root/common/trunk/src/net_udp.c @ 3932

/*
 * FILE:     net_udp.c
 * AUTHOR:   Colin Perkins 
 * MODIFIED: Orion Hodson, Piers O'Hanlon, Kristian Hasler
 * 
 * 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

#ifdef WINXP_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 */
    struct in_addr      iface_addr;
};

#ifdef WIN32

#include <Iphlpapi.h>

/* 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
        va_start(ap, msg);
        vsnprintf(buffer, blen, msg, ap);
        va_end(ap);
        perror(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.
* note: setting the TTL never fails, so we have to try both.
*/

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);
                success = setsockopt(s, level, optname, 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;
}

uint32_t    udp_socket_addr4(socket_udp *s)
{
  if (s == NULL) {
    return 0;
  }

  if (s->mode != IPv4) {
    return 0;
  }

  return (uint32_t)(s->addr4.s_addr);  
}

uint16_t    udp_socket_txport(socket_udp *s)
{
        if (s == NULL) {
                return 0;
        }

        return s->tx_port;
}

int udp_socket_ttl(socket_udp *s)
{
        if (s == NULL) {
                return -1;
        }

        return s->ttl;
}

static socket_udp *udp_init4(const char *addr, const char *iface, uint16_t rx_port, uint16_t tx_port, int ttl)
{
        int                      reuse = 1, udpbufsize=131072;
        struct sockaddr_in       s_in;

#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, &s->iface_addr) != 1) {
                        debug_msg("Illegal interface specification\n");
                        free(s);
                        return NULL;
                }
        } else {
                s->iface_addr.s_addr = 0;
        }
        s->fd = socket(AF_INET, SOCK_DGRAM, 0);
        if (s->fd < 0) {
                socket_error("socket");
                return NULL;
        }
        if (SETSOCKOPT(s->fd, SOL_SOCKET, SO_SNDBUF, (char *) &udpbufsize, sizeof(udpbufsize)) != 0) {
                socket_error("setsockopt SO_SNDBUF");
                return NULL;
        }
        if (SETSOCKOPT(s->fd, SOL_SOCKET, SO_RCVBUF, (char *) &udpbufsize, sizeof(udpbufsize)) != 0) {
                socket_error("setsockopt SO_RCVBUF");
                return NULL;
        }
        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");
                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 = s->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 (s->iface_addr.s_addr != 0) {
                        if (SETSOCKOPT(s->fd, IPPROTO_IP, IP_MULTICAST_IF, (char *) &s->iface_addr, sizeof(s->iface_addr)) != 0) {
                                socket_error("setsockopt IP_MULTICAST_IF");
                                return NULL;
                        }
                }
        } else {
                if (SETSOCKOPT(s->fd, IPPROTO_IP, IP_TTL, (char *) &ttl, sizeof(ttl)) != 0) {
                        socket_error("setsockopt IP_TTL");
                        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 = s->iface_addr.s_addr;

                if (SETSOCKOPT(s->fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, (char *) &imr, sizeof(struct ip_mreq)) != 0) {
                        socket_error("setsockopt IP_DROP_MEMBERSHIP");
                        abort();
                }
                debug_msg("Dropped membership of multicast group\n");
        }
        close(s->fd);
        free(s->addr);
        free(s);
}

static inline int 
udp_send4(socket_udp *s, char *buffer, int buflen)
{
        struct sockaddr_in      s_in;
        
        assert(s != NULL);
        assert(s->mode == IPv4);
        assert(buffer != NULL);
        assert(buflen > 0);
        
        memset(&s_in, 0, sizeof(struct sockaddr_in));
        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 inline int 
udp_sendv4(socket_udp *s, struct iovec *vector, int count)
{
        struct msghdr           msg;
        struct sockaddr_in      s_in;
        
        assert(s != NULL);
        assert(s->mode == IPv4);
        
