bpv7.cddl

bpv7_start = bundle / #6.55799(bundle)

; Times before 2000 are invalid
dtn-time = uint

; CRC enumerated type
crc-type = &(
  crc-none: 0,
  crc-16bit: 1,
  crc-32bit: 2
)
; Either 16-bit or 32-bit
crc-value = (bstr .size 2) / (bstr .size 4)

creation-timestamp = [
  dtn-time, ; absolute time of creation
  sequence: uint ; sequence within the time
]

eid = $eid .within eid-structure
eid-structure = [
  uri-code: uint,
  SSP: any
]
$eid /= [
  uri-code: 1,
  SSP: (tstr / 0)
]
$eid /= [
  uri-code: 2,
  SSP: [
    nodenum: uint,
    servicenum: uint
  ]
]

; The root bundle array
bundle = [primary-block, *extension-block, payload-block]

primary-block = [
  version: 7,
  bundle-control-flags,
  crc-type,
  destination: eid,
  source-node: eid,
  report-to: eid,
  creation-timestamp,
  lifetime: uint,
  ? (
    fragment-offset: uint,
    total-application-data-length: uint
  ),
  ? crc-value,
]
bundle-control-flags = uint .bits bundleflagbits
bundleflagbits = &(
  reserved: 21,
  reserved: 20,
  reserved: 19,
  bundle-deletion-status-reports-are-requested: 18,
  bundle-delivery-status-reports-are-requested: 17,
  bundle-forwarding-status-reports-are-requested: 16,
  reserved: 15,
  bundle-reception-status-reports-are-requested: 14,
  reserved: 13,
  reserved: 12,
  reserved: 11,
  reserved: 10,
  reserved: 9,
  reserved: 8,
  reserved: 7,
  status-time-is-requested-in-all-status-reports: 6,
  user-application-acknowledgement-is-requested: 5,
  reserved: 4,
  reserved: 3,
  bundle-must-not-be-fragmented: 2,
  payload-is-an-administrative-record: 1,
  bundle-is-a-fragment: 0
)

; Abstract shared structure of all non-primary blocks
canonical-block-structure = [
  block-type-code: uint,
  block-number: uint,
  block-control-flags,
  crc-type,
  ; Each block type defines the content within the bytestring
  block-type-specific-data,
  ? crc-value
]
block-control-flags = uint .bits blockflagbits
blockflagbits = &(
  reserved: 7,
  reserved: 6,
  reserved: 5,
  block-must-be-removed-from-bundle-if-it-cannot-be-processed: 4,
  reserved: 3,
  bundle-must-be-deleted-if-block-cannot-be-processed: 2,
  status-report-must-be-transmitted-if-block-cannot-be-processed: 1,
  block-must-be-replicated-in-every-fragment: 0
)
block-type-specific-data = bstr / #6.24(bstr)
; Actual CBOR data embedded in a bytestring, with optional tag to indicate so.
; Additional plain bstr allows ciphertext data.
embedded-cbor<Item> = (bstr .cbor Item) / #6.24(bstr .cbor Item) / bstr

; Extension block type, which does not specialize other than the code/number
extension-block = $extension-block .within canonical-block-structure
; Generic shared structure of all non-primary blocks
extension-block-use<CodeValue, BlockData> = [
  block-type-code: CodeValue,
  block-number: (uint .gt 1),
  block-control-flags,
  crc-type,
  BlockData,
  ? crc-value
]

; Payload block type
payload-block = payload-block-structure .within canonical-block-structure
payload-block-structure = [
  block-type-code: 1,
  block-number: 1,
  block-control-flags,
  crc-type,
  $payload-block-data,
  ? crc-value
]

; Arbitrary payload data, including non-CBOR bytestring
$payload-block-data /= block-type-specific-data


; Administrative record as a payload data specialization
$payload-block-data /= embedded-cbor<admin-record>
admin-record = $admin-record .within admin-record-structure
admin-record-structure = [
  record-type-code: uint,
  record-content: any
]
; Only one defined record type
$admin-record /= [1, status-record-content]
status-record-content = [
  bundle-status-information,
  status-report-reason-code: uint,
  source-node-eid: eid,
  subject-creation-timestamp: creation-timestamp,
  ? (
    subject-payload-offset: uint,
    subject-payload-length: uint
  )
]
bundle-status-information = [
  reporting-node-received-bundle: status-info-content,
  reporting-node-forwarded-bundle: status-info-content,
  reporting-node-delivered-bundle: status-info-content,
  reporting-node-deleted-bundle: status-info-content
]
status-info-content = [
  status-indicator: bool,
  ? timestamp: dtn-time
]


; Previous Node extension block
$extension-block /=
  extension-block-use<6, embedded-cbor<ext-data-previous-node>>
ext-data-previous-node = eid

; Bundle Age extension block
$extension-block /= 
  extension-block-use<7, embedded-cbor<ext-data-bundle-age>>
ext-data-bundle-age = uint

; Hop Count extension block
$extension-block /=
  extension-block-use<10, embedded-cbor<ext-data-hop-count>>
ext-data-hop-count = [
  hop-limit: uint,
  hop-count: uint
]