privsep_fdpass.c revision 145837 
166861Sadrian/*	$OpenBSD: privsep_fdpass.c,v 1.2 2004/08/13 02:51:48 djm Exp $	*/
223675Speter
31558Srgrimes/*
466861Sadrian * Copyright 2001 Niels Provos <provos@citi.umich.edu>
566861Sadrian * All rights reserved.
666861Sadrian *
766861Sadrian * Copyright (c) 2002 Matthieu Herrb
81558Srgrimes * All rights reserved.
966861Sadrian *
1033139Sjhay * Redistribution and use in source and binary forms, with or without
111558Srgrimes * modification, are permitted provided that the following conditions
121558Srgrimes * are met:
131558Srgrimes *
14 *    - Redistributions of source code must retain the above copyright
15 *      notice, this list of conditions and the following disclaimer.
16 *    - Redistributions in binary form must reproduce the above
17 *      copyright notice, this list of conditions and the following
18 *      disclaimer in the documentation and/or other materials provided
19 *      with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
29 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
31 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32 * POSSIBILITY OF SUCH DAMAGE.
33 */
34#include <sys/param.h>
35#include <sys/uio.h>
36#include <sys/types.h>
37#include <sys/socket.h>
38#include <sys/stat.h>
39#include <err.h>
40#include <errno.h>
41#include <fcntl.h>
42#include <signal.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <string.h>
46#include <unistd.h>
47#include "pflogd.h"
48
49void
50send_fd(int sock, int fd)
51{
52	struct msghdr msg;
53	char tmp[CMSG_SPACE(sizeof(int))];
54	struct cmsghdr *cmsg;
55	struct iovec vec;
56	int result = 0;
57	ssize_t n;
58
59	memset(&msg, 0, sizeof(msg));
60
61	if (fd >= 0) {
62		msg.msg_control = (caddr_t)tmp;
63		msg.msg_controllen = CMSG_LEN(sizeof(int));
64		cmsg = CMSG_FIRSTHDR(&msg);
65		cmsg->cmsg_len = CMSG_LEN(sizeof(int));
66		cmsg->cmsg_level = SOL_SOCKET;
67		cmsg->cmsg_type = SCM_RIGHTS;
68		*(int *)CMSG_DATA(cmsg) = fd;
69	} else {
70		result = errno;
71	}
72
73	vec.iov_base = &result;
74	vec.iov_len = sizeof(int);
75	msg.msg_iov = &vec;
76	msg.msg_iovlen = 1;
77
78	if ((n = sendmsg(sock, &msg, 0)) == -1)
79		warn("%s: sendmsg(%d)", __func__, sock);
80	if (n != sizeof(int))
81		warnx("%s: sendmsg: expected sent 1 got %ld",
82		    __func__, (long)n);
83}
84
85int
86receive_fd(int sock)
87{
88	struct msghdr msg;
89	char tmp[CMSG_SPACE(sizeof(int))];
90	struct cmsghdr *cmsg;
91	struct iovec vec;
92	ssize_t n;
93	int result;
94	int fd;
95
96	memset(&msg, 0, sizeof(msg));
97	vec.iov_base = &result;
98	vec.iov_len = sizeof(int);
99	msg.msg_iov = &vec;
100	msg.msg_iovlen = 1;
101	msg.msg_control = tmp;
102	msg.msg_controllen = sizeof(tmp);
103
104	if ((n = recvmsg(sock, &msg, 0)) == -1)
105		warn("%s: recvmsg", __func__);
106	if (n != sizeof(int))
107		warnx("%s: recvmsg: expected received 1 got %ld",
108		    __func__, (long)n);
109	if (result == 0) {
110		cmsg = CMSG_FIRSTHDR(&msg);
111		if (cmsg == NULL) {
112			warnx("%s: no message header", __func__);
113			return -1;
114		}
115		if (cmsg->cmsg_type != SCM_RIGHTS)
116			warnx("%s: expected type %d got %d", __func__,
117			    SCM_RIGHTS, cmsg->cmsg_type);
118		fd = (*(int *)CMSG_DATA(cmsg));
119		return fd;
120	} else {
121		errno = result;
122		return -1;
123	}
124}
125