/* $EPIC: network.c,v 1.89 2014/07/22 22:03:51 jnelson Exp $ */
/*
 * network.c -- handles stuff dealing with connecting and name resolving
 *
 * Copyright © 1995, 2005 Jeremy Nelson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are 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
 *    notices, the above paragraph (the one permitting redistribution),
 *    this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The names of the author(s) may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS 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 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.
 */

#include "irc.h"
#include "ircaux.h"
#include "vars.h"
#include "newio.h"
#include "output.h"
#include <sys/ioctl.h>

/* This will eventually become a configurable */
#ifndef NO_JOB_CONTROL
#define ASYNC_DNS
#endif

#ifdef HAVE_SYS_UN_H
#include <sys/un.h>
typedef struct sockaddr_un USA;
#endif

static int	Connect 	 (int, SA *);
static socklen_t socklen  	 (SA *);
static int	Getnameinfo 	 (const SA *, socklen_t, char *, size_t, char *, size_t, int);
static int	Socket 		(int, int, int);

/*
   Retval    Meaning
   --------  -------------------------------------------
   -1        System call error occured (check errno)
   -2        The operation isn't supported for the requested family.
   -3        The hostname has an address, but not in the family you want.
   -4        The "address presentation" hostname can't be converted.
   -5        The hostname does not resolve.
   -6        The requested family does not have a virtual host.
   -7        The remote sockaddr to connect to was not provided.
   -8        The local sockaddr and remote sockaddr are different families.
   -9        The timeout expired before the connection was established.
   -10       The requested local address is in use or not available.
   -11       The connect()ion failed (at connect() time)
   -12       The connection could not be established (after connect() time)
   -13       The local sockaddr to bind was not provided.
   -14       The family request does not make sense.
*/

/*****************************************************************************/
/*
 * NAME: client_connect
 * USAGE: Create a new socket and establish both endpoints with the 
 *        arguments given.
 * ARGS: l - A local sockaddr structure representing the local side of
 *           the connection.  NULL is permitted.  If this value is NULL,
 *           then the local side of the connection will not be bind()ed.
 *       ll - The sizeof(l) -- if 0, then 'l' is treated as a NULL value.
 *       r - A remote sockaddr structure representing the remote side of
 *           the connection.  NULL is not permitted.
 *       rl - The sizeof(r) -- if 0, then 'r' is treated as a NULL value.
 *            Therefore, 0 is not permitted.
 */
int	client_connect (SA *l, socklen_t ll, SA *r, socklen_t rl)
{
	int	fd = -1;
	int	family = AF_UNSPEC;

	if (ll == 0)
		l = NULL;
	if (rl == 0)
		r = NULL;

	if (!r)
	{
		syserr(-1, "client_connect: remote addr missing (connect to who?)");
		return -1;
	}

	if (l && r && l->sa_family != r->sa_family)
	{
		syserr(-1, "client_connect: local addr protocol (%d) is different "
			"from remote addr protocol (%d)", 
			l->sa_family, r->sa_family);
		return -1;
	}

	if (l)
		family = l->sa_family;
	if (r)
		family = r->sa_family;

	if ((fd = Socket(family, SOCK_STREAM, 0)) < 0)
	{
		syserr(-1, "client_connect: socket(%d) failed: %s", 
						family, strerror(errno));
		return -1;
	}

	if (family == AF_UNIX || family == AF_INET 
#ifdef INET6
			      || family == AF_INET6
#endif
							 )
	{
		if (l && bind(fd, l, ll))
		{
		    syserr(-1, "client_connect: bind(%d) failed: %s", 
						fd, strerror(errno));
		    close(fd);
		    return -1;
		}

		if (Connect(fd, r))
		{
		    syserr(-1, "client_connect: connect(%d) failed: %s", 
						fd, strerror(errno));
		    close(fd);
		    return -1;
		}
	}
	else
	{
	    syserr(-1, "client_connect: protocol (%d) not supported", family);
	    return -1;
	}

	if (x_debug & DEBUG_SERVER_CONNECT)
		yell("Connected on des [%d]", fd);
	return fd;
}


