api: API trace improvements

Type: improvement

 * add support for JSON format in API trace
 * add ability to replay JSON API trace in both VPP and VAT2
 * use CRC for backward compatibility check during JSON API replay
 * fix API trace CLI (and remove duplicits)
 * remove custom dump
 * remove vppapitrace.py
 * update docs accordingly

Change-Id: I5294f68bebe6cbe738630f457f3a87720e06486b
Signed-off-by: Filip Tehlar <ftehlar@cisco.com>
Signed-off-by: Ole Troan <ot@cisco.com>

5 files changed, 61 insertions, 648 deletions

diff --git a/src/vat2/CMakeLists.txt b/src/vat2/CMakeLists.txt
index 9ee2d8211eb..c44d2452ea1 100644
--- a/src/vat2/CMakeLists.txt
+++ b/src/vat2/CMakeLists.txt
@@ -18,7 +18,6 @@ add_vpp_executable(vat2 ENABLE_EXPORTS
   SOURCES
   main.c
   plugin.c
-  jsonconvert.c
 
   DEPENDS api_headers
 
@@ -41,7 +40,6 @@ vpp_generate_api_c_header (test/vat2_test.api)
 add_vpp_executable(test_vat2 ENABLE_EXPORTS NO_INSTALL
   SOURCES
   test/vat2_test.c
-  jsonconvert.c
 
   DEPENDS api_headers
 
@@ -57,7 +55,6 @@ add_vpp_executable(test_vat2 ENABLE_EXPORTS NO_INSTALL
 
 if("${CMAKE_VERSION}" VERSION_GREATER_EQUAL "3.13" AND "${CMAKE_C_COMPILER_ID}" MATCHES "(Apple)?[Cc]lang")
   set(TARGET_NAME test_vat2)
-  set(COV_SOURCES ${CMAKE_SOURCE_DIR}/vat2/jsonconvert.c)
 
