api: vat2 and json autogeneration for api messages
[vpp.git] / src / tools / vppapigen / vppapigen_c.py
index a879074..4369dd8 100644 (file)
@@ -1,4 +1,28 @@
-# C generation
+#
+# 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.
+#
+
+#
+# Provide two classes FromJSON and TOJSON that converts between JSON and VPP's
+# binary API format
+#
+
+'''
+This module creates C code for core VPP, VPP plugins and client side VAT and
+VAT2 tests.
+'''
+
 import datetime
 import os
 import time
@@ -8,10 +32,588 @@ import shutil
 
 process_imports = False
 
-datestring = datetime.datetime.utcfromtimestamp(
+###############################################################################
+class ToJSON():
+    '''Class to generate functions converting from VPP binary API to JSON.'''
+    _dispatch = {}
+    noprint_fields = {'_vl_msg_id': None,
+                      'client_index': None,
+                      'context': None}
+    is_number = {'u8': None,
+                 'i8': None,
+                 'u16': None,
+                 'i16': None,
+                 'u32': None,
+                 'i32': None,
+                 'u64': None,
+                 'i64': None,
+                 'f64': None,
+                 }
+
+    def __init__(self, module, types, defines, imported_types, stream):
+        self.stream = stream
+        self.module = module
+        self.defines = defines
+        self.types = types
+        self.types_hash = {'vl_api_'+d.name+'_t':
+                           d for d in types + imported_types}
+        self.defines_hash = {d.name: d for d in defines}
+
+    def header(self):
+        '''Output the top boilerplate.'''
+        write = self.stream.write
+        write('#ifndef included_{}_api_tojson_h\n'.format(self.module))
+        write('#define included_{}_api_tojson_h\n'.format(self.module))
+        write('#include <vppinfra/cJSON.h>\n\n')
+        write('#include <vat2/jsonconvert.h>\n\n')
+
+    def footer(self):
+        '''Output the bottom boilerplate.'''
+        write = self.stream.write
+        write('#endif\n')
+
+    def get_json_func(self, t):
+        '''Given the type, returns the function to use to create a
+        cJSON object'''
+        vt_type = None
+        try:
+            vt = self.types_hash[t]
+            if vt.type == 'Using' and 'length' not in vt.alias:
+                vt_type = vt.alias['type']
+        except KeyError:
+            vt = t
+
+        if t in self.is_number or vt_type in self.is_number:
+            return 'cJSON_AddNumberToObject', '', False
+        if t == 'bool':
+            return 'cJSON_AddBoolToObject', '', False
+
+        # Lookup type name check if it's enum
+        if vt.type == 'Enum':
+            return '{t}_tojson'.format(t=t), '', True
+        return '{t}_tojson'.format(t=t), '&', True
+
+    def get_json_array_func(self, t):
+        '''Given a type returns the function to create a cJSON object
+        for arrays.'''
+        if t in self.is_number:
+            return 'cJSON_CreateNumber', ''
+        if t == 'bool':
+            return 'cJSON_CreateBool', ''
+        return '{t}_tojson'.format(t=t), '&'
+
+    def print_string(self, o):
+        '''Create cJSON object from vl_api_string_t'''
+        write = self.stream.write
+        if o.modern_vla:
+            write('    vl_api_string_cJSON_AddToObject(o, "{n}", &a->{n});\n'
+                  .format(n=o.fieldname))
+        else:
+
+            write('    cJSON_AddStringToObject(o, "{n}", (char *)a->{n});\n'
+                  .format(n=o.fieldname))
+
+    def print_field(self, o):
+        '''Called for every field in a typedef or define.'''
+        write = self.stream.write
+        if o.fieldname in self.noprint_fields:
+            return
+
+        f, p, newobj = self.get_json_func(o.fieldtype)
+
+        if newobj:
+            write('    cJSON_AddItemToObject(o, "{n}", {f}({p}a->{n}));\n'
+                  .format(f=f, p=p, n=o.fieldname))
+        else:
+            write('    {f}(o, "{n}", {p}a->{n});\n'
+                  .format(f=f, p=p, n=o.fieldname))
+
+    _dispatch['Field'] = print_field
+
+    def print_array(self, o):
+        '''Converts a VPP API array to cJSON array.'''
+        write = self.stream.write
+
+        forloop = '''\
+    {{
+        int i;
+        cJSON *array = cJSON_AddArrayToObject(o, "{n}");
+        for (i = 0; i < {lfield}; i++) {{
+            cJSON_AddItemToArray(array, {f}({p}a->{n}[i]));
+        }}
+    }}
+'''
+
+        if o.fieldtype == 'string':
+            self.print_string(o)
+            return
+
+        lfield = 'a->' + o.lengthfield if o.lengthfield else o.length
+        if o.fieldtype == 'u8':
+            write('    {\n')
+            # What is length field doing here?
+            write('    u8 *s = format(0, "0x%U", format_hex_bytes, '
+                  '&a->{n}, {lfield});\n'
+                  .format(n=o.fieldname, lfield=lfield))
+            write('    cJSON_AddStringToObject(o, "{n}", (char *)s);\n'
+                  .format(n=o.fieldname))
+            write('    vec_free(s);\n')
+            write('    }\n')
+            return
+
+        f, p = self.get_json_array_func(o.fieldtype)
+        write(forloop.format(lfield=lfield,
+                             t=o.fieldtype,
+                             n=o.fieldname,
+                             f=f,
+                             p=p))
+
+    _dispatch['Array'] = print_array
+
+    def print_enum(self, o):
+        '''Create cJSON object (string) for VPP API enum'''
+        write = self.stream.write
+        write('static inline cJSON *vl_api_{name}_t_tojson '
+              '(vl_api_{name}_t a) {{\n'.format(name=o.name))
+
+        write("    switch(a) {\n")
+        for b in o.block:
+            write("    case %s:\n" % b[1])
+            write('        return cJSON_CreateString("{}");\n'.format(b[0]))
+        write('    default: return cJSON_CreateString("Invalid ENUM");\n')
+        write('    }\n')
+        write('    return 0;\n')
+        write('}\n')
+
+    _dispatch['Enum'] = print_enum
+
+    def print_typedef(self, o):
+        '''Create cJSON (dictionary) object from VPP API typedef'''
+        write = self.stream.write
+        write('static inline cJSON *vl_api_{name}_t_tojson '
+              '(vl_api_{name}_t *a) {{\n'.format(name=o.name))
+        write('    cJSON *o = cJSON_CreateObject();\n')
+
+        for t in o.block:
+            self._dispatch[t.type](self, t)
+
+        write('    return o;\n')
+        write('}\n')
+
+    def print_define(self, o):
+        '''Create cJSON (dictionary) object from VPP API define'''
+        write = self.stream.write
+        write('static inline cJSON *vl_api_{name}_t_tojson '
+              '(vl_api_{name}_t *a) {{\n'.format(name=o.name))
+        write('    cJSON *o = cJSON_CreateObject();\n')
+        write('    cJSON_AddStringToObject(o, "_msgname", "{}");\n'
+              .format(o.name))
+
+        for t in o.block:
+            self._dispatch[t.type](self, t)
+
+        write('    return o;\n')
+        write('}\n')
+
+    def print_using(self, o):
+        '''Create cJSON (dictionary) object from VPP API aliased type'''
+        if o.manual_print:
+            return
+
+        write = self.stream.write
+        write('static inline cJSON *vl_api_{name}_t_tojson '
+              '(vl_api_{name}_t *a) {{\n'.format(name=o.name))
+
+        write('    u8 *s = format(0, "%U", format_vl_api_{}_t, a);\n'
+              .format(o.name))
+        write('    cJSON *o = cJSON_CreateString((char *)s);\n')
+        write('    vec_free(s);\n')
+        write('    return o;\n')
+        write('}\n')
+
+    _dispatch['Typedef'] = print_typedef
+    _dispatch['Define'] = print_define
+    _dispatch['Using'] = print_using
+    _dispatch['Union'] = print_typedef
+
+    def generate_function(self, t):
+        '''Main entry point'''
+        write = self.stream.write
+        if t.manual_print:
+            write('/* Manual print {} */\n'.format(t.name))
+            return
+        self._dispatch[t.type](self, t)
+
+    def generate_types(self):
+        '''Main entry point'''
+        for t in self.types:
+            self.generate_function(t)
+
+    def generate_defines(self):
+        '''Main entry point'''
+        for t in self.defines:
+            self.generate_function(t)
+
+
+class FromJSON():
+    '''
+    Parse JSON objects into VPP API binary message structures.
+    '''
+    _dispatch = {}
+    noprint_fields = {'_vl_msg_id': None,
+                      'client_index': None,
+                      'context': None}
+    is_number = {'u8': None,
+                 'i8': None,
+                 'u16': None,
+                 'i16': None,
+                 'u32': None,
+                 'i32': None,
+                 'u64': None,
+                 'i64': None,
+                 'f64': None,
+                 }
+
+    def __init__(self, module, types, defines, imported_types, stream):
+        self.stream = stream
+        self.module = module
+        self.defines = defines
+        self.types = types
+        self.types_hash = {'vl_api_'+d.name+'_t':
+                           d for d in types + imported_types}
+        self.defines_hash = {d.name: d for d in defines}
+
+    def header(self):
+        '''Output the top boilerplate.'''
+        write = self.stream.write
+        write('#ifndef included_{}_api_fromjson_h\n'.format(self.module))
+        write('#define included_{}_api_fromjson_h\n'.format(self.module))
+        write('#include <vppinfra/cJSON.h>\n\n')
+        write('#include <vat2/jsonconvert.h>\n\n')
+
+    def is_base_type(self, t):
+        '''Check if a type is one of the VPP API base types'''
+        if t in self.is_number:
+            return True
+        if t == 'bool':
+            return True
+        return False
+
+    def footer(self):
+        '''Output the bottom boilerplate.'''
+        write = self.stream.write
+        write('#endif\n')
+
+    def print_string(self, o, toplevel=False):
+        '''Convert JSON string to vl_api_string_t'''
+        write = self.stream.write
+
+        msgvar = "a" if toplevel else "mp"
+        msgsize = "l" if toplevel else "*len"
+
+        if o.modern_vla:
+            write('    char *p = cJSON_GetStringValue(item);\n')
+            write('    size_t plen = strlen(p);\n')
+            write('    {msgvar} = realloc({msgvar}, {msgsize} + plen);\n'
+                  .format(msgvar=msgvar, msgsize=msgsize))
+            write('    vl_api_c_string_to_api_string(p, (void *){msgvar} + '
+                  '{msgsize} - sizeof(vl_api_string_t));\n'
+                  .format(msgvar=msgvar, msgsize=msgsize))
+            write('    {msgsize} += plen;\n'.format(msgsize=msgsize))
+        else:
+            write('    strncpy_s((char *)a->{n}, sizeof(a->{n}), '
+                  'cJSON_GetStringValue(item), sizeof(a->{n}) - 1);\n'
+                  .format(n=o.fieldname))
+
+    def print_field(self, o, toplevel=False):
+        '''Called for every field in a typedef or define.'''
+        write = self.stream.write
+        write('    // start field {}\n'.format(o.fieldname))
+        if o.fieldname in self.noprint_fields:
+            return
+        is_bt = self.is_base_type(o.fieldtype)
+        t = 'vl_api_{}'.format(o.fieldtype) if is_bt else o.fieldtype
+
+        msgvar = "a" if toplevel else "mp"
+        msgsize = "&l" if toplevel else "len"
+
+        if is_bt:
+            write('    vl_api_{t}_fromjson(item, &a->{n});\n'
+                  .format(t=o.fieldtype, n=o.fieldname))
+        else:
+            write('    {msgvar} = {t}_fromjson({msgvar}, '
+                  '{msgsize}, item, &a->{n});\n'
+                  .format(t=t, n=o.fieldname, msgvar=msgvar, msgsize=msgsize))
+            write('    if (!{msgvar}) return 0;\n'.format(msgvar=msgvar))
+
+        write('    // end field {}\n'.format(o.fieldname))
+
+    _dispatch['Field'] = print_field
+
+    def print_array(self, o, toplevel=False):
+        '''Convert JSON array to VPP API array'''
+        write = self.stream.write
+
+        forloop = '''\
+    {{
+        int i;
+        cJSON *array = cJSON_GetObjectItem(o, "{n}");
+        int size = cJSON_GetArraySize(array);
+        if (size != {lfield}) return 0;
+        for (i = 0; i < size; i++) {{
+            cJSON *e = cJSON_GetArrayItem(array, i);
+            {call}
+        }}
+    }}
+'''
+        forloop_vla = '''\
+    {{
+        int i;
+        cJSON *array = cJSON_GetObjectItem(o, "{n}");
+        int size = cJSON_GetArraySize(array);
+        {lfield} = size;
+        {msgvar} = realloc({msgvar}, {msgsize} + sizeof({t}) * size);
+        {t} *d = (void *){msgvar} + {msgsize};
+        {msgsize} += sizeof({t}) * size;
+        for (i = 0; i < size; i++) {{
+            cJSON *e = cJSON_GetArrayItem(array, i);
+            {call}
+        }}
+    }}
+'''
+        t = o.fieldtype
+        if o.fieldtype == 'string':
+            self.print_string(o, toplevel)
+            return
+
+        lfield = 'a->' + o.lengthfield if o.lengthfield else o.length
+        msgvar = "a" if toplevel else "mp"
+        msgsize = "l" if toplevel else "*len"
+
+        if o.fieldtype == 'u8':
+            if o.lengthfield:
+                write('    s = u8string_fromjson(o, "{}");\n'
+                      .format(o.fieldname))
+                write('    if (!s) return 0;\n')
+                write('    {} = vec_len(s);\n'.format(lfield))
+
+                write('    {msgvar} = realloc({msgvar}, {msgsize} + '
+                      'vec_len(s));\n'.format(msgvar=msgvar, msgsize=msgsize))
+                write('    memcpy((void *){msgvar} + {msgsize}, s, '
+                      'vec_len(s));\n'.format(msgvar=msgvar, msgsize=msgsize))
+                write('    {msgsize} += vec_len(s);\n'.format(msgsize=msgsize))
+
+                write('    vec_free(s);\n')
+            else:
+                write('    u8string_fromjson2(o, "{n}", a->{n});\n'
+                      .format(n=o.fieldname))
+            return
+
+        is_bt = self.is_base_type(o.fieldtype)
+
+        if o.lengthfield:
+            if is_bt:
+                call = ('vl_api_{t}_fromjson(e, &d[i]);'
+                        .format(t=o.fieldtype))
+            else:
+                call = ('{t}_fromjson({msgvar}, len, e, &d[i]); '
+                        .format(t=o.fieldtype, msgvar=msgvar))
+            write(forloop_vla.format(lfield=lfield,
+                                     t=o.fieldtype,
