1 /*
2  * Copyright (C) 2019 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 
17 package com.android.providers.media.util;
18 
19 import static android.content.ContentResolver.QUERY_ARG_GROUP_COLUMNS;
20 import static android.content.ContentResolver.QUERY_ARG_LIMIT;
21 import static android.content.ContentResolver.QUERY_ARG_OFFSET;
22 import static android.content.ContentResolver.QUERY_ARG_SORT_COLLATION;
23 import static android.content.ContentResolver.QUERY_ARG_SORT_COLUMNS;
24 import static android.content.ContentResolver.QUERY_ARG_SORT_DIRECTION;
25 import static android.content.ContentResolver.QUERY_ARG_SORT_LOCALE;
26 import static android.content.ContentResolver.QUERY_ARG_SQL_GROUP_BY;
27 import static android.content.ContentResolver.QUERY_ARG_SQL_LIMIT;
28 import static android.content.ContentResolver.QUERY_ARG_SQL_SELECTION;
29 import static android.content.ContentResolver.QUERY_ARG_SQL_SELECTION_ARGS;
30 import static android.content.ContentResolver.QUERY_ARG_SQL_SORT_ORDER;
31 import static android.content.ContentResolver.QUERY_SORT_DIRECTION_ASCENDING;
32 import static android.content.ContentResolver.QUERY_SORT_DIRECTION_DESCENDING;
33 
34 import static com.android.providers.media.util.Logging.TAG;
35 
36 import android.content.ContentResolver;
37 import android.content.ContentValues;
38 import android.database.Cursor;
39 import android.database.SQLException;
40 import android.database.sqlite.SQLiteDatabase;
41 import android.database.sqlite.SQLiteStatement;
42 import android.net.Uri;
43 import android.os.Bundle;
44 import android.os.Trace;
45 import android.text.TextUtils;
46 import android.util.ArrayMap;
47 import android.util.Log;
48 
49 import androidx.annotation.NonNull;
50 import androidx.annotation.Nullable;
51 import androidx.annotation.VisibleForTesting;
52 
53 import java.util.Locale;
54 import java.util.function.Consumer;
55 import java.util.function.Function;
56 
57 public class DatabaseUtils {
58     /**
59      * Bind the given selection with the given selection arguments.
60      * <p>
61      * Internally assumes that '?' is only ever used for arguments, and doesn't
62      * appear as a literal or escaped value.
63      * <p>
64      * This method is typically useful for trusted code that needs to cook up a
65      * fully-bound selection.
66      *
67      * @hide
68      */
bindSelection(@ullable String selection, @Nullable Object... selectionArgs)69     public static @Nullable String bindSelection(@Nullable String selection,
70             @Nullable Object... selectionArgs) {
71         if (selection == null) return null;
72         // If no arguments provided, so we can't bind anything
73         if ((selectionArgs == null) || (selectionArgs.length == 0)) return selection;
74         // If no bindings requested, so we can shortcut
75         if (selection.indexOf('?') == -1) return selection;
76 
77         // Track the chars immediately before and after each bind request, to
78         // decide if it needs additional whitespace added
79         char before = ' ';
80         char after = ' ';
81 
82         int argIndex = 0;
83         final int len = selection.length();
84         final StringBuilder res = new StringBuilder(len);
85         for (int i = 0; i < len; ) {
86             char c = selection.charAt(i++);
87             if (c == '?') {
88                 // Assume this bind request is guarded until we find a specific
89                 // trailing character below
90                 after = ' ';
91 
92                 // Sniff forward to see if the selection is requesting a
93                 // specific argument index
94                 int start = i;
95                 for (; i < len; i++) {
96                     c = selection.charAt(i);
97                     if (c < '0' || c > '9') {
98                         after = c;
99                         break;
100                     }
101                 }
102                 if (start != i) {
103                     argIndex = Integer.parseInt(selection.substring(start, i)) - 1;
104                 }
105 
106                 // Manually bind the argument into the selection, adding
107                 // whitespace when needed for clarity
108                 final Object arg = selectionArgs[argIndex++];
109                 if (before != ' ' && before != '=') res.append(' ');
110                 switch (DatabaseUtils.getTypeOfObject(arg)) {
111                     case Cursor.FIELD_TYPE_NULL:
112                         res.append("NULL");
113                         break;
114                     case Cursor.FIELD_TYPE_INTEGER:
115                         res.append(((Number) arg).longValue());
116                         break;
117                     case Cursor.FIELD_TYPE_FLOAT:
118                         res.append(((Number) arg).doubleValue());
119                         break;
120                     case Cursor.FIELD_TYPE_BLOB:
121                         throw new IllegalArgumentException("Blobs not supported");
122                     case Cursor.FIELD_TYPE_STRING:
123                     default:
124                         if (arg instanceof Boolean) {
125                             // Provide compatibility with legacy applications which may pass
126                             // Boolean values in bind args.
