[ns] Segmentation Fault while Modifying AODV
Dear NS2 Users
I am facing a very serious problem regarding modification to AODV protocol.
I have customized AODV Protocol to work as VANET Beaconing Protocol
according to DSRC Standard.
I also having implemented the duplicity mechansim where each node on
receiving a beacon, stores it for certain time to check for duplicity,
because i want the beacons to travel for multihops.
i have divided the road into regions and there is a linked list for every
region which stores the hashes of certain values taken from every beacon.
i have implemented all this, and when i run my tcl script, it gives
segmentation fault.
basically i get the segmentation fault after adding the following code (This
whole code is included in aodv.cc and aodv is no more a routing protocol. it
is just a VANET Beaconing protocol now which i optimized for my
simulations).
aodv/aodv.cc
recev_beacon()
{
...
...
.
receive the beacon and calculate the hash from some values
// Now Save the Beacons
if (xx=x x(xx+200))
{
bool flag=obj.search(hash2);
if (flag==TRUE)
{
coutAlready exists in the linked listendl;
}
else
{
obj.add(hash2, 1);
//ofstream list1;//for saving hash values
//list1.open(linkedlist1.dat, ios::app);
//list1hash2endl;
}
} // end of if
else if (x=xx (xx=x x(xx+400)))
{
obj.add(hash2, 2);
ofstream list2;//for saving hash values
list2.open(linkedlist2.dat, ios::app);
list2hash2endl;
}
else if (x=xx (xx=x x(xx+600)))
{
obj.add(hash2, 3);
}
else if (x=xx (xx=x x(xx+1000)))
{
obj.add(hash2, 4);
}
the linked list implemented is given below
//
// Defining Linked Lists
//
struct list1{
unsigned int bid;list1 *link;
};
struct list2{
unsigned int bid;list2 *link;
};
struct list3{
unsigned int bid;list3 *link;
};
struct list4{
unsigned int bid;list4 *link;
};
class list{
private:
int i;
list1 *cur1,*temp1,*start1;
list2 *cur2,*temp2,*start2;
list3 *cur3,*temp3,*start3;
list4 *cur4,*temp4,*start4;
public:
list()
{
start1=NULL;
start2=NULL;
start3=NULL;
start4=NULL;
}
void add(unsigned int hashval, int listno)
{
//coutEnter the list number to add element to;cini;
// check for list no.
if (listno==1)
{
if(start1==NULL)
{
start1=new list1;
cur1=start1;
cur1-bid=hashval;
cur1-link=NULL;
}
else
{
cur1-link=new list1;
cur1=cur1-link;
cur1-bid=hashval;
cur1-link=NULL;
}
}
else if (listno==2)
{
if(start2==NULL)
{
start2=new list2;
cur2=start2;
cur2-bid=hashval;
cur2-link=NULL;
}
else
{
cur2-link=new list2;
cur2=cur2-link;
cur2-bid=hashval;
cur2-link=NULL;
}
}
else if (listno==3)
{
if(start3==NULL)
{
start3=new list3;
cur3=start3;
cur3-bid=hashval;
cur3-link=NULL;
}
else
{
cur3-link=new list3;
cur3=cur3-link;
cur3-bid=hashval;
cur3-link=NULL;
}
}
else if (listno==4)
{
if(start4==NULL)
{
start4=new list4;
cur4=start4;
cur4-bid=hashval;
cur4-link=NULL;
}
else
{
cur4-link=new list4;
cur4=cur4-link;
cur4-bid=hashval;
cur4-link=NULL;
}
}
}
// searching method
bool search(unsigned int hashval)
{
bool b;
cur1=start1;
while (cur1-link!=NULL)
{
if(cur1-bid==hashval)
b=TRUE;
else
b=FALSE;
cur1=cur1-link;
}
return b;
}
I will be looking for some help as soon as possible.
THanks to all concerned in advance!!
Rasheed
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Dear NS2 Uers I am implementing VANET in NS2. I have implemented the beaconing mechansim in NS2. Now i want a vehicle to save the incoming beacons for cross-check. my beacons are going beyond one-hop. So i have to check for duplicity. Any suggetions, how it can be done? For Example i define some node to re-broadcast the beacon which it received. Now a neighbor node may already have got this beacon, but will again receive the re-broadcasted beacon. So the node should drop the duplicate beacon. Thanks in advance! Rasheed
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Dear NS Users
I want to include Sending vehicle's Speed and Lane information (while the
vehicle moves on a 4-lane road) in the frequently sent beacons while
simulating VANET scenario. Any suggestions will be most welcomed.
