mirror of https://github.com/status-im/nim-eth.git
354 lines
12 KiB
Nim
354 lines
12 KiB
Nim
#
|
|
# Ethereum P2P
|
|
# (c) Copyright 2018
|
|
# Status Research & Development GmbH
|
|
#
|
|
# Licensed under either of
|
|
# Apache License, version 2.0, (LICENSE-APACHEv2)
|
|
# MIT license (LICENSE-MIT)
|
|
#
|
|
|
|
import
|
|
times,
|
|
chronos, stint, nimcrypto, chronicles,
|
|
eth/[keys, rlp],
|
|
kademlia, enode,
|
|
stew/[objects, results]
|
|
|
|
export
|
|
Node, results
|
|
|
|
logScope:
|
|
topics = "discovery"
|
|
|
|
const
|
|
# UDP packet constants.
|
|
MAC_SIZE = 256 div 8 # 32
|
|
SIG_SIZE = 520 div 8 # 65
|
|
HEAD_SIZE = MAC_SIZE + SIG_SIZE # 97
|
|
EXPIRATION = 60 # let messages expire after N secondes
|
|
PROTO_VERSION = 4
|
|
|
|
type
|
|
DiscoveryProtocol* = ref object
|
|
privKey: PrivateKey
|
|
address: Address
|
|
bootstrapNodes*: seq[Node]
|
|
thisNode*: Node
|
|
kademlia: KademliaProtocol[DiscoveryProtocol]
|
|
transp: DatagramTransport
|
|
|
|
CommandId = enum
|
|
cmdPing = 1
|
|
cmdPong = 2
|
|
cmdFindNode = 3
|
|
cmdNeighbours = 4
|
|
|
|
DiscProtocolError* = object of CatchableError
|
|
|
|
DiscResult*[T] = Result[T, cstring]
|
|
|
|
const MinListLen: array[CommandId, int] = [4, 3, 2, 2]
|
|
|
|
proc append*(w: var RlpWriter, a: IpAddress) =
|
|
case a.family
|
|
of IpAddressFamily.IPv6:
|
|
w.append(a.address_v6)
|
|
of IpAddressFamily.IPv4:
|
|
w.append(a.address_v4)
|
|
|
|
proc append(w: var RlpWriter, p: Port) {.inline.} = w.append(p.int)
|
|
proc append(w: var RlpWriter, pk: PublicKey) {.inline.} = w.append(pk.toRaw())
|
|
proc append(w: var RlpWriter, h: MDigest[256]) {.inline.} = w.append(h.data)
|
|
|
|
proc pack(cmdId: CommandId, payload: openArray[byte], pk: PrivateKey): seq[byte] =
|
|
## Create and sign a UDP message to be sent to a remote node.
|
|
##
|
|
## See https://github.com/ethereum/devp2p/blob/master/rlpx.md#node-discovery for information on
|
|
## how UDP packets are structured.
|
|
|
|
# TODO: There is a lot of unneeded allocations here
|
|
let encodedData = @[cmdId.byte] & @payload
|
|
let signature = @(pk.sign(encodedData).tryGet().toRaw())
|
|
let msgHash = keccak256.digest(signature & encodedData)
|
|
result = @(msgHash.data) & signature & encodedData
|
|
|
|
proc validateMsgHash(msg: openArray[byte]): DiscResult[MDigest[256]] =
|
|
if msg.len > HEAD_SIZE:
|
|
var ret: MDigest[256]
|
|
ret.data[0 .. ^1] = msg.toOpenArray(0, ret.data.high)
|
|
if ret == keccak256.digest(msg.toOpenArray(MAC_SIZE, msg.high)):
|
|
ok(ret)
|
|
else:
|
|
err("disc: invalid message hash")
|
|
else:
|
|
err("disc: msg missing hash")
|
|
|
|
proc recoverMsgPublicKey(msg: openArray[byte]): DiscResult[PublicKey] =
|
|
if msg.len <= HEAD_SIZE:
|
|
return err("disc: can't get public key")
|
|
let sig = ? Signature.fromRaw(msg.toOpenArray(MAC_SIZE, HEAD_SIZE))
|
|
recover(sig, msg.toOpenArray(HEAD_SIZE, msg.high))
|
|
|
|
proc unpack(msg: openArray[byte]): tuple[cmdId: CommandId, payload: seq[byte]] =
|
|
# Check against possible RangeError
|
|
if msg[HEAD_SIZE].int < CommandId.low.ord or
|
|
msg[HEAD_SIZE].int > CommandId.high.ord:
|
|
raise newException(DiscProtocolError, "Unsupported packet id")
|
|
|
|
result = (cmdId: msg[HEAD_SIZE].CommandId, payload: msg[HEAD_SIZE + 1 .. ^1])
|
|
|
|
