Allow for discv4 chronos strict usage

And group p2p tests that can be run with strict usage along the way.

eth.nimble

@@ -49,13 +49,11 @@ task test_discv4, "Run discovery v4 tests":
 task test_p2p, "Run p2p tests":
   test_discv5_task()
 
+  runTest("tests/p2p/all_tests")
+
+  # Code that still requires chronosStrict = false
   for filename in [
       "les/test_flow_control",
-      "test_auth",
-      "test_crypt",
-      "test_discovery",
-      "test_ecies",
-      "test_enode",
       "test_rlpx_thunk",
       "test_shh",
       "test_shh_config",

eth/p2p/discovery.nim

@@ -103,14 +103,14 @@ proc expiration(): uint32 =
 
 # Wire protocol
 
-proc send(d: DiscoveryProtocol, n: Node, data: seq[byte]) =
+proc send(d: DiscoveryProtocol, n: Node, data: seq[byte]) {.raises: [Defect].} =
   let ta = initTAddress(n.node.address.ip, n.node.address.udpPort)
   let f = d.transp.sendTo(ta, data)
   f.callback = proc(data: pointer) {.gcsafe.} =
     if f.failed:
       debug "Discovery send failed", msg = f.readError.msg
 
-proc sendPing*(d: DiscoveryProtocol, n: Node): seq[byte] =
+proc sendPing*(d: DiscoveryProtocol, n: Node): seq[byte] {.raises: [Defect].} =
   let payload = rlp.encode((PROTO_VERSION, d.address, n.node.address,
                             expiration()))
   let msg = pack(cmdPing, payload, d.privKey)
@@ -233,8 +233,8 @@ proc expirationValid(cmdId: CommandId, rlpEncodedPayload: openArray[byte]):
   else:
     raise newException(DiscProtocolError, "Invalid RLP list for this packet id")
 
-proc receive*(d: DiscoveryProtocol, a: Address, msg: openArray[byte]) {.gcsafe.} =
+proc receive*(d: DiscoveryProtocol, a: Address, msg: openArray[byte])
-  ## Can raise `DiscProtocolError` and all of `RlpError`
+    {.raises: [DiscProtocolError, RlpError, ValueError, Defect].} =
   # Note: export only needed for testing
   let msgHash = validateMsgHash(msg)
   if msgHash.isOk():
@@ -260,23 +260,23 @@ proc receive*(d: DiscoveryProtocol, a: Address, msg: openArray[byte]) {.gcsafe.}
   else:
     notice "Wrong msg mac from ", a
 
-proc processClient(transp: DatagramTransport,
+proc processClient(transp: DatagramTransport, raddr: TransportAddress):
-                   raddr: TransportAddress): Future[void] {.async, gcsafe.} =
+    Future[void] {.async, raises: [Defect].} =
   var proto = getUserData[DiscoveryProtocol](transp)
+  let buf = try: transp.getMessage()
+            except TransportOsError as e:
+              # This is likely to be local network connection issues.
+              warn "Transport getMessage", exception = e.name, msg = e.msg
+              return
+  let a = Address(ip: raddr.address, udpPort: raddr.port, tcpPort: raddr.port)
   try:
-    # TODO: Maybe here better to use `peekMessage()` to avoid allocation,
-    # but `Bytes` object is just a simple seq[byte], and `ByteRange` object
-    # do not support custom length.
-    var buf = transp.getMessage()
-    let a = Address(ip: raddr.address, udpPort: raddr.port, tcpPort: raddr.port)
     proto.receive(a, buf)
   except RlpError as e:
     debug "Receive failed", exc = e.name, err = e.msg
   except DiscProtocolError as e:
     debug "Receive failed", exc = e.name, err = e.msg
-  except Exception as e:
+  except ValueError as e:
     debug "Receive failed", exc = e.name, err = e.msg
-    raise e
 
 proc open*(d: DiscoveryProtocol) =
   # TODO allow binding to specific IP / IPv6 / etc

eth/p2p/kademlia.nim

@@ -26,7 +26,7 @@ type
     routing: RoutingTable
     pongFutures: Table[seq[byte], Future[bool]]
     pingFutures: Table[Node, Future[bool]]
-    neighboursCallbacks: Table[Node, proc(n: seq[Node]) {.gcsafe.}]
+    neighboursCallbacks: Table[Node, proc(n: seq[Node]) {.gcsafe, raises: [Defect].}]
     rng: ref BrHmacDrbgContext
 
   NodeId* = UInt256
@@ -255,7 +255,7 @@ proc updateRoutingTable(k: KademliaProtocol, n: Node) {.gcsafe.} =
       # replacement cache.
       asyncCheck k.bond(evictionCandidate)
 
-proc doSleep(p: proc() {.gcsafe.}) {.async, gcsafe.} =
+proc doSleep(p: proc() {.gcsafe, raises: [Defect].}) {.async, gcsafe.} =
   await sleepAsync(REQUEST_TIMEOUT)
   p()
 
@@ -276,7 +276,7 @@ proc waitPong(k: KademliaProtocol, n: Node, pingid: seq[byte]): Future[bool] =
       k.pongFutures.del(pingid)
       fut.complete(false)
 
-proc ping(k: KademliaProtocol, n: Node): seq[byte] =
+proc ping(k: KademliaProtocol, n: Node): seq[byte] {.raises: [Defect].} =
   doAssert(n != k.thisNode)
   result = k.wire.sendPing(n)
 
@@ -290,12 +290,13 @@ proc waitPing(k: KademliaProtocol, n: Node): Future[bool] {.gcsafe.} =
       k.pingFutures.del(n)
       fut.complete(false)
 
-proc waitNeighbours(k: KademliaProtocol, remote: Node): Future[seq[Node]] =
+proc waitNeighbours(k: KademliaProtocol, remote: Node):
+    Future[seq[Node]] {.raises: [Defect].} =
   doAssert(remote notin k.neighboursCallbacks)
   result = newFuture[seq[Node]]("waitNeighbours")
   let fut = result
   var neighbours = newSeqOfCap[Node](BUCKET_SIZE)
-  k.neighboursCallbacks[remote] = proc(n: seq[Node]) =
+  k.neighboursCallbacks[remote] = proc(n: seq[Node]) {.gcsafe, raises: [Defect].} =
     # This callback is expected to be called multiple times because nodes usually
     # split the neighbours replies into multiple packets, so we only complete the
     # future event.set() we've received enough neighbours.

tests/p2p/all_tests.nim

@@ -0,0 +1,6 @@
+import
+  ./test_auth,
+  ./test_crypt,
+  ./test_discovery,
+  ./test_ecies,
+  ./test_enode

tests/p2p/p2p_test_helper.nim

@@ -10,12 +10,6 @@ proc localAddress*(port: int): Address =
   result = Address(udpPort: port, tcpPort: port,
                    ip: parseIpAddress("127.0.0.1"))
 
-proc startDiscoveryNode*(privKey: PrivateKey, address: Address,
-                        bootnodes: seq[ENode]): Future[DiscoveryProtocol] {.async.} =
-  result = newDiscoveryProtocol(privKey, address, bootnodes)
-  result.open()
-  await result.bootstrap()
-
 proc setupTestNode*(
     rng: ref BrHmacDrbgContext,
     capabilities: varargs[ProtocolInfo, `protocolInfo`]): EthereumNode {.gcsafe.} =
@@ -27,13 +21,6 @@ proc setupTestNode*(
   for capability in capabilities:
     result.addCapability capability
 
-proc packData*(payload: openArray[byte], pk: PrivateKey): seq[byte] =
-  let
-    payloadSeq = @payload
-    signature = @(pk.sign(payload).toRaw())
-    msgHash = keccak256.digest(signature & payloadSeq)
-  result = @(msgHash.data) & signature & payloadSeq
-
 template sourceDir*: string = currentSourcePath.rsplit(DirSep, 1)[0]
 
 proc recvMsgMock*(msg: openArray[byte]): tuple[msgId: int, msgData: Rlp] =

tests/p2p/test_auth.nim

@@ -7,6 +7,8 @@
 #    distribution, for details about the copyright.
 #
 
+{.used.}
+
 import
   std/unittest,
   nimcrypto/[utils, keccak],

tests/p2p/test_crypt.nim

@@ -7,6 +7,8 @@
 #    distribution, for details about the copyright.
 #
 
+{.used.}
+
 import
   std/unittest,
   nimcrypto/[utils, sysrand, keccak],

tests/p2p/test_discovery.nim

@@ -7,119 +7,139 @@
 #    distribution, for details about the copyright.
 #
 
+{.used.}
+
 import
-  std/[sequtils, unittest],
+  std/sequtils,
-  chronos, stew/byteutils,
+  chronos, stew/byteutils, nimcrypto, testutils/unittests,
-  ../../eth/[keys, rlp], ../../eth/p2p/[discovery, kademlia, enode],
+  ../../eth/keys, ../../eth/p2p/[discovery, kademlia, enode]
-  ./p2p_test_helper
+
+proc localAddress(port: int): Address =
+  let port = Port(port)
+  result = Address(udpPort: port, tcpPort: port,
+                   ip: parseIpAddress("127.0.0.1"))
+
+proc initDiscoveryNode(privKey: PrivateKey, address: Address,
+                        bootnodes: seq[ENode]): DiscoveryProtocol =
+  let node = newDiscoveryProtocol(privKey, address, bootnodes)
+  node.open()
+
+  return node
+
+proc packData(payload: openArray[byte], pk: PrivateKey): seq[byte] =
+  let
+    payloadSeq = @payload
+    signature = @(pk.sign(payload).toRaw())
+    msgHash = keccak256.digest(signature & payloadSeq)
+  result = @(msgHash.data) & signature & payloadSeq
 
 proc nodeIdInNodes(id: NodeId, nodes: openarray[Node]): bool =
   for n in nodes:
     if id == n.id: return true
 
-proc test() {.async.} =
+procSuite "Discovery Tests":
-  suite "Discovery Tests":
+  let
+    bootNodeKey = PrivateKey.fromHex(
+      "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a617")[]
+    bootNodeAddr = localAddress(20301)
+    bootENode = ENode(pubkey: bootNodeKey.toPublicKey(), address: bootNodeAddr)
+    bootNode = initDiscoveryNode(bootNodeKey, bootNodeAddr, @[])
+  waitFor bootNode.bootstrap()
+
+  asyncTest "Discover nodes":
+    let nodeKeys = [
+      PrivateKey.fromHex(
+        "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a618")[],
+      PrivateKey.fromHex(
+        "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a619")[],
+      PrivateKey.fromHex(
+        "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a620")[]
+    ]
+
+    var nodes: seq[DiscoveryProtocol]
+    for i in 0..<nodeKeys.len:
+      let node = initDiscoveryNode(nodeKeys[i], localAddress(20302 + i),
+        @[bootENode])
+      nodes.add(node)
+
+    await allFutures(nodes.mapIt(it.bootstrap()))
+    nodes.add(bootNode)
+
+    for i in nodes:
+      for j in nodes:
+        if j != i:
+          check(nodeIdInNodes(i.thisNode.id, j.randomNodes(nodes.len - 1)))
+
+  test "Test Vectors":
+    # These are the test vectors from EIP-8:
+    # https://github.com/ethereum/EIPs/blob/master/EIPS/eip-8.md#rlpx-discovery-protocol
+    # However they are unpacked and the expiration is changed from 0x43b9a355
+    # to 0x6fd3aed7 so that they remain valid for a while
+    let validProtocolData = [
+      # ping packet with version 4, additional list elements
+      "01ec04cb847f000001820cfa8215a8d790000000000000000000000000000000018208ae820d05846fd3aed70102",
+      # ping packet with version 555, additional list elements and additional random data
+      "01f83e82022bd79020010db83c4d001500000000abcdef12820cfa8215a8d79020010db885a308d313198a2e037073488208ae82823a846fd3aed7c5010203040531b9019afde696e582a78fa8d95ea13ce3297d4afb8ba6433e4154caa5ac6431af1b80ba76023fa4090c408f6b4bc3701562c031041d4702971d102c9ab7fa5eed4cd6bab8f7af956f7d565ee1917084a95398b6a21eac920fe3dd1345ec0a7ef39367ee69ddf092cbfe5b93e5e568ebc491983c09c76d922dc3",
+      # pong packet with additional list elements and additional random data
+      "02f846d79020010db885a308d313198a2e037073488208ae82823aa0fbc914b16819237dcd8801d7e53f69e9719adecb3cc0e790c57e91ca4461c954846fd3aed7c6010203c2040506a0c969a58f6f9095004c0177a6b47f451530cab38966a25cca5cb58f055542124e",
+      # findnode packet with additional list elements and additional random data
+      "03f84eb840ca634cae0d49acb401d8a4c6b6fe8c55b70d115bf400769cc1400f3258cd31387574077f301b421bc84df7266c44e9e6d569fc56be00812904767bf5ccd1fc7f846fd3aed782999983999999280dc62cc8255c73471e0a61da0c89acdc0e035e260add7fc0c04ad9ebf3919644c91cb247affc82b69bd2ca235c71eab8e49737c937a2c396",
+      # neighbours packet with additional list elements and additional random data
+      "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",
+    ]
     let
-      bootNodeKey = PrivateKey.fromHex(
+      address = localAddress(20302)
-        "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a617")[]
+      nodeKey = PrivateKey.fromHex(
-      bootNodeAddr = localAddress(20301)
+        "b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")[]
-      bootENode = ENode(pubkey: bootNodeKey.toPublicKey(), address: bootNodeAddr)
-      bootNode = await startDiscoveryNode(bootNodeKey, bootNodeAddr, @[])
 
