os: always check if client is local when connection is accepted

nx-X11/programs/Xserver/os/access.c

@@ -1217,12 +1217,17 @@ ResetHosts (char *display)
 }
 
 /* Is client on the local host */
-Bool LocalClient(ClientPtr client)
+Bool
+ComputeLocalClient(ClientPtr client)
 {
     int    		alen, family, notused;
     Xtransaddr		*from = NULL;
     void		*addr;
     register HOST	*host;
+    OsCommPtr		 oc = (OsCommPtr) client->osPrivate;
+
+    if (!oc->trans_conn)
+	return FALSE;
 
 #ifdef XCSECURITY
     /* untrusted clients can't change host access */
@@ -1233,8 +1238,7 @@ Bool LocalClient(ClientPtr client)
 	return FALSE;
     }
 #endif
-    if (!_XSERVTransGetPeerAddr (((OsCommPtr)client->osPrivate)->trans_conn,
-	&notused, &alen, &from))
+    if (!_XSERVTransGetPeerAddr (oc->trans_conn, &notused, &alen, &from))
     {
 	family = ConvertAddr ((struct sockaddr *) from,
 	    &alen, (void **)&addr);
@@ -1260,6 +1264,13 @@ Bool LocalClient(ClientPtr client)
     return FALSE;
 }
 
+Bool LocalClient(ClientPtr client)
+{
+    if (!client->osPrivate)
+	return FALSE;
+    return ((OsCommPtr)client->osPrivate)->local_client;
+}
+
 /*
  * Return the uid and gid of a connected local client
  * 

nx-X11/programs/Xserver/os/connection.c

@@ -754,6 +754,7 @@ AllocNewConnection (XtransConnInfo trans_conn, int fd, CARD32 conn_time)
 	free (oc);
 	return NullClient;
     }
+    oc->local_client = ComputeLocalClient(client);
     {
 #if !defined(WIN32)
 	ConnectionTranslation[fd] = client->index;

nx-X11/programs/Xserver/os/osdep.h

@@ -176,6 +176,7 @@ typedef struct _osComm {
     XID	auth_id;		/* authorization id */
     CARD32 conn_time;		/* timestamp if not established, else 0  */
     struct _XtransConnInfo *trans_conn; /* transport connection object */
+    Bool local_client;
 } OsCommRec, *OsCommPtr;
 
 extern int FlushClient(
@@ -239,6 +240,9 @@ typedef long int fd_mask;
 #define ffs mffs
 extern int mffs(fd_mask);
 
+/* in access.c */
+extern Bool ComputeLocalClient(ClientPtr client);
+
 /* in auth.c */
 extern void GenerateRandomData (int len, char *buf);