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[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2#79997

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Merged
carlossanlop merged 1 commit into from
Jan 5, 2023
Merged

[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2 #79997

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3 changes: 3 additions & 0 deletions src/libraries/System.Net.Http/src/Resources/Strings.resx
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Original file line numberDiff line numberDiff line change
Expand Up@@ -360,6 +360,9 @@
<data name="net_http_buffer_insufficient_length" xml:space="preserve">
<value>The buffer was not long enough.</value>
</data>
<data name="net_http_request_headers_exceeded_length" xml:space="preserve">
<value>The HTTP request headers length exceeded the server limit of {0} bytes.</value>
</data>
<data name="net_http_response_headers_exceeded_length" xml:space="preserve">
<value>The HTTP response headers length exceeded the set limit of {0} bytes.</value>
</data>
Expand Down
60 changes: 51 additions & 9 deletions src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -50,6 +50,10 @@ internal sealed partial class Http2Connection : HttpConnectionBase
private readonly Channel<WriteQueueEntry> _writeChannel;
private bool _lastPendingWriterShouldFlush;

// Server-advertised SETTINGS_MAX_HEADER_LIST_SIZE
// https://www.rfc-editor.org/rfc/rfc9113.html#section-6.5.2-2.12.1
private uint _maxHeaderListSize = uint.MaxValue; // Defaults to infinite

// This flag indicates that the connection is shutting down and cannot accept new requests, because of one of the following conditions:
// (1) We received a GOAWAY frame from the server
// (2) We have exhaustead StreamIds (i.e. _nextStream == MaxStreamId)
Expand DownExpand Up@@ -156,6 +160,14 @@ public Http2Connection(HttpConnectionPool pool, Stream stream)
_nextPingRequestTimestamp = Environment.TickCount64 + _keepAlivePingDelay;
_keepAlivePingPolicy = _pool.Settings._keepAlivePingPolicy;

uint maxHeaderListSize = _pool._lastSeenHttp2MaxHeaderListSize;
if (maxHeaderListSize > 0)
{
// Previous connections to the same host advertised a limit.
// Use this as an initial value before we receive the SETTINGS frame.
_maxHeaderListSize = maxHeaderListSize;
}

if (HttpTelemetry.Log.IsEnabled())
{
HttpTelemetry.Log.Http20ConnectionEstablished();
Expand DownExpand Up@@ -800,6 +812,8 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
uint settingValue = BinaryPrimitives.ReadUInt32BigEndian(settings);
settings = settings.Slice(4);

if (NetEventSource.Log.IsEnabled()) Trace($"Applying setting {(SettingId)settingId}={settingValue}");

switch ((SettingId)settingId)
{
case SettingId.MaxConcurrentStreams:
Expand All@@ -825,6 +839,11 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
// We don't actually store this value; we always send frames of the minimum size (16K).
break;

case SettingId.MaxHeaderListSize:
_maxHeaderListSize = settingValue;
_pool._lastSeenHttp2MaxHeaderListSize = _maxHeaderListSize;
break;

default:
// All others are ignored because we don't care about them.
// Note, per RFC, unknown settings IDs should be ignored.
Expand DownExpand Up@@ -1332,17 +1351,19 @@ private void WriteBytes(ReadOnlySpan<byte> bytes, ref ArrayBuffer headerBuffer)
headerBuffer.Commit(bytes.Length);
}

private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
private int WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
{
if (NetEventSource.Log.IsEnabled()) Trace("");

if (headers.HeaderStore is null)
{
return;
return 0;
}

HeaderEncodingSelector<HttpRequestMessage>? encodingSelector = _pool.Settings._requestHeaderEncodingSelector;

int headerListSize = headers.HeaderStore.Count * HeaderField.RfcOverhead;

ref string[]? tmpHeaderValuesArray = ref t_headerValues;
foreach (KeyValuePair<HeaderDescriptor, object> header in headers.HeaderStore)
{
Expand All@@ -1360,6 +1381,10 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
// The Connection, Upgrade and ProxyConnection headers are also not supported in HTTP2.
if (knownHeader != KnownHeaders.Host && knownHeader != KnownHeaders.Connection && knownHeader != KnownHeaders.Upgrade && knownHeader != KnownHeaders.ProxyConnection)
{
// The length of the encoded name may be shorter than the actual name.
// Ensure that headerListSize is always >= of the actual size.
headerListSize += knownHeader.Name.Length;

if (header.Key.KnownHeader == KnownHeaders.TE)
{
// HTTP/2 allows only 'trailers' TE header. rfc7540 8.1.2.2
Expand DownExpand Up@@ -1400,6 +1425,8 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
WriteLiteralHeader(header.Key.Name, headerValues, valueEncoding, ref headerBuffer);
}
}

return headerListSize;
}

private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuffer)
Expand DownExpand Up@@ -1430,9 +1457,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff

WriteIndexedHeader(_stream is SslStream ? H2StaticTable.SchemeHttps : H2StaticTable.SchemeHttp, ref headerBuffer);

if (request.HasHeaders && request.Headers.Host != null)
if (request.HasHeaders && request.Headers.Host is string host)
{
WriteIndexedHeader(H2StaticTable.Authority, request.Headers.Host, ref headerBuffer);
WriteIndexedHeader(H2StaticTable.Authority, host, ref headerBuffer);
}
else
{
Expand All@@ -1450,9 +1477,11 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
WriteIndexedHeader(H2StaticTable.PathSlash, pathAndQuery, ref headerBuffer);
}

int headerListSize = 3 * HeaderField.RfcOverhead; // Method, Authority, Path

if (request.HasHeaders)
{
WriteHeaderCollection(request, request.Headers, ref headerBuffer);
headerListSize += WriteHeaderCollection(request, request.Headers, ref headerBuffer);
}

// Determine cookies to send.
Expand All@@ -1462,9 +1491,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
if (cookiesFromContainer != string.Empty)
{
WriteBytes(KnownHeaders.Cookie.Http2EncodedName, ref headerBuffer);

Encoding? cookieEncoding = _pool.Settings._requestHeaderEncodingSelector?.Invoke(KnownHeaders.Cookie.Name, request);
WriteLiteralHeaderValue(cookiesFromContainer, cookieEncoding, ref headerBuffer);
headerListSize += HttpKnownHeaderNames.Cookie.Length + HeaderField.RfcOverhead;
}
}

Expand All@@ -1476,11 +1505,24 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
{
WriteBytes(KnownHeaders.ContentLength.Http2EncodedName, ref headerBuffer);
WriteLiteralHeaderValue("0", valueEncoding: null, ref headerBuffer);
headerListSize += HttpKnownHeaderNames.ContentLength.Length + HeaderField.RfcOverhead;
}
}
else
{
WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
headerListSize += WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
}

// The headerListSize is an approximation of the total header length.
// This is acceptable as long as the value is always >= the actual length.
// We must avoid ever sending more than the server allowed.
// This approach must be revisted if we ever support the dynamic table or compression when sending requests.
headerListSize += headerBuffer.ActiveLength;

uint maxHeaderListSize = _maxHeaderListSize;
if ((uint)headerListSize > maxHeaderListSize)
{
throw new HttpRequestException(SR.Format(SR.net_http_request_headers_exceeded_length, maxHeaderListSize));
}
}

Expand DownExpand Up@@ -1553,10 +1595,10 @@ private async ValueTask<Http2Stream> SendHeadersAsync(HttpRequestMessage request
// streams are created and started in order.
await PerformWriteAsync(totalSize, (thisRef: this, http2Stream, headerBytes, endStream: (request.Content == null), mustFlush), static (s, writeBuffer) =>
{
if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

s.thisRef.AddStream(s.http2Stream);

if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

Span<byte> span = writeBuffer.Span;

// Copy the HEADERS frame.
Expand Down
8 changes: 8 additions & 0 deletions src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnectionPool.cs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -96,6 +96,14 @@ internal sealed class HttpConnectionPool : IDisposable
private SemaphoreSlim? _http3ConnectionCreateLock;
internal readonly byte[]? _http3EncodedAuthorityHostHeader;

// These settings are advertised by the server via SETTINGS_MAX_HEADER_LIST_SIZE.
// If we had previous connections to the same host in this pool, memorize the last value seen.
// This value is used as an initial value for new connections before they have a chance to observe the SETTINGS frame.
// Doing so avoids immediately exceeding the server limit on the first request, potentially causing the connection to be torn down.
// 0 means there were no previous connections, or they hadn't advertised this limit.
// There is no need to lock when updating these values - we're only interested in saving _a_ value, not necessarily the min/max/last.
internal uint _lastSeenHttp2MaxHeaderListSize;

/// <summary>For non-proxy connection pools, this is the host name in bytes; for proxies, null.</summary>
private readonly byte[]? _hostHeaderValueBytes;
/// <summary>Options specialized and cached for this pool and its key.</summary>
Expand Down
101 changes: 101 additions & 0 deletions src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -1205,6 +1205,107 @@ public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLengt
public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Test(ITestOutputHelper output) : base(output) { }
}

[ConditionalClass(typeof(SocketsHttpHandler), nameof(SocketsHttpHandler.IsSupported))]
public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2 : HttpClientHandlerTestBase
{
public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2(ITestOutputHelper output) : base(output) { }
protected override Version UseVersion => HttpVersion.Version20;

[Fact]
public async Task ServerAdvertisedMaxHeaderListSize_IsHonoredByClient()
{
const int Limit = 10_000;

using HttpClientHandler handler = CreateHttpClientHandler();
using HttpClient client = CreateHttpClient(handler);

// We want to test that the client remembered the setting it received from the previous connection.
// To do this, we trick the client into using the same HttpConnectionPool for both server connections.
Uri lastServerUri = null;

GetUnderlyingSocketsHttpHandler(handler).ConnectCallback = async (context, ct) =>
{
Assert.Equal("foo", context.DnsEndPoint.Host);

Socket socket = new Socket(SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
try
{
await socket.ConnectAsync(lastServerUri.IdnHost, lastServerUri.Port);
return new NetworkStream(socket, ownsSocket: true);
}
catch
{
socket.Dispose();
throw;
}
};

TaskCompletionSource waitingForLastRequest = new(TaskCreationOptions.RunContinuationsAsynchronously);

await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
{
lastServerUri = uri;
uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

// Send a dummy request to ensure the SETTINGS frame has been received.
Assert.Equal("Hello world", await client.GetStringAsync(uri));

HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
request.Headers.Add("Foo", new string('a', Limit));

Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
Assert.Contains(Limit.ToString(), ex.Message);

request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
for (int i = 0; i < Limit / 40; i++)
{
request.Headers.Add($"Foo-{i}", "");
}

ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
Assert.Contains(Limit.ToString(), ex.Message);

await waitingForLastRequest.Task.WaitAsync(TimeSpan.FromSeconds(10));

// Ensure that the connection is still usable for requests that don't hit the limit.
Assert.Equal("Hello world", await client.GetStringAsync(uri));
},
async server =>
{
var setting = new SettingsEntry { SettingId = SettingId.MaxHeaderListSize, Value = Limit };

using GenericLoopbackConnection connection = await ((Http2LoopbackServer)server).EstablishConnectionAsync(setting);

await connection.ReadRequestDataAsync();
await connection.SendResponseAsync(content: "Hello world");

waitingForLastRequest.SetResult();

// HandleRequestAsync will close the connection
await connection.HandleRequestAsync(content: "Hello world");
});

await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
{
lastServerUri = uri;
uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
request.Headers.Add("Foo", new string('a', Limit));

Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
Assert.Contains(Limit.ToString(), ex.Message);

// Ensure that the connection is still usable for requests that don't hit the limit.
Assert.Equal("Hello world", await client.GetStringAsync(uri));
},
async server =>
{
await server.HandleRequestAsync(content: "Hello world");
});
}
}

[SkipOnPlatform(TestPlatforms.Browser, "Socket is not supported on Browser")]
public sealed class SocketsHttpHandler_HttpClientHandler_Authentication_Test : HttpClientHandler_Authentication_Test
{
Expand Down
, 'i'); if (__m === '*' || __re.test(location.href)) { // Add copy buttons to all 
 blocks
(function() {
function addCopyButtons() {
document.querySelectorAll('pre code').forEach(function(codeBlock) {
if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;
codeBlock.parentElement.setAttribute('data-copy-added', 'true');
var btn = document.createElement('button');
btn.textContent = 'Copy';
btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';
btn.onmouseover = function() { this.style.opacity = '1'; };
btn.onmouseout = function() { this.style.opacity = '0.7'; };
btn.onclick = function() {
navigator.clipboard.writeText(codeBlock.textContent).then(function() {
btn.textContent = 'Copied!';
setTimeout(function() { btn.textContent = 'Copy'; }, 1500);
});
};
codeBlock.parentElement.style.position = 'relative';
codeBlock.parentElement.appendChild(btn);
});
}
addCopyButtons();
// Re-run on dynamic content
var observer = new MutationObserver(addCopyButtons);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2 by MihaZupan · Pull Request #79997 · dotnet/runtime · GitHub
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[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2#79997

