enforced f-strings everywhere, %s on logging

extended _multiaddr_from_socket to support UDP and IPv6 automatically
changed TCPListener to use _ip4_or_6_from_multiaddr to get host, and not ip4 only

enforced `from error` everywhere with raises
added call braces to exceptions

libp2p/crypto/ecc.py

@@ -32,7 +32,7 @@ class ECCPublicKey(PublicKey):
         return KeyType.ECC_P256
 
     def verify(self, data: bytes, signature: bytes) -> bool:
-        raise NotImplementedError
+        raise NotImplementedError()
 
 
 class ECCPrivateKey(PrivateKey):
@@ -53,7 +53,7 @@ class ECCPrivateKey(PrivateKey):
         return KeyType.ECC_P256
 
     def sign(self, data: bytes) -> bytes:
-        raise NotImplementedError
+        raise NotImplementedError()
 
     def get_public_key(self) -> PublicKey:
         public_key_impl = keys.get_public_key(self.impl, self.curve)

libp2p/crypto/serialization.py

@@ -20,8 +20,10 @@ def deserialize_public_key(data: bytes) -> PublicKey:
     f = PublicKey.deserialize_from_protobuf(data)
     try:
         deserializer = key_type_to_public_key_deserializer[f.key_type]
-    except KeyError:
+    except KeyError as e:
-        raise MissingDeserializerError({"key_type": f.key_type, "key": "public_key"})
+        raise MissingDeserializerError(
+            {"key_type": f.key_type, "key": "public_key"}
+        ) from e
     return deserializer(f.data)
 
 
@@ -29,6 +31,8 @@ def deserialize_private_key(data: bytes) -> PrivateKey:
     f = PrivateKey.deserialize_from_protobuf(data)
     try:
         deserializer = key_type_to_private_key_deserializer[f.key_type]
-    except KeyError:
+    except KeyError as e:
-        raise MissingDeserializerError({"key_type": f.key_type, "key": "private_key"})
+        raise MissingDeserializerError(
+            {"key_type": f.key_type, "key": "private_key"}
+        ) from e
     return deserializer(f.data)

libp2p/host/basic_host.py

@@ -93,7 +93,7 @@ class BasicHost(IHost):
         :return: all the multiaddr addresses this host is listening to
         """
         # TODO: We don't need "/p2p/{peer_id}" postfix actually.
-        p2p_part = multiaddr.Multiaddr("/p2p/{}".format(self.get_id().pretty()))
+        p2p_part = multiaddr.Multiaddr(f"/p2p/{self.get_id()!s}")
 
         addrs: List[multiaddr.Multiaddr] = []
         for transport in self._network.listeners.values():
@@ -131,7 +131,7 @@ class BasicHost(IHost):
         except MultiselectClientError as error:
             logger.debug("fail to open a stream to peer %s, error=%s", peer_id, error)
             await net_stream.reset()
-            raise StreamFailure("failt to open a stream to peer %s", peer_id) from error
+            raise StreamFailure(f"failed to open a stream to peer {peer_id}") from error
 
         net_stream.set_protocol(selected_protocol)
         return net_stream

libp2p/network/connection/raw_connection.py

@@ -29,7 +29,7 @@ class RawConnection(IRawConnection):
         try:
             self.writer.write(data)
         except ConnectionResetError as error:
-            raise RawConnError(error)
+            raise RawConnError() from error
         # Reference: https://github.com/ethereum/lahja/blob/93610b2eb46969ff1797e0748c7ac2595e130aef/lahja/asyncio/endpoint.py#L99-L102  # noqa: E501
         # Use a lock to serialize drain() calls. Circumvents this bug:
         # https://bugs.python.org/issue29930
@@ -37,7 +37,7 @@ class RawConnection(IRawConnection):
             try:
                 await self.writer.drain()
             except ConnectionResetError as error:
-                raise RawConnError(error)
+                raise RawConnError() from error
 
     async def read(self, n: int = -1) -> bytes:
         """
@@ -49,7 +49,7 @@ class RawConnection(IRawConnection):
         try:
             return await self.reader.read(n)
         except ConnectionResetError as error:
-            raise RawConnError(error)
+            raise RawConnError() from error
 
     async def close(self) -> None:
         self.writer.close()

libp2p/network/stream/net_stream.py

@@ -47,9 +47,9 @@ class NetStream(INetStream):
         try:
             return await self.muxed_stream.read(n)
         except MuxedStreamEOF as error:
-            raise StreamEOF from error
+            raise StreamEOF() from error
         except MuxedStreamReset as error:
-            raise StreamReset from error
+            raise StreamReset() from error
 
     async def write(self, data: bytes) -> int:
         """
@@ -60,7 +60,7 @@ class NetStream(INetStream):
         try:
             return await self.muxed_stream.write(data)
         except MuxedStreamClosed as error:
-            raise StreamClosed from error
+            raise StreamClosed() from error
 
     async def close(self) -> None:
         """close stream."""

