From b9ae8e279038c65e4a81867e518bcb35719f30b6 Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Wed, 15 Jan 2025 22:32:22 +0800
Subject: [PATCH 01/19] Fix address and flags for send_fds/recv_fds

---
 Lib/socket.py           |  5 ++-
 Lib/test/test_socket.py | 84 ++++++++++++++++++++++++++++++++++++++---
 2 files changed, 81 insertions(+), 8 deletions(-)

diff --git a/Lib/socket.py b/Lib/socket.py
index be37c24d6174a2..4b8aa575b74594 100644
--- a/Lib/socket.py
+++ b/Lib/socket.py
@@ -563,7 +563,8 @@ def send_fds(sock, buffers, fds, flags=0, address=None):
         import array
 
         return sock.sendmsg(buffers, [(_socket.SOL_SOCKET,
-            _socket.SCM_RIGHTS, array.array("i", fds))])
+            _socket.SCM_RIGHTS, array.array("i", fds))],
+            flags, address)
     __all__.append("send_fds")
 
 if hasattr(_socket.socket, "recvmsg"):
@@ -579,7 +580,7 @@ def recv_fds(sock, bufsize, maxfds, flags=0):
         # Array of ints
         fds = array.array("i")
         msg, ancdata, flags, addr = sock.recvmsg(bufsize,
-            _socket.CMSG_LEN(maxfds * fds.itemsize))
+            _socket.CMSG_LEN(maxfds * fds.itemsize), flags)
         for cmsg_level, cmsg_type, cmsg_data in ancdata:
             if (cmsg_level == _socket.SOL_SOCKET and cmsg_type == _socket.SCM_RIGHTS):
                 fds.frombytes(cmsg_data[:
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index faf326d9164e1b..ce65f90c5f4bb1 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7037,6 +7037,12 @@ def test_dual_stack_client_v6(self):
 @requireAttrs(socket, "recv_fds")
 @requireAttrs(socket, "AF_UNIX")
 class SendRecvFdsTests(unittest.TestCase):
+    def _test_pipe(self, rfd, wfd, msg):
+        assert len(msg) < 512
+        os.write(wfd, msg)
+        data = os.read(rfd, 512)
+        self.assertEqual(data, msg)
+
     def testSendAndRecvFds(self):
         def close_pipes(pipes):
             for fd1, fd2 in pipes:
@@ -7066,13 +7072,79 @@ def close_fds(fds):
         # don't test addr
 
         # test that file descriptors are connected
-        for index, fds in enumerate(pipes):
-            rfd, wfd = fds
-            os.write(wfd, str(index).encode())
+        for index, ((_, wfd), rfd) in enumerate(zip(pipes, fds2)):
+            self._test_pipe(rfd, wfd, str(index).encode())
+
+    def test_send_recv_fds_with_addrs(self):
+        sock1 = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+        sock2 = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+        rfd, wfd = os.pipe()
+        self.addCleanup(os.close, rfd)
+        self.addCleanup(os.close, wfd)
+
+        with tempfile.TemporaryDirectory() as tmpdir, sock1, sock2:
+            sock1_addr = os.path.join(tmpdir, "sock1")
+            sock2_addr = os.path.join(tmpdir, "sock2")
+            sock1.bind(sock1_addr)
+            sock2.bind(sock2_addr)
+            sock2.setblocking(False)
+
+            socket.send_fds(sock1, [MSG], [rfd], address=sock2_addr)
+            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), 1)
+            new_rfd = fds[0]
+            self.addCleanup(os.close, new_rfd)
+
+        self.assertEqual(msg, MSG)
+        self.assertEqual(len(fds), 1)
+        self.assertEqual(addr, sock1_addr)
+
+        self._test_pipe(new_rfd, wfd, MSG)
+
+    @requireAttrs(socket, "MSG_PEEK")
+    def test_recv_fds_peek(self):
+        rfd, wfd = os.pipe()
+        self.addCleanup(os.close, rfd)
+        self.addCleanup(os.close, wfd)
 
