Support datagrams in QuicTransport.

gfe-relnote: n/a (no functional change to production code)
PiperOrigin-RevId: 288493541
Change-Id: I6d2a791ae062701ad4b9fb650ab267566373675f

quic/tools/quic_transport_simple_server_session.cc

diff --git a/quic/tools/quic_transport_simple_server_session.cc b/quic/tools/quic_transport_simple_server_session.cc
index 9fe3dfd..49c86e5 100644
--- a/quic/tools/quic_transport_simple_server_session.cc
+++ b/quic/tools/quic_transport_simple_server_session.cc
@@ -8,6 +8,7 @@
 
 #include "url/gurl.h"
 #include "url/origin.h"
+#include "net/third_party/quiche/src/quic/core/quic_buffer_allocator.h"
 #include "net/third_party/quiche/src/quic/core/quic_types.h"
 #include "net/third_party/quiche/src/quic/core/quic_versions.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_flags.h"
@@ -212,6 +213,18 @@
   return false;
 }
 
+void QuicTransportSimpleServerSession::OnMessageReceived(
+    quiche::QuicheStringPiece message) {
+  if (mode_ != ECHO) {
+    return;
+  }
+  QuicUniqueBufferPtr buffer = MakeUniqueBuffer(
+      connection()->helper()->GetStreamSendBufferAllocator(), message.size());
+  memcpy(buffer.get(), message.data(), message.size());
+  datagram_queue()->SendOrQueueDatagram(
+      QuicMemSlice(std::move(buffer), message.size()));
+}
+
 void QuicTransportSimpleServerSession::MaybeEchoStreamsBack() {
   while (!streams_to_echo_back_.empty() &&
          CanOpenNextOutgoingUnidirectionalStream()) {

quic/tools/quic_transport_simple_server_session.h

diff --git a/quic/tools/quic_transport_simple_server_session.h b/quic/tools/quic_transport_simple_server_session.h
index a2dd6be..ccdf28b 100644
--- a/quic/tools/quic_transport_simple_server_session.h
+++ b/quic/tools/quic_transport_simple_server_session.h
@@ -51,6 +51,7 @@
   void OnCanCreateNewOutgoingStream(bool unidirectional) override;
   bool CheckOrigin(url::Origin origin) override;
   bool ProcessPath(const GURL& url) override;
+  void OnMessageReceived(quiche::QuicheStringPiece message) override;
 
   void EchoStreamBack(const std::string& data) {
     streams_to_echo_back_.push_back(data);