E: Internal Error, No file name for libssl1.0.0

The problem of libssl1.0.0 in Ubuntu 12.04 is "E: Internal Error, No file name for libssl1.0.0". So we can type:

sudo apt-get update

sudo apt-get clean

sudo apt-get install -fy

sudo dpkg -i /var/cache/apt/archives/*.deb

sudo dpkg --configure -a

sudo apt-get install -fy

sudo apt-get dist-upgrade

This method could solve the problem.

Ubuntu login from GUI and command line

Switch to command prompt: Ctrl + F1

Switch to GUI: Ctrl + F7

Command line to start GUI: sudo lightdm

Programming on Tinyos

Installation (a simple way)

1) deb http://tinyos.stanford.edu/tinyos/dists/ubuntu natty main

2) sudo apt-get update

3) sudo apt-get install tinyos

4) sudo apt-get install tinyos-2.1.1

5) Add the following line to your ~/.bashrc or ~/.profile file in your home directory to set up the environment for TinyOS development at login

#Sourcing the tinyos environment variable setup script

source /opt/tinyos-2.1.1/tinyos.sh

How to decompress multiple files on Linux

To unzip multiple zipped .zip files:

for file in *.zip; do unzip "${file}"; done

To unzip multiple zipped .gz files;

gunzip *.gz

To unzip multiple zipped .bz2 files;

bunzip2 *.bz2

To extract multiple .tar.gz files;

for file in *.tar.gz; do tar zxf "${file}"; done

To extract multiple .tar.bz2 files;

for file in *.tar.bz2; do tar jxf "${file}"; done

Generate ssh key on Mac OS

Open a terminal and enter the following commands,

$ cd ~/

$ ssh-keygen -t rsa

It will ask you to specify the location, so just use the default one (~/.ssh/id_rsa.pub) by pressing return. If you do not need passphrase, just press return. After that, you may get something like this,

Your identification has been saved in /Users/username/.ssh/id_rsa.

Your public key has been saved in /Users/username/.ssh/id_rsa.pub.

The key fingerprint is:

45:a0:5b:34:23:73:8c:43:03:27:b5:92:9d:80:b1:7d

yourusername@XXXmac

The key's randomart image is:


+--[ RSA 2048]----+
|     ...  o*+=*o.|
|      ... = -+++ |
|        .. + ..+.|
|         ..     .|
|        P  .     |
|         .. Y    |
|           x     |
|          .      |
|                 |
+-----------------+

Then you can find your public key in the "file ~/.ssh/id_rsa.pub".

How to format a hard drive for Mac OS

Video tutorial links:

http://www.youtube.com/watch?v=8te1bg07MsQ

http://www.youtube.com/watch?v=WzQF0Qo5Kv0

Command line to check the version

We can use this command to check whether the linux is 32 bits or 64 bits:

uname -m

if the output is i686, then it is 32 bits;

if the output is x86_64, then it is 64 bits.

How to change the icon of an application

First of all, copy the new icon into clipboard;

Then, open the Info window for the application (File » Get Info, or Command-I), click the icon in that window (a blue border will appear), and paste in a new icon.

Ubuntu 11.04 bug - Update Manager

When I logged in my Ubuntu, update manager window was popped up to ask for update. I clicked "Install Updates" button, but this time it said "waiting for apt-get to exit..." and then the window was dead. I closed all the other applications including firefox, terminal and editor, but the problem was not solved.

So I posted a bug report to the website. Someone suggested to restart virtual machine in order to solve it. Then I tried it. I did not know why my Ubuntu got this problem but this solution did work.

Good luck, Ubuntu!

Compile java files in all subfolders

On Windows...

Firstly create a batch file as complie.bat. Write these lines in that

for /r %%a in (*.java) do ( javac "%%a" )

now execute.

On Linux....

javac $(find ./rootdir/* | grep .java)

2012 ACM ICPC Final

Check out the problems

https://icpc.baylor.edu/ICPCWiki/attach/Problem%20Resources/icpc2012.pdf

And the final results

http://icpc.baylor.edu/ICPCWiki/Wiki.jsp?page=Results+World+Finals+2012

How to program nodes movement using FOR loop in NS2

In fact, we know how to set the nodes` movement in NS2, it could be < $ns at TIME "$NODE1 setdest $val(X1) $val(Y1) SPEED" >. However, for some scenario, it may contain a large number of nodes` movement and simulation time could be one or several hours. It is impossible to program in this static way.

