sammler/plugins.c

/***************************************************************************
 *   Copyright (C) 06/2006 by Olaf Rempel                                  *
 *   razzor@kopf-tisch.de                                                  *
 *                                                                         *
 *   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, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#include <stdio.h>
#include <string.h>
#include <dlfcn.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <time.h>
#include <limits.h>

#include "list.h"

#include "plugins.h"
#include "configfile.h"
#include "event.h"
#include "logging.h"
#include "network.h"
#include "rrdtool.h"

#define BUFSIZE 512

#define SUBMIT_NET_ONLY	0x01

static LIST_HEAD(plugin_list);

static int submit_flags;

static char *scratchpad;

static int plugin_init_cb(const char *filename, void *privdata)
{
	int *bufsize = (int *)privdata;

	static const char *plugin_dir;
	if (plugin_dir == NULL)
		plugin_dir = config_get_string("global", "plugin_dir", ".");

	char *buffer = malloc(PATH_MAX);
	if (buffer == NULL) {
		log_print(LOG_ERROR, "plugin_load: out of memory");
		return -1;
	}

	int len = snprintf(buffer, PATH_MAX, "%s/%s", plugin_dir, filename);
	if (len < 0 || len >= PATH_MAX) {
		log_print(LOG_ERROR, "plugin_load: file name too long: %s/%s", plugin_dir, filename);
		free(buffer);
		return -1;
	}

	dlerror();
	void *tmp = dlopen(buffer, RTLD_NOW);
	if (tmp == NULL) {
		log_print(LOG_ERROR, "plugin_load: dlopen: %s", dlerror());
		free(buffer);
		return -1;
	}

	free(buffer);

	struct sammler_plugin *plugin = dlsym(tmp, "plugin");
	if (plugin == NULL) {
		log_print(LOG_ERROR, "plugin_load: failed to load '%s'", filename);
		dlclose(tmp);
		return -1;
	}

	log_print(LOG_INFO, "Plugin '%s' loaded", plugin->name);
	plugin->lastprobe = 0;

	if (plugin->init != NULL && (plugin->init() != 0)) {
		log_print(LOG_ERROR, "Plugin '%s': init failed", plugin->name);
		return -1;
	}

	if (plugin->bufsize > *bufsize)
		*bufsize = plugin->bufsize;

	list_add_tail(&plugin->list, &plugin_list);
	return 0;
}

static int plugins_probe(void *privdata)
{
	time_t now;
	time(&now);

	struct sammler_plugin *plugin;
	list_for_each_entry(plugin, &plugin_list, list) {
		if (plugin->lastprobe + plugin->interval <= now) {
			plugin->probe();
			plugin->lastprobe = now;
		}
	}

	net_submit_flush();
	return 0;
}

int plugin_init(void)
{
	int bufsize = 0;
	config_get_strings("global", "plugin", plugin_init_cb, &bufsize);

	scratchpad = malloc(bufsize);
	if (scratchpad == NULL) {
		log_print(LOG_ERROR, "plugin_init: out of memory");
		return -1;
	}

	struct sammler_plugin *plugin;
	list_for_each_entry(plugin, &plugin_list, list)
		plugin->buffer = scratchpad;

	const char *fwd_only = config_get_string("global", "forward_only", NULL);
	if (fwd_only == NULL || strncmp(fwd_only, "true", 4))
		submit_flags |= SUBMIT_NET_ONLY;

	struct timeval tv;
	tv.tv_sec = 1;
	tv.tv_usec = 0;
	event_add_timeout(&tv, plugins_probe, NULL);

	return 0;
}

struct sammler_plugin * plugin_lookup(const char *name)
{
	struct sammler_plugin *plugin;
	list_for_each_entry(plugin, &plugin_list, list) {
		if (!strcmp(plugin->name, name))
			return plugin;
	}
	return NULL;
}

int probe_submit(struct sammler_plugin *plugin, const char *filename, int ds_id, const char *fmt, ... )
{
	static const char *hostname = NULL;
	if (hostname == NULL)
		hostname = config_get_string("global", "hostname", "localhost");

	char *buffer = malloc(BUFSIZE);
	if (buffer == NULL) {
		log_print(LOG_ERROR, "probe_submit: out of memory");
		return -1;
	}

	va_list az;
	va_start(az, fmt);
	int len = vsnprintf(buffer, BUFSIZE, fmt, az);
	va_end(az);

	if (len < 0 || len >= BUFSIZE) {
		log_print(LOG_ERROR, "probe_submit: %s arguments too long", plugin->name);
		free(buffer);
		return -1;
	}

	net_submit(hostname, plugin, filename, ds_id, buffer);

	if (!(submit_flags & SUBMIT_NET_ONLY))
		rrd_submit(hostname, plugin, filename, ds_id, buffer);

	free(buffer);
	return 0;
}