/*****************************************************************************/
/*
 * NAME: ip_bindery
 * USAGE: Establish a local passive (listening) socket at the given port.
 * ARGS: family - AF_INET is the only supported argument.
 *       port - The port to establish the connection upon.  May be 0, 
 *		which requests any open port.
 *	 storage - Pointer to a sockaddr structure big enough for the
 *		   specified family.  Upon success, it will be filled with
 *		   the local sockaddr of the new connection.
 * NOTES: In most cases, the local address for 'storage' will be INADDR_ANY
 *        which doesn't really give you any useful information.  It is not
 *        possible to authoritatively figure out the local IP address
 *        without using ioctl().  However, we guess the best we may.
 *
 * NOTES: This function lacks IPv6 support.
 *        This function lacks Unix Domain Socket support.
 */
int	ip_bindery (int family, unsigned short port, SS *storage)
{
	socklen_t len;
	int	fd;

	if (inet_vhostsockaddr(family, port, NULL, storage, &len))
	{
		syserr(-1, "ip_bindery: inet_vhostsockaddr(%d,%d) failed.", 
							family, port);
		return -1;
	}

	if (!len)
	{
		syserr(-1, "ip_bindery: inet_vhostsockaddr(%d,%d) didn't "
			"return an address I could bind", family, port);
		return -1;
	}

	if ((fd = client_bind((SA *)storage, len)) < 0)
	{
		syserr(-1, "ip_bindery: client_bind(%d,%d) failed.", family, port);
		return -1;
	}

	return fd;
}

/*
 * NAME: client_bind
 * USAGE: Create a new socket and establish one endpoint with the arguments
 *        given.
 * ARGS: local - A local sockaddr structure representing the local side of
 *               the connection.  NULL is not permitted.
 *       local_len - The sizeof(l) -- if 0, then 'l' is treated as a NULL 
 *		     value.  Therefore, 0 is not permitted.
 */
int	client_bind (SA *local, socklen_t local_len)
{
	int	fd = -1;
	int	family = AF_UNSPEC;

	if (local_len == 0)
		local = NULL;
	if (!local)
	{
		syserr(-1, "client_bind: address to bind to not provided");
		return -1;
	}

	family = local->sa_family;

	if ((fd = Socket(family, SOCK_STREAM, 0)) < 0)
	{
		syserr(-1, "client_bind: socket(%d) failed: %s", 
					family, strerror(errno));
		return -1;
	}

#ifdef IP_PORTRANGE
	/*
	 * On 4.4BSD systems, this socket option asks the
	 * operating system to select a port from the "high
	 * port range" when we ask for port 0 (any port).
	 * Maybe some day Linux will support this.
	 */
	if (family == AF_INET && getenv("EPIC_USE_HIGHPORTS"))
	{
		int ports = IP_PORTRANGE_HIGH;
		setsockopt(fd, IPPROTO_IP, IP_PORTRANGE, 
				(char *)&ports, sizeof(ports));
	}
#endif

	if (bind(fd, local, local_len))
	{
		syserr(-1, "client_bind: bind(%d) failed: %s", 
					fd, strerror(errno));
		close(fd);
		return -1;
	}

	/*
	 * Get the local sockaddr of the passive socket,
	 * specifically the port number, and stash it in
	 * 'port' which is the return value to the caller.
	 */	
	if (getsockname(fd, (SA *)local, &local_len))
	{
		syserr(-1, "client_bind: getsockname(%d) failed: %s", 
					fd, strerror(errno));
		close(fd);
		return -1;
	}

	if (listen(fd, 4) < 0)
	{
		syserr(-1, "client_bind: listen(%d,4) failed: %s",
					fd, strerror(errno));
		close(fd);
		return -1;
	}

	return fd;
}

/*****************************************************************************/
/*
 * NAME: inet_vhostsockaddr
 * USAGE: Get the sockaddr of the current virtual host, if one is in use.
 * ARGS: family - The family whose sockaddr info is to be retrieved
 *       storage - Pointer to a sockaddr structure appropriate for family.
 *       len - This will be set to the size of the sockaddr structure that
 *             was copied, or set to 0 if no virtual host is available in
 *             the given family.
 * NOTES: If "len" is set to 0, do not attempt to bind() 'storage'!
 */
int	inet_vhostsockaddr (int family, int port, const char *wanthost, SS *storage, socklen_t *len)
{
	char	p_port[12];
	char	*p = NULL;
	AI	hints, *res;
	int	err;
	const char *lhn;