proc expiration(): uint32 =
|
|
result = uint32(epochTime() + EXPIRATION)
|
|
|
|
# Wire protocol
|
|
|
|
proc send(d: DiscoveryProtocol, n: Node, data: seq[byte]) =
|
|
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] =
|
|
let payload = rlp.encode((PROTO_VERSION, d.address, n.node.address,
|
|
expiration()))
|
|
let msg = pack(cmdPing, payload, d.privKey)
|
|
result = msg[0 ..< MAC_SIZE]
|
|
trace ">>> ping ", n
|
|
d.send(n, msg)
|
|
|
|
proc sendPong*(d: DiscoveryProtocol, n: Node, token: MDigest[256]) =
|
|
let payload = rlp.encode((n.node.address, token, expiration()))
|
|
let msg = pack(cmdPong, payload, d.privKey)
|
|
trace ">>> pong ", n
|
|
d.send(n, msg)
|
|
|
|
proc sendFindNode*(d: DiscoveryProtocol, n: Node, targetNodeId: NodeId) =
|
|
var data: array[64, byte]
|
|
data[32 .. ^1] = targetNodeId.toByteArrayBE()
|
|
let payload = rlp.encode((data, expiration()))
|
|
let msg = pack(cmdFindNode, payload, d.privKey)
|
|
trace ">>> find_node to ", n#, ": ", msg.toHex()
|
|
d.send(n, msg)
|
|
|
|
proc sendNeighbours*(d: DiscoveryProtocol, node: Node, neighbours: seq[Node]) =
|
|
const MAX_NEIGHBOURS_PER_PACKET = 12 # TODO: Implement a smarter way to compute it
|
|
type Neighbour = tuple[ip: IpAddress, udpPort, tcpPort: Port, pk: PublicKey]
|
|
var nodes = newSeqOfCap[Neighbour](MAX_NEIGHBOURS_PER_PACKET)
|
|
shallow(nodes)
|
|
|
|
template flush() =
|
|
block:
|
|
let payload = rlp.encode((nodes, expiration()))
|
|
let msg = pack(cmdNeighbours, payload, d.privkey)
|
|
trace "Neighbours to", node, nodes
|
|
d.send(node, msg)
|
|
nodes.setLen(0)
|
|
|
|
for i, n in neighbours:
|
|
nodes.add((n.node.address.ip, n.node.address.udpPort,
|
|
n.node.address.tcpPort, n.node.pubkey))
|
|
if nodes.len == MAX_NEIGHBOURS_PER_PACKET:
|
|
flush()
|
|
|
|
if nodes.len != 0: flush()
|
|
|
|
proc newDiscoveryProtocol*(privKey: PrivateKey, address: Address,
|
|
bootstrapNodes: openarray[ENode]
|
|
): DiscoveryProtocol =
|
|
result.new()
|
|
result.privKey = privKey
|
|
result.address = address
|
|
result.bootstrapNodes = newSeqOfCap[Node](bootstrapNodes.len)
|
|
for n in bootstrapNodes: result.bootstrapNodes.add(newNode(n))
|
|
result.thisNode = newNode(privKey.toPublicKey().tryGet(), address)
|
|
result.kademlia = newKademliaProtocol(result.thisNode, result)
|
|
|
|
proc recvPing(d: DiscoveryProtocol, node: Node,
|
|
msgHash: MDigest[256]) {.inline.} =
|
|
d.kademlia.recvPing(node, msgHash)
|
|
|
|
proc recvPong(d: DiscoveryProtocol, node: Node, payload: seq[byte]) {.inline.} =
|
|
let rlp = rlpFromBytes(payload)
|
|
let tok = rlp.listElem(1).toBytes()
|
|
d.kademlia.recvPong(node, tok)
|
|
|
|
proc recvNeighbours(d: DiscoveryProtocol, node: Node,
|
|
payload: seq[byte]) {.inline.} =
|
|
let rlp = rlpFromBytes(payload)
|
|
let neighboursList = rlp.listElem(0)
|
|
let sz = neighboursList.listLen()
|
|
|
|
var neighbours = newSeqOfCap[Node](16)
|
|
for i in 0 ..< sz:
|
|
let n = neighboursList.listElem(i)
|
|
let ipBlob = n.listElem(0).toBytes
|
|
var ip: IpAddress
|
|
case ipBlob.len
|
|
of 4:
|
|
ip = IpAddress(
|
|
family: IpAddressFamily.IPv4, address_v4: toArray(4, ipBlob))
|
|
of 16:
|
|
ip = IpAddress(
|
|
family: IpAddressFamily.IPv6, address_v6: toArray(16, ipBlob))
|
|
else:
|
|
error "Wrong ip address length!"
