561 lines
16 KiB
Nim
561 lines
16 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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protocols/pubsub/pubsub,
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muxers/muxer,
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connmanager,
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peerid
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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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NoPubSubException* = 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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pubSub*: Option[PubSub]
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dialLock: Table[string, AsyncLock]
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proc newNoPubSubException(): ref NoPubSubException {.inline.} =
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result = newException(NoPubSubException, "no pubsub provided!")
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proc disconnect*(s: Switch, peer: PeerInfo) {.async, gcsafe.}
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proc subscribePeer*(s: Switch, peerInfo: PeerInfo) {.async, gcsafe.}
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proc cleanupPubSubPeer(s: Switch, conn: Connection) {.async.} =
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await conn.closeEvent.wait()
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if s.pubSub.isSome:
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await s.pubSub.get().unsubscribePeer(conn.peerInfo)
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proc isConnected*(s: Switch, peer: PeerInfo): 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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peer.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(CatchableError, "No secure managers registered!")
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let manager = await s.ms.select(conn, s.secureManagers.mapIt(it.codec))
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if manager.len == 0:
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raise newException(CatchableError, "Unable to negotiate a secure channel!")
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trace "securing connection", codec = manager
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let secureProtocol = s.secureManagers.filterIt(it.codec == manager)
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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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result = 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(CatchableError,
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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 "identify: identified remote peer", peer = $conn.peerInfo
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proc mux(s: Switch, conn: Connection) {.async, gcsafe.} =
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## mux incoming connection
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trace "muxing connection", peer = $conn
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let muxers = toSeq(s.muxers.keys)
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if muxers.len == 0:
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warn "no muxers registered, skipping upgrade flow"
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return
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let muxerName = await s.ms.select(conn, muxers)
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if muxerName.len == 0 or muxerName == "na":
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debug "no muxer available, early exit", peer = $conn
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return
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# create new muxer for connection
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let muxer = s.muxers[muxerName].newMuxer(conn)
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s.connManager.storeMuxer(muxer)
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trace "found a muxer", name = muxerName, peer = $conn
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# install stream handler
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muxer.streamHandler = s.streamHandler
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# new stream for identify
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var stream = await muxer.newStream()
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var handlerFut: Future[void]
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defer:
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if not(isNil(stream)):
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await stream.close() # close identify stream
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# call muxer handler, this should
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# not end until muxer ends
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handlerFut = muxer.handle()
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# do identify first, so that we have a
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# PeerInfo in case we didn't before
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await s.identify(stream)
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if isNil(conn.peerInfo):
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await muxer.close()
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raise newException(CatchableError,
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"unable to identify peer, aborting upgrade")
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# store it in muxed connections if we have a peer for it
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trace "adding muxer for peer", peer = conn.peerInfo.id
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s.connManager.storeMuxer(muxer, handlerFut) # update muxer with handler
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proc disconnect*(s: Switch, peer: PeerInfo) {.async, gcsafe.} =
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await s.connManager.dropPeer(peer)
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proc upgradeOutgoing(s: Switch, conn: Connection): Future[Connection] {.async, gcsafe.} =
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logScope:
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conn = $conn
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oid = $conn.oid
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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(CatchableError,
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"unable to secure connection, stopping upgrade")
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trace "upgrading connection"
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await s.mux(sconn) # mux it if possible
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if isNil(sconn.peerInfo):
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await sconn.close()
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raise newException(CatchableError,
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"unable to mux connection, stopping upgrade")
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trace "succesfully upgraded outgoing connection", uoid = sconn.oid
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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 = $conn, oid = conn.oid
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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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var sconn: Connection
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trace "Securing connection", oid = conn.oid
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let secure = s.secureManagers.filterIt(it.codec == proto)[0]
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try:
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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.codec, muxer)
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# handle subsequent 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 "ending secured handler", err = exc.msg
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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 secured connections
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await ms.handle(conn)
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proc internalConnect(s: Switch,
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peer: PeerInfo): Future[Connection] {.async.} =
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if s.peerInfo.peerId == peer.peerId:
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raise newException(CatchableError, "can't dial self!")