   message("Building with llvm Code Coverage Tools ${TARGET_NAME}")
   target_compile_options(${TARGET_NAME} PRIVATE -fprofile-instr-generate -fcoverage-mapping)
@@ -96,7 +93,6 @@ endif()
 ##############################################################################
 install(
   FILES
-  jsonconvert.h
   vat2_helpers.h
   DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/vat2
   COMPONENT vpp-dev
diff --git a/src/vat2/jsonconvert.c b/src/vat2/jsonconvert.c
deleted file mode 100644
index 1437b90688a..00000000000
--- a/src/vat2/jsonconvert.c
+++ /dev/null
@@ -1,531 +0,0 @@
-/*
- * Copyright (c) 2020 Cisco and/or its affiliates.
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include <vppinfra/cJSON.h>
-#include <vnet/ethernet/mac_address.h>
-#include <vnet/ip/ip6_packet.h>
-#include <vnet/ip/ip_format_fns.h>
-#include <vpp/api/types.h>
-#include "jsonconvert.h"
-
-#define _(T)                                    \
-int vl_api_ ##T## _fromjson(cJSON *o, T *d)     \
-{                                               \
-    if (!cJSON_IsNumber(o)) return -1;          \
-    memcpy(d, &o->valueint, sizeof(T));         \
-    return 0;                                   \
-}
-  foreach_vat2_fromjson
-#undef _
-
-int vl_api_bool_fromjson(cJSON *o, bool *d)
-{
-    if (!cJSON_IsBool(o)) return -1;
-    *d = o->valueint ? true : false;
-    return 0;
-}
-
-int vl_api_u8_string_fromjson(cJSON *o, u8 *s, int len)
-{
-    unformat_input_t input;
-    char *p = cJSON_GetStringValue(o);
-    unformat_init_string (&input, p, strlen(p));
-    if (!unformat (&input, "0x%U", unformat_hex_string, s))
-      return -1;
-    return 0;
-}
-
-u8 *
-u8string_fromjson(cJSON *o, char *fieldname)
-{
-    u8 *s = 0;
-    unformat_input_t input;
-    cJSON *item = cJSON_GetObjectItem(o, fieldname);
-    if (!item) {
-        printf("Illegal JSON, no such fieldname %s\n", fieldname);
-        return 0;
-    }
-
-    char *p = cJSON_GetStringValue(item);
-    unformat_init_string (&input, p, strlen(p));
-    if (!unformat (&input, "0x%U", unformat_hex_string, &s))
-      return 0;
-    return s;
-}
-
-int
-u8string_fromjson2(cJSON *o, char *fieldname, u8 *data)
-{
-    u8 *s = u8string_fromjson(o, fieldname);
-    if (!s)
-      return -1;
-    memcpy(data, s, vec_len(s));
-    vec_free(s);
-    return 0;
-}
-
-/* Parse an IP4 address %d.%d.%d.%d. */
-uword
-unformat_ip4_address (unformat_input_t * input, va_list * args)
-{
-  u8 *result = va_arg (*args, u8 *);
-  unsigned a[4];
-
-  if (!unformat (input, "%d.%d.%d.%d", &a[0], &a[1], &a[2], &a[3]))
-    return 0;
-
-  if (a[0] >= 256 || a[1] >= 256 || a[2] >= 256 || a[3] >= 256)
-    return 0;
-
-  result[0] = a[0];
-  result[1] = a[1];
-  result[2] = a[2];
-  result[3] = a[3];
-
-  return 1;
-}
-
-/* Parse an IP6 address. */
-uword
-unformat_ip6_address (unformat_input_t * input, va_list * args)
-{
-  ip6_address_t *result = va_arg (*args, ip6_address_t *);
-  u16 hex_quads[8];
-  uword hex_quad, n_hex_quads, hex_digit, n_hex_digits;
-  uword c, n_colon, double_colon_index;
-
-  n_hex_quads = hex_quad = n_hex_digits = n_colon = 0;
-  double_colon_index = ARRAY_LEN (hex_quads);
-  while ((c = unformat_get_input (input)) != UNFORMAT_END_OF_INPUT)
-    {
-      hex_digit = 16;
-      if (c >= '0' && c <= '9')
-        hex_digit = c - '0';
-      else if (c >= 'a' && c <= 'f')
-        hex_digit = c + 10 - 'a';
-      else if (c >= 'A' && c <= 'F')
-        hex_digit = c + 10 - 'A';
-      else if (c == ':' && n_colon < 2)
-        n_colon++;
-      else
-        {
-          unformat_put_input (input);
-          break;
-        }
-
-      /* Too many hex quads. */
-      if (n_hex_quads >= ARRAY_LEN (hex_quads))
-        return 0;
-
-      if (hex_digit < 16)
-        {
-          hex_quad = (hex_quad << 4) | hex_digit;
-
-          /* Hex quad must fit in 16 bits. */
-          if (n_hex_digits >= 4)
-            return 0;
-
-          n_colon = 0;
-          n_hex_digits++;
-        }
-
-      /* Save position of :: */
-      if (n_colon == 2)
-        {
-          /* More than one :: ? */
-          if (double_colon_index < ARRAY_LEN (hex_quads))
-            return 0;
-          double_colon_index = n_hex_quads;
-        }
-
-      if (n_colon > 0 && n_hex_digits > 0)
-        {
-          hex_quads[n_hex_quads++] = hex_quad;
-          hex_quad = 0;
-          n_hex_digits = 0;
-        }
-    }
-
-  if (n_hex_digits > 0)
-    hex_quads[n_hex_quads++] = hex_quad;
-
-
-  {
-    word i;
-
-    /* Expand :: to appropriate number of zero hex quads. */
-    if (double_colon_index < ARRAY_LEN (hex_quads))
-      {
-        word n_zero = ARRAY_LEN (hex_quads) - n_hex_quads;
