ostree/src/libotutil/ot-unix-utils.c

105 lines
3.1 KiB
C

/*
* Copyright (C) 2011 Colin Walters <walters@verbum.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Author: Colin Walters <walters@verbum.org>
*/
#include "config.h"
#include "otutil.h"
#include <gio/gio.h>
#include <glib/gstdio.h>
#include <gio/gunixoutputstream.h>
#include <string.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
/* Ensure that a pathname component @name does not contain the special Unix
* entries `.` or `..`, and does not contain `/`.
*/
gboolean
ot_util_filename_validate (const char *name,
GError **error)
{
if (strcmp (name, ".") == 0)
return glnx_throw (error, "Invalid self-referential filename '.'");
if (strcmp (name, "..") == 0)
return glnx_throw (error, "Invalid path uplink filename '..'");
if (strchr (name, '/') != NULL)
return glnx_throw (error, "Invalid / in filename %s", name);
if (!g_utf8_validate (name, -1, NULL))
return glnx_throw (error, "Invalid UTF-8 in filename %s", name);
return TRUE;
}
static GPtrArray *
ot_split_string_ptrarray (const char *str,
char c)
{
GPtrArray *ret = g_ptr_array_new_with_free_func (g_free);
const char *p;
do {
p = strchr (str, '/');
if (!p)
{
g_ptr_array_add (ret, g_strdup (str));
str = NULL;
}
else
{
g_ptr_array_add (ret, g_strndup (str, p - str));
str = p + 1;
}
} while (str && *str);
return ret;
}
/* Given a pathname @path, split it into individual entries in @out_components,
* validating that it does not have backreferences (`..`) etc.
*/
gboolean
ot_util_path_split_validate (const char *path,
GPtrArray **out_components,
GError **error)
{
if (strlen (path) > PATH_MAX)
return glnx_throw (error, "Path '%s' is too long", path);
g_autoptr(GPtrArray) ret_components = ot_split_string_ptrarray (path, '/');
/* Canonicalize by removing '.' and '', throw an error on .. */
for (int i = ret_components->len-1; i >= 0; i--)
{
const char *name = ret_components->pdata[i];
if (strcmp (name, "..") == 0)
return glnx_throw (error, "Invalid uplink '..' in path %s", path);
if (strcmp (name, ".") == 0 || name[0] == '\0')
g_ptr_array_remove_index (ret_components, i);
}
ot_transfer_out_value(out_components, &ret_components);
return TRUE;
}