        s_in.sin_family      = AF_INET;
        s_in.sin_addr.s_addr = s->addr4.s_addr;
        s_in.sin_port        = htons(s->tx_port);

        msg.msg_name       = (caddr_t) &s_in;
        msg.msg_namelen    = sizeof(s_in);
        msg.msg_iov        = vector;
        msg.msg_iovlen     = count;
#ifdef HAVE_MSGHDR_MSGCTRL /* Solaris does something different here... can we just ignore these fields? [csp] */
        msg.msg_control    = 0;
        msg.msg_controllen = 0;
        msg.msg_flags      = 0;
#endif
        return sendmsg(s->fd, &msg, 0);
}
#endif

static const char *udp_host_addr4(void)
{
        static char              hname[MAXHOSTNAMELEN];
        struct hostent          *hent;
        struct in_addr           iaddr;
        
        if (gethostname(hname, MAXHOSTNAMELEN) != 0) {
                debug_msg("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 (const char*)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: 
                debug_msg("inet_pton failed\n");
                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) {
                debug_msg("Not yet implemented\n");
                abort();
        }

        if (inet_pton(AF_INET6, addr, &s->addr6) != 1) {
                /* We should probably try to do a DNS lookup on the name */
                /* here, but I'm trying to get the basics going first... */
                debug_msg("IPv6 address conversion failed\n");
                free(s);
                return NULL;    
        }
        s->fd = socket(AF_INET6, SOCK_DGRAM, 0);
        if (s->fd < 0) {
                socket_error("socket");
                return NULL;
        }
        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
        
        memset((char *)&s_in, 0, sizeof(s_in));
        s_in.sin6_family = AF_INET6;
        s_in.sin6_port   = htons(rx_port);
#ifdef HAVE_SIN6_LEN
        s_in.sin6_len    = sizeof(s_in);
#endif
        s_in.sin6_addr = in6addr_any;
        if (bind(s->fd, (struct sockaddr *) &s_in, sizeof(s_in)) != 0) {
                socket_error("bind");
                return NULL;
        }
        
        if (IN6_IS_ADDR_MULTICAST(&(s->addr6))) {
                unsigned int      loop = 1;
                struct ipv6_mreq  imr;
#ifdef MUSICA_IPV6
                imr.i6mr_interface = 1;
                imr.i6mr_multiaddr = s->addr6;
#else
                imr.ipv6mr_multiaddr = s->addr6;
                imr.ipv6mr_interface = 0;
#endif
                
                if (SETSOCKOPT(s->fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, (char *) &imr, sizeof(struct ipv6_mreq)) != 0) {
                        socket_error("setsockopt IPV6_ADD_MEMBERSHIP");
                        return NULL;
                }
                
                if (SETSOCKOPT(s->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, (char *) &loop, sizeof(loop)) != 0) {
                        socket_error("setsockopt IPV6_MULTICAST_LOOP");
                        return NULL;
                }
                if (SETSOCKOPT(s->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, (char *) &ttl, sizeof(ttl)) != 0) {
                        socket_error("setsockopt IPV6_MULTICAST_HOPS");
                        return NULL;
                }
        } else {
                if (SETSOCKOPT(s->fd, IPPROTO_IP, IP_TTL, (char *) &ttl, sizeof(ttl)) != 0) {
                        socket_error("setsockopt IP_TTL");
                        return NULL;
                }
        }

        assert(s != NULL);

        s->addr = strdup(addr);
        return s;
#else
        UNUSED(addr);
        UNUSED(iface);
        UNUSED(rx_port);
        UNUSED(tx_port);
        UNUSED(ttl);
        return NULL;
#endif
}

static void udp_exit6(socket_udp *s)
{
#ifdef HAVE_IPv6
        if (IN6_IS_ADDR_MULTICAST(&(s->addr6))) {
                struct ipv6_mreq  imr;
#ifdef MUSICA_IPV6
                imr.i6mr_interface = 1;
                imr.i6mr_multiaddr = s->addr6;
#else
                imr.ipv6mr_multiaddr = s->addr6;
                imr.ipv6mr_interface = 0;
#endif
                