|
|
continue
|
|
|
|
let udpPort = n.listElem(1).toInt(uint16).Port
|
|
let tcpPort = n.listElem(2).toInt(uint16).Port
|
|
let pk = PublicKey.fromRaw(n.listElem(3).toBytes)
|
|
if pk.isErr:
|
|
warn "Could not parse public key"
|
|
continue
|
|
|
|
neighbours.add(newNode(pk[], Address(ip: ip, udpPort: udpPort, tcpPort: tcpPort)))
|
|
d.kademlia.recvNeighbours(node, neighbours)
|
|
|
|
proc recvFindNode(d: DiscoveryProtocol, node: Node, payload: openArray[byte]) {.inline, gcsafe.} =
|
|
let rlp = rlpFromBytes(payload)
|
|
trace "<<< find_node from ", node
|
|
let rng = rlp.listElem(0).toBytes
|
|
# Check for pubkey len
|
|
if rng.len == 64:
|
|
let nodeId = readUIntBE[256](rng[32 .. ^1])
|
|
d.kademlia.recvFindNode(node, nodeId)
|
|
else:
|
|
trace "Invalid target public key received"
|
|
|
|
proc expirationValid(cmdId: CommandId, rlpEncodedPayload: openArray[byte]):
|
|
bool {.inline, raises:[DiscProtocolError, RlpError].} =
|
|
## Can only raise `DiscProtocolError` and all of `RlpError`
|
|
# Check if there is a payload
|
|
if rlpEncodedPayload.len <= 0:
|
|
raise newException(DiscProtocolError, "RLP stream is empty")
|
|
let rlp = rlpFromBytes(rlpEncodedPayload)
|
|
# Check payload is an RLP list and if the list has the minimum items required
|
|
# for this packet type
|
|
if rlp.isList and rlp.listLen >= MinListLen[cmdId]:
|
|
# Expiration is always the last mandatory item of the list
|
|
let expiration = rlp.listElem(MinListLen[cmdId] - 1).toInt(uint32)
|
|
result = epochTime() <= expiration.float
|
|
else:
|
|
raise newException(DiscProtocolError, "Invalid RLP list for this packet id")
|
|
|
|
proc receive*(d: DiscoveryProtocol, a: Address, msg: openArray[byte]) {.gcsafe.} =
|
|
## Can raise `DiscProtocolError` and all of `RlpError`
|
|
# Note: export only needed for testing
|
|
let msgHash = validateMsgHash(msg)
|
|
if msgHash.isOk():
|
|
let remotePubkey = recoverMsgPublicKey(msg)
|
|
if remotePubkey.isOk:
|
|
let (cmdId, payload) = unpack(msg)
|
|
|
|
if expirationValid(cmdId, payload):
|
|
let node = newNode(remotePubkey[], a)
|
|
case cmdId
|
|
of cmdPing:
|
|
d.recvPing(node, msgHash[])
|
|
of cmdPong:
|
|
d.recvPong(node, payload)
|
|
of cmdNeighbours:
|
|
d.recvNeighbours(node, payload)
|
|
of cmdFindNode:
|
|
d.recvFindNode(node, payload)
|
|
else:
|
|
trace "Received msg already expired", cmdId, a
|
|
else:
|
|
notice "Wrong public key from ", a, err = remotePubkey.error
|
|
else:
|
|
notice "Wrong msg mac from ", a
|
|
|
|
proc processClient(transp: DatagramTransport,
|
|
raddr: TransportAddress): Future[void] {.async, gcsafe.} =
|
|
var proto = getUserData[DiscoveryProtocol](transp)
|
|
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:
|
|
debug "Receive failed", exc = e.name, err = e.msg
|
|
raise e
|
|
|
|
proc open*(d: DiscoveryProtocol) =
|
|
# TODO allow binding to specific IP / IPv6 / etc
|
