Re: ping use too long time - C# Discussion Boards

4-Mar-05 4:47

i use sendto and receivefrom functions to ping a host
ex:
sendto(host)
timestart = datetime.now
receivefrom(buf,edp)
timestop = datetime.now - timestart

but the time was too long ,when i ping localhost the time is 56ms
how can reduce the time?

Dave Kreskowiak4-Mar-05 7:34

4-Mar-05 7:34

Since we know nothing of how you're using the SendTo and RecieveFrom functions, and what class is supplying them, there's nothing anyone can tell you. There are a bunch of factors that will affect this, starting with the time source your using, which is terrible for the timing resolution your looking for, what size packets your sending, how name resolution is taking place, ...

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

haha200014-Mar-05 15:22

4-Mar-05 15:22

the code:

namespace mPing
{
using System;
using System.Net;
using System.Net.Sockets;
///

/// The Main Ping Class
///

class Ping
{
//Declare some Constant Variables
const int SOCKET_ERROR = -1;
const int ICMP_ECHO = 8;
///

/// The Starting Point of the Class
/// It Takes the Hostname parameter
///

public static void Main(string[] argv)
{
if(argv.Length==0)
{
//If user did not enter any Parameter inform him
Console.WriteLine("Usage:Ping <hostname> /r") ;
Console.WriteLine("<hostname> The name of the Host who you want to ping");
Console.WriteLine("/r Optional Switch to Ping the host continuously") ;
}
else if(argv.Length==1)
{
//Just the hostname provided by the user
//call the method "PingHost" and pass the HostName as a parameter
PingHost(argv[0]) ;
}
else if(argv.Length==2)
{
//the user provided the hostname and the switch
if(argv[1]=="/r")
{
//loop the ping program
while(true)
{
//call the method "PingHost" and pass the HostName as a parameter
PingHost(argv[0]) ;
}
}
else
{
//if the user provided some other switch
PingHost(argv[0]) ;
}

}
else
{
//Some error occured
Console.WriteLine("Error in Arguments") ;
}
}

///

/// This method takes the "hostname" of the server
/// and then it ping's it and shows the response time
///

public static void PingHost(string host)
{
//Declare the IPHostEntry
IPHostEntry serverHE, fromHE;
int nBytes = 0;
int dwStart = 0, dwStop = 0;
//Initilize a Socket of the Type ICMP
Socket socket = new Socket(AddressFamily.AfINet, SocketType.SockRaw, ProtocolType.ProtICMP);

// Get the server endpoint
try
{
serverHE = DNS.GetHostByName(host);
}
catch(Exception)
{
Console.WriteLine("Host not found"); // fail
return ;
}

// Convert the server IP_EndPoint to an EndPoint
IPEndPoint ipepServer = new IPEndPoint(serverHE.AddressList[0], 0);
EndPoint epServer = (ipepServer);

// Set the receiving endpoint to the client machine
fromHE = DNS.GetHostByName(DNS.GetHostName());
IPEndPoint ipEndPointFrom = new IPEndPoint(fromHE.AddressList[0], 0);
EndPoint EndPointFrom = (ipEndPointFrom);

int PacketSize = 0;
IcmpPacket packet = new IcmpPacket();
// Construct the packet to send
packet.Type = ICMP_ECHO; //8
packet.SubCode = 0;
packet.CheckSum = UInt16.Parse("0");
packet.Identifier = UInt16.Parse("45");
packet.SequenceNumber = UInt16.Parse("0");
int PingData = 32; // sizeof(IcmpPacket) - 8;
packet.Data = new Byte[PingData];
//Initilize the Packet.Data
for (int i = 0; i < PingData; i++)
{
packet.Data[i] = (byte)'#';
}

//Variable to hold the total Packet size
PacketSize = PingData + 8;
Byte [] icmp_pkt_buffer = new Byte[ PacketSize ];
Int32 Index = 0;
//Call a Methos Serialize which counts
//The total number of Bytes in the Packet
Index = Serialize(
packet,
icmp_pkt_buffer,
PacketSize,
PingData );
//Error in Packet Size
if( Index == -1 )
{
Console.WriteLine("Error in Making Packet");
return ;
}

// now get this critter into a UInt16 array

//Get the Half size of the Packet
Double double_length = Convert.ToDouble(Index);
Double dtemp = Math.Ceil( double_length / 2);
int cksum_buffer_length = Convert.ToInt32(dtemp);
//Create a Byte Array
UInt16 [] cksum_buffer = new UInt16[cksum_buffer_length];
//Code to initilize the Uint16 array
int icmp_header_buffer_index = 0;
for( int i = 0; i < cksum_buffer_length; i++ ) {
cksum_buffer[i] =
BitConverter.ToUInt16(icmp_pkt_buffer,icmp_header_buffer_index);
icmp_header_buffer_index += 2;
}
//Call a method which will return a checksum
UInt16 u_cksum = checksum(cksum_buffer, cksum_buffer_length);
//Save the checksum to the Packet
packet.CheckSum = u_cksum;