                if (SETSOCKOPT(s->fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, (char *) &imr, sizeof(struct ipv6_mreq)) != 0) {
                        socket_error("setsockopt IPV6_DROP_MEMBERSHIP");
                        abort();
                }
        }
        close(s->fd);
        free(s->addr);
        free(s);
#else
        UNUSED(s);
#endif  /* HAVE_IPv6 */
}

static int udp_send6(socket_udp *s, char *buffer, int buflen)
{
#ifdef HAVE_IPv6
        struct sockaddr_in6     s_in;
        
        assert(s != NULL);
        assert(s->mode == IPv6);
        assert(buffer != NULL);
        assert(buflen > 0);
        
        memset((char *)&s_in, 0, sizeof(s_in));
        s_in.sin6_family = AF_INET6;
        s_in.sin6_addr   = s->addr6;
        s_in.sin6_port   = htons(s->tx_port);
#ifdef HAVE_SIN6_LEN
        s_in.sin6_len    = sizeof(s_in);
#endif
        return sendto(s->fd, buffer, buflen, 0, (struct sockaddr *) &s_in, sizeof(s_in));
#else
        UNUSED(s);
        UNUSED(buffer);
        UNUSED(buflen);
        return -1;
#endif
}

#ifndef WIN32
static int 
udp_sendv6(socket_udp *s, struct iovec *vector, int count)
{
#ifdef HAVE_IPv6
        struct msghdr           msg;
        struct sockaddr_in6     s_in;
        
        assert(s != NULL);
        assert(s->mode == IPv6);
        
        memset((char *)&s_in, 0, sizeof(s_in));
        s_in.sin6_family = AF_INET6;
        s_in.sin6_addr   = s->addr6;
        s_in.sin6_port   = htons(s->tx_port);
#ifdef HAVE_SIN6_LEN
        s_in.sin6_len    = sizeof(s_in);
#endif
        msg.msg_name       = &s_in;
        msg.msg_namelen    = sizeof(s_in);
        msg.msg_iov        = vector;
        msg.msg_iovlen     = count;
#ifdef HAVE_MSGHDR_MSGCTRL  
        msg.msg_control    = 0;
        msg.msg_controllen = 0;
        msg.msg_flags      = 0;
#endif
        return sendmsg(s->fd, &msg, 0);
#else
        UNUSED(s);
        UNUSED(vector);
        UNUSED(count);
        return -1;
#endif
}
#endif

static const char *udp_host_addr6(socket_udp *s)
{
#ifdef HAVE_IPv6
        static char              hname[MAXHOSTNAMELEN];
        int                      gai_err, newsock;
        struct addrinfo          hints, *ai;
        struct sockaddr_in6      local, addr6;
        uint32_t                        len = sizeof(local);
        int                                     result = 0;

        newsock=socket(AF_INET6, SOCK_DGRAM,0);
    memset ((char *)&addr6, 0, len);
    addr6.sin6_family = AF_INET6;
#ifdef HAVE_SIN6_LEN
    addr6.sin6_len    = len;
#endif
    bind (newsock, (struct sockaddr *) &addr6, len);
    addr6.sin6_addr = s->addr6;
    addr6.sin6_port = htons (s->rx_port);
    connect (newsock, (struct sockaddr *) &addr6, len);

    memset ((char *)&local, 0, len);
        if ((result = getsockname(newsock,(struct sockaddr *)&local, &len)) < 0){
                local.sin6_addr = in6addr_any;
                local.sin6_port = 0;
                debug_msg("getsockname failed\n");
        }

        close (newsock);

