69 lines
1.6 KiB
Go
69 lines
1.6 KiB
Go
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package sctp
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import (
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"encoding/binary"
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"errors"
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"fmt"
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)
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/*
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chunkShutdown represents an SCTP Chunk of type chunkShutdown
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Type = 7 | Chunk Flags | Length = 8 |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Cumulative TSN Ack |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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type chunkShutdown struct {
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chunkHeader
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cumulativeTSNAck uint32
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}
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const (
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cumulativeTSNAckLength = 4
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)
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var (
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errInvalidChunkSize = errors.New("invalid chunk size")
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errChunkTypeNotShutdown = errors.New("ChunkType is not of type SHUTDOWN")
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)
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func (c *chunkShutdown) unmarshal(raw []byte) error {
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if err := c.chunkHeader.unmarshal(raw); err != nil {
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return err
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}
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if c.typ != ctShutdown {
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return fmt.Errorf("%w: actually is %s", errChunkTypeNotShutdown, c.typ.String())
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}
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if len(c.raw) != cumulativeTSNAckLength {
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return errInvalidChunkSize
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}
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c.cumulativeTSNAck = binary.BigEndian.Uint32(c.raw[0:])
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return nil
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}
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func (c *chunkShutdown) marshal() ([]byte, error) {
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out := make([]byte, cumulativeTSNAckLength)
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binary.BigEndian.PutUint32(out[0:], c.cumulativeTSNAck)
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c.typ = ctShutdown
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c.raw = out
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return c.chunkHeader.marshal()
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}
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func (c *chunkShutdown) check() (abort bool, err error) {
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return false, nil
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}
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// String makes chunkShutdown printable
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func (c *chunkShutdown) String() string {
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return c.chunkHeader.String()
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}
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