plugin.c File Reference

Methods to access plugins. More...

#include "platform.h"
#include <ltdl.h>
#include "gnunet_util_lib.h"

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Go to the source code of this file.

Data Structures
struct	PluginList
	Linked list of active plugins. More...
struct	LoadAllContext
	Closure for find_libraries(). More...

Macros
#define	LOG(kind, ...)   GNUNET_log_from (kind, "util-plugin", __VA_ARGS__)

Functions
static void	plugin_init (void)
	Setup libtool paths. More...
static void	plugin_fini (void)
	Shutdown libtool. More...
static GNUNET_PLUGIN_Callback	resolve_function (struct PluginList *plug, const char *name)
	Lookup a function in the plugin. More...
enum GNUNET_GenericReturnValue	GNUNET_PLUGIN_test (const char *library_name)
	Test if a plugin exists. More...
void *	GNUNET_PLUGIN_load (const char *library_name, void *arg)
	Setup plugin (runs the "init" callback and returns whatever "init" returned). More...
void *	GNUNET_PLUGIN_unload (const char *library_name, void *arg)
	Unload plugin (runs the "done" callback and returns whatever "done" returned). More...
static int	find_libraries (void *cls, const char *filename)
	Function called on each plugin in the directory. More...
void	GNUNET_PLUGIN_load_all (const char *basename, void *arg, GNUNET_PLUGIN_LoaderCallback cb, void *cb_cls)
	Load all compatible plugins with the given base name. More...
void	GNUNET_PLUGIN_load_all_in_context (const struct GNUNET_OS_ProjectData *ctx, const char *basename, void *arg, GNUNET_PLUGIN_LoaderCallback cb, void *cb_cls)
	Load all compatible plugins with the given base name while inside the given context (i.e. More...

Variables
static int	initialized
	Have we been initialized? More...
static char *	old_dlsearchpath
	Libtool search path before we started. More...
static struct PluginList *	plugins
	List of plugins we have loaded. More...

Detailed Description

Methods to access plugins.

Author

Christian Grothoff

Definition in file plugin.c.

Macro Definition Documentation

LOG

#define LOG	(		kind,
			...
	)		GNUNET_log_from (kind, "util-plugin", __VA_ARGS__)

Definition at line 32 of file plugin.c.

Function Documentation

plugin_init()

static void plugin_init ( void  )

static

Setup libtool paths.

Definition at line 76 of file plugin.c.

{
  int err;
  const char *opath;
  char *path;
  char *cpath;
 
  err = lt_dlinit ();
  if (err > 0)
  {
    fprintf (stderr,
             _ ("Initialization of plugin mechanism failed: %s!\n"),
             lt_dlerror ());
    return;
  }
  opath = lt_dlgetsearchpath ();
  if (NULL != opath)
    old_dlsearchpath = GNUNET_strdup (opath);
  path = GNUNET_OS_installation_get_path (GNUNET_OS_IPK_LIBDIR);
  if (NULL != path)
  {
    if (NULL != opath)
    {
      GNUNET_asprintf (&cpath,
                       "%s:%s",
                       opath,
                       path);
      lt_dlsetsearchpath (cpath);
      GNUNET_free (path);
      GNUNET_free (cpath);
    }
    else
    {
      lt_dlsetsearchpath (path);
      GNUNET_free (path);
    }
  }
}

References _, GNUNET_asprintf(), GNUNET_free, GNUNET_OS_installation_get_path(), GNUNET_OS_IPK_LIBDIR, GNUNET_strdup, and old_dlsearchpath.

Referenced by GNUNET_PLUGIN_load().

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plugin_fini()

static void plugin_fini ( void  )

static

Shutdown libtool.

Definition at line 120 of file plugin.c.

{
  lt_dlsetsearchpath (old_dlsearchpath);
  if (NULL != old_dlsearchpath)
  {
    GNUNET_free (old_dlsearchpath);
    old_dlsearchpath = NULL;
  }
  if (NULL == getenv ("VALGRINDING_PLUGINS"))
    lt_dlexit ();
}

References getenv(), GNUNET_free, and old_dlsearchpath.

Referenced by GNUNET_PLUGIN_unload().

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resolve_function()

static GNUNET_PLUGIN_Callback resolve_function ( struct PluginList *  plug, const char *  name  )

static

Lookup a function in the plugin.

Parameters

plug	the plugin to check
name	name of the symbol to look for

Returns

NULL if the symbol was not found

Definition at line 141 of file plugin.c.

{
  char *initName;
  void *mptr;
 
  GNUNET_asprintf (&initName,
                   "_%s_%s",
                   plug->name,
                   name);
  mptr = lt_dlsym (plug->handle,
                   &initName[1]);
  if (NULL == mptr)
    mptr = lt_dlsym (plug->handle,
                     initName);
  if (NULL == mptr)
    LOG (GNUNET_ERROR_TYPE_ERROR,
         _ ("`%s' failed to resolve method '%s' with error: %s\n"),
         "lt_dlsym",
         &initName[1],
         lt_dlerror ());
  GNUNET_free (initName);
  return mptr;
}

Referenced by GNUNET_PLUGIN_load(), and GNUNET_PLUGIN_unload().

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find_libraries()

static int find_libraries ( void *  cls, const char *  filename  )

static

Function called on each plugin in the directory.

Loads the plugins that match the given basename.

Parameters

cls	the struct LoadAllContext describing which plugins to load and what to do with them
filename	name of a plugin library to check

Returns

GNUNET_OK (continue loading)

Definition at line 321 of file plugin.c.

{
  struct LoadAllContext *lac = cls;
  const char *slashpos;
  const char *libname;
  char *basename;
  char *dot;
  void *lib_ret;
  size_t n;
 
  libname = filename;
  while (NULL != (slashpos = strstr (libname,
                                     DIR_SEPARATOR_STR)))
    libname = slashpos + 1;
  n = strlen (libname);
  if (0 != strncmp (lac->basename,
                    libname,
                    strlen (lac->basename)))
    return GNUNET_OK; /* wrong name */
  if ( (n > 3) &&
       (0 == strcmp (&libname[n - 3], ".la")) )
    return GNUNET_OK; /* .la file */
  basename = GNUNET_strdup (libname);
  if (NULL != (dot = strstr (basename, ".")))
    *dot = '\0';
  lib_ret = GNUNET_PLUGIN_load (basename,
                                lac->arg);
  if (NULL != lib_ret)
    lac->cb (lac->cb_cls,
             basename,
             lib_ret);
  GNUNET_free (basename);
  return GNUNET_OK;
}

References LoadAllContext::arg, LoadAllContext::basename, LoadAllContext::cb, LoadAllContext::cb_cls, DIR_SEPARATOR_STR, filename, GNUNET_free, GNUNET_OK, GNUNET_PLUGIN_load(), and GNUNET_strdup.

Referenced by GNUNET_PLUGIN_load_all().

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Variable Documentation

initialized

int initialized

static

Have we been initialized?

Definition at line 59 of file plugin.c.

Referenced by GNUNET_PLUGIN_load(), and GNUNET_PLUGIN_unload().

old_dlsearchpath

char* old_dlsearchpath

static

Libtool search path before we started.

Definition at line 64 of file plugin.c.

Referenced by plugin_fini(), and plugin_init().

plugins

struct PluginList* plugins

static

List of plugins we have loaded.

Definition at line 69 of file plugin.c.

Referenced by extract_files(), GNUNET_PLUGIN_load(), GNUNET_PLUGIN_unload(), and main().