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to your account

 Merged

carlossanlop
merged 1 commit into

from

Jan 5, 2023
 Merged


[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2
#79997
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3 changes: 3 additions & 0 deletions
src/libraries/System.Net.Http/src/Resources/Strings.resx

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Original file line numberDiff line numberDiff line change
Expand Up@@ -360,6 +360,9 @@
 <data name="net_http_buffer_insufficient_length" xml:space="preserve">
 <value>The buffer was not long enough.</value>
 </data>
 <data name="net_http_request_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP request headers length exceeded the server limit of {0} bytes.</value>
 </data>
 <data name="net_http_response_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP response headers length exceeded the set limit of {0} bytes.</value>
 </data>
Expand Down

60 changes: 51 additions & 9 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -50,6 +50,10 @@ internal sealed partial class Http2Connection : HttpConnectionBase
 private readonly Channel<WriteQueueEntry> _writeChannel;
 private bool _lastPendingWriterShouldFlush;

 // Server-advertised SETTINGS_MAX_HEADER_LIST_SIZE
 // https://www.rfc-editor.org/rfc/rfc9113.html#section-6.5.2-2.12.1
 private uint _maxHeaderListSize = uint.MaxValue; // Defaults to infinite

 // This flag indicates that the connection is shutting down and cannot accept new requests, because of one of the following conditions:
 // (1) We received a GOAWAY frame from the server
 // (2) We have exhaustead StreamIds (i.e. _nextStream == MaxStreamId)
Expand DownExpand Up@@ -156,6 +160,14 @@ public Http2Connection(HttpConnectionPool pool, Stream stream)
 _nextPingRequestTimestamp = Environment.TickCount64 + _keepAlivePingDelay;
 _keepAlivePingPolicy = _pool.Settings._keepAlivePingPolicy;

 uint maxHeaderListSize = _pool._lastSeenHttp2MaxHeaderListSize;
 if (maxHeaderListSize > 0)
 {
 // Previous connections to the same host advertised a limit.
 // Use this as an initial value before we receive the SETTINGS frame.
 _maxHeaderListSize = maxHeaderListSize;
 }

 if (HttpTelemetry.Log.IsEnabled())
 {
 HttpTelemetry.Log.Http20ConnectionEstablished();
Expand DownExpand Up@@ -800,6 +812,8 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 uint settingValue = BinaryPrimitives.ReadUInt32BigEndian(settings);
 settings = settings.Slice(4);

 if (NetEventSource.Log.IsEnabled()) Trace($"Applying setting {(SettingId)settingId}={settingValue}");

 switch ((SettingId)settingId)
 {
 case SettingId.MaxConcurrentStreams:
Expand All@@ -825,6 +839,11 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 // We don't actually store this value; we always send frames of the minimum size (16K).
 break;

 case SettingId.MaxHeaderListSize:
 _maxHeaderListSize = settingValue;
 _pool._lastSeenHttp2MaxHeaderListSize = _maxHeaderListSize;
 break;

 default:
 // All others are ignored because we don't care about them.
 // Note, per RFC, unknown settings IDs should be ignored.
Expand DownExpand Up@@ -1332,17 +1351,19 @@ private void WriteBytes(ReadOnlySpan<byte> bytes, ref ArrayBuffer headerBuffer)
 headerBuffer.Commit(bytes.Length);
 }

 private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 private int WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 {
 if (NetEventSource.Log.IsEnabled()) Trace("");

 if (headers.HeaderStore is null)
 {
 return;
 return 0;
 }

 HeaderEncodingSelector<HttpRequestMessage>? encodingSelector = _pool.Settings._requestHeaderEncodingSelector;

 int headerListSize = headers.HeaderStore.Count * HeaderField.RfcOverhead;

 ref string[]? tmpHeaderValuesArray = ref t_headerValues;
 foreach (KeyValuePair<HeaderDescriptor, object> header in headers.HeaderStore)
 {
Expand All@@ -1360,6 +1381,10 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 // The Connection, Upgrade and ProxyConnection headers are also not supported in HTTP2.
 if (knownHeader != KnownHeaders.Host && knownHeader != KnownHeaders.Connection && knownHeader != KnownHeaders.Upgrade && knownHeader != KnownHeaders.ProxyConnection)
 {
 // The length of the encoded name may be shorter than the actual name.
 // Ensure that headerListSize is always >= of the actual size.
 headerListSize += knownHeader.Name.Length;

 if (header.Key.KnownHeader == KnownHeaders.TE)
 {
 // HTTP/2 allows only 'trailers' TE header. rfc7540 8.1.2.2
Expand DownExpand Up@@ -1400,6 +1425,8 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 WriteLiteralHeader(header.Key.Name, headerValues, valueEncoding, ref headerBuffer);
 }
 }

 return headerListSize;
 }

 private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuffer)
Expand DownExpand Up@@ -1430,9 +1457,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff

 WriteIndexedHeader(_stream is SslStream ? H2StaticTable.SchemeHttps : H2StaticTable.SchemeHttp, ref headerBuffer);

 if (request.HasHeaders && request.Headers.Host != null)
 if (request.HasHeaders && request.Headers.Host is string host)
 {
 WriteIndexedHeader(H2StaticTable.Authority, request.Headers.Host, ref headerBuffer);
 WriteIndexedHeader(H2StaticTable.Authority, host, ref headerBuffer);
 }
 else
 {
Expand All@@ -1450,9 +1477,11 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 WriteIndexedHeader(H2StaticTable.PathSlash, pathAndQuery, ref headerBuffer);
 }

 int headerListSize = 3 * HeaderField.RfcOverhead; // Method, Authority, Path

 if (request.HasHeaders)
 {
 WriteHeaderCollection(request, request.Headers, ref headerBuffer);
headerListSize += WriteHeaderCollection(request, request.Headers, ref headerBuffer);
 }

 // Determine cookies to send.
Expand All@@ -1462,9 +1491,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 if (cookiesFromContainer != string.Empty)
 {
 WriteBytes(KnownHeaders.Cookie.Http2EncodedName, ref headerBuffer);

 Encoding? cookieEncoding = _pool.Settings._requestHeaderEncodingSelector?.Invoke(KnownHeaders.Cookie.Name, request);
 WriteLiteralHeaderValue(cookiesFromContainer, cookieEncoding, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.Cookie.Length + HeaderField.RfcOverhead;
 }
 }

Expand All@@ -1476,11 +1505,24 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 {
 WriteBytes(KnownHeaders.ContentLength.Http2EncodedName, ref headerBuffer);
 WriteLiteralHeaderValue("0", valueEncoding: null, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.ContentLength.Length + HeaderField.RfcOverhead;
 }
 }
 else
 {
 WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 headerListSize += WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 }

 // The headerListSize is an approximation of the total header length.
 // This is acceptable as long as the value is always >= the actual length.
 // We must avoid ever sending more than the server allowed.
 // This approach must be revisted if we ever support the dynamic table or compression when sending requests.
 headerListSize += headerBuffer.ActiveLength;

 uint maxHeaderListSize = _maxHeaderListSize;
 if ((uint)headerListSize > maxHeaderListSize)
 {
 throw new HttpRequestException(SR.Format(SR.net_http_request_headers_exceeded_length, maxHeaderListSize));
 }
 }

Expand DownExpand Up@@ -1553,10 +1595,10 @@ private async ValueTask<Http2Stream> SendHeadersAsync(HttpRequestMessage request
 // streams are created and started in order.
 await PerformWriteAsync(totalSize, (thisRef: this, http2Stream, headerBytes, endStream: (request.Content == null), mustFlush), static (s, writeBuffer) =>
 {
 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 s.thisRef.AddStream(s.http2Stream);

 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 Span<byte> span = writeBuffer.Span;

 // Copy the HEADERS frame.
Expand Down

8 changes: 8 additions & 0 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnectionPool.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -96,6 +96,14 @@ internal sealed class HttpConnectionPool : IDisposable
 private SemaphoreSlim? _http3ConnectionCreateLock;
 internal readonly byte[]? _http3EncodedAuthorityHostHeader;

 // These settings are advertised by the server via SETTINGS_MAX_HEADER_LIST_SIZE.
 // If we had previous connections to the same host in this pool, memorize the last value seen.
 // This value is used as an initial value for new connections before they have a chance to observe the SETTINGS frame.
 // Doing so avoids immediately exceeding the server limit on the first request, potentially causing the connection to be torn down.
 // 0 means there were no previous connections, or they hadn't advertised this limit.
 // There is no need to lock when updating these values - we're only interested in saving _a_ value, not necessarily the min/max/last.
 internal uint _lastSeenHttp2MaxHeaderListSize;

 /// <summary>For non-proxy connection pools, this is the host name in bytes; for proxies, null.</summary>
 private readonly byte[]? _hostHeaderValueBytes;
 /// <summary>Options specialized and cached for this pool and its key.</summary>
Expand Down

101 changes: 101 additions & 0 deletions
src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1205,6 +1205,107 @@ public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLengt
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Test(ITestOutputHelper output) : base(output) { }
 }

 [ConditionalClass(typeof(SocketsHttpHandler), nameof(SocketsHttpHandler.IsSupported))]
 public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2 : HttpClientHandlerTestBase
 {
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2(ITestOutputHelper output) : base(output) { }
 protected override Version UseVersion => HttpVersion.Version20;

 [Fact]
 public async Task ServerAdvertisedMaxHeaderListSize_IsHonoredByClient()
 {
 const int Limit = 10_000;

 using HttpClientHandler handler = CreateHttpClientHandler();
 using HttpClient client = CreateHttpClient(handler);

 // We want to test that the client remembered the setting it received from the previous connection.
 // To do this, we trick the client into using the same HttpConnectionPool for both server connections.
 Uri lastServerUri = null;

 GetUnderlyingSocketsHttpHandler(handler).ConnectCallback = async (context, ct) =>
 {
 Assert.Equal("foo", context.DnsEndPoint.Host);

 Socket socket = new Socket(SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
 try
 {
 await socket.ConnectAsync(lastServerUri.IdnHost, lastServerUri.Port);
 return new NetworkStream(socket, ownsSocket: true);
 }
 catch
 {
 socket.Dispose();
 throw;
 }
 };

 TaskCompletionSource waitingForLastRequest = new(TaskCreationOptions.RunContinuationsAsynchronously);

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 // Send a dummy request to ensure the SETTINGS frame has been received.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 for (int i = 0; i < Limit / 40; i++)
 {
 request.Headers.Add($"Foo-{i}", "");
 }

 ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 await waitingForLastRequest.Task.WaitAsync(TimeSpan.FromSeconds(10));

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 var setting = new SettingsEntry { SettingId = SettingId.MaxHeaderListSize, Value = Limit };

 using GenericLoopbackConnection connection = await ((Http2LoopbackServer)server).EstablishConnectionAsync(setting);

 await connection.ReadRequestDataAsync();
 await connection.SendResponseAsync(content: "Hello world");

 waitingForLastRequest.SetResult();

 // HandleRequestAsync will close the connection
 await connection.HandleRequestAsync(content: "Hello world");
 });

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 await server.HandleRequestAsync(content: "Hello world");
 });
 }
 }

 [SkipOnPlatform(TestPlatforms.Browser, "Socket is not supported on Browser")]
 public sealed class SocketsHttpHandler_HttpClientHandler_Authentication_Test : HttpClientHandler_Authentication_Test
 {
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Force GitHub README to respect dark mode
(function() {
var style = document.createElement('style');
style.textContent = '
.markdown-body {
color-scheme: dark light;
}
.markdown-body pre { background: #161b22 !important; }
.markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }
.markdown-body table th, .markdown-body table td { border-color: #30363d !important; }
.markdown-body img { background: #0d1117; }
.markdown-body blockquote { border-left-color: #8b949e; }
.markdown-body hr { border-color: #30363d; }
';
document.head.appendChild(style);
})();
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2 by MihaZupan · Pull Request #79997 · dotnet/runtime · GitHub
Skip to content
[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2#79997