So we consider using a FOR loop. Here is an example where a node is moving up and down. The simulation time can be any value and we just need five lines program. The program is like the following,


for {set i 1} {$i < ($val(stop))} {set i [expr {$i + 10}]} {


$ns at $i "$node_(1) setdest $val(X1) $val(Y1) NodeSpeed"


set i [expr {$i + 10}]


$ns at $i "$node_(1) setdest $val(X2) $val(Y2) NodeSpeed"


}

Extend hard disc space for VMware in Mac OS

It is a common problem that the system space in the virtual machine is not enough we allocated before. We may need to extend its size after the system installation. So here is the way.

1) Open VMware Fusion and choose your virtual machine from the "Virtual Machine Library" list. Choose "Settings" from the "Virtual Machine" menu and select "Hard Disks."

2) Adjust the size of your hard disk by using the slider. Click "Apply" when finished.

If you have a Windows 7 or Vista virtual machine,

3) Start your virtual machine and log in as an administrator. Click "Start" and select "Control Panel." Click "System and Security" and then "Administrative Tools." Double-click the "Computer Management" option and click "Disk Management" on the left pane of the window that appears. Right-click on your virtual machine's volume and choose "Extend Volume." Click "Next" twice and then "Finish.

Some math symbols in LaTeX

Check the number of words in LATEX

We use a perl program to count the LATEX article words.



BEGIN {

%cutlist = (

'begin' => 1,

'end' => 1,

'usepackage' => 1,

'addtolength' => 1,

'documentclass' => 1,

'author' => 1,

'title' => 1,

'chapter' => 1,

'bibliography' => 1,

'bibliographystyle' => 1,

'section' => 1,

'subsection' => 1,

'subsubsection' => 1,

'thanks' => 1,

'pagestyle' => 1,

);

my $line = '';

my $cumline = '';

my $depth = 0;

my $words = 0;

my $fnwords = 0;

my $i = 0;

my @tags = ();

my $thistag = '';

}


$line = $_;



# Regularize line endings

$line =~ s/\r/\n/g;



# Remove comments

$line =~ s/(?


# Count curly braces

while($line =~ /\{/g){$depth++}

while($line =~ /\}/g){$depth--}






$cumline .= $line;


if ($depth == 0) {


while($cumline =~ s/(\\\w+)?\s*\{([^\{\}]*)\}/<"$i"<$2>"$i">/s){push @tags, $1; $i++;}


$i = 0;

while($#tags >= 0){

$thistag = shift @tags;

$thistag =~ s/\\//;


if ($thistag eq 'footnote') {

# Footnotes are counted separately.

$cumline =~ s/<"$i"<(.*)>"$i">//s;

$line = $1;

while($line =~ /\b\w+\b/g){$fnwords++};


} elsif (defined($cutlist{$thistag})) {


# The arguments of these tags are removed.

$cumline =~ s/<"$i"<.*>"$i">//s;


} else {


# The arguments of other tags are left in.

$cumline =~ s/<"$i"<(.*)>"$i">/$1/s;


};


$i++;

}



$cumline =~ s/\\\w+//g;




# Count the remaining words in the present bit of text.

while($cumline =~ /\b\w+\b/g){$words++}

$cumline = '';

$i = 0;

}



END{

print "\n$words words in the main text\n$fnwords in the footnotes\n";

print ($words+$fnwords);

print " total\n\n";

}



Store this program in a XXX.pl file, and run it in command line.


>perl XXX.pl foo.tex

Add multiple Interfaces and multiple channels into NS2.34

First of all, I install ns2.34 on Ubuntu 11.04. If you don`t know how to do it, just follow this page, http://itantenna.blogspot.com/2012/01/install-ns234-on-ubuntu-1004.html

Here, I just give the program which I modified. If you want to check the details, please download this document, http://personales.unican.es/aguerocr/files/ucMultiIfacesSupport.pdf. Please notice that I am not following this tutorial wholly.