	/*
	 * If port == -1, AND "wanthost" is NULL, then this is a client connection, 
	 * so we punt if there is no virtual host name.  But if port is NOT zero, 
	 * then the caller expects us to return a sockaddr they can bind() to, 
	 * so we need to use LocalIPv(4|6)HostName, even if it's NULL.  If you 
	 * return *len == 0 for port != -1, then /dcc breaks.
	 */
	if ((family == AF_UNIX) || 
            (family == AF_INET && port == -1 && empty(wanthost) && LocalIPv4HostName == NULL) 
#ifdef INET6
	 || (family == AF_INET6 && port == -1 && empty(wanthost) && LocalIPv6HostName == NULL)
#endif
									   )
	{
		*len = 0;
		return 0;		/* No vhost needed */
	}

	if (wanthost && *wanthost)
		lhn = wanthost;
	else if (family == AF_INET)
		lhn = LocalIPv4HostName;
#ifdef INET6
	else if (family == AF_INET6)
		lhn = LocalIPv6HostName;
#endif
	else
		lhn = NULL;

	/*
	 * Can it really be this simple?
	 */
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = family;
	hints.ai_socktype = SOCK_STREAM;
	if (port != -1) 
	{
		hints.ai_flags = AI_PASSIVE;
		snprintf(p_port, 12, "%u", port);
		p = p_port;
	}

	if ((err = my_getaddrinfo(lhn, p, &hints, &res)))
	{
		syserr(-1, "inet_vhostsockaddr: my_getaddrinfo(%s,%s) failed: %s", 
				lhn, p, gai_strerror(err));
		return -1;
	}

	memcpy(storage, res->ai_addr, res->ai_addrlen);
	my_freeaddrinfo(res);
	*len = socklen((SA *)storage);
	return 0;
}

/************************************************************************/
/*
 * NAME: inet_strton
 * USAGE: Convert "any" kind of address represented by a string into
 *	  a socket address suitable for connect()ing or bind()ing with.
 * ARGS: hostname - The address to convert.  It may be any of the following:
 *		IPv4 "Presentation Address"	(A.B.C.D)
 *		IPv6 "Presentation Address"	(A:B::C:D)
 *		Hostname			(foo.bar.com)
 *		32 bit host order ipv4 address	(2134546324)
 *	 storage - A pointer to a (struct sockaddr_storage) with the 
 *		"family" argument filled in (AF_INET or AF_INET6).  
 *		If "hostname" is a p-addr, then the form of the p-addr
 *		must agree with the family in 'storage'.
 */
int	inet_strton (const char *host, const char *port, SA *storage, int flags)
{
	int family = storage->sa_family;

        /* First check for legacy 32 bit integer DCC addresses */
	if ((family == AF_INET || family == AF_UNSPEC) && host && is_number(host))
	{
		((ISA *)storage)->sin_family = AF_INET;
#ifdef HAVE_SA_LEN
		((ISA *)storage)->sin_len = sizeof(ISA);
#endif
		((ISA *)storage)->sin_addr.s_addr = htonl(strtoul(host, NULL, 10));
		if (port)
			((ISA *)storage)->sin_port = htons((unsigned short)strtoul(port, NULL, 10));
		return 0;
	}
	else
	{
		AI hints;
		AI *results;
		int retval;

		memset(&hints, 0, sizeof(hints));
		hints.ai_flags = flags;
		hints.ai_family = family;
		hints.ai_socktype = SOCK_STREAM;
		hints.ai_protocol = 0;

		if ((retval = my_getaddrinfo(host, port, &hints, &results))) 
		{
			syserr(-1, "inet_strton: my_getaddrinfo(%s,%s) failed: %s", 
					host, port, gai_strerror(retval));
			return -1;
		}

		/* memcpy can bite me. */
		memcpy(storage, results->ai_addr, results->ai_addrlen);

		my_freeaddrinfo(results);
		return 0;
	}
}

/*
 * NAME: inet_ntostr
 * USAGE: Convert a "sockaddr name" (SA) into a Hostname/p-addr
 * PLAIN ENGLISH: Convert getpeername() into "foo.bar.com"
 * ARGS: name - The socket address, possibly returned by getpeername().
 *       retval - A string to store the hostname/paddr (RETURN VALUE)
 *       size - The length of 'retval' in bytes
 * RETURN VALUE: "retval" is returned upon success
 *		 "empty_string" is returned for any error.
 *
 * NOTES: 'flags' should be set to NI_NAMEREQD if you don't want the remote
 *        host's p-addr if it does not have a DNS hostname.
 */
int	inet_ntostr (SA *name, char *host, int hsize, char *port, int psize, int flags)
{
	int	retval;
	socklen_t len;

	len = socklen(name);
	if ((retval = Getnameinfo(name, len, host, hsize, port, psize, 
					flags | NI_NUMERICSERV))) 
	{
		syserr(-1, "inet_ntostr: Getnameinfo(sockaddr->p_addr) failed: %s", 
					gai_strerror(retval));
		return -1;
	}

	return 0;
}

/* * * * * * * * * */
/* Only used by $convert() and $nametoip() */
/*
 * NAME: inet_hntop
 * USAGE: Convert a Hostname into a "presentation address" (p-addr)
 * PLAIN ENGLISH: Convert "A.B.C.D" into "foo.bar.com"
 * ARGS: family - The family whose presesentation address format to use
 *	 host - The hostname to convert
 *       retval - A string to store the p-addr (RETURN VALUE)
 *       size - The length of 'retval' in bytes
 * RETURN VALUE: "retval" is returned upon success
 *		 "empty_string" is returned for any error.
 */
int	inet_hntop (int family, const char *host, char *retval, int size)
{
	SS	buffer;

	((SA *)&buffer)->sa_family = family;
	if (inet_strton(host, NULL, (SA *)&buffer, AI_ADDRCONFIG))
	{
		syserr(-1, "inet_hntop: inet_strton(%d,%s) failed", family, host);
		return -1;
	}

	if (inet_ntostr((SA *)&buffer, retval, size, NULL, 0, NI_NUMERICHOST))
	{
		syserr(-1, "inet_hntop: inet_ntostr(%d,%s) failed", family, host);
		return -1;
	}

	return 0;
}

/* Only used by $convert() and $iptoname() */
/*
 * NAME: inet_ptohn
 * USAGE: Convert a "presentation address" (p-addr) into a Hostname
 * PLAIN ENGLISH: Convert "foo.bar.com" into "A.B.C.D"
 * ARGS: family - The family whose presesentation address format to use
 *	 ip - The presentation-address to look up
 *       retval - A string to store the hostname (RETURN VALUE)
 *       size - The length of 'retval' in bytes
 * RETURN VALUE: "retval" is returned upon success
 *		 "empty_string" is returned for any error.
 */
int	inet_ptohn (int family, const char *ip, char *retval, int size)
{
	SS	buffer;

	memset((char *)&buffer, 0, sizeof(buffer));
	((SA *)&buffer)->sa_family = family;
	if (inet_strton(ip, NULL, (SA *)&buffer, AI_NUMERICHOST))
	{
		syserr(-1, "inet_ptohn: inet_strton(%d,%s) failed", family, ip);
		return -1;
	}

	if (inet_ntostr((SA *)&buffer, retval, size, NULL, 0, NI_NAMEREQD))
	{
		syserr(-1, "inet_ptohn: inet_ntostr(%d,%s) failed", family, ip);
		return -1;
	}

	return 0;
}

/* Only used by $convert() */
/*
 * NAME: one_to_another
 * USAGE: Convert a p-addr to a Hostname, or a Hostname to a p-addr.
 * PLAIN ENGLISH: Convert "A.B.C.D" to "foo.bar.com" or convert "foo.bar.com"
 *                into "A.B.C.D"
 * ARGS: family - The address family in which to convert (AF_INET/AF_INET6)
 *	 what - Either a Hostname or a p-addr.
 *       retval - If "what" is a Hostname, a place to store the p-addr
 *                If "what" is a p-addr, a place to store the Hostname
 *       size - The length of 'retval' in bytes
 * RETURN VALUE: "retval" is returned upon success
 *		 "empty_string" is returned for any error.
 *
 * NOTES: If "what" is a p-addr and there is no hostname associated with that 
 *        address, that is considered an error and empty_string is returned.
 */
int	one_to_another (int family, const char *what, char *retval, int size)
{
	/* XXX I wish this wasn't necessary */
	int	old_window_display = window_display;
	window_display = 0;

	if (inet_ptohn(family, what, retval, size))
	{
		if (inet_hntop(family, what, retval, size))
		{
			window_display = old_window_display;
			syserr(-1, "one_to_another: both inet_ptohn and "
					"inet_hntop failed (%d,%s)", 
					family, what);
			return -1;
		}
	}

	window_display = old_window_display;
	return 0;
}

/****************************************************************************/
int	set_non_blocking (int fd)
{
	int	flag, rval;

