/
param_outgoing_reset_request.go
87 lines (78 loc) · 3.73 KB
/
param_outgoing_reset_request.go
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package sctp
import (
"encoding/binary"
"errors"
)
const (
paramOutgoingResetRequestStreamIdentifiersOffset = 12
)
// This parameter is used by the sender to request the reset of some or
// all outgoing streams.
// 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
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Parameter Type = 13 | Parameter Length = 16 + 2 * N |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Re-configuration Request Sequence Number |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Re-configuration Response Sequence Number |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Sender's Last Assigned TSN |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Stream Number 1 (optional) | Stream Number 2 (optional) |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// / ...... /
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | Stream Number N-1 (optional) | Stream Number N (optional) |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
type paramOutgoingResetRequest struct {
paramHeader
// reconfigRequestSequenceNumber is used to identify the request. It is a monotonically
// increasing number that is initialized to the same value as the
// initial TSN. It is increased by 1 whenever sending a new Re-
// configuration Request Parameter.
reconfigRequestSequenceNumber uint32
// When this Outgoing SSN Reset Request Parameter is sent in response
// to an Incoming SSN Reset Request Parameter, this parameter is also
// an implicit response to the incoming request. This field then
// holds the Re-configuration Request Sequence Number of the incoming
// request. In other cases, it holds the next expected
// Re-configuration Request Sequence Number minus 1.
reconfigResponseSequenceNumber uint32
// This value holds the next TSN minus 1 -- in other words, the last
// TSN that this sender assigned.
senderLastTSN uint32
// This optional field, if included, is used to indicate specific
// streams that are to be reset. If no streams are listed, then all
// streams are to be reset.
streamIdentifiers []uint16
}
func (r *paramOutgoingResetRequest) marshal() ([]byte, error) {
r.typ = outSSNResetReq
r.raw = make([]byte, paramOutgoingResetRequestStreamIdentifiersOffset+2*len(r.streamIdentifiers))
binary.BigEndian.PutUint32(r.raw, r.reconfigRequestSequenceNumber)
binary.BigEndian.PutUint32(r.raw[4:], r.reconfigResponseSequenceNumber)
binary.BigEndian.PutUint32(r.raw[8:], r.senderLastTSN)
for i, sID := range r.streamIdentifiers {
binary.BigEndian.PutUint16(r.raw[paramOutgoingResetRequestStreamIdentifiersOffset+2*i:], sID)
}
return r.paramHeader.marshal()
}
func (r *paramOutgoingResetRequest) unmarshal(raw []byte) (param, error) {
err := r.paramHeader.unmarshal(raw)
if err != nil {
return nil, err
}
if len(r.raw) < paramOutgoingResetRequestStreamIdentifiersOffset {
return nil, errors.New("outgoing SSN reset request parameter too short")
}
r.reconfigRequestSequenceNumber = binary.BigEndian.Uint32(r.raw)
r.reconfigResponseSequenceNumber = binary.BigEndian.Uint32(r.raw[4:])
r.senderLastTSN = binary.BigEndian.Uint32(r.raw[8:])
lim := (len(r.raw) - paramOutgoingResetRequestStreamIdentifiersOffset) / 2
r.streamIdentifiers = make([]uint16, lim)
for i := 0; i < lim; i++ {
r.streamIdentifiers[i] = binary.BigEndian.Uint16(r.raw[paramOutgoingResetRequestStreamIdentifiersOffset+2*i:])
}
return r, nil
}