127                             res.append(((Boolean) arg).booleanValue() ? 1 : 0);
128                         } else {
129                             res.append('\'');
130                             // Escape single quote character while appending the string.
131                             res.append(arg.toString().replace("'", "''"));
132                             res.append('\'');
133                         }
134                         break;
135                 }
136                 if (after != ' ') res.append(' ');
137             } else {
138                 res.append(c);
139                 before = c;
140             }
141         }
142         return res.toString();
143     }
144 
145     /**
146      * Returns data type of the given object's value.
147      *<p>
148      * Returned values are
149      * <ul>
150      *   <li>{@link Cursor#FIELD_TYPE_NULL}</li>
151      *   <li>{@link Cursor#FIELD_TYPE_INTEGER}</li>
152      *   <li>{@link Cursor#FIELD_TYPE_FLOAT}</li>
153      *   <li>{@link Cursor#FIELD_TYPE_STRING}</li>
154      *   <li>{@link Cursor#FIELD_TYPE_BLOB}</li>
155      *</ul>
156      *</p>
157      *
158      * @param obj the object whose value type is to be returned
159      * @return object value type
160      * @hide
161      */
getTypeOfObject(Object obj)162     public static int getTypeOfObject(Object obj) {
163         if (obj == null) {
164             return Cursor.FIELD_TYPE_NULL;
165         } else if (obj instanceof byte[]) {
166             return Cursor.FIELD_TYPE_BLOB;
167         } else if (obj instanceof Float || obj instanceof Double) {
168             return Cursor.FIELD_TYPE_FLOAT;
169         } else if (obj instanceof Long || obj instanceof Integer
170                 || obj instanceof Short || obj instanceof Byte) {
171             return Cursor.FIELD_TYPE_INTEGER;
172         } else {
173             return Cursor.FIELD_TYPE_STRING;
174         }
175     }
176 
copyFromCursorToContentValues(@onNull String column, @NonNull Cursor cursor, @NonNull ContentValues values)177     public static void copyFromCursorToContentValues(@NonNull String column, @NonNull Cursor cursor,
178             @NonNull ContentValues values) {
179         final int index = cursor.getColumnIndex(column);
180         if (index != -1) {
181             if (cursor.isNull(index)) {
182                 values.putNull(column);
183             } else {
184                 values.put(column, cursor.getString(index));
185             }
186         }
187     }
188 
189     /**
190      * Simple attempt to balance the given SQL expression by adding parenthesis
191      * when needed.
192      * <p>
193      * Since this is only used for recovering from abusive apps, we're not
194      * interested in trying to build a fully valid SQL parser up in Java. It'll
195      * give up when it encounters complex SQL, such as string literals.
