Merge pull request #324 from aratz-lasa/issue-280

Implemented Host that includes a routing system.

libp2p/__init__.py

@@ -4,6 +4,8 @@ from typing import Sequence
 from libp2p.crypto.keys import KeyPair
 from libp2p.crypto.rsa import create_new_key_pair
 from libp2p.host.basic_host import BasicHost
+from libp2p.host.host_interface import IHost
+from libp2p.host.routed_host import RoutedHost
 from libp2p.kademlia.network import KademliaServer
 from libp2p.kademlia.storage import IStorage
 from libp2p.network.network_interface import INetwork
@@ -106,7 +108,7 @@ def initialize_default_swarm(
 
     peerstore = peerstore_opt or PeerStore()
     # TODO: Initialize discovery if not presented
-    return Swarm(id_opt, peerstore, upgrader, transport, disc_opt)
+    return Swarm(id_opt, peerstore, upgrader, transport)
 
 
 async def new_node(
@@ -117,7 +119,7 @@ async def new_node(
     sec_opt: TSecurityOptions = None,
     peerstore_opt: IPeerStore = None,
     disc_opt: IPeerRouting = None,
-) -> BasicHost:
+) -> IHost:
     """
     create new libp2p node
     :param key_pair: key pair for deriving an identity
@@ -149,6 +151,10 @@ async def new_node(
 
     # TODO enable support for other host type
     # TODO routing unimplemented
+    host: IHost  # If not explicitly typed, MyPy raises error
+    if disc_opt:
+        host = RoutedHost(swarm_opt, disc_opt)
+    else:
         host = BasicHost(swarm_opt)
 
     # Kick off cleanup job

libp2p/host/basic_host.py

@@ -13,7 +13,6 @@ from libp2p.protocol_muxer.exceptions import MultiselectClientError, Multiselect
 from libp2p.protocol_muxer.multiselect import Multiselect
 from libp2p.protocol_muxer.multiselect_client import MultiselectClient
 from libp2p.protocol_muxer.multiselect_communicator import MultiselectCommunicator
-from libp2p.routing.kademlia.kademlia_peer_router import KadmeliaPeerRouter
 from libp2p.typing import StreamHandlerFn, TProtocol
 
 from .host_interface import IHost
@@ -34,16 +33,14 @@ class BasicHost(IHost):
     """
 
     _network: INetwork
-    _router: KadmeliaPeerRouter
     peerstore: IPeerStore
 
     multiselect: Multiselect
     multiselect_client: MultiselectClient
 
-    def __init__(self, network: INetwork, router: KadmeliaPeerRouter = None) -> None:
+    def __init__(self, network: INetwork) -> None:
         self._network = network
         self._network.set_stream_handler(self._swarm_stream_handler)
-        self._router = router
         self.peerstore = self._network.peerstore
         # Protocol muxing
         self.multiselect = Multiselect()

libp2p/host/routed_host.py

@@ -0,0 +1,40 @@
+from libp2p.host.basic_host import BasicHost
+from libp2p.host.exceptions import ConnectionFailure
+from libp2p.network.network_interface import INetwork
+from libp2p.peer.peerinfo import PeerInfo
+from libp2p.routing.interfaces import IPeerRouting
+
+
+# RoutedHost is a p2p Host that includes a routing system.
+# This allows the Host to find the addresses for peers when it does not have them.
+class RoutedHost(BasicHost):
+    _router: IPeerRouting
+
+    def __init__(self, network: INetwork, router: IPeerRouting):
+        super().__init__(network)
+        self._router = router
+
+    async def connect(self, peer_info: PeerInfo) -> None:
+        """
+        connect ensures there is a connection between this host and the peer with
+        given `peer_info.peer_id`. See (basic_host).connect for more information.
+
+        RoutedHost's Connect differs in that if the host has no addresses for a
+        given peer, it will use its routing system to try to find some.
+
+        :param peer_info: peer_info of the peer we want to connect to
+        :type peer_info: peer.peerinfo.PeerInfo
+        """
+        # check if we were given some addresses, otherwise, find some with the routing system.
+        if not peer_info.addrs:
+            found_peer_info = await self._router.find_peer(peer_info.peer_id)
+            if not found_peer_info:
+                raise ConnectionFailure("Unable to find Peer address")
+            self.peerstore.add_addrs(peer_info.peer_id, found_peer_info.addrs, 10)
+        self.peerstore.add_addrs(peer_info.peer_id, peer_info.addrs, 10)
+
+        # there is already a connection to this peer
+        if peer_info.peer_id in self._network.connections:
+            return
+
+        await self._network.dial_peer(peer_info.peer_id)

