src/vlib/unix/plugin.c - fdio/vpp - Gitiles

 /*
  * plugin.c: 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.
  */

 #include <vlib/unix/plugin.h>
 #include <vppinfra/elf.h>
 #include <dlfcn.h>
 #include <dirent.h>

 plugin_main_t vlib_plugin_main;

 char *vlib_plugin_path __attribute__ ((weak));
 char *vlib_plugin_path = "";
 char *vlib_plugin_app_version __attribute__ ((weak));
 char *vlib_plugin_app_version = "";

 void *
 vlib_get_plugin_symbol (char *plugin_name, char *symbol_name)
 {
   plugin_main_t *pm = &vlib_plugin_main;
   uword *p;
   plugin_info_t *pi;

   if ((p = hash_get_mem (pm->plugin_by_name_hash, plugin_name)) == 0)
     return 0;

   pi = vec_elt_at_index (pm->plugin_info, p[0]);
   return dlsym (pi->handle, symbol_name);
 }

 static char *
 str_array_to_vec (char *array, int len)
 {
   char c, *r = 0;
   int n = 0;

   do
     {
       c = array[n];
       vec_add1 (r, c);
     }
   while (c && ++n < len);

   if (c)
     vec_add1 (r, 0);

   return r;
 }

 static int
 load_one_plugin (plugin_main_t * pm, plugin_info_t * pi, int from_early_init)
 {
   void *handle;
   clib_error_t *error;
   elf_main_t em = { 0 };
   elf_section_t *section;
   u8 *data;
   char *version_required;
   vlib_plugin_registration_t *reg;
   plugin_config_t *pc = 0;
   uword *p;

   if (elf_read_file (&em, (char *) pi->filename))
     return -1;

   error = elf_get_section_by_name (&em, ".vlib_plugin_registration",
 				   &section);
   if (error)
     {
       clib_warning ("Not a plugin: %s\n", (char *) pi->name);
       return -1;
     }

   data = elf_get_section_contents (&em, section->index, 1);
   reg = (vlib_plugin_registration_t *) data;

   if (vec_len (data) != sizeof (*reg))
     {
       clib_warning ("vlib_plugin_registration size mismatch in plugin %s\n",
 		    (char *) pi->name);
       goto error;
     }

   p = hash_get_mem (pm->config_index_by_name, pi->name);
   if (p)
     {
       pc = vec_elt_at_index (pm->configs, p[0]);
       if (pc->is_disabled)
 	{
 	  clib_warning ("Plugin disabled: %s", pi->name);
 	  goto error;
 	}
       if (reg->default_disabled && pc->is_enabled == 0)
 	{
 	  clib_warning ("Plugin disabled (default): %s", pi->name);
 	  goto error;
 	}
     }
   else if (reg->default_disabled)
     {
       clib_warning ("Plugin disabled (default): %s", pi->name);
       goto error;
     }

   version_required = str_array_to_vec ((char *) &reg->version_required,
 				       sizeof (reg->version_required));

   if ((strlen (version_required) > 0) &&
       (strncmp (vlib_plugin_app_version, version_required,
 		strlen (version_required))))
     {
       clib_warning ("Plugin %s version mismatch: %s != %s",
 		    pi->name, vlib_plugin_app_version, reg->version_required);
       if (!(pc && pc->skip_version_check == 1))
 	{
 	  vec_free (version_required);
 	  goto error;
 	}
     }

   vec_free (version_required);
   vec_free (data);
   elf_main_free (&em);

   handle = dlopen ((char *) pi->filename, RTLD_LAZY);

   if (handle == 0)
     {
       clib_warning ("%s", dlerror ());
       clib_warning ("Failed to load plugin '%s'", pi->name);
       os_exit (1);
     }

   pi->handle = handle;

   reg = dlsym (pi->handle, "vlib_plugin_registration");

   if (reg == 0)
     {
       /* This should never happen unless somebody chagnes registration macro */
       clib_warning ("Missing plugin registration in plugin '%s'", pi->name);
       os_exit (1);
     }

   pi->reg = reg;
   pi->version = str_array_to_vec ((char *) &reg->version,
 				  sizeof (reg->version));

