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/* fuse-overlayfs: Overlay Filesystem in Userspace
Copyright (C) 2019 Red Hat Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#define _GNU_SOURCE
#define _FILE_OFFSET_BITS 64
#include <config.h>
#include <plugin.h>
#include <stdlib.h>
#include <fuse_overlayfs_error.h>
#include <errno.h>
#include <string.h>
struct ovl_plugin_context *
load_plugins (const char *plugins)
{
char *saveptr = NULL, *it;
cleanup_free char *buf = NULL;
struct ovl_plugin_context *ctx;
ctx = calloc (1, sizeof (*ctx));
if (ctx == NULL)
error (EXIT_FAILURE, errno, "cannot allocate context");
buf = strdup (plugins);
if (buf == NULL)
error (EXIT_FAILURE, errno, "cannot allocate memory");
for (it = strtok_r (buf, ":", &saveptr); it; it = strtok_r (NULL, ":", &saveptr))
plugin_load_one (ctx, it);
return ctx;
}
void
plugin_load_one (struct ovl_plugin_context *context, const char *path)
{
plugin_name name;
struct ovl_plugin *p;
plugin_version version;
void *handle = dlopen (path, RTLD_NOW | RTLD_LOCAL);
if (! handle)
error (EXIT_FAILURE, 0, "cannot load plugin %s: %s", path, dlerror ());
p = calloc (1, sizeof (*p));
if (p == NULL)
error (EXIT_FAILURE, errno, "cannot load plugin %s", path);
p->next = context->plugins;
version = dlsym (handle, "plugin_version");
if (version == NULL)
error (EXIT_FAILURE, 0, "cannot find symbol `plugin_version` in plugin %s", path);
if (version () != 1)
error (EXIT_FAILURE, 0, "invalid plugin version for %s", path);
p->handle = handle;
name = dlsym (handle, "plugin_name");
if (name == NULL)
error (EXIT_FAILURE, 0, "cannot find symbol `plugin_name` in plugin %s", path);
p->name = name ();
if (plugin_find (context, p->name))
error (EXIT_FAILURE, 0, "plugin %s added twice", p->name);
p->load = dlsym (handle, "plugin_load");
if (p->load == NULL)
error (EXIT_FAILURE, 0, "cannot find symbol `plugin_load` in plugin %s", path);
p->release = dlsym (handle, "plugin_release");
if (p->release == NULL)
error (EXIT_FAILURE, 0, "cannot find symbol `plugin_release` in plugin %s", path);
context->plugins = p;
}
struct ovl_plugin *
plugin_find (struct ovl_plugin_context *context, const char *name)
{
struct ovl_plugin *it;
for (it = context->plugins; it; it = it->next)
{
if (strcmp (name, it->name) == 0)
return it;
}
return NULL;
}
int
plugin_free_all (struct ovl_plugin_context *context)
{
struct ovl_plugin *it, *next;
it = context->plugins;
while (it)
{
next = it->next;
it->release ();
/* Skip dlclose (it->handle) as it causes plugins written in Go to crash. */
free (it);
it = next;
}
free (context);
return 0;
}
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