/*

Copyright 1988, 1998  The Open Group
Copyright 2000-2004 Oswald Buddenhagen <ossi@kde.org>

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of a copyright holder shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from the copyright holder.

*/

/*
 * xdm - display manager daemon
 * Author: Keith Packard, MIT X Consortium
 *
 * maintain the authorization generation daemon
 */

#include "dm.h"
#include "dm_auth.h"
#include "dm_error.h"

#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#ifdef __OpenBSD__
#include <pwd.h>
#endif

#include <sys/ioctl.h>

#include "dm_socket.h"
#ifdef DNETCONN
# include <netdnet/dnetdb.h>
#endif

#if (defined(_POSIX_SOURCE) && !defined(_AIX) && !defined(__QNX__)) || defined(__hpux) || defined(__svr4__) /* XXX */
# define NEED_UTSNAME
# include <sys/utsname.h>
#endif

#ifdef __GNU__
# include <netdb.h>
# undef SIOCGIFCONF
#else /* __GNU__ */
# include <net/if.h>
# ifdef __svr4__
#  include <netdb.h>
#  include <sys/sockio.h>
#  include <sys/stropts.h>
# endif
# ifdef __EMX__
#  define link rename
#  define chown(a,b,c)
#  include <io.h>
# endif
#endif /* __GNU__ */

#include <X11/Xlib.h>

struct AuthProtocol {
	unsigned short name_length;
	const char *name;
	void (*InitAuth)( unsigned short len, const char *name );
	Xauth *(*GetAuth)( unsigned short len, const char *name );
#ifdef XDMCP
	void (*GetXdmcpAuth)( struct protoDisplay *pdpy,
	                      unsigned short authorizationNameLen,
	                      const char *authorizationName );
#endif
	int inited;
};

#ifdef XDMCP
# define xdmcpauth(arg) , arg
#else
# define xdmcpauth(arg)
#endif

static struct AuthProtocol authProtocols[] = {
{ (unsigned short)18, "MIT-MAGIC-COOKIE-1",
	mitInitAuth, mitGetAuth xdmcpauth(NULL), False
},
#ifdef HASXDMAUTH
{ (unsigned short)19, "XDM-AUTHORIZATION-1",
	xdmInitAuth, xdmGetAuth xdmcpauth(xdmGetXdmcpAuth), False
},
#endif
#ifdef SECURE_RPC
{ (unsigned short)9, "SUN-DES-1",
	secureRPCInitAuth, secureRPCGetAuth xdmcpauth(NULL), False
},
#endif
#ifdef K5AUTH
{ (unsigned short)14, "MIT-KERBEROS-5",
	krb5InitAuth, krb5GetAuth xdmcpauth(NULL), False
},
#endif
};

static struct AuthProtocol *
findProtocol( unsigned short name_length, const char *name )
{
	unsigned i;

	for (i = 0; i < as(authProtocols); i++)
		if (authProtocols[i].name_length == name_length &&
		    memcmp( authProtocols[i].name, name, name_length ) == 0)
		{
			return &authProtocols[i];
		}
	return (struct AuthProtocol *)0;
}

int
validAuthorization( unsigned short name_length, const char *name )
{
	if (findProtocol( name_length, name ))
		return True;
	return False;
}

static Xauth *
generateAuthorization( unsigned short name_length, const char *name )
{
	struct AuthProtocol *a;
	Xauth *auth = 0;

	debug( "generateAuthorization %s\n", name );
	if ((a = findProtocol( name_length, name ))) {
		if (!a->inited) {
			(*a->InitAuth)( name_length, name );
			a->inited = True;
		}
		auth = (*a->GetAuth)( name_length, name );
		if (auth) {
			debug( "got %p (%d %.*s) %02[*hhx\n", auth,
			       auth->name_length, auth->name_length, auth->name,
			       auth->data_length, auth->data );
		} else
			debug( "got (null)\n" );
	} else
		debug( "unknown authorization %s\n", name );
	return auth;
}

#ifdef XDMCP

void
setProtoDisplayAuthorization( struct protoDisplay *pdpy,
                              unsigned short authorizationNameLen,
                              const char *authorizationName )
{
	struct AuthProtocol *a;
	Xauth *auth;

	a = findProtocol( authorizationNameLen, authorizationName );
	pdpy->xdmcpAuthorization = pdpy->fileAuthorization = 0;
	if (a) {
		if (!a->inited) {
			(*a->InitAuth)( authorizationNameLen, authorizationName );
			a->inited = True;
		}
		if (a->GetXdmcpAuth) {
			(*a->GetXdmcpAuth)( pdpy, authorizationNameLen, authorizationName );
			auth = pdpy->xdmcpAuthorization;
		} else {
			auth = (*a->GetAuth)( authorizationNameLen, authorizationName );
			pdpy->fileAuthorization = auth;
			pdpy->xdmcpAuthorization = 0;
		}
		if (auth)
			debug( "got %p (%d %.*s)\n", auth,
			       auth->name_length, auth->name_length, auth->name );
		else
			debug( "got (null)\n" );
	}
}

