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, 195 insertions, 0 deletions

diff --git a/src/vat2/plugin.c b/src/vat2/plugin.c
new file mode 100644
index 00000000000..6b6d55ac9b0
--- /dev/null
+++ b/src/vat2/plugin.c
@@ -0,0 +1,195 @@
+/*
+ * 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 <dlfcn.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <vlib/vlib.h>
+#include "vat2.h"
+
+typedef struct
+{
+  u8 *name;
+  u8 *filename;
+  struct stat file_info;
+  void *handle;
+} plugin_info_t;
+
+/* loaded plugin info */
+plugin_info_t *plugin_info;
+
+static int
+load_one_plugin (plugin_info_t * pi)
+{
+  void *handle, *register_handle;
+  clib_error_t *(*fp) (void);
+  clib_error_t *error;
+
+  handle = dlopen ((char *) pi->name, RTLD_LAZY);
+
+  /*
+   * Note: this can happen if the plugin has an undefined symbol reference,
+   * so print a warning. Otherwise, the poor slob won't know what happened.
+   * Ask me how I know that...
+   */
+  if (handle == 0)
+    {
+      clib_warning ("%s", dlerror ());
+      return -1;
+    }
+
+  pi->handle = handle;
+
+  register_handle = dlsym (pi->handle, "vat2_register_plugin");
+  if (register_handle == 0)
+    {
+      clib_warning ("%s: symbol vat2_register_plugin not found", pi->name);
+      dlclose (handle);
+      return -1;
+    }
+
+  fp = register_handle;
+
+  error = (*fp) ();
+
+  if (error)
+    {
+      clib_error_report (error);
+      dlclose (handle);
+      return -1;
+    }
+
+  return 0;
+}
+
+static u8 **
+split_plugin_path (char *plugin_path)
+{
+  int i;
+  u8 **rv = 0;
+  u8 *path = (u8 *) plugin_path;
+  u8 *this = 0;
+
+  for (i = 0; i < vec_len (plugin_path); i++)
+    {
+      if (path[i] != ':')
+	{
+	  vec_add1 (this, path[i]);
+	  continue;
+	}
+      vec_add1 (this, 0);
+      vec_add1 (rv, this);
+      this = 0;
+    }
+  if (this)
+    {
+      vec_add1 (this, 0);
+      vec_add1 (rv, this);
+    }
+  return rv;
+}
+
+int
+vat2_load_plugins (char *path, char *filter, int *loaded)
+{
+  DIR *dp;
+  struct dirent *entry;
+  struct stat statb;
+  uword *p;
+  plugin_info_t *pi;
+  u8 **plugin_path;
+  int i;
+  int res = 0;
+  uword *plugin_by_name_hash = hash_create_string (0, sizeof (uword));
+
+  *loaded = 0;
+  plugin_path = split_plugin_path (path);
+
+  for (i = 0; i < vec_len (plugin_path); i++)
+    {
+      DBG ("Opening path: %s\n", plugin_path[i]);
+      dp = opendir ((char *) plugin_path[i]);
+
+      if (dp == 0)
+	continue;
+
+      while ((entry = readdir (dp)))
+	{
+	  u8 *plugin_name;
+
+	  if (filter)
+	    {
+	      int j;
+	      for (j = 0; j < vec_len (filter); j++)
+		if (entry->d_name[j] != filter[j])
+		  goto next;
+	    }
+
+	  plugin_name = format (0, "%s/%s%c", plugin_path[i],
+				entry->d_name, 0);
+
+	  /* unreadable */
+	  if (stat ((char *) plugin_name, &statb) < 0)
+	    {
+	    ignore:
+	      vec_free (plugin_name);
+	      continue;
+	    }
+
+	  /* a dir or other things which aren't plugins */
+	  if (!S_ISREG (statb.st_mode))
+	    goto ignore;
+
+	  p = hash_get_mem (plugin_by_name_hash, plugin_name);
+	  if (p == 0)
+	    {
+	      vec_add2 (plugin_info, pi, 1);
+	      pi->name = plugin_name;
+	      pi->file_info = statb;
+
+	      if (load_one_plugin (pi))
+		{
+		  res = -1;
+		  vec_free (plugin_name);
+		  _vec_len (plugin_info) = vec_len (plugin_info) - 1;
+		  continue;
+		}
+	      clib_memset (pi, 0, sizeof (*pi));
+	      hash_set_mem (plugin_by_name_hash, plugin_name,
+			    pi - plugin_info);
+	      *loaded = *loaded + 1;
+	    }
+	next:
+	  ;
+	}
+      closedir (dp);
+      vec_free (plugin_path[i]);
+    }
+  vec_free (plugin_path);
+  return res;
+}
+
+#define QUOTE_(x) #x
+#define QUOTE(x) QUOTE_(x)
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */