Merge bitcoin/bitcoin#24205: init, test: improve network reachability test coverage and safety

58a14795b8 test: passing -onlynet=onion with -onion=0/-noonion raises expected init error (Jon Atack)
7000f66d36 test: passing -onlynet=onion without -proxy/-onion raises expected init error (Jon Atack)
8332e6e4cf test: passing invalid -onion raises expected init error (Jon Atack)
d5edb08708 test: passing invalid -proxy raises expected init error (Jon Atack)
bd57dcbaf2 test: hoist proxy out of 2 network loops in feature_proxy.py (Jon Atack)
afdf2de282 test: add CJDNS to LimitedAndReachable_Network unit tests (Jon Atack)
2b7a8180a9 net, init: assert each network reachability is true by default (Jon Atack)

Pull request description:

  Adds missing network reachability test coverage and an assertion during init, noticed while reviewing #22834:

  - assert during init that each network reachability is  true by default
  - add CJDNS to the `LimitedAndReachable_Network` unit tests
  - hoist proxy out of two network loops in feature_proxy.py
  - test that passing invalid `-proxy` raises expected init error
  - test that passing invalid `-onion` raises expected init error
  - test that passing `-onlynet=onion` without `-proxy` and `-onion` raises expected init error
  - test that passing `-onlynet=onion` with `-onion=0` and with `-noonion` raises expected init error

ACKs for top commit:
  vasild:
    ACK 58a14795b8
  brunoerg:
    ACK 58a14795b8
  dongcarl:
    Code Review ACK 58a14795b8

Tree-SHA512: bdee6dd0c12bb63591ce7c9321fe77b509ab1265123054e774adc38a187746dddafe1627cbe89e990bcc78b45e194bfef8dc782710d5b217e2e2106ab0158827

src/init.cpp

@@ -1302,6 +1302,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         }
         for (int n = 0; n < NET_MAX; n++) {
             enum Network net = (enum Network)n;
+            assert(IsReachable(net));
             if (!nets.count(net))
                 SetReachable(net, false);
         }

src/test/net_tests.cpp

@@ -732,26 +732,31 @@ BOOST_AUTO_TEST_CASE(LimitedAndReachable_Network)
     BOOST_CHECK(IsReachable(NET_IPV6));
     BOOST_CHECK(IsReachable(NET_ONION));
     BOOST_CHECK(IsReachable(NET_I2P));
+    BOOST_CHECK(IsReachable(NET_CJDNS));
 
     SetReachable(NET_IPV4, false);
     SetReachable(NET_IPV6, false);
     SetReachable(NET_ONION, false);
     SetReachable(NET_I2P, false);
+    SetReachable(NET_CJDNS, false);
 
     BOOST_CHECK(!IsReachable(NET_IPV4));
     BOOST_CHECK(!IsReachable(NET_IPV6));
     BOOST_CHECK(!IsReachable(NET_ONION));
     BOOST_CHECK(!IsReachable(NET_I2P));
+    BOOST_CHECK(!IsReachable(NET_CJDNS));
 
     SetReachable(NET_IPV4, true);
     SetReachable(NET_IPV6, true);
     SetReachable(NET_ONION, true);
     SetReachable(NET_I2P, true);
+    SetReachable(NET_CJDNS, true);
 
     BOOST_CHECK(IsReachable(NET_IPV4));
     BOOST_CHECK(IsReachable(NET_IPV6));
     BOOST_CHECK(IsReachable(NET_ONION));
     BOOST_CHECK(IsReachable(NET_I2P));
+    BOOST_CHECK(IsReachable(NET_CJDNS));
 }
 
 BOOST_AUTO_TEST_CASE(LimitedAndReachable_NetworkCaseUnroutableAndInternal)

test/functional/feature_proxy.py

@@ -30,6 +30,11 @@ addnode connect to generic DNS name
 addnode connect to a CJDNS address
 
 - Test getnetworkinfo for each node
+
+- Test passing invalid -proxy
+- Test passing invalid -onion
+- Test passing -onlynet=onion without -proxy or -onion
+- Test passing -onlynet=onion with -onion=0 and with -noonion
 """
 
 import socket
@@ -263,12 +268,13 @@ class ProxyTest(BitcoinTestFramework):
 
         n2 = networks_dict(self.nodes[2].getnetworkinfo())
         assert_equal(NETWORKS, n2.keys())
+        proxy = f'{self.conf2.addr[0]}:{self.conf2.addr[1]}'
         for net in NETWORKS:
             if net == NET_I2P:
                 expected_proxy = ''
                 expected_randomize = False
             else:
-                expected_proxy = f'{self.conf2.addr[0]}:{self.conf2.addr[1]}'
+                expected_proxy = proxy
                 expected_randomize = True
             assert_equal(n2[net]['proxy'], expected_proxy)
             assert_equal(n2[net]['proxy_randomize_credentials'], expected_randomize)
@@ -279,11 +285,9 @@ class ProxyTest(BitcoinTestFramework):
         if self.have_ipv6:
             n3 = networks_dict(self.nodes[3].getnetworkinfo())
             assert_equal(NETWORKS, n3.keys())
+            proxy = f'[{self.conf3.addr[0]}]:{self.conf3.addr[1]}'
             for net in NETWORKS:
-                if net == NET_I2P or net == NET_ONION:
-                    expected_proxy = ''
-                else:
-                    expected_proxy = f'[{self.conf3.addr[0]}]:{self.conf3.addr[1]}'
+                expected_proxy = '' if net == NET_I2P or net == NET_ONION else proxy
                 assert_equal(n3[net]['proxy'], expected_proxy)
                 assert_equal(n3[net]['proxy_randomize_credentials'], False)
             assert_equal(n3['onion']['reachable'], False)
@@ -305,6 +309,32 @@ class ProxyTest(BitcoinTestFramework):
         assert_equal(n4['i2p']['reachable'], False)
         assert_equal(n4['cjdns']['reachable'], True)
 
+        self.stop_node(1)
+
+        self.log.info("Test passing invalid -proxy raises expected init error")
+        self.nodes[1].extra_args = ["-proxy=abc:def"]
+        msg = "Error: Invalid -proxy address or hostname: 'abc:def'"
+        self.nodes[1].assert_start_raises_init_error(expected_msg=msg)
+
+        self.log.info("Test passing invalid -onion raises expected init error")
+        self.nodes[1].extra_args = ["-onion=xyz:abc"]
+        msg = "Error: Invalid -onion address or hostname: 'xyz:abc'"
+        self.nodes[1].assert_start_raises_init_error(expected_msg=msg)
+
+        msg = (
+            "Error: Outbound connections restricted to Tor (-onlynet=onion) but "
+            "the proxy for reaching the Tor network is not provided (no -proxy= "
+            "and no -onion= given) or it is explicitly forbidden (-onion=0)"
+        )
+        self.log.info("Test passing -onlynet=onion without -proxy or -onion raises expected init error")
+        self.nodes[1].extra_args = ["-onlynet=onion"]
+        self.nodes[1].assert_start_raises_init_error(expected_msg=msg)
+
+        self.log.info("Test passing -onlynet=onion with -onion=0/-noonion raises expected init error")
+        for arg in ["-onion=0", "-noonion"]:
+            self.nodes[1].extra_args = ["-onlynet=onion", arg]
+            self.nodes[1].assert_start_raises_init_error(expected_msg=msg)
+
 
 if __name__ == '__main__':
     ProxyTest().main()