Remove padding when writing CONTINUATION frame (#9752)

Motivation:

Padding was removed from CONTINUATION frame in http2-spec, as showed in [PR](https://github.com/http2/http2-spec/pull/510). We should follow it.

Modifications:

- Remove padding when writing CONTINUATION frame in DefaultHttp2FrameWriter
- Add a unit test for writing large header with padding

Result:

More spec-compliant
This commit is contained in:
zhangheng 2019-11-05 22:20:36 +08:00 committed by Norman Maurer
parent 804c33ef46
commit 044beae313
2 changed files with 66 additions and 22 deletions

View File

@ -386,7 +386,7 @@ public class DefaultHttp2FrameWriter implements Http2FrameWriter, Http2FrameSize
}
if (!flags.endOfHeaders()) {
writeContinuationFrames(ctx, streamId, headerBlock, padding, promiseAggregator);
writeContinuationFrames(ctx, streamId, headerBlock, promiseAggregator);
}
} catch (Http2Exception e) {
promiseAggregator.setFailure(e);
@ -533,7 +533,7 @@ public class DefaultHttp2FrameWriter implements Http2FrameWriter, Http2FrameSize
}
if (!flags.endOfHeaders()) {
writeContinuationFrames(ctx, streamId, headerBlock, padding, promiseAggregator);
writeContinuationFrames(ctx, streamId, headerBlock, promiseAggregator);
}
} catch (Http2Exception e) {
promiseAggregator.setFailure(e);
@ -553,28 +553,19 @@ public class DefaultHttp2FrameWriter implements Http2FrameWriter, Http2FrameSize
* Writes as many continuation frames as needed until {@code padding} and {@code headerBlock} are consumed.
*/
private ChannelFuture writeContinuationFrames(ChannelHandlerContext ctx, int streamId,
ByteBuf headerBlock, int padding, SimpleChannelPromiseAggregator promiseAggregator) {
Http2Flags flags = new Http2Flags().paddingPresent(padding > 0);
int maxFragmentLength = maxFrameSize - padding;
// TODO: same padding is applied to all frames, is this desired?
if (maxFragmentLength <= 0) {
return promiseAggregator.setFailure(new IllegalArgumentException(
"Padding [" + padding + "] is too large for max frame size [" + maxFrameSize + "]"));
}
ByteBuf headerBlock, SimpleChannelPromiseAggregator promiseAggregator) {
Http2Flags flags = new Http2Flags();
if (headerBlock.isReadable()) {
// The frame header (and padding) only changes on the last frame, so allocate it once and re-use
int fragmentReadableBytes = min(headerBlock.readableBytes(), maxFragmentLength);
int payloadLength = fragmentReadableBytes + padding;
int fragmentReadableBytes = min(headerBlock.readableBytes(), maxFrameSize);
ByteBuf buf = ctx.alloc().buffer(CONTINUATION_FRAME_HEADER_LENGTH);
writeFrameHeaderInternal(buf, payloadLength, CONTINUATION, flags, streamId);
writePaddingLength(buf, padding);
writeFrameHeaderInternal(buf, fragmentReadableBytes, CONTINUATION, flags, streamId);
do {
fragmentReadableBytes = min(headerBlock.readableBytes(), maxFragmentLength);
fragmentReadableBytes = min(headerBlock.readableBytes(), maxFrameSize);
ByteBuf fragment = headerBlock.readRetainedSlice(fragmentReadableBytes);
payloadLength = fragmentReadableBytes + padding;
if (headerBlock.isReadable()) {
ctx.write(buf.retain(), promiseAggregator.newPromise());
} else {
@ -582,17 +573,12 @@ public class DefaultHttp2FrameWriter implements Http2FrameWriter, Http2FrameSize
flags = flags.endOfHeaders(true);
buf.release();
buf = ctx.alloc().buffer(CONTINUATION_FRAME_HEADER_LENGTH);
writeFrameHeaderInternal(buf, payloadLength, CONTINUATION, flags, streamId);
writePaddingLength(buf, padding);
writeFrameHeaderInternal(buf, fragmentReadableBytes, CONTINUATION, flags, streamId);
ctx.write(buf, promiseAggregator.newPromise());
}
ctx.write(fragment, promiseAggregator.newPromise());
// Write out the padding, if any.
if (paddingBytes(padding) > 0) {
ctx.write(ZERO_BUFFER.slice(0, paddingBytes(padding)), promiseAggregator.newPromise());
}
} while (headerBlock.isReadable());
}
return promiseAggregator;