Before we modify the original NS2 program, we`d better make a backup copy of it.(This is very important) OK, the first file we need to modify is "ns-lib.tcl". We will define four procedures,


-------------------------------------/tcl/lib/ns-lib.tcl-----------------------------------------------------------



Simulator instproc change−numifs {newnumifs} {

$self instvar numifs_

set numifs_ $newnumifs

}

Simulator instproc add−channel {indexch ch} {

$self instvar chan

set chan($indexch) $ch

}

Simulator instproc get−numifs { } {

$self instvar numifs

if [ info exists numifs ] {

return $numifs }else{

return ””

}

}

Simulator instproc ifNum {val} {$self set numifs $val}


Then changes the "node-config" procedure like this,

Simulator instproc node−config args {

......

set args [eval $self init−vars $args]

$self instvar addressType_ routingAgent_ propType_ macTrace_ \

routerTrace_ agentTrace_ movementTrace_ channelType_ channel_ numifs_ \

chan_ topoInstance_ propInstance_ mobileIP_ rxPower_ \

# change wrt Mike ’ s code

txPower_ idlePower_ satNodeType_ eotTrace_

......

# Single channel, single interface

warn ”Please use −channel as shown in tcl/ex/
wireless−mitf.tcl”

if {![ info exists chan]} {

set chan [new $channelType_ ]

}

} elseif {[info exists channel_ ]} {


# Multiple channel, multiple interfaces

if {[ info exists numifs_ ]} {

set chan(0) $channel_ } else {

set chan $channel_

}


if [ info exists topoInstance_ ] {

$propInstance_ topography $topoInstance_

}

......

Simulator instproc create−wireless−node args {

$self instvar routingAgent_ wiredRouting_ propInstance_ llType_ \

macType_ ifqType_ ifqlen_ phyType_ chan_ antType_ energyModel_ \

initialEnergy_ txPower_ rxPower_ idlePower_ \

topoInstance_ level1_ level2_ inerrProc_ outerrProc_ FECProc_ numifs_

Simulator set IMEPFlag_ OFF

......


# Adding Interface

if {[info exist numifs_] } {

for {set i 0} {$i < $numifs_} {incr i} {

# Add one interface per channel

$node add−interface $chan( $i ) $propInstance_ $llType_ $macType_ \

$ifqType_ $ifqlen_ $phyType_ $antType_ $topoInstance_ \

$inerrProc_ $outerrProc_ $FECProc_

}

} else {

$node add−interface $chan $propInstance_ $llType_ $macType_ \

$ifqType_ $ifqlen_ $phyType_ $antType_ $topoInstance_ \

$inerrProc_ $outerrProc_ $FECProc_

}


# Attach agent

if {$routingAgent_ != ”DSR”} {

$node attach $ragent [Node set rtagent_ port_ ]

}

......



-------------------------------------/tcl/lib/ns-mobilenode.tcl-----------------------------------------------------------



......

Node/MobileNode instproc add−target { agent port } {

$self instvar dmux_ imep_ toraDebug_

set ns [ Simulator instance ]

set newapi [ $ns imep−support ]

$agent set sport_ $port


# We get the number of interfaces from the simulator object

set numIfsSimulator [ $ns get−numifs ]


# special processing for TORA/IMEP node

set toraonly [string first ”TORA” [$agent info class]]

......

#

# Special processing for ZBR

# set zbronly [string first ”ZBR” [$agent info class]]

# if {$zbronly != −1 } {

# $agent if−queue [ $self set ifq_(0) ] ;

# ifq between LL and MAC

#

if { $port == [Node set rtagent_ port_ ] } {


# Special processing when multiple interfaces are supported

if {$numIfsSimulator != ””} {

for {set i 0} {$i < [$self set nifs_]} {incr i} {

$agent if−queue $i [$self set ifq_($i)]

}

}


# Ad hoc routing agent setup needs special handling

$self add−target−rtagent $agent $port

return

}

......

Node/MobileNode instproc add−target−rtagent { agent port } {

$self instvar imep_ toraDebug_

set ns [ Simulator instance ]

set newapi [ $ns imep−support ]

set namfp [$ns get−nam−traceall]

set dmux_ [ $self demux]

set classifier_ [ $self entry]


# We see whether we have multiple interfaces in the simulation

set numIfsSimulator [ $ns get−numifs ]


# let the routing agent know about the port dmux

$agent port−dmux $dmux_

......

# second tracer to see the actual

# types of tora packets before imep packs them

if { [info exists toraDebug_] && $toraDebug_ == ”ON”} {

set sndT2 [ $self mobility−trace Send ”TRP”]

$sndT2 target $imep_(0)

$agent target $sndT2

}


$sndT target [$self set ll_(0)]

} else { ;# noIMEP

i f {$numIfsSimulator != ””} {

for {set i 0} {$i < [$self set nifs_ ]} {incr i} {

set sndT [cmu−trace Send ”RTR” $self ]

$agent target $i $sndT

$sndT target [$self set ll_($i)]

}

} else {

$agent target $sndT

$sndT target [$self set ll_(0)]

}

}


......

