mirror of
https://github.com/LBRYFoundation/LBRY-Vault.git
synced 2025-08-23 17:47:31 +00:00
3a73f6ee5c
Will be useful for TLVs where it makes sense to do the conversion in lnmsg, as it might be more complicated than just int.from_bytes().
235 lines
9.3 KiB
Python
235 lines
9.3 KiB
Python
import os
|
|
import csv
|
|
import io
|
|
from typing import Callable, Tuple, Any, Dict, List, Sequence, Union, Optional
|
|
|
|
|
|
class MalformedMsg(Exception):
|
|
pass
|
|
|
|
|
|
class UnknownMsgFieldType(MalformedMsg):
|
|
pass
|
|
|
|
|
|
class UnexpectedEndOfStream(MalformedMsg):
|
|
pass
|
|
|
|
|
|
def _assert_can_read_at_least_n_bytes(fd: io.BytesIO, n: int) -> None:
|
|
cur_pos = fd.tell()
|
|
end_pos = fd.seek(0, io.SEEK_END)
|
|
fd.seek(cur_pos)
|
|
if end_pos - cur_pos < n:
|
|
raise UnexpectedEndOfStream(f"cur_pos={cur_pos}. end_pos={end_pos}. wants to read: {n}")
|
|
|
|
|
|
def _read_field(*, fd: io.BytesIO, field_type: str, count: int) -> Union[bytes, int]:
|
|
if not fd: raise Exception()
|
|
assert isinstance(count, int) and count >= 0, f"{count!r} must be non-neg int"
|
|
if count == 0:
|
|
return b""
|
|
type_len = None
|
|
if field_type == 'byte':
|
|
type_len = 1
|
|
elif field_type == 'u16':
|
|
type_len = 2
|
|
assert count == 1, count
|
|
_assert_can_read_at_least_n_bytes(fd, type_len)
|
|
return int.from_bytes(fd.read(type_len), byteorder="big", signed=False)
|
|
elif field_type == 'u32':
|
|
type_len = 4
|
|
assert count == 1, count
|
|
_assert_can_read_at_least_n_bytes(fd, type_len)
|
|
return int.from_bytes(fd.read(type_len), byteorder="big", signed=False)
|
|
elif field_type == 'u64':
|
|
type_len = 8
|
|
assert count == 1, count
|
|
_assert_can_read_at_least_n_bytes(fd, type_len)
|
|
return int.from_bytes(fd.read(type_len), byteorder="big", signed=False)
|
|
# TODO tu16/tu32/tu64
|
|
elif field_type == 'chain_hash':
|
|
type_len = 32
|
|
elif field_type == 'channel_id':
|
|
type_len = 32
|
|
elif field_type == 'sha256':
|
|
type_len = 32
|
|
elif field_type == 'signature':
|
|
type_len = 64
|
|
elif field_type == 'point':
|
|
type_len = 33
|
|
elif field_type == 'short_channel_id':
|
|
type_len = 8
|
|
if type_len is None:
|
|
raise UnknownMsgFieldType(f"unexpected field type: {field_type!r}")
|
|
total_len = count * type_len
|
|
_assert_can_read_at_least_n_bytes(fd, total_len)
|
|
return fd.read(total_len)
|
|
|
|
|
|
def _write_field(*, fd: io.BytesIO, field_type: str, count: int,
|
|
value: Union[bytes, int]) -> None:
|
|
if not fd: raise Exception()
|
|
assert isinstance(count, int) and count >= 0, f"{count!r} must be non-neg int"
|
|
if count == 0:
|
|
return
|
|
type_len = None
|
|
if field_type == 'byte':
|
|
type_len = 1
|
|
elif field_type == 'u16':
|
|
type_len = 2
|
|
elif field_type == 'u32':
|
|
type_len = 4
|
|
elif field_type == 'u64':
|
|
type_len = 8
|
|
# TODO tu16/tu32/tu64
|
|
elif field_type == 'chain_hash':
|
|
type_len = 32
|
|
elif field_type == 'channel_id':
|
|
type_len = 32
|
|
elif field_type == 'sha256':
|
|
type_len = 32
|
|
elif field_type == 'signature':
|
|
type_len = 64
|
|
elif field_type == 'point':
|
|
type_len = 33
|
|
elif field_type == 'short_channel_id':
|
|
type_len = 8
|
|
if type_len is None:
|
|
raise UnknownMsgFieldType(f"unexpected fundamental type: {field_type!r}")
|
|
total_len = count * type_len
|
|
if isinstance(value, int) and (count == 1 or field_type == 'byte'):
|
|
value = int.to_bytes(value, length=total_len, byteorder="big", signed=False)
|
|
if not isinstance(value, (bytes, bytearray)):
|
|
raise Exception(f"can only write bytes into fd. got: {value!r}")
|
|
if total_len != len(value):
|
|
raise Exception(f"unexpected field size. expected: {total_len}, got {len(value)}")
|
|
nbytes_written = fd.write(value)
|
|
if nbytes_written != len(value):
|
|
raise Exception(f"tried to write {len(value)} bytes, but only wrote {nbytes_written}!?")