View File

@ -205,6 +205,48 @@ public class DefaultHttp2FrameWriterTest {
secondPayload);
}
@Test
public void writeLargeHeaderWithPadding() throws Exception {
int streamId = 1;
Http2Headers headers = new DefaultHttp2Headers()
.method("GET").path("/").authority("foo.com").scheme("https");
headers = dummyHeaders(headers, 20);
http2HeadersEncoder.configuration().maxHeaderListSize(Integer.MAX_VALUE);
frameWriter.headersConfiguration().maxHeaderListSize(Integer.MAX_VALUE);
frameWriter.maxFrameSize(Http2CodecUtil.MAX_FRAME_SIZE_LOWER_BOUND);
frameWriter.writeHeaders(ctx, streamId, headers, 5, true, promise);
byte[] expectedPayload = buildLargeHeaderPayload(streamId, headers, (byte) 4,
Http2CodecUtil.MAX_FRAME_SIZE_LOWER_BOUND);
// First frame: HEADER(length=0x4000, flags=0x09)
assertEquals(Http2CodecUtil.MAX_FRAME_SIZE_LOWER_BOUND,
outbound.readUnsignedMedium());
assertEquals(0x01, outbound.readByte());
assertEquals(0x09, outbound.readByte()); // 0x01 + 0x08
assertEquals(streamId, outbound.readInt());
byte[] firstPayload = new byte[Http2CodecUtil.MAX_FRAME_SIZE_LOWER_BOUND];
outbound.readBytes(firstPayload);
int remainPayloadLength = expectedPayload.length - Http2CodecUtil.MAX_FRAME_SIZE_LOWER_BOUND;
// Second frame: CONTINUATION(length=remainPayloadLength, flags=0x04)
assertEquals(remainPayloadLength, outbound.readUnsignedMedium());
assertEquals(0x09, outbound.readByte());
assertEquals(0x04, outbound.readByte());
assertEquals(streamId, outbound.readInt());
byte[] secondPayload = new byte[remainPayloadLength];
outbound.readBytes(secondPayload);
assertArrayEquals(Arrays.copyOfRange(expectedPayload, 0, firstPayload.length),
firstPayload);
assertArrayEquals(Arrays.copyOfRange(expectedPayload, firstPayload.length,
expectedPayload.length),
secondPayload);
}
@Test
public void writeFrameZeroPayload() throws Exception {
frameWriter.writeFrame(ctx, (byte) 0xf, 0, new Http2Flags(), Unpooled.EMPTY_BUFFER, promise);
@ -266,6 +308,22 @@ public class DefaultHttp2FrameWriterTest {
}
}
private byte[] buildLargeHeaderPayload(int streamId, Http2Headers headers, byte padding, int maxFrameSize)
throws Http2Exception, IOException {
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
try {
outputStream.write(padding);
byte[] payload = headerPayload(streamId, headers);
int firstPayloadSize = maxFrameSize - (padding + 1); //1 for padding length
outputStream.write(payload, 0, firstPayloadSize);
outputStream.write(new byte[padding]);
outputStream.write(payload, firstPayloadSize, payload.length - firstPayloadSize);
return outputStream.toByteArray();
} finally {
outputStream.close();
}
}
private static Http2Headers dummyHeaders(Http2Headers headers, int times) {
final String largeValue = repeat("dummy-value", 100);
for (int i = 0; i < times; i++) {