196      */
maybeBalance(@ullable String sql)197     public static @Nullable String maybeBalance(@Nullable String sql) {
198         if (sql == null) return null;
199 
200         int count = 0;
201         char literal = '\0';
202         for (int i = 0; i < sql.length(); i++) {
203             final char c = sql.charAt(i);
204 
205             if (c == '\'' || c == '"') {
206                 if (literal == '\0') {
207                     // Start literal
208                     literal = c;
209                 } else if (literal == c) {
210                     // End literal
211                     literal = '\0';
212                 }
213             }
214 
215             if (literal == '\0') {
216                 if (c == '(') {
217                     count++;
218                 } else if (c == ')') {
219                     count--;
220                 }
221             }
222         }
223         while (count > 0) {
224             sql = sql + ")";
225             count--;
226         }
227         while (count < 0) {
228             sql = "(" + sql;
229             count++;
230         }
231         return sql;
232     }
233 
234     /**
235      * {@link ContentResolver} offers several query arguments, ranging from
236      * helpful higher-level concepts like
237      * {@link ContentResolver#QUERY_ARG_GROUP_COLUMNS} to raw SQL like
238      * {@link ContentResolver#QUERY_ARG_SQL_GROUP_BY}. We prefer the
239      * higher-level concepts when defined by the caller, but we'll fall back to
240      * the raw SQL if that's all the caller provided.
241      * <p>
242      * This method will "resolve" all higher-level query arguments into the raw
243      * SQL arguments, giving us easy values to carry over into
244      * {@link SQLiteQueryBuilder}.
245      */
resolveQueryArgs(@onNull Bundle queryArgs, @NonNull Consumer<String> honored, @NonNull Function<String, String> collatorFactory)246     public static void resolveQueryArgs(@NonNull Bundle queryArgs,
247             @NonNull Consumer<String> honored,
248             @NonNull Function<String, String> collatorFactory) {
249         // We're always going to handle selections
250         honored.accept(QUERY_ARG_SQL_SELECTION);
251         honored.accept(QUERY_ARG_SQL_SELECTION_ARGS);
252 
253         resolveGroupBy(queryArgs, honored);
254         resolveSortOrder(queryArgs, honored, collatorFactory);
255         resolveLimit(queryArgs, honored);
256     }
257 
resolveGroupBy(@onNull Bundle queryArgs, @NonNull Consumer<String> honored)258     private static void resolveGroupBy(@NonNull Bundle queryArgs,
259             @NonNull Consumer<String> honored) {
260         final String[] columns = queryArgs.getStringArray(QUERY_ARG_GROUP_COLUMNS);
261         if (columns != null && columns.length != 0) {
262             String groupBy = TextUtils.join(", ", columns);
263             honored.accept(QUERY_ARG_GROUP_COLUMNS);
264 
265             queryArgs.putString(QUERY_ARG_SQL_GROUP_BY, groupBy);
266         } else {
267             honored.accept(QUERY_ARG_SQL_GROUP_BY);
268         }
269     }
270 
resolveSortOrder(@onNull Bundle queryArgs, @NonNull Consumer<String> honored, @NonNull Function<String, String> collatorFactory)271     private static void resolveSortOrder(@NonNull Bundle queryArgs,
272             @NonNull Consumer<String> honored,
273             @NonNull Function<String, String> collatorFactory) {
274         final String[] columns = queryArgs.getStringArray(QUERY_ARG_SORT_COLUMNS);
275         if (columns != null && columns.length != 0) {
276             String sortOrder = TextUtils.join(", ", columns);
277             honored.accept(QUERY_ARG_SORT_COLUMNS);
278 
279             if (queryArgs.containsKey(QUERY_ARG_SORT_LOCALE)) {
280                 final String collatorName = collatorFactory.apply(
281                         queryArgs.getString(QUERY_ARG_SORT_LOCALE));
282                 sortOrder += " COLLATE " + collatorName;
283                 honored.accept(QUERY_ARG_SORT_LOCALE);
284             } else {
285                 // Interpret PRIMARY and SECONDARY collation strength as no-case collation based
286                 // on their javadoc descriptions.