libp2p/network/swarm.py

@@ -8,7 +8,6 @@ from libp2p.network.connection.net_connection_interface import INetConn
 from libp2p.peer.id import ID
 from libp2p.peer.peerstore import PeerStoreError
 from libp2p.peer.peerstore_interface import IPeerStore
-from libp2p.routing.interfaces import IPeerRouting
 from libp2p.stream_muxer.abc import IMuxedConn
 from libp2p.transport.exceptions import (
     MuxerUpgradeFailure,
@@ -36,7 +35,6 @@ class Swarm(INetwork):
     peerstore: IPeerStore
     upgrader: TransportUpgrader
     transport: ITransport
-    router: IPeerRouting
     # TODO: Connection and `peer_id` are 1-1 mapping in our implementation,
     #   whereas in Go one `peer_id` may point to multiple connections.
     connections: Dict[ID, INetConn]
@@ -51,13 +49,11 @@ class Swarm(INetwork):
         peerstore: IPeerStore,
         upgrader: TransportUpgrader,
         transport: ITransport,
-        router: IPeerRouting,
     ):
         self.self_id = peer_id
         self.peerstore = peerstore
         self.upgrader = upgrader
         self.transport = transport
-        self.router = router
         self.connections = dict()
         self.listeners = dict()
 
@@ -96,10 +92,7 @@ class Swarm(INetwork):
         if not addrs:
             raise SwarmException(f"No known addresses to peer {peer_id}")
 
-        if not self.router:
         multiaddr = addrs[0]
-        else:
-            multiaddr = self.router.find_peer(peer_id)
         # Dial peer (connection to peer does not yet exist)
         # Transport dials peer (gets back a raw conn)
         try:
@@ -232,9 +225,6 @@ class Swarm(INetwork):
         # No maddr succeeded
         return False
 
-    def add_router(self, router: IPeerRouting) -> None:
-        self.router = router
-
     async def close(self) -> None:
         # TODO: Prevent from new listeners and conns being added.
         #   Reference: https://github.com/libp2p/go-libp2p-swarm/blob/8be680aef8dea0a4497283f2f98470c2aeae6b65/swarm.go#L124-L134  # noqa: E501

libp2p/peer/peerinfo.py

@@ -1,4 +1,4 @@
-from typing import List, Sequence
+from typing import Any, List, Sequence
 
 import multiaddr
 
@@ -6,7 +6,6 @@ from .id import ID
 
 
 class PeerInfo:
-
     peer_id: ID
     addrs: List[multiaddr.Multiaddr]
 
@@ -14,6 +13,13 @@ class PeerInfo:
         self.peer_id = peer_id
         self.addrs = list(addrs)
 
+    def __eq__(self, other: Any) -> bool:
+        return (
+            isinstance(other, PeerInfo)
+            and self.peer_id == other.peer_id
+            and self.addrs == other.addrs
+        )
+
 
 def info_from_p2p_addr(addr: multiaddr.Multiaddr) -> PeerInfo:
     if not addr:

libp2p/routing/kademlia/kademlia_peer_router.py

@@ -1,42 +1,42 @@
-import ast
+import json
-from typing import Union
+
+import multiaddr
 
-from libp2p.kademlia.kad_peerinfo import KadPeerInfo, create_kad_peerinfo
 from libp2p.kademlia.network import KademliaServer
 from libp2p.peer.id import ID
+from libp2p.peer.peerinfo import PeerInfo
 from libp2p.routing.interfaces import IPeerRouting
 
 
 class KadmeliaPeerRouter(IPeerRouting):
-
     server: KademliaServer
 
     def __init__(self, dht_server: KademliaServer) -> None:
         self.server = dht_server
 
-    async def find_peer(self, peer_id: ID) -> KadPeerInfo:
+    async def find_peer(self, peer_id: ID) -> PeerInfo:
         """
         Find a specific peer
         :param peer_id: peer to search for
-        :return: KadPeerInfo of specified peer
+        :return: PeerInfo of specified peer
         """
         # switching peer_id to xor_id used by kademlia as node_id
         xor_id = peer_id.xor_id
         # ignore type for kad
         value = await self.server.get(xor_id)  # type: ignore
-        return decode_peerinfo(value)
+        return (
+            peer_info_from_str(value) if value else None
+        )  # TODO: should raise error if None?
 
