moved rhapsody-in-green off v3

common/optional/x86-64-v3/patches/gnutls/README.md

@@ -0,0 +1,160 @@
+# GnuTLS UDP server readiness
+
+Under load, the test client can start before `gnutls-serv` binds its UDP
+socket, and the first handshake fails with `Connection refused`.
+`serv-udp.sh` currently waits a fixed four seconds; elapsed time does not
+establish server readiness. `udp-server-readiness.patch` replaces that wait
+with polling for the local IPv4 UDP endpoint.
+
+## Scope and waiting behavior
+
+The patch changes the existing `wait_udp_server()` and adds a new
+`check_if_udp_port_bound()` beside it in `tests/scripts/common.sh`.
+`serv-udp.sh` is its only caller in 3.8.13. The TCP helpers `wait_server()`
+and `wait_for_port()`, including their existing sleeps, are unchanged.
+Both original DTLS handshake checks remain unchanged.
+
+Each iteration checks process liveness and the socket **before sleeping**.
+A ready socket returns immediately. An unsuccessful check sleeps two
+seconds only if another attempt remains: at most 90 attempts, consistent
+with the existing `wait_server()` budget implemented by `wait_for_port()`,
+with no sleep after the final check. Server exit fails early; exhausting the
+budget fails and terminates the server. No handshake is retried, and no
+protocol timeout is changed. Once bound, the kernel can queue datagrams
+while the server is scheduled; the probe itself sends no packets.
+
+The existing `have_port_finder()` prefers `ss`, then `netstat`. If neither
+exists, it prints `neither ss nor netstat found` and exits **77 (skip)**.
+In the normal test flow, port selection calls it before launching a server.
+The probe runs in a subshell so that, even if this skip occurs after launch,
+the waiting helper can terminate and reap the server before exiting 77.
+
+## Why an IPv4 socket is expected
+
+This is specific to the server used by this test, not a general rule that
+IPv6 sockets cannot serve IPv4 clients. The client explicitly uses
+`127.0.0.1`. The server's `--udp` path calls `udp_server()`, which calls
+`listen_socket(..., SOCK_DGRAM)`. That function iterates the wildcard
+addresses returned by `getaddrinfo(NULL, ..., AI_PASSIVE)`:
+
+| Server build / Linux setting | Binding behavior |
+| --- | --- |
+| IPv6 enabled, `net.ipv6.bindv6only=0` | Requests `IPV6_V6ONLY=1` on the IPv6 socket, binds `[::]:PORT`, and separately binds `0.0.0.0:PORT`. It overrides the system's dual-stack default. |
+| IPv6 enabled, `net.ipv6.bindv6only=1` | The same explicit socket option and separate IPv4/IPv6 binds. |
+| `HAVE_IPV6` undefined | Skips every address family except `AF_INET`; only the IPv4 wildcard is attempted. |
+
+`udp_server()` uses `wait_for_connection()`, which puts **every listener**
+from that list into `select()` and returns a readable socket for `recvfrom()`;
+it does not permanently choose one socket based on `getaddrinfo()` order.
+
+The first two cases were traced with the actual GnuTLS 3.8.13 binary in
+separate Linux network namespaces: `setsockopt(IPV6_V6ONLY, [1])` and both
+UDP binds returned success under each setting. The no-IPv6 case was checked
+in source, not by building a second binary. The same bind implementation
+was checked directly on GitLab master.
+
+Thus, successful normal startup for this invocation provides an explicit
+IPv4 socket; a lone IPv6 wildcard is not the expected success path.
+There is one portability caveat: upstream discards the return value of
+`setsockopt(IPV6_V6ONLY)`. On a platform where that call fails and the server
+ends up with only a dual-stack socket, this helper would time out despite
+IPv4 reachability. Such a platform needs additional handling before this
+patch can claim support. Blindly accepting every IPv6 wildcard would also
+accept IPv6-only sockets before the separate IPv4 bind finishes.
+
+Source: [`src/serv.c`, `listen_socket()`](https://gitlab.com/gnutls/gnutls/-/blob/master/src/serv.c#L937),
+[`src/udp-serv.c`](https://gitlab.com/gnutls/gnutls/-/blob/master/src/udp-serv.c),
+and [`tests/serv-udp.sh`](https://gitlab.com/gnutls/gnutls/-/blob/master/tests/serv-udp.sh).
