sendfd.c


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/* See LICENSE file for copyright and license details. */
#include "libsimple.h"


int
libsimple_sendfd(int sock, int fd)
{
	char buf[1];
	struct iovec iov;
	struct msghdr msg;
	struct cmsghdr *cmsg;
	char cms[CMSG_SPACE(sizeof(fd))];

	buf[0] = 0;
	iov.iov_base = buf;
	iov.iov_len = 1;

	memset(&msg, 0, sizeof(msg));
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;
	msg.msg_control = (caddr_t)cms;
	msg.msg_controllen = CMSG_LEN(sizeof(fd));

	cmsg = CMSG_FIRSTHDR(&msg);
	cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
	cmsg->cmsg_level = SOL_SOCKET;
	cmsg->cmsg_type = SCM_RIGHTS;
	memcpy(CMSG_DATA(cmsg), &fd, sizeof(fd));

	return -(sendmsg(sock, &msg, 0) != (ssize_t)iov.iov_len);
}