#endif /* XDMCP */

void
cleanUpFileName( const char *src, char *dst, int len )
{
	while (*src) {
		if (--len <= 0)
				break;
		switch (*src & 0x7f) {
		case '/':
			*dst++ = '_';
			break;
		case '-':
			*dst++ = '.';
			break;
		default:
			*dst++ = (*src & 0x7f);
		}
		++src;
	}
	*dst = '\0';
}


static FILE *
fdOpenW( int fd )
{
	FILE *f;

	if (fd >= 0) {
		if ((f = fdopen( fd, "w" )))
			return f;
		close( fd );
	}
	return 0;
}


#define NAMELEN 255

static FILE *
makeServerAuthFile( struct display *d )
{
	FILE *f;
#ifndef HAVE_MKSTEMP
	int r;
#endif
	char cleanname[NAMELEN], nambuf[NAMELEN+128];

	/*
	 * Some paranoid, but still not sufficient (DoS was still possible)
	 * checks used to be here. I removed all this stuff because
	 * a) authDir is supposed to be /var/run/xauth (=safe) or similar and
	 * b) even if it's not (say, /tmp), we create files safely (hopefully).
	 */
	if (mkdir( authDir, 0755 ) < 0  &&  errno != EEXIST)
		return 0;
	cleanUpFileName( d->name, cleanname, NAMELEN - 8 );
#ifdef HAVE_MKSTEMP
	sprintf( nambuf, "%s/A%s-XXXXXX", authDir, cleanname );
	if ((f = fdOpenW( mkstemp( nambuf ) ))) {
		strDup( &d->authFile, nambuf );
		return f;
	}
#else
	for (r = 0; r < 100; r++) {
		sprintf( nambuf, "%s/A%s-XXXXXX", authDir, cleanname );
		(void)mktemp( nambuf );
		if ((f = fdOpenW( open( nambuf, O_WRONLY | O_CREAT | O_EXCL, 0600 ) ))) {
			strDup( &d->authFile, nambuf );
			return f;
		}
	}
#endif
	return 0;
}

int
saveServerAuthorizations( struct display *d, Xauth **auths, int count )
{
	FILE *auth_file;
	int i;
#ifdef __OpenBSD__
	struct passwd *x11;
#endif

	if (!d->authFile && d->clientAuthFile && *d->clientAuthFile)
		strDup( &d->authFile, d->clientAuthFile );
	if (d->authFile) {
		if (!(auth_file = fdOpenW( creat( d->authFile, 0600 ) ))) {
			logError( "Cannot open X server authorization file %s\n", d->authFile );
			free( d->authFile );
			d->authFile = NULL;
			return False;
		}
	} else {
		if (!(auth_file = makeServerAuthFile( d ))) {
			logError( "Cannot create X server authorization file\n" );
			return False;
		}
	}
#ifdef __OpenBSD__
	/* Give read capability to group _x11 */
	if (!(x11 = getpwnam( "_x11" )))
		logError( "Cannot find _x11 user\n" );
	else
		fchown( fileno( auth_file ), x11->pw_uid, x11->pw_gid );
	endpwent();
#endif
	debug( "file: %s  auth: %p\n", d->authFile, auths );
	for (i = 0; i < count; i++) {
		/*
		 * User-based auths may not have data until
		 * a user logs in.  In which case don't write
		 * to the auth file so xrdb and setup programs don't fail.
		 */
		if (auths[i]->data_length > 0)
			if (!XauWriteAuth( auth_file, auths[i] ) ||
			    fflush( auth_file ) == EOF)
			{
				fclose( auth_file );
				logError( "Cannot write X server authorization file %s\n",
				          d->authFile );
				free( d->authFile );
				d->authFile = NULL;
				return False;
			}
	}
	fclose( auth_file );
	return True;
}

void
setLocalAuthorization( struct display *d )
{
	Xauth *auth, **auths;
	int i, j;

	if (d->authorizations)
	{
		for (i = 0; i < d->authNum; i++)
			XauDisposeAuth( d->authorizations[i] );
		free( (char *)d->authorizations );
		d->authorizations = (Xauth **)NULL;
		d->authNum = 0;
	}
	debug( "setLocalAuthorization %s, auths %[s\n", d->name, d->authNames );
	if (!d->authNames)
		return;
	for (i = 0; d->authNames[i]; i++)
		;
	d->authNameNum = i;
	if (d->authNameLens)
		free( (char *)d->authNameLens );
	d->authNameLens = (unsigned short *)Malloc( d->authNameNum * sizeof(unsigned short) );
	if (!d->authNameLens)
		return;
	for (i = 0; i < d->authNameNum; i++)
		d->authNameLens[i] = strlen( d->authNames[i] );
	auths = (Xauth **)Malloc( d->authNameNum * sizeof(Xauth *) );
	if (!auths)
		return;
	j = 0;
	for (i = 0; i < d->authNameNum; i++) {
		auth = generateAuthorization( d->authNameLens[i], d->authNames[i] );
		if (auth)
			auths[j++] = auth;
	}
	if (saveServerAuthorizations( d, auths, j )) {
		d->authorizations = auths;
		d->authNum = j;
	} else {
		for (i = 0; i < j; i++)
			XauDisposeAuth( auths[i] );
		free( (char *)auths );
	}
}