+
+## Port matching and ownership limit
+
+Only `-an` is passed to the socket-listing tool: BSD `netstat -u` selects
+Unix-domain sockets, whereas Linux `netstat -u` selects UDP. The parser
+handles the extra state column in `ss`, Linux colon-separated endpoints,
+and BSD dot-separated endpoints, including `*.PORT`. It matches the full
+local port and rejects TCP, IPv6 entries, peer ports, and longer numbers.
+
+A live PID plus a bound port does **not** prove that PID owns the socket.
+Existing `GETPORT` selection checks for an unused port and uses a test
+port-lock directory; `launch_bare_server()` also calls
+`wait_for_free_port()` before starting the process. These are advisory:
+the launcher does not enforce the latter's result, and another process
+can bind between the check and launch. The patch does not close that race
+or add nonportable PID parsing. An unrelated process can satisfy the
+socket check; the real handshakes remain the functional check and may
+fail (or reach the wrong server). This is a startup-order fix, not a
+socket-ownership guarantee.
+
+## Reproduction and focused checks
+
+Apply the patch to an unpacked source tree, then run the companion checks
+with Python's standard library and a shell:
+
+```sh
+patch --fuzz=0 -d /path/to/gnutls -p1 < udp-server-readiness.patch
+SHELL=/bin/sh python3 verify-readiness.py /path/to/gnutls/tests/scripts/common.sh -v
+```
+
+Set `NETSTAT=/path/to/netstat` to exercise one outside `PATH`. The checks
+cover Linux/BSD output samples, false matches, immediate readiness,
+missing tools, process exit, timeout cleanup, and real IPv4 UDP sockets
+whose bind is delayed six seconds. The missing-tools fixture is skipped
+if an absolute fallback `ss` path cannot be hidden with `PATH`. Native
+BSD execution remains untested.
+
+To reproduce with GnuTLS itself, run `tests/serv-udp.sh` with `SERV` pointing
+to a wrapper that sleeps six seconds, then `exec`s `gnutls-serv` with all
+arguments. Set `CLI` to the matching `gnutls-cli`, `srcdir` to the source
+`tests` directory, and `abs_top_builddir` to a writable build directory.
+With GnuTLS 3.8.13, the original helper failed the first handshake with
+`Connection refused`; the patched helper passed both with the same binaries.
+
+## GnuTLS submission
+
+Development and merge requests are on [GitLab](https://gitlab.com/gnutls/gnutls).
+[`CONTRIBUTING.md` on master](https://gitlab.com/gnutls/gnutls/-/blob/master/CONTRIBUTING.md)
+was read directly for this review. It requires the contributor's DCO
+`Signed-off-by`, successful and failure test coverage, consistent coding
+style, and adequate documentation; GitLab CI runs for merge requests.
+Its commenting guidance asks for comments explaining non-obvious behavior
+or protocol expectations. It does not prescribe an additional special
+test-suite comment. The patch now explains its IPv4 binding assumption
+next to the probe.
+
+The submission will contain the shell patch, without the Python verifier
+or a new Python test dependency. The existing `serv-udp.sh` supplies the
+functional success check. Running it through the six-second startup
+wrapper supplies a reproducible regression case: it fails before the fix
+and passes after it. The local verifier was used to validate socket-output
+parsing and the helper's success, process-exit, skip-cleanup, and timeout
+branches. Those branch checks are local evidence, not new automated
+coverage in the upstream suite; the MR must state that distinction.
+
+No dedicated unit-test harness for these shell helpers was found in the
+3.8.13 tests inspected. That does not establish that Python cannot be used
+upstream; keeping this submission dependency-free is a scope choice. Use
+the existing test and before/after reproduction as the submission's
+coverage argument, retaining the platform limitations above. Apply the
+patch in an upstream checkout and include those results with the
+contributor's own sign-off. No MR or sign-off has been created.
+
+## Local NixOS integration and build results
+
+`overlays/default.nix` imports the `overlays/patches` overlay, which loads
+`gnutls/default.nix` to apply the patch and keep `serv-udp.sh` enabled.