287                 final int collation = queryArgs.getInt(
288                         QUERY_ARG_SORT_COLLATION, java.text.Collator.IDENTICAL);
289                 switch (collation) {
290                     case java.text.Collator.IDENTICAL:
291                         honored.accept(QUERY_ARG_SORT_COLLATION);
292                         break;
293                     case java.text.Collator.PRIMARY:
294                     case java.text.Collator.SECONDARY:
295                         sortOrder += " COLLATE NOCASE";
296                         honored.accept(QUERY_ARG_SORT_COLLATION);
297                         break;
298                 }
299             }
300 
301             final int sortDir = queryArgs.getInt(QUERY_ARG_SORT_DIRECTION, Integer.MIN_VALUE);
302             switch (sortDir) {
303                 case QUERY_SORT_DIRECTION_ASCENDING:
304                     sortOrder += " ASC";
305                     honored.accept(QUERY_ARG_SORT_DIRECTION);
306                     break;
307                 case QUERY_SORT_DIRECTION_DESCENDING:
308                     sortOrder += " DESC";
309                     honored.accept(QUERY_ARG_SORT_DIRECTION);
310                     break;
311             }
312 
313             queryArgs.putString(QUERY_ARG_SQL_SORT_ORDER, sortOrder);
314         } else {
315             honored.accept(QUERY_ARG_SQL_SORT_ORDER);
316         }
317     }
318 
resolveLimit(@onNull Bundle queryArgs, @NonNull Consumer<String> honored)319     private static void resolveLimit(@NonNull Bundle queryArgs,
320             @NonNull Consumer<String> honored) {
321         final int limit = queryArgs.getInt(QUERY_ARG_LIMIT, Integer.MIN_VALUE);
322         if (limit != Integer.MIN_VALUE) {
323             String limitString = Integer.toString(limit);
324             honored.accept(QUERY_ARG_LIMIT);
325 
326             final int offset = queryArgs.getInt(QUERY_ARG_OFFSET, Integer.MIN_VALUE);
327             if (offset != Integer.MIN_VALUE) {
328                 limitString += " OFFSET " + offset;
329                 honored.accept(QUERY_ARG_OFFSET);
330             }
331 
332             queryArgs.putString(QUERY_ARG_SQL_LIMIT, limitString);
333         } else {
334             honored.accept(QUERY_ARG_SQL_LIMIT);
335         }
336     }
337 
338     /**
339      * Gracefully recover from abusive callers that are smashing limits into
340      * {@link Uri}.
341      */
recoverAbusiveLimit(@onNull Uri uri, @NonNull Bundle queryArgs)342     public static void recoverAbusiveLimit(@NonNull Uri uri, @NonNull Bundle queryArgs) {
343         final String origLimit = queryArgs.getString(QUERY_ARG_SQL_LIMIT);
344         final String uriLimit = uri.getQueryParameter("limit");
345 
346         if (!TextUtils.isEmpty(uriLimit)) {
347             // Yell if we already had a group by requested
348             if (!TextUtils.isEmpty(origLimit)) {
349                 throw new IllegalArgumentException(
350                         "Abusive '" + uriLimit + "' conflicts with requested '" + origLimit + "'");
351             }
352 
353             Log.w(TAG, "Recovered abusive '" + uriLimit + "' from '" + uri + "'");
354 
355             queryArgs.putString(QUERY_ARG_SQL_LIMIT, uriLimit);
356         }
357     }
358 
359     /**
360      * Gracefully recover from abusive callers that are smashing invalid
361      * {@code GROUP BY} clauses into {@code WHERE} clauses.
362      */
recoverAbusiveSelection(@onNull Bundle queryArgs)363     public static void recoverAbusiveSelection(@NonNull Bundle queryArgs) {
364         final String origSelection = queryArgs.getString(QUERY_ARG_SQL_SELECTION);
365         final String origGroupBy = queryArgs.getString(QUERY_ARG_SQL_GROUP_BY);
366 
367         final int index = (origSelection != null)
368                 ? origSelection.toUpperCase(Locale.ROOT).indexOf(" GROUP BY ") : -1;
369         if (index != -1) {
370             String selection = origSelection.substring(0, index);
371             String groupBy = origSelection.substring(index + " GROUP BY ".length());
372 
373             // Try balancing things out
374             selection = maybeBalance(selection);
375             groupBy = maybeBalance(groupBy);
376 
377             // Yell if we already had a group by requested
378             if (!TextUtils.isEmpty(origGroupBy)) {
379                 throw new IllegalArgumentException(
380                         "Abusive '" + groupBy + "' conflicts with requested '" + origGroupBy + "'");
381             }
382 
383             Log.w(TAG, "Recovered abusive '" + selection + "' and '" + groupBy + "' from '"
384                     + origSelection + "'");
385 
386             queryArgs.putString(QUERY_ARG_SQL_SELECTION, selection);
387             queryArgs.putString(QUERY_ARG_SQL_GROUP_BY, groupBy);
388         }
389     }
390 
391     /**
392      * Gracefully recover from abusive callers that are smashing limits into
393      * {@code ORDER BY} clauses.
