/* $Id: openssdpsocket.c,v 1.8 2011/10/07 09:21:03 nanard Exp $ */
/* MiniUPnP project
 * http://miniupnp.free.fr/ or http://miniupnp.tuxfamily.org/
 * (c) 2006-2011 Thomas Bernard
 * This software is subject to the conditions detailed
 * in the LICENCE file provided within the distribution */

#include "config.h"

#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <syslog.h>

#include "openssdpsocket.h"

/* SSDP ip/port */
#define SSDP_PORT (1900)
#define SSDP_MCAST_ADDR ("239.255.255.250")
/* Link Local and Site Local SSDP IPv6 multicast addresses */
#define LL_SSDP_MCAST_ADDR ("FF02::C")
#define SL_SSDP_MCAST_ADDR ("FF05::C")

/**
 * Get the IPv4 address from a string
 * representing the address or the interface name
 */
static in_addr_t
GetIfAddrIPv4(const char * ifaddr)
{
	in_addr_t addr;
	int s;
	struct ifreq ifr;
	int ifrlen;
	
	/* let's suppose ifaddr is a IPv4 address
	 * such as 192.168.1.1 */
	addr = inet_addr(ifaddr);
	if(addr != INADDR_NONE)
	{
		return addr;
	}
	/* let's suppose the ifaddr was in fact an interface name 
	 * such as eth0 */
	s = socket(PF_INET, SOCK_DGRAM, 0);
	if(s < 0)
	{
		syslog(LOG_ERR, "socket(PF_INET, SOCK_DGRAM): %m");
		return INADDR_NONE;
	}
	memset(&ifr, 0, sizeof(struct ifreq));
	strncpy(ifr.ifr_name, ifaddr, IFNAMSIZ);
	if(ioctl(s, SIOCGIFADDR, &ifr, &ifrlen) < 0)
	{
		syslog(LOG_ERR, "ioctl(s, SIOCGIFADDR, ...): %m");
		close(s);
		return INADDR_NONE;
	}
	syslog(LOG_DEBUG, "GetIfAddrIPv4(%s) = %s", ifaddr,
	       inet_ntoa(((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr));
	addr = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr;
	close(s);
	return addr;
}

/**
 * Add the multicast membership for SSDP on the interface
 * @param s	the socket
 * @param ifaddr	the IPv4 address or interface name
 * @param ipv6	IPv6 or IPv4
 * return -1 on error, 0 on success */
int
AddDropMulticastMembership(int s, const char * ifaddr, int ipv6, int drop)
{
	struct ip_mreq imr;	/* Ip multicast membership */
#ifdef ENABLE_IPV6
	struct ipv6_mreq mr;
	unsigned int ifindex;
#endif

#ifdef ENABLE_IPV6
	if(ipv6)
	{
		ifindex = if_nametoindex(ifaddr);
		memset(&mr, 0, sizeof(mr));
		inet_pton(AF_INET6, LL_SSDP_MCAST_ADDR, &mr.ipv6mr_multiaddr);
		mr.ipv6mr_interface = ifindex;
		if(setsockopt(s, IPPROTO_IPV6, drop ? IPV6_LEAVE_GROUP : IPV6_JOIN_GROUP,
		   &mr, sizeof(struct ipv6_mreq)) < 0)
		{
			syslog(LOG_ERR, "setsockopt(udp, %s)(%s): %m",
			       drop ? "IPV6_LEAVE_GROUP" : "IPV6_JOIN_GROUP",
			       ifaddr);
			return -1;
		}
		inet_pton(AF_INET6, SL_SSDP_MCAST_ADDR, &mr.ipv6mr_multiaddr);
		if(setsockopt(s, IPPROTO_IPV6, drop ? IPV6_LEAVE_GROUP : IPV6_JOIN_GROUP,
		   &mr, sizeof(struct ipv6_mreq)) < 0)
		{
			syslog(LOG_ERR, "setsockopt(udp, %s)(%s): %m",
			       drop ? "IPV6_LEAVE_GROUP" : "IPV6_JOIN_GROUP",
			       ifaddr);
			return -1;
		}
	}
	else
	{
#endif
	    /* setting up imr structure */
	    imr.imr_multiaddr.s_addr = inet_addr(SSDP_MCAST_ADDR);
	    /*imr.imr_interface.s_addr = htonl(INADDR_ANY);*/
	    /*imr.imr_interface.s_addr = inet_addr(ifaddr);*/
		imr.imr_interface.s_addr = GetIfAddrIPv4(ifaddr);
		if(imr.imr_interface.s_addr == INADDR_NONE)
		{
			syslog(LOG_ERR, "no IPv4 address for interface %s",
			       ifaddr);
			return -1;
		}
		