#if defined(O_NONBLOCK)
	flag = O_NONBLOCK;
#elif defined(O_NDELAY)
	flag = O_NDELAY;
#elif defined(FIONBIO)
	flag = 1;
#else
	yell("Sorry!  Can't set nonblocking on this system!");
#endif

#if defined(O_NONBLOCK) || defined(O_NDELAY)
	if ((rval = fcntl(fd, F_GETFL, 0)) == -1)
	{
		syserr(-1, "set_non_blocking: fcntl(%d, F_GETFL) failed: %s",
				fd, strerror(errno));
		return -1;
	}
	if (fcntl(fd, F_SETFL, rval | flag) == -1)
	{
		syserr(-1, "set_non_blocking: fcntl(%d, F_SETFL) failed: %s",
				fd, strerror(errno));
		return -1;
	}
#else
	if (ioctl(fd, FIONBIO, &flag) < 0)
	{
		syserr(-1, "set_non_blocking: ioctl(%d, FIONBIO) failed: %s",
				fd, strerror(errno));
		return -1;
	}
#endif
	return 0;
}

int	set_blocking (int fd)
{
	int	flag, rval;

#if defined(O_NONBLOCK)
	flag = O_NONBLOCK;
#elif defined(O_NDELAY)
	flag = O_NDELAY;
#elif defined(FIONBIO)
	flag = 0;
#else
	yell("Sorry!  Can't set nonblocking on this system!");
#endif

#if defined(O_NONBLOCK) || defined(O_NDELAY)
	if ((rval = fcntl(fd, F_GETFL, 0)) == -1)
	{
		syserr(-1, "set_blocking: fcntl(%d, F_GETFL) failed: %s",
				fd, strerror(errno));
		return -1;
	}
	if (fcntl(fd, F_SETFL, rval & ~flag) == -1)
	{
		syserr(-1, "set_blocking: fcntl(%d, F_SETFL) failed: %s",
				fd, strerror(errno));
		return -1;
	}
#else
	if (ioctl(fd, FIONBIO, &flag) < 0)
	{
		syserr(-1, "set_blocking: ioctl(%d, FIONBIO) failed: %s",
				fd, strerror(errno));
		return -1;
	}
#endif
	return 0;
}

/****************************************************************************/
/*
 * It is possible for a race condition to exist; such that select()
 * indicates that a listen()ing socket is able to recieve a new connection
 * and that a later accept() call will still block because the connection
 * has been closed in the interim.  This wrapper for accept() attempts to
 * defeat this by making the accept() call nonblocking.
 */
int	my_accept (int s, SA *addr, socklen_t *addrlen)
{
	int	retval;

	set_non_blocking(s);
	if ((retval = accept(s, addr, addrlen)) < 0)
		syserr(-1, "my_accept: accept(%d) failed: %s", 
				s, strerror(errno));
	set_blocking(s);
	set_blocking(retval);		/* Just in case */
	return retval;
}

static int Connect (int fd, SA *addr)
{
	int	retval;

	set_non_blocking(fd);
	if ((retval = connect(fd, addr, socklen(addr))))
	{
	    if (errno != EINPROGRESS)
		syserr(-1, "Connect: connect(%d) failed: %s", fd, strerror(errno));
	    else
		retval = 0;
	}
	set_blocking(fd);
	return retval;
}