-        for index, rfd in enumerate(fds2):
-            data = os.read(rfd, 100)
-            self.assertEqual(data,  str(index).encode())
+        sock1, sock2 = socket.socketpair(socket.AF_UNIX, socket.SOCK_DGRAM)
+        with sock1, sock2:
+            socket.send_fds(sock1, [MSG], [rfd])
+            sock2.setblocking(False)
+
+            # peek message on sock2
+            peek_len = len(MSG) // 2
+            msg, fds, flags, addr = socket.recv_fds(sock2, peek_len, 1,
+                                                    socket.MSG_PEEK)
+            self.addCleanup(os.close, fds[0])
+            self.assertEqual(len(msg), peek_len)
+            self.assertEqual(msg, MSG[:peek_len])
+            self.assertEqual(flags & socket.MSG_TRUNC, socket.MSG_TRUNC)
+            self._test_pipe(fds[0], wfd, MSG)
+
+            # will raise BlockingIOError if MSG_PEEK didn't work
+            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), 1)
+            self.addCleanup(os.close, fds[0])
+            self.assertEqual(msg, MSG)
+            self._test_pipe(fds[0], wfd, MSG)
+
+    @requireAttrs(socket, "MSG_DONTWAIT")
+    def test_send_fds_dontwait(self):
+        rfd, wfd = os.pipe()
+        self.addCleanup(os.close, rfd)
+        self.addCleanup(os.close, wfd)
+
+        sock1, sock2 = socket.socketpair(socket.AF_UNIX, socket.SOCK_DGRAM)
+        with sock1, sock2:
+            sock1.setblocking(True)
+            with self.assertRaises(BlockingIOError):
+                for _ in range(64 * 1024):
+                    socket.send_fds(sock1, [MSG], [rfd], socket.MSG_DONTWAIT)
+
+            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), 1)
+            self.addCleanup(os.close, fds[0])
+
+        self.assertEqual(msg, MSG)
+        self._test_pipe(fds[0], wfd, MSG)
 
 
 class FreeThreadingTests(unittest.TestCase):

From 45b28f67b5fb40ce905974716ab21340a6bcfd5d Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Wed, 15 Jan 2025 22:51:04 +0800
Subject: [PATCH 02/19] Add NEWS

---
 .../next/Library/2025-01-15-22-50-41.gh-issue-128881.JBL_9E.rst | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2025-01-15-22-50-41.gh-issue-128881.JBL_9E.rst

diff --git a/Misc/NEWS.d/next/Library/2025-01-15-22-50-41.gh-issue-128881.JBL_9E.rst b/Misc/NEWS.d/next/Library/2025-01-15-22-50-41.gh-issue-128881.JBL_9E.rst
new file mode 100644
index 00000000000000..4c259b8a26f03b
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-01-15-22-50-41.gh-issue-128881.JBL_9E.rst
@@ -0,0 +1,2 @@
+Fix ``flags`` and ``address`` parameters which were ignored in
+``socket.send_fds`` and ``socket.recv_fds``.

From fbb26680d698fb897384caf89281b0f7572070ce Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Wed, 15 Jan 2025 23:01:33 +0800
Subject: [PATCH 03/19] Only test MSG_DONTWAIT on Linux

---
 Lib/test/test_socket.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index ce65f90c5f4bb1..2d73b1d0cfd3e6 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7128,6 +7128,7 @@ def test_recv_fds_peek(self):
             self._test_pipe(fds[0], wfd, MSG)
 
     @requireAttrs(socket, "MSG_DONTWAIT")
+    @unittest.skipUnless(sys.platform in ('linux', 'android'), 'Linux specific test')
     def test_send_fds_dontwait(self):
         rfd, wfd = os.pipe()
         self.addCleanup(os.close, rfd)

From c58d2de6d27ae5bb1a0ed405aa10776de8d40cca Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Fri, 17 Jan 2025 00:30:53 +0800
Subject: [PATCH 04/19] Fix cleanup fds

---
 Lib/test/test_socket.py | 35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 2d73b1d0cfd3e6..b33252689ea848 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7037,6 +7037,12 @@ def test_dual_stack_client_v6(self):
 @requireAttrs(socket, "recv_fds")
 @requireAttrs(socket, "AF_UNIX")
 class SendRecvFdsTests(unittest.TestCase):
+    def _cleanup_fds(self, fds):
+        def close_fds(fds):
+            for fd in fds:
+                os.close(fd)
+        self.addCleanup(close_fds, fds)
+
     def _test_pipe(self, rfd, wfd, msg):
         assert len(msg) < 512
         os.write(wfd, msg)
@@ -7044,18 +7050,9 @@ def _test_pipe(self, rfd, wfd, msg):
         self.assertEqual(data, msg)
 
     def testSendAndRecvFds(self):
-        def close_pipes(pipes):
-            for fd1, fd2 in pipes:
-                os.close(fd1)
-                os.close(fd2)
-
-        def close_fds(fds):
-            for fd in fds:
-                os.close(fd)
-
         # send 10 file descriptors
         pipes = [os.pipe() for _ in range(10)]
-        self.addCleanup(close_pipes, pipes)
+        self._cleanup_fds(fd for pair in pipes for fd in pair)
         fds = [rfd for rfd, wfd in pipes]
 
