/*
 * FILE:     net_udp.c
 * AUTHOR:   Colin Perkins 
 * MODIFIED: Orion Hodson & Piers O'Hanlon
 * 
 * Copyright (c) 1998-2000 University College London
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, is permitted provided that the following conditions 
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the Computer Science
 *      Department at University College London
 * 4. Neither the name of the University nor of the Department may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/* If this machine supports IPv6 the symbol HAVE_IPv6 should */
/* be defined in either config_unix.h or config_win32.h. The */
/* appropriate system header files should also be included   */
/* by those files.                                           */

#include "config_unix.h"
#include "config_win32.h"
#include "debug.h"
#include "memory.h"
#include "inet_pton.h"
#include "inet_ntop.h"
#include "vsnprintf.h"
#include "net_udp.h"

#ifdef NEED_ADDRINFO_H
#include "addrinfo.h"
#endif

#define IPv4	4
#define IPv6	6

#ifdef WIN2K_IPV6
const struct	in6_addr	in6addr_any = {IN6ADDR_ANY_INIT};
#endif

/* This is pretty nasty but it's the simplest way to get round */
/* the Detexis bug that means their MUSICA IPv6 stack uses     */
/* IPPROTO_IP instead of IPPROTO_IPV6 in setsockopt calls      */
/* We also need to define in6addr_any */
#ifdef  MUSICA_IPV6
#define	IPPROTO_IPV6	IPPROTO_IP
struct	in6_addr	in6addr_any = {IN6ADDR_ANY_INIT};

/* These DEF's are required as MUSICA's winsock6.h causes a clash with some of the 
 * standard ws2tcpip.h definitions (eg struct in_addr6).
 * Note: winsock6.h defines AF_INET6 as 24 NOT 23 as in winsock2.h - I have left it
 * set to the MUSICA value as this is used in some of their function calls. 
 */
//#define AF_INET6        23
#define IP_MULTICAST_LOOP      11 /*set/get IP multicast loopback */
#define	IP_MULTICAST_IF		9 /* set/get IP multicast i/f  */
#define	IP_MULTICAST_TTL       10 /* set/get IP multicast ttl */
#define	IP_MULTICAST_LOOP      11 /*set/get IP multicast loopback */
#define	IP_ADD_MEMBERSHIP      12 /* add an IP group membership */
#define	IP_DROP_MEMBERSHIP     13/* drop an IP group membership */

#define IN6_IS_ADDR_UNSPECIFIED(a) (((a)->s6_addr32[0] == 0) && \
									((a)->s6_addr32[1] == 0) && \
									((a)->s6_addr32[2] == 0) && \
									((a)->s6_addr32[3] == 0))
struct ip_mreq {
	struct in_addr imr_multiaddr;	/* IP multicast address of group */
	struct in_addr imr_interface;	/* local IP address of interface */
};
#endif

#ifndef INADDR_NONE
#define INADDR_NONE 0xffffffff
#endif

struct _socket_udp {
	int	 	 mode;	/* IPv4 or IPv6 */
        char	        *addr;
	uint16_t	 rx_port;
	uint16_t	 tx_port;
	ttl_t	 	 ttl;
	fd_t	 	 fd;
	struct in_addr	 addr4;
#ifdef HAVE_IPv6
	struct in6_addr	 addr6;
#endif /* HAVE_IPv6 */
};

#ifdef WIN32
/* Want to use both Winsock 1 and 2 socket options, but since
* IPv6 support requires Winsock 2 we have to add own backwards
* compatibility for Winsock 1.
*/
#define SETSOCKOPT winsock_versions_setsockopt
#else
#define SETSOCKOPT setsockopt
#endif /* WIN32 */

/*****************************************************************************/
/* Support functions...                                                      */
/*****************************************************************************/

static void
socket_error(const char *msg, ...)
{
	char		buffer[255];
	uint32_t	blen = sizeof(buffer) / sizeof(buffer[0]);
	va_list		ap;