-
-        for (i = n_hex_quads - 1; i >= (signed) double_colon_index; i--)
-          hex_quads[n_zero + i] = hex_quads[i];
-
-        for (i = 0; i < n_zero; i++)
-          {
-            ASSERT ((double_colon_index + i) < ARRAY_LEN (hex_quads));
-            hex_quads[double_colon_index + i] = 0;
-          }
-
-        n_hex_quads = ARRAY_LEN (hex_quads);
-      }
-
-    /* Too few hex quads given. */
-    if (n_hex_quads < ARRAY_LEN (hex_quads))
-      return 0;
-
-    for (i = 0; i < ARRAY_LEN (hex_quads); i++)
-      result->as_u16[i] = clib_host_to_net_u16 (hex_quads[i]);
-
-    return 1;
-  }
-}
-
-u8 *
-format_ip6_address (u8 * s, va_list * args)
-{
-  ip6_address_t *a = va_arg (*args, ip6_address_t *);
-  u32 max_zero_run = 0, this_zero_run = 0;
-  int max_zero_run_index = -1, this_zero_run_index = 0;
-  int in_zero_run = 0, i;
-  int last_double_colon = 0;
-
-  /* Ugh, this is a pain. Scan forward looking for runs of 0's */
-  for (i = 0; i < ARRAY_LEN (a->as_u16); i++)
-    {
-      if (a->as_u16[i] == 0)
-        {
-          if (in_zero_run)
-            this_zero_run++;
-          else
-            {
-              in_zero_run = 1;
-              this_zero_run = 1;
-              this_zero_run_index = i;
-            }
-        }
-      else
-        {
-          if (in_zero_run)
-            {
-              /* offer to compress the biggest run of > 1 zero */
-              if (this_zero_run > max_zero_run && this_zero_run > 1)
-                {
-                  max_zero_run_index = this_zero_run_index;
-                  max_zero_run = this_zero_run;
-                }
-            }
-          in_zero_run = 0;
-          this_zero_run = 0;
-        }
-    }
-
-  if (in_zero_run)
-    {
-      if (this_zero_run > max_zero_run && this_zero_run > 1)
-        {
-          max_zero_run_index = this_zero_run_index;
-          max_zero_run = this_zero_run;
-        }
-    }
-
-  for (i = 0; i < ARRAY_LEN (a->as_u16); i++)
-    {
-      if (i == max_zero_run_index)
-        {
-          s = format (s, "::");
-          i += max_zero_run - 1;
-          last_double_colon = 1;
-        }
-      else
-        {
-          s = format (s, "%s%x",
-                      (last_double_colon || i == 0) ? "" : ":",
-                      clib_net_to_host_u16 (a->as_u16[i]));
-          last_double_colon = 0;
-        }
-    }
-
-  return s;
-}
-
-int
-vl_api_ip4_address_t_fromjson (void **mp, int *len, cJSON *o,
-			       vl_api_ip4_address_t *a)
-{
-    unformat_input_t input;
-    char *p = cJSON_GetStringValue(o);
-    if (!p)
-      return -1;
-    unformat_init_string (&input, p, strlen(p));
-    if (!unformat (&input, "%U", unformat_ip4_address, a))
-      return -1;
-    return 0;
-}
-
-int
-vl_api_ip4_prefix_t_fromjson (void **mp, int *len, cJSON *o,
-			      vl_api_ip4_prefix_t *a)
-{
-    unformat_input_t input;
-    char *p = cJSON_GetStringValue(o);
-    if (!p)
-      return -1;
-    unformat_init_string (&input, p, strlen(p));
-    if (!unformat (&input, "%U/%d", unformat_ip4_address, &a->address,
-		   &a->len))
-      return -1;
-    return 0;
-}
-
-int
-vl_api_ip4_address_with_prefix_t_fromjson (void **mp, int *len, cJSON *o,
-					   vl_api_ip4_prefix_t *a)
-{
-  return vl_api_ip4_prefix_t_fromjson(mp, len, o, a);
-}
-int
-vl_api_ip6_address_t_fromjson (void **mp, int *len, cJSON *o,
-			       vl_api_ip6_address_t *a)
-{
-    unformat_input_t input;
-    char *p = cJSON_GetStringValue(o);
-    if (!p)
-      return -1;
-    unformat_init_string (&input, p, strlen(p));
-    if (!unformat (&input, "%U", unformat_ip6_address, a))
-      return -1;
-    return 0;
-}
-
-int
-vl_api_ip6_prefix_t_fromjson (void **mp, int *len, cJSON *o,
-			      vl_api_ip6_prefix_t *a)
-{
-  unformat_input_t input;
-  char *p = cJSON_GetStringValue(o);
-  if (!p)
-    return -1;
-  unformat_init_string (&input, p, strlen(p));
-  if (!unformat (&input, "%U/%d", unformat_ip6_address, &a->address, &a->len))
-    return -1;
-  return 0;
-}
-
-int
-vl_api_ip6_address_with_prefix_t_fromjson (void **mp, int *len, cJSON *o,
-					   vl_api_ip6_prefix_t *a)
-{
-  return vl_api_ip6_prefix_t_fromjson(mp, len, o, a);
-}
-
-int
-vl_api_address_t_fromjson (void **mp, int *len, cJSON *o, vl_api_address_t *a)
-{
-  unformat_input_t input;
-
-  char *p = cJSON_GetStringValue(o);
-  if (!p)
-    return -1;
-  unformat_init_string (&input, p, strlen(p));
-  if (unformat (&input, "%U", unformat_ip4_address, &a->un.ip4))
-    a->af = ADDRESS_IP4;
-  else if (unformat (&input, "%U", unformat_ip6_address, &a->un.ip6))
-    a->af = ADDRESS_IP6;
-  else
-    return -1;
-  return 0;
-}
-
-int
