1   /*
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3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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11   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12   * version 2 for more details (a copy is included in the LICENSE file that
13   * accompanied this code).
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23  
24  /*
25   * @test
26   * @bug 6380723
27   * @summary Decode many byte sequences in many ways
28   * @run main/timeout=1800 FindDecoderBugs
29   * @author Martin Buchholz
30   */
31  
32  import java.util.*;
33  import java.util.regex.*;
34  import java.nio.*;
35  import java.nio.charset.*;
36  
37  public class FindDecoderBugs {
38  
39      static boolean isBroken(String csn) {
40          if (csn.equals("x-COMPOUND_TEXT")) return true;
41          return false;
42      }
43  
44      static <T extends Comparable<? super T>> List<T> sort(Collection<T> c) {
45          List<T> list = new ArrayList<T>(c);
46          Collections.sort(list);
47          return list;
48      }
49  
50      static class TooManyFailures extends RuntimeException {
51          private static final long serialVersionUID = 0L;
52      }
53  
54      static String string(byte[] a) {
55          final StringBuilder sb = new StringBuilder();
56          for (byte b : a) {
57              if (sb.length() != 0) sb.append(' ');
58              sb.append(String.format("%02x", b & 0xff));
59          }
60          return sb.toString();
61      }
62  
63      static String string(char[] a) {
64          final StringBuilder sb = new StringBuilder();
65          for (char c : a) {
66              if (sb.length() != 0) sb.append(' ');
67              sb.append(String.format("\\u%04x", (int) c));
68          }
69          return sb.toString();
70      }
71  
72      static class Reporter {
73          // Some machinery to make sure only a small number of errors
74          // that are "too similar" are reported.
75          static class Counts extends HashMap<String, Long> {
76              private static final long serialVersionUID = -1;
77              long inc(String signature) {
78                  Long count = get(signature);
79                  if (count == null) count = 0L;
80                  put(signature, count+1);
81                  return count+1;
82              }
83          }
84  
85          final Counts failureCounts = new Counts();
86          final static long maxFailures = 2;
87  
88          final static Pattern hideBytes = Pattern.compile("\"[0-9a-f ]+\"");
89          final static Pattern hideChars = Pattern.compile("\\\\u[0-9a-f]{4}");
90  
91          boolean bug(String format, Object... args) {
92              String signature = String.format(format, args);
93              signature = hideBytes.matcher(signature).replaceAll("\"??\"");
94              signature = hideChars.matcher(signature).replaceAll("\\u????");
95              failed++;
96              if (failureCounts.inc(signature) <= maxFailures) {
97                  System.out.printf(format, args);
98                  System.out.println();
99                  return true;
100             }
101             return false;
102         }
103 
104         void summarize() {
105             for (String key : sort(failureCounts.keySet()))
106                 System.out.printf("-----%n%s%nfailures=%d%n",
107                                   key, failureCounts.get(key));
108         }
109     }
110 
111     static final Reporter reporter = new Reporter();
112 
113     static class Result {
114         final int limit;
115         final int ipos;
116         final boolean direct;
117         final byte[] ia;
118         final char[] oa;
119         final CoderResult cr;
120 
121         Result(ByteBuffer ib, CharBuffer ob, CoderResult cr) {
122             ipos = ib.position();
123             ia = toArray(ib);
124             oa = toArray(ob);
125             direct = ib.isDirect();