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let id = peer.id
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var conn: Connection
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let lock = s.dialLock.mgetOrPut(id, newAsyncLock())
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try:
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await lock.acquire()
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trace "about to dial peer", peer = id
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conn = s.connManager.selectConn(peer)
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if conn.isNil or (conn.closed or conn.atEof):
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trace "Dialing peer", peer = id
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for t in s.transports: # for each transport
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for a in peer.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, peer = id
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try:
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conn = await t.dial(a)
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# make sure to assign the peer to the connection
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conn.peerInfo = peer
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libp2p_dialed_peers.inc()
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except CancelledError as exc:
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trace "dialing canceled", exc = exc.msg
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raise
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except CatchableError as exc:
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trace "dialing failed", exc = exc.msg
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libp2p_failed_dials.inc()
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continue
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try:
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let uconn = await s.upgradeOutgoing(conn)
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s.connManager.storeOutgoing(uconn)
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conn = uconn
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except CatchableError as exc:
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if not(isNil(conn)):
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await conn.close()
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trace "Unable to establish outgoing link", exc = exc.msg
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raise exc
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if isNil(conn):
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libp2p_failed_upgrade.inc()
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continue
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break
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else:
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trace "Reusing existing connection", oid = conn.oid
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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):
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raise newException(CatchableError,
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"Unable to establish outgoing link")
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if conn.closed or conn.atEof:
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await conn.close()
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raise newException(CatchableError,
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"Connection dead on arrival")
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doAssert(conn in s.connManager, "connection not tracked!")
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trace "dial succesfull", oid = $conn.oid,
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peer = $conn.peerInfo
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await s.subscribePeer(peer)
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asyncCheck s.cleanupPubSubPeer(conn)
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return conn
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proc connect*(s: Switch, peer: PeerInfo) {.async.} =
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discard await s.internalConnect(peer)
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proc dial*(s: Switch,
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peer: PeerInfo,
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proto: string):
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Future[Connection] {.async.} =
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let conn = await s.internalConnect(peer)
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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.close()
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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(CatchableError, "Couldn't get muxed stream")
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trace "Attempting to select remote", proto = proto, oid = conn.oid
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if not await s.ms.select(stream, proto):
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await stream.close()
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raise newException(CatchableError, "Unable to select sub-protocol " & proto)
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return stream
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except CancelledError as exc:
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trace "dial canceled"
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await cleanup()
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raise exc
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except CatchableError as exc:
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trace "error dialing"
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await cleanup()
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raise exc
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proc mount*[T: LPProtocol](s: Switch, proto: T) {.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.codec, proto)
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proc start*(s: Switch): Future[seq[Future[void]]] {.async, gcsafe.} =
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trace "starting switch for peer", peerInfo = shortLog(s.peerInfo)
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proc handle(conn: Connection): Future[void] {.async, closure, gcsafe.} =
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try:
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conn.dir = Direction.In # tag connection with direction
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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 Switch.start", exc = exc.msg
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finally:
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await conn.close()
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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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if s.pubSub.isSome:
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await s.pubSub.get().start()
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info "started libp2p node", peer = $s.peerInfo, addrs = s.peerInfo.addrs
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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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# we want to report errors but we do not want to fail
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# or crash here, cos we need to clean possibly MANY items
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# and any following conn/transport won't be cleaned up
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if s.pubSub.isSome:
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await s.pubSub.get().stop()
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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"
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trace "switch stopped"
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proc subscribePeer*(s: Switch, peerInfo: PeerInfo) {.async, gcsafe.} =
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## Subscribe to pub sub peer
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if s.pubSub.isSome and not(s.pubSub.get().connected(peerInfo)):
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trace "about to subscribe to pubsub peer", peer = peerInfo.shortLog()
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var stream: Connection
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try:
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stream = await s.connManager.getMuxedStream(peerInfo)
