don't crash on unknown disconnection reason, fix disconnection reason enum (#1208)

beacon_chain/eth2_network.nim

@@ -144,9 +144,10 @@ type
   MessageContentPrinter* = proc(msg: pointer): string {.gcsafe.}
 
   DisconnectionReason* = enum
-    ClientShutDown
-    IrrelevantNetwork
-    FaultOrError
+    # might see other values on the wire!
+    ClientShutDown = 1
+    IrrelevantNetwork = 2
+    FaultOrError = 3
 
   PeerDisconnected* = object of CatchableError
     reason*: DisconnectionReason

beacon_chain/ssz/spec_types.nim

@@ -10,7 +10,9 @@ template toSszType*(x: auto): auto =
   # Please note that BitArray doesn't need any special treatment here
   # because it can be considered a regular fixed-size object type.
 
-  when x is Slot|Epoch|ValidatorIndex|enum: uint64(x)
+  # enum should not be added here as nim will raise Defect when value is out
+  # of range
+  when x is Slot|Epoch|ValidatorIndex: uint64(x)
   elif x is Eth2Digest: x.data
   elif x is BlsCurveType: toRaw(x)
   elif x is ForkDigest|Version: distinctBase(x)

beacon_chain/sync_protocol.nim

@@ -59,6 +59,13 @@ proc shortLog*(s: StatusMsg): auto =
   )
 chronicles.formatIt(StatusMsg): shortLog(it)
 
+func disconnectReasonName(reason: uint64): string =
+  # haha, nim doesn't support uint64 in `case`!
+  if reason == uint64(ClientShutDown): "Client shutdown"
+  elif reason == uint64(IrrelevantNetwork): "Irrelevant network"
+  elif reason == uint64(FaultOrError): "Fault or error"
+  else: "Disconnected (" & $reason & ")"
+
 proc importBlocks(state: BeaconSyncNetworkState,
                   blocks: openarray[SignedBeaconBlock]) {.gcsafe.} =
   for blk in blocks:
@@ -169,9 +176,9 @@ p2pProtocol BeaconSync(version = 1,
       peer, roots = blockRoots.len, count, found
 
   proc goodbye(peer: Peer,
-               reason: DisconnectionReason)
+               reason: uint64)
     {.async, libp2pProtocol("goodbye", 1).} =
-    debug "Received Goodbye message", reason, peer
+    debug "Received Goodbye message", reason = disconnectReasonName(reason), peer
 
 proc setStatusMsg(peer: Peer, statusMsg: StatusMsg) =
   debug "Peer status", peer, statusMsg

beacon_chain/sync_protocol.nim.generated.nim

@@ -1,5 +1,5 @@
 
-## Generated at line 87
+## Generated at line 94
 type
   BeaconSync* = object
 template State*(PROTO: type BeaconSync): type =
@@ -69,15 +69,15 @@ template RecType*(MSG: type beaconBlocksByRootObj): untyped =
   BlockRootsList
 
 type
-  goodbyeObj* = distinct DisconnectionReason
+  goodbyeObj* = distinct uint64
 template goodbye*(PROTO: type BeaconSync): type =
-  DisconnectionReason
+  uint64
 
 template msgProtocol*(MSG: type goodbyeObj): type =
   BeaconSync
 
 template RecType*(MSG: type goodbyeObj): untyped =
-  DisconnectionReason
+  uint64
 
 var BeaconSyncProtocolObj = initProtocol("BeaconSync", createPeerState[Peer,
     ref[BeaconSyncPeerState:ObjectType]], createNetworkState[Eth2Node,
@@ -136,7 +136,7 @@ proc beaconBlocksByRoot*(peer: Peer; blockRoots: BlockRootsList;
   makeEth2Request(peer, "/eth2/beacon_chain/req/beacon_blocks_by_root/1/",
                   msgBytes, seq[SignedBeaconBlock], timeout)
 
-proc goodbye*(peer: Peer; reason: DisconnectionReason): Future[void] {.gcsafe,
+proc goodbye*(peer: Peer; reason: uint64): Future[void] {.gcsafe,
     libp2pProtocol("goodbye", 1).} =
   var outputStream = memoryOutput()
   var writer = init(WriterType(SSZ), outputStream)
@@ -238,7 +238,7 @@ proc beaconBlocksByRootUserHandler(peer: Peer; blockRoots: BlockRootsList; respo
       inc found
   debug "Block root request done", peer, roots = blockRoots.len, count, found
 
-proc goodbyeUserHandler(peer: Peer; reason: DisconnectionReason) {.async,
+proc goodbyeUserHandler(peer: Peer; reason: uint64) {.async,
     libp2pProtocol("goodbye", 1), gcsafe.} =
   type
     CurrentProtocol = BeaconSync
@@ -249,7 +249,7 @@ proc goodbyeUserHandler(peer: Peer; reason: DisconnectionReason) {.async,
     cast[ref[BeaconSyncNetworkState:ObjectType]](getNetworkState(peer.network,
         BeaconSyncProtocol))
 
-  debug "Received Goodbye message", reason, peer
+  debug "Received Goodbye message", reason = disconnectReasonName(reason), peer
 
 template callUserHandler(MSG: type statusObj; peer: Peer; stream: Connection;
                         noSnappy: bool; msg: StatusMsg): untyped =
@@ -338,7 +338,7 @@ proc beaconBlocksByRootMounter(network: Eth2Node) =
       "ssz_snappy", handler: snappyThunk)
 
 template callUserHandler(MSG: type goodbyeObj; peer: Peer; stream: Connection;
-                        noSnappy: bool; msg: DisconnectionReason): untyped =
+                        noSnappy: bool; msg: uint64): untyped =
   goodbyeUserHandler(peer, msg)
 
 proc goodbyeMounter(network: Eth2Node) =