// Now that we have the checksum, serialize the packet again
Byte [] sendbuf = new Byte[ PacketSize ];
//again check the packet size
Index = Serialize(
packet,
sendbuf,
PacketSize,
PingData );
//if there is a error report it
if( Index == -1 )
{
Console.WriteLine("Error in Making Packet");
return ;
}

dwStart = System.Environment.TickCount; // Start timing
//send the Pack over the socket
if ((nBytes = socket.SendTo(sendbuf, PacketSize, 0, epServer)) == SOCKET_ERROR)
{
Console.WriteLine("Socket Error cannot Send Packet");
}
// Initialize the buffers. The receive buffer is the size of the
// ICMP header plus the IP header (20 bytes)
Byte [] ReceiveBuffer = new Byte[256];
nBytes = 0;
//Receive the bytes
bool recd =false ;
int timeout=0 ;

//loop for checking the time of the server responding
while(!recd)
{
nBytes = socket.ReceiveFrom(ReceiveBuffer, 256, 0, ref EndPointFrom);
if (nBytes == SOCKET_ERROR)
{
Console.WriteLine("Host not Responding") ;
recd=true ;
break;
}
else if(nBytes>0)
{
dwStop = System.Environment.TickCount - dwStart; // stop timing
Console.WriteLine("Reply from "+epServer.ToString()+" in "+dwStop+"MS :Bytes Received"+nBytes);
recd=true;
break;
}
timeout=System.Environment.TickCount - dwStart;
if(timeout>1000)
{
Console.WriteLine("Time Out") ;
recd=true;
}

}

//close the socket
socket.Close();
}
///

/// This method get the Packet and calculates the total size
/// of the Pack by converting it to byte array
///

public static Int32 Serialize( IcmpPacket packet, Byte [] Buffer, Int32 PacketSize, Int32 PingData )
{
Int32 cbReturn = 0;
// serialize the struct into the array
int Index=0;

Byte [] b_type = new Byte[1];
b_type[0] = (packet.Type);

Byte [] b_code = new Byte[1];
b_code[0] = (packet.SubCode);

Byte [] b_cksum = BitConverter.GetBytes(packet.CheckSum);
Byte [] b_id = BitConverter.GetBytes(packet.Identifier);
Byte [] b_seq = BitConverter.GetBytes(packet.SequenceNumber);

// Console.WriteLine("Serialize type ");
Array.Copy( b_type, 0, Buffer, Index, b_type.Length );
Index += b_type.Length;

// Console.WriteLine("Serialize code ");
Array.Copy( b_code, 0, Buffer, Index, b_code.Length );
Index += b_code.Length;

// Console.WriteLine("Serialize cksum ");
Array.Copy( b_cksum, 0, Buffer, Index, b_cksum.Length );
Index += b_cksum.Length;

// Console.WriteLine("Serialize id ");
Array.Copy( b_id, 0, Buffer, Index, b_id.Length );
Index += b_id.Length;

Array.Copy( b_seq, 0, Buffer, Index, b_seq.Length );
Index += b_seq.Length;

// copy the data
Array.Copy( packet.Data, 0, Buffer, Index, PingData );
Index += PingData;
if( Index != PacketSize/* sizeof(IcmpPacket) */) {
cbReturn = -1;
return cbReturn;
}

cbReturn = Index;
return cbReturn;
}
///

/// This Method has the algorithm to make a checksum
///

public static UInt16 checksum( UInt16[] buffer, int size )
{
Int32 cksum = 0;
int counter;

counter = 0;

while ( size > 0 ) {

UInt16 val = buffer[counter];

cksum += Convert.ToInt32( buffer[counter] );
counter += 1;
size -= 1;
}

cksum = (cksum >> 16) + (cksum & 0xffff);
cksum += (cksum >> 16);
return (UInt16)(~cksum);
}
} // class ping
///

/// Class that holds the Pack information
///

public class IcmpPacket
{
public Byte Type; // type of message
public Byte SubCode; // type of sub code
public UInt16 CheckSum; // ones complement checksum of struct
public UInt16 Identifier; // identifier
public UInt16 SequenceNumber; // sequence number
public Byte [] Data;

} // class IcmpPacket
}

haha200014-Mar-05 15:39

4-Mar-05 15:39

the end i use two threads to ping more hosts.
one thread calls sendto function,the other calls receivefrom.
if i ping one host twice in one cycle,and the first time it costs 56ms,and the second time costs 1ms,why?

Dave Kreskowiak4-Mar-05 16:15

4-Mar-05 16:15

Look at what your timing! THe code as you wrote it, will time the DNS lookup of the host, the building of the ICMP Packet, opening the socket connection, sending the echo packet, ...

You're not timing the packet travel time, you're timing nearly your entire application from the time you hit enter to the time it takes for the first echo packet to come back. The only thing you weren't timing was how long it took to parse the command line parameters.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

haha200015-Mar-05 6:08

5-Mar-05 6:08

i have correct it,record the time just before sending the packet,
but the time costed is 56ms too

Dave Kreskowiak5-Mar-05 6:17

Authorisation Code Ideas?

5-Mar-05 6:17

Somehow, I doubt it. On top of that, unless you rewrite this code so you setup EVERYTHING you need to send and receive the packet, without doing anything in between the two, your still timing code to setup the receive.

The only thing that'll get the timing down to <10ms on loopback, is to rewrite the code so it's far more efficient. And from what I've seen, you've got a bunch of work to do.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Tom John4-Mar-05 3:18

Tom John

4-Mar-05 3:18

Hi
I am looking for a new way to licence our products. We currently ask the user to enter a company name, plus a load of parameters (such as package limits, number of users, expiry date, etc) which are then validated against an authorisation code we provide.

Each of our products have different parameters that relate to the functionality of that product, and as functionality increases, the number of parameters is also increasing.

Therefore, i am attempting to come up with a system that allows the user to enter just two bits of information, the Company Name and an Authorisation Code. The authorisation code is validated against the compan name and then the licence information is extracted out of the authorisation code.

It sounds great in principle, but i've no idea where to start on this, or if it is at all possible.

Any ideas or suggestions would be greatly appreciated.

Thanks

Tom

utf8 convert....

ABBASI_RA4-Mar-05 3:07

ABBASI_RA

4-Mar-05 3:07

hi i have a sqldb with unicode data column.(nvarchar)
i search the user data entry in textbox in webpage , in database.
please tell me how to convert string to utf8 charset?

thanks

Authentication/Sql Server and C#

C# Angel4-Mar-05 2:56

C# Angel

4-Mar-05 2:56

Hello All,

I am writing an application using c#. This is a client server application. I am trying to make a login box which would allow users to enter the windows user id and password. Then I would like to check that user id and password against what the user id and password of who is login onto the machine. After that I would then like to check that user id and password against the sql server database to see if they have permission to access the database. Please someone provide guidance. I have looked everywhere and no one seems to have an answer to this question! Thanks

Re: Authentication/Sql Server and C#

Colin Angus Mackay4-Mar-05 6:14

Colin Angus Mackay

4-Mar-05 6:14

This is not good policy - If your users already log into Windows at the start of the session then you should consider that they have already passed through an authentication mechanism. Asking then to log on again during as session will desensitise them to providing a user name and password whenever prompted so that eventually they will do it automatically without thinking (that's how phishing scams work - they prey on the psycology of the person just following a set of instructions blindly - so don't encourage them for goodnesssake!).

Cada uno es artifice de su ventura
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Re: Authentication/Sql Server and C#

Anonymous15-Mar-05 10:05

Anonymous

15-Mar-05 10:05

O.k. Thanks for your help

Still no solution :(

Radgar4-Mar-05 2:43

Radgar

4-Mar-05 2:43

Friends,
I've been searching for a solution to a problem for 2 days on Google and forums but couldn't succeed. The problem is how do I get the ListView selection highlight style as it is in VS .NET menus. There is an article "TreeListView" here http://www.codeproject.com/cs/miscctrl/treelistview.asp[^] that has this feature but it's a little complicated for me to distinguish this feature from rest of the code.

This is my 3rd post on the same subject and will be the last - so please forgive me.
Thanks.

Radgar
"Imagination is more important than knowledge." - Albert Einstein

Re: Still no solution :(

Dave Kreskowiak4-Mar-05 4:28

4-Mar-05 4:28

There is no such property. The control uses the system's Display Properties/Appearance colors to draw the highlights.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Re: Still no solution :(

Radgar4-Mar-05 8:37

Radgar

4-Mar-05 8:37

Dave, thanks for your time but I never said the control has the property. If it had, I'd never have asked this question, would I? The control can be inherited and/or custom-drawn via some Windows APIs or so.. I know it's possible and I gave a link of an example actually. But that example has too crowded code which is hard for me to pick the parts I need. Don't get me wrong but please read the post fully next time before answering because now my post seems like answered to other users who possibly has the correct solution I need.

Radgar
"Imagination is more important than knowledge." - Albert Einstein

Re: Still no solution :(

Dave Kreskowiak4-Mar-05 11:02

Re: I need some information

4-Mar-05 11:02

Radgar wrote:
Don't get me wrong but please read the post fully next time before answering because now my post seems like answered to other users who possibly has the correct solution I need.

I did. The solution IS to ownerdraw the entire control and use the colors you want, not the system. If the example that you found is too much to wrap your brain around all at once, pick it apart. Try certain things and see what they do. Because nearly all of what you saw in the example is what your going to have to go through to get the functionality you want. The question you show now be asking yourself is "Is this worth it?"

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

I need some information

iceburnbarry4-Mar-05 2:36

iceburnbarry

4-Mar-05 2:36

I need information about web pages that rent coders.
Thanks for your time Smile | :)

Dave Kreskowiak4-Mar-05 7:29