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Diffstat (limited to 'pkg/tcpip/transport/icmp/protocol.go')
-rw-r--r-- | pkg/tcpip/transport/icmp/protocol.go | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/pkg/tcpip/transport/icmp/protocol.go b/pkg/tcpip/transport/icmp/protocol.go new file mode 100644 index 000000000..954fde9d8 --- /dev/null +++ b/pkg/tcpip/transport/icmp/protocol.go @@ -0,0 +1,136 @@ +// 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" + + "gvisor.googlesource.com/gvisor/pkg/tcpip" + "gvisor.googlesource.com/gvisor/pkg/tcpip/buffer" + "gvisor.googlesource.com/gvisor/pkg/tcpip/header" + "gvisor.googlesource.com/gvisor/pkg/tcpip/stack" + "gvisor.googlesource.com/gvisor/pkg/tcpip/transport/raw" + "gvisor.googlesource.com/gvisor/pkg/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.ICMPv4EchoMinimumSize + case ProtocolNumber6: + return header.ICMPv6EchoMinimumSize + } + panic(fmt.Sprint("unknown protocol number: ", p.number)) +} + +// ParsePorts returns the source and destination ports stored in the given icmp +// packet. +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.ICMPv4MinimumSize:]), 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} + }) +} |