         # use a UNIX socket pair to exchange file descriptors locally
@@ -7064,7 +7061,7 @@ def close_fds(fds):
             socket.send_fds(sock1, [MSG], fds)
             # request more data and file descriptors than expected
             msg, fds2, flags, addr = socket.recv_fds(sock2, len(MSG) * 2, len(fds) * 2)
-            self.addCleanup(close_fds, fds2)
+            self._cleanup_fds(fds2)
 
         self.assertEqual(msg, MSG)
         self.assertEqual(len(fds2), len(fds))
@@ -7091,14 +7088,13 @@ def test_send_recv_fds_with_addrs(self):
 
             socket.send_fds(sock1, [MSG], [rfd], address=sock2_addr)
             msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), 1)
-            new_rfd = fds[0]
-            self.addCleanup(os.close, new_rfd)
+            self._cleanup_fds(fds)
 
         self.assertEqual(msg, MSG)
         self.assertEqual(len(fds), 1)
         self.assertEqual(addr, sock1_addr)
 
-        self._test_pipe(new_rfd, wfd, MSG)
+        self._test_pipe(fds[0], wfd, MSG)
 
     @requireAttrs(socket, "MSG_PEEK")
     def test_recv_fds_peek(self):
@@ -7115,16 +7111,20 @@ def test_recv_fds_peek(self):
             peek_len = len(MSG) // 2
             msg, fds, flags, addr = socket.recv_fds(sock2, peek_len, 1,
                                                     socket.MSG_PEEK)
-            self.addCleanup(os.close, fds[0])
+            self._cleanup_fds(fds)
+
             self.assertEqual(len(msg), peek_len)
             self.assertEqual(msg, MSG[:peek_len])
             self.assertEqual(flags & socket.MSG_TRUNC, socket.MSG_TRUNC)
+            self.assertEqual(len(fds), 1)
             self._test_pipe(fds[0], wfd, MSG)
 
             # will raise BlockingIOError if MSG_PEEK didn't work
             msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), 1)
-            self.addCleanup(os.close, fds[0])
+            self._cleanup_fds(fds)
+
             self.assertEqual(msg, MSG)
+            self.assertEqual(len(fds), 1)
             self._test_pipe(fds[0], wfd, MSG)
 
     @requireAttrs(socket, "MSG_DONTWAIT")
@@ -7142,9 +7142,10 @@ def test_send_fds_dontwait(self):
                     socket.send_fds(sock1, [MSG], [rfd], socket.MSG_DONTWAIT)
 
             msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), 1)
-            self.addCleanup(os.close, fds[0])
+            self._cleanup_fds(fds)
 
         self.assertEqual(msg, MSG)
+        self.assertEqual(len(fds), 1)
         self._test_pipe(fds[0], wfd, MSG)
 
 

From aefccca1d15cfeb235d9dc791efd1d97f85e0c6a Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Fri, 17 Jan 2025 00:39:00 +0800
Subject: [PATCH 05/19] Skip platform-dependent tests

---
 Lib/test/test_socket.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index b33252689ea848..d80e45a75e6aa9 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7072,6 +7072,8 @@ def testSendAndRecvFds(self):
         for index, ((_, wfd), rfd) in enumerate(zip(pipes, fds2)):
             self._test_pipe(rfd, wfd, str(index).encode())
 
+    @unittest.skipUnless(sys.platform in ("linux", "android", "darwin"),
+                         "works on Linux and macOS")
     def test_send_recv_fds_with_addrs(self):
         sock1 = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
         sock2 = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
@@ -7097,6 +7099,7 @@ def test_send_recv_fds_with_addrs(self):
         self._test_pipe(fds[0], wfd, MSG)
 
     @requireAttrs(socket, "MSG_PEEK")
+    @unittest.skipUnless(sys.platform in ("linux", "android"), "works on Linux")
     def test_recv_fds_peek(self):
         rfd, wfd = os.pipe()
         self.addCleanup(os.close, rfd)
@@ -7128,7 +7131,7 @@ def test_recv_fds_peek(self):
             self._test_pipe(fds[0], wfd, MSG)
 