   if (reg->early_init)
     {
       clib_error_t *(*ei) (vlib_main_t *);
       void *h;

       h = dlsym (pi->handle, reg->early_init);
       if (h)
 	{
 	  ei = h;
 	  error = (*ei) (pm->vlib_main);
 	  if (error)
 	    {
 	      clib_error_report (error);
 	      os_exit (1);
 	    }
 	}
       else
 	clib_warning ("Plugin %s: early init function %s set but not found",
 		      (char *) pi->name, reg->early_init);
     }

   if (reg->description)
     clib_warning ("Loaded plugin: %s (%s)", pi->name, reg->description);
   else
     clib_warning ("Loaded plugin: %s", pi->name);

   return 0;
 error:
   vec_free (data);
   elf_main_free (&em);
   return -1;
 }

 static u8 **
 split_plugin_path (plugin_main_t * pm)
 {
   int i;
   u8 **rv = 0;
   u8 *path = pm->plugin_path;
   u8 *this = 0;

   for (i = 0; i < vec_len (pm->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;
 }

 static int
 plugin_name_sort_cmp (void *a1, void *a2)
 {
   plugin_info_t *p1 = a1;
   plugin_info_t *p2 = a2;

   return strcmp ((char *) p1->name, (char *) p2->name);
 }

 int
 vlib_load_new_plugins (plugin_main_t * pm, int from_early_init)
 {
   DIR *dp;
   struct dirent *entry;
   struct stat statb;
   uword *p;
   plugin_info_t *pi;
   u8 **plugin_path;
   u32 *load_fail_indices = 0;
   int i;

   plugin_path = split_plugin_path (pm);

   for (i = 0; i < vec_len (plugin_path); i++)
     {
       dp = opendir ((char *) plugin_path[i]);

       if (dp == 0)
 	continue;

       while ((entry = readdir (dp)))
 	{
 	  u8 *plugin_name;
 	  u8 *filename;

 	  if (pm->plugin_name_filter)
 	    {
 	      int j;
 	      for (j = 0; j < vec_len (pm->plugin_name_filter); j++)
 		if (entry->d_name[j] != pm->plugin_name_filter[j])
 		  goto next;
 	    }

 	  filename = format (0, "%s/%s%c", plugin_path[i], entry->d_name, 0);

 	  /* Only accept .so */
 	  char *ext = strrchr ((const char *) filename, '.');
 	  /* unreadable */
 	  if (!ext || (strcmp (ext, ".so") != 0) ||
 	      stat ((char *) filename, &statb) < 0)
 	    {
 	    ignore:
 	      vec_free (filename);
 	      continue;
 	    }

 	  /* a dir or other things which aren't plugins */
 	  if (!S_ISREG (statb.st_mode))
 	    goto ignore;

 	  plugin_name = format (0, "%s%c", entry->d_name, 0);
 	  /* Have we seen this plugin already? */
 	  p = hash_get_mem (pm->plugin_by_name_hash, plugin_name);
 	  if (p == 0)
 	    {
 	      /* No, add it to the plugin vector */
 	      vec_add2 (pm->plugin_info, pi, 1);
 	      pi->name = plugin_name;
 	      pi->filename = filename;
 	      pi->file_info = statb;
 	      hash_set_mem (pm->plugin_by_name_hash, plugin_name,
 			    pi - pm->plugin_info);
 	    }
 	next:
 	  ;
 	}
       closedir (dp);
       vec_free (plugin_path[i]);
     }
   vec_free (plugin_path);


   /*
    * Sort the plugins by name. This is important.
    * API traces contain absolute message numbers.
    * Loading plugins in directory (vs. alphabetical) order
    * makes trace replay incredibly fragile.
    */
   vec_sort_with_function (pm->plugin_info, plugin_name_sort_cmp);

   /*
    * Attempt to load the plugins
    */
   for (i = 0; i < vec_len (pm->plugin_info); i++)
     {
       pi = vec_elt_at_index (pm->plugin_info, i);

       if (load_one_plugin (pm, pi, from_early_init))
 	{
 	  /* Make a note of any which fail to load */
 	  vec_add1 (load_fail_indices, i);
 	  hash_unset_mem (pm->plugin_by_name_hash, pi->name);
 	  vec_free (pi->name);
 	  vec_free (pi->filename);
 	}
     }

   /* Remove plugin info vector elements corresponding to load failures */
   if (vec_len (load_fail_indices) > 0)
     {
       for (i = vec_len (load_fail_indices) - 1; i >= 0; i--)
 	vec_delete (pm->plugin_info, 1, load_fail_indices[i]);
       vec_free (load_fail_indices);
     }

   /* Recreate the plugin name hash */
   for (i = 0; i < vec_len (pm->plugin_info); i++)
     {
       pi = vec_elt_at_index (pm->plugin_info, i);
       hash_unset_mem (pm->plugin_by_name_hash, pi->name);
       hash_set_mem (pm->plugin_by_name_hash, pi->name, pi - pm->plugin_info);
     }

   return 0;
 }

 int
 vlib_plugin_early_init (vlib_main_t * vm)
 {
   plugin_main_t *pm = &vlib_plugin_main;

   if (pm->plugin_path == 0)
     pm->plugin_path = format (0, "%s%c", vlib_plugin_path, 0);

   clib_warning ("plugin path %s", pm->plugin_path);

   pm->plugin_by_name_hash = hash_create_string (0, sizeof (uword));
   pm->vlib_main = vm;

   return vlib_load_new_plugins (pm, 1 /* from_early_init */ );
 }

 static clib_error_t *
 vlib_plugins_show_cmd_fn (vlib_main_t * vm,
 			  unformat_input_t * input, vlib_cli_command_t * cmd)
 {
   plugin_main_t *pm = &vlib_plugin_main;
   u8 *s = 0;
   u8 *key = 0;
   uword value = 0;
   int index = 1;
   plugin_info_t *pi;

   s = format (s, " Plugin path is: %s\n\n", pm->plugin_path);
   s = format (s, "     %-41s%-33s%s\n", "Plugin", "Version", "Description");

   /* *INDENT-OFF* */
   hash_foreach_mem (key, value, pm->plugin_by_name_hash,
     {
       if (key != 0)
         {
           pi = vec_elt_at_index (pm->plugin_info, value);
           s = format (s, "%3d. %-40s %-32s %s\n", index, key, pi->version,
 		      pi->reg->description ? pi->reg->description : "");
 	  index++;
         }
     });
   /* *INDENT-ON* */

   vlib_cli_output (vm, "%v", s);
   vec_free (s);
   return 0;
 }

 /* *INDENT-OFF* */
 VLIB_CLI_COMMAND (plugins_show_cmd, static) =
 {
   .path = "show plugins",
   .short_help = "show loaded plugins",
   .function = vlib_plugins_show_cmd_fn,
 };
 /* *INDENT-ON* */

 static clib_error_t *
 config_one_plugin (vlib_main_t * vm, char *name, unformat_input_t * input)
 {
   plugin_main_t *pm = &vlib_plugin_main;
   plugin_config_t *pc;
   clib_error_t *error = 0;
   uword *p;
   int is_enable = 0;
   int is_disable = 0;
   int skip_version_check = 0;

   if (pm->config_index_by_name == 0)
     pm->config_index_by_name = hash_create_string (0, sizeof (uword));

   p = hash_get_mem (pm->config_index_by_name, name);

   if (p)
     {
       error = clib_error_return (0, "plugin '%s' already configured", name);
       goto done;
     }

   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
       if (unformat (input, "enable"))
 	is_enable = 1;
       else if (unformat (input, "disable"))
 	is_disable = 1;
       else if (unformat (input, "skip-version-check"))
 	skip_version_check = 1;
       else
 	{
 	  error = clib_error_return (0, "unknown input '%U'",
 				     format_unformat_error, input);
 	  goto done;
 	}
     }

   if (is_enable && is_disable)
     {
       error = clib_error_return (0, "please specify either enable or disable"
 				 " for plugin '%s'", name);
       goto done;
     }

   vec_add2 (pm->configs, pc, 1);
   hash_set_mem (pm->config_index_by_name, name, pc - pm->configs);
   pc->is_enabled = is_enable;
   pc->is_disabled = is_disable;
   pc->skip_version_check = skip_version_check;
   pc->name = name;

 done:
   return error;
 }

 clib_error_t *
 vlib_plugin_config (vlib_main_t * vm, unformat_input_t * input)
 {
   plugin_main_t *pm = &vlib_plugin_main;
   clib_error_t *error = 0;
   unformat_input_t in;

   unformat_init (&in, 0, 0);

