tuntap_kern.c

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/*
 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 * Licensed under the GPL
 */

#include <linux/netdevice.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <asm/errno.h>
#include <net_kern.h>
#include "tuntap.h"

struct tuntap_init {
    char *dev_name;
    char *gate_addr;
};

static void tuntap_init(struct net_device *dev, void *data)
{
    struct uml_net_private *pri;
    struct tuntap_data *tpri;
    struct tuntap_init *init = data;

    pri = netdev_priv(dev);
    tpri = (struct tuntap_data *) pri->user;
    tpri->dev_name = init->dev_name;
    tpri->fixed_config = (init->dev_name != NULL);
    tpri->gate_addr = init->gate_addr;
    tpri->fd = -1;
    tpri->dev = dev;

    printk(KERN_INFO "TUN/TAP backend - ");
    if (tpri->gate_addr != NULL)
        printk(KERN_CONT "IP = %s", tpri->gate_addr);
    printk(KERN_CONT "\n");
}

static int tuntap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
    return net_read(fd, skb_mac_header(skb),
            skb->dev->mtu + ETH_HEADER_OTHER);
}

static int tuntap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
    return net_write(fd, skb->data, skb->len);
}

const struct net_kern_info tuntap_kern_info = {
    .init           = tuntap_init,
    .protocol       = eth_protocol,
    .read           = tuntap_read,
    .write          = tuntap_write,
};

int tuntap_setup(char *str, char **mac_out, void *data)
{
    struct tuntap_init *init = data;

    *init = ((struct tuntap_init)
        { .dev_name     = NULL,
          .gate_addr    = NULL });
    if (tap_setup_common(str, "tuntap", &init->dev_name, mac_out,
                &init->gate_addr))
        return 0;

    return 1;
}

static struct transport tuntap_transport = {
    .list       = LIST_HEAD_INIT(tuntap_transport.list),
    .name       = "tuntap",
    .setup      = tuntap_setup,
    .user       = &tuntap_user_info,
    .kern       = &tuntap_kern_info,
    .private_size   = sizeof(struct tuntap_data),
    .setup_size     = sizeof(struct tuntap_init),
};

static int register_tuntap(void)
{
    register_transport(&tuntap_transport);
    return 0;
}

late_initcall(register_tuntap);