1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 1999 by Sun Microsystems, Inc.
23  * All rights reserved.
24  *
25  */
26 
27 //  ServiceLocationManager.java : The service locator object.
28 //  Author:           Erik Guttman
29 //
30 
31 package com.sun.slp;
32 
33 import java.util.*;
34 import java.io.*;
35 import java.lang.reflect.*;
36 
37 /**
38  * The ServiceLocationManager class provides entry to SLP services.
39  * The ServiceLocationManager class uses static methods
40  * to provide objects encapsulating the connection with the Service
41  * Location facility. In addition, it provides access to known
42  * scopes.
43  *
44  * @author Erik Guttman
45  *
46  */
47 
48 abstract public class ServiceLocationManager extends Object {
49 
50     // Properties.
51 
52     protected static DATable dat = null;
53     protected static SLPConfig config = null;
54 
55     protected static Hashtable locators = new Hashtable();
56     protected static Hashtable advertisers = new Hashtable();
57     protected static Class locatorClass = null;
58     protected static Class advertiserClass = null;
59 
60     // Public interface
61 
62     /**
63      * The property accessor for the Locator object. If user agent
64      * functionality is not available, returns null.
65      *
66      * @param locale The Locale of the Locator object. Use null for default.
67      * @return The Locator object.
68      * @exception ServiceLocationException Thrown if the locator can't
69      *					  be created.
70      *
71      */
72 
73     public static Locator getLocator(Locale locale)
74 	throws ServiceLocationException
75     {
76 
77 	if (locale == null) {
78 	    locale = config.getLocale();
79 
80 	}
81 
82 	String lang = locale.getLanguage();
83 	Locator locator = (Locator)locators.get(lang);
84 
85 	if (locator == null) {
86 
87 	    if (locatorClass == null) {
88 		String className =
89 		    System.getProperty("sun.net.slp.LocatorImpl");
90 		if (className == null) {
91 		    className = "com.sun.slp.UARequester";
92 		}
93 		locatorClass = getClass(className);
94 	    }
95 
96 	    locator = (Locator)getInstance(locatorClass, locale);
97 
98 	    if (locator != null) {
99 		locators.put(lang, locator);
100 
101 	    }
102 	}
103 
104 	return locator;
105     }
106 
107     /**
108      * The property accessor for the Advertiser object. If service agent
109      * functionality is not available, returns null.
110      *
111      * @param locale The Locale of the Advertiser object. Use null for default.
112      * @return The Advertiser object.
113      * @exception ServiceLocationException Thrown if the locator can't
114      *					  be created.
115      *
116      */
117 
118     public static Advertiser getAdvertiser(Locale locale)
119 	throws ServiceLocationException {
120 
121 	if (locale == null) {
122 	    locale = config.getLocale();
123 
124 	}
125 
126 	String lang = locale.getLanguage();
127 	Advertiser advertiser = (Advertiser)advertisers.get(lang);
128 
129 	if (advertiser == null) {
130 
131 	    if (advertiserClass == null) {
132 		String className =
133 		    System.getProperty("sun.net.slp.AdvertiserImpl");
134 		if (className == null) {
135 		    className = "com.sun.slp.SARequester";
136 		}
137 		advertiserClass = getClass(className);
138 	    }
139 
140 	    advertiser = (Advertiser)getInstance(advertiserClass, locale);
141 
142 	    if (advertiser != null) {
143 		advertisers.put(lang, advertiser);
144 
145 	    }
146 	}
147 
148 	return advertiser;
149     }
150 
151     /**
152      * Returns a vector of known scope names.  It will include any
153      * scopes defined in the configuration file and ensure that the
154      * <i>order</i> of those scope strings is kept in the list of
155      * scopes which is returned. This method enforces the constraint
156      * that the default scope is returned if no other is available.
157      *
158      * @param typeHint Type to look for if SA advertisment required.
159      * @return Vector containing Strings with scope names.
160      */
161 
162     public static synchronized Vector findScopes()
163 	throws ServiceLocationException {
164 
165 	Vector accessableScopes = null;
166 
167 	// For the UA, return configured scopes if we have them.
168 
169 	accessableScopes = config.getConfiguredScopes();
170 
171 	// If no configured scopes, get discovered scopes from
172 	//  DA table.
173 
174 	if (accessableScopes.size() <= 0) {
175 	    accessableScopes = dat.findScopes();
176 
177 	    // If still none, perform SA discovery.
178 
179 	    if (accessableScopes.size() <= 0) {
180 		accessableScopes = performSADiscovery();
181 
182 		// If still none, then return default scope. The client won`t
183 		//  be able to contact anyone because there`s nobody out there.
184 
185 		if (accessableScopes.size() <= 0) {
186 		    accessableScopes.addElement(Defaults.DEFAULT_SCOPE);
187 
188 		}
189 	    }
190 	}
191 
192 	return accessableScopes;
193     }
194 
195     /**
196      * Returns the maximum across all DAs of the min-refresh-interval
197      * attribute.  This value satisfies the advertised refresh interval
198      * bounds for all DAs, and, if used by the SA, assures that no
199      * refresh registration will be rejected.  If no DA advertises a
200      * min-refresh-interval attribute, a value of 0 is returned.
