monitor_fdpass.c revision 124208 
1/*
2 * Copyright 2001 Niels Provos <provos@citi.umich.edu>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "includes.h"
27RCSID("$OpenBSD: monitor_fdpass.c,v 1.4 2002/06/26 14:50:04 deraadt Exp $");
28
29#include <sys/uio.h>
30
31#include "log.h"
32#include "monitor_fdpass.h"
33
34void
35mm_send_fd(int socket, int fd)
36{
37#if defined(HAVE_SENDMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR))
38	struct msghdr msg;
39	struct iovec vec;
40	char ch = '\0';
41	ssize_t n;
42#ifndef HAVE_ACCRIGHTS_IN_MSGHDR
43	char tmp[CMSG_SPACE(sizeof(int))];
44	struct cmsghdr *cmsg;
45#endif
46
47	memset(&msg, 0, sizeof(msg));
48#ifdef HAVE_ACCRIGHTS_IN_MSGHDR
49	msg.msg_accrights = (caddr_t)&fd;
50	msg.msg_accrightslen = sizeof(fd);
51#else
52	msg.msg_control = (caddr_t)tmp;
53	msg.msg_controllen = CMSG_LEN(sizeof(int));
54	cmsg = CMSG_FIRSTHDR(&msg);
55	cmsg->cmsg_len = CMSG_LEN(sizeof(int));
56	cmsg->cmsg_level = SOL_SOCKET;
57	cmsg->cmsg_type = SCM_RIGHTS;
58	*(int *)CMSG_DATA(cmsg) = fd;
59#endif
60
61	vec.iov_base = &ch;
62	vec.iov_len = 1;
63	msg.msg_iov = &vec;
64	msg.msg_iovlen = 1;
65
66	if ((n = sendmsg(socket, &msg, 0)) == -1)
67		fatal("%s: sendmsg(%d): %s", __func__, fd,
68		    strerror(errno));
69	if (n != 1)
70		fatal("%s: sendmsg: expected sent 1 got %ld",
71		    __func__, (long)n);
72#else
73	fatal("%s: UsePrivilegeSeparation=yes not supported",
74	    __func__);
75#endif
76}
77
78int
79mm_receive_fd(int socket)
80{
81#if defined(HAVE_RECVMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR))
82	struct msghdr msg;
83	struct iovec vec;
84	ssize_t n;
85	char ch;
86	int fd;
87#ifndef HAVE_ACCRIGHTS_IN_MSGHDR
88	char tmp[CMSG_SPACE(sizeof(int))];
89	struct cmsghdr *cmsg;
90#endif
91
92	memset(&msg, 0, sizeof(msg));
93	vec.iov_base = &ch;
94	vec.iov_len = 1;
95	msg.msg_iov = &vec;
96	msg.msg_iovlen = 1;
97#ifdef HAVE_ACCRIGHTS_IN_MSGHDR
98	msg.msg_accrights = (caddr_t)&fd;
99	msg.msg_accrightslen = sizeof(fd);
100#else
101	msg.msg_control = tmp;
102	msg.msg_controllen = sizeof(tmp);
103#endif
104
105	if ((n = recvmsg(socket, &msg, 0)) == -1)
106		fatal("%s: recvmsg: %s", __func__, strerror(errno));
107	if (n != 1)
108		fatal("%s: recvmsg: expected received 1 got %ld",
109		    __func__, (long)n);
110
111#ifdef HAVE_ACCRIGHTS_IN_MSGHDR
112	if (msg.msg_accrightslen != sizeof(fd))
113		fatal("%s: no fd", __func__);
114#else
115	cmsg = CMSG_FIRSTHDR(&msg);
116#ifndef BROKEN_CMSG_TYPE
117	if (cmsg->cmsg_type != SCM_RIGHTS)
118		fatal("%s: expected type %d got %d", __func__,
119		    SCM_RIGHTS, cmsg->cmsg_type);
120#endif
121	fd = (*(int *)CMSG_DATA(cmsg));
122#endif
123	return fd;
124#else
125	fatal("%s: UsePrivilegeSeparation=yes not supported",
126	    __func__);
127#endif
128}
129