bat_priv);

    batadv_gw_node_purge(bat_priv);
    batadv_originator_free(bat_priv);

    batadv_tt_free(bat_priv);

    batadv_bla_free(bat_priv);

    free_percpu(bat_priv->bat_counters);

    atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
}

void batadv_inc_module_count(void)
{
    try_module_get(THIS_MODULE);
}

void batadv_dec_module_count(void)
{
    module_put(THIS_MODULE);
}

int batadv_is_my_mac(const uint8_t *addr)
{
    const struct batadv_hard_iface *hard_iface;

    rcu_read_lock();
    list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
        if (hard_iface->if_status != BATADV_IF_ACTIVE)
            continue;

        if (batadv_compare_eth(hard_iface->net_dev->dev_addr, addr)) {
            rcu_read_unlock();
            return 1;
        }
    }
    rcu_read_unlock();
    return 0;
}

static int batadv_recv_unhandled_packet(struct sk_buff *skb,
                    struct batadv_hard_iface *recv_if)
{
    return NET_RX_DROP;
}

/* incoming packets with the batman ethertype received on any active hard
 * interface
 */
int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
               struct packet_type *ptype,
               struct net_device *orig_dev)
{
    struct batadv_priv *bat_priv;
    struct batadv_ogm_packet *batadv_ogm_packet;
    struct batadv_hard_iface *hard_iface;
    uint8_t idx;
    int ret;

    hard_iface = container_of(ptype, struct batadv_hard_iface,
                  batman_adv_ptype);
    skb = skb_share_check(skb, GFP_ATOMIC);

    /* skb was released by skb_share_check() */
    if (!skb)
        goto err_out;

    /* packet should hold at least type and version */
    if (unlikely(!pskb_may_pull(skb, 2)))
        goto err_free;

    /* expect a valid ethernet header here. */
    if (unlikely(skb->mac_len != ETH_HLEN || !skb_mac_header(skb)))
        goto err_free;

    if (!hard_iface->soft_iface)
        goto err_free;

    bat_priv = netdev_priv(hard_iface->soft_iface);

    if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
        goto err_free;

    /* discard frames on not active interfaces */
    if (hard_iface->if_status != BATADV_IF_ACTIVE)
        goto err_free;

    batadv_ogm_packet = (struct batadv_ogm_packet *)skb->data;

    if (batadv_ogm_packet->header.version != BATADV_COMPAT_VERSION) {
        batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
               "Drop packet: incompatible batman version (%i)\n",
               batadv_ogm_packet->header.version);
        goto err_free;
    }

    /* all receive handlers return whether they received or reused
     * the supplied skb. if not, we have to free the skb.
     */
    idx = batadv_ogm_packet->header.packet_type;
    ret = (*batadv_rx_handler[idx])(skb, hard_iface);

    if (ret == NET_RX_DROP)
        kfree_skb(skb);

    /* return NET_RX_SUCCESS in any case as we
     * most probably dropped the packet for
     * routing-logical reasons.
     */
    return NET_RX_SUCCESS;

err_free:
    kfree_skb(skb);
err_out:
    return NET_RX_DROP;
}

static void batadv_recv_handler_init(void)
{
    int i;

    for (i = 0; i < ARRAY_SIZE(batadv_rx_handler); i++)
        batadv_rx_handler[i] = batadv_recv_unhandled_packet;

    /* batman icmp packet */
    batadv_rx_handler[BATADV_ICMP] = batadv_recv_icmp_packet;
    /* unicast packet */
    batadv_rx_handler[BATADV_UNICAST] = batadv_recv_unicast_packet;
    /* fragmented unicast packet */
    batadv_rx_handler[BATADV_UNICAST_FRAG] = batadv_recv_ucast_frag_packet;
    /* broadcast packet */
    batadv_rx_handler[BATADV_BCAST] = batadv_recv_bcast_packet;
    /* vis packet */
    batadv_rx_handler[BATADV_VIS] = batadv_recv_vis_packet;
    /* Translation table query (request or response) */
    batadv_rx_handler[BATADV_TT_QUERY] = batadv_recv_tt_query;
    /* Roaming advertisement */
    batadv_rx_handler[BATADV_ROAM_ADV] = batadv_recv_roam_adv;
}

