mcast_kern.c
/*
* user-mode-linux networking multicast transport
* Copyright (C) 2001 by Harald Welte <laforge@gnumonks.org>
* 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 (buytenh@gnu.org) and
* James Leu (jleu@mindspring.net).
* 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 "mcast.h"
#include "net_kern.h"
struct mcast_init {
char *addr;
int port;
int ttl;
};
static void mcast_init(struct net_device *dev, void *data)
{
struct uml_net_private *pri;
struct mcast_data *dpri;
struct mcast_init *init = data;
pri = dev->priv;
dpri = (struct mcast_data *) pri->user;
dpri->addr = init->addr;
dpri->port = init->port;
dpri->ttl = init->ttl;
dpri->dev = dev;
printk("mcast backend multicast address: %s:%u, TTL:%u\n",
dpri->addr, dpri->port, dpri->ttl);
}
static int mcast_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 mcast_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
return mcast_user_write(fd, skb->data, skb->len,
(struct mcast_data *) &lp->user);
}
static const struct net_kern_info mcast_kern_info = {
.init = mcast_init,
.protocol = eth_protocol,
.read = mcast_read,
.write = mcast_write,
};
int mcast_setup(char *str, char **mac_out, void *data)
{
struct mcast_init *init = data;
char *port_str = NULL, *ttl_str = NULL, *remain;
char *last;
*init = ((struct mcast_init)
{ .addr = "239.192.168.1",
.port = 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->port = 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;
}
}
printk(KERN_INFO "Configured mcast device: %s:%u-%u\n", init->addr,
init->port, init->ttl);
return 1;
}
static struct transport mcast_transport = {
.list = LIST_HEAD_INIT(mcast_transport.list),
.name = "mcast",
.setup = mcast_setup,
.user = &mcast_user_info,
.kern = &mcast_kern_info,
.private_size = sizeof(struct mcast_data),
.setup_size = sizeof(struct mcast_init),
};
static int register_mcast(void)
{
register_transport(&mcast_transport);
return 0;
}
late_initcall(register_mcast);