C / C++ / MFC

raw packet with setsockopt() and sendto()

31-May-03 17:18

The basic approach to this is to SetCapture() on the window you want to stay in. Then scroll it when the mouse moves outside its boundaries. Remember to ReleaseCapture() when you are finished

Kuniva30-May-03 11:32

Kuniva

30-May-03 11:32

Can someone please explain why my code isn't working???
I'm trying to send a raw UDP packet with a self constructed header.
I posted something like this earlier but i investigated the code since then and changed a bit cause it seemed to contain some bugs. BUT the problem remains the same, the code fails at runtime because the sendto() function returns 10049
WSAEADDRNOTAVAIL: Cannot assign requested address. This can also result from connect, sendto!!!, WSAConnect, WSAJoinLeaf, or WSASendTo when the remote address or port is not valid for a remote computer (for example, address or port 0).

Does this mean something might be wrong with my sin structure???? I don't understand, how can it be wrong, i mean, why would it even be USED as it is a raw packet and i constructed the header with the destination ip and port myself!!?? WTF | :WTF:

I really don't understand why it won't work, and its been bugging me for several days now so if anyone knows why it won't work, please let me know.

Here's the code:

<code>
#pragma comment( lib, "Ws2_32.lib" )

#define WIN32_LEAN_AND_MEAN

#include <winsock2.h>
#include <windows.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <conio.h>

#define IP               "172.27.2.15"
#define PORT          123
#define IP_DEST          "192.168.200.9"
#define PORT_DEST     123

#define SIO_RCVALL _WSAIOW(IOC_VENDOR,1)
#define MAX_ADDR_LEN 16
#define MAX_HOSTNAME_LAN 255


USHORT checksum(USHORT *buffer, int size);
void checkPacket(char * pacote);

struct tcpheader {
    unsigned short int th_sport;
    unsigned short int th_dport;
    unsigned int th_seq;
    unsigned int th_ack;
    unsigned char th_x2:4;
    unsigned char th_off:4;
    unsigned char th_flags;
    unsigned short int th_win;
    unsigned short int th_sum;
    unsigned short int th_urp;
}; /* total tcp header length: 20 bytes (=160 bits) */


struct ipheader {
    unsigned char ip_hl:4, ip_v:4; /* this means that each member is 4 bits */
    unsigned char ip_tos;
    unsigned short int ip_len;
    unsigned short int ip_id;
    unsigned short int ip_off;
    unsigned char ip_ttl;
    unsigned char ip_proto;
    unsigned short int ip_sum;
    unsigned int ip_src;
    unsigned int ip_dst;
}; /* total ip header length: 20 bytes (=160 bits) */


struct udpheader {
    unsigned short int uh_sport;
    unsigned short int uh_dport;
    unsigned short int uh_len;
    unsigned short int uh_sum;

}; /* 8 bytes */


int main (void)
{
    WSADATA wsd;
    char datagram[5000];
    unsigned int bOpt=1;


    if (WSAStartup(MAKEWORD(2,2), &wsd) != 0){
       printf("WSAStartup() failed: %d\n", GetLastError());
       return -1;
    }

    // Create a raw socket
    SOCKET s = WSASocket(AF_INET, SOCK_RAW, IPPROTO_UDP, NULL, 0,0);

    if (s == INVALID_SOCKET){
       printf("WSASocket() failed: %d\n", WSAGetLastError());
       return -1;
    }

    // ENABLE IPHDRINCL
    if (setsockopt(s, IPPROTO_IP, IP_HDRINCL, (char *)&bOpt, sizeof(bOpt)) == SOCKET_ERROR){
       printf("setsockopt(IP_HDRINCL) failed: %d\n", WSAGetLastError());
       return -1;
    }

    struct ipheader *iph = (struct ipheader *) datagram;
    struct udpheader *udph = (struct udpheader *) (datagram + 20);
    struct sockaddr_in sin; //, sockTeste;



    sin.sin_family = AF_INET;
    sin.sin_port = htons (PORT_DEST);
    sin.sin_addr.s_addr = inet_addr (IP_DEST);

    memset (datagram, 0, sizeof(datagram));     /* zero out the buffer */


    // IP Header
    
    iph->ip_hl           = 5;
    iph->ip_v          = 4;
    iph->ip_tos           = 0;
    iph->ip_len           = sizeof (struct ipheader) + sizeof (struct udpheader);
    iph->ip_id           = 1;
    iph->ip_off           = 0;
    iph->ip_ttl           = 100;
    iph->ip_proto      = 17;     // UDP
    iph->ip_sum           = 0;
    iph->ip_src           = inet_addr(IP);
    iph->ip_dst           = inet_addr(IP_DEST); //sin.sin_addr.s_addr;

