sending a struct over UDP UNIX sockets in C

Question

I'm working on a client/server ftp program for a class using UNIX sockets in C. I have to send my data to this process my professor is having us use to simulate network traffic (called "troll"). It requires a special header. So I was going to try to make a struct with the header and then tack my data on to it... but my compiler keeps giving me this error...

"cannot convert to a pointer type" (referring to the last line of code)

I can not figure out what I am doing wrong...

/* make troll header */
    struct sockaddr_in dest, troll;
    struct {
        struct sockaddr_in header;
        char body[MAXDATASIZE];
    } message;
    message.header.sin_family = htons(AF_INET);
    message.header.sin_port = htons(SERVER_PORT);
    bcopy((char *)&server_name.sin_addr, (char *)&message.header.sin_addr, sizeof(server_name.sin_addr));

    troll.sin_family = AF_INET;
    troll.sin_port = htons(TROLL_PORT);
    bcopy((char *)&name.sin_addr, (char *)&troll.sin_addr, sizeof(name.sin_addr));

    /* send mini_buffer to troll */
    memcpy(message.body, mini_buffer, MAXDATASIZE);

    int result = sendto(troll_sock, (char *) &message, sizeof(message), 0, (struct sockaddr *) troll, sizeof(troll));

Answer 1

You need to pass the address of troll - not the the object itself. Try: ...(struct sockaddr *)(&troll)...