Add IP_PORTRANGE* constants to the socket module

`IP_PORTRANGE*` can be used for getting/setting port ranges on a per socket
basis, as opposed to a system wide basis, in conjunction with calls like
`socket.getsockopt` and `socket.setsockopt`.

This functionality is available on \*BSD and Linux.

Signed-off-by: Enji Cooper <yaneurabeya@gmail.com>

Author: ngie-eign

Doc/library/socket.rst

@@ -348,6 +348,7 @@ Constants
           MSG_*
           SOL_*
           SCM_*
+          IP_PORTRANGE*
           IPPROTO_*
           IPPORT_*
           INADDR_*
@@ -544,6 +545,17 @@ Constants
 
    .. availability:: Linux >= 4.7.
 
+.. data:: IP_PORTRANGE
+          IP_PORTRANGE_DEFAULT
+          IP_PORTRANGE_HIGH
+          IP_PORTRANGE_LOW
+
+   These constants are available for manipulating port ranges on a socket-level
+   as opposed to system-level.
+
+   .. availability:: BSD, Linux
+   .. versionchanged:: 3.9
+
 Functions
 ^^^^^^^^^
 

Modules/socketmodule.c

@@ -7952,6 +7952,20 @@ PyInit__socket(void)
     PyModule_AddIntMacro(m, SYSPROTO_CONTROL);
 #endif
 
+    /* Unix-specific macros for setting */
+#ifdef  IP_PORTRANGE
+    PyModule_AddIntMacro(m, IP_PORTRANGE);
+#endif
+#ifdef  IP_PORTRANGE_DEFAULT
+    PyModule_AddIntMacro(m, IP_PORTRANGE_DEFAULT);
+#endif
+#ifdef  IP_PORTRANGE_HIGH
+    PyModule_AddIntMacro(m, IP_PORTRANGE_HIGH);
+#endif
+#ifdef  IP_PORTRANGE_LOW
+    PyModule_AddIntMacro(m, IP_PORTRANGE_LOW);
+#endif
+
     /* Some port configuration */
 #ifdef  IPPORT_RESERVED
     PyModule_AddIntMacro(m, IPPORT_RESERVED);