   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
       u8 *s, *v;
       if (unformat (input, "%s %v", &s, &v))
 	{
 	  if (strncmp ((const char *) s, "plugins", 8) == 0)
 	    {
 	      if (vec_len (in.buffer) > 0)
 		vec_add1 (in.buffer, ' ');
 	      vec_add (in.buffer, v, vec_len (v));
 	    }
 	}
       else
 	{
 	  error = clib_error_return (0, "unknown input '%U'",
 				     format_unformat_error, input);
 	  goto done;
 	}

       vec_free (v);
       vec_free (s);
     }
 done:
   input = &in;
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
       unformat_input_t sub_input;
       u8 *s = 0;
       if (unformat (input, "path %s", &s))
 	pm->plugin_path = s;
       else if (unformat (input, "plugin %s %U", &s,
 			 unformat_vlib_cli_sub_input, &sub_input))
 	{
 	  error = config_one_plugin (vm, (char *) s, &sub_input);
 	  unformat_free (&sub_input);
 	  if (error)
 	    goto done2;
 	}
       else
 	{
 	  error = clib_error_return (0, "unknown input '%U'",
 				     format_unformat_error, input);
 	  {
 	    vec_free (s);
 	    goto done2;
 	  }
 	}
     }

 done2:
   unformat_free (&in);
   return error;
 }

 /* discard whole 'plugins' section, as it is already consumed prior to
    plugin load */
 static clib_error_t *
 plugins_config (vlib_main_t * vm, unformat_input_t * input)
 {
   u8 *junk;

   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
       if (unformat (input, "%s", &junk))
 	{
 	  vec_free (junk);
 	  return 0;
 	}
       else
 	return clib_error_return (0, "unknown input '%U'",
 				  format_unformat_error, input);
     }
   return 0;
 }

 VLIB_CONFIG_FUNCTION (plugins_config, "plugins");

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* plugin.c: 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.
	*/

	#include <vlib/unix/plugin.h>
	#include <vppinfra/elf.h>
	#include <dlfcn.h>
	#include <dirent.h>

	plugin_main_t vlib_plugin_main;

	char *vlib_plugin_path __attribute__ ((weak));
	char *vlib_plugin_path = "";
	char *vlib_plugin_app_version __attribute__ ((weak));
	char *vlib_plugin_app_version = "";

	void *
	vlib_get_plugin_symbol (char plugin_name, char symbol_name)
	{
	plugin_main_t *pm = &vlib_plugin_main;
	uword *p;
	plugin_info_t *pi;

	if ((p = hash_get_mem (pm->plugin_by_name_hash, plugin_name)) == 0)
	return 0;

	pi = vec_elt_at_index (pm->plugin_info, p[0]);
	return dlsym (pi->handle, symbol_name);
	}

	static char *
	str_array_to_vec (char *array, int len)
	{
	char c, *r = 0;
	int n = 0;

	do
	{
	c = array[n];
	vec_add1 (r, c);
	}
	while (c && ++n < len);

	if (c)
	vec_add1 (r, 0);

	return r;
	}

	static int
	load_one_plugin (plugin_main_t * pm, plugin_info_t * pi, int from_early_init)
	{
	void *handle;
	clib_error_t *error;
	elf_main_t em = { 0 };
	elf_section_t *section;
	u8 *data;
	char *version_required;
	vlib_plugin_registration_t *reg;
	plugin_config_t *pc = 0;
	uword *p;

	if (elf_read_file (&em, (char *) pi->filename))
	return -1;

	error = elf_get_section_by_name (&em, ".vlib_plugin_registration",
	&section);
	if (error)
	{
	clib_warning ("Not a plugin: %s\n", (char *) pi->name);
	return -1;
	}