|
|
|
|
|
|
class LNSerializer:
|
|
def __init__(self):
|
|
self.msg_scheme_from_type = {} # type: Dict[bytes, List[Sequence[str]]]
|
|
self.msg_type_from_name = {} # type: Dict[str, bytes]
|
|
path = os.path.join(os.path.dirname(__file__), "lnwire", "peer_wire.csv")
|
|
with open(path, newline='') as f:
|
|
csvreader = csv.reader(f)
|
|
for row in csvreader:
|
|
#print(f">>> {row!r}")
|
|
if row[0] == "msgtype":
|
|
msg_type_name = row[1]
|
|
msg_type_int = int(row[2])
|
|
msg_type_bytes = msg_type_int.to_bytes(2, 'big')
|
|
assert msg_type_bytes not in self.msg_scheme_from_type, f"type collision? for {msg_type_name}"
|
|
assert msg_type_name not in self.msg_type_from_name, f"type collision? for {msg_type_name}"
|
|
row[2] = msg_type_int
|
|
self.msg_scheme_from_type[msg_type_bytes] = [tuple(row)]
|
|
self.msg_type_from_name[msg_type_name] = msg_type_bytes
|
|
elif row[0] == "msgdata":
|
|
assert msg_type_name == row[1]
|
|
self.msg_scheme_from_type[msg_type_bytes].append(tuple(row))
|
|
else:
|
|
pass # TODO
|
|
|
|
def encode_msg(self, msg_type: str, **kwargs) -> bytes:
|
|
"""
|
|
Encode kwargs into a Lightning message (bytes)
|
|
of the type given in the msg_type string
|
|
"""
|
|
#print(f">>> encode_msg. msg_type={msg_type}, payload={kwargs!r}")
|
|
msg_type_bytes = self.msg_type_from_name[msg_type]
|
|
scheme = self.msg_scheme_from_type[msg_type_bytes]
|
|
with io.BytesIO() as fd:
|
|
fd.write(msg_type_bytes)
|
|
for row in scheme:
|
|
if row[0] == "msgtype":
|
|
pass
|
|
elif row[0] == "msgdata":
|
|
field_name = row[2]
|
|
field_type = row[3]
|
|
field_count_str = row[4]
|
|
#print(f">>> encode_msg. msgdata. field_name={field_name!r}. field_type={field_type!r}. field_count_str={field_count_str!r}")
|
|
if field_count_str == "":
|
|
field_count = 1
|
|
else:
|
|
try:
|
|
field_count = int(field_count_str)
|
|
except ValueError:
|
|
field_count = kwargs[field_count_str]
|
|
if isinstance(field_count, (bytes, bytearray)):
|
|
field_count = int.from_bytes(field_count, byteorder="big")
|
|
assert isinstance(field_count, int)
|
|
try:
|
|
field_value = kwargs[field_name]
|
|
except KeyError:
|
|
if len(row) > 5:
|
|
break # optional feature field not present
|
|
else:
|
|
field_value = 0 # default mandatory fields to zero
|
|
#print(f">>> encode_msg. writing field: {field_name}. value={field_value!r}. field_type={field_type!r}. count={field_count!r}")
|
|
try:
|
|
_write_field(fd=fd,
|
|
field_type=field_type,
|
|
count=field_count,
|
|
value=field_value)
|
|
#print(f">>> encode_msg. so far: {fd.getvalue().hex()}")
|
|
except UnknownMsgFieldType as e:
|
|
pass # TODO
|
|
else:
|
|
pass # TODO
|
|
return fd.getvalue()
|
|
|
|
def decode_msg(self, data: bytes) -> Tuple[str, dict]:
|
|
"""
|
|
Decode Lightning message by reading the first
|
|
two bytes to determine message type.
|
|
|
|
Returns message type string and parsed message contents dict
|
|
"""
|
|
#print(f"decode_msg >>> {data.hex()}")
|
|
assert len(data) >= 2
|
|
msg_type_bytes = data[:2]
|
|
msg_type_int = int.from_bytes(msg_type_bytes, byteorder="big", signed=False)
|
|
scheme = self.msg_scheme_from_type[msg_type_bytes]
|
|
assert scheme[0][2] == msg_type_int
|
|
msg_type_name = scheme[0][1]
|
|
parsed = {}
|
|
with io.BytesIO(data[2:]) as fd:
|
|
for row in scheme:
|
|
#print(f"row: {row!r}")
|
|
if row[0] == "msgtype":
|
|
pass
|
|
elif row[0] == "msgdata":
|
|
field_name = row[2]
|
|
field_type = row[3]
|
|
field_count_str = row[4]
|
|
if field_count_str == "":
|
|
field_count = 1
|
|
else:
|
|
try:
|
|
field_count = int(field_count_str)
|
|
except ValueError:
|
|
field_count = parsed[field_count_str]
|
|
assert isinstance(field_count, int)
|
|
#print(f">> count={field_count}. parsed={parsed}")
|
|
try:
|
|
parsed[field_name] = _read_field(fd=fd,
|
|
field_type=field_type,
|
|
count=field_count)
|
|
except UnknownMsgFieldType as e:
|
|
pass # TODO
|
|
except UnexpectedEndOfStream as e:
|
|
if len(row) > 5:
|
|
break # optional feature field not present
|
|
else:
|
|
raise
|
|
else:
|
|
pass # TODO
|
|
return msg_type_name, parsed
|
|
|
|
|
|
_inst = LNSerializer()
|
|
encode_msg = _inst.encode_msg
|
|
decode_msg = _inst.decode_msg
|