		if (setsockopt(s, IPPROTO_IP, drop ? IP_DROP_MEMBERSHIP : IP_ADD_MEMBERSHIP,
		    (void *)&imr, sizeof(struct ip_mreq)) < 0)
		{
	        syslog(LOG_ERR, "setsockopt(udp, %s)(%s): %m",
			       drop ? "IP_DROP_MEMBERSHIP" : "IP_ADD_MEMBERSHIP",
			       ifaddr);
			return -1;
	    }
#ifdef ENABLE_IPV6
	}
#endif

	return 0;
}

int
OpenAndConfSSDPReceiveSocket(int n_listen_addr,
							 const char * * listen_addr,
                             int ipv6)
{
	int s;
	int opt = 1;
#ifdef ENABLE_IPV6
	struct sockaddr_storage sockname;
#else
	struct sockaddr_in sockname;
#endif
	socklen_t sockname_len;
	
#ifdef ENABLE_IPV6
	if( (s = socket(ipv6 ? PF_INET6 : PF_INET, SOCK_DGRAM, 0)) < 0)
#else
	if( (s = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
#endif
	{
		syslog(LOG_ERR, "socket(udp): %m");
		return -1;
	}	
	
#ifdef ENABLE_IPV6
	memset(&sockname, 0, sizeof(struct sockaddr_storage));
	if(ipv6)
	{
#ifdef IPV6_V6ONLY
		if(setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY,
		              (char *)&opt, sizeof(opt)) < 0)
		{
			syslog(LOG_WARNING, "setsockopt(IPV6_V6ONLY): %m");
		}
#endif
		struct sockaddr_in6 * sa = (struct sockaddr_in6 *)&sockname;
    	sa->sin6_family = AF_INET6;
    	sa->sin6_port = htons(SSDP_PORT);
		sa->sin6_addr = in6addr_any;
		sockname_len = sizeof(struct sockaddr_in6);
	}
	else
	{
		struct sockaddr_in * sa = (struct sockaddr_in *)&sockname;
    	sa->sin_family = AF_INET;
    	sa->sin_port = htons(SSDP_PORT);
    	sa->sin_addr.s_addr = htonl(INADDR_ANY);
		sockname_len = sizeof(struct sockaddr_in);
	}
#else
	memset(&sockname, 0, sizeof(struct sockaddr_in));
    sockname.sin_family = AF_INET;
    sockname.sin_port = htons(SSDP_PORT);
	/* NOTE : it seems it doesnt work when binding on the specific address */
    /*sockname.sin_addr.s_addr = inet_addr(UPNP_MCAST_ADDR);*/
    sockname.sin_addr.s_addr = htonl(INADDR_ANY);
    /*sockname.sin_addr.s_addr = inet_addr(ifaddr);*/
	sockname_len = sizeof(struct sockaddr_in);
#endif

	if(setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0)
	{
		syslog(LOG_WARNING, "setsockopt(SO_REUSEADDR): %m");
	}

    if(bind(s, (struct sockaddr *)&sockname, sockname_len) < 0)
	{
		syslog(LOG_ERR, "bind(udp%s): %m", ipv6 ? "6" : "");
		close(s);
		return -1;
    }

	while(n_listen_addr>0)
	{
		n_listen_addr--;
		if(AddDropMulticastMembership(s, listen_addr[n_listen_addr], ipv6, 0) < 0)
		{
			syslog(LOG_WARNING, "Failed to add IPv%d multicast membership for interface %s.",
			       ipv6 ? 6 : 4,
			       listen_addr[n_listen_addr] );
		}
	}

	return s;
}