PR feedbacks

- Move exceptions to exceptions.py
- Raise `UpgradeFailure` in upgrader
- Refine the try/catch for upgraders in swarm

libp2p/transport/exceptions.py

@@ -10,5 +10,9 @@ class SecurityUpgradeFailure(UpgradeFailure):
     pass
 
 
+class MuxerUpgradeFailure(UpgradeFailure):
+    pass
+
+
 class HandshakeFailure(BaseLibp2pError):
     pass

libp2p/transport/upgrader.py

@@ -3,11 +3,17 @@ from typing import Mapping
 from libp2p.network.connection.raw_connection_interface import IRawConnection
 from libp2p.network.typing import GenericProtocolHandlerFn
 from libp2p.peer.id import ID
+from libp2p.protocol_muxer.exceptions import MultiselectClientError, MultiselectError
 from libp2p.security.secure_conn_interface import ISecureConn
 from libp2p.security.secure_transport_interface import ISecureTransport
 from libp2p.security.security_multistream import SecurityMultistream
 from libp2p.stream_muxer.abc import IMuxedConn
 from libp2p.stream_muxer.muxer_multistream import MuxerClassType, MuxerMultistream
+from libp2p.transport.exceptions import (
+    HandshakeFailure,
+    MuxerUpgradeFailure,
+    SecurityUpgradeFailure,
+)
 from libp2p.typing import TProtocol
 
 from .listener_interface import IListener
@@ -39,10 +45,20 @@ class TransportUpgrader:
         """
         Upgrade conn to a secured connection
         """
-        if initiator:
-            return await self.security_multistream.secure_outbound(raw_conn, peer_id)
-
-        return await self.security_multistream.secure_inbound(raw_conn)
+        try:
+            if initiator:
+                return await self.security_multistream.secure_outbound(
+                    raw_conn, peer_id
+                )
+            return await self.security_multistream.secure_inbound(raw_conn)
+        except (MultiselectError, MultiselectClientError) as error:
+            raise SecurityUpgradeFailure(
+                "failed to negotiate the secure protocol"
+            ) from error
+        except HandshakeFailure as error:
+            raise SecurityUpgradeFailure(
+                "handshake failed when upgrading to secure connection"
+            ) from error
 
     async def upgrade_connection(
         self,
@@ -53,6 +69,11 @@ class TransportUpgrader:
         """
         Upgrade secured connection to a muxed connection
         """
-        return await self.muxer_multistream.new_conn(
-            conn, generic_protocol_handler, peer_id
-        )
+        try:
+            return await self.muxer_multistream.new_conn(
+                conn, generic_protocol_handler, peer_id
+            )
+        except (MultiselectError, MultiselectClientError) as error:
+            raise MuxerUpgradeFailure(
+                "failed to negotiate the multiplexer protocol"
+            ) from error