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|
package sctp
import (
"errors"
"fmt"
)
/*
chunkHeartbeat represents an SCTP Chunk of type HEARTBEAT
An endpoint should send this chunk to its peer endpoint to probe the
reachability of a particular destination transport address defined in
the present association.
The parameter field contains the Heartbeat Information, which is a
variable-length opaque data structure understood only by the sender.
0 1 2 3
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 4 | Chunk Flags | Heartbeat Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Heartbeat Information TLV (Variable-Length) |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Defined as a variable-length parameter using the format described
in Section 3.2.1, i.e.:
Variable Parameters Status Type Value
-------------------------------------------------------------
heartbeat Info Mandatory 1
*/
type chunkHeartbeat struct {
chunkHeader
params []param
}
// Heartbeat chunk errors
var (
ErrChunkTypeNotHeartbeat = errors.New("ChunkType is not of type HEARTBEAT")
ErrHeartbeatNotLongEnoughInfo = errors.New("heartbeat is not long enough to contain Heartbeat Info")
ErrParseParamTypeFailed = errors.New("failed to parse param type")
ErrHeartbeatParam = errors.New("heartbeat should only have HEARTBEAT param")
ErrHeartbeatChunkUnmarshal = errors.New("failed unmarshalling param in Heartbeat Chunk")
)
func (h *chunkHeartbeat) unmarshal(raw []byte) error {
if err := h.chunkHeader.unmarshal(raw); err != nil {
return err
} else if h.typ != ctHeartbeat {
return fmt.Errorf("%w: actually is %s", ErrChunkTypeNotHeartbeat, h.typ.String())
}
if len(raw) <= chunkHeaderSize {
return fmt.Errorf("%w: %d", ErrHeartbeatNotLongEnoughInfo, len(raw))
}
pType, err := parseParamType(raw[chunkHeaderSize:])
if err != nil {
return fmt.Errorf("%w: %v", ErrParseParamTypeFailed, err)
}
if pType != heartbeatInfo {
return fmt.Errorf("%w: instead have %s", ErrHeartbeatParam, pType.String())
}
p, err := buildParam(pType, raw[chunkHeaderSize:])
if err != nil {
return fmt.Errorf("%w: %v", ErrHeartbeatChunkUnmarshal, err)
}
h.params = append(h.params, p)
return nil
}
func (h *chunkHeartbeat) Marshal() ([]byte, error) {
return nil, ErrUnimplemented
}
func (h *chunkHeartbeat) check() (abort bool, err error) {
return false, nil
}
|
