Thread: C Socket programming problem

Hi Guys and Girls... I should imagine it is actually mainly guys here, but best not to be sexist!

I have written this code

Code:

#include <stdio.h>          /* stderr, stdout */
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/ip.h> /* superset of previous */
#include <string.h>

int net_listen() {
    int fn_socket, fn_bind_result;
    fn_socket = socket(AF_INET, SOCK_STREAM, 0);
    if (fn_socket < 0) return -1;
    printf ("net_listen: socket created.\n");
    struct sockaddr_in fn_bind_addr;
    memset(&fn_bind_addr, 0, sizeof(struct sockaddr_in));
    fn_bind_addr.sin_family = AF_INET;
    fn_bind_addr.sin_port = htons(4080);
    fn_bind_addr.sin_addr.s_addr = INADDR_ANY;
    fn_bind_result = bind(fn_socket, &fn_bind_addr, sizeof(struct sockaddr_in));
    if (fn_bind_result < 0) return -1;
    printf ("net_listen: bind success");
}

Codeblocks says this when I try to compile it:

/home/jamie/aws/socket_linux.cpp|18|error: cannot convert ‘sockaddr_in*’ to ‘const sockaddr*’ for argument ‘2’ to ‘int bind(int, const sockaddr*, socklen_t)’|

Anyone able to tell me the problem?

Jamie

From experience...

SOCKADDR_IN is a fine way to alias a SOCKADDR struct to get at the bits inside... but it's not a struct you want to be passing around to various functions. Almost none of the socket procedures can use it directly.

You could try...

Code:

   fn_bind_result = bind(fn_socket, (sockaddr*)&fn_bind_addr, sizeof(struct sockaddr_in));

But I ain't makin' no promises.

my two cents:

1. from your commandline i suspect you code onto linux, i am not that familiar with linux in include files, on bsd for this to work you will need at least(coding in c not c++)

Code:

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

2. for your socket problem commentater almost had it, if you look into the definition of bind you see it is asking for the struct so give it what it needs:

Code:

fn_bind_result = bind(fn_socket, (struct sockaddr *)&fn_bind_addr, sizeof(fn_bind_addr));

i changed the sizeof as well to the sizeof fn_bind_addr.

have fun,
fc

I'm working from windows ... yet another OS in the mix.

In windows sockaddr is a typedef so no need for (struct sockaddr*), in fact I could use (PSOCKADDR) in the cast.

Changing the size of is a good idea...

Originally Posted by CommonTater

I'm working from windows ... yet another OS in the mix.

right, there were some other OS in the wild