+                                     n=o.fieldname,
+                                     call=call,
+                                     msgvar=msgvar,
+                                     msgsize=msgsize))
+        else:
+            if is_bt:
+                call = ('vl_api_{t}_fromjson(e, &a->{n}[i]);'
+                        .format(t=t, n=o.fieldname))
+            else:
+                call = ('a = {}_fromjson({}, len, e, &a->{}[i]);'
+                        .format(t, msgvar, o.fieldname))
+            write(forloop.format(lfield=lfield,
+                                 t=t,
+                                 n=o.fieldname,
+                                 call=call,
+                                 msgvar=msgvar,
+                                 msgsize=msgsize))
+
+    _dispatch['Array'] = print_array
+
+    def print_enum(self, o):
+        '''Convert to JSON enum(string) to VPP API enum (int)'''
+        write = self.stream.write
+        write('static inline void *vl_api_{n}_t_fromjson '
+              '(void *mp, int *len, cJSON *o, vl_api_{n}_t *a) {{\n'
+              .format(n=o.name))
+        write('    char *p = cJSON_GetStringValue(o);\n')
+        for b in o.block:
+            write('    if (strcmp(p, "{}") == 0) {{*a = {}; return mp;}}\n'
+                  .format(b[0], b[1]))
+        write('   return 0;\n')
+        write('}\n')
+
+    _dispatch['Enum'] = print_enum
+
+    def print_typedef(self, o):
+        '''Convert from JSON object to VPP API binary representation'''
+        write = self.stream.write
+
+        write('static inline void *vl_api_{name}_t_fromjson (void *mp, '
+              'int *len, cJSON *o, vl_api_{name}_t *a) {{\n'
+              .format(name=o.name))
+        write('    cJSON *item __attribute__ ((unused));\n')
+        write('    u8 *s __attribute__ ((unused));\n')
+        for t in o.block:
+            if t.type == 'Field' and t.is_lengthfield:
+                continue
+            write('    item = cJSON_GetObjectItem(o, "{}");\n'
+                  .format(t.fieldname))
+            write('    if (!item) return 0;\n')
+
+            self._dispatch[t.type](self, t)
+
+        write('    return mp;\n')
+        write('}\n')
+
+    def print_union(self, o):
+        '''Convert JSON object to VPP API binary union'''
+        write = self.stream.write
+
+        write('static inline void *vl_api_{name}_t_fromjson (void *mp, '
+              'int *len, cJSON *o, vl_api_{name}_t *a) {{\n'
+              .format(name=o.name))
+        write('    cJSON *item __attribute__ ((unused));\n')
+        write('    u8 *s __attribute__ ((unused));\n')
+        for t in o.block:
+            if t.type == 'Field' and t.is_lengthfield:
+                continue
+            write('    item = cJSON_GetObjectItem(o, "{}");\n'
+                  .format(t.fieldname))
+            write('    if (item) {\n')
+            self._dispatch[t.type](self, t)
+            write('    };\n')
+        write('    return mp;\n')
+        write('}\n')
+
+    def print_define(self, o):
+        '''Convert JSON object to VPP API message'''
+        write = self.stream.write
+        write('static inline vl_api_{name}_t *vl_api_{name}_t_fromjson '
+              '(cJSON *o, int *len) {{\n'.format(name=o.name))
+        write('    cJSON *item __attribute__ ((unused));\n')
+        write('    u8 *s __attribute__ ((unused));\n')
+        write('    int l = sizeof(vl_api_{}_t);\n'.format(o.name))
+        write('    vl_api_{}_t *a = malloc(l);\n'.format(o.name))
+
+        for t in o.block:
+            if t.fieldname in self.noprint_fields:
+                continue
+            if t.type == 'Field' and t.is_lengthfield:
+                continue
+            write('    // processing {}: {} {}\n'
+                  .format(o.name, t.fieldtype, t.fieldname))
+
+            write('    item = cJSON_GetObjectItem(o, "{}");\n'
+                  .format(t.fieldname))
+            write('    if (!item) return 0;\n')
+            self._dispatch[t.type](self, t, toplevel=True)
+            write('\n')
+
+        write('\n')
+        write('    *len = l;\n')
+        write('    return a;\n')
+        write('}\n')
+
+    def print_using(self, o):
+        '''Convert JSON field to VPP type alias'''
+        write = self.stream.write
+
+        if o.manual_print:
+            return
+
+        t = o.using
+        write('static inline void *vl_api_{name}_t_fromjson (void *mp, '
+              'int *len, cJSON *o, vl_api_{name}_t *a) {{\n'
+              .format(name=o.name))
+        if 'length' in o.alias:
+            if t.fieldtype != 'u8':
+                raise ValueError("Error in processing type {} for {}"
+                                 .format(t.fieldtype, o.name))
+            write('    vl_api_u8_string_fromjson(o, (u8 *)a, {});\n'
+                  .format(o.alias['length']))
+        else:
+            write('    vl_api_{t}_fromjson(o, ({t} *)a);\n'
+                  .format(t=t.fieldtype))
+
+        write('    return mp;\n')
+        write('}\n')
+
+    _dispatch['Typedef'] = print_typedef
+    _dispatch['Define'] = print_define
+    _dispatch['Using'] = print_using
+    _dispatch['Union'] = print_union
+
+    def generate_function(self, t):
+        '''Main entry point'''
+        write = self.stream.write
+        if t.manual_print:
+            write('/* Manual print {} */\n'.format(t.name))
+            return
+        self._dispatch[t.type](self, t)
+
+    def generate_types(self):
+        '''Main entry point'''
+        for t in self.types:
+            self.generate_function(t)
+
+    def generate_defines(self):
+        '''Main entry point'''
+        for t in self.defines:
+            self.generate_function(t)
+
+
+def generate_tojson(s, modulename, stream):
+    '''Generate all functions to convert from API to JSON'''
+    write = stream.write
+
+    write('/* Imported API files */\n')
+    for i in s['Import']:
+        f = i.filename.replace('plugins/', '')
+        write('#include <{}_tojson.h>\n'.format(f))
+
+    pp = ToJSON(modulename, s['types'], s['Define'], s['imported']['types'],
+                stream)
+    pp.header()
+    pp.generate_types()
+    pp.generate_defines()
+    pp.footer()
+    return ''
+
+
+def generate_fromjson(s, modulename, stream):
+    '''Generate all functions to convert from JSON to API'''
+    write = stream.write
+    write('/* Imported API files */\n')
+    for i in s['Import']:
+        f = i.filename.replace('plugins/', '')
+        write('#include <{}_fromjson.h>\n'.format(f))
+
+    pp = FromJSON(modulename, s['types'], s['Define'], s['imported']['types'],
+                  stream)
+    pp.header()
+    pp.generate_types()
+    pp.generate_defines()
+    pp.footer()
+
+    return ''
+
+###############################################################################
+
+
+DATESTRING = datetime.datetime.utcfromtimestamp(
     int(os.environ.get('SOURCE_DATE_EPOCH', time.time())))
-input_filename = 'inputfil'
-top_boilerplate = '''\
+TOP_BOILERPLATE = '''\
 /*
  * VLIB API definitions {datestring}
  * Input file: {input_filename}
@@ -32,7 +634,7 @@ top_boilerplate = '''\
 #define VL_API_PACKED(x) x __attribute__ ((packed))
 '''
 
