Merge #6664: fix: MN port validation on mainnet is broken after 6627

2e8c7ef refactor: simplify (non-)mainnet port check condition (UdjinM6)
78ebaeb test: use mainnet setup in evo_netinfo_tests (Kittywhiskers Van Gogh)
20afc99 fix: MN port validation is broken after 6627 (UdjinM6)

Pull request description:

  ## Issue being fixed or feature implemented
  #6627 broke MN port validation on mainnet - `develop` fails with `bad-protx-netinfo-port` for a completely valid protx

  ## What was done?
  Implement it the way it was before https://github.com/dashpay/dash/pull/6627/files#diff-0998f8dfc4c1089e90cbaafe9607b361035b904cd103df31e3c2339a3cbf790dL1189-L1195

  ## How Has This Been Tested?
  Sync on mainnet

  ## Breaking Changes
  n/a

  ## Checklist:
  - [ ] I have performed a self-review of my own code
  - [ ] I have commented my code, particularly in hard-to-understand areas
  - [ ] I have added or updated relevant unit/integration/functional/e2e tests
  - [ ] I have made corresponding changes to the documentation
  - [ ] I have assigned this pull request to a milestone _(for repository code-owners and collaborators only)_

ACKs for top commit:
  kwvg:
    utACK 2e8c7ef
  knst:
    utACK 2e8c7ef

Tree-SHA512: 1601d5013479c05e06d2f78f5d0ab133f69d37a4580eb7f69fb2c5c0797623bca4f9e55a0048245abbfeb0fcb44de8a43dae6b8b8e58f5f8501d36277bbdc26d

Author: PastaPastaPasta

src/evo/netinfo.cpp

@@ -36,12 +36,9 @@ NetInfoStatus MnNetInfo::ValidateService(const CService& service)
         return NetInfoStatus::BadInput;
     }
 
-    const auto default_port_main = MainParams().GetDefaultPort();
-    if (IsNodeOnMainnet() && service.GetPort() != default_port_main) {
-        // Must use mainnet port on mainnet
-        return NetInfoStatus::BadPort;
-    } else if (service.GetPort() == default_port_main) {
-        // Using mainnet port prohibited outside of mainnet
+    if (IsNodeOnMainnet() != (service.GetPort() == MainParams().GetDefaultPort())) {
+        // Must use mainnet port on mainnet.
+        // Must NOT use mainnet port on other networks.
         return NetInfoStatus::BadPort;
     }
 

src/test/evo_netinfo_tests.cpp

@@ -11,29 +11,31 @@
 
 #include <boost/test/unit_test.hpp>
 
+BOOST_FIXTURE_TEST_SUITE(evo_netinfo_tests, BasicTestingSetup)
+
 const std::vector<std::pair</*input=*/std::string, /*expected_ret=*/NetInfoStatus>> vals{
     // Address and port specified
-    {"1.1.1.1:8888", NetInfoStatus::Success},
+    {"1.1.1.1:9999", NetInfoStatus::Success},
     // Address specified, port should default to default P2P core
     {"1.1.1.1", NetInfoStatus::Success},
-    // Mainnet P2P port on non-mainnet
-    {"1.1.1.1:9999", NetInfoStatus::BadPort},
+    // Non-mainnet port on mainnet
+    {"1.1.1.1:9998", NetInfoStatus::BadPort},
+    // Internal addresses not allowed on mainnet
+    {"127.0.0.1:9999", NetInfoStatus::BadInput},
     // Valid IPv4 formatting but invalid IPv4 address
-    {"0.0.0.0:8888", NetInfoStatus::BadInput},
+    {"0.0.0.0:9999", NetInfoStatus::BadInput},
     // Port greater than uint16_t max
     {"1.1.1.1:99999", NetInfoStatus::BadInput},
     // Only IPv4 allowed
-    {"[2606:4700:4700::1111]:8888", NetInfoStatus::BadInput},
+    {"[2606:4700:4700::1111]:9999", NetInfoStatus::BadInput},
     // Domains are not allowed
-    {"example.com:8888", NetInfoStatus::BadInput},
+    {"example.com:9999", NetInfoStatus::BadInput},
     // Incorrect IPv4 address
-    {"1.1.1.256:8888", NetInfoStatus::BadInput},
+    {"1.1.1.256:9999", NetInfoStatus::BadInput},
     // Missing address
-    {":8888", NetInfoStatus::BadInput},
+    {":9999", NetInfoStatus::BadInput},
 };
 
-BOOST_FIXTURE_TEST_SUITE(evo_netinfo_tests, RegTestingSetup)
-
 void ValidateGetEntries(const CServiceList& entries, const size_t expected_size)
 {
     BOOST_CHECK_EQUAL(entries.size(), expected_size);