|
let ta = initTAddress(IPv4_any(), d.address.udpPort)
|
|
d.transp = newDatagramTransport(processClient, udata = d, local = ta)
|
|
|
|
proc lookupRandom*(d: DiscoveryProtocol): Future[seq[Node]] {.inline.} =
|
|
d.kademlia.lookupRandom()
|
|
|
|
proc run(d: DiscoveryProtocol) {.async.} =
|
|
while true:
|
|
discard await d.lookupRandom()
|
|
await sleepAsync(3000)
|
|
trace "Discovered nodes", nodes = d.kademlia.nodesDiscovered
|
|
|
|
proc bootstrap*(d: DiscoveryProtocol) {.async.} =
|
|
await d.kademlia.bootstrap(d.bootstrapNodes)
|
|
discard d.run()
|
|
|
|
proc resolve*(d: DiscoveryProtocol, n: NodeId): Future[Node] =
|
|
d.kademlia.resolve(n)
|
|
|
|
proc randomNodes*(d: DiscoveryProtocol, count: int): seq[Node] {.inline.} =
|
|
d.kademlia.randomNodes(count)
|
|
|
|
when isMainModule:
|
|
import logging, stew/byteutils
|
|
|
|
const LOCAL_BOOTNODES = [
|
|
"enode://6456719e7267e061161c88720287a77b80718d2a3a4ff5daeba614d029dc77601b75e32190aed1c9b0b9ccb6fac3bcf000f48e54079fa79e339c25d8e9724226@127.0.0.1:30301"
|
|
]
|
|
|
|
addHandler(newConsoleLogger())
|
|
|
|
block:
|
|
let m = hexToSeqByte"79664bff52ee17327b4a2d8f97d8fb32c9244d719e5038eb4f6b64da19ca6d271d659c3ad9ad7861a928ca85f8d8debfbe6b7ade26ad778f2ae2ba712567fcbd55bc09eb3e74a893d6b180370b266f6aaf3fe58a0ad95f7435bf3ddf1db940d20102f2cb842edbd4d182944382765da0ab56fb9e64a85a597e6bb27c656b4f1afb7e06b0fd4e41ccde6dba69a3c4a150845aaa4de2"
|
|
discard validateMsgHash(m).expect("valid hash")
|
|
var remotePubkey = recoverMsgPublicKey(m).expect("valid key")
|
|
|
|
let (cmdId, payload) = unpack(m)
|
|
doAssert(payload == hexToSeqByte"f2cb842edbd4d182944382765da0ab56fb9e64a85a597e6bb27c656b4f1afb7e06b0fd4e41ccde6dba69a3c4a150845aaa4de2")
|
|
doAssert(cmdId == cmdPong)
|
|
doAssert(remotePubkey == PublicKey.fromHex(
|
|
"78de8a0916848093c73790ead81d1928bec737d565119932b98c6b100d944b7a95e94f847f689fc723399d2e31129d182f7ef3863f2b4c820abbf3ab2722344d")[])
|
|
|
|
let privKey = PrivateKey.fromHex("a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a617")[]
|
|
|
|
# echo privKey
|
|
|
|
# block:
|
|
# var b = @[1.byte, 2, 3]
|
|
# let m = pack(cmdPing, b.initBytesRange, privKey)
|
|
# let (remotePubkey, cmdId, payload) = unpack(m)
|
|
# doAssert(remotePubkey.raw_key.toHex == privKey.public_key.raw_key.toHex)
|
|
|
|
var bootnodes = newSeq[ENode]()
|
|
for item in LOCAL_BOOTNODES:
|
|
bootnodes.add(ENode.fromString(item)[])
|
|
|
|
let listenPort = Port(30310)
|
|
var address = Address(udpPort: listenPort, tcpPort: listenPort)
|
|
address.ip.family = IpAddressFamily.IPv4
|
|
let discovery = newDiscoveryProtocol(privkey, address, bootnodes)
|
|
|
|
echo discovery.thisNode.node.pubkey
|
|
echo "this_node.id: ", discovery.thisNode.id.toHex()
|
|
|
|
discovery.open()
|
|
|
|
proc test() {.async.} =
|
|
{.gcsafe.}:
|
|
await discovery.bootstrap()
|
|
|
|
waitFor test()
|