#26907: add some missing getsockopt constants.

Patch by Christian Heimes, reviewed by Martin Panter.

Doc/library/socket.rst

@@ -281,6 +281,10 @@ Constants
    in the Unix header files are defined; for a few symbols, default values are
    provided.
 
+   .. versionchanged:: 3.6
+      ``SO_DOMAIN``, ``SO_PROTOCOL``, ``SO_PEERSEC``, ``SO_PASSSEC``
+      were added.
+
 .. data:: AF_CAN
           PF_CAN
           SOL_CAN_*

Doc/whatsnew/3.6.rst

@@ -406,6 +406,10 @@ The :func:`~socket.socket.ioctl` function now supports the :data:`~socket.SIO_LO
 control code.
 (Contributed by Daniel Stokes in :issue:`26536`.)
 
+The :meth:`~socket.socket.getsockopt` constants ``SO_DOMAIN``,
+``SO_PROTOCOL``, ``SO_PEERSEC``, and ``SO_PASSSEC`` are now supported.
+(Contributed by Christian Heimes in :issue:`26907`.)
+
 
 socketserver
 ------------

Modules/socketmodule.c

@@ -6582,6 +6582,12 @@ PyInit__socket(void)
 #ifdef  LOCAL_PEERCRED
     PyModule_AddIntMacro(m, LOCAL_PEERCRED);
 #endif
+#ifdef  SO_PASSSEC
+    PyModule_AddIntMacro(m, SO_PASSSEC);
+#endif
+#ifdef  SO_PEERSEC
+    PyModule_AddIntMacro(m, SO_PEERSEC);
+#endif
 #ifdef  SO_BINDTODEVICE
     PyModule_AddIntMacro(m, SO_BINDTODEVICE);
 #endif
@@ -6591,6 +6597,12 @@ PyInit__socket(void)
 #ifdef  SO_MARK
     PyModule_AddIntMacro(m, SO_MARK);
 #endif
+#ifdef SO_DOMAIN
+    PyModule_AddIntMacro(m, SO_DOMAIN);
+#endif
+#ifdef SO_PROTOCOL
+    PyModule_AddIntMacro(m, SO_PROTOCOL);
+#endif
 
     /* Maximum number of connections for "listen" */
 #ifdef  SOMAXCONN