592 lines
19 KiB
Nim
592 lines
19 KiB
Nim
## Nim-LibP2P
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## Copyright (c) 2019 Status Research & Development GmbH
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## Licensed under either of
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## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
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## * MIT license ([LICENSE-MIT](LICENSE-MIT))
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## at your option.
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## This file may not be copied, modified, or distributed except according to
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## those terms.
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import tables,
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sequtils,
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options,
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sets,
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oids
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import chronos,
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chronicles,
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metrics
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import stream/connection,
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transports/transport,
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multistream,
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multiaddress,
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protocols/protocol,
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protocols/secure/secure,
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peerinfo,
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protocols/identify,
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muxers/muxer,
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connmanager,
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peerid,
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errors
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export connmanager
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logScope:
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topics = "switch"
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#TODO: General note - use a finite state machine to manage the different
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# steps of connections establishing and upgrading. This makes everything
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# more robust and less prone to ordering attacks - i.e. muxing can come if
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# and only if the channel has been secured (i.e. if a secure manager has been
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# previously provided)
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declareCounter(libp2p_dialed_peers, "dialed peers")
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declareCounter(libp2p_failed_dials, "failed dials")
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declareCounter(libp2p_failed_upgrade, "peers failed upgrade")
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type
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UpgradeFailedError* = object of CatchableError
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DialFailedError* = object of CatchableError
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Switch* = ref object of RootObj
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peerInfo*: PeerInfo
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connManager: ConnManager
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transports*: seq[Transport]
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protocols*: seq[LPProtocol]
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muxers*: Table[string, MuxerProvider]
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ms*: MultistreamSelect
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identity*: Identify
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streamHandler*: StreamHandler
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secureManagers*: seq[Secure]
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dialLock: Table[PeerID, AsyncLock]
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proc addConnEventHandler*(s: Switch,
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handler: ConnEventHandler,
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kind: ConnEventKind) =
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s.connManager.addConnEventHandler(handler, kind)
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proc removeConnEventHandler*(s: Switch,
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handler: ConnEventHandler,
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kind: ConnEventKind) =
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s.connManager.removeConnEventHandler(handler, kind)
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proc addPeerEventHandler*(s: Switch,
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handler: PeerEventHandler,
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kind: PeerEvent) =
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s.connManager.addPeerEventHandler(handler, kind)
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proc removePeerEventHandler*(s: Switch,
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handler: PeerEventHandler,
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kind: PeerEvent) =
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s.connManager.removePeerEventHandler(handler, kind)
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proc disconnect*(s: Switch, peerId: PeerID) {.async, gcsafe.}
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proc isConnected*(s: Switch, peerId: PeerID): bool =
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## returns true if the peer has one or more
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## associated connections (sockets)
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##
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peerId in s.connManager
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proc secure(s: Switch, conn: Connection): Future[Connection] {.async, gcsafe.} =
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if s.secureManagers.len <= 0:
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raise newException(UpgradeFailedError, "No secure managers registered!")
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let codec = await s.ms.select(conn, s.secureManagers.mapIt(it.codec))
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if codec.len == 0:
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raise newException(UpgradeFailedError, "Unable to negotiate a secure channel!")
