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error calling socket()

My code is as follows:

      /* Create the socket */
      s = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
      if(s == INVALID_SOCKET)
      {
            FILE *f = fopen("c:\\temp\\lsp.txt","a");
            fprintf(f,"socket() error: %d\n",WSAGetLastError());
            fclose(f);
            return 0;
      }

The error number returned by WSAGetLastError() is 183.  I looked in the winsock2.h header file, and I cant find any sort of reference to 183.  I'm hoping someone here can help me figure out this error.
0
lwinkenb
Asked:
lwinkenb
1 Solution
 
efnCommented:
First, you should capture the value from WSAGetLastError before calling fopen, because fopen can change the value.  Just save the value in a variable and use the variable after fopen to put out the value.

Second, do you have a call to WSAStartup before the code you showed?  It's necessary to initialize the library before you try to create a socket.

--efn
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jkrCommented:
Do you call 'WSAStartup()' before calling 'socket()'?

WORD wVersionRequested;
WSADATA wsaData;
int err;
 
wVersionRequested = MAKEWORD( 2, 2 );
 
err = WSAStartup( wVersionRequested, &wsaData );
if ( err != 0 ) {
    /* Tell the user that we could not find a usable */
    /* WinSock DLL.                                  */
    return;
}


Apart from that, try

     /* Create the socket */
    s = socket(AF_INET,SOCK_STREAM,0);
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lwinkenbAuthor Commented:
I was already calling WSAStartup(), so that isnt the problem.  I moved the WSAGetLastError() to a new line before the called to fopen(), and now it is giving me a legitamate error.  The error is WSAEPROVIDERFAILEDINIT.

I'm not sure exactly why I'm getting this error, but I think it's due to the fact that Im making the socket() call in DllMain() of a Layered Service Provider DLL.  
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jonathan6587Commented:
lwinkenb

Error 183 is:

"Cannot create a file when that file already exists."

Probably something to do with your "lsp.txt"

I suspect it is your use of fopen, specifically "a"

"a" opens the file for appending, but does not remove the end of file marker before writing new data -- thus if this is any type of loop or you've appended the file previously without closing the fclosing the file -- you would probably get an error like this.  I suggest you use "a+" -- it removes the end of file marker before new data is written and restores the marker after your done writing.


You can use the FormatMessage function to convert error number to the error message.

I'm not sure you care about this now, but it's good to know.

Also, you can type "net helpmsg 183" on the command line and it will convert the error number to a meaningful message.

Cheers,

Jonathan

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