soft-interface.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 "soft-interface.h"
#include "hard-interface.h"
#include "routing.h"
#include "send.h"
#include "debugfs.h"
#include "translation-table.h"
#include "hash.h"
#include "gateway_common.h"
#include "gateway_client.h"
#include "sysfs.h"
#include "originator.h"
#include <linux/slab.h>
#include <linux/ethtool.h>
#include <linux/etherdevice.h>
#include <linux/if_vlan.h>
#include "unicast.h"
#include "bridge_loop_avoidance.h"


static int batadv_get_settings(struct net_device *dev, struct ethtool_cmd *cmd);
static void batadv_get_drvinfo(struct net_device *dev,
                   struct ethtool_drvinfo *info);
static u32 batadv_get_msglevel(struct net_device *dev);
static void batadv_set_msglevel(struct net_device *dev, u32 value);
static u32 batadv_get_link(struct net_device *dev);
static void batadv_get_strings(struct net_device *dev, u32 stringset, u8 *data);
static void batadv_get_ethtool_stats(struct net_device *dev,
                     struct ethtool_stats *stats, u64 *data);
static int batadv_get_sset_count(struct net_device *dev, int stringset);

static const struct ethtool_ops batadv_ethtool_ops = {
    .get_settings = batadv_get_settings,
    .get_drvinfo = batadv_get_drvinfo,
    .get_msglevel = batadv_get_msglevel,
    .set_msglevel = batadv_set_msglevel,
    .get_link = batadv_get_link,
    .get_strings = batadv_get_strings,
    .get_ethtool_stats = batadv_get_ethtool_stats,
    .get_sset_count = batadv_get_sset_count,
};

int batadv_skb_head_push(struct sk_buff *skb, unsigned int len)
{
    int result;

    /* TODO: We must check if we can release all references to non-payload
     * data using skb_header_release in our skbs to allow skb_cow_header to
     * work optimally. This means that those skbs are not allowed to read
     * or write any data which is before the current position of skb->data
     * after that call and thus allow other skbs with the same data buffer
     * to write freely in that area.
     */
    result = skb_cow_head(skb, len);
    if (result < 0)
        return result;

    skb_push(skb, len);
    return 0;
}

static int batadv_interface_open(struct net_device *dev)
{
    netif_start_queue(dev);
    return 0;
}

static int batadv_interface_release(struct net_device *dev)
{
    netif_stop_queue(dev);
    return 0;
}

static struct net_device_stats *batadv_interface_stats(struct net_device *dev)
{
    struct batadv_priv *bat_priv = netdev_priv(dev);
    struct net_device_stats *stats = &bat_priv->stats;

    stats->tx_packets = batadv_sum_counter(bat_priv, BATADV_CNT_TX);
    stats->tx_bytes = batadv_sum_counter(bat_priv, BATADV_CNT_TX_BYTES);
    stats->tx_dropped = batadv_sum_counter(bat_priv, BATADV_CNT_TX_DROPPED);
    stats->rx_packets = batadv_sum_counter(bat_priv, BATADV_CNT_RX);
    stats->rx_bytes = batadv_sum_counter(bat_priv, BATADV_CNT_RX_BYTES);
    return stats;
}

static int batadv_interface_set_mac_addr(struct net_device *dev, void *p)
{
    struct batadv_priv *bat_priv = netdev_priv(dev);
    struct sockaddr *addr = p;
    uint8_t old_addr[ETH_ALEN];

    if (!is_valid_ether_addr(addr->sa_data))
        return -EADDRNOTAVAIL;

    memcpy(old_addr, dev->dev_addr, ETH_ALEN);
    memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);

    /* only modify transtable if it has been initialized before */
    if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_ACTIVE) {
        batadv_tt_local_remove(bat_priv, old_addr,
                       "mac address changed", false);
        batadv_tt_local_add(dev, addr->sa_data, BATADV_NULL_IFINDEX);
    }

    dev->addr_assign_type &= ~NET_ADDR_RANDOM;
    return 0;
}

static int batadv_interface_change_mtu(struct net_device *dev, int new_mtu)
{
    /* check ranges */
    if ((new_mtu < 68) || (new_mtu > batadv_hardif_min_mtu(dev)))
        return -EINVAL;

    dev->mtu = new_mtu;

    return 0;
}

static int batadv_interface_tx(struct sk_buff *skb,
                   struct net_device *soft_iface)
{
    struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
    struct batadv_priv *bat_priv = netdev_priv(soft_iface);
    struct batadv_hard_iface *primary_if = NULL;
    struct batadv_bcast_packet *bcast_packet;
    struct vlan_ethhdr *vhdr;
    __be16 ethertype = __constant_htons(BATADV_ETH_P_BATMAN);
    static const uint8_t stp_addr[ETH_ALEN] = {0x01, 0x80, 0xC2, 0x00, 0x00,
                           0x00};
    unsigned int header_len = 0;
    int data_len = skb->len, ret;
    short vid __maybe_unused = -1;
    bool do_bcast = false;
    uint32_t seqno;

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

    soft_iface->trans_start = jiffies;

    switch (ntohs(ethhdr->h_proto)) {
    case ETH_P_8021Q:
        vhdr = (struct vlan_ethhdr *)skb->data;
        vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;

        if (vhdr->h_vlan_encapsulated_proto != ethertype)
            break;

        /* fall through */
    case BATADV_ETH_P_BATMAN:
        goto dropped;
    }

    if (batadv_bla_tx(bat_priv, skb, vid))
        goto dropped;

    /* Register the client MAC in the transtable */
    batadv_tt_local_add(soft_iface, ethhdr->h_source, skb->skb_iif);

    /* don't accept stp packets. STP does not help in meshes.
     * better use the bridge loop avoidance ...
     */
    if (batadv_compare_eth(ethhdr->h_dest, stp_addr))
        goto dropped;

    if (is_multicast_ether_addr(ethhdr->h_dest)) {
        do_bcast = true;

        switch (atomic_read(&bat_priv->gw_mode)) {
        case BATADV_GW_MODE_SERVER:
            /* gateway servers should not send dhcp
             * requests into the mesh
             */
            ret = batadv_gw_is_dhcp_target(skb, &header_len);
            if (ret)
                goto dropped;
            break;
        case BATADV_GW_MODE_CLIENT:
            /* gateway clients should send dhcp requests
             * via unicast to their gateway
             */
            ret = batadv_gw_is_dhcp_target(skb, &header_len);
            if (ret)
                do_bcast = false;
            break;
        case BATADV_GW_MODE_OFF:
        default:
            break;
        }
    }

    /* ethernet packet should be broadcasted */
    if (do_bcast) {
        primary_if = batadv_primary_if_get_selected(bat_priv);
        if (!primary_if)
            goto dropped;

        if (batadv_skb_head_push(skb, sizeof(*bcast_packet)) < 0)
            goto dropped;

        bcast_packet = (struct batadv_bcast_packet *)skb->data;
        bcast_packet->header.version = BATADV_COMPAT_VERSION;
        bcast_packet->header.ttl = BATADV_TTL;

        /* batman packet type: broadcast */
        bcast_packet->header.packet_type = BATADV_BCAST;
        bcast_packet->reserved = 0;

        /* hw address of first interface is the orig mac because only
         * this mac is known throughout the mesh
         */
        memcpy(bcast_packet->orig,
               primary_if->net_dev->dev_addr, ETH_ALEN);

        /* set broadcast sequence number */
        seqno = atomic_inc_return(&bat_priv->bcast_seqno);
        bcast_packet->seqno = htonl(seqno);

        batadv_add_bcast_packet_to_list(bat_priv, skb, 1);

        /* a copy is stored in the bcast list, therefore removing
         * the original skb.
         */
        kfree_skb(skb);

    /* unicast packet */
    } else {
        if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_OFF) {
            ret = batadv_gw_out_of_range(bat_priv, skb, ethhdr);
            if (ret)
                goto dropped;
        }

        ret = batadv_unicast_send_skb(skb, bat_priv);
        if (ret != 0)
            goto dropped_freed;
    }

    batadv_inc_counter(bat_priv, BATADV_CNT_TX);
    batadv_add_counter(bat_priv, BATADV_CNT_TX_BYTES, data_len);
    goto end;

dropped:
    kfree_skb(skb);
dropped_freed:
    batadv_inc_counter(bat_priv, BATADV_CNT_TX_DROPPED);
end:
    if (primary_if)
        batadv_hardif_free_ref(primary_if);
    return NETDEV_TX_OK;
}

void batadv_interface_rx(struct net_device *soft_iface,
             struct sk_buff *skb, struct batadv_hard_iface *recv_if,
             int hdr_size, struct batadv_orig_node *orig_node)
{
    struct batadv_priv *bat_priv = netdev_priv(soft_iface);
    struct ethhdr *ethhdr;
    struct vlan_ethhdr *vhdr;
    struct batadv_header *batadv_header = (struct batadv_header *)skb->data;
    short vid __maybe_unused = -1;
    __be16 ethertype = __constant_htons(BATADV_ETH_P_BATMAN);
    bool is_bcast;

    is_bcast = (batadv_header->packet_type == BATADV_BCAST);

    /* check if enough space is available for pulling, and pull */
    if (!pskb_may_pull(skb, hdr_size))
        goto dropped;

    skb_pull_rcsum(skb, hdr_size);
    skb_reset_mac_header(skb);

    ethhdr = (struct ethhdr *)skb_mac_header(skb);

    switch (ntohs(ethhdr->h_proto)) {
    case ETH_P_8021Q:
        vhdr = (struct vlan_ethhdr *)skb->data;
        vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;

        if (vhdr->h_vlan_encapsulated_proto != ethertype)
            break;