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trace "Securing connection", conn, codec
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let secureProtocol = s.secureManagers.filterIt(it.codec == codec)
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# ms.select should deal with the correctness of this
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# let's avoid duplicating checks but detect if it fails to do it properly
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doAssert(secureProtocol.len > 0)
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return await secureProtocol[0].secure(conn, true)
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proc identify(s: Switch, conn: Connection) {.async, gcsafe.} =
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## identify the connection
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if (await s.ms.select(conn, s.identity.codec)):
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let info = await s.identity.identify(conn, conn.peerInfo)
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if info.pubKey.isNone and isNil(conn):
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raise newException(UpgradeFailedError,
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"no public key provided and no existing peer identity found")
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if isNil(conn.peerInfo):
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conn.peerInfo = PeerInfo.init(info.pubKey.get())
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if info.addrs.len > 0:
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conn.peerInfo.addrs = info.addrs
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if info.agentVersion.isSome:
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conn.peerInfo.agentVersion = info.agentVersion.get()
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if info.protoVersion.isSome:
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conn.peerInfo.protoVersion = info.protoVersion.get()
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if info.protos.len > 0:
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conn.peerInfo.protocols = info.protos
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trace "identified remote peer", conn, peerInfo = shortLog(conn.peerInfo)
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proc identify(s: Switch, muxer: Muxer) {.async, gcsafe.} =
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# new stream for identify
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var stream = await muxer.newStream()
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if stream == nil:
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return
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try:
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await s.identify(stream)
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finally:
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await stream.closeWithEOF()
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proc mux(s: Switch, conn: Connection): Future[Muxer] {.async, gcsafe.} =
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## mux incoming connection
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trace "Muxing connection", conn
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if s.muxers.len == 0:
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warn "no muxers registered, skipping upgrade flow", conn
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return
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let muxerName = await s.ms.select(conn, toSeq(s.muxers.keys()))
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if muxerName.len == 0 or muxerName == "na":
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debug "no muxer available, early exit", conn
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return
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trace "Found a muxer", conn, muxerName
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# create new muxer for connection
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let muxer = s.muxers[muxerName].newMuxer(conn)
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# install stream handler
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muxer.streamHandler = s.streamHandler
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s.connManager.storeOutgoing(conn)
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s.connManager.storeMuxer(muxer)
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# start muxer read loop - the future will complete when loop ends
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let handlerFut = muxer.handle()
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# store it in muxed connections if we have a peer for it
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s.connManager.storeMuxer(muxer, handlerFut) # update muxer with handler
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return muxer
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proc disconnect*(s: Switch, peerId: PeerID): Future[void] {.gcsafe.} =
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s.connManager.dropPeer(peerId)
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proc upgradeOutgoing(s: Switch, conn: Connection): Future[Connection] {.async, gcsafe.} =
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trace "Upgrading outgoing connection", conn
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let sconn = await s.secure(conn) # secure the connection
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if isNil(sconn):
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raise newException(UpgradeFailedError,
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"unable to secure connection, stopping upgrade")
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if sconn.peerInfo.isNil:
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raise newException(UpgradeFailedError,
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"current version of nim-libp2p requires that secure protocol negotiates peerid")
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let muxer = await s.mux(sconn) # mux it if possible
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if muxer == nil:
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# TODO this might be relaxed in the future
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raise newException(UpgradeFailedError,
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"a muxer is required for outgoing connections")
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try:
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await s.identify(muxer)
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except CatchableError as exc:
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# Identify is non-essential, though if it fails, it might indicate that
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# the connection was closed already - this will be picked up by the read
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# loop
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debug "Could not identify connection", conn, msg = exc.msg
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if isNil(sconn.peerInfo):
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await sconn.close()
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raise newException(UpgradeFailedError,
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"No peerInfo for connection, stopping upgrade")
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trace "Upgraded outgoing connection", conn, sconn
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return sconn
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proc upgradeIncoming(s: Switch, conn: Connection) {.async, gcsafe.} =
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trace "Upgrading incoming connection", conn
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let ms = newMultistream()
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# secure incoming connections
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proc securedHandler (conn: Connection,
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proto: string)
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{.async, gcsafe, closure.} =
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trace "Starting secure handler", conn
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let secure = s.secureManagers.filterIt(it.codec == proto)[0]
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try:
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var sconn = await secure.secure(conn, false)
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if isNil(sconn):
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return
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defer:
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await sconn.close()
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# add the muxer
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for muxer in s.muxers.values:
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ms.addHandler(muxer.codecs, muxer)
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# handle subsequent secure requests
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await ms.handle(sconn)
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except CancelledError as exc:
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raise exc
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except CatchableError as exc:
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debug "Exception in secure handler", msg = exc.msg, conn
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trace "Stopped secure handler", conn
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if (await ms.select(conn)): # just handshake
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# add the secure handlers
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for k in s.secureManagers:
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ms.addHandler(k.codec, securedHandler)
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# handle un-secured connections
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# we handshaked above, set this ms handler as active
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await ms.handle(conn, active = true)
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proc internalConnect(s: Switch,
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peerId: PeerID,
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addrs: seq[MultiAddress]): Future[Connection] {.async.} =
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if s.peerInfo.peerId == peerId:
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raise newException(CatchableError, "can't dial self!")
