Autonat protocol

libp2p/builders.nim

@@ -23,7 +23,7 @@ import
   switch, peerid, peerinfo, stream/connection, multiaddress,
   crypto/crypto, transports/[transport, tcptransport],
   muxers/[muxer, mplex/mplex, yamux/yamux],
-  protocols/[identify, secure/secure, secure/noise, relay],
+  protocols/[identify, secure/secure, secure/noise, relay, autonat],
   connmanager, upgrademngrs/muxedupgrade,
   nameresolving/nameresolver,
   errors, utility
@@ -58,6 +58,7 @@ type
     agentVersion: string
     nameResolver: NameResolver
     peerStoreCapacity: Option[int]
+    autonat: bool
     isCircuitRelay: bool
     circuitRelayCanHop: bool
 
@@ -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 withRelayTransport*(b: SwitchBuilder, canHop: bool): SwitchBuilder =
   b.isCircuitRelay = true
   b.circuitRelayCanHop = canHop
@@ -255,6 +260,10 @@ proc build*(b: SwitchBuilder): Switch
     nameResolver = b.nameResolver,
     peerStore = peerStore)
 
+  if b.autonat:
+    let autonat = Autonat.new(switch)
+    switch.mount(autonat)
+
   if b.isCircuitRelay:
     let relay = Relay.new(switch, b.circuitRelayCanHop)
     switch.mount(relay)

libp2p/dial.nim

@@ -55,3 +55,9 @@ 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
@@ -47,8 +48,7 @@ type
 proc dialAndUpgrade(
   self: Dialer,
   peerId: PeerId,
-  addrs: seq[MultiAddress],
-  forceDial: bool):
+  addrs: seq[MultiAddress]):
   Future[Connection] {.async.} =
   debug "Dialing peer", peerId
 
@@ -65,17 +65,7 @@ proc dialAndUpgrade(
           trace "Dialing address", address = $a, peerId, hostname
           let dialed = try:
               libp2p_total_dial_attempts.inc()
-              # await a connection slot when the total
-              # connection count is equal to `maxConns`
-              #
-              # Need to copy to avoid "cannot be captured" errors in Nim-1.4.x.
-              let
-                transportCopy = transport
-                addressCopy = a
-              await self.connManager.trackOutgoingConn(
-                () => transportCopy.dial(hostname, addressCopy),
-                forceDial
-              )
+              await transport.dial(hostname, a)
             except TooManyConnectionsError as exc:
               trace "Connection limit reached!"
               raise exc
@@ -139,7 +129,10 @@ proc internalConnect(
       trace "Reusing existing connection", conn, direction = $conn.dir
       return conn
 
-    conn = await self.dialAndUpgrade(peerId, addrs, forceDial)
+    conn = await self.connManager.trackOutgoingConn(
+      () => self.dialAndUpgrade(peerId, addrs),
+      forceDial
+    )
     if isNil(conn): # None of the addresses connected
       raise newException(DialFailedError, "Unable to establish outgoing link")
 
@@ -185,6 +178,27 @@ proc negotiateStream(
 
   return conn
 
+method tryDial*(
+  self: Dialer,
+  peerId: PeerId,
+  addrs: seq[MultiAddress]): Future[MultiAddress] {.raises: [Defect], 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

@@ -587,10 +587,28 @@ 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
@@ -627,6 +645,13 @@ 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``.