Part 2 of prior commit

1 files changed, 1165 insertions, 0 deletions

diff --git a/tdm/backend/xdmcp.c b/tdm/backend/xdmcp.c
new file mode 100644
index 000000000..6abaf5fc8
--- /dev/null
+++ b/tdm/backend/xdmcp.c
@@ -0,0 +1,1165 @@
+/*
+
+Copyright 1988, 1998  The Open Group
+Copyright 2002 Sun Microsystems, Inc.  All rights reserved.
+Copyright 2001-2004 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
+ *
+ * xdmcp.c - Support for XDMCP
+ */
+
+#include <config.h>
+
+#ifdef XDMCP
+
+#include "dm.h"
+#include "dm_error.h"
+#include "dm_auth.h"
+#include "dm_socket.h"
+
+#include <sys/types.h>
+#include <ctype.h>
+
+#include <netdb.h>
+#if defined(IPv6) && defined(AF_INET6)
+# include <arpa/inet.h>
+#endif
+
+/*
+ * Forward reference
+ */
+static void broadcast_respond( struct sockaddr *from, int fromlen, int length, int fd );
+static void forward_respond (struct sockaddr *from, int fromlen, int length, int fd);
+static void manage( struct sockaddr *from, int fromlen, int length, int fd );
+static void query_respond( struct sockaddr *from, int fromlen, int length, int fd );
+static void request_respond( struct sockaddr *from, int fromlen, int length, int fd );
+static void send_accept( struct sockaddr *to, int tolen, CARD32 sessionID, ARRAY8Ptr authenticationName, ARRAY8Ptr authenticationData, ARRAY8Ptr authorizationName, ARRAY8Ptr authorizationData, int fd );
+static void send_alive( struct sockaddr *from, int fromlen, int length, int fd );
+static void send_decline( struct sockaddr *to, int tolen, ARRAY8Ptr authenticationName, ARRAY8Ptr authenticationData, ARRAY8Ptr status, int fd );
+static void send_failed( struct sockaddr *from, int fromlen, const char *name, CARD32 sessionID, const char *reason, int fd );
+static void send_refuse( struct sockaddr *from, int fromlen, CARD32 sessionID, int fd );
+static void send_unwilling( struct sockaddr *from, int fromlen, ARRAY8Ptr authenticationName, ARRAY8Ptr status, int fd );
+static void send_willing( struct sockaddr *from, int fromlen, ARRAY8Ptr authenticationName, ARRAY8Ptr status, int fd );
+
+
+static XdmcpBuffer buffer;
+
+static void
+sendForward( CARD16 connectionType, ARRAY8Ptr address, char *closure )
+{
+#ifdef AF_INET
+	struct sockaddr_in in_addr;
+#endif
+#if defined(IPv6) && defined(AF_INET6)
+	struct sockaddr_in6 in6_addr;
+#endif
+#ifdef AF_DECnet
+#endif
+	struct sockaddr *addr;
+	int addrlen;
+
+	switch (connectionType) {
+#ifdef AF_INET
+	case FamilyInternet:
+		addr = (struct sockaddr *)&in_addr;
+		bzero( (char *)&in_addr, sizeof(in_addr) );
+# ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
+		in_addr.sin_len = sizeof(in_addr);
+# endif
+		in_addr.sin_family = AF_INET;
+		in_addr.sin_port = htons( (short)XDM_UDP_PORT );
+		if (address->length != 4)
+			return;
+		memmove( (char *)&in_addr.sin_addr, address->data, address->length );
+		addrlen = sizeof(struct sockaddr_in);
+		break;
+#endif
+#if defined(IPv6) && defined(AF_INET6)
+	case FamilyInternet6:
+		addr = (struct sockaddr *)&in6_addr;
+		bzero( (char *)&in6_addr, sizeof(in6_addr) );
+# ifdef SIN6_LEN
+		in6_addr.sin6_len = sizeof(in6_addr);
+# endif
+		in6_addr.sin6_family = AF_INET6;
+		in6_addr.sin6_port = htons( (short)XDM_UDP_PORT );
+		if (address->length != 16)
+			return;
+		memmove( (char *)&in6_addr.sin6_addr, address->data, address->length );
+		addrlen = sizeof(struct sockaddr_in6);
+		break;
+#endif
+#ifdef AF_DECnet
+	case FamilyDECnet:
+#endif
+	default:
+		return;
+	}
+	XdmcpFlush( (int)closure, &buffer, (XdmcpNetaddr)addr, addrlen );
+	return;
+}
+
+static void
+ClientAddress( struct sockaddr *from,
+               ARRAY8Ptr addr, /* return */
+               ARRAY8Ptr port, /* return */
+               CARD16 *type ) /* return */
+{
+	int length, family;
+	char *data;
+
+	data = NetaddrPort( (XdmcpNetaddr)from, &length );
+	XdmcpAllocARRAY8( port, length );
+	memmove( port->data, data, length );
+	port->length = length;
+
+	family = ConvertAddr( (XdmcpNetaddr)from, &length, &data );
+	XdmcpAllocARRAY8( addr, length );
+	memmove( addr->data, data, length );
+	addr->length = length;
+
+	*type = family;
+}
+
+static void
+all_query_respond( struct sockaddr *from, int fromlen,
+                   ARRAYofARRAY8Ptr authenticationNames,
+                   xdmOpCode type, int fd )
+{
+	ARRAY8Ptr authenticationName;
+	ARRAY8 status;
+	ARRAY8 addr;
+	CARD16 connectionType;
+	int family;
+	int length;
+
+	family = ConvertAddr( (XdmcpNetaddr)from, &length, &(addr.data) );
+	addr.length = length; /* convert int to short */
+	Debug( "all_query_respond: conntype=%d, addr=%02[*:hhx\n",
+	       family, addr.length, addr.data );
+	if (family < 0)
+		return;
+	connectionType = family;
+
+	if (type == INDIRECT_QUERY)
+		RememberIndirectClient( &addr, connectionType );
+	else
+		ForgetIndirectClient( &addr, connectionType );
+
+	authenticationName = ChooseAuthentication( authenticationNames );
+	if (Willing( &addr, connectionType, authenticationName, &status, type ))
+		send_willing( from, fromlen, authenticationName, &status, fd );
+	else
+		if (type == QUERY)
+			send_unwilling( from, fromlen, authenticationName, &status, fd );
+	XdmcpDisposeARRAY8( &status );
+}
+
+static void
+indirect_respond( struct sockaddr *from, int fromlen, int length, int fd )
+{
+	ARRAYofARRAY8 queryAuthenticationNames;
+	ARRAY8 clientAddress;
+	ARRAY8 clientPort;
+	CARD16 connectionType;
+	int expectedLen;
+	int i;
+	XdmcpHeader header;
+	int localHostAsWell;
+
+	Debug( "<indirect> respond %d\n", length );
+	if (!XdmcpReadARRAYofARRAY8( &buffer, &queryAuthenticationNames ))
+		return;
+	expectedLen = 1;
+	for (i = 0; i < (int)queryAuthenticationNames.length; i++)
+		expectedLen += 2 + queryAuthenticationNames.data[i].length;
+	if (length == expectedLen) {
+		ClientAddress( from, &clientAddress, &clientPort, &connectionType );
+		/*
+		 * set up the forward query packet
+		 */
+		header.version = XDM_PROTOCOL_VERSION;
+		header.opcode = (CARD16)FORWARD_QUERY;
+		header.length = 0;
+		header.length += 2 + clientAddress.length;
+		header.length += 2 + clientPort.length;
+		header.length += 1;
+		for (i = 0; i < (int)queryAuthenticationNames.length; i++)
+			header.length += 2 + queryAuthenticationNames.data[i].length;
+		XdmcpWriteHeader( &buffer, &header );
+		XdmcpWriteARRAY8( &buffer, &clientAddress );
+		XdmcpWriteARRAY8( &buffer, &clientPort );
+		XdmcpWriteARRAYofARRAY8( &buffer, &queryAuthenticationNames );
+
+		localHostAsWell =
+			ForEachMatchingIndirectHost( &clientAddress, connectionType,
+			                             sendForward, (char *)fd );
+
+		XdmcpDisposeARRAY8( &clientAddress );
+		XdmcpDisposeARRAY8( &clientPort );
+		if (localHostAsWell)
+			all_query_respond( from, fromlen, &queryAuthenticationNames,
+			                   INDIRECT_QUERY, fd );
+	} else
+		Debug( "<indirect> length error got %d expect %d\n",
+		       length, expectedLen );
+	XdmcpDisposeARRAYofARRAY8( &queryAuthenticationNames );
+}
+
+void
+ProcessRequestSocket( int fd )
+{
+	XdmcpHeader header;
+#if defined(IPv6) && defined(AF_INET6)
+	struct sockaddr_storage addr;
+#else
+	struct sockaddr addr;
+#endif
+	int addrlen = sizeof(addr);
+
+	Debug( "ProcessRequestSocket\n" );
+	bzero( (char *)&addr, sizeof(addr) );
+	if (!XdmcpFill( fd, &buffer, (XdmcpNetaddr)&addr, &addrlen )) {
+		Debug( "XdmcpFill failed\n" );
+		return;
+	}
+	if (!XdmcpReadHeader( &buffer, &header )) {
+		Debug( "XdmcpReadHeader failed\n" );
+		return;
+	}
+	if (header.version != XDM_PROTOCOL_VERSION) {
+		Debug( "XDMCP header version read was %d, expected %d\n",
+		       header.version, XDM_PROTOCOL_VERSION );
+		return;
+	}
+	Debug( "header: %d %d %d\n", header.version, header.opcode, header.length );
+	switch (header.opcode) {
+	case BROADCAST_QUERY:
+		broadcast_respond( (struct sockaddr *)&addr, addrlen, header.length, fd );
+		break;
+	case QUERY:
+		query_respond( (struct sockaddr *)&addr, addrlen, header.length, fd );
+		break;
+	case INDIRECT_QUERY:
+		indirect_respond( (struct sockaddr *)&addr, addrlen, header.length, fd );
+		break;
+	case FORWARD_QUERY:
+		forward_respond ((struct sockaddr *)&addr, addrlen, header.length, fd);
+		break;
+	case REQUEST:
+		request_respond( (struct sockaddr *)&addr, addrlen, header.length, fd );
+		break;
+	case MANAGE:
+		manage( (struct sockaddr *)&addr, addrlen, header.length, fd );
+		break;
+	case KEEPALIVE:
+		send_alive( (struct sockaddr *)&addr, addrlen, header.length, fd );
+		break;
+	}
+}
+
+/*
+ * respond to a request on the UDP socket.
