socket_send_fd.c 1.57 KB
/**
 * \file
 *
 * \author	Georg Hopp
 *
 * \copyright
 * Copyright © 2014 Georg Hopp
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <errno.h>      // for errno
#include <unistd.h>
#include <fcntl.h>

#include "tr/socket.h"
#include "tr/logger.h"

void
TR_socketSendFd(TR_Socket this, int fd)
{
    struct msghdr    msg;
    struct cmsghdr * cmsg;
    char             cmsgbuf[CMSG_SPACE(sizeof(int))];

    memset(&msg, 0, sizeof(msg));
    msg.msg_control    = cmsgbuf;
    msg.msg_controllen = sizeof(cmsgbuf); // necessary for CMSG_FIRSTHDR to
                                          // return the correct value
    cmsg = CMSG_FIRSTHDR(&msg);
    cmsg->cmsg_level = SOL_SOCKET;
    cmsg->cmsg_type  = SCM_RIGHTS;
    cmsg->cmsg_len   = CMSG_LEN(sizeof(int));
    memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
    msg.msg_controllen = cmsg->cmsg_len; // total size of all control blocks

    sendmsg(TR_socketHandle(this), &msg, 0);
	/* TODO error handling... */
}

// vim: set ts=4 sw=4: