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1 /*
2  * Copyright (C) 2013 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package com.android.nfc.cardemulation;
17 
18 import android.util.Log;
19 import android.util.SparseArray;
20 
21 import com.android.nfc.NfcService;
22 
23 import java.io.FileDescriptor;
24 import java.io.PrintWriter;
25 import java.util.Arrays;
26 import java.util.ArrayList;
27 import java.util.HashMap;
28 import java.util.HashSet;
29 import java.util.Map;
30 import java.util.Set;
31 
32 import android.util.StatsLog;
33 
34 public class AidRoutingManager {
35 
36     static final String TAG = "AidRoutingManager";
37 
38     static final boolean DBG = false;
39 
40     static final int ROUTE_HOST = 0x00;
41 
42     // Every routing table entry is matched exact
43     static final int AID_MATCHING_EXACT_ONLY = 0x00;
44     // Every routing table entry can be matched either exact or prefix
45     static final int AID_MATCHING_EXACT_OR_PREFIX = 0x01;
46     // Every routing table entry is matched as a prefix
47     static final int AID_MATCHING_PREFIX_ONLY = 0x02;
48     // Every routing table entry can be matched either exact or prefix or subset only
49     static final int AID_MATCHING_EXACT_OR_SUBSET_OR_PREFIX = 0x03;
50 
51     int mDefaultIsoDepRoute;
52     //Let mDefaultRoute as default aid route
53     int mDefaultRoute;
54 
55     int mMaxAidRoutingTableSize;
56 
57     final byte[] mOffHostRouteUicc;
58     final byte[] mOffHostRouteEse;
59     // Used for backward compatibility in case application doesn't specify the
60     // SE
61     final int mDefaultOffHostRoute;
62 
63     // How the NFC controller can match AIDs in the routing table;
64     // see AID_MATCHING constants
65     final int mAidMatchingSupport;
66 
67     final Object mLock = new Object();
68 
69     // mAidRoutingTable contains the current routing table. The index is the route ID.
70     // The route can include routes to a eSE/UICC.
71     SparseArray<Set<String>> mAidRoutingTable =
72             new SparseArray<Set<String>>();
73 
74     // Easy look-up what the route is for a certain AID
75     HashMap<String, Integer> mRouteForAid = new HashMap<String, Integer>();
76 
doGetDefaultRouteDestination()77     private native int doGetDefaultRouteDestination();
doGetDefaultOffHostRouteDestination()78     private native int doGetDefaultOffHostRouteDestination();
doGetOffHostUiccDestination()79     private native byte[] doGetOffHostUiccDestination();
doGetOffHostEseDestination()80     private native byte[] doGetOffHostEseDestination();
doGetAidMatchingMode()81     private native int doGetAidMatchingMode();
doGetDefaultIsoDepRouteDestination()82     private native int doGetDefaultIsoDepRouteDestination();
83 
84     final class AidEntry {
85         boolean isOnHost;
86         String offHostSE;
87         int route;
88         int aidInfo;
89     }
90 
AidRoutingManager()91     public AidRoutingManager() {
92         mDefaultRoute = doGetDefaultRouteDestination();
93         if (DBG)
94             Log.d(TAG, "mDefaultRoute=0x" + Integer.toHexString(mDefaultRoute));
95         mDefaultOffHostRoute = doGetDefaultOffHostRouteDestination();
96         if (DBG)
97             Log.d(TAG, "mDefaultOffHostRoute=0x" + Integer.toHexString(mDefaultOffHostRoute));
98         mOffHostRouteUicc = doGetOffHostUiccDestination();
99         if (DBG)
100             Log.d(TAG, "mOffHostRouteUicc=" + Arrays.toString(mOffHostRouteUicc));
101         mOffHostRouteEse = doGetOffHostEseDestination();
102         if (DBG)
103           Log.d(TAG, "mOffHostRouteEse=" + Arrays.toString(mOffHostRouteEse));
104         mAidMatchingSupport = doGetAidMatchingMode();
105         if (DBG) Log.d(TAG, "mAidMatchingSupport=0x" + Integer.toHexString(mAidMatchingSupport));
106 
107         mDefaultIsoDepRoute = doGetDefaultIsoDepRouteDestination();
108         if (DBG) Log.d(TAG, "mDefaultIsoDepRoute=0x" + Integer.toHexString(mDefaultIsoDepRoute));
109     }
110 
supportsAidPrefixRouting()111     public boolean supportsAidPrefixRouting() {