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 Merged

carlossanlop
merged 1 commit into

from

Jan 5, 2023
 Merged


[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2
#79997
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3 changes: 3 additions & 0 deletions
src/libraries/System.Net.Http/src/Resources/Strings.resx

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Original file line numberDiff line numberDiff line change
Expand Up@@ -360,6 +360,9 @@
 <data name="net_http_buffer_insufficient_length" xml:space="preserve">
 <value>The buffer was not long enough.</value>
 </data>
 <data name="net_http_request_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP request headers length exceeded the server limit of {0} bytes.</value>
 </data>
 <data name="net_http_response_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP response headers length exceeded the set limit of {0} bytes.</value>
 </data>
Expand Down

60 changes: 51 additions & 9 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -50,6 +50,10 @@ internal sealed partial class Http2Connection : HttpConnectionBase
 private readonly Channel<WriteQueueEntry> _writeChannel;
 private bool _lastPendingWriterShouldFlush;

 // Server-advertised SETTINGS_MAX_HEADER_LIST_SIZE
 // https://www.rfc-editor.org/rfc/rfc9113.html#section-6.5.2-2.12.1
 private uint _maxHeaderListSize = uint.MaxValue; // Defaults to infinite

 // This flag indicates that the connection is shutting down and cannot accept new requests, because of one of the following conditions:
 // (1) We received a GOAWAY frame from the server
 // (2) We have exhaustead StreamIds (i.e. _nextStream == MaxStreamId)
Expand DownExpand Up@@ -156,6 +160,14 @@ public Http2Connection(HttpConnectionPool pool, Stream stream)
 _nextPingRequestTimestamp = Environment.TickCount64 + _keepAlivePingDelay;
 _keepAlivePingPolicy = _pool.Settings._keepAlivePingPolicy;

 uint maxHeaderListSize = _pool._lastSeenHttp2MaxHeaderListSize;
 if (maxHeaderListSize > 0)
 {
 // Previous connections to the same host advertised a limit.
 // Use this as an initial value before we receive the SETTINGS frame.
 _maxHeaderListSize = maxHeaderListSize;
 }

 if (HttpTelemetry.Log.IsEnabled())
 {
 HttpTelemetry.Log.Http20ConnectionEstablished();
Expand DownExpand Up@@ -800,6 +812,8 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 uint settingValue = BinaryPrimitives.ReadUInt32BigEndian(settings);
 settings = settings.Slice(4);

 if (NetEventSource.Log.IsEnabled()) Trace($"Applying setting {(SettingId)settingId}={settingValue}");

 switch ((SettingId)settingId)
 {
 case SettingId.MaxConcurrentStreams:
Expand All@@ -825,6 +839,11 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 // We don't actually store this value; we always send frames of the minimum size (16K).
 break;

 case SettingId.MaxHeaderListSize:
 _maxHeaderListSize = settingValue;
 _pool._lastSeenHttp2MaxHeaderListSize = _maxHeaderListSize;
 break;

 default:
 // All others are ignored because we don't care about them.
 // Note, per RFC, unknown settings IDs should be ignored.
Expand DownExpand Up@@ -1332,17 +1351,19 @@ private void WriteBytes(ReadOnlySpan<byte> bytes, ref ArrayBuffer headerBuffer)
 headerBuffer.Commit(bytes.Length);
 }

 private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 private int WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 {
 if (NetEventSource.Log.IsEnabled()) Trace("");

 if (headers.HeaderStore is null)
 {
 return;
 return 0;
 }

 HeaderEncodingSelector<HttpRequestMessage>? encodingSelector = _pool.Settings._requestHeaderEncodingSelector;

 int headerListSize = headers.HeaderStore.Count * HeaderField.RfcOverhead;

 ref string[]? tmpHeaderValuesArray = ref t_headerValues;
 foreach (KeyValuePair<HeaderDescriptor, object> header in headers.HeaderStore)
 {
Expand All@@ -1360,6 +1381,10 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 // The Connection, Upgrade and ProxyConnection headers are also not supported in HTTP2.
 if (knownHeader != KnownHeaders.Host && knownHeader != KnownHeaders.Connection && knownHeader != KnownHeaders.Upgrade && knownHeader != KnownHeaders.ProxyConnection)
 {
 // The length of the encoded name may be shorter than the actual name.
 // Ensure that headerListSize is always >= of the actual size.
 headerListSize += knownHeader.Name.Length;

 if (header.Key.KnownHeader == KnownHeaders.TE)
 {
 // HTTP/2 allows only 'trailers' TE header. rfc7540 8.1.2.2
Expand DownExpand Up@@ -1400,6 +1425,8 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 WriteLiteralHeader(header.Key.Name, headerValues, valueEncoding, ref headerBuffer);
 }
 }

 return headerListSize;
 }

 private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuffer)
Expand DownExpand Up@@ -1430,9 +1457,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff

 WriteIndexedHeader(_stream is SslStream ? H2StaticTable.SchemeHttps : H2StaticTable.SchemeHttp, ref headerBuffer);

 if (request.HasHeaders && request.Headers.Host != null)
 if (request.HasHeaders && request.Headers.Host is string host)
 {
 WriteIndexedHeader(H2StaticTable.Authority, request.Headers.Host, ref headerBuffer);
 WriteIndexedHeader(H2StaticTable.Authority, host, ref headerBuffer);
 }
 else
 {
Expand All@@ -1450,9 +1477,11 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 WriteIndexedHeader(H2StaticTable.PathSlash, pathAndQuery, ref headerBuffer);
 }

 int headerListSize = 3 * HeaderField.RfcOverhead; // Method, Authority, Path

 if (request.HasHeaders)
 {
 WriteHeaderCollection(request, request.Headers, ref headerBuffer);
headerListSize += WriteHeaderCollection(request, request.Headers, ref headerBuffer);
 }

 // Determine cookies to send.
Expand All@@ -1462,9 +1491,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 if (cookiesFromContainer != string.Empty)
 {
 WriteBytes(KnownHeaders.Cookie.Http2EncodedName, ref headerBuffer);

 Encoding? cookieEncoding = _pool.Settings._requestHeaderEncodingSelector?.Invoke(KnownHeaders.Cookie.Name, request);
 WriteLiteralHeaderValue(cookiesFromContainer, cookieEncoding, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.Cookie.Length + HeaderField.RfcOverhead;
 }
 }

Expand All@@ -1476,11 +1505,24 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 {
 WriteBytes(KnownHeaders.ContentLength.Http2EncodedName, ref headerBuffer);
 WriteLiteralHeaderValue("0", valueEncoding: null, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.ContentLength.Length + HeaderField.RfcOverhead;
 }
 }
 else
 {
 WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 headerListSize += WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 }

 // The headerListSize is an approximation of the total header length.
 // This is acceptable as long as the value is always >= the actual length.
 // We must avoid ever sending more than the server allowed.
 // This approach must be revisted if we ever support the dynamic table or compression when sending requests.
 headerListSize += headerBuffer.ActiveLength;

 uint maxHeaderListSize = _maxHeaderListSize;
 if ((uint)headerListSize > maxHeaderListSize)
 {
 throw new HttpRequestException(SR.Format(SR.net_http_request_headers_exceeded_length, maxHeaderListSize));
 }
 }

Expand DownExpand Up@@ -1553,10 +1595,10 @@ private async ValueTask<Http2Stream> SendHeadersAsync(HttpRequestMessage request
 // streams are created and started in order.
 await PerformWriteAsync(totalSize, (thisRef: this, http2Stream, headerBytes, endStream: (request.Content == null), mustFlush), static (s, writeBuffer) =>
 {
 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 s.thisRef.AddStream(s.http2Stream);

 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 Span<byte> span = writeBuffer.Span;

 // Copy the HEADERS frame.
Expand Down

8 changes: 8 additions & 0 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnectionPool.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -96,6 +96,14 @@ internal sealed class HttpConnectionPool : IDisposable
 private SemaphoreSlim? _http3ConnectionCreateLock;
 internal readonly byte[]? _http3EncodedAuthorityHostHeader;

 // These settings are advertised by the server via SETTINGS_MAX_HEADER_LIST_SIZE.
 // If we had previous connections to the same host in this pool, memorize the last value seen.
 // This value is used as an initial value for new connections before they have a chance to observe the SETTINGS frame.
 // Doing so avoids immediately exceeding the server limit on the first request, potentially causing the connection to be torn down.
 // 0 means there were no previous connections, or they hadn't advertised this limit.
 // There is no need to lock when updating these values - we're only interested in saving _a_ value, not necessarily the min/max/last.
 internal uint _lastSeenHttp2MaxHeaderListSize;

 /// <summary>For non-proxy connection pools, this is the host name in bytes; for proxies, null.</summary>
 private readonly byte[]? _hostHeaderValueBytes;
 /// <summary>Options specialized and cached for this pool and its key.</summary>
Expand Down

101 changes: 101 additions & 0 deletions
src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1205,6 +1205,107 @@ public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLengt
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Test(ITestOutputHelper output) : base(output) { }
 }

 [ConditionalClass(typeof(SocketsHttpHandler), nameof(SocketsHttpHandler.IsSupported))]
 public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2 : HttpClientHandlerTestBase
 {
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2(ITestOutputHelper output) : base(output) { }
 protected override Version UseVersion => HttpVersion.Version20;

 [Fact]
 public async Task ServerAdvertisedMaxHeaderListSize_IsHonoredByClient()
 {
 const int Limit = 10_000;

 using HttpClientHandler handler = CreateHttpClientHandler();
 using HttpClient client = CreateHttpClient(handler);

 // We want to test that the client remembered the setting it received from the previous connection.
 // To do this, we trick the client into using the same HttpConnectionPool for both server connections.
 Uri lastServerUri = null;

 GetUnderlyingSocketsHttpHandler(handler).ConnectCallback = async (context, ct) =>
 {
 Assert.Equal("foo", context.DnsEndPoint.Host);

 Socket socket = new Socket(SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
 try
 {
 await socket.ConnectAsync(lastServerUri.IdnHost, lastServerUri.Port);
 return new NetworkStream(socket, ownsSocket: true);
 }
 catch
 {
 socket.Dispose();
 throw;
 }
 };

 TaskCompletionSource waitingForLastRequest = new(TaskCreationOptions.RunContinuationsAsynchronously);

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 // Send a dummy request to ensure the SETTINGS frame has been received.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 for (int i = 0; i < Limit / 40; i++)
 {
 request.Headers.Add($"Foo-{i}", "");
 }

 ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 await waitingForLastRequest.Task.WaitAsync(TimeSpan.FromSeconds(10));

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 var setting = new SettingsEntry { SettingId = SettingId.MaxHeaderListSize, Value = Limit };

 using GenericLoopbackConnection connection = await ((Http2LoopbackServer)server).EstablishConnectionAsync(setting);

 await connection.ReadRequestDataAsync();
 await connection.SendResponseAsync(content: "Hello world");

 waitingForLastRequest.SetResult();

 // HandleRequestAsync will close the connection
 await connection.HandleRequestAsync(content: "Hello world");
 });

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 await server.HandleRequestAsync(content: "Hello world");
 });
 }
 }

 [SkipOnPlatform(TestPlatforms.Browser, "Socket is not supported on Browser")]
 public sealed class SocketsHttpHandler_HttpClientHandler_Authentication_Test : HttpClientHandler_Authentication_Test
 {
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Highlight search terms from Google/DuckDuckGo/Bing referrer
(function() {
var ref = document.referrer;
var terms = [];
if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {
var url = new URL(ref);
var q = url.searchParams.get('q') || url.searchParams.get('p');
if (q) {
terms = q.split(/\s+/).filter(function(t) { return t.length > 2; });
}
}
if (terms.length === 0) return;
var style = document.createElement('style');
style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';
document.head.appendChild(style);
function highlight(node) {
if (node.nodeType === 3) { // text node
var text = node.textContent;
var found = false;
terms.forEach(function(term) {
var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\]\\]/g, '\\') + ')', 'gi');
if (regex.test(text)) {
found = true;
var frag = document.createDocumentFragment();
var parts = text.split(regex);
parts.forEach(function(part, i) {
if (i % 2 === 0) {
frag.appendChild(document.createTextNode(part));
} else {
var span = document.createElement('span');
span.className = 'userscript-highlight';
span.textContent = part;
frag.appendChild(span);
}
});
node.parentNode.replaceChild(frag, node);
}
});
} else if (node.nodeType === 1 && node.childNodes) { // element
var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];
if (!skipTags.includes(node.tagName)) {
Array.from(node.childNodes).forEach(highlight);
}
}
}
highlight(document.body);
// Re-highlight on dynamic content
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1 || node.nodeType === 3) highlight(node);
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2 by MihaZupan · Pull Request #79997 · dotnet/runtime · GitHub
Skip to content
[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2#79997