#ifdef WIN32
#define WSERR(x) {#x,x}
	struct wse {
		char  errname[20];
		int my_errno;
	};
	struct wse ws_errs[] = {
		WSERR(WSANOTINITIALISED), WSERR(WSAENETDOWN),     WSERR(WSAEACCES),
		WSERR(WSAEINVAL),         WSERR(WSAEINTR),        WSERR(WSAEINPROGRESS),
		WSERR(WSAEFAULT),         WSERR(WSAENETRESET),    WSERR(WSAENOBUFS),
		WSERR(WSAENOTCONN),       WSERR(WSAENOTSOCK),     WSERR(WSAEOPNOTSUPP),
		WSERR(WSAESHUTDOWN),      WSERR(WSAEWOULDBLOCK),  WSERR(WSAEMSGSIZE),
		WSERR(WSAEHOSTUNREACH),   WSERR(WSAECONNABORTED), WSERR(WSAECONNRESET),
		WSERR(WSAEADDRNOTAVAIL),  WSERR(WSAEAFNOSUPPORT), WSERR(WSAEDESTADDRREQ),
		WSERR(WSAENETUNREACH),    WSERR(WSAETIMEDOUT),    WSERR(0)
	};
	
	int i, e = WSAGetLastError();
	i = 0;
	while(ws_errs[i].my_errno && ws_errs[i].my_errno != e) {
		i++;
	}
	va_start(ap, msg);
	_vsnprintf(buffer, blen, msg, ap);
	va_end(ap);
	printf("ERROR: %s, (%d - %s)\n", msg, e, ws_errs[i].errname);
#else
	uint32_t retlen;
	va_start(ap, msg);
	retlen = vsnprintf(buffer, blen, msg, ap);
	va_end(ap);
	blen -= retlen;
	snprintf(buffer + retlen, blen, ":%s", strerror(errno));
	rtp_message(LOG_ALERT, buffer);
#endif
}

#ifdef WIN32
/* ws2tcpip.h defines these constants with different values from
* winsock.h so files that use winsock 2 values but try to use 
* winsock 1 fail.  So what was the motivation in changing the
* constants ?
*/
#define WS1_IP_MULTICAST_IF     2 /* set/get IP multicast interface   */
#define WS1_IP_MULTICAST_TTL    3 /* set/get IP multicast timetolive  */
#define WS1_IP_MULTICAST_LOOP   4 /* set/get IP multicast loopback    */
#define WS1_IP_ADD_MEMBERSHIP   5 /* add  an IP group membership      */
#define WS1_IP_DROP_MEMBERSHIP  6 /* drop an IP group membership      */

/* winsock_versions_setsockopt tries 1 winsock version of option 
* optname and then winsock 2 version if that failed.
*/

static int
winsock_versions_setsockopt(SOCKET s, int level, int optname, const char FAR * optval, int optlen)
{
	int success = -1;
	switch (optname) {
	case IP_MULTICAST_IF:
		success = setsockopt(s, level, WS1_IP_MULTICAST_IF, optval, optlen);
		break;
	case IP_MULTICAST_TTL:
		success = setsockopt(s, level, WS1_IP_MULTICAST_TTL, optval, optlen);
		break;
	case IP_MULTICAST_LOOP:
		success = setsockopt(s, level, WS1_IP_MULTICAST_LOOP, optval, optlen);
		break;
	case IP_ADD_MEMBERSHIP: 
		success = setsockopt(s, level, WS1_IP_ADD_MEMBERSHIP, optval, optlen);
		break;
	case IP_DROP_MEMBERSHIP: 
		success = setsockopt(s, level, WS1_IP_DROP_MEMBERSHIP, optval, optlen);
		break;
	}
	if (success != -1) {
		return success;
	}
	return setsockopt(s, level, optname, optval, optlen);
}
#endif

#ifdef NEED_INET_ATON
#ifdef NEED_INET_ATON_STATIC
static 
#endif
int inet_aton(const char *name, struct in_addr *addr)
{
	addr->s_addr = inet_addr(name);
	return (addr->s_addr != (in_addr_t) INADDR_NONE);
}
#endif

#ifdef NEED_IN6_IS_ADDR_MULTICAST
#define IN6_IS_ADDR_MULTICAST(addr) ((addr)->s6_addr[0] == 0xffU)
#endif

#if defined(NEED_IN6_IS_ADDR_UNSPECIFIED) && defined(MUSICA_IPV6)
#define IN6_IS_ADDR_UNSPECIFIED(addr) IS_UNSPEC_IN6_ADDR(*addr)
#endif