/*
 * Set the authorization to use for xdm's initial connection
 * to the X server.  Cannot use user-based authorizations
 * because no one has logged in yet, so we don't have any
 * user credentials.
 * Well, actually we could use SUN-DES-1 because we tell the server
 * to allow root in.  This is bogus and should be fixed.
 */
void
setAuthorization( struct display *d )
{
	register Xauth **auth = d->authorizations;
	int i;

	for (i = 0; i < d->authNum; i++) {
		if (auth[i]->name_length == 9 &&
		    memcmp( auth[i]->name, "SUN-DES-1", 9 ) == 0)
			continue;
		if (auth[i]->name_length == 14 &&
		    memcmp( auth[i]->name, "MIT-KERBEROS-5", 14 ) == 0)
			continue;
		XSetAuthorization( auth[i]->name, (int)auth[i]->name_length,
		                   auth[i]->data, (int)auth[i]->data_length );
	}
}

static int
openFiles( const char *name, char *new_name, FILE **oldp, FILE **newp )
{
	strcat( strcpy( new_name, name ), "-n" );
	if (!(*newp =
	      fdOpenW( creat( new_name, 0600 ) ))) {
		debug( "cannot open new file %s\n", new_name );
		return False;
	}
	*oldp = fopen( name, "r" );
	debug( "opens succeeded %s %s\n", name, new_name );
	return True;
}

struct addrList {
	struct addrList *next;
	unsigned short family, address_length, number_length;
	char data[1];
};

static struct addrList *addrs;

static void
initAddrs( void )
{
	addrs = 0;
}

static void
doneAddrs( void )
{
	struct addrList *a, *n;
	for (a = addrs; a; a = n) {
		n = a->next;
		free( a );
	}
}

static void
saveEntry( Xauth *auth )
{
	struct addrList *new;

	if (!(new = Malloc( offsetof(struct addrList, data) +
	                    auth->address_length + auth->number_length )))
		return;
	new->address_length = auth->address_length;
	new->number_length = auth->number_length;
	memcpy( new->data, auth->address, (int)auth->address_length );
	memcpy( new->data + (int)auth->address_length,
	        auth->number, (int)auth->number_length );
	new->family = auth->family;
	new->next = addrs;
	addrs = new;
}

static int
checkEntry( Xauth *auth )
{
	struct addrList *a;

	for (a = addrs; a; a = a->next)
		if (a->family == auth->family &&
		    a->address_length == auth->address_length &&
		    !memcmp( a->data, auth->address, auth->address_length ) &&
		    a->number_length == auth->number_length &&
		    !memcmp( a->data + a->address_length,
		             auth->number, auth->number_length ))
			return True;
	return False;
}

static void
writeAuth( FILE *file, Xauth *auth, int *ok )
{
	if (debugLevel & DEBUG_AUTH) /* normally too verbose */
		debug( "writeAuth: doWrite = %d\n"
		       "family: %d\n"
		       "addr:    %02[*:hhx\n"
		       "number:  %02[*:hhx\n"
		       "name:    %02[*:hhx\n"
		       "data:    %02[*:hhx\n",
		       ok, auth->family,
		       auth->address_length, auth->address,
		       auth->number_length, auth->number,
		       auth->name_length, auth->name,
		       auth->data_length, auth->data );
	if (ok && !XauWriteAuth( file, auth ))
		*ok = False;
}

static void
writeAddr( int family, int addr_length, CARD8 *addr,
           FILE *file, Xauth *auth, int *ok )
{
	auth->family = (unsigned short)family;
	auth->address_length = addr_length;
	auth->address = (char *)addr;
	debug( "writeAddr: writing and saving an entry\n" );
	writeAuth( file, auth, ok );
	if (!checkEntry( auth ))
		saveEntry( auth );
}

static void
defineLocal( FILE *file, Xauth *auth, int *ok )
{
#if !defined(NEED_UTSNAME) || defined(__hpux)
	char displayname[100];
#endif
#ifdef NEED_UTSNAME
	struct utsname name;
#endif

	/* stolen from xinit.c */

/* Make sure this produces the same string as _XGetHostname in lib/X/XlibInt.c.
 * Otherwise, Xau will not be able to find your cookies in the Xauthority file.
 *
 * Note: POSIX says that the ``nodename'' member of utsname does _not_ have
 *       to have sufficient information for interfacing to the network,
 *       and so, you may be better off using gethostname (if it exists).
 */