Thanx in advance
My Beacon format is given below:
*Struct hdr_aodv_beacon{*
*u_int8_t pkt_type; //type of packet, beacon or error*
*u_int8_t beacon_hops; //hop count*
*u_int32_t beacon_id; //unique identifier for the beacon*
*nsaddr_t beacon_src; //source of the beacon*
*double beacon_posx; //x position of beacon source*
*double beacon_posy; //y position of beacon source*
*double timestamp; //timestamp*
*.*
*};
*
Rasheed
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[ns] Adding Information in Hello Packets of AODV [Urgent]
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[ns] Problem with an Example (AODV)
Dear NS2 Users
السلام عليكم/پہ خیرراغلے/Hello/안녕하세요.
I am executing a simple tcl script given below. it contains 3 nodes and
using AODV protocol. I cannot see node2 to get any packet. Can somebody help
me what is wrong with that? I think node2 is in between node0 and node1, so
it should get packets but it is not.
It is urgent, i will be thankful if somebody can tell me about that.
Regards
# A 3-node example for ad-hoc simulation with AODV
# Define options
set val(chan) Channel/WirelessChannel ;# channel type
set val(prop) Propagation/TwoRayGround ;# radio-propagation model
set val(netif) Phy/WirelessPhy ;# network interface type
set val(mac) Mac/802_11 ;# MAC type
set val(ifq) Queue/DropTail/PriQueue ;# interface queue type
set val(ll) LL ;# link layer type
set val(ant) Antenna/OmniAntenna ;# antenna model
set val(ifqlen) 50 ;# max packet in ifq
set val(nn) 3 ;# number of mobilenodes
set val(rp) AODV ;# routing protocol
set val(x) 500 ;# X dimension of topography
set val(y) 400 ;# Y dimension of topography
set val(stop) 150 ;# time of simulation end
set ns [new Simulator]
set tracefd [open simple.tr w]
set windowVsTime2 [open win.tr w]
set namtrace [open simwrls.nam w]
$ns trace-all $tracefd
$ns namtrace-all-wireless $namtrace $val(x) $val(y)
# set up topography object
set topo [new Topography]
$topo load_flatgrid $val(x) $val(y)
create-god $val(nn)
#
# Create nn mobilenodes [$val(nn)] and attach them to the channel.
#
# configure the nodes
$ns node-config -adhocRouting $val(rp) \
-llType $val(ll) \
-macType $val(mac) \
-ifqType $val(ifq) \
-ifqLen $val(ifqlen) \
-antType $val(ant) \
-propType $val(prop) \
-phyType $val(netif) \
-channelType $val(chan) \
-topoInstance $topo \
-agentTrace ON \
-routerTrace ON \
-macTrace OFF \
-movementTrace ON
for {set i 0} {$i $val(nn) } { incr i } {
set node_($i) [$ns node]
}
# Provide initial location of mobilenodes
$node_(0) set X_ 5.0
$node_(0) set Y_ 5.0
$node_(0) set Z_ 0.0
$node_(1) set X_ 490.0
$node_(1) set Y_ 285.0
$node_(1) set Z_ 0.0
$node_(2) set X_ 150.0
$node_(2) set Y_ 240.0
$node_(2) set Z_ 0.0
# Generation of movements
$ns at 10.0 $node_(0) setdest 250.0 250.0 3.0
$ns at 15.0 $node_(1) setdest 45.0 285.0 5.0
$ns at 110.0 $node_(0) setdest 480.0 300.0 5.0
# Set a TCP connection between node_(0) and node_(1)
set tcp [new Agent/TCP/Newreno]
$tcp set class_ 2
set sink [new Agent/TCPSink]
$ns attach-agent $node_(0) $tcp
$ns attach-agent $node_(1) $sink
$ns connect $tcp $sink
set ftp [new Application/FTP]
$ftp attach-agent $tcp
$ns at 10.0 $ftp start
# Printing the window size
proc plotWindow {tcpSource file} {
global ns
set time 0.01
set now [$ns now]
set cwnd [$tcpSource set cwnd_]
puts $file $now $cwnd
$ns at [expr $now+$time] plotWindow $tcpSource $file }
$ns at 10.1 plotWindow $tcp $windowVsTime2
# Define node initial position in nam
for {set i 0} {$i $val(nn)} { incr i } {
# 30 defines the node size for nam
$ns initial_node_pos $node_($i) 30
}
# Telling nodes when the simulation ends
for {set i 0} {$i $val(nn) } { incr i } {
$ns at $val(stop) $node_($i) reset;
}
# ending nam and the simulation
$ns at $val(stop) $ns nam-end-wireless $val(stop)
$ns at $val(stop) stop
$ns at 150.01 puts \end simulation\ ; $ns halt
proc stop {} {
global ns tracefd namtrace
$ns flush-trace
close $tracefd
close $namtrace
}
$ns run
After running this and looking at the file simple.tr, i cannot find node2
to get any packet.
Regards
Rasheed
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