67 lines
1.4 KiB
Go
67 lines
1.4 KiB
Go
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package madns
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import (
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"errors"
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"fmt"
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ma "github.com/multiformats/go-multiaddr"
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)
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var Dns4Protocol = ma.Protocol{
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Code: 54,
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Size: ma.LengthPrefixedVarSize,
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Name: "dns4",
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VCode: ma.CodeToVarint(54),
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Transcoder: DnsTranscoder,
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}
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var Dns6Protocol = ma.Protocol{
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Code: 55,
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Size: ma.LengthPrefixedVarSize,
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Name: "dns6",
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VCode: ma.CodeToVarint(55),
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Transcoder: DnsTranscoder,
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}
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var DnsaddrProtocol = ma.Protocol{
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Code: 56,
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Size: ma.LengthPrefixedVarSize,
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Name: "dnsaddr",
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VCode: ma.CodeToVarint(56),
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Transcoder: DnsTranscoder,
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}
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func init() {
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err := ma.AddProtocol(Dns4Protocol)
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if err != nil {
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panic(fmt.Errorf("error registering dns4 protocol: %s", err))
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}
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err = ma.AddProtocol(Dns6Protocol)
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if err != nil {
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panic(fmt.Errorf("error registering dns6 protocol: %s", err))
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}
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err = ma.AddProtocol(DnsaddrProtocol)
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if err != nil {
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panic(fmt.Errorf("error registering dnsaddr protocol: %s", err))
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}
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}
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var DnsTranscoder = ma.NewTranscoderFromFunctions(dnsStB, dnsBtS)
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func dnsStB(s string) ([]byte, error) {
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size := ma.CodeToVarint(len(s))
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b := append(size, []byte(s)...)
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return b, nil
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}
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func dnsBtS(b []byte) (string, error) {
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size, n, err := ma.ReadVarintCode(b)
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if err != nil {
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return "", err
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}
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b = b[n:]
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if len(b) != size {
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return "", errors.New("inconsistent lengths")
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}
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return string(b), nil
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}
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