def make(circ_id,
stream_id,
reason=DEF.REASON_DONE,
reason_data='',
link_version=3):
'''Construct and return a RelayEnd cell, using default values where
possible.
Create a FixedLenCell.Header and a RelayCell.RelayHeader.
:param int circ_id: Circuit ID to use in this cell
:param int stream_id: Stream ID to use in this cell
:param int reason: Single byte that describes the reason this stream
was closed
:param str reason_data: with REASON_EXITPOLICY, this optional field
may be filled in
:returns: :class:`~oppy.cell.relay.RelayEndCell`
'''
h = FixedLenCell.Header(circ_id=circ_id,
cmd=DEF.RELAY_CMD,
link_version=link_version)
r = RelayCell.RelayHeader(cmd=DEF.RELAY_END_CMD,
recognized=DEF.RECOGNIZED,
stream_id=stream_id,
digest=DEF.EMPTY_DIGEST,
rpayload_len=REASON_SIZE + len(reason_data))
return RelayEndCell(h,
rheader=r,
reason=reason,
reason_data=reason_data)
def make(circ_id, reason=TRUNCATE_REASON, link_version=3):
"""TODO"""
h = FixedLenCell.Header(circ_id=circ_id,
cmd=DEF.RELAY_CMD,
link_version=link_version)
r = RelayCell.RelayHeader(cmd=DEF.RELAY_TRUNCATE_CMD,
recognized=DEF.RECOGNIZED,
stream_id=TRUNCATE_STREAM_ID,
digest=DEF.EMPTY_DIGEST,
rpayload_len=TRUNCATE_RPAYLOAD_LEN)
return RelayTruncateCell(h, r, reason)
def make(circ_id, stream_id, request, flags=None, link_version=3):
'''Build and return a RelayBegin cell, filling in default values
when possible.
Automatically create a default FixedLenCell.Header and
RelayCell.RelayHeader.
:param int circ_id: Circuit ID to use in this cell
:param int stream_id: Stream ID to use in this cell
:param oppy.util.ExitRequest request: destination this
cell will request a connection to
:param list, int flags: flags to use for this connection
:param int link_version: Link Protocol version in use on this
connection
:returns: :class:`~cell.relay.RelayBeginCell`
'''
addr = str(request)
if flags is None:
flags = [DEF.BEGIN_FLAG_IPv6_OK]
f = 0
for flag in flags:
if flag not in DEF.RELAY_BEGIN_FLAGS:
msg = 'Unrecognized Relay Begin flag: {}'.format(flag)
raise BadPayloadData(msg)
f |= (1 << (flag - 1))
flags = struct.pack('!I', f)
h = FixedLenCell.Header(circ_id=circ_id,
cmd=DEF.RELAY_CMD,
link_version=link_version)
r = RelayCell.RelayHeader(cmd=DEF.RELAY_BEGIN_CMD,
recognized=DEF.RECOGNIZED,
stream_id=stream_id,
digest=DEF.EMPTY_DIGEST,
rpayload_len=len(addr + flags))
return RelayBeginCell(h, rheader=r, addr=addr, flags=flags)
def make(circ_id, stream_id, rpayload, link_version=3):
'''Construct and return a RelayData cell, using default values
where possible.
Create a FixedLenCell.Header and a RelayCell.RelayHeader.
:param int circ_id: Circuit ID to use in this cell
:param int stream_id: Stream ID to use in this cell
:param str rpayload: data to use as the relay payload
:param int link_version: Link Protocol version in use
'''
if len(rpayload) > DEF.MAX_RPAYLOAD_LEN:
raise BadPayloadData()
h = FixedLenCell.Header(circ_id=circ_id,
cmd=DEF.RELAY_CMD,
link_version=link_version)
r = RelayCell.RelayHeader(cmd=DEF.RELAY_DATA_CMD,
recognized=DEF.RECOGNIZED,
stream_id=stream_id,
digest=DEF.EMPTY_DIGEST,
rpayload_len=len(rpayload))
return RelayDataCell(h, rheader=r, rpayload=rpayload)
def make(circ_id, stream_id=0, link_version=3):
'''Construct and return a RelaySendMeCell, using default values
where possible.