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 Merged

carlossanlop
merged 1 commit into

from

Jan 5, 2023
 Merged


[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2
#79997
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3 changes: 3 additions & 0 deletions
src/libraries/System.Net.Http/src/Resources/Strings.resx

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -360,6 +360,9 @@
 <data name="net_http_buffer_insufficient_length" xml:space="preserve">
 <value>The buffer was not long enough.</value>
 </data>
 <data name="net_http_request_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP request headers length exceeded the server limit of {0} bytes.</value>
 </data>
 <data name="net_http_response_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP response headers length exceeded the set limit of {0} bytes.</value>
 </data>
Expand Down

60 changes: 51 additions & 9 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -50,6 +50,10 @@ internal sealed partial class Http2Connection : HttpConnectionBase
 private readonly Channel<WriteQueueEntry> _writeChannel;
 private bool _lastPendingWriterShouldFlush;

 // Server-advertised SETTINGS_MAX_HEADER_LIST_SIZE
 // https://www.rfc-editor.org/rfc/rfc9113.html#section-6.5.2-2.12.1
 private uint _maxHeaderListSize = uint.MaxValue; // Defaults to infinite

 // This flag indicates that the connection is shutting down and cannot accept new requests, because of one of the following conditions:
 // (1) We received a GOAWAY frame from the server
 // (2) We have exhaustead StreamIds (i.e. _nextStream == MaxStreamId)
Expand DownExpand Up@@ -156,6 +160,14 @@ public Http2Connection(HttpConnectionPool pool, Stream stream)
 _nextPingRequestTimestamp = Environment.TickCount64 + _keepAlivePingDelay;
 _keepAlivePingPolicy = _pool.Settings._keepAlivePingPolicy;

 uint maxHeaderListSize = _pool._lastSeenHttp2MaxHeaderListSize;
 if (maxHeaderListSize > 0)
 {
 // Previous connections to the same host advertised a limit.
 // Use this as an initial value before we receive the SETTINGS frame.
 _maxHeaderListSize = maxHeaderListSize;
 }

 if (HttpTelemetry.Log.IsEnabled())
 {
 HttpTelemetry.Log.Http20ConnectionEstablished();
Expand DownExpand Up@@ -800,6 +812,8 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 uint settingValue = BinaryPrimitives.ReadUInt32BigEndian(settings);
 settings = settings.Slice(4);

 if (NetEventSource.Log.IsEnabled()) Trace($"Applying setting {(SettingId)settingId}={settingValue}");

 switch ((SettingId)settingId)
 {
 case SettingId.MaxConcurrentStreams:
Expand All@@ -825,6 +839,11 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 // We don't actually store this value; we always send frames of the minimum size (16K).
 break;

 case SettingId.MaxHeaderListSize:
 _maxHeaderListSize = settingValue;
 _pool._lastSeenHttp2MaxHeaderListSize = _maxHeaderListSize;
 break;

 default:
 // All others are ignored because we don't care about them.
 // Note, per RFC, unknown settings IDs should be ignored.
Expand DownExpand Up@@ -1332,17 +1351,19 @@ private void WriteBytes(ReadOnlySpan<byte> bytes, ref ArrayBuffer headerBuffer)
 headerBuffer.Commit(bytes.Length);
 }

 private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 private int WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 {
 if (NetEventSource.Log.IsEnabled()) Trace("");

 if (headers.HeaderStore is null)
 {
 return;
 return 0;
 }

 HeaderEncodingSelector<HttpRequestMessage>? encodingSelector = _pool.Settings._requestHeaderEncodingSelector;

 int headerListSize = headers.HeaderStore.Count * HeaderField.RfcOverhead;

 ref string[]? tmpHeaderValuesArray = ref t_headerValues;
 foreach (KeyValuePair<HeaderDescriptor, object> header in headers.HeaderStore)
 {
Expand All@@ -1360,6 +1381,10 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 // The Connection, Upgrade and ProxyConnection headers are also not supported in HTTP2.
 if (knownHeader != KnownHeaders.Host && knownHeader != KnownHeaders.Connection && knownHeader != KnownHeaders.Upgrade && knownHeader != KnownHeaders.ProxyConnection)
 {
 // The length of the encoded name may be shorter than the actual name.
 // Ensure that headerListSize is always >= of the actual size.
 headerListSize += knownHeader.Name.Length;

 if (header.Key.KnownHeader == KnownHeaders.TE)
 {
 // HTTP/2 allows only 'trailers' TE header. rfc7540 8.1.2.2
Expand DownExpand Up@@ -1400,6 +1425,8 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 WriteLiteralHeader(header.Key.Name, headerValues, valueEncoding, ref headerBuffer);
 }
 }

 return headerListSize;
 }

 private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuffer)
Expand DownExpand Up@@ -1430,9 +1457,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff

 WriteIndexedHeader(_stream is SslStream ? H2StaticTable.SchemeHttps : H2StaticTable.SchemeHttp, ref headerBuffer);

 if (request.HasHeaders && request.Headers.Host != null)
 if (request.HasHeaders && request.Headers.Host is string host)
 {
 WriteIndexedHeader(H2StaticTable.Authority, request.Headers.Host, ref headerBuffer);
 WriteIndexedHeader(H2StaticTable.Authority, host, ref headerBuffer);
 }
 else
 {
Expand All@@ -1450,9 +1477,11 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 WriteIndexedHeader(H2StaticTable.PathSlash, pathAndQuery, ref headerBuffer);
 }

 int headerListSize = 3 * HeaderField.RfcOverhead; // Method, Authority, Path

 if (request.HasHeaders)
 {
 WriteHeaderCollection(request, request.Headers, ref headerBuffer);
headerListSize += WriteHeaderCollection(request, request.Headers, ref headerBuffer);
 }

 // Determine cookies to send.
Expand All@@ -1462,9 +1491,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 if (cookiesFromContainer != string.Empty)
 {
 WriteBytes(KnownHeaders.Cookie.Http2EncodedName, ref headerBuffer);

 Encoding? cookieEncoding = _pool.Settings._requestHeaderEncodingSelector?.Invoke(KnownHeaders.Cookie.Name, request);
 WriteLiteralHeaderValue(cookiesFromContainer, cookieEncoding, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.Cookie.Length + HeaderField.RfcOverhead;
 }
 }

Expand All@@ -1476,11 +1505,24 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 {
 WriteBytes(KnownHeaders.ContentLength.Http2EncodedName, ref headerBuffer);
 WriteLiteralHeaderValue("0", valueEncoding: null, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.ContentLength.Length + HeaderField.RfcOverhead;
 }
 }
 else
 {
 WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 headerListSize += WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 }

 // The headerListSize is an approximation of the total header length.
 // This is acceptable as long as the value is always >= the actual length.
 // We must avoid ever sending more than the server allowed.
 // This approach must be revisted if we ever support the dynamic table or compression when sending requests.
 headerListSize += headerBuffer.ActiveLength;

 uint maxHeaderListSize = _maxHeaderListSize;
 if ((uint)headerListSize > maxHeaderListSize)
 {
 throw new HttpRequestException(SR.Format(SR.net_http_request_headers_exceeded_length, maxHeaderListSize));
 }
 }

Expand DownExpand Up@@ -1553,10 +1595,10 @@ private async ValueTask<Http2Stream> SendHeadersAsync(HttpRequestMessage request
 // streams are created and started in order.
 await PerformWriteAsync(totalSize, (thisRef: this, http2Stream, headerBytes, endStream: (request.Content == null), mustFlush), static (s, writeBuffer) =>
 {
 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 s.thisRef.AddStream(s.http2Stream);

 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 Span<byte> span = writeBuffer.Span;

 // Copy the HEADERS frame.
Expand Down

8 changes: 8 additions & 0 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnectionPool.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -96,6 +96,14 @@ internal sealed class HttpConnectionPool : IDisposable
 private SemaphoreSlim? _http3ConnectionCreateLock;
 internal readonly byte[]? _http3EncodedAuthorityHostHeader;

 // These settings are advertised by the server via SETTINGS_MAX_HEADER_LIST_SIZE.
 // If we had previous connections to the same host in this pool, memorize the last value seen.
 // This value is used as an initial value for new connections before they have a chance to observe the SETTINGS frame.
 // Doing so avoids immediately exceeding the server limit on the first request, potentially causing the connection to be torn down.
 // 0 means there were no previous connections, or they hadn't advertised this limit.
 // There is no need to lock when updating these values - we're only interested in saving _a_ value, not necessarily the min/max/last.
 internal uint _lastSeenHttp2MaxHeaderListSize;

 /// <summary>For non-proxy connection pools, this is the host name in bytes; for proxies, null.</summary>
 private readonly byte[]? _hostHeaderValueBytes;
 /// <summary>Options specialized and cached for this pool and its key.</summary>
Expand Down

101 changes: 101 additions & 0 deletions
src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1205,6 +1205,107 @@ public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLengt
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Test(ITestOutputHelper output) : base(output) { }
 }

 [ConditionalClass(typeof(SocketsHttpHandler), nameof(SocketsHttpHandler.IsSupported))]
 public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2 : HttpClientHandlerTestBase
 {
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2(ITestOutputHelper output) : base(output) { }
 protected override Version UseVersion => HttpVersion.Version20;

 [Fact]
 public async Task ServerAdvertisedMaxHeaderListSize_IsHonoredByClient()
 {
 const int Limit = 10_000;

 using HttpClientHandler handler = CreateHttpClientHandler();
 using HttpClient client = CreateHttpClient(handler);

 // We want to test that the client remembered the setting it received from the previous connection.
 // To do this, we trick the client into using the same HttpConnectionPool for both server connections.
 Uri lastServerUri = null;

 GetUnderlyingSocketsHttpHandler(handler).ConnectCallback = async (context, ct) =>
 {
 Assert.Equal("foo", context.DnsEndPoint.Host);

 Socket socket = new Socket(SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
 try
 {
 await socket.ConnectAsync(lastServerUri.IdnHost, lastServerUri.Port);
 return new NetworkStream(socket, ownsSocket: true);
 }
 catch
 {
 socket.Dispose();
 throw;
 }
 };

 TaskCompletionSource waitingForLastRequest = new(TaskCreationOptions.RunContinuationsAsynchronously);

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 // Send a dummy request to ensure the SETTINGS frame has been received.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 for (int i = 0; i < Limit / 40; i++)
 {
 request.Headers.Add($"Foo-{i}", "");
 }

 ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 await waitingForLastRequest.Task.WaitAsync(TimeSpan.FromSeconds(10));

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 var setting = new SettingsEntry { SettingId = SettingId.MaxHeaderListSize, Value = Limit };

 using GenericLoopbackConnection connection = await ((Http2LoopbackServer)server).EstablishConnectionAsync(setting);

 await connection.ReadRequestDataAsync();
 await connection.SendResponseAsync(content: "Hello world");

 waitingForLastRequest.SetResult();

 // HandleRequestAsync will close the connection
 await connection.HandleRequestAsync(content: "Hello world");
 });

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 await server.HandleRequestAsync(content: "Hello world");
 });
 }
 }

 [SkipOnPlatform(TestPlatforms.Browser, "Socket is not supported on Browser")]
 public sealed class SocketsHttpHandler_HttpClientHandler_Authentication_Test : HttpClientHandler_Authentication_Test
 {
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Strip utm_, fbclid, gclid, etc. from all links on page
(function() {
var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
function cleanUrl(url) {
try {
var u = new URL(url, window.location.origin);
var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
u.searchParams.delete(p);
changed = true;
}
});
return changed ? u.toString() : url;
} catch (e) {
return url;
}
}
function cleanLinks() {
document.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
cleanLinks();
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1) {
if (node.tagName === 'A') cleanLinks();
node.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2 by MihaZupan · Pull Request #79997 · dotnet/runtime · GitHub
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[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2#79997

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 Merged

carlossanlop
merged 1 commit into

from

Jan 5, 2023
 Merged


[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2
#79997
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3 changes: 3 additions & 0 deletions
src/libraries/System.Net.Http/src/Resources/Strings.resx

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Original file line numberDiff line numberDiff line change
Expand Up@@ -360,6 +360,9 @@
 <data name="net_http_buffer_insufficient_length" xml:space="preserve">
 <value>The buffer was not long enough.</value>
 </data>
 <data name="net_http_request_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP request headers length exceeded the server limit of {0} bytes.</value>
 </data>
 <data name="net_http_response_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP response headers length exceeded the set limit of {0} bytes.</value>
 </data>
Expand Down

60 changes: 51 additions & 9 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -50,6 +50,10 @@ internal sealed partial class Http2Connection : HttpConnectionBase
 private readonly Channel<WriteQueueEntry> _writeChannel;
 private bool _lastPendingWriterShouldFlush;

 // Server-advertised SETTINGS_MAX_HEADER_LIST_SIZE
 // https://www.rfc-editor.org/rfc/rfc9113.html#section-6.5.2-2.12.1
 private uint _maxHeaderListSize = uint.MaxValue; // Defaults to infinite

 // This flag indicates that the connection is shutting down and cannot accept new requests, because of one of the following conditions:
 // (1) We received a GOAWAY frame from the server
 // (2) We have exhaustead StreamIds (i.e. _nextStream == MaxStreamId)
Expand DownExpand Up@@ -156,6 +160,14 @@ public Http2Connection(HttpConnectionPool pool, Stream stream)
 _nextPingRequestTimestamp = Environment.TickCount64 + _keepAlivePingDelay;
 _keepAlivePingPolicy = _pool.Settings._keepAlivePingPolicy;

 uint maxHeaderListSize = _pool._lastSeenHttp2MaxHeaderListSize;
 if (maxHeaderListSize > 0)
 {
 // Previous connections to the same host advertised a limit.
 // Use this as an initial value before we receive the SETTINGS frame.
 _maxHeaderListSize = maxHeaderListSize;
 }

 if (HttpTelemetry.Log.IsEnabled())
 {
 HttpTelemetry.Log.Http20ConnectionEstablished();
Expand DownExpand Up@@ -800,6 +812,8 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 uint settingValue = BinaryPrimitives.ReadUInt32BigEndian(settings);
 settings = settings.Slice(4);

 if (NetEventSource.Log.IsEnabled()) Trace($"Applying setting {(SettingId)settingId}={settingValue}");

 switch ((SettingId)settingId)
 {
 case SettingId.MaxConcurrentStreams:
Expand All@@ -825,6 +839,11 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 // We don't actually store this value; we always send frames of the minimum size (16K).
 break;

 case SettingId.MaxHeaderListSize:
 _maxHeaderListSize = settingValue;
 _pool._lastSeenHttp2MaxHeaderListSize = _maxHeaderListSize;
 break;

 default:
 // All others are ignored because we don't care about them.
 // Note, per RFC, unknown settings IDs should be ignored.
Expand DownExpand Up@@ -1332,17 +1351,19 @@ private void WriteBytes(ReadOnlySpan<byte> bytes, ref ArrayBuffer headerBuffer)
 headerBuffer.Commit(bytes.Length);
 }

 private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 private int WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 {
 if (NetEventSource.Log.IsEnabled()) Trace("");

 if (headers.HeaderStore is null)
 {
 return;
 return 0;
 }

 HeaderEncodingSelector<HttpRequestMessage>? encodingSelector = _pool.Settings._requestHeaderEncodingSelector;

 int headerListSize = headers.HeaderStore.Count * HeaderField.RfcOverhead;

 ref string[]? tmpHeaderValuesArray = ref t_headerValues;
 foreach (KeyValuePair<HeaderDescriptor, object> header in headers.HeaderStore)
 {
Expand All@@ -1360,6 +1381,10 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 // The Connection, Upgrade and ProxyConnection headers are also not supported in HTTP2.
 if (knownHeader != KnownHeaders.Host && knownHeader != KnownHeaders.Connection && knownHeader != KnownHeaders.Upgrade && knownHeader != KnownHeaders.ProxyConnection)
 {
 // The length of the encoded name may be shorter than the actual name.
 // Ensure that headerListSize is always >= of the actual size.
 headerListSize += knownHeader.Name.Length;

 if (header.Key.KnownHeader == KnownHeaders.TE)
 {
 // HTTP/2 allows only 'trailers' TE header. rfc7540 8.1.2.2
Expand DownExpand Up@@ -1400,6 +1425,8 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 WriteLiteralHeader(header.Key.Name, headerValues, valueEncoding, ref headerBuffer);
 }
 }

 return headerListSize;
 }

 private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuffer)
Expand DownExpand Up@@ -1430,9 +1457,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff

 WriteIndexedHeader(_stream is SslStream ? H2StaticTable.SchemeHttps : H2StaticTable.SchemeHttp, ref headerBuffer);

 if (request.HasHeaders && request.Headers.Host != null)
 if (request.HasHeaders && request.Headers.Host is string host)
 {
 WriteIndexedHeader(H2StaticTable.Authority, request.Headers.Host, ref headerBuffer);
 WriteIndexedHeader(H2StaticTable.Authority, host, ref headerBuffer);
 }
 else
 {
Expand All@@ -1450,9 +1477,11 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 WriteIndexedHeader(H2StaticTable.PathSlash, pathAndQuery, ref headerBuffer);
 }

 int headerListSize = 3 * HeaderField.RfcOverhead; // Method, Authority, Path

 if (request.HasHeaders)
 {
 WriteHeaderCollection(request, request.Headers, ref headerBuffer);
headerListSize += WriteHeaderCollection(request, request.Headers, ref headerBuffer);
 }

 // Determine cookies to send.
Expand All@@ -1462,9 +1491,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 if (cookiesFromContainer != string.Empty)
 {
 WriteBytes(KnownHeaders.Cookie.Http2EncodedName, ref headerBuffer);

 Encoding? cookieEncoding = _pool.Settings._requestHeaderEncodingSelector?.Invoke(KnownHeaders.Cookie.Name, request);
 WriteLiteralHeaderValue(cookiesFromContainer, cookieEncoding, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.Cookie.Length + HeaderField.RfcOverhead;
 }
 }

Expand All@@ -1476,11 +1505,24 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 {
 WriteBytes(KnownHeaders.ContentLength.Http2EncodedName, ref headerBuffer);
 WriteLiteralHeaderValue("0", valueEncoding: null, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.ContentLength.Length + HeaderField.RfcOverhead;
 }
 }
 else
 {
 WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 headerListSize += WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 }

 // The headerListSize is an approximation of the total header length.
 // This is acceptable as long as the value is always >= the actual length.
 // We must avoid ever sending more than the server allowed.
 // This approach must be revisted if we ever support the dynamic table or compression when sending requests.
 headerListSize += headerBuffer.ActiveLength;

 uint maxHeaderListSize = _maxHeaderListSize;
 if ((uint)headerListSize > maxHeaderListSize)
 {
 throw new HttpRequestException(SR.Format(SR.net_http_request_headers_exceeded_length, maxHeaderListSize));
 }
 }

Expand DownExpand Up@@ -1553,10 +1595,10 @@ private async ValueTask<Http2Stream> SendHeadersAsync(HttpRequestMessage request
 // streams are created and started in order.
 await PerformWriteAsync(totalSize, (thisRef: this, http2Stream, headerBytes, endStream: (request.Content == null), mustFlush), static (s, writeBuffer) =>
 {
 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 s.thisRef.AddStream(s.http2Stream);

 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 Span<byte> span = writeBuffer.Span;

 // Copy the HEADERS frame.
Expand Down

8 changes: 8 additions & 0 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnectionPool.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -96,6 +96,14 @@ internal sealed class HttpConnectionPool : IDisposable
 private SemaphoreSlim? _http3ConnectionCreateLock;
 internal readonly byte[]? _http3EncodedAuthorityHostHeader;

 // These settings are advertised by the server via SETTINGS_MAX_HEADER_LIST_SIZE.
 // If we had previous connections to the same host in this pool, memorize the last value seen.
 // This value is used as an initial value for new connections before they have a chance to observe the SETTINGS frame.
 // Doing so avoids immediately exceeding the server limit on the first request, potentially causing the connection to be torn down.
 // 0 means there were no previous connections, or they hadn't advertised this limit.
 // There is no need to lock when updating these values - we're only interested in saving _a_ value, not necessarily the min/max/last.
 internal uint _lastSeenHttp2MaxHeaderListSize;

 /// <summary>For non-proxy connection pools, this is the host name in bytes; for proxies, null.</summary>
 private readonly byte[]? _hostHeaderValueBytes;
 /// <summary>Options specialized and cached for this pool and its key.</summary>
Expand Down

101 changes: 101 additions & 0 deletions
src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1205,6 +1205,107 @@ public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLengt
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Test(ITestOutputHelper output) : base(output) { }
 }

 [ConditionalClass(typeof(SocketsHttpHandler), nameof(SocketsHttpHandler.IsSupported))]
 public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2 : HttpClientHandlerTestBase
 {
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2(ITestOutputHelper output) : base(output) { }
 protected override Version UseVersion => HttpVersion.Version20;

 [Fact]
 public async Task ServerAdvertisedMaxHeaderListSize_IsHonoredByClient()
 {
 const int Limit = 10_000;

 using HttpClientHandler handler = CreateHttpClientHandler();
 using HttpClient client = CreateHttpClient(handler);

 // We want to test that the client remembered the setting it received from the previous connection.
 // To do this, we trick the client into using the same HttpConnectionPool for both server connections.
 Uri lastServerUri = null;

 GetUnderlyingSocketsHttpHandler(handler).ConnectCallback = async (context, ct) =>
 {
 Assert.Equal("foo", context.DnsEndPoint.Host);

 Socket socket = new Socket(SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
 try
 {
 await socket.ConnectAsync(lastServerUri.IdnHost, lastServerUri.Port);
 return new NetworkStream(socket, ownsSocket: true);
 }
 catch
 {
 socket.Dispose();
 throw;
 }
 };

 TaskCompletionSource waitingForLastRequest = new(TaskCreationOptions.RunContinuationsAsynchronously);

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 // Send a dummy request to ensure the SETTINGS frame has been received.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 for (int i = 0; i < Limit / 40; i++)
 {
 request.Headers.Add($"Foo-{i}", "");
 }

 ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 await waitingForLastRequest.Task.WaitAsync(TimeSpan.FromSeconds(10));

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 var setting = new SettingsEntry { SettingId = SettingId.MaxHeaderListSize, Value = Limit };

 using GenericLoopbackConnection connection = await ((Http2LoopbackServer)server).EstablishConnectionAsync(setting);

 await connection.ReadRequestDataAsync();
 await connection.SendResponseAsync(content: "Hello world");

 waitingForLastRequest.SetResult();

 // HandleRequestAsync will close the connection
 await connection.HandleRequestAsync(content: "Hello world");
 });

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 await server.HandleRequestAsync(content: "Hello world");
 });
 }
 }

 [SkipOnPlatform(TestPlatforms.Browser, "Socket is not supported on Browser")]
 public sealed class SocketsHttpHandler_HttpClientHandler_Authentication_Test : HttpClientHandler_Authentication_Test
 {
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Auto-enable theater mode on YouTube
(function() {
function tryTheater() {
var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
if (btn && !btn.classList.contains('activated')) {
btn.click();
}
}
// Try immediately
tryTheater();
// Try after navigation (SPA)
var lastUrl = location.href;
setInterval(function() {
if (location.href !== lastUrl) {
lastUrl = location.href;
setTimeout(tryTheater, 500);
}
}, 1000);
// Also try on player load
var observer = new MutationObserver(tryTheater);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2 by MihaZupan · Pull Request #79997 · dotnet/runtime · GitHub
Skip to content
[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2#79997

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Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

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By clicking “Sign up for GitHub”, you agree to our terms of service and
privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
Sign in
to your account

 Merged

carlossanlop
merged 1 commit into

from

Jan 5, 2023
 Merged


[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2
#79997
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3 changes: 3 additions & 0 deletions
src/libraries/System.Net.Http/src/Resources/Strings.resx

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Original file line numberDiff line numberDiff line change
Expand Up@@ -360,6 +360,9 @@
 <data name="net_http_buffer_insufficient_length" xml:space="preserve">
 <value>The buffer was not long enough.</value>
 </data>
 <data name="net_http_request_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP request headers length exceeded the server limit of {0} bytes.</value>
 </data>
 <data name="net_http_response_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP response headers length exceeded the set limit of {0} bytes.</value>
 </data>
Expand Down

60 changes: 51 additions & 9 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -50,6 +50,10 @@ internal sealed partial class Http2Connection : HttpConnectionBase
 private readonly Channel<WriteQueueEntry> _writeChannel;
 private bool _lastPendingWriterShouldFlush;

