84 lines
2.7 KiB
Go
84 lines
2.7 KiB
Go
package sctp
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import (
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"errors"
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"fmt"
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)
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/*
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chunkHeartbeat represents an SCTP Chunk of type HEARTBEAT
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An endpoint should send this chunk to its peer endpoint to probe the
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reachability of a particular destination transport address defined in
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the present association.
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The parameter field contains the Heartbeat Information, which is a
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variable-length opaque data structure understood only by the sender.
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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 = 4 | Chunk Flags | Heartbeat Length |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Heartbeat Information TLV (Variable-Length) |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Defined as a variable-length parameter using the format described
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in Section 3.2.1, i.e.:
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Variable Parameters Status Type Value
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-------------------------------------------------------------
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heartbeat Info Mandatory 1
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*/
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type chunkHeartbeat struct {
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chunkHeader
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params []param
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}
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var (
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errChunkTypeNotHeartbeat = errors.New("ChunkType is not of type HEARTBEAT")
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errHeartbeatNotLongEnoughInfo = errors.New("heartbeat is not long enough to contain Heartbeat Info")
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errParseParamTypeFailed = errors.New("failed to parse param type")
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errHeartbeatParam = errors.New("heartbeat should only have HEARTBEAT param")
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errHeartbeatChunkUnmarshal = errors.New("failed unmarshalling param in Heartbeat Chunk")
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)
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func (h *chunkHeartbeat) unmarshal(raw []byte) error {
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if err := h.chunkHeader.unmarshal(raw); err != nil {
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return err
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} else if h.typ != ctHeartbeat {
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return fmt.Errorf("%w: actually is %s", errChunkTypeNotHeartbeat, h.typ.String())
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}
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if len(raw) <= chunkHeaderSize {
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return fmt.Errorf("%w: %d", errHeartbeatNotLongEnoughInfo, len(raw))
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}
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pType, err := parseParamType(raw[chunkHeaderSize:])
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if err != nil {
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return fmt.Errorf("%w: %v", errParseParamTypeFailed, err)
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}
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if pType != heartbeatInfo {
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return fmt.Errorf("%w: instead have %s", errHeartbeatParam, pType.String())
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}
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p, err := buildParam(pType, raw[chunkHeaderSize:])
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if err != nil {
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return fmt.Errorf("%w: %v", errHeartbeatChunkUnmarshal, err)
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}
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h.params = append(h.params, p)
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return nil
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}
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func (h *chunkHeartbeat) Marshal() ([]byte, error) {
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return nil, errUnimplemented
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}
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func (h *chunkHeartbeat) check() (abort bool, err error) {
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return false, nil
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}
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