        if (IN6_IS_ADDR_UNSPECIFIED(&local.sin6_addr) || IN6_IS_ADDR_MULTICAST(&local.sin6_addr)) {
                if (gethostname(hname, MAXHOSTNAMELEN) != 0) {
                        debug_msg("gethostname failed\n");
                        abort();
                }
                
                hints.ai_protocol  = 0;
                hints.ai_flags     = 0;
                hints.ai_family    = AF_INET6;
                hints.ai_socktype  = SOCK_DGRAM;
                hints.ai_addrlen   = 0;
                hints.ai_canonname = NULL;
                hints.ai_addr      = NULL;
                hints.ai_next      = NULL;

                if ((gai_err = getaddrinfo(hname, NULL, &hints, &ai))) {
                        debug_msg("getaddrinfo: %s: %s\n", hname, gai_strerror(gai_err));
                        abort();
                }
                
                if (inet_ntop(AF_INET6, &(((struct sockaddr_in6 *)(ai->ai_addr))->sin6_addr), hname, MAXHOSTNAMELEN) == NULL) {
                        debug_msg("inet_ntop: %s: \n", hname);
                        abort();
                }
                freeaddrinfo(ai);
                return (const char*)hname;
        }
        if (inet_ntop(AF_INET6, &local.sin6_addr, hname, MAXHOSTNAMELEN) == NULL) {
                debug_msg("inet_ntop: %s: \n", hname);
                abort();
        }
        return (const char*)hname;
#else  /* HAVE_IPv6 */
        UNUSED(s);
        return "::";    /* The unspecified address... */
#endif /* HAVE_IPv6 */
}
        
/*****************************************************************************/
/* Generic functions, which call the appropriate protocol specific routines. */
/*****************************************************************************/

/**
 * udp_addr_valid:
 * @addr: string representation of IPv4 or IPv6 network address.
 *
 * Returns TRUE if @addr is valid, FALSE otherwise.
 **/

int udp_addr_valid(const char *addr)
{
        return udp_addr_valid4(addr) | udp_addr_valid6(addr);
}

/*
 * On Windows, determine the name of the interface
 * that will be used for this group.
 *
 * If we don't do this, rat will break on machines
 * with multiple network interfaces.
 */
#ifdef WIN32
static char *find_win32_interface(const char *addr)
{
    struct in_addr inaddr;
        char *iface = 0;

    if (inet_pton(AF_INET, addr, &inaddr))
    {
                MIB_IPFORWARDROW route;
                        
                debug_msg("got addr %x\n", inaddr.s_addr);
                if (GetBestRoute(inaddr.s_addr, 0, &route) == NO_ERROR)
                {
                        IP_ADAPTER_INFO oneinfo;
                        PIP_ADAPTER_INFO allinfo = 0;
                        int len;
                        struct in_addr dst, mask, nexthop;

                        dst.s_addr = route.dwForwardDest;
                        mask.s_addr = route.dwForwardMask;
                        nexthop.s_addr = route.dwForwardNextHop;

                        debug_msg("found route dst=%s mask=%s nexthop=%s ifindex=%d\n",
                                inet_ntoa(dst), inet_ntoa(mask), inet_ntoa(nexthop),
                                route.dwForwardIfIndex);

                        len = sizeof(oneinfo);
                        if (GetAdaptersInfo(&oneinfo, &len) == ERROR_SUCCESS)
                        {
                                debug_msg("got allinfo in one\n");
                                allinfo = &oneinfo;
                        }
                        else
                        {
                                allinfo = (PIP_ADAPTER_INFO) malloc(len);
                                if (GetAdaptersInfo(allinfo, &len) != ERROR_SUCCESS)
                                {
                                        debug_msg("Could not get adapter info\n");
                                        free(allinfo);
                                        allinfo = 0;
                                }
                        }

                        if (allinfo)
                        {

                                PIP_ADAPTER_INFO a;
                                {
                                        for (a = allinfo; a != 0; a = a->Next)
                                        {