-vl_api_prefix_t_fromjson (void **mp, int *len, cJSON *o, vl_api_prefix_t *a)
-{
-  unformat_input_t input;
-
-  char *p = cJSON_GetStringValue(o);
-
-  if (!p)
-    return -1;
-  unformat_init_string (&input, p, strlen(p));
-  int plen;
-  if (unformat (&input, "%U/%d", unformat_ip4_address, &a->address.un.ip4, &plen))
-    a->address.af = ADDRESS_IP4;
-  else if (unformat (&input, "%U/%d", unformat_ip6_address, &a->address.un.ip6, &plen))
-    a->address.af = ADDRESS_IP6;
-  else
-    return -1;
-  a->len = plen;
-  return 0;
-}
-
-int
-vl_api_address_with_prefix_t_fromjson (void **mp, int *len, cJSON *o,
-				       vl_api_prefix_t *a)
-{
-  return vl_api_prefix_t_fromjson(mp, len, o, a);
-}
-
-uword
-unformat_mac_address (unformat_input_t * input, va_list * args)
-{
-  mac_address_t *mac = va_arg (*args, mac_address_t *);
-  u32 i, a[3];
-
-  if (unformat (input, "%_%X:%X:%X:%X:%X:%X%_",
-                1, &mac->bytes[0], 1, &mac->bytes[1], 1, &mac->bytes[2],
-                1, &mac->bytes[3], 1, &mac->bytes[4], 1, &mac->bytes[5]))
-    return (1);
-  else if (unformat (input, "%_%x.%x.%x%_", &a[0], &a[1], &a[2]))
-    {
-      for (i = 0; i < ARRAY_LEN (a); i++)
-        if (a[i] >= (1 << 16))
-          return 0;
-
-      mac->bytes[0] = (a[0] >> 8) & 0xff;
-      mac->bytes[1] = (a[0] >> 0) & 0xff;
-      mac->bytes[2] = (a[1] >> 8) & 0xff;
-      mac->bytes[3] = (a[1] >> 0) & 0xff;
-      mac->bytes[4] = (a[2] >> 8) & 0xff;
-      mac->bytes[5] = (a[2] >> 0) & 0xff;
-
-      return (1);
-    }
-  return (0);
-}
-
-int
-vl_api_mac_address_t_fromjson (void **mp, int *len, cJSON *o,
-			       vl_api_mac_address_t *a)
-{
-  unformat_input_t input;
-
-  char *p = cJSON_GetStringValue(o);
-  unformat_init_string (&input, p, strlen(p));
-  if (!unformat (&input, "%U", unformat_mac_address, a))
-    return -1;
-  return 0;
-}
-
-/* Format an IP4 address. */
-u8 *
-format_ip4_address (u8 * s, va_list * args)
-{
-  u8 *a = va_arg (*args, u8 *);
-  return format (s, "%d.%d.%d.%d", a[0], a[1], a[2], a[3]);
-}
-
-int
-vl_api_c_string_to_api_string (const char *buf, vl_api_string_t * str)
-{
-  /* copy without nul terminator */
-  u32 len = strlen (buf);
-  if (len > 0)
-    clib_memcpy_fast (str->buf, buf, len);
-  str->length = htonl (len);
-  return len + sizeof (u32);
-}
-
-u8 *
-format_vl_api_interface_index_t (u8 *s, va_list *args)
-{
-  u32 *a = va_arg (*args, u32 *);
-  return format (s, "%u", *a);
-}
-
-void
-vl_api_string_cJSON_AddToObject(cJSON * const object, const char * const name, vl_api_string_t *astr)
-{
-
-    if (astr == 0) return;
-    u32 length = clib_net_to_host_u32 (astr->length);
-
-    char *cstr = malloc(length + 1);
-    memcpy(cstr, astr->buf, length);
-    cstr[length] = '\0';
-    cJSON_AddStringToObject(object, name, cstr);
-    free(cstr);
-}
-
-u8 *
-format_vl_api_timestamp_t(u8 * s, va_list * args)
-{
-    f64 timestamp = va_arg (*args, f64);
-    struct tm *tm;
-    word msec;
-
-    time_t t = timestamp;
-    tm = gmtime (&t);
-    msec = 1e6 * (timestamp - t);
-    return format (s, "%4d-%02d-%02dT%02d:%02d:%02d.%06dZ", 1900 + tm->tm_year,
-                   1 + tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min,
-                   tm->tm_sec, msec);
-}
-
-u8 *
-format_vl_api_timedelta_t(u8 * s, va_list * args)
-{
-    return format_vl_api_timestamp_t(s, args);
-}
-
-uword
-unformat_vl_api_timedelta_t(unformat_input_t * input, va_list * args)
-{
-    return 0;
-}
-
-uword
-unformat_vl_api_timestamp_t(unformat_input_t * input, va_list * args)
-{
-    return 0;
-}
-u8 *format_vl_api_gbp_scope_t(u8 * s, va_list * args)
-{
-    return 0;
-}
-uword unformat_vl_api_gbp_scope_t(unformat_input_t * input, va_list * args)
-{
-    return 0;
-}
-
-cJSON *
-vl_api_ip4_address_with_prefix_t_tojson (vl_api_ip4_prefix_t *a) {
-  return vl_api_ip4_prefix_t_tojson (a);
-}
-cJSON *
-vl_api_ip6_address_with_prefix_t_tojson (vl_api_ip6_prefix_t *a) {
-  return vl_api_ip6_prefix_t_tojson (a);
-}
-cJSON *
-vl_api_address_with_prefix_t_tojson (vl_api_prefix_t *a) {
-  return vl_api_prefix_t_tojson (a);
-}
-u8 *
-format_vl_api_mac_address_t (u8 * s, va_list * args)
-{
-  const mac_address_t *mac = va_arg (*args, mac_address_t *);
-
-  return format (s, "%02x:%02x:%02x:%02x:%02x:%02x",
-                 mac->bytes[0], mac->bytes[1], mac->bytes[2],
-                 mac->bytes[3], mac->bytes[4], mac->bytes[5]);
-}
-#define _(T)                                                \
-  cJSON *vl_api_ ##T## _t_tojson (vl_api_ ##T## _t *a) {   \
-  u8 *s = format(0, "%U", format_vl_api_ ##T## _t, a);      \
-  cJSON *o = cJSON_CreateString((char *)s);                 \