#ifdef NEED_UTSNAME

	/* hpux:
	 * Why not use gethostname()?  Well, at least on my system, I've had to
	 * make an ugly kernel patch to get a name longer than 8 characters, and
	 * uname() lets me access to the whole string (it smashes release, you
	 * see), whereas gethostname() kindly truncates it for me.
	 */
	uname( &name );
	writeAddr( FamilyLocal, strlen( name.nodename ), (CARD8 *)name.nodename,
	           file, auth, ok );
#endif

#if !defined(NEED_UTSNAME) || defined(__hpux)
	/* _AIX:
	 * In _AIX, _POSIX_SOURCE is defined, but uname gives only first
	 * field of hostname. Thus, we use gethostname instead.
	 */

	/*
	 * For HP-UX, HP's Xlib expects a fully-qualified domain name, which
	 * is achieved by using gethostname().  For compatibility, we must
	 * also still create the entry using uname() above.
	 */
	displayname[0] = 0;
	if (!gethostname( displayname, sizeof(displayname) ))
		displayname[sizeof(displayname) - 1] = 0;

# ifdef NEED_UTSNAME
	/*
	 * If gethostname and uname both returned the same name,
	 * do not write a duplicate entry.
	 */
	if (strcmp( displayname, name.nodename ))
# endif
		writeAddr( FamilyLocal, strlen( displayname ), (CARD8 *)displayname,
		           file, auth, ok );
#endif
}

#ifdef SYSV_SIOCGIFCONF

/* Deal with different SIOCGIFCONF ioctl semantics on SYSV, SVR4 */

int
ifioctl( int fd, int cmd, char *arg )
{
	struct strioctl ioc;
	int ret;

	bzero( (char *)&ioc, sizeof(ioc) );
	ioc.ic_cmd = cmd;
	ioc.ic_timout = 0;
	if (cmd == SIOCGIFCONF) {
		ioc.ic_len = ((struct ifconf *)arg)->ifc_len;
		ioc.ic_dp = ((struct ifconf *)arg)->ifc_buf;
	} else {
		ioc.ic_len = sizeof(struct ifreq);
		ioc.ic_dp = arg;
	}
	ret = ioctl( fd, I_STR, (char *)&ioc );
	if (ret >= 0 && cmd == SIOCGIFCONF)
		((struct ifconf *)arg)->ifc_len = ioc.ic_len;
	return (ret);
}

#endif /* SYSV_SIOCGIFCONF */

#ifdef HAVE_GETIFADDRS
# include <ifaddrs.h>

static void
defineSelf( FILE *file, Xauth *auth, int *ok )
{
	struct ifaddrs *ifap, *ifr;
	CARD8 *addr;
	int family, len;

	if (getifaddrs( &ifap ) < 0)
		return;
	for (ifr = ifap; ifr; ifr = ifr->ifa_next) {
		if (!ifr->ifa_addr)
			continue;
		family = convertAddr( (char *)(ifr->ifa_addr), &len, &addr );
		if (family == -1 || family == FamilyLocal)
			continue;
		/*
		 * don't write out 'localhost' entries, as
		 * they may conflict with other local entries.
		 * defineLocal will always be called to add
		 * the local entry anyway, so this one can
		 * be tossed.
		 */
		if (family == FamilyInternet &&
		    addr[0] == 127 && addr[1] == 0 && addr[2] == 0 && addr[3] == 1)
		{
			debug( "Skipping localhost address\n" );
			continue;
		}
# if defined(IPv6) && defined(AF_INET6)
		if (family == FamilyInternet6) {
			if (IN6_IS_ADDR_LOOPBACK( ((struct in6_addr *)addr) )) {
				debug( "Skipping IPv6 localhost address\n" );
				continue;
			}
			/* Also skip XDM-AUTHORIZATION-1 */
			if (auth->name_length == 19 &&
			    !memcmp( auth->name, "XDM-AUTHORIZATION-1", 19 )) {
				debug( "Skipping IPv6 XDM-AUTHORIZATION-1\n" );
				continue;
			}
		}
# endif
		writeAddr( family, len, addr, file, auth, ok );
	}
	freeifaddrs( ifap );
}
#else  /* GETIFADDRS */

#if defined(STREAMSCONN) && !defined(SYSV_SIOCGIFCONF) && !defined(WINTCP)

#include <tiuser.h>

/* Define this host for access control.  Find all the hosts the OS knows about
 * for this fd and add them to the selfhosts list.
 * TLI version, written without sufficient documentation.
 */
static void
defineSelf( int fd, FILE *file, Xauth *auth, int *ok )
{
	struct netbuf netb;
	char addrret[1024]; /* easier than t_alloc */

	netb.maxlen = sizeof(addrret);
	netb.buf = addrret;
	if (t_getname( fd, &netb, LOCALNAME ) == -1)
		t_error( "t_getname" );
	/* what a kludge */
	writeAddr( FamilyInternet, 4, (CARD8 *)netb.buf+4, file, auth, ok );
}

