restructured zenhttp (#472)

separating the http server implementations into a directory and moved diagsvcs into zenserver since it's somewhat hard-coded for it

1 files changed, 370 insertions, 0 deletions

diff --git a/src/zenhttp/servers/httpparser.cpp b/src/zenhttp/servers/httpparser.cpp
new file mode 100644
index 000000000..6b987151a
--- /dev/null
+++ b/src/zenhttp/servers/httpparser.cpp
@@ -0,0 +1,370 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#include "httpparser.h"
+
+#include <zencore/logging.h>
+#include <zencore/string.h>
+
+namespace zen {
+
+using namespace std::literals;
+
+static constinit uint32_t HashContentLength = HashStringAsLowerDjb2("Content-Length"sv);
+static constinit uint32_t HashContentType	= HashStringAsLowerDjb2("Content-Type"sv);
+static constinit uint32_t HashAccept		= HashStringAsLowerDjb2("Accept"sv);
+static constinit uint32_t HashExpect		= HashStringAsLowerDjb2("Expect"sv);
+static constinit uint32_t HashSession		= HashStringAsLowerDjb2("UE-Session"sv);
+static constinit uint32_t HashRequest		= HashStringAsLowerDjb2("UE-Request"sv);
+static constinit uint32_t HashRange			= HashStringAsLowerDjb2("Range"sv);
+
+//////////////////////////////////////////////////////////////////////////
+//
+// HttpRequestParser
+//
+
+http_parser_settings HttpRequestParser::s_ParserSettings{
+	.on_message_begin = [](http_parser* p) { return GetThis(p)->OnMessageBegin(); },
+	.on_url			  = [](http_parser* p, const char* Data, size_t ByteCount) { return GetThis(p)->OnUrl(Data, ByteCount); },
+	.on_status =
+		[](http_parser* p, const char* Data, size_t ByteCount) {
+			ZEN_UNUSED(p, Data, ByteCount);
+			return 0;
+		},
+	.on_header_field	 = [](http_parser* p, const char* Data, size_t ByteCount) { return GetThis(p)->OnHeader(Data, ByteCount); },
+	.on_header_value	 = [](http_parser* p, const char* Data, size_t ByteCount) { return GetThis(p)->OnHeaderValue(Data, ByteCount); },
+	.on_headers_complete = [](http_parser* p) { return GetThis(p)->OnHeadersComplete(); },
+	.on_body			 = [](http_parser* p, const char* Data, size_t ByteCount) { return GetThis(p)->OnBody(Data, ByteCount); },
+	.on_message_complete = [](http_parser* p) { return GetThis(p)->OnMessageComplete(); },
+	.on_chunk_header{},
+	.on_chunk_complete{}};
+
+HttpRequestParser::HttpRequestParser(HttpRequestParserCallbacks& Connection) : m_Connection(Connection)
+{
+	http_parser_init(&m_Parser, HTTP_REQUEST);
+	m_Parser.data = this;
+
+	ResetState();
+}
+
+HttpRequestParser::~HttpRequestParser()
+{
+}
+
+size_t
+HttpRequestParser::ConsumeData(const char* InputData, size_t DataSize)
+{
+	const size_t ConsumedBytes = http_parser_execute(&m_Parser, &s_ParserSettings, InputData, DataSize);
+
+	http_errno HttpErrno = HTTP_PARSER_ERRNO((&m_Parser));
+
+	if (HttpErrno && HttpErrno != HPE_INVALID_EOF_STATE)
+	{
+		ZEN_WARN("HTTP parser error {} ('{}'). Closing connection", http_errno_name(HttpErrno), http_errno_description(HttpErrno));
+		return ~0ull;
+	}
+
+	return ConsumedBytes;
+}
+
+int
+HttpRequestParser::OnUrl(const char* Data, size_t Bytes)
+{
+	if (!m_Url)
+	{
+		ZEN_ASSERT_SLOW(m_UrlLength == 0);
+		m_Url = m_HeaderCursor;
+	}
+
+	const size_t RemainingBufferSpace = sizeof m_HeaderBuffer + m_HeaderBuffer - m_HeaderCursor;
+
+	if (RemainingBufferSpace < Bytes)
+	{
