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diff --git a/src/vlib/unix/plugin.h b/src/vlib/unix/plugin.h
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+/*
+ * plugin.h: plugin handling
+ *
+ * Copyright (c) 2011 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_plugin_h__
+#define __included_plugin_h__
+
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+/*
+ * vlib plugin scheme
+ *
+ * Almost anything which can be made to work in a vlib unix
+ * application will also work in a vlib plugin.
+ *
+ * The elf-section magic which registers static objects
+ * works so long as plugins are preset when the vlib unix process
+ * starts. But wait: there's more...
+ *
+ * If an application calls vlib_load_new_plugins() -- possibly after
+ * changing vlib_plugin_main.plugin_path / vlib_plugin_main.plugin_name_filter,
+ * -- new plugins will be loaded. That, in turn, allows considerable
+ * flexibility in terms of adding feature code or fixing bugs without
+ * requiring the data-plane process to restart.
+ *
+ * When the plugin mechanism loads a plugin, it uses dlsym to locate
+ * and call the plugin's function vlib_plugin_register() if it exists.
+ * A plugin which expects to be loaded after the vlib application
+ * starts uses this callback to modify the application. If vlib_plugin_register
+ * returns non-zero, the plugin mechanism dlclose()'s the plugin.
+ *
+ * Applications control the plugin search path and name filter by
+ * declaring the variables vlib_plugin_path and vlib_plugin_name_filter.
+ * libvlib_unix.la supplies weak references for these symbols which
+ * effectively disable the scheme. In order for the elf-section magic to
+ * work, static plugins must be loaded at the earliest possible moment.
+ *
+ * An application can change these parameters at any time and call
+ * vlib_load_new_plugins().
+ */
+
+
+
+typedef struct
+{
+  u8 *name;
+  struct stat file_info;
+  void *handle;
+} plugin_info_t;
+
+typedef struct
+{
+  /* loaded plugin info */
+  plugin_info_t *plugin_info;
+  uword *plugin_by_name_hash;
+
+  /* path and name filter */
+  u8 *plugin_path;
+  u8 *plugin_name_filter;
+
+  /* handoff structure get callback */
+  void *handoff_structure_get_cb;
+
+  /* usual */
+  vlib_main_t *vlib_main;
+} plugin_main_t;
+
+extern plugin_main_t vlib_plugin_main;
+
+int vlib_plugin_early_init (vlib_main_t * vm);
+int vlib_load_new_plugins (plugin_main_t * pm, int from_early_init);
+
+#endif /* __included_plugin_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */