/
outer-header-removal.go
77 lines (67 loc) · 2.05 KB
/
outer-header-removal.go
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// Copyright 2019-2021 go-pfcp authors. All rights reserved.
// Use of this source code is governed by a MIT-style license that can be
// found in the LICENSE file.
package ie
import "io"
// NewOuterHeaderRemoval creates a new OuterHeaderRemoval IE.
func NewOuterHeaderRemoval(desc, ext uint8) *IE {
return newUint16ValIE(OuterHeaderRemoval, uint16(desc)<<8|uint16(ext))
}
// OuterHeaderRemoval returns OuterHeaderRemoval in []byte if the type of IE matches.
func (i *IE) OuterHeaderRemoval() ([]byte, error) {
// The size of the OuterHeaderRemoval IE was one octet in 3GPP TS 29.244 up to V15.3.0,
// but it has been changed to two octets since V15.4.0.
// For backward compatibility, one octet is also accepted.
if len(i.Payload) < 1 {
return nil, io.ErrUnexpectedEOF
}
switch i.Type {
case OuterHeaderRemoval:
return i.Payload, nil
case CreatePDR:
ies, err := i.CreatePDR()
if err != nil {
return nil, err
}
for _, x := range ies {
if x.Type == OuterHeaderRemoval {
return x.OuterHeaderRemoval()
}
}
return nil, ErrIENotFound
case UpdatePDR:
ies, err := i.UpdatePDR()
if err != nil {
return nil, err
}
for _, x := range ies {
if x.Type == OuterHeaderRemoval {
return x.OuterHeaderRemoval()
}
}
return nil, ErrIENotFound
default:
return nil, &InvalidTypeError{Type: i.Type}
}
}
// OuterHeaderRemovalDescription returns OuterHeaderRemovalDescription in uint8 if the type of IE matches.
func (i *IE) OuterHeaderRemovalDescription() (uint8, error) {
v, err := i.OuterHeaderRemoval()
if err != nil {
return 0, err
}
return v[0], nil
}
// GTPUExternsionHeaderDeletion returns GTPUExternsionHeaderDeletion in uint8 if the type of IE matches.
func (i *IE) GTPUExternsionHeaderDeletion() (uint8, error) {
v, err := i.OuterHeaderRemoval()
if err != nil {
return 0, err
}
// If the size of the payload is less than two octets because the original was formatted before
// 3GPP TS 29.244 V15.3.0, 0 is returned as GTPUExternsionHeaderDeletion.
if len(v) < 2 {
return 0, io.ErrUnexpectedEOF
}
return v[1], nil
}