204 lines
6.8 KiB
Nim
204 lines
6.8 KiB
Nim
## Nim-LibP2P
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## Copyright (c) 2018 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, sequtils, options, strformat
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import chronos
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import connection,
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transports/transport,
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stream/lpstream,
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multistream,
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protocols/protocol,
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protocols/secure,
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peerinfo,
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multiaddress,
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protocols/identify,
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muxers/muxer,
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peer,
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helpers/debug
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type
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Switch* = ref object of RootObj
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peerInfo*: PeerInfo
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connections*: TableRef[string, Connection]
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muxed*: TableRef[string, Muxer]
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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*: MultisteamSelect
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identity*: Identify
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streamHandler*: StreamHandler
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secureManager*: Secure
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proc secure(s: Switch, conn: Connection): Future[Connection] {.async, gcsafe.} =
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## secure the incoming connection
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# plaintext for now, doesn't do anything
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if not (await s.ms.select(conn, s.secureManager.codec)):
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raise newException(CatchableError, "Unable to negotiate a secure channel!")
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result = conn
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proc identify(s: Switch, conn: Connection) {.async, gcsafe.} =
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## identify the connection
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# s.peerInfo.protocols = await s.ms.list(conn) # update protos before engagin in identify
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try:
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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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let id = if conn.peerInfo.isSome:
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conn.peerInfo.get().peerId.pretty
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else:
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""
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if id.len > 0 and s.connections.contains(id):
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let connection = s.connections[id]
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var peerInfo = conn.peerInfo.get()
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peerInfo.peerId = PeerID.init(info.pubKey) # we might not have a peerId at all
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peerInfo.addrs = info.addrs
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peerInfo.protocols = info.protos
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debug &"identify: identified remote peer {peerInfo.peerId.pretty}"
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except IdentityInvalidMsgError as exc:
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debug exc.msg
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except IdentityNoMatchError as exc:
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debug exc.msg
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proc mux(s: Switch, conn: Connection): Future[void] {.async, gcsafe.} =
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## mux incoming connection
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let muxers = toSeq(s.muxers.keys)
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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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return
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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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# do identify first, so that we have a
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# PeerInfo in case we didn't before
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let stream = await muxer.newStream()
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let handlerFut = muxer.handle()
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# add muxer handler cleanup proc
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handlerFut.addCallback(
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proc(udata: pointer = nil) {.gcsafe.} =
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if handlerFut.finished:
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debug &"Muxer handler completed for peer {conn.peerInfo.get().peerId.pretty}"
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)
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await s.identify(stream)
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await stream.close() # close idenity stream
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# store it in muxed connections if we have a peer for it
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# TODO: We should make sure that this are cleaned up properly
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# on exit even if there is no peer for it. This shouldn't
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# happen once secio is in place, but still something to keep
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# in mind
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if conn.peerInfo.isSome:
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s.muxed[conn.peerInfo.get().peerId.pretty] = muxer
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proc handleConn(s: Switch, conn: Connection): Future[Connection] {.async, gcsafe.} =
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result = conn
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## perform upgrade flow
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if result.peerInfo.isSome:
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let id = result.peerInfo.get().peerId.pretty
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if s.connections.contains(id):
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# if we already have a connection for this peer,
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# close the incoming connection and return the
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# existing one
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await result.close()
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return s.connections[id]
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s.connections[id] = result
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result = await s.secure(conn) # secure the connection
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await s.mux(result) # mux it if possible
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proc cleanupConn(s: Switch, conn: Connection) {.async, gcsafe.} =
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if conn.peerInfo.isSome:
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let id = conn.peerInfo.get().peerId.pretty
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if s.muxed.contains(id):
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await s.muxed[id].close
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if s.connections.contains(id):
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await s.connections[id].close()
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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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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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result = await t.dial(a)
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result.peerInfo = some(peer)
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result = await s.handleConn(result)
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# if there is a muxer for the connection
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# use it instead to create a muxed stream
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if s.muxed.contains(peer.peerId.pretty):
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result = await s.muxed[peer.peerId.pretty].newStream()
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debug &"dial: attempting to select remote proto {proto}"
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if not (await s.ms.select(result, proto)):
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debug &"dial: Unable to select protocol: {proto}"
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raise newException(CatchableError,
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&"Unable to select protocol: {proto}")
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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) {.async.} =
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proc handle(conn: Connection): Future[void] {.async, closure, gcsafe.} =
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try:
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if (await s.ms.select(conn)):
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await s.ms.handle(conn) # handle incoming connection
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except:
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await s.cleanupConn(conn)
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for t in s.transports: # for each transport
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for a in s.peerInfo.addrs:
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if t.handles(a): # check if it handles the multiaddr
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await t.listen(a, handle) # listen for incoming connections
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proc stop*(s: Switch) {.async.} =
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await allFutures(s.transports.mapIt(it.close()))
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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]): Switch =
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new result
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result.peerInfo = peerInfo
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result.ms = newMultistream()
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result.transports = transports
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result.connections = newTable[string, Connection]()
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result.muxed = newTable[string, Muxer]()
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result.identity = identity
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result.muxers = muxers
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let s = result # can't capture result
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result.streamHandler = proc(stream: Connection) {.async, gcsafe.} =
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# TODO: figure out proper way of handling this.
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# Perhaps it's ok to discard this Future and handle
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# errors elsewere?
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await s.ms.handle(stream) # handle incoming connection
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result.mount(identity)
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for key, val in muxers:
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val.streamHandler = result.streamHandler
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result.mount(val)
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result.secureManager = Secure(newPlainText())
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result.mount(result.secureManager)
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