/*****************************************************************************/
/* IPv4 specific functions...                                                */
/*****************************************************************************/

static int udp_addr_valid4(const char *dst)
{
        struct in_addr addr4;
	struct hostent *h;

	if (inet_pton(AF_INET, dst, &addr4)) {
		return TRUE;
	} 

	h = gethostbyname(dst);
	if (h != NULL) {
		return TRUE;
	}
	socket_error("Can't resolve IP address for %s", dst);

        return FALSE;
}

static socket_udp *udp_init4(const char *addr, const char *iface, uint16_t rx_port, uint16_t tx_port, int ttl)
{
	int                 	 reuse = 1;
	struct sockaddr_in  	 s_in;
	struct in_addr		 iface_addr;
#ifdef WIN32
	int recv_buf_size = 65536;
#endif
	socket_udp         	*s = (socket_udp *)malloc(sizeof(socket_udp));
	s->mode    = IPv4;
	s->addr    = NULL;
	s->rx_port = rx_port;
	s->tx_port = tx_port;
	s->ttl     = ttl;
	if (inet_pton(AF_INET, addr, &s->addr4) != 1) {
		struct hostent *h = gethostbyname(addr);
		if (h == NULL) {
			socket_error("Can't resolve IP address for %s", addr);
                        free(s);
			return NULL;
		}
		memcpy(&(s->addr4), h->h_addr_list[0], sizeof(s->addr4));
	}
	if (iface != NULL) {
		if (inet_pton(AF_INET, iface, &iface_addr) != 1) {
			rtp_message(LOG_ERR, "Illegal interface specification");
                        free(s);
			return NULL;
		}
	} else {
		iface_addr.s_addr = 0;
	}
	s->fd = socket(AF_INET, SOCK_DGRAM, 0);
	if (s->fd < 0) {
		socket_error("socket");
		return NULL;
	}
#ifdef WIN32
	if (SETSOCKOPT(s->fd, SOL_SOCKET, SO_RCVBUF, (char *)&recv_buf_size, sizeof(int)) != 0) {
	  socket_error("setsockopt SO_RCVBUF");
	  return NULL;
	}
#endif
	
	if (SETSOCKOPT(s->fd, SOL_SOCKET, SO_REUSEADDR, (char *) &reuse, sizeof(reuse)) != 0) {
		socket_error("setsockopt SO_REUSEADDR");
		return NULL;
	}
#ifdef SO_REUSEPORT
	if (SETSOCKOPT(s->fd, SOL_SOCKET, SO_REUSEPORT, (char *) &reuse, sizeof(reuse)) != 0) {
		socket_error("setsockopt SO_REUSEPORT");
		return NULL;
	}
#endif
	s_in.sin_family      = AF_INET;
	s_in.sin_addr.s_addr = INADDR_ANY;
	s_in.sin_port        = htons(rx_port);
	if (bind(s->fd, (struct sockaddr *) &s_in, sizeof(s_in)) != 0) {
		socket_error("bind: port %d", rx_port);
		return NULL;
	}
	if (IN_MULTICAST(ntohl(s->addr4.s_addr))) {
		char            loop = 1;
		struct ip_mreq  imr;
		
		imr.imr_multiaddr.s_addr = s->addr4.s_addr;
		imr.imr_interface.s_addr = iface_addr.s_addr;
		
		if (SETSOCKOPT(s->fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *) &imr, sizeof(struct ip_mreq)) != 0) {
			socket_error("setsockopt IP_ADD_MEMBERSHIP");
			return NULL;
		}
#ifndef WIN32
		if (SETSOCKOPT(s->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)) != 0) {
			socket_error("setsockopt IP_MULTICAST_LOOP");
			return NULL;
		}
#endif
		if (SETSOCKOPT(s->fd, IPPROTO_IP, IP_MULTICAST_TTL, (char *) &s->ttl, sizeof(s->ttl)) != 0) {
			socket_error("setsockopt IP_MULTICAST_TTL");
			return NULL;
		}
		if (iface_addr.s_addr != 0) {
			if (SETSOCKOPT(s->fd, IPPROTO_IP, IP_MULTICAST_IF, (char *) &iface_addr, sizeof(iface_addr)) != 0) {
				socket_error("setsockopt IP_MULTICAST_IF");
				return NULL;
			}
		}
	}
        s->addr = strdup(addr);
	return s;
}