-bottom_boilerplate = '''\
+BOTTOM_BOILERPLATE = '''\
 /****** API CRC (whole file) *****/
 
 #ifdef vl_api_version
@@ -43,6 +645,7 @@ vl_api_version({input_filename}, {file_crc:#08x})
 
 
 def msg_ids(s):
+    '''Generate macro to map API message id to handler'''
     output = '''\
 
 /****** Message ID / handler enum ******/
@@ -59,6 +662,7 @@ def msg_ids(s):
 
 
 def msg_names(s):
+    '''Generate calls to name mapping macro'''
     output = '''\
 
 /****** Message names ******/
@@ -75,6 +679,7 @@ def msg_names(s):
 
 
 def msg_name_crc_list(s, suffix):
+    '''Generate list of names to CRC mappings'''
     output = '''\
 
 /****** Message name, crc list ******/
@@ -92,6 +697,7 @@ def msg_name_crc_list(s, suffix):
 
 
 def api2c(fieldtype):
+    '''Map between API type names and internal VPP type names'''
     mappingtable = {'string': 'vl_api_string_t', }
     if fieldtype in mappingtable:
         return mappingtable[fieldtype]
@@ -99,7 +705,7 @@ def api2c(fieldtype):
 
 
 def typedefs(filename):
-
+    '''Include in the main files to the types file'''
     output = '''\
 
 /****** Typedefs ******/
@@ -111,7 +717,7 @@ def typedefs(filename):
     return output
 
 
-format_strings = {'u8': '%u',
+FORMAT_STRINGS = {'u8': '%u',
                   'bool': '%u',
                   'i8': '%d',
                   'u16': '%u',
@@ -122,18 +728,20 @@ format_strings = {'u8': '%u',
                   'i64': '%lld',
                   'f64': '%.2f'}
 
-noprint_fields = {'_vl_msg_id': None,
-                  'client_index': None,
-                  'context': None}
-
 
 class Printfun():
+    '''Functions for pretty printing VPP API messages'''
     _dispatch = {}
+    noprint_fields = {'_vl_msg_id': None,
+                      'client_index': None,
+                      'context': None}
 
     def __init__(self, stream):
         self.stream = stream
 
-    def print_string(self, o, stream):
+    @staticmethod
+    def print_string(o, stream):
+        '''Pretty print a vl_api_string_t'''
         write = stream.write
         if o.modern_vla:
             write('    if (vl_api_string_len(&a->{f}) > 0) {{\n'
@@ -151,11 +759,12 @@ class Printfun():
                   .format(f=o.fieldname))
 
     def print_field(self, o, stream):
+        '''Pretty print API field'''
         write = stream.write
-        if o.fieldname in noprint_fields:
+        if o.fieldname in self.noprint_fields:
             return
-        if o.fieldtype in format_strings:
-            f = format_strings[o.fieldtype]
+        if o.fieldtype in FORMAT_STRINGS:
+            f = FORMAT_STRINGS[o.fieldtype]
             write('    s = format(s, "\\n%U{n}: {f}", '
                   'format_white_space, indent, a->{n});\n'
                   .format(n=o.fieldname, f=f))
@@ -168,6 +777,7 @@ class Printfun():
     _dispatch['Field'] = print_field
 
     def print_array(self, o, stream):
+        '''Pretty print API array'''
         write = stream.write
 
         forloop = '''\
@@ -185,7 +795,8 @@ class Printfun():
 '''
 
         if o.fieldtype == 'string':
-            return self.print_string(o, stream)
+            self.print_string(o, stream)
+            return
 
         if o.fieldtype == 'u8':
             if o.lengthfield:
@@ -199,29 +810,33 @@ class Printfun():
             return
 
         lfield = 'a->' + o.lengthfield if o.lengthfield else o.length
-        if o.fieldtype in format_strings:
+        if o.fieldtype in FORMAT_STRINGS:
             write(forloop_format.format(lfield=lfield,
-                                        t=format_strings[o.fieldtype],
+                                        t=FORMAT_STRINGS[o.fieldtype],
                                         n=o.fieldname))
         else:
             write(forloop.format(lfield=lfield, t=o.fieldtype, n=o.fieldname))
 
     _dispatch['Array'] = print_array
 
-    def print_alias(self, k, v, stream):
+    @staticmethod
+    def print_alias(k, v, stream):
+        '''Pretty print type alias'''
         write = stream.write
         if ('length' in v.alias and v.alias['length'] and
                 v.alias['type'] == 'u8'):
             write('    return format(s, "%U", format_hex_bytes, a, {});\n'
                   .format(v.alias['length']))
-        elif v.alias['type'] in format_strings:
+        elif v.alias['type'] in FORMAT_STRINGS:
             write('    return format(s, "{}", *a);\n'
-                  .format(format_strings[v.alias['type']]))
+                  .format(FORMAT_STRINGS[v.alias['type']]))
         else:
             write('    return format(s, "{} (print not implemented)");\n'
                   .format(k))
 
-    def print_enum(self, o, stream):
+    @staticmethod
+    def print_enum(o, stream):
+        '''Pretty print API enum'''
         write = stream.write
         write("    switch(*a) {\n")
         for b in o:
@@ -232,6 +847,7 @@ class Printfun():
     _dispatch['Enum'] = print_enum
 
     def print_obj(self, o, stream):
+        '''Entry point'''
         write = stream.write
 
         if o.type in self._dispatch:
@@ -242,6 +858,7 @@ class Printfun():
 
 
 def printfun(objs, stream, modulename):
+    '''Main entry point for pretty print function generation'''
     write = stream.write
 
     h = '''\
@@ -294,6 +911,7 @@ static inline void *vl_api_{name}_t_print (vl_api_{name}_t *a, void *handle)
 
 
 def printfun_types(objs, stream, modulename):
+    '''Pretty print API types'''
     write = stream.write
     pp = Printfun(stream)
 
@@ -345,7 +963,8 @@ static inline u8 *format_vl_api_{name}_t (u8 *s, va_list * args)
     write("\n#endif /* vl_printfun_types */\n")
 
 
-def imports(imports):
+def generate_imports(imports):
+    '''Add #include matching the API import statements'''
     output = '/* Imported API files */\n'
     output += '#ifndef vl_api_version\n'
 
@@ -356,7 +975,7 @@ def imports(imports):
     return output
 
 
-endian_strings = {
+ENDIAN_STRINGS = {
     'u16': 'clib_net_to_host_u16',
     'u32': 'clib_net_to_host_u32',
     'u64': 'clib_net_to_host_u64',
@@ -368,6 +987,7 @@ endian_strings = {
 
 
 def endianfun_array(o):
+    '''Generate endian functions for arrays'''
     forloop = '''\
     for (i = 0; i < {length}; i++) {{
         a->{name}[i] = {format}(a->{name}[i]);
@@ -385,10 +1005,10 @@ def endianfun_array(o):
         output += '    /* a->{n} = a->{n} (no-op) */\n'.format(n=o.fieldname)
     else:
         lfield = 'a->' + o.lengthfield if o.lengthfield else o.length
-        if o.fieldtype in endian_strings:
+        if o.fieldtype in ENDIAN_STRINGS:
             output += (forloop
                        .format(length=lfield,
-                               format=endian_strings[o.fieldtype],
+                               format=ENDIAN_STRINGS[o.fieldtype],
                                name=o.fieldname))
         else:
             output += (forloop_format
@@ -396,23 +1016,26 @@ def endianfun_array(o):
                                name=o.fieldname))
     return output
 