	data = elf_get_section_contents (&em, section->index, 1);
	reg = (vlib_plugin_registration_t *) data;

	if (vec_len (data) != sizeof (*reg))
	{
	clib_warning ("vlib_plugin_registration size mismatch in plugin %s\n",
	(char *) pi->name);
	goto error;
	}

	p = hash_get_mem (pm->config_index_by_name, pi->name);
	if (p)
	{
	pc = vec_elt_at_index (pm->configs, p[0]);
	if (pc->is_disabled)
	{
	clib_warning ("Plugin disabled: %s", pi->name);
	goto error;
	}
	if (reg->default_disabled && pc->is_enabled == 0)
	{
	clib_warning ("Plugin disabled (default): %s", pi->name);
	goto error;
	}
	}
	else if (reg->default_disabled)
	{
	clib_warning ("Plugin disabled (default): %s", pi->name);
	goto error;
	}

	version_required = str_array_to_vec ((char *) &reg->version_required,
	sizeof (reg->version_required));

	if ((strlen (version_required) > 0) &&
	(strncmp (vlib_plugin_app_version, version_required,
	strlen (version_required))))
	{
	clib_warning ("Plugin %s version mismatch: %s != %s",
	pi->name, vlib_plugin_app_version, reg->version_required);
	if (!(pc && pc->skip_version_check == 1))
	{
	vec_free (version_required);
	goto error;
	}
	}

	vec_free (version_required);
	vec_free (data);
	elf_main_free (&em);

	handle = dlopen ((char *) pi->filename, RTLD_LAZY);

	if (handle == 0)
	{
	clib_warning ("%s", dlerror ());
	clib_warning ("Failed to load plugin '%s'", pi->name);
	os_exit (1);
	}

	pi->handle = handle;

	reg = dlsym (pi->handle, "vlib_plugin_registration");

	if (reg == 0)
	{
	/* This should never happen unless somebody chagnes registration macro */
	clib_warning ("Missing plugin registration in plugin '%s'", pi->name);
	os_exit (1);
	}

	pi->reg = reg;
	pi->version = str_array_to_vec ((char *) &reg->version,
	sizeof (reg->version));

	if (reg->early_init)
	{
	clib_error_t (ei) (vlib_main_t *);
	void *h;

	h = dlsym (pi->handle, reg->early_init);
	if (h)
	{
	ei = h;
	error = (*ei) (pm->vlib_main);
	if (error)
	{
	clib_error_report (error);
	os_exit (1);
	}
	}
	else
	clib_warning ("Plugin %s: early init function %s set but not found",
	(char *) pi->name, reg->early_init);
	}

	if (reg->description)
	clib_warning ("Loaded plugin: %s (%s)", pi->name, reg->description);
	else
	clib_warning ("Loaded plugin: %s", pi->name);

	return 0;
	error:
	vec_free (data);
	elf_main_free (&em);
	return -1;
	}

	static u8 **
	split_plugin_path (plugin_main_t * pm)
	{
	int i;
	u8 **rv = 0;
	u8 *path = pm->plugin_path;
	u8 *this = 0;

	for (i = 0; i < vec_len (pm->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;
	}

	static int
	plugin_name_sort_cmp (void a1, void a2)
	{
	plugin_info_t *p1 = a1;
	plugin_info_t *p2 = a2;

	return strcmp ((char ) p1->name, (char ) p2->name);
	}

	int
	vlib_load_new_plugins (plugin_main_t * pm, int from_early_init)
	{
	DIR *dp;
	struct dirent *entry;
	struct stat statb;
	uword *p;
	plugin_info_t *pi;
	u8 **plugin_path;
	u32 *load_fail_indices = 0;
	int i;

	plugin_path = split_plugin_path (pm);

	for (i = 0; i < vec_len (plugin_path); i++)
	{
	dp = opendir ((char *) plugin_path[i]);

	if (dp == 0)
	continue;

	while ((entry = readdir (dp)))
	{
	u8 *plugin_name;
	u8 *filename;

	if (pm->plugin_name_filter)
	{
	int j;
	for (j = 0; j < vec_len (pm->plugin_name_filter); j++)
	if (entry->d_name[j] != pm->plugin_name_filter[j])
	goto next;
	}

	filename = format (0, "%s/%s%c", plugin_path[i], entry->d_name, 0);

