Winsock error 10049

Dear programmers,

i'm trying to make a internet connection in a C program using Winsock. I found a great tut (Programming Windows TCP Sockets in C++ for the Beginner - CodeProject) but everything did not work as aspected. I have a winsock error n.o. 10049. When I search for this i see this : "The requested address is not valid in its context."
(source:

when I try to set up a loopback connection it gives no errors, but doesn't work either: he always think that there is a connectioncall (other words: the program doesn't "hang"). What am I doing wrong?

here is the server code:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <winsock.h>
int ListenOnPort(int portno);
int main()
{
    int errorcode=0;
    printf("Hello world!\n");
   // while(1)
        errorcode=ListenOnPort(6221);
    printf("errorcode is %d", errorcode);
    return 0;
}

//LISTENONPORT – Listens on a specified port for incoming connections
//or data
int ListenOnPort(int portno)
{
    SOCKET s;
    WSADATA w;
    int error = WSAStartup (0x0202, &w);   // Fill in WSA info

    if (error)
    {
        return 50; //For some reason we couldn't start Winsock
    }

    if (w.wVersion != 0x0202) //Wrong Winsock version?
    {
        WSACleanup ();
        return 51;
    }

    SOCKADDR_IN addr; // The address structure for a TCP socket

    addr.sin_family = AF_INET;      // Address family
    addr.sin_port = htons (portno);   // Assign port to this socket

    //Accept a connection from any IP using INADDR_ANY
    //You could pass inet_addr("0.0.0.0") instead to accomplish the
    //same thing. If you want only to watch for a connection from a
    //specific IP, specify that //instead.
    addr.sin_addr.s_addr = inet_addr("127.0.0.1");

    s = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP); // Create socket

    if (s == INVALID_SOCKET)
        {
        return 52; //Don't continue if we couldn't create a //socket!!
        }
    if (bind(s, (LPSOCKADDR)&addr, sizeof(addr)) == SOCKET_ERROR)
        {
        wprintf(L"bind failed with error %u\n", WSAGetLastError());
        closesocket(s);
        WSACleanup();
       //We couldn't bind (this will happen if you try to bind to the same
       //socket more than once)
        return 53;
        }

    //Now we can start listening (allowing as many connections as possible to
    //be made at the same time using SOMAXCONN). You could specify any
    //integer value equal to or lesser than SOMAXCONN instead for custom
    //purposes). The function will not //return until a connection request is
    //made
    listen(s, SOMAXCONN);
    printf("Done\n");

    //Don't forget to clean up with CloseConnection()!
}

kind regards,

Libpgeak

EDIT: when I change the IPaddres to 192.168.0.28 I get this error.

Have you checked your firewall settings and logs to see if it is being blocked?

There are no firewall errors / blocks. The weird thing is 127.0.0.1 gives a direct "done" message, but there is no client running...

"...(line 65) The function (listen) will not return until a connection request is made..."

Are you sure? 'listen' function starts your socket listening for incoming socket connections until the maximum you specifyed (SOMAXCONN), and returns immediatelly an integer as error code (0 on success and SOCKET_ERROR on failure). So there's nothing strange on your code if you call listen and it printfs immediatelly the 'Done' statement, simply add an 'accept' to block your program until a connection request is made (check the winsock reference for more information about 'accept').

The error code 10049 could be meaning that you don't have the 192.168.0.28 local IP address; have you checked your local IP? If you have setup your network connection to be automathic you can have different IP each time you start your pc.

Hope that helps
Niara

Thanks Niara, the accept was the trick =]