394      */
recoverAbusiveSortOrder(@onNull Bundle queryArgs)395     public static void recoverAbusiveSortOrder(@NonNull Bundle queryArgs) {
396         final String origSortOrder = queryArgs.getString(QUERY_ARG_SQL_SORT_ORDER);
397         final String origLimit = queryArgs.getString(QUERY_ARG_SQL_LIMIT);
398 
399         final int index = (origSortOrder != null)
400                 ? origSortOrder.toUpperCase(Locale.ROOT).indexOf(" LIMIT ") : -1;
401         if (index != -1) {
402             String sortOrder = origSortOrder.substring(0, index);
403             String limit = origSortOrder.substring(index + " LIMIT ".length());
404 
405             // Yell if we already had a limit requested
406             if (!TextUtils.isEmpty(origLimit)) {
407                 throw new IllegalArgumentException(
408                         "Abusive '" + limit + "' conflicts with requested '" + origLimit + "'");
409             }
410 
411             Log.w(TAG, "Recovered abusive '" + sortOrder + "' and '" + limit + "' from '"
412                     + origSortOrder + "'");
413 
414             queryArgs.putString(QUERY_ARG_SQL_SORT_ORDER, sortOrder);
415             queryArgs.putString(QUERY_ARG_SQL_LIMIT, limit);
416         }
417     }
418 
419     /**
420      * Shamelessly borrowed from {@link ContentResolver}.
421      */
createSqlQueryBundle( @ullable String selection, @Nullable String[] selectionArgs, @Nullable String sortOrder)422     public static @Nullable Bundle createSqlQueryBundle(
423             @Nullable String selection,
424             @Nullable String[] selectionArgs,
425             @Nullable String sortOrder) {
426 
427         if (selection == null && selectionArgs == null && sortOrder == null) {
428             return null;
429         }
430 
431         Bundle queryArgs = new Bundle();
432         if (selection != null) {
433             queryArgs.putString(QUERY_ARG_SQL_SELECTION, selection);
434         }
435         if (selectionArgs != null) {
436             queryArgs.putStringArray(QUERY_ARG_SQL_SELECTION_ARGS, selectionArgs);
437         }
438         if (sortOrder != null) {
439             queryArgs.putString(QUERY_ARG_SQL_SORT_ORDER, sortOrder);
440         }
441         return queryArgs;
442     }
443 
getValues(@onNull ContentValues values)444     public static @NonNull ArrayMap<String, Object> getValues(@NonNull ContentValues values) {
445         final ArrayMap<String, Object> res = new ArrayMap<>();
446         for (String key : values.keySet()) {
447             res.put(key, values.get(key));
448         }
449         return res;
450     }
451 
executeInsert(@onNull SQLiteDatabase db, @NonNull String sql, @Nullable Object[] bindArgs)452     public static long executeInsert(@NonNull SQLiteDatabase db, @NonNull String sql,
453             @Nullable Object[] bindArgs) throws SQLException {
454         Trace.beginSection("executeInsert");
455         try (SQLiteStatement st = db.compileStatement(sql)) {
456             bindArgs(st, bindArgs);
457             return st.executeInsert();
458         } finally {
459             Trace.endSection();
460         }
461     }
462 
executeUpdateDelete(@onNull SQLiteDatabase db, @NonNull String sql, @Nullable Object[] bindArgs)463     public static int executeUpdateDelete(@NonNull SQLiteDatabase db, @NonNull String sql,
464             @Nullable Object[] bindArgs) throws SQLException {
465         Trace.beginSection("executeUpdateDelete");
466         try (SQLiteStatement st = db.compileStatement(sql)) {
467             bindArgs(st, bindArgs);
468             return st.executeUpdateDelete();
469         } finally {
470             Trace.endSection();
471         }
472     }
473 
bindArgs(@onNull SQLiteStatement st, @Nullable Object[] bindArgs)474     private static void bindArgs(@NonNull SQLiteStatement st, @Nullable Object[] bindArgs) {
475         if (bindArgs == null) return;
476 