	/* Only accept .so */
	char ext = strrchr ((const char ) filename, '.');
	/* unreadable */
	if (!ext \|\| (strcmp (ext, ".so") != 0) \|\|
	stat ((char *) filename, &statb) < 0)
	{
	ignore:
	vec_free (filename);
	continue;
	}

	/* a dir or other things which aren't plugins */
	if (!S_ISREG (statb.st_mode))
	goto ignore;

	plugin_name = format (0, "%s%c", entry->d_name, 0);
	/* Have we seen this plugin already? */
	p = hash_get_mem (pm->plugin_by_name_hash, plugin_name);
	if (p == 0)
	{
	/* No, add it to the plugin vector */
	vec_add2 (pm->plugin_info, pi, 1);
	pi->name = plugin_name;
	pi->filename = filename;
	pi->file_info = statb;
	hash_set_mem (pm->plugin_by_name_hash, plugin_name,
	pi - pm->plugin_info);
	}
	next:
	;
	}
	closedir (dp);
	vec_free (plugin_path[i]);
	}
	vec_free (plugin_path);


	/*
	* Sort the plugins by name. This is important.
	* API traces contain absolute message numbers.
	* Loading plugins in directory (vs. alphabetical) order
	* makes trace replay incredibly fragile.
	*/
	vec_sort_with_function (pm->plugin_info, plugin_name_sort_cmp);

	/*
	* Attempt to load the plugins
	*/
	for (i = 0; i < vec_len (pm->plugin_info); i++)
	{
	pi = vec_elt_at_index (pm->plugin_info, i);

	if (load_one_plugin (pm, pi, from_early_init))
	{
	/* Make a note of any which fail to load */
	vec_add1 (load_fail_indices, i);
	hash_unset_mem (pm->plugin_by_name_hash, pi->name);
	vec_free (pi->name);
	vec_free (pi->filename);
	}
	}

	/* Remove plugin info vector elements corresponding to load failures */
	if (vec_len (load_fail_indices) > 0)
	{
	for (i = vec_len (load_fail_indices) - 1; i >= 0; i--)
	vec_delete (pm->plugin_info, 1, load_fail_indices[i]);
	vec_free (load_fail_indices);
	}

	/* Recreate the plugin name hash */
	for (i = 0; i < vec_len (pm->plugin_info); i++)
	{
	pi = vec_elt_at_index (pm->plugin_info, i);
	hash_unset_mem (pm->plugin_by_name_hash, pi->name);
	hash_set_mem (pm->plugin_by_name_hash, pi->name, pi - pm->plugin_info);
	}

	return 0;
	}

	int
	vlib_plugin_early_init (vlib_main_t * vm)
	{
	plugin_main_t *pm = &vlib_plugin_main;

	if (pm->plugin_path == 0)
	pm->plugin_path = format (0, "%s%c", vlib_plugin_path, 0);

	clib_warning ("plugin path %s", pm->plugin_path);

	pm->plugin_by_name_hash = hash_create_string (0, sizeof (uword));
	pm->vlib_main = vm;

	return vlib_load_new_plugins (pm, 1 /* from_early_init */ );
	}

	static clib_error_t *
	vlib_plugins_show_cmd_fn (vlib_main_t * vm,
	unformat_input_t * input, vlib_cli_command_t * cmd)
	{
	plugin_main_t *pm = &vlib_plugin_main;
	u8 *s = 0;
	u8 *key = 0;
	uword value = 0;
	int index = 1;
	plugin_info_t *pi;

	s = format (s, " Plugin path is: %s\n\n", pm->plugin_path);
	s = format (s, " %-41s%-33s%s\n", "Plugin", "Version", "Description");