/*
 * XXX - Ugh!  Some getaddrinfo()s take AF_UNIX paths as the 'servname'
 * instead of as the 'nodename'.  How heinous!
 */
int	my_getaddrinfo (const char *nodename, const char *servname, const AI *hints, AI **res)
{
#ifdef GETADDRINFO_DOES_NOT_DO_AF_UNIX
	int	do_af_unix = 0;
	USA 	storage;
	AI *	results;
	int	len;

	if (nodename && strchr(nodename, '/'))
		do_af_unix = 1;
	if (hints && hints->ai_family == AF_UNIX)
		do_af_unix = 1;

	if (do_af_unix)
	{
                memset(&storage, 0, sizeof(storage));
                storage.sun_family = AF_UNIX;
                strlcpy(storage.sun_path, nodename, sizeof(storage.sun_path));
#ifdef HAVE_SA_LEN
# ifdef SUN_LEN
                storage.sun_len = SUN_LEN(&storage);
# else
                storage.sun_len = strlen(nodename) + 1;
# endif
#endif
                len = strlen(storage.sun_path) + 3;

		(*res) = new_malloc(sizeof(*results));
		(*res)->ai_flags = 0;
		(*res)->ai_family = AF_UNIX;
		(*res)->ai_socktype = SOCK_STREAM;
		(*res)->ai_protocol = 0;
		(*res)->ai_addrlen = len;
		(*res)->ai_canonname = malloc_strdup(nodename);
		(*res)->ai_addr = new_malloc(sizeof(storage));
		*(USA *)((*res)->ai_addr) = storage;
		(*res)->ai_next = 0;

                return 0;
	}
#endif

	/*
	 * XXX -- Support getaddrinfo()s that want an AF_UNIX path to
	 * be the second argument and not the first one.  Bleh.
	 */
	if ((nodename && strchr(nodename, '/')) || 
	    (hints && hints->ai_family == AF_UNIX))
		return getaddrinfo(NULL, nodename, hints, res);
	else
		return getaddrinfo(nodename, servname, hints, res);
}

void	my_freeaddrinfo (AI *ai)
{
#ifdef GETADDRINFO_DOES_NOT_DO_AF_UNIX
	if (ai->ai_family == AF_UNIX)
	{
		new_free(&ai->ai_canonname);
		new_free(&ai->ai_addr);
		new_free(&ai);
		return;
	}
#endif

	freeaddrinfo(ai);
}

static int	Getnameinfo(const SA *sa, socklen_t salen, char *host, size_t hostlen, char *serv, size_t servlen, int flags)
{
#ifdef GETADDRINFO_DOES_NOT_DO_AF_UNIX
	if (sa->sa_family == AF_UNIX) 
	{
		socklen_t	len;
		const USA *	usa = (const USA *)sa;

#ifdef HAVE_SA_LEN
                len = usa->sun_len;
#else
# ifdef SUN_LEN
		len = SUN_LEN(usa);
# else
		len = strlen(usa->sun_path);
# endif
#endif

		if (host && hostlen)
		{
		    if (hostlen <= len)
		    {
			memcpy(host, usa->sun_path, hostlen);
			host[hostlen - 1] = 0;
		    }
		    else
		    {
			memcpy(host, &usa->sun_path, len);
			host[len] = 0;
		    }
		}

		if (serv && servlen)
			*serv = 0;

                return 0;
	}
#endif

	if ((flags & GNI_INTEGER) && sa->sa_family == AF_INET) 
	{
		snprintf(host, hostlen, "%lu", 
			(unsigned long)ntohl(((const ISA *)sa)->sin_addr.s_addr));
		host = NULL;
		hostlen = 0;
	}

	flags = flags & ~(GNI_INTEGER);
	return getnameinfo(sa, salen, host, hostlen, serv, servlen, flags);
}

static socklen_t	socklen (SA *sockaddr)
{
	if (sockaddr->sa_family == AF_INET)
		return sizeof(ISA);
#ifdef INET6
	else if (sockaddr->sa_family == AF_INET6)
		return sizeof(ISA6);
#endif
	else if (sockaddr->sa_family == AF_UNIX)
		return strlen(((USA *)sockaddr)->sun_path) + 2;
	else
		return 0;
}

/* set's socket options */
int	Socket (int domain, int type, int protocol)
{
        int     opt = 1;
        int     optlen = sizeof(opt);
	int	s;
#ifndef NO_STRUCT_LINGER
        struct linger   lin;
#endif

	if ((s = socket(domain, type, protocol)) < 0)
	{
		syserr(-1, "Socket: socket(%d,%d,%d) failed: %s",
				domain, type, protocol, strerror(errno));
		return -1;
	}

