Merge #20852: net: allow CSubNet of non-IP networks

39b43298d9 test: add test for banning of non-IP addresses (Vasil Dimov)
94d335da7f net: allow CSubNet of non-IP networks (Vasil Dimov)

Pull request description:

  Allow creation of valid `CSubNet` objects of non-IP networks and only
  match the single address they were created from (like /32 for IPv4 or
  /128 for IPv6).

  This fixes a deficiency in `CConnman::DisconnectNode(const CNetAddr& addr)`
  and in `BanMan` which assume that creating a subnet from any address
  using the `CSubNet(CNetAddr)` constructor would later match that address
  only. Before this change a non-IP subnet would be invalid and would not
  match any address.

ACKs for top commit:
  jonatack:
    Code review re-ACK 39b43298d9 per `git diff 5e95ce6 39b4329`; only change since last review is improvements to the functional test; verified the test fails on master @ 616eace0 where expected (`assert(self.is_banned(node, tor_addr))` fails and unban unfails)
  laanwj:
    code review ACK 39b43298d9

Tree-SHA512: 3239b26d0f2fa2d1388b4fdbc1d05ce4ac1980be699c6ec46049409baefcb2006b1e72b889871e2210e897f6725c48e873f68457eea7e6e4958ab4f959d20297

test/functional/rpc_setban.py

@@ -15,6 +15,9 @@ class SetBanTests(BitcoinTestFramework):
         self.setup_clean_chain = True
         self.extra_args = [[],[]]
 
+    def is_banned(self, node, addr):
+        return any(e['address'] == addr for e in node.listbanned())
+
     def run_test(self):
         # Node 0 connects to Node 1, check that the noban permission is not granted
         self.connect_nodes(0, 1)
@@ -42,5 +45,18 @@ class SetBanTests(BitcoinTestFramework):
         peerinfo = self.nodes[1].getpeerinfo()[0]
         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))
+        node.setban(tor_addr, "add")
+        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))
+
 if __name__ == '__main__':
     SetBanTests().main()