112         return mAidMatchingSupport == AID_MATCHING_EXACT_OR_PREFIX ||
113                 mAidMatchingSupport == AID_MATCHING_PREFIX_ONLY ||
114                  mAidMatchingSupport == AID_MATCHING_EXACT_OR_SUBSET_OR_PREFIX;
115     }
116 
supportsAidSubsetRouting()117     public boolean supportsAidSubsetRouting() {
118         return mAidMatchingSupport == AID_MATCHING_EXACT_OR_SUBSET_OR_PREFIX;
119     }
120 
calculateAidRouteSize(HashMap<String, AidEntry> routeCache)121     public int calculateAidRouteSize(HashMap<String, AidEntry> routeCache) {
122         // TAG + ROUTE + LENGTH_BYTE + POWER
123         int AID_HDR_LENGTH = 0x04;
124         int routeTableSize = 0x00;
125         for(Map.Entry<String, AidEntry> aidEntry : routeCache.entrySet()) {
126             String aid = aidEntry.getKey();
127             // removing prefix length
128             if(aid.endsWith("*")) {
129                 routeTableSize += ((aid.length() - 0x01) / 0x02) + AID_HDR_LENGTH;
130             } else {
131                 routeTableSize += (aid.length() / 0x02)+ AID_HDR_LENGTH;
132             }
133         }
134         if (DBG) Log.d(TAG, "calculateAidRouteSize: " + routeTableSize);
135         return routeTableSize;
136     }
137 
clearNfcRoutingTableLocked()138     private void clearNfcRoutingTableLocked() {
139         for (Map.Entry<String, Integer> aidEntry : mRouteForAid.entrySet())  {
140             String aid = aidEntry.getKey();
141             if (aid.endsWith("*")) {
142                 if (mAidMatchingSupport == AID_MATCHING_EXACT_ONLY) {
143                     Log.e(TAG, "Device does not support prefix AIDs but AID [" + aid
144                             + "] is registered");
145                 } else if (mAidMatchingSupport == AID_MATCHING_PREFIX_ONLY) {
146                     if (DBG) Log.d(TAG, "Unrouting prefix AID " + aid);
147                     // Cut off '*' since controller anyway treats all AIDs as a prefix
148                     aid = aid.substring(0, aid.length() - 1);
149                 } else if (mAidMatchingSupport == AID_MATCHING_EXACT_OR_PREFIX ||
150                     mAidMatchingSupport == AID_MATCHING_EXACT_OR_SUBSET_OR_PREFIX) {
151                     aid = aid.substring(0, aid.length() - 1);
152                     if (DBG) Log.d(TAG, "Unrouting prefix AID " + aid);
153                 }
154             }  else if (aid.endsWith("#")) {
155                 if (mAidMatchingSupport == AID_MATCHING_EXACT_ONLY) {
156                     Log.e(TAG, "Device does not support subset AIDs but AID [" + aid
157                             + "] is registered");
158                 } else if (mAidMatchingSupport == AID_MATCHING_PREFIX_ONLY ||
159                     mAidMatchingSupport == AID_MATCHING_EXACT_OR_PREFIX) {
160                     Log.e(TAG, "Device does not support subset AIDs but AID [" + aid
161                             + "] is registered");
162                 } else if (mAidMatchingSupport == AID_MATCHING_EXACT_OR_SUBSET_OR_PREFIX) {
163                     if (DBG) Log.d(TAG, "Unrouting subset AID " + aid);
164                     aid = aid.substring(0, aid.length() - 1);
165                 }
166             } else {
167                 if (DBG) Log.d(TAG, "Unrouting exact AID " + aid);
168             }
169 
170             NfcService.getInstance().unrouteAids(aid);
171         }
172         if(NfcService.getInstance().getNciVersion() != NfcService.getInstance().NCI_VERSION_1_0) {
173           // unRoute EmptyAid
174           NfcService.getInstance().unrouteAids("");
175         }
176     }
177 
getRouteForSecureElement(String se)178     private int getRouteForSecureElement(String se) {
179         if (se == null || se.length() <= 3) {
180             return 0;
181         }
182         try {
183             if (se.startsWith("eSE") && mOffHostRouteEse != null) {
184                 int index = Integer.parseInt(se.substring(3));
185                 if (mOffHostRouteEse.length >= index && index > 0) {
