Moved over lib/util_sec (with added fixes) as the HEAD source

seems to have drifted a little.
Jeremy.
(This used to be commit ebcdb4afee04cc3b94e60b1de86c2b534d4e233e)

diff --git a/source3/lib/util_sec.c b/source3/lib/util_sec.c
index 4a2ac2565e677b6e2a983b766cd6ccfca1947358..4306a94191dc4a404ae5270d78355da5b716ceec 100644 (file)
--- a/source3/lib/util_sec.c
+++ b/source3/lib/util_sec.c
@@ -30,6 +30,8 @@ extern int DEBUGLEVEL;
 #endif
 #include <stdlib.h>
 #include <stdio.h>
+#include <sys/types.h>
+#include <errno.h>
 
 #ifdef HAVE_SYS_PRIV_H
 #include <sys/priv.h>
@@ -201,9 +203,21 @@ void save_re_uid(void)
 void restore_re_uid(void)
 {
        set_effective_uid(0);
+
+#if USE_SETRESUID
+       setresuid(saved_ruid, saved_euid, -1);
+#elif USE_SETREUID
+       setreuid(saved_ruid, -1);
+       setreuid(-1,saved_euid);
+#elif USE_SETUIDX
+       setuidx(ID_REAL, saved_ruid);
+       setuidx(ID_EFFECTIVE, saved_euid);
+#else
        set_effective_uid(saved_euid);
-       if (getuid() != saved_ruid) setuid(saved_ruid);
+       if (getuid() != saved_ruid)
+               setuid(saved_ruid);
        set_effective_uid(saved_euid);
+#endif
 
        assert_uid(saved_ruid, saved_euid);
 }
@@ -291,6 +305,35 @@ void become_user_permanently(uid_t uid, gid_t gid)
        assert_gid(gid, gid);
 }
 
+
+/****************************************************************************
+this function just checks that we don't get ENOSYS back
+****************************************************************************/
+static int have_syscall(void)
+{
+       errno = 0;
+
+#if USE_SETRESUID
+       setresuid(-1,-1,-1);
+#endif
+
+#if USE_SETREUID
+       setreuid(-1,-1);
+#endif
+
+#if USE_SETEUID
+       seteuid(-1);
+#endif
+
+#if USE_SETUIDX
+       setuidx(ID_EFFECTIVE, -1);
+#endif
+
+       if (errno == ENOSYS) return -1;
+       
+       return 0;
+}
+
 #ifdef AUTOCONF_TEST
 main()
 {
@@ -301,15 +344,18 @@ main()
                exit(1);
 #endif
 
-               /* assume that if we have the functions then they work */
-                fprintf(stderr,"not running as root: assuming OK\n");
-               exit(0);
+               /* if not running as root then at least check to see if we get ENOSYS - this 
+                  handles Linux 2.0.x with glibc 2.1 */
+                fprintf(stderr,"not running as root: checking for ENOSYS\n");
+               exit(have_syscall());
        }
 
        gain_root_privilege();
        gain_root_group_privilege();
        set_effective_gid(1);
        set_effective_uid(1);
+       save_re_uid();
+       restore_re_uid();
        gain_root_privilege();
        gain_root_group_privilege();
        become_user_permanently(1, 1);