Takers: filter out makers with many offers

joinmarket/configure.py

@@ -60,6 +60,7 @@ def __getitem__(self, key):
 global_singleton.ordername_list = ['absoffer', 'reloffer']
 global_singleton.commitment_broadcast_list = ['hp2']
 global_singleton.maker_timeout_sec = 60
+global_singleton.max_maker_offers_allowed = 5
 global_singleton.debug_file_lock = threading.Lock()
 global_singleton.debug_file_handle = None
 global_singleton.blacklist_file_lock = threading.Lock()
@@ -131,6 +132,11 @@ def jm_single():
 # responsive. Should be an integer >=2 for privacy, or set to 0 if you
 # want to disallow any reduction from your chosen number of makers.
 minimum_makers = 2
+# For takers: to filter out potentially malicious makers, this is
+# the maximum number of offers a maker is allowed to have. If a
+# makers has more offers, then he will be disregarded as potential
+# counterparty for coinjoins
+max_maker_offers_allowed = 5
 # the fee estimate is based on a projection of how many satoshis
 # per kB are needed to get in one of the next N blocks, N set here
 # as the value of 'tx_fees'. This estimate is high if you set N=2,
@@ -348,6 +354,13 @@ def load_program_config():
         log.info('TIMEOUT/maker_timeout_sec not found in .cfg file, '
                   'using default value')
 
+    try:
+        global_singleton.max_maker_offers_allowed = global_singleton.config.getint(
+            'POLICY', 'max_maker_offers_allowed')
+    except NoOptionError:
+        log.info('POLICY/max_maker_offers_allowed not found in .cfg file, '
+                  'using default value')
+
     # configure the interface to the blockchain on startup
     global_singleton.bc_interface = get_blockchain_interface_instance(
         global_singleton.config)

joinmarket/support.py

@@ -381,6 +381,17 @@ def calc_zero_change_cj_amount(ordercombo):
     return result, cj_amount, total_fee
 
 
+def remove_makers_with_too_many_offers(db, number_allowed_offers):
+    # removes makers with more than the number of allowed offers
+    crows = db.execute(
+        'SELECT DISTINCT counterparty FROM orderbook WHERE oid >= ?;', (int(number_allowed_offers),)).fetchall()
+
+    for row in crows:
+        nick = row["counterparty"]
+        db.execute('DELETE FROM orderbook WHERE counterparty=?;', (nick,))
+        log.debug('The following maker had too many offers and was removed: ' + nick)
+
+
 def debug_dump_object(obj, skip_fields=None):
     if skip_fields is None:
         skip_fields = []

patientsendpayment.py

@@ -11,6 +11,7 @@
 from joinmarket import validate_address, jm_single, get_p2pk_vbyte
 from joinmarket import get_log, choose_orders, weighted_order_choose, \
     debug_dump_object, sync_wallet
+from joinmarket.support import remove_makers_with_too_many_offers
 from joinmarket import Wallet
 
 import bitcoin as btc
@@ -46,6 +47,11 @@ def __init__(self, tmaker):
         self.ignored_makers = []
 
     def create_tx(self):
+        log.info('Removing makers with more than ' +
+            str(jm_single().config.getint("POLICY", "max_maker_offers_allowed")) +
+            ' offers as configured in joinmarket.cfg')
+        remove_makers_with_too_many_offers(self.tmaker.db,
+            jm_single().config.getint("POLICY", "max_maker_offers_allowed"))
         crow = self.tmaker.db.execute(
             'SELECT COUNT(DISTINCT counterparty) FROM orderbook;').fetchone()
         counterparty_count = crow['COUNT(DISTINCT counterparty)']

sendpayment.py

@@ -15,6 +15,7 @@
 from joinmarket import validate_address, jm_single
 from joinmarket import get_log, choose_sweep_orders, choose_orders, \
     pick_order, cheapest_order_choose, weighted_order_choose, debug_dump_object
+from joinmarket.support import remove_makers_with_too_many_offers
 from joinmarket import Wallet, BitcoinCoreWallet, sync_wallet
 from joinmarket.wallet import estimate_tx_fee
 
@@ -101,6 +102,10 @@ def __init__(self, taker):
         self.ignored_makers = []
 
     def create_tx(self):
+        log.info('Removing makers with more than ' +
+                 str(jm_single().config.getint("POLICY", "max_maker_offers_allowed")) +
+                 ' offers as configured in joinmarket.cfg')
+        remove_makers_with_too_many_offers(self.taker.db, jm_single().config.getint("POLICY", "max_maker_offers_allowed"))
         crow = self.taker.db.execute(
             'SELECT COUNT(DISTINCT counterparty) FROM orderbook;').fetchone()
         counterparty_count = crow['COUNT(DISTINCT counterparty)']

tumbler.py

@@ -17,6 +17,7 @@
 from joinmarket import get_log, rand_norm_array, rand_pow_array, \
     rand_exp_array, choose_orders, weighted_order_choose, choose_sweep_orders, \
     debug_dump_object, get_irc_mchannels
+from joinmarket.support import remove_makers_with_too_many_offers
 from joinmarket import Wallet
 from joinmarket.wallet import estimate_tx_fee
 
@@ -178,6 +179,11 @@ def tumbler_choose_orders(self,
         if active_nicks is None:
             active_nicks = []
         self.ignored_makers += nonrespondants
+        log.info('Removing makers with more than ' +
+            str(jm_single().config.getint("POLICY", "max_maker_offers_allowed")) +
+            ' offers as configured in joinmarket.cfg')
+        remove_makers_with_too_many_offers(self.taker.db,
+            jm_single().config.getint("POLICY", "max_maker_offers_allowed"))
         while True:
             orders, total_cj_fee = choose_orders(
                     self.taker.db, cj_amount, makercount, weighted_order_choose,
@@ -237,6 +243,11 @@ def create_tx(self):
             fee_for_tx = int(fee_for_tx / self.tx['makercount'])
             total_value = sum([addrval['value'] for addrval in utxos.values()])
             while True:
+                log.info('Removing makers with more than ' +
+                    str(jm_single().config.getint("POLICY", "max_maker_offers_allowed")) +
+                    ' offers as configured in joinmarket.cfg')
+                remove_makers_with_too_many_offers(self.taker.db,
+                    jm_single().config.getint("POLICY", "max_maker_offers_allowed"))
                 orders, cj_amount, total_cj_fee = choose_sweep_orders(
                     self.taker.db, total_value, fee_for_tx,
                         self.tx['makercount'], weighted_order_choose,