+The patch itself has no Nix dependencies and applies to 3.8.13 and GitLab
+master without fuzz.
+
+The final patch was rebuilt with:
+
+```sh
+nix build --no-link -L .#nixosConfigurations.jeeves.pkgs.gnutls
+```
+
+That x86-64-v3 build passed: 927 tests, 796 passes, 131 existing skips,
+zero failures/errors, and `PASS: serv-udp.sh`. The patch bytes in the built
+derivation were compared with the repository artifact; both have SHA-256
+`59013d47fd446f2dd065012a2259ccc1898fedc8a053a630e13efa0076368760`.
+All seven local checks passed, including skip cleanup and exactly 90
+probes with 89 sleeps on timeout. The six-second before/after reproduction
+was also repeated successfully with the final helper.

common/optional/x86-64-v3/patches/gnutls/default.nix

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+{ gnutls }:
+gnutls.overrideAttrs (old: {
+  # Keep the UDP handshake test enabled on loaded builders by waiting for
+  # the server to bind its socket. Kept as a standalone patch for upstream.
+  patches = (old.patches or [ ]) ++ [ ./udp-server-readiness.patch ];
+})

common/optional/x86-64-v3/patches/gnutls/udp-server-readiness.patch

@@ -0,0 +1,70 @@
+Subject: [PATCH] tests: wait for the UDP server socket before connecting
+
+A fixed four-second sleep does not guarantee that gnutls-serv has bound
+its UDP socket on a busy builder. Poll the local IPv4 UDP endpoint using
+the existing ss/netstat discovery, with the same retry budget as the TCP
+helper. Fail early if the server exits, and retain the original handshake
+checks in serv-udp.sh.
+
+Use flags common to ss and BSD/Linux netstat. Match the local endpoint
+and complete port number, excluding TCP, IPv6-only and peer endpoints.
+
+--- a/tests/scripts/common.sh
++++ b/tests/scripts/common.sh
+@@ -185,10 +185,55 @@
+ 	fi
+ }
+ 
++check_if_udp_port_bound() {
++	local PORT=$1
++	have_port_finder
++	# Use only -an, which is shared by ss and BSD/Linux netstat. UDP has
++	# no LISTEN state. Match the local IPv4 endpoint, not a peer port or
++	# a longer port number. serv-udp.sh connects to 127.0.0.1;
++	# listen_socket() in serv.c binds IPv4 separately and requests
++	# IPV6_V6ONLY=1 for its IPv6 socket.
++	$PFCMD -an | awk -v port="$PORT" '
++		$1 == "udp" || $1 == "udp4" {
++			# ss includes a state column; netstat does not.
++			address = ($2 == "UNCONN" || $2 == "ESTAB") ? $5 : $4
++			if (address ~ ("^[0-9.]+[.:]" port "$") ||
++			    address == "*." port)
++				found = 1
++		}
++		END { exit !found }
++	'
++}
++
+ wait_udp_server() {
+ 	local PID=$1
++	local ret
+ 	trap "test -n \"${PID}\" && kill ${PID};exit 1" 1 15 2
+-	sleep 4
++	local i=0
++	# Use the same retry budget as wait_for_port(), but also stop if the
++	# server exits before binding its socket.
++	while test $i -lt 90; do
++		if ! kill -0 "$PID" 2>/dev/null; then
++			fail "" "UDP server $PID exited before binding port $PORT"
++		fi
++		# Contain have_port_finder's exit so a skip also stops the server.
++		if (check_if_udp_port_bound "$PORT"); then
++			return 0
++		else
++			ret=$?
++			if test "$ret" = 77; then
++				kill "$PID" 2>/dev/null || :
++				wait "$PID" 2>/dev/null || :
++				exit 77
++			fi
++		fi
++		i=$((i + 1))
++		if test $i -lt 90; then
++			echo "try $i: waiting for UDP port $PORT"
++			sleep 2
++		fi
++	done
++	fail "$PID" "UDP server $PORT did not come up"
+ }
+ 
+ create_testdir() {

common/optional/x86-64-v3/patches/gnutls/verify-readiness.py

@@ -0,0 +1,180 @@
+#!/usr/bin/env python3
+"""Exercise patched common.sh without building GnuTLS (Python standard library only).
