nim-libp2p/libp2p/transports/tcptransport.nim

203 lines
5.7 KiB
Nim

## Nim-LibP2P
## Copyright (c) 2019 Status Research & Development GmbH
## Licensed under either of
## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
## * MIT license ([LICENSE-MIT](LICENSE-MIT))
## at your option.
## This file may not be copied, modified, or distributed except according to
## those terms.
import std/[oids, sequtils]
import chronos, chronicles
import transport,
../errors,
../wire,
../multiaddress,
../multicodec,
../stream/connection,
../stream/chronosstream
logScope:
topics = "tcptransport"
const
TcpTransportTrackerName* = "libp2p.tcptransport"
type
TcpTransport* = ref object of Transport
server*: StreamServer
clients: array[Direction, seq[StreamTransport]]
flags: set[ServerFlags]
TcpTransportTracker* = ref object of TrackerBase
opened*: uint64
closed*: uint64
proc setupTcpTransportTracker(): TcpTransportTracker {.gcsafe.}
proc getTcpTransportTracker(): TcpTransportTracker {.gcsafe.} =
result = cast[TcpTransportTracker](getTracker(TcpTransportTrackerName))
if isNil(result):
result = setupTcpTransportTracker()
proc dumpTracking(): string {.gcsafe.} =
var tracker = getTcpTransportTracker()
result = "Opened tcp transports: " & $tracker.opened & "\n" &
"Closed tcp transports: " & $tracker.closed
proc leakTransport(): bool {.gcsafe.} =
var tracker = getTcpTransportTracker()
result = (tracker.opened != tracker.closed)
proc setupTcpTransportTracker(): TcpTransportTracker =
result = new TcpTransportTracker
result.opened = 0
result.closed = 0
result.dump = dumpTracking
result.isLeaked = leakTransport
addTracker(TcpTransportTrackerName, result)
proc connHandler*(t: TcpTransport,
client: StreamTransport,
dir: Direction): Future[Connection] {.async.} =
debug "Handling tcp connection", address = $client.remoteAddress,
dir = $dir,
clients = t.clients[Direction.In].len +
t.clients[Direction.Out].len
let conn = Connection(
ChronosStream.init(
client,
dir
))
proc onClose() {.async.} =
try:
await client.join() or conn.join()
trace "Cleaning up client", addrs = $client.remoteAddress,
conn
if not(isNil(conn) and conn.closed()):
await conn.close()
t.clients[dir].keepItIf( it != client )
if not(isNil(client) and client.closed()):
await client.closeWait()
trace "Cleaned up client", addrs = $client.remoteAddress,
conn
except CatchableError as exc:
let useExc {.used.} = exc
debug "Error cleaning up client", errMsg = exc.msg, conn
t.clients[dir].add(client)
asyncSpawn onClose()
try:
conn.observedAddr = MultiAddress.init(client.remoteAddress).tryGet()
except CatchableError as exc:
trace "Connection setup failed", exc = exc.msg, conn
if not(isNil(client) and client.closed):
await client.closeWait()
raise exc
return conn
proc init*(T: type TcpTransport,
flags: set[ServerFlags] = {}): T =
result = T(flags: flags)
result.initTransport()
method initTransport*(t: TcpTransport) =
t.multicodec = multiCodec("tcp")
inc getTcpTransportTracker().opened
method start*(t: TcpTransport, ma: MultiAddress) {.async.} =
## listen on the transport
##
if t.running:
trace "TCP transport already running"
return
await procCall Transport(t).start(ma)
trace "Starting TCP transport"
t.server = createStreamServer(t.ma, t.flags, t)
# always get the resolved address in case we're bound to 0.0.0.0:0
t.ma = MultiAddress.init(t.server.sock.getLocalAddress()).tryGet()
t.running = true
trace "Listening on", address = t.ma
method stop*(t: TcpTransport) {.async, gcsafe.} =
## stop the transport
##
try:
trace "Stopping TCP transport"
await procCall Transport(t).stop() # call base
checkFutures(
await allFinished(
t.clients[Direction.In].mapIt(it.closeWait()) &
t.clients[Direction.Out].mapIt(it.closeWait())))
# server can be nil
if not isNil(t.server):
await t.server.closeWait()
t.server = nil
trace "Transport stopped"
inc getTcpTransportTracker().closed
except CatchableError as exc:
trace "Error shutting down tcp transport", exc = exc.msg
finally:
t.running = false
method accept*(t: TcpTransport): Future[Connection] {.async, gcsafe.} =
## accept a new TCP connection
##
if not t.running:
raise newTransportClosedError()
try:
let transp = await t.server.accept()
return await t.connHandler(transp, Direction.In)
except TransportOsError as exc:
# TODO: it doesn't sound like all OS errors
# can be ignored, we should re-raise those
# that can't.
debug "OS Error", exc = exc.msg
except TransportTooManyError as exc:
warn "Too many files opened", exc = exc.msg
except TransportUseClosedError as exc:
info "Server was closed", exc = exc.msg
raise newTransportClosedError(exc)
except CatchableError as exc:
trace "Unexpected error creating connection", exc = exc.msg
raise exc
method dial*(t: TcpTransport,
address: MultiAddress):
Future[Connection] {.async, gcsafe.} =
## dial a peer
##
trace "Dialing remote peer", address = $address
let transp = await connect(address)
return await t.connHandler(transp, Direction.Out)
method handles*(t: TcpTransport, address: MultiAddress): bool {.gcsafe.} =
if procCall Transport(t).handles(address):
return address.protocols
.tryGet()
.filterIt( it == multiCodec("tcp") )
.len > 0