/***************************************************************************
 *   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 "list.h"
#include "netpkt.h"
#include "configfile.h"
#include "hlswmaster.h"

LIST_HEAD(send_queue);

static int scan_sock;

/**
 * pkt_queue()
 * packt ein paket in die sender queue
 * @param struct net_pkt *pkt
 */
void pkt_queue(struct net_pkt *pkt) {
	list_add_tail(&pkt->list, &send_queue);
}

/**
 * scan_transmit()
 * triggert den scan der plugins
 * arbeitet die sender queue ab
 *
 * TODO: ratelimiting
 */
void scan_transmit(void) {
	struct net_pkt *pkt, *tmp;
	int interval;

	interval = config_get_int("global", "scan_interval", 30);
	log_print("starting tx scan thread (%ds interval)", interval);
	
	while (1) {
		plugins_scan();

		list_for_each_entry_safe(pkt, tmp, &send_queue, list) {
			if (sendto(scan_sock, pkt->buf, pkt->size, 0, (struct sockaddr *)&pkt->addr, sizeof(pkt->addr)) < 0)
				log_print("scan_transmit(): sendto()");

			list_del(&pkt->list);
			free(pkt);
			usleep(10000);
		}

		sleep(interval);
	}
}

/**
 * scan_receive()
 * wartet auf serverantworten und uebergibt die pakete den
 * plugins zur auswertung
 */
void scan_receive(void) {
	struct net_pkt *pkt;
	fd_set fdsel, fdcpy;
	int recvsize, i;

	log_print("starting rx scan thread");
	
	FD_ZERO(&fdsel);
	FD_SET(scan_sock, &fdsel);

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

		ioctl(scan_sock, FIONREAD, &recvsize);

		if (recvsize <= 0) {
			log_print("scan_receive(): drop short packet");
			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 (!plugins_parse(pkt)) {
			log_print("scan_receive(): unknown packet: %s:%d size:%d",
			    inet_ntoa(pkt->addr.sin_addr), ntohs(pkt->addr.sin_port), pkt->size);
		}
		
		free(pkt);
	}
}

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

/**
 * scan_init()
 * initialisiert den socket fuer den server scan
 * @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);
	return 1;
}