-  vec_free(s);                                              \
-  return o;                                                 \
-  }
-foreach_vat2_tojson
-#undef _
diff --git a/src/vat2/jsonconvert.h b/src/vat2/jsonconvert.h
deleted file mode 100644
index 038ad74ac0e..00000000000
--- a/src/vat2/jsonconvert.h
+++ /dev/null
@@ -1,105 +0,0 @@
-/*
- * Copyright (c) 2020 Cisco and/or its affiliates.
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef included_json_convert_h
-#define included_json_convert_h
-
-#include <stdbool.h>
-#include <vppinfra/cJSON.h>
-#include <vnet/ethernet/mac_address.h>
-#include <vnet/ip/ip6_packet.h>
-#include <vnet/ip/ip_types.api_types.h>
-#include <vnet/ethernet/ethernet_types.api_types.h>
-
-#define foreach_vat2_fromjson                   \
-  _(i8)                                         \
-  _(u8)                                         \
-  _(i16)                                        \
-  _(u16)                                        \
-  _(i32)                                        \
-  _(u32)                                        \
-  _(u64)                                        \
-  _(f64)
-
-#define _(T)                                    \
-  int vl_api_ ##T## _fromjson(cJSON *o, T *d);
-foreach_vat2_fromjson
-#undef _
-
-  /* Prototypes */
-  int
-  vl_api_bool_fromjson (cJSON *o, bool *d);
-int vl_api_ip4_address_t_fromjson (void **mp, int *len, cJSON *o,
-				   vl_api_ip4_address_t *a);
-int vl_api_ip4_prefix_t_fromjson (void **mp, int *len, cJSON *o,
-				  vl_api_ip4_prefix_t *a);
-int vl_api_ip4_address_with_prefix_t_fromjson (void **mp, int *len, cJSON *o,
-					       vl_api_ip4_prefix_t *a);
-int vl_api_ip6_address_t_fromjson (void **mp, int *len, cJSON *o,
-				   vl_api_ip6_address_t *a);
-int vl_api_ip6_prefix_t_fromjson (void **mp, int *len, cJSON *o,
-				  vl_api_ip6_prefix_t *a);
-int vl_api_ip6_address_with_prefix_t_fromjson (void **mp, int *len, cJSON *o,
-					       vl_api_ip6_prefix_t *a);
-int vl_api_address_t_fromjson (void **mp, int *len, cJSON *o,
-			       vl_api_address_t *a);
-int vl_api_prefix_t_fromjson (void **mp, int *len, cJSON *o,
-			      vl_api_prefix_t *a);
-int vl_api_address_with_prefix_t_fromjson (void **mp, int *len, cJSON *o,
-					   vl_api_prefix_t *a);
-int vl_api_mac_address_t_fromjson (void **mp, int *len, cJSON *o,
-				   vl_api_mac_address_t *a);
-
-uword unformat_ip4_address (unformat_input_t *input, va_list *args);
-uword unformat_ip6_address (unformat_input_t *input, va_list *args);
-u8 *format_ip6_address (u8 *s, va_list *args);
-uword unformat_mac_address (unformat_input_t *input, va_list *args);
-u8 *format_ip4_address (u8 *s, va_list *args);
-u8 *format_vl_api_interface_index_t (u8 *s, va_list *args);
-u8 *format_vl_api_timestamp_t (u8 *s, va_list *args);
-u8 *format_vl_api_timedelta_t (u8 *s, va_list *args);
-uword unformat_vl_api_timedelta_t (unformat_input_t *input, va_list *args);
-uword unformat_vl_api_timestamp_t (unformat_input_t *input, va_list *args);
-u8 *format_vl_api_gbp_scope_t (u8 *s, va_list *args);
-uword unformat_vl_api_gbp_scope_t (unformat_input_t *input, va_list *args);
-
-int vl_api_c_string_to_api_string (const char *buf, vl_api_string_t *str);
-void vl_api_string_cJSON_AddToObject (cJSON *const object,
-				      const char *const name,
-				      vl_api_string_t *astr);
-
-u8 *u8string_fromjson (cJSON *o, char *fieldname);
-int u8string_fromjson2 (cJSON *o, char *fieldname, u8 *data);
-int vl_api_u8_string_fromjson (cJSON *o, u8 *s, int len);
-
-#define foreach_vat2_tojson                     \
-  _(ip4_address)                                \
-  _(ip4_prefix)                                 \
-  _(ip6_address)                                \
-  _(ip6_prefix)                                 \
-  _(address)                                    \
-  _(prefix)                                     \
-  _(mac_address)
-
-#define _(T)                                    \
-  cJSON *vl_api_ ##T## _t_tojson(vl_api_ ##T## _t *);
-  foreach_vat2_tojson
-#undef _
-
-cJSON *vl_api_ip4_address_with_prefix_t_tojson (vl_api_ip4_prefix_t *a);
-cJSON *vl_api_ip6_address_with_prefix_t_tojson (vl_api_ip6_prefix_t *a);
-cJSON *vl_api_address_with_prefix_t_tojson (vl_api_prefix_t *a);
-
-#endif
diff --git a/src/vat2/main.c b/src/vat2/main.c
index 208e0c5d2c2..667f473c635 100644
--- a/src/vat2/main.c
+++ b/src/vat2/main.c
@@ -18,7 +18,7 @@
 #include <stdbool.h>
 #include <ctype.h>
 #include <getopt.h>
-#include <assert.h>
+#include <string.h>
 #include <vlib/vlib.h>
 #include <vlibapi/api_types.h>
 #include <vppinfra/hash.h>
@@ -30,6 +30,33 @@
 #include <limits.h>
 #include "vat2.h"
 