libp2p/network/swarm.py

@@ -87,8 +87,8 @@ class Swarm(INetwork):
         try:
             # Get peer info from peer store
             addrs = self.peerstore.addrs(peer_id)
-        except PeerStoreError:
+        except PeerStoreError as e:
-            raise SwarmException(f"No known addresses to peer {peer_id}")
+            raise SwarmException(f"No known addresses to peer {peer_id}") from e
 
         if not addrs:
             raise SwarmException(f"No known addresses to peer {peer_id}")
@@ -101,7 +101,7 @@ class Swarm(INetwork):
         except OpenConnectionError as error:
             logger.debug("fail to dial peer %s over base transport", peer_id)
             raise SwarmException(
-                "fail to open connection to peer %s", peer_id
+                f"fail to open connection to peer {peer_id}"
             ) from error
 
         logger.debug("dialed peer %s over base transport", peer_id)
@@ -111,20 +111,20 @@ class Swarm(INetwork):
         try:
             secured_conn = await self.upgrader.upgrade_security(raw_conn, peer_id, True)
         except SecurityUpgradeFailure as error:
-            error_msg = "fail to upgrade security for peer %s"
+            logger.debug("failed to upgrade security for peer %s", peer_id)
-            logger.debug(error_msg, peer_id)
             await raw_conn.close()
-            raise SwarmException(error_msg % peer_id) from error  # wip
+            raise SwarmException(
+                f"failed to upgrade security for peer {peer_id}"
+            ) from error
 
         logger.debug("upgraded security for peer %s", peer_id)
 
         try:
             muxed_conn = await self.upgrader.upgrade_connection(secured_conn, peer_id)
         except MuxerUpgradeFailure as error:
-            error_msg = "fail to upgrade mux for peer %s"
+            logger.debug("failed to upgrade mux for peer %s", peer_id)
-            logger.debug(error_msg, peer_id)
             await secured_conn.close()
-            raise SwarmException(error_msg % peer_id) from error  # wip
+            raise SwarmException(f"failed to upgrade mux for peer {peer_id}") from error
 
         logger.debug("upgraded mux for peer %s", peer_id)
 
@@ -187,10 +187,11 @@ class Swarm(INetwork):
                         raw_conn, ID(b""), False
                     )
                 except SecurityUpgradeFailure as error:
-                    error_msg = "fail to upgrade security for peer at %s"
+                    logger.debug("failed to upgrade security for peer at %s", peer_addr)
-                    logger.debug(error_msg, peer_addr)
                     await raw_conn.close()
-                    raise SwarmException(error_msg % peer_addr) from error  # wip
+                    raise SwarmException(
+                        f"failed to upgrade security for peer at {peer_addr}"
+                    ) from error
                 peer_id = secured_conn.get_remote_peer()
 
                 logger.debug("upgraded security for peer at %s", peer_addr)
@@ -201,10 +202,11 @@ class Swarm(INetwork):
                         secured_conn, peer_id
                     )
                 except MuxerUpgradeFailure as error:
-                    error_msg = "fail to upgrade mux for peer %s"
+                    logger.debug("fail to upgrade mux for peer %s", peer_id)
-                    logger.debug(error_msg, peer_id)
                     await secured_conn.close()
-                    raise SwarmException(error_msg % peer_id) from error  # wip
+                    raise SwarmException(
+                        f"fail to upgrade mux for peer {peer_id}"
+                    ) from error
                 logger.debug("upgraded mux for peer %s", peer_id)
 
                 await self.add_conn(muxed_conn)
@@ -223,7 +225,7 @@ class Swarm(INetwork):
                 return True
             except IOError:
                 # Failed. Continue looping.
-                logger.debug("fail to listen on: " + str(maddr))
+                logger.debug("fail to listen on: %s", maddr)
 
         # No maddr succeeded
         return False

libp2p/peer/peerstore.py

@@ -71,7 +71,7 @@ class PeerStore(IPeerStore):
             try:
                 val = self.peer_data_map[peer_id].get_metadata(key)
             except PeerDataError as error:
-                raise PeerStoreError(error)
+                raise PeerStoreError() from error
             return val
         raise PeerStoreError("peer ID not found")
 
@@ -153,8 +153,8 @@ class PeerStore(IPeerStore):
             peer_data = self.peer_data_map[peer_id]
             try:
                 pubkey = peer_data.get_pubkey()
-            except PeerDataError:
+            except PeerDataError as e:
-                raise PeerStoreError("peer pubkey not found")
+                raise PeerStoreError("peer pubkey not found") from e
             return pubkey
         raise PeerStoreError("peer ID not found")
 
@@ -179,8 +179,8 @@ class PeerStore(IPeerStore):
             peer_data = self.peer_data_map[peer_id]
             try:
                 privkey = peer_data.get_privkey()
-            except PeerDataError:
+            except PeerDataError as e:
-                raise PeerStoreError("peer privkey not found")
+                raise PeerStoreError("peer privkey not found") from e
             return privkey
         raise PeerStoreError("peer ID not found")
 

libp2p/protocol_muxer/multiselect.py

@@ -49,7 +49,7 @@ class Multiselect(IMultiselectMuxer):
             try:
                 command = await communicator.read()
             except MultiselectCommunicatorError as error:
-                raise MultiselectError(error)
+                raise MultiselectError() from error
 
             if command == "ls":
                 # TODO: handle ls command
@@ -60,13 +60,13 @@ class Multiselect(IMultiselectMuxer):
                     try:
                         await communicator.write(protocol)
                     except MultiselectCommunicatorError as error:
-                        raise MultiselectError(error)
+                        raise MultiselectError() from error
 
                     return protocol, self.handlers[protocol]
                 try:
                     await communicator.write(PROTOCOL_NOT_FOUND_MSG)
                 except MultiselectCommunicatorError as error:
-                    raise MultiselectError(error)
+                    raise MultiselectError() from error
 
     async def handshake(self, communicator: IMultiselectCommunicator) -> None:
         """
@@ -78,12 +78,12 @@ class Multiselect(IMultiselectMuxer):
         try:
             await communicator.write(MULTISELECT_PROTOCOL_ID)
         except MultiselectCommunicatorError as error:
-            raise MultiselectError(error)
+            raise MultiselectError() from error
 
         try:
             handshake_contents = await communicator.read()
         except MultiselectCommunicatorError as error:
-            raise MultiselectError(error)
+            raise MultiselectError() from error
 
         if not is_valid_handshake(handshake_contents):
             raise MultiselectError(

libp2p/protocol_muxer/multiselect_client.py

@@ -25,12 +25,12 @@ class MultiselectClient(IMultiselectClient):
         try:
             await communicator.write(MULTISELECT_PROTOCOL_ID)
         except MultiselectCommunicatorError as error:
-            raise MultiselectClientError(error)
+            raise MultiselectClientError() from error
 
         try:
             handshake_contents = await communicator.read()
         except MultiselectCommunicatorError as error:
-            raise MultiselectClientError(str(error))
+            raise MultiselectClientError() from error
 
         if not is_valid_handshake(handshake_contents):
             raise MultiselectClientError("multiselect protocol ID mismatch")
@@ -73,18 +73,18 @@ class MultiselectClient(IMultiselectClient):
         try:
             await communicator.write(protocol)
         except MultiselectCommunicatorError as error:
-            raise MultiselectClientError(error)
+            raise MultiselectClientError() from error
 
         try:
             response = await communicator.read()
         except MultiselectCommunicatorError as error:
-            raise MultiselectClientError(str(error))
+            raise MultiselectClientError() from error
 
         if response == protocol:
             return protocol
         if response == PROTOCOL_NOT_FOUND_MSG:
             raise MultiselectClientError("protocol not supported")
-        raise MultiselectClientError("unrecognized response: " + response)
+        raise MultiselectClientError(f"unrecognized response: {response}")
 
 
 def is_valid_handshake(handshake_contents: str) -> bool:

libp2p/security/insecure/transport.py

@@ -52,13 +52,13 @@ class InsecureSession(BaseSession):
         encoded_msg_bytes = encode_fixedint_prefixed(msg_bytes)
         try:
             await self.write(encoded_msg_bytes)
-        except RawConnError:
+        except RawConnError as e:
-            raise HandshakeFailure("connection closed")
+            raise HandshakeFailure("connection closed") from e
 
