Added new core.c and core.h to add new function dleyna_core_prv_convert_udn_to_path to support persistent path identifier

2 files changed, 146 insertions, 0 deletions

diff --git a/libdleyna/core/core.c b/libdleyna/core/core.c
new file mode 100644
index 0000000..8d9bdda
--- /dev/null
+++ b/libdleyna/core/core.c
@@ -0,0 +1,73 @@
+/*
+ * dLeyna
+ *
+ * Copyright (C) 2012-2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 2.1, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Rick Bell <richard.s.bell@intel.com>
+ *
+ */
+
+#include <string.h>
+
+#include "core.h"
+
+gchar *dleyna_core_prv_convert_udn_to_path(const gchar *udn)
+{
+	gchar *uuid;
+	size_t len;
+	size_t dest_len;
+	size_t i;
+
+	/* This function will generate a valid dbus path from the udn
+	 * We are not going to check the UDN validity. We will try to
+	 * convert it anyway. To avoid any security problem, we will
+	 * check some limits and possibly return only a partial
+	 * UDN. For a better understanding, a valid UDN should be:
+	 * UDN = "uuid:4Hex-2Hex-2Hex-2Hex-6Hex"
+	 *
+	 * The convertion rules are:
+	 * 1 - An invalid char will be escaped using its hexa representation
+	 *     prefixed with '_': 
+	 *         Example 1 ':  ' -> '_3A'
+	 *         Example 2 '-  ' -> '_2D'
+	 * 2 - The max size of the converted UDN can be 3 times the original
+	 *     size (if all char are not dbus compliant).
+	 *     The max size of a dbus path is an UINT32: G_MAXUINT32
+	 *     We will limit the of the converted string size to G_MAXUINT32 / 2
+	 *     otherwise we will never have space to generate object path.
+	 */
+
+	len = strlen(udn);
+	dest_len = MIN(len * 3, G_MAXUINT32 / 2);
+
+	uuid = g_malloc(dest_len + 1);
+	i = 0;
+
+	while (*udn && (i < dest_len))
+	{
+		if (g_ascii_isalnum(*udn) || (*udn == '_'))
+			uuid[i++] = *udn;
+		else
+			i += g_snprintf(uuid + i, dest_len + 1,"_%02x", *udn);
+
+		udn++;
+	}
+
+
+	uuid[i]=0;
+
+	return uuid;
+}
diff --git a/libdleyna/core/core.h b/libdleyna/core/core.h
new file mode 100644
index 0000000..8d9bdda
--- /dev/null
+++ b/libdleyna/core/core.h
@@ -0,0 +1,73 @@
+/*
+ * dLeyna
+ *
+ * Copyright (C) 2012-2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 2.1, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Rick Bell <richard.s.bell@intel.com>
+ *
+ */
+
+#include <string.h>
+
+#include "core.h"
+
+gchar *dleyna_core_prv_convert_udn_to_path(const gchar *udn)
+{
+	gchar *uuid;
+	size_t len;
+	size_t dest_len;
+	size_t i;
+
+	/* This function will generate a valid dbus path from the udn
+	 * We are not going to check the UDN validity. We will try to
+	 * convert it anyway. To avoid any security problem, we will
+	 * check some limits and possibly return only a partial
+	 * UDN. For a better understanding, a valid UDN should be:
+	 * UDN = "uuid:4Hex-2Hex-2Hex-2Hex-6Hex"
+	 *
+	 * The convertion rules are:
+	 * 1 - An invalid char will be escaped using its hexa representation
+	 *     prefixed with '_': 
+	 *         Example 1 ':  ' -> '_3A'
+	 *         Example 2 '-  ' -> '_2D'
+	 * 2 - The max size of the converted UDN can be 3 times the original
+	 *     size (if all char are not dbus compliant).
+	 *     The max size of a dbus path is an UINT32: G_MAXUINT32
+	 *     We will limit the of the converted string size to G_MAXUINT32 / 2
+	 *     otherwise we will never have space to generate object path.
+	 */
+
+	len = strlen(udn);
+	dest_len = MIN(len * 3, G_MAXUINT32 / 2);
+
+	uuid = g_malloc(dest_len + 1);
+	i = 0;
+
+	while (*udn && (i < dest_len))
+	{
+		if (g_ascii_isalnum(*udn) || (*udn == '_'))
+			uuid[i++] = *udn;
+		else
+			i += g_snprintf(uuid + i, dest_len + 1,"_%02x", *udn);
+
+		udn++;
+	}
+
+
+	uuid[i]=0;
+
+	return uuid;
+}