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-rw-r--r--src/com/android/providers/downloads/Helpers.java262
1 files changed, 1 insertions, 261 deletions
diff --git a/src/com/android/providers/downloads/Helpers.java b/src/com/android/providers/downloads/Helpers.java
index 565aa52e..226fb481 100644
--- a/src/com/android/providers/downloads/Helpers.java
+++ b/src/com/android/providers/downloads/Helpers.java
@@ -62,6 +62,7 @@ import java.io.IOException;
import java.util.ArrayList;
import java.util.Random;
import java.util.Set;
+import java.util.function.BiConsumer;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
@@ -679,265 +680,4 @@ public class Helpers {
// For permission related purposes, any package belonging to the given uid should work.
return packages[0];
}
-
- /**
- * Checks whether this looks like a legitimate selection parameter
- */
- public static void validateSelection(String selection, Set<String> allowedColumns) {
- try {
- if (selection == null || selection.isEmpty()) {
- return;
- }
- Lexer lexer = new Lexer(selection, allowedColumns);
- parseExpression(lexer);
- if (lexer.currentToken() != Lexer.TOKEN_END) {
- throw new IllegalArgumentException("syntax error");
- }
- } catch (RuntimeException ex) {
- if (Constants.LOGV) {
- Log.d(Constants.TAG, "invalid selection [" + selection + "] triggered " + ex);
- } else if (false) {
- Log.d(Constants.TAG, "invalid selection triggered " + ex);
- }
- throw ex;
- }
-
- }
-
- // expression <- ( expression ) | statement [AND_OR ( expression ) | statement] *
- // | statement [AND_OR expression]*
- private static void parseExpression(Lexer lexer) {
- for (;;) {
- // ( expression )
- if (lexer.currentToken() == Lexer.TOKEN_OPEN_PAREN) {
- lexer.advance();
- parseExpression(lexer);
- if (lexer.currentToken() != Lexer.TOKEN_CLOSE_PAREN) {
- throw new IllegalArgumentException("syntax error, unmatched parenthese");
- }
- lexer.advance();
- } else {
- // statement
- parseStatement(lexer);
- }
- if (lexer.currentToken() != Lexer.TOKEN_AND_OR) {
- break;
- }
- lexer.advance();
- }
- }
-
- // statement <- COLUMN COMPARE VALUE
- // | COLUMN IS NULL
- private static void parseStatement(Lexer lexer) {
- // both possibilities start with COLUMN
- if (lexer.currentToken() != Lexer.TOKEN_COLUMN) {
- throw new IllegalArgumentException("syntax error, expected column name");
- }
- lexer.advance();
-
- // statement <- COLUMN COMPARE VALUE
- if (lexer.currentToken() == Lexer.TOKEN_COMPARE) {
- lexer.advance();
- if (lexer.currentToken() != Lexer.TOKEN_VALUE) {
- throw new IllegalArgumentException("syntax error, expected quoted string");
- }
- lexer.advance();
- return;
- }
-
- // statement <- COLUMN IS NULL
- if (lexer.currentToken() == Lexer.TOKEN_IS) {
- lexer.advance();
- if (lexer.currentToken() != Lexer.TOKEN_NULL) {
- throw new IllegalArgumentException("syntax error, expected NULL");
- }
- lexer.advance();
- return;
- }
-
- // didn't get anything good after COLUMN
- throw new IllegalArgumentException("syntax error after column name");
- }
-
- /**
- * A simple lexer that recognizes the words of our restricted subset of SQL where clauses
- */
- private static class Lexer {
- public static final int TOKEN_START = 0;
- public static final int TOKEN_OPEN_PAREN = 1;
- public static final int TOKEN_CLOSE_PAREN = 2;
- public static final int TOKEN_AND_OR = 3;
- public static final int TOKEN_COLUMN = 4;
- public static final int TOKEN_COMPARE = 5;
- public static final int TOKEN_VALUE = 6;
- public static final int TOKEN_IS = 7;
- public static final int TOKEN_NULL = 8;
- public static final int TOKEN_END = 9;
-
- private final String mSelection;
- private final Set<String> mAllowedColumns;
- private int mOffset = 0;
- private int mCurrentToken = TOKEN_START;
- private final char[] mChars;
-
- public Lexer(String selection, Set<String> allowedColumns) {
- mSelection = selection;
- mAllowedColumns = allowedColumns;
- mChars = new char[mSelection.length()];
- mSelection.getChars(0, mChars.length, mChars, 0);
- advance();
- }
-
- public int currentToken() {
- return mCurrentToken;
- }
-
- public void advance() {
- char[] chars = mChars;
-
- // consume whitespace
- while (mOffset < chars.length && chars[mOffset] == ' ') {
- ++mOffset;
- }
-
- // end of input
- if (mOffset == chars.length) {
- mCurrentToken = TOKEN_END;
- return;
- }
-
- // "("
- if (chars[mOffset] == '(') {
- ++mOffset;
- mCurrentToken = TOKEN_OPEN_PAREN;
- return;
- }
-
- // ")"
- if (chars[mOffset] == ')') {
- ++mOffset;
- mCurrentToken = TOKEN_CLOSE_PAREN;
- return;
- }
-
- // "?"
