| // Copyright 2018 Google Inc. |
| // |
| // 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 udp contains the implementation of the UDP transport protocol. To use |
| // it in the networking stack, this package must be added to the project, and |
| // activated on the stack by passing udp.ProtocolName (or "udp") as one of the |
| // transport protocols when calling stack.New(). Then endpoints can be created |
| // by passing udp.ProtocolNumber as the transport protocol number when calling |
| // Stack.NewEndpoint(). |
| package udp |
| |
| import ( |
| "github.com/google/netstack/tcpip" |
| "github.com/google/netstack/tcpip/buffer" |
| "github.com/google/netstack/tcpip/header" |
| "github.com/google/netstack/tcpip/stack" |
| "github.com/google/netstack/waiter" |
| ) |
| |
| const ( |
| // ProtocolName is the string representation of the udp protocol name. |
| ProtocolName = "udp" |
| |
| // ProtocolNumber is the udp protocol number. |
| ProtocolNumber = header.UDPProtocolNumber |
| ) |
| |
| type protocol struct{} |
| |
| // Number returns the udp protocol number. |
| func (*protocol) Number() tcpip.TransportProtocolNumber { |
| return ProtocolNumber |
| } |
| |
| // NewEndpoint creates a new udp endpoint. |
| func (*protocol) NewEndpoint(stack *stack.Stack, netProto tcpip.NetworkProtocolNumber, waiterQueue *waiter.Queue) (tcpip.Endpoint, *tcpip.Error) { |
| return newEndpoint(stack, netProto, waiterQueue), nil |
| } |
| |
| // MinimumPacketSize returns the minimum valid udp packet size. |
| func (*protocol) MinimumPacketSize() int { |
| return header.UDPMinimumSize |
| } |
| |
| // ParsePorts returns the source and destination ports stored in the given udp |
| // packet. |
| func (*protocol) ParsePorts(v buffer.View) (src, dst uint16, err *tcpip.Error) { |
| h := header.UDP(v) |
| return h.SourcePort(), h.DestinationPort(), nil |
| } |
| |
| // HandleUnknownDestinationPacket handles packets targeted at this protocol but |
| // that don't match any existing endpoint. |
| func (p *protocol) HandleUnknownDestinationPacket(*stack.Route, stack.TransportEndpointID, buffer.VectorisedView) bool { |
| return true |
| } |
| |
| // SetOption implements TransportProtocol.SetOption. |
| func (p *protocol) SetOption(option interface{}) *tcpip.Error { |
| return tcpip.ErrUnknownProtocolOption |
| } |
| |
| // Option implements TransportProtocol.Option. |
| func (p *protocol) Option(option interface{}) *tcpip.Error { |
| return tcpip.ErrUnknownProtocolOption |
| } |
| |
| func init() { |
| stack.RegisterTransportProtocolFactory(ProtocolName, func() stack.TransportProtocol { |
| return &protocol{} |
| }) |
| } |