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var conn: Connection
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# Ensure there's only one in-flight attempt per peer
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let lock = s.dialLock.mgetOrPut(peerId, newAsyncLock())
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try:
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await lock.acquire()
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# Check if we have a connection already and try to reuse it
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conn = s.connManager.selectConn(peerId)
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if conn != nil:
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if conn.atEof or conn.closed:
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# This connection should already have been removed from the connection
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# manager - it's essentially a bug that we end up here - we'll fail
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# for now, hoping that this will clean themselves up later...
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warn "dead connection in connection manager", conn
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await conn.close()
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raise newException(DialFailedError, "Zombie connection encountered")
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trace "Reusing existing connection", conn, direction = $conn.dir
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return conn
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trace "Dialing peer", peerId
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for t in s.transports: # for each transport
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for a in addrs: # for each address
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if t.handles(a): # check if it can dial it
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trace "Dialing address", address = $a, peerId
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let dialed = try:
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await t.dial(a)
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except CancelledError as exc:
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trace "Dialing canceled", msg = exc.msg, peerId
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raise exc
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except CatchableError as exc:
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trace "Dialing failed", msg = exc.msg, peerId
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libp2p_failed_dials.inc()
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continue # Try the next address
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# make sure to assign the peer to the connection
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dialed.peerInfo = PeerInfo.init(peerId, addrs)
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libp2p_dialed_peers.inc()
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let upgraded = try:
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await s.upgradeOutgoing(dialed)
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except CatchableError as exc:
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# If we failed to establish the connection through one transport,
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# we won't succeeed through another - no use in trying again
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await dialed.close()
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debug "Upgrade failed", msg = exc.msg, peerId
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if exc isnot CancelledError:
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libp2p_failed_upgrade.inc()
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raise exc
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doAssert not isNil(upgraded), "connection died after upgradeOutgoing"
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conn = upgraded
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trace "Dial successful", conn, peerInfo = conn.peerInfo
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break
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finally:
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if lock.locked():
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lock.release()
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if isNil(conn): # None of the addresses connected
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raise newException(CatchableError, "Unable to establish outgoing link")
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if conn.closed():
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# This can happen if one of the peer event handlers deems the peer
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# unworthy and disconnects it
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raise newLPStreamClosedError()
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await s.connManager.triggerPeerEvents(peerId, PeerEvent.Joined)
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await s.connManager.triggerConnEvent(
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peerId, ConnEvent(kind: ConnEventKind.Connected, incoming: false))
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proc peerCleanup() {.async.} =
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try:
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await conn.closeEvent.wait()
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await s.connManager.triggerConnEvent(
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peerId, ConnEvent(kind: ConnEventKind.Disconnected))
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await s.connManager.triggerPeerEvents(peerId, PeerEvent.Left)
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except CatchableError as exc:
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# This is top-level procedure which will work as separate task, so it
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# do not need to propogate CancelledError and should handle other errors
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warn "Unexpected exception in switch peer connect cleanup",
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conn, msg = exc.msg
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# All the errors are handled inside `cleanup()` procedure.