+/*
+ * Filter these messages as they are used to manage the API connection to VPP
+ */
+char *filter_messages_strings[] = { "memclnt_create",
+				    "memclnt_delete",
+				    "sockclnt_create",
+				    "sockclnt_delete",
+				    "memclnt_rx_thread_suspend",
+				    "memclnt_read_timeout",
+				    "rx_thread_exit",
+				    "trace_plugin_msg_ids",
+				    0 };
+
+static bool
+filter_message (char *msgname)
+{
+  char **p = filter_messages_strings;
+
+  while (*p)
+    {
+      if (strcmp (*p, msgname) == 0)
+	return true;
+      p++;
+    }
+  return false;
+}
+
 uword *function_by_name;
 bool debug = false;
 
@@ -89,15 +116,16 @@ struct apifuncs_s
 {
   cJSON (*f) (cJSON *);
   cJSON (*tojson) (void *);
+  u32 crc;
 };
 
 struct apifuncs_s *apifuncs = 0;
 
 void
 vat2_register_function (char *name, cJSON (*f) (cJSON *),
-			cJSON (*tojson) (void *))
+			cJSON (*tojson) (void *), u32 crc)
 {
-  struct apifuncs_s funcs = { .f = f, .tojson = tojson };
+  struct apifuncs_s funcs = { .f = f, .tojson = tojson, .crc = crc };
   vec_add1 (apifuncs, funcs);
   hash_set_mem (function_by_name, name, vec_len (apifuncs) - 1);
 }
@@ -105,12 +133,28 @@ vat2_register_function (char *name, cJSON (*f) (cJSON *),
 static int
 vat2_exec_command_by_name (char *msgname, cJSON *o)
 {
+  if (filter_message (msgname))
+    return 0;
+
+  cJSON *crc_obj = cJSON_GetObjectItem (o, "_crc");
+  if (!crc_obj)
+    {
+      fprintf (stderr, "Missing '_crc' element!\n");
+      return -1;
+    }
+  char *crc_str = cJSON_GetStringValue (crc_obj);
+  u32 crc = (u32) strtol (crc_str, NULL, 16);
+
   uword *p = hash_get_mem (function_by_name, msgname);
   if (!p)
     {
-      fprintf (stderr, "No such command %s", msgname);
+      fprintf (stderr, "No such command %s\n", msgname);
       return -1;
     }
+  if (crc != apifuncs[p[0]].crc)
+    {
+      fprintf (stderr, "API CRC does not match: %s!\n", msgname);
+    }
 