 // Server-advertised SETTINGS_MAX_HEADER_LIST_SIZE
 // https://www.rfc-editor.org/rfc/rfc9113.html#section-6.5.2-2.12.1
 private uint _maxHeaderListSize = uint.MaxValue; // Defaults to infinite

 // This flag indicates that the connection is shutting down and cannot accept new requests, because of one of the following conditions:
 // (1) We received a GOAWAY frame from the server
 // (2) We have exhaustead StreamIds (i.e. _nextStream == MaxStreamId)
Expand DownExpand Up@@ -156,6 +160,14 @@ public Http2Connection(HttpConnectionPool pool, Stream stream)
 _nextPingRequestTimestamp = Environment.TickCount64 + _keepAlivePingDelay;
 _keepAlivePingPolicy = _pool.Settings._keepAlivePingPolicy;

 uint maxHeaderListSize = _pool._lastSeenHttp2MaxHeaderListSize;
 if (maxHeaderListSize > 0)
 {
 // Previous connections to the same host advertised a limit.
 // Use this as an initial value before we receive the SETTINGS frame.
 _maxHeaderListSize = maxHeaderListSize;
 }

 if (HttpTelemetry.Log.IsEnabled())
 {
 HttpTelemetry.Log.Http20ConnectionEstablished();
Expand DownExpand Up@@ -800,6 +812,8 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 uint settingValue = BinaryPrimitives.ReadUInt32BigEndian(settings);
 settings = settings.Slice(4);

 if (NetEventSource.Log.IsEnabled()) Trace($"Applying setting {(SettingId)settingId}={settingValue}");

 switch ((SettingId)settingId)
 {
 case SettingId.MaxConcurrentStreams:
Expand All@@ -825,6 +839,11 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 // We don't actually store this value; we always send frames of the minimum size (16K).
 break;

 case SettingId.MaxHeaderListSize:
 _maxHeaderListSize = settingValue;
 _pool._lastSeenHttp2MaxHeaderListSize = _maxHeaderListSize;
 break;

 default:
 // All others are ignored because we don't care about them.
 // Note, per RFC, unknown settings IDs should be ignored.
Expand DownExpand Up@@ -1332,17 +1351,19 @@ private void WriteBytes(ReadOnlySpan<byte> bytes, ref ArrayBuffer headerBuffer)
 headerBuffer.Commit(bytes.Length);
 }

 private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 private int WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 {
 if (NetEventSource.Log.IsEnabled()) Trace("");

 if (headers.HeaderStore is null)
 {
 return;
 return 0;
 }

 HeaderEncodingSelector<HttpRequestMessage>? encodingSelector = _pool.Settings._requestHeaderEncodingSelector;

 int headerListSize = headers.HeaderStore.Count * HeaderField.RfcOverhead;

 ref string[]? tmpHeaderValuesArray = ref t_headerValues;
 foreach (KeyValuePair<HeaderDescriptor, object> header in headers.HeaderStore)
 {
Expand All@@ -1360,6 +1381,10 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 // The Connection, Upgrade and ProxyConnection headers are also not supported in HTTP2.
 if (knownHeader != KnownHeaders.Host && knownHeader != KnownHeaders.Connection && knownHeader != KnownHeaders.Upgrade && knownHeader != KnownHeaders.ProxyConnection)
 {
 // The length of the encoded name may be shorter than the actual name.
 // Ensure that headerListSize is always >= of the actual size.
 headerListSize += knownHeader.Name.Length;

 if (header.Key.KnownHeader == KnownHeaders.TE)
 {
 // HTTP/2 allows only 'trailers' TE header. rfc7540 8.1.2.2
Expand DownExpand Up@@ -1400,6 +1425,8 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 WriteLiteralHeader(header.Key.Name, headerValues, valueEncoding, ref headerBuffer);
 }
 }

 return headerListSize;
 }

 private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuffer)
Expand DownExpand Up@@ -1430,9 +1457,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff

 WriteIndexedHeader(_stream is SslStream ? H2StaticTable.SchemeHttps : H2StaticTable.SchemeHttp, ref headerBuffer);

 if (request.HasHeaders && request.Headers.Host != null)
 if (request.HasHeaders && request.Headers.Host is string host)
 {
 WriteIndexedHeader(H2StaticTable.Authority, request.Headers.Host, ref headerBuffer);
 WriteIndexedHeader(H2StaticTable.Authority, host, ref headerBuffer);
 }
 else
 {
Expand All@@ -1450,9 +1477,11 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 WriteIndexedHeader(H2StaticTable.PathSlash, pathAndQuery, ref headerBuffer);
 }

 int headerListSize = 3 * HeaderField.RfcOverhead; // Method, Authority, Path

 if (request.HasHeaders)
 {
 WriteHeaderCollection(request, request.Headers, ref headerBuffer);
headerListSize += WriteHeaderCollection(request, request.Headers, ref headerBuffer);
 }

 // Determine cookies to send.
Expand All@@ -1462,9 +1491,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 if (cookiesFromContainer != string.Empty)
 {
 WriteBytes(KnownHeaders.Cookie.Http2EncodedName, ref headerBuffer);

 Encoding? cookieEncoding = _pool.Settings._requestHeaderEncodingSelector?.Invoke(KnownHeaders.Cookie.Name, request);
 WriteLiteralHeaderValue(cookiesFromContainer, cookieEncoding, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.Cookie.Length + HeaderField.RfcOverhead;
 }
 }

Expand All@@ -1476,11 +1505,24 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 {
 WriteBytes(KnownHeaders.ContentLength.Http2EncodedName, ref headerBuffer);
 WriteLiteralHeaderValue("0", valueEncoding: null, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.ContentLength.Length + HeaderField.RfcOverhead;
 }
 }
 else
 {
 WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 headerListSize += WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 }

 // The headerListSize is an approximation of the total header length.
 // This is acceptable as long as the value is always >= the actual length.
 // We must avoid ever sending more than the server allowed.
 // This approach must be revisted if we ever support the dynamic table or compression when sending requests.
 headerListSize += headerBuffer.ActiveLength;

 uint maxHeaderListSize = _maxHeaderListSize;
 if ((uint)headerListSize > maxHeaderListSize)
 {
 throw new HttpRequestException(SR.Format(SR.net_http_request_headers_exceeded_length, maxHeaderListSize));
 }
 }

Expand DownExpand Up@@ -1553,10 +1595,10 @@ private async ValueTask<Http2Stream> SendHeadersAsync(HttpRequestMessage request
 // streams are created and started in order.
 await PerformWriteAsync(totalSize, (thisRef: this, http2Stream, headerBytes, endStream: (request.Content == null), mustFlush), static (s, writeBuffer) =>
 {
 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 s.thisRef.AddStream(s.http2Stream);

 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 Span<byte> span = writeBuffer.Span;

 // Copy the HEADERS frame.
Expand Down

8 changes: 8 additions & 0 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnectionPool.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -96,6 +96,14 @@ internal sealed class HttpConnectionPool : IDisposable
 private SemaphoreSlim? _http3ConnectionCreateLock;
 internal readonly byte[]? _http3EncodedAuthorityHostHeader;

 // These settings are advertised by the server via SETTINGS_MAX_HEADER_LIST_SIZE.
 // If we had previous connections to the same host in this pool, memorize the last value seen.
 // This value is used as an initial value for new connections before they have a chance to observe the SETTINGS frame.
 // Doing so avoids immediately exceeding the server limit on the first request, potentially causing the connection to be torn down.
 // 0 means there were no previous connections, or they hadn't advertised this limit.
 // There is no need to lock when updating these values - we're only interested in saving _a_ value, not necessarily the min/max/last.
 internal uint _lastSeenHttp2MaxHeaderListSize;

 /// <summary>For non-proxy connection pools, this is the host name in bytes; for proxies, null.</summary>
 private readonly byte[]? _hostHeaderValueBytes;
 /// <summary>Options specialized and cached for this pool and its key.</summary>
Expand Down

101 changes: 101 additions & 0 deletions
src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1205,6 +1205,107 @@ public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLengt
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Test(ITestOutputHelper output) : base(output) { }
 }

 [ConditionalClass(typeof(SocketsHttpHandler), nameof(SocketsHttpHandler.IsSupported))]
 public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2 : HttpClientHandlerTestBase
 {
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2(ITestOutputHelper output) : base(output) { }
 protected override Version UseVersion => HttpVersion.Version20;

 [Fact]
 public async Task ServerAdvertisedMaxHeaderListSize_IsHonoredByClient()
 {
 const int Limit = 10_000;

 using HttpClientHandler handler = CreateHttpClientHandler();
 using HttpClient client = CreateHttpClient(handler);

 // We want to test that the client remembered the setting it received from the previous connection.
 // To do this, we trick the client into using the same HttpConnectionPool for both server connections.
 Uri lastServerUri = null;

 GetUnderlyingSocketsHttpHandler(handler).ConnectCallback = async (context, ct) =>
 {
 Assert.Equal("foo", context.DnsEndPoint.Host);

 Socket socket = new Socket(SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
 try
 {
 await socket.ConnectAsync(lastServerUri.IdnHost, lastServerUri.Port);
 return new NetworkStream(socket, ownsSocket: true);
 }
 catch
 {
 socket.Dispose();
 throw;
 }
 };

 TaskCompletionSource waitingForLastRequest = new(TaskCreationOptions.RunContinuationsAsynchronously);

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 // Send a dummy request to ensure the SETTINGS frame has been received.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 for (int i = 0; i < Limit / 40; i++)
 {
 request.Headers.Add($"Foo-{i}", "");
 }

 ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 await waitingForLastRequest.Task.WaitAsync(TimeSpan.FromSeconds(10));

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 var setting = new SettingsEntry { SettingId = SettingId.MaxHeaderListSize, Value = Limit };

 using GenericLoopbackConnection connection = await ((Http2LoopbackServer)server).EstablishConnectionAsync(setting);

 await connection.ReadRequestDataAsync();
 await connection.SendResponseAsync(content: "Hello world");

 waitingForLastRequest.SetResult();

 // HandleRequestAsync will close the connection
 await connection.HandleRequestAsync(content: "Hello world");
 });

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 await server.HandleRequestAsync(content: "Hello world");
 });
 }
 }

 [SkipOnPlatform(TestPlatforms.Browser, "Socket is not supported on Browser")]
 public sealed class SocketsHttpHandler_HttpClientHandler_Authentication_Test : HttpClientHandler_Authentication_Test
 {
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Remove or un-stick sticky/fixed headers that block content
(function() {
function unstick() {
document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {
el.style.position = 'static';
el.style.top = 'auto';
el.style.zIndex = 'auto';
}
});
}
unstick();
var observer = new MutationObserver(unstick);
observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
})();
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2 by MihaZupan · Pull Request #79997 · dotnet/runtime · GitHub
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[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2#79997

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 Merged

carlossanlop
merged 1 commit into

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Jan 5, 2023
 Merged


[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2
#79997
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3 changes: 3 additions & 0 deletions
src/libraries/System.Net.Http/src/Resources/Strings.resx

View file


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Original file line numberDiff line numberDiff line change
Expand Up@@ -360,6 +360,9 @@
 <data name="net_http_buffer_insufficient_length" xml:space="preserve">
 <value>The buffer was not long enough.</value>
 </data>
 <data name="net_http_request_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP request headers length exceeded the server limit of {0} bytes.</value>
 </data>
 <data name="net_http_response_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP response headers length exceeded the set limit of {0} bytes.</value>
 </data>
Expand Down

60 changes: 51 additions & 9 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -50,6 +50,10 @@ internal sealed partial class Http2Connection : HttpConnectionBase
 private readonly Channel<WriteQueueEntry> _writeChannel;
 private bool _lastPendingWriterShouldFlush;

 // Server-advertised SETTINGS_MAX_HEADER_LIST_SIZE
 // https://www.rfc-editor.org/rfc/rfc9113.html#section-6.5.2-2.12.1
 private uint _maxHeaderListSize = uint.MaxValue; // Defaults to infinite

