Reuse qtbase's HTTP header parser to avoid a reinvented wheel

Fixes: QTBUG-80700
Change-Id: I7b713fd869ac802d5eee8ebb8d90a2115365b509
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

4 files changed, 68 insertions, 103 deletions

diff --git a/src/websockets/qwebsocket_p.cpp b/src/websockets/qwebsocket_p.cpp
index 94ea60e..62d53c5 100644
--- a/src/websockets/qwebsocket_p.cpp
+++ b/src/websockets/qwebsocket_p.cpp
@@ -334,7 +334,7 @@ QWebSocket *QWebSocketPrivate::upgradeFrom(QTcpSocket *pTcpSocket,
         QNetworkRequest netRequest(request.requestUrl());
         const auto headers = request.headers();
         for (auto it = headers.begin(), end = headers.end(); it != end; ++it)
-            netRequest.setRawHeader(it.key().toLatin1(), it.value().toLatin1());
+            netRequest.setRawHeader(it->first, it->second);
 #ifndef QT_NO_SSL
         if (QSslSocket *sslSock = qobject_cast<QSslSocket *>(pTcpSocket))
             pWebSocket->setSslConfiguration(sslSock->sslConfiguration());
diff --git a/src/websockets/qwebsockethandshakerequest.cpp b/src/websockets/qwebsockethandshakerequest.cpp
index a40242d..0b1f8ae 100644
--- a/src/websockets/qwebsockethandshakerequest.cpp
+++ b/src/websockets/qwebsockethandshakerequest.cpp
@@ -59,7 +59,7 @@ QWebSocketHandshakeRequest::QWebSocketHandshakeRequest(int port, bool isSecure)
     m_port(port),
     m_isSecure(isSecure),
     m_isValid(false),
-    m_headers(),
+    m_parser(),
     m_versions(),
     m_key(),
     m_origin(),
@@ -83,7 +83,7 @@ QWebSocketHandshakeRequest::~QWebSocketHandshakeRequest()
 void QWebSocketHandshakeRequest::clear()
 {
     m_isValid = false;
-    m_headers.clear();
+    m_parser.clear();
     m_versions.clear();
     m_key.clear();
     m_origin.clear();
@@ -119,9 +119,17 @@ bool QWebSocketHandshakeRequest::isValid() const
 /*!
     \internal
  */
-QMultiMap<QString, QString> QWebSocketHandshakeRequest::headers() const
+QList<QPair<QByteArray, QByteArray>> QWebSocketHandshakeRequest::headers() const
 {
-    return m_headers;
+    return m_parser.headers();
+}
+
+/*!
+    \internal
+ */
+bool QWebSocketHandshakeRequest::hasHeader(const QByteArray &name) const
+{
+    return !m_parser.firstHeaderField(name).isEmpty();
 }
 
 /*!
@@ -189,43 +197,43 @@ QUrl QWebSocketHandshakeRequest::requestUrl() const
 }
 
 /*!
-    Reads a line of text from the given textstream (terminated by CR/LF).
+    Reads a line of text from the given QByteArrayView (terminated by CR/LF),
+    and removes the read bytes from the QByteArrayView.
     If an empty line was detected, an empty string is returned.
     When an error occurs, a null string is returned.
     \internal
  */
-static QString readLine(QTextStream &stream, int maxHeaderLineLength)
+static QByteArrayView readLine(QByteArrayView &header, int maxHeaderLineLength)
 {
-    QString line;
-    char c;
-    while (!stream.atEnd()) {
-        stream >> c;
-        if (stream.status() != QTextStream::Ok)
-            return QString();
-        if (c == char('\r')) {
-            //eat the \n character
-            stream >> c;
-            line.append(QStringLiteral(""));
-            break;
-        } else {
-            line.append(QChar::fromLatin1(c));
-            if (line.length() > maxHeaderLineLength)
-                return QString();
-        }
+    qsizetype length = qMin(maxHeaderLineLength, header.size());
+    QByteArrayView line = header.first(length);
+    qsizetype end = line.indexOf('\n');
+    if (end != -1) {
+        line = line.first(end);
+        if (line.endsWith('\r'))
+            line.chop(1);
+        header = header.sliced(end + 1);
+        return line;
     }
-    return line;
+    return QByteArrayView();
 }
 