$imep_(0) sendtarget [ $self set ll_(0) ]

} else { ;# noIMEP


if {$numIfsSimulator != ””} {

for {set i 0} {$i< [$self set nifs_] } {incr i} {

$agent target $i [$self set ll_($i)]

}

} else {

$agent target [$self set ll_(0)]

}

}


#
# Recv Target
#

if {$newapi == ”ON” } {

[$self set ll_(0)] up−target $imep_(0)

$classifier_ defaulttarget $agent

......

Node/MobileNode instproc add−interface { channel pmodel lltype mactype qtype qlen iftype anttype topo inerrproc outerrproc fecproc} {

$self instvar arptable_ nifs_ netif_ mac_ ifq_ ll_ imep_ inerr_ outerr_ fec_

set ns [ Simulator instance ]

set imepflag [ $ns imep−support ]


set t $nifs_

incr nifs_


...

set inerr $inerr_($t)

set outerr $outerr_($t)

set fec $fec_($t)


# We also create one ARP table per interface

set arptable_($t) [new ARPTable $self $mac]

set arptable $arptable_($t)


if {$imepflag != ””} {

set drpT [ $self mobility−trace Drop ”IFQ”]

} else {

set drpT [cmu−trace Drop ”IFQ” $self ]

}

$arptable drop−target $drpT

if { $namfp != ”” } { $drpT namattach $namfp

}

#

# Link Layer

#

$ l l arptable $arptable

$ll mac $mac

$ll down−target $ifq

......

Node/MobileNode instproc init args {

...

$self instvar nifs_ arptable_ X_ Y_ Z_ nodetype_

set X 0.0

set Y 0.0

set Z 0.0


# set arptable ”” ;# no ARP table yet

set nifs 0 ;# number of network interfaces


......


Node/MobileNode instproc reset {} {

$self instvar arptable_ nifs_ netif_ mac_ ifq_ ll_ imep_

for {set i 0} {$i < $nifs_} {incr i} {

$netif_($i) reset

$mac_($i) reset

$ll_($i) reset

$ifq_($i) reset

if { [info exists opt(imep)] && $opt(imep) == ”ON” } {

$imep_( $i ) reset

}

if { $arptable_($i) != ”” } {

$arptable _( $i ) reset

}

}

}




-------------------------------------/common/mobilenode.h-----------------------------------------------------------



...


# define MAX_CHANNELS 20


...

/∗ For list−keeper ∗/


MobileNode∗ nextX_[MAX_CHANNELS] ;

MobileNode∗ prevX_[MAX_CHANNELS] ;


...

void start(void);


void getLoc(double ∗x, double ∗y, double ∗z);


inline void getVelo(double ∗dx, double ∗dy, double ∗dz) {

∗dx= dX_ ∗ speed_; ∗dy= dY_ ∗ speed_; ∗dz= 0.0;

}

...




-------------------------------------/common/mobilenode.cc-----------------------------------------------------------




void MobileNode::getLoc(double ∗x, double ∗y, double ∗z)

{

update position ()

∗x = X_;

∗y = Y_;

∗z = Z_;

}





-------------------------------------/mac/channel.cc-----------------------------------------------------------


Replace ALL the nextX_ and prevX_ by the following arrays in this program.


nextX_[this−>index()]

prevX_[this−>index()]


And modify this part,


affectedNodes = getAffectedNodes(mtnode, distCST_ + /∗ safety ∗/ 5, &numAffectedNodes ) ;

for (i=0; i < numAffectedNodes; i++) {

rnode = affectedNodes [ i ] ;

if (rnode == tnode)

continue ;

newp = p−>copy();

propdelay = get_pdelay(tnode, rnode);

rifp = (rnode−>ifhead()).lh_first;

for(; rifp; rifp = rifp−>nextnode()){


if(rifp−>channel() == this) {

s.schedule(rifp , newp, propdelay);

}


}

}

delete []affectedNodes ;




-------------------------------------/mac/mac-802_11.cc-----------------------------------------------------------



......

if(tx_active_ && hdr−>error() == 0) {

hdr−>error () = 1;

}


hdr−>iface() = addr();


if(rx_state_ == MAC_IDLE){

......



For routing part, I use the AODV protocol as an example here.


-------------------------------------/aodv/aodv.h-----------------------------------------------------------



......

# define MinHelloInterval (0.75 * HELLO_INTERVAL)


# define MAX_IF 11


......

