104 lines
3.6 KiB
Go
104 lines
3.6 KiB
Go
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// Copyright 2019 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Package injectable provides a muxed injectable endpoint.
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package injectable
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import (
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"gvisor.googlesource.com/gvisor/pkg/tcpip"
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"gvisor.googlesource.com/gvisor/pkg/tcpip/buffer"
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"gvisor.googlesource.com/gvisor/pkg/tcpip/stack"
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)
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// MuxedInjectableEndpoint is an injectable multi endpoint. The endpoint has
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// trivial routing rules that determine which InjectableEndpoint a given packet
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// will be written to. Note that HandleLocal works differently for this
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// endpoint (see WritePacket).
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type MuxedInjectableEndpoint struct {
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routes map[tcpip.Address]stack.InjectableLinkEndpoint
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dispatcher stack.NetworkDispatcher
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}
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// MTU implements stack.LinkEndpoint.
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func (m *MuxedInjectableEndpoint) MTU() uint32 {
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minMTU := ^uint32(0)
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for _, endpoint := range m.routes {
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if endpointMTU := endpoint.MTU(); endpointMTU < minMTU {
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minMTU = endpointMTU
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}
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}
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return minMTU
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}
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// Capabilities implements stack.LinkEndpoint.
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func (m *MuxedInjectableEndpoint) Capabilities() stack.LinkEndpointCapabilities {
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minCapabilities := stack.LinkEndpointCapabilities(^uint(0))
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for _, endpoint := range m.routes {
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minCapabilities &= endpoint.Capabilities()
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}
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return minCapabilities
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}
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// MaxHeaderLength implements stack.LinkEndpoint.
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func (m *MuxedInjectableEndpoint) MaxHeaderLength() uint16 {
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minHeaderLen := ^uint16(0)
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for _, endpoint := range m.routes {
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if headerLen := endpoint.MaxHeaderLength(); headerLen < minHeaderLen {
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minHeaderLen = headerLen
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}
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}
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return minHeaderLen
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}
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// LinkAddress implements stack.LinkEndpoint.
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func (m *MuxedInjectableEndpoint) LinkAddress() tcpip.LinkAddress {
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return ""
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}
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// Attach implements stack.LinkEndpoint.
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func (m *MuxedInjectableEndpoint) Attach(dispatcher stack.NetworkDispatcher) {
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for _, endpoint := range m.routes {
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endpoint.Attach(dispatcher)
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}
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m.dispatcher = dispatcher
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}
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// IsAttached implements stack.LinkEndpoint.
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func (m *MuxedInjectableEndpoint) IsAttached() bool {
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return m.dispatcher != nil
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}
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// Inject implements stack.InjectableLinkEndpoint.
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func (m *MuxedInjectableEndpoint) Inject(protocol tcpip.NetworkProtocolNumber, vv buffer.VectorisedView) {
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m.dispatcher.DeliverNetworkPacket(m, "" /* remote */, "" /* local */, protocol, vv)
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}
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// WritePacket writes outbound packets to the appropriate LinkInjectableEndpoint
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// based on the RemoteAddress. HandleLocal only works if r.RemoteAddress has a
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// route registered in this endpoint.
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func (m *MuxedInjectableEndpoint) WritePacket(r *stack.Route, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
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if endpoint, ok := m.routes[r.RemoteAddress]; ok {
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return endpoint.WritePacket(r, hdr, payload, protocol)
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}
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return tcpip.ErrNoRoute
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}
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// NewMuxedInjectableEndpoint creates a new multi-fd-based injectable endpoint.
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func NewMuxedInjectableEndpoint(routes map[tcpip.Address]stack.InjectableLinkEndpoint, mtu uint32) (tcpip.LinkEndpointID, *MuxedInjectableEndpoint) {
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e := &MuxedInjectableEndpoint{
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routes: routes,
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}
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return stack.RegisterLinkEndpoint(e), e
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}
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