-no_endian_conversion = {'client_index': None}
+
+NO_ENDIAN_CONVERSION = {'client_index': None}
+
 
 def endianfun_obj(o):
+    '''Generate endian conversion function for type'''
     output = ''
     if o.type == 'Array':
         return endianfun_array(o)
-    elif o.type != 'Field':
+    if o.type != 'Field':
         output += ('    s = format(s, "\\n{} {} {} (print not implemented");\n'
                    .format(o.type, o.fieldtype, o.fieldname))
         return output
-    if o.fieldname in no_endian_conversion:
+    if o.fieldname in NO_ENDIAN_CONVERSION:
         output += '    /* a->{n} = a->{n} (no-op) */\n'.format(n=o.fieldname)
         return output
-    if o.fieldtype in endian_strings:
+    if o.fieldtype in ENDIAN_STRINGS:
         output += ('    a->{name} = {format}(a->{name});\n'
                    .format(name=o.fieldname,
-                           format=endian_strings[o.fieldtype]))
+                           format=ENDIAN_STRINGS[o.fieldtype]))
     elif o.fieldtype.startswith('vl_api_'):
         output += ('    {type}_endian(&a->{name});\n'
                    .format(type=o.fieldtype, name=o.fieldname))
@@ -423,6 +1046,7 @@ def endianfun_obj(o):
 
 
 def endianfun(objs, modulename):
+    '''Main entry point for endian function generation'''
     output = '''\
 
 /****** Endian swap functions *****/\n\
@@ -449,9 +1073,9 @@ static inline void vl_api_{name}_t_endian (vl_api_{name}_t *a)
     for t in objs:
         if t.__class__.__name__ == 'Enum':
             output += signature.format(name=t.name)
-            if t.enumtype in endian_strings:
+            if t.enumtype in ENDIAN_STRINGS:
                 output += ('    *a = {}(*a);\n'
-                           .format(endian_strings[t.enumtype]))
+                           .format(ENDIAN_STRINGS[t.enumtype]))
             else:
                 output += ('    /* a->{name} = a->{name} (no-op) */\n'
                            .format(name=t.name))
@@ -469,9 +1093,9 @@ static inline void vl_api_{name}_t_endian (vl_api_{name}_t *a)
                     t.alias['type'] == 'u8'):
                 output += ('    /* a->{name} = a->{name} (no-op) */\n'
                            .format(name=t.name))
-            elif t.alias['type'] in format_strings:
+            elif t.alias['type'] in FORMAT_STRINGS:
                 output += ('    *a = {}(*a);\n'
-                           .format(endian_strings[t.alias['type']]))
+                           .format(ENDIAN_STRINGS[t.alias['type']]))
             else:
                 output += '    /* Not Implemented yet {} */'.format(t.name)
             output += '}\n\n'
@@ -490,6 +1114,7 @@ static inline void vl_api_{name}_t_endian (vl_api_{name}_t *a)
 
 
 def version_tuple(s, module):
+    '''Generate semantic version string'''
     output = '''\
 /****** Version tuple *****/
 
@@ -508,9 +1133,10 @@ def version_tuple(s, module):
 
 
 def generate_include_enum(s, module, stream):
+    '''Generate <name>.api_enum.h'''
     write = stream.write
 
-    if len(s['Define']):
+    if 'Define' in s:
         write('typedef enum {\n')
         for t in s['Define']:
             write('   VL_API_{},\n'.format(t.name.upper()))
@@ -518,7 +1144,8 @@ def generate_include_enum(s, module, stream):
         write('}} vl_api_{}_enum_t;\n'.format(module))
 
 
-def generate_include_counters(s, module, stream):
+def generate_include_counters(s, stream):
+    '''Include file for the counter data model types.'''
     write = stream.write
 
     for counters in s:
@@ -530,14 +1157,11 @@ def generate_include_counters(s, module, stream):
         write('   {}_N_ERROR\n'.format(csetname.upper()))
         write('}} vl_counter_{}_enum_t;\n'.format(csetname))
 
-        # write('extern char *{}_error_strings[];\n'.format(csetname))
-        # write('extern char *{}_description_strings[];\n'.format(csetname))
         write('extern vl_counter_t {}_error_counters[];\n'.format(csetname))
 
-#
-# Generate separate API _types file.
-#
+
 def generate_include_types(s, module, stream):
+    '''Generate separate API _types file.'''
     write = stream.write
 
     write('#ifndef included_{module}_api_types_h\n'.format(module=module))
@@ -546,11 +1170,14 @@ def generate_include_types(s, module, stream):
     if 'version' in s['Option']:
         v = s['Option']['version']
         (major, minor, patch) = v.split('.')
-        write('#define VL_API_{m}_API_VERSION_MAJOR {v}\n'.format(m=module.upper(), v=major))
-        write('#define VL_API_{m}_API_VERSION_MINOR {v}\n'.format(m=module.upper(), v=minor))
-        write('#define VL_API_{m}_API_VERSION_PATCH {v}\n'.format(m=module.upper(), v=patch))
-
-    if len(s['Import']):
+        write('#define VL_API_{m}_API_VERSION_MAJOR {v}\n'
+              .format(m=module.upper(), v=major))
+        write('#define VL_API_{m}_API_VERSION_MINOR {v}\n'
+              .format(m=module.upper(), v=minor))
+        write('#define VL_API_{m}_API_VERSION_PATCH {v}\n'
+              .format(m=module.upper(), v=patch))
+
+    if 'Import' in s:
         write('/* Imported API files */\n')
         for i in s['Import']:
             filename = i.filename.replace('plugins/', '')
@@ -560,7 +1187,8 @@ def generate_include_types(s, module, stream):
         tname = o.__class__.__name__
         if tname == 'Using':
             if 'length' in o.alias:
-                write('typedef %s vl_api_%s_t[%s];\n' % (o.alias['type'], o.name, o.alias['length']))
+                write('typedef %s vl_api_%s_t[%s];\n' %
+                      (o.alias['type'], o.name, o.alias['length']))
             else:
                 write('typedef %s vl_api_%s_t;\n' % (o.alias['type'], o.name))
         elif tname == 'Enum':
@@ -580,20 +1208,21 @@ def generate_include_types(s, module, stream):
                       % (size1, size2, err_str))
         else:
             if tname == 'Union':
-                write("typedef union __attribute__ ((packed)) _vl_api_%s {\n" % o.name)
+                write("typedef union __attribute__ ((packed)) _vl_api_%s {\n"
+                      % o.name)
             else:
                 write(("typedef struct __attribute__ ((packed)) _vl_api_%s {\n")
-                           % o.name)
+                      % o.name)
             for b in o.block:
                 if b.type == 'Option':
                     continue
                 if b.type == 'Field':
-                      write("    %s %s;\n" % (api2c(b.fieldtype),
-                                              b.fieldname))
+                    write("    %s %s;\n" % (api2c(b.fieldtype),
+                                            b.fieldname))
                 elif b.type == 'Array':
                     if b.lengthfield:
-                      write("    %s %s[0];\n" % (api2c(b.fieldtype),
-                                                 b.fieldname))
+                        write("    %s %s[0];\n" % (api2c(b.fieldtype),
+                                                   b.fieldname))
                     else:
                         # Fixed length strings decay to nul terminated u8
                         if b.fieldtype == 'string':
@@ -623,6 +1252,7 @@ def generate_include_types(s, module, stream):
 
 def generate_c_boilerplate(services, defines, counters, file_crc,
                            module, stream):
+    '''VPP side plugin.'''
     write = stream.write
     define_hash = {d.name: d for d in defines}
 