/*
* Route Table Management
*/

void rt_update(aodv_rt_entry *rt, u_int32_t seqnum, u_int16_t metric, nsaddr_t nexthop, double expire_time, u_int8_t interface);

......


int nIfaces ;

NsObject ∗targetlist[MAX_IF];

PriQueue ∗ifqueuelist [MAX_IF];



......


-------------------------------------/aodv/aodv.cc-----------------------------------------------------------



......

int

AODV::command(int argc, const char*const* argv) {

......

else if(argc == 3) {

......

}


else if(argc == 4) {

if (strcmp(argv[1] ,”if−queue”) == 0) {

PriQueue ∗ ifq = (PriQueue ∗) TclObject::lookup(argv[3]);

int temp_ = atoi(argv[2]);

if(temp_ == nIfaces) {

nIfaces++;

}

ifqueuelist [temp_] = ifq ;

if (ifqueuelist[temp_]) {

return TCL_OK;

}else{

return TCL_ERROR;

}

}

if (strcmp(argv[1] ,”target”) == 0) {

int temp_ = atoi(argv[2]);

if(temp_ == nIfaces) {

nIfaces++;

}

targetlist[temp_] = (NsObject ∗) TclObject::lookup(argv[3]);

if(targetlist[temp_]) {

return TCL_OK;

} else {

return TCL_ERROR;

}

}

}


return Agent::command(argc, argv);

} // Be careful, there are many brackets here!

/*

Constructor

*/

AODV::AODV(nsaddr_t id) : Agent(PT_AODV), btimer(this), htimer(this), ntimer(this), rtimer(this), lrtimer(this), rqueue() {

index = id;

seqno = 2;

bid = 1;

LIST_INIT(&nbhead);

LIST_INIT(&bihead);

logtarget = 0;

ifqueue = 0;


nIfaces = 0;


}

......

void

AODV::rt_update(aodv_rt_entry *rt, u_int32_t seqnum, u_int16_t metric,
nsaddr_t nexthop, double expire_time, u_int8_t interface) {

rt->rt_seqno = seqnum;

rt->rt_hops = metric;

rt->rt_flags = RTF_UP;

rt->rt_nexthop = nexthop;

rt->rt_expire = expire_time;


rt->rt_interface = interface;


}

......

void

AODV::recvRequest(Packet *p) {

struct hdr_ip *ih = HDR_IP(p);

struct hdr_aodv_request *rq = HDR_AODV_REQUEST(p);

aodv_rt_entry *rt;


struct hdr_cmn *ch = HDR_CMN(p);

u_int8_t Iface;


...

}

......

if ( (rq->rq_src_seqno > rt0->rt_seqno ) || ((rq->rq_src_seqno == rt0->rt_seqno) && (rq->rq_hop_count < rt0->rt_hops)) ) {

// If we have a fresher seq no. or lesser #hops for the

// same seq no., update the rt entry. Else don't bother.


if(nIfaces){

Iface = ch ->iface()-((Mac *) ifqueuelist[0]->target())->addr();

} else {

Iface = -1;

}


rt_update(rt0, rq->rq_src_seqno, rq->rq_hop_count, ih->saddr(),
max(rt0->rt_expire, (CURRENT_TIME + REV_ROUTE_LIFE)), Iface );

if (rt0->rt_req_timeout > 0.0) {

// Reset the soft state and

// Set expiry time to CURRENT_TIME + ACTIVE_ROUTE_TIMEOUT

// This is because route is used in the forward direction,

// but only sources get benefited by this change

rt0->rt_req_cnt = 0;

rt0->rt_req_timeout = 0.0;

rt0->rt_req_last_ttl = rq->rq_hop_count;

rt0->rt_expire = CURRENT_TIME + ACTIVE_ROUTE_TIMEOUT;

}

...

}

......

void

AODV::recvReply(Packet *p) {

//struct hdr_cmn *ch = HDR_CMN(p);

struct hdr_ip *ih = HDR_IP(p);

struct hdr_aodv_reply *rp = HDR_AODV_REPLY(p);

aodv_rt_entry *rt;

char suppress_reply = 0;

double delay = 0.0;

#ifdef DEBUG

fprintf(stderr, "%d - %s: received a REPLY\n", index, __FUNCTION__);

#endif // DEBUG


struct hdr_cmn *ch = HDR_CMN(p);

u_int8_t Iface;


...


if(nIfaces){

Iface = ch ->iface()-((Mac *) ifqueuelist[0]->target())->addr();

} else {

Iface = -1;

}


rt_update(rt, rp->rp_dst_seqno, rp->rp_hop_count,
rp->rp_src, CURRENT_TIME + rp->rp_lifetime, Iface);

// reset the soft state

rt->rt_req_cnt = 0;

rt->rt_req_timeout = 0.0;

rt->rt_req_last_ttl = rp->rp_hop_count;

...

}

......

void

AODV::forward(aodv_rt_entry *rt, Packet *p, double delay) {

struct hdr_cmn *ch = HDR_CMN(p);

struct hdr_ip *ih = HDR_IP(p);

if(ih->ttl_ == 0) {

#ifdef DEBUG

fprintf(stderr, "%s: calling drop()\n", __PRETTY_FUNCTION__);

#endif // DEBUG

drop(p, DROP_RTR_TTL);

return;

}

if (ch->ptype() != PT_AODV && ch->direction() == hdr_cmn::UP &&
((u_int32_t)ih->daddr() == IP_BROADCAST)
|| (ih->daddr() == here_.addr_)) {

dmux_->recv(p,0);

return;

}

if (rt) {

assert(rt->rt_flags == RTF_UP);

rt->rt_expire = CURRENT_TIME + ACTIVE_ROUTE_TIMEOUT;

ch->next_hop_ = rt->rt_nexthop;

ch->addr_type() = NS_AF_INET;

ch->direction() = hdr_cmn::DOWN; //important: change the packet's direction

}

else { // if it is a broadcast packet

// assert(ch->ptype() == PT_AODV); // maybe a diff pkt type like gaf

assert(ih->daddr() == (nsaddr_t) IP_BROADCAST);

ch->addr_type() = NS_AF_NONE;

ch->direction() = hdr_cmn::DOWN; //important: change the packet's direction

}

if (ih->daddr() == (nsaddr_t) IP_BROADCAST) {

// If it is a broadcast packet

assert(rt == 0);

if (ch->ptype() == PT_AODV) {

/*

* Jitter the sending of AODV broadcast packets by 10ms

*/


if(nIfaces) {

for(int i=0; i
Packet *p_copy = p->copy();

Scheduler::instance().schedule(targetlist[i], p_copy, 0.01*Random::uniform());

}

Packet::free(p);

} else {

Scheduler::instance().schedule(target_, p, 0.01*Random::uniform()); // No jitter

}

} else {

if(nIfaces) {

for(int i=0; i
Packet *p_copy = p->copy();

Scheduler::instance().schedule(targetlist[i], p_copy, 0);

}

Packet::free(p);

} else {

Scheduler::instance().schedule(target_, p, 0); // No jitter

}

}

}

else { // Not a broadcast packet

if(delay > 0.0) {

if(nIfaces) {

Scheduler::instance().schedule(targetlist[rt->rt_interface], p, delay);

} else {

Scheduler::instance().schedule(target_, p, delay);

}

}

else {

// Not a broadcast packet, no delay, send immediately

if(nIfaces) {

Scheduler::instance().schedule(targetlist[rt->rt_interface], p, 0.);

} else {

Scheduler::instance().schedule(target_, p, 0.);

}

}

}


} // Be careful, many brackets here!

......

void

AODV::sendReply(nsaddr_t ipdst, u_int32_t hop_count, nsaddr_t rpdst,
u_int32_t rpseq, u_int32_t lifetime, double timestamp) {

Packet *p = Packet::alloc();

struct hdr_cmn *ch = HDR_CMN(p);

struct hdr_ip *ih = HDR_IP(p);

struct hdr_aodv_reply *rp = HDR_AODV_REPLY(p);

aodv_rt_entry *rt = rtable.rt_lookup(ipdst);

#ifdef DEBUG

fprintf(stderr, "sending Reply from %d at %.2f\n", index, Scheduler::instance().clock());

#endif // DEBUG

assert(rt);

rp->rp_type = AODVTYPE_RREP;

//rp->rp_flags = 0x00;

rp->rp_hop_count = hop_count;

rp->rp_dst = rpdst;

rp->rp_dst_seqno = rpseq;

rp->rp_src = index;

rp->rp_lifetime = lifetime;

rp->rp_timestamp = timestamp;

// ch->uid() = 0;

ch->ptype() = PT_AODV;

ch->size() = IP_HDR_LEN + rp->size();

ch->iface() = -2;

ch->error() = 0;

ch->addr_type() = NS_AF_INET;

ch->next_hop_ = rt->rt_nexthop;

ch->prev_hop_ = index; // AODV hack

ch->direction() = hdr_cmn::DOWN;


ih->saddr() = index;

ih->daddr() = ipdst;

ih->sport() = RT_PORT;

ih->dport() = RT_PORT;

ih->ttl_ = NETWORK_DIAMETER;


if(nIfaces) {

Scheduler::instance().schedule(targetlist[rt->rt_interface], p, 0.);

} else {

Scheduler::instance().schedule(target_, p, 0.);

}


}

void

AODV::sendError(Packet *p, bool jitter) {

struct hdr_cmn *ch = HDR_CMN(p);

struct hdr_ip *ih = HDR_IP(p);

struct hdr_aodv_error *re = HDR_AODV_ERROR(p);

#ifdef ERROR

fprintf(stderr, "sending Error from %d at %.2f\n", index, Scheduler::instance().clock());

#endif // DEBUG

re->re_type = AODVTYPE_RERR;

//re->reserved[0] = 0x00; re->reserved[1] = 0x00;

// DestCount and list of unreachable destinations are already filled

// ch->uid() = 0;

ch->ptype() = PT_AODV;

ch->size() = IP_HDR_LEN + re->size();

ch->iface() = -2;

ch->error() = 0;

ch->addr_type() = NS_AF_NONE;

ch->next_hop_ = 0;

ch->prev_hop_ = index; // AODV hack

ch->direction() = hdr_cmn::DOWN; //important: change the packet's direction

ih->saddr() = index;

ih->daddr() = IP_BROADCAST;

ih->sport() = RT_PORT;

ih->dport() = RT_PORT;

ih->ttl_ = 1;

// Do we need any jitter? Yes


if (jitter) {

if(nIfaces) {

for(int i=0; i
Packet *p_copy = p->copy();

Scheduler::instance().schedule(targetlist[i], p_copy, 0.01*Random::uniform());

}

Packet::free(p);

} else {

Scheduler::instance().schedule(target_, p, 0.01*Random::uniform());

}

}

else {

if(nIfaces) {

for(int i=0; i
Packet *p_copy = p->copy();

Scheduler::instance().schedule(targetlist[i], p_copy, 0.0);

}

Packet::free(p);

}

else {

Scheduler::instance().schedule(target_, p, 0.0);

}

}

}

void

AODV::sendHello() {

Packet *p = Packet::alloc();

struct hdr_cmn *ch = HDR_CMN(p);

struct hdr_ip *ih = HDR_IP(p);

struct hdr_aodv_reply *rh = HDR_AODV_REPLY(p);

#ifdef DEBUG

fprintf(stderr, "sending Hello from %d at %.2f\n", index, Scheduler::instance().clock());

#endif // DEBUG



rh->rp_type = AODVTYPE_HELLO;

//rh->rp_flags = 0x00;

rh->rp_hop_count = 1;

rh->rp_dst = index;

rh->rp_dst_seqno = seqno;

rh->rp_lifetime = (1 + ALLOWED_HELLO_LOSS) * HELLO_INTERVAL;

// ch->uid() = 0;

ch->ptype() = PT_AODV;

ch->size() = IP_HDR_LEN + rh->size();

ch->iface() = -2;

ch->error() = 0;

ch->addr_type() = NS_AF_NONE;

ch->prev_hop_ = index; // AODV hack

ih->saddr() = index;

ih->daddr() = IP_BROADCAST;

ih->sport() = RT_PORT;

ih->dport() = RT_PORT;

ih->ttl_ = 1;


if(nIfaces) {

for(int i=0; i
Packet *p_copy = p->copy();

Scheduler::instance().schedule(targetlist[i], p_copy, 0.0);

}

Packet::free(p);

}

else {

Scheduler::instance().schedule(target_, p, 0.0);
}


}

Record video in Ubuntu

In Ubuntu, I use XvidCap to record video on the screen. The package link is https://launchpad.net/ubuntu/natty/+package/xvidcap.

One of the most useful features of XvidCap is that it allows to select the recording area instead of the whole screen. And it also supports to output the video in MPEG format.

You may need to convert it to other video format, such as WMV, ASF, MOV and some for ipod or iphone. Since I am working on Mac OS, I recommend a free software which is called iSkysoft iMedia Converter. Actually, there is a video teaching you how to crack, http://www.youtube.com/watch?v=cLo-zuMxSNM.

Hopefully, these two softwares are helpful to you.