 // This flag indicates that the connection is shutting down and cannot accept new requests, because of one of the following conditions:
 // (1) We received a GOAWAY frame from the server
 // (2) We have exhaustead StreamIds (i.e. _nextStream == MaxStreamId)
Expand DownExpand Up@@ -156,6 +160,14 @@ public Http2Connection(HttpConnectionPool pool, Stream stream)
 _nextPingRequestTimestamp = Environment.TickCount64 + _keepAlivePingDelay;
 _keepAlivePingPolicy = _pool.Settings._keepAlivePingPolicy;

 uint maxHeaderListSize = _pool._lastSeenHttp2MaxHeaderListSize;
 if (maxHeaderListSize > 0)
 {
 // Previous connections to the same host advertised a limit.
 // Use this as an initial value before we receive the SETTINGS frame.
 _maxHeaderListSize = maxHeaderListSize;
 }

 if (HttpTelemetry.Log.IsEnabled())
 {
 HttpTelemetry.Log.Http20ConnectionEstablished();
Expand DownExpand Up@@ -800,6 +812,8 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 uint settingValue = BinaryPrimitives.ReadUInt32BigEndian(settings);
 settings = settings.Slice(4);

 if (NetEventSource.Log.IsEnabled()) Trace($"Applying setting {(SettingId)settingId}={settingValue}");

 switch ((SettingId)settingId)
 {
 case SettingId.MaxConcurrentStreams:
Expand All@@ -825,6 +839,11 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 // We don't actually store this value; we always send frames of the minimum size (16K).
 break;

 case SettingId.MaxHeaderListSize:
 _maxHeaderListSize = settingValue;
 _pool._lastSeenHttp2MaxHeaderListSize = _maxHeaderListSize;
 break;

 default:
 // All others are ignored because we don't care about them.
 // Note, per RFC, unknown settings IDs should be ignored.
Expand DownExpand Up@@ -1332,17 +1351,19 @@ private void WriteBytes(ReadOnlySpan<byte> bytes, ref ArrayBuffer headerBuffer)
 headerBuffer.Commit(bytes.Length);
 }

 private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 private int WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 {
 if (NetEventSource.Log.IsEnabled()) Trace("");

 if (headers.HeaderStore is null)
 {
 return;
 return 0;
 }

 HeaderEncodingSelector<HttpRequestMessage>? encodingSelector = _pool.Settings._requestHeaderEncodingSelector;

 int headerListSize = headers.HeaderStore.Count * HeaderField.RfcOverhead;

 ref string[]? tmpHeaderValuesArray = ref t_headerValues;
 foreach (KeyValuePair<HeaderDescriptor, object> header in headers.HeaderStore)
 {
Expand All@@ -1360,6 +1381,10 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 // The Connection, Upgrade and ProxyConnection headers are also not supported in HTTP2.
 if (knownHeader != KnownHeaders.Host && knownHeader != KnownHeaders.Connection && knownHeader != KnownHeaders.Upgrade && knownHeader != KnownHeaders.ProxyConnection)
 {
 // The length of the encoded name may be shorter than the actual name.
 // Ensure that headerListSize is always >= of the actual size.
 headerListSize += knownHeader.Name.Length;

 if (header.Key.KnownHeader == KnownHeaders.TE)
 {
 // HTTP/2 allows only 'trailers' TE header. rfc7540 8.1.2.2
Expand DownExpand Up@@ -1400,6 +1425,8 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 WriteLiteralHeader(header.Key.Name, headerValues, valueEncoding, ref headerBuffer);
 }
 }

 return headerListSize;
 }

 private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuffer)
Expand DownExpand Up@@ -1430,9 +1457,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff

 WriteIndexedHeader(_stream is SslStream ? H2StaticTable.SchemeHttps : H2StaticTable.SchemeHttp, ref headerBuffer);

 if (request.HasHeaders && request.Headers.Host != null)
 if (request.HasHeaders && request.Headers.Host is string host)
 {
 WriteIndexedHeader(H2StaticTable.Authority, request.Headers.Host, ref headerBuffer);
 WriteIndexedHeader(H2StaticTable.Authority, host, ref headerBuffer);
 }
 else
 {
Expand All@@ -1450,9 +1477,11 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 WriteIndexedHeader(H2StaticTable.PathSlash, pathAndQuery, ref headerBuffer);
 }

 int headerListSize = 3 * HeaderField.RfcOverhead; // Method, Authority, Path

 if (request.HasHeaders)
 {
 WriteHeaderCollection(request, request.Headers, ref headerBuffer);
headerListSize += WriteHeaderCollection(request, request.Headers, ref headerBuffer);
 }

 // Determine cookies to send.
Expand All@@ -1462,9 +1491,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 if (cookiesFromContainer != string.Empty)
 {
 WriteBytes(KnownHeaders.Cookie.Http2EncodedName, ref headerBuffer);

 Encoding? cookieEncoding = _pool.Settings._requestHeaderEncodingSelector?.Invoke(KnownHeaders.Cookie.Name, request);
 WriteLiteralHeaderValue(cookiesFromContainer, cookieEncoding, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.Cookie.Length + HeaderField.RfcOverhead;
 }
 }

Expand All@@ -1476,11 +1505,24 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 {
 WriteBytes(KnownHeaders.ContentLength.Http2EncodedName, ref headerBuffer);
 WriteLiteralHeaderValue("0", valueEncoding: null, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.ContentLength.Length + HeaderField.RfcOverhead;
 }
 }
 else
 {
 WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 headerListSize += WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 }

 // The headerListSize is an approximation of the total header length.
 // This is acceptable as long as the value is always >= the actual length.
 // We must avoid ever sending more than the server allowed.
 // This approach must be revisted if we ever support the dynamic table or compression when sending requests.
 headerListSize += headerBuffer.ActiveLength;

 uint maxHeaderListSize = _maxHeaderListSize;
 if ((uint)headerListSize > maxHeaderListSize)
 {
 throw new HttpRequestException(SR.Format(SR.net_http_request_headers_exceeded_length, maxHeaderListSize));
 }
 }

Expand DownExpand Up@@ -1553,10 +1595,10 @@ private async ValueTask<Http2Stream> SendHeadersAsync(HttpRequestMessage request
 // streams are created and started in order.
 await PerformWriteAsync(totalSize, (thisRef: this, http2Stream, headerBytes, endStream: (request.Content == null), mustFlush), static (s, writeBuffer) =>
 {
 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 s.thisRef.AddStream(s.http2Stream);

 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 Span<byte> span = writeBuffer.Span;

 // Copy the HEADERS frame.
Expand Down

8 changes: 8 additions & 0 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnectionPool.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -96,6 +96,14 @@ internal sealed class HttpConnectionPool : IDisposable
 private SemaphoreSlim? _http3ConnectionCreateLock;
 internal readonly byte[]? _http3EncodedAuthorityHostHeader;

 // These settings are advertised by the server via SETTINGS_MAX_HEADER_LIST_SIZE.
 // If we had previous connections to the same host in this pool, memorize the last value seen.
 // This value is used as an initial value for new connections before they have a chance to observe the SETTINGS frame.
 // Doing so avoids immediately exceeding the server limit on the first request, potentially causing the connection to be torn down.
 // 0 means there were no previous connections, or they hadn't advertised this limit.
 // There is no need to lock when updating these values - we're only interested in saving _a_ value, not necessarily the min/max/last.
 internal uint _lastSeenHttp2MaxHeaderListSize;

 /// <summary>For non-proxy connection pools, this is the host name in bytes; for proxies, null.</summary>
 private readonly byte[]? _hostHeaderValueBytes;
 /// <summary>Options specialized and cached for this pool and its key.</summary>
Expand Down

101 changes: 101 additions & 0 deletions
src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1205,6 +1205,107 @@ public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLengt
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Test(ITestOutputHelper output) : base(output) { }
 }

 [ConditionalClass(typeof(SocketsHttpHandler), nameof(SocketsHttpHandler.IsSupported))]
 public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2 : HttpClientHandlerTestBase
 {
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2(ITestOutputHelper output) : base(output) { }
 protected override Version UseVersion => HttpVersion.Version20;

 [Fact]
 public async Task ServerAdvertisedMaxHeaderListSize_IsHonoredByClient()
 {
 const int Limit = 10_000;

 using HttpClientHandler handler = CreateHttpClientHandler();
 using HttpClient client = CreateHttpClient(handler);

 // We want to test that the client remembered the setting it received from the previous connection.
 // To do this, we trick the client into using the same HttpConnectionPool for both server connections.
 Uri lastServerUri = null;

 GetUnderlyingSocketsHttpHandler(handler).ConnectCallback = async (context, ct) =>
 {
 Assert.Equal("foo", context.DnsEndPoint.Host);

 Socket socket = new Socket(SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
 try
 {
 await socket.ConnectAsync(lastServerUri.IdnHost, lastServerUri.Port);
 return new NetworkStream(socket, ownsSocket: true);
 }
 catch
 {
 socket.Dispose();
 throw;
 }
 };

 TaskCompletionSource waitingForLastRequest = new(TaskCreationOptions.RunContinuationsAsynchronously);

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 // Send a dummy request to ensure the SETTINGS frame has been received.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 for (int i = 0; i < Limit / 40; i++)
 {
 request.Headers.Add($"Foo-{i}", "");
 }

 ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 await waitingForLastRequest.Task.WaitAsync(TimeSpan.FromSeconds(10));

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 var setting = new SettingsEntry { SettingId = SettingId.MaxHeaderListSize, Value = Limit };

 using GenericLoopbackConnection connection = await ((Http2LoopbackServer)server).EstablishConnectionAsync(setting);

 await connection.ReadRequestDataAsync();
 await connection.SendResponseAsync(content: "Hello world");

 waitingForLastRequest.SetResult();

 // HandleRequestAsync will close the connection
 await connection.HandleRequestAsync(content: "Hello world");
 });

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 await server.HandleRequestAsync(content: "Hello world");
 });
 }
 }

 [SkipOnPlatform(TestPlatforms.Browser, "Socket is not supported on Browser")]
 public sealed class SocketsHttpHandler_HttpClientHandler_Authentication_Test : HttpClientHandler_Authentication_Test
 {
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Universal Dark Mode - works on any site
(function() {
var enabled = true;
function applyDarkMode() {
if (!enabled) return;
// Create style element if it doesn't exist
var style = document.getElementById('universal-dark-mode-style');
if (!style) {
style = document.createElement('style');
style.id = 'universal-dark-mode-style';
document.head.appendChild(style);
}
// Dark mode CSS - inverts colors but preserves images/video
style.textContent = '
/* Invert everything except media */
html {
filter: invert(1) hue-rotate(180deg) !important;
background: #1a1a2e !important;
}
/* Restore images, videos, iframes, canvas */
img, video, iframe, canvas, svg, picture, [style*="background-image"] {
filter: invert(1) hue-rotate(180deg) !important;
}
/* Preserve specific elements that should not be inverted */
.no-dark-mode, .no-dark-mode *,
[data-theme="light"], [data-theme="light"],
.ace_editor, .ace_editor *,
.CodeMirror, .CodeMirror *,
.monaco-editor, .monaco-editor *,
.markdown-body pre, .markdown-body pre *,
.highlight, .highlight *,
pre code, pre code * {
filter: none !important;
}
/* Fix common UI elements */
.modal, .popup, .dropdown-menu, .tooltip, .popover {
filter: invert(1) hue-rotate(180deg) !important;
background: #2d2d44 !important;
border-color: #444 !important;
}
/* Scrollbars */
::-webkit-scrollbar { background: #1a1a2e !important; }
::-webkit-scrollbar-thumb { background: #444 !important; }
::-webkit-scrollbar-thumb:hover { background: #555 !important; }
/* Selection */
::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
';
}
function removeDarkMode() {
var style = document.getElementById('universal-dark-mode-style');
if (style) style.remove();
}
// Toggle with Alt+Shift+D
document.addEventListener('keydown', function(e) {
if (e.altKey && e.shiftKey && e.key === 'D') {
e.preventDefault();
enabled = !enabled;
if (enabled) {
applyDarkMode();
console.log('[Universal Dark Mode] Enabled');
} else {
removeDarkMode();
console.log('[Universal Dark Mode] Disabled');
}
}
});
// Apply on load
applyDarkMode();
// Re-apply on dynamic content
var observer = new MutationObserver(function(mutations) {
if (enabled && !document.getElementById('universal-dark-mode-style')) {
applyDarkMode();
}
});
observer.observe(document.head, { childList: true });
console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');
})();
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();
[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2 by MihaZupan · Pull Request #79997 · dotnet/runtime · GitHub
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[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2#79997

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 Merged

carlossanlop
merged 1 commit into

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Jan 5, 2023
 Merged


[release/6.0] Respect SETTINGS_MAX_HEADER_LIST_SIZE on HTTP/2
#79997
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3 changes: 3 additions & 0 deletions
src/libraries/System.Net.Http/src/Resources/Strings.resx