-    test "Discover nodes":
+    for data in validProtocolData:
-      let nodeKeys = [
+      # none of these may raise
-        PrivateKey.fromHex(
+      bootNode.receive(address, packData(hexToSeqByte(data), nodeKey))
-          "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a618")[],
-        PrivateKey.fromHex(
-          "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a619")[],
-        PrivateKey.fromHex(
-          "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a620")[]
-      ]
-      var nodeAddrs = newSeqOfCap[Address](nodeKeys.len)
-      for i in 0 ..< nodeKeys.len: nodeAddrs.add(localAddress(20302 + i))
 
-      var nodes = await all(zip(nodeKeys, nodeAddrs).mapIt(
+  test "Invalid protocol data":
-        startDiscoveryNode(it[0], it[1], @[bootENode]))
+    let invalidProtocolData = [
-      )
+      "0x00",   # invalid msg id
-      nodes.add(bootNode)
+      "0x01",   # empty payload
+      "0x03b8", # no list but string
+      "0x01C0", # empty list
+      # FindNode target that is 1 byte too long
+      # We currently do not raise on this, so can't really test it
+      # "0x03f847b841AA0000000000000000000000000000000000000000000000000000000000000000a99a96bd988e1839272f93257bd9dfb2e558390e1f9bff28cdc8f04c9b5d06b1846fd3aed7",
+    ]
+    let
+      address = localAddress(20302)
+      nodeKey = PrivateKey.fromHex(
+        "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a618")[]
 
-      for i in nodes:
+    for data in invalidProtocolData:
-        for j in nodes:
+      expect DiscProtocolError:
-          if j != i:
-            check(nodeIdInNodes(i.thisNode.id, j.randomNodes(nodes.len - 1)))
-
-    test "Test Vectors":
-      # These are the test vectors from EIP-8:
-      # https://github.com/ethereum/EIPs/blob/master/EIPS/eip-8.md#rlpx-discovery-protocol
-      # However they are unpacked and the expiration is changed from 0x43b9a355
-      # to 0x6fd3aed7 so that they remain valid for a while
-      let validProtocolData = [
-        # ping packet with version 4, additional list elements
-        "01ec04cb847f000001820cfa8215a8d790000000000000000000000000000000018208ae820d05846fd3aed70102",
-        # ping packet with version 555, additional list elements and additional random data
-        "01f83e82022bd79020010db83c4d001500000000abcdef12820cfa8215a8d79020010db885a308d313198a2e037073488208ae82823a846fd3aed7c5010203040531b9019afde696e582a78fa8d95ea13ce3297d4afb8ba6433e4154caa5ac6431af1b80ba76023fa4090c408f6b4bc3701562c031041d4702971d102c9ab7fa5eed4cd6bab8f7af956f7d565ee1917084a95398b6a21eac920fe3dd1345ec0a7ef39367ee69ddf092cbfe5b93e5e568ebc491983c09c76d922dc3",
-        # pong packet with additional list elements and additional random data
-        "02f846d79020010db885a308d313198a2e037073488208ae82823aa0fbc914b16819237dcd8801d7e53f69e9719adecb3cc0e790c57e91ca4461c954846fd3aed7c6010203c2040506a0c969a58f6f9095004c0177a6b47f451530cab38966a25cca5cb58f055542124e",
-        # findnode packet with additional list elements and additional random data
-        "03f84eb840ca634cae0d49acb401d8a4c6b6fe8c55b70d115bf400769cc1400f3258cd31387574077f301b421bc84df7266c44e9e6d569fc56be00812904767bf5ccd1fc7f846fd3aed782999983999999280dc62cc8255c73471e0a61da0c89acdc0e035e260add7fc0c04ad9ebf3919644c91cb247affc82b69bd2ca235c71eab8e49737c937a2c396",
-        # neighbours packet with additional list elements and additional random data
-        "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",
-      ]
-      let
-        address = localAddress(20302)
-        nodeKey = PrivateKey.fromHex(
-          "b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")[]
-
-      for data in validProtocolData:
-        # none of these may raise
         bootNode.receive(address, packData(hexToSeqByte(data), nodeKey))
 
