aspnetcore/src/Kestrel.Core/Internal/Infrastructure/HttpUtilities.cs

554 lines
20 KiB
C#

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System;
using System.Diagnostics;
using System.Runtime.CompilerServices;
using System.Text;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http;
namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure
{
public static partial class HttpUtilities
{
public const string Http10Version = "HTTP/1.0";
public const string Http11Version = "HTTP/1.1";
public const string Http2Version = "HTTP/2";
public const string HttpUriScheme = "http://";
public const string HttpsUriScheme = "https://";
// readonly primitive statics can be Jit'd to consts https://github.com/dotnet/coreclr/issues/1079
private static readonly ulong _httpSchemeLong = GetAsciiStringAsLong(HttpUriScheme + "\0");
private static readonly ulong _httpsSchemeLong = GetAsciiStringAsLong(HttpsUriScheme);
private const uint _httpGetMethodInt = 542393671; // GetAsciiStringAsInt("GET "); const results in better codegen
private const ulong _http10VersionLong = 3471766442030158920; // GetAsciiStringAsLong("HTTP/1.0"); const results in better codegen
private const ulong _http11VersionLong = 3543824036068086856; // GetAsciiStringAsLong("HTTP/1.1"); const results in better codegen
private static readonly UTF8EncodingSealed HeaderValueEncoding = new UTF8EncodingSealed();
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static void SetKnownMethod(ulong mask, ulong knownMethodUlong, HttpMethod knownMethod, int length)
{
_knownMethods[GetKnownMethodIndex(knownMethodUlong)] = new Tuple<ulong, ulong, HttpMethod, int>(mask, knownMethodUlong, knownMethod, length);
}
private static void FillKnownMethodsGaps()
{
var knownMethods = _knownMethods;
var length = knownMethods.Length;
var invalidHttpMethod = new Tuple<ulong, ulong, HttpMethod, int>(_mask8Chars, 0ul, HttpMethod.Custom, 0);
for (int i = 0; i < length; i++)
{
if (knownMethods[i] == null)
{
knownMethods[i] = invalidHttpMethod;
}
}
}
private static unsafe ulong GetAsciiStringAsLong(string str)
{
Debug.Assert(str.Length == 8, "String must be exactly 8 (ASCII) characters long.");
var bytes = Encoding.ASCII.GetBytes(str);
fixed (byte* ptr = &bytes[0])
{
return *(ulong*)ptr;
}
}
private static unsafe uint GetAsciiStringAsInt(string str)
{
Debug.Assert(str.Length == 4, "String must be exactly 4 (ASCII) characters long.");
var bytes = Encoding.ASCII.GetBytes(str);
fixed (byte* ptr = &bytes[0])
{
return *(uint*)ptr;
}
}
private static unsafe ulong GetMaskAsLong(byte[] bytes)
{
Debug.Assert(bytes.Length == 8, "Mask must be exactly 8 bytes long.");
fixed (byte* ptr = bytes)
{
return *(ulong*)ptr;
}
}
public static unsafe string GetAsciiStringNonNullCharacters(this Span<byte> span)
{
if (span.IsEmpty)
{
return string.Empty;
}
var asciiString = new string('\0', span.Length);
fixed (char* output = asciiString)
fixed (byte* buffer = span)
{
// This version if AsciiUtilities returns null if there are any null (0 byte) characters
// in the string
if (!StringUtilities.TryGetAsciiString(buffer, output, span.Length))
{
throw new InvalidOperationException();
}
}
return asciiString;
}
public static unsafe string GetAsciiOrUTF8StringNonNullCharacters(this Span<byte> span)
{
if (span.IsEmpty)
{
return string.Empty;
}
var resultString = new string('\0', span.Length);
fixed (char* output = resultString)
fixed (byte* buffer = span)
{
// This version if AsciiUtilities returns null if there are any null (0 byte) characters
// in the string
if (!StringUtilities.TryGetAsciiString(buffer, output, span.Length))
{
// null characters are considered invalid
if (span.IndexOf((byte)0) != -1)
{
throw new InvalidOperationException();
}
try
{
resultString = HeaderValueEncoding.GetString(buffer, span.Length);
}
catch (DecoderFallbackException)
{
throw new InvalidOperationException();
}
}
}
return resultString;
}
public static string GetAsciiStringEscaped(this Span<byte> span, int maxChars)
{
var sb = new StringBuilder();
for (var i = 0; i < Math.Min(span.Length, maxChars); i++)
{
var ch = span[i];
sb.Append(ch < 0x20 || ch >= 0x7F ? $"\\x{ch:X2}" : ((char)ch).ToString());
}
if (span.Length > maxChars)
{
sb.Append("...");
}
return sb.ToString();
}
/// <summary>
/// Checks that up to 8 bytes from <paramref name="span"/> correspond to a known HTTP method.
/// </summary>
/// <remarks>
/// A "known HTTP method" can be an HTTP method name defined in the HTTP/1.1 RFC.
/// Since all of those fit in at most 8 bytes, they can be optimally looked up by reading those bytes as a long. Once
/// in that format, it can be checked against the known method.
