/* mcast_stream.c
 *
 * Copyright 2006, Iskratel , Slovenia
 * By Jakob Bratkovic <j.bratkovic@iskratel.si> and 
 * Miha Jemec <m.jemec@iskratel.si>
 *
 * based on rtp_stream.c
 * Copyright 2003, Alcatel Business Systems
 * By Lars Ruoff <lars.ruoff@gmx.net>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * 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.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "mcast_stream.h"
#include "mcast_stream_dlg.h"

#include "globals.h"

#include <epan/tap.h>
#include "register.h"

#include "alert_box.h"
#include "simple_dialog.h"
#include "file_util.h"
#include <time.h>

#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif

#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif

#include <string.h>
#include <epan/addr_resolv.h>

gint32 trigger=50; /* limit for triggering the burst alarm (in packets per second) */
gint32 bufferalarm = 10000; /* limit for triggernig the buffer alarm (in bytes) */
guint16 burstint = 100; /* burts interval in ms */
gint32 emptyspeed = 5000; /* outgoing speed for single stream (kbps)*/
gint32 cumulemptyspeed = 100000; /* outgoiong speed for all streams (kbps)*/

t_buffer **bufflist;

/* sliding window and buffer usage */
gint32 buffsize = (int)((double)MAX_SPEED * 100 / 1000) * 2;
guint16 comparetimes(struct timeval *t1, struct timeval *t2, guint16 burstint);
static void buffusagecalc(mcast_stream_info_t *strinfo, packet_info *pinfo, double emptyspeed);
static void slidingwindow(mcast_stream_info_t *strinfo, packet_info *pinfo);


/****************************************************************************/
/* the one and only global mcaststream_tapinfo_t structure */
static mcaststream_tapinfo_t the_tapinfo_struct =
	{0, NULL, 0, NULL, 0, FALSE};


/****************************************************************************/
/* GCompareFunc style comparison function for _mcast_stream_info */
static gint mcast_stream_info_cmp(gconstpointer aa, gconstpointer bb)
{
	const struct _mcast_stream_info* a = aa;
	const struct _mcast_stream_info* b = bb;

        if (a==b)
                return 0;
        if (a==NULL || b==NULL)
                return 1;
        if (ADDRESSES_EQUAL(&(a->src_addr), &(b->src_addr))
                && (a->src_port == b->src_port)
                && ADDRESSES_EQUAL(&(a->dest_addr), &(b->dest_addr))
                && (a->dest_port == b->dest_port))
                return 0;
        else
                return 1;

}


/****************************************************************************/
/* when there is a [re]reading of packet's */
void mcaststream_reset(mcaststream_tapinfo_t *tapinfo)
{
	GList* list;

	/* free the data items first */
	list = g_list_first(tapinfo->strinfo_list);
	while (list)
	{
		/* XYZ I don't know how to clean this */
		/*g_free(list->element.buff); */
		g_free(list->data);
		list = g_list_next(list);
	}
	g_list_free(tapinfo->strinfo_list);
	tapinfo->strinfo_list = NULL;

	/* XYZ and why does the line below causes a crach? */
	/*g_free(tapinfo->allstreams->element.buff);*/
	g_free(tapinfo->allstreams);
	tapinfo->allstreams = NULL;

	tapinfo->nstreams = 0;
	tapinfo->npackets = 0;

	++(tapinfo->launch_count);

	return;
}

static void mcaststream_reset_cb(void *arg)
{
	mcaststream_reset(arg);
}

/****************************************************************************/
/* redraw the output */
static void mcaststream_draw(void *arg _U_)
{
/* XXX: see mcaststream_on_update in mcast_streams_dlg.c for comments
	gtk_signal_emit_by_name(top_level, "signal_mcaststream_update");
*/
	mcaststream_dlg_update(the_tapinfo_struct.strinfo_list);
	return;
}



/****************************************************************************/
/* whenever a udp packet is seen by the tap listener */
static int mcaststream_packet(void *arg, packet_info *pinfo, epan_dissect_t *edt _U_, const void *arg2 _U_)
{
	mcaststream_tapinfo_t *tapinfo = arg;
        mcast_stream_info_t tmp_strinfo;
        mcast_stream_info_t *strinfo = NULL;
        GList* list;
	float deltatime;

        /* gather infos on the stream this packet is part of */
        COPY_ADDRESS(&(tmp_strinfo.src_addr), &(pinfo->src));
        tmp_strinfo.src_port = pinfo->srcport;
        COPY_ADDRESS(&(tmp_strinfo.dest_addr), &(pinfo->dst));
        tmp_strinfo.dest_port = pinfo->destport;

	/* first we ignore non multicast packets; we filter out only those ethernet packets
	 * which start with the 01:00:5E multicast address */
	if (strncmp("01:00:5e", g_strdup(get_addr_name(&(pinfo->dl_dst))), 8) != 0)
		return 0;

	/* check wether we already have a stream with these parameters in the list */
	list = g_list_first(tapinfo->strinfo_list);
	while (list)
	{
		if (mcast_stream_info_cmp(&tmp_strinfo, (mcast_stream_info_t*)(list->data))==0)
		{
			strinfo = (mcast_stream_info_t*)(list->data);  /*found!*/
			break;
		}
		list = g_list_next(list);
	}

	/* not in the list? then create a new entry */
	if (!strinfo) {
		/*printf("nov sip %s sp %d dip %s dp %d\n", g_strdup(get_addr_name(&(pinfo->src))), 
			pinfo->srcport, g_strdup(get_addr_name(&(pinfo->dst))), pinfo->destport);*/
		tmp_strinfo.npackets = 0;
		tmp_strinfo.apackets = 0;
		tmp_strinfo.first_frame_num = pinfo->fd->num;
		tmp_strinfo.start_sec = (guint32) pinfo->fd->abs_ts.secs;
		tmp_strinfo.start_usec = pinfo->fd->abs_ts.nsecs/1000;
		tmp_strinfo.start_rel_sec = (guint32) pinfo->fd->rel_ts.secs;
		tmp_strinfo.start_rel_usec = pinfo->fd->rel_ts.nsecs/1000;
		tmp_strinfo.vlan_id = 0;

		/* reset Mcast stats */
		tmp_strinfo.average_bw = 0;
		tmp_strinfo.total_bytes = 0;

		/* reset slidingwindow and buffer parameters */
		tmp_strinfo.element.buff = (struct timeval *)g_malloc(buffsize * sizeof(struct timeval));
		tmp_strinfo.element.first=0;
		tmp_strinfo.element.last=0;
		tmp_strinfo.element.burstsize=1;
		tmp_strinfo.element.topburstsize=1;
		tmp_strinfo.element.numbursts=0;
		tmp_strinfo.element.burststatus=0;
		tmp_strinfo.element.count=1;
		tmp_strinfo.element.buffusage=pinfo->fd->pkt_len;
		tmp_strinfo.element.topbuffusage=pinfo->fd->pkt_len;
		tmp_strinfo.element.numbuffalarms=0;
		tmp_strinfo.element.buffstatus=0;
		tmp_strinfo.element.maxbw=0;

		strinfo = g_malloc(sizeof(mcast_stream_info_t));
		*strinfo = tmp_strinfo;  /* memberwise copy of struct */
		tapinfo->strinfo_list = g_list_append(tapinfo->strinfo_list, strinfo);
		strinfo->element.buff = (struct timeval *)g_malloc(buffsize * sizeof(struct timeval));

		/* set time with the first packet */
		if (tapinfo->npackets == 0) {
			tapinfo->allstreams = g_malloc(sizeof(mcast_stream_info_t));
			tapinfo->allstreams->element.buff = 
					(struct timeval *)g_malloc(buffsize * sizeof(struct timeval));
			tapinfo->allstreams->start_rel_sec = (guint32) pinfo->fd->rel_ts.secs;
			tapinfo->allstreams->start_rel_usec = pinfo->fd->rel_ts.nsecs/1000;
			tapinfo->allstreams->total_bytes = 0;
			tapinfo->allstreams->element.first=0;
			tapinfo->allstreams->element.last=0;
			tapinfo->allstreams->element.burstsize=1;
			tapinfo->allstreams->element.topburstsize=1;
			tapinfo->allstreams->element.numbursts=0;
			tapinfo->allstreams->element.burststatus=0;
			tapinfo->allstreams->element.count=1;
			tapinfo->allstreams->element.buffusage=pinfo->fd->pkt_len;
			tapinfo->allstreams->element.topbuffusage=pinfo->fd->pkt_len;
			tapinfo->allstreams->element.numbuffalarms=0;
			tapinfo->allstreams->element.buffstatus=0;
			tapinfo->allstreams->element.maxbw=0;
		}
	}

