libs/libc/unistd: Stubs for setuid and setgid. Added stubbed implementations of setuid and setgid. These functions are essentially stubs pretending that NuttX supported users and groups and that the only configured user and group in the system were both 'root' with a uid and a gid of 0, respectively. The intent is not to provide meaningful new features, but to ease porting of foreign source code to NuttX.

include/errno.h

@@ -45,6 +45,7 @@
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
+
 /* How can we access the errno variable? */
 
 #if !defined(CONFIG_BUILD_PROTECTED) && !defined(CONFIG_BUILD_KERNEL)
@@ -87,7 +88,8 @@
 
 #  else
    /* User libraries for the kernel.  Only indirect access from user
-    * libraries */
+    * libraries
+   */
 
 #    undef __DIRECT_ERRNO_ACCESS
 #  endif

include/unistd.h

@@ -368,6 +368,11 @@ int     sethostname(FAR const char *name, size_t size);
 
 long    sysconf(int name);
 
+/* User and group identity management */
+
+int     setuid(uid_t uid);
+int     setgid(gid_t gid);
+
 #undef EXTERN
 #if defined(__cplusplus)
 }