Now that there are helpers for converting IP tunnel flags between the
old __be16 format and the bitmap format, make sure they work as expected
by adding a couple of tests to the bitmap testing suite. The helpers are
all inline, so no dependencies on the related CONFIG_* (or a standalone
module) are needed.

Cover three possible cases:

1. No bits past BIT(15) are set, VTI/SIT bits are not set. This
   conversion is almost a direct assignment.
2. No bits past BIT(15) are set, but VTI/SIT bit is set. During the
   conversion, it must be transformed into BIT(16) in the bitmap,
   but still compatible with the __be16 format.
3. The bitmap has bits past BIT(15) set (not the VTI/SIT one). The
   result will be truncated.
   Note that currently __IP_TUNNEL_FLAG_NUM is 17 (incl. special),
   which means that the result of this case is currently
   semi-false-positive. When BIT(17) is finally here, it will be
   adjusted accordingly.

Signed-off-by: Alexander Lobakin <aleksander.loba...@intel.com>
---
 lib/test_bitmap.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 105 insertions(+)

diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index a005fcd70ed7..2981277ed8d4 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -14,6 +14,8 @@
 #include <linux/string.h>
 #include <linux/uaccess.h>
 
+#include <net/ip_tunnels.h>
+
 #include "../tools/testing/selftests/kselftest_module.h"
 
 #define EXP1_IN_BITS   (sizeof(exp1) * 8)
@@ -1387,6 +1389,108 @@ static void __init test_bitmap_write_perf(void)
 
 #undef TEST_BIT_LEN
 
+struct ip_tunnel_flags_test {
+       const u16       *src_bits;
+       const u16       *exp_bits;
+       u8              src_num;
+       u8              exp_num;
+       __be16          exp_val;
+       bool            exp_comp:1;
+};
+
+#define IP_TUNNEL_FLAGS_TEST(src, comp, eval, exp) {   \
+       .src_bits       = (src),                        \
+       .src_num        = ARRAY_SIZE(src),              \
+       .exp_comp       = (comp),                       \
+       .exp_val        = (eval),                       \
+       .exp_bits       = (exp),                        \
+       .exp_num        = ARRAY_SIZE(exp),              \
+}
+
+/* These are __be16-compatible and can be compared as is */
+static const u16 ip_tunnel_flags_1[] __initconst = {
+       IP_TUNNEL_KEY_BIT,
+       IP_TUNNEL_STRICT_BIT,
+       IP_TUNNEL_ERSPAN_OPT_BIT,
+};
+
+/*
+ * Due to the previous flags design limitation, setting either
+ * ``IP_TUNNEL_CSUM_BIT`` (on Big Endian) or ``IP_TUNNEL_DONT_FRAGMENT_BIT``
+ * (on Little) also sets VTI/ISATAP bit. In the bitmap implementation, they
+ * correspond to ``BIT(16)``, which is bigger than ``U16_MAX``, but still is
+ * backward-compatible.
+ */
+#ifdef __BIG_ENDIAN
+#define IP_TUNNEL_CONFLICT_BIT IP_TUNNEL_CSUM_BIT
+#else
+#define IP_TUNNEL_CONFLICT_BIT IP_TUNNEL_DONT_FRAGMENT_BIT
+#endif
+
+static const u16 ip_tunnel_flags_2_src[] __initconst = {
+       IP_TUNNEL_CONFLICT_BIT,
+};
+
+static const u16 ip_tunnel_flags_2_exp[] __initconst = {
+       IP_TUNNEL_CONFLICT_BIT,
+       IP_TUNNEL_SIT_ISATAP_BIT,
+};
+
+/* Bits 17 and higher are not compatible with __be16 flags */
+static const u16 ip_tunnel_flags_3_src[] __initconst = {
+       IP_TUNNEL_VXLAN_OPT_BIT,
+       17,
+       18,
+       20,
+};
+
+static const u16 ip_tunnel_flags_3_exp[] __initconst = {
+       IP_TUNNEL_VXLAN_OPT_BIT,
+};
+
+static const struct ip_tunnel_flags_test ip_tunnel_flags_test[] __initconst = {
+       IP_TUNNEL_FLAGS_TEST(ip_tunnel_flags_1, true,
+                            cpu_to_be16(BIT(IP_TUNNEL_KEY_BIT) |
+                                        BIT(IP_TUNNEL_STRICT_BIT) |
+                                        BIT(IP_TUNNEL_ERSPAN_OPT_BIT)),
+                            ip_tunnel_flags_1),
+       IP_TUNNEL_FLAGS_TEST(ip_tunnel_flags_2_src, true, VTI_ISVTI,
+                            ip_tunnel_flags_2_exp),
+       IP_TUNNEL_FLAGS_TEST(ip_tunnel_flags_3_src,
+                            /*
+                             * This must be set to ``false`` once
+                             * ``__IP_TUNNEL_FLAG_NUM`` goes above 17.
+                             */
+                            true,
+                            cpu_to_be16(BIT(IP_TUNNEL_VXLAN_OPT_BIT)),
+                            ip_tunnel_flags_3_exp),
+};
+
+static void __init test_ip_tunnel_flags(void)
+{
+       for (u32 i = 0; i < ARRAY_SIZE(ip_tunnel_flags_test); i++) {
+               typeof(*ip_tunnel_flags_test) *test = &ip_tunnel_flags_test[i];
+               IP_TUNNEL_DECLARE_FLAGS(src) = { };
+               IP_TUNNEL_DECLARE_FLAGS(exp) = { };
+               IP_TUNNEL_DECLARE_FLAGS(out);
+
+               for (u32 j = 0; j < test->src_num; j++)
+                       __set_bit(test->src_bits[j], src);
+
+               for (u32 j = 0; j < test->exp_num; j++)
+                       __set_bit(test->exp_bits[j], exp);
+
+               ip_tunnel_flags_from_be16(out, test->exp_val);
+
+               expect_eq_uint(test->exp_comp,
+                              ip_tunnel_flags_is_be16_compat(src));
+               expect_eq_uint((__force u16)test->exp_val,
+                              (__force u16)ip_tunnel_flags_to_be16(src));
+
+               __ipt_flag_op(expect_eq_bitmap, exp, out);
+       }
+}
+
 static void __init selftest(void)
 {
        test_zero_clear();
@@ -1405,6 +1509,7 @@ static void __init selftest(void)
        test_bitmap_read_write();
        test_bitmap_read_perf();
        test_bitmap_write_perf();
+       test_ip_tunnel_flags();
 
        test_find_nth_bit();
        test_for_each_set_bit();
-- 
2.41.0


Reply via email to