Checks against chain_id == 0 in TokenNetworkRegistry

raiden/network/proxies/token_network_registry.py

@@ -27,6 +27,7 @@
     TYPE_CHECKING,
     Address,
     BlockSpecification,
+    ChainID,
     Dict,
     T_TargetAddress,
     TokenAddress,
@@ -122,6 +123,7 @@ def add_token(
             already_registered = self.get_token_network(
                 token_address=token_address, block_identifier=block_identifier
             )
+            chain_id = self.get_chain_id(to_block=block_identifier)
         except ValueError:
             # If `block_identifier` has been pruned the checks cannot be performed
             pass
@@ -132,6 +134,13 @@ def add_token(
                 raise BrokenPreconditionError(
                     "The token is already registered in the TokenNetworkRegistry."
                 )
+            if chain_id == 0:
+                raise RaidenUnrecoverableError(
+                    "The TokenNetworkRegistry was deployed for chain_id == 0. "
+                    "But the constructor of TokenNetworkRegistry usually refuses this value. "
+                    "Moreover, the constructor of TokenNetwork will refuse this value."
+                    "Probably the node is talking to a wrong smart contract."
+                )
 
         return self._add_token(
             token_address=token_address,
@@ -211,6 +220,12 @@ def _add_token(
                 if self.get_token_network(token_address, block):
                     raise RaidenRecoverableError(f"{error_prefix}. Token already registered")
 
+                if self.get_chain_id(block) == 0:
+                    raise RaidenUnrecoverableError(
+                        f"{error_prefix}. TokenNetworkRegistry's chain_id changed. "
+                        "Probably the node is talking to a wrong smart contract."
+                    )
+
                 raise RaidenUnrecoverableError(error_prefix)
 
             token_network_address = self.get_token_network(token_address, "latest")
@@ -267,3 +282,7 @@ def get_max_token_networks(self, to_block: BlockSpecification) -> int:
         token network registry.
         """
         return self.proxy.contract.functions.max_token_networks().call(block_identifier=to_block)
+
+    def get_chain_id(self, to_block: BlockSpecification) -> ChainID:
+        """ Returns the value of chain_id stored in the TokenNetworkRegistry contract """
+        return ChainID(self.proxy.contract.functions.chain_id().call(block_identifier=to_block))

raiden/tests/integration/network/proxies/test_token_network_registry.py

@@ -132,3 +132,21 @@ def test_token_network_registry_max_token_networks(
         blockchain_service=blockchain_service,
     )
     assert token_network_registry_proxy.get_max_token_networks(to_block="latest") == UINT256_MAX
+
+
+def test_token_network_registry_chain_id(
+    deploy_client, token_network_registry_address, contract_manager
+):
+    """ get_chain_id() should return the chain ID """
+    blockchain_service = BlockChainService(
+        jsonrpc_client=deploy_client, contract_manager=contract_manager
+    )
+    token_network_registry_proxy = TokenNetworkRegistry(
+        jsonrpc_client=deploy_client,
+        registry_address=to_canonical_address(token_network_registry_address),
+        contract_manager=contract_manager,
+        blockchain_service=blockchain_service,
+    )
+    assert token_network_registry_proxy.get_chain_id(to_block="latest") == int(
+        deploy_client.web3.version.network
+    )