#else

#ifdef WINTCP /* NCR with Wollongong TCP */

#include <stropts.h>
#include <tiuser.h>

#include <sys/stream.h>
#include <net/if.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/in.h>
#include <netinet/in_var.h>

static void
defineSelf( int fd, FILE *file, Xauth *auth, int *ok )
{
	/*
	 * The Wollongong drivers used by NCR SVR4/MP-RAS don't understand the
	 * socket IO calls that most other drivers seem to like. Because of
	 * this, this routine must be special cased for NCR. Eventually,
	 * this will be cleared up.
	 */

	struct ipb ifnet;
	struct in_ifaddr ifaddr;
	struct strioctl str;
	int len, ipfd;

	if ((ipfd = open( "/dev/ip", O_RDWR, 0 )) < 0) {
		logError( "Trouble getting interface configuration\n" );
		return;
	}

	/* Indicate that we want to start at the beginning */
	ifnet.ib_next = (struct ipb *)1;

	while (ifnet.ib_next) {
		str.ic_cmd = IPIOC_GETIPB;
		str.ic_timout = 0;
		str.ic_len = sizeof(struct ipb);
		str.ic_dp = (char *)&ifnet;

		if (ioctl( ipfd, (int)I_STR, (char *)&str ) < 0) {
			close( ipfd );
			logError( "Trouble getting interface configuration\n" );
			return;
		}

		ifaddr.ia_next = (struct in_ifaddr *)ifnet.if_addrlist;
		str.ic_cmd = IPIOC_GETINADDR;
		str.ic_timout = 0;
		str.ic_len = sizeof(struct in_ifaddr);
		str.ic_dp = (char *)&ifaddr;

		if (ioctl( ipfd, (int)I_STR, (char *)&str ) < 0) {
			close( ipfd );
			logError( "Trouble getting interface configuration\n" );
			return;
		}

		/*
		 * Ignore the 127.0.0.1 entry.
		 */
		if (IA_SIN( &ifaddr )->sin_addr.s_addr == htonl( 0x7f000001 ))
			continue;

		writeAddr( FamilyInternet, 4, (CARD8 *)&(IA_SIN( &ifaddr )->sin_addr),
		           file, auth, ok );

	}
	close( ipfd );
}

#else /* WINTCP */

/* Solaris provides an extended interface SIOCGLIFCONF.  Other systems
 * may have this as well, but the code has only been tested on Solaris
 * so far, so we only enable it there.  Other platforms may be added as
 * needed.
 *
 * Test for Solaris commented out  --  TSI @ UQV 2003.06.13
 */
#ifdef SIOCGLIFCONF
/* #if defined(sun) */
# define USE_SIOCGLIFCONF
/* #endif */
#endif

#if defined(SIOCGIFCONF) || defined (USE_SIOCGLIFCONF)

#if !defined(SYSV_SIOCGIFCONF) || defined(USE_SIOCGLIFCONF)
# define ifioctl ioctl
#endif

#ifdef USE_SIOCGLIFCONF
# define ifr_type struct lifreq
#else
# define ifr_type struct ifreq
#endif

/* Handle variable length ifreq in BNR2 and later */
#ifdef VARIABLE_IFREQ
# define ifr_size(p) (sizeof(struct ifreq) + \
                      (p->ifr_addr.sa_len > sizeof(p->ifr_addr) ? \
                       p->ifr_addr.sa_len - sizeof(p->ifr_addr) : 0))
#else
# define ifr_size(p) (sizeof(ifr_type))
#endif

#ifdef USE_SIOCGLIFCONF
# define IFC_IOCTL_REQ SIOCGLIFCONF
# define IFC_REQ(ifc) ifc.lifc_req
# define IFC_LEN(ifc) ifc.lifc_len
# define IFR_ADDR(ifr) ifr->lifr_addr
# define IFR_NAME(ifr) ifr->lifr_name
#else
# define IFC_IOCTL_REQ SIOCGIFCONF
# define IFC_REQ(ifc) ifc.ifc_req
# define IFC_LEN(ifc) ifc.ifc_len
# define IFR_ADDR(ifr) ifr->ifr_addr
# define IFR_NAME(ifr) ifr->ifr_name
#endif

/* Define this host for access control.  Find all the hosts the OS knows about
 * for this fd and add them to the selfhosts list.
 */
static void
defineSelf( int fd, FILE *file, Xauth *auth, int *ok )
{
	char buf[2048], *cp, *cplim;
	int len;
	CARD8 *addr;
	int family;
	ifr_type *ifr;
#ifdef USE_SIOCGLIFCONF
	int n;
	void * bufptr = buf;
	size_t buflen = sizeof(buf);
	struct lifconf ifc;
# ifdef SIOCGLIFNUM
	struct lifnum ifn;
# endif
#else
	struct ifconf ifc;
#endif

#if defined(SIOCGLIFNUM) && defined(SIOCGLIFCONF)
	ifn.lifn_family = AF_UNSPEC;
	ifn.lifn_flags = 0;
	if (ioctl( fd, (int)SIOCGLIFNUM, (char *)&ifn ) < 0)
		logError( "Failed getting interface count\n" );
	if (buflen < (ifn.lifn_count * sizeof(struct lifreq))) {
		buflen = ifn.lifn_count * sizeof(struct lifreq);
		bufptr = Malloc( buflen );
	}
#endif

#ifdef USE_SIOCGLIFCONF
	ifc.lifc_family = AF_UNSPEC;
	ifc.lifc_flags = 0;
	ifc.lifc_len = buflen;
	ifc.lifc_buf = bufptr;
#else
	ifc.ifc_len = sizeof(buf);
	ifc.ifc_buf = buf;
#endif
	if (ifioctl (fd, IFC_IOCTL_REQ, (char *)&ifc) < 0) {
		logError( "Trouble getting network interface configuration\n" );
#if defined(SIOCGLIFNUM) && defined(SIOCGLIFCONF)
		if (bufptr != buf)
			free( bufptr );
#endif
		return;
	}

	cplim = (char *)IFC_REQ( ifc ) + IFC_LEN( ifc );

	for (cp = (char *)IFC_REQ( ifc ); cp < cplim; cp += ifr_size (ifr)) {
		ifr = (ifr_type *) cp;
#ifdef DNETCONN
		/*
		 * this is ugly but SIOCGIFCONF returns decnet addresses in
		 * a different form from other decnet calls
		 */
		if (IFR_ADDR( ifr ).sa_family == AF_DECnet) {
				len = sizeof(struct dn_naddr);
				addr = (CARD8 *)IFR_ADDR( ifr ).sa_data;
				family = FamilyDECnet;
		} else
#endif
		{
			family = convertAddr( (char *)&IFR_ADDR( ifr ), &len, &addr );
			if (family < 0)
				continue;

			if (len == 0) {
				debug( "skipping zero length address\n" );
				continue;
			}
			/*
			 * don't write out 'localhost' entries, as
			 * they may conflict with other local entries.
			 * defineLocal will always be called to add
			 * the local entry anyway, so this one can
			 * be tossed.
			 */
			if (family == FamilyInternet &&
			    addr[0] == 127 && addr[1] == 0 &&
			    addr[2] == 0 && addr[3] == 1)
			{
					debug( "skipping localhost address\n" );
					continue;
			}
#if defined(IPv6) && defined(AF_INET6)
			if (family == FamilyInternet6) {
				if (IN6_IS_ADDR_LOOPBACK( ((struct in6_addr *)addr) )) {
					debug( "Skipping IPv6 localhost address\n" );
					continue;
				}
				/* Also skip XDM-AUTHORIZATION-1 */
				if (auth->name_length == 19 &&
				    !memcmp( auth->name, "XDM-AUTHORIZATION-1", 19 )) {
					debug( "Skipping IPv6 XDM-AUTHORIZATION-1\n" );
					continue;
				}
			}
#endif
		}
		debug( "defineSelf: write network address, length %d\n", len );
		writeAddr( family, len, addr, file, auth, ok );
	}
#if defined(SIOCGLIFNUM) && defined(SIOCGLIFCONF)
	if (bufptr != buf)
		free( bufptr );
#endif
}

#else /* SIOCGIFCONF */

/* Define this host for access control.  Find all the hosts the OS knows about
 * for this fd and add them to the selfhosts list.
 */
static void
defineSelf( int fd, int file, int auth, int *ok )
{
	int len;
	CARD8 *addr;
	int family;

	struct utsname name;
	register struct hostent  *hp;

	union {
		struct sockaddr   sa;
		struct sockaddr_in  in;
	} saddr;

	struct sockaddr_in *inetaddr;

	/* hpux:
	 * Why not use gethostname()?  Well, at least on my system, I've had to
	 * make an ugly kernel patch to get a name longer than 8 characters, and
	 * uname() lets me access to the whole string (it smashes release, you
	 * see), whereas gethostname() kindly truncates it for me.
	 */
	uname( &name );
	if ((hp = gethostbyname( name.nodename ))) {
		saddr.sa.sa_family = hp->h_addrtype;
		inetaddr = (struct sockaddr_in *)(&(saddr.sa));
		memmove( (char *)&(inetaddr->sin_addr), (char *)hp->h_addr,
		         (int)hp->h_length );
		if ((family = convertAddr( &(saddr.sa), &len, &addr )) >= 0)
			writeAddr( FamilyInternet, sizeof(inetaddr->sin_addr),
			           (CARD8 *)(&inetaddr->sin_addr), file, auth, ok );
	}
}

