Merge bitcoin/bitcoin#20966: banman: save the banlist in a JSON format on disk

bb719a08db173a753984a04534de6f148b87b17a style: remove () from assert in rpc_setban.py (Vasil Dimov)
24b10ebda301548b8ff4b0c73fefc367ad5dc22b doc: fix grammar in doc/files.md (Vasil Dimov)
dd4e957dcdfc971a4a971995ff2db9fb787d23c3 test: ensure banlist can be read from disk after restart (Vasil Dimov)
d197977ae2076903ed12ab7616a7f93e88be02e1 banman: save the banlist in a JSON format on disk (Vasil Dimov)

Pull request description:

  Save the banlist in `banlist.json` instead of `banlist.dat`.

  This makes it possible to store Tor v3 entries in the banlist on disk
  (and any other addresses that cannot be serialized in addrv1 format).

  Only read `banlist.dat` if it exists and `banlist.json` does not exist (first start after an upgrade).

  Supersedes https://github.com/bitcoin/bitcoin/pull/20904
  Resolves https://github.com/bitcoin/bitcoin/issues/19748

ACKs for top commit:
  jonatack:
    Code review re-ACK bb719a08db173a753984a04534de6f148b87b17a per `git range-diff 6a67366 4b52c72 bb719a0`
  achow101:
    Code Review ACK bb719a08db173a753984a04534de6f148b87b17a

Tree-SHA512: fc135c3a1fe20bcf5d008ce6bea251b4135e56c78bf8f750b4bd8144c095b81ffe165133cdc7e4715875eec7e7c4e13ad9f5d2450b21102af063d7c8abf716b6

1 files changed, 22 insertions, 9 deletions

diff --git a/test/functional/rpc_setban.py b/test/functional/rpc_setban.py
index fd5f8aa098..36873f964b 100755
--- a/test/functional/rpc_setban.py
+++ b/test/functional/rpc_setban.py
@@ -22,7 +22,7 @@ class SetBanTests(BitcoinTestFramework):
         # Node 0 connects to Node 1, check that the noban permission is not granted
         self.connect_nodes(0, 1)
         peerinfo = self.nodes[1].getpeerinfo()[0]
-        assert(not 'noban' in peerinfo['permissions'])
+        assert not "noban" in peerinfo["permissions"]
 
         # Node 0 get banned by Node 1
         self.nodes[1].setban("127.0.0.1", "add")
@@ -36,27 +36,40 @@ class SetBanTests(BitcoinTestFramework):
         self.restart_node(1, ['-whitelist=127.0.0.1'])
         self.connect_nodes(0, 1)
         peerinfo = self.nodes[1].getpeerinfo()[0]
-        assert('noban' in peerinfo['permissions'])
+        assert "noban" in peerinfo["permissions"]
 
         # If we remove the ban, Node 0 should be able to reconnect even without noban permission
         self.nodes[1].setban("127.0.0.1", "remove")
         self.restart_node(1, [])
         self.connect_nodes(0, 1)
         peerinfo = self.nodes[1].getpeerinfo()[0]
-        assert(not 'noban' in peerinfo['permissions'])
+        assert not "noban" in peerinfo["permissions"]
 
         self.log.info("Test that a non-IP address can be banned/unbanned")
         node = self.nodes[1]
         tor_addr = "pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion"
         ip_addr = "1.2.3.4"
-        assert(not self.is_banned(node, tor_addr))
-        assert(not self.is_banned(node, ip_addr))
+        assert not self.is_banned(node, tor_addr)
+        assert not self.is_banned(node, ip_addr)
+
         node.setban(tor_addr, "add")
-        assert(self.is_banned(node, tor_addr))
-        assert(not self.is_banned(node, ip_addr))
+        assert self.is_banned(node, tor_addr)
+        assert not self.is_banned(node, ip_addr)
+
+        self.log.info("Test the ban list is preserved through restart")
+
+        self.restart_node(1)
+        assert self.is_banned(node, tor_addr)
+        assert not self.is_banned(node, ip_addr)
+
         node.setban(tor_addr, "remove")
-        assert(not self.is_banned(self.nodes[1], tor_addr))
-        assert(not self.is_banned(node, ip_addr))
+        assert not self.is_banned(self.nodes[1], tor_addr)
+        assert not self.is_banned(node, ip_addr)
+
+        self.restart_node(1)
+        assert not self.is_banned(node, tor_addr)
+        assert not self.is_banned(node, ip_addr)
+
 
 if __name__ == '__main__':
     SetBanTests().main()