ipsec-types: Add helper to parse interface ID

src/libstrongswan/ipsec/ipsec_types.c

@@ -147,3 +147,44 @@ bool mark_from_string(const char *value, mark_op_t ops, mark_t *mark)
 	}
 	return TRUE;
 }
+
+/*
+ * See header
+ */
+bool if_id_from_string(const char *value, uint32_t *if_id)
+{
+	char *endptr;
+
+	if (!value)
+	{
+		return FALSE;
+	}
+	if (strcasepfx(value, "%unique"))
+	{
+		endptr = (char*)value + strlen("%unique");
+		if (strcasepfx(endptr, "-dir"))
+		{
+			*if_id = IF_ID_UNIQUE_DIR;
+			endptr += strlen("-dir");
+		}
+		else if (!*endptr)
+		{
+			*if_id = IF_ID_UNIQUE;
+		}
+		else
+		{
+			DBG1(DBG_APP, "invalid interface ID: %s", value);
+			return FALSE;
+		}
+	}
+	else
+	{
+		*if_id = strtoul(value, &endptr, 0);
+	}
+	if (*endptr)
+	{
+		DBG1(DBG_APP, "invalid interface ID: %s", value);
+		return FALSE;
+	}
+	return TRUE;
+}

src/libstrongswan/ipsec/ipsec_types.h

@@ -240,4 +240,20 @@ enum mark_op_t {
  */
 bool mark_from_string(const char *value, mark_op_t ops, mark_t *mark);
 
+/**
+ * Special interface ID values to allocate a unique ID for each CHILD_SA/dir
+ */
+#define IF_ID_UNIQUE (0xFFFFFFFF)
+#define IF_ID_UNIQUE_DIR (0xFFFFFFFE)
+#define IF_ID_IS_UNIQUE(m) ((m) == IF_ID_UNIQUE || (m) == IF_ID_UNIQUE_DIR)
+
+/**
+ * Try to parse an interface ID from the given string.
+ *
+ * @param value		string to parse
+ * @param if_id		interface ID to fill
+ * @return			TRUE if parsing was successful
+ */
+bool if_id_from_string(const char *value, uint32_t *if_id);
+
 #endif /** IPSEC_TYPES_H_ @}*/

src/libstrongswan/tests/suites/test_utils.c

@@ -940,6 +940,49 @@ START_TEST(test_mark_from_string)
 }
 END_TEST
 
+/*******************************************************************************
+ * if_id_from_string
+ */
+
+static struct {
+	char *s;
+	bool ok;
+	uint32_t i;
+} if_id_data[] = {
+	{NULL,			FALSE,	0 },
+	{"",			TRUE,	0 },
+	{"/",			FALSE,	0 },
+	{"42",			TRUE,	42 },
+	{"0x42",		TRUE,	0x42 },
+	{"x",			FALSE,	0 },
+	{"42/",			FALSE,	0 },
+	{"42/0",		FALSE,	0 },
+	{"%unique",		TRUE,	IF_ID_UNIQUE },
+	{"%unique/",	FALSE,	0},
+	{"%unique0xffffffffff",	FALSE,	0},
+	{"0xffffffff",	TRUE,	IF_ID_UNIQUE},
+	{"%unique-dir",	TRUE,	IF_ID_UNIQUE_DIR},
+	{"%unique-dir/",FALSE,	0},
+	{"0xfffffffe",	TRUE,	IF_ID_UNIQUE_DIR},
+	{"%unique-",	FALSE,	0},
+	{"%unique-foo",	FALSE,	0},
+};
+
+START_TEST(test_if_id_from_string)
+{
+	uint32_t if_id;
+
+	if (if_id_from_string(if_id_data[_i].s, &if_id))
+	{
+		ck_assert_int_eq(if_id, if_id_data[_i].i);
+	}
+	else
+	{
+		ck_assert(!if_id_data[_i].ok);
+	}
+}
+END_TEST
+
 /*******************************************************************************
  * signature_schemes_for_key
  */
@@ -1087,6 +1130,10 @@ Suite *utils_suite_create()
 	tcase_add_loop_test(tc, test_mark_from_string, 0, countof(mark_data));
 	suite_add_tcase(s, tc);
 
+	tc = tcase_create("if_id_from_string");
+	tcase_add_loop_test(tc, test_if_id_from_string, 0, countof(if_id_data));
+	suite_add_tcase(s, tc);
+
 	tc = tcase_create("signature_schemes_for_key");
 	tcase_add_loop_test(tc, test_signature_schemes_for_key, 0, countof(scheme_data));
 	suite_add_tcase(s, tc);