#endif /* SIOCGIFCONF else */
#endif /* WINTCP else */
#endif /* STREAMSCONN && !SYSV_SIOCGIFCONF else */
#endif /* HAVE_GETIFADDRS */

static void
setAuthNumber( Xauth *auth, const char *name )
{
	char *colon;
	char *dot;

	debug( "setAuthNumber %s\n", name );
	colon = strrchr( name, ':' );
	if (colon) {
		++colon;
		dot = strchr( colon, '.' );
		if (dot)
			auth->number_length = dot - colon;
		else
			auth->number_length = strlen( colon );
		if (!strNDup( &auth->number, colon, auth->number_length ))
			auth->number_length = 0;
		debug( "setAuthNumber: %s\n", auth->number );
	}
}

static void
writeLocalAuth( FILE *file, Xauth *auth, const char *name, int *ok )
{
#if defined(STREAMSCONN) || !defined(HAVE_GETIFADDRS)
	int fd;
#endif

	debug( "writeLocalAuth: %s %.*s\n", name, auth->name_length, auth->name );
	setAuthNumber( auth, name );
# ifdef STREAMSCONN
	fd = t_open( "/dev/tcp", O_RDWR, 0 );
	t_bind( fd, NULL, NULL );
	defineSelf( fd, file, auth, ok );
	t_unbind( fd );
	t_close( fd );
# elif defined(HAVE_GETIFADDRS)
	defineSelf( file, auth, ok );
# else
#  ifdef TCPCONN
#   if defined(IPv6) && defined(AF_INET6)
	fd = socket( AF_INET6, SOCK_STREAM, 0 );
	if (fd < 0)
#   endif
	fd = socket( AF_INET, SOCK_STREAM, 0 );
	defineSelf( fd, file, auth, ok );
	close( fd );
#  endif
#  ifdef DNETCONN
	fd = socket( AF_DECnet, SOCK_STREAM, 0 );
	defineSelf( fd, file, auth, ok );
	close( fd );
#  endif
# endif /* HAVE_GETIFADDRS */
	defineLocal( file, auth, ok );
}

#ifdef XDMCP

/*
 * Call convertAddr(), and if it returns an IPv4 localhost, convert it
 * to a local display name.  Meets the _XTransconvertAddress's localhost
 * hack.
 */

static int
convertAuthAddr( char *saddr, int *len, CARD8 **addr )
{
	int ret = convertAddr( saddr, len, addr );
	if (ret == FamilyInternet &&
	    ((struct in_addr *)*addr)->s_addr == htonl( 0x7F000001L ))
		ret = FamilyLocal;
	return ret;
}

static void
writeRemoteAuth( FILE *file, Xauth *auth, XdmcpNetaddr peer, int peerlen,
                 const char *name, int *ok )
{
	int family = FamilyLocal;
	CARD8 *addr;

	debug( "writeRemoteAuth: %s %.*s\n", name, auth->name_length, auth->name );
	if (!peer || peerlen < 2)
		return;
	setAuthNumber( auth, name );
	family = convertAuthAddr( peer, &peerlen, &addr );
	debug( "writeRemoteAuth: family %d\n", family );
	if (family != FamilyLocal) {
		debug( "writeRemoteAuth: %d, %02[*:hhx\n",
		       family, peerlen, addr );
		writeAddr( family, peerlen, addr, file, auth, ok );
	} else
		writeLocalAuth( file, auth, name, ok );
}

#endif /* XDMCP */

#define NBSIZE 1024

static void
startUserAuth( char *buf, char *nbuf, FILE **old, FILE **new )
{
	const char *home;
	int lockStatus;

	initAddrs();
	*new = 0;
	if ((home = getEnv( userEnviron, "HOME" )) && strlen( home ) < NBSIZE - 12) {
		sprintf( buf, "%s/.Xauthority", home );
		debug( "XauLockAuth %s\n", buf );
		lockStatus = XauLockAuth( buf, 1, 2, 10 );
		debug( "lock is %d\n", lockStatus );
		if (lockStatus == LOCK_SUCCESS)
			if (!openFiles( buf, nbuf, old, new ))
				XauUnlockAuth( buf );
	}
	if (!*new)
		logWarn( "Cannot update authorization file in home dir %s\n", home );
}

static int
endUserAuth( FILE *old, FILE *new, const char *nname, int ok )
{
	Xauth *entry;
	struct stat statb;

	if (old) {
		if (fstat( fileno( old ), &statb ) != -1)
			chmod( nname, (int)(statb.st_mode & 0777) );
		/*SUPPRESS 560*/
		while ((entry = XauReadAuth( old ))) {
			if (!checkEntry( entry )) {
				debug( "writing an entry\n" );
				writeAuth( new, entry, &ok );
			}
			XauDisposeAuth( entry );
		}
		fclose( old );
	}
	if (fclose( new ) == EOF)
		ok = False;
	doneAddrs();
	return ok;
}

static void
undoUserAuth( const char *name, const char *new_name )
{
	logWarn( "Cannot save user authorization in home dir\n" );
	unlink( new_name );
	XauUnlockAuth( name );
}

static char *
moveUserAuth( const char *name, char *new_name, char *envname )
{
	if (unlink( name ))
		debug( "unlink %s failed\n", name );
	if (link( new_name, name )) {
		debug( "link failed %s %s\n", new_name, name );
		logError( "Cannot move user authorization into place\n" );
		envname = new_name;
	} else {
		debug( "new authorization moved into place\n" );
		unlink( new_name );
	}
	XauUnlockAuth( name );
	return envname;
}