477         for (int i = 0; i < bindArgs.length; i++) {
478             final Object bindArg = bindArgs[i];
479             switch (getTypeOfObject(bindArg)) {
480                 case Cursor.FIELD_TYPE_NULL:
481                     st.bindNull(i + 1);
482                     break;
483                 case Cursor.FIELD_TYPE_INTEGER:
484                     st.bindLong(i + 1, ((Number) bindArg).longValue());
485                     break;
486                 case Cursor.FIELD_TYPE_FLOAT:
487                     st.bindDouble(i + 1, ((Number) bindArg).doubleValue());
488                     break;
489                 case Cursor.FIELD_TYPE_BLOB:
490                     st.bindBlob(i + 1, (byte[]) bindArg);
491                     break;
492                 case Cursor.FIELD_TYPE_STRING:
493                 default:
494                     if (bindArg instanceof Boolean) {
495                         // Provide compatibility with legacy
496                         // applications which may pass Boolean values in
497                         // bind args.
498                         st.bindLong(i + 1, ((Boolean) bindArg).booleanValue() ? 1 : 0);
499                     } else {
500                         st.bindString(i + 1, bindArg.toString());
501                     }
502                     break;
503             }
504         }
505     }
506 
bindList(@onNull Object... args)507     public static @NonNull String bindList(@NonNull Object... args) {
508         final StringBuilder sb = new StringBuilder();
509         sb.append('(');
510         for (int i = 0; i < args.length; i++) {
511             sb.append('?');
512             if (i < args.length - 1) {
513                 sb.append(',');
514             }
515         }
516         sb.append(')');
517         return DatabaseUtils.bindSelection(sb.toString(), args);
518     }
519 
520     /**
521      * Escape the given argument for use in a {@code LIKE} statement.
522      */
escapeForLike(@onNull String arg)523     public static String escapeForLike(@NonNull String arg) {
524         final StringBuilder sb = new StringBuilder();
525         for (int i = 0; i < arg.length(); i++) {
526             final char c = arg.charAt(i);
527             switch (c) {
528                 case '%': sb.append('\\');
529                     break;
530                 case '_': sb.append('\\');
531                     break;
532             }
533             sb.append(c);
534         }
535         return sb.toString();
536     }
537 
parseBoolean(@ullable Object value, boolean def)538     public static boolean parseBoolean(@Nullable Object value, boolean def) {
539         if (value instanceof Boolean) {
540             return (Boolean) value;
541         } else if (value instanceof Number) {
542             return ((Number) value).intValue() != 0;
543         } else if (value instanceof String) {
544             final String stringValue = ((String) value).toLowerCase(Locale.ROOT);
545             return (!"false".equals(stringValue) && !"0".equals(stringValue));
546         } else {
547             return def;
548         }
549     }
550 
getAsBoolean(@onNull Bundle extras, @NonNull String key, boolean def)551     public static boolean getAsBoolean(@NonNull Bundle extras,
552             @NonNull String key, boolean def) {
553         return parseBoolean(extras.get(key), def);
554     }
555 
getAsBoolean(@onNull ContentValues values, @NonNull String key, boolean def)556     public static boolean getAsBoolean(@NonNull ContentValues values,
557             @NonNull String key, boolean def) {
558         return parseBoolean(values.get(key), def);
559     }
560 
getAsLong(@onNull ContentValues values, @NonNull String key, long def)561     public static long getAsLong(@NonNull ContentValues values,
562             @NonNull String key, long def) {
563         final Long value = values.getAsLong(key);
564         return (value != null) ? value : def;
565     }
566 }
567