#ifndef NO_STRUCT_LINGER
        lin.l_onoff = lin.l_linger = 0;
        setsockopt(s, SOL_SOCKET, SO_LINGER, (char *)&lin, optlen);
#endif

        setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&opt, optlen);
        opt = 1;
        setsockopt(s, SOL_SOCKET, SO_KEEPALIVE, (char *)&opt, optlen);
	return s;
}

pid_t	async_getaddrinfo (const char *nodename, const char *servname, const AI *hints, int fd)
{
	AI *results = NULL;
	ssize_t	err;

#ifdef ASYNC_DNS
	{
	/* XXX Letting /exec clean up after us is a hack. */
	pid_t	helper;
	if ((helper = fork()))
		return helper;
	}
#endif

        if ((err = my_getaddrinfo(nodename, servname, hints, &results)))
        {
		err = -labs(err);		/* Always a negative number */
		if (!write(fd, &err, sizeof(err))) 
			(void) 0;
		close(fd);
#ifdef ASYNC_DNS
		exit(0);
#else
		return 0;
#endif
        }

	if (!results)
	{
		err = 0;
		if (!write(fd, &err, sizeof(err))) 
			(void) 0;
		close(fd);
#ifdef ASYNC_DNS
		exit(0);
#else
		return 0;
#endif
        }

        marshall_getaddrinfo(fd, results);
        my_freeaddrinfo(results);
        close(fd);
#ifdef ASYNC_DNS
	exit(0);
#endif
	return 0;	/* XXX This function should be void */
}

void	marshall_getaddrinfo (int fd, AI *results)
{
	ssize_t	len, gah;
	ssize_t	alignment = sizeof(void *);
	AI 	*result, *copy;
	char 	*retval, *ptr;

	for (len = 0, result = results; result; result = result->ai_next)
	{
		len += sizeof(AI);
		len += result->ai_addrlen;
		if (result->ai_canonname)
			len += strlen(result->ai_canonname) + 1;
		while (len % alignment != 0)
			len++;
	}

	/* Why do I know I'm gonna regret this? */
	ptr = retval = new_malloc(len + 1);
	memset(retval, 0, len + 1);
	for (result = results; result; result = result->ai_next)
	{
		copy = (AI *)ptr;

		/* Copy over the AI */
		memcpy(copy, result, sizeof(AI));

		/* Copy over the ai_addr */
		ptr += sizeof(AI);
		memcpy(ptr, result->ai_addr, result->ai_addrlen);

		/* Point the AI at the ai_addr */
		copy->ai_addr = (SA *)ptr;

		/* Copy over the canonname */
		/* Point the AI at the canonname */
		ptr += result->ai_addrlen;
		if (result->ai_canonname)
		{
		    gah = strlen(result->ai_canonname) + 1;
		    memcpy(ptr, result->ai_canonname, gah);
		    copy->ai_canonname = ptr;
		    ptr += gah;
		}
		else
		    copy->ai_canonname = NULL;

		 /* Calculate the start of the next entry */
		 while ((intptr_t)ptr % alignment != 0)
			ptr++;

		/* Point the AI at the next entry */
		if (result->ai_next)
			copy->ai_next = (AI *)ptr;
		else
			copy->ai_next = NULL;
	}

	if (!write(fd, (void *)&len, sizeof(len))) 
		(void) 0;
	if (!write(fd, (void *)retval, len)) 
		(void) 0;
	new_free(&retval);
}

void	unmarshall_getaddrinfo (AI *results)
{
	ssize_t	len;
	AI 	*result;
	char 	*ptr;
	ssize_t	alignment = sizeof(void *);

	/* Why do I know I'm gonna regret this? */
	for (result = results; result; result = result->ai_next)
	{
		ptr = (char *)result;

		/* Copy over the ai_addr */
		ptr += sizeof(AI);
		result->ai_addr = (SA *)ptr;
		ptr += result->ai_addrlen;

		if (result->ai_canonname)
		{
		    result->ai_canonname = ptr;
		    len = strlen(result->ai_canonname) + 1;
		    ptr += len;
		}

		 /* Calculate the start of the next entry */
		 while ((intptr_t)ptr % alignment != 0)
			ptr++;

		/* Point the AI at the next entry */
		if (result->ai_next)
			result->ai_next = (AI *)ptr;
	}
}