@@ -644,34 +1274,36 @@ def generate_c_boilerplate(services, defines, counters, file_crc,
     write('setup_message_id_table (void) {\n')
     write('   api_main_t *am = my_api_main;\n')
     write('   vl_msg_api_msg_config_t c;\n')
-    write('   u16 msg_id_base = vl_msg_api_get_msg_ids ("{}_{crc:08x}", VL_MSG_{m}_LAST);\n'
+    write('   u16 msg_id_base = vl_msg_api_get_msg_ids ("{}_{crc:08x}", '
+          'VL_MSG_{m}_LAST);\n'
           .format(module, crc=file_crc, m=module.upper()))
 
-
     for d in defines:
         write('   vl_msg_api_add_msg_name_crc (am, "{n}_{crc:08x}",\n'
               '                                VL_API_{ID} + msg_id_base);\n'
               .format(n=d.name, ID=d.name.upper(), crc=d.crc))
     for s in services:
         d = define_hash[s.caller]
-        write('   c = (vl_msg_api_msg_config_t) {{.id = VL_API_{ID} + msg_id_base,\n'
-              '                                  .name = "{n}",\n'
-              '                                  .handler = vl_api_{n}_t_handler,\n'
-              '                                  .cleanup = vl_noop_handler,\n'
-              '                                  .endian = vl_api_{n}_t_endian,\n'
-              '                                  .print = vl_api_{n}_t_print,\n'
-              '                                  .is_autoendian = 0}};\n'
+        write('   c = (vl_msg_api_msg_config_t) '
+              ' {{.id = VL_API_{ID} + msg_id_base,\n'
+              '   .name = "{n}",\n'
+              '   .handler = vl_api_{n}_t_handler,\n'
+              '   .cleanup = vl_noop_handler,\n'
+              '   .endian = vl_api_{n}_t_endian,\n'
+              '   .print = vl_api_{n}_t_print,\n'
+              '   .is_autoendian = 0}};\n'
               .format(n=s.caller, ID=s.caller.upper()))
         write('   vl_msg_api_config (&c);\n')
         try:
             d = define_hash[s.reply]
-            write('   c = (vl_msg_api_msg_config_t) {{.id = VL_API_{ID} + msg_id_base,\n'
-                  '                                  .name = "{n}",\n'
-                  '                                  .handler = 0,\n'
-                  '                                  .cleanup = vl_noop_handler,\n'
-                  '                                  .endian = vl_api_{n}_t_endian,\n'
-                  '                                  .print = vl_api_{n}_t_print,\n'
-                  '                                  .is_autoendian = 0}};\n'
+            write('   c = (vl_msg_api_msg_config_t) '
+                  '{{.id = VL_API_{ID} + msg_id_base,\n'
+                  '  .name = "{n}",\n'
+                  '  .handler = 0,\n'
+                  '  .cleanup = vl_noop_handler,\n'
+                  '  .endian = vl_api_{n}_t_endian,\n'
+                  '  .print = vl_api_{n}_t_print,\n'
+                  '  .is_autoendian = 0}};\n'
                   .format(n=s.reply, ID=s.reply.upper()))
             write('   vl_msg_api_config (&c);\n')
         except KeyError:
@@ -686,16 +1318,6 @@ def generate_c_boilerplate(services, defines, counters, file_crc,
 
     for cnt in counters:
         csetname = cnt.name
-        '''
-        write('char *{}_error_strings[] = {{\n'.format(csetname))
-        for c in cnt.block:
-            write('   "{}",\n'.format(c['name']))
-        write('};\n')
-        write('char *{}_description_strings[] = {{\n'.format(csetname))
-        for c in cnt.block:
-            write('   "{}",\n'.format(c['description']))
-        write('};\n')
-        '''
         write('vl_counter_t {}_error_counters[] = {{\n'.format(csetname))
         for c in cnt.block:
             write('  {\n')
@@ -705,14 +1327,16 @@ def generate_c_boilerplate(services, defines, counters, file_crc,
             write('  },\n')
         write('};\n')
 
-def generate_c_test_boilerplate(services, defines, file_crc, module, plugin, stream):
+
+def generate_c_test_boilerplate(services, defines, file_crc, module, plugin,
+                                stream):
+    '''Generate code for legacy style VAT. To be deleted.'''
     write = stream.write
 
-    define_hash = {d.name:d for d in defines}
-    replies = {}
+    define_hash = {d.name: d for d in defines}
 
     hdr = '''\
-#define vl_endianfun           /* define message structures */
+#define vl_endianfun            /* define message structures */
 #include "{module}.api.h"
 #undef vl_endianfun
 
@@ -728,19 +1352,23 @@ def generate_c_test_boilerplate(services, defines, file_crc, module, plugin, str
     for s in services:
         try:
             d = define_hash[s.reply]
-        except:
+        except KeyError:
             continue
         if d.manual_print:
-            write('/* Manual definition requested for: vl_api_{n}_t_handler() */\n'
+            write('/*\n'
+                  ' * Manual definition requested for: \n'
+                  ' * vl_api_{n}_t_handler()\n'
+                  ' */\n'
                   .format(n=s.reply))
             continue
         if not define_hash[s.caller].autoreply:
-            write('/* Only autoreply is supported (vl_api_{n}_t_handler()) */\n'
+            write('/* Generation not supported (vl_api_{n}_t_handler()) */\n'
                   .format(n=s.reply))
             continue
         write('#ifndef VL_API_{n}_T_HANDLER\n'.format(n=s.reply.upper()))
         write('static void\n')
-        write('vl_api_{n}_t_handler (vl_api_{n}_t * mp) {{\n'.format(n=s.reply))
+        write('vl_api_{n}_t_handler (vl_api_{n}_t * mp) {{\n'
+              .format(n=s.reply))
         write('   vat_main_t * vam = {}_test_main.vat_main;\n'.format(module))
         write('   i32 retval = ntohl(mp->retval);\n')
         write('   if (vam->async_mode) {\n')
@@ -764,23 +1392,31 @@ def generate_c_test_boilerplate(services, defines, file_crc, module, plugin, str
     write('static void\n')
     write('setup_message_id_table (vat_main_t * vam, u16 msg_id_base) {\n')
     for s in services:
-        write('   vl_msg_api_set_handlers(VL_API_{ID} + msg_id_base, "{n}",\n'
-              '                           vl_api_{n}_t_handler, vl_noop_handler,\n'
-              '                           vl_api_{n}_t_endian, vl_api_{n}_t_print,\n'
+        write('   vl_msg_api_set_handlers(VL_API_{ID} + msg_id_base, '
+              '                           "{n}",\n'
+              '                           vl_api_{n}_t_handler, '
+              '                           vl_noop_handler,\n'
+              '                           vl_api_{n}_t_endian, '
+              '                           vl_api_{n}_t_print,\n'
               '                           sizeof(vl_api_{n}_t), 1);\n'
               .format(n=s.reply, ID=s.reply.upper()))
-        write('   hash_set_mem (vam->function_by_name, "{n}", api_{n});\n'.format(n=s.caller))
+        write('   hash_set_mem (vam->function_by_name, "{n}", api_{n});\n'
+              .format(n=s.caller))
         try:
             write('   hash_set_mem (vam->help_by_name, "{n}", "{help}");\n'
-                  .format(n=s.caller, help=define_hash[s.caller].options['vat_help']))
-        except:
+                  .format(n=s.caller,
+                          help=define_hash[s.caller].options['vat_help']))
+        except KeyError:
             pass
 