void
setUserAuthorization( struct display *d )
{
	FILE *old, *new;
	char *name;
	char *envname;
	Xauth **auths;
	int i, ok;
	int magicCookie;
	int data_len;
	char name_buf[NBSIZE], new_name[NBSIZE + 2];

	debug( "setUserAuthorization\n" );
	auths = d->authorizations;
	if (auths) {
		if (d->forceUserAuthDir)
			goto fallback;
		startUserAuth( name_buf, new_name, &old, &new );
		if (new) {
			envname = 0;
			name = name_buf;
		} else {
			/* 'old' is uninitialized here */
		  fallback:

			if (strlen( d->userAuthDir ) >= NBSIZE - 13)
				return;
			/*
			 * Note, that we don't lock the auth file here, as it's
			 * temporary - we can assume, that we are the only ones
			 * knowing about this file anyway.
			 */
#ifdef HAVE_MKSTEMP
			sprintf( name_buf, "%s/.XauthXXXXXX", d->userAuthDir );
			new = fdOpenW( mkstemp( name_buf ) );
#else
			for (i = 0; i < 100; i++) {
				sprintf( name_buf, "%s/.XauthXXXXXX", d->userAuthDir );
				(void)mktemp( name_buf );
				if ((new =
				     fdOpenW( open( name_buf, O_WRONLY | O_CREAT | O_EXCL,
				                    0600 ) )))
					break;
			}
#endif
			if (!new) {
				logError( "Cannot create authorization file in %s\n",
				          d->userAuthDir );
				return;
			}
			name = 0;
			envname = name_buf;
			old = 0;
		}
		ok = True;
		debug( "%d authorization protocols for %s\n", d->authNum, d->name );
		/*
		 * Write MIT-MAGIC-COOKIE-1 authorization first, so that
		 * R4 clients which only knew that, and used the first
		 * matching entry will continue to function
		 */
		magicCookie = -1;
		for (i = 0; i < d->authNum; i++) {
			if (auths[i]->name_length == 18 &&
			    !memcmp( auths[i]->name, "MIT-MAGIC-COOKIE-1", 18 ))
			{
				magicCookie = i;
				if ((d->displayType & d_location) == dLocal)
					writeLocalAuth( new, auths[i], d->name, &ok );
#ifdef XDMCP
				else
					writeRemoteAuth( new, auths[i], (XdmcpNetaddr)d->peer.data,
					                 d->peer.length, d->name, &ok );
#endif
				break;
			}
		}
		/* now write other authorizations */
		for (i = 0; i < d->authNum; i++) {
			if (i != magicCookie) {
				data_len = auths[i]->data_length;
				/* client will just use default Kerberos cache, so don't
				 * even write cache info into the authority file.
				 */
				if (auths[i]->name_length == 14 &&
				    !strncmp( auths[i]->name, "MIT-KERBEROS-5", 14 ))
					auths[i]->data_length = 0;
				if ((d->displayType & d_location) == dLocal)
					writeLocalAuth( new, auths[i], d->name, &ok );
#ifdef XDMCP
				else
					writeRemoteAuth( new, auths[i], (XdmcpNetaddr)d->peer.data,
					                 d->peer.length, d->name, &ok );
#endif
				auths[i]->data_length = data_len;
			}
		}
		if (!endUserAuth( old, new, new_name, ok )) {
			if (!name) {
				logError( "Cannot save user authorization\n" );
				return;
			}
			undoUserAuth( name, new_name );
			initAddrs();
			goto fallback;
		}
		if (name)
			envname = moveUserAuth( name, new_name, envname );
		if (envname) {
			userEnviron = setEnv( userEnviron, "XAUTHORITY", envname );
			systemEnviron = setEnv( systemEnviron, "XAUTHORITY", envname );
		}
		/* a chown() used to be here, but this code runs as user anyway */
	}
	debug( "done setUserAuthorization\n" );
}

void
removeUserAuthorization( struct display *d )
{
	Xauth **auths;
	FILE *old, *new;
	int i;
	char name[NBSIZE], new_name[NBSIZE + 2];

	if (!(auths = d->authorizations))
		return;
	debug( "removeUserAuthorization\n" );
	startUserAuth( name, new_name, &old, &new );
	if (new) {
		for (i = 0; i < d->authNum; i++) {
			if ((d->displayType & d_location) == dLocal)
				writeLocalAuth( new, auths[i], d->name, 0 );
#ifdef XDMCP
			else
				writeRemoteAuth( new, auths[i], (XdmcpNetaddr)d->peer.data,
				                 d->peer.length, d->name, 0 );
#endif
		}
		if (endUserAuth( old, new, new_name, True ))
			(void)moveUserAuth( name, new_name, 0 );
		else
			undoUserAuth( name, new_name );
	}
	debug( "done removeUserAuthorization\n" );
}
