openat-safer: new module

[gnulib.git] / tests / test-openat-safer.c

diff --git a/tests/test-openat-safer.c b/tests/test-openat-safer.c
new file mode 100644 (file)
index 0000000..a62477b
--- /dev/null
+++ b/tests/test-openat-safer.c
@@ -0,0 +1,122 @@
+/* Test that openat_safer leave standard fds alone.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Eric Blake <ebb9@byu.net>, 2009.  */
+
+#include <config.h>
+
+#include "fcntl--.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+/* This test intentionally closes stderr.  So, we arrange to have fd 10
+   (outside the range of interesting fd's during the test) set up to
+   duplicate the original stderr.  */
+
+#define BACKUP_STDERR_FILENO 10
+static FILE *myerr;
+
+#define ASSERT(expr) \
+  do                                                                         \
+    {                                                                        \
+      if (!(expr))                                                           \
+       {                                                                    \
+         fprintf (myerr, "%s:%d: assertion failed\n", __FILE__, __LINE__);  \
+         fflush (myerr);                                                    \
+         abort ();                                                          \
+       }                                                                    \
+    }                                                                        \
+  while (0)
+
+int
+main ()
+{
+  int i;
+  int j;
+  int dfd;
+  int fd;
+  char buf[2];
+  const char *witness = "test-openat-safer.txt";
+
+  /* We close fd 2 later, so save it in fd 10.  */
+  if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
+      || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
+    return 2;
+
+  /* Create handle for future use.  */
+  dfd = openat (AT_FDCWD, ".", O_RDONLY);
+  ASSERT (STDERR_FILENO < dfd);
+
+  /* Create file for later checks.  */
+  remove (witness);
+  fd = openat (dfd, witness, O_WRONLY | O_CREAT | O_EXCL, 0600);
+  ASSERT (STDERR_FILENO < fd);
+  ASSERT (write (fd, "hi", 2) == 2);
+  ASSERT (close (fd) == 0);
+
+  /* Four iterations, with progressively more standard descriptors
+     closed.  */
+  for (i = -1; i <= STDERR_FILENO; i++)
+    {
+      ASSERT (fchdir (dfd) == 0);
+      if (0 <= i)
+       ASSERT (close (i) == 0);
+
+      /* Execute once in ".", once in "..".  */
+      for (j = 0; j <= 1; j++)
+       {
+         if (j)
+           ASSERT (chdir ("..") == 0);
+
+         /* Check for error detection.  */
+         errno = 0;
+         ASSERT (openat (AT_FDCWD, "", O_RDONLY) == -1);
+         ASSERT (errno == ENOENT);
+         errno = 0;
+         ASSERT (openat (dfd, "", O_RDONLY) == -1);
+         ASSERT (errno == ENOENT);
+
+         /* Check for trailing slash and /dev/null handling; the
+            particular errno might be ambiguous.  */
+         errno = 0;
+         ASSERT (openat (dfd, "nonexist.ent/", O_CREAT | O_RDONLY,
+                         S_IRUSR | S_IWUSR) == -1);
+         /* ASSERT (errno == ENOTDIR); */
+         errno = 0;
+         ASSERT (openat (dfd, "/dev/null/", O_RDONLY) == -1);
+         /* ASSERT (errno == ENOTDIR); */
+         fd = openat (dfd, "/dev/null", O_RDONLY);
+         ASSERT (STDERR_FILENO < fd);
+         ASSERT (close (fd) == 0);
+
+         /* Check for our witness file.  */
+         fd = openat (dfd, witness, O_RDONLY | O_NOFOLLOW);
+         ASSERT (STDERR_FILENO < fd);
+         ASSERT (read (fd, buf, 2) == 2);
+         ASSERT (buf[0] == 'h' && buf[1] == 'i');
+         ASSERT (close (fd) == 0);
+       }
+    }
+  ASSERT (fchdir (dfd) == 0);
+  ASSERT (unlink (witness) == 0);
+  ASSERT (close (dfd) == 0);
+
+  return 0;
+}