     @requireAttrs(socket, "MSG_DONTWAIT")
-    @unittest.skipUnless(sys.platform in ('linux', 'android'), 'Linux specific test')
+    @unittest.skipUnless(sys.platform in ("linux", "android"), "Linux specific test")
     def test_send_fds_dontwait(self):
         rfd, wfd = os.pipe()
         self.addCleanup(os.close, rfd)

From 6b58f4b6f74341f6eae18ee21edb9842a5c623a6 Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Sat, 18 Jan 2025 17:31:38 +0800
Subject: [PATCH 06/19] Apply suggestions from code review
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
---
 Lib/test/test_socket.py                                         | 2 +-
 .../next/Library/2025-01-15-22-50-41.gh-issue-128881.JBL_9E.rst | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index d80e45a75e6aa9..6d3864f0d5791f 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7113,7 +7113,7 @@ def test_recv_fds_peek(self):
             # peek message on sock2
             peek_len = len(MSG) // 2
             msg, fds, flags, addr = socket.recv_fds(sock2, peek_len, 1,
-                                                    socket.MSG_PEEK)
+                                                    flags=socket.MSG_PEEK)
             self._cleanup_fds(fds)
 
             self.assertEqual(len(msg), peek_len)
diff --git a/Misc/NEWS.d/next/Library/2025-01-15-22-50-41.gh-issue-128881.JBL_9E.rst b/Misc/NEWS.d/next/Library/2025-01-15-22-50-41.gh-issue-128881.JBL_9E.rst
index 4c259b8a26f03b..7c2a874e048d59 100644
--- a/Misc/NEWS.d/next/Library/2025-01-15-22-50-41.gh-issue-128881.JBL_9E.rst
+++ b/Misc/NEWS.d/next/Library/2025-01-15-22-50-41.gh-issue-128881.JBL_9E.rst
@@ -1,2 +1,2 @@
 Fix ``flags`` and ``address`` parameters which were ignored in
-``socket.send_fds`` and ``socket.recv_fds``.
+:func:`socket.send_fds` and :func:`socket.recv_fds`.

From 0134f01794b3e613d56a8c43a2413b145407fd53 Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Mon, 2 Jun 2025 11:21:58 +0800
Subject: [PATCH 07/19] fix test on FreeBSD

---
 Lib/test/test_socket.py | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index d6acc504827241..1baf70aa9c25ba 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7362,8 +7362,6 @@ def testSendAndRecvFds(self):
         for index, ((_, wfd), rfd) in enumerate(zip(pipes, fds2)):
             self._test_pipe(rfd, wfd, str(index).encode())
 
-    @unittest.skipUnless(sys.platform in ("linux", "android", "darwin"),
-                         "works on Linux and macOS")
     def test_send_recv_fds_with_addrs(self):
         sock1 = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
         sock2 = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
@@ -7379,10 +7377,18 @@ def test_send_recv_fds_with_addrs(self):
             sock2.setblocking(False)
 
             socket.send_fds(sock1, [MSG], [rfd], address=sock2_addr)
-            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), 1)
+            if sys.platform.startswith("freebsd"):
+                # FreeBSD requires at least CMSG_LEN(2 * sizeof(int)), otherwise
+                # the cmsg will be truncated
+                recv_fds_len = 2
+            else:
+                recv_fds_len = 1
+            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), recv_fds_len)
             self._cleanup_fds(fds)
 
         self.assertEqual(msg, MSG)
+        if hasattr(socket, "MSG_CTRUNC"):
+            self.assertEqual(flags & socket.MSG_CTRUNC, 0)
         self.assertEqual(len(fds), 1)
         self.assertEqual(addr, sock1_addr)
 
@@ -7409,6 +7415,8 @@ def test_recv_fds_peek(self):
             self.assertEqual(len(msg), peek_len)
             self.assertEqual(msg, MSG[:peek_len])
             self.assertEqual(flags & socket.MSG_TRUNC, socket.MSG_TRUNC)
+            if hasattr(socket, "MSG_CTRUNC"):
+                self.assertEqual(flags & socket.MSG_CTRUNC, 0)
             self.assertEqual(len(fds), 1)
             self._test_pipe(fds[0], wfd, MSG)
 