+ */
+
+static void
+direct_query_respond( struct sockaddr *from, int fromlen,
+                      int length, xdmOpCode type, int fd )
+{
+	ARRAYofARRAY8 queryAuthenticationNames;
+	int expectedLen;
+	int i;
+
+	if (!XdmcpReadARRAYofARRAY8( &buffer, &queryAuthenticationNames ))
+		return;
+	expectedLen = 1;
+	for (i = 0; i < (int)queryAuthenticationNames.length; i++)
+		expectedLen += 2 + queryAuthenticationNames.data[i].length;
+	if (length == expectedLen)
+		all_query_respond( from, fromlen, &queryAuthenticationNames, type, fd );
+	XdmcpDisposeARRAYofARRAY8( &queryAuthenticationNames );
+}
+
+static void
+query_respond( struct sockaddr *from, int fromlen, int length, int fd )
+{
+	Debug( "<query> respond %d\n", length );
+	direct_query_respond( from, fromlen, length, QUERY, fd );
+}
+
+static void
+broadcast_respond( struct sockaddr *from, int fromlen, int length, int fd )
+{
+	direct_query_respond( from, fromlen, length, BROADCAST_QUERY, fd );
+}
+
+/* computes an X display name */
+
+static char *
+NetworkAddressToName( CARD16 connectionType, ARRAY8Ptr connectionAddress,
+                      struct sockaddr *originalAddress, CARD16 displayNumber )
+{
+	switch (connectionType) {
+	case FamilyInternet:
+#if defined(IPv6) && defined(AF_INET6)
+	case FamilyInternet6:
+#endif
+		{
+			CARD8 *data;
+			struct hostent *hostent;
+			char *hostname = NULL;
+			char *name;
+			const char *localhost;
+			int multiHomed = 0;
+			int type;
+#if defined(IPv6) && defined(AF_INET6)
+			struct addrinfo  *ai = NULL, *nai, hints;
+			char  dotted[INET6_ADDRSTRLEN];
+
+			if (connectionType == FamilyInternet6)
+				type = AF_INET6;
+			else
+#endif
+				type = AF_INET;
+
+			data = connectionAddress->data;
+			hostent = gethostbyaddr( (char *)data,
+			                         connectionAddress->length, type );
+			if (hostent) {
+				if (sourceAddress) {
+#if defined(IPv6) && defined(AF_INET6)
+					bzero( &hints, sizeof(hints) );
+					hints.ai_flags = AI_CANONNAME;
+					if (!getaddrinfo( hostent->h_name, NULL, &hints, &ai )) {
+						hostname = ai->ai_canonname;
+						for (nai = ai->ai_next; nai; nai = nai->ai_next)
+							if (ai->ai_protocol == nai->ai_protocol &&
+							    memcmp( ai->ai_addr, nai->ai_addr,
+							            ai->ai_addrlen ))
+								multiHomed = 1;
+					}
+#else
+					hostent = gethostbyname( hostent->h_name );
+					if (hostent && hostent->h_addrtype == AF_INET) {
+						multiHomed = hostent->h_addr_list[1] != NULL;
+						hostname = hostent->h_name;
+					}
+#endif
+				} else
+					hostname = hostent->h_name;
+			}
+
+			localhost = localHostname();
+
+			/*
+			 * protect against bogus host names
+			 */
+			if (hostname && *hostname && *hostname != '.' && !multiHomed) {
+				if (!strcmp( localhost, hostname ))
+					ASPrintf( &name, "localhost:%d", displayNumber );
+				else {
+					if (removeDomainname) {
+						char *remoteDot;
+						char *localDot;
+
+						/* check for a common domain name.	This
+						 * could reduce names by recognising common
+						 * super-domain names as well, but I don't think
+						 * this is as useful, and will confuse more
+						 * people
+						 */
+						if ((localDot = strchr( localhost, '.' )) &&
+						    (remoteDot = strchr( hostname, '.' )))
+						{
+							/* smash the name in place; it won't
+							 * be needed later.
+							 */
+							if (!strcmp( localDot+1, remoteDot+1 ))
+								*remoteDot = '\0';
+						}
+					}
+
+					ASPrintf( &name, "%s:%d", hostname, displayNumber );
+				}
+			} else {
+#if defined(IPv6) && defined(AF_INET6)
+				if (multiHomed) {
+					if (connectionType == FamilyInternet) {
+						data = (CARD8 *)
+							&((struct sockaddr_in *)originalAddress)->sin_addr;
+					} else {
+						data = (CARD8 *)
+							&((struct sockaddr_in6 *)originalAddress)->sin6_addr;
+					}
+				}
+				inet_ntop( type, data, dotted, sizeof(dotted) );
+				ASPrintf( &name, "%s:%d", dotted, displayNumber );
+#else
+				if (multiHomed)
+					data = (CARD8 *)
+						&((struct sockaddr_in *)originalAddress)->sin_addr;
+				ASPrintf( &name, "%[4|'.'hhu:%d", data, displayNumber );
+#endif
+			}
+#if defined(IPv6) && defined(AF_INET6)
+			if (ai)
+				freeaddrinfo( ai );
+#endif
+			return name;
+		}
+#ifdef DNET
+	case FamilyDECnet:
+		return NULL;
+#endif /* DNET */
+	default:
+		return NULL;
+	}
+}
+
+/*ARGSUSED*/
+static void
+forward_respond ( struct sockaddr *from, int fromlen ATTR_UNUSED,
+                 int length, int fd)
+{
+	ARRAY8 clientAddress;
+	ARRAY8 clientPort;
+	ARRAYofARRAY8 authenticationNames;
+	struct sockaddr *client;
+	int clientlen;
+	int expectedLen;
+	int i;
+
+	Debug( "<forward> respond %d\n", length );
+	clientAddress.length = 0;
+	clientAddress.data = 0;
+	clientPort.length = 0;
+	clientPort.data = 0;
+	authenticationNames.length = 0;
+	authenticationNames.data = 0;
+	if (XdmcpReadARRAY8( &buffer, &clientAddress ) &&
