73 lines
1.9 KiB
Go
73 lines
1.9 KiB
Go
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// Copyright 2014 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package icmp
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import (
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"encoding/binary"
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"golang.org/x/net/internal/iana"
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"golang.org/x/net/ipv4"
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)
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// A ParamProb represents an ICMP parameter problem message body.
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type ParamProb struct {
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Pointer uintptr // offset within the data where the error was detected
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Data []byte // data, known as original datagram field
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Extensions []Extension // extensions
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}
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// Len implements the Len method of MessageBody interface.
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func (p *ParamProb) Len(proto int) int {
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if p == nil {
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return 0
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}
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l, _ := multipartMessageBodyDataLen(proto, true, p.Data, p.Extensions)
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return l
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}
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// Marshal implements the Marshal method of MessageBody interface.
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func (p *ParamProb) Marshal(proto int) ([]byte, error) {
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switch proto {
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case iana.ProtocolICMP:
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if !validExtensions(ipv4.ICMPTypeParameterProblem, p.Extensions) {
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return nil, errInvalidExtension
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}
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b, err := marshalMultipartMessageBody(proto, true, p.Data, p.Extensions)
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if err != nil {
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return nil, err
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}
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b[0] = byte(p.Pointer)
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return b, nil
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case iana.ProtocolIPv6ICMP:
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b := make([]byte, p.Len(proto))
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binary.BigEndian.PutUint32(b[:4], uint32(p.Pointer))
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copy(b[4:], p.Data)
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return b, nil
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default:
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return nil, errInvalidProtocol
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}
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}
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// parseParamProb parses b as an ICMP parameter problem message body.
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func parseParamProb(proto int, typ Type, b []byte) (MessageBody, error) {
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if len(b) < 4 {
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return nil, errMessageTooShort
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}
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p := &ParamProb{}
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if proto == iana.ProtocolIPv6ICMP {
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p.Pointer = uintptr(binary.BigEndian.Uint32(b[:4]))
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p.Data = make([]byte, len(b)-4)
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copy(p.Data, b[4:])
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return p, nil
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}
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p.Pointer = uintptr(b[0])
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var err error
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p.Data, p.Extensions, err = parseMultipartMessageBody(proto, typ, b)
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if err != nil {
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return nil, err
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}
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return p, nil
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}
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