+
+Usage: python3 verify-readiness.py /path/to/patched/tests/scripts/common.sh
+Set SHELL to test another shell, and NETSTAT to test a netstat outside PATH.
+"""
+
+# Use unittest so this upstream companion tool needs no pytest installation.
+# ruff: noqa: PT009
+
+import os
+import shutil
+import socket
+import subprocess
+import sys
+import tempfile
+import time
+import unittest
+from pathlib import Path
+
+COMMON = str(Path(sys.argv.pop(1)).resolve())
+SHELL = os.environ.get("SHELL", "/bin/sh")
+
+
+class ReadinessTests(unittest.TestCase):
+    """Check endpoint parsing and the server startup lifecycle."""
+
+    def setUp(self) -> None:
+        """Create a socket-listing fixture for each check."""
+        self.tmp = tempfile.TemporaryDirectory()
+        self.addCleanup(self.tmp.cleanup)
+        self.root = Path(self.tmp.name)
+        self.fixture = self.root / "sockets"
+        self.fixture.write_text("")
+        self.finder = self.root / "port-finder"
+        self.finder.write_text('#!/bin/sh\ncat "$SOCKET_FIXTURE"\n')
+        self.finder.chmod(0o755)
+
+    def run_shell(self, body: str, **env: str) -> subprocess.CompletedProcess[str]:
+        """Source the actual helper and run a shell scenario."""
+        return subprocess.run(
+            [SHELL, "-c", '. "$COMMON"\n' + body],
+            env={
+                **os.environ,
+                "COMMON": COMMON,
+                "SOCKET_FIXTURE": str(self.fixture),
+                "PFCMD": str(self.finder),
+                "PORT": "12345",
+                **env,
+            },
+            capture_output=True,
+            text=True,
+            timeout=20,
+            check=False,
+        )
+
+    def test_socket_formats_and_false_matches(self) -> None:
+        """Accept IPv4 UDP local endpoints and reject unrelated sockets."""
+        cases = [
+            ("udp UNCONN 0 0 0.0.0.0:12345 0.0.0.0:*", True),
+            ("udp UNCONN 0 0 127.0.0.1:12345 0.0.0.0:*", True),
+            ("udp 0 0 0.0.0.0:12345 0.0.0.0:*", True),
+            ("udp4 0 0 *.12345 *.*", True),
+            ("udp 0 0 127.0.0.1.12345 *.*", True),
+            ("udp 0 0 *.12345 *.*", True),
+            ("udp UNCONN 0 0 0.0.0.0:123456 0.0.0.0:*", False),
+            ("udp 0 0 0.0.0.0:123456 0.0.0.0:*", False),
+            ("udp ESTAB 0 0 127.0.0.1:54321 127.0.0.1:12345", False),
+            ("udp 0 0 127.0.0.1:54321 127.0.0.1:12345", False),
+            ("tcp LISTEN 0 128 0.0.0.0:12345 0.0.0.0:*", False),
+            ("tcp 0 0 0.0.0.0:12345 0.0.0.0:* LISTEN", False),
+            ("udp UNCONN 0 0 [::]:12345 [::]:*", False),
+            ("udp UNCONN 0 0 *:12345 *:*", False),
+            ("udp6 0 0 :::12345 :::*", False),
+            ("udp6 0 0 *.12345 *.*", False),
+            ("", False),
+        ]
+        for row, ready in cases:
+            with self.subTest(row=row):
+                self.fixture.write_text(row + "\n")
+                result = self.run_shell('check_if_udp_port_bound "$PORT"')
+                self.assertEqual(result.returncode, 0 if ready else 1, result.stderr)
+
+    def test_exited_server_fails_immediately(self) -> None:
+        """Fail without sleeping when the server has already exited."""
+        result = self.run_shell(
+            'true &\npid=$!\nwait "$pid"\nsleep() { echo "unexpected sleep" >&2; }\nwait_udp_server "$pid"'
+        )
+        self.assertEqual(result.returncode, 1)
+        self.assertIn("exited before binding", result.stderr)
+        self.assertNotIn("unexpected sleep", result.stderr)
+
+    def test_ready_socket_does_not_sleep(self) -> None:
+        """Check readiness before the first sleep."""