/// The Known Methods (CONNECT, DELETE, GET, HEAD, PATCH, POST, PUT, OPTIONS, TRACE) are all less than 8 bytes
/// and will be compared with the required space. A mask is used if the Known method is less than 8 bytes.
/// To optimize performance the GET method will be checked first.
/// </remarks>
/// <returns><c>true</c> if the input matches a known string, <c>false</c> otherwise.</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static unsafe bool GetKnownMethod(this Span<byte> span, out HttpMethod method, out int length)
{
fixed (byte* data = span)
{
method = GetKnownMethod(data, span.Length, out length);
return method != HttpMethod.Custom;
}
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
internal static unsafe HttpMethod GetKnownMethod(byte* data, int length, out int methodLength)
{
methodLength = 0;
if (length < sizeof(uint))
{
return HttpMethod.Custom;
}
else if (*(uint*)data == _httpGetMethodInt)
{
methodLength = 3;
return HttpMethod.Get;
}
else if (length < sizeof(ulong))
{
return HttpMethod.Custom;
}
else
{
var value = *(ulong*)data;
var key = GetKnownMethodIndex(value);
var x = _knownMethods[key];
if (x != null && (value & x.Item1) == x.Item2)
{
methodLength = x.Item4;
return x.Item3;
}
}
return HttpMethod.Custom;
}
/// <summary>
/// Parses string <paramref name="value"/> for a known HTTP method.
/// </summary>
/// <remarks>
/// A "known HTTP method" can be an HTTP method name defined in the HTTP/1.1 RFC.
/// The Known Methods (CONNECT, DELETE, GET, HEAD, PATCH, POST, PUT, OPTIONS, TRACE)
/// </remarks>
/// <returns><see cref="HttpMethod"/></returns>
public static HttpMethod GetKnownMethod(string value)
{
// Called by http/2
if (value == null)
{
return HttpMethod.None;
}
var length = value.Length;
if (length == 0)
{
return HttpMethod.None;
}
// Start with custom and assign if known method is found
var method = HttpMethod.Custom;
var firstChar = value[0];
if (length == 3)
{
if (firstChar == 'G' && string.Equals(value, HttpMethods.Get, StringComparison.Ordinal))
{
method = HttpMethod.Get;
}
else if (firstChar == 'P' && string.Equals(value, HttpMethods.Put, StringComparison.Ordinal))
{
method = HttpMethod.Put;
}
}
else if (length == 4)
{
if (firstChar == 'H' && string.Equals(value, HttpMethods.Head, StringComparison.Ordinal))
{
method = HttpMethod.Head;
}
else if(firstChar == 'P' && string.Equals(value, HttpMethods.Post, StringComparison.Ordinal))
{
method = HttpMethod.Post;
}
}
else if (length == 5)
{
if (firstChar == 'T' && string.Equals(value, HttpMethods.Trace, StringComparison.Ordinal))
{
method = HttpMethod.Trace;
}
else if(firstChar == 'P' && string.Equals(value, HttpMethods.Patch, StringComparison.Ordinal))
{
method = HttpMethod.Patch;
}
}
else if (length == 6)
{
if (firstChar == 'D' && string.Equals(value, HttpMethods.Delete, StringComparison.Ordinal))
{
method = HttpMethod.Delete;
}
}
else if (length == 7)
{
if (firstChar == 'C' && string.Equals(value, HttpMethods.Connect, StringComparison.Ordinal))
{
method = HttpMethod.Connect;
}
else if (firstChar == 'O' && string.Equals(value, HttpMethods.Options, StringComparison.Ordinal))
{
method = HttpMethod.Options;
}
}
return method;
}
/// <summary>
/// Checks 9 bytes from <paramref name="span"/> correspond to a known HTTP version.
/// </summary>
/// <remarks>
/// A "known HTTP version" Is is either HTTP/1.0 or HTTP/1.1.
/// Since those fit in 8 bytes, they can be optimally looked up by reading those bytes as a long. Once
/// in that format, it can be checked against the known versions.
/// The Known versions will be checked with the required '\r'.
/// To optimize performance the HTTP/1.1 will be checked first.
/// </remarks>
/// <returns><c>true</c> if the input matches a known string, <c>false</c> otherwise.</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static unsafe bool GetKnownVersion(this Span<byte> span, out HttpVersion knownVersion, out byte length)
{
fixed (byte* data = span)
{
knownVersion = GetKnownVersion(data, span.Length);
if (knownVersion != HttpVersion.Unknown)
{
length = sizeof(ulong);
return true;
}
length = 0;
return false;
}
}
/// <summary>
/// Checks 9 bytes from <paramref name="location"/> correspond to a known HTTP version.
/// </summary>
/// <remarks>
/// A "known HTTP version" Is is either HTTP/1.0 or HTTP/1.1.
/// Since those fit in 8 bytes, they can be optimally looked up by reading those bytes as a long. Once
/// in that format, it can be checked against the known versions.
/// The Known versions will be checked with the required '\r'.