126             limit = ob.limit();
127             this.cr = cr;
128         }
129 
130         static byte[] toArray(ByteBuffer b) {
131             int pos = b.position();
132             byte[] a = new byte[b.limit()];
133             b.position(0);
134             b.get(a);
135             b.position(pos);
136             return a;
137         }
138 
139         static char[] toArray(CharBuffer b) {
140             char[] a = new char[b.position()];
141             b.position(0);
142             b.get(a);
143             return a;
144         }
145 
146         static boolean eq(Result x, Result y) {
147             return x == y ||
148                 (x != null && y != null &&
149                  (Arrays.equals(x.oa, y.oa) &&
150                   x.ipos == y.ipos &&
151                   x.cr == y.cr));
152         }
153 
154         public String toString() {
155             return String.format("\"%s\"[%d/%d] => %s \"%s\"[%d/%d]%s",
156                                  string(ia), ipos, ia.length,
157                                  cr, string(oa), oa.length, limit,
158                                  (direct ? " (direct)" : ""));
159         }
160     }
161 
162     // legend: r=regular d=direct In=Input Ou=Output
163     static final int maxBufSize = 20;
164     static final ByteBuffer[] ribs = new ByteBuffer[maxBufSize];
165     static final ByteBuffer[] dibs = new ByteBuffer[maxBufSize];
166 
167     static final CharBuffer[] robs = new CharBuffer[maxBufSize];
168     static final CharBuffer[] dobs = new CharBuffer[maxBufSize];
169     static {
170         for (int i = 0; i < maxBufSize; i++) {
171             ribs[i] = ByteBuffer.allocate(i);
172             dibs[i] = ByteBuffer.allocateDirect(i);
173             robs[i] = CharBuffer.allocate(i);
174             dobs[i] = ByteBuffer.allocateDirect(i*2).asCharBuffer();
175         }
176     }
177 
178     static class CharsetTester {
179         private final Charset cs;
180         private static final long maxFailures = 5;
181         private long failures = 0;
182         // private static final long maxCharsetFailures = Long.MAX_VALUE;
183         private static final long maxCharsetFailures = 10000L;
184         private final long failed0 = failed;
185 
186         CharsetTester(Charset cs) {
187             this.cs = cs;
188         }
189 
190         static boolean bug(String format, Object... args) {
191             return reporter.bug(format, args);
192         }
193 
194         Result recode(ByteBuffer ib, CharBuffer ob) {
195             try {
196                 char canary = '\u4242';
197                 ib.clear();     // Prepare to read
198                 ob.clear();     // Prepare to write
199                 for (int i = 0; i < ob.limit(); i++)
200                     ob.put(i, canary);
201                 CharsetDecoder coder = cs.newDecoder();
202                 CoderResult cr = coder.decode(ib, ob, false);
203                 equal(ib.limit(), ib.capacity());
204                 equal(ob.limit(), ob.capacity());
205                 Result r = new Result(ib, ob, cr);
206                 if (cr.isError())
207                     check(cr.length() > 0);
208                 if (cr.isOverflow() && ob.remaining() > 10)
209                     bug("OVERFLOW, but there's lots of room: %s %s",
210                         cs, r);
211 //              if (cr.isOverflow() && ib.remaining() == 0)
212 //                  bug("OVERFLOW, yet remaining() == 0: %s %s",
213 //                      cs, r);
214                 if (cr.isError() && ib.remaining() < cr.length())
215                     bug("remaining() < CoderResult.length(): %s %s",
216                         cs, r);
217 //              if (ib.position() == 0 && ob.position() > 0)
218 //                  reporter. bug("output only if input consumed: %s %s",
219 //                                cs, r);
220                 // Should we warn if cr.isUnmappable() ??