 
-def decode_peerinfo(encoded: Union[bytes, str]) -> KadPeerInfo:
+def peer_info_to_str(peer_info: PeerInfo) -> str:
-    if isinstance(encoded, bytes):
+    return json.dumps(
-        encoded = encoded.decode()
+        [peer_info.peer_id.to_string(), list(map(lambda a: str(a), peer_info.addrs))]
-    try:
+    )
-        lines = ast.literal_eval(encoded)
+
-    except SyntaxError:
+
-        return None
+def peer_info_from_str(string: str) -> PeerInfo:
-    ip = lines[1]
+    peer_id, raw_addrs = json.loads(string)
-    port = lines[2]
+    return PeerInfo(
-    peer_id = lines[3]
+        ID.from_base58(peer_id), list(map(lambda a: multiaddr.Multiaddr(a), raw_addrs))
-    # ignore typing for kad
+    )
-    peer_info = create_kad_peerinfo(peer_id, ip, port)  # type: ignore
-    return peer_info

tests/host/test_routed_host.py

@@ -0,0 +1,74 @@
+import asyncio
+
+import pytest
+
+from libp2p.host.exceptions import ConnectionFailure
+from libp2p.peer.peerinfo import PeerInfo
+from libp2p.routing.kademlia.kademlia_peer_router import peer_info_to_str
+from tests.utils import (
+    set_up_nodes_by_transport_and_disc_opt,
+    set_up_nodes_by_transport_opt,
+    set_up_routers,
+)
+
+
+@pytest.mark.asyncio
+async def test_host_routing_success():
+    routers = await set_up_routers([5678, 5679])
+    transports = [["/ip4/127.0.0.1/tcp/0"], ["/ip4/127.0.0.1/tcp/0"]]
+    transport_disc_opt_list = zip(transports, routers)
+    (host_a, host_b) = await set_up_nodes_by_transport_and_disc_opt(
+        transport_disc_opt_list
+    )
+
+    # Set routing info
+    await routers[0].server.set(
+        host_a.get_id().xor_id,
+        peer_info_to_str(PeerInfo(host_a.get_id(), host_a.get_addrs())),
+    )
+    await routers[1].server.set(
+        host_b.get_id().xor_id,
+        peer_info_to_str(PeerInfo(host_b.get_id(), host_b.get_addrs())),
+    )
+
+    # forces to use routing as no addrs are provided
+    await host_a.connect(PeerInfo(host_b.get_id(), []))
+    await host_b.connect(PeerInfo(host_a.get_id(), []))
+
+    # Clean up
+    await asyncio.gather(*[host_a.close(), host_b.close()])
+    routers[0].server.stop()
+    routers[1].server.stop()
+
+
+@pytest.mark.asyncio
+async def test_host_routing_fail():
+    routers = await set_up_routers([5678, 5679])
+    transports = [["/ip4/127.0.0.1/tcp/0"], ["/ip4/127.0.0.1/tcp/0"]]
+    transport_disc_opt_list = zip(transports, routers)
+    (host_a, host_b) = await set_up_nodes_by_transport_and_disc_opt(
+        transport_disc_opt_list
+    )
+
+    host_c = (await set_up_nodes_by_transport_opt([["/ip4/127.0.0.1/tcp/0"]]))[0]
+
+    # Set routing info
+    await routers[0].server.set(
+        host_a.get_id().xor_id,
+        peer_info_to_str(PeerInfo(host_a.get_id(), host_a.get_addrs())),
+    )
+    await routers[1].server.set(
+        host_b.get_id().xor_id,
+        peer_info_to_str(PeerInfo(host_b.get_id(), host_b.get_addrs())),
+    )
+
+    # routing fails because host_c does not use routing
+    with pytest.raises(ConnectionFailure):
+        await host_a.connect(PeerInfo(host_c.get_id(), []))
+    with pytest.raises(ConnectionFailure):
+        await host_b.connect(PeerInfo(host_c.get_id(), []))
+
+    # Clean up
+    await asyncio.gather(*[host_a.close(), host_b.close(), host_c.close()])
+    routers[0].server.stop()
+    routers[1].server.stop()

tests/routing/test_kad_peer_router.py

@@ -2,7 +2,10 @@ import pytest
 
 from libp2p.kademlia.network import KademliaServer
 from libp2p.peer.id import ID
-from libp2p.routing.kademlia.kademlia_peer_router import KadmeliaPeerRouter
+from libp2p.routing.kademlia.kademlia_peer_router import (
+    KadmeliaPeerRouter,
+    peer_info_to_str,
+)
 