        /* fall through */
    case BATADV_ETH_P_BATMAN:
        goto dropped;
    }

    /* skb->dev & skb->pkt_type are set here */
    if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
        goto dropped;
    skb->protocol = eth_type_trans(skb, soft_iface);

    /* should not be necessary anymore as we use skb_pull_rcsum()
     * TODO: please verify this and remove this TODO
     * -- Dec 21st 2009, Simon Wunderlich
     */

    /* skb->ip_summed = CHECKSUM_UNNECESSARY; */

    batadv_inc_counter(bat_priv, BATADV_CNT_RX);
    batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
               skb->len + ETH_HLEN);

    soft_iface->last_rx = jiffies;

    /* Let the bridge loop avoidance check the packet. If will
     * not handle it, we can safely push it up.
     */
    if (batadv_bla_rx(bat_priv, skb, vid, is_bcast))
        goto out;

    if (orig_node)
        batadv_tt_add_temporary_global_entry(bat_priv, orig_node,
                             ethhdr->h_source);

    if (batadv_is_ap_isolated(bat_priv, ethhdr->h_source, ethhdr->h_dest))
        goto dropped;

    netif_rx(skb);
    goto out;

dropped:
    kfree_skb(skb);
out:
    return;
}

static const struct net_device_ops batadv_netdev_ops = {
    .ndo_open = batadv_interface_open,
    .ndo_stop = batadv_interface_release,
    .ndo_get_stats = batadv_interface_stats,
    .ndo_set_mac_address = batadv_interface_set_mac_addr,
    .ndo_change_mtu = batadv_interface_change_mtu,
    .ndo_start_xmit = batadv_interface_tx,
    .ndo_validate_addr = eth_validate_addr
};

static void batadv_interface_setup(struct net_device *dev)
{
    struct batadv_priv *priv = netdev_priv(dev);

    ether_setup(dev);

    dev->netdev_ops = &batadv_netdev_ops;
    dev->destructor = free_netdev;
    dev->tx_queue_len = 0;

    /* can't call min_mtu, because the needed variables
     * have not been initialized yet
     */
    dev->mtu = ETH_DATA_LEN;
    /* reserve more space in the skbuff for our header */
    dev->hard_header_len = BATADV_HEADER_LEN;

    /* generate random address */
    eth_hw_addr_random(dev);

    SET_ETHTOOL_OPS(dev, &batadv_ethtool_ops);

    memset(priv, 0, sizeof(*priv));
}

struct net_device *batadv_softif_create(const char *name)
{
    struct net_device *soft_iface;
    struct batadv_priv *bat_priv;
    int ret;
    size_t cnt_len = sizeof(uint64_t) * BATADV_CNT_NUM;

    soft_iface = alloc_netdev(sizeof(*bat_priv), name,
                  batadv_interface_setup);

    if (!soft_iface)
        goto out;

    bat_priv = netdev_priv(soft_iface);

    /* batadv_interface_stats() needs to be available as soon as
     * register_netdevice() has been called
     */
    bat_priv->bat_counters = __alloc_percpu(cnt_len, __alignof__(uint64_t));
    if (!bat_priv->bat_counters)
        goto free_soft_iface;

    ret = register_netdevice(soft_iface);
    if (ret < 0) {
        pr_err("Unable to register the batman interface '%s': %i\n",
               name, ret);
        goto free_bat_counters;
    }

    atomic_set(&bat_priv->aggregated_ogms, 1);
    atomic_set(&bat_priv->bonding, 0);
    atomic_set(&bat_priv->bridge_loop_avoidance, 0);
    atomic_set(&bat_priv->ap_isolation, 0);
    atomic_set(&bat_priv->vis_mode, BATADV_VIS_TYPE_CLIENT_UPDATE);
    atomic_set(&bat_priv->gw_mode, BATADV_GW_MODE_OFF);
    atomic_set(&bat_priv->gw_sel_class, 20);
    atomic_set(&bat_priv->gw_bandwidth, 41);
    atomic_set(&bat_priv->orig_interval, 1000);
    atomic_set(&bat_priv->hop_penalty, 30);
    atomic_set(&bat_priv->log_level, 0);
    atomic_set(&bat_priv->fragmentation, 1);
    atomic_set(&bat_priv->bcast_queue_left, BATADV_BCAST_QUEUE_LEN);
    atomic_set(&bat_priv->batman_queue_left, BATADV_BATMAN_QUEUE_LEN);

    atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
    atomic_set(&bat_priv->bcast_seqno, 1);
    atomic_set(&bat_priv->tt.vn, 0);
    atomic_set(&bat_priv->tt.local_changes, 0);
    atomic_set(&bat_priv->tt.ogm_append_cnt, 0);
#ifdef CONFIG_BATMAN_ADV_BLA
    atomic_set(&bat_priv->bla.num_requests, 0);
#endif
    bat_priv->tt.last_changeset = NULL;
    bat_priv->tt.last_changeset_len = 0;
    bat_priv->tt.poss_change = false;

    bat_priv->primary_if = NULL;
    bat_priv->num_ifaces = 0;

    ret = batadv_algo_select(bat_priv, batadv_routing_algo);
    if (ret < 0)
        goto unreg_soft_iface;

    ret = batadv_sysfs_add_meshif(soft_iface);
    if (ret < 0)
        goto unreg_soft_iface;

    ret = batadv_debugfs_add_meshif(soft_iface);
    if (ret < 0)
        goto unreg_sysfs;

    ret = batadv_mesh_init(soft_iface);
    if (ret < 0)
        goto unreg_debugfs;

    return soft_iface;

unreg_debugfs:
    batadv_debugfs_del_meshif(soft_iface);
unreg_sysfs:
    batadv_sysfs_del_meshif(soft_iface);
unreg_soft_iface:
    free_percpu(bat_priv->bat_counters);
    unregister_netdevice(soft_iface);
    return NULL;

free_bat_counters:
    free_percpu(bat_priv->bat_counters);
free_soft_iface:
    free_netdev(soft_iface);
out:
    return NULL;
}

void batadv_softif_destroy(struct net_device *soft_iface)
{
    batadv_debugfs_del_meshif(soft_iface);
    batadv_sysfs_del_meshif(soft_iface);
    batadv_mesh_free(soft_iface);
    unregister_netdevice(soft_iface);
}

int batadv_softif_is_valid(const struct net_device *net_dev)
{
    if (net_dev->netdev_ops->ndo_start_xmit == batadv_interface_tx)
        return 1;

    return 0;
}

/* ethtool */
static int batadv_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
    cmd->supported = 0;
    cmd->advertising = 0;
    ethtool_cmd_speed_set(cmd, SPEED_10);
    cmd->duplex = DUPLEX_FULL;
    cmd->port = PORT_TP;
    cmd->phy_address = 0;
    cmd->transceiver = XCVR_INTERNAL;
    cmd->autoneg = AUTONEG_DISABLE;
    cmd->maxtxpkt = 0;
    cmd->maxrxpkt = 0;

    return 0;
}

static void batadv_get_drvinfo(struct net_device *dev,
                   struct ethtool_drvinfo *info)
{
    strcpy(info->driver, "B.A.T.M.A.N. advanced");
    strcpy(info->version, BATADV_SOURCE_VERSION);
    strcpy(info->fw_version, "N/A");
    strcpy(info->bus_info, "batman");
}

static u32 batadv_get_msglevel(struct net_device *dev)
{
    return -EOPNOTSUPP;
}

static void batadv_set_msglevel(struct net_device *dev, u32 value)
{
}

static u32 batadv_get_link(struct net_device *dev)
{
    return 1;
}

/* Inspired by drivers/net/ethernet/dlink/sundance.c:1702
 * Declare each description string in struct.name[] to get fixed sized buffer
 * and compile time checking for strings longer than ETH_GSTRING_LEN.
 */
static const struct {
    const char name[ETH_GSTRING_LEN];
} batadv_counters_strings[] = {
    { "tx" },
    { "tx_bytes" },
    { "tx_dropped" },
    { "rx" },
    { "rx_bytes" },
    { "forward" },
    { "forward_bytes" },
    { "mgmt_tx" },
    { "mgmt_tx_bytes" },
    { "mgmt_rx" },
    { "mgmt_rx_bytes" },
    { "tt_request_tx" },
    { "tt_request_rx" },
    { "tt_response_tx" },
    { "tt_response_rx" },
    { "tt_roam_adv_tx" },
    { "tt_roam_adv_rx" },
};

static void batadv_get_strings(struct net_device *dev, uint32_t stringset,
                   uint8_t *data)
{
    if (stringset == ETH_SS_STATS)
        memcpy(data, batadv_counters_strings,
               sizeof(batadv_counters_strings));
}

static void batadv_get_ethtool_stats(struct net_device *dev,
                     struct ethtool_stats *stats,
                     uint64_t *data)
{
    struct batadv_priv *bat_priv = netdev_priv(dev);
    int i;

    for (i = 0; i < BATADV_CNT_NUM; i++)
        data[i] = batadv_sum_counter(bat_priv, i);
}

static int batadv_get_sset_count(struct net_device *dev, int stringset)
{
    if (stringset == ETH_SS_STATS)
        return BATADV_CNT_NUM;

    return -EOPNOTSUPP;
}