221                 CoderResult cr2 = coder.decode(ib, ob, false);
222                 if (ib.position() != r.ipos ||
223                     ob.position() != r.oa.length ||
224                     cr != cr2)
225                     bug("Coding operation not idempotent: %s%n    %s%n    %s",
226                         cs, r, new Result(ib, ob, cr2));
227                 if (ob.position() < ob.limit() &&
228                     ob.get(ob.position()) != canary)
229                     bug("Buffer overrun: %s %s %s",
230                         cs, r, ob.get(ob.position()));
231                 return r;
232             } catch (Throwable t) {
233                 if (bug("Unexpected exception: %s %s %s",
234                         cs, t.getClass().getSimpleName(),
235                         new Result(ib, ob, null)))
236                     t.printStackTrace();
237                 return null;
238             }
239         }
240 
241         Result recode2(byte[] ia, int n) {
242             int len = ia.length;
243             ByteBuffer rib = ByteBuffer.wrap(ia);
244             ByteBuffer dib = dibs[len];
245             dib.clear(); dib.put(ia); dib.clear();
246             CharBuffer rob = robs[n];
247             CharBuffer dob = dobs[n];
248             equal(rob.limit(), n);
249             equal(dob.limit(), n);
250             check(dib.isDirect());
251             check(dob.isDirect());
252             Result r1 = recode(rib, rob);
253             Result r2 = recode(dib, dob);
254             if (r1 != null && r2 != null && ! Result.eq(r1, r2))
255                 bug("Results differ for direct buffers: %s%n    %s%n    %s",
256                     cs, r1, r2);
257             return r1;
258         }
259 
260         Result test(byte[] ia) {
261             if (failed - failed0 >= maxCharsetFailures)
262                 throw new TooManyFailures();
263 
264             Result roomy = recode2(ia, maxBufSize - 1);
265             if (roomy == null) return roomy;
266             int olen = roomy.oa.length;
267             if (olen > 0) {
268                 if (roomy.ipos == roomy.ia.length) {
269                     Result perfectFit = recode2(ia, olen);
270                     if (! Result.eq(roomy, perfectFit))
271                         bug("Results differ: %s%n    %s%n    %s",
272                             cs, roomy, perfectFit);
273                 }
274                 for (int i = 0; i < olen; i++) {
275                     Result claustrophobic = recode2(ia, i);
276                     if (claustrophobic == null) return roomy;
277                     if (roomy.cr.isUnderflow() &&
278                         ! claustrophobic.cr.isOverflow())
279                         bug("Expected OVERFLOW: %s%n    %s%n    %s",
280                             cs, roomy, claustrophobic);
281                 }
282             }
283             return roomy;
284         }
285 
286         void testExhaustively(byte[] prefix, int n) {
287             int len = prefix.length;
288             byte[] ia = Arrays.copyOf(prefix, len + 1);
289             for (int i = 0; i < 0x100; i++) {
290                 ia[len] = (byte) i;
291                 if (n == 1)
292                     test(ia);
293                 else
294                     testExhaustively(ia, n - 1);
295             }
296         }
297 
298         void testRandomly(byte[] prefix, int n) {
299             int len = prefix.length;
300             byte[] ia = Arrays.copyOf(prefix, len + n);
301             for (int i = 0; i < 5000; i++) {
302                 for (int j = 0; j < n; j++)
303                     ia[len + j] = randomByte();
304                 test(ia);
305             }
306         }
307 
308         void testPrefix(byte[] prefix) {
309             if (prefix.length > 0)
310                 System.out.printf("Testing prefix %s%n", string(prefix));
311 
312             test(prefix);
313 
314             testExhaustively(prefix, 1);
315             testExhaustively(prefix, 2);
316             // Can you spare a week of CPU time?
