utils: add round_up/down() helper functions

diff --git a/src/libstrongswan/tests/test_utils.c b/src/libstrongswan/tests/test_utils.c
index 811882e538810da1d217b063d7b60f9c8239744c..d9f1726ff272a29eb010619a112fe95c0db6d081 100644 (file)
--- a/src/libstrongswan/tests/test_utils.c
+++ b/src/libstrongswan/tests/test_utils.c
@@ -165,6 +165,28 @@ START_TEST(test_untoh)
 }
 END_TEST
 
+/*******************************************************************************
+ * round_up/down
+ */
+
+START_TEST(test_round)
+{
+       ck_assert_int_eq(round_up(0, 4), 0);
+       ck_assert_int_eq(round_up(1, 4), 4);
+       ck_assert_int_eq(round_up(2, 4), 4);
+       ck_assert_int_eq(round_up(3, 4), 4);
+       ck_assert_int_eq(round_up(4, 4), 4);
+       ck_assert_int_eq(round_up(5, 4), 8);
+
+       ck_assert_int_eq(round_down(0, 4), 0);
+       ck_assert_int_eq(round_down(1, 4), 0);
+       ck_assert_int_eq(round_down(2, 4), 0);
+       ck_assert_int_eq(round_down(3, 4), 0);
+       ck_assert_int_eq(round_down(4, 4), 4);
+       ck_assert_int_eq(round_down(5, 4), 4);
+}
+END_TEST
+
 /*******************************************************************************
  * memxor
  */
@@ -416,6 +438,10 @@ Suite *utils_suite_create()
        tcase_add_test(tc, test_untoh);
        suite_add_tcase(s, tc);
 
+       tc = tcase_create("round");
+       tcase_add_test(tc, test_round);
+       suite_add_tcase(s, tc);
+
        tc = tcase_create("memxor");
        tcase_add_test(tc, test_memxor);
        tcase_add_test(tc, test_memxor_aligned);

diff --git a/src/libstrongswan/utils/utils.h b/src/libstrongswan/utils/utils.h
index 0e103de9cb248021445a621bbd5e4b41bb16cd81..d055f712d50447be9cf8570593f64101cb57e5e6 100644 (file)
--- a/src/libstrongswan/utils/utils.h
+++ b/src/libstrongswan/utils/utils.h
@@ -670,6 +670,29 @@ static inline u_int64_t untoh64(void *network)
 #endif
 }
 
+/**
+ * Round up size to be multiple of alignement
+ */
+static inline size_t round_up(size_t size, int alignement)
+{
+       int remainder;
+
+       remainder = size % alignement;
+       if (remainder)
+       {
+               size += alignement - remainder;
+       }
+       return size;
+}
+
+/**
+ * Round down size to be a multiple of alignement
+ */
+static inline size_t round_down(size_t size, int alignement)
+{
+       return size - (size % alignement);
+}
+
 /**
  * Special type to count references
  */