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/*
Copyright (C) 2006 Renaissance Technologies Corp.
main developer: HP Wei <hp@rentec.com>
This file collects functions related to setting multicast
for multicaster. They are IPv4 and IPv6 ready.
By default, we use IPv4.
To use IPv6, we need to specify -DIPv6 in Makefile.
The functions in this file are collected from
Richard Stevens' Networking bible: Unix Network programming
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING.
If not, write to the Free Software Foundation,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include "main.h"
#include <net/if.h>
#ifdef _SUN
#include <sys/sockio.h> /* define SIOCGIFADDR */
#else
#include <linux/sockios.h>
#endif
#define SA struct sockaddr
#define MAXSOCKADDR 128 /* max socket address structure size */
int sockfd_to_family(int sockfd)
{
union {
struct sockaddr sa;
char data[MAXSOCKADDR];
} un;
socklen_t len;
len = MAXSOCKADDR;
if (getsockname(sockfd, (SA *) un.data, &len) < 0)
return(-1);
return(un.sa.sa_family);
}
int mcast_set_if(int sockfd, const char *ifname, u_int ifindex)
{
switch (sockfd_to_family(sockfd)) {
case AF_INET: {
struct in_addr inaddr;
struct ifreq ifreq;
if (ifindex > 0) {
if (if_indextoname(ifindex, ifreq.ifr_name) == NULL) {
errno = ENXIO; /* i/f index not found */
return(-1);
}
goto doioctl;
} else if (ifname != NULL) {
strncpy(ifreq.ifr_name, ifname, IFNAMSIZ);
doioctl:
if (ioctl(sockfd, SIOCGIFADDR, &ifreq) < 0)
return(-1);
memcpy(&inaddr,
&((struct sockaddr_in *) &ifreq.ifr_addr)->sin_addr,
sizeof(struct in_addr));
} else
inaddr.s_addr = htonl(INADDR_ANY); /* remove prev. set default */
return(setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_IF,
&inaddr, sizeof(struct in_addr)));
}
#ifdef IPV6
case AF_INET6: {
u_int index;
if ( (index = ifindex) == 0) {
if (ifname == NULL) {
errno = EINVAL; /* must supply either index or name */
return(-1);
}
if ( (index = if_nametoindex(ifname)) == 0) {
errno = ENXIO; /* i/f name not found */
return(-1);
}
}
return(setsockopt(sockfd, IPPROTO_IPV6, IPV6_MULTICAST_IF,
&index, sizeof(index)));
}
#endif
default:
errno = EPROTONOSUPPORT;
return(-1);
}
}
int mcast_set_loop(int sockfd, int onoff)
{
switch (sockfd_to_family(sockfd)) {
case AF_INET: {
u_char flag;
flag = onoff;
return(setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_LOOP,
&flag, sizeof(flag)));
}
#ifdef IPV6
case AF_INET6: {
u_int flag;
flag = onoff;
return(setsockopt(sockfd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
&flag, sizeof(flag)));
}
#endif
default:
errno = EPROTONOSUPPORT;
return(-1);
}
}
/* end mcast_set_loop */
int mcast_set_ttl(int sockfd, int val)
{
switch (sockfd_to_family(sockfd)) {
case AF_INET: {
u_char ttl;
ttl = val;
return(setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL,
&ttl, sizeof(ttl)));
}
#ifdef IPV6
case AF_INET6: {
int hop;
hop = val;
return(setsockopt(sockfd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
&hop, sizeof(hop)));
}
#endif
default:
errno = EPROTONOSUPPORT;
return(-1);
}
}
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