fix: port 0 is not a bad one

[UdjinM6]

Issue being fixed or feature implemented

An ephemeral port is allocated to a socket in the following circumstances:

          *  the port number in a socket address is specified as 0 when
             calling bind(2);

source

#6535 follow-up

What was done?

How Has This Been Tested?

Breaking Changes

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)

[coderabbitai]

dropped for merge commit simplifification

[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (1)

src/test/netbase_tests.cpp (1)

Line range hint 454-465: Consider making the bad ports count test more maintainable.

While the count verification is good practice, consider defining the expected count as a named constant. This would make the test more maintainable when the bad port list changes in the future.

+    static constexpr size_t EXPECTED_BAD_PORTS = 21;
     size_t total_bad_ports{0};
     for (uint16_t port = std::numeric_limits<uint16_t>::max(); port > 0; --port) {
         if (IsBadPort(port)) {
             ++total_bad_ports;
         }
     }
-    BOOST_CHECK_EQUAL(total_bad_ports - PRIVILEGED_PORTS_THRESHOLD, 21);
+    BOOST_CHECK_EQUAL(total_bad_ports - PRIVILEGED_PORTS_THRESHOLD, EXPECTED_BAD_PORTS);

📜 Review details

Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 78f242b and 8c30f73.

📒 Files selected for processing (2)

• src/netbase.cpp (1 hunks)
• src/test/netbase_tests.cpp (1 hunks)

⏰ Context from checks skipped due to timeout of 90000ms (2)

• GitHub Check: Build Dependencies (linux64, x86_64-pc-linux-gnu)
• GitHub Check: Build Dependencies (arm-linux, arm-linux-gnueabihf)

🔇 Additional comments (2)

src/netbase.cpp (1)

712-712: LGTM! The change correctly allows port 0 for ephemeral port allocation.

The modification to exclude port 0 from bad ports is correct. In POSIX socket programming, binding to port 0 is a special case that tells the operating system to allocate an ephemeral port, which is a common and valid practice.

src/test/netbase_tests.cpp (1)

453-453: LGTM! Comprehensive test coverage for the port 0 change.

The test case properly verifies that port 0 is now allowed while maintaining checks for other port classifications.

[kwvg]

utACK 8c30f73

[PastaPastaPasta]

utACK 8c30f73; nit, could've been one commit