Issue #13777: Add PF_SYSTEM sockets on OS X.
Patch by Michael Goderbauer.
diff --git a/Modules/socketmodule.h b/Modules/socketmodule.h
index 59d4cb1..0435878 100644
--- a/Modules/socketmodule.h
+++ b/Modules/socketmodule.h
@@ -80,6 +80,13 @@
 #include <linux/can/raw.h>
 #endif
 
+#ifdef HAVE_SYS_SYS_DOMAIN_H
+#include <sys/sys_domain.h>
+#endif
+#ifdef HAVE_SYS_KERN_CONTROL_H
+#include <sys/kern_control.h>
+#endif
+
 #ifndef Py__SOCKET_H
 #define Py__SOCKET_H
 #ifdef __cplusplus
@@ -138,6 +145,9 @@
 #ifdef HAVE_LINUX_CAN_H
     struct sockaddr_can can;
 #endif
+#ifdef HAVE_SYS_KERN_CONTROL_H
+    struct sockaddr_ctl ctl;
+#endif
 } sock_addr_t;
 
 /* The object holding a socket.  It holds some extra information,