@@ -7417,6 +7425,8 @@ def test_recv_fds_peek(self):
             self._cleanup_fds(fds)
 
             self.assertEqual(msg, MSG)
+            if hasattr(socket, "MSG_CTRUNC"):
+                self.assertEqual(flags & socket.MSG_CTRUNC, 0)
             self.assertEqual(len(fds), 1)
             self._test_pipe(fds[0], wfd, MSG)
 

From 5cca1b41aa1459a77f96e00a1d0ea50af2981dcb Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Mon, 2 Jun 2025 12:05:16 +0800
Subject: [PATCH 08/19] fix test_send_fds_dontwait on *BSD

---
 Lib/test/test_socket.py | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 1baf70aa9c25ba..8679d8eadb4f46 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7431,20 +7431,27 @@ def test_recv_fds_peek(self):
             self._test_pipe(fds[0], wfd, MSG)
 
     @requireAttrs(socket, "MSG_DONTWAIT")
-    @unittest.skipUnless(sys.platform in ("linux", "android"), "Linux specific test")
     def test_send_fds_dontwait(self):
         rfd, wfd = os.pipe()
         self.addCleanup(os.close, rfd)
         self.addCleanup(os.close, wfd)
 
-        sock1, sock2 = socket.socketpair(socket.AF_UNIX, socket.SOCK_DGRAM)
+        # use SOCK_STREAM instead of SOCK_DGRAM to support *BSD platforms
+        # ref: https://docs.python.org/3/library/asyncio-protocol.html#datagram-protocols
+        sock1, sock2 = socket.socketpair(socket.AF_UNIX, socket.SOCK_STREAM)
         with sock1, sock2:
             sock1.setblocking(True)
             with self.assertRaises(BlockingIOError):
                 for _ in range(64 * 1024):
                     socket.send_fds(sock1, [MSG], [rfd], socket.MSG_DONTWAIT)
 
-            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), 1)
+            if sys.platform.startswith("freebsd"):
+                # FreeBSD requires at least CMSG_LEN(2 * sizeof(int)), otherwise
+                # the cmsg will be truncated
+                recv_fds_len = 2
+            else:
+                recv_fds_len = 1
+            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), recv_fds_len)
             self._cleanup_fds(fds)
 
         self.assertEqual(msg, MSG)

From 6c226c47759d6739c4a79c6efe64e640a291fbc4 Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Mon, 2 Jun 2025 15:30:35 +0800
Subject: [PATCH 09/19] skip sendmsg with MSG_DONTWAIT test on macOS

---
 Lib/test/test_socket.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 8679d8eadb4f46..efab99512e0742 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -3516,7 +3516,7 @@ def _testSendmsgTimeout(self):
     # Linux supports MSG_DONTWAIT when sending, but in general, it
     # only works when receiving.  Could add other platforms if they
     # support it too.
-    @skipWithClientIf(sys.platform not in {"linux", "android"},
+    @skipWithClientIf(sys.platform not in {"linux", "android", "freebsd"},
                       "MSG_DONTWAIT not known to work on this platform when "
                       "sending")
     def testSendmsgDontWait(self):
@@ -7431,6 +7431,9 @@ def test_recv_fds_peek(self):
             self._test_pipe(fds[0], wfd, MSG)
 
     @requireAttrs(socket, "MSG_DONTWAIT")
+    @unittest.skipIf(sys.platform in ("darwin",),
+                     "MSG_DONTWAIT not known to work on this platform when "
+                     "sending")
     def test_send_fds_dontwait(self):
         rfd, wfd = os.pipe()
         self.addCleanup(os.close, rfd)

From b13010897643b3949810a036cb4ad0edbd9e5c50 Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Mon, 2 Jun 2025 16:04:24 +0800
Subject: [PATCH 10/19] try enabling test_recv_fds_peek on macOS

---
 Lib/test/test_socket.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index efab99512e0742..0ac31e0eb8f6e6 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7395,7 +7395,9 @@ def test_send_recv_fds_with_addrs(self):
         self._test_pipe(fds[0], wfd, MSG)
 
     @requireAttrs(socket, "MSG_PEEK")
-    @unittest.skipUnless(sys.platform in ("linux", "android"), "works on Linux")
+    @unittest.skipUnless(sys.platform in ("linux", "android", "darwin"),
+                         "MSG_PEEK with SCM_RIGHTS not known to work on this "
+                         "platform")
     def test_recv_fds_peek(self):
         rfd, wfd = os.pipe()
         self.addCleanup(os.close, rfd)
@@ -7408,7 +7410,7 @@ def test_recv_fds_peek(self):
 