 /*!
     \internal
  */
-void QWebSocketHandshakeRequest::readHandshake(QTextStream &textStream, int maxHeaderLineLength,
-                                               int maxHeaders)
+static void appendCommmaSeparatedLineToList(QStringList &list, QByteArrayView line)
+{
+    for (auto &c : QLatin1String(line).tokenize(QLatin1String(","), Qt::SkipEmptyParts))
+        list << c.trimmed().toString();
+}
+
+/*!
+    \internal
+ */
+void QWebSocketHandshakeRequest::readHandshake(QByteArrayView header, int maxHeaderLineLength)
 {
     clear();
-    if (Q_UNLIKELY(textStream.status() != QTextStream::Ok))
-        return;
-    const QString requestLine = readLine(textStream, maxHeaderLineLength);
+    QString requestLine = QString::fromLatin1(readLine(header, maxHeaderLineLength));
     if (requestLine.isNull()) {
         clear();
         return;
@@ -245,45 +253,15 @@ void QWebSocketHandshakeRequest::readHandshake(QTextStream &textStream, int maxH
         clear();
         return;
     }
-    QString headerLine = readLine(textStream, maxHeaderLineLength);
-    if (headerLine.isNull()) {
+
+    bool parsed = m_parser.parseHeaders(header);
+    if (!parsed) {
         clear();
         return;
     }
-    m_headers.clear();
-    // TODO: this should really use the existing code from QHttpNetworkReplyPrivate::parseHeader
-    auto lastHeader = m_headers.end();
-    while (!headerLine.isEmpty()) {
-        if (headerLine.startsWith(QLatin1Char(' ')) || headerLine.startsWith(QLatin1Char('\t'))) {
-            // continuation line -- add this to the last header field
-            if (Q_UNLIKELY(lastHeader == m_headers.end())) {
-                clear();
-                return;
-            }
-            lastHeader.value().append(QLatin1Char(' '));
-            lastHeader.value().append(headerLine.trimmed());
-        } else {
-            int colonPos = headerLine.indexOf(QLatin1Char(':'));
-            if (Q_UNLIKELY(colonPos <= 0)) {
-               clear();
-               return;
-            }
-            lastHeader = m_headers.insert(headerLine.left(colonPos).trimmed().toLower(),
-                                          headerLine.mid(colonPos + 1).trimmed());
-        }
-        if (m_headers.size() > maxHeaders) {
-            clear();
-            return;
-        }
-        headerLine = readLine(textStream, maxHeaderLineLength);
-        if (headerLine.isNull()) {
-            clear();
-            return;
-        }
-    }
 
     m_requestUrl = QUrl::fromEncoded(resourceName.toLatin1());
-    QString host = m_headers.value(QStringLiteral("host"), QString());
+    QString host = QString::fromLatin1(m_parser.firstHeaderField("host"));
     if (m_requestUrl.isRelative()) {
         // see https://tools.ietf.org/html/rfc6455#page-17
         // No. 4 item in "The requirements for this handshake"
@@ -299,59 +277,45 @@ void QWebSocketHandshakeRequest::readHandshake(QTextStream &textStream, int maxH
         m_requestUrl.setScheme(scheme);
     }
 
-    const QStringList versionLines = m_headers.values(QStringLiteral("sec-websocket-version"));
-    for (QStringList::const_iterator v = versionLines.begin(); v != versionLines.end(); ++v) {
-        const QStringList versions = (*v).split(QStringLiteral(","), Qt::SkipEmptyParts);
-        for (QStringList::const_iterator i = versions.begin(); i != versions.end(); ++i) {
+    const QList<QByteArray> versionLines = m_parser.headerFieldValues("sec-websocket-version");
+    for (auto v = versionLines.begin(); v != versionLines.end(); ++v) {
+        for (const auto &version :
+             QString::fromLatin1(*v).tokenize(QStringLiteral(","), Qt::SkipEmptyParts)) {
             bool ok = false;
-            (void)(*i).toUInt(&ok);
+            (void)version.toUInt(&ok);
             if (!ok) {
                 clear();
                 return;
             }
             const QWebSocketProtocol::Version ver =
-                    QWebSocketProtocol::versionFromString((*i).trimmed());
+                    QWebSocketProtocol::versionFromString(version.trimmed().toString());
             m_versions << ver;
         }
     }
     //sort in descending order
     std::sort(m_versions.begin(), m_versions.end(), std::greater<QWebSocketProtocol::Version>());
-    m_key = m_headers.value(QStringLiteral("sec-websocket-key"), QString());
-    //must contain "Upgrade", case-insensitive
-    const QString upgrade = m_headers.value(QStringLiteral("upgrade"), QString());
-    //must be equal to "websocket", case-insensitive
-    const QString connection = m_headers.value(QStringLiteral("connection"), QString());
-    const QStringList connectionLine = connection.split(QStringLiteral(","), Qt::SkipEmptyParts);
+
+    m_key = QString::fromLatin1(m_parser.firstHeaderField("sec-websocket-key"));
+    const QByteArray upgrade = m_parser.firstHeaderField("upgrade");
     QStringList connectionValues;
-    for (QStringList::const_iterator c = connectionLine.begin(); c != connectionLine.end(); ++c)
-        connectionValues << (*c).trimmed();
+    appendCommmaSeparatedLineToList(connectionValues, m_parser.firstHeaderField("connection"));
 
