slirp_kern.c

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

#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/string.h>
#include <net_kern.h>
#include <net_user.h>
#include "slirp.h"

struct slirp_init {
    struct arg_list_dummy_wrapper argw;  /* XXX should be simpler... */
};

void slirp_init(struct net_device *dev, void *data)
{
    struct uml_net_private *private;
    struct slirp_data *spri;
    struct slirp_init *init = data;
    int i;

    private = netdev_priv(dev);
    spri = (struct slirp_data *) private->user;

    spri->argw = init->argw;
    spri->pid = -1;
    spri->slave = -1;
    spri->dev = dev;

    slip_proto_init(&spri->slip);

    dev->hard_header_len = 0;
    dev->header_ops = NULL;
    dev->addr_len = 0;
    dev->type = ARPHRD_SLIP;
    dev->tx_queue_len = 256;
    dev->flags = IFF_NOARP;
    printk("SLIRP backend - command line:");
    for (i = 0; spri->argw.argv[i] != NULL; i++)
        printk(" '%s'",spri->argw.argv[i]);
    printk("\n");
}

static unsigned short slirp_protocol(struct sk_buff *skbuff)
{
    return htons(ETH_P_IP);
}

static int slirp_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
    return slirp_user_read(fd, skb_mac_header(skb), skb->dev->mtu,
                   (struct slirp_data *) &lp->user);
}

static int slirp_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
    return slirp_user_write(fd, skb->data, skb->len,
                (struct slirp_data *) &lp->user);
}

const struct net_kern_info slirp_kern_info = {
    .init           = slirp_init,
    .protocol       = slirp_protocol,
    .read           = slirp_read,
    .write          = slirp_write,
};

static int slirp_setup(char *str, char **mac_out, void *data)
{
    struct slirp_init *init = data;
    int i=0;

    *init = ((struct slirp_init) { .argw = { { "slirp", NULL  } } });

    str = split_if_spec(str, mac_out, NULL);

    if (str == NULL) /* no command line given after MAC addr */
        return 1;

    do {
        if (i >= SLIRP_MAX_ARGS - 1) {
            printk(KERN_WARNING "slirp_setup: truncating slirp "
                   "arguments\n");
            break;
        }
        init->argw.argv[i++] = str;
        while(*str && *str!=',') {
            if (*str == '_')
                *str=' ';
            str++;
        }
        if (*str != ',')
            break;
        *str++ = '\0';
    } while (1);

    init->argw.argv[i] = NULL;
    return 1;
}

static struct transport slirp_transport = {
    .list       = LIST_HEAD_INIT(slirp_transport.list),
    .name       = "slirp",
    .setup      = slirp_setup,
    .user       = &slirp_user_info,
    .kern       = &slirp_kern_info,
    .private_size   = sizeof(struct slirp_data),
    .setup_size     = sizeof(struct slirp_init),
};

static int register_slirp(void)
{
    register_transport(&slirp_transport);
    return 0;
}

late_initcall(register_slirp);