Extract network datagram endpoint common facilities

...from the UDP endpoint.

Datagram-based transport endpoints (e.g. UDP, RAW IP) can share a lot
of their write path due to the datagram-based nature of these endpoints.
Extract the common facilities from UDP so they can be shared with other
transport endpoints (in a later change).

Test: UDP syscall tests.
PiperOrigin-RevId: 394347774

1 files changed, 16 insertions, 0 deletions

diff --git a/pkg/tcpip/transport/transport.go b/pkg/tcpip/transport/transport.go
new file mode 100644
index 000000000..4c2ae87f4
--- /dev/null
+++ b/pkg/tcpip/transport/transport.go
@@ -0,0 +1,16 @@
+// Copyright 2021 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package transport supports transport protocols.
+package transport