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/* $OpenBSD: privsep_fdpass.c,v 1.8 2012/04/04 17:24:50 deraadt Exp $ */
/*
* Copyright (c) 2002 Matthieu Herrb
* Copyright (c) 2001 Niels Provos <provos@citi.umich.edu>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include "privsep.h"
void
send_fd(int sock, int fd)
{
struct msghdr msg;
union {
struct cmsghdr hdr;
char buf[CMSG_SPACE(sizeof(int))];
} cmsgbuf;
struct cmsghdr *cmsg;
struct iovec vec;
int result = 0;
ssize_t n;
memset(&msg, 0, sizeof(msg));
if (fd >= 0) {
msg.msg_control = (caddr_t)&cmsgbuf.buf;
msg.msg_controllen = sizeof(cmsgbuf.buf);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
*(int *)CMSG_DATA(cmsg) = fd;
} else
result = errno;
vec.iov_base = &result;
vec.iov_len = sizeof(int);
msg.msg_iov = &vec;
msg.msg_iovlen = 1;
if ((n = sendmsg(sock, &msg, 0)) == -1)
warn("%s: sendmsg(%d)", __func__, sock);
if (n != sizeof(int))
warnx("%s: sendmsg: expected sent 1 got %ld",
__func__, (long)n);
}
int
receive_fd(int sock)
{
struct msghdr msg;
union {
struct cmsghdr hdr;
char buf[CMSG_SPACE(sizeof(int))];
} cmsgbuf;
struct cmsghdr *cmsg;
struct iovec vec;
ssize_t n;
int result;
int fd;
memset(&msg, 0, sizeof(msg));
vec.iov_base = &result;
vec.iov_len = sizeof(int);
msg.msg_iov = &vec;
msg.msg_iovlen = 1;
msg.msg_control = &cmsgbuf.buf;
msg.msg_controllen = sizeof(cmsgbuf.buf);
if ((n = recvmsg(sock, &msg, 0)) == -1) {
warn("%s: recvmsg", __func__);
return -1;
}
if (n != sizeof(int))
warnx("%s: recvmsg: expected received 1 got %ld",
__func__, (long)n);
if (result == 0) {
cmsg = CMSG_FIRSTHDR(&msg);
if (cmsg == NULL) {
warnx("%s: no message header", __func__);
return (-1);
}
if (cmsg->cmsg_type != SCM_RIGHTS)
warnx("%s: expected type %d got %d", __func__,
SCM_RIGHTS, cmsg->cmsg_type);
fd = (*(int *)CMSG_DATA(cmsg));
return (fd);
} else {
errno = result;
return (-1);
}
}
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