    
    // UDP Header

    udph->uh_sport = htons (PORT);
    udph->uh_dport = htons (PORT_DEST);
    udph->uh_len   = sizeof (struct ipheader) + sizeof (struct udpheader);
    udph->uh_sum   = 0;
    
     
    // Put something in the packet
    strcpy(datagram+28,"Teste");
	datagram[5000] = NULL;


    // Calculate Checksum

    iph->ip_sum  = checksum((unsigned short *)&iph, sizeof(ipheader));
    //tcph->th_sum = checksum((unsigned short *)&tcph, sizeof(tcpheader));
    udph->uh_sum = checksum((unsigned short *)&udph, sizeof(udpheader));

    // check the packet made
    checkPacket(datagram);

    //while (1)
    //{
         //Send The Packet

         if (sendto(s, datagram, strlen(datagram), 0, (SOCKADDR *)&sin, sizeof(sin)) == SOCKET_ERROR)
         {
              printf("sendto() failed: %d\n", WSAGetLastError());
              return -1;
         }
         else{
              printf("OK\n");
         }
         //if (sendto(s, datagram, strlen(datagram), 0, (SOCKADDR *)&sin, sizeof(sin)) == SOCKET_ERROR)
         //{
         //     printf("sendto() failed: %d\n", WSAGetLastError());
         //     return -1;
         //}
         //else{
         //     printf("NOPE\n");
         //}
    //}
	getch();
    return 0;
}



// IP/TCP/UDP Checksum Function

USHORT checksum(USHORT *buffer, int size)
{

   unsigned long cksum=0;
   while (size > 1)
   {
       cksum += *buffer++;
       size  -= sizeof(USHORT);   
    }
   if (size)
   {
       cksum += *(UCHAR*)buffer;   
    }
   cksum = (cksum >> 16) + (cksum & 0xffff);
   cksum += (cksum >>16); 
    return (USHORT)(~cksum); 
}

void checkPacket(char * buff)
{
         
    ipheader* pIpheader;
    tcpheader* pTcpheader;
    udpheader* pUdpheader;
    
     SOCKADDR_IN saSource, saDest;
    int iNextheader;
    char * packetData;

    pIpheader = (ipheader *) buff;

    //IP Header
    printf("IP Header \n");
    printf("IHL: %d\n",(int)pIpheader->ip_hl);
    printf("VERSION: %d\n",pIpheader->ip_v);
    printf("TYPE OF SERVICE: %d\n",(int)pIpheader->ip_tos);
    printf("TOTAL LENGTH: %d\n",pIpheader->ip_len);
    printf("IDENTIFICATION: %d\n",pIpheader->ip_id);
    printf("FRAGMENT OFFSET: %d\n",pIpheader->ip_off);
    printf("TTL: %d\n",(int)pIpheader->ip_ttl);
    printf("PROTOCOL: %d\n", (int)pIpheader->ip_proto);
    printf("CHECKSUM: %d\n",pIpheader->ip_sum);

    saSource.sin_addr.s_addr = pIpheader->ip_src;
    printf("SOURCE ADDRESS: %s\n",inet_ntoa(saSource.sin_addr));
    
    saDest.sin_addr.s_addr = pIpheader->ip_dst;
    printf("DESTINATION ADDRESS: %s\n",inet_ntoa(saDest.sin_addr));

    iNextheader = (20);

    
     if ((int)pIpheader->ip_proto == 6)
    {
         //TCP Header

         pTcpheader = (tcpheader *) (buff + iNextheader);

         printf("\nTCP Header\n");

         saSource.sin_port = pTcpheader->th_sport;
         printf ("SOURCE PORT: %d\n", htons(saSource.sin_port));
         
         saDest.sin_port = pTcpheader->th_dport;
         printf ("DESTINATION PORT: %d\n", htons(saDest.sin_port));
         
         printf ("SEQUENCE: %d\n", pTcpheader->th_seq);
         printf ("ACK: %d\n", pTcpheader->th_ack);
         printf ("X2: %d\n", (int)pTcpheader->th_x2);
         printf ("OFF SET: %d\n", (int)pTcpheader->th_off);
         printf ("FLAGS: %d\n", (int)pTcpheader->th_flags);
         printf ("WINDOW: %d\n", pTcpheader->th_win);
         printf ("CHECKSUM: %d\n", pTcpheader->th_sum);
         printf ("URP: %d\n", pTcpheader->th_urp);

         // Data

         printf("\nDATA\n");

         iNextheader = (pIpheader->ip_hl * 4 + sizeof(tcpheader));

         packetData = (char *) (buff + iNextheader);
         printf ("DATA: %s\n", packetData);
    
     }
    if ((int)pIpheader->ip_proto == 17)
    {
         
         printf("\nUDP Header\n");
         
         pUdpheader = (udpheader *) (buff + iNextheader);

         saSource.sin_port = pUdpheader->uh_sport;
         printf ("SOURCE PORT: %d\n", htons(saSource.sin_port));
         
         saDest.sin_port = pUdpheader->uh_dport;
         printf ("DESTINATION PORT: %d\n", htons(saDest.sin_port));
         
         printf ("LEN: %d\n", pUdpheader->uh_len);
         printf ("CHECKSUM: %d\n", pUdpheader->uh_sum);
         
         // DATA
         
         printf("\nDATA\n");

         iNextheader = (pIpheader->ip_hl * 4 + sizeof(udpheader));

         packetData = (char *) (buff + iNextheader);
         printf ("DATA: %s\n", packetData);
    }
    

      getch();
}
</code>

Thanks

Kuniva
--------------------------------------------

JohnnyG30-May-03 18:34

JohnnyG

30-May-03 18:34

Kuniva wrote:
datagram[5000] = NULL;

I did only a cursory check so this is probably not your problem but was wondering what you were trying to do here. datagram is an array of 5000 but has elements 0 to 4999, so if you wanted to put a terminating '\0' you are overwriting the bounds of that array. Also, I don't think you can send a packet over ~1594 in size so I don't know why you would try to send 5000 bytes.

Probably a good idea to remove your strlen() call in the sendto(). BTW, you don't have to terminate your data with a trailing zero but I guess it could make it easier on the other side (recv side) if you knew you were handling strings. As you probably already know you would put the trailing zero after "Teste". Thus, the length in sendto() would be 5 or 6 (incl the terminating zero)

I don't know why you get the 10049 error. Perhaps, you are trying to access a reserved or dedicated port. If you are not, then I would choose a port number > 1023.

Kuniva31-May-03 5:11

Kuniva

31-May-03 5:11

erm..
Well first of all thanks for taking a look. I can understand most of the comments but there's two things i don't seem to understand:
1.: Why get rid of strlen() in sendto()? I can understand that i need to replace it with sizeof() but the argument in sendto() requests the size of datagram, which would be the header + the data
2.: So obviously the second thing i don't understand is this:
"Thus, the length in sendto() would be 5 or 6 (incl the terminating zero)"
Isn't my header in there too? and did i not use strcpy(datagram+28,"Teste") ??? to put the "Teste" string behind the ip+udp header? Or am i missing something here?
I realise you only took a quick look, and the code is somewhat chaotic, but this didn't seem to make sense to me.

I'll also try using a different port number.
Thanks

Kuniva
--------------------------------------------

JohnnyG31-May-03 13:20

JohnnyG

31-May-03 13:20

Well, I've never done raw before but in the past when I used sendto(), I always put the size of the data only. Search on this forum...within the last week or two somebody asked about how to do raw mode and somebody posted a link to a sample program on MSDN. This is where I downloaded this. Hope it helps:

#include <winsock2.h>
#include <windows.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <conio.h>

#pragma comment(lib, "ws2_32.lib")
#pragma pack(1)

struct tcpheader {
	unsigned short int th_sport;
	unsigned short int th_dport;
	unsigned int th_seq;
	unsigned int th_ack;
	unsigned char th_x2:4, th_off:4;
	unsigned char th_flags;
	unsigned short int th_win;
	unsigned short int th_sum;
	unsigned short int th_urp;
}; /* total tcp header length: 20 bytes (=160 bits) */

struct ipheader {
	unsigned char ip_hl:4, ip_v:4; /* this means that each member is 4 bits */
	unsigned char ip_tos;
	unsigned short int ip_len;
	unsigned short int ip_id;
	unsigned short int ip_off;
	unsigned char ip_ttl;
	unsigned char ip_p;
	unsigned short int ip_sum;
	unsigned int ip_src;
	unsigned int ip_dst;
}; /* total ip header length: 20 bytes (=160 bits) */

// IP/TCP/UDP Checksum Function

USHORT checksum(USHORT *buffer, int size)
{
	unsigned long cksum=0;
	while (size > 1)
	{
		cksum += *buffer++;
		size -= sizeof(USHORT); 
	}
	if (size)
	{
		cksum += *(UCHAR*)buffer; 
	}
	cksum = (cksum >> 16) + (cksum & 0xffff);
	cksum += (cksum >>16); 
	return (USHORT)(~cksum); 
}

#define PORT 25

int main (void)
{

	WSADATA wsd;
	char datagram[4096];
	int bOpt = 1;

	if (WSAStartup(MAKEWORD(2,2), &wsd) != 0)
	{
		printf("WSAStartup() failed: %d\n", GetLastError());
		return -1;
	}

	// Create a raw socket

	SOCKET s = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
	if (s == INVALID_SOCKET)
	{
		printf("WSASocket() failed: %d\n", WSAGetLastError());
		return -1;
	}

	struct ipheader *iph = (struct ipheader *) datagram;
	struct tcpheader *tcph = (struct tcpheader *) (datagram + sizeof (struct ipheader));
	struct sockaddr_in sin;

	sin.sin_family = AF_INET;
	sin.sin_port = htons (PORT);
	sin.sin_addr.s_addr = inet_addr ("2.3.4.5");

	memset (datagram, 0, 4096); /* zero out the buffer */

	iph->ip_hl = 5;
	iph->ip_v = 4;
	iph->ip_tos = 0;
	iph->ip_len = sizeof (struct ipheader) + sizeof (struct tcpheader);
	iph->ip_id = 1;
	iph->ip_off = 0;
	iph->ip_ttl = 255;
	iph->ip_p = 6;
	iph->ip_sum = 0;
	iph->ip_src = inet_addr ("1.2.3.4");
	iph->ip_dst = sin.sin_addr.s_addr;

	tcph->th_sport = htons (1234);
	tcph->th_dport = htons (PORT);
	tcph->th_seq = rand();
	tcph->th_ack = 0;
	tcph->th_x2 = 0;
	tcph->th_off = 5;
	tcph->th_flags = 2; // SYN
	tcph->th_win = htons(65535);
	tcph->th_sum = 0;
	tcph->th_urp = 0;

	iph->ip_sum = checksum((unsigned short *)&iph, sizeof(ipheader) >> 1);

	if (setsockopt(s, IPPROTO_IP, IP_HDRINCL, (char *)&bOpt, sizeof(bOpt)) == SOCKET_ERROR)
	{
		printf("setsockopt(IP_HDRINCL) failed: %d\n", WSAGetLastError());
		return -1;
	}

	printf("Started sending of raw data. Hit any key to quit\n");

	while (!kbhit())
	{
		// Send The Packet

		if (sendto(s, datagram, 40, 0, (SOCKADDR *)&sin, sizeof(sin)) == SOCKET_ERROR)
		{
			printf("sendto() failed: %d\n", WSAGetLastError());
			return -1;
		}
		printf(".");
		Sleep(1000);
		tcph->th_seq++;
	}

	return 0;
}

Peter Weyzen30-May-03 22:01

Peter Weyzen

30-May-03 22:01

along with Johnny's great comments, one thing struck me.

Since your tcp/ip/udp headers are "raw" network data -- they should be packed? Or am I wrong?

#pragma pack(push,1)<br />
struct<br />
{<br />
  BYTE x;<br />
  BYTE y;<br />
};<br />
#pragma pack(pop)

As I recall, structure members are aligned on DWORD boundaries by default. That is, that a struct like the one above would have 3 bytes of unused data between x and y. You can verify by doing a sizeof() on your data.

Packing it forces the structure members to line up one directly following the next (no space between items).

When in doubt, I always force things to pack for creating network packet headers....

Does this make sense? Does this apply? Am I incorrect?

-p

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br />
Peter Weyzen<br />
Staff Engineer<br />
Santa Cruz Networks

MySQL in a small app...

Gnascher30-May-03 10:25

Gnascher

30-May-03 10:25

I am planning to create a small application that will utilize a database for managing persistant data.

I'd like to use MySQL as the database engine, but am having a difficult time figuring out how I could distribute the app. without requiring the user to have MySQL installed.

Any help at all would be appreciated in helping me figure out what needs to be done to make this a reality.