+	    XdmcpReadARRAY8( &buffer, &clientPort ) &&
+	    XdmcpReadARRAYofARRAY8( &buffer, &authenticationNames ))
+	{
+		expectedLen = 0;
+		expectedLen += 2 + clientAddress.length;
+		expectedLen += 2 + clientPort.length;
+		expectedLen += 1; /* authenticationNames */
+		for (i = 0; i < (int)authenticationNames.length; i++)
+			expectedLen += 2 + authenticationNames.data[i].length;
+		if (length == expectedLen) {
+			int j;
+
+			j = 0;
+			for (i = 0; i < (int)clientPort.length; i++)
+				j = j * 256 + clientPort.data[i];
+			Debug( "<forward> client address (port %d) %[*hhu\n", j,
+			       clientAddress.length, clientAddress.data );
+			switch (from->sa_family) {
+#ifdef AF_INET
+			case AF_INET:
+				{
+					struct sockaddr_in in_addr;
+
+					if (clientAddress.length != 4 || clientPort.length != 2)
+						goto badAddress;
+					bzero( (char *)&in_addr, sizeof(in_addr) );
+#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
+					in_addr.sin_len = sizeof(in_addr);
+#endif
+					in_addr.sin_family = AF_INET;
+					memmove( &in_addr.sin_addr, clientAddress.data, 4 );
+					memmove( (char *)&in_addr.sin_port, clientPort.data, 2 );
+					client = (struct sockaddr *)&in_addr;
+					clientlen = sizeof(in_addr);
+					all_query_respond( client, clientlen, &authenticationNames,
+					                   FORWARD_QUERY, fd );
+				}
+				break;
+#endif
+#if defined(IPv6) && defined(AF_INET6)
+			case AF_INET6:
+				{
+					struct sockaddr_in6 in6_addr;
+
+					if (clientAddress.length != 16 || clientPort.length != 2)
+						goto badAddress;
+					bzero( (char *)&in6_addr, sizeof(in6_addr) );
+#ifdef SIN6_LEN
+					in6_addr.sin6_len = sizeof(in6_addr);
+#endif
+					in6_addr.sin6_family = AF_INET6;
+					memmove( &in6_addr,clientAddress.data,clientAddress.length );
+					memmove( (char *)&in6_addr.sin6_port, clientPort.data, 2 );
+					client = (struct sockaddr *)&in6_addr;
+					clientlen = sizeof(in6_addr);
+					all_query_respond( client, clientlen, &authenticationNames,
+					                   FORWARD_QUERY, fd );
+				}
+				break;
+#endif
+#ifdef AF_UNIX
+			case AF_UNIX:
+				{
+					struct sockaddr_un un_addr;
+
+					if (clientAddress.length >= sizeof(un_addr.sun_path))
+						goto badAddress;
+					bzero( (char *)&un_addr, sizeof(un_addr) );
+					un_addr.sun_family = AF_UNIX;
+					memmove( un_addr.sun_path, clientAddress.data, clientAddress.length );
+					un_addr.sun_path[clientAddress.length] = '\0';
+					client = (struct sockaddr *)&un_addr;
+#if defined(HAVE_STRUCT_SOCKADDR_IN_SIN_LEN) && !defined(__Lynx__) && defined(UNIXCONN)
+					un_addr.sun_len = strlen( un_addr.sun_path );
+					clientlen = SUN_LEN( &un_addr );
+#else
+					clientlen = sizeof(un_addr);
+#endif
+					all_query_respond( client, clientlen, &authenticationNames,
+					                   FORWARD_QUERY, fd );
+				}
+				break;
+#endif
+#ifdef AF_CHAOS
+			case AF_CHAOS:
+				goto badAddress;
+#endif
+#ifdef AF_DECnet
+			case AF_DECnet:
+				goto badAddress;
+#endif
+			}
+		} else
+			Debug( "<forward> length error got %d expect %d\n", length, expectedLen );
+	}
+  badAddress:
+	XdmcpDisposeARRAY8( &clientAddress );
+	XdmcpDisposeARRAY8( &clientPort );
+	XdmcpDisposeARRAYofARRAY8( &authenticationNames );
+}
+
+static ARRAY8 Hostname;
+
+static void
+send_willing( struct sockaddr *from, int fromlen,
+             ARRAY8Ptr authenticationName, ARRAY8Ptr status, int fd )
+{
+	XdmcpHeader header;
+
+	Debug( "send <willing> %.*s %.*s\n", authenticationName->length,
+	       authenticationName->data,
+	       status->length,
+	       status->data );
+	header.version = XDM_PROTOCOL_VERSION;
+	header.opcode = (CARD16)WILLING;
+	header.length =
+		6 + authenticationName->length + Hostname.length + status->length;
+	XdmcpWriteHeader( &buffer, &header );
+	XdmcpWriteARRAY8( &buffer, authenticationName );
+	XdmcpWriteARRAY8( &buffer, &Hostname );
+	XdmcpWriteARRAY8( &buffer, status );
+	XdmcpFlush( fd, &buffer, (XdmcpNetaddr)from, fromlen );
+}
+
+static void
+send_unwilling( struct sockaddr *from, int fromlen,
+               ARRAY8Ptr authenticationName, ARRAY8Ptr status, int fd )
+{
+	XdmcpHeader header;
+
+	Debug( "send <unwilling> %.*s %.*s\n", authenticationName->length,
+	       authenticationName->data,
+	       status->length,
+	       status->data );
+	header.version = XDM_PROTOCOL_VERSION;
+	header.opcode = (CARD16)UNWILLING;
+	header.length = 4 + Hostname.length + status->length;
+	XdmcpWriteHeader( &buffer, &header );
+	XdmcpWriteARRAY8( &buffer, &Hostname );
+	XdmcpWriteARRAY8( &buffer, status );
+	XdmcpFlush( fd, &buffer, (XdmcpNetaddr)from, fromlen );
+}
+
+static unsigned long globalSessionID;
+
+#define NextSessionID() (++globalSessionID)
+
+void init_session_id( void )
+{
+	/* Set randomly so we are unlikely to reuse id's from a previous
+	 * incarnation so we don't say "Alive" to those displays.
+	 * Start with low digits 0 to make debugging easier.
+	 */
+	globalSessionID = (time( (Time_t *)0 ) & 0x7fff) * 16000;
+
+	Hostname.data = (char *)localHostname();
+	Hostname.length = strlen( Hostname.data );
+}
+
+static ARRAY8 outOfMemory = { (CARD16)13, (CARD8Ptr)"Out of memory" };
+static ARRAY8 noValidAddr = { (CARD16)16, (CARD8Ptr)"No valid address" };
+static ARRAY8 noValidAuth = { (CARD16)22, (CARD8Ptr)"No valid authorization" };
+static ARRAY8 noAuthentic = { (CARD16)29, (CARD8Ptr)"XDM has no authentication key" };
+
+static void
+request_respond( struct sockaddr *from, int fromlen, int length, int fd )
+{
+	CARD16 displayNumber;
+	ARRAY16 connectionTypes;
+	ARRAYofARRAY8 connectionAddresses;
+	ARRAY8 authenticationName;
+	ARRAY8 authenticationData;
+	ARRAYofARRAY8 authorizationNames;
+	ARRAY8 manufacturerDisplayID;
+	ARRAY8Ptr reason = 0;
+	int expectlen;
+	int i, j;
+	struct protoDisplay  *pdpy;
+	ARRAY8 authorizationName, authorizationData;
+	ARRAY8Ptr connectionAddress;
+
+	Debug( "<request> respond %d\n", length );
+	connectionTypes.data = 0;
+	connectionAddresses.data = 0;
+	authenticationName.data = 0;
+	authenticationData.data = 0;
+	authorizationNames.data = 0;
+	authorizationName.length = 0;
+	authorizationData.length = 0;
+	manufacturerDisplayID.data = 0;
+	if (XdmcpReadCARD16( &buffer, &displayNumber ) &&
+	    XdmcpReadARRAY16( &buffer, &connectionTypes ) &&
+	    XdmcpReadARRAYofARRAY8( &buffer, &connectionAddresses ) &&
+	    XdmcpReadARRAY8( &buffer, &authenticationName ) &&
+	    XdmcpReadARRAY8( &buffer, &authenticationData ) &&
+	    XdmcpReadARRAYofARRAY8( &buffer, &authorizationNames ) &&
+	    XdmcpReadARRAY8( &buffer, &manufacturerDisplayID ))
+	{
+		expectlen = 0;
+		expectlen += 2; /* displayNumber */
+		expectlen += 1 + 2 * connectionTypes.length; /* connectionTypes */
+		expectlen += 1; /* connectionAddresses */
+		for (i = 0; i < (int)connectionAddresses.length; i++)
+			expectlen += 2 + connectionAddresses.data[i].length;
+		expectlen += 2 + authenticationName.length; /* authenticationName */
+		expectlen += 2 + authenticationData.length; /* authenticationData */
+		expectlen += 1; /* authoriationNames */
+		for (i = 0; i < (int)authorizationNames.length; i++)
+			expectlen += 2 + authorizationNames.data[i].length;
+		expectlen += 2 + manufacturerDisplayID.length; /* displayID */
+		if (expectlen != length) {
+			Debug( "<request> length error got %d expect %d\n",
+			       length, expectlen );
+			goto abort;
+		}
+		if (connectionTypes.length == 0 ||
+		    connectionAddresses.length != connectionTypes.length)
+		{
+			reason = &noValidAddr;
+			pdpy = 0;
+			goto decline;
+		}
+		pdpy = FindProtoDisplay( (XdmcpNetaddr)from, fromlen, displayNumber );
+		if (!pdpy) {
+
+			/* Check this Display against the Manager's policy */
+			reason = Accept( from, fromlen, displayNumber );
+			if (reason)
+				goto decline;
+
+			/* Check the Display's stream services against Manager's policy */
+			i = SelectConnectionTypeIndex( &connectionTypes,
+			                               &connectionAddresses );
+			if (i < 0) {
+				reason = &noValidAddr;
+				goto decline;
+			}
+
+			/* The Manager considers this a new session */
+			connectionAddress = &connectionAddresses.data[i];
+			pdpy = NewProtoDisplay( (XdmcpNetaddr)from, fromlen, displayNumber,
+			                        connectionTypes.data[i], connectionAddress,
+			                        NextSessionID() );
+			Debug( "NewProtoDisplay %p\n", pdpy );
+			if (!pdpy) {
+				reason = &outOfMemory;
+				goto decline;
+			}
+		}
+		if (authorizationNames.length == 0)
+			j = 0;
+		else
+			j = SelectAuthorizationTypeIndex( &authenticationName,
+			                                  &authorizationNames );
+		if (j < 0) {
+			reason = &noValidAuth;
+			goto decline;
+		}
+		if (!CheckAuthentication( pdpy,
+		                          &manufacturerDisplayID,
+		                          &authenticationName,
+		                          &authenticationData ))
+		{
+			reason = &noAuthentic;
+			goto decline;
+		}
+		if (j < (int)authorizationNames.length) {
+			Xauth *auth;
+			SetProtoDisplayAuthorization( pdpy,
+			                              (unsigned short)authorizationNames.data[j].length,
