api: vat2 and json autogeneration for api messages

VAT2: A completely auto-generated replacement of VAT.
Reads input message in JSON from stdin and outputs received messages in JSON.

A VAT2 plugin is automatically built for a .api file.
There no longer a need for a separate _test.c.

Example:
vat2 show_version {}
{
        "_msgname":     "show_version_reply",
        "retval":       0,
        "program":      "vpe",
        "version":      "21.01-rc0~411-gf6eb348a6",
        "build_date":   "2020-11-19T09:49:25",
        "build_directory":      "/vpp/autogen3"
}

vat2 sw_interface_dump '{"sw_if_index": -1,
                         "name_filter_valid": 0,
                         "name_filter": ""}'
[{
                "_msgname":     "sw_interface_details",
                "sw_if_index":  0,
                "sup_sw_if_index":      0,
                "l2_address":   "00:00:00:00:00:00",
                "flags":        "Invalid ENUM",
                "type": "IF_API_TYPE_HARDWARE",
                "link_duplex":  "LINK_DUPLEX_API_UNKNOWN",
                "link_speed":   0,
                "link_mtu":     0,
                "mtu":  [0, 0, 0, 0],
                "sub_id":       0,
                "sub_number_of_tags":   0,
                "sub_outer_vlan_id":    0,
                "sub_inner_vlan_id":    0,
                "sub_if_flags": "Invalid ENUM",
                "vtr_op":       0,
                "vtr_push_dot1q":       0,
                "vtr_tag1":     0,
                "vtr_tag2":     0,
                "outer_tag":    0,
                "b_dmac":       "00:00:00:00:00:00",
                "b_smac":       "00:00:00:00:00:00",
                "b_vlanid":     0,
                "i_sid":        0,
                "interface_name":       "local0",
                "interface_dev_type":   "local",
                "tag":  ""
        }]

This is the first phase and vat2 is not integrated in packaging yet.

Type: feature
Signed-off-by: Ole Troan <ot@cisco.com>
Change-Id: Ib45ddeafb180ea7da8c5dc274a9274d7a4edc876
Signed-off-by: Ole Troan <ot@cisco.com>