	/* time between first and last packet in the group */
	strinfo->stop_rel_sec = (guint32) pinfo->fd->rel_ts.secs;
	strinfo->stop_rel_usec = pinfo->fd->rel_ts.nsecs/1000;
	deltatime = ((float)((strinfo->stop_rel_sec * 1000000 + strinfo->stop_rel_usec)
					- (strinfo->start_rel_sec*1000000 + strinfo->start_rel_usec)))/1000000;

	/* calculate average bandwidth for this stream */
	strinfo->total_bytes = strinfo->total_bytes + pinfo->fd->pkt_len;
	if (deltatime > 0)
		strinfo->average_bw = (((float)(strinfo->total_bytes*8) / deltatime) / 1000000);

	/* increment the packets counter for this stream and calculate average pps */
	++(strinfo->npackets);
	strinfo->apackets = (guint32) (strinfo->npackets / deltatime);

	/* time between first and last packet in any group */
	tapinfo->allstreams->stop_rel_sec = (guint32) pinfo->fd->rel_ts.secs;
	tapinfo->allstreams->stop_rel_usec = pinfo->fd->rel_ts.nsecs/1000;
	deltatime = ((float)((tapinfo->allstreams->stop_rel_sec * 1000000 + tapinfo->allstreams->stop_rel_usec)
		- (tapinfo->allstreams->start_rel_sec*1000000 + tapinfo->allstreams->start_rel_usec)))/1000000;

	/* increment the packets counter of all streams */
	++(tapinfo->npackets);

	/* calculate average bandwidth for all streams */
	tapinfo->allstreams->total_bytes = tapinfo->allstreams->total_bytes + pinfo->fd->pkt_len;
	if (deltatime > 0)
		tapinfo->allstreams->average_bw = (((float)(tapinfo->allstreams->total_bytes *8) / deltatime) / 1000000);

	/* sliding window and buffercalc for this group*/
	slidingwindow(strinfo, pinfo);
	buffusagecalc(strinfo, pinfo, emptyspeed*1000);
	/* sliding window and buffercalc for all groups */
	slidingwindow(tapinfo->allstreams, pinfo);
	buffusagecalc(tapinfo->allstreams, pinfo, cumulemptyspeed*1000);
	/* end of sliding window */

	return 1;  /* refresh output */

}

/****************************************************************************/
/* scan for Mcast streams */
void mcaststream_scan(void)
{
	gboolean was_registered = the_tapinfo_struct.is_registered;
	if (!the_tapinfo_struct.is_registered)
		register_tap_listener_mcast_stream();

	cf_retap_packets(&cfile, FALSE);

	if (!was_registered)
		remove_tap_listener_mcast_stream();
}


/****************************************************************************/
const mcaststream_tapinfo_t* mcaststream_get_info(void)
{
	return &the_tapinfo_struct;
}


/****************************************************************************/
/* TAP INTERFACE */
/****************************************************************************/

/* XXX just copied from gtk/rpc_stat.c */
void protect_thread_critical_region(void);
void unprotect_thread_critical_region(void);

/****************************************************************************/
void
remove_tap_listener_mcast_stream(void)
{
	if (the_tapinfo_struct.is_registered) {
		protect_thread_critical_region();
		remove_tap_listener(&the_tapinfo_struct);
		unprotect_thread_critical_region();

		the_tapinfo_struct.is_registered = FALSE;
	}
}


/****************************************************************************/
void
register_tap_listener_mcast_stream(void)
{
	GString *error_string;
	if (!the_tapinfo_struct.is_registered) {
		error_string = register_tap_listener("udp", &the_tapinfo_struct,
			NULL, mcaststream_reset_cb, mcaststream_packet,
			mcaststream_draw);

		if (error_string != NULL) {
			simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
				      error_string->str);
			g_string_free(error_string, TRUE);
			exit(1);
		}

		the_tapinfo_struct.is_registered = TRUE;
	}
}

/*******************************************************************************/
/* sliding window and buffer calculations */

