Change the default --tmp-dir path to a more suitable path

In commit 4e1cc5f6dda22e9 the create_temp_filename() function was
reviewed and hardened, which in the end renamed this function to
create_temp_file() in commit 495e3cec5d156.

With these changes it became more evident that OpenVPN needs a directory
where it can create temporary files.  The create_temp_file() will create
such files f.ex. if --client-connect or --plugin which makes use of
the OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY hook, such as openvpn-auth-pam.so.

When this happens, OpenVPN will normally create these files in the directory
OpenVPN was started.  In many cases, this will fail due to restricted access.
By using --tmp-dir and pointing it to a directory writeable to the user
running OpenVPN, it works again.

This patch makes OpenVPN use a more suitable temproary directory by default,
instead of the current working directory.  On non-Windows platforms this
default value is set to '/tmp', but can be modified at compile-time by
running ./configure --with-tmp-dir-path=<TEMP DIR PATH>.  On Windows, it
will use GetTempPath() to find temporary paths recommended by the OS.  If
this fails, it will fallback to the old behaviour, using the directory
where OpenVPN was started.

In any cases, this default value can be overridden in the configuration
file by using the --tmp-dir option, as before.

To check what the default is at runime, you can see this easily by doing
this:

      $ ./openvpn --verb 4 --dev tun | grep tmp_dir

Signed-off-by: David Sommerseth <davids@redhat.com>
Tested-by: Jan Just Keijser <janjust@nikhef.nl>
Acked-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit ca4c6d618d743ec4a3b6f7ef8003d891603ec1a6)

diff --git a/options.c b/options.c
index 1117a0a752b53381f3ea820efc37e4e652b487c8..77089956660b6f0ebd5523db028ac06b2745d224 100644 (file)
--- a/options.c
+++ b/options.c
@@ -766,11 +766,23 @@ init_options (struct options *o, const bool init_gc)
 #ifdef ENABLE_X509ALTUSERNAME
   o->x509_username_field = X509_USERNAME_FIELD_DEFAULT;
 #endif
-#endif
-#endif
+#endif /* USE_SSL */
+#endif /* USE_CRYPTO */
 #ifdef ENABLE_PKCS11
   o->pkcs11_pin_cache_period = -1;
 #endif                 /* ENABLE_PKCS11 */
+
+  /* Set default --tmp-dir */
+#ifdef WIN32
+  /* On Windows, find temp dir via enviroment variables */
+  o->tmp_dir = win_get_tempdir();
+#else
+  /* Non-windows platforms use $TMPDIR, and if not set, default to '/tmp' */
+  o->tmp_dir = getenv("TMPDIR");
+  if( !o->tmp_dir ) {
+          o->tmp_dir = "/tmp";
+  }
+#endif /* WIN32 */
 }
 
 void
@@ -1916,8 +1928,6 @@ options_postprocess_verify_ce (const struct options *options, const struct conne
        msg (M_USAGE, "--client-connect requires --mode server");
       if (options->client_disconnect_script)
        msg (M_USAGE, "--client-disconnect requires --mode server");
-      if (options->tmp_dir)
-       msg (M_USAGE, "--tmp-dir requires --mode server");
       if (options->client_config_dir || options->ccd_exclusive)
        msg (M_USAGE, "--client-config-dir/--ccd-exclusive requires --mode server");
       if (options->enable_c2c)

diff --git a/win32.c b/win32.c
index 7c9901e012963d15a406e460e17fab1af56bca7e..2b7bf7b3c4d9ba8787c6cd09cfdb9d31d0461c82 100644 (file)
--- a/win32.c
+++ b/win32.c
@@ -1093,4 +1093,23 @@ env_set_add_win32 (struct env_set *es)
   set_win_sys_path (DEFAULT_WIN_SYS_PATH, es);
 }
 
+
+const char *
+win_get_tempdir()
+{
+  static char buf[MAX_PATH];
+  char *tmpdir = buf;
+
+  CLEAR(buf);
+
+  if (!GetTempPath(sizeof(buf),buf)) {
+    /* Warn if we can't find a valid temporary directory, which should
+     * be unlikely.
+     */
+    msg (M_WARN, "Could not find a suitable temporary directory."
+         " (GetTempPath() failed).  Consider to use --tmp-dir");
+    tmpdir = NULL;
+  }
+  return tmpdir;
+}
 #endif

diff --git a/win32.h b/win32.h
index fcc3062dfcc316da0320d3d50b30c29c857c3874..b6a162ea40605037d59d6c44d43e2bf275d92079 100644 (file)
--- a/win32.h
+++ b/win32.h
@@ -270,5 +270,8 @@ char *get_win_sys_path (void);
 /* call self in a subprocess */
 void fork_to_self (const char *cmdline);
 
+/* Find temporary directory */
+const char *win_get_tempdir();
+
 #endif
 #endif