/***************************************************************************
 *   Copyright (C) 03/2005 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 <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <sys/ioctl.h>
#include <pthread.h>
#include <semaphore.h>
#include <time.h>
#include <inttypes.h>

#include "list.h"
#include "netpkt.h"
#include "configfile.h"
#include "hlswmaster.h"
#include "plugin.h"
#include "plugin_helper.h"

#define DEBUG 1

struct rx_entry {
	struct list_head list;
	struct net_pkt *pkt;
};

/** rx packet liste */
static LIST_HEAD(rxlist);

/** sichert die rx liste */
static pthread_mutex_t rxlist_lock = PTHREAD_MUTEX_INITIALIZER;

/** anzahl der pakete in der rxlist */
static sem_t rxlist_sem;

/** interne serverliste */
static LIST_HEAD(serverlist);

/** sichert die interne serverliste */
static pthread_mutex_t serverlist_lock = PTHREAD_MUTEX_INITIALIZER;

/** scan socket */
static int scan_sock;

/**
 * server_cmp()
 * LIST_FIND helper
 *
 * @param *a gameserver 1
 * @param *b gameserver 2
 * @return true wenn es sich um den selben server handelt
 */
static inline int server_cmp(const struct game_server *a, struct game_server *b)
{
	return (a->gameid == b->gameid && a->ip == b->ip &&
		a->port1 == b->port1 && a->port2 == b->port2);
}

/**
 * server_add()
 * wenn der server noch nicht in der internen liste vorhanden ist
 * wird er hinzugefuegt, ansonsten nur die modtime angepasst
 *
 * @param gameid gameid des servers
 * @param ip ip des servers
 * @param port1 erster port
 * @param port2 zweiter port
 * @return false bei fehler
 */
int server_add(uint16_t gameid, uint32_t ip, uint16_t port1, uint16_t port2)
{
	struct game_server server, *nserver;

	server.gameid = gameid;
	server.ip = ip;
	server.port1 = port1;
	server.port2 = port2;

	pthread_mutex_lock(&serverlist_lock);

	/* diesen server in der liste suchen */
	nserver = LIST_FIND(&serverlist, server_cmp, struct game_server *, &server);
	if (!nserver) {
		/* neuen eintrag anlegen */
		if (!(nserver = malloc(sizeof(struct game_server)))) {
			pthread_mutex_unlock(&serverlist_lock);
			log_print("server_add(): malloc()");
			return 0;
		}
#ifdef DEBUG
		{
		struct in_addr tmp;
		tmp.s_addr = server.ip;
		printf("server_add_new: gameid=%2d ip=%15s port1=%5d port2=%5d\n",
			server.gameid, inet_ntoa(tmp), server.port1, server.port2);
		}
#endif
		memcpy(nserver, &server, sizeof(struct game_server));
		list_add_tail(&nserver->list, &serverlist);
	}

	/* modtime anpassen */
	nserver->modtime = time(NULL);

	pthread_mutex_unlock(&serverlist_lock);
	return 1;
}

/**
 * serverlist_refresh()
 * loescht alte server aus der liste
 * baut aus den verbleibenden die client_liste auf
 *
 * @param timeout timeout in sekunden
 */
static void serverlist_refresh(long timeout)
{
	struct game_server *server, *tmp;
	long now = time(NULL);

	pthread_mutex_lock(&serverlist_lock);
	list_for_each_entry_safe(server, tmp, &serverlist, list) {
		if ((server->modtime + timeout) < now) {
#ifdef DEBUG
			{
			struct in_addr tmp2;
			tmp2.s_addr = server->ip;
			printf("server timeout: gameid=%2d ip=%15s port1=%5d port2=%5d\n",
				server->gameid, inet_ntoa(tmp2), server->port1, server->port2);
			}
#endif
			list_del(&server->list);
			free(server);

		} else {
			client_pkt_add(server);
		}
	}
	pthread_mutex_unlock(&serverlist_lock);

	client_pkt_commit();
}

/**
 * pkt_send()
 * schickt ein paket ab
 *
 * @param *dstip destination IP, wenn NULL wird broadcast angenommen
 * @param dstport destination port
 * @param *buf datenbereich der gesendet wird
 * @param size groesse der daten
 * @return false bei fehler
 */
int pkt_send(struct in_addr *dstip, unsigned int dstport, char *buf, unsigned int size)
{
	struct sockaddr_in addr;
	int ret = 1;

	addr.sin_family = AF_INET;
	addr.sin_port = htons(dstport);
	addr.sin_addr.s_addr = (dstip ? dstip->s_addr : 0xFFFFFFFF);

	if (sendto(scan_sock, buf, size, 0, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
		log_print("scan_send(): sendto()");
		ret = 0;
	}

	usleep(10000);
	return ret;
}

/**
 * scan_receive_real()
 * arbeitet die receive queue ab
 */
void scan_receive_real(void)
{
	struct rx_entry *rx;
	struct net_pkt *pkt;
	int cnt, retval;

	do {
		sem_wait(&rxlist_sem);
		
		pthread_mutex_lock(&rxlist_lock);
		rx = list_entry(rxlist.next, struct rx_entry, list);
		list_del(&rx->list);
		pthread_mutex_unlock(&rxlist_lock);

		pkt = rx->pkt;
		free(rx);
		
		retval = plugins_parse(pkt);

		switch (retval) {
		case PARSE_REJECT:
			log_print("scan_receive(): unknown packet: %s:%d size:%d",
				inet_ntoa(pkt->addr.sin_addr),
				ntohs(pkt->addr.sin_port),
				pkt->size);
#if 0
			{
			char *p = pkt_print(pkt);
			log_print("%s", p);
			free(p);
			}
#endif

		case PARSE_ACCEPT:
			free(pkt);

		case PARSE_ACCEPT_FREED:
			break;
		}

		sem_getvalue(&rxlist_sem, &cnt);
	} while (cnt > 0);
	