201      *
202      * @return The maximum min-refresh-interval attribute value.
203      */
204 
205     public static int getRefreshInterval() throws ServiceLocationException {
206 
207 	// Get the min-refresh-interval attribute values for all DA's from
208 	//  the server.
209 
210 	Vector tags = new Vector();
211 	tags.addElement(Defaults.MIN_REFRESH_INTERVAL_ATTR_ID);
212 
213 	// We don't simply do Locator.findAttributes() here because we
214 	//  need to contact the SA server directly.
215 
216 	Vector saOnlyScopes = config.getSAOnlyScopes();
217 
218 	CAttrMsg msg = new CAttrMsg(Defaults.locale,
219 				    Defaults.SUN_DA_SERVICE_TYPE,
220 				    saOnlyScopes,
221 				    tags);
222 
223 	// Send it down the pipe to the IPC process. It's a bad bug
224 	//  if the reply comes back as not a CAttrMsg.
225 
226 	CAttrMsg rply =
227 	    (CAttrMsg)Transact.transactTCPMsg(config.getLoopback(), msg, true);
228 
229 	// Check error code.
230 
231 	if (rply == null ||
232 	    rply.getErrorCode() != ServiceLocationException.OK) {
233 	    short errCode =
234 		(rply == null ?
235 		 ServiceLocationException.INTERNAL_SYSTEM_ERROR :
236 		 rply.getErrorCode());
237 	    throw
238 		new ServiceLocationException(errCode,
239 					     "loopback_error",
240 					     new Object[] {
241 		    new Short(errCode)});
242 
243 	}
244 
245 	// Sort through the attribute values to determine reply.
246 
247 	int ri = 0;
248 	Vector attrs = rply.attrList;
249 	ServiceLocationAttribute attr =
250 	    (attrs.size() > 0 ?
251 	    (ServiceLocationAttribute)attrs.elementAt(0):
252 	    null);
253 	Vector values = (attr != null ? attr.getValues():new Vector());
254 	int i, n = values.size();
255 
256 	for (i = 0; i < n; i++) {
257 	    Integer mri = (Integer)values.elementAt(i);
258 	    int mriv = mri.intValue();
259 
260 	    if (mriv > ri) {
261 		ri = mriv;
262 
263 	    }
264 	}
265 
266 	return ri;
267     }
268 
269     //
270     // Private implementation.
271     //
272 
273     // Return the requested class, or null if it can't be found.
274 
275     private static Class getClass(String name) {
276 
277 	Class ret = null;
278 
279 	try {
280 
281 	    ret = Class.forName(name);
282 
283 	} catch (ClassNotFoundException ex) {
284 
285 	}
286 
287 	return ret;
288 
289     }
290 
291     // Return an instance from the class.
292 
293     private static Object getInstance(Class cobj, Locale locale) {
294 
295 	Object ret = null;
296 
297 	if (cobj != null) {
298 
299 	    try {
300 		Class[] paramClasses = {locale.getClass()};
301 
302 		Constructor con = cobj.getDeclaredConstructor(paramClasses);
303 
304 		Object[] params = {locale};
305 
306 		ret = con.newInstance(params);
307 
308 	    } catch (InstantiationException ex) {
309 
310 	    } catch (IllegalAccessException ex) {
311 
312 	    } catch (InvocationTargetException ex) {
313 
314 	    } catch (NoSuchMethodException ex) {
315 
316 	    }
317 	}
318 
319 	return ret;
320     }
321 
322     // Perform SA discovery, since no DA scopes found.
323 
324     private static Vector performSADiscovery()
325 	throws ServiceLocationException {
326 
327 	// Get type hint if any.
328 
329 	Vector hint = config.getTypeHint();
330 
331 	// Format query.
332 
333 	StringBuffer buf = new StringBuffer();
334 	int i, n = hint.size();
335 
336 	for (i = 0; i < n; i++) {
337 	    buf.append("(");
338 	    buf.append(Defaults.SERVICE_TYPE_ATTR_ID);
339 	    buf.append("=");
340 	    buf.append(hint.elementAt(i).toString());
341 
342 	}
343 
344 	// Add logical disjunction if more than one element.
345 
346 	if (i > 1) {
347 	    buf.insert(0, "(|");
348 	    buf.append(")");
349 	}
350 
351 	// Form SA discovery request.
352 
353 	CSrvMsg rqst = new CSrvMsg(config.getLocale(),
354 				   Defaults.SA_SERVICE_TYPE,
355 				   new Vector(),    // seeking scopes...
356 				   buf.toString());
357 
358 	// Transact the advert request.
359 
360 	Vector scopes =
361 	    Transact.transactActiveAdvertRequest(Defaults.SA_SERVICE_TYPE,
362 						 rqst,
363 						 null);
364 						// DA table not needed...
365 
366 	return scopes;
367 
368     }
369 
370     // Initialize SLPConfig and DATable.
371 
372     static {
373 
374 	if (config == null) {
375 	    config = SLPConfig.getSLPConfig();
376 
377 	}
378 
379 	if (dat == null) {
380 	    dat = DATable.getDATable();
381 
382 	}
383     }
384 }
385