         try:
             remote_msg_bytes = await read_fixedint_prefixed(self.conn)
-        except RawConnError:
+        except RawConnError as e:
-            raise HandshakeFailure("connection closed")
+            raise HandshakeFailure("connection closed") from e
         remote_msg = plaintext_pb2.Exchange()
         remote_msg.ParseFromString(remote_msg_bytes)
         received_peer_id = ID(remote_msg.id)
@@ -77,12 +77,12 @@ class InsecureSession(BaseSession):
             received_pubkey = deserialize_public_key(
                 remote_msg.pubkey.SerializeToString()
             )
-        except ValueError:
+        except ValueError as e:
             raise HandshakeFailure(
                 f"unknown `key_type` of remote_msg.pubkey={remote_msg.pubkey}"
-            )
+            ) from e
         except MissingDeserializerError as error:
-            raise HandshakeFailure(error)
+            raise HandshakeFailure() from error
         peer_id_from_received_pubkey = ID.from_pubkey(received_pubkey)
         if peer_id_from_received_pubkey != received_peer_id:
             raise HandshakeFailure(

libp2p/security/secio/transport.py

@@ -131,8 +131,8 @@ class SecureSession(BaseSession):
         msg = await self.conn.read_msg()
         try:
             decrypted_msg = self.remote_encrypter.decrypt_if_valid(msg)
-        except InvalidMACException:
+        except InvalidMACException as e:
-            raise DecryptionFailedException
+            raise DecryptionFailedException() from e
         return decrypted_msg
 
     async def write(self, data: bytes) -> int:
@@ -175,7 +175,7 @@ class Proposal:
         try:
             public_key = deserialize_public_key(public_key_protobuf_bytes)
         except MissingDeserializerError as error:
-            raise SedesException(error)
+            raise SedesException() from error
         exchanges = protobuf.exchanges
         ciphers = protobuf.ciphers
         hashes = protobuf.hashes
@@ -424,8 +424,8 @@ async def create_secure_session(
         await conn.close()
         raise e
     # `IOException` includes errors raised while read from/write to raw connection
-    except IOException:
+    except IOException as e:
-        raise SecioException("connection closed")
+        raise SecioException("connection closed") from e
 
     is_initiator = remote_peer is not None
     session = _mk_session_from(
@@ -435,8 +435,8 @@ async def create_secure_session(
     try:
         received_nonce = await _finish_handshake(session, remote_nonce)
     # `IOException` includes errors raised while read from/write to raw connection
-    except IOException:
+    except IOException as e:
-        raise SecioException("connection closed")
+        raise SecioException("connection closed") from e
     if received_nonce != local_nonce:
         await conn.close()
         raise InconsistentNonce()

libp2p/stream_muxer/mplex/mplex_stream.py

@@ -75,7 +75,7 @@ class MplexStream(IMuxedStream):
 
         if task_event_reset in done:
             if self.event_reset.is_set():
-                raise MplexStreamReset
+                raise MplexStreamReset()
             else:
                 # However, it is abnormal that `Event.wait` is unblocked without any of the flag
                 #   is set. The task is probably cancelled.
@@ -91,7 +91,7 @@ class MplexStream(IMuxedStream):
 
         if task_event_remote_closed in done:
             if self.event_remote_closed.is_set():
-                raise MplexStreamEOF
+                raise MplexStreamEOF()
             else:
                 # However, it is abnormal that `Event.wait` is unblocked without any of the flag
                 #   is set. The task is probably cancelled.
@@ -126,7 +126,7 @@ class MplexStream(IMuxedStream):
                 f"the number of bytes to read `n` must be positive or -1 to indicate read until EOF"
             )
         if self.event_reset.is_set():
-            raise MplexStreamReset
+            raise MplexStreamReset()
         if n == -1:
             return await self._read_until_eof()
         if len(self._buf) == 0 and self.incoming_data.empty():

libp2p/tools/interop/daemon.py

@@ -56,7 +56,7 @@ class P2PDProcess:
         is_pubsub_signing: bool = False,
         is_pubsub_signing_strict: bool = False,
     ) -> None:
-        args = [f"-listen={str(control_maddr)}"]
+        args = [f"-listen={control_maddr!s}"]
         # NOTE: To support `-insecure`, we need to hack `go-libp2p-daemon`.
         if not is_secure:
             args.append("-insecure=true")

libp2p/tools/pubsub/dummy_account_node.py

@@ -81,7 +81,7 @@ class DummyAccountNode:
         :param dest_user: user to send crypto to
         :param amount: amount of crypto to send
         """
-        msg_contents = "send," + source_user + "," + dest_user + "," + str(amount)
+        msg_contents = f"send,{source_user},{dest_user},{amount!s}"
         await self.pubsub.publish(CRYPTO_TOPIC, msg_contents.encode())
 
     async def publish_set_crypto(self, user: str, amount: int) -> None:
@@ -92,7 +92,7 @@ class DummyAccountNode:
         :param user: user to set crypto for
         :param amount: amount of crypto
         """
-        msg_contents = "set," + user + "," + str(amount)
+        msg_contents = f"set,{user},{amount!s}"
         await self.pubsub.publish(CRYPTO_TOPIC, msg_contents.encode())
 
     def handle_send_crypto(self, source_user: str, dest_user: str, amount: int) -> None:

libp2p/tools/utils.py

@@ -51,7 +51,7 @@ async def echo_stream_handler(stream: INetStream) -> None:
     while True:
         read_string = (await stream.read(MAX_READ_LEN)).decode()
 