static void udp_exit4(socket_udp *s)
{
	if (IN_MULTICAST(ntohl(s->addr4.s_addr))) {
		struct ip_mreq  imr;
		imr.imr_multiaddr.s_addr = s->addr4.s_addr;
		imr.imr_interface.s_addr = INADDR_ANY;
		if (SETSOCKOPT(s->fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, (char *) &imr, sizeof(struct ip_mreq)) != 0) {
			socket_error("setsockopt IP_DROP_MEMBERSHIP");
			abort();
		}
		rtp_message(LOG_INFO,  "Dropped membership of multicast group");
	}
	close(s->fd);
        free(s->addr);
	free(s);
}

static int udp_send4(socket_udp *s, uint8_t *buffer, int buflen)
{
	struct sockaddr_in	s_in;
	
	ASSERT(s != NULL);
	ASSERT(s->mode == IPv4);
	ASSERT(buffer != NULL);
	ASSERT(buflen > 0);
	
	s_in.sin_family      = AF_INET;
	s_in.sin_addr.s_addr = s->addr4.s_addr;
	s_in.sin_port        = htons(s->tx_port);
	return sendto(s->fd, buffer, buflen, 0, (struct sockaddr *) &s_in, sizeof(s_in));
}

#ifndef _WIN32
static int udp_send_iov4(socket_udp *s, struct iovec *iov, int count)
{
	struct sockaddr_in	s_in;
	struct msghdr 		msg;
	
	ASSERT(s != NULL);
	ASSERT(s->mode == IPv4);
	ASSERT(iov != NULL);
	ASSERT(count > 0);
	
	s_in.sin_family      = AF_INET;
	s_in.sin_addr.s_addr = s->addr4.s_addr;
	s_in.sin_port        = htons(s->tx_port);

	memset(&msg, 0, sizeof(msg));
	msg.msg_name 		 = (void *)&s_in;
	msg.msg_namelen 	 = sizeof(s_in);
	msg.msg_iov 		 = iov;
	msg.msg_iovlen 		 = count;

	return sendmsg(s->fd, &msg, 0);
}
#endif

static char *udp_host_addr4(void)
{
  char    		 hname[MAXHOSTNAMELEN];
  struct hostent 		*hent;
  struct in_addr  	 iaddr;
	
	if (gethostname(hname, MAXHOSTNAMELEN) != 0) {
		rtp_message(LOG_ERR, "Cannot get hostname!");
		abort();
	}
	hent = gethostbyname(hname);
	if (hent == NULL) {
		socket_error("Can't resolve IP address for %s", hname);
		return NULL;
	}
	ASSERT(hent->h_addrtype == AF_INET);
	memcpy(&iaddr.s_addr, hent->h_addr, sizeof(iaddr.s_addr));
	strncpy(hname, inet_ntoa(iaddr), MAXHOSTNAMELEN);
	return xstrdup(hname);
}

/*****************************************************************************/
/* IPv6 specific functions...                                                */
/*****************************************************************************/

static int udp_addr_valid6(const char *dst)
{
#ifdef HAVE_IPv6
        struct in6_addr addr6;
	switch (inet_pton(AF_INET6, dst, &addr6)) {
        case 1:  
                return TRUE;
                break;
        case 0: 
                return FALSE;
                break;
        case -1: 
                rtp_message(LOG_ERR, "inet_pton failed");
                errno = 0;
        }
#endif /* HAVE_IPv6 */
        UNUSED(dst);
        return FALSE;
}

static socket_udp *udp_init6(const char *addr, const char *iface, uint16_t rx_port, uint16_t tx_port, int ttl)
{
#ifdef HAVE_IPv6
	int                 reuse = 1;
	struct sockaddr_in6 s_in;
	socket_udp         *s = (socket_udp *) malloc(sizeof(socket_udp));
	s->mode    = IPv6;
	s->addr    = NULL;
	s->rx_port = rx_port;
	s->tx_port = tx_port;
	s->ttl     = ttl;
	
	if (iface != NULL) {