+			                              (char *)authorizationNames.data[j].data );
+			auth = pdpy->xdmcpAuthorization;
+			if (!auth)
+				auth = pdpy->fileAuthorization;
+			if (auth) {
+				authorizationName.length = auth->name_length;
+				authorizationName.data = (CARD8Ptr) auth->name;
+				authorizationData.length = auth->data_length;
+				authorizationData.data = (CARD8Ptr) auth->data;
+			}
+		}
+		if (pdpy) {
+			send_accept( from, fromlen, pdpy->sessionID,
+			             &authenticationName,
+			             &authenticationData,
+			             &authorizationName,
+			             &authorizationData, fd );
+		} else {
+  decline:
+			send_decline( from, fromlen, &authenticationName,
+			              &authenticationData,
+			              reason, fd );
+			if (pdpy)
+				DisposeProtoDisplay( pdpy );
+		}
+	}
+  abort:
+	XdmcpDisposeARRAY16( &connectionTypes );
+	XdmcpDisposeARRAYofARRAY8( &connectionAddresses );
+	XdmcpDisposeARRAY8( &authenticationName );
+	XdmcpDisposeARRAY8( &authenticationData );
+	XdmcpDisposeARRAYofARRAY8( &authorizationNames );
+	XdmcpDisposeARRAY8( &manufacturerDisplayID );
+}
+
+static void
+send_accept( struct sockaddr *to, int tolen, CARD32 sessionID,
+            ARRAY8Ptr authenticationName, ARRAY8Ptr authenticationData,
+            ARRAY8Ptr authorizationName, ARRAY8Ptr authorizationData,
+            int fd )
+{
+	XdmcpHeader header;
+
+	Debug( "<accept> session ID %ld\n", (long)sessionID );
+	header.version = XDM_PROTOCOL_VERSION;
+	header.opcode = (CARD16)ACCEPT;
+	header.length = 4; /* session ID */
+	header.length += 2 + authenticationName->length;
+	header.length += 2 + authenticationData->length;
+	header.length += 2 + authorizationName->length;
+	header.length += 2 + authorizationData->length;
+	XdmcpWriteHeader( &buffer, &header );
+	XdmcpWriteCARD32( &buffer, sessionID );
+	XdmcpWriteARRAY8( &buffer, authenticationName );
+	XdmcpWriteARRAY8( &buffer, authenticationData );
+	XdmcpWriteARRAY8( &buffer, authorizationName );
+	XdmcpWriteARRAY8( &buffer, authorizationData );
+	XdmcpFlush( fd, &buffer, (XdmcpNetaddr)to, tolen );
+}
+
+static void
+send_decline( struct sockaddr *to, int tolen,
+             ARRAY8Ptr authenticationName, ARRAY8Ptr authenticationData,
+             ARRAY8Ptr status, int fd )
+{
+	XdmcpHeader header;
+
+	Debug( "<decline> %.*s\n", status->length, status->data );
+	header.version = XDM_PROTOCOL_VERSION;
+	header.opcode = (CARD16)DECLINE;
+	header.length = 0;
+	header.length += 2 + status->length;
+	header.length += 2 + authenticationName->length;
+	header.length += 2 + authenticationData->length;
+	XdmcpWriteHeader( &buffer, &header );
+	XdmcpWriteARRAY8( &buffer, status );
+	XdmcpWriteARRAY8( &buffer, authenticationName );
+	XdmcpWriteARRAY8( &buffer, authenticationData );
+	XdmcpFlush( fd, &buffer, (XdmcpNetaddr)to, tolen );
+}
+
+static void
+manage( struct sockaddr *from, int fromlen, int length, int fd )
+{
+	CARD32 sessionID;
+	CARD16 displayNumber;
+	ARRAY8 displayClass;
+	int expectlen;
+	struct protoDisplay *pdpy;
+	struct display *d;
+	char *name = NULL;
+	char *class2 = NULL;
+	XdmcpNetaddr from_save;
+	ARRAY8 clientAddress, clientPort;
+	CARD16 connectionType;
+
+	Debug( "<manage> %d\n", length );
+	displayClass.data = 0;
+	displayClass.length = 0;
+	if (XdmcpReadCARD32( &buffer, &sessionID ) &&
+	    XdmcpReadCARD16( &buffer, &displayNumber ) &&
+	    XdmcpReadARRAY8( &buffer, &displayClass ))
+	{
+		expectlen = 4 + /* session ID */
+					2 + /* displayNumber */
+					2 + displayClass.length; /* displayClass */
+		if (expectlen != length) {
+			Debug( "<manage> length error got %d expect %d\n", length, expectlen );
+			goto abort;
+		}
+		pdpy = FindProtoDisplay( (XdmcpNetaddr)from, fromlen, displayNumber );
+		Debug( "<manage> session ID %ld, pdpy %p\n", (long)sessionID, pdpy );
+		if (!pdpy || pdpy->sessionID != sessionID) {
+			/*
+			 * We may have already started a session for this display
+			 * but it hasn't seen the response in the form of an
+			 * XOpenDisplay() yet. So check if it is in the list of active
+			 * displays, and if so check that the session id's match.
+			 * If all this is true, then we have a duplicate request that
+			 * can be ignored.