-        resp = "ack:" + read_string
+        resp = f"ack:{read_string}"
         await stream.write(resp.encode())
 
 

libp2p/transport/tcp/tcp.py

@@ -1,9 +1,11 @@
 import asyncio
-from socket import socket
+import socket
 import sys
-from typing import List
+from typing import List, Optional
 
 from multiaddr import Multiaddr
+from multiaddr.protocols import P_IP4, P_IP6, P_TCP, P_UDP
+from multiaddr.protocols import protocol_with_code as p_code
 
 from libp2p.network.connection.raw_connection import RawConnection
 from libp2p.network.connection.raw_connection_interface import IRawConnection
@@ -29,10 +31,14 @@ class TCPListener(IListener):
         :param maddr: maddr of peer
         :return: return True if successful
         """
+        listen_addr = _ip4_or_6_from_multiaddr(maddr)
+        if listen_addr is None:
+            raise NotImplementedError(
+                "Can only start TCP Listener with a IPv4 or IPv6 address"
+            )
+
         self.server = await asyncio.start_server(
-            self.handler,
+            self.handler, listen_addr, maddr.value_for_protocol("tcp")
-            maddr.value_for_protocol("ip4"),
-            maddr.value_for_protocol("tcp"),
         )
         socket = self.server.sockets[0]
         self.multiaddrs.append(_multiaddr_from_socket(socket))
@@ -70,7 +76,10 @@ class TCP(ITransport):
         :return: `RawConnection` if successful
         :raise OpenConnectionError: raised when failed to open connection
         """
-        self.host = maddr.value_for_protocol("ip4")
+        self.host = _ip4_or_6_from_multiaddr(maddr)
+        if self.host is None:
+            raise ValueError("Cannot find ipv4 or ipv6 host in multiaddress")
+
         self.port = int(maddr.value_for_protocol("tcp"))
 
         try:
@@ -91,5 +100,52 @@ class TCP(ITransport):
         return TCPListener(handler_function)
 
 
-def _multiaddr_from_socket(socket: socket) -> Multiaddr:
+def _ip4_or_6_from_multiaddr(maddr: Multiaddr) -> Optional[str]:
-    return Multiaddr("/ip4/%s/tcp/%s" % socket.getsockname())  # wip
+    if P_IP4 in maddr.protocols():
+        return maddr.value_for_protocol(P_IP4)
+    elif P_IP6 in maddr.protocols():
+        return maddr.value_for_protocol(P_IP6)
+    else:
+        return None
+
+
+def _multiaddr_from_socket(sock: socket.socket) -> Multiaddr:
+    # Reference: http://man7.org/linux/man-pages/man2/socket.2.html#DESCRIPTION
+    # todo: move this to more generic libp2p.transport helper function
+
+    # Reference: https://stackoverflow.com/questions/5815675/what-is-sock-dgram-and-sock-stream
+    # Selects first protocol in sequence if bitwise AND matches, else None
+    t_proto = next(
+        (
+            v
+            for k, v in {
+                socket.SOCK_STREAM: p_code(P_TCP).name,
+                socket.SOCK_DGRAM: p_code(P_UDP).name,
+            }.items()
+            if k & sock.type != 0
+        ),
+        None,
+    )
+
+    if t_proto is None:
+        raise NotImplementedError(
+            f"Cannot convert socket to multiaddr, socket type is of {sock.type}"
+        )
+
+    # Reference: https://docs.python.org/3/library/socket.html#socket-families
+    if sock.family == socket.AF_INET:
+        # ipv4: (host, port)
+        addr, port = sock.getsockname()
+        ip = p_code(P_IP4).name
+
+    elif sock.family == socket.AF_INET6:
+        # ipv6: (host, port, flowinfo, scopeid)
+        addr, port = sock.getsockname()[:2]
+        ip = p_code(P_IP6).name
+
+    else:
+        raise NotImplementedError(
+            f"Cannot convert socket to multiaddr, socket family is of {sock.family}"
+        )
+
+    return Multiaddr(f"/{ip}/{addr}/{t_proto}/{port}")