                                                debug_msg("name='%s' desc='%s' index=%d\n", 
                                                        a->AdapterName, a->Description, a->Index);

                                                if (a->Index == route.dwForwardIfIndex)
                                                {
                                                        PIP_ADDR_STRING s;
                                                        /* Take the first address. */

                                                        s = &a->IpAddressList;
                                                        iface = _strdup(s->IpAddress.String);
                                                        debug_msg("Found address '%s'\n", iface);
                                                }
                                        }
                                }
                        }
#if 0 /* This is the stuff that just works on XP, sigh. */
                        len = sizeof(addrs);
                        if (GetAdaptersAddresses(AF_INET, 0, 0, addrs, &len) == ERROR_SUCCESS)
                        {
                                PIP_ADAPTER_ADDRESSES a;

                                a = addrs;

                                while (a && (iface == 0))
                                {
                                        if (a->IfIndex == route.dwForwardIfIndex)
                                        {
                                                struct sockaddr_in *sockaddr;
                                
                                                sockaddr = (struct sockaddr_in *) a->FirstUnicastAddress->Address.lpSockaddr;

                                                debug_msg("name=%s addr=%s\n", 
                                                        a->AdapterName, inet_ntoa(sockaddr->sin_addr));
                                                iface = _strdup(inet_ntoa(sockaddr->sin_addr));
                                        }
                                        a = a->Next;
                                }
                        }
#endif
                }
    }

        return iface;
}
#endif /* WIN32 */

/**
 * udp_init:
 * @addr: character string containing an IPv4 or IPv6 network address.
 * @rx_port: receive port.
 * @tx_port: transmit port.
 * @ttl: time-to-live value for transmitted packets.
 *
 * Creates a session for sending and receiving UDP datagrams over IP
 * networks. 
 *
 * Returns: a pointer to a valid socket_udp structure on success, NULL otherwise.
 **/
socket_udp *udp_init(const char *addr, uint16_t rx_port, uint16_t tx_port, int ttl)
{
        return udp_init_if(addr, NULL, rx_port, tx_port, ttl);
}

/**
 * udp_init_if:
 * @addr: character string containing an IPv4 or IPv6 network address.
 * @iface: character string containing an interface name.
 * @rx_port: receive port.
 * @tx_port: transmit port.
 * @ttl: time-to-live value for transmitted packets.
 *
 * Creates a session for sending and receiving UDP datagrams over IP
 * networks.  The session uses @iface as the interface to send and
 * receive datagrams on.
 * 
 * Return value: a pointer to a socket_udp structure on success, NULL otherwise.
 **/
socket_udp *udp_init_if(const char *addr, const char *iface, uint16_t rx_port, uint16_t tx_port, int ttl)
{
        socket_udp *res;
        
        if (strchr(addr, ':') == NULL) {
                char *computed_iface = 0;
                /* 
                 * On WIN32, if user did not pass an interface, 
                 * find the default interface for that address
                 * and pass it in .
                 */

#ifdef WIN32
                if (iface == 0)
                {
                        computed_iface = find_win32_interface(addr);
                        iface = computed_iface;
                }
#endif

                res = udp_init4(addr, iface, rx_port, tx_port, ttl);

                if (computed_iface)
                        free(computed_iface);

        } else {
                res = udp_init6(addr, iface, rx_port, tx_port, ttl);
        }
        return res;
}

/**
 * udp_exit:
 * @s: UDP session to be terminated.
 *
 * Closes UDP session.
 * 
 **/
void udp_exit(socket_udp *s)
{
    switch(s->mode) {
    case IPv4 : udp_exit4(s); break;
    case IPv6 : udp_exit6(s); break;
    default   : abort();
    }
}

