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/*
* user-mode-linux networking multicast transport
* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Copyright (C) 2001 by Harald Welte <laforge@gnumonks.org>
*
* 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 <unistd.h>
#include <errno.h>
#include <netinet/in.h>
#include "mcast.h"
#include "net_user.h"
#include "um_malloc.h"
#include "user.h"
static struct sockaddr_in *new_addr(char *addr, unsigned short port)
{
struct sockaddr_in *sin;
sin = kmalloc(sizeof(struct sockaddr_in), UM_GFP_KERNEL);
if (sin == NULL) {
printk(UM_KERN_ERR "new_addr: allocation of sockaddr_in "
"failed\n");
return NULL;
}
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = in_aton(addr);
sin->sin_port = htons(port);
return sin;
}
static int mcast_user_init(void *data, void *dev)
{
struct mcast_data *pri = data;
pri->mcast_addr = new_addr(pri->addr, pri->port);
pri->dev = dev;
return 0;
}
static void mcast_remove(void *data)
{
struct mcast_data *pri = data;
kfree(pri->mcast_addr);
pri->mcast_addr = NULL;
}
static int mcast_open(void *data)
{
struct mcast_data *pri = data;
struct sockaddr_in *sin = pri->mcast_addr;
struct ip_mreq mreq;
int fd, yes = 1, err = -EINVAL;
if ((sin->sin_addr.s_addr == 0) || (sin->sin_port == 0))
goto out;
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0) {
err = -errno;
printk(UM_KERN_ERR "mcast_open : data socket failed, "
"errno = %d\n", errno);
goto out;
}
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
err = -errno;
printk(UM_KERN_ERR "mcast_open: SO_REUSEADDR failed, "
"errno = %d\n", errno);
goto out_close;
}
/* set ttl according to config */
if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &pri->ttl,
sizeof(pri->ttl)) < 0) {
err = -errno;
printk(UM_KERN_ERR "mcast_open: IP_MULTICAST_TTL failed, "
"error = %d\n", errno);
goto out_close;
}
/* set LOOP, so data does get fed back to local sockets */
if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
err = -errno;
printk(UM_KERN_ERR "mcast_open: IP_MULTICAST_LOOP failed, "
"error = %d\n", errno);
goto out_close;
}
/* bind socket to mcast address */
if (bind(fd, (struct sockaddr *) sin, sizeof(*sin)) < 0) {
err = -errno;
printk(UM_KERN_ERR "mcast_open : data bind failed, "
"errno = %d\n", errno);
goto out_close;
}
/* subscribe to the multicast group */
mreq.imr_multiaddr.s_addr = sin->sin_addr.s_addr;
mreq.imr_interface.s_addr = 0;
if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP,
&mreq, sizeof(mreq)) < 0) {
err = -errno;
printk(UM_KERN_ERR "mcast_open: IP_ADD_MEMBERSHIP failed, "
"error = %d\n", errno);
printk(UM_KERN_ERR "There appears not to be a multicast-"
"capable network interface on the host.\n");
printk(UM_KERN_ERR "eth0 should be configured in order to use "
"the multicast transport.\n");
goto out_close;
}
return fd;
out_close:
close(fd);
out:
return err;
}
static void mcast_close(int fd, void *data)
{
struct ip_mreq mreq;
struct mcast_data *pri = data;
struct sockaddr_in *sin = pri->mcast_addr;
mreq.imr_multiaddr.s_addr = sin->sin_addr.s_addr;
mreq.imr_interface.s_addr = 0;
if (setsockopt(fd, SOL_IP, IP_DROP_MEMBERSHIP,
&mreq, sizeof(mreq)) < 0) {
printk(UM_KERN_ERR "mcast_open: IP_DROP_MEMBERSHIP failed, "
"error = %d\n", errno);
}
close(fd);
}
int mcast_user_write(int fd, void *buf, int len, struct mcast_data *pri)
{
struct sockaddr_in *data_addr = pri->mcast_addr;
return net_sendto(fd, buf, len, data_addr, sizeof(*data_addr));
}
const struct net_user_info mcast_user_info = {
.init = mcast_user_init,
.open = mcast_open,
.close = mcast_close,
.remove = mcast_remove,
.add_address = NULL,
.delete_address = NULL,
.mtu = ETH_MAX_PACKET,
.max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER,
};
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