	/* INDENT-OFF */
	hash_foreach_mem (key, value, pm->plugin_by_name_hash,
	{
	if (key != 0)
	{
	pi = vec_elt_at_index (pm->plugin_info, value);
	s = format (s, "%3d. %-40s %-32s %s\n", index, key, pi->version,
	pi->reg->description ? pi->reg->description : "");
	index++;
	}
	});
	/* INDENT-ON */

	vlib_cli_output (vm, "%v", s);
	vec_free (s);
	return 0;
	}

	/* INDENT-OFF */
	VLIB_CLI_COMMAND (plugins_show_cmd, static) =
	{
	.path = "show plugins",
	.short_help = "show loaded plugins",
	.function = vlib_plugins_show_cmd_fn,
	};
	/* INDENT-ON */

	static clib_error_t *
	config_one_plugin (vlib_main_t * vm, char name, unformat_input_t input)
	{
	plugin_main_t *pm = &vlib_plugin_main;
	plugin_config_t *pc;
	clib_error_t *error = 0;
	uword *p;
	int is_enable = 0;
	int is_disable = 0;
	int skip_version_check = 0;

	if (pm->config_index_by_name == 0)
	pm->config_index_by_name = hash_create_string (0, sizeof (uword));

	p = hash_get_mem (pm->config_index_by_name, name);

	if (p)
	{
	error = clib_error_return (0, "plugin '%s' already configured", name);
	goto done;
	}

	while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
	{
	if (unformat (input, "enable"))
	is_enable = 1;
	else if (unformat (input, "disable"))
	is_disable = 1;
	else if (unformat (input, "skip-version-check"))
	skip_version_check = 1;
	else
	{
	error = clib_error_return (0, "unknown input '%U'",
	format_unformat_error, input);
	goto done;
	}
	}

	if (is_enable && is_disable)
	{
	error = clib_error_return (0, "please specify either enable or disable"
	" for plugin '%s'", name);
	goto done;
	}

	vec_add2 (pm->configs, pc, 1);
	hash_set_mem (pm->config_index_by_name, name, pc - pm->configs);
	pc->is_enabled = is_enable;
	pc->is_disabled = is_disable;
	pc->skip_version_check = skip_version_check;
	pc->name = name;

	done:
	return error;
	}

	clib_error_t *
	vlib_plugin_config (vlib_main_t * vm, unformat_input_t * input)
	{
	plugin_main_t *pm = &vlib_plugin_main;
	clib_error_t *error = 0;
	unformat_input_t in;

	unformat_init (&in, 0, 0);

	while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
	{
	u8 s, v;
	if (unformat (input, "%s %v", &s, &v))
	{
	if (strncmp ((const char *) s, "plugins", 8) == 0)
	{
	if (vec_len (in.buffer) > 0)
	vec_add1 (in.buffer, ' ');
	vec_add (in.buffer, v, vec_len (v));
	}
	}
	else
	{
	error = clib_error_return (0, "unknown input '%U'",
	format_unformat_error, input);
	goto done;
	}

	vec_free (v);
	vec_free (s);
	}
	done:
	input = &in;
	while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
	{
	unformat_input_t sub_input;
	u8 *s = 0;
	if (unformat (input, "path %s", &s))
	pm->plugin_path = s;
	else if (unformat (input, "plugin %s %U", &s,
	unformat_vlib_cli_sub_input, &sub_input))
	{
	error = config_one_plugin (vm, (char *) s, &sub_input);
	unformat_free (&sub_input);
	if (error)
	goto done2;
	}
	else
	{
	error = clib_error_return (0, "unknown input '%U'",
	format_unformat_error, input);
	{
	vec_free (s);
	goto done2;
	}
	}
	}

	done2:
	unformat_free (&in);
	return error;
	}

	/* discard whole 'plugins' section, as it is already consumed prior to
	plugin load */
	static clib_error_t *
	plugins_config (vlib_main_t * vm, unformat_input_t * input)
	{
	u8 *junk;

	while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
	{
	if (unformat (input, "%s", &junk))
	{
	vec_free (junk);
	return 0;
	}
	else
	return clib_error_return (0, "unknown input '%U'",
	format_unformat_error, input);
	}
	return 0;
	}

	VLIB_CONFIG_FUNCTION (plugins_config, "plugins");

	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/