+			 */
+			if (!pdpy &&
+			    (d = FindDisplayByAddress( (XdmcpNetaddr)from, fromlen,
+			                               displayNumber )) &&
+			    d->sessionID == sessionID)
+			{
+					Debug( "manage: got duplicate pkt, ignoring\n" );
+					goto abort;
+			}
+			Debug( "session ID %ld refused\n", (long)sessionID );
+			if (pdpy)
+				Debug( "existing session ID %ld\n", (long)pdpy->sessionID );
+			send_refuse( from, fromlen, sessionID, fd );
+		} else {
+			name = NetworkAddressToName( pdpy->connectionType,
+			                             &pdpy->connectionAddress,
+			                             from,
+			                             pdpy->displayNumber );
+			if (!name) {
+				Debug( "could not compute display name\n" );
+				send_failed( from, fromlen, "(no name)", sessionID,
+				             "out of memory", fd );
+				goto abort;
+			}
+			Debug( "computed display name: %s\n", name );
+			if ((d = FindDisplayByName( name ))) {
+				Debug( "terminating active session for %s\n", d->name );
+				StopDisplay( d );
+			}
+			if (displayClass.length) {
+				if (!StrNDup( &class2, (char *)displayClass.data,
+				              displayClass.length ))
+				{
+					send_failed( from, fromlen, name, sessionID,
+					             "out of memory", fd );
+					goto abort;
+				}
+			}
+			if (!(from_save = (XdmcpNetaddr)Malloc( fromlen ))) {
+				send_failed( from, fromlen, name, sessionID,
+				             "out of memory", fd );
+				goto abort;
+			}
+			memmove( from_save, from, fromlen );
+			if (!(d = NewDisplay( name ))) {
+				free( (char *)from_save );
+				send_failed( from, fromlen, name, sessionID,
+				             "out of memory", fd );
+				goto abort;
+			}
+			d->class2 = class2;
+			class2 = 0;
+			d->displayType = dForeign | dTransient | dFromXDMCP;
+			d->sessionID = pdpy->sessionID;
+			d->from.data = (unsigned char *)from_save;
+			d->from.length = fromlen;
+			d->displayNumber = pdpy->displayNumber;
+			ClientAddress( from, &clientAddress, &clientPort,
+			               &connectionType );
+			d->useChooser = 0;
+			d->xdmcpFd = fd;
+			if (IsIndirectClient( &clientAddress, connectionType )) {
+				Debug( "IsIndirectClient\n" );
+				ForgetIndirectClient( &clientAddress, connectionType );
+				if (UseChooser( &clientAddress, connectionType )) {
+					d->useChooser = 1;
+					Debug( "use chooser for %s\n", d->name );
+				}
+			}
+			d->clientAddr = clientAddress;
+			d->connectionType = connectionType;
+			d->remoteHost = NetworkAddressToHostname (pdpy->connectionType,
+			                             &pdpy->connectionAddress);
+
+			XdmcpDisposeARRAY8( &clientPort );
+			if (pdpy->fileAuthorization) {
+				d->authorizations = (Xauth **)Malloc( sizeof(Xauth *) );
+				if (!d->authorizations) {
+					free( (char *)from_save );
+					free( (char *)d );
+					send_failed( from, fromlen, name, sessionID,
+					             "out of memory", fd );
+					goto abort;
+				}
+				d->authorizations[0] = pdpy->fileAuthorization;
+				d->authNum = 1;
+				pdpy->fileAuthorization = 0;
+			}
+			DisposeProtoDisplay( pdpy );
+			Debug( "starting display %s,%s\n", d->name, d->class2 );
+			if (LoadDisplayResources( d ) < 0) {
+				LogError( "Unable to read configuration for display %s; "
+				          "stopping it.\n", d->name );
+				StopDisplay( d );
+			} else
+				StartDisplay( d );
+			CloseGetter();
+		}
+	}
+abort:
+	XdmcpDisposeARRAY8( &displayClass );
+	if (name)
+		free( (char *)name );
+	if (class2)
+		free( (char *)class2 );
+}
+
+void
+SendFailed( struct display *d, const char *reason )
+{
+	Debug( "display start failed, sending <failed>\n" );
+	send_failed( (struct sockaddr *)(d->from.data), d->from.length, d->name,
+	             d->sessionID, reason, d->xdmcpFd );
+}
+
+static void
+send_failed( struct sockaddr *from, int fromlen,
+            const char *name, CARD32 sessionID, const char *reason, int fd )
+{
+	char buf[360];
+	XdmcpHeader header;
+	ARRAY8 status;
+
+	sprintf( buf, "Session %ld failed for display %.260s: %s",
+	         (long)sessionID, name, reason );
+	Debug( "send_failed(%\"s)\n", buf );
+	status.length = strlen( buf );
+	status.data = (CARD8Ptr) buf;
+	header.version = XDM_PROTOCOL_VERSION;
+	header.opcode = (CARD16)FAILED;
+	header.length = 6 + status.length;
+	XdmcpWriteHeader( &buffer, &header );
+	XdmcpWriteCARD32( &buffer, sessionID );
+	XdmcpWriteARRAY8( &buffer, &status );
+	XdmcpFlush( fd, &buffer, (XdmcpNetaddr)from, fromlen );
+}
+
+static void
+send_refuse( struct sockaddr *from, int fromlen, CARD32 sessionID, int fd )
+{
+	XdmcpHeader header;
+
+	Debug( "send <refuse> %ld\n", (long)sessionID );
+	header.version = XDM_PROTOCOL_VERSION;