186                     return mOffHostRouteEse[index - 1] & 0xFF;
187                 }
188             } else if (se.startsWith("SIM") && mOffHostRouteUicc != null) {
189                 int index = Integer.parseInt(se.substring(3));
190                 if (mOffHostRouteUicc.length >= index && index > 0) {
191                     return mOffHostRouteUicc[index - 1] & 0xFF;
192                 }
193             }
194             if (mOffHostRouteEse == null && mOffHostRouteUicc == null)
195               return mDefaultOffHostRoute;
196         } catch (NumberFormatException e) { }
197         return 0;
198     }
199 
configureRouting(HashMap<String, AidEntry> aidMap, boolean force)200     public boolean configureRouting(HashMap<String, AidEntry> aidMap, boolean force) {
201         boolean aidRouteResolved = false;
202         HashMap<String, AidEntry> aidRoutingTableCache = new HashMap<String, AidEntry>(aidMap.size());
203         ArrayList<Integer> seList = new ArrayList<Integer>();
204         seList.add(ROUTE_HOST);
205 
206         SparseArray<Set<String>> aidRoutingTable = new SparseArray<Set<String>>(aidMap.size());
207         HashMap<String, Integer> routeForAid = new HashMap<String, Integer>(aidMap.size());
208         HashMap<String, Integer> infoForAid = new HashMap<String, Integer>(aidMap.size());
209         // Then, populate internal data structures first
210         for (Map.Entry<String, AidEntry> aidEntry : aidMap.entrySet())  {
211             int route = ROUTE_HOST;
212             if (!aidEntry.getValue().isOnHost) {
213                 String offHostSE = aidEntry.getValue().offHostSE;
214                 if (offHostSE == null) {
215                     route = mDefaultOffHostRoute;
216                 } else {
217                     route = getRouteForSecureElement(offHostSE);
218                     if (route == 0) {
219                         Log.e(TAG, "Invalid Off host Aid Entry " + offHostSE);
220                         continue;
221                     }
222                 }
223             }
224             if (!seList.contains(route))
225                 seList.add(route);
226             aidEntry.getValue().route = route;
227             int aidType = aidEntry.getValue().aidInfo;
228             String aid = aidEntry.getKey();
229             Set<String> entries =
230                     aidRoutingTable.get(route, new HashSet<String>());
231             entries.add(aid);
232             aidRoutingTable.put(route, entries);
233             routeForAid.put(aid, route);
234             infoForAid.put(aid, aidType);
235         }
236 
237         synchronized (mLock) {
238             if (routeForAid.equals(mRouteForAid) && !force) {
239                 if (DBG) Log.d(TAG, "Routing table unchanged, not updating");
240                 return false;
241             }
242 
243             // Otherwise, update internal structures and commit new routing
244             clearNfcRoutingTableLocked();
245             mRouteForAid = routeForAid;
246             mAidRoutingTable = aidRoutingTable;
247 
248             mMaxAidRoutingTableSize = NfcService.getInstance().getAidRoutingTableSize();
249             if (DBG) Log.d(TAG, "mMaxAidRoutingTableSize: " + mMaxAidRoutingTableSize);
250 
251             //calculate AidRoutingTableSize for existing route destination
252             for(int index = 0; index < seList.size(); index ++) {
253               mDefaultRoute = seList.get(index);
254               if(index != 0)
255                 if (DBG) Log.d(TAG, "AidRoutingTable is full, try to switch mDefaultRoute to 0x" + Integer.toHexString(mDefaultRoute));
256 
257               aidRoutingTableCache.clear();
258 
259               if (mAidMatchingSupport == AID_MATCHING_PREFIX_ONLY) {
260                   /* If a non-default route registers an exact AID which is shorter
261                    * than this exact AID, this will create a problem with controllers
262                    * that treat every AID in the routing table as a prefix.
