Token network registry preconditions

raiden/app.py

@@ -101,9 +101,11 @@ def __init__(
         )
 
         # check that the settlement timeout fits the limits of the contract
+        settlement_timeout_min = default_registry.settlement_timeout_min("latest")
+        settlement_timeout_max = default_registry.settlement_timeout_max("latest")
         invalid_settle_timeout = (
-            config["settle_timeout"] < default_registry.settlement_timeout_min()
-            or config["settle_timeout"] > default_registry.settlement_timeout_max()
+            config["settle_timeout"] < settlement_timeout_min
+            or config["settle_timeout"] > settlement_timeout_max
             or config["settle_timeout"] < config["reveal_timeout"] * 2
         )
         if invalid_settle_timeout:
@@ -113,8 +115,8 @@ def __init__(
                     "be in range [{}, {}], is {}"
                 ).format(
                     to_checksum_address(default_registry.address),
-                    default_registry.settlement_timeout_min(),
-                    default_registry.settlement_timeout_max(),
+                    settlement_timeout_min,
+                    settlement_timeout_max,
                     config["settle_timeout"],
                 )
             )

raiden/exceptions.py

@@ -161,6 +161,18 @@ class InvalidTokenAddress(RaidenError):
     """ Raised if the token address is invalid """
 
 
+class InvalidTokenNetworkDepositLimit(RaidenError):
+    """ Raised when an invalid token network deposit
+    limit is passed to the token network registry proxy.
+    """
+
+
+class InvalidChannelParticipantDepositLimit(RaidenError):
+    """ Raised when an invalid channel participant
+    deposit limit is passed to the token network registry proxy.
+    """
+
+
 class STUNUnavailableException(RaidenError):
     pass