Connect to unsynced peers, and trinity peers

Trinity peers were not communicating DAO headers during handshake, so
trinity would not connect to another trinity node. Solution was to
immediately add peer to pool during boot, and then kick it back out if
it fails the DAO check.

We were previously failing any peer who couldn't answer with the DAO
fork header. That means that unsynced peers would be rejected. Modified
to accept unsynced peers for now.

Author: carver

p2p/peer_pool.py

@@ -242,12 +242,16 @@ def unsubscribe(self, subscriber: PeerSubscriber) -> None:
     async def start_peer(self, peer: BasePeer) -> None:
         self.run_child_service(peer)
         await self.wait(peer.events.started.wait(), timeout=1)
+        if peer.is_operational:
+            self._add_peer(peer, ())
+        else:
+            self.logger.debug("%s was cancelled immediately, not adding to pool", peer)
+
         try:
-            with peer.collect_sub_proto_messages() as buffer:
-                await self.wait(
-                    peer.boot_manager.events.finished.wait(),
-                    timeout=self._peer_boot_timeout
-                )
+            await self.wait(
+                peer.boot_manager.events.finished.wait(),
+                timeout=self._peer_boot_timeout
+            )
         except TimeoutError as err:
             self.logger.debug('Timout waiting for peer to boot: %s', err)
             await peer.disconnect(DisconnectReason.timeout)
@@ -256,10 +260,8 @@ async def start_peer(self, peer: BasePeer) -> None:
             await self.connection_tracker.record_failure(peer.remote, err)
             raise
         else:
-            if peer.is_operational:
-                self._add_peer(peer, buffer.get_messages())
-            else:
-                self.logger.debug('%s disconnected during boot-up, not adding to pool', peer)
+            if not peer.is_operational:
+                self.logger.debug('%s disconnected during boot-up, dropped from pool', peer)
 
     def _add_peer(self,
                   peer: BasePeer,

trinity/protocol/common/boot.py

@@ -62,9 +62,11 @@ async def ensure_same_side_on_dao_fork(self) -> None:
                 ) from err
 
             if len(headers) != 2:
-                raise DAOForkCheckFailure(
-                    f"{self.peer} failed to return DAO fork check headers"
+                self.logger.debug(
+                    f"{self.peer} returned only {headers!r} at DAO fork. "
+                    "Assuming peer is syncing, for now..."
                 )
+                return
             else:
                 parent, header = headers