diff --git a/guacamole-common/src/main/java/org/glyptodon/guacamole/protocol/FilteredGuacamoleWriter.java b/guacamole-common/src/main/java/org/glyptodon/guacamole/protocol/FilteredGuacamoleWriter.java new file mode 100644 index 000000000..26d8ac615 --- /dev/null +++ b/guacamole-common/src/main/java/org/glyptodon/guacamole/protocol/FilteredGuacamoleWriter.java @@ -0,0 +1,107 @@ +/* + * Copyright (C) 2014 Glyptodon LLC + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package org.glyptodon.guacamole.protocol; + +import org.glyptodon.guacamole.GuacamoleException; +import org.glyptodon.guacamole.GuacamoleServerException; +import org.glyptodon.guacamole.io.GuacamoleWriter; + +/** + * GuacamoleWriter which applies a given GuacamoleFilter to observe or alter + * all written instructions. Instructions may also be dropped or denied by + * the filter. + * + * @author Michael Jumper + */ +public class FilteredGuacamoleWriter implements GuacamoleWriter { + + /** + * The wrapped GuacamoleWriter. + */ + private final GuacamoleWriter writer; + + /** + * The filter to apply when writing instructions. + */ + private final GuacamoleFilter filter; + + /** + * Parser for reading instructions prior to writing, such that they can be + * passed on to the filter. + */ + private final GuacamoleParser parser = new GuacamoleParser(); + + /** + * Wraps the given GuacamoleWriter, applying the given filter to all written + * instructions. Future writes will only write instructions which pass + * the filter. + * + * @param writer The GuacamoleWriter to wrap. + * @param filter The filter which dictates which instructions are written, + * and how. + */ + public FilteredGuacamoleWriter(GuacamoleWriter writer, GuacamoleFilter filter) { + this.writer = writer; + this.filter = filter; + } + + @Override + public void write(char[] chunk, int offset, int length) throws GuacamoleException { + + // Write all data in chunk + while (length > 0) { + + // Pass as much data through the parser as possible + int parsed; + while ((parsed = parser.append(chunk, offset, length)) != 0) { + offset += parsed; + length -= parsed; + } + + // If no instruction is available, it must be incomplete + if (!parser.hasNext()) + throw new GuacamoleServerException("Filtered write() contained an incomplete instruction."); + + // Write single instruction through filter + writeInstruction(parser.next()); + + } + + } + + @Override + public void write(char[] chunk) throws GuacamoleException { + write(chunk, 0, chunk.length); + } + + @Override + public void writeInstruction(GuacamoleInstruction instruction) throws GuacamoleException { + + // Write instruction only if not dropped + GuacamoleInstruction filteredInstruction = filter.filter(instruction); + if (filteredInstruction != null) + writer.writeInstruction(filteredInstruction); + + } + +} diff --git a/guacamole-common/src/test/java/org/glyptodon/guacamole/protocol/FilteredGuacamoleWriterTest.java b/guacamole-common/src/test/java/org/glyptodon/guacamole/protocol/FilteredGuacamoleWriterTest.java new file mode 100644 index 000000000..c47a75624 --- /dev/null +++ b/guacamole-common/src/test/java/org/glyptodon/guacamole/protocol/FilteredGuacamoleWriterTest.java @@ -0,0 +1,73 @@ +/* + * Copyright (C) 2014 Glyptodon LLC + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +package org.glyptodon.guacamole.protocol; + +import java.io.StringWriter; +import org.glyptodon.guacamole.GuacamoleException; +import org.glyptodon.guacamole.io.GuacamoleWriter; +import org.glyptodon.guacamole.io.WriterGuacamoleWriter; +import static org.junit.Assert.*; +import org.junit.Test; + +/** + * Test which validates filtering of Guacamole instructions with + * FilteredGuacamoleWriter. + * + * @author Michael Jumper + */ +public class FilteredGuacamoleWriterTest { + + /** + * Filter which allows through "yes" instructions but drops all others. + */ + private class TestFilter implements GuacamoleFilter { + + @Override + public GuacamoleInstruction filter(GuacamoleInstruction instruction) throws GuacamoleException { + + if (instruction.getOpcode().equals("yes")) + return instruction; + + return null; + + } + + } + + @Test + public void testFilter() throws Exception { + + StringWriter stringWriter = new StringWriter(); + GuacamoleWriter writer = new FilteredGuacamoleWriter(new WriterGuacamoleWriter(stringWriter), + new TestFilter()); + + // Write a few chunks of complete instructions + writer.write("3.yes,1.A;2.no,1.B;3.yes,1.C;3.yes,1.D;4.nope,1.E;".toCharArray()); + writer.write("1.n,3.abc;3.yes,5.hello;2.no,4.test;3.yes,5.world;".toCharArray()); + + // Validate filtered results + assertEquals("3.yes,1.A;3.yes,1.C;3.yes,1.D;3.yes,5.hello;3.yes,5.world;", stringWriter.toString()); + + } + +}