+        self.fixture.write_text("udp UNCONN 0 0 0.0.0.0:12345 0.0.0.0:*\n")
+        result = self.run_shell('sleep() { echo "unexpected sleep" >&2; }\nwait_udp_server "$$"')
+        self.assertEqual(result.returncode, 0, result.stderr)
+        self.assertNotIn("unexpected sleep", result.stderr)
+
+    def test_missing_port_finders_skip(self) -> None:
+        """Skip and stop the live server when no finder is available."""
+        # have_port_finder also tries these paths independently of PATH.
+        if any(os.access(f"{directory}/ss", os.X_OK) for directory in ("/sbin", "/usr/sbin", "/usr/local/sbin")):
+            self.skipTest("an absolute ss path cannot be hidden by this PATH-only fixture")
+        with subprocess.Popen(["sleep", "60"]) as server:
+            try:
+                result = self.run_shell(
+                    'unset PFCMD\nPATH=/nonexistent\nwait_udp_server "$SERVER_PID"',
+                    SERVER_PID=str(server.pid),
+                )
+                self.assertEqual(result.returncode, 77)
+                self.assertIn("neither ss nor netstat found", result.stderr)
+                server.wait(timeout=3)
+                self.assertLess(server.returncode, 0)
+            finally:
+                if server.poll() is None:
+                    server.kill()
+
+    def test_timeout_is_bounded_and_cleans_up(self) -> None:
+        """Stop polling after the retry budget and terminate the server."""
+        # Only accelerate the polling delay; keep a real live server process.
+        self.finder.write_text('#!/bin/sh\necho probe >&2\ncat "$SOCKET_FIXTURE"\n')
+        with subprocess.Popen(["sleep", "60"]) as server:
+            try:
+                result = self.run_shell(
+                    'sleep() { echo polling-sleep; }\nwait_udp_server "$SERVER_PID"',
+                    SERVER_PID=str(server.pid),
+                )
+                self.assertEqual(result.returncode, 1)
+                self.assertIn("did not come up", result.stderr)
+                self.assertEqual(result.stderr.count("probe\n"), 90)
+                self.assertEqual(result.stdout.count("polling-sleep"), 89)
+                server.wait(timeout=3)
+                self.assertLess(server.returncode, 0)
+            finally:
+                if server.poll() is None:
+                    server.kill()
+
+    def test_server_exits_while_waiting(self) -> None:
+        """Detect a startup failure that happens after polling begins."""
+        result = self.run_shell('sleep 1 &\npid=$!\nwait_udp_server "$pid"')
+        self.assertEqual(result.returncode, 1)
+        self.assertIn("exited before binding", result.stderr)
+        self.assertIn("waiting for UDP port", result.stdout)
+
+    def test_real_socket_delayed_beyond_four_seconds(self) -> None:
+        """Wait for a real delayed bind with each installed port finder."""
+        finders = [shutil.which("ss"), os.environ.get("NETSTAT") or shutil.which("netstat")]
+        finders = [finder for finder in finders if finder]
+        if not finders:
+            self.skipTest("neither ss nor netstat available")
+        for finder in finders:
+            with self.subTest(finder=finder):
+                with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as sock:
+                    sock.bind(("127.0.0.1", 0))
+                    port = sock.getsockname()[1]
+                code = (
+                    "import socket,time,sys; time.sleep(6); "
+                    "s=socket.socket(socket.AF_INET,socket.SOCK_DGRAM); "
+                    "s.bind(('127.0.0.1',int(sys.argv[1]))); time.sleep(30)"
+                )
+                with subprocess.Popen([sys.executable, "-c", code, str(port)]) as server:
+                    try:
+                        started = time.monotonic()
+                        result = self.run_shell(
+                            'wait_udp_server "$SERVER_PID"',
+                            SERVER_PID=str(server.pid),
+                            PORT=str(port),
+                            PFCMD=finder,
+                        )
+                        self.assertEqual(result.returncode, 0, result.stderr)
+                        self.assertGreaterEqual(time.monotonic() - started, 6)
+                        self.assertIsNone(server.poll())
+                    finally:
+                        server.terminate()
+                        server.wait(timeout=3)
+
+
+if __name__ == "__main__":
+    unittest.main()