| // 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 icmp contains the implementation of the ICMP and IPv6-ICMP transport |
| // protocols for use in ping. To use it in the networking stack, this package |
| // must be added to the project, and |
| // activated on the stack by passing icmp.ProtocolName (or "icmp") and/or |
| // icmp.ProtocolName6 (or "icmp6") as one of the transport protocols when |
| // calling stack.New(). Then endpoints can be created by passing |
| // icmp.ProtocolNumber or icmp.ProtocolNumber6 as the transport protocol number |
| // when calling Stack.NewEndpoint(). |
| package icmp |
| |
| import ( |
| "encoding/binary" |
| "fmt" |
| |
| "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/tcpip/transport/raw" |
| "github.com/google/netstack/waiter" |
| ) |
| |
| const ( |
| // ProtocolName4 is the string representation of the icmp protocol name. |
| ProtocolName4 = "icmp4" |
| |
| // ProtocolNumber4 is the ICMP protocol number. |
| ProtocolNumber4 = header.ICMPv4ProtocolNumber |
| |
| // ProtocolName6 is the string representation of the icmp protocol name. |
| ProtocolName6 = "icmp6" |
| |
| // ProtocolNumber6 is the IPv6-ICMP protocol number. |
| ProtocolNumber6 = header.ICMPv6ProtocolNumber |
| ) |
| |
| // protocol implements stack.TransportProtocol. |
| type protocol struct { |
| number tcpip.TransportProtocolNumber |
| } |
| |
| // Number returns the ICMP protocol number. |
| func (p *protocol) Number() tcpip.TransportProtocolNumber { |
| return p.number |
| } |
| |
| func (p *protocol) netProto() tcpip.NetworkProtocolNumber { |
| switch p.number { |
| case ProtocolNumber4: |
| return header.IPv4ProtocolNumber |
| case ProtocolNumber6: |
| return header.IPv6ProtocolNumber |
| } |
| panic(fmt.Sprint("unknown protocol number: ", p.number)) |
| } |
| |
| // NewEndpoint creates a new icmp endpoint. It implements |
| // stack.TransportProtocol.NewEndpoint. |
| func (p *protocol) NewEndpoint(stack *stack.Stack, netProto tcpip.NetworkProtocolNumber, waiterQueue *waiter.Queue) (tcpip.Endpoint, *tcpip.Error) { |
| if netProto != p.netProto() { |
| return nil, tcpip.ErrUnknownProtocol |
| } |
| return newEndpoint(stack, netProto, p.number, waiterQueue) |
| } |
| |
| // NewRawEndpoint creates a new raw icmp endpoint. It implements |
| // stack.TransportProtocol.NewRawEndpoint. |
| func (p *protocol) NewRawEndpoint(stack *stack.Stack, netProto tcpip.NetworkProtocolNumber, waiterQueue *waiter.Queue) (tcpip.Endpoint, *tcpip.Error) { |
| if netProto != p.netProto() { |
| return nil, tcpip.ErrUnknownProtocol |
| } |
| return raw.NewEndpoint(stack, netProto, p.number, waiterQueue) |
| } |
| |
| // MinimumPacketSize returns the minimum valid icmp packet size. |
| func (p *protocol) MinimumPacketSize() int { |
| switch p.number { |
| case ProtocolNumber4: |
| return header.ICMPv4MinimumSize |
| case ProtocolNumber6: |
| return header.ICMPv6EchoMinimumSize |
| } |
| panic(fmt.Sprint("unknown protocol number: ", p.number)) |
| } |
| |
| // ParsePorts in case of ICMP sets src to 0, dst to ICMP ID, and err to nil. |
| func (p *protocol) ParsePorts(v buffer.View) (src, dst uint16, err *tcpip.Error) { |
| switch p.number { |
| case ProtocolNumber4: |
| return 0, binary.BigEndian.Uint16(v[header.ICMPv4PayloadOffset:]), nil |
| case ProtocolNumber6: |
| return 0, binary.BigEndian.Uint16(v[header.ICMPv6MinimumSize:]), nil |
| } |
| panic(fmt.Sprint("unknown protocol number: ", p.number)) |
| } |
| |
| // 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(ProtocolName4, func() stack.TransportProtocol { |
| return &protocol{ProtocolNumber4} |
| }) |
| |
| stack.RegisterTransportProtocolFactory(ProtocolName6, func() stack.TransportProtocol { |
| return &protocol{ProtocolNumber6} |
| }) |
| } |