+		ZEN_WARN("HTTP parser does not have enough space for incoming request, need {} more bytes", Bytes - RemainingBufferSpace);
+		return 1;
+	}
+
+	memcpy(m_HeaderCursor, Data, Bytes);
+	m_HeaderCursor += Bytes;
+	m_UrlLength += Bytes;
+
+	return 0;
+}
+
+int
+HttpRequestParser::OnHeader(const char* Data, size_t Bytes)
+{
+	if (m_CurrentHeaderValueLength)
+	{
+		AppendCurrentHeader();
+
+		m_CurrentHeaderNameLength  = 0;
+		m_CurrentHeaderValueLength = 0;
+		m_CurrentHeaderName		   = m_HeaderCursor;
+	}
+	else if (m_CurrentHeaderName == nullptr)
+	{
+		m_CurrentHeaderName = m_HeaderCursor;
+	}
+
+	const size_t RemainingBufferSpace = sizeof m_HeaderBuffer + m_HeaderBuffer - m_HeaderCursor;
+	if (RemainingBufferSpace < Bytes)
+	{
+		ZEN_WARN("HTTP parser does not have enough space for incoming header name, need {} more bytes", Bytes - RemainingBufferSpace);
+		return 1;
+	}
+
+	memcpy(m_HeaderCursor, Data, Bytes);
+	m_HeaderCursor += Bytes;
+	m_CurrentHeaderNameLength += Bytes;
+
+	return 0;
+}
+
+void
+HttpRequestParser::AppendCurrentHeader()
+{
+	std::string_view HeaderName(m_CurrentHeaderName, m_CurrentHeaderNameLength);
+	std::string_view HeaderValue(m_CurrentHeaderValue, m_CurrentHeaderValueLength);
+
+	const uint32_t HeaderHash = HashStringAsLowerDjb2(HeaderName);
+
+	if (HeaderHash == HashContentLength)
+	{
+		m_ContentLengthHeaderIndex = (int8_t)m_Headers.size();
+	}
+	else if (HeaderHash == HashAccept)
+	{
+		m_AcceptHeaderIndex = (int8_t)m_Headers.size();
+	}
+	else if (HeaderHash == HashContentType)
+	{
+		m_ContentTypeHeaderIndex = (int8_t)m_Headers.size();
+	}
+	else if (HeaderHash == HashSession)
+	{
+		m_SessionId = Oid::FromHexString(HeaderValue);
+	}
+	else if (HeaderHash == HashRequest)
+	{
+		std::from_chars(HeaderValue.data(), HeaderValue.data() + HeaderValue.size(), m_RequestId);
+	}
+	else if (HeaderHash == HashExpect)
+	{
+		if (HeaderValue == "100-continue"sv)
+		{
+			// We don't currently do anything with this
+			m_Expect100Continue = true;
+		}
+		else
+		{
+			ZEN_INFO("Unexpected expect - Expect: {}", HeaderValue);
+		}
+	}
+	else if (HeaderHash == HashRange)
+	{
+		m_RangeHeaderIndex = (int8_t)m_Headers.size();
+	}
+
+	m_Headers.emplace_back(HeaderName, HeaderValue);
+}
+
+int
+HttpRequestParser::OnHeaderValue(const char* Data, size_t Bytes)
+{
+	if (m_CurrentHeaderValueLength == 0)
+	{
+		m_CurrentHeaderValue = m_HeaderCursor;
+	}
+
+	const size_t RemainingBufferSpace = sizeof m_HeaderBuffer + m_HeaderBuffer - m_HeaderCursor;
+	if (RemainingBufferSpace < Bytes)
+	{
+		ZEN_WARN("HTTP parser does not have enough space for incoming header value, need {} more bytes", Bytes - RemainingBufferSpace);
+		return 1;
+	}
+
+	memcpy(m_HeaderCursor, Data, Bytes);
+	m_HeaderCursor += Bytes;
+	m_CurrentHeaderValueLength += Bytes;
+
+	return 0;
+}
+
+static void
+NormalizeUrlPath(const char* Url, size_t UrlLength, std::string& NormalizedUrl)
+{
+	bool LastCharWasSeparator = false;
+	for (std::string_view::size_type UrlIndex = 0; UrlIndex < UrlLength; ++UrlIndex)
+	{
+		const char UrlChar	   = Url[UrlIndex];
+		const bool IsSeparator = (UrlChar == '/');
+
+		if (IsSeparator && LastCharWasSeparator)
+		{
+			if (NormalizedUrl.empty())
+			{
+				NormalizedUrl.reserve(UrlLength);
+				NormalizedUrl.append(Url, UrlIndex);
+			}
+
+			if (!LastCharWasSeparator)
+			{
+				NormalizedUrl.push_back('/');
+			}
+		}