1 files changed, 227 insertions, 0 deletions

diff --git a/src/vat2/main.c b/src/vat2/main.c
new file mode 100644
index 00000000000..5b042e23503
--- /dev/null
+++ b/src/vat2/main.c
@@ -0,0 +1,227 @@
+/*
+ * 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 <stdio.h>
+#include <stdbool.h>
+#include <ctype.h>
+#include <vlib/vlib.h>
+#include <vlibapi/api_types.h>
+#include <vppinfra/cJSON.h>
+
+/* VPP API client includes */
+#include <vpp-api/client/vppapiclient.h>
+
+#include <limits.h>
+#include "vat2.h"
+
+uword *function_by_name;
+bool debug = false;
+
+char *vat2_plugin_path;
+static void
+vat2_find_plugin_path ()
+{
+  char *p, path[PATH_MAX];
+  int rv;
+  u8 *s;
+
+  /* find executable path */
+  if ((rv = readlink ("/proc/self/exe", path, PATH_MAX - 1)) == -1)
+    return;
+
+  /* readlink doesn't provide null termination */
+  path[rv] = 0;
+
+  /* strip filename */
+  if ((p = strrchr (path, '/')) == 0)
+    return;
+  *p = 0;
+
+  /* strip bin/ */
+  if ((p = strrchr (path, '/')) == 0)
+    return;
+  *p = 0;
+
+  s = format (0, "%s/lib/" CLIB_TARGET_TRIPLET "/vat2_plugins:"
+              "%s/lib/vat2_plugins", path, path);
+  vec_add1 (s, 0);
+  vat2_plugin_path = (char *) s;
+}
+
+void
+vac_callback (unsigned char *data, int len)
+{
+  u16 result_msg_id = ntohs(*((u16 *)data));
+  DBG("Received something async: %d\n", result_msg_id);
+}
+
+int vat2_load_plugins (char *path, char *filter, int *loaded);
+
+static int
+register_function (void)
+{
+  int loaded;
+
+  vat2_find_plugin_path();
+  DBG("Plugin Path %s\n", vat2_plugin_path);
+  int rv = vat2_load_plugins(vat2_plugin_path, 0, &loaded);
+  DBG("Loaded %u plugins\n", loaded);
+  return rv;
+}
+
+void
+vat2_register_function(char *name, cJSON (*f)(cJSON *))
+{
+  hash_set_mem(function_by_name, name, f);
+}
+
+int main (int argc, char **argv)
+{
+  /* Create a heap of 64MB */
+  clib_mem_init (0, 64 << 20);
+  char *filename = 0;
+  int index;
+  int c;
+  opterr = 0;
+  cJSON *o = 0;
+  uword *p = 0;
+
+  while ((c = getopt (argc, argv, "df:")) != -1) {
+    switch (c) {
+      case 'd':
+        debug = true;
+        break;
+      case 'f':
+        filename = optarg;
+        break;
+      case '?':
+        if (optopt == 'f')
+          fprintf (stderr, "Option -%c requires an argument.\n", optopt);
+        else if (isprint (optopt))
+          fprintf (stderr, "Unknown option `-%c'.\n", optopt);
+        else
+          fprintf (stderr,
+                   "Unknown option character `\\x%x'.\n",
+                   optopt);
+        return 1;
+      default:
+        abort ();
+    }
+  }
+
+  DBG("debug = %d, filename = %s\n", debug, filename);
+
+  for (index = optind; index < argc; index++)
+    DBG ("Non-option argument %s\n", argv[index]);
+
+  index = optind;
+
+  /* Load plugins */
+  function_by_name = hash_create_string (0, sizeof (uword));
+  int res = register_function();
+  if (res < 0) {
+    fprintf(stderr, "%s: loading plugins failed\n", argv[0]);
+    exit(-1);
+  }
+
+  if (argc > index + 2) {
+    fprintf(stderr, "%s: Too many arguments\n", argv[0]);
+    exit(-1);
+  }
+
+  /* Read JSON from stdin, command line or file */
+  if (argc >= (index + 1)) {
+    p = hash_get_mem (function_by_name, argv[index]);
+    if (p == 0) {
+      fprintf(stderr, "%s: Unknown command: %s\n", argv[0], argv[index]);
+      exit(-1);
+    }
+  }
+
+  if (argc == (index + 2)) {
+    o = cJSON_Parse(argv[index+1]);
+    if (!o) {
+      fprintf(stderr, "%s: Failed parsing JSON input: %s\n", argv[0], cJSON_GetErrorPtr());
+      exit(-1);
+    }
+  }
+
+  if (filename) {
+    if (argc > index + 1) {
+      fprintf(stderr, "%s: Superfluous arguments when filename given\n", argv[0]);
+      exit(-1);
+    }
+
+    FILE *f = fopen(filename, "r");
+    size_t bufsize = 1024;
+    size_t n_read = 0;
+    size_t n;
+
+    if (!f) {
+      fprintf(stderr, "%s: can't open file: %s\n", argv[0], filename);
+      exit(-1);
+    }
+    char *buf = malloc(bufsize);
+    while ((n = fread(buf, 1, bufsize, f))) {
+      n_read += n;
+      if (n == bufsize)
+        buf = realloc(buf, bufsize);
+    }
+    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);
+      }
+    }
+  }
+
+  if (!o) {
+    fprintf(stderr, "%s: Failed parsing JSON input\n", argv[0]);
+    exit(-1);
+  }
+
+  if (vac_connect("vat2", 0, 0, 1024)) {
+    fprintf(stderr, "Failed connecting to VPP\n");
+    exit(-1);
+  }
+  if (!p) {
+    fprintf(stderr, "No such command\n");
+    exit(-1);
+  }
+
+  cJSON * (*fp) (cJSON *);
+  fp = (void *) p[0];
+  cJSON *r = (*fp) (o);
+
+  if (o)
+    cJSON_Delete(o);
+
+  if (r) {
+    char *output = cJSON_Print(r);
+    cJSON_Delete(r);
+    printf("%s\n", output);
+    free(output);
+  } else {
+    fprintf(stderr, "Call failed\n");
+    exit(-1);
+  }
+
+  vac_disconnect();
+  exit (0);
+
+}