-    test "Invalid protocol data":
+    # empty msg id and payload, doesn't raise, just fails and prints wrong
-      let invalidProtocolData = [
+    # msg mac
-        "0x00",   # invalid msg id
+    bootNode.receive(address, packData(@[], nodeKey))
-        "0x01",   # empty payload
-        "0x03b8", # no list but string
-        "0x01C0", # empty list
-        # FindNode target that is 1 byte too long
-        # We currently do not raise on this, so can't really test it
-        # "0x03f847b841AA0000000000000000000000000000000000000000000000000000000000000000a99a96bd988e1839272f93257bd9dfb2e558390e1f9bff28cdc8f04c9b5d06b1846fd3aed7",
-      ]
-      let
-        address = localAddress(20302)
-        nodeKey = PrivateKey.fromHex(
-          "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a618")[]
 
-      for data in invalidProtocolData:
+  asyncTest "Two findNode calls for the same peer in rapid succession":
-        expect DiscProtocolError:
+    let targetKey = PrivateKey.fromHex(
-          bootNode.receive(address, packData(hexToSeqByte(data), nodeKey))
+        "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a618")[]
+    let peerKey = PrivateKey.fromHex(
+        "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a619")[]
 
-      # empty msg id and payload, doesn't raise, just fails and prints wrong
+    let targetNodeId = kademlia.toNodeId(targetKey.toPublicKey)
-      # msg mac
+    let peerNode = kademlia.newNode(peerKey.toPublicKey, localAddress(20302))
-      bootNode.receive(address, packData(@[], nodeKey))
+    let nodesSeen = new(HashSet[Node])
 
-    test "Two findNode calls for the same peer in rapid succession":
+    # Start `findNode` but don't `await` yet, so the reply can't be processed yet.
-      let targetKey = PrivateKey.fromHex(
+    let neighbours1Future = bootNode.kademlia.findNode(nodesSeen, targetNodeId, peerNode)
-          "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a618")[]
-      let peerKey = PrivateKey.fromHex(
-          "a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a619")[]
 
-      let targetNodeId = kademlia.toNodeId(targetKey.toPublicKey)
+    # This will raise an assertion error if `findNode` doesn't check for and ignore
-      let peerNode = kademlia.newNode(peerKey.toPublicKey, localAddress(20302))
+    # this second call to the same target and peer in rapid successfion.
-      let nodesSeen = new(HashSet[Node])
+    let neighbours2Future = bootNode.kademlia.findNode(nodesSeen, targetNodeId, peerNode)
 
-      # Start `findNode` but don't `await` yet, so the reply can't be processed yet.
+    # Just for completness, verify the result is empty from the second call.
-      let neighbours1Future = bootNode.kademlia.findNode(nodesSeen, targetNodeId, peerNode)
+    let neighbours2 = await neighbours2Future
+    check(neighbours2.len == 0)
 
-      # This will raise an assertion error if `findNode` doesn't check for and ignore
+    # Just for completeness, wait for the first result out of order.
-      # this second call to the same target and peer in rapid successfion.
+    # Max delay 5 seconds.
-      let neighbours2Future = bootNode.kademlia.findNode(nodesSeen, targetNodeId, peerNode)
+    discard await neighbours1Future
-
-      # Just for completness, verify the result is empty from the second call.
-      let neighbours2 = await neighbours2Future
-      check(neighbours2.len == 0)
-
-      # Just for completeness, wait for the first result out of order.
-      # Max delay 5 seconds.
-      discard await neighbours1Future
-
-waitFor test()

tests/p2p/test_ecies.nim

@@ -7,6 +7,8 @@
 #    distribution, for details about the copyright.
 #
 
+{.used.}
+
 import
   std/unittest,
   nimcrypto/[utils, sha2, hmac, rijndael],

tests/p2p/test_enode.nim

@@ -7,6 +7,8 @@
 #  Apache License, version 2.0, (LICENSE-APACHEv2)
 #            MIT license (LICENSE-MIT)
 
+{.used.}
+
 import
   std/[unittest, net, options],
   ../../eth/p2p/enode