monitor_fdpass.c revision 180989 
1/* $OpenBSD: monitor_fdpass.c,v 1.12 2006/08/03 03:34:42 deraadt Exp $ */
2/*
3 * Copyright 2001 Niels Provos <provos@citi.umich.edu>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "includes.h"
28
29#include <sys/types.h>
30#include <sys/socket.h>
31#include <sys/uio.h>
32#ifdef HAVE_SYS_UN_H
33#include <sys/un.h>
34#endif
35
36#include <errno.h>
37#include <string.h>
38#include <stdarg.h>
39
40#include "log.h"
41#include "monitor_fdpass.h"
42
43void
44mm_send_fd(int sock, int fd)
45{
46#if defined(HAVE_SENDMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR))
47	struct msghdr msg;
48	struct iovec vec;
49	char ch = '\0';
50	ssize_t n;
51#ifndef HAVE_ACCRIGHTS_IN_MSGHDR
52	union {
53		struct cmsghdr hdr;
54		char buf[CMSG_SPACE(sizeof(int))];
55	} cmsgbuf;
56	struct cmsghdr *cmsg;
57#endif
58
59	memset(&msg, 0, sizeof(msg));
60#ifdef HAVE_ACCRIGHTS_IN_MSGHDR
61	msg.msg_accrights = (caddr_t)&fd;
62	msg.msg_accrightslen = sizeof(fd);
63#else
64	msg.msg_control = (caddr_t)&cmsgbuf.buf;
65	msg.msg_controllen = sizeof(cmsgbuf.buf);
66	cmsg = CMSG_FIRSTHDR(&msg);
67	cmsg->cmsg_len = CMSG_LEN(sizeof(int));
68	cmsg->cmsg_level = SOL_SOCKET;
69	cmsg->cmsg_type = SCM_RIGHTS;
70	*(int *)CMSG_DATA(cmsg) = fd;
71#endif
72
73	vec.iov_base = &ch;
74	vec.iov_len = 1;
75	msg.msg_iov = &vec;
76	msg.msg_iovlen = 1;
77
78	if ((n = sendmsg(sock, &msg, 0)) == -1)
79		fatal("%s: sendmsg(%d): %s", __func__, fd,
80		    strerror(errno));
81	if (n != 1)
82		fatal("%s: sendmsg: expected sent 1 got %ld",
83		    __func__, (long)n);
84#else
85	fatal("%s: UsePrivilegeSeparation=yes not supported",
86	    __func__);
87#endif
88}
89
90int
91mm_receive_fd(int sock)
92{
93#if defined(HAVE_RECVMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR))
94	struct msghdr msg;
95	struct iovec vec;
96	ssize_t n;
97	char ch;
98	int fd;
99#ifndef HAVE_ACCRIGHTS_IN_MSGHDR
100	union {
101		struct cmsghdr hdr;
102		char buf[CMSG_SPACE(sizeof(int))];
103	} cmsgbuf;
104	struct cmsghdr *cmsg;
105#endif
106
107	memset(&msg, 0, sizeof(msg));
108	vec.iov_base = &ch;
109	vec.iov_len = 1;
110	msg.msg_iov = &vec;
111	msg.msg_iovlen = 1;
112#ifdef HAVE_ACCRIGHTS_IN_MSGHDR
113	msg.msg_accrights = (caddr_t)&fd;
114	msg.msg_accrightslen = sizeof(fd);
115#else
116	msg.msg_control = &cmsgbuf.buf;
117	msg.msg_controllen = sizeof(cmsgbuf.buf);
118#endif
119
120	if ((n = recvmsg(sock, &msg, 0)) == -1)
121		fatal("%s: recvmsg: %s", __func__, strerror(errno));
122	if (n != 1)
123		fatal("%s: recvmsg: expected received 1 got %ld",
124		    __func__, (long)n);
125
126#ifdef HAVE_ACCRIGHTS_IN_MSGHDR
127	if (msg.msg_accrightslen != sizeof(fd))
128		fatal("%s: no fd", __func__);
129#else
130	cmsg = CMSG_FIRSTHDR(&msg);
131	if (cmsg == NULL)
132		fatal("%s: no message header", __func__);
133#ifndef BROKEN_CMSG_TYPE
134	if (cmsg->cmsg_type != SCM_RIGHTS)
135		fatal("%s: expected type %d got %d", __func__,
136		    SCM_RIGHTS, cmsg->cmsg_type);
137#endif
138	fd = (*(int *)CMSG_DATA(cmsg));
139#endif
140	return fd;
141#else
142	fatal("%s: UsePrivilegeSeparation=yes not supported",
143	    __func__);
144#endif
145}
146