umcast_kern.c

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/*
 * user-mode-linux networking multicast transport
 * Copyright (C) 2001 by Harald Welte <[email protected]>
 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 *
 * based on the existing uml-networking code, which is
 * Copyright (C) 2001 Lennert Buytenhek ([email protected]) and
 * James Leu ([email protected]).
 * Copyright (C) 2001 by various other people who didn't put their name here.
 *
 * Licensed under the GPL.
 */

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

struct umcast_init {
    char *addr;
    int lport;
    int rport;
    int ttl;
    bool unicast;
};

static void umcast_init(struct net_device *dev, void *data)
{
    struct uml_net_private *pri;
    struct umcast_data *dpri;
    struct umcast_init *init = data;

    pri = netdev_priv(dev);
    dpri = (struct umcast_data *) pri->user;
    dpri->addr = init->addr;
    dpri->lport = init->lport;
    dpri->rport = init->rport;
    dpri->unicast = init->unicast;
    dpri->ttl = init->ttl;
    dpri->dev = dev;

    if (dpri->unicast) {
        printk(KERN_INFO "ucast backend address: %s:%u listen port: "
               "%u\n", dpri->addr, dpri->rport, dpri->lport);
    } else {
        printk(KERN_INFO "mcast backend multicast address: %s:%u, "
               "TTL:%u\n", dpri->addr, dpri->lport, dpri->ttl);
    }
}

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

static int umcast_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
    return umcast_user_write(fd, skb->data, skb->len,
                (struct umcast_data *) &lp->user);
}

static const struct net_kern_info umcast_kern_info = {
    .init           = umcast_init,
    .protocol       = eth_protocol,
    .read           = umcast_read,
    .write          = umcast_write,
};

static int mcast_setup(char *str, char **mac_out, void *data)
{
    struct umcast_init *init = data;
    char *port_str = NULL, *ttl_str = NULL, *remain;
    char *last;

    *init = ((struct umcast_init)
        { .addr = "239.192.168.1",
          .lport    = 1102,
          .ttl  = 1 });

    remain = split_if_spec(str, mac_out, &init->addr, &port_str, &ttl_str,
                   NULL);
    if (remain != NULL) {
        printk(KERN_ERR "mcast_setup - Extra garbage on "
               "specification : '%s'\n", remain);
        return 0;
    }

    if (port_str != NULL) {
        init->lport = simple_strtoul(port_str, &last, 10);
        if ((*last != '\0') || (last == port_str)) {
            printk(KERN_ERR "mcast_setup - Bad port : '%s'\n",
                   port_str);
            return 0;
        }
    }

    if (ttl_str != NULL) {
        init->ttl = simple_strtoul(ttl_str, &last, 10);
        if ((*last != '\0') || (last == ttl_str)) {
            printk(KERN_ERR "mcast_setup - Bad ttl : '%s'\n",
                   ttl_str);
            return 0;
        }
    }

    init->unicast = false;
    init->rport = init->lport;

    printk(KERN_INFO "Configured mcast device: %s:%u-%u\n", init->addr,
           init->lport, init->ttl);

    return 1;
}

static int ucast_setup(char *str, char **mac_out, void *data)
{
    struct umcast_init *init = data;
    char *lport_str = NULL, *rport_str = NULL, *remain;
    char *last;

    *init = ((struct umcast_init)
        { .addr     = "",
          .lport    = 1102,
          .rport    = 1102 });

    remain = split_if_spec(str, mac_out, &init->addr,
                   &lport_str, &rport_str, NULL);
    if (remain != NULL) {
        printk(KERN_ERR "ucast_setup - Extra garbage on "
               "specification : '%s'\n", remain);
        return 0;
    }

    if (lport_str != NULL) {
        init->lport = simple_strtoul(lport_str, &last, 10);
        if ((*last != '\0') || (last == lport_str)) {
            printk(KERN_ERR "ucast_setup - Bad listen port : "
                   "'%s'\n", lport_str);
            return 0;
        }
    }

    if (rport_str != NULL) {
        init->rport = simple_strtoul(rport_str, &last, 10);
        if ((*last != '\0') || (last == rport_str)) {
            printk(KERN_ERR "ucast_setup - Bad remote port : "
                   "'%s'\n", rport_str);
            return 0;
        }
    }

    init->unicast = true;

    printk(KERN_INFO "Configured ucast device: :%u -> %s:%u\n",
           init->lport, init->addr, init->rport);

    return 1;
}

static struct transport mcast_transport = {
    .list   = LIST_HEAD_INIT(mcast_transport.list),
    .name   = "mcast",
    .setup  = mcast_setup,
    .user   = &umcast_user_info,
    .kern   = &umcast_kern_info,
    .private_size   = sizeof(struct umcast_data),
    .setup_size = sizeof(struct umcast_init),
};

static struct transport ucast_transport = {
    .list   = LIST_HEAD_INIT(ucast_transport.list),
    .name   = "ucast",
    .setup  = ucast_setup,
    .user   = &umcast_user_info,
    .kern   = &umcast_kern_info,
    .private_size   = sizeof(struct umcast_data),
    .setup_size = sizeof(struct umcast_init),
};

static int register_umcast(void)
{
    register_transport(&mcast_transport);
    register_transport(&ucast_transport);
    return 0;
}

late_initcall(register_umcast);