HTTP/2 - implement the proper 'h2c' (protocol upgrade)

Without TLS (and thus ALPN/NPN negotiation) HTTP/2 requires
a protocol upgrade procedure, as described in RFC 7540, 3.2.
We start as HTTP/1.1 (and thus we create QHttpProtocolHandler first),
augmenting the headers we send with 'Upgrade: h2c'. In case
we receive HTTP/1.1 response with status code 101 ('Switching
Protocols'), we continue as HTTP/2 session, creating QHttp2ProtocolHandler
and pretending the first request we sent was HTTP/2 request
on a real HTTP/2 stream. If the first response is something different
from 101, we continue as HTTP/1.1. This change also required
auto-test update: our toy-server now has to respond to
the initial HTTP/1.1 request on a platform without ALPN/NPN.
As a bonus a subtle flakyness in 'goaway' auto-test went
away (well, it was fixed).

[ChangeLog][QtNetwork][HTTP/2] In case of clear text HTTP/2 we
now initiate a required protocol upgrade procedure instead of
'H2Direct' connection.

Task-number: QTBUG-61397
Change-Id: I573fa304fdaf661490159037dc47775d97c8ea5b
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/network/access/http2/http2protocol_p.h b/src/network/access/http2/http2protocol_p.h
index 5d730404bb..b26ff0e9f4 100644
--- a/src/network/access/http2/http2protocol_p.h
+++ b/src/network/access/http2/http2protocol_p.h
@@ -59,6 +59,8 @@
 
 QT_BEGIN_NAMESPACE
 
+class QHttpNetworkRequest;
+class QHttpNetworkReply;
 class QString;
 
 namespace Http2
@@ -132,6 +134,7 @@ enum Http2PredefinedParameters
 const quint32 lastValidStreamID((quint32(1) << 31) - 1); // HTTP/2, 5.1.1
 
 extern const Q_AUTOTEST_EXPORT char Http2clientPreface[clientPrefaceLength];
+void prepare_for_protocol_upgrade(QHttpNetworkRequest &request);
 
 enum class FrameStatus
 {
@@ -169,6 +172,9 @@ enum Http2Error
 void qt_error(quint32 errorCode, QNetworkReply::NetworkError &error, QString &errorString);
 QString qt_error_string(quint32 errorCode);
 QNetworkReply::NetworkError qt_error(quint32 errorCode);
+bool is_PUSH_PROMISE_enabled();
+bool is_protocol_upgraded(const QHttpNetworkReply &reply);
+struct Frame default_SETTINGS_frame();
 
 }