Implement decoding and connection to onion peer:

make a separate a bit controversial class structure.OnionPeer(),
having .from_object() and .to_object() instead of .from_bytes() etc.

minode/connection.py

@@ -266,6 +266,7 @@ class ConnectionBase(threading.Thread):
         addr = {
             structure.NetAddr(c.remote_version.services, c.host, c.port)
             for c in shared.connections if c.network != 'i2p'
+            and not c.host.endswith('.onion')
             and c.server is False and c.status == 'fully_established'}
         # pylint: disable=unsubscriptable-object
         # https://github.com/pylint-dev/pylint/issues/3637
@@ -396,6 +397,9 @@ class ConnectionBase(threading.Thread):
             if not self.server:
                 self.send_queue.put('fully_established')
                 if self.network == 'ip':
+                    if self.host.endswith('.onion'):
+                        shared.onion_pool.add((self.host, self.port))
+                    else:
                         shared.address_advertise_queue.put(structure.NetAddr(
                             version.services, self.host, self.port))
                         shared.node_pool.add((self.host, self.port))
@@ -502,6 +506,13 @@ class Connection(ConnectionBase):
                     ' adding to i2p_unchecked_node_pool')
                 logging.debug(dest)
                 shared.i2p_unchecked_node_pool.add((dest, 'i2p'))
+            elif (
+                obj.object_type == shared.onion_obj_type
+                and obj.version == shared.onion_obj_version
+            ):
+                peer = structure.OnionPeer.from_object(obj)
+                logging.debug('Received onion peer object: %s', peer)
+                shared.onion_unchecked_pool.add((peer.host, peer.port))
             shared.vector_advertise_queue.put(obj.vector)
 
     def _process_msg_getdata(self, m):

minode/manager.py

@@ -96,15 +96,29 @@ class Manager(threading.Thread):
         ):
 
             if shared.ip_enabled:
-                if len(shared.unchecked_node_pool) > 16:
+                sample_length = 16
+                if shared.tor:
+                    if len(shared.onion_unchecked_pool) > 4:
                         to_connect.update(random.sample(
-                        tuple(shared.unchecked_node_pool), 16))
+                            tuple(shared.onion_unchecked_pool), 4))
+                    else:
+                        to_connect.update(shared.onion_unchecked_pool)
+                    shared.onion_unchecked_pool.difference_update(to_connect)
+                    if len(shared.onion_pool) > 2:
+                        to_connect.update(random.sample(
+                            tuple(shared.onion_pool), 2))
+                    else:
+                        to_connect.update(shared.onion_pool)
+                    sample_length = 8
+                if len(shared.unchecked_node_pool) > sample_length:
+                    to_connect.update(random.sample(
+                        tuple(shared.unchecked_node_pool), sample_length))
                 else:
                     to_connect.update(shared.unchecked_node_pool)
                 shared.unchecked_node_pool.difference_update(to_connect)
-                if len(shared.node_pool) > 8:
+                if len(shared.node_pool) > sample_length / 2:
                     to_connect.update(random.sample(
-                        tuple(shared.node_pool), 8))
+                        tuple(shared.node_pool), int(sample_length / 2)))
                 else:
                     to_connect.update(shared.node_pool)
 
@@ -185,6 +199,17 @@ class Manager(threading.Thread):
             logging.warning(
                 'Error while loading nodes from disk.', exc_info=True)
 
+        try:
+            with open(
+                os.path.join(shared.data_directory, 'onion_nodes.pickle'), 'br'
+            ) as src:
+                shared.onion_pool = pickle.load(src)
+        except FileNotFoundError:
+            pass
+        except Exception:
+            logging.warning(
+                'Error while loading nodes from disk.', exc_info=True)
+
         with open(
             os.path.join(shared.source_directory, 'core_nodes.csv'),
             'r', newline='', encoding='ascii'
@@ -230,6 +255,13 @@ class Manager(threading.Thread):
             shared.i2p_unchecked_node_pool = set(random.sample(
                 tuple(shared.i2p_unchecked_node_pool), 100))
 
+        if len(shared.onion_pool) > 1000:
+            shared.onion_pool = set(
+                random.sample(shared.onion_pool, 1000))
+        if len(shared.onion_unchecked_pool) > 100:
+            shared.onion_unchecked_pool = set(
+                random.sample(shared.onion_unchecked_pool, 100))
+
         try:
             with open(
                 os.path.join(shared.data_directory, 'nodes.pickle'), 'bw'
@@ -239,6 +271,10 @@ class Manager(threading.Thread):
                 os.path.join(shared.data_directory, 'i2p_nodes.pickle'), 'bw'
             ) as dst:
                 pickle.dump(shared.i2p_node_pool, dst, protocol=3)
+            with open(
+                os.path.join(shared.data_directory, 'onion_nodes.pickle'), 'bw'
+            ) as dst:
+                pickle.dump(shared.onion_pool, dst, protocol=3)
             logging.debug('Saved nodes')
         except Exception:
             logging.warning('Error while saving nodes', exc_info=True)

minode/shared.py

@@ -26,6 +26,8 @@ timeout = 600
 header_length = 24
 i2p_dest_obj_type = 0x493250
 i2p_dest_obj_version = 1
+onion_obj_type = 0x746f72
+onion_obj_version = 3
 
 socks_proxy = None
 tor = False
@@ -62,6 +64,9 @@ i2p_core_nodes = set()
 i2p_node_pool = set()
 i2p_unchecked_node_pool = set()
 
+onion_pool = set()
+onion_unchecked_pool = set()
+
 outgoing_connections = 8
 connection_limit = 250
 

minode/structure.py

@@ -1,8 +1,10 @@
 # -*- coding: utf-8 -*-
 """Protocol structures"""
 import base64
+import binascii
 import hashlib
 import logging
+import re
 import socket
 import struct
 import time
@@ -208,3 +210,39 @@ class NetAddr():
         stream, net_addr = struct.unpack('>QI26s', b)[1:]
         n = NetAddrNoPrefix.from_bytes(net_addr)
         return cls(n.services, n.host, n.port, stream)
+
+
+class OnionPeer():
+    def __init__(self, host, port=8444, stream=None, dest_pub=None):
+        self.stream = stream or shared.stream
+        self.host = host
+        self.port = port
+        try:
+            self.dest_pub = dest_pub or base64.b32decode(
+                re.search(r'(.*)\.onion', host).groups()[0], True)
+        except (AttributeError, binascii.Error) as e:
+            raise ValueError('Malformed hostname') from e
+
+    def __repr__(self):
+        return 'onion_peer, stream: {}, host: {}, port {}'.format(
+            self.stream, self.host, self.port)
+
+    def to_object(self):
+        payload = b''
+        payload += VarInt(self.port).to_bytes()
+        payload += b'\xfd\x87\xd8\x7e\xeb\x43'
+        payload += self.dest_pub
+        return Object(
+            b'\x00' * 8, int(time.time() + 8 * 3600), shared.onion_obj_type,
+            shared.onion_obj_version, self.stream, payload)
+
+    @classmethod
+    def from_object(cls, obj):
+        payload = obj.object_payload
+        port_length = VarInt.length(payload[0])
+        port = VarInt.from_bytes(payload[:port_length]).n
+        if payload[port_length:port_length + 6] != b'\xfd\x87\xd8\x7e\xeb\x43':
+            raise ValueError('Malformed onion peer object')
+        dest_pub = payload[port_length + 6:]
+        host = base64.b32encode(dest_pub).lower().decode() + '.onion'
+        return cls(host, port, obj.stream_number, dest_pub)