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asyncSpawn peerCleanup()
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return conn
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proc connect*(s: Switch, peerId: PeerID, addrs: seq[MultiAddress]) {.async.} =
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discard await s.internalConnect(peerId, addrs)
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proc negotiateStream(s: Switch, conn: Connection, protos: seq[string]): Future[Connection] {.async.} =
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trace "Negotiating stream", conn, protos
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let selected = await s.ms.select(conn, protos)
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if not protos.contains(selected):
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await conn.closeWithEOF()
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raise newException(DialFailedError, "Unable to select sub-protocol " & $protos)
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return conn
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proc dial*(s: Switch,
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peerId: PeerID,
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protos: seq[string]): Future[Connection] {.async.} =
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trace "Dialing (existing)", peerId, protos
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let stream = await s.connManager.getMuxedStream(peerId)
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if stream.isNil:
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raise newException(DialFailedError, "Couldn't get muxed stream")
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return await s.negotiateStream(stream, protos)
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proc dial*(s: Switch,
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peerId: PeerID,
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proto: string): Future[Connection] = dial(s, peerId, @[proto])
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proc dial*(s: Switch,
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peerId: PeerID,
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addrs: seq[MultiAddress],
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protos: seq[string]):
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Future[Connection] {.async.} =
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trace "Dialing (new)", peerId, protos
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let conn = await s.internalConnect(peerId, addrs)
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trace "Opening stream", conn
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let stream = await s.connManager.getMuxedStream(conn)
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proc cleanup() {.async.} =
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if not(isNil(stream)):
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await stream.closeWithEOF()
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if not(isNil(conn)):
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await conn.close()
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try:
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if isNil(stream):
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await conn.close()
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raise newException(DialFailedError, "Couldn't get muxed stream")
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return await s.negotiateStream(stream, protos)
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except CancelledError as exc:
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trace "Dial canceled", conn
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await cleanup()
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raise exc
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except CatchableError as exc:
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debug "Error dialing", conn, msg = exc.msg
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await cleanup()
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raise exc
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proc dial*(s: Switch,
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peerId: PeerID,
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addrs: seq[MultiAddress],
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proto: string):
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Future[Connection] = dial(s, peerId, addrs, @[proto])
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proc mount*[T: LPProtocol](s: Switch, proto: T, matcher: Matcher = nil) {.gcsafe.} =
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if isNil(proto.handler):
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raise newException(CatchableError,
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"Protocol has to define a handle method or proc")
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if proto.codec.len == 0:
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raise newException(CatchableError,
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"Protocol has to define a codec string")
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s.ms.addHandler(proto.codecs, proto, matcher)
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proc start*(s: Switch): Future[seq[Future[void]]] {.async, gcsafe.} =
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trace "starting switch for peer", peerInfo = s.peerInfo
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proc handle(conn: Connection): Future[void] {.async, closure, gcsafe.} =
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trace "Incoming connection", conn
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try:
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await s.upgradeIncoming(conn) # perform upgrade on incoming connection
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except CancelledError as exc:
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raise exc
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except CatchableError as exc:
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trace "Exception occurred in incoming handler", conn, msg = exc.msg
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finally:
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await conn.close()
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trace "Connection handler done", conn
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var startFuts: seq[Future[void]]
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for t in s.transports: # for each transport
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for i, a in s.peerInfo.addrs:
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if t.handles(a): # check if it handles the multiaddr
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var server = await t.listen(a, handle)
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s.peerInfo.addrs[i] = t.ma # update peer's address
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startFuts.add(server)
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debug "Started libp2p node", peer = s.peerInfo
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result = startFuts # listen for incoming connections
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proc stop*(s: Switch) {.async.} =
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trace "Stopping switch"
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# close and cleanup all connections
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await s.connManager.close()
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for t in s.transports:
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try:
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await t.close()
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except CancelledError as exc:
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raise exc
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except CatchableError as exc:
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warn "error cleaning up transports", msg = exc.msg
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trace "Switch stopped"
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proc muxerHandler(s: Switch, muxer: Muxer) {.async, gcsafe.} =
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let
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conn = muxer.connection
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if conn.peerInfo.isNil:
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warn "This version of nim-libp2p requires secure protocol to negotiate peerid"
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await muxer.close()
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return
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# store incoming connection
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s.connManager.storeIncoming(conn)
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# store muxer and muxed connection
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s.connManager.storeMuxer(muxer)
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try:
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await s.identify(muxer)
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except CatchableError as exc:
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# Identify is non-essential, though if it fails, it might indicate that
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# the connection was closed already - this will be picked up by the read
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# loop
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debug "Could not identify connection", conn, msg = exc.msg
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try:
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let peerId = conn.peerInfo.peerId
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proc peerCleanup() {.async.} =
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try:
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await muxer.connection.join()
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await s.connManager.triggerConnEvent(
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peerId, ConnEvent(kind: ConnEventKind.Disconnected))
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await s.connManager.triggerPeerEvents(peerId, PeerEvent.Left)
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except CatchableError as exc:
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# This is top-level procedure which will work as separate task, so it
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# do not need to propogate CancelledError and shouldn't leak others
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debug "Unexpected exception in switch muxer cleanup",
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conn, msg = exc.msg
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proc peerStartup() {.async.} =
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try:
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await s.connManager.triggerPeerEvents(peerId, PeerEvent.Joined)
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await s.connManager.triggerConnEvent(peerId,
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ConnEvent(kind: ConnEventKind.Connected, incoming: true))
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except CatchableError as exc:
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# This is top-level procedure which will work as separate task, so it
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# do not need to propogate CancelledError and shouldn't leak others
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debug "Unexpected exception in switch muxer startup",
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conn, msg = exc.msg
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# All the errors are handled inside `peerStartup()` procedure.