+	header.opcode = (CARD16)REFUSE;
+	header.length = 4;
+	XdmcpWriteHeader( &buffer, &header );
+	XdmcpWriteCARD32( &buffer, sessionID );
+	XdmcpFlush( fd, &buffer, (XdmcpNetaddr)from, fromlen );
+}
+
+static void
+send_alive( struct sockaddr *from, int fromlen, int length, int fd )
+{
+	CARD32 sessionID;
+	CARD16 displayNumber;
+	struct display *d;
+	XdmcpHeader header;
+	CARD8 sendRunning;
+	CARD32 sendSessionID;
+
+	Debug( "send <alive>\n" );
+	if (XdmcpReadCARD16( &buffer, &displayNumber ) &&
+	    XdmcpReadCARD32( &buffer, &sessionID ))
+	{
+		if (length == 6) {
+			if (!(d = FindDisplayBySessionID( sessionID )))
+				d = FindDisplayByAddress( (XdmcpNetaddr)from, fromlen,
+				                          displayNumber );
+			sendRunning = 0;
+			sendSessionID = 0;
+			if (d && d->status == running) {
+				if (d->sessionID == sessionID)
+					sendRunning = 1;
+				sendSessionID = d->sessionID;
+			}
+			header.version = XDM_PROTOCOL_VERSION;
+			header.opcode = (CARD16)ALIVE;
+			header.length = 5;
+			Debug( "<alive>: %d %ld\n", sendRunning, (long)sendSessionID );
+			XdmcpWriteHeader( &buffer, &header );
+			XdmcpWriteCARD8( &buffer, sendRunning );
+			XdmcpWriteCARD32( &buffer, sendSessionID );
+			XdmcpFlush( fd, &buffer, (XdmcpNetaddr)from, fromlen );
+		}
+	}
+}
+
+char *
+NetworkAddressToHostname( CARD16 connectionType, ARRAY8Ptr connectionAddress )
+{
+	switch (connectionType) {
+	case FamilyInternet:
+#if defined(IPv6) && defined(AF_INET6)
+	case FamilyInternet6:
+#endif
+		{
+			struct hostent *he;
+			char *name, *lname;
+			char *myDot;
+			int af_type;
+#if defined(IPv6) && defined(AF_INET6)
+			char dotted[INET6_ADDRSTRLEN];
+
+			if (connectionType == FamilyInternet6)
+				af_type = AF_INET6;
+			else
+#endif
+				af_type = AF_INET;
+
+			he = gethostbyaddr( (char *)connectionAddress->data,
+			                    connectionAddress->length, af_type );
+			if (he) {
+#if defined(IPv6) && defined(AF_INET6)
+				struct addrinfo *ai, *nai;
+				if (!getaddrinfo( he->h_name, NULL, NULL, &ai )) {
+					for (nai = ai; nai; nai = nai->ai_next) {
+						if (af_type == nai->ai_family &&
+						    !memcmp( nai->ai_family == AF_INET ?
+						             (char *)&((struct sockaddr_in *)nai->ai_addr)->sin_addr :
+						             (char *)&((struct sockaddr_in6 *)nai->ai_addr)->sin6_addr,
+						             connectionAddress->data,
+						             connectionAddress->length ))
+						{
+							freeaddrinfo( ai );
+							goto oki;
+						}
+					}
+					freeaddrinfo( ai );
+#else
+				if ((he = gethostbyname( he->h_name )) &&
+				    he->h_addrtype == AF_INET)
+				{
+					int i;
+					for (i = 0; he->h_addr_list[i]; i++)
+						if (!memcmp( he->h_addr_list[i],
+						             connectionAddress->data, 4 ))
+							goto oki;
+#endif
+					LogError( "DNS spoof attempt or misconfigured resolver.\n" );
+				}
+				goto gotnone;
+			  oki:
+				if (StrDup( &name, he->h_name ) &&
+				    !strchr( name, '.' ) &&
+				    (myDot = strchr( localHostname(), '.' )))
+				{
+					if (ASPrintf( &lname, "%s%s", name, myDot )) {
+#if defined(IPv6) && defined(AF_INET6)
+						if (!getaddrinfo( lname, NULL, NULL, &ai )) {
+							for (nai = ai; nai; nai = nai->ai_next) {
+								if (af_type == nai->ai_family &&
+								    !memcmp( nai->ai_family == AF_INET ?
+								             (char *)&((struct sockaddr_in *)nai->ai_addr)->sin_addr :
+								             (char *)&((struct sockaddr_in6 *)nai->ai_addr)->sin6_addr,
+								             connectionAddress->data,
+								             connectionAddress->length ))
+								{
+									freeaddrinfo( ai );
+									free( name );
+									return lname;
+								}
+							}
+							freeaddrinfo( ai );
+						}
+#else
+						if ((he = gethostbyname( lname )) &&
+						    he->h_addrtype == AF_INET)
+						{
+							int i;
+							for (i = 0; he->h_addr_list[i]; i++)
+								if (!memcmp( he->h_addr_list[i],
+								             connectionAddress->data, 4 ))
+								{
+									free( name );
+									return lname;
+								}
+						}
+#endif
+						free( lname );
+					}
+				}
+			} else {
+			  gotnone:
+				/* can't get name, so use emergency fallback */
+#if defined(IPv6) && defined(AF_INET6)
+				inet_ntop( af_type, connectionAddress->data,
+				           dotted, sizeof(dotted) );
+				StrDup( &name, dotted );
+#else
+				ASPrintf( &name, "%[4|'.'hhu", connectionAddress->data );
+#endif
+				LogWarn( "Cannot convert Internet address %s to host name\n",
+				         name );
+			}
+			return name;
+		}
+#ifdef DNET
+	case FamilyDECnet:
+		break;
+#endif /* DNET */
+	default:
+		break;
+	}
+	return 0;
+}
+
+#endif /* XDMCP */
+