Create a FixedLenCell.Header and a RelayCell.RelayHeader for use
in this cell.
:param int circ_id: Circuit ID to use in this cell
:param int stream_id: Stream ID to use in this cell. A Stream ID of
zero indicates a 'circuit-level' SendMe cell, and a non-zero
Stream ID indicates a 'stream-level' SendMe cell.
:param int link_version: Link Protocol version in use
:returns: :class:`~oppy.cell.relay.RelaySendMeCell`
'''
h = FixedLenCell.Header(circ_id=circ_id,
cmd=DEF.RELAY_CMD,
link_version=link_version)
r = RelayCell.RelayHeader(cmd=DEF.RELAY_SENDME_CMD,
recognized=DEF.RECOGNIZED,
stream_id=stream_id,
digest=DEF.EMPTY_DIGEST,
rpayload_len=0)
return RelaySendMeCell(h, r)
def make(circ_id,
stream_id=0,
nspec=None,
lspecs=None,
htype=DEF.NTOR_HTYPE,
hlen=DEF.NTOR_HLEN,
hdata='',
link_version=3,
early=True):
'''Construct and return a RelayExtend2Cell, using default values where
possible.
Create a FixedLenCell.Header and a RelayCell.RelayHeader for use
in this cell.
.. note:: oppy currently only supports the NTor handshake and will
reject unrecognized htype's and hlen's.
:param int circ_id: Circuit ID to use in this cell
:param int stream_id: Stream ID to use in this cell (should be zero)
:param int nspec: the number of Link Specifiers in this cell
:param list, oppy.cell.util.LinkSpecifier lspecs: list of
Link Specifiers to include in this cell
:param int htype: Type of handshake in use
:param int hlen: length of the handshake data field
:param str hdata: handshake data (*onion skin*)
:param int link_version: Link Protocol version in use
:param bool early: if **True**, use a RELAY_EARLY cmd instead of
RELAY cmd
:returns: :class:`~oppy.cell.relay.RelayExtend2Cell`
'''
if lspecs is None:
lspecs = []
if stream_id != 0:
msg = "EXTEND2 cells should use stream_id=0."
raise BadPayloadData(msg)
if htype != DEF.NTOR_HTYPE:
msg = 'htype was {}, but we currently only support '
msg += '{} (NTor) handshakes.'
msg = msg.format(htype, DEF.NTOR_HTYPE)
raise BadPayloadData(msg)
if hlen != DEF.NTOR_HLEN:
msg = 'htype was NTor and hlen was {} but expecting {}'
msg = msg.format(hlen, DEF.NTOR_HLEN)
raise BadPayloadData(msg)
if hlen != len(hdata):
msg = 'hlen {} neq len(hdata) {}'.format(hlen, len(hdata))
raise BadPayloadData(msg)
cmd = DEF.RELAY_EARLY_CMD if early is True else DEF.RELAY_CMD
h = FixedLenCell.Header(circ_id=circ_id,
cmd=cmd,
link_version=link_version)
if nspec is None:
nspec = len(lspecs)
if len(lspecs) == 0:
msg = 'No Link Specifiers found. At least 1 Link Specifier '
msg += 'is required.'
raise BadPayloadData(msg)
if nspec != len(lspecs):
msg = 'Expected {} LinkSpecifiers but found {}'
msg = msg.format(nspec, len(lspecs))
raise BadPayloadData(msg)
rpayload_len = NSPEC_LEN
for lspec in lspecs:
rpayload_len += len(lspec)
rpayload_len += HTYPE_LEN + HLEN_LEN + hlen
r = RelayCell.RelayHeader(cmd=DEF.RELAY_EXTEND2_CMD,
recognized=DEF.RECOGNIZED,
stream_id=stream_id,
digest=DEF.EMPTY_DIGEST,
rpayload_len=rpayload_len)
return RelayExtend2Cell(h,
rheader=r,
nspec=nspec,
lspecs=lspecs,
htype=htype,
hlen=hlen,
hdata=hdata)
