pcap_kern.c

Go to the documentation of this file.

/*
 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 * Licensed under the GPL.
 */

#include <linux/init.h>
#include <linux/netdevice.h>
#include <net_kern.h>
#include "pcap_user.h"

struct pcap_init {
    char *host_if;
    int promisc;
    int optimize;
    char *filter;
};

void pcap_init(struct net_device *dev, void *data)
{
    struct uml_net_private *pri;
    struct pcap_data *ppri;
    struct pcap_init *init = data;

    pri = netdev_priv(dev);
    ppri = (struct pcap_data *) pri->user;
    ppri->host_if = init->host_if;
    ppri->promisc = init->promisc;
    ppri->optimize = init->optimize;
    ppri->filter = init->filter;

    printk("pcap backend, host interface %s\n", ppri->host_if);
}

static int pcap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
    return pcap_user_read(fd, skb_mac_header(skb),
                  skb->dev->mtu + ETH_HEADER_OTHER,
                  (struct pcap_data *) &lp->user);
}

static int pcap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
    return -EPERM;
}

static const struct net_kern_info pcap_kern_info = {
    .init           = pcap_init,
    .protocol       = eth_protocol,
    .read           = pcap_read,
    .write          = pcap_write,
};

int pcap_setup(char *str, char **mac_out, void *data)
{
    struct pcap_init *init = data;
    char *remain, *host_if = NULL, *options[2] = { NULL, NULL };
    int i;

    *init = ((struct pcap_init)
        { .host_if  = "eth0",
          .promisc  = 1,
          .optimize     = 0,
          .filter   = NULL });

    remain = split_if_spec(str, &host_if, &init->filter,
                   &options[0], &options[1], mac_out, NULL);
    if (remain != NULL) {
        printk(KERN_ERR "pcap_setup - Extra garbage on "
               "specification : '%s'\n", remain);
        return 0;
    }

    if (host_if != NULL)
        init->host_if = host_if;

    for (i = 0; i < ARRAY_SIZE(options); i++) {
        if (options[i] == NULL)
            continue;
        if (!strcmp(options[i], "promisc"))
            init->promisc = 1;
        else if (!strcmp(options[i], "nopromisc"))
            init->promisc = 0;
        else if (!strcmp(options[i], "optimize"))
            init->optimize = 1;
        else if (!strcmp(options[i], "nooptimize"))
            init->optimize = 0;
        else {
            printk(KERN_ERR "pcap_setup : bad option - '%s'\n",
                   options[i]);
            return 0;
        }
    }

    return 1;
}

static struct transport pcap_transport = {
    .list       = LIST_HEAD_INIT(pcap_transport.list),
    .name       = "pcap",
    .setup      = pcap_setup,
    .user       = &pcap_user_info,
    .kern       = &pcap_kern_info,
    .private_size   = sizeof(struct pcap_data),
    .setup_size     = sizeof(struct pcap_init),
};

static int register_pcap(void)
{
    register_transport(&pcap_transport);
    return 0;
}

late_initcall(register_pcap);