pluto: Switch to user 'vpn' on Android.

src/charon/charon.c

@@ -41,7 +41,7 @@
 #include <threading/thread.h>
 
 #ifdef ANDROID
-#include <private/android_filesystem_config.h>
+#include <private/android_filesystem_config.h> /* for AID_VPN */
 #endif
 
 #ifndef LOG_AUTHPRIV /* not defined on OpenSolaris */

src/pluto/plutomain.c

@@ -81,6 +81,10 @@
 #include "whack_attribute.h"
 #include "pluto.h"
 
+#ifdef ANDROID
+#include <private/android_filesystem_config.h> /* for AID_VPN */
+#endif
+
 /**
  * Number of threads in the thread pool, if not specified in config.
  */
@@ -739,6 +743,13 @@ int main(int argc, char **argv)
 		}
 	}
 #endif
+#ifdef ANDROID
+	if (setuid(AID_VPN) != 0)
+	{
+		plog("unable to change daemon user");
+		abort();
+	}
+#endif
 
 #ifdef CAPABILITIES_LIBCAP
 	{