/* compare two times */
guint16 comparetimes(struct timeval *t1, struct timeval *t2, guint16 burstint){
    if(((t2->tv_sec - t1->tv_sec)*1000 + (t2->tv_usec - t1->tv_usec)/1000) > burstint){
        return 1;
    } else{
        return 0;
    }
}

/* calculate buffer usage */
void buffusagecalc(mcast_stream_info_t *strinfo, packet_info *pinfo, double emptyspeed)
{
    gint32 sec=0, usec=0, cur, prev;
    struct timeval *buffer;
    double timeelapsed;

    buffer = strinfo->element.buff;
    cur = strinfo->element.last;
    if(cur == 0){
        cur = buffsize - 1;
        prev = cur - 1;
    } else if(cur == 1){
        prev = buffsize - 1;
        cur = 0;
    } else{
        cur=cur-1;
        prev=cur-1;
    }

    sec = buffer[cur].tv_sec - buffer[prev].tv_sec;
    usec = buffer[cur].tv_usec - buffer[prev].tv_usec;
    timeelapsed = (double)usec/1000000 + (double)sec;

    /* bytes added to buffer */
    strinfo->element.buffusage+=pinfo->fd->pkt_len;

    /* bytes cleared from buffer */
    strinfo->element.buffusage-= (guint32) (timeelapsed * emptyspeed / 8);

    if(strinfo->element.buffusage < 0) strinfo->element.buffusage=0;
    if(strinfo->element.buffusage > strinfo->element.topbuffusage) 
				strinfo->element.topbuffusage = strinfo->element.buffusage;
    /* check for buffer losses */
    if((strinfo->element.buffusage >= bufferalarm) && (strinfo->element.buffstatus == 0)){
        strinfo->element.buffstatus = 1;
        strinfo->element.numbuffalarms++;
    } else if(strinfo->element.buffusage < bufferalarm){
        strinfo->element.buffstatus = 0;
    }

    return;
}

/* sliding window calculation */
void slidingwindow(mcast_stream_info_t *strinfo, packet_info *pinfo)
{
    struct timeval *buffer;
    gint32 diff;

    buffer = strinfo->element.buff;

    diff = strinfo->element.last - strinfo->element.first;
    if(diff < 0) diff+=buffsize;

    /* check if buffer is full */
    if(diff >= (buffsize - 2)){
        fprintf(stderr, "Warning: capture buffer full\n");
        strinfo->element.first++;
        if(strinfo->element.first >= buffsize) strinfo->element.first = strinfo->element.first % buffsize;
    }

    /* burst count */
    buffer[strinfo->element.last].tv_sec = (guint32) pinfo->fd->rel_ts.secs;
    buffer[strinfo->element.last].tv_usec = pinfo->fd->rel_ts.nsecs/1000;
    while(comparetimes((struct timeval *)&(buffer[strinfo->element.first]), 
						(struct timeval *)&(buffer[strinfo->element.last]), burstint)){
        strinfo->element.first++;
        if(strinfo->element.first >= buffsize) strinfo->element.first = strinfo->element.first % buffsize;
        diff--;
    }
    strinfo->element.burstsize = diff;
    if(strinfo->element.burstsize > strinfo->element.topburstsize) {
	strinfo->element.topburstsize = strinfo->element.burstsize;
	strinfo->element.maxbw = (float)(strinfo->element.topburstsize) * 1000 / burstint * pinfo->fd->pkt_len * 8 / 1000000;
    }

    strinfo->element.last++;
    if(strinfo->element.last >= buffsize) strinfo->element.last = strinfo->element.last % buffsize;
    /* trigger check */
    if((strinfo->element.burstsize >= trigger) && (strinfo->element.burststatus == 0)){
        strinfo->element.burststatus = 1;
        strinfo->element.numbursts++;
    } else if(strinfo->element.burstsize < trigger){
        strinfo->element.burststatus = 0;
    }

    strinfo->element.count++;
}