             # peek message on sock2
             peek_len = len(MSG) // 2
-            msg, fds, flags, addr = socket.recv_fds(sock2, peek_len, 1,
+            msg, fds, flags, addr = socket.recv_fds(sock2, peek_len, 2,
                                                     flags=socket.MSG_PEEK)
             self._cleanup_fds(fds)
 
@@ -7421,7 +7423,7 @@ def test_recv_fds_peek(self):
             self._test_pipe(fds[0], wfd, MSG)
 
             # will raise BlockingIOError if MSG_PEEK didn't work
-            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), 1)
+            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), 2)
             self._cleanup_fds(fds)
 
             self.assertEqual(msg, MSG)

From bb1c5adf94c2462705dfb8f8c14380c0d19b1f84 Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Mon, 2 Jun 2025 16:10:23 +0800
Subject: [PATCH 11/19] Revert "try enabling test_recv_fds_peek on macOS"

This reverts commit b13010897643b3949810a036cb4ad0edbd9e5c50.
---
 Lib/test/test_socket.py | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 0ac31e0eb8f6e6..efab99512e0742 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7395,9 +7395,7 @@ def test_send_recv_fds_with_addrs(self):
         self._test_pipe(fds[0], wfd, MSG)
 
     @requireAttrs(socket, "MSG_PEEK")
-    @unittest.skipUnless(sys.platform in ("linux", "android", "darwin"),
-                         "MSG_PEEK with SCM_RIGHTS not known to work on this "
-                         "platform")
+    @unittest.skipUnless(sys.platform in ("linux", "android"), "works on Linux")
     def test_recv_fds_peek(self):
         rfd, wfd = os.pipe()
         self.addCleanup(os.close, rfd)
@@ -7410,7 +7408,7 @@ def test_recv_fds_peek(self):
 
             # peek message on sock2
             peek_len = len(MSG) // 2
-            msg, fds, flags, addr = socket.recv_fds(sock2, peek_len, 2,
+            msg, fds, flags, addr = socket.recv_fds(sock2, peek_len, 1,
                                                     flags=socket.MSG_PEEK)
             self._cleanup_fds(fds)
 
@@ -7423,7 +7421,7 @@ def test_recv_fds_peek(self):
             self._test_pipe(fds[0], wfd, MSG)
 
             # will raise BlockingIOError if MSG_PEEK didn't work
-            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), 2)
+            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), 1)
             self._cleanup_fds(fds)
 
             self.assertEqual(msg, MSG)

From 02b0ddd5501769c35269a3e02faa5b7a3b981a05 Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Mon, 2 Jun 2025 18:46:41 +0800
Subject: [PATCH 12/19] Apply suggestions from code review
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

update comments

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
---
 Lib/test/test_socket.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index efab99512e0742..adf114cc7eb6fa 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7378,8 +7378,8 @@ def test_send_recv_fds_with_addrs(self):
 
             socket.send_fds(sock1, [MSG], [rfd], address=sock2_addr)
             if sys.platform.startswith("freebsd"):
-                # FreeBSD requires at least CMSG_LEN(2 * sizeof(int)), otherwise
-                # the cmsg will be truncated
+                # FreeBSD requires at least CMSG_LEN(2*sizeof(int)),
+                # otherwise the access control message is truncated.
                 recv_fds_len = 2
             else:
                 recv_fds_len = 1
@@ -7449,8 +7449,8 @@ def test_send_fds_dontwait(self):
                     socket.send_fds(sock1, [MSG], [rfd], socket.MSG_DONTWAIT)
 
             if sys.platform.startswith("freebsd"):
-                # FreeBSD requires at least CMSG_LEN(2 * sizeof(int)), otherwise
-                # the cmsg will be truncated
+                # FreeBSD requires at least CMSG_LEN(2*sizeof(int)),
+                # otherwise the access control message is truncated.
                 recv_fds_len = 2
             else:
                 recv_fds_len = 1

From 7368656402ecdc4c2d700b01fd764b89d63d5339 Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Mon, 2 Jun 2025 18:53:43 +0800
Subject: [PATCH 13/19] extract the logic into _recv_one_fd method

---
 Lib/test/test_socket.py | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index adf114cc7eb6fa..ee004ac539c9d0 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7339,6 +7339,16 @@ def _test_pipe(self, rfd, wfd, msg):
         data = os.read(rfd, 512)
         self.assertEqual(data, msg)
 
