api: improve api string safety

- Remove vl_api_from_api_string
  to prevent use of not nul-terminated strings.
- Rename vl_api_from_api_to_vec -> vl_api_from_api_to_new_vec
  to imply a new vector is created. NOT nul terminated.
- Add vl_api_from_api_to_new_c_string. Returns
  nul terminated string in a new vector.
- Add vl_api_c_string_to_api_string. Convert nul terminated
  string to vl_api_string_t
- Add vl_api_vec_to_api_string. Convert NON nul terminated
  vector to vl_api_string_t

Type: fix

Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>
Change-Id: Iadd59b612c0d960a34ad0dd07a9d17f56435c6ea
Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/test/ext/vapi_c_test.c b/test/ext/vapi_c_test.c
index a9572ae8716..51fc572746f 100644
--- a/test/ext/vapi_c_test.c
+++ b/test/ext/vapi_c_test.c
@@ -29,6 +29,9 @@
 #include <vapi/l2.api.vapi.h>
 #include <fake.api.vapi.h>
 
+#include <vppinfra/vec.h>
+#include <vppinfra/mem.h>
+
 DEFINE_VAPI_MSG_IDS_VPE_API_JSON;
 DEFINE_VAPI_MSG_IDS_INTERFACE_API_JSON;
 DEFINE_VAPI_MSG_IDS_L2_API_JSON;
@@ -911,6 +914,66 @@ START_TEST (test_unsupported)
 
 END_TEST;
 
+START_TEST (test_api_strings)
+{
+  printf ("--- Invalid api strings ---\n");
+
+  /* test string 'TEST'
+   * size = 5
+   * length = 4
+   */
+  const char str[] = "TEST";
+  u8 *vec_str = 0, *vstr = 0;
+  char *cstr;
+
+  vapi_msg_sw_interface_dump *dump =
+    malloc (sizeof (vapi_msg_sw_interface_dump) + strlen (str));
+  clib_mem_init (0, 1 << 20);
+
+  vl_api_c_string_to_api_string (str, &dump->payload.name_filter);
+  /* Assert nul terminator NOT present */
+  ck_assert_int_eq (vl_api_string_len (&dump->payload.name_filter),
+		    strlen (str));
+
+  cstr = vl_api_from_api_to_new_c_string (&dump->payload.name_filter);
+  ck_assert_ptr_ne (cstr, NULL);
+  /* Assert nul terminator present */
+  ck_assert_int_eq (vec_len (cstr), sizeof (str));
+  ck_assert_int_eq (strlen (str), strlen (cstr));
+  vec_free (cstr);
+
+  vstr = vl_api_from_api_to_new_vec (&dump->payload.name_filter);
+  ck_assert_ptr_ne (vstr, NULL);
+  /* Assert nul terminator NOT present */
+  ck_assert_int_eq (vec_len (vstr), strlen (str));
+  vec_free (vstr);
+
+  /* vector conaining NON nul terminated string 'TEST' */
+  vec_add (vec_str, str, strlen (str));
+  clib_memset (dump->payload.name_filter.buf, 0, strlen (str));
+  dump->payload.name_filter.length = 0;
+
+  vl_api_vec_to_api_string (vec_str, &dump->payload.name_filter);
+  /* Assert nul terminator NOT present */
+  ck_assert_int_eq (vl_api_string_len (&dump->payload.name_filter),
+		    vec_len (vec_str));
+
+  cstr = vl_api_from_api_to_new_c_string (&dump->payload.name_filter);
+  ck_assert_ptr_ne (cstr, NULL);
+  /* Assert nul terminator present */
+  ck_assert_int_eq (vec_len (cstr), sizeof (str));
+  ck_assert_int_eq (strlen (str), strlen (cstr));
+  vec_free (cstr);
+
+  vstr = vl_api_from_api_to_new_vec (&dump->payload.name_filter);
+  ck_assert_ptr_ne (vstr, NULL);
+  /* Assert nul terminator NOT present */
+  ck_assert_int_eq (vec_len (vstr), strlen (str));
+  vec_free (vstr);
+}
+
+END_TEST;
+
 Suite *
 test_suite (void)
 {
@@ -957,6 +1020,10 @@ test_suite (void)
   tcase_add_test (tc_unsupported, test_unsupported);
   suite_add_tcase (s, tc_unsupported);
 
+  TCase *tc_dynamic = tcase_create ("Dynamic message size");
+  tcase_add_test (tc_dynamic, test_api_strings);
+  suite_add_tcase (s, tc_dynamic);
+
   return s;
 }