Fix sys_reset_uid_gid; minor changes in genfile.c

* lib/system.h (ERRNO_IS_EACCES): Remove.  Not used anymore.
(sys_reset_uid_gid): Re-initialize supplementary groups when
switching privileges. Fix ordering of setgid and setuid calls.
* tests/genfile.c (EXIT_USAGE)
(EXIT_UNAVAILABLE): New exit codes.
Use them as appropriate.

2 files changed, 38 insertions, 18 deletions

diff --git a/lib/system.h b/lib/system.h
index e7f531c..dffab86 100644
--- a/lib/system.h
+++ b/lib/system.h
@@ -470,19 +470,37 @@ char *getenv ();
 #if MSDOS
 # include <process.h>
 # define SET_BINARY_MODE(arc) setmode(arc, O_BINARY)
-# define ERRNO_IS_EACCES errno == EACCES
 # define mkdir(file, mode) (mkdir) (file)
 # define TTY_NAME "con"
 # define sys_reset_uid_gid()
 #else
 # define SET_BINARY_MODE(arc)
-# define ERRNO_IS_EACCES 0
 # define TTY_NAME "/dev/tty"
-# define sys_reset_uid_gid()					\
-  do {								\
-    if (! (setuid (getuid ()) == 0 && setgid (getgid ()) == 0)) \
-      abort ();							\
-  } while (0)
+# include <paxlib.h>
+static inline void
+sys_reset_uid_gid (void)
+{
+  struct passwd *pw;
+  uid_t uid = getuid ();
+  gid_t gid = getgid ();
+  
+  if ((pw = getpwuid (uid)) == NULL)
+    {
+      FATAL_ERROR ((0, errno, "%s(%ld)", "getpwuid", (unsigned long)uid));
+    }
+  if (initgroups (pw->pw_name, getgid ()))
+    {
+      FATAL_ERROR ((0, errno, "%s", "initgroups"));
+    }
+  if (gid != getegid () && setgid (gid) && errno != EPERM)
+    {
+      FATAL_ERROR ((0, errno, "%s", "setgid"));
+    }
+  if (uid != geteuid () && setuid (uid) && errno != EPERM)
+    {
+      FATAL_ERROR ((0, errno, "%s", "setuid"));
+    }
+}
 #endif
 
 #if XENIX
diff --git a/tests/genfile.c b/tests/genfile.c
index dc822c7..284d762 100644
--- a/tests/genfile.c
+++ b/tests/genfile.c
@@ -40,6 +40,8 @@
 #ifndef EXIT_FAILURE
 # define EXIT_FAILURE 1
 #endif
+#define EXIT_USAGE 2
+#define EXIT_UNAVAILABLE 3
 
 #if ! defined SIGCHLD && defined SIGCLD
 # define SIGCHLD SIGCLD
@@ -242,15 +244,15 @@ get_size (const char *str, int allow_zero)
       if (9 < (unsigned) digit)
 	{
 	  if (xlat_suffix (&v, p))
-	    error (EXIT_FAILURE, 0, _("Invalid size: %s"), str);
+	    error (EXIT_USAGE, 0, _("Invalid size: %s"), str);
 	  else
 	    break;
 	}
       else if (x / 10 != v)
-	error (EXIT_FAILURE, 0, _("Number out of allowed range: %s"), str);
+	error (EXIT_USAGE, 0, _("Number out of allowed range: %s"), str);
       v = x + digit;
       if (v < 0)
-	error (EXIT_FAILURE, 0, _("Negative size: %s"), str);
+	error (EXIT_USAGE, 0, _("Negative size: %s"), str);
     }
   return v;
 }
@@ -270,7 +272,7 @@ verify_file (char *file_name)
 	       (unsigned long)st.st_size, (unsigned long)file_length);
 
       if (!quiet && mode == mode_sparse && !ST_IS_SPARSE (st))
-	error (EXIT_FAILURE, 0, _("created file is not sparse"));
+	error (EXIT_UNAVAILABLE, 0, _("created file is not sparse"));
     }
 }
 
@@ -565,7 +567,7 @@ generate_sparse_file (int argc, char **argv)
   int flags = O_CREAT | O_RDWR | O_BINARY;
 
   if (!file_name)
-    error (EXIT_FAILURE, 0,
+    error (EXIT_USAGE, 0,
 	   _("cannot generate sparse files on standard output, use --file option"));
   if (!seek_offset)
     flags |= O_TRUNC;
@@ -657,13 +659,13 @@ print_stat (const char *name)
 	      if (*q)
 		{
 		  printf ("\n");
-		  error (EXIT_FAILURE, 0, _("incorrect mask (near `%s')"), q);
+		  error (EXIT_USAGE, 0, _("incorrect mask (near `%s')"), q);
 		}
 	    }
 	  else if (p[4])
 	    {
 	      printf ("\n");
-	      error (EXIT_FAILURE, 0, _("Unknown field `%s'"), p);
+	      error (EXIT_USAGE, 0, _("Unknown field `%s'"), p);
 	    }
 	  printf ("%0o", val);
 	}
@@ -696,7 +698,7 @@ print_stat (const char *name)
       else
 	{
 	  printf ("\n");
-	  error (EXIT_FAILURE, 0, _("Unknown field `%s'"), p);
+	  error (EXIT_USAGE, 0, _("Unknown field `%s'"), p);
 	}
       p = strtok (NULL, ",");
       if (p)
@@ -952,7 +954,7 @@ main (int argc, char **argv)
   /* Decode command options.  */
 
   if (argp_parse (&argp, argc, argv, 0, &index, NULL))
-    exit (EXIT_FAILURE);
+    exit (EXIT_USAGE);
 
   argc -= index;
   argv += index;
@@ -961,7 +963,7 @@ main (int argc, char **argv)
     {
     case mode_stat:
       if (argc == 0)
-	error (EXIT_FAILURE, 0, _("--stat requires file names"));
+	error (EXIT_USAGE, 0, _("--stat requires file names"));
 
       while (argc--)
 	print_stat (*argv++);
@@ -974,7 +976,7 @@ main (int argc, char **argv)
 
     case mode_generate:
       if (argc)
-	error (EXIT_FAILURE, 0, _("too many arguments"));
+	error (EXIT_USAGE, 0, _("too many arguments"));
       if (files_from)
 	generate_files_from_list ();
       else