+    @staticmethod
+    def _recv_one_fd(sock, bufsize, flags=0):
+        if sys.platform.startswith("freebsd"):
+            # FreeBSD requires at least CMSG_LEN(2*sizeof(int)),
+            # otherwise the access control message is truncated.
+            max_fds = 2
+        else:
+            max_fds = 1
+        return socket.recv_fds(sock, bufsize, max_fds, flags)
+
     def testSendAndRecvFds(self):
         # send 10 file descriptors
         pipes = [os.pipe() for _ in range(10)]
@@ -7377,13 +7387,7 @@ def test_send_recv_fds_with_addrs(self):
             sock2.setblocking(False)
 
             socket.send_fds(sock1, [MSG], [rfd], address=sock2_addr)
-            if sys.platform.startswith("freebsd"):
-                # FreeBSD requires at least CMSG_LEN(2*sizeof(int)),
-                # otherwise the access control message is truncated.
-                recv_fds_len = 2
-            else:
-                recv_fds_len = 1
-            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), recv_fds_len)
+            msg, fds, flags, addr = self._recv_one_fd(sock2, len(MSG))
             self._cleanup_fds(fds)
 
         self.assertEqual(msg, MSG)
@@ -7448,13 +7452,7 @@ def test_send_fds_dontwait(self):
                 for _ in range(64 * 1024):
                     socket.send_fds(sock1, [MSG], [rfd], socket.MSG_DONTWAIT)
 
-            if sys.platform.startswith("freebsd"):
-                # FreeBSD requires at least CMSG_LEN(2*sizeof(int)),
-                # otherwise the access control message is truncated.
-                recv_fds_len = 2
-            else:
-                recv_fds_len = 1
-            msg, fds, flags, addr = socket.recv_fds(sock2, len(MSG), recv_fds_len)
+            msg, fds, flags, addr = self._recv_one_fd(sock2, len(MSG))
             self._cleanup_fds(fds)
 
         self.assertEqual(msg, MSG)

From 4f8d1ca57c2da27dd70088702c0598d198ae019f Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Mon, 2 Jun 2025 18:57:52 +0800
Subject: [PATCH 14/19] make sockets live only as little as possible

---
 Lib/test/test_socket.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index ee004ac539c9d0..e9f42726f985dc 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7373,13 +7373,13 @@ def testSendAndRecvFds(self):
             self._test_pipe(rfd, wfd, str(index).encode())
 
     def test_send_recv_fds_with_addrs(self):
-        sock1 = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
-        sock2 = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
         rfd, wfd = os.pipe()
         self.addCleanup(os.close, rfd)
         self.addCleanup(os.close, wfd)
 
-        with tempfile.TemporaryDirectory() as tmpdir, sock1, sock2:
+        with tempfile.TemporaryDirectory() as tmpdir, \
+                socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM) as sock1, \
+                socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM) as sock2:
             sock1_addr = os.path.join(tmpdir, "sock1")
             sock2_addr = os.path.join(tmpdir, "sock2")
             sock1.bind(sock1_addr)

From c42372306d4cd72aeff182419fe874c41353eed2 Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Sun, 22 Jun 2025 17:56:45 +0800
Subject: [PATCH 15/19] Apply suggestions from code review
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
---
 Lib/test/test_socket.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index e9f42726f985dc..8436523ecbe2fd 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7349,7 +7349,7 @@ def _recv_one_fd(sock, bufsize, flags=0):
             max_fds = 1
         return socket.recv_fds(sock, bufsize, max_fds, flags)
 
-    def testSendAndRecvFds(self):
+    def test_send_and_recv_fds(self):
         # send 10 file descriptors
         pipes = [os.pipe() for _ in range(10)]
         self._cleanup_fds(fd for pair in pipes for fd in pair)
@@ -7369,7 +7369,7 @@ def testSendAndRecvFds(self):
         # don't test addr
 
         # test that file descriptors are connected
-        for index, ((_, wfd), rfd) in enumerate(zip(pipes, fds2)):
+        for index, ((_, wfd), rfd) in enumerate(zip(pipes, fds2, strict=True)):
             self._test_pipe(rfd, wfd, str(index).encode())
 
     def test_send_recv_fds_with_addrs(self):
@@ -7412,6 +7412,7 @@ def test_recv_fds_peek(self):
 
