diff options
| -rwxr-xr-x | pkg/tcpip/link/channel/channel.go | 138 | ||||
| -rwxr-xr-x | pkg/tcpip/link/channel/channel_state_autogen.go | 4 |
2 files changed, 142 insertions, 0 deletions
diff --git a/pkg/tcpip/link/channel/channel.go b/pkg/tcpip/link/channel/channel.go new file mode 100755 index 000000000..18adb2085 --- /dev/null +++ b/pkg/tcpip/link/channel/channel.go @@ -0,0 +1,138 @@ +// Copyright 2018 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 channel provides the implemention of channel-based data-link layer +// endpoints. Such endpoints allow injection of inbound packets and store +// outbound packets in a channel. +package channel + +import ( + "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/buffer" + "gvisor.dev/gvisor/pkg/tcpip/stack" +) + +// PacketInfo holds all the information about an outbound packet. +type PacketInfo struct { + Header buffer.View + Payload buffer.View + Proto tcpip.NetworkProtocolNumber + GSO *stack.GSO +} + +// Endpoint is link layer endpoint that stores outbound packets in a channel +// and allows injection of inbound packets. +type Endpoint struct { + dispatcher stack.NetworkDispatcher + mtu uint32 + linkAddr tcpip.LinkAddress + GSO bool + + // C is where outbound packets are queued. + C chan PacketInfo +} + +// New creates a new channel endpoint. +func New(size int, mtu uint32, linkAddr tcpip.LinkAddress) *Endpoint { + return &Endpoint{ + C: make(chan PacketInfo, size), + mtu: mtu, + linkAddr: linkAddr, + } +} + +// Drain removes all outbound packets from the channel and counts them. +func (e *Endpoint) Drain() int { + c := 0 + for { + select { + case <-e.C: + c++ + default: + return c + } + } +} + +// Inject injects an inbound packet. +func (e *Endpoint) Inject(protocol tcpip.NetworkProtocolNumber, vv buffer.VectorisedView) { + e.InjectLinkAddr(protocol, "", vv) +} + +// InjectLinkAddr injects an inbound packet with a remote link address. +func (e *Endpoint) InjectLinkAddr(protocol tcpip.NetworkProtocolNumber, remote tcpip.LinkAddress, vv buffer.VectorisedView) { + e.dispatcher.DeliverNetworkPacket(e, remote, "" /* local */, protocol, vv.Clone(nil)) +} + +// Attach saves the stack network-layer dispatcher for use later when packets +// are injected. +func (e *Endpoint) Attach(dispatcher stack.NetworkDispatcher) { + e.dispatcher = dispatcher +} + +// IsAttached implements stack.LinkEndpoint.IsAttached. +func (e *Endpoint) IsAttached() bool { + return e.dispatcher != nil +} + +// MTU implements stack.LinkEndpoint.MTU. It returns the value initialized +// during construction. +func (e *Endpoint) MTU() uint32 { + return e.mtu +} + +// Capabilities implements stack.LinkEndpoint.Capabilities. +func (e *Endpoint) Capabilities() stack.LinkEndpointCapabilities { + caps := stack.LinkEndpointCapabilities(0) + if e.GSO { + caps |= stack.CapabilityGSO + } + return caps +} + +// GSOMaxSize returns the maximum GSO packet size. +func (*Endpoint) GSOMaxSize() uint32 { + return 1 << 15 +} + +// MaxHeaderLength returns the maximum size of the link layer header. Given it +// doesn't have a header, it just returns 0. +func (*Endpoint) MaxHeaderLength() uint16 { + return 0 +} + +// LinkAddress returns the link address of this endpoint. +func (e *Endpoint) LinkAddress() tcpip.LinkAddress { + return e.linkAddr +} + +// WritePacket stores outbound packets into the channel. +func (e *Endpoint) WritePacket(_ *stack.Route, gso *stack.GSO, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error { + p := PacketInfo{ + Header: hdr.View(), + Proto: protocol, + Payload: payload.ToView(), + GSO: gso, + } + + select { + case e.C <- p: + default: + } + + return nil +} + +// Wait implements stack.LinkEndpoint.Wait. +func (*Endpoint) Wait() {} diff --git a/pkg/tcpip/link/channel/channel_state_autogen.go b/pkg/tcpip/link/channel/channel_state_autogen.go new file mode 100755 index 000000000..19e9e5a2b --- /dev/null +++ b/pkg/tcpip/link/channel/channel_state_autogen.go @@ -0,0 +1,4 @@ +// automatically generated by stateify. + +package channel + |