+		else if (!NormalizedUrl.empty())
+		{
+			NormalizedUrl.push_back(UrlChar);
+		}
+
+		LastCharWasSeparator = IsSeparator;
+	}
+}
+
+int
+HttpRequestParser::OnHeadersComplete()
+{
+	try
+	{
+		if (m_CurrentHeaderValueLength)
+		{
+			AppendCurrentHeader();
+		}
+
+		m_KeepAlive = !!http_should_keep_alive(&m_Parser);
+
+		switch (m_Parser.method)
+		{
+			case HTTP_GET:
+				m_RequestVerb = HttpVerb::kGet;
+				break;
+
+			case HTTP_POST:
+				m_RequestVerb = HttpVerb::kPost;
+				break;
+
+			case HTTP_PUT:
+				m_RequestVerb = HttpVerb::kPut;
+				break;
+
+			case HTTP_DELETE:
+				m_RequestVerb = HttpVerb::kDelete;
+				break;
+
+			case HTTP_HEAD:
+				m_RequestVerb = HttpVerb::kHead;
+				break;
+
+			case HTTP_COPY:
+				m_RequestVerb = HttpVerb::kCopy;
+				break;
+
+			case HTTP_OPTIONS:
+				m_RequestVerb = HttpVerb::kOptions;
+				break;
+
+			default:
+				ZEN_WARN("invalid HTTP method: '{}'", http_method_str((http_method)m_Parser.method));
+				break;
+		}
+
+		std::string_view Url(m_Url, m_UrlLength);
+
+		if (auto QuerySplit = Url.find_first_of('?'); QuerySplit != std::string_view::npos)
+		{
+			m_UrlLength	  = QuerySplit;
+			m_QueryString = m_Url + QuerySplit + 1;
+			m_QueryLength = Url.size() - QuerySplit - 1;
+		}
+
+		NormalizeUrlPath(m_Url, m_UrlLength, m_NormalizedUrl);
+
+		if (m_ContentLengthHeaderIndex >= 0)
+		{
+			std::string_view& Value			= m_Headers[m_ContentLengthHeaderIndex].Value;
+			uint64_t		  ContentLength = 0;
+			std::from_chars(Value.data(), Value.data() + Value.size(), ContentLength);
+
+			if (ContentLength)
+			{
+				m_BodyBuffer = IoBuffer(ContentLength);
+			}
+
+			m_BodyBuffer.SetContentType(ContentType());
+
+			m_BodyPosition = 0;
+		}
+	}
+	catch (const std::exception& Ex)
+	{
+		ZEN_WARN("HttpRequestParser::OnHeadersComplete failed. Reason '{}'", Ex.what());
+		return -1;
+	}
+	return 0;
+}
+
+int
+HttpRequestParser::OnBody(const char* Data, size_t Bytes)
+{
+	if (m_BodyPosition + Bytes > m_BodyBuffer.Size())
+	{
+		ZEN_WARN("HTTP parser incoming body is larger than content size, need {} more bytes",
+				 (m_BodyPosition + Bytes) - m_BodyBuffer.Size());
+		return 1;
+	}
+	memcpy(reinterpret_cast<uint8_t*>(m_BodyBuffer.MutableData()) + m_BodyPosition, Data, Bytes);
+	m_BodyPosition += Bytes;
+
+	if (http_body_is_final(&m_Parser))
+	{
+		if (m_BodyPosition != m_BodyBuffer.Size())
+		{
+			ZEN_WARN("Body mismatch! {} != {}", m_BodyPosition, m_BodyBuffer.Size());
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+void
+HttpRequestParser::ResetState()
+{
+	m_HeaderCursor			   = m_HeaderBuffer;
+	m_CurrentHeaderName		   = nullptr;
+	m_CurrentHeaderNameLength  = 0;
+	m_CurrentHeaderValue	   = nullptr;
+	m_CurrentHeaderValueLength = 0;
+	m_CurrentHeaderName		   = nullptr;
+	m_Url					   = nullptr;
+	m_UrlLength				   = 0;
+	m_QueryString			   = nullptr;
+	m_QueryLength			   = 0;
+	m_ContentLengthHeaderIndex = -1;
+	m_AcceptHeaderIndex		   = -1;
+	m_ContentTypeHeaderIndex   = -1;
+	m_RangeHeaderIndex		   = -1;
+	m_Expect100Continue		   = false;
+	m_BodyBuffer			   = {};
+	m_BodyPosition			   = 0;
+	m_Headers.clear();
+	m_NormalizedUrl.clear();
+}
+
+int
+HttpRequestParser::OnMessageBegin()
+{
+	return 0;
+}
+
+int
+HttpRequestParser::OnMessageComplete()
+{
+	m_Connection.HandleRequest();
+
+	ResetState();
+
+	return 0;
+}
+
+}  // namespace zen