/**
 * udp_send:
 * @s: UDP session.
 * @buffer: pointer to buffer to be transmitted.
 * @buflen: length of @buffer.
 * 
 * Transmits a UDP datagram containing data from @buffer.
 * 
 * Return value: 0 on success, -1 on failure.
 **/
int udp_send(socket_udp *s, char *buffer, int buflen)
{
        switch (s->mode) {
        case IPv4 : return udp_send4(s, buffer, buflen);
        case IPv6 : return udp_send6(s, buffer, buflen);
        default   : abort(); /* Yuk! */
        }
        return -1;
}


#ifndef WIN32
int         
udp_sendv(socket_udp *s, struct iovec *vector, int count)
{
        switch (s->mode) {
        case IPv4 : return udp_sendv4(s, vector, count);
        case IPv6 : return udp_sendv6(s, vector, count);
        default   : abort(); /* Yuk! */
        }
        return -1;
}
#endif

/**
 * udp_recv:
 * @s: UDP session.
 * @buffer: buffer to read data into.
 * @buflen: length of @buffer.
 * 
 * Reads from datagram queue associated with UDP session.
 *
 * Return value: number of bytes read, returns 0 if no data is available.
 **/
int udp_recv(socket_udp *s, char *buffer, int buflen)
{
        /* Reads data into the buffer, returning the number of bytes read.   */
        /* If no data is available, this returns the value zero immediately. */
        /* Note: since we don't care about the source address of the packet  */
        /* we receive, this function becomes protocol independent.           */
        int             len;

        assert(buffer != NULL);
        assert(buflen > 0);

        len = recvfrom(s->fd, buffer, buflen, 0, 0, 0);
        if (len > 0) {
                return len;
        }
        if (errno != ECONNREFUSED) {
                socket_error("recvfrom");
        }
        return 0;
}

/**
 * udp_fd_zero:
 * 
 * Clears file descriptor from set associated with UDP sessions (see select(2)).
 * 
 **/
void udp_fd_zero( fd_set *readset, fd_t *max_fd )
{
        FD_ZERO(readset);
        *max_fd = 0;
}

/**
 * udp_fd_set:
 * @s: UDP session.
 * 
 * Adds file descriptor associated of @s to set associated with UDP sessions.
 **/
void udp_fd_set( fd_set *readset, fd_t *max_fd, socket_udp *s)
{
        FD_SET(s->fd, readset);
        if (s->fd > (fd_t)*max_fd) {
                *max_fd = s->fd;
        }
}

/**
 * udp_fd_isset:
 * @s: UDP session.
 * 
 * Checks if file descriptor associated with UDP session is ready for
 * reading.  This function should be called after udp_select().
 *
 * Returns: non-zero if set, zero otherwise.
 **/
int udp_fd_isset( fd_set *readset, fd_t *max_fd, socket_udp *s)
{
        UNUSED(max_fd);

        return FD_ISSET(s->fd, readset);
}

/**
 * udp_select:
 * @timeout: maximum period to wait for data to arrive.
 * 
 * Waits for data to arrive for UDP sessions.
 * 
 * Return value: number of UDP sessions ready for reading.
 **/
int udp_select( fd_set *readset, fd_t max_fd, struct timeval *timeout)
{
        return select(max_fd + 1, readset, NULL, NULL, timeout);
}

/**
 * udp_host_addr:
 * @s: UDP session.
 * 
 * Return value: character string containing network address
 * associated with session @s.
 **/
const char *udp_host_addr(socket_udp *s)
{
        switch (s->mode) {
        case IPv4 : return udp_host_addr4();
        case IPv6 : return udp_host_addr6(s);
        default   : abort();
        }
        return NULL;
}

/**
 * udp_fd:
 * @s: UDP session.
 * 
 * This function allows applications to apply their own socketopt()'s
 * and ioctl()'s to the UDP session.
 * 
 * Return value: file descriptor of socket used by session @s.
 **/
int udp_fd(socket_udp *s)
{
        if (s && s->fd > 0) {
                return s->fd;
        } 
        return 0;
}