 
 @pytest.mark.asyncio
@@ -15,11 +18,11 @@ async def test_simple_two_nodes():
 
     node_a_value = await node_b.bootstrap([("127.0.0.1", 5678)])
     node_a_kad_peerinfo = node_a_value[0]
-    await node_a.set(node_a_kad_peerinfo.xor_id, repr(node_a_kad_peerinfo))
+    await node_a.set(node_a_kad_peerinfo.xor_id, peer_info_to_str(node_a_kad_peerinfo))
 
     router = KadmeliaPeerRouter(node_b)
     returned_info = await router.find_peer(ID(node_a_kad_peerinfo.peer_id_bytes))
-    assert repr(returned_info) == repr(node_a_kad_peerinfo)
+    assert returned_info == node_a_kad_peerinfo
 
 
 @pytest.mark.asyncio
@@ -37,11 +40,11 @@ async def test_simple_three_nodes():
     node_a_kad_peerinfo = node_a_value[0]
 
     await node_c.bootstrap([("127.0.0.1", 5702)])
-    await node_a.set(node_a_kad_peerinfo.xor_id, repr(node_a_kad_peerinfo))
+    await node_a.set(node_a_kad_peerinfo.xor_id, peer_info_to_str(node_a_kad_peerinfo))
 
     router = KadmeliaPeerRouter(node_c)
     returned_info = await router.find_peer(ID(node_a_kad_peerinfo.peer_id_bytes))
-    assert str(returned_info) == str(node_a_kad_peerinfo)
+    assert returned_info == node_a_kad_peerinfo
 
 
 @pytest.mark.asyncio
@@ -65,8 +68,8 @@ async def test_simple_four_nodes():
 
     await node_d.bootstrap([("127.0.0.1", 5803)])
 
-    await node_b.set(node_a_kad_peerinfo.xor_id, repr(node_a_kad_peerinfo))
+    await node_b.set(node_a_kad_peerinfo.xor_id, peer_info_to_str(node_a_kad_peerinfo))
 
     router = KadmeliaPeerRouter(node_d)
     returned_info = await router.find_peer(ID(node_a_kad_peerinfo.peer_id_bytes))
-    assert str(returned_info) == str(node_a_kad_peerinfo)
+    assert returned_info == node_a_kad_peerinfo

tests/utils.py

@@ -1,7 +1,9 @@
 import multiaddr
 
 from libp2p import new_node
+from libp2p.kademlia.network import KademliaServer
 from libp2p.peer.peerinfo import info_from_p2p_addr
+from libp2p.routing.kademlia.kademlia_peer_router import KadmeliaPeerRouter
 from tests.constants import MAX_READ_LEN
 
 
@@ -36,6 +38,29 @@ async def set_up_nodes_by_transport_opt(transport_opt_list):
     return tuple(nodes_list)
 
 
+async def set_up_nodes_by_transport_and_disc_opt(transport_disc_opt_list):
+    nodes_list = []
+    for transport_opt, disc_opt in transport_disc_opt_list:
+        node = await new_node(transport_opt=transport_opt, disc_opt=disc_opt)
+        await node.get_network().listen(multiaddr.Multiaddr(transport_opt[0]))
+        nodes_list.append(node)
+    return tuple(nodes_list)
+
+
+async def set_up_routers(router_confs):
+    bootstrap_node = KademliaServer()
+    await bootstrap_node.listen(router_confs[0])
+
+    routers = [KadmeliaPeerRouter(bootstrap_node)]
+    for port in router_confs[1:]:
+        node = KademliaServer()
+        await node.listen(port)
+
+        await node.bootstrap_node(("127.0.0.1", router_confs[0]))
+        routers.append(KadmeliaPeerRouter(node))
+    return routers
+
+
 async def echo_stream_handler(stream):
     while True:
         read_string = (await stream.read(MAX_READ_LEN)).decode()