Question

I ‘m writing a C-Code in which i use sockets. I use this on windows and on linux, so i try to write it dynamicly. I wrote two functions to get a server/client-socket. There i have an error on compiling:

debian:~/cross_socket# make
gcc *.c -Wall
i586-mingw32msvc-gcc *.c -Wall -lws2_32
socket.c: In function 'get_client_socket':
socket.c:28: warning: passing argument 3 of 'get_socket' from incompatible pointer type
socket.c:13: note: expected 'int (*)(SOCKET,  const struct sockaddr *, int)' but argument is of type 'int (*)(SOCKET,  const struct sockaddr *, int)'
socket.c: In function 'get_server_socket_addr':
socket.c:43: warning: passing argument 3 of 'get_socket' from incompatible pointer type
socket.c:13: note: expected 'int (*)(SOCKET,  const struct sockaddr *, int)' but argument is of type 'int (*)(SOCKET,  const struct sockaddr *, int)'

gcc for my local system works great, but if i use mingw i get this error?!?
It says:
I use int (*)(SOCKET, const struct sockaddr *, int) instead of int (*)(SOCKET, const struct sockaddr *, int)… ?

Here the relevant code:

inline SOCKET get_socket(uint16_t port, in_addr_t socket_in_addr, int (*create)(SOCKET, 
const struct sockaddr*, socklen_t)) {
        SOCKADDR_IN addr;
        SOCKET result_socket = GET_SOCKET;
        if (SOCKET_NOK(result_socket))
                return SOCKET_INIT_ERROR;
        memset(&addr, 0, sizeof(SOCKADDR_IN));
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);
        addr.sin_addr.s_addr = socket_in_addr;
        if (CONNECT_NOK(create(result_socket, (SOCKADDR*)&addr, sizeof(SOCKADDR))))
                return SOCKET_INIT_ERROR;
        return result_socket;
}

SOCKET get_client_socket(char* target, uint16_t port) {
        return get_socket(port, inet_addr(target), &connect);
/*      SOCKADDR_IN addr;
        SOCKET client_socket = GET_SOCKET;
        if (SOCKET_NOK(client_socket))
                return SOCKET_INIT_ERROR;
        memset(&addr,0,sizeof(SOCKADDR_IN));
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);
        addr.sin_addr.s_addr = inet_addr(target);
        if (CONNECT_NOK(connect(client_socket, (SOCKADDR*)&addr, sizeof(SOCKADDR))))
                return SOCKET_INIT_ERROR;
        return client_socket;*/
}

SOCKET get_server_socket_addr(uint16_t port, in_addr_t socket_in_addr) {
        return get_socket(port, socket_in_addr, &bind);
/*      SOCKADDR_IN addr;
        SOCKET server_socket = GET_SOCKET;
        if (SOCKET_NOK(server_socket))
                return SOCKET_INIT_ERROR;
        memset(&addr, 0, sizeof(SOCKADDR_IN));
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);
        addr.sin_addr.s_addr = socket_in_addr;
        if (CONNECT_NOK(bind(server_socket, (SOCKADDR*)&addr, sizeof(SOCKADDR_IN))))
                return SOCKET_INIT_ERROR;
        return server_socket;*/
}

Has anyone an idea?

Answer 1

Probably calling wrong convention.

On Windows most of the API functions are defined as WINAPI, which is __stdcall, a.k.a. PASCAL. i.e. parameters are passed left-to-right, and the stack is cleaned by the callee.

OTOH default compilation calling convention is __cdecl.

P.S. It’d be nice if mingw printed a more detailed error information.