Added setuid() and setgid() to Unsafe.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@3653 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/util/unsafe/Linux/com_threerings_util_unsafe_Unsafe.c

@@ -55,6 +55,28 @@ Java_com_threerings_util_unsafe_Unsafe_nativeSleep (
     }
 }
 
+JNIEXPORT jboolean JNICALL
+Java_com_threerings_util_unsafe_Unsafe_nativeSetuid (
+    JNIEnv* env, jclass clazz, jint uid)
+{
+    if (setuid((uid_t)uid) != 0) {
+        fprintf(stderr, "setuid(%d) failed: %s\n", uid, strerror(errno));
+        return JNI_FALSE;
+    }
+    return JNI_TRUE;
+}
+
+JNIEXPORT jboolean JNICALL
+Java_com_threerings_util_unsafe_Unsafe_nativeSetgid (
+    JNIEnv* env, jclass clazz, jint gid)
+{
+    if (setgid((gid_t)gid) != 0) {
+        fprintf(stderr, "setgid(%d) failed: %s\n", gid, strerror(errno));
+        return JNI_FALSE;
+    }
+    return JNI_TRUE;
+}
+
 JNIEXPORT jboolean JNICALL
 Java_com_threerings_util_unsafe_Unsafe_init (JNIEnv* env, jclass clazz)
 {

src/java/com/threerings/util/unsafe/Unsafe.java

@@ -1,5 +1,5 @@
 //
-// $Id: Unsafe.java,v 1.2 2004/08/27 02:20:38 mdb Exp $
+// $Id$
 //
 // Narya library - tools for developing networked games
 // Copyright (C) 2002-2004 Three Rings Design, Inc., All Rights Reserved
@@ -71,6 +71,32 @@ public class Unsafe
         }
     }
 
+    /**
+     * Sets the processes uid to the specified value.
+     *
+     * @return true if the uid was changed, false if we were unable to do so.
+     */
+    public static boolean setuid (int uid)
+    {
+        if (_loaded && !RunAnywhere.isWindows()) {
+            return nativeSetuid(uid);
+        }
+        return false;
+    }
+
+    /**
+     * Sets the processes uid to the specified value.
+     *
+     * @return true if the uid was changed, false if we were unable to do so.
+     */
+    public static boolean setgid (int gid)
+    {
+        if (_loaded && !RunAnywhere.isWindows()) {
+            return nativeSetgid(gid);
+        }
+        return false;
+    }
+
     /**
      * Reenable garbage collection after a call to {@link #disableGC}.
      */
@@ -86,6 +112,16 @@ public class Unsafe
      */
     protected static native void nativeSleep (int millis);
 
+    /**
+     * Calls through to the native OS system call to change our uid.
+     */
+    protected static native boolean nativeSetuid (int uid);
+
+    /**
+     * Calls through to the native OS system call to change our gid.
+     */
+    protected static native boolean nativeSetgid (int gid);
+
     /**
      * Called to initialize our library.
      */