263                    * For example, if App A registers F0000000041010 as an exact AID,
264                    * and App B registers F000000004 as an exact AID, and App B is not
265                    * the default route, the following would be added to the routing table:
266                    * F000000004 -> non-default destination
267                    * However, because in this mode, the controller treats every routing table
268                    * entry as a prefix, it means F0000000041010 would suddenly go to the non-default
269                    * destination too, whereas it should have gone to the default.
270                    *
271                    * The only way to prevent this is to add the longer AIDs of the
272                    * default route at the top of the table, so they will be matched first.
273                    */
274                   Set<String> defaultRouteAids = mAidRoutingTable.get(mDefaultRoute);
275                   if (defaultRouteAids != null) {
276                       for (String defaultRouteAid : defaultRouteAids) {
277                           // Check whether there are any shorted AIDs routed to non-default
278                           // TODO this is O(N^2) run-time complexity...
279                           for (Map.Entry<String, Integer> aidEntry : mRouteForAid.entrySet()) {
280                               String aid = aidEntry.getKey();
281                               int route = aidEntry.getValue();
282                               if (defaultRouteAid.startsWith(aid) && route != mDefaultRoute) {
283                                   if (DBG) Log.d(TAG, "Adding AID " + defaultRouteAid + " for default " +
284                                           "route, because a conflicting shorter AID will be " +
285                                           "added to the routing table");
286                                     aidRoutingTableCache.put(defaultRouteAid, aidMap.get(defaultRouteAid));
287                               }
288                           }
289                       }
290                   }
291               }
292 
293               // Add AID entries for all non-default routes
294               for (int i = 0; i < mAidRoutingTable.size(); i++) {
295                   int route = mAidRoutingTable.keyAt(i);
296                   if (route != mDefaultRoute) {
297                       Set<String> aidsForRoute = mAidRoutingTable.get(route);
298                       for (String aid : aidsForRoute) {
299                           if (aid.endsWith("*")) {
300                               if (mAidMatchingSupport == AID_MATCHING_EXACT_ONLY) {
301                                   Log.e(TAG, "This device does not support prefix AIDs.");
302                               } else if (mAidMatchingSupport == AID_MATCHING_PREFIX_ONLY) {
303                                   if (DBG) Log.d(TAG, "Routing prefix AID " + aid + " to route "
304                                           + Integer.toString(route));
305                                   // Cut off '*' since controller anyway treats all AIDs as a prefix
306                                     aidRoutingTableCache.put(aid.substring(0,aid.length() - 1), aidMap.get(aid));
307                               } else if (mAidMatchingSupport == AID_MATCHING_EXACT_OR_PREFIX ||
308                                 mAidMatchingSupport == AID_MATCHING_EXACT_OR_SUBSET_OR_PREFIX) {
309                                   if (DBG) Log.d(TAG, "Routing prefix AID " + aid + " to route "
310                                           + Integer.toString(route));
311                                   aidRoutingTableCache.put(aid.substring(0,aid.length() - 1), aidMap.get(aid));
312                               }
313                           } else if (aid.endsWith("#")) {
314                               if (mAidMatchingSupport == AID_MATCHING_EXACT_ONLY) {
315                                   Log.e(TAG, "Device does not support subset AIDs but AID [" + aid
316                                           + "] is registered");
317                               } else if (mAidMatchingSupport == AID_MATCHING_PREFIX_ONLY ||
318                                   mAidMatchingSupport == AID_MATCHING_EXACT_OR_PREFIX) {