     //optional headers
-    m_origin = m_headers.value(QStringLiteral("origin"), QString());
-    const QStringList protocolLines = m_headers.values(QStringLiteral("sec-websocket-protocol"));
-    for (const QString& pl : protocolLines) {
-        const QStringList protocols = pl.split(QStringLiteral(","), Qt::SkipEmptyParts);
-        for (const QString& p : protocols)
-            m_protocols << p.trimmed();
-    }
+    m_origin = QString::fromLatin1(m_parser.firstHeaderField("origin"));
+    const QList<QByteArray> protocolLines = m_parser.headerFieldValues("sec-websocket-protocol");
+    for (const QByteArray &pl : protocolLines)
+        appendCommmaSeparatedLineToList(m_protocols, pl);
 
-    const QStringList extensionLines = m_headers.values(QStringLiteral("sec-websocket-extensions"));
-    for (const QString& el : extensionLines) {
-        const QStringList extensions = el.split(QStringLiteral(","), Qt::SkipEmptyParts);
-        for (const QString& e : extensions)
-            m_extensions << e.trimmed();
-    }
+    const QList<QByteArray> extensionLines = m_parser.headerFieldValues("sec-websocket-extensions");
+    for (const QByteArray &el : extensionLines)
+        appendCommmaSeparatedLineToList(m_extensions, el);
 
     //TODO: authentication field
 
-    m_isValid = !(m_requestUrl.host().isEmpty() ||
-                  resourceName.isEmpty() ||
-                  m_versions.isEmpty() ||
-                  m_key.isEmpty() ||
-                  (verb != QStringLiteral("GET")) ||
-                  (!conversionOk || (httpVersion < 1.1f)) ||
-                  (upgrade.toLower() != QStringLiteral("websocket")) ||
-                  (!connectionValues.contains(QStringLiteral("upgrade"), Qt::CaseInsensitive)));
+    m_isValid = !(m_requestUrl.host().isEmpty() || resourceName.isEmpty() || m_versions.isEmpty()
+                  || m_key.isEmpty() || verb != QStringLiteral("GET") || !conversionOk
+                  || httpVersion < 1.1f || upgrade.compare("websocket", Qt::CaseInsensitive) != 0
+                  || !connectionValues.contains(QStringLiteral("upgrade"), Qt::CaseInsensitive));
     if (Q_UNLIKELY(!m_isValid))
         clear();
 }
diff --git a/src/websockets/qwebsockethandshakerequest_p.h b/src/websockets/qwebsockethandshakerequest_p.h
index c5e9c44..d3681a9 100644
--- a/src/websockets/qwebsockethandshakerequest_p.h
+++ b/src/websockets/qwebsockethandshakerequest_p.h
@@ -54,6 +54,7 @@
 #include <QtCore/QMap>
 #include <QtCore/QString>
 #include <QtCore/QUrl>
+#include <QtNetwork/private/qhttpheaderparser_p.h>
 
 #include "qwebsocketprotocol.h"
 
@@ -74,7 +75,8 @@ public:
     int port() const;
     bool isSecure() const;
     bool isValid() const;
-    QMultiMap<QString, QString> headers() const;
+    QList<QPair<QByteArray, QByteArray>> headers() const;
+    bool hasHeader(const QByteArray &name) const;
     QList<QWebSocketProtocol::Version> versions() const;
     QString key() const;
     QString origin() const;
@@ -84,14 +86,14 @@ public:
     QString resourceName() const;
     QString host() const;
 
-    void readHandshake(QTextStream &textStream, int maxHeaderLineLength, int maxHeaders);
+    void readHandshake(QByteArrayView header, int maxHeaderLineLength);
 
 private:
 
     int m_port;
     bool m_isSecure;
     bool m_isValid;
-    QMultiMap<QString, QString> m_headers;
+    QHttpHeaderParser m_parser;
     QList<QWebSocketProtocol::Version> m_versions;
     QString m_key;
     QString m_origin;
diff --git a/src/websockets/qwebsocketserver_p.cpp b/src/websockets/qwebsocketserver_p.cpp
index f922098..23b38aa 100644
--- a/src/websockets/qwebsocketserver_p.cpp
+++ b/src/websockets/qwebsocketserver_p.cpp
@@ -479,8 +479,7 @@ void QWebSocketServerPrivate::handshakeReceived()
     }
 
     QWebSocketHandshakeRequest request(pTcpSocket->peerPort(), isSecure);
-    QTextStream textStream(header, QIODevice::ReadOnly);
-    request.readHandshake(textStream, MAX_HEADERLINE_LENGTH, MAX_HEADERLINES);
+    request.readHandshake(header, MAX_HEADERLINE_LENGTH);
 
     if (request.isValid()) {
         QWebSocketCorsAuthenticator corsAuthenticator(request.origin());