   cJSON *(*fp) (cJSON *);
   fp = (void *) apifuncs[p[0]].f;
@@ -143,9 +187,10 @@ vat2_exec_command (cJSON *o)
     }
 
   char *name = cJSON_GetStringValue (msg_id_obj);
-  assert (name);
+
   return vat2_exec_command_by_name (name, o);
 }
+
 static void
 print_template (char *msgname)
 {
@@ -307,6 +352,12 @@ int main (int argc, char **argv)
     }
   }
 
+  if (!msgname && !filename)
+    {
+      print_help ();
+      exit (-1);
+    }
+
   /* Read message from file */
   if (filename) {
       if (argc > index)
@@ -325,6 +376,7 @@ int main (int argc, char **argv)
       fprintf(stderr, "%s: can't open file: %s\n", argv[0], filename);
       exit(-1);
     }
+
     chunksize = bufsize = 1024;
     char *buf = malloc(bufsize);
     while ((n = fread (buf + n_read, 1, chunksize, f)))
@@ -339,17 +391,17 @@ int main (int argc, char **argv)
     fclose(f);
     if (n_read) {
       o = cJSON_Parse(buf);
-      free(buf);
       if (!o) {
         fprintf(stderr, "%s: Failed parsing JSON input: %s\n", argv[0], cJSON_GetErrorPtr());
         exit(-1);
       }
     }
+    free (buf);
   }
 
-  if (!msgname && !filename)
+  if (!o)
     {
-      print_help ();
+      fprintf (stderr, "%s: Failed parsing JSON input\n", argv[0]);
       exit (-1);
     }
 
diff --git a/src/vat2/test/vat2_test.c b/src/vat2/test/vat2_test.c
index 1ac46527b3c..7aa5e71296e 100644
--- a/src/vat2/test/vat2_test.c
+++ b/src/vat2/test/vat2_test.c
@@ -196,6 +196,7 @@ struct tests tests[] = {
 	 "[\"2001:db8::23\", \"2001:db8::23\"] }" },
   { .s = "{\"_msgname\": \"test_empty\"}" },
   { .s = "{\"_msgname\": \"test_interface\", \"sw_if_index\": 100 }" },
+  { .s = "{\"_msgname\": \"test_interface\", \"sw_if_index\": 4294967295 }" },
 };
 
 int main (int argc, char **argv)