319                                   Log.e(TAG, "Device does not support subset AIDs but AID [" + aid
320                                           + "] is registered");
321                               } else if (mAidMatchingSupport == AID_MATCHING_EXACT_OR_SUBSET_OR_PREFIX) {
322                                   if (DBG) Log.d(TAG, "Routing subset AID " + aid + " to route "
323                                           + Integer.toString(route));
324                                   aidRoutingTableCache.put(aid.substring(0,aid.length() - 1), aidMap.get(aid));
325                               }
326                          } else {
327                               if (DBG) Log.d(TAG, "Routing exact AID " + aid + " to route "
328                                       + Integer.toString(route));
329                                 aidRoutingTableCache.put(aid, aidMap.get(aid));
330                           }
331                         }
332                  }
333               }
334 
335               if(mDefaultRoute != mDefaultIsoDepRoute) {
336                 if(NfcService.getInstance().getNciVersion() != NfcService.getInstance().NCI_VERSION_1_0) {
337                   String emptyAid = "";
338                   AidEntry entry = new AidEntry();
339                   entry.route = mDefaultRoute;
340                   if(mDefaultRoute==ROUTE_HOST) {
341                     entry.isOnHost = true;
342                   } else{
343                     entry.isOnHost = false;
344                    }
345                   entry.aidInfo = RegisteredAidCache.AID_ROUTE_QUAL_PREFIX;
346                   aidRoutingTableCache.put(emptyAid, entry);
347                   if (DBG) Log.d(TAG, "Add emptyAid into AidRoutingTable");
348                 }
349               }
350 
351               if( calculateAidRouteSize(aidRoutingTableCache) <= mMaxAidRoutingTableSize) {
352                 aidRouteResolved = true;
353                 break;
354               }
355           }
356 
357           if(aidRouteResolved == true) {
358               commit(aidRoutingTableCache);
359           } else {
360               StatsLog.write(StatsLog.NFC_ERROR_OCCURRED, StatsLog.NFC_ERROR_OCCURRED__TYPE__AID_OVERFLOW, 0, 0);
361               Log.e(TAG, "RoutingTable unchanged because it's full, not updating");
362           }
363         }
364         return true;
365     }
366 
commit(HashMap<String, AidEntry> routeCache )367     private void commit(HashMap<String, AidEntry> routeCache ) {
368 
369         if(routeCache != null) {
370 
371             for (Map.Entry<String, AidEntry> aidEntry : routeCache.entrySet())  {
372                 int route = aidEntry.getValue().route;
373                 int aidType = aidEntry.getValue().aidInfo;
374                 String aid = aidEntry.getKey();
375                 if (DBG) Log.d (TAG, "commit aid:"+aid+"route:"+route+"aidtype:"+aidType);
376 
377                 NfcService.getInstance().routeAids(aid, route, aidType);
378             }
379         }
380 
381         // And finally commit the routing
382         NfcService.getInstance().commitRouting();
383     }
384 
385     /**
386      * This notifies that the AID routing table in the controller
387      * has been cleared (usually due to NFC being turned off).
388      */
onNfccRoutingTableCleared()389     public void onNfccRoutingTableCleared() {
390         // The routing table in the controller was cleared
391         // To stay in sync, clear our own tables.
392         synchronized (mLock) {
393             mAidRoutingTable.clear();
394             mRouteForAid.clear();
395         }
396     }
397 
dump(FileDescriptor fd, PrintWriter pw, String[] args)398     public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
399         pw.println("Routing table:");
400         pw.println("    Default route: " + ((mDefaultRoute == 0x00) ? "host" : "secure element"));
401         synchronized (mLock) {
402             for (int i = 0; i < mAidRoutingTable.size(); i++) {
403                 Set<String> aids = mAidRoutingTable.valueAt(i);
404                 pw.println("    Routed to 0x" + Integer.toHexString(mAidRoutingTable.keyAt(i)) + ":");
405                 for (String aid : aids) {
406                     pw.println("        \"" + aid + "\"");
407                 }
408             }
409         }
410     }
411 }
412