xref: /freebsd/crypto/openssh/monitor_fdpass.c (revision 3047fefe49f57a673de8df152c199de12ec2c6d3)
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"
27 RCSID("$OpenBSD: monitor_fdpass.c,v 1.3 2002/06/04 23:05:49 markus Exp $");
28 
29 #include <sys/uio.h>
30 
31 #include "log.h"
32 #include "monitor_fdpass.h"
33 
34 void
35 mm_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 	int 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 %d",
71 		    __func__, n);
72 #else
73 	fatal("%s: UsePrivilegeSeparation=yes not supported",
74 	    __func__);
75 #endif
76 }
77 
78 int
79 mm_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 	char ch;
85 	int fd, n;
86 #ifndef HAVE_ACCRIGHTS_IN_MSGHDR
87 	char tmp[CMSG_SPACE(sizeof(int))];
88 	struct cmsghdr *cmsg;
89 #endif
90 
91 	memset(&msg, 0, sizeof(msg));
92 	vec.iov_base = &ch;
93 	vec.iov_len = 1;
94 	msg.msg_iov = &vec;
95 	msg.msg_iovlen = 1;
96 #ifdef HAVE_ACCRIGHTS_IN_MSGHDR
97 	msg.msg_accrights = (caddr_t)&fd;
98 	msg.msg_accrightslen = sizeof(fd);
99 #else
100 	msg.msg_control = tmp;
101 	msg.msg_controllen = sizeof(tmp);
102 #endif
103 
104 	if ((n = recvmsg(socket, &msg, 0)) == -1)
105 		fatal("%s: recvmsg: %s", __func__, strerror(errno));
106 	if (n != 1)
107 		fatal("%s: recvmsg: expected received 1 got %d",
108 		    __func__, n);
109 
110 #ifdef HAVE_ACCRIGHTS_IN_MSGHDR
111 	if (msg.msg_accrightslen != sizeof(fd))
112 		fatal("%s: no fd", __func__);
113 #else
114 	cmsg = CMSG_FIRSTHDR(&msg);
115 	if (cmsg->cmsg_type != SCM_RIGHTS)
116 		fatal("%s: expected type %d got %d", __func__,
117 		    SCM_RIGHTS, cmsg->cmsg_type);
118 	fd = (*(int *)CMSG_DATA(cmsg));
119 #endif
120 	return fd;
121 #else
122 	fatal("%s: UsePrivilegeSeparation=yes not supported",
123 	    __func__);
124 #endif
125 }
126