- if (chars[mOffset] == '?') {
- ++mOffset;
- mCurrentToken = TOKEN_VALUE;
- return;
- }
-
- // "=" and "=="
- if (chars[mOffset] == '=') {
- ++mOffset;
- mCurrentToken = TOKEN_COMPARE;
- if (mOffset < chars.length && chars[mOffset] == '=') {
- ++mOffset;
- }
- return;
- }
-
- // ">" and ">="
- if (chars[mOffset] == '>') {
- ++mOffset;
- mCurrentToken = TOKEN_COMPARE;
- if (mOffset < chars.length && chars[mOffset] == '=') {
- ++mOffset;
- }
- return;
- }
-
- // "<", "<=" and "<>"
- if (chars[mOffset] == '<') {
- ++mOffset;
- mCurrentToken = TOKEN_COMPARE;
- if (mOffset < chars.length && (chars[mOffset] == '=' || chars[mOffset] == '>')) {
- ++mOffset;
- }
- return;
- }
-
- // "!="
- if (chars[mOffset] == '!') {
- ++mOffset;
- mCurrentToken = TOKEN_COMPARE;
- if (mOffset < chars.length && chars[mOffset] == '=') {
- ++mOffset;
- return;
- }
- throw new IllegalArgumentException("Unexpected character after !");
- }
-
- // columns and keywords
- // first look for anything that looks like an identifier or a keyword
- // and then recognize the individual words.
- // no attempt is made at discarding sequences of underscores with no alphanumeric
- // characters, even though it's not clear that they'd be legal column names.
- if (isIdentifierStart(chars[mOffset])) {
- int startOffset = mOffset;
- ++mOffset;
- while (mOffset < chars.length && isIdentifierChar(chars[mOffset])) {
- ++mOffset;
- }
- String word = mSelection.substring(startOffset, mOffset);
- if (mOffset - startOffset <= 4) {
- if (word.equals("IS")) {
- mCurrentToken = TOKEN_IS;
- return;
- }
- if (word.equals("OR") || word.equals("AND")) {
- mCurrentToken = TOKEN_AND_OR;
- return;
- }
- if (word.equals("NULL")) {
- mCurrentToken = TOKEN_NULL;
- return;
- }
- }
- if (mAllowedColumns.contains(word)) {
- mCurrentToken = TOKEN_COLUMN;
- return;
- }
- throw new IllegalArgumentException("unrecognized column or keyword: " + word);
- }
-
- // quoted strings
- if (chars[mOffset] == '\'') {
- ++mOffset;
- while (mOffset < chars.length) {
- if (chars[mOffset] == '\'') {
- if (mOffset + 1 < chars.length && chars[mOffset + 1] == '\'') {
- ++mOffset;
- } else {
- break;
- }
- }
- ++mOffset;
- }
- if (mOffset == chars.length) {
- throw new IllegalArgumentException("unterminated string");
- }
- ++mOffset;
- mCurrentToken = TOKEN_VALUE;
- return;
- }
-
- // anything we don't recognize
- throw new IllegalArgumentException("illegal character: " + chars[mOffset]);
- }
-
- private static final boolean isIdentifierStart(char c) {
- return c == '_' ||
- (c >= 'A' && c <= 'Z') ||
- (c >= 'a' && c <= 'z');
- }
-
- private static final boolean isIdentifierChar(char c) {
- return c == '_' ||
- (c >= 'A' && c <= 'Z') ||
- (c >= 'a' && c <= 'z') ||
- (c >= '0' && c <= '9');
- }
- }
}