}

/**
 * scan_control()
 * triggert den gc der plugins
 * triggert den serverlist_refresh
 * triggert den scan der plugins
 * arbeitet die rx queue ab
 */
void scan_control(void)
{
	long last_plugin_gc = 0, last_list_refresh = 0, last_scan = 0;
	int plugin_timeout, list_timeout, list_refresh, scan_interval;
	int cnt;
	long now;
	
	plugin_timeout = config_get_int("global", "plugin_timeout", 30);
	list_timeout = config_get_int("global", "serverlist_timeout", 30);
	list_refresh = config_get_int("global", "serverlist_refresh", 5);
	scan_interval = config_get_int("global", "scan_interval", 30);

	log_print("thread_start: scan_control");
	log_print(" scan_interval: %ds", scan_interval);
	log_print(" serverlist_refresh: %ds", list_refresh);
	log_print(" serverlist_timeout: %ds", list_timeout);
	log_print(" plugin_timeout: %d", plugin_timeout);

	while (1) {
		now = time(NULL);

		/* interne plugin daten aufraeumen */
		if (last_plugin_gc + plugin_timeout < now) {
			last_plugin_gc = now;
			plugins_gc(plugin_timeout);
		}

		/* server liste aufraeumen, und neue client pkts erzeugen */
		if (last_list_refresh + list_refresh < now) {
			last_list_refresh = now;
			serverlist_refresh(list_timeout);
		}

		/* neuen scan ausloesen */
		if (last_scan + scan_interval < now) {
			last_scan = now;
			plugins_scan();
		}

		/* empfangene daten parsen */
		sem_getvalue(&rxlist_sem, &cnt);
		if (cnt > 0)
			scan_receive_real();

		usleep(500000);
	}
}

/**
 * scan_receive()
 * wartet auf serverantworten und uebergibt die pakete der
 * receive queue
 */
void scan_receive(void)
{
	struct net_pkt *pkt;
	struct rx_entry *rx;
	fd_set fdsel, fdcpy;
	int recvsize, i;

	log_print("thread_start: scan_receiver");

	FD_ZERO(&fdsel);
	FD_SET(scan_sock, &fdsel);

	while (1) {
		memcpy(&fdcpy, &fdsel, sizeof(fdsel));
		select(FD_SETSIZE, &fdcpy, NULL, NULL, NULL);

		if (ioctl(scan_sock, FIONREAD, &recvsize) == -1) {
			log_print("scan_receive(): ioctl()");
			continue;
		}

		if (!(pkt = malloc(sizeof(struct net_pkt) + recvsize))) {
			log_print("scan_receive(): malloc()");
			continue;
		}

		i = sizeof(struct sockaddr_in);
		pkt->size = recvfrom(scan_sock, pkt->buf, recvsize, 0, (struct sockaddr *)&pkt->addr, &i);

		if (pkt->size == 0) {
			free(pkt);
			continue;
		}

		rx = malloc(sizeof(struct rx_entry));
		rx->pkt = pkt;
		
		pthread_mutex_lock(&rxlist_lock);
		list_add_tail(&rx->list, &rxlist);
		pthread_mutex_unlock(&rxlist_lock);
	
		sem_post(&rxlist_sem);
	}
}

/**
 * schliesst den server scan socket
 */
static void scan_close()
{
	close(scan_sock);
	sem_destroy(&rxlist_sem);
}

/**
 * scan_init()
 * initialisiert den socket fuer den server scan
 * initialisiert die rxlist semaphore
 *
 * @return false on error
 */
int scan_init()
{
	struct sockaddr_in dst;
	int i = 1, port;
	char *ip;

	if ((scan_sock = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
		log_print("scan_init(): socket()");
		return 0;
	}

	ip = config_get_string("global", "scan_ip", "0.0.0.0");
	port = config_get_int("global", "scan_port", 7130);

	dst.sin_family = AF_INET;
	dst.sin_port = htons(port);
	inet_aton(ip, &dst.sin_addr);

	if (bind(scan_sock, (struct sockaddr *)&dst, sizeof(dst)) < 0) {
		log_print("scan_init(): bind()");
		return 0;
	}

	if (setsockopt(scan_sock, SOL_SOCKET, SO_BROADCAST, &i, sizeof(i))) {
		log_print("scan_init(): setsockopt()");
		return 0;
	}

	if (atexit(scan_close) != 0) {
		log_print("scan_init(): atexit()");
		return 0;
	}

	log_print("scan socket initialized (%s:%d)", ip, port);
	
	sem_init(&rxlist_sem, 0, 0);

	return 1;
}