         # Events
         for e in s.events:
-            write('   vl_msg_api_set_handlers(VL_API_{ID} + msg_id_base, "{n}",\n'
-                  '                           vl_api_{n}_t_handler, vl_noop_handler,\n'
-                  '                           vl_api_{n}_t_endian, vl_api_{n}_t_print,\n'
+            write('   vl_msg_api_set_handlers(VL_API_{ID} + msg_id_base, '
+                  '                          "{n}",\n'
+                  '                           vl_api_{n}_t_handler, '
+                  '                           vl_noop_handler,\n'
+                  '                           vl_api_{n}_t_endian, '
+                  '                           vl_api_{n}_t_print,\n'
                   '                           sizeof(vl_api_{n}_t), 1);\n'
                   .format(n=e, ID=e.upper()))
 
@@ -788,14 +1424,17 @@ def generate_c_test_boilerplate(services, defines, file_crc, module, plugin, str
     if plugin:
         write('clib_error_t * vat_plugin_register (vat_main_t *vam)\n')
     else:
-        write('clib_error_t * vat_{}_plugin_register (vat_main_t *vam)\n'.format(module))
+        write('clib_error_t * vat_{}_plugin_register (vat_main_t *vam)\n'
+              .format(module))
     write('{\n')
     write('   {n}_test_main_t * mainp = &{n}_test_main;\n'.format(n=module))
     write('   mainp->vat_main = vam;\n')
-    write('   mainp->msg_id_base = vl_client_get_first_plugin_msg_id ("{n}_{crc:08x}");\n'
+    write('   mainp->msg_id_base = vl_client_get_first_plugin_msg_id '
+          '                       ("{n}_{crc:08x}");\n'
           .format(n=module, crc=file_crc))
     write('   if (mainp->msg_id_base == (u16) ~0)\n')
-    write('      return clib_error_return (0, "{} plugin not loaded...");\n'.format(module))
+    write('      return clib_error_return (0, "{} plugin not loaded...");\n'
+          .format(module))
     write('   setup_message_id_table (vam, mainp->msg_id_base);\n')
     write('#ifdef VL_API_LOCAL_SETUP_MESSAGE_ID_TABLE\n')
     write('    VL_API_LOCAL_SETUP_MESSAGE_ID_TABLE(vam);\n')
@@ -803,30 +1442,255 @@ def generate_c_test_boilerplate(services, defines, file_crc, module, plugin, str
     write('   return 0;\n')
     write('}\n')
 
+
+def apifunc(func):
+    '''Check if a method is generated already.'''
+    def _f(module, d, processed, *args):
+        if d.name in processed:
+            return None
+        processed[d.name] = True
+        return func(module, d, *args)
+    return _f
+
+
+def c_test_api_service(s, dump, stream):
+    '''Generate JSON code for a service.'''
+    write = stream.write
+
+    req_reply_template = '''\
+static cJSON *
+api_{n} (cJSON *o)
+{{
+  vl_api_{n}_t *mp;
+  int len;
+  if (!o) return 0;
+  mp = vl_api_{n}_t_fromjson(o, &len);
+  if (!mp) {{
+    fprintf(stderr, "Failed converting JSON to API\\n");
+    return 0;
+  }}
+
+  mp->_vl_msg_id = vac_get_msg_index(VL_API_{N}_CRC);
+  vl_api_{n}_t_endian(mp);
+  vac_write((char *)mp, len);
+  free(mp);
+
+  /* Read reply */
+  char *p;
+  int l;
+  vac_read(&p, &l, 5); // XXX: Fix timeout
+    // XXX Will fail in case of event received. Do loop
+  if (ntohs(*((u16 *)p)) != vac_get_msg_index(VL_API_{R}_CRC)) {{
+    fprintf(stderr, "Mismatched reply\\n");
+    return 0;
+  }}
+  vl_api_{r}_t *rmp = (vl_api_{r}_t *)p;
+  vl_api_{r}_t_endian(rmp);
+  return vl_api_{r}_t_tojson(rmp);
+}}
+
+'''
+    dump_details_template = '''\
+static cJSON *
+api_{n} (cJSON *o)
+{{
+  u16 msg_id = vac_get_msg_index(VL_API_{N}_CRC);
+  int len;
+  if (!o) return 0;
+  vl_api_{n}_t *mp = vl_api_{n}_t_fromjson(o, &len);
+  if (!mp) {{
+      fprintf(stderr, "Failed converting JSON to API\\n");
+      return 0;
+  }}
+  mp->_vl_msg_id = msg_id;
+  vl_api_{n}_t_endian(mp);
+  vac_write((char *)mp, len);
+  free(mp);
+
+  vat2_control_ping(123); // FIX CONTEXT
+  cJSON *reply = cJSON_CreateArray();
+
+  u16 ping_reply_msg_id = vac_get_msg_index(VL_API_CONTROL_PING_REPLY_CRC);
+  u16 details_msg_id = vac_get_msg_index(VL_API_{R}_CRC);
+
+  while (1) {{
+    /* Read reply */
+    char *p;
+    int l;
+    vac_read(&p, &l, 5); // XXX: Fix timeout
+
+    /* Message can be one of [_details, control_ping_reply
+     * or unrelated event]
+     */
+    u16 reply_msg_id = ntohs(*((u16 *)p));
+    if (reply_msg_id == ping_reply_msg_id) {{
+        break;
+    }}
+
+    if (reply_msg_id == details_msg_id) {{
+        vl_api_{r}_t *rmp = (vl_api_{r}_t *)p;
+        vl_api_{r}_t_endian(rmp);
+        cJSON_AddItemToArray(reply, vl_api_{r}_t_tojson(rmp));
+    }}
+  }}
+  return reply;
+}}
+
+'''
+    gets_details_reply_template = '''\
+static cJSON *
+api_{n} (cJSON *o)
+{{
+    u16 msg_id = vac_get_msg_index(VL_API_{N}_CRC);
+  int len = 0;
+  if (!o) return 0;
+  vl_api_{n}_t *mp = vl_api_{n}_t_fromjson(o, &len);
+  if (!mp) {{
+    fprintf(stderr, "Failed converting JSON to API\\n");
+    return 0;
+  }}
+  mp->_vl_msg_id = msg_id;
+
+  vl_api_{n}_t_endian(mp);
+  vac_write((char *)mp, len);
+  free(mp);
+
+  cJSON *reply = cJSON_CreateArray();
+
+  u16 reply_msg_id = vac_get_msg_index(VL_API_{R}_CRC);
+  u16 details_msg_id = vac_get_msg_index(VL_API_{D}_CRC);
+
+  while (1) {{
+    /* Read reply */
+    char *p;
+    int l;
+    vac_read(&p, &l, 5); // XXX: Fix timeout
+
+    /* Message can be one of [_details, control_ping_reply
+     * or unrelated event]
+     */
+    u16 msg_id = ntohs(*((u16 *)p));
+    if (msg_id == reply_msg_id) {{
+        vl_api_{r}_t *rmp = (vl_api_{r}_t *)p;
+        vl_api_{r}_t_endian(rmp);
+        cJSON_AddItemToArray(reply, vl_api_{r}_t_tojson(rmp));
+        break;
+    }}
+
+    if (msg_id == details_msg_id) {{
+        vl_api_{d}_t *rmp = (vl_api_{d}_t *)p;
+        vl_api_{d}_t_endian(rmp);
+        cJSON_AddItemToArray(reply, vl_api_{d}_t_tojson(rmp));
+    }}
+  }}
+  return reply;
+}}
+
+'''
+
+    if dump:
+        if s.stream_message:
+            write(gets_details_reply_template
+                  .format(n=s.caller, r=s.reply, N=s.caller.upper(),
+                          R=s.reply.upper(), d=s.stream_message,
+                          D=s.stream_message.upper()))
+        else:
+            write(dump_details_template.format(n=s.caller, r=s.reply,
+                                               N=s.caller.upper(),
+                                               R=s.reply.upper()))
+    else:
+        write(req_reply_template.format(n=s.caller, r=s.reply,
+                                        N=s.caller.upper(),
+                                        R=s.reply.upper()))
+
+
+def generate_c_test2_boilerplate(services, defines, module, stream):
+    '''Generate code for VAT2 plugin.'''
+    write = stream.write
+
+    define_hash = {d.name: d for d in defines}
+    # replies = {}
+
+    hdr = '''\
+#include <vlibapi/api.h>
+#include <vlibmemory/api.h>
+#include <vppinfra/error.h>
+#include <vnet/ip/ip_format_fns.h>
+#include <vnet/ethernet/ethernet_format_fns.h>
+
+#define vl_typedefs             /* define message structures */
+#include <vpp/api/vpe_all_api_h.h>
+#undef vl_typedefs
+
+#include "{module}.api_enum.h"
+#include "{module}.api_types.h"
+
+#define vl_endianfun           /* define message structures */
+#include "{module}.api.h"
+#undef vl_endianfun
+
+#define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__)
+#define vl_printfun
+#include "{module}.api.h"
+#undef vl_printfun
+
+#include "{module}.api_tojson.h"
+#include "{module}.api_fromjson.h"
+#include <vpp-api/client/vppapiclient.h>
+
+#include <vat2/vat2_helpers.h>
+
+'''
+
+    write(hdr.format(module=module))
+
+    for s in services:
+        if s.reply not in define_hash:
+            continue
+        c_test_api_service(s, s.stream, stream)
+
+    write('void vat2_register_function(char *, cJSON * (*)(cJSON *));\n')
+    # write('__attribute__((constructor))')
+    write('clib_error_t *\n')
+    write('vat2_register_plugin (void) {\n')
+    for s in services:
+        write('   vat2_register_function("{n}", api_{n});\n'
+              .format(n=s.caller))
+    write('   return 0;\n')
+    write('}\n')
+
+
 #
 # Plugin entry point
 #
-def run(args, input_filename, s):
+def run(args, apifilename, s):
+    '''Main plugin entry point.'''
     stream = StringIO()
 