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Original file line numberDiff line numberDiff line change
Expand Up@@ -360,6 +360,9 @@
 <data name="net_http_buffer_insufficient_length" xml:space="preserve">
 <value>The buffer was not long enough.</value>
 </data>
 <data name="net_http_request_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP request headers length exceeded the server limit of {0} bytes.</value>
 </data>
 <data name="net_http_response_headers_exceeded_length" xml:space="preserve">
 <value>The HTTP response headers length exceeded the set limit of {0} bytes.</value>
 </data>
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60 changes: 51 additions & 9 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -50,6 +50,10 @@ internal sealed partial class Http2Connection : HttpConnectionBase
 private readonly Channel<WriteQueueEntry> _writeChannel;
 private bool _lastPendingWriterShouldFlush;

 // Server-advertised SETTINGS_MAX_HEADER_LIST_SIZE
 // https://www.rfc-editor.org/rfc/rfc9113.html#section-6.5.2-2.12.1
 private uint _maxHeaderListSize = uint.MaxValue; // Defaults to infinite

 // This flag indicates that the connection is shutting down and cannot accept new requests, because of one of the following conditions:
 // (1) We received a GOAWAY frame from the server
 // (2) We have exhaustead StreamIds (i.e. _nextStream == MaxStreamId)
Expand DownExpand Up@@ -156,6 +160,14 @@ public Http2Connection(HttpConnectionPool pool, Stream stream)
 _nextPingRequestTimestamp = Environment.TickCount64 + _keepAlivePingDelay;
 _keepAlivePingPolicy = _pool.Settings._keepAlivePingPolicy;

 uint maxHeaderListSize = _pool._lastSeenHttp2MaxHeaderListSize;
 if (maxHeaderListSize > 0)
 {
 // Previous connections to the same host advertised a limit.
 // Use this as an initial value before we receive the SETTINGS frame.
 _maxHeaderListSize = maxHeaderListSize;
 }

 if (HttpTelemetry.Log.IsEnabled())
 {
 HttpTelemetry.Log.Http20ConnectionEstablished();
Expand DownExpand Up@@ -800,6 +812,8 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 uint settingValue = BinaryPrimitives.ReadUInt32BigEndian(settings);
 settings = settings.Slice(4);

 if (NetEventSource.Log.IsEnabled()) Trace($"Applying setting {(SettingId)settingId}={settingValue}");

 switch ((SettingId)settingId)
 {
 case SettingId.MaxConcurrentStreams:
Expand All@@ -825,6 +839,11 @@ private void ProcessSettingsFrame(FrameHeader frameHeader, bool initialFrame = f
 // We don't actually store this value; we always send frames of the minimum size (16K).
 break;

 case SettingId.MaxHeaderListSize:
 _maxHeaderListSize = settingValue;
 _pool._lastSeenHttp2MaxHeaderListSize = _maxHeaderListSize;
 break;

 default:
 // All others are ignored because we don't care about them.
 // Note, per RFC, unknown settings IDs should be ignored.
Expand DownExpand Up@@ -1332,17 +1351,19 @@ private void WriteBytes(ReadOnlySpan<byte> bytes, ref ArrayBuffer headerBuffer)
 headerBuffer.Commit(bytes.Length);
 }

 private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 private int WriteHeaderCollection(HttpRequestMessage request, HttpHeaders headers, ref ArrayBuffer headerBuffer)
 {
 if (NetEventSource.Log.IsEnabled()) Trace("");

 if (headers.HeaderStore is null)
 {
 return;
 return 0;
 }

 HeaderEncodingSelector<HttpRequestMessage>? encodingSelector = _pool.Settings._requestHeaderEncodingSelector;

 int headerListSize = headers.HeaderStore.Count * HeaderField.RfcOverhead;

 ref string[]? tmpHeaderValuesArray = ref t_headerValues;
 foreach (KeyValuePair<HeaderDescriptor, object> header in headers.HeaderStore)
 {
Expand All@@ -1360,6 +1381,10 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 // The Connection, Upgrade and ProxyConnection headers are also not supported in HTTP2.
 if (knownHeader != KnownHeaders.Host && knownHeader != KnownHeaders.Connection && knownHeader != KnownHeaders.Upgrade && knownHeader != KnownHeaders.ProxyConnection)
 {
 // The length of the encoded name may be shorter than the actual name.
 // Ensure that headerListSize is always >= of the actual size.
 headerListSize += knownHeader.Name.Length;

 if (header.Key.KnownHeader == KnownHeaders.TE)
 {
 // HTTP/2 allows only 'trailers' TE header. rfc7540 8.1.2.2
Expand DownExpand Up@@ -1400,6 +1425,8 @@ private void WriteHeaderCollection(HttpRequestMessage request, HttpHeaders heade
 WriteLiteralHeader(header.Key.Name, headerValues, valueEncoding, ref headerBuffer);
 }
 }

 return headerListSize;
 }

 private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuffer)
Expand DownExpand Up@@ -1430,9 +1457,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff

 WriteIndexedHeader(_stream is SslStream ? H2StaticTable.SchemeHttps : H2StaticTable.SchemeHttp, ref headerBuffer);

 if (request.HasHeaders && request.Headers.Host != null)
 if (request.HasHeaders && request.Headers.Host is string host)
 {
 WriteIndexedHeader(H2StaticTable.Authority, request.Headers.Host, ref headerBuffer);
 WriteIndexedHeader(H2StaticTable.Authority, host, ref headerBuffer);
 }
 else
 {
Expand All@@ -1450,9 +1477,11 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 WriteIndexedHeader(H2StaticTable.PathSlash, pathAndQuery, ref headerBuffer);
 }

 int headerListSize = 3 * HeaderField.RfcOverhead; // Method, Authority, Path

 if (request.HasHeaders)
 {
 WriteHeaderCollection(request, request.Headers, ref headerBuffer);
headerListSize += WriteHeaderCollection(request, request.Headers, ref headerBuffer);
 }

 // Determine cookies to send.
Expand All@@ -1462,9 +1491,9 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 if (cookiesFromContainer != string.Empty)
 {
 WriteBytes(KnownHeaders.Cookie.Http2EncodedName, ref headerBuffer);

 Encoding? cookieEncoding = _pool.Settings._requestHeaderEncodingSelector?.Invoke(KnownHeaders.Cookie.Name, request);
 WriteLiteralHeaderValue(cookiesFromContainer, cookieEncoding, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.Cookie.Length + HeaderField.RfcOverhead;
 }
 }

Expand All@@ -1476,11 +1505,24 @@ private void WriteHeaders(HttpRequestMessage request, ref ArrayBuffer headerBuff
 {
 WriteBytes(KnownHeaders.ContentLength.Http2EncodedName, ref headerBuffer);
 WriteLiteralHeaderValue("0", valueEncoding: null, ref headerBuffer);
 headerListSize += HttpKnownHeaderNames.ContentLength.Length + HeaderField.RfcOverhead;
 }
 }
 else
 {
 WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 headerListSize += WriteHeaderCollection(request, request.Content.Headers, ref headerBuffer);
 }

 // The headerListSize is an approximation of the total header length.
 // This is acceptable as long as the value is always >= the actual length.
 // We must avoid ever sending more than the server allowed.
 // This approach must be revisted if we ever support the dynamic table or compression when sending requests.
 headerListSize += headerBuffer.ActiveLength;

 uint maxHeaderListSize = _maxHeaderListSize;
 if ((uint)headerListSize > maxHeaderListSize)
 {
 throw new HttpRequestException(SR.Format(SR.net_http_request_headers_exceeded_length, maxHeaderListSize));
 }
 }

Expand DownExpand Up@@ -1553,10 +1595,10 @@ private async ValueTask<Http2Stream> SendHeadersAsync(HttpRequestMessage request
 // streams are created and started in order.
 await PerformWriteAsync(totalSize, (thisRef: this, http2Stream, headerBytes, endStream: (request.Content == null), mustFlush), static (s, writeBuffer) =>
 {
 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 s.thisRef.AddStream(s.http2Stream);

 if (NetEventSource.Log.IsEnabled()) s.thisRef.Trace(s.http2Stream.StreamId, $"Started writing. Total header bytes={s.headerBytes.Length}");

 Span<byte> span = writeBuffer.Span;

 // Copy the HEADERS frame.
Expand Down

8 changes: 8 additions & 0 deletions
src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnectionPool.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -96,6 +96,14 @@ internal sealed class HttpConnectionPool : IDisposable
 private SemaphoreSlim? _http3ConnectionCreateLock;
 internal readonly byte[]? _http3EncodedAuthorityHostHeader;

 // These settings are advertised by the server via SETTINGS_MAX_HEADER_LIST_SIZE.
 // If we had previous connections to the same host in this pool, memorize the last value seen.
 // This value is used as an initial value for new connections before they have a chance to observe the SETTINGS frame.
 // Doing so avoids immediately exceeding the server limit on the first request, potentially causing the connection to be torn down.
 // 0 means there were no previous connections, or they hadn't advertised this limit.
 // There is no need to lock when updating these values - we're only interested in saving _a_ value, not necessarily the min/max/last.
 internal uint _lastSeenHttp2MaxHeaderListSize;

 /// <summary>For non-proxy connection pools, this is the host name in bytes; for proxies, null.</summary>
 private readonly byte[]? _hostHeaderValueBytes;
 /// <summary>Options specialized and cached for this pool and its key.</summary>
Expand Down

101 changes: 101 additions & 0 deletions
src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs

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Original file line numberDiff line numberDiff line change
Expand Up@@ -1205,6 +1205,107 @@ public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLengt
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Test(ITestOutputHelper output) : base(output) { }
 }

 [ConditionalClass(typeof(SocketsHttpHandler), nameof(SocketsHttpHandler.IsSupported))]
 public sealed class SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2 : HttpClientHandlerTestBase
 {
 public SocketsHttpHandler_HttpClientHandler_MaxResponseHeadersLength_Http2(ITestOutputHelper output) : base(output) { }
 protected override Version UseVersion => HttpVersion.Version20;

 [Fact]
 public async Task ServerAdvertisedMaxHeaderListSize_IsHonoredByClient()
 {
 const int Limit = 10_000;

 using HttpClientHandler handler = CreateHttpClientHandler();
 using HttpClient client = CreateHttpClient(handler);

 // We want to test that the client remembered the setting it received from the previous connection.
 // To do this, we trick the client into using the same HttpConnectionPool for both server connections.
 Uri lastServerUri = null;

 GetUnderlyingSocketsHttpHandler(handler).ConnectCallback = async (context, ct) =>
 {
 Assert.Equal("foo", context.DnsEndPoint.Host);

 Socket socket = new Socket(SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
 try
 {
 await socket.ConnectAsync(lastServerUri.IdnHost, lastServerUri.Port);
 return new NetworkStream(socket, ownsSocket: true);
 }
 catch
 {
 socket.Dispose();
 throw;
 }
 };

 TaskCompletionSource waitingForLastRequest = new(TaskCreationOptions.RunContinuationsAsynchronously);

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 // Send a dummy request to ensure the SETTINGS frame has been received.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 for (int i = 0; i < Limit / 40; i++)
 {
 request.Headers.Add($"Foo-{i}", "");
 }

 ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 await waitingForLastRequest.Task.WaitAsync(TimeSpan.FromSeconds(10));

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 var setting = new SettingsEntry { SettingId = SettingId.MaxHeaderListSize, Value = Limit };

 using GenericLoopbackConnection connection = await ((Http2LoopbackServer)server).EstablishConnectionAsync(setting);

 await connection.ReadRequestDataAsync();
 await connection.SendResponseAsync(content: "Hello world");

 waitingForLastRequest.SetResult();

 // HandleRequestAsync will close the connection
 await connection.HandleRequestAsync(content: "Hello world");
 });

 await LoopbackServerFactory.CreateClientAndServerAsync(async uri =>
 {
 lastServerUri = uri;
 uri = new UriBuilder(uri) { Host = "foo", Port = 42 }.Uri;

 HttpRequestMessage request = CreateRequest(HttpMethod.Get, uri, UseVersion, exactVersion: true);
 request.Headers.Add("Foo", new string('a', Limit));

 Exception ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request));
 Assert.Contains(Limit.ToString(), ex.Message);

 // Ensure that the connection is still usable for requests that don't hit the limit.
 Assert.Equal("Hello world", await client.GetStringAsync(uri));
 },
 async server =>
 {
 await server.HandleRequestAsync(content: "Hello world");
 });
 }
 }

 [SkipOnPlatform(TestPlatforms.Browser, "Socket is not supported on Browser")]
 public sealed class SocketsHttpHandler_HttpClientHandler_Authentication_Test : HttpClientHandler_Authentication_Test
 {
Expand Down