Robert Little30-May-03 11:12

Robert Little

30-May-03 11:12

Don't tie your application to any database. Instead, have a requirement that the database be installed. Then have a little wizard or setup program that will request the userid and password for the database. Then use SQL statements to create the DB structure.

The only requirement is that your SQL statements work. I have created entire Access databases using SQL because all I had was the ODBC driver.

--

"The money power of the country will endeavor to prolong its rule by preying upon the prejudices of the people until all wealth is concentrated in a few hands and the Republic destroyed."
-- Abraham Lincoln

Anonymous30-May-03 12:00

30-May-03 12:00

Well, the problem with that solution is that a lot of people will be disinterested in the app based upon that alone. I don't want to have to pile on additional requirements beyond basic system requirements.

I want anybody (Your grandma, for instance) to be able to very simply dload and install this app and be up in running quickly and easily.

Robert Little30-May-03 18:21

Robert Little

30-May-03 18:21

Is an Access DB not up to the task? If it is you can setup an ODBC connection during setup and then use SQL to create an Access db.

You can have a setup that has an "Advanced" setup that will allow someone to use an existing db system instead and just use Access for grandma.

I can't remember where I read this or who said it, but it was something like this: "Make a system that any fool can use and only a fool will use it."

--

"The money power of the country will endeavor to prolong its rule by preying upon the prejudices of the people until all wealth is concentrated in a few hands and the Republic destroyed."
-- Abraham Lincoln

Neville Franks30-May-03 13:29

Neville Franks

30-May-03 13:29

MySQL seems like overkill for a "small application". Have a look at SQLite which is a small embedded SQL engine. http://www.hwaci.com/sw/sqlite/[^]

Neville Franks, Author of ED for Windows. Free Trial at www.getsoft.com

Gnascher30-May-03 14:20

Gnascher

30-May-03 14:20

Thanks ... this is the kind of thinking I was looking for!
Wink | ;)

I'll look into this, and see if it fits my needs. In the mean time ... more suggestions please!!

-G

How to get control(button) ID in runtime

Neville Franks31-May-03 0:21

Neville Franks

31-May-03 0:21

I keep an eye on small DB engines and I don't think you'll find too much else out there that is any good and well supported, but if you do let me know.

You haven't said what capabilities you are looking for, but an alternative I'd consider is XML.

Neville Franks, Author of ED for Windows. Free Trial at www.getsoft.com

Roman Muntyanu30-May-03 10:22

Roman Muntyanu

30-May-03 10:22

Hi all

I was trying to find a way how to get control ID (in my case button)
in run time using some Win API function but failed. I was looking for that ID that is hard coded usually in .h files.
The only similar API GetDlgCtrID() I found but it returns value different for each start of application. But I need an identifier for the button that is persisted and is the same along each start of the application. Similar how it works for the MenuItem IDs that are stored in the resource file.

Please let me know if it possible at all or application forgets this ID when it creates the window and identify it using just handler to the window.

Any advices greatly appreciated

Roman

Re: How to get control(button) ID in runtime

David Crow30-May-03 10:57

David Crow

30-May-03 10:57

GetDlgCtrlID() is what you want. Maybe it's being used incorrectly.

How to highlight an item in a list control in report view?

julych30-May-03 10:16

julych

30-May-03 10:16

How to highlight an item in a list control in report view?
I'm using SetSelectionMark(), but it doesn't work. What am I missing?

Re: How to highlight an item in a list control in report view?

skaanji30-May-03 10:49

skaanji

30-May-03 10:49

Try it with SetItemState()

Re: How to highlight an item in a list control in report view?

Michael Dunn30-May-03 11:32

Michael Dunn

30-May-03 11:32

See the FAQ
4.10 How do I programmatically select an item in a list view control?[^]

--Mike--
Latest blog entry: *drool* (Alyson) [May 10]
Ericahist | Homepage | RightClick-Encrypt | 1ClickPicGrabber
"You have Erica on the brain" - Jon Sagara to me

What is the Address of the Active IE ?

Anonymous30-May-03 9:18

Re: What is the Address of the Active IE ?

30-May-03 9:18

Hello

is it possible to come to the address (URL) of the active internet explorer window? if yes, how? if no, why not? and any other way as by programing? like java script or so...

thanks

David Crow30-May-03 9:57

David Crow

30-May-03 9:57

I haven't tried it, but my first guess would be IE Automation.

Re: What is the Address of the Active IE ?

Anonymous31-May-03 0:29