     if not args.outputdir:
         sys.stderr.write('Missing --outputdir argument')
         return None
 
-    basename = os.path.basename(input_filename)
-    filename, file_extension = os.path.splitext(basename)
+    basename = os.path.basename(apifilename)
+    filename, _ = os.path.splitext(basename)
     modulename = filename.replace('.', '_')
     filename_enum = os.path.join(args.outputdir + '/' + basename + '_enum.h')
     filename_types = os.path.join(args.outputdir + '/' + basename + '_types.h')
     filename_c = os.path.join(args.outputdir + '/' + basename + '.c')
     filename_c_test = os.path.join(args.outputdir + '/' + basename + '_test.c')
+    filename_c_test2 = (os.path.join(args.outputdir + '/' + basename +
+                                     '_test2.c'))
+    filename_c_tojson = (os.path.join(args.outputdir +
+                                      '/' + basename + '_tojson.h'))
+    filename_c_fromjson = (os.path.join(args.outputdir + '/' +
+                                        basename + '_fromjson.h'))
 
     # Generate separate types file
     st = StringIO()
     generate_include_types(s, modulename, st)
-    with open (filename_types, 'w') as fd:
-        st.seek (0)
-        shutil.copyfileobj (st, fd)
+    with open(filename_types, 'w') as fd:
+        st.seek(0)
+        shutil.copyfileobj(st, fd)
     st.close()
 
     # Generate separate enum file
@@ -834,35 +1698,59 @@ def run(args, input_filename, s):
     st.write('#ifndef included_{}_api_enum_h\n'.format(modulename))
     st.write('#define included_{}_api_enum_h\n'.format(modulename))
     generate_include_enum(s, modulename, st)
-    generate_include_counters(s['Counters'], modulename, st)
+    generate_include_counters(s['Counters'], st)
     st.write('#endif\n')
-    with open (filename_enum, 'w') as fd:
-        st.seek (0)
-        shutil.copyfileobj (st, fd)
+    with open(filename_enum, 'w') as fd:
+        st.seek(0)
+        shutil.copyfileobj(st, fd)
     st.close()
 
     # Generate separate C file
     st = StringIO()
     generate_c_boilerplate(s['Service'], s['Define'], s['Counters'],
                            s['file_crc'], modulename, st)
-    with open (filename_c, 'w') as fd:
-        st.seek (0)
+    with open(filename_c, 'w') as fd:
+        st.seek(0)
         shutil.copyfileobj(st, fd)
     st.close()
 
     # Generate separate C test file
     st = StringIO()
-    plugin = True if 'plugin' in input_filename else False
-    generate_c_test_boilerplate(s['Service'], s['Define'], s['file_crc'],
+    plugin = bool('plugin' in apifilename)
+    generate_c_test_boilerplate(s['Service'], s['Define'],
+                                s['file_crc'],
                                 modulename, plugin, st)
-    with open (filename_c_test, 'w') as fd:
-        st.seek (0)
+    with open(filename_c_test, 'w') as fd:
+        st.seek(0)
+        shutil.copyfileobj(st, fd)
+    st.close()
+
+    # Fully autogenerated VATv2 C test file
+    st = StringIO()
+    generate_c_test2_boilerplate(s['Service'], s['Define'],
+                                 modulename, st)
+    with open(filename_c_test2, 'w') as fd:
+        st.seek(0)
+        shutil.copyfileobj(st, fd)
+    st.close()                  #
+
+    # Generate separate JSON file
+    st = StringIO()
+    generate_tojson(s, modulename, st)
+    with open(filename_c_tojson, 'w') as fd:
+        st.seek(0)
+        shutil.copyfileobj(st, fd)
+    st.close()
+    st = StringIO()
+    generate_fromjson(s, modulename, st)
+    with open(filename_c_fromjson, 'w') as fd:
+        st.seek(0)
         shutil.copyfileobj(st, fd)
     st.close()
 
-    output = top_boilerplate.format(datestring=datestring,
+    output = TOP_BOILERPLATE.format(datestring=DATESTRING,
                                     input_filename=basename)
-    output += imports(s['Import'])
+    output += generate_imports(s['Import'])
     output += msg_ids(s)
     output += msg_names(s)
     output += msg_name_crc_list(s, filename)
@@ -873,7 +1761,7 @@ def run(args, input_filename, s):
     stream.close()
     output += endianfun(s['types'] + s['Define'], modulename)
     output += version_tuple(s, basename)
-    output += bottom_boilerplate.format(input_filename=basename,
+    output += BOTTOM_BOILERPLATE.format(input_filename=basename,
                                         file_crc=s['file_crc'])
 
     return output