Set nodes` color in NS2 simulation program

This is a pretty tricky way to hit the target. And we can change the color at any time.


set ns [new Simulator]

set node [$ns node 0]

$ns at 0.0 "$node color red"

$ns at 1.0 "$node color blue"

One NS2 old trace format analysis

After NS2 simulations are finished, someone may need to analyze the trace file which is output by TCL program. I got the trace file format which is like this

"s 38.212991274 _2_ MAC --- 86 MYTYPE 178 [13a 3 2 800] ------- [2:0 3:0 30 3]"

"s 38.418136390 _3_ AGT --- 89 MYTYPE 100 [0 0 0 0] ------- [3:0 2:0 32 0]"

The first field is the event type, whose value can be s (send), r (receive), d (drop) or f (forward).

The second field the time this event happens.

The third field records the id of the node, on which this event takes place.

The fourth field shows the layer where this event happens. Its possible value may be one of the following four: AGT (agent), RTR (router), IFQ (interface queue), and MAC (mac).

The fifth field is normally a short broken line, which is reserved for special events. For example, when collision occurs, the broken line is replaced with COL.

The sixth field is the global sequence number for this packet, which is the integer number used to identify this packet in the whole network and distinguish it from others. Sequence number is only available for data packets and not allocated for control packets, like RTS/CTS/ACK and SYNC packets in S-MAC (using a zero instead).

The seventh field is the packet type. The actual value is determined by the application or MAC layer, which creates this packet. For example, cbr represents that it is a data packet generated by a CBR traffic source.

The eighth field is the packet size in bytes.

Since I use AODV routing protocol, the ninth field is AODV trace information including three numbers in brackets concerns MAC layer information. Usually, there will be four numbers in the brackets. Its format is like "[0x%x %d [%d %d] %f] (%s)" 1)| hexadecimal | Type | 2)| int | Hop Count | 3)|int | Destination | Destination Sequence Number | 4)|double | Lifetime | 5)|string | Operation (REPLY, ERROR, HELLO) |

The tenth field is IP trace info including | Source IP Address:Source Port Number | Destination IP Address:Destination Port Number | TTL Value | Next Hop Address, If Any |

Install ns2.34 on Ubuntu 10.04

1) Download ns2.34 allinone package from http://sourceforge.net/projects/nsnam/files%2Fallinone%2Fns-allinone-2.34/

2) Uncompress to your own directory by using command "tar -zvxf ns-allinone-2.34.tar.gz"

3) Install some development files,

sudo apt-get update

sudo apt-get upgrade

sudo apt-get dist-upgrade

sudo apt-get install build-essential

sudo apt-get install libc6-dev g++ gcc-4.3

sudo apt-get install tcl8.4 tcl8.4-dev tk8.4 tk8.4-dev

sudo apt-get install autoconf automake libxmu-dev libxmu-headers

4) Then,


$cd ns-allinone.2.34/

$./install

5) If got "otcl-1.13 make failed! Exiting" error,
i)edit the configure.in file in otcl-1.13, Line77 SHLIB_LD="ld -shared" -> SHLIB_LD="gcc -shared"
ii)edit the configure file in otcl-1.13, Line6304 SHLIB_LD="ld -shared" -> SHLIB_LD="gcc -shared"

6) Edit otcl-1.13/Makefile.in,

CC= @CC@ -> CC= gcc-4.3

7) Then,

$cd ns-allinone.2.34/

$./install

8) If got an error like

"`.gnu.linkonce.t._ZN11taskPending10taskStatusEh' referenced in section `.rodata' of wpan/p802_15_4mac.o: defined in discarded section `.gnu.linkonce.t._ZN11taskPending10taskStatusEh' of wpan/p802_15_4mac.o
collect2: ld returned 1 exit status
make: *** [ns] error 1"

, that is because you are using gcc3.3 to compile it. And you have to change gcc compiler version to gcc4 or above.

9) Then, it should work. Finally, dont forget to modify .bashrc file to add environment variables.

export PATH=$PATH:/YOURDIR/ns-allinone-2.34/bin:/YOURDIR/ns-allinone-2.34/tcl8.4.18/unix:/YOURDIR/ns-allinone-2.34/tk8.4.18/unix

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/YOURDIR/ns-allinone-2.34/otcl-1.13:/YOURDIR/ns-allinone-2.34/lib

export TCL_LIBRARY=$TCL_LIBRARY:/YOURDIR/ns-allinone-2.34/tcl8.4.18/library