1/*	$NetBSD: privsep_fdpass.c,v 1.2 2005/07/01 12:43:50 peter Exp $	*/
2/*	$OpenBSD: privsep_fdpass.c,v 1.2 2004/08/13 02:51:48 djm Exp $	*/
3
4/*
5 * Copyright 2001 Niels Provos <provos@citi.umich.edu>
6 * All rights reserved.
7 *
8 * Copyright (c) 2002 Matthieu Herrb
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 *
15 *    - Redistributions of source code must retain the above copyright
16 *      notice, this list of conditions and the following disclaimer.
17 *    - Redistributions in binary form must reproduce the above
18 *      copyright notice, this list of conditions and the following
19 *      disclaimer in the documentation and/or other materials provided
20 *      with the distribution.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
30 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
32 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33 * POSSIBILITY OF SUCH DAMAGE.
34 */
35#include <sys/param.h>
36#include <sys/uio.h>
37#include <sys/types.h>
38#include <sys/socket.h>
39#include <sys/stat.h>
40#include <err.h>
41#include <errno.h>
42#include <fcntl.h>
43#include <signal.h>
44#include <stdio.h>
45#include <stdlib.h>
46#include <string.h>
47#include <unistd.h>
48#include "pflogd.h"
49
50void
51send_fd(int sock, int fd)
52{
53	struct msghdr msg;
54	char tmp[CMSG_SPACE(sizeof(int))];
55	struct cmsghdr *cmsg;
56	struct iovec vec;
57	int result = 0;
58	ssize_t n;
59
60	memset(&msg, 0, sizeof(msg));
61
62	if (fd >= 0) {
63		msg.msg_control = (caddr_t)tmp;
64		msg.msg_controllen = CMSG_LEN(sizeof(int));
65		cmsg = CMSG_FIRSTHDR(&msg);
66		cmsg->cmsg_len = CMSG_LEN(sizeof(int));
67		cmsg->cmsg_level = SOL_SOCKET;
68		cmsg->cmsg_type = SCM_RIGHTS;
69		*(int *)CMSG_DATA(cmsg) = fd;
70	} else {
71		result = errno;
72	}
73
74	vec.iov_base = &result;
75	vec.iov_len = sizeof(int);
76	msg.msg_iov = &vec;
77	msg.msg_iovlen = 1;
78
79	if ((n = sendmsg(sock, &msg, 0)) == -1)
80		warn("%s: sendmsg(%d)", __func__, sock);
81	if (n != sizeof(int))
82		warnx("%s: sendmsg: expected sent 1 got %ld",
83		    __func__, (long)n);
84}
85
86int
87receive_fd(int sock)
88{
89	struct msghdr msg;
90	char tmp[CMSG_SPACE(sizeof(int))];
91	struct cmsghdr *cmsg;
92	struct iovec vec;
93	ssize_t n;
94	int result;
95	int fd;
96
97	memset(&msg, 0, sizeof(msg));
98	vec.iov_base = &result;
99	vec.iov_len = sizeof(int);
100	msg.msg_iov = &vec;
101	msg.msg_iovlen = 1;
102	msg.msg_control = tmp;
103	msg.msg_controllen = sizeof(tmp);
104
105	if ((n = recvmsg(sock, &msg, 0)) == -1)
106		warn("%s: recvmsg", __func__);
107	if (n != sizeof(int))
108		warnx("%s: recvmsg: expected received 1 got %ld",
109		    __func__, (long)n);
110	if (result == 0) {
111		cmsg = CMSG_FIRSTHDR(&msg);
112		if (cmsg == NULL) {
113			warnx("%s: no message header", __func__);
114			return -1;
115		}
116		if (cmsg->cmsg_type != SCM_RIGHTS)
117			warnx("%s: expected type %d got %d", __func__,
118			    SCM_RIGHTS, cmsg->cmsg_type);
119		fd = (*(int *)CMSG_DATA(cmsg));
120		return fd;
121	} else {
122		errno = result;
123		return -1;
124	}
125}
126