317             // testExhaustively(cs, tester, prefix, 3);
318 
319             testRandomly(prefix, 3);
320             testRandomly(prefix, 4);
321         }
322     }
323 
324     private final static Random rnd = new Random();
325     private static byte randomByte() {
326         return (byte) rnd.nextInt(0x100);
327     }
328     private static byte[] randomBytes(int len) {
329         byte[] a = new byte[len];
330         for (int i = 0; i < len; i++)
331             a[i] = randomByte();
332         return a;
333     }
334 
335     private static final byte SS2 = (byte) 0x8e;
336     private static final byte SS3 = (byte) 0x8f;
337     private static final byte ESC = (byte) 0x1b;
338     private static final byte SO  = (byte) 0x0e;
339     private static final byte SI  = (byte) 0x0f;
340 
341     private final static byte[][] stateChangers = {
342         {SS2}, {SS3}, {SO}, {SI}
343     };
344 
345     private final static byte[][]escapeSequences = {
346         {ESC, '(', 'B'},
347         {ESC, '(', 'I'},
348         {ESC, '(', 'J'},
349         {ESC, '$', '@'},
350         {ESC, '$', 'A'},
351         {ESC, '$', ')', 'A'},
352         {ESC, '$', ')', 'C'},
353         {ESC, '$', ')', 'G'},
354         {ESC, '$', '*', 'H'},
355         {ESC, '$', '+', 'I'},
356         {ESC, '$', 'B'},
357         {ESC, 'N'},
358         {ESC, 'O'},
359         {ESC, '$', '(', 'D'},
360     };
361 
362     private static boolean isStateChanger(Charset cs, byte[] ia) {
363         Result r = new CharsetTester(cs).recode2(ia, 9);
364         return r == null ? false :
365             (r.cr.isUnderflow() &&
366              r.ipos == ia.length &&
367              r.oa.length == 0);
368     }
369 
370     private final static byte[][] incompletePrefixes = {
371         {ESC},
372         {ESC, '('},
373         {ESC, '$'},
374         {ESC, '$', '(',},
375     };
376 
377     private static boolean isIncompletePrefix(Charset cs, byte[] ia) {
378         Result r = new CharsetTester(cs).recode2(ia, 9);
379         return r == null ? false :
380             (r.cr.isUnderflow() &&
381              r.ipos == 0 &&
382              r.oa.length == 0);
383     }
384 
385     private static void testCharset(Charset cs) throws Throwable {
386         final String csn = cs.name();
387 
388         if (isBroken(csn)) {
389             System.out.printf("Skipping possibly broken charset %s%n", csn);
390             return;
391         }
392         System.out.println(csn);
393         CharsetTester tester = new CharsetTester(cs);
394 
395         tester.testPrefix(new byte[0]);
396 
397         if (! csn.matches("(?:x-)?(?:UTF|JIS(?:_X)?0).*")) {
398             for (byte[] prefix : stateChangers)
399                 if (isStateChanger(cs, prefix))
400                     tester.testPrefix(prefix);
401 
402             for (byte[] prefix : incompletePrefixes)
403                 if (isIncompletePrefix(cs, prefix))
404                     tester.testPrefix(prefix);
405 
406             if (isIncompletePrefix(cs, new byte[] {ESC}))
407                 for (byte[] prefix : escapeSequences)
408                     if (isStateChanger(cs, prefix))
409                         tester.testPrefix(prefix);
410         }
411     }
412 
413     private static void realMain(String[] args) {
414         for (Charset cs : sort(Charset.availableCharsets().values())) {
415             try {
416                 testCharset(cs);
417             } catch (TooManyFailures e) {
418                 System.out.printf("Too many failures for %s%n", cs);
419             } catch (Throwable t) {
420                 unexpected(t);
421             }
422         }
423         reporter.summarize();
424     }
425 
426     //--------------------- Infrastructure ---------------------------
427     static volatile long passed = 0, failed = 0;
428     static void pass() {passed++;}
429     static void fail() {failed++; Thread.dumpStack();}
430     static void fail(String format, Object... args) {
431         System.out.println(String.format(format, args)); failed++;}
432     static void fail(String msg) {System.out.println(msg); fail();}
433     static void unexpected(Throwable t) {failed++; t.printStackTrace();}
434     static void check(boolean cond) {if (cond) pass(); else fail();}
435     static void equal(Object x, Object y) {
436         if (x == null ? y == null : x.equals(y)) pass();
437         else fail(x + " not equal to " + y);}
438     static void equal(int x, int y) {
439         if (x == y) pass();
440         else fail(x + " not equal to " + y);}
441     public static void main(String[] args) throws Throwable {
442         try {realMain(args);} catch (Throwable t) {unexpected(t);}
443         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
444         if (failed > 0) throw new AssertionError("Some tests failed");}
445 }