Re: Get interface MAC address in sys_accept4() syscall

[Guram Z. Savinov]

30.07.2010 03:42, Guram Z. Savinov ÐÐÑÐÑ:
> Hi all,
>
> in net/socket.c is syscall sys_accept4(). In it syscall I need to get 
> MAC address of interface, from connection is come.
> For example it is two interfaces eth0 and eth1. I want to know, from 
> what interface connection is come to sys_accept4().
> Please help me, how I can do it.
>
> Thank's for attention for my question.
I forget tell: kernel version: 2.6.28
Here is code of sys_accept4() syscall, in it I need get MAC address of 
interface:

/*
 *    For accept, we attempt to create a new socket, set up the link
 *    with the client, wake up the client, then return the new
 *    connected fd. We collect the address of the connector in kernel
 *    space and move it to user at the very end. This is unclean because
 *    we open the socket then return an error.
 *
 *    1003.1g adds the ability to recvmsg() to query connection pending
 *    status to recvmsg. We need to add that support in a way thats
 *    clean when we restucture accept also.
 */

asmlinkage long sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
                int __user *upeer_addrlen, int flags)
{
    struct socket *sock, *newsock;
    struct file *newfile;
    int err, len, newfd, fput_needed;
    struct sockaddr_storage address;

    if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
        return -EINVAL;

    if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
        flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;

    sock = sockfd_lookup_light(fd, &err, &fput_needed);
    if (!sock)
        goto out;

    err = -ENFILE;
    if (!(newsock = sock_alloc()))
        goto out_put;

    newsock->type = sock->type;
    newsock->ops = sock->ops;

    /*
     * We don't need try_module_get here, as the listening socket (sock)
     * has the protocol module (sock->ops->owner) held.
     */
    __module_get(newsock->ops->owner);

    newfd = sock_alloc_fd(&newfile, flags & O_CLOEXEC);
    if (unlikely(newfd < 0)) {
        err = newfd;
        sock_release(newsock);
        goto out_put;
    }

    err = sock_attach_fd(newsock, newfile, flags & O_NONBLOCK);
    if (err < 0)
        goto out_fd_simple;

    err = security_socket_accept(sock, newsock);
    if (err)
        goto out_fd;

    err = sock->ops->accept(sock, newsock, sock->file->f_flags);
    if (err < 0)
        goto out_fd;

    if (upeer_sockaddr) {
        if (newsock->ops->getname(newsock, (struct sockaddr *)&address,
&len, 2) < 0) {
            err = -ECONNABORTED;
            goto out_fd;
        }
        err = move_addr_to_user((struct sockaddr *)&address,
                    len, upeer_sockaddr, upeer_addrlen);
        if (err < 0)
            goto out_fd;
    }

    /* File flags are not inherited via accept() unlike another OSes. */

    fd_install(newfd, newfile);
    err = newfd;

    security_socket_post_accept(sock, newsock);

out_put:
    fput_light(sock->file, fput_needed);
out:
    return err;
out_fd_simple:
    sock_release(newsock);
    put_filp(newfile);
    put_unused_fd(newfd);
    goto out_put;
out_fd:
    fput(newfile);
    put_unused_fd(newfd);
    goto out_put;
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/