int
batadv_recv_handler_register(uint8_t packet_type,
                 int (*recv_handler)(struct sk_buff *,
                         struct batadv_hard_iface *))
{
    if (batadv_rx_handler[packet_type] != &batadv_recv_unhandled_packet)
        return -EBUSY;

    batadv_rx_handler[packet_type] = recv_handler;
    return 0;
}

void batadv_recv_handler_unregister(uint8_t packet_type)
{
    batadv_rx_handler[packet_type] = batadv_recv_unhandled_packet;
}

static struct batadv_algo_ops *batadv_algo_get(char *name)
{
    struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
    struct hlist_node *node;

    hlist_for_each_entry(bat_algo_ops_tmp, node, &batadv_algo_list, list) {
        if (strcmp(bat_algo_ops_tmp->name, name) != 0)
            continue;

        bat_algo_ops = bat_algo_ops_tmp;
        break;
    }

    return bat_algo_ops;
}

int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
{
    struct batadv_algo_ops *bat_algo_ops_tmp;
    int ret;

    bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
    if (bat_algo_ops_tmp) {
        pr_info("Trying to register already registered routing algorithm: %s\n",
            bat_algo_ops->name);
        ret = -EEXIST;
        goto out;
    }

    /* all algorithms must implement all ops (for now) */
    if (!bat_algo_ops->bat_iface_enable ||
        !bat_algo_ops->bat_iface_disable ||
        !bat_algo_ops->bat_iface_update_mac ||
        !bat_algo_ops->bat_primary_iface_set ||
        !bat_algo_ops->bat_ogm_schedule ||
        !bat_algo_ops->bat_ogm_emit) {
        pr_info("Routing algo '%s' does not implement required ops\n",
            bat_algo_ops->name);
        ret = -EINVAL;
        goto out;
    }

    INIT_HLIST_NODE(&bat_algo_ops->list);
    hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
    ret = 0;

out:
    return ret;
}

int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
{
    struct batadv_algo_ops *bat_algo_ops;
    int ret = -EINVAL;

    bat_algo_ops = batadv_algo_get(name);
    if (!bat_algo_ops)
        goto out;

    bat_priv->bat_algo_ops = bat_algo_ops;
    ret = 0;

out:
    return ret;
}

int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
{
    struct batadv_algo_ops *bat_algo_ops;
    struct hlist_node *node;

    seq_printf(seq, "Available routing algorithms:\n");

    hlist_for_each_entry(bat_algo_ops, node, &batadv_algo_list, list) {
        seq_printf(seq, "%s\n", bat_algo_ops->name);
    }

    return 0;
}

static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
{
    struct batadv_algo_ops *bat_algo_ops;
    char *algo_name = (char *)val;
    size_t name_len = strlen(algo_name);

    if (algo_name[name_len - 1] == '\n')
        algo_name[name_len - 1] = '\0';

    bat_algo_ops = batadv_algo_get(algo_name);
    if (!bat_algo_ops) {
        pr_err("Routing algorithm '%s' is not supported\n", algo_name);
        return -EINVAL;
    }

    return param_set_copystring(algo_name, kp);
}

static const struct kernel_param_ops batadv_param_ops_ra = {
    .set = batadv_param_set_ra,
    .get = param_get_string,
};

static struct kparam_string batadv_param_string_ra = {
    .maxlen = sizeof(batadv_routing_algo),
    .string = batadv_routing_algo,
};

module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
        0644);
module_init(batadv_init);
module_exit(batadv_exit);

MODULE_LICENSE("GPL");

MODULE_AUTHOR(BATADV_DRIVER_AUTHOR);
MODULE_DESCRIPTION(BATADV_DRIVER_DESC);
MODULE_SUPPORTED_DEVICE(BATADV_DRIVER_DEVICE);
MODULE_VERSION(BATADV_SOURCE_VERSION);