tar: live within system-supplied limits on file descriptors

[chaz/tar] / src / tar.c

diff --git a/src/tar.c b/src/tar.c
index 10ba8a9b8a06bf2a9709008e6bf9a3d8d731f7bf..6fd117c636702f564511be0d3c7c4876b849efdb 100644 (file)
--- a/src/tar.c
+++ b/src/tar.c
@@ -74,7 +74,7 @@
 static const char *stdin_used_by;
 
 /* Doesn't return if stdin already requested.  */
-void
+static void
 request_stdin (const char *option)
 {
   if (stdin_used_by)
@@ -1509,7 +1509,7 @@ parse_opt (int key, char *arg, struct argp_state *state)
       {
        uintmax_t u;
        char *p;
-       
+
        if (xstrtoumax (arg, &p, 10, &u, TAR_SIZE_SUFFIXES) != LONGINT_OK)
          USAGE_ERROR ((0, 0, "%s: %s", quotearg_colon (arg),
                        _("Invalid tape length")));
@@ -1968,7 +1968,7 @@ parse_opt (int key, char *arg, struct argp_state *state)
     case RECORD_SIZE_OPTION:
       {
        uintmax_t u;
-       
+
        if (! (xstrtoumax (arg, NULL, 10, &u, TAR_SIZE_SUFFIXES) == LONGINT_OK
               && u == (size_t) u))
          USAGE_ERROR ((0, 0, "%s: %s", quotearg_colon (arg),
@@ -2465,6 +2465,18 @@ decode_options (int argc, char **argv)
   if (recursive_unlink_option)
     old_files_option = UNLINK_FIRST_OLD_FILES;
 
+  /* Flags for accessing files to be read from or copied into.  POSIX says
+     O_NONBLOCK has unspecified effect on most types of files, but in
+     practice it never harms and sometimes helps.  */
+  {
+    int base_open_flags =
+      (O_BINARY | O_CLOEXEC | O_NOCTTY | O_NONBLOCK
+       | (dereference_option ? 0 : O_NOFOLLOW)
+       | (atime_preserve_option == system_atime_preserve ? O_NOATIME : 0));
+    open_read_flags = O_RDONLY | base_open_flags;
+    open_searchdir_flags = O_SEARCH | O_DIRECTORY | base_open_flags;
+  }
+  fstatat_flags = dereference_option ? 0 : AT_SYMLINK_NOFOLLOW;
 
   if (subcommand_option == TEST_LABEL_SUBCOMMAND)
     {
@@ -2494,8 +2506,8 @@ decode_options (int argc, char **argv)
                      _("Cowardly refusing to create an empty archive")));
       if (args.compress_autodetect && archive_names
          && strcmp (archive_name_array[0], "-"))
-       set_comression_program_by_suffix (archive_name_array[0],
-                                         use_compress_program_option);
+       set_compression_program_by_suffix (archive_name_array[0],
+                                          use_compress_program_option);
       break;
 
     case EXTRACT_SUBCOMMAND:
@@ -2676,9 +2688,31 @@ tar_stat_init (struct tar_stat_info *st)
   memset (st, 0, sizeof (*st));
 }
 
+/* Close the stream or file descriptor associated with ST, and remove
+   all traces of it from ST.  Return true if successful, false (with a
+   diagnostic) otherwise.  */
+bool
+tar_stat_close (struct tar_stat_info *st)
+{
+  int status = (st->dirstream ? closedir (st->dirstream)
+               : 0 < st->fd ? close (st->fd)
+               : 0);
+  st->dirstream = 0;
+  st->fd = 0;
+
+  if (status == 0)
+    return true;
+  else
+    {
+      close_diag (st->orig_file_name);
+      return false;
+    }
+}
+
 void
 tar_stat_destroy (struct tar_stat_info *st)
 {
+  tar_stat_close (st);
   free (st->orig_file_name);
   free (st->file_name);
   free (st->link_name);