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if isNil(stream):
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trace "unable to subscribe to peer", peer = peerInfo.shortLog
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return
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if not await s.ms.select(stream, s.pubSub.get().codec):
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if not(isNil(stream)):
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await stream.close()
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return
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s.pubSub.get().subscribePeer(stream)
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except CancelledError as exc:
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if not(isNil(stream)):
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await stream.close()
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raise exc
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except CatchableError as exc:
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trace "exception in subscribe to peer", peer = peerInfo.shortLog,
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exc = exc.msg
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if not(isNil(stream)):
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await stream.close()
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proc subscribe*(s: Switch, topic: string,
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handler: TopicHandler) {.async.} =
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## subscribe to a pubsub topic
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if s.pubSub.isNone:
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raise newNoPubSubException()
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await s.pubSub.get().subscribe(topic, handler)
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proc unsubscribe*(s: Switch, topics: seq[TopicPair]) {.async.} =
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## unsubscribe from topics
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if s.pubSub.isNone:
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raise newNoPubSubException()
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await s.pubSub.get().unsubscribe(topics)
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proc unsubscribeAll*(s: Switch, topic: string) {.async.} =
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## unsubscribe from topics
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if s.pubSub.isNone:
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raise newNoPubSubException()
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await s.pubSub.get().unsubscribeAll(topic)
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proc publish*(s: Switch, topic: string, data: seq[byte]): Future[int] {.async.} =
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# pubslish to pubsub topic
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if s.pubSub.isNone:
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raise newNoPubSubException()
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return await s.pubSub.get().publish(topic, data)
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proc addValidator*(s: Switch,
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topics: varargs[string],
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hook: ValidatorHandler) =
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# add validator
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if s.pubSub.isNone:
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raise newNoPubSubException()
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s.pubSub.get().addValidator(topics, hook)
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proc removeValidator*(s: Switch,
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topics: varargs[string],
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hook: ValidatorHandler) =
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# pubslish to pubsub topic
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if s.pubSub.isNone:
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raise newNoPubSubException()
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s.pubSub.get().removeValidator(topics, hook)
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proc muxerHandler(s: Switch, muxer: Muxer) {.async, gcsafe.} =
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var stream = await muxer.newStream()
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defer:
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if not(isNil(stream)):
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await stream.close()
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try:
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# once we got a muxed connection, attempt to
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# identify it
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await s.identify(stream)
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if isNil(stream.peerInfo):
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await muxer.close()
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return
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muxer.connection.peerInfo = stream.peerInfo
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# store incoming connection
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s.connManager.storeIncoming(muxer.connection)
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# store muxer and muxed connection
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s.connManager.storeMuxer(muxer)
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trace "got new muxer", peer = $muxer.connection.peerInfo
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# try establishing a pubsub connection
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await s.subscribePeer(muxer.connection.peerInfo)
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asyncCheck s.cleanupPubSubPeer(muxer.connection)
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except CancelledError as exc:
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await muxer.close()
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raise exc
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except CatchableError as exc:
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await muxer.close()
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libp2p_failed_upgrade.inc()
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trace "exception in muxer handler", exc = exc.msg
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proc newSwitch*(peerInfo: PeerInfo,
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transports: seq[Transport],
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identity: Identify,
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muxers: Table[string, MuxerProvider],
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secureManagers: openarray[Secure] = [],
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pubSub: Option[PubSub] = none(PubSub)): Switch =
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if secureManagers.len == 0:
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raise (ref CatchableError)(msg: "Provide at least one secure manager")
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result = Switch(
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peerInfo: peerInfo,
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ms: newMultistream(),
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transports: transports,
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connManager: ConnManager.init(),
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identity: identity,
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muxers: muxers,
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secureManagers: @secureManagers,
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)
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|
|
|
let s = result # can't capture result
|
|
result.streamHandler = proc(stream: Connection) {.async, gcsafe.} =
|
|
try:
|
|
trace "handling connection for", peerInfo = $stream
|
|
defer:
|
|
if not(isNil(stream)):
|
|
await stream.close()
|
|
await s.ms.handle(stream) # handle incoming connection
|
|
except CancelledError as exc:
|
|
raise exc
|
|
except CatchableError as exc:
|
|
trace "exception in stream handler", exc = exc.msg
|
|
|
|
result.mount(identity)
|
|
for key, val in muxers:
|
|
val.streamHandler = result.streamHandler
|
|
val.muxerHandler = proc(muxer: Muxer): Future[void] =
|
|
s.muxerHandler(muxer)
|
|
|
|
if pubSub.isSome:
|
|
result.pubSub = pubSub
|
|
result.mount(pubSub.get())
|