             # peek message on sock2
             peek_len = len(MSG) // 2
+            self.assertGreater(peek_len, 0)
             msg, fds, flags, addr = socket.recv_fds(sock2, peek_len, 1,
                                                     flags=socket.MSG_PEEK)
             self._cleanup_fds(fds)

From 1dcd26f7acdbd7eb11107651331cbc640f1e185f Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Sun, 22 Jun 2025 18:13:01 +0800
Subject: [PATCH 16/19] rename flags to msg_flags

---
 Lib/socket.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Lib/socket.py b/Lib/socket.py
index 963e8292e01e76..856105a4fc54f4 100644
--- a/Lib/socket.py
+++ b/Lib/socket.py
@@ -579,14 +579,14 @@ def recv_fds(sock, bufsize, maxfds, flags=0):
 
         # Array of ints
         fds = array.array("i")
-        msg, ancdata, flags, addr = sock.recvmsg(bufsize,
+        msg, ancdata, msg_flags, addr = sock.recvmsg(bufsize,
             _socket.CMSG_LEN(maxfds * fds.itemsize), flags)
         for cmsg_level, cmsg_type, cmsg_data in ancdata:
             if (cmsg_level == _socket.SOL_SOCKET and cmsg_type == _socket.SCM_RIGHTS):
                 fds.frombytes(cmsg_data[:
                         len(cmsg_data) - (len(cmsg_data) % fds.itemsize)])
 
-        return msg, list(fds), flags, addr
+        return msg, list(fds), msg_flags, addr
     __all__.append("recv_fds")
 
 if hasattr(_socket.socket, "share"):

From 5d3e8969f5d9899fc8cf9b3a26a6e78c2846a516 Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Sun, 22 Jun 2025 18:15:19 +0800
Subject: [PATCH 17/19] also check flags in test_send_fds_dontwait

---
 Lib/test/test_socket.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 8436523ecbe2fd..33a936a22c2f3f 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7457,6 +7457,8 @@ def test_send_fds_dontwait(self):
             self._cleanup_fds(fds)
 
         self.assertEqual(msg, MSG)
+        if hasattr(socket, "MSG_CTRUNC"):
+            self.assertEqual(flags & socket.MSG_CTRUNC, 0)
         self.assertEqual(len(fds), 1)
         self._test_pipe(fds[0], wfd, MSG)
 

From d37ba0717b384fe7792b7ad3008c9e312c0d7d1d Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Sun, 22 Jun 2025 18:27:55 +0800
Subject: [PATCH 18/19] make 2 tests of MSG_DONTWAIT to be consistent

---
 Lib/test/test_socket.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 33a936a22c2f3f..062014ad556538 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -3513,10 +3513,11 @@ def _testSendmsgTimeout(self):
 
     # XXX: would be nice to have more tests for sendmsg flags argument.
 
-    # Linux supports MSG_DONTWAIT when sending, but in general, it
-    # only works when receiving.  Could add other platforms if they
+    # Linux and FreeBSD support MSG_DONTWAIT when sending, but in general,
+    # it only works when receiving.  Could add other platforms if they
     # support it too.
-    @skipWithClientIf(sys.platform not in {"linux", "android", "freebsd"},
+    @requireAttrs(socket, "MSG_DONTWAIT")
+    @skipWithClientIf(sys.platform in ("darwin",),
                       "MSG_DONTWAIT not known to work on this platform when "
                       "sending")
     def testSendmsgDontWait(self):

From f4c9d6773518e5edaa42be782a89d94e5064d1f5 Mon Sep 17 00:00:00 2001
From: GalaxySnail <me@glxys.nl>
Date: Sun, 22 Jun 2025 18:54:31 +0800
Subject: [PATCH 19/19] clarify PIPE_BUF in _test_pipe

---
 Lib/test/test_socket.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 062014ad556538..0ff91d3b6db07b 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -7335,9 +7335,11 @@ def close_fds(fds):
         self.addCleanup(close_fds, fds)
 
     def _test_pipe(self, rfd, wfd, msg):
-        assert len(msg) < 512
+        # POSIX requires PIPE_BUF to be at least 512 bytes.
+        PIPE_BUF = 512
+        assert len(msg) < PIPE_BUF
         os.write(wfd, msg)
-        data = os.read(rfd, 512)
+        data = os.read(rfd, PIPE_BUF)
         self.assertEqual(data, msg)
 
     @staticmethod