From Miha Jemec:

With the new feature we can: 
1. Measure how big the bursts are for a video streams (it uses sliding window algorithm) 2. Measure how big the output buffer should be that no packet drop will occur (it uses Leaky bucket algorithm) 
3. Detect if we have loses inside the MPEG2 video stream (if there are already MPEG2 packets missing) - this part of code is not added yet, see Limitations

The addition is called Multicast streams and works as follows:

- it uses the TAP system
- the main "stream" logic is taken from rtp_strems.* files
- the TAP system checks for UDP packets where the destination MAC address starts with "01:00:5E" (ethernet multicast address)
- it creates an entry for every new multicast stream
- based on sliding window and leaky bucket algorithm it calculates for every stream average BW, max BW, burst size, max buffer needed, some alarms if the limits are exceeded,...
- the same calculation is done for all streams together
- inside the window dialog you can specify the burst interval, the alarm limits and output speeds

To do & limitations:

- Currently the analysis can be done only for multicast streams, it means that VoD (Video on demand) or PayTV streams, which are normally unicast can not be analysed. 

- since the MPEG2 is patended I don't know if decoding of MPEG2 packets is allowed? Can we look inside this packets and calculate packets drops based on some counter information inside the payload? Can someone please answer this question? If we can do this, I will post this part of code too.

-  some more flexibility will be added

svn path=/trunk/; revision=17980

1 files changed, 450 insertions, 0 deletions

diff --git a/gtk/mcast_stream.c b/gtk/mcast_stream.c
new file mode 100644
index 0000000000..5ccd2cca01
--- /dev/null
+++ b/gtk/mcast_stream.c
@@ -0,0 +1,450 @@
+/* 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>
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@ethereal.com>
+ * 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 = pinfo->fd->abs_ts.secs;
+		tmp_strinfo.start_usec = pinfo->fd->abs_ts.nsecs/1000;
+		tmp_strinfo.start_rel_sec = 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 = 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 = 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 = strinfo->npackets / deltatime;
+
+	/* time between first and last packet in any group */
+	tapinfo->allstreams->stop_rel_sec = 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-=(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 = 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++;
+}
+