🐛 fix fast reuse outgoing port resulting in exception as we did not a…

…ssign SO_REUSEPORT or SO_REUSEADDR prior (#169)

CHANGES.rst

@@ -1,3 +1,10 @@
+2.11.906 (2024-10-26)
+=====================
+
+- Fixed unexpected exception when recreating a connection using the same outgoing port.
+  Add ``SO_REUSEPORT`` if available, fallback to ``SO_REUSEADDR``. This socket option
+  is not bullet proof against reusability errors. Some OS differs in behaviors.
+
 2.11.905 (2024-10-26)
 =====================
 

src/urllib3/_version.py

@@ -1,4 +1,4 @@
 # This file is protected via CODEOWNERS
 from __future__ import annotations
 
-__version__ = "2.11.905"
+__version__ = "2.11.906"

src/urllib3/backend/hface.py

@@ -1694,6 +1694,11 @@ def close(self) -> None:
                         ):  # don't want our goodbye, never mind then!
                             break
 
+            try:
+                self.sock.shutdown(0)
+            except (OSError, AttributeError):
+                pass
+
             try:
                 self.sock.close()
             except OSError:

src/urllib3/contrib/resolver/_async/protocols.py

@@ -109,6 +109,20 @@ async def create_connection(  # type: ignore[override]
             try:
                 sock = AsyncSocket(af, socktype, proto)
 
+                # we need to add this or reusing the same origin port will likely fail within
+                # short period of time. kernel put port on wait shut.
+                if source_address:
+                    try:
+                        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
+                    except (OSError, AttributeError):  # Defensive: very old OS?
+                        try:
+                            sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+                        except (
+                            OSError,
+                            AttributeError,
+                        ):  # Defensive: we can't do anything better than this.
+                            pass
+
                 # If provided, set socket level options before connecting.
                 _set_socket_options(sock, socket_options)
 

src/urllib3/contrib/resolver/protocols.py

@@ -219,6 +219,20 @@ def create_connection(
             try:
                 sock = socket.socket(af, socktype, proto)
 
+                # we need to add this or reusing the same origin port will likely fail within
+                # short period of time. kernel put port on wait shut.
+                if source_address is not None:
+                    try:
+                        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
+                    except (OSError, AttributeError):  # Defensive: very old OS?
+                        try:
+                            sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+                        except (
+                            OSError,
+                            AttributeError,
+                        ):  # Defensive: we can't do anything better than this.
+                            pass
+
                 # If provided, set socket level options before connecting.
                 _set_socket_options(sock, socket_options)
 

test/with_traefik/asynchronous/test_connection.py

@@ -193,3 +193,23 @@ async def test_quic_extract_ssl_ctx_ca_root(self) -> None:
 
         assert resp.status == 200
         assert resp.version == 30
+
+    @pytest.mark.xfail(
+        reason="experimental support for reusable outgoing port", strict=False
+    )
+    async def test_fast_reuse_outgoing_port(self) -> None:
+        for _ in range(4):
+            conn = AsyncHTTPSConnection(
+                self.host,
+                self.https_port,
+                ca_certs=self.ca_authority,
+                resolver=self.test_async_resolver.new(),
+                source_address=("0.0.0.0", 8745),
+            )
+
+            await conn.request("GET", "/get")
+            resp = await conn.getresponse()
+
+            assert resp.status == 200
+
+            await conn.close()

test/with_traefik/test_connection.py

@@ -191,3 +191,23 @@ def test_quic_extract_ssl_ctx_ca_root(self) -> None:
 
         assert resp.status == 200
         assert resp.version == 30
+
+    @pytest.mark.xfail(
+        reason="experimental support for reusable outgoing port", strict=False
+    )
+    def test_fast_reuse_outgoing_port(self) -> None:
+        for _ in range(4):
+            conn = HTTPSConnection(
+                self.host,
+                self.https_port,
+                ca_certs=self.ca_authority,
+                resolver=self.test_resolver.new(),
+                source_address=("0.0.0.0", 8845),
+            )
+
+            conn.request("GET", "/get")
+            resp = conn.getresponse()
+
+            assert resp.status == 200
+
+            conn.close()