Autonat protocol (#739)

libp2p/builders.nim

@@ -26,7 +26,7 @@ import
   switch, peerid, peerinfo, stream/connection, multiaddress,
   crypto/crypto, transports/[transport, tcptransport],
   muxers/[muxer, mplex/mplex, yamux/yamux],
-  protocols/[identify, secure/secure, secure/noise],
+  protocols/[identify, secure/secure, secure/noise, autonat],
   protocols/relay/[relay, client, rtransport],
   connmanager, upgrademngrs/muxedupgrade,
   nameresolving/nameresolver,
@@ -58,6 +58,7 @@ type
     agentVersion: string
     nameResolver: NameResolver
     peerStoreCapacity: Option[int]
+    autonat: bool
     circuitRelay: Relay
 
 proc new*(T: type[SwitchBuilder]): T {.public.} =
@@ -185,6 +186,10 @@ proc withNameResolver*(b: SwitchBuilder, nameResolver: NameResolver): SwitchBuil
   b.nameResolver = nameResolver
   b
 
+proc withAutonat*(b: SwitchBuilder): SwitchBuilder =
+  b.autonat = true
+  b
+
 proc withCircuitRelay*(b: SwitchBuilder, r: Relay = Relay.new()): SwitchBuilder =
   b.circuitRelay = r
   b
@@ -246,6 +251,10 @@ proc build*(b: SwitchBuilder): Switch
     nameResolver = b.nameResolver,
     peerStore = peerStore)
 
+  if b.autonat:
+    let autonat = Autonat.new(switch)
+    switch.mount(autonat)
+
   if not isNil(b.circuitRelay):
     if b.circuitRelay of RelayClient:
       switch.addTransport(RelayTransport.new(RelayClient(b.circuitRelay), muxedUpgrade))

libp2p/dial.nim

@@ -58,3 +58,9 @@ method addTransport*(
   self: Dial,
   transport: Transport) {.base.} =
   doAssert(false, "Not implemented!")
+
+method tryDial*(
+  self: Dial,
+  peerId: PeerId,
+  addrs: seq[MultiAddress]): Future[MultiAddress] {.async, base.} =
+  doAssert(false, "Not implemented!")

libp2p/dialer.nim

@@ -21,6 +21,7 @@ import dial,
        stream/connection,
        transports/transport,
        nameresolving/nameresolver,
+       upgrademngrs/upgrade,
        errors
 
 export dial, errors
@@ -178,6 +179,27 @@ proc negotiateStream(
 
   return conn
 
+method tryDial*(
+  self: Dialer,
+  peerId: PeerId,
+  addrs: seq[MultiAddress]): Future[MultiAddress] {.async.} =
+  ## Create a protocol stream and in order to check
+  ## if a connection is possible.
+  ## Doesn't use the Connection Manager to save it.
+  ##
+
+  trace "Check if it can dial", peerId, addrs
+  try:
+    let conn = await self.dialAndUpgrade(peerId, addrs)
+    if conn.isNil():
+      raise newException(DialFailedError, "No valid multiaddress")
+    await conn.close()
+    return conn.observedAddr
+  except CancelledError as exc:
+    raise exc
+  except CatchableError as exc:
+    raise newException(DialFailedError, exc.msg)
+
 method dial*(
   self: Dialer,
   peerId: PeerId,

libp2p/multiaddress.nim

@@ -590,10 +590,28 @@ proc getPart(ma: MultiAddress, index: int): MaResult[MultiAddress] =
     inc(offset)
   ok(res)
 
+proc getParts[U, V](ma: MultiAddress, slice: HSlice[U, V]): MaResult[MultiAddress] =
+  when slice.a is BackwardsIndex or slice.b is BackwardsIndex:
+    let maLength = ? len(ma)
+  template normalizeIndex(index): int =
+    when index is BackwardsIndex: maLength - int(index)
+    else: int(index)
+  let
+    indexStart = normalizeIndex(slice.a)
+    indexEnd = normalizeIndex(slice.b)
+  var res: MultiAddress
+  for i in indexStart..indexEnd:
+    ? res.append(? ma[i])
+  ok(res)
+
 proc `[]`*(ma: MultiAddress, i: int): MaResult[MultiAddress] {.inline.} =
   ## Returns part with index ``i`` of MultiAddress ``ma``.
   ma.getPart(i)
 
+proc `[]`*(ma: MultiAddress, slice: HSlice): MaResult[MultiAddress] {.inline.} =
+  ## Returns parts with slice ``slice`` of MultiAddress ``ma``.
+  ma.getParts(slice)
+
 iterator items*(ma: MultiAddress): MaResult[MultiAddress] =
   ## Iterates over all addresses inside of MultiAddress ``ma``.
   var header: uint64
@@ -630,6 +648,13 @@ iterator items*(ma: MultiAddress): MaResult[MultiAddress] =
     res.data.finish()
     yield ok(MaResult[MultiAddress], res)
 
+proc len*(ma: MultiAddress): MaResult[int] =
+  var counter: int
+  for part in ma:
+    if part.isErr: return err(part.error)
+    counter.inc()
+  ok(counter)
+
 proc contains*(ma: MultiAddress, codec: MultiCodec): MaResult[bool] {.inline.} =
   ## Returns ``true``, if address with MultiCodec ``codec`` present in
   ## MultiAddress ``ma``.