/// To optimize performance the HTTP/1.1 will be checked first.
/// </remarks>
/// <returns><c>true</c> if the input matches a known string, <c>false</c> otherwise.</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
internal static unsafe HttpVersion GetKnownVersion(byte* location, int length)
{
HttpVersion knownVersion;
var version = *(ulong*)location;
if (length < sizeof(ulong) + 1 || location[sizeof(ulong)] != (byte)'\r')
{
knownVersion = HttpVersion.Unknown;
}
else if (version == _http11VersionLong)
{
knownVersion = HttpVersion.Http11;
}
else if (version == _http10VersionLong)
{
knownVersion = HttpVersion.Http10;
}
else
{
knownVersion = HttpVersion.Unknown;
}
return knownVersion;
}
/// <summary>
/// Checks 8 bytes from <paramref name="span"/> that correspond to 'http://' or 'https://'
/// </summary>
/// <param name="span">The span</param>
/// <param name="knownScheme">A reference to the known scheme, if the input matches any</param>
/// <returns>True when memory starts with known http or https schema</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static unsafe bool GetKnownHttpScheme(this Span<byte> span, out HttpScheme knownScheme)
{
fixed (byte* data = span)
{
return GetKnownHttpScheme(data, span.Length, out knownScheme);
}
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static unsafe bool GetKnownHttpScheme(byte* location, int length, out HttpScheme knownScheme)
{
if (length >= sizeof(ulong))
{
var scheme = *(ulong*)location;
if ((scheme & _mask7Chars) == _httpSchemeLong)
{
knownScheme = HttpScheme.Http;
return true;
}
if (scheme == _httpsSchemeLong)
{
knownScheme = HttpScheme.Https;
return true;
}
}
knownScheme = HttpScheme.Unknown;
return false;
}
public static string VersionToString(HttpVersion httpVersion)
{
switch (httpVersion)
{
case HttpVersion.Http10:
return Http10Version;
case HttpVersion.Http11:
return Http11Version;
default:
return null;
}
}
public static string MethodToString(HttpMethod method)
{
int methodIndex = (int)method;
if (methodIndex >= 0 && methodIndex <= 8)
{
return _methodNames[methodIndex];
}
return null;
}
public static string SchemeToString(HttpScheme scheme)
{
switch (scheme)
{
case HttpScheme.Http:
return HttpUriScheme;
case HttpScheme.Https:
return HttpsUriScheme;
default:
return null;
}
}
public static bool IsHostHeaderValid(string hostText)
{
if (string.IsNullOrEmpty(hostText))
{
// The spec allows empty values
return true;
}
var firstChar = hostText[0];
if (firstChar == '[')
{
// Tail call
return IsIPv6HostValid(hostText);
}
else
{
if (firstChar == ':')
{
// Only a port
return false;
}
var invalid = HttpCharacters.IndexOfInvalidHostChar(hostText);
if (invalid >= 0)
{
// Tail call
return IsHostPortValid(hostText, invalid);
}
return true;
}
}
// The lead '[' was already checked
private static bool IsIPv6HostValid(string hostText)
{
for (var i = 1; i < hostText.Length; i++)
{
var ch = hostText[i];
if (ch == ']')
{
// [::1] is the shortest valid IPv6 host
if (i < 4)
{
return false;
}
else if (i + 1 < hostText.Length)
{
// Tail call
return IsHostPortValid(hostText, i + 1);
}
return true;
}
if (!IsHex(ch) && ch != ':' && ch != '.')
{
return false;
}
}
// Must contain a ']'
return false;
}
private static bool IsHostPortValid(string hostText, int offset)
{
var firstChar = hostText[offset];
offset++;
if (firstChar != ':' || offset == hostText.Length)
{
// Must have at least one number after the colon if present.
return false;
}
for (var i = offset; i < hostText.Length; i++)
{
if (!IsNumeric(hostText[i]))
{
return false;
}
}
return true;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static bool IsNumeric(char ch)
{
// '0' <= ch && ch <= '9'
// (uint)(ch - '0') <= (uint)('9' - '0')
// Subtract start of range '0'
// Cast to uint to change negative numbers to large numbers
// Check if less than 10 representing chars '0' - '9'
return (uint)(ch - '0') < 10u;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static bool IsHex(char ch)
{
return IsNumeric(ch)
// || ('a' <= ch && ch <= 'f')
// || ('A' <= ch && ch <= 'F');
// Lowercase indiscriminately (or with 32)
// Subtract start of range 'a'
// Cast to uint to change negative numbers to large numbers
// Check if less than 6 representing chars 'a' - 'f'
|| (uint)((ch | 32) - 'a') < 6u;
}
// Allow for de-virtualization (see https://github.com/dotnet/coreclr/pull/9230)
private sealed class UTF8EncodingSealed : UTF8Encoding
{
public UTF8EncodingSealed() : base(encoderShouldEmitUTF8Identifier: false, throwOnInvalidBytes: true) { }
public override byte[] GetPreamble() => Array.Empty<byte>();
}
}
}