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asyncSpawn peerStartup()
|
|
|
|
# All the errors are handled inside `peerCleanup()` procedure.
|
|
asyncSpawn peerCleanup()
|
|
|
|
except CancelledError as exc:
|
|
await muxer.close()
|
|
raise exc
|
|
except CatchableError as exc:
|
|
await muxer.close()
|
|
libp2p_failed_upgrade.inc()
|
|
trace "Exception in muxer handler", conn, msg = exc.msg
|
|
|
|
proc newSwitch*(peerInfo: PeerInfo,
|
|
transports: seq[Transport],
|
|
identity: Identify,
|
|
muxers: Table[string, MuxerProvider],
|
|
secureManagers: openarray[Secure] = []): Switch =
|
|
if secureManagers.len == 0:
|
|
raise (ref CatchableError)(msg: "Provide at least one secure manager")
|
|
|
|
let switch = Switch(
|
|
peerInfo: peerInfo,
|
|
ms: newMultistream(),
|
|
transports: transports,
|
|
connManager: ConnManager.init(),
|
|
identity: identity,
|
|
muxers: muxers,
|
|
secureManagers: @secureManagers,
|
|
)
|
|
|
|
switch.streamHandler = proc(conn: Connection) {.async, gcsafe.} = # noraises
|
|
trace "Starting stream handler", conn
|
|
try:
|
|
await switch.ms.handle(conn) # handle incoming connection
|
|
except CancelledError as exc:
|
|
raise exc
|
|
except CatchableError as exc:
|
|
trace "exception in stream handler", conn, msg = exc.msg
|
|
finally:
|
|
await conn.closeWithEOF()
|
|
trace "Stream handler done", conn
|
|
|
|
switch.mount(identity)
|
|
for key, val in muxers:
|
|
val.streamHandler = switch.streamHandler
|
|
val.muxerHandler = proc(muxer: Muxer): Future[void] =
|
|
switch.muxerHandler(muxer)
|
|
|
|
return switch
|
|
|
|
proc isConnected*(s: Switch, peerInfo: PeerInfo): bool
|
|
{.deprecated: "Use PeerID version".} =
|
|
not isNil(peerInfo) and isConnected(s, peerInfo.peerId)
|
|
|
|
proc disconnect*(s: Switch, peerInfo: PeerInfo): Future[void]
|
|
{.deprecated: "Use PeerID version", gcsafe.} =
|
|
disconnect(s, peerInfo.peerId)
|
|
|
|
proc connect*(s: Switch, peerInfo: PeerInfo): Future[void]
|
|
{.deprecated: "Use PeerID version".} =
|
|
connect(s, peerInfo.peerId, peerInfo.addrs)
|
|
|
|
proc dial*(s: Switch,
|
|
peerInfo: PeerInfo,
|
|
proto: string):
|
|
Future[Connection]
|
|
{.deprecated: "Use PeerID version".} =
|
|
dial(s, peerInfo.peerId, peerInfo.addrs, proto)
|